JP3243597B2 - Image forming method, image forming apparatus, and toner kit - Google Patents

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 using an intermediate transfer member in an electrophotographic method or an electrostatic recording method, an image forming apparatus, and a toner kit used therefor. More specifically, the present invention provides a method for forming a toner image on an electrostatic latent image carrier, transferring the toner image from the electrostatic latent image carrier onto an intermediate transfer member, and further transferring the toner image from the intermediate transfer member onto a transfer material. The present invention relates to an image forming method, an image forming apparatus, and a toner kit used for a copier, a printer, a facsimile, and the like, which form an image by transferring the image onto the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, many electrophotographic methods are known. In general, a photoconductive substance is used to form an electrostatic latent image on a photoreceptor by various means, and then the electrostatic latent image is developed with toner to form a toner image. After transferring the toner image to a transfer material such as
The toner image is fixed on the transfer material by pressure or the like to obtain a copy or print.

Conventionally, in a full-color copying machine, an electrostatic latent image formed on each photoconductor using four photoconductors is developed using a cyan toner, a magenta toner, a cyan toner or a black toner to form a belt-like image. The transfer material is transported by the transfer body,
After transferring each color toner image to the transfer material, a method of forming a full-color image or winding the transfer material by a mechanical action such as an electrostatic force or a gripper on the surface of the transfer material holding member facing one photoconductor, and developing-transferring A method of obtaining a full-color image by performing the process four times is generally used.

In recent years, in addition to ordinary paper and overhead projector films (OHP) as full-color transfer materials, there is an increasing need to support small-size paper such as cardboard, cards, and postcards. In the above method using four photoconductors, the transfer material is conveyed in a flat plate shape, so that the range of application to various transfer materials is wide, but a plurality of toner images are accurately overlapped at predetermined positions on the transfer material. It is necessary, and even a small difference in registration deteriorates the image quality. In order to enhance the accuracy of registration, there is a problem that the transfer material transport mechanism is complicated and the number of components is increased. On the other hand, in the method of adsorbing and winding the transfer material on the surface of the transfer material holding member, when using a thick weighed paper, the rear end of the transfer material causes poor adhesion due to the strength of the transfer material, resulting in poor transfer. Image defects are likely to occur. Similarly, image defects are likely to occur on small-size paper.

On the other hand, an image forming method using an intermediate transfer member has also been proposed.

For example, a full-color image apparatus using a drum-shaped intermediate transfer member is disclosed in US Pat. No. 5,187,526.
In the specification. However, U.S. Pat. No. 5,187,526 does not specifically describe the shape and composition of toner particles.

Further, Japanese Patent Application Laid-Open No. 59-15739 discloses that a toner image formed with a toner having an average particle diameter of 10 μm or less is transferred to an intermediate transfer member, and the toner image on the intermediate transfer member is further transferred to a transfer member. This paper describes a recording method, and further describes a method of directly producing toner particles using a suspension polymerization method as one of the methods for producing a toner.

However, the transfer process described in JP-A-59-15739 is a transfer using a pressure transfer or an adhesive transfer. This is completely different from a transfer step of transferring a toner image mainly by using an electric attraction in the inside.

Further, Japanese Patent Application Laid-Open No. 59-50473 discloses that a toner image on an image carrier is formed on a surface of a support heated to a predetermined temperature by using a heat-resistant elastic layer and an addition polymerization type silicone rubber. An electrostatic recording method or an electrophotographic copying method in which a toner image is transferred to an intermediate transfer member having a layer and a toner image on the intermediate transfer member is further transferred to a transfer material.

However, in the image forming method described in JP-A-59-50473, the image carrier in contact with the heated intermediate transfer member is apt to deteriorate. There is no description about a transfer step using an intermediate transfer member to which a voltage is applied. In a system using an intermediate transfer member, it is necessary to transfer the toner image from an electrostatic image holding member such as a photoreceptor to the intermediate transfer member, and then transfer the toner image from the intermediate transfer member onto a transfer material again. It is necessary to increase the transfer efficiency of the conventional method.

Since the transfer efficiency of the toner image from the intermediate transfer member to the transfer material is low, a cleaning member is indispensable for the intermediate transfer member.
Improvement in transfer efficiency has been demanded.

Further, Japanese Patent Application Laid-Open No. 61-279864 proposes a toner in which the shape factors SF-1 and SF-2 are specified. However, as a result of additional tests of the toner of the example of this publication, the transfer efficiency was low, and particularly when used in an image forming apparatus using an intermediate transfer member, the transfer efficiency was insufficient, and further improvement was required. Was.

Japanese Unexamined Patent Publication (Kokai) No. 63-235953 proposes a magnetic toner which is made spherical by mechanical impact. However, the transfer efficiency when used in an image forming apparatus using an intermediate transfer body is still insufficient, and further improvement is required.

In recent years, from the viewpoint of environmental protection, a primary charging and transfer process using a photosensitive member contact member which generates almost no ozone from a conventional primary charging and transfer process using corona discharge has been mainly used. It is becoming.

Specifically, a voltage is applied to a medium-resistance roller or a medium-resistance brush, which is a charging member, and the roller or brush is brought into contact with a photoconductor, which is a member to be charged, to charge the surface of the photoconductor to a predetermined potential. It is to let. For example,
In JP-A-13661, it is possible to apply a low voltage when charging the photosensitive member by using a roller in which a core made of a dielectric material made of nylon or polyurethane rubber is used. JP-A-63-149669 and JP-A-2-123385 propose a contact charging method and a contact transfer method. A conductive elastic roller is brought into contact with the electrostatic latent image carrier, and the electrostatic latent image carrier is uniformly charged while applying a voltage to the conductive roller,
Next, an electrostatic latent image is formed by exposure, and after a toner image is obtained by a developing process, a transfer material is passed while pressing another conductive roller to which a voltage has been applied to the electrostatic latent image carrier. After transferring the toner image on the electrostatic latent image carrier to a transfer material, a copy image is obtained through a fixing process.

However, in such a contact transfer method that does not use corona discharge, the transfer member is brought into contact with the photosensitive member via the transfer member at the time of transfer, so that the toner image formed on the photosensitive member is transferred to the transfer material. When the toner image is transferred to the toner image, the toner image is pressed against the toner image, and a problem of partial transfer failure called so-called missing transfer is likely to occur as shown in FIG.

In the case of using a full-color copying machine or a full-color printer for transferring a plurality of toner images after development, the amount of toner on the intermediate transfer member increases as compared with the case of a single-color black toner using a black-and-white copying machine. It is difficult to improve the transfer efficiency when using a conventional irregular toner having large SF1, SF-1 and SF-2. Further, when a general amorphous toner is used, the slip force and the rubbing force between the photosensitive member and the cleaning member, between the intermediate transfer member and the cleaning member, and / or between the photosensitive member and the intermediate transfer member are reduced. Therefore, toner fusion and filming easily occur on the surface of the photoreceptor or the surface of the intermediate transfer member. Further, the transfer efficiency is apt to deteriorate, and it is difficult to transfer the four color toner images uniformly in the generation of a full-color image.
Problems tend to occur in terms of color unevenness and color balance, and it is not easy to stably output a high-quality full-color image.

[0018]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method using an intermediate transfer member which solves the above-mentioned problems of the prior art.

An object of the present invention is to provide an image forming method and an image forming apparatus which are excellent in toner image transfer efficiency.

An object of the present invention is to provide an image forming method and an image forming apparatus which can transfer to a small-size transfer material such as a cardboard or a card and a postcard.

An object of the present invention is to provide an image forming method and an image forming apparatus in which the occurrence of toner fusion and filming on the surface of the electrostatic latent image holding member and the surface of the intermediate transfer member are suppressed.

An object of the present invention is to provide an image forming method and an image forming apparatus which are excellent in forming a multi-color image or a full-color image.

An object of the present invention is to provide a toner kit suitable for the above-described full-color image forming method.

An object of the present invention is to provide a toner kit having a high image density, excellent thin line reproducibility, and excellent highlight gradation.

An object of the present invention is to provide a toner kit having excellent transferability without scattering during transfer.

An object of the present invention is to provide a toner kit which does not change its performance over a long period of use.

[0027]

According to the present invention, there is provided a developing step of developing an electrostatic latent image with a developer to form a toner image on an electrostatic latent image carrier, and applying a voltage to the toner image. At least a secondary transfer step of transferring the toner image on the intermediate transfer body onto the transfer material while pressing a transfer means to which a voltage is applied against the transfer material; An image forming method, wherein the developer has a toner, and the toner is a black toner having at least a black toner particle in which a colorant is dispersed in a binder resin and inorganic fine powder. The value of the shape factor SF-1 is 11
0 <SF-1 ≦ 180, and the value of the shape factor SF-2 is 110 <SF-2 ≦ 140.
The present invention relates to an image forming method, wherein a ratio B / A of a value B obtained by subtracting 00 from a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

Further, the present invention provides an electrostatic latent image carrier, a developing means having a developer for forming a toner image on the electrostatic latent image carrier, and a toner image transferred from the electrostatic latent image carrier. For transferring the toner image on the intermediate transfer member to a transfer material, the transfer member being provided so as to press the intermediate transfer member having the bias application portion for transferring the toner image on the intermediate transfer member to a transfer material. An image forming apparatus having at least a means, wherein the developer has a toner, the toner is a black toner having black toner particles and inorganic fine powder in which a colorant is dispersed in at least a binder resin, The black toner of the present invention includes a developing step of forming a toner image on an electrostatic latent image carrier, a primary transfer step of transferring the toner image onto an intermediate transfer body to which a voltage is applied, and a step of applying a voltage. Transfer member An image forming method using an electrophotographic apparatus having a secondary transfer step of transferring a toner image on the intermediate transfer member onto the transfer material while contacting the material, wherein the toner has a colorant in at least a binder resin. The toner has dispersed toner particles and inorganic fine powder, and the toner has a shape factor SF-1 value of 11 measured by an image analyzer.
0 <SF-1 ≦ 180, and the value of the shape factor SF-2 is 110 <SF-2 ≦ 140.
The present invention relates to an image forming apparatus, wherein a ratio B / A of a value B obtained by subtracting 00 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

The present invention further provides a yellow toner having at least a yellow colorant and a binder resin and a yellow toner having an inorganic fine powder, and a magenta toner having at least a magenta colorant and a binder resin. A magenta toner having particles and inorganic fine powder, a cyan toner having at least a cyan colorant and a binder resin, a cyan toner having inorganic fine powder, and at least carbon black or / and a magnetic material and a binder resin A black toner particle and a black toner having an inorganic fine powder, the black toner has a shape factor SF-2 of 140 or less and a shape factor S of yellow toner, magenta toner and cyan toner.
F-2, which is larger than F-2.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the shape factor SF-
1 and the shape factor SF-2 are, for example, FE manufactured by Hitachi, Ltd.
-Using a SEM (S-800), 100 toner images of 2 μm or more that were enlarged 1000 times were randomly sampled, and the image information was sent to an image analyzer (Luzex III) manufactured by Nicolet, for example, via an interface. Introduced and analyzed, the value calculated from the following equation is used to calculate the shape factor SF
-1 and shape factor SF-2.

[0031]

(Equation 1)

(Where MXLNG is the absolute maximum length of the particle,
PERIME indicates the perimeter of the particle, and AREA indicates the projected area of the particle. )

The shape factor SF-1 indicates the degree of roundness of the toner particles, and the shape coefficient SF-2 indicates the degree of irregularities on the surface of the toner particles.

If the shape factor SF-1 of the black toner exceeds 180 or SF-2 exceeds 140, the toner is separated from a spherical shape and approaches an irregular shape, the toner is easily crushed in the developing device, and the particle size distribution varies. And the charge amount distribution tends to be broad, and ground fogging and reverse fogging tend to occur. The transfer efficiency of the toner image at the time of transfer from the electrostatic image holding member to the intermediate transfer member is reduced, and the transfer efficiency of the toner image at the time of transfer from the intermediate transfer member to the transfer material is reduced, and the transfer of the line image occurs during transfer. Not preferred. SF-1 of black toner is 1
10 or less, or the spherical coefficient SF-2 of the toner is 11
In the case of 0 or less, or when the value of the ratio B / A exceeds 1.0, cleaning failure generally tends to occur. The present invention has solved the above-mentioned problem by at least satisfying the condition defined by the present invention in the shape of the black toner.

More preferably, the value of SF-1 is 120 ≦
SF-1 ≦ 160, and the value of SF-2 is 115 ≦
SF-2 ≦ 140. A toner particle produced by a pulverization method and subjected to a curved surface treatment is preferably used.

In a full-color toner kit having a cyan toner, a yellow toner, a magenta toner, and a black toner, it is preferable that SF-2 of the black toner is maximized.

For the purpose of improving the transferability, it has been conventionally attempted to recharge or eliminate the toner image on the electrostatic latent image carrier so as to optimize the toner image. However, scattering on the transfer material has been attempted. Was not always satisfactory. This tendency is particularly noticeable in a black toner, and it is necessary to achieve both good toner development and good transferability.

After repeated studies on the toner shape,
By making the shape of the black toner non-spherical than other colors, the development or transfer electric field effectively acts on the convex portion, and furthermore, due to its moderate surface resistance, the electric field acts uniformly on the toner particles, We have found that high image quality can be achieved.

Protrusions appropriately present on the surface of the toner particles function effectively as an electrode effect, and transfer properties without scattering can be obtained.

It is preferable that SF-2 of the black toner is larger than SF-2 of the cyan toner, SF-2 of the yellow toner and SF-2 of the magenta toner by 5 or more.

Further, the cyan toner, yellow toner and magenta toner have SF-1 of 100 to 170 (more preferably 100 to 160, more preferably 100 to 150) and SF-2 of 100 to 139 (more preferably 100 to 139). To 130, more preferably 100
To 125) are good.

In the black toner, SF-2 to 100
The value of the ratio B / A of the value B obtained by subtracting the equation (1) and the value A obtained by subtracting 100 from SF-1 indicates the slope of a straight line passing through the origin in FIG. The ratio B / A is preferably 0.20 to 0.90 (further preferably 0.35 to 0.85) in order to improve transferability while maintaining good developability.

Further, by having the inorganic fine powder on the surface of the toner particles, the transfer efficiency can be improved and the omission during transfer of a character or a line image can be improved. At this time, the specific surface area Sb per unit volume measured by the BET method and the specific surface area St per unit volume calculated from the weight average particle diameter (D ₄ ) assuming that the toner is a true sphere (St = 6 / D ₄ ) is 3.0 ≦ Sb / St ≦ 7.0 and Sb ≧ St × 1.5
It is preferably +1.5. Furthermore, Sb is 3.2 to
6.8 m ² / cm ³ (more preferably 3.4 to 6.3 m ²
/ Cm ³ ).

When the above ratio is less than 3.0 times, the transfer efficiency decreases, and when it exceeds 7.0 times, the image density decreases. This is considered to be due to the fact that the inorganic fine particles added to the toner particles effectively act as a spacer between the toner particles and the toner image carrier.

The specific surface area of the toner in the above range can be achieved by controlling the specific surface area of the toner particles and the specific surface area, the amount and the mixing strength of the inorganic fine powder added to the toner particles. If the mixing strength of the addition is too high, the inorganic fine particles are embedded in the toner particles, and the transfer efficiency is hardly improved.

Furthermore, since the inorganic fine powder is used effectively, the specific surface area Sr per volume of the toner particles is 1.2 to
2.5m ² / cm ³ (preferably 1.4~2.1m ² / c
m ³ ), which is 1.5 to 1.5 of the theoretical specific surface area per volume calculated from the weight average particle diameter when the toner is assumed to be a true sphere.
It is better to be 2.5 times.

The specific surface area is preferably increased by 1.5 m ² / cm ³ or more by adding the inorganic fine powder. The 60% pore radius in the cumulative pore area ratio curve of the pores of 1 nm to 100 nm of the toner particles before adding the inorganic particles is preferably 3.5 nm or less. At this time, the toner B
The ratio Sb / Sr of the ET specific surface area Sb to the BET specific surface area Sr of the toner particles is preferably in the range of 2 to 5.

[0048] These are those which reduce the number of pores in the toner particles which are equal to or larger than the primary particle diameter of the inorganic fine powder added to the toner particles, whereby the inorganic fine powder behaves more effectively and improves the transfer efficiency. it is conceivable that.

The specific surface area is determined by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) according to the BET method, and calculating the specific surface area using the BET multipoint method. The 60% pore radius is determined from a cumulative pore area ratio curve to the pore radius on the desorption side. In Autosorb 1, the calculation of the pore distribution is performed by Barrett.
t, Joyner & Harenda (BJ.
H). J. Perform by the H method.

In the present invention, since an intermediate transfer member is provided to cope with various types of transfer materials, the transfer step is performed substantially twice, so that a decrease in transfer efficiency causes a decrease in toner use efficiency. Become. In a digital full-color copier or printer, a color image original is subjected to color separation using a B (blue) filter, a G (green) filter, and an R (red) filter in advance, and then 20 to 70 .mu.m on a photoreceptor.
m (dot) latent image is formed, Y (yellow) toner, M (magenta) toner, C (cyan) toner, B (black)
It is necessary to reproduce a multicolor image faithful to a document by utilizing the subtractive color mixing action using each color toner. At this time, since the Y toner, the M toner, the C toner, and the B toner are multiplexed on the photoreceptor or the intermediate body in accordance with the color information of the original or the CRT, the toner used in the present invention is extremely low. High transferability is required.

The black toner is preferably a magnetic toner.
A non-magnetic toner is preferably used for a color toner of another color in order to obtain a vivid color.

To faithfully develop minute latent image dots for higher image quality, the toner particles have a weight average diameter of 4 μm.
It is preferably about 9 μm. Weight average diameter of 4 to 9
In the case of toner particles having a diameter of μm, the transfer efficiency is less reduced, the amount of toner remaining after transfer on the photosensitive member or the intermediate transfer member is small, and non-uniform unevenness of an image due to fogging or poor transfer is less likely to occur. Further, the weight average diameter of the toner particles is 4 to 9
In the case of μm, scattering of characters and line images hardly occurs.

The average particle size and particle size distribution of the toner are measured using a measuring machine such as Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter), and an interface (manufactured by Nikkaki) for outputting the number distribution and volume distribution.
And PC9801 personal computer (NEC)
And the electrolyte is 1-grade sodium chloride.
% NaCl aqueous solution is prepared. For example, ISOTON
R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, a surfactant (preferably an alkylbenzene sulfonate) is used as a dispersant in 100 to 150 ml of the aqueous electrolyte solution in an amount of 0.1 to 5 ml.
ml, and 2 to 20 mg of the measurement sample. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, using a 100 μm aperture as an aperture by the Coulter Counter TA-II,
The volume distribution and the number distribution are calculated by measuring the volume and the number of toner particles having a size of 2 μm or more. Then, a volume-based weight average particle diameter (D ₄ ) obtained from the volume distribution according to the present invention and a number-based length average particle diameter (D ₁ ) obtained from the number distribution are obtained.

The charge amount per unit volume (two-component method) of the toner according to the present invention is preferably ^{30 to} 80 C / m ³ (more preferably 40 to 70 C / m ³ ). It is preferable to improve the transfer efficiency in the transfer method used.

The method for measuring the charge amount (two-component tribo) of the toner according to the two-component method in the present invention will be described below with reference to FIG.

