JP2002221817A - Toner and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner which prevents white void in a solid image even when a fixing device with an electromagnetic induction heating method is used in a low temperature environment. SOLUTION: The toner is used for such an image forming method that the method includes (i) a magnetic field generating means and (ii) a rotary heating member having at least a heat generating layer which generates heat by electromagnetic induction and that the method is carried out by generating heat in a part in the rotary heating member along its rotation direction to heat, press and fix a toner image on a recording material to form a fixed image. The toner contains at least a binder resin and a coloring agent, to which fine powder of hydrotalcite compounds expressed by general formula (1) is externally added. In formula (1), the suffixes satisfy 0<[X=(x1+x2+...+xk)]<=0.5 and Y=(y1+y2+...+yj)=1-X, j and k are integers 2 or more, each of M12+, M22+,...Mj2+ represents a different bivalent metal ion, each of L13+, L23+,...Lk3+ represents a different trivalent metal ion, An- is a n-valent anion and m>=0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image used in an electrostatic copying machine, a laser printer or the like, and to an image forming method using the toner.

[0002]

2. Description of the Related Art As a fixing device used in a copying machine, a printer, a facsimile or the like using an electrophotographic system, an electrostatic recording system, a magnetic recording system, a toner jet system, etc., a fixing roller or a fixing belt is used. Have been. FIG. 1 shows an embodiment of a fixing roller, and FIGS. 2 and 3 show an embodiment of a fixing belt.

In the fixing roller system shown in FIG. 1, a heat source such as a halogen lamp is provided on the rotating shaft of the roller to heat the roller surface layer equally and uniformly, whereas the fixing belt shown in FIGS. The method is characterized in that not a whole belt but a part of the belt is heated. In general,
The fixing belt method has an advantage that a quick start is possible as compared with the fixing roller method, and the size of the apparatus can be easily reduced. Therefore, the fixing belt method has been widely used in recent years.

As a method of applying heat to an unfixed toner image by using a fixing belt to fix the image on a recording material, there are known a method of externally heating the fixing belt and a method of heating the fixing belt itself. I have. Since the latter has better thermal efficiency than the former, the latter is easier to achieve in reducing total power consumption.

As a method of causing the fixing belt itself to generate heat, there is a method using electromagnetic induction. This means that the magnetic field generated by combining the core material, which is a magnetic material, and the coil is changed by the excitation circuit, and the eddy current is applied to the conductive layer (induction magnetic material) in the belt as the conductive member moving in the magnetic field. To be generated. This eddy current is converted into heat (Joule heat) by the electric resistance of the conductive layer, and the belt itself generates heat, resulting in a fixing device having excellent thermal efficiency.

On the other hand, metals, such as aluminum, nickel, and iron, which are the base material of the fixing belt or the fixing roller, or alloys thereof are deteriorated by being left in a high temperature state for a long period of time or by repeating a cycle of heating and cooling. It is generally well known to proceed. For example, Japanese Patent Laid-Open No. 9-1
Japanese Patent Publication No. 97862 discloses a relationship between a heating temperature and a cumulative heating time until nickel is crystallized and the substrate is cracked when continuously heated at that temperature when nickel is used as the base material of the fixing belt. It is shown. As a method of preventing such an excessive rise in temperature, a method of monitoring by providing a temperature sensor on the surface of a belt or a roller, or a method of stopping the heat supply for a while after stopping the heat supply as described in Japanese Patent Application Laid-Open No. A method of rotating a belt to prevent thermal deterioration of a part of the belt is known.

The present inventors have used these fixing methods,
Investigations to actually fix various toner images showed that despite setting the same fixing temperature,
It has been found that an image defect occurs when a fixing method in which a part of a rotating member is heated using an electromagnetic induction heating method is used.

After that, the present inventors conducted further detailed investigations and found that image defects were remarkably generated as white spots during fixing of all solid images (developed over the entire printable area). did. It also revealed that image defects are more likely to occur in a low-temperature environment.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner which prevents white spots on all solid images even when a fixing device of an electromagnetic induction heating type is used in a low temperature environment.

It is another object of the present invention to provide an image forming method capable of preventing white spots in all solid images and reducing total power consumption even when used in a low-temperature environment.

[0011]

The present invention comprises (i) a magnetic field generating means, and (ii) a rotary heating member having at least a heat generating layer that generates heat by electromagnetic induction, wherein the rotary heating member has a rotating direction. A toner used in an image forming method of forming a fixed image by heating and pressing and fixing a toner image on a recording material by heating a part thereof, wherein the toner contains at least a binder resin and a colorant, and The present invention relates to a toner characterized in that fine powder of a hydrotalcite compound represented by the following general formula (1) is externally added.

[0012]

Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k is an integer of 2 or more, M1 ^2+, M2 ^2+, ... and Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, ^An-
Represents an n-valent anion, and m ≧ 0. )

Further, the present invention provides a charging step of applying a voltage to a charging member from the outside to charge the electrostatic latent image carrier; a latent image forming an electrostatic latent image on the charged electrostatic latent image carrier. Image forming step; developing step of developing the electrostatic latent image with toner carried on the toner carrier and forming a toner image on the image carrier; recording material with or without the intermediate transfer member A fixing step of fixing a toner image on a recording material, wherein the fixing device comprises: (i) a magnetic field generating unit; and (ii) a heat generating layer that generates heat by electromagnetic induction. A fixing device for forming a fixed image by heating and pressurizing and fixing a toner image on a recording material by heating a part of the rotation heating member in the rotation direction, and forming a fixed image. At least the binder resin and the colorant A, and fine powder of hydrotalcite compound represented by the general formula (1) is an image forming method, characterized by being externally added.

[0014]

Embodiments of the present invention will be described in detail below.

As a result of intensive studies, the present inventors have found that by using a toner to which a fine powder of a hydrotalcite compound represented by the following general formula (1) is externally added, an electromagnetic induction heating method in a low-temperature environment is used. In the fixing test, it was found that white spots on all solid images could be prevented.

[0016]

Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k is an integer of 2 or more, M1 ^2+, M2 ^2+, ... and Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, ^An-
Represents an n-valent anion, and m ≧ 0. )

Although the detailed reason is unknown,
The occurrence of image defects differs depending on the difference in the area of heating or heat generation.Furthermore, in the fixing test after continuous printing of solid white images and the fixing test after continuous printing of all solid images, the results after continuous printing of all solid images are better. From phenomena such as bad results,
It is guessed as follows.

FIG. 4 schematically shows a change in temperature at an arbitrary point A on the surface layer of the fixing roller shown in FIG.
5 shows an arbitrary point A on the surface layer of the fixing belt shown in FIG.
3 schematically shows a change in temperature of the sample. At this time, the amount of heat taken by the recording material is ignored.

In the fixing roller shown in FIG. 1, since the roller surface layer is uniformly heated, the point A is gradually heated or cooled. In contrast, in the fixing belt shown in FIG. 6, point A is repeatedly subjected to rapid heating and cooling in order to heat or heat only a part of the belt. Considering that the rotating member for fixing used in the electromagnetic induction heating method is a composite of different materials such as metal and resin, this makes the constituent material of the rotating member susceptible to some damage. It is inferred that:

The resin used as a binder resin in the toner may contain a very small amount of volatile substances such as unreacted raw materials, residual initiator, organic solvents, and moisture. . It is considered that these volatile substances are released from the toner in the fixing process and act on the above-mentioned damaged portion, so that the thermal conductivity at that portion changes and heat is not evenly transmitted, resulting in white spots.

Here, when the hydrotalcite compound is externally added to the toner, one or both of i) acts on a damaged portion of the fixing member and ii) acts on a volatile substance from the toner. The effect of (1) works, and a fixed image defect can be prevented. It is not clear how to separate the effects of i) and ii), and the details thereof are not clear. However, since hydrotalcites compounds are generally used as acid scavengers, it seems that some kind of oxidation-reduction reaction is involved. It is.

The hydrotalcite compound used in the present invention has the following general formula (1)

[0023]

Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k is an integer of 2 or more, M1 ^2+, M2 ^2+, ... and Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, ^An-
Represents an n-valent anion, and the one represented by m ≧ 0) is used. That is, by using a solid solution in which two or more divalent metals and two or more trivalent metals are used,
The object of the present invention can be highly achieved.

Although the details are unknown, it is better to use a solid solution containing two or more divalent metals and two or more trivalent metals.
Compared with the case where one kind of the valent metal and one kind of the trivalent metal or the case where the kind of the divalent metal is two kinds or more and the kind of the trivalent metal is one kind, the image deterioration does not appear even in long-term use. .

The hydrotalcites having the above structure may contain a monovalent alkali metal. Further, a plurality of types of anions may be present.

The hydrotalcite compound is more preferably a compound represented by the following general formula (2).

[0027]

Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k are integers of 2 or more, M2, M3,.
L2, L3... and L different from each other selected from the group consisting of n, Ca, Ba, Ni, Sr, Cu and Fe.
k is a different metal selected from the group consisting of B, Ga, Fe, Co, and In, and ^An- represents an n-valent anion, m ≧ 0)

In the general formula (2), it is more preferable that the divalent metal and the trivalent metal satisfy the following relationship. y1> y2 +... + yj, more preferably, y1> 1
0x (y2 + ... + yj) x1> x2 + ... + xk, more preferably x1> 10 * (x2 + ... + xk), especially x
1> 20 × (x2 +... + Xk)

Further, it is preferable to satisfy 0.9 ≦ x1 + y1 <0.1, and 0.930 ≦ x1 + y1 ≦ 0.9.
It is more preferable that the ratio satisfies 98.

The content (atomic ratio) of divalent metals other than Mg is preferably 0.001 ≦ y2 +... + Yj ≦ 0.05, and the content (atomic ratio) of trivalent metals other than Al is preferred. , But preferably satisfies 0.0003 ≦ x2 +... Xk ≦ 0.02.

When a divalent metal other than Mg and a trivalent metal other than Al are contained in the above ranges, the effect of the present invention of preventing deterioration of the fixing member of the electromagnetic induction heating system is remarkable. It becomes something. When the content of the divalent metal other than Mg and the content of the trivalent metal other than Al exceeds the above range, the effect of preventing deterioration is reduced. In terms of properties, it tends to be inferior.

The hydrotalcite compounds are represented by M
More preferably, Ca is contained as a divalent metal other than g, and as the trivalent metal, B, G contained
The total amount of e, Fe, and Ga is 0.0003 to
More preferably, it is 0.02.

[0033] As A hydrotalcite for use in the present invention ^n-(n-valent anion) is, CO ₃ ^2-, OH ^-,
Cl ⁻ , I ⁻ , F ⁻ , Br ⁻ , SO ₄ ⁻ , HCO ₃ ⁻ , CH ₃ C
OO ^- and NO ₃ ^- are exemplified, and a single compound or a plurality of compounds may be present.

The hydrotalcite compound preferably has water in the molecule, and in the general formulas (1) and (2), 0.1 <m <0.6. More preferred.

The specific surface area of the hydrotalcites used in the present invention is preferably at least 1.0 m ² / g, more preferably 5.0 to ²⁰⁰ m ² / g.

The specific surface area was determined by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device, Auto Soap 1 (manufactured by Yuasa Ionics) according to the BET method, and calculating the specific surface area using the BET multipoint method.

The hydrotalcite used in the present invention is preferably subjected to a hydrophobizing treatment with a surface treating agent in order to stabilize the environment. As the surface treatment agent, higher fatty acids, coupling agents, esters, and oils such as silicone oil can be used.

Among them, higher fatty acids are preferably used,
Specifically, stearic acid, oleic acid, and lauric acid are exemplified.

The amount of the hydrotalcite compound to be added to the toner particles is preferably 0.03 to 3 parts by mass (more preferably 0.1 to 1.0 parts by mass) per 100 parts by mass of the toner particles.
0 parts by mass). If the addition amount is less than 0.03 parts by mass, the effect of the present invention will be insufficient, and if it exceeds 3 parts by mass, the environmental stability will be insufficient.

In order to further enhance the effects of the present invention,
It is also possible to apply the hydrotalcite compound to the surface of the substrate of the fixing rotating member; or to knead the hydrotalcite compound into the substrate portion of the fixing rotating member, in particular, the inside of the elastic layer. However, these treatments are merely auxiliary effects, and the effects of the present invention cannot be sufficiently obtained by these treatments alone. That is, the durability of the deterioration preventing action is poor.

Although the detailed reason is unknown, among the aforementioned effects of adding hydrotalcite, i.
i) The effect on volatiles from the toner appears to be dominant in the present invention.

