JP2020204686A - Toner for electrostatic charge image development - Google Patents

Abstract

To provide a toner for electrostatic charge image development that is excellent in low-temperature fixability, heat-resistant storage property, and sticking resistance.SOLUTION: A toner for electrostatic charge image development of the present invention includes a toner base particle that contains at least a mold release agent and a binder resin, and the binder resin contains at least a crystalline polyester resin. In viscoelasticity measurement with temperature modulation of the toner for electrostatic charge image development, when the tangent loss (tanδ) of dynamic viscoelasticity is taken at each of temperatures of 45°C, 50°C, 55°C, and 60°C, the following formulas (1) to (3) are satisfied, and a curve of tanδ with respect to temperature has one maximum value within a temperature range of 60 to 70°C. Formula (1) [tanδ(60°C)/tanδ(55°C)]<[tanδ(55°C)/tanδ(45°C)]; formula (2) 1.0≤[tanδ(55°C)/tanδ(45°C)]≤5.0; formula (3) [(tanδ(60°C)/tanδ(50°C)]≤2.5.SELECTED DRAWING: Figure 1

Description

The present invention relates to a toner for developing an electrostatic charge image, and more particularly to a toner for developing an electrostatic charge image having excellent low-temperature fixability, heat-resistant storage property, and sticking resistance.

In the print-on-demand (POD) market, where low-volume, high-mix products are advancing, and in the office copier market, where energy saving is required, high-speed printing speed and high-speed printing speed are available as toner for static charge image development that supports high-speed printing and energy saving. , Low temperature fixability of toner that can be fixed instantly even with low power is required. When the toner resin is melted at a low temperature in order to improve the low temperature fixability of the toner, the toner resin and the mold release agent melt when the toner or the two-component developer is stored in a high temperature and high humidity environment, and the toner aggregates. May occur and the heat-resistant storage property may deteriorate.

In Patent Document 1, in a toner for static charge image development having a core layer containing a first binder resin and a shell layer covering the core layer and containing a second binder resin, the positive contact loss of dynamic viscoelasticity. There are two temperatures of the maximum value of (tan δ) in the range of 90 ° C. or less, one maximum value is in the range of less than 60 ° C., and the other maximum value is in the range of 60 to 90 ° C. Attempts have been made to improve low-temperature fixability and heat-resistant storage by using toner.

Further, in Patent Document 2, various types are used by controlling the dynamic viscoelasticity of the toner for static charge image development in a wide range of temperature ranges by using a binder resin obtained by reacting two kinds of specific resins. Disclosed is a toner for static charge image development that can suppress the occurrence of sleeve fusion and high temperature offset even when an image forming apparatus and a transfer material are used.

On the other hand, when the output image is left in a high temperature and high humidity environment, the toner resin for static charge image development on the surface of the image melts and sticks to other paper or plastic objects in contact with the image. Is a problem. In particular, sticking to plastic objects, whose use has been increasing in recent years, is often a problem.

Although Patent Documents 1 and 2 mention low-temperature fixability, heat-resistant storage property, and high-temperature offset property, they do not mention sticking property, and low-temperature fixability, heat-resistant storage property, and sticking resistance. The development of an excellent static charge image developing toner is awaited.

Japanese Unexamined Patent Publication No. 2006-293285 Japanese Unexamined Patent Publication No. 2012-150466

The present invention has been made in view of the above problems and situations, and a problem to be solved thereof is to provide a toner for static charge image development excellent in low temperature fixability, heat storage resistance, and sticking resistance.

In order to solve the above problems, the present inventor controls the tangential loss (tan δ) of the dynamic viscoelasticity in a specific temperature region of the static charge image developing toner in the process of examining the cause of the above problems. It has been found that a toner for static charge image development having excellent low-temperature fixability, heat-resistant storage property, and sticking resistance can be obtained.

That is, the above problem according to the present invention is solved by the following means.

1. 1. At least, it is a toner for developing an electrostatic charge image containing toner matrix particles containing a release agent and a binder resin.
The binding resin contains at least a crystalline polyester resin and
In the viscoelasticity measurement by temperature modulation of the electrostatic charge image developing toner, the tangent loss (tanδ) of the dynamic viscoelasticity at temperatures of 45 ° C., 50 ° C., 55 ° C., and 60 ° C. was tanδ (45 ° C.), respectively. , Tanδ (50 ° C.), tanδ (55 ° C.), and tanδ (60 ° C.).
The value of the ratio of tan δ (55 ° C) to tan δ (45 ° C) is [tan δ (55 ° C) / tan δ (45 ° C)], and the value of the ratio of tan δ (60 ° C) to tan δ (50 ° C) is [tan δ (60 ° C)]. ° C.) / Tanδ (50 ° C.)] and the ratio of tanδ (60 ° C.) to tanδ (55 ° C.) is defined as [tanδ (60 ° C.) / tanδ (55 ° C.)], and the following equations (1) to Satisfy (3) and
A toner for static charge image development, characterized in that the curve of tan δ with respect to temperature has one maximum value in the temperature range of 60 to 70 ° C.
Equation (1) [tan δ (60 ° C.) / tan δ (55 ° C.)] <[tan δ (55 ° C.) / tan δ (45 ° C.)],
Equation (2) 1.0 ≤ [tan δ (55 ° C) / tan δ (45 ° C)] ≤ 5.0,
Equation (3) [(tan δ (60 ° C) / tan δ (50 ° C)] ≤ 2.5

2. 2. The toner for developing an electrostatic charge image according to the first item, wherein the [tan δ (60 ° C.) / tan δ (55 ° C.)] is in the range of 1.0 to 3.0.

3. 3. The value (A / B) of the mass ratio of the content (B) of the release agent to the content (A) of the crystalline polyester is in the range of 40/60 to 60/40. The toner for developing an electrostatic charge image according to the first or second item.

By the above means of the present invention, it is possible to provide a toner for static charge image development which is excellent in low temperature fixability, heat storage property, and sticking resistance.

Although the mechanism of expression or mechanism of action of the effect of the present invention has not been clarified, it is inferred as follows.

<Low temperature fixability>
The toner for static charge image development is the above formula (1) [tan δ (60 ° C.) / tan δ (55 ° C.)] <[tan δ (55 ° C.) / tan δ (45 ° C.)], and the formula (2) 1.0 ≦ [ By satisfying tan δ (55 ° C.) / tan δ (45 ° C.)] ≤ 5.0 and equation (3) [(tan δ (60 ° C.) / tan δ (50 ° C.)] ≤ 2.5, under high temperature environment storage The viscoelasticity of the toner is gradually changed, and the viscoelasticity of the toner having both low temperature fixability and heat-resistant storage property can be obtained. Further, at a temperature in the range of 60 to 70 ° C., the curve of tan δ with respect to the temperature is By having one maximum value, the crystalline resin easily promotes the melting of the toner, and the low temperature fixability is further improved.

<Heat-resistant storage>
Similarly, by satisfying the above formulas (1) to (3), toner viscoelasticity having both low-temperature fixability and heat-resistant storage property can be obtained, and further, at a temperature in the range of 60 to 70 ° C. Since the curve of tan δ with respect to temperature has one maximum value, the crystalline resin and the mold release agent bleed out to the toner surface before the toner is fixed on the recording medium, and the toners agglomerate with each other to reduce heat resistance. It is possible to prevent this from happening.

<Adhesion resistance>
Similarly, by satisfying the above formulas (1) to (3), it is possible to obtain a toner viscoelasticity having both low temperature fixability and sticking resistance, and further, at a temperature in the range of 60 to 70 ° C. Since the curve of tan δ with respect to temperature has one maximum value, the crystalline resin and mold release agent on the image surface bleed out to the image surface after fixing, and the surface of other images or plastic objects in contact with the image. It is possible to prevent sticking to.

Although the mechanism of action for these behaviors is not clear, the mass ratio value (A / B) of the content of the crystalline polyester (A) and the content of the release agent (B) is correlated. When the value of the mass ratio (mass (A) of crystalline polyester / mass (B) of mold release agent) is 40/60 or more, the low-melting crystalline polyester improves low-temperature fixability. Further, when the mass ratio value is 60/40 or less, the proportion of the low-melt crystalline polyester exposed on the toner surface layer is reduced and the heat-resistant storage property is improved, and the mass ratio value is 60 /. When the ratio is 40 or less, the ratio of the mold release agent exposed on the image surface is maintained, so that the sticking resistance is improved. Therefore, the ratio of the content of the crystalline polyester to the content of the mold release agent However, it is presumed that the viscoelasticity of the toner image is controlled and the above effect is exhibited.

A graph plotting the tangent loss (tan δ) of dynamic viscoelasticity with respect to temperature modulation of the electrostatic charge image developing toner in Examples and Comparative Examples. Schematic diagram showing an example of the overall configuration of the electrophotographic image forming apparatus

The toner for static charge image development of the present invention is a toner for static charge image development containing at least toner matrix particles containing a mold release agent and a binder resin, and the binder resin is at least a crystalline polyester. In the viscoelasticity measurement by temperature modulation of the toner for static charge image development containing a resin, the tangential loss (tan δ) of the dynamic viscoelasticity at temperatures of 45 ° C., 50 ° C., 55 ° C., and 60 ° C. was obtained, respectively. Let tan δ (45 ° C.), tan δ (50 ° C.), tan δ (55 ° C.), and tan δ (60 ° C.), and set the ratio of tan δ (55 ° C.) to tan δ (45 ° C.) as [tan δ (55 ° C.) / tan δ. (45 ° C.)], the value of the ratio of tan δ (60 ° C.) to tan δ (50 ° C.) is the value of the ratio of tan δ (60 ° C.) to [tan δ (60 ° C.) / tan δ (50 ° C.)] and tan δ (55 ° C.). When the value is [tan δ (60 ° C.) / tan δ (55 ° C.)], the above equations (1) to (3) are satisfied, and the curve of tan δ with respect to temperature is maximized in the temperature range of 60 to 70 ° C. It is characterized by having one value. This feature is a technical feature common to or corresponding to the following embodiments.

The [tan δ (60 ° C.) / tan δ (55 ° C.)] is preferably adjusted to the range of 1.0 to 3.0, because the viscoelasticity changes more slowly under high temperature, and thus heat resistance. It is preferable because it is a toner having excellent storability and sticking resistance. Further, when the range is set to 1.0 to 2.0, the viscoelasticity changes more slowly under high temperature, so that the toner has more excellent heat storage resistance and sticking resistance.

Further, the value (A / B) of the mass ratio of the content (B) of the release agent to the content (A) of the crystalline polyester is in the range of 40/60 to 60/40. The content ratio is preferable from the viewpoint of good low-temperature fixability, heat-resistant storage property, and sticking resistance.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described in detail. In the present application, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value.

<< Outline of Toner for Electrostatic Image Development of the Present Invention >>
The toner for static charge image development of the present invention is a toner for static charge image development containing at least toner matrix particles containing a mold release agent and a binder resin, and the binder resin is at least a crystalline polyester. In the viscoelasticity measurement by temperature modulation of the toner for static charge image development containing a resin, the tangential loss (tan δ) of the dynamic viscoelasticity at temperatures of 45 ° C., 50 ° C., 55 ° C., and 60 ° C. was obtained, respectively. Let tan δ (45 ° C.), tan δ (50 ° C.), tan δ (55 ° C.), and tan δ (60 ° C.), and set the ratio of tan δ (55 ° C.) to tan δ (45 ° C.) as [tan δ (55 ° C.) / tan δ. (45 ° C.)], the value of the ratio of tan δ (60 ° C.) to tan δ (50 ° C.) is the value of the ratio of tan δ (60 ° C.) to [tan δ (60 ° C.) / tan δ (50 ° C.)] and tan δ (55 ° C.). When the value is [tan δ (60 ° C.) / tan δ (55 ° C.)], the following equations (1) to (3) are satisfied, and the curve of tan δ with respect to temperature is maximized in the temperature range of 60 to 70 ° C. It is characterized by having one value.

Equation (1) [tan δ (60 ° C.) / tan δ (55 ° C.)] <[tan δ (55 ° C.) / tan δ (45 ° C.)],
Equation (2) 1.0 ≤ [tan δ (55 ° C) / tan δ (45 ° C)] ≤ 5.0,
Equation (3) [(tan δ (60 ° C) / tan δ (50 ° C)] ≤ 2.5

Satisfying the above formulas (1) to (3) is a gradual change in the viscoelasticity of the toner under high temperature environment storage, so that the toner has both low temperature fixability, heat resistance storage property and sticking resistance. It obtains viscoelasticity.

Further, at a temperature in the range of 60 to 70 ° C., since the curve of tan δ with respect to the temperature has one maximum value, the crystalline resin facilitates the melting of the toner resin at the time of fixing the toner image, and the low temperature fixability. To improve.

Further, it is possible to prevent the crystalline resin and the mold release agent from bleeding out to the surface of the toner before the toner is fixed on the recording medium, and the toners agglomerate with each other to reduce the heat-resistant storage property.

Further, it is possible to prevent the crystalline resin and the mold release agent on the image surface from bleeding out to the image surface after fixing and sticking to the surface of another image or plastic object in contact with the image.

FIG. 1 is a graph plotting the tangent loss (tan δ) of dynamic viscoelasticity with respect to temperature modulation of the electrostatic charge image developing toner in Examples and Comparative Examples.

FIG. 1A is a graph of viscoelasticity measurement by temperature modulation according to the embodiment of the present invention.

FIG. 1B is an enlarged graph of the viscoelasticity measurement at 60 to 70 ° C. of the embodiment according to the present invention.

FIG. 1C is a graph of viscoelasticity measurement by temperature modulation of a comparative example.

In the graphs of Examples and Comparative Examples, whether or not equations (1) to (3) are satisfied, and whether or not the curve of tan δ with respect to temperature has one maximum value in the temperature range of 60 to 70 ° C. The relationship between this and the low temperature fixability, heat storage property, and sticking resistance will be described in detail in the section of Examples, but here, the "maximum value" according to the present invention will be described.