Under an environment of 23 ° C. and 60% relative humidity, iron powder EFV200 / 300 (manufactured by Powder Tech) was used as a carrier, and a mixture obtained by adding 0.5 g of toner to 9.5 g of carrier was prepared by mixing 50 to 100 ml of polyethylene. And shake by hand 50 times. Then, 1.0 to 1.2 g of the mixture is placed in a metal measuring container 22 having a 500-mesh screen 23 at the bottom, and a metal lid 24 is placed. At this time, the weight of the entire measuring container 22 is weighed and W ₁ (g)
And Next, in the suction machine (at least the portion in contact with the measurement container 22 is an insulator), the pressure of the vacuum gauge 25 is adjusted to 2450 Pa by suctioning from the suction port 27 and adjusting the air volume control valve 26.
(250 mmAq). In this state, suction is performed for one minute to remove the toner by suction. The potential of the electrometer 29 at this time is set to V (volt). Reference numeral 28 denotes a capacitor having a capacity of C (μF). The weight of the entire measuring machine after suction is weighed and is defined as W ₂ (g). The triboelectric charge amount of this toner (mC / k
g) is calculated as follows:

Triboelectric charge (mC / kg) = CV / (W ₁ −W ₂ )

Further, by multiplying the triboelectric charge by the true density, the triboelectric charge per unit volume (C / m ³ ) can be obtained.

The true density of the toner is measured by a gas displacement type densitometer Acc.
It is measured using upyc1330 (manufactured by Micromeritics).

As the binder resin in the toner, the peak of low molecular weight in the molecular weight distribution of gel permeation chromatography (GPC) is in the range of 3,000 to 15,000, and the shape of the toner produced by the pulverization method is determined by heat and mechanical properties. It is preferable in controlling with a mechanical impact force. When the peak of the low molecular weight exceeds 15,000, it is difficult to control the shape factors SF-1 and SF-2 within the range of the present invention, and the transfer efficiency is not sufficiently improved. When the molecular weight is less than 3,000, fusion tends to occur during the surface treatment of the toner particles. The molecular weight is GP
Measured by C. As a specific GPC measurement method, a sample obtained by previously extracting a toner with tetrahydrofuran (THF) using a Soxhlet extractor for 20 hours was used, and the column configuration was A-801, 802, 8 manufactured by Showa Denko.
03, 804, 805, 806 and 807 can be linked and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve.

A resin having a ratio (Mw / Mn) of 2 to 100 between the weight average molecular weight (Mw) and the number average molecular weight (Mn) is preferable in the present invention.

The glass transition point (Tg) of the toner is
50 ° C. to 75 ° C. (more preferably 5 ° C. to 5 ° C.)
2 ° C to 70 ° C) is preferred.

The glass transition point of the toner is measured by, for example, a high-precision internal heating type input compensation type differential scanning calorimeter such as DSC-7 manufactured by Perkin Elmer. The measuring method is performed according to ASTM D3418-82.
In the present invention, the material is heated once to obtain a pre-history, then rapidly cooled, and again at a temperature rate of 10 ° C / min and a temperature of 0 to 2 ° C.
A DSC curve measured when the temperature is raised in the range of 00 ° C. is used.

The binder resin used in the present invention is a polystyrene; a styrene-substituted homopolymer such as poly-p-chlorostyrene and polyvinyltoluene; a styrene-p-chlorostyrene copolymer and a styrene-vinyltoluene copolymer. Polymer, styrene-vinylnaphthalene copolymer, styrene-
Acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer Styrene copolymers such as polymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers; polyvinyl chloride, phenolic resins, natural Modified phenolic resin, natural resin modified maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene Fat, coumarone-indene resin, petroleum resin, or the like can be used. Crosslinked styrenic resins are also preferred binder resins.

As comonomers for the styrene monomer of the styrene copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, Monocarboxylic acids having a double bond, such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, and acrylamide; or substituted products thereof; maleic acid, butyl maleate, and maleic acid Dicarboxylic acids having a double bond such as methyl acrylate and dimethyl maleate and their substituted products; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; and ethylene such as ethylene, propylene and butylene System olefins; vinyl methyl ketone, vinyl ketones such as vinyl hexyl ketone;
Vinyl monomers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; and the like. These are used alone or in combination. As the crosslinking agent, a compound having two or more polymerizable double bonds is used. For example,
Aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate;
Carboxylic acid esters having two double bonds such as ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinylether, divinylsulfide and divinylsulfone; A compound having;
Is mentioned. These may be used alone or as a mixture.

From the viewpoint of improving the releasability from the fixing member at the time of fixing and improving the fixing property, it is also preferable to include the following waxes in the toner particles. Paraffin wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, polyolefin wax and its derivatives, carnauba wax and its derivatives. Derivatives include oxides,
Examples include a block copolymer with a vinyl monomer and a graft modified product.

In addition, long-chain alcohols, long-chain fatty acids, acid amides, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, mineral waxes, petrolactam, etc. may be used in some cases. good.

In order to prepare a black toner, a binder resin, wax, a pigment as a colorant, a dye, or a magnetic substance, and if necessary, an additive such as a charge control agent are mixed with a mixer such as a Henschel mixer or a ball mill. After sufficient mixing, the pigment, dye or magnetic material is dispersed or dissolved in the resin by melting and kneading using a hot kneader such as a heating roll, kneader, extruder, and then solidified by cooling, followed by pulverization and classification. To obtain a black toner. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

As the surface treatment of the black toner particles, the toner particles obtained by the pulverizing method are treated by dispersing in water and heating in a hot water bath, a heat treatment method in which the toner particles are passed through a hot air flow, and applying mechanical energy. Mechanical impact method and the like can be mentioned.
In the present invention, a thermomechanical impact method in which the toner particles are treated at a temperature (Tg ± 10 ° C.) near the glass transition point Tg of the toner particles in the mechanical impact method is preferable from the viewpoint of preventing aggregation and productivity. More preferably, it is performed at a temperature in the range of the glass transition point Tg ± 5 ° C. of the black toner, by reducing pores having a radius of 10 nm or more on the surface of the toner particles, effectively using the inorganic fine powder on the toner particles, This is particularly effective for improving the transfer efficiency of the image.

The toner can be obtained by atomizing the molten mixture into air using a disk or a multi-fluid nozzle as described in JP-B-56-13945, etc. to obtain a spherical toner.
No. 10231, JP-A-59-53856 and JP-A-59-61842, in which a toner is directly produced by using a suspension polymerization method, or a method in which a toner is soluble in a monomer. Using an emulsion polymerization method typified by a dispersion polymerization method of directly producing a toner using an insoluble aqueous organic solvent or a soap-free polymerization method of producing a toner by directly polymerizing in the presence of a water-soluble polar polymerization initiator. Toner particles may be manufactured.

In particular, the production of toner particles by a suspension polymerization method is preferred. Further, toner particles obtained by a seed polymerization method in which a monomer is further adsorbed onto the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

It is also preferable to add a polar resin such as a styrene- (meth) acrylic acid copolymer, a styrene-maleic acid copolymer, or a saturated polyester resin to the toner particles.

Further, when toner particles having a charge control agent are produced by a direct polymerization method in the present invention, it is preferable to use a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous medium. .

When the direct polymerization method is used for the production of toner particles, the toner particles can be produced by the following method. Add a releasing agent consisting of a low softening substance, a colorant, a charge control agent, a polymerization initiator, and other additives to the polymerizable monomer, and uniformly dissolve or disperse them with a disperser such as a homogenizer or an ultrasonic disperser. The resulting polymerizable monomer composition is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer, homomixer, or homogenizer. Preferably, the agitation speed and time are adjusted so that the droplets of the polymerizable monomer composition have the desired size of the toner particles, and the granulation is performed. After that, by the action of dispersion stabilizer,
The stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C.

Further, preferred embodiments of the yellow toner, magenta toner and cyan toner will be described.

The effect of the present invention can be enhanced by using a toner in which part or all of the toner particles are formed by a polymerization method. In particular, for toner particles in which a portion of the toner particle surface is formed by a polymerization method, pre-toner (monomer composition) particles are present in a dispersion medium and a necessary portion is generated by a polymerization reaction. A considerably smoothed version can be obtained.

Further, by providing the toner particles with a core / shell structure and using the toner particles formed by polymerization of the shell portion, the toner particles preferably used in the image forming method of the present invention can be produced. Needless to say, the core / shell structure improves the blocking resistance without impairing the excellent fixability of the toner, and it is better to polymerize only the shell portion compared to a bulk polymerized toner having no core. In the post-treatment step after the polymerization step, the removal of the residual monomer can be easily performed.

As the main component of the core portion, a substance having a low softening point is preferable, and the main maximum peak value of the endothermic peak measured according to ASTM D3418-8 is 40 to 90 ° C.
Are preferred. When the maximum peak is less than 40 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high-temperature offset resistance decreases. On the other hand, the maximum peak is 9
If the temperature exceeds 0 ° C., the fixing temperature increases.

For measurement of the temperature of the maximum peak value of the low softening point substance, for example, DSC-7 manufactured by Perkin Elemer Co., Ltd. is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of the calorific value uses the indium heat of fusion. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C / min. Perform the measurement with.

Examples of the low softening point substance include paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax, derivatives thereof, and graft / block compounds thereof.

The low softening point substance is added to the binder resin 1 in the toner particles.
It is preferable to add 5 to 30 parts by weight per 00 parts by weight. When the addition is less than 5 parts by weight, the above-mentioned removal of the residual monomer is burdensome. When the addition exceeds 30 parts by weight,
Also in the production by the polymerization method, coalescence of toner particles tends to occur during granulation, and a toner having a wide particle size distribution is easily generated.

Further, by coating the surface of the toner with an external additive such as inorganic fine powder, the coverage of the external additive on the surface of the toner particles is 5 to 99%, more preferably 10 to 9%.
It is preferably 9%. The external additive coverage on the toner particle surface is determined by randomly sampling 100 toner particle images (for example, 20,000 times) using FE-SEM (S-800) manufactured by Hitachi, Ltd., and the image information is transmitted via an interface. Then, an image analysis device (Luzex3) manufactured by Nicole is introduced, analyzed, and calculated.

As the external additive, from the viewpoint of durability when mixed with the toner particles, 1/10 of the weight average diameter of the toner particles is used.
The particle diameter is preferably as follows. The particle size of the additive means toner particles (for example, 20,000 times) in an electron microscope.
Means the average particle size obtained by observation of the surface. External additives include metal oxide fine powder (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.), nitride fine powder (silicon nitride, etc.), carbide Fine powder (silicon carbide, etc.), metal salt fine powder (calcium sulfate,
Barium sulfate, calcium carbonate and the like), fatty acid metal salt fine powder (zinc stearate, calcium stearate and the like), carbon black and silica fine powder.

These external additives are used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the toner particles. These external additives may be used alone or in combination. Those subjected to a hydrophobic treatment are more preferable.

In the present invention, a suspension polymerization method under normal pressure or under pressure is particularly preferable, wherein a fine particle toner having a sharp particle size distribution and a particle size of 4 to 8 μm can be obtained relatively easily. As a specific method for encapsulating the low softening point substance, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than for the main monomer, and a small amount of a large polar resin or monomer is used. , A toner having a so-called core / shell structure in which a low softening point substance is coated with an outer shell resin can be obtained. The particle size distribution and the particle size of the toner are controlled by changing the type and amount of the hardly water-soluble inorganic salt or dispersant that acts as a protective colloid, and by mechanical device conditions (for example, rotor peripheral speed, number of passes, stirring blades). Predetermined toner particles can be obtained by controlling the shape stirring conditions and container shape) or the solid content concentration in the aqueous solution.

As a specific method for measuring the tomographic plane of the toner particles, the toner particles are sufficiently dispersed in a room temperature curable epoxy resin, and then cured in an atmosphere at a temperature of 40 ° C. for 2 days. The product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome equipped with diamond teeth. The morphology of the toner is measured using a transmission electron microscope (TEM). I do. It is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between the materials by utilizing a slight difference in crystallinity between the low softening point substance and the resin constituting the outer shell.

Examples of the shell resin include a styrene- (meth) acrylic copolymer, a polyester resin, an epoxy resin, and a styrene-butadiene copolymer. In a method for directly obtaining a toner by a polymerization method, styrene;
Styrene monomers such as (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) ) Butyl acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylate monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used. Can be These can be used alone or in the published Polymer Handbook, 2nd edition III-P1
The theoretical glass transition temperature (Tg) described in 39-192 (manufactured by John Wiley & Sons) is 40-7.
The monomers are appropriately mixed and used for polymerization so as to show 5 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems arise in terms of the storage stability of the toner and the durability stability of the developer. In the case of the toner for use, the color mixing property of each color toner is reduced, and the color reproducibility is reduced. Furthermore, the transparency of the OHP image is significantly reduced. The molecular weight of the shell resin is determined by gel permeation chromatography (G
PC). As a specific GPC measurement method, the toner is extracted in advance with a toluene solvent using a Soxhlet extractor for 20 hours, and then the toluene is distilled off with a rotary evaporator. After washing sufficiently by adding an organic solvent that cannot be dissolved, such as chloroform, and the like, a solution dissolved in THF (tetrahydrofuran) was filtered through a solvent-resistant membrane filter having a pore diameter of 0.3 μm. And the column configuration was A-801, 802, 803, 804, 805, 80 manufactured by Showa Denko.
6,807, and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve. The number average molecular weight (Mn) of the obtained resin component is 5,000 to 1,000,000,
An outer shell resin having a ratio (Mw / Mn) of 2 to 100 between the weight average molecular weight (Mw) and the number average molecular weight (Mn) is preferable in the present invention.

When producing toner particles having a core / shell structure, it is particularly preferable to add a polar resin in addition to the outer shell resin in order to cause the low softening point substance to be included in the outer shell resin. As the polar resin, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with a shell resin or a monomer in the molecule. If a polar resin having an unsaturated group is included, a cross-linking reaction occurs with the monomer forming the outer shell resin layer. Is disadvantageous and is not preferred.

An outermost shell resin layer may be further provided on the surface of the toner particles.

The glass transition temperature of the outermost resin layer is designed to be equal to or higher than the glass transition temperature of the outer resin layer in order to further improve the blocking resistance, and is crosslinked so as not to impair the fixability. Is preferred. It is preferable that the outermost resin layer contains a polar resin and a charge control agent for improving the chargeability.

The method for providing the outermost shell layer is not particularly limited, but includes, for example, the following methods.

(1) In the latter half of or after the polymerization reaction, if necessary, a monomer in which a polar resin, a charge control agent, a cross-linking agent, etc. are dissolved and dispersed is added to the reaction system, and the resulting mixture is adsorbed on polymer particles to initiate polymerization. A method of performing polymerization by adding an agent.

(2) If necessary, emulsion polymerization particles or soap-free polymerization particles composed of a monomer containing a polar resin, a charge control agent, a cross-linking agent, etc., are added to the reaction system, and aggregated on the surface of the polymerization particles. Method of fixing by heat or the like according to

(3) A method in which emulsion polymerized particles or soap-free polymerized particles made of a monomer containing a polar resin, a charge control agent, a crosslinking agent, etc., are mechanically fixed to the toner particle surfaces by a dry method as required.

In the black toner, it is preferable to use a charge control agent mixed (internally added) with toner particles or mixed (externally added) with toner particles. The charge control agent makes it possible to control the amount of charge optimally according to the development system. In particular, in the present invention, the balance between the particle size distribution and the amount of charge can be further stabilized. The following substances control the toner to be negatively charged.

For example, organic metal complexes and chelate compounds are effective. Examples thereof include a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid-based metal complex. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

The following substances are controlled as positively charged.

Modified products of nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate; and analogs thereof, such as phosphonium salts Onium salts and their lake pigments; triphenylmethane dyes and these lake pigments (as the lake-forming agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid,
Tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl And diorganotin borates such as tin borate. These can be used alone or in combination of two or more.

The charge control agent described above is preferably used in the form of fine particles. The number average particle size of these charge control agents is particularly preferably 4 μm or less, more preferably 3 μm or less. When these charge control agents are internally added to the toner particles, 0.1 to 20 parts by weight, particularly 0.2
It is preferred to use from 10 to 10 parts by weight.

Examples of the black colorant include carbon black, a magnetic substance, and a black color tone using the following yellow / magenta / cyan colorants.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Examples include compounds represented by azo metal complexes, methine compounds, and allylamide compounds. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 97, 109, 1
10, 111, 120, 127, 128, 129, 14
7, 168, 174, 176, 180, 181, 191
Is preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 are particularly preferred.

Examples of the cyan coloring agent include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66 can be particularly preferably used.

These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant is selected in terms of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in toner particles. The addition amount of the non-magnetic coloring agent is preferably 1 to 20 parts by weight based on 100 parts by weight of the resin.

As the magnetic material, there is a metal oxide containing elements such as iron, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. Among them, those containing iron oxide as a main component, such as triiron tetroxide and γ-iron oxide, are preferred. It may contain a metal element such as a silicon element or an aluminum element from the viewpoint of controlling the chargeability of the toner. These magnetic particles preferably have a BET specific surface area of ^{2 to} 30 m ² / g, particularly 3 to 28 m ² / g by a nitrogen adsorption method.
And a magnetic material having a Mohs hardness of 5 to 7 is preferable.

The shape of the magnetic material may be octahedron, hexahedron,
Examples include spheres, needles, and scales. Those having low anisotropy, such as octahedron, hexahedron, and sphere, are preferable for increasing the image density. The average particle size of the magnetic material is 0.05 to
1.0 μm is preferred, and more preferably 0.1 to 0.1 μm.
6 μm, and more preferably 0.1 to 0.4 μm.

The magnetic material is 30 parts by weight with respect to 100 parts by weight of the binder resin.
-200 parts by weight, preferably 40-200 parts by weight, more preferably 50-150 parts by weight. If the amount is less than 30 parts by weight, in a developing device that uses a magnetic force to transport the toner, the transportability is reduced, and the developer layer on the developer carrier tends to be uneven, resulting in image unevenness. The image density tends to decrease due to the increase.
On the other hand, if it exceeds 200 parts by weight, a problem tends to occur in the fixing property.

As the inorganic fine powder mixed with the toner particles, known inorganic powders are used. In order to improve charging stability, developability, fluidity, and storage stability, it is preferable to select from silica fine powder, alumina fine powder, titania fine powder, or a fine powder of a composite oxide thereof. Particularly, silica fine powder is preferable. As the silica, dry silica produced by vapor phase oxidation of silicon halide or alkoxide and wet silica produced from alkoxide, water glass and the like can be used.
Dry silica having less silanol groups on the surface and in the interior of the silica fine powder and having less production residues such as Na ₂ O and SO ₃ ^2- is preferred. In the case of fumed silica, it is possible to obtain a composite fine powder of silica and another metal oxide by using a metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the manufacturing process. You may.

[0109] Inorganic fine powder used in the present invention is the specific surface area by nitrogen adsorption measured by BET method is 30 m ² / g or more, particularly in the range of 50 to 400 m ² / g give good results. 0.1 to 8 parts by weight of silica fine powder, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of toner particles
More preferably, the amount is 1.0 to 3.0 parts by mass.

The inorganic fine powder used in the present invention preferably has a primary particle size of 30 nm or less.

The inorganic fine powder used in the present invention may be used, if necessary, for the purpose of hydrophobization, charge control, etc., silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, functional groups. It is preferable to be treated with a treating agent such as a silane coupling agent having the above, another organosilicon compound or an organotitanium compound. Two or more treatment agents may be used in combination.

In order for the toner to maintain a high charge amount and achieve a low consumption and a high transfer rate, it is more preferable that the inorganic fine powder is treated with at least silicone oil.

In the present invention, in order to improve the transferability and / or the cleaning property, in addition to the inorganic fine powder, the primary particle size is more than 30 nm (preferably, the specific surface area is less than 50 m ² / g). Preferably, 50n
It is also a preferable embodiment to further add inorganic or organic particles having a spherical shape of at least m (preferably having a specific surface area of less than 30 m ² / g). For example, spherical silica particles, spherical polymethylsilsesquioxane particles, and spherical resin particles are preferably used.

Further additives may be used within a range that does not substantially affect the toner. Lubricant powders such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder; cerium oxide powder, silicon carbide powder,
An abrasive such as strontium titanate powder; a fluidity-imparting agent such as aluminum oxide powder; an anti-caking agent; a conductivity-imparting agent such as carbon black powder, zinc oxide powder, and tin oxide powder; Inorganic fine particles.

As the inorganic fine powder to be externally added to the yellow toner, magenta toner and cyan toner, a specific coupling agent is treated while being hydrolyzed in the presence of water, and has an average particle diameter of 0.01 to 0.2 μm and a hydrophobicity. 400 at 20-98%
Titanium oxide or alumina having a light transmittance of 40% or more in nm is preferable. Uniform hydrophobic treatment can be performed in water, stabilization of toner charge without coalescence of particles,
It is extremely effective in providing fluidity.

By subjecting the inorganic fine particles to a surface treatment while hydrolyzing the coupling agent while mechanically dispersing the inorganic fine particles to have a primary particle size in the presence of water, coalescence of the particles hardly occurs. And the inorganic fine particles are surface-treated in a state of substantially primary particles.

When the surface is treated while hydrolyzing the coupling agent in the presence of water, a mechanical force for dispersing the inorganic fine particles into the primary particles is applied, so that a gas such as chlorosilanes or silazanes is applied. It is not necessary to use a coupling agent that makes the particles viscous, and a high-viscosity coupling agent or silicone oil, which cannot be used because the particles are united, can also be used.

Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. Particularly preferred is a silane coupling agent, for example, those represented by the following general formula.

R _m SiY _{n wherein} R represents an alkoxy group, m represents an integer of 1 to 3, Y represents an alkyl group, a vinyl group, a glycidoxy group,
It represents a hydrocarbon group such as a methacryl group, and n represents an integer of 1 to 3. ] For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, Trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-
Octadecyltrimethoxysilane can be mentioned.

More preferably, a trialkoxyalkylsilane coupling agent represented by the following formula is preferred.

[0121] In _{C a H 2a + 1 -Si (} OC b H 2b + 1) 3 [ wherein, a is an integer of 4 to 12, b is an integer of 1-3. When a is smaller than 4, the treatment becomes easy, but the hydrophobicity is reduced. When a is larger than 12, the hydrophobicity is sufficient, but the particles are easily united. If b is greater than 3, the reactivity decreases. a is 4 to 12, preferably 4 to 8, b is 1 to
3, preferably 1-2.

The treatment amount is 1 to 50 parts by weight, preferably 3 to 40 parts by weight, per 100 parts by weight of the inorganic fine powder. Hydrophobicity is 20-98%, more preferably 30-90%,
More preferably, 40 to 80% is good.

When the degree of hydrophobicity is less than 20%, the amount of charge after long-term storage under high humidity tends to decrease.
If it exceeds 8%, the toner tends to charge up under low humidity.

The particle size of the hydrophobized inorganic fine powder is preferably 0.01 to 0.2 μm from the viewpoint of improving the fluidity of the toner particles. When the particle size is larger than 0.2 μm, the uniformity of the charging of the toner is reduced, and as a result, toner scattering and fogging are likely to occur. When the thickness is less than 0.01 μm, the toner particles are easily embedded on the surface of the toner particles, the toner is easily deteriorated, and the durability is easily lowered.

As the above-mentioned treatment method, it is effective to carry out the treatment by hydrolyzing the coupling agent while mechanically dispersing the coupling agent so as to have a primary particle diameter in an aqueous medium.

Further, the light transmittance at a light wavelength of 400 nm of the inorganic fine particles subjected to the hydrophobic treatment as described above is as follows.
It is preferably at least 40%.

In order to improve the transfer property and / or the cleaning property, inorganic or organic fine particles having a primary particle size of 50 nm or more (preferably having a specific surface area of less than 30 m ² / g) are preferably added. One. For example, spherical silica particles, spherical polymethylsilsesquioxane particles, and spherical resin particles are preferably used.

The black toner used in the present invention preferably contains a liquid lubricant.

Due to the small amount of the liquid lubricant covering the surface of the electrostatic latent image carrier and the intermediate transfer member and the good releasability given to the toner particles, the toner on the surface of the electrostatic latent image carrier is It can be transferred uniformly and effectively onto the transfer material.

It is preferable that the liquid lubricant is carried by carrier particles such as magnetic material by means of adsorption, granulation, aggregation, impregnation, or inclusion, and is contained in the toner particles. As a result, a uniform and appropriate amount of the liquid lubricant can be present on the surface of the toner particles, and the releasability and lubricity of the toner particles can be stabilized.

As the liquid lubricant for imparting releasability and lubricity to the toner, animal oil, vegetable oil, petroleum-based lubricating oil, synthetic lubricating oil and the like are used, and synthetic lubricating oil is preferably used in view of its stability. Synthetic lubricating oils include silicones such as dimethyl silicone, methyl phenyl silicone and various modified silicones; polyol esters such as pentaerythritol ester and trimethylol propane ester; polyolefins such as polyethylene, polypropylene, polybutene and poly α-olefin; Polyglycols such as polypropylene glycol; Silicates such as tetradecyl silicate and tetraoctyl silicate; Diesters such as di-2-ethylhexyl sebacate and di-2-ethylhexyl adipate; Phosphates such as trichelesyl phosphate and propyl phenyl phosphate ; Polychlorotrifluoroethylene, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene fluoride Such fluorinated hydrocarbon compounds; polyphenyl ethers, alkyl naphthenes, alkyl aromatic and the like. Among them, silicone or fluorinated hydrocarbon is preferred from the viewpoint of heat stability and oxidation stability. As silicone, amino-modified silicone, epoxy-modified silicone, carboxyl-modified silicone,
Reactive silicones such as carbinol-modified silicone, methacryl-modified silicone, mercapto-modified silicone, phenol-modified silicone, and heterofunctional group-modified silicone; polyether-modified silicone, methylstyryl-modified silicone, alkyl-modified silicone, fatty acid-modified silicone, alkoxy-modified silicone, Non-reactive silicones such as fluorine-modified silicones; dimethyl silicones,
Straight silicones such as methyl phenyl silicone and methyl hydrogen silicone are exemplified.

Since the liquid lubricant on the surface of the magnetic particles or the surface of the carrier particles is partially released and present on the surface of the toner particles, the effect is exerted. Therefore, the effect of the curable silicone is weakened due to its properties. Reactive silicones and silicones having polar groups exhibit strong adsorption to the liquid lubricant-carrying medium and exhibit compatibility with the binder resin. Depending on the degree, the amount of liberation may be small and the effect may be inferior. Even with non-reactive silicones, depending on the structure of the side chain, compatibility with the binder resin may appear and the effect may be poor.
Therefore, dimethyl silicone, fluorine-modified silicone, and fluorocarbon are preferably used because they have low reactivity and polarity, do not have strong adsorption, and have no compatibility with the binder resin. Liquid lubricant has a viscosity at 25 ° C of 100,000 to 200,000 c
St, more preferably 20 to 10
It is good to be 10,000 cSt, especially 500 to 70,000 cSt.
If it is less than 10 cSt, low molecular weight components increase, so that problems tend to occur in developability and storage stability. If it exceeds 200,000 cSt, migration and dispersion in the toner particles are likely to be non-uniform, and problems such as developability, transferability, and anti-contamination are likely to occur.

The measurement of the viscosity of the liquid lubricant is performed using a Visco Tester VT500 (manufactured by Haake). One of several viscosity sensors for VT500 is arbitrarily selected, and a measurement material is put in a cell for the sensor to measure. The viscosity (pas) displayed on the device is converted to cSt.

Since the liquid lubricant is used by being supported on a magnetic substance or carrier particles, the dispersibility is better than simply adding a liquid lubricant such as silicone as it is. The purpose is not merely to improve the dispersibility, but to release the liquid lubricant from the carrier particles to exert its releasability and lubricity. Need to be prevented.

The amount of the liquid lubricant on the surface of the toner particles can be appropriately adjusted by holding the liquid lubricant on the surface of the carrier particles and causing the liquid lubricant to be present on or near the surface of the toner particles.

As a specific method of supporting the liquid lubricant on the surface of the magnetic material, a wheel-type kneader or the like is used. When a wheel-type kneader or the like is used, the liquid lubricant interposed between the magnetic particles is pressed against the surface of the magnetic particles by the compression action, and is spread through the particle gap to increase the adhesion to the particle surface. While the liquid lubricant is stretched by the shearing action, the position of the particles is changed by the shearing force to disperse the cohesion, and the liquid lubricant existing on the particle surface is evenly spread by the action of a spatula. By repeating the operation, the cohesion between the magnetic particles is loosened, and the particles become one by one.
It is particularly preferable because it is uniformly supported on the surface of each particle in a discrete state. As the wheel-type kneader, a Simpson mix muller, a multi-mul, a Stotts mill, an Erich-mill, a backflow kneader or the like can be preferably used.

Using a mixer such as a Henschel mixer or a ball mill, the liquid lubricant is directly mixed with the magnetic particles and supported by being diluted with a solvent or the like, or is directly sprayed and supported on the magnetic particles. However, in the case of magnetic particles, it is difficult to uniformly carry a small amount of liquid lubricant on a carrier, or liquid lubrication is locally applied due to shearing force, heat, etc. Since the agent is firmly adsorbed or seizure occurs in the case of silicone or the like, the liquid lubricant may not be effectively released from the carrier.

Regarding the amount of the liquid lubricant carried on the magnetic material, the relative amount of the liquid lubricant to the binder resin is important from the viewpoint of the effect. The optimum range is preferably added to the magnetic material so that the amount of the liquid lubricant is 0.1 to 7 parts by weight with respect to 100 parts by weight of the binder resin.
More preferably, it is 0.2 to 5 parts by weight, and particularly preferably 0.1 to 5 parts by weight.
3 to 2 parts by weight is good.

As the lubricating support particles containing a liquid lubricant, in addition to the magnetic material, fine particles of an organic compound or an inorganic compound granulated or agglomerated with a liquid lubricant are used as the lubricating support particles. You.

Examples of the organic compound include resin particles such as styrene resin, acrylic resin, silicone resin, polyester resin, urethane resin, polyamide resin, polyethylene resin, and fluorine resin. Examples of the inorganic compound constituting the inorganic fine particles include SiO ₂ , GeO ₂ , TiO ₂ ,
Oxides such as SnO ₂ , Al ₂ O ₃ , B ₂ O ₃ , P ₂ O ₅ ; silicates, borates, phosphates, borosilicates, aluminosilicates, aluminoborates, aluminoborosilicates ,
Metal oxide salts such as tungstates, molybdates, and tellurates, and composite compounds thereof, silicon carbide, silicon nitride, and amorphous carbon. These can be used alone or in combination.

Among these, inorganic compounds are particularly preferable in terms of having an appropriate electric resistance value, and metal oxides are particularly preferable. In particular,
Oxides and double oxides of Si, Al and Ti are preferred. In particular, when used for a color toner other than a black toner, a substantially white inorganic compound is preferably used.

[0142] A fine particle surface which has been previously made hydrophobic with a coupling agent may be used. However, some liquid lubricants tend to be overcharged when the surface of the toner particles is covered. If a non-hydrophobic carrier is used as a carrier, appropriate leakage of charges can be performed, and good developability can be maintained. Therefore, use of a carrier that has not been subjected to a hydrophobizing treatment is also one of preferred embodiments.

The particle size of the carrier fine particles is preferably from 0.001 to 20 μm, particularly preferably from 0.005 to 10 μm. The specific surface area by nitrogen adsorption measured by the BET method is 5 to 500 m ² / g, more preferably 10 to 400 m ² / g.
m ² / g, more preferably 20~350m ² / g is good. If it is less than 5 m ² / g, it is difficult to hold the liquid lubricant as lubricating particles having a suitable particle size.

The amount of the liquid lubricant in the lubricating carrier particles is
20-90% by weight, preferably 27-87% by weight, particularly preferably 40-80% by weight. When the amount of the liquid lubricant is less than 20% by weight, the effect of imparting good lubricity and releasability to toner particles is small. If it exceeds 90% by weight, it is difficult to obtain lubricating carrier particles containing the liquid lubricant uniformly.

The particle size of the lubricating carrier particles is preferably 0.5 μm or more, more preferably 1 μm or more so that the liquid lubricant can be released while being held. It is also preferable that the main component in the volume-based distribution is larger than the particle size of the toner particles. Since these lubricating carrier particles contain a large amount of liquid lubricant and are fragile, during the production of the toner, a part thereof is broken and uniformly dispersed in the toner particles, and at the same time, the liquid lubricant is released to provide lubricity and separation to the toner particles. You can give it type. On the other hand, the lubricating particles can be present in the toner particles while maintaining the ability to retain the liquid lubricant.

Therefore, deterioration of the fluidity and developability of the toner can be prevented without excessively transferring the liquid lubricant to the surface of the toner particles. On the other hand, since the lubricant can be replenished from the lubricating particles even when the liquid lubricant partially detaches from the surface of the toner particles, the releasability and lubricity of the toner particles can be maintained for a long time. These lubricating carrier particles can be granulated by a method in which droplets of a solution diluted with a liquid lubricant or an arbitrary solvent are adsorbed to carrier fine particles in a mixer, and the solvent is volatilized after granulation and further required. It may be crushed accordingly. Alternatively, a liquid lubricant or a diluent thereof is added to the carrier particles using a kneader, and the mixture is kneaded, and if necessary, pulverized and granulated, and the solvent is then volatilized. As described above, the lubricating carrier particles are preferably contained in an amount of 0.01 to 50 parts by weight, more preferably 0.05 to 50 parts by weight, particularly preferably 0.1 to 2 parts by weight based on 100 parts by weight of the binder resin.
0 parts by weight is good. If the amount is less than 0.01 part by weight, the effect of addition is small, and if it exceeds 50 parts by weight, a problem is likely to occur in charging stability.

As the lubricating carrier particles, porous powder impregnated with a liquid lubricant and encapsulated therein can be used.

Examples of the porous powder include clay minerals such as zeolite, molecular sieve and bentonite, aluminum oxide, titanium oxide, zinc oxide and resin gel.
The particle size of a porous powder, such as a resin gel, which does not disintegrate in the kneading step during toner production, is not limited. On the other hand, the particle size of the porous powder that is difficult to collapse is preferably 15 μm or less as the primary particle size. If it exceeds 15 μm, the dispersion in the toner particles tends to be non-uniform.
The specific surface area of the porous powder before impregnating with the liquid lubricant was 10 to 50 m ² / by nitrogen adsorption measured by the BET method.
g is preferred. If it is less than 10 m ² / g, it is difficult to hold a large amount of liquid lubricant, and if it exceeds 50 m ² / g, the pore diameter is small and the liquid lubricant is not sufficiently impregnated in the pores. As a method of impregnating the porous powder, the porous powder can be produced by a method of subjecting the porous powder to a reduced pressure treatment and immersing it in a liquid lubricant. The porous powder impregnated with the liquid lubricant is preferably mixed in a range of 0.1 to 20 parts by weight with respect to 100 parts by weight of the binder resin. If the amount is less than 0.1 part by weight, the effect of addition is small, and if it exceeds 20 parts by weight, a problem is likely to occur in the charging stability of the toner. In addition to these, capsule type lubricating particles containing liquid lubricant and liquid lubricant dispersed inside, containing,
Expanded and impregnated resin particles can also be used.

In the electrostatic latent image carrier used in the present invention, the contact angle of water on the surface of the electrostatic latent image carrier is preferably 85 degrees or more (preferably 90 degrees or more). When the contact angle with water is 85 degrees or more, the transfer rate of the toner image is improved, and toner filming hardly occurs.

The image forming method of the present invention is particularly effective when the surface of the electrostatic latent image carrier is mainly composed of a polymer binder. For example, when a protective film mainly composed of a resin is provided on an inorganic photosensitive layer such as selenium or amorphous silicon; when a charge transporting layer of a functionally separated organic photosensitive layer has a surface layer composed of a charge transporting material and a resin; Further, there is a case where the above protective layer is provided thereon. Means for imparting release properties to such a surface layer include the following. (1) A resin having a low surface energy is used as a resin constituting the layer. (2) Add an additive that imparts water repellency and lipophilicity. (3) A material having high releasability is powdered and dispersed. The means (1) can be achieved by introducing a fluorine-containing group or a silicon-containing group into the structure of the resin. As means (2), a surfactant or the like may be used as an additive. Means (3) include powders of fluorine-containing compounds such as polytetrafluoroethylene, polyvinylidene fluoride, and carbon fluoride. Among them, polytetrafluoroethylene is particularly preferable. In the present invention, the dispersion of the releasable powder such as a fluororesin in the outermost surface layer of the means (3) is particularly preferable.

In order to include these powders on the surface, a layer in which the powders are dispersed in a binder resin is provided on the outermost surface of the electrostatic latent image carrier, or the resin is mainly constituted. As long as the organic photosensitive layer has such a configuration, the powder may be dispersed in the uppermost layer without providing a new surface layer.

The amount of the powder to be added to the surface layer is 1 to 60% by weight, more preferably 2 to 5% by weight, based on the total weight of the surface layer.
0% by weight is good. If it is less than 1% by weight, the effect of improvement is small, and if it exceeds 60% by weight, the strength of the film is reduced, and the amount of light incident on the electrostatic latent image carrier is undesirably reduced.

The present invention is particularly effective when the charging means is a direct charging method in which the charging member is brought into contact with the electrostatic latent image carrier. Since the load on the surface of the electrostatic latent image carrier is larger than that of corona discharge in which the charging means does not contact the electrostatic latent image carrier, the improvement effect is remarkable in terms of the life of the electrostatic latent image carrier.

Examples of preferred embodiments of the electrostatic latent image carrier used in the present invention will be described below.

Materials for forming the conductive substrate include metals such as aluminum and stainless steel; aluminum alloys;
Plastics having a coating layer of an alloy such as an indium oxide-tin oxide alloy; paper and plastic impregnated with conductive particles; and plastics having a conductive polymer. As the substrate, a cylindrical cylinder and a film are used.

On these conductive substrates, the adhesion of the photosensitive layer is improved, the coating properties are improved, the substrate is protected, the defects on the substrate are covered,
An undercoat layer may be provided for the purpose of improving the charge injection property from the substrate and protecting the photosensitive layer against electrical breakdown. The undercoat layer is made of polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, casein, polyamide, copolymerized nylon, glue,
It is formed of materials such as gelatin, polyurethane, and aluminum oxide. The film thickness is usually 0.1 to 10 μm
m, preferably 0.1 to 3 μm.

The charge generation layer is made of an organic material such as an azo pigment, a phthalocyanine pigment, an indigo pigment, a perylene pigment, a polycyclic quinone pigment, a squarylium dye, a pyrylium salt, a thiopyrylium salt, a triphenylmethane dye; A charge generation material made of an inorganic material such as amorphous silicon is dispersed in an appropriate binder, and is formed by coating or vapor deposition. As the binder, a wide range of binder resins can be selected. For example, a polycarbonate resin, a polyester resin, a polyvinyl butyral resin, a polystyrene resin, an acrylic resin, a methacryl resin, a phenol resin, a silicone resin, an epoxy resin, and a vinyl acetate resin are exemplified. The amount of the binder contained in the charge generation layer is 80% by weight or less, preferably 0 to 40% by weight. The thickness of the charge generation layer is 5 μm or less, particularly 0.05 to 2 μm.
Is preferred.

The charge transport layer has a function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting them. The charge transporting layer is formed by dissolving a charge transporting substance in a solvent together with a binder resin as required, and applying the solution. The thickness is generally 5 to 40 μm.
Examples of the charge transport material include polycyclic aromatic compounds having a structure such as biphenylene, anthracene, pyrene, or phenanthrene in the main chain or side chain; nitrogen-containing cyclic compounds such as indole, carbazole, oxadiazole, and pyrazoline; hydrazone compounds; Styryl compounds; inorganic compounds such as selenium, selenium-tellurium, amorphous silicon, and cadmium sulfide;

Examples of the binder resin for dispersing these charge transport materials include polycarbonate resin, polyester resin,
Resins such as polymethacrylate, polystyrene resin, acrylic resin and polyamide resin; and organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene.

As the surface layer, a protective layer may be provided. Examples of the resin of the protective layer include polyester, polycarbonate, acrylic resin, epoxy resin, phenol resin, and those obtained by curing these resins with a curing agent. These are used alone or in combination of two or more.

