JP3108824B2 - Electrostatic image developing toner and heat fixing method - 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 suitable for heat fixing used in electrophotography, electrostatic recording and magnetic recording, and a heat fixing method for fixing the toner by heating. .

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Many methods are known as described in Japanese Patent Publication No. JP-A-Heisei, 43-24878 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. Forming and then developing the latent image with toner,
After transferring the toner image to a transfer material such as paper as necessary,
The toner is fixed by heating, pressure, heat and pressure, or solvent vapor to obtain a copy, and the toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above steps are repeated.

In recent years, such copying apparatuses have begun to be used not only as office work copying machines for simply copying original documents, but also as printers as personal computer outputs or personal copying machines for individuals. .

[0004] For this reason, smaller, lighter, faster, and more reliable devices have been strictly pursued, and machines have become simpler in various respects. As a result, the performance required of the toner has become higher, and if the performance of the toner cannot be improved, a better machine cannot be realized.

For example, various methods and apparatuses have been developed for fixing a toner image to a sheet such as paper. For example, there are a compression heating method using a heat roller and a heat fixing method in which a heating member is brought into close contact with a heating member via a film.

In the heating method using a heating roller or a film, the toner is fixed by allowing the toner image surface of the sheet to be fixed to pass through the surface of the heat roller or the film formed of a material having a releasable property to the toner. Is performed. In this method, since the surface of the heat roller or the film comes into contact with the toner image of the sheet to be fixed, the thermal efficiency at the time of fusing the toner image onto the sheet to be fixed is extremely good, and the fixing can be performed quickly. It is very effective in an electrophotographic copying machine. However, in the above method, a part of the toner image adheres to and transfers to the fixing roller or film surface because the heat roller or the film surface and the toner image come into contact in a molten state, and the toner image re-transfers to the next sheet to be fixed. A so-called offset phenomenon occurs, and the sheet to be fixed may be stained. Preventing the toner from adhering to the heat fixing roller and the film surface is one of the essential conditions of the heat fixing method.

Conventionally, for the purpose of preventing toner from adhering to the surface of the fixing roller, for example, the surface of the roller is formed of a material having excellent release properties with respect to the toner, such as silicone rubber or a fluorine-based resin. In order to prevent the roller surface from being fatigued, the roller surface is coated with a thin film of a liquid having good releasability such as silicone oil. However, this method is extremely effective in preventing toner offset, but has a problem that a fixing device is complicated because a device for supplying an anti-offset liquid is required. .

[0008] This is in the opposite direction of miniaturization and weight reduction, and moreover, silicone oil and the like may evaporate due to heat and contaminate the inside of the machine. Therefore, instead of using a silicone oil supply device, instead of supplying the anti-offset liquid during heating from the toner, a method of adding a release agent such as low molecular weight polyethylene or low molecular weight polypropylene to the toner is proposed. Have been. If a large amount of such an additive is added in order to obtain a sufficient effect, filming on a photoreceptor or contamination of the surface of a toner carrier such as a carrier or a sleeve will cause deterioration of an image and pose a practical problem. Therefore, a device is used in which a small amount of a release agent is added to the toner so as not to deteriorate the image, and a small amount of release oil is supplied or the offset toner is wound up with a device using a web-type member such as a web. It has been used in combination.

However, in view of recent demands for miniaturization, weight reduction, and high reliability, it is necessary and preferable to remove even these auxiliary devices. Therefore, if there is no further performance improvement such as toner fixing and offset,
It is difficult to realize this without further improvement of the binder resin of the toner, the release agent and the like.

It is known that a wax is contained in a toner as a release agent. For example, JP-A-52-330
No. 4, JP-A-52-3305, JP-A-57-3305.
A technique such as 52574 is disclosed.

Further, JP-A-3-50559, JP-A-2-79860, JP-A-1-109359, JP-A-62-14166, and JP-A-61-27
No. 3554, No. 61-94062, Japanese Unexamined Patent Publication No. Sho 61
-138259, JP-A-60-252361, JP-A-60-252360, JP-A-60-2
No. 17366 discloses a technique for containing waxes.

[0012] Waxes are used for improving the offset resistance of the toner at low and high temperatures and for improving the fixing property at low temperatures. However, while these properties are improved, blocking resistance is deteriorated and developability is deteriorated.

No conventional toner satisfies all of these aspects, causing some problems. For example, the high temperature offset and the developing property are excellent, but the low temperature fixing property is just one step away, or the low temperature offset and the low temperature fixing property are excellent, but the blocking resistance is slightly inferior and the developing property is deteriorated. Or the offset resistance at low and high temperatures cannot be compatible.

Also, low molecular weight polypropylene (for example,
Viscole 550P, 660 manufactured by Sanyo Chemical Industry Co., Ltd.
P, etc.) are commercially available, but toners with further improved low-temperature offset properties and improved fixability have been desired.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner which solves the above-mentioned problems and a method for fixing the toner by heating.

That is, an object of the present invention is to provide a toner excellent in fixing property at low temperature and anti-offset property, and a method for heat-fixing the toner.

