JPH0713385A - Toner for flash fixing and electrophotographic device - Google Patents

Abstract

PURPOSE:To provide a toner, which has an excellent flash fixing characteristic and high storage stability and hardly melts and adheres in a developing device, and to prevent a change of a toner characteristic due to an operating environment by controlling a melting point and a glass transition point of a binder resin used for the toner. CONSTITUTION:Amorphous polyamide is used for an essential constituent of a binder, and the polyamide includes a unit shown by a formula of 20 mole % in the principal chain. In the formula, Ar represents a divalent aromatic hydrocarbon radical or an aliphatic unsaturated hydrocarbon radical, while R<1> represents a hydrogen atom, a halogen atom, an alkyl group, or an amino group, and (m) shows 0 or 1. To Ar, a carbonyl group and an amino group are bound in the cis position, the ortho position, or the meta position. In other words, even a resin with a comparably low melting point shows a glass transition temperature considerably higher than a room temperature because amorphous polyamide is used, so that a toner with high heat stability can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used for developing an electrostatic latent image in electrophotography or the like.
More specifically, the present invention relates to an improvement in a toner for flash fixing which gives a fixed image having a particularly high fixing strength in a flash fixing method.

[0002]

2. Description of the Related Art Conventionally, US Pat. No. 2 has been used as an electrophotographic method.
The method described in No. 297691 is well known. This generally uses a photoconductive insulator (such as a photocondrum) to give a uniform electrostatic charge on the photoconductive insulator by corona discharge or the like, and the photoconductive insulator by various means. An electrostatic latent image is formed by irradiating a light image on the upper surface, then the latent image is developed and visualized by using fine powder called toner, and the toner image is transferred to paper or the like as necessary, and then added. A toner image is fixed on a recording medium such as paper by means of pressure, heating, solvent vapor, irradiation with light, etc. to obtain a copy.

As a toner for developing these electrostatic latent images, a toner in which a colorant such as a carbon block is dispersed in a binder resin made of a natural or synthetic polymer substance has been conventionally used, and the toner has a fineness of about 1 to 30 μm. Milled particles are used. Such a toner is usually used for developing an electrostatic latent image by mixing the toner alone or a carrier substance (carrier) such as iron powder or glass beads. When iron powder or other ferromagnetic particles are used as the carrier, the developer consisting of the toner and carrier is frictionally charged by being mixed and stirred in the developing device, and the magnet roll in the developing device is rotated to cause magnetic attraction. By forming a brush and rotating the magnet roll, the magnetic brush is carried to the latent image portion on the photoconductive insulator, and only the charged toner adheres to the latent image due to the electric attraction force to perform development. Be seen. After the development, a new toner is added to the developer whose toner concentration has decreased, and the toner is mixed and stirred in the developing device to maintain a constant toner concentration and is repeatedly used.

On the other hand, the toner powder image formed on the photosensitive drum is transferred onto a recording medium (for example, paper) by corona transfer, roller transfer or the like. The toner powder image transferred to the recording medium adheres to the paper in a powder state to form an image. For example, the image is distorted by rubbing with a finger.
In order to fix the toner powder image on the recording medium, it is necessary to melt the toner powder image and fix it on the recording medium, and there are various methods described above as the method. Among these methods, flash fixing, which is a typical method of optical fixing, is a method of fixing by flash light of a discharge tube such as a xenon flash lamp, and has the following features. Since it is non-contact fixing, the resolution of the image during development is not deteriorated. There is no waiting time after the power is turned on, and quick start is possible. Does not ignite even if the recording medium is jammed in the fixing device due to system down. It can be fixed regardless of the material and thickness of the recording medium, such as glued paper, preprinted paper, and paper of different thickness.

The process of fixing the toner to the recording medium by flash fixing is as follows. As described above, when the toner image is transferred to the recording medium, it adheres to the recording paper as powder to form an image. When a flash light of a discharge tube such as a xenon flash lamp is applied thereto, the toner absorbs the flash (light) energy, the temperature rises, the toner softens and melts, and the recording medium adheres and penetrates. After the flashing is finished, the temperature is lowered and solidified to form a fixed image, and the fixing is completed, and the fixed image fixed to the recording medium does not collapse even if it is rubbed with a finger or the like.

What is important in flash fixing is that the toner is melted and firmly adheres to the recording medium. Therefore, the toner absorbs light energy including heat energy that does not contribute to temperature rise by radiating to the outside. It must absorb from the flash of light and be sufficiently melted. The binder resin constituting the toner must be melted quickly in the process of fixing it on paper or the like, and must exhibit good fixability after it is cooled and solidified. To obtain such toner characteristics,
Low-molecular weight low-polymerization polymers having a low melting temperature and generally referred to as oligomers (for example, a number average molecular weight Mn of less than 1500 and a weight average molecular weight Mw of less than 10,000) are widely used.

As described above, one of the important characteristics of the flash fixing toner is that the toner needs to efficiently absorb the flash light and convert the light energy into heat energy. In order to obtain characteristics related to energy absorption and light energy / heat energy conversion,
A toner in which a material having a high degree of blackness, for example, carbon black or a dye is dispersed is widely used.

[0008]

As described above, low molecular weight oligomers are used as binders for flash fixing toners, but the oligomers have a low glass transition point.
For example, the storage stability of the toner is low, blocking is likely to occur in the developing machine, fusion is likely to occur in the developing machine, and a fused substance (coarse toner, etc.) is likely to occur, and the operating environment (temperature, humidity) of the device There is a problem that the characteristics of the toner are likely to change due to the change.

One of the reasons why such problems occur when low molecular weight oligomers are used is that when the molecular weight is lowered to lower the melting point of the binder, the glass transition point is lowered, and most of them are at room temperature. This is because Therefore, it shows good flash fixability,
In addition, as a means for solving the above-mentioned problems, it is necessary to optimize the melting point and glass transition point of the binder used for the toner, and a binder having a low melting point and a high glass transition point was used. Toner needs to be developed.

One of the objects of the present invention is to show excellent flash fixability by controlling the melting point and glass transition point of the binder resin used for the toner, and the storage stability of the toner is high. Flash fixing toner that does not easily cause blocking, does not easily fuse in the developing machine, does not easily generate fused substances (coarse toner, etc.), and its characteristics do not change due to changes in the operating environment (temperature, humidity) of the device. To provide.