In order to obtain a higher quality image in the present invention, the toner preferably has a weight average particle diameter of 3 to 10 μm. In the case of a toner having a weight average diameter of less than 3 μm, a large amount of toner remains on the photoreceptor due to a decrease in transfer efficiency, and is likely to cause non-uniform unevenness of an image due to fog or poor transfer. Is difficult to obtain, which is not preferable for the toner used in the present invention. Further, when the weight average particle diameter of the toner exceeds 10 μm, scattering of characters and line images tends to occur,
It is likely to cause toner fusion.

Further, it is more preferable that the binder resin contains polystyrene, and that the toner has a loss on heating up to 180 ° C. of 3.0% by mass or less. Although the details are unknown, when the binder resin is polystyrene, the effect of the present invention is further enhanced. It is presumed that the diffusion speed when the volatile substance exits from the toner has the factor. 2. Loss on heating of toner up to 180 ° C.
If it exceeds 0% by mass, the effect of the present invention tends to be poor.

The heating loss of the toner was measured using PE7700 and TGA7 manufactured by Perkin Elmer Co., Ltd. in a nitrogen atmosphere.
It is indicated by the weight loss when the sample is heated at a heating rate of 0 ° C./min.

When the toner satisfies the above conditions and contains the hydrotalcites as described above, the toner of the present invention has a more excellent and long-term action of preventing the fixing belt from deteriorating.

The other components in the present invention will be described.

The toner as the developer of the present invention usually contains a binder resin and a colorant.

As the binder resin of the toner according to the present invention,
In addition to polystyrene, a homopolymer of styrene and its substituted substances such as polyvinyl toluene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer , Styrene-ethyl acrylate copolymer,
Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer,
Styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-
Vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic acid resin,
Rosin, modified rosin, terpene resin, phenolic resin,
Aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, carnauba wax and the like can be used. These can be used alone or in combination.

As the colorant used in the toner according to the present invention, known dyes and pigments can be used. In particular,
As the black colorant, carbon black, a magnetic substance, and those toned to each color using the following yellow / magenta / cyan colorants are used.

Specific examples of the yellow colorant include compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds. In particular,
C. I. Pigment Yellow 12, 13, 14, 15,
17, 62, 74, 83, 93, 94, 95, 109,
110, 111, 128, 129, 147, 168, 1
80 and the like are preferably used.

Specific examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. . Specifically, C.I. I. Pigmentlets 2, 3, 5, 6, 7, 2
3, 48: 2, 48: 3, 48: 4, 57: 1, 81:
1, 122, 144, 146, 166, 169, 17
7, 184, 185, 202, 206, 220, 22
1, 254 are particularly preferred.

As the cyan colorant used in the present invention, specifically, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15; 3, 15:
4, 60, 62, 66, etc. can be used particularly preferably.

These colorants can be used alone or as a mixture or in the form of a solid solution.

When the colorant of the present invention is a color toner,
It is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner. The amount of the colorant added is
It is used by adding 1 to 20 parts by mass to 100 parts by mass of the resin.

When a magnetic material is used as the black colorant, unlike other colorants, 40 to 100 parts by mass of the resin is used.
Used by adding 150 parts by mass.

In the toner of the present invention, a charge control agent can be used if necessary.

The charge control agents used in the present invention include:
Although a known toner can be used, in the case of a color toner, a charge control agent which is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is particularly preferable.

Specific compounds include salicylic acid, naphthoic acid, dicarboxylic acid, metal compounds of their derivatives, sulfonic acid, high molecular compounds having carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds as negative compounds. Compounds, calixarenes and the like can be used, and quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, imidazole compounds and the like are preferably used as the positive system.

The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the resin. However, in the present invention, the addition of a charge control agent is not indispensable, and the toner need not necessarily contain a charge control agent by actively utilizing frictional charging with the blade member or the sleeve member.

In the toner of the present invention, a substance having a low softening point, so-called wax, can be used as a release agent, if necessary.

Examples of the low softening point substance used in the toner of the present invention include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax, Fischer-Tropsch wax, amide wax, higher fatty acid, long-chain alcohol, ester wax and the like. Derivatives such as a graft compound and a block compound are preferred, and those having a sharp maximum endothermic peak in a DSC endothermic curve from which low molecular weight components have been removed are preferred.

The wax preferably used is a linear alkyl alcohol having 15 to 100 carbon atoms, a linear fatty acid, a linear acid amide, a linear ester, or a montan derivative. It is also preferable that impurities such as liquid fatty acids have been removed from these waxes in advance.

Further, preferably used wax is
Low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or low pressure under Ziegler catalyst or other catalyst; alkylene polymer obtained by thermal decomposition of high molecular weight alkylene polymer; A product obtained by separating and purifying a low-molecular-weight alkylene polymer produced as a by-product; from a synthetic polymer gas consisting of carbon monoxide and hydrogen, obtained from the distillation residue of a hydrocarbon polymer obtained by the Age method, or a synthetic carbon obtained by hydrogenating the distillation residue. A polymethylene wax obtained by extracting and separating a specific component from hydrogen can be used. An antioxidant may be added to these waxes.

The low softening point substance used in the present invention is DS
The C endothermic curve preferably has an endothermic main peak in a region of 40 to 90 ° C (more preferably 45 to 85 ° C). Further, the endothermic main peak has a half width of 1
A material having a low softening point having a sharp melt property of 0 ° C. or less (more preferably 5 ° C. or less) is preferable. In particular, an ester wax whose low softening point substance is an ester wax mainly containing an ester compound of a long-chain alkyl alcohol having 15 to 45 carbon atoms and a long-chain alkyl carboxylic acid having 15 to 45 carbon atoms is preferable.

The ester wax used in the present invention is formed of a compound represented by the following formulas (I) to (VI) and has a melting point of 40 to 100 ° C.

[0066]

Embedded image (Where a and b are integers from 0 to 4, and a + b is 4
It is. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and the difference between R ₁ and R ₂ is 3 or more. m and n are integers from 0 to 25, and m and n do not become 0 at the same time. )

[0067]

Embedded image (Where a and b are integers of 0 to 3, and a + b is 1 to 3)
3. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and the difference between R ₁ and R ₂ is 3 or more. R ₃ is a hydrogen atom and an organic group having 1 or more carbon atoms. Where a + b =
In the case of 2, one of R ₃ is an organic group having 1 or more carbon atoms. k is an integer of 1 to 3. m and n are 0 to
This is an integer of 25, and m and n do not become 0 at the same time. )

[0068]

Embedded image (Wherein, R ₁ and R ₃ are organic groups having 6 to 32 carbon atoms, and R ₁ and R ₃ may or may not be the same.
₂ represents an organic group having 1 to 20 carbon atoms. )

[0069]

Embedded image (Wherein R ₁ and R ₂ are organic groups having 6 to 32 carbon atoms, and R ₁ and R ₃ may or may not be the same.
_{2 -CH 2 CH 2 OC 6 H 4} OCH 2 CH 2 -,

[0070]

Embedded image (In the formula, a is an integer of 0 to 4, b is an integer of 1 to 4, a + b is 4. R ₁ is an organic group having 1 to 40 carbon atoms. M and n are 0. An integer of 〜25, m and n
Do not become 0 at the same time. )

[0071]

Embedded image (Wherein R ₁ and R ₂ are the same or different and each have 15 to 45 carbon atoms)
Represents a hydrocarbon group. )

Specifically, the following ester waxes are preferably used. In addition, the ester wax in the examples and comparative examples of the present invention refers to those containing 50% or more of the compound having the following structural formula.

[0073]

Embedded image

[0074]

Embedded image

When an ester wax having the above structural formula is used, good transparency is exhibited and good fixability is exhibited.

For the measurement of the temperature of the maximum peak value of the present invention, for example, DSC-7 manufactured by PerkinElmer Co., Ltd. is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

The low softening point substance is preferably contained in the toner particles in an amount of preferably 3 to 40 parts by mass, more preferably 5 to 35 parts by mass, based on 100 parts by mass of the binder resin.

When the content of the low softening point substance is less than 3 parts by mass, it is difficult to obtain sufficient high-temperature offset resistance, and further, at the time of fixing the image on both surfaces of the recording material, at the time of the second (back) fixing. The first (front) image offset may occur.

When the content of the low softening point substance exceeds 40 parts by mass, when the toner particles are produced by a pulverization method during the production of the toner, the toner components are easily fused in the toner production apparatus. In the case where toner particles are produced by a polymerization method, granulation properties are reduced during granulation, and toner particles are likely to coalesce.

The toner using these wax components has an endothermic peak in the range of 20 to 200 ° C. at the time of temperature rise measurement and a maximum endothermic peak at 50 to 150 ° C. in the DSC curve measured by the differential scanning calorimeter. It is preferable to have one. In addition, in the DSC curve measured by the differential scanning calorimeter, 20 to
It is more preferred that the exothermic peak has an exothermic peak in the region of 200 ° C. and the maximum exothermic peak in the range of 40 to 150 ° C. By having an endothermic peak and a maximum endothermic peak in the above-mentioned temperature range, it greatly contributes to low-temperature fixing, and also effectively expresses the releasability, so that matching with the fixing method of the present invention becomes good. When the endothermic peak is below 20 ° C., the high-temperature offset property of the toner is significantly impaired,
If the temperature exceeds 200 ° C., the low-temperature fixability of the toner is significantly impaired. If the maximum endothermic peak is less than 50 ° C. at the time of temperature rise measurement and less than 40 ° C. at the time of temperature decrease measurement, the self-cohesive force of the wax component becomes weak, and as a result, the high-temperature offset property deteriorates. On the other hand, if the maximum endothermic peak exceeds 150 ° C., the fixing temperature becomes high and low-temperature offset is likely to occur, which is not preferable.

The method of producing the toner particles of the present invention includes known methods such as a pulverization method / suspension polymerization method / a method of aggregating particles obtained by emulsion polymerization to obtain a toner / interfacial polymerization method / dispersion polymerization. Although it can be used, any method may be used as long as it falls within the scope of the present invention.

When the pulverization method is used as the production method of the present invention, the resin, the release agent, the colorant, the charge control agent and the like are uniformly dispersed using a pressure kneader, an extruder or a media disperser, and then further dispersed. Through a classification step, the particle size distribution is sharpened to form a toner.

When a polymerization method by suspension polymerization is used, a releasing agent, a coloring agent, a charge control agent, a polymerization initiator and other additives are added to the polymerizable monomer, and a homogenizer / ultrasonic dispersion is used. The monomer composition uniformly dissolved or dispersed by an apparatus or the like is dispersed in an aqueous phase containing a dispersion stabilizer by a homomixer or the like. The granulation is stopped when the desired toner particle size is obtained from the droplets of the monomer composition. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization temperature is 40 ° C. or higher, generally 5
The polymerization is carried out at a temperature of 0 to 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction, and furthermore, in order to remove unreacted polymerizable monomers and by-products in the latter half of the reaction, or by partially distilling off the aqueous medium after the completion of the reaction. Is also good. After the reaction,
The generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer composition.

In the present invention, when toner particles are obtained by a polymerization method, styrene, styrene,
styrene-based monomers such as o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, ( Butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylate monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene,
Ene monomers such as (meth) acrylonitrile and acrylamide are preferably used. These may be used alone or generally in the published Polymer Handbook, 2nd edition III-
The theoretical glass transition temperature (Tg) described in P139-192 (manufactured by John Wiley & Sons) is 40-8.
The monomers are appropriately mixed and used so as to show 0 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems arise in terms of the storage stability of the toner and the durability stability of the developer. In this case, the color mixture of each color toner is insufficient and the color reproducibility is poor, and the transparency of the OHP image is remarkably reduced, which is not preferable from the viewpoint of high image quality.

In the method of obtaining toner particles using the polymerization method, it is particularly preferable to add a polar resin at the same time from the viewpoint of allowing the polymerization reaction of the polymerizable monomer to be carried out without inhibition. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a polyester resin, and an epoxy resin are preferably used. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with a monomer in the molecule.

As the polymerization initiator used in the present invention, for example, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo-based polymerization initiators such as dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-
A peroxide-based polymerization initiator such as dichlorobenzoyl peroxide and lauroyl peroxide is used.

The particle size distribution and the particle size of the toner are controlled by changing the type and amount of the hardly water-soluble inorganic salt or the dispersant which acts as a protective colloid, and the mechanical device conditions, for example, the peripheral speed and pass of the rotor. It can be achieved by controlling the stirring conditions such as the number of times and the shape of the stirring blade, the shape of the container, or the solid content concentration in the aqueous solution.

In the toner of the present invention, in addition to the fine particles of the present invention, organic or inorganic fine particles generally widely known as external additives may be added as long as the effects of the present invention are not impaired. It is possible. Specifically, examples of inorganic fine particles include metal oxides (such as aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, and zinc oxide), nitrides (such as silicon nitride), and carbides (such as silicon nitride). Metal salts (such as calcium sulfate, barium sulfate, and calcium carbonate), fatty acid metal salts (such as zinc stearate and calcium stearate), carbon black, and silica can be used. Examples of the organic fine particles include homopolymers or copolymers of monomer components such as styrene, acrylic acid, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, which are used in a binder resin for a toner, obtained by an emulsion polymerization method or a spray drying method. Polymers can be used.

