JP2007034280A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which uses a highly durable fixing device having good bending fatigue resistance and wear resistance, allows fixing at low temperature, forms no abnormal image, and excels in durability. <P>SOLUTION: The image forming apparatus has a fixing section for fixing a toner image on a recording medium by heat and pressure. A toner forming the toner image contains at least a crystalline polyester resin and a noncrystalline resin substantially incompatible with each other in a binder resin, and inorganic fine particles having an average particle diameter of 5-1,000 nm have been incorporated into the toner. The fixing section has a fixing rotatory body and a pressure rotatory body, and a surface layer comprising a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a ratio of the number of oxygen atoms to the number of carbon atoms in a molecular chain being 1:60 or more has been formed on the peripheral surface of the fixing rotatory body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile using an electrophotographic process.

  Conventionally, as a fixing method used in the dry development method, a heating heat roller method is widely used because of its energy efficiency. In recent years, in order to save energy by fixing the toner at a low temperature, the thermal energy given to the toner during fixing tends to be small.

In terms of the low-temperature fixing of toner, an attempt has been made to use a polyester resin having excellent low-temperature fixability and relatively good heat-resistant storage, in place of styrene-acrylic resins that have been frequently used. However, for further low-temperature fixing, it is necessary to control the thermal characteristics of the resin itself. However, if the glass transition temperature (Tg) is lowered too much, the heat-resistant storage stability is deteriorated or the molecular weight is decreased. If the softening temperature [T (F _1/2 )] of the resin is lowered too much, there are problems such as lowering the hot offset occurrence temperature. For this reason, even a polyester resin excellent in low-temperature fixability has not yet obtained a toner having excellent low-temperature fixability and high hot offset occurrence temperature by controlling the thermal characteristics of the resin itself.

  In order to solve this problem, an attempt to add a specific non-olefinic crystalline polymer having a sharp melt property at a glass transition temperature in a binder resin (see Patent Document 1) or an attempt to use a crystalline polyester ( Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6).

  The toner production method is roughly divided into a pulverization method and a polymerization method. The pulverization method is a method of obtaining toner particles by melting and kneading the toner raw material and pulverizing and classifying, and the polymerization method is mixing the raw material and the resin monomer in the liquid. In this method, toner particles are obtained by polymerizing and granulating monomers.

  The problems specific to the toner in which the crystalline polyester is formulated by the pulverization method include the following problems derived from the crystalline structure and molecular structure of the crystalline polyester, and (1) the crystalline polyester has high hardness and is not brittle. The formulated toner has poor grindability, (2) The crystalline polyester has a low resistance due to the low resistance of the crystalline polyester, and (3) The glossiness of the fixed image changes depending on the fixing temperature. The higher the temperature is, the higher the image glossiness is. However, due to the sharp melt property of the crystalline polyester described above, the toner that formulated the crystalline polyester has a wide range of glossiness due to a change in the fixing temperature, and gloss unevenness is likely to occur. , Etc.

As a means for solving the problems (1) and (2), it is conceivable that a material that easily forms a pulverization interface in the toner and has excellent charging performance is included (internal addition). Inorganic fine particles with excellent charging performance, such as small silica, are considered as candidates. In addition, when inorganic fine particles are internally added to the raw material melted at the time of melt kneading, the inorganic fine particles exert a filler effect, and there is an effect that the raw materials such as crystalline polyester are uniformly finely dispersed. Charge uniformity is increased, and deterioration of image quality such as background stains derived from chargeability is prevented. There is Patent Document 7 as an attempt to internally add inorganic fine particles to a toner. This is a toner by a polymerization method, in which inorganic fine particles are present near the toner surface to obtain fluidity and charging performance.
For the problem (3), when inorganic fine particles are internally added to the toner, the inorganic fine particles damage the surface of the fixing roller and the fixing belt at the time of fixing and increase the surface roughness, thereby causing uneven gloss. .

  In recent years, with the development of digital copying machines, laser printers, and the like, there is a high demand for higher image quality. Particularly for printers, at present, a high image quality of 300 dpi is the mainstream, but it is expected that the image quality will be further improved to 480 dpi and 600 dpi in the future. Under such circumstances, it is inevitable that the use of a toner having a smaller particle size is required more severely. When the toner particle size is too small, it is necessary to increase the pulverization energy in the pulverization step, and there is a concern about the deterioration of productivity.

Regarding the above problem (2), in order to improve the charging performance of the crystalline polyester, an attempt to introduce a bisphenol A skeleton having a high charge retention capability (see Patent Document 8) has been made. It is considered that the crystallinity is lowered because skeletons of different sizes are introduced with respect to the skeleton of the component and the skeleton of the acid component.
Further, in the polymerization toner, the polyester prepolymer having a functional group containing a nitrogen atom as a component contributing to the polymerization reaction, and the toner produced by a polymerization method in which it is essential to contain the polyester, Since the base part has positive chargeability, the problem (2) originates from the functional group part containing a nitrogen atom as in the case where the crystalline polyester is contained.

In an electrophotographic apparatus, for example, an electrostatic latent image based on image information of an original image is formed on a photoconductor as an image carrier, the electrostatic latent image is converted into a toner image by a developing unit, and the toner image is used as a recording material. Is electrostatically transferred onto the paper. The sheet on which the toner image is transferred is sent to a fixing device, where the toner image is melted and fixed on the sheet by heat and pressure. As described in, for example, Patent Document 9, a belt-fixing type fixing device has a fixing belt stretched between a fixing roller and a heating roller having a heat source such as a halogen heater inside, and faces the fixing roller. The heating roller arranged in this manner is sandwiched between the fixing belt and pressed against the fixing roller. Fixing is performed by passing a sheet carrying a toner image through a nip formed between the fixing belt and the heating roller. By fixing by storing heat on a belt having a small heat capacity, the rise time is fast, and fixing at a low temperature is possible with a wide nip width.
In addition, a fixing belt having a three-layer structure including a base made of heat-resistant resin or metal, an elastic layer made of heat-resistant rubber or elastomer, and a release layer made of fluororesin has been proposed.

  In the fluororesin used for the release layer (surface layer) of such a fixing belt, since the belt is stretched around a plurality of rollers having a small curvature and rotated in a heated state, heat resistance and bending resistance are improved. Required. If there is no heat resistance and flex resistance, the durability may be deteriorated, for example, cracks may occur on the belt surface due to repeated use, and an abnormal image may appear in the fixed image. In addition, wear resistance is also required because of repeated rubbing with peripheral members such as paper, separation claw, temperature detection thermistor and the like. If there is no wear resistance, there may be a difference in height between the part that is repeatedly rubbed and the part that is not relatively rubbed, and an abnormal image is generated in the fixed image, and durability may not be obtained. is there.

Regarding improvement in durability of fluororesin, it is known to use a resin having a low melt flow rate (MFR) (high molecular weight) as described in Patent Document 10. However, those having a small MFR have low fluidity at the time of melting, and there is a problem that a desired smooth surface cannot be obtained when a release layer is coated and melted (fired) at a temperature equal to or higher than its melting point. . In that case, gloss unevenness occurs in the fixed image, and the image is deteriorated.
JP 62-63940 A JP 2003-167384 A Japanese Patent No. 2931899 JP 2001-222138 A JP 2004-221740 A JP 2004-279476 A WO2004 / 086149 Japanese Patent No. 3449995 JP 2002-268436 A JP 2003-167462 A

  In view of the above disadvantages, the present invention uses a highly durable fixing device having good bending fatigue resistance and wear resistance, can be fixed at a low temperature, has no abnormal image, and has excellent durability. An image forming apparatus is provided.

  As a result of examining the above problems, the inventors have determined that a toner having excellent low-temperature fixability by prescribing a crystalline polyester resin and an amorphous resin that are substantially incompatible with each other in a binder resin, In order to achieve a small particle size, it is possible to improve the pulverization property by adding inorganic fine particles to the toner and facilitate the reduction of the particle size. The present inventors have found that abnormal images such as background stains can be prevented by improving the toner charging performance without changing the skeleton and crystallinity of the toner. Furthermore, this toner is combined with a fixing unit employing a surface member of a novel fixing rotator (fixing roller / belt) to ensure wear resistance on the surface of the fixing member due to inorganic fine particles internally added to the toner, and crystallinity. High sensitivity to the glossiness of polyester, with high surface smoothness of the new fixing rotator, and high robustness to the fixing environment (fixing temperature fluctuations, unevenness of the surface of the fixing medium, etc.) I found out that it could be realized.

That is, this invention consists of the structure of following (1)-(6).
(1) An image forming apparatus having a fixing unit for fixing a toner image on a recording medium by heat and pressure, wherein the toner forming the toner image is a crystal that is substantially incompatible with at least a binder resin. A polyester resin having a property (crystalline polyester) and an amorphous resin, and inorganic fine particles having an average particle diameter of 5 to 1000 nm are internally added to the toner. A tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a pressure rotator and having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more on the outer peripheral surface of the fixing rotator. An image forming apparatus characterized in that a surface layer is formed.

