JPH08272139A - Toner and image forming method - Google Patents

Abstract

PURPOSE: To provide a toner by which excellent toner image transfer efficiency is provided, a remaining toner after a transfer is reduced, and no toner fusion to a latent image carrying body or to a toner carrying body is generated. CONSTITUTION: In a toner provided with toner grain, in which a coloring agent is dispersed in a binding resin, and inorganic fine powder, a toner shape factor SF-1 measured by means of an image analysis device is 110<SF-1<=180, a value of SF-2 is 110<SF-2<=140, a ratio B/A of a value B found by subtracting 100 from the value of SF-2 and a value A found by subtracting 100 from the value of SF-1 is 1.0 or less, a relationship between a toner specific surface area Sb (m<2> /cm<3> ) measured by a BET method and a specific surface area St (m<2> /cm<3> ) found from a weight average diameter on the assumption that the toner is a right sphere satisfies such conditions as 3.0<=Sb/St<=7.0 and Sb>=St×1.5+1.5, while in the binding resin, molecular weight indicates one peak in an area of 3×10<3> -3×10<4> and another peak or a shoulder in an area of 1×10<5> -3×10<6> while an acid value is 5-30gKOH/g. F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner and an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method and the like. For more information,
The present invention, after forming a toner image on the electrostatic latent image carrier in advance,
The present invention relates to a toner used in a copying machine, a printer, a fax, and an image forming method for forming an image by transferring onto a transfer material.

[0002]

2. Description of the Related Art Conventionally, a large number of electrophotographic methods are known, but generally, a photoconductive substance is used and an electric latent image is formed on an image bearing member (photoreceptor) by various means. After forming the latent image, the latent image is developed with toner to form a visible image, and the toner image is transferred to a transfer material such as paper as necessary, and then the toner image is fixed on the transfer material by heat or pressure. To obtain a copy.

As a method for visualizing an electric latent image, a cascade developing method, a magnetic brush developing method, a pressure developing method and the like are known. Further, there is also used a method in which a magnetic toner is used and a rotating sleeve having a magnetic pole at the center is used to fly between the photosensitive member and the sleeve by an electric field.

Unlike the two-component system, the one-component developing system does not require carrier particles such as glass beads and iron powder, so that the developing device itself can be made compact and lightweight. Further, since the two-component developing system needs to keep the toner concentration in the carrier constant, a device for detecting the toner concentration and supplying a required amount of toner is required. Therefore, also in this case, the developing device becomes large and heavy. Such a device is not necessary in the one-component developing system, and it is preferable because it can be made small and light.

In addition, LED and LBP printers have become the mainstream of the market in recent years as the printer apparatus, and the direction of technology is higher resolution, that is, 400, 600, 800 dpi instead of 240, 300 dpi in the past. ing. Therefore, the developing system is also required to have higher definition. Further, the copiers are also becoming more sophisticated, and as a result, they are moving toward digitalization. In this direction, the method of forming an electrostatic charge image by a laser is mainly used, and therefore, it is also advancing toward high resolution, and here also, as in the case of a printer, a high resolution / high definition developing method is required. . For this reason, the particle size of the toner is being reduced, and it is disclosed in Japanese Patent Laid-Open Nos. 1-112253 and 1-1.
No. 91156, No. 2-214156, No. 2-284158, No. 3-181952.
Japanese Patent Application Laid-Open No. 4-162048 and Japanese Patent Application Laid-Open No. 4-162048 propose a toner having a specific particle size distribution and a small particle size.

The toner image formed on the photoconductor in the developing process is transferred to the transfer material in the transfer process, but the transfer residual toner remaining on the photoconductor is cleaned in the cleaning process.
Toner is stored in the waste toner container. For this cleaning process, blade cleaning, fur brush cleaning, roller cleaning, etc. have been conventionally used. From the viewpoint of the apparatus, the size of the apparatus is inevitably increased due to the provision of such a cleaning apparatus, which has been a bottleneck when aiming to make the apparatus compact. Further, from the viewpoint of ecology, a system with less waste toner is desired in terms of effective utilization of toner, and a toner with good transfer efficiency has been demanded.

Japanese Patent Application Laid-Open No. 61-279864 proposes toners having shape factors SF-1 and SF-2. However, there is no description regarding transfer in this publication, and as a result of carrying out Examples, transfer efficiency is low and further improvement is required.

Further, in JP-A-63-235953 and JP-A-2-85866, there is proposed a magnetic toner spherically shaped by a mechanical impact force. However, the transfer efficiency is still insufficient and further improvement is needed.

Further, in recent years, from the viewpoint of environmental protection, the primary charging and transfer processes using corona discharge, which have been conventionally used, are becoming mainstream, and the primary charging and transfer processes using a photoconductor contact member are becoming mainstream.

For example, JP-A-63-149669 and JP-A-2-123385 have been proposed. These are related to the contact charging method and the contact transfer method, but a conductive elastic roller is brought into contact with the electrostatic latent image carrier,
While electrostatically charging the electrostatic latent image carrier while applying a voltage to the conductive roller, another voltage was applied to the electrostatic latent image carrier after obtaining a toner image by exposure and development steps. While transferring the transfer material while pressing the conductive roller to transfer the toner image on the electrostatic latent image bearing member onto the transfer material, a transfer image is obtained through a fixing step.

However, in such a roller transfer system which does not use corona discharge, the transfer member is brought into contact with the photoconductor through the transfer member during the transfer, so that the toner image formed on the photoconductor is transferred to the transfer material. When the toner image is transferred to the toner image, the toner image is pressed into contact with the toner image, which causes a problem of partial transfer failure, which is so-called transfer void (see FIG. 5).

Further, as the toner diameter becomes smaller, the adhesion force of the toner particles to the latent image carrier (such as the image force and van der Waals force) becomes larger than the Coulomb force applied to the toner particles by the transfer. As a result, the transfer residual toner tends to increase.

Further, in the roller charging system, the physical and chemical action on the surface of the electrostatic latent image bearing member due to the discharge generated between the charging roller and the electrostatic latent image bearing member is larger than that in the corona charging system. In particular, in the combination with the organic photoconductor / blade cleaning, abrasion due to deterioration of the photoconductor surface is likely to occur, and there is a problem in life (direct charging /
The combination of the organic photoreceptor / one-component magnetic developing method / contact transfer / blade cleaning makes it easy to reduce the cost and size and weight of the image forming apparatus. This is the mainstream method for printers, facsimiles, etc. ).

Therefore, it has been required that the toner and the photoconductor used in such an image forming method have excellent releasability.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner and an image forming method which solve the above problems of the prior art.

That is, the object of the present invention is to provide excellent transferability,
An object of the present invention is to provide a toner and an image forming method in which the amount of residual toner after transfer is small and voids in transfer do not occur even in a roller transfer system, or these phenomena are suppressed.

Further, an object of the present invention is to provide a toner and an image forming material which are excellent in mold releasability and slipperiness, and which have a long life and a small photoconductor scraping ability even after a long period of time and after printing a large number of sheets. To provide a method.

It is a further object of the present invention to provide a toner and an image forming method in which abnormal charging or image defects due to contamination of a member which is pressed against the electrostatic latent image carrier does not occur, or these phenomena are suppressed. It is in.

A further object of the present invention is to provide a toner and an image forming method in which fusion of toner onto the surface of a latent image carrier does not occur or is unlikely to occur.

A further object of the present invention is to provide a toner and an image forming method in which the fusion of the toner onto the surface of the toner carrier does not occur or is unlikely to occur.

[0021]

The present invention is a toner having at least toner particles in which a colorant is dispersed in a binder resin and an inorganic fine powder, and the shape factor of the toner measured by an image analyzer. The value of SF-1 is 110 <SF-1
≦ 180, and the value of the shape factor SF-2 is 110 <SF.
−2 ≦ 140, and the ratio B / 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
The value of A is 1.0 or less, and the specific surface area Sb (m ² / c) of the toner per unit volume measured by the BET method.
m ³ ), and the specific surface area St (m ² / c) per unit volume calculated from the weight average particle diameter when the toner is assumed to be a true sphere.
m ³ ) satisfies the following condition 3.0 ≦ Sb / St ≦ 7.0 Sb ≧ St × 1.5 + 1.5, and the molecular weight of 3 × in the GPC chromatogram of the THF-soluble component of the binder resin. It has one peak in the region of 10 ^{3 to} 3 × 10 ⁴ and has a molecular weight of 1 × 10 ^{5 to} 3 × 1.
0 has ^six areas the peak or shoulder in the toner and the toner image using the toner to the electrostatic latent image bearing member acid value of the binder resin is characterized by a 5~30gKOH / g And a transfer step of transferring the toner image onto the transfer material while bringing a transfer member to which a voltage is applied into contact with a transfer material.

Preferably, the value of SF-1 is 120≤SF-
1 ≦ 160 and the value of SF-2 is 115 ≦ SF−
A toner with 2 ≦ 140 is used.

In the present invention, SF-indicating the shape factor
1 and SF-2 are, for example, Hitachi FE-SEM
(S-800) is used to randomly sample 100 toner images of 2 μm or more magnified 1000 times, and the image information is introduced into an image analysis device (Luzex III) manufactured by Nicolet Co., Ltd. through an interface. The value obtained by performing the analysis and calculating from the following equation is used as the shape factor SF-1, S
It is defined as F-2.

[0024]

[Equation 1]

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

The shape factor SF-1 indicates the degree of roundness of the toner particles, and the shape factor SF-2 indicates the degree of unevenness of the toner particles.

When the toner shape factor SF-1 is 110 or less, the toner spherical factor SF-2 is 110 or less, and the ratio B / A is more than 1.0, cleaning failure generally occurs. It is easy to do, and the toner shape factor S
When F-1 exceeds 180, the toner is separated from the sphere and approaches an irregular shape, the toner is easily crushed in the developing device, the particle size distribution is fluctuated, the charge amount distribution is apt to be broad, and background fog and reverse fog occur. Cheap. On the other hand, if SF-2 exceeds 140, the transfer efficiency of the toner image at the time of transfer from the electrostatic image carrier to the transfer material is deteriorated, and character or line image dropout occurs, which is not preferable. At this time, the toner manufactured by the pulverization method is preferably used.