Further, as described above, the material having a high degree of blackness, which is added to absorb the light energy and convert it into heat energy, has a great influence on the conductivity and the charging property of the toner, and is limited depending on the developing process. It can only be used at concentrations within the range. For example, a toner containing a dye and carbon in a two-component developing process using a magnetic carrier usually has a content of about 10 wt% or less, that is, a conductivity of 1 × 1.
It is 0 ⁻¹⁴ to 1 × 10 ⁻¹² S / cm. This is because as the content of carbon and dye, especially the content of carbon, increases, the background stain called "fogging" is more likely to occur.
This is because fog cannot be prevented in the region of conductivity of × 10 ⁻¹² S / cm or more even if the conditions of the development process are optimized.

The content of dye and carbon is, for example, 1
One of the reasons why such a problem occurs in a two-component developing process using a toner of more than 0 wt% is that the content of dye and carbon, especially the content of carbon is 10
This is because if the content exceeds wt%, the conductivity of the toner will be remarkably increased, and the toner having a high conductivity will be affected by the developing bias in the developing section and the charge amount will decrease. Therefore, the toner has high light energy absorption efficiency and high light energy / heat energy conversion efficiency.
In addition, as a means for solving the above-mentioned problems, it is necessary to develop a toner that does not cause fogging even when the toner charge amount becomes low due to the influence of the developing bias.

Another object of the present invention is to optimize the electric conductivity and magnetic susceptibility of the toner, and to control the melting point and glass transition point of the binder resin used for the toner, so that at least a two-component developing process and flash fixing can be performed. In an electrophotographic device that also has a process, it exhibits excellent flash fixing properties, high storage stability of toner, less blocking in the developing machine, and less likely to fuse in the developing machine. It is an object of the present invention to provide a flash fixing toner in which the characteristics of the toner are unlikely to change due to changes in the operating environment (temperature, humidity) of the apparatus.

[0014]

In order to achieve the above first object, the present invention uses an amorphous polyamide as an essential component of a binder, and the polyamide is selected from the following (a) and (b). Provided is a toner for flash fixing, which comprises at least 20 mol% in a main chain of at least one unit.

(A) Unit represented by the following structural formula:

[0016]

[Chemical 3]

(In the formula, Ar is a divalent aromatic hydrocarbon group having 20 or less carbon atoms or an aliphatic unsaturated hydrocarbon group, R ¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 3 carbon atoms, or An amino group, m is 0 or 1, and Ar
On the other hand, the carbonyl group or the amino group on both sides is bonded to the cis position, the ortho position or the meta position. ) (B) Unit represented by the following structural formula:

[0018]

[Chemical 4]

(Wherein R ¹ is as defined above, and R ^1
2 is an alkyl group having 1 to 4 carbon atoms, n is 0 or 1, q is 1, 2 or 3, and R ¹ and R ² are different groups in the same unit. ) Here, the unit containing a structure in which the carbonyl group or amino group of (a) is bonded to the cis position or the ortho position or the meta position via a double bond or a benzene ring is a repeating unit forming a polymer. It is a structure that inhibits the rotational movement of molecules between bonds, and is a structure that is not symmetrical in a straight line connecting two carbons bonded to a reactive group involved in polymerization, for example, an amino group or a carboxyl group. For example, in the case where a repeating unit forming a polymer contains a benzene ring as a structure that inhibits the rotational movement of the molecule between bonds, the amino group or carboxyl group involved in the polymerization is coordinated to the benzene ring in the ortho or meta position. The structure that does this corresponds to this. The unit (b) is an asymmetric structure having no center of symmetry in a repeating unit forming a polymer. For example, this corresponds to a structure forming a side chain or a structure in which an atom is introduced into a structure forming a main chain. The binder having such a repeating unit having no symmetrical structure in the molecule inhibits crystallization of the polymer and becomes an amorphous polymer.

By making the polymer amorphous,
Even when the melting point of the flash fixing toner (90 to 150 ° C.) is set, the glass transition point (5
5 ° C. or higher). For this reason, the toner using the amorphous polyamide can be melted in the fixing using the xenon flash lamp with much less fixing energy than the commercially available toner (for example, the toner for heat roll fixing).

When the toner is made to have such a low melting point by using a crystalline polymer, the glass transition point becomes about room temperature and the thermal stability is poor, so the storage stability of the toner is low, and blocking easily occurs in the developing machine. Fusing is easy in the developing machine, and fusing products (coarse toner, etc.) are easily generated.
Due to changes in the operating environment (temperature, humidity) of the apparatus, there arises a problem that the characteristics of the toner are likely to change. However, when the amorphous polyamide of the present invention is used, even a resin having a relatively low melting point exhibits a glass transition temperature which is considerably higher than room temperature, so that a toner having high thermal stability can be obtained.

The low melting point amorphous polyamide which can be used for such flash fixing is obtained by setting the number average molecular weight Mn to about 2000 to 5000 and the weight average molecular weight Mw to about 10,000 or more. The method for introducing an asymmetric structure into the polyamide main chain structure of the present invention can be achieved by using a specific monomer as the polyamide monomer. This specific monomer is a monomer which gives at least one kind of structure selected from the groups (a) and (b). Any one or more of the other monomers may be used provided that at least one of the polyamide monomers provides the asymmetric unit described above. Experience has shown that when a monomer that can introduce an aromatic ring into the main chain structure is used, the rigidity of the toner increases and the strength of the toner increases, which causes problems such as toner pulverization in the developing machine. Hard to do.

As an example of the monomer giving the unit (a),
Examples thereof include phthalic acid, isophthalic acid, phthalic anhydride, maleic acid, maleic anhydride, 1,2-di (methylamino) benzene, and 1,3-di (methylamino) benzene. Examples of the monomer that gives the unit (b) include, for example, methylsuccinic acid, β-methyladipic acid, 1,2-diaminopropane, 1,2-diaminobutane, 1,3-diaminobutane, and 2-methyl-2. , 4-diaminopentane and the like.

As mentioned above, at least one of the monomers that gives a specific structure to the main chain structure of the polymer is at least 2
It is necessary to contain 0 mol% or more, and when the content of the monomer is less than 20 mol%, a crystalline polymer is obtained, so that the polymer has a high melting point or a low glass transition point. However, when two or more kinds of the above-mentioned monomers are used in combination, it is not necessary that each of the combined monomers is 20 mol% or more,
The total amount of the monomers used in combination may be 20 mol% or more.