(2) In the image forming apparatus according to (1), the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) has a melt flow rate (MFR) (JISK 7210, 372 ° C., 5 kgf load) of 3 ( An image forming apparatus comprising a mixture of a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) of not more than g / 10 minutes) and a PFA having an MFR of not less than 7 (g / 10 minutes).

(3) In the image forming apparatus according to (1) or (2), the surface layer of the fixing rotator has a PFA having an MFR of 3 (g / 10 minutes) or less and an MFR of 7 (g / 10). Min) After coating a dispersion mixed with the above PFA, the dispersion is fired.
Average particle diameter of PFA with MFR of 3 (g / 10 min) or less
An image forming apparatus characterized by satisfying the relationship of the average particle diameter of PFA having an MFR of 7 (g / 10 min) or more.

(4) The image forming apparatus according to any one of (1) to (3), wherein the toner for forming the toner image contains a polyester resin having crystallinity in a binder resin (crystalline polyester). An image forming apparatus having a ratio of 1 to 50% by weight and a crystalline polyester half flow-out temperature T (F _1/2 ) of 80 to 130 ° C.
(5) In the image forming apparatus according to any one of (1) to (4), the content of the inorganic fine particles added to the toner forming the toner image is 100 parts by weight of the toner. An image forming apparatus comprising 0.1 to 5 parts by weight.
(6) In the image forming apparatus according to any one of (1) to (5), the inorganic fine particles internally added to the toner forming the toner image are montmorillonite or a modified product thereof, silica, titanium oxide. An image forming apparatus characterized by being any one of alumina.
(7) In the image forming apparatus according to any one of (1) to (6), the toner includes an amorphous polyester prepolymer having at least a functional group containing a nitrogen atom, an amorphous polyester, An image characterized in that the toner is obtained by crosslinking and / or stretching reaction of a toner material liquid in which crystalline polyester, a colorant, a release agent, and inorganic fine particles are dispersed in an organic solvent in an aqueous medium. Forming equipment.
(8) A process cartridge used in the image forming apparatus according to any one of (1) to (7), selected from an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a cleaning unit. A process cartridge comprising at least one means integrated and detachably mounted.

  According to the present invention, a toner having excellent low-temperature fixability by formulating a crystalline polyester resin and an amorphous resin that are substantially incompatible with each other in a binder resin, and achieving high image quality In order to reduce the particle size, by adding inorganic fine particles to the toner, the pulverization property is improved and the diameter can be easily reduced, and at the same time, the charging performance of the toner is improved by the internal addition of inorganic fine particles. Abnormal images such as dirt can be prevented. Further, this toner has a novel fixing in which a surface layer made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a ratio of oxygen atoms / carbon atoms in the molecular chain of 1/60 or more is formed. By combining with a fixing unit that employs a rotating body (fixing roller / belt), the surface of the fixing rotating body is secured by the inorganic fine particles internally added to the toner, and the glossiness of the crystalline polyester is improved. With the high surface smoothness of the novel fixing rotator, it is possible to realize high robustness against the environment (fixing temperature fluctuation, unevenness of the fixing medium surface, etc.) with respect to the gloss of the image.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows a configuration of a four-tandem full-color printer as an image forming apparatus according to an embodiment of the present invention.
This printer has four sets of electrophotographic systems for forming four color toner images of yellow, magenta, cyan, and black on the surfaces of the corresponding photosensitive drums 1Y, 1M, 1C, and 1Bk (image carrier). Image forming units 10Y, 10M, 10C, and 10Bk (image forming means).

Below these image forming units 10Y, 10M, 10C, and 10Bk, a conveying belt 20 is stretched to convey a sheet (recording material) through each image forming unit.
The photosensitive drums 1Y, 1M, 1C, and 1Bk of the image forming units 10Y, 10M, 10C, and 10Bk are respectively arranged in contact with the conveyance belt 20, and the sheet (recording material) is electrostatically applied to the surface of the conveyance belt 20. Adsorbed.
The four sets of image forming units 10Y, 10M, 10C, and 10Bk have substantially the same structure. Therefore, here, the yellow image forming unit 10Y disposed on the most upstream side in the sheet conveyance direction will be described as a representative, and the other color image forming units 10M, 10C, and 10Bk are denoted by the same reference numerals. Detailed description is omitted.

  The image forming unit 10Y has a photosensitive drum 1Y that is in contact with the conveyance belt 20 at a substantially central position. Around the photosensitive drum 1Y, a charging device 2Y for charging the surface of the photosensitive drum 1Y to a predetermined potential, the charged drum surface is exposed based on the color-separated image signal, and the surface of the drum is electrostatically charged. An exposure device 3Y that forms a latent image, a developing device 4Y that supplies yellow toner to the electrostatic latent image formed on the drum surface and develops it, and a developed toner image on a sheet that is conveyed via the conveyance belt 20 A transfer roller 5Y (transfer device) for transferring, a cleaner 6Y for removing residual toner remaining on the drum surface without being transferred, and a charge eliminating lamp for removing electric charge remaining on the drum surface (not shown) are provided in the rotational direction of the photosensitive drum 1Y. Are disposed in order.

A paper feed mechanism 30 for feeding paper onto the transport belt 20 is disposed on the lower right side of the transport belt 20 in the drawing.
On the left side of the conveying belt 20 in the drawing, a fixing device 40 as a fixing unit according to an embodiment of the present invention, which will be described in detail later, is disposed. The paper transported by the transport belt 20 is transported through a transport path continuously extending from the transport belt 20 through the fixing device 40 and passes through the fixing device 40.
The fixing device 40 heats and pressurizes the conveyed paper, that is, the paper on which the toner images of the respective colors are transferred. Then, the toner images of the respective colors are melted and permeated into the paper to be fixed. In addition, the paper is discharged to the downstream side of the conveyance path of the fixing device 40 via a paper discharge roller.

Next, the fixing device 40 according to the embodiment of the present invention described above will be described in detail with reference to FIG.
The fixing device 40 includes a fixing roller 41 and a pressure roller 42 that are disposed in a positional relationship that sandwiches the sheet conveyance path vertically. The fixing roller 41 is formed by forming a heat-resistant sponge rubber layer on the outer periphery of a metal core. The sheet is conveyed at a constant speed on the conveyance path in a posture with the surface onto which the toner image is transferred facing up. The sheet is conveyed in a posture in which the front surface faces the fixing roller 41 and the back surface faces the pressure roller. In this embodiment, the pressure roller 42 is pressed upward in the figure by the spring 43, and the pressure roller 42 is pressed toward the fixing roller 41. However, since a pressing force is generated between the two, the fixing roller 42 is fixed. The roller 41 may be pressed toward the pressure roller 42.

  A rotational driving force is transmitted to the pressure roller 42 through a gear (not shown), and the fixing roller 41 is rotated in a driven manner. The fixing roller 41 may be rotationally driven. Alternatively, the pressure roller 42 and the fixing roller 41 may be meshed with each other so that both the pressure roller 42 and the fixing roller 41 are rotationally driven.

The fixing device 40 includes an endless fixing belt 45 that is a fixing rotating body stretched around a fixing roller 41 and a heating roller 44 containing a halogen lamp (heater) 46 inside a metal core. The structure of the fixing belt 45 will be described in detail later.
In this way, the fixing belt 45 stretched between the fixing roller 41 and the heating roller 44 travels endlessly in a state where the outer peripheral surface is in contact with the surface of the paper transported through the transport path. The outer peripheral surface of the pressure roller 42 is in contact with the back surface of the conveyed paper P. That is, the conveyed paper is pressurized by passing through the nip between the outer peripheral surface of the fixing belt 45 and the outer peripheral surface of the pressure roller 42.

A tension roller 47 is disposed in contact with the outer peripheral surface of the fixing belt 45 on the upstream side in the belt traveling direction from the nip with the pressure roller 42 and is pressed by the spring 48 in the left direction in the figure. Tension is applied to the belt by pressurizing the belt outer peripheral surface.
The thermistor 49 is disposed so that its detection end contacts the outer peripheral surface of the fixing belt 45. The thermistor 49 is brought into contact with the outer peripheral surface of the fixing belt 45 at a portion wound around the heating roller 44, thereby stabilizing the contact state between the two and preventing variation in temperature detection.

Next, the configuration of the fixing belt 45 will be described with reference to FIG.
An elastic layer 452 made of silicone rubber through a primer on the outer periphery of a cylindrical endless film substrate 451 made of a heat-resistant resin such as polyimide, and a release layer (surface layer) made of fluororesin through a primer on the outer periphery 453 is laminated.
The base 451 is required to have heat resistance and mechanical strength. For example, a metal such as Ni or SUS may be employed as the base film 451.
The elastic layer 452 may be made of a material that can uniformly apply heat and pressure to the toner and paper, can exhibit stable fixing performance, and has excellent heat insulation properties, and is not limited to silicone rubber.

