JP5473301B2 - Image forming method - Google Patents

Description

  The present invention relates to a toner and an image forming method used in a printer, a copying machine, a facsimile, or the like using an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like.

  Conventionally, in an image forming apparatus, a contact heating type apparatus has been widely used as an apparatus for heating and fixing an unfixed toner image formed on a recording material as a permanently fixed image. In this contact heating type fixing device, a rotating member (hereinafter referred to as a fixing roller) whose surface temperature in contact with a recording material is heated to a predetermined fixing temperature is brought into contact with the recording material at a nip portion to perform recording. The unfixed toner image on the material is heat-fixed as a permanently fixed image.

  As a heating method for the fixing roller, there is a conventional internal heating method. In this method, heating means (heating source: heater or the like) is disposed inside the fixing roller, and the fixing roller is heated from the inside to heat the surface of the fixing roller to a predetermined fixing temperature. However, the internal heating method takes time because the entire roller needs to be heated, and is inferior in on-demand performance.

  Various studies have been made in order to cope with the on-demand property, and the surf fixing method which is a heating method using a film is a useful fixing method. This is a system in which the heater directly heats through the film, so that the heat of the heater can be efficiently applied to the recording material. However, the surf fixing may cause a problem that the film is torn during long-term use.

  As a new fixing method to eliminate such concerns, an external heating method (surface heating method) has been studied.

  Since the external heating type apparatus directly heats the fixing roller from the outside with a ceramic heater, a halogen heater, or the like, the surface of the fixing roller can be rapidly heated. Therefore, the warm-up time compared to the internal heating system and the time from when a print signal is received until the recording material on which the unfixed toner image is formed is heated and fixed (hereinafter referred to as the first printout time). Can be shortened. Along with these, on-demand is also improved, which is preferable. Moreover, since the above-mentioned malfunction does not arise from not using a film, it is preferable.

  As a technique related to such an external heating method, for example, there is a technique in which the inside of the fixing roller is thermally insulated and the outermost layer is made highly thermally conductive by inserting a heat conductive filler (see Patent Documents 1 and 2). However, although this technology shortens the warm-up time and increases on-demand, such a heat conductive filler has a very high affinity with toner, so it is disadvantageous for wrapping, and low temperature offset is likely to occur. There is room for improvement.

  In order to improve wrapping and low temperature offset, in Patent Document 3, PFA (copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) having high releasability is arranged on the surface layer to reduce the adhesiveness to paper. Techniques for making them disclosed are disclosed. However, if the surface layer portion is covered with PFA, the heat transfer efficiency is lowered, the fixing temperature becomes high and the on-demand property is inferior, so there is room for further improvement.

  Further, in order to improve the wrapping resistance, it is very effective to provide a release layer having excellent releasability from the recording material on the surface of the image heating member, and various studies have been made (Patent Documents). 4, 5, 6). However, the heat transfer efficiency from the image heating member to the recording material decreases due to the reduction of the heat capacity of the surface layer. Therefore, the heating device needs to give high energy to the image heating member. Also, the low-temperature offset resistance is not sufficient, leaving room for improvement.

  Accordingly, there is a need for an image forming method capable of fixing at a lower temperature and improving low temperature offset resistance.

  On the other hand, with respect to toner, a toner is disclosed in which a current measured by a thermally stimulated current measuring device has a specific value for the purpose of achieving both fixing properties and charging stability (see Patent Documents 7 to 10). However, there is a demand for a toner having further improved low-temperature fixability and glossiness compared to the toner described in the above patent document.

  For these reasons, in image forming methods that have an external heating type heat-fixing device, high speed and high-definition full-color images are currently required. Good low-temperature fixability and high image gloss are maintained. In addition, a toner and an image forming method that sufficiently satisfy the durability are desired.

JP 2004-317788 A JP 2007-121441 A JP 2004-86202 A JP 2003-173096 A JP 2002-278338 A JP 2003-186327 A JP-A-8-62885 JP 2004-279434 A JP 2004-301990 A JP 2005-43851 A

The present invention has been made to solve the above-mentioned problems of the prior art. That is, in the case of using a fixing member having a releasing layer is also low-temperature fixing property, excellent in low-temperature offset property and gloss, even when performing multiple prints, the image forming how stress resistance is good Is to provide.

The above object is achieved more can be achieved in the following image forming how.

A charging step of charging the electrostatic latent image carrier with charging means, an exposure step of exposing the charged electrostatic latent image carrier to form an electrostatic latent image, and developing the electrostatic latent image with toner Development process for forming a toner image, transfer process for transferring the toner image to a recording material with or without an intermediate transfer member, and an image heating member capable of rotating the recording material carrying the toner image with a pressure member In an image forming method having a fixing step of fixing by heating and pressing by passing through a nip formed by
The image heating member is
(I) A roller having a release layer having a thickness of 5 to 200 μm as the outermost layer, a heat storage layer as a lower layer thereof, and further having an elastic layer as a lower layer thereof, per unit area of the heat storage layer The heat capacity is 100 to 600 J / (m ² · K),
(Ii) heated from the outermost surface by an external heating means,
(Iii) containing a heat conductive filler having a thermal conductivity of 5.0 W / (m · K) or more, the heat conductive filler being an Al and / or Zn compound;
(Iv) When the surface is measured by EPMA (electron beam microanalyzer) , the abundance ratio of Al and / or Zn elements derived from the heat conductive filler is 0.10 to 0.10 to the total amount of elements detected by EPMA. 3.00% by mass ,
The toner is
(I) having toner particles containing at least a binder resin, a colorant, and wax, and inorganic fine powder;
(Ii) The current value of the thermally stimulated current measured at the first temperature rise by the thermally stimulated current measuring device has a main peak (P1) at 60 to 100 ° C., and the absolute value of the current indicating P1 is 0 1 × 10 ^{−14 to} 1000.0 × 10 ⁻¹⁴ A, and the current value of the thermally stimulated current measured at the second temperature rise has a peak (P2) at least from 60 to 110 ° C. and it is shown temperature T1 (° C.) and a temperature T2 (° C.) indicating the P2 but,
−15 ≦ T2−T1 ≦ 15
Satisfy the relationship
An image forming method.

  According to the present invention, even when a fixing member having a release layer is used, an image having excellent low temperature fixing property, low temperature offset resistance and glossiness, and excellent stress resistance even when printing a large number of sheets. Can be obtained.

  Hereinafter, embodiments of the toner and the image forming method of the present invention will be described.

  The present inventors have intensively studied an image forming method including a fixing step of fixing using an image heating member having a release layer as an outermost layer, a heat storage layer as a lower layer, and an elastic layer as a lower layer. As a result of intensive investigations with regard to the current value measured by the thermally stimulated current measuring device for the optimum toner to be used in this image forming method, a toner and an image forming method for solving the above-mentioned problems are obtained. As a result, the present invention was completed.

The image forming method of the present invention comprises a charging step of charging an electrostatic latent image carrier with a charging means, an exposure step of exposing the charged electrostatic latent image carrier to form an electrostatic latent image, and the electrostatic A development process for developing a latent image with toner to form a toner image, a transfer process for transferring the toner image to a recording material with or without an intermediate transfer member, and pressurizing the recording material carrying the toner image In an image forming method having a fixing step of fixing by heating and pressing by passing a nip formed by a member and a rotatable image heating member,
The image heating member is heated from the surface of the outermost layer by an external heating means, the image heating member has a release layer having a thickness of 5 to 200 μm as the outermost layer, and has a heat storage layer as the lower layer. The image heating member further includes a heat conductive filler having a heat conductivity of 5.0 W / (m · K) or more, and the heat conductive filler is an Al and / or Zn compound. The abundance ratio of Al and / or Zn elements derived from the heat conductive filler when the surface of the image heating member is measured by EPMA (electron beam microanalyzer) is based on the total amount of elements detected by EPMA. 0.10 to 3.00 mass%, and the heat capacity per unit area of the heat storage layer is 100 to 600 J / (m ² · K),
The toner includes toner particles containing at least a binder resin, a colorant, and a wax, and an inorganic fine powder. The current of the thermally stimulated current measured at the first temperature rise by the thermally stimulated current measuring device of the toner. The value has a main peak (P1) at least at 60 to 100 ° C., and the absolute value of the current indicating P1 is 0.1 × 10 ^{−14 to} 1000.0 × 10 ⁻¹⁴ A, and the second rise The current value of the thermal stimulation current measured at the time has a peak (P2) at least at 60 to 110 ° C., and the relationship between the temperature T1 (° C.) indicating the P1 and the temperature T2 (° C.) indicating the P2 is:
−15 ≦ T2−T1 ≦ 15
The image forming method is characterized by the above.

  First, the image heating member of the present invention will be described.

  The image heating member of the present invention has a three-layer structure of a release layer, a heat storage layer, and an elastic layer in order from the surface of the image heating member, and the release layer is 5 μm or more and 200 μm or less. This release layer is an important configuration in using various media and toners in combination in order to remarkably enhance the release effect between the image heating member and the toner. However, since the thermal conductivity of the release layer is low, the amount of heat required for fixing increases due to loss when the amount of heat is applied by the heater. According to the study by the present inventors, the range of the release layer thickness capable of suppressing the loss of heat while providing high release properties was 5 μm or more and 200 μm or less. If the thickness of the release layer is less than 5 μm, the releasability between the image heating member and the toner is lowered, and problems during fixing such as low temperature offset occur. If it exceeds 200 μm, the low temperature offset is improved, but the heat capacity of the surface is lowered, so the temperature of the heater must be increased. For this reason, it is important that the thickness of the release layer is 5 μm or more and 200 μm or less, and more preferably 5 μm or more and 100 μm or less.

  In such an image heating member configuration, as a result of repeated investigations for lowering the fixing temperature, it has been important to control the physical properties and existence state of the heat conductive filler and the physical properties of the heat storage layer. In addition, the heat conductive filler of this invention contains Al and / or Zn. This is because when Al and / or Zn is contained, the filler easily obtains high thermal conductivity, and is very easy to apply to the image heating member of the present invention.

That is, in the present invention, (A) the presence ratio of Al and / or Zn elements derived from the heat conductive filler when the surface of the image heating member is measured by EPMA (electron beam microanalyzer) is detected by EPMA. It is 0.10 mass% or more and 3.00 mass% or less with respect to element amount, (B) Thermal conductivity of a heat conductive filler is 5.0 W / (m * K) or more, (C) Heat storage layer It was important to control the heat capacity from 100 J / (m ² · K) to 600 J / (m ² · K).

