JPH063992A - Fixing method - Google Patents

Abstract

(57) [Summary] [Structure] In a method of fixing a toner image formed by a capsule toner by a heat roller type fixing device, a conductive elastomer layer having a uniform thickness provided on the heat roller is energized to generate. A fixing method characterized in that the toner is heated and fixed at a temperature of 130 ° C. or lower by applying heat. [Effect] According to the fixing method of the present invention, since fixing is performed at a fixing temperature of 130 ° C. or less, the fixing device is simplified and downsized.
The price can be reduced. Further, a member having high heat resistance as in the past is not necessary for the fixing device and its surroundings, and an inexpensive material can be used, resulting in a low cost printing device. Further, since the linear pressure can be lowered, curling of the paper is less likely to occur, and clogging of the paper is less likely to occur, resulting in various effects such as maintenance saving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing method for capsule toner used in plain paper copying machines, laser printers, plain paper facsimiles and the like.

[0002]

2. Description of the Related Art Conventionally, when forming an image in a copying machine, a laser beam printer or the like, the Carlson method is generally used (US Pat. Nos. 2,221,776, 2,297,691 and 2,357, 80
No. 9, Electrophotography: p22-p41, RM Shaffert 1
965, The Focal Press). In a conventional image forming method, an electrostatic latent image formed by an optical means is first developed in a developing process, then transferred to a recording medium such as recording paper in a transferring process, and generally subjected to heat and pressure in a fixing process. The image is fixed and formed. Since the photoconductor is used repeatedly, a cleaning device is installed to clean the residual toner after transfer as the photoconductor rotates.

However, in such a conventional image forming method, energy consumption in the fixing step is different from that in the step of forming the electrostatic latent image, transferring it to the recording medium, and fixing it in the fixing step. It is very large as compared with that of each step, and the fixing device requires a very high temperature and a large pressure. On the other hand, since the photoconductor and the developing device need to be kept at room temperature, it is necessary to keep a considerable distance between the fixing device and the photoconductor and the developing device.
Therefore, it has been a cause of increasing the size of the device. Although it was necessary to forcibly remove the generated heat, the sound generated by the forced heat dissipation device is a noise that cannot be ignored in the office.

In general, the fixing step exists independently and is performed at 200 ° C.
Since the image is fixed at a high temperature in the front and rear, expensive heat-resistant resin, heat-resistant rubber, or other heat-resistant member is required around the fixing device. Further, since the fixing is performed at a high temperature, problems such as curling and jamming of the paper are likely to occur, and not only a problem occurs,
If the fixing temperature is high, it takes time to reach the set temperature, and quick printing cannot be performed. Therefore, it is not suitable for a system that requires quick printing such as a facsimile.

As a measure for solving these problems, a cold press system is known as a device for performing low temperature fixing at 100 ° C. or lower. However, in this case, although the fixing temperature is low, the linear pressure normally becomes a high linear pressure of 4 Kg / cm or more, which not only makes the apparatus heavy, but also causes problems such as image gloss, paper deformation, and insufficient fixing strength. It is also known that a surface heating element is used as a heat source of a heat roller of a heat fixing device instead of a conventionally used quartz heater, nichrome wire, etc., and quick printing and energy-saving fixing are attempted (Japanese Patent Laid-Open Publication No. Sho. 58-196562, JP-A-1-150183, JP-A 1-26.
(See Japanese Patent No. 0475). However, since the fixing temperature is set at a high temperature close to 200 ° C., the heating element is used by putting it in the cylinder because it is necessary to avoid temperature unevenness, and the heating rate is slow and the energy efficiency is poor.

As a method of improving the current-carrying effect as a countermeasure against such a problem, slits are formed on the heating layer spirally, or when the toner releasability at high temperature is insufficient, the outer circumference of the heating roller is expensive. It was necessary to provide a heat-resistant protective layer made of a different imide resin, fluorine resin, or the like. Therefore, there are problems that the device becomes complicated and the device becomes expensive.

Further, regarding the relationship between the radius of the elastic roller and the nip width in the conventional fixing device, generally, the radius of the roller is 1.
It is about 5 mm to 50 mm, and its nip width is 3 mm.
To about 10 mm at most. Therefore, the ratio of the nip width to the radius of the elastic roller is usually 0.05 to at most 0.
Up to 20, an expensive elastic body having a very small permanent compression strain at 180 ° C to 200 ° C is used. For these reasons, toner fixing usually requires a heat roller surface temperature of 20.
This is because the toner is melted and adhered to the recording paper or the like at a temperature close to 0 ° C. and by applying a high linear pressure. That is,
In order to fuse the toner to the recording paper with a high linear pressure while melting the toner by the heat of the heat roller, it is preferable to increase the nip width in order to lengthen the heat conduction time from the heat roller to the toner. At the same time, it is indispensable to increase the linear pressure in order to press the toner softened by heat between the pulp fibers on the paper surface to increase the adhesive strength between the toner and the paper.

However, since the heat roller surface temperature has conventionally been required to be as high as 200 ° C., a heat resistant elastic body having a small permanent compression strain at a high temperature is selected and used from among various heat resistant elastic bodies. However, as described above, when a large plastic deformation is applied at high temperature and high linear pressure, permanent compression strain becomes large, the linear pressure fluctuates, and not only the fixing failure occurs but also the drive system. In reality, there is a risk that the load will increase and cause a breakdown. From these viewpoints as well, a new small fixing device and a toner adapted to it have been required. In order to meet such expectations, the effectiveness of using capsule toner as a toner is being evaluated. The present invention solves the problems as described above, and provides a fixing method using a capsule toner with high reliability and low energy consumption.

[0009]

The gist of the present invention is (1)
In a method of fixing a toner image formed of a capsule toner with a heat roller type fixing device, a conductive elastomer layer having a uniform thickness provided on the heat roller is energized, and heat fixing is performed at 130 ° C. or less by heat generated. (2) The fixing method according to (1), wherein the specific resistance value of the conductive elastomer is 100 Ω · cm or less and the maximum heat generation temperature is 150 ° C. or less. The fixing method according to (1), wherein the nip width between the pair of rollers in the apparatus is 0.2 or more of the radius of the elastic roller, and (4) the rubber hardness of at least one roller is JIS A scale A The fixing method according to (1) above, which is 90 degrees or less.

The toner used in the present invention is a toner obtained by encapsulating the toner by functionally separating storage stability, fixability and offset resistance, and is not particularly limited, but the shell has storage stability. And a chargeability, and a core toner having a coloring material, a fixing property, and an anti-offset property is preferably used (for example, JP-A-58-1766).
42, JP-A-58-176643, JP-A-61-56352, JP-A-63-128357, JP-A-61-128358, JP-A-01-
267660, JP-A-02-51175).

Such a capsule toner can usually be easily obtained by the following manufacturing method. (1) A spray dry method (spray drying method) in which a core substance is dispersed in a non-polymer aqueous solution or a polymer emulsion and then the dispersion is spray-dried, and (2) around the core substance from a mixed aqueous solution of an ionic polymer colloid. Phase separation method (coacervation method) in which microcapsules are produced by performing phase separation on a simple emulsion through a complex emulsion, and (3) a core substance solution or dispersion is W / O or O.
/ W-type emulsion system, at the same time collecting the shell material monomer (A) at the interface, the interfacial polymerization method in which the monomer (B) and the monomer (A) react at the interface in the next step, and in situ
The u polymerization method, the liquid hardening coating method, the air suspension coating method, the electrostatic coalescence method, the vacuum vapor deposition coating method and the like can be mentioned. In the present invention, among them, the capsule toner produced by the interfacial polymerization method or the spray drying method is preferably used. In the interfacial polymerization method, not only the functional separation of the core material and the shell material is easy, but also a uniform toner can be produced in an aqueous system, and a substance having a low softening point can be used for the core material. A toner having desirable properties can be obtained.