Further, if necessary, a plurality of these fine particles can be used in combination.

A specific example of a fixing device that can be used in the present invention will be described below. 6 to 13 show a fixing device having an exciting coil portion inside the belt and having a mechanism for heating the belt itself by electromagnetic induction. The heating and fixing device of the present invention is not limited to the illustrated one, and may be, for example, a heating and fixing device having a configuration in which an exciting coil portion is provided outside the belt.

FIG. 6 is a schematic cross-sectional side view of an essential part of the fixing device 100 of the electromagnetic induction heating type according to the present invention, FIG. 7 is a schematic front view of the essential part, and FIG. It is shown.

The apparatus 100 of this embodiment is a pressure roller driving system and an electromagnetic induction heating system using a cylindrical electromagnetic induction heating belt, similarly to the fixing device of FIG. The same reference numerals are given to the same constituent members and portions as those in the apparatus of FIG. 13 and the description will not be repeated.

The magnetic field generating means includes the magnetic cores 17a, 17b,
17c and the exciting coil 18. Magnetic core 17a
17b and 17c are members having a high magnetic permeability, and are preferably made of a material used for a transformer core such as ferrite or permalloy, and more preferably a ferrite having a small loss even at 100 kHz or more.

The exciting coil 18 has power feeding portions 18a and 18b.
Is connected to an excitation circuit 27 (FIG. 9). The excitation circuit 27 can generate a high frequency of 20 kHz to 500 kHz by a switching power supply.

The exciting coil 18 generates an alternating magnetic flux by an alternating current (high-frequency current) supplied from the exciting circuit 27.

Reference numerals 16a and 16b denote belt guide members of a trough type having a substantially semicircular arc cross section. The belt guide members have substantially cylindrical bodies with their opening sides facing each other, and a fixing belt which is a cylindrical electromagnetic induction heating belt on the outside. 10 is loosely fitted.

The belt guide member 16a holds a magnetic core 17a, 17b, 17c as a magnetic field generating means and an exciting coil 18 inside.

Further, the belt guide member 16a has the structure shown in FIG.
As shown in FIG. 2, a good heat conducting member 40 extending in the direction perpendicular to the paper surface is disposed inside the fixing belt 10 on the side of the nip portion N facing the pressure roller 30.

In this example, aluminum is used for the good heat conductive member 40. The good heat conducting member 40 has a heat conductivity k = 240 [W · m ⁻¹ · K ⁻¹ ] and a thickness of 1
[Mm].

The good heat conducting member 40 comprises an exciting coil 18 as a magnetic field generating means and magnetic cores 17a, 17b, 17
It is arranged outside this magnetic field so as not to be affected by the magnetic field generated from c.

Specifically, the good heat conducting member 40 is disposed at a position separated from the exciting coil 18 by the magnetic core 17c.
It is positioned outside the magnetic path by the exciting coil 18 so as not to affect the good heat conductor 40.

Reference numeral 22 denotes a horizontally-long pressurizing rigid stay disposed in contact with the inner flat surface of the belt guide member 16b.

Reference numeral 19 denotes the magnetic cores 17a, 17b, 17c
And an insulating member for insulating between the exciting coil 18 and the rigid stay for press 22.

The flange members 23a and 23b are externally fitted to the left and right ends of the assembly of the belt guide members 16a and 16b, and are rotatably mounted while fixing the left and right positions.
When the fixing belt 10 rotates, the fixing belt 10 receives the end of the fixing belt 10 and serves to regulate the shifting of the fixing belt along the length of the belt guide member.

The pressure roller 30 as a pressure member is made of a heat-resistant and elastic material such as silicone rubber, fluoro rubber, fluoro resin, etc., which is formed by concentrically forming a roller around the core metal 30a. The core 30a is arranged so that both ends of the core 30a are rotatably supported by bearings between sheet metal (not shown) of the apparatus.

The pressing springs 25a and 25b are respectively contracted between both ends of the rigid pressing stay 22 and the spring receiving members 29a and 29b on the apparatus chassis side, so that a pressing force is applied to the pressing structural stay 22. Let me. As a result, the lower surface of the belt guide member 16a and the upper surface of the pressure roller 30 are pressed against each other with the fixing belt 10 interposed therebetween, thereby forming a fixing nip portion N having a predetermined width.

The pressure roller 30 is driven to rotate by the driving means M in the direction indicated by the arrow. A rotational force acts on the fixing belt 10 by a frictional force between the pressing roller 30 and the outer surface of the fixing belt 10 due to the rotational driving of the pressing roller 30, and the inner surface of the fixing belt 10 has good heat conduction in the fixing nip N. The outer circumference of the belt guide members 16a and 16b is rotated at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 30 in the direction of the arrow while sliding in close contact with the lower surface of the member 40.

In this case, in order to reduce the mutual sliding friction force between the lower surface of the good heat conducting member 40 in the fixing nip N and the inner surface of the fixing belt 10, the lower surface of the good heat conducting member 40 in the fixing nip N is fixed. A lubricant such as heat-resistant grease may be interposed between the inner surface of the belt 10 and the lower surface of the good heat conductive member 40 may be covered with a lubricating member. This is because when the surface sliding property is not good in material such as the case where aluminum is used as the good heat conducting member 40 or when the finishing process is simplified, the sliding fixing belt 10 is damaged and the fixing belt 10 is damaged. This is to prevent the durability of the device from being deteriorated.

The good heat conducting member 40 has an effect of making the temperature distribution in the longitudinal direction uniform. For example, when small size paper is passed, the heat amount of the non-sheet passing portion of the fixing belt 10 is reduced by the good heat conducting member. Heat is transferred to the small-size paper passing portion by the heat conduction in the longitudinal direction of the good heat conducting member 40. As a result, an effect of reducing power consumption when passing small-sized paper is also obtained.

As shown in FIG. 9, the peripheral surface of the belt guide member 16a is provided with convex ribs 16e at predetermined intervals along the length thereof.
The contact sliding resistance between the peripheral surface of the fixing belt 10 and the inner surface of the fixing belt 10 is reduced to reduce the rotational load of the fixing belt 10.
Such a convex rib portion can be similarly formed and provided on the belt guide member 16b.

FIG. 10 schematically shows how alternating magnetic flux is generated. The magnetic flux C represents a part of the generated alternating magnetic flux. The alternating magnetic flux (C) guided to the magnetic cores 17a, 17b, and 17c is applied to the electromagnetic induction heating layer 1 of the fixing belt 10 between the magnetic cores 17a and 17b and between the magnetic cores 17a and 17c. An eddy current is generated. This eddy current generates Joule heat (eddy current loss) in the electromagnetic induction heating layer 1 due to the specific resistance of the electromagnetic induction heating layer 1. The heat value Q here is determined by the density of the magnetic flux passing through the electromagnetic induction heating layer 1, and shows a distribution as shown in the graph of FIG. In the graph of FIG. 10, the vertical axis indicates the circumferential position of the fixing belt 10 represented by the angle θ with respect to the center of the magnetic core 17 a as 0, and the horizontal axis indicates the heat generation in the electromagnetic induction heating layer 1 of the fixing belt 10. Indicates the quantity Q. Here, the heating area H is defined as an area where the heating value is Q / e or more, where Q is the maximum heating value. This is an area where a heat value required for fixing can be obtained.

The temperature of the fixing nip N is controlled such that a predetermined temperature is maintained by controlling the current supply to the exciting coil 18 by a temperature control system including a temperature detecting means (not shown). Reference numeral 26 denotes a temperature sensor such as a thermistor for detecting the temperature of the fixing belt 10. In this embodiment, the temperature of the fixing nip N is controlled based on the temperature information of the fixing belt 10 measured by the temperature sensor 26. I have.

When the fixing belt 10 rotates, the power is supplied from the excitation circuit 27 to the excitation coil 18 to generate electromagnetic induction of the fixing belt 10 as described above, and the fixing nip N rises to a predetermined temperature. The unfixed toner image t conveyed from the image forming unit in the temperature-controlled state
Is introduced between the fixing belt 10 and the pressure roller 30 in the fixing nip portion N, with the image surface facing upward, that is, opposed to the fixing belt surface. The fixing nip N is conveyed together with the fixing belt 10 in close contact with the outer surface of the fixing belt 10. The fixing nip N is fixed to the recording material P together with the fixing belt 10.
Is heated by the electromagnetic induction heating of the fixing belt 10 so that the unfixed toner image t on the recording material P is heated and fixed. When the recording material P passes through the fixing nip portion N, it is separated from the outer surface of the rotary fixing belt 10 and is discharged and conveyed. After passing through the fixing nip, the heat-fixed toner image on the recording material is cooled and becomes a permanent fixed image.

In the electromagnetic induction heating fixing method, the following is more preferable.

In the fixing device using the electromagnetic induction heating method, before and after the nip formed by the rotary heating member and the rotary pressing member, the temperature Z1 (° C.) of the rotary member on the recording material entry side and the temperature Z1 (° C.) The temperature Z2 (° C.) of the rotary heating member on the side where the recording material is discharged and the temperature Z3 (° C.) of the rotary heating member before reaching the portion where the rotary member generates heat satisfy the following condition: Z3 ≦ Z2 <Z1. After extensive studies, the present inventors have found that excellent fixing performance is exhibited when performing the fixing.

In particular, when the temperature is within the above-mentioned range, the toner of the recording material is quickly melted at the highest temperature at the recording material entry side in the nip, and has a sufficient fixing strength even at the time of quick start.

Since the temperature at the nip exit is lower than the temperature at the entry side, it is possible to effectively prevent the toner melted quickly at the nip entrance from sticking the recording material to the heating member.

As another effect, when the temperature Z1 of the heating rotary member on the recording material entry side is high, before the recording material enters the nip, not a small amount of toner and recording material due to radiant heat from the surface of the heating rotary member. It is considered that the heated nip has a function of assisting the heating by the nip and has an effect of contributing to the improvement of the fixing property.

Further, by keeping the temperature of the rotary heating member before reaching the portion where the rotating member generates heat to be equal to or lower than the temperature on the side where the recording material is discharged, excessive overheating is prevented when reaching the portion where the rotating member generates heat. can do.

Here, Z1, Z2 and Z3 are measured at positions described below. With reference to the nip center, the surface temperature of the heating member at a position on the recording material entry side that is one eighth of the circumference of the heating member is defined as Z1. Similarly, in Z2, based on the nip center,
It refers to the surface temperature of the heating member at a position on the side where the recording material is discharged and one eighth of the circumference of the heating member. Z3
Is the temperature obtained by measuring a range of 1/8 of the circumference in the direction opposite to the rotation of the rotary heating member immediately after the passage through the nip and immediately before the position where the heating means generates heat. FIG. 19 shows an example of measurement sites of Z1, Z2, and Z3.

The measurement site is as described above.
When measuring Z1, Z2, and Z3, the temperature is obtained by measuring the temperature when the recording material is passed.

As the recording paper, a recording material having a basis weight of 75 g / m ² (for example, Xerox Corporation 4024) was used, and the measurement was performed at 23 ° C. and 60% RH. Use temperature- and humidity-controlled ones.

At Z1, the surface temperature of the rotary heating member corresponding to the portion where the rotary heating member comes into contact with the recording material when passing through the recording material is recorded, and the maximum value is defined as Z1.

In Z2, the surface temperature of the rotary heating member corresponding to a portion where the rotary heating member comes into contact with the recording material when passing through the recording material is recorded, and the minimum value is set as Z2.

In Z3, the surface temperature of the rotary heating member corresponding to the portion where the rotary heating member comes into contact with the recording material when passing through the recording material is recorded, and the minimum value is set as Z3.

In order to satisfy the above conditions, the outer diameter, heat capacity and rotation speed of the heating member, the amount of electric power supplied to the heating member, the position of the rotating heating member where heat is to be generated, the outer diameter or heat capacity of the pressing member, It can be achieved by a suitable combination such as the rotation speed of the fixing device.

With respect to the circumferential length La of the heating member, at least the heat generating layer is heated in a range from the point of the recording material entry side La / 4 to the point of the recording material discharge side La / 8 with respect to the nip center. In addition, the temperature unevenness of the heating member near the nip can be suppressed, and the unevenness of fixing can be effectively prevented.

Preferably, Z1 is set to a temperature of less than 250 ° C. in consideration of efficient use of energy, and the difference between Z1 and Z2 is set to 40 ° C. or less, preferably 30 ° C. or less. This is preferable in order to maintain a high-quality fixed image. A fixing method that satisfies the above condition is preferable because sufficient fixing performance is maintained even in an environment that is severe in fixing under low temperature and low humidity.