The release layer 453 made of a fluororesin can be obtained by applying and firing a known fluororesin such as PTFE, PFA, FEP, or a blended material thereof onto the elastic layer 452 through a primer, but has a good durability. In order to obtain a belt, it is desirable to use PFA which is excellent in bending resistance, non-adhesiveness and abrasion resistance. In the present invention, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a ratio of the number of oxygen atoms (O) / carbon atoms (C) in the PFA molecular chain of 1/60 or more is used. That is, good bending resistance and wear resistance can be obtained with PFA having a high copolymerization ratio of perfluoroalkyl vinyl ether. This is because crystallization of PFA is suppressed when the copolymerization ratio of perfluoroalkyl vinyl ether is larger.
Similarly, the higher the copolymerization ratio of perfluoroalkyl vinyl ether, the better the surface smoothness can be obtained. Similarly, the effect of crystal size is less likely to affect the surface smoothness by suppressing the crystallization of PFA. Because.

  In addition, the melt flow rate (MFR) (JISK 7210, 372 ° C., 5 kgf load) is as small as 3 g / 10 min or less, that is, the use of PFA having a large molecular weight improves bending resistance and wear resistance. Therefore, the surface is not smooth and gloss unevenness occurs. In the present invention, a PFA of 3 g / 10 min or less with a small MFR contributing to bending resistance and wear resistance, and a PFA of 7 g / 10 min or more with a large fluidity contributing to surface smoothness, that is, a large MFR. Can be made compatible with durability and surface smoothness.

The surface layer of the fixing belt is obtained by coating and baking a dispersion in which PFA particles are dispersed in a liquid medium such as water. At the time of baking, a particle having a small particle size is used for leveling the surface. A big contribution,
MFR 3g / 10min or less PFA average particle size
> Smooth surface can be obtained by setting the average particle diameter of PFA having MFR of 7 g / 10 min or more.
In the present invention, the above particle size measurement was performed on a material diluted with a pure water as a dispersion medium so as to be 50 times the dispersion weight at a measurement temperature of 25 ° C. using a Horiba LB500. .

  As described above, the belt fixing device has been described as the fixing device. However, a roller type fixing device can also be used as the fixing device of the present invention. A fixing roller having a surface layer made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) having a ratio of the number of oxygen atoms (O) / carbon atoms (C) in the chain of 1/60 or more is used.

  In the image forming apparatus of the present invention, the electrophotographic photosensitive member and at least one means selected from a charging means, an exposure means, a developing means, and a cleaning means are integrated and mounted as a process cartridge that is detachable from the apparatus main body. May be.

(Toner prescription)
The polyester resin having crystallinity undergoes a crystal transition at the glass transition temperature (Tg), and at the same time, the melt viscosity suddenly decreases from the solid state and exhibits a fixing function to a recording medium such as paper. On the other hand, an amorphous resin usually used as a resin for toner gradually decreases in melt viscosity from Tg, and the temperature at which the melt viscosity decreases as Tg and a fixing function are expressed (for example, 1/2 outflow temperature (hereinafter referred to as softening temperature). Also, there is a difference of several tens of degrees C. from T (F _1/2 )). Therefore, in order to fix a toner using only an amorphous resin at low temperature, it is necessary to lower T (F _1/2 ) by lowering the resin Tg or lowering the molecular weight. As a result, the heat resistant storage stability and the hot offset resistance tend to be insufficient.
Therefore, by combining a crystalline polyester resin and an amorphous resin, low temperature fixing due to a decrease in melt viscosity without deteriorating heat-resistant storage stability and hot offset resistance, which was not possible with an amorphous resin alone. Can be achieved.

(Toner structure)
The content of the crystalline polyester resin that penetrates into the paper fiber that is the recording medium and melts the toner sufficiently to spread on the paper to obtain a high image density, and at the same time has excellent heat-resistant storage stability. In order to express the effect on the low-temperature fixability, 1% by weight or more is necessary with respect to the total amount of the binder resin. If this amount is large, the effect on fixing at low temperature is great, but if it is too large, the resin having crystallinity deteriorates the hot offset resistance. Therefore, it is preferably at most 50% by weight. More preferably, it is 40% by weight or less.

Since the resin having crystallinity rapidly decreases in melt viscosity at the glass transition temperature (Tg), the lower limit fixing temperature can be controlled not only by the content but also by Tg and T (F _1/2 ). It is. In this invention, it is preferable that it is low in the range which does not deteriorate heat-resistant storage stability, Tg of the polyester resin which has crystallinity is in the range of 80 to 130 ° C, and T (F _1/2 ) is in the range of 80 to 130 ° C. It is preferable. When Tg and T (F _1/2 ) are lower than the above ranges, it is difficult to synthesize a crystalline polyester having sharp melt properties and easily exhibiting an effect on low-temperature fixability. Since the minimum fixing temperature becomes high, the low temperature fixability cannot be obtained.

The toner of the present invention contains a crystalline polyester resin A and an amorphous resin B which are substantially incompatible with each other in the toner, and both are present in an incompatible phase-separated state in the toner. Therefore, it has excellent hot offset resistance and low-temperature fixability. That is, in the toner of the present invention, the crystalline polyester resin A and the amorphous resin B exist in a phase-separated state, so that the crystalline polyester resin A and the amorphous resin B have their respective characteristics. To express. That is, the amorphous resin B having a high T (F _1/2 ) increases the elasticity of the toner and improves the hot offset resistance, while the crystalline polyester A having a low T (F _1/2 ) has a low temperature. Improve fixability.

In the present invention, the crystalline polyester resin A and the amorphous resin B are substantially incompatible with each other because the crystalline structure portion of the crystalline polyester resin A remains in the toner and is in a phase separated state. It means to exist, and the compatibility means that no crystal structure part remains. Whether or not the crystalline polyester resin A and the non-crystalline resin B are present in a phase-separated state in the toner can be confirmed by any of the following methods.
(1) Whether or not a phase separation structure is formed can be confirmed by measuring an endothermic peak due to the first temperature increase in the DSC of the toner. In the DSC endothermic peak measurement, there are at least three endothermic peaks (A), (B), and (C) attributed to the non-crystalline resin B, the release agent, and the crystalline polyester resin A, respectively. Endothermic peak (A) having a peak top in the range of 40 to 70 ° C. and endothermic peak (B) attributed to the release agent having a peak top in the range of 70 to 90 ° C. The endothermic peak (C) attributed to the polyester resin A has a peak top in the range of 80 to 130 ° C.

(2) The presence or absence of the formation of a phase separation structure can be confirmed by X-ray diffraction pattern measurement using a toner powder X-ray diffractometer. This is because in the case of the toner of the present invention, the polyester resin A having crystallinity is present in the toner in a state of being phase-separated from the amorphous resin B while maintaining crystallinity. Diffraction peaks are present at least at 2θ = 20 ° to 25 °. When the phase separation structure is not formed, the crystalline structure of the crystalline polyester resin A is not maintained, and is compatible with the amorphous resin B, so that a diffraction peak attributed to the crystalline polyester resin A does not appear.

The measurement of the glass transition temperature (Tg) shown in the present specification is specifically determined by the following procedure. Using Shimadzu TA-60WS and DSC-60 as measuring devices, the measurement was performed under the following measurement conditions.
Measurement conditions Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50ml / min)
Temperature conditions Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C

  The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The analysis method is to specify a range of ± 5 ° C centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve, which is the DSC differential curve of the second temperature rise, and use the peak analysis function of the analysis software to determine the peak temperature. Ask. Next, the maximum endothermic temperature of the DSC curve is determined using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the Tg of the toner.

The softening temperature [T (F _1/2 )] here is the melting temperature in the _1/2 method, and the measurement method is as follows. Using an elevated flow tester CFT500 manufactured by Shimadzu Corporation, the flow curve of this flow tester is the data shown in FIG. 4, from which each temperature can be read. In FIG. 4, the melting temperature in the 1/2 method corresponds to [T (F _1/2 )] of the present invention.
"Measurement condition"
Load: 30 kg / cm ² , heating rate: 3.0 ° C./min, die diameter: 0.50 mm,
Die length: 1.0mm

  Since the toner of the present invention contains crystalline polyester, the volume resistivity value LogR tends to be lower than that of toner not containing crystalline polyester. This is a phenomenon derived from the fact that since the crystalline polyester has crystallinity, its volume resistivity is lower than that of an amorphous polyester resin. The LogR of the toner of the present invention is preferably 10.5 to 11.2 LogΩ · cm, and particularly preferably 10.7 to 11.15 LogΩ · cm. Since LogR becomes harder as the content of the crystalline polyester is lower or when a high kneading share is applied to the melt blending range, the LogR is adjusted by the content of the crystalline polyester and the kneading share at the time of melt kneading.

  When the LogR of the toner is smaller than 10.5 LogΩ · cm, the conductivity becomes high, thereby causing a charging failure, and there is a tendency to increase background contamination and toner scattering. In addition, an abnormal image is generated due to electrostatic offset or the like, and a high-quality image cannot be obtained stably. Further, when the LogR of the toner exceeds 11.2 LogΩ · cm, the resistance increases, and the charge amount increases and the image density tends to decrease.

