JP2011008109A - Rotating body for fixing device, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating body for a fixing device in which wear of its surface is suppressed.SOLUTION: The rotating body for the fixing device has base material, and a surface layer provided on an outer peripheral surface of the base material, wherein the surface layer contains a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and inorganic particles set so that a value of a shape factor SF1 and a value of a shape factor SF2 may satisfy at least one of following conditions (1) and (2). The condition (1): 100<SF1<300 and 140<SF2<250. The condition (2): 170<SF1<300 and 100<SF2<250.

Description

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

  As a fixing member (rotating body for fixing device) used in a fixing device provided in an image forming apparatus, for example, a core metal made of aluminum, iron, stainless steel, etc., an elastic layer such as silicone rubber, or fluoro rubber And a structure in which a surface release layer such as fluororesin is formed.

  Examples of the fluororesin used as the surface release layer include an example for preventing cracking (JP-A-9-11362), PFA (tetrafluoroethylene-perfluoroalkyl) for imparting functions such as durability improvement, and the like. Vinyl ether copolymer), PTFE (polytetrafluoroethylene), or an example in which an inorganic filler (conductive oxide or graphite) is added to a PTFE / PFA mixed fluororesin (Japanese Patent Laid-Open Nos. 2001-125404 and 6) JP-A-348165, JP-A-9-237007), an example in which an organic substance is added to a PFA resin (JP-A-10-39667), and the like are disclosed. Further, for example, a fixing rotating body (Japanese Patent Laid-Open No. 2003-149976) including a fluororesin and inorganic particles has been proposed.

JP-A-9-11362 JP 2001-125404 A JP-A-6-348165 JP-A-9-237007 JP-A-10-39667 JP2003-149976

  An object of the present invention is to provide a rotating body for a fixing device in which surface wear is suppressed as compared with a case where inorganic particles whose shape factor SF1 and shape factor SF2 fall within the above range are not included in the surface layer. That is.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1
A substrate;
Provided on the outer peripheral surface of the base material, the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, the value of the shape factor SF1 and the value of the shape factor SF2 satisfy at least one of the following conditions (1) and (2) A surface layer comprising inorganic particles to fill,
It is a rotating body for fixing devices.
Condition (1): 100 <SF1 <300 and 140 <SF2 <250
Condition (2): 170 <SF1 <300 and 100 <SF2 <250

The invention according to claim 2
The value of the shape factor SF1 and the value of the shape factor SF2 of the inorganic particles is the fixing device rotating body according to claim 1, wherein the following condition (3) is satisfied.
Condition (3): 190 <SF1 <280 and 160 <SF2 <230

The invention according to claim 3
A fixing device comprising the fixing device rotating body according to claim 1.

The invention according to claim 4
An image carrier, a latent image forming unit that forms a latent image on the surface of the image carrier, a developing unit that develops the latent image with toner to form a toner image, and transfers the toner image to a recording medium An image forming apparatus comprising: a transfer unit; and a fixing unit having the fixing device according to claim 3 for fixing the toner image on a recording medium.

  According to the first aspect of the present invention, surface wear is suppressed as compared to the case where inorganic particles whose shape factor SF1 and shape factor SF2 fall within the above ranges are not included in the surface layer.

  According to the invention which concerns on Claim 2, surface abrasion is suppressed more compared with the case where the surface layer does not contain the inorganic particles whose values of the shape factor SF1 and the shape factor SF2 fall within the above range.

  According to the invention of claim 3, the rotation for the fixing device is compared with the case where the inorganic particles whose shape factor SF1 and shape factor SF2 fall within the above range are not included in the surface layer of the fixing device rotor. Deterioration of fixability due to body surface wear is suppressed.

  According to the invention of claim 4, the rotation for the fixing device is compared with the case where the inorganic particles whose values of the shape factor SF <b> 1 and the shape factor SF <b> 2 fall within the above range are not included in the surface layer of the fixing device rotating body. Deterioration of fixability due to body surface wear is suppressed.

