JP2000010344A - Black composite nonmagnetic particle powder for black toner and black toner using this black composite nonmagnetic particle powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide black nonmagnetic particle powder excellent in fluidity and having a high volumetric specific resistance value capable of restraining reduction in a charged amount of a black toner even when the powder is included the black toner in large quantities. SOLUTION: Black composite nonmagnetic particle powder for a black toner is composed of black composite nonmagnetic particle powder having the average particle size of 0.08 to 1.0 μm where one kind or two or more kinds of particulate powders selected from oxide particulate powder or hydroxide containing particulate powder of respective elements of Si, Zr, Ti, Al and Ce exist between the particle surface of black hematite particle powder or black iron hydroxide containing particle powder and methyl hydrogen polysiloxane covering the particle surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a high volume resistivity which is excellent in fluidity and can suppress a decrease in the charge amount of a black toner even when a large amount is contained in the black toner. It is an object of the present invention to provide a black nonmagnetic particle powder for a black toner having a certain value and a black toner using the black nonmagnetic particle powder.

[0002]

2. Description of the Related Art In an electrophotographic development process, a black toner in which a nonmagnetic black pigment such as carbon black is mixed and dispersed in a binder resin is widely used as a developer.

[0003] Recent development methods can be broadly classified into two-component development methods and one-component development methods.

In the two-component developing method, a black toner and a carrier are rubbed to give a charge of the opposite sign to the electrostatic latent image to the black toner, and the black toner is adhered to the surface of the electrostatic latent image by electrostatic attraction. And developing by neutralizing the charge.

On the other hand, the one-component developing method does not require a carrier, so that it is not necessary to control the density of the black toner.
Although the developing device has a simple structure and can be miniaturized, a high level of technology is required to obtain the same performance as the two-component developing method. As one of the one-component developing methods, a so-called insulating non-magnetic toner using an insulating or high-resistance black toner in which carbon black fine particles are dispersed in a binder resin without using magnetic particles. There is a development method.

[0006] The black toner used in the two-component developing method and the insulating non-magnetic toner developing method is insulative or highly resistant in the case of the PPC system, which is currently the mainstream in copiers. And it is required that the volume specific resistance value be 10 ¹² Ω · cm or more.

[0007] The fluidity of the developer strongly controls the behavior of the developer in the developing machine, and the frictional charging property between the black toner and the carrier in the two-component developing method or on the sleeve in the one-component developing method. Is known to affect the charging characteristics of the black toner, and with the recent increase in image quality and speed of the developing machine, such as image density and gradation, the fluidity of the black toner has been strongly improved. Has been requested.

[0008] Improvements in the fluidity of the black toner have been increasingly required in recent years as the particle size of the black toner has been reduced.

This fact is described in “Recent Electrophotographic Development System and Development and Commercialization of Technical Materials for Toner Materials” (1985), page 121, “‥
湿 A small diameter wet toner can provide high resolution. In order to increase the resolving power by using a dry toner, it is necessary to reduce the diameter of the toner. (4) By using a toner having a size of 8.5 μ to 11 μ, it is possible to improve the background fog and further reduce the consumption. In addition, when a 6 to 10 micron polyester-based toner is used, there are proposals for improving image quality, stabilizing chargeability, and improving developer life. However, many problems must be solved when using small diameter toner. There are manufacturability, sharpness of particle size distribution, improvement of fluidity, and the like. ‥‥ ”.

Next, a black toner having an insulating property or a high resistance is
It is required that the copied line image and solid area image have high blackness and high density.

[0011] This fact is described in the above-mentioned "Recent Electrophotographic Development System and Development and Practical Application of Toner Materials.
(1985), p. 272, "High image density is a characteristic of powder development, but it is a matter that greatly affects image characteristics together with fog density described later." .

Further, the insulating or high-resistance black toner is
Since it is necessary to maintain the charge required for development, it is strongly required to have a volume resistivity of 10 ¹² Ω · cm or more as described above.

This fact is described in the above-mentioned “Recent Electrophotographic Development System and Comprehensive Technical Data Collection for Development and Practical Use of Toner Materials”.
(1985), p. 266, "When the charge amount is low, the attraction between the toner and the carrier is weak, so that the toner is detached by the stirring of the developing unit, the mechanical impact force with the photoreceptor, and the like. Conversely, if the charge amount is too high, it remains on the carrier, the amount of toner transferred to the photoreceptor decreases, and the image density decreases.The relationship between the charge amount of Thompson and image quality is shown in FIG. ^In general, a volume resistivity value of ¹² Ω · cm or more is required (in the case of an insulating toner).

As described above, there is a strong demand for improvement of various characteristics of the black toner. It is known that the various properties of the black toner are affected by, in particular, the black pigment contained in the toner and the black pigment exposed from the surface of the toner. There is a close relationship with the properties of the black pigment used.

That is, since the fluidity of the black toner largely depends on the surface state of the black pigment exposed on the surface of the black toner, it is strongly required that the black pigment itself has excellent fluidity. Similarly, the degree of blackness and darkness of the black toner also largely depends on the content of the black pigment contained in the black toner. As the content of the black pigment increases, the blackness of the black toner increases. As described above, the insulating or high-resistance black toner needs to have an insulating property enough to maintain the charge, in particular, a volume specific resistance value of 10 ¹² Ω · cm or more. There is a strong demand that the decrease in the charge amount of the black toner can be suppressed even when the content of the black pigment is increased in order to increase the toner content.

That is, in order to maintain the volume resistivity of the black toner as high as possible, it is strongly required that the volume resistivity of the black pigment be as high as possible.

At present, carbon black fine powder is mainly used as a black pigment used in a black toner (JP-A-4-142561, JP-A-10-39).
546).

[0018]

In addition to having excellent fluidity, the black toner has a high volume resistivity which can suppress a decrease in the charge amount of the black toner even when the content of the black pigment is increased. At present, black pigments for black toner are most demanded, but black pigments having such properties have not yet been obtained.

That is, when the above-mentioned known carbon black fine particle powder is used as a black pigment for a black toner, in order to obtain a black toner having a volume resistivity of 10 ¹² Ω · cm or more, the carbon black fine particle powder must be conductive. Since the amount of the black toner used is limited due to exhibiting the property, there is a problem that the obtained black toner cannot obtain a sufficient degree of blackness. In addition, there is a problem that the fluidity is not sufficient.

Then, the carbon black fine particle powder is
Safety and health issues have also been pointed out. These facts are described below.

Since the carbon black fine particles are conductive themselves and have a volume resistivity of 10 Ω · cm or less, the volume resistivity of the black toner decreases when used in a large amount to increase the blackness. Therefore, it cannot be used as an insulating or high-resistance toner. On the other hand, in order to obtain an insulating or high-resistance black toner, when the amount of the carbon black fine particle powder used is reduced, the average particle size of the carbon black fine particle powder is as fine as 0.010 to 0.060 μm. For this reason, the fine particles of carbon black are contained and buried in the particles of the black toner, and the fine particles of carbon black are not exposed on the surface of the particles of the black toner, resulting in poor fluidity.

Further, the carbon black fine particle powder has a very low specific gravity of 1.80 to 1.85, so that it is difficult to handle the carbon black fine particle powder. The resulting black toner is easily scattered because only low black toner is obtained.
In addition, the fluidity is poor.

It has also been reported that among the substances generated during the production process of carbon black fine particle powder, substances suspected of carcinogenicity are included as impurities in the carbon black fine particle powder. The safety of black toner has been pointed out.

Accordingly, the present invention provides a high volume specific resistance value which is excellent in fluidity and capable of suppressing a decrease in the charge amount of the black toner even when contained in a large amount in the black toner. It is a technical object to obtain black nonmagnetic particle powder having the same.

[0025]

The above technical object can be achieved by the present invention as described below.

That is, according to the present invention, Si, Zr, Ti, Al and Ce are interposed between the particle surface of black hematite particles or black hydrated iron oxide particles and the methylhydrogenpolysiloxane coating the particle surfaces. A black composite non-magnetic particle powder having an average particle diameter of 0.08 to 1.0 μm in which one or two or more types of fine particle powders selected from oxide fine particle powders or hydrated oxide fine particle powders of the respective elements are present; Black composite non-magnetic particles for black toner.

The present invention also relates to black hematite particles coated with one or more compounds selected from aluminum hydroxide, aluminum oxide, silicon hydroxide and silicon oxide. Powder or black iron oxide hydroxide particles, wherein Si, Zr, Ti, Al and C are present between the compound-coated surface and the methylhydrogenpolysiloxane further coating the compound-coated surface.
black composite non-magnetic particle powder having an average particle diameter of 0.08 to 1.0 μm in which one or two or more kinds of fine particle powder selected from oxide fine particle powder or hydrated oxide fine particle powder of each element of e are present And a black composite non-magnetic particle powder for a black toner.

Further, the present invention is a black toner using any of the black composite non-magnetic particles described above.

The structure of the present invention will be described in more detail as follows.

First, the black composite nonmagnetic particle powder according to the present invention will be described.

The core particle powder in the present invention is black hematite particle powder or black hydrated iron oxide particle powder. As the black hematite particle powder, there is a manganese-containing hematite particle powder containing 5 to 40% by weight of manganese with respect to the black hematite particle powder. As the black iron oxide hydroxide particles, 5 to 40 black iron oxide hydroxide particles are used.
There are manganese-containing iron hydroxide particles containing manganese by weight. Considering the degree of blackness of the obtained black nonmagnetic particle powder, manganese-containing hematite particle powder is preferable as the core particle powder.

The particle shape of the core particle powder is spherical, octahedral, hexahedral, granular or the like and has a sphericity (ratio of average longest diameter to average shortest diameter) (hereinafter, referred to as “sphericity”) of less than 2. Axial ratio (ratio between average major axis diameter and average minor axis diameter) of isotropic particle powder, needle shape, spindle shape, rice grain shape, etc. (hereinafter referred to as “axial ratio”).
Can be used. In consideration of the fluidity of the obtained black composite non-magnetic particle powder, isotropic particle powder is preferable, and the sphericity is 1.0.
Manganese-containing hematite particles having a sphericity of ~ 1.5 are more preferred.

The upper limit of the axial ratio of the anisotropic particle powder is preferably 20, more preferably 18, and even more preferably 15. If it exceeds 20, the entanglement of the particles increases, and Si, Zr, Ti, Al
And a uniform adhesion treatment with one or more selected from oxide fine particle powder or hydrated oxide fine particle powder of each element of Ce and Ce (hereinafter referred to as "fine particle powder") and uniformity with methyl hydrogen polysiloxane. It becomes difficult to perform a proper coating process.

The particle size of the core particle powder has an average particle diameter (average major axis diameter in the case of anisotropic particles) of 0.055 to 0.5.
It is 95 μm, preferably 0.065 to 0.75 μm, and more preferably 0.065 to 0.45 μm.

If the average particle diameter of the core particle powder exceeds 0.95 μm, the resulting black composite non-magnetic particle powder becomes coarse particles and the coloring power is reduced. When the particle diameter is less than 0.055 μm, aggregation tends to occur due to an increase in intermolecular force due to the formation of fine particles of the particles. Therefore, uniform treatment of the fine particle powder on the surface of the core particle powder and uniformization by methyl hydrogen polysiloxane It becomes difficult to perform a proper coating process.

The geometric standard deviation value of the particle diameter (major axis diameter in the case of anisotropic particles) of the core particle powder is preferably 1.01 to 2.0, more preferably 1.01 to 1.8. And more preferably from 1.01 to 1.6. When the geometric standard deviation value exceeds 2.0, the dispersion is hindered by the existing coarse particles, and it becomes difficult to perform a uniform adhesion treatment of the fine particle powder and a uniform coating treatment with methyl hydrogen polysiloxane. Those having a geometric standard deviation of less than 1.01 are difficult to obtain industrially.

The BET specific surface area value of the core particle powder is 0.5
m ² / g or more. If it is less than 0.5 m ² / g, the core particle powder is coarse, or the particles are sintered between the particles and the particles, and the resulting black composite nonmagnetic particle powder is also coarse. The coloring power decreases. It is preferably at least 1.0 m ² / g, more preferably at least 3.0 m ² / g, and the upper limit is 90 m ² / g. Considering the uniform adhesion treatment of the fine particle powder to the particle surface of the core particle powder and the uniform coating treatment with methyl hydrogen polysiloxane, it is preferably 70 m ² / g or less, more preferably 50 m ² / g or less.

The fluidity of the core particle powder is 25.
About 43. Among the core particle powders of various shapes, the granular manganese-containing hematite particle powder has excellent fluidity, but is still about 30 to 43.

Regarding the blackness of the core particle powder, in the case of the manganese-containing hematite particle powder, the lower limit value of the L ^* value usually exceeds 18, and the upper limit value is 28, preferably 26. In the case of manganese-containing goethite particles, the lower limit of the L ^* value is usually 1
It exceeds 8, and the upper limit is 30, preferably 28. L ^*
When the value is more than 30.0, the lightness becomes high and black composite non-magnetic particles having sufficient blackness cannot be obtained.

The volume resistivity of the core particle powder is generally about 5.0 × 10 ^{6 to} 8.0 × 10 ⁷ Ω · cm.

In the present invention, the fine particle powder present between the particle surface of the core particle powder and the methylhydrogenpolysiloxane coating does not reduce the blackness of the core particle powder, Fine particle powder that is uniformly attached and present, that is, non-magnetic, paramagnetic fine particle powder that exhibits transparency and does not magnetically aggregate is preferable.
One or two selected from oxide fine particle powder or hydrated oxide fine particle powder of each element of i, Zr, Ti, Al and Ce
More than one species can be used.

The particle size of the fine particle powder is 0.001 to 0.1 μm, more preferably 0.002 to 0.1 μm.
0.08 μm.

When the particle size is less than 0.001 μm, since the fine particle powder is too fine, no irregularities can be formed on the particle surface of the obtained black composite nonmagnetic particle powder, and it is difficult to improve the fluidity. Becomes In addition, since dispersion becomes difficult due to an increase in intermolecular force due to fine particles, the fine particle powder is uniformly adhered to the particle surface of the core particle powder.
It becomes difficult to obtain a black composite non-magnetic particle powder that is present.

When the average particle size exceeds 0.1 μm, the particle size of the fine particle powder becomes too large with respect to the particle size of the core particle powder, so that the adhesion of the core particle powder to the particle surface tends to be insufficient.

The ratio of the average particle diameter of the core particle powder to the average particle diameter of the fine particle powder is preferably 2 or more. If it is smaller than 2, the particle size of the fine particle powder becomes too large with respect to the particle size of the core particle powder, so that the adhesion of the core particle powder to the particle surface tends to be insufficient.

The abundance of the fine particle powder is calculated as SiO ₂ , ZrO ₂ , TiO ₂ , Al ₂
0.1 to 50 wt% preferably at O ₃ terms or terms of CeO _2, and more preferably from 0.5 to 45 wt%.

When the amount is less than 0.1% by weight, the black composite nonmagnetic particle powder obtained does not have sufficient fluidity because the amount of the attached fine particle powder is insufficient.

When it exceeds 50% by weight, the obtained black composite nonmagnetic particle powder has sufficient fluidity,
The fine particle powder is likely to be detached, and as a result, the volume specific resistance value may be reduced, and the dispersibility in the binder resin during the production of the black toner may be reduced.

It is known that the fine particle powder has various degrees of negative charging property or positive charging property depending on the kind thereof, and the kind of the fine particle powder to be present on the surface of the core particle powder can be obtained. An appropriate selection may be made in consideration of the charging characteristics of the black toner.

The methylhydrogenpolysiloxane of the present invention is represented by the following formula (1) and contains a Si—H reactive group in the molecule. Since this methylhydrogenpolysiloxane has transparency, the blackness of the core particle powder is not impaired, and the resulting black composite non-magnetic particle powder is substantially equivalent to the blackness of the core particle powder. Blackness of

## STR1 ## (CH ₃ HSiO) _n ((CH ₃ ) ₃ SiO _1/2 ) ₂
(However, n is 10 to 830)

In consideration of uniform coating treatment with methyl hydrogen polysiloxane, n is preferably from 14 to 450, and more preferably from 20 to 325. Specifically, commercially available TSF484 (molecular weight of about 3,500), TS
F483 (molecular weight of about 9,200) (all trade names, manufactured by Toshiba Silicone Co., Ltd.) or the like may be used.

The coating amount of the methylhydrogenpolysiloxane was determined based on the amount of SiO ₂
It is preferably 0.1 to 50% by weight in terms of conversion. More preferably, 0.2 to 40% by weight, still more preferably, 0.1 to 40% by weight.
5 to 30% by weight.

When the amount is less than 0.1% by weight, the amount is insufficient to coat the particle surface of the core particle powder in which the fine particle powder is present on the particle surface. Is removed from the particle surface of the core particle powder, so that it is difficult to obtain a black toner having excellent fluidity. Also,
Since the fine particle powder that cannot be completely covered with methylhydrogenpolysiloxane is exposed on the particle surface of the core particle powder, the volume specific resistance value of the obtained black composite nonmagnetic particle powder decreases.

When the amount exceeds 50% by weight, the coating amount of the methylhydrogenpolysiloxane is too large, so that unevenness on the particle surface of the obtained black composite non-magnetic particle powder is not clear, and the fluidity is reduced. Further, since the effect of improving the volume resistivity is saturated, there is no point in covering more than necessary.

The particle shape and particle size of the black composite non-magnetic particle powder according to the present invention greatly depend on the particle shape and particle size of the core particle powder, and have a particle shape similar to the core particles. It has a particle size slightly larger than the particle powder.

That is, the black composite nonmagnetic particle powder according to the present invention has an average particle diameter (average major axis diameter in the case of anisotropic particle powder) of 0.06 to 1.0 μm, preferably 0.07 to 1.0 μm.
0.8 μm, more preferably 0.07 to 0.5 μm. In the case of isotropic particle powder, the sphericity is 1.0 or more and less than 2, preferably 1.0 to 1.5. In the case of the powdery particles, the upper limit of the axial ratio is 20, preferably 18, and more preferably 15.

When the average particle diameter of the black composite non-magnetic particle powder exceeds 1.0 μm, the black composite non-magnetic particle powder is coarse and the coloring power is reduced. When the particle size is less than 0.06 μm, aggregation tends to occur due to an increase in intermolecular force due to fine particles, so that the dispersibility in the binder resin during the production of the black toner decreases.

When the axial ratio exceeds 20, the entanglement of the particles increases, and the dispersibility in the binder resin during the production of the black toner may decrease.

The geometric standard deviation of the particle diameter of the black composite nonmagnetic particles is preferably 2.0 or less, and the lower limit thereof is 1.0.
It is about 1, more preferably in the range of 1.01 to 1.8, and still more preferably 1.01 to 1.6. When the geometric standard deviation value exceeds 2.0, the coloring power of the black composite non-magnetic particle powder is liable to decrease due to the existing coarse particles. Those having a geometric standard deviation of less than 1.01 are difficult to obtain industrially.

[0060] BET specific surface area value of the black composite non-magnetic particles is 0.5m ² / g~100m ² / g. 0.5m
If it is less than ² / g, the black composite nonmagnetic particle powder is coarse and the coloring power is reduced. If it exceeds 100 m ² / g, aggregation tends to occur due to an increase in the intermolecular force due to finer particles, so that the dispersibility in the binder resin during the production of the black toner decreases. In consideration of the coloring power of the black composite non-magnetic particle powder and the dispersibility in the binder resin during the production of the black toner, it is preferably 1.0 to 9
0 m ² / g, more preferably 3.0~80m ² / g.

The fluidity of the black composite non-magnetic particle powder is preferably such that the fluidity index is in the range of 47 to 70, more preferably 48 to 70, and still more preferably 49 to 70. The fluidity index of the black composite non-magnetic particle powder coated with aluminum hydroxide or the like is 49.
~ 80 is preferred, more preferably 50-80,
Still more preferably, it is 51 to 80. Liquidity index 4
If it is less than 7, it is difficult to say that the fluidity is sufficient, and a problem such as clogging of a hopper is liable to occur in the manufacturing process, and handling becomes difficult.

When the manganese-containing hematite particle powder is used as the core particle powder, the lower limit of the L ^* value usually exceeds 18, and the upper limit of the black composite nonmagnetic particle powder is 2 when the manganese-containing hematite particle powder is used.
When the manganese-containing goethite particle powder is used as the core particle powder, the lower limit of the L ^* value usually exceeds 18, and the upper limit is 30, and preferably 28. If the L ^* value exceeds 30.0, the lightness increases and the blackness is not sufficient.

The volume resistivity of the black composite non-magnetic particle powder is at least 3.0 × 10 ⁸ Ω · cm, and preferably about 5.0 × 10 ^{8 to} 5.0 × 10 ¹¹ Ω · cm. .
When the volume resistivity is less than 3.0 × 10 ⁸ Ω · cm, the volume resistivity of the obtained black toner is undesirably reduced.

The dispersibility of the black composite nonmagnetic particle powder is preferably 4 or 5, and more preferably 5, based on the method for evaluating dispersibility described below.

The core particle powder may have, if necessary, a surface of the particle in advance of one or more compounds selected from the group consisting of aluminum hydroxide, aluminum oxide, silicon hydroxide and silicon oxide. Hereinafter, the coating may be performed by “coating with aluminum hydroxide or the like”, which enables more uniform adhesion treatment of the fine particle powder as compared with the case where the coating is not performed with aluminum hydroxide or the like. The fluidity of the resulting black composite nonmagnetic particle powder is further improved.

The amount of the aluminum hydroxide or the like to be coated is calculated by converting the core particle powder coated with the aluminum hydroxide or the like into an Al equivalent, a SiO ₂ equivalent, or an Al equivalent amount and a SiO ₂ equivalent.
It is preferably 0.01 to 50% by weight in total with the reduced amount.

When the amount is less than 0.01% by weight, the effect of improving the fluidity of the obtained black composite non-magnetic particles cannot be obtained.

When the amount exceeds 50% by weight, the effect of improving the fluidity of the obtained black composite non-magnetic particles can be obtained.
There is no point in coating more than necessary.

The black composite non-magnetic particle powder according to the present invention coated with aluminum hydroxide or the like is the same as the black composite non-magnetic particle powder according to the present invention not coated with aluminum hydroxide or the like. It has improved fluidity with substantially the same particle size, geometric standard deviation value, BET specific surface area value, blackness L ^* value and volume resistivity value.

Next, the black toner according to the present invention will be described.

Generally, the black toner is used in an amount of 200 to 3500 with respect to at least the black pigment and 100 parts by weight of the black pigment.
The average particle size of 3 to 2 parts by weight of the binder resin
5 μm, preferably 4 to 18 μm, more preferably 5 to
15 μm composite particles (hereinafter referred to as “composite particles”).

The composite particles may optionally contain a release agent,
It may contain a colorant, a charge control agent, other additives, and the like.

The black toner according to the present invention contains the black composite non-magnetic particle powder according to the present invention inside the composite particles instead of the above-mentioned black pigment constituting the composite particles, May be used, or may be used by being attached to and present on the surface of the composite particles described above, and may be used inside the composite particles instead of the black pigment constituting the composite particles. While being contained, it is exposed on the surface of the composite particle, and further adheres to the surface of the composite particle.
It may be used in the presence.

When the black composite non-magnetic particle powder is contained inside the composite particle and used while being exposed on the surface of the composite particle, the ratio of the black composite non-magnetic particle powder to the binder resin is as follows. The binder resin is used in an amount of 200 to 3,500 parts by weight, preferably 300 to 2,000 parts by weight, based on 100 parts by weight of the nonmagnetic particles. If the amount is less than 200 parts by weight, the kneading property is reduced because the amount of the binder resin is small relative to the black composite nonmagnetic particle powder, and it becomes difficult to obtain good composite particles. If the amount exceeds 3500 parts by weight, the coloring power is reduced because the amount of the binder resin is too large relative to the black composite nonmagnetic particle powder, and the black composite nonmagnetic particle powder exposed on the composite particle surface is reduced. This is not preferred because the fluidity is reduced.

The black toner according to the present invention is contained in the composite particles, and the black composite non-magnetic particle powder used by being exposed on the surface of the composite particles is made of carbon as long as its properties are not impaired. It may be replaced with black fine particle powder. The amount ratio of the carbon black fine particle powder that can be replaced with the black composite non-magnetic particle powder is less than 50 parts by weight, preferably 45 parts by weight or less, more preferably 40 parts by weight, out of 100 parts by weight of the black composite non-magnetic particle powder. The following is the range, and the intended black toner can be obtained within this range.

When the black composite non-magnetic particle powder is used by adhering and existing on the surface of the composite particle, the ratio of the black composite non-magnetic particle powder is 0 to 100 parts by weight of the composite particle. 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight. If the amount is less than 0.1 part by weight, the effect of improving the fluidity of the black toner cannot be obtained. If the amount exceeds 10 parts by weight, the effect of improving fluidity is saturated, so that there is no point in adding more than necessary.

The black composite non-magnetic particle powder is contained inside the composite particles, and is exposed on the surface of the composite particles.
Further, when used by adhering to and present on the surface of the composite particles, the ratio of the black composite non-magnetic particle powder and the binder resin constituting the composite particles is determined by the ratio of the black composite non-magnetic particle powder 10
0 to 3 parts by weight of binder resin with respect to 0 parts by weight,
Preferably, the amount is from 300 to 2,000 parts by weight, and the ratio of the black composite nonmagnetic particle powder adhering to and present on the composite particle surface is 0.1 to 10 parts by weight of the black composite nonmagnetic particle powder with respect to 100 parts by weight of the composite particle. Parts, preferably 0.5 to 5 parts by weight. Also, while being contained inside the composite particles, the black composite nonmagnetic particle powder used by being exposed to the surface of the composite particles is less than 50 parts by weight, preferably 45 parts by weight or less, more preferably 40 parts by weight or less. Parts by weight or less may be replaced with carbon black fine particle powder.

As the binder resin, a vinyl polymer obtained by polymerizing or copolymerizing vinyl monomers such as styrene, alkyl acrylate and alkyl methacrylate can be used. Examples of the styrene monomer include styrene and a substituted product thereof. Examples of the alkyl acrylate monomer include acrylic acid, methyl acrylate, ethyl acrylate, and butyl acrylate. The copolymer preferably contains 50 to 95% by weight of a styrene component.

If necessary, the binder resin may be a polyester resin, an epoxy resin, or the like together with the vinyl polymer.
A polyurethane resin or the like can be used in combination.

The fluidity of the black toner according to the present invention has a fluidity index of 70 to 100, preferably 75 to 100. In particular, the black composite non-magnetic particle powder is contained inside the composite particles and exposed to the composite particle surface,
Further, in the case of the black toner according to the present invention adhered to and present on the surface of the composite particles, more excellent fluidity is obtained, and a fluidity index in the range of 80 to 100 is obtained. When the fluidity index of the black toner is less than 70, it is difficult to say that the fluidity is sufficient.

The blackness of the black toner according to the present invention has an L ^* value of 40.0 or less. If it exceeds 40.0, the lightness increases and the blackness is not sufficient. A preferred upper limit of the blackness is an L ^* value of 35.0, more preferably 30.0. As the lower limit, the L ^* value is about 16.0.

The volume resistivity of the black toner according to the present invention is 1.0 × 10 ¹³ Ω · cm or more, preferably 5.0 × 10 ¹³ Ω · cm.
× 10 ¹³ Ω · cm or more. In particular, in the case of the black toner according to the present invention in which the black composite non-magnetic particle powder is contained inside the composite particle and exposed on the surface of the composite particle, and further adhered to and exist on the surface of the composite particle, 0.0 × 1
A higher volume resistivity value of at least 0 ¹⁴ Ω · cm can be obtained. The volume resistivity of the black toner is 1.0 × 10 ¹³ Ω ·
When the particle size is less than 1 cm, the charge amount tends to change depending on the usage environment of the toner, and the characteristics tend to be unstable. The upper limit is less than 1.0 × 10 ¹⁷ Ω · cm.

Next, a method for producing the black composite nonmagnetic particle powder according to the present invention will be described.

The granular manganese-containing hematite particles, which are the isotropic core particles according to the present invention, are a suspension containing a ferrous hydroxide colloid obtained by reacting an aqueous ferrous salt solution with an alkali hydroxide. Oxidation is carried out by passing an oxygen-containing gas through the liquid, so-called granular magnetite particle powder obtained by so-called wet method is coated with a manganese compound of 8 to 150 atomic% with respect to the total Fe, or the wet reaction is performed. F obtained by performing in the presence of manganese
It is obtained by heat-treating granular magnetite particles containing 8 to 150 atomic% of manganese with respect to e in air at 750 to 1000 ° C. The latter is preferable in consideration of the blackness of the obtained granular manganese-containing hematite particles.

The acicular or spindle-shaped manganese-containing hematite particle powder, which is the anisotropic core particle powder in the present invention, is 8 to 150 parts by mass based on the total Fe obtained by the method described later.
It can be obtained by subjecting acicular or spindle-shaped hydrous iron oxide particles containing atomic% of manganese to dehydration by heating at 400 to 800 ° C in air.

The needle-shaped or spindle-shaped manganese-containing iron hydroxide-containing particles, which are the anisotropic core particles in the present invention, are prepared by mixing an aqueous solution of ferrous salt with alkali hydroxide, alkali carbonate or alkali hydroxide / alkali carbonate. The oxygen-containing gas is passed through a suspension containing any of ferrous hydroxide colloid, iron carbonate and iron-containing precipitate obtained by reacting, and oxidized to oxidize the needle-like or spindle-shaped iron-containing hydrous iron oxide particles. Is produced by reacting in the presence of 8 to 150 atomic% of manganese with respect to the total Fe.

The adhesion / presence of the fine particle powder on the surface of the core particle powder is determined by comparing the core particle powder with Si, Zr, Ti, Al, C
The oxide fine particle powder or the hydrated oxide fine particle powder of e may be mechanically mixed and stirred, or the core particle powder and a colloid solution containing the fine particle powder may be mechanically mixed and stirred and then dried. Considering the uniform treatment of the fine particle powder on the surface of the core particle powder, it is preferable to use a colloid solution containing the fine particle powder.

As the fine particle powder, any of a synthesized powder and a commercially available powder can be used. Examples of the colloid solution containing fine particle powder include a colloid solution containing fine particle powder of silicon dioxide, zirconium oxide, hydrous zirconium oxide, titanium dioxide, aluminum oxide, hydrated alumina, cerium dioxide and the like.

Examples of the colloid solution containing Si oxide fine particle powder or hydrated oxide fine particle powder include Snowtex-XS, Snowtex-S, Snowtex UP, Snowtex-20, Snowtex-30, and Snowtex-40. , Snowtex-C, Snowtex-
N, Snowtex-O, Snowtex-SS, Snowtex-20L, Snowtex-OL, etc. (all trade names, manufactured by Nissan Chemical Industries, Ltd.) can be used. Considering the effect of improving the fluidity of the obtained black composite non-magnetic particle powder, Snowtex-XS, Snowtex-S, Snowtex UP and Snowtex-S
S is preferred.

The colloidal solution containing the Zr oxide fine particle powder or the hydrated oxide fine particle powder is NZS-20.
A, NZS-30A, NZS-30B, etc. (all are trade names, manufactured by Nissan Chemical Industries, Ltd.) can be used.

Examples of the colloidal solution containing Ti oxide fine particle powder or hydrated oxide fine particle powder include STS-01,
STS-02 or the like (all of which are trade names, manufactured by Ishihara Sangyo Co., Ltd.) can be used.

Examples of the colloidal solution containing Al oxide fine particle powder or hydrated oxide fine particle powder include AS-100,
AS-200, AS-520, etc. (all are trade names, manufactured by Nissan Chemical Industries, Ltd.) can be used.

A ceria sol solution (manufactured by Nissan Chemical Industries, Ltd.) can be used as a colloidal solution containing Ce oxide fine particle powder or hydrated oxide fine particle powder.

Amount of colloidal solution containing fine particle powder
Refers to the fine particles contained in the colloid solution
Particle powder is SiO_TwoConversion, ZrO_TwoConversion, TiO_TwoConversion,
Al_TwoO _ThreeConversion or CeO_Two0.1 to 50 parts by weight in conversion
A range is preferred. If less than 0.1 parts by weight, core particles
Due to the insufficient amount of fine powder relative to the powder,
Sufficiently improved fluidity of the resulting black composite nonmagnetic particle powder
It is difficult to make. If it exceeds 50 parts by weight,
Sufficiently improved fluidity of the resulting black composite nonmagnetic particle powder
Although it is possible to make
Easier to detach from the surface of the element, resulting in a volume resistivity
Value and the black toner production
The dispersibility in the adhesive resin may decrease.

In order for the fine particle powder to be uniformly present on the particle surface of the core particle powder, it is preferable to disintegrate the core particle powder in advance using a crusher. As a device for mixing and stirring, an edge runner, a Henschel mixer or the like can be used.

The conditions during mixing and stirring may be appropriately adjusted such as the proportion, linear load, stirring speed, and mixing and stirring time so that the fine particle powder is present as uniformly as possible on the particle surface of the core particle powder. 20 minutes or more are preferable.

The coating treatment of the core particle powder with the fine particle powder present on the particle surface with methylhydrogenpolysiloxane is performed by mechanically combining the core particle powder with the fine particle powder present on the particle surface and methylhydrogenpolysiloxane. What is necessary is just to mix and stir mechanically, or to mechanically mix and stir while spraying methylhydrogenpolysiloxane onto the core particle powder in which the fine particle powder is present on the particle surface. Almost all of the added methylhydrogenpolysiloxane is coated on the particle surface of the core particle powder in which the fine particle powder exists on the particle surface.

Next, fine particle powder is present on the particle surface,
Further, the core particle powder coated with methyl hydrogen polysiloxane is dried to obtain the black composite non-magnetic particle powder according to the present invention.

The addition amount of methyl hydrogen polysiloxane is preferably 0.1 to 50 parts by weight based on 100 parts by weight of the core particle powder having the fine particle powder on the particle surface. When the amount is less than 0.1 part by weight, the amount is insufficient to cover the core particle powder in which the fine particle powder is present on the particle surface. Since it is detached from the surface, it is difficult to obtain a black toner having excellent fluidity. Further, since the fine particle powder that cannot be completely covered with methyl hydrogen polysiloxane is exposed on the particle surface of the core particle powder, the volume specific resistance value of the obtained black composite nonmagnetic particle powder decreases. If the amount exceeds 50 parts by weight, the unevenness on the particle surface of the obtained black composite non-magnetic particle powder will not be clear, and the fluidity will decrease. Further, since the effect of improving the volume resistivity is saturated, there is no point in covering more than necessary.

The mixing and stirring conditions are as follows: the amount ratio, the linear load, the stirring speed, and the mixing and stirring time so that the methylhydrogenpolysiloxane is coated as uniformly as possible on the core particle powder in which the fine particle powder is present on the particle surface. Etc. may be appropriately adjusted, and the processing time is preferably 20 minutes or more.

The core particle powder may be selected from aluminum hydroxide, aluminum oxide, silicon hydroxide and silicon oxide, if necessary, before the fine particle powder is attached or present. It may be coated with two or more compounds.

The coating of aluminum with hydroxide or the like is as follows:
To an aqueous suspension obtained by dispersing the core particle powder, an aluminum compound, a silicon compound or both compounds are added and mixed and stirred, or, if necessary, by adjusting the pH value after mixing and stirring, The particle surface of the core particle powder is coated with one or two or more compounds selected from hydroxides of aluminum, oxides of aluminum, hydroxides of silicon and oxides of silicon, followed by filtration. Wash, dry and crush. If necessary, a degassing / consolidation treatment may be performed.

As the aluminum compound, aluminum salts such as aluminum acetate, aluminum sulfate, aluminum chloride and aluminum nitrate, and alkali aluminates such as sodium aluminate can be used.

The addition amount of the aluminum compound is 0.01 to 50% by weight in terms of Al with respect to the core particle powder.
If the amount is less than 0.01% by weight, it is difficult to coat the surface of the particles with a sufficient amount of aluminum hydroxide or the like to obtain a fluidity improving effect by a more uniform adhesion treatment of the fine particle powder. If it exceeds 50% by weight, the effect of improving the fluidity due to the coating is saturated, so that there is no point in adding more than necessary.

As the silicon compound, No. 3 water glass, sodium orthosilicate, sodium metasilicate and the like can be used.

The addition amount of the silicon compound is 0.01 to 50% by weight in terms of SiO _{2 with} respect to the core particle powder. 0.
If the amount is less than 01% by weight, it is difficult to coat the surface of the particles with a sufficient amount of silicon oxide or the like to obtain a fluidity improving effect by a more uniform adhesion treatment of the fine particle powder. If it exceeds 50% by weight, the effect of improving the fluidity due to coating is saturated, so that there is no point in adding more than necessary.

When the aluminum compound and the silicon compound are used in combination, the amount added is based on
The total of the reduced amount and the reduced amount of SiO ₂ is preferably 0.01 to 50% by weight.

Next, a method for producing the black toner according to the present invention will be described.

The black toner according to the present invention, in which the black composite non-magnetic particle powder is contained inside the composite particles and is exposed on the surface of the composite particle particles, has a predetermined amount of binder resin and a predetermined amount of black resin. It can be manufactured by a known method of mixing, kneading, and pulverizing the composite nonmagnetic particle powder. Specifically, a black composite non-magnetic particle powder and a binder resin,
After the mixture to which a release agent, a colorant, a charge control agent, and other additives are added as necessary, the mixture is sufficiently mixed by a mixer, and then the resin and the like are melted and kneaded by a heating kneader to make them compatible. The black composite non-magnetic particles and the like are dispersed therein, and then cooled and solidified to obtain a resin kneaded material. The resin kneaded material is pulverized and classified to obtain a black toner having a desired particle size.

As the mixer, a Henschel mixer, a ball mill or the like can be used. As the heating kneader, a roll mill, a kneader, a twin-screw extruder, or the like can be used. The pulverization can be performed by a pulverizer such as a cutter mill and a jet mill, and the classification can also be performed by a known air classification as described in Japanese Patent No. 2683142.

As a method other than the above known methods, there are a suspension polymerization method and an emulsion polymerization method. In the suspension polymerization method,
A monomer obtained by dissolving or dispersing a polymerizable monomer and a black composite nonmagnetic particle powder, if necessary, further adding a colorant, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives. The composition can be added to the aqueous phase containing the suspension stabilizer with stirring and granulated and polymerized to form a black toner having the desired particle size.

In the emulsion polymerization method, the monomer and the black composite non-magnetic particle powder are added with a colorant, a polymerization initiator and the like, if necessary, in water to add a desired emulsifier during the polymerization process. Black toner having a particle size of

The black toner according to the present invention, in which the black composite non-magnetic particle powder adheres to the composite particle surface, is known by mixing a predetermined amount of the composite particle and a predetermined amount of the black composite non-magnetic particle powder. It can be manufactured by the method described above. Specifically, it can be obtained by sufficiently mixing the black composite nonmagnetic particle powder and the composite particles with a mixer. As the mixer, a Henschel mixer,
A ball mill or the like can be used.

[0114]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment of the present invention is as follows.
It is as follows.

The average particle diameter or average major axis diameter and average minor axis diameter of each of the core particle powder and the black composite non-magnetic particle powder are as follows:
Electron micrographs (× 20000) were magnified 4 times in the vertical and horizontal directions, respectively, and about 350 particles shown in the photographs were measured in the fixed direction diameter, and the average value was shown.

The sphericity was represented by the ratio between the average longest diameter and the average shortest diameter of the isotropic particle powder, and the axial ratio was represented by the ratio between the average major axis and the average minor axis of the anisotropic particle powder.

The geometric standard deviation of the particle size of the core particle powder and the black composite non-magnetic particle powder was indicated by the value obtained by the following method. That is, a value obtained by measuring the particle diameter (major axis diameter) of the particles shown in the above enlarged photograph is calculated from the measured value and the actual particle diameter (major axis diameter) and the number of the particles are calculated by a statistical method. The horizontal axis represents the particle diameter (major axis diameter) of the particles on the logarithmic normal probability paper, and the vertical axis represents the cumulative number of particles belonging to each of the predetermined particle diameter (major axis diameter) sections (under the integrated screen) in percentage. I do.

From the graph, it is found that the number of particles is 50.
% And a particle diameter (major axis diameter) corresponding to 84.13%, respectively, and a geometric standard deviation value = 8 under the integrated screen.
4. Particle size at 13% (major axis diameter) / Under integrated screen 5
The value was calculated according to the particle diameter (major axis diameter) (geometric mean diameter) at 0%. The closer the geometric standard deviation value is to 1, the more
It means that the particle size distribution of the particle diameter (major axis diameter) of the particle powder is excellent.

The specific surface area was indicated by a value measured by the BET method.

The amount of Mn present inside the core particle powder or on the surface of the particle, and the amount of Al coated on the particle surface of the core particle powder.
Amount and Si amount, Si present on the particle surface of the core particle powder
The amount, the amount of Al, the amount of Ti, the amount of Zr and the amount of Ce, and the amount of Si contained in the methylhydrogenpolysiloxane coated on the particle surface of the core particle powder are each described in "Fluorescent X-ray Analyzer 3063M Type" ( Using Rigaku Denki Kogyo Co., Ltd.), the measurement was performed in accordance with JIS K0119 “General rules for X-ray fluorescence analysis”.

The silicon oxide, silicon hydroxide, Si oxide fine particle powder, Si hydrated oxide fine particle powder, and methylhydrogenpolysiloxane which are coated on the particle surface of the core particle powder are present. Each S of contained Si
The i amount is shown as a value obtained by measuring the amount of Si at each stage after the treatment process, and subtracting the amount of Si measured at the stage before the treatment process from the measured value. Aluminum hydroxide, aluminum oxide, Al that is coated on the surface of the core particles
The Al content of each of the oxide fine particle powder and the hydrated oxide fine particle powder of Al is also shown by the value obtained in the same manner as the above-mentioned Si content.

The fluidity of the core particle powder, the black composite non-magnetic particle powder and the black toner was measured using a powder tester (trade name, manufactured by Hosokawa Micron Corporation) using the angle of repose (degree), the degree of compression (%), the degree of spatula ( Degree) and agglomeration degree were measured, each index was obtained by replacing each measured value with the same reference value, and the resulting index was indicated by a total fluidity index. The closer the fluidity index is to 100, the better the fluidity is.

The blackness of the core particle powder, the black composite non-magnetic particle powder and the black toner was 0.5 g for the sample and 1.5 for castor oil.
cc and kneaded with a Hoover-type muller to make a paste,
Add 4.5g of clear lacquer to this paste, knead,
A coated piece that was made into a paint and applied on a cast-coated paper using a 6 mil applicator (coating thickness: about 30 μm)
And a multi-light source spectrophotometer MSC
The measurement was performed using -IS-2D (manufactured by Suga Test Instruments Co., Ltd.), and represented by a color index L ^* according to JIS Z8729.

Here, the L ^* value represents lightness, and the smaller the L ^* value, the better the blackness.

The volume resistivity of the core particle powder, the black composite non-magnetic particle powder and the black toner was determined by the following method.

First, 0.5 g of a sample was weighed, and was measured at 140 K using a KBr tablet molding machine (manufactured by Shimadzu Corporation).
g / cm ^{2 to} form a cylindrical sample to be measured, and the sample to be measured is heated to a temperature of 25 ° C. and a relative humidity of 60%.
After being exposed to the environment for 12 hours or more, the sample to be measured is set between stainless steel electrodes, and an electric resistance measuring device (m
model 4329A manufactured by Yokogawa Hokushin Electric Co., Ltd.)
A resistance value R (Ω) was measured by applying a voltage of 5 V.

Next, the area A (cm ² ) and the thickness t (cm) of the upper surface of the measured (columnar) sample were measured, and the measured values were inserted into the following equations to obtain the volume resistivity X (Ω).・ C
m) was determined. X (Ω · cm) = R × (A / t)

The average particle size of the black toner is measured by a laser diffraction particle size distribution analyzer (model HELOSLA / K
A, manufactured by SYMPATEC).

The dispersibility of the black composite non-magnetic particles in the binder resin was determined by photographing a cross section of the obtained black toner using an optical microscope (BH-2, manufactured by Olympus Optical Co., Ltd.). Judgment was made by counting the number of undispersed aggregated particles in a micrograph (× 200 magnification), and the evaluation was made in five steps. 5 indicates that the dispersion state is the best. 1: 0.25 mm 50 or more per ² 2: 0.25 mm less than 50 10 or more per ² 3: 0.25 mm ² per 5 or more 10 than 4: 1 or more per 0.25 mm ² Less than 5 5: No undispersed material was found

<Production of Black Composite Non-Magnetic Particle Powder> Granular manganese-containing hematite particle powder (average particle diameter 0.30 μm, sphericity 1.3, geometric standard deviation value) shown in the electron micrograph (× 20000) of FIG. 1.46, BET specific surface area 3.6 m ² / g, Mn content 13.3% by weight, fluidity index 36, blackness L ^* value 22.6, volume specific resistance 3.8
20 kg of × 10 ⁷ Ω · cm) were brought into contact with 150 liters of pure water using a stirrer to disperse the coagulation.
The mixture was passed through a "K pipeline homomixer" (product name, manufactured by Tokushu Kika Kogyo Co., Ltd.) three times to obtain a slurry containing granular manganese-containing hematite particles.

Next, the slurry containing the granular manganese-containing hematite particles was washed 5 times with a horizontal sand grinder “Mighty Mill MHG-1.5L” (product name, manufactured by Inoue Seisakusho Co., Ltd.) at 2000 rpm. By passing, a dispersion slurry containing granular manganese-containing hematite particles was obtained.

The obtained dispersion slurry was 325 mesh
The sieve residue at (opening 44 μm) was 0%. The dispersion slurry was separated by filtration and washed with water to obtain a cake of granular manganese-containing hematite particles. After drying the cake of the granular manganese-containing hematite particle powder at 120 ° C., 11.0 kg of the dried powder is transferred to an edge runner “MPU
V-2 "(product name, manufactured by Matsumoto Casting Ironworks Co., Ltd.) and mixed and stirred at 30 kg / cm for 30 minutes to loosen the aggregation of particles.

Next, a colloidal silica solution (SiO ₂₎ containing silicon oxide fine particles having an average particle diameter of 0.005 μm was used.
2750 g of Snowtex-XS (trade name, manufactured by Nissan Chemical Industry Co., Ltd.) was added to the above-mentioned granular manganese-containing hematite particles which had been deagglomerated while operating an edge runner.
By mixing and stirring at a linear load of kg / cm for 60 minutes, the silicon oxide fine particles were adhered to the surface of the manganese-containing hematite particles. As a result of the fluorescent X-ray analysis, the obtained black particle powder was found to have an abundance of silicon oxide fine particles of 4.52% by weight in terms of SiO _{2 with} respect to the granular manganese-containing hematite particles having the silicon oxide fine particles. Met.

The electron micrograph (× 2000) shown in FIG.
As shown in 0), since the presence of the added silicon oxide fine particle powder was not recognized, it was recognized that almost all of the added silicon oxide fine particle powder was present on the particle surface of the granular manganese-containing hematite particle powder. Was.

Next, methyl hydrogen polysiloxane TSF484 (trade name, manufactured by Toshiba Silicone Co., Ltd.)
550 g was added over 10 minutes while operating the edge runner, and further mixed and stirred at a linear load of 60 kg / cm for 60 minutes to obtain granular manganese-containing hematite particles having fine silicon oxide particles on the particle surfaces. The particle surface of the powder is coated with methyl hydrogen polysiloxane, and then dried at 80 ° C. for 180 minutes using a drier to volatilize residual moisture and the like, and the particle surface of the granular manganese-containing hematite particles is mixed with methyl. Black composite non-magnetic particle powder in which silicon oxide fine particle powder was present between the coating and the hydrogen polysiloxane coating was obtained.

This black composite non-magnetic particle powder
Methyl high as shown in the micrograph (× 20000).
Silicon oxide after coating with drogen polysiloxane
Since the presence of elementary fine particle powder was not recognized,
Almost all silicon oxide fine particle powder contains granular manganese.
Particle surface and methyl hydrogen of hematite particles
Adhesion / existence with polysiloxane coating
Was observed. Average of the obtained black composite nonmagnetic particle powder
Particle size 0.31 μm, sphericity 1.3, geometric standard deviation
The value is 1.46, BET specific surface area is 14.6m^Two/ G, flow
Mobility index is 51, blackness L^*Value is 22.8, volume specific resistance
The resistance value is 3.6 × 10^TenΩ · cm. X-ray fluorescence analysis
As a result, the coverage of methyl hydrogen polysiloxane
Is SiO _TwoIt was 4.66% by weight in conversion.

For reference, the powder was obtained by mixing and stirring with a powder mixer for 30 minutes using the granular manganese-containing hematite particles and the colloidal silica solution containing the silicon oxide particles. FIG. 4 shows an electron micrograph (× 20000) of the obtained black particle powder. As shown in FIG. 4, the silicon oxide fine particle powder did not adhere to or exist on the particle surface of the granular manganese-containing hematite particles, and was confirmed to be a mixed particle powder with the granular manganese-containing hematite particles.

<Production of Black Toner Using Black Composite Non-Magnetic Particle Powder><Black Toner (I)>
0 g, styrene-butyl acrylate-methyl methacrylate copolymer resin (molecular weight 150,000, styrene /
Butyl acrylate / methyl methacrylate = 87.0
/12.5/0.5), 765 g of polypropylene wax (molecular weight: 3,000) and 85 g of a charge controlling agent were charged into a Henschel mixer and stirred and mixed at a bath temperature of 60 ° C. for 15 minutes to obtain a mixture. The obtained mixture is melt-kneaded at 140 ° C. in a continuous twin-screw kneader (T-1) to obtain a kneaded product, and then the kneaded product is cooled in air, roughly pulverized, finely pulverized, and then classified. , Black toner (I)
I got

The obtained black toner (I) has an average particle diameter of 10.1 μm, a dispersibility of 5, a fluidity index of 78, a blackness of L ^* 23.1, and a volume resistivity of 6.8 × 10 ¹⁴ Ω.・ Cm
Met.

<Black Toner (II)> Granular manganese-containing hematite particle powder (sphericity: 1.3, average particle diameter: 0.1
30 μm, geometric standard deviation value 1.46, BET specific surface area value 3.6 m ² / g, Mn content 13.3% by weight, fluidity index 36, blackness L ^* value 22.6, volume resistivity value 3. 8
× 10 ⁷ Ω · cm) 150 g, styrene-butyl acrylate-methyl methacrylate copolymer resin (molecular weight 13
000, styrene / butyl acrylate / methyl methacrylate = 82.0 / 16.5 / 1.5) 765
g, polypropylene wax (molecular weight 3,000) 85
g and 15 g of the charge control agent were charged into a Henschel mixer, and stirred and mixed at a bath temperature of 60 ° C. for 15 minutes to obtain a mixture. The obtained mixture is mixed with a continuous twin-screw kneader (T-
The melt-kneading is performed at 140 ° C. in 1) to obtain a kneaded material,
Next, the kneaded product was cooled in air, coarsely pulverized, and finely pulverized, and then classified to obtain composite particles.

101.5 g of the obtained composite particles and 1.0 g of the black composite non-magnetic particle powder were mixed with a desktop mini pulverizer D1.
The mixture was dispersed and mixed for 1 minute in 50A (manufactured by Taninaka Co., Ltd.), and the black composite non-magnetic particles were adhered to the surface of the composite particles to obtain a black toner (II).

The obtained black toner (II) has an average particle diameter of 10.0 μm, a fluidity index of 76, a blackness L ^* value of 22.9, and a volume resistivity value of 5.6 × 10 ¹⁴ Ω ·. cm
Met.

<Black Toner (III)> 101.5 g of the black toner (I) and 1.0 g of the black composite non-magnetic particle powder were mixed with a desktop mini pulverizer D150A (TANINAKA CORPORATION).
And mixed for 1 minute, and the black composite non-magnetic particle powder was adhered to the surface of the black toner (I) to obtain a black toner (III).

The obtained black toner (III) has an average particle size of 10.1 μm, a fluidity index of 89, a blackness L ^* value of 21.8, and a volume resistivity value of 9.8 × 10 ¹⁴ Ω ·. c
m.

[0145]

The most important point in the present invention is that the surface of the black hematite particles or the particles of the iron oxide hydroxide particles and, if necessary, the hydroxide of aluminum and the oxidation of aluminum coated on the surface of the particles of the particle powder. Fine particles between any one surface of one or more compound-coated surfaces selected from the product, silicon hydroxide and silicon oxide, and methylhydrogenpolysiloxane coating the surface. Average particle size of powder present 0.08 to
The 1.0 μm black composite non-magnetic particle powder has excellent fluidity and can suppress a decrease in the charge amount of the black toner even when contained in a large amount in the black toner. Is the fact that it has a value.

Regarding the reason why the black composite non-magnetic particle powder according to the present invention is excellent in fluidity, the present inventor has determined that the fine particle powder is uniform on the particle surface of the black hematite particle powder or the black iron oxide hydroxide particle powder, and It is considered that the presence of a large amount results in formation of many fine irregularities.

Although the reason why the volume resistivity of the black composite non-magnetic particles according to the present invention is high is not yet clear, the present inventor has found that the fine particle surface When only the powder is present, when the particle surface of the core particle powder is coated only with methyl hydrogen polysiloxane, the particle surface of the core particle powder is coated with methyl hydrogen polysiloxane, and the fine particle powder is coated on the coating. When present, a specific amount of silicon oxide fine particle powder is present between the particle surface of the core particle powder and the methylhydrogenpolysiloxane coating the particle surface, but the amount of methylhydrogenpolysiloxane If the fine particle powder is not sufficiently coated, the specific volume of methyl hydrogen cannot be obtained. It is believed to be due to synergistic effect with the fine particles being covered with polysiloxane and the methyl hydrogen polysiloxane.

The black composite non-magnetic particles according to the present invention are transparent because the fine particles and the methyl hydrogen polysiloxane are transparent, so that the black hematite particles or the black iron oxide hydroxide particles which are the core particles are black. Since it does not reduce the blackness, it has an excellent blackness comparable to the blackness of the black hematite particles or the black iron oxide hydroxide particles.

The inventor of the present invention concluded that the reason why it is possible to suppress a decrease in the charge amount of the black toner even when a large amount of the black composite non-magnetic particle powder according to the present invention is contained, is that the black toner according to the present invention can be suppressed. The composite non-magnetic particle powder, as described above,
This is considered to be due to the fact that the particle powder itself has a high volume resistivity.

The black toner according to the present invention has excellent fluidity and a high volume resistivity even when the black composite nonmagnetic particles are contained in a large amount. is there.

Regarding the reason why the fluidity of the black toner according to the present invention is excellent, the present inventor has proposed that the black composite non-magnetic particle powder in which the fine particle powder is uniformly present is blended with the black toner to obtain the black toner. This is considered to be due to the formation of a large number of fine irregularities on the toner surface.

The reason why the black toner according to the present invention has a high volume resistivity value is as follows.
Instead of carbon black fine particle powder having a low volume resistivity value of about 0 Ω · cm, 3.0 × 10 ⁸ Ω · cm
This is considered to be due to the fact that the black composite non-magnetic particle powder according to the present invention having the above-mentioned high volume specific resistance was blended into the black toner.

[0153]

Next, examples and comparative examples will be described.

Core Particle Powders 1 to 4 Various black hematite particles or black iron oxide hydroxide particles obtained by a known production method were prepared, and the coagulation was broken in the same manner as in the embodiment of the present invention. A black hematite particle powder or a black iron oxide hydroxide particle powder was obtained.

Table 1 shows the characteristics of the black hematite particles or the black iron oxide hydroxide particles.

[0156]

[Table 1]

Core Particles 5 Manganese-containing hematite particles were prepared in the same manner as in the embodiment of the present invention, using 20 kg of granular manganese-containing hematite particles (core particle powder 1) whose coagulation was loosened and 150 l of water. A slurry containing the powder was obtained. The pH value of the redispersed slurry containing the obtained granular manganese-containing hematite particles was adjusted to 1 using an aqueous sodium hydroxide solution.
The slurry was adjusted to 0.5, and then water was added to the slurry to adjust the slurry concentration to 98 g / l. 150 liters of this slurry
Is heated to 60 ° C., and 1.0 mol
Per liter of a NaAlO ₂ solution (corresponding to 1.0% by weight in terms of Al with respect to granular gangan-containing hematite particles), and the mixture was held for 30 minutes, and then the pH value was adjusted to 7.5 with acetic acid. Was adjusted. After maintaining in this state for 30 minutes, filtration, washing with water, drying, and pulverization were performed to obtain granular manganese-containing hematite particles whose surface was covered with aluminum hydroxide.

Table 2 shows the main production conditions at this time, and Table 3 shows various characteristics of the obtained manganese-containing hematite particles having a surface coated with aluminum hydroxide.

[0159]

[Table 2]

[0160]

[Table 3]

Core Particle Powder 6 to 8 Surface-treated black hematite particles or black hydrous oxide in the same manner as the above-mentioned core particle powder 5 except that the type of core particles and the type and amount of additives in the surface treatment step were variously changed. An iron particle powder was obtained.

Table 2 shows the main treatment conditions at this time, and Table 3 shows various properties of the obtained surface-treated core particle powder.

Examples 1 to 14, Comparative Examples 1 to 5 Types of core particle powder, presence / absence, type and amount of colloidal solution containing fine particle powder in the step of attaching fine particle powder, treatment conditions by edge runner, methylhydrogen Black composite non-magnetic particles were obtained in the same manner as in the embodiment of the invention except that the kind and amount of methylhydrogenpolysiloxane and the treatment conditions with an edge runner were variously changed in the step of attaching the genpolysiloxane. The black composite non-magnetic particle powder obtained in each of Examples 1 to 14 shows almost no fine particle powder as a result of electron microscopic observation. And the presence of methylhydrogenpolysiloxane coating.

The electron micrographs of the black composite non-magnetic particles obtained in Examples 9 to 12 are shown in FIGS. 5 to 8.

In Comparative Example 5, the surface of black hematite particles was coated with methylhydrogenpolysiloxane, and then silicon oxide fine particles were present.

Table 4 shows the types and various characteristics of the fine particle powders used.

Table 5 shows the main processing conditions at this time, and Table 6 shows the properties of the obtained black composite nonmagnetic particle powder.

[0168]

[Table 4]

[0169]

[Table 5]

[0170]

[Table 6]

<Production of Black Toner> Examples 15 to 28 and Comparative Examples 6 to 14 The black composite nonmagnetic particle powders and core particles 1 of Examples 1 to 14 were prepared.
Black toner (I) according to the embodiment of the present invention, except that the black non-magnetic particle powders of Comparative Examples 1 to 5 were used and the blending amounts of the black composite non-magnetic particle powder and the binder resin were changed. A black toner was obtained in the same manner as described above.

Tables 7 and 8 show the main production conditions and various characteristics of the black toner obtained at this time.

[0173]

[Table 7]

[0174]

[Table 8]

Examples 29 to 42 Types of black nonmagnetic particle powder to be contained / exposed to composite particles, types and amounts of black composite nonmagnetic particles to be adhered to the surface of composite particles, and content / exposed to composite particles The black toner (I) described in the embodiment of the present invention, except that the blending amounts of the black non-magnetic particle powder and the binder resin are variously changed.
A black toner was obtained in the same manner as in I).

Table 9 shows the main production conditions and various characteristics of the obtained black toner.

[0177]

[Table 9]

Examples 43 to 56 Except that the type of the composite particles and the type and amount of the black composite non-magnetic particles to be adhered to the composite particles were variously changed,
A black toner was obtained in the same manner as in the black toner (III) described in the embodiment of the present invention.

Table 10 shows the main production conditions and various characteristics of the obtained black toner.

[0180]

[Table 10]

Examples 57 to 60 As the black nonmagnetic particle powders contained and exposed in the composite particle powder, the black composite nonmagnetic particle powders of Examples 1 to 4 and the core particle powders 1 to 4 were used. Except that the compounding amounts of the magnetic particle powder and the core particle powder and the compounding amounts of the black non-magnetic particle powder and the binder resin were variously changed, the same as in the black toner (I) described in the embodiment of the present invention. A black toner was obtained.

Table 11 shows the main production conditions and various properties of the obtained black toner.

[0183]

[Table 11]

Examples 61 to 70 The black non-magnetic particle powders of Examples 5 to 14 and the black non-magnetic particle powders of core particles 1 to 8 were used as the black non-magnetic particle powders contained and exposed in the composite particles. Examples 1 to 4 as black composite nonmagnetic particle powder to be attached to the composite particle surface
10 black composite non-magnetic particle powder, except that the compounding amount of the black non-magnetic particle powder contained and exposed in the composite particle powder and the binder resin was changed, A black toner was obtained in the same manner as in the toner (III).

Table 12 shows the main production conditions and various characteristics of the obtained black toner.

[0186]

[Table 12]

[0187]

The black composite non-magnetic particle powder according to the present invention has excellent fluidity and a high volume resistivity, so that high-quality and high-speed black composite non-magnetic particle powder for black toner can be obtained. It is suitable as.

Further, the black composite non-magnetic particle powder according to the present invention has excellent fluidity, is easy to handle, has excellent workability, and is industrially preferable.

The black toner using the black composite non-magnetic particles having excellent fluidity and high volume resistivity also has excellent fluidity and high volume resistivity. Therefore, it is preferable as a high-quality, high-speed insulating or high-resistance black toner.

[Brief description of the drawings]

FIG. 1 is an electron micrograph (× 20,000) showing a particle structure of a granular manganese-containing hematite particle powder used in an embodiment of the present invention.

FIG. 2 is an electron micrograph (×) showing the particle structure of granular manganese-containing hematite particles having silicon oxide fine particles present on the surface of the particles obtained in the embodiment of the invention.
20000).

FIG. 3 is an electron micrograph (× 2000) showing the particle structure of the black composite nonmagnetic particle powder obtained in the embodiment of the invention.
0).

FIG. 4 is an electron micrograph (× 20000) showing the particle structure of a mixed particle powder of a granular manganese-containing hematite particle powder and a silicon oxide fine particle powder.

FIG. 5 is an electron micrograph (× 20000) showing the particle structure of the black composite nonmagnetic particle powder obtained in Example 9.

FIG. 6 is an electron micrograph (× 20000) showing the particle structure of the black composite nonmagnetic particle powder obtained in Example 10.

FIG. 7 is an electron micrograph (× 20000) showing the particle structure of the black composite nonmagnetic particle powder obtained in Example 11.

FIG. 8 is an electron micrograph (× 20000) showing the particle structure of the black composite nonmagnetic particle powder obtained in Example 12.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroko Morii 4-1-2, Funariminami, Naka-ku, Hiroshima-shi, Hiroshima Toda Kogyo Co., Ltd.

Claims (3)

[Claims] 1. The method according to claim 1, wherein Si, Z is present between the particle surface of the black hematite particles or the black iron oxide hydroxide particles and the methyl hydrogen polysiloxane coating the particle surfaces.
r, Ti, Al and Ce, one or two or more types of fine particles of oxides or fine particles of hydrated oxides of the elements of each element are present.
A black composite non-magnetic particle powder for black toner, comprising 0 μm black composite non-magnetic particle powder. 2. Black hematite particle powder or black hydrate coated with one or two or more compounds selected from aluminum hydroxide, aluminum oxide, silicon hydroxide and silicon oxide. Iron oxide particle powder, between the compound-coated surface and methylhydrogenpolysiloxane further coating the compound-coated surface, oxide fine particle powder of each element of Si, Zr, Ti, Al and Ce A black composite nonmagnetic particle powder having an average particle diameter of 0.08 to 1.0 [mu] m in which one or more kinds of hydrated oxide fine particle powders are present. Black composite non-magnetic particle powder for use. 3. A black toner using the black double non-magnetic particle powder according to claim 1.