Further, the circumferential length La of the rotary heating member and the circumferential length Lb of the rotary pressing member of the fixing device used in the present invention satisfy the following condition: {0.4 × La} ≦ Lb ≦ {0.95 × La} <400
mm 2. By reducing the circumference of the rotary heating member, the transfer of heat quantity from the heating member to the rotary member can be suppressed to a small extent, and the heat followability on the fixing surface can be improved and the quick start property can be improved.

In addition, by setting the circumference of the rotary pressing member in the above range and suppressing the heat transfer from the heating member, the rotary heating member can be preferably used up to about 400 mm.

More preferably, the endothermic peak of the toner by DSC (measurement of temperature rise) is at 20 to 200 ° C., and the maximum endothermic peak is located at 50 ° C. to 150 ° C. ℃ or less, preferably 40 ℃
It is preferred that the toner be positioned at the following temperature, since the toner can be sufficiently melted at the nip entrance and further excellent fixability is exhibited.

More preferably, the toner has an exothermic peak measured by DSC (temperature drop measurement) at 20 to 200 ° C., and its maximum exothermic peak is preferably located at 40 ° C. to 150 ° C., and the temperature is preferably lower than Z2. This position is preferable because the adhesion of the toner to the heating rotary member at the nip exit can be improved.

Regarding the safety device of the electromagnetic induction heating fixing device,
It is described below.

In the present embodiment, as shown in FIG. 6, a thermo-detecting element, which is a temperature detecting element, is provided at a position of the fixing film 10 opposite to the heat generating area H (FIG. 10) in order to cut off power supply to the exciting coil 18 during runaway. A switch 50 is provided.

FIG. 11 is a circuit diagram of the safety circuit used in this example. Thermo switch 50 which is a temperature detecting element is +2
The 4 VDC power supply and the relay switch 51 are connected in series. When the thermo switch 50 is turned off, the power supply to the relay switch 51 is cut off, the relay switch 51 operates, and the power supply to the excitation circuit 27 is cut off. The power supply to the exciting coil 18 is interrupted. The thermoswitch 50 set the OFF operation temperature to 220 ° C.

The thermoswitch 50 is disposed on the outer surface of the fixing film 10 in a non-contact manner so as to face the heat generating area H of the fixing film 10. The distance between the thermoswitch 50 and the fixing film 10 was about 2 mm. Accordingly, the fixing film 10 is not damaged by the contact of the thermoswitch 50, and the deterioration of the fixed image due to durability can be prevented.

According to this embodiment, when the fixing device goes out of control due to a device failure, unlike the configuration in which heat is generated in the fixing nip N as shown in FIG. Power is continuously supplied to the coil 18 and the fixing film 10
Even if the paper continues to generate heat, the paper is not directly heated because no heat is generated in the fixing nip portion N where the paper is sandwiched. Further, since the thermoswitch 50 is provided in the heat generation region H where the amount of heat generation is large,
When the temperature of 20 ° C. is sensed and the thermo switch is turned off, the power supply to the exciting coil 18 is cut off by the relay switch 51.

According to the present example, the ignition temperature of the paper is about 400 ° C.
Since it is near, heat generation of the fixing film can be stopped without firing the paper.

A temperature fuse can be used as the temperature detecting element in addition to the thermoswitch.

In this embodiment, the fixing device is not provided with an oil application mechanism for preventing offset, but may be provided with an oil application mechanism when using a toner not containing a low softening substance. Also, when a toner containing a low softening substance is used, oil application or cooling separation may be performed.

The configuration of the fixing device will be described more specifically.

A. Excitation Coil 18 The excitation coil 18 uses a bundle (bundle) of a plurality of copper thin wires, each of which is insulated and coated, as a conducting wire (electric wire) constituting a coil (wire loop). It is wound to form an exciting coil. In this example, the exciting coil 18 is formed by winding 10 turns.

As the insulating coating, a coating having heat resistance is preferably used in consideration of heat conduction due to heat generation of the fixing belt 10.
For example, a coating of amide imide or polyimide may be used.

The density of the excitation coil 18 may be improved by applying an external pressure.

The shape of the exciting coil 18 is set along the curved surface of the heat generating layer as shown in FIG. In this embodiment, the distance between the heating layer of the fixing belt and the exciting coil 18 is set to be about 2 mm.

As the material of the excitation coil holding member 19, a material having excellent insulation properties and good heat resistance is preferable. For example, a phenol resin, a fluorine resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PEEK resin, a PES resin, a PPS resin, a PFA resin, a PTFE resin, a FEP resin, an LCP resin, or the like may be selected.

The closer the distance between the magnetic cores 17a, 17b, 17c and the exciting coil 18 and the heat generating layer of the fixing belt is to the extent possible, the higher the efficiency of absorbing magnetic flux. Since the efficiency is remarkably reduced, it is preferable to set the thickness within 5 mm. If the distance is within 5 mm, the distance between the heating layer of the fixing belt 10 and the exciting coil 18 does not need to be constant.

Excitation coil holding member 19 of excitation coil 18
, That is, 18a and 18b (FIG. 9), the outside of the bundled wire is insulated from the excitation coil holding member 19 with respect to the outside.

B. Fixing Belt 10 FIG. 12 is a schematic diagram of a layer configuration of the fixing belt 10 in this example. The fixing belt 10 of the present embodiment has a heating layer 1 made of a metal belt or the like which is a base layer of the fixing belt 10 of electromagnetic induction heat generation.
And an elastic layer 2 laminated on its outer surface and a release layer 3 laminated on its outer surface. A primer layer (not shown) may be provided between each layer for adhesion between the heat generating layer 1 and the elastic layer 2 and adhesion between the elastic layer 2 and the release layer 3.
In the fixing belt 10 having a substantially cylindrical shape, the heat generating layer 1 is on the inner surface side, and the release layer 3 is on the outer surface side. As described above, the alternating magnetic flux acts on the heat generating layer 1 so that the heat generating layer 1
An eddy current is generated in the heat generating layer 1 to generate heat. The heat heats the fixing belt 10 via the elastic layer 2 and the release layer 3,
The recording material P as the material to be heated passed through the fixing nip N is heated to heat and fix the toner image.

A. Heating Layer 1 The heating layer 1 is preferably made of a ferromagnetic metal such as nickel, iron, ferromagnetic SUS, and nickel-cobalt alloy.

A non-magnetic metal may be used, but more preferably a metal such as nickel, iron, magnetic stainless steel, and a cobalt-nickel alloy having good magnetic flux absorption.

It is preferable that the thickness is larger than the skin depth represented by the following formula and 200 μm or less. The skin depth σ [m] is determined by the frequency f [Hz] of the excitation circuit and the magnetic permeability μ.
Is expressed as σ = 503 × (ρ / fμ) ^1/2 with the specific resistance ρ [Ωm].

This indicates the depth of absorption of electromagnetic waves used in electromagnetic induction. At a depth deeper than this, the intensity of the electromagnetic waves is 1 / e or less. Absorbed in.

The thickness of the heating layer 1 is preferably 1 to 200 μm.
m is good. If the thickness of the heat generating layer 1 is smaller than 1 μm, most of the electromagnetic energy cannot be absorbed, so that the efficiency is deteriorated. On the other hand, if the heat generating layer exceeds 200 μm, the rigidity becomes too high, and the flexibility deteriorates, which is not practical for use as a rotating body.

B. Elastic Layer 2 The elastic layer 2 is made of silicone rubber, fluorine rubber, fluorosilicone rubber, or the like, and has good heat resistance and good thermal conductivity.

The thickness of the elastic layer 2 is set at 10 to prevent unevenness in gloss due to the fact that the heating surface (release layer 3) cannot follow the unevenness of the recording material or the unevenness of the toner layer when printing an image. 500 μm is preferred.

If the thickness of the elastic layer 2 is less than 10 μm, the function as an elastic member is not exhibited, and the pressure distribution at the time of fixing becomes non-uniform. In addition to the fact that the toner cannot be sufficiently heated and fixed to cause unevenness in the gloss of the fixed image, the insufficient color of the toner deteriorates the color mixing of the toner due to insufficient melting, and a high-definition full-color image cannot be obtained.
When the thickness of the elastic layer 2 exceeds 500 μm, thermal conductivity during fixing is impaired, and heat followability on the fixing surface is deteriorated.
This is not preferred because fixing unevenness is likely to occur.

If the hardness of the elastic layer 2 is too high, the unevenness of the recording material or the toner layer cannot be completely followed, and uneven image gloss occurs. Therefore, the hardness of the elastic layer 2 is 60 ° (JIS-A) or less, more preferably 45 ° (J-A).
IS-A) The following is preferred.

Regarding the thermal conductivity λ of the elastic layer 2, 0.25 to 0.82 [J / m · sec · deg. ] Is good.

When the thermal conductivity λ is 0.25 [J / m · sec ·
deg. ], The thermal resistance is large, and the temperature rise in the surface layer (release layer 3) of the fixing belt becomes slow. Thermal conductivity λ is 0.82 [J / m · sec · de]
g. ], The hardness becomes too high and the compression set becomes worse.

Therefore, the thermal conductivity λ is 0.25 to 0.82
[J / m · sec · deg. ] Is good. More preferably, 0.33 to 0.63 [J / m · sec · deg. ] Is good.

C. Release Layer 3 Release layer 3 is made of fluororesin, silicone resin, fluorosilicone rubber, fluororubber, silicone rubber, PFA, P
A material having good releasability and heat resistance, such as TFE and FEP, can be selected.

The thickness of the release layer 3 is preferably 1 to 100 μm. If the thickness of the release layer 3 is less than 1 μm, there arises a problem that uneven coating of the coating film causes a part having poor releasability or insufficient durability. In addition, when the release layer exceeds 100 μm, there is a problem that heat conduction is deteriorated. In particular, in the case of a resin release layer, the hardness becomes too high, and the effect of the elastic layer 2 is lost.

D. Heat Insulating Layer 4 In the configuration of the fixing belt 10, a heat insulating layer 4 (not shown) may be provided on the belt guide surface side of the heat generating layer 1 (the side opposite to the elastic layer 2 of the heat generating layer 1).

The heat insulating layer 4 is made of fluororesin, polyimide resin, polyamide resin, polyamideimide resin, PE
EK resin, PES resin, PPS resin, PFA resin, PT
A heat-resistant resin such as FE resin or FEP resin is preferable.

The thickness of the heat insulating layer 4 is 10 to 10
00 μm is preferred. When the thickness of the heat insulating layer 4 is smaller than 10 μm, the heat insulating effect cannot be obtained, and the durability is insufficient. On the other hand, if it exceeds 1000 μm, the magnetic core 17a
The distance from the heating coils 1 to 17b and 17c and the exciting coil 18 is increased, and the magnetic flux is not sufficiently absorbed by the heating layer 1.

Since the heat insulating layer 4 can insulate the heat generated in the heat generating layer 1 so as not to go to the inside of the fixing belt, the heat supply efficiency to the recording material P side can be improved as compared with the case where the heat insulating layer 4 is not provided. Get better. Therefore, power consumption can be suppressed.

C. Nip In the heat fixing device of the present invention, the fixing nip portion N composed of the rotary heating member and the pressurizing agent forms a nip having a width of 5.0 to 15.0 mm in order to secure a good fixing property. Is preferred. The width of the fixing nip N portion is 5.0 [mm]
In the following, when forming a full-color image, the amount of heat for fixing the toner cannot be sufficiently given to the unfixed toner, and the toner cannot be melt-mixed, resulting in an unnatural color image.

The width of the fixing nip N portion is 15.0 [m
m] or more, although a sufficient amount of heat for fixing the toner can be given, hot offset during fixing is likely to occur, and both ends 10a of the fixing nip portion N
At the upstream end and the downstream end of the fixing film 10, the change in curvature becomes too large, and the durability of the fixing film 10 is undesirably deteriorated.

D. Surface pressure Pressure (surface pressure) at the nip in the heat fixing device of the present invention.
Indicates a surface pressure of 9.0 to 500 kN /
m ² is preferable, and the surface pressure is more preferably in the range of 30 to 350 kN / m ² .

If the surface pressure is less than 9.0 kN / m ^2, it is not preferable because the recording material is easily conveyed and the fixing pressure is insufficient to cause a defective fixing. When the surface pressure is 500 kN / m ² or more, the durability of the fixing film 10 is significantly deteriorated, which is not preferable.

The surface pressure here is calculated by the following equation from the pressure applied to the transfer material and the length Lr in contact.

[0173]

(Equation 1)

The pressure applied to the transfer material can be adjusted by the spring pressures 25a and 25b in FIG.
That is, the surface pressure is controlled by arbitrarily changing the spring constant of the spring used for 25a and 25b. Also,
By controlling the distance between the spring stopper positions 29a and 29b and the pressure roller 30, the fixing nip can be adjusted to control the surface pressure.