FIG. 2 is a cross-sectional view illustrating an example of a fixing device rotating body according to the exemplary embodiment. 1 is a schematic configuration diagram illustrating an example of a fixing device according to an exemplary embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is provided to the member which has the same effect | action and function through all the drawings, and the overlapping description may be abbreviate | omitted.

[Rotating body for fixing device]
FIG. 1 is a cross-sectional view showing a specific example of the fixing device rotor of the present invention. A fixing device rotator 10 shown in FIG. 1 is configured, for example, by sequentially forming an elastic layer 3 and a surface layer 2 on a cylindrical substrate 1. The fixing device rotator 10 may have a configuration without the elastic layer 3.

As shown in FIG. 1, when the fixing device rotating body 10 is formed in a roll shape, examples of the material of the base material 1 include metals, and specific examples include aluminum, iron, stainless steel, and the like. These heat-resistant metal materials can be mentioned.
Further, the fixing device rotating body 10 is not limited to a roll shape, and may be a belt shape, for example. When the fixing device rotator 10 is belt-shaped, examples of the substrate 1 include a heat-resistant resin, and specific examples include polyimide, polyamideimide, and polyimidabendazole.

  Examples of the material for forming the elastic layer 3 include silicone rubber and fluorine rubber. Specific examples of the silicone rubber include HTV (high temperature vulcanization type) silicone rubber, LTV (low temperature vulcanization type) silicone rubber, and RTV (room temperature vulcanization type) silicone rubber. Examples of the fluororubber include VDF fluororubber and VDF-HFP fluororubber (binary or ternary).

  As thickness of the elastic layer 3, 100 micrometers or more and 3000 micrometers or less are mentioned, for example, The range of 200 micrometers or more and 2000 micrometers or less is mentioned preferably.

  The surface layer 2 includes a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter sometimes referred to as “PFA”) and inorganic particles.

  The surface layer 2 may include other fluororesins such as polytetrafluoroethylene (hereinafter sometimes referred to as “PTFE”) in addition to PFA. When the fluororesin constituting the surface layer 2 is a mixture containing PFA and PTFE, the content of PFA in the fluororesin is preferably 50% by mass or more and 100% by mass or less, and 60% by mass or more and 90% by mass or less. More preferably, it is 70 mass% or more and 80 mass% or less.

The shape factor SF1 and the shape factor SF2 of the inorganic particles satisfy at least one of the following condition (1) and the following condition (2).
Condition (1): 100 <SF1 <300 and 140 <SF2 <250
Condition (2): 170 <SF1 <300 and 100 <SF2 <250

Further, the shape factor SF1 and the shape factor SF2 of the inorganic particles preferably satisfy the following condition (3), and more preferably satisfy the following condition (4).
Condition (3): 190 <SF1 <280 and 160 <SF2 <230
Condition (4): 210 <SF1 <260 and 180 <SF2 <220

The shape factor SF1 and shape factor SF2 of the inorganic particles are determined by observing the inorganic particles at a magnification of 400 times using an optical microscope, randomly selecting 100 particles, and analyzing the image information by Nicole Image Analysis. It is obtained by introducing it into an apparatus (LUZEXFT) and performing analysis. In addition, the value of the shape factor SF1 and the value of the shape factor SF2 are represented by the following formula (5) and the following formula (6), and an average value of the values obtained in the 100 inorganic particles is adopted.
Formula (5): SF1 = (π / 4) × (L ² / A) × 100
Formula (6): SF2 = (1 / 4π) × (I ² / A) × 100
Here, L represents the maximum length of the inorganic particles on the image, I represents the peripheral length of the inorganic particles on the image, and A represents the projected area of the inorganic particles.