It is another object of the present invention to provide a toner having excellent offset resistance at high temperatures and a method for fixing the toner by heating.

It is a further object of the present invention to provide a toner which has excellent blocking resistance and does not deteriorate developability, and a method for heat-fixing the toner.

It is a primary object of the present invention to provide a toner and a method for heating and fixing the toner, which satisfy the above objects without inconsistency.

[0020]

According to the present invention, there is provided a toner for developing an electrostatic image containing at least a binder resin and a wax component, wherein the molecular weight distribution of the toner by GPC is from 3 × 10 ^{3 to} 5 × 10 ^{3. At} least one peak exists in the region of No. ⁴ , at least one peak exists in the region of 10 ⁵ or more, the component of 10 ⁵ or less is 50% or more, and the DSC measured by a differential scanning calorimeter of the wax is There are at least one endothermic peak P ₁ during the temperature increase of the area of the temperature 70 to 130 ° C. in a curve, that there is a maximum exothermic peak at the time of temperature drop within a range of ± 9 ° C. of the peak temperature of the endothermic peak P ₁ The present invention relates to a toner for developing an electrostatic image.

Further, the present invention relates to a heat fixing method characterized by fixing a toner image formed with the toner for developing an electrostatic image to a transfer material by a contact heating means.

Further, the present invention will be described in detail.

The resin component having a molecular weight of 5 × 10 ⁴ or less is a component mainly governing the fixing property and the blocking property, and the component having a molecular weight of 10 ⁵ or more is a component mainly governing the high-temperature offset property. By appropriately mixing these components, the balance between the fixing property and the offset resistance can be obtained. Further, by forming the toner with a specific wax component, the performance can be effectively improved.

According to the present invention, in the molecular weight distribution of the toner by GPC, a region of 3 × 10 ^{3 to} 5 × 10 ⁴ , preferably a region of 3 × 10 ^{3 to} 3 × 10 ⁴ , particularly preferably
It is characterized in that at least one peak exists in a region of 5 × 10 ^{3 to} 2 × 10 ⁴ , and the peak in this region is preferably the maximum peak, and good fixability can be obtained. If it is less than 3 × 10 ³ , good blocking resistance cannot be obtained, and if it exceeds 5 × 10 ⁴ , good fixability cannot be obtained.

Further, a region of 10 ⁵ or more, preferably 3 ×
It is characterized in that at least one peak exists in a region of 10 ^{5 to} 5 × 10 ⁶ , and it is particularly preferable that a region of 3 × 10 ⁵ to 2 × 10 ⁶ has a maximum peak in a region of 10 ⁵ or more. And good hot offset resistance.
The larger the peak molecular weight is, the stronger the high-temperature offset becomes. However, when a peak exists in a region of 5 × 10 ⁶ or more, there is no problem with a hot roll to which pressure can be applied. In addition, the elasticity increases and the fixing property is affected. Therefore, in the case of heat fixing at a relatively low pressure used in a medium-speed machine, 3 × 1
There is a peak in 0 ⁵ to 2 × 10 ⁶ regions, which are 10 ⁵
It is preferable that the peak is the maximum peak in the above-described region, and that this peak is the second peak in the entire region, which is the most preferable form for balancing the offset and the fixing.

Further, the component in the region of 10 ⁵ or less is characterized by being 50% or more, preferably 60 to 90%, particularly preferably 65 to 85%. When the content is within this range, good fixability is exhibited, and the effect of the wax component of the present invention is sufficiently exerted to obtain good fixability and offset resistance. If it is less than 50%, not only the sufficient fixing property cannot be obtained but also the pulverizability becomes inferior. If it exceeds 90%, it tends to be weak against high-temperature offset.

Further, according to the present invention, the temperature of the wax component is determined to be 70 to 13 in the DSC curve when the temperature is increased by a differential scanning calorimeter.
In the region of 0 ° C, preferably in the region of 80-130 ° C,
Particularly preferably, may be in the region of 90 to 120 ° C., and wherein there are endothermic peak P ₁ of at least one, obtain good fixability and offset resistance. That is, by melting the wax in this temperature range, a plasticizing effect is given to the binder resin, the fixing property is improved, and the releasing effect is exhibited, and the performance against low-temperature offset and high-temperature offset is improved. Such waxes have a molecular weight of 10 ⁵
The plasticizing effect works effectively for the following resin components,
Effective for components of × 10 ⁴ or less, 3 × 10 ³ to
A GPC peak exists in a region of 5 × 10 ⁴ , and when the component of 10 ⁵ or less is 50% or more, good fixability can be exhibited. However, for components of 3 × 10 ³ or less, the plasticizing effect becomes large and the blocking resistance becomes poor, so that the GPC peak of the binder resin is preferably in the range of the present invention. The peak temperature of the wax is 70
When the temperature is lower than 0 ° C, the plasticizing effect works from a low temperature, and the blocking resistance becomes poor, and the wax dissolves at a low temperature, so that the releasing effect cannot be exhibited at a high temperature. Also, when the peak temperature of the wax is lower than 90 ° C., the blocking resistance tends to be inferior.
^When the resin component has ^five or more resin components, the influence of the plasticity of the low molecular weight portion is suppressed, so that the blocking resistance can be compensated. Further, although the high-temperature offset property tends to be inferior, the elasticity of the polymer portion provides a margin for the high-temperature offset resistance. On the other hand, DS over 130 ℃
Although the C peak may be present, if the DSC peak does not exist in the region of 130 ° C. or lower, the melting temperature of the wax is too high, and the fixability and the low-temperature offset resistance become poor.

