JPH05224454A - Electrophotographic toner and its production - Google Patents

Abstract

PURPOSE:To provide an electrophotographic toner and its production for an image forming device to form toner images on a photosensitive body by exposing and developing the picture images at one time from the back surface of the photosensitive body, and to stably form good picture images without irregular density state. CONSTITUTION:This toner is used for the developing method described below. The toner is supplied in the upstream side of a triboelectric member pressed to the surface of a developer carrier which rotates and touches a photosensitive body. This photosensitive body rotates at a certain speed. The toner is electrified on the triboelectric member and carried by the developer carrier body to the contact area of the photosensitive body to develop images on the photosensitive body. To this toner, a ferroelectric material is internally added by 10-70 pts.wt. or externally added by 10-30 pts.wt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner used in an image forming apparatus which obtains a toner image on a photoconductor by exposing the photoconductor from the backside of the photoconductor and developing the image at the same time. Current copiers or high-speed, high-print quality printers use electrophotographic recording methods.
It is common. This method uses a photoconductor as a recording medium,
This is the so-called Carlson process in which recording is performed in seven steps: uniform charging, image exposure, development, transfer, fixing, charge removal, and cleaning.

In the Carlson process, a corona discharger is used for uniform charging, transfer and charge removal. Corona discharger is several k
Since it is configured to apply a high voltage of V to the corona wire,
Since it requires a high-voltage power supply and is easily affected by humidity and dust, it has the disadvantage of low reliability. Also,
Ozone generated in a corona discharger produces an odor, and in recent years, ozone has become a problem for humans.

Further, since the above-mentioned seven steps are required, there is a drawback that the apparatus becomes complicated and the size becomes large. In view of the above-mentioned problems, a three-image forming method has recently been proposed, which requires no corona discharger and focuses on downsizing of the apparatus.
Specifically, it is a system in which a toner developing machine and an image exposure means are arranged opposite to each other with a photoconductor interposed therebetween, and image exposure and development are performed simultaneously.

[0004]

2. Description of the Related Art As a conventional image forming method, for example, FIG.
There is something like. In FIG. 6, the photoreceptor 7 is composed of a transparent substrate 7A, a transparent conductive layer 7B, and a photoconductive layer 7C, and the transparent conductive layer 7B is connected to the ground. The developing device provided on the photoconductive layer 7C side of the photoconductor 7 includes a developing roller 14 for developing the toner 3 on the photoconductor 7 and the photoconductor 7.
It has a collecting roller 1 for collecting the toner 3 other than the upper image portion. The developer 4 is a two-component developer in which a non-magnetic toner 3 and a conductive carrier are mixed, and is conveyed on a developing roller 14 composed of a sleeve of a metal cylinder and a magnet inside the sleeve. On the transparent substrate 7A side of the photoconductor 7,
The image exposure means 8 is arranged. The image exposure unit 8 is arranged so as to face the developing roller 14. As the image exposure means 8, an LED array optical system, a laser optical system, an EL
An optical system, a liquid crystal shutter optical system, etc. can be used. In addition,
Reference numeral 2 is a recovery blade, 5 is a paddle roller, 6 is a doctor blade, 9 is a charge eliminating lamp, 11 is a heat roller, 12 is recording paper, and 13 is a transfer roller.

Next, FIG. 7 shows an image forming principle. When the photoconductive layer 7C is imagewise exposed in the developing roller portion of the apparatus having the above structure, electron-hole pairs are generated in the photoconductive layer 7C. The applied voltage of the electron-hole pair to the developing roller 14 (+100 to +
A charge (negative charge) having a polarity opposite to that of 600 V moves to the surface of the photoconductive layer 7C and becomes a latent image charge. In this way, in the exposed portion, the electrostatic capacity of the photoconductive layer 7C apparently increases, so that the amount of adhered toner increases, and a toner image with a certain degree of contrast is formed between the exposed portion and the non-exposed portion. This process is called the first development.

Next, in the collecting roller unit, a reverse voltage (0 to -100V) is applied to the collecting roller 1 to collect the excess toner 3 in the non-exposed portion to the developing device by electrostatic force. At this time, the toner 3 in the exposed portion is also slightly recovered, but most of the toner 3 is due to the electrostatic binding force of the latent image charge and the toner charge.
Remain on the photoconductor 7 and a toner image is formed. This step is called second development.

[0007]

In such a conventional image forming method, the latent image charge directly affects the print density. In order to form a latent image charge, it is necessary that a sufficient voltage is applied to the photoconductive layer during image exposure. Amorphous on photoconductor using normal toner (ε = 3)
When a silicon photoconductor is used, its electrostatic capacity is large (α-Si: ε = 12), so that an electric field is not easily applied to the photoconductor drum in a thin film state, and a latent image is hard to be formed on the photoconductor drum. Therefore, it is necessary to form a latent image with a high bias (800V). However, under a high bias, leakage from the photoconductor or the layer thickness regulating member has been a problem.

When a developing bias is applied between the metal sleeve and the transparent conductive layer of the photoconductor from the device side, the voltage applied to the photoconductive layer depends on the distance between the photoconductor and the sleeve and the resistance of the developer. To be done. In this method, in which the two-component developer is placed on the metal sleeve and conveyed, the distance between the photosensitive member and the sleeve is as wide as about 1.0 mm, which makes it difficult to apply a voltage, and the resistance of the developer due to fluctuations in the toner concentration of the developer. There is a change in value. When the resistance value of the developer changes, the voltage applied to the photoconductive layer also changes, so the amount of latent image charge generated also changes. There has been a problem that this change in latent image charge appears as density unevenness.

The present invention has been made in view of the above conventional problems, and provides an electrophotographic toner capable of stably forming a good image without uneven density and a method for producing the same. The purpose is to do.

[0010]

In order to achieve the above-mentioned object, the present invention provides a photoreceptor comprising a transparent substrate, a transparent or semitransparent conductive layer and a photoconductive layer, and a photoconductive material of the photoreceptor. A developer holder for developing the developer on the photoconductor, a collecting means for collecting the developer other than the image area on the photoconductor, and a conductive material for the photoconductor. An image forming apparatus, which is provided on the layer side and at a position facing the developing means, and includes an image exposing means for performing image exposure, is used. Toner is supplied on the upstream side of the frictional charging member that is in contact with the outer periphery of the body, the toner is charged by the frictional charging means, and the toner is conveyed by the developer holding member to the pressure contact portion with the photosensitive body. It is used in the developing method of developing on top, and the ferroelectric substance is added to the toner.
˜70 parts by weight, or 10 to 30 parts by weight of a ferroelectric substance is externally added to the toner. Hereinafter, the present invention will be specifically described.

FIG. 1 shows the basic principle of the developing section. Since toner intervenes between the photoconductor and the developer holder, the bias applied to the photoconductor is expressed by the following equation when the toner layer thickness is dp.

[0012]

[Equation 1]

Here, Vo: developing bias Vp: bias applied to the photoconductor Cp: photoconductor capacitance εp: photoconductor relative permittivity dp:
Thickness of photoconductor Cp = (εp / dp) × εo Ct: Toner layer capacity Ct = (εt / dt) × εo Ct: Toner capacity εt: Toner dielectric constant d
t: Toner layer thickness εo: Dielectric constant of vacuum From equation (1), if the characteristics of the photosensitive member are not changed in order to increase the bias applied to the photosensitive member, (i) increase the relative dielectric constant of the toner or ( ii) There is a method of reducing the toner layer thickness.

In the main development, for example, as a developer, 10
In the case of using a μm toner and press-contacting the developer holder and the photoreceptor, the following method was used to achieve (i). There are two to four toner layers (about 20-40 μm) on the roller surface.
m) is formed and developed. Further, since the capacity of the photoconductor is constant, in order to increase the bias applied to the photoconductor, it is necessary to increase the capacity of the toner layer, that is, the relative dielectric constant of the toner from the equation (1). When the relative permittivity of the toner is small, a latent image is not formed on the photoconductor unless a large developing bias is applied. Therefore, a ferroelectric substance was added to the toner to improve the dielectric constant of the toner. If you do this,
A voltage is very easily applied to the photoconductive layer, and latent image charges can be stably formed. In this case, the lowest bias for forming a latent image on the photoconductor will be referred to as the lowest latent image bias.

Further, as a ferroelectric substance for improving the dielectric constant of the toner, barium titanate, strontium titanate, lead titanate, lithium titanate, potassium titanate, bismuth titanate, calcium titanate, titanium oxide, alumina, Lithium niobate, potassium niobate,
Although fine powders of sodium niobate, lead zirconate, beryllium zirconate and solid solutions thereof can be used, a plurality of them may be used in combination. Also,
Although barium titanate has a high dielectric constant among the above compounds, it is more preferable that it contains impurities such as Ca and Mn, has a low Curie temperature, and has a maximum peak of the dielectric constant at room temperature (0 to 40 ° C.). These ferroelectric substances may be internally added to the toner or externally added, but the following methods may be used to internally add the ferroelectric substance to the toner. (1) A method of producing a toner by dispersing a colorant and a ferroelectric substance in a radically polymerizable vinyl monomer and then suspension-polymerizing the toner. (2) A colorant is dispersed in a radical-polymerizable vinyl monomer and then emulsion-polymerized, and the ferroelectric substance is dispersed in the emulsion-polymerized product, which is built up together with the ferroelectric substance. Toner is manufactured. (3) A method of producing the toner by using a thermoplastic resin as a binder resin, kneading, pulverizing and classifying the resin, the colorant and the ferroelectric substance.

Further, there are the following methods for externally adding the ferroelectric substance to the toner. (1) A method of electrostatically adhering fine particles of a ferroelectric substance to a resin containing a colorant having an average particle diameter of 5 to 20 μm using a Henschel mixer or a Bert mixer to produce the toner. (2) A method of electrostatically adhering fine particles of a ferroelectric substance to a resin containing a colorant having an average particle diameter of 5 to 20 μm and embedding the fine particles in a toner binder with mechanical energy to produce the toner. Any of these may be used.

As for the amount of the ferroelectric substance added, in the case of internal addition,
10 to 70 parts by weight of a ferroelectric substance, 10 to 3 in the case of external addition
It is desirable to contain 0 part by weight. This is because if the addition amount is too small, the dielectric constant of the toner is not improved, and if the addition amount is too large, the color tone of the toner is lost. Furthermore, in order to achieve (ii) from the equation (1), the following method was used. That is, in order to thin the toner layer, the toner particle size used was 3.5 to 8 μm, which was smaller than that of the general-purpose toner (8 to 10 μm). Even if a toner having a particle diameter of 3.5 μm or less is used, the toner cannot be thinned by the layer thickness regulating member and the effect cannot be seen. The particle size distribution of the toner is 1.3 or less using the index of (volume average particle size / number average particle size). Even if the toner particle size is small, the particle size distribution is wide,
That is, when (volume average particle diameter / number average particle diameter) is larger than 1.5, the toner layer thickness on the developing roller becomes non-uniform and the development becomes unstable. Further, in order to efficiently obtain a toner having such a particle size and a particle size distribution and to improve the relative dielectric constant of the toner by internally adding a ferroelectric substance, (1)
The method of using the polymerized toner of (2) is preferable.

The non-magnetic insulating toner used herein has a toner resistance of 10 ⁸ Ωcm or more.

[0019]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention. First, the production of toner will be described. Toner A As a binder resin, a cross-linked polyester resin (NE2
150, Kao) and as a coloring material carbon book (Black Pearls L; average particle size 2.4 μm, specific surface area 138 m ² / g; Cabot) 5 parts by weight, dye (BY Orient Chemical) 1 part by weight 4 parts by weight of propylene wax (Viscole 550P, manufactured by Sanyo Kasei Co., Ltd.) were added and melt-kneaded at 160 ° C. for 30 minutes by a pressure kneader to obtain a toner mass. The cooled toner mass was made into a coarse toner of about ˜2 mm by a Rotoplex grinder. Next, the coarse toner is finely pulverized by using a jet mill (PJM pulverizer, manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and the pulverized product is classified by a wind force classifier (manufactured by Alpine Co., Ltd.) to obtain an average particle size of 10
A positively chargeable non-magnetic insulating toner A having a thickness of μm was obtained. Toner A
Had a dielectric constant ε of 3.1 and a (volume average particle diameter / number average particle diameter) of 1.2 (measured by a Coulter counter). Toners B to F The barium titanate (BT
-206, Fuji Titanium Industry Co., Ltd. was added, and Toners B to F were obtained in the same manner as Toner A. The physical properties of Toners B to F are shown in Table 1. Toners G to K In comparison with Toner A, barium titanate (BT-20
6, Toner A by changing the addition amount of Fuji Titanium Industry Co., Ltd.
To the toner G to be externally added using a Henschel mixer.
I got K. Table 2 shows the physical properties of Toners G to K. Toners L to Q Toners L to Q were obtained in the same manner as the toners B to F and G to K by changing the addition amount of the high dielectric substance to the material for the toner A. Table 3 shows the physical properties of the toners L to Q.
And 4 are shown. Toner R: Barium titanate (BT
-206, Fuji Titanium Industry Co., Ltd.) 30 parts by weight, iron powder 3
By adding 0 part by weight, a conductive toner R was obtained in the same manner as the toner A. Toner S Monomer Styrene (manufactured by Wako Pure Chemical Industries) 90 parts by weight Butyl acrylate (manufactured by Wako Pure Chemical Industries) 10 parts by weight n-Butyl methacrylate (manufactured by Wako Pure Chemical Industries) 5 parts by weight Colorant Carbon black (150T, manufactured by Degussa) 2 parts by weight Azochrome dye (S: 34, manufactured by Orient) 2 parts by weight Thermal polymerization initiator benzoyl peroxide 0.2 parts by weight Internal additive barium titanate (BT-206, Fuji Titanium Industry Co., Ltd.) 40 parts by weight The above monomer, colorant, initiator and wax were stirred for 3 minutes using a disperser (manufactured by Yamato Scientific Co., Ltd.) to prepare a monomer composition. Next, distilled water 500 containing 0.02% of polyvinyl alcohol (manufactured by Wako Pure Chemical Industries) as a dispersant.
The monomer composition was put in parts by weight and stirred at room temperature (20 ° C.) for 3 minutes using a disperser (4,000 rpm). After that, change the disperser to a three-one motor and heat to 80 ° C while stirring at 100 rpm.
The monomer composition was completely polymerized. Next, the produced toner dispersed in water was centrifuged and filtered. PH this toner
Washing with water is repeated until the value becomes 8 or less, and the volume average particle size is 10
A true spherical toner having a size of μm was obtained. Toner T Monomer Styrene (manufactured by Wako Pure Chemical Industries) 90 parts by weight Butyl acrylate (manufactured by Wako Pure Chemical Industries) 10 parts by weight n-Butyl methacrylate (manufactured by Wako Pure Chemical Industries) 5 parts by weight 2-hydroxy-3-methacryloxypropyl trimethyl ammonium chloride 5 Parts by weight Emulsifier Neogen SC (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 0.2 parts by weight Water-soluble thermal polymerization initiator N-50 (manufactured by Wako Pure Chemical Industries) 0.3 parts by weight Emulsion polymerization is carried out at 70 ° C. for 8 hours, Resin A was obtained. Resin A 100 parts by weight Colorant carbon black (150T, manufactured by Degussa) 3 parts by weight Azochrome dye (S: 34. Orient) 2 parts by weight Internal additive barium titanate (BT-206, Fuji Titanium Industry Co., Ltd.) ) 40 parts by weight The above mixture was dispersed and stirred with a slasher and held at 90 ° C for 6 hours. During this time, it was confirmed that the resin (A), the colorant, and the barium titanate complex (toner) grew to 10 to 12 μm, and the toner was centrifuged and filtered. This toner was repeatedly washed with water until the pH became 8 or less to obtain a toner T having a volume average particle diameter of 10 μm. Toner U 90 parts by weight of toner A and barium titanate (BT-20
6, Fuji Titanium Industry Co., Ltd. 40 parts by weight was applied with barium titanate on the toner surface by a Henschel mixer (FM-10B type, Mitsui Miike Engineering Co., Ltd.). After that, barium titanate was embedded on the toner surface by a high-speed air impact machine (Nara Machine). The embedding of barium titanate was confirmed by SEM photographs and fluorescent X-ray analysis. Toners V to Y Toners (8, 6, 4, 3.5 μm) having different volume average particle diameters were obtained by the same method as the toner A. Toners Z-1 and Z-2 In the same manner as Toner T, barium titanate was added internally, and the volume average particle diameter was 4 μm, and (volume average particle diameter / number average particle diameter) was 1.2 and 1.5. Toners Z-1 and Z-2 were obtained. Next, an image forming apparatus example 1 for carrying out the non-magnetic one-component developing method will be described.

In FIG. 2, the photosensitive drum 7 is provided with a transparent conductive layer 7B of an ITO (indium tin oxide) vapor deposition film on a glass transparent substrate 7C as shown in FIG. The photoconductor is made of amorphous silicon and α-Si (thickness is about 15 μm). The transparent conductive layer 7B of the photosensitive drum 7 as described above is connected to the ground, and the photosensitive drum 7 itself is conveyed in the direction of arrow A in the figure by a power system (not shown) for driving the drum.

The developing device comprises a conductive developing roller (developer holder) 14, a collecting roller 1, and a layer thickness regulating member 15 for forming a thin layer of the non-magnetic toner 3 on the developing roller 14. The non-magnetic toner 3 is filled in this developing device. The toner 3 is conveyed by the rotation of the conductive developing roller 14, but when the toner 3 is formed into a thin layer by the layer thickness regulating member (friction charging means) 15, the toner 3 is rubbed with the layer thickness regulating member 15 by 5 to 30.
μC / g is charged.

A positive charging type was used for the photosensitive drum 7 of this embodiment. Therefore, the developing roller 14 has the first power source 1
A positive voltage is applied by 7. This voltage is + 10V ~
+ 1000V is suitable. In addition, the collecting roller 1 has
A negative voltage is applied by the second power supply 18. This voltage is suitably 0V to -100V. An image exposure unit 8 is arranged at a position facing the developing device with the photoconductor drum 7 interposed therebetween. The image exposure means 8 is composed of an LED array that emits light according to an image signal and a SELFOC lens array that collects the image light of the LED array.

Next, the image recording procedure will be described. The photosensitive drum 7 is conveyed in the direction of arrow A, the developing roller 14 of the developing device is rotated to convey the toner 3 in the direction of arrow B, and a voltage is applied to the developing roller 14, while the image exposing means 8 is used. The photosensitive drum 7 is imagewise exposed. On the other hand, electron-hole pairs are generated in the photoconductive layer 7C, and the holes therein move to the surface of the photoconductive layer 7C by the electric field. The voltage applied to the developing roller 14 at this time is set to 10 to 1000 V (desirably 10 to 600 V). The toner 3 developed on the surface of the photosensitive drum 7 by the developing roller 14 moves to the collecting roller 1. A voltage having a polarity opposite to that of the developing roller 14 is applied to the collecting roller 1, and the toner 3 attached to the non-exposed portion is collected by this voltage. At this time, most of the toner 3 in the exposed portion remains on the photoconductor 7 due to electrostatic attraction with the latent image charge on the surface of the photoconductive layer 7C, so that a toner image is formed.

Next, the toner image is electrostatically transferred onto the recording paper 12 using the transfer roller 13. The transferred toner image is fixed on the recording paper 12 by a fixing device, and a semi-permanent recorded image is obtained. According to the present embodiment, no corona discharger that generates ozone harmful to the human body and requires a high voltage of several kV is used. Moreover, since the number of steps is smaller than that of the Carlson process and the recording process is simple, the apparatus can be downsized.

Reference numeral 2 is a collecting blade, 9 is a discharging lamp, 11 is a heat roller, and 16 is a reset roller. Example 1 Using Device Example 1, toners A to F were used to measure the minimum latent image bias. When toners C to F having the lowest latent image bias of 600 V or less were used, good printing was obtained without leakage in the apparatus.

4 and 5 show the relationship between the amount of barium titanate added and the toner dielectric constant, and the relationship between the toner dielectric constant and the minimum latent image bias.

[0027]

[Table 1]

Example 2 Using Device Example 1, toners G to K were used to measure the lowest latent image bias. If toners H to K whose minimum latent image bias is 600 V or less are used, there is no leak in the apparatus. However, with toners J and K, the color tone of the toner became light and good printing could not be obtained. For toners H and I, good printing was obtained.

[0029]

[Table 2]

Example 3 Using Device Example 1, toners L to Q were used to measure the lowest latent image bias. Good printing was obtained with both internal and external additions.

[0031]

[Table 3]

[0032]

[Table 4]

Comparative Example 1 Using Device Example 1, the transferability of toners D and R to plain paper was compared. With the low resistance toner R, the transfer becomes insufficient,
The image density (OD) was 0.8 at the maximum, and printing was defective.

[0034]

[Table 5]

Example 4 Using Example 1 of the apparatus, toners S to U were used to measure the lowest latent image bias. Good printing was obtained with these toners.

[0036]

[Table 6]

Example 5 Using Device Example 1, toners A and V to Y were used to measure the lowest latent image bias. Good printing was obtained with toners V to Y.

[0038]

[Table 7]

Example 6 Using Device Example 1, the lowest latent image bias was measured using toners Z-1 and Z-2. With toner Z-1, good printing was obtained, but with toner Z-2, a leak sometimes occurred from the developing roller, and the photoreceptor was rapidly deteriorated.

[0040]

[Table 8]

[0041]

As described above, according to the present invention, in an image forming system in which image exposure is performed from the back surface of the photoconductor and development is performed at the same time, the ferroelectric substance is internally or externally added to the toner. Therefore, there is no density unevenness, and a good image can be stably formed.

[Brief description of drawings]

FIG. 1 is a diagram showing a developing unit.

FIG. 2 is a diagram showing an example of an image forming apparatus.

FIG. 3 is a partial cross-sectional view of a photoconductor

FIG. 4 is a graph showing the relationship between the amount of barium titanate added and the toner dielectric constant.

FIG. 5 is a graph showing the relationship between toner permittivity and minimum latent image bias.

FIG. 6 is a diagram showing an example of a conventional image forming apparatus.

FIG. 7 is an explanatory diagram of an image forming principle.

[Explanation of Codes] 1: Recovery Roller 2: Recovery Blade 3: Toner 7: Photosensitive Drum (Photosensitive Member) 7A: Transparent Substrate 7B: Transparent Conductive Layer 7C: Photoconductive Layer 8: Image Exposure Means 9: Elimination Lamp 11: Heat roller 12: Recording paper 13: Transfer roller 14: Developing roller 15: Layer thickness regulating member (friction charging means) 16: Reset roller 17: First power supply 18: Second power supply

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location 381 384 (72) Inventor Ken Ogino 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited

Claims (11)

[Claims] 1. A photoconductor comprising a transparent substrate, a transparent or semitransparent conductive layer and a photoconductive layer, and a photoconductor layer disposed on the photoconductor side of the photoconductor, and a developer is developed on the photoconductor. And a recovery means for recovering the developer other than the image portion on the photoconductor, a conductive layer side of the photoconductor, and a position facing the development means. An image forming apparatus including an image exposing unit that performs exposure is used, and a photosensitive member rotating at a constant speed is contacted on the outer periphery of a developer holder that rotates in pressure contact with the upstream side of a frictional charging member. Used in a developing method in which toner is supplied, the toner is charged by friction charging means, and the toner is conveyed to a pressure contact portion with a photoconductor by a developer holder, and is developed on the photoconductor. 10 to
An electrophotographic toner characterized by being internally added in an amount of 70 parts by weight. 2. The ferroelectric substance is barium titanate, strontium titanate, lead titanate, lithium titanate,
Characterized by comprising fine powders of potassium titanate, bismuth titanate, calcium titanate, titanium oxide, alumina, lithium niobate, potassium niobate, sodium niobate, lead zirconate, beryllium zirconate and solid solutions thereof. The electrophotographic toner according to claim 1. 3. The toner for electrophotography according to claim 1, wherein the toner containing the ferroelectric substance has a dielectric constant of 4.5 or more. 4. An electrophotographic process, wherein a colorant and a ferroelectric substance are dispersed in a radical-polymerizable vinyl monomer and then suspension polymerization is carried out to produce a toner containing the ferroelectric substance internally. For manufacturing toner for toner. 5. A colorant is dispersed in a radically polymerizable vinyl-based monomer and then emulsion-polymerized to disperse a ferroelectric substance in the emulsion-polymerized substance, which is built up together with the ferroelectric substance. A method for producing a toner for electrophotography, which comprises producing a toner containing a ferroelectric substance internally. 6. A toner for electrophotography, comprising a thermoplastic resin as a binder resin, kneading, pulverizing and classifying a resin, a colorant and a ferroelectric substance to produce a toner containing a ferroelectric substance internally. Manufacturing method. 7. A photoconductor comprising a transparent substrate, a transparent or semi-transparent conductive layer and a photoconductive layer, and a photoconductor layer disposed on the photoconductive layer side of the photoconductor to develop a developer on the photoconductor. And a recovery means for recovering the developer other than the image portion on the photoconductor, a conductive layer side of the photoconductor, and a position facing the development means. An image forming apparatus including an image exposing unit that performs exposure is used, and a photosensitive member rotating at a constant speed is contacted on the outer periphery of a developer holder that rotates in pressure contact with the upstream side of a frictional charging member. Used in a developing method in which toner is supplied, the toner is charged by friction charging means, and the toner is conveyed to a pressure contact portion with a photoconductor by a developer holder, and is developed on the photoconductor. 10 to
An electrophotographic toner comprising 30 parts by weight of external addition. 8. A toner in which a ferroelectric substance is electrostatically adhered to a colorant-containing resin having an average particle diameter of 5 to 20 μm and is fused to the contained resin by mechanical energy to produce a toner externally added with the ferroelectric substance. A method for producing an electrophotographic toner, comprising: 9. A method of producing a toner for electrophotography, which comprises electrostatically adhering a ferroelectric substance to a resin containing a colorant having an average particle size of 5 to 20 μm to produce a toner to which the ferroelectric substance is externally added. Method. 10. The toner for electrophotography according to claim 1, wherein the toner is a non-magnetic insulating toner. 11. The toner according to claim 1, wherein the toner has a volume average particle diameter of 3.5 to 8 μm and a volume average particle diameter / number average particle diameter of 1.3 or less. Item 1. An electrophotographic toner according to items 1 to 10.