Specific examples of the inorganic particles include silicon carbide (SiC), silica, boron nitride (BN), alumina (Al ₂ O ₃ ), titanium nitride (TiN), titanium oxide, potassium titanate, and titanic acid. Examples include barium, barium sulfate, magnesium oxide, antimony oxide, calcium carbonate, carbon black, graphite, mica, and conductive mica (volume resistivity at 20 ° C. is 1 × 10 ⁻⁶ Ωcm or less). It may be used as a mixture of two or more. Moreover, as an inorganic particle, from a viewpoint that it is easy to make the value of shape factor SF1 and the value of shape factor SF2 into the said range, among these materials, any one or more types of silicon carbide, alumina, and barium sulfate are included. It is preferable to contain.

As a volume average particle diameter of an inorganic particle, the range of 1.0 micrometer or more and 20 micrometers or less is mentioned, for example, The range of 1.0 micrometer or more and 10 micrometers or less is mentioned preferably.
As content of the inorganic particle contained in the surface layer 2, 1.0 mass part or more and 10.0 mass parts or less are mentioned with respect to 100 mass parts of fluororesins contained in the surface layer 2, for example. 5 mass parts or more and 7.5 mass parts or less are mentioned preferably.

  As thickness of the surface layer 2, the range of 10.0 micrometers or more and 50.0 micrometers or less is mentioned, for example, The range of 20 micrometers or more and 30 micrometers or less is mentioned preferably.

  As a method of manufacturing the fixing device rotating body, when the fixing device rotating body has a roll shape as shown in FIG. 1, for example, first, a primer (adhesive layer) is applied on the outer peripheral surface of the substrate 1, and then A fluororesin tube to which inorganic particles are added is placed on the inner peripheral surface of a mold sleeve having a diameter larger than that of the base material 1, and after inserting the base material into the tube, a liquid is formed in the gap between the primer and the tube. Examples thereof include a method of injecting and molding a material for forming the elastic layer 3 such as silicone rubber. In addition to the manufacturing method described above, the rotating body for the fixing device includes a fluororesin dispersion containing inorganic particles on the surface (outer peripheral surface) of the elastic layer (elastic layer 3) coated with the primer (adhesive layer). Examples include a method of coating and baking the liquid. Furthermore, even in the case where the fixing device rotating body is a tubular belt, a method of applying the above-described method onto a resin or metal substrate can be used.

  The fixing device rotator of the present embodiment has a configuration including a surface layer containing inorganic particles and PFA having values of the shape factor SF1 and the shape factor SF2 within the above range. Surface wear is suppressed, resulting in improved durability. The reason is not clear, but is presumed as follows. Specifically, by including in the PFA inorganic particles whose shape factor SF1 and shape factor SF2 are in the above range, the area where the inorganic particles and the PFA are in contact with each other is large. It is presumed that the action of becoming difficult to detach becomes larger and the wear of the surface layer 2 is suppressed. In addition, if the value of the shape factor SF1 and the value of the shape factor SF2 of the inorganic particles are in the above ranges, the occurrence of white spots and uneven gloss due to surface irregularities is suppressed, and the deterioration of image quality is suppressed. Guessed.

[Fixing device]
The fixing device of the present embodiment is not particularly limited as long as it includes at least one fixing device rotating body, and various other known members may be combined as other members. Hereinafter, a specific example of the fixing device of this embodiment will be described with reference to FIG.

  The fixing device shown in FIG. 2 includes a heat fixing roll 11 and endless belts 15 that are held with tension applied by rolls 23 and 24 and a pressure roll 25. This uses a fixing device rotating body.

  The heat fixing roll 11 is provided with a halogen lamp having an output of 850 W, for example, as a heat source.

  The pressure roll 25 is pressurized toward the center of the heat fixing roll 11 by, for example, a compression coil spring 26. Examples of the endless belt 15 include those formed of a polyimide film or the like. Examples of the rolls 23 and 24 include those formed of stainless steel or the like. A pressure assist pad 30 is disposed between the pressure roll 25 and the roll 24. The pressure assist pad 30 is formed by laminating a base plate 31, an elastic bag 41 in which a heat-resistant liquid 40 is vacuum-sealed, and a release layer 33. The base plate 31 is made of stainless steel, for example, and supports an elastic bag 41 in which a heat-resistant liquid 40 is vacuum-sealed. The heat-resistant liquid 40 is made of, for example, dimethyl silicone oil having a viscosity of 300 cs (trade name “KF-96” manufactured by Shin-Etsu Chemical Co., Ltd.), etc. It is vacuum-sealed in an elastic bag 41 which is a thin film bag. Furthermore, as the release layer 33, for example, “FGF-400-4” (trade name) manufactured by Chuko Kasei Co., Ltd., which is a glass fiber sheet impregnated with polytetrafluoroethylene, is used.

  When the fixing device shown in FIG. 2 is used, first, an image of the toner 8 is transferred onto the recording medium 7 by a transfer device (not shown) from the right direction in the drawing, and the contact between the heat fixing roll 11 and the endless belt 15 is performed. The recording medium 7 is transported toward the part. The recording medium 7 is conveyed to the side where the pressure assist pad 30 is disposed in the contact portion. Then, the image of the toner 8 is fixed on the recording medium 7 by the pressure acting on the contact portion and the heat applied through the heat fixing roll 11 by the halogen lamp.

  In the present embodiment, the fixing device rotating body in the above embodiment is used as the heat fixing roll 11. However, the fixing device rotating body in the above embodiment is not limited thereto, and for example, the fixing device rotating body in the above embodiment is used as the endless belt 15. May be.

[Image forming apparatus]
Next, an image forming apparatus using the fixing device of the embodiment will be described.
The image forming apparatus 101 shown in FIG. 3 forms a latent electrostatic image by exposing the surface of the photosensitive member 79 to the photosensitive member 79 (electrostatic latent image holding member), a charging roll 83 for charging the surface of the photosensitive member 79. A laser generator 78 (electrostatic latent image forming means), a developing device 85 (developing means) that develops the latent image formed on the surface of the photoreceptor 79 using a developer, and forms a toner image; An intermediate transfer belt 86 (intermediate transfer body) to which the toner image formed by the device 85 is transferred from the photoreceptor 79, and a primary transfer roll 80 (first transfer means) for transferring the toner image to the intermediate transfer belt 86. A photosensitive member cleaning member 84 that removes toner, dust, and the like adhering to the photosensitive member 79; a secondary transfer roll 75 (second transfer means) that transfers the toner image on the intermediate transfer belt 86 to a recording medium; Fixing device 72 for fixing a toner image on a medium It is configured to include a fixing means), a. The primary transfer roll 80 may be disposed immediately above the photoreceptor 79 as shown in FIG. 3 or may be disposed at a position shifted from directly above the photoreceptor 79.

Further, the configuration of the image forming apparatus 101 shown in FIG. 3 will be described in detail.
In the image forming apparatus 101, a primary transfer roll 80 and a photosensitive member cleaning member 84 are arranged around the photosensitive member 79 counterclockwise via a charging roll 83, a developing device 85, and an intermediate transfer belt 86. These one set of members form a developing unit corresponding to one color. Each developing unit is provided with a toner cartridge 71 for replenishing the developer in the developing unit 85, and a charging roll 83 (rotating direction of the photosensitive member 79) is provided with respect to the photosensitive member 79 of each developing unit. A laser generator 78 that irradiates the surface of the photoreceptor 79 downstream and upstream of the developing device 85 with laser light corresponding to image information is provided.

  Four developing units corresponding to four colors (for example, cyan, magenta, yellow, and black) are arranged in series in the horizontal direction in the image forming apparatus 101, and the photosensitive member 79 of the four developing units and the primary are arranged. An intermediate transfer belt 86 is provided so as to pass through a transfer region with the transfer roll 80. The intermediate transfer belt 86 is wound on the inner surface side in a tensioned state by a support roll 73, a support roll 74, and a drive roll 81 provided in the following order in the counterclockwise direction. Forming. The four primary transfer rolls 80 are located downstream of the support roll 73 (in the rotational direction of the intermediate transfer belt 86) and upstream of the support roll 74. A transfer cleaning member 82 for cleaning the outer peripheral surface of the intermediate transfer belt 86 is provided on the opposite side of the drive roll 81 via the intermediate transfer belt 86 so as to be in pressure contact with the drive roll 81.

