JP3236878B2 - Heat fixing method and heat fixing toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic printing,
In magnetic recording, etc., a visible image formed with toner is
The present invention relates to a fixing method for fixing to a recording material and a toner used in the fixing method.

[0002]

2. Description of the Related Art Conventionally, as a method for fixing a visible image of a toner to a recording material, a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and pressing against the heating roller are undetermined. A hot roll fixing method in which a recording material holding an attached toner visible image is heated while being nipped and conveyed is often used.

A belt fixing system described in US Pat. No. 3,578,797 is also known.

However, in the above-mentioned conventional hot roll fixing method, (1) there is a so-called wait time during which the image forming operation is prohibited until the heat roller reaches a predetermined temperature. (2) The heating roller is maintained at an optimum temperature in order to prevent a fixing failure due to a fluctuation in the temperature of the heating roller due to the passage of the recording material or other external factors and a transfer of toner to the heating roller, ie, an offset phenomenon. In order to achieve this, the heat capacity of the heating roller or the heating element must be increased, which requires a large amount of electric power. (3) Since the temperature of the roller is low, when the recording material is discharged through the heating roller, the recording material and the toner on the recording material are slowly cooled, so that the toner has a high tackiness. In combination with the curvature of the recording material, an offset or a paper jam due to the entanglement of the recording material may occur. (4) The configuration is such that the high-temperature heating roller is directly in contact with the hand, which causes a problem in safety or requires a protection member.

[0005] In the belt fixing system described in US Pat. No. 3,578,797, the above-mentioned problems (1) and (2) of heat roll fixing have not been fundamentally solved.

Further, Japanese Patent Application Laid-Open No.
No. 147,881 discloses a fixing device that heats a toner visible image via a moving heat-resistant sheet by means of a low-heat-capacity heating element which is heated in a pulsed manner, and has a short wait time and low power consumption by a fixing device. Has been proposed. Similarly, Japanese Patent Application Laid-Open No. 63-12069, which was previously proposed by the present applicant, discloses a fixing device for heating and fixing a visible image of a toner to a recording material via a heat-resistant sheet. A fixing device that has a layer and a release layer or a low-resistance layer to effectively prevent an offset phenomenon has been proposed.

[0007]

However, a fixing method which has a short wait time and low power consumption while realizing excellent fixability of toner-visible images to a recording material and anti-offset property has been realized. In order to achieve durability, in addition to the fixing device as described above, the characteristics of the toner are greatly affected.

That is, an object of the present invention is to solve the above-mentioned problems, to substantially eliminate the wait time, or to have a very short wait time. It is an object of the present invention to provide a novel heat fixing method which can fix images well and can achieve high durability.

Another object of the present invention is to provide a heat fixing toner which is preferably used in the heat fixing method provided in the present invention.

[0010]

The present invention relates to a heat fixing method for heating and fixing a visible image of a toner on a recording material, wherein the toner comprises 100 parts by weight of a binder resin and 30 to 150 parts by weight of a magnetic material. And the shape of the toner is 0.95 to 1.00 at a Wardell's practical sphericity Δw.
A fixedly supported heating element, a film in contact with the visible image of the toner on the recording material, and an opposing pressure contact with the heating element, and a total pressure of the recording material against the heating element via the film. And a pressure member that is brought into close contact with the toner at a pressure of 4 to 20 kg. The present invention relates to a heat fixing method characterized by heating and fixing an image on a recording material.

Further, the present invention provides a heating member fixed and supported, a film abutting on a visible image of toner on a recording material,
A pressure member that opposes to the heating body and makes the recording material adhere to the heating body at a total pressure of 4 to 20 kg via the film, wherein the heating body is coated with a resistive material on a substrate. Work
In the heat fixing toner used in the heat fixing method of heating and fixing a visible image of a toner to a recording material using a heat fixing device that is a linear heating element that generates heat by energization, the toner is a binder resin 100 Parts by weight and magnetic material 30 to 15
The present invention relates to a toner for heat fixing, wherein the toner contains 0 parts by weight, and the shape of the toner is 0.95 to 1.00 with a Wardell's practical sphericity Δw.

Hereinafter, the heat fixing step of the present invention applicable to the heat fixing method will be specifically described.

FIG. 1 is a structural view of a fixing device according to the present invention.

