JP6896545B2 - toner - Google Patents

Description

The present invention relates to toners used in image forming methods for visualizing electrophotographic and electrostatic charge images.

In recent years, the usage of copiers and printers has changed from one by one to one by one, so it is required to achieve long life, high image quality, and further miniaturization. In addition, the areas where printers are used are becoming more diverse than before, and they must be able to be used without problems in any usage environment.
For miniaturization, it is effective to miniaturize the process cartridge that houses the developer and the fuser mounted on the main body. One of the effective means for miniaturizing the process cartridge is, for example, the adoption of a cleanerless system. Since the cleanerless system does not have a cleaning blade or a waste toner box, it can greatly contribute to the miniaturization of the main body.
In the cleanerless system, the transfer residual toner passes through the charging process, is collected in the toner container, and is sent to the developing process again. Therefore, as compared with a system having a cleaning blade, the mileage of one toner particle is longer, so that the stress applied to the toner is larger. Therefore, in long-term use, the toner particles are brittlely broken and cracked due to the accumulation of stress in the toner. In addition, the hardness of the toner particles may be deformed by losing the load from the member and crushed, and may remain in the cartridge as irregularly shaped particles. It is difficult for such irregularly shaped particles to be uniformly charged by rubbing or the like, and they may become a “fog” component that is developed in a non-image region on the electrostatic latent image carrier.
Further, when the transfer residual toner is sent to the charging member, the charging member may be contaminated by the toner or the external additive coating on the toner matrix particles. As a result, it becomes difficult for the electrostatic latent image carrier to maintain the desired charging performance over a long period of use, and image loss may occur.
As described above, in order to solve the problems caused by the miniaturization of the main body, it is necessary to suppress the fog by reducing the deformed particles and to suppress the contamination of the charged member by the liberated external additive or the like.
Various toner improvement methods have been proposed to solve these problems.
Patent Document 1 proposes a method for producing toner matrix particles having a high circularity in order to make the charge amount distribution uniform in addition to a sharp particle size distribution. This method includes a step of forming droplets of the polymerizable monomer composition and a step of polymerizing the polymerizable monomer composition to obtain toner mother particles, and a dispersion stabilizer is used in both steps. Use an aqueous medium containing. By using an aqueous medium containing a dispersion stabilizer also in the polymerization step, toner mother particles having a high circularity are obtained.
Further, Patent Document 2 proposes that inorganic fine particles are internally added in advance and unevenly distributed on the surface to impart appropriate unevenness to the surface of the mother body and improve transferability and cleanability.
In Patent Document 3, in the toner mother particles containing the binder resin containing the amorphous resin (A) and the amorphous polyester resin (B) and the colorant, the matrix phase containing the amorphous resin (A) is used. Describes a toner in which the amorphous polyester resin (B) is dispersed as a domain phase. In the observation image of the cross section of the toner mother particles, it is described that the number average domain diameter has a size in a specific range.
In Patent Document 4, two or more kinds of resin particles are used and heat-aggregated by utilizing the difference in glass transition temperature of each resin to obtain toner mother particles having irregularities derived from the resin particles formed on the surface of the toner mother particles. ing.

Japanese Patent No. 3972709 Japanese Unexamined Patent Publication No. 2006-184746 JP-A-2015-152703 Japanese Patent No. 4485382

However, in Patent Document 1, when an aqueous medium containing a dispersion stabilizer is used in the polymerization step, toner mother particles having a high circularity are certainly obtained, irregularly shaped particles are reduced, and the chargeability of one toner particle is uniform. There is a possibility that post-black fog will improve. However, since the surface of the toner mother particles is smooth, it may work disadvantageously for the adhesion of a large particle size external additive such as spacer particles, and as a result, it may not be possible to suppress contamination of the charged member.
Further, in Patent Document 2, a large number of irregularly shaped particles may be present due to the toner mother particle manufacturing method that involves volume shrinkage during solvent removal, and considering the application of a cleanerless system, toner cracking may easily occur. There is sex. In addition, it may not be possible to impart a desired uneven shape, and it may be difficult to suppress contamination of charged members and fog.
Regarding Patent Document 3, when the cleanerless system is adopted, the amount of charge may decrease in the latter half of the durability, probably because the external additive is embedded in the polyester portion deposited on the surface layer. In addition, the toner may be cracked or crushed, and fog cannot be suppressed in some cases.
Further, in Patent Document 4, since the toner constituent materials having different glass transition temperatures are heat-aggregated to give the surface of the toner matrix particles an uneven shape, it may not be possible to impart a desired uneven size. In addition, it may be difficult to reduce irregularly shaped particles due to the toner matrix particle manufacturing method that utilizes heat aggregation, and considering application to a one-component contact development cleanerless, toner cracking is likely to occur or uniform charging becomes difficult. there is a possibility.
From the above, assuming the miniaturization of the main body in the future, there is still room for improvement in order to suppress fog and contamination of charged members by reducing deformed particles.
An object of the present invention is to provide a toner that solves the above problems.
That is, an object of the present invention is to provide a toner capable of having good fog characteristics and reducing contamination of charged members over a long period of use in any usage environment.

The present invention is a toner having toner matrix particles containing a binder resin, an amorphous polyester and a colorant.
The binding resin contains a vinyl resin and
The toner has an average circularity of 0.960 or more and has an average circularity of 0.960 or more.
In the cross section of the toner observed with a transmission electron microscope, the vinyl resin forms a matrix, the amorphous polyester forms a domain, and the domain of the amorphous polyester is formed from the outline of the cross section. Within 75% of the distance between the contour and the center point of the cross section, 96 area% or more is present based on the total area of the domain.
The average of the scanning electron microscope (SEM) binarization is that the white area percentage obtained by from the toner mother particles observed under the following conditions in is not more than 10.0%,
The toner base particles of number-based particle size distribution and the true density obtained from the theoretical specific surface area A (m ² / g), and the specific surface area B, as measured by the BET method (m ² / g), the following equation ( Satisfy 1) and (2) ,
0.450 ≤ B ≤ 1.500 ... (1)
1.23 ≤ B / A ≤ 1.60 ... (2)
It relates to a toner characterized by that.
・ Conditions for calculating the white area ratio [Shooting conditions]
Scanning electron microscope: S-4800
Shooting magnification: 2000 times Shooting image: SE image Acceleration voltage: 2.0 kV
Acceleration current: 10.0 μA
Probe current: Normal
Focus mode: UHR
WD: 5.0 mm
[Area ratio measurement conditions]
Image processing software: Using imageJ, the background of the captured image is completely blackened and then binarized, and the white area ratio in 50% square of the particle size is calculated centering on the center of gravity of the toner.

According to the present invention, it is possible to obtain a toner capable of having good fog characteristics and reducing contamination of charged members over a long period of use in any usage environment.

It is a figure which shows an example of a developing apparatus. It is a figure which shows an example of an image forming apparatus. This is an example of a developing device in which a magnet is arranged inside a toner carrier. This is an example of a method for calculating the white area ratio. It is a graph which showed the transmittance with respect to the methanol concentration.

As described above, the miniaturization required for printers in recent years includes, for example, a cleanerless system, removal of a fixing bias mechanism, and the like.

Considering a cleanerless system, since the transfer residual toner is reused, the number of times of rubbing between the toner carrier and the regulation blade increases, and toner deterioration is promoted. That is, the toner mother particles are cracked or crushed, the particle size distribution is widened, and it becomes difficult to uniformly charge the toner carrier and the blade by rubbing.

The cracking of the toner mother particles is likely to occur in the presence of irregular particles such as individual particles and spindle-shaped particles. The reason is as follows.

First of all, there are two particles one by one, but since the resin part that connects the two particles is thin, I think that it will easily break due to external stress. Further, it is presumed that the deformed toner such as the spindle-shaped toner has poor rolling property, so that the load due to external stress is locally generated.

On the other hand, the crushing of the toner particles occurs remarkably when the hardness of the toner mother particles is low.

In addition, due to such cracking and crushing of toner, fog is a phenomenon in which toner having a low charge amount is developed in a non-image region (white image portion) on an electrostatic latent image carrier after solid black image paper is passed. (Fog after black) is more likely to occur. This fog phenomenon occurs remarkably in a low temperature and low humidity environment. It is considered that this is because the hardness of the members such as the charging roller, the toner carrier, and the regulation blade becomes high, so that the toner passing between them is greatly stressed.

Therefore, in order to suppress the cracking and crushing of the toner, it is necessary to reduce the deformed particles of the toner and increase the hardness. By doing so, it is possible to obtain a toner in which post-blackening fog is suppressed in a low temperature and low humidity environment.

Conventionally, a suspension polymerization method is mentioned as a method of suppressing irregularly shaped particles while increasing the toner hardness, that is, a method of obtaining a toner having a high circularity.

The suspension polymerization toner mainly has a structure in which the shell portion has a high softening point material and the core portion has a low softening point material or a plasticizer such as a release agent. However, when used for a long time in an image forming device that easily gives stress to toner, such as a cleanerless system, even if the shell has a high softening point material, the core part is soft, and the toner is crushed. It was difficult to improve the deterioration of toner.

On the other hand, by obtaining a toner having a high circularity by the suspension polymerization method, cracking of the toner is suppressed and it is also effective for uniform charging. However, in consideration of the extension of life in recent years, a large particle size external particle is often used as spacer particles. However, when a large particle size external particle is used for such a highly circular toner, the surface of the toner mother particle is exposed. Due to its smoothness, adhesion may be inadequate. As a result, it may not be possible to maintain the initial charging performance of the toner. Further, when a cleanerless system is adopted for miniaturization, contamination of the charging member with an external additive may become more remarkable. When the charged member is contaminated by the external additive, the charging performance is deteriorated at the contaminated portion of the charged member, and image defects, for example, image density unevenness may occur.

When the contact charging mechanism is used, this contamination of the charged member is considered to be more remarkable in a high temperature and high humidity environment in which the charging roller is soft and contaminants are likely to adhere to it.

As described above, when considering the application of the one-component contact development cleanerless system, it is currently difficult to increase the hardness of the toner, reduce irregular particles, and at the same time suppress contamination of charged members by external additives. It was.

As a result of detailed studies by the present inventors, it has been found that the following items must be satisfied in order to solve the above problems.

That is, it is a toner having toner matrix particles containing a binder resin, an amorphous polyester and a colorant, and the binder resin contains a vinyl resin.
The toner has an average circularity of 0.960 or more and has an average circularity of 0.960 or more.
The average white area ratio obtained by binarizing the toner matrix particles observed with a scanning electron microscope (SEM) under the following conditions is 10% or less.
The particle size distribution based on the number of toner mother particles, the theoretical specific surface area A obtained from the true density, and
The toner is characterized in that the specific surface area B measured by the BET method satisfies the following formulas (1) and (2).
0.450 ≤ B ≤ 1.500 ... (1)
1.23 ≤ B / A ≤ 1.60 ... (2)
How to find the white area ratio [Shooting conditions]
Scanning electron microscope: S-4800
Shooting magnification: 2000 times Shooting image: SE image Acceleration voltage: 2.0 kV
Acceleration current: 10.0 μA
Probe current: Normal
Focus mode: UHR
WD: 5.0 mm
[Area ratio measurement conditions]
Image processing software: Using imageJ, the background of the captured image is completely blackened and then binarized, and the white area ratio in 50% square of the particle size is calculated centering on the center of gravity of the toner.

Hereinafter, the present invention will be described in detail.

First, the toner of the present invention is a toner having toner matrix particles containing a binder resin, an amorphous polyester and a colorant, and the binder resin contains a vinyl resin.

By having the vinyl resin, for example, it is easy to maintain the rigidity and viscosity of the toner, and cracking and crushing of the toner can be suppressed. By having the amorphous polyester, toner particles having few irregularly shaped particles can be obtained. For example, when toner particles are produced by the suspension polymerization method, the reason is not clear, but the presence of the polyester resin improves the dispersibility of the colorant in the polymerizable monomer composition in the granulation step and the polymerization step. However, it is considered that the particles of the polymerizable monomer composition are stabilized in the aqueous medium. As a result, coalescence of particles is suppressed, and it is considered that toner particles having few irregularly shaped particles can be obtained.

Further, the shape of the toner surface can be controlled by the abundance ratio of the vinyl resin and the amorphous polyester in the toner, and the suppression of fog can be further improved.

Further, it is important that the toner of the present invention has an average circularity of 0.960 or more and 1.000 or less in order to suppress cracking and crushing of the toner matrix particles and to control the ultrafine surface shape of the toner.

When the average circularity of the toner is 0.960 or more, the shape of the toner becomes spherical or close to it, and it is easy to obtain uniform triboelectricity with excellent fluidity, and fog and electrostatic offset can be suppressed. .. Further, in the circularity distribution of the toner, when the mode circularity is 0.98 or more, the above effect becomes more remarkable, which is very preferable.

If it is less than 0.960, it becomes difficult to achieve both the white area ratio and the surface unevenness index, and it is not possible to achieve both suppression of fog and electrostatic offset and suppression of contamination of charged members.

The white area ratio is a numerical value of the particle surface shape when the toner is viewed macroscopically. As a result of the examination by the present inventors, if the white area ratio is high, that is, if the surface of the toner matrix particles has irregularities that can be easily observed by SEM (about submicrons), the latter half of the durability in a low temperature and low humidity environment It turned out that the fog in the area worsened. The reason is not clear, but I think as follows.

For example, considering the formation of toner matrix particles by the suspension polymerization method, the polymerizable monomer composition that finally becomes the toner matrix particles repeats coalescence, shearing, and coalescence in the granulation step. In these two phenomena, when shearing is more likely to occur than coalescence, fine particles are more likely to be generated. When the fine particles are generated, the dispersant for stably presenting the polymerizable monomer composition as oil droplets in the aqueous medium is deprived of the fine particles. As a result, there is not enough dispersant to stabilize the oil droplets having a toner particle size, and irregularities of about submicron are formed on the toner matrix particles. As described above, the toner mother particles thus produced do not have enough dispersant to stabilize the oil droplets having a toner particle size, so that it is easy to obtain irregularly shaped particles such as two particles or spindle-shaped particles. Therefore, as a result, when considering long-term use, the toner is liable to crack, the fluidity deteriorates, the uniform chargeability deteriorates, the saturated charge amount decreases, and fog deteriorates.

As a result of further studies by the present inventors, it was found that when the white area ratio exceeds 10.0%, post-black fog and electrostatic offset in the latter half of durability under a low temperature and low humidity environment worsen.

