JP7013762B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

In the formation of an image by the electrophotographic method, for example, after charging the surface of the image holder, an electrostatic charge image is formed on the surface of the image holder according to the image information, and then the static charge image is developed containing toner. It is performed by developing with an agent to form a toner image, and transferring and fixing the toner image on the surface of a recording medium.

Here, Patent Document 1 includes "a plurality of magnet members having an image holder for holding an image and a toner moving mechanism for moving the toner in the developing agent to the image holder, and the toner moving mechanism has a plurality of magnet members. The magnet member equipped with the magnetic poles has the developing magnetic poles arranged near the moving region where the toner moves from the developing agent holding body to the image holding body, and the layer thickness of the developing agent adsorbed on the surface of the developing agent holding member. The layer thickness regulating magnetic pole arranged in the vicinity of the layer thickness regulating member to be regulated and the attracting magnetic pole for adsorbing the developer on the surface of the developer holder are included, and the magnetic force of the developing magnetic pole is T1 and the layer thickness is said. When the magnetic force of the regulating magnetic pole is T2 and the magnetic force of the attracting magnetic pole is T3, 90 (mT) ≤ T1 ≤ 120 (mT), 50 (mT) ≤ T2 ≤ 75 (mT), and 40 (mT). mT) ≦ T3 ≦ 55 (mT), and T2 <−αT3 + β (α and β are constants). ”Is disclosed.

Patent Document 2 states that "a one-component magnetic toner containing wax as a developer, having an average particle size of 8 μm or less and a 5 μm under amount of 30 wt% or less is used, and a magnet member is disposed inside. A thin layer of toner holder that holds one-component magnetic toner and conveys it to the development area facing the latent image carrier, and one-component magnetic toner that comes into contact with the surface of the toner holder and is supplied to the holder. It is a developing device provided with a layer forming member, and the contact line pressure of the layer forming member with the toner holding body is 30 to 100 gf / cm, and the upstream side of the contact portion of the toner holding body with the layer forming member. An image forming apparatus including a one-component developing apparatus in which the magnetic force of the toner transport electrode of the toner member arranged at a position corresponding to the vicinity is 30 to 65 mT is disclosed. "

Patent Document 3 states that "a carboxylic acid in which the binder resin is composed of 70 to 85 mol% of an aromatic dicarboxylic acid component (a) and 15 to 30 mol% of a trivalent or higher polyvalent carboxylic acid component (b). 0.1-1.2 mol of propoxylated and / or ethoxylated etherified diphenol component (c) and 0.01-0.15 mol of aliphatic diol component (d) are added to 1 mol of the component. Condensed acid value is 6 to 15 mgKOH / g, weight average molecular weight Mw is 15,000 to 60,000, number average molecular weight Mn is 2,000 to 4,000, weight average molecular weight Mw and number average molecular weight Mn. A polyester resin having a ratio (Mw / Mn) of 6 to 18, a glass transition point of 50 to 60 ° C., and a softening point of 100 to 120 ° C. is disclosed.

Japanese Unexamined Patent Publication No. 2015-205896 Japanese Unexamined Patent Publication No. 08-20216 Japanese Unexamined Patent Publication No. 2000-056504

By the way, in an electrophotographic image forming apparatus, an electrostatic charge image formed on the surface of an image holder is developed with a developer containing toner to form a toner image, and the toner image is recorded from the image holder as a recording medium. After transferring to the surface of the image, the toner image is fixed to form an image on the recording medium. The toner contains an amorphous polyester resin as the binder resin, and the weight average molecular weight is Mw (A) and the number average molecular weight is Mn (A) in the gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles. When Mw (A) is 25,000 or more and 60,000 or less, Mw (A) / Mn (A) is 5 or more and 10 or less, with respect to the absorbance of a wave number of 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles. The ratio of the absorbance of the wave number 1500 cm ^-1 is 0.6 or less, and the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.4 or less. When a static charge image developer having (also referred to as "specific toner") is applied, the external additive may be buried in the toner particles in a high temperature and high humidity environment.

Therefore, an object of the present invention is to have a plurality of magnetic poles in which magnet members are arranged in the circumferential direction in an image forming apparatus to which a specific toner is applied, and among the plurality of magnetic poles, a magnetic pole having a position facing the layer regulating member. It is an object of the present invention to provide an image forming apparatus that suppresses the embedding of an external additive in toner particles generated in a high temperature and high humidity environment, as compared with the case where a developing means having a magnetic pole of more than 70 mT is provided.

The above problem is solved by the following invention. That is,

The invention according to < 1 > is
Image holder and
A charging means for charging the surface of the image holder, and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
When an amorphous polyester resin is contained as the binder resin, the weight average molecular weight is Mw (A), and the number average molecular weight is Mn (A) in the gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles. Mw (A) is 25,000 or more and 60,000 or less, Mw (A) / Mn (A) is 5 or more and 10 or less, and the wave number is 1500 cm ^-1 with respect to the absorbance of the wave number 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles. Electrostatic charge image development with toner containing toner particles and an external additive, the ratio of the absorbance of 720 cm ^-1 to the absorbance of 720 cm ^-1 is 0.4 or less. A developing means for accommodating an agent and developing an electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer, which is a non-rotatably supported magnet member and the magnet. Layer thickness of a developer holder having a rotating member arranged around the outer periphery of the member and holding the electrostatic charge image developer on the surface and rotating, and a static charge image developer held on the surface of the rotating member. The magnet member has a plurality of magnetic poles arranged in the circumferential direction, and the magnetic force of the magnetic pole of the plurality of magnetic poles at a position facing the layer regulating member is 30 mT. A developing means having a charge of 70 mT or less and
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium,
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus.

The invention according to < 2 > is
In the infrared absorption spectrum analysis of the toner particles, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.5 or less, and the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is The image forming apparatus according to < 1 > , which is 0.3 or less.

The invention according to < 3 > is
In the infrared absorption spectrum analysis of the toner particles, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.2 or more, and the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is. The image forming apparatus according to < 1 > or < 2 > , which is 0.05 or more.

The invention according to < 4 > is
The image formation according to any one of < 1 > to < 3 > , wherein the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 1500 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.5 or less. Device.

The invention according to < 5 > is
The image forming apparatus according to < 4 > , wherein the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 1500 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.4 or less.

The invention according to < 6 > is
The image forming apparatus according to any one of < 1 > to < 5 > , wherein the peak molecular weight of the molecular weight distribution curve obtained by gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles is 7000 or more and 11000 or less. ..

The invention according to < 7 > is
The image forming apparatus according to < 6 > , wherein the peak molecular weight of the molecular weight distribution curve obtained by gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles is 8000 or more and 11000 or less.

The invention according to < 8 > is
The image forming apparatus according to any one of < 1 > to < 7 > , wherein the toluene insoluble content of the toner particles is 28% by mass or more and 38% by mass or less.

The invention according to < 9 > is
The image forming apparatus according to < 8 > , wherein the toluene insoluble content of the toner particles is 30% by mass or more and 35% by mass or less.

The invention according to < 10 > is
The image forming apparatus according to any one of < 1 > to < 9 > , wherein the toner particles contain a crystalline resin.

The invention according to < 11 > is
The image forming apparatus according to < 10 > , wherein the content of the crystalline resin is 3% by mass or more and 20% by mass or less with respect to the total amount of the toner.

The invention according to < 12 > is
The image forming apparatus according to < 11 > , wherein the content of the crystalline resin is 5% by mass or more and 15% by mass or less with respect to the total amount of the toner.

The invention according to < 13 > is
The image forming apparatus according to any one of < 1 > to < 12 > , wherein the magnetic force of the magnetic pole having a position facing the layer regulating member is 30 mT or more and 65 mT or less.

The invention according to < 14 > is
The image forming apparatus according to < 13 > , wherein the magnetic force of the magnetic pole having a position facing the layer regulating member is 40 mT or more and 65 mT or less.

The invention according to < 15 > is
The image forming apparatus according to any one of < 1 > to < 14 > , wherein the length of the gap between the rotating member and the layer regulating member is 0.1 mm or more and 1.0 mm or less.

The invention according to < 16 > is
The image forming apparatus according to < 15 > , wherein the length of the gap between the rotating member and the layer regulating member is 0.2 mm or more and 0.8 mm or less.