As the other comonomers that can be used in the amorphous low melting point polyamide used in the present invention, the monomers (diamine, dicarboxylic acid) used in ordinary polyamides can be used. Examples of the diamine component include, for example, ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, 1,4-dimethylaminobenzene,
and so on.

Examples of the dicarboxylic acid component include terephthalic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linoleic acid, mesaconic acid, citraconic acid,
Itaconic acid, glutaconic acid and the like and acid anhydrides thereof can be used. The above-mentioned amorphous low melting point polyamide can be used alone as a toner binder, but can also be used in combination with other binders if necessary. When used in combination with other binders, the binder to be blended can be blended with those conventionally used for toners, such as epoxy, styrene,
Styrene-acrylic resin, polyester, etc. can be used. However, when used with other binders,
The content of amorphous low melting point polyamide is 50% of the total amount of binder resin.
It should be more than weight%. This is because when the content is less than 50% by weight, the flash fixing property of the amorphous low melting point polyamide is lost.

In order to achieve the first object, the present invention contains an amorphous polymer as an essential component of a binder and a polymer showing rubber-like elasticity as a second polymer, or has a surface tension. Surface tension of 20 including reducing agent
It can also be achieved by a flash fixing toner characterized in that the temperature is set to 15 dyne / cm (Wilhelmy method) or less at 0 ° C.

The reason why the toner is preferable as the toner for flash fixing is that it is excellent in the following points. First, by using a polymer using the above-mentioned specific monomer as the constituent monomer of the polymer, it is possible to obtain a toner having a low melting point and a high glass transition point, which is suitable for flash fixing. That is, as described above, the amorphous polymer can be a polymer having a high glass transition point even if it has a relatively low melting point as compared with a crystalline polymer.

When the crystalline polymer has such a low melting point, the glass transition point becomes about room temperature and the thermal stability is poor.
Therefore, the storage stability of the toner is low, blocking is likely to occur in the developing machine, and fusion in the developing machine is easy.
Further, there are problems that a fused substance (coarse toner, etc.) is easily generated, and the characteristics of the toner are easily changed due to changes in the operating environment (temperature, humidity) of the apparatus.

Examples of the amorphous polymer include polyamides containing the above-mentioned specific units, phthalic acid, isophthalic acid, phthalic anhydride, maleic acid, maleic anhydride, methylsuccinic acid, and 1,2-propylene glycol, Polyester containing one or more kinds of monomers selected from the group of 1,2-butylene glycol and 1,3-butylene glycol as a constituent component in a total amount of 20 mol% or more can be used.

Whether the polymer is amorphous or crystalline depends on the content of the above-mentioned specific monomer. When the content of the monomer is 20 mol% or more, the polymer becomes amorphous, preferably 50 mol. It is effective to use a polymer of at least%. As described above, at least one of the monomers that gives a specific structure to the main chain structure of the polyester needs to be contained in an amount of at least 20 mol% or more.
When the amount is less than mol%, a crystalline polymer is obtained, so that the polymer has a high melting point or a low glass transition point. However, when two or more kinds of the above-mentioned monomers are used in combination, it is not necessary that each of the combined monomers is 20 mol% or more, and the total amount of the combined monomers may be 20 mol% or more.

As the other comonomers that can be used in the amorphous polymer used in the present invention, the monomers (dicarboxylic acid, diol, etc.) used in ordinary polymers can be used. Examples of the dicarboxylic acid component may include terephthalic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linoleic acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, and acid anhydrides thereof.

Examples of the diol component include ethylene glycol, 1,3-propylene glycol, trimethylene glycol, tetramethylene glycol and 1,4.
-Butylene glycol, pentamethylene glycol, hexamethylene glycol, hydroquinone, hydroquinone di- (β-hydroxyethyl) ether, 4-4 '
-Dihydroxybiphenyl, bis- (4-hydroxyphenyl) methane, bis- (4-hydroxyphenyl)
Diphenylmethane, bis- (4-hydroxyphenyl)
Ketone, bis- (4-hydroxyphenyl) ether, etc. can be used.

Further, the amorphous polyester which can be used for such flash fixing has a number average molecular weight Mn.
Of about 3,000 to 5,000 and the weight average molecular weight Mw of about 10,000 or more. The reason why the number average molecular weight is 3000 or more and the weight average molecular weight is 10,000 or more is that when the molecular weight is less than this, even an amorphous polymer has a too low glass transition point and lacks thermal stability. The reason why the number average molecular weight is 5,000 or less is that the flash fixing property is insufficient when the number average molecular weight is more than 5,000.

The above-mentioned amorphous low melting point polyester can be used alone as a toner binder, but can also be used in combination with other binders if necessary. When used in combination with other binders, the binder to be blended can be blended with those conventionally used for toner, and for example, epoxy, styrene, styrene-acrylic resin, polyamide, etc. can be used. . However, when used in combination with another binder, the content of the amorphous polyester is 50% by weight or more of the total amount of the binder resin. This is because if it is less than 50% by weight, the flash fixability of the amorphous low melting point polyester is lost.

Secondly, by using a surface tension reducing agent or a polymer showing rubber-like elasticity in combination, it is possible to prevent voids generated in a flash-fixed image. Since the above-mentioned binder is a polymer having a low molecular weight (Mn is 5000 or less) and not so large, a void is generated in a fixed image. In order to prevent this void, it is effective to increase the viscosity (elasticity) of the toner or suppress the surface tension to a low level.

Polymers exhibiting rubber elasticity include epoxy resin, styrene acrylic, polyester, vinyl resin,
Any polymer of polyamide resin and polybutadiene,
Examples thereof include a polybutadiene copolymer or a polybutadiene obtained by block copolymerizing a polymer containing a polybutadiene copolymer as a constituent unit. For example, 1,4 trans-polybutadiene, 1,4 cis-polybutadiene, 1,2-polybutadiene, butadiene-styrene copolymer, butadiene-methyl methacrylate copolymer, butadiene-methyl vinyl ketone copolymer, etc. are used. Main chain-modified epoxy, styrene-acrylic, polyester, and vinyl resins are available.