Reference numeral 11 denotes a linear heating element having a low heat capacity fixedly supported by the apparatus, and has a thickness of 1.0 mm and a width of 10 m as an example.
m, an alumina substrate 12 having a longitudinal length of 240 mm
3 is applied to a width of 1.0 mm and is energized from both ends in the longitudinal direction. The energization is performed by applying a pulse having a pulse shape corresponding to a desired temperature and energy release amount controlled by the temperature detecting element 14 with a pulse width of 20 msec of DC 100 V while changing the pulse width. Approximate pulse width is 0.5mse
c to 5 msec. The fixing film 15 moves in the direction of the arrow in FIG.

When the temperature detected by the temperature measuring element 14 in the low heat capacity linear heating element 11 is T ₁ , the surface temperature T ₂ of the film 15 facing the resistance material 13 is substantially equal to T ₁ .
The film surface temperature T ₃ at a portion where the film 15 is peeled from the fixed toner surface is substantially equal to the temperature and the temperatures T ₁ and T _2.

In the present invention, the heating element has a smaller heat capacity than a conventional heating roll and has a linear heating section, and the maximum temperature of the heating section is preferably 100 to 300 ° C.

The film located between the heating element and the pressing member is preferably a heat-resistant sheet having a thickness of 1 to 100 μm. PET (polyethylene terephthalate), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE
In addition to a polymer sheet such as (polytetrafluoroethylene), polyimide, and polyamide, a metal sheet such as aluminum and a laminate sheet composed of a metal sheet and a polymer sheet are used.

A more preferred film structure is that these heat-resistant sheets have a release layer and / or a low-resistance layer. As a specific example, a release layer obtained by adding a conductive material to a fluororesin is used. Is an endless film coated with.

Here, the film is driven by a driving roller 16.
And the driven roller 17 moves without wrinkles in the direction of the arrow due to the tension.

Reference numeral 18 denotes a pressure roller having a rubber elastic layer having good releasability, such as silicone rubber, which presses the heating element through the film at a total pressure of 4 to 20 kg and rotates by pressing against the film. The unfixed toner 20 on the transfer material 19 is
The image is guided to a fixing section by 1 and a fixed image is obtained by the above-described heating.

The above description has been made with reference to the endless belt.
As described above, the sheet feed shaft 22 and the take-up shaft 23 are used, and the fixing film may be an edged film.

The image forming apparatus is applicable to all fixing apparatuses such as a copying machine, a printer, and a facsimile which form an image using toner.

Next, a developer applicable to the image forming method of the present invention will be described.

The developer according to the present invention is characterized in that the shape thereof is 0.95 to 1.00 with a practical sphericity Δw of Wardel. The Wardel's practical sphericity Ψw described here is

[0025]

(Equation 1) Is the value represented by

By adopting the above-mentioned constitution, the developer of the present invention is very unlikely to cause flaws and abrasion on the surface of the fixing film, as well as contamination and fixation.

From the above, the developer according to the present invention is:
It has been found that the present invention provides a heat-fixing method that makes full use of the ability of the fixing step according to the present invention and always performs good heat-fixing.

The present inventors consider the reason why the developer according to the present invention exhibits the above-described effects as follows. That is, a powder having a flat portion in a particle is adsorbed between flat surfaces, and requires a higher energy than a case where the powder is in contact with a curved surface to separate the bond. Therefore, by increasing the sphericity of the developer and reducing the contact area with the fixing sheet against mechanical pressure and sliding on the toner fixing surface, the adhesive force of the developer is reduced, It is presumed that scratches and shavings due to rubbing on the surface of the fixing sheet, as well as dot-like or linear sticking phenomena resulting therefrom are prevented.

The toner according to the present invention is generally manufactured as follows. The binder resin, and if necessary, the magnetic substance, the coloring agent as a coloring agent, and the like are uniformly dispersed by a mixer such as a Henschel mixer. The dispersion obtained as described above is melt-kneaded with a kneader, extruder, roll mill or the like. The kneaded material is roughly pulverized by a cutter mill, a hammer mill or the like, and then finely pulverized by a jet mill or the like. The finely pulverized material is classified using a zigzag classifier or the like, with a uniform particle size distribution. The classified powder obtained as described above is discharged from a nozzle into a hot air stream with compressed air by a spray drier or the like, atomized, and cooled or dried to obtain a toner.

Other methods for producing the toner include a polymerization method and a capsule method. The outline of these production methods is described below.

(Polymerization Method Toner) A polymerizable monomer, and if necessary, a polymerization initiator, a colorant and the like are granulated in an aqueous dispersion medium. The granulated monomer composition particles are classified into an appropriate particle size. The monomer composition particles having a specified internal particle diameter obtained by the classification are polymerized. After an appropriate treatment to remove the dispersant, the polymerization product obtained above is filtered, washed with water and dried to obtain a toner.

(Capsule Toner) A resin, magnetic powder and the like, if necessary, are kneaded with a kneader or the like to obtain a molten toner core material. The toner core is placed in water and stirred vigorously to produce a fine particle core. The core material fine particles are put in a shell material solution, and a poor solvent is added dropwise with stirring, and the core material is covered with the shell material for encapsulation. The resulting capsule is filtered and dried to obtain a toner.

(Spray Method Toner) A binder resin, a magnetic material, a dye and a pigment as a colorant, etc. are kneaded with a kneader or the like, cooled, finely pulverized, and then classified to obtain a toner core material. A fine powder of a resin or a polymer material is vigorously stirred and uniformly dispersed in the toner core material. The dispersion thus obtained is discharged from a nozzle into a hot air stream with compressed air by a spray dryer or the like, atomized, and cooled or dried to obtain a toner.

As the binder resin of the toner according to the present invention, a homopolymer of styrene such as polystyrene and polyvinyltoluene and a substituted product thereof; a styrene-propylene copolymer, a styrene-vinyltoluene copolymer and a styrene-vinylnaphthalene copolymer Polymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer,
Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene -Butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene Styrene-based copolymers such as copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene 、 Po Vinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resins, phenol resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, and carnauba wax may be used alone or in combination.

In particular, as the binder resin in the core material of the capsule toner, generally known materials can be used, and as the pressure fixing property or the low temperature fixing toner generally used as the microcapsule toner, Soft solid substances are preferably used. Such substances include waxes (dense wax, carnauba wax, paraffin wax, microcrystalline wax, etc.), higher fatty acids (stearic acid, palmitic acid,
Lauric acid, etc., higher fatty acid metal salts (aluminum stearate, lead stearate, barium stearate,
Magnesium stearate, zinc stearate, zinc palmitate, etc.), higher fatty acid derivatives (methyl hydroxystearate, glycerol monohydroxystearate, etc.), polyolefins (low molecular weight polyethylene,
Low molecular weight polypropylene, polyethylene oxide, polyisobutylene, polytetrafluoroethylene, etc., olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic ester copolymer, ethylene-methacrylic acid copolymer, ethylene- Methacrylic acid ester copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer resin, etc., styrene resin (low molecular weight polystyrene, styrene-butadiene copolymer (monomer weight ratio 5 to 30: 95-70), styrene-acrylic compound copolymer, etc.), epoxy resin, polyester resin (acid value 10 or less), rubbers (isobutylene rubber, nitrile rubber, chloride rubber, etc.), polyvinylpyrrolidone, polyamide, cumarone-indene Resin, methyl vinyl ether-anhydrous Maleic acid copolymer, maleic acid-modified phenol resins, phenol-modified terpene resins, include silicone resins may be used singly or in combination among them.

As the crosslinking agent used in the toner of the present invention, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane,
Examples thereof include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-diallyl phthalate, trialcyanurate, triallyl asocyanurate, triallyl isocyanurate, triallyl trimellitate, and diallyl chloride.

When the resin of the present invention is produced or when the toner is obtained by a polymerization method, the selection of the type of the initiator, the solvent and the reaction conditions are important factors for obtaining the resin of the present invention. .

The polymerization initiator is generally a compound that generates a radical upon being decomposed by heat or light, and is an azobisnitrile type compound such as 2,2′-azobisisobutyronitrile and 2,2′-azobispronitrile. Pionitrile, 2,
2'-azobisvaleronitrile, 2,2'-azobis-
(2,4-dimethyl) valeronitrile and the like.

As organic peroxides, for example, benzoyl peroxide, nucleated benzoyl peroxide, lauroyl peroxide,
Acetyl peroxide, cumene hydroperoxide, and the like.

The azo and diazo compound systems include diazoaminobenzene, azothioether and the like.

Examples of the sulfines include aromatic sulfinic acids.

When the developer of the present invention is produced by a polymerization method, a stabilizer may be added to the reaction solution as long as it does not substantially adversely affect the developer. As a specific example, an inorganic compound in the form of a hardly soluble fine powder, for example, BaSO
₄ , CaSO ₄ , MgCO ₃ , BaCO ₃ , CaCO ₃ , C
a ₃ (PO ₄ ) ₂ , poorly soluble salts, inorganic polymers such as diatomaceous earth, talc, silicic acid, clay, talc, powders of metal oxides, water-soluble polymers such as polyvinyl alcohol, gelatin, starch, Examples include methylcellulose, ethylcellulose, carboxymethylcellulose, polyacrylic acid and their salts, alginate and the like. These stabilizers are usually used in the range of 0.1 to 10% by weight.

In order to finely disperse the hardly soluble inorganic compound in the form of a fine powder, a surfactant may be used in the range of 0.001 to 0.1% by weight.

Examples of the surfactant used for such a purpose include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium allyl-alkyl polyethersulfonate, sodium oleate, polyoxyethylene alkyl ether, and polyoxyethylene alkyl ether. A nonionic activator such as oxyethylene alkyl allyl ether is usually used.

As the colorant contained in the developer according to the present invention, generally known dyes and pigments can be used.
Such dyes and pigments include, for example, carbon black, nigrosine dye, lamp black, Sudan black S
M, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgazine Red, Paranitroaniline Red, Toluidine Red, Carmin FB, Permanent Bordeaux F
RR, Pigment Orange R, Risor Red 2
G, rake red C, rhodamine FB, rhodamine B
Lake, methyl violet B lake, phthalocyanine blue, pigment blue, brilliant green B, phthalocyanine green, oil yellow GG, Zapon First Yellow CGG, Kayaset Y963,
Kayaset YG, Sumiplast Yellow GG, Zapon Fast Orange RR, Oil Scarlet, Sumiplast Orange G, Orazol Brown B, Zapon First Scarlet CG, Aizen Spiron Red BEH, Oil Pink OP, etc. can be applied. These colorants are generally used to obtain a capsule toner for a two-component developer, and are used in an amount of 5 to 20 with respect to the core material binder.
% Is preferably added.

As the magnetic fine particles contained in the toner according to the present invention, a metal composed of a ferromagnetic element such as ferrite, magnetite, iron, cobalt, nickel or the like, or an alloy or compound containing the same, or a ferromagnetic element Alloy that does not contain the element, but becomes ferromagnetic by appropriate heat treatment or the like, for example, is called a Heusler alloy containing manganese and copper such as manganese-copper-aluminum or manganese-copper-tin. Alloys, or chromium dioxide, and the like. The content ratio of the fine powder of the magnetic substance can be 30 to 150 parts by weight, preferably 40 to 100 parts by weight, based on 100 parts by weight of the binder resin.

As the charge control agent contained in the toner according to the present invention, a conventionally known charge control agent is selected. As specific examples of the positive charge control agent, generally, nigrosine, carbon number 2
Azine dyes containing up to 16 alkyl groups (Japanese Patent Publication No.
No. 1627), basic dyes (for example, CI Basic)
Yellow 2 (CI.41000), C.I. I.
Basic Yellow 3, C.I. I. Basic
Red 1 (CI. 45160), C.I. I. Basi
c Red 9 (CI. 42500), C.I. I. Ba
sic Violet 1 (CI. 42535),
C. I. Basic Violet 3 (CI.42
555), C.I. I. Basic Violet 10
(CI. 45170), C.I. I. Basic Vio
let 14 (CI. 42510), C.I. I. Bas
ic Blue 1 (CI. 42025), C.I. I.
Basic Blue 3 (CI. 50005),
C. I. Basic Blue 5 (CI. 4214)
0), C.I. I. Basic Blue 7 (CI.4
2595), C.I. I. Basic Blue 9 (C.I.
I. 52015), C.I. I. Basic Blue 2
4 (CI. 52030), C.I. I. Basic Bl
ue 25 (CI52025), C.I. I. Basi
c Blue 26 (CI.44025), C.I. I.
Basic Green 1 (CI. 42040),
C. I. Basic Green 4 (CI. 420)
Lake pigments of these basic dyes (for example, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.) , C.I. I. Sovent Black 3
(C.I. 26150), Hansa Yellow G (C.I.
11680), C.I. I. Moldrant Black
11, C.I. I. Pigment Black 1 etc.

Further, for example, polyamine resins such as quaternary ammonium salts such as benzolmethyl-hexadecyl ammonium chloride and decyl-trimethyl ammonium chloride, vinyl polymers containing amino groups, and condensation polymers containing amino groups, and the like. ,
Preferred are nigrosine, quaternary ammonium salts, triphenylmethane-based nitrogen-containing compounds, and polyamines.

Specific examples of the negative charge control agent include JP-B Nos. 41-20153, 42-27596 and 44.
Metal complex salts of monoazo dyes described in JP-A-6397 and JP-A-45-26478;
Nitrohumic acid and salts thereof described in JP-A-133338; I. No. 14,645, and the like, and salicylic acid, naphthoic acid and dicarboxylic acid Zn described in JP-B-55-42752, JP-B-58-41508, JP-B-58-7384, and JP-B-59-7384. , Al, Co, Cr, Fe and other metal complexes,
Examples include sulfonated copper phthalocyanine pigments, styrene oligomers into which nitrile groups and halogens have been introduced, and chlorinated paraffins. Especially from the aspect of dispersibility,
Preferred are metal complex salts of monoazo dyes and metal complexes of salicylic acid, alkyl salicylic acid, naphthoic acid and dicarboxylic acid. The addition amount of these charge control agents minimizes adverse effects such as a decrease in developing power and a decrease in environmental stability due to contamination of the developing sleeve surface by the charge control agents while maintaining good triboelectricity as described above. In order to suppress this, the addition amount is preferably 0.1 to 3 parts by weight based on 100 parts by weight of the binder resin.

The developing agent of the present invention may further contain other additives as long as it does not substantially adversely affect the developer.
Specific examples thereof include a lubricant such as Teflon and zinc stearate, or an abrasive such as cerium oxide, silicon carbide and strontium titanate; a fluidity imparting agent such as colloidal silica and aluminum oxide; a caking inhibitor; Examples thereof include a conductivity-imparting agent such as carbon black, zinc oxide, antimony oxide, and tin oxide; a fixing aid such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, and various waxes; and an anti-offset agent. Further, a small amount of white fine particles and black fine particles of opposite polarity can be used as a developing property improver.

As a method for developing the toner, all known methods can be applied. For example, a two-component developing method such as a cascade method, a magnetic brush method, or a microtoning method; a one-component developing method containing a magnetic substance such as a conductive one-component developing method, an insulating one-component developing method, or a jumping developing method; Cloud method and fur brush method; a non-magnetic one-component developing method in which the toner is held on a toner carrier by electrostatic force and conveyed to a developing unit to be developed.

The basic configuration and features of the present invention have been described above. The method of the present invention will be specifically described below with reference to examples. However, this does not limit the embodiment of the present invention at all.

[0053]

EXAMPLES Example 1 Magnetic particles (magnetite, bulk density = 1.10 g / cm ³ ) 60 parts by weight Styrene-n-butyl acrylate copolymer 100 parts by weight (copolymerization weight ratio 8: 2, Mw = 22) 10,000) Negative charge control agent (monoazo dye-based chromium complex) 1 part by weight Low molecular weight polypropylene (Mw = 6,000) 3 parts by weight The above mixture is melt-kneaded with a biaxial extruder heated to 140 ° C., and cooled. The kneaded material was coarsely pulverized by a hammer mill, the coarsely pulverized material was finely pulverized by a jet mill, and the obtained finely pulverized powder was classified by wind power to obtain a classified powder having a volume average particle diameter of 12 μm.

Next, a spherical toner was obtained from the classified powder by using a spray drier (manufactured by Mitsubishi Kakohki).

This toner was substantially spherical, and the practical sphericity of Wardell was 0.96 as an average value of 100 toner particles.

Next, a hydrophobic colloidal silica was mixed with the spherical toner using a Henschel mixer to obtain a developer.