The pressure applied to the transfer roller 2 is usually
This is performed by pressurizing the end bearing a. In the case of the transfer belt 4 shown in FIG. 6, the transfer belt 4 is supported and driven by the conductive roller 5, and is adjusted so as to have an appropriate contact pressure.

E. Fixing speed The rotation speed (fixing speed) of the fixing film 10 is 5 to 3
It is preferably 00 mm / sec. When the fixing speed exceeds 300 [mm / sec], the fixing film 1
0 cannot be rotated stably, and the fixing film 1
0 is damaged, which is not preferable.

FIG. 13 shows a schematic configuration of an example of an electromagnetic induction heating type fixing device in which the alternating magnetic flux distribution of the exciting coil is concentrated on the fixing nip to improve the efficiency.

Reference numeral 10 denotes a cylindrical fixing film having an electromagnetic induction heating layer (a conductor layer, a magnetic layer, and a resistor layer) and serving as an electromagnetic induction heating rotating body.

Reference numeral 16 denotes a gutter-shaped film guide member having a substantially semicircular cross section. The cylindrical fixing film 10 is loosely fitted outside the film guide member 16.

Numeral 15 denotes a magnetic field generating means disposed inside the film guide member 16 and comprises an exciting coil 18 and an E-shaped magnetic core (core material) 17.

Numeral 30 denotes an elastic pressure roller, which forms a fixing nip portion N having a predetermined width with a predetermined pressing force on the lower surface of the film guide member 16 with the fixing film 10 interposed therebetween, and mutually pressed. The magnetic core 17 of the magnetic field generating means 15 is disposed so as to correspond to the fixing nip portion N.

The pressure roller 30 is driven to rotate by the driving means M in the direction shown by the arrow. A rotational force acts on the fixing film 10 due to a frictional force between the pressing roller 30 and the outer surface of the fixing film 10 due to the rotational driving of the pressing roller 30, and the fixing film 10 While being in close contact with the lower surface of the guide member 16, the film guide member 16 is rotated around the outer periphery of the film guide member 16 at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 30 in the direction indicated by the arrow (pressure roller drive system). ).

The film guide member 16 pressurizes the fixing nip portion, supports the exciting coil 18 and the magnetic core 17 as the magnetic field generating means 15, supports the fixing film 10, and transports the film 10 during rotation. Plays a role. The film guide member 16 is an insulating member that does not hinder the passage of magnetic flux, and is made of a material that can withstand a high load.

The excitation coil 18 generates an alternating magnetic flux by an alternating current supplied from an excitation circuit (not shown). The alternating magnetic flux is intensively distributed in the fixing nip N by the E-shaped magnetic core 17 corresponding to the position of the fixing nip N, and the alternating magnetic flux is applied to the electromagnetic induction heating layer of the fixing film 10 in the fixing nip N. Generates eddy currents. This eddy current generates Joule heat in the electromagnetic induction heating layer due to the specific resistance of the electromagnetic induction heating layer.

The electromagnetically induced heat of the fixing film 10 is intensively generated in the fixing nip N where the alternating magnetic flux is intensively distributed, and the fixing nip N is heated with high efficiency.

The temperature of the fixing nip N is controlled such that a predetermined temperature is maintained by controlling the current supply to the exciting coil 18 by a temperature control system including a temperature detecting means (not shown).

Thus, the pressure roller 30 is driven to rotate,
Accordingly, the cylindrical fixing film 10 rotates around the film guide member 16, and the power is supplied from the excitation circuit to the excitation coil 18 to generate the electromagnetic induction heat of the fixing film 10 as described above. The recording material P on which the unfixed toner image t is transported from the image forming unit (not shown) is fixed to the fixing film 10 in the fixing nip portion N and the pressure roller 30 in a state where the temperature is raised to the temperature of FIG. The image surface faces upward, that is, is introduced opposite to the fixing film surface, and at the fixing nip portion N, the image surface comes into close contact with the outer surface of the fixing film 10 so that the fixing film 10
Together with the fixing nip portion N. In the process of nipping and conveying the recording material P together with the fixing film 10 in the fixing nip N, the unfixed toner image t on the recording material P is heated and fixed by the electromagnetic induction heating of the fixing film 10. You. When the recording material P passes through the fixing nip portion N, it is separated from the outer surface of the rotary fixing film 10 and discharged and conveyed.

Next, the developing method usable in the present invention will be described below.

A developing method using a non-magnetic one-component developer will be described with reference to FIGS.

In FIG. 14, reference numeral 101 denotes a photosensitive drum serving as a latent image carrier. The photosensitive drum 101 rotates in a direction indicated by an arrow A in FIG. 103 forms an electrostatic latent image on the surface.

The electrostatic latent image is developed by the developing device 104 and visualized as a toner image.
Reference numeral 4 denotes a process cartridge which is disposed in proximity to the photosensitive drum 101 and is detachable from the image forming apparatus main body as a process cartridge. In this embodiment, so-called reversal development for forming a toner image on an exposed portion is performed.

The visualized toner image on the photosensitive drum 101 is transferred to a transfer material P as a recording medium by the transfer roller 106, and the transfer residual toner remaining on the photosensitive drum 101 without being transferred is scraped off by the cleaning blade 110. The photosensitive drum 101 stored and cleaned in the waste toner container 107 repeats the above operation to form an image.

On the other hand, the transfer material P on which the toner image has been transferred is subjected to a fixing process by the fixing device 100, discharged out of the device, and the printing operation is completed.

Next, the developing device 104 according to the present invention is described.
Will be described with reference to FIG.

In FIG. 15, reference numeral 114 denotes a developing container for containing the non-magnetic toner 108 as a one-component developer.
An opening extending in the longitudinal direction in the developing container 114 includes:
A developing sleeve 105 as a developer carrying member facing the photosensitive drum 101 is rotatably disposed, and a non-magnetic toner 108 carried on the developing sleeve 105 is provided.
As a result, the electrostatic latent image on the photoconductor 101 is developed and visualized.

The developing sleeve 105 is used for the developing container 11.
The right half peripheral surface shown in FIG.
, And is laterally provided with the left half peripheral surface exposed outside the developing container 114. The developing container 11 of the developing sleeve 105
The surface exposed to the outside 4 faces the photosensitive drum 101 located on the left side of the developing device 104 with a small gap. The developing sleeve 105 is driven to rotate in the direction of arrow B in FIG. 1, and has a surface with moderate unevenness. The unevenness increases the probability of the developing sleeve 105 sliding on the non-magnetic toner 108. At the same time, the conveyance of the non-magnetic toner 108 is favorably performed.

An elastic regulating blade 117 is provided above the developing sleeve 105 so as to be supported by the presser plate 115. The vicinity of the free end of the elastic regulating blade 117 is near the outer peripheral surface of the developing sleeve 105. Are in contact with each other. The elasticity regulating blade 117
Is a so-called counter (reverse) direction in which the leading end side with respect to the contact portion is located on the upstream side in the rotation direction of the developing sleeve 105. Further, the elastic blade 117 may have a conductive layer via a rubber elastic layer at a contact portion with the developing sleeve 105. In the present embodiment, the rubber elastic layer has a urethane having a rebound resilience of 20% or more. Rubber, silicone rubber, or the like is used, and a metal thin plate of SUS or phosphor bronze having spring elasticity is used as the conductive layer.

Further, in FIG. 15, reference numeral 116 denotes an elastic roller as a developer replenishing member.
Is in contact with the contact portion of the elastic regulating blade 117 with the surface of the developing sleeve 105 on the upstream side in the developing sleeve rotation direction, and is rotatably supported.

In the developing device 104 having the above configuration, the non-magnetic toner 10 in the developing container 114 during the developing operation is
8 is sent in the direction of the elastic roller 116 with the rotation of the stirring member 119 in the direction of arrow C.

[0200] The non-magnetic toner 108 is conveyed to the vicinity of the developing sleeve 105 by the rotation of the elastic roller 116 in the direction indicated by the arrow D in the drawing.
The elastic roller 11 at the contact portion between the
The non-magnetic toner 108 carried on the drum 6 is frictionally charged by being rubbed against the developing sleeve 105 and adheres to the developing sleeve 105.

Thereafter, the non-magnetic toner 108 is sent under pressure of the elastic regulating blade 117 with the rotation of the developing sleeve 105 in the direction of arrow B, where it receives an appropriate tribo (amount of triboelectric charging) and receives the toner on the developing sleeve 105. After being formed into a thin layer, the sheet is conveyed to a developing section opposite to the photosensitive drum 101 and subjected to development.

A developing method using a magnetic one-component developer will be described with reference to FIGS.

In FIG. 16, reference numeral 501 denotes an image bearing member (photosensitive member) around which a primary charging member 517 and a developing device 54 are arranged.
0, a transfer unit 514, a cleaner 516, and a registration roller 524. By applying a bias to the primary charging member 517 in contact with the image carrier 501, the electrostatic latent image carrier 501 is uniformly primary charged. Then, the laser beam 523 is emitted by the laser generator 521 to the image carrier 50.
An electrostatic latent image is formed by irradiating and exposing 1.

As shown in FIG. 17, a developing device 540 is provided near a toner carrier (developing sleeve) in which a coating layer is provided on a cylindrical substrate made of a nonmagnetic metal such as aluminum or stainless steel in the vicinity of the image carrier 501. ) 502 is provided, and the gap between the image carrier 501 and the toner carrier 502 is kept constant by a toner carrier / image carrier gap holding member (not shown) or the like. Further, a stirring rod 541 is provided in the developing device, and a magnet roller 504 having a plurality of magnetic poles is fixed concentrically with the toner carrier 502 in the developing sleeve.
The toner carrier 502 is rotatable. The magnet roller 504 is provided with a plurality of magnetic poles as shown in the figure, S1 affects development, N1 regulates the amount of toner, S2 influences toner take-in / conveyance, and N2 influences toner blowing prevention. A contact blade 503 is provided as a member for regulating the amount of magnetic toner attached to and transported on the toner carrier 502, and controls the amount of toner transported to the toner carrier 502. In the development area, the image carrier 5
A developing bias is applied between the image carrier 01 and the toner carrier 502, and the toner on the toner carrier flies on the image carrier 501 in accordance with the electrostatic latent image to become a visible image.

[0205]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention in any way.

Example 1 450 parts by mass of an aqueous 0.1 M Na ₃ PO ₄ solution was charged into 700 parts by mass of ion-exchanged water, heated to 50 ° C., and then heated with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). ) And stirred at 10,000 rpm. To this, 70 parts by mass of a 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing a calcium phosphate salt.

On the other hand, (monomer) styrene 170 parts by mass n-butyl acrylate 30 parts by mass (colorant) I. Pigment Blue 15: 3 17 parts by mass (charge control agent) Salicylic acid metal compound 2 parts by mass (polar resin) Saturated polyester 20 parts by mass (acid value 10 mgKOH / g, peak molecular weight; 15,000) (release agent) behenyl stearate 30 parts by mass (Maximum endothermic peak at the time of temperature rise measurement in DSC 72 ° C./maximum exothermic peak at the time of temperature decrease measurement 70 ° C.) (Crosslinking agent) 1.3 parts by mass of divinylbenzene The above formulation was heated to 60 ° C. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), the mixture was uniformly dissolved and dispersed at 10,000 rpm. Into this, 3.3 parts by mass of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

To the aqueous medium, 3 parts by mass of potassium persulfate as a water-soluble initiator was added, and the above polymerizable monomer composition was charged. The mixture was subjected to 8000 rpm with a TK homomixer at 50 ° C. under an N ₂ atmosphere. To granulate the polymerizable monomer composition.

Thereafter, while stirring with a paddle stirring blade, after 4 hours, the temperature was raised at a rate of 40 ° C./Hr. At 70 ° C. to react for 5 hours. After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to dissolve the calcium phosphate salt, followed by filtration, washing with water, and drying to obtain a weight average diameter of 6.0.
μm toner particles (1) were obtained.

A primary particle diameter of 12 subjected to hydrophobic treatment with silicone oil was added to 100 parts by mass of the toner particles (1).
1.0 parts by mass of dry silica having a thickness of nm and 0.2 parts by mass of hydrotalcite A (see Table 1: surface treatment with stearic acid, BET specific surface area 10 m ² / g, secondary particle size 4.5 μm). Thereafter, using a Henschel mixer manufactured by Mitsui Mining Co., Ltd., the mixture was uniformly stirred to obtain toner (1).

PE7700 manufactured by PerkinElmer, T
Using a GA7, the toner obtained at a heating rate of 10 ° C./min in a nitrogen atmosphere was examined for loss on heating up to 180 ° C., and it was 1.5%.