In order to reduce the white area ratio to 10.0% or less, it is preferable to control the acid value and the hydroxyl value of the amorphous polyester resin. Further, it is preferable to have a step of mixing the particles of the polymerizable monomer composition obtained in the granulation step with the second aqueous medium, and the second aqueous medium contains a dispersion stabilizer. By containing the dispersion stabilizer in the second aqueous medium, it is possible to supplement the dispersion stabilizer deficient at the time of granulation and further reduce the white area ratio. Further, it is more preferable that sodium chloride is contained in the first aqueous medium in the granulation step based on the polymerizable monomer composition. By containing a large amount of sodium chloride in the aqueous medium, it is possible to prevent the monomer of the polymerizable monomer from being dissolved in the particles of the polymerizable monomer composition due to the salting out effect. As a result, it is easy to suppress the generation of emulsified particles, and it becomes difficult for irregular particles such as two particles to be generated. The white area ratio is preferably 9.0% or less, and more preferably 7.0% or less.

^{Further, the toner of the present invention has a theoretical specific surface area A (m 2} / g) obtained from the particle size distribution and true density based on the number of toner matrix particles, and a specific surface area B (m ² / g) measured by the BET method. The toner is characterized by satisfying the following formulas (1) and (2).
0.450 ≤ B ≤ 1.500 ... (1)
1.23 ≤ B / A ≤ 1.60 ... (2)

Since this B / A (hereinafter referred to as the surface unevenness index) is a value calculated from the BET specific surface area measured by the BET multipoint method, it is a numerical value of a nanometer-order ultrafine unevenness shape. is there. Therefore, unevenness that is not reflected in the white area ratio described above is also included. The theoretical specific surface area A is a numerical value when all the particles are true spheres. Therefore, the larger the B / A is from 1.00, the more unevenness is formed on the particle surface. As a result of studies by the present inventors, it has been found that by imparting these ultrafine irregularities to the surface of the toner matrix particles, a good halftone image can be obtained through durability in a high temperature and high humidity environment. The reason for this is not clear, but I think it is as follows.

In the case of cleanerless, the external additive remaining on the electrostatic latent image carrier after toner transfer passes through the charging member and the toner carrier. At this time, most of the external additive contaminates the charging member, but when the toner is provided with an uneven shape of the same size as the external additive, the external additive can be scraped off by the convex portion. I believe. As a result, it is considered that a good halftone image with no uneven density is obtained.

Further, it was found that when the white area ratio is 10.0% or less and the above formulas (1) and (2) are satisfied, post-white fog is improved in a high temperature and high humidity environment. The reason is not clear, but it is speculated as follows.

First, after white fog, fog (white after fog) is a phenomenon in which toner with a low charge is developed in the non-image region (white image portion) on the electrostatic latent image carrier after solid white image paper is passed. Is. This phenomenon is caused by the electric charge stored in the toner leaking to the electrostatic latent image carrier side at the contact portion between the electrostatic latent image carrier and the toner carrier in the one-component contact developing method. I think there is.

At this time, if the surface of the toner mother particle is not provided with an uneven shape of about submicron and is provided with a nano-order uneven shape, the electrostatic latent shape is sufficiently provided to secure the amount of charge. The contact area with the image carrier can be reduced. As a synergistic effect, we believe that we are able to achieve both a high saturation charge amount and leak resistance. As a result, it is considered that the fog after white was improved.

If the surface unevenness index is less than 1.23, it is difficult to maintain the charging performance of the charging member throughout the durability, probably because the unevenness sufficient to scrape off the external additive is not formed. As a result, density unevenness occurs in the halftone image, and the contact area between the electrostatic latent image carrier and the toner carrier increases, resulting in worsening post-white fog. On the other hand, when the surface unevenness index exceeds 1.60, the fluidity of the toner deteriorates, the uniform chargeability deteriorates, and the post-black fog deteriorates in a low temperature and low humidity environment.

In order to set the surface unevenness index within the above range, it is preferable to control the interfacial tension of the amorphous polyester resin with oil droplets in the aqueous medium and to contain the hydrophobized magnetic fine particles as a colorant. .. A more preferable range of the surface unevenness index is 1.23 or more and 1.45 or less, and by controlling this range, it is extremely easy to achieve both improvement of fog in a low temperature and low humidity environment and improvement of fog in a high temperature and high humidity environment.

As described above, by satisfying these characteristics, it is possible to obtain a toner having good fog characteristics and suppressing contamination of charged members over a long period of use in any usage environment.

Further, from the viewpoint of ease of suppressing cracking of the toner, the aspect ratio of the toner is more preferably 0.910 or more. A high aspect ratio means that there are few irregularly shaped particles and the toner mother particles are closer to a sphere. When it is 0.910 or more, the cracking of the toner is dramatically suppressed through the durability, and the fog after black is improved.

Further, when the softening point of the toner is 115 ° C. or higher and 140 ° C. or lower, it is easy to achieve both fixability and suppression of toner crushing, which is preferable.

Next, the binder resin used in the present invention will be described.

The binder resin of the toner contains a vinyl resin. In addition to the vinyl resin, a known resin used as a binder resin may be used to the extent that the effect of the present invention is not impaired. The binder resin is preferably a vinyl resin.

As mentioned above, the vinyl resin can easily achieve the maintenance of rigidity and viscosity, and the amorphous polyester can easily introduce a specific structure for controlling the interfacial tension. Therefore, in order to suppress cracking and crushing of the toner and to suppress contamination of the charged member, it is preferable to use a toner configuration that effectively utilizes each feature. In other words, from the viewpoint of easily suppressing the cracking and crushing of the toner, it is more preferable that the amorphous polyester is unevenly distributed on the outside of the toner and a hard vinyl resin is present in the core portion.

Examples of the vinyl resin include the following.

Monopolymers of styrene such as polystyrene and polyvinyltoluene and their substitutes;
Styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, Styrene-octyl acrylate copolymer, dimethylaminoethyl styrene-acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-methacryl Dimethylaminoethyl acid acid copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene -Styrene-based copolymers such as maleic acid copolymer and styrene-maleic acid ester copolymer;
Polymethylmethacrylate, polybutylmethacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic acid resin and the like can be used. These can be used alone or in combination of two or more. Among these, a styrene-based copolymer and further a styrene-butyl acrylate copolymer are particularly preferable from the viewpoint of easy control of development characteristics and fixability.

It has an amorphous polyester together with a binder resin, and the interfacial tension of the amorphous polyester dissolved in styrene / butyl acrylate = 80/20 (mass ratio) in a pH 6.0 tricalcium phosphate aqueous solution is 25 mN /. It is preferably m or more and 38 mN / m or less from the viewpoint of controlling the extremely fine uneven shape on the surface of the toner matrix particles.

As described above, for example, considering the formation of toner matrix particles by the suspension polymerization method, the polymerizable monomer composition repeats coalescence, shearing, and coalescence in the granulation step. In these two phenomena, when shearing is more likely to occur than coalescence, fine particles are more likely to be generated, and the polymerizable monomer composition is stably present as oil droplets in an aqueous medium. Dispersant is deprived of the fine particles. As a result, there is not enough dispersant to stabilize the oil droplets having a toner particle size, and uneven toner matrix particles are formed. Although the reason is not clear, the interfacial tension of the amorphous polyester dissolved in styrene / butyl acrylate = 80/20 (mass ratio) in a pH 6.0 tricalcium phosphate aqueous solution is 25 mN / m or more and 38 mN / m. When the following, the balance between the shearing and coalescence of the oil droplets formed by the polymerizable monomer composition in the granulation step is slightly shifted to the shearing side. By doing so, it is thought that it is possible to form ultrafine irregularities while suppressing the generation of fine particles as much as possible. Since a specific site can be easily introduced into the molecular chain of the amorphous polyester, it is preferable to change the molecular chain structure in the amorphous polyester chain as a method for controlling the interfacial tension.

The content of the amorphous polyester is preferably 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the binder resin. More preferably, it is 5.0 parts by mass or more and 25.0 parts by mass or less. When the content is 5.0 parts by mass or more, it becomes easy to control the uneven shape of the surface of the toner matrix particles, and it becomes easy to suppress contamination of the charged member by an external additive or the like. On the other hand, when it is 30.0 parts by mass or less, it becomes easy to suppress the formation of irregularly shaped particles, it becomes easy to suppress cracking and crushing of the toner, and it tends to lead to improvement of fog.

Furthermore, from the viewpoint of facilitating suppression of contamination of charged members by controlling the extremely fine uneven shape of the surface of the toner matrix particles, the amorphous polyester has a monomer unit derived from an alcohol component and a direct chain having 6 or more and 12 or less carbon atoms. It has a monomer unit derived from a chain aliphatic dicarboxylic acid, and is derived from a linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms with respect to all the monomer units derived from the carboxylic acid component in the amorphous polyester. It is preferable to contain the monomer unit in an amount of 10 mol% or more and 70 mol% or less.

As described above, as a preferable means for imparting a surface uneven shape, one is to change the molecular chain structure in the amorphous polyester chain to obtain a polymerizable monomer composition in an aqueous medium. A method of controlling the interfacial tension is preferable. As a result of examination by the present inventors, a molecular chain structure preferable for introduction is, for example, a site derived from a linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms from the viewpoint of easy control of interfacial tension. By doing so, the interfacial tension with respect to water can be reduced as compared with that before the introduction.

It was also found that having a linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms significantly improves the electrostatic offset as an unexpected effect.

The electrostatic offset is a phenomenon that occurs when toner on paper that is insufficiently melted near the fixing nip, not thermally at the time of fixing, electrostatically flies toward the fixing film side. As a result, when the fixing film makes one rotation, the toner flying to the fixing film side is fixed again on the paper, causing image defects. If this electrostatic offset does not occur, the fixing bias mechanism becomes unnecessary, which can greatly contribute to the miniaturization of the main body.

There are two possible policies for improving the electrostatic offset. One is to make the charge distribution of the toner uniform, and the other is to release the charge stored in the toner layer transferred on the paper. This electrostatic offset is a phenomenon that tends to occur in a low-temperature and low-humidity environment where the toner tends to be charged up and the charge distribution tends to be broad.

When the toner matrix particle contains an amorphous polyester having a linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms, the linear aliphatic dicarboxylic acid moiety is neatly folded. As a result, it is considered that the amorphous polyester tends to have a structure like a pseudo-crystalline state, and the electric charge of the toner layer after being transferred onto the paper can be effectively released. Therefore, the electrostatic resistance offset is likely to be improved even in a situation where the toner is likely to be charged up in the latter half of the durability.

When the number of carbon atoms of the linear aliphatic dicarboxylic acid is 6 or more, the linear aliphatic dicarboxylic acid moiety is easily folded, so that it is easy to have a structure like a pseudocrystalline state, and it is possible to easily release the charge. As a result, the electrostatic offset resistance is improved. On the other hand, when the number of carbon atoms of the linear aliphatic dicarboxylic acid is 12 or less, it becomes easy to control the interfacial tension with respect to water, so that it becomes easy to control the extremely fine uneven shape on the surface of the toner matrix particles.

When the content of the monomer unit derived from the linear aliphatic dicarboxylic acid is 10 mol% or more, a large number of charge leak points can be obtained and the electrostatic offset resistance can be easily improved. Further, when the content of the monomer unit derived from the linear aliphatic dicarboxylic acid is 70 mol% or less, it is easy to control the interfacial tension with respect to water, and it is easy to suppress cracking and crushing of the toner. The content of the unit derived from the linear aliphatic dicarboxylic acid is more preferably 20 mol% or more and 50 mol% or less. The "monomer unit" refers to a reacted form of the monomer substance in the polymer.

Examples of the carboxylic acid component for obtaining an amorphous polyester include a linear aliphatic dicarboxylic acid having 6 to 12 carbon atoms and other carboxylic acids. Examples of the linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms include adipic acid, suberic acid, sebacic acid, and 1,12-dodecanedioic acid. Examples of the carboxylic acid other than the linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms include the following.

Examples of the divalent carboxylic acid component include maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, glutaric acid, n-dodecenyl succinic acid, and anhydrides of these acids, lower alkyl esters, and the like. Be done.

Examples of the trivalent or higher polyvalent carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, empol trimeric acid and their acid anhydrides, lower grades. Examples thereof include alkyl esters. Among these, terephthalic acid is preferably used because it can maintain a high peak molecular weight and easily maintain durability.

Examples of the alcohol component for obtaining the amorphous polyester include the following in addition to the propylene oxide adduct of bisphenol A. Examples of the divalent alcohol component include ethylene oxide adduct of bisphenol A, ethylene glycol, 1,3-propylene glycol, neopentyl glycol and the like. Examples of the trihydric or higher alcohol component include sorbitol, pentaerythritol, dipentaerythritol and the like.

The divalent alcohol component and the trihydric or higher polyhydric alcohol component can be used alone or in combination of a plurality of compounds. Among these, an alcohol component derived from bisphenol A is preferably used as the alcohol component.

The amorphous polyester can be produced by an esterification reaction or a transesterification reaction using the above alcohol component and carboxylic acid component. In the case of polycondensation, a known esterification catalyst such as dibutyl tin oxide may be appropriately used in order to promote the reaction.

The molar ratio (carboxylic acid component / alcohol component) of the alcohol component and the carboxylic acid component, which are the raw material monomers of the amorphous polyester, is preferably 0.60 or more and 1.00 or less.

The glass transition temperature (Tg) of the amorphous polyester is preferably 45 ° C. or higher and 75 ° C. or lower from the viewpoint of fixability and heat storage stability. The glass transition temperature (Tg) can be measured with a differential scanning calorimeter (DSC).

The peak molecular weight (Mp (P)) of the amorphous polyester is preferably 8000 or more and 13000 or less, and the softening point is preferably 85 ° C. or more and 105 ° C. or less.

When the peak molecular weight (Mp (P)) is 8000 or more, it becomes easy to suppress cracking and crushing of the toner during long-term use. Further, when the peak molecular weight (Mp (P)) is 13000 or less, melting by heat occurs instantly, so that the toner layer can be sufficiently adhered to the paper.

Further, when the softening point of the amorphous polyester is 85 ° C. or higher, it becomes easy to suppress cracking and crushing of the toner through durability. Further, when the softening point is 105 ° C. or lower, melting due to heat occurs instantaneously, so that the toner layer can be sufficiently adhered to the paper.