According to the invention according to < 1 > , < 2 > , < 3 > , < 4 > , < 5 > , < 6 > , or < 7 > , in the image forming apparatus to which the specific toner is applied, the magnet member is in the circumferential direction. Toner generated in a high temperature and high humidity environment as compared with the case of providing a developing means having a plurality of magnetic poles arranged in the same direction and having a magnetic force of a magnetic pole having a magnetic force of more than 70 mT among the plurality of magnetic poles at a position facing the layer regulating member. An image forming apparatus for suppressing the embedding of an external additive in particles is provided.
According to the invention according to < 8 > or < 9 > , an external additive to the toner particles generated in a high temperature and high humidity environment as compared with the case where the toluene insoluble content of the toner particles is less than 28% by mass or more than 38% by mass. An image forming apparatus for suppressing the burial of particles is provided.
According to the invention according to < 10 > , < 11 > , or < 12 > , an image forming apparatus that suppresses the embedding of an external additive in the toner particles is provided as compared with the case where the toner particles do not contain a crystalline resin. Toner.
According to the invention according to < 13 > or < 14 > , the external additive to the toner particles generated in a high temperature and high humidity environment is compared with the case where the magnetic force of the magnetic pole held at the position facing the layer regulating member exceeds 65 mT. An image forming apparatus for suppressing the burial of a magnet is provided.
According to the invention according to < 15 > or < 16 > , the length of the gap between the rotating member and the layer regulating member is less than 0.1 mm, as compared with the case where the toner particles are generated in a high temperature and high humidity environment. An image forming apparatus for suppressing the burial of an external additive is provided.

It is a schematic block diagram which shows an example of the image forming apparatus which concerns on this embodiment. It is a partial block diagram which shows the structure around the intermediate transfer belt of the image forming apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of the developing apparatus of the image forming apparatus which concerns on this embodiment. It is a partial block diagram which shows the circumference of the trimmer (an example of a layer regulation member) of the developing apparatus of the image forming apparatus which concerns on this embodiment.

Hereinafter, embodiments that are an example of the present invention will be described in detail.

<Image forming device>
An image holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming a static charge image on the surface of the charged image holder, and a static charge image developer having toner (hereinafter referred to as "development"). A developing means that houses an agent) and develops an electrostatic charge image formed on the surface of the image holder as a toner image by a developer, and a toner image formed on the surface of the image holder as a recording medium. A transfer means for transferring to the surface and a fixing means for fixing the toner image transferred to the surface of the recording medium are provided.

The developing means includes a magnet member that is non-rotatably supported, a developer holder having a rotating member that is arranged around the outer periphery of the magnet member and holds the developer on the surface and rotates, and is held on the surface of the rotating member. A layer regulating member that regulates the layer thickness of the developed developer is provided, and the magnet member has a plurality of magnetic poles arranged in the circumferential direction, and among the plurality of magnetic poles, a magnetic pole having a position facing the layer regulating member. The magnetic force of is 30 mT or more and 70 mT or less.

The toner (specific toner) contains an amorphous polyester resin as a binder resin, and gel permeation chromatography (GPC) measurement of the tetrahydrofuran-soluble content (hereinafter, also referred to as "THF-soluble content") of the toner particles is performed. When the weight average molecular weight is Mw (A) and the number average molecular weight is Mn (A), Mw (A) is 25,000 or more and 60,000 or less, and Mw (A) / Mn (A) is 5 or more and 10 or less. In the infrared absorption spectrum analysis of toner particles, the ratio of the absorbance of wave number 1500 cm ^-1 to the absorbance of wave number 720 cm ^-1 is 0.6 or less, and the ratio of the absorbance of wave number 820 cm ^-1 to the absorbance of wave number 720 cm ^-1 . Contains toner particles having a value of 0.4 or less and an external additive.

Here, in the specific toner, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.6 or less, and the wave number 820 cm ^- with respect to the absorbance of the wave number 720 cm ^-1 . The absorbance ratio of ¹ is 0.4 or less. The fact that the toner particles have this infrared absorption spectral characteristic means that the amorphous polyester resin as the binder resin has an alkylene oxide adduct of bisphenol A (ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A). , Ethylene oxide propylene oxide adduct of bisphenol A, etc.) is not used as a polyhydric alcohol, or even if it is used, it means that the resin is in a small amount.

Then, in order to improve the fixability of the fixed image using this specific toner, the weight average molecular weight is Mw (A) and the number average molecular weight is Mn (A) in the gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles. ), It is appropriate that Mw (A) is 25,000 or more and 60,000 or less, and Mw (A) / Mn (A) is 5 or more and 10 or less. That is, it is appropriate that the molecular weight characteristics of the non-crosslinked binder resin component mainly have the above characteristics.
Specifically, when Mw (A) is less than 25,000, hot offset (a phenomenon in which toner is excessively melted and adheres to a fixing member) at the time of fixing is likely to occur, and when Mw (A) exceeds 60,000. The minimum fixing temperature tends to increase. Further, when Mw (A) / Mn (A) exceeds 10, a difference occurs in the meltability of the resin, and unevenness is likely to occur in the fixed image. It is difficult in manufacturing to make Mw (A) / Mn (A) less than 5.
As described above, when the molecular weight characteristics of the specific toner (the toner particles thereof) are set to the above characteristics, the fixing property of the image is improved.

However, when a specific toner is used, the external additive may be embedded in the toner particles in a high temperature and high humidity environment (for example, at 35 ° C. and 85% environment). The reason is presumed as follows. The specific toner is derived from the amorphous polyester resin and has a property of high hygroscopicity. Therefore, in a high temperature and high humidity environment, the specific toner (the toner particles) is plasticized by absorbing moisture.
On the other hand, in the developing means, a high mechanical load is applied to the toner because the developer containing the toner is held on the surface of the rotating member of the developing holder, and the layer thickness of the developing agent is increased by the layer regulating member. It's time to be regulated.
Therefore, when the layer thickness of the developer containing the specified toner that has been plasticized is regulated by the layer regulating member in a high temperature and high humidity environment, the external additive is easily embedded in the toner particles due to a mechanical load.

Therefore, in the image forming apparatus according to the present embodiment, as the developing apparatus, the magnet members of the developer holder have a plurality of magnetic poles arranged in the circumferential direction, and among the plurality of magnetic poles, the positions facing the layer regulating member. A developing means having a magnetic force of 30 mT or more and 70 mT or less is applied.
As a result, the magnetic force applied between the rotating member of the developer holder and the layer regulating member is reduced. Then, when the layer thickness of the developer is regulated by the layer regulating member, the binding force of the specific toner due to the magnetic force is relaxed. Specifically, for example, in the case of a two-component developer, the magnetic force relaxes the binding force of the magnetic brush (the layer in which the spiked carriers hold the toner) held on the surface of the rotating member of the developer holder. , Increases flexibility. Therefore, the mechanical load on the specific toner is reduced, and the embedding of the external additive in the toner particles is suppressed.

From the above, in the image forming apparatus according to the present embodiment, the embedding of the external additive in the toner particles generated in a high temperature and high humidity environment is suppressed.

Here, the image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is intermediate. An intermediate transfer type device that first transfers the toner image to the surface of the transfer body and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; the surface of the image holder after the transfer of the toner image and before charging. A well-known image forming apparatus such as a device provided with a static eliminator that irradiates and eliminates static light is applied.
In the case of an intermediate transfer type device, the transfer device is, for example, a primary transfer in which a toner image is transferred to the surface of the intermediate transfer body and a toner image formed on the surface of the image holder is primarily transferred to the surface of the intermediate transfer body. A configuration comprising a member and a secondary transfer member that secondary transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, a portion including at least an image holder may have a cartridge structure (process cartridge) attached to and detached from the image forming apparatus.

Hereinafter, the image forming apparatus according to this embodiment will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus according to the present embodiment.
As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment has a paper accommodating portion in which a recording sheet PA as an example of a recording medium is accommodated from the lower side to the upper side in the vertical direction (arrow Y direction). An image forming unit 14 provided on the paper accommodating unit 12 and forming an image on the recording paper PA supplied from the paper accommodating unit 12, and a scanned document (not shown) provided on the image forming unit 14. It includes a document reading unit 16 to be read and a control unit 20 provided in the image forming unit 14 to control the operation of each unit of the image forming apparatus 10.
In the following description, the upward direction of the device main body 10A when the image forming device 10 is viewed from the front is the Y direction, the horizontal direction (right direction) is the X direction, and the depth direction from the front side to the back side is the Z direction. Describe. Further, the directions opposite to the X, Y, and Z directions are described as the −X, −Y, and −Z directions.

The paper storage unit 12 is provided with a first storage unit 22, a second storage unit 24, and a third storage unit 26 in which recording paper PAs of different sizes are stored. In the first accommodating portion 22, the second accommodating portion 24, and the third accommodating portion 26, a delivery roll that sends out the accommodating recording paper PA (an example of a recording medium) to a transport path 28 provided in the image forming apparatus 10. 32 is provided. A pair of transport rolls 34 and transport rolls 36 for transporting the recording paper PA one by one are provided on the downstream side of the feed roll 32 in the transport path 28. Further, on the downstream side of the transport roll 36 in the transport direction of the recording paper PA in the transport path 28, a alignment roll 38 that temporarily stops the recording paper PA and sends the recording paper PA to the secondary transfer position described later at a predetermined timing is provided. It is provided.

The upstream portion of the transport path 28 (the portion where the transport roll 36 is provided) is a straight line from the left side of the paper accommodating portion 12 to the lower left side of the image forming portion 14 in the Y direction in the front view of the image forming apparatus 10. It is provided in a shape. Further, the downstream portion of the transport path 28 is provided from the lower left side of the image forming portion 14 to the paper ejection portion 15 provided on the right side surface of the image forming portion 14. Further, the transport path 28 is connected to a double-sided transport path 29 in which the recording paper PA is transported and inverted in order to form an image on both sides of the recording paper PA.

The double-sided transport path 29 is a first reversal path 33 provided linearly in the Y direction from the lower right side of the image forming section 14 to the right side of the paper accommodating section 12 and a first reversing path in the front view of the image forming apparatus 10. A second reversing path 35, a transport path 28, a first reversing path 33, and a second reversing path, in which the rear end of the recording paper PA conveyed to 33 enters and the recording sheet PA is conveyed to the left side of the figure in the X direction. It has a switching member (not shown) for switching 35. A pair of transport rolls 42 are provided at a plurality of locations at intervals on the first reversing path 33, and a pair of transport rolls 44 are provided at a plurality of locations at intervals on the second reversing path 35. Has been done.

The downstream end of the second reversing path 35 is a guide member on the front side (upstream side) of the transport roll 36 on the most downstream side among the plurality of transport rolls 36 on the upstream side of the transport path 28. It is connected by (not shown).

The document scanning unit 16 is composed of a document transporting device 52 that automatically transports scanned documents one by one, a platen glass 54 that is arranged under the document transporting device 52 and on which one scanned document is placed, and a document transporting device 52. A document reading device 56 for reading the transported scanned document or the scanned document placed on the platen glass 54 is provided.

On the other hand, the image forming unit 14 includes an image forming unit 60 for forming a toner image, an intermediate transfer belt 62 provided so as to be rotatable (circumferentially moving) in the direction of arrow A and holding a toner image on the outer periphery, and an image forming unit 60. With four primary transfer rolls 64 for primary transfer of the toner image formed in the above to the intermediate transfer belt 62, and one secondary transfer roll 66 for secondary transfer of the toner image on the intermediate transfer belt 62 to the recording paper PA. , Are provided.

As shown in FIG. 2, as an example, the image forming unit 60 is a plurality of image forming units 60Y in which toner images of each color of Y (yellow), M (magenta), C (cyan), and K (black) are formed. , 60M, 60C, 60K. The image forming units 60Y, 60M, 60C, and 60K have the same basic configuration except that the toner colors are different. Therefore, the image forming unit 60K will be described, and the reference numerals and explanations of the other image forming units 60Y, 60M, and 60C will be omitted.

Further, in the following description, when it is necessary to distinguish each member constituting the image forming unit 60Y, 60M, 60C, 60K for each toner color (Y, M, C, K), it is added to the end of the code of the member. Subscripts Y, M, C, and K indicating the toner color are added to distinguish them, and when it is not necessary to distinguish each toner color (Y, M, C, K), the subscripts Y, M, C, and K are omitted. Each member may be described by a reference numeral.

The image forming unit 60K includes a photoconductor 72 as an example of an image holder that holds an electrostatic charge image and a toner image on the outer peripheral surface, a charging device 74 (an example of charging means) that charges the outer peripheral surface of the photoconductor 72, and an image holder. An exposure apparatus 76 (an example of a static charge image forming means) that exposes the outer peripheral surface of the charged photoconductor 72 to form a static charge image on the photoconductor 72, and a static charge image formed on the photoconductor 72 are K. It includes a developing device 100 that develops with colored toner to form a toner image (K color), and a cleaning device 78 that cleans the outer peripheral surface of the photoconductor 72 after the primary transfer.
The details of the developing device 100 will be described later.

The photoconductor 72 has a cylindrical shape and is arranged to face the intermediate transfer belt 62 with the width direction of the intermediate transfer belt 62 as the axial direction. ) Is rotatably supported. Further, the charging device 74 is, for example, a scorotron type charging device, and charges the outer peripheral surface of the photoconductor 72 with the same polarity as the charging polarity of the toner (as an example, a negative polarity) by electric discharge.

The exposure apparatus 76 includes a semiconductor laser, an f-θ lens (not shown), a polygon mirror 76A, an imaging lens (not shown), and a plurality of mirrors 76B. Then, the exposure apparatus 76 deflects and scans the laser beam B emitted from the semiconductor laser based on the image information of K color (black color) with the polygon mirror 76A, and the outer peripheral surface of the photoconductor 72 charged by the charging apparatus 74. Is irradiated (exposed) to form a static charge image. The exposure apparatus 76 is not limited to the method of deflecting and scanning the laser beam with the polygon mirror, and may be an LED (Light Emitting Diode) method.

The cleaning device 78 has a cleaning roll 78A that is axially aligned with the photoconductor 72. Then, the cleaning roll 78A rotates while in contact with the outer peripheral surface of the photoconductor 72 to collect toner, dust, and the like remaining on the outer peripheral surface of the photoconductor 72 after the primary transfer.

As an example, the intermediate transfer belt 62 contains a polyimide resin as a main component and is formed in a cylindrical shape. Further, inside the intermediate transfer belt 62, a drive roll 61 for moving the intermediate transfer belt 62 from the upstream side to the downstream side in the direction of arrow A, and a photoconductor 72 (grounded) while a voltage is applied. The primary transfer roll 64 that primary transfers the toner image to the intermediate transfer belt 62 by the potential difference, the support roll 63 that supports the intermediate transfer belt 62 from the inside, the tension applying roll 65 that applies tension to the intermediate transfer belt 62, and the intermediate transfer. The counter roll 67, which is arranged inside the secondary transfer position of the belt 62 and serves as the counter electrode of the secondary transfer roll 66, and the support roll 69 are provided so as to be rotatable in the counterclockwise direction shown in the drawings.

The intermediate transfer belt 62 is supported by being wound around a drive roll 61, four primary transfer rolls 64, a support roll 63, a tension applying roll 65, an opposing roll 67, and a support roll 69, and is supported by the drive roll 61. Is driven to rotate by a drive means (not shown) including a motor, so that the wheel orbits in the direction of arrow A.

Both ends of the primary transfer roll 64 are rotatably supported by bearings (not shown), and the outer peripheral surface is in contact with the inner peripheral surface of the intermediate transfer belt 62. Further, in the primary transfer roll 64, a voltage having a polarity (positive polarity) opposite to the polarity of the toner image transferred to the intermediate transfer belt 62 is applied to the core metal (not shown). Here, each photoconductor 72 is grounded, and a potential difference is generated between the potential of each photoconductor 72 and the potential of each primary transfer roll 64. Due to the action of the electric field formed by this potential difference, the toner image held on the outer peripheral surface of the photoconductor 72 is primarily transferred to the intermediate transfer belt 62 at the primary transfer position QA.

Further, on the outside of the intermediate transfer belt 62 (the side opposite to the drive roll 61 side), a belt cleaner 71 that comes into contact with the intermediate transfer belt 62 to clean the surface is provided. The secondary transfer roll 66 described above for secondary transfer of the toner image on the intermediate transfer belt 62 to the recording paper PA is provided on the side opposite to the opposite roll 67 side with the intermediate transfer belt 62 interposed therebetween. ..