The volume specific resistance LogR of the toner was measured as follows.
As a sample, 3 g of toner was pressed for 1 minute under a load of 6 t with an automatic pellet molding machine (Type M No. 50 BRP-E; manufactured by MAEKAWA TESTING MACHINE CO.) To produce 40 mmφ (thickness: about 2 mm) pellets.
This is set on SE-70 type solid electrode (manufactured by Ando Electric Co., Ltd.), and LogR when AC of 1 kHz is applied between the electrodes is TR-10C type dielectric loss measuring instrument, WBG-9. Measurement was made with a measuring instrument comprising an oscillator and a BDA-9 equilibrium point detector (both manufactured by Ando Electric Co., Ltd.), and the volume specific resistance value LogR of the toner was determined. RATIO is 1 × 10 ⁻⁹ . The measurement environment is room temperature 25 ° C. and humidity 50%.

(Crystalline polyester A)
The crystalline polyester resin A used in the present invention is characterized by comprising a crystalline aliphatic polyester resin containing an ester bond represented by the following general formula (1) in its molecular main chain.
_{-OOC-R-COO- (CH 2} ) n- (1)
In the above formula, R represents a linear unsaturated aliphatic divalent carboxylic acid residue, and is a linear unsaturated aliphatic group having 2 to 20 carbon atoms, preferably 2 to 4 carbon atoms. n is an integer of 2 to 20, preferably 2 to 6.
The existence of the structure of the general formula (1) can be confirmed by solid C ¹³ -NMR.

Specific examples of the linear unsaturated aliphatic group include linear unsaturated divalent carboxylic acids such as maleic acid, fumaric acid, 1,3-n-propene dicarboxylic acid, and 1,4-n-butene dicarboxylic acid. Mention may be made of linear unsaturated aliphatic groups derived from acids.
In the general formula (1), (CH ₂ ) n represents a linear aliphatic dihydric alcohol residue. Specific examples of the linear aliphatic dihydric alcohol residue in this case include linear aliphatic 2 such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol. Those derived from dihydric alcohols can be indicated. Since the polyester resin A uses a linear unsaturated aliphatic dicarboxylic acid as an acid component, the polyester resin A exhibits an effect that a crystal structure is easily formed as compared with the case where an aromatic dicarboxylic acid is used.

  Polyester resin A is a polyvalent carboxylic acid component comprising (i) a linear unsaturated aliphatic divalent carboxylic acid or a reactive derivative thereof (an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, an acid halide, etc.) And (ii) a polyhydric alcohol component comprising a linear aliphatic diol can be produced by a polycondensation reaction by a conventional method. In this case, a small amount of other polyvalent carboxylic acid can be added to the polyvalent carboxylic acid component as necessary. In this case, the polyvalent carboxylic acid includes (i) an unsaturated aliphatic divalent carboxylic acid having a branched chain, (ii) a saturated aliphatic divalent carboxylic acid, and a saturated aliphatic trivalent carboxylic acid. In addition to polyvalent carboxylic acids, (iii) aromatic polyvalent carboxylic acids such as aromatic divalent carboxylic acids and aromatic trivalent carboxylic acids are included. The addition amount of these polyvalent carboxylic acids is usually 30 mol% or less, preferably 10 mol% or less, based on the total carboxylic acid, and is appropriately added within the range where the resulting polyester has crystallinity.

  Specific examples of polyvalent carboxylic acids that can be added as needed include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. A divalent carboxylic acid of: trimetic anhydride, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, And trivalent or higher polyvalent carboxylic acids such as 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,2,7,8-octanetetracarboxylic acid, etc. it can.

A trivalent or higher polyhydric alcohol can be added to the polyhydric alcohol component, if necessary, in addition to a small amount of an aliphatic branched dihydric alcohol or cyclic dihydric alcohol. The addition amount is 30 mol% or less, preferably 10 mol% or less, based on the total alcohol, and is appropriately added within the range in which the resulting polyester has crystallinity.
Examples of polyhydric alcohol added as needed include 1,4-bis (hydroxymethyl) cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin and the like.

  In the crystalline polyester resin A, the molecular weight distribution is preferably sharp from the viewpoint of low-temperature fixability, and the molecular weight is preferably a relatively low molecular weight. The molecular weight of the polyester resin A is such that its weight average molecular weight (Mw) is 5000 to 8000, its number average molecular weight (Mn) is 1000 to 4000, and its Mw / It is preferable that Mn ratio is 2-5.

In the crystalline polyester resin A, the glass transition temperature (Tg) and the softening temperature [T (F _1/2 )] are desirably low as long as the heat-resistant storage stability of the toner is not deteriorated. Tg is 80 to 130 ° C., preferably 80 to 125 ° C., and T (F _1/2 ) is 80 to 130 ° C., preferably 80 to 125 ° C. When Tg and T (F _1/2 ) are higher than the above ranges, the lower limit fixing temperature of the toner is increased, so that the low temperature fixability of the toner is deteriorated.

Whether or not the resin fine particles in the present invention have crystallinity can be confirmed by whether or not a peak exists in the X-ray diffraction pattern by the powder X-ray diffractometer. In the diffraction pattern of the polyester resin A having crystallinity used in the present invention, at least one diffraction peak is present at a position where 2θ is 20 ° to 25 °, and preferably 2θ is at least (i) 19 Diffraction peaks are present at positions of ° to 20 °, (ii) 21 ° to 22 °, (iii) 23 ° to 25 °, and (iv) 29 ° to 31 °.
Powder X-ray diffraction measurement was carried out by using a Rigaku Electric RINT1100 with a powder sample placed on a slide glass, using a wide-angle goniometer under the conditions of a tube with Cu and a tube voltage-current of 50 kV-30 mA.

(Amorphous resin B)
The binder resin used in combination with the polyester resin A having crystallinity is an amorphous (non-crystalline) resin B, and all conventionally known resins can be used for this. For example, styrene, α-methylstyrene, chlorostyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, Styrene resins such as styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, polyester resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, There are epoxy resins, polyethylene resins, polypropylene resins, ionomer resins, polyurethane resins, silicone resins, ketone resins, xylene resins, petroleum resins, hydrogenated petroleum resins, and the like. Of these, styrene resins and polyester resins containing an aromatic compound as a component are preferred. Particularly preferred are polyester resins.

Amorphous polyester resin B is synthesized from a polyhydric alcohol and a polycarboxylic acid. As the polyhydric alcohol and polyhydric carboxylic acid, components used in the crystalline polyester resin A can be used, and besides these, there are alkylene oxide adducts of bisphenol A, isophthalic acid, terephthalic acid, and derivatives thereof.
These resins are not limited to single use but can be used in combination of two or more.

The molecular structure of the polyester resin B is not limited, but the alcohol component is at least one of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct, and the acid component has an unsaturated double bond between carbons. It is desirable to contain at least fumaric acid, maleic acid and derivatives thereof.
When the acid component of the crystalline polyester resin A and the polyester resin B has an unsaturated double bond between carbons, the unsaturated double bond between the carbons of the crystalline polyester resin A and the non-carbon are not present in the melt-kneading step in toner production. The unsaturated double bond between carbons of the crystalline polyester resin B interacts, and the crystalline polyester resin A and the amorphous polyester resin B are finely dispersed and mixed. This is because plasticization occurs partially at the interface between the domains of both resins.

  On the other hand, when either the crystalline polyester resin A or the amorphous polyester resin B has no unsaturated double bond between carbons, differential oxidation is not performed, and the offset (hot offset) of the polyester resin A domain is not performed. As a phenomenon) and polyester resin B domain offset (occurred as a cold offset phenomenon) is likely to occur.

The molecular weight of the polyester resin B used in the present invention is such that its weight average molecular weight (Mw) is 3000 to 100,000, its number average molecular weight (Mn) is 1500 to 4000, and its Mw / It is preferable that Mn ratio is 2-50.
The molecular weight distribution of the polyester resin B is based on a molecular weight distribution chart in which the horizontal axis is log (M: molecular weight) and the vertical axis is weight%. In the case of the polyester resin B used in the present invention, it is preferable to have a molecular weight peak in the range of 2.5 to 4.5 (% by weight) in this molecular weight distribution diagram.

The measurement method of molecular weight distribution is as follows. GPC-150C (manufactured by Waters) was used as an apparatus, the column was stabilized in a heat chamber at 40 ° C., and THF as a solvent was passed through the column at this temperature at a flow rate of 1 ml / min. The concentration is measured by injecting 0.1 ml.
The THF sample solution of the resin was prepared by stirring a THF solution having a resin concentration of 0.5% by weight with a ball mill at room temperature for 24 hours, and then filtering with a 0.2 μm hole diameter membrane filter manufactured by Toyo Filter Paper Co., Ltd. is there. Waters GPC-150C can be used as a measuring device, and Shodex KF801-807 can be used as a column. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Alternatively, the molecular weights manufactured by Toyo Soda Industry Co., Ltd. are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9. It is appropriate to use x10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

In the polyester resin B, the glass transition temperature (Tg) and the softening temperature [T (F _1/2 )] are desirably low as long as the heat-resistant storage stability of the toner is not deteriorated. It is 45-75 degreeC, Preferably it is 50-70 degreeC, The T (F1 _{/ 2} ) is 90-150 degreeC, Preferably it is 90-130 degreeC. When Tg and T (F _1/2 ) are higher than the above ranges, the lower limit fixing temperature of the toner is increased, so that the low temperature fixability of the toner is deteriorated.

