JPH1069125A - Electrophotographic developing agent, its production and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve smear property and offset property, to decrease a contamination on a photoreceptor and to improve fluidity of a developing agent by controlling the ratio of wax content in a toner particle to wax content in the whole toner to a specified value. SOLUTION: The developer has such a structure that coloring agent particles 2 and wax 3 are dispersed in a binder resin 1. The wax 3 is easily pulverized and forms an interface during pulverization compared to other source material, so that if the dispersion is bad, the amt. of the wax included in the toner decreases while the amt. of wax included in a classified fine power increases. In the method, the volume average particle size is 8 to 12μm and the amt. of wax (w) included in particles of (volume average particle size)-3μm particle size and the amt. of wax (w) in the whole toner are controlled to satisfy w/W=1.00 to 1.20. Namely, when the ratio is 1.0 to 1.2, extremely good dispensability of the wax in the toner is obtd. The nearer the ratio is to 1.0, the more uniformly the wax is dispersed in the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer for electrophotography, a method for producing the same, and an image forming apparatus using the developer, and particularly to an electrophotographic developer excellent in offset resistance, smearing property and fluidity. The present invention relates to a developer, a method for manufacturing the same, and an image forming apparatus using the developer.

[0002]

2. Description of the Related Art In an electrophotographic method using a dry development method, an electrostatic latent image formed on an image carrier, for example, a photoreceptor drum having a photoconductive layer on the surface, is developed with toner. A method in which an image is pressed and heated on a transfer material by a contact heating fixing method using a heat roll is widely used.

[0003] Toner used in such a heat fixing system
For example, Japanese Unexamined Patent Publications Nos. 60-23063 and 1-234858 disclose toners to which a polyolefin wax is added to impart releasability.

[0004] Such a toner is produced by melt-kneading a thermoplastic binder resin, a colorant mixed in the binder resin to give the resin a color, and a polyolefin wax, and further pulverizing and classifying. Is done.

However, since the polyolefin wax has a lower hardness than the binder resin, if the polyolefin wax particles in the toner are large, crushing occurs at the interface between the binder resin and the polyolefin wax particles in the pulverizing step in the above-described production method, The polyolefin wax is easily exposed on the toner surface. When the amount of the exposed wax is large, the amount of the wax included in the toner is reduced, and the dispersibility of the wax becomes sufficient. Further, since the polyolefin wax has high adhesiveness, the exposed polyolefin wax comes into contact with and adheres to the polyolefin wax exposed on the surface of another toner.

Crushing at the interface between the binder resin and the polyolefin wax occurs not only during the manufacturing process but also when the toner is stirred in the developing process. When this occurs, the toner aggregates and the fluidity of the toner decreases. When the fluidity of the toner is reduced, there is a disadvantage that the development and the transfer are not performed satisfactorily, thereby preventing the formation of a good image.

Further, in order to obtain the effect of the addition of the polyolefin wax, the content of the polyolefin wax in the toner must be considerably increased. As a result, a large amount of the polyolefin wax exposed on the surface of the toner adheres to the image carrier and the carrier to form a film, and there is a drawback that contact friction charging between the toner and the photoconductor and image formation are not performed well. .

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a developer excellent in offset resistance and fluidity.

Another object of the present invention is to provide a method for producing the above developer.

[0010]

In order to solve the above-mentioned problems, the present invention (claim 1) provides a binder resin, a colorant,
And wax, and the volume average particle size is 8 to 12 μm
Where the ratio of the wax content (w) contained in the particles (volume average particle size) -3 μm to the wax content (W) contained in the whole toner is w / W = 1.00 to 1. 20. An electrophotographic developer, wherein the developer is 20.

The present invention (claim 2) provides a binder resin,
It contains a colorant, and a wax internally added to the binder resin, has a volume average particle size of 8 to 12 μm,
(Volume average particle size) The ratio of the wax content (w) contained in the particles of −3 μm to the wax content (W) contained in the whole toner is w / W = 1.00 to 1.20. An electrophotographic developer is provided.

In the present invention (claim 3), a step of melt-kneading a colorant and a wax with a binder resin, a step of pulverizing the kneaded material, and classifying the particles obtained by the pulverization to obtain a volume average particle size of 8 A step of obtaining particles having a particle size of about 12 μm, and the kneading is performed by a ratio of a wax content (w) contained in the particles (volume average particle size) -3 μm to a wax content (W) contained in the whole toner. But w / W = 1.00-
1. A method for producing a developer for electrophotography, wherein the method is carried out so as to be 1.20.