In order to control the peak molecular weight and softening point of the amorphous polyester in the above range, it is preferable to contain a unit derived from a linear aliphatic dicarboxylic acid having 6 or more and 12 or less carbon atoms in the above range.

Further, it is preferable that a matrix-domain structure is observed in a cross section of the toner observed by a transmission electron microscope (TEM), a vinyl resin forms a matrix, and an amorphous polyester forms a domain. Then, the domain may be present within 75% of the distance between the contour and the center point of the cross section from the contour of the cross section by 96 area% or more based on the total area of the domain of the amorphous polyester. preferable.

When the area ratio of the amorphous polyester domain (hereinafter, also referred to as "75% area ratio") existing within 75% of the distance between the contour and the center point of the cross section from the contour of the toner cross section is 96 area% or more. If there is, the amorphous polyester becomes unevenly distributed on the outside as a whole, so that the charge can be easily released from the toner layer of the image after transfer, and the electrostatic offset is easily improved. More preferably, it is 98 area% or more.

Next, it is preferable that the number average particle size of the amorphous polyester domain is 0.3 μm or more and 3.0 μm or less. More preferably, it is 0.3 μm or more and 2.0 μm or less. When the number average particle size of the domains is 0.3 μm or more and 3.0 μm or less, it becomes possible to control the existence state of the domains in the toner mother particles and reduce the variation of the domains among the toner mother particles.

As a measure for forming an amorphous polyester domain near the surface of the toner mother particle and controlling the number average diameter of the amorphous polyester domain, the acid value and the hydroxyl value of the amorphous polyester are adjusted, and the amorphous property is formed. Addition of lipophilic site to the end of the molecular chain of polyester, adjustment of softening point of amorphous polyester and toner, and adjustment of production conditions of toner matrix particles, for example, cooling step after completion of polymerization, holding time after cooling, etc. Can be mentioned.

In this way, in order to control the number average particle diameter of the amorphous polyester forming domains near the surface of the toner mother particles, for example, in the case of the suspension polymerization method, the acid value of the amorphous polyester and the acid value of the amorphous polyester It can be controlled by the hydroxyl value. Further, it can be adjusted by providing a lipophilic portion described later at the end of the molecular chain of the amorphous polyester, controlling the softening point of the amorphous polyester and the toner, and controlling the annealing conditions at the time of toner production.

Examples of the method for controlling the surface uneven shape of the toner matrix particles include a method of controlling the surface uneven shape of the toner matrix particles by a suspension polymerization method in the manufacturing method and a method of controlling the acid value and the hydroxyl value of the amorphous polyester in the toner material.

It is preferable that the acid value Av (mgKOH / g) and the hydroxyl value OHv (mgKOH / g) of the amorphous polyester satisfy the following formulas (3) and (4).
1.0 ≤ Av ≤ 4.0 ... (3)
2.0 ≤ Av + 0.1 OHv ≤ 8.0 ... (4)

Within the above range, it becomes easy to control the white area ratio, and as a result, it becomes easy to reduce irregularly shaped particles.

Next, it is preferable that the hydroxyl value OHv of the amorphous polyester is 40.0 mgKOH / g or less. For example, when the toner is obtained by a suspension polymerization method, it is preferable that the hydroxyl value OHv of the amorphous polyester is 40.0 mgKOH / g or less because the amorphous polyester easily forms a plurality of domains in the vicinity of the toner surface. ..

In order to control the acid value Av of the amorphous polyester to 1.0 mgKOH / g or more and 4.0 mgKOH / g or less and the hydroxyl value OHv to 40.0 mgKOH / g or less, the molecular chain end of the amorphous polyester is used. It is preferable to have a lipophilic part.

Since the end of the molecular chain of the amorphous polyester has a lipophilic site, it is easy to interact with the vinyl resin, so that it is easy to control the size of the domain.

In order to have a lipophilic site at the end of the molecular chain, it is preferable to react a compound having a lipophilic site at the end of the molecular chain of the amorphous polyester.

As the compound having a lipophilic moiety, an aliphatic monoalcohol having 10 or more and 50 or less carbon atoms and / or an aliphatic monocarboxylic acid having 11 or more and 51 or less carbon atoms are preferable. These compounds include dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), docosanoic acid (behenic acid), tetracosanoic acid. (Lignoceric acid), caprin alcohol, lauric alcohol, myristic alcohol, cetanol, stearic acid, arachidic acid, behenic acid, lignoceryl alcohol and the like can be mentioned.

The number average particle size (D1) of the toner of the present invention is preferably 5.0 μm or more and 9.0 μm or less. When the number average particle diameter (D1) is in the above range, good fluidity can be obtained, and triboelectric charging is likely to occur uniformly at the regulation portion, so that fog is likely to improve.

If necessary, the toner mother particles may contain a charge control agent in order to improve the charge characteristics. Various types of charge control agents can be used, but a charge control agent that has a high charge speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner is produced by a polymerization method as described later, a charge control agent having low polymerization inhibitory property and substantially no solubilized product in the aqueous dispersion medium is particularly preferable. As a charge control agent
Metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid;
Metal salts or metal complexes of azo dyes or azo pigments;
Polymeric compounds with sulphonic acid or carboxylic acid groups in the side chains;
Boron compound;
Urea compound;
Silicon compound;
Calixarene and the like.

When added to the inside of the toner mother particles, the amount of these charge control agents used is preferably 0.1 part by mass or more and 10.0 parts by mass or less, more preferably 0 parts by mass, based on 100 parts by mass of the binder resin. It is 1 part by mass or more and 5.0 parts by mass or less. When added to the outside of the toner mother particles, it is preferably 0.005 parts by mass or more and 1.000 parts by mass or less, and more preferably 0.010 parts by mass or more and 0.300 parts by mass with respect to 100 parts by mass of the toner mother particles. It is less than a part.

The toner mother particles may contain a mold release agent in order to improve the fixability. The content of the mold release agent in the toner mother particles is preferably 1.0 part by mass or more and 30.0 parts by mass or less, and 3.0 parts by mass or more and 25.0 parts by mass with respect to 100 parts by mass of the binder resin. More preferably, it is less than or equal to a part.

When the content of the release agent is 1.0 part by mass or more, it becomes easy to control the presence state of the release agent as described above, so that it becomes easier to suppress white spots. Further, if it is 30.0 parts by mass or less, it becomes easy to suppress toner deterioration during long-term use.

As a release agent,
Petroleum waxes such as paraffin wax, microcrystalline wax, petrolatum and their derivatives;
Montan wax and its derivatives;
Hydrocarbon wax by Fischer-Tropsch method and its derivatives;
Polyolefin waxes such as polyethylene and their derivatives;
Examples thereof include natural waxes such as carnauba wax and candelilla wax and derivatives thereof. Derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Further, fatty acids such as higher fatty alcohols, stearic acid and palmitic acid, acid amide waxes, ester waxes, hardened castor oil and its derivatives, vegetable waxes, animal waxes and the like can also be used as mold release agents.

Among these release agents, paraffin wax is preferably used from the viewpoint of easily suppressing toner cracking and crushing.

Further, the melting point defined by the maximum endothermic peak temperature at the time of temperature rise measured by a differential scanning calorimeter (DSC) of these release agents is preferably 60 ° C. or higher and 140 ° C. or lower, and 65 ° C. or higher and 120 ° C. More preferably, it is below ° C. When the melting point is 60 ° C. or higher, it becomes easy to suppress toner deterioration during long-term use. When the melting point is 140 ° C. or lower, the low temperature fixability is unlikely to decrease.

The melting point of the release agent shall be the peak top of the endothermic peak measured by DSC. The peak top of the endothermic peak is measured according to ASTM D 3417-99. For these measurements, for example, a DSC-7 manufactured by PerkinElmer, a DSC2920 manufactured by TA Instrument, and a Q1000 manufactured by TA Instrument can be used. The melting point of indium and zinc is used for the temperature correction of the device detection unit, and the heat of fusion of indium is used for the correction of the calorific value. An aluminum pan is used as the measurement sample, and an empty pan is set as a control for measurement.

Next, the colorant will be described.

As the black colorant, carbon black, magnetic fine particles, and those toned to black using the following yellow / magenta / cyan colorants are used.

Another effective means for downsizing the printer is a one-component development method. It is also an effective means to eliminate the supply roller that supplies the toner in the cartridge to the toner carrier.

As a one-component developing method omitting such a supply roller, a magnetic one-component developing method is preferable, and as a toner colorant, a magnetic toner using a magnetic material is preferable. By using such a magnetic toner, it is possible to have high transportability and coloring property.

When the suspension polymerization method is applied as the toner production method, it is preferable to use hydrophobized magnetic fine particles, and the degree of hydrophobization is preferably 60.0% or more and 80.0% or less. .. Within the above range, the magnetic fine particles are oriented near the surface of the toner matrix particles, which makes the surface more resistant to external stress, and at the same time, imparts a finer uneven shape to the surface while having a low white area ratio. Therefore, it brings about a further effect of suppressing contamination of charged members.

The magnetic fine particles preferably contain magnetic iron oxide such as triiron tetraoxide or γ-iron oxide as the main component, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. The BET specific surface area of these magnetic fine particles by the nitrogen adsorption method ^{is preferably 2 m 2} / g or more and 30 m 2 / g or less, and ^{more preferably 3 m 2} / g or more and 28 m ² / g or less. Further, those having a Mohs hardness of 5 to 7 are preferable. The shape of the magnetic fine particles includes a polyhedron, an octahedron, a hexahedron, a sphere, a needle, and a scaly shape. However, a polyhedron, an octahedron, a hexahedron, a sphere, and the like having less anisotropy increase the image density. Preferred above.

The magnetic fine particles preferably have a number average particle size of 0.10 μm or more and 0.40 μm or less. When the number average particle size is 0.10 μm or more, the magnetic fine particles are less likely to aggregate, and the uniform dispersibility of the magnetic fine particles in the toner is improved. Further, when the number average particle size is 0.40 μm or less, the coloring power of the toner is improved, so that it is preferably used.

The number average particle diameter of the magnetic fine particles can be measured using a transmission electron microscope. Specifically, after sufficiently dispersing the toner mother particles to be observed in the epoxy resin, the cured product is obtained by curing in an atmosphere at a temperature of 40 ° C. for 2 days. The obtained cured product is used as a flaky sample by a microtome, and the diameters of 100 magnetic fine particles in the field of view are measured with a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. Then, the number average particle diameter is calculated based on the equivalent diameter of the circle equal to the projected area of the magnetic fine particles. It is also possible to measure the particle size with an image analyzer.

The magnetic fine particles used in the toner of the present invention can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide to the ferrous salt aqueous solution in an equivalent amount or an equivalent amount or more with respect to the iron component. Air is blown while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and the ferrous hydroxide oxidation reaction is carried out while heating the aqueous solution to 70 ° C. or higher to first form seed crystals that are the core of the magnetic iron oxide powder. Generate.

Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the liquid at 5 to 10, the reaction of ferrous hydroxide is promoted while blowing air, and the magnetic iron oxide powder is grown around the seed crystal. At this time, it is possible to control the shape and magnetic characteristics of the magnetic fine particles by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction progresses, the pH of the liquid shifts to the acidic side, but it is preferable that the pH of the liquid is not less than 5. Magnetic fine particles can be obtained by filtering, washing, and drying the magnetic fine particles thus obtained by a conventional method.

Further, as described above, when the toner is produced by the turbidity polymerization method in the present invention, it is very preferable to hydrophobize the surface of the magnetic fine particles because it is easy to enclose the magnetic fine particles in the toner. When surface treatment is performed by a dry method, the magnetic fine particles that have been washed, filtered, and dried are treated with a coupling agent. When the surface treatment is performed wet, the dried iron oxide is redispersed after the oxidation reaction is completed, or the iron oxide obtained by washing and filtering after the oxidation reaction is completed in another aqueous medium without drying. Is redistributed and the coupling process is performed. Specifically, the coupling treatment is performed by adding a silane coupling agent while sufficiently stirring the redispersion liquid to raise the temperature after hydrolysis, or by adjusting the pH of the dispersion liquid to an alkaline range after hydrolysis. .. Among these, from the viewpoint of performing a uniform surface treatment, it is preferable to perform surface treatment by reslurrying as it is without drying after completion of the oxidation reaction, filtration and washing.

In order to treat the surface treatment of the magnetic fine particles wet, that is, to treat the magnetic fine particles with a coupling agent in an aqueous medium, first sufficiently disperse the magnetic fine particles in the aqueous medium so as to have a primary particle size, and prevent sedimentation and aggregation. Stir with a stirring blade or the like. Next, an arbitrary amount of the coupling agent is added to the above dispersion liquid, and the surface treatment is performed while hydrolyzing the coupling agent. At this time as well, the coupling agent is sufficiently stirred and not aggregated while using a device such as a pin mill or a line mill. It is more preferable to perform surface treatment while dispersing.

Here, the aqueous medium is a medium containing water as a main component. Specific examples thereof include water itself, water to which a small amount of surfactant is added, water to which a pH adjuster is added, and water to which an organic solvent is added. As the surfactant, a nonionic surfactant such as polyvinyl alcohol is preferable. The surfactant is preferably added in an amount of 0.1 part by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid. Examples of the organic solvent include alcohols and the like.

Examples of the coupling agent that can be used in the surface treatment of the magnetic fine particles in the present invention include a silane compound, a silane coupling agent, and a titanium coupling agent. More preferably, a silane compound or a silane coupling agent is used, which is represented by the general formula (1).
R _m SiY _n General formula (1)
[In the formula, R represents an alkoxy group, m represents an integer from 1 to 3, Y represents a functional group such as an alkyl group, a phenyl group, a vinyl group, an epoxy group, or a (meth) acrylic group, and n is 1. Indicates an integer from 3 to 3. However, m + n = 4. ]

Examples of the silane compound or silane coupling agent represented by the general formula (1) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and β- (3,4 epoxycyclohexyl) ethyltri. Methoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltri Methoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltri Methoxysilane, isobutyltrimethoxysilane, trimethylmethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-octyltrimethoxysilane, n-decyltrimethoxysilane, hydroxypropyltrimethoxysilane, n-hexadecyl Examples thereof include trimethoxysilane and n-octadecyltrimethoxysilane.