The obtained developer was subjected to image evaluation using an image forming apparatus as shown in FIGS. 14 and 15. The outline of the image forming apparatus will be described below.

In FIG. 14, reference numeral 101 denotes a photosensitive drum serving as a latent image carrier. The photosensitive drum 101 rotates in the direction of arrow A in FIG. 103 forms an electrostatic latent image on the surface.

The electrostatic latent image is developed by the developing device 104 and visualized as a toner image.
Reference numeral 4 denotes a process cartridge which is disposed in proximity to the photosensitive drum 101 and is detachable from the image forming apparatus main body as a process cartridge. In the present embodiment, so-called reversal development for forming a toner image on an exposed portion is performed.

The visualized toner image on the photosensitive drum 101 is transferred to a transfer material P as a recording medium by a transfer roller 106, and the transfer residual toner remaining on the photosensitive drum 101 without being transferred is scraped off by a cleaning blade 110. The photosensitive drum 101 stored and cleaned in the waste toner container 107 repeats the above operation to form an image.

On the other hand, the transfer material P on which the toner image has been transferred is subjected to a fixing process by the fixing device 100, discharged out of the device, and the printing operation is completed.

Next, the developing device 104 according to the present invention is described.
Will be described with reference to FIG.

In FIG. 15, reference numeral 114 denotes a developing container for containing the non-magnetic toner 108 as a one-component developer.
An opening extending in the longitudinal direction in the developing container 114 includes:
A developing sleeve 105 as a developer carrying member facing the photosensitive drum 101 is rotatably disposed, and a non-magnetic toner 108 carried on the developing sleeve 105 is provided.
As a result, the electrostatic latent image on the photoconductor 101 is developed and visualized.

[0219] The developing sleeve 105 is
The right half peripheral surface shown in FIG.
, And is laterally provided with the left half peripheral surface exposed outside the developing container 114. The developing container 11 of the developing sleeve 105
The surface exposed to the outside 4 is opposed to the photosensitive drum 101 located on the left side of the developing device 104 with a small gap. This developing sleeve 105 is indicated by an arrow B in FIG.
The developing sleeve 105 has a moderate unevenness, and the unevenness increases the probability of the developing sleeve 105 rubbing against the non-magnetic toner 108, and the conveying of the non-magnetic toner 108 is performed well. Will be

An elastic regulating blade 117 is provided above the developing sleeve 105 so as to be supported by the holding plate 115. The vicinity of the free end of the elastic regulating blade 117 is near the outer peripheral surface of the developing sleeve 105. Are in contact with each other. The direction in which the elastic regulating blade 117 abuts on the developing sleeve 105 is a so-called counter (reverse) direction in which the leading end side of the elastic regulating blade 117 is located upstream of the developing sleeve 105 in the rotation direction. Further, the elastic blade 117 has a conductive layer via a rubber elastic layer at least in a contact portion with the developing sleeve 105. In this embodiment, the rubber elastic layer has a rebound resilience of 20% or more of urethane rubber. SUS or phosphor bronze metal sheet having spring elasticity is used as the conductive layer.

Further, in FIG. 15, reference numeral 116 denotes an elastic roller as a developer supply member.
Is in contact with the contact portion of the elastic regulating blade 117 with the surface of the developing sleeve 105 on the upstream side in the developing sleeve rotation direction, and is rotatably supported.

In the developing device 104 having the above configuration, the non-magnetic toner 10 in the developing container 114 is
8 is sent in the direction of the elastic roller 116 with the rotation of the stirring member 119 in the direction of arrow C.

The non-magnetic toner 108 is conveyed to the vicinity of the developing sleeve 105 by the rotation of the elastic roller 116 in the direction indicated by the arrow D in the drawing.
The elastic roller 11 at the contact portion between the
The non-magnetic toner 108 carried on the drum 6 is frictionally charged by being rubbed against the developing sleeve 105 and adheres to the developing sleeve 105.

Thereafter, the non-magnetic toner 108 is sent under pressure of the elasticity regulating blade 117 with the rotation of the developing sleeve 105 in the direction of arrow B, where it receives an appropriate tribo (amount of frictional charge) and receives the non-magnetic toner 108 on the developing sleeve 105. After being formed into a thin layer, the sheet is conveyed to a developing section opposite to the photosensitive drum 101 and subjected to development.

The fixing device used in this embodiment will be described below.

FIG. 6 is a cross-sectional side view of a main part of the fixing device 100 of this embodiment, FIG. 7 is a frontal view of the main part, and FIG. 8 is a longitudinal front view of the main part. In the heat fixing device 100 of the present embodiment, a device in which the conventional oil application mechanism is omitted is used.

The magnetic field generating means includes the magnetic cores 17a, 17b,
17c and the exciting coil 18.

The magnetic cores 17a, 17b, 17c are made of ferrite. The excitation coil 18 is a coil (wire loop).
(Bundled wire) bundled with multiple copper thin wires, each of which is insulated and coated,
And the coil is wound a plurality of times to form an exciting coil. In this example, the exciting coil 18 is formed by winding eight turns. In this example, the exciting frequency of the exciting coil is set to 10
The alternating current was 0 kHz.

FIG. 12 is a schematic diagram of the layer structure of the fixing belt 10 in this embodiment. The fixing belt 10 of this embodiment includes a heat generating layer 1 made of a metal belt or the like serving as a base layer of the electromagnetic induction heat generating fixing belt 10, an elastic layer 2 laminated on the outer surface thereof, and a release layer 3 laminated on the outer surface thereof. Of a composite structure. In the fixing belt 10 having a substantially cylindrical shape, the heat generating layer 1 is on the inner surface side, and the release layer 3 is on the outer surface side. The diameter of the fixing belt was 50 mm.

The heating layer 1 of the fixing belt 10 has a thickness of 10 mm.
A μm nickel layer was used.

The elastic layer 2 was made of silicone rubber having a thickness of 100 μm and having a hardness of 35 degrees according to “JIS K-6301”.

The release layer 3 used was a fluororesin having a thickness of 20 μm.

The pressure roller 30 as a pressure member is composed of a core metal 30a, and a heat-resistant elastic fluoro rubber 30b formed concentrically and integrally around the core metal in the form of a roller. Pressing springs 25a and 25b are contracted between both ends of the rigid stay 22 and the spring receiving members 29a and 29b on the apparatus chassis side, respectively, so that a pressing stay 2 is formed.
A downward force is applied to 2. As a result, the lower surface of the belt guide member 16a and the upper surface of the pressure roller 30 are pressed against each other with the surface pressure of 125 kN / m ² with the fixing belt 10 interposed therebetween with the paper of 80 g / cm ² interposed therebetween, thereby forming the fixing nip N. It is 8.5 mm. The outer diameter of the pressing member was 35 mm.

According to the above-mentioned measuring method, 23 ° C., 60% R
Measurements of Z1, Z2, and Z3 of the fixing device in the environment of H showed the following. Z1 = 182 ° C Z2 = 165 ° C Z3 = 164 ° C

Using the image forming apparatus having the above-described configuration, a durability paper passing test was performed in an environment at a temperature of 10 ° C. and a humidity of 40% RH. The test method is described below.

Commercially available CLC paper A4 as a recording material
(Canon sales company, basis weight: 81.4 g / m ² ), and after continuously printing 4,000 sheets of all solid images at a fixing speed of 90 mm / sec, the temperature sensor 26 becomes 1
After showing 0 ° C., the evaluation machine was allowed to stand for 1 hour (operation I).

After standing for 1 hour, the fixing speed was again set to 90 mm
After printing all solid images continuously for 1,000 sheets at / sec, 1 hour after the temperature sensor 26 shows 10 ° C.
The evaluation machine was left still (operation II).

Thereafter, the operation II was repeated until the total number of prints reached 10,000, and image samples were obtained.

An image evaluation method is described below.

For the image evaluation, the image sample obtained in the operation II was used.

First, the image (4, 4) obtained in the first operation II
001-5,000th sheet), and count the number of white spots, that is, the places where the toner is not applied and the background color of the paper looks white in the entire solid image area. Classified by. (The number of blank areas in the total of 1,000 sheets) A: 0 B: 1 to 10 C: 11 to 50 D: 51 to 100 E: More than 100

The same evaluation was performed on the image samples obtained in each operation II.

Table 2 shows various physical properties of the toner, and Table 3 shows the evaluation results.

<Example 2> In place of hydrotalcite A used in Example 1, hydrotalcite B (see Table 1: surface treatment with stearic acid, BET specific surface area 7.5 m)
² / g, secondary particle size 6.5 μm) A toner (2) having various physical properties shown in Table 2 was obtained in the same manner as in Example 1 except that 0.06 parts by mass was externally added.

The loss on heating of the obtained toner up to 180 ° C. was found to be 1.4%.

Evaluation was performed in the same manner as in Example 1 using this toner (2). Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

Example 3 A four-necked flask was charged with 180 parts by mass of nitrogen-purged water and 20 parts by mass of a 0.2% by mass aqueous solution of polyvinyl alcohol.
Parts by mass, 25 parts by mass of n-butyl acrylate, 3.0 parts by mass of benzoyl peroxide, 0.1 part by mass of divinylbenzene.
2 parts by mass were added and stirred to form a suspension. Then, after the inside of the flask was replaced with nitrogen, the temperature was raised to 80 ° C.
The polymerization reaction was carried out for 0 hour. After washing the polymer with water, the polymer was dried under reduced pressure while maintaining the temperature at 65 ° C. to obtain a resin.

Example 1 88 parts by weight of the resin, 4 parts by weight of salicylic acid metal oxide, 10 parts by weight of copper phthalocyanine pigment
10 parts by mass of behenyl stearate used in the above were mixed by a fixed-tank type dry mixer, and melt kneading was performed by a twin-screw extruder while sucking by connecting a vent port to a suction pump.

This melt-kneaded product was crushed by a hammer mill to obtain a crushed toner composition of 1 mm mesh pass.
Further, the coarsely crushed product is crushed by a mechanical crusher to a volume average diameter of 20 to 30 μm, and then crushed by a jet mill utilizing collision between particles in a swirling flow. The toner composition was modified by mechanical and mechanical shearing force and classified by a multi-stage classifier to obtain toner particles (2) having a weight average diameter of 7.6 μm.

A primary particle size of 12 which was hydrophobized with silicone oil was added to 100 parts by mass of the toner particles (2).
After adding 1.0 part by mass of dry silica having a thickness of 1.0 nm and 0.9 parts by mass of hydrotalcite C (see Table 1, surface treatment with stearic acid, BET specific surface area 13 m ² / g, secondary particle size 3 μm), Using a Henschel mixer manufactured by Mitsui Mining Co., Ltd., the mixture was uniformly stirred to obtain toner (3).

When the weight loss of the obtained toner up to 180 ° C. was examined, it was 0.5%.

Evaluation was performed in the same manner as in Example 1 using this toner (3). Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

<Example 4> In place of hydrotalcite C used in Example 3, hydrotalcite D (see Table 1: Surface treatment with oleic acid, BET specific surface area 6 m ² /
g, secondary particle size 6.5 μm) A toner (4) having various physical properties shown in Table 2 was obtained in the same manner as in Example 3 except that 1.1 parts by mass was externally added.

The loss on heating of the obtained toner up to 180 ° C. was 0.5%.

Evaluation was performed in the same manner as in Example 1 using this toner (4). Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

<Comparative Example 1> In place of hydrotalcite A used in Example 1, hydrotalcite E (see Table 1: surface treatment with silicone oil, BET specific surface area 4.
5 m ² / g, secondary particle size 7.0 μm) Table 2 was prepared in the same manner as in Example 1 except that 0.01 part by mass was externally added.
As a result, a toner (5) having various physical properties shown in (1) was obtained.

The loss on heating of the obtained toner up to 180 ° C. was determined to be 1.5%.

Using this toner (5), evaluation was made in the same manner as in Example 1. Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

<Comparative Example 2> In place of hydrotalcite A used in Example 1, hydrotalcite F (see Table 1: no surface treatment, BET specific surface area: 4.5 m ² / g, secondary particle size: 7) 0.0 μm) A toner (6) having various physical properties shown in Table 2 was obtained in the same manner as in Example 1 except that 3.3 parts by mass was externally added.

The loss on heating of the obtained toner up to 180 ° C. was found to be 1.4%.

Evaluation was carried out in the same manner as in Example 1 using this toner (6). Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

Example 5 Hydrotalcite G (see Table 1: Surface treatment with stearic acid, BET specific surface area 4.4 m) was used in place of hydrotalcite A used in Example 1.
² / g, secondary particle size 6.8 μm) A toner (7) having various physical properties shown in Table 2 was obtained in the same manner as in Example 1 except that 0.2 parts by mass was externally added.

The loss on heating of the obtained toner up to 180 ° C. was determined to be 1.5%.

