JP3049865B2 - Magnetic particle powder for magnetic toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic particle powder for a magnetic toner having high water repellency, excellent environmental stability, and excellent dispersibility with a binder resin.

[0002]

2. Description of the Related Art In recent years, electrostatic copying machines have been remarkably spread, and accordingly, research and development of magnetic toners as developers have been actively carried out, and improvements in their characteristics have been demanded.

[0003] A magnetic toner is generally produced by dispersing magnetic iron oxide particles having an isotropic shape in a synthetic resin. In other words, for example, the magnetic iron oxide particles have a weight of 20 to 60% by weight. Parts, 40 to 80 parts by weight of a styrene-acrylic copolymer-based synthetic resin, 0.5 to 2 parts by weight of a charge control agent such as carbon black and 2 to 5 parts by weight of a low molecular weight polypropylene, and after cooling, pulverizing and sieving. In order to improve the properties, it is necessary that the magnetic iron oxide particles, which are the material powders, have excellent dispersibility, which is described in, for example, Japanese Patent Publication No. 53-21656. "Equivalent magnetism required for visualizing an electrostatic latent image is obtained by uniformly dispersing iron oxide throughout the developer particles".

[0004] On the other hand, the magnetic particle powder has a hygroscopic property and has a problem in environmental stability.
Japanese Patent Application Laid-Open No. 1-278860 states that “A magnetic substance used in a normal toner has a strong affinity for water, and when used in a toner,
As a result of non-uniform dispersion in the binder resin, development characteristics and transfer characteristics deteriorate due to the effect of moisture absorption in a high-humidity environment, which often renders them unusable in practice. ".

Various attempts have been made to improve the dispersibility of magnetic particle powders, and a method of modifying the particle surface by coating the particle surface with a silane coupling agent or a titanate coupling agent is well known. I have.

A method of coating magnetic particle powder with an organoaluminum compound is also known.
JP-A-8-207052, JP-A-1-259369, JP-A-1-259372, JP-A-57-60
535, JP-A-57-135438, JP-A-57-198606, and JP-A-63-52326.
JP, JP-A-63-306526, JP-A-1-
No. 230702, JP-A-60-139759 and JP-A-62-208608.

[0007]

The magnetic particles having excellent dispersibility are the most demanded at present. However, according to the above-mentioned known techniques, it is said that the particles are still excellent in dispersibility. It is difficult.

[0008] The reason that particles having excellent dispersibility have not yet been obtained by the above-mentioned known techniques is, for example, "magnetic paint from the viewpoint of a magnetic recording material researcher" (powder powder metallurgy, "7th Ferrite"). Summer Seminar Lecture Summary "
(1977, pp. 14-16), p. 16 "In general, obtaining a high degree of dispersion is a very difficult problem even with ordinary non-magnetic pigments. The magnetic particle powder forms an aggregate by the interaction due to magnetism, so that the surface is coated with the aggregate as it is. Is caused by that. In particular, in the case of hexagonal ferrite particles having an easy axis of magnetization in the direction perpendicular to the plate surface, the particles mutually agglomerate strongly due to the interaction by magnetism, and the agglomerated particles are separated into individual particles only by mechanical treatment alone. Is difficult to separate.

In the case where the magnetic particles are coated with a coupling agent, for example, Japanese Patent Application Laid-Open No. 62-76508 discloses that "the coupling agent is apparently uniformly coated on the surface of the magnetic powder, When analyzing in detail, there are a part where the coupling agent is strongly bonded by chemical force and a part where the coupling agent is weakly adhered by physical force, and these parts are bonded by this physical weak force It was confirmed that the portion bleeded to the surface of the recording medium and the running property and durability of the recording medium were impaired. "

[0010] Therefore, the present invention provides a magnetic particle having a more excellent dispersibility by coating with a surface modifier which firmly binds to the particle surface of the magnetic particle powder and further improves the dispersibility in the binder resin. It is a technical problem to obtain a particle powder.

[0011]

The present inventors have conducted intensive studies with the aim of solving the above-mentioned technical problems, and as a result, have found that such problems can be achieved by the present invention as described below.

That is, the present invention relates to magnetic particle powder comprising magnetic particles whose surface is coated with a fluorocarbon chain-containing aluminum compound represented by the following general formula (1), (2) or (3). .

