JP2015169704A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device capable of preventing toner with which an unfixed toner image is formed from being moved to a pressing member and accumulated on the pressing member.SOLUTION: A fixing device 40 includes heating means 402 which includes a heating element, an endless member to be heated 401 which comes into contact with the heating means 402 on the inner peripheral side thereof, to be heated, a pressure member 400 which is arranged to press a part of the member to be heated 401 and forms a nip part n between the pressure member 400 and the member to be heated 401, and a pressing member 403 which is provided in a position facing the heating means 402 across the member to be heated 401 and presses the member to be heated 401 to the side of the heating means 402 and conveys a recording material Pa carrying the unfixed toner image formed with the toner to the nip part n, to fix the unfixed toner image to the recording material Pa. The outermost layer of the pressing member 403 contains a fluoropolymer. The contact angle of the surface of the pressing member 403 with respect to silicone oil at room temperature is 30° to 50°.

Description

  The present invention relates to a fixing device and an image forming apparatus.

  In an image forming apparatus such as a copying machine, a printer, a facsimile machine, a printing machine, or a combination of these, a visible image such as a toner image carried on a latent image carrier is electrostatically transferred onto a recording material such as a recording sheet. Get image output. The toner image on the recording material is fixed on the recording material by melting and permeating action due to heat and pressure when passing through the fixing device. In recent years, market demands for energy saving and high speed have been increasing for such image forming apparatuses such as printers, copiers, and facsimiles.

  In an image forming apparatus, an unfixed toner image is transferred to a recording material sheet, printing paper, photosensitive paper, electrostatic recording paper, etc. by an image transfer method or a direct method by an image forming process such as electrophotographic recording, electrostatic recording, and magnetic recording. Formed on recording material. As a fixing device for fixing the unfixed toner image, a contact heating method fixing device such as a heat roller method, a film heating method, and an electromagnetic induction heating method is widely used. Here, in the heat roller fixing method, a fixing nip portion is configured by including a heating roller using a halogen lamp or the like as a heat generation source and a pressure roller facing and abutting thereto. In the film fixing method, a film having a smaller heat capacity than the roller itself is used as the heating member. The electromagnetic induction heating method is known as a fixing device that generates heat when a high frequency voltage of a high frequency power source is applied to a high frequency induction heating device.

An example of a belt-type fixing device is described in Patent Document 1, for example, and an example of a surf fixing (film fixing) fixing device using a ceramic heater is described in Patent Document 2.
Here, the surf fixing device is configured as shown in FIG. 8, for example. The fixing device includes a pressure roller 100 and a fixing belt 101, and the fixing belt 101 is heated by a heating unit 102 located on the inner peripheral side of the fixing belt 101. A nip portion is formed by the fixing belt 101 and the pressure roller 100, and an image is fixed by inserting the recording material 105 through the nip portion. The surf fixing device can realize a fixing device that is inexpensive and has a fast warm-up.

  In recent years, it has been desired for the fixing device to further shorten the warm-up time and the first print time. Here, the warm-up time is a time required from a normal temperature state to a predetermined printable temperature (a reloaded reload temperature after heating) such as when the power is turned on. The first print time is the time from when a print request is received to when the print operation is performed through the print preparation and the paper discharge is completed. As a method for solving the shortening of the warm-up time and the first print time, a surf fixing method using a ceramic heater has been proposed. By this method, compared with a belt-type fixing device, it is possible to reduce the heat capacity and reduce the size, shorten the rise time, and reduce the preheating power (for example, Patent Document 2).

However, until now, even if the image of each area on the recording material is different, the fixing device determines the control temperature of each heating area as the same image. Therefore, the control temperature of the heating area is determined so that sufficient fixing is possible in the area on the recording material that requires the most fixing energy. For this reason, in the area on the recording material in the image area where relatively little fixing energy is required, the recording material and the toner are excessively heated, and there is a problem that wasteful energy is consumed.
Therefore, it has been proposed to use a contact-type divided heater in order to supply an appropriate amount of heat to each area on the recording material in the image area according to the image (for example, Patent Document 3).

When this divided heater is used, since the endless belt is directly heated by the divided heater, energy saving is high, and it is possible to further shorten the first print time from the heating standby time. In addition, the heating element of the divided heater, which is a heating means, has a planar shape and directly heats the member to be heated (fixing belt).
On the other hand, in order to efficiently transfer heat to the member to be heated, it has been reported that a pressing member is installed at a position facing the heating element (heater) via the member to be heated (for example, Patent Document 4). The pressing member maintains good contact between the member to be heated and the heater.

However, when an unfixed image formed of toner is continuously passed through the fixing device, a new problem occurs that a large amount of toner adheres to the surface of the pressing member. In the above-described fixing device in which the fixing belt is heated by being pressed against a resistance heating element (heater) with a pressure roller from the outside, the toner that could not be fixed on the paper, and the paper powder received from the paper, It adheres to the pressure roller and the pressure roller. The paper dust and toner adhering to the fixing belt and the pressure roller are transferred to the paper passing through the nip portion and cleaned after the next round, but the pressing roller has a contact member other than the fixing belt. It does not exist, and it is thought that paper dust and toner are accumulated to form a solid matter as a lump.
The fixing of the toner to the pressing member forms irregularities on the surface of the pressing member, hinders the contact between the heating element and the heated member, and causes the heating element to overheat or break. Further, the accumulated toner melts and contaminates the fixed image, or the toner is peeled off from the pressing member during the cold rotation (starting up), and the inside of the fixing device and the image forming apparatus main body is soiled.

From the viewpoint of adhesion of toner to such a member, there has been a so-called hot offset phenomenon that causes toner to adhere to a heated member, and a release layer such as a fluororesin is provided on the surface layer to prevent this phenomenon. Many attempts have been made.
However, even if a release layer such as a fluororesin is provided, it does not necessarily prevent the toner forming an unfixed toner image from moving to the pressing member and accumulating in the pressing member. Was desired.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing device that can prevent toner forming an unfixed toner image from moving to a pressing member and accumulating in the pressing member. And

  In order to solve the above problems, the present invention provides a heating means having a heating element, an endless heated member that is in contact with the heating means on the inner peripheral side and is heated, and a part of the heated member. A pressure member that is disposed so as to be able to be pressed and forms a nip portion with the heated member; and is provided at a position facing the heat generating means with the heated member sandwiched between the heated member and the heated member. A fixing device that includes a pressing member that presses toward the heat generating unit, conveys a recording material carrying an unfixed toner image formed of toner to the nip portion, and fixes the unfixed toner image on the recording material. The outermost layer of the pressing member contains a fluorine-based polymer, and the contact angle at normal temperature with respect to the silicone oil on the surface of the pressing member is 30 ° to 50 °. And

  According to the present invention, it is possible to provide a fixing device that can prevent toner forming an unfixed toner image from moving to the pressing member and accumulating in the pressing member.

1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. 1 is a schematic diagram illustrating an example of a fixing device of the present invention. FIG. 6 is a schematic view showing another example of the fixing device of the present invention. It is explanatory drawing which shows an example of the image formation pattern which consists of an image part and a non-image part. It is explanatory drawing which shows the other example of the image formation pattern which consists of an image part and a non-image part. 6 is a graph illustrating an example of a fixing temperature of a fixing member corresponding to an image portion and a non-image portion. It is the schematic which shows an example of a heat-emitting means. FIG. 10 is a schematic diagram illustrating another example of a fixing device.

  The present invention is arranged such that a heating means 402 having a heating element, an endless heated member 401 that is in contact with the heating means 402 on the inner peripheral side and heated, and a part of the heated member 401 can be pressed, The pressure member 400 that forms the nip portion n between the heated member 401 and the heated member 401 is provided at a position facing the heated member 402, and the heated member 401 is placed on the heated member 402 side. The fixing device 40 includes a pressing member 403 that presses the recording material Pa carrying an unfixed toner image formed of toner to the nip portion n and fixes the unfixed toner image on the recording material Pa. The outermost layer of the pressing member 403 includes a fluorine-based polymer, and the contact angle of the surface of the pressing member 403 with the silicone oil at room temperature is 30 ° to 50 °.

  Hereinafter, a fixing device and an image forming apparatus according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

(Image forming device)
An image forming apparatus provided with the fixing device of the present invention is shown in FIG. Note that the present invention is not limited to the apparatus of the embodiment shown in FIG. 1, and is intended not only for producing a single color image but also for forming a color image.

  In the image forming apparatus 1 of FIG. 1, a printing unit 460 is disposed in the center of the apparatus main body 450, and the paper feeding unit 4 is disposed below the printing unit 460. Disposed on the side of the printing unit 460 is a discharge tray (discharge storage unit) 430 for discharging a recording medium (hereinafter referred to as a recording material) Pa on which an image is formed, and a writing unit 440 on the upper side. ing.

  In the printing unit 460, the apparatus main body 450 rotatably supports an electrophotographic photosensitive member (hereinafter simply referred to as a photosensitive member) 8 that is a rotating member in the center of the apparatus body 450. The photoconductor 8 is an example of an image carrier and has a drum shape. Around the photosensitive member 8, a charging device 18 including a charging roller, a writing unit 440, a developing device 22, a transfer device 10, a cleaning unit 24, and the like are sequentially arranged along a rotation direction indicated by an arrow in the drawing. .

Here, the developing device 22 visualizes the electrostatic latent image on the photoreceptor 8 with the developer carried on the developing roller 22a.
The cleaning unit 24 includes a blade 24 a that is in sliding contact with the peripheral surface of the photoreceptor 8 and removes untransferred toner.
The writing unit 440 is disposed above the photosensitive member 8 and irradiates the exposure position 150 between the charging device 18 and the developing roller 22a with the exposure light Lb corresponding to the image information from the control unit 50 that has received the document image information. It is designed to scan. Here, the mirrors 201 and 202 are used to guide the exposure light Lb to the exposure position 150.

  A position where the transfer device 10 faces the lower surface of the photoconductor 8 is set as a transfer portion N, and this transfer portion N is a position where the toner image is transferred to the recording material Pa. A pair of registration rollers 6 is provided on the upstream side (right side of the paper surface) in the paper feeding direction from the transfer portion N. A sheet feeding unit 4 is provided below the registration roller 6. A plurality of paper feed trays 14 are provided in the paper feed unit 4, and each sheet feed tray 14 stores sheet-like recording materials Pa such as transfer papers having different sizes and paper qualities so as to be selectively fed and stored in a stacked state. The

The paper feed unit 4 includes a paper feed roller 16 and the like, and the recording material Pa accommodated therein is separated one by one from the top by the paper feed roller 16 and sent out. The recording material Pa sent out by the paper feed roller 16 is temporarily stopped by the pair of registration rollers 6 to correct the posture deviation. Thereafter, the pair of registration rollers 6 is synchronized with the rotation of the photosensitive member 8, that is, when the leading end of the toner image formed on the photosensitive member 8 coincides with the predetermined position of the leading end of the recording material Pa in the conveyance direction. Is sent to the transcription site N.
The fed recording material Pa is conveyed to the pair of registration rollers 6 while being guided by the conveyance guide and conveyance roller group 120.

  A fixing device 40 is arranged at a position downstream of the transfer device 10 in the paper feeding direction in the printing unit 460 of FIG. A branching claw 38 is provided in the sheet discharge path downstream of the fixing device 40 in the sheet feeding direction, and this is switched so that the recording material Pa is sent to the automatic duplexer 39 through the branch path below the sheet discharge tray 430 side when performing duplex recording. It is done. The automatic double-side device 39 is disposed so that the recording material Pa from the branch path is reversed by turn-back conveyance, and the recorded recording surface faces downward and is re-fed to the transfer portion N.

  Image formation in the present embodiment is generally performed as follows. First, the photoconductor 8 starts rotating on the printing unit 460 side in the center of the apparatus, and the photoconductor 8 is uniformly charged by the charging device 18 in the dark during the rotation. Further, the exposure apparatus 440 irradiates and scans the exposure light Lb corresponding to the image to be produced according to the input image information, so that an electrostatic latent image corresponding to the image to be produced (hereinafter referred to as a latent image). Are formed on the photoconductor 8. When the latent image comes close to the developing device 22 by the rotation of the photoconductor 8, the latent image is visualized by the toner and becomes a toner image carried on the photoconductor 8.

On the other hand, in the paper feed unit 4 at the lower part of the apparatus, the recording material Pa is sent out by the paper feed roller 16 of one of the paper feed trays 14. For example, the sheet is conveyed to the position of the pair of registration rollers 6 through a predetermined conveyance path as indicated by a broken line in FIG. The registration roller 6 temporarily stops the recording material Pa, and sends the toner image on the photoconductor 8 toward the transfer device 10 at a timing such that the transfer device 10 faces a predetermined position of the recording material Pa.
The toner image on the photoconductor 8 and the predetermined position of the recording material Pa to which the toner image is to be transferred coincide with each other at the transfer portion N, and the toner image is transferred onto the recording material Pa by the transfer electric field generated by the transfer device 10. Is sucked and transferred. The recording material Pa to which the toner image has been transferred is sent out toward the fixing device 40. Then, the toner image on the recording material Pa is heated and pressurized while passing through the fixing device 40 to be fixed on the recording material Pa, and then the recording material Pa is discharged onto a discharge tray 430.

  Further, when forming an image on both sides of the recording material Pa, the recording material Pa discharged to the automatic duplex device 39 by the switchable branch claw 38 is switched back by the automatic duplex device 39, and before the registration roller 6. It is transported to the transport path.

The recording material Pa conveyed from the transfer portion N while holding an unfixed image is sent to the fixing device 40 and subjected to fixing processing.
The residual toner remaining on the photosensitive member 8 without being transferred at the transfer portion N reaches the cleaning unit 24 along with the rotation of the photosensitive drum 8, and is cleaned from the photosensitive member 8 while passing through the cleaning unit 24. It is removed, and the next image formation can be performed. Thereafter, the residual potential on the photosensitive drum 8 is removed by a neutralizing unit (not shown), and is prepared for the next image forming process.

(Fixing device)
<First Embodiment>
FIG. 2 shows the fixing device 40 according to the first embodiment. The fixing device 40 is disposed so as to be able to press a heating unit 402 having a heating element, an endless heated member 401 that is in contact with the heating unit 402 on the inner peripheral side, and to be heated, and a part of the heated member 401. The pressure member 400 that forms a nip portion between the heated member 401 and the heated member 401 is provided at a position facing the heated member 402, and the heated member 401 is placed on the heated member 402 side. And a pressing member 403 for pressing.

  A heat generating means 402 that generates heat when energized is disposed on the inner peripheral side of the member to be heated 401. The heat generating means 402 can be a ceramic heater, a thermal head, or the like. By raising the temperature of the heated member 401 with the heat generated by the heat generating means 402, the unfixed image on the recording material Pa conveyed to the fixing nip n is heated and fixed.

  As shown in FIG. 2, the fixing device 40 includes a pressure member 400 that is a pressure roller, a heated member 401 at an upper portion thereof, and a pressing member (pressing roller) 403 disposed above the heated member 401. Have In FIG. 2, the conveyance direction of the recording material Pa indicated by the arrow is reversed from that in FIG. 1. Further, on the inner peripheral side of the member to be heated 401, the heat generating means 402 is disposed at a position facing the pressing member 403, and the support member 405 is disposed at a position facing the pressing member 400.

  The fixed support member (stay) 405 is a substantially square bar-like member that is pressed by the pressure member 400 and supports the fixing nip n so as to form a flat surface, and penetrates the inside of the heated member 401. Thus, both ends are supported by the frame of the fixing device 40. The support member 405 is provided with a pressure pad 406 that forms a plane for forming the fixing nip n. By attaching the pressure pad 406 that is a pressure member integrally with the support member 405, it is possible to prevent the pressure pad 406 from being bent when receiving pressure from the pressure member 400 via the member to be heated 401. This makes it possible to obtain a uniform nip width in the axial direction of the heated member 401 (the direction perpendicular to the paper surface).

In the fixing device 40 according to the present embodiment, the heated member 401 is used as an endless fixing belt, but is not limited thereto, and can be used as a fixing roller.
The member to be heated 401 has a base and an elastic layer coated on the surface of the base. As the substrate, a metal such as nickel or SUS can be used, and as the elastic layer, a resin such as silicone rubber or polyimide can be used. The member to be heated 401 can be configured to include, for example, a SUS base having an outer diameter of 30 mm and a thickness of 20 to 40 μm, and an elastic layer formed of silicone rubber having a thickness of about 50 to 200 μm. The heated member 401 is preferably an endless belt (or film). The surface layer of the belt preferably has a release layer having a thickness of 5 to 30 μm, such as a PFA or PTFE layer, and can have release properties so that toner does not adhere.
PFA represents a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, and PTFE represents polytetrafluoroethylene.

  There may be an elastic layer formed of a silicone rubber layer or the like between the substrate of the member to be heated 401 and the PFA or PTFE layer. In the absence of the silicone rubber layer, the heat capacity is reduced, and the fixability of the recording material Pa at the lower fixing nip n, which is the clamping position of the pressure member (pressure roller) 400 and the support member 405, is improved. However, when the unfixed image is crushed and fixed, minute irregularities on the surface of the belt are transferred to the image, and there is a problem that a crusty glossy unevenness (skin skin image) remains on the solid portion of the image. In order to improve this, it is preferable to provide a silicone rubber layer of 100 μm or more. Due to the deformation of the silicone rubber layer, fine irregularities are absorbed and the skin image is improved.

  A support member 405 for supporting the fixing nip n is installed at a position below the heated member 401 and is connected to an external member (not shown) to support the heated member 401. The upper position of the heated member 401 is directly heated by the heating means 402 from the inner peripheral side. On the other hand, the recording material Pa is pressed and heated and fixed at the position of the fixing nip n that is the holding position between the pressing member 400 that is the pressing roller at the lower position and the support member 405.

  The fixing device 40 according to the present embodiment is an embodiment where a pressure roller is used as the pressure member 400. In the pressure member 400 that is a pressure roller, a pressure elastic layer 413 is formed on a hollow cored bar 412. The pressing member 400 is rotated by a driving force from a driving source (not shown) such as a motor provided in the image forming apparatus, and is pressed against the heated member 401 by a spring or the like as an urging means (not shown). Yes. As a result, the elastic layer and the pressure elastic layer 413 of the heated member 401 are crushed and deformed to form a predetermined nip width. For the pressure elastic layer 413 of the pressure member 400, foamable silicone rubber, silicone rubber, fluorine rubber, or the like can be used. In order to improve the releasability, it is preferable to provide a thin release layer made of PFA, PTFE or the like on the surface layer of the pressure elastic layer 413.

  The pressure member 400 may be a hollow roller or may have a heating source such as a halogen heater inside the roller. The pressure elastic layer 413 may be solid rubber, but if there is no heater inside the pressure roller, sponge rubber may be used. Sponge rubber is more desirable because it increases heat insulation and makes it difficult for the heated member 401, which is a fixing belt, to be deprived of heat.

Next, the pressing member 403 in the fixing device 40 according to the present embodiment will be described.
In order to maintain a good contact state between the heat generating means 402 and the heated member 401, a pressing member 403 is installed at a position facing the heat generating means 402 with the heated member 401 interposed therebetween. In this embodiment, a case where a pressing roller is used as the pressing member 403 is cited.

The pressing member 403 can be configured to include, for example, an iron cored bar 410 having an outer diameter of φ15 to 30 mm and an inner diameter of about φ8 mm, and an elastic layer (pressing elastic layer 411) covered on the surface of the cored bar 410. The pressing elastic layer 411 can be made of a material such as foamable silicone rubber, silicone rubber, or fluororubber, and can have a thickness of, for example, 3.5 mm to 11 mm. Among these, foamed silicone rubber is particularly preferable from the viewpoint of heat insulation. The thermal conductivity of foamed silicone rubber or the like is preferably 0.1 to 0.2 W / (m · K) and the hardness is 35 to 60 ° (Asker C) and the cell diameter is 5 to 100 μm.
In addition, a release layer having a thickness of about 10 to 40 μm is preferably formed on the surface of the elastic layer in order to improve the release property.

  The pressing member 403 is provided at a position facing the heat generating means 402 with the heated member 401 interposed therebetween, and presses the heated member 401 toward the heat generating means 402 by an urging means (not shown). Thereby, a nip portion is formed, and heat from the heat generating means 402 is transmitted to the heated member 401. Also, by setting the properties (thermal conductivity, hardness, cell system, etc.) of foamed silicone rubber, etc. within the above range, high heat resistance and excellent heat insulation can be obtained and supplied from the resistance heating element to the fixing belt The amount of heat generated can be reduced, shortening the start-up of equipment and saving energy.

  The present invention is characterized in that the contact angle at normal temperature with respect to the silicone oil on the surface of the pressing member is defined within a specific range, and by setting the contact angle to 30 ° to 50 °, toner adhesion to the pressing member can be suppressed. It is possible, More preferably, it is 40 degrees-49 degrees. When the contact angle is less than 30 °, the toner resin tends to wet and spread on the surface of the pressing member, and the toner fixation deteriorates. On the other hand, toner adhesion tends to deteriorate even if the angle exceeds 50 °. Although the detailed cause is unknown, it seems to be caused by the wax contained in the toner. If the wax adheres to the pressing member, the adhesion of the toner resin is considered to be suppressed, and it is estimated that a certain amount of the wax adheres effectively to prevent the toner adhesion.