The secondary transfer roll 66 has a structure in which a foamed elastic layer is coated around a columnar core metal (not shown). The core metal is grounded, and a potential difference is generated between the potential of the secondary transfer roll 66 and the potential of the opposing roll 67. Due to the action of the electric field formed by this potential difference, the toner image on the intermediate transfer belt 62 is secondarily transferred to the recording paper PA at the secondary transfer position QB.

On the other hand, a transport unit 79 for transporting the recording paper PA to the downstream side is provided on the downstream side of the secondary transfer position QB in the transport path 28. The transport unit 79 includes a rotatably provided transport rolls 79A and 79B and an endless transport belt 79C wound around the transport rolls 79A and 79B. The transport unit 79 is adapted to rotate the transport belt 79C by rotating the transport roll 79B by a drive means (not shown) including a motor. Further, a fixing device 80 is provided on the downstream side of the transport unit 79 in the transport path 28.

The fixing device 80 presses the fixing roll 82, which is arranged on the toner image surface side of the recording paper PA and has a heat source (for example, a halogen heater (not shown)) inside, and pressurizes the recording paper PA toward the fixing roll 82. It has a roll 84 and. Then, in the fixing device 80, the toner image is fixed to the recording paper PA by the recording paper PA entering the contact portion (nip portion) between the fixing roll 82 and the pressure roll 84 and being heated and pressed. ..

As shown in FIG. 1, a plurality of transport rolls 86 for transporting the recording paper PA on which the toner image is fixed to the paper ejection unit 15 are provided on the downstream side of the fixing device 80 in the transport path 28. Further, a toner cartridge containing yellow (Y), magenta (M), cyan (C), and black (K) toners is located above the image forming units 60Y, 60M, 60C, and 60K in the image forming unit 14. 88Y, 88M, 88C, 88K are provided interchangeably. The toner cartridges 88Y, 88M, 88C, and 88K are connected to each developing device 100 (see FIG. 2) according to each toner color, and the toner of each color is sent to each developing device 100.

Next, the image forming step in the image forming apparatus 10 will be described.

As shown in FIG. 2, when the image forming apparatus 10 is activated, image data of each color of yellow (Y), magenta (M), cyan (C), and black (K) is obtained from the image processing apparatus (not shown) or from the outside. Is sequentially output to the exposure apparatus 76.

Subsequently, the light emitted from the exposure device 76 according to the image data exposes the outer peripheral surface of the photoconductor 72 charged by the charging device 74. Then, an electrostatic charge image corresponding to the image data of each color is formed on the outer peripheral surface of the photoconductor 72. Further, the electrostatic charge image formed on the outer peripheral surface of the photoconductor 72 is developed as a toner image of each color by the developing apparatus 100. Then, the toner images of each color on the outer peripheral surface of the photoconductor 72 are primary transferred (multiple transfer) to the intermediate transfer belt 62 by the primary transfer roll 64.

On the other hand, as an example, the recording paper PA sent out from the third accommodating portion 26 and conveyed in the transport path 28 is timed with the multiple transfer of each toner image to the intermediate transfer belt 62 by the alignment roll 38. It is conveyed to the secondary transfer position QB. Then, the toner image multiplex-transferred on the intermediate transfer belt 62 is secondarily transferred by the secondary transfer roll 66 onto the recording paper PA conveyed to the secondary transfer position QB.

Subsequently, the recording paper PA on which the toner image is transferred is conveyed toward the fixing device 80 in the arrow C direction (right direction in the figure). Then, in the fixing device 80, the toner image is heated and pressed by the fixing roll 82 and the pressure roll 84 and fixed on the recording paper PA. Further, the recording paper PA on which the toner image is fixed is discharged to the paper ejection unit 15 (see FIG. 1) as an example.

As shown in FIG. 1, when an image is formed on both sides of the recording paper PA, the recording paper PA is sent to the double-sided transport path 29 after the image is fixed on the surface by the fixing device 80. Swap the front and back ends of the PA. Then, the recording paper PA is sent to the transport path 28 again to form and fix the image on the back surface of the recording paper PA.

(Developer)
Next, the developing apparatus 100 will be described.

As shown in FIG. 3, the developing apparatus 100 includes a housing 102 containing the developing agent G, a developing roll 106 (an example of a developing agent holder), and a developing agent G held on the outer peripheral surface of the developing roll 106. A trimmer 108 (an example of a layer regulating member) that regulates the thickness of the layer, a first auger 109 that supplies the developer G to the developing roll 106, and a second auger 111 that circulates and conveys the developer G together with the first auger 109. ,have.

The housing 102 includes a container main body 103 and a cover member 104 that closes the upper part of the container main body 103. Further, the housing 102 includes a developing roll chamber 122 in which the developing roll 106 is housed, a first stirring chamber 123 provided on the lower side of the developing roll chamber 122, and a second stirring chamber 124 adjacent to the first stirring chamber 123. And have.

The container body 103 has a bottom wall 103A curved at two points so as to be convex in the −Y direction when viewed in the Z direction, a mounting portion 103B formed at the end of the bottom wall 103A in the −X direction, and a bottom. It is configured to include a side wall 103C erected at the end of the wall 103A in the X direction and a partition wall 103D erected at the center of the bottom wall 103A to partition the first stirring chamber 123 and the second stirring chamber 124. Has been done.

The cover member 104 includes an upper wall 104A arranged on the second stirring chamber 124, an inclined wall 104B extending diagonally upward to the left from the end of the upper wall 104A in the −X direction and covering the developing roll chamber 122, and an inclined wall. It has a curved wall 104C, which is continuously curved at the upper end of the 104B.

The developing roll 106 is formed in a cylindrical shape and fixedly supported on the container body 103 via a shaft 106C (an example of a magnet member), and is formed in a cylindrical shape and rotatably supported on the outside of the magnet roll 106A. It has a developing sleeve 106B (an example of a rotating member). That is, the magnet roll 106A is arranged inside the developing sleeve 106B.

The magnet roll 106A is provided with a plurality of magnetic poles along the outer peripheral surface (circumferential direction), and generates a magnetic force that attracts the developer G. Specifically, the pick-up pole S2 that attracts the developer G in the rotation direction (R direction) from the lower right side near the first auger 109 when viewed in the axial direction of the shaft 106C, and the layer forming pole N1 that is arranged to face the trimmer 108. (An example of a magnetic pole having a position facing the layer regulating member), a developing electrode S1 arranged to face the photoconductor 72, a transport electrode N2 for holding the developed developer G on the outer peripheral surface of the developing sleeve 106B, and a developer. A pick-off pole S3 for peeling G from the outer peripheral surface of the developing sleeve 106B is provided.

Here, in the following description, when the magnet roll 106A is viewed in the axial direction (Z direction), the position of each magnetic pole will be described with the upper position at 12 o'clock and the lower position at 6 o'clock. As an example, the pickup pole S2 is arranged in the 4 o'clock direction, and attracts the developer G to hold it on the outer peripheral surface of the developing sleeve 106B. The layer forming electrode N1 is arranged in the 7 o'clock direction facing the tip of the trimmer 108, and a plurality of carrier CAs are held on the outer peripheral surface of the developing sleeve 106B in a state of being spiked.

The developing electrode S1 is arranged in the 9 o'clock direction facing the outer peripheral surface of the photoconductor 72. The transport electrode N2 is arranged in the 11 o'clock direction, and attracts the developer G remaining after the development to the photoconductor 72 is completed and holds it on the outer peripheral surface of the developing sleeve 106B. The pick-off pole S3 is arranged in the 2 o'clock direction, and the developer G is peeled from the developing sleeve 106B between the pickup pole S2 and the pick-off pole S3.

As an example, the developing sleeve 106B is a tubular member made of aluminum, and a cap-shaped support member (not shown) that closes both ends is attached to both ends in the Z direction, and a bearing (not shown) is inside the support member. Omitted) is fixed. By inserting the shaft 106C into this bearing, the developing sleeve 106B can rotate in the circumferential direction with respect to the magnet roll 106A. The developing sleeve 106B is rotationally driven in the + R direction by a drive unit including a motor and a gear (not shown).

