JPH06175455A - Color electrophotographic device - Google Patents

Abstract

(57) [Summary] [Object] To provide a color electrophotographic apparatus having a long toner life, excellent storage stability, good offset resistance, and good image smoothness. An electrostatic latent image is formed on a photoconductive insulator layer, a toner image is formed from the electrostatic latent image, the toner image is transferred onto a recording paper, and the toner is heated and melted, An apparatus for performing electrophotographic recording by fixing the toner on the recording paper, wherein the toner has a storage elastic modulus at 150 ° C. of 5 × 10 ² to 10 ⁴ dyn / cm ² and a loss elastic modulus of 10 ³ to A color toner of 10 ⁴ dyn / cm ² is used, and a cooling roll for fixing the toner on the recording paper by rapidly cooling the toner after heating and melting is provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a color electrophotographic apparatus useful for color electrophotographic printing or copying. The present invention particularly relates to a color electrophotographic apparatus capable of obtaining a fixed image having a long life of a color developer, good offset resistance and excellent smoothness.

[0002]

2. Description of the Related Art The electrophotographic method adopted in a copying machine or a laser printer generally gives a uniform electrostatic charge on a photoconductive insulating layer and irradiates a light image on the insulating layer. By doing so, the electrostatic charge is partially removed to form an electrostatic latent image, and fine powder called toner is attached to the portion where the electrostatic charge remains to form a toner image in which the electrostatic latent image is visualized ( Then, this toner image is transferred onto recording paper and fixed (called fixing) to obtain a printed matter.

[0003]

In the case of color printing, if the image surface on which the toner is fixed has large irregularities, there is a problem in that a highly saturated image cannot be obtained due to the influence of diffused reflection on the image surface. In particular, in a color overhead projector (OHP), the smoothness of the image surface is important, and if it is uneven, a highly saturated image cannot be obtained due to irregular reflection of light. Thus, the smoothness of the image surface is particularly important for color printing.

The fixing methods that greatly affect the smoothness of the image surface are roughly classified into pressure fixing and
There are four types of heat roll fixing, flash fixing, and oven fixing, each with their own characteristics. Since the pressure fixing crushes the toner with a high pressure and fixes it on the paper surface, it has excellent image smoothness, but has disadvantages such as poor fixability and poor storage stability of the toner. In addition, heat roll fixing, flash fixing, and oven fixing have excellent fixability because the toner is melted and fixed on the paper surface, but flash fixing and oven fixing do not make contact with the toner and are melted and fixed. Inferior to
Further, even when fixing with a heat roll, the surface is temporarily smoothed under the heat roll, but the image surface becomes uneven due to the cohesive force acting inside the toner until it comes out of the heat roll and the toner is cooled. As described above, even when heat roll fixing, flash fixing, or oven fixing is used, an image with high smoothness could not be obtained.

Further, if the storage elastic modulus and loss elastic modulus of the toner are lowered, good fixing surface smoothness can be obtained by a usual fixing method, but such a toner is inferior in offset resistance and is subjected to a continuous printing test. In, there is charge deterioration,
There was a problem of poor storage stability.

An object of the present invention is to provide a color electrophotographic apparatus having a long toner life, excellent storage stability, good offset resistance and good image smoothness.

[0007]

The present invention solves the above problems.
To determine, an electrostatic latent image is formed on the photoconductive insulator layer,
Forming a toner image from the electrostatic latent image,
On the recording paper, heat and melt this toner,
Next, a device for performing electrophotographic recording by fixing the recording paper on the recording paper.
Storage cartridge at 150 ° C. as the toner.
Sex ratio is 5 × 10 ²-10^Four dyn / cm²And loss
Elasticity is 10³-10^Four dyn / cm²Color toner
This toner was heated and melted and then immediately cooled immediately, followed by
To be equipped with a cooling roll for fixing it on the recording paper.
A characteristic color electrophotographic apparatus is provided.

In the present invention, that is, a high viscoelastic toner is used, and the melted toner is rapidly cooled and fixed immediately after the heating and melting step of the toner. The heating and melting of the toner can be performed by, for example, a hot roll, flash light or an oven, and the molten toner is rapidly cooled by using a cooling roll.

[0009]

[Function] To improve the smoothness of the fixed image of the toner,
In the fixing step, it is necessary to deform the powder toner on the surface having high smoothness and continue to apply pressure until it is fixed. That is, the above contents can be realized by pressure fixing, but in the heat roll fixing device, the toner is fixed after leaving the fixing device.
Due to the cohesive force inside the toner, the image surface becomes uneven. Further, in flash fixing and oven fixing, since the toner is not in contact with the toner, unevenness of the image surface is remarkable. Therefore, the inventors of the present invention provide a new cooling roll until the temperature of the toner is lowered and the toner is fixed (while the toner is in a molten state) after the toner is melted. Forcibly quench the toner under a high roll,
By fixing, an image with high smoothness could be realized.

Since the fixing roll and the cooling roll are independent of each other, the mutual temperature influences are less likely to occur.
The fixing roll can be controlled at a high temperature, and the cooling roll can be controlled at a low temperature.

In the present invention, the cooling roll is preferably equipped with a fan at its end. Also, 2 cooling rolls
It may be composed of more than one pair of rolls, or may be an apron type roll combined with an endless sheet. By providing a fan at the end of the cooling roll, the cooling roll can be controlled to 100 ° C. or lower, and cooling can be effectively performed. Further, by using the apron type cooling roll, the same effect as substantially enlarging the circumference of the cooling roll can be obtained, so that the cooling effect on the sheet surface enables efficient cooling.

Any material can be used as the material of the cooling roller as long as smoothness can be obtained, and specifically, aluminum and rubber can be specifically mentioned. However, an aluminum roll having a high degree of smoothness but a high hardness cannot absorb the elasticity of the molten toner, resulting in poor smoothness of the obtained image. Further, in the case of a rubber roll, if the thickness of the rubber layer is 1 mm or less, the hardness of the core material of the roll exerts an influence, so that it is difficult to obtain good smoothness. Therefore, the rubber thickness is preferably 1 mm or more. Further, if the hardness of the rubber is too low, there is a problem that the deterioration is fast, and conversely, if the hardness is too high, the elasticity of the molten toner cannot be absorbed, and thus the smoothness cannot be improved. Therefore, the rubber hardness is preferably 30 to 60 degrees.

Further, the nip width of the cooling rubber roll is 5 m.
It is preferably m or more, and silicon rubber is preferably used as the rubber. Further, the time from the melting process until entering the cooling rubber roll is preferably 1 second or less, and the linear pressure of the cooling rubber roll is preferably 5 kg / cm or more.

On the other hand, as a result of further study from the viewpoint of the toner in order to obtain the surface smoothness, it was found that those having a low storage elastic modulus and a low loss elastic modulus are preferable. However, as described above, a toner having a low storage elastic modulus and a low loss elastic modulus has a short life and poor storage stability. Therefore, as a result of an examination for satisfying all the characteristics of surface smoothness, life characteristics and storage stability, as a result of clearing the life characteristics and the storage stability with a toner having a high storage elastic modulus and loss elastic modulus,
It has been found that the use of a cooling roll improves the surface smoothness.

The binder resin used in the toner may be an epoxy resin, a styrene-acrylic acid ester copolymer, a polyester resin, a polyurethane resin, or the like. As the binder resin satisfying the transparency and offset property of the resin, polyester is preferable. Resin is the best choice. Further, in order to improve the offset resistance, such polyester resin,
Containing a component consisting of a trifunctional or higher polyfunctional monomer,
It is desired to contain 0% by weight or less of chloroform insoluble matter. Further, in order to improve the storage stability (blocking resistance) of the toner, the glass transition temperature of the resin is 5
The temperature is preferably 0 ° C. or higher, while the glass transition temperature of the resin is 70 in order to enable fixing at 100 to 180 ° C.
It is desirable that the temperature is not higher than ° C.

As the pigment of the toner useful in the present invention, quinacridone, monoazo, bisazo, perylene, naphthol, copper phthalocyanine pigment and the like can be used. Further, a metal-containing dye, a fatty acid ester or a compound having an amino group may be added as a charge control agent.

The toner used in the present invention can be manufactured by a conventionally known method. That is, the binder resin, the pigment, and the charge control agent are melt-kneaded by, for example, a pressure kneader, an extruder or the like, uniformly dispersed, and classified by, for example, an air classifier to obtain a desired toner.

An example of the structure of the apparatus according to the present invention is schematically shown in FIG. In the figure, 1 is a photoconductor, 2 is an exposing device, 3 is a charging device, 4 is a photoconductor cleaner, 5 to 8 are developing devices for each color of yellow, magenta, cyan, and black, 9 is an intermediate transfer member, and 10 is an intermediate. A transfer belt cleaner 11 is a transfer roller.

The color printer is composed of a photoconductor 1 which is an optical semiconductor, and a charger 3 for charging the surface of the photoconductor to a predetermined polarity, and an exposure device for exposing the photoconductor according to an image signal. 2, developing devices 5 to 8 that visualize an invisible electric electrostatic latent image with toner, a cleaner 4 for removing residual toner remaining on the photoconductor after the primary transfer from the photoconductor, And an intermediate transfer unit having a structure in which a belt-shaped intermediate transfer body 9 is laid over the intermediate transfer body transport roller 12, a secondary transfer roller 11 for secondarily transferring a toner image from the intermediate transfer body to a recording medium, a secondary transfer A cleaner 10 for removing residual toner remaining on the intermediate transfer body from the intermediate transfer body later, further carrying rollers 13a and 13b for carrying the recording medium, a carrying belt 14 for carrying the recording medium, and carrying the same. Roller belt is are passed over 15
a, 15b, and a fixing device portion for fixing the toner image transferred onto the recording medium onto the recording medium. Here, the fixing device portion has a structure as shown in FIG.

The developing device has three primary colors necessary for full-color output from subtractive color mixing, that is, color toners of yellow (Y), magenta (M) and cyan (C), and black used for character portions ( BK) toners are respectively put in, and each color is developed. In addition, each developing device is provided with a separating / contacting mechanism which is in a state of being sufficiently separated from the photoconductor when not in operation, and which moves forward to a distance where only the developing device in which the toner of the color to be developed is put can develop. .

The principle of recording is that the surface of the photoconductor is uniformly charged by the charging device, and then exposure is performed by the exposure device according to, for example, Y image information to form an electrostatic latent image, and then Y toner is added. Only the developed developing device advances to the photoconductor by the separating / contacting mechanism, develops Y, and forms a Y toner image on the photoconductor. Then, at the primary transfer part, Y
The toner image is primarily transferred from the photoconductor to the intermediate transfer body. After the primary transfer, the photoconductor is cleaned by the cleaner and then charged again by the charger, and thereafter, the development of M, C and BK and the primary transfer are sequentially performed in the same sequence, and finally the intermediate transfer member is obtained. A full-color toner image in which the above four types of color toners are overlapped is formed on the top.

Thereafter, the recording medium is conveyed to the secondary transfer portion by the recording medium conveying roller, and the secondary transfer roller, which has been separated from the intermediate transfer body until the completion of all the primary transfer, is moved to the intermediate transfer body by the separating / contacting mechanism. The transport roller and the intermediate transfer body and the recording medium are sandwiched and pressed against each other, and the color toner image on the intermediate transfer body is secondarily transferred onto the recording medium. After the secondary transfer, the recording medium is conveyed on the conveying belt of the recording medium and is sent to the fixing unit, and the color toner image is fixed on the recording medium.
Also, the toner image remaining on the intermediate transfer member after the secondary transfer is
The intermediate transfer body cleaner, which has been separated from the intermediate transfer body until the completion of all the primary transfer, is cleaned by being pressed against the intermediate transfer body by the separating / contacting mechanism, and the intermediate transfer body waits for the next primary transfer. .

The transferred toner layer 16 is a heat roll pair 17
The molten toner 18 is rapidly fused and fixed by the cooling roll pair 19 to give a smooth image 20.

[0024]

The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

Example 1 Polyester resin 95 parts by weight (glass transition temperature 60 ° C., chloroform insoluble content 5% by weight) Yellow: KET Yellow 402 (Dainippon Ink and Chemicals) 5 parts by weight Magenta: KET Red 308 (Dainippon Ink and Chemicals) Industry) 5 parts by weight Cyan: KET BLUE 106 (Dainippon Ink and Chemicals) 5 parts by weight

The resin and the pigment are mixed and stirred by a ball mill, melt-kneaded by an extruder heated to 100 ° C., cooled and solidified, and then coarsely crushed by a crusher,
Further, it was pulverized with a jet mill. The obtained fine powder was classified by an air classifier to obtain yellow, magenta and cyan toners having a particle size of 5 to 20 μm.

The viscoelastic properties of these toners are shown below. Storage elastic modulus (dyn / cm ² ) Loss elastic modulus (dyn / cm ² ) at 150 ° C. Yellow 3.0 × 10 ³ 7.0 × 10 ³ Magenta 3.1 × 10 ³ 7.2 × 10 ³ Cyan 3. 0 x 10 ³ 7.1 x 10 ³

Next, as shown in FIG. 2, a fixing device provided with a cooling roll pair 19 at a point 40 mm away from the heat roll pair 17 (0.5 seconds after passing through the heat roll) was used under the following conditions. In addition, by using 5% by weight of the toner and 95% by weight of resin-coated ferrite powder (average particle size 40 μm) as a carrier, three-color simultaneous printing can be performed, and a laser printer employing a heat roll fixing device can be used. A printing test was conducted.

Printing speed 80 mm / s Heat roll temperature 190 ° C. Nip width 4 mm Linear pressure 3 kg / cm Cooling roll material Silicon rubber Rubber hardness 50 degrees Rubber thickness 4 mm Linear pressure 7 kg / cm

As a result of the fixing test, the obtained print was excellent in the smoothness of the image surface and the glossiness (45-degree specular gloss) was 28. The printed image was excellent in color mixing and transparency. Further, as a result of a continuous printing test of 100,000 sheets, it was found that offset did not occur at all, the toner charge amount did not decrease, and the print quality did not change from the initial stage.

Example 2 Printing and evaluation were performed in the same manner as in Example 1 except that an aluminum roller was used as the cooling roller. as a result,
Similarly good results have been obtained.

Example 3 The same processing as in Example 1 was carried out except that fixing was performed using an oven instead of the hot rolls, and similarly good results were obtained.

Example 4 The same processing as in Example 1 was carried out except that the linear pressure of the cooling roll was set to 5 kg / cm, and similarly good results were obtained.

Example 5 The same treatment as in Example 1 was carried out except that the rubber hardness of the cooling roll was set to 30. As a result, the same good result as in Example 1 was obtained.

Example 6 The same treatment as in Example 1 was carried out except that the rubber thickness of the cooling roll was 1.5 mm. As a result, the same good result as in Example 1 was obtained.

Example 7 The same process as in Example 1 was carried out except that the cooling roller was provided 70 mm away from the hot roll (the point where the molten toner left the hot roll for 0.88 seconds). as a result,
Good results similar to those of Example 1 were obtained.

Example 8 As a binder resin, a polyester resin having a chloroform insoluble content of 10% by weight was used, and a pigment similar to that used in Example 1 was used to prepare a toner in the same manner as in Example 1.

The viscoelastic properties of these toners are shown below. Storage modulus at 150 ° C. (dyn / cm ² ) Loss modulus (dyn / cm ² ) Yellow 5.0 × 10 ³ 7.0 × 10 ³ Magenta 5.1 × 10 ³ 7.1 × 10 ³ Cyan 5. 1 × 10 ³ 7.1 × 10 ³ Next, as a result of evaluation in the same manner as in Example 1, good results were obtained as in Example 1.

Example 9 A toner was experimentally manufactured in the same manner as in Example 1 using a polyester resin having a chloroform insoluble content of 15% by weight as the binder resin and using the same pigment as that used in Example 1. .

The viscoelastic properties of these toners are shown below. Storage elastic modulus at 150 ° C. (dyn / cm ² ) Loss elastic modulus (dyn / cm ² ) Yellow 7.0 × 10 ³ 8.0 × 10 ³ Magenta 7.1 × 10 ³ 8.1 × 10 ³ Cyan 7. 1 × 10 ³ 8.1 × 10 ³ Next, as a result of evaluation in the same manner as in Example 1, good results were obtained as in Example 1.

Example 10 A toner was experimentally manufactured in the same manner as in Example 1 except that a polyester resin having a chloroform insoluble content of 20% by weight was used as the binder resin and the same pigment as that used in Example 1 was used. .

The viscoelastic properties of these toners are shown below. Storage elastic modulus at 150 ° C. (dyn / cm ² ) Loss elastic modulus (dyn / cm ² ) Yellow 9.0 × 10 ³ 9.8 × 10 ³ Magenta 9.1 × 10 ³ 9.9 × 10 ³ Cyan 9. 1 × 10 ³ 9.9 × 10 ³ Next, as a result of evaluation in the same manner as in Example 1, good results were obtained as in Example 1.

Comparative Example 1 A toner was experimentally manufactured in exactly the same manner as in Example 1 except that a polyester resin having a chloroform insoluble content of 0% by weight was used as the binder resin.

The viscoelastic properties of these toners are shown below. Storage elastic modulus at 150 ° C. (dyn / cm ² ) Loss elastic modulus (dyn / cm ² ) Yellow 4.0 × 10 ² 9.0 × 10 ² Magenta 4.3 × 10 ² 9.2 × 10 ² Cyan 4. 3 x 10 ² 9.3 x 10 ²

Next, as a result of printing and evaluation in the same manner as in Example 1, the smoothness of the image surface was good, and OH
The transmission image of P also had a high saturation, but as a result of the continuous printing test, the storage elastic modulus and the loss elastic modulus were low, so that the offset occurred at a ratio of 1/100 sheets.

Comparative Example 2 A toner was experimentally manufactured in exactly the same manner as in Example 1 except that a polyester resin having a chloroform insoluble content of 25% by weight was used as the binder resin.

The viscoelastic properties of these toners are shown below. Storage elastic modulus at 150 ° C. (dyn / cm ² ) Loss elastic modulus (dyn / cm ² ) Yellow 3.0 × 10 ⁴ 5.0 × 10 ⁴ Magenta 3.1 × 10 ⁴ 5.2 × 10 ⁴ Cyan 3. 1 x 10 ⁴ 5.2 x 10 ⁴

Next, as a result of printing and evaluation as in Example 1, the storage elastic modulus and the loss elastic modulus were high, so that the smoothness of the image surface was poor and the saturation of the OHP transmission image was low. However, as a result of the continuous printing test, no offset occurred.

Comparative Example 3 A test was conducted in the same manner as in Example 1 except that no cooling roll was provided. In this case, it was confirmed that the smoothness of the image surface was inferior, the glossiness was 7, the OHP transmission image had low saturation, and the image quality was poor.

Example 11 A toner was obtained in the same manner as in Example 1 except that a polyester resin having a glass transition temperature of 50 ° C. was used, and a printing test was conducted in the same manner as in Example 1. As a result, the same as in Example 1 was obtained. Very good results were obtained.

Example 12 A toner was obtained in the same manner as in Example 1 except that a polyester resin having a glass transition temperature of 70 ° C. was used, and a printing test was conducted in the same manner as in Example 1. As a result, the same as in Example 1 was obtained. Very good results were obtained.

Comparative Example 4 A toner was obtained in the same manner as in Example 1 except that a polyester resin having a glass transition temperature of 45 ° C. was used, and a printing test was carried out in the same manner as in Example 1. As a result, the storage stability was poor. I understood it.

Comparative Example 5 A toner was obtained in the same manner as in Example 1 except that a polyester resin having a glass transition temperature of 75 ° C. was used, and a printing test was conducted in the same manner as in Example 1 to find that the fixability was poor. I understood.

Example 13 As shown in FIG. 2, using a fixing device provided with a cooling device at a point 40 mm away from the heat roll (0.5 seconds after passing through the heat roll), polyester resin was added under the following conditions. A fixing test of a color toner (softening point 105 ° C.) as a binder was conducted.

Printing speed 80 mm / s Heat roll temperature 180 ° C. Nip width 5 mm Linear pressure 15 kg / cm Cooling roll material Silicon rubber Rubber hardness 50 degrees Rubber thickness 4 mm Linear pressure 15 kg / cm

The composition and characteristics of the toner used are as follows. Polyester resin 95 parts by weight (glass transition temperature 60 ° C, chloroform insoluble content 5% by weight) Yellow: KET Yellow 402 (Dainippon Ink and Chemicals) 5 parts by weight Storage elastic modulus at 150 ° C (dyn / cm ² ) Loss elastic modulus ( dyn / cm ² ) 3.0 × 10 ³ 7.0 × 10 ³

As a result of the fixing test, the smoothness of the image surface was excellent and the glossiness (45 degree specular gloss) was 28. Also,
Good transparency was also confirmed in OHP printing.

Example 14 A fixing test was conducted in the same manner as in Example 13 except that a fan was provided at the end of the cooling roll as shown in FIG. Next, as a result of evaluation in the same manner as in Example 13, similarly good results were obtained. It was also confirmed that the cooling roller did not exceed 100 ° C. even after printing 1000 sheets by continuous printing.

Example 15 A fixing test was conducted in the same manner as in Example 13 except that two pairs of cooling rolls were provided as shown in FIG. At this time, the two pairs of cooling rolls rotate around points E and F as fulcrums, respectively. That is, at the time of a in FIG. 4, the sheet is sandwiched between the cooling rolls B and C, but after a certain period of time, the state of B is changed to the state of C,
The paper is sandwiched between the cooling rolls A and D. By doing so, the cooling roll draws heat from the molten toner and the temperature rises. However, by providing two pairs of cooling rolls, it is possible to create a state in which the sheet does not come into contact with the paper and suppress the temperature rise of the cooling roll. .

Next, as a result of evaluation in the same manner as in Example 13,
Similarly good results have been obtained. It was confirmed that the cooling roller did not exceed 100 ° C. even after 1000 sheets were printed by continuous printing by rotating the cooling roll with fulcrums as the fulcrum after every 50 sheets were printed, and the effect of the cooling roller could be maintained.

Example 16 As shown in FIG. 5, the cooling rolls 22 and 23 are sandwiched between endless polyimide films (thickness 10 μm) 24 and 25, and the sheets are rotated with 26, 27 and 28 and 29 as fulcrums, respectively. . By using such an apron-type cooling roll, the sheet has a time not in contact with the recording paper 21 and is cooled during that time, so that the temperature rise can be suppressed. As a result of evaluation in the same manner as in Example 13, similarly good results were obtained. In addition, 1000 can be printed continuously.
It was confirmed that the cooling roller did not exceed 100 ° C. even after printing one sheet, and the effect of the cooling roll could be maintained.

Example 17 A fixing test was conducted in the same manner as in Example 13 except that flash fixing was carried out instead of hot roll fixing. Next, Example 1
When evaluated in the same manner as in Example 3, similarly good results were obtained.

Example 18 A fixing test was conducted in the same manner as in Example 13 except that oven fixing was performed instead of hot roll fixing. Next, Example 13
As a result of evaluation in the same manner as above, similarly good results were obtained.

Example 19 Example 1 except that the linear pressure of the cooling roll was set to 5 kg / cm.
The fixing test was conducted in the same manner as in No. 3. Then, as a result of evaluation in the same manner as in Example 13, similarly good results were obtained.

Example 20 A fixing test was conducted in the same manner as in Example 13 except that the rubber hardness of the cooling roll was changed to 30. Next, as a result of evaluation in the same manner as in Example 13, similarly good results were obtained.

Example 21 Example 1 except that the cooling roll had a rubber thickness of 1.5 mm.
The fixing test was conducted in the same manner as in No. 3. Then, as a result of evaluation in the same manner as in Example 13, similarly good results were obtained.

Example 22 A fixing test was conducted in the same manner as in Example 13 except that the cooling roll was provided at a position 70 mm away from the heat roll (a point where 0.88 seconds passed after the molten toner left the heat roll). Then, as a result of evaluation in the same manner as in Example 13, similarly good results were obtained.

Comparative Example 6 In the same fixing test as in Example 13, continuous printing was performed. When the number of sheets exceeds 50, the chill roll temperature exceeds 100 ° C, and thereafter, the smoothness of the image surface is poor and the glossiness is 9
showed that. Further, as the number of printed sheets increased, the temperature of the cooling roll increased and the image smoothness deteriorated. In addition, the transparency of the OHP transmission image was low and the image quality was poor.

Comparative Example 7 A fixing test was conducted in the same manner as in Example 13 except that the cooling roll was not provided. Next, as a result of evaluation in the same manner as in Example 13, the smoothness of the image surface was poor, and the glossiness was 7. In addition, the transparency of the OHP transmission image was low and the image quality was poor.

Comparative Example 8 After fixing by flash in the same manner as in Example 14 except that the cooling roll was not provided, a fixing test with a cooling roll was conducted.
Next, as a result of evaluation in the same manner as in Example 13, the smoothness of the image surface was poor, and the glossiness was 4. In addition, the transparency of the OHP transmission image was low and the image quality was poor.

[0071]

According to the present invention, it is possible to provide a color electrophotographic apparatus having a long toner life, excellent storage stability, good offset resistance, and good image smoothness.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an example of an apparatus according to the present invention.

FIG. 2 is a diagram showing an outline of a fixing device used in the examples.

FIG. 3 is a diagram showing an outline of a cooling roll with a fan used in Examples.

FIG. 4 is a diagram showing an outline of a cooling roll having a two-pair structure used in Examples.

FIG. 5 is a diagram showing an outline of an apron type cooling roll used in Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photosensitive member 2 ... Exposure device 3 ... Charging device 4 ... Photosensitive member cleaner 5, 6, 7, 8 ... Developing device 9 ... Intermediate transfer member 10 ... Intermediate transfer belt cleaner 11 ... Transfer roller 12 ... Intermediate transfer member transport roller 13 ... conveying roller 14 ... conveying belt 15 ... roller 16 ... toner layer 17 ... heat roll 18 ... melting toner 19 ... cooling roll 20 ... smooth image 21 ... recording paper 22,23 ... cooling rolls 24,25 ... endless sheets 26,27, 28, 29 ... fulcrum

Claims (3)

[Claims] 1. An electrostatic latent image is formed on a photoconductive insulator layer.
To form a toner image from the electrostatic latent image.
Transfer the image onto recording paper and heat this toner to melt it.
And then fix it on the recording paper for electrophotographic recording.
Device for storing the toner at 150 ° C.
Storage elastic modulus is 5 × 10²-10^Four dyn / cm ²And
Loss elastic modulus is 10³-10^Four dyn / cm²Is the carato
This toner is heated and melted and then immediately cooled immediately before
Equipped with a cooling roll for fixing the recording paper.
And a color electrophotographic device. 2. The color toner as the color toner, wherein the binder resin contains a polyester resin containing a component consisting of a polyfunctional monomer having three or more functional groups, and the polyester resin contains 20% by weight or less of a chloroform insoluble component. The color electrophotographic apparatus according to claim 1, wherein 3. The glass transition temperature of the binder resin is 5
The color electrophotographic apparatus according to claim 2, wherein a color toner having a temperature of 0 to 70 ° C. is used.