JP2015011070A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner capable of providing a stable image density regardless of use environment and inhibiting occurrences of void and contamination of a charged roller even under conditions of down-sizing an image forming apparatus and elongating the service life.SOLUTION: The toner includes toner particles each containing a binding resin and a colorant, and small-particle-size and large-particle-size inorganic microparticles that are present on a toner particle surface. The small-particle-size and large-particle-size inorganic microparticles are small-particle-size and large-particle-size silica microparticles having a number average particle diameter of a specific primary particle, and the toner includes the small-particle-size and large-particle-size silica microparticles at specific ratios and amounts. A total coverage X1 of the toner surface by the small-particle-size and large-particle-size silica microparticles obtained by an X-ray photoelectron spectrometer is equal to or larger than 40.0 area% and equal to or smaller than 75.0 area%, and when a total theoretical coverage by small-particle-size and large-particle-size silica microparticles is defined as X2, a diffusion exponent represented by [diffusion exponent=X1/X2] satisfies [diffusion exponent≥-0.0042×X1+0.62].

Description

  The present invention relates to a toner used in a recording method using electrophotography or the like.

In copiers and printers, the lifespan of the devices has been extended along with the miniaturization of the devices. In view of these points, an advantageous one-component development system is preferably used.
From the viewpoint of reducing the size of the apparatus, it is important to reduce the size of each member such as a toner carrier (hereinafter referred to as a developing sleeve) and a charging roller. In the one-component development system, toner is conveyed to a development area using a development sleeve and developed. In addition, charge application to the toner is performed mainly by frictional charging by rubbing between the toner and a frictional charge applying member such as a developing sleeve in a region where the toner is regulated by a toner regulating member (hereinafter referred to as a developing blade). Further, in the one-component development method, the charging roller performs charge application by contacting the electrostatic latent image carrier.
From the viewpoint of extending the life of the apparatus, it is important to increase the toner filling amount and to reduce the toner consumption per printed sheet. There is a need for a technique that can obtain sufficient image quality even with deteriorated toner.
It has been found that combining this extension of the device life with the miniaturization of each member creates various technical challenges.

When combining a device with a longer life and a developing sleeve with a smaller diameter than the conventional one, after performing a durability use test in a high temperature and high humidity environment and outputting a solid white image continuously in the second half of the durability use test, a solid black image is output. There arises a problem that a solid black image is missing in white (hereinafter, white missing).
This white spot is caused by the fact that when the toner deteriorates, the entire toner on the developing sleeve is not properly frictionally charged, and the charge amount becomes excessive (hereinafter, charged up). Specifically, in order for the entire toner to be properly frictionally charged, the toner circulating in the blade nip needs to be replaced with the toner in contact with the developing sleeve or the developing blade in the blade nip. It becomes. However, deteriorated toner has poor circulatory properties, and the entire toner tends to be difficult to be properly frictionally charged.Part of the toner is charged up and sticks to the developing sleeve. End up. In particular, when the diameter of the developing sleeve is reduced, the area in which the developing sleeve and the developing blade are rubbed (hereinafter referred to as the blade nip) becomes narrow, so that the toner circulation is poor and the entire toner is sufficiently slid. I can't get rubbing. For this reason, the toner is easily charged up, and white spots are likely to occur.
In general, toner used for electrophotography or the like is externally added with inorganic fine particles or the like for the purpose of obtaining good developability, cleaning properties and transferability by adjusting the chargeability and fluidity of the toner. Among them, small-sized inorganic fine particles are often used as the inorganic fine particles in order to obtain good fluidity and chargeability.
The toner externally added with such inorganic particles having a small particle diameter is stressed by the collision between the developing blade, the developing sleeve, the inner wall of the developing device, the toner stirring member, and the toner. At this time, small particles of inorganic fine particles are embedded on the surface of the toner particles, and sufficient fluidity of the toner cannot be secured. Therefore, in the second half of the endurance use, the toner deteriorates in fluidity due to the embedding of the small particle size inorganic fine particles, the toner on the developing sleeve is charged up, and white spots are likely to occur.

Conventionally, in order to suppress the embedding of the small particle size inorganic fine particles, it is considered effective to use the large particle size inorganic fine particles in combination as disclosed in Patent Documents 1 to 3.
Since the large particle size inorganic fine particles have an effect as a spacer, the toner surface to which the small particle size inorganic fine particles are attached is prevented from coming into direct contact with the developing blade, the developing sleeve, the inner wall of the developing device, the toner stirring member, and other toners. Reduce stress. As a result, it is possible to prevent the small particle size inorganic fine particles from being buried in the surface of the toner particles, and to extend the life of the toner.
In Patent Document 1, suppression of a decrease in image density is achieved by using large-diameter inorganic particles and hydrophobized inorganic fine particles.
In Patent Document 2, spherical defects of 50 nm or more and 300 nm or less are added, and image defects are reduced by controlling the release rate of the spherical particles.

On the other hand, from the viewpoint of downsizing the member, it is effective to use a charging roller having a smaller diameter than the conventional one. However, in a configuration in which a small-diameter charging roller and an apparatus having a long life are combined, charging roller contamination becomes significant. This is because the accumulation of the external additive increases due to the longer life, and the surface area of the charging roller decreases due to the reduction in the diameter of the charging roller, so that the accumulated amount of the external additive per unit area of the charging roller increases. .
As described above, as the apparatus is further reduced in size and extended in service life, it becomes more and more important that both white spots and contamination of the charging roller become more strict.

Japanese Patent Laid-Open No. 11-143118 JP 2009-186812 A

  An object of the present invention is to provide a toner that solves the above problems. Specifically, regardless of the environment of use, stable images can be obtained, and even under conditions where the image forming apparatus is downsized and extended in life, the occurrence of white spots is suppressed, and the amount of inorganic fine particles added is suppressed to reduce contamination of the charging roller. It is an object of the present invention to provide a toner capable of suppressing the above.

The present inventors have found that the above-mentioned problems can be solved by defining the external addition state of inorganic fine particles to the toner, and defining the amount and proportion of the large particle size inorganic particles and small particle size inorganic particles, The present invention has been completed. That is, the present invention is as follows.
A toner particle containing a binder resin and a colorant, and a toner having small particle size inorganic particles and large particle size inorganic particles present on the surface of the toner particles,
The small particle size inorganic fine particles are small particle size silica fine particles having a number average particle size (D1) of primary particles of 5 nm or more and 20 nm or less,
The large particle size inorganic fine particles are large particle size silica fine particles having a number average particle size (D1) of primary particles of 25 nm or more and 100 nm or less,
The content of the small particle size silica fine particles per 100 parts by mass of the toner particles is M parts by mass,
When the content of the large particle size silica fine particles per 100 parts by mass of toner particles is N parts by mass,
M and N satisfy the following formula 1 and formula 2,
(Formula 1) 0.6 ≦ M + N ≦ 1.5
(Formula 2) 0.2 ≦ N / M ≦ 1.3
The total coverage X1 by the small particle size silica particles and the large particle size silica particles on the toner surface determined by an X-ray photoelectron spectrometer (ESCA) is 40.0 area% or more and 75.0 area% or less. A toner characterized in that a diffusion index represented by the following formula 3 satisfies the following formula 4 when the total theoretical coverage by the small particle size silica fine particles and the large particle size silica fine particles is X2.

(Formula 3) Diffusion index = X1 / X2
(Expression 4) Diffusion index ≧ −0.0042 × X1 + 0.62

  According to the present invention, a stable image can be obtained regardless of the use environment, and the occurrence of white spots can be suppressed even in a strict structure against toner deterioration such as downsizing and long life of the image forming apparatus, and contamination of the charging roller can be prevented. Can be suppressed.

Diagram showing the boundary of the diffusion index Schematic diagram showing an example of a mixing treatment apparatus that can be used for external addition mixing of inorganic fine particles The schematic diagram which shows an example of a structure of the stirring member used for a mixing processing apparatus The figure which shows an example of an image forming apparatus A graph plotting the total coverage X1 and diffusion index of toner used in Examples and Comparative Examples

The present invention is as follows.
A toner particle containing a binder resin and a colorant, and a toner having small particle size inorganic particles and large particle size inorganic particles present on the surface of the toner particles,
The small particle size inorganic fine particles are small particle size silica fine particles having a number average particle size (D1) of primary particles of 5 nm or more and 20 nm or less,
The large particle size inorganic fine particles are large particle size silica fine particles having a number average particle size (D1) of primary particles of 25 nm or more and 100 nm or less,
The content of the small particle size silica fine particles per 100 parts by mass of the toner particles is M parts by mass,
When the content of the large particle size silica fine particles per 100 parts by mass of toner particles is N parts by mass,
M and N satisfy the following formula 1 and formula 2,
(Formula 1) 0.6 ≦ M + N ≦ 1.5
(Formula 2) 0.2 ≦ N / M ≦ 1.3
The total coverage X1 by the small particle size silica particles and the large particle size silica particles on the toner surface determined by an X-ray photoelectron spectrometer (ESCA) is 40.0 area% or more and 75.0 area% or less. A toner characterized in that a diffusion index represented by the following formula 3 satisfies the following formula 4 when the total theoretical coverage by the small particle size silica fine particles and the large particle size silica fine particles is X2. (Formula 3) Diffusion index = X1 / X2
(Expression 4) Diffusion index ≧ −0.0042 × X1 + 0.62

According to the study by the present inventors, by using the toner as described above, a stable image density can be obtained regardless of the use environment, and the occurrence of white spots is suppressed even in a high temperature and high humidity environment, and at the same time, the charging roller It becomes possible to suppress contamination.
Here, white spots in an image in a high temperature and high humidity environment are considered to occur due to the following causes.
As the durability use test proceeds in a high temperature and high humidity environment, the toner is subjected to stress by rubbing at the blade nip and other members. Then, the small particle size inorganic fine particles are embedded in the surface of the toner particles, the toner deteriorates, and sufficient fluidity cannot be secured. For this reason, the toner circulation property in the blade nip is deteriorated such that the toner in contact with the developing sleeve or the developing blade in the blade nip is replaced with the toner not in contact. Deterioration of toner circulation causes an increase in the amount of toner that is rubbed many times at the blade nip, causing charge-up, and the toner sticks to the developing sleeve and is not developed, resulting in white spots.
In particular, when the life of the apparatus is to be extended, the toner is exposed to stress for a long time, so that the silica particles having a small particle diameter are easily embedded and white spots are likely to occur.
On the other hand, when the diameter of the developing sleeve is reduced in order to reduce the size, the blade nip is narrowed, resulting in poor toner circulation, and the entire toner is not properly charged and the toner is likely to be charged up. Here, when the toner is deteriorated, proper chargeability cannot be obtained unless the toner has sufficient fluidity.

As described above, in the configuration in which the diameter of the developing sleeve is reduced and the life of the apparatus is extended, the embedding of the fine particle silica particles in the toner (deterioration of the toner) becomes more severe, and the circulation of the toner becomes worse. Will be charged up and white spots will occur.
In general, by adding large-sized inorganic fine particles, embedding of small-sized inorganic fine particles is suppressed to some extent due to the spacer effect, but under the severe evaluation conditions as described above, the occurrence of white spots is suppressed. The effect is not enough.
On the other hand, the present inventors have found that by satisfying all of the following items, white spots and charging roller contamination in a high-temperature and high-humidity environment can be suppressed even in a configuration such as further downsizing and longer life of the apparatus. .

Below, the detail of the form of this invention is demonstrated.
The toner of the present invention contains toner particles containing a binder resin and a colorant, and small particle size inorganic particles and large particle size inorganic particles on the surface of the toner particles. The small particle size inorganic fine particles are small particle size silica fine particles, and the number average particle size (D1) of the primary particles is 5 nm or more and 20 nm or less. The large particle size inorganic fine particles are large particle size silica fine particles having a primary particle number average particle size (D1) of 25 nm or more and 100 nm or less.
In the present invention, small particle size silica particles are used as the small particle size inorganic particles, and large particle size silica particles are used as the large particle size inorganic particles. This is because silica fine particles have the best balance in terms of imparting chargeability and fluidity.
By controlling the particle size of the small particle size silica particles and large particle size silica particles within the above range, the fluidity of the toner is controlled to an appropriate state, the toner is prevented from being deteriorated, and an excellent image is obtained through durable use. provide. Furthermore, since proper fluidity can be realized with a relatively small amount of silica added, it is easy to suppress charging roller contamination.
The number average particle size (D1) of the primary particles of the small particle size silica fine particles is 5 nm or more and 20 nm or less, preferably 5 nm or more and 15 nm or less. When the number average particle size of the primary particles of the small particle size silica particles is less than 5 nm, embedding of the small particle size silica particles in the toner particles becomes remarkable, and the chargeability and fluidity are sufficiently adjusted through durable use. This is not preferable. Further, if the number average particle size of the primary particles of the small particle size silica fine particles is larger than 20 nm, it becomes difficult to obtain sufficient fluidity and chargeability, which is not preferable.
The number average particle diameter (D1) of the primary particles of the large silica particle is 25 nm or more and 100 nm or less, preferably 25 nm or more and 80 nm or less. If the large particle size silica fine particles are smaller than 25 nm, it is difficult to exhibit the spacer effect of the large particle size silica fine particles, which is not preferable. When the large particle size silica fine particles are larger than 100 nm, the release from the toner particles increases, and the charging roller contamination is worsened.

In the toner of the present invention, the content of the small particle size silica fine particles per 100 parts by mass of the toner particles is M parts by mass, and the content of the large particle size silica fine particles per 100 parts by mass of the toner particles is N parts by mass. , M and N are toners satisfying the following formulas 1 and 2.
(Formula 1) 0.6 ≦ M + N ≦ 1.5
(Formula 2) 0.2 ≦ N / M ≦ 1.3
By controlling the content of the silica fine particles within the above range, the fluidity of the toner is maintained in an appropriate state, and the effect as a spacer by the large particle size silica fine particles is most easily exhibited. M + N is preferably 0.7 ≦ M + N ≦ 1.2. Further, N / M is preferably 0.4 ≦ N / M ≦ 1.3.
When M + N is less than 0.6, it is not preferable because sufficient fluidity and chargeability cannot be imparted to the toner. When M + N is more than 1.5, free silica fine particles increase, and the charging roller contamination is worsened.
When N / M is smaller than 0.2, since there are few large-particle-size silica fine particles, a spacer effect is not seen and it is not preferable. On the other hand, when N / M = is greater than 1.3, the liberation amount of the large-diameter silica fine particles increases, so that charging roller contamination easily occurs, which is not preferable.
The M + N and N / M can be controlled by increasing or decreasing the amount of external addition of the small particle size silica particles and the large particle size silica particles.
The content of the small particle size silica fine particles per 100 parts by mass of the toner particles and the content of the large particle size silica fine particles per 100 parts by mass of the toner particles are the external addition amount of the small particle size silica fine particles and the large particle size silica fine particles, respectively. Can be adopted.

Next, the toner of the present invention defines the “external addition state of silica fine particles” as follows.
The toner of the present invention has a total coverage X1 of 40.0 area% or more, 75.0% by the small particle size silica particles and the large particle size silica particles on the toner surface, as determined by an X-ray photoelectron spectrometer (ESCA). The diffusion index represented by the following equation 3 satisfies the following equation 4 when the total theoretical coverage by the small particle silica particles and the large particle silica particles is X2. Toner.
(Formula 3) Diffusion index = X1 / X2
(Expression 4) Diffusion index ≧ −0.0042 × X1 + 0.62

The total coverage X1 can be calculated from the ratio of the Si element detection intensity when the toner is measured to the Si element detection intensity when the silica fine particles are measured by ESCA. The total coverage X1 indicates the ratio of the area of the toner particle surface that is actually covered with silica fine particles.
When the total coverage X1 is 40.0 area% or more and 75.0 area% or less, the fluidity and chargeability of the toner can be controlled in a good state. When the total coverage X1 is less than 40.0 area%, the toner is difficult to loosen and sufficient fluidity cannot be obtained. When the total coverage X1 is 75.0% by area or more, the silica fine particles that are released increase, and charging roller contamination is likely to occur.

On the other hand, the total theoretical coverage X2 by the silica fine particles is calculated by the following equation 5 using the number of parts by mass, the particle size, and the like of the small particle size silica particles and the large particle size silica particles per 100 parts by mass of the toner particles. This indicates the ratio of the area that can theoretically cover the toner particle surface.

(Formula 5) Total theoretical coverage X2 (area%)
= {3 ^1/2 / (2π) × (dt / da) × (ρt / ρa) × M × 100} + {3 ^1/2 / (2π) × (dt / db) × (ρt / ρb) × N × 100}

da: Number average particle diameter of small-diameter silica fine particles (D1)
db: Number average particle diameter of large particle silica particles (D1)
dt: weight average particle diameter of toner (D4)
ρa: True specific gravity of small particle size silica particles ρb: True specific gravity of large particle size silica particles ρt: True specific gravity of toner M: Number of parts by mass of 100 particle parts of small particle size silica particles N: Large particle size silica particles Parts by weight per 100 parts by weight of toner particles

The physical meaning of the diffusion index represented by Equation 3 is shown below. The diffusion index indicates the difference between the actually measured total coverage X1 and the theoretical total coverage X2. The degree of this divergence is considered to indicate the number of silica fine particles laminated in two and three layers in the vertical direction from the toner particle surface. Ideally, the diffusion index is 1, which is when the total coverage X1 matches the total theoretical coverage X2.
In this state, two or more layers of silica fine particles are not present at all. On the other hand, when silica fine particles are present on the toner surface as aggregated secondary particles, a difference between the actual coverage ratio and the theoretical coverage ratio occurs, resulting in a low diffusion index. In other words, the diffusion index can be paraphrased as indicating the amount of silica fine particles present as secondary particles.
In the present invention, it is important that the diffusion index is in the range represented by the above formula 4, and this range is considered to be larger than that of the toner manufactured by the conventional technique. A large diffusion index indicates that the amount of silica fine particles on the surface of the toner particles present as secondary particles is small and the amount present as primary particles is large. As described above, the upper limit of the diffusion index is 1.
When the total coverage X1 and the diffusion index satisfy the range represented by Formula 4 at the same time, the small particle size silica particles and the large particle size silica particles are more diffused to uniformly coat the toner particles. It becomes easy to unravel. At the same time, the present inventors have found that the spacer effect of the large-diameter silica fine particles can be obtained better and is effective in suppressing toner deterioration. Control of the diffusion index (diffusion of silica fine particles) is important in order to improve the fluidity of the toner by obtaining the ease of loosening of the toner and to obtain a stronger spacer effect of the large particle size silica fine particles.

So far, it has been considered that the ease of toner loosening is improved by externally adding a large amount of small-sized inorganic fine particles of about several nanometers to increase the total coverage X1. On the other hand, according to the study by the present inventors, when the ease of loosening of toners having different diffusion indexes was measured with the same total coverage X1, it became clear that there was a difference in the ease of loosening of the toner. Furthermore, it was also clarified that when the ease of loosening was measured while applying pressure, a more remarkable difference was observed. In particular, the present inventors consider that the behavior of the toner in the blade nip is more reflected on the ease of toner loosening during pressurization.
For this reason, the present inventors consider that the diffusion index is very important in addition to the total coverage X1 in order to more precisely control the ease of toner loosening during pressurization.
Next, when the total coverage X1 and the diffusion index satisfy the range represented by the formula 4 at the same time, the toner is easily loosened, and the details of the reason why the spacer effect of the large particle size silica fine particles is exerted more strongly are known. However, the present inventors presume as follows.

Depending on the coating state of the external additive, external additives such as small particle size silica particles and large particle size silica particles may aggregate together, and the aggregated external additive on the toner may mesh. (This is defined as "meshing"). When the toner is present in a narrow and high-pressure place such as a blade nip, it is considered that the toner is likely to be in an “engaged” state so that external additives existing on the surface do not collide with each other. At this time, if there are many silica fine particles present as secondary particles, the effect of meshing becomes too great, and it becomes difficult to loosen the toners quickly. In particular, when the toner is deteriorated, small-sized silica fine particles present as primary particles are embedded in the toner particles, and the fluidity of the toner is lowered. At that time, it is considered that the influence of the small particle size silica fine particles existing as secondary particles becomes large, and hinders the ease of toner loosening. Furthermore, the large particle size silica fine particles aggregate with other external additives such as the small particle size silica fine particles, which increases the influence of “meshing”, weakens the function as spacer particles, and prevents deterioration. I guess it's not enough.
Therefore, in the toner of the present invention, since many silica fine particles are present as primary particles, even when the toner deteriorates, it is difficult for the toner to bite between the toners. Each grain is very easy to loosen and gives high fluidity. In addition, the presence of many silica fine particles as primary particles makes it difficult for large particle size silica particles to form aggregates with other external additives such as small particle size silica particles, reducing the effect of "meshing". it can. As a result, the spacer effect of the large particle size silica fine particles can be obtained more strongly, and the deterioration suppressing effect can be exerted more strongly. Furthermore, toner deterioration can be suppressed with a small number of silica parts by satisfying the total amount (formula 1) and ratio (formula 2) of the above-mentioned small particle size silica particles and large particle size silica particles. Effective in suppressing roller contamination.

The boundary line of the diffusion index in the present invention is a function with the total coverage ratio X1 as a variable in the range where the total coverage ratio X1 is 40.0 area% and not more than 75.0 area%. This function was calculated as follows. First, the relationship between the total coverage X1 and the diffusion index is obtained by changing the particle size and amount of the large particle size silica particles and the small particle size silica particles, the external addition conditions, and the like. From a plot of the total coverage X1 and the diffusion index, the toner is apt to loosen easily when pressed, and the spacer effect of the large particle size silica fine particles acts strongly to improve white spots. It is a thing.
FIG. 1 shows the production of a toner in which the total coverage X1 is arbitrarily changed by changing the amount of silica fine particles to be added using three types of external additive mixing conditions, and plots the relationship between the total coverage X1 and the diffusion index. It is a graph. Among the toners plotted in this graph, the toner plotted in the region satisfying Equation 4 is sufficiently improved in the ease of loosening at the time of pressurization, and the spacer effect of the large particle size silica fine particles is more exhibited. I understood.
Here, the details of the reason why the diffusion index depends on the total coverage X1 are not known, but the present inventors presume as follows. In order to improve the ease of loosening of the toner at the time of pressurization, it is better that the amount of fine silica particles present as secondary particles is small, but the influence of the total coverage X1 is also not small. As the total coverage ratio X1 increases, the ease of loosening of the toner gradually improves, so that the allowable amount of silica fine particles present as secondary particles increases. Thus, the boundary line of the diffusion index is considered to be a function with the total coverage X1 as a variable. That is, there was a correlation between the total coverage X1 and the diffusion index, and it was experimentally determined that it is important to control the diffusion index according to the total coverage X1.
When the diffusion index is in the range of Formula 5 shown below, the amount of fine silica particles present as secondary particles increases, and toner deterioration cannot be suppressed, and the ease of toner loosening is insufficient. For this reason, the fluidity of the toner is reduced, and the large particle size silica fine particles form aggregates with the small particle size silica fine particles, so that the effect of the spacer effect of the large particle size silica fine particles becomes insufficient, thereby suppressing white spots. Is insufficient.
(Formula 5) Diffusion index <−0.0042 × X1 + 0.62

The toner of the present invention contains a binder resin. Examples of the binder resin include a vinyl resin, a polyester resin, an epoxy resin, and a polyurethane resin. It does not specifically limit and these conventionally well-known resin can be used. Among these, it is preferable to contain a polyester resin or a vinyl resin from the viewpoint of achieving both chargeability and fixability.
Specific examples and compositions of the polymerizable monomer for the polyester resin are as follows.
Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, 1,9-nonanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenol represented by the formula (A) and derivatives thereof;

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ，ｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙ平均値は０〜１０である。）
また（Ｂ）式で示されるジオール類；

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
And diols represented by the formula (B);

（ｘ’，ｙ’は、０以上の整数であり、かつ、ｘ’＋ｙ’の平均値は０〜１０である。）が挙げられる。

(X ′ and y ′ are integers of 0 or more, and the average value of x ′ + y ′ is 0 to 10).

Examples of the divalent acid component include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof, lower alkyl esters; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid. Acids or anhydrides thereof, lower alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid and n-dodecyl succinic acid, or anhydrides, lower alkyl esters thereof; fumaric acid, maleic acid, citraconic acid, itaconic acid Dicarboxylic acids such as unsaturated dicarboxylic acids or anhydrides thereof, lower alkyl esters;
In addition, a trivalent or higher alcohol component or a trivalent or higher acid component that functions as a crosslinking component may be used alone or in combination.
Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Is mentioned.
Examples of the trivalent or higher polycarboxylic acid component in the present invention include trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5, 7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Carboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, and their anhydrides, lower alkyl esters;

（式中Ｘは炭素数３以上の側鎖を１個以上有する炭素数５〜３０のアルキレン基又はアルケニレン基）
で表わされるテトラカルボン酸等、及びこれらの無水物、低級アルキルエステル等の多価カルボン酸類及びその誘導体が挙げられる。

(Wherein X is an alkylene group or alkenylene group having 5 to 30 carbon atoms having one or more side chains having 3 or more carbon atoms)
And polycarboxylic acids such as anhydrides and lower alkyl esters thereof and derivatives thereof.

The content of the alcohol component is usually 40 to 60 mol%, preferably 45 to 55 mol%. Moreover, content of an acid component is 60-40 mol% normally, Preferably it is 55-45mo.
1%.
The polyester resin is usually obtained by a generally known condensation polymerization.

Further, the binder resin may contain a vinyl resin.
Examples of the polymerizable monomer (vinyl monomer) for producing the vinyl resin include the following.
Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethyl Styrene such as styrene, pn-butyl styrene, p-tert butyl styrene, pn hexyl styrene, pn octyl styrene, pn nonyl styrene, pn decyl styrene, pn dodecyl styrene and derivatives thereof Styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl acetate; Vinyl such as vinyl propionate and vinyl benzoate Stealth; methyl methacrylate, ethyl methacrylate, propyl methacrylate, nbutyl methacrylate, isobutyl methacrylate, n octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylamino methacrylate Α-methylene aliphatic monocarboxylic acid esters such as ethyl and diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, acrylic Acrylic acid esters such as 2-ethylhexyl acid, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl methyl ether, vinyl ethyl ether, Vinyl ethers such as vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone Vinyl naphthalenes; and acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

Further, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Unsaturated dibasic acid half esters such as alkenyl succinic acid methyl half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester; dimethyl maleic acid, unsaturated dibasic acid ester such as dimethyl fumaric acid; acrylic acid, Α, β-unsaturated acids such as phosphoric acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic anhydride and cinnamic anhydride, the α, β-unsaturated acids and lower fatty acids And monomers having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.
Furthermore, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

In the toner of the present invention, the vinyl resin of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. Examples of the crosslinking agent used in this case include divinylbenzene and divinylnaphthalene as aromatic divinyl compounds; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate and 1,3-butylene glycol diene. Acrylate, 1,4-butanediol diacrylate, 1,5-pentanediol acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylate of the above compounds with methacrylate Examples of diacrylate compounds linked by an alkyl chain containing an ether bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, poly Tylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and the above compounds in which acrylate is replaced with methacrylate; chain containing aromatic group and ether bond Examples of diacrylate compounds include polyoxyethylene (2) -2,2-bis (4hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4hydroxyphenyl) propanedi Examples of the polyester type diacrylate compounds include trade name MANDA (Nippon Kayaku Co., Ltd.).

Examples of the polyfunctional cross-linking agent include pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, and those obtained by replacing the acrylate of the above compounds with methacrylate; And allyl cyanurate and triallyl trimellitate.
These crosslinking agents can usually be used in an amount of 0.01 to 10 parts by mass (preferably 0.03 to 5 parts by mass) with respect to 100 parts by mass of monomer components other than the crosslinking agent.
Among these crosslinkable monomers, those which are preferably used in the binder resin from the viewpoint of fixability and offset resistance are bonded with aromatic divinyl compounds (particularly divinylbenzene), chains containing aromatic groups and ether bonds. And diacrylate compounds.

Examples of the polymerization initiator used when producing a vinyl resin as the binder resin include 2,2′-azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2,4).
-Dimethylvaleronitrile), 2,2'-azobis (-2,4-dimethylvaleronitrile), 2,2'-azobis (-2methylbutyronitrile), dimethyl-2,2'-azobisisobutyrate 1,1′-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4 -Dimethyl-4-methoxyvaleronitrile, 2,
Ketone peroxides such as 2-azobis (2-methylpropane), methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene Hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α'-bis (t-butylperoxide Oxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-triois Peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, dimethoxyisopropyl peroxydicarbonate, di ( 3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, t-butylperoxy 2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxy -Oxyallyl carbonate, t-amylperoxy 2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate.

The binder resin according to the present invention has a glass transition temperature (Tg) of usually 45 ° C. or higher and 70 ° C. or lower, preferably 50 ° C. or higher and 70 ° C. or lower, from the viewpoint that both low-temperature fixability and storage stability are easily achieved. It is.
When Tg is less than 45 ° C., storage stability tends to deteriorate. Moreover, when Tg is higher than 70 ° C., the low-temperature fixability tends to be deteriorated.

The toner particles of the present invention contain a colorant.
Examples of the colorant preferably used in the present invention include the following.
Examples of organic pigments or organic dyes as cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds.
Examples of the organic pigment or organic dye as the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds.
Examples of the organic pigment or organic dye as the yellow colorant include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.
Examples of the black colorant include carbon black, the above-described yellow colorant, magenta colorant, and cyan colorant that are toned to black.
When a colorant is used, it is preferably used by adding 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the polymerizable monomer or binder resin.

The toner particles of the present invention can contain a magnetic material. In the present invention, the magnetic material can also serve as a colorant.
The magnetic material used in the present invention is mainly composed of triiron tetroxide or γ-iron oxide, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, and aluminum. The shape of the magnetic material includes a polyhedron, octahedron, hexahedron, sphere, needle shape, and flake shape. It is preferable in terms of enhancement. The content of the magnetic substance in the present invention is preferably 50 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer or binder resin.

The toner particles of the present invention preferably contain a wax. The wax preferably includes a hydrocarbon wax. Other waxes include the following. Amide waxes, higher fatty acids, long chain alcohols, ketone waxes, ester waxes, and derivatives such as these graft compounds and block compounds. If necessary, two or more kinds of waxes may be used in combination. Among these, when the hydrocarbon wax by the Fischer-Tropsch method is used, the high temperature offset resistance can be kept good while maintaining the developability well for a long time. These hydrocarbon waxes may contain an antioxidant within a range that does not affect the chargeability of the toner.
The content of the wax is preferably 4.0 parts by mass or more and 30.0 parts by mass or less, more preferably 4.0 parts by mass or more and 28.0 parts by mass with respect to 100 parts by mass of the binder resin. It is as follows.

In the toner of the present invention, a charge control agent can be contained in the toner particles as necessary. By blending the charge control agent, the charge characteristics are stabilized, and the optimum triboelectric charge amount according to the development system can be controlled.
As the charge control agent, a known one can be used, and a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner particles are produced by a direct polymerization method, a charge control agent having a low polymerization inhibition property and substantially free from a solubilized product in an aqueous medium is particularly preferable. As the charge control agent, Spiron Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-84, E-88, E -89 (Orient Chemical Co., Ltd.), modified products of nigrosine and fatty acid metal salts, etc .; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Onium salts such as phosphonium salts, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (as rake agents, phosphotungstic acid, phosphomolybthenic acid, phosphotungsten molybthenic acid, tannic acid, lauric acid) , Gallic acid, ferricyanic acid, ferrocyanic compounds, etc.) Metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; organotin borates such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, TP-302, TP-415 (Hodogaya Chemical) Co., Ltd.), BONTRON (registered trademark) N-01, N-04, N-07, P-51 (Orient Chemical), and Copy Blue PR (Clariant).
The toner of the present invention can contain these charge control agents alone or in combination of two or more.
The blending amount of the charge control agent is preferably 0.3 parts by mass or more and 10.0 parts by mass or less, more preferably 0.5 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin. Part or more and 8.0 parts by weight or less.

The toner of the present invention contains toner particles and inorganic fine particles. In the present invention, the inorganic fine particles are at least two types of small particle size silica particles and large particle size silica particles, but other particles may be added within a range not impairing the effects of the present invention.
In the present invention, the silica base of the small particle size silica particles and the large particle size silica particles is, for example, a so-called dry method or dry silica called fumed silica produced by vapor phase oxidation of a silicon halide, and Both so-called wet silica produced from water glass or the like can be used.
The small particle size silica particles and the large particle size silica particles used in the present invention are preferably hydrophobized with at least one of alkoxysilane and / or silazane and silicone oil. The above-mentioned small particle size silica fine particles and large particle size silica fine particles may be hydrophobized with any one of alkoxysilane and / or silazane and silicone oil, or may be treated with both. When treated by both, the silica base material can be subjected to a hydrophobizing reaction of alkoxysilane and / or silazane or silicone oil. Any order may be first.
The small particle size silica particles and the large particle size silica particles used in the present invention may be crushed during the treatment step or after the treatment step. Furthermore, when performing a two-stage process, it is also possible to perform a crushing process between processes.
The degree of hydrophobic treatment of the small particle size silica particles and the large particle size silica particles used in the present invention is such that the hydrophobicity described later is 70% or more and 100% or less from the viewpoint of suppressing a decrease in chargeability in a high temperature and high humidity environment. It is preferable that it is 80% or more and 100% or less.
Moreover, it is desirable that the small particle size silica fine particles used in the present invention be hydrophobized with 5 to 40.0 parts by mass of silicone oil with respect to 100 parts by mass of the silica raw material. Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil. The hydrophobicity can be adjusted by increasing or decreasing the amount of silicone oil treated.

  In the present invention, the kinematic viscosity at 25 ° C. of the silicone oil used for the treatment of the small particle size silica fine particles is preferably 30 cSt or more and 500 cSt or less. When the kinematic viscosity is in the above range, it is easy to control uniformly when the silica base is hydrophobized with silicone oil. Furthermore, the kinematic viscosity of the silicone oil is closely related to the molecular chain length of the silicone oil, and when the kinematic viscosity is in the above range, it is easy to control the degree of aggregation of the small particle size silica fine particles to a suitable range. ,preferable. A more preferable range of the kinematic viscosity at 25 ° C. of the silicone oil is 40 cSt or more and 300 cSt or less. Examples of the apparatus for measuring the kinematic viscosity of silicone oil include a capillary type kinematic viscometer (manufactured by Kashiwagi Scientific Instruments Co., Ltd.) or a fully automatic microkinematic viscometer (manufactured by Viscotech Co., Ltd.).

  The small particle size silica fine particles used in the present invention are preferably those obtained by treating the silica raw material with silicone oil and then treating with at least one of alkoxysilane and silazane. Since the surface of the untreated silica base material remaining by this treatment can be hydrophobized, silica particles having a high hydrophobicity can be stably obtained. Further, it is preferable to process in this order because the ease of toner loosening can be greatly improved. Although details of the reason why the ease of unraveling can be improved are not clear, the present inventors consider as follows. Of the silicone oil molecule ends on the surface of the small particle size silica fine particles, only one end has a degree of freedom, which affects the cohesion of the small particle size silica fine particles. On the other hand, by carrying out the two-stage treatment as described above, the silicone oil molecular ends are hardly present on the outermost surface of the small particle size silica fine particles, so that the cohesiveness of the small particle size silica fine particles can be further reduced. As a result, the cohesiveness between the toners when externally added can be greatly reduced, and the ease of toner loosening can be improved.

The surface treatment with the silicone oil and the surface treatment with the alkoxysilane and silazane may be either a dry treatment or a wet treatment. The specific procedure of the surface treatment with the silicone oil of the silica raw material is, for example, by reacting the silica fine particles in a solvent (preferably adjusted to pH 4 with an organic acid or the like) in which the silicone oil is dissolved. Remove.
Subsequently, as a specific procedure when performing surface treatment with at least one of alkoxysilane and silazane, crushed silicone oil-treated silica fine particles are placed in a solvent in which at least one of alkoxysilane and silazane is dissolved. Then, the solvent is removed and pulverization is performed.
Further, the following method may be used. For example, in the surface treatment with silicone oil, silica fine particles are put into a reaction vessel. Then, alcohol water is added with stirring in a nitrogen atmosphere, silicone oil is introduced into the reaction tank to perform surface treatment, and the mixture is further heated and stirred to remove the solvent, followed by crushing treatment. In the surface treatment with at least one of alkoxysilane and silazane, the surface treatment is performed by introducing at least one of alkoxysilane and silazane while stirring in a nitrogen atmosphere, and further, the mixture is heated and stirred to remove the solvent and then cooled. Preferred examples of the alkoxysilane include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, and phenyltriethoxysilane. On the other hand, hexamethyldisilazane can be preferably exemplified as silazane. The treatment amount with at least one of these alkoxysilanes and silazanes is 0.1 parts by mass or more and 20.0 parts by mass or less as a total amount of at least one of alkoxysilanes and silazanes with respect to 100 parts by mass of the silica raw material.

After the above silicone oil treatment, the small particle size silica fine particles treated with at least one of alkoxysilane and silazane preferably have a carbon oil-based immobilization ratio of 70% by mass or more and 100% by mass or less, More preferably, it is 90 mass% or more and 100 mass% or less. When the immobilization ratio is within the above range, aggregation due to the above-mentioned small particle size silica fine particles is suppressed, and the “meshing” between the toners can be reduced. It is easy to be done.
In order to increase the carbon oil-based immobilization rate of the above-mentioned small particle size silica fine particles, the silicone oil is chemically immobilized on the surface of the silica base material in the process of obtaining the above small particle size silica fine particles. It is necessary to let For this purpose, a method of performing a heat treatment for the reaction of the silicone oil in the process of obtaining the small particle size silica fine particles can be suitably exemplified. The heat treatment temperature is preferably 100 ° C. or higher. The higher the heat treatment temperature, the higher the immobilization rate. This heat treatment step is preferably performed immediately after the silicone oil treatment, but when the crushing treatment is performed, the heat treatment step may be performed after the crushing treatment step.
The small particle size silica fine particles used in the present invention may be crushed during the treatment step or after the treatment step. Furthermore, when performing a two-stage process, it is also possible to perform a crushing process between processes.
The toner particles according to the present invention preferably have a weight average particle diameter (D4) of 5.0 μm or more and 10.0 μm or less, more preferably 5.5 μm or more, from the viewpoint of a balance between developability and fixability. It is 9.5 μm or less.

In the present invention, the average circularity of the toner particles is preferably 0.960 or more, and more preferably 0.970 or more. When the average circularity of the toner particles is 0.960 or more, the shape of the toner is a sphere or a shape close to this, and it is easy to obtain a uniform triboelectric chargeability with excellent fluidity. Therefore, it is preferable because it becomes easy to maintain high developability even in the latter half of durable use. In addition, toner particles having a high average circularity are preferable because the total coverage X1 and the diffusion index can be easily controlled within the range of the present invention in the external addition mixing process of inorganic fine particles described later. Further, from the viewpoint of ease of loosening of the toner at the time of pressurization, it is preferable because the meshing effect on the surface shape of the toner particles hardly occurs and the ease of loosening can be further improved. In particular, as an index for judging uniformity, it is possible to know qualitatively or semi-quantitatively by microscopic observation or the like. The index tends to correlate with toner circulation with higher accuracy.
Production of toner particles in an aqueous medium, which will be described later, makes it easy to control the average circularity within the above range. In the case of production of toner particles by a pulverization method, it is easy to control to the above range by performing a thermal spheronization process, surface modification, and fine powder removal.

Hereinafter, the toner production method of the present invention will be exemplified, but the present invention is not limited thereto.
The method for producing the toner of the present invention is not particularly limited, and can be produced by a known method.
When the toner particles are produced by a pulverization method, for example, a binder resin and a colorant, and, if necessary, other additives such as wax are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill. Thereafter, the toner material is dispersed or dissolved by using a heat kneader such as a heating roll, a kneader, and an extruder to disperse or dissolve the toner material. After cooling and solidification, pulverization, classification, and if necessary, surface treatment is performed to obtain toner particles. obtain. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.
The pulverization can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. Further, in order to obtain toner particles having a preferable average circularity of the present invention, it is preferable to further pulverize by applying heat or to add a mechanical impact force supplementarily. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.
Examples of means for applying a mechanical impact force include a method using a mechanical impact pulverizer such as a kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industry. Further, there is a method of applying a mechanical impact force to the toner particles by a force such as a compressive force or a frictional force, such as a device such as a mechano-fusion system manufactured by Hosokawa Micron Corporation or a hybridization system manufactured by Nara Machinery Co., Ltd.

The toner particles used in the present invention are preferably those produced in an aqueous medium such as a dispersion polymerization method, an association aggregation method, a solution suspension method, and a suspension polymerization method. It is more preferable that In the case of production in an aqueous medium, for example, a polymerizable monomer composition containing a polymerizable monomer and a colorant is dispersed in an aqueous medium, granulated, and contained in the granulated particles. Toner particles can be obtained by polymerizing the polymerizable monomer.
In the suspension polymerization method, first, a polymerizable monomer and a colorant, and if necessary, other additives such as a polymerization initiator, a crosslinking agent and a charge control agent are uniformly dissolved or dispersed for polymerization. A functional monomer composition is obtained. Thereafter, the polymerizable monomer composition is dispersed in a continuous layer (for example, an aqueous phase) containing a dispersion stabilizer using a suitable stirrer, and then the polymerizable monomer in the polymerizable monomer composition is used. The toner is polymerized to obtain toner particles having a desired particle size. The toner particles obtained by this suspension polymerization method (hereinafter also referred to as “polymerized toner particles”) are easy to satisfy a predetermined average circularity since the individual toner particle shapes are substantially spherical. Further, it is preferable because the distribution of the charge amount of the toner particles becomes relatively uniform.
As the polymerizable monomer constituting the polymerizable monomer composition, known ones can be used in addition to those exemplified as the vinyl monomer. Among these, styrene or a styrene derivative is preferably used alone or mixed with another polymerizable monomer from the viewpoint of the development characteristics and durability of the toner.
In the present invention, the polymerization initiator used in the suspension polymerization method preferably has a half-life of 0.5 hours or more and 30.0 hours or less during the polymerization reaction. Moreover, it is preferable that the addition amount of a polymerization initiator is 0.5 to 20.0 mass parts with respect to 100 mass parts of polymerizable monomers.
Specific examples of the polymerization initiator are preferably those described above, azo or diazo polymerization initiators, peroxide polymerization initiators, and the like.
In the suspension polymerization method, the cross-linking agent may be added during the polymerization reaction, and a preferable addition amount is 0.1 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. It is.
Here, as the crosslinking agent, a compound mainly having two or more polymerizable double bonds is preferred. For example, as described above, an aromatic divinyl compound, a carboxylic acid ester having two double bonds, a divinyl compound, and a compound having three or more vinyl groups are preferable. These can be used alone or as a mixture of two or more.

Hereinafter, the production of toner particles by the suspension polymerization method will be specifically described, but the present invention is not limited thereto. First, the above-mentioned polymerizable monomer and coloring agent are added as appropriate, and the polymerizable monomer composition uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, or an ultrasonic disperser is dispersed. It is granulated by suspending in an aqueous medium containing a stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size all at once. The polymerization initiator may be added at the same time as other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.
After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and particle floating and sedimentation are prevented.

As the dispersion stabilizer, known surfactants, organic dispersants, or inorganic dispersants can be used. In particular, inorganic dispersants are less likely to produce harmful ultrafine powders, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and cleaning is easy and adversely affects toner particles. Since it is difficult, it can be preferably used. Examples of such inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, phosphate polyvalent metal salts such as hydroxyapatite, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate, Examples thereof include inorganic salts such as barium sulfate and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.
These inorganic dispersants are preferably used in an amount of 0.20 parts by mass or more and 20.00 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Moreover, the said dispersion stabilizer may be used independently and may use multiple types together. Furthermore, you may use together 0.0001 mass part or more and 0.1000 mass part or less surfactant with respect to 100 mass parts of polymerizable monomers.
In the polymerization reaction of the polymerizable monomer, the polymerization temperature is set to 40 ° C. or higher, generally 50 ° C. or higher and 90 ° C. or lower.
After the polymerization of the polymerizable monomer is completed, the obtained polymer particles are filtered, washed and dried by a known method to obtain toner particles. The toner of the present invention is obtained by adding inorganic fine particles to the toner particles and adhering them to the surface of the toner particles.
It is also possible to add a classification step to the production process (before mixing the inorganic fine particles) to remove coarse powder and fine powder contained in the toner particles.
The toner of the present invention contains small particle size silica particles and large particle size silica particles as inorganic particles, but other particles may be used as long as the effects of the present invention are not impaired. In this case, particles having a number average particle diameter (D1) of primary particles of 80 nm or more and 3 μm or less may be added. For example, a lubricant such as fluororesin powder, zinc stearate powder, polyvinylidene fluoride powder; abrasives such as cerium oxide powder, silicon carbide powder, strontium titanate powder, etc. should be used in a small amount so as not to affect the effect of the present invention. You can also.

As a mixing processing apparatus for externally mixing the silica fine particles, a known mixing processing apparatus can be used, but an apparatus as shown in FIG. 2 is preferable in that the total coverage X1 and the diffusion index can be easily controlled.
FIG. 2 is a schematic view showing an example of a mixing treatment apparatus that can be used when externally mixing the small particle size silica particles and the large particle size silica particles used in the present invention.
The mixing processing apparatus is configured to take a share in the narrow clearance portion with respect to the toner particles, the small particle size silica particles, and the large particle size silica particles. For this reason, it is possible to adhere to the toner particle surfaces while loosening the large particle size silica particles and the small particle size silica particles from the secondary particles to the primary particles. By loosening the large particle size silica particles and the small particle size silica particles into primary particles, the total coverage X1 and the diffusion index can be easily controlled within a preferable range.
Further, as will be described later, in the axial direction of the rotator, the toner particles, the small particle size silica particles and the large particle size silica particles are easily circulated, and the total coverage ratio is easily mixed sufficiently before the fixing proceeds. X1 and the diffusion index can be easily controlled within the preferred ranges in the present invention.

On the other hand, FIG. 3 is a schematic diagram showing an example of a configuration of a stirring member used in the mixing processing apparatus. Hereinafter, the external addition mixing process of the small particle size silica fine particles and the large particle size silica fine particles will be described with reference to FIGS.
The mixing treatment apparatus for externally mixing the small particle size silica particles and the large particle size silica particles includes a rotating body 2 having at least a plurality of stirring members 3 installed on a surface thereof, a driving unit 8 that rotationally drives the rotating body, The main body casing 1 is provided with a stirring member 3 and a gap.
The clearance (clearance) between the inner peripheral portion of the main body casing 1 and the stirring member 3 gives a uniform share to the toner particles, and loosens the small particle size silica particles and the large particle size silica particles from the secondary particles to the primary particles. However, in order to easily adhere to the toner particle surface, it is important to keep it constant and minute.
Further, in this apparatus, the diameter of the inner peripheral portion of the main body casing 1 is not more than twice the diameter of the outer peripheral portion of the rotating body 2. 2 shows an example in which the diameter of the inner peripheral portion of the main body casing 1 is 1.7 times the diameter of the outer peripheral portion of the rotating body 2 (the diameter of the body portion obtained by removing the stirring member 3 from the rotating body 2). If the diameter of the inner peripheral portion of the main body casing 1 is less than or equal to twice the diameter of the outer peripheral portion of the rotating body 2, the processing space in which the force acts on the toner particles is appropriately limited. A sufficient impact force is applied to the small particle size silica particles and the large particle size silica particles.

It is important to adjust the clearance according to the size of the main casing. Setting the diameter of the inner peripheral portion of the main casing 1 to about 1% or more and 5% or less is important in terms of applying a sufficient share to the small particle size silica particles and the large particle size silica particles. Specifically, when the diameter of the inner peripheral part of the main body casing 1 is about 130 mm, the clearance is about 2 mm or more and about 5 mm or less, and when the diameter of the inner peripheral part of the main body casing 1 is about 800 mm, it is about 10 mm or more. What is necessary is just to be about 30 mm or less.
In the external addition mixing step of the small particle size silica particles and the large particle size silica particles in the present invention, the rotating body 2 is rotated by the drive unit 8 using a mixing apparatus. Then, the toner particles and silica fine particles put in the mixing treatment device are stirred and mixed, and the surface of the toner particles is externally mixed with the small particle size silica fine particles and the large particle size silica fine particle silica particles.
As shown in FIG. 3, at least a part of the plurality of agitating members 3 causes toner particles, small-diameter silica fine particles, and large-diameter silica fine particles to move in one axial direction of the rotary body as the rotary body 2 rotates. Formed as a feed stirring member 3a. Further, at least a part of the plurality of agitating members 3 is used for returning the toner particles, the small particle size silica particles, and the large particle size silica particles to the other direction in the axial direction of the rotating body as the rotating body 2 rotates. It is formed as a stirring member 3b.
Here, when the raw material inlet 5 and the product outlet 6 are provided at both ends of the main casing 1 as shown in FIG. 2, the direction from the raw material inlet 5 toward the product outlet 6 (in FIG. 2). (Right direction) is called “feed direction”.
That is, as shown in FIG. 3, the plate surface of the feeding stirring member 3a is inclined so as to feed the toner particles in the feeding direction (13). On the other hand, the plate surface of the stirring member 3b is inclined so as to send the toner particles, the small particle size silica particles and the large particle size silica particles in the return direction (12).
Thus, the external addition of the small particle size silica particles and the large particle size silica particles is performed on the surface of the toner particles while repeatedly performing the feed (13) in the “feed direction” and the feed (12) in the “return direction”. Mixing is performed.

The stirring members 3a and 3b are a set of a plurality of members arranged at intervals in the circumferential direction of the rotating body 2. In the example shown in FIG. 3, the stirring members 3a and 3b form a pair of two members on the rotating body 2 at an interval of 180 degrees, but three members at an interval of 120 degrees or an interval of 90 degrees. It is good also as a set of many members, such as four sheets.
In the example shown in FIG. 3, a total of 12 stirring members 3a and 3b are formed at equal intervals.
Further, in FIG. 3, D indicates the width of the stirring member, and d indicates the interval indicating the overlapping portion of the stirring member. From the viewpoint of efficiently feeding toner particles, small particle size silica particles, and large particle size silica particles in the feed direction and the return direction, D is 20% or more and 30% or less with respect to the length of the rotating body 2 in FIG. It is preferable that the width is of the order. In FIG. 3, an example of 23% is shown. Furthermore, it is preferable that the stirring members 3a and 3b have some overlap d between the stirring member 3b and the stirring member when an extension line is drawn in the vertical direction from the end position of the stirring member 3a. As a result, it is possible to efficiently share the small particle size silica particles and the large particle size silica particles that are secondary particles. It is preferable that d is 10% or more and 30% or less with respect to D in terms of applying a share.
Regarding the shape of the blade, in addition to the shape shown in FIG. 3, if the toner particles can be fed in the feeding direction and the returning direction and the clearance can be maintained, the shape having a curved surface and the tip blade portion are A paddle structure coupled to the rotating body 2 with a rod-like arm may be used.

Hereinafter, the present invention will be described in more detail with reference to the schematic views of the apparatus shown in FIGS.
The apparatus shown in FIG. 2 includes a rotating body 2 having at least a plurality of stirring members 3 installed on the surface thereof, a drive unit 8 that rotationally drives the rotating body 2, and a main body casing that is provided with a gap between the stirring member 3 1 and a jacket 4 on the inner side of the main body casing 1 and the side surface 10 of the rotating body end, through which a cooling medium can flow.
Further, the apparatus shown in FIG. 2 uses a raw material charging port 5 formed on the upper portion of the main casing 1 to introduce toner particles, small-sized silica fine particles, and large-sized silica fine particles. In order to discharge from the main casing 1 to the outside, a product discharge port 6 formed at the lower portion of the main casing 1 is provided.
Furthermore, in the apparatus shown in FIG. 2, a raw material inlet inner piece 16 is inserted into the raw material inlet 5, and a product outlet inner piece 17 is inserted into the product outlet 6.

In the present invention, first, the raw material inlet inner piece 16 is taken out from the raw material inlet 5, and the toner particles are put into the processing space 9 from the raw material inlet 5. Next, small particle silica fine particles and large particle silica fine particles are charged into the treatment space 9 from the raw material inlet 5, and the raw material inlet inner piece 16 is inserted. Next, the rotating body 2 is rotated by the drive unit 8 (11 indicates the direction of rotation), and the processed material introduced above is externally added while being stirred and mixed by a plurality of stirring members 3 provided on the surface of the rotating body 2. Mix.
It should be noted that the order of introduction may be such that the small particle size silica particles and the large particle size silica particles are first charged from the raw material input port 5 and then the toner particles are input from the raw material input port 5. Further, after the toner particles, the small particle size silica particles and the large particle size silica particles are mixed in advance by a mixer such as a Henschel mixer, the mixture may be charged from the raw material inlet 5 of the apparatus shown in FIG. Absent.
More specifically, controlling the power of the drive unit 8 to be 0.2 W / g or more and 2.0 W / g or less as the external addition mixing process condition is that the total coverage X1 and diffusion defined in the present invention are defined. It is preferable for obtaining an index. Moreover, it is more preferable to control the power of the drive unit 8 to 0.6 W / g or more and 1.6 W / g or less.
When the power is lower than 0.2 W / g, the total coverage X1 is difficult to increase and the diffusion index tends to be too low. On the other hand, when it is higher than 2.0 W / g, the diffusion index becomes high, but the small-diameter silica fine particles tend to be embedded too much.

Although it does not specifically limit as processing time, Preferably it is 3 minutes or more and 10 minutes or less. When the treatment time is shorter than 3 minutes, the total coverage X1 and the diffusion index tend to be low.
No particular limitation is imposed on the rotational speed of the external addition during mixing the stirring member, Figure 3 in the apparatus of volume 2.0 × 10 ^-3 m ³ of processing space 9 in the apparatus shown in FIG. 2, the shape of the stirring member 3 The number of rotations of the stirring member is preferably 800 rpm or more and 3000 rpm or less. By being 800 rpm or more and 3000 rpm or less, it becomes easy to obtain the total coverage X1 and the diffusion index defined in the present invention.
Further, in the present invention, a particularly preferable processing method is to have a pre-mixing step before the external addition mixing processing operation. By including the pre-mixing step, the small particle size silica particles and the large particle size silica particles are highly uniformly dispersed on the toner particle surface. Therefore, the total coverage X1 tends to be high, and the diffusion index is likely to be high.

More specifically, as pre-mixing processing conditions, the power of the drive unit 8 is set to 0.06 W / g or more and 0.20 W / g or less, and the processing time is set to 0.5 minutes or more and 1.5 minutes or less. It is preferable. If the load power is lower than 0.06 W / g or the processing time is shorter than 0.5 minutes as the premixing processing condition, sufficient uniform mixing is difficult to perform as premixing. On the other hand, if the load power is higher than 0.20 W / g or the processing time is longer than 1.5 minutes as the pre-mixing processing conditions, a small particle size silica is formed on the surface of the toner particles before sufficient uniform mixing. Fine particles and large-diameter silica fine particles may be fixed.
Regarding the rotation speed of the stirring member in the pre-mixing process, when the volume of the processing space 9 of the apparatus shown in FIG. 2 is 2.0 × 10 ⁻³ m ³ and the shape of the stirring member 3 is as shown in FIG. The rotation speed of the stirring member is preferably 50 rpm or more and 500 rpm or less. By being 50 rpm or more and 500 rpm or less, it becomes easy to obtain the total coverage X1 and the diffusion index specified in the present invention.
After completion of the external addition mixing process, the product discharge port inner piece 17 is taken out from the product discharge port 6, the rotating body 2 is rotated by the drive unit 8, and the toner is discharged from the product discharge port 6. From the obtained toner, coarse particles and the like are separated by a sieve such as a circular vibration sieve as necessary to obtain a toner.

  Next, an example of an image forming apparatus that can suitably use the toner of the present invention will be described in detail with reference to FIG. In FIG. 4, reference numeral 100 denotes an electrostatic latent image carrier (hereinafter also referred to as a photoconductor), which includes a charging member (charging roller) 117, a developing device 140 having a toner carrier 102, a transfer member (transfer charging roller). ) 114, a cleaner container 116, a fixing device 126, a pickup roller 124, and the like. The electrostatic latent image carrier 100 is charged by the charging roller 117. Then, exposure is performed by irradiating the electrostatic latent image carrier 100 with laser light from the laser generator 121, and an electrostatic latent image corresponding to the target image is formed. The electrostatic latent image on the electrostatic latent image carrier 100 is developed with a one-component toner by the developing device 140 to obtain a toner image, and the toner image is transferred in contact with the electrostatic latent image carrier via a transfer material. The image is transferred onto the transfer material by the roller 114. The transfer material on which the toner image is placed is conveyed to the fixing device 126 and fixed on the transfer material. Further, the toner partially left on the electrostatic latent image carrier is scraped off by the cleaning blade and stored in the cleaner container 116.

Next, it describes regarding the measuring method of each physical property which concerns on this invention.
<Measurement method of total coverage X1>
The total coverage X1 by the small particle size silica particles and the large particle size silica particles on the toner surface is calculated as follows.
The following apparatus is used under the following conditions, and elemental analysis of the toner surface is performed.
-Measuring device: Quantum 2000 (trade name, manufactured by ULVAC-PHI Co., Ltd.)
・ X-ray source: Monochrome Al Kα
-Xray Setting: 100 μmφ (25 W (15 KV))
・ Photoelectron extraction angle: 45 degrees ・ Neutralization condition: Combined use of neutralizing gun and ion gun ・ Analysis area: 300 × 200 μm
・ Pass Energy: 58.70eV
・ Step size: 1.25eV
・ Analysis software: Maltipak (PHI)
Here, C 1c (BE 280 to 295 eV), O
Peaks of 1 s (B.E. 525-540 eV) and Si 2p (B.E. 95-113 eV) were used. The quantitative value of the Si element obtained here is Y1.
Subsequently, the small particle size silica fine particles and the large particle size silica fine particles used for external addition to the toner particles are measured. The quantitative value of the Si element of the small particle size silica fine particle obtained here is Y2, and the Si element Y3 of the large particle size silica fine particle simple substance.

In the present invention, the total coverage X1 by the small particle size silica particles and the large particle size silica particles on the toner surface is defined as follows.
Total coverage X1 (area%) = Y1 / {(Y2 × M / (M + N) + Y3 × N / (M + N)} × 100
M: parts by mass per 100 parts by mass of small particle size silica fine particles N: parts by mass per 100 parts by mass of large particle size silica fine particles In order to improve the accuracy of this measurement, Y1, Y2, It is preferable to measure Y3 twice or more.

<Method for Measuring Toner Weight Average Particle Size (D4)>
The weight average particle diameter (D4) of the toner is calculated as follows (also calculated in the case of toner particles). As a measuring device, a precision particle size distribution measuring device “Coulter Counter Multisizer by a pore electric resistance method equipped with an aperture tube of 100 μm” is used.
3 "(registered trademark, manufactured by Beckman Coulter, Inc.) is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels.
As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

Prior to measurement and analysis, the dedicated software is set as follows.
On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.
In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dispersion System Tetora 150” (manufactured by Nikkaki Bios) with an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker (1) installed in the sample stand, the electrolytic solution (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle diameter (D4).

<Measurement Method of Number Average Particle Size (D1) of Primary Particles of Small Particle Size Silica Fine Particles and Large Particle Size Silica Fine Particles>
The number average particle size of the primary particles of the small particle size silica particles and the large particle size silica particles is a small particle size photographed by Hitachi Ultra High Resolution Field Emission Scanning Electron Microscope S-4800 (Hitachi High-Technologies Corporation). It is calculated from the silica fine particle and large particle size silica fine particle images. The image capturing conditions of S-4800 are as follows.
(1) Sample preparation A conductive paste is thinly applied to a sample table (aluminum sample table 15 mm × 6 mm), and small particle size silica particles and large particle size silica particles are sprayed thereon. Further, air is blown to remove excess small particle size silica particles and large particle size silica particles from the sample stage and sufficiently dry. The sample stage is set on the sample holder, and the height of the sample stage is adjusted to 36 mm by the sample height gauge. (2) S-4800 Observation Condition Setting The number average particle size of the primary particles of the small particle size silica particles and the large particle size silica particles is calculated using the image obtained by the reflected electron image observation of S-4800. Since the reflected electron image has less charge-up of the small particle size silica particles and the large particle size silica particles compared to the secondary electron image, the particle size of the silica particle can be measured with high accuracy.
Pour liquid nitrogen into the anti-contamination trap attached to the S-4800 enclosure until it overflows, and leave it for 30 minutes. S-4800 “PCSTEM” is activated and flushing (cleaning of the FE chip as an electron source) is performed. Click the acceleration voltage display part of the control panel on the screen and press the [Flushing] button to open the flushing execution dialog. Confirm that the flushing intensity is 2 and execute. Confirm that the emission current by flashing is 20-40 μA. Insert the sample holder into the sample chamber of the S-4800 housing. Press [Origin] on the control panel to move the sample holder to the observation position.
Click the acceleration voltage display section to open the HV setting dialog, and set the acceleration voltage to [0.8 kV] and the emission current to [20 μA]. In the [Basic] tab of the operation panel, set the signal selection to [SE], select [Up (U)] and [+ BSE] for the SE detector, and select [+ BSE] in the selection box on the right. L. A. 100] to select a mode in which observation is performed with a reflected electron image. Similarly, in the [Basic] tab of the operation panel, the probe current of the electron optical system condition block is set to [Normal], the focus mode is set to [UHR], and the WD is set to [3.0 mm]. Press the [ON] button in the acceleration voltage display section of the control panel to apply the acceleration voltage.
(3) Calculation of number average particle diameter (D1) of primary particles of small particle size silica particles and large particle size silica particles Drag within the magnification display portion of the control panel to set the magnification to 100000 (100k) times. The focus knob [COARSE] on the operation panel is rotated, and the aperture alignment is adjusted when the focus is achieved to some extent. Click [Align] on the control panel to display the alignment dialog and select [Beam]. The STIGMA / ALIGNMENT knob (X, Y) on the operation panel is rotated to move the displayed beam to the center of the concentric circle. Next, [Aperture] is selected, and the STIGMA / ALIGNMENT knobs (X, Y) are turned one by one to stop the movement of the image or adjust the movement to the minimum. Close the aperture dialog and focus with auto focus. Repeat this operation two more times to focus.
Thereafter, the average particle size is determined by measuring the particle size of at least 300 small particle silica particles and large particle silica particles. Here, since the small particle size silica particles and the large particle size silica particles exist as aggregates, the maximum diameter of what can be confirmed as primary particles is obtained. The number average particle size (D1) of the primary particles of the small particle size silica particles and the large particle size silica particles is obtained by arithmetically averaging the maximum diameters obtained there.

<Measuring method of average circularity of toner particles>
The average circularity of the toner particles is measured by a flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.
A specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids are removed in advance is put in a glass container. In this, “Contaminone N” is used as a dispersant.
”(10% by weight aqueous solution of neutral detergent for pH 7 precision measuring instrument cleaning, manufactured by Wako Pure Chemical Industries, Ltd., made of nonionic surfactant, anionic surfactant and organic builder) with ion-exchanged water approximately 3 times by mass Add about 0.2 ml of the diluted solution. Further, about 0.02 g of a measurement sample is added, and dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC. As the ultrasonic disperser, a desktop type ultrasonic cleaner disperser (for example, “VS-150” (manufactured by VervoCrea)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Ion exchange water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.

For the measurement, the above-mentioned flow type particle image analyzer equipped with “UPlanApro” (magnification 10 times, numerical aperture 0.40) as an objective lens is used, and the particle sheath “PSE-900A” (manufactured by Sysmex Corporation) is used as the sheath liquid. It was used. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 3000 toner particles are measured in the HPF measurement mode and in the total count mode. Then, the binarization threshold at the time of particle analysis is set to 85%, the analysis particle diameter is limited to the circle equivalent diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles is obtained.
In measurement, automatic focus adjustment is performed using standard latex particles (for example, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) diluted with ion-exchanged water before starting the measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.
In the present invention, a flow type particle image measuring apparatus that has been calibrated by Sysmex Corporation and that has been issued a calibration certificate issued by Sysmex Corporation is used. Measurement is performed under the measurement and analysis conditions when the calibration certificate is received, except that the analysis particle diameter is limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm.

The measurement principle of the flow-type particle image measuring device “FPIA-3000” (manufactured by Sysmex Corporation) is to take a flowing particle as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle image is picked up by a CCD camera, and the picked-up image is image-processed at an image processing resolution of 512 × 512 pixels (0.37 × 0.37 μm per pixel), the contour of each particle image is extracted, and the particle image The projected area S, the peripheral length L, etc. are measured.
Next, the equivalent circle diameter and the circularity are obtained using the area S and the peripheral length L. The equivalent circle diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity is a value obtained by dividing the circumference of the circle obtained from the equivalent circle diameter by the circumference of the projected particle image. Defined and calculated by the following formula.
Circularity = 2 × (π × S) ^1/2 / L
When the particle image is circular, the circularity is 1.000. The greater the degree of irregularities on the outer periphery of the particle image, the smaller the circularity. After calculating the circularity of each particle, the range of the circularity of 0.200 to 1.000 is divided into 800, the arithmetic average value of the obtained circularity is calculated, and the value is defined as the average circularity.

<Measurement method of true specific gravity of toner, small particle size silica particles and large particle size silica particles>
The true specific gravity of the toner, the small particle size silica particles and the large particle size silica particles was measured with a dry automatic densimeter autopycnometer (manufactured by Yuasa Ionics). The conditions are as follows.
Cell: SM cell (10 ml)
Sample amount: about 2.0 g (toner), 0.05 g (small particle size silica particles and large particle size silica particles)
This measurement method measures the true specific gravity of a solid / liquid based on a gas phase substitution method. Similar to the liquid phase replacement method, it is based on Archimedes' principle, but uses a gas (argon gas) as a replacement medium, and therefore has high accuracy for micropores.

<Measurement of hydrophobicity of small particle size silica particles and large particle size silica particles>
1 g of the small particle size silica particles and large particle size silica particles were placed in a 200 mL separatory funnel, 100 mL of pure water was added thereto, the stopper was added, and the mixture was shaken with a tumbler mixer for 10 minutes. After shaking, let stand for 10 minutes, extract 20-30 mL of the lower layer from the funnel, dispense the lower layer mixture into a 10 mm quartz cell, apply pure water as a blank to a colorimeter, and light at a wavelength of 500 nm The transmittance (%) was defined as the hydrophobic rate.

<Measurement method of immobilization ratio of silicone oil based on carbon amount in small particle silica fine particles> (Extraction of free silicone oil)
(1) Put 0.50 g of small particle size silica fine particles and 40 ml of chloroform in a beaker and stir for 2 hours.
(2) Stop stirring and let stand for 12 hours.
(3) The sample is filtered and washed three times with 40 ml of chloroform.
(Measurement of carbon content)
The sample is burned at 1100 ° C. in an oxygen stream, and the amount of generated CO and CO ₂ is measured by IR absorbance to measure the amount of carbon in the sample. The carbon amount before and after extraction of the silicone oil is compared, and the immobilization rate based on the carbon amount of the silicone oil is calculated as follows.
(1) Place 0.40 g of sample in a cylindrical mold and press.
(2) 0.15 g of the pressed sample is precisely weighed, placed on a combustion board, and measured with Horiba EMA-110.
(3) [Carbon amount after silicone oil extraction] / [Carbon amount before silicone oil extraction] × 100 is defined as the immobilization rate based on the carbon amount of silicone oil.
When surface treatment with silicone oil is performed after hydrophobic treatment with silane compound, etc., the amount of carbon in the sample is measured after hydrophobic treatment with silane compound, etc., and carbon before and after extraction of silicone oil is measured after silicone oil treatment. By comparing the amounts, the immobilization rate based on the amount of carbon derived from silicone oil is calculated as follows.
(4) [Carbon amount after silicone oil extraction] / [(carbon amount before silicone oil extraction−carbon amount after hydrophobic treatment with silane compound)] × 100, To do.
On the other hand, when the hydrophobic treatment is performed with a silane compound or the like after the surface treatment with silicone oil, the immobilization rate based on the amount of carbon derived from silicone oil is calculated as follows.
(5) [(carbon amount after silicone oil extraction-carbon amount after hydrophobic treatment with silane compound)] / [carbon amount before silicone oil extraction] × 100, To do.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, all the parts and% of an Example and a comparative example are mass references | standards unless there is particular notice.

<Production example of magnetic body 1>
During an aqueous ferrous sulfate solution, 1.10 eq of sodium hydroxide solution from 1.00 relative to iron element, the amount of _P 2 _{O 5} to an iron element to be 0.15% by mass in terms of phosphorus, the iron element On the other hand, SiO ₂ in an amount of 0.50% by mass in terms of silicon element was mixed to prepare an aqueous solution containing ferrous hydroxide. The pH of the aqueous solution was 8.0, and an oxidation reaction was performed at 85 ° C. while blowing air to prepare a slurry liquid having seed crystals.
Subsequently, after adding ferrous sulfate aqueous solution so that it may become 0.90 to 1.20 equivalent with respect to the original alkali amount (sodium component of caustic soda) to this slurry liquid, the slurry liquid is maintained at pH 7.6, The oxidation reaction was promoted while blowing air to obtain a slurry liquid containing magnetic iron oxide. After filtration and washing, the water-containing slurry was once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample was put into another aqueous medium without drying, stirred and redispersed with a pin mill while circulating the slurry, and the pH of the redispersed liquid was adjusted to about 4.8. Then, 1.6 parts by mass of n-hexyltrimethoxysilane coupling agent with respect to 100 parts by mass of magnetic iron oxide (the amount of magnetic iron oxide was calculated by subtracting the water content from the water-containing sample) was added while stirring. Hydrolysis was performed. Thereafter, the mixture was sufficiently stirred, and the dispersion was subjected to surface treatment at a pH of 8.6. The produced hydrophobic magnetic material is filtered with a filter press, washed with a large amount of water, dried at 100 ° C. for 15 minutes, and then at 90 ° C. for 30 minutes. 0.21 μm magnetic body 1 was obtained.

<Example of production of polyester resin 1>
The following components were placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and reacted for 10 hours while distilling off the water produced at 230 ° C. under a nitrogen stream.
-Bisphenol A propylene oxide 2 mol adduct 75 parts by mass-Bisphenol A propylene oxide 3 mol adduct 25 parts by mass-100 parts by mass terephthalic acid-0.25 parts by mass titanium catalyst (titanium dihydroxybis (triethanolamate))
Next, the reaction was carried out under reduced pressure of 5 to 20 mmHg, and when the acid value became 2 mgKOH / g or less, it was cooled to 180 ° C., 10 parts by weight of trimellitic anhydride was added, taken out after reaction for 2 hours under normal pressure sealing, After cooling to 0, pulverization gave polyester resin 1. The obtained polyester resin 1 had a main peak molecular weight (Mp) of 10,500 as measured by gel permeation chromatography (GPC).

<Production Example of Toner Particle 1>
After 450 parts by mass of 0.1 M Na ₃ PO ₄ aqueous solution was added to 720 parts by mass of ion-exchanged water and heated to 60 ° C., 67.7 parts by mass of 1.0 M CaCl ₂ aqueous solution was added to stabilize the dispersion. An aqueous medium containing the agent was obtained.
-Styrene 78.0 parts by mass-n-butyl acrylate 22.0 parts by mass-Divinylbenzene 0.6 parts by mass-Iron complex of monoazo dye (T-77: Hodogaya Chemical Co., Ltd.) 3.0 parts by mass Magnetic body 1 90.0 parts by mass / Polyester resin 1 5.0 parts by mass The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.) to obtain a polymerizable monomer composition. . The obtained polymerizable monomer composition was heated to 60 ° C., 15.0 parts by mass of Fischer-Tropsch wax (melting point: 74 ° C., number average molecular weight Mn: 500) was added and mixed, and after dissolution, the polymerization initiator was added. As a result, 7.0 parts by mass of dilauroyl peroxide was dissolved to obtain a toner composition.
The toner composition was put into the aqueous medium, and granulated by stirring at 12,000 rpm for 10 minutes with a TK homomixer (Special Machine Industries Co., Ltd.) in an N ₂ atmosphere at 60 ° C. Thereafter, the mixture was reacted at 74 ° C. for 6 hours while stirring with a paddle stirring blade.
After completion of the reaction, the suspension was cooled, washed with hydrochloric acid, filtered and dried to obtain toner particles 1. The physical properties of the obtained toner particles 1 are shown in Table 1.

<Production Example of Toner Particle 2>
71.0 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 28.0 parts by mass of terephthalic acid, 1.0 part by mass of trimellitic anhydride, and 0. 5 parts by mass were placed in a 4-liter 4-neck flask made of glass, and a thermometer, a stirring rod, a condenser and a nitrogen introduction tube were attached and placed in a mantle heater. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the mixture was reacted at a temperature of 200 ° C. for 4 hours to obtain a polyester resin 1-1. The polyester resin 1-1 had a weight average molecular weight (Mw) of 80000, a number average molecular weight (Mn) of 3500, and a peak molecular weight (Mp) of 5700.
Moreover, 70.0 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 20.0 parts by mass of terephthalic acid, 3.0 parts by mass of isophthalic acid, trimellitic anhydride 7 0.0 part by mass and 0.5 part by mass of titanium tetrabutoxide were placed in a 4-liter 4-neck flask made of glass, and a thermometer, a stir bar, a condenser and a nitrogen inlet tube were attached and placed in a mantle heater. Next, after replacing the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and the mixture was reacted at 220 ° C. for 6 hours to obtain polyester resin 1-2. This polyester resin 1-2 was the weight average molecular weight (Mw) 120,000, the number average molecular weight (Mn) 4000, and the peak molecular weight (Mp) 7800.
The polyester resin 1-1: 50 parts by mass and the polyester resin 1-2: 50 parts by mass are premixed with a Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd.), and a melt kneader (PCM-30 type, Ikegai Iron Works Co., Ltd.). The binder resin 1 was obtained by melt blending under the conditions of a rotation speed of 3.3 s ⁻¹ and a kneading resin temperature of 100 ° C.

Next: Styrene 64.0 parts by mass n-butyl acrylate 13.5 parts by mass Acrylonitrile 2.5 parts by mass The above was charged in an autoclave, and the system was replaced with N ₂ and maintained at 180 ° C. while stirring at elevated temperature. . 50 parts by mass of a 2% by mass t-butyl hydroperoxide xylene solution was continuously dropped into the system for 5 hours, and after cooling, the solvent was separated and removed to obtain a polymer A. When the molecular weight of the polymer A was measured, the weight average molecular weight (Mw) was 7000 and the number average molecular weight (Mn) was 3000.
-Binder resin 1 100 parts by mass-Polymer A 2 parts by mass-Fischer-Tropsch wax 4 parts by mass (maximum endothermic peak temperature 105 ° C)
-Magnetic material 1 95 parts by mass-Monoazo iron compound 2 parts by mass (T-77, Hodogaya Chemical Co., Ltd.)
After mixing the above prescription with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), a biaxial kneader (PCM-30 type, manufactured by Ikekai Tekko Co., Ltd.) set at a temperature of 130 ° C. Kneaded. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material. The obtained coarsely crushed material was pulverized with a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). Furthermore, classification was performed by a multi-division classifier using the Coanda effect to obtain resin particles. The obtained resin particles had a weight average particle diameter (D4) of 6.3 μm.
The resin particles were subjected to a thermal spheronization treatment. The thermal spheronization treatment was performed using a surfing system (manufactured by Nippon Pneumatic Co., Ltd.). The operating conditions of the thermal spheronizer are: feed amount = 5 kg / hr, hot air temperature C = 250 ° C., hot air flow rate = 6 m ³ / min, cold air temperature E = 5 ° C., cold air flow rate = 4 m ³ / min, cold air absolute moisture content = 3 g / m ³ , blower air flow = 20 m ³ / min, injection air flow rate = 1 m ³ / min, diffusion air = 0.3 m ³ / min.
Toner particles 2 were obtained by surface treatment under the above conditions. The physical properties of the obtained toner particles 2 are shown in Table 1.

<Production Example of Toner 1 for Example>
The toner particles 1 obtained in the production example of the toner particles 1 were subjected to an external addition mixing process using the apparatus shown in FIG.
In the present embodiment, the apparatus shown in FIG. 2 is used, in which the diameter of the inner peripheral portion of the main casing 1 is 130 mm and the volume of the processing space 9 is 2.0 × 10 ⁻³ m ^3. The rated power was 5.5 kW, and the shape of the stirring member 3 was that of FIG. The overlapping width d of the stirring member 3a and the stirring member 3b in FIG. 3 is 0.25D with respect to the maximum width D of the stirring member 3, and the clearance between the stirring member 3 and the inner periphery of the main casing 1 is 3.0 mm. .
In the apparatus configuration described above, 100 parts by mass of toner particles 1 and small particle size silica fine particles 1 shown in Table 2 (the treatment agent used for the primary treatment during the hydrophobization treatment is dimethylpolysiloxane having a kinematic viscosity of 50 cSt at 25 ° C. Yes, the treatment agent used in the secondary treatment is hexamethyldisilazane, fixing rate of silicone oil based on carbon amount: 98%, number average particle size of primary particles of silica fine particles after hydrophobic treatment: 8 nm, hydrophobicity: 98%, and 0.50 parts by mass of large particle size silica fine particles 1 shown in Table 2 (number average particle size of primary particles: 60 nm, hydrophobicity: 98%, hydrophobization treatment: hexamethyldisilazane) 0.30 part by weight was put into the apparatus shown in FIG.

After the toner particles 1, small particle size silica particles 1 and large particle size silica particles 1 were added, premixing was performed in order to uniformly mix the toner particles, small particle size silica particles and large particle size silica particles. The premixing conditions were such that the power of the drive unit 8 was 0.10 W / g (the rotational speed of the drive unit 8 was 150 rpm) and the processing time was 1 minute.
After the pre-mixing, an external additive mixing process was performed. The external mixing process conditions are such that the outermost end peripheral speed of the stirring member 3 is adjusted so that the power of the drive unit 8 is constant at 0.60 W / g (the rotational speed of the drive unit 8 is 1400 rpm), and the processing time For 5 minutes. Table 3 shows the external additive mixing conditions.
After the external addition and mixing treatment, coarse particles and the like were removed with a circular vibration sieve equipped with a screen having a diameter of 500 mm and an opening of 75 μm, to obtain Example Toner 1. Table 3 shows the external addition conditions and physical properties of Example Toner 1.

<Examples of Production of Toners 2 to 42 for Examples and Toners 1 to 20 for Comparative Examples>
In the production example of the toner 1 for Example, the types of the small particle size silica particles and the large particle size silica particles (treatment agent, particle size, hydrophobicity, oil immobilization rate) shown in Table 2, Table 3 or Table 4 and Exemplified toners 2 to 42 and comparative toners 1 to 20 were produced in the same manner except that the number of added parts, toner particles, external addition apparatus, external addition conditions, and the like were changed. The kinematic viscosities listed in Table 2 are the results measured at 25 ° C. Table 3 or Table 4 shows the external addition conditions and physical properties of the obtained toners 2 to 42 for Examples and toners 1 to 22 for comparative examples.
Here, when using a Henschel mixer as an external device, Henschel mixer FM10C (Mitsui Miike Chemical Co., Ltd.) was used. In some production examples, the pre-mixing step was not performed.
FIG. 5 shows a plot of total coverage X1 and diffusion index of toners 1 to 42 for the examples and toners 1 to 20 for the comparative examples.

表中の疎水率とは、上記記載の疎水率の測定によって得られる疎水率である。また、一次処理とはシリカ原体に対して最初に行う疎水化処理であり、二次処理とは一次処理が終えた後に行う２段目の疎水化処理である。

The hydrophobicity in the table is the hydrophobicity obtained by measuring the hydrophobicity as described above. The primary treatment is a hydrophobization treatment that is initially performed on the silica base material, and the secondary treatment is a second-stage hydrophobization treatment that is performed after the primary treatment is completed.

<Example 1>
As the image forming apparatus, an LBP 3100 modified from 16 sheets / minute to 24 sheets / minute was used. The cartridge was equipped with a small-sized developing sleeve having a diameter of 10 mm and a charging roller having a diameter of 8 mm, and the container volume was doubled to double the toner filling amount.

[Evaluation of durability]
Using this modified machine, toner 1 for the example was used, and in a high temperature and high humidity environment (32.5 ° C / 80% RH), a horizontal line with a printing rate of 0.5% was printed in an intermittent mode with 2400 sheets per day. The image was drawn out and tested for 12,000 sheets in 5 days. By evaluating under such conditions, a large amount of stress is received on the toner, so that the durability performance can be evaluated under more severe conditions.
As a result, it was possible to obtain a uniform image having a high density before and after the endurance use test and having no fog on the non-image area.
The evaluation methods for each evaluation performed in the examples and comparative examples of the present invention and the judgment criteria thereof will be described below.

<Evaluation of white spots>
After the 12,000-sheet image printing test described above, the charging roller is newly replaced, and then a non-image vertical band (100 mm from the right end) and a solid image vertical band (100 mm from the left end) are arranged in the transfer paper transport direction. Ten charts A are output in the continuous mode, and immediately after that, one full-color image is output. Next, the density of the output solid image is measured with a Magbeth reflection densitometer (manufactured by Macbeth). The measurement positions at this time are randomly measured at 10 points in the image area where the non-image position (right end 100 mm) and the solid image position (left end 100 mm) are output on Chart A. The toner with the more noticeable white spots is more likely to have white spots in the toner at the non-image position in Chart A, and the density difference between the no-image position (right end 100 mm) and the solid image position (left end 100 mm) increases. The following ranking was performed for the concentration difference obtained from the measurement.
(Evaluation criteria)
A: Very good (less than 0.05)
B: Good (0.05 or more and less than 0.10)
C: Acceptable level in the present invention (from 0.10 to less than 0.20)
D: Impossible level in the present invention (0.20 or more)
In this evaluation, what is considered to be a level having no practical problem is an image density difference of rank C or higher.

<Image density>
After the 12,000-sheet endurance test, the charging roller was newly replaced, and then a solid image portion was output. The average value was obtained. The criteria for evaluating the reflection density of a solid image at 12,000 sheets are as follows.
A: Very good (above 1.40)
B: Good (from 1.30 to less than 1.40)
C: Normal (1.20 or more and less than 1.30)
D: Inferior (less than 1.20)
In this evaluation, what is considered to be a level having no practical problem is an image density of rank C or higher.

<Evaluation of charging roller contamination>
The charging roller contamination was evaluated based on the following evaluation criteria by visually observing the roller surface and the halftone image every 2000 sheets during a durability use test of 12000 sheets.

A: Defects are not recognized at all on the roller surface and the image.
B: After the 10,000th sheet, the roller surface is slightly stained but does not appear in the image. C: Dirt is slightly observed on the roller surface after the 8000th sheet, and some density unevenness is also generated in the image after the 10000th sheet.
D: Contamination is observed on the roller surface after the 8000th sheet, and the image density unevenness starts to be noticeable E: Contamination on the roller surface is recognized after the 6000th sheet, and it is confirmed that the uneven density is clearly formed in the image it can.
It should be noted that in this evaluation, an image having a rank of C or higher is considered to be a practically acceptable level.

<Examples 2 to 42>
In Example 1, the same evaluation was performed using the toners 2 to 42 for Example.
As a result, it was possible to obtain images having no practical problems in all the evaluated items. The evaluation results are shown in Table 5.

<Comparative Examples 1 to 20>
In Example 1, the same evaluation was performed using the toners 1 to 20 for comparative examples. As a result, in all of the toners, the level of image blanking is not preferable for practical use, or image defects due to charging roller contamination have occurred. The evaluation results are shown in Table 6.

  1: main body casing, 2: rotating body, 3, 3a, 3b: stirring member, 4: jacket, 5: raw material inlet, 6: product outlet, 7: central shaft, 8: drive unit, 9: processing space, 10: Rotating body end side surface, 11: Rotating direction, 12: Return direction, 13: Feeding direction, 16: Inner piece for raw material inlet, 17: Inner piece for product outlet, d: Overlapping portion of stirring member Interval, D: Width of stirring member, 100: Electrostatic latent image carrier (photoconductor), 102: Toner carrier, 103: Development blade, 114: Transfer member (transfer charging roller), 116: Cleaner container, 117: Charging member (charging roller), 121: laser generator (latent image forming means, exposure device), 123: laser, 124: pickup roller, 125: transport belt, 126: fixing device, 140: developing device, 14 : Stirring member

Claims (8)

A toner particle containing a binder resin and a colorant, and a toner having small particle size inorganic particles and large particle size inorganic particles present on the surface of the toner particles,

The small particle size inorganic fine particles are small particle size silica fine particles having a primary particle number average particle size (D1) of 5 nm or more and 20 nm or less, and the large particle size inorganic fine particles are primary particle number average particle size (D1). ) Is a large particle size silica fine particle of 25 nm or more and 100 nm or less,

The content of the small particle size silica fine particles per 100 parts by mass of the toner particles is M parts by mass,
When the content of the large particle size silica fine particles per 100 parts by mass of toner particles is N parts by mass,

M and N satisfy the following formula 1 and formula 2,
(Formula 1) 0.6 ≦ M + N ≦ 1.5
(Formula 2) 0.2 ≦ N / M ≦ 1.3

The total coverage X1 by the small particle size silica particles and the large particle size silica particles on the toner surface determined by an X-ray photoelectron spectrometer (ESCA) is 40.0 area% or more and 75.0 area% or less. A toner characterized in that a diffusion index represented by the following formula 3 satisfies the following formula 4 when the total theoretical coverage by the small particle size silica fine particles and the large particle size silica fine particles is X2.


(Formula 3) Diffusion index = X1 / X2
(Expression 4) Diffusion index ≧ −0.0042 × X1 + 0.62
  2. The toner according to claim 1, wherein the small particle size inorganic fine particles are small particle size silica fine particles having a primary particle number average particle size (D1) of 5 nm or more and 15 nm or less.   3. The toner according to claim 1, wherein the large-sized inorganic fine particles are large-sized silica fine particles having a number average particle diameter (D1) of primary particles of 25 nm or more and 80 nm or less.   The toner according to claim 1, wherein the toner particles have an average circularity of 0.960 or more.   The toner according to claim 1, wherein the small particle size silica fine particles have a hydrophobicity of 70% or more.   The toner according to any one of claims 1 to 5, wherein the small particle size silica fine particles are treated with silicone oil and then treated with at least one of alkoxysilane and silazane.   The toner according to claim 6, wherein the silica fine particles having a small particle diameter are treated with silicone oil, and the carbon oil-based immobilization ratio of the silicone oil is 70% by mass or more. The toner according to claim 1, wherein the toner particles are produced by a suspension polymerization method.

Images