  The toner formed on the outer peripheral surface of the intermediate transfer belt 86 on the surface of the recording paper conveyed from the paper supply unit 77 via the paper path 76 to the opposite side of the support roll 73 via the intermediate transfer belt 86. A secondary transfer roll 75 for transferring an image is provided so as to contact the support roll 73.

  In addition, a paper supply unit 77 that accommodates a recording medium is provided at the bottom of the image forming apparatus 101, and a support roll 73 and a secondary transfer roll that constitute a secondary transfer unit from the paper supply unit 77 via a paper path 76. The recording medium is supplied so as to pass through the contact portion with 75. The recording medium that has passed through the contact portion is further transported by a transport means (not shown) so as to pass through the contact portion of the fixing device 72 and is finally discharged out of the image forming apparatus 101.

  Next, an image forming method using the image forming apparatus 101 shown in FIG. 3 will be described. The toner image is formed for each developing unit. After charging the surface of the photoreceptor 79 rotating counterclockwise by the charging roll 83, the toner image is latently formed on the surface of the photoreceptor 79 charged by the laser generator 78 (exposure device). An image (electrostatic latent image) is formed, and then the latent image is developed with a developer supplied from a developing device 85 to form a toner image, and a contact portion between the primary transfer roll 80 and the photoreceptor 79 is formed. Is transferred to the outer peripheral surface of the intermediate transfer belt 86 rotating in the direction of arrow C. The photosensitive member 79 after the toner image is transferred is cleaned by the photosensitive member cleaning member 84 for toner, dust, etc. attached to the surface of the photosensitive member 79 in preparation for the next toner image formation.

  The toner images developed for each color development unit are sequentially superimposed on the outer peripheral surface of the intermediate transfer belt 86 so as to correspond to the image information, and are conveyed to the secondary transfer unit by the secondary transfer roll 75. The image is transferred from the paper supply unit 77 to the surface of the recording paper conveyed via the paper path 76. The recording paper on which the toner image has been transferred is further fixed by being heated by pressure when passing through the contact portion of the fixing device 72. After an image is formed on the surface of the recording medium, the recording paper is discharged out of the image forming device. Is done.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited only to the Example shown below.
In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

<Example 1>
PFA resin (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, copolymerization ratio 5:95, manufactured by Mitsui DuPont Fluoro Chemical Co., Ltd., trade name: 945HP-Plus) as fluororesin, and precipitated sulfuric acid as inorganic particles 2 parts by weight of barium (manufactured by Sakai Chemical Co., Ltd., trade names: BMH60, SF-1: 172, SF-2: 143) was dispersed in advance while being melted to prepare mixed pellets. Next, the mixed pellet was extruded at a temperature of 380 ° C. to prepare a tube having a thickness of 25 μm.
Next, the above-described tube is set on the inner surface of an aluminum base material having an outer diameter of 60 mm, on which a primer (made by Toray Dow Corning Silicone Co., Ltd., trade name: DY39-051) is applied on the surface (outer peripheral surface) A cylindrical mold sleeve was placed, liquid silicone rubber (manufactured by Toray Dow Corning Silicone Co., Ltd.) was injected between the primer and the tube, and then vulcanized to prepare a fixing roll.

<Example 2>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to precipitated barium sulfate (manufactured by Sakai Chemical Co., Ltd .: BMH SF-1: 193, SF-2: 162).

<Example 3>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to precipitated barium sulfate (manufactured by Sakai Chemical Industry Co., Ltd .: BA SF-1: 215, SF-2: 181).

<Example 4>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (manufactured by Showa Denko KK: A-42-2 SF-1: 258, SF-2: 216).

<Example 5>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (manufactured by Showa Denko KK: AS50 SF-1: 277, SF-2: 228).

<Example 6>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to silicon carbide (manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: GC # 3000 SF-1: 298, SF-2: 248).

