JPH06214423A - Image forming method - Google Patents

Abstract

PURPOSE:To provide the image forming method capable of freely controlling the glossiness of the image on a photosensitive material without decreasing the number of sheets of the images to be discharged per unit time and without generating fixing defects. such as offset, regardless of the presence or absence of gloss by using a small-sized image forming device. CONSTITUTION:The distance between the transfer sepn. position of the transfer separating means and fixing section 111 of fixing means of the image forming device to be used in the method for forming the images by latent image forming, developing, transferring and fixing is longer than the max. length of a recording material 114 to be used and the fixing means has a heating roll and press roll which are changable in rotating speed. The toners to be used contain a polyester resin which does not contain the insoluble component of tetrahydrofuran. The resin component has 25,000 to 80,000 weight average mol.wt. (Mw), 2,000 to 10,000 number average mol.wt. (Mn) and Mw/Mn>=10 and the temp. at which the apparent melt viscosity of the toners attains 1X10<4> poise is 115 to 140 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method which is small in size, consumes less power, and can freely control the glossiness of an image on a recording material.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus using an electrophotographic method, an upper roll and a lower roll are provided as fixing means for the recording material, the upper roll and the lower roll being opposed to the front surface (toner image forming surface) and the rear surface, respectively. A heating roll fixing device configured to heat these rolls to a predetermined temperature by a heating means such as a heater or a lamp is widely used. The glossiness of the output image mainly depends on the composition of the toner used, the recording material, the amount of toner on the recording material, the configuration of the fixing device used in the image forming apparatus, and the fixing conditions. In particular, if the above conditions are not changed, the glossiness of the output image is almost uniquely determined regardless of the glossiness of the original image. On the other hand, manuscript images include photographic images with high glossiness to general business documents with low glossiness, and from the aspect of faithful reproduction of manuscript images, they are conventionally sold on the market. An image forming apparatus using an electrophotographic method is insufficient, and if necessary,
It is an important issue to change the above-mentioned factors that control the glossiness.

An example of a conventional image forming apparatus that changes such factors that control the glossiness is, for example, JP-A-60-
A device having a means for changing the fixing condition disclosed in Japanese Patent No. 51866 is known. FIG. 3 is a block diagram of the image forming apparatus. The operation will be briefly described below. The original on the original table passes through the mirrors 301 and 302 and the lens 303, and is color-separated through the color filter 304.
8, a light image is projected on the photoconductor 306 to form an electrostatic latent image. The electrostatic latent image is then developed by the developing unit 3.
At 09, it is developed with the toner of the first color and reaches the transfer portion. At the same time, the recording material 311 is sucked and conveyed onto the transfer drum 310, reaches the transfer portion, and the toner image is transferred. Similarly, the toner images of the second color and the third color are transferred onto the recording material 311 with their positions being synchronized, and then the recording material 311 is separated by the peeling section 31.
The toner image is peeled off from the transfer drum 310 at 2, and the toner image is fixed at the fixing device 314 through the transport unit 313 and is discharged.
At this time, the fixing device 314 can change its operation speed according to the type of the recording material 311 and select an appropriate fixing condition.

An image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 4-1670 is an example of an image forming apparatus that also has means for changing fixing conditions and is advantageous for downsizing. FIG. 4 is a schematic configuration diagram of the image forming apparatus. The operation will be briefly described below. The document on the platen is color-separated by the reading unit 401 and converted into image signals. The surface of the photoconductor 403 is uniformly charged by the first charger 404, and then the laser scanning optical device 40
The laser light modulated in accordance with the image information of the first color by 2 is applied to the photoconductor 403, whereby the electrostatic latent image of the first color is formed on the photoconductor 403. Then, the electrostatic latent image of the first color on the photoconductor 403 is transferred to the developing device 4
By 05, the toner image of the first color is developed and visualized, and the toner image of the first color is formed. The first-color toner image formed on the photoconductor is conveyed to the transfer portion as the photoconductor 403 rotates. At this time, the transfer belt 406 is separated from the photoconductor surface as shown in FIG. Yes, the image passes through undisturbed. In addition, the fur brush 407
Is also separated from the surface of the photoconductor, and the image passes without being disturbed. The photoconductor is recharged again by the first charger 404, and the laser beam modulated by the laser scanning optical device 402 in accordance with the image information of the second color is fed to the photoconductor 4.
03, and is developed with a second color toner to form a two-color toner image on the photoconductor. Similarly, the third color, 4
After the color toner image is formed on the photoconductor, the transfer belt 406 is pressed against the photoconductor at the same time as the position of the toner image and the recording material conveyance by the resist roll 408.
The toner image is transferred onto the recording material 410 by the second charger 409. The recording material 410 to which the toner image has been transferred is conveyed while being attached to the transfer belt 406, separated by curvature separation, fixed by the fixing device 411, and discharged. Also in this apparatus, the fixing condition can be selected by changing the operating speed of the fixing device.

Further, in Japanese Patent Laid-Open No. 3-116175, primary fixing means for melting the toner by irradiating the toner image on the recording material with a heat ray from a lamp, and the toner image is melted by the primary fixing means. After being fixed, it is constituted by a secondary fixing unit that fixes the toner image by passing between the heating roll and the backup roll under pressure contact with the heating roll, and the secondary fixing unit connects the heating roll and the backup roll. An image forming apparatus having two fixing means in series, which is provided with a separating means, is disclosed.

Further, Japanese Patent Laid-Open No. 4-157482 discloses a first fixing device which is set under normal fixing conditions and a strengthening fixing setting for fixing a toner image so that it is sufficiently fused and fixed to have gloss. Of the second fixing device, the image forming apparatus having two fixing devices in parallel is fixed by any one of the fixing devices by switching the recording material transportation by the recording material transportation device. There is.

In Japanese Utility Model Laid-Open No. 4-42658,
From the viewpoint of achieving both high-gloss color images and low-gloss black-and-white images in a color image forming apparatus, the rotary developing device includes three types of chromatic color developing devices and high-gloss color image forming black developing devices. And an image forming apparatus having a black developing device for forming a black and white image of low gloss, which is provided separately from the rotary developing device.

[0008]

However, the above-mentioned JP-A-60-51866 and JP-A-4-16 are mentioned above.
In the configuration as described in Japanese Patent Publication No. 70, when the process speed of the photoconductor or the transfer drum and the speed of the fixing device are operated differently, at the time when the leading end of the recording material enters the fixing device, the recording material is The transfer separation operation must be completed and the transfer drum or the photosensitive member must be separated.

This is also referred to in Japanese Patent Application Laid-Open No. 4-1670, and in particular, by using the batch transfer method as the transfer means, it is not necessary to perform registration between colors in the transfer means. It is easy to separate the transport unit from the photoconductor to make the speed variable, and low-speed fixing can be performed immediately after the transfer operation is completed, so the distance from the transfer unit to the fixing unit can be minimized. It is described that the effect is extremely large for the miniaturization of. However, since the color toners are superposed on the photoconductor to form an image, it is not necessary to align the colors in the transfer means, but the miniaturization of the apparatus is insufficient. That is, in the configurations shown in FIGS. 3 and 4 disclosed in Japanese Patent Laid-Open No. 60-51866 and Japanese Patent Laid-Open No. 4-1670, the transfer / separation unit is arranged approximately at the center of the apparatus main body. Therefore, the size (width) of the main body of the apparatus is about three times the distance between the transfer separation section and the fixing section, and it is difficult to say that it is effective for downsizing the apparatus.

Further, the configurations described in Japanese Patent Laid-Open No. 3-116175 and Japanese Patent Laid-Open No. 4-157482 require two fixing means, and it is hard to say that they are appropriate means in terms of power consumption and cost. .

As described above, in the conventional example, in order to control the glossiness of the output image, the fixing condition has been changed or the structure of the fixing device has been devised. No mention is made of the composition of the toner itself which fixes the image visualized on the material. Generally, the factor that governs the fixing property of the toner is the physical properties of the binder resin that is the main component of the toner, and typical binder resins for the toner include styrene-acrylic resins and polyester resins.

The styrene-acrylic resin body generally has a relatively high softening point temperature and is suitable for obtaining an output image having low gloss, but is very high for obtaining an output image having high gloss. Since it is necessary to give heat and it is difficult to achieve this within the range of limited power consumption, therefore, the size of the device and the increase in power consumption are inevitable. Further, it is possible to lower the softening point temperature by lowering the molecular weight of the styrene-acrylic resin and thereby reduce the amount of heat required for fixing, but lowering the molecular weight of the styrene-acrylic resin reduces the image strength. There is a problem in that the output image is deteriorated and the output image is cracked due to bending or the like.

Polyester resins are often used in toners of electrophotographic color image forming apparatuses currently on the market, and generally have a relatively low softening point temperature,
It is suitable for obtaining an output image having high gloss. However, the toner using the polyester resin currently on the market is less likely to have a low gloss even if the fixing heat amount is lowered in order to obtain an output image having a low gloss. It has drawbacks such as a reduction in color reproduction area due to a decrease in color developability and a fixing failure such as low temperature offset in a high image density area.

In view of this, it is the actual flat plate 4 that is constructed.
Although it is an image forming apparatus having the configuration disclosed in Japanese Patent Publication No. 42658/42, it requires two developing devices for black color, and it cannot be said that it is an appropriate means in terms of power consumption and cost.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide an image forming method using an image forming apparatus which is small in size and does not increase power consumption. Another object of the present invention is not to reduce the number of discharged images per unit time, to prevent fixing defects such as offset regardless of the presence or absence of gloss, and to freely adjust the glossiness of an image on a recording material. An object is to provide a controllable image forming method.

[0016]

The present invention provides at least the following:
A latent image forming unit that forms an electrostatic latent image by exposing on a uniformly charged photoreceptor, a developing unit that develops the electrostatic latent image with toner, and a formed toner image is transferred to a recording material. An image forming method for forming an image using an image forming apparatus having a transfer separation unit for separating the toner image holding member and a fixing unit for fixing the transferred toner image on a recording material. The means is disposed on one side in the image forming apparatus, the fixing means is disposed in proximity to the other side, and the distance between the transfer separation position of the transfer separation means and the fixing portion of the fixing means is used. The recording medium is longer than the maximum length of the recording material, and the fixing unit has a heating roll and a pressure roll whose rotation speed can be changed, and the toner used is composed of at least a resin component and a colorant. , The resin component is alcohol Containing a tetrahydrofuran-insoluble polyester resin obtained by polycondensing a monomer and a carboxylic acid monomer, the molecular weight and the molecular weight distribution measured by gel permeation chromatography of the resin component have a weight average molecular weight. (Mw) 25,000 to 80,000, number average molecular weight (Mn) 2,000 to 10,000, and weight average molecular weight / number average molecular weight (Mw / Mn) of 10 or more, It is characterized in that the temperature at which the apparent melt viscosity becomes 1 × 10 ⁴ poise is 115 ° C. to 140 ° C. In the present invention, it is preferable that an intermediate transfer material is provided in the transfer separation means in the image forming apparatus.

The present invention will be described below. First, the toner used in the present invention will be described. In the present invention, the toner comprises at least a resin component and a colorant. The resin component is obtained by polycondensing an alcohol monomer and a carboxylic acid monomer. The weight average molecular weight (Mw) of the resin component containing a polyester resin containing no tetrahydrofuran-insoluble component is measured by gel permeation chromatography.
5,000 to 80,000, number average molecular weight (Mn)
It is necessary to have 2,000 to 10,000, and a weight average molecular weight / number average molecular weight (Mw / Mn) of 10 or more.

If the toner contains a tetrahydrofuran insoluble matter, it becomes difficult to obtain a high gloss image. When the weight average molecular weight of the resin component is larger than the above range, it becomes difficult to obtain a high gloss image, and when it is smaller than the above range, it is difficult to obtain a low gloss image. On the other hand, if the number average molecular weight is higher than the above range, the fixing temperature rises, and the power consumption increases accordingly. On the other hand, if it is smaller than the above range, the storage stability of the toner deteriorates. Furthermore, weight average molecular weight / number average molecular weight (Mw / M
When n) is smaller than 10, high temperature offset is likely to occur.

In the toner used in the present invention, the temperature at which the apparent melt viscosity of the toner by the flow tester method becomes 1 × 10 ⁴ poise is 115 ° C. to 1 ° C.
It is necessary that the temperature is 40 ° C., but this temperature means the softening point of the resin component, and this temperature is 115
When the temperature is lower than ℃, it is difficult to obtain a low-gloss image.
When the temperature is higher than 0 ° C, it becomes difficult to obtain a high gloss image.

For measuring the softening point of the resin component, a Shimadzu Flow Tester CFT500-A was used as a measuring device. The measuring conditions were: die = 0.5 mm × 1.0 mm, heating temperature = 5 ° C./min, Load = 10 kg, preheating time = 30
The measurement temperature range was 80 seconds to 190 ° C. for 0 seconds. Further, the molecular weight of the resin component is measured by a fully automatic high temperature high speed chromatograph (WATERS ALC / GPC 1
50 C), tetrahydrofuran was used as a solvent, flow rate = 1.0 ml / min, temperature = 40 ° C., and detector = differential refractometer (RI).

In the present invention, a polyester obtained by polycondensing an alcohol monomer and a carboxylic acid monomer is used as the binder resin containing no tetrahydrofuran insoluble matter. Examples of the alcohol monomer include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3
-Propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol and other diols, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropyleneated bisphenol A and other bisphenols A
Examples thereof include alkylene oxide adducts and other dihydric alcohols.

Further, in order to make the polyester non-linear to the extent that tetrahydrofuran insoluble matter is not generated, a polyhydric alcohol having a valence of 3 or more is used. For example, sorbitol, 1,2,3,6-hexanetetrol, 1,4-
Sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methylbutanetriol, trimethylolethane, trimethylolpropane, 1,3,5 -Trihydroxymethylbenzene and others can be mentioned.

Examples of the carboxylic acid monomer include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, Examples thereof include sebacic acid, malonic acids, alkylsuccinic acids, acid anhydrides thereof, alkyl esters, and other divalent carboxylic acids. Furthermore, a trivalent or higher polyvalent carboxylic acid can be used, and for example,
1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1, 2,
4-butanetricarboxylic acid and others can be mentioned.

In the present invention, the resin component may be composed of one kind of polyester, but may be a mixture of linear polyester and non-linear polyester. In that case, the molecular weight and molecular weight distribution of the toner can be arbitrarily controlled within a suitable range by adjusting the mixing ratio of the linear polyester and the non-linear polyester.

Next, the image forming apparatus used in the present invention will be described. The image forming apparatus used in the present invention includes a latent image forming unit that exposes a uniformly charged photosensitive member to form an electrostatic latent image, a developing unit that develops the electrostatic latent image using toner, It has a transfer separation unit that transfers the formed toner image to a recording material and separates it from the toner image carrier, and a fixing unit that fixes the transferred toner image on the recording material. In this image forming apparatus, the transfer separation unit is located near one side of the image forming apparatus, and the fixing unit is located near the other side of the image forming apparatus.
The transfer separation position of the transfer separation unit and the fixing unit of the fixing unit are placed such that the distance between them is longer than the maximum length of the recording material used. Further, the fixing unit has a heating roll and a pressure roll capable of changing the number of rotations, so that the fixing speed can be changed regardless of the speed until the toner image is formed on the recording material. Has become. In the present invention, the transfer separation means preferably has an intermediate transfer member. When the intermediate transfer body is provided, the toner image formed on the toner image holding body is once transferred onto the intermediate transfer body, and then the toner image is transferred onto the recording material.

In the present invention, the fixing means preferably used is a heating roll and a pressure roll that rotate while being in pressure contact with each other, and a separation for toner offset prevention on the outer peripheral surface of at least one of the heating roll and the pressure roll. A fixing device that includes a release agent supply unit that supplies a mold agent, and fixes the toner image by passing the transfer material on which the unfixed toner image is formed through the heating roll and the pressure roll. A roll and a pressure roll each have a substrate roll having a heat source therein, an inner elastic body layer on which the metal-containing filler is dispersed, and a single layer provided with the inner elastic body layer. Alternatively, a plurality of outer elastic layers are provided respectively.

In the fixing means having this structure, the substrate roll forming part of the heating roll and the pressure roll is
It is necessary to have high heat conductivity and rigidity capable of transferring heat energy from a heating source provided inside these to the inner elastic body layer, and specifically, it is made of a metal material such as stainless alloy or aluminum. can do. Further, for the inner elastic layer provided on these substrate rolls, the elasticity and thickness capable of contacting the heating roll and the pressure roll with an appropriate pressing force and contact width to the transfer material on which the unfixed toner image is formed, It is necessary to have a high heat transfer property capable of transferring heat energy from a heating source to the outer elastic body layer, and specifically, an elastomer in which a metal-containing filler is dispersed, for example, a fluorosilicone elastomer or silicone. It can be composed of various elastomers such as carbon elastomer, other silicone rubber, fluoroelastomer and ethylene-propylenediene rubber, and various copolymers. Here, the upper limit of the rubber hardness of the elastomer forming the inner elastic layers of both rolls is JI.
The S hardness is 80 °, and generally 40 ° to 70 ° when the filler is dispersed.

On the other hand, the outer elastic layer provided on these inner elastic layers has a high heat transfer property capable of transferring the heat energy from the heating source to the toner image on the transfer material, and the toner offset prevention. Fluoroelastomers and silicone elastomers are suitable as the constituent materials because they require affinity with a release agent and abrasion resistance.
As a specific example thereof, a fluoroelastomer, which is a copolymer of vinylidene fluoride and hexafluoropropylene, which is commercially known as Viton A (trademark of EI DuPont), and Fluorel 2170, Fluorel 21
74, Fluorel 2176, Fluorel 2177, Fluorel IVS76 (the above Fluorel is a trademark of 3M Company), Viton GH, Viton EGOG, Viton E4.
30 mag. Specific examples of the silicone elastomer include a high temperature curing type (HTV), a room temperature curing type (RTV) and a low temperature curing type (LT).
V) and the like. Further, in the case of a silicone elastomer, it is preferable to provide an oil resistant layer in the intermediate layer in order to prevent the release agent from entering the inner elastic body layer.
It is also possible to use mixtures of fluoroelastomers based on vinylidene fluoride with other materials, for example tetrafluoroethylene, silicone rubbers, fluorosilicone rubbers and the like. Examples of the metal-containing filler that appropriately adjusts heat conductivity include copper, tin, silver, zinc, aluminum, ruthenium, iron, lead, molybdenum, platinum, gold, beryllium, nickel, chromium, iridium, tungsten, cadmium, vanadium, and the like. Metals, alloys of these metals, metal oxides and metal salts thereof, etc. can be used.

In the present invention, when the transfer of the image to the recording material is completed, the sheet conveying means feeds the recording material to the fixing means at a speed that does not depend on the speed of the photosensitive member, and the fixing means forms the toner image at the required fixing speed. Fix on recording material.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of an image forming apparatus used in the present invention and is a side view for explaining a schematic structure. In the figure, 101 is a charge holding member such as a drum-shaped electrophotographic photosensitive member, around which an electrostatic latent image forming charger 102 and a laser beam scanner 1 are provided.
20, a rotary developing device 104 containing a developer containing toners of yellow, magenta and cyan colors, a developing device 103 containing a developer containing black toners, a primary transfer charger 10
5 and the cleaner 106, and the intermediate transfer member 10 inserted between the photoconductor 101 and the primary transfer charger 105.
7 and a tension roll 108 for maintaining a constant tension
a, a driving roll 10 for driving the intermediate transfer member 107
8b, a bias applying roll 110 which is arranged to face the driving roll via an intermediate transfer member 107 and is rotatable and movable up and down, and also serves as a pressing means, a bias applying roll 110, its backup roll 109, and a recording material moving direction. It has a fixing device 111 arranged in the front.

The photoconductor 101 rotates in the direction of the arrow, and the surface thereof is uniformly charged by the electrostatic latent image forming charger 102.
Then, the laser light modulated according to the image information of the first color is irradiated to perform the exposure of the first color, whereby
An electrostatic latent image of the first color is formed on the photoconductor 101. In this embodiment, the surface potential of the photoconductor 101 is -65.
Set to 0V, the process speed is 200mm / s
ec. Then, the electrostatic latent image of the first color on the photoconductor 101 is developed by the developing device 103 with the toner of the first color to be visualized, and the toner image of the first color is formed. The first color toner image thus formed on the photoconductor 101 is transferred onto the intermediate transfer body 107 by the primary transfer charger 105. An alternating electric field is applied to the developing units 103 and 104 by a developing bias circuit (not shown). The developing bias circuit includes a high-voltage AC power supply that supplies an AC bias and a high-voltage DC power supply that supplies a DC bias. In this embodiment, the DC voltage is −500 V and the AC voltage is 1
It is 600 Vp-p and 6 KHz. The intermediate transfer member 107 is
While holding the toner image of the first color, the drive roll 10
The rotation speed of the photoconductor 101 is 200 mm / se by 8b.
It is rotated and conveyed through each roll at a speed synchronized with c. In the meantime, after the toner remaining on the surface of the photoconductor 101 is scraped off by the cleaner 106,
The surface is evenly irradiated by a pre-exposure device (not shown) to eliminate the non-uniform electric charge received by the optical memory or transfer, and the surface potential is set to about 0V. Then, the second-color toner image forming step including charging by the electrostatic latent image forming charger 102 is repeated on the photoconductor 101, and the second-color toner image is exposed by the second-color development by the rotary developing device 104. Body 101
Formed on. In this embodiment, the intermediate transfer member 10
As No. 7, a polycarbonate in which carbon black is dispersed and whose volume resistivity is adjusted to 10 ¹¹ to 10 ¹⁴ Ω · cm and whose thickness is 150 μm is used.

Then, the second layer formed on the photoconductor 101.
The toner image of the first color is transferred to the position of the toner image of the first color on the intermediate transfer body 107 that holds the toner image of the first color that is rotated and conveyed in synchronization with the photoconductor 101 by the primary transfer charger 105. It is transcribed and superimposed at the right timing. By repeating this process to form toner images of the third and fourth colors, the intermediate transfer member 107
A multi-layer toner image is formed thereon. Then, the paper feed roll 1 is synchronized with the timing of forming the fourth color toner image.
The recording material 114 is fed by 13 and the registration roll 11
By 5a and 115b, it is guided to the secondary transfer portion which is constituted by the backup roll 109 and the bias applying roll 110 which is also arranged opposite to the backup roll 109 and also serves as a pressing means. Immediately before this, the bias applying roll 110, which also functions as a pressing unit, moves to move the intermediate transfer member 107.
In order not to destroy the unfixed toner image formed above,
The intermediate transfer body 107 is brought into contact with the intermediate transfer body 107 to be rotationally driven and pressed.
The peripheral length of the intermediate transfer member 107 is longer than the length of the recording material 114, and if a portion where an image is not formed is appropriately provided, the unfixed toner image formed on the intermediate transfer member 107 is not destroyed. It becomes easy to bring the bias applying roll 110 into contact with the intermediate transfer member 107. At this time, the bias applying roll 110 is set to 800
A transfer voltage of V is applied, and the backup roll 1 is pressed through the intermediate transfer body 107 with a pressure load of 8 g / cm.
09 is pressed. As a result, the multi-layer toner image formed on the intermediate transfer member 107 is electrostatically transferred onto the recording material 114. The recording material 114 on which the toner image is transferred is
The backup roll 109 easily separates the curvature from the intermediate transfer body 107, guides it to a fixing device 111 via a sheet conveying unit 112, and discharges the sheet to a sheet discharge tray 116.

The distance between the transfer separation position of the image forming apparatus of the present invention and the fixing portion of the fixing device (bias applying roll 1
10 and the nip portion of the fixing device 111) is 430
mm, the size (width) of the apparatus main body is 700 mm, and the maximum paper used in the image forming apparatus of the present invention is A3 size (maximum length: 420 mm).

As the fixing device, the one having the structure shown in FIG. 2 is used. The heating roll 201 and the pressure roll 202 shown in FIG. The heating roll 201 has a 500 W Colts lamp 203 inside.
Substrate roll 204 formed of an aluminum core material having an outer diameter of 43 mm, and 100 parts by weight of crystalline silica with respect to 100 parts by weight of a silicone compound (SH841U manufactured by Toray Industries, Inc.) provided thereon. It is formed by filling and mixing with 0.8 part of a vulcanizing agent (manufactured by Toray Industries, Inc .: RC-4), and its thermal conductivity λ is 0.0017 cal / cm · se.
c · deg, the rubber hardness is 60 in JIS hardness
°, inner elastic body 205 with an approximate thickness t of 3.0 mm
And 100 parts by weight of Viton rubber (E-60C manufactured by DuPont), 2 parts by weight of carbon (manufactured by Tokyo Material Co., Ltd.), and magnesium oxide (MgO: # 30 manufactured by Kyowa Chemical Co., Ltd.) provided on the inner elastic body 205. It is formed by filling and mixing with 10 parts by weight, and its thermal conductivity λ is 0.0005 cal / cm.
・ Outer elastic body 2 with sec · deg and thickness t of 20 μm
And 06.

On the other hand, the pressure roll 202 has 500 W inside.
Substrate roll 207 made of an aluminum core material having an outer diameter of 49 mm, and a silicone compound (Toray: S
H841U) 100 parts by weight of crystalline silica 50
It is formed by filling and mixing 0.8 parts by weight of a vulcanizing agent (manufactured by Toray Industries, Inc .: RC-4) by weight, and its thermal conductivity λ is 0.001.
Rubber hardness is JIS at 5 cal / cm · sec · deg
Inner elastic body 208 having a hardness of 70 ° and an approximate thickness t of 1.0 mm, and Viton rubber (E-60C manufactured by DuPont) provided on the inner elastic body 208.
00 parts by weight, 2 parts by weight of carbon (manufactured by Tokyo Materials Co., Ltd.), and 10 parts by weight of magnesium oxide (manufactured by Kyowa Chemical Co., Ltd .: MgO: # 30) were mixed and formed, and the thermal conductivity λ was 0.
0005 cal / cm · sec · deg, thickness t is 2
The outer elastic body 209 has a thickness of 0 μm.

The heating roll 201 and the pressure roll 202 are pressed against each other by a pressure mechanism (not shown),
A nip width of 6.0 mm is formed in the central portion, the surface temperature of the heating roll 201 is set to 155 ° C., and the surface temperature of the pressure roll 202 is set to 150 ° C., respectively, at a predetermined surface speed in the arrow directions. It is designed to rotate. In addition, 213 is a release material supply means, and is a heating roll 20.
1 is for applying the silicone composition 214. In addition, 215 is an oil pan, 216 is a supply roll,
Reference numeral 217 is a coating roll. The recording material 210 carrying the toner image 211 includes a heating roll 401 and a pressure roll 402.
It is inserted between and fixed.

Next, the formulation of the developer used in the present invention will be shown. Example 1 (1) 100 parts of non-linear bisphenol polyester (polyester A) (bisphenol A-ethylene oxide adduct / bisphenol A-propylene oxide adduct / terephthalic acid / dodecenylsuccinic acid / trimellitic anhydride condensate) (weight average) Molecular weight (Mw) = 83,000 Number average molecular weight (Mn) = 3,600 Weight average molecular weight (Mw) / Number average molecular weight (Mn) = 23 Tetrahydrofuran insoluble content = 0 weight% Apparent melt viscosity by the flow tester method is 1 (Temperature at which the porosity becomes × 10 ⁴ T = 130 ° C.) (2) Carbon black having a primary average particle diameter of 45 mμ

The above components were melted by an extruder, kneaded, cooled, and ground by a jet mill,
The pulverized product was classified to prepare a black toner having a volume average diameter of 7 μm. Table 1 shows the molecular weights and molecular weight distributions of the resin components of the obtained black toner. Table 1 also shows the temperatures at which the apparent melt viscosity of the black toner by the flow tester method becomes 1 × 10 ⁴ poise. The above black toner and hydrophobic silica R972 (manufactured by Nippon Aerosil Co., Ltd.) were mixed using a high-speed rotary mixer, and further mixed with a 50 μm ferrite carrier coated with an acrylic polymer to prepare a black developer.

Example 2 (1) 90 parts of non-linear bisphenol polyester (polyester A) (bisphenol A-ethylene oxide adduct / bisphenol A-propylene oxide adduct / terephthalic acid / dodecenylsuccinic acid / trimellitic anhydride condensate) (Weight average molecular weight (Mw) = 83,000 Number average molecular weight (Mn) = 3,600 Weight average molecular weight (Mw) / Number average molecular weight (Mn) = 23 Tetrahydrofuran insoluble matter = 0% by weight Apparent melting by flow tester method Temperature at which viscosity becomes 1 × 10 ⁴ poise T = 130 ° C.) (2) Linear bisphenol-based polyester (polyester B) 10 parts (bisphenol A-propylene oxide adduct / fumaric acid condensate) (weight average molecular weight (Mw) = 13,000 Number average molecular weight (Mn) = 2,7 0 weight average molecular weight (Mw) / number average molecular weight (Mn) = 4.
(8) Temperature T = 105 ° C. at which apparent melt viscosity by flow tester method becomes 1 × 10 ⁴ poise) (3) Carbon black having a primary average particle diameter of 45 mμ 4 parts

The above components were melted by an extruder, kneaded, cooled, and ground by a jet mill,
The pulverized product was classified to prepare a black toner having a volume average diameter of 7 μm. Table 1 shows the molecular weights and molecular weight distributions of the resin components of the obtained black toner. Table 1 also shows the temperatures at which the apparent melt viscosity of the black toner by the flow tester method becomes 1 × 10 ⁴ poise. The above black toner and hydrophobic silica R972 (manufactured by Nippon Aerosil Co., Ltd.) were mixed using a high-speed rotary mixer, and further mixed with a 50 μm ferrite carrier coated with an acrylic polymer to prepare a black developer.

Example 3 (1) 50 parts of non-linear bisphenol polyester (polyester A) (bisphenol A-ethylene oxide adduct / bisphenol A-propylene oxide adduct / terephthalic acid / dodecenylsuccinic acid / trimellitic anhydride condensate) (Weight average molecular weight (Mw) = 83,000 Number average molecular weight (Mn) = 3,600 Weight average molecular weight (Mw) / Number average molecular weight (Mn) = 23 Apparent melt viscosity by flow tester method is 1 × 10 ⁴ poise Temperature T = 130 ° C.) (2) Linear bisphenol polyester (polyester B) 50 parts (bisphenol A-propylene oxide adduct / fumaric acid condensate) (weight average molecular weight (Mw) = 13,000 number average molecular weight (Mn) = 2,700 weight average molecular weight (Mw) / number average Molecular weight (Mn) = 4.
(8) Temperature T = 105 ° C. at which apparent melt viscosity by flow tester method becomes 1 × 10 ⁴ poise) (3) Carbon black having a primary average particle diameter of 45 mμ 4 parts

The above components are melted by an extruder, kneaded, cooled, and ground by a jet mill,
The pulverized product was classified to prepare a black toner having a volume average diameter of 7 μm. Table 1 shows the molecular weights and molecular weight distributions of the resin components of the obtained black toner. Table 1 also shows the temperatures at which the apparent melt viscosity of the black toner by the flow tester method becomes 1 × 10 ⁴ poise. The above black toner and hydrophobic silica R972 (manufactured by Nippon Aerosil Co., Ltd.) were mixed using a high-speed rotary mixer, and further mixed with a 50 μm ferrite carrier coated with an acrylic polymer to prepare a black developer.

Example 4 (Comparative Example) (1) 30 parts of non-linear bisphenol type polyester (polyester A) (bisphenol A-ethylene oxide adduct / bisphenol A-propylene oxide adduct / terephthalic acid / dodecenyl succinic acid / trimellitic anhydride) Acid condensate) (Weight average molecular weight (Mw) = 83,000 Number average molecular weight (Mn) = 3,600 Weight average molecular weight (Mw) / Number average molecular weight (Mn) = 23 Tetrahydrofuran insoluble matter = 0% Flow tester method (T) = 130 ° C at which the apparent melt viscosity is 1 × 10 ⁴ poise) (2) Linear bisphenol polyester (polyester B) 70 parts (bisphenol A-propylene oxide adduct / fumaric acid condensate) (weight average) Molecular weight (Mw) = 13,000 Number average molecular weight (Mn) 2,700 weight average molecular weight (Mw) / number average molecular weight (Mn) = 4.
(8) Temperature T = 105 ° C. at which apparent melt viscosity by flow tester method becomes 1 × 10 ⁴ poise) (3) Carbon black having a primary average particle diameter of 45 mμ 4 parts

The above components were melted by an extruder, kneaded, cooled, and ground by a jet mill,
The pulverized product was classified to prepare a black toner having a volume average diameter of 7 μm. Table 1 shows the molecular weights and molecular weight distributions of the resin components of the obtained black toner. Table 1 also shows the temperatures at which the apparent melt viscosity of the black toner by the flow tester method becomes 1 × 10 ⁴ poise. The above black toner and hydrophobic silica R972 (manufactured by Nippon Aerosil Co., Ltd.) were mixed using a high-speed rotary mixer, and further mixed with a 50 μm ferrite carrier coated with an acrylic polymer to prepare a black developer.

Example 5 (Comparative Example) (1) 100 parts of linear bisphenol polyester (polyester B) (bisphenol A-propylene oxide adduct / fumaric acid condensate) (weight average molecular weight (Mw) = 13,000 number average) Molecular weight (Mn) = 2,700 Weight average molecular weight (Mw) / Number average molecular weight (Mn) = 4.
8 Temperature T = 105 ° C. at which apparent melt viscosity by flow tester method becomes 1 × 10 ⁴ poise) (2) 4 parts of carbon black having a primary average particle diameter of 45 mμ

The above components are melted by an extruder, kneaded, cooled, and ground by a jet mill,
The pulverized product was classified to prepare a black toner having a volume average diameter of 7 μm. Table 1 shows the molecular weights and molecular weight distributions of the resin components of the obtained black toner. Table 1 also shows the temperatures at which the apparent melt viscosity of the black toner by the flow tester method becomes 1 × 10 ⁴ poise. The above black toner and hydrophobic silica R972 (manufactured by Nippon Aerosil Co., Ltd.) were mixed using a high-speed rotary mixer, and further mixed with a 50 μm ferrite carrier coated with an acrylic polymer to prepare a black developer.

[0047]

[Table 1]

A toner image was formed on the recording material by the above-mentioned image forming apparatus using the black developer shown in Examples 1 to 5, and the image samples were evaluated when the fixing speed was changed. It was Table 2 shows the evaluation results in that case.

[0049]

[Table 2]

As is clear from Table 2, the developers of Examples 1 to 3 have excellent fixability when the speed of the fixing device is in the range of 80 to 200 mm / sec, and from low gloss images (gloss degree of 30 or less) to high gloss images. (Glossiness of 50 or more) can be produced by a small apparatus without causing image defects, changing the rotation speed of the photoconductor, and reducing the number of image output per unit time. did it. Further, the black developer shown in Example 2 and the yellow, magenta, and cyan color developers (A-Color developer: manufactured by Fuji Xerox Co., Ltd.) are used to fix a color image during the formation by the above-described image forming apparatus. Image evaluation of a color image and a black monochromatic image at a speed of 120 mm / sec and a fixing speed of 200 mm / sec at the time of forming a black monochromatic image revealed that a high gloss image was obtained in the color image. In addition, in the black monochrome image, an image having low gloss was obtained.

[0051]

As described above, according to the present invention, by having the above-mentioned structure, it is possible to use an image forming apparatus which is small in size and does not increase power consumption. Further, without reducing the number of discharged images per unit time, From originals such as photographic images with high glossiness to general business documents with low glossiness, it is possible to obtain excellent images that do not cause fixing defects such as offset regardless of the presence or absence of glossiness, and to record. The effect is that the glossiness of the image formed on the material can be freely controlled.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of an image forming apparatus used in the present invention.

FIG. 2 is a diagram illustrating a configuration of a fixing device used in the image forming apparatus of the present invention.

FIG. 3 is a diagram illustrating a configuration of an example of a conventional image forming apparatus.

FIG. 4 is a diagram illustrating the configuration of another example of a conventional image forming apparatus.

[Explanation of symbols]

101 ... Charge holding member (photoreceptor), 102 ... Electrostatic latent image forming charger, 103 ... Developing device, 104 ... Rotating developing device, 10
5 ... Primary transfer charger, 107 ... Intermediate transfer member, 108a ...
Tension roll, 108b ... Driving roll, 109 ... Backup roll, 110 ... Bias applying roll, 11
DESCRIPTION OF SYMBOLS 1 ... Fixing device, 112 ... Paper conveying means, 113 ... Paper feeding roll, 114 ... Recording material, 115a and 115b ... Registration roll, 120 ... Laser beam scanner, 201 heating roll, 202 ... Pressure roll, 203 ... Colts lamp, 204 ... Substrate roll, 205 ... Inner elastic layer, 20
6 ... Outer elastic layer, 207 ... Substrate roll, 208 ... Inner elastic layer, 209 ... Outer elastic layer, 210 ... Recording material, 2
11 ... Toner image, 218 Colts lamp, 305 ... Primary charger, 306 ... Photoconductor, 307 ... Static eliminator, 308 ... Exposure lamp, 309 ... Development part, 310 ... Transfer drum, 31
DESCRIPTION OF SYMBOLS 1 ... Recording material, 314 ... Fixing device, 402 ... Laser scanning optical device, 403 ... Photoconductor, 404 ... First charging device, 405
... developing device, 406 ... transfer belt, 409 ... second charging device,
411 ... A fixing device.

Claims (2)

[Claims] 1. A latent image forming means for exposing at least a uniformly charged photoreceptor to form an electrostatic latent image, and a developing means for developing the electrostatic latent image with toner. An image forming method for forming an image by using an image forming apparatus having a transfer separation unit that transfers a toner image to a recording material and separates it from a toner image carrier, and a fixing unit that fixes the transferred toner image on the recording material. In the image forming apparatus, the fixing means is disposed close to the other side, and the distance between the transfer separating position of the transferring and separating means and the fixing portion of the fixing means. Is longer than the maximum length of the recording material used, and the fixing means has a heating roll and a pressure roll whose rotation speed can be changed, and the toner used is at least a resin component and a colorant. Consisting of a resin component Contains a tetrahydrofuran-insoluble polyester resin obtained by polycondensing an alcohol monomer and a carboxylic acid monomer, the molecular weight and molecular weight distribution measured by gel permeation chromatography of the resin component, Weight average molecular weight (Mw) 2
5,000 to 80,000, number average molecular weight (Mn)
2,000 to 10,000, and weight average molecular weight / number average molecular weight (Mw / Mn) of 10 or more, and the apparent melt viscosity of the toner by the flow tester method is 1 × 10.
An image forming method, wherein the temperature of ⁴ poise is 115 ° C to 140 ° C. 2. The image forming method according to claim 1, wherein the transfer separation unit of the image forming apparatus has an intermediate transfer member.