(Release agent)
As the release agent used for the toner in the present invention, all known ones can be used, and in particular, the free fatty acid type carnauba wax, polyethylene wax, montan wax and oxidized rice wax can be used alone or in combination. . The carnauba wax is preferably a microcrystalline one, having an acid value of 5 or less and a particle size of 1 μm or less when dispersed in a toner binder. The montan wax generally refers to a montan wax refined from minerals, and like a carnauba wax, it is microcrystalline and preferably has an acid value of 5 to 14. The oxidized rice wax is obtained by air-oxidizing rice bran wax, and the acid value is preferably 10-30. The reason is that these waxes are finely dispersed in the toner binder resin of the present invention, so that it is easy to obtain a toner excellent in offset prevention, transferability and durability as described later. These waxes can be used alone or in combination of two or more.
As other mold release agents, any conventionally known mold release agents such as solid silicone wax, higher fatty acid higher alcohol, montan ester wax, polyethylene wax and polypropylene wax can be mixed and used.

  The Tg of the release agent used in the toner of the present invention is preferably 70 to 90 ° C. If it is less than 70 ° C., the heat-resistant storage stability of the toner is deteriorated, and if it exceeds 90 ° C., the releasability at a low temperature is not expressed, the cold offset resistance is deteriorated, and the paper is wound around the fixing machine. The amount of these release agents used is 1 to 20% by weight, preferably 3 to 10% by weight, based on the toner resin component. If it is less than 1% by weight, the effect of preventing offset is insufficient, and if it exceeds 20% by weight, transferability and durability are deteriorated.

(Coloring agent)
As the colorant used in the color toner of the present invention, known pigments and dyes capable of obtaining toners of yellow, magenta, cyan and black colors can be used.
Examples of yellow pigments include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, and Tartrazine Lake. Can be mentioned.

Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.
Examples of red pigments include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.

Examples of purple pigments include fast violet B and methyl violet lake.
Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and indanthrene blue BC.
Examples of the green pigment include chrome green, chromium oxide, pigment green B, and malachite green lake.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
These can use 1 type (s) or 2 or more types.

(CCA)
The color toner of the present invention can contain a charge control agent in the toner as needed.
For example, nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), basic dyes such as C.I. I. Basic Yellow 2 (C.I. 41000), C.I. I. Basic Yellow 3, C.I. I. Basic Red 1 (C.I. 45160), C.I. I. Basic Red 9 (C.I. 42500), C.I. I. Basic Violet 1 (C.I. 42535), C.I. I. Basic Violet 3 (C.I. 42555), C.I. I. Basic Violet 10 (C.I. 45170), C.I. I. Basic Violet 14 (C.I. 42510), C.I. I. Basic Blue 1 (C.I. 42025), C.I. I. Basic Blue 3 (C.I. 51005), C.I. I. Basic Blue 5 (C.I. 42140), C.I. I. Basic Blue 7 (C.I. 42595), C.I. I. Basic Blue 9 (C.I. 52015), C.I. I. Basic Blue 24 (C.I. 52030), C.I. I. Basic Blue 25 (C.I. 52025), C.I. I. Basic Blue 26 (C.I. 44045), C.I. I. Basic Green 1 (C.I. 42040), C.I. I. Basic Green 4 (C.I. 42000) and the like and lake pigments of these basic dyes, C.I. I. Solvent Black 8 (CI. 26150), quaternary ammonium salts such as benzoylmethyl hexadecyl ammonium chloride, decyl trimethyl chloride, or dialkyl tin compounds such as dibutyl or dioctyl, dialkyl tin borate compounds, guanidine derivatives, containing amino groups Polyamine resins such as vinyl polymers, condensation polymers containing amino groups, Japanese Patent Publication No. 41-20153, Japanese Patent Publication No. 43-27596, Japanese Patent Publication No. 44-6397, Japanese Patent Publication No. 45-26478 Metal complex salts of monoazo dyes described, Japanese Patent Publication No. 55-42752, Japanese Patent Publication No. 59-7385, salicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, Cr , Fe, etc. Metal complex, a copper phthalocyanine pigment obtained by sulfonation, organic boron salts, fluorine-containing quaternary ammonium salts, calixarene compounds, and the like. Naturally, color toners other than black should avoid the use of charge control agents that impair the target color, and white metal salts of salicylic acid derivatives are preferably used.

(Internally added inorganic fine particles)
In the present invention, in order to solve the low charge amount of the toner derived from the crystalline polyester resin having low resistance and few charge holding sites, the low pulverization property of the toner derived from poor pulverizability of the crystalline polyester, Inorganic fine particles are internally added to the toner.
The inorganic fine particles for internal use used in the present invention include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, montmorillonite, or organically modified products thereof. (Clayton APA, etc.), clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, In particular, silica, alumina, and titanium oxide are preferable.

In addition, inorganic fine particles containing a metal element (dope compound) as required for a silicon element forming a silicon compound such as silica as an element for forming inorganic fine particles can be more preferably used. As the metal element, elements such as Mg, Ca, Ba, Al, Ti, Ti, V, Sr, Zr, Zn, Ga, Ge, Cr, Mn, Fe, Co, Ni, and Cu can be used.
In addition, inorganic fine particles that have been surface-treated with a hydrophobizing agent may be used. Examples of the hydrophobic treatment agent include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, and the like. Further, sufficient effects can be obtained even when silicone oil is used as a hydrophobizing agent.

The dielectric constant of the inorganic fine particles is preferably 0.2 to 7.5, more preferably 1.3 to 3.5, and particularly preferably 1.7 to 2.5. By setting the dielectric constant of the inorganic fine particles within this range, the amount of accumulated charges can be maintained moderately, and abnormal charge increase in a low temperature and low humidity environment can be suppressed. This can provide stable image quality.
The dielectric constant of the inorganic fine particles used in the present invention is measured by placing the inorganic fine particles in a cylindrical cell having an inner diameter of 18 mm to which an electrode is attached, and pushing the inorganic fine particles in the cell into a disk shape having a thickness of 0.65 mm and a diameter of 18 mm. In a solidified state, measurement is performed with a TR-10C type dielectric loss measuring device (manufactured by Ando Electric Co., Ltd.). The frequency is 1 KHz and RATIO is 11 × 10 ⁻⁹ .

  It is preferable that the inorganic fine particles are melt-kneaded with a raw material such as a resin, a colorant, and a wax in the melt-kneading step and added internally. The amount of the inorganic fine particles added is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the toner. By setting it within this range, the grindability in the grinding step and the charging performance can be improved. If the amount is less than 0.1 part by weight, the content is insufficient, and the chargeability and grindability are not improved. If the amount exceeds 5 parts by weight, the inorganic fine particles are aggregated, and thus the inorganic fine particles cannot be uniformly dispersed. Is unevenly distributed on the surface of the toner and becomes a fixing inhibiting factor, and the minimum fixing temperature of the toner increases.

Moreover, the average diameter of the primary particle of inorganic fine particles is 5-1000 nm, More preferably, it is 5-500 nm. By setting it within this range, both improvement in chargeability and pulverization of the toner can be achieved. If it is less than 5 nm, the inorganic fine particles are aggregated, and the inorganic fine particles are not uniformly dispersed in the toner, and the charging uniformity is lost. If it is larger than 1000 nm, the chargeability and grindability are not improved. The average particle size here can be measured by directly obtaining the number average particle size from a photograph obtained by a transmission electron microscope. In this case, at least 100 particles are observed and the average value of the major axis is used. It is preferable.
These inorganic fine particles may be used alone or in combination of two or more.

(Externally added inorganic fine particles)
In the present invention, inorganic fine particles can be externally added to the toner. As the inorganic fine particles for external addition, the same inorganic fine particles for internal addition can be used.

(Toner particle size)
In view of the recent demand for higher image quality, the toner has a weight average particle diameter (D4) of preferably 3 to 8 μm, more preferably 4 to 7 μm, in order to reproduce minute dots of 600 dpi or more. In this range, since the toner particles have a sufficiently small particle size with respect to the minute latent image dots, the dot reproducibility is excellent.
When the weight average particle diameter (D4) is less than 3 μm, phenomena such as a decrease in transfer efficiency and a decrease in blade cleaning properties tend to occur.
When the weight average particle diameter (D4) exceeds 8 μm, it is difficult to suppress scattering of characters and lines.
The ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) is preferably in the range of 1.00 to 1.40, more preferably 1.05 to 1. 30.
The closer (D4 / D1) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

  In the full-color image forming method for forming a multicolor image by superimposing different color toner images, an image is formed with only one color of black toner, so that it is not necessary to superimpose different color toner images. The amount of toner deposited on the paper is large. In other words, since the amount of toner to be developed, transferred and fixed increases, the above-mentioned problems such as lower transfer efficiency, lower blade cleaning performance, scattering of characters and lines, background fogging, etc. are likely to occur. Management of the ratio (D4 / D1) of the diameter (D4) and the weight average particle diameter (D4) to the number average particle diameter (D1) is important.

Next, a method for measuring the particle size distribution of toner particles will be described.
As an apparatus for measuring the particle size distribution of toner particles by the Coulter counter method, there are Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using first grade sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the weight and number of toner particles or toner using a 100 μm aperture as an aperture. Calculate weight distribution and number distribution. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner can be obtained.

  As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

(Toner manufacturing method)
As a method for producing the toner of the present invention, a conventionally known method such as a melt kneading-pulverizing method or a polymerization method can be applied.
In the melt-kneading-pulverization method,
(1) Step of melt-kneading the binder resin and the inorganic fine particles (2) Step of pulverizing the melt-kneaded toner composition (3) Step of externally adding second inorganic fine particles (4) Predetermined It is preferable to have a classification step for obtaining a particle size and to perform the (4) classification step after the (3) external addition step in order to increase the fluidity of the particles and increase the classification accuracy and yield. Moreover, it is preferable from the viewpoint of cost that the fine powder to be replicated in the classification step is side-kneaded as a raw material of (1).

Moreover, the manufacturing method and raw material by a polymerization method are as follows.
Here, although a preferable manufacturing method is shown, it is not limited to this.
1) A colorant, a crystalline polyester, an amorphous polyester, a functional group containing a nitrogen atom, for example, an amorphous polyester prepolymer having an isocyanate group, a release agent, and inorganic fine particles are dispersed in an organic solvent to prepare a toner material liquid. create.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts thereof, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) par Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Further, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or tertiary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a fluoroalkyl group on the right is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) , Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), and Footgent F-300 (Neos Co., Ltd.).

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Rylic acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, Oxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.
Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

"Toner raw materials"
The toner obtained by the above polymerization method suitably used in the image forming apparatus of the present invention comprises at least an amorphous polyester prepolymer having a functional group containing a nitrogen atom, an amorphous polyester, a crystalline polyester, a colorant, a release agent. It is a toner obtained by crosslinking and / or extending a toner material liquid in which a mold agent and inorganic fine particles are dispersed in an organic solvent in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(Non-crystalline polyester)
The amorphous polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. As trihydric or higher polyhydric alcohol (TO), 3 to 8 or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.
The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated. The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).

  In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the gloss when used in the full-color image forming apparatus 100 are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.
The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition. The weight ratio of the unmodified polyester and the urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95. / 5, more preferably 75/25 to 95/5, particularly preferably 80/20 to 93/7. When the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.
In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

(Inorganic fine particles)
When the toner is produced by the polymerization method, the function of internally adding inorganic fine particles not only improves the charging performance but also forms irregularities on the toner surface, and the mechanism is as follows.
In a toner manufacturing method in which a toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles, the inorganic fine particles in the toner material liquid move to the interface between the organic solvent and the aqueous solvent during emulsification, and the emulsion dispersion Collect on the surface shape of the (reactant). Next, in the step of removing the organic solvent from the emulsified dispersion (reactant), washing and drying, the inorganic fine particles present on the surface form irregularities on the surface of the reaction product. Therefore, the amount of inorganic fine particles can be controlled in the range of 0.1 to 5 parts by weight, and the shape can be changed. The larger the amount of inorganic fine particles, the more inorganic fine particles present on the surface and the negative toner charge amount. As it becomes larger, the surface becomes uneven and deforms.

Hereinafter, the present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. Further, all parts in the toner developer prescription are parts by weight.
<Production of crystalline polyesters A1 to A3>
Polyesters A1 to A3 are composed of the composition shown in Table 1 (acid component, alcohol component) and hydroquinone having a total weight of 0.1% by weight, a thermometer, a stirrer, a condenser, and a nitrogen gas introduction pipe having a capacity of 5 L. In a four-necked round bottom flask, set the flask in a mantle heater, introduce nitrogen gas through a nitrogen gas inlet tube and keep the flask in an inert atmosphere, and keep the temperature at 160 ° C. For 5 hours and then at 200 ° C. for 1 hour, and then reacted at 8.3 kPa for 1 hour to obtain each polyester.

Table 1 shows the composition, and Table 2 shows the physical property values.

尚、結晶性の有りとは、粉末Ｘ線回折装置によるＸ線回折パターンにおいて、少なくとも２θ＝１９〜２０°、２１〜２２°、２３〜２５°、２９〜３１°の位置に回折ピークが現れたものである。推定分子式有りのものとは下記の固体Ｃ¹³−ＮＭＲにより一般式（１）の分子構造の存在が確認されたものである。

The presence of crystallinity means that a diffraction peak appears at least at positions of 2θ = 19 to 20 °, 21 to 22 °, 23 to 25 °, and 29 to 31 ° in an X-ray diffraction pattern by a powder X-ray diffractometer. It is a thing. And those there estimated molecular formula are those present in the molecular structure of the general formula (1) was confirmed by a solid C ¹³ -NMR below.

<Method for confirming molecular structure of resin>
Using solid C ¹³ -NMR (FT-NMR SYSTEM JNM-α400 manufactured by JEOL Ltd.), observation nucleus C ¹³ , reference material adamantane, integration number 8192 times, pulse series CPMAS, IRMOD: IRLEV, observation frequency 100.4 MHz, OBSET : 134500 Hz, POINT: 4096, PD: 7.0 sec, SPIN 6088 Hz, and molecular structure estimation is performed by Chem Draw Pro Ver. 4.5.

The molecular structure analysis of a solid C ¹³ -NMR as back wear measurements, in combination the following two measurements.
(A) A sample is measured by a Fourier transform infrared spectrophotometry (FT-IR) transmission method, and a structure is estimated from standard spectrum comparison.
Measuring machine: Nicolet Magna 850
Measuring range: 4000-400cm-1
Standard sample: KBr
(B) Thermal decomposable organism structure estimation using pyrolysis gas chromatogram mass spectrometer Measuring instrument: Shimadzu Corporation GC-17A, Shimadzu CR-4A
Thermal decomposition temperature: Nippon Analytical Industry JHB-3S
Thermal decomposition temperature: sample heating temperature × time is 590 ° C. × 4 seconds Column: DB-5 (J and W Co.) L = 30 m, I.V. D = 0.25 mm,
Film = 0.25mm
Column temperature: raised from 50 ° C. (holding time 1 minute) to 300 ° C. at 10 ° C./min Injection temperature: 320 ° C.
Carrier gas pressure: 150 kPa from 90 kPa (holding time 2 minutes) to 2 kPa / min
Step-up detector: FID

<Manufacture of polyester B>
Polyesters B-H1 and B-L1 were prepared by placing the composition shown in Table 5 (acid component, alcohol component) into a 5-liter four-necked round bottom flask equipped with a thermometer, stirrer and condenser. Was set in a mantle heater, 0.1% by weight of dibutyltin oxide of the total composition was added, the temperature was raised, the temperature was kept at 220 ° C. and reacted for 8 hours, and then the predetermined softening point was reached at 8.3 kPa. Each polyester was made to react until it reached.
Table 3 shows components, and Table 4 shows physical property values.
BPA / EO shown in Table 3 represents an ethylene oxide adduct of bisphenol A (2.2 mol adduct), and BPA / PO represents a propylene oxide adduct of bisphenol A (2.2 mol adduct). Indicates.

尚、結晶性のなしとは、粉末Ｘ線回折装置によるＸ線回折パターンにおいて、少なくとも２θ＝１９〜２０°、２１〜２２°、２３〜２５°、２９〜３１°の位置に回折ピークが現れないものである。

Note that “non-crystalline” means that a diffraction peak appears at least at 2θ = 19 to 20 °, 21 to 22 °, 23 to 25 °, and 29 to 31 ° in an X-ray diffraction pattern by a powder X-ray diffractometer. There is nothing.

<Toner developer>
<Toner Production Example 1>
Crystalline polyester resin A1 10 parts Amorphous polyester resin B-H1 65 parts Amorphous polyester resin B-L1 20 parts Salicylic acid Zr salt (Hodogaya Chemical TN-105) 1 part Desorbed free fatty acid type carnauba wax (Tg: 83 5 parts Carbon black (Mitsubishi Chemical # 44) 10 parts Hydrophobic silica C1 (average primary particle size 10 nm) 1 part Production Example 1 Toner air classification fine powder 15 parts

The above toner constituent materials were mixed in a Henschel mixer and then melt-kneaded in a twin screw extruder. Regarding the kneading conditions, as a result of setting the temperature of the kneader to knead the kneaded material at a low temperature (minimum temperature within the range where the kneaded material is in a molten state), the kneading material is mixed at the kneader outlet. The temperature of the kneader was set so that the temperature of the smelted product was 120 ° C.
Next, this kneaded product was coarsely pulverized to a particle size of 1 mm or less using an AP pulperizer manufactured by Hosokawa Micron Corporation, and then finely pulverized using IDS-2 manufactured by Nippon Pneumatic Industry. Silica C1 is added to and mixed with 100 parts of a finely pulverized product with 1.0 part Henschel mixer, and the mixture is classified with 132MP manufactured by Alpine, an air classifier, and a toner having a weight average particle diameter (D4) of 6.0 μm. The toner air classification fine powder of the above-mentioned prescription obtained as a base is a fine powder separated and collected at this time. 100 parts of the obtained toner base, 0.5 part of hydrophobic silica C1 and 0.5 part of titanium oxide D1 (average primary particle size 21 nm) were added and mixed with a Henschel mixer to obtain a final toner.
The presence or absence of the formation of a phase separation structure of the crystalline polyester resin and the amorphous resin was examined by measuring the X-ray diffraction pattern of the obtained toner. As a result, the diffraction peak attributed to the crystalline polyester resin was at least 19 to 20 °. It exists in the position of 21-22 degrees, 23-25 degrees, 29-31 degrees, and has confirmed having formed the phase-separation structure.