Evaluation was performed in the same manner as in Example 1 using this toner (7). Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

<Comparative Example 3> In place of hydrotalcite A used in Example 1, hydrotalcite H (see Table 1: lauric acid surface treatment, BET specific surface area 4.2 m ² /
g, secondary particle size 7.0 μm) A toner (8) having various physical properties shown in Table 2 was obtained in the same manner as in Example 1 except that 1.0 part by mass was externally added.

The loss on heating of the obtained toner to 180 ° C. was 1.5%.

Evaluation was performed in the same manner as in Example 1 using this toner (8). Table 2 shows various physical properties of the toner.
Table 3 shows the evaluation results.

Example 6 Styrene-butyl acrylate-divinylbenzene copolymer (glass transition point Tg = 65 ° C.) 100 parts by mass Magnetic material 80 parts by mass Iron complex of monoazo dye (negative charge control agent) 2 parts by weight ・ Low molecular weight polypropylene 4 parts by weight (Maximum endothermic peak at temperature rise measurement 107 ° C / Maximum exothermic peak at temperature fall measurement 104 ° C, Mw / Mn = 8.8)

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is coarsely pulverized with a hammer mill, the coarsely pulverized material is finely pulverized with a jet mill, and the obtained finely pulverized material is multi-divided using the Coanda effect. The toner particles (3) were obtained by classification using a mixer. The obtained toner particles (3) had a weight average particle size of 8.5 μm.
m.

In the same manner as in Example 1, 1.0 part by mass of dry silica having a primary particle diameter of 12 nm treated with a silicone oil was added to 100 parts by mass of the toner particles (3).
After adding 0.2 parts by mass of hydrotalcite A, the mixture was uniformly stirred using a Henschel mixer manufactured by Mitsui Mining Co., Ltd. to obtain toner (9).

The loss on heating of the obtained toner up to 180 ° C. was 0.1%.

The obtained developer was subjected to image evaluation using an image forming apparatus as shown in FIGS. The outline of the image forming apparatus will be described below.

(Production Example of Photosensitive Member) The photosensitive member has a diameter of 30.
mm cylinder was used as a substrate. Then, layers having the configuration shown in FIG. 18 were sequentially laminated by dip coating to prepare a photoreceptor. (1) Conductive coating layer: Mainly composed of tin oxide and titanium oxide powder dispersed in a phenol resin. 15μ thickness
m. (2) Undercoat layer: mainly composed of modified nylon and copolymerized nylon. The film thickness is 0.6 μm. (3) Charge generation layer: mainly composed of an azo pigment having absorption in a long wavelength region dispersed in butyral resin. Thickness 0.6
μm. (4) Charge transport layer: mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 according to the Oswald viscosity method) at a mass ratio of 8:10, and a polytetrafluoroethylene powder ( Particle size 0.2μ
m) was added in an amount of 10% by mass based on the total solid content, and the mixture was uniformly dispersed. 25 μm thick. The contact angle with water was 95 degrees.

The contact angle was measured using pure water, and the apparatus used was a contact angle meter CA-X, manufactured by Kyowa Interface Science Co., Ltd.

The image forming apparatus shown in FIG. 16 was used.

The organic photoconductor (OPC) drum of the above photoconductor production example was used as the image carrier, and the dark portion potential Vd = -600.
V, the light portion potential VL = −200 V. A gap between the photosensitive drum and the developing sleeve is set to 300 μm, and a resin layer having a layer thickness of about 7 μm and a JIS center line flatness roughness (Ra) of 1.3 μm as a toner carrier and a 20 mm diameter mirror surface having a mirror surface are provided. Using a developing sleeve formed on an aluminum cylinder, a developing magnetic pole is 95 mT (950 gauss), and a urethane rubber blade having a thickness of 1.0 mm and a free length of 10 mm is used as a toner regulating member at a surface pressure of 1.35 kN / m ^2. Contacted.・ Phenol resin 100 parts by mass ・ Graphite (particle size: about 7 μm) 90 parts by mass ・ Carbon black 10 parts by mass

Next, the DC bias component Vdc = −400 V as the developing bias, and the superimposed AC bias component V
pp = 1600 V and f = 2000 Hz were used. The peripheral speed of the developing sleeve is the peripheral speed of the photoconductor (80 mm / sec).
110% speed (88 mm /
sec).

The transfer roller 514 (made of ethylene-propylene rubber in which conductive carbon is dispersed, the volume resistance of the conductive elastic layer is 10 ⁸ Ωcm, the surface rubber hardness is 24 °, the diameter is 20 mm, and the contact pressure is 49 N / m) , Photoconductor peripheral speed (80
mm / sec) and the transfer bias is 16
μA.

The fixing device and the image evaluation method were the same as in Example 1. Table 2 shows various physical properties of the toner, and Table 3 shows the evaluation results.

<Example 7> In the same manner as in Example 6, except that 0.2 parts by mass of hydrotalcite B was externally added instead of hydrotalcite A used in Example 6, Table 2 was used. As a result, a toner (10) having various physical properties shown in (1) was obtained.

The loss on heating of the obtained toner up to 180 ° C. was 0.1%.

Evaluation was performed in the same manner as in Example 6 using this toner (10). Table 2 shows various physical properties of the toner, and Table 3 shows the evaluation results.

Example 8 Toner particles (1) of Example 1
The formulation of (Monomer) styrene monomer 170 parts by mass n-butyl acrylate 35 parts by mass (colorant) I. Solvent Yellow 17 13.5 parts by mass (charge control agent) salicylic acid metal compound 3.4 parts by mass (polar resin) Saturated polyester 20 parts by mass (acid value 10 mg KOH / g, peak molecular weight: 6,000) (release agent) behenyl Stearate 75 parts by mass (Maximum endothermic peak at the time of temperature rise measurement: 72 ° C./maximum exothermic peak at the time of temperature decrease measurement: 70 ° C.) (Crosslinking agent) Same as Example 6 except that 3.0 parts by mass of divinylbenzene is used. Thus, toner particles (4) having a weight average diameter of 6.0 μm were obtained.

With respect to 100 parts by mass of the toner particles (4), a primary particle diameter of 12 which was subjected to a hydrophobic treatment with silicone oil was used.
1.0 part by mass of dry silica having a thickness of 0.6 nm and 0.6 parts by mass of hydrotalcite A (see Table 1, surface treatment with stearic acid, BET specific surface area 10 m ² / g, secondary particle size 4.5 μm) were added. Thereafter, using a Henschel mixer manufactured by Mitsui Mining Co., Ltd., the mixture was uniformly stirred to obtain toner (11).

PE7700, manufactured by PerkinElmer, T
Using a GA7, the toner obtained at a heating rate of 10 ° C./min in a nitrogen atmosphere was examined for loss on heating up to 180 ° C., and found to be 3.3%.

Evaluation was performed in the same manner as in Example 1 using this toner (11). Table 2 shows various physical properties of the toner, and Table 3 shows the evaluation results.

Example 9 100 parts by mass of polyester resin (bisphenol A propylene oxide adduct / bisphenol A ethylene oxide adduct / terephthalic acid / trimellitic acid / dodecenyl succinic acid = 3.4 / 1.6 / 2.4) /0.6/2.0, Tg = 60 ° C.) 100 parts by mass of magnetic material (average particle size 0.22 μm, spherical) 2 parts by mass of iron complex of monoazo dye (negative charge control agent) 2 parts by mass of low molecular weight polypropylene 4 parts by mass (maximum endothermic peak at the time of temperature rise measurement 107 ° C / maximum exothermic peak at the time of temperature decrease measurement 104 ° C, Mw / Mn = 8.8)

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, and the cooled kneaded material was coarsely pulverized with a hammer mill, the coarsely pulverized material was finely pulverized with a mechanical pulverizer, and the obtained finely pulverized material was used for the Coanda effect. The toner particles (5) were obtained by classification using a multi-part classifier. The obtained toner particles (5) have a weight average particle size of 6.
It was 9 μm.

With respect to 100 parts by mass of the toner particles (5), a primary particle diameter of 12 which has been hydrophobized with silicone oil is used.
After adding 1.0 part by mass of dry silica having a thickness of 1.0 nm and 0.4 part by mass of hydrotalcite A, the mixture was uniformly stirred using a Henschel mixer manufactured by Mitsui Mining Co., Ltd. to obtain a toner (12).

PE7700 manufactured by PerkinElmer, T
When the toner obtained at a heating rate of 10 ° C./min in a nitrogen atmosphere under a nitrogen atmosphere using GA7 was examined for a loss on heating up to 180 ° C., it was 0.4%.

Using this toner (12), evaluation was made in the same manner as in Example 6. Table 2 shows various physical properties of the toner, and Table 3 shows the evaluation results.

Comparative Example 4 A toner (13) having various physical properties shown in Table 1 was obtained in the same manner as in Example 8 except that hydrotalcite A was not used.

Evaluation was performed using this toner (13) in the same manner as in Example 1. When the endurance evaluation of 4000 sheets was completed, image defects (white spots) were noticeably generated, and the image evaluation was stopped. .

Table 1 shows various physical properties of the toner, and Table 2 shows the evaluation results.

[0295]

[Table 1]

[0296]

[Table 2]

[0297]

[Table 3]

[0298]

As described above, by using the toner of the present invention,
Even when a fixing belt of the electromagnetic induction heating type is used in a low temperature environment, white spots on all solid images can be prevented, and good image quality can be stably obtained. Further, by using the image forming method of the present invention, downsizing of a machine, power saving, and on-demand printing can be performed while maintaining good image quality even in a low-temperature environment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fixing roller type fixing device.

FIG. 2 is a schematic diagram of a fixing belt type fixing device having a plurality of belt supports.

FIG. 3 is a schematic diagram of a fixing device of a fixing belt type having a single belt support.

4 is a diagram schematically showing a change in temperature at an arbitrary point A on the surface layer of the fixing roller shown in FIG.

5 is a diagram schematically showing a change in temperature at an arbitrary point A on the surface layer of the fixing belt shown in FIG. 6;

FIG. 6 is a schematic cross-sectional side view of a main part of a fixing device of an electromagnetic induction heating type according to the present invention.

FIG. 7 is a schematic front view of a main part of an electromagnetic induction heating type fixing device according to the present invention.

FIG. 8 is a longitudinal sectional front view of a main part of a fixing device of an electromagnetic induction heating type according to the present invention.

FIG. 9 is a schematic diagram of a magnetic field generating means according to the heating device of the present invention.

FIG. 10 is a diagram schematically showing a state of generation of an alternating magnetic flux.

FIG. 11 is a circuit diagram of a safety circuit according to the heating device of the present invention.

FIG. 12 is a schematic diagram illustrating a layer configuration of a fixing belt (fixing film) according to the heating device of the present invention.

FIG. 13 is a schematic configuration of an example of a fixing device of an electromagnetic induction heating system.

FIG. 14 is an explanatory diagram of a developing method using a non-magnetic one-component developer.

FIG. 15 is an explanatory diagram of a developing device.

FIG. 16 is an explanatory diagram of a developing method using a magnetic one-component developer.

FIG. 17 is an explanatory diagram of a developing device.

FIG. 18 is a schematic diagram illustrating a layer configuration of a photoreceptor used in an example.