Next, this developer is used in the heating and fixing device of the present invention shown in FIG. 1 in which the surface temperature t ₁ of the heating element of the heating element 11 is 200 ° C., the power consumption of the resistance material of the heating section is 150 W, and the heating element is heated. The total pressure between the pressure roller 11 and the pressure roller 21 is 13 kg, the nip between the pressure roller and the film is 3 mm, and the fixing film 1
8 with a rotation speed of 48 mm / sec (Canon laser beam printer LBP-SX)
Continuously forming toner images using a remodeling machine)
A live-action test of the sheets was performed. At this time, a polyimide film having a thickness of 20 μm and having a low-resistance release layer in which a conductive material is dispersed in PTFE on a contact surface with a recording material was used as a fixing film. As a result, it took about 3 seconds for the surface temperature T _{1 of} the heating element to reach 183 ° C. Further, the temperature T ₂ is 180 ° C. and the temperature T ₃ is 1
79 ° C.

After the actual photographing test, no fixation of the residual developer occurred on the surface of the fixing film, and further, good durability was exhibited with almost no scratches or scraping. In addition, no offset phenomenon was observed in the obtained image, and the fixability was sufficient.

Example 2 100 parts by weight of polyethylene wax (softening point: 120 ° C.) 80 parts by weight of magnetite The above mixture was kneaded using a roll mill, cooled, pulverized, and then classified to obtain a colored fine powder of 10 to 25 μm. Was.

On the other hand, Petrocoat RJ1200 (composition name: oxidized starch, softening point: 140 ° C., trade name of Nisse Chemical Industry Co., Ltd.)
1 μm powder was obtained.

Next, 10 parts by weight of the classified fine powder of Petrocoat was mixed for 1 minute with a Henschel mixer with 100 parts by weight of the colored fine powder, and then the spray gun of a spray drier manufactured by Mitsubishi Kakoki Co., Ltd. was used for EHP- manufactured by Nippon Devilbiss.
Except for changing the 604 system nozzle pressure to 1 kg / cm ² , the toner was atomized in a hot air flow (inlet 200 ° C., outlet 100 ° C., water pressure difference between inlet and outlet 50 mm water column) to obtain toner.

The practical sphericity of Wardell of this toner was 0.97 as an average value of 100 toner particles.

When the surface of this toner was observed with an electron microscope, it was found that fine particles of petrocoat were uniformly covered with the fine particles of colored powder and partially embedded, and the particles were firmly adhered to each other.

Next, a hydrophobic colloidal silica was mixed with the spherical toner using a Henschel mixer to obtain a developer.

Next to this developer, the temperature detection element surface temperature t ₁ of the heating body 11 190 ° C., the rotational speed of the fixing film 1
An image forming apparatus having a heat fixing unit (Canon-made electronic copying machine NP-120 remodeled machine) was used in the same manner as in Example 1 except that it was set to 40 mm / sec, except that the toner was set in the same manner as in Example 1. A continuous shooting test of 2,000 continuous sheets for forming an image was performed. As a result, there was no sticking of the residual developer to the fixing film, furthermore, there was almost no scratch or scraping, good durability was exhibited, and a sufficiently fixed image was obtained without any offset phenomenon.

Example 3 95 parts by weight of paraffin wax 5 parts by weight of diethylaminomethyl methacrylate polymer 80 parts by weight of magnetic powder 3 parts by weight of carbon black The above mixture was treated at 100 ° C. with an attritor (made by Mitsui Miike Co.) filled with stainless steel balls. The mixture is melt-dispersed for 2 hours to form a dispersoid melt mixture.

Separately, add 16 liters of water to a 20 liter Ajihomomixer (manufactured by Tokushu Kika),
And heat. Here, 80 parts by weight of Aerosil # 300 (manufactured by Nippon Aerosil Co., Ltd.) colloidal silica is charged and uniformly dispersed by stirring. Thereafter, the molten mixture is heated to 110 ° C. and charged into an azihomomixer. After the addition of the molten mixture, the dispersion medium containing these suspended dispersoid particles was discharged into ice water, and the dispersoid particles were rapidly cooled and solidified to obtain substantially spherical particles. After returning to room temperature, 400 parts by weight of sodium hydroxide was added, and the mixture was stirred with a propeller mixer to dissolve the colloidal silica. The dispersion is filtered by a centrifuge, washed with water and dried,
After crushing the obtained core material, it was used as a core material for encapsulation.

Styrene-diethylaminoethyl methacrylate (95: 5) copolymer (Mw about 12,000) 2
A resin solution was prepared by dissolving 0 parts by weight in 380 parts by weight of N, N dimethylformamide. 5.6 kg of the above solution was put into an encapsulation reaction tank, and after cooling to −25 ° C., 215 g of acetic acid was added and stirred for several minutes. 2 kg of the core material was added thereto, and the mixture was stirred for 10 minutes. As a result, the core material was uniformly dispersed in the solution. After adding cold water to precipitate the resin, the dispersion was taken out of the reaction tank, and the solid content and the solvent were separated by a centrifugal filter. This solid content was washed with water, further subjected to centrifugal filtration, and then dried with a ventilation dryer. The dried colloidal silica was externally added using a Henschel mixer to obtain a microcapsule toner. The practical sphericity of Wardell of this toner was 0.97 as an average value of 100 toner particles.

Next, an image forming apparatus (manufactured by Canon Inc.) having a heat fixing device set in the same manner as in Example 1 except that this developer is used as the heat fixing device shown in FIG. 1 and the rotational speed of the fixing film is set to 66 mm / sec. Using an electronic copying machine (PC-30 remodeling machine), a continuous shooting test of 1,000 continuous sheets was performed.
As a result, no fixation of the residual developer occurred on the fixing film. Further, no offset phenomenon was observed in the obtained image, and the fixability was sufficient.

[0070]

As described above, the present invention prevents the fixing sheet from being scratched or abraded by the developer and further prevents the residual toner from being fixed due to the toner. While waiting time is short,
A low power consumption fixing method was realized, and high durability was achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a heat fixing device according to the present invention.

FIG. 2 is an explanatory view schematically showing a heat fixing device having a fixing film winding device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Heating body 12 Alumina substrate 13 Resistance material 14 Temperature measuring element 15 Fixing film 16 Drive roller 17 Follower roller 18 Pressure roller 19 Recording material 20 Unfixed toner 21 Inlet guide 22 Sheet feed shaft 23 Take-up shaft

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoko Tsuchiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yukari Ishibashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-2-168270 (JP, A) JP-A-2-168271 (JP, A) JP-A-2-256063 (JP, A) JP-A-2-297564 (JP, A A) JP-A-2-161451 (JP, A) JP-A-59-218459 (JP, A) JP-A-59-218460 (JP, A)

Claims (6)

(57) [Claims] In a heat fixing method for heating and fixing a visible image of a toner on a recording material, the toner comprises a binder resin
A fixed and supported heating element, wherein the heating element contains about 00 parts by weight and 30 to 150 parts by weight of a magnetic substance, and the toner has a practical sphericity Ψw of 0.95 to 1.00 in a shape of a toner.
A film contacting the visible image of the toner on the recording material, and a pressing member which is pressed against the heating member and makes the recording material adhere to the heating member through the film at a total pressure of 4 to 20 kg. The heating element is characterized in that a resistive material is coated on a substrate, and a visible fixing image of the toner is heat-fixed to a recording material by using a heating fixing device that is a linear heating element that generates heat when energized. Heat fixing method. 2. The toner according to claim 1, wherein the toner comprises a soft solid substance and a negative charge.
Claims characterized by further containing a control agent
Item 2. The heat fixing method according to Item 1. 3. The binder resin is a styrene copolymer.
3. The heat fixing method according to claim 1, wherein
Law. 4. A fixed supported heating member, the toner of the visualized image contacting film on record material, faces pressed against the the heating body, and the recording material through the film in the heating body Total
A pressure member that is brought into close contact with a pressure of 4 to 20 kg . The heating element is formed by applying a resistive material on a substrate and using a heating and fixing device that is a linear heating element that generates heat when energized. In a heat fixing toner used in a heat fixing method for heat fixing an image on a recording material, the toner comprises 100 parts by weight of a binder resin and a magnetic material 3.
A heat fixing toner containing 0 to 150 parts by weight and having a toner having a practical sphericity Δw of 0.95 to 1.00. 5. The toner according to claim 1, wherein the toner comprises a soft solid substance and a negative charge.
Claims characterized by further containing a control agent
Item 6. The heat fixing toner according to Item 4. 6. The binder resin is a styrene copolymer.
6. The fixing method according to claim 4, wherein the fixing is performed by heating.
toner.