Among these, from the viewpoint of imparting high hydrophobicity to the magnetic fine particles, it is preferable to use the alkyltrialkoxysilane represented by the following general formula (2).
C _p H _{2p + 1} −Si− (OC _q H _{2q + 1} ) ₃ (2)
[In the formula, p represents an integer of 2 to 20 (more preferably 3 to 15), and q represents an integer of 1 to 3 (more preferably 1 or 2). ]

When p in the above formula is 2 or more, it becomes easy to sufficiently impart hydrophobicity to the magnetic fine particles. Further, when p is 20 or less, in addition to sufficient hydrophobicity, coalescence of magnetic fine particles can be suppressed. Further, when q is 3 or less, the reactivity of the silane coupling agent is good and the hydrophobicity becomes sufficient.

When the above silane coupling agent is used, it can be treated alone or in combination of a plurality of types. When a plurality of types are used in combination, they may be treated individually with each coupling agent or may be treated at the same time.

In the present invention, other colorants may be used in combination with the magnetic fine particles. Examples of the colorant that can be used in combination include the above-mentioned known dyes and pigments, as well as magnetic or non-magnetic inorganic compounds. Specifically, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements, etc. to these. Particles such as hematite, titanium black, niglosin dye / pigment, carbon black, phthalocyanine and the like can be mentioned. These are also preferably surface-treated and used.

The amount contained in the toner mother particles is preferably 20 parts by mass or more and 200 parts by mass or less, and more preferably 40 parts by mass or more with respect to 100 parts by mass of the polymerizable monomer or the binder resin that produces the binder resin. It is 150 parts by mass or less.

Examples of the yellow colorant include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 128, 129, 138, 147, 150, 151, 154, 155, 168, 180, 185, 214 can be mentioned.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, the following C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221 238, 254, 269, C.I. I. Pigment Bio Red 19.

Examples of the cyan colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

These colorants can be used alone or in the form of a solid solution. The colorant is selected in terms of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner. The amount of the colorant added is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer or the binder resin that produces the binder resin.

When the toner matrix particles are produced by the pulverization method, for example, the toner components such as a binder resin and a colorant and, if necessary, a mold release agent and other additives are sufficiently mixed with a mixer such as a Henschel mixer or a ball mill. To do. Then, it is melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder to disperse or melt the above-mentioned materials, cool and solidify them, crush them, classify them, and perform surface treatment as necessary. Toner mother particles can be obtained. Either of the order of classification and surface treatment may come first. In the classification process, it is preferable to use a multi-division classifier from the viewpoint of production efficiency.

Controlling the dispersed state of the amorphous polyester by the pulverization method can be achieved by a treatment such as external addition of the amorphous polyester. Therefore, in the present invention, it is preferable to produce toner mother particles in an aqueous medium such as a dispersion polymerization method, an association aggregation method, a dissolution suspension method, and a suspension polymerization method, and among them, the suspension polymerization method is more preferable. .. By adopting these manufacturing methods, it becomes easier to achieve the above-mentioned unevenness control on the surface of the toner matrix particles.

The suspension polymerization method includes a polymerizable monomer that produces a binder resin, an amorphous polyester, and a colorant (and, if necessary, a mold release agent, a polymerization initiator, a cross-linking agent, a charge control agent, and the like. Other additives) are dissolved or dispersed to obtain a polymerizable monomer composition. The polymerizable monomer composition is then added into a continuous phase (eg, an aqueous medium (which may optionally contain a dispersion stabilizer)). Then, the particles of the polymerizable monomer composition are formed in the continuous phase (in the aqueous medium), and the polymerizable monomer contained in the particles is polymerized. By doing so, it is a method of obtaining toner. Toners obtained by the suspension polymerization method (hereinafter, also referred to as "polymerized toners") have almost spherical shapes of individual toner matrix particles, so that the fluidity at the regulation part is easily improved and the toner is uniformly rubbed. Since it is easy to be charged, it is easy to suppress fog and it is easy to improve the image quality.

Examples of the polymerizable monomer used for producing the polymerized toner include the following.

As a polymerizable monomer,
Styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene;
Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, Acrylic acid esters such as phenyl acrylate;
Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacrylic acid Methacrylic acid esters such as dimethylaminoethyl and diethylaminoethyl methacrylate;
And so on. In addition, acrylonitrile, methacrylonitrile, acrylamide and the like can also be mentioned. These can be used alone or in combination of two or more.

Among the above-mentioned polymerizable monomers, it is preferable to use styrene or a styrene derivative alone or in combination of two or more from the viewpoint of toner development characteristics and durability.

The polymerizable monomer composition preferably contains a polar resin. In the suspension polymerization method, the toner matrix particles are produced in an aqueous medium. Therefore, by containing the polar resin, the polar resin can be present on the surface of the toner matrix particles, and the chargeability can be easily improved. Easy to control fog.

As the polar resin, for example
Monopolymers of styrene such as polystyrene and polyvinyltoluene and their substitutes;
Styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, Styrene-octyl acrylate copolymer, dimethylaminoethyl styrene-acrylate copolymer, methyl styrene-methacrylate copolymer, ethyl styrene-ethyl methacrylate copolymer, butyl styrene-butyl methacrylate copolymer, Styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinylmethyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinylmethylketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer Styrene-based copolymers such as coalescence, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer;
Examples thereof include polymethylmethacrylate, polybutylmethacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyamide resin, epoxy resin, polyacrylic acid resin, terpene resin, and phenol resin. These can be used alone or in combination of two or more. Further, functional groups such as an amino group, a carboxy group, a hydroxyl group, a sulfonic acid group, a glycidyl group and a nitrile group may be introduced into these polymers.

The polymerization initiator used in the production of the toner by the polymerization method preferably has a half-life of 0.5 hours or more and 30.0 hours or less at the time of the polymerization reaction. Further, when the polymerization reaction is carried out by using an addition amount of 0.5 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer, the toner can be given desired strength and appropriate melting characteristics. it can.

Specific examples of the polymerization initiator are 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 1,1'-azobis (cyclohexane-1). -Carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl Peroxide-based polymerization initiators such as peroxycarbonate, cumenehydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy2-ethylhexanoate, and t-butylperoxypivalate. Can be mentioned.

When the toner mother particles are produced by the polymerization method, a cross-linking agent may be added, and the preferable addition amount is 0.01 part by mass or more and 5.00 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Is.

Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used, and for example, a compound having two or more polymerizable double bonds is used.
Aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene;
Carboxylate ester having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate;
Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone;
Compounds having three or more vinyl groups are used alone or as a mixture of two or more.

When the toner matrix particles are produced by a polymerization method, preferably, the above-mentioned toner composition or the like is added and uniformly dissolved or dispersed by a disperser to obtain a polymerizable monomer composition. Examples of the disperser include a homogenizer, a ball mill, and an ultrasonic disperser. The obtained polymerizable monomer composition is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner matrix particles becomes sharper when the desired toner size is set at once by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser. The polymerization initiator may be added at the same time as the other additives are added to the polymerizable monomer, or may be mixed immediately before suspension in the aqueous medium. It is also possible to add a polymerization initiator immediately after granulation and before starting the polymerization reaction.

After granulation, a normal stirrer may be used to stir the particles to such an extent that the state of the particles is maintained and the floating and sedimentation of the particles are prevented.

In the case of producing toner, various surfactants, organic dispersants and inorganic dispersants can be used as dispersion stabilizers. Among them, the inorganic dispersant can be preferably used because it is less likely to generate harmful ultrafine powder and has obtained dispersion stability due to its steric hindrance. Examples of such inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, hydroxyapatite and other phosphoric acid polyvalent metal salts, calcium carbonate, magnesium carbonate and other carbonates, calcium metasilicate, calcium sulfate and sulfuric acid. Examples thereof include inorganic salts such as barium, and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

It is desirable to use 0.2 parts by mass or more and 20.0 parts by mass or less of these inorganic dispersants with respect to 100 parts by mass of the polymerizable monomer. Further, the dispersion stabilizer may be used alone or in combination of two or more. Further, a surfactant may be used in combination.

In the step of polymerizing the polymerizable monomer, the polymerization temperature is usually set to 40 ° C. or higher, preferably 50 ° C. or higher and 90 ° C. or lower. When the polymerization is carried out in this temperature range, the release agent to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete.

In order to obtain the toner having the domain of the amorphous polyester by the suspension polymerization method, it is preferable to carry out the following steps.

After the polymerization of the polymerizable monomer is completed to obtain colored particles, in a state where the colored particles are dispersed in an aqueous medium, the softening point of the amorphous polyester (for example, the softening point of the amorphous polyester + 10 ° C.) ), Specifically, the temperature is raised to about 100 ° C., and the temperature is preferably maintained for 30 minutes or more. The upper limit is not particularly limited, but from the viewpoint of manufacturing tact, it is preferably held for 24 hours or less.

Further, it is preferable to perform the following operations in the subsequent cooling step. Specifically, it is preferable to cool the aqueous medium to a glass transition temperature (Tg) or less of the toner at a cooling rate of 5.0 ° C./min or more, and it is more preferable to cool the aqueous medium at a cooling rate of 20 ° C./min or more. It is more preferable to cool at a speed of 100 ° C./min or higher. The upper limit of the cooling rate is about 500 ° C./min or less from the viewpoint of manufacturing tact.

Further, after cooling at the above cooling rate, it is preferable to keep the temperature at that temperature for 30 minutes or more. The holding time is more preferably 60 minutes or more, and further preferably 120 minutes or more. The upper limit of the holding time is not particularly limited, but is about 24 hours or less from the viewpoint of manufacturing tact.

Toner matrix particles are obtained by filtering, washing, and drying the obtained polymer particles.

The toner matrix particles can be used as they are as the toner, but it is also possible to externally mix the toner matrix particles with inorganic fine particles as described later to obtain a toner in which the inorganic fine particles adhere to the surface of the toner matrix particles. It is also possible to insert a classification step in the manufacturing process (before mixing the inorganic fine particles) to cut the coarse powder and fine powder contained in the particles.

Further, it is preferable that inorganic fine particles having an average number of primary particles of 4 nm or more and 80 nm or less, more preferably 6 nm or more and 40 nm or less are added (externally added) to the toner matrix particles as a fluidizing agent. .. Further, it is more preferable to use inorganic fine particles having an average number of primary particles of 80 nm or more and 200 nm or less in combination. By doing so, the fluidity of the toner can be ensured through durability, uniform and stable triboelectric performance can be obtained, and fog and electrostatic offset can be easily improved. Inorganic fine particles are added to improve the fluidity of the toner and homogenize the charge of the toner, but the inorganic fine particles are treated to hydrophobize the inorganic fine particles to adjust the charge amount of the toner and improve the environmental stability. It is also a preferable form to give.

In the present invention, the method for measuring the number average diameter of the primary particles of the inorganic fine particles is performed by using a photograph of the toner magnified by a scanning electron microscope.

As the inorganic fine particles used in the present invention, fine particles such as silica, titanium oxide, and alumina can be used. Examples of the silica fine particles include so-called dry silica produced by vapor phase oxidation of a silicon halide or fumed silica, and so-called wet silica produced from water glass or the like.

However, dry silica having less silanol groups on the surface and inside of silica and less production residue such as _{Na 2} O and SO ₃ ^{2- is preferable.} Further, in dry silica, it is also possible to obtain composite fine particles of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the manufacturing process. , Including them.

The amount of the inorganic fine particles added is preferably 0.1 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the toner mother particles. The content of the inorganic fine particles can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

In the present invention, it is preferable that the inorganic fine particles are hydrophobized because the environmental stability of the toner can be improved. Examples of the treatment agent used for the hydrophobic treatment of the inorganic fine particles include silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, and silane coupling agents. Further, other treatment agents such as organosilicon compounds and organotitanium compounds can be mentioned. These can be used alone or in combination of two or more.

Among the above-mentioned treatment agents, those treated with silicone oil are preferable, and those treated with silicone oil at the same time or after treating the inorganic fine particles with a silane compound are more preferable. As a method for treating such inorganic fine particles, for example, as a first-stage reaction, a silylation reaction is carried out with a silane compound to eliminate silanol groups by chemical bonds, and then as a second-stage reaction, silicone oil is applied to the surface. A hydrophobic thin film can be formed.

The silicone oil is preferably a viscosity at 25 ° C. is 10 mm ² / s or more 200,000 mm ² / s or less things, more preferably the following 3,000 mm ² / s or more 80,000mm ² / s.

As the silicone oil used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorphenyl silicone oil, fluorine modified silicone oil and the like are particularly preferable.

Examples of the method of treating the inorganic fine particles with silicone oil include a method of directly mixing the inorganic fine particles treated with a silane compound and silicone oil using a mixer such as a Henshell mixer, or a method of spraying silicone oil on the inorganic fine particles. The method can be mentioned. Alternatively, a method may be used in which the silicone oil is dissolved or dispersed in an appropriate solvent, and then inorganic fine particles are added and mixed to remove the solvent. A method of spraying is more preferable because the formation of aggregates of inorganic fine particles is relatively small.

The treatment amount of the silicone oil is preferably 1 part by mass or more and 40 parts by mass or less, and more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the inorganic fine particles. Within this range, good hydrophobicity can be easily obtained.

The inorganic fine particles used in the present invention preferably have a specific surface area of 20 m ² / g or more and 350 m ² / g or less as measured by the BET method by nitrogen adsorption in order to impart good fluidity to the toner, preferably 25 m. ² / g or more 300 meters ² / g following are more preferable. The specific surface area is calculated by adsorbing nitrogen gas on the sample surface using the specific surface area measuring device "Gemini 2375 Ver.5.0" (manufactured by Shimadzu Corporation) according to the BET method and using the BET multipoint method. ..

The toner of the present invention includes still other additives such as, for example.
Lubricants particles such as fluororesin particles, zinc stearate particles, polyvinylidene fluoride particles;
Abrasives such as cerium oxide particles, silicon carbide particles, strontium titanate particles;
Fluidity-imparting agents such as titanium oxide particles and aluminum oxide particles;
Anti-caking agent;
A small amount of organic fine particles and inorganic fine particles having opposite polarities can also be used as a developable improver. It is also possible to hydrophobize the surface of these additives before use.

Next, a developing apparatus to which the toner of the present invention can be publicly applied will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an example of a developing device. Further, FIG. 2 is a schematic cross-sectional view showing an example of an image forming apparatus incorporating a developing apparatus.