[0013]

Embedded image However, in the above general formulas (1), (2) and (3), n, m, L and b represent 1 or 2 (provided that n + L ≦ 3), and X and V each independently represent Represents the following bond (4) or —O—, and Y and W are each independently —C _K H
_{2K -, - (C K H} 2K O) G - or a single covalent bond is shown - a represents (where, K is an integer of 1 to 30, and G is 1
R ¹ and R ² each independently represent an alkyl group having 1 to 30 carbon atoms, and R ^f is C _q F
_{2q + 1} or an _C q _{F 2q} H, A and B each _{independently} represent a C _{p F 2p + 1} or Cj H _{2j + 1} O (where, p, q, j are each independently an integer of 1 to 30 And Z represents VR ² or VWR ^f .

[0014]

Embedded image

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

The magnetic particles according to the present invention include magnetic iron oxide particles such as maghemite particles, magnetite particles, and beltlide compound particles which are intermediate oxides between maghemite and magnetite;
o, particles of magnetic iron oxide containing dissimilar metals such as Ni, Cu, Mg, Zn, Ba, Sr, and Pb, or particles obtained by coating Co on these magnetic iron oxide particles; Metallic magnetic particles; Mn, Co, Ni, Cu, M
g, spinel-type ferrite particles containing a metal such as Zn,
Any of ferrite particles such as magnetoplumbite type ferrite particles containing a metal such as Ba, Sr, and Pb can be used. The shape of the magnetic particles is acicular, cubic,
An octahedral shape, a spherical shape, a plate shape and the like may be appropriately selected, and a specific surface area is preferably about 1 to 30 m ² / g.

The aluminum compound having a fluorocarbon chain, which is one of the features of the present invention, includes isopropoxy nonadecafluorodecanoyl aluminum ethyl acetoacetate, isopropoxy nonadecafluorodecanoyl aluminum octadecyl acetoacetate, and isoproxy nonadeca Fluorodecanoylaluminum acetylacetonate, isopropoxy 1H, 1H, 2H, 2H-perfluorodecanoxyaluminum ethyl acetoacetate, isopropoxy 1H, 1H, 2H, 2H-perfluorodecanoxyaluminum octadecyl acetoacetate, isopropoxy 1H, 1H, 2H, 2H-perfluorodecanooxyaluminum acetylacetonate, diisopropoxyaluminum 1H, 1H, 2H,
2H-perfluorodecyl acetoacetate, isopropoxydi-1H, 1H, 2H, 2H-perfluorodecaloxy aluminum and the like can be mentioned.

Fluorocarbon chain-containing aluminum compounds
Thus, the amount to be added to the magnetic particle powder to coat the magnetic particle surface is 0.05 to 2 parts by weight based on 100 parts by weight of the magnetic particle powder in consideration of the specific surface area of the magnetic particle powder.
0 parts by weight, preferably 0.1 to 6 parts by weight. 0.
If the amount is less than 05 parts by weight, the effect of the present invention cannot be obtained because the coating on the surface of the magnetic particles is insufficient. If the amount exceeds 20 parts by weight, the magnetization value of the magnetic particles is remarkably reduced due to an increase in components not involved in the magnetization.

Considering the water repellency and the magnetization value of the magnetic particles, it is sufficient that the amount is sufficient to form a monomolecular layer on the particle surface of the magnetic particles. Accordingly, since the area that can be covered with 1 g of the fluorocarbon-containing aluminum compound is 500 to 1000 m ² , in order to coat magnetic particle powder of 1 to 30 m ² / g in a monomolecular layer, 100 parts by weight of the magnetic particles is required. The compound may be added in an amount of 0.1 to 6 parts by weight.

The surface treatment method for coating the surface of the magnetic particles with the fluorocarbon chain-containing aluminum compound is not particularly limited, and such methods include (1) adding the fluorocarbon chain-containing aluminum compound to the magnetic particle powder. And co-milling using a mill such as a Henschel mixer, ball mill, atomizer colloid mill, which is considered to be adsorbed on the surface of the magnetic particles, and (2) magnetic solvent in the organic solvent. A method in which a fluorocarbon chain-containing aluminum compound is added together with the particle powder, and the solvent is removed after stirring and mixing. (3) A fluorocarbon chain-containing aluminum compound is added to a mixture of the organic solvent and the magnetic particle powder, and a hot roll or the like is added. And the like.

[0021]

The most important point in the present invention is the fact that the magnetic particles according to the present invention have a very large contact angle and high water repellency.