[0013] The present invention (claim 4) provides a step of melting and kneading a colorant and a wax with a binder resin to obtain a kneaded product in which the wax is internally added to the binder resin, a step of pulverizing the kneaded product, and a step of pulverizing. A step of classifying the obtained particles to obtain particles having a volume average particle diameter of 8 to 12 μm, wherein the kneading is performed by determining the wax content (w) contained in the particles having a volume average particle diameter of −3 μm. The ratio of the wax content (W) contained in the whole toner is w / W = 1.00 to 1.00.
1. A method for producing a developer for electrophotography, wherein the method is carried out so as to be 1.20.

The present invention (claim 5) provides a developing means for developing an electrostatic latent image using a developer, a transfer means for transferring a developer image obtained by developing the electrostatic latent image to a transfer material, and A fixing unit for fixing the transferred developer image to the transfer material,
The developer contains a binder resin, a colorant, and a wax, has a volume average particle diameter of 8 to 12 μm, and has a wax content (w) contained in particles having a volume average particle diameter of −3 μm; An image forming apparatus is provided, wherein the ratio of the wax content (W) contained in the entire toner is w / W = 1.00 to 1.20.

The present invention (claim 6) provides a developing means for developing an electrostatic latent image using a developer, a transfer means for transferring a developer image obtained by developing the electrostatic latent image to a transfer material, and A fixing unit for fixing the transferred developer image to the transfer material,
The developer contains a binder resin, a colorant, and a wax internally added to the binder resin, has a volume average particle size of 8 to 12 μm, and has a volume average particle size of −3.
The ratio of the wax content (w) contained in the μm particles to the wax content (W) contained in the whole toner is w / W
= 1.00 to 1.20 is provided.

Hereinafter, the developer of the present invention will be described in detail.

The developer according to the present invention has a structure in which colorant particles 2 and wax 3 are dispersed in a binder resin 1 as shown in FIG. In this case, the wax is
Compared to other raw materials, they are easily pulverized and easily form an interface during pulverization. Therefore, if the dispersion is poor, the amount of wax included in the toner decreases, and the amount of wax included in the classified fine powder increases. In other words, the worse the classification, the larger (the wax content in the fine powder) / (the wax content in the toner).

If the dispersion of the wax in the toner is poor, as described above, the fixing performance is reduced, and the floating wax causes contamination (black spots) on the photosensitive drum and deterioration of the charging property. .

The inventor has determined that the ratio of the wax content of the fine powder, i.e., particles having a particle size of (toner average particle size-3 μm) / the wax content in the toner, is a measure of the dispersion of the wax in the toner. It has been found that the present invention can be performed, and the present invention has been accomplished.

That is, when the above ratio is 1.0 to 1.2, extremely good wax dispersibility in toner is exhibited.

The closer the ratio is to 1.0, the more uniformly the wax is dispersed in the toner, and the more ideally the dispersion state is.

(1) Improvement of smearing property Smearing property means that when a copied document is passed through an automatic document feeder, image contamination may occur due to pressure and friction of a separation belt. Call
According to the toner of the present invention having good wax dispersibility, such smear property is improved.

The automatic document feeder has a structure as shown in FIG. That is, the transport belt 13 stretched between the pair of rollers 12a and 12b on the original glass 11.
Are arranged, and on the side of the roller 12a, an aligning roller 14, a sheet feeding roller 15, and a pickup roller 1 are further provided.
6. The document table 17 is sequentially arranged. In addition,
A separation belt 18 is provided to face the roller 15. On the side of the roller 12b, a reversing roller 19 and a flapper 2 are provided.
0, a paper discharge roller 21 is provided.

With the automatic document feeder having such a structure, automatic feeding of a document is performed as follows. First, the document on the document table 17 is taken out by the pickup roller 16 and is fed onto the document glass 11 by the separation belt 18, the sheet feeding roller 15 and the aligning roller 14. The original sent to the original glass 11 is conveyed to a predetermined position on the original glass 11 by the conveyor belt 13, where copying is performed.

After the copying is completed, the original is discharged to a discharge tray via a discharge roller 20. When copying a two-sided original, the original is guided to the reversing unit by switching the flapper 20, and the original is inverted and sent to the original glass 11 again.

(2) Improvement of Offset Property The offset property is correlated with the back stain property, and the toner of the present invention is particularly excellent in the back stain property. The back stain property is a characteristic indicating the degree of stain on the back surface of the paper that has been passed after a predetermined number of copies have been made.

(3) Reduction of photoreceptor contamination (black spot, filming property) It was found that the toner of the present invention can reduce the contamination of the photoreceptor by wax (black spot on the image).