<Example 7>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (manufactured by Showa Denko KK: WA # 4000 SF-1: 125, SF-2: 245).

<Example 8>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (Kinseimatic Corp .: YFA02025 SF-1: 295, SF-2: 139).

<Example 9>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (manufactured by Showa Denko KK: WA # 8000 SF-1: 173, SF-2: 131).

<Example 10>
Instead of 100 parts by weight of PFA resin, 75 parts by weight of PFA resin and 25 parts by weight of PTFE (polytetrafluoroethylene, manufactured by Augmond, trade name: MFA) were used in the same manner as in Example 1 to obtain a fixing roll. Prepared.

<Comparative Example 1>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (manufactured by Showa Denko KK: CB-A05S SF-1: 167, SF-2: 138).

<Comparative Example 2>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to plate-like barium sulfate (manufactured by Sakai Chemical Co., Ltd .: A SF-1: 310, SF-2: 259).

<Comparative Example 3>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (manufactured by Showa Denko KK: WA # 4000 SF-1: 151, SF-2: 255).

<Comparative example 4>
A fixing roll was prepared in the same manner as in Example 1 except that the inorganic particles were changed to aluminum oxide (Kinseimatic Co., Ltd .: YFA02050 SF-1: 305, SF-2: 129).

<Comparative Example 5>
A fixing roll was prepared in the same manner as in Example 1 except that 100 parts by mass of PTFE was used instead of 100 parts by mass of the PFA resin.

<Evaluation of wear amount and gloss unevenness>
The fixing device provided with the fixing rolls obtained in the examples and comparative examples was incorporated into an image forming apparatus (manufactured by Fuji Xerox Co., Ltd .: Color Printer Docu Center Color 1100), and a running test was conducted by continuously feeding 10,000 sheets. The amount of wear on the fixing roll and the gloss unevenness in the formed image were evaluated.

  The amount of wear was evaluated by measuring the film thickness of the surface layer of the fixing roll with a laser interferometer before and after continuously passing 10,000 sheets, and determining the difference in film thickness before and after passing 10,000 sheets. The results are shown in Table 1 below.

The uneven gloss was evaluated by visually observing the uneven gloss of the image formed on the 100,000th sheet. The results are shown in Table 1 below.
(Evaluation criteria for uneven brightness)
A: Gloss unevenness was hardly observed B: Gloss unevenness was slightly observed, but was a level acceptable for practical use C: Gloss unevenness was significantly observed and was a level exceeding the practically acceptable range

  As can be seen from Table 1, in the example, compared to the comparative example, it can be seen that the wear on the surface of the fixing roll is suppressed, and uneven gloss of the fixed image is also suppressed.

1 Base material (base material)
2 Surface layer 3 Elastic layer 7 Recording medium 11 Heat fixing roll 25 Pressure roll 72 Fixing device 75 Secondary transfer roll 78 Laser generating device 79 Photoconductor 80 Primary transfer roll 85 Developer 86 Intermediate transfer belt 101 Image forming apparatus

Claims (4)

A substrate;
Provided on the outer peripheral surface of the base material, the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, the value of the shape factor SF1 and the value of the shape factor SF2 satisfy at least one of the following conditions (1) and (2) A surface layer comprising inorganic particles to fill,
A rotating body for a fixing device.
Condition (1): 100 <SF1 <300 and 140 <SF2 <250
Condition (2): 170 <SF1 <300 and 100 <SF2 <250 The rotating body for a fixing device according to claim 1, wherein a value of the shape factor SF <b> 1 and a value of the shape factor SF <b> 2 of the inorganic particles satisfy the following condition (3).
Condition (3): 190 <SF1 <280 and 160 <SF2 <230   A fixing device comprising the fixing device rotating body according to claim 1.   An image carrier, a latent image forming unit that forms a latent image on the surface of the image carrier, a developing unit that develops the latent image with toner to form a toner image, and transfers the toner image to a recording medium An image forming apparatus comprising: a transfer unit; and a fixing unit having the fixing device according to claim 3 for fixing the toner image on a recording medium.

Images