The molecular weight of the component exhibiting rubber-like elasticity and the amount of modification with respect to the main chain are arbitrary, but the weight average molecular weight (M
It is preferable that w) is 1000 to 5000, and the modification amount is 5 to 30 wt% with respect to the weight of the main chain constituent components. The reason why the molecular weight of the rubber component used for the modification is more preferably 1000 to 5000 is that the component exhibiting rubber elasticity to the main chain is introduced into the block to some extent to hinder the crystallinity after the main chain modification. Has a great effect, and
Molecular weight of several rubber-like components assembled as a modifier 100
This is because such a block copolymer can be obtained relatively easily by using about 0 to 5000 oligomers. The amount of modification is 5 to 30 wt% with respect to the weight of the main chain constituents.
The reason why it is more preferable is that if the modification amount is 5 wt% or less, the effect of increasing the melt viscosity at the time of melting the toner described in the present invention is difficult to appear, and if it is 30 wt% or more, the rubber-like component is introduced. This is because such a problem may occur, for example, the hardness of the copolymer after modification is lowered, and when this is used as a toner binder, it becomes difficult to finely pulverize after kneading the toner.

The surface tension reducing agent that can be used in the present invention is a polymer which is liquid or wax at room temperature, and is a low molecular weight dimethyl silicone polymer obtained by side chain modification with, for example, polyolefin (Mw 10,000 or less). When used, the effect is large, and the same effect can be obtained with a side chain modified type polymer of polyfluoroalkyl. When these materials are used, it is effective in preventing voids when the surface tension of the binder is approximately 15 dyn / cm or less.

The second object of the present invention is to contain carbon and a ferromagnetic material, have an electric conductivity of 1 × 10 ⁻¹² S / cm or more, and a saturation magnetization of 1 emu / g (10 kOe) or more, and more preferably a heat. It is achieved by a toner for flash fixing, which has a conductivity of 1 J / mKs or more. Here, as the essential constituent carbon, carbon black that is usually used for toner can be used.

The electric conductivity of the toner in which the carbon black is dispersed depends on the electric conductivity of the carbon black in which the toner is dispersed, but it is usually used for toners, for example, MA-100, MA-600. , # 33
When Mitsubishi Kasei Co., Ltd., Regal 400R, Black Pearls L (above, Cabot Co., Ltd.), etc. are used, the toner conductivity is 1 × 10 ⁻¹² S by containing approximately 10 wt% or more. / Cm or more can be achieved.

Such a toner having a high carbon black content is a conductive toner and also has a high efficiency of absorbing light energy of flash light during flash fixing. Furthermore, the thermal conductivity of carbon black is λ =
113 J / mks and binder λ = 0.1-0.3 J / mk
Since it has a higher value than s, the heat energy converted from the light energy on the toner surface can be efficiently transferred to the inside and bottom of the toner.

By using such a toner having a high light energy absorption efficiency and a high thermal conductivity, for example, in fixing using a xenon flash lamp, it is possible to fuse the toner with far less fixing energy than a commercially available toner. . However, as a toner for flash fixing, a conductive toner containing a large amount of carbon black as described above and a magnetic carrier, for example, ferrite,
When magnetite, iron powder, or the like is used in a two-component developing process, the electric resistance of the developer is too low and fogging occurs in the print background portion due to the influence of the developing bias. The most effective method for preventing fogging is to magnetize the toner. This is because the non-magnetic toner adheres to the carrier surface by electrostatic attraction and magnetic attraction, whereas the magnetic toner adheres to the carrier surface by electrostatic attraction. Therefore, at the time of development, even if the charge of the magnetic toner is lowered due to the influence of the developing bias, the toner is still attached to the carrier surface due to the magnetic attractive force, and the fog is not attached to the print background portion. Absent.

The ability to prevent fogging is determined by the magnetic susceptibility σs of the magnetic toner. In the case of the above conductive toner, the saturation magnetization s is 1 emu / g or more (10 kOs), preferably 5 e.
It is necessary to set mu / g or more. The magnetic property of the toner can be achieved by dispersing a ferromagnetic material such as flight powder, magnetite powder, or iron powder in the toner. To set the saturation magnetization of the toner to 1 emu / g or more, it depends on the saturation magnetization of the magnetic substance dispersed in the toner, but it is necessary to set it to 1 wt% or more.

Even when the magnetized conductive toner is used as described above, the binder resin constituting the toner is quickly melted in the process of fixing to the recording medium, and a good fixing property is obtained after it is cooled and solidified. Need to show. To achieve this object, for example, the present invention is preferably a toner in which an amorphous binder is used in combination as an essential constituent of a toner binder for flash fixing, and the pre-amorphous binder has (a) a number average molecular weight Mn of 2000 or more and 600
0 or less, (b) the weight average molecular weight Mw is 10,000 or more,
20,000 or less, (c) Flow tester softening temperature is 130
It is preferable to use a binder characterized in that the temperature is not higher than ° C.

By using such an amorphous polymer, the melting point (90 to 1) of the toner for flash fixing is usually used.
Even when the temperature is set to 50 ° C., the glass transition point (55 ° C. or higher) which is considerably higher than room temperature can be obtained. Therefore, the toner using the amorphous polyester can be melted in the fixing using the xenon flash lamp with a fixing energy much lower than that of the commercially available toner (for example, the toner for the heat roll fixing).

The above amorphous polymer can be used alone as a toner binder, but can also be used in combination with other binders if necessary. When used in combination with other binder, the binder to be blended can be blended with those conventionally used for toner, and for example, epoxy, styrene, styrene-acrylic resin, polyamide, etc. can be used. . However, when used in combination with another binder, the content of the amorphous polymer is set to 50% by weight or more of the total amount of the binder resin. 50% by weight
If it is less than 1, the excellent flash fixability of the amorphous polymer is lost.

The toner used in the present invention can be manufactured by a conventionally known method. That is, a binder resin, a colorant (carbon, dye), an inorganic filler, and, if necessary, a charge control agent, a conductivity control agent, a light absorber, a surface tension reducing agent, a viscosity adjusting agent, etc. For example, a pressure kneader, a roll mill, an extruder, and the like are melt-kneaded and uniformly dispersed,
Pulverize with a crusher, for example, jet mill,
A desired toner can be obtained by classifying with a classifier, for example, an air classifier.