  When the contact angle on the surface of the pressing member satisfies the above range, toner adhesion to the pressing member 403 can be suppressed, so that the toner forming the unfixed toner image passes through the heated member 401. Transition to the pressing member 403 and accumulation in the pressing member 403 can be prevented. In addition, it is possible to prevent the heat generating body 408 from being damaged in the heat generating means 402 due to toner adhering to the pressing member 403 and accumulating. Further, it is possible to suppress the occurrence of an abnormal image that occurs due to the toner adhering to the pressing member 403 and accumulated on the recording material via the heated member 401 again.

Silicone oil is used to measure the contact angle. The contact angle here means a contact angle measured using a straight silicone oil, particularly dimethyl silicone oil, as the silicone oil. Moreover, Shin-Etsu Chemical Co., Ltd. KF-968-100CS can be used as a commercial item of dimethyl silicone oil.
The method for measuring the contact angle is as follows. 3 μL of silicone oil is dropped on the surface of the pressing member at room temperature from a dispenser of an automatic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., Dorop Master-500). The formed angle is calculated by the θ / 2 method. The contact angle is measured once for one drop of silicone oil as one set, and this is repeated 5 sets, and the average value of the obtained contact angles is used.

  As described above, the pressing member 403 can be configured to include a cored bar 410 and a plurality of layers such as a pressing elastic layer 411 and a release layer, and the outermost layer in the thickness direction is referred to as a surface layer. In order to make the contact angle of the surface of the pressing member 403 with respect to the silicone oil within the above-described range, it is necessary to appropriately select the material of the surface layer of the pressing member 403.

  The surface layer of the pressing member 403 preferably contains a fluoropolymer from the viewpoint of oil repellency. For example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polytetrafluoroethylene (PTFE), ethylene / tetrafluoroethylene copolymer (ETFE) , Polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), and the like. Among these, since it has a particularly low surface tension, it is preferable that the fluoropolymer contains a perfluoroalkyl group. Further, the surface layer may be formed based on a material to which a filler such as carbon fluoride, fluoride pitch, calcium fluoride or the like is added.

Specific examples of the production of the surface layer include the following. A liquid medium is added to the resin and filler as described above, and dispersed or dissolved using a known method such as an ultrasonic disperser, a stirrer, a ball mill, or a sand mill to obtain a coating solution. The coating liquid may be applied to the pressing member base material forming the surface layer by a known method such as dipping, spraying, or casting, and then dried and baked to make the surface of the pressing member. Sintering is generally performed at about 380 ° C., but if the temperature is low, the surface of the fired product tends to remain with an angular shape. If necessary, the surface may be smoothed by polishing, pressing or the like.
In addition, a method of directly fluorinating the pressing member surface, a method of indirectly fluorinating the surface with a fluorine-containing surface treatment agent, or a method of orienting fluorine-containing molecules on the surface may be used.

Moreover, it is preferable that the amount of F elements on the surface of the pressing member detected by XPS (X-ray photoelectron spectroscopy) is 50 to 75 atomic% (number of atoms%). When the amount of F element is less than 50 atomic%, the contact angle between the silicone oil and the pressing member surface layer becomes small, and toner adhesion to the surface layer of the pressing member 403 may deteriorate. Similarly, when it is larger than 75 atomic%, the toner may easily adhere to the surface layer of the pressing member 403.
The amount of F element in the surface layer is determined by an X-ray photoelectron spectrometer. In this case, the toner surface area is about several nm. As a measuring method, the surface layer of the pressing member 403 is cut out by 1 × 1 cm, adhered to a sample holder with a carbon sheet, and an X-ray photoelectron spectrometer (K-Alpha) manufactured by JEOL Ltd. is used. The X-ray source is MgKα (400 W), the analysis area is 0.8 × 2.0 mm.

  Next, the heat generating means 402 used in the fixing device 40 will be described. As shown in FIG. 2, the heat generating means 402 is fixed to an upper portion of a support member (stay) 405 via a holder 409. 2 is not limited to the position illustrated in FIG. 2 as long as the portion where the heating unit 402 contacts the member to be heated 401 is a portion excluding the nip portion formed by the pressure pad 406.

  FIG. 7 shows an embodiment of the heat generating means 402. In FIG. 7, the heater substrate 407 is provided with a heating element 408. In the figure, Y is the conveyance direction of the member to be heated 401, and X indicates the orthogonal direction. The heater substrate 407 is formed in a long shape (hereinafter also referred to as a plate shape) extending in the direction X, and is a glass in which printed wiring is applied to the substrate surface on the heated member 401 side (above the paper surface). A substrate can be used. The printed wiring pattern will be described later.

Here, the heating element 408 has a heat generation region divided into a plurality of parts in a longitudinal direction perpendicular to the conveyance direction of the recording material Pa. That is, as shown in FIG. 7, the heat generating means 402 has heat generating regions k1, k2, and k3 in regions divided in the direction X (upward and downward on the paper surface). Here, each heat generation area can control heat generation independently, and a control means 50 having a function as a heat generation control means for independently controlling heating of each heat generation area k1 to k3 in accordance with a recorded image is provided. (See FIG. 1).
Since it takes some time for the heat transferred from the heat generating means 402 to the heated member 401 to be transferred to the surface of the recording material Pa at the fixing nip n, the heat generating means 402 is preferably positioned upstream of the fixing nip n.

  The heating element 408 in the heat generating means 402 can be a single ceramic heater formed in a long plate shape, and as shown in FIG. 7, the short side of the surface of the heater substrate 407 on the heated member 401 side. It is arranged in the center (substantially center) in the direction (direction Y). The heating element 408 is formed in a long plate shape extending along the longitudinal direction of the heater substrate 407 (direction X orthogonal to the transport direction Y).

  The plate-like heater substrate 407 of the heat generating means 402 has a rectangular shape that is long in the direction X, and is integrally formed with a thin plate-like heat generating body 408 embedded in almost the entire longitudinal direction (direction X) of the surface of the heat generating body. Supported by Here, the surface of the heating element 408 is formed on a surface continuous with the surface of the heater substrate 407.

Further, the heating element 408 is divided into a plurality of heat generation areas in the axial direction (direction X) of the heated member 401 by the wiring pattern of the printed wiring (k1, k2, k3).
Here, the printed wiring for supplying power to the heating element 408 (wiring for the heating element) includes a first conduction path (connection terminal) W1 and a second conduction path W2, as shown in FIG. The first conduction path W1 is connected to both sides in the short direction (direction Y) of the heating element 408, and a plurality of first conduction paths W1 are formed at predetermined intervals in the longitudinal direction (direction X) of the heating element 408. .

  Each of the second conduction paths W2 is a predetermined number of each of the plurality of first conduction paths W1 formed with the heating element 408 interposed therebetween (four first conduction paths W1 in FIG. 7). It is connected and formed so as to extend in the longitudinal direction of the heating element 408. The second conduction path W2 adopts a wiring pattern in which three wires are distributed in the vertical direction in FIG. 7 with the longitudinal center of the heating element 408 as a boundary. FIG. 7 shows a total of 12 W2.

Then, by supplying power only to the second conduction path W2 at an arbitrary position, it is possible to generate heat only in such a region. As described above, the heating element 408 is divided into a plurality of heating regions in a direction (direction X) orthogonal to the conveyance direction Y of the heated member 401.
As shown in FIG. 7, since the heating element 408 is provided in the center of the heater substrate 407 in the direction Y, the portion of the heater substrate 407 on the heated member 401 side (above the paper surface) is the heated member. 401 can be divided into an upstream area (for example, the left side on the sheet) and a downstream area (for example, the right side on the sheet). The first conduction path W1 and the second conduction path W2 can be supported (arranged) in the upstream area and the downstream area, respectively.

  In the present embodiment, one heating element 408 is illustrated, but a plurality of heating elements may be arranged in a straight line. The heating element 408 may be a thermal head. Further, by covering the first conduction path W1, the second conduction path W2, and the heating element 408 with an overcoat layer (not shown), the surface can be formed more flat.

Next, the operation and action of the fixing device 40 according to the first embodiment will be described.
As described above, the unfixed toner image on the recording material Pa is fixed on the recording material Pa by the heat and pressure generated by the heated member 401 and the pressure member 400, but the fixing according to the present embodiment is performed. In the image forming apparatus 1 including the apparatus, the heat generating area can selectively generate heat.

In other words, the image forming apparatus including the fixing device 40 according to the present embodiment divides image data into an image area and a non-image area and fixes an unfixed toner image on the recording material Pa on the recording material Pa. Only the image area is fixed at a required fixing temperature.
Specific examples are shown in FIGS. 4 and 5 show an image area a, a non-image area b, and an image area on a recording material Pa on which an unfixed toner image of an image forming pattern including the image area is placed in order from the leading end side in the transport direction Y. An image forming pattern in which a ′ exists is shown.

As shown in FIGS. 4A and 4B, the image area a and the image area a ′ need to be fixed, but the non-image area b does not need to be fixed because there is no toner to be fixed.
Image information of the pattern is input to the control means (heat generation control means) 50 from an image processing apparatus (not shown). Then, the control means 50 controls the temperature of the member to be heated 401 by independently controlling each heat generating area (k1 to k3) according to the position information where the unfixed image is formed on the recording material Pa. Further, it functions to control the temperature of the heated member that contacts the non-image area to be lower than the temperature of the heated member that contacts the image area.

  For example, as shown in FIG. 6, the temperature of the heated member 401 corresponding to the non-image area b is lower than the temperature of the heated member 401 corresponding to the image areas a and a ′. To control.

Here, the part corresponding to the image region or the non-image region means a position where the heated member 401 is in close contact with the image / non-image region.
That is, the power corresponding to the fixing temperature is supplied to the entire area of the heat generating unit 402 in the part corresponding to the image area a, and the supplied power is reduced in the part corresponding to the non-image area b. In the portion corresponding to the paper rear end image area a ′, the electric power for obtaining the fixing temperature is supplied again.
At this time, the actual supplied power is input so as to preliminarily heat the portion before the image area enters the nip portion as indicated by the hatched portion in the figure. This preheating region s1 is a region that is mainly required because the heat generation length in the circumferential direction of the heat generating means 402 and the heating element itself also require a temperature rise time (warm up time). The preheating region s1 is desirably as small as possible from the viewpoint of energy saving.

5A and 5B show an image forming pattern in which an image region c and a non-image region d exist on a recording material Pa in a direction X orthogonal to the transport direction Y. FIG.
In particular, in FIG. 5B, an image region g (a region overlapping regions e and f) exists in a direction X orthogonal to the transport direction Y on the leading end side in the transport direction Y of the recording material Pa. In addition to this, on the rear end side in the transport direction Y, image formation in which an image region (a region where regions e and h overlap) and a non-image region (a region where regions f and h overlap) exist in a direction X orthogonal to the transport direction Y. It shows a pattern.

Similarly in these cases, the temperature of the heated member 401 in the part corresponding to the non-image area d and the non-image area (f-h) is higher than the temperature of the heated member part corresponding to the image areas c and e. Also, the heating means 402 is controlled so as to be low.
That is, the power corresponding to the fixing temperature is supplied to the heat generating means 402 at the portion corresponding to the image region c, and the supplied power is reduced at the portion corresponding to the non-image region d. This also requires the preheating region s1 in the shaded portion as described above.

  In this case, as temperature control of the heated member 401 performed by the control unit 50, the power supply may be completely stopped (turned off) at a portion corresponding to the non-image areas b and d. However, if the temperature is excessively lowered, the rise to the fixing temperature in the next image area may not be in time. For this reason, as shown in FIG. 6, the fixing belt temperature (heated member temperature) is maintained at a second target temperature that is lower than the first target temperature corresponding to the image region but is equal to or higher than the room temperature. It is desirable to control.

As described above, the heat generation area divided into a plurality of portions is a non-image portion where the toner image is not transferred by heating the image portion to which the toner image has been transferred to the fixing temperature according to the position of the toner image on the recording material Pa. Can be controlled to be lower than the fixing temperature.
As a result, power is supplied even at the portion corresponding to the non-image area b, but the power supply is reduced. That is, since the power supplied in the region P ′ is smaller than the power supplied in the region P in FIG. 6, energy saving can be achieved.

<Second Embodiment>
Next, another embodiment of the fixing device according to the present invention will be described. In addition, the description about the same point as the said embodiment is abbreviate | omitted.
A schematic side view of the fixing device 40A according to the present embodiment is shown in FIG. The fixing device 40A includes a pressure member 400, a heated member 401A, a support roller 415, a fixing roller 416, a heating unit 402A, and a pressing roller 403A.

The fixing device 40A according to the second embodiment is different from the fixing device 40 according to the first embodiment in that the heated member 401A is formed of an endless belt, and the heating means 402A is provided on the side of the heated member 401A. It differs in that it is deployed.
Here, the heated member 401A of the endless belt is wound around the support roller 415 located on the upper side of the fixing device 40A and the fixing roller 416 located on the lower side, so that the fixing roller 416 sandwiches the heated member 401A. A pressure nip (pressure roller) 400 is in pressure contact to form a fixing nip n.

  The heating means 402A is disposed on the inner side of the heated member 401A of the endless belt, and a pressing member (pressing roller) 403A is disposed on the opposite outer side. The member to be heated 401A is pressed against the heating means 402A by the pressing member 403A to facilitate heating.

  Such a fixing device 40A as the second embodiment can obtain the same effects as the fixing device 40 of the first embodiment, and in particular, can easily obtain the heating performance and the degree of freedom of the outer shape of the heating means 402A. it can.

(toner)
Next, the toner used in the fixing device and the image forming apparatus according to the present invention will be described.
<Volume average particle diameter>
The volume average particle size of the toner in the present invention is preferably 3 to 9 μm. If the volume average particle size is less than 3 μm, the adhesion to the photoconductor may increase, and the primary transferability may be insufficient. Conversely, if it is greater than 9 μm, the scattering of characters and lines should be suppressed. May be difficult.

The volume average particle size of the toner can be measured using a Coulter Multisizer. Specific examples are shown below.
A Coulter Multisizer III (manufactured by Coulter Inc.) is used as the measuring device, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting the number distribution and volume distribution is connected to a personal computer. To prepare a 1% by weight aqueous NaCl solution. As a measurement method, 0.1 to 5 mL of a surfactant (alkylbenzene sulfonate) is added as a dispersant to 100 to 150 mL of the aqueous solution as the electrolytic solution, and 2 to 20 mg of a measurement sample is further added. A dispersion process of about 1 to 3 minutes is performed. Further, 100 to 200 mL of an electrolytic aqueous solution was put into another beaker, and the sample dispersion was added to a predetermined concentration therein, and 50,000 particles were used by the Coulter Multisizer III using a 100 μm aperture as an aperture. This can be done by measuring the average of.

<Binder resin>
The binder resin is not particularly limited, and a commonly used resin can be appropriately selected and used. For example, vinyl such as styrene monomer, acrylic monomer, methacrylic monomer, etc. Polymers, copolymers of these monomers or two or more types, polyester polymers, polyol resins, phenol resins, silicone resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, terpene resins, Coumarone indene resin, polycarbonate resin, petroleum resin and the like can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferable to use a polyester-based polymer because the affinity between the ester group of the polyester and the hydroxyl group of cellulose in the paper is high and the fixing property is good.

  Examples of the styrene monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-amyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, Examples thereof include styrene such as p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, and p-nitrostyrene, or derivatives thereof.

  Examples of acrylic monomers include acrylic acid, or methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, n-dodecyl acrylate, and acrylic acid. Examples include 2-ethylhexyl, stearyl acrylate, 2-chloroethyl acrylate, acrylic acid such as phenyl acrylate, or esters thereof.

  Examples of the methacrylic monomer include methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, and methacrylic acid 2 -Ethylhexyl, stearyl methacrylate, phenyl methacrylate, methacrylic acid such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate or esters thereof, and the like.

  The following (1)-(18) is mentioned as an example of the other monomer which forms the said vinyl polymer or a copolymer. (1) Monoolefins such as ethylene, propylene, butylene and isobutylene; (2) Polyenes such as butadiene and isoprene; (3) Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; (4) Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; (5) Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; (6) Vinyl methyl ketone, vinyl hexyl ketone and methyl. Vinyl ketones such as isopropenyl ketone; (7) N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone; (8), vinyl naphthalenes; (9) acrylonitrile, Such as methacrylonitrile, acrylamide, etc. (10) unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; (11) maleic anhydride, citraconic anhydride, Unsaturated dibasic acid anhydrides such as itaconic anhydride and alkenyl succinic anhydride; (12) maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid monobutyl ester, citraconic acid monomethyl ester, citraconic acid monoethyl ester Monoesters of unsaturated dibasic acids such as citraconic acid monobutyl ester, itaconic acid monomethyl ester, alkenyl succinic acid monomethyl ester, fumaric acid monomethyl ester, mesaconic acid monomethyl ester; (13) dimethylmaleic acid, dimethylfumaric acid, etc. (14) α, β-unsaturated acids such as crotonic acid and cinnamic acid; (15) α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic anhydride; 16) Monomers having a carboxyl group such as anhydrides of the α, β-unsaturated acids and lower fatty acids, alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof; ) Acrylic acid or methacrylic acid hydroxyalkyl esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; (18) 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1 -Hydroxy-1-methylhexyl) monomers having a hydroxy group such as styrene.

In the toner of the present invention, the vinyl polymer or copolymer of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups.
Examples of the crosslinking agent used in this case include aromatic vinyl vinyl compounds such as divinylbenzene and divinylnaphthalene.
Examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, and 1,6. And xanthdiol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylates of these compounds with methacrylate.
Examples of diacrylate compounds linked by an alkyl chain containing an ether bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, and dipropylene. Examples include glycol diacrylate and those obtained by replacing acrylate of these compounds with methacrylate.

  Other examples include diacrylate compounds and dimethacrylate compounds linked by a chain containing an aromatic group and an ether bond. Examples of polyester diacrylates include trade name MANDA (manufactured by Nippon Kayaku Co., Ltd.).

  Examples of the polyfunctional crosslinking agent include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds in place of methacrylate, triallyl cyanide. Examples thereof include nurate and triallyl trimellitate.

  These crosslinking agents are preferably used in an amount of 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, with respect to 100 parts by mass of other monomer components. Among these crosslinkable monomers, diacrylates bonded to a toner resin by a bond chain containing one aromatic divinyl compound (especially divinylbenzene), one aromatic group and an ether bond from the viewpoint of fixability and offset resistance. Preferred examples include compounds. Among these, a combination of monomers that becomes a styrene copolymer or a styrene-acrylic copolymer is preferable.

  Examples of the polymerization initiator used for the production of the vinyl polymer or copolymer include 2,2′-azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile). ), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), dimethyl-2,2′-azobisisobutyrate, 1,1 ′ -Azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2'-azobis (2,4,4-trimethylpentane), 2-phenylazo-2 ', 4' -Dimethyl-4'-methoxyvaleronitrile, 2,2'-azobis (2-methylpropane), methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohex Ketone peroxides such as non-peroxides, 2,2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide , Di-tert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, α- (tert-butylperoxy) isopropylbenzene, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide Oxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-tolyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propiate Peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-ethoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, tert-butyl Peroxyacetate, tert-butylperoxyisobutyrate, tert-butylperoxy-2-ethylhexarate, tert-butylperoxylaurate, tert-butyl-oxybenzoate, tert-butylperoxyisopropylcarbonate, di- tert-butylperoxyisophthalate, tert-butylperoxyallyl carbonate, isoamylperoxy-2-ethylhexanoate, di-tert-butylperoxyhexahydroterephthalate, tert-butylperoxyase Over door, and the like.

  The acid value when the binder resin is a vinyl polymer such as styrene-acrylic resin is preferably 0.1 mgKOH / g to 100 mgKOH / g, and preferably 0.1 mgKOH / g to 70 mgKOH / g. More preferably, it is 0.1 mgKOH / g-50 mgKOH / g.

The following are mentioned as a monomer which comprises a polyester-type polymer.
Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, or diol obtained by polymerizing cyclic ethers such as ethylene oxide and propylene oxide to bisphenol A, etc. Is mentioned. In order to crosslink the polyester resin, it is preferable to use a trivalent or higher alcohol together.

  Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, such as dipentaerythritol, tripentaerythritol, 1,2,4- Butanetriol, 1,2,5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene , Etc.

  Examples of the acid component that forms the polyester polymer include benzene dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid or anhydrides thereof, alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or Unsaturated dibasic acids such as anhydride, maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride And the like, and the like. Examples of the trivalent or higher polyvalent carboxylic acid component include trimet acid, pyromet acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra (methylene Carboxy) methane, 1,2,7,8-octanetetracarboxylic acid, empol trimer acid, or anhydrides thereof, partial lower alkyl esters, and the like.

  When the binder resin is a polyester resin, the acid value is preferably 0.1 mgKOH / g to 100 mgKOH / g, more preferably 0.1 mgKOH / g to 70 mgKOH / g, and 0.1 mgKOH / g. Most preferably, it is g-50 mgKOH / g.

  As the binder resin that can be used in the toner of the present invention, a resin containing a monomer component capable of reacting with both of these resin components in at least one of the vinyl polymer component and the polyester resin component can also be used. . Examples of monomers that can react with the vinyl polymer among the monomers constituting the polyester resin component include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Examples of the monomer constituting the vinyl polymer component include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  Moreover, when using together a polyester polymer, a vinyl polymer, and another binder resin, what has 60 mass% or more of resin whose acid value of the whole binder resin has 0.1-50 mgKOH / g is preferable.

In the present invention, the acid value of the binder resin component of the toner composition is determined by the following method, and the basic operation conforms to JIS K-0070.
(1) The sample is used by removing additives other than the binder resin (polymer component) in advance, or the acid value and content of components other than the binder resin and the crosslinked binder resin are obtained in advance. . The sample pulverized product 0.5 to 2.0 g is precisely weighed, and the weight of the polymer component is defined as Wg. For example, when measuring the acid value of the binder resin from the toner, the acid value and content of the colorant or magnetic material are separately measured, and the acid value of the binder resin is obtained by calculation.
(2) A sample is put into a 300 (ml) beaker, and a mixed solution 150 (ml) of toluene / ethanol (volume ratio 4/1) is added and dissolved.
(3) Titrate with a potentiometric titrator using an ethanol solution of 0.1 mol / l KOH.
(4) The amount of use of the KOH solution at this time is S (ml), a blank is measured at the same time, the amount of use of the KOH solution at this time is B (ml), and the following formula is used. However, f is a factor of KOH.
Acid value (mgKOH / g) = [(SB) × f × 5.61] / W

-Modified polyester (prepolymer) capable of reacting with active hydrogen group-containing compound-
Furthermore, the binder resin in the present invention may contain a modified polyester capable of reacting with an active hydrogen group-containing compound (hereinafter sometimes referred to as a polyester prepolymer). The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when the polyester capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction, a crosslinking reaction, or the like in the toner production process. When the polyester prepolymer is subjected to an extension reaction to increase the molecular weight, the heat resistant storage stability of the toner and the stickiness of the image after fixing can be effectively reduced.
The polyester prepolymer in this case is not particularly limited as long as it can react with the active hydrogen group-containing compound, but examples thereof include modified polyesters having an isocyanate group, an epoxy group, a carboxylic acid, an acid chloride group, and the like. Particularly preferred are modified polyesters containing isocyanate groups.

  The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. For example, when the modified polyester capable of reacting with the active hydrogen group-containing compound is an isocyanate group-containing modified polyester, the isocyanate group-containing modified polyester can be increased in molecular weight by a reaction such as an extension reaction or a crosslinking reaction. Amines are preferred.

  The amines are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, 4,4′-diamino-3,3′dimethyl. Examples include dicyclohexylmethane, diaminecyclohexane, isophoronediamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, ethanolamine, hydroxyethylaniline, aminoethyl mercaptan, aminopropyl mercaptan, aminopropionic acid, and aminocaproic acid. . In addition, ketimine compounds, oxazolidone compounds, and the like in which these amino groups are blocked with ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) may be mentioned.

<Surfactant>
In the preparation of the toner, a surfactant may be used for the purpose of emulsifying / dispersing the constituent components. There is no restriction | limiting in particular as surfactant, Anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, etc. are mentioned. One surfactant may be used alone, or two or more surfactants may be used in combination.

As the anionic surfactant, carboxylic acid or a salt thereof, a sulfate ester salt, a salt of a carboxymethylated product, a sulfonate salt, a phosphate ester salt, or the like is used.
As the cationic surfactant, a quaternary ammonium salt type surfactant, an amine salt type surfactant and the like can be used.
As the amphoteric surfactant, a carboxylate type amphoteric surfactant, a sulfate ester type amphoteric surfactant, a sulfonate type amphoteric surfactant, a phosphate ester type amphoteric surfactant and the like can be used.
As the nonionic surfactant, an AO addition type nonionic surfactant and a polyhydric alcohol type nonionic surfactant can be used.

<Release agent>
The toner in the present invention preferably contains a release agent. When the release agent is not contained, toner adhesion to the pressing member 403 may be deteriorated. Although the detailed cause is unknown, the wax (release agent) exuded from the toner melted at the nip portion moves from the heated member 401 to the pressing member 403 and adheres to the pressing member 403 in a small amount. This is considered to be because the toner is less likely to adhere to the pressing member 403.
There is no restriction | limiting in particular in the kind of mold release agent, According to the objective, it can select suitably, For example, waxes, waxes, etc. are mentioned suitably.
Examples of the waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax and sunflower wax; animal waxes such as beeswax and lanolin; minerals such as ozokerite and cercin Natural waxes such as waxes; petroleum waxes such as paraffin, microcrystalline, and petrolatum; In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax; synthetic waxes such as esters, ketones and ethers; Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons; poly-n-stearyl methacrylate, poly-n-lauryl which are low molecular weight crystalline polymer resins A homopolymer or copolymer of polyacrylate such as methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.); a crystalline polymer having a long alkyl group in the side chain, or the like may be used. These may be used alone or in combination of two or more.

The content of the release agent in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 30% by mass, and more preferably 2 to 20% by mass. When the content exceeds 20% by mass, the fluidity of the toner may be deteriorated.
The surface mold release agent exposure amount of the toner is preferably 9 to 13 mg / g with respect to 1 g of the toner. When the surface release agent exposure amount is less than 9 mg / g or more than 13 mg / g, the adhesion of toner to the pressing member tends to deteriorate. A very small amount of wax (WAX) needs to be adhered to the pressing member. However, if too much adheres, the toner tends to adhere and accumulate on the contrary, with the adhered wax as a core. The surface release agent exposure amount indicates the amount of the release agent exposed on the toner surface.

  The toner surface release agent exposure amount can be determined by a hexane extraction method. 1.0 g of the toner base particles before adding the external additive is weighed, 7 mL of n-hexane is added, and the mixture is stirred with a roll mill at 120 rpm for 1 minute. The solution is suction filtered, and n-hexane is removed by a vacuum dryer. The mass (mg) of the component that has been removed and remained can be determined as the surface release agent exposure amount.

<Other ingredients>
In the toner of the present invention, in addition to the binder resin and the release agent, other components such as a charge control agent, a colorant, a deforming agent, inorganic fine particles, a fluidity improver, a cleaning property improver, and a magnetic material are included. You may make it contain as needed.

-Charge control agent-
The toner in the present invention may contain a charge control agent in the toner for the purpose of controlling the chargeability of the toner. The charge control agent is not particularly limited and includes the following materials.

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

  The content of the charge control agent is preferably 0.01 parts by mass to 2 parts by mass, and 0.02 parts by mass to 1 part by mass with respect to 100 parts by mass of the binder resin (resin content in the resin particles). More preferred. When the content is 0.01 parts by mass or more, charge controllability is obtained. When the content is 2 parts by mass or less, the chargeability of the toner is not excessively increased, and the effect of the main charge control agent is reduced. In addition, the electrostatic attraction force with the developing roller is not increased, and the fluidity of the toner and the image density are not lowered.

-Colorant-
In the present invention, the colorant is not particularly limited and can be appropriately selected from known colorants according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL , Isoindolinone yellow, bengara, red lead, red lead, cadmium red, cadmium mercury red, antimony red, permanent red 4R, para red, phise red, parachlor ortho nitroaniline red, risor fast scarlet G, Reliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine Range, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo , Ultramarine, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridiane, emerald green, pigment green B, naphthol green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Oxidized Chi Tan, zinc white, litbon, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The color of the toner colorant is not particularly limited and may be appropriately selected according to the purpose, and may be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. The toner can be obtained by appropriately selecting the type of colorant, but is preferably a color toner.

  Examples of black materials include carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), titanium oxide, and the like. And organic pigments such as aniline black (CI Pigment Black 1).

  Examples of the magenta color pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 1, 49, 50, 51, 52, 53, 53: 1, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 177, 179, 202, 206, 207, 209, 211; C.I. I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, and the like.

  Examples of the color pigment for cyan include C.I. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 60; I. Bat Blue 6; C.I. I. Acid Blue 45 and copper phthalocyanine pigments having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton, Green 7, Green 36, and the like.

  Examples of the color pigment for yellow include C.I. I. Pigment Yellow 0-16, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97, 110, 151, 154, 180; C.I. I. Bat yellow 1, 3, 20, orange 36, and the like.

  The content of the colorant in the toner is preferably 1% by mass to 15% by mass and more preferably 3% by mass to 10% by mass with respect to the toner mass. When the content is less than 1% by mass, the coloring power of the toner may be reduced. When the content is more than 15% by mass, poor dispersion of the pigment in the toner occurs, and the coloring power decreases and the electrical characteristics of the toner. May be reduced.

  The colorant may be used as a master batch combined with a resin. There is no restriction | limiting in particular as such resin, According to the objective, it can select suitably from well-known things. For example, polyester, styrene or its substituted polymer, styrene copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, epoxy resin, epoxy polyol resin, polyurethane, Examples thereof include polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, and paraffin wax. These may be used individually by 1 type and may use 2 or more types together.

  The master batch can be produced by applying a high shear force and mixing or kneading the resin and the colorant. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. The flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove water and the organic solvent. For mixing or kneading, for example, a high shear dispersion device such as a three-roll mill can be used.

  As the usage-amount of the said masterbatch, 0.1-20 mass parts is preferable with respect to 100 mass parts of binder resin.

  The resin for the masterbatch preferably has an acid value of 30 mgKOH / g or less, an amine value of 1 to 100, and a colorant dispersed therein. The acid value is 20 mgKOH / g or less and the amine value is 10 It is more preferable that the colorant is dispersed and used at ˜50. When the acid value exceeds 30 mgKOH / g, the chargeability under high humidity may be lowered, and the pigment dispersibility may be insufficient. Also, when the amine value is less than 1 and when the amine value exceeds 100, the pigment dispersibility may be insufficient. The acid value can be measured by the method described in JIS K0070, and the amine value can be measured by the method described in JIS K7237.

  The dispersant is preferably highly compatible with the binder resin in terms of pigment dispersibility, and specific commercially available products include Ajisper PB821, Ajisper PB822 (manufactured by Ajinomoto Fine Techno Co., Ltd.), Disperbyk-2001. (Manufactured by Big Chemie), EFKA-4010 (manufactured by EFKA), and the like.

  The dispersant is preferably blended in the toner at a ratio of 0.1 to 10% by mass with respect to the colorant. When the blending ratio is less than 0.1% by mass, the pigment dispersibility may be insufficient, and when it is more than 10% by mass, the chargeability under high humidity may be deteriorated.

  The mass average molecular weight of the dispersant is a molecular weight of the maximum value of the main peak in terms of styrene in gel permeation chromatography (GPC), preferably 500 to 100,000, and from the viewpoint of pigment dispersibility, 3000 to 100,000. More preferred. In particular, 5000 to 50000 is preferable, and 5000 to 30000 is more preferable. When the molecular weight is less than 500, the polarity becomes high and the dispersibility of the colorant may be lowered. When the molecular weight exceeds 100,000, the affinity with the solvent is increased and the dispersibility of the colorant is lowered. There is.

  The addition amount of the dispersant is preferably 1 to 200 parts by mass, more preferably 5 to 80 parts by mass with respect to 100 parts by mass of the colorant. If it is less than 1 part by mass, the dispersibility may be lowered, and if it exceeds 200 parts by mass, the chargeability may be lowered.

-Profiler-
The deforming agent is contained for the purpose of deforming the shape of the color toner. Although it can select suitably as a deforming agent, it is preferable to contain the layered inorganic mineral which modified | denatured at least one part of the ion which the layered inorganic mineral has with the organic substance ion. As such a layered inorganic mineral, one having a smectite basic crystal structure modified with an organic cation is desirable. Moreover, a metal anion can be introduce | transduced by substituting a part of bivalent metal of a layered inorganic mineral for a trivalent metal. However, since the hydrophilicity is increased when a metal anion is introduced, a layered inorganic compound in which at least a part of the metal anion is modified with an organic anion is desirable.

There is no restriction | limiting in particular as said organic cation modifier | denaturant, A quaternary alkyl ammonium salt, a phosphonium salt, an imidazolium salt etc. are mentioned. Among them, a quaternary alkyl ammonium salt is desirable, and examples thereof include trimethyl stearyl ammonium, dimethyl stearyl benzyl ammonium, and oleyl bis (2-hydroxyethyl) methyl ammonium.
There is no restriction | limiting in particular as said organic substance anion modifier, Branched, unbranched or cyclic alkyl (C1-C44), alkenyl (C1-C22), alkoxy (C8-32), hydroxyalkyl (carbon) 2-22), sulfates, sulfonates, carboxylates, or phosphates having ethylene oxide, propylene oxide, and the like. Of these, carboxylic acids having an ethylene oxide skeleton are desirable.

When at least a part of the layered inorganic mineral is modified with organic ions, it becomes moderately hydrophobic, so that the oil phase containing the toner composition has a non-Nutnian viscosity and deforms the toner. Can do.
The layered inorganic mineral can be appropriately selected, and examples thereof include montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and a mixture thereof. Among them, montmorillonite or bentonite is preferable because the viscosity can be easily adjusted without affecting the toner characteristics and the addition amount can be made small.
The content of the layered inorganic mineral partially modified with organic ions is preferably 0.05 to 10% by mass, more preferably 0.05 to 5% by mass in the toner material.

  Commercially available products of layered inorganic minerals partially modified with an organic cation include Bentone 3, Bentone 38, Bentone 38V (above, manufactured by Leox), Thixogel VP (manufactured by United catalyst), Kraton 34, Kraton 40, Kraton XL Quartium 18 bentonite such as (made by Southern Clay), and stearalkonium bentonite such as Bentone 27 (made by Leox), Thixogel LG (made by United catalyst), Clayton AF, Clayton APA (made by Southern Clay) Quaternium 18 / benzalkonium bentonite such as Clayton HT and Clayton PS (manufactured by Southern Clay). Among these, Clayton AF and Clayton APA are preferable.

Moreover, as the layered inorganic mineral in which the part is modified with an organic anion, a material obtained by modifying DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) with an organic anion represented by the following general formula is preferable. As the commercial item, for example, Hytenol 330T (Daiichi Kogyo Seiyaku Co., Ltd.) can be mentioned.
“R1 (OR2) _n OSO ₃ M”
(In the above formula, R1 represents an alkyl group having 13 carbon atoms, R2 represents an alkylene group having 2 to 6 carbon atoms, M represents a monovalent metal element, and n represents an integer of 2 to 10).

-Inorganic fine particles-
The toner in the present invention may have inorganic fine particles as an external additive for imparting fluidity, developability, chargeability and the like to the toner particles.

There is no restriction | limiting in particular as inorganic fine particles, According to the objective, it can select suitably from well-known things. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide , Bengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and the like.
These may be used individually by 1 type and may use 2 or more types together. The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and more preferably 5 nm to 500 nm.
The content of the inorganic fine particles in the toner is preferably 0.01% by mass to 5.0% by mass, and more preferably 0.01% by mass to 2.0% by mass. Within this range, the fluidity, developability, and chargeability of the toner are improved.

-Fluidity improver-
The fluidity improver means a material that can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, a fluoride. Silane coupling agents having an alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, and the like. Among these, silica and titanium oxide are preferably subjected to surface treatment with such a fluidity improver and used as hydrophobic silica or hydrophobic titanium oxide.

-Cleaning improver-
The cleaning property improver is added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium. For example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, polymethyl methacrylate, etc. Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 μm to 1 μm are suitable.

-Magnetic material-
There is no restriction | limiting in particular as a magnetic material, According to the objective, it can select suitably from well-known things, For example, iron powder, a magnetite, a ferrite, etc. are mentioned. Among these, white is preferable in terms of color tone.

<Method for producing core particles>
The method for producing the core particles constituting the toner is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a pulverization method, a monomer composition containing a specific polymerizable monomer is used. Polymerization method that directly polymerizes in the aqueous phase (suspension polymerization method, emulsion polymerization method), a method of emulsifying or dispersing a specific binder resin solution in an aqueous medium, dissolving in a solvent, removing the solvent, and pulverizing Method, melt spraying method and the like.

-Grinding method-
The pulverization method is, for example, a method of obtaining the toner base particles by melting or kneading the toner material, pulverizing, classifying or the like. In the case of the pulverization method, for the purpose of increasing the average circularity of the toner, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

  The toner materials described above are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial continuous kneader, a biaxial continuous kneader, or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel Co., Ltd., TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay Co., Ltd., PCM type twin screw extruder manufactured by Ikegai Iron Works, Inc. A manufactured kneader or the like is preferably used. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt kneading temperature is performed with reference to the softening point of the binder resin. If the temperature is higher than the softening point, cutting is severe, and if the temperature is too low, dispersion may not proceed.

In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. In this case, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing in a narrow gap between a mechanically rotating rotor and a stator is preferably used. .
In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed, for example, by removing the fine particle portion by a cyclone, a decanter, centrifugation, or the like.
After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like to produce a toner having a predetermined particle size.

-Suspension polymerization method-
The suspension polymerization method will be described later in an aqueous medium in which a colorant, a release agent, and the like are dispersed in an oil-soluble polymerization initiator, a polymerizable monomer, and a surfactant and other solid dispersants are contained. Emulsified and dispersed by an emulsification method. Thereafter, a polymerization reaction is performed to form particles, and then wet processing for attaching inorganic fine particles to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.

Examples of the polymerizable monomer include acrylic acids, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids, acrylamide, By using a part of acrylate or methacrylate having amino group such as methacrylamide, diacetone acrylamide or their methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate, etc. Functional groups can be introduced.
Further, by selecting a dispersant having an acid group or a basic group as the dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

-Emulsion polymerization method-
As the emulsion polymerization method, a water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by a usual emulsion polymerization method. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, wet processing of inorganic fine particles described later may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer used in the suspension polymerization method.

-Method of emulsifying or dispersing a specific binder resin solution in an aqueous medium-
As a method of emulsifying or dispersing a specific binder resin solution in the aqueous medium, a solution or dispersion of a toner material having at least a binder resin is emulsified or dispersed in an aqueous medium, and the emulsion or dispersion is obtained. After the toner is prepared, the toner is granulated (aqueous granulation). This method includes, for example, the following steps [1] to [4].

Step [1]: Preparation of Solution or Dispersion of Toner Material The toner material solution or dispersion is prepared by dissolving or dispersing a toner material such as a colorant or a binder resin in an organic solvent. The organic solvent is removed during or after the toner granulation.

Step [2]: Preparation of aqueous medium The aqueous medium is not particularly limited and may be appropriately selected from known ones such as water, alcohol miscible with water, dimethylformamide, tetrahydrofuran, and cellosolve. And solvents such as lower ketones, and mixtures thereof. Among these, water is particularly preferable.
The aqueous medium can be prepared, for example, by dispersing a dispersion stabilizer such as resin fine particles in the aqueous medium. The amount of resin fine particles added to the aqueous medium is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 0.5 to 10% by mass is preferable.

The resin fine particle is not particularly limited as long as it is a resin that can form an aqueous dispersion in an aqueous medium, and can be appropriately selected from known resins according to the purpose, and may be a thermoplastic resin. It may be a thermosetting resin, for example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin. , Etc.
These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferably formed of at least one selected from a vinyl resin, a polyurethane resin, an epoxy resin, and a polyester resin in that an aqueous dispersion of fine spherical resin particles can be easily obtained.

  In addition, in the aqueous medium, if necessary, from the viewpoint of stabilizing the oil droplets of the solution or dispersion at the time of emulsification or dispersion described later, and sharpening the particle size distribution while obtaining a desired shape, It is preferable to use a dispersant. There is no restriction | limiting in particular as a dispersing agent, According to the objective, it can select suitably, For example, surfactant, a poorly water-soluble inorganic compound dispersing agent, a polymeric protective colloid, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, surfactants are preferable.

Step [3]: Emulsification or dispersion When the solution or dispersion containing the toner material is emulsified or dispersed in the aqueous medium, the solution or dispersion containing the toner material is dispersed in the aqueous medium while stirring. Is preferred. The dispersion method is not particularly limited, but a batch type emulsifier such as a homogenizer (manufactured by IKA), polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Ebara Mile Dar (manufactured by Aihara Seisakusho Co., Ltd.), TK Fillmix, TK Pipeline Homomixer (manufactured by Koki Kogyo Kogyo Co., Ltd.), Colloid Mill (manufactured by Shinko Pantech Co., Ltd.), Thrasher, Trigonal Wet Fine Crusher (Mitsui Miike Chemical Co., Ltd.) ), Captron (manufactured by Eurotech), continuous emulsifier such as fine flow mill (manufactured by Taiheiyo Kiko), microfluidizer (manufactured by Mizuho Kogyo), nanomizer (manufactured by Nanomizer), APV Gaurin (manufactured by Gaurin) High-pressure emulsifiers such as membrane emulsifiers such as membrane emulsifiers (manufactured by Chilling Industries Co., Ltd.) Reduction machine, an ultrasonic emulsifier such as an ultrasonic homogenizer (manufactured by Branson Co., Ltd.). Among these, it is preferable to use APV Gaurin, homogenizer, TK auto homomixer, Ebara milder, TK fill mix, and TK pipeline homomixer from the viewpoint of uniform particle size.

  In the case where a modified polyester (prepolymer) capable of reacting with an active hydrogen group-containing compound is included as the binder resin contained in the solution or dispersion, the reaction proceeds during emulsification or dispersion. The reaction conditions are not particularly limited and can be appropriately selected according to the combination of the polymer capable of reacting with the active hydrogen group-containing compound and the active hydrogen group-containing compound. The reaction time is 10 minutes to 40 hours is preferable, and 2 hours to 24 hours is more preferable.

Step [4]: Removal of Solvent Next, the organic solvent is removed from the emulsified slurry obtained by the emulsification or dispersion. The organic solvent is removed by (1) a method in which the temperature of the entire reaction system is gradually raised to completely evaporate and remove the organic solvent in the oil droplets, and (2) the emulsion dispersion is sprayed in a dry atmosphere, Examples thereof include a method in which the water-insoluble organic solvent in the droplets is completely removed to form toner fine particles, and the aqueous dispersant is removed by evaporation.

(Developer)
The developer in the present invention contains the above-described toner and other components appropriately selected such as a carrier. The developer in the present invention may be a one-component developer or a two-component developer. However, when used in a high-speed printer or the like corresponding to the recent improvement in information processing speed, the life is improved. In this respect, a two-component developer is preferable.
The carrier content in the two-component developer is not particularly limited and may be appropriately selected depending on the intended purpose. The preferable mixing ratio of the toner and the carrier is 1 to 10 parts of the toner with respect to 100 parts of the carrier.

<Career>
There is no restriction | limiting in particular as a carrier, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.
There is no restriction | limiting in particular as a material of a core material, It can select suitably from well-known things. For example, 50-90 emu / g manganese-strontium (Mn-Sr) -based material, manganese-magnesium (Mn-Mg) -based material and the like are preferable, and in terms of securing image density, iron powder (100 emu / g or more), A highly magnetized material such as magnetite (75 to 120 emu / g) is preferred. In addition, the copper-zinc (Cu-Zn) system (30 to 80 emu) is advantageous in that it can weaken the contact with the electrostatic latent image carrier (photosensitive member) in which the toner is in a spiked state, and is advantageous in improving the image quality. / G) and the like are preferred. These may be used alone or in combination of two or more.

  The particle diameter of the core material is preferably 10 to 200 μm and more preferably 40 to 100 μm in terms of mass average particle diameter (D50). When D50 is less than 10 μm, the number of fine powder systems increases in the distribution of carrier particles, and the magnetization per particle may be lowered to cause carrier scattering. On the other hand, if it exceeds 200 μm, the specific surface area may decrease and toner scattering may occur, and in the case of full color with many solid portions, reproduction of the solid portions may be particularly poor.

  There is no restriction | limiting in particular as a material of the resin layer which coat | covers a core material, According to the objective, it can select suitably from well-known resin. For example, amino resin, polyvinyl resin, polystyrene resin, halogenated olefin resin, polyester resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene Fluoropolymers such as resins, copolymers of vinylidene fluoride and acrylic monomers, copolymers of vinylidene fluoride and vinyl fluoride, terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers Examples include terpolymer [fluorinated triple (multiple) copolymer], silicone resin, and the like. These may be used alone or in combination of two or more. Among these, a silicone resin is preferable in that the effect of preventing toner filming on the carrier is high.

There is no restriction | limiting in particular as silicone resin which comprises a resin layer, According to the objective, it can select suitably from generally known silicone resins. For example, a straight silicone resin composed only of an organosiloxane bond; a silicone resin modified with an alkyd resin, a polyester resin, an epoxy resin, an acrylic resin, a urethane resin, or the like can be given.
Examples of commercially available silicone resins include KR271, KR255, and KR152 manufactured by Shin-Etsu Chemical Co., Ltd .; SR2400, SR2406, and SR2410 manufactured by Toray Dow Corning Silicone.
Commercially available modified silicone resins include KR206 (alkyd modified), KR5208 (acrylic modified), ES1001N (epoxy modified), KR305 (urethane modified) manufactured by Shin-Etsu Chemical Co., Ltd .; SR2115 manufactured by Toray Dow Corning Silicone Co., Ltd. Epoxy modified), SR2110 (alkyd modified), and the like.
In addition, although a silicone resin can be used alone, it is also possible to simultaneously use a component that undergoes a crosslinking reaction, a charge amount adjusting component, and the like.

The resin layer covering the core material may contain conductive powder or the like as necessary, and examples thereof include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The volume average particle diameter of these conductive powders is preferably 1 μm or less. When the volume average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.
The resin layer covering the core material is prepared by, for example, dissolving a silicone resin or the like in an organic solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, followed by drying. It can be formed by baking. Examples of the application method include an immersion method, a spray method, and a brush coating method.

There is no restriction | limiting in particular as said organic solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cellosolve, butyl acetate etc. are mentioned.
The resin layer baking means is not particularly limited, and may be an external heating method or an internal heating method. For example, a method using a fixed electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, or a microwave Method, etc.
The amount of the resin layer in the carrier is preferably 0.01 to 5.0% by mass. If it is less than 0.01% by mass, a uniform resin layer may not be formed on the surface of the core material. If it exceeds 5.0% by mass, the resin layer becomes too thick and granulates between carriers. May occur, and uniform carrier particles may not be obtained.

Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples, and these examples are appropriately modified without departing from the gist of the present invention. Is also within the scope of the present invention.

(Production of pressure roller)
An iron core with an outer diameter of φ8mm is placed in the mold, unvulcanized liquid foamed silicone rubber is injected into the mold cavity, and pressurized and vulcanized at the same time to cure and cure. did. Thereafter, the foamed silicone rubber layer (elastic layer) formed by vulcanization was cut into a cylindrical shape.
After mixing 100 parts of the surface layer material shown in Table 1 below and 100 parts of distilled water, the mixture was dispersed for 20 minutes with an ultrasonic disperser to obtain a surface layer coating material. Using this coating material, the release layer was formed by spray coating onto the foamed silicone rubber layer with the aim of setting the thickness of the release layer after firing to 20 μm. This was dried at 110 ° C. for 10 minutes under atmospheric pressure and normal pressure, fired at 400 ° C. for 30 minutes, and then rapidly cooled to form a surface layer. [Pressing rollers 1 to 8] were produced as described above. Moreover, the pressing roller 9 produced the pressing roller similarly except having not formed surface layer material.
Moreover, the contact angle at normal temperature with respect to the silicone oil of the surface layer of the produced pressure roller and the amount of F element were measured in the following procedure.

<Contact angle>
3 μL of silicone oil (KF-968-100CS manufactured by Shin-Etsu Chemical Co., Ltd.) is dropped on the surface of the pressure roller from a dispenser of an automatic contact angle meter (Kyowa Interface Science Co., Ltd., Dorop Master-500) at room temperature. After being placed, the angle formed between the pressure roller surface and the liquid droplets was calculated by the θ / 2 method. The contact angle was measured once for one drop of silicone oil as one set, and this was repeated 5 sets, and the average value of the obtained contact angles was used.

<F element amount>
The surface layer of the pressure roller was cut out at 1 × 1 cm and adhered to the sample holder with a carbon sheet. An X-ray photoelectron spectrometer (K-Alpha) manufactured by JEOL Ltd. was used, the X-ray source was MgKα (400 W), and the analysis region was 0.8 × 2.0 mm.

  Table 1 shows the measurement results of the contact angle of the surface layer of the produced pressure roller with the silicone oil and the amount of F element.

(Production of toner)
<Synthesis of unmodified polyester resin (low molecular polyester resin)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 84 parts by mass of bisphenol A propion oxide 3 mol adduct, 274 parts by mass of terephthalic acid, and dibutyltin oxide 2 parts by mass were added and reacted at 230 ° C. under normal pressure for 8 hours.
Next, the reaction solution was reacted for 5 hours under a reduced pressure of 10 to 15 mmHg to synthesize an unmodified polyester resin.
The obtained unmodified polyester resin had a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 5,600, and a glass transition temperature (Tg) of 55 ° C.

<Preparation of master batch (MB)>
1000 parts by weight of water, 540 parts by weight of carbon black (Printtex 35, manufactured by Degussa, DBP oil absorption = 42 ml / 100 g, pH = 9.5) and 1200 parts by weight of the unmodified polyester were mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). ) And mixed.
The mixture was kneaded for 30 minutes at 150 ° C. with two rolls, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron) to prepare a master batch.

<Synthesis of prepolymer>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 81 parts by mass of bisphenol A propylene oxide 2 mol adduct, 283 parts by mass of terephthalic acid, trimellitic anhydride 22 parts by mass of acid and 2 parts by mass of dibutyltin oxide were charged and reacted at 230 ° C. for 8 hours under normal pressure.
Subsequently, it was made to react under reduced pressure of 10-15mHg for 5 hours, and the intermediate polyester was synthesize | combined.
The obtained intermediate polyester has a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 9,600, a glass transition temperature (Tg) of 55 ° C., an acid value of 0.5, and a hydroxyl value of 49.

Next, 411 parts by mass of the intermediate polyester, 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate are charged in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and reacted at 100 ° C. for 5 hours. Thus, a prepolymer (polymer capable of reacting with the active hydrogen group-containing compound) was synthesized.
The free isocyanate content of the obtained prepolymer was 1.60% by mass, and the solid content concentration of the prepolymer (after standing at 150 ° C. for 45 minutes) was 50% by mass.

<Synthesis of ketimine (the active hydrogen group-containing compound)>
In a reaction vessel equipped with a stir bar and a thermometer, 30 parts by mass of isophoronediamine and 70 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound (the active hydrogen group-containing compound).
The amine value of the obtained ketimine compound (the active hydrogen group-containing compound) was 423.

<Synthesis of styrene-acrylic copolymer resin>
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 300 parts by mass of ethyl acetate was charged, and a styrene-acrylic monomer mixture (styrene / 2-ethylhexyl acrylate / acrylic acid / hydroxylethyl acrylate = 75/15 / 5/5) 300 parts by mass and 10 g of azobisisobutylnitrile were added and reacted at 60 ° C. for 15 hours under a normal pressure nitrogen atmosphere.
Next, 200 parts by mass of methanol was added to the reaction solution, and after stirring for 1 hour, the supernatant was removed and dried under reduced pressure to synthesize the styrene-acrylic copolymer resin.

<Dissolution of toner material and preparation of dispersion>
In a beaker, 10 parts by mass of the prepolymer, 60 parts by mass of the unmodified polyester, 130 parts by mass of ethyl acetate, and 30 parts by mass of a styrene-acrylic copolymer were stirred and dissolved.
Subsequently, the number of petroleum waxes shown in Table 2 (cycloparaffin 15% by mass, average molecular weight = 650) and 10 parts by mass of the masterbatch were charged, and a bead mill (“Ultra Visco Mill”; manufactured by Imex Corporation) was used. The raw material solution was prepared by three passes under the condition of a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / s, and 80% by volume of 0.5 mm zirconia beads, and 2.7 parts by mass of the ketimine was added. Dissolved to prepare [Dissolution of toner material or dispersions 1-6].
Table 2 shows the number of wax preparations in the toner material dissolved or dispersed liquid.

<Preparation of aqueous medium phase>
An aqueous medium phase was prepared by mixing and stirring 306 parts by mass of ion-exchanged water, 265 parts by mass of a 10% by mass tricalcium phosphate suspension, and 0.2 parts by mass of sodium dodecylbenzenesulfonate, and dissolving them uniformly.

<Emulsification or preparation of dispersion>
150 parts by mass of the aqueous medium phase is put in a container, and stirred at a rotational speed of 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). 100 parts by mass were added and mixed for 10 minutes to prepare [Emulsification or dispersion (emulsification slurry) 1-6].

<Removal of organic solvent>
In a Kolben equipped with a stirrer and a thermometer, 100 parts by mass of the [emulsified slurries 1 to 6] were charged, and the solvent was removed at 30 ° C. for 12 hours while stirring at a stirring peripheral speed of 20 m / min.

<Washing and drying>
After filtering 100 parts by mass of [Dispersion Slurries 1 to 6] under reduced pressure, 100 parts by mass of ion-exchanged water was added to the filter cake, followed by mixing with a TK homomixer (rotating at 12,000 rpm for 10 minutes) and filtration. did.
To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice.
To the obtained filter cake, 20 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added, mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (at 12,000 rpm for 10 minutes), and then filtered.
To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice.
Furthermore, 20 mass parts of 10 mass% hydrochloric acid was added to the obtained filter cake, mixed with a TK homomixer (at a rotation speed of 12,000 rpm for 10 minutes) and then filtered.
To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered twice to obtain a final filter cake.
The obtained final filter cake was dried with a circulating dryer at 45 ° C. for 48 hours, and sieved with an opening of 75 μm mesh to obtain [toner base particles 1 to 6].

<External processing>
Further, with respect to 100 parts by weight of [Toner Base Particles 1 to 6], 0.6 part by weight of hydrophobic silica having an average particle diameter of 100 nm, 1.0 part by weight of titanium oxide having an average particle diameter of 20 nm, and an average particle diameter Toners 1 to 6 were obtained by mixing 0.8 parts of 15 nm hydrophobic silica fine powder with a Henschel mixer.

  Table 3 shows the particle size distribution and the surface release agent exposure of the toner prepared as described above. Moreover, the measuring method is as follows.

<< Measurement of Volume Average Particle Size (Dv), Number Average Particle Size and Ratio (Dv / Dn) >>
The particle size distribution of the toner (toner base particles) was performed using a Coulter Multisizer.
That is, Coulter Multisizer III (manufactured by Coulter Co.) is used as a measuring device, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting number distribution and volume distribution is connected to a personal computer. Was used to prepare a 1 mass% NaCl aqueous solution. As a measurement method, 0.1 to 5 mL of a surfactant (alkylbenzene sulfonate) is added as a dispersant to 100 to 150 mL of the aqueous solution as the electrolytic solution, and 2 to 20 mg of a measurement sample is further added. Dispersion treatment was performed for about 1 to 3 minutes. Further, 100 to 200 mL of an electrolytic aqueous solution was put into another beaker, and the sample dispersion was added to a predetermined concentration therein, and 50,000 particles were used by the Coulter Multisizer III using a 100 μm aperture as an aperture. The average of was measured. The ratio (Dv / Dn) of both was calculated | required from the obtained volume average particle diameter (Dv) [micrometer] and number average particle diameter (Dn) [micrometer].

<< Measurement of exposure amount of toner surface release agent >>
The exposure amount of the surface release agent of the toner was measured by a hexane extraction method. 1.0 g of the toner base particles before adding the external additive is weighed, 7 ml of n-hexane is added, and the mixture is stirred with a roll mill at 120 rpm for 1 minute. The solution is suction filtered, and n-hexane is removed by a vacuum dryer. The mass (mg) of the removed component was defined as the surface release agent exposure (mg / g).

  Table 3 shows the volume average particle diameter (Dv), the number average particle diameter (Dn), the ratio (Dv / Dn), and the surface release agent exposure amount of the toner.

Next, a carrier was prepared as follows.
<Creation of carrier>
[Carrier coating film forming solution formulation]
・ Acrylic resin solution (solid content 50 wt%) 21.0 parts by mass ・ Guanamine solution (solid content 70 wt%) 6.4 parts by mass ・ Alumina particles 7.6 parts by mass [0.3 μm, specific resistance 10 ¹⁴ (Ω cm)]
Silicone resin solution 65.0 parts by mass [solid content 23 wt% (SR2410: Toray Dow Corning Silicone)]
Aminosilane 1.0 part by mass [solid content 100 wt% (SH6020: manufactured by Toray Dow Corning Silicone)]
・ Toluene 60 parts by mass ・ Butyl cellosolve 60 parts by mass

The said formulation was disperse | distributed for 10 minutes with the homomixer, and the blend coating film formation solution of the acrylic resin and silicone resin containing an alumina particle was obtained.
A fired ferrite powder [(MgO) _1.8 (MnO) _49.5 (Fe ₂ O ₃ ) _48.0 : average particle size; 35 μm] was used as the core material, and the coating film forming solution was applied to the surface of the core material. It was applied with a Spira coater (manufactured by Okada Seiko Co., Ltd.) to a thickness of 0.15 μm and dried.
The obtained carrier was baked by standing in an electric furnace at 150 ° C. for 1 hour.
After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 106 μm to obtain a carrier 1 having a weight average particle diameter of 35 μm.

  Each developer was prepared by uniformly mixing and charging the carrier 1 at a ratio of 7 parts by weight of toner 1 to 6 parts by weight with respect to 100 parts by weight using a tumbler mixer of a type in which the container rolls and stirs.

  Next, the obtained pressing rollers and developers were combined as in Examples 1 to 10 and Comparative Examples 1 to 3 in Table 4, and toner adhesion to the pressing roller was evaluated according to the following evaluation method. The results are shown in Table 4.

<< Evaluation of toner adhesion to pressure roller >>
A commercially available digital full-color multifunction peripheral (RICOH MPC6003 manufactured by Ricoh Co., Ltd.) is modified to produce an image forming apparatus as shown in FIG. 1 having a fixing device having a pressing roller as shown in FIG. It was. Using the evaluator, a halftone chart was output, and the pressing roller was taken out every 500 sheets and the presence or absence of toner adhesion was visually confirmed. Evaluation was made based on the following criteria in terms of the number of sheets passing the toner adhering to the pressure roller. The evaluations of ◎ to △ are acceptance criteria.

〔Evaluation criteria〕
A: Toner fixation does not occur even when 3,500 sheets are passed. ○: Toner fixation occurs when 2500 or more and less than 3500 sheets. Δ: Toner fixation occurs when 1500 or more and less than 2500 sheets. ×: Toner fixation occurs when less than 1500 sheets.

  The evaluation results are shown in Table 4.

  As in Examples 1 to 10, those having a contact angle of 30 ° to 50 ° with respect to the silicone oil on the surface of the pressure roller had a good toner fixing degree, while those of Comparative Examples 1 to 3 were good. As described above, it was confirmed that the toner having a contact angle at normal temperature with the silicone oil not satisfying the above range deteriorated the toner fixation.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Paper feed part 6 Registration roller 8 Photoconductor 10 Transfer device 14 Paper feed tray 16 Paper feed roller 18 Charging device 22 Developing device 22a Developing roller 24 Cleaning means 24a Blade 38 Branching claw 39 Automatic double-sided device 40, 40A Fixing Device 50 Control means 120 Transport guide and transport roller group 150 Exposure position 201, 202 Mirror 400 Pressure member 401, 401A Heated member 402, 402A Heat generation means 403 Press member 403A Press roller 405 Support member 406 Press pad 407 Heater substrate 408 Heating element 409 Holder 410, 412 Core metal 415 Support roller 416 Fixing roller 430 Paper discharge tray (paper discharge storage)
440 Writing unit 450 Device main body 460 Printing unit a, a ′, c Image area b, d Non-image area k1, k2, k3 Heat generation area n Nip s1 Preheating area Pa Recording material X Direction perpendicular to conveyance direction Y Conveyance direction

JP 2004-286922 A Japanese Patent No. 2861280 JP-A-6-95540 JP 2011-170051 A

Claims (6)

A heating means having a heating element;
An endless member to be heated that is in contact with the heating means on the inner peripheral side and is heated;
A pressure member which is arranged to be able to press a part of the heated member and forms a nip portion with the heated member;
A pressing member that is provided at a position facing the heat generating means across the heated member, and that presses the heated member toward the heat generating means;
A fixing device that conveys a recording material carrying an unfixed toner image formed of toner to the nip portion and fixes the unfixed toner image on the recording material;
The outermost layer of the pressing member includes a fluoropolymer;
The contact angle at normal temperature with respect to the silicone oil on the surface of the pressing member is 30 ° to 50 °.   The fixing device according to claim 1, wherein the fluoropolymer has a perfluoroalkyl group.   The fixing device according to claim 1, wherein an amount of F element on the surface of the pressing member detected by XPS (X-ray photoelectron spectroscopy) is 50 to 75 atomic% (number of atoms%). The toner contains at least a release agent,
The fixing device according to claim 1, wherein an exposure amount of the surface release agent of the toner is 9 to 13 mg / g with respect to 1 g of the toner.   An image forming apparatus comprising the fixing device according to claim 1. The image forming apparatus according to claim 5, wherein
The heat generating means has a heat generating area divided into a plurality of directions in a direction orthogonal to the conveying direction of the recording material,
The divided heat generation area heats the image portion to which the toner image has been transferred to a fixing temperature according to the position of the toner image on the recording material, and fixes the non-image portion to which the toner image has not been transferred to the fixing portion. An image forming apparatus that is controlled so that the temperature can be lower than a temperature.