In the DSC curve at the time of temperature decrease, an exothermic peak accompanying wax coagulation and crystallization is observed. The presence of an endothermic peak upon heating at a temperature close to this exothermic peak indicates that the wax is more homogeneous, characterized by a difference within 9 ° C, preferably within 7 ° C. is there. That is, by reducing this difference, the wax can be made into a sharp melt, phase separation can be clearly generated at a high temperature, the mold releasability can be effectively exhibited, and the offset resistance is excellent. Further, since the wax is dispersed in a homogeneous state, it does not adversely affect the triboelectric charging property, and the developing property becomes excellent. Further, since the phase separation easily occurs, it is difficult to disperse the binder resin in the binder resin. However, since the resin component having a molecular weight of 10 ⁵ or more increases the melt viscosity,
The dispersibility in the binder resin can be improved.

In the present invention, it is preferable that the half-width of the maximum endothermic peak is at least 10 ° C., especially at least 15 ° C. in a DSC curve of the wax component when the temperature is increased by a differential scanning calorimeter. Properties and low-temperature and high-temperature offset resistance. When the temperature at the start point of the endothermic peak is low, the temperature at which the wax changes becomes low,
The temperature at which the plasticizing effect on the binder resin is given can be lowered. Therefore, low-temperature fixability and low-temperature offset resistance can be improved. When the temperature at the end point of the endothermic peak is high, the end temperature of the melting of the wax increases, so that the high-temperature offset resistance can be improved. Also, the higher the height of the endothermic peak, the greater the change in wax at that temperature. Therefore, as the half width of the maximum peak is larger, the temperature at which the wax works effectively becomes wider, so that the non-offset region can be widened and the low-temperature fixability can be improved. When the half width is less than 10 ° C., if the peak temperature is high, the high-temperature offset is effective, but the low-temperature fixability is poor. If the peak temperature is low, the low-temperature offset is effective, but the high-temperature offset is effective. It becomes inferior and it is difficult to balance. When calculating the half width, if the peaks are continuous (as a rule, the height of the minimum value between the peaks is one-fourth or more of the height of the maximum peak value), a part of the peaks is Although it may be less than half the height (in the case as shown in FIG. 1), the region having the peak at the half height or more is 10 ° C. or more, preferably 15 ° C. or more, Those having a half width (as shown in FIGS. 2 and 3) can more effectively achieve the object of the present invention.

In order to improve the low-temperature offset resistance and the low-temperature fixability, the onset temperature at the starting point of the endothermic peak is preferably 100 ° C. or lower, particularly preferably 50 to 100 ° C.
It is within the range of 90 ° C. When the temperature exceeds 100 ° C., the low-temperature fixing and offset characteristics are inferior, and when it is lower than 50 ° C., the blocking resistance tends to be inferior.

The wax used in the present invention may be a low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or a Ziegler catalyst under low pressure, an alkylene polymer obtained by thermally decomposing a high molecular weight alkylene polymer, monoxide, A wax obtained by extracting and separating a specific component from a hydrocarbon distillation residue obtained from the synthesis gas consisting of carbon and hydrogen by the Age method, or from a synthetic hydrocarbon obtained by hydrogenating the same, is used as an antioxidant. May be added. The wax is separated and homogenized by a separation crystallization method using a press sweating method, a solvent method, and vacuum distillation. Hydrocarbons as bases are metal oxide catalysts (often two or more types).
Synthesized by the reaction of carbon monoxide and hydrogen using, for example, the Zintole method, the hydrochol method (using a fluidized catalyst bed), or the Aage method using a large amount of waxy hydrocarbons (using a fixed catalyst bed). Hydrocarbons having a carbon number of up to about several hundreds (particularly preferred are those obtained by hydrogenation to obtain the desired product) and hydrocarbons obtained by polymerizing alkylene such as ethylene with a Ziegler catalyst have few branches and are less saturated Preference is given to long linear hydrocarbons. In particular, a hydrocarbon wax synthesized by a method that does not rely on the polymerization of alkylene is preferable because of its structure and a molecular weight distribution that can be easily separated. A preferable range in the molecular weight distribution is a number average molecular weight (Mn) of 3
00-1200 preferably 350-1000. The weight average molecular weight (Mw) is 500-3600, preferably 55.
0 to 3000, Mw / Mn is 3 or less, preferably 2.5
The value is particularly preferably 2.0 or less. By providing such a molecular weight distribution, the toner can have favorable thermal characteristics.

