JP3200362B2 - Electrostatic image developing toner and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image, which is used for developing an electrostatic image and is suitable for fixing under heat and pressure, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, US Pat.
Many methods are known as described in Japanese Patent Publication No. 297,691, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-24748. In general, a photoconductive substance is used to form an electrostatic image on a photoreceptor by various means, and then the electrostatic image is developed using toner to form a toner image. After a toner image is transferred to a transfer material as described above, the toner image is fixed by heating, pressure, heating pressure, solvent vapor or the like to obtain a copy image or print image.

Conventionally, various methods have been proposed as a method of developing using toner or a method of fixing a toner image, and a method suitable for each image forming process is adopted. Conventionally, a toner used for these purposes is generally prepared by melting and mixing a coloring material composed of a dye and / or a pigment in a thermoplastic resin and uniformly dispersing the same, and then using a pulverizer or a classifier to obtain a toner having a desired particle size. Has been manufactured.

Although these manufacturing methods can produce fairly good toners, they have certain limitations. For example, the colorant-dispersed resin composition must be sufficiently brittle and capable of being pulverized with economically feasible manufacturing equipment. However,
When the colorant-dispersed resin composition is made brittle, the particle size range of the particles formed when the material is actually pulverized at high speed is likely to be widened, and in particular, there is a problem that relatively large particles are included therein.

Further, such a brittle material is susceptible to further pulverization or pulverization when used for development. In this method, it is difficult to uniformly disperse solid fine particles such as a colorant in a resin, and depending on the degree of dispersion, increase in fog, decrease in image density, color mixing of toner, or transparency. Cause a decrease in Exposure of the colorant to the fracture surface of the toner particles may cause fluctuations in the development characteristics of the toner.

On the other hand, in order to overcome the problems of the toner produced by these pulverization methods, Japanese Patent Publication Nos. 36-10231, 42-10799, and 51 have been disclosed.
No. -14895 proposes a method for producing a toner by a suspension polymerization method. In the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator, and further, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition. After that, the monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer using a suitable stirrer, and the polymerizable monomer is polymerized to obtain toner particles having a desired particle size.

According to this method, since a pulverizing step is not included, brittleness is not required for the toner particles, a soft material can be used, and no colorant is exposed on the surface of the toner particles. And has a uniform triboelectric charging property. Since the classifying step can be omitted, cost saving effects such as energy saving, shortening of manufacturing time, and improving process yield are great.

However, even in such a manufacturing method, when the toner particles are finely divided, the colorant is easily exposed to the surface layer of the toner particles, and the influence of the colorant is easily generated. And the development characteristics tend to fluctuate.

[0009] The phenomenon is particularly remarkable when copying or printing is continued under high humidity. Conventionally, in order to achieve uniform charging, for example, JP-A-62-73277 and JP-A-3-35660 have proposed methods of coating the surface layer of toner particles with a resin.

However, in these methods, although the influence of the colorant can be certainly prevented because the coating layer is thick, it is difficult to contain components having charge controllability. In addition, there has been a problem that the absolute value of the charge amount of the toner becomes small.

For this purpose, a method of coating the surface of the toner particles in more stages has been proposed in Japanese Patent Application Laid-Open Nos. 64-62666, 64-63035 and 58-57105. , The manufacturing process is complicated,
It is disadvantageous in terms of cost. In order to improve such problems, a method of depositing a charge control agent on the surface of toner particles has been proposed.
JP-A-61-273558, JP-A-5-1344
No. 37, for example. However, in this method, in consideration of the durability of the toner that occurs when copying or printing is repeated, the charge control agent detaches from the toner surface and causes a problem in the durability characteristics.

In recent years, digital full-color copying machines and printers have been marketed, and high quality images having excellent color reproducibility without color unevenness as well as resolution and gradation can be obtained.

In a digital full-color copying machine or a full-color printer, a color image original is represented by B (blue), G
(Green) and R (red) filters, the electrostatic image having a dot diameter of 20 to 70 μm corresponding to the original image is formed into Y (yellow), M (magenta), C (cyan) and Developing is performed by using the subtractive color mixing action using the respective color toners of Bk (black). Compared with a black-and-white copying machine, it is necessary to transfer a larger amount of toner from a photoreceptor to a transfer material, and it is required to reduce the size of toner particles corresponding to fine dots in order to achieve high image quality.

As the speed and full color of printers and copiers increase in the future, further improvement in low-temperature fixability becomes an important factor, and from this point, toner particles having a sharp particle size distribution and a fine particle size can be relatively easily formed. Are preferred. For the toner mounted on a full-color copying machine or a full-color printer, it is necessary that each color toner is sufficiently mixed in the fixing process, and at this time, the color reproducibility is improved and the transparency of an overhead projector (hereinafter referred to as OHP) image is improved. is important. Further, the color toner is preferably a low molecular weight resin having better melting property than the black toner.

As a releasing agent for the black toner, a wax having a relatively high crystallinity represented by a polyethylene wax or a polypropylene wax is used for the purpose of improving high-temperature offset resistance during fixing. However, in a full-color toner, the transparency of an image is reduced when output to an OHP because of the high crystallinity of the wax.

For this purpose, an anti-offset liquid such as silicone oil is applied to the heat fixing roller without adding a release agent as a component of the color toner, thereby improving the high-temperature offset resistance. I have.

[0017] For this reason, the transfer material after fixing is not preferable because extra silicone oil adheres to the surface thereof, which may cause discomfort to the user when handling it.

For this reason, studies have been made on oilless fixing toners in which a large amount of a low softening point substance is contained in toner particles. There is a long-awaited demand for toners having good properties.

As a method for solving such problems, Japanese Patent Application Laid-Open No. 230073/1990 discloses a color image fixing method using a polymerized toner containing a low-softening substance having releasability. . It is likely that the toner development characteristics during the durability test are reduced, which is considered to be caused by seepage of the low softening point substance onto the toner particle surface.

For the purpose of preventing the colorant from being exposed to the surface of the toner particles and preventing the low softening point substance from seeping out, a polar polymer or a polar copolymer may be added to the polymerizable monomer composition. And JP-A-61-35457.
JP-A-6-317925 discloses that a hydrophilic outer shell material is provided on the surface of toner particles.

However, even if this method is used, since the material forming the outer shell is hydrophilic, the developing properties under high humidity are poor and the durability is poor. Further, in order to improve fixing inhibition by the outer shell material, the glass transition point of the resin of the core material is set to 10 to 50 ° C.
, The transfer material easily winds around the fixing roller during fixing.

Accordingly, a toner produced by a polymerization method,
In particular, there is a long-awaited need for a color toner that successfully solves the problems caused by both the developing characteristics and the fixing characteristics.

[0023]

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

An object of the present invention is to provide a toner for developing an electrostatic image in which the function separation between the inside, the inner layer and the outer layer of the toner particles is improved.

An object of the present invention is to provide a toner for developing an electrostatic charge image which has excellent triboelectricity and has stable triboelectricity even in various environments.

An object of the present invention is to provide a toner for developing an electrostatic charge image capable of forming a high quality toner image with high image density and little fog.

An object of the present invention is to provide a toner for developing an electrostatic image which is less likely to scatter in the image forming apparatus.

An object of the present invention is to provide a toner for developing an electrostatic image, which is excellent in durability of a large number of sheets.

An object of the present invention is to provide a toner for developing an electrostatic image, which is formed of color toner particles having excellent color mixing properties and good light transmission.

An object of the present invention is to provide a manufacturing method for producing the above toner.

[0031]

According to the present invention, there is provided a toner for developing an electrostatic charge image having toner particles containing at least a binder resin and a colorant, wherein the toner particles form at least the inside thereof. A material having a low softening point, an inner layer covering the interior, and an upper layer covering the interior and the inner layer, wherein the interior, the inner layer, and the upper layer are ruthenium tetroxide and tetroxide; A toner for developing an electrostatic image, wherein the inner layer is formed of a styrene polymer, a styrene-acryl copolymer, or a styrene-methacryl copolymer. About.

Further, the present invention provides a polymerizable monomer composition containing at least a polymerizable monomer, a colorant, a substance having a low softening point, a resin having a polar group, and a polymerization initiator. The polymer composition is dispersed in an aqueous medium to form particles of the polymerizable monomer composition, the polymerizable monomer in the particles is polymerized to generate toner particles, and the heat absorption of the low softening point substance is reduced. The aqueous medium is heated to a temperature higher than the peak temperature by 5 ° C. or more and higher than the glass transition temperature of the resin having a polar group by 5 ° C. or more, and then the aqueous medium is cooled at a cooling rate of 2 ° C. or less per minute.
C. or lower, and a method for producing a toner in which toner particles are filtered from an aqueous medium to form toner particles, wherein the toner particles have at least a low softening point substance forming the inside and a coating on the inside. An inner layer, and an inner layer covering the inner layer and the inner layer, wherein the inner layer, the inner layer, and the upper layer are made of a material that can be distinguished by ruthenium tetroxide and osmium tetroxide dying method. Wherein the inner layer is formed of a styrene polymer, a styrene-acrylic copolymer or a styrene-methacrylic copolymer.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, there is provided a method for improving the durability, covering a minute disturbance of the chargeability on the surface of toner particles with a polymer as in the prior art, and using a charge control agent as a toner. Rather than preventing the particles from adhering to the particle surface, the inside made of a low softening point material is first covered with an inner layer, and the inner layer is further covered with an upper layer. The toner particles were embedded with an epoxy resin or the like, and further, the cross section was stained with ruthenium tetroxide and osmium tetroxide, and when the section was observed later using a transmission electron microscope, the inner, inner layer, By separating the materials that can form the upper layer from each other, the functional separation of each part is improved, and the colorant, the charge control agent, and the low softening point substance are included in the toner particles. As a result, excellent developing characteristics and fixing characteristics are exhibited.

Next, the present invention will be described in detail with reference to preferred embodiments.

The thickness of the upper layer of the toner particles of the present invention is determined by a transmission electron microscope according to the following measurement method.
When it can be confirmed as a layer having a thickness of from 01 to 0.5 μm, the effect of the present invention can be exhibited without excess or deficiency, which is preferable. If the thickness of the upper layer is less than 0.01 μm, the coloring agent and the low softening point compound cannot be sufficiently covered, and if it exceeds 0.5 μm, the fixability tends to decrease. A more preferred thickness is from 0.05 to 0.4 μm.

In the present invention, as a specific method for measuring the cross-sectional morphology of the toner particles, after sufficiently dispersing the toner particles in a cold-setting epoxy resin, the mixture is left to cure at a temperature of 40 ° C. for 2 days. The obtained cured product was cut out from a flaky sample using a microtome equipped with diamond teeth, and ruthenium tetroxide and osmium tetroxide were used in combination, and dyed due to a slight difference in crystallinity.
The difference is confirmed using a transmission electron microscope (TEM). FIG. 1 shows a schematic diagram of a typical example.

The toner particles of the present invention are preferably those produced by a polymerization method such as a suspension polymerization method, an emulsion polymerization method, an interfacial polymerization method, a dispersion polymerization method, or an association polymerization method produced in an aqueous medium. In particular, it is necessary to form the upper layer with a material that can be distinguished from the inner or central part or the inner layer by staining with ruthenium tetroxide and osmium tetroxide.

As such a material for the upper layer, a resin having a polar group and having a glass transition point of 55 to 80 ° C. and an acid value of 1 to 35, more preferably 5 to 35 is suitable. The resin having a polar group is dissolved in the polymerizable monomer composition, and then, in a step of granulating the polymerizable monomer composition into droplets of toner particles in an aqueous medium, the toner particles and The droplets gather near the surface of the resulting droplet particles, and the upper layer of the toner particles is preferably formed by the subsequent polymerization step and slow cooling step.

Therefore, when the transition point of the resin glass having a polar group is lower than 55 ° C., the strength of the upper layer of the toner is reduced, and the transferability and durability are deteriorated. On the other hand, if the temperature is higher than 80 ° C., the strength of the upper layer becomes too high, and it is easy to hinder the action and effect of the charge control agent inside the toner particles from reaching the toner particle surface. Tends to fluctuate. Further, the acid value of the resin having a polar group is 1
If the acid value is less than 35, the strength of the formed upper layer is reduced, transferability and durability are reduced. If the acid value is more than 35, the colorant and the compound having a low softening point tend to precipitate on the surface of the toner particles, which is not preferable.

The measurement of the glass transition point of the resin is performed by ASTM D
3418-8, Perkin Elmer DSC
Perform using -7. The correction of the device detection unit uses the melting points of indium and zinc, and the correction of the calorific value uses the heat of fusion of indium. For the sample, an aluminum pan was used, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./m.
in. Measure with The acid value of the resin is measured according to JIS-K-
0070 is performed.

The amount of the resin having a polar group is preferably 1 to 100 parts by weight of the binder resin in the toner particles.
20 parts by weight, more preferably 2.5 to 15 parts by weight. If the amount is less than 1 part by weight, the function as the upper layer of the toner particles is reduced. If the amount is more than 20 parts by weight, the upper layer formed on the toner particles becomes excessive, and the charging stability of the toner tends to be reduced.

Among the resins having a polar group, a polyester resin or a derivative thereof is preferable. The composition of a typical polyester resin is as follows.

As the alcohol component of the polyester resin, ethylene glycol, propylene glycol, butanediol, diethylene glycol, triethylene glycol, pentanediol, hexanediol, neohentyl glycol, hydrogenated bisphenol A, or the following formula (I) And the diols represented by the following formula (II).

[0044]

[Outside 1] (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

[0045]

[Outside 2]

Examples of the divalent carboxylic acid containing 50 mol% or more of the total acid component include benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and phthalic anhydride or anhydrides thereof; succinic acid, adipic acid, sebacic acid And alkyldicarboxylic acids such as azelaic acid or anhydrides thereof. Polyhydric alcohols such as glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolak phenolic resins; and polycarboxylic acids such as trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and anhydrides thereof.

The particularly preferred alcohol component of the polyester resin is a bisphenol derivative represented by the above formula (I). Examples of the acid component include phthalic acid, terephthalic acid, isophthalic acid, trimellitic acid and anhydrides thereof. Can be

Examples of the polymerizable monomer that can be used to produce the toner particles of the present invention include vinyl polymerizable monomers. For example, styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m
-Methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert
-Butylstyrene, pn-hexylstyrene, pn
Styrene derivatives such as octyl, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene;
Methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-
Butyl acrylate, iso-butyl acrylate, t
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, diethyl phosphate ethyl acrylate, dibutyl phosphate Acrylic polymerizable monomers such as fate ethyl acrylate and 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate,
n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n
-Methacrylic polymerizable monomers such as amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid Acid esters;
Vinyl acetate, vinyl propionate, vinyl benzoate,
Vinyl esters such as vinyl butyrate, vinyl benzoate and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether;
And vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

The inner layer is composed of a vinyl polymer formed from these vinyl polymerizable monomers. Among these vinyl polymerizable monomers, a styrene polymer, a styrene-acrylic copolymer, or a styrene-methacrylic copolymer is used in order to efficiently cover the low softening point substance forming the internal or central part. preferable.

In particular, among these polymers, polymers or copolymers having a glass transition point of more than 50 ° C. and less than 100 ° C. are preferable. When the glass transition point becomes 50 ° or less,
At the time of fixing, the adhesive force to a fixing unit such as a fixing roller is increased, so that the transfer material carrying the toner image is difficult to be separated from the fixing unit, and the problem of wrapping around the fixing roller is likely to occur. Further, the strength of the entire toner particles is reduced, and the transferability and the developing characteristics are liable to be deteriorated during a multi-durability test. When the obtained fixed images are superposed for a long time, a problem that the images stick to each other due to a low glass transition point may occur. On the other hand, when the glass transition point is 100 ° C. or higher, the problem of poor fixing is likely to occur.

When these polymers or copolymers have a main peak in a molecular weight range of 10,000 to 50,000 in gel permeation chromatography (GPC), a large amount of low softening existing in the center is obtained. Excellent in encapsulating point substances. When the main peak of the molecular weight of the polymer or the copolymer constituting the inner layer is less than 10,000, the interaction between the molecular chains of the polymer or the copolymer becomes weak, and the low softening point constituting the inside or the central portion is weakened. The material cannot be sufficiently coated, and the low softening point material is likely to cause a decrease in developing characteristics. On the other hand, when the main peak of the polymer or the copolymer exceeds 50,000, the interaction of the molecular chains of the polymer or the copolymer becomes too strong, so that the substance having a low softening point at the time of heat and pressure fixing of the toner is obtained. If the toner does not seep into the toner particles sufficiently and the fixing temperature is relatively low, poor fixing and low-temperature offset phenomenon are likely to occur.

Further, the molecular weight is 15,000 to 40,000.
When a styrene polymer or a styrene copolymer having a main peak is used, the toner particles have sufficient strength and exhibit excellent triboelectric charging characteristics, and thus exhibit extremely excellent developing characteristics. Due to the sufficient strength of the toner particles, deterioration of the toner hardly occurs even after the durability test, and stable transferability and development characteristics can be maintained.

[0053] The molecular weight of the polymer or copolymer is measured by gel permeation chromatography (GPC). As a specific GPC measurement method, a toner is extracted in advance with toluene using a Soxhlet extractor for 20 hours, and then the toluene is distilled off with a rotary evaporator to obtain an extract. Further, if necessary, a polymer or copolymer is obtained. Is sufficiently washed with an organic solvent that cannot be dissolved (for example, chloroform or the like), and the solution obtained by dissolving the residue in tetrahydrofuran (THF) is filtered through a membrane filter for solvent resistance having a pore diameter of 0.3 μm. Sample
Waters 150C was used, and the column configuration was Showa Denko A-801, 802, 803, 804, 805,
806 and 807 are connected, and the molecular weight distribution is measured using a standard polystyrene resin calibration curve.

The low-softening substance as a material constituting the inner or central part of the present invention includes, as in the measurement of the glass transition point, an endothermic main part in a measured DSC endothermic curve in accordance with ASTM D3418-8. The peak value is 55
More preferably, a compound having a value of 60 to 90 ° C. is preferable, and particularly, a tangent departure temperature of a DSC curve is 4
Compounds having a low softening point of 0 ° C. or higher are more preferred. 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. Further, when the tangent departure temperature is lower than 40 ° C., the strength of the toner particles is reduced, and the development characteristics during the durability test are likely 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.
FIG. 2 shows a schematic diagram of a DSC endothermic curve of the low softening point substance.
Further, the low-softening point substance has a half width of the endothermic main peak of 1%.
Those having a sharp melt property within 0 ° C, more preferably within 5 ° C are good.

As the low softening point substance, a solid wax which is solid at room temperature is preferable. Specifically, paraffin wax,
Examples thereof include polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax, and derivatives such as graft compounds and block compounds. An ester wax having at least one long-chain ester moiety having 10 or more carbon atoms represented by the following general structural formula is particularly preferable because it has an effect on high-temperature offset resistance without inhibiting transparency of OHP. 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).

[0057]

[Outside 3] (Where a and b each represent an integer of 0 to 4, a + b is 4, R ₁ and R ₂ each represent an organic group having 1 to 40 carbon atoms, and the carbon number of R ₁ and R ₂ is A group having a difference of 10 or more is shown, n and m each represent an integer of 0 to 15, and n and m do not become 0 at the same time.

[0058]

[Outside 4] (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, and n and m
Represents an integer of 0 to 15, and n and m are not simultaneously 0. )

[0059]

[Outside 5] (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.) 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 may be the same or different from each other) .) General structural formula of ester wax: R ₁ COO (CH ₂ ) _n OOCR 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
May have the same or different carbon numbers. General formula of ester wax: R ₁ OOC (CH ₂ ) _n COOR ₂ (wherein, R ₁ and R ₂ each 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
May have the same or different carbon numbers. )

The ester wax preferably used in the present invention has a melt viscosity measured at 100 ° C. of 1 to 50 mPa.
X sec is preferable. The melt viscosity of the ester wax is, for example, a visco tester VT5 manufactured by HAAKE.
Measure using 00. When the melt viscosity is less than 1 mPa × sec, the effect of preventing high-temperature offset decreases,
If it exceeds 50 mPa · s, the wax does not easily ooze out at the time of fixing, and the low-temperature fixability decreases.

The molecular weight of the low softening point substance is preferably one having a weight average molecular weight (Mw) of 300 to 1,500. If it is less than 300, the low softening point substance is likely to be exposed to the surface of the toner particles, and if it exceeds 1,500, the low-temperature fixability deteriorates. Particularly, those having a range of 400 to 1,250 are preferable. Furthermore, the ratio of weight average molecular weight / number average molecular weight (M
(w / Mn) is 1.5 or less, DS of low softening point substance
The maximum peak of the C endothermic curve becomes sharper, the mechanical strength of the toner particles at room temperature is improved, and particularly excellent toner characteristics showing sharp melting characteristics at the time of fixing are obtained.

The molecular weight of the low softening point substance is measured by GPC under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150C (Waters) Column: GMH-HT 30 cm double (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1. 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-Houw
It is calculated by converting into polyethylene using a conversion formula derived from the ink viscosity formula.

Specific examples of the low softening point substance include the following compounds.

(1) CH ₃ (CH ₂ ) ₂₀ COO (CH ₂ ) ₂₁ CH ₃ (2) CH ₃ (CH ₂ ) ₁₇ COO (CH ₂ ) ₉ OOC
(CH ₂ ) ₁₇ CH ₃ (3) CH ₃ (CH ₂ ) ₁₇ OOC (CH ₂ ) ₁₈ COO (CH ₂
) ₁₇ CH ₃

In recent years, the necessity of a full-color double-sided image has been increasing. When forming a double-sided image, the toner image on the transfer material formed first on the front surface is used for forming the image next on the rear surface. There is also a possibility that the toner may pass through the heating section of the fixing device again, and it is necessary to sufficiently consider the high-temperature offset resistance of the fixed image of the toner at that time. Therefore, in the present invention, it is preferable to include a large amount of the low softening point substance in the toner particles. Specifically, it is preferable to add a low softening point substance to the toner particles in an amount of 5 to 30% by weight.
Addition of less than 5% by weight lowers the hot offset resistance,
Further, when the double-sided image is fixed, the image on the back side may show an offset phenomenon. When the amount is more than 30% by weight, coalescence of toner particles tends to occur during granulation in the production by the polymerization method, and a toner having a wide particle size distribution is easily generated.

In the present invention, it is preferable to add a charge control agent to the toner particles in order to control the chargeability of the toner.

As these charge control agents, among the known ones, those having little polymerization inhibitory property and almost no water phase transfer property are preferred. For example, a nigrosine dye as a positive charge control agent,
Examples include triphenylmethane dyes, quaternary ammonium salts, guanidine derivatives, imidazole derivatives, amine compounds, and the like. Examples of the negative charge control agent include a metal-containing salicylic acid copolymer, a metal-containing monoazo dye compound, a urea derivative, a styrene-acrylic acid copolymer, and a styrene-methacrylic acid copolymer.

The addition amount of these charge control agents is preferably 0.1 to 10% by weight of the binder resin or polymer monomer.

The polymerization initiator used for producing toner particles by the polymerization method includes 2,2'-azobis- (2,4-
Divaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-
Azo or diazo polymerization initiators such as 2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyloxy carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide And peroxide-based polymerization initiators such as These polymerization initiators are preferably added in an amount of 0.5 to 20% by weight of the polymerizable monomer, and may be used alone or in combination.

In order to control the molecular weight of the binder resin of the toner particles, a crosslinking agent or a chain transfer agent may be added.
The preferred addition amount is 0.001 to 0.001 of the polymerizable monomer.
15% by weight.

In the aqueous dispersion medium, as a dispersion stabilizer of the particles of the polymerizable monomer composition, for example, tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, water Examples include fine powders of inorganic compounds such as calcium oxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina.

Examples of the dispersion stabilizer include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, polyacrylic acid and its salts, polymethacrylic acid and its salts, and organic substances such as starch. Compounds may be used. It is preferable to use 0.2 to 20 parts by weight of these dispersion stabilizers based on 100 parts by weight of the polymerizable monomer.

When an inorganic compound is used as the dispersion stabilizer, a commercially available one may be used as it is, but the inorganic compound may be formed in an aqueous dispersion medium in order to obtain fine particles. For example, in the case of calcium phosphate, an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride may be mixed under high stirring.

For fine dispersion of the dispersion stabilizer, a surfactant may be used in an amount of 0.001 to 0.1 part by weight based on 100 parts by weight of the polymer monomer. This is to promote the initial action of the dispersion stabilizer. Specific examples include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium octylate, sodium stearate, calcium oleate, and the like.

As the coloring agent used in the present invention, known coloring agents can be used.

For example, black pigments include carbon black, aniline black, non-magnetic ferrite, magnetite and the like.

Examples of the yellow pigment include yellow iron oxide, Navels Yellow, Naphthol Yellow S, Hanser Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake and the like. No.

Examples of the orange pigment include permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indaslen brilliant orange RK, indaslen brilliant orange GK and the like.

Examples of red pigments include Bengala, Permanent Red 4R, Risor Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red C, Lake D, Brilliant Carmine 6B, Brillant Carmine 3B, Eoxin Lake, Rhodamine Lake B, Alizarin Lake. And the like.

Examples of blue pigments include alkali blue lake, Victoria blue lake, phthalocyanine blue,
Metal-free phthalocyanine blue, phthalocyanine blue partial chloride, Fast Sky Blue, Indaslen Blue BG, and the like can be given.

Examples of purple pigments include Fast Violet B and Methyl Violet Lake.

Examples of green pigments include Pigment Green B, Malachite Green Lake, Final Yellow Green G, and the like. As white pigments, zinc white,
Examples include titanium oxide, antimony white, and zinc sulfide.

These colorants can be used singly or as a mixture, or in the form of a solid solution.

The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner. The amount of the colorant added is 100
It is preferable to use 1 to 20 parts by weight based on parts by weight. When a magnetic material is used as the black colorant, it is preferable to use 30 to 150 parts by weight with respect to 100 parts by weight of the resin, unlike other colorants.

When the toner for developing an electrostatic latent image of the present invention is used as a translucent color toner, pigments of various types and colors as described below can be used.

For example, yellow pigments such as C.I. I. 103
16 (Naphthol Yellow S), C.I. I. 11710
(Hanza Yellow 10G), C.I. I. 11660 (Hanza Yellow 5G), C.I. I. 11670 (Hanza Yellow 3G), C.I. I. 11680 (Hanza Yellow G),
C. I. 11730 (Hanza Yellow GR), C.I. I.
11735 (Hanza Yellow A), C.I. I. 11740
8 (Hanza Yellow RN), C.I. I. 12710 (Hanza Yellow R), C.I. I. 12720 (Pigment Yellow L), C.I. I. 21090 (benzidine yellow), C.I. I. 21095 (benzidine yellow G),
C. I. 21100 (benzidine yellow GR), C.I.
I. 20040 (Permanent Yellow NCR), C.I.
I. 21220 (Vulcan Fast Yellow 5), C.I.
I. 21135 (Vulcan Fast Yellow R).

As the red pigment, C.I. I. 12055
(Stalin I), C.I. I. 12075 (bread-magent orange), C.I. I. 12175 (Resole Fast Orange 3GL), C.I. I. 12305 (Permanent Orange GTR), C.I. I. 11725 (Hanza Yellow 3R), C.I. I. 21165 (Vulcan Fast Orange GG), C.I. I. 21110 (benzidine orange G), C.I. I. 12120 (permanent red 4
R), C.I. I. 1270 (Para Red), C.I. I. 12
085 (Fire Red), C.I. I. 12315 (Brilliant Fast Scarlet), C.I. I. 1231
0 (permanent red F2R), C.I. I. 12335
(Permanent red F4R), C.I. I. 12440
(Permanent red FRL), C.I. I. 12460
(Permanent red FRLL), C.I. I. 12420
(Permanent red F4RH), C.I. I. 12450
(Light Fast Red Toner B), C.I. I. 124
90 (permanent carmine FB), C.I. I. 1585
0 (Brilliant Carmine 6B) and the like.

As the blue pigment, C.I. I. 74100
(Metal-free phthalocyanine blue), C.I. I. 74160
(Phthalocyanine blue), C.I. I. 74180 (fast sky blue) and the like.

In the present invention, in order to produce toner particles using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant. If necessary, the surface of the colorant may be subjected to a hydrophobic treatment with a substance that does not inhibit polymerization to modify the surface. In particular, attention must be paid to the use of dyes and carbon blacks because many of them have polymerization inhibitory properties.

As a preferable method for treating the dye, there is a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance. The obtained colored polymer is added to the polymerizable monomer composition. The carbon black may be treated with a substance (for example, organosiloxane or the like) that reacts with the surface functional group of the carbon black, in addition to the same treatment as the above dye.

When the toner of the present invention is used as a magnetic toner, a magnetic powder may be contained therein. As such a magnetic powder, a substance which is magnetized in a magnetic field is used, for example, iron, cobalt, powder of a ferromagnetic metal such as nickel, or magnetite, powder of a sulfurous iron oxide such as ferrite. There is.

In order to obtain toner particles by the polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the magnetic material, and if necessary, surface modification (for example, by using a substance having no polymerization inhibition). (Hydrophobic treatment) is preferred.

During the production process of the toner particles, the temperature may be raised in the latter half of the polymerization reaction. Further, in order to remove unreacted polymerizable monomers or by-products which cause odor at the time of fixing the toner, the reaction is carried out. The aqueous medium may be partially distilled off from the reaction system in the latter half or after the end of the polymerization reaction. After the completion of the reaction, the generated toner particles are collected by washing, filtration, and dried.

In the suspension polymerization method, it is preferable to use 300 to 3,000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the polymerizable monomer composition.

In order to further clarify the functional separation between the inner or central portion of the toner particles, the inner layer and the outer layer, the inner layer is higher than the endothermic main peak temperature of the DSC endothermic curve of the low softening point substance constituting the inner or central portion. The toner particles are held for 60 minutes or more (preferably 90 to 600 minutes) at a temperature higher than the glass transition temperature of the constituting polymer or copolymer and higher than the glass transition point of the polar group-containing resin constituting the outer layer. Heat treatment, and then 2 ° C. or less per minute (preferably,
It is preferable to cool slowly at a slow cooling rate (1.5 to 0.25 ° C. per minute).

Therefore, the endothermic main peak temperature of the low softening point substance is measured in advance, the glass transition temperature of the resin having a polar group is measured, and the polymer or copolymer formed from the composition and composition ratio of the polymerizable monomer is measured. It is better to calculate the theoretical glass transition temperature of the polymer.

The heat treatment temperature is at least 5 ° C. higher than the endothermic main peak temperature of the low softening point substance (preferably 5 to 20 ° C.).
Higher than the glass transition point of the resin having a polar group added to the polymerizable monomer composition (preferably 5 to 20 ° C. higher), and the polymer or copolymer to be synthesized is synthesized. 5 ° C. or higher than the theoretical glass transition point of (preferably,
(7.5 to 30 ° C. higher).

In order to further improve the image quality, it is preferable that the toner has a weight average diameter of 4 to 8 μm and a variation coefficient A in the number distribution is 35% or less. Weight average diameter is 4μm
When the toner has a weight average diameter of 8 μm or more, fusion to the surface of the photoreceptor or the transfer material is liable to occur. When the coefficient of variation in the number distribution of toner exceeds 35%, the tendency is further enhanced.

Next, the present invention will be described more specifically with reference to examples and comparative examples.

Example 1 710 parts by weight of ion-exchanged water and 850 parts by weight of a 0.1 mol / L aqueous solution of Na ₃ PO ₄ were added to a four-necked container, and were mixed with a high-speed stirrer TK-Homomixer. 0
While stirring at 00 rpm, the temperature was kept at 60 ° C. 68 parts by weight of 1.0 mol / liter-CaCl ₂ aqueous solution was gradually added thereto, and a fine hardly water-soluble dispersion stabilizer Ca ₃ (PO _3
4 ) An aqueous dispersion medium containing ₂ was prepared.

Styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 13 parts by weight Polyester resin 7 parts by weight (terephthalic acid-propylene oxide-modified bisphenol A-ethylene oxide-modified bisphenol A; acid value 13; glass transition point 60 ° C. Mw 12000, Mn 5700) Negative charge control agent (chromium compound of dialkyl salicylic acid) 1 part by weight Low softening point compound [ester wax (3)] 25 parts by weight (Endothermic main peak temperature in DSC 81 ° C., half width 3 ° C., Tangent departure temperature 50 ° C; Mw = 700, Mw / Mn = 1.2; melt viscosity at 100 ° C 20 cPa · s)

The theoretical Tg of a styrene-n-butyl acrylate copolymer synthesized from styrene and n-butyl acrylate is 59 ° C.

The above mixture was dispersed for 3 hours using an attritor, and then 4 parts by weight of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was added. The mixture was put into an aqueous dispersion medium, and granulated for 5 minutes while maintaining the rotation speed of the stirrer at 10,000 rpm. Thereafter, the high-speed stirring device was changed to a propeller-type stirrer, the internal temperature was raised to 70 ° C., and the mixture was reacted for 10 hours with slow stirring to obtain polymer particles (toner particles).

Next, the inside of the container was heated to 90 ° C.
For 1 minute and then gradually at a cooling rate of 1 ° C./minute.
Cooled to 0 ° C. Dilute hydrochloric acid was added to the vessel to remove the dispersion stabilizer. Further, the resultant was filtered, washed and dried to obtain electrically insulating cyan toner particles having a weight average diameter of 6.4 μm and a coefficient of variation in number distribution of 29%.

FIG. 1 is a schematic view of a tomographic photograph obtained by staining the obtained cyan toner particles with osmium tetroxide and ruthenium tetroxide, and confirming them with a TEM. The ester wax, which is a low softening point substance, constitutes the central part and the central part is GPC
Has a molecular weight of 23,000 and a glass transition point (T
g. ) Covered an inner layer composed of a styrene-n-butyl acryl copolymer at 62 ° C., and covered an upper layer composed of a polyester resin of about 0.15 μm.

The obtained cyan toner particles were externally added with 2% by weight of hydrophobic titanium oxide fine particles to obtain a cyan toner having excellent fluidity. 6 parts by weight of the obtained cyan toner and 94 parts by weight of a ferrite carrier coated with a silicone resin having an average particle diameter of 40 μm were mixed to prepare a two-component developer.

The above two-component developer was used to copy an image in a cyan color mode under normal temperature and normal humidity and at normal temperature and low humidity using a modified machine obtained by modifying a digital full color copying machine CLC-700 having a commercially available OPC photosensitive member. Was evaluated. Under normal temperature and normal humidity, the transfer efficiency from the drum photoreceptor surface is initially 97
%, And an image having a high image density without transfer defects such as hollow spots was obtained. Although a durability test was performed on 50,000 sheets, the transfer efficiency always maintained a value close to 95%, there was no significant change in image quality between the initial stage and after the durability test, and the toner was fused to the photosensitive drum and each member. No occurrence was observed. Even under normal temperature and low humidity, the result under almost normal temperature and normal humidity was reproduced. The results are shown in Tables 3 and 4.

Examples 2 to 7 and Comparative Examples 1 to 5 Toner particles were produced in the same manner as in Example 1 except that the materials used were as shown in Table 1, and then a two-component developer was prepared. And an evaluation test. The results are shown in Tables 2, 3 and 4.

Comparative Example 6 The polymerization was carried out at a temperature of 70 ° C., and then the temperature was raised to 90 ° C.
Toner particles were produced in the same manner as in Example 1 except that the temperature was reduced from 90 ° C. to 30 ° C. at a cooling rate of 5 ° C./min.
Next, a two-component developer was prepared and an evaluation test was performed. The results are shown in Tables 2, 3 and 4.

[0112]

[Table 1]

[0113]

[Table 2]

[0114]

[Table 3]

[0115]

[Table 4]

Measurement of Image Density Using a Macbeth densitometer, a solid image portion was measured using an SPI complementary color filter.

Measurement of Transfer Efficiency The transfer efficiency was evaluated at the beginning and after the end of the continuous image formation of 50,000 sheets, respectively. In the cyan unit, a cyan toner image formed on the photosensitive drum was sampled with a transparent adhesive tape, and the image density (D ₁ ) was measured with a Macbeth densitometer. Next, a cyan toner image is formed again on the photosensitive drum, the cyan toner image is transferred to a recording material, and the cyan toner image transferred onto the recording material is collected with a transparent adhesive tape, and its image density (D ₂ ) Was similarly measured. It was calculated as follows from the obtained image densities (D ₁ ) and (D ₂ ).

Transfer efficiency (%) = (D ₂ / D ₁ ) × 100

[0119] whether normal temperature and low humidity (20 ℃, RH 5%) of the fusion of the toner of the OPC photosensitive member surface observation of the presence or absence of toner fusion of the OPC photosensitive member surface visually after in environments 50,000-sheet running test did. In addition, draw a halftone image,
It was determined whether or not an image defect occurred due to fusion of the toner by comparing with a standard sample.

Evaluation of low-temperature fixability and high-temperature offset resistance
Method Transfer paper (80 g / m ² ) using a modified full-color digital copying machine (CLC-700, manufactured by Canon)
An unfixed toner image was formed thereon. Then, the unfixed toner image was heated and pressed on the transfer paper without oil by a heating / pressurizing roller external fixing device having no oil application means and capable of adjusting the fixing temperature, thereby forming a fixed image on the transfer paper.

The fixing roller (heating roller) surface of the external fixing device is formed of a fluororesin, and the pressure roller surface is also formed of a fluororesin.
120 to 2 at the fixing speed of 120 mm / sec
A fixing test was performed in a temperature range of 40 ° C. at 5 ° C. intervals.

The low-temperature fixability was such that the fixed image was fixed at 50 g / cm ^2.
The load of the paper is Sylbon paper [Lenz Cleaning P
aper “dasper (R)” (Ozu Pap
erCo. (Ltd)], and the temperature at which the density reduction rate before and after the rubbing was less than 10% was taken as the fixing temperature, and used for the evaluation of low-temperature fixability.

Rank of low-temperature fixability: A: 120 ° C. ≦ fixing start temperature ≦ 140 ° C .: 140 ° C. <fixing start temperature ≦ 160 ° C. O: 160 ° C. <fixing start temperature ≦ 180 ° C. X: fixing start temperature <180 C. On the other hand, the high-temperature offset resistance was determined by visually observing the fixed image and the surface of the fixing roller, and determining whether or not a high-temperature offset occurred at each temperature.

Rank of high-temperature offset resistance: ：: High-temperature offset generation temperature ≧ 210 ° C .: 200 ° C. ≦ high-temperature offset generation temperature <210 ° C. ○: 190 ° C. ≦ high-temperature offset generation temperature <200 ° C. Δ: 180 ℃ ≦ temperature at which high-temperature offset occurs <190 ° C. X: temperature at which high-temperature offset occurs <180 ° C.

Evaluation Method of Fixing Roller Winding Using the external fixing device, the temperature at which a solid image was fixed on the entire surface of the transfer paper (80 g / m ² ) and the transfer paper was wound around the fixing roller was defined as the winding start temperature.

Rank of winding of the fixing roller: 開始: winding start temperature ≧ 200 ° C. Δ: 180 ° C. ≦ winding start temperature <200 ° C. X: winding start temperature <180 ° C.

Examples 8 to 10 Instead of the phthalocyanine pigment, a magenta colorant (C.I.
I. Pigment Red 122), 13 parts by weight of a yellow colorant (CI Pigment Yellow 173), and 15 parts by weight of a black colorant (grafted carbon black) in the same manner as in Example 1 except that magenta was used. Toner particles, yellow toner particles and black toner particles were produced. Table 5 shows the results.

Next, a two-component developer for each color was prepared in the same manner as in Example 1.

[0129]

[Table 5]

Experimental Example Two-component developer for cyan of Example 1, two-component developer for magenta of Example 8, two-component developer for yellow of Example 9, and two-component developer for black of Example 10. When an image output test was performed in full color mode using a developer, a full color image faithful to the original image was obtained.

The offset phenomenon did not occur even if silicone oil was not applied to the fixing roller, and no trouble occurred in the fixing process even when double-sided fixing was performed on plain paper.

[0132]

According to the present invention, the toner of the present invention has improved durability, finely disturbs the charging property of the toner surface by using a polymer as in the prior art, and has a charge control material on the surface of the toner particles. Rather than being prevented by adhesion, the interior or center of the low softening point compound is first covered by an inner layer, which is further covered by an upper layer. Then, the toner particles are embedded with an epoxy resin or the like, and further, the cross section is stained with ruthenium tetroxide and osmium tetroxide, and when the section is later observed using a transmission electron microscope, the inside, By forming the material that can form the inner layer and the upper layer with materials that are identified as being different from each other, the colorant and the low softening point substance of the toner of the present invention are well encapsulated in the toner particles, and excellent development characteristics are obtained. And fixing characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross section of toner particles dyed with ruthenium tetroxide and osnium tetroxide.

FIG. 2 is a schematic diagram of a DSC curve of an ester wax.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI G03G 9/08 384 (56) References JP-A-2-199459 (JP, A) JP-A-6-148925 (JP, A) JP-A 5-197193 (JP, A) JP-A-6-337539 (JP, A) JP-A-7-120965 (JP, A) JP-A-7-49582 (JP, A) JP-A-63-128361 (JP, A) A) JP-A-63-217357 (JP, A) JP-A-6-317925 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08-9/087

Claims (36)

(57) [Claims] 1. An electrostatic image developing toner comprising toner particles containing at least a binder resin and a colorant, wherein the toner particles comprise at least a low softening point substance forming the interior and the interior A material having an inner layer covering the inner layer and an upper layer covering the inner layer and the inner layer, wherein the inner layer, the inner layer, and the upper layer can be distinguished by ruthenium tetroxide and osmium tetroxide dying. Consists of an inner layer
Is a styrene polymer or styrene-acrylic copolymer
A toner for developing an electrostatic image, wherein the toner is formed of a solid or a styrene-methacrylic copolymer . 2. The low softening point compound forming the inside has a weight average molecular weight of 300 to 1,500, a ratio of weight average molecular weight / number average molecular weight of 1.5 or less, and an endothermic main peak in a DSC endothermic curve. The toner according to claim 1, wherein the toner has a tangent separation temperature of 40 ° C. or higher. 3. The toner according to claim 1, wherein the inner layer has a glass transition point of more than 50 ° C. and less than 100 ° C. 4. The toner according to claim 1, wherein the upper layer is formed of a polyester resin or a derivative thereof. 5. The method according to claim 1, wherein the upper layer has a polyester resin formed from a bisphenol-based polyol having a glass transition point of 55 to 80 ° C. and an aromatic polycarboxylic acid. Toner. 6. The toner particles, wherein the low softening point substance is 5 to 30.
The toner according to any one of claims 1 to 5, wherein the toner is contained by weight%. 7. The toner according to claim 1, wherein the upper layer has a thickness of 0.01 to 0.5 μm. 8. The toner particles have a shape factor SF-1 of 100.
The toner according to any one of claims 1 to 7, wherein 9. The toner particles have a shape factor SF-1 of 100.
The toner according to claim 8, wherein the number is from 0.1 to 125. 10. The toner has a weight average particle diameter of 3 to 8 μm.
The toner according to any one of claims 1 to 9, wherein a number variation coefficient is 35% or less. 11. The toner according to claim 1, wherein the toner particles are polymerized toner particles directly produced by polymerizing a polymerizable monomer in an aqueous medium. 12. The low softening point substance forming the inside has a weight average molecular weight of 300 to 1,500, a ratio of weight average molecular weight / number average molecular weight of 1.5 or less, and an endothermic main peak in a DSC endothermic curve. The toner according to any one of claims 1 to 11, wherein the toner has a value of 55 to 120 ° C, a tangent departure temperature of 40 ° C or higher, and the upper layer is formed of a polyester resin or a derivative thereof. 13. An inner layer having a glass transition point of more than 50 ° C. and less than 100 ° C., and an upper layer having a glass transition point of 55 to 80 ° C., which is a polyester formed from a bisphenol polyol aromatic polycarboxylic acid. 13. The toner according to claim 12, comprising a system resin. 14. The toner particles may have a low softening point substance of 5 to 3 times.
14. The toner according to claim 12, which contains 0% by weight. 15. The toner particles contain 10 to 3 low softening point substances.
15. The toner according to claim 14, comprising 0% by weight. 16. The upper layer has a thickness of 0.01 to 0.5 μm.
And the toner particles have a shape factor SF-1 of 100 to 15
The toner according to claim 14, wherein the toner has a value of 0. 17. The toner particles having a shape factor SF-1 of 10
17. The toner according to claim 16, wherein the number is from 0 to 125. 18. The toner has a weight average particle diameter of 3 to 8 μm.
The toner according to claim 17, wherein the number variation coefficient is 35% or less. 19. The toner of claim 19, wherein the toner particles are more directly formed polymerized toner particles that polymerize a polymerizable monomer in an aqueous medium. 20. The low-softening point substance is an ester wax, wherein a value of an endothermic main peak in a DSC endothermic curve is at a temperature of 60 to 90 ° C., and a half value width of the endothermic main peak is within 10 ° C. 20. The toner according to any one of items 1 to 19 above. 21. The toner according to claim 20, wherein the ester wax has an endothermic main peak at a temperature of 60 to 85 ° C., and a half width of the endothermic main peak is within 5 ° C. 22. A polymerizable monomer composition comprising at least a polymerizable monomer, a colorant, a substance having a low softening point, a resin having a polar group, and a polymerization initiator. Is dispersed in an aqueous medium to form particles of the polymerizable monomer composition, and the polymerizable monomer in the particles is polymerized to form toner particles, which are lower than the endothermic main peak temperature of the low softening point substance. The aqueous medium is heated to 5 ° C. or higher and at least 5 ° C. higher than the glass transition temperature of the resin having a polar group, and then the aqueous medium is cooled to 50 ° C. or less at a cooling rate of 2 ° C. or less per minute. What is claimed is: 1. A method for producing a toner, comprising filtering particles from an aqueous medium to produce toner particles, the toner particles comprising: at least a low softening point substance forming the inside; an inner layer covering the inside; And an upper layer covering the inner layer. And the inner layer and the upper layer are made of a material that can be identified by a ruthenium tetroxide and osmium tetroxide dyeing method, and the inner layer is made of a styrene polymer.
Or styrene-acrylic copolymer or styrene-
A method for producing a toner, comprising a methacrylic copolymer . 23. After the polymerization of the polymerizable monomer, the polymer or copolymer of the polymerizable monomer is 5 ° C. higher than the theoretical glass transition temperature.
23. The method for producing a toner according to claim 22, wherein the aqueous medium is heated to a higher temperature. 24. The low-softening compound forming the inside has a weight average molecular weight of 300 to 1,500, a ratio of weight average molecular weight / number average molecular weight of 1.5 or less, and an endothermic main peak in a DSC endothermic curve. The toner production method according to claim 22, wherein the value of the toner is 55 to 120 ° C. and the tangent departure temperature is 40 ° C. or higher. 25. The method according to claim 22, wherein the inner layer has a glass transition point of more than 50 ° C. and less than 100 ° C. 26. The method according to claim 22, wherein the upper layer is formed of a polyester resin or a derivative thereof. 27. The upper layer according to claim 22, wherein the upper layer comprises a polyester resin formed from a bisphenol-based polyol having a glass transition point of 55 to 80 ° C. and an aromatic polyvalent carboxylic acid. Toner production method. 28. The toner according to claim 28, wherein the low softening point substance is 5 to 3 times.
The method for producing a toner according to any one of claims 22 to 27, comprising 0% by weight. 29. The upper layer has a thickness of 0.01 to 0.5 μm.
The method for producing a toner according to any one of claims 22 to 28, wherein 30. A toner particle having a shape factor SF-1 of 10
30. The method for producing a toner according to claim 22, wherein the number is from 0 to 150. 31. A toner particle having a shape factor SF-1 of 10
The method for producing a toner according to claim 32, wherein the number is from 0 to 125. 32. The toner has a weight average particle diameter of 3 to 8 μm.
32. The method according to claim 22, wherein the number variation coefficient is 35% or less. 33. The low-softening substance forming the inside has a weight average molecular weight of 300 to 1,500, a ratio of weight average molecular weight / number average molecular weight of 1.5 or less, and an endothermic main peak in a DSC endothermic curve. The toner production method according to any one of claims 22 to 32, wherein the value is 55 to 120 ° C, the tangent departure temperature is 40 ° C or more, and the upper layer is formed of a polyester resin or a derivative thereof. 34. The inner layer has a glass transition point of more than 50 ° C. and less than 100 ° C., and the upper layer is formed from a bisphenol-based polyol having a glass transition point of 55 to 80 ° C. and an aromatic polycarboxylic acid. 34. A polyester resin having a polyester resin.
The method for producing a toner according to any one of the above. 35. The low-softening point substance is an ester wax, wherein a value of an endothermic main peak in a DSC endothermic curve is at a temperature of 60 to 90 ° C., and a half value width of the endothermic main peak is within 10 ° C. 35. The method for producing a toner according to any one of items 34 to 34. 36. The method according to claim 35, wherein the ester wax has an endothermic main peak at a temperature of 60 to 85 ° C., and a half-width of the endothermic main peak is within 5 ° C.