  First, (A) will be described. The image heating member of the present invention has a three-layer structure of a release layer, a heat storage layer, and an elastic layer. However, as described above, since there is a release layer having a low thermal conductivity, the thermal conductivity of the surface is lowered, so that the fixing temperature is raised. Then, when examination which raises the heat conductivity of a mold release layer was conducted, it discovered that fixing temperature could be lowered significantly by making a small amount of heat conductive fillers exist in the mold release layer surface. In the present invention, EPMA was used as a method for detecting the heat conductive filler on the surface of the release layer. EPMA measures an element existing at a depth of several μm from the surface, and detected Al and Zn elements correspond to the amount of thermally conductive filler existing at a depth of several μm from the surface. According to the study by the present inventors, the above effect was obtained when the ratio of Al and / or Zn detected by EPMA measurement was 0.10% by mass or more based on the total amount of elements detected. As the reason for this, the present inventors consider as follows. When the release layer receives heat from the heater, the heat reaches the heat storage layer through the release layer and is stored. At this time, since the release layer has low thermal conductivity, a heat loss is generated. Here, if there is a heat conductive filler in an amount such that the Al and / or Zn abundance ratio is 0.10% by mass or more on the surface of the release layer, the heat is efficiently supplied to the heat storage layer via the highly heat conductive filler. Communicated. Thus, it is considered that heat loss is unlikely to occur, and the image heating member can be heated to a desired temperature at the minimum necessary heater temperature.

  For this reason, the greater the amount of the heat conductive filler on the releasable surface, the higher the thermal conductivity and the greater the effect of lowering the fixing temperature. However, in general, the heat conductive filler containing Al and / or Zn has a higher affinity with the toner than the rubber forming the roller. For this reason, if a large amount is contained in the release layer, the release effect is lost and a low temperature offset occurs. According to the study by the present inventors, when the Al and / or Zn presence ratio detected by EPMA measurement is 3.00 mass% or less, the low temperature offset resistance can be satisfied while lowering the fixing temperature.

  Therefore, the surface of the image heating member is 0.10% by mass or more and 3.00% by mass with respect to the total amount of elements in which the presence ratio of Al and / or Zn elements is measured when the surface of the image heating member is measured by EPMA. The following amount of thermally conductive filler is required. If it is less than 0.10% by mass, there is not enough filler to mediate the surface and the heat storage layer, and the amount of heat received from the heater is greatly lost before being transferred to the heat storage layer, and the fixing temperature rises. On the other hand, if it exceeds 3.00% by mass, the amount of the heat conductive filler is large, so that the adhesive force between the release layer and the toner is increased, and the low temperature offset resistance is remarkably deteriorated.

  Next, the thermal conductivity of the thermal conductive filler (B) will be described. The heat conductive filler in the image heating member configuration of the present invention needs to efficiently transfer heat from the release layer surface to the heat storage layer. For this reason, it is necessary to have a high thermal conductivity. Specifically, if it is 5.0 W / (m · K) or more, heat can be efficiently transferred to the heat storage layer even with a small amount of filler on the surface. I can do it. If it is less than 5.0 W / (m · K), the heat loss increases as the heat transfer efficiency decreases, and the fixing temperature increases.

  When the heat conductive filler is slightly present on the surface of the image heating member by (A) and the heat conductivity of the heat conductive filler is adjusted to be high by (B), the surface of the heat conductive filler as described in (A). And the effect of thermally mediating the heat storage layer is greatly increased. Due to the synergistic effect of (A) and (B), the image heating member can achieve both high releasability and high heat transfer efficiency between the surface and the heat storage layer, thereby improving low temperature offset resistance and lowering the fixing temperature. I can do it.

Next, the heat capacity of the heat storage layer (C) will be described. The image heating member in the present invention comprises means for heating from the outside. Here, considering the movement of heat, the heat generated by the heater is received by the image heating member and further applied to the toner on the recording material to be fixed. However, since the heater and the recording material fixing portion are separated from each other, heat must be held in the heat storage layer until the portion heated by the heater reaches the fixing portion. Therefore, it is necessary to increase the heat capacity of the heat storage layer. Specifically, 100 J / m ² K or more was necessary. On the other hand, if the heat capacity is too large, the temperature of the surface of the image heating member increases slowly. Therefore, the on-demand property is inferior and the amount of heat necessary for fixing increases. In order to eliminate such adverse effects, the heat capacity of the heat storage layer was required to be 600 J / (m ² · K) or less. Therefore, it is important that the heat quantity of the heat storage layer is 100 J / (m ² · K) or more and 600 J / (m ² · K) or less. When the heat capacity is less than 100 J / (m ² · K), the amount of heat radiation increases and the recording material is easily deprived of heat. For this reason, the heat energy required by the image heating member during fixing increases. If it exceeds 600 J / (m ² · K), the temperature rise rate of the image heating member is lowered, the warm-up time is extended, and the on-demand property is inferior.

  As described above, in the image heating member of the present invention, after the image heating member has a three-layer configuration, (A) adjustment of the amount of the heat conductive filler on the surface, (B) adjustment of the heat conductivity of the heat conductive filler, C) Controlling the heat capacity of the heat storage layer was important. The object of the present invention can be achieved by a combination of the image heating member satisfying (A), (B) and (C) and the toner described below.

  Next, the toner used in the image forming method of the present invention will be described.

  In the image heating member configuration of the present invention, investigations were made to further improve low-temperature offset resistance and to reduce the fixing temperature. In addition to the above-mentioned image heating member, it is important to control the toner surface composition and the internal wax presence state. Met.

Specifically, the toner has toner particles containing at least a binder resin, a colorant, and a wax, and an inorganic fine powder, and the thermal stimulation current measured at the first temperature rise by the thermal stimulation current measuring apparatus for the toner. Has a main peak (P1) at least at 60 to 100 ° C., and the absolute value of the current indicating P1 is 0.1 × 10 ^{−14 to} 1000.0 × 10 ⁻¹⁴ A, 2 The current value of the thermal stimulation current measured at the time of the second temperature rise has a peak (P2) at least at 60 to 110 ° C., and the relationship between the temperature T1 (° C.) indicating the P1 and the temperature T2 (° C.) indicating the P2 But,
−15 ≦ T2−T1 ≦ 15
The toner configuration is characterized by that.

According to the study by the present inventors, P1 is due to the charge relaxation phenomenon accompanying melting of the wax component existing near the toner particle surface, and the absolute value of the current indicating P1 is the amount of wax present near the toner particle surface. Is estimated to be proportional to The absolute value of the current indicating P1 is preferably 0.1 × 10 ^{−14 to} 1000.0 × 10 ⁻¹⁴ A, more preferably 3.0 × 10 ^{−14 to} 90.0 × 10 ⁻¹⁴ A. More preferably, it is 4.0 × 10 ^{−14 to} 60.0 × 10 ⁻¹⁴ A. If it is less than 0.1 × 10 ⁻¹⁴ A, the amount of wax present in the vicinity of the toner particle surface is too small, so that the releasability of the image heating member from the release layer decreases, Low temperature offset resistance deteriorates. When it exceeds 1000.0 × 10 ⁻¹⁴ A, the amount of wax existing in the vicinity of the toner particle surface is excessive, and the charging stability may deteriorate. Moreover, when temperature T1 (degreeC) which shows P1 is lower than 60 degreeC, high temperature offset resistance may fall, and when it is higher than 100 degreeC, low temperature offset resistance may deteriorate, and it is unpreferable.

P2 is due to the phenomenon of charge relaxation accompanying the melting of the wax component dissolved from the toner particles when heated to 100 ° C., and the absolute value of the current indicating P2 is proportional to the amount of wax contained in the toner. It is estimated to be. The absolute value of the current indicating P2 is more preferably 1.0 × 10 ^{−14 to} 50.0 × 10 ⁻¹⁴ A. If it is less than 1.0 × 10 ⁻¹⁴ A, the amount of wax present in the toner particles is too small, and the low-temperature fixability may be lowered. If it exceeds 50.0 × 10 ⁻¹⁴ A, the amount of wax present in the toner particles is excessive, and the development streaks and charging stability are reduced.

  When the relationship between the temperature T1 (° C.) indicating P1 and the temperature T2 (° C.) indicating P2 is −15 ≦ T2−T1 ≦ 15, the image heating apparatus used in the present invention is The toner exhibits excellent fixing properties. When T1 is larger than T2, it is considered that heat is not easily transmitted to the wax existing in the vicinity of the toner particle surface, and this difference becomes remarkable when the amount of inorganic fine powder externally added to the toner particle is increased. . On the contrary, when T1 is smaller than T2, it is considered that the wax existing in the vicinity of the toner particle surface is likely to be dissolved, and this difference becomes remarkable when the shell part of the toner particle having the core / shell structure is increased. become. If T2−T1 <−15, there are too many external additives on the surface of the toner particles, and development streaks and low-temperature offset resistance deteriorate. When T2-T1> 15, the shell layer becomes too thick, and charging stability and low-temperature fixability deteriorate.

  The toner of the present invention has a higher peak (P3) on the higher temperature side than P2 measured at the second temperature rise in the thermal stimulation current measurement in order to realize a higher gloss image for higher image quality. Need to control.

P3 is due to a charge relaxation phenomenon accompanying softening of the low molecular weight resin component dissolved from the toner particles by being heated to 100 ° C. The absolute value of the current indicating P3 is the low molecular weight component contained in the toner particles. It is estimated that it is proportional to the amount of resin. The absolute value of the current indicating P3 is preferably 1.0 × 10 ^{−14 to} 50.0 × 10 ⁻¹⁴ A. If it is less than 1.0 × 10 ⁻¹⁴ A, the resin content of the low molecular weight component present in the toner particles is too small and the glossiness is lowered. When it exceeds 50.0 × 10 ⁻¹⁴ A, the amount of low molecular weight resin present in the toner particles is excessive, and the development streak and the charging stability are lowered. The temperature T3 (° C.) indicating P3 is preferably 85 ° C. or higher. If it is lower than 85 ° C., the high temperature offset resistance may be lowered, and if it is higher than 110 ° C., the gloss may be lowered.

  FIG. 1 is a graph showing the current measured at the first temperature rise with the thermally stimulated current measuring device of the toner of the present invention (toner 1 of the embodiment), and FIG. 2 is a graph showing the current measured at the second temperature rise. Shown in

  The toner of the present invention preferably has a weight average particle diameter (D4) of 3.0 to 9.0 μm in order to faithfully develop finer latent image dots in order to improve image quality. 4.0 to 7.8 μm is more preferable, and 5.0 to 6.5 μm is even more preferable.

