JPH01235959A - Electrostatic charge image development toner and its production - Google Patents

Abstract

PURPOSE:To improve the cleaning property of the title toner by constituting the toner of a spherical toner particle having specified mean volume particle size and atomic ratio of a fluorine atom. to a carbon atom. in the surface layer of a toner particle, respectively. CONSTITUTION:The toner is constituted of the spherical toner particle which has the mean volume particle size of 2-20mum and contains the fluorine atom. in the surface layer of the toner particle in the atomic ratio of the fluorine atom. to the carbon atom. of a range of 0.01-1.000. The toner particle is produced by a suspension polymerization method. In this case, when the atomic ratio of the fluorine atom. to the carbon atom. is <=0.01, the sufficient cleaning property of the toner particle is not obtd., while when the ratio is >=1.0, adversely, the effect of the fluorine atom. to the electrostatic charging property of the toner particle becomes large, thereby taking place an undesirable phenomenon in image quality such as a white spot and an image unsharp, etc. Thus, in case that the toner particle is produced by the suspension polymerization, the faulty cleaning property of the toner particle caused by sticking force is improved, and the toner having the good flowability and the less change of the image quality which are the characteristic of the toner particle obtd. by the suspension polymerization is obtd.

Description

Detailed Description of the Invention [Field of Industrial Application] - The present invention relates to a dry toner for developing electrostatic images in electrophotography, electrostatic recording, and electrostatic printing, and a method for producing the same.

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 toner is charged by friction with a polarity opposite to that of the electrostatic latent image. A method using a two-component developer in which an electrostatic latent image is developed by applying a charge and 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.

[Prior art and problems to be solved by the invention] Conventionally,
To obtain these toners, thermoplastic resins are melted and
Coloring agents such as dyes and pigments, as well as magnetic substances, triboelectric charge control agents, anti-offset agents, lubricants, etc., are added to the mixture and mixed thoroughly. The mixture is cooled and solidified. After finely pulverizing the mixture, the desired particle size is obtained. A method of classification has been implemented to obtain .

However, the methods described above have various drawbacks. Firstly, many processes require equipment such as polymerization equipment for resin production, crosstalk equipment, crushers, classifiers, etc. The number of processes is large, and energy consumption is high, which is the cause of high production costs. It becomes. 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, in the grinding process, it is not possible to obtain only the appropriate fine powder particle size range to obtain clear, fog-free images;
There are drawbacks that lead to increased costs, such as the complexity of the process, such as fine powder and coarse powder being produced as by-products that must be classified and removed, and poor yields for obtaining the desired particle size range.

Fourth, the resulting powder has an angular and amorphous shape due to pulverization, and the fluidity of the fine powder is poor, and the image fogging is caused by the fine powder generated by re-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, the manufacturing process is simplified, and it can be said that the above-mentioned drawbacks have been improved.

The method for producing toner using suspension polymerization is to form a mixture of colorants, charge control agents, etc. in polymerizable monomers into a desired particle size using mechanical force in an aqueous medium in the presence of a dispersion stabilizer. This is a method in which the toner is atomized into particles, followed by polymerization, and a spherical toner is obtained.

Although the spherical toner compensates for the drawbacks of the pulverized toner as described above, it has been found that the spherical shape also causes new drawbacks. That is, although the fluidity is excellent, the problem is that the adhesion to the photoreceptor becomes strong. For this reason, in the cleaning process, the toner on the photoreceptor is not sufficiently removed by the cleaning blade, and a negative image or a positive image is formed on the photoreceptor during continuous copying, resulting in a phenomenon called cleaning failure.

In order to solve this problem, a method using a toner made of a mixture of spherical particles and irregularly shaped particles produced by pulverization has been proposed (Japanese Unexamined Patent Publication No. 123857/1983). The above-mentioned drawbacks associated with the pulverization method toner have been completely solved, and the mixing ratio of spherical particles and irregularly shaped particles is 10:100 to 60:100, which is a higher proportion of irregularly shaped particles, making it easier to suspend. The cost advantage of using the polymerization method is also 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 Laid-Open No. 61-6
No. 7039) has also been proposed, but this method has poor dispersion stability during polymerization, produces many aggregates, and can only obtain toner with a relatively wide particle size distribution, so classification is required. There are many problems, such as:

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 such as 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 surface of the photoreceptor, and fatty acid metal salt particles accumulate in the developer, resulting in changes in charging properties. There are problems such as.

An object of the present invention is to provide a toner for developing electrostatic images that uses a suspension polymerization method and has excellent cleaning properties, and a method for producing the same.

Another object of the present invention is to provide a toner for developing electrostatic images that does not deteriorate in image quality and always provides sharp images even when a large number of sheets are continuously copied, and a method for producing the toner.

Still another object of the present invention is to provide a toner that maintains the advantages of spherical toner, such as excellent fluidity and stiffness resistance, and overcomes the disadvantages thereof.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have diligently stacked the sides, and as a result, the present inventors have developed a spherical toner having a specific proportion of fluorine atoms in the particle surface layer, thereby improving cleaning efficiency. The inventors have discovered that the defects can be solved, and even when a large number of sheets are continuously copied, the image quality does not deteriorate and sharp images can be provided, leading to the present invention.

That is, in the present invention, the volume average particle diameter is 2 to 20I! m, and the fluorine/carbon atomic ratio is 0.0 in the surface layer of the particle.
The present invention relates to a toner for developing an electrostatic image, characterized in that it consists of spherical toner particles having fluorine atoms in the range of 1 to 1.00, and more specifically, the toner particles are obtained by a suspension polymerization method. The present invention relates to a toner for developing an electrostatic image, characterized in that: Further, the present invention provides that when a polymerizable monomer composition containing a charge control agent and a colorant is suspended polymerized in an aqueous medium, fluorine is added to the polymerizable monomer and/or in the aqueous medium. The present invention relates to a method for producing a toner for developing electrostatic images, characterized in that polymerization is carried out in the presence of a fluorine compound having a fluorinated alkyl group or a fluorinated alkenyl group and a polar group.

In the present invention, spherical toner particles include those having a ping-pong shape without an acute angle portion. That is, in addition to a perfectly spherical toner, toners having rounded uneven portions such as an elliptical shape, a cocoon shape, a potato rod shape, etc. may be used.

Since the toner of the present invention itself has excellent cleaning properties, it is possible to prevent cleaning defects that could not be prevented by the usual method of externally adding a cleaning aid to the toner or developer. There is no need to worry about filming on the photoreceptor or accumulation in the developer.

The present invention will be specifically described below.

In the present invention, the atomic ratio of fluorine/carbon in the surface layer of toner particles is determined by ESCA (electron 5pectr
oscopy for chemical analysis
is) determined by surface analysis. That is, the Pls electron spectrum and CI! obtained by ESCA measurement of the target toner. This value is the ratio of the respective peak areas in the electron spectrum. 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 surface layer has a fluorine/carbon atomic ratio of 0. Old ~ 1.0, preferably 0.02 ~ 0
．． 5, more preferably in the range of 0.05 to 0.3, fluorine atoms are present. The presence of fluorine atoms in the surface layer improves the lubricity of the toner surface and reduces the adhesion force with the photoreceptor, thereby making it possible to prevent poor cleaning.

If the fluorine/carbon atomic ratio is less than 0.01, sufficient leaning properties cannot be obtained, and if it is greater than 1 or 0, the influence of fluorine on charging properties becomes large, resulting in white spots and images. Unfavorable phenomena such as blurring occur in terms of image quality.

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 knowledge obtained by the present inventors, for example, fine powders of fluororesins such as polyvinylidene fluoride and Teflon, fluorine thread monomers such as perfluoroalkyl methacrylate, perfluoroalkyl ethylene, A toner obtained by adding a low molecular weight fluorine compound such as perfluoroalkylbenzene 1, hexafluoropropylene dimer, etc. to a monomer solution of a toner composition and suspension polymerizing it in an aqueous medium containing a suspension stabilizer. Surprisingly, no fluorine was detected on the surface by ESCA analysis. Therefore, even if a simple fluorine-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.

In view of this knowledge, the present inventors have developed a material that has both a hydrophobic part containing a fluorine atom and a hydrophilic part containing a polar group.
It has been found that by adding a fluorine compound having so-called surfactant ability, such inconveniences can be overcome 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 l/ner obtained by suspension polymerization.

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 of preferable polar groups include a hydroxyl group, a polyoxyethylene group, a carboxylic acid group, and a polar group. Examples include a group and its alkali metal salt or ammonium salt, a sulfonic acid group and its alkali metal salt or ammonium salt, a phosphoric acid group and its alkali metal salt or ammonium salt, an amino group and its quaternary ammonium salt, hetain, and the like.

In the present invention, the fluorine compound having a hydroxyl group includes:
C6F+30)1. C8F+70H9C+zFzsO
II, Cl3F: 1708°C+J'++CIIzC
H20H, CaF+7CIIzC1120tl, Cl
2F25C112CI+2011゜Cl eF:+vc
B2cHzOH, CF, +CHFCFzCII□OH,
II(CzF4)zclI201t.

H(C2F4) Straight chain or branched fluorine alcohol represented by lCH20H, etc., C6F13C82CIlCH20H, CeFI7CHz
Examples include poly-OHH alcohols such as CHCHzOH, alcohols containing unsaturated groups such as C9+70tl and C6FIIOH, and sulfonic acid amide type alcohols such as (,F,5O2N(CIl.CH20H)2).

Further, in the present invention, examples of the fluorine compound containing a polyoxyethylene group include C6F+30. (CH2CH20) I? H,Cl8F3
．． RfO(CH,C
H20) llH type (n = 1-200) (However,
1? , is a fluorinated alkyl group or fluorinated alkenyl group containing at least 3 fluorine atoms (the same applies hereinafter), C6F+
aC82CII20(CHzCIIzO)+J, Cl
RyCIlzCHzO, ((:HzCH20), l
II type (n = 1 to 200), C6F1211CH20 (CH2CH20) SH, C4
R such as F81(CH,0(CH2CH20),,)1
v-CHzO (CH2CH20) meter type (, m = 1
~200), Rf-CH2CH2H20(CH2CH2
0). Polyhydric alcohol-0 such as 11 (CIICI (20)
, +1 type (m+ n= 1 to 200), CqH+tO(
CHtCHzO)z. Ethylene oxide adducts of fluorine alcohols, such as unsaturated alcohol types such as 11, C9F+70 (CHzCHJ)fiCHs, c9p1
7o (ct+2cl12o), cl+3°C6F+30
(CH2CH20)-CqFt7゜C9F+70(CH
2CH20)+1(CH2CH2), (CI2CH20
), IC9F+7 (m or more, n = 1 to 200), etc. Rf (1 + AO output R,,! 1,0 ＾ 0 + ether type represented by R (however, +AO + T is a polyoxyethylene group-containing polyoxyethylene group) oxyalkylene group), C7F l5cOO (CH2CII□O), lH, C1
F, 5COO (CII□C11□0) fiCOC7F
+ 5° etc. R, COO←AO well H, R, COO 1000 AO → lower C0Rr.

R,0-R-COO←AO)-fluorinated carboxylic acid ester represented by I (where R is a divalent hydrocarbon group),
C8F+70(CH2CH2)lI(CH2CH20)
Block types with other alkylene oxides such as l, H (m, n = 1 to 200) CI + 3, C, H + □ CeF + tsOJcl (zcl IzO (C, H2C
1lzO), sulfonic acid amide types such as H (n=1 to 200), and the like.

In addition, CF3(CF2)6CP2 0(CH2
CH20)rlR(CH2). C1l”(C112)P
CI+, (CHz)-r-(n-1~200, o
, p, q=5~1ooo >, etc., CH2CHCOO-(-CH2CH2O7CH2CH2
(CFz +8F.

. I+', (''1~200) CH2=CCOO+CH2CH20-+Te1l□C0
Monomer type products such as fluoroalkyl-containing (meth)acrylates such as °→CFz)sF(n-1 to 200) are also included. Furthermore, any compound containing a fluorinated alkyl group or a fluorinated alkenyl group and a polyoxyethylene group can be used.

In the present invention, compounds containing a carboxylic acid group include:
CF3(CF2)6COOH,CF+(CFz)ecO
OIl.

RrCHzCHzOCOCH=CHCOOII, Ry
CIlzCIIzOCOCIlzCthCOOH etc., and Na of these carboxylic acids.

Alkali metal salts such as K and ammonium salts can also be used.

In the present invention, examples of the fluorine compound containing a sulfonic acid group include C6F13SO:+11. C6F13S
O311゜CsF+t, o(CHz)ssOJ, Cz
F230(CHz)4SO311°++ etc., and Na of these sulfonic acids.

ρ alkali metal salts such as K and ammonium salts can also be used.

In the present invention, examples of the fluorinated metal having a phosphate group include RtCJIzCH20PO(OH)2, etc.
Alkali metal salts such as Na and K, and ammonium salts can also be used.

Furthermore, in the present invention, examples of the fluorine compound having an amino group include S and the like, and those having a hetain structure reacted with quaternary ammonium salts thereof, monohalogenated acetic acid, etc. can also be used.

Above, specific examples of fluorine compounds that are preferably used in the present invention have been given, but among these, fluorine compounds that can be dissolved and distributed to some extent in the polymerizable monomers used in the present invention are more preferably used. Compounds are preferred. That is,
In the present invention, it is necessary that the surface layer of the obtained toner contains fluorine, but if even a small amount of fluorine compound dissolves into the monomer, fluorine will be contained in the surface layer of the toner particles. This is convenient for concentrating and retaining. If the hydrophilicity is so strong that there is almost no solubility for the monomer, the fluorine may be completely washed away from the surface by subsequent treatments such as water washing, or even if a small amount remains, there is not enough fluorine on the particle surface. It is also possible that fluorine is not present.

Among the above-mentioned fluorine compounds, those that can be dissolved in monomers include those that have a hydroxyl group, a polyoxyethylene group, a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, and an amino group, and can form salts. Of these, acid type and amine type are preferred.

Furthermore, among these fluorine compounds, fluorine compounds containing polyoxyethylene groups, so-called nonionic fluorine compounds, can freely adjust their polyoxyethylene chain length and adjust the balance between hydrophilicity and lipophilicity. It is particularly preferably used because it is easy to use.

In the present invention, these fluorine compounds are usually used in an amount of 0.00 parts by weight per 100 parts by weight of the polymerizable monomer composition.
It is used in a range of 1 to 10 parts by weight, preferably in a range of 0.05 to 3 parts by weight, particularly preferably 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 compound differs from a toner obtained by simply surface-treating the surface with a fluorine compound because fluorine is present inside the surface layer. Even if this process is carried out, fluorine is not removed, so not only does it have excellent cleaning properties, but it also has excellent long run properties without worrying about spending on the rear.

In the present invention, toners having a volume average particle size of 2 to 20 caps are practically preferred. Here, the volume average particle size is a value measured with a particle size measuring device such as a Coulter counter.

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

First, a colorant such as carbon black, a charge control agent, wax, and other toner property improvers are added to the polymerizable monomer, and a fluorine compound according to the present invention is further added.
These are mixed and dispersed. A polymerization initiator is added to the thus obtained toner composition to form an oil phase, and suspension polymerization is carried out in an aqueous medium in the presence of a dispersion stabilizer.

The fluorine compound of the present invention may be added to the polymerizable monomer as described above, or may be added to the aqueous medium. In either case, the fluorine compound gathers near the particle surface and is concentrated, so there is no problem.

An example of a suspension polymerization method is to add a dispersion of the oil phase to an aqueous phase in which a dispersion stabilizer such as a water-soluble polymer compound or a poorly water-soluble inorganic compound is uniformly dissolved or dispersed, and then add the dispersion liquid of the oil phase to the aqueous phase in which a dispersion stabilizer such as a water-soluble polymer compound or a poorly water-soluble inorganic compound is uniformly dissolved or dispersed. It is dispersed into oil droplets of 2 to 20 tones using a dispersing means such as the above.

The weight ratio of the oil phase to the aqueous phase is in the range of 1:2 to 1:10, and is set in such a range that coalescence of particles does not occur during polymerization. A dispersion liquid in which oil cake is uniformly dispersed in an aqueous phase is transferred to a polymerization reaction tank equipped with a stirring device, a condenser, a thermometer, a nitrogen inlet pipe, and a dehydration pipe, and the temperature is raised to a temperature sufficient to absorb the polymerization initiator. Polymerization is carried out under a nitrogen atmosphere. After polymerization, the aqueous phase is removed by filtration, and treated with water or dilute acid as necessary.

In this way, the toner of the present invention is obtained.

As the colorant used in the present invention, in the case of black toner, various carbon blacks manufactured by the thermal black method, acetylene black method, channel black method, furnace black method, lamp black method, etc., and in the case of color toner, copper Phthalocyanine, monoazo pigment (
C.

1. P'igment Red 5. C,1,Pig
ment Orange 36. C.

1, 'P'igment Red 2'2), disazo pigment (C, 1, Pigment Yellow
83), anthraquinone pigment (C.

1, Pigment'BIue 60), disazo dye 1sc+IventRecl 19)', and rhodamine dye (Solvent Red 49).

The charge control agent used in the present invention may be either positively chargeable or negatively chargeable. For example, when a negatively chargeable charge control agent such as an azo complex dye is used, it may be negatively chargeable. When a positively chargeable charge control agent such as nigrosine is used in the toner, a positively chargeable toner can be obtained and can be used as desired. The amount of the charge control agent added is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the polymerizable monomer.

As the polymerizable monomer used in the present invention, polymerizable monomers having 3 to 25 carbon atoms can be used, such as EVA, styrene, p-chlorostyrene, p-methylstyrene, vinyl acetate, and vinyl propionate. , vinyl benzoate, methyl acrylate, ethyl acrylate, n-butyl acrylate, 1so-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, n-octyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 1so- Butyl methacrylate, diethylaminoethyl methacrylate, t-butylaminomethyl methacrylate, acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, and the like may be used alone or in combination of two or more.

Furthermore, in the present invention, by adding polyfunctional monomers such as divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, glycidyl methacrylate, and glycidyl acrylate to the above polymerizable monomers as a crosslinking agent, durability can be further improved. can produce excellent toner. The content of the polyfunctional monomer is 0.05 to 2 parts by weight per 100 parts by weight of the polymerizable monomer.
The amount is preferably 0 parts by weight, and more preferably 0.1 to 5 parts by weight. .

In the present invention, commonly used oil-soluble peroxide-based or azo-based initiators can be used as the polymerization initiator. For example, benzoyl peroxide, lauroyl peroxide, 2.
Examples include 2'-azobisisobutyronitrile, 2,2''-azobis-(2,4-dimethylvaleronitrile), orthochlorohenzoyl peroxide, and orthomethoxyhenzoyl peroxide. It is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the polymer.

Dispersion stabilizers used in the present invention include water-soluble polymer compounds such as gelatin, starch, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl pyrrolidone, polyvinyl alkyl ether, and polyvinyl alcohol, barium sulfate, calcium sulfate, barium carbonate,
Examples include poorly water-soluble inorganic compounds such as calcium carbonate, magnesium carbonate, and calcium phosphate. The amount of these dispersion stabilizers used is preferably 0.5 to 20 parts by weight, more preferably 2 to 20 parts by weight, based on 100 parts by weight of the polymerizable monomer.
It is 10 parts by weight.

Further, the toner obtained in 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.

This low molecular weight olefin polymer is preferably dispersed in the monomer together with the colorant used in the present invention.

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

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

Furthermore, the toner obtained in the present invention can contain a magnetic material and can also be used as a -component l.toner. When a magnetic substance is contained, it is preferable to disperse it in a polymerizable monomer and use it, similarly to a coloring agent. The content of the magnetic material is 20 parts by weight per 100 parts by weight of the polymerizable monomer.
-200 parts by weight is preferred, more preferably 50-15 parts by weight.
It is 0 parts by weight.

To form an image using the toner obtained in the present invention, for example, by electrophotography, a selenium photoreceptor, or a selenium photoreceptor such as zinc oxide, cadmium sulfide, cadmium selenide, cadmium sulfide, lead oxide, mercury sulfide, etc. A photoreceptor in which a photosensitive layer containing an inorganic photoconductive material dispersed in a binder resin is provided on a conductive support, or an organic photoconductive material such as anthracene or polyvinylcarbazole is contained in the binder resin as necessary. A photoreceptor having a photosensitive layer formed on a conductive support is used. The surface of the photosensitive layer of such a photoreceptor is entirely charged by corona discharge using, for example, a corotron 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 obtained in the present invention and a glass beads or iron powder carrier to form a toner image. This toner image is 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 heat-fixed by a hot roll fixing device coated with a fluororesin or silicone rubber that has releasable properties.

〔Effect of the invention〕

As explained in detail above, the present invention uses a polymerizable monomer in which a colorant, a charge control agent, and other necessary toner quality agents are mixed and dispersed. The present invention relates to a toner containing a specific proportion of fluorine atoms in a surface layer obtained by suspension polymerization in an aqueous medium in the presence of a fluorine compound having a polar group and a fluorine compound.

As a result, the present inventors have succeeded in significantly improving the poor cleaning properties of spherical toner usually obtained by suspension polymerization due to its adhesive force, while improving the fluidity which is a characteristic of the conventional suspension polymerization method. It has been possible to provide a 1-ner which has the properties of good image quality and little change in image quality even during continuous copying of a large number of sheets.

〔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.

85 parts of styrene, 15 parts of n-butyl acrylate, 0.5 parts of divinylhenzene, carbon black (Mitsubishi Kasei ■
1144) 7 parts, low molecular weight polyethylene (Mitsui Petrochemical Industries Ltd., Mitsui Hiwax 210P) 2 parts,
After dispersing 1.5 parts of a charge control agent (manufactured by Hodogaya Kagaku ■, Eisens Viron Black TR) in a ball mill for 8 hours, 10 parts of 2,2'-azobisiso7-butylonitrile calcium (manufactured by Katayama Kagaku ■) was dispersed in a ball mill for 8 hours. , 0.05 part of sodium dodecylhenzenesulfonate, and 2(1)C,F
+70 (CIlzCHzO), lCl13 (n= 5
~15) Fluoroalkenyl polyoxyethylene methyl ether (phtergent F-2) represented by (1)
In addition to a mixture of 0.2 parts (manufactured by Neos) and 300 parts of water, mix 6 with a TK homomixer (manufactured by Tokushu Kika Kogyo ■).
The mixture was stirred at 000 rpm for 3 minutes.

This suspension was subjected to a polymerization reaction at 75°C for 8 hours under a nitrogen atmosphere at a stirring speed of 100 rpm in a separable flask equipped with a dehydration tube, a condenser, and a stirring device.

After the polymerization reaction, filter, wash with hydrochloric acid, wash with water, and heat at 40°C.
By drying under reduced pressure overnight, spherical toner particles having a volume average particle size of 410.7 gn were obtained.

When the obtained toner was subjected to ESCA measurement, the fluorine/carbon atomic ratio on the surface was (1.095).

Using this toner, image evaluation was performed using a Sharp SF8600, and no cleaning defects were observed even during continuous copying, and clear images without capri 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.

Furthermore, no residual toner was observed on the photoreceptor.

87 parts of styrene, 13 parts of 2-ethylhexyl acrylate
part, divinylbenzene 0.2 part, carbon black (manufactured by Columbian Carbon Japan, RAVEN2100)
7 parts, low molecular weight polyethylene (manufactured by Mitsui Petrochemical Corporation, 210P), 2 parts, charge control agent (manufactured by Orient Chemical Company, S-34), and 2 (2) RrCOO (CH2
CHzO) llCORr (2) Nonionic fluorinated alkyl ester (Florard FC
After dispersing 1.5 parts of L430 (manufactured by Jujutsu 3M ■) in a ball mill for 8 hours, 2 parts of 2,2'-azobisisobutyronitrile was added, and 10 parts of tricalcium phosphate (manufactured by Katayama Chemical ■) was dispersed in a ball mill for 8 hours. part, thorium dodecylbenzenesulfonate o. In addition to a mixture of 5 parts of
Stir for 3 minutes at rpm. This suspension was subjected to suspension polymerization in exactly the same manner as in Example 1. This results in a volume average particle size of 12
．． Two capes of spherical toner particles were obtained.

When the obtained toner was subjected to ESCASC, 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, no cleaning defects were observed.
A clear image that was the same as the initial image was observed.

In Example 1, as the fluorine compound added to the aqueous phase, the nonionic fluorine compound represented by the formula (1) was replaced with a perfluorine compound represented by the following formula (3) (% formula %) (3) A toner of the present invention was obtained in exactly the same manner as in Example 1, except that 0.3 part of fluoroalkyl polyoxyethylene ethanol (Florard FC-170C, manufactured by Sumitomo 3M ■) was used.

The obtained toner had a volume average particle size of 12.5I! m, ES
When CASC 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 l/ner was observed on the photoreceptor.

In Example 2, the fluorine compound added to the monomer phase was substituted with the nonionic fluorinated alkyl ester represented by the formula (2) by the following formula (4) % formula % A toner was synthesized in exactly the same manner as in Example 2, except that 2.1 parts of fluorine alcohol (manufactured by Hoechst) was used. The volume average particle diameter of the obtained toner was 9.5, and the surface fluorine/carbon atomic ratio according to ESCASC was 0.
．． It was 055.

When images were evaluated using a Sharp 5P8600 using this toner, no cleaning defects were observed even during continuous copying. Further, no residual toner was observed on the photoreceptor.

In Example 1, the nonionic fluorine compound represented by formula (1) as the fluorine compound added to the aqueous phase was replaced by a perfluoro compound represented by the following formula (5). A toner was synthesized in the same manner as in Example 1 except for using 0.5 part of alkanesulfonic acid (manufactured by Hoechst).

The volume average particle size of the obtained toner was 11.3, and E
The atomic ratio of fluorine/carbon on the surface according to SCASC- is 0.1
It was 12.

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

In Example 2, as the fluorine compound added to the monomer phase, the following formula (6) % formula % (6) was used instead of the nonionic fluorinated alkyl ester represented by formula (2). A toner was synthesized according to Example 2 except for using 0.8 part of a sulfonic acid amide type product represented by (Megafac F-528, manufactured by Dainippon Ink ■). The volume average particle size of the obtained toner was 11.5 tones, and ESCASC-
The atomic ratio of fluorine/carbon on the surface was 0.334.

In Example 2, the fluorine compound added to the monomer phase was the following formula (7)% formula% (7) instead of the nonionic fluorinated alkyl ester represented by formula (2). A toner was synthesized according to Example 2 except for using 1.2 parts of the fluorinated carboxylic acid shown below (manufactured by Hoechst). The volume average particle size of the obtained toner was 12.7n, and the ES
The atomic ratio of fluorine/carbon on the surface according to CA measurement is 0.2
It was 16.

A toner was synthesized in exactly the same manner as in Example 1 except that no fluorine compound was added to the aqueous phase. The obtained toner had a volume average particle size of 11.5 μm and was spherical.

When this toner was used for image evaluation using a Sharp 5F-8600, poor cleaning occurred during continuous copying.

In the control plate and Example 2, polyvinylidene fluoride fine powder (0,1
A toner was synthesized in the same manner as in Example 2, except that 0.5 part of the toner (with a diameter of ~1 voice) was added. During polymerization, the dispersibility was unstable and a large amount of aggregates were produced.

Aggregates were removed using a mesh sieve, and the volume average particle size was 14.
I got 2 tiles of toner. When this toner was subjected to ESCA measurement, no fluorine atoms were detected on the toner surface.

When this toner was used to evaluate images with Sharp S and F8600, poor cleaning occurred during continuous copying, and the toner was also piled up on the photoreceptor, so the printing durability test was discontinued.

Reference reference 1 In Example 2, as a fluorine compound in the monomer phase,
In place of the nonionic fluorinated alkyl ester represented by formula (2), 0 parts of fluoroalkyl methacrylate represented by the following formula (8)% formula % was added, and other than this, the same procedure as in Example 2 was used. A toner was synthesized in the same manner. The volume average particle diameter of the obtained toner was 11.5-, which was appropriate, but no fluorine was detected on the surface by ESCA measurement.

Therefore, we conducted a similar evaluation using this toner on a Sharp 5F8600, but the cleaning failure was still severe.
A large amount of toner also adhered to the photoreceptor.

Take 50 parts of the toner obtained in Comparative Example 1 and add 100 parts of the toner.
The mixture was redispersed in water to form a slurry.

To this water slurry was added 0.3 parts of a fluorine compound represented by the following formula (9), dissolved in 30 parts of isopropyl alcohol. The slurry mixture was stirred at a temperature of 30°C for 30 minutes, then filtered and dried.

When the toner obtained by surface treatment with a fluorine compound was subjected to ESCA measurement, the fluorine/carbon atomic ratio was 0. ．． It was 37B. However, when such surface-treated toner was repeatedly washed with surfactant aqueous solution and ion-exchanged water and re-dried, ESC
In the A measurement, the fluorine/carbon atomic ratio was extremely small at 0.003. Junior 37
, As2 It was found that in the toner whose surface was treated with a fluorine compound, the fluorine compound was simply adsorbed on the surface, and no fluorine atoms existed inside the surface layer of the toner.

Image evaluation was performed using a Sharp 5F8600 using toner obtained by surface treatment with a fluorine compound, and the result was approximately 30
A cleaning failure occurred when 00 sheets were continuously copied. When the carrier was separated from the developer after copying and the surface was analyzed, fluorine was detected, indicating that toner was spent.

Applicant's agent Kaoru Furutani

Claims (1)

[Scope of Claims] 1. Spherical toner particles having a volume average particle diameter of 2 to 20 μm and having fluorine atoms in the surface layer of the particles with a fluorine/carbon atomic ratio in the range of 0.01 to 1.00. A toner for developing an electrostatic image, characterized by comprising: 2. The toner for developing electrostatic images according to claim 1, wherein the toner particles are obtained by suspension polymerization. 3. When suspension polymerizing a polymerizable monomer composition containing a charge control agent and a colorant in an aqueous medium, a fluorinated alkyl group or A method for producing a toner for developing an electrostatic image, characterized in that polymerization is carried out in the presence of a fluorine compound having a fluorinated alkenyl group and a polar group. 4. The fluorine compound has a fluorinated alkyl group or a fluorinated alkenyl group and a polar group selected from a hydroxyl group, a polyoxyethylene group, a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, and an amino group. The method for producing a toner for developing an electrostatic image according to claim 3. 5. The method for producing a toner for developing an electrostatic image according to claim 3, wherein the fluorine compound is a fluorine-based nonionic surfactant containing a fluorinated alkyl group or a fluorinated alkenyl group and a polyoxyethylene group.