In the viscoelasticity measurement by temperature modulation of the static charge image developing toner, "having a maximum value" in the change of the tangent loss (tan δ) of the dynamic viscoelasticity with respect to the temperature means the temperature on the horizontal axis and the tangent on the vertical axis. In the loss curve, there is a point where the tangent loss value changes from increase to decrease when the temperature value is changed from low temperature to high temperature, and it is called the maximum value (peak top or peak) of that value. ) Is called the "maximum value".

In order to obtain the effect of the present invention, the toner for developing an electrostatic charge image of the present invention needs to have one peak of the tangent loss in the temperature range of 60 to 70 ° C. It is considered that this is because the presence of one peak in the range of 60 to 70 ° C. causes the binding resin and the crystalline polyester resin to be compatible with each other. Therefore, the toner of the present invention may have one peak in the range of 60 to 70 ° C., and may have a peak in the range of less than 60 ° C. or the temperature range of more than 70 ° C. ..

Further, the maximum value of the tan δ curve with respect to temperature is preferably a peak in which the temperature width at the intersection of the tangent line at the first minimum value on the high temperature side of the maximum value and the tan δ curve with respect to temperature is 20 ° C. or less. Here, the "minimum value" means that the value of the tangent loss changes from a decrease to an increase when the temperature value is changed from a low temperature to a high temperature.

For example, when two peaks are present in the range of 70 ° C. or lower, it is estimated that the two types of binder resins are independently present in the toner in an incompatible state, and are within the range of 70 ° C. or lower. If there is only one peak in, it is presumed that the binder resin and the crystalline polyester resin are compatible with each other.

From FIGS. 1 (a) and 1 (b), for the toner of the example, in the temperature range of 60 to 70 ° C., Example 1 (65.2 ° C.), Example 2 (65.5 ° C.), Examples 3 (64.9 ° C.), Example 4 (68.4 ° C.), Example 5 (62.3 ° C.), and Example 6 (65.8 ° C.) have maximum values.

On the other hand, from FIG. 1 (c), Comparative Example 1 (59.5 ° C.), Comparative Example 4 (54.8 ° C.), and Comparative Example 5 (80.4 ° C.) each have a peak top, and the temperature is 60. Within the range of ~ 70 ° C., there is no peak of tangent loss.

The viscoelasticity measurement by temperature modulation (tangent loss (tanδ) measurement of dynamic viscoelasticity) is as follows.

(Preparation of sample for measuring tangent loss (tan δ) of dynamic viscoelasticity)
Using a pressure molding machine (NT-100H, manufactured by NPA System Co., Ltd.), the toner is pressurized to 3000 kgf (1 kgf ≈ 9.8 N) at room temperature for 30 seconds to form a columnar column with a diameter of about 8 mm and a height of about 2 mm. Mold into a sample.

(Measurement procedure of tangent loss (tan δ) of dynamic viscoelasticity)
Using a viscoelasticity measuring device (ARES-G2 rheometer manufactured by TA Instruments), the columnar sample prepared above is placed on a parallel plate heated to a temperature equal to or higher than the softening point of the toner, and heated and melted. After that, a load is applied in the vertical direction so that the axial force does not exceed 10 (g weight), and the sample is fixed to the parallel plate. In this state, the temperature of the parallel plate and the columnar sample is lowered to the measurement start temperature of 30 ° C., and the viscoelasticity data is measured. The measured data is transferred to a computer equipped with Microsoft Windows 7 (“Windows” is a registered trademark of the company), and the data is transferred through the control, data collection and analysis software (TRIOS) operating on the computer, and 45 Read the value of tan δ at ° C., 55 ° C., and 60 ° C., and read the temperature indicating the maximum value of tan δ.

(Measurement conditions for tangent loss (tan δ) of dynamic viscoelasticity)
Parallel plate: Aluminum plate with a diameter of 8 mm Measurement frequency: 6.28 radians / second Measurement strain setting: Set the initial value to 0.1% and perform measurement in the automatic measurement mode.
Sample elongation correction: Adjust in automatic measurement mode.
Measurement temperature: Heat from 30 ° C to 200 ° C at 3.0 ° C per minute.
Measurement interval: Viscoelastic data is measured every 1 ° C.

Hereinafter, the components of the present invention will be described in detail.

[1] Toner for developing an electrostatic charge image The toner for developing an electrostatic charge image of the present invention (hereinafter, also simply referred to as “toner”) is a toner composed of at least a toner base particle containing a mold release agent and a binder resin. Contains particles.

In addition to the binder resin, the toner matrix particles according to the present invention may contain various internal additives such as a colorant, a charge control agent, and a surfactant, if necessary.

In the present invention, the "toner" refers to an aggregate of "toner particles", and the toner particles refer to the above-mentioned toner matrix particles to which an external additive is added. Further, in the following description, when it is not necessary to particularly distinguish between the toner base particles and the toner particles, it is also simply referred to as “toner particles”.

[1.1] Bending Resin The binding resin according to the present invention contains at least a crystalline polyester resin. It is preferable that the binder resin contained in the toner matrix particles contains at least one resin selected from the crystalline polyester resin in a proportion of less than 50% by mass.

Further, the binder resin contains a vinyl resin in addition to the crystalline polyester resin, and further contains an amorphous polyester resin or a modified polyester resin (hybrid amorphous polyester resin) in which a part thereof is modified. However, it is preferable. Further, the vinyl resin may be an amorphous resin or a crystalline resin, or both may be used in combination.

[Crystalline polyester resin]
The crystalline polyester resin is a known polyester resin obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid component) or a hydroxycarboxylic acid and a divalent or higher alcohol (polyhydric alcohol component). , A resin having a clear melting peak rather than a stepwise change in heat absorption in differential scanning calorimetry (DSC). Specifically, the clear melting peak means that the half width of the melting peak in the second heating process is within 15 ° C. in the DSC curve obtained by the differential scanning calorimetry shown below for the crystalline polyester resin alone. It means a certain peak.

The melting point of the crystalline polyester resin is preferably in the range of 55 to 90 ° C., more preferably 55 to 75 ° C., and particularly preferably 60 to 70 ° C. When the melting point of the crystalline polyester resin is in the above range, sufficient low-temperature fixability and excellent image storage stability can be obtained. The melting point of the crystalline polyester resin can be controlled by the resin composition. Here, the melting point of the crystalline polyester resin is the peak top temperature of the melting peak in the second temperature raising process in the DSC curve obtained by the differential scanning calorimetry of the crystalline polyester resin alone, which will be described later. When a plurality of melting peaks are present in the DSC curve, the peak top temperature of the melting peak having the largest heat absorption is set as the melting point.

The valences of the polyvalent carboxylic acid and the polyhydric alcohol constituting the crystalline polyester resin are preferably 2 to 3 respectively, and particularly preferably 2 each. Therefore, in the following, the case where the valence is 2 each (that is, the dicarboxylic acid component and the diol component) will be described in detail.

(Dicarboxylic acid component)
As the dicarboxylic acid component, it is preferable to use an aliphatic dicarboxylic acid, and if necessary, an aromatic dicarboxylic acid may be used in combination. As the aliphatic dicarboxylic acid, it is preferable to use a linear type. There is an advantage that the crystallinity is improved by using the linear type. The dicarboxylic acid component may be used alone or in combination of two or more.

Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelliic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acid (dodecanedioic acid), 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid (tetradecanedioic acid), 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecan Examples thereof include dicarboxylic acid and 1,18-octadecanedicarboxylic acid. Among them, an aliphatic dicarboxylic acid having 6 to 14 carbon atoms excluding carboxycarbon is preferable, an aliphatic dicarboxylic acid having 8 to 12 carbon atoms is more preferable, and an aliphatic dicarboxylic acid having 8 to 10 carbon atoms is even more preferable.

Examples of the aromatic dicarboxylic acid that can be used together with the aliphatic dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-biphenyl. Examples thereof include dicarboxylic acids. Among these, terephthalic acid, isophthalic acid, and t-butylisophthalic acid are preferably used from the viewpoint of availability and emulsification.

In addition to the above dicarboxylic acids, trivalents or more such as trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid and the like. Dicarboxylic acid having a double bond such as polyvalent carboxylic acid, maleic acid, fumaric acid, 3-hexendioic acid, 3-octendioic acid, and anhydride of the above carboxylic acid compound, or 1 to 1 carbon atoms. The alkyl ester of 3 or the like may be used.

As the dicarboxylic acid component for forming the crystalline polyester resin, the content of the aliphatic dicarboxylic acid is preferably 50 constituent mol% or more, more preferably 70 constituent mol% or more, and further preferably 80. Constituent mol% or more, particularly preferably 100 constituent mol%. When the content of the aliphatic dicarboxylic acid in the dicarboxylic acid component is 50 constituent mol% or more, the crystallinity of the crystalline polyester resin can be sufficiently ensured.

(Diol component)
As the diol component, it is preferable to use an aliphatic diol, and if necessary, a diol other than the aliphatic diol may be used in combination. As the aliphatic diol, it is preferable to use a linear type diol. There is an advantage that the crystallinity is improved by using the linear type. The diol component may be used alone or in combination of two or more.

Examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-. Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14- Examples thereof include tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, neopentyl glycol and the like. Among them, an aliphatic diol having 2 to 12 carbon atoms is preferable, an aliphatic diol having 5 to 10 carbon atoms is more preferable, and an aliphatic diol having 7 to 9 carbon atoms is even more preferable.

Examples of the diol that can be used together with the aliphatic diol include a diol having a double bond, a diol having a sulfonic acid group, and the like. Specifically, the diol having a double bond includes, for example, 1,4-. Examples thereof include butenediol, 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol and the like. Further, a trihydric or higher polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane or sorbitol may be used.

As the diol component for forming the crystalline polyester resin, the content of the aliphatic diol is preferably 50 constituent mol% or more, more preferably 70 constituent mol% or more, and further preferably 80 constituent mol% or more. % Or more, particularly preferably 100 constituent mol%. When the content of the aliphatic diol in the diol component is 50 constituent mol% or more, the crystallinity of the crystalline polyester resin can be ensured, and a toner having excellent low-temperature fixability can be obtained.

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 3000 to 100,000, preferably 4000 to 50000, from the viewpoint of surely achieving both sufficient low-temperature fixability and excellent long-term heat-resistant storage stability. More preferably, and particularly preferably 5000 to 20000. In the present specification, the value obtained by the method described later is adopted for the measurement of the weight average molecular weight (Mw).

The ratio of the diol component and the dicarboxylic acid component used is such that the molar ratio of the hydroxy group of the diol component to the carboxy group of the dicarboxylic acid component ([OH] / [COOH]) is 2.5 / 1 to 0.5. It is preferably 1/1, more preferably 2/1 to 1/1.

As catalysts that can be used in the production of crystalline polyester resins, alkali metal compounds such as sodium and lithium; compounds containing Group 2 elements such as magnesium and calcium; aluminum, zinc, manganese, antimony, titanium, tin, Examples thereof include metal compounds such as zirconium and germanium; phosphite compounds; phosphoric acid compounds; and amine compounds. Specifically, examples of the tin compound include dibutyltin oxide, tin octylate, tin dioctylate, and salts thereof. Examples of the titanium compound include titanium alkoxides such as tetranormal butyl titanate, tetraisopropyl titanate, tetramethyl titanate and tetrastearyl titanate; titanium acylates such as polyhydroxytitanium stearate; titanium tetraacetylacetonate, titanium lactate and titanium triethanolami. Titanium chelate such as nate can be mentioned. Examples of the germanium compound include germanium dioxide and the like. Further, examples of the aluminum compound include oxides such as polyaluminum hydroxide and aluminum alkoxides such as tributylaluminate. These may be used individually by 1 type or in combination of 2 or more type.

The polymerization temperature of the crystalline polyester resin is not particularly limited, but is preferably 150 to 250 ° C. The polymerization time of the crystalline polyester resin is not particularly limited, but is preferably 0.5 to 15 hours. During the polymerization, the pressure inside the reaction system may be reduced, if necessary.

The melting point of the crystalline polyester is preferably 55 ° C. or higher and 75 ° C. or lower, and more preferably 60 ° C. or higher and 70 ° C. or lower.

The melting point of crystalline polyester can be measured using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60A) in accordance with ASTM D3418. The temperature correction of the detection unit of this device (DSC-60A) uses the melting point of indium and the melting point of zinc, and the heat of fusion of indium is used to correct the amount of heat. For the sample, use an aluminum pan, set an empty pan for control, raise the temperature at a heating rate of 10 ° C./min, hold at 200 ° C. for 5 minutes, and use liquid nitrogen from 200 ° C. to 0 ° C.- The temperature is lowered at 10 ° C./min, held at 0 ° C. for 5 minutes, the temperature is raised again from 0 ° C. to 200 ° C. at 10 ° C./min, and analysis is performed from the heat absorption curve at the time of the second temperature rise. Is the melting point of the crystalline polyester.

From the viewpoint of obtaining the effects of the present invention, the content of the crystalline polyester resin is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, in the toner base particles.

(Styrene / acrylic modified crystalline polyester resin)
As the crystalline polyester resin, a styrene / acrylic modified crystalline polyester resin in which a styrene / acrylic polymerized segment and a crystalline polyester polymerized segment are bonded may be used.

Here, the "styrene / acrylic modified crystalline polyester resin" means that a styrene / acrylic copolymer molecular chain (styrene / acrylic polymerized segment) is chemically bonded to a crystalline polyester molecular chain (crystalline polyester polymerized segment). It is also a resin composed of polyester molecules having a block copolymer structure.

The method for forming the crystalline polyester polymerized segment is not particularly limited. The specific types of the polyvalent carboxylic acid and the polyhydric alcohol used for forming the polymerization segment and the polycondensation conditions of these monomers are the same as described above, and thus the description thereof will be omitted here.

On the other hand, the styrene / acrylic polymerization segment constituting the styrene / acrylic modified crystalline polyester resin is formed by addition polymerization of at least a styrene monomer and a (meth) acrylic acid ester monomer. The styrene monomer and the (meth) acrylic acid ester monomer used are not particularly limited, but those used in the amorphous vinyl resin described later are exemplified, and one kind or two or more kinds can be used. ..

The content ratio of the crystalline polyester polymerized segment in the styrene / acrylic modified crystalline polyester resin is not particularly limited, but is preferably in the range of 60 to 99% by mass with respect to 100% by mass of the styrene / acrylic modified polyester resin. ..

The content ratio of the styrene / acrylic polymerized segment in the styrene / acrylic modified crystalline polyester resin (hereinafter, also referred to as “styrene / acrylic modified amount”) is not particularly limited, but is 100% by mass of the styrene / acrylic modified crystalline polyester resin. On the other hand, it is preferably in the range of 1 to 40% by mass.

Specifically, the amount of styrene / acrylic modification is the total mass of the resin material used for synthesizing the styrene / acrylic modified crystalline polyester resin, that is, the unmodified crystalline polyester resin to be the crystalline polyester polymerization segment. With respect to the total mass of the monomer for synthesis, the styrene monomer and the (meth) acrylic acid ester monomer to be the styrene / acrylic polymerization segment, and the bireactive monomer for binding them. , The ratio of the total mass of the styrene monomer and the (meth) acrylic acid ester monomer.

Here, the "bireactive monomer" is a monomer that bonds a styrene / acrylic polymerization segment and a crystalline polyester polymerization segment, and is a hydroxy group, a carboxy group, or an epoxy group that forms a crystalline polyester polymerization segment. , A monomer having both a group selected from a primary amino group and a secondary amino group and an ethylenically unsaturated group forming a styrene-acrylic polymerization segment in the molecule.

The amount of both reactive monomers used is preferably in the range of 1 to 20% by mass, with the total amount of the monomers constituting the styrene / acrylic polymerization segment being 100% by mass, from the viewpoint of improving the low temperature fixability.

[Vinyl resin]
The binder resin according to the present invention preferably contains 50% by mass or more of a vinyl resin.

If the vinyl resin is a noncrystalline resin, the endothermic curve obtained by the differential scanning calorimetry (DSC), it has a glass transition temperature T _g, it is not clear endothermic peak at a melting point i.e. heating amorphous A resin that exhibits properties. Further, the vinyl resin may contain a urethane resin or a urea resin.

The polymerizable monomer constituting the vinyl resin preferably contains the following vinyl monomers (1) to (9) from the viewpoint of polymerizable properties (formability of resin particles). These vinyl monomers may be used alone or in combination of two or more.

(1) Styrene or styrene derivative Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pt- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene and the like.

(2) Methacrylic acid ester or methacrylic acid ester derivative Methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, methacrylic 2-Ethylhexyl acid acid, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, methacrylic 2-Hydroxybutyl acid, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, polyethylene glycol monomethacrylate, etc.

(3) Acrylic acid ester or acrylic acid ester derivative Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate , Stearyl acrylate, lauryl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, acrylate 4-Hydroxybutyl, polyethylene glycol monoacrylate, etc.

(4) Olefins Ethylene, propylene, isobutylene, etc.

(5) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc.

(6) Vinyl ethers Vinyl methyl ether, vinyl ethyl ether, etc.

(7) Vinyl Ketones Examples thereof include vinyl methyl ketone, vinyl ethyl ketone, and vinyl hexyl ketone.

(8) N-Vinyl Compounds Examples thereof include N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone.

(9) Monomer having a carboxy group Acrylic acid, methacrylic acid, maleic acid, itaconic acid, silicic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester and the like.

(10) Others Vinyl compounds such as vinylnaphthalene and vinylpyridine; acrylic acid or methacrylic acid derivatives such as acrylonitrile and methacrylic acid; reactive surfactants having a vinyl bond such as sodium salt of ethylene methacrylate adduct sulfate ester. etc.

Among the above vinyl monomers, (1) styrene or styrene derivative, (2) methacrylic acid ester or methacrylic acid ester derivative, (3) acrylic acid ester or acrylic acid ester derivative, (9) from the viewpoint of stabilizing the polymerization reaction. ) A monomer having a carboxy group and a reactive surfactant having a vinyl bond are preferable. More preferably, styrene, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-methacrylate. It is a sodium salt of butyl, t-butyl methacrylate, isobutyl methacrylate, acrylic acid, methacrylic acid, and an adduct sulfate ester of ethylene methacrylate.

The weight average molecular weight (Mw) of the vinyl resin is preferably 1000 to 500000, more preferably 20000 to 20000.

In the present specification, the weight average molecular weight (Mw) of the resin is measured by using GPC (gel permeation chromatography) under the following conditions. That is, the measurement sample is dissolved in tetrahydrofuran so as to have a concentration of 1 mg / mL. As the dissolution conditions, it is carried out at room temperature for 5 minutes using an ultrasonic disperser. Then, after treating with a membrane filter having a pore size of 0.2 μm, a 10 μL sample solution is injected into the GPC. In the molecular weight measurement of a sample, the molecular weight distribution of the sample is calculated using a calibration curve measured using monodisperse polystyrene standard particles. Ten points are used as polystyrene for calibration curve measurement.

The glass transition temperature (Tg) of the vinyl resin is preferably 0 ° C. or higher and 100 ° C., and more preferably 10 ° C. or higher and 80 ° C. or lower. Further, it is preferably 40 ° C. or higher and 70 ° C. or lower, and more preferably 45 ° C. or higher and 65 ° C. or lower.

In the present specification, the glass transition temperature of the vinyl resin can be measured by using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60A) in accordance with ASTM D3418. The temperature correction of the detection unit of this device (DSC-60A) uses the melting point of indium and the melting point of zinc, and the heat of fusion of indium is used to correct the amount of heat. For the sample, use an aluminum pan, set an empty pan for control, raise the temperature at a heating rate of 10 ° C./min, hold at 200 ° C. for 5 minutes, and use liquid nitrogen from 200 ° C. to 0 ° C.- Lower the temperature at 10 ° C / min, hold at 0 ° C for 5 minutes, raise the temperature again from 0 ° C to 200 ° C at 10 ° C / min, analyze from the heat absorption curve at the second temperature rise, and perform onset temperature. Let Tg.

The content of the vinyl resin is preferably 60 to 90% by mass, particularly preferably 70 to 85% by mass, based on the total mass of the toner matrix particles.

The method for producing the vinyl resin is not particularly limited, and a massive polymerization method can be used by using an arbitrary polymerization initiator such as a peroxide, a persulfate, a persulfide, or an azo compound usually used for the polymerization of the above-mentioned monomers. Examples thereof include a method of polymerizing by a known polymerization method such as a solution polymerization method, an emulsion polymerization method, a miniemulsion method, and a dispersion polymerization method. In addition, a commonly used chain transfer agent can be used for the purpose of adjusting the molecular weight. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans and mercapto fatty acid esters.

[Amorphous polyester resin]
The amorphous polyester resin exhibits amorphousness among polyester resins obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). It is a polyester resin. When forming a toner having a core-shell structure, an amorphous polyester resin can also be used as the material of the shell.

As the polyvalent carboxylic acid and the polyhydric alcohol, the same materials as those of the above-mentioned crystalline polyester resin can be used, and for example, bisphenols such as bisphenol A and bisphenol F, their ethylene oxide adducts, and propylene. Bisphenol alkylene oxide adducts such as oxide adducts can also be used. Among these, it is preferable to use an ethylene oxide adduct and a propylene oxide adduct of bisphenol A as the polyhydric alcohol component, particularly from the viewpoint of improving the charge uniformity of the toner. These polyhydric alcohol components may be used alone or in combination of two or more.

Regarding the ratio of polyvalent carboxylic acid to polyhydric alcohol, the equivalent ratio [OH] / [COOH] of the hydroxy group of the polyhydric alcohol to the carboxy group of the polyvalent carboxylic acid is 1 / 1.5 to 1.5 / 1. It is preferably in the range of 1 / 1.2 to 1.2 / 1.

The number average molecular weight of the amorphous polyester resin is preferably in the range of 2000 to 10000. The number average molecular weight can be measured in the same manner as in the case of the above-mentioned amorphous vinyl resin.

The glass transition point of the amorphous polyester resin is preferably in the range of 20 to 70 ° C. The glass transition point can be measured in the same manner as in the case of the above-mentioned amorphous vinyl resin.

The amorphous polyester resin can be a hybrid amorphous polyester resin modified with a styrene / acrylic resin (hereinafter, also simply referred to as “hybrid amorphous resin”), like the crystalline polyester resin described later. ..

In the above hybrid amorphous resin, the styrene / acrylic resin portion has high compatibility with the amorphous vinyl resin, and the amorphous polyester resin can be uniformly dispersed in the toner matrix particles. When the toner base particles have a core-shell structure and the shell contains an amorphous polyester resin, the toner base particles tend to aggregate on the surface of the core particles containing the amorphous vinyl resin, and the entire surface is easily covered.

In the present invention, "the amorphous polyester resin is modified with the styrene / acrylic resin" means that the amorphous polyester polymerized segment and the styrene / acrylic polymerized segment are chemically bonded. The amorphous polyester polymerized segment refers to a resin portion of the hybrid resin derived from the amorphous poeryster resin, that is, a molecular chain having the same chemical structure as the amorphous polyester resin. The styrene / acrylic polymerized segment refers to a resin portion derived from the styrene / acrylic resin in the hybrid resin, that is, a molecular chain having the same chemical structure as the styrene / acrylic resin. The styrene / acrylic resin can be similarly produced by using the same material as the hybrid crystalline resin described above.

The number average molecular weight (Mn) of the hybrid amorphous polyester resin is more preferably in the range of 2000 to 10000 from the viewpoint of fixability.

The content of the amorphous polyester resin in the toner matrix particles is preferably in the range of 1% by mass or more and less than 50% by mass from the viewpoint of fixability and environmental stability of charging.

[1.2] Release Agent The toner of the present invention contains a release agent.

The release agent is not particularly limited, and various known waxes are used. Specific examples include, for example, polyolefin waxes such as polyethylene wax and polypropylene wax, branched hydrocarbon waxes such as microcrysterin wax, long-chain hydrocarbon waxes such as paraffin wax and sazole wax, and distearyl ketones. Dialkylketone wax, carnauba wax, montan wax, behenyl behenate, trimethylpropantribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecan Ester-based waxes such as diol distearate, tristearyl trimellitic acid, and distealyl maleate, and amide-based waxes such as ethylenediamine behenylamide and tristealylamide trimellitic acid can be used.

The content of the release agent is preferably 0.1 to 30% by mass, more preferably 1 to 15% by mass in the toner. When the amount of the release agent added is 0.1% by mass or more, it is preferable from the viewpoint of suppressing image defects due to poor peeling between the fixing member and the image. Further, when the amount of the release agent added is 30% by mass or less, good image quality can be obtained, which is preferable.

[1.3] Colorant In the toner for electrostatic latent image development of the present invention, as the colorant, various organic or inorganic pigments of various colors as illustrated below can be used, and if necessary. , Two or more colorants may be used in combination for each color.

Specifically, as the colorant for black toner, carbon black, a magnetic material, iron / titanium composite oxide black, or the like can be used. Examples of carbon black include channel black, furnace black, acetylene black, thermal black, lamp black and the like, and examples of the magnetic material include ferrite, magnetite and the like.

As a colorant for yellow toner, C.I. I. Solvent Yellow 2, same 6, same 14, same 15, same 16, same 19, same 21, same 33, same 44, same 56, same 61, same 77, same 79, same 80, same 81, same 82, same 93, 98, 103, 104, 112, 162 and the like can be mentioned, and C.I. I. Pigment Yellow 1, 3, 5, 11, 11, 12, 13, 14, 14, 15, 17, 62, 65, 73, 74, 81, 83, 93, 93, 94, 97, 138, 139, 147, 150, 151, 154, 155, 162, 168, 174, 176, 180, 183, 185, 191 etc. , And mixtures of these can also be used.

As a colorant for magenta toner, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122 and the like can be mentioned as pigments. I. Pigment Red 2, 3, 4, 5, 5, 6, 7, 8, 13, 13, 15, 16, 21, 21, 22, 23, 31, 48: 1, 48 : 2, 48: 3, 48: 4, 49: 1, 53: 1, 57: 1, 60, 63, 63: 1, 64, 68, 81, 83 , 87, 88, 89, 90, 112, 114, 122, 123, 139, 144, 146, 149, 150, 163, 166, 169, 169. 170, 175, 176, 177, 178, 184, 185, 188, 202, 206, 207, 208, 209, 210, 222, 238, 254, The same 255, the same 266, the same 268, the same 269 and the like can be mentioned, and a mixture thereof can also be used.

As a colorant for cyan toner, C.I. I. Examples thereof include Solvent Blue 25, 36, 60, 70, 93, 95, etc., and C.I. I. Pigment Blue 2, 3, 15, 15, 15: 2, 15: 3, 15: 4, 16, 16, 17, 60, 62, 66, etc., and mixtures thereof are also used. be able to.

The content of the colorant is preferably 1 to 30% by mass, more preferably 2 to 20% by mass in the toner.

The number average primary particle size of the colorant is not particularly limited, but is preferably about 10 to 200 nm.

Further, as the colorant, a surface-modified one can also be used. As the surface modifier, conventionally known ones can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be used.

[1.4] Other additives [Charge control agent]
Examples of the charge control agent include niglosin dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes and salicylate metal salts or metal complexes thereof. The charge control agent may be one kind or more.

[Surfactant]
Examples of the above-mentioned surfactants include anionic surfactants such as sulfate ester type, sulfonate type and phosphoric acid ester type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols are included. The above-mentioned surfactant may be one kind or more.

Specific examples of the anionic surfactant include sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium alkylnaphthalene sulfonate, and sodium dialkyl sulfosuccinate. Specific examples of the above-mentioned cationic surfactant include alkylbenzenedimethylammonium chloride, alkyltrimethylammonium chloride, and distearylammonium chloride. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene fatty acid esters.

[1.5] Additives In order to improve the fluidity, chargeability, cleaning properties, etc. of the toner, an external agent such as a so-called post-treatment agent, a fluidizing agent or a cleaning aid, is applied to the surface of the toner matrix particles. Added.

The external additive according to the present invention may be one kind or more. The external additive is not particularly limited, and known ones can be used, for example, silica particles, titania particles, alumina particles, zirconia particles, zinc oxide particles, chromium oxide particles, cerium oxide particles, antimony oxide particles, and oxidation. Tungsten particles, tin oxide particles, tellurium oxide particles, manganese oxide particles and boron oxide particles can be used.
It is more preferable that the external additive contains silica particles produced by the sol-gel method. Silica particles produced by the sol-gel method have a characteristic that the particle size distribution is narrow, and are preferable from the viewpoint of suppressing variations in the adhesion strength of the external additive to the toner matrix particles.

The average number of primary particle diameters of the silica particles is preferably 70 to 200 nm. Silica particles having a number average primary particle size within the above range have a larger particle size than other external additives. Therefore, it has a role as a spacer in the two-component developer. Therefore, it is preferable from the viewpoint of preventing other smaller external additives from being embedded in the toner matrix particles when the two-component developer is agitated in the developing device. It is also preferable from the viewpoint of preventing fusion of toner matrix particles to each other.

The number average primary particle size of the external additive can be obtained, for example, by image processing of an image taken with a transmission electron microscope, and can be adjusted, for example, by classification or mixing of classified products. ..

The surface of the external additive is preferably hydrophobized. A known surface treatment agent is used for the hydrophobization treatment. The surface treatment agent may be one kind or more, and examples thereof include a silane coupling agent, a silicone oil, a titanate-based coupling agent, an aluminate-based coupling agent, a fatty acid, a fatty acid metal salt, or an esterified product thereof. And rosinic acid.

Examples of the silane coupling agent include dimethyldimethoxysilane, hexamethyldisilazane (HMDS), methyltrimethoxysilane, isobutyltrimethoxysilane and decyltrimethoxysilane. Examples of the above silicone oil include cyclic compounds, linear or branched organosiloxanes, and more specifically, organosiloxane oligomers, octamethylcyclotetrasiloxanes, decamethylcyclopentasiloxanes, and tetramethylsane. Cyclotetrasiloxane and tetravinyltetramethylcyclotetrasiloxane are included.

Further, examples of the above-mentioned silicone oil include highly reactive silicone oil in which a modifying group is introduced into the side chain or one end, both ends, one end of the side chain, both ends of the side chain, and the like, and at least the end is modified. .. The type of the modifying group may be one or more, and examples thereof include alkoxy, carboxy, carbinol, higher fatty acid modification, phenol, epoxy, methacryl and amino.

The amount of the external additive added is preferably 0.1 to 10.0% by mass with respect to the entire toner particles. More preferably, it is 1.0 to 3.0% by mass.

[1.6] Physical properties of toner particles [Structure of toner particles]
The toner base particles according to the present invention may have a single-layer structure containing only toner particles, but preferably have a core-shell structure. As a result, low temperature fixability and heat resistant storage can be improved.

The toner matrix particle having a core-shell structure means a toner matrix particle having a multilayer structure including the core particle as a core particle and a shell covering the surface thereof. The shell does not have to cover the entire surface of the core particles, and the core particles may be partially exposed. The cross section of the core-shell structure can be confirmed by a known observation means such as a transmission electron microscope (TEM) and a scanning probe microscope (SPM).
In the case of the core-shell structure, the core particles and the shell can have different characteristics such as glass transition point, melting point, and hardness, and the toner particles can be designed according to the purpose. For example, a resin containing a binder resin, a colorant, a mold release agent, etc., and having a relatively low glass transition point is aggregated and fused to the surface of core particles having a relatively high glass transition point to form a shell. be able to. As described above, an amorphous polyester resin can be used for the shell, and among them, an amorphous polyester resin modified with a styrene / acrylic resin can be preferably used.

[Average particle size of toner particles]
The average particle size of the toner particles preferably has a volume-based median diameter (d50) in the range of 3 to 15 μm, more preferably in the range of 4 to 8 μm, and preferably in the range of 4 to 7 μm. More preferred.

If it is within the above range, high reproducibility can be obtained even with a very small dot image of 1200 dpi level.

The average particle size of the toner particles can be controlled by the concentration of the flocculant used during production, the amount of the organic solvent added, the fusion time, the composition of the binder resin, and the like.

To measure the volume-based median diameter (d50) of toner particles, it is possible to use a measuring device in which a computer system equipped with data processing software Software V3.51 is connected to Multisizer 3 (manufactured by Beckman Coulter). it can.

Specifically, the measurement sample (toner) is added to a surfactant solution (for the purpose of dispersing toner particles, for example, a surfactant solution in which a neutral detergent containing a surfactant component is diluted 10-fold with pure water). After acclimatization, ultrasonic dispersion is performed to prepare a toner particle dispersion solution. This toner particle dispersion is pipetted into a beaker containing ISOTONII (manufactured by Beckman Coulter) in a sample stand until the indicated concentration of the measuring device reaches 8%. Here, by setting this concentration, a reproducible measured value can be obtained. Then, in the measuring device, the number of measured particles is 25,000, the aperture diameter is 100 μm, and the frequency value is calculated by dividing the measurement range of 2 to 60 μm into 256, and the volume integration fraction is 50 from the largest. The particle size of% is obtained as the volume-based median diameter (d50).

[Average circularity of toner particles]
In the static charge image developing toner of the present invention, the average circularity of the toner particles is preferably in the range of 0.930 to 1.000, and more preferably in the range of 0.945 to 0.985. preferable. When the average circularity is within the above range, the crushing of the toner particles can be suppressed, the contamination of the triboelectric charging member can be suppressed, and the chargeability of the toner can be stabilized. In addition, the image formed by the toner has high image quality.

The average circularity can be measured as follows. A toner dispersion is prepared in the same manner as when measuring the median diameter. Using FPIA-2100, FPIA-3000 (both manufactured by Sysmex Co., Ltd.), etc., in the HPF (high-magnification imaging) mode, the toner dispersion was photographed in an appropriate concentration range of 3000 to 10000 HPF detections, and individually. The circularity of the toner particles of No. 1 is calculated by the following formula (y). The average circularity is calculated by adding the circularity of each toner particle and dividing the sum of the circularity by the number of each toner particle. Sufficient reproducibility can be obtained if the number of HPFs detected is in the above-mentioned appropriate concentration range. In the following formula (y), L1 represents the peripheral length (μm) of a circle having the same projected area as the particle image, and L2 represents the peripheral length (μm) of the particle projected image.

Equation (y) Circularity = L1 / L2
[2] Method for producing toner matrix particles When producing the toner of the present invention, the toner matrix particles can be produced, for example, by an emulsion aggregation method.

When the toner matrix particles according to the present invention are produced by the emulsion aggregation method, for example, a dispersion liquid (a) containing crystalline resin fine particles and a dispersion liquid (b) containing amorphous resin fine particles are used as an aqueous medium. A step of preparing a mixed dispersion liquid by adding the mixture to the above, and a step of raising the temperature of the mixed dispersion liquid to agglomerate and fuse the amorphous resin fine particles and the crystalline resin fine particles to form toner matrix particles. In the present specification, the "aqueous medium" means a medium containing at least 50% by mass or more of water, and examples of the components other than water include organic solvents that are soluble in water. For example, methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, dimethylformamide, methyl cellsolve, tetrahydrofuran and the like can be mentioned. Of these, it is preferable to use an alcohol-based organic solvent such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin. Preferably, only water is used as the aqueous medium.

The manufacturing method can be configured to include, for example, the following steps. Here, the following examples describe the case where the crystalline resin fine particles are crystalline polyester resin fine particles and the toner base particles contain a colorant, and the technical scope of the present invention is these. It is not limited to the form of.

(1) Preparation step of a colorant particle dispersion liquid in which colorant particles are dispersed,
(2) Preparation of dispersion liquid (a), in which a crystalline polyester resin is dissolved in an organic solvent, emulsified and dispersed in an aqueous dispersion medium, and the organic solvent is removed to prepare a dispersion liquid containing crystalline polyester resin fine particles. Process,
(3) Preparation step of the dispersion liquid (b), which prepares the dispersion liquid (b) containing the amorphous resin fine particles containing the release agent.
(4) Preparation step of the mixed dispersion liquid, in which each of the dispersion liquids prepared in (1) to (3) above is added to an aqueous medium to prepare a mixed dispersion liquid.
(5) An agglomerated particle forming step of raising the temperature of the mixed dispersion prepared in (4) above to agglomerate amorphous resin fine particles and crystalline resin fine particles to form toner base particles.
(6) A fusion step in which the aggregated particles formed in (5) above are fused by thermal energy to control the shape and obtain toner matrix particles.
(7) Cooling step of cooling the dispersion of toner matrix particles,
(8) A filtration / cleaning step of filtering out toner matrix particles from an aqueous medium and removing a surfactant or the like from the toner matrix particles.
(9) A drying step of drying the washed toner matrix particles.

In carrying out each of the above-mentioned steps, conventionally known findings can be appropriately referred to.

For example, the dispersion liquid (a) containing the crystalline resin fine particles and the dispersion liquid (b) containing the amorphous resin fine particles described above are prepared by using various emulsification methods such as a method of emulsifying by a mechanical shearing force. However, it is preferable to prepare using a method called a phase inversion emulsification method. In particular, when the dispersion liquid (a) prepared by the phase inversion emulsification method is used, oil droplets can be uniformly dispersed by changing the stability of the carboxy group of the polyester, as in the mechanical emulsification method. It is excellent in that it does not disperse by forcibly shearing force. In the "phase inversion emulsification method", a dissolution step of dissolving a resin in an organic solvent to obtain a resin solution, a neutralization step of adding a neutralizing agent to the resin solution, and an aqueous dispersion of the neutralized resin solution. A dispersion of resin fine particles can be obtained by going through an emulsification step of emulsifying and dispersing in a medium to obtain a resin emulsion and a desolvation step of removing an organic solvent from the resin emulsion.

The particle size of the resin fine particles in the dispersion can be controlled by changing the amount of the neutralizing agent added. The average particle size of the crystalline resin fine particles is preferably 100 to 300 nm as a volume-based median diameter. The method for measuring the average particle size is as described in Examples described later.

Further, by using the above-mentioned toner matrix particles as a core and providing a shell layer on the surface thereof, the toner matrix particles having a core-shell structure can be obtained. By adopting a core-shell structure, heat-resistant storage and low-temperature fixability can be further improved.

In order to produce toner matrix particles having a core-shell structure, for example, in the above-mentioned production method, after the agglomerated particle forming step of (5) above, the following steps:
(5') Using the toner matrix particles prepared in (5) above as core particles, the shell dispersion liquid (c) containing amorphous resin fine particles is added to the mixed dispersion liquid, and a shell is formed on the surface of the core particles. The step of forming the above (6) may be carried out, and then the steps of (6) and subsequent steps may be carried out.

[Preparation process of colorant particle dispersion]
(Preparation method of pigment particle dispersion)
When a pigment is used as a colorant, when the pigment particles are dispersed in an aqueous medium, an aqueous medium dispersion of the pigment particles is prepared, and the dispersion and the aqueous medium dispersion of the resin particles are used. , It is preferable to perform aggregation and fusion.

The water-based medium used when preparing the water-based medium dispersion liquid of the pigment particles is as described above, and in this water-based medium, a surfactant, resin fine particles, etc. are contained for the purpose of improving the dispersion stability. It may be added.

The dispersion of the pigment particles can be performed by utilizing mechanical energy, and the disperser is not particularly limited as such, and as mentioned above, the low speed shear type disperser and the high speed shear type are used. Examples thereof include a disperser, a friction type disperser, a high pressure jet type disperser, an ultrasonic disperser, and a high pressure impact type disperser Ultimizer. Specific examples thereof include Sugino Machine Co., Ltd. and HJP30006. be able to.

[Preparation process of binder resin particle dispersion containing mold release agent]
As a method for preparing the binder resin particle dispersion liquid containing the release agent, an emulsion polymerization method and a miniemulsion method are preferable.

For example, the polymerizable monomer constituting the binder resin and the release agent are mixed to prepare a mixed solution, and the aqueous medium to which the surfactant and the polymerization initiator are added is heated and contained in the heated aqueous medium. The above mixture is added to the mixture. Then, the binder resin particles containing the release agent can be obtained by mixing and dispersing by mechanically stirring and emulsion-polymerizing the polymerizable monomer.

Further, if necessary, a step of adding a polymerizable monomer or a mixed solution of the polymerizable monomer and the release agent to the binding resin particles containing the obtained release agent to polymerize the polymerizable monomer. By repeating the above steps, the binder resin particles containing the release agent having a core-shell structure can be obtained.

When the polymerizable monomer is mixed with an aqueous medium or polymerized, the polymerizable monomer is well dispersed and the polymerization is carried out while stirring using mechanical energy so that the polymerization proceeds smoothly. Is preferable. Equipment that imparts such mechanical energy includes a homogenizer, a low-speed shearing disperser, a high-speed shearing disperser, a friction disperser, a high-pressure jet disperser, an ultrasonic disperser, a high-pressure impact disperser, and an Ultima. Dispersers such as shears can be mentioned.

The polymerization of the polymerizable monomer can be carried out at normal pressure, reduced pressure, or pressurization, but is preferably carried out at normal pressure (or its vicinity, usually ± 10 mmHg). The polymerization temperature is not particularly limited and can be appropriately selected as long as the polymerization of the polymerizable monomer proceeds. The polymerization temperature is, for example, preferably 50 ° C. or higher and 150 ° C. or lower, and more preferably 60 ° C. or higher and 130 ° C. or lower. Further, the polymerization time can be appropriately selected within the range in which the polymerization of the polymerizable monomer proceeds, and is preferably 0.5 to 5 hours, preferably 0.5 to 3 hours, for example. More preferred.

The order of adding the polymerizable monomer and the polymerization initiator to the aqueous medium is not particularly limited. (1) After adding the polymerization initiator to the aqueous medium, the polymerizable monomer (additive) ) May be added, or (2) a method of adding a polymerizable monomer (mixture) to an aqueous medium and then adding a polymerization initiator may be used.

In the first-stage polymerization, when a mold release agent is not included, from the viewpoint of convenience, (1) a method of adding a polymerization initiator to an aqueous medium and then adding a polymerizable monomer (mixture) is possible. It is more preferable to add the polymerizable monomer (mixture) while dropping it.

On the other hand, in the first stage polymerization, when the release agent is dispersed together with the monomer, (2) the polymerizable monomer (mixture) and the release agent are added to the aqueous medium, and then the polymerization initiator is added. The method of addition is preferable. In order to improve the dispersibility of the release agent, it is preferable to add a mixture of the release agent and the first polymerizable monomer to an aqueous medium, and then apply mechanical energy to stir the mixture. It is preferable to use a disperser such as a low-speed shear disperser, a high-speed shear disperser, a friction disperser, a high-pressure jet disperser, an ultrasonic disperser, a high-pressure impact disperser, and an ultimateizer. A commercially available product can also be used as the disperser, and for example, "CLEARMIX" (manufactured by M Technique Co., Ltd.) can be used. At the time of emulsion polymerization, it is preferable to emulsify and disperse the first polymerizable monomer and the release agent by using a surfactant.

The surfactant is not particularly limited, but for example, the following ionic surfactants can be used as preferable ones. Ionic surfactants include sulfonates, sulfate ester salts, fatty acid salts and the like, and sulfonates include, for example, sodium dodecylbenzenesulfonate, sodium arylalkylpolyether sulfonate, 3,3-disulfonediphenyl. Urea-4,4-diazo-bis-amino-8-naphthol-6-sodium sulfonate, o-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4 -Diazo-bis-β-naphthol-6-sodium sulfonate and the like.

Sulfate ester salts include, for example, sodium dodecyl sulfate, sodium lauryl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc., and fatty acid salts include sodium oleate, sodium laurate, sodium capricate, capric acid. There are sodium, sodium caproate, potassium stearate, calcium oleate, sodium polyoxyethylene-2-dodecyl ether sulfate and the like.

As the surfactant, a nonionic surfactant can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and a higher fatty acid, and an alkylphenol polyethylene oxide. , Higher fatty acids and polypropylene oxide esters, sorbitan esters, etc.

These surfactants may be used alone or in combination of two or more.

(Chain transfer agent)
A known chain transfer agent can also be used to adjust the molecular weight of the binder resin. Specific examples thereof include octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionic acid ester, turbinolene, carbon tetrabromide, α-methylstyrene dimer and the like.

(Polymer initiator)
The polymerization of the polymerizable monomer is preferably carried out in the presence of a radical polymerization agent.

The polymerization initiator used when polymerizing the polymerizable monomer is not particularly limited, and a known polymerization initiator can be used. When the resin fine particles are formed by the emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble radical polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, and hydrogen peroxide. In this embodiment, potassium persulfate (KPS) is more preferable because the emulsion polymerization method is preferably used.

The amount of the polymerization initiator added is appropriately set so that the polymerization proceeds, but it is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer at the time of polymerization.

(Resin fine particles)
The volume average particle diameter of the resin fine particles obtained by the polymerization is preferably 50 to 400 nm, more preferably 60 to 200 nm.

[Agglomeration process and fusion process]
In the agglomeration step (above agglomeration particle forming step), the binder resin particle dispersion liquid containing the release agent, the crystalline polyester resin particle dispersion liquid, and the colorant dispersion liquid are put into an aqueous medium and mixed and dispersed. The liquid is adjusted, and a flocculant is added to the mixed dispersion to coagulate the binder resin particles, the crystalline polyester resin particles, and the colorant containing the release agent.

In order to impart cohesiveness, it is preferable to add a base such as an aqueous solution of sodium hydroxide to the dispersion of the resin fine particles in advance to adjust the pH to 9 to 12 before adding the cohesive agent.

Then, a flocculant is added to the dispersion. The addition temperature and the addition rate are not particularly limited, but it is preferable to add the mixture at 25 to 35 ° C. for 5 to 15 minutes with stirring.

The flocculant that can be used is not particularly limited, but one selected from metal salts is preferably used. For example, there are salts of divalent metals such as calcium, magnesium, manganese, zinc and copper, salts of trivalent metals such as iron and aluminum, and the like. Specific examples of the salt include calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate and the like. The above-mentioned flocculants may be used alone or in combination of two or more.

The amount of the flocculant used is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the total solid content in the dispersion.

When aggregating, it is preferable to keep the standing time (time until the start of heating) of leaving the dispersion liquid after adding the aggregating agent as short as possible. The leaving time is usually 30 minutes or less, preferably 10 minutes or less, and more preferably 2 to 6 minutes. The temperature at which the flocculant is added is not particularly limited, but is preferably equal to or lower than the glass transition temperature of the binder resin.

When aggregating, it is preferable to heat and raise the temperature. The heating temperature is preferably in the range of 70 to 95 ° C., and the heating rate is preferably in the range of 1 to 15 ° C./min.

When the agglomerated particles have a desired particle size, the agglutination of various particles in the reaction system may be stopped. Agglutination is stopped by adding a chelate compound whose pH can be adjusted or an agglutination stop agent such as an inorganic salt compound such as sodium chloride. The volume-based median diameter can be measured by, for example, a Coulter Multisizer 3 manufactured by Coulter Beckman.

The fusing step is a step of fusing the agglomerated particles obtained in the above-mentioned agglutination step, and is preferably performed at a temperature equal to or higher than the glass transition temperature of the binder resin. Then, after reaching a temperature equal to or higher than the glass transition temperature of the binder resin, the temperature of the dispersion liquid is maintained for a certain period of time to continue the fusion. Thereby, the growth of the particles (aggregation of the resin particles) and the fusion of the resin particles in the agglomerated particles can be effectively promoted. The holding time may be such that fusion is performed, and the holding time may be about 0.5 to 10 hours at the maximum temperature at the time of fusion.

The aggregation step and the fusion step are preferably performed until the toner matrix particles have a desired volume-based median diameter or circularity. The growth of the toner matrix particles can be stopped by adding an aqueous sodium chloride solution or the like.

In the step of obtaining the toner base particles, it is preferable to perform a step of aggregating and fusing the resin particles containing the release agent a plurality of times. By performing the steps of aggregating and fusing a plurality of times, the toner matrix particles have a multi-layer structure, and the release agent can be dispersed at an appropriate position in the toner matrix particles.

[Cooling process]
In the cooling step after the fusion step, it is preferable to cool to 0 to 45 ° C.

The fused particles obtained by fusion can be made into toner base particles through a solid-liquid separation step such as filtration, and if necessary, a washing step and a drying step.

[Filtration / cleaning process]
In this filtration / cleaning step, the toner matrix particles are solid-liquid separated from the cooled toner matrix particles using a solvent such as water, and the toner matrix particles are filtered out. A cleaning treatment is performed to remove deposits such as a surfactant from the toner matrix particles (cake-like aggregates). Specific examples of the solid-liquid separation and washing methods include a centrifugal separation method, a vacuum filtration method using an ejector, a nutche, etc., a filtration method using a filter press, etc., and these are particularly limited. is not. In this filtration / cleaning step, pH adjustment, pulverization, etc. may be performed as appropriate. Such an operation may be repeated.

[Drying process]
In this drying step, the washed toner matrix particles are dried. The dryers used in this drying process include ovens, spray dryers, vacuum freeze dryers, vacuum dryers, stationary shelf dryers, mobile shelf dryers, fluidized layer dryers, rotary dryers, and stirrers. Examples thereof include a dryer, and these are not particularly limited. The amount of water in the dried particles measured by the Karl Fischer titration method is preferably 5% by mass or less, and more preferably 2% by mass or less.

Further, when the dried particles are aggregated by a weak intermolecular attractive force to form an agglomerate, the agglomerate may be crushed. Here, as the crushing processing device, a mechanical crushing device such as a jet mill, a co-mill, a Henschel mixer, a coffee mill, or a food processor can be used.

[3] Developer for Electrostatic Image Development The toner is composed of the toner particles themselves if it is a one-component developer, and is composed of the toner particles and carrier particles if it is a two-component developer. The content (toner concentration) of the toner particles in the two-component developer may be the same as that of a normal two-component developer, and is, for example, 4.0 to 8.0% by mass.

The carrier particles are made of a magnetic material. Examples of the carrier particles include a coated carrier particle having a core material particle made of the magnetic material and a layer of a coating material covering the surface thereof, and a resin dispersion in which fine powder of the magnetic material is dispersed in a resin. Mold carrier particles, are included. The carrier particles are preferably coated carrier particles from the viewpoint of suppressing adhesion of the carrier particles to the photoconductor.

The core particles are composed of a magnetic material, for example, a substance that is strongly magnetized in that direction by a magnetic field. The magnetic material may be one kind or more, and examples thereof include metals exhibiting ferromagnetism such as iron, nickel and cobalt, alloys or compounds containing these metals and alloys exhibiting ferromagnetism by heat treatment. Is included.

Examples of the metal exhibiting ferromagnetism or a compound containing the same include iron, ferrite represented by the following formula (a) and magnetite represented by the following formula (b). M in the formulas (a) and (b) represents one or more monovalent or divalent metals selected from the group of Mn, Fe, Ni, Co, Cu, Mg, Zn, Cd and Li.

Equation (a): MO · Fe ₂ O ₃
Equation (b): MFe ₂ O ₄
Further, examples of alloys or metal oxides that exhibit ferromagnetism by the above heat treatment include Whistler alloys such as manganese-copper-aluminum and manganese-copper-tin, and chromium dioxide.

The core material particles are preferably ferrite. This is because the specific gravity of the coated carrier particles is smaller than the specific gravity of the metal constituting the core material particles, so that the impact force of stirring in the developing apparatus can be made smaller.

The coating material may be one kind or more. As the coating material, a known resin used for coating the core material particles of the carrier particles can be used. The coating material is preferably a resin having a cycloalkyl group from the viewpoint of reducing the water adsorption property of the carrier particles and improving the adhesion of the coating layer to the core material particles. Examples of the cycloalkyl group include a cyclohexyl group, a cyclopentyl group, a cyclopropyl group, a cyclobutyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group and a cyclodecyl group. Of these, a cyclohexyl group or a cyclopentyl group is preferable, and a cyclohexyl group is more preferable from the viewpoint of adhesion between the coating layer and the ferrite particles.

The weight average molecular weight of the resin having a cycloalkyl group is, for example, 1000 to 800,000, more preferably 100,000 to 750000. The content of the cycloalkyl group in the resin is, for example, 10 to 90% by mass. The content of the cycloalkyl group in the resin can be determined by using a known instrumental analysis method such as P-GC / MS or ¹ H-NMR.

The two-component developer can be produced by mixing an appropriate amount of the toner particles and the carrier particles. Examples of mixers used for such mixing include Nauter mixers, W cones and V-type mixers.

Further, the size and shape of the carrier particles can also be appropriately determined within the range in which the effects of the present embodiment can be obtained. For example, the volume average particle diameter of the carrier particles is preferably in the range of 15 to 100 μm, more preferably in the range of 20 to 60 μm. The volume average particle size of the carrier particles can be measured wet by using, for example, a laser diffraction type particle size distribution measuring device "HELOS KA" (manufactured by Symboltec). Further, the volume average particle size of the carrier particles is adjusted by, for example, a method of controlling the particle size of the core material particles according to the production conditions of the core material particles, classification of the carrier particles, mixing of the classified products of the carrier particles, and the like. Is possible.

[3] Electrophotographic image forming method and apparatus The electrophotographic image forming method used in the present invention is an image forming method having at least a latent image forming step, a developing step, an intermediate transfer step, a transfer step, a fixing step, and a cleaning step. It is characterized by using the static charge image developing toner of the present invention.

That is, the electrophotographic image forming method of the present invention has the following steps.

1) The charging process of charging the surface of the electrostatic charge image carrier and
2) A latent image forming step of forming an electrostatic latent image on the electrostatic charge image carrier by exposing the surface of the electrostatic charge image carrier.
3) A developing process in which the electrostatic latent image is visualized with a developer containing a toner for developing an electrostatic charge image to form a toner image.
4) An intermediate transfer step of transferring the toner image onto the intermediate transfer body, a transfer step of transferring the toner image to the image forming support, and
5) The fixing step of the toner image formed on the image forming support and
6) A cleaning step of removing the residual electrostatic charge image developing toner using a cleaning blade, and
Have.

The electrostatic charge image carrier (electrophotographic photosensitive member, also simply referred to as a photosensitive member) can be used in various known image forming methods of the electrophotographic method. For example, it can be used in a monochrome image forming method or a full-color image forming method. In the full-color image forming method, a four-cycle image forming method composed of four types of color developing devices for each of yellow, magenta, cyan, and black and one photoconductor, and color developing for each color. Any image forming method can be used, such as a tandem image forming method in which an image forming unit having an apparatus and a photoconductor is mounted for each color.

Specifically, the electrophotographic image forming method of the present invention is formed by using the photoconductor, charging the photoconductor with a charging device (charging step), and exposing the image (exposure step). The electrostatic latent image is developed (development process) using a developing device to visualize it and obtain a toner image. This toner image is transferred (transfer step) onto a transfer medium such as copy paper or a transfer belt, and then a static elimination step is performed, and then the next image formation cycle is performed. The toner image transferred on a transfer medium such as a transfer belt is transferred onto the copy paper, and the toner image transferred on the copy paper is fixed (fixed step) on the copy paper by a fixing process such as a contact heating method. To obtain a visible image. After the transfer step, the toner (transfer residual toner) remaining on the photoconductor is removed (cleaning step) by a cleaning blade (rubber blade) or the like. This cleaning step may be performed before or after the static elimination step, but when the static elimination step is static elimination by light irradiation, the toner remaining on the photoconductor absorbs the static elimination light after the cleaning step. It is preferable because it does not interfere with it and can effectively eliminate static electricity.

Since the photoconductor has a curable surface layer, there are advantages such as improvement in the durability of the photoconductor, but since the surface layer of the photoconductor is hard to be scraped, filming or the like may occur on the surface of the photoconductor. When a developer that is likely to occur is used, image defects may occur. By using the toner for static charge image development of the present invention, it is possible to suppress the occurrence of filming of the photoconductor, and the frequency of replacement of the photoconductor unit due to filming or wear of the blade is also reduced. It is possible to maximize the advantage of using the photoconductor of the curable surface layer.

The curable surface layer is formed on the outer peripheral surface on the outer peripheral surface of the photoconductor, and contains metal oxide fine particles such as antimony-doped tin oxide, titanium oxide, zinc oxide, nickel, copper, silver, and germanium (meth). ) The coating film of the coating liquid for forming a surface layer containing an acrylate monomer and an active energy ray-curable composition containing a polyfunctional (meth) acrylate other than the (meth) acrylate monomer is irradiated with active energy rays. It is preferably obtained by curing.

It is preferable that the metal oxide fine particles are composed of surface-treated metal oxide fine particles.

[Electrophotograph image forming apparatus]
Next, a specific electrophotographic image forming method will be described using an electrophotographic image forming apparatus.

The electrophotographic image forming apparatus uses a charging means for charging the photoconductor with a charging device, an exposure means for forming an electrostatic latent image formed by image exposure, and a developing device. It has a developing means for obtaining a toner image by visualizing the toner image, a transfer means for transferring the toner image onto a transfer medium such as a paper or a transfer belt, and a static elimination means. The toner image directly transferred onto the copy paper and the toner image transferred onto the paper via a transfer medium such as a transfer belt obtain a visible image by a fixing means fixed to the copy paper by a fixing process such as a contact heating method. After the transfer, the toner remaining on the photoconductor (transfer residual toner) is removed by a cleaning means such as a cleaning blade.

FIG. 2 is a schematic cross-sectional view showing the structure of a tandem type electrophotographic image forming apparatus including the electrophotographic photosensitive member of the present invention.

The image forming apparatus 300 shown in FIG. 2 is referred to as a tandem type color image forming apparatus, and includes four sets of image forming units (image forming units) 10Y, 10M, 10C, 10K, an intermediate transfer body unit 70, and a supply. It is composed of a paper means 21 and a fixing means 24. A document image reading device SC is arranged above the main body A of the electrophotographic image forming device.

The four image forming units 10Y, 10M, 10C, and 10K rotate around the photoconductors 1Y, 1M, 1C, and 1K with the charging means 2Y, 2M, 2C, and 2K, and the exposure means 3Y, 3M, 3C, and 3K. From the developing means 4Y, 4M, 4C, 4K, the primary transfer rollers 5Y, 5M, 5C, 5K as the primary transfer means, and the cleaning means 6Y, 6M, 6C, 6K for cleaning the photoconductors 1Y, 1M, 1C, 1K. It is configured.

The electrophotographic image forming apparatus uses the photoconductors 1Y, 1M, 1C, and 1K, respectively. The photoconductor has an advantage that the durability of the photoconductor is improved when the surface layer is a curable surface layer, but the surface layer of the photoconductor is hard to be scraped, so that the surface of the photoconductor is filmed. Image defects may occur when a developing agent that is prone to generate is used, but the occurrence of filming of the photoconductor can be suppressed by using the static charge image developing toner and developing agent of the present application. It is possible to reduce the frequency of replacement of the photoconductor unit due to filming, wear of the blade, etc., and it is possible to maximize the advantage of using the photoconductor of the curable surface layer.

The image forming units 10Y, 10M, 10C, and 10K have the same configuration except that the toner colors provided are different, such as yellow (Y) color, magenta (M) color, cyan (C) color, and black (K) color, respectively. Is. Therefore, in the following, the image forming unit 10Y will be described in detail as an example.

The image forming unit 10Y has a charging means 2Y, an exposure means 3Y, a developing means 4Y, and a cleaning means 6Y around the photoconductor 1Y which is an image forming body, and a yellow (Y) toner image is formed on the photoconductor 1Y. It is what forms.

The charging means 2Y is a means for uniformly charging the surface of the photoconductor 1Y to a negative electrode property. In the electrophotographic image forming apparatus of the present embodiment, it is preferable to use a charging roller as the charging means 2Y.

The exposure means 3Y is a means for forming an electrostatic latent image corresponding to a yellow image by exposing the photoconductor 1Y to which a uniform potential is applied by the charging means 2Y based on an image signal (yellow). is there. As the exposure means 3Y, one composed of LEDs and imaging elements in which light emitting elements are arranged in an array in the axial direction of the photoconductor 1Y, a laser optical system, or the like is used.

The developing means 4Y comprises, for example, a developing sleeve 41Y having a built-in magnet and rotating while holding a developer, and a voltage applying device for applying a DC and / or AC bias voltage between the developing sleeve and the photoconductor. is there.

The developing means 4Y comprises, for example, a developing sleeve having a built-in magnet and rotating while holding a developer, and a voltage applying device for applying a DC and / or AC bias voltage between the developing sleeve and the photoconductor. ..

The fixing means 24 is, for example, a heat roller fixing composed of a heating roller having a heating source inside and a pressure roller provided in a state of being pressure-contacted so as to form a fixing nip portion on the heating roller. There is a method.

The cleaning means 6Y is composed of a cleaning blade and a brush roller provided on the upstream side of the cleaning blade.

The image forming apparatus 300 is configured by integrally coupling a photoconductor and components such as a developing means and a cleaning means as a process cartridge (image forming unit), and the image forming unit can be detachably attached to and detached from the apparatus main body. It may be configured. Further, at least one of a charging means, an exposure means, a developing means, a transfer means, and a cleaning means is integrally supported together with a photoconductor to form a process cartridge (image forming unit), and a detachable single image is formed on the apparatus main body. The unit may be detachable by using a guide means such as a rail of the main body of the device.

The intermediate transfer unit 70 has an endless belt-shaped intermediate transfer 77 as a semi-conductive endless belt-shaped second image carrier that is wound by a plurality of rollers and rotatably supported.

Images of each color formed by the image forming units 10Y, 10M, 10C and 10K are sequentially transferred onto the rotating endless belt-shaped intermediate transfer body 77 by the primary transfer rollers 5Y, 5M, 5C and 5K as the primary transfer means. To form a composite color image. The transfer material (image support for carrying the fixed final image: plain paper, transparent sheet, etc.) P housed in the paper feed cassette 20 is fed by the paper feed means 21, and the plurality of intermediate rollers 22A, It is conveyed to the secondary transfer roller 5b as the secondary transfer means via the 22B, 22C, 22D, and the resist roller 23, and is secondarily transferred onto the transfer material P to collectively transfer the color image. The transfer material P to which the color image is transferred is fixed by the fixing means 24, sandwiched between the paper ejection rollers 25, and placed on the paper ejection tray 26 outside the machine. Here, the transfer support of the toner image formed on the photoconductor such as the intermediate transfer body or the transfer material is collectively referred to as a transfer medium.

On the other hand, after the color image is transferred to the transfer material P by the secondary transfer roller 5b as the secondary transfer means, the residual toner is removed from the endless belt-shaped intermediate transfer body 77 in which the transfer material P is curvature-separated by the cleaning means 6b. Toner.

During the image forming process, the primary transfer roller 5K is always in contact with the photoconductor 1K. The other primary transfer rollers 5Y, 5M and 5C abut on the corresponding photoconductors 1Y, 1M and 1C only during color image formation.

The secondary transfer roller 5b comes into contact with the endless belt-shaped intermediate transfer body 77 only when the transfer material P passes through the transfer material P and the secondary transfer is performed.

Further, the housing 80 can be pulled out from the device main body A via the support rails 82L and 82R.

The housing 80 includes image forming units 10Y, 10M, 10C and 10K, and an intermediate transfer unit 70.

The image forming portions 10Y, 10M, 10C and 10K are arranged in columns in the vertical direction. The intermediate transfer unit 70 is arranged on the left side in the drawing of the photoconductors 1Y, 1M, 1C and 1K. The intermediate transfer unit 70 includes an endless belt-shaped intermediate transfer 77 that can be rotated around rollers 71, 72, 73, and 74, primary transfer rollers 5Y, 5M, 5C, and 5K, and cleaning means 6b.

By using the toner for static charge image development of the present invention as the toner used in the above-mentioned image forming apparatus, high transfer efficiency, high image quality, and cleanability are improved while achieving low temperature fixability. , Filming of the photoconductor and the occurrence of scratches can be reduced.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, the indication of "parts" or "%" is used, but unless otherwise specified, it indicates "parts by mass" or "% by mass".

Example 1
<Making toner>
(1) Preparation of styrene-acrylic copolymer resin fine particle dispersion (a) Preparation of resin fine particle dispersion 1O Anionic surfactant: in a reaction vessel equipped with a stirrer, temperature sensor, cooling tube, and nitrogen introduction device. A surfactant solution was prepared by dissolving 7.08 parts by mass of sodium dodecyl sulfate in 3010 parts by mass of ion-exchanged water. The temperature inside the reaction vessel was raised to 80 ° C. while stirring the surfactant solution under a nitrogen stream at a stirring speed of 230 rpm.

Next, a polymerization initiator solution prepared by dissolving 9.2 parts by mass of a polymerization initiator: potassium persulfate (KPS) in 200 parts by mass of ion-exchanged water was added to the surfactant solution, and the temperature inside the reaction vessel was raised to 75 ° C. After
・ 74.4 parts by mass of styrene ・ 23.3 parts by mass of n-butyl acrylate ・ 2.3 parts by mass of methacrylic acid The mixed solution 1 is added dropwise over 1 hour, and further stirred at 75 ° C. for 2 hours. And polymerized to prepare a resin fine particle dispersion liquid 1O in which the resin fine particle 1O was dispersed.

(B) Preparation of resin fine particle dispersion 1OP In a flask equipped with a stirrer,
・ Styrene 112.1 parts by mass ・ n-Butyl acrylate 24.7 parts by mass ・ Methacrylic acid 3.22 parts by mass ・ n-octyl-3-mercaptopropionic acid ester 5.6 parts by mass was added, and further
-Pentaerythritol tetrabehenate 80.4 parts by mass was added and heated to 90 ° C. to prepare a mixed solution 2 in which the above compounds were mixed.

On the other hand, a surfactant solution prepared by dissolving 1.6 parts by mass of sodium dodecyl sulfate in 2700 parts by mass of ion-exchanged water was prepared in a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device. The mixture was heated to 98 ° C., 28 parts by mass of the above resin fine particle dispersion 1O was added to the surfactant solution in terms of solid content, and then the mixed solution 2 was added. Further, a dispersion liquid (emulsified liquid) was prepared by mixing and dispersing for 2 hours using a mechanical dispersion device "CLEARMIX" (manufactured by M Technique Co., Ltd.) having a circulation path.

Next, an initiator solution prepared by dissolving 5.1 parts by mass of potassium persulfate (KPS) in 240 parts by mass of ion-exchanged water and 750 parts by mass of ion-exchanged water were added to the emulsion, and the reaction system was heated at 98 ° C. Polymerization was carried out by stirring for 2 hours to prepare a resin fine particle dispersion solution 1OP in which the resin fine particle 1OP having a composite structure in which the surface of the resin fine particles 1O was coated with a resin layer was dispersed.

(C) Preparation of resin fine particle dispersion 1OPQ (styrene-acrylic copolymer resin fine particle dispersion A)
An initiator solution prepared by dissolving 7.4 parts by mass of potassium persulfate (KPS) in 200 parts by mass of ion-exchanged water was added to the above resin fine particle dispersion 1OP to adjust the temperature to 80 ° C.
・ 322 parts by mass of styrene ・ 68 parts by mass of n-butyl acrylate ・ 9.21 parts by mass of methacrylic acid ・ 10.4 parts by mass of n-octyl-3-mercaptopropionic acid ester A mixed solution 3 in which 10.4 parts by mass is mixed over 1 hour. Then, the polymer is polymerized by heating and stirring for 2 hours while maintaining the temperature at 80 ° C., and then the reaction system is cooled to 28 ° C. to coat the surface of the resin fine particles 1OP with a resin layer. A styrene-acrylic copolymer resin fine particle dispersion A in which 1 OPQ of resin fine particles having a structure was dispersed was prepared.

(D) Preparation of Resin Fine Particle Dispersion Liquid 2OP The resin fine particle dispersion liquid 2OP was prepared in the same manner except that pentaerythritol tetrabehenate was set to 0 parts by mass in the preparation of the resin fine particle 1OP.

(E) Preparation of resin fine particle dispersion 2OPQ (styrene-acrylic copolymer resin fine particle dispersion B)
A styrene-acrylic copolymer resin fine particle dispersion B in which the resin fine particle 2OPQ was dispersed was prepared in the same manner except that the resin particle dispersion 1OP was changed to 2OP in the preparation of the resin fine particle 1OPQ.

(F) Preparation of Resin Fine Particle Dispersion Liquid 3O The resin fine particle dispersion liquid 3O was prepared in the same manner except that styrene was 77.5 parts by mass and n-butyl acrylate was 20.2 parts by mass in the preparation of the resin fine particle 1O. ..

(G) Preparation of Resin Fine Particle Dispersion Liquid 3OP The same applies except that styrene was 115.0 parts by mass, n-butyl acrylate was 21.8 parts by mass, and the resin particle dispersion liquid 1O was 3O in the preparation of the resin fine particle 1OP. 3 OP of resin fine particle dispersion was prepared.

(H) Preparation of resin fine particle dispersion 3OPQ (styrene-acrylic copolymer resin fine particle dispersion C)
In the preparation of the resin fine particle 1OPQ, the resin fine particle 3OPQ was dispersed in the same manner except that styrene was changed to 330.0 parts by mass, n-butyl acrylate was changed to 60.0 parts by mass, and the resin particle dispersion liquid 1OP was changed to 3OP. A styrene-acrylic copolymer resin fine particle dispersion C was prepared.

(I) Preparation of Resin Fine Particle Dispersion Liquid 4OP The resin fine particle dispersion liquid 4OP was prepared in the same manner except that pentaerythritol tetrabehenate was set to 0 parts by mass in the preparation of the resin fine particle 3OP.

(J) Preparation of resin fine particle dispersion 4OPQ (styrene-acrylic copolymer resin fine particle dispersion D)
A styrene-acrylic copolymer resin fine particle dispersion D in which the resin fine particle 4OPQ was dispersed was prepared in the same manner except that the resin particle dispersion 3OP was changed to 4OP in the preparation of the resin fine particle 3OPQ.

(K) Preparation of Resin Fine Particle Dispersion Liquid 5O The resin fine particle dispersion liquid 5O was prepared in the same manner except that styrene was 72.0 parts by mass and n-butyl acrylate was 25.7 parts by mass in the preparation of the resin fine particle 1O. ..

(L) Preparation of Resin Fine Particle Dispersion Liquid 5OP The same applies except that styrene was 109.0 parts by mass, n-butyl acrylate was 27.8 parts by mass, and the resin particle dispersion 1O was 5O in the preparation of the resin fine particle 1OP. To prepare a resin fine particle dispersion 5OP.

(M) Preparation of resin fine particle dispersion 5OPQ (styrene-acrylic copolymer resin fine particle dispersion E)
In the preparation of the resin fine particle 1OPQ, the resin fine particle 5OPQ was dispersed in the same manner except that styrene was changed to 312.5 parts by mass, n-butyl acrylate was changed to 77.5 parts by mass, and the resin particle dispersion liquid 1OP was changed to 5OP. A styrene-acrylic copolymer resin fine particle dispersion E was prepared.

(N) Preparation of Resin Fine Particle Dispersion Liquid 6OP The resin fine particle dispersion liquid 6OP was prepared in the same manner except that pentaerythritol tetrabehenate was set to 0 parts by mass in the preparation of the resin fine particle 5OP.

(O) Preparation of resin fine particle dispersion 6OPQ (styrene-acrylic copolymer resin fine particle dispersion F)
A styrene-acrylic copolymer resin fine particle dispersion F in which the resin fine particle 6OPQ was dispersed was prepared in the same manner except that the resin particle dispersion 5OP was changed to 6OP in the preparation of the resin fine particle 5OPQ.

(P) Preparation of Resin Fine Particle Dispersion Liquid 7O The resin fine particle dispersion liquid 7O was prepared in the same manner except that styrene was 86.5 parts by mass and n-butyl acrylate was 11.2 parts by mass in the preparation of the resin fine particle 1O. ..

(Q) Preparation of Resin Fine Particle Dispersion Solution 7OP The same applies except that styrene was made 124.0 parts by mass, n-butyl acrylate was made 12.8 parts by mass, and the resin particle dispersion 1O was made 7O in the preparation of the resin fine particle 1OP. 7 OP of resin fine particle dispersion was prepared.

(R) Preparation of resin fine particle dispersion 7OPQ (styrene-acrylic copolymer resin fine particle dispersion G)
In the preparation of the resin fine particle 1OPQ, the resin fine particle 7OPQ was dispersed in the same manner except that styrene was changed to 352.5 parts by mass, n-butyl acrylate was changed to 37.5 parts by mass, and the resin particle dispersion liquid 1OP was changed to 7OP. A styrene-acrylic copolymer resin fine particle dispersion G was prepared.

(S) Preparation of Resin Fine Particle Dispersion Liquid 8OP A resin fine particle dispersion liquid 8OP was prepared in the same manner except that pentaerythritol tetrabehenate was set to 0 parts by mass in the preparation of the resin fine particle 7OP.

(T) Preparation of resin fine particle dispersion 8OPQ (styrene-acrylic copolymer resin fine particle dispersion H)
A styrene-acrylic copolymer resin fine particle dispersion H in which the resin fine particle 8OPQ was dispersed was prepared in the same manner except that the resin particle dispersion 7OP was changed to 8OP in the preparation of the resin fine particle 7OPQ.

(U) Preparation of Resin Fine Particle Dispersion Liquid 9O The resin fine particle dispersion liquid 9O was prepared in the same manner except that styrene was 75.0 parts by mass and n-butyl acrylate was 22.7 parts by mass in the preparation of the resin fine particle 1O. ..

(V) Preparation of Resin Fine Particle Dispersion Solution 9OP The same applies except that styrene was 105.0 parts by mass, n-butyl acrylate was 31.8 parts by mass, and the resin particle dispersion 1O was 9O in the preparation of the resin fine particle 1OP. 9 OP of resin fine particle dispersion was prepared.

(W) Preparation of resin fine particle dispersion 9OPQ (styrene-acrylic copolymer resin fine particle dispersion I)
In the preparation of the resin fine particle 1OPQ, the resin fine particle 9OPQ was dispersed in the same manner except that styrene was changed to 300.0 parts by mass, n-butyl acrylate was changed to 90.0 parts by mass, and the resin particle dispersion liquid 1OP was changed to 9OP. A styrene-acrylic copolymer resin fine particle dispersion I was prepared.

(X) Preparation of Resin Fine Particle Dispersion Liquid 10OP The resin fine particle dispersion liquid 10OP was prepared in the same manner except that pentaerythritol tetrabehenate was set to 0 parts by mass in the preparation of the resin fine particle 9OP.

(Y) Preparation of resin fine particle dispersion 10OPQ (styrene-acrylic copolymer resin fine particle dispersion J)
A styrene-acrylic copolymer resin fine particle dispersion J in which the resin fine particle 10OPQ was dispersed was prepared in the same manner except that the resin particle dispersion 9OP was changed to 10OP in the preparation of the resin fine particle 9OPQ.

(2) Preparation of crystalline polyester resin fine particle dispersion (aa) Preparation of crystalline polyester resin fine particle dispersion M A polyvalent carboxylic acid component is placed in a reaction vessel equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a rectification tower. 173.1 parts by mass of dodecanedioic acid, 55.0 parts by mass of 1,6-hexanediol and 58.0 parts by mass of 1,12-dodecanediol were charged as polyhydric alcohol components, and the temperature of the reaction system was raised over 1 hour. After raising the temperature to 190 ° C. and confirming that the inside of the reaction system was uniformly stirred, Ti (OBu) ₄ was added as a catalyst in an amount of 0.006% by mass based on the total amount of the polyvalent carboxylic acid component. Further, the temperature of the reaction system was raised from the same temperature to 240 ° C. over 6 hours while distilling off the generated water, and the dehydration condensation reaction was continuously carried out for 6 hours while maintaining the temperature at 240 ° C. for polymerization. The reaction was carried out to obtain a crystalline polyester resin m.

After adding methyl ethyl ketone and isopropyl alcohol to a reaction vessel equipped with an anchor blade that gives stirring power, the above crystalline polyester resin m roughly pulverized with a hammer mill is gradually added and stirred to completely dissolve. A crystalline polyester resin solution to be an oil phase was obtained. Next, a quantity of a dilute aqueous ammonia solution was added dropwise to this oil phase while stirring, and ion-exchanged water was further added dropwise to this oil phase for phase inversion emulsification, and then the solvent was removed while reducing the pressure with an evaporator to remove the crystalline polyester. Crystalline polyester resin fine particle dispersion M was obtained by generating resin fine particles and further adding ion-exchanged water to adjust the solid content to 20% by mass.

The volume-based median diameter of the resin fine particles in the obtained crystalline polyester resin fine particle dispersion M was measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.) and found to be 185 nm. It was.

(Ab) Preparation of Crystalline Polyester Resin Fine Particle Dispersion Solution N In the preparation of the above-mentioned crystalline polyester resin fine particle dispersion liquid M, 173.1 parts by mass of dodecanedioic acid, 55.0 parts by mass of 1,6-hexanediol, 1,12 Crystalline by using 158.1 parts by mass of dodecanedioic acid, 15.4 parts by mass of 1,6-hexanediol, and 112.5 parts by mass of 1,12-dodecanediol instead of 58.0 parts by mass of −dodecanediol. A polyester resin fine particle dispersion N was prepared.

(Ac) Preparation of crystalline polyester resin fine particle dispersion O In the preparation of (aa) crystalline polyester resin fine particle dispersion M, 173.1 parts by mass of dodecanedioic acid, 55.0 parts by mass of 1,6-hexanediol, A crystalline polyester resin fine particle dispersion O was prepared by using 189.0 parts by mass of dodecanedioic acid and 97.0 parts by mass of 1,6-hexanediol instead of 58.0 parts by mass of 1,12-dodecanediol. ..

(Ad) Preparation of Crystalline Polyester Resin Fine Particle Dispersion P In the preparation of the crystalline polyester resin fine particle dispersion M, 173.1 parts by mass of dodecanedioic acid, 55.0 parts by mass of 1,6-hexanediol, 1,12 A crystalline polyester resin fine particle dispersion P was prepared by using 168.6 parts by mass of dodecanedioic acid and 117.4 parts by mass of 1,9-nonanediol instead of 58.0 parts by mass of −dodecanediol.

(Ae) Preparation of crystalline polyester resin fine particle dispersion Q In the preparation of the crystalline polyester resin fine particle dispersion M, 173.1 parts by mass of dodecanedioic acid, 55.0 parts by mass of 1,6-hexanediol, 1,12 -Dodecandiol 66.1 parts by mass, glutaric acid 85.3 parts by mass, 1,6-hexanediol 75.9 parts by mass, 1,12-dodecanediol 58.7 parts by mass instead of 58.0 parts by mass A crystalline polyester resin fine particle dispersion Q was prepared by using the portion.

(3) Preparation of Carbon Black Dispersion Solution A solution prepared by stirring and dissolving 90 parts by mass of sodium dodecyl sulfate in 1600 parts by mass of ion-exchanged water is stirred, and 420 parts by mass of carbon black "Mogal L" is added to the solution. Part, gradually added. Next, a dispersion treatment was performed using a stirrer "Clearmix (manufactured by M Technique Co., Ltd.)" to prepare a "carbon black dispersion". When the particle size of carbon black in the "carbon black dispersion" was measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle size was 110 nm.

(4) Preparation of toner matrix particles <Preparation of toner matrix particles [i]>
In a reaction vessel equipped with a stirrer, temperature sensor, cooling tube, nitrogen introduction device,
-Crystalline polyester resin fine particle dispersion M 50.0 parts by mass (solid content equivalent)
-Styrene-acrylic copolymer resin fine particle dispersion liquid [A]
405.0 parts by mass (solid content conversion)
・ Ion-exchanged water 1100 parts by mass ・ Carbon black dispersion 50 parts by mass (solid content conversion)
After adjusting the liquid temperature to 30 ° C., a 5 mol / L sodium hydroxide aqueous solution was added to adjust the pH to 10.0.

While stirring this reaction system, an aqueous solution prepared by dissolving 60 parts by mass of magnesium chloride hexahydrate in 60 parts by mass of ion-exchanged water was added over 10 minutes, then left for 3 minutes, and then the temperature was raised. Initiating, the temperature of this system was raised to 90 ° C., and the resin fine particles were associated with each other while maintaining 90 ° C. to grow the particles.

While measuring the particle size of the associated particles using "Multisizer 3 (manufactured by Beckman Coulter)", ion exchange of 40.2 parts by mass of sodium chloride when the volume-based median diameter reaches 5.5 μm. An aqueous solution dissolved in 1000 parts by mass of water was added to the reaction system to stop the growth of particles to prepare core particles 1.

Next, 95.0 parts by mass (solid content equivalent) of the above-mentioned styrene-acrylic copolymer resin fine particle dispersion B was added, and 60 parts by mass of magnesium chloride hexahydrate was ionized while stirring this reaction system. An aqueous solution prepared by dissolving in 60 parts by mass of exchanged water was added over 10 minutes to obtain particles 2 in which styrene-acrylic copolymer resin fine particles B were fused to the surface of the particles 1. While measuring the particle size of the associated particles using "Multisizer 3 (manufactured by Beckman Coulter)", ion exchange of 180.0 parts by mass of sodium chloride when the volume-based median diameter reaches 6.0 μm. Particle 2 was prepared by adding an aqueous solution dissolved in 1000 parts by mass of water to the reaction system to stop the growth of the particles.

This system is heated and stirred at 95 ° C. for 20 minutes for aging treatment, fused, cooled to 30 ° C., filtered for solid content, and repeatedly washed with ion-exchanged water at 35 ° C. , 40 ° C., dried with warm air to prepare toner matrix particles [i].

<Preparation of toner matrix particles [ii]>
In the preparation of the toner matrix particles [i], the toner matrix particles [ii] are similarly prepared except that the styrene-acrylic copolymer resin fine particle dispersions A and B are made into styrene-acrylic copolymer resin fine particles C and D, respectively. Was produced.

<Preparation of toner matrix particles [iii]>
In the preparation of the toner matrix particles [i], the toner matrix particles [iii] are similarly prepared except that the styrene-acrylic copolymer resin fine particle dispersions A and B are made into styrene-acrylic copolymer resin fine particles E and F, respectively. Was produced.

<Preparation of toner matrix particles [iv]>
In the preparation of the toner matrix particles [i], the toner matrix particles [iv] were produced in the same manner except that the crystalline polyester resin fine particle dispersion M was changed to the crystalline polyester resin fine particle dispersion N.

<Preparation of toner matrix particles [v]>
In the preparation of the toner base particles [i], the toner base particles [v] were prepared in the same manner except that the crystalline polyester resin fine particle dispersion M was changed to the crystalline polyester resin fine particle dispersion O.

<Preparation of toner matrix particles [vi]>
In the preparation of the toner base particles [i], the toner base particles [vi] were prepared in the same manner except that 50 parts by mass of the crystalline polyester resin fine particle dispersion liquid M was changed to 12.3 parts by mass of the crystalline polyester resin fine particle dispersion liquid M12.3 parts by mass. ..

<Preparation of toner matrix particles [vii]>
In the preparation of the toner base particles [i], 50 parts by mass of the crystalline polyester resin fine particle dispersion M was placed in 100 parts by mass of the crystalline polyester resin fine particle dispersion P, and styrene-acrylic copolymer resin fine particle dispersions A and B were respectively styrene-. Toner matrix particles [vii] were produced in the same manner except that the acrylic copolymer resin fine particles C and D were used.

<Preparation of toner matrix particles [viii]>
In the preparation of the toner matrix particles [i], the toner matrix particles [viii] are similarly prepared except that the styrene-acrylic copolymer resin fine particle dispersions A and B are made into styrene-acrylic copolymer resin fine particles G and H, respectively. Was produced.

<Preparation of toner matrix particles [ix]>
In the preparation of the toner matrix particles [i], the toner matrix particles [ix] are similarly prepared except that the styrene-acrylic copolymer resin fine particle dispersions A and B are made of styrene-acrylic copolymer resin fine particles I and J, respectively. Was produced.

<Preparation of toner matrix particles [x]>
In the preparation of the toner matrix particles [i], the toner matrix particles [x] were produced in the same manner except that the crystalline polyester resin fine particle dispersion M was changed to the crystalline polyester resin fine particle dispersion Q.

<Preparation of toner matrix particles [xi]>
In the preparation of the toner base particles [i], the toner base particles [xi] were prepared in the same manner except that the crystalline polyester resin fine particle dispersion M was set to 0 parts by mass.

(5) Addition of external additive To 100 parts by mass of the obtained toner base particles [i], 1.5 parts by mass of hydrophobic silica (number average primary particle diameter = 50 nm) and hydrophobic titanium oxide (number average primary particle diameter) (= 20 nm) 0.5 parts by mass was added, mixed with a "Henshell mixer" (manufactured by Mitsui Miike Kakoki Co., Ltd.) at a peripheral speed of 35 mm / sec at 32 ° C. for 20 minutes, and then a sieve with a 45 μm opening was used. The toner 1 was produced by subjecting it to an external additive treatment for removing coarse particles. The obtained toner 1 had an average particle size (volume-based median diameter) of 6.0 μm. The average particle size was measured by the same method as described in the above section.

<Preparation of toners 2 to 11>
In the production of the toner 1, the toners 2 to 11 were produced in the same manner except that the toner matrix particles [i] were changed to the toner matrix particles [ii] to [xi].

<Creation of carrier>
100.0 parts by mass of "ferrite particles" and 2.0 parts by mass of "coating resin (CHMA: MMA = 50: 50)" were put into a high-speed stirring mixer with stirring blades, and the peripheral speed of the horizontal rotor was 8 m / A carrier was prepared by mixing and stirring at 22 ° C. for 30 minutes under the condition of sec, and then mixing at 120 ° C. for 50 minutes.

<Preparation of two-component developer 1>
100.0 parts by mass of the "carrier" prepared above and 6.0 parts by mass of "toner 1" were mixed in a V-type mixer for 5 minutes to prepare "two-component developer 1".

<Preparation of two-component developer 2-11>
In the preparation of the two-component developer 1, "two-component developer 2-11" was produced in the same manner except that "toner 1" was changed to "toner 2-11".

≪Evaluation method≫
(1) Measurement of tangent loss (tan δ) of dynamic viscoelasticity in temperature modulation (preparation of sample for measurement of tangent loss (tan δ) of dynamic viscoelasticity)
Using a pressure molding machine (NT-100H, manufactured by NPA System Co., Ltd.), the toner is pressurized to 3000 kgf at room temperature for 30 seconds to form a cylindrical sample having a diameter of about 8 mm and a height of about 2 mm.

(Measurement procedure of tangent loss (tan δ) of dynamic viscoelasticity)
Using a viscoelasticity measuring device (ARES-G2 rheometer manufactured by TA Instruments), the columnar sample prepared above is placed on a parallel plate heated to a temperature equal to or higher than the softening point of the toner, and heated and melted. After that, a load is applied in the vertical direction so that the axial force does not exceed 10 (g weight), and the sample is fixed to the parallel plate. In this state, the temperature of the parallel plate and the columnar sample is lowered to the measurement start temperature of 30 ° C., and the viscoelasticity data is measured. The measured data is transferred to a computer equipped with Microsoft Windows 7 (“Windows” is a registered trademark of the company), and the data is transferred through the control, data collection and analysis software (TRIOS) operating on the computer, and 45 The value of tan δ at ℃, 50 ℃, 55 ℃, and 60 ℃ was read, and the temperature indicating the maximum value of tan δ was read.
For Examples 1 to 6 and Comparative Examples 1 to 5, a graph was created in which the tangent loss (tan δ) of dynamic viscoelasticity with respect to temperature modulation of the electrostatic charge image developing toner was plotted (FIG. 1).
Further, from the obtained values of tan δ at each temperature, [tan δ (60 ° C.) / tan δ (55 ° C.)], [tan δ (55 ° C.) / tan δ (45 ° C.)], and [(tan δ (60 ° C.) / The value of tan δ (50 ° C.)] was obtained.
In Table I, the cases where the formulas (1) to (3) according to the present invention are satisfied are marked with ◯, and the cases where the formulas (3) are not satisfied are marked with x. Further, the case where the maximum value of tan δ was between 60 and 70 ° C. was evaluated as ◯, and the case where the maximum value was not provided was evaluated as ×.

(Measurement conditions for tangent loss (tan δ) of dynamic viscoelasticity)
Parallel plate: Aluminum plate with a diameter of 8 mm
Measurement frequency: 6.28 radians / second
Measurement distortion setting: Set the initial value to 0.1% and perform measurement in the automatic measurement mode.
Sample elongation correction: Adjust in automatic measurement mode.
Measurement temperature: Heat from 30 ° C to 200 ° C at 3.0 ° C per minute.
Measurement interval: Viscoelastic data is measured every 1 ° C.

(2) Low-temperature fixability A modified machine of the copying machine "bizhub PRO (registered trademark) C6500" (manufactured by Konica Minolta Co., Ltd.) is prepared, loaded with the two-component developer set prepared above, and a heating roller of an image evaluation device. The surface temperature (measured at the center of the roller) is changed in 5 ° C increments in the range of 90 to 130 ° C, and at each surface temperature, a solid black band image with a width of 5 mm in the direction perpendicular to the transport direction is displayed. An A4 image having a halftone image having a width of 20 mm was conveyed in a lateral feed manner, and a determination was made in a temperature region (non-offset region) in which image stains due to the fixing offset did not occur.

[Evaluation criteria]
⊚: The lower limit temperature of the non-offset region is 110 ° C. or lower, and the temperature region is 15 ° C. or higher (very good fixability).
◯: The lower limit temperature of the non-offset region is 120 ° C. or less, and the temperature region is less than 15 ° C. (good fixability).
X: The lower limit temperature of the non-offset region is 125 ° C or higher (cannot be used due to poor fixability)
(3) Heat-resistant storage (aggregation rate)
Take 0.5 g of toner in a 10 ml glass bottle with an inner diameter of 21 mm, close the lid, shake with a tap denser KYT-2000 (manufactured by Seishin Enterprise) 600 times at room temperature, and then with the lid removed, 55 ° C, 35% RH. It was left in the environment of 2 hours. Next, place the toner on a sieve of 48 mesh (opening 350 μm), being careful not to crush the toner aggregates, set it on a powder tester (manufactured by Hosokawa Micron), and fix it with a holding bar and knob nut. After adjusting the vibration intensity to a feed width of 1 mm and applying vibration for 10 seconds, the ratio (mass%) of the amount of toner remaining on the sieve was measured.

The toner aggregation rate is a value calculated by the following formula.

(Toner aggregation rate (%)) = (Mass of residual toner on sieve (g)) /0.5 (g) x 100
The heat-resistant storage property of the toner was evaluated according to the criteria described below.

[Evaluation criteria]
⊚: Toner aggregation rate is less than 15% by mass (toner heat resistance is extremely good)
◯: Toner aggregation rate is 20% by mass or less (good heat-resistant storage of toner)
X: Toner aggregation rate exceeds 20% by mass (toner cannot be used due to poor heat storage performance)
(4) Adhesion resistance Using "BizHab PRO C6000L" (manufactured by Konica Minolta) modified so that the fixing temperature can be changed, a solid image with a toner adhesion amount of 10 g / m ² is fixed at a fixing temperature of 150 ° C. Three sheets fixed at a linear speed of 400 mm / sec were output. The two fixed images obtained are overlapped so that the image portion and the non-image portion and the image portion overlap each other, and the remaining one fixed image and the polypropylene sheet are overlapped so that the image portion overlaps the polypropylene sheet. The images were stacked facing each other, and weights were placed on the stacked portions so as to be equivalent to 80 g / cm ^2, and left in a constant temperature and humidity chamber at a temperature of 55 ° C. and a humidity of 50% for 3 days. After being left to stand, the two sets of fixed images that were overlapped were peeled off, and the degree of image defect was classified into levels according to the following evaluation criteria, thereby evaluating the document offset resistance (sticking resistance).

[Evaluation criteria]
⊚: Level where there is no problem with no transition to one side ○: There is no transition to one side of the image and there is uneven gloss △: There is some transition to one side of the image, but allowable level ×: Difficult to separate the image, the image The above evaluation results are shown in Table I below.

From Table I, Examples 1 to 6 of the toner for static charge image development, which satisfy the above formulas (1) to (3) according to the present invention and have a maximum value in the range of 60 to 70 ° C., have low temperature fixability. It can be seen that the toner is an electrostatic charge image developing toner having excellent heat-resistant storage properties and sticking resistance.

On the other hand, Comparative Example 1 has good low-temperature fixability but is inferior in heat-resistant storage and sticking resistance because it is a toner having a maximum value in the temperature range of less than 60 in the formulas (1) and (3). ..

Comparative Example 2 is inferior in low temperature fixability because it does not satisfy the formula (2).

Since Comparative Example 3 does not satisfy the formulas (1) and (2), it has good low-temperature fixability, but is inferior in heat-resistant storage property and sticking resistance.

Since Comparative Example 4 is a toner having a maximum value in a temperature range of less than 60 ° C., it has good low-temperature fixability, but is inferior in heat-resistant storage property and sticking resistance.

On the other hand, Comparative Example 5 is inferior in low-temperature fixability because it is a toner having a maximum value in a temperature range exceeding 70 ° C.

From the above, a toner for static charge image development that satisfies the above formulas (1) to (3) and has a maximum value in the range of 60 to 70 ° C. is used to achieve low temperature fixability, heat storage property, and sticking resistance. It has been found that it can provide excellent toner.

1Y, 1M, 1C, 1K electrophotographic photosensitive member 2Y, 2M, 2C, 2K Charging means 3Y, 3M, 3C, 3K Exposure means 4Y, 4M, 4C, 4K Developing means 5Y, 5M, 5C, 5K Primary transfer roller (primary) Transfer means)
5b Secondary transfer unit (secondary transfer means)
6Y, 6M, 6C, 6K, 6b Cleaning means 10Y, 10M, 10C, 10K Image forming unit 20 Paper cassette 21 Paper feed means 22A, 22B, 22C, 22D Intermediate roller 23 Resist roller 24 Fixing means 25 Paper discharge roller 26 Discharge Paper tray 70 Intermediate transfer unit 71-74 Roller 77 Endless belt-shaped intermediate transfer 80 Housing 82R, 82L Support rail 300 Image forming device

Claims (3)

At least, it is a toner for developing an electrostatic charge image containing toner matrix particles containing a release agent and a binder resin.
The binding resin contains at least a crystalline polyester resin and
In the viscoelasticity measurement by temperature modulation of the electrostatic charge image developing toner, the tangent loss (tanδ) of the dynamic viscoelasticity at temperatures of 45 ° C., 50 ° C., 55 ° C., and 60 ° C. was tanδ (45 ° C.), respectively. , Tanδ (50 ° C.), tanδ (55 ° C.), and tanδ (60 ° C.).
The value of the ratio of tan δ (55 ° C) to tan δ (45 ° C) is [tan δ (55 ° C) / tan δ (45 ° C)], and the value of the ratio of tan δ (60 ° C) to tan δ (50 ° C) is [tan δ (60 ° C)]. ° C.) / Tanδ (50 ° C.)] and the ratio of tanδ (60 ° C.) to tanδ (55 ° C.) is defined as [tanδ (60 ° C.) / tanδ (55 ° C.)], and the following equations (1) to Satisfy (3) and
A toner for static charge image development, characterized in that the curve of tan δ with respect to temperature has one maximum value in the temperature range of 60 to 70 ° C.
Equation (1) [tan δ (60 ° C.) / tan δ (55 ° C.)] <[tan δ (55 ° C.) / tan δ (45 ° C.)],
Equation (2) 1.0 ≤ [tan δ (55 ° C) / tan δ (45 ° C)] ≤ 5.0,
Equation (3) [(tan δ (60 ° C) / tan δ (50 ° C)] ≤ 2.5 The toner for developing an electrostatic charge image according to claim 1, wherein the [tan δ (60 ° C./tan δ (55 ° C.)] is in the range of 1.0 to 3.0. The value (A / B) of the mass ratio of the content (B) of the release agent to the content (A) of the crystalline polyester is in the range of 40/60 to 60/40. The toner for developing an electrostatic charge image according to claim 1 or 2.

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