JPH01295270A - Electrostatic charge image developing toner and manufacture of same - Google Patents

Abstract

PURPOSE:To obtain an electrostatic charge image developing toner capable of forming an image superior in image quality by obtaining a toner specified in relation between a number average particle diameter and a particle diameter distribution and containing a specified proportion of fluorine element in a surface layer. CONSTITUTION:The entitled spherical toner having superior lubricity and developing, transfer, cleaning, and the like performances can be obtained by dispersing a polymerizable monomer composition containing an electric charge controller and a colorant into an aqueous medium containing calcium phosphate and a fluorine type surfactant, shearing and dividing the liquid drops of the monomer composition into a particle diameter suitable for the toner in the aqueous medium, subjecting the monomer to suspension polymerization, and forming polymer particles containing the fluorine element in an F/C atomic ratio of 0.01-1.0 in the surface layers of the particles and having a particle diameter of 5-25mum, and a particle diameter variance coefficient (y) defined by equation 1 and satisfying expression II, where S is the standard deviation of the number average particle diameter distribution (mum), and (x) is number average particle diameter (mum).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a dry toner for developing electrostatic images in electrophotography, electrostatic recording, and electrostatic printing.

A developing method using a dry toner whose main components are a colorant and a resin is as follows: (1) The dry toner is mixed with a carrier whose particle size is larger than that of the toner, and the I/toner is charged by friction, which is opposite to the charge of the electrostatic latent image. A method using a two-component developer which imparts a polar charge and develops the electrostatic latent image by bringing a developer, which is a mixture of toner and carrier, into contact with the electrostatic latent image. There is a method using a one-component developer that is developed in contact with or in close proximity to an electrostatic latent image.

[Problems to be solved by conventional techniques and inventions] Conventionally,
To obtain these toners, thermoplastic resins are melted and
To this, coloring agents such as dyes and pigments, as well as magnetic substances, triboelectric charge control agents, off-cera h inhibitors, lubricants, etc., are added and mixed thoroughly, and the mixture is cooled and solidified. After finely pulverizing, the desired particles are A method of classification to obtain the diameter has been implemented.

However, there are various drawbacks to the dual method. Firstly, equipment associated with many processes such as polymerization equipment for resin production, equipment for mixing and purification, crushers, classifiers, etc. is required, and the number of steps is large and energy consumption is large. This is the cause of the increase in The second reason is that it is difficult to obtain a uniform mixture in the kneading process, and the conditions for uniform dispersion are particularly delicate. Thirdly, the pulverization process does not only yield fine powder in the appropriate particle size range to obtain clear, fog-free images; fine and coarse particles are produced as by-products that must be classified and removed. There are drawbacks that lead to increased costs, such as the complexity of the process and poor yield for obtaining the desired particle size range.

Fourth, the resulting powder has an angular and amorphous shape due to the pulverization, and the fluidity of the fine powder is poor, and the image fogging is caused by the fine powder generated by both pulverization due to stirring during frictional charging. can be mentioned.

In contrast, Special Publication No. 36-10231, Special Publication No. 47
Publications such as Japanese Patent Publication No. 518305 and Japanese Patent Publication No. 14895/1989 describe methods for producing toners by suspension polymerization. This suspension polymerization method does not require pulverization and the manufacturing process is simplified, so it can be said that the above-mentioned drawbacks have been improved.

(by suspension polymerization method) The method for producing the gelatin is to prepare a mixture of colorants, charge control agents, etc. dispersed in polymerizable monomers, usually by adding a water-soluble polymeric substance such as polyvinyl alcohol, gelatin, or calcium phosphate, This is a method in which monomer droplets are atomized to a desired particle size by mechanical force in an aqueous medium in the presence of a dispersion stabilizer such as a poorly water-soluble inorganic salt such as calcium carbonate, and then polymerized. ner is obtained.

Although the spherical toner compensates for the drawbacks of the pulverization method 1 to toner as described above, it has been found, however, that the spherical toner also causes new drawbacks. In other words, although spherical toner has excellent fluidity, the adhesion force (νan der aals force) with the carrier or photoconductor is much larger than that of pulverized toner, and this adhesion force decreases as the particle size becomes smaller. It tends to become larger relative to the Coulomb force, causing various problems.

A specific phenomenon is that with such spherical toner, during development, toner with a small particle size is difficult to separate from the carrier, so there is an abnormally strong tendency to consume toner with a larger particle size, and the developer As a result of small particle size toner being accumulated in the toner, the particle size distribution becomes unbalanced when a large number of copies are made, resulting in a situation where performance such as image quality and charge amount cannot be maintained. Furthermore, even if the toner is developed on the photoreceptor,
Due to this adhesion force, relatively small particle size toner
It is difficult to transfer onto copy paper, resulting in a decrease in transfer efficiency, and it also becomes difficult to be scraped off by a blade during the cleaning process, resulting in significant cleaning failure.