Further, the developing sleeve 106B is aligned with the photoconductor 72 in the axial direction and the rotation direction (R direction) and is arranged to face the outer peripheral surface of the photoconductor 72. The developing sleeve 106B rotates in the direction opposite to the rotation direction of the photoconductor 72 (counter direction) at a position facing the photoconductor 72 (development area) and holds the developer G on the outer peripheral surface of the photoconductor 72. The static charge image of 72 is developed with the toner T. The rotation direction of the developing sleeve 106B may be forward to the rotation direction of the photoconductor 72.

On the other hand, in the first stirring chamber 123, a first auger 109 that conveys the developer G while stirring is arranged. The first auger 109 has a rotation shaft 109A arranged along the Z direction and a spiral wing portion 109B supported on the outer periphery of the rotation shaft 109A. Further, the first auger 109 is arranged to face the developing sleeve 106B on the upstream side of the trimmer 108 in the rotation direction of the developing sleeve 106B, is aligned with the developing sleeve 106B in the rotation axis direction (Z direction), and rotates the wing portion 109B. Then, the developer G is conveyed in the direction of the rotation axis, and the developer G is supplied to the developing sleeve 106B.

In the second stirring chamber 124, a second auger 111 that conveys the developer G while stirring is arranged. The second auger 111 has a rotation shaft 111A arranged along the Z direction and a wing portion 111B supported on the outer periphery of the rotation shaft 111A. Further, the second auger 111 rotates in the direction opposite to that of the first auger 109, and the developer G is circulated and conveyed together with the first auger 109.

Here, the developer G in the first stirring chamber 123 is conveyed by the rotation of the developing sleeve 106B in the R direction while being held on the developing sleeve 106B by the pickup electrode S2. The developer G held on the developing sleeve 106B enters between the outer peripheral surface of the developing sleeve 106B and the tip of the trimmer 108 to regulate the thickness of the layer, and the developing region facing the photoconductor 72 is restricted. Will be transported to.

The trimmer 108 is a plate-shaped member having the Z direction as the longitudinal direction, and is arranged along a direction in which the lateral direction is slightly inclined from the Y direction to the X direction, and the tip portion (upper end surface 108A) is a shaft. It is arranged so as to face the outer peripheral surface of the developing sleeve 106B toward the 106C side. That is, the trimmer 108 is arranged below the developing sleeve 106B in the Y direction, is arranged facing the layer forming electrode N1 via the developing sleeve 106B, and is held on the outer peripheral surface of the developing sleeve 106B. The thickness of the layer is regulated.

The magnetic force of the layer forming pole N1 arranged to face the trimmer 108 is set to 30 mT or more and 70 mT or less. By reducing the magnetic force of the layer forming electrode N1 to 70 mT or less, the binding force of the specific toner due to the magnetic force is relaxed, and the mechanical load applied to the specific toner of the developer layer is reduced. Therefore, the embedding of the external additive in the toner particles is suppressed. On the other hand, in order to secure the amount of the developer to be conveyed to the photoconductor 72, the magnetic force of the layer forming electrode N1 is set to 30 mT or more.
The magnetic force of the layer forming electrode N1 is preferably 30 mT or more and 65 mT or less, and more preferably 40 mT or more and 65 mT or less, from the viewpoint of securing the amount of the developer to be conveyed to the photoconductor 72 and suppressing the embedding of the external additive in the toner particles.

The magnetic force of the layer forming electrode N1 is measured by a Gauss meter.

The length ST of the gap between the developing sleeve 106B and the trimmer 108 (see FIG. 4) is, for example, 0.1 mm or more and 1.0 mm or less (preferably 0.2 mm or more and 0.8 mm or less). By widening the gap length ST by 0.1 mm, the mechanical load applied to the specific toner of the developer layer is further reduced. Therefore, the embedding of the external additive in the toner particles is easily suppressed. On the other hand, in order to suppress excessive transfer of the amount of the developer to the photoconductor 72, the gap length ST is set to 1.0 mm or less.

The length ST of the gap between the developing sleeve 106B and the trimmer 108 is the shortest length of the gap between the developing sleeve 106B and the tip portion 108A of the trimmer 108 facing the developing sleeve 106B.

(Static charge image developer)
Next, the static charge image developer (hereinafter, also referred to as “the static charge image developer according to the present embodiment”) housed in the developing apparatus 100 will be described in detail.

The electrostatic charge image developer according to this embodiment contains at least toner.
The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only toner or a two-component developer containing only toner and a carrier.

<Toner>
The toner has toner particles. The toner may have an external additive together with the toner particles.

(Toner particles)
The toner particles include, for example, a binder resin. The toner particles may contain a colorant, a mold release agent, other additives and the like.

-Bound resin-
As the binder resin, an amorphous polyester resin is applied.
Here, the amorphous resin is not a clear endothermic peak but has only a stepped endothermic change in the thermal analysis measurement using differential scanning calorimetry (DSC), and is a room temperature solid and has a glass transition. Refers to those that are thermoplastic at temperatures above the temperature.
On the other hand, the crystalline resin refers to a resin having a clear endothermic peak instead of a stepwise change in endothermic amount in differential scanning calorimetry (DSC).
Specifically, for example, the crystalline resin means that the half-value width of the endothermic peak when measured at a temperature rise rate of 10 ° C./min is within 10 ° C., and the amorphous resin means the half-value width. Means a resin having a temperature exceeding 10 ° C. or a resin in which a clear endothermic peak is not observed.

Examples of the amorphous polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.). , Alicyclic dicarboxylic acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). 5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butane diol, hexane diol, neopentyl glycol, etc.), alicyclic diols (eg, cyclohexanediol, cyclohexanedimethanol, etc.). Hydrogenated bisphenol A and the like), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A and the like) can be mentioned. Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

However, bisphenol A alkylene oxide adducts (bisphenol A ethylene oxide adducts, bisphenol A propylene oxide adducts, bisphenol A ethylene oxide propylene oxide adducts, etc.) are not used or used as polyhydric alcohols. Also in a small amount. Specifically, when an alkylene oxide adduct of bisphenol A is used, the amount used may be more than 0 mol% and 5 mol% or less with respect to the total polyhydric alcohol.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring the transition temperature of plastics". It is obtained by the "extra glass transition start temperature" of.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, more preferably 7,000 or more and 500,000 or less, and further preferably 30,000 or more and 50,000 or less.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed by using Tosoh's GPC / HLC-8120GPC as a measuring device, using Tosoh's column / TSKgel SuperHM-M (15 cm), and using a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The amorphous polyester resin is obtained by a well-known manufacturing method. Specifically, for example, it can be obtained by a method in which the polymerization temperature is 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the monomer. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If there is a monomer with poor compatibility, it is advisable to condense the monomer with poor compatibility in advance with the monomer and the acid or alcohol to be polycondensed, and then polycondensate with the main component. ..

The content of the amorphous polyester resin is preferably 60% by mass or more and 98% by mass or less, more preferably 70% by mass or more and 98% by mass or less, and 80% by mass or more and 98% by mass or less in proportion to the total binder resin. Is more preferable.

Here, it is preferable to use a crystalline resin together with the amorphous polyester resin. When the crystalline resin is used in combination, the hygroscopicity of the toner particles is reduced, and the embedding of the external additive in the toner particles is easily suppressed. However, the crystalline polyester resin may be used in a range of 2% by mass or more and 40% by mass or less (preferably 2% by mass or more and 20% by mass or less) with respect to the total binder resin.

Examples of the crystalline resin include known crystalline resins such as crystalline polyester resin and crystalline vinyl resin (for example, polyalkylene resin, long-chain alkyl (meth) acrylate resin, etc.). Among these, crystalline polyester resin is preferable from the viewpoint of suppressing the burial of the external additive in the toner particles.

Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, 1,10-decandicarboxylic acid). Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecanedicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc.), aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), these anhydrides, or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.). Examples thereof include anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol often has an aliphatic diol content of 80 mol% or more, preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for obtaining the melting temperature in JIS K7121-1987 "Method for measuring the transition temperature of plastics".

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

The crystalline polyester resin can be obtained by a well-known manufacturing method, as in the case of amorphous polyester, for example.

The content of the crystalline resin (preferably crystalline polyester resin) is preferably 3% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the total amount of the toner. When the content of the crystalline resin is within the above range, the embedding of the external additive in the toner particles is likely to be suppressed.

As the binder resin, an amorphous polyester resin and a binder resin other than the crystalline resin may be used in combination. However, the content of the other binder resin is preferably 10% by mass or less in proportion to the total binder resin.

Examples of other binder resins include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylic acid esters (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, etc.). N-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (eg, 2-ethylhexyl methacrylate) Acrylonitrile, methacrylonitrile, etc.), vinyl ethers (eg, vinylmethyl ether, vinylisobutyl ether, etc.), vinyl ketones (vinylmethylketone, vinylethylketone, vinylisopropenylketone, etc.), olefins (eg, ethylene, propylene, butadiene, etc.) ) Or a homopolymer of a monomer such as), or a vinyl-based resin composed of a copolymer obtained by combining two or more kinds of these monomers.
Examples of other binder resins include non-vinyl resins such as epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or coexistence of these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer below.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.

-Colorant-
Examples of colorants include carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolon orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Lissole Red, Rhodamin B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malakite green oxalate, aclysine-based, xanthene-based, azo-based, benzoquinone-based, azine-based, anthraquinone-based, thioindico-based, dioxazine-based, thiazine-based, azomethine-based, indico-based, phthalocyanine-based, aniline black Various dyes such as system, polymethine system, triphenylmethane system, diphenylmethane system, thiazole system and the like can be mentioned.
The colorant may be used alone or in combination of two or more.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds of colorants may be used in combination.

The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Release agent-
Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montanic acid esters. ; And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring the transition temperature of plastics". ..

The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Other additives-
Examples of other additives include well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles-
In the infrared absorption spectrum analysis, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.6 or less (preferably 0.5 or less, more preferably 0.48 or less). The ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.4 or less (preferably 0.3 or less, more preferably 0.2 or less).
As described above, when the polyhydric alcohol component in the amorphous polyester resin as the binder resin does not contain or contains a small amount of the alkylene oxide adduct of bisphenol A, the toner particles absorb this infrared ray. Has spectral characteristics.

On the other hand, from the viewpoint of the storage stability of the toner, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.2 or more (preferably 0.3 or more). The ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is preferably 0.05 or more (preferably 0.08 or more).

Further, from the viewpoint of the strength of the toner particles, the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 1500 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.5 or less (preferably 0.4 or less, more preferably 0.4 or less). Is preferably 0.35 or less).
On the other hand, from the viewpoint of toner storage stability, the ratio of the absorbance of wave number 820 cm ^-1 to the absorbance of wave number 1500 cm ^-1 in the infrared absorption spectrum analysis of toner particles is 0.1 or more (preferably 0.15 or more). It should be.

Here, the measurement of the absorbance of each wave number by infrared absorption spectrum analysis is measured by the following method. First, a measurement sample is prepared for the toner particles (or toner) to be measured by the KBr tablet method. Then, for the measurement sample, an infrared spectrophotometer (manufactured by JASCO Corporation: FT-IR-410) is used to integrate 300 times, and the wave number is 500 cm ^-1 or more and 4000 cm ^-1 or less under the condition of resolution 4 cm ^-1 . Measure the range of. Then, baseline correction is performed at the offset portion where there is no absorbed light, and the absorbance of each wave number is obtained.

When the weight average molecular weight is Mw (A) and the number average molecular weight is Mn (A) in the GPC measurement of the THF-soluble content of the toner particles, Mw (A) is 25,000 or more and 60,000 or less (preferably 30,000 or more and 50,000 or less, It is more preferably 32,000 or more and 48,000 or less), and Mw (A) / Mn (A) is 5 or more and 10 or less (preferably 6 or more and 8 or less, more preferably 6.2 or more and 7.8 or less).

As described above, when the toner particles satisfy the above molecular weight characteristics, even if the toner containing the amorphous polyester resin in the toner particles without using the alkylene oxide adduct of bisphenol A or using a small amount is applied, the fixing image is displayed. Fixability is improved.

The peak molecular weight of the molecular weight distribution curve obtained by GPC measurement of the THF-soluble content of the toner particles is preferably 7,000 or more and 11,000 or less, more preferably 8,000 or more and 11,000 or less, and further preferably 8200 or more and 10500 or less.
When the peak molecular weight is within the above range, the fixability of the fixed image is likely to be improved even if the toner containing the amorphous polyester resin containing the amorphous polyester resin in the toner particles without using the alkylene oxide adduct of bisphenol A or using a small amount is applied. ..

The peak molecular weight of the molecular weight distribution curve obtained by GPC measurement of the THF-soluble content of the toner particles indicates the molecular weight of the largest peak when there are a plurality of peaks in the molecular weight distribution curve.

Here, the molecular weight distribution curve, each average molecular weight, and the peak molecular weight in the GPC measurement of the THF-soluble content of the toner particles are measured as follows.
First, 0.5 mg of toner particles (or toner) to be measured are dissolved in 1 g of THF (tetrahydrofuran), ultrasonically dispersed, and then adjusted so that the concentration becomes 0.5%, and this dissolved component is added. Measured by GPC.
"HLC-8120GPC, SC-8020 (manufactured by Tosoh)" is used as a GPC device, two "TSKgel, SuperHM-H (manufactured by Tosoh 6.0 mm ID x 15 cm)" are used as columns, and THF is used as an eluent. As the experimental conditions, the experiment is carried out using a sample concentration of 0.5%, a flow velocity of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an RI (Refractive Index) detector. The calibration curve is "polystylele standard sample TSK standard" manufactured by Tosoh: "A-500", "F-1", "F-10", "F-80", "F-380", "A-2500". , "F-4", "F-40", "F-128", "F-700" 10 samples.

The toluene insoluble content of the toner particles is preferably 25% by mass or more and 45% by mass or less, more preferably 28% by mass or more and 38% by mass or less, and further preferably 30% by mass or more and 35% by mass or less.
When the toluene insoluble content of the toner particles is within the above range, the hygroscopicity of the toner particles is lowered, and the embedding of the external additive in the toner particles is easily suppressed.

Here, the toluene-insoluble component of the toner particles is a component of the toner particles insoluble in toluene. That is, the toluene insoluble component is an insoluble component containing a component of the binder resin insoluble in toluene (particularly, a high molecular weight component of the binder resin) as a main component (for example, 50% by mass or more of the whole). This toluene insoluble content can be said to be an index of the content of the crosslinked resin contained in the toner.

The toluene insoluble content shall be the value measured by the following method.
1 g of the weighed toner particles (or toner) is put into a weighed glass fiber cylindrical filter paper and attached to the extraction tube of a heated Soxhlet extractor. Then, toluene is poured into the flask and heated to 110 ° C. using a mantle heater. Further, the peripheral portion of the extraction tube is heated to 125 ° C. using a heating heater attached to the extraction tube. Extraction is performed at a reflux rate such that the extraction cycle is once in the range of 4 minutes or more and 5 minutes or less. After extraction for 10 hours, the cylindrical filter paper and toner residue are taken out, dried and weighed.
Then, the formula: toner particle (or toner) residue amount (mass%) = [(cylindrical filter paper amount + toner residue amount) (g) -cylindrical filter paper amount (g)] ÷ toner particle (or toner) mass (g) × The toner particle (or toner) residue amount (mass%) is calculated based on 100, and the toner particle (or toner) residue amount (mass%) is defined as a toluene insoluble content (mass%).
The toner particle (or toner) residue is composed of an inorganic substance such as a colorant and an external additive, a high molecular weight component of the binder resin, and the like. Further, when the toner particles contain a mold release agent, the mold release agent is a toluene-soluble component because the extraction is performed by heating.

The toluene insoluble content of the toner particles is, for example, in a binder resin, 1) a method of adding a cross-linking agent to a polymer component having a reactive functional group at the terminal to form a cross-linked structure or a branched structure, and 2) at the end. It is adjusted by a method of forming a crosslinked structure or a branched structure by polyvalent metal ions in a polymer component having an ionic functional group, 3) an extension of the resin chain length by treatment with isocyanate, a method of forming a branch, and the like.

The toner particles may be toner particles having a single layer structure, or may be toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferable that it is composed of a coated layer and.

The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

The various average particle sizes and various particle size distribution indexes of the toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman Coulter). Toner.
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using an aperture with an aperture diameter of 100 μm by the Coulter Multisizer II. Measure. The number of particles to be sampled is 50,000.
Draw a cumulative distribution of volume and number from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the particle size to be cumulative 16% is volume particle size D16v, number particle size. The particle size having a cumulative particle size of D16p and a cumulative total of 50% is defined as a volume average particle size D50v and a cumulative number average particle size D50p, and a particle size having a cumulative number of 84% is defined as a volume particle size D84v and a number particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles is obtained by (circumferential peripheral length) / (peripheral length) [(circumferential length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Sysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly emitting strobe light, and analyzing the particle image. Obtained by FPIA-3000) manufactured by the company. The number of samplings for obtaining the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

(External agent)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _Examples thereof include SiO ₂ , K ₂ O · (TiO ₂ ) n, Al ₂ O 3.2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , _Л4 and the like.

The surface of the inorganic particles as an external additive should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing the inorganic particles in the hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning active agents (for example, metal salts of higher fatty acids typified by zinc stearate, and fluoropolymers). Particles) and the like.

The amount of the external additive added is, for example, preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less with respect to the toner particles.

(Toner manufacturing method)
Next, a method for manufacturing the toner according to the present embodiment will be described.
The toner according to the present embodiment can be obtained by externally adding an externalizing agent to the toner particles after producing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method, etc.) and a wet production method (for example, an agglomeration coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The manufacturing method of the toner particles is not particularly limited to these manufacturing methods, and a well-known manufacturing method is adopted.

Then, the toner in the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like.

<Career>
The carrier is not particularly limited, and examples thereof include known carriers. As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder is impregnated with resin. Examples thereof include a resin-impregnated carrier.
The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a solution for forming a coating layer is sprayed, a kneader coater method in which a core material of a carrier and a solution for forming a coating layer are mixed in a kneader coater, and a solvent is removed.

The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Manufacturing of amorphous polyester resin>
(Preparation of amorphous polyester resin (A1))
In a three-mouthed flask with a dried inside, 60 parts by mass of dimethyl terephthalate, 74 parts by mass of dimethyl fumarate, 30 parts by mass of dodecenyl succinic anhydride, 22 parts by mass of trimellitic acid, 138 parts by mass of propylene glycol, and 0 parts of dibutyl tin oxide. .. In a nitrogen atmosphere with 3 parts by mass, the water generated by the reaction was removed from the system, reacted at 185 ° C for 3 hours, then gradually reduced in pressure to 240 ° C, and further 4 After reacting for a time, it was cooled. In this way, an amorphous polyester resin (A1) having a weight average molecular weight of 39000 was prepared.

(Preparation of amorphous polyester resin (A2))
After reacting at 190 ° C. for 3 hours, the temperature was raised to 220 ° C. while gradually reducing the pressure, and the reaction was carried out for another 2.5 hours. A polyester resin (A2) was produced. The weight average molecular weight was 26000.

(Preparation of amorphous polyester resin (A3))
Instead of 138 parts by mass of propylene glycol, 128 parts by mass of propylene glycol and 19 parts by mass of butylene glycol were used, and the mixture was reacted at 195 ° C. for 4 hours, then gradually reduced in pressure to 240 ° C. and further reacted for 6 hours. The amorphous polyester resin (A3) was prepared in the same manner as the amorphous polyester resin (A1) except for the above. The weight average molecular weight was 56000.

<Making crystalline resin>
(Preparation of crystalline polyester resin (B1))
First, 100 parts by mass of dimethyl sebacate, 67.8 parts by mass of hexanediol, and 0.10 parts by mass of dibutyl tin oxide were placed in a three-necked flask under a nitrogen atmosphere, and water generated during the reaction was removed from the system. Then, the reaction was carried out at 185 ° C. for 5 hours, the temperature was raised to 220 ° C. while gradually reducing the pressure, the reaction was carried out for 6 hours, and then the mixture was cooled. In this way, a crystalline polyester resin (B1) having a weight average molecular weight of 33700 was prepared.

The melting temperature of this crystalline polyester resin (B1) is described in JIS K7121-1987 "Method for measuring transition temperature of plastic" from the DSC curve obtained by differential scanning calorimetry (DSC). It was 71 ° C. as determined by the "melting peak temperature" of.

<Preparation of reference amorphous polyester resin>
(Reference: Preparation of amorphous polyester resin (C1))
60 parts by mass of dimethyl terephthalate, 74 parts by mass of dimethyl fumarate, 30 parts by mass of dodecenyl succinic acid anhydride, 22 parts by mass of trimellitic acid, 137 parts by mass of bisphenol A ethylene oxide adduct, and 191 parts by mass of bisphenol A propylene oxide adduct. A reference amorphous polyester resin (C1) was prepared in the same manner as the amorphous polyester resin (A1) except that the amount of dibutyltin oxide was 0.3 parts by mass. The weight average molecular weight was 27,000.

<Making toner>
(Preparation of toner (1))
73 parts by mass of amorphous polyester resin (A1), 6 parts by mass of crystalline polyester resin (B1), 7 parts by mass of colorant (CI Pigment Red 122), and mold release agent (paraffin wax, melting temperature 73). ℃, 5 parts by mass of ester wax (behenyl behenate, Unistar M-2222SL, manufactured by Nichiyu Co., Ltd.) and 2 parts by mass of ester wax (manufactured by Nippon Seikan Co., Ltd.) are put into a Henshell mixer (manufactured by Nippon Coke Industries Co., Ltd.) Then, the mixture was stirred and mixed at a peripheral speed of 15 m / sec for 5 minutes, and then the obtained stirring mixture was melt-kneaded with an extruder type continuous kneader.
Here, the setting conditions of the extruder were that the supply side temperature was 160 ° C., the discharge side temperature was 130 ° C., the supply side temperature of the cooling roll was 40 ° C., and the discharge side temperature was 25 ° C. The temperature of the cooling belt was set to 10 ° C.
After cooling the obtained melt-kneaded product, it is roughly pulverized using a hammer mill, then finely pulverized to 6.5 μm using a jet crusher (manufactured by Nittetsu Mining Co., Ltd.), and further elbow jet classifier. (Manufactured by Nittetsu Mining Co., Ltd., model: EJ-LABO) was used for classification to obtain toner particles (1). The volume average particle size of the toner particles (1) was 7.0 μm.
Then, 100 parts by mass of the toner particles (1) and 1.2 parts by mass of commercially available fumed silica RX50 (manufactured by Nippon Aerosil) as an external additive are used at a peripheral speed of 30 m using a Henshell mixer (manufactured by Mitsui Miike Machinery Co., Ltd.). Mixing was performed under the conditions of / s for 5 minutes to obtain toner (1).

(Preparation of toner (2))
The toner particles (2) were produced in the same manner as the toner particles (1) except that the amorphous polyester resin (A1) was changed to the amorphous polyester resin (A2). The volume average particle size of the toner particles (2) was 6.8 μm.
Then, the toner (2) was obtained in the same manner as the toner (1) except that the toner particles (2) were used.

(Preparation of toner (3))
The toner particles (3) were produced in the same manner as the toner particles (1) except that the amorphous polyester resin (A1) was changed to the amorphous polyester resin (A3). The volume average particle size of the toner particles (3) was 7.5 μm.
Then, the toner (3) was obtained in the same manner as the toner (1) except that the toner particles (3) were used.

(Preparation of toner (4))
The toner particles (4) were produced in the same manner as the toner particles (1) except that the number of copies of the amorphous polyester resin (A1) was changed to 79 parts by mass without using the amorphous polyester resin (B1). did. The volume average particle size of the toner particles (4) was 7.1 μm.
Then, the toner (4) was obtained in the same manner as the toner (1) except that the toner particles (4) were used.

(Preparation of reference toner (C1))
The reference toner particles (C1) were produced in the same manner as the toner particles (4) except that the amorphous polyester resin (A1) was changed to the reference amorphous polyester resin (C1). The volume average particle size of the reference toner particles (C1) was 7.7 μm.
Then, the reference toner (C1) was obtained in the same manner as the toner (1) except that the reference toner particles (C1) were used.