The value of the ratio B / A indicates the slope of a straight line passing through the origin in FIG. 6, and this value is preferably 0.20.
In order to improve the transferability while maintaining the developability, it is preferable that the range is 0.95 (more preferably 0.35 to 0.85).
preferable.

Further, by having the inorganic fine powder on the surface of the toner particles, the transfer efficiency is improved and the voids in the transfer of characters and line images are 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 (St = 6 / calculated from the weight average particle diameter (D ₄ ) assuming that the toner is a true sphere. D ₄ ) is 3.0 ≦ Sb / St ≦ 7.0 and Sb ≧ St ×
It is preferably 1.5 + 1.5, and further, Sb is 3.2 to 6.8 m ² / cm ³ (more preferably 3.4 to
It is preferably 6.3 m ² / cm ³ ).

If the ratio is less than 3.0 times, the transfer efficiency is insufficient, and if it exceeds 7.0 times, the image density is lowered. It is considered that this is because the inorganic fine particles added to the toner particles behave effectively as a spacer between the toner particles and the toner image carrier.

The specific surface area of the toner within the above range is achieved by controlling the specific surface area of the toner particles, the specific surface area of the inorganic fine powder added to the toner particles, the addition amount and the addition mixing strength. If the addition and mixing strength is too high, the inorganic fine particles will be embedded in the toner particles and the transfer efficiency will not be improved sufficiently.

Furthermore, since the inorganic fine powder is effectively used, 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 the theoretical specific surface area per volume calculated from the weight average particle diameter assuming that the toner is a true sphere.
It is good 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. 1 nm to 100 nm of toner particles before adding inorganic particles
The 60% pore radius in the cumulative pore area ratio curve of the pores is preferably 3.5 nm or less. At this time, the BET specific surface area Sb of the toner and the BET specific surface area Sr of the toner particles
The value of the ratio Sb / Sr of is preferably in the range of 2-5.

These are those in which the inorganic fine powder behaves more effectively and the transfer efficiency is improved by reducing the pores in the toner particles which are larger than the primary particle diameter of the inorganic fine powder added to the toner particles. it is conceivable that.

The specific surface area was determined according to the BET method by using a specific surface area measuring apparatus Autosorb 1 (manufactured by Yuasa Ionics Co., Ltd.) to adsorb nitrogen gas on the surface of the sample, and calculating the specific surface area using the BET multipoint method. Further, the 60% pore radius was calculated from the integrated pore area ratio curve with respect to the desorption side pore radius. In Autosorb 1, the pore size distribution is calculated by Bar
rett, Joyner & Harenda (B.
J. H.). J. The H method is used.

The inventors of the present invention further examined the toner having the above-mentioned special form. When the continuous image forming test was conducted in a high temperature environment, the toner was fused to the surface of the latent image carrier. I found it easy to do.

As a mechanism for fusing the toner to the surface of the latent image bearing member, the inventors of the present invention have described "a shock during development, or
A member such as a cleaner / charging member which is in contact with the surface of the latent image carrier, and which is in contact with the surface of the latent image carrier such as a cleaner / charging member, with the toner lightly fused by pressing force from the member. At this point, it is considered that the toner rubs against the latent image carrier to generate frictional heat, and the heat partially melts the toner surface to grow into full-scale fusion.

The toner produced by the crushing method, which has been mainly used conventionally, has a shape with many irregularities, and a slight initial stage toner fusion material is scratched from the surface of the latent image carrier by the polishing force resulting from the irregularities. The toner of the present invention has a relatively low tendency to grow to a level at which fusion and fusing become a problem, but the toner of the present invention is
It has a “rounded” shape, and it is considered that fusion is likely to occur under severe conditions because the abrasiveness of the toner particles themselves is reduced.

Therefore, the inventors of the present invention have considered and considered to reduce the fusing of the toner to the latent image bearing member by reducing the frictional heat generated between the toner and the latent image bearing member. It has been found that the fusion of the toner to the latent image carrier can be suppressed by controlling the molecular weight distribution and the acid value of the binder resin of the toner within the above ranges.

In the GPC chromatogram of the THF-soluble component of the binder resin, the presence of a low molecular weight component due to the presence of one peak in the molecular weight range of 3 × 10 ^{3 to} 3 × 10 ⁴ prevents the latent image bearing member from being affected. Toner fusion can be suppressed.

It is considered that the reason is that the frictional resistance of the toner to the latent image carrier is reduced, the frictional heat generated is reduced, and the fusion does not grow.

When the molecular weight has a peak corresponding to a low molecular weight of less than 3 × 10 ³ , the durability of the toner against mechanical stress becomes insufficient. Further, when the molecular weight has a peak corresponding to a low molecular weight of 3 × 10 ⁴ or more, the effect of suppressing toner fusion cannot be obtained.

In the GPC chromatogram of the THF-soluble component of the binder resin, the molecular weight was 1 × 10 ^{5 to} 3 × 10 ^6.
By having a peak or shoulder in the region of,
It is possible to improve "durability against mechanical stress applied to the toner on the toner carrier", which is insufficient with only the low molecular weight component, and prevent fusion to the toner carrier.

If the molecular weight has a peak or shoulder for high molecular weight of less than 1 × 10 ⁵ , the effect of improving durability of the toner against mechanical stress cannot be obtained. Further, when the molecular weight has a peak or shoulder for high molecular weight of 3 × 10 ⁶ or more, it is not preferable because pulverization during toner production becomes difficult.

The proportion of the low molecular weight component of the binder resin (region less than 5 × 10 ⁴ in the GPC chromatogram) (W
L) and high molecular weight (5 in GPC chromatogram)
When the ratio of the ratio (WH) of the area (× 10 ⁴ or more) is WL: WH = 50: 50 to 90:10, the effect of suppressing toner fusion to the latent image carrier is further improved.

The reason for this is considered to be that by increasing the proportion of the low molecular weight component (having the toner fusion suppressing effect) in the entire binder resin, the toner fusion suppressing effect is further enhanced.

The molecular weight is measured by GPC (gel permeation chromatography). Concrete GP
As a method for measuring C, a sample obtained by previously extracting the toner with a Soxhlet extractor for 20 hours with a THF (tetrahydrofuran) solvent was used, and the column configuration was A-801, 802, 803, 804, 805, 80 manufactured by Showa Denko.
6,807 can be connected and the molecular weight distribution can be measured using the calibration curve of standard polystyrene resin.

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

The acid value of the binder resin is 3 to 30 (more preferably 5 to 25) gKOH / g,
Toner fusion can be further reduced.

The reason for this is that the surface tension of the toner surface during melting is high due to the polarity of the acid groups present in the binder resin, and even if the toner surface is in a molten state, it is difficult to fuse to the latent image carrier. I think that

If the acid value of the binder resin is less than 3, there is no effect of improving the toner fusion preventing ability.

If the acid value of the binder resin exceeds 30,
The chargeability of the toner is impaired, which is not preferable.

The acid value of the binder resin is the number of mg of potassium hydroxide necessary to neutralize the acid contained in 1 g of the sample.

The acid value of the binder resin is measured as follows. About 2 g of the ground sample is precisely weighed (W (g)).
Put the sample in a 200 ml Erlenmeyer flask, add 100 ml of a mixed solution of toluene / ethanol (2: 1), and dissolve for 5 hours. Add phenolphthalene solution as an indicator. 0.1 N KOH is also titrated with a burette using an alcohol solution. KO at this time
Let the amount of H solution be S (ml). Do a blank test,
At the same time, the amount of the KOH solution is B (ml).

The acid value is calculated by the following formula.

[0056]

[Equation 2]

In order to faithfully develop finer latent image dots for higher image quality, the toner particles have a weight average diameter of 4
The thickness is preferably 9 to 9 μm. Weight average diameter is 4μ
With toner particles of less than m, a large amount of toner remains after being transferred on the photoconductor due to a decrease in transfer efficiency, and moreover, it is likely to cause uneven image unevenness due to fog and transfer failure. Not preferable. Further, when the weight average diameter of the toner particles exceeds 9 μm, scattering of characters and line images is likely to occur.

For the average particle size and particle size distribution of the toner, a Coulter Counter TA-II type or a Coulter Multisizer (manufactured by Coulter) is used, and an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution and PC9.
801 personal computer (manufactured by NEC) is connected, and the electrolyte is 1% NaCl using primary sodium chloride.
Prepare an aqueous solution. For example, ISOTON R-II
(Manufactured by Coulter Scientific Japan) can be used. As the measuring method, the electrolytic aqueous solution 100 to 1 is used.
0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) as a dispersant is added to 50 ml,
Further, 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample was suspended was subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and number of toner particles having a size of 2 μm or more were measured using a 100 μm aperture as an aperture with the Coulter Counter TA-II type. The volume distribution and number distribution were calculated. Then, the volume-based weight average particle diameter (D ₄ ) obtained from the volume distribution and the number-based length average particle diameter (D ₁ ) obtained from the number distribution according to the present invention were obtained.

The charge amount per unit volume (two-component method) of the toner according to the present invention is 30 to 80 C / m ³ (more preferably 40 to 70 C / m ³ ). It is preferable for improving transfer efficiency in a transfer method using a member.

The method of measuring the charge amount (two-component tribo) of the toner according to the present invention by the two-component method is shown below (FIG. 4).

Using an EFV200 / 300 (manufactured by Powder Tech) as a carrier in an environment of 23 ° C. and 60% relative humidity, a mixture of 9.5 g of carrier and 0.5 g of toner was added to a polyethylene bottle having a capacity of 50 to 100 ml. Shake by hand 50 times. Next, 1.0 to 1.2 g of the mixture is put into a metal measuring container 22 having a 500-mesh screen 23 on the bottom, and a metal lid 24 is placed. At this time, the total mass of the measurement container 22 is weighed and set as W ₁ (g). Next, in the suction device (at least the portion in contact with the measurement container 22 is an insulator), suction is performed from the suction port 27 and the air flow rate control valve 26 is adjusted to adjust the pressure of the vacuum gauge 25 to 2450 Pa (25
0 mmAq). In this state, suction is performed for 1 minute to remove the toner by suction. The potential of the electrometer 29 at this time is V
(Volts). Here, 28 is a capacitor, and the capacitance is C (μF). Further, the mass of the entire measuring machine after suction is weighed and designated as W ₂ (g). Triboelectric charge amount of this toner (m
C / kg) is calculated by the following formula.

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

The type of the binder resin used in the present invention is, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene or the like, or a substitution product thereof; styrene-p-chlorostyrene copolymerization. Coal, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene- Acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile- Styrene-based copolymers such as indene copolymers Combined; polyvinyl chloride, phenol resin, natural modified phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin , Polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used. A crosslinked styrene resin is also a preferable binder resin.

Of these, styrene resins are most preferred. The styrene-based resin has particularly good chargeability in a high-humidity environment, and tends to have a higher image density after being left in a high-humidity environment than other resins.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Didecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof;
For example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate, and the like; and substituted compounds thereof; for example, vinyl chloride,
Vinyl esters such as vinyl acetate, vinyl benzoate, etc., ethylene-based olefins such as ethylene, propylene, butylene, etc .; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc .;
For example, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether and the like; and vinyl monomers such as are used alone or in combination. Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used, and examples thereof include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate and ethylene glycol. Dimethacrylate,
A carboxylic acid ester having two double bonds such as 1,3-butanediol dimethacrylate; a divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and a compound having three or more vinyl groups; Can be used alone or as a mixture.

Examples of the monomer for adjusting the acid value of the binder resin include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid and its α- or β-alkyl derivative, fumaric acid. , Maleic acid, unsaturated dicarboxylic acids such as citraconic acid and their monoester derivatives or maleic anhydride, etc., and a desired polymer can be obtained by copolymerizing such monomers alone or in combination with other monomers. Can be made. Among these, it is particularly preferable to use a monoester derivative of unsaturated dicarboxylic acid.

More specifically, for example, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate,
Monoesters of α, β-unsaturated dicarboxylic acids such as monophenyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monophenyl fumarate, etc .; monobutyl n-butenyl succinate, monomethyl n-octenyl succinate, Monoesters of alkenyl dicarboxylic acids such as monoethyl n-butenylmalonate, monomethyl n-dodecenyl glutarate, monobutyl n-butenyl adipate; phthalic acid monomethyl ester, phthalic acid monoethyl ester, phthalic acid monobutyl ester, etc. Aromatic dicarboxylic acid monoesters;

As a method for producing the binder resin according to the present invention, a solution blending method in which a high molecular weight polymer and a low molecular weight polymer are separately synthesized by a solution polymerization method, these are mixed in a solution state, and then a solvent is removed. Also, a dry blending method of melt-kneading with an extruder or the like, and a low molecular weight polymer obtained by a solution polymerization method or the like are dissolved in a monomer constituting a high molecular weight polymer, suspension polymerization is performed, and washing with water is performed. Examples thereof include a two-step polymerization method of obtaining a binder resin by drying. However, the dry blending method has problems in uniform dispersion and compatibility, and the two-step polymerization method has many advantages such as uniform dispersibility, but the low molecular weight polymer component is changed to the high molecular weight polymer component. It is difficult to increase the amount above, and in the presence of the low molecular weight polymer component, not only is it difficult to synthesize a high molecular weight polymer component having a large molecular weight, but also unnecessary low molecular weight polymer components are by-produced. The solution blending method is most suitable for application to the present invention because it has drawbacks such as the above.

As a method for synthesizing the low molecular weight component of the binder resin according to the present invention, a known method can be used. However, in the bulk polymerization method, although a low molecular weight polymer can be obtained by polymerizing at a high temperature to accelerate the termination reaction rate, there is a problem that the reaction is difficult to control. In that respect, in the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer depending on the solvent, and by adjusting the amount of the initiator and the reaction temperature. It is preferable to obtain a low molecular weight product in the resin composition used in the present invention. In particular, the solution polymerization method under a pressurized condition is also preferable in that the amount of the initiator used is minimized and the influence of the initiator residue is suppressed as much as possible.

Examples of the polymerization method that can be used in the present invention as a method for synthesizing the high molecular weight component of the binder resin according to the present invention include a solution polymerization method, an emulsion polymerization method and a suspension polymerization method.

Of these, the emulsion polymerization method is a method in which a monomer (monomer) almost insoluble in water is dispersed in the aqueous phase as small particles with an emulsifier, and polymerization is performed using a water-soluble polymerization initiator. . In this method, it is easy to control the heat of reaction, and the phase in which the polymerization takes place (oil phase consisting of polymer and monomer)
And the aqueous phase are different, the termination reaction rate is low, and as a result, the polymerization rate is high and the polymerization degree is high. Further, in the production of toner, due to the relatively simple polymerization process and the fine particles of the polymerization product,
It is advantageous as a method for producing a binder resin for a toner because it can be easily mixed with a colorant, a charge control agent and other additives.

However, the resulting polymer is apt to become impure due to the added emulsifier, and an operation such as salting out is required to take out the polymer, and suspension polymerization is convenient for avoiding this inconvenience.

In the suspension polymerization, 100 parts by mass or less of the monomer (preferably 1 part by mass) is used with respect to 100 parts by mass of the aqueous solvent.
0 to 90 parts by mass) is preferable. As dispersants that can be used, polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, and the like are used, and generally 0.05 to 1 part by mass relative to 100 parts by mass of the aqueous solvent. The polymerization temperature is suitably 50 to 95 ° C., but it is appropriately selected depending on the initiator used and the target polymer.

The high molecular weight component of the binder resin used in the present invention is preferably produced by using a polyfunctional polymerization initiator alone or in combination with a monofunctional polymerization initiator as exemplified below. By using a polyfunctional polymerization initiator, a polymer having a molecular weight suitable for use in the present invention can be easily obtained.

Specific examples of the polyfunctional polymerization initiator having a polyfunctional structure include 1,1-di-t-butylperoxy-
3,3,5-trimethylcyclohexane, 1,3-bis- (t-butylperoxyisopropyl) benzene,
2,5-dimethyl-2,5- (t-butylperoxy)
Hexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexyne-3, tris- (t-butylperoxy) triazine, 1,1-di-t-butylperoxycyclohexane, 2 , 2-di-t-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxy Azelate, di-t-butylperoxytrimethyl adipate, 2,2-bis- (4,4-di-t-
Butyl peroxycyclohexyl) propane, 2,2-
A polyfunctional polymerization initiator having a functional group having a polymerization initiation function such as two or more peroxide groups in one molecule, such as t-butylperoxyoctane and various polymer oxides, and diallyl peroxydicarbonate, t- Both a functional group having a polymerization initiation function such as a peroxide group and a polymerizable unsaturated group are contained in one molecule such as butyl peroxy maleic acid, t-butyl peroxy allyl carbonate and t-butyl peroxy isopropyl fumarate. Selected from polyfunctional polymerization initiators having.

Of these, more preferred are 1,1
-Di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyase Rate and 2,2-bis- (4,4-di-t-butylperoxycyclohexyl) propane, and t-butylperoxyallyl carbonate.

These polyfunctional polymerization initiators are preferably used in combination with the monofunctional polymerization initiator in order to satisfy various performances required as a binder for toner.
In particular, it is preferable to use together with a polymerization initiator having a decomposition temperature lower than the decomposition temperature for obtaining the half-life of 10 hours of the polyfunctional polymerization initiator.

Specifically, benzoyl peroxide,
1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-di (t
-Butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t
Organic peroxides such as butyl peroxide, azo and diazo compounds such as azobisisobutyronitrile and diazoaminoazobenzene can be used.

These monofunctional polymerization initiators may be added to the monomer at the same time as the polyfunctional polymerization initiator, but in order to keep the initiator efficiency of the polyfunctional polymerization initiator appropriate. It is preferably added after the polymerization time has passed the half-life indicated by the polyfunctional polymerization initiator under arbitrary polymerization conditions.

From the viewpoint of efficiency, these initiators are preferably used in an amount of 0.05 to 2 parts by mass with respect to 100 parts by mass of the monomer.

The high molecular weight component of the binder resin used in the present invention is preferably crosslinked with a crosslinkable monomer as exemplified below in order to achieve the object of the present invention.

As the crosslinkable monomer, a monomer having two or more polymerizable double bonds is mainly used, and specific examples thereof include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, etc .; Diacrylate compounds such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate,
1,5-Pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and compounds obtained by replacing the acrylates of the above compounds with methacrylates; diacrylate compounds linked by an alkyl chain containing an ether bond. , Such as diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and the acrylates of the above compounds replaced with methacrylate Diacrylate compounds linked by a chain containing an aromatic group and an ether bond, for example, polyoxyethylene (2) -2,2-bis ( - hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,
2-bis (4-hydroxyphenyl) propane diacrylate, and those obtained by replacing the acrylate of the above compounds with methacrylates; further, polyester type diacrylate compounds, for example, trade name MANDA (Nippon Kayaku). . As the polyfunctional crosslinking agent, pentaerythritol acrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, and acrylates of the above compounds into methacrylate. And the like; triallyl cyanurate, triallyl trimellitate; and the like.

These cross-linking agents are based on other monomer components 10
0 mass% or less, 1 mass% or less, preferably 0.00
It is preferably used in the range of 1 to 0.05% by mass.

Among these crosslinkable monomers, those which are preferably used from the viewpoints of toner fixability and anti-offset property are those which are linked by a chain containing an aromatic divinyl compound (particularly divinylbenzene), an aromatic group and an ether bond. Diacrylate compounds mentioned above.

The high molecular weight polymer constituting the binder resin according to the present invention is mixed with a low molecular weight wax in advance,
Phase separation in the micro region is relaxed, reaggregation of the high molecular weight component is suppressed, and a good dispersion state with the low molecular weight polymer can be obtained, which is preferable.

Examples of the low molecular weight wax applicable to the present invention include compounds such as polypropylene wax, polyethylene wax, microcrystalline wax, carnauba wax, sazol wax, paraffin wax, higher alcohol wax and ester wax, and oxidation thereof. And graft modified products.

The weight average molecular weight of these low molecular weight waxes is preferably 30,000 or less, more preferably 10,000 or less,
The addition amount is preferably about 1 to 20 parts by mass with respect to 100 parts by mass of the binder polymer component.

These low molecular weight waxes are preferably added and mixed in advance with the binder polymer component during toner production. In particular, a method of preliminarily dissolving the low molecular weight wax and the high molecular weight polymer in a solvent at the time of preparing the polymer component, and then mixing with the low molecular weight polymer solution is preferable.

The solid concentration of the polymer solution depends on the dispersion efficiency,
5 to 70 in consideration of deterioration of resin at the time of stirring and operability.
The solid concentration of the high molecular weight polymer component and the polyolefin polymer is preferably 5 to 60% by mass or less, and the low molecular weight polymer solution is 5 to 70% by mass or less.

The method of dissolving or dispersing the high molecular weight polymer component and the low molecular weight wax is carried out by stirring and mixing, and the stirring is preferably carried out batchwise or continuously.

Then, in the method of mixing the low molecular weight polymer solution, it is preferable that 10 to 1000 parts by mass of the low molecular weight polymer solution is added to 100 parts by mass of the solid content of the preliminary solution and the mixture is stirred and mixed. . In this case, a batch system or a continuous system may be used.

Examples of the organic solvent used when mixing the binder resin solution according to the present invention include benzene, toluene, xylol, Solvent Naphtha No. 1, Solvent Naphtha 2
Hydrocarbon solvents such as Solvent Naphtha No. 3, cyclohexane, ethylbenzene, Solvesso 100, Solvesso 150, mineral spirits; methanol, ethanol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, iso-butyl alcohol, Alcohol solvents such as amyl alcohol and cyclohexanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ester solvents such as ethyl acetate, n-butyl acetate, cellosolve acetate; methyl cellosolve, ethyl cellosolve, butyl cellosolve, Examples include ether solvents such as methyl carbitol. Of these, aromatic, ketone and ester solvents are preferred. Moreover, these may be mixed and used.

The method of removing the organic solvent is preferably a method of heating the organic solvent solution of the polymer, removing 10 to 80% by weight of the organic solvent under normal pressure, and then removing the residual solvent under reduced pressure. At this time, it is preferable to keep the organic solvent solution at a temperature not lower than the boiling point of the used organic solvent and not higher than 200 ° C. If the boiling point of the organic solvent is below the range, not only the efficiency at the time of solvent distillation is poor, but also unnecessary shearing force is applied to the polymer in the organic solvent, and redispersion of each constituent polymer is promoted, and in a micro state. May cause phase separation. Further, if the temperature exceeds 200 ° C., the polymer is depolymerized, an oligomer is generated by molecular cleavage, and impurities are mixed into the resin composition, which is not preferable.

As the binder resin for toner used for pressure fixing, low molecular weight polyethylene, low molecular weight polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, higher fatty acid, polyamide Resin and polyester resin may be used. These are preferably used alone or in combination.

The glass transition point Tg of the toner is 55 ° C.
When the temperature is in the range of 75 ° C to 75 ° C (preferably 55 ° C to 70 ° C), the effect of suppressing toner fusion is further improved. If the glass transition point Tg of the toner is less than 55 ° C., the effect of suppressing toner fusion cannot be improved. Further, the glass transition point Tg of the toner is 75 ° C.
When it exceeds, the heat fixing property of the toner is impaired.

Glass transition point Tg of the toner according to the present invention
For example, DSC-7 manufactured by Perkin Elmer Co., Ltd.
As described above, the measurement is performed by a highly accurate internal heat input compensation type differential scanning calorimeter.

The measuring method is ASTM D3418-82.
Carry out according to. In the present invention, the sample is heated once to obtain a previous history, then rapidly cooled, and then again at a temperature rate of 10 ° C./m.
In, a DSC curve measured when the temperature is raised in the range of 0 to 200 ° C. is used.

Further, it is also preferable to include the following waxes in the toner from the viewpoint of improving the releasability from the fixing member during fixing and the fixing property. 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, etc., where the derivatives are oxides and block copolymers with vinyl monomers. , Including graft modified products.

In addition, alcohols, fatty acids, acid amides,
Esters, ketones, hydrogenated castor oil and its derivatives, plant wax, animal wax, mineral wax, petrolactam and the like can also be used.

For the toner of the present invention, it is preferable to use a charge control agent in the toner particles (internal addition) or in the mixture with the toner particles (external addition). The charge control agent makes it possible to control the optimum charge amount according to the development system.
Particularly in the present invention, it is possible to make the balance between the particle size distribution and the charge amount more stable. The following substances control the toner to be negatively charged.

Organic metal complexes and chelate compounds are effective, for example, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid type metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

Further, there are the following substances for controlling the positive charge property.

Modified products of nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and phosphonium salts which are analogs thereof. Onium salts and lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as a laker, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide) Compounds, ferrocyanides, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl Diorgano tin borate such as Suzuboreto; can be used in combination singly or two or more kinds.

The above charge control agents are preferably used in the form of fine particles, and in this case, the number average particle diameter of these charge control agents is preferably 4 μm or less, more preferably 3 μm or less. When these charge control agents are internally added to the toner, it is preferable to use 0.1 to 20 parts by mass, particularly 0.2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

As the colorant used in the present invention, carbon black, a magnetic substance, or a yellow / magenta / cyan colorant shown below, which is toned black, is used.

As the yellow colorant, condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. 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
Etc. are preferably used.

As the magenta colorant, a condensed azo compound, a diketopyrrolopyrrole compound, an anthraquinone, a quinacridone compound, a basic dye lake compound, a naphthol compound, a benzimidazolone compound, a thioindigo compound and a perylene compound are used. 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.

As the cyan colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.

These colorants can be used alone or in the form of a mixture, or in the state of a solid solution. The colorant of the present invention is selected in terms of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner. The amount of the colorant added is 1 to 20 parts by mass based on 100 parts by mass of the resin.

When a magnetic material is used as the black colorant, unlike other colorants, the amount is 30 with respect to 100 parts by mass of the resin.
It is used by adding up to 200 parts by mass.

Examples of the magnetic substance include metal oxides containing elements such as iron, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. Of these, those containing iron oxide as a main component, such as ferrosoferric oxide and γ-iron oxide, are preferable. Further, from the viewpoint of controlling the toner chargeability, other metal elements such as silicon element or aluminum element may be contained. These magnetic particles are B-based by the nitrogen adsorption method.
ET specific surface area is preferably 2 to 3 m ² / g, especially 3 to 28
A magnetic powder having m ² / g and a Mohs hardness of 5 to 7 is preferable.

The shape of the magnetic material is octahedron, hexahedron,
There are spheres, needles, scales, etc., but those having little anisotropy such as octahedrons, hexahedrons, spheres, and irregular shapes are preferable for increasing the image density. The average particle size of the magnetic substance is 0.05 to
1.0 μm is preferable, and 0.1 to 0.
6 μm, and more preferably 0.1 to 0.4 μm.

The amount of magnetic material is 3 with respect to 100 parts by mass of the binder resin.
0 to 200 parts by mass, preferably 40 to 200 parts by mass, and more preferably 50 to 150 parts by mass. If the amount is less than 30 parts by mass, in a developing device that uses magnetic force for toner transportation, the transportability is insufficient, and unevenness in the developer layer on the developer carrier tends to result in image unevenness. The image density tends to decrease due to the above. On the other hand, if the amount exceeds 200 parts by mass, the fixing property tends to have a problem.

As the inorganic fine powder contained in the toner of the present invention, known ones may be used. To improve the charge stability, developability, fluidity and storage stability, silica, alumina,
It is preferably selected from titania and its complex oxides. Furthermore, silica is more preferable. For example, as the silica, both a so-called dry method produced by vapor phase oxidation of a silicon halide or an alkoxide or a dry silica called fumed silica and a so-called wet silica produced from alkoxide, water glass, etc. can be used. However, dry silica having less silanol groups on the surface and inside the fine silica powder and less production residues such as Na ₂ O and SO ₃ ²⁻ is preferable. Further, in the case of dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxide by using other metal halogen compound such as aluminum chloride and titanium chloride together with the silicon halogen compound in the manufacturing process. Also includes.

[0115] 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 given good results in the range of 50 to 400 m ² / g, the toner 100 mass It is particularly preferable to use 0.1 to 8 parts by mass of fine silica powder, preferably 0.5 to 5 parts by mass, more preferably more than 1.0 and up to 3.0 parts by mass per part.

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

The inorganic fine powder used in the present invention is
Silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, other organic silicon compounds, organics for the purpose of hydrophobicizing, controlling chargeability, etc. It is also possible and preferable to treat with a treating agent such as a titanium compound or in combination with various treating agents.

In order to maintain a high charge amount, achieve a low consumption amount 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, the transferability and / or
Alternatively, in order to improve the cleaning property, in addition to the inorganic fine powder, the primary particle diameter is more than 30 nm (preferably the specific surface area is less than 50 m ² / g), more preferably 5
0 nm or more (preferably specific surface area less than 30 m ² / g)
It is also one of the preferable modes to further add the inorganic or organic spherical particles. For example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

In the toner of the present invention, other additives, for example, Teflon powder, zinc stearate powder, polyvinylidene fluoride powder, lubricant powder; cerium oxide powder, silicon carbide Powder,
Abrasives such as strontium titanate powder; fluidity-imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agent, or conductivity-imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder; It is also possible to use a small amount of reverse polarity organic fine particles and inorganic fine particles as a developing property improver.

A known method is used for producing the toner according to the present invention. For example, a binder resin, a wax,
Metal salts or metal complexes, pigments as colorants, dyes,
Alternatively, a magnetic material, if necessary, a charge control agent, other additives and the like are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melt-kneaded by using a heat kneader such as a heating roll, a kneader or an extruder. The metal compound, the pigment, the dye, and the magnetic substance are dispersed or dissolved in the resin to make them compatible with each other, and after solidification by cooling, pulverization and classification are performed to obtain the toner according to the present invention. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

Examples of the surface treatment include a hot water bath method in which pulverized toner particles are dispersed and heated in water, a heat treatment method in which a toner is passed through a hot air stream, and a mechanical impact method in which mechanical energy is applied for treatment. In the present invention, the processing temperature in the mechanical impact method is set to the glass transition point Tg of toner particles.
The thermo-mechanical shock that adds a temperature near (Tg ± 10 ℃)
It is preferable from the viewpoint of aggregation prevention and productivity. More preferably, it is carried out at a temperature in the range of the glass transition point Tg ± 5 ° C. of the toner, in order to reduce the pores having a radius of 10 nm or more on the surface, to effectively work the inorganic fine powder, and to improve the transfer efficiency. It is valid.

The toner according to the present invention is disclosed in Japanese Examined Patent Publication No. 56-56.
No. 13945, etc., a method of atomizing a molten mixture into air using a disk or a multi-fluid nozzle to obtain a spherical toner; JP-B-36-10231;
No. 53856, JP-A-59-61842, a method of directly producing a toner by using a suspension polymerization method, and an aqueous organic solvent in which a monomer is soluble but the obtained polymer is insoluble. It is possible to produce a toner by using a dispersion polymerization method in which a toner is directly produced using a polymer or an emulsion polymerization method represented by a soap-free polymerization method in which a toner is directly produced in the presence of a water-soluble polar polymerization initiator. .

The present invention is also effective when the surface of the image bearing member is mainly composed of a polymer binder. For example, when a protective film mainly composed of a resin is provided on an inorganic image bearing member such as selenium or amorphous silicon, or as a charge transporting layer of a function separation type organic image bearing member, a surface layer comprising a charge transporting material and a resin. In some cases, the above-mentioned protective layer may be further provided on it. As means for imparting releasability to such a surface layer, a resin having a low surface energy is used as the resin forming the film, water repellency,
Examples thereof include adding an additive that imparts lipophilicity, dispersing a material having a high mold release property into a powder, and dispersing the powder. For example, it is achieved by introducing a fluorine-containing group, a silicon-containing group or the like into the resin structure. For this, a surfactant or the like may be used as an additive. Examples thereof include compounds containing a fluorine atom, that is, powders of polytetrafluoroethylene, polyvinylidene fluoride, carbon fluoride and the like. Among these, polytetrafluoroethylene is particularly preferable. In the present invention, it is particularly preferable to disperse the releasable powder such as the fluorine-containing resin in the outermost surface layer.

By these means, the contact angle of water on the surface of the image bearing member can be 85 degrees or more (preferably 90 degrees or more). If it is less than 85 degrees, deterioration of the toner and the toner carrier due to durability tends to occur.

In order to contain 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 image bearing member, or an organic material mainly composed of resin is used. In the case of an image carrier, the powder may be dispersed in the uppermost layer without providing a new surface layer.

The amount of the powder added to the surface layer is preferably 1 to 60% by mass, more preferably 2 to 50% by mass, based on the total mass of the surface layer. If it is less than 1% by mass, the effect of improving the durability of the toner and the toner carrier is insufficient, and 60% by mass
If it exceeds, the strength of the film is lowered, or the amount of light incident on the image carrier is significantly lowered, which is not preferable.

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 image carrier. Compared to corona discharge or the like in which the charging means does not come into contact with the image carrier, the load on the surface of the image carrier is large, so that the effect of improving the life of the image carrier is remarkable, which is one of the preferable application modes.

One of the preferable embodiments of the image carrier used in the present invention will be described below.

Examples of the conductive substrate include metals such as aluminum and stainless steel, aluminum alloys, and indium oxide.
Cylindrical cylinders and films of plastic having a coating layer of tin oxide alloy, paper impregnated with conductive particles, plastic, plastic having conductive polymer, and the like are used.

On these conductive substrates, the adhesiveness of the photosensitive layer is improved, the coatability is improved, the substrate is protected, and 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 subbing layer is polyvinyl alcohol, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, casein, polyamide, copolymer nylon, glue,
It is formed of a material such as gelatin, polyurethane, aluminum oxide or the like. The film thickness is usually 0.1 to 10 μm,
It is preferably about 0.1 to 3 μm.

The charge generation layer includes azo pigments, phthalocyanine pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, squarylium dyes, pyrylium salts, thiopyrylium salts, triphenylmethane dyes, selenium,
It is formed by dispersing a charge generating substance such as an inorganic substance such as amorphous silicon in a suitable binder and coating or vapor depositing. The binder can be selected from a wide range of binder resins, for example, polycarbonate resin, polyester resin, polyvinyl butyral resin, polystyrene resin, acrylic resin, methacrylic resin, phenol resin, silicone resin, epoxy resin, vinyl acetate resin, etc. Is mentioned. The amount of the binder contained in the charge generation layer is 80% by mass.
Below, it is preferably selected to be 0 to 40% by mass. The film thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.05 to 2 μm.

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 transport layer is formed by dissolving a charge transport substance in a solvent, if necessary, together with a binder resin, and coating the solution, and the film thickness thereof is generally 5 to 40 μm. As the charge transport substance, biphenylene is added to the main chain or side chain,
Polycyclic aromatic compounds having a structure such as anthracene, pyrene and phenanthrene, nitrogen-containing cyclic compounds such as indole, carbazole, oxadiazole and pyrazoline,
Hydrazone compounds, styryl compounds, selenium, selenium-
Tellurium, amorphous silicon, cadmium sulfide, etc. may be mentioned.

As the binder resin in which these charge transporting substances are dispersed, polycarbonate resin, polyester resin, polymethacrylate ester, polystyrene resin,
Examples thereof include resins such as acrylic resins and polyamide resins, organic photoconductive polymers such as poly-N-vinylcarbazole, and polyvinylanthracene.

A protective layer may be provided as the surface layer. As the resin for the protective layer, polyester, polycarbonate, acrylic resin, epoxy resin, phenol resin, or a curing agent of these resins may be used alone or in combination.
Used in combination of more than one species.

Further, conductive fine particles may be dispersed in the resin of the protective layer. Examples of the conductive fine particles include metals and metal oxides, and preferably zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide coated titanium oxide, tin coated indium oxide, Antimony coating There are ultrafine particles such as tin oxide and zirconium oxide. These may be used alone or in combination of two or more. Generally, when the particles are dispersed in the protective layer, it is necessary that the particle size of the particles is smaller than the wavelength of the incident light in order to prevent scattering of the incident light by the dispersed particles, and the particles are dispersed in the protective layer in the present invention. The particle diameter of the conductive and insulating particles is preferably 0.5 μm or less. The content in the protective layer is preferably 2 to 90% by mass, more preferably 5 to 80% by mass, based on the total mass of the protective layer. The thickness of the protective layer is preferably 0.1 to 10 μm, more preferably 1 to 7 μm.

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

The contact transfer step applicable to the image forming method of the present invention will be specifically described below.

In the contact transfer step, the developed image is electrostatically transferred to the transfer material while the transfer means is in contact with the electrostatic image carrier and the transfer material. The contact pressure of the transfer means is linear pressure. It is preferably 2.9 N / m (3 g / cm) or more, more preferably 19.6 N / m (20 g / cm).
That is all. The linear pressure as the contact pressure is 2.9 N / m (3
If it is less than g / cm), transfer deviation of the transfer material and transfer failure are likely to occur, which is not preferable.

As a transfer means in the contact transfer step, an apparatus having a transfer roller or a transfer belt is used. The transfer roller is composed of at least a core metal and a conductive elastic layer, and the conductive elastic layer is made of urethane having a conductive material such as carbon dispersed therein or EPDM and has a volume resistance of 10 ⁶ to 1 1.
It is made of an elastic body of about 0 ¹⁰ Ωcm.

The present invention is particularly effectively used in an image forming apparatus in which the surface of the latent image carrier (photoreceptor) is an organic compound. That is, when the organic compound forms the surface layer of the photoconductor, the adhesiveness to the binder resin contained in the toner particles is better than that of other photoconductors using an inorganic material, and the transferability is further reduced. This is because there is a tendency to

Further, examples of the surface substance of the photoreceptor according to the present invention include silicone resin, vinylidene chloride, ethylene-vinyl chloride, styrene-acrylonitrile, styrene-methyl methacrylate, styrene, polyethylene terephthalate and polycarbonate. Without being limited to these, other monomers or copolymers and blends between the above-mentioned binder resins can be used.

Further, the present invention is particularly effectively used for an image forming apparatus having a photoconductor having a small diameter of 50 mm or less. That is, in the case of a small-diameter photoconductor, the curvature with respect to the same linear pressure is large, and the pressure is likely to concentrate at the contact portion. Although it is considered that the same phenomenon occurs in the belt photoreceptor, the present invention has a radius of curvature of 25 at the transfer portion.
It is also effective for an image forming apparatus having a size of less than or equal to mm.

The toner of the present invention is set so that the closest gap between the image bearing member and the toner bearing member is wider than the thickness of the toner layer on the toner bearing member by the member for regulating the toner on the toner bearing member. However, it is particularly preferable from the viewpoint of uniformly charging the toner that the member for regulating the toner on the toner carrier is regulated by the elastic member that is in contact with the toner carrier via the toner.

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

If Ra is less than 0.2 μm, the amount of charge on the toner carrier will be high and the developability will be insufficient. When Ra exceeds 3.5 μm, unevenness occurs in the toner coat layer on the toner carrier, resulting in uneven density on the image. More preferably, it is in the range of 0.5 to 3.0 μm.

Further, since the toner of the present invention has a high charging ability, it is desirable to control the total charge amount of the toner at the time of development, and the surface of the toner carrier according to the present invention contains conductive fine particles and / or a lubricant. It is preferably covered with a dispersed resin layer.

As the conductive fine particles contained in the resin layer coating the surface of the toner carrier, carbon black, graphite, conductive metal oxides such as conductive zinc oxide, and metal complex oxides may be used alone or in combination of two or more. It is preferably used. Further, as the resin in which the conductive fine particles are dispersed, a phenol resin, an epoxy resin, a polyamide resin, a polyester resin, a polycarbonate resin,
Known resins such as polyolefin resins, silicone resins, fluorine resins, styrene resins, and acrylic resins are used. A thermosetting or photocurable resin is particularly preferable.

When the one-component developing method is used in the present invention, a layer thickness smaller than the closest distance (between S and D) between the toner carrier and the latent image carrier is obtained on the toner carrier in order to obtain high image quality. Then, it is preferable that the development is performed in a developing process in which the magnetic toner is applied and an alternating electric field is applied to perform the development.

Further, in the present invention, it is preferable in terms of environmental protection that the charging member and the transfer member are in contact with the photoconductor so that ozone is not generated.

A preferable process condition when a charging roller is used is that the contact pressure of the roller is 5 to 500 g /
cm, when using a DC voltage superimposed with an AC voltage, AC voltage = 0.5 to 5 kVpp, AC frequency =
50 to 5 kHz, DC voltage = ± 0.2 to ± 5 kV.

Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means have an effect that a high voltage is unnecessary and ozone generation is reduced.

As the material of the charging roller and the charging blade as the contact charging means, conductive rubber is preferable, and a releasing film may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), fluoroacrylic resin, etc. can be applied.

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

In FIG. 1, a photosensitive drum 100 is provided with a primary charging roller 117, a developing device 140, a transfer charging roller 114, a cleaner 116, a register roller 124 and the like around the photosensitive drum. And the photosensitive drum 100
Is charged to −700 V by the primary charging roller 117 (applied voltage is AC voltage −2.0 kVpp, DC voltage −700 Vdc). Then, the laser light 123 is applied to the photosensitive drum 100 by the laser generator 121, so that the photosensitive drum 100 is exposed. The electrostatic latent image on the photosensitive drum 100 is developed with a one-component magnetic toner by the developing device 140,
Transfer roller 1 that is in contact with the photosensitive drum via the transfer material
It is transferred onto the transfer material by 14. The transfer material on which the toner image is placed is conveyed to the fixing device 126 by the conveyor belt 125 or the like and fixed on the transfer material. The toner partially left on the electrostatic latent image carrier is cleaned by the cleaning unit 116.

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 photosensitive drum 100 and the developing sleeve 102 is maintained at about 300 μm by a sleeve / drum gap holding member (not shown). A stirring rod 141 is arranged in the developing device. A magnet roller 104 is fixed and arranged concentrically with the developing sleeve 102 in the developing sleeve. However, the developing sleeve 102 is rotatable. The magnet roller 104 is provided with a plurality of magnetic poles as shown in the drawing. S ₁ influences development, N ₁ regulates toner coat amount, S ₂ influences toner intake / conveyance, and N ₂ influences toner blowout prevention. There is. The elastic blade 1 is used as a member for controlling the amount of magnetic toner attached to the developing sleeve 102 and conveyed.
03 is arranged and the developing sleeve 10 of the elastic blade 103
The amount of toner conveyed to the developing area is controlled by the contact pressure with respect to 2. In the developing area, a DC and AC developing bias is applied between the photosensitive drum 100 and the developing sleeve 102, and the toner on the developing sleeve flies on the photosensitive drum 100 according to the electrostatic latent image and becomes a visible image.

[0157]

EXAMPLES The present invention will be specifically described below with reference to production examples and examples, but the present invention is not limited thereto. In the following formulation, all parts are parts by mass.

[Production Example of Binder Resin] Production of Low Molecular Weight Polymer (L1) -Styrene 80 parts-Acrylic acid-n-butyl 13 parts-Monobutyl maleate 5 parts-Di-t-butyl peroxide 2 parts

Low molecular weight polymer L1 was obtained by a solution polymerization method using the above compound as a solvent in xylene.

When the GPC of the obtained low molecular weight polymer L1 was measured, the weight average molecular weight (Mw) = 1100.
0, the peak molecular weight = 8900.

Production of high molecular weight polymer (H1) -Styrene 80 parts-Acrylic acid-n-butyl 17 parts-Monobutyl maleate 3 parts-Divinylbenzene 0.005 parts-2,2-bis (4,4-di) -T-butylperoxycyclohexyl) propane 0.2 part

A high molecular weight polymer (H1) was obtained by suspension polymerization of the above compound.

When the GPC of the obtained high molecular weight polymer H1 was measured, the weight average molecular weight (Mw) = 170.
The peak molecular weight was 1,000,000.

The above low molecular weight polymer L1 and high molecular weight polymer H1 were mixed in a xylene solution at a ratio of 70:30,
Binder resin 1 was obtained.

[Binder Resin Production Examples 2 and 3] The amount of the initiator in the low molecular weight polymer L1 of Production Example 1 was adjusted to obtain low molecular weight polymers L2 and L3 having the molecular weights shown in Table 1. Binder resins 2 and 3 were produced in the same manner as in Production Example 1 except that they were used.
I got

[Binder Resin Production Examples 4 and 5] The same as Production Example 1 except that the mixing ratio of the low molecular weight polymer L1 and the high molecular weight polymer H1 in Production Example 1 was changed to 60:40 and 80:20. As a result, binder resins 4 and 5 were obtained.

[Production Examples 6 and 7 of Binder Resin] Low molecular weight components and high molecular weight components By adjusting the amounts of -n-butyl acrylate and monobutyl maleate, the acid values shown in Table 1 were obtained. Binder resin 6 in the same manner as in Production Example 1 except for the above.
And 7 were obtained.

[Production Example 8 of Binder Resin] 80 parts of styrene 20 parts of n-butyl acrylate 0.5 parts of divinylbenzene 0.3 parts of di-t-butyl peroxide

Binder resin 8 was obtained by a solution polymerization method using the above compound as xylene.

When the GPC of the obtained binder resin 8 was measured, the weight average molecular weight (Mw) was 230,000, the peak molecular weight was 50,000, and the acid value was 0.2.

[0171]

[Table 1]

(Toner Production Example 1) 100 parts magnetic substance (average particle size 0.22 μm) 100 parts binder resin 1 part iron complex of monoazo dye (negative charge control agent) 2 parts low molecular weight polyolefin (release) Mold agent) 2 parts

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, cooled and crushed the kneaded material roughly with a hammer mill, finely crushed the coarsely crushed material with a jet mill, and the resulting finely crushed material is multi-divided using the Coanda effect. Strict classification was carried out with a classifier to obtain magnetic toner particles. 1.8% by mass based on the obtained magnetic toner particles
Dry silica with a primary particle size of 12 nm that has been hydrophobized with silicone oil and hexamethyldisilazane (B after treatment)
ET specific surface area 120 m ² / g) and 0.2 mass% PMM
A spherical resin particles (primary particle size 0.4 μm) were added and mixed with a mixer to obtain a magnetic toner 1.

The weight average particle diameter of the obtained magnetic toner is 6.
6 μm, number average particle size is 5.5 μm, SF-1 is 14
0, SF-2 was 127, and the specific surface area was 5.3 m ² / cm ³ . The specific surface area of the toner particles is 1.7 m ² / c
It was m ³ . The physical properties of the obtained magnetic toner are shown in Tables 2 and 3
Shown in In the present invention, the particle size was measured using a Coulter Counter Multisizer (manufactured by Coulter).

(Toner Production Examples 2 to 8) Toners 2 to 8 were obtained in the same manner as Toner Production Example 1 except that Binder Resins 2 to 8 were used as the binder resin. Physical properties of the obtained magnetic toner are shown in Tables 2 and 3.

(Toner Production Example 9) 1. As inorganic fine powder
Dry silica having a primary particle size of 12 nm, which has been hydrophobized with 8% by mass of silicone oil and hexamethyldisilazane (B
ET specific surface area of 120 m ² / g) and 0.5% by mass of PMM
A magnetic toner 9 was obtained in the same manner as in Toner Production Example 1 except that the A spherical resin particles (primary particle size 0.4 μm) were added.
Table 2 shows the physical properties of the obtained magnetic toner.

(Toner Production Examples 10 and 11) As a fine inorganic powder, a primary particle size of about 20 was hydrophobized with silicone oil.
nm titanium oxide fine particles (BET specific surface area 100 m ² /
g) and 0.3% by mass of alumina fine particles having a primary particle size of about 20 nm (BET specific surface area 90 m ² / g), respectively, using 1.8% by mass of the silicone oil used in Toner Production Example 1 and hexamethyldisilanezan. Hydrophobized dry silica with a primary particle size of 12 nm (BET specific surface area 120 after treatment)
Magnetic toners 10 and 11 were obtained in the same manner as in Toner Production Example 1 except that the toner was used in combination with m ² / g). Table 2 shows the physical properties of the obtained magnetic toner.

(Toner Production Example 12) A magnetic toner 12 was obtained in the same manner as in Toner Production Example 1 except that the surface treatment by thermo-mechanical impact was not performed. Table 2 shows the physical properties of the obtained magnetic toner.

(Toner Production Example 13) 100 parts magnetic material (average particle size 0.22 μm) 100 parts binder resin 1 part iron complex of monoazo dye (negative charge control agent) 2 parts low molecular weight polyolefin (released) Mold agent) 2 parts

The above materials were mixed in a blender to obtain 130
Melted and kneaded with a twin-screw extruder heated to ℃, cooled and crushed the kneaded material roughly with a hammer mill, finely crushed the coarsely crushed material with a jet mill, and the resulting finely crushed material is multi-divided using the Coanda effect. Strict classification was carried out with a classifier to obtain magnetic toner particles. 0.4% by mass based on the obtained magnetic toner particles
Dry silica having a primary particle size of about 16 nm that has been hydrophobized with hexamethyldisilazane (BET specific surface area after treatment 10
0 m ² / g) and mixed with a mixer to prepare magnetic toner 1
3 was obtained. The weight average particle diameter of the obtained magnetic toner 13 is 1
It was 2 μm. Table 2 shows the physical properties of the obtained magnetic toner.

(Toner Production Example 14) In the same manner as in Toner Production Example 1 except that the inorganic fine powder was not added to the toner particles,
Magnetic toner 14 was obtained. Table 2 shows the physical properties of the obtained magnetic toner.

(Toner Production Example 15) Binder Resin 1 100 parts Carbon Black 5 parts Salicylic Acid Metal Compound 2 parts

After sufficiently melting and kneading the above composition with an extruder, the cooled kneaded material is mechanically coarsely pulverized, and the coarsely pulverized material is collided with a collision plate using a jet flow to finely pulverize, and further the Coanda effect is applied. The finely pulverized product was classified with a conventional airflow classifier, the weight average diameter was 8.2 μm, and SF-1 was 17
3, black toner particles of SF-2 of 160 by the pulverization method were obtained.
2% by mass 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 were externally added to the obtained black toner particles to obtain a black toner 15 having excellent fluidity. It was

A two-component developer was prepared by mixing the above toner and the resin-coated ferrite carrier having an average particle size of about 50 μm at a ratio of 5:95. Table 2 shows the physical properties of the obtained toner.
Shown in

(Toner Production Example 16) The toner particles obtained in Toner Production Example 15 were subjected to thermomechanical impact force (treatment temperature 60).
Surface treatment with isobutyltrimethoxysilane and silicone oil to make the primary particle size about 20
nm titanium oxide fine particles (BET specific surface area 100 m ² /
2% by mass of g) was externally added to obtain a black toner 16.

(Toner Production Example 17) In the toner production example 1, the inorganic fine powder was hydrophobized with 1.8% by mass of silicone oil and hexamethyldisilazane to obtain a primary particle size of 1
2 nm dry silica (BET specific surface area after treatment 120 m
² / g) and 0.5% by mass of hexamethyldisilazane and treated with Production Example 1 except that dry silica having a primary particle size of 40 nm that has been hydrophobized (BET specific surface area after treatment 40 m ² / g) is used. Magnetic toner 17 was obtained in the same manner.

A two-component developer was prepared by mixing the above toner and the resin-coated ferrite carrier having an average particle size of about 50 μm at 5:95, respectively. Table 2 shows the physical properties of the obtained color toners.

[0188]

[Table 2]

[0189]

[Table 3]

<Photoreceptor Production Example 1> As a photoreceptor, the diameter is 3
The base was a 0 mm Al cylinder. A layer having a structure as shown in FIG. 3 was sequentially laminated thereon by dip coating to prepare a photoconductor.

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

(2) Undercoat layer: Mainly composed of modified nylon and copolymer nylon. The film thickness is 0.6 μm.

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

(4) Charge transport layer: Mainly composed of a hole-transporting triphenylamine compound dissolved in a polycarbonate resin (molecular weight of 20,000 by Oswald viscosity method) at a mass ratio of 8:10, and further polytetrafluoroethylene. 10% by mass of powder (particle size: 0.2 μm) was added to the total solid content and uniformly dispersed. The film thickness is 25 μm. 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 type manufactured by Kyowa Interface Science Co., Ltd.

<Photoreceptor Production Example 2> A photoconductor was produced in the same manner as in Photoreceptor Production Example 1 without adding polytetrafluoroethylene powder. The contact angle with water was 74 degrees.

<Photoreceptor Production Example 3> A photoconductor was produced in accordance with Photoreceptor Production Example 1 up to the charge generation layer. For the charge transport layer, a hole-transporting triphenylamine compound dissolved in a polycarbonate resin at a mass ratio of 10:10 was used. Film thickness 20 μm. Furthermore, as a protective layer, a polytetrafluoroethylene powder (particle size: 0.2 μm) was added to the composition obtained by dissolving the same material in a mass ratio of 5:10 in an amount of 30% with respect to the total solid content to obtain a uniform mixture. Was spray-coated on the charge transport layer. Film thickness 5 μm. The contact angle with water was 102 degrees.

Example 1 The image forming apparatus shown in FIGS. 1 and 2 was used.

An organic photoconductor (OPC) drum of Photoconductor Production Example 3 was used as the electrostatic latent image carrier, and the dark portion potential V _d = -70.
0V and bright part potential _VL = -210V. A gap between the photosensitive drum and the developing sleeve is 300 μm, a toner carrier having a layer thickness of about 7 μm and a JIS center line average roughness (Ra) of 0.8 μm is used as a toner carrier, and a surface is a mirror surface having a diameter of 16φ. Using a developing sleeve formed on an aluminum cylinder, a developing magnetic pole of 95 mT (950 gauss), a toner regulating member having a thickness of 1.0 mm and a urethane rubber blade having a free length of 10 mm, 14.7 N / m (15 g / cm).
It was made to contact by the linear pressure.

Phenolic resin 100 parts Graphite (particle size: about 7 μm) 90 parts Carbon black 10 parts

Next, as a developing bias, a DC bias component V _dc = -500V and an AC bias component V to be superimposed
_PP = 1200V and f = 2000Hz were used. Also,
The peripheral speed of the developing sleeve is the peripheral speed of the photoconductor (48 mm / sec).
150% in the forward direction (reverse as the rotation direction)
Speed (72 mm / sec).

A transfer roller as shown in FIG. 7 (made of ethylene-propylene rubber in which conductive carbon is dispersed, volume resistance value of conductive elastic layer 10 ⁸ Ωcm, surface rubber hardness 24)
°, diameter 20 mm, contact pressure 49 N / m (50 g / cm)
Equal to the peripheral speed of the photoconductor (48 mm / sec),
+2000 V was applied as the transfer bias, the magnetic toner A was used as the toner, and the image was printed in the environment of 23 ° C. and 65% RH. As the transfer paper, 75 g / m ² paper was used.

At this time, the transfer efficiency from the photosensitive member to the transfer material was as high as 98%, and there was no dropout of characters or lines in the transfer, and a good image without scattering on the image was obtained.

In the present invention, the evaluation of scattering is as follows.
It is a splattering evaluation in fine fine lines related to the image quality of a graphical image, and a splattering evaluation in a 100 μm wide line, which is more likely to scatter than characters and lines.

The transferability was evaluated by a numerical value obtained by subtracting the Macbeth density of the one with only the tape from the Macbeth density of the one with the transfer toner on the solid black photoconductor taped and stripped off with Mylar tape and stuck on the paper. did.

Further, when the image was continuously printed on up to 6000 sheets and the abrasion amount of the photoreceptor was measured by a film thickness meter, the abrasion amount was 0 to 1
It was very small at μm.

[0207] Further, when images were continuously printed on 2000 sheets in a high temperature environment of 30 ° C and 80% RH and the fusion of the toner to the surface of the photoconductor and the toner carrier was evaluated, the fusion of the photoconductor was found. Did not occur.

Further, fusion with the toner carrier did not occur.

Example 2 Images were produced under the same apparatus and conditions as in Example 1 except that the OPC drum of Photoreceptor Production Example 1 was used as the latent image carrier. As a result, the transfer efficiency from the photoconductor to the transfer material is 96%.
A high transfer rate was shown, and there was no dropout of characters or lines during transfer, and a good image without scattering was obtained on the image. No photoreceptor fusion occurred. Further, fusion with the toner carrier did not occur.

Comparative Example 1 Image formation was carried out under the same apparatus and conditions as in Example 2 except that Toner 13 of Toner Production 13 was used as the black toner. As a result, the transfer efficiency from the photoconductor to the transfer material is 88%.
The toner utilization efficiency was low. In addition, the image had a noticeable dropout of characters and lines. No photoreceptor fusion occurred. Further, fusion with the toner carrier did not occur.

As toners of Examples 3 to 12 , toners 2 to 11 of toner production examples 2 to 11 were used.
Image formation was performed under the same apparatus and conditions as in Example 2 except that Similar to Example 2, a good image having good transfer efficiency, no voids in the transfer of characters or lines, and no scattering on the image was obtained. The results regarding the fusion of the photosensitive member and the fusion of the toner carrier are shown in Table 4.

[0212]

[Table 4]

Comparative Example 2 Image formation was carried out under the same apparatus and conditions as in Example 2 except that Toner 12 of Toner Production Example 12 was used as the toner. As a result, as in the case of Example 2, a good image having good transfer efficiency, no voids in the transfer of characters or lines, and no scattering on the image was obtained. However, the fusion of the photoconductor was recognized on the surface of the photoconductor after 1000 sheets, and appeared on the image after 2000 sheets.

When confirmed after 2000 sheets, a small amount of fusion was observed at the end of the toner carrier.

Comparative Example 3 The same apparatus and conditions as in Comparative Example 1 were used except that Toner 13 of Toner Production Example 13 was used as the black toner and the OPC drum of Photoconductor Production Example 2 was used as the electrostatic latent image carrier. Drawing out. As a result, the transfer efficiency from the photoconductor to the transfer material was 86%, which was lower than that in Example 1, and there were many voids in the transfer of characters and lines, and the images were very scattered.

No fusion of the photoreceptor occurred. Further, fusion with the toner carrier did not occur.

Comparative Example 4 The procedure of Comparative Example 3 was repeated except that the toner 14 of Production Example 14 was used in place of the magnetic toner 13 as the black toner. As a result, the transfer efficiency was as low as less than 70%, the lines were thin, and there were many voids in the transfer of characters and lines, and the images were scattered and poor.

[0218] The fusion of the photoreceptor did not occur. When 2,000 sheets were checked, fusion was observed at the end of the toner carrier.

Example 13 Image formation was carried out under the same apparatus and conditions as in Example 2 except that the two-component magnetic brush development was carried out using Toner 16 of Toner Production Example 16 as the black toner. As a result, as in the case of Example 2, a good image having good transfer efficiency, no voids in the transfer of characters or lines, and no scattering on the image was obtained.
Further, there was no fusion of the photoreceptor. Further, fusion with the toner carrier did not occur.

Comparative Example 5 Images were produced in the same apparatus and conditions as in Example 14 except that Toner 15 of Toner Production Example 15 was used as the toner. As a result, the transfer efficiency from the photoconductor to the transfer material is 85%.
Next, the toner utilization efficiency was low. There was no photoreceptor fusion. Further, fusion with the toner carrier did not occur.

Example 14 Image formation was carried out under the same apparatus and conditions as in Example 1 except that Toner 17 of Toner Production Example 17 was used as the toner. At this time, the transfer efficiency from the photoconductor to the transfer material was as high as 98%, and there was no omission of characters or lines during transfer, and a good image without scattering was obtained.

[0222]

According to the present invention, there is provided a toner having at least toner particles in which a colorant is dispersed in a binder resin and an inorganic fine powder, and having a shape factor SF-1 measured by an image analyzer of the toner. The value is 110 <SF-1 ≦ 180,
The value of the shape factor SF-2 is 110 <SF-2 ≦ 140, the value of the ratio B / A is 1.0 or less, and the BE of the toner is
Specific surface area Sb per unit volume measured by T method
(M ² / cm ³ ) and the specific surface area St (m) per unit volume calculated from the weight average particle diameter when the toner is assumed to be a true sphere.
² / cm ³ ) satisfies the following condition 3.0 ≦ Sb / St ≦ 7.0 Sb ≧ St × 1.5 + 1.5, and the molecular weight in the GPC chromatogram of the THF-soluble portion of the binder resin is It has one peak in the region of 3 × 10 ^{3 to} 3 × 10 ⁴ and has a molecular weight of 1 × 10 ^{5 to} 3 × 1.
0 has ^six areas the peak or shoulder in the toner and the toner image using the toner to the electrostatic latent image bearing member acid value of the binder resin is characterized by a 5~30gKOH / g And an image forming method using an electrophotographic apparatus, which includes a developing step of forming a toner image and a transfer step of transferring the toner image onto the transfer material while bringing a transfer member to which a voltage is applied into contact with the transfer material. It is possible to improve the voids in transfer and the transfer efficiency while maintaining high image density and reproducibility of the latent image. Furthermore, a high-quality and sharp image can be obtained, and neither fusion with the photosensitive member nor fusion with the toner carrier occurs.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an image forming apparatus suitable for the present invention.

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

FIG. 3 is a schematic view showing an example of the configuration of a photoconductor used in the present invention.

FIG. 4 is a schematic view of a charge amount measuring device for measuring the charge amount of toner used in the present invention.

FIG. 5 is a diagram showing a good image (a) having no “transfer blank area” and a defective image (b) having “transfer blank area”.

FIG. 6 is a diagram showing a range of the present invention in shape factors SF-1 and SF-2.

FIG. 7 is a schematic view showing an example of a contact transfer member.

[Explanation of symbols]

 100 Photoconductor (electrostatic latent image carrier) 102 Development sleeve (toner carrier) 103 Contact blade 104 Magnet roller 114 Transfer charging roller 116 Cleaner 117 Primary charging roller 140 Developer 141 141 Stirring bar

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G03G 9/08 372 374 375 (72) Inventor Yuki Nishio 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Motoki Hisaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (35)

[Claims] 1. A toner having at least toner particles in which a colorant is dispersed in a binder resin and an inorganic fine powder, wherein the shape factor SF-1 of the toner measured by an image analyzer is 110 <SF-. 1 ≦ 180, 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. Below, the specific surface area Sb (m ² / cm ³ ) per unit volume of the toner measured by the BET method and the ratio per unit volume calculated from the weight average particle diameter when the toner is assumed to be a true sphere. The surface area St (m ² / cm ³ ) satisfies the following condition 3.0 ≦ Sb / St ≦ 7.0 Sb ≧ St × 1.5 + 1.5, and the THF soluble content of the binder resin is chromatographed by GPC. Gram has one peak in the region of molecular weight 3 × 10 ^{3 to} 3 × 10 ⁴ , and molecular weight 1 × 10 ^{5 to} 3 × 1.
0 has ^six areas the peak or shoulder, the toner acid value of the binder resin is characterized by a 5~30gKOH / g. 2. The ratio (W) of the low molecular weight component (region of less than 5 × 10 ⁴ in the GPC chromatogram) of the binder resin.
L) and high molecular weight (5 in GPC chromatogram)
The toner according to claim 1, wherein the ratio of the ratio (WH) of the region of × 10 ⁴ or more) is WL: WH = 50: 50 to 90:10. 3. The toner according to claim 1, wherein the binder resin is a styrene polymer. 4. The toner according to claim 1, wherein the binder resin has a high molecular weight content of a polymer containing at least a polyfunctional polymerization initiator. 5. The toner according to claim 1, wherein Tg of the binder resin is 55 ° C. to 75 ° C. 6. The toner according to claim 1, wherein the toner is a magnetic toner containing 30 to 200 parts by mass of a magnetic material with respect to 100 parts by mass of a binder resin. 7. SF measured by an image analyzer of the toner
The value of -1 is 120 to 160, and the value of SF-2 is 115 to 140.
The toner according to any one of 1. 8. The inorganic fine powder contained in the toner is at least one kind of inorganic fine powder selected from titania, alumina, silica or a complex oxide thereof. The toner according to any one. 9. The inorganic fine powder contained in the toner is hydrophobized.
9. The toner according to any one of 8 to 8. 10. The toner according to claim 9, wherein the hydrophobized inorganic fine powder contained in the toner is at least treated with silicone oil. 11. The inorganic fine powder contained in the toner has a primary particle diameter of 30 nm or less, and the toner is
11. The toner according to claim 1, further comprising fine powder having a particle size of more than 30 nm. 12. The toner according to claim 11, wherein the fine powder exceeding 30 nm is an inorganic fine powder. 13. The toner according to claim 11, wherein the fine powder exceeding 30 nm is a resin fine powder. 14. The toner according to claim 11, wherein the fine powder having a particle size of more than 30 nm is substantially spherical. 15. The specific surface area per volume of the toner particles measured by the BET method is 1.2 to 2.5 m ² / c.
15. The toner according to claim 1, wherein the toner is m ³ . 16. The toner according to claim 1, wherein a 60% pore radius calculated from an integrated pore area ratio curve of pores of 1 nm to 100 nm of the toner particles is 3.5 nm or less. The toner according to. 17. A developing step of forming a toner image on an electrostatic latent image carrier, and a transfer of transferring the toner image onto the transfer material while bringing a transfer member to which a voltage is applied into contact with the transfer material. In an image forming method using an electrophotographic apparatus having a step, the toner is a toner having at least toner particles in which a colorant is dispersed in a binder resin and an inorganic fine powder, and the shape of the toner measured by an image analyzer. The value of coefficient SF-1 is 1
10 <SF-1 ≦ 180, the value of the shape factor SF-2 is 110 <SF-2 ≦ 140, the value B obtained by subtracting 100 from the value of SF-2, and the value 100 of SF-1. The value of the ratio B / A to the value A is 1.0 or less, and the specific surface area Sb (m ² / cm ³ ) per unit volume of the toner measured by the BET method and the toner are assumed to be spherical. Specific surface area St per unit volume calculated from the weight average particle size
The relationship of (m ² / cm ³ ) satisfies the following conditions 3.0 ≦ Sb / St ≦ 7.0 Sb ≧ St × 1.5 + 1.5, and in the THF-soluble fraction GPC chromatogram of the binder resin. , One peak in the region of molecular weight 3 × 10 ^{3 to} 3 × 10 ⁴ , and molecular weight 1 × 10 ^{5 to} 3 × 1
0 has a peak or shoulder in ⁶ regions of the image forming method, wherein the acid value of the binder resin is 5~30gKOH / g. 18. The ratio (WL) of the low molecular weight component (region of less than 5 × 10 ⁴ in the GPC chromatogram) and the high molecular weight component (region of 5 × 10 ⁴ or more in the GPC chromatogram) of the binder resin. 18. The image forming method according to claim 17, wherein the ratio of the ratio (WH) is WL: WH = 50: 50 to 90:10. 19. The image forming method according to claim 17, wherein the binder resin is a styrene polymer. 20. The image forming method according to claim 17, wherein a high molecular weight component of the binder resin is a polymer using at least a polyfunctional polymerization initiator. 21. The image forming method according to claim 17, wherein the binder resin has a Tg of 55 ° C. to 75 ° C. 22. The image forming method according to claim 17, wherein the toner is a magnetic toner containing 30 to 200 parts by mass of a magnetic material with respect to 100 parts by mass of a binder resin. . 23. S measured by an image analyzer of the toner
The image forming method according to claim 17, wherein the value of F-1 is 120 to 160, and the value of SF-2 is 115 to 140. 24. The inorganic fine powder contained in the toner is one or more kinds of inorganic fine powder selected from titania, alumina, silica or a double oxide thereof. The image forming method according to any one of claims. 25. The image forming method according to claim 17, wherein the inorganic fine powder contained in the toner is hydrophobized. 26. The image forming method according to claim 25, wherein the hydrophobized inorganic fine powder contained in the toner is at least treated with silicone oil. 27. The inorganic fine powder contained in the toner has a primary particle diameter of 30 nm or less, and the toner is
27. The image forming method according to claim 17, further comprising a fine powder having a particle size exceeding 30 nm. 28. The image forming method according to claim 27, wherein the fine powder exceeding 30 nm is an inorganic fine powder. 29. The image forming method according to claim 27, wherein the fine powder exceeding 30 nm is a resin fine powder. 30. The image forming method according to claim 27, wherein the fine powder having a particle size of more than 30 nm is substantially spherical. 31. The specific surface area per volume of the toner particles measured by the BET method is 1.2 to 2.5 m ² / c.
The image forming method according to claim 17, wherein the image forming method is m ³ . 32. The 60% pore radius calculated from an integrated pore area ratio curve of pores of 1 nm to 100 nm of the toner particles is 3.5 nm or less. The image forming method described in 1 .. 33. The contact angle of the surface of the electrostatic latent image bearing member is 8
33. The image forming method according to claim 17, wherein the image forming angle is 5 degrees or more. 34. The substance containing fluorine is contained on the surface of the electrostatic latent image carrier.
The image forming method according to any one of 1. 35. The image forming method according to claim 34, wherein the substance containing fluorine on the surface of the electrostatic latent image carrier is fine powder containing fluorine.