  The image heating member (hereinafter also referred to as a fixing roller) of the present invention will be described more specifically.

  As shown in FIG. 3, the image heating member 30 of the present invention forms an elastic layer (hereinafter also referred to as a heat insulating elastic layer) 32 having a low thermal conductivity and elasticity on the outer periphery of a cored bar 31. A heat storage layer 33 is formed outside the heat insulating elastic layer 32, and a release layer (not shown) is further formed outside.

  The metal core 31 of the image heating member of the present invention is formed of, for example, a metal material such as aluminum, iron, or SUM material, or another rigid material such as ceramic. Since the core 31 is insulated from the surface of the fixing roller by the heat insulating elastic layer 32, it may have low thermal conductivity and low heat capacity. The form may be a hollow cylinder.

  The heat insulating elastic layer 32 formed on the outer periphery of the cored bar 31 is a rubber layer having a low thermal conductivity, and the thermal conductivity is adjusted to be smaller than that of the heat storage layer 33. In the present invention, it is preferable that the elastic layer has a thermal conductivity of 0.15 W / (m · K) or less because the heat quantity of the heat storage layer is difficult to escape to the cored bar and the loss of heat quantity is eliminated.

  The thickness of the heat insulating elastic layer 32 is not particularly limited, but is 1.0 mm or more and 5.0 mm or less in order to configure the fixing roller 30 having a small diameter without having an effective heat insulating property and a large heat capacity. Preferably it is 2.0 mm or more and 4.0 mm or less.

  The heat insulating elastic layer is fired after forming a compound in which a hollow filler is mixed with an organopolysiloxane composition or a compound in which a water-absorbing polymer and water are mixed in an organopolysiloxane composition from the viewpoint of durability and heat insulating properties. And what was formed by hardening is preferable.

  A method for forming the heat insulating elastic layer 32 will be exemplified below.

  For example, a silicone rubber composition, which is a silicone rubber composition comprising 100% by mass of a thermosetting organopolysiloxane composition and 0.1% by mass or more and 200.0% by mass or less of a hollow filler having an average particle size of 500 μm or less. A balloon rubber layer formed by heat curing the product.

  Here, as the hollow filler, there is a microballoon material or the like that reduces the thermal conductivity like sponge rubber by having a gas portion in the cured product. Examples of the microballoon material include glass balloons, silica balloons, carbon balloons, phenol balloons, acrylonitrile balloons, vinylidene chloride balloons, alumina balloons, zirconia balloons, and shirasu balloons.

  The amount of the hollow filler is 0.1 to 200.0 parts by mass, preferably 0.2 to 150.0 parts by mass, with respect to 100 parts by mass of the thermosetting organopolysiloxane composition. Hereinafter, it is more preferably 0.5 parts by mass or more and 100.0 parts by mass or less. In this case, it is preferable to blend so that the content of the hollow filler in the silicone rubber composition for a fixing roller is 10% to 80%, particularly 15% to 75% by volume. If the volume ratio is too small, the decrease in thermal conductivity tends to be insufficient, and if it is too large, molding and blending are difficult, and the molded product may be brittle without rubber elasticity.

  For example, the silicone rubber heat insulation layer 32 may be formed by a method of adding a water-absorbing polymer and water. Examples of the silicone rubber composition include 100 parts by mass of an organopolysiloxane composition, 0.1 to 50.0 parts by mass of a water-absorbing polymer, 10 to 200 parts by mass of water, and other platinum compound catalysts. To form a composition to which a curing catalyst such as SiH and a crosslinking agent such as SiH polymer are added. Thereafter, this may be thermoformed to form the heat insulating elastic layer 32.

  In this case, heating is performed in the following three or two stages. That is, in the first stage, the silicone base polymer is not substantially cured and does not evaporate, and is heated at 100 ° C. or lower, preferably 50 ° C. or higher and 80 ° C. or lower for 10 hours to 30 hours. Mold. Next, in the second stage, the molded product is heated at 120 ° C. or more and 250 ° C. or less, preferably 120 ° C. or more and 180 ° C. or less for 1 to 5 hours, and the contained water and impurities contained in water are contained. Evaporate moisture. And in the final third stage, the obtained porous body is heated at 180 ° C. or higher and 300 ° C. or lower, preferably 200 ° C. or higher and 250 ° C. or lower for 2 to 8 hours to advance the curing, thereby achieving the desired porous property. A silicone rubber layer of a rubbery elastic body is completed.

  Therefore, it is desirable that the heat insulating elastic layer 32 is formed of a liquid silicone composition mainly composed of a balloon such as a microballoon or an organopolysiloxane containing a water-absorbing polymer. The heat insulating elastic layer thus obtained is superior in heat insulation and durability and has less thermal expansion than the sponge silicone rubber heat insulating layer or the solid rubber heat insulating layer.

  Next, the heat storage layer 33 formed on the outer periphery of the heat insulating elastic layer 32 will be described. The heat storage layer 33 is a solid rubber layer in which a layer in which a powdery heat conductive filler (hereinafter also simply referred to as “filler”) is mixed with, for example, silicone rubber or fluororubber is formed on the heat insulating elastic layer 32. It is mentioned as a suitable form. It is preferable for the heat storage layer to have the above configuration because the amount of heat applied to the heat storage layer via the release layer diffuses quickly throughout the heat storage layer.

  It is important that the thermal conductivity of the heat storage layer is higher than that of the heat insulating elastic layer 32. Preferably, the thermal conductivity is higher than that of general solid rubber, and it is desirable to set it to 0.30 W / (m · K) or more.

  By making the thermal conductivity of the internal heat insulating layer lower than the thermal conductivity of the heat storage layer, the heat transferred from the surface of the fixing roller is unevenly distributed in the heat storage layer near the surface, and is easily maintained. Further, by increasing the thermal conductivity of the heat storage layer, heat can be absorbed and released in the heat storage layer quickly.

  The thickness of the heat storage layer 33 is preferably 20 μm or more and 500 μm or less.

  The heat storage layer 33 in which the filler is dispersed and the heat capacity is increased has elasticity while having elasticity. For this reason, if the heat storage layer is too thick, the surface of the fixing roller becomes hard and the adhesion to the recording material is deteriorated. Therefore, it becomes difficult to perform uniform toner image fixing. For this reason, as for the thermal storage layer 33, 500 micrometers or less are desirable.

  On the other hand, if the heat storage layer is too thin, it is difficult to uniformly disperse the filler and make the heat capacity uniform, which causes uneven fixing. Therefore, the heat storage layer 33 is preferably 20 μm or more.

  The heat conductive filler used in the present invention has a heat conductivity of 5.0 W / (m · K) or more. The shape of the filler may be any shape. In the present invention, the heat conductive filler contains Al and / or Zn. These are essential because they have high thermal conductivity and tend to lower the fixing temperature. Examples of the heat conductive filler that can be used in the present invention include powdered heat conductive fillers such as alumina, zinc oxide, aluminum nitride, zinc nitride, metal aluminum, metal zinc, an aluminum-containing alloy, and a zinc-containing alloy. .

  The mixing amount of the heat conductive filler is preferably 10 to 50% by mass because the on-demand property is enhanced and heat can be easily retained. When the mixing amount of the heat conductive filler is 10% by mass or more, the heat capacity of the heat storage layer is sufficiently increased, so that the fixing temperature of the image heating member tends to be lowered. On the other hand, when it is 50% by mass or less, the heat capacity of the heat storage layer becomes appropriate, so that the rate of temperature increase increases and the warm-up time tends to be shortened.

  Any method can be used as the method for producing the heat storage layer of the present invention. For example, methods such as dipping coating, spray coating, and ring coating in which a liquid resin is coated and formed using a cylindrical coating head around a cylindrical core metal. In particular, ring coating can be preferably used because the heat storage layer can be formed uniformly.

  FIG. 4 shows an example of a ring coating apparatus. A column 72 is vertically mounted on the gantry 71, and a precision ball screw 73 is vertically mounted on the gantry 71 and the column 72. Two linear guides 84 are attached to the column 72 in parallel with the precision ball screw 73. The LM guide 74 is connected to a linear guide 84 and a precision ball screw 73 so that a rotary motion is transmitted from a servo motor 75 via a pulley 76 so that the LM guide 74 can be raised and lowered. A ring-shaped coating head 78 for discharging the coating liquid is attached to the column 72 on the outer peripheral surface of the cylindrical core body 85. Further, a bracket 77 is mounted on the LM guide 74, and a workpiece lower holder 79 that holds and fixes the core body 85 is vertically mounted on the bracket 77, and the workpiece upper holder that holds the opposite core body 85. A central axis 80 is attached to the upper portion of the bracket 77, and the work upper holding tool is disposed so as to be concentric with the work lower holding tool 79 and holds the core body 85.

  The center axis of the ring-shaped coating head 78 is supported so as to be parallel to the moving direction of the workpiece lower holder 79 and the workpiece upper holder 80. Further, when the workpiece lower holder 79 and the workpiece upper fixture 80 are moved up and down, the center axis of the discharge port that is an annular slit opened inside the coating head 78, the workpiece lower holder 79, and the workpiece upper holder are held. The center axis of the tool 80 is adjusted to be concentric. With such a configuration, the central axis of the discharge port formed as an annular slit of the coating head 78 can be aligned with the central axis of the core body 85, and the inner peripheral surface of the ring-shaped coating head and the core body A uniform gap is formed between the outer peripheral surface of 85.

  The coating solution supply port 81 is connected to a material supply valve 83 via a coating solution conveying pipe 82. The material supply valve 83 includes a mixing mixer, a material supply pump, a material fixed amount discharge device, a material tank, and the like in front of the material supply valve 83, and can discharge a fixed amount (a constant amount per unit time) of the coating liquid.

  In order to keep the temperature in the circumferential direction constant in the process of semi-curing the unvulcanized liquid rubber formed on the outer periphery of the core body and the process of curing and bonding the semi-cured liquid rubber and the resin liquid after application lamination It is preferable to use a method of heating while rotating the rubber roller. As the heat source, a far-infrared ceramic heater, a near-infrared heater, a lamp heater, a UV heater, a micro heater, or the like that can heat the rubber roller without contact is desirable.

  A plurality of these heat sources are arranged at regular intervals in the longitudinal direction of the rubber roller in order to continuously change the heating temperature from both ends of the rubber roller toward the center. The number of heat sources is appropriately determined according to the heating temperature change pattern in the longitudinal direction of the rubber roller, but as the number increases, the temperature change in the longitudinal direction of the rubber roller can be controlled delicately and accurately. It becomes possible.

  The image heating member of the present invention forms a release layer (not shown) on the outer periphery of the heat storage layer 33 (FIG. 3). The release layer is often formed of silicone rubber, fluororubber, fluororesin or the like. In the present invention, a solid rubber layer mainly composed of fluororubber is preferable because it has high releasability from the toner and stability of the surface of the release layer. Here, the “main component” refers to a component that occupies 70% by mass or more with respect to all components of the release layer.

  As a method for forming the release layer, any method such as dipping coating using a dispersion, spray coating, ring coating, etc. can be used as in the case of the heat storage layer. Among them, ring coating can be preferably used because the filler can be unevenly distributed in the vicinity of the surface of the heat storage layer when the release layer is formed.

  In the image heating member of the present invention, it is also important to control the roughness of the image heating member surface. Specifically, Rz on the surface of the image heating member is preferably 1.0 to 10.0 μm. When Rz is 1.0 to 10.0 μm, the specific surface area of the surface of the image heating member increases, and heat can be efficiently stored in the image heating member during heating from the outside. Further, since moderate unevenness exists, the releasability from the toner can be improved.

  When the Rz on the surface of the image heating member is 1.0 μm or more, the contact area between the toner and the image heating member is optimized, and the low temperature offset tends to be improved. Further, if the Rz on the surface of the image heating member is 10.0 μm or less, the unevenness on the surface of the image heating member can be made appropriate, so that uniform and efficient heat can be applied to the toner, so that the fixing temperature can be kept low. There is a trend.

  An example of a method for controlling the surface roughness Rz is a method of mechanically polishing the surface. As the surface roughening method, a known polishing method such as polishing by adhering abrasive particles or abrasive particles to a tape or paper and pressing it can be used. Further, a sand blasting method in which abrasive particles are hit against the surface can be used. Among these, when polishing is performed using polishing paper, the control of Rz is easy and can be preferably used.

  The image heating member of the present invention preferably has an appropriate hardness. When the image heating member has an appropriate hardness, the releasability from the toner is enhanced. Specifically, the micro hardness of the heating member is preferably 30 to 68 °. When it is 30 ° or more, the nip area can be maintained in an appropriate region even when the pressure at the fixing nip portion is set to a desired value, so that the low temperature offset tends to be improved. When the angle is 68 ° or less, the hardness of the image heating member is optimized, the fixing nip area is also optimized, and the fixing temperature tends to be lowered.

  The image heating member of the present invention preferably has a configuration capable of quickly applying heat to the recording material after receiving the amount of heat from the heater. Therefore, it is desirable that the fixing roller 30 has a small diameter, and the outer diameter is preferably in the range of 5 mm to 20 mm.

  The toner of the present invention will be described more specifically.

  The toner obtained by the present invention has toner particles containing at least a binder resin, a colorant, and wax, and inorganic fine powder.

  The toner particles can be produced by a pulverization method, but the effects of the present invention can be obtained. However, the toner particles can be produced by a polymerization method such as emulsion polymerization, dispersion polymerization, suspension polymerization, or seed polymerization. It is preferable to. Among these, it is more preferable to produce toner particles by suspension polymerization.

  As the binder resin, known binder resins used for toners can be used. Examples of the polymerizable monomer for producing the binder resin include styrene monomers, acrylic esters, and methacrylic esters. These polymerizable monomers can be used alone or in combination. Among the polymerizable monomers described above, it is preferable from the viewpoint of toner development characteristics and durability that the binder resin is formed by using styrene or a styrene derivative alone or in combination with other polymerizable monomers.

  In order for the current value measured by the thermally stimulated current measuring device to show a peak in the temperature range of the present invention, it is preferable that a resin having a low molecular weight component is present in the toner. This can be achieved by controlling the molecular weight of the binder resin by adding a chain transfer agent or a crosslinking agent when toner particles are produced by a polymerization method. It can also be achieved by preparing a low molecular weight resin in advance and adding the low molecular weight resin to the polymerizable monomer composition to form toner particles. When a low molecular weight resin is added, the weight average molecular weight (Mw) of the low molecular weight resin is preferably 2000 or more and 7000 or less. Examples include low molecular weight polystyrene, low molecular weight styrene-acrylate copolymer, A low molecular weight styrene / acrylic copolymer may be mentioned. The addition amount is preferably 1 to 50 parts by mass, more preferably 5 to 35 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin.

  The toner of the present invention contains a colorant as an essential component in order to impart coloring power. Examples of the colorant preferably used in the present invention include the following organic pigments, organic dyes, and inorganic pigments.

  Examples of organic pigments or organic dyes as cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Specific examples include the following. C. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. Pigment blue.

  Examples of the organic pigment or organic dye as the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds. Specific examples include the following. C. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 150, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. Pigment Red 254.

  Examples of the organic pigment or organic dye as the yellow colorant include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include the following. C. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. Pigment Yellow 194.

  Examples of the black colorant include carbon black and those prepared by using the above yellow colorant / magenta colorant / cyan colorant to black.

  These colorants can be used alone or in combination, and further in a solid solution state. The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

  Examples of the wax component that can be used in the toner of the present invention include the following. Paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof according to Fischer-Tropsch method, polyolefin wax and derivatives thereof such as polyethylene and polypropylene, carnauba wax, candelilla Natural waxes such as waxes and derivatives thereof (the derivatives include oxides, block copolymers with vinyl monomers, graft modified products), fatty acids such as higher aliphatic alcohols, stearic acid, palmitic acid, acid amide waxes, esters Waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, and silicone waxes. These wax components may be used alone or in combination of two or more.

  Among the waxes, the wax component used in the present invention more preferably includes a hydrocarbon wax. Among them, when a hydrocarbon wax by the Fischer-Tropsch method or paraffin wax is used, the offset resistance to the fixing roller can be kept good while maintaining the developability particularly in the contact development for a long time. The added amount of wax is preferably 5 to 25 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin.

  A resin for the purpose of improving the dispersibility and fixing property of the material or the image characteristics may be contained in the polymerizable monomer composition. Examples of the resin used include polycarbonate, polyethylene, silicone resin, polyester resin, and aliphatic or alicyclic hydrocarbon resin. In particular, by adding a polar resin polar resin having a carboxyl group such as a polyester resin or a polycarbonate resin, the shell portion of the core-shell structure of the toner can be reinforced. These can be used alone or in combination. Among these, a polyester resin is preferable as the resin used by adding to the polymerizable monomer composition. The addition amount of the polyester resin is preferably 1 to 25 parts by mass and more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin.

  In the present invention, a charge control agent may be added to the toner particles for the purpose of controlling the chargeability of the toner. When toner particles are produced by a polymerization method, the charge control agent is preferably one having little polymerization inhibition and aqueous phase migration. Examples of the positive charge control agent include the following. Examples include triphenylmethane dyes, quaternary ammonium salts, guanidine derivatives, imidazole derivatives, amine compounds, and nigrosine dyes. Examples of the negative charge control agent include the following. Examples thereof include metal-containing salicylic acid copolymers, metal-containing monoazo dye compounds, urea derivatives, styrene-acrylic acid copolymers, and styrene-methacrylic acid copolymers. The addition amount of these charge control agents is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin.

  Examples of the polymerization initiator used when the toner particles are produced by a polymerization method include azo compounds such as 2,2′-azobis- (2,4-dimethylvaleronitrile) and 2,2′-azobisisobutyronitrile. Diazo polymerization initiators; peroxide polymerization initiators such as benzoyl peroxide, t-hexyl peroxypivalate, and t-butyl peroxypivalate.

  In the present invention, when a polymerization toner is produced, a known surfactant or organic or inorganic dispersant can be used as a dispersion stabilizer. Since inorganic dispersants are generally large in size, dispersion stability can be obtained due to steric hindrance. Therefore, stability is not easily lost even when the reaction temperature is changed, and washing is easy. Therefore, an inorganic dispersant can be used more preferably. Examples of such inorganic dispersants include the following. Polyvalent metal phosphates such as calcium phosphate and magnesium phosphate; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasuccinate and barium sulfate; calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, Examples thereof include inorganic oxides such as alumina.

  These inorganic dispersants may be used alone or in combination with a surfactant for the purpose of adjusting the particle size distribution. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium stearate, and potassium stearate.

  In the case of using the emulsion polymerization method, an anionic surfactant, a cationic surfactant, a zwitterionic surfactant or a nonionic surfactant is used.

  To the toner used in the present invention, an inorganic fine powder is externally added to the toner particles as an external additive for the purpose of improving charging stability, developability, fluidity and durability. Specific examples of the external additive that is the inorganic fine powder include silica fine powder, hydrophobized silica fine powder, metal oxide, and composite metal oxide. Examples of external additives other than inorganic fine powders include various resin particles and fatty acid metal salts. These are preferably used alone or in combination.

  The fine powder of the external additive is preferably treated with a surface treatment agent for the purpose of hydrophobization and chargeability control, if necessary. Specific examples of the surface treating agent include silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having a functional group, and other organosilicon compounds. These treatment agents may be used alone or in combination.

The external additive suitably used in the present invention has a specific surface area by nitrogen adsorption measured by the BET method of 20 m ² / g or more (particularly preferably 30 to 400 m ² / g). The amount used is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner particles.

  The image forming method using the toner of the present invention is not limited as long as it is an electrophotographic image forming apparatus. More preferably, the electrostatic latent image carrier is primarily charged, a latent image is formed by exposure, the formed latent image is developed by a developing unit, and the resulting toner image is transferred onto a transfer material, and is heated and pressurized. The toner is used as an electrophotographic toner for forming a fixed image.

  Further, the toner of the present invention can be used as either a one-component developer or a two-component developer.

  Next, an image forming apparatus for carrying out the image forming method of the present invention will be described.

(1) Example of Image Forming Apparatus FIG. 5 is a schematic cross-sectional view showing a schematic configuration of a laser beam printer (hereinafter abbreviated as a printer) 1 as an example suitably showing the image forming apparatus of the present embodiment.

  Image information is input to the printer 1 from an image information providing device (not shown) such as a host computer provided outside the printer body. The printer 1 performs a series of image forming processes in which an image corresponding to the input image information is formed and recorded on a sheet-like recording material (recording medium) P according to a known electrophotographic system.

  The printer 1 includes a process cartridge 4 that holds a drum-like rotatable electrophotographic photosensitive member (hereinafter abbreviated as a photosensitive member) 2 as a latent image carrier, a primary charging mechanism 8, and a developing device 3. I have. Further, a laser scanner unit (hereinafter abbreviated as “scanner”) 5 for forming an electrostatic latent image corresponding to the image information on the outer peripheral surface of the photoreceptor 2 by an exposure processing step corresponding to the image information input from the image information providing apparatus. It has. Further, a roll-shaped rotatable transfer body 6 that performs a process of transferring an image to the recording material P, and a fixing device 7 as an image heating apparatus that performs a fixing process on the recording material P that has undergone the image transfer process by heating and pressing. It has.

  The process cartridge 4 is detachably supported with respect to the printer body. When maintenance such as repair of the photosensitive member 2 and supply of developer to the developing device 3 is necessary, the maintenance is performed by opening the cover 9 supported by the main body so as to be opened and closed and then replacing the process cartridge 4 together. Speeding up and simplification.

  The primary charging mechanism 8 is configured to charge the outer peripheral surface of the rotating photosensitive member 2 to a specified potential distribution by applying a specified bias before the exposure processing step by the scanner 5.

  The scanner 5 outputs a laser La corresponding to the image information from the image information providing apparatus. The laser La scans and exposes the charged outer peripheral surface of the photoreceptor 2 through a window 4a provided in the process cartridge body. As a result, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the photoreceptor 2.

  Next, a series of image forming processes in the printer 1 will be described. When the start button or the like (not shown) provided on the printer main body is pressed, the rotation of the photosensitive member 2 is started. The photoreceptor 2 is driven to rotate at a specified peripheral speed in the clockwise direction indicated by the arrow K1. At the same time, the outer peripheral surface of the photoreceptor 2 is charged to a specified potential distribution by the primary charging mechanism 8 to which a specified bias is applied.

  Next, the charged portion of the outer peripheral surface of the photoconductor 2 is scanned and exposed by the scanner 5 in accordance with image information from the image information providing apparatus. Thereby, an electrostatic latent image corresponding to the image information is formed on the portion of the photoreceptor 2. The electrostatic latent image is developed by the developer of the developing device 3 to be visualized as a toner image.

  On the other hand, the recording material P is fed from the paper feed cassette 11 by the paper feed roller 12 driven at a predetermined timing. The recording material P fed from the paper feed cassette 11 is fed to a transfer nip portion formed between the photosensitive member 2 and the transfer member 6 by a registration roller pair 12a at a predetermined control timing, and the transfer nip portion. Is being nipped and conveyed. In this nipping and conveying process, the toner image on the photosensitive member 2 side is sequentially transferred to the recording material P side by the transfer member 6.

  The recording material P that has been subjected to the transfer process is subjected to heat fixing processing of the toner image by the fixing device 7 and then passes through the fixing paper discharge unit 10 that is rotatably supported by the printer main body. 13 is discharged outside the apparatus. The discharged recording material P is stacked on a tray 14 attached to the upper surface of the printer main body. As described above, a series of image forming processes is completed.

(2) Fixing Device Example FIG. 6 is a schematic cross-sectional view of a fixing device 7 which is an image heating device of an external heating method as an example that suitably illustrates this embodiment.

  Reference numeral 30 denotes a fixing roller (fixing rotating body) as a rotatable heating member that heats an image on the recording material at the nip portion. Reference numeral 63 denotes a rotatable pressure roller as a pressure member. The pressing member 63 may be a fixed pad.

  The fixing roller 30 and the pressure roller 63 are arranged substantially in parallel in the vertical direction, and are pressed against each other by a pressure spring (not shown) at the end. Thus, a fixing nip portion (pressure nip portion) Nt having a predetermined width is formed between them in the recording material conveyance direction.

  The fixing roller 30 is rotationally driven by a driving means (not shown) in a clockwise direction indicated by an arrow at a predetermined peripheral speed. The pressure roller 63 rotates following the rotation of the fixing roller 30. Note that the fixing roller 30 and the pressure roller 63 may be separately rotated.

  Reference numeral 21 denotes a heating means (heating source) for heating the fixing roller 30 from the outside thereof. In this embodiment, the heating means 21 is a plate heater (hereinafter abbreviated as a heater). The heater 21 is fixedly held on the heater holder 24 and arranged in parallel on the upper side of the fixing roller 30. The holder 24 is pressed with a constant pressure by a pressurizing mechanism (not shown), and the heater 21 is adjusted so as to come into pressure contact with the upper surface of the fixing roller 30 with a predetermined pressure. The heater 21 is always in contact with the fixing roller 30 at the same position, and forms a heating nip portion Nh having a predetermined width in the rotational direction of the fixing roller 30 with the fixing roller 30.

  The rotating fixing roller 30 is heated from the outside by the heater 21 at the heating nip portion Nh, and is given a necessary and sufficient amount of heat to fix the unfixed toner image T on the recording material P at the fixing nip portion Nt. .

  As described above, after the toner image T is formed in the image forming portion, the recording material P is sent to the fixing device 7 and introduced into the fixing nip portion Nt formed by the fixing roller 30 and the pressure roller 63. It is nipped and conveyed. In the process in which the recording material P is nipped and conveyed through the fixing nip portion Nt, the recording material P is heated by the fixing roller 30 and receives the nip portion pressure so that the unfixed toner image T is thermally pressed as a permanently fixed image on the recording material P surface. It is fixed.

  Below, the measuring method concerning this invention is demonstrated.

<Electron beam microanalyzer (EPMA) measurement>
In the present invention, the abundance ratio of Al and / or Zn elements with respect to the total amount of elements detected when the surface of the fixing roller is measured by an electron beam microanalyzer (EPMA) is defined. At this time, the Al element and the Zn element are derived from the heat conductive filler. EPMA measures elements existing to a depth of several μm from the surface, and the ratio of Al and Zn to the total amount of elements corresponds to the amount of thermally conductive filler existing at a depth of several μm from the surface. Therefore, when the abundance ratio of Al or Zn is high, it indicates that more heat conductive filler exists in the surface portion. The measurement conditions are shown below.
Apparatus: Electron beam microanalyzer EPMA-1610 (manufactured by Shimadzu Corporation)
Acceleration voltage: 15 kV
Irradiation current: 20 nA
Measurement time: 500msec
Beam diameter: 10 μm

<Measurement of heat capacity per unit area of heat storage layer>
In the present invention, the heat capacity per unit area of the heat storage layer is defined. Here, the surface area of the heat storage layer refers to the area of the surface of the heat storage layer that appears when all the release layers are peeled off. Therefore, the “surface area of the test piece” also represents only the area of the surface that appears when peeling as described above. The heat capacity per unit area of the heat storage layer is obtained by the following equation.
Heat capacity per unit area of the fixing roller = volume of test piece × volume heat capacity ÷ surface area of test piece = volume heat capacity × specific heat capacity × heat storage layer 33 thickness Formula (A)

  Therefore, in order to calculate the heat capacity per unit area of the heat storage layer, it is necessary to first measure the specific heat capacity and the volume heat capacity. Specific heat capacity and volumetric heat capacity were determined as follows.

  First, a test piece having a length of 5 mm and a width of 5 mm is cut out from the heat storage layer 33 of the fixing roller 30, and the test piece is measured with a dry automatic densimeter (model number AccuPyc1330, Shimadzu Corporation) to obtain a mass density.

Next, the test piece is measured with a differential scanning calorimeter (model number DSC8240, manufactured by Rigaku Corporation) to determine the specific heat capacity. Since the volumetric heat capacity is obtained from the following equation, it is calculated from the value obtained above.
Volumetric heat capacity = mass density x specific heat capacity

  The heat capacity per unit area of the heat storage layer was calculated by substituting the specific heat capacity and the volume heat capacity thus obtained into the formula (A).

<Measurement of thermal conductivity of thermal conductive filler / heat storage layer / heat insulating elastic layer>
The thermal diffusivity is measured with a Fourier transform type temperature thermal diffusivity measuring device (model number FTC-1, ULVAC-RIKO, Inc.). When measuring a heat storage layer or a heat insulating elastic layer, measurement in the thickness direction is performed. And from the following formula | equation, the heat conductivity of the heat conductive filler and the heat conductivity of the thickness direction of a thermal storage layer or a heat insulation elastic layer are calculated | required.
Thermal conductivity = thermal diffusivity x mass density x specific heat capacity

<Method for measuring Rz on surface of image heating member>
Measurement was performed at a measurement distance of 4 mm using Surfcoder SE-3300 (manufactured by Kosaka Laboratory). The measurement locations were both end portions at a position 30 mm to 40 mm from the rubber end of the image heating member and a central portion at a position 110 mm to 120 mm from the rubber end. Measurements were made in the axial direction and the circumferential direction at each location, and the average value of the six measured values was defined as Rz.

<Measurement of micro hardness of image heating member>
The micro hardness of the image heating member can be a value measured in a peak hold mode in a 23 ° C./55% RH environment using a micro hardness meter MD-1 type (manufactured by Kobunshi Keiki Co., Ltd.). Specifically, the image heating member is placed on a metal plate, and a metal block is placed on the image heating member so that the image heating member does not roll. Press the measuring terminal accurately at the center and read the value after 5 seconds. A total of three points are measured at both ends and the center of the image heating member at a position of 30 mm or more and 40 mm or less from the rubber end of the image heating member. The average value of the measured values obtained in total of 6 points was defined as micro hardness.

<Measurement of thermally stimulated current of toner>
The thermally stimulated current (TSC) in the present invention is measured by a measurement technique that generates polarization and charge traps inside the sample by applying an electric field to the sample, and detects the current that occurs mainly due to a decrease in depolarization during the temperature rising process. The As such an apparatus, an electron trap measuring system (TS-FETT: manufactured by Rigaku Corporation) can be used.

(1) First thermal stimulation current measurement Thermal stimulation current is measured by non-contact method (2 mm) using TS-FETT.

  The toner sample for measuring the heat-stimulated current was prepared by leaving 1 g of toner in a normal temperature and humidity environment (temperature: 23 ° C., humidity: 60%) for 48 hours, and weighing about 6 mg of the toner sample. Place in a sample pan (diameter 6 mm, depth 0.5 mm), smooth the surface of the sample with a glass plate and place it in a sample holder to make a sample for measurement.

  A charging device shown in FIG. 7 is used to charge the measurement sample with a grid voltage of 1 KV and a corona voltage of 20 KV for 30 seconds. Negatively charged toner is negatively charged, and positively charged toner is positively charged.

  The TSC measuring apparatus has the configuration shown in FIG. 8. The sample holder is set in TS-FETT, and the current at the time of temperature rise is measured by heating from 25 ° C. to 100 ° C. at a rate of 1.5 ° C./min To do.

(2) Second Thermal Stimulation Current Measurement The toner sample used for the first thermal stimulation current measurement is cooled to 25 ° C. at a cooling rate of 2 ° C./min.

  A charging device shown in FIG. 7 is used to charge the measurement sample with a grid voltage of 1 KV and a corona voltage of 20 KV for 30 seconds. Negatively charged toner is negatively charged, and positively charged toner is positively charged. A sample holder is set to TS-FETT, and it heats to 25 degreeC to 120 degreeC with the temperature increase rate of 1.5 degreeC / min, and measures an electric current.

<Measurement of toner weight average particle diameter (D4)>
The weight average particle diameter (D4) of the toner is calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

  The specific measurement method is as follows.

  (1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.

  (2) About 30 ml of the electrolytic solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.

  (6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.

  (7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle diameter (D4).

<Molecular weight distribution measurement>
The molecular weight distribution and molecular weight were measured under the following measurement conditions using a GPC measuring device (HLC-8120 GPC manufactured by Tosoh Corporation) according to the operation manual of the device.

[Measurement condition]
Column (manufactured by Showa Denko KK): Shodex GPC KF-801, Shodex GPC KF-802, Shodex GPC KF-803, Shodex GPC KF-804, Shodex GPC KF-805, Shodex GPC KF-806, G 807 (diameter: 8.0mm, length: 30cm), 7 stations, temperature: 40 ° C
・ Flow rate: 0.6ml / min
・ Detector: RI
Sample concentration: 10 μl of 0.1% by mass sample
Sample preparation was performed by placing the sample to be measured in tetrahydrofuran (THF), allowing it to stand for 6 hours, and then shaking it sufficiently (until the samples were completely united), and then allowing it to stand for 1 day or longer. And what passed the sample processing filter (pore size 0.45 micrometer) was made into the sample for GPC measurement. The calibration curve used was a molecular weight calibration curve prepared using at least about 10 monodispersed polystyrene standard samples, for example, those having a molecular weight of about 10 ^{2 to} 10 ⁷ manufactured by Tosoh Corporation.

<Maximum endothermic peak temperature measurement>
The peak temperature of the maximum endothermic peak of the wax is measured according to ASTM D3418-82 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments).

  The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.

  Specifically, about 10 mg of a sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference. Measurement is performed at ° C / min. In the measurement, the temperature is once raised to 200 ° C., subsequently lowered to 30 ° C., and then the temperature is raised again. The maximum endothermic peak of the DSC curve in the temperature range of 30 to 200 ° C. in the second temperature raising process is defined as the maximum endothermic peak of the endothermic curve in the DSC measurement.

  Hereinafter, the present invention will be specifically described with reference to production examples and examples, but this does not limit the present invention in any way.

◎ Example of fixing roller manufacturing (Manufacture of heat storage layer coating liquids 1 to 4)
As a silicone rubber raw material composition, 70 parts by mass of addition-type silicone rubber (manufactured by Toray Dow Corning Silicone Co., Ltd., trade name: DY35-561A / B), and alumina as a filler (manufactured by Showa Denko Co., Ltd., trade name: Aruna Beads CB) -A50S) was blended in 30 parts by mass. This was diluted with methyl ethyl ketone so as to have a solid content concentration of 10%, and kneaded to obtain a heat storage layer coating solution 1. The liquid viscosity was 3.0 × 10 ⁻² Pa · s. Further, as shown in Table 1, the filler type was selected and the blending ratio was adjusted to obtain heat storage layer coating solutions 2 to 4. “Alumina” in the table is manufactured by Showa Denko (trade name: Arnabeads CB-A50S), “Zinc oxide” is manufactured by Sakai Chemical Industry (trade name: LPZINC-11), and “Zirconia” is manufactured by Aszac ( Product name: AZI).

(Manufacture of dispersion for release layer)
-Manufacture of release layer dispersions 1, 3 and 4 For PFA dispersion (Daikin Kogyo Co., Ltd., trade name: NEOFLON AD-2CR), alumina as filler (trade name: Aruna Beads CB-A50S) Was blended so that the content of PFA with respect to the solid content was 1.00% by mass, whereby a release layer dispersion 1 was obtained. The same operations were carried out with the content ratios being 0.05% by mass and 3.00% by mass to prepare release layer dispersions 3 and 4. Table 2 shows the main component and filler content.

-Manufacture of release layer dispersion 2 Addition type silicone rubber (Toray Dow Corning Silicone, trade name: DY35-561A / B) 99 parts by mass of alumina as filler (Showa Denko, trade name) : Arnabeads CB-A50S) was blended in an amount of 1 part by mass. This was diluted with methyl ethyl ketone so as to have a solid content concentration of 10% to obtain a release layer dispersion 2. Table 2 shows the main component and filler content.

(Method for manufacturing fixing roller 1)
[1] Manufacture of elastic layer Addition-curable liquid silicone rubber material KE1218A solution (main agent) / B solution (curing agent) manufactured by Shin-Etsu Chemical Co., Ltd. 3 parts by weight of material: acrylonitrile, softening temperature: 160 ° C. to 170 ° C.) and 1 part by weight of polyethylene glycol were added, and stirring was continued for 15 minutes to obtain silicone rubber.

  The silicone rubber obtained above was cast on a SUM metal core having an outer diameter of 8 mm, subjected to primary vulcanization at 150 ° C. for 1 hour, and then removed from the mold and taken out. Next, after secondary vulcanization at 200 ° C. for 4 hours, heat treatment was further performed at 230 ° C. for 4 hours to prepare a fixing roller precursor resistance 1-1 having an elastic layer having a thickness of 2 mm. .

[2] Production of heat storage layer The heat storage layer coating solution 1 was applied to the fixing roller precursor 1-1 using a ring coating apparatus. At this time, the conditions of the ring coating apparatus were a moving speed of 15 mm / sec and a material discharge amount of 2100 mm ³ / sec. Thereafter, the mixture was heated in a 300 ° C. hot air circulating heating furnace for 60 minutes to obtain a fixing roller precursor 1-2 having a heat storage layer having a thickness of 150 μm composed of a solid rubber layer and a filler.

[3] Production of Release Layer A PFA dispersion (manufactured by Daikin Industries, trade name: NEOFLON AD-2CR) was applied to the fixing roller precursor 1-2 using a ring coating apparatus. The conditions for the ring coating apparatus were a moving speed of 15 mm / sec and a material discharge rate of 2100 mm ³ / sec. After drying, baking was carried out at 300 ° C. for 30 minutes to form a release layer having a thickness of 50 μm composed of a solid rubber layer and a filler. Thereafter, the surface was polished with polishing paper (polishing machine: Super finisher manufactured by Matsuda Seiki, polishing paper: 3M imperial wrapping film 30 mic silicon carbide abrasive grain type), and fixing roller 1 was obtained.

  The outline of the produced roller is as shown in Table 3. The “Al / Zn abundance ratio” in the table indicates the abundance ratio of Al and / or Zn with respect to the total amount of elements detected when the fixing roller is measured by EPMA. Here, Al and Zn elements are derived from the heat conductive filler.

(Method for manufacturing fixing roller 2)
By changing the silicone rubber used for the elastic layer to addition-type silicone rubber (trade name: DY35-561A / B, manufactured by Toray Dow Corning Silicone Co., Ltd.), and adjusting the polishing after forming the release layer, Rz is 11.0 μm A fixing roller 2 was obtained in the same manner as the fixing roller 1 except that the above. The outline of the produced roller is as shown in Table 3.

(Method for manufacturing fixing roller 3)
When forming the release layer, a layer having a thickness of 60 μm is formed by spray coating, and after drying, a 50 μm layer is further formed by using a ring coating apparatus, so that the release layer has a thickness of 110 μm. A fixing roller 3 was obtained in the same manner as the fixing roller 2 except that polishing was not performed after layer formation. The outline of the produced roller is as shown in Table 3.

(Method for manufacturing fixing roller 4)
When forming a release layer, a layer having a thickness of 140 μm is formed by spray coating, and after drying, a 50 μm layer is further formed using a ring coating apparatus, so that the thickness of the release layer is 190 μm. Was manufactured in the same manner as the fixing roller 1 to obtain the fixing roller 4. The outline of the produced roller is as shown in Table 3.

(Method for Manufacturing Fixing Roller 5)
A fixing roller 5 was obtained in the same manner as the fixing roller 1 except that the thickness of the release layer was changed to 5 μm using a ring coating apparatus. The outline of the produced roller is as shown in Table 3.

(Method for Manufacturing Fixing Roller 6)
A fixing roller 6 was obtained in the same manner as the fixing roller 5 except that the release layer dispersion used in forming the release layer was changed to the release layer dispersion 2. The outline of the produced roller is as shown in Table 3.

(Method for manufacturing fixing roller 7)
The heat storage layer coating solution to be used is changed to the heat storage layer coating solution 2, and when the heat storage layer is formed, a layer having a thickness of 200 μm is formed by spray coating, and after drying, an additional 50 μm is formed using a ring coating device. A fixing roller 7 was obtained in the same manner as the fixing roller 1 except that the thickness of the heat storage layer was changed to 250 μm by forming a layer. The outline of the produced roller is as shown in Table 3.

(Method for manufacturing fixing roller 8)
The heat storage layer coating solution to be used is changed to the heat storage layer coating solution 3, and when the heat storage layer is formed, a layer having a thickness of 50 μm is formed by spray coating, and after drying, an additional 50 μm is formed using a ring coating apparatus. A fixing roller 8 was obtained in the same manner as the fixing roller 1 except that the thickness of the heat storage layer was changed to 100 μm by forming a layer. The outline of the produced roller is as shown in Table 3.

(Manufacturing method of comparative fixing roller 1)
A comparative fixing roller 1 was obtained in the same manner as the fixing roller 8 except that the heat storage layer coating solution used was changed to the heat storage layer coating solution 4. The outline of the created roller is shown in Table 3. For the comparative fixing roller 1 only, “Al · Zn existence ratio” in the table indicates the existence ratio of zirconium with respect to the total amount of elements detected by EPMA measurement. Zirconium is derived from zirconia used in the comparative fixing roller 1 instead of the heat conductive filler.

(Manufacturing method of comparative fixing roller 2)
A fixing roller is formed except that when the heat storage layer is formed, a layer having a thickness of 220 μm is formed by spray coating, and after drying, a layer having a thickness of 50 μm is further formed by using a ring coating apparatus to thereby set the thickness of the heat storage layer to 270 μm The fixing roller 2 for comparison was obtained. The outline of the produced roller is as shown in Table 3.

(Manufacturing method of comparative fixing roller 3)
A fixing roller is formed except that when the heat storage layer is formed, a layer having a thickness of 30 μm is formed by spray coating, and after drying, a layer having a thickness of 50 μm is further formed by using a ring coating apparatus so that the thickness of the heat storage layer is 80 μm. 8 was manufactured in the same manner as described above to obtain a comparative fixing roller 3. The outline of the produced roller is as shown in Table 3.

(Manufacturing method of comparative fixing roller 4)
When forming a release layer, a layer having a thickness of 170 μm is formed by spray coating, and after drying, a 50 μm layer is further formed by using a ring coating apparatus, so that the release layer has a thickness of 220 μm. Was manufactured in the same manner as the fixing roller 1 to obtain a comparative fixing roller 4. The outline of the produced roller is as shown in Table 3.

(Manufacturing method of comparative fixing roller 5)
A comparative fixing roller 5 was obtained in the same manner as the fixing roller 1 except that a 3 μm layer was formed using a ring coating apparatus when forming the release layer. The outline of the produced roller is as shown in Table 3.

(Manufacturing method of comparative fixing roller 6)
A comparative fixing roller 6 was obtained in the same manner as the fixing roller 1 except that the release layer dispersion used in forming the release layer was changed to the release layer dispersion 3. The outline of the produced roller is as shown in Table 3.

(Manufacturing method of comparative fixing roller 7)
A comparative fixing roller 7 was obtained in the same manner as the fixing roller 1 except that the release layer dispersion used in forming the release layer was changed to the release layer dispersion 4. The outline of the produced roller is as shown in Table 3.

Toner Production Example Next, a toner production method used in the examples of the present invention will be described. In addition, all the parts in the following mixing | blending are a mass part.

(Method for producing toner 1)
For 100 parts of styrene, C.I. I. 17 parts of Pigment Blue 15: 3 and 3 parts of an aluminum compound of di-tert-butylsalicylic acid [Bontron E88 (manufactured by Orient Chemical Industries)] were prepared. These were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.), and stirred at 200 rpm at 25 ° C. for 3 hours using zirconia beads (140 parts) having a radius of 1.25 mm to prepare a master batch dispersion.

On the other hand, after adding 560 parts of 0.1M-Na ₃ PO ₄ aqueous solution to 890 parts of ion-exchanged water and heating to 60 ° C., 85 parts of 1.0M-CaCl ₂ aqueous solution is gradually added to the aqueous system containing calcium phosphate compound. A medium was obtained.
・ Master batch dispersion 50 parts ・ Styrene 38 parts ・ N-butyl acrylate 20 parts ・ Low molecular weight polystyrene 1 (Mw = 3,000, Mn = 1,050) 25 parts ・ Hydrocarbon wax 10 parts (Fischer-Tropsch wax, Maximum endothermic peak = 78 ° C, Mw = 750)
Polyester resin 5 parts [terephthalic acid: isophthalic acid: propylene oxide modified bisphenol A (2 mole adduct): ethylene oxide modified bisphenol A (2 mole adduct) = 30: 30: 30: 10 polycondensate, acid value 11, Tg = 74 ° C., Mw = 11,000, Mn = 4,000]
The above material was heated to 55 ° C., and uniformly dissolved and dispersed at 4,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). In this, 9 parts of a 70% toluene solution of a polymerization initiator 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition is put into the aqueous medium, and stirred at 8,000 rpm for 15 minutes in a TK homomixer at a temperature of 60 ° C. in an N ₂ atmosphere. Granulated. Thereafter, the temperature was raised to 65 ° C. while stirring with a paddle stirring blade. When the polymerization conversion rate of the polymerizable vinyl monomer reached 90%, an aqueous 0.1 M sodium hydroxide solution was added to disperse the aqueous system. The pH of the medium was adjusted to 9. Furthermore, it heated up at 80 degreeC with the temperature increase rate of 40 degreeC / h, and was made to react for 5 hours. After completion of the polymerization reaction, the mixture was cooled, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 3 hours to dissolve the calcium phosphate salt. The toner particles were filtered off, washed with water, and dried at a temperature of 40 ° C. for 48 hours to obtain cyan toner particles 1.

  To 100 parts of the toner particles, 2.5 parts of hydrophobic silica fine powder (number average primary particle size: 7 nm) surface-treated with hexamethyldisilazane is dry-mixed for 5 minutes with a Henschel mixer (Mitsui Mining Co., Ltd.). Thus, Toner 1 of the present invention was obtained. Various physical properties of Toner 1 are shown in Table 4.

(Method for producing toner 2)
Toner 2 is the same as Toner 1 except that the amount of low molecular weight polystyrene 1 added is 10 parts, the amount of wax added is 5 parts, and the number of revolutions of the homomixer during material dissolution is changed to 5,000 rpm. Manufactured. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 3)
Toner 3 was produced in the same manner as Toner 1 except that the amount of wax added was changed to 17 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 4)
Toner 4 was produced in the same manner as toner 1 except that the amount of hydrophobic silica fine powder added was changed to 3.0 parts. Table 4 shows the physical properties of the toner.

(Method for producing toner 5)
Toner 5 was produced in the same manner as toner 1 except that the amount of low molecular weight polystyrene 1 was changed to 40 parts and the amount of wax added was changed to 17 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 6)
Toner 1 except that the wax to be added is changed to behenyl behenate (maximum endothermic peak = 72 ° C., Mw = 700), and low molecular weight polystyrene 1 is changed to low molecular weight polystyrene 2 (Mw = 2,000, Mn = 800). In the same manner, Toner 6 was produced. Table 4 shows the physical properties of the toner.

(Method for producing toner 7)
Toner 7 was produced in the same manner as Toner 1 except that the wax to be added was changed to behenyl behenate (maximum endothermic peak = 72 ° C., Mw = 700). Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 8)
Toner 8 was produced in the same manner as toner 1 except that the amount of low molecular weight polystyrene 1 added was changed to 35 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 9)
A toner 9 was produced in the same manner as the toner 1 except that the addition amount of the polyester resin was changed to 10 parts and the addition amount of the hydrophobic silica fine powder was changed to 1.0 part. Table 4 shows the physical properties of the toner.

(Method for producing toner 10)
Toner 10 was produced in the same manner as Toner 1 except that the amount of hydrophobic silica fine powder added was changed to 4.0 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 11)
Except for changing the addition amount of the polyester resin to 15 parts, the addition amount of the hydrophobic silica fine powder to 1.0 part, and the number of revolutions of the homomixer at the time of dissolving the material to 5,000 rpm, the same as the toner 1 Thus, toner 11 was produced. Table 4 shows the physical properties of the toner.

(Method for producing toner 12)
A toner 12 was produced in the same manner as the toner 1 except that the amount of the hydrophobic silica fine powder added was changed to 5.0 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 13)
Other than changing the addition amount of the polyester resin to 20 parts, the addition amount of the hydrophobic silica fine powder to 1.0 part, the temperature during material dissolution to 60 ° C., and the rotation speed of the homomixer to 5,500 rpm Produced toner 13 in the same manner as toner 1. Table 4 shows the physical properties of the toner.

(Method for producing toner 14)
Toner 14 was produced in the same manner as toner 1 except that the amount of wax added was changed to 8 parts and the amount of polyester resin added was changed to 8 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 15)
Toner 15 was produced in the same manner as toner 1, except that the amount of wax added was 15 parts, the temperature during material dissolution was changed to 50 ° C., and the rotation speed of the homomixer was changed to 3,500 rpm. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 16)
A toner 16 was produced in the same manner as the toner 1 except that the low molecular weight polystyrene 1 was not added. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 17)
The wax to be added is 8 parts of HNP-3 (paraffin wax, manufactured by Nippon Seiki, maximum endothermic peak = 66 ° C.), and the low molecular weight polystyrene 1 is 15 parts of low molecular weight polystyrene 3 (Mw = 2,500, Mn = 900). Toner 17 was produced in the same manner as toner 1 except that the amount of hydrophobic silica fine powder added was changed to 2.0 parts. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 18)
The addition amount of low molecular weight polystyrene 1 is 35 parts, the addition amount of wax is 25 parts, the addition amount of polyester resin is 3 parts, the temperature during material dissolution is 45 ° C., and the rotation speed of the homomixer is 3, Toner 18 was produced in the same manner as Toner 1 except that the number of revolutions of the homomixer during granulation was changed to 7,500 rpm at 000 rpm. Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 19)
A toner 19 was produced in the same manner as the toner 1 except that the low molecular weight polystyrene 1 to be added was changed to low molecular weight polystyrene 4 (Mw = 5,000, Mn = 1,700). Table 4 shows the physical properties of the toner.

(Manufacturing method of toner 20)
The following materials were mixed in advance, melt kneaded with a biaxial extruder, the cooled kneaded product was coarsely pulverized with a hammer mill, and the resulting finely pulverized product was classified to obtain toner particles. Inorganic fine powder was externally added to the obtained toner particles in the same manner as in Toner 1 to obtain Toner 20. Table 4 shows the physical properties of the toner.
Binder resin 100 parts [styrene-n-butyl acrylate copolymer resin (Mw = 30,000, Tg = 62 ° C.)]
・ C. I. Pigment Blue 15: 3 7 parts, aluminum compound of di-tertiary butylsalicylic acid 1.5 parts (Orient Chemical Industries, Ltd .: Bontron E88)
Low molecular weight polystyrene 1 (Mw = 3,000, Mn = 1,050) 25 parts Hydrocarbon wax 10 parts (Fischer-Tropsch wax, maximum endothermic peak = 78 ° C., Mw = 750)
Polyester resin 5 parts [terephthalic acid: isophthalic acid: propylene oxide modified bisphenol A (2 mole adduct): ethylene oxide modified bisphenol A (2 mole adduct) = 30: 30: 30: 10 polycondensate, acid value 11, Tg = 74 ° C., Mw = 11,000, Mn = 4,000]

(Method for producing comparative toner 1)
Without adding low molecular weight polystyrene 1, the added wax is SP-1035 (paraffin wax, manufactured by Nippon Seiki Co., Ltd., maximum endothermic peak = 59 ° C.) and the amount of hydrophobic silica fine powder added is 1.0 part. Comparative toner 1 was produced in the same manner as toner 1 except that the temperature at the time of material dissolution was changed to 65 ° C. and the rotation speed of the homomixer was changed to 6,000 rpm. Table 4 shows the physical properties of the toner.

(Method for producing comparative toner 2)
The addition amount of low molecular weight polystyrene 1 is 35 parts, the addition amount of wax is 30 parts, the addition amount of polyester resin is 1.5 parts, the temperature during material dissolution is 45 ° C., and the rotation speed of the homomixer is Comparative toner 2 was produced in the same manner as toner 1 except that the homomixer rotation speed during granulation was changed to 3,000 rpm and 7,500 rpm. Table 4 shows the physical properties of the toner.

(Method for producing comparative toner 3)
Except for changing the added wax to HNP-3 (paraffin wax, manufactured by Nippon Seiki, maximum endothermic peak = 66 ° C.) and the addition amount of hydrophobic silica fine powder to 6.5 parts, the same as in the toner 1 Comparative toner 3 was manufactured. Table 4 shows the physical properties of the toner.

(Method for producing comparative toner 4)
Other than changing the addition amount of the polyester resin to 30 parts, the addition amount of the hydrophobic silica fine powder to 1.0 part, the temperature during material dissolution to 60 ° C., and the rotation speed of the homomixer to 5,500 rpm Produced a comparative toner 4 in the same manner as toner 1. Table 4 shows the physical properties of the toner.

<Examples 1 to 27 and Comparative Examples 1 to 11>
For the fixing roller and the toner, evaluations (1) to (7) described later were performed. The specific evaluation method is shown below.

A modification machine of LBP-5500 (manufactured by Canon Inc.) was used as an evaluation machine, and each fixing roller shown in Table 5 was provided in the fixing device shown in FIG. Durability tests were performed on images with a printing ratio of 5% area ratio in a continuous mode up to 8,000 sheets in a low temperature and low humidity environment (15 ° C., 10% RH). A4 size CLC color copy paper (manufactured by Canon Inc., weighing 80 g / m ² ) was used as the recording material.

  For the evaluation, each toner listed in Table 5 was filled in the cartridge and mounted in the cyan station, and dummy cartridges were mounted in the other stations, and the items (1) to (5) were evaluated, and the durability test was performed. Thereafter, the items (6) and (7) were evaluated. The evaluation results are shown in Table 5.

(1) Warm-up time measurement The evaluation machine was left in a low-temperature and low-humidity environment (15 ° C., 10% RH) for 6 hours, and the time from when the power was turned on until the surface of the fixing roller reached 200 ° C. was measured.
A: Less than 25 seconds. (Good)
B: 25 seconds or more and less than 35 seconds. (No problem in practical use)
C: 35 seconds or more and less than 45 seconds. (Practical limit)
D: More than 45 seconds. (There are practical problems)

(2) Low temperature offset resistance A solid image with a toner loading of 0.60 mg / cm ² is formed in the first half of the recording material, and a white image is formed in the second half. The fixing speed is 360 mm / sec. Was modulated from 170 to 200 ° C. Fixing heating when an offset phenomenon (a phenomenon in which a part of the fixed image adheres to the surface of the fixing device and is fixed on the recording material in the next round) occurs in the latter half of the recording material when passing through the fixing device. The temperature of the surface of the part was measured to determine the temperature at which the low temperature offset phenomenon occurred and was evaluated based on the following evaluation criteria.
A: Less than 180 ° C. (Good)
B: 180 degreeC or more and less than 190 degreeC. (No problem in practical use)
C: 190 degreeC or more and less than 195 degreeC. (Practical limit)
D: 195 ° C or higher. (There are practical problems)

(3) High temperature offset resistance A halftone image of 5 cm × 5 cm area is formed with a toner loading amount of 0.25 mg / cm ² at the center of the front end of the recording material, the fixing speed is 120 mm / sec, and the fixing temperature is 200. Modulated to ~ 230 ° C. An offset phenomenon (a phenomenon in which a part of the fixed image adheres to the surface of the fixing device and is fixed on the recording material in the next round) occurs at the rear end of the recording material in the paper passing direction when passing through the fixing device. The temperature of the surface of the fixing heating part at the time was measured and set as a high temperature offset phenomenon occurrence temperature, and evaluated based on the following evaluation criteria.
A: 220 ° C. or higher (good)
B: 210 ° C or higher and lower than 220 ° C (no problem in practical use)
C: 205 ° C. or higher and lower than 210 ° C. (practical limit)
D: Less than 205 ° C. (practical problem)

(4) Low-temperature fixability A prober bond paper (Fox River, weighing 105 g / m ² ) was used as a recording material, and a halftone image with a toner loading of 0.25 mg / cm ² was formed to increase the fixing speed. Fixing is performed at 360 mm / sec with the fixing temperature modulated, and the obtained fixed image is observed with a symbol paper at 5 reciprocations at a load of about 100 g, and the image peeling is arithmetically averaged at a reduction rate (%) of reflection density. The temperature at which the temperature became 10% or less was determined as the fixing start temperature.
A: Less than 180 ° C. (Good)
B: 180 degreeC or more and less than 190 degreeC. (No problem in practical use)
C: 190 degreeC or more and less than 200 degreeC. (Practical limit)
D: 200 degreeC or more. (There are practical problems)

(5) Image Glossiness A solid image with a toner applied amount of 0.5 mg / cm ² is prepared, fixing speed is set to 360 mm / sec, fixing is performed at a fixing temperature of 200 ° C., and “PG-3D” (NEC) The glossiness of the fixed image at a measurement optical part angle of 75 ° was measured using a color industry.
A: 25 or more (good)
B: 20 or more and less than 25 (no problem in practical use)
C: 15 or more and less than 20 (practical limit)
D: Less than 15 (insufficient for glossy image)

(6) Development streak A halftone image with a toner loading of 0.30 mg / cm ² was output, and the image and the developing roller were visually observed and evaluated.
A: A vertical stripe that appears as a development stripe is not seen on the developing roller or the halftone image. There is no practical problem at all.
B: Although there are 1 to 3 fine streaks in the circumferential direction on the developing roller, no vertical streaks are seen on the halftone image. There is no problem in practical use.
C: There are several fine streaks in the circumferential direction on the developing roller, and several fine streaks can be seen on the halftone image. However, it is a level that can be erased by image processing, and there is almost no problem in practical use.
D: Many streaks are observed on the developing roller and the halftone image, and cannot be erased even by image processing. A practically problematic level.

(7) fog The fog density (%) is calculated from the difference between the whiteness of the white portion of the printout image and the whiteness of the transfer paper measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.). The fog was evaluated. An amberlite filter was used as the filter.
A: Less than 1.0% (good)
B: 1.0% or more and less than 2.0% (no problem in practical use)
C: 2.0% or more and less than 3.0% (practical limit)
D: 3.0% or more (practical problem)

3 is a diagram illustrating a current measured at the time of first temperature increase by the thermally stimulated current measuring device for toner 1 of the present invention. 4 is a diagram illustrating a current measured at the second temperature increase by the thermally stimulated current measuring apparatus for toner 1 of the present invention. It is a block diagram of the image heating member in this invention. It is a block diagram of the ring coating apparatus preferably used by this invention. 1 is a configuration diagram of an image forming apparatus that can be used in the present invention. 1 is a configuration diagram of a fixing device according to the present invention. It is the schematic of the charging device used by this invention. It is the schematic of the thermally stimulated current (TSC) measuring apparatus used by this invention.

Claims (11)

A charging step of charging the electrostatic latent image carrier with charging means, an exposure step of exposing the charged electrostatic latent image carrier to form an electrostatic latent image, and developing the electrostatic latent image with toner Development process for forming a toner image, transfer process for transferring the toner image to a recording material with or without an intermediate transfer member, and an image heating member capable of rotating the recording material carrying the toner image with a pressure member In an image forming method having a fixing step of fixing by heating and pressing by passing through a nip formed by
The image heating member is
(I) A roller having a release layer having a thickness of 5 to 200 μm as the outermost layer, a heat storage layer as a lower layer thereof, and further having an elastic layer as a lower layer thereof, per unit area of the heat storage layer The heat capacity is 100 to 600 J / (m ² · K),
(Ii) heated from the outermost surface by an external heating means,
(Iii) containing a heat conductive filler having a thermal conductivity of 5.0 W / (m · K) or more, the heat conductive filler being an Al and / or Zn compound;
(Iv) When the surface is measured by EPMA (electron beam microanalyzer), the abundance ratio of Al and / or Zn elements derived from the heat conductive filler is 0.10 to 0.10 to the total amount of elements detected by EPMA. 3.00% by mass,
The toner is
(I) having toner particles containing at least a binder resin, a colorant, and wax, and inorganic fine powder;
(Ii) The current value of the thermally stimulated current measured at the first temperature rise by the thermally stimulated current measuring device has a main peak (P1) at 60 to 100 ° C., and the absolute value of the current indicating P1 is 0 1 × 10 ^{−14 to} 1000.0 × 10 ⁻¹⁴ A, and the current value of the thermally stimulated current measured at the second temperature rise has a peak (P2) at least from 60 to 110 ° C. A temperature T1 (° C.) indicating P2 and a temperature T2 (° C.) indicating P2 are:
−15 ≦ T2−T1 ≦ 15
Satisfy the relationship
An image forming method.   2. The image forming method according to claim 1, wherein the surface roughness Rz of the image heating member is 1.0 to 10.0 μm.   3. The image forming method according to claim 1, wherein the release layer of the image heating member is a solid rubber layer mainly composed of fluoro rubber.   4. The image forming method according to claim 1, wherein the heat conductive filler is contained in an amount of 10 to 50% by mass in the heat storage layer of the image heating member.   The image forming method according to claim 1, wherein the image heating member has a micro hardness of 30 to 68 °.   The image forming method according to claim 1, wherein the elastic layer has a thermal conductivity of 0.15 W / (m · K) or less. 7. The image forming method according to claim 1, wherein the absolute value of the current indicating P1 is 4.0 × 10 ^{−14 to} 60.0 × 10 ⁻¹⁴ A. The relationship between T1 and T2 is
−10 ≦ T2−T1 ≦ 10
The image forming method according to claim 1, wherein:   In the thermal stimulation current measurement, the current value of the thermal stimulation current measured at the second temperature increase has two peaks (P2, P3) in the range of at least 60 to 110 ° C., and the peak on the high temperature side (P3 The image forming method according to any one of claims 1 to 8, wherein the temperature is 85 ° C or higher. The image forming method according to claim 9, wherein an absolute value of a current indicating P3 is 1.0 × 10 ^{−14 to} 50.0 × 10 ⁻¹⁴ A. 11. The image forming method according to claim 9, wherein the absolute value of the current indicating P2 is 1.0 × 10 ^{−14 to} 50.0 × 10 ⁻¹⁴ A.

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