To address these problems, various efforts have been made to reduce the adhesion force. For example, a method using a toner made of a mixture of spherical particles and irregularly shaped particles produced by pulverization has been proposed (Japanese Patent Application Laid-open No. 123857/1983), but such a method has the disadvantages associated with the above-mentioned pulverized toner. has not been solved at all, and the mixing ratio of spherical particles and irregularly shaped particles is 10:100 to 60:100.
The proportion of irregularly shaped particles is higher, and the cost advantage of using the suspension polymerization method is halved. In addition, there is a method of obtaining an amorphous toner by using a suspension polymerization method by adjusting the mixing ratio of a surfactant and a dispersant to a specific ratio (Japanese Patent Application Laid-Open No.
1-67039), but this method has poor dispersion stability during polymerization, produces many aggregates, and can only obtain toner particles with a relatively wide particle size distribution, so classification is not required. There are many problems, such as the need for

On the other hand, JP-A-48-47346 and JP-A-58-25
Each publication of No. 046 discloses a method of externally adding fine particles of a fatty acid metal salt represented by zinc stearate to a toner powder or a developer as a so-called cleaning aid. However, although this method is relatively effective for pulverized toner, it is rarely used for spherical toner produced by suspension polymerization because the adhesion of the toner to the photoreceptor is extremely strong as described above. has no effect. Furthermore, with this method, during continuous copying of a large number of sheets, image quality deteriorates due to filming of fatty acid metal salt particles on the photoreceptor surface, and fatty acid metal salt particles accumulate in the developer, resulting in changes in charging properties. There are problems such as.

Furthermore, from the above-mentioned point of view that toners with small particle diameters have a relatively strong adhesion force, it is considered effective to narrow the particle size distribution and eliminate toners with fine particle diameters, so-called fine powder toners.

For example, JP-A-59-53856, JP-A-59-57
No. 252, JP-A-59-57254, JP-A-60-5
No. 7856 and Japanese Unexamined Patent Publication No. 117256/1986,
A method of narrowing the particle size distribution by combining positively or negatively charged silica with an oppositely charged polymer and using this as a dispersant is disclosed. However, even in this method, although some improvement in the particle size distribution was observed and it approached the distribution of ordinary pulverized and classified toner, it is still insufficient from a practical level.

An object of the present invention is to provide a spherical toner obtained by a suspension polymerization method for electrostatic image development that maintains its advantages such as excellent fluidity and solves the problems associated with the spherical shape described above. be.

Another object of the present invention is to provide a spherical toner obtained by a suspension polymerization method for developing electrostatic images, which has excellent developability, transferability, and cleanability.

[Failure to solve the problem]

As a result of intensive studies to solve the above-mentioned problems, the present inventors found that the particle has a specific proportion of fluorine atoms in its surface layer, and that the average particle size and particle size distribution have a specific relationship based on the number of fluorine atoms. By obtaining a toner having a spherical toner, it is possible to overcome the drawbacks associated with spherical toners, and to obtain a toner for developing electrostatic images with poor image quality that maintains poor developing characteristics, transfer characteristics, and cleaning properties even when a large number of sheets are continuously copied. This discovery led to the completion of the present invention.

That is, the present invention contains fluorine atoms in the particle surface layer with a fluorine/carbon atomic ratio in the range of 0.01 to 1.0, has a number average particle size of 5 to 25p, and has the following formula: Particle size variation coefficient yy = (S/x) X 1 defined by (1)
00 (%) ...(1) [S is the standard deviation of the particle size number distribution, × is the number average particle diameter (p)] is the range that satisfies the following inequality (2) % formula % (2) The present invention relates to a toner for developing electrostatic images characterized by comprising spherical toner particles.

In the present invention, the spherical toner refers to a toner having a spherical shape or a table tennis shape without an acute angle portion.

The toner of the present invention will be described in detail below.

In the present invention, the fluorine/carbon atomic ratio of the toner particle surface layer is determined by ESCA (electron 5 spectro
scope for chemical analysis
It is determined by surface analysis according to s). That is, it is a value obtained by taking the ratio of the peak areas of the pus electron spectrum and the C+s electron spectrum obtained by ESCA measurement of the target toner. However, these peak areas were determined based on a commonly used method using values corrected by the relative intensity of each element and measurement sensitivity.

Therefore, the fluorine/carbon atomic ratio of the toner particle surface layer in the present invention represents the thickness analyzed by ESCA from the true surface, that is, the abundance ratio of atoms in the surface layer of at most 100 people.

In the toner of the present invention, the fluorine/carbon atomic ratio is 0.
Fluorine atoms are present in the range of 0.01 to 1.0, preferably 0.02 to 0.5, more preferably 0.05 to 0.3. The presence of fluorine atoms in the surface layer improves the lubricity and releasability of the toner surface, resulting in reduced adhesion to the photoreceptor or carrier.

When the fluorine/carbon atomic ratio is less than 0.01,
If sufficient effect is not obtained, and if it is larger than 1 or 0, the influence of fluorine atoms on chargeability will be greater,
Phenomena that are unfavorable in terms of image quality, such as white spots and image blur, occur.

The toner in which fluorine atoms are present in the surface layer as in the present invention is
In the suspension polymerization method, it cannot be obtained simply by adding a compound containing a fluorine atom to a monomer composition. According to the findings obtained by the present inventors, for example, fine powders of fluororesins such as polyvinylidene fluoride and Teflon, fluorine monomers such as perfluoroalkyl methacrylate, perfluoroalkyl ethylene, A toner obtained by adding a low molecular weight fluorine compound such as fluoroalkyl benzene or hexafluoropropylene dimer to a monomer solution of a toner composition and suspension polymerizing it in an aqueous medium containing a suspension stabilizer is Surprisingly, no fluorine atoms were detected on the surface by ESCA analysis. Therefore, even if a mere fluorine atom-containing compound is added, the cleaning properties of the toner can hardly be improved. On the other hand, internal addition of such a fluorine compound is undesirable because it significantly impairs the dispersion stability during suspension polymerization and causes a large amount of aggregates to form. This phenomenon is expected to occur because, during suspension polymerization, the fluorine compound dislikes external water and gathers inside the suspended particles, probably due to the extremely hydrophobic nature of the fluorine compound.

Based on this knowledge, the present inventors added PA'y, a fluorine-based surfactant having so-called surfactant ability, which has both a hydrophobic part containing a fluorine atom and a hydrophilic part containing a polar group. It has been found that such inconveniences can be solved and a toner in which fluorine atoms are concentrated on the particle surface can be obtained. It has also been found that this greatly improves the cleaning properties of toner obtained by suspension polymerization.

Further, in the present invention, the particle size variation coefficient y is defined by equation (1), and this value is a measure indicating the spread of the 1-ner particle system distribution on a number basis.

y - (S/x)X100 (%) ・
(1) Here, S represents the standard deviation (廁) of the number distribution of toner particle diameters, and X represents the number average particle diameter (/rm) of toner particles.

S and X in the formula are number 1 by Coulter counter.
It is necessary to show the value obtained when measuring the particle size of 0.000 particles or more, preferably 30,000 particles or more.

Here, the number-based scale was adopted because it emphasizes the distribution of fine powder parts more than the volume-based scale, and the distribution of fine powder toner is more important with respect to the problem to be solved by the present invention. This is the first time.

By the way, in the suspension polymerization method, when the toner is synthesized according to the usual recipe, there are many fine powder toners, and the particle size variation coefficient y on the number basis is 45% or more,
The above plants are shown.

As mentioned earlier, according to the findings obtained by the present inventors,
I-toner obtained by the suspension polymerization method has a spherical or table tennis-shaped shape with no sharp edges, and has various advantages such as good fluidity, but toner obtained by the normal pulverization method has various advantages. The adhesion force with carrier and photoreceptor (
van der wals force) is strong, and there is a strong tendency for the toner to be consumed starting with the larger particle size. For this reason, when copying a large number of sheets, the balance of the toner particle size distribution is lost, and furthermore, even if the toner has been developed on the photoconductor, it is difficult for toner with a relatively small particle size to separate from the photoconductor. happens. Therefore, when copying a large number of sheets, there may be problems such as deterioration of image quality, change in the amount of charge, decrease in transfer efficiency, and occurrence of cleaning failures.
Various undesirable situations occur.

In particular, it is important to minimize the amount of fine powder toner in terms of number of particles. However, it is almost impossible to obtain particles with an extremely narrow particle size distribution by suspension polymerization using mechanical dispersion, and if the particle size distribution is made unnecessarily narrow in this way, it may be difficult to obtain a particle with an extremely narrow particle size distribution. , bad effects such as loss of gradation also appear. Therefore, in suspension polymerization toners, there is an optimum particle size distribution range.

According to the findings of the present inventors, the coefficient of variation y expressed by the above general formula (]) in I-ner obtained by suspension polymerization has a particle size distribution that satisfies the following inequality (2). Toner is preferred.

47X x -0・5″≦y≦130X x−0・5
3...(2) Particularly preferably, y satisfies the following inequality (
The toner satisfies 3).

60X x −”53<y<125 X x−0・5
Specifically, the toner that satisfies the inequality (2) as shown in "3.(3)" has, for example, a number average particle diameter of 8. In the case of On toner, the particle size variation coefficient is in the range of 15.6 to 43.2%,
Number average particle size 10. On: 13.9-38.4%, number average particle size: 12. OIlm is a toner in the range of 12.6 to 34.8%, and has a narrower particle size distribution than a toner classified by a commonly used pulverization method.

If the range of inequality (2) is exceeded, the above-mentioned adverse phenomenon will occur in any case.

In the present invention, the preferred particle size range for the toner is a number average particle size of 5 to 25 capes.

The method for manufacturing the toner of the present invention will be specifically explained below.

In the present invention, a polymerizable monomer composition containing a charge control agent and a coloring agent is dispersed in an aqueous medium and then subjected to suspension polymerization. A continuous dispersion machine using cavitation, swirling flow or turbulence is used as a means for shearing and dividing the droplets of the polymerizable monomer composition into a particle size suitable for the toner in an aqueous medium. In this way, the toner of the present invention can be obtained.

In this way, by combining calcium phosphate, a fluorine-based surfactant, and a specific dispersion machine, the particle size distribution, especially on a number basis, is significantly improved, and the toner's adhesion is improved by concentrating fluorine atoms in the particle surface layer. is also significantly reduced.

That is, in the present invention, first, a colorant such as carbon black, a charge control agent, and other necessary toner property improvers are mixed and dispersed in a polymerizable monomer, this is used as an oil phase, and fluorine having surface-active ability is mixed and dispersed. Toner particles are produced by adding a surfactant to the oil phase or to an aqueous phase in which calcium phosphate and an anionic surfactant are uniformly dissolved, and using a continuous dispersion machine that utilizes cavitation, vortex flow, or turbulence to disperse toner. Disperse the oil phase droplets to a suitable particle size. The weight ratio of the oil phase to the aqueous phase is set in the range of 1:1 to 1:20 so that coalescence of particles does not occur during polymerization. A dispersion liquid in which the oil phase is uniformly dispersed in the water phase is mixed with a stirring device, a condenser, a thermometer,
The mixture is transferred to a polymerization reaction tank equipped with a nitrogen introduction tube, heated to a temperature at which the polymerization initiator decomposes (50 to 90'C), and polymerization is carried out under a nitrogen atmosphere. After the polymerization is completed, hydrochloric acid is added to eliminate the phosphate, the aqueous phase is removed by filtration, and after washing with water, water is removed by means such as spray drying or vacuum drying to produce 1 to 1.

Examples of the calcium phosphate used in the present invention include tertiary calcium phosphate (Caz (PO4) 2), hydroxyabatai I-(mca3(PO4)2/nca(Kano) 2), dibasic calcium phosphate, and calcium birophosphate. , hydroxyapatite and tertiary calcium phosphate are most preferred. These are used in an amount of 0.1 to 30% by weight, preferably 0.5 to 15% by weight, based on the oil phase.

The fluorine compound having surface-active ability in the present invention may contain a fluorinated alkyl group or a fluorinated alkenyl group and a polar group, and examples thereof include anionic, cationic, nonionic, and amphoteric compounds, and preferred polar Examples of groups include polyoxyethylene groups.

In the present invention, as a fluorine compound containing a polyoxyethylene group, Cl1F+70 (CH2C1+20)
+7tLC+5h70 (C1□CHzO):+. 1 (such as RrO(CH2CH20), lIt type (however,
n-1 to 200, R2 is a small number (both are fluorinated alkyl groups containing three fluorine atoms, the same applies hereinafter), C6F,, C1
1□ H2o (CHzCIl□0) 16H.

C+zFzsCHzCH20(C1l□CHzO)zs
RfCH2ClhO (CH2C1+20) such as H. H
Type (n = 1-200), C6F l zllc
H20(CH2CH20) sH,C4FeHCH2O
(CH2Cl 20) Rf-C11 such as I Oll
20 (C1hCI+20). ■Type (m-1~200
), Rr-CH2CtlCHzO(CHzCIl□0)
,,H etc. multivalent a0 (C112CH20) 1111 alcohol type (m, n-1 to 200), C9F+70
Unsaturated alcohol types such as (CHzCtl□o)zoll, ethylene oxide adducts of fluorine alcohols, CoF, 70(CH2C)120), CH3, C9F,
, 0(CH2CH20), II+3°CqF l 70
(Ctl.Cll20)lIC9F+7. C9F+
70 (CH2CH20).

(CII□Cll0), (CH2C1120), IC
R, O÷AO-) such as 9F+7 (m, n = CH3 1-200), Re, R,
An ether type represented by O÷AO-)-II-R, where →→T is a polyoxyalkylene group containing a polyoxyethylene group, C7F + 5cOo (CH2
CH2O)I, +1°C9F+5COO(CHzCHz
O) IICOC7F+s.

~200) etc. RfCOO+80 → fC00 to H9
+AO→TCORr, RvO-R-C00÷AO-)1
Fluorinated carboxylic acid ester represented by 1-11, CgF+J(CHzCHO)-(CIIzCthO)-
Block type CI (,
1 Later, C, F,, SO□N C8□CLO (Cll.

Examples include sulfonic acid amide compounds such as CIl□0) and 111.

In addition, CF3 (CFZ) bCFz 0
(C12CH20) nR-(CH2)r C11-(
CJ+□) p Ctl (C1l 2) − and other oligomer types, C112= CHCOO−(−(:H□C1l□Oh
CHzCII. 1,000 CFz hF (n-1 to 200).

Cll2 = CCOO+ C8□CLO+l C
Also included are monomer types such as fluoroalkyl-containing (meth)acrylates such as H2CH2+CF2)eF (n = 1 to 200). Moreover, the present invention is not limited to these, and any compound containing a fluorinated alkyl group and a polyoxyethylene group may be used.

In the present invention, these fluorosurfactants are usually used in an amount of 0.001 parts by weight per 100 parts by weight of the polymerizable monomer composition.
in the range of ~10 parts by weight, preferably 0805 to 3 parts by weight,
Particularly preferably, it is used in a range of 0.2 to 1 part by weight.

The toner of the present invention obtained by suspension polymerization in the presence of such a fluorine-based surfactant differs from a toner obtained simply by surface treatment with a fluorine compound, in that fluorine is present inside the surface layer as well. Therefore, even when washed with water, fluorine is not removed and the cleaning property is not only excellent, but there is no worry of spending on the carrier, and the product has excellent long-run performance.

In addition, anionic activators such as sodium dodecylhenzenesulfonate have a ratio of 0.01 to 1% relative to calcium phosphate.
It may be present in a range of 0% by weight.

In the present invention, a continuous dispersion machine using cavitation, swirling flow, or turbulence is used as a means for shearing and dividing the monomer composition in an aqueous medium to a particle size suitable for toner.

Cavitation is a method of applying strong shearing force using the ultrasonic waves generated when air bubbles are created behind a rotor or turbine blade due to a drop in pressure when it rotates vigorously in a liquid. Even if ultrasonic waves are used, those using an ultrasonic oscillator are not preferred because the particle size distribution becomes wide.

Further, even among those that utilize cavitation, hatch type ones are not preferred because the number of times of shearing becomes uneven during repeated shearing, resulting in a wide particle size distribution.

Examples of continuous dispersion machines using cavitation include continuous dispersion machines equipped with a stator and a rotor (generator or rotor-stator). Specific examples include Slasher (Mitsui Miike Manufacturing Co., Ltd.), T, high line mill milder (■ Ebara Corporation), T, homomic line flow, T, pipeline homomixer (Tokushu Kika Kogyo ■), etc., and other similar products Any method is fine.

On the other hand, examples of dispersion machines that utilize swirling flow or turbulent flow include methods in which the dispersion liquid is ejected at high speed from a nozzle or slit and a vortex is created by the force of the liquid, and a system in which the liquid flowing at high speed is installed in a tank. Examples include systems in which turbulence is caused by fixed vanes or the shape of the tank interior. Specific examples include Hydrochar (Gorlin Corporation),
Static mixer PSM (Pesotshold)
, T, the rotating whirlpool method such as Fiscalin (Tokushu Kika Kogyo ■), Sulzer mixer (Sulzer Brothers ■)
), line mixer type turbulent flow systems such as Hi Mixer (Higashi ■) and Noritake Static Mixer (Noritake ■). All of these are continuous processing methods.

In the present invention, as the polymerizable monomer, a polymerizable monomer having 3 to 25 carbon atoms can be used, such as styrene, p-
Chlorstyrene, p-methylstyrene, vinyl acetate, vinyl propionate, vinyl benzoate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 1
so-butyl acrylate, dodecyl acrylate-1.
n-octyl acrylate, methyl methacrylate-1.
Ethyl methacrylate, n-butyl methacrylate, 1
So-butyl methacrylate-1., diethylaminoethyl methacrylate, t-butylaminomethyl methacrylate, acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, and the like can be used alone or in combination.

Furthermore, in the present invention, if a polyfunctional monomer such as divinylhenzene, ethylene glycol dimethacrylate, trinotyrolpropane triacrylate, glycidyl methacrylate, or glycidyl acrylate is added to the above monomers as a crosslinking agent, a toner with even better durability can be obtained. Can be manufactured. The content of the polyfunctional monomer is preferably 0.05 to 20% by weight, preferably 0.5 to 5% by weight based on the monomer.

As the polymerization initiator, commonly used oil-soluble peroxide-based or ab-based initiators can be used. For example, hendyl peroxide, lauroyl peroxide, 2.2°-azobisisobutyronitrile, 2゜2゛-azobis-(2,4-dimethylvaleronitrile), orthochlorobenzoyl peroxide, orthomethoxyhendyl peroxide. Can be mentioned. These are used in an amount of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on the polymerizable monomer.

Further, the toner of the present invention may contain a low molecular weight olefin polymer known as a so-called mold release agent for the purpose of preventing offset, improving fluidity, improving fixing properties, etc.

It is preferable that this low molecular weight olefin polymer be present during monomer polymerization together with the colorant used in the present invention.

Examples of the low molecular weight olefin polymer used in the toner of the present invention include polyethylene, polypropylene, ethylene vinyl acetate copolymer, chlorinated polyethylene wax, polyamide, polyester, polyurethane, polyvinyl butyral, butadiene rubber, phenolic resin, epoxy resin, and rosin. Examples include modified resins, silicone oils, and silicone waxes.

The amount of the above-mentioned low molecular weight olefin polymer used is 1 to 20 parts by weight, preferably 3 to 15 parts by weight, per 100 parts by weight of the resin component of the toner, and if it is less than 1 part by weight, it may not have a sufficient offset prevention effect. Moreover, if the amount is 20 parts by weight or more, gelation may occur during polymerization, which is not preferable.

The charge control agent used in the present invention may be either positively chargeable or negatively chargeable, and any known charge control agent may be used in a normally used amount.

For example, if a negatively chargeable charge control agent such as an azo complex dye is used, a negatively chargeable I-toner can be obtained, and if a positively chargeable agent such as nigrosine is used, a positively chargeable toner can be obtained. , can be used as needed.

The colorant used in the present invention includes various carbon blanks manufactured by the thermal blank method, acetylene black method, channel black method, furnace blank method, lamp black method, etc. in the case of black toner, and copper phthalocyanine in the case of color toner. , monoazo series R (C
.

1. Pigment Red 5. C,1,Pigme
nt Orange 36. C.I.

Pigment Red 22), disazo pigment (C
, 1, Pigment Yellow 83), Anne I-
Laquinone pigment (C, 1, PigmentBlue 6
0), disazo dye (Solvent Red 19
), rhodamine dye (Solvent Red 49
) etc.

To form an image using the toner of the present invention, for example, by electrophotography, use a selenium photoreceptor, or zinc oxide, cadmium sulfide, cadmium selenide, cadmium selenide sulfate,
A photoreceptor in which a photosensitive layer containing an inorganic photoconductive material such as lead oxide or mercury sulfide dispersed in a binder resin is provided on a conductive support, or an organic photoconductive material such as anthracene or polyvinylcarbazole is used. A photoreceptor is used in which a photosensitive layer, which is optionally contained in a binder resin, is provided on a conductive support. The surface of the photosensitive layer of such a photoreceptor is entirely charged by corona discharge using, for example, a Coro1 Heron or Scorotron charger, and then imagewise exposed to light or the like to form an electrostatic charge image. Next, this electrostatic charge image is developed, for example, by a cascade method or a magnetic brush method, with a developer consisting of a mixture of the toner of the present invention and a glass beads or iron powder carrier to form a toner image. The images 1 to 3 are transferred onto the transfer paper by being pressed against the transfer paper under, for example, corona discharge. The toner image transferred onto the transfer paper is heated and fixed by a hot roll fixing device coated with a releasable fluorocarbon resin or silicone rubber.

[Effects of the Invention] As explained in detail above, the present invention provides a polymerizable monomer in which a colorant, a charge control agent, and other necessary toner property improvers are mixed and dispersed, and a polymerizable monomer mixed and dispersed with a calcium phosphate and a fluorine-based interface. The surface layer obtained by suspension polymerization in an aqueous medium in the presence of an activator contains a specific proportion of fluorine atoms, and the average particle size and particle size distribution on a number basis are determined by the suspension polymerization method. By obtaining a toner having a specific relationship, it is possible to obtain a toner for developing electrostatic images with poor image quality, which maintains poor developing properties, transfer properties, charging properties, and cleaning properties even during continuous copying of a large number of sheets. I was able to do that.

That is, according to the present invention, various defects caused by the shape of the toner obtained by the suspension polymerization method are covered, and the printing durability is improved by taking advantage of the simplicity of producing toner by the suspension polymerization method. We were able to provide an image with excellent image quality and image quality.

〔Example〕

Examples of the present invention are shown below, but the present invention is not limited thereto. Note that parts in the examples are parts by weight.

Example 1 85 parts of styrene, 1.15 parts of n-butyl acrylate, 0.5 part of divinylhenzene, 7 parts of carbon black (manufactured by Mitsubishi Kasei ■, #44), low molecular weight polyethylene (manufactured by Mitsui Petrochemical Industries ■, Mitsui Highwanx 210P) 2nd part,
After dispersing 1.5 parts of a charge control agent (manufactured by Hodogaya Chemical ■, Eisenspiron Black TRI+) in a ball mill for 8 hours, 2 parts of 2,2'-azobisisobutyronitrile was added, and the mixture was dispersed with phosphoric acid. 10 parts of tricalcium (manufactured by Katayama Chemical),
0.05 part of sodium dodecylhenzenesulfonate, and 0.2 part of fluoroalkenyl polyoxyethylene methyl ether represented by formula (4) (Ftergent F-250, manufactured by Neos), C9F, 0 (CH2CI+20) , C113 (n=5
~15) -=(4) 300 parts of water was added to the mixture and mixed and stirred.

Next, this mixed liquid was fed through Milder, a continuous dispersion machine using cavitation (manufactured by Ebara Corporation) at a feed rate of 25E/m.
in, passed twice at a rotation speed of 8000 rpm,
Suspended and dispersed. This suspension was placed in a separable flask equipped with a dehydration tube, a condenser, and a stirring device for 11 hours.
The polymerization reaction was carried out at 75° C. for 8 hours under a nitrogen atmosphere at a stirring speed of 0.00 rpm.

After the polymerization reaction, filter, wash with hydrochloric acid, wash with water, and heat at 40°C.
The mixture was dried under reduced pressure overnight.

When the obtained 1 hener was subjected to SCA measurement, the atomic ratio of fluorine/carbon on the surface was 0.095. In addition, the particle size and particle size distribution of the obtained toner were measured using a Coulter counter (TA-It type, aperture diameter 10100I).
When measured with J, the number average particle diameter X was 9.8 caps, and the standard deviation S of the number distribution of particle sizes was 3.0 caps. Formula (1)
The particle size variation coefficient y determined by the above equation was 30.6%, and this value satisfied inequality (2).

When this toner was used for image evaluation using a Sharp 5F8600, no cleaning defects were observed even during continuous copying, and clear images without fog were obtained. Further, the amount of charge did not change even after copying the second sheet, and a clear image without fogging was obtained, which was the same as the initial image. still,
The transfer efficiency during printing was good with an average of 87 to 92%.

Furthermore, no residual toner was observed on the photoreceptor.

Example 2 Styrene 87 parts, 2-ethylhexyl acrylate) 13
part, divinylbenzene 0.2 part, carbon black (manufactured by Columbian Carbon Japan, RAVEN2100)
7 parts, low molecular weight polyethylene (manufactured by Mitsui Petrochemical Industries ■, 210P) 2 parts, charge control agent (Orien L-Chemical ■)
Nonionic fluorinated argyl ester (Florado FC-43) represented by 2 parts and formula (5)
0, manufactured by Sumitomo 3M M) 1.5 parts Rf-COO (CIhCII.0). Co-Rf
…After dispersing (5) in a ball mill for 8 hours, 2,
To which 2 parts of 2-azubisisobutyroni-1-lyl was added, 10 parts of tricalcium phosphate (manufactured by Katayama Chemical Co., Ltd.), 0.05 part of sodium dodecylhenzensulfonate, and 30 parts of water were added.
0 part was added to the mixture and mixed and stirred.

Thereafter, suspension polymerization was carried out in exactly the same manner as in Example 1, and spherical l
・Nar particles were obtained.

When the particle size and particle size distribution of the obtained toner were measured in the same manner, the number average particle size was 11.17 parts m, and the standard deviation was 3.
0 parts were 1m. The particle size variation coefficient determined from equation (1) was 27.0%, which satisfied inequality (2). Further, when the obtained 1-ner was subjected to ESCA measurement, the fluorine/carbon atomic ratio on the surface was 0.375.

When image evaluation was performed using this toner in the same manner as in Example 1, no cleaning defects were observed and a clear image without fogging was obtained.

Furthermore, even after copying the second sheet, there were no cleaning defects at all, and a clear image that was the same as the initial image was obtained.

Example 3 In Example 1, instead of the continuous disperser Milder,
Dispersion was performed using a swirling vortex flow type hydrosher (manufactured by Gorlin Corporation). F)] The mixture of the monomer composition and the dispersant aqueous solution was heated to a pressure of 6 kg/c+f.
Pass through the hydrosher twice at l (gauge pressure),
Suspended and dispersed. Thereafter, a toner was synthesized according to Example 1.

The obtained toner had a number average particle diameter of 1.2.5 tIm, a standard deviation of 3.9 capes, a particle size variation coefficient of 31.0%, and the inequality (
2) was satisfied. Further, when ESCA measurement was performed, the atomic ratio of fluorine/carbon on the surface was 0.156.

When this toner was used for image evaluation using a Sharp 5F8600, no cleaning defects were observed even during continuous copying, and clear images without fog were obtained. Further, even after copying 30,000 copies, the amount of charge did not change, and a clear image without fogging was obtained, which was the same as the initial image.

Furthermore, no residual toner was observed on the photoreceptor.

Example 4 In Example 2, as the fluorine compound added to the monomer phase, a perfluoroalkyl represented by the following formula (6) was used instead of the nonionic fluorinated alkyl ester represented by the formula (5). Polyoxyethylene ethanol (Florado F
C-170G, manufactured by Sumitomo 3M ■) 2.1 parts CBF, 7C11□C1120 (CH2CH20), +
1 (n=10-20) (6) A toner was synthesized in exactly the same manner as in Example 2, except that (6) was used. Obtained 1
- The number average particle diameter of the toner is 9.2 廻, standard deviation 2.9 side,
The particle size variation coefficient was 31.5%, satisfying inequality (2). Further, the fluorine/carbon atomic ratio on the surface was 0.055 as determined by ESCA measurement.

When this toner was used for image evaluation using a Sharp 5F8600, no cleaning defects were observed even during continuous copying. Further, no residual toner was observed on the photoreceptor.

Example 5 In Example 1, instead of the milder, a turbulent flow type Sulzer mixer (manufactured by Sulzer Brothers ■) was used for dispersion. That is, the monomer composition was dispersed in water under conditions of a nominal diameter of 10.5 mm, 7 pieces of elm, and an average flow rate in the pipe of 2 m/sec. A toner was synthesized in the same manner as in Example 1 except for this.

The number average particle size of the obtained toner was 11.3ρ, the standard deviation was 3°8]1 m, and the particle size variation coefficient was 33.6%, satisfying inequality (2). Further, the fluorine/carbon atomic ratio on the surface was 0.112 as determined by ESCA measurement.

Using this toner, image evaluation was performed using a Sharp 5F8600, and no poor cleaning was observed on the image or photoreceptor, and the image was clear and free from fog even during continuous copying.

Comparative Example 1 In the same manner as in Example 1, except that no fluorine compound was added to the aqueous phase, 2) was synthesized.

The number average particle diameter of the obtained toner is 1], 7//In
The standard deviation was 4.69n. The particle size variation coefficient determined by equation (1) was 40.1%, and this toner did not satisfy inequality (2). In addition, fine l of 3.0p or less
・Na was 0.7% by volume.

When images were evaluated using a Sharp 5F8600 using this toner, poor cleaning occurred during continuous copying. Further, after approximately 5,000 copies were made, a decrease in the image and charge amount was observed.

Comparative Example 2 In Example 2, as a fluorine compound in the monomer phase,
Polyvinylidene fluoride fine powder (0,1 to I
I~Lunar was synthesized in exactly the same manner as in Example 2, except that 0.5 part (of diameter IIm) was added. During polymerization, the dispersibility was unstable and a large amount of aggregates were formed. The aggregates were removed using a Mensch sieve to obtain l.ner.

The obtained 1-ner had a number average particle size of 14.27/ITl
, the standard deviation was 6.91p, and the particle size variation coefficient y determined from equation (1) was 55.3%. This value is expressed by inequality (2)
The particle size distribution was wide.

When the image was evaluated using a Sharp 5F8600 using the toner No. 3, cleaning failures occurred severely during continuous copying, and the toner was also piled up on the photoreceptor, so the printing durability test was discontinued.

Claims (1)

[Claims] 1. The atomic ratio of fluorine/carbon in the particle surface layer is from 0.01 to
Contains fluorine atoms in the range of 1.0 and has a number average particle size of 5
~25 μm, and the particle size variation coefficient y y−(S/x)×100(%)...(1) [S is the standard deviation of the particle size number distribution (μm ), x is the number average particle diameter (μm)] is the following inequality (2) 47×x^-^0^. ＾5＾3≦y≦130×x＾-＾
0^. ^5^3... A toner for developing an electrostatic image, characterized by comprising spherical toner particles satisfying (2). 2. The toner for developing electrostatic images according to claim 1, wherein the toner particles are obtained by suspension polymerization. 3. In a method for producing a toner for developing electrostatic charge images by dispersing a polymerizable monomer composition containing a charge control agent and a colorant in an aqueous medium and then carrying out suspension polymerization, calcium phosphate is used as a suspension stabilizer. and cavitation as a means of shearing and dividing the droplets of the polymerizable monomer composition to a particle size suitable for the toner in an aqueous medium using a fluorine-based surfactant.
1. A method for producing toner for developing electrostatic images, characterized by using a continuous dispersion machine that utilizes swirling flow or turbulent flow.