JP2021047317A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming device, and image forming method - Google Patents

Abstract

To provide a toner for an electrostatic charge image development, which is excellent in fog suppressing properties in an obtained image.SOLUTION: A toner for an electrostatic charge image development contains toner particles and an external additive. Under the condition of 28°C and 85% RH, a ratio of a specific dielectric loss factor E1 at 100 Hz of the toner to a specific dielectric loss factor E2 at 1 kHz satisfies 1.10≤E2/E1≤1.80, and under the condition of 10°C and 15% RH, the ratio of a specific dielectric loss factor E3 at 1 kHz of the toner to the E2 satisfies 1.0≤E3/E2≤1.5.SELECTED DRAWING: None

Description

The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developing agent, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

Methods for visualizing image information via electrostatic charge images, such as electrophotographic methods, are currently used in various fields.
Conventionally, in the electrophotographic method, an electrostatic latent image is formed on a photoconductor or an electrostatic recorder by various means, and electrostatic detection particles called toner are attached to the electrostatic latent image to generate static electricity. A method of visualizing a latent image (toner image) through a plurality of steps of developing it, transferring it to the surface of the object to be transferred, and fixing it by heating or the like is generally used.

As a conventional image forming method, the one described in Patent Document 1 is known.
Patent Document 1 describes a charging step of charging an electrostatic latent image carrier, a developing step of developing with toner on a toner carrier to form a toner image on the surface of the electrostatic latent image carrier, and the toner. An image forming method including a transfer step of transferring an image to a transfer material, wherein the development step is a step of recovering toner remaining on the electrostatic latent image carrier with the toner carrier after the transfer step. The difference (| Vdc-Vd |) between the development potential Vdc at the time of development and the latent image potential Vd in the non-latent region is 350 V or more, and the toner is a toner containing a binder resin and a colorant. The electrical conductivity of the filtrate of the toner dispersion liquid having particles and dispersing the toner in ion-exchanged water so as to have a solid content concentration of 5.0% by mass is 2.0 μS / cm or more and 6.0 μS / cm or less. The image forming method is disclosed, wherein the dielectric loss rate (ε) of the toner at a frequency of 10 kHz and a temperature of 40 ° C. is 0.05 pF / m or more and 0.25 pF / m or less.

Further, as a conventional toner, those described in Patent Document 2 or Patent Document 3 are known.
Patent Document 2 contains capsule-type toner particles having a surface layer (B) on the surface of toner mother particles (A) containing at least a resin (a) containing polyester as a main component, a magnetic substance, and wax. In the toner, the surface layer (B) contains a resin (b), and the resin (b) contains a resin selected from a polyester resin (b1), a vinyl resin (b2), or a urethane resin (b3). The glass transition temperature Tg (a) of the resin (a) and the glass transition temperature Tg (b) of the resin (b) satisfy the relationship of the following formula (1).
Tg (a) <Tg (b) ... (1)
The magnetization (σt) of the toner in an external magnetic field of 79.6 kA / m is 12 Am ² / kg or more and 30 Am ² / kg or less, and the average circularity of the toner is 0.960 or more and 1.000 or less. Toners characterized by the above are disclosed.

In Patent Document 3, in a toner having toner particles containing at least a binder resin, carbon black, and a mold release agent, the weight average particle diameter of the toner particles is 3.5 to 8.0 μm, and the toner has a weight average particle size of 3.5 to 8.0 μm. The sum of the acid value and the OH value is 30 to 75 mgKOH / g, and the average circularity of the particles contained in the toner having a circle equivalent diameter of 2 μm or more is 0.915 or more and 0.960 or less, and the dielectric is dielectric. in the loss tangent tanδ of frequency 10 ³ to ¹⁰ 4 Hz range of toner indicated by the loss factor epsilon / dielectric constant epsilon,
tan δ (10 ³ to 10 ⁴ Hz) ≤ 0.0060
, And the frequency 5 × ¹⁰ 4 Hz and the ratio is 1.05 ≦ tanδ ⁽¹⁰ 5 Hz) and a loss tangent tan [delta between the frequency ^{10 5 Hz / tanδ (5 ×} 10 4 Hz) ≦ 1.40
A black toner characterized by the above is described.

JP-A-2018-173574 Japanese Unexamined Patent Publication No. 2009-098257 Japanese Unexamined Patent Publication No. 2004-078206

The problem to be solved by the present invention is that the ratio (E2 / E1) of the 100 Hz specific dielectric loss ratio E1 of the toner to the 1 kHz specific dielectric loss ratio E2 under the condition of 28 ° C. and 85% RH is less than 1.10 or It is obtained as compared with the case where the ratio (E3 / E2) of the 1 kHz specific dielectric loss ratio E3 of the toner to the E2 is more than 1.80 or under the condition of 10 ° C. and 15% RH. It is an object of the present invention to provide a toner for developing an electrostatic charge image having excellent fog suppression property in an image.

Specific means for solving the above problems include the following aspects.
<1> The ratio of the specific dielectric loss ratio E1 of 100 Hz to the specific dielectric loss ratio E2 of 1 kHz of the toner containing toner particles and an external additive under the condition of 28 ° C. and 85% RH is 1.10 ≦ E2 /. Static charge image development that satisfies E1 ≦ 1.80 and the ratio of the specific dielectric loss ratio E3 of 1 kHz of the toner to E2 under the condition of 10 ° C. and 15% RH is 1.0 ≦ E3 / E2 ≦ 1.5. Toner for.
<2> The toner for electrostatic charge image development according to <1>, wherein the coverage of the external additive is 40 area% or more and 70 area% or less on the surface of the toner particles.
<3> The toner for developing an electrostatic charge image according to <1> or <2>, wherein the external additive contains at least two types of particles.
<4> The toner for developing an electrostatic charge image according to any one of <1> to <3>, wherein the external additive contains particles having a water content of 0.01% by mass or less.
<5> The toner for static charge image development according to <4>, wherein the particles having a water content of 0.01% by mass or less are silica particles.
<6> The toner for static charge image development according to any one of <1> to <5>, wherein the external additive contains particles having a volume resistance of 10 ^{12 Ω · cm or more.}
<7> The toner for static charge image development according to any one of <1> to <6>, wherein the external additive contains two types of particles having a volume average particle diameter of 40 nm or more and 100 nm or less.
<8> The toner for static charge image development according to any one of <1> to <7>, which satisfies 1.15 ≦ E2 / E1 ≦ 1.65.
<9> The toner for static charge image development according to <8>, which satisfies 1.20 ≦ E2 / E1 ≦ 1.50.
<10> The toner for static charge image development according to any one of <1> to <9>, which satisfies 1.00 ≦ E3 / E2 ≦ 1.35.
<11> The toner for static charge image development according to <10>, which satisfies 1.00 ≦ E3 / E2 ≦ 1.20.
<12> A static charge image developer containing the toner for static charge image development according to any one of <1> to <11>.
<13> The electrostatic charge image developer according to <12>, which further contains a carrier.
<14> The carrier contains magnetic particles having an average surface unevenness interval Sm of 0.5 μm or more and 2.5 μm or less and an arithmetic surface roughness of the surface of 0.3 μm or more and 1.2 μm or less <13. > The electrostatic charge image developer.
<15> A toner cartridge that houses the toner for static charge image development according to any one of <1> to <11> and is attached to and detached from the image forming apparatus.
<16> The electrostatic charge image developer according to any one of <12> to <14> is contained, and the electrostatic charge image formed on the surface of the image holder by the electrostatic image developer is a toner image. A process cartridge that is attached to and detached from an image forming apparatus and has a developing means for developing as.
<17> An image holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming a static charge image on the surface of the charged image holder, and <12> to <14>. A developing means for accommodating the electrostatic charge image developer according to any one of the above and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer, and the image. An image forming apparatus including a transfer means for transferring a toner image formed on the surface of a holder to the surface of a recording medium, and a fixing means for fixing the toner image transferred on the surface of the recording medium.
<18> A charging step of charging the surface of the image holder, a static charge image forming step of forming a static charge image on the surface of the charged image holder, and any one of <12> to <14>. A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image with a charge image developer, and a transfer of transferring the toner image formed on the surface of the image holder to the surface of a recording medium. An image forming method comprising a step and a fixing step of fixing a toner image transferred to the surface of the recording medium.

According to the invention according to <1>, the ratio (E2 / E1) of the 100 Hz specific dielectric loss ratio E1 of the toner to the 1 kHz specific dielectric loss ratio E2 under the condition of 28 ° C. and 85% RH is less than 1.10. Or more than 1.80, or the ratio (E3 / E2) of the 1 kHz specific dielectric loss ratio E3 of the toner to E2 under the condition of 10 ° C. and 15% RH is more than 1.5. Provided is a toner for developing an electrostatic charge image, which is excellent in suppressing fog on the image to be obtained.
According to the invention according to <2>, the fog suppression property in the obtained image is more excellent than in the case where the coverage of the external additive is less than 40 area% or more than 70 area% on the surface of the toner particles. Toners for static charge image development are provided.
According to the invention according to <3>, there is provided a toner for static charge image development which is superior in fog suppression property in the obtained image as compared with the case where the external additive is contained in only one kind of particles.
According to the invention according to <4>, a toner for static charge image development, which is superior in fog suppression property in the obtained image, as compared with the case where the external additive contains only particles having a water content of more than 0.01% by mass. Provided.
According to the invention according to <5>, there is a toner for static charge image development that is superior in fog suppression property in the obtained image as compared with the case where the particles having a water content of 0.01% by mass or less are only titania particles. Provided.
According to the invention according to <6>, a toner for electrostatic charge image development which is superior in fog suppression property in the obtained image as compared with the case where the ^{external additive contains only particles having a volume resistance of less than 10 12 Ω · cm.} Is provided.
According to the invention according to <7>, for electrostatic charge image development, which is superior in fog suppression property in the obtained image, as compared with the case where the external additive contains only one kind of particles having a volume average particle diameter of 40 nm or more and 100 nm or less. Toner is provided.
According to the invention according to <8>, there is provided a toner for static charge image development which is superior in fog suppression property in the obtained image as compared with the case where E2 / E1 is less than 1.15 or more than 1.65. ..
According to the invention according to <9>, there is provided a toner for static charge image development which is superior in fog suppression property in the obtained image as compared with the case where E2 / E1 is less than 1.20 or more than 1.50. ..
According to the invention according to <10>, there is provided a toner for static charge image development which is superior in fog suppression property in the obtained image as compared with the case where E3 / E2 is more than 1.35.
According to the invention according to <11>, there is provided a toner for static charge image development which is superior in fog suppression property in the obtained image as compared with the case where E3 / E2 is more than 1.20.
According to the invention according to <12> or <13>, in the toner, the ratio of the specific dielectric loss ratio E1 of 100 Hz to the specific dielectric loss ratio E2 of 1 kHz (E2 / E1) under the condition of 28 ° C. and 85% RH. ) Is less than 1.10 or more than 1.80, or the ratio (E3 / E2) of the 1 kHz specific dielectric loss ratio E3 of the toner to E2 under the condition of 10 ° C. and 15% RH is 1.5. Provided is a static charge image developer having excellent fog suppression property in the obtained image as compared with the case where the above amount is exceeded.
According to the invention according to <14>, the carrier has an average surface roughness Sm of less than 0.5 μm or more than 2.5 μm, or an arithmetic surface roughness Ra of the surface of less than 0.3 μm or more than 1.2 μm. Provided is a static charge image developer having better fog suppression property in the obtained image as compared with the case where only the magnetic particles are contained.
According to the inventions <15> to <18>, in the toner, the ratio of the specific dielectric loss ratio E1 of 100 Hz to the specific dielectric loss ratio E2 of 1 kHz (E2 / E1) under the condition of 28 ° C. and 85% RH. ) Is less than 1.10 or more than 1.80, or the ratio (E3 / E2) of the 1 kHz specific dielectric loss ratio E3 of the toner to E2 under the condition of 10 ° C. and 15% RH is 1.5. Provided are a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method, which is superior in fog suppression property in the obtained image as compared with the case where the above amount is exceeded.

It is a schematic block diagram which shows the image forming apparatus which concerns on this embodiment. It is a schematic block diagram which shows the process cartridge which concerns on this embodiment.

When referring to the amount of each component in the composition in the present specification, if a plurality of substances corresponding to each component are present in the composition, the plurality of species present in the composition unless otherwise specified. Means the total amount of substances in.
In the present specification, the "toner for static charge image development" is also simply referred to as "toner", and the "static charge image developer" is also simply referred to as "developer".

Hereinafter, embodiments that are an example of the present invention will be described.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment contains toner particles and an external additive, and has a specific dielectric loss ratio E1 of 100 Hz and a specific dielectric loss ratio E2 of 1 kHz of the toner under the condition of 28 ° C. and 85% RH. The ratio of 1.10 ≦ E2 / E1 ≦ 1.80 is satisfied, and the ratio of the 1 kHz specific dielectric loss ratio E3 of the toner under the condition of 10 ° C. and 15% RH to the ratio of E2 is 1.0 ≦ E3 / E2. Satisfy ≤1.5.

In electrophotographic image formation, an image is formed by toner on a recording medium, and the image is fixed by fusion of toner by heat. In recent years, the size of the image forming apparatus has been reduced, the space around the fixing means has been reduced, and the developing means and the transferring means are also easily affected by the heat of the fixing means. When the temperature rises in the box, the humidity tends to drop over time in a high humidity environment. Therefore, continuous image formation may raise the temperature and lower the humidity. At this time, the developability of the toner changes due to the influence of temperature and humidity, and the concentration tends to change with time. Generally, the air flow in the image forming apparatus is adjusted by a fan or the like to prevent the temperature and humidity from changing, but the effect may not be sufficient depending on the installation location and usage. In this case, fog may occur in the image obtained over time.
The slope of the specific dielectric loss ratio correlates with the adsorbed water content of the particles used as the external additive, and it is estimated that the larger the value, the larger the water content. In addition, it is estimated that the amount of water that changes in the environment is very small, and the water that correlates with the slope of the relative dielectric loss rate is the adsorbed water that hardly moves in the environment.
When the specific dielectric loss ratios E1, E2, and E3 satisfy the above two equations, the amount of adsorbed water of the external additive is appropriate, so that an appropriate liquid cross-linking force works to suppress toner scattering, and in the obtained image. It is estimated that it has excellent fog suppression.

Further, when the specific dielectric loss ratios E1, E2 and E3 satisfy the above two equations, the amount of adsorbed water of the external additive is appropriate, so that an appropriate liquid cross-linking force acts and the temperature and humidity with respect to the developability of the toner It is estimated that the effect is suppressed and the image density maintenance is excellent.

Hereinafter, the toner for developing an electrostatic charge image according to the present embodiment will be described in detail.

The toner according to the present embodiment is composed of toner matrix particles (also referred to as “toner particles”) and, if necessary, an external additive.

(Dielectric loss ratios E1, E2 and E3)
In the static charge image developing toner according to the present embodiment, the ratio of the specific dielectric loss ratio E1 of 100 Hz to the specific dielectric loss ratio E2 of 1 kHz under the condition of 28 ° C. and 85% RH is 1.10 ≦ E2 / E1. The ratio of 1 kHz specific dielectric loss ratio E3 of the toner to E2 under the condition of 10 ° C. and 15% RH satisfies ≦ 1.80 and satisfies 1.0 ≦ E3 / E2 ≦ 1.5.
The dielectric property of toner, especially the relative dielectric loss rate, is an index showing the resistance of a dielectric placed under an AC electric field, and as described above, the slope of the specific dielectric loss rate is the gradient of the particles used as an external additive. It correlates with the adsorbed water content, and it is estimated that the larger the value, the larger the water content. In addition, it is estimated that the amount of water that changes in the environment is very small, and the water that correlates with the slope of the relative dielectric loss rate is the adsorbed water that hardly moves in the environment.
It is estimated that the value of E2 / E1 correlates with the adsorbed water content of the particles used as the external additive, and that the closer the value is to 1, the smaller the water content is, and the larger the value is, the larger the water content is.
In addition, the value of E3 / E2 correlates with the adsorbed moisture that has particles used as an external additive and that moves under 28 ° C. 85% RH conditions, 10 ° C. 15% RH conditions, and environmental changes in the environment. It is estimated that the closer the value is to 1, the more adsorbed water that hardly moves due to environmental changes, and the larger the value, the more water that moves due to environmental changes.

The toner for static charge image development according to the present embodiment preferably satisfies 1.10 ≦ E2 / E1 ≦ 1.65 from the viewpoint of fog suppression and image density maintenance, and 1.15 ≦ E2 /. It is more preferable to satisfy E1 ≦ 1.50, and it is particularly preferable to satisfy 1.20 ≦ E2 / E1 ≦ 1.50.
Further, the toner for static charge image development according to the present embodiment preferably satisfies 1.00 ≦ E3 / E2 ≦ 1.35 from the viewpoint of fog suppression and image density maintenance, and 1.00 ≦. It is more preferable to satisfy E3 / E2 ≦ 1.20, and it is particularly preferable to satisfy 1.00 ≦ E3 / E2 ≦ 1.10.

The 100 Hz specific dielectric loss ratio E1 of the toner for static charge image development according to the present embodiment under the condition of 28 ° C. and 85% RH is 0.011 or more and 0 from the viewpoint of fog suppression and image density maintenance. It is preferably .026 or less.
Further, the specific dielectric loss ratio E2 of the toner for static charge image development according to the present embodiment at 1 kHz under the condition of 28 ° C. and 85% RH is 0.012 from the viewpoint of fog suppression and image density maintenance. It is preferably 0.034 or less.
The 1 kHz specific dielectric loss ratio E3 of the toner for static charge image development according to the present embodiment under the condition of 10 ° C. and 15% RH is 0.012 or more and 0 from the viewpoint of fog suppression and image density maintenance. It is preferably .035 or less.

The specific dielectric loss ratio of the toner in this embodiment is measured as follows.
After leaving 5 g of the toner powder to be measured in an environment of 28 ° C. 85% RH or 10 ° C. 15% RH for 24 hours, it is placed in a mold having a diameter of 5 cm and a load of 10 ton is molded over 1 minute. This was left to stand again in an environment of 28 ° C. 85% RH or 10 ° C. 15% RH for 12 hours, and then installed on a dielectric measurement electrode of MULTI-FREQUENCY LCR METER (manufactured by Hulett Packard) to form JIS K6911 (JIS K6911). The measurement is carried out by the method described in 2006) under the conditions of a frequency of 100 Hz or 1 kHz and the temperature and humidity conditions.

(External agent)
The toner for static charge image development according to the present embodiment has an external additive on the surface of the toner particles.
The coverage of the external additive in the toner for static charge image development according to the present embodiment is not particularly limited, but is preferably 20 area% or more and 90 area% or less, preferably 30 area% or less, on the surface of the toner particles. It is preferably 80 area% or more, and particularly preferably 40 area% or more and 70 area% or less. Within the above range, the balance between the influence of the toner particles on the image formation and the influence of the change in the amount of water in the external additive is excellent, and the fog suppression property and the image density maintenance property are excellent.

Further, the external additive preferably contains particles having a water content of 0.01% by mass or less, and a water content of 0.0001% by mass or more and 0.01. It is more preferable to contain particles having a water content of 0.001% by mass or more and 0.01% by mass or less, particularly preferably to contain particles having a water content of 0.001% by mass or more.
Further, the particles having a water content of 0.01% by mass or less are preferably silica particles from the viewpoint of fog suppression and image density maintenance.

The method for measuring the amount of water in the external additive of the present embodiment is as follows.
Using a differential thermal scanning calorimetry DSC-60 manufactured by Shimadzu Corporation, the weight difference between 30 ° C. and 300 ° C. was measured under the condition of a heating rate of 10 ° C./min, and used as the water content.

The method for producing an external preparation having a low water content is not particularly limited, but for example, the external additive particles are treated at a high temperature (preferably 500 ° C. to 1,000 ° C.) and further in a low humidity environment (for example, 15%). A method of lowering the water content of the external additive particles and stabilizing the state by placing them in RH) can be mentioned.

Further, the external additive may contain particles having a water content of 0.01% by mass or less and particles having a water content of more than 0.01% by mass from the viewpoint of fog suppression and image density maintenance. It is preferable to include particles having a water content of 0.01% by mass or less and particles having a water content of more than 0.1% by mass. In the above aspect, it is easy to satisfy the range of E2 / E1 and the range of E3 / E2.
Further, the volume average particle diameter of the particles having a water content of 0.01% by mass or less is the volume average particle size of the particles having a water content of more than 0.01% by mass from the viewpoint of fog suppression and image density maintenance. It is preferably smaller than the diameter.
Furthermore, when the toner according to the present embodiment contains particles having a water content of 0.01% by mass or less and particles having a water content of more than 0.01% by mass as an external additive, it has a fog-suppressing property and a fog-suppressing property. From the viewpoint of image density maintenance, the area ratio of the particles having a water content of more than 0.01% by mass in direct contact with the surface of the toner particles is 0.01% by mass of the water content in direct contact with the surface of the toner particles. It is preferably more than the area ratio of the particles below.

The external additive preferably contains particles having a volume resistance of 10 ¹² Ω · cm or more, more preferably contains particles having a volume resistance of 10 ¹³ Ω · cm or more, and has a volume resistance of 10 ¹⁴ Ω · cm or more. It is particularly preferable to contain the particles of. In the above aspect, the resistance of the external additive is sufficient, the leakage of electric charge is suppressed, and the fog suppression property in the obtained image is more excellent when the environment changes.

The method for measuring the volume resistance of the external additive used in the present embodiment is as follows.
The particles (external additive) to be measured are placed flat on the surface of a circular jig on which a 20 cm ^{2 electrode plate is arranged. The same 20 cm 2} electrode plate as described above is placed on this, and the particle layer is sandwiched. In order to eliminate the voids between the particles, a load of 4 kg is applied on the electrode plate, and then the thickness (cm) of the particle layer is measured. Both electrodes above and below the carrier layer are connected to an electrometer and a high-voltage power generator. A high voltage is applied to both electrodes so that the electric field becomes a predetermined value, and the volume resistivity (Ω · cm) of the particles is calculated by reading the current value (A) flowing at this time. The formula for calculating the volume resistivity (Ω · cm) of particles is as shown in the following formula (3).
ρ = E × 20 / (I−I ₀ ) / L ・ ・ ・ Equation (3)
In the above formula, ρ is the volume resistivity (Ω · cm) of the fine particles, E is the applied voltage (V), I is the current value (A), I ₀ is the current value (A) at the applied voltage 0 V, and L is the carrier layer. Represents the thickness (cm) of each. The coefficient of 20 represents the area of the electrode plate (cm ² ).

From the viewpoint of fog suppression and image density maintenance, the external additive preferably contains particles having a volume average particle size of 40 nm or more and 100 nm or less, and contains only particles having a volume average particle size of 40 nm or more and 100 nm or less. Is more preferable.

The volume average particle size of the external additive in the present embodiment is determined by using a scanning electron microscope (SEM) (manufactured by Hitachi High-Technologies Co., Ltd., S-4700) with the toner externally added with the external additive. An image was taken at 40,000 times, observed with an acceleration voltage of 15 kV, an emission current of 20 μA, and a WD of 15 mm, and the specified external additive was analyzed with the image processing analysis software WinRof (manufactured by Mitani Shoji Co., Ltd.) to obtain the equivalent circle diameter. The particle size (equivalent to a circle) of at least 200 particles is measured, and the volume average particle size, which is the particle size cumulatively 50% from the small diameter side in the volume-based distribution of the particle size, is determined.

The volume average particle diameter of the particles used as an external additive other than those described above is preferably 10 nm or more and 400 nm or less, more preferably 20 nm or more and 200 nm or less, and 40 nm or more and 100 nm or less. Is particularly preferred.

The external additive is not particularly limited, and examples thereof include inorganic particles and organic particles.
Examples of the inorganic particles include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4, SrTiO 3 , and the like.
Examples of the organic particles include resin particles (resin particles such as silicone resin, polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, and fluorine-based highs. Particles of molecular weight) and the like.
Among them, the external additive is preferably silica particles or titania particles, and more preferably silica particles, from the viewpoint of fog suppression and image density maintenance.

The external additive preferably contains at least two types of particles, and more preferably contains at least two types of silica particles, from the viewpoint of fog suppression and image density maintenance.
Further, the external additive preferably contains sol-gel silica particles and fumed silica particles or silicone resin particles from the viewpoint of fog suppression and image density maintenance, and sol-gel silica particles and fumed silica. It is more preferable to include particles.
The ratio of the fumed silica particles to the sol-gel silica particles is preferably 1% by mass or more and 25% by mass or less with respect to the total mass of the sol-gel silica particles. The liquid cross-linking effect is largely due to the water content of the sol-gel silica particles, but the sol-gel silica particles alone change too much with respect to the environment. Within the above range, it is easy to suppress the change in water content of the sol-gel silica particles due to environmental changes, and it is more excellent in the fog suppression property and the image density maintenance property.

The surface of the external additive should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

The amount of the external additive added is preferably, for example, 0.01% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 6% by mass or less with respect to the toner particles.

(Toner particles)
The toner particles preferably contain, for example, a binder resin, a mold release agent, and, if necessary, a colorant and other additives.

-Bound resin-
Examples of the binder resin include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid). n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (eg, acrylonitrile, Methacrylic acid, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (eg, vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene, butadiene, etc.) Examples thereof include homopolymers of the above-mentioned monomers, and vinyl-based resins composed of copolymers in which two or more kinds of these monomers are combined.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence.
Among them, styrene acrylic resin or polyester resin is preferably used, and polyester resin is more preferably used.
These binder resins may be used alone or in combination of two or more.

Examples of the binder resin include an amorphous (also referred to as “non-crystalline”) resin and a crystalline resin.
From the viewpoint of the image strength of the fine line, the binding resin preferably contains a crystalline resin, and more preferably contains an amorphous resin and a crystalline resin.
The content of the crystalline resin is preferably 2% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less, based on the total mass of the binder resin.

The "crystallinity" of the resin means that the resin has a clear endothermic peak rather than a stepwise endothermic change in differential scanning calorimetry (DSC). Specifically, the temperature rise rate is 10 (° C.). / Min) indicates that the half-value width of the endothermic peak is within 15 ° C.
On the other hand, "amorphous" of the resin means that the half width exceeds 15 ° C., shows a stepwise endothermic amount change, or does not show a clear endothermic peak.

Examples of the polyester resin include known polyester resins.
As the polyester resin, a crystalline polyester resin may be used in combination with the amorphous polyester resin. The content of the crystalline polyester resin is preferably 2% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less, based on the total mass of the binder resin.

-Amorphous polyester resin Examples of the amorphous polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.). , Alicyclic dicarboxylic acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). 5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (eg, cyclohexanediol, cyclohexanedimethanol, etc.). Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out by using GPC / HLC-8120GPC manufactured by Tosoh Corporation as a measuring device and column / TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation in a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

Amorphous polyester resin is obtained by a well-known manufacturing method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the raw material. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. When a monomer having poor compatibility is present, it is advisable to condense the monomer having poor compatibility with the monomer and an acid or alcohol to be polycondensed in advance, and then polycondensate with the main component. ..

-Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecandicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc., aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.). Anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof can be mentioned.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol preferably has an aliphatic diol content of 80 mol% or more, preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperature of plastics".

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

The crystalline polyester resin can be obtained by a well-known manufacturing method, like, for example, an amorphous polyester.

The weight average molecular weight (Mw) of the binder resin is preferably 5,000 or more and 1,000,000 or less, more preferably 7,000 or more and 500,000 or less, and 25,000 or more and 60, from the viewpoint of image rubbing resistance. It is particularly preferable that it is 000 or less. The number average molecular weight (Mn) of the binder resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the binder resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight of the binder resin are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out by using GPC / HLC-8120GPC manufactured by Tosoh Corporation as a measuring device, using a column / TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation, and using a tetrahydrofuran (THF) solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The content of the binder resin is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and further preferably 60% by mass or more and 85% by mass or less with respect to the entire toner particles.

-Release agent-
Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montanic acid esters. ; And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperature of plastics".

The content of the release agent is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Colorant-
Examples of colorants include carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamin B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
The colorant may be used alone or in combination of two or more.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds of colorants may be used in combination.

The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Other additives-
Examples of other additives include known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or are toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering the core portion. You may. The toner particles having a core-shell structure are composed of, for example, a core portion containing a binder resin, a colorant and a mold release agent, if necessary, and a coating layer containing the binder resin.

The volume average particle size (D _50v ) of the toner is preferably 3.5 μm or more and less than 8.0 μm, more preferably 4.0 μm or more and 7.5 μm or less, and 4.5 μm from the viewpoint of outdoor visibility of the obtained image. More than 7.0 μm or less is particularly preferable.

The volume average particle size of the toner is measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution is measured using ISOTON-II (manufactured by Beckman Coulter).
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 mL of a 5 mass% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 mL or more and 150 mL or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and each particle has a particle size in the range of 2 μm or more and 60 μm or less using an aperture with an aperture diameter of 100 μm by Coulter Multisizer II. Measure the diameter. The number of particles to be sampled is 50,000.
For the measured particle size, a volume-based cumulative distribution is drawn from the small diameter side, and the particle size with a cumulative total of 50% is defined _{as the volume average particle size D 50v.}

In the present embodiment, the average circularity of the toner particles is not particularly limited, but from the viewpoint of improving the cleanability of the toner from the image holder, it is preferably 0.91 or more and 0.98 or less, and 0.94 or more. 0.98 or less is more preferable, and 0.95 or more and 0.97 or less is further preferable.

In the present embodiment, the circularity of the toner particles is (the peripheral length of a circle having the same area as the particle projection image) ÷ (the peripheral length of the particle projection image), and the average circularity of the toner particles is the circularity. It is a circularity with a cumulative total of 50% from the smallest side in the distribution. The average circularity of the toner particles is determined by analyzing at least 3,000 toner particles with a flow-type particle image analyzer.

The average circularity of the toner particles can be controlled, for example, by adjusting the stirring speed of the dispersion liquid, the temperature of the dispersion liquid, or the holding time in the fusion / coalescence step when the toner particles are produced by the aggregation / coalescence method. ..

[Toner manufacturing method]
Next, a method for producing toner according to this embodiment will be described.
The toner according to the present embodiment can be obtained by externally adding an external additive to the toner particles after producing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an agglomeration coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). These manufacturing methods are not particularly limited, and known manufacturing methods are adopted. Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particle dispersion liquid (after mixing other particle dispersion liquids as necessary). (In the dispersion), resin particles (other particles if necessary) are agglomerated to form agglomerated particles (aggregated particle forming step), and the agglomerated particle dispersion in which the agglomerated particles are dispersed is heated and agglomerated. Toner particles are manufactured through a step of fusing and coalescing the particles to form toner particles (fusing and coalescing step).

The details of each step will be described below.
In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and the release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
Along with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared.

The resin particle dispersion liquid is prepared, for example, by dispersing the resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles, the resin particles may be dispersed in a dispersion medium by a phase inversion emulsification method. In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to an organic continuous phase (O phase) to neutralize the resin, and then an aqueous medium (W phase) is used. ) Is added to perform phase inversion from W / O to O / W, and the resin is dispersed in an aqueous medium in the form of particles.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and further preferably 0.1 μm or more and 0.6 μm or less. preferable.
The volume average particle size of the resin particles is the volume with respect to the divided particle size range (channel) using the particle size distribution obtained by the measurement of a laser diffraction type particle size distribution measuring device (for example, manufactured by Horiba Seisakusho, LA-700). The cumulative distribution is subtracted from the small particle size side, and the particle size that is cumulatively 50% of all particles is measured as the volume average particle size D50v. The volume average particle size of the particles in the other dispersions is measured in the same manner.

The content of the resin particles contained in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

Similar to the resin particle dispersion, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. That is, regarding the volume average particle size, the dispersion medium, the dispersion method, and the content of the particles in the resin particle dispersion liquid, the colorant particles dispersed in the colorant particle dispersion liquid and the release agent particle dispersion liquid are used. The same applies to the disperse of the release agent particles.

-Agglomerated particle formation process-
Next, the resin particle dispersion liquid, the colorant particle dispersion liquid, and the release agent particle dispersion liquid are mixed. Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, pH 2 or more and 5 or less), a dispersion stabilizer is added as necessary, and then the resin particles. (Specifically, for example, the glass transition temperature of the resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower), and the particles dispersed in the mixed dispersion are aggregated. Form agglomerated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear type homogenizer, and an aggregating agent is added at room temperature (for example, 25 ° C.) to adjust the pH of the mixed dispersion to acidic (for example, pH 2 or more and 5 or less). Then, if necessary, heating may be performed after adding the dispersion stabilizer.

Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant contained in the mixed dispersion, an inorganic metal salt, and a divalent or higher valent metal complex. When a metal complex is used as the flocculant, the amount of the surfactant used is reduced and the charging characteristics are improved.
An additive that forms a complex or similar bond with the metal ion of the flocculant may be used together with the flocculant, if necessary. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate; and inorganic metal salts such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Polymers; and the like.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA); ..
The amount of the flocculant added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-Fusion / unification process-
Next, the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed is, for example, equal to or higher than the glass transition temperature of the resin particles (for example, 30 ° C. to 50 ° C. higher than the glass transition temperature of the resin particles) and the melting temperature of the release agent. By heating above, the agglomerated particles are fused and united to form toner particles.
In the fusion / union step, the resin and the release agent are in a fused state above the glass transition temperature of the resin particles and above the melting temperature of the release agent. After that, it is cooled to obtain toner.
As a method of adjusting the aspect ratio of the release agent in the toner, crystal growth is performed by holding the release agent at the temperature around the freezing point of the release agent for a certain period of time during cooling, or two or more types of release agents having different melting temperatures are used. This can promote crystal growth during cooling and can be adjusted.

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further adhered to the surface of the agglomerated particles. The step of forming the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated, and the second agglomerated particles are fused and united to form a core. -Toner particles may be produced through a step of forming toner particles having a shell structure.

After the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain a dried toner particle. In the cleaning step, from the viewpoint of chargeability, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water. In the solid-liquid separation step, suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. From the viewpoint of productivity, the drying step may be freeze-dried, air-flow-dried, fluid-dried, vibrating fluid-dried or the like.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like.

In the method for producing a toner according to the present embodiment, when particles having a water content of 0.01% by mass or less and particles having a water content of more than 0.01% by mass are used as at least an external additive, the fog inhibitory property and the fog-suppressing property and From the viewpoint of image density maintenance, particles having a water content of more than 0.01% by mass are first mixed with toner particles and externally attached, and then particles having a water content of more than 0.01% by mass are externally added. And particles having a water content of 0.01% by mass or less are preferably mixed and externally added.

<Static charge image developer>
The electrostatic charge image developer according to the present embodiment contains at least the toner according to the present embodiment. The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only the toner according to the present embodiment, or a two-component developer in which the toner and a carrier are mixed.
The electrostatic charge image developer according to the present embodiment is preferably a two-component developer mixed with the toner and the carrier according to the present embodiment.

The carrier is not particularly limited, and examples thereof include known carriers. As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder is impregnated with resin. Resin-impregnated carrier; etc.
The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel and cobalt, and magnetic oxides such as ferrite and magnetite. Of these, ferrite is preferable.

Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.
Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polypropylene, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent and the like can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and a solvent is removed.

From the viewpoint of fog suppression and image density maintenance, the carrier has a surface unevenness average interval Sm of 0.5 μm or more and 2.5 μm or less, and an arithmetic surface roughness of the surface of 0.3 μm or more 1 It is preferable to contain magnetic particles having a size of .2 μm or less.
The average unevenness spacing Sm on the surface of the magnetic particles is preferably 0.5 μm or more and 2.5 μm or less, and 0.8 μm or more and 1.5 μm or less, from the viewpoint of fog suppression and image density maintenance. Is more preferable, and 0.8 μm or more and 1.0 μm or less is particularly preferable.
Further, the arithmetic surface roughness Ra of the surface of the magnetic particles is preferably 0.3 μm or more and 1.2 μm or less, and 0.5 μm or more and 1.0 μm, from the viewpoint of fog suppression and image density maintenance. It is more preferably 0.5 μm or more, and particularly preferably 0.6 μm or less.

In the present embodiment, the surface roughness indexes Ra and Sm of the magnetic particles shall be measured by the following methods.

-Removal of coating resin-
20 g of the carrier is placed in 100 ml of toluene. Ultrasonic waves are applied for 30 seconds under the condition of 40 kHz. Separate the magnetic particles and the resin solution using filter paper that matches the particle size. Pour 20 mL of toluene over the magnetic particles remaining on the filter paper and wash. Next, the magnetic particles remaining on the filter paper are collected. Similarly, the recovered magnetic particles are placed in 100 ml of toluene and ultrasonic waves are applied for 30 seconds under the condition of 40 kHz. It is filtered in the same manner, washed with 20 ml of toluene, and then collected. This is done a total of 10 times. Finally, the recovered magnetic particles are dried.

-Measurement of surface unevenness average interval Sm and arithmetic mean roughness Ra-
The average distance between irregularities on the surface of the magnetic particles Sm and the arithmetic mean roughness Ra were measured for 50 magnetic particles using an ultra-depth color 3D shape measurement microscope (VK-9500, manufactured by Keyence Co., Ltd.) at a magnification of 3,000. The method of converting the surface by a factor is used.
For the unevenness average interval Sm, the roughness curve is obtained from the three-dimensional shape of the observed magnetic particle surface, and the average value of the intervals of one mountain valley cycle obtained from the intersection where the roughness curve intersects the average line is obtained. The reference length for obtaining the Sm value is 10 μm, and the cutoff value is 0.08 mm.
For the arithmetic mean roughness Ra, a roughness curve is obtained, and the Ra value is obtained by summing and averaging the measured value of the roughness curve and the absolute value of the deviation to the average value. The reference length for obtaining the Ra value is 10 μm, and the cutoff value is 0.08 mm.
The Sm value and Ra value are measured according to JIS B0601 (1994 version).

The method for producing the magnetic particles satisfying Ra and Sm is not particularly limited, but the magnetic particles can be produced, for example, as follows.

The surface roughness of the magnetic particles (average surface roughness interval Sm and surface arithmetic surface roughness Ra) is adjusted to some extent by the temperature and oxygen concentration at the time of firing during the production of ferrite particles, but the main purpose of firing is the magnetic particles. It is to change to a structure with magnetization.

Therefore, the magnetic particles constituting the carrier used in the present embodiment can be suitably produced by the combination of the following (A) to (E).
(A) Temporary firing is performed before firing.
(B) Further pulverization is performed, and granulation is performed from a slurry having a pulverized particle size adjusted.
(C) SiO ₂ , SrCO _3, etc. are used as the surface conditioner.
(D) Adjusting the temperature and oxygen concentration at the time of firing (E) The temperature is given while flowing the magnetic particles obtained by firing.

After performing temporary firing before firing, it is crushed to control the particle size. Granulate into a pulverized product having the desired particle size and determine the volume average particle size. The size of the grain boundaries, which are the basis of magnetic particles, is controlled by the crushed particle size after calcination. Further, the surface irregularities may be finely adjusted by using _{SiO 2} , SrCO _3, or the like as an additive. When SiO ₂ is added, the area of grain boundaries becomes wider and Sm can be adjusted to be larger. SrCO ₃ has the effect of increasing Ra.

Next, firing is performed, the temperature and oxygen concentration are adjusted, and the magnetization is matched to obtain ferrite. When the firing temperature is high, Sm tends to be large, and when the oxygen concentration is high, Ra tends to be large. In addition, the firing temperature and oxygen concentration strongly affect the resistance and magnetization. The higher the temperature and the lower the oxygen concentration, the higher the magnetization and the lower the resistance.

After calcination is completed and ferriticization is performed, the internal voids are reduced at a temperature at which the ferriticization reaction does not occur. As a result, the desired magnetic particles can be obtained.

From the viewpoint of image density uniformity, the average particle size of the number of carriers in the present embodiment is preferably 15 μm or more and 70 μm or less, more preferably 20 μm or more and 60 μm or less, further preferably 22 μm or more and 50 μm or less, and particularly preferably 24 μm or more and 40 μm or less. ..

The method for measuring the number average particle diameter of carriers in this embodiment is shown below.
A Coulter Multisizer II (manufactured by Beckman Coulter) is used as a measuring device, and ISOTON-II (manufactured by Beckman Coulter) is used as an electrolytic solution. First, a surfactant, preferably an alkylbenzene sulfone, is used as a dispersant. 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 mL of a 5 mass% aqueous solution of sodium acid, and this is added to 100 mL or more and 150 mL or less of the electrolytic solution. The electrolytic solution in which this measurement sample is suspended is dispersed for about 1 minute with an ultrasonic disperser, and the particle size is 2.0 μm or more and 60 μm or less using the aperture with an aperture diameter of 100 μm by the Coulter Multisizer II. Measure the particle size distribution of the particles in the range of. The number of particles to be measured is 50,000.
For the measured particle size distribution, a cumulative distribution is drawn from the small particle size side for the number of divided particle size ranges (channels), and the particle size with a cumulative total of 50% is defined as the number average particle size (D50v).

The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

<Image forming device, image forming method>
The image forming apparatus / image forming method according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes an image holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge. A developing means that accommodates an image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the static charge image developer, and a recording medium that records the toner image formed on the surface of the image holder. It is provided with a transfer means for transferring to the surface of the recording medium and a fixing means for fixing the toner image transferred to the surface of the recording medium. Then, as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

In the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holder, a static charge image forming step of forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge according to the present embodiment. A development step of developing an electrostatic charge image formed on the surface of an image holder as a toner image with an image developer, and a transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium. An image forming method (image forming method according to the present embodiment) having a fixing step of fixing a toner image transferred to the surface of a recording medium is carried out.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers the toner image to the surface and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after transferring the toner image, cleans the surface of the image holder before charging. A known image forming apparatus such as a device provided with cleaning means; a device provided with static elimination means for irradiating the surface of the image holder with static elimination light after transfer of the toner image and before charging; is applied.
When the image forming apparatus according to the present embodiment is an intermediate transfer type apparatus, the transfer means transfers, for example, an intermediate transfer body in which a toner image is transferred to the surface and a toner image formed on the surface of the image holder. A configuration having a primary transfer means for primary transfer to the surface of the body and a secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing means containing the electrostatic charge image developer according to the present embodiment is preferably used.

Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. In the following description, the main parts shown in the figure will be described, and the description thereof will be omitted for the others.

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a first electrophotographic system that outputs images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, also simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

Above each unit 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 extends through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20, and travels in a direction from the first unit 10Y to the fourth unit 10K. There is. A force is applied to the support roll 24 in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. An intermediate transfer belt cleaning device 30 is provided on the image holding surface side of the intermediate transfer belt 20 so as to face the drive roll 22.

Developing equipment for each unit 10Y, 10M, 10C, 10K (example of developing means) Yellow, magenta, cyan, and black contained in toner cartridges 8Y, 8M, 8C, and 8K for each of 4Y, 4M, 4C, and 4K. Each toner is supplied.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration and operation, here, the first to fourth units 10Y, 10M, 10C, and 10K form a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt. The unit 10Y of No. 1 will be described as a representative.

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying a charged toner to the static charge image. A primary transfer roll (an example of primary transfer means) 5Y that transfers a toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (image holder cleaning means) that removes the toner remaining on the surface of the photoconductor 1Y after the primary transfer. Example) 6Ys are arranged in order.

The primary transfer roll 5Y is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. A bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

Hereinafter, the operation of forming a yellow image in the first unit 10Y will be described.
First, prior to the operation, the surface of the photoconductor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoconductor 1Y is formed by laminating a photosensitive layer on a conductive substrate (for example, a volume resistivity of 1 × 10 ^{-6 Ωcm or less at 20 ° C.).} This photosensitive layer usually has a high resistivity (resistance of a general resin), but has a property that when a laser beam is irradiated, the specific resistance of the portion irradiated with the laser beam changes. Therefore, the surface of the charged photoconductor 1Y is irradiated with the laser beam 3Y from the exposure apparatus 3 according to the image data for yellow sent from the control unit (not shown). As a result, an electrostatic charge image of the yellow image pattern is formed on the surface of the photoconductor 1Y.

The static charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitizer layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y rotates to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is developed and visualized as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, and has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. Toner. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roll 5Y acts on the toner image. The toner image on the photoconductor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity (+) opposite to the polarity (−) of the toner, and is controlled to, for example, + 10 μA by a control unit (not shown) in the first unit 10Y. The toner remaining on the photoconductor 1Y is removed by the photoconductor cleaning device 6Y and recovered.

The primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 on which the yellow toner image is transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiple-transferred. Will be done.

The intermediate transfer belt 20 in which the toner images of four colors are multiplex-transferred through the first to fourth units includes the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the image holding surface of the intermediate transfer belt 20. It leads to a secondary transfer unit composed of a secondary transfer roll (an example of the secondary transfer means) 26 arranged on the side. On the other hand, the recording paper (an example of the recording medium) P is fed through the supply mechanism into the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other at a predetermined timing, and the secondary transfer bias is supported by the support roll. It is applied to 24. The transfer bias applied at this time is (-) polarity, which is the same polarity as the toner polarity (-), and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

The recording paper P on which the toner image is transferred is sent to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, the toner image is fixed on the recording paper P, and the fixed image is formed. It is formed. The recording paper P for which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

Examples of the recording paper P for transferring the toner image include plain paper used in electrophotographic copiers, printers, and the like. Examples of the recording medium include an OHP sheet and the like in addition to the recording paper P. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper in which the surface of plain paper is coated with resin or the like, art paper for printing, or the like is used. Suitable for use.

<Process cartridge, toner cartridge>
The process cartridge according to the present embodiment contains the electrostatic charge image developer according to the present embodiment, and is a developing means for developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer. It is a process cartridge that is attached to and detached from the image forming apparatus.

The process cartridge according to the present embodiment includes a developing means and, if necessary, at least one selected from other means such as an image holder, a charging means, an electrostatic charge image forming means, and a transfer means. It may be a configuration.

Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited thereto. In the following description, the main parts shown in the figure will be described, and the description thereof will be omitted for the others.

FIG. 2 is a schematic configuration diagram showing an example of a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 2 is provided around the photoconductor 107 (an example of an image holder) and the photoconductor 107 by, for example, a housing 117 provided with a mounting rail 116 and an opening 118 for exposure. The charged roll 108 (an example of the charging means), the developing device 111 (an example of the developing means), and the photoconductor cleaning device 113 (an example of the cleaning means) are integrally combined and held and configured to form a cartridge. There is.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming means), 112 is a transfer device (an example of a transfer means), 115 is a fixing device (an example of a fixing means), and 300 is a recording paper (an example of a recording medium). Is shown.

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that houses the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge accommodates a replenishing toner for supplying to the developing means provided in the image forming apparatus.

The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing apparatus 4Y, 4M, 4C, and 4K are toner cartridges corresponding to the respective colors. Is connected by a toner supply pipe (not shown). When the amount of toner contained in the toner cartridge is low, this toner cartridge is replaced.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples. In the following description, unless otherwise specified, "parts" and "%" are all based on mass.
Further, E1, E2 and E3 in the toner were measured by the above-mentioned method.

<Preparation of resin particle dispersion 1>
-Ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.): 37 parts by mass-Neopentyl glycol (manufactured by Wako Pure Chemical Industries, Ltd.): 65 parts by mass-1,9-nonanediol (Wako Pure Chemical Industries, Ltd.) (Manufactured by): 32 parts by mass, terephthalic acid (manufactured by Wako Pure Chemical Industries, Ltd.): 96 parts by mass The above components are placed in a flask, the temperature is raised to 200 ° C. over 1 hour, and the inside of the reaction system is uniformly stirred. After confirming that, 1.2 parts by mass of dibutyltin oxide was added. Further, the temperature was raised from the same temperature to 240 ° C. over 6 hours while distilling off the generated water, and the dehydration condensation reaction was continued at 240 ° C. for another 4 hours, the acid value was 9.4 mgKOH / g, and the weight average molecular weight was increased. A polyester resin having a glass transition point of 13,000 and a glass transition point of 62 ° C. was obtained.
Then, this was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) in a molten state at a rate of 100 g / min. In a separately prepared aqueous medium tank, add 0.37% by mass dilute ammonia water obtained by diluting the reagent ammonia water with ion-exchanged water, and heat it to 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. It was transferred to the above-mentioned Cavitron at the same time as the polyester resin melt. The Cavitron was operated under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² , and of resin particles having an average particle size of 160 nm, a solid content of 30%, a glass transition point of 62 ° C., and a weight average molecular weight of Mw of 13,000. A dispersion liquid (resin particle dispersion liquid 1) was obtained.

<Preparation of colorant particle dispersion 1>
-Cyan pigment (CI Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.): 10 parts by mass-Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts by mass -Ion-exchanged water: 80 parts by mass The above components are mixed and dispersed for 1 hour with a high-pressure impact disperser Ultimateizer (HJP30006, manufactured by Sugino Machine Co., Ltd.), and colored with a volume average particle size of 180 nm and a solid content of 20%. An agent particle dispersion was obtained.

<Preparation of colorant particle dispersion 2>
-Carbon black: 10 parts by mass-Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts by mass-Ion-exchanged water: 80 parts by mass A high-pressure impact disperser that mixes the above components. The mixture was dispersed for 1 hour with an ultimateizer (HJP30006, manufactured by Sugino Machine Co., Ltd.) to obtain a colorant particle dispersion liquid 2 having a volume average particle size of 180 nm and a solid content of 20%.

<Synthesis of binder resin 1>
-Decandioic acid (manufactured by Tokyo Chemical Industry Co., Ltd.): 81 parts by mass-Hexanediol (manufactured by Wako Pure Chemical Industries, Ltd.): 47 parts by mass The above components are placed in a flask and the temperature is 160 ° C. over 1 hour. After confirming that the inside of the reaction system was uniformly stirred, 0.03 parts by mass of dibutyltin oxide was added. Further, the temperature was raised from the same temperature to 200 ° C. over 6 hours while distilling off the generated water, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to terminate the reaction. After cooling the reaction solution, the solid substance obtained by solid-liquid separation was dried under a vacuum at 40 ° C. to obtain a binder resin 1.
The melting point of the obtained binder resin 1 was 64 ° C. as a result of measurement using a differential thermal scanning calorimeter DSC-7 manufactured by Perkinelmer. The weight average molecular weight was 15,000 when measured using a molecular weight measuring instrument HLC-8020 manufactured by Tosoh Corporation using tetrahydroxyfuran (THF) as a solvent.

<Preparation of resin particle dispersion 2>
-Bound resin 1:50 parts by mass-Anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 1.5 parts by mass-Nonionic surfactant (Emargen 147, manufactured by Kao Corporation) ): 0.5 parts by mass, ion-exchanged water: 200 parts by mass The above components are heated to 120 ° C., sufficiently dispersed with Ultratarax T50 manufactured by IKE, and then dispersed with a pressure discharge homogenizer. It was recovered when the volume average particle size reached 180 nm. In this way, a resin particle dispersion liquid 2 having a solid content of 20% was obtained.

<Preparation of mold release agent particle dispersion>
-Paraffin wax (HNP-9, manufactured by Nippon Seikan Co., Ltd.): 50 parts by mass-Anionic surfactant (Neogen SC, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 1.5 parts by mass-Nonionic surfactant Activator (Emargen 147, manufactured by Kao Co., Ltd.): 0.5 parts by mass, ion-exchanged water: 200 parts by mass After heating the above components to 120 ° C. and sufficiently dispersing them with Ultratarax T50 manufactured by IKE. , Dispersion treatment was carried out with a pressure discharge type homogenizer to obtain a release agent particle dispersion having a volume average particle size of 200 nm and a solid content of 20%.

<Manufacturing of toner 1>
-Resin particle dispersion: 1: 150 parts by mass-Colorant particle dispersion: 25 parts by mass-Release agent particle dispersion: 35 parts by mass-Resin particle dispersion 2: 50 parts by mass-Polyaluminum chloride: 0.4% by mass Part ・ Ion exchanged water: 100 parts by mass After sufficiently mixing and dispersing the above components in a round stainless steel flask using Ultratarax T50 manufactured by IKE, while stirring the inside of the flask with a heating oil bath 48 After heating to ° C. and holding for 60 minutes, 70 parts by mass of the same resin particle dispersion 1 as described above was slowly added thereto. Then, after adjusting the pH in the system to 8.0 using an aqueous sodium hydroxide solution having a concentration of 0.5 mol / L, the stainless flask was sealed, the stirring shaft was magnetically sealed, and stirring was continued. It was heated to 90 ° C. and held for 30 minutes. After completion of the reaction, the temperature was lowered at 5 ° C./min, and the mixture was filtered and sufficiently washed with ion-exchanged water, and then solid-liquid separation was performed by Nucci-type suction filtration. This was further redispersed using 3,000 parts by mass of ion-exchanged water at 30 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 6 more times, and when the pH of the filtrate became 7.54 and the electrical conductivity was 6.5 μS / cm, the No. 1 was obtained by suction filtration using the Nutche type. Solid-liquid separation was performed using 5A filter paper. Then, vacuum drying was continued for 24 hours to obtain toner 1 (Cyan1).

<Preparation of toner 2>
Toner 2 (Cyan2) was produced in the same manner as in the production of toner 1, except that the following components were used as the components to be mixed and dispersed first.
-Resin particle dispersion: 1: 150 parts by mass-Colorant particle dispersion: 1:25 parts-Release agent particle dispersion: 45 parts by mass-Resin particle dispersion 2: 50 parts by mass-Polyaluminum chloride: 0.4 Parts by mass / ion-exchanged water: 100 parts by mass

<Preparation of toner 3>
Toner 3 (Kuro1) was produced in the same manner as in the production of toner 1, except that the following components were used as the components to be mixed and dispersed first.
-Resin particle dispersion 1: 180 parts by mass-Colorant particle dispersion 2: 25 parts-Removing agent particle dispersion: 35 parts by mass-Resin particle dispersion 2: 50 parts by mass-Polyaluminum chloride: 0.4 Parts by mass / ion-exchanged water: 100 parts by mass

<Preparation of toner 4>
Toner 4 (Kuro2) was produced in the same manner as in the production of toner 1, except that the following components were used as the components to be mixed and dispersed first.
-Resin particle dispersion 1: 180 parts by mass-Colorant particle dispersion 2: 25 parts-Release agent particle dispersion: 45 parts by mass-Resin particle dispersion 2: 50 parts by mass-Polyaluminum chloride: 0.4 Parts by mass / ion-exchanged water: 100 parts by mass

<Silica pretreatment>
-Preparation of silica 1-
Silica particles (OX50, manufactured by Nippon Aerosil Co., Ltd.) are treated at 800 ° C to 1,000 ° C, left in a 15% RH environment at 23 ° C for 1 week, and then treated with hexamethyldisilazane (HMDS) to obtain silica. I got 1. The volume average particle diameter of the obtained silica 1 was 40 nm, the water content was 0.01% by mass, and the volume resistance was 10 ¹⁴ Ω · cm.

-Preparation of silica 2-
To a glass reaction vessel equipped with a stirrer, a dropping nozzle and a thermometer, 300 parts of methanol and 70 parts of 10% aqueous ammonia were added and mixed to obtain an alkaline catalyst solution.
After adjusting this alkaline catalyst solution to 30 ° C., 120 parts of tetramethoxysilane (TMS) and 33 parts of 8.0% aqueous ammonia were added dropwise at the same time with stirring to make a hydrophilic silica particle dispersion (solid content). Concentration 12.0%) was obtained. Here, the dropping time was set to 22 minutes.
Then, the obtained silica particle dispersion was concentrated to a solid content concentration of 40% with a rotary filter R-fine (manufactured by Kotobuki Kogyo Co., Ltd.). This concentrated product was used as a silica particle dispersion.
250 parts of the silica particle dispersion liquid was dried by spray drying (spray drying) to obtain silica particles. Further, the silica particles are heat-treated (500 ° C. to 800 ° C.) and then left in an environment of 40 ° C. and 95% RH for one week, and then hexamethyldisilazane (HMDS) 60 is applied to 100 parts of the silica particles. Surface treatment was performed using the parts to obtain silica 2. The average particle size of the obtained silica 2 volumes was less than 90 nm.
The water content of silica 2 was 0.6% by mass, and the volume resistance was 10 ¹¹ Ω · cm.

(Examples 1 to 8 and Comparative Examples 1 to 3)
<Making external toner>
60 parts of the toner mother particles shown in Table 1 and silica 1 are weighed as shown in Table 1, and after stirring at 10,000 rpm (revolutions per minute) for 30 seconds using a sample mill, silica 2 Was added in the amounts shown in Table 1 and further stirred at 13,000 rpm for 30 seconds to obtain toner (external toner).
Table 1 shows the values of E1, E2, E3, E2 / E1 and E3 / E2 in the obtained external toner.

