JP3096856B2 - Heat fixing developer and heat fixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as a method for fixing a visible image of a developer (toner) to a recording material, a pressure roller having an elastic layer and a heating roller maintained at a predetermined temperature and pressing against the heating roller is used. Thus, a hot roll fixing method of heating while nipping and transporting a recording material holding an unfixed developer visible image is often used.

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

[0004]

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) Maintaining the heating roller at an optimum temperature in order to prevent the fixing failure due to the fluctuation of the temperature of the heating roller due to the passage of the recording material or other external factors, the transfer of the developer to the heating roller, and the so-called offset phenomenon. Therefore, it is necessary to increase the heat capacity of the heating roller or the heating element, which requires a large amount of electric power. (3) When the roller is at a low temperature, the recording material and the developer on the recording material are slowly cooled when the recording material is discharged through the heating roller, so that the adhesiveness of the developer is high. Also, in combination with the curvature of the roller, a paper jam may occur due to offset or entanglement of the recording material. (4) The configuration is such that the high-temperature heating roller is directly in contact with the hand, and there is a problem in safety or a protective member is required.

Also, in the belt fixing system described in US Pat. No. 3,578,797, the above-mentioned problems (1) and (2) of the heat roll fixing are not fundamentally solved.

Further, Japanese Patent Application Laid-Open No.
No. 147,884 discloses a fixing device that heats a developer visible image through a moving heat-resistant sheet by means of a low-heat-capacity heating element that is heated in a pulsed manner, and fixes the image on a recording material. 2. Description of the Related Art An image forming apparatus with low power consumption 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 developer to a recording material via a heat-resistant sheet. A fixing device that has a heat-resistant layer and a release layer or a low-resistance layer and is effective in preventing an offset phenomenon has been proposed.

However, in order to realize a fixing method that has a short wait time and low power consumption while achieving excellent fixability of a developer-developed image to a recording material, stability of an image, and the like,
In addition to the fixing device as described above, the properties of the developer are greatly affected.

That is, in recent years, small and inexpensive personal use copying machines and laser printers have emerged. In these small machines, from the maintenance-free standpoint, a cartridge integrating a photoconductor, a developing device, a cleaning device, and the like has been developed. It is desirable to use a magnetic one-component developer because the method is used and the structure of the developing device can be simplified as the developer. Further, in these small-sized machines, it is desired that the developer be a low-melting-point developer in order to save power and alleviate the temperature rise in the machine.
In addition, these developers tend to be further finely divided in order to achieve high image quality.

In such a developer, there has been a problem that the surface of the fixing device is contaminated due to excessive melting of the toner and eventually becomes a fixed substance.

This problem becomes more serious when used in the heat fixing method according to the present invention. Since the fixing member of the present invention is in the form of a film, when the developer is fixed as described above, the tension of the film is disturbed, and the fixing property becomes uneven, the image is blurred, and the film is cracked. Troubles may occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and to fix a developer image onto a recording material with substantially no or extremely short wait time, and with low power consumption. An object of the present invention is to provide a novel heat-fixing method which is favorable and can obtain a stable image for a long period of time.

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

Still another object of the present invention is to provide a heat fixing method which does not use a high-temperature rotating roller and does not require a heat-resistant special bearing.

Still another object of the present invention is to provide a heat fixing method which is excellent in safety or does not require a protective member by having a fixing device structure which does not directly touch the high-temperature body. is there.

[0015]

The above object is achieved by the present invention described below. That is, the present invention heats a visible image of a developer to a recording material by a fixedly supported heating body and a pressing member which is pressed against the heating body and presses the recording material to the heating body through a film. A fixing method for fixing, wherein the film is used in a fixing method using an endless polyimide film having a release layer in which a conductive substance is dispersed in polytetrafluoroethylene on a contact surface with the visible image. Agent, the developer is a binder resin,
Contains a colorant and a negative charge control agent, and has a residual monomer amount of 1
The present invention relates to a heat-fixing developer characterized by being a negatively chargeable developer of 50 ppm or less, and a heat-fixing method characterized by using the developer.

In the present invention, in particular, by controlling the residual monomer content of the developer used in the heat fixing method to 150 ppm or less, contamination and fixation of the surface of the fixing film by the developer are prevented, and excellent fixing property and stable fixing are achieved. It is possible to realize a fixing method with a short wait time and low power consumption while achieving an image, and achieve high durability.

Next, the present invention will be described in detail.

The configuration of the heat fixing device of the present invention applicable to the fixing method of the present invention will be specifically described.

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. (Polyethylene terephthalate), PFA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, polyamide, etc., as well as metal sheets such as aluminum and metal sheets and polymer sheets The configured laminated sheet is used.

A more preferable structure of the film is that these heat-resistant sheets have a release layer and / or a low-resistance layer. As a specific example, a conductive material (conductive material) is added to a fluororesin. It is an endless film coated with a release layer added.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a structural diagram of an example of a fixing device for carrying out the method of the present invention.

Reference numeral 11 denotes a linear heating element having a low heat capacity fixedly supported by the apparatus, for example, having a thickness of 1.0 mm and a width of 10 m.
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 corresponding to a desired temperature and energy release amount controlled by the temperature detecting element 14 by changing the pulse width in a pulse-like waveform of DC 100 V and a cycle of 20 msec. Approximate pulse width is 0.5 ms
c to 5 msec.

The fixing film 15 moves in the direction of the arrow in FIG. As an example of this fixing film, a thickness of 20 μm
Heat-resistant film, for example, polyimide, polyetherimide, PES, PFA on at least the image contact surface side PT
This is an endless film in which a release layer obtained by adding a conductive substance to a fluororesin such as FE or PAF is coated by 10 μm. Generally, the total thickness is less than 100 μm, preferably less than 40 μm. The film drive moves without wrinkles in the direction of the arrow due to the drive and tension by the drive roller 16 and the driven roller 17.

Reference numeral 18 denotes a pressure roller having a rubber elastic layer of silicon rubber or the like with good releasability, 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 developer 20 on the transfer material 19 is guided to a fixing section by an entrance guide 21 and obtains a fixed image by the above-described heating.

The endless belt has been described above. However, as shown in FIG. 2, a sheet feed shaft 22 and a take-up shaft 23 are used, and the fixing film may be an edged film.

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

In the low heat capacity linear heating element 11, when the temperature detected by the temperature detecting element 14 is T ₁ , the surface temperature T ₂ of the film 15 facing the resistance material 13 is substantially equal to T ₁ . Further, the film surface temperature T ₃ at a portion where the film 15 is peeled from the developer fixing surface is substantially equal to the temperature and the temperatures T ₁ and T _2.

Next, a developer applicable to the heat fixing system of the present invention will be described.

The developer according to the present invention is characterized in that the residual monomer content is 150 ppm or less.

The developer of the present invention, having the above-described structure, is very unlikely to cause contamination and fixation on the surface of the fixing film.

From the above, the developer according to the present invention has extremely good matching with the heat fixing method according to the present invention,
It has been found that the ability of the heat fixing system according to the present invention is sufficiently exhibited, and that it always contributes to good image formation.

In the present invention, the residual monomers include not only unreacted monomers generated during the synthesis of the binder resin composition described later, but also low-molecular-weight by-products derived from the unreacted monomers, for example, benzaldehyde and benzoic acid by an oxidation reaction. , Ethylbenzene generated by hydrogenation.

As a specific method of reducing the residual monomer, various known techniques can be used. However, in order to reduce the residual monomer contained in the developer, it is necessary to reduce the amount of the residual monomer during the production of the developer. For example, when the binder resin and the colorant are kneaded by hot-melt, it is preferable to use a method in which the mixture is heated strongly or volatile components are removed by suction.

The amount of the residual monomer in the developer is determined by the following method using a gas chromatograph.

Using 2.55 mg of DMF as an internal standard, 1
Add 00 ml of acetone to make a solvent with internal standard. Next, 400 mg of the developer is made into a 10 ml solution with the above solvent. After 30 minutes on an ultrasonic shaker, leave for 1 hour. Next, the mixture is filtered with a 0.5 μm filter. The volume of the implanted sample is 4 μl.

The conditions of the gas chromatograph are as follows: Capillary column (30 m × 0.249 mm, DBW
(AX, film thickness 0.25 μm) ・ Detector FID, nitrogen pressure 0.45 kg / cm ²・ Injection concentration 200 ° C., detector temperature 2
The temperature was set to 00 ° C., and the column temperature was raised from 50 ° C. at a rate of 5 ° C./1 minute for 30 minutes. -Preparation of calibration curve For a standard sample in which the target monomer is added to the same amount of DMF and acetone solution as the sample solution, perform gas chromatographic measurement in the same manner to obtain the weight ratio / area ratio of the monomer and the internal standard DMF.

Further, the resin used in the present invention has a melt viscosity η ′ of 120 ° C. to 150 ° C. by a hot elevated flow tester.
10 ³ to 10 ⁶ poi at any temperature in the temperature range of ° C.
When the natural logarithm lnη ′ of the melt viscosity at 150 ° C. is plotted against the temperature, the absolute value of the slope of the graph is 0.50 ln (poise) /
When the temperature is lower than or equal to ° C., the toner can be fixed on the recording material with lower power consumption without offsetting to the film.

The viscosity was measured using an elevated type flow tester (Shimadzu flow tester CFT-500 type) shown in FIG. 3, and about 1.5 g of a sample 33 molded using a pressure molding machine was plunged at a constant temperature. A load of 10 kgf was applied by 31 to push out from a nozzle 34 having a diameter of 1 mm and a length of 1 mm, and the plunger descent amount (flow velocity) of the flow tester was measured. The outflow rate is measured at each temperature (temperature range from 120 ° C. to 150 ° C. at 5 ° C. intervals), and from this value, the apparent viscosity η ′ can be determined by the following equation.

[0041]

(Equation 1) η ′: Apparent viscosity (poise) TW ′: Apparent shear reaction of tube wall (dyne / cm ² ) DW ′: Apparent shear rate of tube wall (1 / sec) Q: Outflow velocity (cm ³ / sec =) ml / sec) P: Extrusion pressure (dyne / cm ² ) [10 kgf = 980 × 10 ⁴ dyne] R: Nozzle radius (cm) L: Nozzle length (cm) Binder resin used in the toner of the present invention 120 ° C ~ 15
When the melt viscosity at 0 ° C. exceeds 10 ⁶ poise,
Also in the heat fixing method of the present invention, drawbacks such as an increase in power consumption, poor fixing and difficulty in quick start appear.

Conversely, the melt viscosity at 120 ° C. to 150 ° C. is 1
If it is less than 0 ³ poise, defects (set off, bleeding, etc.) due to excessive melting of the toner become remarkable.

The absolute value of the slope of the natural logarithm lnη 'of the melt viscosity η' at 120 ° C. and 150 ° C. with respect to the temperature reflects the sensitivity of the resin of the present invention to temperature change, and is 0.50 ln (poise) / If the temperature is higher than ℃, the film is easily offset, and the gloss of the fixed image is too high to lower the image quality.

The "inclination" of the viscosity in the present invention as is shown in FIG. 4, the measuring points at t _a ° C. in the graph, t
_Connect the measurement points at _b ° C with a straight line,

[0045]

(Equation 2) Is the value obtained by calculating the “slope”, which is approximated and used as the “slope” of the slope. (However, lnη _a '
Indicates a value obtained by taking a natural logarithm of viscosity at t _a ° C, and l
nη _b ′ indicates a value at t _b ° C. The resin composition of the toner of the present invention is preferably obtained by polymerizing one or more monomers selected from styrenes, acrylic acids, methacrylic acids and derivatives thereof from the viewpoint of developing characteristics and charging characteristics. Examples of monomers that can be used include styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene. Examples of acrylic acids, methacrylic acids and derivatives thereof include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-tetradecyl acrylate, and n-acrylate. Hexadecyl,
Examples include acrylates such as lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate, and the like. Similarly, methacrylic acid, methyl methacrylate ヽ ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid Amyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate And methacrylic esters such as dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate.
In addition to the aforementioned monomers, small amounts of other monomers such as acrylonitrile, 2-
Vinyl pyridine, 4-vinyl pyridine, vinyl carbazole, vinyl methyl ether, butadiene, isoprene, maleic anhydride, maleic acid, maleic monoesters, maleic diesters, vinyl acetate, and the like may be used.

As the crosslinking agent used in the resin for toner of the present invention, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-
Butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetra Ethylene glycol diacrylate, polyethylene glycol # 200, # 400, #
Examples include 600 diacrylates, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (MANDA Nippon Kayaku), and methacrylates of the above acrylates.

As polyfunctional crosslinking agents, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, Polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate,
Triallyl asocyanurate, triallyl isocyanurate, triallyl trimellitate, diarylchlorendate and the like.

In the toner using the resin of the present invention, in addition to the above-mentioned binder resin component, the following compound is contained in a proportion smaller than the content of the binder resin component so long as the effect of the present invention is not adversely affected. May be contained.

For example, silicone resin, polyester,
Polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin such as low molecular weight polyethylene or low molecular weight polypropylene, aromatic petroleum resin, chlorinated paraffin, For example, paraffin wax.

As the colorant contained in the toner 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.

When the toner according to the present invention is used as a magnetic toner, the contained magnetic fine particles include ferrite,
It does not contain metals made of ferromagnetic elements such as magnetite, iron, cobalt, nickel, etc., or alloys or compounds containing them, or ferromagnetic elements. Alloys such as manganese-copper-aluminum or manganese-copper-tin, such as an alloy of the type called Heusler alloy containing manganese and copper, chromium dioxide, and the like. The content ratio of the fine powder of these magnetic materials is
30 to 150 parts by weight is possible with respect to 100 parts by weight of the binder resin, and preferably 40 to 100 parts by weight. Further, the magnetic fine particles can also be used as a black or brown pigment.

[0052]

[0053]

Specific examples of the negative charge control agent contained in the toner according to the present invention include JP-B Nos. 41-20153, 42-27596, 44-6397, and 45-2.
Metal complexes of monoazo dyes described in JP-A-6478 and the like, and nitroamine acids and salts thereof described in JP-A-50-133338 or C.I. I. 1464
5, No. 5, No. 55-42752, No. 5
8-41508, JP-B-58-7384, JP-B-5
No. 9-7385, such as salicylic acid, naphthoic acid and dicarboxylic acids Zn, Al, Co, Cr and F
e, a metal complex such as e, a sulfonated copper phthalocyanine pigment, a nitro group, a styrene oligomer into which a halogen is introduced, and a chlorinated paraffin. In particular, from the viewpoint of dispersibility, a metal complex salt of a monoazo dye, and a metal complex of salicylic acid, alkyl salicylic acid, naphthoic acid, and dicarboxylic acid are preferable. The addition amount of these charge control agents minimizes adverse effects such as a reduction 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. Therefore, the addition amount is preferably 0.1 to 3 parts by weight based on 100 parts by weight of the binder resin.

As the toner fixing aid of the present invention, an ethylene olefin polymer may be used together with a binder resin.

Here, those applied as ethylene-based olefin homopolymer or ethylene-based olefin copolymer include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer. There is an ionomer having a polyethylene skeleton, or the like, and the above copolymer preferably contains 50 mol% or more (more preferably, 60 mol% or more) of an olefin monomer.

Next, an electrophotographic method using a developer using the resin according to the present invention will be described.

The step of developing the electric latent image using the toner includes the above-described magnetic brush method, cascade developing method, powder cloud method, and the conductive method described in US Pat. No. 3,909,258. Using a magnetic toner described in
There is a method using a high-resistance magnetic toner described in JP-A-31136. The toner using the resin according to the present invention is also suitable for a developing method using a so-called one-component developer containing magnetic particles. In the step of transferring the developed image to the transfer-receiving member, an electrostatic transfer method such as a corona transfer method or a method of applying a bias to the contact transfer member is used.

In recent years, methods such as charging and / or transfer and / or static elimination using corona discharge onto a photoreceptor from a member not in contact with the photoreceptor involve generation of ozone. A method of applying a bias directly through a contact member has attracted attention. With the shift to such a system, there has been a possibility that an activated carbon filter often attached to a conventional copier / printer may be removed. It has a remarkable effect.

Further, in the toner using the binder resin of the present invention, a blade cleaning system, a fur brush cleaning system, or the like is applied to the step of removing the residual toner on the photosensitive layer or the insulating layer. Suitable for cleaning system.

The basic configuration and features of the present invention have been described above. The method of the present invention will be specifically described below based on embodiments. However, this does not limit the embodiment of the present invention at all. Parts in the examples are parts by weight.

[0062]

EXAMPLE First, an example of synthesizing the resin used in this example will be described.

Synthesis Example 1 200 parts of cumene was charged into a reactor and heated to the reflux temperature. 100 parts of styrene monomer and di-ter
A mixture of 8 parts of t-butyl peroxide was added dropwise over 4 hours under cumene reflux. Furthermore, under cumene reflux (146 ° C
〜156 ° C.) to complete the polymerization and remove cumene.

30 parts of the obtained polystyrene was dissolved in the following monomer mixture to prepare a mixed solution.

[0065]

[Table 1] In the above mixed solution, partially saponified polyvinyl alcohol was added.
170 parts of water in which 1 part was dissolved was added to obtain a suspension dispersion.
Pour 15 parts of water and introduce nitrogen through a nitrogen introduction tube.
Nitrogen was flowed at a temperature of 45 ° C. so that the concentration of dissolved oxygen became 1.5 mg / l. In this state, the dispersion was added to the reactor, and a suspension polymerization reaction was performed at a reaction temperature of 70 to 95 ° C. for 9 hours. After the completion of the reaction, steam distillation was performed, followed by filtration, dehydration, and drying to obtain a composition of polystyrene and styrene-n-butyl acrylate copolymer. The residual monomer content of this composition was measured by gas chromatography and found to be 150 ppm.

Synthesis Example 2 200 parts of cumene were charged into a reactor and heated to the reflux temperature. The following mixture was added dropwise over 4 hours under cumene reflux.

[0067]

[Table 2] Further, the polymerization was completed under the reflux of cumene (146 to 156 ° C.) to remove cumene.

30 parts of the obtained styrene-α-methylstyrene copolymer was dissolved in the following monomer mixture to prepare a mixed solution.

[0069]

[Table 3] In the above mixed solution, partially saponified polyvinyl alcohol was added.
170 parts of water in which 1 part was dissolved was added to obtain a suspension dispersion. 15 parts of water was added, and the concentration of dissolved oxygen was set to 1.8 mg / l in the same manner as in Synthesis Example 1. Similarly, the above dispersion was added to the reactor and reacted at a reaction temperature of 70 to 95 ° C. for 9 hours.
After completion of the reaction, steam distillation, filtration, dehydration and drying were performed to obtain a composition of a styrene-α-methylstyrene copolymer and a styrene-2-ethylhexyl acrylate copolymer.

The composition had a residual monomer content of 200 pp
m.

Synthesis Example 3 200 parts of cumene were charged into a reactor and heated to a reflux temperature. The following mixture was added dropwise over 4 hours under cumene reflux.

[0072]

[Table 4] Further, the polymerization was completed under the reflux of cumene (146 to 156 ° C.) to remove cumene.

The obtained styrene-methyl methacrylate copolymer (40 parts) was dissolved in the following monomer mixture to prepare a mixed solution.

[0074]

[Table 5] In the above mixed solution, partially saponified polyvinyl alcohol was added.
170 parts of water in which 1 part was dissolved was added to obtain a suspension dispersion. 15 parts of water was added, and dissolved oxygen was adjusted to 1.8 in the same manner as in Synthesis Example 1.
mg / l. Similarly, the above dispersion was added to the reactor and reacted at a reaction temperature of 70 to 95 ° C. for 9 hours. After completion of the reaction, steam distillation, filtration, dehydration and drying were performed to obtain a composition of a styrene-methyl methacrylate copolymer and a styrene-n-butyl methacrylate copolymer. The residual monomer content of this composition was 240 ppm.

Synthesis Example 4

[0076]

[Table 6] To the above mixture, polyvinyl alcohol partially saponified 0.1
170 parts of water in which the above parts were dissolved was added to obtain a suspension dispersion. Water 1
5 parts, and dissolved oxygen 1.5 m in the same manner as in Synthesis Example 1.
g / l. Similarly, the above dispersion was added to the reactor and reacted at a reaction temperature of 70 to 95 ° C. for 9 hours. After completion of the reaction, steam distillation, filtration, dehydration and drying were performed to obtain a styrene-n-butyl acrylate copolymer composition. The residual monomer content of this composition was 320 ppm.

Next, an embodiment will be described.

[0078] Example compositions 100 parts of -1 Synthesis Example 1 (resin residual monomer = 150 ppm) magnetic fine powder (average particle diameter 0.3 micron) 100 parts negatively chargeable monoazo dye 1 part low molecular weight polypropylene 3 parts After mixing the above-mentioned raw materials, the mixture was hot-melt-kneaded at a kneaded material temperature of 200 ° C., cooled, pulverized and classified to obtain a classified magnetic fine particle having a volume average particle diameter of 7 μm. 0.9% of negatively chargeable colloidal silica was externally added to 100 parts of the classified magnetic fine particles to obtain a developer. The amount of residual monomer in this developer is 30 ppm
Met.

Next, the tester used in this embodiment will be described. In this embodiment, a printout test was performed using a fixing device of a commercially available laser beam printer LBP-SX (manufactured by Canon) having the following configuration.

In the heat fixing device of the present invention shown in FIG.
The temperature measuring element surface temperature T ₁ of the heating body 11 is 190 ° C., the power consumption of the resistance material of the heating unit is 150 W, the total pressure between the heating body 11 and the pressure roller 21 is 13 kg, the nip between the pressure roller and the film is 3 mm, The rotation speed of the fixing film 18 is 4
8 mm / sec (equivalent to LBP-SX machine manufactured by Canon Inc.).

As the heat-resistant sheet, 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 the contact surface with the recording material was used. At this time, it took about 3 seconds for the surface temperature T _{1 of the} heating element to reach 185 ° C. Further, the temperature T ₂ is 1
84 ° C. and the temperature T ₃ was 183 ° C.

Under the above setting conditions, 4 sheets (A3) / min
The actual printing test for forming a developer image by a reversal developing method over 2,000 sheets continuously at a printing speed of
C., 60% RH), high temperature and high humidity (30.degree. C., 90% RH) and low temperature and low humidity (15.degree. C., 10% RH), the printout image was evaluated, and at the same time, the state of the fixing film surface was observed. .

As a result, no defect on the image due to the damage of the film was observed in any of the environments up to 2,000 sheets. Further, no contamination or fixation by the developer occurred on the surface of the fixing film, and good durability was exhibited.

Example 2 Composition of Synthesis Example 2 100 parts (residual monomer amount = 320 ppm) Magnetic fine powder (average particle size 0.4 μm) 100 parts Negatively chargeable monoazo dye 1 part Low molecular weight polypropylene 3 parts The above raw materials Was mixed and hot-melt kneaded at a kneaded material temperature of 200 ° C. under a reduced pressure of 600 mmHg to prepare a developer in the same manner as in Example 1. The residual monomer amount in this developer was 30 ppm. When a print-out test was performed in each environment in the same manner as in Example 1, no image defect was observed on up to 2,000 sheets, and no change was observed on the film surface.

Example 3 Composition of Synthesis Example 3 100 parts (residual monomer content = 240 ppm) Magnetic fine powder (average particle size 0.4 μm) 100 parts Negatively chargeable monoazo dye 1 part Low molecular weight polypropylene 3 parts Was mixed and kneaded under a reduced pressure of 400 mmHg at a temperature of 200 ° C. by hot-melt kneading to prepare a developer in the same manner as in Example 1. The residual monomer amount in this developer was 70 ppm. When a printout test was performed in each environment in the same manner as in Example 1, no particular contamination was observed on the fixing film surface up to 1,500 sheets, and a good image could be obtained.

Example 4 90 parts of the composition of Synthesis Example 4 (residual monomer in resin = 320 ppm) Styrene-butadiene copolymer 10 parts (residual monomer in resin = 410 ppm) Magnetic fine powder (average particle diameter: 0) 0.3 μ) 100 parts Negatively chargeable monoazo dye 1 part Low molecular weight polypropylene 3 parts After mixing the above raw materials, a developer was prepared in the same manner as in Example 1. The amount of residual monomers in this developer is 150 ppm
Met.

Next, a continuous print-out test was performed using this developer in the same manner as in Example 1. As a result, no contamination of the surface of the fixing film due to the developer occurred up to 1,000 sheets, and a good image could be obtained. did it.

[0088]

As described above, according to the present invention, the surface of the fixing film is contaminated by the residual monomers in the developer, and further, the change in the surface properties of the sheet and the fixation of the residual developer are prevented. Thus, a fixing method with a short wait time and low power consumption was realized while achieving excellent fixing properties and stable images, and high durability was achieved.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an example of a fixing device for implementing a method of the present invention.

FIG. 2 is a structural diagram of another example of a fixing device for implementing the method of the present invention.

FIG. 3 is a schematic view showing an elevated flow tester used for measuring the outflow starting temperature and the melt viscosity according to the present invention.

FIG. 4 is a graph showing a relationship between a plunger descent amount and a temperature of the apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Low-heat-capacity linear heating element 12 Alumina substrate 13 Resistance material 14 Temperature measuring element 15 Fixing film 16 Drive roller 17 Follower roller 18 Rubber elastic layer 19 Transfer material 20 Unfixed developer 21 Inlet guide 22 Sheet feed shaft 23 Winding shaft 31 Plan Jar 32 Shilling 33 Sample 34 Nozzle 35 Nozzle holder

──────────────────────────────────────────────────続 き Continuing on the front page (72) The inventor, Manabu Ohno, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) The inventor, Hiroyuki Suematsu 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-3-122660 (JP, A) JP-A 1-219769 (JP, A) JP-A 1-193870 (JP, A) JP-A 64-70765 (JP, A) A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 9/08 G03G 15/20 101

Claims (4)

(57) [Claims] The visualized image of claim 1 developer, heating the recording material by the fixing supported heating member and the heating body opposite pressure and pressurizing adhering the film through the record material to the heating body material Is a fixing method for fixing , the film and the visible image
Contact surface of polytetrafluoroethylene with conductive material
Endless polyimide film having a release layer in which
A developer used in a fixing method using a film, wherein the developer contains a binder resin, a colorant, and a negative charge control agent.
Negatively chargeable developer with residual monomer content of 150 ppm or less
A developer for heat fixing, characterized by being a developer. 2. The method according to claim 1, wherein the negatively chargeable developer is a low molecular weight polypropylene.
2. The composition according to claim 1, wherein the composition contains pyrene.
Heat fixing developer. A developed image wherein a developer, heating the recording material by the fixing supported heating member and the heating body opposite pressure and pressurizing adhering the film through the record material to the heating body material Is a fixing method for fixing , the film and the visible image
Contact surface of polytetrafluoroethylene with conductive material
Endless polyimide film having a release layer in which
In the fixing method using a film, the developer used is a binder resin, a colorant, and a negative charge control.
Band containing an agent and the amount of residual monomer is 150 ppm or less
A heat fixing method, wherein the heat fixing method is an electric developer . 4. The method according to claim 1, wherein the negatively chargeable developer is a low molecular weight polypropylene.
4. The composition according to claim 3, comprising pyrene.
Heat fixing method.