FIG. 1 schematically shows a flash fixing type electrophotographic apparatus. The drum 1 on which the electrostatic latent image has been formed by the exposure 3 after the corona discharge to the photosensitive drum 1 made of a photosensitive insulator and the pre-charging 2 is performed by the developer 5 sent by the developing roller 4. It is developed. The developer 5 is agitating the carrier and toner by the agitating screw 6, and the supplying screw 7
Since the toner is frictionally charged by the time it is sent to the developing roller 4, the toner is electrostatically attracted to the electrostatic latent image on the photosensitive drum 1 for development. Since the toner density of the developer that uses toner for development decreases, the toner density sensor 8 monitors the toner density, and toner is replenished from the toner replenishment drum 9 as necessary.

The image-shaped toner 10 developed and adhered on the photosensitive drum 1 is transferred to the printing paper 12 by applying a reverse bias voltage 11, and then the printing paper 12 is sent to a fixing section, for example, a xenon lamp. When the toner is melted by the light irradiation from 13, cooled and attached to the printing paper, electrophotographic printing 1
4 is obtained, the flash fixing lamp is not limited to the xenon lamp, and any lamp can be used as long as the toner on the printing paper 12 is melted and fixed.

On the other hand, the photosensitive drum 1 which has completed the transfer returns to the pre-charging 2 through the cleaning 15.

[0052]

EXAMPLES In the following examples, various physical properties were measured by the following measuring methods. [Melting point] Melting point is flow tester (Shimadzu flow tester CFT
-500: Shimazu Seisakusho) was used to conduct a temperature rise flow test and the temperature was when the 4 mm plunger was lowered. The conditions of the temperature rising flow test are as follows.

Die 1 mm × 1 mm φ Temperature rising temperature 6 ° C./min Sample 1.5 g Pellet load 20 kgf Preheating temperature 60 ° C. Preheating time 300 seconds

[Glass Transition Point] The glass transition point was measured using a differential scanning calorimeter (DSC-20: Seiko Denshi). It was determined from the temperature rising endothermic curve at a temperature rising rate of 5 ° C./min.

[Electrical Conductivity] The electrical conductivity of the toner is measured by a dielectric loss measuring device (TR-10C, WBG-9, BDA-9, SE-).
43, TO-10: Ando Electric Co., Ltd.). The measurement conditions are as follows. Applied voltage 200 ℃ Electrode area 2.2cm ² Frequency 1000Hz Sample 0.07g (tablet molded under 500kg weight / cm ² )

[Saturation Magnetization] The saturation magnetization of the toner was measured using a vibrating sample magnetometer (VSM model PHV-55, Riken Denshi Co., Ltd.). About 0.2 g of toner was put in a sample capsule, the magnetic field strength was gradually increased, and the magnetic susceptibility at a strength of 10 kOe was measured. The magnetic susceptibility per unit weight was taken as the saturation magnetization (emu / g).

Example 1 Isodiphthalic acid in which ethylenediamine is used as a diamine and a structure in which a carbonyl group is bonded to a cis position, an ortho position or a meta position via a double bond or a benzene ring is used as a dicarboxylic acid component. Binders 1 to 5 were made by trial using phthalic acid, phthalic acid, maleic acid, and terephthalic acid having a structure bonded to the para position via a benzene ring (Table 1).
The binders 2 to 5 contain 20 mol% or more of a structure in which a carbonyl group is bonded to a cis position, an ortho position or a meta position via a double bond or a benzene ring. The obtained binders 2 to 4 were amorphous and had Tg 55 to 59 ° C. and Tm 12
It is 1 to 141 ° C. On the other hand, the binder 1 is crystalline and has a Tm of 145 ° C. but a Tg of 42 ° C.

Similarly, 1,2-di (methylamino) benzene, 1,3-di (methylamino) benzene and 1,4-di (methylamino) benzene are used as the diamine component to form a double bond or a benzene ring. Binders 5 to 6 having a structure in which an amino group is bonded to the cis position, the ortho position, or the meta position via A and a binder 7 to be bonded to para were experimentally produced (Table 2). The binders 5 to 6 are amorphous and have suitable Tg and Tm, but the binder 8 is crystalline and has unsuitable Tg and Tm.

From the above, Tm can be remarkably lowered by including a structure in which a carbonyl group or an amino group is bonded to a cis position, an ortho position or a meta position via a double bond or a benzene ring. It is clear that there is.

[Example 2] Ethylenediamine was used as the diamine, and methylsuccinic acid or β-methyladipic acid, which introduces an asymmetric organic group into the main chain structure, was used as the dicarboxylic acid component to introduce the binders 8-9 and the asymmetric organic group. Binder 10 was prototyped using succinic acid and terephthalic acid, which were not used (Table 3). The binders 8 to 9 are amorphous polymers and have Tg of 58 ° C and Tm of 58 to 61 ° C. On the other hand, the binder 10 is crystalline and has a Tg of 41 ° C.
It is m183 degreeC.

Similarly, 1,2-diaminopropane, 1,2-introducing an asymmetric organic group into the main chain structure as a diamine
Binders 11 to 1 using diaminobutane, 1,3-diaminobutane, and 2-methyl-2,4-diaminopentane
4 and 1,3-diaminopropane in which the asymmetric organic group was not introduced were used to fabricate a binder 15 (Table 4). The binders 11 to 14 are amorphous polymers and have a Tg of 58 to 65 ° C.
It is Tm121-125 degreeC. On the other hand, binder 1
5 is crystalline and has a Tg of 41 ° C but a Tm of 183 ° C.

From the above, it is apparent that Tm can be remarkably reduced by introducing an asymmetric organic group into the main chain structure.

[Example 3] From the above-mentioned investigation, there are monomers such as methylsuccinic acid and 1,3-di (methylamino) benzene which inhibit the crystallinity of the polymer, and amber which does not inhibit the crystallinity is amber. It is clear that there are acids, 1,4-di (methylamino) benzene and the like. These monomers were used to investigate the monomer ratios required to obtain amorphous polymers (Tables 5 and 6).

To obtain an amorphous polymer, the structure (a) is used.
Alternatively, it is apparent that (b) is contained in an amount of 20 mol% or more with respect to the entire main chain structure.

Example 4 Using the above amorphous polymer,
Prototype toners 1 to 20 with positive polarity were made, and flash fixability,
The blocking property and the charge stability were investigated. The toner composition is 90 parts by weight of binder resin, 5 parts by weight of nigrosine dye (Oil Black BY, Orient Chemical Co., Ltd.), and 5 parts by weight of carbon black (Black Pearls L, Cabot). Furthermore, using 5 parts by weight of the toner as a prototype and an irregular shaped iron powder carrier (TSV100-200, Powder Tech),
Used as a developer.

First, in order to evaluate the flash fixability, FACOM-6 adopting the flash fix method.
A 5 mm square solid image was printed using a 715D laser printer and a tape peeling test was conducted. At this time, the setting condition of the fixing device was a charging voltage of 2050 V using a capacitor having a capacity of 160 μF, and the voltage was applied to the flash lamp. Also,
The toner layer thickness of the solid image on the recording medium was about 15 μm. In the tape peeling test, an adhesive tape (Scotch Mending tape, Sumitomo 3M) was lightly applied to the solid image area, and an iron columnar block with a diameter of 100 mm and a thickness of 20 mm was brought into close contact with the recording medium on the tape at a constant speed in the circumferential direction. Then, the tape was peeled off from the recording medium.
As an index of the fixability, the quality of the fixability was judged from the magnitude of the ratio (percentage) of the optical image density (ID) before and after the tape was peeled off, and when the ratio was 80% or more, the fixability was evaluated as good. The optical image density was measured using a PCM meter (Macbeth).

The storage stability and blocking property of the toner are as follows.
2 hours from toner taken out after 12 hours exposure in RH environment
The toner of 00 mesh (75 μm) or less was removed, and the storage stability and blocking property were evaluated from the size of the weight of the remaining toner. The case where the remaining toner weight was 10 wt% or less was regarded as good.

The stability of the toner characteristics due to changes in the operating environment (temperature and humidity) of the apparatus is as follows: 10 g of the developer used in the evaluation of fixing property is packed in a 50 cc polybin, and a normal temperature and normal humidity environment (25
High temperature and high humidity environment (35 ° C, 80% R)
H) for 1 hour, then 1 hour in each environment
The developer taken out was stirred with a ball mill (200 rpm) for 0 minutes, and the charge amount of the taken-out developer was promptly measured. It was evaluated from the magnitude of the ratio (percentage) of the charge amount in the high temperature and high humidity environment to the charge amount in the normal temperature and normal humidity environment. This ratio is
The case of 70% or more was regarded as good.

The evaluation results are shown in Table 7. From the results, it is clear that the toner using the binder having a glass transition temperature of 55 ° C. or higher is excellent in blocking property and charge stability, and the toner having a melting point of 150 ° C. or lower is excellent in flash fixing property. Furthermore, the glass transition temperature is 55 ° C or higher and the melting point is 1
Toner 5,11,1 using amorphous polymer at 50 ° C or less
Nos. 2, 16, 19, and 20 are excellent in thermal stability, charging stability, and flash fixability.

[Example 5] Binder 8 and polyester (bisphenol A diethylene oxide-terephthalate polymer, Mw 12000, Tg 63 ° C, Tm 158)
Binder blend toners 21 to 25 were manufactured by using (.degree. C.). The amounts of the dye and carbon added were the same as in Example 4, and the same evaluation as in Example 4 was performed. If the proportion of polyester that does not have flash fixability increases, the flash fixability decreases, but the binder 8 is 5% of the total resin amount.
The toner containing 0 wt% or more has no problem in flash fixability.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4]

[0075]

[Table 5]

[0076]

[Table 6]

[0077]

[Table 7]

[0078]

[Table 8]

Example 6 As diol, ethylene glycol, bisphenol A type diethylene oxide,
1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol and neopentyl glycol are used, and terephthalic acid, isophthalic acid, as a dicarboxylic acid component,
Binders 31 to 41 were experimentally produced using phthalic acid, maleic acid, fumaric acid, succinic acid, and methylsuccinic acid (Table 9). The obtained binders 32 to 34 are amorphous and have T
It is g56-71 degreeC and Tm117-123 degreeC. On the other hand, the binder 31 is crystalline and has a Tg of 63 ° C. but a Tm of 131 ° C. and a high melting point.
Is crystalline and has a Tm of 118 ° C. but a Tg of 53 ° C. and a low glass transition point.

From the above results, phthalic acid, isophthalic acid, maleic acid, 1,2-propylene glycol,
It is clear that 1,2-butylene glycol and 1,3-butylene glycol are monomers that inhibit the crystallinity of polymers. Using the above polymer, a positive toner 31
~ 41 prototype, flash fixability, blocking ability,
The charge stability was investigated. Toner composition is binder resin 90
Parts by weight, 5 parts by weight of nigrosine dye (Oil Black BY, Orient Chemical Co., Ltd.), and 5 parts by weight of carbon black (Black Pearls L, Cabot). Furthermore, 5 parts by weight of the toner manufactured as a prototype and an irregular shaped iron powder carrier (TSV100
-200, Powder Tech) was used as the developer.

First, in order to evaluate the flash fixability, FACOM-6 adopting the flash fix method.
A 5 mm square solid image was printed using a 715 laser printer and a tape peeling test was conducted. At this time, the setting condition of the fixing device is to use a capacitor having a capacity of 160 μF and a charging voltage of 2
It was set to 050 V and applied to a flash lamp. The toner layer thickness of the solid image on the recording medium was about 15 μm.
For the tape peeling test, lightly apply an adhesive tape (Scotch Mending Tape, Sumitomo 3M) to the solid image area, and
An iron cylindrical block having a thickness of 0 mm and a thickness of 20 mm was rolled in a circumferential direction at a constant speed while being in close contact with the recording medium, and then the tape was peeled off from the recording medium. As an index of fixability, the optical image density (I
Whether the fixability was good or bad was judged from the size of the ratio (percentage) of D), and when the ratio was 80% or more, the fixability was good.
The optical image density was measured using a PCM meter (Macbeth).

The occurrence of voids in the fixed image was judged by visual evaluation. Further, regarding the storage stability and blocking property of the toner, 20 g of the toner was packed in a polybin and exposed to an environment of 55 ° C. and 30% RH for 12 hours, and the toner of 200 mesh (75 μm) or less was removed from the taken out toner and left. The storage stability and blocking property were evaluated from the size of the toner weight. Remaining toner weight is 1
The case of 0 wt% or less was regarded as good.

Regarding the stability of toner characteristics due to changes in the operating environment (temperature and humidity) of the apparatus, 10 g of the developer used in the evaluation of fixing property was packed in a 50 cc polybin, and the environment (25
High temperature and high humidity environment (35 ° C, 80% R)
H) for 1 hour, then 1 hour in each environment
The developer taken out was stirred with a ball mill (200 rpm) for 0 minutes, and the charge amount of the taken-out developer was promptly measured. It was evaluated from the magnitude of the ratio (percentage) of the charge amount in the high temperature and high humidity environment to the charge amount in the normal temperature and normal humidity environment. This ratio is 7
The case of 0% or more was regarded as good.

Table 10 shows the evaluation results. From the results, it is clear that the toner using the binder having a glass transition temperature of 55 ° C. or more is particularly excellent in blocking property and charging stability, and the toner having a melting point of 125 ° C. or less is particularly excellent in flash fixing property. However, in any toner having a glass transition temperature of 55 ° C. or higher and a melting point of 125 ° C. or lower, the occurrence of voids is remarkable in the fixed image.

[Example 7] Toners 42 to 45 were experimentally prepared by binder blending with a binder 34 and a polybutadiene-modified epoxy (bisphenol A type epoxy-polybutadiene copolymer, Mw 12000, Tm 118 ° C, polybutadiene modification amount 20 wt%). . The addition amounts of the dye and carbon were the same as in Example 6, and the same evaluation as in Example 6 was performed.

As can be seen from Table 11, when the proportion of the modified epoxy having no flash fixing property is increased, the flash fixing property is lowered, but the toner containing 50 wt% or more of the amorphous polymer with respect to the total amount of the resin is flashed. There is no problem with the fixability, and no void is seen in the fixed image with the toner having a modified epoxy content of 20 wt% or more.

[Embodiment 8] Toner 4 was prepared by using Binder 4 together with polydimethyl silicone (Mw 2500) whose side chain was modified with polyether as a surface tension reducing agent.
7-48 were made as prototypes. As can be seen from Table 12, no void is found in the fixed image with the toner having the surface tension reducing agent content of 0.1 wt% or more.

[Comparative Example 1] A small desk-top laser printer (M3) using a thermal roll fixing system with 5 parts by weight of toner 34 and 95 parts by weight of an irregular shaped iron powder carrier as a developer.
722, Fujitsu) was used to investigate the fixability and offset property. As shown in Table 12, excellent fixing properties are exhibited even at low temperatures, but the offset generation temperature is also low, and good fixing windows were not obtained.

[0089]

[Table 9]

[0090]

[Table 10]

[0091]

[Table 11]

[0092]

[Table 12]

[Example 9] Crystalline polyester A (Tm 138 ° C, Tg 51) composed of ethylene oxide of bisphenol A and terephthalic acid as a toner binder
(° C.), a conductive toner having a composition shown in Table 13 was experimentally manufactured. That is, a binder, a nigrosine dye (Oil Black BY: Orient Chemistry), and carbon (Black Pearls L: Cabot) having the composition shown in Table 13 were premixed and melt-kneaded with a pressure kneader at 140 ° C. for 30 minutes to form a toner mass. Obtained. The cooled toner lump was made into a coarsely pulverized toner having a particle size of about 2 mm by a Rotoplex pulverizer. Then
The coarsely pulverized toner was finely pulverized using a jet mill (PJM pulverizer: Nippon Numatic), and the pulverized product was classified by an air classifier (Apinel) to obtain conductive toners 51 to 55 of 5 to 20 μm.

It is clear that the electrical conductivity of the toner changes greatly depending on the carbon content, and that the electrical conductivity becomes remarkably high at 10 wt% or more. Further, the polyester A used in the toners 51 to 55 was similarly used as the toner binder, the compositions shown in Table 14 were used as the toners in the same manner as described above, and the magnetized toners 56 to 59 were experimentally manufactured. As the filler, magnetite (MTO-021 manufactured by Toda Kogyo) was used.

It is apparent that the saturation magnetization of the toner changes depending on the content of the magnetic substance, and the saturation magnetization of the toner increases as the content increases. 20 mol% of bisphenol A ethylene oxide as a toner binder,
Amorphous polyester B (Tm1 consisting of 30 mol% of 1,2-propylene glycol and 50 mol% of terephthalic acid)
21 ° C., Tg 63 ° C.) and a composition shown in Table 15 was used as a toner in the same manner as described above to prepare a conductive toner 60 as a prototype.

For each of the above toners 51 to 60, 5 parts by weight of toner and irregular iron powder (TSV100-20
0: Powder Tech) was used as a developer.
First, in order to evaluate the flash fixing property, a solid image of 5 mm square was printed using a FACOM-6715D laser printer adopting the flash fixing method, and a tape peeling test was conducted. At this time, the setting condition of the fixing device is capacity 1
Using a 60 μF capacitor, the charging voltage was set to 2050 V and applied to the flash lamp. The toner layer thickness of the solid image on the recording medium was about 15 μm. In the tape peeling test, an adhesive tape (Scotch Mending tape, Sumitomo 3M) was lightly applied to the solid image area, and an iron columnar block with a diameter of 100 mm and a thickness of 20 mm was brought into close contact with the recording medium on the tape at a constant speed in the circumferential direction. Then, the tape was peeled off from the recording medium. As an index of the fixability, the quality of the fixability was judged from the magnitude of the ratio (percentage) of the optical image density (ID) before and after the tape was peeled off, and when the ratio was 80% or more, the fixability was evaluated as good. The optical image density was measured using a PCM meter (Macbeth).

Further, the degree of toner fogging was judged from the magnitude of the optical image density of the printed background portion (white background portion), and a value of 0.1 or less was considered good. Regarding storage stability and blocking property of the toner, 20 g of the toner was packed in a polybin and exposed to an environment of 55 ° C. and 30% RH for 12 hours. The toner taken out was 200 mesh (75 μm).
The following toner was removed, and the storage stability and blocking property were evaluated from the size of the remaining toner weight. The case where the remaining toner weight was 10 wt% or less was regarded as good.

Regarding the stability of toner characteristics due to changes in the operating environment (temperature and humidity) of the apparatus, 10 g of the developer used in the evaluation of fixability was packed in a 50 cc polybin, and the environment (25
High temperature and high humidity environment (35 ° C, 80% R)
H) for 1 hour, then 1 hour in each environment
The developer taken out was stirred with a ball mill (200 rpm) for 0 minutes, and the charge amount of the taken-out developer was promptly measured. It was evaluated from the magnitude of the ratio (percentage) of the charge amount in the high temperature and high humidity environment to the charge amount in the normal temperature and normal humidity environment. This ratio is 7
The case of 0% or more was regarded as good.

Table 16 shows the evaluation results. From the results, a toner having a toner conductivity of 10 ⁻¹² S / cm or more (that is, a carbon content of 10 wt% or more) has excellent fixability but has a large fogging amount (Table 13). When a conductive toner having a large amount of fogging is magnetized, the amount of fogging becomes extremely small, and the occurrence of fogging can be suppressed by setting the saturation magnetization σs of the toner to 1 emu / g or more (Table 14). Furthermore, when an amorphous polymer is used as the binder of the toner, it is possible to obtain a toner having excellent flash fixing properties, blocking properties, and environmental characteristics.

The carrier having electric resistance of 1 × 10 ⁴ and 1 × 10 ⁶ Ωcm was used to prepare a developer having a toner concentration of 5 to 30 wt%, and the same evaluation as above was performed. The amount of fogging changes due to the carrier electric resistance, and when the carrier electric resistance is 1 × 10 ⁴ Ωcm, the occurrence of fogging cannot be suppressed. 1 more
Toner density of 3 even when using a carrier of × 10 ⁶ Ωcm
Fogging occurred at 0 wt%, but toner concentration was 20 wt%
Fogging did not occur below%.

[Comparative Example 2] A small tabletop laser printer (M3
722, Fujitsu) was used to investigate the fixability and offset property. As shown in Table 17, excellent fixing properties are exhibited even at low temperatures, but the offset generation temperature is also low, and good fixing windows were not obtained.

[0102]

[Table 13]

[0103]

[Table 14]

[0104]

[Table 15]

[0105]

[Table 16]

[0106]

[Table 17]

[0107]

According to the present invention, by controlling the melting point and glass transition point of the binder resin used for the toner, excellent flash fixability is exhibited, the storage stability of the toner is high, and blocking in the developing machine is achieved. A toner for flash fixing that does not easily cause fusing, does not easily fuse in the developing machine, does not easily generate fused substances (coarse toner, etc.), and its characteristics do not change due to changes in the operating environment (temperature, humidity) of the device. Provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a flash fixing type electrophotographic apparatus.

[Explanation of symbols]

 5 ... Developer 10 ... Toner 12 ... Printing paper 13 ... Xenon lamp

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Ken Ogino, 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa, within Fujitsu Limited (72) Inventor Takashi Yamamoto 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (15)

[Claims] 1. An amorphous polyamide is used as an essential component of a binder, and the polyamide has the following (a) and (b):
A toner for flash fixing, comprising at least 20 mol% in a main chain of at least one unit selected from the group consisting of: (A) Unit represented by the following structural formula: (In the formula, Ar is a divalent aromatic hydrocarbon group or an aliphatic unsaturated hydrocarbon group having 20 or less carbon atoms, R ¹ is a hydrogen atom,
It is a halogen atom, an alkyl group having 1 to 3 carbon atoms or an amino group, m is 0 or 1, and a carbonyl group or an amino group on both sides of Ar is bonded to a cis position, an ortho position or a meta position. ing. ) (B) Unit represented by the following structural formula: (In the formula, R ¹ is as defined above, R ² is an alkyl group having 1 to 4 carbon atoms, n is 0 or 1, and q is
Is 1, 2 or 3, and R ¹ and R ² are different groups in the same unit. ) 2. The unit (a) or (b) is phthalic acid, isophthalic acid, phthalic anhydride, maleic acid, maleic anhydride, 1,2-di (methylamino) benzene,
1,3-di (methylamino) benzene, methylsuccinic acid, β-methyladipic acid, 1,2-diaminopropane, 1,2-diaminobutane, 1,3-diaminobutane, 2-methyl-2,4-diamino The flash fixing toner according to claim 1, comprising one or more kinds of monomers selected from the group of pentanes. 3. A binder containing an essential component of a first polymer and a second polymer, the first polymer being an amorphous polymer, and the second polymer being an epoxy resin, styrene acryl, polyester, vinyl resin, polyamide. A toner for flash fixing, which is a polymer showing rubber elasticity obtained by block copolymerizing a polymer of any one of resins and polybutadiene or a polymer containing polybutadiene as a constituent unit. 4. A surface tension of 200 including an amorphous polymer as an essential component of a binder and a surface tension reducing agent.
A toner for flash fixing, which has a temperature of 15 dyne / cm (Wilhelmy method) or less at ℃. 5. The flash fixing toner according to claim 3, wherein the silicone polymer or the fluoroalkyl polymer is added in an amount of 0.1 to 2 wt% with respect to the total amount of the binder. 6. The flash fixing toner according to claim 3, 4 or 5, wherein the first polymer is the polymer according to claim 1 or 2. 7. The first polymer comprises phthalic acid, isophthalic acid, phthalic anhydride, maleic acid, maleic anhydride, methylsuccinic acid, and 1,2-propylene glycol, 1,2-butylene glycol, 1,3-. 7. The flash fixing toner according to claim 3, which is a polyester resin containing a total amount of 20 mol% or more as a constituent component of one or more kinds of monomers selected from the group of butylene glycol. 8. The flash fixing toner according to claim 1, wherein the melting temperature of the flow tester is 90 to 150 ° C. and the glass transition point is at least 55 ° C. or higher. 9. The number average molecular weight (M
9. The flash fixing toner according to claim 1, wherein n) is 2000 to 5000 and the weight average molecular weight (Mw) is 10,000 or more. 10. The toner for flash fixing according to claim 1, wherein the polyester is used in an amount of 50 wt% or more based on the total amount of binder resin used in the toner. 11. Containing carbon and a ferromagnetic material, having a conductivity of 1 × 10 ⁻¹² S / cm or more and a saturation magnetization of 1 emu / g (1
0 kOs ) The toner for flash fixing characterized by the above. 12. The flash fixing toner according to claim 11, which has a thermal conductivity of 1 J / mKs or more. 13. The toner for flash fixing according to claim 11, wherein a binder having a number average molecular weight (Mn) of 6000 or less, a peak molecular weight (Mp) of 20,000 or less and a flow tester softening temperature of 130 ° C. or less is used. 14. An electrical resistance of at least 1 × 10 ⁶ Ωcm
In the developer comprising the above magnetic carrier and toner, the flash fixing toner according to claim 9, 10 or 11 is used, and the toner concentration of the developer is 20 wt% or less. Developer. 15. An electrophotographic apparatus using a flash fixing device, wherein the toner or the developer according to any one of claims 1 to 14 is used.