JPH11143116A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner showing excellent electrification property and fluidity with which an image showing good fixing property and excellent reproducibility of fine lines and highlight part can be obtd. SOLUTION: In this electrostatic charge image developing toner containing at least a binder resin and release agent, the toner contains toner particles and fine particles. When the toner is subjected to ultrasonic treatment in water containing a surfactant at normal temp. and under normal pressure and then left to stand at normal temp. and under normal pressure, the compsn. of fine particles collected from the supernatant satisfies 1.5<=Ma/Mb<=10.0, wherein Ma is the weight average mol.wt. of fine particles and Mb is the weight average mol.wt. of whole toner particles. The fine particles contain the release agent by 0.1 to 10 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a toner for developing an electrostatic image for visualizing an electrostatic latent image.

[0002]

2. Description of the Related Art Conventionally, many methods are known as electrophotography. In general, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. The latent image is developed with a toner to form a visible image, 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, pressure, etc. Is what you get.

Various methods have been conventionally proposed as a method of developing with toner or a method of fixing a toner image.

Conventionally, toners used for these purposes are:
Generally, a colorant comprising a dye or a pigment is melt-kneaded in a thermoplastic resin, uniformly dispersed, then finely pulverized by a fine pulverizer, and the finely pulverized material is classified by a classifier to obtain a desired particle size. Has been manufactured.

[0005] Although this method can produce fairly good toners, it does have certain limitations, namely the choice of toner materials. For example, the resin colorant dispersion must be brittle enough to be pulverized in economically feasible manufacturing equipment. However, when the resin colorant dispersion is fragile to satisfy these requirements, when the dispersion is actually finely pulverized at a high speed, the particle size range of the formed particles tends to be widened, and in particular, a relatively large proportion of fine particles Is included in this. Further, a toner obtained from such a brittle material is liable to be further pulverized or powdered in a developing device such as a copying machine. Also,
In this method, it is difficult to completely and uniformly disperse solid fine particles such as a colorant in a resin, and depending on the degree of the dispersion, an increase in fog during image formation, a decrease in image density, color mixing or transparency. Great care must be taken in dispersing the colorant as this will cause defects. Also, by exposing the colorant to the fracture surface of the pulverized particles,
In some cases, the development characteristics may fluctuate.

On the other hand, in order to overcome the problems of the toner caused by these pulverization methods, Japanese Patent Publication Nos.
Various polymerization toners and production methods thereof have been proposed, including the suspension polymerization toners disclosed in Japanese Patent Nos. 10799 and 51-14895 and the like. For example, in a suspension polymerization method toner, a polymerizable monomer, a colorant and a polymerization initiator, and if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to prepare a monomer composition. And then
The monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and simultaneously undergoes a polymerization reaction to obtain toner particles having a desired particle size. In this method, since no pulverization step is included, the toner does not need to be brittle, a soft material can be used as the resin, and the colorant is not exposed on the particle surface, and uniform friction can be achieved. There is an advantage that a toner having chargeability can be obtained. Further, since the particle size distribution of the obtained toner is relatively sharp, even if the classification step is omitted or the classification is performed, the toner can be obtained in a high yield.

The spherical toner formed by these polymerization methods has a uniform shape, so that a latent image, particularly an edge portion, is faithfully developed, and is suitable for high image quality. Further, it is easy to reduce the particle size of the particles, which is suitable for higher image quality.

As described above, the spherical toner solves some of the drawbacks of the toner obtained by the pulverization method, but it has been found that it causes a new drawback. In other words, when the blade is used because the obtained toner is spherical,
Cleaning performance is inferior.

When used in an image forming method of the one-component developing method, it is difficult to control the amount of toner carried on the developing sleeve because the toner is spherical.

In order to solve such a drawback, Japanese Patent Application Laid-Open No.
Japanese Patent Publication No. 26656 discloses a method for making a polymerized toner irregular, but it does not have sufficient transfer efficiency and the like.

Further, a method has been attempted in which fine particles synthesized separately are fixed to toner particles to provide irregularities on the surface of the toner (JP-A-57-45558, JP-A-1-257853, Japanese Unexamined Patent Publication (Kokai) No. 3-83068) increases the number of production steps, and the fine particles deteriorate the developing property and the fixing property.

Japanese Patent Application Laid-Open No. 56-130762 discloses a method in which a surfactant is made to coexist in an aqueous system for the purpose of removing a dispersant in the production of a toner by suspension polymerization. Fine particles (so-called emulsified particles) generated as a reaction also deteriorate the developability and the fixability.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic image, which solves the above-mentioned problems.

More specifically, it is an object of the present invention to provide a toner for developing an electrostatic charge image having good fixability and excellent chargeability and fluidity capable of obtaining an image excellent in fine line reproducibility and highlight reproducibility. It is in.

Another object of the present invention is to provide a toner for developing an electrostatic charge image having excellent cleaning properties.

[0016]

SUMMARY OF THE INVENTION The present invention is a toner for developing an electrostatic charge image having toner particles containing at least a binder resin and a release agent, wherein the toner contains the toner particles and fine particles. The toner is subjected to ultrasonic treatment in water containing a surfactant at normal temperature and normal pressure, left standing at normal temperature and normal pressure, and the composition of the fine particles recovered from the supernatant, the weight of the fine particles The ratio Ma / Mb of the average molecular weight Ma to the weight average molecular weight Mb of all the toner particles satisfies the following relationship: 1.5 ≦ Ma / Mb ≦ 10.0, and the fine particles have a release agent of 0.1 to 10%. The release agent has a weight average molecular weight (Mw) and a number average molecular weight (Mn) ratio (Mw / Mn) in the molecular weight distribution measured by GPC (gel permeation chromatography). , 1.0 to A toner for developing electrostatic images, which is a 2.0.

The present inventors have found that, when the above-mentioned constitution is satisfied, a toner having high charging properties and excellent blocking resistance and excellent durability stability can be obtained while maintaining good fixing properties.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ratio Ma / Mb of the weight average molecular weight Ma of the fine particles to the weight average molecular weight Mb of all the toner particles is as follows.
When the following relationship is satisfied: 1.5 ≦ Ma / Mb ≦ 10.0, both durability stability and fixability are compatible.

If the ratio Ma / Mb is less than 1.5, the release agent present in the fine particles exudes, and as a result, problems occur in the anti-blocking property and fluidity. When Ma / Mb is larger than 10, low-temperature fixing becomes inferior, which is not preferable.

The molecular weight distribution (Mw) of the release agent used
/ Mn) of from 1.0 to 3.0 makes it possible to improve the durability stability and the fixing property. this is,
This is presumably because the sharp distribution of the release agent improves the inclusion of the sharp-melt release agent in the fine particles.

When Mw / Mn exceeds 3.0, the release agent in the microparticles becomes non-uniform, and the release agent projected on the surface deteriorates the chargeability and the fluidity.

Further, the release agent composition contained in the fine particles is
By setting the content within the range of 0.1 to 10% by weight, offset resistance can be achieved.

When the amount of the releasing agent in the fine particles is less than 0.1% by weight, the toner cannot be completely melted in the fixing in the low temperature region, and the releasing effect on the fine particles on the surface is low, so that low-temperature offset is easy. Become. When the amount of the release agent in the microparticles is more than 10% by weight, the release agent tends to protrude on the surface of the microparticles, and as a result, there is a possibility that the chargeability may be hindered or the fluidity may be deteriorated.

In the present invention, "fine particles" were recovered as follows.

1 g of the toner is uniformly dispersed in 100 ml of an aqueous solution in which 0.1 g of a nonionic surfactant (Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved, and the mixture is placed in a 100 ml beaker at room temperature and normal pressure for 10 minutes. And sonication. As an ultrasonic dispersing machine, UMT-50 manufactured by SMT was used.
, And processing at an intensity of 20 kHz and 50 W.

This dispersion is allowed to stand for 24 hours to settle the toner particles. Only the milky white supernatant is collected with a dropper or the like and filtered using a filter paper having a pore size of 0.10 μm.

The solid was washed three times or more with ion-exchanged water and dried under reduced pressure.

The binder resin composition in the present invention was calculated from its NMR spectrum intensity using EX400 manufactured by JEOL Ltd.

In the present invention, the content of the release agent is Perk.
It was calculated from the heat capacity using DSC-7 manufactured by Inn Elmer.

In the present invention, a dispersion liquid is prepared by dispersing 5 mg of toner in 10 ml of water in which 0.1 mg of a nonionic surfactant is dissolved, and a dispersion liquid is prepared using ultrasonic waves (20 kHz, 50 kHz).
When the dispersion is irradiated with W) for 5 minutes, the measured value C of the particles having a particle diameter of 0.6 to 2.0 μm by the flow type particle image analyzer is 3 to 50% by number, and the shape factor SF of the toner particles is
-2 is 100 to 140, and the toner preferably has a weight average particle diameter of 4 to 10 μm.

In the present invention, the measured value C1 of a flow type particle image analyzer (hereinafter referred to as FPIA method) is preferably ₃ to 40% by number. Furthermore, the measured value C is 3 to 35% by number.
It is preferred that Furthermore, the measured value C is 3-30.
More preferably, it is a number%.

If C exceeds 40% by number, fine particles having a particle size of 0.6 to 2.0 μm tend to contaminate the sleeve and the charging member, thereby lowering the toner chargeability and further reducing the toner coatability on the sleeve. And the image tends to have uneven streaks.

Further, the fine particles take in an external additive, lower the fluidity of the toner, and lower the transferability of the toner at the time of durability.

On the other hand, when C is less than 3% by number, the charge amount of the toner increases (charge-up) particularly in a low humidity environment, the toner coatability on the sleeve is reduced, and the halftone image has wavy unevenness. Is more likely to occur.

The C of the present invention is manufactured by Toa Medical Electronics Co., Ltd.
It measured with the flow type particle image analyzer FPIA-1000. In preparing the measurement sample, as a nonionic surfactant,
Contaminone N manufactured by Wako Pure Chemical Industries, Ltd. was used, and UH-50 manufactured by SMT was used as an ultrasonic dispersing machine.

In the present invention, a toner having a shape factor SF-1 of 100 to 160 and a shape factor SF-2 of 100 to 140 is suitably used. More preferably, SF-1 is 100 to 150, S
F-2 is 100 to 130.

SF- indicating the shape factor used in the present invention
1, SF-2 is FE-SEM (S-8 manufactured by Hitachi, Ltd.)
00), 100 toner images are randomly sampled, and the image information is introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface, analyzed, and a value obtained by the following equation is calculated. In the present invention, the shape factors are defined as SF-1 and SF-2.

[0038]

(Equation 1) (AREA: toner projection area, MXLNG: absolute maximum length, PERI: circumference)

The shape factor SF-1 of the toner indicates a degree of sphere, and when it is larger than 160, the shape gradually changes from a sphere to an irregular shape.
SF-2 indicates the degree of unevenness, and if it is larger than 140, the unevenness on the toner surface becomes remarkable. If SF-1 exceeds 160 or SF-2 exceeds 140, transferability and durability may be poor.

Next, a method for producing the toner for developing an electrostatic image of the present invention will be described.

When a surfactant is mixed in a dispersion medium such as water as in the prior art, emulsion polymerization occurs as a side reaction in addition to a toner base having a desired particle size by suspension polymerization to produce fine particles. . Since this side reaction is limited to the polymerizable monomer dissolved in water, the fine particles hardly contain a release agent or a coloring agent. When these particles are used in a developer, the fine particles separate from the toner base and cause a reduction in charging ability and image defects. In addition, the molecular weight of the generated fine particles is very large, and the fixability is not always satisfactory.

In the suspension polymerization using an inorganic compound or the like as a monomer droplet dispersion stabilizer, the present inventors mix a substance having a surface active ability into a monomer dispersoid at a stage prior to a polymerization reaction. It has been found that it is possible to control the exudation of the surfactant substance from the monomer droplets to the dispersion medium in the intermediate stage of the polymerization reaction.

As a result, it has become possible to synthesize fine particles having a composition that improves developability and fixability without complicating the production process.

Furthermore, since these fine particles are formed by the surfactant substance exuding from the inside of the monomer,
Most of the toner adheres to the toner particles, and the toner surface can be appropriately deformed to enhance the cleaning effect.

Furthermore, the present inventors have proposed that by using a substance having the same kind of functional group or the same kind of bond in a part of the monomer internal additive substance (resin, charge control agent, release agent, etc.) as the above-mentioned surfactant substance. It has been found that the exudation of the surfactant substance from the monomer droplets to the dispersion medium can be more easily controlled. This is considered to be due to the interaction between substances having a similar skeleton.

When a surfactant that does not interact with the internal monomer additive is used, the surfactant immediately moves to the dispersion medium, and a very large number of very small particles having a high molecular weight to which the release agent does not enter are used alone. It is not sufficiently satisfactory in developing property and fixing property.

Similarly, when a surfactant is added to a dispersion medium, very large particles having a very high molecular weight, into which a release agent does not enter, are formed alone and satisfactory in developability and fixability. Not something.

In the present invention, it is preferable that the addition amount of the surfactant having an interaction with the internal additive is 0.001 to 0.3% by weight based on the polymerizable monomer.

When the amount of the surface active substance is less than 0.001% by weight based on the amount of the polymerizable monomer, fine particles required for the present invention are not formed. If it exceeds 0.3% by weight, a large amount of fine particles are generated, and the developing property and the fixing property are not satisfactory.

Preferably, the surface active substance used in the present invention is a resin which is simultaneously mixed with the monomer dispersoid,
It is desirable to use a substance that interacts with a charge control agent, a release agent, and the like. For example, between substances having the same kind of functional group (hydroxyl group, carboxyl group, carbonyl group, sulfone group, amino group, nitro group, cyano group, halogen, etc.) and the same kind of bond (amide bond, ester bond, urethane bond, etc.) Interaction.

Examples of the resin include methacrylate, acrylate resin, polyester resin and the like.

Examples of the charge control agent include metal compounds of salicylic acid, alkyl salicylic acid, dialkyl salicylic acid and naphthoic acid.

Examples of the release agent include amide wax and ester wax.

A substance having a carboxyl group is preferable as a surface active substance having an interaction with these resins, charge control agents, release agents and the like.

It is preferable that the toner internal additive and the surface active substance are treated in advance by a mixing device such as an attritor or a kneader.

It is also desirable to optimize polymerization reaction conditions such as polymerization temperature and polymerization time.

When the polymerization temperature is high and the reaction is easy to proceed, not only the molecular weight becomes low, but also the exudation of the surface-active substance is suppressed, and the effect as in the present invention is hardly exhibited. When the polymerization temperature is low and the reaction does not easily proceed, the oozing out of the surface active substance increases, and the generated fine particles adversely affect the development.

Preferably, the fine particles cover 5 to 40% of the surface of the toner particles. this is,
When the fine particles are fixed or in contact with the surface of the toner particles in an amount of 5 to 40%, the cleaning property is improved, and the deterioration of the durability due to the embedding of an external additive or the like is prevented.

When the coverage of the fine particles with respect to all the toner particles is less than 5%, the charge amount of the toner increases (charge-up) particularly in a low humidity environment, the toner coatability on the sleeve is reduced, and the halftone image is reduced. Undulation is likely to occur. Further, since the shape approaches a true sphere, the cleaning property deteriorates.

When the coverage of the fine particles with respect to all the toner particles is more than 40%, a decrease in coloring power and a low-temperature offset in fixing in a low-temperature region are likely to occur. Further, the number of fine particles separated from the toner particles and contaminating the charging member and the like increases.

In the present invention, preferably, when the fine particles are recovered from the toner particles by the above operation, the rate of change of the fine particle coverage before and after the operation is preferably 30% or less. This can be an index indicating that the smaller the rate of change in the coverage of the fine particles, the less the fine particles fall off during external addition or durability.

If the fine particles recovered from the toner particles are larger than 30% of the total fine particles before the operation, the amount of fine particles that separate from the toner particles and contaminate the charging member and the like increases, thereby deteriorating the developability.

The average particle size and coverage of the fine particles in the present invention were determined by randomly sampling 100 toner images using an FE-SEM (S-800) manufactured by Hitachi, Ltd. It was introduced into an image analyzer (Luzex3) manufactured by Co. and analyzed.

In the present invention, the degree of fixation of the fine particles present on the toner surface may be enhanced by thermal treatment or mechanical impact, if necessary.

As the thermal treatment, a wet surface modification with a water-soluble initiator (preferably, potassium persulfate or ammonium persulfate) may be performed in the latter half of the step of forming toner particles or after the formation of toner particles. At this time, 0.005 to 5 parts by weight, more preferably 0.01 to 5 parts by weight of a water-soluble initiator is used per 100 parts by weight of the toner particles, and the reaction is preferably performed at a temperature of 50 to 90 degrees for 60 to 600 minutes. .

Examples of the thermomechanical treatment include a heat treatment method of passing through a hot air stream and a method of treating by applying mechanical energy while rubbing. In the present invention, the rotor is rotated to obtain a mechanical impact force. Is preferable.

The processing temperature is the glass transition point Tg of the toner particles.
A temperature around (Tg ± 10 degrees) is preferable from the viewpoint of prevention of aggregation and productivity.

The release agent used in the toner of the present invention, that is, the substance having a low softening point includes, for example, paraffin wax, polyolefin wax, modified products thereof (for example, oxides and graft-treated products), higher fatty acids and Examples thereof include metal salts, amide waxes, and ester waxes.

Among them, a higher quality full color OHP
Ester wax is particularly preferred in that an image can be obtained.
The structural formulas of typical compounds of the specific ester waxes preferred for the present invention are shown below as general structural formulas (1) to (4).

[0070]

Embedded image (Where a and b represent an integer of 0 to 4, a + b is 4, R ₁ and R ₂ represent an organic group having 1 to 40 carbon atoms,
And a group in which the carbon number difference between R ₁ and R ₂ is 10 or more,
n and m each represent an integer of 0 to 15, and n and m do not become 0 at the same time. )

[0071]

Embedded image (Where a and b represent an integer of 0 to 4, a + b is 4, R ₁ represents an organic group having 1 to 40 carbon atoms, n and m each represent an integer of 0 to 15, n And m do not become 0 at the same time.)

[0072]

Embedded image (Wherein a and b each represent an integer of 0 to 3, a + b is 3 or less, R ₁ and R ₂ each represent an organic group having 1 to 40 carbon atoms, and carbon atoms of R ₁ and R ₂ A number difference is 10 or more, R ₃ represents an organic group having 1 or more carbon atoms, n and m each represent an integer of 0 to 15, and n and m do not become 0 at the same time.)

The general structural formula of ester wax R ₁ COOR ₂ (wherein R ₁ and R ₂ represent a hydrocarbon group having 1 to 40 carbon atoms, and R ₁ and R ₂ are the same or different carbon atoms. It may be a number.)

The general structural formula of ester wax R ₁ COO (CH ₂ ) _n OOCR ₂ (wherein R ₁ and R ₂ are a hydrocarbon group having 1 to 40 carbon atoms, and n is an integer of 2 to 20) And R ₁ and R ₂ are
They may have the same or different carbon numbers. )

The general structural formula of an ester wax, R ₁ OOC (CH ₂ ) _n COOR ₂ , wherein R ₁ and R ₂ represent a hydrocarbon group having 1 to 40 carbon atoms, and n is an integer of 2 to 20. And R ₁ and R ₂ are
They may have the same or different carbon numbers. )

It is preferable that the low softening point substance has a weight average molecular weight (Mw) of 200 to 2,000 and a number average molecular weight (Mn) of 150 to 2,000. More preferably Mw
Is 200 to 1500, more preferably 300 to 1
000 and Mn are preferably 200 to 1500, more preferably 250 to 1000. When the Mw of the low softening point substance is less than 200 and the Mn is less than 150, the blocking resistance of the toner decreases. Mw of low softening point substance
If Mn exceeds 2,000 and Mn exceeds 2,000, the crystallinity of the low softening point substance itself is developed, and the transparency is reduced.

Further, when the weight average molecular weight / number average molecular weight ratio (Mw / Mn) is 1.0 to 3.0, the maximum peak of the DSC endothermic curve of the low softening point substance becomes sharper, The mechanical strength of the toner particles is improved, and particularly excellent toner properties exhibiting sharp melting characteristics at the time of fixing are obtained. In the present invention, Mw / Mn is preferably 2.0 or less, more preferably 1.5 or less.