<Toner Production Example 2>
In toner production example 1, 10 parts of crystalline polyester resin A1 was changed to 40 parts of crystalline polyester resin A2, and 1 part of hydrophobic silica C1 was changed to 5 parts of hydrophobic silica C2 (average primary particle size 400 nm). Example 1 Toner as in Toner Production Example 1 except that 15 parts of toner air classification fine powder was changed to 15 parts of Production Example 2 toner air classification fine powder and D4 of the toner base obtained by classification was changed to 6.1 μm. Was made.
The presence or absence of the formation of a phase separation structure of the crystalline polyester resin and the amorphous resin was examined by measuring the X-ray diffraction pattern of the obtained toner. As a result, the diffraction peak attributed to the crystalline polyester resin was at least 19 to 20 °. It exists in the position of 21-22 degrees, 23-25 degrees, 29-31 degrees, and has confirmed having formed the phase-separation structure.

<Toner Production Example 3>
In Toner Production Example 1, 10 parts of crystalline polyester resin A1 was changed to 20 parts of crystalline polyester resin A3, and 1 part of hydrophobic silica C1 was changed to 3 parts of hydrophobic silica C3 (average primary particle size 20 nm). Example 1 Toner as in Toner Production Example 1 except that 15 parts of toner air classification fine powder was changed to 15 parts of Production Example 3 toner air classification fine powder and D4 of the toner base obtained by the classification treatment was changed to 6.1 μm. Was made.
The presence or absence of the formation of a phase separation structure of the crystalline polyester resin and the amorphous resin was examined by measuring the X-ray diffraction pattern of the obtained toner. As a result, the diffraction peak attributed to the crystalline polyester resin was at least 19 to 20 °. It exists in the position of 21-22 degrees, 23-25 degrees, 29-31 degrees, and has confirmed having formed the phase-separation structure.

<Toner Production Example 4>
In Toner Production Example 1, 10 parts of crystalline polyester resin A1 was changed to 0 part, 20 parts of non-crystalline polyester resin B-L1 was changed to 30 parts, and 1 part of hydrophobic silica C1 was replaced with hydrophobic silica C3 (average The primary particle size 20 nm) is changed to 3 parts, and the toner base D4 obtained by classification is changed to 15 μm from the production example 1 toner air classification fine powder 15 parts to the production example 4 toner air classification fine powder 15 parts and 6.1 μm. A toner was prepared in the same manner as in Toner Production Example 1 except that.

<Toner Production Example 5>
In toner production example 1, 10 parts of crystalline polyester resin A1 is changed to 20 parts of crystalline polyester resin A3, 1 part of hydrophobic silica C1 is changed to 0 part, and production example 1 15 parts of toner air classification fine powder is produced. Example 5 A toner was prepared in the same manner as in Toner Production Example 1 except that the toner base classification fine powder was changed to 15 parts, and D4 of the toner base obtained by classification was changed to 6.1 μm.
The presence or absence of the formation of a phase separation structure of the crystalline polyester resin and the amorphous resin was examined by measuring the X-ray diffraction pattern of the obtained toner. As a result, the diffraction peak attributed to the crystalline polyester resin was at least 19 to 20 °. It exists in the position of 21-22 degrees, 23-25 degrees, 29-31 degrees, and has confirmed having formed the phase-separation structure.

<Toner Production Example 6>
In toner production example 1, 10 parts of crystalline polyester resin A1 was changed to 40 parts of crystalline polyester resin A2, and 1 part of hydrophobic silica C1 was changed to 5 parts of organically modified montmorillonite (Kreton APA pulverized product, average primary particle size 1000 nm). Production Example 1 Toner Production Example 1 except that 15 parts of toner wind classification fine powder was changed to 15 parts of production wind toner fine classification fine powder and D4 of the toner base obtained by classification was changed to 6.1 μm. A toner was prepared in the same manner as described above.
The presence or absence of the formation of a phase separation structure of the crystalline polyester resin and the amorphous resin was examined by measuring the X-ray diffraction pattern of the obtained toner. As a result, the diffraction peak attributed to the crystalline polyester resin was at least 19 to 20 °. It exists in the position of 21-22 degrees, 23-25 degrees, 29-31 degrees, and has confirmed having formed the phase-separation structure.

<Toner Production Example 7>
(Production of modified polyester)
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 690 parts of bisphenol A ethylene oxide 2-mole adduct and 256 parts of terephthalic acid were subjected to polycondensation at 230 ° C. for 8 hours under normal pressure, and then reduced in pressure to 10 to 15 mmHg. And then cooled to 160 ° C., 18 parts of phthalic anhydride was added thereto and reacted for 2 hours to obtain unmodified polyester (1). The obtained polyester (1) had a weight average molecular weight of 4,000, an acid value of 10 KOH mg / g, and a glass transition point of 50 ° C.

(Prepolymer production)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 800 parts of bisphenol A ethylene oxide 2-mol adduct, 180 parts of isophthalic acid, 60 parts of terephthalic acid, and 2 parts of dibutyltin oxide were placed at normal pressure. The mixture was reacted at 8 ° C. for 8 hours, further reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, cooled to 160 ° C., 32 parts of phthalic anhydride was added thereto, and reacted for 2 hours. Next, the mixture was cooled to 80 ° C. and reacted with 170 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate group-containing prepolymer (1).

(Production of ketimine compounds)
In a reaction vessel equipped with a stir bar and a thermometer, 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain a ketimine compound (1).

(Manufacture of toner)
In a beaker, 14.3 parts of the prepolymer (1), 45 parts of polyester (1), and 78.6 parts of ethyl acetate were stirred and dissolved. Next, 10 parts of crystalline polyester resin A2, 8 parts of paraffin WAX (melting point 70 ° C.) as a release agent, 4 parts of copper phthalocyanine blue pigment, organically modified montmorillonite (Kreton APA pulverized product, average primary particle size 1000 nm) 5 parts was added, and the mixture was stirred at 60 ° C. with a TK homomixer at 12000 rpm for 5 minutes. Dispersed in a bead mill for 30 minutes at 20 ° C. This is designated as toner material solution (1). Next, 306 parts of ion-exchanged water, 265 parts of tricalcium phosphate 10% suspension, and 0.2 part of sodium dodecylbenzenesulfonate were placed in a beaker and dissolved uniformly. The toner material solution (1) and 2.7 parts of the ketimine compound (1) were then added and reacted with urea while stirring at 12000 rpm with a TK homomixer. When the particle size is large while observing the particle size and particle size distribution with an optical microscope, the stirring speed is increased to 14000 and the process is further performed for 5 minutes. If it is smaller, change the stirring to 10,000 rpm and repeat the experiment. Thereafter, the solvent was removed under reduced pressure for 1.0 hour, filtered, washed and dried, followed by air classification to obtain base particles having irregularities on the surface and D4 of 6.1 μm. To 100 parts of the toner base thus obtained, 0.5 part of hydrophobic silica C1 and 0.5 part of titanium oxide D1 (average primary particle size 21 nm) were added and mixed with a Henschel mixer to obtain the toner of Production Example 7.
The presence or absence of the formation of a phase separation structure of the crystalline polyester resin and the amorphous resin was examined by measuring the X-ray diffraction pattern of the obtained toner. As a result, the diffraction peak attributed to the crystalline polyester resin was at least 19 to 20 °. It exists in the position of 21-22 degrees, 23-25 degrees, 29-31 degrees, and has confirmed having formed the phase-separation structure.

<Toner Production Example 8>
A toner of Toner Production Example 8 was obtained in the same manner as in Toner Production Example 7 except that 3.5 parts of organically modified montmorillonite (Clayton APA pulverized product, average primary particle size 1000 nm) was changed to 0 parts.

<Example of carrier production>
(I) Core material: Cu—Zn ferrite particles (volume average diameter: 45 μm) 5000 parts (ii) Coating material Toluene 450 parts Silicone resin SR2400
(Toray Dow Corning Silicone, 50% nonvolatile content) 450 parts Aminosilane SH6020
(Toray / Dow Corning / Silicone) 10 parts Carbon black 10 parts

The above coating material is dispersed with a stirrer for 10 minutes to prepare a coating solution, and the coating solution and the core material are provided with a rotating bottom plate disk and a stirring blade in a fluidized bed, and a coating apparatus for coating while forming a swirling flow The coating liquid was applied onto the core material.
Next, the obtained carrier was baked in an electric furnace at 250 ° C. for 2 hours, and the carrier particles of the production example (saturation magnetization 65 emu / g when 3 kOe was applied, residual magnetization 0 emu / g when 3 kOe was applied, specific resistance 3.2). × 10 ⁸ Ω · cm, volume average diameter 45 μm).

<Examples of developer production>
Developer (1) corresponding to each toner corresponding to Toner Production Examples 1 to 8 by mixing 2.5 parts of the toner of Production Examples 1 to 8 and 97.5 parts of the carrier of the Production Examples with a turbula mixer To (8) was obtained.

<Example of fixing belt production>
The fixing belt (FIGS. 3 and 45) of this example was manufactured as follows.
A primer (DY39-067 manufactured by Dow Corning Toray Co., Ltd.) was formed on the outer periphery of a cylindrical endless film base made of polyimide with a thickness of 90 μm by spray coating and dried at room temperature. Thereafter, two-component addition type liquid silicone rubber (DY35-2083 manufactured by Toray Dow Corning Silicone Co., Ltd.) is mixed with two components, diluted with toluene in an appropriate amount, applied by spray coating to a thickness of 200 μm, and cured at 120 ° C. for 10 minutes. Further, secondary curing was performed at 200 ° C. for 4 hours to form an elastic layer.
Subsequently, a primer (PR-990CL manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) was spray-coated at a thickness of 4 μm and then dried at 150 ° C. for 30 minutes.
Then, in the contents of Table 5, PFA having a higher copolymerization ratio of perfluoroalkyl vinyl ether than general PFA (in the table, it is represented by oxygen: carbon atom number in the PFA molecular chain. Dispersions were prepared by mixing equal amounts of general-purpose PFA with a high vinyl ether ratio) and PFA having a different MFR (the smaller the MFR, the worse the fluidity).

  In the production examples of the present invention, dispersions were prepared according to the combinations shown in Table 5, PFA dispersions were spray-coated at a thickness of 30 μm, and then baked at 340 ° C. for 30 minutes to obtain fixing belts of Production Examples 1 to 7.

The PFA used in the production examples is as follows.
A: 950HP Plus manufactured by Mitsui & DuPont Fluorochemicals
B: 945HP Plus made by Mitsui DuPont Fluorochemicals
C: 940HP Plus manufactured by Mitsui DuPont Fluorochemicals
D: 350-J manufactured by Mitsui DuPont Fluorochemical Co., Ltd.
E: 340-J manufactured by Mitsui / Dupont Fluorochemical
MFR is a measured value at JIS-K7210 372 ° C. and 5 kgf load.

Examples 1-9 and Comparative Examples 1-7
Using the developer (1) to (8) obtained in the developer production example and the fixing belt production examples 1 to 7, using an image forming apparatus having a fixing device as shown in FIG. evaluated.
<Evaluation method>
Low temperature fixability:
In the low-temperature fixing property evaluation, the fixing belts of Production Examples 1 to 7 are incorporated in the fixing device of FIG. 2, and the temperature of the fixing belt is changed by 5 ° C. Obtained.
The copy image at each temperature was rubbed 10 times with a clock meter equipped with a sand eraser, the image density before and after that was measured, and the fixing rate was determined by the following formula.
Fixing rate (%)
= (Image density after rubbing sand eraser 10 times) / (Image density before rubbing) × 100
The temperature at which a fixing rate of 70% was achieved was defined as the minimum fixing temperature.
Evaluation was made by classifying the lower limit fixing temperature into three ranks of low, low, and low.
The fixing roller was evaluated under the condition that no oil was applied, and the transfer paper was Ricoh Full Color PPC paper type 6000 <70 W.

Flexibility:
The fixing device shown in FIG. 2 incorporates the fixing belts of Production Examples 1 to 7, and after the output of 300,000 sheets, the release layer has no crack, and there is a slight crack that does not cause an abnormal image. A case was evaluated as Δ, and a case where cracks at a level causing an abnormal image appeared was evaluated as ×.

Abrasion resistance:
The fixing device shown in FIG. 2 incorporates the fixing belts of Production Examples 1 to 7 into the fixing device shown in FIG. 2, and after the output of 300,000 sheets, the contact portion of the thermistor does not have an abnormal image. The case with wear was evaluated as Δ, and the case with wear at a level causing an abnormal image was evaluated as ×.

Uneven gloss:
The gloss unevenness is an index reflecting the surface smoothness of the fixing belt. The fixing device of Production Examples 1 to 7 is incorporated in the fixing device of FIG. 2 and outputs a fixed image. The one having no gloss unevenness is indicated by ○, the one having slight gloss unevenness is indicated by Δ, and the one having remarkable gloss unevenness is provided. It evaluated by x.

Chile, electrostatic offset evaluation method:
For the dust and electrostatic offset of the toner image on the transfer material, the fixing belt of Production Examples 1 to 7 is incorporated in the fixing device of FIG. 2, and the image is output in a low temperature and low humidity environment of 10 ° C. and 15% RH. Evaluation was made by visually checking the image. Those with no dust and offset were marked with “O”, and those with confirmed dust and offset were marked with “X”.

Table 6 shows the evaluation results of Examples and Comparative Examples.

1 is a schematic diagram for explaining an image forming apparatus of the present invention. 1 is a schematic diagram illustrating an example of a configuration of a fixing device used in an image forming apparatus of the present invention. 3 is a cross-sectional view illustrating an example of a configuration of a fixing belt of the fixing device of the image forming apparatus of the present invention. FIG. It is a flow curve for demonstrating the measuring method of the softening temperature [T (F1 _{/ 2} )] of resin.

Explanation of symbols

1Y, 1M, 1C, 1Bk photosensitive drum 2Y, 2M, 2C, 2Bk charging device 3Y, 3M, 3C, 3Bk exposure device 4Y, 4M, 4C, 4Bk developing device 5Y, 5M, 5C, 5Bk transfer roller 6Y, 6M, 6C, 6Bk cleaner 10Y, 10M, 10C, 10Bk Image forming unit 20 Conveying belt 30 Paper feeding mechanism 40 Fixing device 41 Fixing roller 42 Pressure roller 43, 48 Spring 44 Heating roller 45 Fixing belt 46 Halogen lamp 47 Tension roller 49 Thermistor 451 Base 452 Elastic layer 453 Release layer (surface layer)

Claims (8)

  An image forming apparatus having a fixing unit for fixing a toner image on a recording medium by heat and pressure, wherein the toner forming the toner image has crystallinity substantially incompatible with at least a binder resin. It contains a polyester resin (crystalline polyester) and an amorphous resin, and contains inorganic fine particles having an average particle diameter of 5 to 1000 nm in the toner. The fixing rotator is composed of a tetrafluoroethylene-perfluoroalkylvinylether copolymer resin (PFA) having a ratio of the number of oxygen atoms / number of carbon atoms in the molecular chain of 1/60 or more on the outer peripheral surface thereof. An image forming apparatus having a surface layer formed thereon.   2. The image forming apparatus according to claim 1, wherein the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) has a melt flow rate (MFR) (JISK 7210, 372 ° C., 5 kgf load) of 3 (g / 10 minutes). An image forming apparatus comprising a mixture of the following tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) and a PFA having an MFR of 7 (g / 10 min) or more. 3. The image forming apparatus according to claim 1, wherein the surface layer of the fixing rotator includes at least a PFA having an MFR of 3 (g / 10 minutes) or less and a PFA having an MFR of 7 (g / 10 minutes) or more. It is fired after coating the mixed dispersion,
Average particle diameter of PFA with MFR of 3 (g / 10 min) or less
An image forming apparatus characterized by satisfying the relationship of the average particle diameter of PFA having an MFR of 7 (g / 10 min) or more. 4. The image forming apparatus according to claim 1, wherein the content of the polyester resin (crystalline polyester) having crystallinity in the binder resin of the toner forming the toner image is 1 to 50 wt%. %, And 1/2 outflow temperature T (F _1/2 ) of crystalline polyester is 80 to 130 ° C.   5. The image forming apparatus according to claim 1, wherein the content of the inorganic fine particles contained in the toner forming the toner image is 0.1 to 5 wt% with respect to 100 parts by weight of the toner. An image forming apparatus.   6. The image forming apparatus according to claim 1, wherein the inorganic fine particles contained in the toner forming the toner image are montmorillonite or a modified product thereof, silica, titanium oxide, or alumina. An image forming apparatus, comprising:   The image forming apparatus according to claim 1, wherein the toner has an amorphous polyester prepolymer, an amorphous polyester, a crystalline polyester, or a colorant having at least a functional group containing a nitrogen atom. An image forming apparatus comprising a toner material liquid obtained by dispersing a release agent and inorganic fine particles in an organic solvent by crosslinking and / or elongation reaction in an aqueous medium.   A process cartridge for use in the image forming apparatus according to claim 1, comprising: an electrophotographic photosensitive member; and at least one unit selected from a charging unit, an exposure unit, a developing unit, and a cleaning unit. A process cartridge that is integrated and detachably mounted.

Images