In FIG. 1 or 2, the electrostatic latent image carrier 45, which is an image carrier on which the electrostatic latent image is formed, is rotated in the direction of arrow R1. By rotating the toner carrier 47 in the direction of arrow R2, the toner 57 is conveyed to the developing region where the toner carrier 47 and the electrostatic latent image carrier 45 face each other. Further, the toner supply member 48 is in contact with the toner carrier, and the toner 57 is supplied to the surface of the toner carrier by rotating in the direction of arrow R3.

A charging roller 46, a transfer roller 50, a fixing device 51, a pickup roller 52, and the like are provided around the electrostatic latent image carrier 45. The electrostatic latent image carrier 45 is charged by the charging roller 46. Then, the laser beam 54 irradiates the electrostatic latent image carrier 45 with laser light to perform exposure, and an electrostatic latent image corresponding to the target image is formed. The electrostatic latent image on the electrostatic latent image carrier 45 is developed with the toner in the developer 49 to obtain a toner image. The toner image is transferred onto the transfer material (paper) 53 by the transfer member (transfer roller) 50 that is in contact with the electrostatic latent image carrier 45 via the transfer material. The transfer material (paper) 53 on which the toner image is placed is carried to the fixing device 51 and fixed on the transfer material (paper) 53.

In the charging process in the developing apparatus, the electrostatic latent image carrier and the charging roller form a contact portion and come into contact with each other, and a predetermined charging bias is applied to the charging roller to make the surface of the electrostatic latent image carrier having a predetermined polarity. It is preferable to use a contact charging device that charges the potential. By performing contact charging in this way, stable and uniform charging can be performed, and the generation of ozone can be reduced. Further, in order to maintain uniform contact with the electrostatic latent image carrier and perform uniform charging, it is more preferable to use a charging roller that rotates in the same direction as the electrostatic latent image carrier.

Next, it is preferable that the toner regulating member abuts on the toner carrier via the toner to regulate the toner layer thickness on the toner carrier. By doing so, it is possible to obtain high image quality without any improper regulation. As the toner regulating member that comes into contact with the toner carrier, a regulating blade is generally used, and can be suitably used in the present invention.

The development step is preferably a step of applying a development bias to the toner carrier to transfer the toner to the electrostatic latent image on the electrostatic latent image carrier to form a toner image, and the applied development bias is a DC voltage or It may be a voltage obtained by superimposing an alternating electric field on a DC voltage.

As the waveform of the alternating electric field, a sine wave, a rectangular wave, a triangular wave, or the like can be appropriately used. Further, it may be a pulse wave formed by periodically turning on / off the DC power supply. As described above, as the waveform of the alternating electric field, a bias in which the voltage value changes periodically can be used.

When a method of transporting toner by magnetism without using a toner supply member is used in the present invention, it is preferable to arrange a magnet inside the toner carrier (reference numeral 59 in FIG. 3). In this case, the toner carrier preferably has a fixed magnet having multiple poles inside, and preferably has 3 to 10 poles of magnetic poles.

Next, a method for measuring each physical property according to the present invention will be described.

<Measurement method of white area ratio of toner matrix particles>
When observing the surface of the toner matrix particles with a scanning electron microscope (SEM) in a toner in which an external additive is added to the toner matrix particles, it is necessary to remove the external additive. For example, the following methods can be mentioned.

-When the toner is magnetic toner (1) Put 45 mg of magnetic toner in a sample bottle and add 10 mL of methanol.
(2) Disperse the sample for 1 minute with an ultrasonic cleaner to separate the external additive.
(3) Suction filtration (10 μm membrane filter) is performed to separate the magnetic toner mother particles and the external additive. Alternatively, a magnet may be placed on the bottom of the sample bottle to fix the magnetic toner mother particles and separate only the supernatant liquid.
(4) The above (2) and (3) are performed a total of three times, and the obtained magnetic toner mother particles are sufficiently dried in a vacuum dryer at room temperature. After observing the magnetic toner mother particles from which the external additive has been removed with a scanning electron microscope and confirming that the external additive has disappeared, the surface of the magnetic toner mother particles can be observed with a scanning probe microscope. If the external additive is not sufficiently removed, the surface of the magnetic toner matrix particles is observed by SEM after repeating (2) and (3) until the external additive is sufficiently removed. As another method for removing the external additive instead of the above (2) and (3), there is a method of dissolving the external additive with an alkaline solution. As the alkali, an aqueous sodium hydroxide solution is preferable.

-For non-magnetic toner Add 160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) to 100 mL of ion-exchanged water and dissolve in a water bath to prepare a sucrose concentrate. 31 g of the sucrose concentrate and 6 mL of Contaminone N are placed in a centrifuge tube to prepare a dispersion. 1 g of toner is added to this dispersion, and the toner lumps are loosened with a spatula or the like.

The centrifuge tube is shaken with the shaker for 20 minutes under the condition of 350 reciprocations per minute. After shaking, the solution is replaced with a glass tube for a swing rotor (50 mL), and centrifugation is performed at 3500 rpm for 30 minutes with a centrifuge. In the glass tube after centrifugation, the toner matrix particles are present in the uppermost layer and the silica fine particles are present on the aqueous solution side of the lower layer, so that only the toner matrix particles in the uppermost layer are recovered.

If the external additive has not been sufficiently removed, centrifugation is repeated as necessary, and after sufficient separation, the toner solution is dried to collect toner matrix particles.

The measurement of the white area ratio is as follows.

The toner mother particle image is obtained by an SE image with a magnification of 2000 times with a Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation). In addition, the accelerating voltage is 2.0 kV, the accelerating current is 10.0 μA, the probe current is Normal, the focal mode is UHR, and the WD is 5.0 mm. Since the subsequent image processing is performed on 100 toner particles, the number of images obtained is sufficient to obtain a clear toner matrix particle image of 100 particles.

The white area ratio is calculated by analyzing the obtained image with the image analysis software ImageJ (developer Wayne Rashand). The measurement procedure is shown below.

0.8 ≤ R / D 4 ≤ with respect to the mass-based circle-equivalent weight average diameter D4 (μm) of toner measured by the particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter). Select 100 toners having a major axis R (μm) satisfying the relationship of 1.2. As shown in FIG. 4, the image analysis area selects a relatively flat portion (a field of view in which the entire observation surface is in focus) on each side of the major axis R / 2 (μm) from the center of gravity of the toner surface for observing the surface.

First of all, the analysis procedure by image processing software
1) Display the outline of the toner matrix particles by selecting [Process]-[Find Edge].
2) Binarize with [Image]-[Adjust]-[Threshold], confirm that the contours of the toner matrix particles are connected by a single line, determine the threshold value, and perform [Apply].
3) Select [Analysis]-[Analysis Party], set the range of [Size (pixel ∧ 2)] to 10-infinity, and set the range of [Circulus] to 0.00 to 1.00. Furthermore, select Masks in [Show] and put a check mark in [include holes].
4) After that, select [Transient-White] as the Transfer Mode in [Edit]-[Paste Control], and copy it in [Edit]-[Copy].
5) Open the original image with [File]-[Open], and paste the image created and copied in 4) with [Edit]-[Paste].
6) Invert black and white with [Edit]-[Invert].
7) Set a threshold value by selecting [Image]-[Adjust]-[Threshold], and perform [Apply]. (Set to a value that does not leave noise on the contour of the surface of the toner matrix particle to be measured)
8) Check [Area] in [Analyze]-[Set Measurements].
9) Specify the range of the above image analysis area, record the value of 0 (white) and the total count number with [Analyze]-[Histogram]-[List], and set the white area ratio of one toner matrix particle. calculate.
10) The measurement is performed in the same manner for 100 toner mother particles to be measured, and the average value is taken as the white area ratio of the present invention.

<Measurement method of softening point of toner and amorphous polyester>
The softening points of toner and amorphous polyester are measured using a constant load extrusion type thin tube rheometer "Flow Tester CFT-500D" (manufactured by Shimadzu Corporation) according to the manual attached to the device. In this device, while applying a constant load from the top of the measurement sample with a piston, the temperature of the measurement sample filled in the cylinder is raised and melted, and the melted measurement sample is pushed out from the die at the bottom of the cylinder. A flow curve showing the relationship between and temperature can be obtained.

In the present invention, the softening point is the "melting temperature in the 1/2 method" described in the manual attached to the "flow characteristic evaluation device flow tester CFT-500D". The melting temperature in the 1/2 method is calculated as follows. First, 1/2 of the difference between the piston descent amount Smax at the time when the outflow ends and the piston descent amount Smin at the time when the outflow starts is obtained (this is defined as X. X = (Smax-Smin) / 2). Then, the temperature of the flow curve when the amount of descent of the piston is the sum of X and Smin in the flow curve is the melting temperature in the 1/2 method.

The measurement sample is about 60 g of toner or amorphous polyester at about 10 MPa in an environment of 25 ° C. using a tablet molding compressor (for example, NT-100H, manufactured by NPA System Co., Ltd.). A columnar product having a diameter of about 8 mm is used by compression molding for seconds.

The measurement conditions of CFT-500D are as follows.
Test mode: Hot compress start temperature: 50 ° C
Achieved temperature: 200 ° C
Measurement interval: 1.0 ° C
Heating rate: 4.0 ° C / min
Piston cross-sectional area: 1.000 cm ²
Test load (piston load): 10.0 kgf (0.9807 MPa)
Preheating time: 300 seconds Die hole diameter: 1.0 mm
Die length: 1.0 mm

<Measurement method of true density of toner matrix particles>
When measuring the true density of toner matrix particles in a toner in which an external additive is added to the toner matrix particles, it is necessary to remove the external additive. As a specific method, <white of toner matrix particles It is as described in Measurement method of part area ratio>.

The true density of the toner matrix particles was measured by a dry automatic densitometer auto pycnometer (manufactured by Yuasa Ionics Co., Ltd.). The conditions are as follows.
Cell: SM cell (10 ml)
Sample amount: Approximately 2.0 g

This measuring method measures the true density of solids and liquids based on the gas phase replacement method. Similar to the liquid phase substitution method, it is based on Archimedes' principle, but since gas (argon gas) is used as the substitution medium, the accuracy for micropores is high.

<Measuring method of weight average particle size (D4) and number average particle size (D1) of toner>
The weight average particle size (D4) and number average particle size (D1) of the toner are the precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, Beckman Coulter 3) by the pore electric resistance method equipped with an aperture tube of 100 μm. Calculated by performing measurement and analysis using Coulter) and the attached dedicated software "Beckman Coulter Particle 3 Version 3.51" (Beckman Coulter) for setting measurement conditions and analyzing measurement data. ..

As the electrolytic aqueous solution used for the measurement, a special grade sodium chloride dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter) can be used.

Before measuring and analyzing, the dedicated software was set as follows.

In the dedicated software "Change standard measurement method (SOM) screen", set the total count number in the control mode to 50,000 particles, measure once, and set the Kd value to "standard particles 10.0 μm" (Beckman Coulter). The value obtained using (manufactured by) is set. By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check the flash of the aperture tube after measurement.

In the "pulse to particle size conversion setting screen" of the dedicated software, the bin spacing is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set from 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Approximately 200 ml of the electrolytic aqueous solution is placed in a 250 ml round bottom beaker made of glass dedicated to ultisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the dedicated software.
(2) Approximately 30 ml of the electrolytic aqueous solution is placed in a 100 ml flat-bottomed beaker made of glass, and "Contaminone N" (nonionic surfactant, anionic surfactant, and organic builder) as a dispersant is used as a dispersant for precise measurement of pH 7. Add about 0.3 ml of a diluted solution obtained by diluting a 10% by mass aqueous solution of a neutral detergent for cleaning a vessel, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water 3 times by mass.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and are placed in the water tank of the ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W. A certain amount of ion-exchanged water is added, and about 2 ml of the Contaminone N is added into 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. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic aqueous solution in the beaker is maximized.
(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. In ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) The electrolytic aqueous solution (5) in which toner is dispersed is dropped onto the (1) round bottom beaker installed in the sample stand using a pipette, and the measured concentration is adjusted to about 5%. Then, the measurement is performed until the number of particles to be measured reaches 50,000.
(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) and the number average particle size (D1) are calculated. In addition, when the graph / number% and graph / volume% are set by the dedicated software, the "arithmetic diameter" on the analysis / number statistical value (arithmetic mean) and analysis / volume statistics (arithmetic mean) screens is the number average. The particle size (D1) and the weight average particle size (D4).

<Calculation method of surface unevenness index B / A>
The surface unevenness index is obtained from the theoretical specific surface area A and the BET specific surface area B of the toner matrix particles (= B / A). When measuring the surface unevenness index of the toner matrix particles in a toner in which an external additive is externally added to the toner matrix particles, it is necessary to remove the external additive. As a specific method, <toner matrix The method for measuring the white area ratio of particles> is as described.

Each calculation method is as follows.

<< Calculation method of theoretical specific surface area A of toner matrix particles >>
In the same manner as in the measurement of the number average particle size (D1), the particle size distribution based on the number of toner mother particles was measured. However, in the analysis using "Beckman Coulter Particle 3 Version 3.51" (manufactured by Beckman Coulter), measurement targets are from 2.0 μm to 32.0 μm, and 12 channels (2.00 to 2.520 μm, 2.520 to 3.175 μm, 3.175 to 4.000 μm, 4.000 to 5.040 μm, 5.040 to 6.350 μm, 6.350 to 8.000 μm, 8,000 to 10.079 μm, 10. 079 to 12.699 μm, 12.699 to 16.000 μm, 16.000 to 20.159 μm, 20.159 to 25.398 μm, 25.398 to 32.000 μm) It was.

After that, using the median value of each channel (for example, if the median value is 2.00 to 2.520 μm, the median value is 2.260 μm), it is determined that the toner mother particle of the median value of each channel is a true sphere. Find the theoretical surface area (= 4 × π × (median of each channel) ² ) in the assumed case. By multiplying the theoretical surface area by the number ratio of the particles belonging to each channel obtained earlier, the average theoretical surface area (a) of one particle assuming that the measured toner mother particle is a true sphere is obtained.

Next, the theoretical mass (= 4/3 × π) assuming that the median toner mother particles of each channel are true spheres from the median value of each channel and the true density of the measured toner mother particles in the same manner. × (median value of each channel) ³ × true density) is calculated. The average theoretical mass (b) of one particle is obtained from the theoretical mass and the number ratio of the particles belonging to each channel obtained earlier.

As described above, the theoretical specific surface area A (= a / b) of the toner mother particle is calculated from the average theoretical surface area and the average theoretical mass of one particle.

<< Measurement method of BET specific surface area B of toner matrix particles >>
The specific surface area BET of the toner matrix particles can be determined by a low temperature gas adsorption method based on a dynamic constant pressure method according to the BET method (preferably the BET multipoint method). For example, by using a specific surface area measuring device "Gemini 2375 Ver.5.0" (manufactured by Shimadzu Corporation) to adsorb nitrogen gas on the sample surface and measuring using the BET multipoint method, the BET specific surface area (BET specific surface area) m ² / g) was calculated. Specifically, the measurement is performed by the following procedure.

After measuring the mass of the empty sample cell, the sample cell is filled with 1.0 g of the measurement sample. Further, a sample cell filled with a sample is set in the degassing device, and degassing is performed at room temperature for 7 hours. After degassing, the mass of the entire sample cell is measured, and the exact mass of the sample is calculated from the difference from the empty sample cell. Next, empty sample cells are set in the balance port and analysis port of the BET measuring device. A Dewar bottle containing liquid nitrogen is set at a predetermined position, and P0 is measured by a saturated vapor pressure (P0) measurement command. After the P0 measurement is completed, the degassed sample cell is set in the analysis port, the sample mass and P0 are input, and then the measurement is started by the BET measurement command. After that, the BET specific surface area is automatically calculated.

<Measurement method of hydrophobicity of treated magnetic material>
The degree of hydrophobization of the treated magnetic material is obtained from the methanol dropping transmittance curve obtained as described below.

First, 70 ml of a hydrous methanol solution consisting of 40% by volume of methanol and 60% by volume of water is placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm in order to remove air bubbles and the like in the measurement sample. Disperse with an ultrasonic disperser for 5 minutes.

Next, the treated magnetic material is shaken with a mesh having an opening of 150 μm, 0.2 g of the treated magnetic material passed through the mesh is precisely weighed and added into a container containing the above-mentioned hydrous methanol solution, and a sample solution for measurement is added. Prepare.

Then, the sample liquid for measurement is set in the powder wettability tester "WET-100P" (manufactured by Reska). This measurement sample solution is stirred at a rate of ^{6.7 s -1 (400 rpm) using a magnetic stirrer.} As the rotor of the magnetic stirrer, a spindle-shaped rotor coated with a fluororesin and having a length of 25 mm and a maximum body diameter of 8 mm is used.

Next, the transmittance was measured with light having a wavelength of 780 nm while continuously adding methanol at a dropping rate of 1.3 ml / min into the sample liquid for measurement through the above apparatus, as shown in FIG. Create a methanol dropping permeability curve.

<Measurement method of toner average circularity and aspect ratio>
The average circularity of the toner and the aspect ratio of the toner are measured by the flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex) under the measurement and analysis conditions at the time of calibration work.

The specific measurement method is as follows.

First, about 20 ml of ion-exchanged water from which impure solids and the like have been removed in advance is placed in a glass container. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a precision measuring instrument with a pH of 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.2 ml of the diluted solution is added. Further, about 0.02 g of the measurement sample is added, and the dispersion treatment is performed for 2 minutes using an ultrasonic disperser to prepare a dispersion liquid for measurement. At that time, the dispersion liquid is appropriately cooled so that the temperature is 10 ° C. or higher and 40 ° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (for example, "VS-150" (manufactured by Vervocrea)) having an oscillation frequency of 50 kHz and an electrical output of 150 W is used, and a predetermined amount is contained in the water tank. Ion-exchanged water is added, and about 2 ml of the contaminanton N is added into the water tank.

For the measurement, the flow type particle image analyzer equipped with "LUCPLFLN" (magnification 20 times, numerical aperture 0.40) was used as the objective lens, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. To use. The dispersion liquid prepared according to the above procedure is introduced into the flow type particle image analyzer, and 2000 toners are measured in the total count mode in the HPF measurement mode. Then, the binarization threshold value at the time of particle analysis is set to 85%, the diameter of the analyzed particle is limited to 1.977 μm or more and less than 39.54 μm, and the average circularity and aspect ratio of the toner are obtained.

In the measurement, automatic focus adjustment is performed using standard latex particles (for example, "RESAARCH AND TEST PARTICLES Latex Microsphere Suspensions 5100A" manufactured by Duke Scientific Co., Ltd. diluted with ion-exchanged water) before the start of the measurement. After that, it is preferable to perform focus adjustment every 2 hours from the start of measurement.

In the embodiment of the present application, a flow-type particle image analyzer that has been calibrated by Sysmex and has been issued with a calibration certificate issued by Sysmex is used. The measurement is performed under the measurement and analysis conditions when the calibration certificate is obtained, except that the particle size to be analyzed is limited to a circle equivalent diameter of 1.977 μm or more and less than 39.54 μm.

<Measurement method of peak molecular weight Mp (P) of amorphous polyester>
The molecular weight distribution of the THF-soluble component of the amorphous polyester is measured by gel permeation chromatography (GPC) as follows.

First, the target sample is dissolved in tetrahydrofuran (THF) over 24 hours at room temperature. Then, the obtained solution is filtered through a solvent-resistant membrane filter "Maeshori Disc" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is about 0.8% by mass. This sample solution is used for measurement under the following conditions.
Equipment: HLC8120 GPC (Detector: RI) (manufactured by Tosoh Corporation)
Column: 7 series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: tetrahydrofuran (THF)
Flow velocity: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name "TSK standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-" 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) is used.

<Measurement method of 75% area ratio and domain area ratio>
After the toner is sufficiently dispersed in the visible light curable resin (Aronix LCR series D800), it is cured by irradiating it with short wavelength light. The obtained cured product is cut out with an ultramicrotome equipped with a diamond knife to prepare a flaky sample of 250 nm. Next, the cut-out sample was magnified using a transmission electron microscope (JEM-2800 manufactured by JEOL Ltd.) (TEM-EDX) at a magnification of 40,000 to 50,000 times, the cross section of the particles was observed, and the EDX was used. Perform element mapping.

The toner cross section to be observed is selected as follows. First, the cross-sectional area of the toner is obtained from the toner cross-sectional image, and the diameter of a circle having an area equal to the cross-sectional area (circle equivalent diameter) is obtained. Only the toner cross-sectional image in which the absolute value of the difference between the equivalent circle diameter and the weight average particle size (D4) of the toner is within 1.0 μm is observed.

As the mapping conditions, the storage rate is 9000 to 13000, and the number of integrations is 120 times. Among the resin-derived domains confirmed from the observation images, the spectral intensity derived from the C element and the spectral intensity derived from the O element are measured, and the domain in which the spectral intensity of the C element with respect to the O element is 0.05 or more is found. It is a domain of amorphous polyester. After identifying the domain of the amorphous polyester, the distance between the contour and the center point of the cross section from the contour of the toner cross section with respect to the total area of the domain of the amorphous polyester existing in the toner cross section by binarization treatment. Calculate the area ratio (area%) of the amorphous polyester domain present within 25% of the above. Image Pro PLUS (manufactured by Nippon Roper Co., Ltd.) is used for the binarization process.

The calculation method is as follows. In the above TEM image, the contour and center point of the toner cross section are obtained. The contour of the toner cross section shall be along the surface of the toner observed in the TEM image. The center point of the toner cross section is the center of gravity of the toner cross section.

From the obtained center point, a line is drawn with respect to a point on the contour of the toner cross section. On the line, the position of 75% of the distance between the contour and the center point of the cross section is specified from the contour.

Then, this operation is performed for one round of the contour of the toner cross section, and a boundary line of 75% of the distance between the contour and the center point of the cross section is clearly indicated from the contour of the toner cross section.

Based on the TEM image in which the 75% boundary line is clearly shown, the area of the domain of the amorphous polyester existing in the region surrounded by the contour of the cross section of the toner and the 75% boundary line is measured. .. Then, the total area of the amorphous polyester domain existing in the toner cross section is measured, and the area% based on the total area is calculated.

<Measuring method of number average particle size (D1) of amorphous polyester domains>
Element mapping is performed using EDX in the same manner as above to identify the amorphous polyester domain.

The average particle size of the number of domains is obtained by obtaining the equivalent circle diameter from the area of the domains. The number of measurements is 100, and the arithmetic mean value of the circle-equivalent diameter of 100 domains is defined as the number average particle diameter of the domains. The toner for which the average particle size of the number of domains is calculated is determined as follows.

First, the cross-sectional area of the toner is obtained from the toner cross-sectional image, and the diameter of a circle having an area equal to the cross-sectional area (circle equivalent diameter) is obtained. The domain diameter is calculated only for the toner cross-sectional image in which the absolute value of the difference between the equivalent circle diameter and the weight average particle diameter (D4) of the toner is 1.0 μm or less. Since the domain diameter may change depending on the particle size of the toner, the average domain diameter can be calculated by doing so.

<Measurement method of acid value Av of amorphous polyester>
The acid value is the number of mg of potassium hydroxide required to neutralize the acid contained in 1 g of the sample. The acid value of amorphous polyester is measured according to JIS K 0070-1992, but specifically, it is measured according to the following procedure.

(1) Preparation of Reagents 1.0 g of phenolphthalein is dissolved in 90 ml of ethyl alcohol (95% by volume), and ion-exchanged water is added to make 100 ml to obtain a phenolphthalein solution.

Dissolve 7 g of special grade potassium hydroxide in 5 ml of water and add ethyl alcohol (95% by volume) to make 1 L. Put it in an alkali-resistant container so as not to come into contact with carbon dioxide, leave it for 3 days, and then filter it to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution is stored in an alkali-resistant container. The factor of the potassium hydroxide solution was that 25 ml of 0.1 mol / l hydrochloric acid was placed in a triangular flask, several drops of the phenolphthaline solution were added, titrated with the potassium hydroxide solution, and the hydroxylation required for neutralization was performed. Obtained from the amount of potassium solution. As the 0.1 mol / l hydrochloric acid, those prepared according to JIS K 8001-1998 are used.

(2) Operation (A) Main test 2.0 g of a crushed amorphous polyester sample is precisely weighed in a 200 ml Erlenmeyer flask, 100 ml of a mixed solution of toluene / ethanol (2: 1) is added, and the mixture is dissolved over 5 hours. To do. Then, a few drops of the phenolphthalein solution are added as an indicator, and titration is performed using the potassium hydroxide solution. The end point of the titration is when the light red color of the indicator continues for about 30 seconds.

(B) Blank test Titration is performed in the same manner as described above except that a sample is not used (that is, only a mixed solution of toluene / ethanol (2: 1) is used).

(3) Substitute the obtained result into the following formula to calculate the acid value.
A = [(CB) x f x 5.61] / S
Here, A: acid value (mgKOH / g), B: addition amount of potassium hydroxide solution in blank test (ml), C: addition amount of potassium hydroxide solution in this test (ml), f: potassium hydroxide Solution factor, S: sample (g).

<Measurement method of hydroxyl value OHv of amorphous polyester>
The hydroxyl value is the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when acetylating 1 g of a sample. The hydroxyl value of the amorphous polyester is measured according to JIS K 0070-1992, but specifically, it is measured according to the following procedure.

(1) Preparation of Reagents 25 g of special grade acetic anhydride is placed in a 100 ml volumetric flask, pyridine is added to make the total volume 100 ml, and the mixture is sufficiently shaken to obtain an acetylation reagent. The obtained acetylation reagent is stored in a brown bottle so as not to come into contact with moisture, carbon dioxide, etc.

1.0 g of phenolphthalein is dissolved in 90 ml of ethyl alcohol (95% by volume), and ion-exchanged water is added to make 100 ml to obtain a phenolphthalein solution.

Dissolve 35 g of special grade potassium hydroxide in 20 ml of water and add ethyl alcohol (95% by volume) to make 1 L. Put it in an alkali-resistant container so as not to come into contact with carbon dioxide, leave it for 3 days, and then filter it to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution is stored in an alkali-resistant container. As for the factor of the potassium hydroxide solution, 25 ml of 0.5 mol / l hydrochloric acid was placed in a triangular flask, several drops of the phenolphthaline solution were added, titrated with the potassium hydroxide solution, and the hydroxylation required for neutralization was performed. Obtained from the amount of potassium solution. As the 0.5 mol / l hydrochloric acid, those prepared according to JIS K 8001-1998 are used.

(2) Operation (A) Main test 1.0 g of a crushed amorphous polyester sample is precisely weighed into a 200 ml round bottom flask, and 5.0 ml of the above acetylation reagent is accurately added to this using a whole pipette. At this time, if the sample is difficult to dissolve in the acetylation reagent, a small amount of special grade toluene is added to dissolve the sample.

A small funnel is placed on the mouth of the flask, and about 1 cm of the bottom of the flask is immersed in a glycerin bath at about 97 ° C. and heated. At this time, in order to prevent the temperature of the neck of the flask from rising due to the heat of the bath, it is preferable to cover the base of the neck of the flask with thick paper having a round hole.

After 1 hour, remove the flask from the glycerin bath and allow to cool. After allowing to cool, add 1 ml of water from the funnel and shake to hydrolyze acetic anhydride. The flask is heated again in a glycerin bath for 10 minutes for further complete hydrolysis. After allowing to cool, wash the walls of the funnel and flask with 5 ml of ethyl alcohol.

A few drops of the phenolphthalein solution are added as an indicator and titrated with the potassium hydroxide solution. The end point of the titration is when the light red color of the indicator continues for about 30 seconds.

(B) Blank test Titration is performed in the same manner as described above except that an amorphous polyester sample is not used.
(3) Substitute the obtained result into the following formula to calculate the hydroxyl value.
A = [{(BC) x 28.05 x f} / S] + D
Here, A: hydroxyl value (mgKOH / g), B: addition amount of potassium hydroxide solution in blank test (ml), C: addition amount of potassium hydroxide solution in this test (ml), f: potassium hydroxide Solution factor, S: sample (g), D: acid value of amorphous polyester (mgKOH / g).

<Measurement of interfacial tension of the amorphous polyester dissolved in styrene / butyl acrylate = 80/20 (weight ratio) in a tricalcium phosphate aqueous solution having a pH of 6.0 by the suspension method>
(1) After warming to put to 60 ° C. 0.1 mol / L-Na ₃ PO ₄ aqueous solution 450 parts to 720 parts Preparation of ion-exchanged water of the aqueous phase, 1.0 mol / L-CaCl ₂ aqueous solution 67 . Add 7 parts to obtain an aqueous medium containing a dispersion stabilizer. Measure the pH (hereinafter also referred to as the aqueous phase) and confirm that it is 6.0 ± 0.2.

(2) Preparation of oil phase 1 g of a sample is added to 8 g of styrene and 2 g of n-butyl acrylate and dissolved to prepare a styrene / butyl acrylate dispersion (hereinafter, also referred to as an oil phase).

(3) Interfacial tension measurement The interfacial tension was measured by the suspension method described below. Specifically, in an environment of a temperature of 25 ° C., a FACE solid-liquid interface analyzer Drop Master 700 manufactured by Kyowa Interface Science Co., Ltd. was used, and the measurement was performed with WIDE1 as the field of view of the lens portion. First, the tip of a thin tube having an inner diameter of 0.4 mm is inserted into the aqueous phase downward in the vertical direction. Next, the thin tube is connected to the syringe section. A pre-prepared oil phase is placed in the syringe section. Next, by connecting the syringe part to AUTO DISPENSER AD-31 manufactured by Kyowa Interface Science Co., Ltd. and extruding the oil phase from the thin tube, droplets can be created at the tip of the thin tube in the aqueous phase. Then, the interfacial tension is calculated from the shape of the droplet. The control and calculation methods for creating droplets were performed using a measurement and analysis system manufactured by Kyowa Interface Science Co., Ltd. The density difference between the aqueous phase and the oil phase required for the calculation was 0.10 g / cm3, which is the density difference between water and styrene. The final measurement result of the interfacial tension was the average value of the measured values of 10 times.

Although the basic configuration and features of the present invention have been described above, the present invention will be specifically described below based on Examples. However, this does not limit any embodiment of the present invention. The number of copies in the examples is based on mass unless otherwise specified.

<Preparation of toner carrier 1>
(Preparation of substrate 1)
As the substrate 1, a core metal having a diameter of 6 mm made of SUS304 was coated with a primer (trade name, DY35-051; manufactured by Toray Dow Corning) and baked.

(Manufacturing of elastic roller 1)
The substrate 1 prepared as described above was placed in a mold, and an addition type silicone rubber composition mixed with the following materials was injected into a cavity formed in the mold.
-Liquid silicone rubber material (trade name, SE6724A / B; manufactured by Toray Dow Corning)
100 copies, carbon black (trade name, Talker Black # 4300; manufactured by Tokai Carbon Co., Ltd.)
15 parts ・ Silica particles as heat resistance imparting agent 0.2 parts ・ Platinum catalyst 0.1 parts

Subsequently, the mold was heated and the silicone rubber was vulcanized and cured at a temperature of 150 ° C. for 15 minutes. After the substrate 1 having the cured silicone rubber layer formed on the peripheral surface was removed from the mold, the substrate 1 was further heated at a temperature of 180 ° C. for 1 hour to complete the curing reaction of the silicone rubber layer. In this way, an elastic roller 1 having a silicone rubber elastic layer having a diameter of 12 mm formed so as to cover the outer peripheral surface of the substrate was produced.

(Preparation of surface layer 1)
(Synthesis of isocyanate group-terminated prepolymer 1)
Polypropylene glycol-based polyol (trade name: Excelol 4030; manufactured by Asahi Glass Co., Ltd.) 100 with respect to 17.7 parts of toluene diisocyanate (TDI) (trade name: Cosmonate T80; manufactured by Mitsui Chemicals, Inc.) in a nitrogen atmosphere. 0.0 g was gradually added dropwise while maintaining the temperature in the reaction vessel at 65 ° C. After completion of the dropping, the reaction was carried out at a temperature of 65 ° C. for 2 hours. The obtained reaction mixture was cooled to room temperature to obtain an isocyanate group-terminated prepolymer 1 having an isocyanate group content of 3.8% by mass.

(Synthesis of Amino Compound 1)
In a reaction vessel equipped with a stirrer, a thermometer, a perfusion tube, a dropping device and a temperature controller, 100.0 parts (1.67 mol) of ethylenediamine and 100 parts of pure water were heated to 40 ° C. while stirring. Next, 425.3 parts (7.35 mol) of propylene oxide was gradually added dropwise over 30 minutes while maintaining the reaction temperature at 40 ° C. or lower. The reaction was carried out with stirring for another hour to obtain a reaction mixture. The obtained reaction mixture was heated under reduced pressure to distill off water to obtain 1: 426 g of an amino compound.

As a surface layer material
-Isocyanate group-terminated prepolymer 1 617.9 parts-Amino compound 1 34.2 parts-Carbon black (trade name, MA230; manufactured by Mitsubishi Chemical Co., Ltd.) 117.4 parts-Urethane resin fine particles (trade name, Artpearl C-400) ; Made by Negami Kogyo Co., Ltd.)
130.4 parts were stirred and mixed.

Next, methyl ethyl ketone (hereinafter, also referred to as “MEK”) was added so that the total solid content ratio was 30% by mass, and then the mixture was mixed by a sand mill. Then, the viscosity was further adjusted to 10 cps or more and 13 cps or less with MEK to prepare a coating material for forming a surface layer.

The elastic roller 1 produced earlier was immersed in a paint for forming a surface layer to form a coating film of the paint on the surface of the elastic layer of the elastic roller 1 and dried. Further, a surface layer having a film thickness of 15 μm was provided on the outer periphery of the elastic layer by heat treatment at a temperature of 150 ° C. for 1 hour to prepare a toner carrier 1.

<Production example of long-chain monomer 1>
1200 g of an aliphatic hydrocarbon having a peak carbon number of 35 was placed in a cylindrical reaction vessel made of glass, 38.5 g of boric acid was added at a temperature of 140 ° C., and immediately, the oxygen concentration of 50% by volume of air and 50% by volume of nitrogen was about. A mixed gas of 10% by volume is blown at a rate of 20 liters per minute, reacted at 200 ° C. for 3.0 hours, then warm water is added to the reaction solution, and hydrolysis is carried out at 95 ° C. for 2 hours. The reaction was taken. 20 parts of the modified product was added to 100 parts of n-hexane to dissolve and remove the unmodified component to obtain a long-chain monomer 1. The obtained long-chain monomer 1 had a denaturation rate of 94% and a hydroxyl value of 92.4 mgKOH / g.

<Production example of amorphous polyester APES1>
A carboxylic acid component and an alcohol component are adjusted as raw material monomers as shown in Table 1 in a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and then dibutyltin is used as a catalyst. Add 1.5 parts to a total of 100 parts. Then, after rapidly raising the temperature to 180 ° C. under normal pressure under a nitrogen atmosphere, water was distilled off while heating at a rate of 10 ° C./hour from 180 ° C. to 210 ° C. to carry out polycondensation. After reaching 210 ° C., the inside of the reaction vessel was depressurized to 5 kPa or less, and polycondensation was carried out under the conditions of 210 ° C. and 5 kPa or less to obtain amorphous polyester APES1. At that time, the polymerization time was adjusted so that the peak molecular weight of the obtained amorphous polyester APES1 would be the value shown in Table 1. The physical characteristics of the amorphous polyester APES1 are shown in Table 1.

<Manufacturing of amorphous polyester APES2-19>
Amorphous polyester APES2-19 was obtained in the same manner as amorphous polyester APES1 except that the raw material monomer and the amount used were changed as shown in Table 1. The physical characteristics of these amorphous polyesters are shown in Table 1.

<Production example of amorphous polyester (APES20)>
100 g of bisphenol A ethylene oxide 2 mol additive, 189 g of bisphenol A propylene oxide 2 mol additive, 51 g of terephthalic acid, 61 g of fumaric acid, adipine in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple. 25 g of acid and 2 g of esterification catalyst (tin octylate) were added and subjected to a shrink polymerization reaction at 230 ° C. for 8 hours, further reacted at 8 kPa for 1 hour, cooled to 160 ° C., and then 6 g of acrylic acid, 70 g of styrene, and n-. A mixture of 31 g of butyl acrylate and 20 g of a polymerization initiator (di-t-butyl peroxide) was added dropwise over 1 hour using a dropping funnel, and after the addition, the addition polymerization reaction was continued for 1 hour while maintaining the temperature at 160 ° C. , 200 ° C., held at 10 kPa for 1 hour, and then the unreacted acrylic acid, styrene and butyl acrylate are removed to form a composite resin in which the vinyl polymerized segment and the polyester polymerized segment are bonded. Acrylic polyester (APES20) was obtained.

<Production example of processed magnetic material 1>
In ferrous sulfate aqueous solution, 1.00 to 1.10 equivalents of caustic soda solution with respect to iron element, P ₂ O ₅ with an amount of 0.15% by mass in terms of phosphorus element with respect to iron element, and 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 set to 8.0, and an oxidation reaction was carried out at 85 ° C. while blowing air to prepare a slurry liquid having seed crystals.

Next, ferrous sulfate aqueous solution was added to this slurry liquid so that the amount was 0.90 to 1.20 equivalents with respect to the initial alkali amount (sodium component of caustic soda), the slurry liquid was maintained at pH 7.6, and air was introduced. The oxidation reaction was promoted while blowing to obtain a slurry liquid containing magnetic iron oxide. After filtering and washing, the hydrous slurry liquid is once taken out. At this time, a small amount of a water content sample is taken and the water content is measured. Next, this water-containing sample was put into another aqueous medium without being dried, and the slurry was redispersed with a pin mill while being stirred and the slurry was circulated to adjust the pH of the redispersion solution to about 4.8. Then, while stirring, 1.6 parts of the n-hexyltrimethoxysilane coupling agent was added to 100 parts of magnetic iron oxide (the amount of magnetic iron oxide was calculated as the value obtained by subtracting the water content from the water content sample), and water was added. Disassembly was performed. After that, the mixture is sufficiently stirred to adjust the pH of the dispersion liquid to 8.6 and surface treatment is performed. 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 90 ° C. for 30 minutes, and the obtained particles are crushed to have a volume average particle size of 0. A processed magnetic material 1 having a thickness of .21 μm was obtained.

<Manufacturing examples of treated magnetic materials 2 and 3>
The treated magnetic materials 2 and 3 were obtained in the same manner as the treated magnetic material 1 except that the amount of the n-hexyltrimethoxysilane coupling agent was changed. Table 2 shows the physical characteristics of the treated magnetic materials 1 to 3.

<Production example of toner mother particle 1>
(Preparation of first aqueous medium)
After warming to 0.1mol / L-Na ₃ PO ₄ is turned to a temperature 60 ° C. The aqueous solution of 450 parts of 720 parts of deionized water, the dispersion stability by adding 1.0mol / L-CaCl ₂ aqueous solution 67.7 parts A first aqueous medium containing the agent was obtained.

(Preparation of polymerizable monomer composition)
・ Styrene 74 parts ・ n-butyl acrylate 26 parts ・ Divinylbenzene 0.5 parts ・ Amorphous polyester resin 110 parts ・ Load electric control agent T-77 (manufactured by Hodogaya Chemical Co., Ltd.) 1 part ・ Processed magnetic material 1 65 parts The formulation is uniformly dispersed and mixed using an Attritor (manufactured by Mitsui Miike Machinery Co., Ltd.). This monomer composition is heated to a temperature of 60 ° C., and 15 parts of paraffin wax (HNP-9: manufactured by Nippon Seiwa Co., Ltd.) is added thereto as a release agent, and t-butyl peroxypi is used as a polymerization initiator. 7 parts of paraffin (25% toluene solution) was mixed / dissolved to obtain a polymerizable monomer composition.

(Preparation of second aqueous medium)
150 parts of 0.1 mol / L-Na ₃ PO ₄ aqueous solution was added to 360 parts of ion-exchanged water and heated to a temperature of 60 ° C., and then _{22.6 parts of 1.0 mol / L-CaCl 2} aqueous solution was added to stabilize the dispersion. A second aqueous medium containing the agent was obtained.

(Granulation / Polymerization / Filtration / Drying)
The polymerizable monomer composition was introduced into the first aqueous medium, temperature 60 ° C., T. under N ₂ atmosphere K. Granulate by stirring with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 10,000 rpm for 15 minutes. Then, the granulation liquid is added to the second aqueous medium, stirred with a paddle stirring blade, and the polymerization reaction is carried out at a reaction temperature of 70 ° C. for 300 minutes.

At this point, hydrochloric acid was added to a small amount of sampled aqueous medium to wash and remove calcium phosphate, and then the particles were filtered and dried to analyze the colored particles. As a result, the glass transition temperature Tg of the binder resin was 54 ° C.

Subsequently, the water-based medium in which the colored particles are dispersed is heated to 100 ° C. and held for 120 minutes. Then, 5 ° C. water is added to the water-based medium, and the mixture is cooled from 100 ° C. to 50 ° C. at a cooling rate of 300 ° C./min. Subsequently, the aqueous medium was held at 50 ° C. for 120 minutes.

Then, hydrochloric acid was added to the aqueous medium to wash and remove calcium phosphate, and then the mixture was filtered and dried to obtain toner matrix particles 1. Table 3 shows the production conditions of the toner mother particles 1.

<Production example of toner matrix particles 2-29>
In the production of the toner matrix particles 1, except that the seeds of the amorphous polyester, the amount added, the seeds of the colorant, the amount added, the amount of the dispersion stabilizer in the second aqueous medium, the amount of sodium chloride, and the production conditions are changed. In the same manner, toner mother particles 2-29 were produced. Table 3 shows the production conditions of the obtained toner matrix particles.

<Production example of toner matrix particles 30>
<< Preparation of each dispersion >>
-Resin particle dispersion liquid (1)-
・ Styrene (manufactured by Wako Junyaku Co., Ltd.): 325 parts ・ n Butyl acrylate (manufactured by Wako Junyaku Co., Ltd.): 100 parts Nakamura Kagaku Co., Ltd.): 1.5 parts, Dodecanethiol (Wako Junyaku Co., Ltd.): 3.0 parts The above components are mixed in advance and dissolved to prepare a solution, and an anionic surfactant (Dow Chemical). A surfactant solution prepared by dissolving 9 parts of Doufax A211) in 580 parts of ion-exchanged water is contained in a flask, and 400 parts of the above solution is added to disperse and emulsify, and the mixture is slowly stirred for 10 minutes. While mixing, 50 parts of ion-exchanged water in which 6 parts of ammonium persulfate was dissolved was added.

Next, after the inside of the flask was sufficiently replaced with nitrogen, the inside of the flask was heated with an oil bath while stirring until the inside of the flask reached 75 ° C., and emulsion polymerization was continued as it was for 5 hours to obtain a resin particle dispersion liquid (1). It was.

When the physical properties of the resin particles were examined by separating the resin particles from the resin particle dispersion liquid (1), the number average particle size was 195 nm, the solid content in the dispersion liquid was 42%, the glass transition point was 51.5 ° C., and the weight average molecular weight Mw. Was 32000.

-Resin particle dispersion liquid (2)-
The amorphous polyester (APES20) was dispersed using a disperser obtained by modifying Cavitron CD1010 (manufactured by Eurotec Ltd.) into a high-temperature and high-pressure type. Specifically, the composition ratio is 79% of ion-exchanged water, 1% of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) (as an active ingredient), and 20% of amorphous polyester 20. Then, the pH was adjusted to 8.5 with ammonia, the Cavitron was operated under the conditions of a rotor rotation speed of 60 Hz, a pressure of 5 kg / cm ² , and heating by a heat exchanger at 140 ° C., and the number average particle size was 200 nm. Resin fine particle dispersion liquid (2) was obtained.

-Colorant dispersion-
-Carbon black 20 parts-Anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts-Ion-exchanged water 78 parts-The above components are homogenized at 3000 rpm using a homogenizer (Ultratarax T50, manufactured by IKA). Soak the pigment in water for 2 minutes, disperse it at 5000 rpm for 10 minutes, stir it with a normal stirrer for 1 day and night to defoam, and then use the high-pressure impact disperser Ultimateizer Co., Ltd., Sugino Machine Co., Ltd. Using HJP30006), the mixture was dispersed at a pressure of 240 MPa for about 1 hour to obtain a colorant dispersion liquid (1). Further, the pH of the dispersion was adjusted to 6.5.

-Release release agent dispersion-
-45 parts of hydrocarbon wax (Fischer-Tropsch wax, maximum endothermic peak = 78 ° C, Mw = 750)
・ Cationic surfactant (Neogen RK, Dai-ichi Kogyo Seiyaku) 5 parts ・ Ion-exchanged water 200 parts Heat the above components to 95 ° C and disperse them sufficiently with a homogenizer (Ultratarax T50 manufactured by IKA). Dispersion treatment was carried out with a pressure discharge type golin homogenizer to obtain a release agent dispersion having an average number diameter of 190 nm and a solid content of 25%.

<< Production Example of Toner Mother Particle 28 >>
-Ion-exchanged water 400 parts-Resin particle dispersion liquid (1) 620 parts (resin particle concentration: 42%)
-Resin particle dispersion liquid (2) 279 parts (resin particle concentration: 20%)
-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount: 60%)
1.5 parts (0.9 parts as active ingredient)
The above components were placed in a 3 liter reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and kept at a temperature of 30 ° C. and a stirring rotation speed of 150 rpm for 30 minutes while controlling the temperature from the outside with a mantle heater. Then, 88 parts of the colorant dispersion liquid and 60 parts of the release agent dispersion liquid were added and held for 5 minutes. As it was, a 1.0% aqueous nitric acid solution was added to adjust the pH to 3.0. Next, the stirrer and mantle heater were removed, and while dispersing at 3000 rpm with a homogenizer (manufactured by IKA Japan: Ultratarax T50), 0.33 parts of polyaluminum chloride and 37.5 parts of 0.1% nitric acid aqueous solution were added. After adding 1/2 of the mixed solution, the dispersion speed was set to 5000 rpm, the remaining 1/2 was added over 1 minute, and the dispersion speed was set to 6500 rpm for 6 minutes.

A stirrer and a mantle heater are installed in the reaction vessel, and the temperature is raised to 42 ° C. at 0.5 ° C./min while appropriately adjusting the rotation speed of the stirrer so that the slurry is sufficiently agitated, and at 42 ° C. After holding for 15 minutes, the particle size was measured with a Coulter Multisizer every 10 minutes while raising the temperature at 0.05 ° C./min, and when the weight average particle size was 7.8 μm, 5% water was used. The pH was adjusted to 9.0 using an aqueous sodium oxide solution. Then, while adjusting the pH to 9.0 every 5 ° C., the temperature was raised to 96 ° C. at a heating rate of 1 ° C./min and maintained at 96 ° C. When the particle shape and surface properties were observed with an optical microscope and a scanning electron microscope (FE-SEM) every 30 minutes, the particles became almost spherical in the second hour, so the temperature was lowered to 20 ° C. at 1 ° C./min to cool the particles. Solidified.

After that, the reaction product is filtered and washed with ion-exchanged water, and when the conductivity of the filtrate becomes 50 mS or less, the cake-shaped particles are taken out and the amount of ion-exchanged water is 10 times the particle weight. The particles were charged, stirred with a three-one motor, and when the particles were sufficiently loosened, the pH was adjusted to 3.8 with a 1.0% aqueous nitrate solution and held for 10 minutes. After that, it was filtered and washed with water again, and when the conductivity of the filtrate became 10 mS or less, the water flow was stopped and solid-liquid separation was performed. The obtained cake-like particles were crushed with a sample mill and dried in an oven at 40 ° C. for 24 hours. Further, the obtained powder was crushed by a sample mill and then vacuum dried in an oven at 40 ° C. for 5 hours to obtain toner matrix particles 30.

<Production example of toner matrix particles 31>
Toner mother particles were produced according to Example 2 of Japanese Patent No. 4485382 to obtain toner mother particles 31.

<Production example of toner matrix particles 32>
Toner mother particles were produced according to Example 1 of JP-A-2005-184746 to obtain toner mother particles 32.

[Example 1]
<Making toner>
<Manufacturing example of toner 1>
To 100 parts of the toner mother particles 1, 0.3 parts of sol-gel silica fine particles having an average particle size of 115 nm were added, and mixed using a Mitsui Henchel Mixer (manufactured by Mitsui Miike Machinery Co., Ltd.). After that, silica having an average number of primary particles with an average particle size of 12 nm was treated with hexamethyldisilazane and then treated with silicone oil, and 0.9 parts of hydrophobic silica fine particles ^{having a BET specific surface area value of 120 m 2 / g after the treatment.} Was added and mixed in the same manner using Mitsui Henchel Mixer (manufactured by Mitsui Miike Machinery Co., Ltd.) to prepare toner 1. Table 4 shows the physical characteristics of the toner 1.

<Image forming device>
The Canon printer LBP7700C was modified and used for image output evaluation. As a modification point, the toner carrier is changed to the toner carrier 1, the toner supply member of the developing device is rotated in the opposite direction to the toner carrier as shown in FIG. 1, and a voltage is applied to the toner supply member. Turn off. The contact pressure is adjusted so that the width of the contact portion between the toner carrier and the electrostatic latent image carrier is 1.0 mm.

In addition, the cleaning blade is removed, and the process speed is modified to 35 ppm. In this way, the area of the contact portion between the toner carrier and the electrostatic latent image carrier is reduced, and the process speed is increased, so that strict image formation conditions are obtained. In addition, the structure of the fuser was modified so that no voltage was applied to the fixing film during fixing. This makes it possible to see the electrostatic offset strictly.

The developing device modified as described above is filled with 100 g of toner 1 and repeated in a low temperature and low humidity environment (15.0 ° C./10.0%) and a high temperature and high humidity environment (32.5 ° C./80% RH). Perform a usage test. As an output image for the repeated use test, a horizontal line image having a printing rate of 1% is printed on two sheets of intermittent paper, 1000 sheets a day, for a total of 4000 sheets (4 days). The evaluation results are shown in Table 5. As an evaluation paper used for the repeated use test, a business 4200 (manufactured by Xerox) having a ^{basis weight of 75 g / m 2 is used.}

The evaluation method of each evaluation performed in the examples and comparative examples of the present invention and the judgment criteria thereof will be described below.

<Fog on the black drum in a low temperature and low humidity environment>
The fog is measured using a REFLECTMER MODEL TC-6DS manufactured by Tokyo Denshoku Co., Ltd. A green filter is used as the filter. "Fog on the black back drum" outputs a solid black image immediately after printing 4000 sheets of the above repeated use test, and covers the area of the photoconductor drum corresponding to the white background (non-image part) immediately after the transfer of the solid black image. I taped it with mylar tape, peeled it off, and stuck mylar tape on the paper. The difference is calculated by subtracting the reflectance of the stripped Mylar tape pasted on the unused paper from the reflectance of the stripped Mylar tape pasted on the unused paper.

In the present invention, C or higher was judged to be good.
A: Less than 5.0% B: 5.0% or more and less than 10.0% C: 10.0% or more and less than 15.0% D: 15.0% or more

<Evaluation of electrostatic offset resistance in low temperature and low humidity environment>
After printing 4000 sheets of the repeated use test and evaluating fog after black, the first half of the image is a solid black image, and the second half is a white background, and 100 sheets are continuously printed using the electrostatic offset test chart. , Visually evaluate the electrostatic offset resistance. The evaluation criteria for electrostatic offset resistance are defined as follows.
A: I can't see it at all.
B: It is faintly seen in the white part.
C: Seen in the white part.
D: Clearly seen in the white part.

<Fog on the drum after white in a high temperature and high humidity environment>
The fog is measured using a REFLECTMER MODEL TC-6DS manufactured by Tokyo Denshoku Co., Ltd. A green filter is used as the filter. "Fog on the black back drum" outputs a solid white image the next morning after printing 4000 sheets of the above repeated use test, and the area of the photoconductor drum corresponding to the white background part (non-image part) immediately after the transfer of the solid white image. Was taped with mylar tape, peeled off, and mylar tape was pasted on the paper. The difference is calculated by subtracting the reflectance of the stripped Mylar tape pasted on the unused paper from the reflectance of the stripped Mylar tape pasted on the unused paper.

In the present invention, C or higher was judged to be good.
A: Less than 5.0% B: 5.0% or more and less than 10.0% C: 10.0% or more and less than 15.0% D: 15.0% or more

<Pollution of charged rollers in a high temperature and high humidity environment>
During the repeated use test of 4000 sheets in a high temperature and high humidity environment, the state of the surface of the charging roller is visually observed every 1000 sheets (1 day). After that, the electrostatic latent image carrier is replaced with a new one, a halftone image is output, and the image is visually evaluated according to the following criteria.
A: No defects are found on the surface or image of the roller.
B: Some stains are found on the surface of the roller the next morning after printing 4000 sheets, but no defects are found in the halftone image output at that time.
C: Some stains were observed on the surface of the roller the next morning after printing 3000 sheets, and the halftone image output at that time had some density unevenness.
D: Some stains were observed on the surface of the roller the next morning after printing 3000 sheets, and the density unevenness was conspicuous in the halftone image output at that time.

[Examples 2-27]
In the production example of the toner 1, the toner mother particles are changed as shown in Table 4 to obtain toners 2 to 27. Table 4 shows the physical characteristics of each toner. Table 5 shows the evaluation results performed in the same manner as in Example 1.

[Comparative Examples 1 to 5]
In the production example of the toner 1, the toner mother particles are changed as shown in Table 4 to obtain toners 28 to 32. Table 4 shows the physical characteristics of each toner. Table 5 shows the evaluation results performed in the same manner as in Example 1.

45 Electrostatic image carrier, 46 Charging roller, 47 Toner carrier, 48 Toner supply member, 49 Developer, 50 Transfer member (transfer roller), 51 Fixer, 52 Pickup roller, 53 Transfer material (paper), 54 Laser generator, 55 toner control member, 56 metal plate, 57 toner

Claims (8)

A toner having toner matrix particles containing a binder resin, an amorphous polyester, and a colorant.
The binding resin contains a vinyl resin and
The toner has an average circularity of 0.960 or more and has an average circularity of 0.960 or more.
In the cross section of the toner observed with a transmission electron microscope, the vinyl resin forms a matrix, the amorphous polyester forms a domain, and the domain of the amorphous polyester is formed from the outline of the cross section. Within 75% of the distance between the contour and the center point of the cross section, 96 area% or more is present based on the total area of the domain.
The average of the scanning electron microscope (SEM) binarization is that the white area percentage obtained by from the toner mother particles observed under the following conditions in is not more than 10.0%,
The toner base particles of number-based particle size distribution and the true density obtained from the theoretical specific surface area A (m ² / g), and the specific surface area B, as measured by the BET method (m ² / g), the following equation ( Satisfy 1) and (2) ,
0.450 ≤ B ≤ 1.500 ... (1)
1.23 ≤ B / A ≤ 1.60 ... (2)
Toner characterized by that.
・ Conditions for calculating the white area ratio [Shooting conditions]
Scanning electron microscope: S-4800
Shooting magnification: 2000 times Shooting image: SE image Acceleration voltage: 2.0 kV
Acceleration current: 10.0 μA
Probe current: Normal
Focus mode: UHR
WD: 5.0 mm
[Area ratio measurement conditions]
Image processing software: Using Image J, the background of the captured image is completely blackened and then binarized, and the white area ratio in 50% square of the particle size is calculated centering on the center of gravity of the toner. The toner according to claim 1, wherein the toner has an aspect ratio of 0.910 or more. The amorphous polyester, styrene / butyl acrylate = 80/20 interfacial tension at tricalcium phosphate in an aqueous solution of pH6 of the amorphous polyester dissolved in (mass ratio) is 25 mN / m or more 35 mN / m or less the toner according to claim 1 or 2 is. The relationship between the amorphous polyester of acid value Av (mg KOH / g) and a hydroxyl value OHv (mg KOH / g) satisfies the following formula (3) and (4),
1.0 ≤ Av ≤ 4.0 ... (3)
2.0 ≤ Av + 0.1 OHv ≤ 8.0 ... (4)
The toner according to any one of claims 1 to 3. The amorphous polyester, according to have an alcohol component, a carboxylic acid component carbon atoms containing 6 to 12 of the linear aliphatic dicarboxylic acids or less 10 mol% or more 70 mol%, the polycondensation polymer Item 2. The toner according to any one of Items 1 to 4. The toner according to claim 1 having the amorphous polyester of 30.0 parts by mass 5.0 parts by mass or more with respect to 100 parts by weight of the binder resin. The toner according to any one of claims 1 to 6, wherein the toner mother particles contain magnetic fine particles. In the toner of the section observed by a transmission electron microscope, before Kihi-crystalline number average particle size of the polyester domains, in any one of claim 1 to 7 at 0.3μm or more 3.0μm or less The toner described.

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