<Preparation of developer>
(Developers (1) to (4), Reference developer (C1))
8 parts by mass of each obtained toner and 100 parts by mass of carriers were mixed to prepare a developer (1) to (4) and a reference developer (C1), respectively.
The carriers consisted of 100 parts by mass of ferrite particles (volume average particle size: 50 μm), 14 parts by mass of toluene, and a styrene-methylmethacrylate copolymer (component ratio: styrene / methylmethacrylate = 90/10, weight average molecular weight Mw). = 80000) First, a coating liquid in which the above components excluding ferrite particles were stirred with a stirrer for 10 minutes to disperse 2 parts by mass was prepared, and then the coating liquid and the ferrite particles were mixed with a vacuum degassing type kneader (= 80000). It was obtained by putting it in a product (manufactured by Inoue Seisakusho), stirring it at 60 ° C. for 30 minutes, degassing it under reduced pressure while further heating it, drying it, and then sieving it at 105 μm.

<Examples 1 to 8, Comparative Examples 1 to 4, Reference Example>
As an image forming apparatus, an image forming apparatus "DocuCenter Color 500" adopting a two-component development method was prepared.
Then, the developing agent shown in Table 1 was housed in the developing apparatus of this image forming apparatus.
Further, in the developing apparatus of the image forming apparatus, 1) the magnetic force of the "layer forming electrode arranged opposite to the trimmer" of the magnet roll, and 2) the gap length between the developing sleeve and the trimmer (in the table, "trimmer gap length ST". Notation) was set to the value shown in Table 1.
When evaluating the embedding of the external additive in the toner particles described below, the image forming apparatus "DocuCenter Color 500" was adopted as the image forming apparatus.

<Various measurements>
For each example, the molecular weight specification of the toner particles, the infrared absorption spectral characteristics of the toner particles, and the toluene insoluble content were measured according to the methods described above. The results are shown in Table 1.

<Evaluation>
(Fixability)
Regarding the fixability, the following evaluation of high temperature offset was carried out.
The fixing temperature of the image forming apparatus was set to 220 ° C. and the image forming speed was set to 250 mm / sec. Then, 20 sheets of 100% image density images having a width of 20 mm were output in the transport direction of the paper (P paper manufactured by Fuji Xerox Co., Ltd.) by this image forming apparatus, and evaluation was performed according to the following evaluation criteria.
The evaluation criteria are as follows.
A (◎): No problem at all B (○): No problem C (△): A level where slight image defects are seen but not a problem D (×): It is judged as NG (No Good) due to the occurrence of image defects. Ru

(Embedding of external additive in toner particles)
The following evaluation was performed on the burial of the external additive in the toner particles. The evaluation was carried out in a high temperature and high humidity environment ((35 ° C., 85% environment)).
Using an image forming apparatus, 10,000 images were flown under the condition of an image density of 1%. Then, the developer was collected from the developer, and the surface of the toner particles was observed by observation with a scanning electron microscope (SEM).
The evaluation criteria are as follows.
A (◎): Toner is hardly buried B (○): Toner is slightly buried C (△): Toner is buried, but there is no problem. D (x): The external additive is buried and the surface of the toner is exposed.

Moreover, the image density at the time of outputting 10,000 sheets was measured by X-Rite No. 938.
The evaluation criteria are as follows: A (◎): Concentration is 1.5 or more B (○): 1.45 or more and less than 1.5 C (△): 1.35 or more and less than 1.45 D (×): Less than 1.35

From the above results, in the image forming apparatus of this embodiment, which uses a specific toner and the magnetic force of the "layer forming electrode arranged facing the trimmer" of the magnet roll is 30 mT or more and 70 mT or less, the magnet roll "arranged facing the trimmer". It can be seen that the embedding of the external additive in the toner particles is suppressed in a high temperature and high humidity environment as compared with the image forming apparatus of the comparative example in which the magnetic force of the “layer-forming electrode” exceeds 70 mT.
Further, it can be seen that the image forming apparatus of this embodiment has good fixing property.

The image forming apparatus of the reference example is an example in which a toner containing an amorphous polyester resin using an alkylene oxide adduct of bisphenol A is applied. Then, in the image forming apparatus of the reference example, even if the magnetic force of the "layer forming electrode arranged opposite to the trimmer" of the magnet roll exceeds 70 mT, the external additive is buried in the toner particles in a high temperature and high humidity environment. It turns out that it is difficult to do.

10 Image forming apparatus 72 Photoreceptor (example of image holder)
74 Charging device (an example of charging means)
76 Exposure device (an example of static charge image forming means)
80 Fixing device (an example of fixing means)
100 Developing equipment (an example of developing means)
106 Develop roll (an example of a developer holder)
106A Magnet roll (an example of magnet member)
106B Develop sleeve (example of rotating member)
108 Trimmer (an example of layer regulation member)
N1 layer forming electrode (an example of a magnetic pole held at a position facing a layer regulating member)

Claims (15)

Image holder and
A charging means for charging the surface of the image holder, and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
When an amorphous polyester resin is contained as the binder resin, the weight average molecular weight is Mw (A), and the number average molecular weight is Mn (A) in the gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles. Mw (A) is 25,000 or more and 60,000 or less, Mw (A) / Mn (A) is 5 or more and 10 or less, and the wave number is 1500 cm ^-1 with respect to the absorbance of the wave number 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles. The ratio of the absorptivity of is 0.6 or less, the ratio of the absorptivity of a wave number of 820 cm ^-1 to the absorptivity of a wave number of 720 cm ^-1 is 0.4 or less, and the toluene insoluble content is 28% by mass or more and 38% by mass or less. A developing means that accommodates an electrostatic charge image developer having toner containing toner particles and an external additive, and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer. A developer holder having a magnet member non-rotatably supported, a rotating member arranged around the outer periphery of the magnet member and rotating while holding the electrostatic charge image developer on the surface, and the above-mentioned A layer regulating member that regulates the layer thickness of the electrostatic charge image developer held on the surface of the rotating member is provided, and the magnet member has a plurality of magnetic poles arranged in the circumferential direction, and among the plurality of magnetic poles. A developing means having a magnetic force of a magnetic pole at a position facing the layer regulating member of 30 mT or more and 70 mT or less.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium,
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus. In the infrared absorption spectrum analysis of the toner particles, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.5 or less, and the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is The image forming apparatus according to claim 1, which is 0.3 or less. In the infrared absorption spectrum analysis of the toner particles, the ratio of the absorbance of the wave number 1500 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is 0.2 or more, and the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 720 cm ^-1 is. The image forming apparatus according to claim 1 or claim 2, which is 0.05 or more. The image formation according to any one of claims 1 to 3, wherein the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 1500 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.5 or less. Device. The image forming apparatus according to claim 4, wherein the ratio of the absorbance of the wave number 820 cm ^-1 to the absorbance of the wave number 1500 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.4 or less. The image forming apparatus according to any one of claims 1 to 5, wherein the peak molecular weight of the molecular weight distribution curve obtained by gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles is 7000 or more and 11000 or less. .. The image forming apparatus according to claim 6, wherein the peak molecular weight of the molecular weight distribution curve obtained by gel permeation chromatography measurement of the tetrahydrofuran-soluble component of the toner particles is 8000 or more and 11000 or less. The image forming apparatus according to any one of claims 1 to 7, wherein the toluene insoluble content of the toner particles is 30% by mass or more and 35% by mass or less. The image forming apparatus according to any one of claims 1 to 8 , wherein the toner particles contain a crystalline resin. The image forming apparatus according to claim 9 , wherein the content of the crystalline resin is 3% by mass or more and 20% by mass or less with respect to the total amount of the toner. The image forming apparatus according to claim 10 , wherein the content of the crystalline resin is 5% by mass or more and 15% by mass or less with respect to the total amount of the toner. The image forming apparatus according to any one of claims 1 to 11 , wherein the magnetic force of the magnetic pole having a position facing the layer regulating member is 30 mT or more and 65 mT or less. The image forming apparatus according to claim 12 , wherein the magnetic force of the magnetic pole having a position facing the layer regulating member is 40 mT or more and 65 mT or less. The image forming apparatus according to any one of claims 1 to 13 , wherein the length of the gap between the rotating member and the layer regulating member is 0.1 mm or more and 1.0 mm or less. The image forming apparatus according to claim 14 , wherein the length of the gap between the rotating member and the layer regulating member is 0.2 mm or more and 0.8 mm or less.

Images