When a conventional aluminum-based coupling agent, for example, acetoalkoxyaluminum diisopropylate is coated, a contact angle of only about 95.9 ° can be obtained as shown in a comparative example described later. The contact angle of the magnetic particle powder according to the above is 128.
It is dramatically improved to 9 °.

The reason is that, in the aluminum compound containing a fluorocarbon chain of the present invention, the aluminum in the compound is strongly adsorbed on the surface of the magnetic particles, and the fluorocarbon in the side chain of the compound is (1) water. Greatly lowers the surface tension of
(2) exhibits high surface activity at low concentration, (3) exhibits excellent heat resistance and chemical resistance, and (4) exhibits surface activity even in organic solvents.
It is considered that excellent properties such as water repellency were remarkably brought out.

Therefore, when the particle surface of the magnetic particle powder is coated with the aluminum compound containing a fluorocarbon chain as in the present invention, the contact angle increases and the water repellency increases, so that the environmental stability is improved. Moreover, the dispersibility in the binder resin is also excellent.

Incidentally, the fluorocarbon chain-containing aluminum compound to be coated on the particle surface of the magnetic particle powder according to the present invention is a novel substance, and its production method is described in the invention "Fluorocarbon chain-containing aluminum surface modifier. Japanese Patent Application No. 2-
As described in JP-A-331299.

That is, the fluorocarbon chain-containing aluminum compounds represented by the general formulas (1), (2) and (3) are each (a) an alkoxyaluminum compound selected from the following group I, Mole of the fluorocarbon chain-containing compound represented by (13) and y-fold mole of (14)
(Where x and y are:
0.1 ≦ x ≦ 2.5 and 0 ≦ y ≦ 2.5 and x + y ≦
2.5), (b) an alkoxyaluminum compound selected from the following group I, x times the molar amount of the dicarbonyl compound represented by (11), and y times the molar amount of the fluorine compound represented by (13). Carbon chain containing compound (where x and y are
0.1 ≦ x ≦ 2.5 and 0.1 ≦ y ≦ 2.5 and 0.1
≦ x + y ≦ 2.5), and (c) an alkoxyaluminum compound selected from the following group I, x times the molar amount of the dicarbonyl compound represented by (12), and y times the moles of the above group II (13) or (14) wherein x and y are 0.1 ≦ x ≦ 2.5 and 0 ≦ y
≦ 2.5 and a number satisfying 0.1 ≦ x + y ≦ 2.5)
The reaction is carried out at room temperature or in a suitable solvent such as isopropyl alcohol, toluene or xylene at room temperature or at a temperature of 100 ° C. or less for several hours. , Wax or powdered material.
When x or y is less than 0.1, x + y> 2.
In the case of 5, the reactivity becomes poor.

[0027]

Embedded image In the above production method, examples of the aluminum compound of Group I as a raw material include trimethoxyaluminum, triethoxyaluminum, triisopropoxyaluminum, and tributoxyaluminum. From the viewpoint of reactivity and economy, triisopropoxy aluminum is used. Aluminum and tryptoxyaluminum are preferred.

Rf in the structural formula of the compound represented by the formula (12) or (13) is CF ₃ , C ₂ F ₅ , C ₃ F
_{7, C 4 F 9, C} 5 F 11, C 6 F 13, C 7 F 15,
C ₈ F ₁₇ , C ₈ F ₁₆ H, C ₉ F ₁₉ , C ₉ F
_{18 H, C 10 F 21,} C 10 F 2 0 H, C
_{11 F 23, C 11 F 22} H, C 12 F 25, C 12 F
_{24 H, C 13 F 27,} C 13 F 26 H, C
_{14 F 29, C 14 F 28} H, C 15 F 31, C 15 F
_{30 H, C 16 F 33,} C 16 F 32 H, C
_{17 F 35, C 17 F 34} H, C 18 F 37, C 18 F
₃₆ H and the like. Among them, C ₇ F ₁₅ , C ₇ F ₁₄ H, C ₈ F ₁₇ ,
C ₈ F ₁₆ H, C ₉ F ₁₉ , C ₉ F ₁₈ H, C ₁₀ F
₂₁ , C ₁₀ F ₂₀ H is preferred.

In the compound represented by the formula (13) or (14), when a spacer Y or W is present,
Such spacers include CH ₂ , C ₂ H ₄ , C
_{3 H 6, C 4 H 8} , C 5 H 10, C 6 H 12, C 7 H
₁₄ , C ₈ H ₁₆ , C ₉ H ₁₈ , C ₁₀ H _{20 and the} like, among which C ₂ H ₄ , C ₄ H ₈ , C ₆ H
₁₂ is preferred.

R ^{2 in} the structural formula of the compound represented by the formula (14) is CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H
_{9, C 5 H 11, C} 6 H 13, C 7 H 15, C
_{8 H 17, C 9 H 19} , C 10 H 21, C 11 H 23,
_{C 12 H 25, C 13 H} 27, C 14 H 29, C 15 H
₃₁ , C ₁₆ H ₃₃ , C ₁₇ H ₃₅ , C ₁₈ H ₃₇ , C
₁₉ H ₃₉ , C ₂₀ H _{41 and the} like,
Among them, C ₄ H ₉ , C
₆ H ₁₃ , C ₈ H ₁₇ , C ₁₂ H ₂₅ and C ₁₈ H ₃₇ are preferred.

The compound represented by the formula (11) includes
Examples include acetylacetone, acetoacetic ester, malonic diester, and acetoacetic anilide.
When a compound such as carboxylic acid which easily coordinates to a metal is used as a raw material, a raw material which coordinates intramolecularly, such as a dicarbonyl compound, is indispensable, since the compound is gelled by intermolecular coordination. Compounds that coordinate intramolecularly to aluminum include:
Compounds that form a 5- or 6-membered ring are preferred, and compounds that do not have extra functional groups that coordinate outside the molecule are preferred. Ethyl acetoacetate and acetylacetone are preferred in view of such conditions, properties of the product, and economic efficiency.

The following are some examples of the synthesis of the fluorocarbon chain-containing aluminum compound according to the present invention. Synthesis Example 1 Synthesis of isopropoxynonadecafluorodecanoyl aluminum ethyl acetoacetate 2.0 g of aluminum triisopropoxide (9.8 m
mol) at room temperature with stirring.
A solution of 8 g (9.8 mmol) in toluene (2 ml) was slowly added dropwise, and the mixture was stirred at 60 ° C. for 30 minutes. Then, 9.1 g (0.018 mol) of nonadecafluorodecanoic acid was gradually added. For a minute. This is further added at 60 ° C for 1
Stirred for hours.

The isopropyl alcohol and toluene were distilled off under reduced pressure to obtain a reddish brown viscous liquid. I of this one
The R spectrum showed an absorption different from the IR spectrum of the starting compound, indicating that a new product was obtained. Synthesis Example 2 Synthesis of isopropoxy nonadecafluorodecanoyl aluminum octadecyl acetoacetate Nonalumina was stirred at room temperature in a toluene (2 ml) solution of 2.0 g of an aluminum-based coupling agent “AL-M” (manufactured by Ajinomoto Co., Inc.). 2.9 g of decafluorodecanoic acid (5.
64 mmol) and stirred at 50 ° C. for 30 minutes. This was further stirred at 60 ° C. for 1 hour.

The orange and creamy substances were obtained by distilling off toluene and isopropyl alcohol. Its IR spectrum showed an absorption different from that of the starting compound, indicating that a new product was obtained. Synthesis Example 3 Synthesis of isopropoxynonadecafluorodecanoyl aluminum octadecyl acetoacetate (reaction without solvent) Nonadecafluorodecanoic acid 2.9 at room temperature while stirring with 2.0 g of aluminum-based coupling agent “AL-M”
g (5.64 mmol) was gradually added, and the mixture was stirred at 50 ° C. for 30 minutes. This was further stirred at 60 ° C. for 1 hour.

Thus, a reddish brown viscous liquid was obtained. Synthesis Example 4 Synthesis of isopropoxynonadecafluorodecanoyl aluminum acetylacetonate 2.0 g of aluminum triisopropoxide (9.8 m
mol) at room temperature with stirring.
g (9.98 mmol) in toluene (2 ml) was slowly added dropwise, and the mixture was stirred at 60 ° C. for 30 minutes. Then, 2.57 g (10.0 mmol) of nonadecafluorodecanoic acid was gradually added. For a minute. This is further added at 60 ° C for 1
Stirred for hours.

The isopropyl alcohol and toluene were distilled off under reduced pressure to obtain a reddish brown viscous liquid.

When this reaction was carried out without solvent, stirring became difficult. Synthesis Example 5 Synthesis of isopropoxy 1H, 1H, 2H, 2H-perfluorodecanoloxyaluminum ethyl acetoacetate 60 g of aluminum triisopropoxide (0.29 mol
l) of isopropyl alcohol (50 ml) at room temperature with stirring at room temperature.
mol) was slowly added dropwise, and the mixture was stirred at 60 ° C. for 2 hours.
H, 1H, 2H, 2H-perfluorodecanol 13
6.5 g (0.29 mol) was gradually added, and the mixture was reacted at a reflux temperature for 1 hour.

Thereafter, isopropyl alcohol was distilled off under reduced pressure to obtain a colorless viscous liquid. From the IR spectrum, it was found that a new product different from the starting compound was obtained. Synthesis Example 6 Synthesis of isopropoxy 1H, 1H, 2H, 2H-perfluorodecanoxyaluminum octadecyl acetoacetate 1H, 1H, 2H, 2H- while stirring at room temperature with 96 g of an aluminum-based coupling agent "AL-M". 89.3 g (0.19 mol) of perfluorodecanol was added, and 5
After stirring at 0 ° C. for 30 minutes, the mixture was further reacted at reflux temperature for 1 hour.

Thereafter, isopropyl alcohol, which was a by-product, was distilled off to obtain a yellow viscous liquid. From the IR spectrum, it was found that a new product different from the starting compound was obtained. Synthesis Example 7 Synthesis of isopropoxy 1H, 1H, 2H, 2H-perfluorodecanoxyaluminum acetylacetonate 1 g of aluminum triisopropoxide (4.9 mM
l) of isopropyl alcohol (5 ml) at room temperature with stirring at room temperature.
l) was slowly added dropwise, and the mixture was stirred at 60 ° C for 2 hours.
H, 1H, 2H, 2H-perfluorodecanol 2.2
7 g (4.9 mmol) was gradually added, and the mixture was reacted at a reflux temperature for 1 hour.

Thereafter, isopropyl alcohol was distilled off under reduced pressure to obtain a pale yellow viscous liquid. From the IR spectrum, it was found that a new product different from the starting compound was obtained. Synthesis Example 8 Diisoproxy aluminum 1H, 1H, 2
Synthesis of H, 2H-perfluorodecyl acetoacetate 1H, 1H, 2H, 2H-perfluorodecanol 3
Ethyl acetoacetate was added dropwise to a mixture of 5.7 g (76.9 mmol) and 0.2 g (0.7 mmol) of tetraisopropyl titanate at 40 to 50 ° C. with stirring, and the temperature was raised to 100 ° C. to produce ethanol as a by-product. 2 while removing
Stirred for hours.

The resulting yellow liquid was distilled under reduced pressure,
A distillate of 118 ° C. was obtained. IR, proton NM
From R and MS, it was identified as 1H, 1H, 2H, 2H-perfluorodecyl acetoacetate. 2.69 g (4.9 mmol) of this acetoacetate was added dropwise to 1 g of triisopropoxyaluminum and stirred at 120 ° C. for 2 hours while removing by-produced isopropanol to obtain a pale yellow viscous liquid.

From the IR spectrum, it was found that a new product different from the starting compound was obtained. Synthesis Example 9 Isopropoxydi 1H, 1H, 2H, 2H-
Synthesis of perfluorodecanoxyaluminum 1 g of triisopropoxyaluminum in toluene (4 m
l) 4.55 g (9.8 mmol) of 1H, 1H, 2H, 2H-perfluorodecanol was added to the solution, and the mixture was stirred at reflux for 1 hour while removing the by-produced isopropanol to give a colorless viscous liquid. I got

From the IR spectrum, it was found that a new product different from the starting compound was obtained.

In using the substance represented by the general formula (1), (2) or (3) as an inorganic surface modifier, the substance obtained by the above method is isolated from the reaction product and used. Alternatively, the reaction product obtained by simply distilling off the alcohol and / or the solvent without isolation or by using the reaction product before distilling may be used. The degree of water repellency can be changed by changing the values of the above molar ratios x and y, and it can be used in combination with a conventionally known surface modifier.

[0045]

The present invention will be further described below with reference to examples and comparative examples.

In Examples and Comparative Examples, the contact angle of the magnetic particle powder was measured by measuring 0.2 g of the sample with an IR tableting machine.
It was formed into a tablet shape under a pressurized pressure of 00 kg / cm ² for 5 minutes, and the contact angle immediately after a drop of water was added thereto was indicated by a value measured by a contact angle automatic measuring machine (manufactured by Ajinomoto Co., Inc.).

The magnetic properties of the magnetic particle powder were measured by using an "oscillating sample magnetometer VSM-3S-15" (manufactured by Toei Kogyo Co., Ltd.) by applying an external magnetic field to the magnetic particle powder up to 10 KOE. is there.

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

Example 1 2,000 g of spherical magnetite particle powder having an average particle size of 0.22 μm, a specific surface area of 7.0 m ² / g, a saturation magnetization of 86.0 emu / g and a coercive force of 55 Oe, and isopropoxynonadeca 20 g of fluorodecanoyl aluminum octadecyl acetoacetate (manufactured by Ajinomoto Co., Inc.) (corresponding to 1 part by weight with respect to 100 parts by weight of the magnetic particles) was mixed with a Henschel mixer (Model FM20B, manufactured by Mitsui Miike Kakoki Co., Ltd.). ) And operated for 1 hour to coat the spherical magnetite particles.

The obtained magnetic particles to be treated had a contact angle of 128.9 °, and the saturation magnetization value and the coercive force were almost equal to the values before the treatment.

Comparative Example 1 The same spherical magnetite particle powder as in Example 1 was used, and “acetoalkoxy aluminum diisopropylate AL-M” (Ajinomoto Co., Ltd.) was used instead of the surface modifier of Example 1.
Was coated under the same conditions as in Example 1.

The obtained magnetic particles had a contact angle of 95.9 °, and the saturation magnetization and the coercive force were almost equal to the values before the treatment.

Example 2 Average particle size (long axis) 0.39 μm, axial ratio 7, specific surface area 2
2,000 g of acicular magnetite particles having 0.8 m ² / g, a saturation magnetization of 84.0 emu / g, and a coercive force of 359 Oe
And isopropoxy nonadecafluorodecanoyl aluminum ethyl acetoacetate (manufactured by Ajinomoto Co., Inc.) 80 g
(Corresponding to 4 parts by weight with respect to 100 parts by weight of the magnetic particles) into a Henschel mixer (Model FM20B, manufactured by Mitsui Miike Kakoki Co., Ltd.) and operated for 1 hour to obtain the needle-like shape. A coating treatment was performed on the surface of the magnetite particle powder.

The obtained magnetic particle powder to be treated has a contact angle of 1
The angle was 26.2 °, the saturation magnetization was 80.8 emu / g, and the coercive force was 360 Oe.

Comparative Example 2 The same acicular magnetite particle powder as in Example 2 was used, and “acetoalkoxy aluminum diisopropylate AL-M” (Ajinomoto Co., Ltd.) was used instead of the surface modifier of Example 2.
Manufactured under the same conditions as in Example 2.

The resulting magnetic particles had a contact angle of 93.5 °, a saturation magnetization of 80.6 emu / g and a coercive force of 361 Oe.

[0057]

According to the present invention, there are provided magnetic particle powders which are suitable for magnetic toners because they have high water repellency, are excellent in environmental stability, and are also excellent in dispersibility with a binder resin. It is where it is done.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Kazuo Fujioka 4-1-2, Funariminami, Naka-ku, Hiroshima-shi, Hiroshima Toda Kogyo Co., Ltd. (56) References JP-A-58-207052 (JP, A JP-A-60-254119 (JP, A) JP-A-64-7046 (JP, A) JP-A-3-255088 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/083

Claims (1)

(57) [Claims] 1. A magnetic particle powder for a magnetic toner comprising magnetic particles having a particle surface coated with a fluorocarbon chain-containing aluminum compound represented by the following general formula (1), (2) or (3). Embedded image However, in the general formulas (1), (2) and (3), n, m, L and b represent 1 or 2 (where n + L ≦ 3), and X and V each independently represent following binding (4) or -O- and represents, Y and W are each independently, -C _{K
H 2K -, - (C K} H 2K O) G - or a single covalent bond is shown - a represents (where, K is 1 to 30 integer, and G is 1,
R ¹ and R ² each independently represent an alkyl group having 1 to 30 carbon atoms, and R ^f is C _q F
_{2q + 1} or an _C q _{F 2q} H, A and B are each _{independently,} C _{p F 2p + 1} or an _C j _{H 2j + 1} O (where, p, q, j are each independently 1 to 30 integer And Z represents VR ² or VWR ^f . Embedded image