As the shell material, a styrene resin (JP-A-48)
-80407), polyamide resin (JP-A-58)
No. 66948), an epoxy resin (JP-A-59-59).
No. 148066), a polyurethane resin (Japanese Patent Laid-open No. Sho 5
No. 7-179860), polyurea resins (Japanese Patent Laid-Open No. 62-150262), and many others have been devised. Examples of the heat-pressure fixing substance contained in the core material include thermoplastic resins having a glass transition point (Tg) of 10 ° C. or higher and 50 ° C. or lower, such as polyester resin, polyamide resin, polyester polyamide resin, and vinyl resin. .

With respect to the thermal characteristics of the core material, the structure and thermal characteristics of the shell material are significantly involved in the fixing property of the toner as a whole. Since it has both storage stability and low-temperature fixability, it is a very preferable material in the image forming method of the present invention. The main component of such a shell material is a resin having at least one bond of thermal dissociative urethane bond, thiol urethane bond, or s-thiourethane bond. Furthermore, in the heat dissociable urethane resin, which is the main component of this shell material, among the bonds involving all the isocyanate groups and / or isothiocyanate groups, the number of the bonds due to the reaction with the phenolic hydroxyl group and / or the thiol group is the number. Is 30% or more. For example, an isocyanate compound and / or an isothiocyanate compound and a phenolic hydroxyl group and / or
Alternatively, a resin obtained by a reaction with a compound having a thiol group or the like is preferably used (Japanese Patent Application No. 3-14231).
issue).

Next, the fixing method of the present invention using the above-mentioned capsule toner will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of the electrophotographic process used in the present invention. Reference numeral 1 is a photosensitive drum such as amorphous selenium, amorphous silicon, or an organic photosensitive member provided with a photosensitive layer on a conductive support. Reference numeral 2 denotes a charging device, which is installed so as to face the photoconductor drum, and which is normally used such as charging by a corotron, roller charging by a conductive roller, brush charging by a conductive brush, or the like.
Reference numeral 3 denotes an exposure device, which is installed so as to face the photoconductor drum and forms an electrostatic latent image on the photoconductor surface. As the exposure apparatus, a light source such as a semiconductor laser, an LED or an EL array is used in combination with an image forming optical system. Alternatively, an apparatus such as an optical system that projects reflected light of a document, which is generally used in a copying machine, can be used.

A developing device 4 is a device for visualizing the electrostatic latent image formed on the surface of the photoconductor with toner. As the developing device, any of the two-component magnetic brush developing device, the one-component magnetic brush developing device and the one-component non-magnetic developing device which are normally used can be used. The toner 6 charged inside the developing device passes through the developing sleeve 14 to visualize the electrostatic latent image on the surface of the photoconductor. A transfer device 5 has the same function as the charging device 2 and has substantially the same mechanism. The visible image formed on the surface of the photoconductor 1 by the developer is transferred onto the surface of the recording medium 7 in the transfer step. A cleaning device 11 removes about 5% to 20% of untransferred toner that has not been transferred in the transfer process by the cleaning device from the surface of the photoconductor.

Reference numeral 8 is a heat roller, and 9 is a pressure roller. The toner image transferred onto the recording medium is fixed on the surface of the recording medium 7 via a fixing device composed of a pair of these rollers. Reference numeral 10 denotes a radiator, which usually requires a drive system and a fan for forcibly discharging the high heat generated from the fixing device from the inside of the printing device. However, as in the present invention, the heat generation temperature of the fixing device is low and is released. When the amount of heat is small, a simple heat radiating device such as a slit or a honeycomb as shown in the figure is often sufficient.

The fixing device in the present invention comprises a heat roller 8 having a conductive elastomer layer and a pressure roller 9 which is an elastic body or a rigid body. Specifically, for example, as shown in FIG. 1, the insulating layer 12 provided around the rotation axis A.
And a heat roller 8 composed of a conductive elastomer layer which is a heat generating layer 13 provided thereon, and a pressure roller 9 which is an elastic body. Further, as shown in FIG. 2, a conductive elastomer layer, which is an elastic heating element 21, a conductive layer 22 provided thereon, a heat roller 8 including a release layer 23, and a pressure, which is an elastic body, around the rotation axis A as shown in FIG. It is composed of rollers 9. Further, as shown in FIG. 3, the heat roller 8 is composed of a conductive elastomer layer which is an elastic heating element 31 and a release layer 32 provided thereon around the rotation axis A, and a pressure roller 9 which is an elastic element. To be done. Further, as shown in FIG. 4, a heat roller 8 composed of a conductive elastomer layer which is an elastic heating element 41 and a pressure roller 9 which is a rigid body are provided around the rotation axis A.

The specific resistance value of the conductive elastomer layer is 10
0 Ω · cm or less, preferably 1 to 100 Ω · cm
Is. If the specific resistance value is 100 Ω · cm or more, the temperature of the elastomer layer does not rise sufficiently unless a high electric charge is applied, so that the heat roller may not reach the set fixing temperature and the set temperature may be reached. However, it often takes too much time. Further, if the specific resistance value is 1 Ω · cm or less, the temperature rising rate is too fast, so that not only the temperature control becomes difficult but also the temperature becomes high and the fixing device including the fixing roller may be damaged, which is not preferable. . The temperature generated in the conductive elastomer layer used in the present invention is 150 ° C. or less at the maximum exothermic temperature.

As the conductive elastomer used in the fixing device in the present invention, not only fluorine-based or silicone-based heat-resistant elastomers such as tetrafluoroethylene propylene-based, vinylidene fluoride-based, silicone-based, fluorosilicone-based, but also acrylic-based General-purpose elastomers such as nitrile, epichlorohydrin, and ethylene propylene / non-conjugated diene terpolymer (EPDM),
Depending on the conditions, neoprene-based, butadiene-based or isoprene-based elastomers can also be used.

The conductive elastomer used in the fixing device of the present invention is formed by dispersing a conductive material such as conductive carbon, conductive inorganic powder or conductive potassium titanate whiskers in the elastic body. use. Also,
Polypyrrole, polythiophene, polyparaphenylene,
A conductive layer formed by dispersing an organic polymer such as polyaniline or a charge transfer complex such as anthracene and tetracyanoquinoline or pyrene and tetracyanoethylene in the elastic body may be provided. Furthermore, in order to prevent the toner from sticking to the heat roller, a release layer may be applied with silicone oil or a film such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon, Teflon, PFA, etc. It may be provided.

Further, regarding the relationship between the radius of the elastic roller and the nip width in the conventional fixing device, as described above, the ratio of the nip width to the roller radius is usually 0.05 to 0.
Up to 20, but in the fixing device of the present invention,
The ratio of the nip width is larger than the radius of the elastic roller, and is 0.2 or more, preferably 0.25 to the radius of the elastic roller.
Adjusted to 0.8. By setting the ratio of the nip width to the roller radius to 0.2 or more of the roller radius, the amount of heat given to the toner at the time of fixing becomes large, and the fixing can be performed at a lower fixing temperature. This effect has a roller radius of 1
It is very large when it is 5 mm or less, particularly 10 mm or less.

Further, generally, in the rubber hardness of the pressure roller used in the fixing device, when the peripheral speed is slow and the roller radius is small, the elastic body is 40 to 90 degrees on the A scale of JIS standard, and the peripheral speed is high. For a roller having a large roller radius, a rubber hardness meter of C scale having a hardness of 40 to 90 degrees is used. However, in the present invention, the rubber hardness of at least one of the pair of rollers is JIS
90 degrees or less on the A scale of hardness, preferably 20 to 90
What is degree is used. When the rubber hardness of the elastic roller is 90 degrees or more on the A scale, when the nip between the rollers is designed to have a predetermined width, the linear pressure becomes too high. A pressure difference occurs between the center and both ends, and deviation in fixing property occurs. Also, 2
If it is 0 degrees or less, a sufficient linear pressure cannot be obtained with the set nip width, so that sufficient toner cannot be fixed on the recording medium. Further, if a predetermined linear pressure is to be obtained, the pressure deformation of the roller becomes too large, the load of the drive system becomes large during operation, and the rotation of the roller of the fixing device may be hindered.

As described above, in the present invention, a material having a low rubber hardness is used for at least one of the rollers, but a material having a low rubber hardness may be used for both the heat roller and the pressure roller as shown in FIG. Further, as shown in FIG. 3, an elastic body having a high rubber hardness may be used on the heat roller side in consideration of deterioration due to heat load. Further, as shown in FIG. 4, the heat roller side is made of a material having a low rubber hardness to have a wide nip width, and the pressure roller side is made of an inexpensive and durable material. A material such as SUS may be used for the pressure roller side, which is insulated with a PET film or the like. In that case, if the surface of the heat roller is conductive, it is necessary to provide a protective film on the surface of the heat roller with an insulating sheet.

The fixing device of the present invention heats the toner at a fixing temperature of 130 ° C. or lower, a sufficiently wide nip width can be obtained even with a small roller radius, and even if the distortion is large, it is extremely low so that permanent distortion does not occur. It is a fixing device that can fix with linear pressure. That is, the linear pressure in the fixing device of the present invention is 0.1 to 4.0 kg / cm, preferably 0.2 to
It is 3.0 kg / cm.

As the heat generation method of the heat roller in the fixing device of the present invention, as shown in FIG. 1, when an insulating layer is provided around the rotating shaft and a conductive elastomer layer which is a heat generating layer is provided on the insulating layer, electricity is supplied. As a means for doing so, a conductive brush or the like is brought into contact with both ends of the heat roller and applied thereto. Further, conductive paint may be applied to both end surfaces of the roller in order to enhance the application effect. Further, in the case as shown in FIG. 2, a method of applying an electric charge between the rotating shaft and the conductive elastomer layer may be used. In this manner, in the fixing device of the present invention, the heat roller and the pressure roller as described above rotate in contact with each other, and the toner image on the recording medium conveyed is energized in the conductive elastomer layer between the contact surfaces. Due to the heat generated by
Heat fixing can be performed at a fixing temperature of 130 ° C. or less.
The heat roller and the pressure roller rotate in contact with each other at a constant peripheral speed in the directions shown in the drawings by a predetermined driving means (not shown). The peripheral speed of the roller is not particularly limited and is appropriately selected.

As described above, according to the fixing method of the present invention, in the fixing step, the capsule toner adhered on the recording medium which is being conveyed is fixed at a fixing temperature of 130 ° C. or lower. A heat resistant specification member is not required, and an inexpensive material can be used, and the life of the used member is long, so that the life is long and a low-priced printing device can be realized. Also,
Since the fixing is performed at a fixing temperature of 130 ° C. or less and the linear pressure can be lowered, curling of the paper is less likely to occur and clogging of the paper is less likely to occur, resulting in less maintenance. Also, because of low temperature fixing,
Since the temperature of the heating element in the fixing device can be set low and the temperature rise is small, it is not necessary to install or reduce a forced heat dissipation device such as an electric fan in the machine, and noise can be reduced. Further, since the waiting time required for raising the temperature of the fixing device can be shortened, quick printing becomes possible, and the invention can be applied to fields requiring quick printing such as facsimile.

[0027]

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

Production Example 1 Polyester resin obtained by polycondensation of polypropylene oxide adduct of bisphenol A, polyethylene oxide adduct of bisphenol A, terephthalic acid, dodecenyl succinic anhydride and trimellitic acid (Tg is 50
° C, softening point is 120 ° C, acid value is 25) 100 parts by weight, carbon black "# 44" (manufactured by Mitsubishi Kasei) 10 parts by weight, low molecular weight polypropylene "Viscole 660P"
A mixture of 4 parts by weight (manufactured by Sanyo Kasei Co., Ltd.) was kneaded by heating with a roll. This was allowed to cool, then roughly crushed to 1-2 μm, further finely crushed with a jet mill, and then classified with an air classifier to obtain core substance particles having an average particle size of 10 μm. Separately, styrene / butyl methacrylate / butyl acrylate / acrylic acid copolymer emulsion (Tg of resin is 70 ° C, Mw 230,000, Mw
/ Mn is 6.3, the softening point is 140 ° C., and the solid content is 40.
%) 20 parts, to 58 parts of the core substance, Nigrosine dye "Bontron N-01" (manufactured by Orient Chemical Co., Ltd.) 0.4
A capsule toner was manufactured by adding weight parts and 240 parts of water and spray-drying while mixing and dispersing well. The softening point of the obtained capsule toner was 118 ° C.

Production Example 2 60 parts by weight of paraffin wax "SP-0145" (manufactured by Nippon Wax Co., Ltd.), 8 parts by weight of carnauba wax (manufactured by Noda Wax Co.), urethane compound (equimolar reaction product of hexamethylene diisocyanate and ethyl alcohol). A mixture of 32 parts by weight of a molecular weight of 450 and a softening point of 100 ° C.) and 10 parts by weight of carbon black “# 44” (manufactured by Mitsubishi Kasei) was kneaded by heating with a roll. After allowing it to cool, 1-
It was roughly crushed to 2 μm, further finely crushed with a jet mill, and then classified with an air classifier to obtain core substance particles having an average particle size of 10 μm.
Then, spray drying was performed in the same manner as in Production Example 1 above to produce a capsule toner. The softening point of the obtained capsule toner was 98 ° C.

Example 1 The encapsulated toner prepared in Preparation Example 1 was treated with 0.5% silica R972 (manufactured by Nippon Aerosil Co., Ltd.), and 50 g of this toner was mixed with 1 kg of a commercially available ferrite carrier to prepare a developer. Obtained. On the other hand, a commercially available copying machine was modified and
An apparatus according to the above was prepared, and the heat roller and the pressure roller in the fixing section were prepared according to FIG. That is, the diameter of both the heat roller and the pressure roller is 20 mm, the rubber hardness is A scale hardness meter, 60 degrees for the heat roller, and 40 for the pressure roller.
It is degree. The heat roller used is one in which a silicone resin is applied to the rotary shaft of the heat roller as an insulating layer, and carbon black is kneaded on the silicone resin to form an electrically conductive silicone resin. The volume resistivity is 3 Ω · cm. . The pressure roller is made of an elastic body made of silicone foam rubber.

The linear pressure of the fixing device is 0.3 kg / cm, the nip width is 3 mm, and both ends are applied with conductive brushes. The nip width was measured with a roll nip tester manufactured by Toshiba Silicone Co., Ltd. The ratio of the nip width and the roller radius is 0.30. Images were printed with a modified copying machine using the above-mentioned developer, and the fixing temperature was measured. As a result, a sufficient fixing strength was obtained even at 100 ° C at a peripheral speed of 25 mm / sec, and it was hot even at 150 ° C. No offset occurred. Furthermore, continuous image formation was carried out at a fixing temperature of 100 ° C. up to 50,000 sheets, but no defect due to the fixing device was found on the image. Although the heat roller and the pressure roller do not use the peeling claws that are normally used, problems such as winding of recording paper around the roller, jamming, and deformation of the paper such as wrinkles do not occur when the recording medium is carried out after fixing. There wasn't.

Example 2 The capsule toner prepared in Preparation Example 2 was treated with 0.5% silica R972 (manufactured by Nippon Aerosil Co., Ltd.), and 50 g of this toner was mixed with 1 kg of a commercially available ferrite carrier to prepare a developer. Obtained. When the fixing temperature of the developer was measured by the same apparatus and the same evaluation method as in Example 1, the peripheral speed was 25 m.
It has sufficient fixing strength even at 100 ° C at m / sec.
Hot offset did not occur even at 150 ° C. Furthermore, continuous image formation was performed at a fixing temperature of 100 ° C. up to 10,000 sheets, but no defect due to the fixing device was found on the image. Although the heat roller and the pressure roller do not use the peeling claws that are normally used, problems such as winding of recording paper around the roller, jamming, and deformation of the paper such as wrinkles do not occur when the recording medium is carried out after fixing. There wasn't.

Comparative Example The capsule toner prepared in Preparation Example 1 was treated with 0.5% silica R972 (manufactured by Nippon Aerosil Co., Ltd.), and 50 g of this toner was mixed with 1 kg of a commercially available ferrite carrier to obtain a developer. It was A fixing device using the developer in a commercially available copying machine was modified so that the temperature and the roller rotation speed were variable. The heat roller has an aluminum cylinder coated with fluororesin, a roller radius of 30 mm, and a quartz heater built in the cylinder. The rubber hardness of the pressure roller is 80 degrees on the A scale hardness meter, and the roller radius is 20.
mm, the linear pressure is 0.5 kg / cm, and the nip width is 3 mm. The ratio of the nip width and the roller radius is 0.15. Images were printed on a copying machine using the above-mentioned developer, and the fixing temperature was measured. As a result, a sufficient fixing strength was obtained even at 100 ° C. at a peripheral speed of 25 mm / sec. Occurred.

[0034]

As described above in detail, according to the fixing method of the present invention, (1) fixing is performed at a fixing temperature of 130 ° C. or less, so that the fixing device can be simplified, and the size and cost can be reduced. Becomes (2) Since the fixing is performed at a fixing temperature of 130 ° C. or less, a conventional member having a high heat resistance specification is not required, and an inexpensive material can be used, resulting in a low cost printing device. (3) Since fixing is performed at a fixing temperature of 130 ° C. or less and the linear pressure can be lowered, curling of the paper is less likely to occur and clogging of the paper is less likely to occur, resulting in less maintenance. (4) Since fixing is performed at a fixing temperature of 130 ° C. or less and a low linear pressure, the fixing device and the members around it have a long service life, which reduces maintenance. (5) Since the toner for low-temperature fixing is used, the temperature of the heating element in the fixing device can be set low, the temperature rise is small, and the forced heat dissipation device such as an electric fan does not need to be small or installed in the machine, and noise is reduced. Can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming method using a fixing device according to the present invention.

FIG. 2 is a schematic view showing an example of a fixing device according to the present invention.

FIG. 3 is a schematic view showing an example of a fixing device according to the present invention.

FIG. 4 is a schematic view showing an example of a fixing device according to the present invention.

[Explanation of symbols]

 8 Heat Roller 9 Pressure Roller 12 Insulating Layer 13 Exothermic Layer 21 Elastic Heating Element 22 Conductive Layer 23 Release Layer 31 Elastic Heating Element 32 Release Layer 41 Elastic Heating Element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Hiraoka 2223 Kitakorozawa-machi, Tokorozawa, Saitama Prefecture Japan Imaging System Co., Ltd. (72) Junichi Nakamura 2223 Kitakorozawa-machi, Tokorozawa City, Saitama Prefecture Japan Imaging System Co., Ltd. (72) Inventor Satoshi Yamaguchi 2223 Kitakorozawa-machi, Tokorozawa-shi, Saitama Japan Imaging System Co., Ltd.

Claims (4)

[Claims] 1. In a method of fixing a toner image formed of a capsule toner with a heat roller type fixing device, a conductive elastomer layer having a uniform thickness provided on the heat roller is energized and generated by heat 130. A fixing method characterized by heating and fixing at a temperature of ℃ or below. 2. The specific resistance value of the conductive elastomer is 1
The fixing method according to claim 1, wherein the fixing temperature is 00 Ω · cm or less and the maximum heat generation temperature is 150 ° C. or less. 3. A nip width between a pair of rollers in the fixing device is 0.2 or more of an elastic roller radius.
The fixing method described. 4. The rubber hardness of at least one roller is
The fixing method according to claim 1, wherein the A scale of JIS hardness is 90 degrees or less.