(4) Improvement of Fluidity The toner of the present invention has improved fluidity.
The transportability is improved, carrier adhesion is reduced, and a decrease in image density is prevented.

The toner of the present invention described above is manufactured as follows.

First, 100 parts by weight of a binder resin, 1 to 10 parts by weight of a coloring agent, and 1 to 10 parts by weight of a wax are mixed and dispersed using a ball mill, a V-type mixer or the like. Next, heat melting and kneading are performed using a pressure kneader, a roll, or the like. The obtained mixture is roughly pulverized using a hammer mill, a jet mill or the like. Next, the present invention is pulverized using a jet mill or the like, and then classified into a desired particle size by an air classification method or the like, and finally mixed with an external additive using a high-speed fluidizing mixer or the like, according to the present invention. Toner particles are obtained.

In this case, the dispersibility of the wax is affected by the kneading conditions. Preferred kneading conditions are as follows: when a twin-screw extrusion kneader is used, the cylinder temperature is 70 to 90.
° C, material feed amount 30-70Kg / h, screw
The rotation speed is 80 to 150 rpm.

The wax is introduced during the production of the resin,
By adding the resin internally, good dispersibility can be obtained.

Examples of the binder resin used in the toner of the present invention include styrene resins, that is, polymers or copolymers of styrene monomers. That is, it is a polymer or copolymer of one or more styrene monomers, or a copolymer of a styrene monomer and another vinyl monomer.

Specific examples of the styrene monomer include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-methylstyrene and p-methylstyrene. -N-butylstyrene, p-tert-butylstyrene, pn
-Hexylstyrene, pn-octylstyrene, p-
n-nonylstyrene, pn-decylstyrene, pn
-Dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene and the like.

Examples of the copolymer of a styrene monomer and a vinyl monomer include a styrene-butadiene copolymer and a styrene-acryl copolymer. Here, as the acrylic monomer for the acrylic component, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl methyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
N-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Aminoethyl,
There are α-methylene aliphatic monocarboxylic esters such as diethylaminoethyl methacrylate. Still other acrylic monomers include acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonilyl, and acrylamide, and these monomers can be used alone or by selecting two or more kinds. .

In addition to the above, polyester resin, epoxy resin and the like may be used as the binder resin.

The waxes usable in the toner of the present invention include polyolefin waxes. Examples of the polyolefin wax include a homopolymer obtained from a single olefin monomer and a copolymer obtained by copolymerizing an olefin monomer with another monomer copolymerizable therewith.

Examples of the olefin monomer include ethylene, butene 1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, and their isomers having different unsaturated bond positions. And those having a branched chain comprising an alkyl group thereon, such as 3-methyl-1-butene, 8-methyl-2-pentene, 3-propyl-5-methyl-2-hexene, all other olefins Monomer.

Other monomers copolymerizable with the olefin monomer include, for example, vinyl methyl ether,
Vinyl ethers such as vinyl-n-butyl ether and vinyl phenyl ether; vinyl esters such as vinyl acetate and vinyl butyrate; and halo such as vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, vinyl chloride, vinylidene chloride and tetrachloroethylene. Olefins, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, stearyl methacrylate, N, N-dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate And methacrylic esters such as acrylonitrile and N, N-dimethylacrylamide such as acrylic acid. Acid, methacrylic acid, maleic acid, fumaric acid, organic acids such as itaconic acid, diethyl fumarate, beta-Binen etc., can be mentioned various ones.

Further, as a useful wax, a modified polyolefin obtained by blocking or grafting the above-mentioned polyolefin with other components can also be used.

The modifying components in this case include, for example, styrene, p-methylstyrene, α-methylstyrene,
Aromatic vinyl monomers such as 4-dichlorostyrene or unsaturated fatty acid monomers such as acrylic acid, methacrylic acid, ethyl acrylate and methyl methacrylate and esters thereof are useful.

The amount of the polyolefin wax added to the toner is preferably 0.5 to 10.0 parts by weight, more preferably 0.5 to 6.0% by weight. When the amount of the polyolefin wax is less than 0.5% by weight, the effect of preventing the offset development is not recognized. On the other hand, when the amount exceeds 10% by weight, it is impossible to prevent a large amount of the polyolefin wax from being exposed on the surface of the toner particles. Absent.

Colorants usable in the toner of the present invention include carbon black, nigrosine dye, aniline blue, coco oil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride and phthalocyanine. Blue, Malachite Green Oxalate, Lamp Bengal and the like. These colorants can be used alone or as a mixture. The amount of the colorant added is preferably 1 to 5% by weight in the toner.
If the amount is less than 1% by weight, the amount of the colorant is insufficient, so that the colorant cannot function. Addition of more than 5 parts by weight is not preferable because the colorant aggregates and lowers the chargeability and fluidity of the toner.

A charge controlling agent is further added to the toner of the present invention. As the charge control agent, a nigrosine-based charge control agent can be used. In addition, a positive or negative charge control agent can be added to the toner as needed. Nigrosine, carbon number 2 to 16
Azine-based dyes, basic dyes and lake pigments of the basic dyes. C.I. Eye. basic. Yellow 2, Sea. Eye. basic. Red 1, Sea. Eye. basic. Red 9, Sea. Eye. basic. Violet 1 and the like.

Examples of the basic dye laker include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide and ferrocyanide. Other charge control agents for controlling the toner to the positive electrode include C.I. Eye. Solvent. Black 3. Hansaier-G, See. Eye. Moldite. Black 11, Sea. Eye. Pigment. Black 1, Gilsonite, Asphalt,
Polyacin resins such as amino group-containing vinyl polymers, amino group-containing condensation polymers, etc. and organic tin compounds such as quaternary ammonium salts, benzyl dimethyl-hexadecyl ammonium chloride, decyl trimethyl ammonium chloride and dibutyl tin oxide ,
Inorganic fine powders such as metal salts of higher fatty acids, glass, mica, zinc oxide, and metal complexes of acetylacetone.

Among the charge control agents, those which control the toner to the negative electrode include metal complexes of monoazo dyes, nitrohumic acid and salts thereof. Other examples include salicylic acid, naphthoic acid, metal complexes of dicarboxylic acid such as iron, chromium and iron, sulfonated copper phthalocyanine pigments, styrene oligomers having nitro and halogen groups introduced, chlorinated paraffin and melamine resins.

The toner of the present invention can be variously deformed by using the binder resin, the colorant, the polyolefin wax, the charge controlling agent and the like described above, and can also contain a magnetic component in the toner and a lubricant for improving fluidity. May be added. Examples of the lubricant for improving fluidity include colloidal silica powder and fluororesin powder.

The toner of the present invention is mixed with a carrier selected from iron powder, ferrite, glass beads and the like to form a two-component developer, but can be used as it is as a one-component developer.

[0049]

Embodiments of the present invention will be described below with reference to the drawings.

First, a toner according to an embodiment of the present invention is described.
FIG. 1 shows an outline of a copying machine using the above.

As shown in FIG. 3, a drum-shaped photosensitive member 103 as an image carrier is rotatably provided in a substantially central portion of the copying machine main body 101 (hereinafter referred to as the main body 101) in a direction indicated by an arrow a. ing. The photoconductor 103 has a photoconductive layer on the surface. Around the photoconductor 103, the following devices are fixed along the rotation direction.

That is, the charging charger 105 for uniformly charging the surface of the photosensitive member 103 and the charging charger 105
A slit glass 107 for slit exposure of the original image as a light image on the charged photoconductor 103 is provided above the photoconductor 103 on the downstream side in the rotation direction of the photoconductor 103.

Further, a developing device 109 is provided downstream of the slit glass 107 for developing the electrostatic latent image on the photosensitive member 103 by attaching toner to the electrostatic latent image.
09 contains a toner 110 according to the present invention mixed with a carrier as a developer. In the developing device 109, there are provided a stirring roller 201 for stirring the developer by the rotation of the roller to frictionally charge the developer, and a supply roller 202 for supplying the developer stirred by the stirring roller 201 to a magnet roller 203 described below.

Further, a magnet roller 203 in which an S pole and an N pole are alternately arranged inside the developing device 109 along the rotation direction of the roller is rotatable in a direction indicated by an arrow 1 in a state approaching the photosensitive member 103. It is provided in. A transfer device 111 and a peeling device 11 are located downstream of the developing device 109.
3 are provided.

The transfer device 111 transfers the toner image formed by the developing device 109 onto a copy sheet (hereinafter, referred to as a sheet).
The sheet adsorbed on the surface of the photoconductor 103 by the
03 is a device that separates from the surface. Downstream of the peeling device 113, the toner 110 adhering to the surface of the photoconductor 103
Of the photoconductor 1 after the transfer by the transfer device 111 is performed.
A cleaning device 115 for removing the toner 110 remaining on the surface 03 is provided.

A static eliminator 117 for lowering the potential of the photosensitive member 103 is fixedly provided between the cleaning device 115 and the charger 105.

The main body 101 illuminates the original glass 119 on which the original is to be placed and the original on the original glass 119, and guides the reflected light onto the surface of the photosensitive member 103.
21. The optical system 121 is a lamp 1 serving as a light source.
23 and mirrors 124, 125, 127, 129, 131, 133 for reflecting light emitted from the light source, and a lens unit 135 for imaging the reflected light.

The lamp 123 and the mirror 124 are configured to be movable under the original glass 119, and the mirror 125 and the mirror 127 are maintained so that the optical path length is always kept constant.
Is configured to move at half the speed of the ramp 123. The light reflected from the mirror 133 is transmitted through the slit glass 107 and guided to the surface of the photoconductor 103.

A manual tray 141 for storing paper is detachably provided in the middle section on the right side of the main body 101. The paper stored in the manual tray 141 is located above the tip of the manual tray 141 in the main body 101. A pickup roller 143 for pulling out an image is provided.

On the left side of the main body 101, there is provided a paper discharge tray 171 for discharging the copied paper.
Between the manual feed tray 141 and the discharge tray 171,
A paper transport path, that is, a transport path 142 is formed, and the transport path 142 is indicated by a dotted line in FIG.

Upstream of the transport path 142, first and second two pairs of rollers are attached to the main body 101. The first roller pair is adjacent to the manual feed tray 141 and includes two rollers, a paper feed roller 145 and a separation roller 147. The paper feed roller 145 is a roller that is rotatable in the direction of arrow b in the figure and that feeds the paper drawn by the pickup roller 143 to the second pair of rollers by rotation of the roller.

The separation roller 147 is provided so as to be in contact with and beneath the sheet feeding roller 145. When the number of sheets sent from the pickup roller 143 is two or more, the direction opposite to the rotation direction of the sheet feeding roller 145 is used. To return the extra paper to the manual feed tray 141. The separation roller 147 is rotated by the rotation of the sheet feeding roller when the number of sheets sent from the pickup roller 143 is one.

The second roller pair is a registration roller 149 composed of an upper roller and a lower roller. The registration roller 149 strikes the leading edge of the paper sent from the paper feed roller 145 to align the paper, and places the aligned paper on the photoconductor 103 between the photoconductor 103 and the transfer device 111. Of the toner image.

In the middle of the transport path 142, the transfer device 11
1 and a peeling device 113, and a belt-like belt for transporting paper, that is, a transport belt 1
51 are provided. Further, on the downstream side of the transport path 142 in the transport direction, the toner 110 is heated and pressurized to
A fixing device 153 for fixing 10 on paper is provided. The fixing device 153 includes a heater roller 157 and a pressure roller 15 rotatable in directions indicated by arrows c and d, respectively.
9.

The heater roller 157 has a built-in heater lamp 155 as a heating element and is partially pressed against the pressure roller 159. The surface of the heater roller 157 is made of a metal member having good heat conductivity, and the surface of the pressure roller 159 is made of an elastic rubber member so as to be easily pressed against the heater roller 157.

Further, a discharge roller 161 for discharging the paper carrying the copy image onto the discharge tray 171 is provided downstream of the fixing device 153 in the transport direction.

The copying process in the main body 101 described above is as follows.

First, the surface of the photosensitive member 103 is uniformly charged by corona discharge of the charging charger 105. Next, the lamp 123 in the optical system 121 scans under the original glass 119 on which the original is placed, and the original is irradiated with light. The mirror 124 moves under the original glass together with the lamp 123, and the mirror 124 is moved to a mirror 124A indicated by a broken line in FIG.
Mirror 125 and mirror 127 move to mirrors 125A and 127A, which are located just halfway between mirror 124 and mirror 124A.

When scanning is performed while keeping the optical path length constant, the light emitted from the lamp 123 is reflected from the mirror 124 to the mirror 125, from the mirror 125 to the mirror 127, and from the mirror 127. The light is guided to the lens unit 135. Lens unit 1
At 35, the reflected light is inverted and guided to mirror 129.

The inverted light is transmitted from the mirror 129 to the mirror 13
1. The light is guided from the mirror 131 to the mirror 133. This light is further guided from the mirror 133 to the slit glass 107, and is charged through the slit glass 107.
03 is exposed. When the light is exposed, an electrostatic latent image is formed on the surface of the photoconductor 103.

In the developing device 109, the stirring roller 201
The toner 110 and the carrier, which have been frictionally charged by the stirring, are sent to the magnet roller 203 by the supply roller 202. The toner 110 and the carrier sent onto the magnet roller 203
A magnetic brush is formed by magnetic lines of force formed between the poles and the N pole.

The carrier is always attracted to the magnet roller 203 by magnetism, and the toner 110 is electrically attracted to the carrier. When the magnet roller 203 and the photoconductor 103 rotate and the magnetic brush and the electrostatic latent image on the photoconductor 103 approach each other, the toner 110 is separated from the carrier by a stronger electrostatic attraction of the electrostatic latent image. Attaches to electrostatic latent image. The toner 110 attached to the electrostatic latent image forms a toner image. At the time of development, a voltage of about 200 V DC is applied to the magnet roller 203 by a voltage device (not shown) to prevent fogging due to unnecessary adhesion of the toner 110.

On the other hand, the paper stored in the paper feed cassette 141 is pulled out by a pickup roller 143, and the paper feed roller 145 and the separation roller 1 of the pulled out paper are pulled out.
47 rotates only one sheet of paper to the registration roller 14.
It is sent to 9. The registration roller 149 aligns the leading edge of the paper, sends the paper between the photoconductor 103 and the transfer device 111, and superimposes the paper on the electrostatic latent image on the photoconductor 103.
When a charge having a polarity opposite to that of the toner is applied from the transfer device 111 to the back side of the fed paper, the toner image is transferred onto the paper by electrostatic attraction.

The paper on which the toner image has been placed in this manner is peeled off from the surface of the photosensitive member 103 by the peeling device 113, and
It is transported on the magnetic belt 151. The transported paper reaches the fixing device 153. In the fixing device 153, the heater roller 157 heated by the heater lamp 155 incorporated in advance and the pressure roller 159 rotate in respective rotation directions while partially pressing.

At the time of rotation of the heater roller 157 and the pressure roller 159, the toner image is fixed on the paper by passing the paper through the pressed portion of the two rollers so that the toner image is on the heater roller 157 side. That is, the toner 110 is melted by the heat of the heater roller 157, the heat transfer efficiency is increased by the pressure of the pressure roller 159, and the toner is soaked between the fibers of the paper.

The paper on which the copy image has been formed through the above-described process is discharged to the paper discharge tray 171 via the paper discharge rollers 161.

Next, examples of the present invention and comparative examples will be described.

Prior to the description of each example, the evaluation method used will be described.

(1) Smearing property Using a predetermined test chart, a letter made by Hammer Mill was used.
After fifty images have been printed on the size paper, the paper is passed through the automatic document feeder. In this case, the image stain is generated due to the pressure, friction, and the like of the separation belt.

A: Almost no image dirt B: Slight image dirt but no problem B: Image dirt is remarkable (2) Offset property The offset property was evaluated by the back stain property shown below.

When the paper of the reja size is ID 0.6 to 0.8
After passing 50 sheets of paper, 10 blank sheets (reja size) were taken. At that time, the stain on the back side of the paper was observed, and the stain on the back was evaluated according to the following criteria.

◎: Almost no dirt ○: Slight dirt but no problem ×: Dirt is remarkable (3) Photoreceptor contamination Adhesion of toner particles on the drum after 20K life (drum filming) The number of defects (black spots) that appeared on the image when white background was printed on A3 paper was counted for one rotation of the drum, and the photoconductor contamination was evaluated based on the following criteria.

◎: No filming occurred. ：: Filming occurred, but there was no problem on the image. Δ: Filming occurred, number of defects (black spots) 10 or less /
A3 ×: occurrence of filming, number of defects (black spots) 11 or more / A
3 (4) Fluidity A test was performed according to JIS Z2502, and evaluated according to the following criteria.

◎: Very good (60 seconds or less) ：: Good (60 to 70 seconds) △: During measurement, the developer stopped flowing and when tapped, the state of flowing again ×: The developer stopped flowing and was tapped A state in which the fluid stops flowing The toner used in the above-described electrophotographic apparatus will be described.

Example 1 A resin containing wax therein was produced in the following manner. That is, first, the following components were sufficiently mixed with a sand stirrer.

85 parts of styrene 15 parts of n-butyl acrylate 15 parts of azobisisobutyronitrile (AIBN) (polymerization initiator) 0.4 parts of wax (a) 5 parts A flask containing isopropanol as a reaction solvent was prepared. The above mixture was added with stirring.

Thereafter, the temperature was raised to 60 ° C., and the polymerization reaction was continued for 8 hours. After the completion of the polymerization reaction, the resultant was cooled, dehydrated, washed and dried to obtain a styrene acrylic copolymer resin containing wax therein. The wax (a) used was a polypropylene wax 660P manufactured by Sanyo Chemical Industries, Ltd. The resulting resin had M _w = 180,000, M _n = 17000,
M _w / M _n = 10.59.

93 parts by weight of the styrene acrylic copolymer resin obtained as described above, and MA-
100 (manufactured by Mitsubishi Kasei) and 2 parts by weight of P-51 (manufactured by Orient Chemical Industries) as a charge controlling agent are uniformly dispersed by a Henschel mixer, and the cylinder temperature is 80 ° C. by a twin-screw extrusion kneader. , Material feed amount 50
The melt kneading was performed under the conditions of kg / h and a screw rotation speed of 100 rpm. Then, it is finely pulverized by a jet mill, pulverized and classified by air classification, and has a volume average particle diameter (D ₅₀ ) of 10 μm.
m of toner A was obtained. The wax content of this toner A was W _A = 5.1%.

Next, the toner A was charged with a volume average particle diameter (D ₅₀ ).
There volume average particle diameter (D ₅₀₎ of Toner A re classified as consisting -3Myuemu, to obtain a volume average particle diameter (D ₅₀₎ 7 [mu] m in the toner A '. The wax content of this toner A ′ was w _A = 5.3.
%Met.

As a result, W _A / w _A = 1.04.

The wax content was determined by measuring the heat of fusion of a DSC (differential scanning calorimeter).

A two-component developer is prepared by mixing the toner A with a silicon coat carrier (average diameter 70 μm) manufactured by Powdertech Co., Ltd., and this is used to make a copy machine BD-2510 manufactured by Toshiba.
And the smear property, offset property, photoreceptor contamination, fluidity, etc. were evaluated. The results are shown in Table 1 below.

Example 2 CPR 600B as a styrene acrylic copolymer resin
88 parts by weight (manufactured by Mitsui Toatsu Chemicals), 5 parts by weight of biscol 660P (manufactured by Sanyo Chemicals) as a polypropylene wax, 5 parts by weight of MA-100 (manufactured by Mitsubishi Kasei) as carbon black, and P-51 as a charge control agent 2 parts by weight (manufactured by Orient Chemical Industry Co., Ltd.) are uniformly dispersed by a Henschel mixer, and a cylinder temperature (C ₁ -C ₈ ) is 80 ° C., a material feed amount is 50 kg / h by a twin screw extruder.
Melt kneading was performed under the conditions of a screw rotation speed of 100 rpm. Thereafter, the mixture was finely pulverized by a jet mill, and pulverized and classified by air classification to obtain a toner B having a volume average particle diameter (D ₅₀ ) of 10 μm. Wax content of the toner A is W _B =
It was 5.2%.

Next, the toner A was charged with a volume average particle diameter (D ₅₀ ).
There volume average particle diameter (D ₅₀₎ of Toner A re classified to be -3Myuemu, volume average particle diameter (D ₅₀₎ 7 [mu] m in the toner A '
I got The wax content of this toner A ′ is w _B = 6.
It was 0%.

As a result, W _B / w _B = 1.20.

The toner B is mixed with a silicon-coated carrier (average diameter 70 μm) manufactured by Powdertech Co., Ltd. to prepare a two-component developer.
And the smear property, offset property, photoreceptor contamination, fluidity, etc. were evaluated. The results are shown in Table 1 below.

Comparative Example 1 Toner C was obtained in the same manner as in Comparative Example 1, except that the shilling temperature during kneading was (C ₁ -C ₈ ) 120 ° C. The wax content of this toner C is W _C = 4.9%.
The wax content of _{C ′} was w _C = 6.4%.

As a result, w _C / W _C = 1.31.

A two-component developer is prepared by mixing the toner C with a silicon-coated carrier (average diameter 70 μm) manufactured by Powdertech Co., Ltd., and using this, a copier BD-2510 manufactured by Toshiba.
And the smear property, offset property, photoreceptor contamination, fluidity, etc. were evaluated. The results are shown in Table 1 below.

Comparative Example 2 A toner D was obtained in the same manner as in Comparative Example 1 except that the screw rotation speed during kneading was 300 rpm. Wax content of the toner -D is W _D = 5.0%, wax content of toner -D 'was w _D = 7.5%.

As a result, w _D / W _D = 1.50.

A two-component developer is prepared by mixing the toner C with a silicon-coated carrier (average diameter 70 μm) manufactured by Powdertech Co., Ltd., and using this, a copier BD-2510 manufactured by Toshiba.
And the smear property, offset property, photoreceptor contamination, fluidity, etc. were evaluated. The results are shown in Table 1 below.

[0103]

[Table 1]

As is clear from Table 1 above, the toner (Example 1) whose w / W falls within the range of the present invention is very excellent in any property, whereas w / W is the present invention. (Comparative Examples 1 to 3) are inferior in characteristics to toners within the scope of the present invention.

FIG. 4 shows the volume average particle size of toner -3 (μm).
The dispersibility of the wax in the toner when the ratio (w / W) of the following wax content w in the toner and the content W of the wax in the whole toner was variously changed was examined. The results are shown. FIG. 4 shows that when the ratio (w / W) is 1.2 or less, the dispersibility is excellent.

[0106]

As described above, according to the present invention,
Since the ratio of the wax content (w) contained in the particles having a volume average particle diameter of -3 μm or less to the wax content (W) contained in the entire toner is in the range of 1.0 to 1.20. As a result, the dispersion state of the wax contained in the toner is ideal, and as a result, excellent effects such as improvement of smearing property, improvement of offset property, reduction of photoconductor contamination, and improvement of developer fluidity are obtained. You can have a child.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a toner containing a polyolefin wax.

FIG. 2 is a diagram illustrating a structure of an automatic document feeder.

FIG. 3 is a sectional view of a copying machine used in the embodiment.

FIG. 4 shows various changes in the ratio (w / W) of the wax content w of the toner having a volume average particle diameter of −3 (μm) or less to the wax content W of the entire toner. FIG. 4 is a characteristic diagram showing the dispersibility of wax in toner when it is made.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Binder resin 2 ... Colorant 3 ... Polyolefin wax 11 ... Original glass 12a, 12b ... Roller 13 ... Conveying belt 14 ... Aligning roller 15 ... Feeding roller 16 ... Pickup roller 17 ... Original Table 18: Separation belt 19: Reversing roller 20: Flapper 21: Discharge roller 101: Copy machine body 103: Photoconductor 105: Charger 107: Slit glass 109: Developing device 110: Toner 111: Transfer device 121: Optical system 153: Fixing device. 201: stirring roller

Claims (6)

[Claims] 1. A wax content (w) contained in particles having a volume average particle size of 8 to 12 μm and a volume average particle size of −3 μm, comprising a binder resin, a colorant, and wax; An electrophotographic developer, wherein the ratio of the wax content (W) contained in the whole toner is w / W = 1.00 to 1.20. 2. The composition contains a binder resin, a coloring agent, and a wax internally added to the binder resin, has a volume average particle size of 8 to 12 μm, and has a volume average particle size of −3.
The ratio of the wax content (w) contained in the μm particles to the wax content (W) contained in the whole toner is w / W
= 1.00 to 1.20, an electrophotographic developer. 3. A step of melt-kneading a colorant and a wax into a binder resin, a step of pulverizing the kneaded material, and classifying the particles obtained by the pulverization to obtain a volume average particle diameter of 8 to 10.
The kneading includes a step of obtaining particles of 12 μm, and the kneading is performed so that the ratio of the wax content (w) contained in the particles (volume average particle size) −3 μm to the wax content (W) contained in the whole toner is , W / W = 1.00 to 1.20, the method for producing an electrophotographic developer. 4. A step of melting and kneading a colorant and a wax into a binder resin to obtain a kneaded product in which the wax is internally added to the binder resin, a step of pulverizing the kneaded product, and classifying particles obtained by the pulverization. And a volume average particle size of 8 to 1
A step of obtaining particles of 2 μm, wherein the kneading is performed by (volume average particle size) —the content of wax (w) contained in the particles of −3 μm and the content of wax (W) contained in the entire toner.
Wherein the ratio of w / W is 1.00 to 1.20. 5. A developing means for developing an electrostatic latent image using a developer, a transferring means for transferring a developer image obtained by developing the electrostatic latent image to a transfer material, and a developing means for transferring the transferred developer image. A fixing unit for fixing to a transfer material, wherein the developer contains a binder resin, a colorant, and a wax, has a volume average particle diameter of 8 to 12 μm, and has a volume average particle diameter of −3 μm
The ratio of the wax content (w) contained in the particles of the toner to the wax content (W) contained in the whole toner is w / W =
An image forming apparatus, wherein the number is from 1.00 to 1.20. 6. A developing means for developing an electrostatic latent image using a developer, a transfer means for transferring a developer image obtained by developing the electrostatic latent image to a transfer material, and a method for transferring the transferred developer image to a transfer material. A fixing unit for fixing to the transfer material, wherein the developer contains a binder resin, a colorant, and a wax internally added to the binder resin, and has a volume average particle diameter of 8 to 12 μm.
m, and the ratio of the wax content (w) contained in the particles (volume average particle size) -3 μm to the wax content (W) contained in the whole toner is w / W = 1.00-1. .20
An image forming apparatus characterized in that: