JP4930325B2 - Image fixing method, image forming method, and image forming apparatus - Google Patents

Description

The present invention relates to an image fixing method, an image forming method, an 及 Beauty image forming apparatus.

  In the image formation in the electrophotographic process, at the time of copying, toner is attached to an electrostatic latent image formed on a photoconductor using a photoconductive substance by a magnetic brush development method or the like, and developed as a developed image. The developed image on the body is transferred to a transfer material (recording material) such as paper or sheet, and then fixed using heat, solvent, pressure or the like to obtain an image.

  As a method for fixing the toner image on the transfer material, the heat melting method is most often used. The heat melting method is roughly divided into two types, a contact type and a non-contact type. In particular, the contact-type heating roll fixing system is widely used in commercial copying machines, printers, and the like in recent years because it has high thermal efficiency and is capable of high-speed fixing. Further, in the heating roll fixing system, an induction heating system has been proposed as a means for improving the long waiting time before use, and is being put into practical use in part.

In this electromagnetic induction heating method, an endless heating belt is generally used as a heating member in addition to a heating roll. The heating belt has a thin heat resistant resin or the like as a base layer and has a smaller heat capacity than the heating roll, so that it can be heated in a shorter time than the heating roll. Furthermore, in order to prevent uneven glossiness of an image due to a temperature difference, a method has been proposed in which a metal roll is brought into contact with the peripheral surface of a pressure roll to prevent a temperature difference from being caused by heat exchange (see, for example, Patent Document 1). .
JP 2005-62554 A

The present invention, in the electromagnetic induction heating fixing method capable of heating the heating member in a short time, it is possible to suppress uneven brightness of an image for a long time, and the occurrence of stains on an image, the image fixing method, an image forming method,及 Beauty An object is to provide an image forming apparatus.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
The invention according to claim 1 is a material to be transferred, in which a pressure roll is pressed against a heating member heated by an electromagnetic induction heating method, and toner is attached to a surface of the pressure contact portion between the heating member and the pressure roll. And a fixing step of fixing the toner to the surface of the transfer material,
A metal roll in contact with the pressure roll is disposed;
The toner contains a crystalline polyester resin, a colorant, and a hydrocarbon wax as a release agent,
In the image fixing method, the surface of the metal roll is formed of a metallic substance having a thermal conductivity of 50 (W / m · K) or more.

The invention according to claim 2, wherein the toner is an image fixing method according to claim 1, wherein the content of the aliphatic crystalline polyester resin is 10 wt% or less than 2 wt%.

According to a third aspect of the present invention, there is provided a charging step for charging the surface of the image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the charged surface of the image carrier, and formation on the surface of the image carrier. The developed electrostatic latent image is developed with a developer to form a developed image, and the developed image formed on the surface of the image carrier is transferred to a transfer material, and toner is applied to the surface of the transfer material. A transfer step for attaching, and a fixing step for fixing the toner attached to the surface of the transfer material to the surface of the transfer material,
In the fixing step, a pressure roller is pressed against a heating member heated by an electromagnetic induction heating method, and a transfer material having toner adhered to the surface is passed through a pressure contact portion between the heating member and the pressure roll. And heat-fixing the toner image on the surface of the transfer material,
A metal roll in contact with the pressure roll is disposed;
The toner contains a crystalline polyester resin, a colorant, and a hydrocarbon wax as a release agent,
In the image forming method, the surface of the metal roll is formed of a metallic substance having a thermal conductivity of 50 (W / m · K) or more.

According to a fourth aspect of the present invention, there is provided an image carrier, a charging unit for charging the surface of the image carrier, an electrostatic latent image forming unit for forming an electrostatic latent image on the charged surface of the image carrier, and the image Development image forming means for developing the electrostatic latent image formed on the surface of the holding body with a developer to form a developed image, and the developed image formed on the surface of the image holding body is transferred to a transfer material and transferred Transfer means for attaching toner to the surface of the material, and fixing means for fixing the toner to the surface of the transfer material,
The fixing unit is disposed by heating a heating member heated by an electromagnetic induction heating method, and press-contacting the heating member, and passing a transfer material having toner adhered to the surface of the heating member. A pressure roll for fixing the toner image on the surface of the transfer material and a metal roll in contact with the pressure roll,
The toner contains a crystalline polyester resin, a colorant, and a hydrocarbon wax as a release agent,
In the image forming apparatus, the surface of the metal roll is formed of a metallic material having a thermal conductivity of 50 (W / m · K) or more.

According to the first aspect of the present invention, it is possible to provide an image fixing method capable of suppressing the occurrence of uneven glossiness of an image and stain on the image over a long period of time.
According to the second aspect of the present invention, the effect of uneven glossiness of an image can be more satisfactorily exhibited, and further, the image fixing capable of adjusting the charge amount under low temperature fixing and high humidity to a range suitable for development. A method can be provided.
According to the third aspect of the present invention, it is possible to provide an image forming method capable of suppressing the occurrence of uneven glossiness of an image and stain on the image over a long period of time.

According to the fourth aspect of the present invention, it is possible to provide an image forming apparatus capable of suppressing the occurrence of uneven glossiness of an image and stain on the image over a long period of time.

<Image fixing method and image fixing device>
The image fixing method of the present invention is a transfer material in which a pressure roller is pressed against a heating member heated by an electromagnetic induction heating method, and toner is adhered to a surface of the pressure contact portion between the heating member and the pressure roll. A fixing step of fixing the toner onto the surface of the transfer material, a metal roll contacting the pressure roll is disposed, and the toner includes a crystalline polyester resin, a colorant, and a release agent. And the surface of the metal roll is formed of a metallic material having a thermal conductivity of 50 (W / m · K) or more.
The image fixing apparatus according to the present invention includes a heating member heated by an electromagnetic induction heating method, a pressure member that is in pressure contact with the heating member, and a toner image that adheres to the surface of the pressure contact portion with the heating member. A pressure roll for passing the material and fixing the toner on the surface of the transfer material; and a metal roll in contact with the pressure roll. The toner comprises a crystalline polyester resin, a colorant, and a release agent. The surface of the metal roll is made of a metallic substance having a thermal conductivity of 50 (W / m · K) or more.

  As described above, as a means for shortening the waiting time before use (warm-up time), the electromagnetic induction heating method is an excellent method, and by arranging the metal roll so as to contact the pressure roll, The temperature of the pressure roll surface can be made more uniform by heat exchange, and as a result, the occurrence of uneven gloss of the image can be suppressed. However, in the method of arranging the metal roll so as to contact the pressure roll, when an image is formed over a long period of time, a part of the toner adhering to the heating belt is transferred to the pressure roll, and finally, on the metal roll. To gather. A part of the collected toner is peeled off from the metal roll, transferred to the heating roll through the pressure roll, and appears as a stain on the image.

  As a result of intensive studies, the present inventors have determined that the surface of the metal roll is thermally conductive in order to sufficiently prevent the appearance of dirt on this image and to suppress the occurrence of uneven glossiness of the image. The toner formed of a metallic substance having a rate of 50 (W / m · K) or more and further fixed on the surface of the transfer material is a toner containing a crystalline polyester resin, a colorant, and a release agent. Thus, it has been found that the toner can be kept in a low adhesive state on the surface of the metal roll and is effective. Such toner will be described later.

Here, the metallic substance in the present invention means a metal or an alloy of a plurality of metals.
The thermal conductivity of the surface of the metal roll can be measured by a method according to Fourier's law.

  When the thermal conductivity of the metallic substance forming the surface of the metal roll is 50 (W / m · K) or less, the thermal conduction is insufficient and uneven glossiness of the image occurs. The thermal conductivity is preferably 80 (W / m · K) or more, and more preferably 100 (W / m · K) or more.

Examples of the metallic substance include silver, copper, aluminum, nickel, iron, and alloys thereof, and aluminum is preferable in terms of availability and cost.
The metal roll may have any surface as long as the metallic substance is used, and the entire roll may be the metallic substance or a heat pipe. As the metal roll, a solid roll is preferable.

  In addition, when a toner that does not satisfy the requirement of containing a crystalline polyester resin, a colorant, and a release agent is used even when the metal roll is used, a pressure that is fixed by heat absorption of a transfer material during image formation is used. Since the temperature of the roll and the metal roll in contact with the pressure roll is constantly changed, the temperature of the roll surface is varied, and gloss unevenness is likely to occur.

In order to prevent the offset material from being deposited on the metal roll, which is a cause of stains on the image, the roll surface may be coated with a resin having releasability such as fluororesin (PFA) in order to make the temperature uniform. Although it is conceivable, not only the durability is lowered due to the breakage of the coating layer, but generally, such a resin is hard and it is difficult to form a thin layer, so that the effect on the temperature range is low. For this reason, the effect of suppressing the occurrence of uneven gloss is diminished.
Therefore, in order to fully exhibit the merits of the electromagnetic induction heating method, it is necessary to use a toner containing a crystalline polyester resin, a colorant, and a release agent for the outermost layer of the metal roll.

The image fixing method and the image fixing apparatus of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of the image fixing apparatus of the present invention.
An image fixing apparatus shown in FIG. 1 includes a heating belt (heating member) 1 having an endless peripheral surface, a pressure roll 2 that is in contact with the outer peripheral surface of the heating belt 1, and a back side of the heating belt 1. A pressure pad 3 that is in contact with and presses the heating belt 1 against the pressure roll 2, a pad support member 4 that supports the pressure pad 3, and the pressure pad 3 and the heating belt 1. A sliding sheet 9 having good mobility and high wear resistance, an electromagnetic induction heating device 5 that is provided along the outer peripheral surface of the heating belt 1 and that heats the heating belt 1, and both side edges of the heating belt 1 A guide member (not shown) that is in contact with the inner peripheral surface, a metal roll 7 that is in contact with the peripheral surface of the pressure roll 2 on the downstream side of the pressure contact portion between the pressure roll 2 and the pressing pad 3, and this And a peeling assisting member 8 provided in the vicinity of the outlet of the press contact portion. In the image fixing apparatus shown in FIG. 1, a belt-shaped heating member (heating belt) is used, but a roll-shaped heating member may be used. As the heating member in the present invention, a relatively free fixing machine design is allowed and the sheet peeling and other performance are excellent, the fixing temperature can be controlled, and the gloss can be further increased. A belt-like heating member (heating belt) is preferable.

  The heating belt 1 is capable of rotating in the circumferential direction (in the direction of the arrow in the figure) and basically does not come into contact with other members except at both ends in the width direction and the fixing nip. It is composed of an endless flexible belt having a thin conductive layer supported by a stretcher. As a preferable aspect of the heating belt 1, from the inside, a base layer made of a sheet-like member having high heat resistance, a conductive layer laminated on the base layer, and an elasticity that improves the fixing property and image quality of the toner image. The thing comprised from the layer and the surface mold release layer used as the uppermost layer is mentioned.

  The base layer is preferably, for example, a sheet having a thickness of 10 to 150 μm and high heat resistance, such as polyester, polyethylene terephthalate, polyethersulfone, polyetherketone, polysulfone, polyimide, polyimideamide, polyamide, and the like. And those made of high synthetic resin.

  The conductive layer is a layer that generates heat by electromagnetic induction action of a magnetic field generated by the electromagnetic induction heating device 5, and a metal layer of iron, cobalt, nickel, copper, aluminum, chrome, etc. with a thickness of about 1 to 80 μm. The formed material is used, and the material is selected so as to have a specific resistance value that allows sufficient heat generation by electromagnetic induction.

  The elastic layer covers the unfixed toner image on the recording paper at the nip and uniformly heats the toner image. For example, the rubber layer has a hardness of 10 to 30 ° (JIS K 6301, JIS A or JIS). (K 6253, durometer type A spring type) silicone rubber can be used at a thickness of 100 to 600 μm.

  Since the surface release layer is a layer in direct contact with the unfixed toner image transferred onto the recording paper, it is preferable to use a material having good release properties. Examples of the material constituting the surface release layer include tetrafluoroethylene perfluoroalkyl vinyl ether polymer (PFA), polytetrafluoroethylene (PTFE), silicon copolymer, and composite layers thereof. The surface release layer is a layer appropriately selected from these materials and provided on the uppermost layer of the belt with a thickness of 10 to 50 μm. If the thickness of the surface release layer is too thin, the durability is poor in terms of wear resistance and the life of the heating belt 1 is shortened. Conversely, if the thickness is too thick, the heat capacity of the belt increases. The warm-up will be longer.

  Although the heating belt having a four-layer structure has been described, it may be a five-layer or six-layer belt provided with an adhesive layer or a protective layer for each layer, or a three-layer belt from which an elastic layer is omitted. May be.

  As a more preferable embodiment as the heating belt 1, a polyimide having a thickness of 80 μm is used so that the base layer has a circular cross section with an inner diameter of about 30 mm in an unconstrained state, and the base layer has rigidity that does not cause buckling or the like in the width direction. It is done. The conductive layer is preferably a thin layer so that permanent deformation and cracks do not occur even when the curvature of the heating belt 1 is large, and 10 μm of copper is formed on the base layer by means such as vapor deposition or plating. Yes. On the conductive layer, a rubber hardness of 15 ° (JIS K 6301, JIS A or JIS K 6253, durometer type A spring type), a silicone rubber with a thickness of 300 μm, and a PFA with a thickness of 30 μm are further laminated. Yes.

  The surface temperature of the heating belt 1 is measured by a temperature sensitive element provided on the heating belt 1, and the temperature is controlled to be constant by the control means. There is no restriction | limiting in particular as a temperature sensing element, For example, a thermistor, a temperature sensor, etc. are mentioned.

When the heating member used in the present invention is a roll-shaped heating member (heating roll), it is necessary that at least the outermost layer has an electrical resistivity of 10 ⁻⁷ Ωm or more and less than 10 ⁻² Ωm. Here, the “at least the outermost layer” may be configured to have an electrical resistivity in the above range of the entire heating member, or only the outermost layer provided on the heating member has an electrical resistivity in the above range. It means that the structure may be included. In the present invention, the electrical resistivity is an electrical resistivity at 25 ° C.

The electrical resistivity is preferably in the range of 10 ⁻⁶ to 10 ⁻³ Ωm. It may be difficult to set the electrical resistivity to a low value of less than 10 ⁻⁷ Ωm. If the electrical resistivity exceeds 10 ⁻² Ωm, Joule heat generation by the electromagnetic induction heating method is not sufficient, and the warm-up time May not be reduced.

As a material having an electrical resistivity lower than 10 ⁻² Ωm, most of general metals and various alloys can be used. Especially common metals such as aluminum, chromium, copper, iron, magnesium, nickel, titanium, zinc, and non-metals such as silicon, carbon, phosphorus, sulfur, oxygen, chlorine, or one or two of the above metals In addition, molybdenum, tungsten, vanadium, cobalt, beryllium, bismuth, lead, tin, lithium, sodium, calcium, gallium, arsenic, strontium, zirconium, cadmium, indium, tellurium, barium, tantalum, gold, silver, etc. An alloy containing one or more metals can be used.

  Among these, it is preferable to use any one of iron, copper, and aluminum, or an alloy mainly containing any of these from the viewpoint of cost and strength, and it is particularly preferable to use iron.

  Of course, from the viewpoint of the efficiency of electromagnetic induction heating, it is desirable that the outermost layer is in the appropriate electrical resistivity range, and it is more efficient to use a magnetic material that tends to concentrate current on the surface. In many cases, it is known that by adjusting the frequency of a coil that generates an induced current, aluminum or copper having a very low electrical resistivity is sufficiently heated.

  In a fixing device using a heating roll, for example, an open magnetic circuit iron core in which a coil is concentrically wound is disposed inside a heating roll made of a metal conductor, and a high-frequency current is applied to the coil close to the inner surface of the heating roll. Inductive eddy current is generated in the fixing roll by the high-frequency magnetic field generated thereby, and the fixing roll itself is caused to generate Joule heat by the skin resistance of the fixing roll itself.

  As the above coil, all kinds of commonly used dielectric heating coils can be used, and the dielectric heating coil can be installed inside or outside the fixing roll. When installed outside the fixing roll, a demagnetizing cover for preventing heating of surrounding metal members and the like is usually used.

  The frequency of the high-frequency current flowing through the coil is preferably in the range of 1 to 100 kHz, and more preferably in the range of 10 to 80 kHz. When the frequency is less than 1 kHz, the heating may be insufficient, and when it exceeds 100 kHz, the energy loss of the heating coil may be excessive.

The pressure roll 2 may have the same configuration as the heating roll.
As a preferred embodiment of the pressure roll 2, a metal cylindrical core 2a is used as a core, an elastic layer 2b such as sponge or rubber is formed on the surface of the cylindrical core 2a, and a surface release layer 2c is further formed on the surface. And holding the heating belt 1 between the pressure roll 2 and the pressure pad 3, the pressure roll 2 is pressed against the heating belt 1, and the pressure contact portion is unfixed to the unfixed toner image. By passing the recording sheet onto which the toner image has been transferred, the unfixed toner image is fixed on the recording sheet with heat and pressure to form a fixed image.

  The pressure roll 2 is rotationally driven by a drive motor (not shown), and the heating belt 1 is driven to rotate accordingly.

  The pressing pad 3 includes an elastic member 3 b on the pedestal 3 a and presses the heating belt 1 against the pressure roll 2, and a pressure contact portion is formed between the elastic member 3 b and the pressure roll 2. The thickness of the elastic member 3b increases from the upstream side to the downstream side of the nip portion, and the surface of the elastic member 3b that is in contact with the heating belt 1 via the sliding sheet 9 is substantially the same as that of the pressure roll 2. Curved into a shape with the same curvature. When the elastic member 3b is pressed against the inner surface of the heating belt 1, the downstream portion where the thickness of the elastic member 3b increases is deformed so as to bulge to the downstream side. Thus, the heating belt 1 is deformed so as to protrude due to the frictional force acting on the downstream side in the moving direction.

  As a preferable embodiment of the pressing pad 3, a rubber hardness of 20 ° (JIS K 6301, JIS A or JIS K 6253, durometer) is used as an elastic member 3b on a base 3a made of a metal such as SUS or iron or a resin having heat resistance. A type A spring type silicone rubber is laminated.

  The sliding sheet 9 is preferably a material having good sliding properties, excellent wear resistance, and heat resistance. For example, a glass fiber sheet impregnated with Teflon (registered trademark) (Chukou Chemical Industry: FGF400- 4), and GORE-TEX (registered trademark) sheets that easily retain oil. Furthermore, a release material such as lubricating oil or lubricating grease may be applied to the inner surface of the heating belt 1. As a result, the heating belt 1 follows the pressure roll 2 and circulates at substantially the same speed as the pressure roll 2, thereby reducing the driving load of the pressure roll 2.

  The electromagnetic induction heating device 5 maintains the insulation between the exciting coil 5a to which an alternating current is applied by the exciting circuit 5d, the coil support member 5b that supports the exciting coil 5a, the coil surface, and the shape of the coil. The main part is comprised with the coil cover 5c for hold | maintaining. The electromagnetic induction heating device 5 has a central portion in the circumferential direction of the electromagnetic induction heating device 5 at a position on an axis AA connecting the centers of the pad support member 4, the nip portion and the pressure roll 2, that is, above the nip portion. The heating belt 1 is arranged at a predetermined interval so as to be positioned on the axis BB on the downstream side from a position that is substantially equidistant to the downstream side. Further, the position on the axis BB is a position that is substantially equidistant from the position where the heating belt 1 is bent with a large curvature by the elastic member 3b to the upstream and downstream sides. The coil support member 5b and the coil cover 5c cover an area of about 180 ° along the outer peripheral surface of the heating belt 1, and the exciting coil 5a covers an area of about 160 °.

  The exciting coil 5a has a continuous litz wire arranged in parallel to the width direction of the heating belt 1, and is wound around at both ends of the parallel portion. And it installs so that a predetermined space | interval may be obtained with respect to the said heating belt 1 in the state hold | maintained by pinching with the coil support member 5b and the coil cover 5c.

  The coil support member 5b is preferably made of a heat-resistant non-magnetic / insulating material. For example, heat-resistant glass, glass-containing polyethylene terephthalate, glass-containing polyphenylene sulfide, glass-containing polybutylene terephthalate, polyethersulfone, liquid crystal polymer A heat resistant resin such as is used.

  The coil cover 5c is disposed between the exciting coil 5a and the heating belt 1 in order to maintain the insulation state of the surface of the exciting coil 5a on the heating belt 1 side and maintain the shape of the exciting coil. The material may be the same as that of the coil support member 5b. However, since it is closer to the heating belt 1 that is a heating member than the coil support member, more heat resistance is required, and the distance between the electromagnetic induction heating device and the belt surface is a predetermined distance. In order to achieve the following, it is preferable that the material has a thinner thickness and is less likely to be warped or deformed even when heat is applied, and can easily maintain the shape of the coil.

  In this electromagnetic induction heating device 5, in order to strengthen the magnetic flux, a core material made of a ferromagnetic material such as ferrite may be provided in the central portion of the coil, or a heat-resistant resin or the like is used as a bobbin and the coil May be used in a state of being wound.

The excitation circuit 5d is provided in the main body of the image forming apparatus using the fixing device. When an alternating current is supplied from the excitation circuit 5d to the excitation coil 5a, a magnetic flux (H) is generated around the excitation coil 5a. Repeat extinction. The frequency of the alternating current is set to, for example, 10 to 50 kHz. In this embodiment, the frequency of the alternating current is set to 30 kHz. When this magnetic flux crosses the conductive layer of the heating belt 1, an eddy current is generated in the conductive layer so as to generate a magnetic field that hinders the change in the magnetic field, and the power (W proportional to the skin resistance of the conductive layer) = I ² R), Joule heat is generated. Thereby, the heating belt 1 is heated to a predetermined temperature.

  In this electromagnetic induction heating device 5, in order to obtain an appropriate heat generation amount by electromagnetic induction, it is preferable that the distance between the exciting coil 5a and the surface of the heating belt 1 is 2.5 mm or less. When this distance is 3 mm or more, the magnetic influence on the heating belt 1 is weakened, and in order to obtain a predetermined effective power, the current flowing through the coil increases, the coil self-heats, or the switching element of the power supply The current flowing in the current exceeds the rated current value, the element generates heat, and the power efficiency falls. Further, if the device is continuously used in such a state, the switching element of the power supply may be damaged.

  The peeling assisting member 8 is made of a thin plate-like member such as stainless steel, and is disposed so that the front end portion is in close proximity to the heating belt 1 at the exit of the nip portion, and the distance between the front end portion and the heating belt 1 is 1 mm or less. It is set to be. This peeling assisting member 8 scoops the leading edge of the recording paper that has passed through the nip and peeled off from the heating belt 1 to prevent the recording paper from being wrapped around the heating belt 1 again.

Next, the toner used in the present invention will be described.
The toner used in the present invention contains an aliphatic crystalline polyester resin, a colorant, and a release agent.
First, the aliphatic crystalline polyester resin will be described. Here, the “crystallinity” of the “crystalline polyester resin” refers to having a clear endothermic peak in the differential scanning calorimetry (DSC) instead of a stepwise endothermic change. The endothermic peak may show a peak having a width of 40 to 50 ° C. when the toner is used. In the present invention, in the case of a polymer obtained by copolymerizing other components with the main chain of the crystalline polyester, if the other components are 50% by mass or less, this copolymer is also called a crystalline polyester resin. In addition, the aliphatic crystalline polyester resin refers to a material in which any one of an acid-derived constituent component and an alcohol-derived constituent component as a raw material is aliphatic, as will be described later.
By including an aliphatic crystalline polyester resin in the toner used in the present invention, the fixing temperature can be lowered, and the effect of suppressing gloss unevenness becomes remarkable.

In the aliphatic crystalline polyester resin in the present invention, the ester concentration M of the crystalline polyester represented by the following formula 1 is preferably 0.07 ≦ M ≦ 0.09.
Formula 1: Ester concentration (M) = K / A
When the ester concentration M exceeds 0.09, the electrical resistance of the aliphatic crystalline polyester resin itself is lowered, and it may be difficult to obtain a sufficient charge amount of the toner, particularly under high humidity. On the other hand, if the ester concentration is less than 0.07, it is difficult to be compatible with the non-crystalline polyester, and it may be difficult to form toner or the toner or image may be easily broken. In Formula 1, K represents the number of ester groups in the polyester, and A represents the number of atoms constituting the polymer chain of the polyester.

  The content of the aliphatic crystalline polyester resin in the toner used in the present invention is preferably 2% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 8% by mass or less. When the content of the crystalline polyester resin is 2% by mass or more, the effect of low-temperature fixing can be satisfactorily exhibited. When the content is 10% by mass or less, the charge amount under high humidity is suitable for development. Can be adjusted to the range.

  The aliphatic crystalline polyester resin is used as a binder resin, and the content of the aliphatic crystalline polyester resin in the binder resin is preferably 4% by mass or more and 25% by mass or less. More preferably, it is 4 mass% or more and 15 mass% or less. When the amount of the crystalline resin in the total binder resin component is 4% by mass or more, the effect of low-temperature fixing can be satisfactorily exhibited. When the amount is 25% by mass or less, the charge amount under high humidity is reduced. It can be adjusted to a range suitable for development.

  The aliphatic crystalline polyester resin is a specific polyester synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. Thereafter, in the polyester resin, the component part that was an acid component before the polyester synthesis was referred to as “acid-derived component”, and the component part that was an alcohol component before the polyester synthesis was referred to as an “alcohol-derived component”. Show.

-Acid-derived components-
Examples of the acid for forming the acid-derived constituent component include various dicarboxylic acids. As the main acid-derived constituent component in the specific polyester, aliphatic dicarboxylic acids and aromatic dicarboxylic acids are desirable, and aliphatic dicarboxylic acids are particularly preferable. The acid is preferably a linear carboxylic acid.
Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc. Or lower alkyl esters and acid anhydrides thereof, but are not limited thereto. Among these, considering availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable. A dicarboxylic acid having a double bond can be suitably used in order to prevent hot offset at the time of fixing since the entire resin can be cross-linked using the double bond. Examples of such dicarboxylic acids include, but are not limited to, fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

In the present invention, an aromatic dicarboxylic acid may be copolymerized. Examples thereof include terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, among which terephthalic acid, isophthalic acid, t-butylisophthalic acid These alkyl esters are preferable in terms of availability, easy formation of easily emulsifiable polymers, and the like. The copolymerization amount is preferably from 5 to 15 mol%.
In the present specification, “constituent mol%” means that the acid-derived constituent component in the whole acid-derived constituent component in the polyester or the alcohol constituent component in the entire alcohol-derived constituent component is 1 unit (mol). Indicates the percentage.

-Alcohol-derived components-
As alcohol for becoming a component derived from alcohol, aliphatic diol is preferable, and linear aliphatic diol having a chain carbon number of 7 to 20 is more preferable.
When the aliphatic diol is branched, the crystallinity of the polyester is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. When the chain carbon number is less than 7, the melting point becomes high when polycondensation with an aromatic dicarboxylic acid, and low-temperature fixing may be difficult. On the other hand, when the chain carbon number exceeds 20, a practical material is obtained. Tends to be difficult. The chain carbon number is more preferably 14 or less.
Further, when a polyester is obtained by condensation polymerization with an aromatic dicarboxylic acid, the chain carbon number is preferably an odd number. When the chain carbon number is an odd number, the melting point of the polyester is lower than when the chain carbon number is an even number, and the melting point tends to be a value within the numerical range described later.

  Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,20-eicosanediol and the like, but are not limited thereto. Among these, ethylene glycol, 1,4-butanediol, 1,6-henquinsandiol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.

The alcohol-derived constituent component preferably has an aliphatic diol-derived constituent component content of 80 constituent mol% or more, and includes other components as necessary. As the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is more preferably 90 constituent mol% or more.
If the content of the aliphatic diol-derived constituent component is less than 80 constituent mol%, the crystallinity of the polyester is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability are deteriorated. There is a case.

  Although the monomer which can be used is enumerated above, since it is a monomer which can be obtained for industrial use and the ester concentration M of the polyester is 0.07 ≦ M ≦ 0.09, as the dicarboxylic acid component, sebacin The acid, dodecanedioic acid, tetradecanedioic acid, and diol component are selected from 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol.

-Method for producing aliphatic crystalline polyester resin-
The production method of the aliphatic crystalline polyester resin is not particularly limited, and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. For example, direct polycondensation, transesterification method, etc. Are manufactured separately depending on the type of monomer. The molar ratio (acid component / alcohol component) when the acid component and the alcohol component are reacted varies depending on the reaction conditions and the like, and cannot be generally stated, but is usually about 1/1.

The melting point of the aliphatic crystalline polyester resin thus obtained is preferably in the range of 60 to 120 ° C, more preferably in the range of 70 to 100 ° C. If the melting point is less than 60 ° C., powder aggregation tends to occur, and the storability of the fixed image may deteriorate. On the other hand, if it exceeds 100 ° C., low-temperature fixing may be difficult.
In the present invention, the melting point of the crystalline polyester is measured by using a differential scanning calorimeter (DSC), and the top of the endothermic peak when measured at a heating rate of 10 ° C./min from room temperature to 150 ° C. The value of was used.

The molecular weight is measured by GPC, but the weight average molecular weight (MW) is 10,000 to 35,000, preferably 15,000 to 30,000. When the MW is 10,000 or less, it is difficult to secure the charge amount under high humidity, and when it is 30,000 or more, the gloss is difficult to be generated when fixing at a low temperature.
-Molecular weight measurement method-
The weight average molecular weight was measured by the following method.
“HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)” apparatus was used as gel permeation chromatography (GPC), and the column was “TSKgel, SuperHM-H (manufactured by Tosoh Corporation), 6.0 mm ID × 15 cm) ”, and THF (tetrahydrofuran) was used as an eluent. The experiment was conducted using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

  The acid value of the crystalline polyester is desirably 7 to 15 mgKOH / g. In the toner of the present invention, since the combination with the amorphous resin used at the same time is important, it is selected and selected according to the acid value of the amorphous polyester to be combined. In the case of producing a toner by the emulsion aggregation method, it is desirable for production process control to produce crystalline polyester emulsified particles. When producing an emulsion, an acid value of 7 mgKOH / g or less is stable. It is difficult to obtain an emulsion. On the other hand, if the acid value is higher than 15 mg KOH / g, the acid value of the amorphous resin must be designed to be higher than that. If a resin having an excessively high acid value is used, coarse powder or A phenomenon such as an increase in the amount of fine powder tends to occur and process management becomes complicated, which is not desirable. A more preferable range is about 9 to 13 mgKOH / g. The acid value can be adjusted by changing the monomer ratio of the charged acid / alcohol.

The acid value was measured as follows. About 2 g of resin is precisely weighed and dissolved in 150 ml of tetrahydrofuran. Heat and dissolve as necessary. A few drops of a phenolphthalein indicator is added thereto, and titrated with a 0.1 mol / L potassium hydroxide ethanol solution. The point where the slight red color lasts 30 seconds is the end point. The acid value (A) is determined by the following formula.
A = B × f × 5.661 / S
A: Acid value B: Amount of 0.1 mol / L potassium hydroxide ethanol solution used for titration (ml)
f: Factor of 0.1 mol / L potassium hydroxide ethanol solution S: Amount of sample (g)

  The resin used as the binder resin together with the aliphatic crystalline polyester resin can be selected from polyester and styrene-acrylic resins, but in terms of appropriate compatibility with the crystalline resin, an amorphous polyester resin is used. preferable. Hereinafter, the amorphous polyester resin used in the present invention will be described.

  An amorphous polyester resin is also a specific polyester synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. Thereafter, in the polyester resin, the component part that was an acid component before the polyester synthesis was referred to as “acid-derived component”, and the component part that was an alcohol component before the polyester synthesis was referred to as an “alcohol-derived component”. Show.

-Acid-derived components-
Examples of the aromatic carboxylic acid component include terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, etc. Among them, terephthalic acid, isophthalic acid, t-Butylisophthalic acid and alkyl esters thereof are preferable in terms of easy availability and easy formation of an easily emulsifiable polymer.

Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc. Or lower alkyl esters and acid anhydrides thereof. Fumaric acid, maleic acid, and cyclohexanedicarboxylic acid can also be used for adjusting the glass transition point. For the purpose of adjusting the compatibility, it is preferable to use a dicarboxylic acid having a long-chain alkyl group in the side chain, such as hexenyl succinic acid, dodecenyl succinic acid, and octadecenyl succinic acid. In order to introduce a crosslinked structure, trimellitic acid, trimellitic anhydride, 1,3,5-benzenetricarboxylic acid and the like are used.
Considering the adjustment of the glass transition point of the resin and the cost, etc., based on terephthalic acid, isophthalic acid and fumaric acid, dodecenyl succinic acid, octadecenyl succinic acid, It is desirable to use trimellitic anhydride or the like as a copolymerization monomer for adjusting the degree of crosslinking.

  Examples of alcohol components include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol. Aliphatic diols such as 1,20-eicosanediol, neopentyl glycol, glycerin, alicyclic diols such as cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A, bisphenol Aromatic diols such as the propylene oxide adduct of A can be mentioned. One or more of these polyhydric alcohols can be used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and among these, aromatic diols are more preferable. In order to secure good fixing properties, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to take a crosslinked structure or a branched structure. If necessary, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can be used for the purpose of adjusting the acid value and the hydroxyl value.

The non-crystalline polyester resin can be used in any combination of the monomer components described above, for example, polycondensation (chemical doujin), polymer experimental studies (polycondensation and polyaddition: Kyoritsu Publishing) and polyester handbook (Nikkan Kogyo Shimbun). Can be synthesized by using a conventionally known method described in the company edition, etc., and a transesterification method, a direct polycondensation method, or the like can be used alone or in combination.
The amorphous polyester is desirably used in combination of two or more kinds of polyesters having different molecular weights. Explaining the case of two types as an example, it is desirable that the low molecular weight body (L body) has a weight average molecular weight of 9000 to 20000 as measured by GPC. When the molecular weight is lower than 9000, offset in the high temperature part may easily occur, and when it is 20000 or more, gloss in the low temperature part may be difficult to occur. As for a high molecular weight body (H body), a thing with a polymerization average molecular weight of 25000-55000 is desirable. When the molecular weight is 55000 or more, the gloss at the high temperature portion is difficult to be obtained, or the fixing temperature becomes high. The acid value of the resin suitable for the present invention is preferably 13 to 20 mgKOH / g for L-form and 10 to 15 mgKOH / g for H-form.

  The release agent contained in the toner used in the present invention is preferably a hydrocarbon wax. The toner used in the present invention uses a polyester resin as the binder resin. However, if the toner is too compatible with the polyester resin, the separating function from the toner as a release agent may be insufficient. It is considered that the offset of the polyester resin component tends to occur, and the component remaining on the heating roll after the offset tends to adhere to the metal roll in contact with the pressure roll. Hydrocarbon wax, which is considered to be incompatible with polyester, is easy to bleed from the toner, and even if an offset component is generated, it does not adhere to the metal roll and does not accumulate easily, so image stains are unlikely to occur. Become.

  The melting point of the hydrocarbon wax is preferably 88 ° C. or higher and 94 ° C. or lower, and more preferably 90 ° C. or higher and 92 ° C. or lower. When the melting point of the hydrocarbon wax exceeds 94 ° C., it becomes difficult to melt, and in particular, when the temperature at the time of fixing becomes lower than the setting, it may be difficult to peel off the image. Further, when the temperature is lower than 88 ° C., particularly when the temperature at the time of fixing becomes higher than a setting, the image may be difficult to peel off.

  Further, the hydrocarbon wax preferably has a molecular weight distribution (weight average molecular weight Mw / number average molecular weight Mn) of 1.5 or less, and more preferably 1.2 or less. When the molecular weight distribution of the hydrocarbon wax exceeds 1.5, the releasability may be lowered.

  Examples of the hydrocarbon wax include olefin wax, Fischer-Tropsch wax, and polyethylene wax. In the present invention, Fischer-Tropsch wax is preferable.

  The toner used in the present invention preferably contains 3% by mass or more and 15% by mass or less, and preferably contains 6% by mass or more and 12% by mass or less of a hydrocarbon wax from the viewpoint of reducing the adhesion between the toner and the medium. More preferred.

These release agents are dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, and heated with a homogenizer or pressure discharge type disperser that can be heated to the melting point or higher and subjected to strong shearing. A release agent dispersion liquid containing fine release agent particles having a particle diameter of 1 μm or less can be prepared.
The particle size of the obtained release agent particle dispersion can be measured, for example, with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).

  Examples of the colorant contained in the toner used in the present invention include dyes and pigments such as carbon black, nigrosine dye, aniline blue, calcoyl blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, and phthalocyanine. Blue, Malachite Green Oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 and the like, and magnetic materials such as magnetite and ferrite can be exemplified as typical examples. These colorants may be contained in the toner in the range of 2 to 50% by mass, but the colorants are not limited to those exemplified above.

These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used.
These colorants can be dispersed in an aqueous solvent using a polar ionic surfactant and a homogenizer as described above to prepare a colorant particle dispersion.
The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The amount of the colorant added to the toner used in the present invention is preferably in the range of 4 to 20 parts by mass with respect to 100 parts by mass of the resin contained in the toner.

  In the production of the toner used in the present invention, examples of surfactants used for emulsion polymerization, pigment dispersion, resin fine particles, release agent dispersion, aggregation, or stabilization thereof include sulfate ester salts, sulfonate salts, Anionic surfactants such as phosphate esters and soaps, cationic surfactants such as amine salts and quaternary ammonium salts, and non-polyethylene glycols, alkylphenol ethylene oxide adducts, polyhydric alcohols, etc. It is also effective to use an ionic surfactant in combination, and general means such as a rotary shear type homogenizer, a ball mill having a media, a sand mill, and a dyno mill can be used for dispersion.

  Furthermore, a charge control agent can be added to the toner used in the present invention in order to further improve and stabilize the chargeability. As the charge control agent, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used. In the first and second agglomeration processes and the fusion and coalescence process, a material that is difficult to dissolve in water is preferable in terms of controlling the ionic strength that affects the stability of the aggregated particles and reducing wastewater contamination.

  When the inorganic fine particles are added to the toner in a wet manner as the charge control agent, examples of such inorganic fine particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate. Listed are all inorganic fine particles used as agents. In this case, these inorganic fine particles can be used by being dispersed in a solvent using an ionic surfactant, a polymer acid, a polymer base or the like.

  Also, for the purpose of imparting fluidity and improving cleaning properties, after drying like normal toner, inorganic particles such as silica, alumina, titania and calcium carbonate, and resin fine particles such as vinyl resin, polyester and silicone are flow aids. As a cleaning aid, it can be added to the toner surface used in the present invention by shearing in a dry state.

The inorganic oxide fine particles added to the toner surface used in the present invention include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K. Examples include ₂ O, Na ₂ O, ZrO ₂ , CaO.SiO ₂ , Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like.

Of these inorganic oxide fine particles, silica fine particles and titania fine particles are particularly preferable. It is desirable that the surface of the inorganic oxide fine particles is previously hydrophobized. This hydrophobization treatment is more effective for improving the powder fluidity of the toner, as well as the environmental dependency of charging and the resistance to carrier contamination.
The hydrophobizing treatment can be performed by immersing the inorganic oxide fine particles in a hydrophobizing agent. Although there is no restriction | limiting in particular as said hydrophobic treatment agent, For example, a silane coupling agent, a silicone oil, a titanate coupling agent, an aluminum coupling agent etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, silane coupling agents are preferable.

  As the silane coupling agent, for example, any one of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- ( Trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane , Γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Examples thereof include propyltrimethoxysilane and γ-chloropropyltrimethoxysilane. The amount of the hydrophobizing agent varies depending on the kind of the inorganic oxide fine particles and cannot be defined unconditionally, but is usually preferably 1 to 50 parts by mass with respect to 100 parts by mass of the inorganic oxide fine particles.

Next, a method for producing a toner having a core / shell structure suitable for producing the toner used in the present invention will be described.
That is, a preferable toner production method includes a resin fine particle dispersion in which first particle fine particles having a particle diameter of 1 μm or less are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle. A first aggregating step of mixing a dispersed release agent particle dispersion to form core agglomerated particles including the first resin fine particles, the colorant particles, and the release agent particles; and the core agglomerated particles. Forming a shell layer containing second resin fine particles on the surface thereof to obtain core / shell agglomerated particles; and the core / shell agglomerated particles of the first resin fine particles or the second resin fine particles. It includes at least a fusion / unification step of fusing and uniting by heating above the glass transition temperature.

In the first aggregation step, first, a resin fine particle dispersion containing an aliphatic crystalline polyester resin, a colorant particle dispersion, and a release agent particle dispersion are prepared. The resin fine particle dispersion is prepared by dispersing the first resin fine particles prepared by emulsion polymerization or the like in a solvent using an ionic surfactant. The colorant particle dispersion is prepared by changing the colorant particles of a desired color such as black, blue, red, yellow using the ionic surfactant opposite to the ionic surfactant used in the preparation of the resin fine particle dispersion. Prepare by dispersing in solvent. In addition, the release agent particle dispersion allows the release agent to be dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base, heated above the melting point, and subjected to strong shearing. It is prepared by making fine particles with a homogenizer or a pressure discharge type disperser.
Next, the resin fine particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed, and the first resin fine particles, the colorant particles, and the release agent particles are hetero-aggregated to obtain a desired toner diameter. Aggregated particles (core agglomerated particles) having first diameters and containing first resin fine particles, colorant particles, and release agent particles are formed.

In the second aggregating step, the second resin fine particles are adhered to the surface of the core agglomerated particles obtained in the first aggregating step by using a resin fine particle dispersion containing the second resin fine particles. By forming a coating layer (shell layer) having a thickness, aggregated particles (core / shell aggregated particles) having a core / shell structure in which a shell layer is formed on the surface of the core aggregated particles are obtained. The second resin fine particles used at this time may be the same as or different from the first resin fine particles.
Further, the particle diameters of the first resin fine particles, the second resin fine particles, the colorant particles, and the release agent particles used in the first and second aggregating steps are adjusted to desired values for the toner diameter and the particle size distribution. In order to facilitate this, it is preferably 1 μm or less, and more preferably in the range of 100 to 300 nm.

  In the first aggregation step, the balance of the amounts of the two polar ionic surfactants (dispersants) contained in the resin fine particle dispersion and the colorant particle dispersion can be shifted in advance. For example, an inorganic metal salt such as calcium nitrate or a polymer of an inorganic metal salt such as polyaluminum chloride is ionically neutralized and heated below the glass transition temperature of the first resin fine particles to agglomerate the core. Particles can be made. In such a case, in the second flocculation step, the resin fine particle dispersion treated with the polar and amount dispersing agent that compensates for the deviation in the balance between the two polar dispersing agents as described above is used for the core flocculation. A core / shell aggregated particle is prepared by adding to a solution containing the particles and further heating slightly below the glass transition temperature of the core aggregated particle or the second resin fine particle used in the second aggregation step as necessary. be able to. In addition, the 1st and 2nd aggregation process may be repeatedly performed in multiple steps stepwise.

  Next, in the fusion / unification step, the core / shell aggregated particles obtained through the second aggregation step are used as a first or second resin fine particle contained in the core / shell aggregated particles in a solution. The toner is obtained by heating to above the glass transition temperature (if the resin type is two or more, the glass transition temperature of the resin having the highest glass point transition temperature), fusing and coalescence.

After completion of the fusion / unification process, the toner formed in the solution is dried through a known washing process, solid-liquid separation process, and drying process to obtain a toner.
In addition, it is preferable that the washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

  A method of using the toner used in the present invention as a two-component developer together with a carrier is also preferable. The carrier is not particularly defined, but as the core material of the carrier, for example, magnetic metals such as iron, steel, nickel, cobalt, alloys of these with manganese, chromium, rare earth, etc., and magnetic oxides such as ferrite, magnetite, etc. From the viewpoint of core surface properties and core material resistance, ferrite, particularly alloys with manganese, lithium, strontium, magnesium and the like are preferable.

  The carrier used in the present invention is preferably formed by coating the surface of the core with a resin, and the resin is not particularly limited as long as it can be used as a matrix resin, and can be appropriately selected according to the purpose. . For example, polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resins, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone Vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of organosiloxane bond or modified product thereof; polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Fluorine resin; Silicone resin; Polyester; Polyurethane; Polycarbonate; Phenol resin; Urea-formaldehyde resin, Melamine tree , Benzoguanamine resins, urea resins, amino resins such as polyamide resins, epoxy resins, per se known resins and the like. These may be used individually by 1 type and may use 2 or more types together.

  In the present invention, it is preferable to use at least a fluororesin and / or a silicone resin among the resins covering the surface of the core material. The use of at least a fluorine-based resin and / or a silicone resin as the resin for coating the surface of the core material is advantageous in that it has a high effect of preventing carrier contamination (impact) due to toner and external additives.

The image forming method of the present invention comprises a charging step for charging the surface of the image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the charged surface of the image carrier, and formation on the surface of the image carrier. The developed electrostatic latent image is developed with a developer to form a developed image, and the developed image formed on the surface of the image carrier is transferred to a transfer material, and toner is applied to the surface of the transfer material. A transfer step for adhering, and a fixing step for fixing the toner adhering to the surface of the transfer material to the surface of the transfer material. The fixing step is the image fixing method described above, The toner described above (containing a crystalline polyester resin, a colorant, and a release agent) is used.
The image forming apparatus of the present invention includes an image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the surface of the charged image carrier, and an electrostatic image formed on the surface of the image carrier. A developed image forming unit that develops a latent image with a developer to form a developed image, and a transfer unit that transfers the developed image formed on the surface of the image carrier to a transfer material and attaches toner to the surface of the transfer material. And fixing means for fixing the toner to the surface of the transfer material, wherein the fixing means is the image fixing apparatus described above, and the toner described above (crystalline polyester resin, colorant, and release agent). Containing an agent).

Hereinafter, an image forming method and an image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 2 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention. The image forming apparatus shown in FIG. 2 is an intermediate transfer type image forming apparatus generally called a tandem type, and a plurality of image forming units Y, M, C, K, a primary transfer portion (transfer means) 40 for sequentially transferring (primary transfer) each color component toner image formed by each image forming unit Y, M, C, K to the intermediate transfer belt 45; A secondary transfer portion (transfer means) 50 that collectively transfers (secondary transfer) the transferred superimposed toner image onto a sheet P that is a recording material (a transfer target material), and fixes the secondary transferred image on the sheet P. A fixing device (fixing means) 30 is provided. The fixing device 30 is an image fixing device to which the present invention described above is applied.
Moreover, it has the control part 70 which controls operation | movement of each apparatus (each part).

  Each of the image forming units Y, M, C, and K includes a charger (charging unit) 42 that charges the photosensitive drum 41 around the photosensitive drum (image holding member) 41 that rotates in the direction of arrow A, and a photosensitive member. A laser exposure device (electrostatic latent image forming means) 43 in which an electrostatic latent image is written on the body drum 41 (exposure beam is indicated by a symbol Bm in the figure), each color component toner is accommodated on the photosensitive drum 41 A developing device (toner image forming means) 44 that visualizes the electrostatic latent image with toner, and a primary transfer unit that transfers each color component toner image formed on the photosensitive drum 41 to the intermediate transfer belt 45 by the primary transfer unit 40. Electrophotographic devices such as a transfer roll 46 and a drum cleaner 47 from which residual toner on the photosensitive drum 41 is removed are sequentially arranged. These image forming units Y, M, C, and K are arranged in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 45.

The intermediate transfer belt 45, which is an intermediate transfer body, is composed of a film-like endless belt in which an appropriate amount of an antistatic agent such as carbon black is contained in a resin such as polyimide or polyamide. And the volume resistivity is formed so that it may become 10 < ⁶ > -10 < ¹⁴ > (omega | ohm) cm, The thickness is comprised by about 0.1 mm, for example. The intermediate transfer belt 45 is circulated and driven (rotated) at a predetermined speed in the direction B shown in FIG. 2 by various rolls. As these various rolls, a drive roll 61 that is driven by a motor (not shown) having excellent constant speed and rotates the intermediate transfer belt 45, and an intermediate that extends substantially linearly along the arrangement direction of the photosensitive drums 41. A support roll 62 that supports the transfer belt 45, a tension roll 63 that functions as a correction roll that applies a constant tension to the intermediate transfer belt 45 and prevents meandering of the intermediate transfer belt 45, and a backup provided in the secondary transfer section 50. A cleaning backup roll 64 provided in a cleaning unit that scrapes off residual toner on the roll 55 and the intermediate transfer belt 45 is provided.

The primary transfer unit 40 includes a primary transfer roll 46 that is disposed to face the photosensitive drum 41 with the intermediate transfer belt 45 interposed therebetween. The primary transfer roll 46 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 to 10 ^8.5 Ωcm. The primary transfer roll 46 is disposed in pressure contact with the photosensitive drum 41 with the intermediate transfer belt interposed therebetween. Further, the primary transfer roll 46 has a voltage (primary polarity) opposite to the toner charging polarity (negative polarity; the same applies hereinafter). Transfer bias) is applied. As a result, the toner images on the respective photosensitive drums 41 are sequentially electrostatically attracted to the intermediate transfer belt 45, and the superimposed toner images are formed on the intermediate transfer belt 45.

The secondary transfer unit 50 includes a secondary transfer roll 52 and a backup roll 55 arranged on the toner image carrying surface side of the intermediate transfer belt 45. The backup roll 55 is composed of a tube of EPDM and NBR blend rubber with carbon dispersed on the surface, and EPDM rubber inside. And it is formed so that the surface resistivity may be 10 ⁷ to 10 ¹⁰ Ω / □, and the hardness is set to, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd., the same shall apply hereinafter). The backup roll 55 is disposed on the back side of the intermediate transfer belt 45 to form a counter electrode of the secondary transfer roll 52, and a metal power supply roll 56 to which a secondary transfer bias is stably applied is disposed in contact with the backup roll 55. ing.

On the other hand, the secondary transfer roll 52 includes a shaft and a sponge layer as an elastic layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 to 10 ^8.5 Ωcm. The secondary transfer roll 52 is placed in pressure contact with the backup roll 55 with the intermediate transfer belt 45 interposed therebetween. Further, the secondary transfer roll 52 is grounded, and a secondary transfer bias is formed between the secondary transfer roll 52 and the backup roll 55. The toner image is secondarily transferred onto the paper P conveyed to the transfer unit 50.

  Further, on the downstream side of the secondary transfer portion 50 of the intermediate transfer belt 45, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 45 after the secondary transfer and cleans the surface of the intermediate transfer belt 45. A cleaner 65 is provided so as to be able to contact and separate. On the other hand, on the upstream side of the yellow image forming unit Y, a reference sensor (home position sensor) 72 that generates a reference signal serving as a reference for taking image forming timings in the image forming units Y, M, C, and K is provided. It is arranged. Further, an image density sensor 73 for adjusting image quality is disposed on the downstream side of the black image forming unit K. The reference sensor 72 recognizes a predetermined mark provided on the back side of the intermediate transfer belt 45 and generates a reference signal. Each image forming unit is instructed by an instruction from the control unit 70 based on the recognition of the reference signal. Y, M, C, and K are configured to start image formation.

  Further, in the image forming apparatus shown in FIG. 2, as a paper transport system, a paper tray 80 that stores paper (a material to be transferred) P, and a pickup that picks up and transports the paper P accumulated in the paper tray 80 at a predetermined timing. The roll 81, the transport roll 82 that transports the paper P fed out by the pickup roll 81, the transport chute 83 that feeds the paper P transported by the transport roll 82 to the secondary transfer unit 50, and the secondary transfer roll 52 are used as secondary. A conveyance belt 85 that conveys the sheet P conveyed after being transferred to the fixing device 30 and a fixing entrance guide 86 that guides the sheet P to the fixing device 30 are provided.

  Next, a basic image forming process of the image forming apparatus according to the present embodiment will be described. In the image forming apparatus as shown in FIG. 2, image data output from an image reading device (IIT) not shown or a personal computer (PC) not shown is subjected to predetermined image processing by an image processing device (IPS) not shown. Is applied, the image forming operation is executed by the image forming units Y, M, C, and K. In IPS, the input reflectance data is subjected to predetermined image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color editing, moving editing, and other various image editing. Is done. The image data subjected to the image processing is converted into color material gradation data of four colors Y, M, C, and K, and is output to the laser exposure device.

  The laser exposure unit 43 irradiates the photosensitive drum 41 of each of the image forming units Y, M, C, and K with, for example, an exposure beam Bm emitted from a semiconductor laser according to the input color material gradation data. Yes. In each of the photosensitive drums 41 of the image forming units Y, M, C, and K, the surface is charged by the charger 42 (charging process), and then the surface is scanned and exposed by the laser exposure unit 43, so that an electrostatic latent image is formed. Is formed (electrostatic latent image forming step). The formed electrostatic latent image is developed as a toner image of each color of Y, M, C, and K in each image forming unit Y, M, C, K (toner image forming step).

  The toner images formed on the photoconductive drums 41 of the image forming units Y, M, C, and K are transferred onto the intermediate transfer belt 45 by the primary transfer unit 40 where the photoconductive drums 41 and the intermediate transfer belt 45 abut. Is transcribed. More specifically, in the primary transfer unit 40, a voltage (primary transfer bias) having a polarity opposite to the charging polarity (minus polarity) of the toner is applied to the base material of the intermediate transfer belt 45 by the primary transfer roll 46. Primary transfer is performed by sequentially superimposing images on the surface of the intermediate transfer belt 45 (transfer process).

  After the toner images are sequentially primary transferred onto the surface of the intermediate transfer belt 45, the intermediate transfer belt 45 moves and the toner image is conveyed to the secondary transfer unit 50. When the toner image is transported to the secondary transfer unit 50, in the paper transport system, the pick-up roll 81 rotates in accordance with the timing at which the toner image is transported to the secondary transfer unit 50, and the paper of a predetermined size is transferred from the paper tray 80. P is supplied. The paper P supplied by the pickup roll 81 is transported by the transport roll 82, and reaches the secondary transfer unit 50 through the transport chute 83. Before reaching the secondary transfer unit 50, the paper P is temporarily stopped, and a registration roll (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 45 carrying the toner image, whereby the paper P And the position of the toner image are aligned.

  In the secondary transfer unit 50, the secondary transfer roll 52 is pressed against the backup roll 55 via the intermediate transfer belt 45. At this time, the sheet P conveyed at the same timing is sandwiched between the intermediate transfer belt 45 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) having the same polarity as the charging polarity (negative polarity) of the toner is applied from the power supply roll 56, a transfer electric field is formed between the secondary transfer roll 52 and the backup roll 55. Is done. The unfixed toner image carried on the intermediate transfer belt 45 is electrostatically transferred collectively onto the paper P by the secondary transfer unit 50 pressed by the secondary transfer roll 52 and the backup roll 55. (Transfer process).

Thereafter, the sheet P on which the toner image has been electrostatically transferred is transported as it is while being peeled off from the intermediate transfer belt 45 by the secondary transfer roll 52, and transported downstream of the secondary transfer roll 52 in the sheet transport direction. It is conveyed to the belt 85. The conveyance belt 85 conveys the paper P to the fixing device 30 in accordance with the optimum conveyance speed in the fixing device 30. The unfixed toner image on the paper P conveyed to the fixing device 30 is fixed on the paper P by being subjected to a fixing process with heat and pressure by the fixing device 30 (fixing step). Then, the paper P on which the fixed image is formed is conveyed to a paper discharge placement unit provided in a discharge unit of the image forming apparatus.
On the other hand, after the transfer to the paper P is completed, the residual toner remaining on the intermediate transfer belt 45 is conveyed to the cleaning unit as the intermediate transfer belt 45 rotates, and the cleaning backup roll 64 and the intermediate transfer belt cleaner 65 are transferred. Is removed from the intermediate transfer belt 45.

  Although the embodiment of the present invention has been described above, the present invention is not construed as being limited to the above-described embodiment, and it is needless to say that the present invention can be realized within a range that satisfies the requirements of the present invention. The image forming method and the image forming apparatus of the present invention can suppress the occurrence of uneven glossiness of the image and stain on the image over a long period of time.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples. In the following description, “part” means “part by mass”, and “%” means “% by mass”.

(Synthesis of non-crystalline polyester resin)
-Synthesis of non-crystalline polyester resin (A1)-
97.1 parts dimethyl terephthalate, 58.3 parts isophthalic acid, 53.3 parts dodecenyl succinic anhydride, 94.9 parts bisphenol A ethylene oxide adduct, 241 parts bisphenol A propylene oxide adduct, 0.12 parts dibutyltin oxide The mixture was stirred at 180 ° C. for 6 hours under a nitrogen atmosphere. After that, the mixture was stirred at 220 ° C. for 5 hours while reducing the pressure. When the molecular weight reached about 30000, 8 parts of trimellitic anhydride was added and further stirred for 2 hours. An amorphous polyester resin (A1) having a weight average molecular weight Mw = 45900 and a number average molecular weight Mn = 7900 was obtained. Glass transition point is 63 ° C. The acid value was 13.6 mgKOH / g.

-Synthesis of non-crystalline polyester resin (A2)-
116.5 parts of dimethyl terephthalate, 19.4 parts of isophthalic acid, 79.9 parts of anhydrous dodecenyl succinate, 158.2 parts of bisphenol A ethylene oxide adduct, 172.1 parts of bisphenol A propylene oxide adduct, 0.12 parts of dibutyltin oxide Was stirred at 180 ° C. for 6 hours under a nitrogen atmosphere. After that, the mixture was stirred at 220 ° C. for 5 hours while reducing the pressure. When the molecular weight reached about 30000, 8 parts of trimellitic anhydride was added and further stirred for 2 hours. An amorphous polyester resin (A2) having a weight average molecular weight Mw = 46100 and a number average molecular weight Mn = 7400 was obtained. Glass transition point is 60 ° C. The acid value was 13.5 mgKOH / g.

(Synthesis of crystalline polyester)
-Synthesis of crystalline polyester resin (C1)-
248 parts of tetradecanedioic acid, 118.2 parts of 1,6-hexanediol and 0.12 part of dibutyltin oxide were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred for 4 hours while reducing the pressure to obtain a crystalline polyester resin (C1) having a weight average molecular weight Mw = 25500, a number average molecular weight Mn = 10400, and an acid value of 11.5 mgKOH / g. The ester concentration was 0.091 and the melting point was 75 ° C.

-Synthesis of crystalline polyester resin (C2)-
230.3 parts of dodecanedioic acid, 160.3 parts of 1,9-nonanediol, and 0.12 part of dibutyltin oxide were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred for 4 hours while reducing the pressure to obtain a crystalline polyester resin (C2) having a weight average molecular weight Mw = 24200, a number average molecular weight Mn = 9900, and an acid value of 10.8 mgKOH / g. The ester concentration was 0.087 and the melting point was 77 ° C.

(Production of resin latex)
-Preparation of non-crystalline polyester resin latex (D1)-
After adding 120 parts of ethyl acetate and 75 parts of isopropyl alcohol to 300 parts of the amorphous polyester resin (A1), dissolving the resin at room temperature (25 ° C.), and then adding 10.4 parts of 10% ammonia water, When 1200 parts of ion-exchanged water is gradually added dropwise to the mixture, the phase is inverted and an emulsion is obtained. Ethyl acetate was distilled off to obtain an amorphous polyester resin latex (D1) having a volume average particle size of 0.17 μm.

-Preparation of non-crystalline polyester resin latex (D2)-
The production of the amorphous polyester resin latex (D1) was the same as the production of the amorphous polyester resin latex (D1) except that the amorphous polyester resin (A1) was changed to the amorphous polyester resin (A2). Thus, an amorphous polyester resin latex (D2) having a volume average particle size of 0.16 μm was obtained.

-Production of crystalline polyester resin latex (F1)-
Add 300 parts of ethyl acetate and 105 parts of isopropyl alcohol to 300 parts of crystalline polyester resin (C1), dissolve the resin at 65 ° C., and then add 15.5 parts of 10% aqueous ammonia, and then ion-exchange the mixture. When 1200 parts of water is gradually added dropwise, the phase is inverted and an emulsion is obtained. Ethyl acetate was distilled off to obtain a crystalline polyester resin latex (F1) having a volume average particle size of 0.14 μm.

-Preparation of crystalline polyester resin latex (F2)-
In the production of the crystalline polyester resin latex (F1), the volume average was obtained in the same manner as the production of the crystalline polyester resin latex (F2) except that the crystalline polyester resin (C1) was changed to the crystalline polyester resin (C2). A crystalline polyester resin latex (F2) having a particle size of 0.13 μm was obtained.

(Preparation of pigment dispersion)
The following composition was mixed and dissolved, and dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50) and ultrasonic irradiation to obtain a blue pigment dispersion having a volume average particle diameter of 150 nm.
Cyan pigment C.I. I. Pigment Blue 15: 3
(Copper phthalocyanine, manufactured by Dainippon Ink & Co., Inc.) 50 parts ・ Anionic surfactant Neogen SC 5 parts ・ Ion-exchanged water 200 parts

(Preparation of release agent dispersion (1))
The following composition was mixed, heated to 97 ° C., and then dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, it is dispersed with a gorin homogenizer (manufactured by Reiwa Shoji) and treated 20 times under the conditions of 105 ° C. and 550 kg / cm ² to form fine particles, whereby a release agent dispersion liquid having a volume average particle diameter of 190 nm (1) Got.
・ Wax (WEP-5, manufactured by NOF Corporation, melting point: 85 ° C.) 50 parts ・ Anionic surfactant Neogen SC 5 parts ・ Ion-exchanged water 200 parts

(Preparation of release agent dispersion (2))
The following composition was mixed, heated to 97 ° C., and then dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, it is dispersed with a gorin homogenizer (manufactured by Reiwa Shoji Co., Ltd.) and treated 20 times under the conditions of 105 ° C. and 550 kg / cm ² to form fine particles, whereby a release agent dispersion liquid (2) having a volume average particle size of 190 nm Got.
・ Wax (FNP090, manufactured by Nippon Seiki Co., Ltd.) 50 parts ・ Anionic surfactant Neogen SC 5 parts ・ Ion-exchanged water 200 parts

(Preparation of release agent dispersion (3))
The following composition was mixed, heated to 97 ° C., and then dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, it is dispersed with a gorin homogenizer (manufactured by Reiwa Shoji Co., Ltd.) and treated 20 times under the conditions of 105 ° C. and 550 kg / cm ² to form fine particles, whereby a release agent dispersion liquid (3) having a volume average particle diameter of 190 nm Got.
・ Wax (Carnauba) 50 parts ・ Anionic surfactant Neogen SC 5 parts ・ Ion-exchanged water 200 parts

<Example 1>
(Production of toner)
-Production of Toner (1)-
The following composition was mixed and dispersed in a round stainless steel flask with a homogenizer (manufactured by IKA, Ultra Tarrax T50), and the contents in the flask were stirred and heated to 45 ° C. while stirring the contents in the flask. Hold for a minute.
・ Amorphous polyester resin latex (D1) 400 parts ・ Crystalline polyester resin latex (F1) 50 parts ・ Ion exchange water 250 parts ・ Pigment dispersion 33.5 parts ・ Releasing agent dispersion (2) 67.5 parts・ 75 parts of 10% aluminum sulfate aqueous solution

  Thereafter, 200 g of additional amorphous polyester resin latex (D1) was added and stirred for about 30 minutes. When the obtained contents were observed with an optical microscope, it was confirmed that aggregated particles having a particle size of about 6.5 μm were formed. Adjust the pH to 7.5 with aqueous sodium hydroxide, then raise the temperature to 90 ° C, coalesce the aggregates over about 2 hours, cool, filter, and thoroughly wash with ion-exchanged water Thereafter, it was dried to obtain a toner (1). When the particle size of the electrophotographic toner (1) was measured, the volume average particle size was 6.4 μm. GSDv, which is an index of volume particle size distribution, was 1.22.

-Preparation of external additive toner (1)-
The particles of toner (1) thus obtained were treated with 0.5% hexamethyldisilazane-treated silica (average particle size 40 nm) as an external additive and treated with 50% isobutyltrimethoxysilane and metatitanic acid. The titanium compound (average particle size 30 nm) 0.7% was added (both mass ratio to the toner) and mixed for 10 minutes with a 75 L Henschel mixer, and then with a wind sieving machine high voltor 300 (manufactured by Shin Tokyo Kikai Co., Ltd.). Sieving was carried out to prepare externally added toner (1).

-Production of developer (1)-
For 100 parts of ferrite core having an average particle size of 50 μm, 0.15 parts of vinylidene fluoride and 1.35 parts of a copolymer of methyl methacrylate and trifluoroethylene (polymerization ratio 80:20) are kneaded. Coating was performed using an apparatus to prepare a carrier. The obtained carrier and the externally added toner were mixed in a ratio of 100 parts: 8 parts by a 2 liter V blender to prepare a developer (1).

(Image formation)
To remove the fixing unit of PREMAGE 355 manufactured by TOSHIBA TEC and attach an aluminum roll for temperature uniformity outside the pressure roll of this fixing unit in contact with the pressure roll, and to supply power to the fixing unit The fixing test unit (fixing device) was made. The thermal conductivity of the surface of the aluminum roll (metal roll) measured by the above-described method was 230 (W / m · K). Further, the heating member in the fixing test unit is configured to include a heat generation layer and a silicon elastic layer in a polyimide base material.

On the other hand, in order to obtain an unfixed toner image of the copy, the fixing unit of DC550 manufactured by Fuji Xerox Co., Ltd. was removed, and the copy was modified so that the copy could be discharged without fixing. Developer (1) was loaded into the developing unit of this copying machine, and an unfixed toner image was produced on J paper manufactured by Fuji Xerox Co., Ltd. using developer (1). Furthermore, the fixing test unit is mounted so that the produced unfixed toner image flows into the fixing test unit, and 10,000 images are continuously printed, and the glossiness of the image, uneven glossiness, and stains on the image and the roll are generated. Was observed. The area of the image in the paper was 5%, the temperature of the fixing device was 180 ° C., and the paper used was OK top coat paper manufactured by Fuji Xerox.
As a result, no stain was generated on the image (no occurrence), and only a slight amount of stain was adhered on the metal roll (slight metal stain was generated). The results are shown in Table 1.

Glossiness Evaluation Method A fixed image was measured three times at 60 ° gloss using a gloss meter (micro-TRI-Gloss: Gardner) to obtain an average value. The results are shown in Table 1.

Evaluation method of gloss unevenness Observe the fixed image by visual inspection, and define a case where at least one of streaky, scaly, and speckled portions is seen as being low with respect to the portion with high glossiness. "Slightly" if the low-gloss part looks slightly streaky, scaly or speckled, and if the low-gloss part doesn't see any streak, scaly or speckled “None”. The results are shown in Table 1.

<Example 2>
A toner (2) was produced and evaluated in the same manner as in Example 1 except that the composition was changed to the following composition in the production of the toner (1) in Example 1.
・ Amorphous polyester resin latex (D2) 425 parts ・ Crystalline polyester resin latex (F2) 25 parts ・ Ion exchange water 250 parts ・ Pigment dispersion 33.5 parts ・ Releasing agent dispersion (2) 67.5 parts -10% aluminum sulfate aqueous solution 75 parts As a result, no stain was generated on the image (no occurrence), and only a slight amount of stain was adhered on the metal roll (slight metal stain was generated).

<Example 3>
A toner (3) was prepared and evaluated in the same manner as in Example 1 except that the composition of the toner (1) in Example 1 was changed to the following composition.
-Non-crystalline polyester resin latex (D1) 445 parts-Crystalline polyester resin latex (F1) 5 parts-Ion exchange water 250 parts-Pigment dispersion 33.5 parts-Release agent dispersion (2) 67.5 parts -75% of 10% aluminum sulfate aqueous solution As a result, no stain was generated on the image (no generation), but there was contamination on the metal roll (many metal rolls were generated).

<Example 4>
Toner (4) was prepared and evaluated in the same manner as in Example 1 except that the composition was changed to the following composition in the preparation of toner (1) in Example 1.
-Amorphous polyester resin latex (D2) 375 parts-Crystalline polyester resin latex (F2) 75 parts-Ion exchange water 250 parts-Pigment dispersion 33.5 parts-Release agent dispersion (2) 67.5 parts -10% aluminum sulfate aqueous solution 75 parts As a result, no stain was generated on the image (no occurrence), and only a slight amount of stain was attached (metal roll stain was slightly generated).

<Comparative Example 1>
A toner (5) was produced and evaluated in the same manner as in Example 1 except that the composition was changed to the following composition in the production of the toner (1) in Example 1.
・ Amorphous polyester resin latex (D1) 425 parts ・ Crystalline polyester resin latex (F1) 25 parts ・ Ion exchange water 250 parts ・ Pigment dispersion 33.5 parts ・ Releasing agent dispersion (1) 67.5 parts -75% of 10% aqueous aluminum sulfate solution As a result, dirt was generated after about 5000 sheets on the image, and dirt was also deposited on the metal roll after printing 10,000 sheets (many metal rolls were stained).

<Comparative example 2>
A toner (6) was prepared and evaluated in the same manner as in Example 1 except that the composition of the toner (1) in Example 1 was changed to the following composition.
・ Amorphous polyester resin latex (D1) 425 parts ・ Crystalline polyester resin latex (F1) 25 parts ・ Ion exchange water 250 parts ・ Pigment dispersion 33.5 parts ・ Releasing agent dispersion (3) 67.5 parts・ 75% of 10% aqueous solution of aluminum sulfate As a result, the stain on the image and the surface of the metal roll surface were stained after 5,000 sheets were baked on the image. (Many metal roll stains occurred).

<Comparative Example 3>
A toner (7) was prepared and evaluated in the same manner as in Example 1 except that the composition of the toner (1) in Example 1 was changed to the following composition.
-Non-crystalline polyester resin latex (D1) 450 parts-Ion exchange water 250 parts-Pigment dispersion 33.5 parts-Release agent dispersion (2) 67.5 parts-10% aluminum sulfate aqueous solution 75 parts As a result, Dirt was generated after about 4000 sheets on the image, and dirt was also deposited on the metal roll after printing 10,000 sheets (many metal rolls were generated).

1 is a schematic cross-sectional view illustrating an example of an image fixing device of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating belt 2 Pressure roll 3 Press pad 4 Pad support member 7 Metal roll 8 Peeling auxiliary member 9 Sliding sheet 30 Fixing device 40 Primary transfer part 41 Photosensitive drum 42 Charger 43 Laser exposure device 44 Developer 45 Intermediate transfer belt 46 Primary transfer roll 47 Drum cleaner 50 Secondary transfer unit 70 Control unit

Claims (4)

A pressure roll is brought into pressure contact with a heating member heated by an electromagnetic induction heating method, and a transfer material having a toner adhered to the surface is passed through a pressure contact portion between the heating member and the pressure roll to pass the toner. A fixing step of fixing on the surface of the transfer material;
A metal roll in contact with the pressure roll is disposed;
The toner contains a crystalline polyester resin, a colorant, and a hydrocarbon wax as a release agent,
The image fixing method, wherein the surface of the metal roll is formed of a metallic material having a thermal conductivity of 50 (W / m · K) or more.   2. The image fixing method according to claim 1, wherein the toner has an aliphatic crystalline polyester resin content of 2% by mass or more and 10% by mass or less. A charging step for charging the surface of the image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the charged surface of the image carrier, and developing the electrostatic latent image formed on the surface of the image carrier A development image forming step of forming a developed image by developing with an agent, a transfer step of transferring the developed image formed on the surface of the image carrier to a transfer material, and attaching toner to the surface of the transfer material; A fixing step for fixing the toner attached to the surface of the transfer material to the surface of the transfer material,
In the fixing step, a pressure roller is pressed against a heating member heated by an electromagnetic induction heating method, and a transfer material having toner adhered to the surface is passed through a pressure contact portion between the heating member and the pressure roll. And heat-fixing the toner image on the surface of the transfer material,
A metal roll in contact with the pressure roll is disposed;
The toner contains a crystalline polyester resin, a colorant, and a hydrocarbon wax as a release agent,
The image forming method, wherein the surface of the metal roll is formed of a metallic material having a thermal conductivity of 50 (W / m · K) or more. An image carrier, a charging unit for charging the surface of the image carrier, an electrostatic latent image forming unit for forming an electrostatic latent image on the charged surface of the image carrier, and a static image formed on the surface of the image carrier. Development image forming means for developing an electrostatic latent image with a developer to form a developed image, and transfer for transferring the developed image formed on the surface of the image carrier to a transfer material and attaching toner to the surface of the transfer material And fixing means for fixing the toner to the surface of the transfer material,
The fixing unit is disposed by heating a heating member heated by an electromagnetic induction heating method, and press-contacting the heating member, and passing a transfer material having toner adhered to the surface of the heating member. A pressure roll for fixing the toner image on the surface of the transfer material, and a metal roll in contact with the pressure roll,
The toner contains a crystalline polyester resin, a colorant, and a hydrocarbon wax as a release agent,
The image forming apparatus, wherein the surface of the metal roll is formed of a metallic material having a thermal conductivity of 50 (W / m · K) or more.

Images