JPH0812454B2 - Heat fixing method and heat fixing capsule toner used in the method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fixing method and toner used in electrophotography, electrostatic printing, magnetic recording, etc., and more particularly, to fixing a toner image on a recording material by heating. And a capsule toner used in the fixing method of the image forming apparatus.

[Prior Art] Conventionally, as a method for fixing a visible image of a toner on a recording material, it is undetermined by using a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and being in pressure contact with the heating roller. A heat roll fixing method is often used in which a recording material holding a visible toner image is heated while being nipped and conveyed.

Further, a belt fixing method described in USP 3,578,797 is known.

[Problems to be Solved by the Invention] However, in the above-described thermal roll fixing which has been frequently used, there is (1) a time for which the image forming operation is prohibited until the heat roller reaches a predetermined temperature, that is, a so-called wait time.

(2) In order to prevent fixing failure and transfer of toner to the heating roller due to the temperature of the heating roller fluctuating due to passage of the recording material or other external factors, so-called offset phenomenon, the heating roller is set to an optimum temperature. It is necessary to maintain this, and for this purpose, the heat capacity of the heating roller or the heating body must be increased, which requires a large amount of electric power.

(3) Since the temperature of the roller is low, when the recording material passes through the heating roller and is discharged, the recording material and the toner on the recording material are cooled slowly, so that the toner has a high adhesiveness. In combination with the curvature of, the paper may be jammed due to the offset or winding of the recording material.

(4) Since the high-temperature heating roller is in direct contact with the hand, there is a problem in safety or a protective member is required. Also, in the belt fixing method described in USP 3,578,797, the problems (1) and (2) of the heat roll fixing described above have not been fundamentally solved.

An object of the present invention is to substantially eliminate the wait time for solving the above-mentioned problems, or an extremely short time,
Further, the present invention provides a novel heating and fixing method which has low power consumption, does not cause an offset phenomenon, and is excellent in fixing a toner image on a recording material.

Further, an 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.

Still another object of the present invention is to provide a heat fixing method that does not require a heat resistant special bearing by not using a high temperature rotating roller.

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 in which the high temperature body is not directly touched.

[Means for Solving the Problem] Specifically, the present invention uses a capsule toner in which the surface of core particles mainly composed of a binder resin and a colorant is coated with a resin, and a visible image of the capsule toner is recorded. In the method of heating and fixing to a material, a) the viscosity of the binder resin at 50% outflow point measured by an elevated flow tester is in the range of 10 ³ to 10 ⁵ poise, and the viscosity at 50% outflow point is natural. When the logarithm is plotted against temperature, the absolute value of the slope of the graph is 1.0ln
(Poise) / ° C. or less is used, and b) a fixedly supported heating element, and a pressure for contacting the heating element with the recording material and facing the heating element through a fixing film. The surface temperature T ₃ of the fixing film in the portion where the visible image of the capsule toner is heated and fixed on the recording material by the member, and c) is higher than the endothermic temperature T _{D of the} capsule toner.
The present invention relates to a heat fixing method, which comprises peeling the fixing film from the toner fixing surface under the condition of having a high temperature of 30 ° C. or higher.

Further, according to the present invention, a visualized image of a capsule toner is applied to a recording material by a fixedly supported heating element and a pressing member that is in pressure contact with the heating element and brings the recording material into close contact with the heating element via a fixing film. When the surface temperature T ₃ of the fixing film in the portion which is heat-fixed and peels off from the toner fixing surface is 30 ° C. or more higher than the endothermic temperature T _D of the capsule toner, the fixing film is fixed on the toner fixing surface. A capsule toner used in a fixing method of peeling from a core, wherein the capsule toner has a core particle surface mainly composed of a binder resin and a colorant coated with a resin,
50% of the binder resin measured by an elevated flow tester
The viscosity at the pour point is in the range of 10 ³ to 10 ⁵ poise,
The absolute value of the slope of the graph when the natural logarithm of the viscosity at 50% pour point is plotted against temperature is 1.0 ln (pois
e) A heat-fixing capsule toner having a characteristic of not higher than / ° C.

In Japanese Patent Application Laid-Open No. 62-147884 previously provided by the present applicant, a toner image is heated through a moving heat-resistant sheet by a heating element having a low heat capacity that is energized and heated in a pulse shape, and is fixed on a recording material. An image forming apparatus having a short wait time and low power consumption has been proposed as the fixing device. Similarly, Japanese Patent Application No. 63-1206 previously proposed by the applicant.
In 9, in the fixing device for heating and fixing the visible image of the toner on the recording material via the heat resistant sheet, the heat resistant sheet has a heat resistant layer and a release layer or a low resistance layer,
A fixing device has been proposed that effectively prevents the offset phenomenon.

However, in order to realize a fixing method that has a short wait time and low power consumption while achieving excellent fixability of a toner image on a recording material, prevention of offset, etc., the fixing device as described above is used. In addition, the characteristics of the toner largely depend.

The viscosity of the binder resin in the present invention is measured by an elevated flow tester (Shimadzu flow tester CFT as shown in FIG.
-500 type). A sample of 1.5 g molded with a pressure molding machine was pressed by a plunger at a constant temperature of 10 kgf.
It is made to push out from a nozzle with a diameter of 1 mm and a length of 1 mm, and the plunger drop amount (flow rate) of the flow tester is measured by this.

This outflow rate is measured at each temperature (interval of 2.5 ° C), and the apparent viscosity η'can be obtained from this value by the following equation.

However, η ′: Apparent viscosity (poise) Tω ′: Apparent shear reaction of tube wall (dyne / cm ² ) Dω ′: Apparent shear rate of tube wall (1 / sec) Q: Outflow rate (cm ³ / sec = ml / sec) P: Extrusion pressure (dyne / cm ² ) [10kgf = 980 × 10 ⁴ dyn
e] R: Nozzle radius (cm) [0.1 cm] L: Nozzle length (cm) [0.1 cm] Plot the natural logarithm of the apparent viscosity η'obtained from the flow tester against temperature (° C) Then, the slope at the temperature of the 50% pour point was calculated. The 50% outflow point is
Performed by the flow tester, heating the sample at a temperature rising rate of 4 ° C / m
It is the temperature at the time when the load of 10 kgf is applied while heating at in, and the outflow amount from the nozzle becomes 50 wt%.

In the present invention, the “slope” of the viscosity at the 50% pour point means, as shown in FIG. 5, the measurement points (t _c and t _d ) of the melt viscosity that sandwich the temperature (t ₅₀ ) at the 50% pour point. Connect the plots at the outer measurement points (t _a and t _b ) with a straight line, It is calculated from the above, and this is approximated and used as the “slope” of the slope. (However lnη _'a represents a value obtained by taking the natural logarithm of the viscosity at _{t a (℃), lnη'} b denotes a value at t _b (° C.). The measurement was measured 5 ° C. intervals.) The present invention The "viscosity" and "inclination" of the binder resin in the heat fixing method of 1 are peculiar to each binder resin,
It shows the sensitivity of the viscosity of the binder resin to temperature, and is involved in the binder property and toner particle deformation during the formation of a fixed image. Particularly in the fixing method using a film, the correlation with the fixing process is great. When the melt viscosity is high (10 ⁵ p
Oise or higher) causes less fixing due to less particle deformation during heat fixing and does not increase adhesiveness, and a large amount of energy is required to compensate for this. On the other hand, if it is low (10 ³ poise or more), bleeding on the transfer paper or
Penetration into the transfer paper is likely to occur. Also, the "tilt" is
If 1.0 ln (poise) / ° C becomes too large, the particles are sensitive to temperature and exhibit a rapid change in viscosity, so that the latitude of the fixing temperature cannot be sufficiently taken, and fixing failure or penetration is likely to occur. Furthermore, the dependency on the fixing processing speed (mm / sec) becomes large. Further, this "tilt" is also involved in the viscosity change during cooling after melting of particles during fixing, and when the "tilt" is large, the offset phenomenon to the film increases.

The toner used in the heat fixing method of the present invention is a microcapsule type toner. Generally, a microcapsule type toner has a form in which a core material containing a binder resin, a colorant and the like is coated with a shell material, and the uniform shell material coating has excellent fluidity and charging characteristics. In addition, since it is protected by the shell material, it has excellent blocking properties and storage stability, and it is possible to add a substance that softens at a lower temperature to the core material, which improves the fixing property and further improves the substantial fixing temperature. It is possible to lower it.

As the binder resin material used for the core material of the capsule toner of the present invention, various known resins can be used alone or mixed or reacted so as to have the melt viscosity characteristic of the present invention. For example, polystyrene and its substituted homopolymers: styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, Styrene-based copolymers such as styrene-acrylonitrile-indene copolymer: acrylic resin, methacrylic resin, silicone resin,
Examples include polyester resin, furan resin, epoxy resin, and the like.

Further, a binder material for pressure fixing or low temperature fixing can also be used. For example, waxes (beeswax, carnauba 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 hydroxy stearate, glycerol monohydroxy stearate, etc.),
Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polyisobutylene, polytetrafluoroethylene, etc.), olefin copolymer, (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacryl) Acid copolymers, ethylene-methacrylic acid ester copolymers, ethylene-vinyl chloride copolymers, ethylene-vinyl acetate copolymers, ionomer resins, etc.), rubbers (isobutylene rubber, nitrile rubber, chlorinated rubbers, etc.), polyvinyl There are pyrrolidone, polyamide, coumarone-indene resin, methyl vinyl ether-maleic anhydride copolymer, maleic acid modified phenol resin, phenol modified terpene resin, etc.,
These may be used alone, mixed, or reacted.

Further, in the core material of the capsule toner of the present invention, in general,
Various dyes and pigments are included as colorants. Examples of such dyes and pigments include carbon black, nigrosine dye, lamp black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgadine Red, Paranitroaniline. Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Resor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Red. Green B, Phthalocyanine Green, Oil Yellow GG, Zapon First Yellow CGG, Kayaset Y963, Kayaset YG, Sumiplast Yellow GG, Zapon First Orange RR, Oil Scarlet, Sumipras Orange G, the colorant Orasol Brown B, The Pont Fast Scarlet CG, Aizenspilon Red · BEH, such as oil pink OP can be applied.

Further, in order to use the toner as a magnetic toner, magnetic powder may be contained in the core material. As such magnetic powder, a substance that is magnetized when placed in a magnetic field is used, and is a powder of a ferromagnetic metal such as iron, cobalt, or nickel.
Alternatively, there are alloys and compounds such as magnetite, hematite, and ferrite. The content of the magnetic powder is preferably from 15 to 70% by weight based on the weight of the toner.

In the microcapsule toner used in the present invention, a releasable substance may be contained in either or both of the core material and the shell material, if necessary. Examples of such a release agent include polyfluoroethylene, fluororesin, fluorinated carbon oil, silicone oil, low molecular weight polyethylene, low molecular weight polypropylene, etc., and the content is contained in the core material or the shell material. The amount used varies depending on the amount of the toner used, but usually it is preferably 0.1 to 50% by weight, more preferably 0.5 to 20% by weight, based on the toner.

The core material of the encapsulated toner of the present invention can be obtained by melt-kneading the above components with, for example, a roll mill, pulverizing with a jet mill or the like, and, if necessary, classifying with an air classifier. Furthermore, after the particles are melt-kneaded, they are granulated by a spray method, a suspension granulation method, an electrostatic atomization method, or the like, and classified as necessary, whereby fine particles having a volume average particle diameter of 20 μm or less are prepared.

As a method for encapsulating these core particles, a known encapsulation technique can be used. For example, a dry capsule method in which the shell material is immobilized on the surface of the core material by utilizing mechanical impact force, a spray dry method, a coacervation method, a phase separation method, and the like can be preferably used, in-situ polymerization method, The methods described in US Pat. Nos. 3,338,991, 3,326,848, and 3,502,582 can also be used.

A known resin can be used as the shell material. For example, there are resins composed of the following monomers. Styrene such as styrene, p-chlorostyrene, and p-dimethylamino-styrene, and substituted products thereof; methyl acrylate,
Ester of acrylic acid or methacrylic acid such as ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid N, N-dimethylaminoethyl ester; maleic anhydride or half ester of maleic anhydride , Half amide or diester imide, vinyl pyridine, N
-Nitrogen-containing vinyl such as vinyl imidazole; vinyl acetals such as vinyl formal and vinyl butyral; vinyl monomers such as vinyl chloride, acrylonitrile, vinyl acetate; vinylidene monomers such as vinylidene chloride and vinylidene fluoride; olefin monomers such as ethylene and propylene. is there. Also, polyester, polycarbonate, polysulfonate, polyamide, polyurethane, polyurea, epoxy resin, rosin, modified rosin,
Homopolymers or copolymers of terpene resins, phenol resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, melamine resins, polyether resins such as polyphenylene oxide or thioether resins, or copolymers, and further Mixtures thereof can be used.

In some cases, the capsule toner of the present invention can be used as a developer after mixing with a fluidity improver such as colloidal silica, or a lubricant, an abrasive, a charge control agent and the like.

When used as a two-component developer, it is used as a developer after being mixed with an iron powder carrier, a ferrite carrier, a carrier obtained by coating these with a silicone resin, an acrylic resin or the like, or a carrier having a magnetic material dispersed in a resin. .

 Next, the fixing method of the present invention will be described.

First, a schematic structure of an example of the image forming apparatus of the present invention will be described below.
It will be described with reference to the drawings. Reference numeral 1 denotes an original placing table made of a transparent member such as glass, which reciprocates in the direction of arrow a to scan the original. Immediately below the document table, a short-focus small-diameter imaging element array 2
The document image placed on the document table is illuminated by the certification lamp 3, and the reflected light image is slit-exposed on the photosensitive drum 4 by the array 2. The photosensitive drum rotates in the direction of arrow b. Reference numeral 5 denotes a charger, which uniformly charges the photosensitive drum 4 covered with, for example, a zinc oxide photosensitive layer or an organic semiconductor photosensitive layer. The drum 4 uniformly charged by the charger 5 is
The element array 2 forms an electrostatic image subjected to image exposure. This electrostatic latent image is visualized by the developing device 6 by using a toner made of a resin or the like which is softened and melted by heating. On the other hand, the sheets P stored in the cassette S are
It is fed onto the drum 4 by a pair of conveying rollers 8 which are rotated in pressure contact with each other in the vertical direction at a timing synchronized with the feeding roller 7 and the image on the photosensitive drum 4. Then, the transfer discharger 9 transfers the toner image formed on the photosensitive drum 4 onto the sheet P. afterwards,
The sheet P separated from the drum 4 by a known separation unit is guided to the fixing device 11 by the conveyance guide 10 and is heated and fixed, and then discharged onto the tray 12. After the toner image is transferred, the residual toner on the drum 4 is removed by the cleaner 13.

FIG. 3 (a) shows an enlarged view of the fixing device 11 of the present invention.
Reference numeral 20 denotes a low-heat-capacity linear heating element that is fixedly supported by the apparatus, and as an example, an alumina substrate 21 having a thickness of 1.0 mm, a width of 10 mm, and a longitudinal length of 240 mm is coated with a resistance material 22 in a width of 1.0 mm. Power is applied from both ends. Energization is a pulsed waveform with a cycle of 20 msec of DC 100 V and is given by varying the pulse width according to a desired temperature and energy release amount controlled by the temperature measuring element 23. Approximate pulse width is 0.5 msec to 5 ms
It becomes ec. When the temperature detected by the temperature measuring element 23 in the low heat capacity linear heating element 20 is T ₁ , the surface temperature T ₂ of the film 24 facing the resistance material 22 is lower than T ₁ by about 10 to 30 ° C. The film surface temperature T _{3 at} the portion where the film 24 is peeled off from the toner fixing surface is substantially equal to the temperature T ₂ .

In this way, the fixing film 24 moves in the direction of the arrow in the drawing by coming into contact with the heating body 20 whose energy and temperature are controlled. As an example of this fixing film, a heat-resistant film with a thickness of 20 μm,
For example, it is an endless film obtained by coating a release layer of polyimide, polyetherimide, PES, PFA with a conductive material added to a fluororesin such as PTFE, PAF or the like on at least the image contact surface side to a thickness of 10 μm. Generally, the total thickness is 100μ, preferably 40μ
Less than, film drive is driven roller 25 and driven roller 26
It moves without wrinkles in the direction of the arrow by the drive and tension.

Reference numeral 27 is a pressure roller having a rubber elastic layer having a good releasability such as silicon rubber, which presses a heating body through the film at a total pressure of 4 to 20 kg to rotate in pressure contact with the film.

The unfixed toner 29 on the transfer material 28 is guided to the fixing portion by the entrance guide 30 and obtains a fixed image by the above-mentioned heating.

The endless belt has been described above, but as shown in FIG. 3 (b), a sheet feeding shaft 31 and a winding shaft 32 may be used, and the fixing film may be an end film 24.

Image forming devices include copiers, printers and fax machines.
This is applicable to all fixing devices that form an image using toner such as.

In the heat fixing method of the present invention, the toner used has a maximum value of the endothermic peak that appears first as measured by DSC in the measurement range from 10 ° C to 200 ° C from 40 ° C to 12 ° C.
A toner having a temperature of 0 ° C. is preferable, and a toner having a characteristic of 55 ° C. to 100 ° C. is particularly preferable.

Further, the temperature at the time of peeling the film from the toner fixing surface is preferably higher than the endothermic temperature, more preferably 30 ° C. or more (more preferably 40 to 150 ° C.) higher than the endothermic temperature. It is preferable to peel under the conditions.

When the surface temperature T ₃ of the fixing film is lower than the endothermic temperature T _D + 30 ° C. of the capsule toner, it becomes difficult to peel the fixing film from the toner fixing surface smoothly, and therefore the surface condition of the toner fixing surface is The non-uniformity is likely to occur, and the adhesion between the back surface of the fixing film and the toner fixing surface is increased, so that defective separation of the recording material from the fixing film is likely to occur.

The maximum value of the endothermic peak in the present invention is calculated according to ASTM D-3418-82. In particular,
10 to 15 mg of toner is sampled from room temperature to 200 ° C under a nitrogen atmosphere.
After heating at a heating rate of 10 ° C / min to 200 ° C for 10 minutes, and then rapidly cooling the toner to pretreat it in advance, then holding it again at 10 ° C for 10 minutes, then 10 ° C. / m
Measure up to 200 ℃ at a heating rate of in. In general,
The data shown in FIG. 4 is obtained, and the maximum value of the endothermic peak that appears first is defined as the endothermic temperature (T _D ) in the present invention.

[Example] Hereinafter, the number of parts means parts by weight.

<Example 1> (1) Manufacturing method of developer Styrene 75 parts Butyl acrylate 25 parts 2,2'-azobis-2,4 dimethylvaleronitrile 4 parts Polyvinyl alcohol partially saponified product 0.1 to the above mixture.
200 parts of water in which 1 part was dissolved was added to give a suspension dispersion. 20 parts of water was added, and the above suspension dispersion was added to a reactor purged with nitrogen, and a suspension polymerization reaction was carried out at a reaction temperature of 80 ° C. for 10 hours. Then, the mixture was separated, dehydrated and dried to obtain a styrene-butyl acrylate copolymer composition.

The 50% pour point of the resin is 155 ° C., the viscosity at this time is 5.2 × 10 ³ poise, and the logarithm of the viscosity and the 50
The absolute value of the slope at the% discharge point is 0.075ln (poise) / ℃
Met.

55 parts of magnetic material and 10 parts of carbon black are premixed with 100 parts of the above resin in a Henschel mixer, and then 140 ° C.
It was kneaded for 30 minutes by a roll mill whose temperature was adjusted to. The kneaded product was cooled, roughly crushed with a cutter mill, and then crushed with a fine crusher using a jet stream. Further, classification was performed using an air classifier to obtain core particles having a volume average of 11.0 μm.

The above core particles were added to 100 parts of an emulsified dispersion liquid of dimethylaminoethyl methacrylate (solid content: 10% by weight), sufficiently dispersed, and then spray-dried at an inlet temperature of 180 ° C and an outlet temperature of 60 ° C to obtain a capsule toner powder. . 0.5% by weight of amino-modified silicon oil-treated silica was externally added to this to obtain a developer.

(2) Setting of fixing device In the heat fixing device of the present invention shown in FIG. 3A, the temperature of the heating element 20 is adjusted to 200 ° C., the rotation speed of the fixing film 24 is 50 mm / sec, and the heating element 20 is The total pressure between the pressure rollers 25 is
Adjusted to be 6kg.

(3) Evaluation An unfixed image of the above-mentioned developer was obtained using a modified machine of the commercially available Canon Copier FC-5 with the fixing device removed, and further a fixed image was obtained by the above fixing device.

In the fixing test of the fixed image, 200 unfixed images are continuously fed to obtain a fixed image, and the 1,10,50,100,200th sheet is rubbed with a symbol paper with a load of 50 g / cm ² before and after rubbing. The image density reduction rate (%) was expressed. In the offset resistance test, an unfixed image was continuously fixed, and the number of fixings was used to evaluate whether the fixed image or the fixing film was stained.

As a result, the fixability was almost constant even at the beginning of the 200th sheet and the 200th sheet, and was good at 1 to 3%. Regarding the offset resistance, almost no toner adhesion was observed on the surfaces of the fixing film 24 and the pressure roller 25 even after passing 10,000 sheets. Also, the fixed image did not show any stain, and neither set-off nor image blurring was seen.

On the other hand, the temperature of the heating element 20 can be fixed from room temperature (20 ° C) (200
The time required to raise the temperature to ℃), the so-called wait time, was 1.5 seconds.

<Comparative Example 1> Using the toner shown in Example 1, a fixing test was conducted by continuously passing 200 sheets of paper using a modified machine of Canon Copier FC-5 without the fixing roller cleaning mechanism. The fixability was slightly inferior with a density reduction rate of 8 to 10%. Also, in the offset resistance test, the number of sheets was 5,000, and the fixing roller had stains, which was clearly inferior.

On the other hand, the wait time was 20 seconds, which was 13 times as long as in Example 1.

<Example 2> Styrene 85 parts 2-Ethylhexyl acrylate 14.5 parts Divinylbenzene 0.5 parts Azobisisobutyronitrile 3 parts Polyvinyl alcohol partially saponified product 0.1 to the above mixture.
200 parts of water in which 1 part was dissolved was added to give a suspension dispersion. Add 20 parts of water and add the above suspension dispersion to a nitrogen-substituted reactor,
A suspension polymerization reaction was carried out at a reaction temperature of 80 ° C. for 12 hours. Then, the mixture was separated, dehydrated and dried to obtain a copolymer composition of styrene-2 ethylhexyl acrylate.

The 50% pour point of the resin was 145 ° C., the viscosity at this time was 7.1 × 10 ³ poise, and the logarithm of the viscosity was 50% of the temperature graph.
The absolute value of the slope at the% pour point was 0.1 ln (poise) / ° C.

60 parts of magnetic material was premixed with 100 parts of the above resin with a Henschel mixer, and then 20 with a roll mill adjusted to 130 ° C.
Kneaded for minutes. The kneaded material is crushed and classified to have a volume average of 11.5μ.
m core particles were obtained.

The above core particles were added to 100 parts of an emulsified dispersion of dimethylaminoethyl methacrylate (solid content: 10% by weight) and sufficiently dispersed, and then spray-dried at an inlet temperature of 180 ° C and an outlet temperature of 50 ° C to obtain a capsule toner powder. . 0.5% by weight of amino-modified silicon oil-treated silica was externally added to this to obtain a developer.

In the heat fixing device of the present invention shown in FIG. 3A, the temperature of the heating body 20 is adjusted to 180 ° C., the rotation speed of the fixing film 24 is 100 mm / sec, and the total distance between the heating body 20 and the pressure roller 25 is set. Pressure 1
Adjusted to be 0kg.

An unfixed image of the above developer was obtained using a remodeling machine of the commercially available Canon copying machine NP-1215 with the fixing device removed, and further a fixed image was obtained by the above fixing device.

When the same fixing test and offset resistance test as in Example 1 were carried out, the fixing property was as good as 2 to 4%, and the offset resistance was also good up to 10,000 sheets.

 The power consumption of the fixing device was 250W.

<Comparative Example 2> Using the toner shown in Example 2, a fixing test was conducted with a commercially available Canon copying machine NP-1215. The fixability was 2 to 4%, but at this time, the power consumption of the fixing device was 850 W, which was 3.4 times the power consumption of the fixing device of Example 2.

Example 3 50% pour point 97.5 ° C., viscosity at this time 1.1 × 10 ⁴ poise,
Also, kneading was performed by adding 5 parts of a monoazo red pigment to 100 parts of a polyester resin having an absolute value of a slope of 0.15 ln (poise) / ° C at a 50% outflow point of a graph of logarithm of viscosity and temperature,
The particles were pulverized and classified to obtain core particles having a volume average of 11.0μ.

The above core material was added to 100 parts of an emulsified dispersion of dimethylaminoethyl methacrylate (solid content: 10% by weight) and sufficiently dispersed, and then spray-dried at an inlet temperature of 150 ° C and an outlet temperature of 30 ° C to obtain a capsule toner powder. . 0.5% by weight of amino-modified silicon oil-treated silica was externally added to this to obtain a developer. Further, 100 parts of a ferrite carrier whose surface was coated with a fluorine-acrylic resin and 10 parts of the toner were mixed to prepare a starting agent.

In the heat fixing device of the present invention shown in FIG. 3 (a), the temperature of the heating body 20 is adjusted to 140 ° C., the rotation speed of the fixing film 24 is 50 mm / sec, the total pressure between the heating body 20 and the pressure roller 25. 6 kg
I adjusted it so that.

An unfixed image of the above developer was obtained using a modified machine of the commercially available Canon Copier FC-5 with the fixing device removed, and then a fixed image was obtained with the above fixing device.

When the same fixing test and offset resistance test as in Example 1 were carried out, the fixing property was good at 4 to 6%, and the offset resistance was no problem up to 10,000 sheets. The power consumption of the fixing device was 200W.

<Comparative Example 3> Using the toner shown in Example 3, a commercially available Canon copying machine FC-5 was used, and the power consumption of the fixing device was 200 W, which is equivalent to that in Example 3.
And a fixing test was performed. At this time, the temperature of the heating roller was 50 ° C., and the density decrease rate was over 80%, which was not practical.

Example 4 Polyethylene 70 parts Paraffin wax 30 parts The above mixture was melt-kneaded and then cooled to obtain a composition. The 50% pour point of the resin is 63 ° C., the viscosity at this time is 2.2 × 10 ⁴ poise, and the logarithm of the viscosity and 50
The absolute value of the slope at the% outflow point is 0.91ln (poise) / ℃
Met.

100 parts of the above resin, 70 parts of magnetic material, 3 carbon black
Parts were added and melt-kneaded. 20 g of colloidal silica is dispersed in 20 liters of water kept at 90 ° C, and 1 kg of the above melt-kneaded product is placed in this.
Was charged and granulated for 15 minutes with an Ajihomomixer (8000 rpm). After cooling and removing the silica with an alkaline solution,
After drying and classification, core particles having an average particle size of 11.0μ were obtained. The above core particles were added to 100 parts of an emulsified dispersion of dimethylaminoethyl methacrylate (solid content: 10% by weight) and sufficiently dispersed, followed by spray drying at an inlet temperature of 75 ° C and an outlet temperature of 20 ° C. Capsule toner powder was obtained. 0.5% by weight of amino-modified silicon oil-treated silica was externally added to this to obtain a developer.

In the heat fixing device of the present invention shown in FIG. 3 (a),
The temperature of the heating element 20 is adjusted to 100 ° C., the rotation speed of the fixing film 24 is 50 mm / sec, the total pressure between the heating element 20 and the pressure roller 25 is 10 mm.
Adjusted to be kg.

An unfixed image of the above developer was obtained using a modified machine of the commercially available Canon Copier FC-5 with the fixing device removed, and then a fixed image was obtained with the above fixing device.

When the same fixing test and offset resistance test as in Example 1 were carried out, the fixing property was good at 4 to 6%, and the offset resistance was no problem up to 10,000 sheets.

<Comparative Example 4> Using the toner shown in Example 4, a fixing test and an offset resistance test were conducted with a commercially available Canon copying machine FC-5.
The fixability was 6 to 8%, but there was a problem in practical use because stains were generated on the heating roller from 4000 sheets.

The endothermic temperature (T _D ), heating body temperature (T ₁ ), film surface temperature (T ₂ ), and film surface temperature (T ₃ ) at the time of peeling by the DSC of the toner sample shown in the examples of the present invention are shown in Table 1.
Shown in

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an elevated flow tester for measuring the melt viscosity of a toner or a binder resin, and FIG. 2 is an image forming apparatus equipped with a fixing device for carrying out the fixing method of the present invention. FIG. 3 (a) is a schematic sectional view of the fixing device for carrying out the fixing method of the present invention, and FIG. 3 (b) is a fixing method of another embodiment of the present invention. FIG. 3 shows a schematic cross-sectional view of a fixing device for carrying out the above. FIG. 4 is a graph showing the endothermic peak of the toner, and FIG. 5 is a graph showing the slope of the natural logarithm of the viscosity of the toner or the binder resin with respect to temperature.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location G03G 13/20 15/20 101 (72) Inventor Satoshi Matsunaga 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc. (56) Reference JP-A-59-68766 (JP, A) JP-A-59-157678 (JP, A) JP-A-63-128362 (JP, A) JP-A-63-128360 (JP, A) JP 63-128361 (JP, A) JP 63-128357 (JP, A) JP 61-215558 (JP, A) JP 61-215557 (JP, A) Kai 63-58356 (JP, A)

Claims (4)

[Claims] 1. A method of heat-fixing a visible image of a capsule toner to a recording material using a capsule toner having a core particle surface containing a binder resin and a colorant as a main component coated with a resin, comprising: a) the binder The viscosity of the resin at 50% pour point measured by an elevated flow tester is in the range of 10 ³ to 10 ⁵ poise, and the natural logarithm of the viscosity at 50% pour point is plotted against temperature. The absolute value of 1.0ln
(Poise) / ° C. or less is used, and b) a fixedly supported heating element, and a pressure for contacting the heating element with the recording material and facing the heating element through a fixing film. The surface temperature T ₃ of the fixing film in the portion where the visible image of the capsule toner is heated and fixed on the recording material by the member, and c) is higher than the endothermic temperature T _{D of the} capsule toner.
A heating and fixing method, characterized in that the fixing film is peeled from the toner fixing surface under the condition of having a high temperature of 30 ° C. or higher. 2. The heat fixing method according to claim 1, wherein the fixing film is a heat resistant film having a release layer on the toner fixing surface side. 3. The heating element is a linear heating element having a temperature measuring element and a resistance material in the length direction, and while heating the temperature by the temperature measuring element, energization of a pulse waveform is applied to the resistance material to heat the heating element. The heat fixing method according to claim 1, wherein the body is heated. 4. A visible image of capsule toner is heated on a recording material by a fixedly supported heating element and a pressing member that is in pressure contact with the heating element and presses the recording material in close contact with the heating element via a fixing film. In the state where the surface temperature T ₃ of the fixing film in the portion which is fixed and peeled off from the toner fixing surface is higher than the endothermic temperature T _D of the capsule toner by 30 ° C. or more,
A capsule toner used in a fixing method of peeling the fixing film from a toner fixing surface, wherein the capsule toner is a capsule toner in which a core particle surface containing a binder resin and a colorant as a main component is coated with a resin, The viscosity of the binder resin at 50% pour point measured by an elevated flow tester is in the range of 10 ³ to 10 ⁵ poise, and the natural logarithm of the viscosity at 50% pour point is plotted against temperature. The absolute value of the slope of the graph is 1.0ln (poise)
A heat-fixing capsule toner having a characteristic of not higher than / ° C.