In the present invention, the molecular weight distribution of the low softening point substance is measured by GPC using a double column under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150C (manufactured by Waters) Column: GMH-MT 30 cm double (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1 0.0 ml / min sample: Inject 0.4 ml of 0.15% sample

Measurement is performed under the above conditions, and the molecular weight of the sample is calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample. In addition, Mark-Hou
The molecular weight is calculated by converting to polyethylene using a conversion formula derived from the win viscosity formula.

The solubility parameter (SP value) of the substance having a low softening point used in the present invention is preferably in the range of 8.4 to 10.5, more preferably 8.5 to 10.0. When a low softening point substance having an SP value of less than 8.4 is used, compatibility with the binder resin to be used is poor, and as a result, good dispersion in the binder resin is difficult to obtain, and not only the fixing region becomes narrow, but also However, sufficient transparency of full color transparency cannot be obtained. SP value is 1
When a low softening point substance exceeding 0.5 is used, in addition to the fact that the toner tends to be blocked when the toner is stored for a long time, the compatibility between the binder resin and the low softening point substance is too good, so In this case, it is difficult to form a sufficient release layer between the fixing member and the toner binder resin layer, and the offset phenomenon is likely to occur.

In the present invention, the solubility parameter (SP) value of the low softening point substance and the binder resin is determined by the Fedors method (Polym. Eng.
Sci. , 14 (2) 147 (1974)).

In order to obtain a sufficiently transparent OHP image with a low heat capacity of the fixing device, it is important to reduce the crystallinity of the low softening point substance contained in the toner. Normally, there are some undissolved toner grain boundaries that did not dissolve even after fixing, and the crystallinity of the low softening point material layer reduced the effective light transmission due to irregular reflection of light, resulting in haze. May cause a decrease. Furthermore, even if the components mixed in the toner are sufficiently dissolved at the time of fixing, if the refractive index difference between the toner layer after the melting and the low softening point material layer formed between the fixing members is large, this is also a problem. It is not preferable because it causes irregular reflection.

An increase in the irregular reflection of light leads to a decrease in the brightness of the projected image and a decrease in the sharpness of the color. In particular, when a reflective overhead projector is used, this problem is further increased than when a transmissive overhead projector is used.

That is, in order to lower the crystallinity of the low softening point substance, it is important to lower the crystallinity of the low softening point substance alone. Further, in order to prevent unmelted toner grain boundaries from being present in the toner fixing layer, the glass transition temperature (Tg) of the binder resin and the melting point (mp) of the low softening point substance should be adjusted as much as possible. For melting, a material having a small melting enthalpy (ΔH), which is the latent heat of the low softening point substance, is particularly preferable. In addition, the solubility parameter (SP) between the binder resin and the low softening point material is used because the melted low softening point material layer quickly moves between the binder resin and the fixing member to form an anti-offset layer.
It is preferable to adjust the difference appropriately.

As a method of measuring the refractive index, a vertical (20 to 3)
A solid sample having a size of 0) × width (8) × thickness (3 to 10) was prepared, and then a small amount of bromonaphthalene was applied to the prism surface in order to improve the adhesion to the prism surface. A method of placing a solid sample on a sample and measuring the refractive index is exemplified.
As a measuring device, for example, Atago's Appe refractometer 2
T.

The difference between the refractive indices of the binder resin and the low softening point substance at a temperature of 25 ° C. is 0.18 or less, more preferably 0.10 or less. When the refractive index difference exceeds 0.18, it is easy to reduce the transparency of the OHP image,
Particularly, a halftone projection image is not preferable because the brightness becomes low.

The melting point of the low softening point substance used in the present invention is preferably from 30 to 150 ° C., more preferably from 50 to 120 ° C. When the melting point of the low softening point substance is lower than 30 ° C., the blocking resistance of the toner,
The control of sleeve contamination and the prevention of contamination of the photoreceptor at the time of copying a large number of sheets are likely to be reduced. Melting point of low softening point substance is 150 ℃
In the case of exceeding the above, excessive energy is required for uniform mixing with the binder resin in the production method of the toner by the pulverization method, and in the production method of the toner by the polymerization method, the viscosity is increased in order to homogenize the binder resin. However, it is not preferable because it is difficult to incorporate a large amount of the device because the size of the device or the amount of compatibility is limited.

In the present invention, the melting point of the low softening point substance is
The temperature was defined as the temperature of the main peak value in the endothermic curve measured according to ASTM D3418-8.

The measurement according to ASTM D3418-8 is performed using, for example, DSC-7 manufactured by Perkin Elmer. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./min. At temperature 20
The measurement is performed in a temperature range from to 200 ° C.

The low softening point substance 100 used in the present invention
The melt viscosity at 0 ° C. is preferably 1 to 50 mpa · sec, more preferably 3 to 30 mpa · s.
A low softening point substance having a sec is particularly preferred.

The melt viscosity of the low softening point substance is 1 mpa · s
When the toner layer thickness is lower than ec, when the toner layer is thinly coated on the sleeve by a toner layer thickness regulating member that regulates the toner layer thickness by an elastic force like an elastic blade in a one-component developing method, the sleeve is contaminated by mechanical shear force. Easy to invite,
Alternatively, even in a two-component developing method, when a toner is developed using a carrier, the toner tends to be damaged due to a shear force between the toner and the carrier, and the external additive is easily buried or the toner is crushed. The melt viscosity of the low softening point substance is 50 mpas.
In the case of exceeding ec, when a toner is produced using a polymerization method, the viscosity of the dispersoid is too high, and it is not easy to obtain a toner having a fine particle diameter having a uniform particle diameter, and a toner having a wide particle size distribution is obtained. It is easy to be.

In the present invention, the melt viscosity of a substance having a low softening point can be measured by a VT-500 manufactured by HAAKE using a cone-plate type rotor (PK-1).

The Vickers hardness of the low softening point substance used in the present invention is preferably in the range of 0.3 to 5.0, and more preferably, the Vickers hardness is 0.5 to 3.0.

A toner containing a substance having a low softening point having a Vickers hardness lower than 0.3 tends to be crushed at a cleaning portion of a copying machine in copying a large number of sheets, and the toner is liable to fuse on the surface of a drum, resulting in a poor image quality. In addition to the fact that black streaks are likely to occur, the toner is transferred to the surface when multiple image samples are stored in a stacked state, and so-called show-through tends to occur, which is not preferable. A toner containing a low softening point substance having a Vickers hardness of more than 5.0 is not preferable because a fixing device used at the time of heating and fixing requires a high pressing force, so that the fixing device needs to have a strength design more than necessary. When fixing is performed using a fixing device having the above pressing force, the offset resistance tends to decrease, which is not preferable.

In the present invention, the hardness of the low softening point substance is measured, for example, by using a Shimadzu Dynamic Ultra Micro Hardness Tester (DUH-
200). The measurement conditions were as follows. After displacing 10 μm at a load speed of 9.67 mg / sec under a load of 0.5 g using a Vickers indenter, holding for 15 seconds, and analyzing the dents on the sample, the Vickers hardness was determined. . As a sample, a sample previously melted using a mold having a diameter of 20 mmφ is molded into a column having a thickness of 5 mm.

The crystallinity of the low softening point substance used in the present invention is preferably 10 to 50%, more preferably 20 to 35%.

When the crystallinity of the low softening point substance is less than 10%, the storage stability and fluidity of the toner tend to deteriorate. When the crystallinity of the low softening point substance exceeds 50%, the transparency of the OHP image tends to deteriorate.

In the present invention, the crystallinity of the low softening point substance is measured by the following formula from the area ratio between the amorphous scattering peak and the crystal scattering peak without using a calibration curve.

[0100]

(Equation 2)

As the measuring device, for example, Rotorflex RU300 (Cu target, point focus, output 50 KV / 250 mA) manufactured by Rigaku Corporation can be mentioned. The measurement method used the transmission method-rotation method, and the measurement angle was 2θ.
= 5 to 35 °.

As described above, the wax used in the present invention has an appropriate affinity with the binder resin to exhibit good low-temperature fixability and offset resistance, has high hydrophobicity and further has a low melting point. Those having low crystallinity are preferred.

As the low softening point substance, ASTM D34
In accordance with 18-8, a low-softening point substance whose endothermic main peak value in a measured DSC endothermic curve shows a value of 55 to 120 ° C, more preferably 60 to 90 ° C is preferable,
In particular, a low softening point substance having a tangent departure temperature of a DSC curve of 40 ° C. or more is more preferable. When the endothermic main peak is less than 55 ° C., the self-cohesive force of the low softening point substance is weak, so that it is difficult to form the inside or the central portion of the toner particles. Precipitates and easily adversely affects development characteristics. Furthermore, the tangent departure temperature is 40
When the temperature is lower than 0 ° C., the strength of the toner particles is reduced, and the development characteristics during the durability test are liable to be reduced. The resulting fixed image also tends to be a sticky image due to the low melting point of the low softening point substance.

On the other hand, when the endothermic main peak exceeds 120 ° C., the material having a low softening point does not easily ooze out at the time of fixing, and the low-temperature fixability decreases. Further, when the toner particles are produced by a direct polymerization method, the solubility in the polymerizable monomer composition is reduced, and the toner particle size of the polymerizable monomer composition in an aqueous medium is reduced. During the granulation of the liquid droplets, a substance having a low softening point precipitates, making granulation difficult, which is not preferable. More preferably, 6
It is in the range of 0-90, most preferably 60-85C.
Further, the low softening point substance has a half width of the endothermic main peak of 10%.
Those having a sharp melt property of not more than 5 ° C, more preferably not more than 5 ° C are good.

The low softening point substance is the binder resin 100 of the toner.
5 to 40 parts by weight, preferably 10 to 3 parts by weight based on parts by weight
It is better to mix 0 parts by weight.

When the blending amount of the low softening point substance is less than the lower limit, the offset prevention effect tends to decrease, and when the blending amount exceeds the upper limit, the blocking resistance decreases and the offset resistance tends to be adversely affected. In particular, in the case of a polymerization toner production method, a toner having a wide particle size distribution tends to be formed.

As the binder resin used in the toner of the present invention, the following binder resins can be used.

For example, homopolymers of styrene and its substituted substances such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride; phenolic resin; naturally modified phenolic resin; naturally modified maleic acid resin; acrylic resin; methacrylic resin; polyvinyl acetate;
Polyurethane; Polyamide resin; Furan resin; Epoxy resin; Xylene resin; Polyvinyl butyral; Terpene resin; Coumarone indene resin; Preferred binders include styrene copolymers and polyester resins.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Double such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide A monocarboxylic acid having a bond or a substituted product thereof; for example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, or dimethyl maleate and a substituted product thereof; for example, vinyl chloride, vinyl acetate, Vinyl esters such as vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; vinyl vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; , Vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether; such vinyl monomers are used alone or two or more.

In the present invention, the TH of the binder resin of the toner is
The number average molecular weight of the F-soluble component is 3,000 to 1,000,000.
00 is preferred.

The styrene-based polymer or styrene-based copolymer may be cross-linked, or may be a mixed resin of a cross-linked resin and a non-cross-linked resin.

As the crosslinking agent for the binder resin, a compound having mainly two or more polymerizable double bonds may be used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; ,
Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups are used alone or as a mixture.

The amount of the crosslinking agent to be added may be as follows.
0.001 to 10 parts by weight based on 00 parts by weight is preferred.

The method for measuring the molecular weight distribution of the THF-soluble component of the resin composition is as follows.

In the case of a polyester resin, a sample for GPC measurement is prepared as follows.

The polyester resin is placed in tetrahydrofuran (THF), left for several hours, shaken well, mixed well with THF (until the polyester resin is no longer united), and allowed to stand for 12 hours or more. At this time, THF
The time of leaving in the inside should be 24 hours or more. Then, the sample processing filter (pore size 0.45 to
0.5 μm, for example, Myshoridisk H-25
5 The product passed through Tosoh Co., Ltd., and can be used as a sample of GPC. The polyester resin concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

In the case of the binder resin, toluene is evaporated from the toluene extract of the toner, and the obtained solid is mixed with chloroform to obtain a chloroform dispersion. The chloroform dispersion is filtered to obtain a chloroform-insoluble solid. And a chloroform solution filtrate. Chloroform is evaporated from the filtrate, and the solid is mixed with THF to prepare a sample for GPC measurement in the same manner as in the case of the polyester resin.

The molecular weight and molecular weight distribution of the THF-soluble component of the polyester resin and the THF-soluble component of the binder resin by GPC were stabilized in a heat chamber at 40 ° C. measured by the following method. THF was passed through the column at a flow rate of 1 ml per minute as a solvent.
Approximately 100 μl of the F sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. As a standard polyester sample for preparing a calibration curve, for example, Tosoh Corporation or Showa Denko KK having a molecular weight of 10 ² to 1
Used of about 0 ^7, it is appropriate to use at least about 10 standard polystyrene samples. The detector has R
An I (refractive index) detector is used. As the column, a plurality of commercially available polystyrene gel columns are preferably combined. For example, a Shodex GPC K manufactured by Showa Denko KK
F-801, 802, 803, 804, 805, 80
6,807,800P combination and Tosoh T
SKge1G1000H (H _XL ), G2000H
(H _XL ), G3000H (H _XL ), G4000H
(H _XL ), G5000H (H _XL ), G6000H
(H _XL ), G7000H (H _XL ) TSKguardc
column, and the like.

In particular, the column configuration was A-8 manufactured by Showa Denko KK
01, 802, 803, 804, 805, 806 and 8
07 are preferred.

The toner of the present invention may contain a charge control agent.

The following substances control the toner to be negatively charged.

For example, organic metal compounds and chelate compounds are effective, and examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid-based metal compounds. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. Also, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, calixarenes, silicon compounds, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene- An acryl-sulfonic acid copolymer, a nonmetal carboxylic acid-based compound and the like can be mentioned.

The following substances control the toner to be positively charged.

For example, denatured products such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds,
Tributylbenzylammonium-1-hydroxy-4
Quaternary ammonium salts such as naphthosulfonate and tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts which are analogs thereof, and lake pigments thereof, triphenylmethane dyes and lake pigments thereof ( Agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide, dicyclohexyl Diorganotin oxides such as tin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate; used alone or in combination of two or more It can be. Of these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

These charge control agents are preferably used in an amount of 0.01 to 20 parts by weight (more preferably 0.5 to 10 parts by weight) based on 100 parts by weight of the resin component.

As the colorant used in the present invention, a black colorant prepared by using carbon black, a magnetic substance, and a yellow / magenta / cyan colorant shown below is used.

Examples of yellow colorants include 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, 109, 110,
111, 128, 129, 147, 168, 180 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
22, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 are particularly preferred.

As the cyan coloring agent used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used.
Specifically, C.I. I. Pigment Blue 1, 7, 15,
15: 1, 15: 2, 15: 3, 15: 4, 60, 6
2, 66 and the like can be particularly preferably used. These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in toner. The amount of the coloring agent is 1 to 100 parts by weight of the resin.
Used in an amount of up to 20 parts by weight.

The additive for imparting various toner properties should have a particle diameter of 1/5 or less of the volume average diameter of the toner particles in view of durability in the toner or when added to the toner. Is preferred. The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As additives for imparting these properties, for example, the following are used.

Examples of the fluidity-imparting agent include metal oxides (silicon oxide, aluminum oxide, titanium oxide, etc.), carbon black, carbon fluoride, silica and the like, and those subjected to a hydrophobic treatment are more preferable. .

Examples of the abrasive include metal oxides (such as strontium titanate, cerium oxide, aluminum oxide, magnesium oxide and chromium oxide), nitrides (such as silicon nitride), carbides (such as silicon carbide), and metal salts (calcium sulfate). , Barium sulfate, calcium carbonate, etc.).

Examples of the lubricant include fluororesin powder (vinylidene fluoride, polytetrafluoroethylene, etc.) and fatty acid metal salts (zinc stearate, calcium stearate, etc.).

Examples of the charge control particles include metal oxides (such as tin oxide, titanium oxide, zinc oxide, silicon oxide, and aluminum oxide) and carbon black.

These additives are used in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the toner particles.
1 to 5 parts by weight are used. These additives may be used alone or in combination of two or more.

Next, a method for producing the toner used in the present invention will be described. The toner used in the present invention can be manufactured using a pulverized toner manufacturing method and a polymerized toner manufacturing method.

In the present invention, a method for producing a pulverized toner includes a binder resin, a substance having a low softening point, a pigment, a dye or a magnetic substance as a colorant, a charge control agent, and other additives as required. The obtained mixture is melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder, and the resin components are mixed with each other to obtain a low softening point substance.
A pigment, a dye, and a magnetic substance are dispersed or dissolved; the resulting kneaded product is cooled and solidified, and then pulverized and classified to obtain a toner.

Further, if necessary, the toner and the desired additives are sufficiently mixed by a mixer such as a Henschel mixer.
The toner used in the present invention can be obtained.

In the present invention, a method for producing a polymerized toner includes a method described in JP-B-56-13945 or the like, in which a molten mixture is atomized into air using a disk or a multi-fluid nozzle to obtain a spherical toner, and a method for producing a spherical toner. JP-10231, JP-A-59-53856, JP-A-59-61
No. 842, a method for directly producing a toner using a suspension polymerization method, and a method for dispersing a toner directly by using a water-soluble organic solvent in which a polymer soluble in a monomer is insoluble. Emulsion polymerization, such as soap-free polymerization, in which a toner is produced by direct polymerization in the presence of a legal or water-soluble polar polymerization initiator, or after preparing primary polar emulsion polymerized particles in advance, and then forming polar particles having the opposite charge. In addition, a toner can be manufactured using a hetero-aggregation method or the like for association.

However, in the dispersion polymerization method, the obtained toner shows an extremely sharp particle size distribution, but the selection of materials to be used is narrow, and the use of an organic solvent is difficult from the viewpoint of waste solvent treatment and solvent flammability. The manufacturing equipment is complicated and easily complicated. The emulsion polymerization method represented by soap-free polymerization is effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier and initiator terminal are present on the surface of the toner particles, the environmental characteristics are likely to deteriorate.

Accordingly, in the present invention, a suspension polymerization method under normal pressure or under pressure, which can easily obtain a fine particle toner having a sharp particle size distribution, is particularly preferable. A so-called seed polymerization method in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

When the direct polymerization method is used in the toner production method of the present invention, the toner can be specifically produced by the following production method. A low-softening point substance, a colorant, a charge control agent, a polymerization initiator, and other additives are added to the monomer, and the monomer system uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like is used as a dispersion stabilizer. Is dispersed in an aqueous phase containing the same by a conventional stirrer, homomixer, homogenizer or the like. Preferably, the stirring speed and time are adjusted so that the monomer droplets have the desired size of the toner particles, and the granulation is performed. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. Polymerization temperature is 40
The polymerization is carried out at a temperature of at least 50 ° C., generally from 50 to 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction,
In order to remove unreacted polymerizable monomers, by-products, and the like that cause odor at the time of fixing the toner, the aqueous medium may be partially distilled off in the latter half of the reaction or after the completion of the reaction. After the reaction,
The generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is generally preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.

A more preferable toner used in the present invention is a toner obtained by a direct polymerization method in which a substance having a low softening point is encapsulated by an outer resin layer by a tomographic plane measurement method using a transmission electron microscope (TEM). It is manufactured. From the viewpoint of fixability, it is necessary to incorporate a large amount of the low softening point substance into the toner, and it is necessary to include the necessary low softening point substance in the outer shell resin. Unless the toner is not encapsulated, the toner cannot be sufficiently pulverized unless special freezing and pulverization is used in the pulverization process, resulting in only a toner having a wide particle size distribution, and toner fusing to the device also occurs. It is very unfavorable. Further, in the freeze-pulverization, the device becomes complicated to prevent dew condensation on the device, and if the toner absorbs moisture, the workability of the toner is reduced, and it is necessary to additionally add a drying step, which causes a problem. As a specific method of encapsulating the low softening point substance, the polarity of the material in an aqueous medium is set smaller for the low softening point substance than for the main monomer,
Further, by adding a small amount of a resin or monomer having a high polarity, a toner having a so-called core-shell structure in which a low softening point substance is coated with an outer shell resin can be obtained. To control the particle size distribution and the particle size of the toner, methods such as changing the type and amount of the dispersant that acts as a poorly water-soluble inorganic salt or protective colloid, and mechanical device conditions such as the peripheral speed of the rotor, the number of passes, and the stirring blades The predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape, the shape of the container, and the solid content concentration in the aqueous solution.

In the present invention, a specific method for measuring the tomographic plane of the toner is as follows. A toner obtained by sufficiently dispersing a toner in an epoxy resin which is curable at room temperature and then curing it in an atmosphere at a temperature of 40 ° C. for 2 days. The product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome equipped with diamond teeth. The morphology of the toner is measured using a transmission electron microscope (TEM). did. In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell.

As the vinyl polymerizable monomer capable of undergoing radical polymerization used in producing a toner by a polymerization method, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer may be used. Can be.

Examples of the monofunctional polymerizable monomer include styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, and p-methylstyrene. n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxy Styrene-based polymerizable monomers such as styrene and p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate,
iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate , Dimethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, acrylic polymerizable monomers such as 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate,
n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl Methacrylic polymerizable monomers such as methacrylate; methylene aliphatic monocarboxylic esters; vinyl acetate;
Vinyl propionate, vinyl benzoate, vinyl butyrate,
Vinyl esters such as vinyl benzoate and vinyl formate;
Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether (G '' _Tp /
G '' _Tp-25 ) Vinyl polymerizable monomers such as vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

As the polyfunctional polymerizable monomer, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6
-Hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis [4- (acryloxydiethoxy) phenyl] propane, trimethylolpropane triacrylate, tetramethylolmethane Tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate,
1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis [4- (methacryloxydiethoxy) phenyl] propane, 2,
2'-bis [4- (methacryloxy / polyethoxy) phenyl] propane, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate, divinylbenzene, divinylnaphthalene, divinylether and the like can be mentioned.

The monofunctional polymerizable monomers can be used alone or in combination of two or more, or a monofunctional polymerizable monomer and a polyfunctional polymerizable monomer can be used in combination. Further, the polyfunctional polymerizable monomer can be used as a crosslinking agent.

In the present invention, in order to form a core-shell structure in the toner, it is preferable to use a polar resin in combination. Examples of polar resins such as polar polymers and polar copolymers that can be used in the present invention are given below.

Examples of the polar resin include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate or a copolymer of a nitrogen-containing monomer and a styrene-unsaturated carboxylic acid ester; Nitrile monomers such as vinyl chloride; halogen-containing monomers such as vinyl chloride; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dibasic acids; unsaturated dibasic acid anhydrides; A polymer or a copolymer of the polymer and a styrene monomer; a polyester; an epoxy resin. More preferred are a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin.

Examples of the polymerization initiator include, for example, 2,2′-
Azobis- (2,4-dimethylvaleronitrile), 2,
2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2 ′
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butylhydro Peroxide, di-t-butyl peroxide, dixyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,
4-tert-butylperoxycyclohexyl) propane,
A peroxide initiator such as tris- (t-butylperoxy) triazine, a polymer initiator having a peroxide in a side chain, a persulfate such as potassium persulfate and ammonium persulfate, and hydrogen peroxide are used. You.

The polymerization initiator is 0.5 to 20 of the polymerizable monomer.
The addition amount by weight is preferable, and it may be used alone or in combination.

In the present invention, a known crosslinking agent or chain transfer agent may be added to control the molecular weight, and the preferable addition amount is 0.001 to 15 parts by weight.

In the present invention, any suitable stable medium may be used as a dispersion medium for producing a polymerization toner by emulsion polymerization, dispersion polymerization, suspension polymerization, seed polymerization, polymerization using a heteroaggregation method, or the like. Use agent. For example, as inorganic compounds, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. As organic compounds, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and its salts, starch, polyacrylamide, polyethylene oxide, poly (hydroxystearic acid-g-methacrylic acid) For example, a methyl-eu-methacrylic acid) copolymer is used.

When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be formed in a dispersion medium.

In the present invention, it is necessary to pay attention to the polymerization inhibitory property and the water phase migration property of the colorant used in the polymerization method toner. It is better to perform a hydrophobic treatment without inhibiting polymerization. In particular, many dyes and carbon blacks have polymerization inhibitory properties, so care must be taken when using them. As a preferable method for surface-treating the dye system, a method in which a polymerizable monomer is previously polymerized in the presence of these dyes is mentioned, and the obtained colored polymer is added to the monomer system. The carbon black may be treated with a substance that reacts with the surface functional group of the carbon black, for example, a polyorganosiloxane, in addition to the same treatment as the above dye.

As described above, the toner used in the present invention preferably has an appropriate SP value difference between the low softening point substance and the binder resin. Specifically, the SP value of the binder resin is preferably low. It is higher than the SP value of the point substance, and this SP value difference is preferably 6.0 to 15.0, more preferably 7.0 to 1
It is good to be 4.0. When the SP value difference is less than 6.0, the low-softening point substance easily appears on the toner surface,
As a result, not only does the storage stability of the toner deteriorate, but also the contamination of the charging member tends to occur. When the SP value difference exceeds 15.0, the dispersibility (compatibility) of the low softening point substance in the binder resin is deteriorated, and the dispersibility of the colorant is also impaired. Is difficult to obtain.

The SP value of the binder resin is preferably 16 to 24, more preferably 17 to 23.
If the SP value of the binder resin is less than 16, the rise due to contact with a charging member such as a carrier is deteriorated, and as a result, fogging toner is scattered. When the SP value of the binder resin exceeds 24, the chargeability of the toner is reduced particularly under high humidity, and the image quality is deteriorated.

The wax melting point of the toner is higher than the glass transition temperature of the binder resin, and the temperature difference is preferably 100 ° C. or less, more preferably 75 ° C. or less, and further preferably 50 ° C. or less. This temperature difference is 10
If the temperature exceeds 0 ° C., the low-temperature fixability will decrease.
Furthermore, if this temperature difference is too close, the temperature range in which both the storability of the toner and the high-temperature offset resistance are compatible is narrowed. Therefore, the temperature difference is preferably 2 ° C. or more.

The glass transition temperature of the binder resin is preferably from 40 ° C. to 90 ° C., more preferably from 50 ° C. to 85 ° C. When the glass transition temperature of the binder resin is less than 40 ° C., the storage stability of the toner is reduced, the fluidity is deteriorated, and a good image cannot be obtained. If the glass transition temperature of the binder resin exceeds 90 ° C., the low-temperature fixability is inferior, and the transparency of full-color transparency is deteriorated. In particular, the halftone portion tends to be dull and a projection image without saturation is likely to be obtained.

The toner of the present invention can usually be used for one-component and two-component developers. As a one-component developer,
When a non-magnetic toner containing no magnetic material is used, there is a method in which a blade or a roller is used to forcibly triboelectrically charge the toner with a developing sleeve and adhere the toner on the sleeve to convey the toner.

When used as a two-component developer, a carrier is used together with the toner of the present invention as a developer. The magnetic carrier is composed of an element consisting of iron, copper, zinc, nickel, cobalt, manganese, and chromium alone or in a composite ferrite state. The shape of the magnetic carrier may be spherical, flat or irregular. Furthermore, the fine structure of the surface state of the magnetic carrier particles (for example, uneven surface)
Is also preferably controlled. In general, a method is used in which magnetic carrier core particles are generated in advance by baking and granulating the inorganic oxide, and then coating the resin with a resin. From the standpoint of reducing the load on the toner of the magnetic carrier, after kneading the inorganic oxide and the resin, pulverizing and classifying to obtain a low-density dispersion carrier, or further, directly kneading the inorganic oxide and the monomer It is also possible to use a method of obtaining a spherical magnetic carrier by suspension polymerization in an aqueous medium.

A coated carrier for coating the surface of the carrier particles with a resin is particularly preferred. As the method, a method of dissolving or suspending the resin in a solvent, applying the resin, and attaching the resin to the carrier, or a method of simply mixing the resin powder and the carrier particles and attaching the mixture is applicable.

The substance fixed to the carrier particle surface varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, and polyacid. , Polyvinyl butyral, amino acrylate resin and the like. These may be used alone or in combination.

The average particle size of these carriers is preferably 1
It is good to have 0-100 micrometers, More preferably, it is 20-50 micrometers.

When a two-component developer is prepared by mixing the toner of the present invention and a magnetic carrier, the mixing ratio is 2 to 15% by weight, preferably 4% by weight as the toner concentration in the developer. Good results are usually obtained at 13% by weight.

[Image Forming Apparatus] Next, FIG. 2 shows a specific example of a multi-color or full-color image forming apparatus applicable when the above toner is a cyan toner, a magenta toner, a yellow toner and / or a black toner. It will be described with reference to FIG.

FIG. 2 shows an image forming apparatus (copier or laser printer) capable of forming a mono-color image, a multi-color image and a full-color image using an electrophotographic process.
FIG. A medium-resistance elastic roller 5 is used as an intermediate transfer member, and a transfer belt 6 is used as secondary contact transfer means.

Reference numeral 1 denotes a rotating drum type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive member) which is repeatedly used as an image carrier, and is rotated at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow. Photoconductor 1 is a-Se, C
It may be a photosensitive drum or a photosensitive belt having a photoconductive insulating material such as dS, ZnO ₂ , OPC, and a-Si.

As the photosensitive member 1, a photosensitive member having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

As the organic photosensitive layer, the photosensitive layer contains a charge generating substance and a substance having charge transport performance in the same layer.
It may be a single layer type, or may be a function-separated type photosensitive layer having a charge transport layer and a charge generation layer as components. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.

The binder resin for the organic photosensitive layer is preferably a polycarbonate resin, a polyester resin, or an acrylic resin, particularly having good transferability and cleaning properties, and poor cleaning, fusion of toner to the photoreceptor, and filming of external additives. Less likely.

In the charging step, there are a system that is not in contact with the photoreceptor 1 using a corona charger, and a contact system that uses a roller or the like, and both systems are used. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 2 is preferably used.

The charging roller 2 basically has a core 2b at the center and a conductive elastic layer 2a forming the outer periphery thereof. The charging roller 2 is pressed against the surface of the photoconductor 1 with a pressing force, and is rotated by the rotation of the photoconductor 1.

The preferable process condition when using the charging roller is that the contact pressure of the roller is 5 to 500 g / cm.
When a DC voltage with an AC voltage superimposed thereon is used, an AC voltage = 0.5 to 5 kVpp and an AC frequency = 50
Hz to 5 kHz, DC voltage = ± 0.2 to ± 1.5 kV, and when DC voltage is used, 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 are effective in that high voltage is not required and generation of ozone is reduced.

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

The photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the primary charging roller 2 during the rotation process.
Then, image exposure means (not shown) (for example, a color separation / imaging exposure optical system for a color original image, a scanning exposure system using a laser scanner for outputting a laser beam modulated corresponding to a time-series electric digital pixel signal of image information) 1) of the target color image.
(For example, a cyan component image) is formed.

Next, the electrostatic image is transferred to the first developing device 4-1.
(Cyan developing device), the first color cyan toner 20
Is developed. The developing device 4-1 is an apparatus unit, which is detachable from the image forming apparatus main body. Developing device 4-1
3 shows an enlarged view of FIG.

In FIG. 3, reference numeral 22 denotes an outer wall containing a one-component non-magnetic cyan toner 20, and a developing sleeve 16 which is disposed inside the outer wall 22 as a toner carrier and opposed to the photoreceptor 1 rotating in the direction of arrow a in FIG. The toner image is formed on the photoconductor 1 by developing the electrostatic image on the photoconductor 1 with toner. The developing sleeve 16 has a substantially semicircular surface on the right as viewed in FIG.
2, the left substantially half circumferential surface is exposed to the outside of the outer wall 22, and is rotatably provided laterally so as to face the photoconductor 1. A minute interval is provided between the developing sleeve 16 and the photoconductor 1. The developing sleeve 16 is driven to rotate in the direction of arrow b with respect to the rotation direction a of the photoconductor 1.

The developing sleeve 16 is not limited to a cylindrical shape, but may be a rotating endless belt.
A conductive rubber roller may be used.

Further, within the outer wall 22, an elastic blade 19 is provided as an elastic regulating member above the developing sleeve 16, and the toner coating roller 18 is located at a position upstream of the elastic blade 19 in the rotation direction of the developing sleeve 16. Is provided. An elastic roller may be used as the elastic regulating member.

The elastic blade 19 is provided so as to be inclined downward toward the upstream side in the rotation direction of the developing sleeve 16, and is in contact with the upper outer peripheral surface of the developing sleeve 16 in the rotation direction.

The toner application roller 18 is used for the developing sleeve 1.
6 is abutted on the opposite side of the photoconductor 1 and is rotatably supported.

In the developing device 4-1, the toner application roller 18 rotates in the direction of arrow c in the above configuration, and carries the cyan toner 20 by the rotation of the toner application roller 18 to supply it to the vicinity of the developing sleeve 16. The cyan toner 20 on the toner applying roller 18 is rubbed against the developing sleeve 16 at a contact portion (nip portion) where the developing sleeve 16 and the toner applying roller 18 are in contact with each other.
6 on.

With the rotation of the developing sleeve 16, the cyan toner 20 adhering to the developing sleeve 16 penetrates between the elastic blade 19 and the developing sleeve 16 at the abutting portion thereof. The surface of the sleeve 16 and the elastic blade 19 are rubbed with each other to provide a sufficient frictional band charge.

Toner 2 triboelectrically charged as described above
Numeral 0 passes through a contact portion between the elastic blade 19 and the developing sleeve 16, a thin layer of the cyan toner 20 is formed on the developing sleeve 16, and is conveyed to the developing unit facing the photoconductor 1. By applying an alternating voltage obtained by superimposing a direct current and an alternating current as a developing bias to the developing sleeve 16 by a bias applying unit 17, the cyan toner 20 on the developing sleeve 16 is transferred corresponding to the electrostatic image of the photoconductor 1, Attach to the electrostatic image to form a toner image.

In the developing section, the cyan toner 20 remaining on the developing sleeve 16 without being transferred to the photosensitive member 1 is collected into the outer wall 22 from the lower portion of the developing sleeve 16 with the rotation of the developing sleeve 16.

The collected cyan toner 20 is peeled off from the developing sleeve 16 by the toner application roller 18 at the contact portion with the developing sleeve 16. At the same time, a new cyan toner 20 is supplied onto the developing sleeve 16 by the rotation of the toner applying roller 18, and the new cyan toner 20 is
It is transported again to the contact portion between the developing sleeve 16 and the elastic blade 19.

On the other hand, most of the peeled cyan toner 20 is transferred to the outer wall 22 by the rotation of the toner applying roller 18.
The toner is mixed with the other toner 20 and the triboelectric charge of the peeled toner is dispersed. The toner at a position distant from the toner application roller 18 is sequentially supplied to the toner application roller 18 by the stirring means 21.

The developing sleeve 16 is preferably a conductive cylinder formed of a metal or alloy such as aluminum or stainless steel. The conductive cylinder may be formed of a resin composition having sufficient mechanical strength and conductivity. Further, the developing sleeve 16 may have a coating layer formed of a resin composition in which conductive fine particles are dispersed on a metal or alloy cylindrical surface.

As the coating layer, a resin material containing conductive fine particles is used. 120k conductive fine particles
Those having a resistance value of 0.5 Ω · cm or less after pressurization at g / cm ² are preferable.

The conductive fine particles include carbon fine particles,
A mixture of carbon fine particles and crystalline graphite, or crystalline graphite is preferred. The conductive fine particles preferably have a particle size of 0.005 to 10 μm.

Examples of the resin material include thermoplastic resins such as styrene resins, vinyl resins, polyether sulfone resins, polycarbonate resins, polyphenylene oxide resins, polyamide resins, fluororesins, cellulose resins, and acrylic resins; A thermosetting resin such as a resin, a polyester resin, an alkyd resin, a phenol resin, a melamine resin, a polyurethane resin, a urea resin, a silicone resin, and a polyimide resin or a photocurable resin can be used.

Among them, those having a releasing property such as silicone resin and fluororesin, or polyether sulfone,
Polycarbonate, polyphenylene oxide, polyamide, phenolic resin, polyester, polyurethane,
Those having excellent mechanical properties such as styrene resins are more preferable. Particularly, an acrylic resin or a phenol resin is preferable.

It is preferable to use 3 to 20 parts by weight of the conductive fine particles per 100 parts by weight of the resin component.

When carbon fine particles and graphite particles are used in combination, it is preferable to use 1 to 50 parts by weight of carbon fine particles per 100 parts by weight of graphite.

The volume resistivity of the resin coat layer of the sleeve in which the conductive fine particles are dispersed is 10 ^{−6 to} 10 ⁶ Ω · cm.
Is preferred.

Magenta developing device 4-2, yellow developing device 4
-3 and the black developing device 4-4 are non-magnetic one-component developing devices having the same structure as the cyan developing device 4-1.

The black developing device alone may be a magnetic one-component developing device using an insulating magnetic toner in some cases.

The intermediate transfer member 5 is driven to rotate at the same peripheral speed as the photosensitive drum 1 in the direction of the arrow.

The first color cyan toner image formed and carried on the photosensitive drum 1 passes through the nip between the photosensitive drum 1 and the intermediate transfer member 5 and is subjected to primary transfer applied to the intermediate transfer member 5. The intermediate transfer is performed on the outer peripheral surface of the intermediate transfer body 5 by the electric field and pressure formed by the bias 6. Hereinafter, this step is referred to as primary transfer. The intermediate transfer member may have a drum shape or an endless belt shape.

Thereafter, similarly, the magenta toner image of the second color, the yellow toner image of the third color, and the black toner image of the fourth color are sequentially superimposed and transferred onto the intermediate transfer member 5, and are synthesized corresponding to the target color image. A color toner image is formed.

The transfer belt 10 is provided in contact with the lower surface of the intermediate transfer member 5 so as to be supported in parallel with the rotation axis of the intermediate transfer member 5. The transfer belt 10 is supported by a bias roller 11 and a tension roller 12.
, A desired secondary transfer bias is applied by a secondary transfer bias source 23, and the tension roller 12 is grounded.

The first to first transfer from the photosensitive drum 1 to the intermediate transfer member 5
The primary transfer bias for the sequential superimposition transfer of the toner image of the fourth color is applied from the bias power supply 6 with a polarity (+) opposite to that of the toner.

First to first transfer from the photosensitive drum 1 to the intermediate transfer member 5
The transfer belt 10 and the intermediate transfer body cleaning roller 7 can be brought into contact with and separated from the intermediate transfer body 5 in the sequential transfer execution step of the fourth color toner image.

The transfer of the composite color toner image superimposed and transferred onto the intermediate transfer member 5 onto the transfer material P is performed by bringing the transfer belt 10 into contact with the intermediate transfer member 5 and moving a registration roller 13. The transfer material P is fed at a predetermined timing to the contact nip between the intermediate transfer body 5 and the transfer belt 10 through the pre-transfer guide 24, and at the same time, the secondary transfer bias is applied from the bias power source 23 to the bias roller 11. Applied. The composite color toner image is transferred from the intermediate transfer member 5 to the transfer material P by the secondary transfer bias. Hereinafter, this step is referred to as secondary transfer. The secondary transfer may be performed by a transfer roller to which a bias is applied.

The transfer material P to which the toner image has been transferred is introduced into a heat-pressure fixing device 25 having a heating roller 14 and a pressure roller 15, and is heat-fixed.

The intermediate transfer member 5 is a pipe-shaped conductive core 5
b and a medium resistance elastic layer 5a formed on the outer peripheral surface thereof. The metal core 5b may be formed by applying a conductive plating to a plastic pipe.

The medium resistance elastic layer 5a is made of silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber,
EPDM (terpolymer of ethylene propylene diene)
A conductive material such as carbon black, zinc oxide, tin oxide, or silicon carbide is mixed and dispersed in an elastic material such as to adjust the electric resistance (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm. It is a solid or foamed layer.

If necessary, after the transfer of the toner image onto the transfer material, the intermediate transfer member
Is cleaned. When there is a toner image on the intermediate transfer member, the cleaning unit is separated from the surface of the intermediate transfer member so as not to disturb the toner image.

For example, cleaning of the intermediate transfer member 5 is performed as follows.
At the same time as the primary transfer from the photosensitive drum 1 to the intermediate transfer body 5, the secondary transfer residual toner on the intermediate transfer body 5 is reversely transferred back to the photosensitive drum 1 and collected by the cleaner 9 of the photosensitive drum 1. It is done by doing.

[0213] The mechanism will be described. Intermediate transfer member 5
The toner image formed on the transfer belt 10 due to a strong electric field formed by applying a secondary transfer bias having a polarity opposite to the charging polarity (non-polarity) of the toner image to the bias roller 11. The image is transferred to the transferred transfer material P.

At this time, the secondary transfer residual toner remaining on the intermediate transfer member 5 without being transferred to the transfer material P is charged to a polarity (positive polarity) opposite to a normal charging polarity (negative polarity). There are many.

However, not all the secondary transfer residual toner is inverted to the positive polarity, and some toners are neutralized and have no charge, and some toners maintain the negative polarity.

The charging means 7 for inverting the toner, which is partially neutralized and has no charge, or maintains the negative polarity, to the opposite polarity, is provided after the secondary transfer position and before the primary transfer position. Provide.

As a result, almost all of the secondary transfer residual toner can be returned to the photosensitive member 1.

The secondary transfer residual toner is reversely transferred to the photosensitive member 1 and the toner image formed on the photosensitive member 1 is transferred to the intermediate transfer member 5.
The primary transfer to the intermediate transfer member 5
The reverse-charged secondary transfer residual toner and the primary-transferred regular toner are reverse-charged in the nip portion between the photosensitive drum 1 and the intermediate transfer member 5 without substantially being electrically neutralized. The transferred toner is transferred to the photosensitive drum 1, and the normally charged toner is transferred to the intermediate transfer member 5.

This is because, by lowering the primary transfer bias, the electric field applied between the photosensitive drum 1 and the intermediate transfer member 5 at the primary transfer nip is weakened, thereby suppressing the discharge at the nip. This is because the polarity of the toner is prevented from changing at the portion.

Further, since the triboelectrification toner has an electrical insulation property, the charges of the opposite polarities cancel each other out in a short time so that the polarity is not reversed or neutralized.

Accordingly, the secondary transfer residual toner charged to the positive polarity on the intermediate transfer member 5 is transferred to the photosensitive drum 1, and the negatively charged toner image on the photosensitive drum 1 is transferred to the intermediate transfer member 5. Each of them behaves independently, such as being transferred to

When an image is formed on one transfer material P by one image formation start signal, after the secondary transfer, the toner image is not transferred from the photosensitive drum 1 to the intermediate transfer body 5 without being transferred.
The secondary transfer residual toner remaining on the intermediate transfer member is reversely transferred to the photosensitive drum 1.

In this embodiment, as the charging means for charging the secondary transfer residual toner on the intermediate transfer member 5, a contact type charging means, specifically, an elastic roller having a plurality of layers is used as the intermediate transfer member cleaning roller 7. Used.

[Fixing Device] The mechanical structure of the fixing device is as follows.
It is preferable to use an elastic roller as a roller (hereinafter referred to as a fixing roller, which corresponds to the heat roller 53 in FIG. 4) on the side where the toner layer on the image support directly contacts. That is, when the fixing roller has elasticity, the surface of the fixing roller itself deforms and presses against the unevenness of the surface of the unfixed toner image. It is effective for uniformity of

FIG. 4 is a diagram showing a configuration example of the fixing device of the present invention. Reference numeral 53 denotes a fixing roller, and a pressure roller 54 is pressed against the fixing roller 53 to perform a driven rotation while forming a nip portion with the fixing roller 53. The fixing roller 53 is in the form of a hollow cylinder, and a halogen heater 55 is built in the hollow space to supply heat necessary for fixing. The pressure roller 54 is heated by a halogen heater 55. To control the temperature of the roller, a thermistor 58 as a temperature detecting element or a thermistor 58 is disposed in contact with the pressure roller 21 in a non-sheet passing area of the fixing roller 53, and the surface temperature of the roller is changed by a resistance value change according to the detected temperature. Upon detection, the current of the halogen heater 55 is controlled by a control device (not shown) so that the roller surface temperature becomes a predetermined value.

In the apparatus of the present embodiment as described above, the unfixed recording material is guided by the guide 62, enters the nip from the right side, receives pressure and heat from the surface of the fixing roller 53, and is fixed. The paper is ejected. Reference numeral 59 denotes a separation claw between the fixed recording material and the fixing roller 53 or the pressure roller 54.

The configuration of the fixing roller 53 is such that an elastic layer is provided on the core shaft of aluminum or the like to have a thickness of several tens μm or more in order to follow the thickness (several to several tens of μm) of the multi-color toner of a single color to four colors of a color image. is necessary. If the elasticity is low, the resolution is lowered due to the unfixed toner concave portion and the collapse of the toner.
It is preferable that the material of the elastic layer be a methyl-based or methyl vinyl-based liquid silicone rubber RTV or LTV type material having elasticity. RTV and LTV on the surface
, A heat-resistant HTV layer may be provided as a lower layer, and a multilayer structure may be provided in which thermal degradation and peeling of the back surface of the surface layer are prevented.

The structure of the pressure roller 21 is the same as that of the fixing roller 53.
Since the elasticity may be smaller than that of the above, simplification is possible and only the layer of HTV, fluoro rubber or the like may be provided on the aluminum core shaft. Of course, a roller having substantially the same configuration as the fixing roller may be used. The applied pressure was 40-60 kgf.

[0229]

The present invention will be described more specifically with reference to the following examples. “Parts” means “parts by weight”.

Example 1 The cyan toner used in the present invention was prepared as follows.

In a 2-liter four-necked flask equipped with a high-speed stirrer TK-homomixer, 910 ion-exchanged water was added.
Was added parts and 0.1 mole / liter -Na ₃ PO ₄ aqueous solution 450 parts to adjust the rotation speed 12000 rpm, it was allowed to warm to 55 ° C.. Here, 1.0 mol / liter-CaCl
₂ 68 parts of an aqueous solution is gradually added, and a minute poorly water-soluble dispersant C
A dispersion medium system containing a ₃ (PO ₄ ) ₂ was prepared.

On the other hand, as the dispersoid, 25 parts of saturated polyester (terephthalic acid-bisphenol A) release agent 40 parts [monoester wax Mw = 510, Mn = 420, Mw / Mn = 1.21, SP value 8.5, melting point 69 (° C.), melt viscosity 9.5 (m · pa · s)] 1.9 parts of zinc di-t-butylsalicylate compound 0.1 part of di-t-butylsalicylic acid 0.1 parts by a Henschel mixer Preliminary mixing was performed and the mixture was melt-kneaded by a kneader.

Subsequently, 67 parts of the kneaded material, 160 parts of styrene monomer, 40 parts of n-butyl acrylate monomer and 10 parts of copper phthalocyanine pigment were mixed and dispersed at a temperature of about 50 ° C. for 2 hours using an attritor.

The mixed dispersoid was added with 2,2
2'-azobis (2,4-dimethylvaleronitrile) 4
And then charged into the dispersion medium system to increase the number of revolutions to 1200.
Granulation was performed for 10 minutes while maintaining at 0 rpm.

Then, the high-speed stirrer was replaced with a propeller stirring spring, polymerization was continued at 55 ° C. for 1 hour at 50 rpm, the internal temperature was raised to 70 ° C., and polymerization was continued for 4 hours. Was heated to 80 ° C., and polymerization was continued for 5 hours.

After the completion of the polymerization, the slurry was cooled and dilute hydrochloric acid was added to remove the dispersant.

By further washing and drying, cyan particles were obtained.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
Many fine particles adhering so as to protrude were observed on the toner surface, and a small amount of fine particles only adhering to the surface was present.

1.5 parts of hydrophobized silica was externally added to 100 parts of the obtained particles to obtain a cyan toner N having excellent fluidity.
o. 1 was obtained. In addition, as measured by a Coulter counter, the weight average particle size was 6.3 μm, and the number variation coefficient was 24%.

For the cyan toner No. 1 is placed in a developing unit 4-1 which is an apparatus unit shown in FIG. 3, and is mounted on the image forming apparatus shown in FIG. 2, and is placed under a normal temperature and normal humidity environment (23 ° C., 60% RH).
An image output test was performed in the mono color mode. 6000
Also in the multiple-sheet durability test, a high-image-density good fog-free fixed image without fog was obtained.

Even after the running of 6,000 sheets, no toner fusion was observed on the toner application roller, the developing sleeve, and the elastic blade, and good developability was exhibited.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

[Example 2] The polymerization conditions were changed to a rotation speed of 500 rpm.
m, the temperature was raised to 55 ° C. for 5 hours, and then the internal temperature was raised to 80 ° C., and polymerization was continued for 5 hours.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

Example 3 The polymerization conditions were the same as in Example 1, except that after 5 hours of reaction, the high-speed stirrer was used again.
rpm, and deformed for 5 minutes. .

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

Example 4 Example 1 was repeated except that di-t-butylsalicylic acid was changed to sodium dodecylbenzenesulfate.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
Many fine particles just adhering to the surface were observed on the surface of the toner, and a small amount of fine particles adhering to the surface were also present.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

Example 5 The toner obtained in Example 1 was subjected to a surface treatment at a peripheral speed of 70 m / s for 2 minutes using a surface reforming apparatus of a type in which a rotor rotates to apply a mechanical impact force. Done.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
The fine particles existing on the surface were fixed on the toner surface while remaining almost in shape.

Next, 100 toner images were randomly sampled, and the image information was introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface and analyzed to calculate shape factors SF-1 and SF-2. After that, SF
-1 was 117 and SF-2 was 114.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

Comparative Example 1 The procedure of Example 1 was repeated, except that di-t-butylsalicylic acid was not added.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
There were almost no fine particles on the toner surface.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

Comparative Example 2 The procedure of Example 1 was repeated, except that di-t-butylsalicylic acid was changed to sodium dodecylbenzenesulfate, and this was added to the dispersion medium.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
On the toner surface, many fine particles only adhering to the surface were observed.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

Comparative Example 3 The procedure of Example 1 was repeated except that di-t-butylsalicylic acid was changed from 0.2 part to 1 part.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
Many fine particles just adhering to the surface were observed on the surface of the toner, and a small amount of fine particles adhering to the surface were also present.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

[Comparative Example 4] The polymerization conditions were changed to a rotation speed of 50 rpm.
And at 10 ° C. for 10 hours.

Table 1 shows the physical properties of the toner, and Table 2 shows the evaluation results.

[Comparative Example 5] The toner obtained in Comparative Example 2 was subjected to a surface treatment at a peripheral speed of 70 m / s for 2 minutes using a surface reforming apparatus of a type in which a rotor rotates to apply a mechanical impact force. Was.

The obtained toner was subjected to FE-SE manufactured by Hitachi, Ltd.
When a toner image was observed using M (S-800),
The fine particles existing on the surface were fixed on the toner surface while remaining almost in shape.

Next, 100 toner images were randomly sampled, and the image information was introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface and analyzed to calculate shape factors SF-1 and SF-2. After that, SF
-1 was 115 and SF-2 was 114.

The evaluation results are shown in Table 2.

[Comparative Example 6] A polypropylene wax [Mw = 30] was used instead of a monoester wax as a release agent.
00, Mn = 540, Mw / Mn = 5.56, melting point 13
0 (° C.), and a melt viscosity of 11.0 (m · pa · s)].

Table 2 shows the evaluation results.

[0271]

[Table 1]

[0272]

[Table 2]

An evaluation method is as follows.

Image Density The solid image portion is measured with a Macbeth reflection densitometer (manufactured by Macbeth). At that time, it was measured with a gloss meter (PG-3D, manufactured by Nippon Shigaku Kogyo Co., Ltd.). A portion having a glossiness of 15 to 20 is measured.

Measurement of fog The measurement of fog was performed using REFLECTOME manufactured by Tokyo Denshoku Co., Ltd.
The measurement was performed using TER MODELTC-6DS, and the cyan toner image was calculated using the following formula using an amber filter. The smaller the value, the less fog.

Fog (reflectance) (%) = [Reflectance of standard paper (%)] − [Reflectance of non-image portion of sample (%)]

Measurement of toner charge amount in each environment The environmental charge amount is measured by the following method after leaving the toner and the carrier all day and night under each environmental condition.

For example, high temperature / high humidity (30 ° C./80% R
H) Under normal temperature / normal humidity (23 ° C./60% RH), low temperature / low humidity (15 ° C./10% RH) environment, the triboelectric charge of the toner is measured based on the blow-off method.

FIG. 1 is an explanatory view of an apparatus for measuring the triboelectric charge of a toner. First, the weight ratio of the toner to the carrier whose frictional charge is to be measured is 1:19 in a metal measuring container 102 having a 500-mesh screen 103 at the bottom.
Is placed in a polyethylene bottle having a capacity of 50 to 100 ml and shaken by hand for 5 to 10 minutes. At this time, the weight of the entire measurement container 102 is weighed W
₁ (g). Next, the suction device 101 (measurement container 102)
(At least the portion in contact with the insulator) is suctioned from the suction port and the air flow control valve 106 is adjusted to adjust the pressure of the vacuum gauge 105 to 250 mmAq. In this state, suction is sufficiently performed, preferably for 2 minutes, to remove the toner by suction. The potential of the electrometer 109 at this time is set to V (volt). Where 10
Reference numeral 8 denotes a capacitor having a capacity of C (μF). The weight of the whole measurement container after suction is weighed and is defined as W ₂ (g). The triboelectric charge (mC / kg) of this toner is calculated as in the following equation.

[0280]

(Equation 3)

Measurement of triboelectric charge of toner on developing sleeve
The frictional charge amount of the toner on the constant developing sleeve is obtained by using a suction type Faraday gauge method.

In the suction-type Faraday gauge method, the outer cylinder is pressed against the surface of the developing sleeve to suck toner on a fixed area on the developing sleeve, and the toner is collected by a filter of the inner cylinder, and the amount of suction of the filter is calculated based on the weight increase of the filter. The weight of the waste toner can be calculated. At the same time, by measuring the amount of electric charge accumulated in the inner cylinder electrostatically shielded from the outside, the amount of frictional charge of the toner on the developing sleeve can be obtained.

Evaluation of Developing Unit During Endurance of Many Sheets When image defects occurred due to the developing unit during endurance of many sheets, image output was interrupted and the surface of the toner application roller, the surface of the developing sleeve, and the elastic blade The surface contamination and the fused state of the toner were visually evaluated.

In the case where no image defects occurred during the running of a large number of sheets, dirt on the surface of the toner applying roller, the surface of the developing sleeve and the surface of the elastic blade, and the fused state of the toner were visually evaluated after the running of the many sheets.

A: Substantially no dirt and toner fusion B: Dirt or toner fusion, but no noticeable image defect C: Severe dirt or toner fusion, image defect

Fixing start temperature and high-temperature offset-free temperature
The temperature of the heating roller and the pressure roller having a surface layer of fluorine resin in degrees heat-pressure fixing device was controlled at 5 ° C. intervals in a temperature range of 100 ° C. to 230 ° C., subjected to fixing at each temperature, obtained The fixed image was rubbed twice with 50 g / cm ² weighted silbon paper, and the image density reduction rate before and after rubbing was 10%.
The following fixing temperature is defined as a fixing start temperature.

The fixing temperature is increased, and the highest temperature at which the offset phenomenon does not occur visually is defined as the high-temperature offset-free temperature.

Measurement of Cohesion of Toner Using a vibrating sieve of a powder tester (manufactured by Hosokawa Micro Co., Ltd.), 400 mesh, 200 mesh, 10 mesh
0 mesh sieves are stacked in ascending order of opening, ie, 10 meshes.
400 mesh, 20 so that 0 mesh is the highest rank
0 mesh and 100 mesh sieves are set in this order.

A sample was added to the set 100 mesh sieve so that the input voltage to the shaking table became 15 V,
At this time, the amplitude of the shaking table is adjusted to fall within the range of 60 to 90 μm, and vibration is applied for about 25 seconds. Thereafter, the weight of the sample remaining on each sieve is measured, and the degree of cohesion is obtained based on the following equation. .
The smaller the value of the degree of aggregation, the higher the fluidity of the toner.

[0290]

(Equation 4)

Toner blocking resistance test About 10 g of the toner was placed in a 100 cc polycup, and
After leaving it at 3 ° C. for 3 days, it is visually evaluated. A: No aggregate is observed. B: Aggregates are observed, but easily collapse. C: Aggregates are observed and do not collapse easily.

[0292]

According to the present invention, ultrasonic treatment is carried out in water containing a surfactant at normal temperature and normal pressure,
By leaving it at normal pressure and setting the composition of the fine particles recovered from the supernatant to a specific range, a toner for electrostatic image development having good fixability, excellent chargeability, fluidity and cleaning properties can be obtained. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a measuring device for measuring a triboelectric charge amount of a toner.

FIG. 2 is a schematic explanatory view showing an example of an image forming apparatus to which the present invention can be applied.

FIG. 3 is a schematic explanatory view showing an example of an apparatus unit of the image forming apparatus shown in FIG.

FIG. 4 is a schematic explanatory view of an image heating and fixing device to which the toner of the present invention can be applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image carrier (photoreceptor) 4 Developing device 16 Developing sleeve 20 Cyan toner 25 Fixing device 51 Core metal 52 Elastic layer 53 Fixing roller 54 Pressure roller 55 Halogen heater 58 Thermistor 60 Transfer paper (recording material) 61 Unfixed color toner 63 Fluorine resin layer (surface layer)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 9/08 381 (72) Inventor Michihisa Mago 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Koji Inaba Inside Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo

Claims (10)

[Claims] 1. An electrostatic image developing toner having toner particles containing at least a binder resin and a release agent, wherein the toner has the toner particles and the fine particles, and the toner has an interface. The ultrasonic treatment is performed in water containing an activator at normal temperature and normal pressure, and the mixture is allowed to stand still at normal temperature and normal pressure. In the composition of the fine particles recovered from the supernatant, the weight average molecular weight Ma of the fine particles and the total toner particles The ratio Ma / Mb of the weight average molecular weight Mb satisfies the following relationship: 1.5 ≦ Ma / Mb ≦ 10.0, and the fine particles contain 0.1 to 10% by weight of a release agent. The release agent has a ratio (Mw) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) in the molecular weight distribution measured by GPC (gel permeation chromatography).
/ Mn) is from 1.0 to 3.0. 2. The toner according to claim 1, wherein the toner is a nonionic surfactant.
A dispersion liquid is prepared by dissolving 5 mg of toner in 10 ml of water in which 1 mg is dissolved, and a particle diameter of 0.6 by a flow type particle image analyzer when the dispersion liquid is irradiated with ultrasonic waves (20 kHz, 50 W) for 5 minutes. The measured value C of a particle having a particle size of
2. The electrostatic image developing toner according to claim 1, wherein the amount is from 50 to 50% by number. 3. The toner according to claim 1, wherein said toner has a shape factor SF-1 of 100 to 100.
160, and the shape factor SF-2 of the toner is 100 to 1
3. The toner according to claim 1, wherein the toner has a weight average particle diameter of 4 to 10 μm. 4. 4. The method according to claim 1, wherein the fine particles are produced by adding a surfactant to a polymerizable monomer system before the start of the reaction of the polymerizable monomer. 4. The toner for developing an electrostatic image according to any one of items 1 to 3. 5. The electrostatic charge image developing apparatus according to claim 1, wherein the surface active substance has the same kind of functional group or the same kind of bond as a part of the structure of the substance added to the toner. toner. 6. The electrostatic image developing toner according to claim 1, wherein the release agent is an ester wax. 7. The electrostatic image developing toner according to claim 1, wherein the charge controlling agent contains a metal compound of a salicylic acid derivative or a metal compound of an oxynaphthoic acid derivative. 8. The electrostatic image according to claim 1, wherein the electrostatic image developing toner is obtained by directly polymerizing a polymerizable monomer composition. Development toner. 9. The toner for developing an electrostatic image according to claim 1, wherein said fine particles are fixed to toner particles. 10. The electrostatic image developing toner according to claim 9, wherein the fixing of the fine particles is performed by thermal or mechanical impact.