FIG. 19 is an explanatory view exemplifying a measurement site of a surface temperature of a fixing belt (fixing film) according to the heating device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat generation layer 2 Elastic layer 3 Release layer 4 Heat insulation layer 10 Fixing belt 15 Magnetic field generation means 16, 16a, 16b Film (belt) guide member 16e Convex rib part 17, 17a, 17b, 17c Magnetic core 18 Excitation coil 18a, 18b Power supply unit 19 Insulating member (excitation coil holding member) 22 Rigid stay for pressurizing 23a, 23b Flange member 25a, 25b Pressurizing spring 26 Temperature sensor 27 Exciting circuit 29a, 29b Spring receiving member 30 Pressurizing roller (elastic) 30a Core bar 30b Elastic material layer 40 Good heat conducting member 50 Thermo switch 51 Relay switch 100 Image heating device (fixing device) 101 Photoconductor drum (electrostatic latent image carrier) 102 Charging device (charging roller) 103 Laser beam 104 Developing device 105 Developing sleeve (Toner Carrier) 106 Transfer Roller 108 Toner (developer)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 6/14 G03G 9/08 325 (72) Inventor Satoshi Handa 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Kiyowa Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term within Canon Inc. (reference) 2H005 AA01 AA08 CA03 CA30 CB10 EA03 EA07 FB01 2H033 AA01 BA11 BA12 BA25 BA30 BA58 BB18 BE03 BE06 CA04 CA07 CA30 CA48 3K059 AA08 AB28 AC33 AD03 AD07 AD32

Claims (54)

[Claims] 1. A recording medium comprising: (i) a magnetic field generating means; and (ii) a rotary heating member having at least a heat generating layer that generates heat by electromagnetic induction, and generates heat on a part of the rotary heating member in the rotation direction to form a recording material on the recording material. A toner image used in an image forming method for forming a fixed image by heat and pressure fixing the toner image of claim 1, wherein the toner contains at least a binder resin and a colorant, and is represented by the following general formula (1). A fine powder of a hydrotalcite compound is added externally. Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k is an integer of 2 or more, M1 ^2+, M2 ^2+, ... and Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, ^An-
Represents an n-valent anion, and m ≧ 0. ) 2. An image forming method comprising: (i) a magnetic field generating means; (ii) a rotary heating member having a heat generating layer which generates heat by electromagnetic induction; and a release layer, and (iii) a nip between the rotary heating means and the nip. An image forming method for forming a fixed image by heating and pressurizing a toner image on a recording material by using a heating and pressurizing unit having a rotating pressurizing member for forming a width, and heating and pressurizing a toner image on a recording material by heating a part of the rotating member in a rotation direction; And a temperature Z of the rotating member on the recording material entry side before and after a nip formed by the rotating heating member and the rotating pressing member.
1 (° C.), the temperature Z 2 (° C.) of the rotary heating member on the side where the recording material is discharged, and the temperature Z 3 (° C.) of the rotary heating member before reaching the portion where the rotary member generates heat. 2. The toner according to claim 1, wherein the image forming method satisfies Z3 ≦ Z2 <Z1. 3. The image forming method according to claim 1, wherein:
And (ii) heat is generated by electromagnetic induction and has a thickness of 1 to 200.
μm heat generating layer and a release layer having a thickness of 1 to 100 μm.
(Iii) the rotary heating member having at least
A nip having a width of 5.0 to 15.0 mm is formed with the heat member.
Heating and pressurizing means having at least a rotary pressurizing member
And apply a surface pressure of 9.0 k to the rotary heating member via a recording material.
N / m ^Two~ 500kN / m^TwoWhile pressing, the fixing speed
5 mm / sec to 300 mm / sec on the recording material
Heat and pressure fix toner image to form fixed image on recording material
3. An image forming method according to claim 1, wherein
The toner according to 1. 4. The toner according to claim 1, wherein the rotary heating member has an elastic layer. 5. The peripheral length La of the rotary heating member and the peripheral length Lb of the rotary pressing member satisfy the following condition: {0.4 × La} ≦ Lb ≦ {0.95 × La} <400
5. The toner according to claim 1, wherein the toner satisfies mm. 6. At least the heat generating layer generates heat in a range from a point of the recording material entry side La / 4 to a point of the recording material discharge side La / 8 with respect to a nip center with respect to a circumference La of the heating member. The toner according to any one of claims 1 to 5, wherein the toner is used. 7. A temperature Z1 of the rotating member on the recording material entry side.
The toner according to any one of claims 1 to 6, wherein (C) satisfies the following condition: Z1 <250C. 8. The hydrotalcite compound is represented by the following general formula (2).
The toner according to any one of the above. Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k are integers of 2 or more, M2, M3,.
L2, L3... and L different from each other selected from the group consisting of n, Ca, Ba, Ni, Sr, Cu and Fe.
k is a different metal selected from the group consisting of B, Ga, Fe, Co, and In, and ^An- represents an n-valent anion, and m ≧ 0. ) 9. In the general formula (2), y1> y2
+. + Yj is satisfied.
The toner according to 1. 10. In the general formula (2), x1> x
The toner according to claim 8, wherein a relationship of 2 + ... + xk is satisfied. 11. In the general formula (2), y1> y
The toner according to claim 8, wherein 2 + ... + yj and x1> x2 + ... + xk are satisfied. 12. In the general formula (2), y1> 1
The toner according to any one of claims 8 to 11, wherein the relationship 0x (y2 + ... + yj) is satisfied. 13. In the general formula (2), x1> 1
The toner according to any one of claims 8 to 11, wherein the relationship 0x (x2 + ... + xk) is satisfied. 14. In the general formula (2), y1> 1
0x (y2 + ... + yj) and x1> 10x (x2 + ... +
The toner according to any one of claims 8 to 11, wherein the relationship xk) is satisfied. 15. In the general formula (2), 0.9 ≦ 0.9.
15. The toner according to claim 8, wherein a relationship of x1 + y1 <1.0 is satisfied. 16. In the general formula (2), 0.93
15. The toner according to claim 8, wherein a relationship of 0 ≦ x1 + y1 ≦ 0.998 is satisfied. 17. In the general formula (2), 0.00
17. The toner according to claim 8, wherein a relationship of 1 ≦ y2 +... + Yj ≦ 0.05 is satisfied. 18. In the general formula (2), 0.00
18. The toner according to claim 8, wherein a relationship of 03 ≦ x2 +... + Xk ≦ 0.02 is satisfied. 19. The toner according to claim 1, wherein the hydrotalcite compound has been subjected to a hydrophobic treatment with a surface treating agent. 20. The binder resin contains polystyrene,
And a loss on heating of the toner up to 180 ° C. is 3.0% by mass.
The toner according to any one of claims 1 to 19, wherein: 21. The toner according to claim 1, wherein the toner has an endothermic peak measured by DSC (temperature rise measurement) at 20 to 200 ° C., and the maximum heat peak is located at 50 ° C. to 150 ° C. 20. The toner according to any one of 20. 22. The toner according to claim 1, wherein an exothermic peak of the toner by DSC (measurement of temperature drop) exists at 20 to 200 ° C., and a maximum heat peak thereof is located at 40 ° C. to 150 ° C. The toner according to any one of the above. 23. The hydrotalcite compound is represented by the following formula: The toner according to any one of claims 1 to 22, wherein: 24. The hydrotalcite compound is represented by the following formula: The toner according to any one of claims 1 to 22, wherein: 25. The hydrotalcite compound is represented by the following formula: The toner according to any one of claims 1 to 22, wherein: 26. The hydrotalcite compound is represented by the following formula: The toner according to any one of claims 1 to 22, wherein: 27. The hydrotalcite compound is represented by the following formula: The toner according to any one of claims 1 to 22, wherein: 28. A charging step of externally applying a voltage to a charging member to charge the electrostatic latent image carrier; a latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier; A developing step of developing the electrostatic latent image with the toner carried on the toner carrier and forming the toner image on the image carrier; transferring the toner image to a recording material with or without an intermediate transfer member Step: An image forming method including at least a fixing step of fixing a toner image on a recording material, wherein the fixing device comprises: (i) a magnetic field generating unit; and (ii) a rotary heating having at least a heat generating layer that generates heat by electromagnetic induction. A fixing device that generates a fixed image by heating and pressurizing and fixing a toner image on a recording material by heating a part of the rotation heating member in a rotation direction, and forming a fixed image. And a colorant, and Image forming method characterized in that fine powder of hydrotalcite compound represented by the following general formula (1) is externally added. Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k is an integer of 2 or more, M1 ^2+, M2 ^2+, ... and Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, ^An-
Represents an n-valent anion, and m ≧ 0. ) 29. A rotating heating member having (i) a magnetic field generating means, (ii) a heating layer that generates heat by electromagnetic induction, and a release layer; and (iii) a rotating heating member that forms a nip width with the rotating heating means. An image forming method for forming a fixed image by heating and pressurizing a toner image on a recording material by using a heating and pressing unit having a pressure member to generate heat in a part of the rotating member in a rotation direction. Before and after the nip formed by the heating member and the rotary pressing member, the temperature Z1 (° C.) of the rotating member on the recording material entry side and the temperature Z2 (° C.) of the rotary heating member on the side discharging the recording material. 29. The image forming method according to claim 28, wherein the temperature of the rotary heating member Z3 (° C.) before reaching the portion where the rotary member generates heat satisfies the following condition: Z3 ≦ Z2 <Z1. 30. A fixing device comprising: (i) a magnetic field generating unit;
And (ii) heat is generated by electromagnetic induction and has a thickness of 1 to 200.
μm heat generating layer and a release layer having a thickness of 1 to 100 μm.
(Iii) the rotary heating member having at least
A nip having a width of 5.0 to 15.0 mm is formed with the heat member.
Heating and pressurizing means having at least a rotary heating member
And apply a surface pressure of 9.0 k to the rotary heating member via a recording material.
N / m ^Two~ 500kN / m^TwoWhile pressing, the fixing speed
5 mm / sec to 300 mm / sec on the recording material
Heat and pressure fix toner image to form fixed image on recording material
30. A fixing device according to claim 28, wherein
2. The image forming method according to 1., 31. The image forming method according to claim 28, wherein said rotary heating member has an elastic layer. 32. The circumferential length La of the rotary heating member and the circumferential length Lb of the rotary pressing member satisfy the following condition: {0.4 × La} ≦ Lb ≦ {0.95 × La} <400
The image forming method according to any one of claims 28 to 31, wherein mm is satisfied. 33. At least the heat generating layer generates heat in a range from a point on the recording material entry side La / 4 to a point on the recording material discharge side La / 8 with respect to the nip center with respect to the circumference La of the heating member. 33. The method according to claim 28, wherein
The image forming method according to any one of the above. 34. A temperature Z of the rotating member on the recording material entry side.
The image forming method according to any one of claims 28 to 33, wherein 1 (° C) satisfies the following condition: Z1 <250 ° C. 35. The image forming method according to claim 28, wherein the hydrotalcite compound is represented by the following general formula (2). Embedded image (Where 0 <[X = (x1 + x2 +... + Xk)] ≦ 0.
5, Y = (y1 + y2 +... + Yj) = 1−X, j
And k are integers of 2 or more, M2, M3,.
L2, L3... and L different from each other selected from the group consisting of n, Ca, Ba, Ni, Sr, Cu and Fe.
k is a different metal selected from the group consisting of B, Ga, Fe, Co and In, and ^An- represents an n-valent anion, and m ≧ 0. ) 36. In the general formula (2), y1> y
The image forming method according to claim 35, wherein a relationship of 2 + ... + yj is satisfied. 37. In the general formula (2), x1> x
The image forming method according to claim 35, wherein a relationship of 2 + ... + xk is satisfied. 38. In the general formula (2), y1> y
36. The image forming method according to claim 35, wherein a relationship of 2 + ... + yj and x1> x2 + ... + xk is satisfied. 39. In the general formula (2), y1> 1
39. The image forming method according to claim 35, wherein a relationship of 0 × (y2 +... + Yj) is satisfied. 40. In the general formula (2), x1> 1
39. The image forming method according to claim 35, wherein a relationship of 0 × (x2 +... + Xk) is satisfied. 41. In the general formula (2), y1> 1
0x (x2 + ... + yj) and x1> 10x (x2 + ... +
The image forming method according to any one of claims 35 to 38, wherein the relationship xk) is satisfied. 42. In the general formula (2), 0.9 ≦
42. The image forming method according to claim 35, wherein a relationship of x1 + y1 <1.0 is satisfied. 43. In the general formula (2), 0.93
42. The image forming method according to claim 35, wherein a relationship of 0 ≦ x1 + y1 ≦ 0.998 is satisfied. 44. In the general formula (2), 0.00
44. The image forming method according to claim 35, wherein a relationship of 1 ≦ y2 +... + Yj ≦ 0.05 is satisfied. 45. In the general formula (2), 0.00
45. The image forming method according to claim 35, wherein a relationship of 03 ≦ x2 +... + Xk ≦ 0.02 is satisfied. 46. The image forming method according to claim 28, wherein the hydrotalcite compound has been subjected to a hydrophobic treatment with a surface treating agent. 47. The binder resin contains polystyrene,
And a loss on heating of the toner up to 180 ° C. is 3.0% by mass.
The image forming method according to any one of claims 28 to 46, wherein: 48. The toner according to claim 28, wherein the toner has an endothermic peak measured by DSC (temperature rise measurement) at 20 to 200 ° C., and the maximum heat peak thereof is located at 50 ° C. to 150 ° C. 47. The image forming method according to any one of items 47 to 47. 49. The toner according to claim 28, wherein an exothermic peak of the toner measured by DSC (measurement of temperature drop) exists at 20 to 200 ° C., and a maximum heat peak thereof is located at 40 ° C. to 150 ° C. The toner according to any one of the above. 50. The hydrotalcite compound is represented by the following formula: The image forming method according to any one of claims 28 to 49, wherein: 51. The hydrotalcite compound is represented by the following formula: The image forming method according to any one of claims 28 to 49, wherein: 52. The hydrotalcite compound is represented by the following formula: The image forming method according to any one of claims 28 to 49, wherein: 53. The hydrotalcite compound is represented by the following formula: The image forming method according to any one of claims 28 to 49, wherein: 54. The hydrotalcite compound is represented by the following formula: 50. The image forming method according to claim 28, wherein: