JP2003323006A - Toner for electrostatic image development - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic image development which employs a black colorant free from toxic substance and exhibits stable charging behavior even after extended use or printing of a large number of sheets, and thus making it possible to provide printed images having sufficient image density without causing toner scattering, fog and fluctuation in image density. <P>SOLUTION: The toner for electrostatic image development contains a binder resin, a colorant and an electrification controlling agent. The colorant is made of black fine particles obtained by coating the surface of titanium dioxide particles with a compound oxide of titanium and iron. The electrification controlling agent contains at least one kind of compound selected from a nigrosine dye, modified nigrosine dyes and triphenylmethane dyes and a compound having a quaternary ammonium salt structure. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing device in a wide range from low speed to high speed, with less background stain.
The present invention relates to a black electrostatic image developing toner that can provide a high-quality image and that does not contain harmful substances.

[0002]

2. Description of the Related Art Conventionally, carbon black and black iron oxide have been mainly used as black pigments used in toners for developing electrostatic images. Carbon black is generally inexpensive, has a fine powder particle size, and is an excellent pigmentability. However, carbon black has a bulk density of 0.1 g / c.
Since the powder was m ^3, which was bulky, it was difficult to handle and the workability was poor. Further, carbon black is classified into Group 2B (possibly carcinogenic to the human body) by the International Cancer Research Institute, and other problems from the viewpoint of health and safety have been pointed out.

On the other hand, black iron oxide powder has cohesiveness due to the fact that Fe ₃ O ₄ has magnetism, and when mixed with other toner raw materials, uniform mixing is difficult, and There is a defect that the heat resistance is inferior such as changing to brown Fe ₂ O ₃ at about 150 ° C.

By the way, the characteristics required for the black colorant used in the toner for developing an electrostatic image are colorability and
In addition to safety, handleability during manufacturing, and heat resistance, there are electrical characteristics that affect development characteristics. The electrical characteristics are one of the important characteristics required for the colorant. When the electrical characteristics are further subdivided and listed, the charging rising characteristics, the characteristics of holding the charging for a long time, the charging uniformity (charging amount distribution), the charging environmental stability, and the like can be mentioned. Various factors may be mentioned as factors that affect the electrical characteristics, and examples thereof include dispersibility of the colorant, electric resistance value, and surface properties of the colorant. If the electrical properties of the colorant are poor, the charge amount of each toner particle becomes non-uniform and the charge amount distribution is widened. In addition, the proportion of the oppositely charged particles or the weakly charged particles increases, which causes the scattering of the toner inside the machine during development and the fog phenomenon in which the toner adheres to the non-image portion of the printed matter. Furthermore, the toner tends to be inferior in durability because the image density, resolution, and the like fluctuate in the printing for a long time or in a large number of copies.

Various materials have been studied to solve the drawbacks of carbon black or black iron oxide and replace them. Among them, Japanese Patent Laid-Open No. 3-2
No. 276, Fe ₂ TiO ₅ and Fe ₂ O ₃ —Fe.
A black particle powder composed of polycrystalline particles having a mixed composition with a TiO ₃ solid solution has been proposed, and a technique relating to a toner using the same has been disclosed. However, the purpose of the publication is to provide a black colorant that is safe, harmless, and has excellent workability and heat resistance, and the electrical characteristics of the toner using the black particle powder are not satisfactory. Absent. Further, the blackness as a black colorant is not sufficient, and therefore, in order to achieve a satisfactory blackness of the toner, a large amount of the black particle powder must be used. Such toner has an increased specific gravity, and is liable to cause the toner to be scattered inside the machine due to the centrifugal force that is agitated with the carrier in the developing device or when the developing sleeve rotates.

Further, in Japanese Patent Laid-Open No. 2000-319021, a black particle powder containing iron oxide (magnetite) particles containing a titanium component in an amount of 0.3 to 3.5% by weight in terms of titanium atom, and a toner using the same. Is proposed. In JP-A-8-34617, iron oxide (magnetite) is used.
The titanium component in the particles is 0.5 to 10.0 in terms of titanium atom.
There has been proposed a black magnetic iron oxide particle powder which is contained by weight%, and a toner using the same. However, since iron oxide (magnetite) has conductivity, it cannot hold sufficient charge in the toner, and because it has magnetism, particles are likely to agglomerate and have sufficient coloring power as a black toner. It is difficult to get things. Further, Japanese Patent Laid-Open No. 2002-129063 discloses a technique relating to a low magnetic black pigment powder having a particle structure in which a rutile TiO ₂ phase is used as a base and the base is coated with an Fe ₂ TiO ₄ phase, and this is used. Examples of toner are described. However, this publication does not disclose a toner that suppresses toner scattering and fog phenomenon and does not fluctuate in image density and resolution during long-term printing or printing a large number of copies.

As described above, in the prior art, the technology relating to the toner using the novel black colorant which can solve the drawbacks of carbon black or black iron oxide (magnetite) and further satisfy the electric characteristics of the toner is Not disclosed.

[0008]

[Patent Document 1] Japanese Patent Laid-Open No. 3-2276

[Patent Document 2] Japanese Patent Laid-Open No. 2000-319021

[Patent Document 3] Japanese Unexamined Patent Publication No. 8-34617

[Patent Document 4] Japanese Unexamined Patent Application Publication No. 2002-129063

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to use a black colorant containing no harmful substance and to use it for a long period of time or to use it in a large amount. Stable charging behavior is exhibited even when printing a number of copies, and as a result, there is no toner scattering or fog,
An object of the present invention is to provide a toner for developing an electrostatic charge image, which has a sufficient image density and is capable of obtaining a printed image with no fluctuation in the image density.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that black fine particles obtained by coating the surface of titanium dioxide particles with a layer of a composite oxide of titanium and iron. The inventors have found that the problems can be solved by using a toner containing a combination of specific charge control agents, and have completed the present invention.

That is, the present invention is a toner for developing an electrostatic charge image containing a binder resin, a colorant and a charge control agent, wherein the colorant coats the surface of titanium dioxide particles with a composite oxide of titanium and iron. Characterized in that the charge control agent contains at least one compound selected from a nigrosine dye, a modified nigrosine dye, and a triphenylmethane dye and a compound having a quaternary ammonium salt structure. The present invention provides a toner for developing an electrostatic charge image.

When the electrostatic image developing toner is used for a long period of time or when a large number of copies are printed, the desired image quality cannot be maintained and, for example, the image density fluctuates. When the image density changes, the thickness of the thin line and the size of the halftone dot also change, resulting in deterioration of print quality. The present inventors have studied variously in order to suppress the fluctuation of the image density of the toner for developing an electrostatic charge image using black fine particles in which the surface of titanium dioxide particles is coated with a composite oxide of titanium and iron as a colorant. Nigrosine dye as charge control agent, modified nigrosine dye,
Further, they have found that the object can be achieved by using at least one compound selected from the group consisting of triphenylmethane dye and a compound having a quaternary ammonium salt structure, and completed the present invention.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The colorant used in the present invention is titanium dioxide (TiO ₂ :
Titanium Dioxide) is a black fine particle whose surface is coated with a layer containing a composite oxide of titanium and iron. The colorant used in the present invention has a high degree of blackness by adopting such a constitution. In addition, there are various composition oxides as the composite oxide of titanium and iron. For example,
FeTiO ₃ , Fe ₂ TiO ₄ , Fe ₂ TiO _{5 and the} like. Among them, as the colorant used in the present invention, Fe ₂
A complex oxide of spinel structure represented by TiO ₄ (Iron T
It is preferably titanium spinel).

Since the hue of the black colorant used in the present invention changes depending on the particle size, the primary particle size is 0.05 to 0.4 μm.
m is more preferable, 0.1 to 0.4 μm is more preferable, and 0.15 to 0.3 μm is particularly preferable. The particle size of titanium oxide serving as the core of the colorant is preferably in the range of 0.02 to 0.38 μm, more preferably 0.08 to 0.38 μm, and 0.12 to 0.28 μm. It is particularly preferable that it is in the range. The shape may be spherical, acicular, or amorphous, but spherical is preferable from the viewpoint of fluidity.

Further, the hue of the layer containing the composite oxide of titanium and iron also changes depending on the content ratio of titanium and iron. When used as a black pigment, the weight ratio of Ti: Fe = 30:
The range is preferably 70 to 70:30, more preferably 45:55 to 55:45, and even more preferably 48:52 to 52:48.

The range of preferable physical properties of the black colorant used in the present invention is described below. Preferably the specific surface area by the BET method is in the range of 1.5~20m ² / g, and more preferably in the range of 3 to 10 m ² / g. The pH is preferably in the range of 5.5 to 8.5, and more preferably in the range of 6 to 8. The oil absorption is preferably 20 to 40 g / 100 g, and the water content is preferably 0.5 wt% or less. The bulk density is preferably 0.3 to 0.6 g / ml, and 0.3
More preferably, it is 5 to 0.55 g / ml.

The black colorant used in the present invention has a low magnetic property and thus is suitable as a colorant for non-magnetic toner. When used in a non-magnetic toner, the lower the magnetic properties, the more preferable. Hc (coercive force) is 40 kA / m or less, σs (saturation magnetization amount) is 20 Am ² / kg or less, and σr (residual magnetization amount) is 10 Am ² / kg. The following is preferable. The above magnetic characteristics are based on the vibrating sample magnetometer.
ter, VSM; manufactured by Riken Denshi Co., Ltd. (Applied magnetic field 3
97.9 kA / m).

Other conditions in the VSM measurement are as follows. Inner volume of sample cell: 56.55 mm ³ Sample amount: 85.0 to 96.1 mg Sample packing density: 1.50 to 1.70 g / cm ³ Measuring temperature: 22.5 ± 2.5 ° C. Measuring humidity: 50 ± 10%

Further, the colorant used in the present invention needs to have a high degree of blackness, and the L * a * b * color system (JIS
It is a color system standardized by Z 8729, L * represents lightness, and a * and b * represent chromaticity. ) L *
Is preferably 25 or less, and more preferably 20 or less. It is preferable that a * and b * are closer to 0, but practically, it is preferable that they are in the range of -3 to 3, respectively.

The L *, a * and b * of the colorant are measured by the following method. Spectral color difference meter (Nippon Denshoku Industries S
E-2000) powder cell filled with 3 g of colorant, 5
After tapping 5 times from a height of cm, its chromaticity is measured by a reflection method.

Further, the light reflectance which is preferable as the black colorant is 8% or less, and more preferably 6% or less in the entire wavelength region of light. When the reflectance is high in a specific wavelength range, the hue is biased, but when the reflectances are compared for each wavelength, if the difference between the maximum value and the minimum value of the reflectance is 3% or less, the hue is biased. Is preferred, which is preferable.

When printing is performed using the toner for developing an electrostatic image of the present invention, a spectroscopic color difference meter (Nippon Denshoku Industries Co., Ltd.) is used.
It is preferable to set the printing conditions such that L * = 35 or less, a * = − 3 to 3, and b * = − 3 to 3 as values measured by SE-2000).

Commercially available black colorants satisfying the above physical properties include, for example, ETB-100 and ETB-300 (all manufactured by Titanium Industry Co., Ltd.), which are preferable as the black colorant used in the present invention.

The amount of the black colorant used in the present invention is
The range of 3 to 18 parts by weight is preferable, and the range of 5 to 15 parts by weight is particularly preferable, per 100 parts by weight of the toner. When the amount is 18 parts by weight or less, the true specific gravity of the toner can be reduced, and the toner is less likely to scatter during development, which is preferable.

Although the above-mentioned black colorant is used in the present invention, a publicly known and commonly used colorant can be used for the purpose of adjusting the hue. For example, as the black colorant, carbon black such as furnace black, channel black, acetylene black, thermal black, lamp black and the like, which are classified by the manufacturing method, or C.I. I. Pi
gment Black 11 iron oxide pigment, aniline black, phthalocyanine cyanine black B
X and the like. The black colorant obtained by coating the surface of titanium oxide particles used in the present invention with a layer containing a composite oxide of titanium and iron is characterized by containing no harmful substances, and the object of the present invention also includes harmful substances. Since it is to provide a toner for developing an electrostatic image which does not exist, when carbon black is used in combination, it is necessary to pay sufficient attention to the content of harmful substances and the amount used in combination with the black colorant used in the present invention.

As a blue colorant, a phthalocyanine type C.I. I. Pigment Blue 15-3, an indanthrone type C.I. I. Pigment Blue 60,
As a red colorant, quinacridone type C.I. I. Pig
ment Red 122, an azo-based C.I. I. Pigme
nt Red 22, C.I. I. Pigment Red4
8: 1, C.I. I. Pigment Red 48: 3,
C. I. PigmentRed 57: 1 and the like, as a yellow colorant, an azo C.I. I. PigmentYell
ow 12, C.I. I. Pigment Yellow 1
3, C.I. I. Pigment Yellow 14, C.I.
I. Pigment Yellow 17, C.I. I. Pi
gment Yellow 97, C.I. I. Pigmen
t Yellow 155, an isoindolinone-based C.I.
I. Pigment Yellow 110, a benzimidazolone-based C.I. I. Pigment Yellow 1
51, C.I. I. Pigment Yellow 154,
C. I. Pigment Yellow 180 and the like.

The charge control agent used in the present invention is a compound having a quaternary ammonium salt structure and at least one compound selected from a nigrosine dye, a modified nigrosine dye and a triphenylmethane dye. These are 1 / 9-
The use ratio of 9/1 is preferable, and 2/8 to 8 /
More preferably, it is 2. Above all, 3/7 to 7/3
Is particularly preferable. The nigrosine dye and the triphenylmethane dye have high positive charge imparting ability, and when they are used alone, the fluctuation of the image density becomes large. The quaternary ammonium salt compound is not so high in charge imparting ability, but has a property of suppressing fluctuation in image density which is a drawback of the nigrosine dye and the triphenylmethane dye. By using both of them in the above ratio, the fluctuation of the image density during continuous printing is small, and a clear printed image without fog can be stably obtained.

Examples of nigrosine dyes include, for example, "NI
GROSINE BASE EX "," OIL BLA
CK BS ”,“ BONTRON N-01 ”,“ BO
NTRON N-07 ”(above, Orient Chemical Co., Ltd.) and the like,“ BON
"TRON N-04", "BONTRON N-21"
(End of Orient Chemical Co., Ltd.), "CHUO-3"
(Chuo Gosei Kagaku Co., Ltd.) and the like. Further, as triphenylmethane, "OIL BLUE" (Orient Chemical Co., Ltd.), "COPY BLUE PR"
(Clariant Co., Ltd.) and the like.

The quaternary ammonium salt compounds that can be preferably used in the present invention include compounds represented by the following formulas 1 to 3.

[Chemical 4] (Formula 1) [In formula, R < ₁ >, R < ₂ > and R < ₃ > respectively independently represent a C1-C10 alkyl group. ]

[0030]

[Chemical 5] (Equation 2) _wherein, R _1, R 2, _{R 3} and _{R 4} are, each independently, a hydrogen atom, an alkyl group or alkenyl group having 1 to 22 carbon atoms, unsubstituted or having 1 to 20 carbon atoms It represents a substituted aromatic group or an aralkyl group having 7 to 20 carbon atoms, and A ⁻ represents a molybdate anion or a tungstate anion, or a heteropolyacid anion containing a molybdenum or a tungsten atom. ]

[0031]

[Chemical 6] (Formula 3) (In the formula, m is an integer of 1 to 3, n is an integer of 0 to 2, X and Z are 1 or 2, Y is 0 or 1, and when X = 1, Y =
1, Z = 1, X = 2, Y = 0, Z = 2, M represents a hydrogen atom or a monovalent metal ion, R ₁ ,
R ₂ , R ₃ , and R ₄ are hydrogen atoms, a linear or branched saturated or unsaturated alkyl group having 1 to 30 carbon atoms, a compound of the formula [(-CH ₂ CH ₂ O) _p -R (where R is A hydrogen atom or an alkyl group having 1 to 4 carbon atoms or an acyl group, and p is an integer of 1 to 10)],
Represents a monocyclic or polycyclic aliphatic group having 5 to 12 carbon atoms, or a monocyclic or polycyclic aromatic group, wherein R _{5 to} R ₁₂ represent a hydrogen atom, a linear or branched group having 1 to 30 carbon atoms saturated or unsaturated alkyl group, an alkoxyl group having 1 to 4 carbon atoms or an expression _{[(-C q H 2q -O)} r -R, ( provided that
R is a hydrogen atom or an alkyl group or an acyl group having 1 to 4 carbon atoms, q is an integer of 2 to 5, and r is an integer of 1 to 10)]. }

More specifically, there are the following compounds.

[0033]

[Chemical 7] Compound (1-1)

[0034]

[Chemical 8] Compound (2-1)

[0035]

[Chemical 9] Compound (2-2)

[0036]

[Chemical 10] Compound (2-3)

[0037]

[Chemical 11] Compound (2-4)

[0038]

[Chemical 12] Compound (2-5)

[0039]

[Chemical 13] Compound (2-6)

[0040]

[Chemical 14] Compound (2-7)

[0041]

[Chemical 15] Compound (2-8)

[0042]

[Chemical 16] Compound (2-9)

[0043]

[Chemical 17] Compound (2-10)

[0044]

[Chemical 18] Compound (2-11)

[0045]

[Chemical 19] Compound (3-1)

[0046]

[Chemical 20] Compound (3-2)

The above charge control agents may be used alone or in combination, and are used in an amount of 0.3 to 0.3 with respect to the binder resin.
By containing 15 parts by weight, preferably 0.5 to 5 parts by weight, good charging performance can be obtained.

The binder resin used in the toner for developing an electrostatic image of the present invention can be used without particular limitation as long as it does not impair the object of the present invention. Specifically, a polystyrene-based resin, a styrene- (meth) acrylic acid ester copolymer resin, or a vinyl-based copolymer resin such as a styrene-conjugated diene copolymer resin, a polyester resin, an epoxy resin, Examples thereof include butyral resin, xylene resin, coumarone indene resin, and hybrid resin obtained by combining the above resins. Among them, vinyl-based copolymer resin, polyester resin, and epoxy resin are preferable, and fixability and resistance A polyester resin can be particularly preferably used because it has a good balance of offset property, transparency and the like.

The polyester resin preferably used in the present invention is (A) a dibasic polybasic acid compound (B) divalent polybasic acid and / or acid anhydride and / or a lower alkyl ester thereof (B) dibasic acid. It is obtained by dehydration condensation of the above polyhydric alcohol by a usual method.

Examples of the dibasic or higher polybasic acid and / or acid anhydride include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, and the like. Itaconic acid, citraconic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid,
Examples thereof include dicarboxylic acids such as sebacic acid, acid anhydrides thereof, and derivatives thereof. Examples of trivalent or higher polybasic acids and / or acid anhydrides include trimellitic acid, trimellitic anhydride, pyromellitic acid, and pyromellitic anhydride. Further, as the lower alkyl ester thereof, an alkyl residue preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Such a lower alkyl ester can be obtained by subjecting the above-mentioned polybasic acid having a valence of 2 or more or an acid anhydride thereof to a lower alcohol in an esterification reaction. Among the above polybasic acids, terephthalic acid, isophthalic acid, orthophthalic acid,
Naphthalenedicarboxylic acid, maleic acid, maleic anhydride, fumaric acid and the like are particularly preferable.

The following compounds may be mentioned as polyhydric alcohols having two or more valences. For example, as the divalent aliphatic alcohol, (a) ethylene glycol, polyethylene glycol,
Propylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol,
Examples include neopentyl glycol, cyclohexanedimethanol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, and the like.

As the divalent aromatic diol,
The following compound (b) which is an alkylene oxide adduct of bisphenol A may be mentioned. (B) Polyoxyethylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene- (2.0)-
2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2
-Bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene-
(2.4) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene- (3.3) -2,2
-Bis (4-hydroxyphenyl) propane and derivatives thereof and the like.

Further, as the trihydric or higher polyhydric alcohol, (c) sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol,
1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3 ，
Trihydric or higher alcohol such as 5-trimethylolbenzene, or ethylene glycol diglycidyl ether, hydroquinone diglycidyl ether, N, N-diglycidyl aniline, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether,
Trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, neopentyl glycol diglycidyl ether, bisphenol A
Type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, polymer or copolymer of vinyl compound having epoxy group, epoxidized resorcinol-acetone condensate, partially epoxidized polybutadiene,
There are semi-dry or dry fatty acid ester epoxy compounds and the like.

As the polyester resin used in the present invention, a polybasic acid compound selected from a divalent polybasic acid and / or an acid anhydride and / or a lower alkyl ester thereof and a divalent aliphatic polyhydric alcohol are used. As the main constituent, further, if necessary, a polybasic acid compound having a valence of 3 or more, or a polyester resin crosslinked or branched with a polyhydric alcohol having a valence of 3 or more described in the component (c) is used. Is more preferable. In that case, when the compound (b) is used as the polyhydric alcohol, it is preferably 0 to 30 mol% in all alcohol components,
It is more preferably from 0 to 10 mol%. Above all, it is particularly preferable not to use the compound (b) at all.

The polyester resin used in the present invention can be obtained, for example, by carrying out a dehydration condensation reaction or a transesterification reaction using the above raw material components in the presence of a catalyst. The reaction temperature and reaction time at this time are not particularly limited, but usually 2 to 24 at 150 to 300 ° C.
It's time. As the catalyst for carrying out the above reaction, for example, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate or the like can be appropriately used. The mixing ratio (molar ratio) of the polybasic acid compound and the diol component is 8
/ 10 to 10/8, particularly preferably 9/10 to 10/9. A linear polyester resin can be obtained by reacting a divalent polybasic acid compound with a diol component. Further, when a divalent or trivalent or more polybasic acid compound is reacted with a polyhydric alcohol or the like, a branched or network polyester resin is obtained. The polyester resin thus obtained may be used alone, or a plurality of polyester resins may be blended and used so as to obtain desired performance.

When a polyester resin is used as the binder resin of the toner for developing an electrostatic image of the present invention, the most preferable embodiment is that the compound (b) is not used as the polyhydric alcohol component and the divalent polybasic acid and And / or a linear polyester resin obtained by reacting a polybasic acid compound selected from an acid anhydride and / or a lower alkyl ester thereof with a divalent aliphatic alcohol, and a (b) compound as a polyhydric alcohol component. A polybasic acid compound selected from a divalent polybasic acid and / or an acid anhydride and / or a lower alkyl ester thereof, which is not used, and a crosslinked polyester resin obtained by reacting a divalent aliphatic alcohol and an epoxy resin. This is the case when they are used together. A toner using such a resin as a binder resin has good fixing performance at low temperatures and excellent offset performance at high temperatures.

An epoxy resin can also be preferably used as the binder resin used in the present invention. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin. is there. Above all, it is preferable to use a bisphenol A type epoxy resin or a cresol novolac type epoxy resin, and it is particularly preferable to use a bisphenol A type epoxy resin. Specifically, examples of the bisphenol A type epoxy resin include "Epiclon 2055" (softening point 80 to 90 ° C) and "Epiclon 3050" (softening point 94 to 102 ° C) manufactured by Dainippon Ink and Chemicals, Inc. , "Epiclone 4050" (softening point 96 to 104 ° C), "Epiclon 7050" (softening point 122 to 131 ° C), "Epicoat 1002" (softening point 83 ° C) manufactured by Yuka Shell Epoxy Co., Ltd., "Epicoat 1003""(Softening point 89 ° C),
"Epicoat 1004" (softening point 98 ° C), "Epicoat 1007" (softening point 128 ° C), "Epicoat 100
9 ”(softening point 148 ° C.) and the like. Examples of the cresol novolac type epoxy resin include “Epiclon N-69 manufactured by Dainippon Ink and Chemicals, Inc.
0 "(softening point 85 to 95 ° C)," Epiclon N-69
5 "(softening point 90 to 100 ° C) and the like.

As the vinyl-based copolymer resin which can be preferably used in the present invention, a styrene- (meth) acrylic acid ester copolymer resin is preferable. Styrene
The (meth) acrylic acid ester copolymer resin can be obtained, for example, by copolymerizing the following monomers.

(D) Styrene and its derivatives; for example, styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene,
Alkyl styrenes such as hexyl styrene, heptyl styrene and octyl styrene, halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene and iodostyrene, and nitrostyrene, acetylstyrene, methoxystyrene and the like.

(E) (meth) acrylic acid ester monomer; for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl. (Meth) acrylate, tertiary butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) acrylate such as stearyl (meth) acrylate, cyclohexyl (meth) Alicyclic (meth) acrylates such as acrylates, aromatic (meth) acrylates such as benzyl (meth) acrylate, hydroxyl group-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, (meth) acrylates Phosphoric acid group-containing (meth) acrylate such as roxyethyl phosphate, 2-chloroethyl (meth) acrylate, 2-hydroxy-3-chloropropyl (meth) acrylate, halogen atom-containing (meth) acrylate such as 2,3-dibromopropyl (meth) acrylate ( (Meth) acrylate, epoxy group-containing (meth) acrylate such as glycidyl (meth) acrylate, ether group-containing (meth) acrylate such as 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate,
Examples thereof include a basic nitrogen atom- or amide group-containing (meth) acrylate such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate.

(F) Further, an unsaturated compound copolymerizable therewith can also be used if necessary. For example, addition-polymerizable unsaturated aliphatic monocarboxylic acid such as (meth) acrylic acid, α-ethyl acrylic acid, crotonic acid, α-methyl crotonic acid, α-ethyl crotonic acid, isocrotonic acid, tiglic acid, and ungeric acid, Alternatively, addition-polymerizable unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid and dihydromuconic acid may be mentioned.

(G) Further examples of other copolymerizable unsaturated compounds include sulfo group-containing vinyl monomers such as sulfoethyl acrylamide, nitrile group-containing vinyl monomers such as (meth) acrylonitrile, vinyl methyl ketone and vinyl isopropenyl ketone. Such as vinyl monomer containing ketone group, N-vinylimidazole, 1-vinylpyrrole, 2-vinylquinoline, 4-vinylpyridine, N-vinyl2-
A basic nitrogen atom-containing or amide group-containing vinyl monomer such as pyrrolidone or N-vinylpiperidone can be used.

(H) Further, a crosslinking agent may be used together with the above vinyl monomer. Examples of the cross-linking agent include divinylbenzene, divinylnaphthalene, divinyl ether, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1, 3-butylene glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth)
Examples thereof include acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and tetramethylolmethane tetra (meth) acrylate.

As a method for producing a styrene- (meth) acrylic acid ester copolymer, an ordinary polymerization method can be employed, such as solution polymerization, suspension polymerization, bulk polymerization and the like in the presence of a polymerization catalyst. A method of carrying out the reaction can be mentioned.

Examples of the polymerization catalyst include 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-
Carbonitrile), benzoyl peroxide, dibutyl peroxide, butyl peroxybenzoate and the like, and the amount thereof is 0.1 to 10.
0% by weight is preferred.

A resin (ionomer) obtained by crosslinking a styrene- (meth) acrylic acid ester copolymer containing a carboxyl group-containing vinyl monomer as an essential component with a metal salt can also be used.

Further, in the present invention, a styrene-conjugated diene copolymer can be preferably used. The styrene-conjugated diene copolymer can be obtained by a known and commonly used method, but can be easily obtained by an in-situ method such as batch charging or multi-step charging of monomers, for example, emulsion polymerization.

Examples of the monomer used in the styrene-conjugated diene copolymer include styrene and its derivatives exemplified in (d) above, and examples of the conjugated diene include butadiene and isoprene. Of the conjugated dienes, butadiene is preferred.

The styrene-conjugated diene-based copolymer may be a multi-component copolymer with other copolymerizable monomers as long as the properties of the copolymer of styrene and the conjugated diene are not impaired. . Examples of such a copolymerizable monomer include vinyl chloride, vinyl acetate, and (e) to
The monomers exemplified in (h) are included.

The weight average molecular weight (Mw) of the copolymer of styrene and the conjugated diene is preferably 40,000 to 200,000. When it is less than 40,000, it is difficult to obtain sufficient strength of the toner layer in the image area, and the anti-offset performance (effect of preventing toner from adhering to the heat roll) is extremely likely to deteriorate. On the other hand, when it exceeds 200,000, the fixing temperature is increased due to the increase in the softening point, and the fixing performance is apt to be largely deteriorated under general fixing conditions.

The ratio of the monomer components constituting the styrene-butadiene copolymer is preferably 5 to 20% by weight as the ratio of the butadiene monomer. If it is less than 5% by weight, the rubber elasticity is not always sufficient. Also,
If it is 20% by weight or more, the heat resistance tends to deteriorate, and it tends to cause troubles in general toner use environment and storage environment.

The softening point of the binder resin used in the present invention is preferably in the range of 90 to 180 ° C., and 95
More preferably, it is in the range of ˜160 ° C. If the temperature is lower than 90 ° C, offsetting at high temperature tends to occur,
If it exceeds 0 ° C, the fixability at low temperatures tends to deteriorate.

The softening point of the resin in the present invention is defined as the T1 / 2 temperature measured using a flow load tester CFT-500 manufactured by Shimadzu Corporation, which is a constant load extrusion type capillary rheometer. The cross-sectional area of the piston is 1 cm when measured with a flow tester.
² , cylinder pressure 0.98MPa, die hole diameter 1mm, die length 1mm, measurement start temperature 50 ° C, temperature rising rate 6 ° C / m
in, the sample weight was 1.5 g.

Further, the glass transition temperature of the binder resin is preferably 50 ° C. or higher, and particularly preferably 55 ° C. or higher. If the Tg is 50 ° C. or less, the blocking phenomenon (thermal aggregation) is likely to occur when the toner is stored, transported, or exposed to a high temperature in the developing device of the machine. The glass transition temperature referred to here is JIS K7121.
It is defined as the extrapolated glass transition onset temperature obtained by the measurement according to. Shimadzu DSC-60 was used for the measurement.

The acid value is preferably 1 to 30 mgKOH / g, more preferably 1 to 20 mgKOH / g. The hydroxyl value is 10 to 100 mg KO.
H / g is preferred, and 10-60 mg KOH /
More preferably, it is g. When the acid value and the hydroxyl value are in the above ranges, the moisture resistance of the toner becomes good, which is preferable.

In the toner for electrostatic image development of the present invention, various known release agents such as polypropylene wax, polyethylene wax, polyamide wax, Fischer-Tropsch wax and other polyolefin waxes and / or modified polyolefins are used. wax,
Alternatively, a wax containing a higher fatty acid ester compound and / or an aliphatic alcohol compound can be appropriately used as a release agent.

Among waxes containing a higher fatty acid ester compound and / or an aliphatic alcohol compound, as waxes derived from natural products such as carnauba wax, rice wax, scale wax, montan ester wax and synthetic ester wax, As the tetrabehenate ester of pentaerythritol and the alcohol wax, a higher alcohol wax obtained by oxidizing Fischer-Tropsch wax or the like is particularly preferable.

The release agent is preferably selected according to the binder resin used in combination. When a release agent having poor dispersibility in the binder resin is selected, the release agent is more likely to be exposed on the surface of the toner particles, and the fluidity of the toner is likely to decrease. Further, in the pulverizing step in the toner manufacturing process, the release agent is easily released, the amount of the release agent contained in the toner is reduced, and the fixing / offset performance is easily deteriorated. Furthermore, in the process of developing the toner, the released release agent easily causes scumming and scattering,
The image quality is likely to deteriorate. If the dispersion in the binder resin proceeds excessively or if the release agent is compatible with the resin, the fixing / offset performance tends to deteriorate. For these reasons, it is preferable to select a release agent that is appropriately dispersed in the binder resin, and the particle size of the release agent dispersed in the binder resin is preferably in the range of 0.01 to 5 μm,
The range of 1 to 3 μm is more preferable.

A preferable combination of the binder resin and the release agent used in the present invention is a wax containing a higher fatty acid ester compound and / or an aliphatic alcohol compound when a polyester resin or an epoxy resin is used. When a vinyl-based copolymer is used, the combination is a combination of a polyolefin wax and / or a modified polyolefin wax.

The melting point (dropping point, softening temperature) of the release agent is 60.
The temperature is preferably 180 ° C to 180 ° C, more preferably 65 to 170 ° C. If the melting point is too low, the particles tend to aggregate during storage and the toner fluidity tends to decrease. If the melting point is too high, it is difficult to melt in the image fixing step, and it is difficult to exert a sufficient releasing effect.

Further, the releasing agent may adhere to a charging member such as a blade or a carrier, which may cause instability in charging performance and deterioration of image quality. The higher the better, the penetrability at 25 ° C is preferably 5 or less, more preferably 2 or less.

Natural wax, synthetic ester wax, and alcohol wax have an acid value of about 2 to 40 in catalog value due to the structure or free acid, but these values are different for the same reason as in the case of resin. The lower the better.

The release agents may be used alone or in combination, and by containing 0.1 to 15 parts by weight, preferably 1 to 5 parts by weight, based on the binder resin, good fixing offset performance can be obtained. can get. If the amount is less than 0.1 parts by weight, the offset resistance tends to be impaired, and if the amount is more than 15 parts by weight, the fluidity of the toner tends to deteriorate, and the sticking to the charging member tends to adversely affect the charging characteristics of the toner. .

The electrostatic image developing toner of the present invention may contain additives other than a binder resin, a release agent, a charge control agent and a colorant. For example, as a lubricant such as metal soap and zinc stearate, and as an abrasive, for example, cerium oxide and silicon carbide can be used.

The toner for developing an electrostatic charge image of the present invention can be obtained by a very general production method without depending on a specific production method. For example, the resin, the colorant, and the charge control agent can be obtained by melt-kneading at a melting point (softening point) or higher of the resin, pulverizing and classifying. Specifically, for example, the components such as the resin, the colorant, the release agent, and the charge control agent are uniformly mixed in advance with a Henschel mixer or the like before melt-kneading. The conditions for this mixing are not particularly limited, but they may be mixed in several stages. The colorant and the charge control agent used here may be pre-flushed so as to be uniformly dispersed in the resin, or a masterbatch melt-kneaded with the resin at a high concentration may be used.

The above mixture is mixed by a kneading means such as a two-roll, three-roll, pressure kneader, or twin-screw extruder. At this time, the colorant and the like may be uniformly dispersed in the resin, and the conditions of the melt-kneading are not particularly limited, but usually 80 to 180 ° C. and 30 seconds to 2 hours are preferable.

Further, if necessary, coarse pulverization is carried out for the purpose of reducing the load in the fine pulverization process and improving the pulverization efficiency. The apparatus and conditions used for coarse pulverization are not particularly limited, but it is common to coarsely pulverize to a particle size of 3 mm mesh pass or less by a rotoplex, palpelizer or the like.

Next, a method of finely pulverizing with an air pulverizer such as a mechanical pulverizer such as a turbo mill and a kryptron, a spiral jet mill, a counter jet mill, a collision plate jet mill and the like, and classifying with a wind classifier or the like is used. Can be mentioned. Equipment for fine pulverization and classification, conditions are desired particle size,
The particle size distribution and particle shape may be selected and set.

The volume average particle size of the particles constituting the toner is
Although not particularly limited, it is preferably adjusted to usually 5 to 15 μm.

In the present invention, various additives (referred to as external additives) can be used for surface modification of the toner such as improvement of fluidity of toner and improvement of charging characteristics. Examples of the external additive that can be used in the present invention include inorganic fine powders such as silicon dioxide, titanium oxide and alumina, and those obtained by surface-treating them with a hydrophobizing agent such as silicone oil, resin fine powders and the like. .

Among them, as the external additive suitably used for the positively charged toner, hydrophobic silica obtained by surface-treating silicon dioxide with various polyorganosiloxanes, silane coupling agents and the like can be mentioned. Specifically, there are products marketed under the following trade names. AEROSIL; RA200HS, RA200H [Japan Aerosil Co., Ltd.] WACKER; H2050, HVK2150, HDK
H30TA, H13TA, H05TA [Wacker Chemicals Co., Ltd.], CABOSIL; TG820F [Cabot Specialty Chemicals, Inc.] and the like.

The titanium oxide may be a hydrophilic grade or a hydrophobic grade surface-treated with octylsilane or the like. For example, there are commercially available products with the following trade names. Titanium oxide T
805 [Degussa Co., Ltd.], titanium oxide P25 [Japan Aerosil Co., Ltd.], titanium oxide JMT-150ANO
[Taika Co., Ltd.] and the like. Examples of alumina include aluminum oxide C [Degussa Co., Ltd.] and the like.

The particle diameter of these external additives is preferably 1/3 or less of the diameter of the toner, and particularly preferably 1 /.
It is 10 or less. Further, these external additives may be used in combination of two or more kinds having different average particle diameters. The silica content is usually 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the toner.

When the electrostatic image developing toner of the present invention is used in a two-component developing system, the following carriers can be used. As the core agent of the carrier, iron powder, magnetite, ferrite, etc., which are used in the usual two-component development method, can be used, but among them, the true specific gravity is low, the resistance is high, the environmental stability is excellent, and it is easy to form a spherical shape so that it has fluidity. Ferrite or magnetite, which has a good value, is preferably used. The shape of the core agent may be spherical, amorphous or the like, and may be used without any particular problem. The average particle size is generally 10 to 500 μm, but 30 to 100 for printing high resolution images.
μm is preferred.

Examples of coating resins for coating these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinylcarbazole, polyvinyl ether polyvinyl ketone, vinyl chloride. / Vinyl acetate copolymer, styrene / acrylic copolymer, straight silicone resin consisting of organosiloxane bond or modified product thereof, fluororesin, (meth) acrylic resin,
Polyester, polyurethane, polycarbonate, phenol resin, amino resin, melamine resin, benzoguanamine resin, urea resin, amide resin, epoxy resin, acrylic polyol resin and the like can be used. Among these, silicone resins, fluororesins, and (meth) acrylic resins are particularly excellent in charging stability and coating strength and can be used more preferably. That is, the resin-coated carrier used in the present invention is a resin-coated magnetic carrier that uses ferrite or magnetite as a core agent and is coated with one or more resins selected from silicone resin, fluororesin, and (meth) acrylic resin. It is preferable.

[0096]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

(Colorant 1) Titanium dioxide (TiO ₂ : Ti
spinel structure composite oxide (Fe ₂ TiO ₄ ) on the surface of particles (Iron Titanium spinel)
A fine black powder formed. Physical properties Primary particle size: 0.25 μm, specific surface area: 5.1 m ² /
g, pH: 6.6, oil absorption: 31 g / 100 g Water: 0.1 wt%, bulk density: 0.40 g / ml, specific resistance: 9440 Ω · cm Magnetic characteristics (VSM 397.9k)
A / m) Hc: 23.2 kA / m, σs: 9.8 Am ² / kg,
σr: 2.7 Am ² / kg True specific gravity: 5.98 Minimum reflectance in all wavelength regions of chromaticity: 2.8% (λ = 380)
nm) Maximum reflectance in all wavelength regions: 5.4% (λ = 720
nm) Difference between maximum reflectance and minimum reflectance: 2.6% L *: 19.8 a *: 1.75 b *: 1.23

(Comparative Colorant 1) 100 g of granular magnetite powder having an average diameter of 0.2 μm and a magnetization value of 85.0 emu / g was dispersed and mixed in an aqueous solution containing 0.26 mol of TiOSO ₄ . Na in the mixture
Neutralize by adding OH.
After the hydroxide of was deposited, it was filtered and dried. Furthermore, N
After heating and firing for 120 minutes at 750 ° C. under a flow of _two gases, the powder was pulverized to obtain a black particle powder (Comparative Colorant 1). The particle size of this black particle powder was 0.25 μm. Also, X
By line diffraction, the particles were found to be Fe ₂ TiO ₃ and Fe ₂ O ₃
It was confirmed to be a mixed composition with an eTiO ₃ solid solution.

The magnetic properties and true specific gravity of the comparative coloring agent 1 are as follows. Magnetic characteristics (VSM 397.9 kA / m) Hc: 9.3 kA / m, σs: 24.8 Am ² / kg,
σr: 3.5 Am ² / kg True specific gravity: 7.23

(Comparative Colorant 2) EPT-1000; Black Iron Oxide (Magnetite: Toda Kogyo Co., Ltd.) Magnetic Properties (VSM 397.9 kA / m) Hc: 9.3 kA / m, σs: 82.4 Am ² / kg ,
σr: 10.5 Am ² / kg True specific gravity: 8.88

A synthesis example of the binder resin used for preparing the toner is shown below. The resin obtained in each synthesis example was put in tetrahydrofuran (THF), left standing for 12 hours, and the solution was filtered to measure the molecular weight of the THF-soluble component. For the analysis, a gel permeation chromatography (GPC) method was used, and the molecular weight was calculated from a calibration curve prepared using standard polystyrene. GPC device: Tosoh Corp. HLC-8120 GPC column: Tosoh Corp. TSK Guardcolu
mn SuperH-H TSK-GEL Super
HM-M3 coupling concentration: 0.5 wt% Flow rate: 1.0 ml / min The THF insoluble content is 1 g of the sample powder placed on a cylindrical filter paper, and the residue on the filter paper after refluxing for 8 hours with THF as a solvent in a Soxhlet extractor Calculated from Acid value is JIS K690
1 and Tg were measured according to JIS K7121.

(Resin 1) -Terephthalic acid: 664 parts by weight-Ethylene glycol: 75 parts by weight-Polyoxypropylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane: 700 parts by weight-Tri Methylol propane: 80 parts by weight Tetrabutyl titanate: 3 parts by weight The above materials were placed in a four-necked flask equipped with a stirrer, a condenser and a thermometer, and 4 parts by weight of tetrabutyl titanate was added under a nitrogen gas stream. While removing water produced by dehydration condensation, the reaction was carried out at 240 ° C. for 10 hours under normal pressure. Thereafter, the pressure was sequentially reduced and the reaction was continued at 5 mmHg. The reaction was followed by the softening point, and the reaction was terminated when the softening point reached 145 ° C. The obtained polyester resin is
Mn: 5450, Mw: 152200, softening point: 147
C, acid value is 5.8, Tg by DSC measurement method is 63 ° C,
The THF insoluble content was 3%.

(Resin 2) -Terephthalic acid: 664 parts by weight-Propylene glycol: 152 parts by weight-Cyclohexanedimethanol: 145 parts by weight-Neopentyl glycol: 150 parts by weight The above materials were set with a stirrer, a condenser and a thermometer. Place in a 2-liter four-necked flask, and under a nitrogen gas stream, 4
While adding tetrabutyl titanate in parts by weight and removing water generated by dehydration condensation, the reaction was carried out at 200 ° C. for 20 hours under normal pressure. Thereafter, the pressure was sequentially reduced and the reaction was continued at 5 mmHg. The reaction was followed by the softening point according to ASTM E28-517, and the reaction was terminated when the softening point reached 90 ° C. The molecular weight of the obtained polyester is M
It was n: 2520 and Mw: 6200. Softening point: 95
° C, acid value: 6.8, Tg in DSC measurement method: 53
It was ° C.

(Resin 3) -Terephthalic acid: 664 parts by weight-Neopentyl glycol: 120 parts by weight-Ethylene glycol: 150 parts by weight-Propylene glycol: 61 parts by weight-Epiclon 830 (Dainippon Ink and Chemicals, bisphenol F type) Epoxy resin): 19.3 parts by weight, Cardura E: 20 parts by weight The above materials were placed in a 2 liter four-necked flask equipped with a stirrer, a condenser and a thermometer and placed under a nitrogen gas stream for 4 days.
g of tetrabutyl titanate was added, and the reaction was carried out at 240 ° C. for 12 hours under normal pressure while removing water produced by dehydration condensation. After that, the pressure was sequentially reduced and the reaction was continued at 30 mmHg. The reaction was followed by the softening point according to ASTM E28-517, and the reaction was terminated when the softening point reached 200 ° C. The obtained polyester resin has Mn: 5
2,800, Mw: 165,100, THF insoluble matter 7.
4%, softening point: 203 ° C, acid value: 9.3, Tg: 6
It was 7.2 ° C.

(Resin 4) -isophthalic acid: 116 parts by weight-terephthalic acid: 166 parts by weight-trimellitic anhydride: 38 parts by weight-diethylene glycol: 26 parts by weight-neopentyl glycol: 104 parts by weight-ethylene glycol: 50 parts by weight Parts-Tetrabutyl titanate: 2.5 parts by weight or more of the raw materials were placed in a glass 2-liter four-necked flask, equipped with a thermometer, a stirring rod and a nitrogen introducing tube, and in an electric heating mantle heater under a normal pressure nitrogen stream. After reacting at 240 ° C. for 10 hours, the pressure was sequentially reduced and the reaction was continued at 10 mmHg. The reaction was followed by the softening point according to ASTM E28-517, and the reaction was terminated when the softening point reached 148 ° C. The obtained polyester resin is a colorless solid and has an acid value:
4, Tg: 72 ° C, softening point: 151 ° C.

(Resin 5) -Styrene: 380 parts by weight-Butylmethacrylate: 120 parts by weight-Divinylbenzene: 10 parts by weight-Benzoyl peroxide: 5 parts by weight Thermometer, glass air flow introducing tube, vacuum-proof sealing device A 2-volume four-necked round bottom flask equipped with a stirring rod and a water-cooled Dimroth condenser was charged with 500 parts of xylene, the above-mentioned monomers and all of the initiators. Nitrogen gas was introduced from a glass air flow introduction tube to replace the inside of the reactor with an inert atmosphere, and then the contents were gradually heated by a mantle heater with a slider box to raise the temperature to 75 ° C. The reaction is 65
The temperature was raised to 130 ° C to complete the polymerization after 10 to 12 hours, while the temperature was kept at 80 ° C to 80 ° C. Next, the water-cooled condenser and the glass air flow introducing tube were removed from the flask, and instead, a capillary for vacuum distillation and a Claisen fractionating tube were attached. A thermometer and a water-cooled Leibitz condenser were connected to the Claisen distillation tube, and the outlet of the condenser was connected to an eggplant-shaped flask via a suction adapter. The vacuum adapter was connected to the vacuum adapter via a manometer and a trap with a rubber tube for pressure reduction, and preparation for vacuum distillation was completed. When the mantle heater is heated and the contents are sufficiently stirred and the vacuum pump is operated to reduce the pressure to 20 mmHg, the liquid temperature is 75 ° C and the distilling temperature is 38.
At x ° C, xylene or possibly unreacted monomer began to distill. Finally, the solvent was completely removed by reducing the pressure to 0.5 mmHg at a liquid temperature of 180 ° C. The obtained polymer (hereinafter referred to as polymer (a)) was placed in a stainless steel pan in a molten state at high temperature, cooled to room temperature and then crushed. The resulting polymer had a softening point of 145 ° C., Tg: 61 ° C., Mn: 8,000,
It was Mw: 21,000.

(Example 1) <Manufacture of Toner> -Resin 1 43 parts by weight-Resin 2 43 parts by weight-Colorant 18 parts by weight N-04; Bontron N-04 2 parts by weight (Nigrosine dye manufactured by Orient Chemical Co., Ltd.) ) Compound (2-1) 1 part by weight Purified carnauba wax No. 1 powder (manufactured by Hiroyuki Kato) 3 parts by weight A mixture of the above raw materials was prepared using a Henschel mixer, and the mixture was temporarily stored in a hopper. Then, the mixture was kneaded with a biaxial melt kneader. The kneaded material thus obtained was pulverized by a mechanical pulverizer and then classified to obtain a toner base material 1 having a volume average particle diameter of 10.0 μm. Toner stock 1 100 parts by weight HVK2150 0.5 part by weight Obtained toner base 1 and the above hydrophobic silica are mixed by a Henschel mixer, and then sieved to obtain Example 1.
Toner was obtained.

Thereafter, toners of Examples 2 to 4 and Comparative Examples 1 to 5 were produced with the formulations shown in Table 1 in the same manner as in Example 1.

[0109]

[Table 1] ・ Mogal L; Carbon black (manufactured by Cabot) ・ Carnava; Carnauba wax No. 1 powder (manufactured by Yoko Kato) ・ 550P; Viscor 550P (manufactured by Sanyo Kasei Co., Ltd., polypropylene wax) ・ N-04; Bontron N-04 (manufactured by Orient Chemical Co., Ltd.,
Nigrosine dye) PR; COPY BLUE PR (manufactured by Clariant,
Triphenylmethane dye)

<Toner Test of Each Example and Comparative Example> Using the silicone-coated ferrite carrier (particle size 100 μm) and the toner of Examples and Comparative Examples, a developer was prepared so that the toner concentration would be 5% by weight. The following tests were performed using each developer.

(Measurement of Transfer Efficiency) A commercially available copying machine was used to develop a solid image (100 mm long × 20 mm wide),
It was stopped when the solid image on the photoreceptor passed 50% through the transfer portion. After that, the untransferred image (solid) on the photoreceptor
Each unfixed image after transfer is taped (30 mm × 20
mm), the toner amount of the untransferred image and the toner amount after the transfer are measured, and the transfer efficiency (%) is calculated from the following formula.
Was calculated. The results are shown in Table 2. Transfer efficiency (%) = {1- (toner amount after transfer / toner amount of untransferred image)} × 100

(Comparison of rising of charge) The developer 50
115 RP for 100 cc polyethylene container containing g
After stirring for 3 minutes with a ball mill of m, the developer was sampled and the charge amount was measured with a blow-off charge amount measuring device. After further stirring for 7 minutes (total 10 minutes), the charge amount was measured in the same manner. The test results are shown in Table 2.

(Fixing Performance Test) Regarding the fixing temperature range, the fixing temperature was obtained by the following test, and the range between the upper limit value and the lower limit value was defined as the fixing temperature range. A test sample in which a belt-shaped unfixed image was formed on a paper was prepared with a printer using a commercially available organic optical semiconductor as a photoconductor, using the toners of Examples and Comparative Examples. Using a heat roll (oilless type) of RICOH IMAGIO DA-250, fixing was performed while changing the surface temperature at a fixing speed of 90 mm / sec. Mending tape (3
The temperature range of the heat roll, in which the image density (ID) after peeling and peeling was applied to 90% or more of the original ID and no offset was observed, was defined as the fixing temperature range. The results are shown in Table 2.

[0114]

[Table 2]

(Printing durability test) A commercial high-speed printer (220 sheets of A4 paper / minute) was used to continuously print 100,000 sheets, and the density of the image area and the background stain density were measured and the charge amount of the developer was measured. Was measured. The image density and background stain were measured with a Macbeth densitometer RD-918. The background stain was obtained by subtracting the white paper density before printing from the white background density of the print density. ○, 0.0 when the difference is less than 0.01
When it was 1 to less than 0.03, it was evaluated as Δ, and when it was 0.03 or more, it was evaluated as x. The test was conducted in an environment of 25 ° C. and 60%.
The results are shown in Table 3.

Further, the state of toner scattering inside the developing machine was visually observed. ○: No scattering was observed, almost no scattering was observed, but toner contamination was observed when the inside of the device was wiped with a waste cloth, ×: In-machine scattering was visually confirmed, and severe scattering inside the machine was confirmed. The possible state is XX. The results are shown in Table 3.

The charge amount was measured with a blow-off charge amount measuring device (manufactured by Toshiba Chemical Co.) by collecting the toner from the developing device. The results are shown in Table 3.

(Change in Image Density: ΔID) The change in image density at the initial stage and after printing 100,000 sheets in the above print durability test was determined. The fluctuation in image density (ΔID) was obtained by subtracting the initial image density from the image density after printing 100,000 sheets. The calculation results are shown in Table 3.

[0119]

[Table 3]

[0120]

EFFECT OF THE INVENTION The toner for developing an electrostatic charge image of the present invention, which uses black fine particles in which the surface of titanium oxide particles is coated with a layer containing a composite oxide of titanium and iron as a colorant, can be used for a long period of time or in many cases. Stable charging behavior is exhibited even when printing a set number of copies, and printing can be performed without toner scattering or scumming and without fluctuation in image density.

Claims (7)

[Claims] 1. A toner for developing an electrostatic charge image comprising a binder resin, a colorant and a charge control agent, wherein the colorant is black fine particles in which the surface of titanium dioxide particles is coated with a complex oxide of titanium and iron. The electrostatic charge image, wherein the charge control agent contains at least one compound selected from a nigrosine dye, a modified nigrosine dye, and a triphenylmethane dye and a compound having a quaternary ammonium salt structure. Toner for development. 2. The composite oxide of titanium and iron is Fe ₂ T.
The toner for developing an electrostatic charge image according to claim 1, which is iO ₄ . 3. The compound having a quaternary ammonium salt structure is represented by the formula 1, (Formula 1) [In formula, R < ₁ >, R < ₂ > and R < ₃ > respectively independently represent a C1-C10 alkyl group. ] The toner for developing an electrostatic charge image according to claim 1, which is a compound represented by the formula [1]. 4. The compound having a quaternary ammonium salt structure is represented by the formula 2, (Equation 2) _wherein, R _1, R 2, _{R 3} and _{R 4} are, each independently, a hydrogen atom, an alkyl group or alkenyl group having 1 to 22 carbon atoms, unsubstituted or having 1 to 20 carbon atoms It represents a substituted aromatic group or an aralkyl group having 7 to 20 carbon atoms, and A ⁻ represents a molybdate anion or a tungstate anion, or a heteropolyacid anion containing a molybdenum or a tungsten atom. ] It is a compound represented by these.
Or the toner for developing an electrostatic charge image as described in 2 above. 5. The compound having a quaternary ammonium salt structure is represented by the formula 3, (Formula 3) (In the formula, m is an integer of 1 to 3, n is an integer of 0 to 2, X and Z are 1 or 2, Y is 0 or 1, and when X = 1, Y =
1, Z = 1, X = 2, Y = 0, Z = 2, M represents a hydrogen atom or a monovalent metal ion, R ₁ ,
R ₂ , R ₃ , and R ₄ are hydrogen atoms, a linear or branched saturated or unsaturated alkyl group having 1 to 30 carbon atoms, a compound of the formula [(-CH ₂ CH ₂ O) _p -R (where R is A hydrogen atom or an alkyl group having 1 to 4 carbon atoms or an acyl group, and p is an integer of 1 to 10)],
Represents a monocyclic or polycyclic aliphatic group having 5 to 12 carbon atoms, or a monocyclic or polycyclic aromatic group, wherein R _{5 to} R ₁₂ represent a hydrogen atom, a linear or branched group having 1 to 30 carbon atoms saturated or unsaturated alkyl group, an alkoxyl group having 1 to 4 carbon atoms or an expression _{[(-C q H 2q -O)} r -R, ( provided that
R is a hydrogen atom or an alkyl group or an acyl group having 1 to 4 carbon atoms, q is an integer of 2 to 5, and r is an integer of 1 to 10)]. } The toner for developing an electrostatic charge image according to claim 1, which is a compound represented by the formula: 6. The toner for developing an electrostatic charge image according to claim 1, wherein the binder resin is a polyester resin. 7. The method according to claim 1, further comprising a higher fatty acid ester compound or an aliphatic alcohol compound as a release agent.
7. The toner for developing an electrostatic charge image according to any one of 2, 3, 4, 5 and 6.