<Making carrier a>
-Preparation of coating liquid-
Cyclohexyl acrylate resin (weight average molecular weight 50,000): 36 parts by mass Carbon black VXC72 (manufactured by Cabot): 4 parts by mass Toluene: 250 parts by mass Isopropyl alcohol: 50 parts by mass Glass beads (grains) in the same amount as the above components and toluene (Diameter: 1 mm) was put into a sand mill manufactured by Kansai Paint Co., Ltd. and stirred at a rotation speed of 1,200 rpm for 30 minutes to prepare a coating liquid having a solid content of 11% by mass.

-Preparation of magnetic particles a-
Fe ₂ O ₃ is mixed by 1,318 parts by mass, Mn (OH) ₂ by 586 parts by mass, Mg (OH) ₂ by 96 parts by mass, and SrCO ₃ by 1 part by mass. And zirconia beads having a media diameter of 1 mm were added, and the mixture was crushed and mixed with a sand mill.

<< Temporary firing >>
Then, the zirconia beads were removed by filtration, dried, and further prepared as a mixed oxide in a rotary kiln under the conditions of 20 rpm, 900 ° C., and 60 minutes.

<< Slurry crushing >>
Next, polyvinyl alcohol and water were added as dispersants, 6.6 parts by mass of polyvinyl alcohol was further added, and pulverization was performed with a wet ball mill until the volume average particle size became 2.0 μm.

<< Granulation >>
Next, the particles were granulated with a spray dryer so that the dry particle size was 38 μm, and dried.

<< Main firing >>
Further, firing was carried out in an electric furnace for 5 hours in an oxygen-nitrogen mixed atmosphere having a temperature of 1,240 ° C. and an oxygen concentration of 1.0%.

<< Additional process >>
After undergoing a crushing step and a classification step of the obtained particles, the particles were heated in a rotary kiln at 15 rpm and 900 ° C. for 2 hours, and further subjected to a classification step to obtain magnetic particles a.
The surface unevenness average spacing Sm of the magnetic particles a was 1.0 μm, the surface arithmetic surface roughness Ra was 0.9 μm, and the volume average particle size was 35 μm.

-Formation of resin coating layer-
Put 2,000 parts by mass of magnetic particles 1 in a vacuum degassing type kneader, further put 560 parts by mass of coating liquid 1, and while stirring, reduce the pressure to 1 atm-200 mmHg at 60 ° C., mix for 15 minutes, and then ascend. The mixture was heated / depressurized and stirred and dried at 94 ° C./1 atm-720 mmHg for 30 minutes to obtain resin-coated particles. Next, sieving was performed with a sieving network of a 75 μm mesh to obtain a carrier a.
The coating amount of the coating resin layer of the carrier a with respect to the magnetic particles was 3.5% by mass.

<Preparation of carrier b>
Slurry pulverization was carried out until the volume average particle size became 1.6 μm, and the magnetic particles b and carriers were obtained in the same manner as in the preparation of carrier a, except that the temperature was 1,200 ° C. and the oxygen concentration was 1.1% at the time of main firing. b was prepared.
The surface unevenness average spacing Sm of the magnetic particles b was 2.8 μm, the surface arithmetic surface roughness Ra was 1.5 μm, and the volume average particle size was 36 μm.

<Preparation of developer>
7 parts of the obtained external toner was mixed with 100 parts of the carrier shown in Table 1, stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a mesh size of 250 μm. The developing agents of Examples 1 to 9 or Comparative Examples 1 to 3 were obtained, respectively.

<Evaluation>
The obtained electrostatic charge image developer and built-in fan were installed near the fuser to create an air flow between the fuser and the developer to suppress heat transfer to the developer. Using a DocuCenter400 remodeling machine modified so that it could be turned on and off, one 10 cm square solid print was performed in an environment of 28 ° C. and 85%. At this time, the built-in fan continued to operate.
After that, the built-in fan was stopped. A4 full-scale printing of 10,000 sheets of halftone 20% was continuously performed. Further, one solid print of 10 cm square was carried out. The image density and fog of the first and 10,000th images were confirmed.

-Evaluation of image density maintenance-
The image density maintainability was evaluated based on the following criteria based on the image density difference (ΔE) between the first image and the 10,000th image.
A: 0 or more and 0.5 or less B: 0.5 or more and 1.5 or less C: 1.5 or more and 2.0 or less D: 2.0 or more

-Evaluation of fog suppression-
As for the fog suppression property, visually observing the 10,000th printed matter, D is the one where the color can be confirmed on the blank paper around the image, C is the one where the color can be slightly confirmed, B is the one where the color can hardly be confirmed, and B cannot be confirmed at all. The thing was evaluated as A.

From the results shown in Table 1, it can be seen that the static charge image developing toner of this example is superior to the electrostatic charge image developing toner of the comparative example in the fog suppression property in the obtained image.
Further, from the results shown in Table 1 above, it can be seen that the toner for static charge image development of this example is also excellent in image density maintenance.

1Y, 1M, 1C, 1K photoconductor (example of image holder)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3 Exposure device (an example of static charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor cleaning device (an example of image holder cleaning means)
8Y, 8M, 8C, 8K Toner Cartridge 10Y, 10M, 10C, 10K Image Forming Unit 20 Intermediate Transfer Belt (Example of Intermediate Transfer)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
28 Fixing device (an example of fixing means)
30 Intermediate transfer belt cleaning device (an example of intermediate transfer body cleaning means)
P Recording paper (an example of recording medium)

107 Photoreceptor (an example of image holder)
108 Charging roll (an example of charging means)
109 Exposure device (an example of static charge image forming means)
111 Developing equipment (an example of developing means)
112 Transfer device (an example of transfer means)
113 Photoreceptor cleaning device (an example of image holder cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening for exposure 200 Process cartridge 300 Recording paper (an example of recording medium)

Claims (18)

Contains toner particles and an additive
The ratio of the 100 Hz specific dielectric loss ratio E1 to the 1 kHz specific dielectric loss ratio E2 of the toner under the condition of 28 ° C. and 85% RH satisfies 1.10 ≦ E2 / E1 ≦ 1.80.
A toner for static charge image development in which the ratio of the 1 kHz specific dielectric loss ratio E3 of the toner to the E2 under the condition of 10 ° C. and 15% RH satisfies 1.0 ≦ E3 / E2 ≦ 1.5. The toner for static charge image development according to claim 1, wherein the coverage of the external additive is 40 area% or more and 70 area% or less on the surface of the toner particles. The toner for developing an electrostatic charge image according to claim 1 or 2, wherein the external additive contains at least two kinds of particles. The toner for developing an electrostatic charge image according to any one of claims 1 to 3, wherein the external additive contains particles having a water content of 0.01% by mass or less. The toner for static charge image development according to claim 4, wherein the particles having a water content of 0.01% by mass or less are silica particles. The toner for static charge image development according to any one of claims 1 to 5, wherein the external additive contains particles having a volume resistance of 10 ^{12 Ω · cm or more.} The toner for static charge image development according to any one of claims 1 to 6, wherein the external additive contains two types of particles having a volume average particle diameter of 40 nm or more and 100 nm or less. The toner for developing an electrostatic charge image according to any one of claims 1 to 7, which satisfies 1.15 ≦ E2 / E1 ≦ 1.65. The toner for developing an electrostatic charge image according to claim 8, which satisfies 1.20 ≦ E2 / E1 ≦ 1.50. The toner for developing an electrostatic charge image according to any one of claims 1 to 9, which satisfies 1.00 ≦ E3 / E2 ≦ 1.35. The toner for developing an electrostatic charge image according to claim 10, which satisfies 1.00 ≦ E3 / E2 ≦ 1.20. A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 11. The electrostatic charge image developer according to claim 12, further comprising a carrier. The thirteenth aspect of claim 13, wherein the carrier includes magnetic particles having an average surface unevenness interval Sm of 0.5 μm or more and 2.5 μm or less and an arithmetic surface roughness of the surface of 0.3 μm or more and 1.2 μm or less. Static charge image developer. A toner cartridge that houses the toner for static charge image development according to any one of claims 1 to 11 and is attached to and detached from an image forming apparatus. The electrostatic charge image developer according to any one of claims 12 to 14 is contained, and the electrostatic charge image developer formed on the surface of the image holder is developed as a toner image. A process cartridge that has a developing means and is attached to and detached from an image forming apparatus. Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
The electrostatic charge image developer according to any one of claims 12 to 14 is contained, and the electrostatic charge image developer formed on the surface of the image holder is developed as a toner image. Development means and
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising. The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to any one of claims 12 to 14.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

Images