Conductive fine particles may be dispersed in the resin of the protective layer. Examples of the conductive fine particles include fine particles of metal or metal oxide. Preferably, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide,
There are fine particles of materials such as bismuth oxide, tin oxide coated titanium oxide, tin coated indium oxide, antimony coated tin oxide, and zirconium oxide. These may be used alone or as a mixture of two or more. Generally, when the conductive fine particles are dispersed in the protective layer, it is preferable that the particle diameter of the conductive fine particles is smaller than the wavelength of the incident light in order to prevent scattering of the incident light by the conductive fine particles. The particle size of the conductive fine particles dispersed in the protective layer is preferably 0.5 μm or less. The content in the protective layer is preferably from 2 to 90% by weight, more preferably from 5 to 80% by weight, based on the total weight of the protective layer. The thickness of the protective layer is preferably from 0.1 to 10 μm, more preferably from 1 to 7 μm.

The surface layer can be applied by spray coating, beam coating or permeation coating of the resin dispersion.

When the one-component developing method is used in the present invention, in order to obtain high image quality, the distance between the toner carrier and the electrostatic latent image carrier is smaller than the closest distance (between SD) on the toner carrier. It is preferable that the layer is developed in a developing step of applying a magnetic toner and developing by applying an alternating electric field.

The surface roughness of the toner carrier used in the present invention is 0.2 to 3.5 in terms of JIS center line average roughness (Ra).
It is preferably in the range of μm.

If Ra is less than 0.2 μm, the charge amount on the toner carrier tends to be high, and the developability tends to be low. R
If a exceeds 3.5 μm, the toner coat layer on the toner carrier tends to be uneven. More preferably, 0.5
It is preferably in the range of ~ 3.0 [mu] m.

Further, since the magnetic toner of the present invention has a high charging ability, it is preferable to control the total charge amount of the toner during development. The surface of the toner carrier is preferably covered with a resin layer in which conductive fine particles and / or a lubricant are dispersed.

Examples of the conductive fine particles contained in the resin layer covering the surface of the toner carrier include conductive metal oxides such as carbon black, graphite, and conductive zinc oxide, and metal double oxides. These are preferably used alone or in combination of two or more. As the resin in which the conductive fine particles are dispersed, phenolic resin, epoxy resin, polyamide resin, polyester resin, polycarbonate resin, polyolefin resin, silicone resin,
A resin such as a fluorine resin, a styrene resin, and an acrylic resin is used. In particular, a thermosetting or photocurable resin is preferable.

It is particularly preferable that the member for regulating the toner on the toner carrier is regulated by an elastic member which is in contact with the toner carrier via the toner, from the viewpoint of uniformly charging the magnetic toner. In the present invention, it is more preferable from the viewpoint of environmental protection that the charging member and the transfer member are in contact with the electrostatic latent image carrier so that ozone is not generated.

Next, the image forming method of the present invention will be described more specifically with reference to FIG.

In the apparatus system shown in FIG. 1, the developing units 4-1, 4-2, 4-3, and 4-4 have a developer containing a cyan toner and a developer containing a magenta toner, respectively.
A developer having a yellow toner and a developer having a black toner were introduced, and were formed on the photosensitive member 1 as an electrostatic latent image carrier by a magnetic brush developing method, a non-magnetic one-component developing method, or a magnetic jumping developing method. The electrostatic latent image is developed, and toner images of each color are sequentially formed on the photoconductor 1. Photoconductor 1 is made of amorphous selenium, cadmium sulfide,
It is a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as zinc oxide, an organic photoconductor, and amorphous silicon. The photoconductor 1 is rotated in a direction indicated by an arrow by a driving device (not shown). As the photosensitive member 1, a photosensitive member having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generating substance and a substance having charge transporting ability in the same layer, or a functional separation type photosensitive element comprising the charge transporting layer and the charge generating layer as components. It may be a layer. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.

As the binder resin of the organic photosensitive layer, polycarbonate resin, polyester resin and acrylic resin have particularly good cleaning properties, and poor cleaning, toner fusion to the photosensitive member, and filming hardly occur.

In the present invention, in the charging step, there are a method of non-contact with the photoreceptor 1 using a corona charger and a method of contact type using a charging roller, a charging brush or a charging belt, and both types are used. Efficient uniform charging,
For simplicity and low ozone generation, a contact charging system is preferably used as shown in FIG.

The charging roller 2 basically has a core 2b at the center and a conductive elastic layer 2a having an outer periphery. The charging roller 2 is pressed against the surface of the photoconductor 1 with a pressing force, and rotates in cooperation with the rotation of the photoconductor 1.

The preferable process condition when the charging roller 2 is used is that the contact pressure of the charging roller 2 is 5 to 5
00 g / cm, and when a DC voltage with an AC voltage superimposed thereon is used, the AC voltage is 0.5 to 5 kVpp, the AC frequency is 50 to 5 kHz, and the DC voltage is ± 0.2 to ± 5 kV. It is.

Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means have the effects of eliminating the need for high voltage and reducing the generation of ozone.

As the material of the charging roller and the charging blade as the contact charging means, conductive rubber is preferable, and a release film may be provided on the surface thereof. Nylon-based resin, polyvinylidene fluoride (PVD)
F), polyvinylidene chloride (PVDC), fluorine acrylic resin and the like are applicable.

The toner image on the photosensitive member 1 is applied with a voltage (for example, ±
(0.1 to ± 5 kV). As shown in FIG. 8, the intermediate transfer member may be a belt-shaped intermediate transfer member having a transfer belt 13 and a bias unit 13a. The intermediate transfer member 5 is a pipe-shaped conductive metal core 5b.
And a middle resistance elastic layer 5a having an outer peripheral surface thereof.
The cored bar 5b may be provided with a conductive layer (for example, conductive plating) on the surface of plastic.

The medium resistance elastic layer 5a is formed of an elastic material such as silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber, ethylene propylene diene terpolymer (EPDM), carbon black, zinc oxide, tin oxide, silicon carbide, or the like. This is a solid or foamed layer in which an electric resistance value (volume resistivity) is adjusted to a medium resistance of 10 ⁵ to 10 ¹¹ Ωcm by mixing and dispersing a conductivity imparting agent such as

The intermediate transfer member 5 is arranged in parallel with the photosensitive member 1 so as to be in contact with the lower surface of the photosensitive member 1 and is rotated at the same peripheral speed as the photosensitive member 1 in a counterclockwise direction indicated by an arrow. I do.

The first color toner image on the surface of the photosensitive member 1 is formed in the transfer nip portion by the transfer bias applied to the intermediate transfer member 5 while passing through the transfer nip portion where the photosensitive member 1 and the intermediate transfer member 5 are in contact with each other. The electric field is transferred onto the intermediate transfer member 5.

A transfer means is provided so as to be supported in parallel with the intermediate transfer member 5 and to contact the lower surface of the intermediate transfer member 5. The transfer unit is, for example, a transfer roller 7, and rotates in the clockwise direction indicated by an arrow at the same peripheral speed as the intermediate transfer body 5. The transfer roller 7 may be arranged so as to directly contact the intermediate transfer member 5, or may be arranged so that the transfer belt 12 contacts between the intermediate transfer member 5 and the transfer roller 7 as shown in FIG. good.

The transfer roller 7 basically has a core metal 7b at the center and a conductive elastic layer 7a forming the outer periphery thereof.

As the intermediate transfer member and transfer means used in the present invention, general materials can be used.
In the present invention, the voltage applied to the transfer means can be reduced by setting the volume resistivity of the transfer member smaller than the volume resistivity of the intermediate transfer member, and a good toner image can be formed on the transfer material. The winding of the transfer material around the intermediate transfer member can be prevented. In particular, it is preferable that the volume resistivity of the elastic layer of the intermediate transfer member is at least 10 times the volume resistivity of the elastic layer of the transfer means.

The hardness of the intermediate transfer member and the transfer means is determined according to JIS.
It is measured according to K-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to the range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer means is higher than the hardness of the elastic layer of the intermediate transfer member. ~ 8
Those having a value of 0 degrees are preferred in order to prevent the transfer material from winding around the intermediate transfer member. If the hardness of the transfer unit is higher than that of the intermediate transfer body, a concave portion is formed on the intermediate transfer body side, and the winding of the transfer material around the intermediate transfer body is prevented.

The transfer roller 7 is rotated at a constant speed or at a different peripheral speed from the intermediate transfer member 5. The transfer material 6 is conveyed between the intermediate transfer member 5 and the transfer roller 7, and at the same time, a bias having a polarity opposite to the triboelectric charge of the toner is applied to the transfer roller 7 from the transfer bias unit, so that the transfer material 6 is transferred onto the transfer member 7. Is transferred to the front side of the transfer material 6.

As the material of the transfer roller 7, the same material as the charge roller can be used. As preferable transfer process conditions, the contact pressure of the transfer roller 7 is set to 2.
94 to 490 N / m (3 to 500 g / cm), more preferably 19.6 N / m to 294 N / m, and the DC voltage is ± 0.2 to ± 10 kV.

When the linear pressure as the contact pressure is from 2.94 N / m to 490 N / m, the transfer of the transfer material and the occurrence of transfer failure are unlikely to occur.

The conductive elastic layer 7a of the transfer roller 7 is formed by mixing and dispersing a conductivity imparting agent such as carbon black, zinc oxide, tin oxide, or silicon carbide with an elastic material such as polyurethane rubber or EPDM to obtain an electric resistance value (volume). 10)
^{6-10 10} to adjust the resistance in the [Omega] cm, a layer of a solid or foamed meat.

Next, the transfer material 6 is conveyed to a fixing unit 11 having a heating roller having a built-in heating element such as a halogen heater and an elastic pressure roller pressed against the heating roller with a pressing force. Heat and pressure is fixed to the transfer material by passing between the roller and the pressure roller.
A fixing method using a heater via a film may be used.

[0191]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Production Examples and Examples, but this does not limit the present invention in any way.

The electrophotographic apparatus used in the present invention will be described in detail.

FIG. 1 is a sectional view of an electrophotographic apparatus used in the first embodiment. The photoreceptor 1 has a photosensitive layer 1b having an organic optical semiconductor on a substrate 1a, and rotates in the direction of the arrow to rotate in contact with the charging roller 2 (the conductive elastic layer 2a, the core metal 2).
According to b), the photosensitive member 1 is charged to a surface potential of about -600 V. In the exposure, an electrostatic latent image having a potential of the exposed portion of -100 V and a potential of the dark portion of -600 V is formed by turning on and off the photosensitive member 1 on the photoreceptor 1 according to digital image information. Plurality of developing units 4-1, 4-2, 4-3, 4
-4, a magenta toner, a cyan toner, a yellow toner, or a black toner is formed on the photoreceptor 1 by a reversal developing method. The toner image is transferred to the intermediate transfer member 5 (elastic layer 5a, core metal 5 as a support) for each color.
b) The image is transferred onto the intermediate transfer member 5 to form a color superimposed color development image of four colors. The transfer residual toner on the photoreceptor 1 is collected in a residual toner container 9 by a cleaner member 8.

When a toner having a high transfer efficiency is used,
A system without a simple bias roller or a cleaner member may be used.

The intermediate transfer member 5 has a pipe-shaped core 5b coated with an elastic layer 5a obtained by sufficiently dispersing a carbon black conductive material in nitrile-butadiene rubber (NBR). The hardness of the coat layer is JIS K
30 degrees and a volume resistivity of 1 according to −6301.
0 ⁹ Ω · cm. The transfer current required for transfer from the photoconductor 1 to the intermediate transfer member 5 is about 5 μA, which can be obtained by applying +2000 V from the power supply to the cored bar 5b.
After transferring the toner image from the intermediate transfer member 5 to the transfer material 6, the surface of the intermediate transfer member may be cleaned by the cleaner member 10.

The transfer roller 7 is formed by coating a 20 mm core metal 7b with a carbon black conductivity imparting member sufficiently dispersed in an EPDM foam. The elastic layer 7a used had a volume specific resistance of 10 ⁶ Ω · cm and a hardness of 35 degrees according to JIS K-6301. A voltage was applied to the transfer roller to flow a transfer current of 15 μA. As for the contaminated toner on the transfer roller 7 when the toner is collectively transferred from the intermediate transfer member 5 to the transfer material 6, a fur brush cleaner or a cleaning member-less system is generally used as a cleaning member. In the present invention, the toner has a shape factor of 110 <SF-1 ≦ 180 (preferably 120 ≦ SF−
When 1 ≦ 160) and 110 <SF−2 ≦ 140 (preferably 115 ≦ SF−2 ≦ 140), a cleaning member-less system could be adopted because of high transfer efficiency.

In the present invention, the developing units 4-1, 4-2,
Reference numerals 4-3 and 4-4 may be a two-component magnetic brush developing device or a non-magnetic one-component developing device. When using the magnetic one-component jumping development method using magnetic toner,
The black developing device 4-4 may have a developing device configuration as shown in FIG.

In FIG. 2, the electrostatic latent image on the photosensitive drum 100 is developed with a one-component magnetic toner by a developing device 140 having a stirring device 141. As shown in FIG. 2, the developing device 140 is provided with a cylindrical toner carrier 102 (hereinafter referred to as a developing sleeve) made of a non-magnetic metal such as aluminum or stainless steel in the vicinity of the photosensitive drum 100. The gap between the developing sleeve 100 and the developing sleeve 102 is about 300 mm by a sleeve / drum gap holding member (not shown) or the like.
It is maintained at μm. A magnet roller 104 is fixed concentrically with the developing sleeve 102 in the developing sleeve,
It is arranged. However, the developing sleeve 102 is rotatable. The magnet roller 104 is provided with a plurality of magnetic poles as shown in the figure. S ₁ is for development, N ₁ is for regulating the coating amount of the magnetic toner, S ₂ is for taking in / conveying the magnetic toner,
N ₂ has a function of preventing blowing of the magnetic toner.
An elastic blade 103 is provided as a member that regulates the amount of magnetic toner adhered and conveyed to the developing sleeve 102, and the amount of toner conveyed to the developing area by the contact pressure of the elastic blade 103 against the developing sleeve 102 determines the amount of the developing sleeve. The layer thickness is controlled to be smaller than that between the photosensitive drums (between SD and D). In the developing area, a DC and AC developing bias is applied between the photosensitive drum 100 and the developing sleeve 102,
The toner on the developing sleeve is transferred to the photosensitive drum 1 according to the electrostatic latent image.
It flies above 00 and becomes a visible image.

Toner Production Example 1 100 parts by weight of magnetic substance (magnetic iron oxide powder, average particle size 0.22 μm) Styrene-butyl acrylate-butyl maleate half ester copolymer (low molecular weight side peak: about 5,000, Glass transition point Tg: 58 ° C) 100 parts by weight-Negative charge control agent (iron complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is coarsely pulverized with a hammer mill, the coarsely pulverized material is finely pulverized with a jet mill, and the obtained finely pulverized material is multi-divided using the Coanda effect The toner was strictly classified by a classifier to obtain magnetic toner particles. The magnetic toner particles were subjected to a surface treatment by a thermomechanical impact force (processing temperature: 60 ° C.), and 100 parts by weight of the obtained magnetic toner particles were subjected to a hydrophobic treatment with silicone oil and hexamethyldisilazane to give a primary particle diameter of 12 nm. Dry silica (BET specific surface area after treatment: 120 m ² / g)
8 parts by weight and 0.5 parts by weight of spherical silica (BET surface area: 20 m ² / g, primary particle size: 0.1 μm) were added and mixed by a mixer to obtain a magnetic toner A.

The weight average particle diameter of the obtained magnetic toner A was 6.5 μm, the number average particle diameter was 5.3 μm,
SF-1 is 141, SF-2 is 125, B
The ET specific surface area was 5.3 m ² / cm ³ . The BET specific surface area of the magnetic toner particles was 1.7 m ² / cm ³ . Table 1 shows the physical properties of the obtained magnetic toner A. The particle size of the magnetic toner was measured using a Coulter Counter Multisizer (manufactured by Coulter).

Toner Production Example 2 The magnetic toner particles 100 obtained in Toner Production Example 1
Dry silica having a primary particle diameter of 12 nm (BET specific surface area 1
1.3 parts by weight of 60 m ² / g) were added and mixed with a mixer to obtain a magnetic toner B. Table 1 shows the physical properties of the obtained magnetic toner B.

Toner Production Example 3 90 parts by weight of magnetic substance (average particle size 0.22 μm) Styrene butyl acrylate-butyl maleate half ester copolymer (low molecular weight side peak: about 10,000, glass transition point Tg: 62) ° C) 100 parts by weight-Negative charge control agent (iron complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

The above-mentioned materials are used, the treatment temperature of the magnetic toner particles by thermomechanical impact is set to 64 ° C., and dry silica having a primary particle diameter of 8 nm hydrophobized with silicone oil as inorganic fine powder (BET specific surface area) 100m ² /
A magnetic toner C having a weight average particle size of 7.0 μm was obtained in the same manner as in Toner Production Example 1 except that 1.8 parts by weight of g) was used. Table 1 shows the physical properties of the obtained magnetic toner C.

Toner Production Example 4 1.8 parts by weight of dry silica (BET specific surface area: 120 m ² / g) having a primary particle diameter of 12 nm and subjected to hydrophobic treatment with silicone oil and hexamethyldisilazane as inorganic fine powder, and spherical silica (BET) Specific surface area 5m ² / g, primary particle size 1μ
m) Magnetic toner D was obtained in the same manner as in Toner Production Example 1 except that 0.5 part by weight was used. Magnetic toner D obtained
Table 1 shows the physical properties of the compound.

Toner Production Examples 5 and 6 Titanium oxide fine particles having a primary particle diameter of about 20 nm (BET specific surface area 1
00m ² / g), except for using 1.5 parts by weight respectively of alumina fine particles (BET specific surface area 90m ² / g) of the primary particle size of about 20nm in the same manner as in Toner Production Example 1 to obtain a magnetic toner E and F . Table 1 shows the physical properties of the obtained magnetic toners E and F.

Toner Production Example 7 (Comparative Production Example) A magnetic toner G was obtained in the same manner as in Toner Production Example 1, except that the surface treatment was not performed by thermomechanical impact. Table 1 shows the physical properties of the obtained magnetic toner G.

Toner Production Example 8 110 parts by weight of magnetic substance (average particle size 0.24 μm) 100 parts by weight of polyester resin (low molecular weight side peak: about 7000, glass transition point Tg: 63 ° C.) 100 parts by weight (Chromium complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

A weight average particle size of 6.7 μm was obtained in the same manner as in Toner Production Example 1 except that the above-mentioned materials were used, and the processing temperature of the toner particles due to thermomechanical shock was set at 64 ° C.
Magnetic toner H was obtained. Table 1 shows the physical properties of the obtained magnetic toner H.

Toner Production Example 9 (Comparative Production Example) 60 parts by weight of magnetic material (average particle size 0.22 μm) Styrene-butyl acrylate copolymer (low molecular weight side peak: about 18,000, glass transition point Tg: 71) ° C) 100 parts by weight-Negative charge control agent (iron complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is coarsely pulverized with a hammer mill, the coarsely pulverized material is finely pulverized with a jet mill, and the obtained finely pulverized material is multi-divided using the Coanda effect The toner was strictly classified by a classifier to obtain magnetic toner particles. Dry silica having a primary particle size of about 16 nm (hydrophobized with hexamethyldisilazane) (having a BET specific surface area of 1 after treatment) was added to 100 parts by weight of the obtained magnetic toner particles.
(00 m ² / g), and the mixture was mixed with a mixer to obtain Magnetic Toner I. The weight average particle diameter of the obtained magnetic toner I was 12 μm. Table 1 shows the physical properties of the obtained magnetic toner I.

Toner Production Example 10 (Comparative Production Example) A magnetic toner J was obtained in the same manner as in Toner Production Example 1, except that the inorganic fine powder was not externally added to the toner particles. Table 1 shows the physical properties of the obtained magnetic toner J.

Toner Production Examples 11 to 14 (Non-magnetic toner
Production Example) In a 2-liter four-necked flask equipped with a high-speed stirrer TK-Homomixer, 710 parts by weight of ion-exchanged water and 0.1 ml
450 parts by weight of a 1 mol / liter-Na ₃ PO ₄ aqueous solution was added, the rotation speed was adjusted to 12,000 rpm, and the mixture was heated to 65 ° C. Here, 68 parts by weight of a 1.0 mol / liter CaCl ₂ aqueous solution was gradually added to prepare an aqueous dispersion medium containing a minute poorly water-soluble dispersant Ca ₃ (PO ₄ ) ₂ .

Styrene monomer 165 parts by weight n-butyl acrylate monomer 35 parts by weight Divinylbenzene monomer 0.5 part by weight Cyan colorant (CI Pigment Blue 15: 3) 14 parts by weight Part: Saturated polyester resin 10 parts by weight (terephthalic acid-propylene oxide-modified bisphenol A, acid value 15 mg KOH / g) Negative charge control agent (metal dialkylsatilylate) 2 parts by weight Release agent (ester wax) 40 Parts by weight

After dispersing the above materials for 3 hours using an attritor, 2,2′-azobis (2,2) as a polymerization initiator was dispersed.
The polymerizable monomer composition to which 10 parts by weight of 4-dimethylvaleronitrile was added was added to an aqueous dispersion medium, and the number of rotations was 12;
The granulation was carried out for 15 minutes while maintaining 000 rpm. Then change the stirrer from a high-speed stirrer to a propeller stirring blade and adjust the internal temperature to 8
The temperature was raised to 0 ° C., and polymerization was continued at 50 rpm for 10 hours. After the polymerization was completed, the slurry was cooled, and diluted hydrochloric acid was added to remove the dispersant.

After further washing and drying, the weight average diameter was 6.
2 μm, SF-1 is 107, SF-2 is 1
Fifteen non-magnetic negatively charged cyan toner particles were obtained. To 100 parts by weight of the obtained cyan toner particles, 2.0 parts by weight of titanium oxide fine particles having a primary particle diameter of about 20 nm (BET specific surface area: 100 m ² / g) hydrophobicized with silicone oil were externally added to obtain excellent fluidity. A cyan toner K was obtained.

The other yellow toner, magenta toner and black toner use C.I. I. Pigment Yellow 17, C.I. I. Pigment Red 202 and grafted carbon black, and the same color toners (yellow toner L, magenta toner M, and black toner N) were obtained in the same manner. The above four color toners and a silicone resin-coated magnetic ferrite carrier having an average particle size of about 50 μm were respectively mixed into 6:
The two components were mixed at a weight ratio of 94 to prepare a two-component developer for magnetic brush development of each color. Table 1 shows the physical properties of each color toner.

Toner Production Examples 15 to 18 (Non-magnetic toner
Production Example) 100 parts by weight of polyester resin (low molecular weight side peak: 6000, glass transition point Tg: 55 ° C.) 7 parts by weight of colorant (CI pigment blue 15: 3) 7 parts by weight Negative charge control agent (dialkyl) Salicylic acid metal compound) 2 parts by weight

After sufficiently melting and kneading the above composition using an extruder, the cooled kneaded material was mechanically coarsely pulverized, and the coarsely pulverized material was impinged on a collision plate using a jet stream to finely pulverize the composition. The finely pulverized material was classified by an airflow classifier having a weight average diameter of 7.9 μm and SF-1 of 170.
Thus, nonmagnetic negatively-charged cyan toner particles obtained by the pulverization method with SF-2 of 157 were obtained. Obtained cyan toner particles 1
To 00 parts by weight, 2 parts by weight of titanium oxide fine particles having a primary particle size of about 20 nm (BET specific surface area: 100 m ² / g) hydrophobicized with isobutyltrimethoxysilane were externally added to obtain cyan toner O having excellent fluidity.

The other yellow toner, magenta toner and black toner use C.I. I. Pigment Yellow 17, C.I. I. Pigment Red 202 and grafted carbon black to obtain a yellow toner P, a magenta toner Q and a black toner R by a pulverization method in the same manner. The four color toners and the silicone resin-coated magnetic ferrite carrier having an average particle size of about 50 μm were mixed at a weight ratio of 5:95 to prepare two-component developers for magnetic brush development of each color. Table 1 shows the physical properties of the obtained toners of each color.

Toner Production Examples 19 to 22 (Non-magnetic toner
Production Example) After subjecting the toner particles of each color obtained in Toner Production Examples 15 to 18 to surface treatment by thermomechanical impact force (processing temperature of 60 ° C.), isobutyltrimethoxysilane and silicone oil were added to 100 parts by weight of the toner particles. Titanium oxide fine particles having a primary particle size of about 20 nm (BET specific surface area 10
0 m ² / g), 2 parts by weight of cyan toner S, yellow toner T, magenta toner U and black toner V were obtained. The above four color toners and a silicone resin-coated magnetic ferrite carrier having an average particle size of about 50 μm were respectively mixed into 5:
By mixing at a weight ratio of 95, two-component developers for magnetic brush development of each color were prepared. Table 1 shows the physical properties of the obtained toners of each color.

Toner Production Example 23 In the toner production example 1, dry silica having a primary particle diameter of 12 nm which had been subjected to hydrophobic treatment with silicone oil and hexamethyldisilazane (BET specific surface area after treatment: 120 m ² / g)
The same procedure was repeated except that 1.8 parts by weight and 0.5 part by weight of dry silica having a primary particle size of 40 nm treated with hexamethyldisilazane (BET specific surface area of 40 m ² / g after treatment) were used.
Magnetic toner W was obtained. Table 1 shows the physical properties of the obtained magnetic toner W.

[0223]

[Table 1]

Photoreceptor Production Example 1 As a photoreceptor, an aluminum cylinder having a diameter of 62 mm was used as a base. Layers having the structure shown in FIG. 3 and those shown below were successively laminated by dip coating to prepare a photoconductor.

(1) Conductive coating layer: Mainly composed of powder of tin oxide and titanium oxide dispersed in phenol resin. The thickness was 15 μm.

(2) Undercoat layer: Mainly composed of modified nylon and copolymerized nylon. The thickness was 0.6 μm.

(3) Charge generation layer: mainly composed of an azo pigment having absorption in a long wavelength region dispersed in a butyral resin. The thickness was 0.6 μm.

(4) Charge transporting layer: mainly composed of a hole transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight 20,000 according to Oswald viscosity method) at a weight ratio of 8:10, and further comprising polytetrafluoroethylene. A powder (particle size: 0.2 μm), which was added at 10% by weight based on the total solid content, and uniformly dispersed was used. The film thickness was 25 μm, and the contact angle with water was 95 degrees.

The contact angle was measured using pure water, and the apparatus used was a contact angle meter CA-DS, Kyowa Interface Science Co., Ltd.

Photoreceptor Production Example 2 A photoreceptor was produced in the same manner as in Photoreceptor Production Example 1, except that polytetrafluoroethylene powder was not added. Contact angle to water is 74
Degree.

Photoreceptor Production Example 3 A photoreceptor was prepared in the same manner as in Photoreceptor Production Example 1 up to the charge generation layer. As the charge transport layer, a material obtained by dissolving a hole transporting triphenylamine compound in a polycarbonate resin at a weight ratio of 10:10 was used. The film thickness was 20 μm. Further, the same material as a protective layer is further provided thereon at 5:10.
30 wt% of the total solid content of polytetrafluoroethylene powder (particle diameter: 0.2 μm) was added to the composition dissolved at a weight ratio of Spray coated. The film thickness was 5 μm, and the contact angle with water was 102 degrees.

Example 1 A rubber roller (diameter: 12 mm, contact pressure: 50 g / cm) in which conductive carbon coated with nylon resin was dispersed was used as a primary charging roller, and a photosensitive member was produced as an electrostatic latent image carrier. and -600V a dark portion potential V _D by laser exposure using a third OPC photosensitive drum (600 dpi), to form a digital latent image was bright potential V _L and -100 V. The black developing unit having the configuration shown in FIG. 2 is used at the position of the developing unit 4-4 in FIG. 1, and has a layer thickness of about 7 μm and a JIS center line average roughness (R
a) A 2.2 μm resin layer was blasted on the surface to a diameter of 1
A developing sleeve formed on a 6 mm stainless steel cylinder was used.

• 100 parts by weight of phenolic resin • 90 parts by weight of graphite (particle size: about 7 μm) • 10 parts by weight of carbon black

Next, the OPC photosensitive drum and the developing device 4-4
A gap between the developing sleeve (between S and D) is 300 μm, a developing magnetic pole is 80 mT (800 gauss), and a urethane rubber blade having a thickness of 1.0 mm and a free length of 10 mm is used as a toner regulating member at 14.7 N / m (15 g / 15 m). cm). DC bias component Vd as developing bias
c = −450 V, superimposed AC bias component Vpp = 1
200 V, f = 2000 Hz was used.

A urethane rubber blade having a thickness of 2.0 mm and a free length of 8 mm was brought into contact with the cleaning blade of the OPC photosensitive drum at a linear pressure of 24.5 N / m (25 g / cm). Process speed is 94mm / sec,
The developing sleeve was rotated in the forward direction with the ratio Vt / V between the peripheral speed Vt of the developing sleeve and the peripheral speed V of the photosensitive member being 1.5. The magnetic toner A of Toner Production Example 1 was used as the black toner.

The magenta toner, cyan toner and yellow toner use two-component developers prepared by using toners S, T or U of toner production examples 19 to 21, respectively. 4-2, 4-3, and at 23 ° C. under the above-described image forming conditions by a magnetic brush developing method.
A toner image of each color toner was formed by a reversal development method under a 65% RH environment. Each color toner image is sequentially transferred from the OPC photosensitive drum 1 to the intermediate transfer member 5 which is in pressure contact with the OPC photosensitive member, and the four color toner images on the intermediate transfer member 5 are transferred so that +6 μA as a transfer current flows to the drum. A voltage is applied to the roller 7 to weigh 75 g / m ² of the transfer material (plain paper).
Was transferred to the intermediate transfer member while being pressed by the transfer roller 7, and then a four-color toner image on the transfer material was heat-fixed by the heat-press fixing means 11 to form a full-color image.

At this time, the transfer efficiency of each color toner from the OPC photosensitive drum 1 to the intermediate transfer member 5 is 95 to 98%.
Transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 95 to 98%.
As a whole, a high transfer efficiency of 90.3 to 96.0% was exhibited, and a good full-color image was obtained, in which the toner image was excellent in color mixing properties, there was no omission during transfer, and there was no scattering on the image.

In the present invention, the evaluation of splatter is splatter evaluation on fine thin lines related to the quality of a graphical image, and is splatter evaluation on a 100 μm-wide line that is more easily splattered.

[0239] The evaluation of the omission during the transfer was made by weighing 199 g / m ^2.
(Normal paper was weighed 199 g / m ² , and a good image was obtained).

The transferability was determined from the Macbeth density of a toner image on a solid black photoreceptor, a transfer toner image on an intermediate transfer member, and a transfer toner image on a transfer material, which were taped and peeled off with a Mylar tape and affixed to paper. The evaluation was made by subtracting the Macbeth density from the tape only.

Example 2 An image was formed in the same manner as in Example 1 except that the magnetic toner B of Toner Production Example 2 was used as the black toner, and the OPC photosensitive drum of Photoconductor Production Example 1 was used as the electrostatic latent image carrier. I did it.

At this time, the transfer efficiency of each color toner from the OPC photosensitive drum 1 to the intermediate transfer member 5 is 94 to 97%.
The transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 93 to 97%.
The overall transfer efficiency was as high as 87.4 to 94.1%, and a good image was obtained without any missing characters or lines during the transfer and without scattering on the image.

Comparative Example 1 Magnetic toner G (SF-
2 = 151), except that toners O, P, and Q were used as color toners, and an image was formed in the same manner as in Example 2. As a result, the transfer efficiency from the OPC photosensitive drum 1 to the intermediate transfer member 5 is 85 to 90%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 80 to 85%, for a total of 68%.
The use efficiency of the toner was low at ７６76.5%. Omission occurred during transfer of characters and lines.

Comparative Example 2 As a black toner, the magnetic toner I (SF
Example 2 except that the OPC photosensitive drum of Photoconductor Production Example 2 was used as the electrostatic latent image carrier.
Image formation was performed in the same manner as described above. As a result, the transfer efficiency from the OPC photosensitive drum to the intermediate transfer member is 82 to 86%, and the transfer efficiency from the intermediate transfer member to the transfer material is 78 to 82%.
The transfer efficiency was inferior to that of Example 1 at 64 to 70.5% in total, and the image was somewhat scattered with a lot of missing characters and lines during transfer.

Comparative Example 3 A magnetic toner J was used instead of the magnetic toner A as the black toner.
(Inorganic fine powder not externally added) was carried out in the same manner as in Example 1. As a result, each transfer efficiency is as low as less than 70%,
Overall, it was less than 50%. In addition, the image was thin and scattered, and the image was thin and had many missing characters and lines during transfer.

Examples 3 to 6 A 16 mm diameter stainless steel cylinder whose surface was blasted with a resin layer having a layer thickness of about 7 μm and a JIS center line average roughness (Ra) of 1.5 μm having the following structure was used as a developing sleeve for black magnetic toner. The developing sleeve formed above was used.

Phenol resin 100 parts by weight Graphite (particle size: about 3 μm) 45 parts by weight Carbon black 5 parts by weight

Using this developing sleeve, magnetic toners C, D, E or F of Toner Production Examples 3 to 6 as black toner, and a DC bias component Vdc = -5 as a developing bias.
00V, superimposed AC bias component Vpp = 1100
V, f = 2000 Hz, and image formation was performed in the same manner as in Example 1 except that the developing sleeve was rotated in the forward direction with the ratio Vt / V of the peripheral speed Vt of the developing sleeve to the peripheral speed of the photosensitive member being 2.0. As a result, with the magnetic toners C and D, a good image was obtained with good transfer efficiency as in Example 1, without missing characters or lines during transfer, and without scattering on the image. Further, the magnetic toners E and F have slightly lower densities, and the transfer efficiency is lower than that of Example 1.
Although slightly lower, there was no practical problem. As in Example 1, there was no dropout during transfer of characters and lines, and an image without scattering on the image was obtained.

Example 7 The magnetic toner H of Toner Production Example 8 was used as a black toner, and a DC bias component Vdc = -4 was used as a developing bias.
50 V, superimposed AC bias component Vpp = 1300
Image formation was performed in the same manner as in Example 1 except that V and f were set to 2000 Hz. As in Example 1, a good image was obtained with good transfer efficiency, no missing characters or lines during transfer, and no scattering on the image.

Example 8 An image was formed using the same apparatus and under the same conditions as in Example 2 except that two-component magnetic brush development was performed using the nonmagnetic black toner V of Toner Production Example 22 as the black toner. As a result, as in Example 2, a good image with good transfer efficiency, no missing characters or lines during transfer, and no scattering on the image was obtained.

Example 9 An image was formed using the same apparatus and under the same conditions as in Example 1 except that the toners K, L and M of Toner Production Examples 11 to 14 were used as color toners. As a result, as in Example 1, a good image with good transfer efficiency, no missing characters or lines during transfer, and no scattering on the image was obtained.

Comparative Example 4 A commercially available full-color copying machine without intermediate transfer member (CLC
-500), an image output test was performed using the four color toners used in Comparative Example 1. For transfer paper weighing 105 g / m ^2, the transfer paper is adsorbed on the surface of the transfer drum using an auxiliary means such as a gripper, and the toner is sequentially transferred onto the transfer paper four times, and the four-color toner image on the transfer paper is heated. After fixing with a pressure roller, a high-quality full-color image could be obtained. However, the weighing was 199 more than in Comparative Example 1.
The transfer paper of g / m ² causes a partial non-uniform transfer failure based on the formation unevenness of the transfer paper, causes the transfer paper to be poorly attracted to the transfer drum, and furthermore, the rear end of the transfer paper from the transfer drum. Insufficiency of adsorption caused transfer failure.

Comparative Example 5 As toners, toners O, P, and
An image was formed using the same apparatus and conditions as in Comparative Example 1, except that the development was performed using a developer prepared using Q or R.
As a result, as in Comparative Example 1, the total transfer efficiency was less than 85%, and the image was somewhat conspicuous in characters and lines.

Comparative Example 6 An image was formed using the same apparatus and conditions as in Comparative Example 5, except that a two-component developer for magnetic brush development prepared using the non-magnetic toner N of Toner Production Example 14 as a black toner was used. I went out. As a result, as in Comparative Example 1, the total transfer efficiency was less than 85%, and the image was somewhat conspicuous in characters and lines.

Example 10 The same procedure as in Example 1 was carried out except that the magnetic toner W of Toner Production Example 23 was used as the black toner. At this time, the transfer efficiency of each color from the OPC photosensitive drum 1 to the intermediate transfer member 5 is 95 to
98%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 94 to 97%, and 89.3 to 95.1 as a whole.
%, High transfer efficiency, no missing characters or lines during transfer, and good images without scattering on the image were obtained.

Production Example of Liquid Lubricant-Supported Magnetic Material A predetermined amount of a liquid lubricant was added to a Simpson mix muller (MPVU-2, manufactured by Matsumoto Casting Co., Ltd.) based on 100 parts by weight of magnetic iron oxide (average particle size: 0.22 μm). And at room temperature for 30
After operating for a minute, the material was further loosened by a hammer mill to obtain a magnetic material (a) carrying a liquid lubricant.
Similarly, various liquid lubricants were carried on the magnetic material. Table 2 shows the physical property values of the magnetic materials (a) to (f) supporting the obtained liquid lubricant.

[0257]

[Table 2]

Production Example of Liquid Lubricant- Supported Lubricating Fine Particles While stirring the carrier fine particles (silica) carrying the liquid lubricant in a Henschel mixer, a liquid lubricant diluted with n-hexane was dropped. After completion of the dropping, the pressure was reduced while stirring to remove n-hexane, and then the mixture was pulverized by a hammer mill to obtain lubricating fine particles (a) carrying a liquid lubricant. Similarly, various liquid lubricants were carried on various carrier fine particles. Lubricated particles (a) supporting the obtained liquid lubricant
Table 3 shows the physical property values of (d).

[0259]

[Table 3]

Toner Production Example 24 100 parts by weight of magnetic substance (a) Styrene-butyl acrylate-butyl maleate half ester copolymer (low molecular weight side peak: about 5000, glass transition point Tg: 58 ° C.) 100 Parts by weight-Negative charge control agent (iron complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is coarsely pulverized with a hammer mill, the coarsely pulverized material is finely pulverized with a jet mill, and the obtained finely pulverized material is multi-divided using the Coanda effect The toner was strictly classified by a classifier to obtain magnetic toner particles. The magnetic toner particles are subjected to a surface treatment by a thermomechanical impact force (processing temperature of 60 ° C.), and 100 parts by weight of the obtained magnetic toner particles are treated with dry silica having a primary particle diameter of 12 nm (hydrophobized with hexamethyldisilazane). 1.8 parts by weight of BET specific surface area 160 m ² / g) and spherical silica (B
ET surface area 20 m ² / g, primary particle size 0.1 μm) 0.5
Parts by weight with a mixer to obtain Magnetic Toner 1.

The resulting magnetic toner 1 had a weight average particle size of 6.5 μm, a number average particle size of 5.3 μm,
SF-1 is 142, SF-2 is 126, B
The ET specific surface area was 5.3 m ² / cm ³ . The BET specific surface area of the magnetic toner particles was 1.7 m ² / cm ³ . Table 4 shows the physical properties of the magnetic toner 1 thus obtained.

Toner Production Example 25 In the toner production example 24, a magnetic substance (b) was used in place of the magnetic substance (a), and a dry powder having a primary particle diameter of 12 nm which had been hydrophobized with hexamethyldisilazane as inorganic fine powder. Magnetic toner 2 was obtained in the same manner as in Toner Production Example 24 except that 1.3 parts by weight of silica (BET specific surface area: 160 m ² / g) was used. Table 4 shows the physical properties of the obtained magnetic toner 2.
Shown in

Toner Production Example 26 90 parts by weight of magnetic substance (c) 100 parts by weight of styrene-butyl acrylate-butyl maleate half ester copolymer (low molecular weight side peak: about 10,000, glass transition point Tg: 62 ° C.) Parts-Negative charge control agent (iron complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

The above materials were used, the treatment temperature of the magnetic toner particles by thermomechanical shock was 64 ° C., and dry silica having a primary particle diameter of 8 nm hydrophobized with hexamethyldisilazane as inorganic fine powder (treated Magnetic toner 3 was obtained in the same manner as in Toner Production Example 24, except that the following BET specific surface area (180 m ² / g) was used in an amount of 1.8 parts by weight. Table 4 shows the physical properties of the magnetic toner 3 thus obtained.

Toner Production Example 27 A magnetic toner 4 was obtained in the same manner as in Toner Production Example 24 except that each of the magnetic substances (a) was replaced with the magnetic substance (d). Table 4 shows the physical properties of Magnetic Toner 4.

Toner Production Example 28 110 parts by weight of magnetic substance (a) 100 parts by weight of polyester resin (low molecular weight peak: about 7000, glass transition point Tg: 62 ° C.) 100 parts by weight of negative charge control agent (chromium of monoazo dye) Complex) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

A magnetic toner 5 was obtained in the same manner as in Toner Production Example 24, except that the above-mentioned materials were used and the processing temperature of the toner particles due to thermomechanical shock was set at 64 ° C.
Table 4 shows the physical properties of the magnetic toner 5 thus obtained.

Toner Production Example 29 100 parts by weight of polyester resin (low molecular weight side peak: about 6000, glass transition point Tg: 55 ° C.) 7 parts by weight of colorant (carbon black) 4 parts by weight of lubricating particles (a) Negative charge control agent (metal dialkylsalicylate) 2 parts by weight

After sufficiently kneading and kneading the above composition using an extruder, the cooled kneaded material is mechanically coarsely pulverized, and the coarsely pulverized material is finely pulverized by colliding with a collision plate using a jet stream, and further using the coander effect. The finely pulverized product was classified by an airflow classifier to obtain black toner particles. After the toner particles were subjected to a surface treatment by a thermomechanical impact force (processing temperature: 60 ° C.), titanium oxide fine particles having a primary particle diameter of about 20 nm (BET specific surface area: 130 m 2) treated hydrophobically with isobutyltrimethoxysilane were applied to 100 parts by weight of the toner particles. ² / g) of 2 parts by weight,
A nonmagnetic black toner 6 having excellent fluidity was obtained. The two-component developer was prepared by mixing the toner 6 and a silicone resin-coated magnetic ferrite carrier having an average particle size of about 50 μm at a weight ratio of 5:95. Table 4 shows the physical properties of Toner 6 thus obtained.

Toner Production Examples 30 to 32 In the toner production example 29, the lubricating particles (b), (c) or (d) are used instead of the lubricating particles (a), and the surface treatment conditions by thermomechanical impact force are changed. Other than toner production example 2
In the same manner as in No. 9, Toners 7, 8, and 9 were obtained. Table 4 shows the physical properties of Toners 7, 8, and 9 obtained.

Toner Production Example 33 100 parts by weight of polyester resin (low molecular weight peak: about 6000, glass transition point Tg: 55 ° C.) 7 parts by weight of cyan colorant (CI pigment blue 15: 3) Particles (a) 4 parts by weight-Negative charge control agent (metal dialkylsalicylate) 2 parts by weight

After sufficiently kneading and kneading the above composition with an extruder, the cooled kneaded material is mechanically coarsely pulverized, and the coarsely pulverized material is finely pulverized by colliding with a collision plate using a jet stream, and further using the coander effect. The finely pulverized material was classified by an airflow classifier to obtain cyan toner particles. Subsequently, the cyan toner particles were subjected to a surface treatment by a thermomechanical impact force (processing temperature: 60 ° C.), and 100 parts by weight of the obtained cyan toner particles were subjected to a hydrophobic treatment to obtain titanium oxide fine particles having a primary particle diameter of about 20 nm (BET specific surface area). 100 m ² / g) was added by 2 parts by weight to obtain a cyan toner 10 having excellent fluidity.

Toner Production Example 34 In toner production example 33, C.I. I. Pigment Blue 15: 3 instead of yellow colorant (C.I.
I. Pigment Yellow 17) and lubricating particles (a)
In the same manner as in Toner Production Example 33 except that lubricating particles (b) were used in place of the above, yellow toner 11 was obtained.

Toner Production Examples 35 and 36 In the toner production examples 33 and 33, the colorant and the lubricating particles were each replaced by a magenta colorant (CI pigmentlet 20).
2) and magenta toner 12 as lubricating particles (c)
In the toner production example 33, a black toner 13 was obtained by using the colorant and the lubricating particles as graft carbon black and the lubricating particles (d), respectively.

Toner Production Example 37 (Comparative Example) A magnetic toner 14 having an SF-2 of 152 was obtained in the same manner as in the toner production example 24 except that the surface treatment was not performed by the thermomechanical impact force. Was. Table 4 shows the physical properties of the obtained magnetic toner 14.

Toner Production Example 38 (Comparative Example) A magnetic toner 15 was obtained in the same manner as in Toner Production Example 24 except that no inorganic fine powder was added to the toner particles. Table 4 shows the physical properties of the obtained magnetic toner 15.

Toner Production Example 39 (Comparative Example) In the toner production example 29, 4 parts by weight of the lubricating particles (e) were used instead of the lubricating particles (a), and the surface treatment was not performed by thermomechanical impact. In the same manner as in Toner Production Example 29, a toner 16 having SF-2 of 158 was obtained. The two-component developer was prepared by mixing the above toner and a resin-coated ferrite carrier having an average particle size of about 50 μm at a weight ratio of 5:95, respectively. Table 4 shows the physical properties of Toner 16 thus obtained.

Toner Comparative Production Examples 40 to 43 (Comparative Examples) 100 parts by weight of polyester resin (low molecular weight side peak: about 6000, glass transition point Tg: 55 ° C.) Cyan colorant (CI Pigment Blue 15: 3) 7 parts by weight-Lubricating particles (e) 4 parts by weight-Negative charge control agent (metal dialkylsalicylate compound) 2 parts by weight

After sufficiently melting and kneading the above composition using an extruder, the cooled kneaded material is mechanically coarsely pulverized, and the coarsely pulverized material is finely pulverized by colliding with a collision plate using a jet stream to further utilize the Coanda effect. The finely pulverized material was classified by an airflow classifier having a weight average diameter of 7.9 μm and SF-1 of 170.
Thus, cyan toner particles obtained by the pulverization method with SF-2 of 157 were obtained. A primary particle diameter of about 20 parts by weight of 100 parts by weight of the obtained cyan toner particles was hydrophobized with isobutyltrimethoxysilane.
nm titanium oxide fine particles (BET specific surface area 130 m ² /
g) was added by 2 parts by weight to obtain cyan toner 17 having SF-2 of 159.

For the yellow toner, magenta toner and black toner, C.I. I. Pigment Yellow 17,
C. I. Pigment Red 202 and grafted carbon black, and a yellow toner 18, a magenta toner 19 and a black toner 20 were obtained in the same manner by a pulverization method. The above four color toners and a silicone resin-coated magnetic ferrite carrier having an average particle size of about 50 μm were mixed in 5:
By mixing at a weight ratio of 95, a two-component developer was prepared.

Toner Production Example 44 In Toner Production Example 24, dry silica having a primary particle size of 12 nm (BET specific surface area after treatment: 160 m ² / g) was prepared by hydrophobizing inorganic fine powder with hexamethyldisilazane.
Same as Production Example 24 except that 8 parts by weight and 0.5 parts by weight of dry silica having a primary particle diameter of 40 nm hydrophobized with hexamethyldisilazane (BET specific surface area after treatment of 40 m ² / g) are used. Thus, a magnetic toner 21 was obtained.

Table 4 shows the physical properties of the obtained toner.

[0284]

[Table 4]

Example 11 A rubber roller (diameter: 12 mm, contact pressure: 50 g / cm) in which conductive carbon coated with a nylon resin was dispersed was used as a primary charging roller, and a photosensitive member was produced as an electrostatic latent image carrier. laser exposure using an OPC photosensitive drum 3 of 3 (600 dpi) by dark portion potential V _D = -600 V, to form a digital latent image of light-area potential V _L = -100V. The black developing device having the configuration shown in FIG. 2 is used at the position of the developing device 4-4 shown in FIG. 1, and has a layer thickness of about 7 μm and a JIS center line average roughness (Ra) of the following configuration as a black toner carrier. A developing sleeve in which a 2.2 μm resin layer was formed on a 16 mm diameter stainless steel cylinder whose surface was blasted was used.

• 100 parts by weight of phenolic resin • 90 parts by weight of graphite (particle size: about 7 μm) • 10 parts by weight of carbon black

Next, the OPC photosensitive drum and the developing device 4-4
A gap between the developing sleeve (between S and D) is 300 μm, a developing magnetic pole is 80 mT (800 gauss), and a urethane rubber blade having a thickness of 1.0 mm and a free length of 10 mm is used as a toner regulating member at 14.7 N / m (15 g / 15 m). cm). DC bias component Vd as developing bias
c = −450 V, superimposed AC bias component Vpp = 1
200 V, f = 2000 Hz was used.

A urethane rubber blade having a thickness of 2.0 mm and a free length of 8 mm was brought into contact with the OPC photosensitive drum at a linear pressure of 24.5 N / m (25 g / cm) as a cleaning blade. Process speed is 94mm / sec,
The developing sleeve was rotated in the forward direction with the ratio Vt / V between the peripheral speed Vt of the developing sleeve and the peripheral speed V of the photosensitive member being 1.5. The magnetic toner 1 of Toner Production Example 24 was used as the black toner.

The magenta toner, cyan toner and yellow toner are toners 10 and 1 of toner production examples 33 to 35.
1 and 12 were used, and FIG.
23 ° C., 65% under the above-described image forming conditions by a magnetic brush developing method.
Under the RH environment, a toner image of each color toner was formed by a reversal developing method. Each color toner image is sequentially transferred from the photoconductor 1 to an intermediate transfer body 5
And transfer the toner images of four colors on the intermediate transfer member 5 to a transfer material (plain paper) with a weighing of 75 g / m ² by applying a voltage to a transfer roller so that +6 μA as a transfer current flows to the drum. Then, the four-color toner image on the transfer material was heat-fixed by a heat-pressure fixing unit.

At this time, the transfer efficiency of each color toner from the photosensitive member 1 to the intermediate transfer member 5 is 95 to 98%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 95 to 98%. Also, a high transfer efficiency as high as 90 to 96%, excellent color mixing, no omission during transfer, and a good image without scattering on the image were obtained.

Example 12 Toner 2 of Toner Production Example 25 was used as a black toner.
An image was formed in the same manner as in Example 11 except that the OPC drum of Photoconductor Production Example 1 was used as the electrostatic latent image carrier.

At this time, the transfer efficiency of each color toner from the OPC photosensitive drum 1 to the intermediate transfer member 5 is 95 to 98%.
Transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 95 to 98%.
As a result, a high transfer efficiency of 90 to 96% was obtained as a whole, and a good image was obtained without any missing characters or lines during the transfer and without scattering on the image.

Comparative Example 7 As a black toner, the toner 14 (SF
-2 = 152) as the color toners.
Image formation was performed in the same manner as in Example 12 except that No. 19 was used. As a result, the transfer efficiency from the photoconductor 1 to the intermediate transfer member 5 is 85 to 91%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 80 to 86%, for a total of 68 to 7%.
The efficiency of toner use was low at 8%. Further, the image was somewhat conspicuous in missing characters and lines during transfer.

Comparative Example 8 Magnetic toner 1 was used instead of magnetic toner 1 as a black toner.
Comparative Example 7 was carried out except that No. 5 (without external addition of inorganic fine powder) was used. As a result, each transfer efficiency was as low as less than 70%, and was less than 50% in total. In addition, the image was thin and scattered, and the image was thin and had many missing characters and lines during transfer.

Examples 13 to 16 As a magnetic toner carrier, the layer thickness was about 7 μm,
A developing sleeve was prepared in which a resin layer having an IS center line average roughness (Ra) of 1.5 μm was formed on a stainless steel cylinder having a diameter of 16 mm and a blasted surface.

• 100 parts by weight of phenolic resin • 45 parts by weight of graphite (particle size: about 3 μm) • 5 parts by weight of carbon black

Using this developing sleeve and the magnetic toners 3 and 4 of Toner Production Examples 26 and 27 as the black toner,
DC bias component Vdc = -500 as a developing bias
V, superimposed AC bias component Vpp = 1100V, f
= 2000 Hz, and the image was formed in the same manner as in Example 11, except that the developing sleeve was rotated in the forward direction with the ratio Vt / V of the peripheral speed Vt of the developing sleeve to the peripheral speed of the photosensitive member being 2.0. As a result, with the magnetic toners 3 and 4, good images were obtained with good transfer efficiency as in Example 11, without missing characters or lines during transfer, and without scattering on the images.

Example 17 The magnetic toner 5 of Toner Production Example 28 was used as the black toner, and the DC bias component Vdc =-
450 V, superimposed AC bias component Vpp = 1300
An image is formed in the same manner as in the eleventh embodiment except that V and f are set to 2000 Hz. Similar to the eleventh embodiment, the transfer efficiency is good, there is no omission during transfer of characters and lines, and there is no scattering on the image. Image was obtained.

Example 18 Example 12 was repeated except that the two-component magnetic brush development was performed using the black toner 13 of Toner Production Example 36 as the black toner.
Image formation was performed in the same manner as described above. As a result, Example 12
In the same manner as in the above, a good image having good transfer efficiency, no missing characters or lines during transfer, and no scattering on the image was obtained.

Examples 19 to 22 Toners 6 of Production Examples 29 to 32 as black toners
Image formation was performed in the same manner as in Example 18 except that 7, 8, and 9 were used. As a result, as in Example 18, a good image with good transfer efficiency, no missing characters or lines during transfer, and no scattering on the image was obtained. Although the transfer efficiency of the toner 9 was slightly low, a good image almost similar to that of the toners 6, 7, and 8 was obtained without any problem in practical use.

Comparative Example 9 Toners 17 and 1 of Toner Production Examples 40 to 43 as toners
Image formation was carried out using the same apparatus and conditions as in Comparative Example 7, except that the developer was prepared using 8, 19, and 20. As a result, the total transfer efficiency was 85 as in Comparative Example 7.
%, And the image was somewhat conspicuous in characters and lines.

Comparative Example 10 An image was formed using the same apparatus and under the same conditions as in Comparative Example 9 except that two-component development was performed using a developer prepared by using toner 16 of Toner Production Example 39 as the toner. . As a result, as in Comparative Example 7, the total transfer efficiency was less than 85%, and the image was somewhat conspicuous in characters and lines.

Example 23 An image was formed in the same manner as in Example 11, except that the toner 21 of Toner Production Example 44 was used as the toner. At this time, the transfer efficiency of each color toner from the photoconductor 3 to the intermediate transfer member 5 is 95 to 98%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is as high as 94 to 97%. A good image was obtained without any omission during transfer of characters and lines and no scattering on the image.

Toner Production Example 45 450 parts by weight of a 0.1 M Na ₃ PO ₄ aqueous solution were charged into 710 parts by weight of ion-exchanged water, and heated to 60 ° C., followed by TK
1200 using a homo homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 0 rpm. 68 parts by weight of a 1.0 M CaCl ₂ aqueous solution was gradually added thereto to obtain an aqueous medium containing fine particles of Ca ₃ (PO ₄ ) ₂ .

165 parts by weight of styrene monomer 35 parts by weight of n-butyl acrylate 15 parts by weight of magenta colorant (CI Pigment Red 202) 3 parts by weight of negative charge control agent (metallic dialkylsalicylate compound) 3 parts by weight Resin (saturated polyether resin) 10 parts by weight Release agent [ester wax (melting point 70 ° C)] 50 parts by weight

The above-mentioned material was heated to 60 ° C., and 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
And uniformly dissolved and dispersed. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 parts by weight were dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 10,000 rpm for 10 minutes using a TK homomixer at 60 ° C. in an N ₂ atmosphere. Granulated. Thereafter, the temperature was raised to 80 ° C. while stirring with a paddle stirring blade, and the reaction was performed for 10 hours. After completion of the polymerization reaction, the remaining monomer is distilled off under reduced pressure, and after cooling,
After adding hydrochloric acid to dissolve the calcium phosphate, the mixture was filtered, washed with water, and dried to obtain nonmagnetic negatively-charged magenta toner particles having a weight average particle size of 5.8 μm and a sharp particle size distribution.

To 100 parts by weight of the obtained magenta toner particles, B treated with isobutyltrimethoxysilane was used.
A magenta toner 2 was prepared by externally adding 2.0 parts by weight of hydrophobic titanium oxide having a specific surface area of 100 m ² / g by the ET method.
2 was obtained. Table 5 shows the physical properties of the obtained toner. To 7 parts by weight of this toner, 93 parts by weight of a magnetic ferrite carrier coated with an acrylic resin were mixed, and a developer (A)
And

Toner Production Example 46 450 parts by weight of a 0.1 M Na ₃ PO ₄ aqueous solution was charged into 710 parts by weight of ion-exchanged water, and heated to 60 ° C.
1200 using a homo homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 0 rpm. 68 parts by weight of a 1.0 M CaCl ₂ aqueous solution was gradually added thereto to obtain an aqueous medium containing fine particles of Ca ₃ (PO ₄ ) ₂ .

• styrene monomer 165 parts by weight • n-butyl acrylate monomer 35 parts by weight • cyan colorant (CI Pigment Red 15: 3) 15 parts by weight • negative charge control agent (metal dialkylsalicylate compound) 3 parts by weight Parts: Polar resin (saturated polyether resin) 10 parts by weight Release agent [ester wax (melting point 70 ° C)] 50 parts by weight

The above-mentioned material was heated to 60 ° C., and 2,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
And uniformly dissolved and dispersed. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 parts by weight were dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 10,000 rpm with a TK homomixer at 60 ° C. in an N ₂ atmosphere for 10 minutes to obtain a polymerizable monomer composition. Granulated. Thereafter, the temperature was raised to 80 ° C. while stirring with a paddle stirring blade, and the reaction was performed for 10 hours. After completion of the polymerization reaction, the remaining monomer is distilled off under reduced pressure, and after cooling,
After adding hydrochloric acid to dissolve the calcium phosphate, the mixture was filtered, washed with water, and dried to obtain non-magnetic, negatively-charged cyan toner particles having a weight average particle size of 5.5 μm and a sharp particle size distribution.

To 100 parts by weight of the obtained cyan toner particles, BE treated with isobutyltrimethoxysilane was used.
2.0 parts by weight of hydrophobic titanium oxide having a specific surface area of 100 m ² / g by T method was externally added to obtain a cyan toner 23. Table 5 shows the physical properties of the obtained toner. To 7 parts by weight of this toner, 93 parts by weight of a ferrite carrier coated with an acrylic resin were mixed to prepare a developer (B).

Toner Production Example 47 To 710 parts by weight of ion-exchanged water, 450 parts by weight of a 0.1 M Na ₃ PO ₄ aqueous solution were added, and after heating to 60 ° C., TK
1200 using a homo homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 0 rpm. 68 parts by weight of a 1.0 M CaCl ₂ aqueous solution was gradually added thereto to obtain an aqueous medium containing fine particles of Ca ₃ (PO ₄ ) ₂ .

• Styrene monomer 165 parts by weight • n-butyl acrylate monomer 35 parts by weight • Colorant (CI Pigment Yellow 17) 15 parts by weight • Negative charge control agent (metal dialkyl salicylate compound) 3 parts by weight • Polarity Resin (saturated polyether resin) 10 parts by weight Release agent [ester wax (melting point 70 ° C)] 50 parts by weight

The above-mentioned material was heated to 60 ° C., and was subjected to 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
And uniformly dissolved and dispersed. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 parts by weight were dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 60 ° C. under a N ₂ atmosphere with a TK homomixer at 10,000 rpm for 10 minutes. Granulated. Thereafter, the temperature was raised to 80 ° C. while stirring with a paddle stirring blade, and the reaction was performed for 10 hours. After completion of the polymerization reaction, the remaining monomer is distilled off under reduced pressure, and after cooling,
After adding hydrochloric acid to dissolve the calcium phosphate, the mixture was filtered, washed with water, and dried to obtain non-magnetic negatively-charged yellow toner particles having a weight average particle diameter of 5.9 μm and a sharp particle size distribution.

To 100 parts by weight of the obtained yellow toner particles, B treated with isobutyltrimethoxysilane was used.
2.0 parts by weight of hydrophobic titanium oxide having a specific surface area of 100 m ² / g by the ET method was externally added, and a yellow toner 2 was prepared.
4 was obtained. Table 5 shows the physical properties of the obtained toner. To 7 parts by weight of this toner, 93 parts by weight of a magnetic ferrite carrier coated with an acrylic resin were mixed, and a developer (C) was added.
And

Toner Production Example 48 100 parts by weight of magnetic material (average particle size 0.22 μm) Styrene-butyl acrylate-butyl maleate half ester copolymer (lower molecular weight peak: molecular weight about 5000, glass transition point Tg : 58 ° C) 100 parts by weight ・ Negative charge control agent (iron complex of monoazo dye) 2 parts by weight ・ Release agent (low molecular weight polyolefin) 2 parts by weight

The above materials were mixed in a blender, and
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is coarsely pulverized with a hammer mill, the coarsely pulverized material is finely pulverized with a jet mill, and the obtained finely pulverized material is multi-divided using the Coanda effect The particles were strictly classified by a classifier to obtain black magnetic toner particles. The magnetic toner particles were subjected to a surface treatment by a thermomechanical impact force (processing temperature: 60 ° C.), and 100 parts by weight of the obtained magnetic toner particles were subjected to a hydrophobic treatment with silicone oil and hexamethyldisilazane to give a primary particle diameter of 12 nm. Dry silica (BET specific surface area after treatment: 120 m ² / g)
1.8 parts by weight and spherical silica (BET surface area 20 m ² /
g, primary particle size 0.1 μm) and mixed by a mixer to obtain a black toner 25. This is developer D
And

The weight average particle size of the obtained black toner was 6.
5 μm, the number average particle size is 5.3 μm, SF
-1 is 141, SF-2 is 125, BET
The specific surface area was 5.3 m ² / cm ³ . B of toner particles
The ET specific surface area was 1.0 m ² / cm ³ . Table 5 shows the physical properties of the obtained toner.

Toner Production Example 49 (Comparative Example) A black toner 26 was obtained in the same manner as in Toner Production Example 48 except that dry silica and spherical silica were not externally added.

Toner Production Example 50 (Comparative Example) 100 parts by weight of polyester resin (low molecular weight side peak: molecular weight 6000, glass transition point Tg: 55 ° C.) I. Pigment Blue 15:37 parts by weight ・ Dialkylsalicylic acid metal compound 2 parts by weight

After sufficiently melting and kneading the above composition using an extruder, the cooled kneaded product was mechanically coarsely pulverized, and the coarsely pulverized product was made to impinge on an impingement plate using a jet stream to be finely pulverized. The finely pulverized material was classified by an airflow classifier, and the weight average diameter was 5.8 μm and SF-1 was 16
5. Cyan toner particles obtained by a pulverization method with an SF-2 of 155 were obtained. To the obtained cyan toner particles, 2 parts by weight of titanium oxide fine particles having a primary particle size of about 20 nm (BET specific surface area: 100 m ² / g) hydrophobized with isobutyltrimethoxysilane are externally added to obtain cyan toner 27 having excellent fluidity. Obtained.

A two-component developer (E) was prepared by mixing the above toner and an acrylic resin-coated magnetic ferrite carrier having an average particle size of about 35 μm at a weight ratio of 7:93. Table 5 shows the physical properties of the obtained toner.

Toner Production Example 51 5 parts by weight of carbon black (average particle diameter 60 nm) Styrene-butyl acrylate-butyl maleate half ester copolymer (low molecular weight side peak: molecular weight about 5000, glass transition point Tg: 58 ° C) 100 parts by weight-Negative charge control agent (iron complex of monoazo dye) 2 parts by weight-Release agent (low molecular weight polyolefin) 2 parts by weight

The above materials were mixed in a blender, and
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is coarsely pulverized with a hammer mill, the coarsely pulverized material is finely pulverized with a jet mill, and the obtained finely pulverized material is multi-divided using the Coanda effect The toner was strictly classified by a classifier to obtain black toner particles. The toner particles are subjected to thermomechanical impact (processing temperature 6
(0 ° C.), and 2.0 parts by weight of the above-mentioned titanium oxide fine particles were added to 100 parts by weight of the obtained toner particles, and mixed with a mixer to obtain a black toner 28.

The weight average particle size of the obtained black toner was 5.
8 μm, SF-1 is 140, SF-2 is 1
30. Table 5 shows the physical properties of the obtained toner.

To 7 parts by weight of this toner, 93 parts by weight of a magnetic ferrite carrier coated with an acrylic resin were mixed to prepare a developer (F).

Toner Production Example 52 To 710 parts by weight of ion-exchanged water, 450 parts by weight of a 0.1 M Na ₃ PO ₄ aqueous solution were added, and after heating to 60 ° C., TK
1200 using a homo homomixer (manufactured by Tokushu Kika Kogyo)
Stirred to 0 rpm. 68 parts by weight of a 1.0 M CaCl ₂ aqueous solution was gradually added thereto to obtain an aqueous medium containing fine particles of Ca ₃ (PO ₄ ) ₂ . To this, 0.1 part by weight of sodium dodecylbenzenesulfonate was added and mixed.

• 165 parts by weight of styrene monomer • 35 parts by weight of n-butyl acrylate monomer • 15 parts by weight of colorant [carbon black (average particle size: 60 nm)] 3 parts by weight of negative charge control agent (metallic dialkylsalicylate compound) Polar resin (saturated polyether resin) 10 parts by weight-Release agent [ester wax (melting point 70 ° C)] 50 parts by weight

The above-mentioned material was heated to 60 ° C., and was subjected to 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
And uniformly dissolved and dispersed. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 parts by weight were dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 60 ° C. under a N ₂ atmosphere with a TK homomixer at 10,000 rpm for 10 minutes. Granulated. Thereafter, the temperature was raised to 80 ° C. while stirring with a paddle stirring blade, and the reaction was performed for 10 hours. After completion of the polymerization reaction, the remaining monomer is distilled off under reduced pressure, and after cooling,
After adding hydrochloric acid to dissolve the calcium phosphate, colored suspension particles having a weight average particle size of 1 μm were obtained. Then, the mixture is heated to 60 ° C., adjusted to pH 7, further heated to 90 ° C., kept at this temperature for 2 hours, filtered, washed with water and dried to obtain aggregated particles having a weight average particle diameter of 6.3 μm. To obtain non-magnetic negatively-charged black toner particles.

To 100 parts by weight of the obtained black toner particles, BET treated with isobutyltrimethoxysilane was used.
Black toner 29 was obtained by externally adding 2.0 parts by weight of hydrophobic titanium oxide having a specific surface area of 100 m ² / g by the method. To 7 parts by weight of this toner, 93 parts by weight of a 35 μm magnetic ferrite carrier coated with an acrylic resin were mixed to prepare a developer (G).

Toner Production Example 53 A black toner 30 was obtained in the same manner as in Toner Production Example 48 except that silica (BET specific surface area: 180 m ² / g) not subjected to hydrophobic treatment was used. This is the developer (H)
And

Toner Production Example 54 In the toner production example 46, alumina treated with isobutyltrimethoxysilane (BET specific surface area: 160 m ² /
g) except that g) is used.
And developer (I) was prepared in the same manner.

Toner Production Example 55 In the same manner as in Toner Production Example 46 except that the hydrophobic silica used in Toner Production Example 48 was used instead of Titanium Oxide, cyan toner 32 was obtained. Similarly, a developer (J) was prepared.

Toner Production Examples 56, 57 and 58 Toner Production Examples 45, 46 and 47 were prepared in the same manner as in Toner Production Examples 45, 46 and 47, except that the polymerization was carried out at 80 ° C., and then the reaction was carried out in an autoclave at 120 ° C. for 5 hours. In the same manner, a magenta developer (K), a cyan developer (L), and a yellow developer (M) were obtained.

Toner Production Example 59 A toner was prepared in the same manner as in Toner Production Example 45 except that carbon black was used as a coloring agent, and a black developer (N) was obtained in the same manner.

[0340]

[Table 5]

Example 24 A rubber roller (diameter: 12 mm, contact pressure: 50 g / cm) in which conductive carbon coated with nylon resin was dispersed was used as a primary charging roller, and the photosensitive member 3 was used as an electrostatic latent image carrier. Laser exposure using an OPC photosensitive drum (600
The dark portion potential V _D = −600 V and the bright portion potential _{VL according} to dpi).
= -100 V digital latent image was formed. The black developing device having the structure shown in FIG. 2 is used at the position of the developing device 4-4 shown in FIG. 1, and has a layer thickness of about 7 μm and a JIS center line average roughness of the following structure as a black magnetic toner carrier. Ra) A developing sleeve was prepared in which a 2.2 μm resin layer was formed on a 16 mm diameter stainless steel cylinder whose surface was blasted.

• 100 parts by weight of phenolic resin • 90 parts by weight of graphite (particle size: about 7 μm) • 10 parts by weight of carbon black

Next, the gap (between SD) between the OPC photosensitive drum and the developing sleeve is set to 300 μm and the developing magnetic pole 80
mT (800 gauss), thickness 1.
0mm, 10mm free length urethane rubber blade
The contact was performed at a linear pressure of 4.7 N / m (15 g / cm). DC bias component Vdc = -450 as a developing bias
V, superimposed AC bias component Vpp = 1200 V, f
= 2000 Hz was used.

A urethane rubber blade having a thickness of 2.0 mm and a free length of 8 mm as an OPC photosensitive drum cleaning blade was contacted with a linear pressure of 24.5 N / m (25 g / cm). The process speed was 94 mm / sec and the developing sleeve was rotated in the forward direction with the ratio Vt / V of the peripheral speed Vt of the developing sleeve to the peripheral speed V of the photosensitive member being 1.5. The developer (D) was used as the magnetic toner.

The magenta toner, cyan toner and yellow toner are the developers (A) to (toner production examples 45 to 47).
Using the two-component developer prepared in (C), FIG.
23 ° C., 65% under the above-described image forming conditions by a magnetic brush developing method.
In the RH environment, a toner image of each color toner was formed by a reversal developing method. The toner images of each color are sequentially transferred from the OPC photosensitive drum to the intermediate transfer member 5, and the four color toner images on the intermediate transfer member 5 are transferred to a transfer material (plain paper) weighing 75 g / m ² .
The four-color toner image on the transfer material was heat-fixed by a heat-pressure fixing unit.

At this time, the transfer efficiency of each color toner from the OPC photosensitive drum to the intermediate transfer member 5 is 95 to 98%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 95 to 98%. Also, a high transfer efficiency as high as 90.3 to 96.0% was obtained, and a good image was obtained with excellent color mixing properties, no omission during transfer, and no scattering on the image.

Comparative Example 11 As a cyan developer, a developer (E) and a magnetic toner G (S
F-2 = 151), except that the image was formed in the same manner as in Example 24. As a result, the transfer efficiency of the solid image was reduced. As a result, there is no practical problem at 200 dpi, but 4
At 00 dpi, the scattering was good, but the reproducibility of highlight was slightly reduced.

Then, the transfer current was increased to improve the transferability, but it was not possible to achieve both the solid transferability improvement and the scattering.

This is presumed to be because the SF-2 of the cyan toner was too large than the SF-2 of the black toner, so that appropriate transfer conditions could not be set, and the transferability was reduced in a state where scattering was suppressed.

Comparative Example 12 Image formation was performed in the same manner as in Example 24 except that toner 26 (without adding inorganic fine powder) was used instead of developer (D). Extremely low. The omission during the transfer was poor, and the highlight was rough.

Example 25 An image was formed in the same manner as in Example 24 except that the developing device for black was changed to a two-component developing device and the developer (F) was used. Good results were obtained with no omission during transfer, roughness of highlights, and scattering of transfer.

Example 26 In Example 24, the developing devices for magenta, cyan and yellow were modified so as to use a non-magnetic one-component developing system, and the developing conditions were changed so that the gap between the developer carrier and the OPC photosensitive drum was reduced by 30%.
0 μm, a DC electric field of 300 V as a developing electric field and an AC electric field of 2 kHz and 2 kDpp were superimposed and applied to perform image formation without using carriers.
As in No. 4, good results were obtained.

Example 27 Image formation was performed in the same manner as in Example 24 except that the black developer (G) was used. As a result, the solid toner transfer efficiency of the black toner was slightly lowered to 95%.

Example 28 Image formation was performed in the same manner as in Example 24 except that the black developer (H) was used. As a result, both the solid transfer efficiency and the hollow area were lower than those in Example 24.

Example 29 An image was formed in the same manner as in Example 24 except that the cyan developer (I) was used, and good results were obtained.

Example 30 Image formation was carried out in the same manner as in Example 24 except that the cyan developer (J) was used, and good results were obtained.

Example 31 An image was formed in the same manner as in Example 25 except that the developers (K) to (N) were used, and good results were obtained.

Table 6 shows the evaluation results of the above Examples and Comparative Examples.

[0359]

[Table 6]

[0360]

According to the present invention, there is provided an image forming method for transferring a toner image on an electrostatic latent image carrier to an intermediate transfer material to which a bias is applied, and transferring the toner image on the intermediate transfer material to the transfer material. It is possible to improve omission during transfer and transfer efficiency while maintaining high image density and latent image reproducibility, and it is possible to obtain a high-quality and sharp image.

The image forming method, the image forming apparatus and the toner kit of the present invention can form a multicolor image or a full-color image in which an original image is well reproduced on various transfer materials.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a full-color image forming electrophotographic apparatus suitably used in the present invention.

FIG. 2 is a schematic view showing an example of a black developing device for one-component magnetic development.

FIG. 3 is a schematic view illustrating an example of a configuration of a photoreceptor preferably used in the present invention.

FIG. 4 is a schematic diagram of a charge amount measuring device for measuring a charge amount of a toner.

FIG. 5 is a diagram showing a good image (a) without “transfer missing” and a bad image (b) having “transfer missing”.

FIG. 6 is a diagram illustrating a range of the present invention with respect to toner shape factors SF-1 and SF-2.

FIG. 7 is a schematic view showing an example of a full-color image forming electrophotographic apparatus suitably used in the present invention having a transfer belt as a transfer unit in a second transfer step.

FIG. 8 is a schematic view showing an example of a full-color image forming electrophotographic apparatus suitably used in the present invention having an endless belt as an intermediate transfer member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor (electrostatic latent image carrier) 2 Charging roller 3 Exposure 4 Four-color developing device (4-1, 4-2, 4-3, 4-4) 5 Intermediate transfer body 6 Transfer material 7 Transfer roller

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI G03G 9/087 G03G 9/08 101 15/01 381 (31) Priority claim number Japanese Patent Application No. 7-94160 (32) Priority date Heisei Heisei March 29, 1995 (March 29, 1995) (33) Countries claiming priority Japan (JP) (72) Inventor Yuki Nishio 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Satoshi Yoshida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Kenji Okado 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Toshiyuki Ukai 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-61-279864 (JP, A) JP-A-1-185654 (JP, A) JP-A-6-225097 ( JP, A) JP-A-6-324575 JP, A) JP-A-6-194864 (JP, A) JP-A-5-142849 (JP, A) JP-A-4-220656 (JP, A) JP-A-5-341666 (JP, A) JP JP-A-6-11977 (JP, A) JP-A-2-10387 (JP, A) JP-A-7-36207 (JP, A) JP-A-1-185565 (JP, A) JP-A-6-148941 (JP) JP-A-5-119524 (JP, A) JP-A-6-123998 (JP, A) JP-A-1-186964 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB G03G 9/09 G03G 9/08 G03G 15/01

Claims (98)

(57) [Claims] A developing step of developing an electrostatic latent image with a developer to form a toner image on an electrostatic latent image carrier; and transferring the toner image onto an intermediate transfer member to which a voltage is applied. An image forming method including at least a transfer step and a secondary transfer step of transferring a toner image on the intermediate transfer body onto the transfer material while pressing a transfer unit to which a voltage is applied against the transfer material; The toner has a toner, and the toner is a black toner having at least a black toner particle in which a colorant is dispersed in a binder resin and an inorganic fine powder, and the value of the shape factor SF-1 of the black toner is 110 <S
F-1 ≦ 180, and the value of the shape factor SF-2 is 110
<SF-2 ≦ 140, and the ratio B / A of the value B obtained by subtracting 100 from the value of SF-2 and the value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. An image forming method comprising: (2) The development of the electrostatic latent image by the developer
This is carried out by the developer carried on the carrier, and
DC and AC development between the carrier and the electrostatic latent image carrier
The method according to claim 1, wherein a bias is applied.
The image forming method as described in the above. 3. The developer has a toner selected from a black toner, a yellow toner, a magenta toner and a cyan toner, and has a specific surface area Sb (m ²⁾ per unit volume of the black toner measured by a BET method. / Cm ³ ) and the specific surface area St (m ² / cm ³ ) per unit volume calculated from the weight average particle diameter when the toner is assumed to be a true sphere, as follows: 3.0 ≦ Sb / St ≦ 7. 0 and an image forming method according to claim 1 or 2 satisfying Sb ≧ St × 1.5 + 1.5. 4. The black toner is a magnetic toner containing 30 to 200 parts by weight of a magnetic substance with respect to 100 parts by weight of a binder resin, and has a shape factor SF-1 of 120.
≦ SF-1 ≦ 160 and the value of SF-2 is 115
The image forming method according to any one of ≦ SF-2 ≦ 140 a is claims 1 to 3. 5. The black toner has a ratio B / A of 0.20.
The image forming method according to any one of claims 1 to 4 , wherein the number is from 0.90 to 0.90. 6. said black image forming method according to any one of claims 1 to 5 charge quantity per unit volume of the toner is 30~80C / m ^3. 7. inorganic fine powder titania, alumina, silica or an image forming method according to any one of claims 1 to 6 which is an inorganic fine powder selected from the group that consists of mixed oxide. 8. The image forming method according to any one of claims 1 to 7 inorganic fine powder has been hydrophobized. 9. The image forming method according to claim 8 , wherein the inorganic fine powder has been treated with at least silicone oil. 10. inorganic fine powder is a primary particle size of 30nm or less, the toner is according to any one of claims 1 to 9 further comprising a second fine powder exceeding an average particle size 30nm Image forming method. 11. The image forming method according to claim 10 , wherein the second fine powder is an inorganic fine powder. 12. The image forming method according to claim 10 , wherein the second fine powder is a resin fine powder. Fine powder of 13. said second image forming method according to any one of claims 10 to 12 which is substantially spherical. 14. The black toner particles have a specific surface area per volume of 1.2 to 2.5 m as measured by a BET method.
The image forming method according to any one of the ² / cm ³ in a claim 1 to 13. 15. The black toner particles have a particle size of 1 nm to 100 nm.
The image forming method according to any one of claims 1 to 14 , wherein a 60% pore radius in a cumulative pore area ratio curve of pores of nm is 3.5 nm or less. 16. The black toner has a low-molecular-weight peak in the molecular weight distribution measured by GPC of 3,000 to 3,000.
The image forming method according to any one of claims 1 to 15 in the range of 15,000. 17. An electrostatic latent image is developed with a developer having a yellow toner to form a yellow toner image on an electrostatic latent image carrier, and then the yellow toner image is transferred onto an intermediate transfer member; The latent image is developed with a developer having magenta toner to form a magenta toner image on the electrostatic latent image carrier, and then the magenta toner image is transferred onto an intermediate transfer member; the electrostatic latent image has cyan toner Developing with a developer to form a cyan toner image on the electrostatic latent image carrier, and then transferring the cyan toner image onto the intermediate transfer member; the electrostatic latent image is developed with a developer having a black toner to form a static image. Forming a black toner image on the latent image carrier, and then transferring the black toner image onto the intermediate transfer member; a yellow toner image, a magenta toner image on the intermediate transfer member,
The image forming method according to any one of claims 1 to 16 cyan toner image and black toner image is transferred to the transfer material. 18. The black toner has a SF-2 value of yellow toner, magenta toner and cyan toner.
The image forming method according to claim 17 , wherein the value is 5 or more larger than the value of. 19. The yellow toner has a SF-1 of 100.
To 170, and SF-2 is 100 to 139, the magenta toner is 100 to 170 SF-1 and the SF-2 is 100 to 139, and the cyan toner is 100 to 170 SF-1. Yes and SF-2
The image forming method according to claim 17 or 18 but in the range of 100 to 139. 20. The yellow toner has an SF-1 of 100.
To 160 and SF-2 is 100 to 130, the magenta toner is 100 to 160 SF-1 and SF-2 is 100 to 130, and the cyan toner is 100 to 160 SF-1. Yes and SF-2
The image forming method according to claim 17 or 18 but in the range of 100 to 130. 21. The yellow toner has a SF-1 of 100.
And SF-2 is 100 to 125, magenta toner is SF-1 100 to 150 and SF-2 is 100 to 125, and cyan toner is SF-1 100 to 150. Yes and SF-2
The image forming method according to claim 17 , wherein the number is from 100 to 125. 19 . 22. Black toner is magnetic toner, a yellow toner non-magnetic toner, the magenta toner is a non-magnetic toner, a cyan toner according to any one of claims 17 to 21, which is a non-magnetic toner Image forming method. 23. The black toner, the yellow toner, the magenta toner and the cyan toner are non-magnetic toners.
22. The image forming method according to any one of 17 to 21 . 24. The black toner has black toner particles formed by melt-kneading a mixture having at least a binder resin and a black colorant, cooling the melt, and pulverizing the cooled melt. The yellow toner has yellow toner particles generated by polymerizing fine particles of a polymerizable monomer composition containing at least a polymerizable monomer and a yellow colorant in an aqueous medium, the magenta toner includes Magenta toner particles produced by polymerizing fine particles of a polymerizable monomer composition containing at least a polymerizable monomer and a magenta colorant in an aqueous medium, and a cyan toner is a polymerizable monomer. And cyan toner particles generated by polymerizing fine particles of a polymerizable monomer composition containing at least a cyan colorant in an aqueous medium. Item 24. The image forming method according to any one of Items 17 to 23 . 25. latent electrostatic image bearing member, an image forming method according to any one of claims 1 to 24 the contact angle for water on the surface is 85 degrees or more. 26. latent electrostatic image forming method according to any one of claims 1 to 25 containing a substance having a fluorine atom on the surface layer of the image bearing member. 27. The image forming method according to claim 26 , wherein the substance having a fluorine atom is a fine powder of a compound or a resin having a fluorine atom. 28. The intermediate transfer body and the surface of the transfer means are formed of an elastic layer, and the volume resistivity of the intermediate transfer body is higher than the volume resistivity of the transfer means, and the intermediate transfer is performed. The surface hardness of the body has a range of 10 to 40 degrees as measured by JIS K-6301, and the hardness of the surface of the transfer means is larger than the hardness of the intermediate transfer body. It pressed allowed form a concave nip on the intermediate transfer body side, the image forming method according to any one of claims 1 to 27 allowed to transfer the toner image by applying a voltage on the transfer material to the transfer means. 29. The intermediate transfer member, the image forming method according to any one of claims 1 to 28 having a cylindrical drum for carrying a toner image. 30. The intermediate transfer member, the image forming method according to any one of claims 1 to 28 having an endless belt for carrying the toner image. 31. The intermediate transfer member has a cylindrical drum for carrying a toner image, and the transfer means has a transfer belt for transferring the toner image carried on the cylindrical drum to a transfer material. Item 30. The image forming method according to any one of Items 1 to 28 . 32. The intermediate transfer member has an endless belt for carrying a toner image, and the transfer means has a transfer roller for transferring the toner image carried on the endless belt to a transfer material. or image forming method according to any one of 28. 33. Black toner, image forming method according to any one of claims 1 to 32 containing a liquid lubricant. 34. The liquid lubricant, wherein the liquid lubricant is 20 to 9%.
The image forming method according to claim 33 , wherein the toner is contained in the toner in the form of lubricating carrier particles containing 0% by weight. 35. black toner is a magnetic toner, an image forming method according to claim 33 or 34 liquid lubricant is supported on the magnetic material contained in the magnetic toner. 36. A liquid lubricant having a viscosity at 25 ° C. of 1
The image forming method according to any one of claims 33 to 35 , wherein the amount is from 0 to 200,000 cSt. 37. An electrostatic latent image carrier, developing means having a developer for forming a toner image on the electrostatic latent image carrier, and for carrying a toner image transferred from the electrostatic latent image carrier. An intermediate transfer member having a bias applying means, and at least a transfer means provided to press the intermediate transfer member having a bias applying means for transferring the toner image on the intermediate transfer member to a transfer material. An image forming apparatus, wherein the developer has a toner, and the toner is a black toner having at least a black toner particle in which a colorant is dispersed in a binder resin and inorganic fine powder; When the value of the shape factor SF-1 is 110 <S
F-1 ≦ 180, and the value of the shape factor SF-2 is 110
<SF-2 ≦ 140, and the ratio B / A of the value B obtained by subtracting 100 from the value of SF-2 and the value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. An image forming apparatus comprising: 38. The developing means is a toner carrying a developer.
The toner carrier and the electrostatic latent image carrier.
DC and AC developing bias is applied between the
The image forming apparatus according to claim 37, wherein
Place. 39. Specific surface area per unit volume Sb (m ² / cm ³ ) of the black toner measured by a BET method
And a specific surface area St (m ² / c) per unit volume calculated from the weight average particle diameter when the black toner is assumed to be a true sphere.
m ³ ) satisfying the following condition: 3.0 ≦ Sb / St ≦ 7.0 and Sb ≧ St × 1.5 + 1.5.
39. The image forming apparatus according to 37 or 38 . 40. The black toner is a magnetic toner containing 30 to 200 parts by weight of a magnetic substance with respect to 100 parts by weight of a binder resin, and the magnetic toner has a shape factor SF-1 value of 12%.
0 ≦ SF−1 ≦ 160, and the value of SF-2 is 11
40. Any of claims 37 to 39, wherein 5 ≦ SF−2 ≦ 140.
An image forming apparatus according to any one of the preceding claims. 41. The black toner has a ratio B / A of 0.2.
The image forming apparatus according to any one of claims 37 to 40 , wherein the number is from 0 to 0.90. 42. A charge amount per unit volume of said black toner image forming apparatus according to any one of claims 37 to 41 is 30~80C / m ^3. 43. The inorganic fine powder is titania, alumina,
Silica or the image forming apparatus according to any one of claims 37 to 42 which is an inorganic fine powder selected from the group consisting of the mixed oxide. 44. The image forming apparatus according to any one of claims 37 to 43 inorganic fine powder has been hydrophobized. 45. The image forming apparatus according to claim 44 , wherein the inorganic fine powder has been treated with at least silicone oil. 46. inorganic fine powder is a primary particle size of 30nm or less, the toner is according to any one of claims 37 to 45 further has a second fine powder exceeding an average particle size 30nm Image forming device. 47. The image forming apparatus according to claim 46 , wherein the second fine powder is an inorganic fine powder. 48. The image forming apparatus according to claim 46 , wherein the second fine powder is a resin fine powder. Fine powder of 49. said second image forming apparatus according to any one of claims 46 to 48 which is substantially spherical. 50. The black toner particles have a specific surface area per volume of 1.2 to 2.5 m as measured by a BET method.
The image forming apparatus according to any one of ² / cm ³ in which claims 37 to 49. 51. The black toner particles have a particle size of 1 nm to 100
The image forming apparatus according to any one of claims 37 to 50 , wherein a 60% pore radius in a cumulative pore area ratio curve of pores of nm is 3.5 nm or less. 52. The black toner has a low molecular weight peak in the molecular weight distribution measured by GPC of 3,000 to 3,000.
The image forming apparatus according to any one of claims 37 to 51 in the range of 15,000. 53. The electrostatic latent image is developed with a developer having a yellow toner to form a yellow toner image on an electrostatic latent image carrier, and then the yellow toner image is transferred onto an intermediate transfer member; The latent image is developed with a developer having magenta toner to form a magenta toner image on the electrostatic latent image carrier, and then the magenta toner image is transferred onto an intermediate transfer member; the electrostatic latent image has cyan toner Developing with a developer to form a cyan toner image on the electrostatic latent image carrier, and then transferring the cyan toner image onto the intermediate transfer member; the electrostatic latent image is developed with a developer having a black toner to form a static image. Forming a black toner image on the latent image carrier, and then transferring the black toner image onto the intermediate transfer member; a yellow toner image, a magenta toner image on the intermediate transfer member,
53. The image forming apparatus according to claim 37, wherein the cyan toner image and the black toner image are transferred to a transfer material. 54. The black toner has a SF-2 value of yellow toner, magenta toner and cyan toner.
54. The image forming apparatus according to claim 53 , wherein the value is 5 or more than the value of. 55. The yellow toner has a SF-1 of 100.
To 170, and SF-2 is 100 to 139, the magenta toner is 100 to 170 SF-1 and the SF-2 is 100 to 139, and the cyan toner is 100 to 170 SF-1. Yes and SF-2
There the image forming apparatus according to claim 53 or 54 is 100 to 139. 56. The yellow toner has SF-1 of 100.
To 160 and SF-2 is 100 to 130, the magenta toner is 100 to 160 SF-1 and SF-2 is 100 to 130, and the cyan toner is 100 to 160 SF-1. Yes and SF-2
There the image forming apparatus according to claim 53 or 54 is 100 to 130. 57. The yellow toner has a SF-1 of 100.
And SF-2 is 100 to 125, magenta toner is SF-1 100 to 150 and SF-2 is 100 to 125, and cyan toner is SF-1 100 to 150. Yes and SF-2
There the image forming apparatus according to claim 53 or 54 is 100 to 125. 58. black toner is a magnetic toner, the yellow toner is non-magnetic toner, a magenta toner is non-magnetic toner, according to any one of claims 53 to 57 Cyan toners are nonmagnetic toners Image forming device. 59. The black toner, yellow toner, magenta toner and cyan toner are non-magnetic toners.
58. The image forming apparatus according to any one of 53 to 57 . 60. A black toner having black toner particles produced by melt-kneading a mixture having at least a binder resin and a black colorant, cooling the melt, and pulverizing the cooled melt. The yellow toner has yellow toner particles generated by polymerizing fine particles of a polymerizable monomer composition containing at least a polymerizable monomer and a yellow colorant in an aqueous medium, and the magenta toner includes Magenta toner particles produced by polymerizing fine particles of a polymerizable monomer composition containing at least a polymerizable monomer and a magenta colorant in an aqueous medium, and a cyan toner is a polymerizable monomer. And cyan toner particles generated by polymerizing fine particles of a polymerizable monomer composition containing at least a cyan colorant in an aqueous medium. Item 60. The image forming apparatus according to any one of Items 53 to 59 . 61. latent electrostatic image bearing member, an image forming apparatus according to any one of claims 37 to 60 contact angle for water of the surface is 85 degrees or more. 62. The image forming apparatus according to any one of claims 37 to 61 containing a substance having a fluorine atom on the surface layer of the latent electrostatic image bearing member. 63. The image forming apparatus according to claim 62 , wherein the substance having a fluorine atom is a fine powder of a compound or a resin having a fluorine atom. 64. The intermediate transfer body and the surface of the transfer means are formed of an elastic layer, and the volume resistivity of the intermediate transfer body is higher than the volume resistivity of the transfer means, and the intermediate transfer is performed. The surface hardness of the body has a range of 10 to 40 degrees as measured by JIS K-6301, and the hardness of the surface of the transfer means is larger than the hardness of the intermediate transfer body. pressed allowed form a concave nip on the intermediate transfer body side, the image forming apparatus according to any one of claims 37 to 63 allowed to transfer the toner image voltage applied to transfer material to the transfer means. 65. The intermediate transfer member, the image forming apparatus according to any one of claims 37 to 64 having a cylindrical drum for carrying a toner image. 66. Intermediate transfer member, the image forming apparatus according to any one of claims 37 to 64 having an endless belt for carrying the toner image. 67. The intermediate transfer member has a cylindrical drum for carrying a toner image, and the transfer means has a transfer belt for transferring the toner image carried on the cylindrical drum to a transfer material. Item 70. The image forming apparatus according to any one of Items 37 to 64 . 68. The intermediate transfer member has an endless belt for carrying the toner image, according to claim 37 having a transfer means transfer roller for transferring a toner image carried on the endless belt to the transfer material 65. The image forming apparatus according to any one of claims 64 . 69. A black toner, an image forming apparatus according to any one of claims 37 to 68 containing a liquid lubricant. 70. The liquid lubricant, wherein the liquid lubricant is 20 to 9%.
70. The image forming apparatus according to claim 69 , wherein the toner is contained in the toner in the form of lubricating carrier particles containing 0% by weight. 71. black toner is a magnetic toner, an image forming apparatus according to claim 69 or 70 liquid lubricant is supported on the magnetic material contained in the magnetic toner. 72. A liquid lubricant having a viscosity at 25 ° C. of 1
The image forming apparatus according to any one of claims 69 to 71 , wherein the image forming apparatus has a viscosity of 0 to 200,000 cSt. 73. A yellow toner having at least a yellow toner particle and an inorganic fine powder containing a yellow colorant and a binder resin, and a magenta toner particle and an inorganic fine powder containing at least a magenta colorant and a binder resin. Toner having at least one body, cyan toner particles having at least a cyan-based colorant and a binder resin, cyan toner having an inorganic fine powder, and black having at least carbon black or / and a magnetic material and a binder resin A toner kit having a black toner having toner particles and inorganic fine powder, wherein the black toner has a shape factor SF-2 value of 140 or less and is larger than a shape factor SF-2 of a yellow toner, a magenta toner, and a cyan toner. Characterized toner kit. 74. The black toner having a shape factor SF-2 of 1
74. The toner kit according to claim 73 , which is 15 to 140 . 75. The black toner is a magnetic toner,
The yellow toner, toner kit according to claim 73 or 74 magenta toner and cyan toner are non-magnetic toner. 76. A specific surface area Sb (m ² / cm ³ ) per unit volume of each color toner measured by a BET method;
The specific surface area St (m ² / cm ³ ) per unit volume calculated from the weight average particle diameter when each color toner is assumed to be a true sphere is the following condition: 3.0 ≦ Sb / St ≦ 7.0 and S
claim to satisfy b ≧ St × 1.5 + 1.5 73 to 7
5. The toner kit according to any one of items 5 . 77. The black toner is a magnetic toner containing 30 to 200 parts by weight of a magnetic substance with respect to 100 parts by weight of a binder resin, and has a shape factor SF-1 of 12
0 ≦ SF−1 ≦ 160, and the value of SF-2 is 11
Toner kit according to any one of 5 ≦ SF-2 ≦ 140 a is 73. to 76. 78. Each color toner has a ratio B / A value of 0.20.
The toner kit according to any one of claims 73 to 77 , wherein the number is from 0.90 to 0.90. 79. A toner kit according to any one of claims 73 to 78 charge amount per unit volume of the respective color toners are 30~80C / m ^3. 80. The inorganic fine powder comprising titania, alumina,
The toner kit according to any one of claims 73 to 79 , wherein the toner kit is an inorganic fine powder selected from the group consisting of silica and a composite oxide thereof. 81. inorganic fine powder according to any one of claims 73 to 80 has been hydrophobized toner kit. 82. The toner kit according to claim 81 , wherein said inorganic fine powder is at least treated with silicone oil. 83.] inorganic fine powder is a primary particle size of 30nm or less, the toner is according to any one of claims 73 to 82 further has a second fine powder exceeding an average particle size 30nm Toner kit. 84. The toner kit according to claim 83 , wherein said second fine powder is an inorganic fine powder. 85. The toner kit according to claim 83 , wherein said second fine powder is a resin fine powder. Fine powder according to claim 86] said second, toner kit according to any one of claims 83 to 85 which is substantially spherical. 87. The toner particles have a specific surface area per volume measured by the BET method of 1.2 to 2.5 m ² /
89. The toner kit according to any one of claims 73 to 86 , wherein the toner kit has a size of cm ³ . 88. The toner particles have a particle size of 1 nm to 100 nm.
The toner kit according to any one of claims 73 to 87 , wherein the 60% pore radius in the cumulative pore area ratio curve of the pores is 3.5 nm or less. 89. The toner has a low molecular weight peak in the molecular weight distribution measured by GPC of 3,000 to 15,
The toner kit according to any one of claims 73 to 88 , wherein the number is in the range of 000 to 000. 90. The black toner has a SF-2 value of yellow toner, magenta toner and cyan toner.
90. The toner kit according to any one of claims 73 to 89 , wherein the value is 5 or more larger than the value of. 91. The yellow toner has a SF-1 of 100.
To 170, and SF-2 is 100 to 139, the magenta toner is 100 to 170 SF-1 and the SF-2 is 100 to 139, and the cyan toner is 100 to 170 SF-1. Yes and SF-2
The toner kit according to any one of claims 73 to 90 , wherein n is 100 to 139. 92. The yellow toner has a SF-1 of 100.
To 160 and SF-2 is 100 to 130, the magenta toner is 100 to 160 SF-1 and SF-2 is 100 to 130, and the cyan toner is 100 to 160 SF-1. Yes and SF-2
The toner kit according to any one of claims 73 to 90 , wherein is is 100 to 130. 93. The yellow toner has SF-1 of 100.
And SF-2 is 100 to 125, magenta toner is SF-1 100 to 150 and SF-2 is 100 to 125, and cyan toner is SF-1 100 to 150. Yes and SF-2
The toner kit according to any one of claims 73 to 90 , wherein n is 100 to 125. 94. The black toner has black toner particles formed by melt-kneading a mixture having at least a binder resin and a black colorant, cooling the melt, and pulverizing the cooled melt. The yellow toner has yellow toner particles produced by polymerizing fine particles of a polymerizable monomer composition containing at least a polymerizable monomer and a yellow colorant in an aqueous medium, magenta toner is Magenta toner particles produced by polymerizing fine particles of a polymerizable monomer composition containing at least a polymerizable monomer and a magenta colorant in an aqueous medium, and a cyan toner is a polymerizable monomer. And cyan toner particles produced by polymerizing fine particles of a polymerizable monomer composition containing at least a cyan colorant in an aqueous medium. Item 94. The toner kit according to any one of Items 73 to 93 . 95.] black toner, toner kit according to any one of claims 73 to 94 containing a liquid lubricant. 96. The liquid lubricant comprises 20 to 9 liquid lubricants.
The toner kit according to claim 95 , wherein the toner kit is contained in the toner in the form of lubricating carrier particles containing 0% by weight. 97.] black toner is a magnetic toner, toner kit according to claim 95 or 96 liquid lubricant is supported on the magnetic material contained in the magnetic toner. 98. A liquid lubricant having a viscosity at 25 ° C. of 1
The toner kit according to any one of claims 95 to 97 , wherein the toner kit has a viscosity of 0 to 200,000 cSt.