The degree of crystallinity is 80% or more, preferably 8%.
When the content is 5% or more, the homogeneity is good, the triboelectric charge is not adversely affected, and the particles are dispersed in a state in which the phases are easily separated, so that the releasing effect is easily exerted, and excellent offset resistance is obtained. As other physical properties, the density at 25 ° C. is 0.93 (g / cm ³ ) or more and the penetration is 5.0 (10
^-1 mm) or less, preferably 4.0 (10 ^-1 mm) or less,
Particularly preferably, it is 3.0 (10 ^-1 mm). If the ratio is out of these ranges, it tends to change at a low temperature, resulting in poor storage stability and developability. The melt viscosity at 140 ° C. is 100 c
P or less, preferably 50 cP or less, particularly preferably 20 cP or less.
cP or less. If it exceeds 100 cP, the plasticity and the releasability will be inferior, and the excellent fixing property and the offset resistance will be affected. The softening point is 13
0 ° C. or lower, particularly preferably 120 ° C.
It is below ° C. When the temperature exceeds 130 ° C., the temperature at which the mold release property is particularly effective becomes high, which affects the excellent offset resistance.

The content of these hydrocarbon waxes is not more than 20 parts by weight based on 100 parts by weight of the binder resin.
It is effective to use 0.5 to 10 parts by weight, and it may be used in combination with other waxes.

In the DSC measurement according to the present invention, it is preferable to use a highly accurate internal heating type input compensation type differential scanning calorimeter in view of the measurement principle. For example, DSC-7 manufactured by PerkinElmer can be used.

The measurement method is as described in ASTM D3418-82.
Perform according to. As the DSC curve used in the present invention, a DSC curve measured when the temperature is raised once, the pre-history is taken, and then the temperature is decreased and raised at a temperature rate of 10 ° C./min. The definition of each temperature is defined as follows.

[0036] (a heat absorbing the positive direction) the peak temperature of the endothermic peak P ₁ either peak peak top temperature there is a peak top temperature in the region of 70 to 130 ° C. for during heating.

(An example of the wax A of the present invention is shown in FIG. 4 as a specific example.) Peak temperature of an exothermic peak (heat is defined in a minus direction) Peak top temperature of a maximum peak at the time of temperature decrease (a specific example of the present invention) An example of wax A is shown in FIG. 5.) The half-width of the maximum endothermic peak (the endotherm is in the plus direction). The peak of the maximum endothermic peak is at least half the height from the baseline to the peak top. As long as the existing temperature width peaks are continuous, the peaks do not have to be continuous at a height equal to or more than half the height in all regions of the half width.

End-point onset temperature of endothermic peak The temperature at the intersection of the curve and the base line at the point where the differential value of the curve at the time of temperature rise becomes the first maximum (FIG. 1 to FIG. In the present invention, the molecular weight distribution of the hydrocarbon wax is measured by gel permeation chromatography (GPC) under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150
C (Waters) Column: GMH-HT 30 cm 2 columns (manufactured by Tosoh Corporation) Temperature: 135 ° C Solvent: o-dichlorobenzene (0.1% ionol added) Flow rate: 1.0 ml / min Sample: 0.15% sample 0.4 ml injection 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. Further, it is calculated by converting to polyethylene using a conversion formula derived from the Mark-Houwink viscosity formula.

The crystallinity is determined by X-ray diffraction.
The diffraction pattern by the crystal becomes a sharp peak, and the scattering by the amorphous becomes a very broad halo. When both crystalline and amorphous are present, the ratio of crystalline to the entire sample is referred to as crystallinity. The total X-ray scattering intensity (intensity of coherent scattering excluding Compton scattering) is always constant irrespective of the quantitative ratio between crystalline and amorphous. Therefore, the crystallinity χ (%) is obtained by the following equation.

Χ (%) = Ic / (Ic + Ia) × 100 Ic: peak area of scattering intensity of crystalline portion of unknown sample Ia: peak area of scattering intensity of amorphous portion of unknown sample The penetration is JIS K-2
This is a value measured according to 207. Specifically, it is a numerical value representing the penetration depth when a needle having a conical tip having a diameter of about 1 mm and a vertex angle of 9 ° is penetrated with a constant load in a unit of 0.1 mm. The test conditions in the present invention are as follows.
The weight is 100 g and the penetration time is 5 seconds.

The melt viscosity is a value measured using a Brookfield viscometer.
40 ° C., shear rate 1.32 rpm, sample 10 ml. The density is JIS K6760 at 25 ° C and the softening point is JIS
This is a value measured according to SK2207.

In the present invention, the molecular weight distribution of the chromatogram of the toner by GPC (gel permeation chromatography) using THF as a solvent is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) as a solvent was passed through the column at this temperature at a flow rate of 1 ml per minute, and about 100 μl of a THF sample solution was injected. Measure. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared from several kinds of monodisperse polystyrene standard samples and the count number. As a standard polystyrene sample for preparing a calibration curve, for example, one having a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko KK is used.
It is appropriate to use about 0 standard polystyrene samples. An RI (refractive index) detector is used as the detector.
As the column, a combination of a plurality of commercially available polystyrene gel columns may be used. For example, Shodex GPC KF-801, 802, 80 manufactured by Showa Denko KK
3,804,805,806,807,800P or TSKgelG1000H (H
_{XL), G2000H (H XL)} , G3000H (H XL),
_{G4000H (H XL), G5000H (} H XL), G60
00H (H _XL ), G7000H (H _XL ), TSKgua
rdcolumn can be mentioned.

A sample is prepared as follows.

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

The resin component characteristic of the present invention can be obtained, for example, by the following method.

By applying solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, block copolymerization, grafting, or the like, a polymer (L) having a main peak in a molecular weight region of 3 × 10 ^{3 to} 5 × 10 ⁴ is used. A polymer having a main peak in a region of 10 ⁵ or more or a polymer (H) containing a gel component is formed. These components can be obtained by blending during melt kneading. The gel component can be partially or completely cut at the time of melt-kneading, becomes a THF-soluble component, and is measured by GPC as a component in a region of 10 ⁵ or more.

As a particularly preferred method, the polymer (L)
Alternatively, the polymer (H) is formed by solution polymerization, and when the polymerization is completed, the other is blended in a solvent, the other polymer is polymerized in the presence of one polymer, and the polymer (H) is suspended. A method in which a polymer (L) is formed by polymerization in the presence of the polymer, and a method in which the polymer (H) is blended in a solvent at the end of the solution polymerization; And a method in which the polymer (H) can be polymerized by suspension polymerization. By using these methods, a polymer in which a low molecular weight component and a high molecular weight component are uniformly mixed can be obtained.

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

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin , Xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used. Preferred binders include styrene copolymers or polyester resins.

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

The styrene-based polymer or styrene-based copolymer may be cross-linked or a mixed resin.

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

In the bulk polymerization method, a low molecular weight polymer can be obtained by increasing the termination reaction rate by polymerizing at a high temperature, but there is a problem that the reaction is difficult to control.
In the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer depending on the solvent and by adjusting the amount of the initiator and the reaction temperature. It is preferable when a low molecular weight compound is obtained in the composition.

As the solvent used in the solution polymerization, xylene, toluene, cumene, cellosolve acetate, isopropyl alcohol, benzene and the like are used. In the case of a styrene monomer mixture, xylene, toluene or cumene is preferred. It is appropriately selected depending on the polymer to be polymerized.

The reaction temperature varies depending on the solvent used, the initiator and the polymer to be polymerized.
It is better to carry out at 0 ° C. In the solution polymerization, it is preferable to carry out the polymerization with 30 parts by weight to 400 parts by weight of the monomer per 100 parts by weight of the solvent.

Further, it is preferable to mix another polymer in the solution at the end of the polymerization, and several types of polymers can be mixed well.

As a polymerization method for obtaining a high molecular weight component or a gel component, an emulsion polymerization method or a suspension polymerization method is preferable.

Among them, the emulsion polymerization method is a method in which a monomer (monomer) almost insoluble in water is dispersed as small particles in an aqueous phase with an emulsifier, and polymerization is carried out using a water-soluble polymerization initiator. . In this method, it is easy to control the heat of reaction, and since the phase in which the polymerization is carried out (the oil phase composed of the polymer and the monomer) and the aqueous phase are different, the termination reaction rate is small, and as a result, the polymerization rate is large. , With a high degree of polymerization.
Further, the reason is that the polymerization process is relatively simple, and that the polymerization product is fine particles, so that it is easy to mix with the colorant, the charge control agent, and other additives in the production of the toner. This is advantageous as compared with other methods as a method for producing a binder resin for a toner.

However, the resulting polymer tends to be impure due to the added emulsifier, and an operation such as salting out is required to take out the polymer. Therefore, suspension polymerization is a simple method.

In the suspension polymerization, 100 parts by weight or less of the monomer (preferably 1 part by weight) is added to 100 parts by weight of the aqueous solvent.
(0 to 90 parts by weight). Examples of usable dispersants include polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, and the like. There is an appropriate amount in terms of the amount of a monomer relative to an aqueous solvent, and generally 0.05 to 1 based on 100 parts by weight of an aqueous solvent. Used in parts by weight. The polymerization temperature is suitably from 50 to 95 ° C, but should be appropriately selected depending on the initiator used and the intended polymer. In addition, any initiator can be used as long as it is insoluble or hardly soluble in water.

Examples of the initiator used include t-butyl peroxy-2-ethylhexanoate, cumyl perpivalate, t-butyl peroxy laurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, -T-butyl peroxide, t
-Butylcumyl peroxide, dicumyl peroxide, 2,2′-azobisisobutyronitrile, 2,2 ′
-Azobis (2-methylbutyronitrile), 2,2'-
Azobis (2,4-dimethylvaleronitrile), 2,
2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy)
3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (t-butylperoxycarbonyl) cyclohexane, 2,2-bis (t-butylperoxy) Octane,
n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, 1,3-bis (t-butylperoxy-isopropyl) benzene, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5
-Di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane,
Di-t-butyldiperoxyisophthalate, 2,2-
Bis (4,4-di-t-butylperoxycyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexahydro Terephthalate, di-t-butylperoxyazelate, 2,
5-dimethyl-2,5-di (t-butylperoxy) hexane, diethylene glycol-bis (t-butylperoxycarbonate), di-t-butylperoxytrimethyladipate, tris (t-butylperoxy) triazine, And vinyl tris (t-butylperoxy) silane. These can be used alone or in combination.

The amount used is 0.05 parts by weight or more (preferably 0.1 to 15 parts by weight) with respect to 100 parts by weight of the monomer.

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

The following substances control the toner to be negatively charged.

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

The following substances control the toner to be positively charged.

Modified products such as nigrosine and fatty acid metal salts. Quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate,
Onium salts such as phosphonium salts, which are analogs thereof, and their lake pigments, triphenylmethane dyes and these lake pigments (as the lake-forming agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannin Acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.) metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyltin borate Diorganotin borates; these can be used alone or in combination of two or more. Among these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

In the toner of the present invention, charging stability,
In order to improve developability, fluidity and durability, it is preferable to add silica fine powder.

The silica fine powder used in the present invention is BE
The specific surface area by nitrogen adsorption measured by the T method is 30 m ² / g
Those within the above range (particularly 50 to 400 m ² / g) give good results. It is preferable to use 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight of silica fine powder with respect to 100 parts by weight of the toner.

The silica fine powder used in the present invention is:
Silicon varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, and other organosilicon compounds for purposes such as hydrophobicity and charge control, if necessary It is also preferable that the composition is treated with such a treating agent or in combination with various treating agents.

As other additives, lubricant powders such as, for example, Teflon powder, zinc stearate powder and polyvinylidene fluoride powder are preferable, and polyvinylidene fluoride is particularly preferable.
Alternatively, abrasives such as cerium oxide powder, silicon carbide powder, and strontium titanate powder, among which strontium titanate is preferred. Or, for example, titanium oxide powder,
Fluidity-imparting agents such as aluminum oxide powder, particularly hydrophobic ones are preferred. A small amount of a caking inhibitor, a conductivity imparting agent such as a carbon black powder, a zinc oxide powder, an antimony oxide powder, a tin oxide powder, and the like, and fine particles of white and black having opposite polarities can also be used as a developing property improver.

Further, when the toner of the present invention is used as a two-component developer, it is used by mixing with a carrier powder. In this case, the mixing ratio of the toner and the carrier powder is 0.1 to 50% by weight as the toner concentration, preferably 0.5%.
It is preferably from 10 to 10% by weight, more preferably from 3 to 10% by weight.

As the carrier that can be used in the present invention, known carriers can be used. For example, magnetic powders such as iron powder, ferrite powder and nickel powder, glass beads, etc. And those treated with a vinyl resin or a silicone resin.

Further, the toner of the present invention can be used as a magnetic toner by further containing a magnetic material. In this case, the magnetic material can also serve as a colorant. In the present invention, the magnetic material contained in the magnetic toner includes iron oxide such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; and aluminum, cobalt, copper, lead, magnesium, and tin of these metals. ,
Examples include alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

These ferromagnetic materials preferably have an average particle size of 2 μm or less, preferably about 0.1 to 0.5 μm. The amount contained in the toner is preferably about 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight, per 100 parts by weight of the resin component.

The magnetic properties when a 10 K Oersted is applied are as follows: the coercive force ratio (Hc) is 20 to 300 Oersted, the saturation magnetization (σs) is 50 to 200 emu / g, and the residual magnetization (σ
r) Those having 2 to 20 emu / g are preferred.

The colorant that can be used in the toner of the present invention includes any suitable pigment or dye. As a colorant of the toner, for example, carbon black as a pigment,
Examples include alinine black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengala, phthalocyanine blue, indanthrene blue and the like. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, per 100 parts by weight of the resin.
Good addition amount by weight. A dye is further used for the same purpose. Examples include azo dyes, anthraquinone dyes, xanthene dyes, methine dyes and the like.
0.1 to 20 parts by weight, preferably 0.1 part by weight, per 0 parts by weight.
The addition amount of 3 to 10 parts by weight is good.

To prepare the toner for developing an electrostatic image according to the present invention, a binder resin, wax, a pigment or dye as a colorant, a magnetic substance, a charge control agent, and other additives as necessary are used. After mixing well with a mixer such as a Henschel mixer or a ball mill, melt-kneading using a hot kneader such as a heating roll, kneader or extruder to make the resins compatible with each other, The toner or the like according to the present invention can be obtained by dispersing or dissolving the body and the like, and then performing pulverization and classification after cooling and solidifying.

Further, if necessary, desired additives are sufficiently mixed by a mixer such as a Henschel mixer to obtain a toner for developing an electrostatic image according to the present invention.

The toner of the present invention can be applied to plain paper or an overhead projector (OH
The sheet is heat-fixed to a transfer material such as a transparent sheet for P).

As the contact heating fixing means, a heat and pressure roll fixing device or a fixedly supported heating element is pressed against the heating element, and the transfer material is brought into close contact with the heating element via a film. A fixing unit that heats and fixes the toner with the pressing member can be used.

FIG. 6 shows an example of the fixing means.

In the fixing device shown in FIG. 6, the heating element has a smaller heat capacity than that of a conventional heat roll and has a linear heating section. The maximum temperature of the heating section is 100 to 300.
C. is preferred.

The film located between the heating element and the pressing member is preferably a heat-resistant sheet having a thickness of 1 to 100 μm. Examples of the heat-resistant sheet include polyester, PET (polyethylene), and the like having high heat resistance. Terephthalate), PFA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, polymer sheet such as polyamide, metal sheet such as aluminum, and metal sheet and polymer sheet. A laminate sheet is used.

A more preferable structure of the film is that these heat-resistant sheets have a release layer and / or a low-resistance layer.

A specific example of the fixing device will be described with reference to FIG.

Reference numeral 1 denotes a low-heat-capacity linear heating element fixedly supported by the apparatus, and has a thickness of 1.0 mm and a width of 10 m as an example.
m, an alumina substrate 10 having a longitudinal length of 240 mm
Is applied to a width of 1.0 mm, and is energized from both ends in the longitudinal direction. The energization is performed by applying a pulse corresponding to a desired temperature and energy release amount controlled by the temperature detecting element 11 by changing the pulse width in a pulse-like waveform of DC 100 V and a cycle of 20 msec. Approximate pulse width is 0.5msec ~
5 msec. The fixing film 2 moves in the direction indicated by the arrow in the drawing while coming into contact with the heating element 1 whose energy and temperature are controlled in this manner.

An example of the fixing film has a thickness of 20 μm.
m is a heat-resistant film (for example, polyimide, polyetherimide, PES or PFA, and at least the image contacting surface side is a fluororesin such as PTFE or PFA) coated with a release layer having a thickness of 10 μm. Generally, the total thickness is less than 100μ, more preferably 4
Less than 0μ is good. The film is driven without wrinkles in the direction of the arrow by the driving and tension of the driving roller 3 and the driven roller 4.

Reference numeral 5 denotes a pressure roller having a rubber elastic layer having good releasability such as silicone rubber.
The heating element is pressurized through the film with g, and is rotated by pressing against the film. The unfixed toner 7 on the transfer material 6 is guided to a fixing unit by an entrance guide 8 and obtains a fixed image by the above-described heating.

The above description has been made with reference to the endless belt.
A sheet feeding shaft and a winding shaft are used, and the fixing film may be an edged film.

The image forming apparatus is applicable to a fixing device of an apparatus for forming an image using a toner such as a copying machine, a printer, and a fax.

[0094]

The present invention will be described below with reference to specific examples.

A wax A (the present invention), a wax B (the present invention) and a wax C (the present invention) were obtained from hydrocarbons synthesized by the Age method, and a wax was obtained from a low-pressure polymerized ethylene using a Ziegler catalyst. D (the present invention) was obtained. The wax obtained by thermal decomposition of polyethylene is referred to as wax E (comparative example). The DSC measurement results of the waxes are shown in Table 1, the molecular weight is shown in Table 2, and the physical properties are shown in Table 3.

Next, the binder resin will be described.

Synthesis Example 1 80 parts by weight of styrene 20 parts by weight of n-butyl acrylate 0.2 parts by weight of 2,2-bis (4,4-di-t-butylpropoxycyclohexyl) propane As a result, a polymer A was obtained.

83 parts by weight of styrene 17 parts by weight of butyl acrylate 1.0 part by weight of di-t-butyl peroxide From the above compound, a polymer B was obtained by a solution polymerization method using xylene as a solvent, and a polymer A and a polymer B were obtained. Was mixed at a weight ratio of 30:70 to obtain a binder resin 1.

Synthesis Example 2 80 parts by weight of styrene 20 parts by weight of n-butyl acrylate 0.1 part by weight of 2,2-bis (4,4-di-t-butylpropoxycyclohexyl) propane As a result, a polymer C was obtained.

Styrene 84 parts by weight Butyl acrylate 16 parts by weight Di-t-butyl peroxide 0.8 parts by weight From the above compound, a polymer D was obtained by a solution polymerization method using xylene as a solvent, and a polymer C and a polymer D were obtained. Was mixed at a weight ratio of 25:75 to obtain a binder resin 2.

Synthesis Example 3 80 parts by weight of styrene 20 parts by weight of n-butyl acrylate 0.2 parts by weight of 2,2-bis (4,4-di-t-butyl butyl peroxycyclohexyl) propane As a result, a polymer E was obtained.

82 parts by weight of styrene 18 parts by weight of butyl acrylate 4.0 parts by weight of di-t-butyl peroxide From the above compound, a polymer F was obtained by a solution polymerization method using xylene as a solvent, and a polymer E and a polymer F were obtained. Was mixed at a weight ratio of 40:60 to obtain a binder resin 3.

Synthesis Example 4 80 parts by weight of styrene 20 parts by weight of butyl acrylate 0.5 part by weight of di-t-butyl peroxide Binder resin 4 was obtained from the above compound by a solution polymerization method using xylene as a solvent.

Synthesis Example 5 30 parts by weight of polymer B 44.7 parts by weight of styrene 25 parts by weight of butyl acrylate 0.3 parts by weight of divinylbenzene 0.7 parts by weight of di-t-butylperoxy-2-ethylhexanoate Binder resin 5 was obtained from the compound by a suspension polymerization method.

[0105]

[Table 1]

[0106]

[Table 2]

[0107]

[Table 3] Example 1 Binder Resin 1 100 parts by weight Magnetic iron oxide 80 parts by weight (average particle size 0.25 μm; saturation magnetization 80 emu / g under 10 K Oersted residual magnetization 10 emu / g, coercive force 120 Oersted) Nigrosine 2 parts by weight Wax A 4 parts by weight After the above materials were preliminarily mixed, melt kneading was carried out by a biaxial kneading extruder set at 130 ° C. After cooling, the kneaded material was coarsely pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier to obtain toner 1 having a weight average particle diameter of 8 μm. 0.6 part by weight of positively charged hydrophobic colloidal silica was externally added to 100 parts by weight of this toner to prepare a developer. Table 4 shows the GPC measurement results of this toner.
It writes in.

Examples 2 to 4 Toners 2 to 4 were prepared in the same manner as in Example 1 except that the binder resins and waxes shown in Tables 5, 6 and 7 were used. Table 4 shows the GPC measurement result of each toner.

Comparative Examples 1 to 3 Toners 5 to 7 were prepared in the same manner as in Example 1 except that the binder resins and waxes shown in Tables 5, 6 and 7 were used. Table 4 shows the GPC measurement result of each toner.

Comparative Example 4 A toner 8 was prepared in the same manner as in Example 1 except that a low molecular weight polypropylene wax (Viscol 550P) manufactured by Sanyo Chemical Industries, Ltd. was used. Table 5 shows the fixability of Toner 8.

(Fixing, Offset Test) An unfixed image is obtained by a commercially available electrophotographic copying machine NP-1215 (manufactured by Canon Inc.), and a temperature-variable heat roller external using a Teflon coat as an upper roller and a silicone rubber as a lower roller. The test was performed using a fixing machine. Nip 4.5mm, Linear pressure 0.6kg / cm, Process speed 90mm / sec
The temperature was controlled every 5 ° C. in a temperature range of 100 to 230 ° C. Low-temperature offset, the fixability, the high-temperature offset using 80 g / m ² paper was evaluated using a 52 g / m ² paper. The fixability was measured by applying a load of 50 g / cm ² to the fixed image and applying a lens cleaning paper “daspe”.
r ”(0zu Paper Co. Ltd), and the temperature at which the density reduction rate before and after the rubbing was less than 10% was defined as the fixing start point. Raise
The highest temperature without offset was taken as the hot offset-free end point. The test results are summarized in Table 5, where the fixing start point, low-temperature offset free start point, high-temperature offset free end point, and non-offset area are described.

(Blocking Test) Approximately 20 g of the developer was put in a 100 cc plastic cup, left at 50 ° C. for 3 days, and evaluated visually. The results are shown in Table 6.

Excellent: No aggregates are seen Good: Aggregates are seen but easily collapsed Good: Aggregates are seen but collapse when shaken Impossible: Aggregates can be grasped and not easily collapsed (developability test ) About 100 g of the developer was evaluated for developability using a commercially available electrophotographic copying machine FC-5II (manufactured by Canon Inc.). Table 6 shows the results of the test (image density, fog).
It writes in.

Examples 5 to 8 and Comparative Examples 4 to 6 The unfixed images of the toners 1 to 7 were pressed against the heating member 1 as shown in FIG. A fixing and offset test was performed using an external fixing machine including a pressing member 5 that was brought into close contact with the heating element 1. As a material of the fixing film 2, an endless film in which a release layer of a fluororesin obtained by adding a conductive material to a polyimide film was coated by 10 μm was used. As the pressure roller 5,
The test was performed using silicone rubber with a nip of 4.0 mm, a total pressure between the heating body 1 and the pressure roller 5 of 10 kg, and a process speed of 90 mm / sec. The film was driven by driving and tension by a driving roller 3 and a driven roller 4, and energy was applied to the heating element 1 having a low heat capacity linear shape in a pulsed manner to control the temperature. The evaluation was performed in the same manner as in Example 1, and the results are shown in Table 7.

Example 9 100 parts by weight of binder resin 5 80 parts by weight of magnetic iron oxide (same as in Example 1) 1 part by weight of a chromium complex of 3,5-di-t-butylsalicylate 1 part by weight of wax A 3 parts by weight of the above material After the preliminary mixing, a toner 9 having a weight average particle size of 8 μm was obtained in the same manner as in Example 1. To 100 parts by weight of the above toner, 0.6 part by weight of hydrophobic colloidal silica was externally added to prepare a developer.

The GPC data is shown in Table 4. This developer was tested using a commercially available electrophotographic copying machine NP-8582 (manufactured by Canon Inc., heat roll fixing). In an environment of 15 ° C., when the copying machine was sufficiently cooled, 200 minutes of A3 (80 g) transfer paper was continuously copied 5 minutes after the power was turned on, and no offset was generated. The fixability of the eyes (density reduction rate 5%) was also good.

When a copy test of 20,000 sheets was performed,
An image without fog having an image density of 1.38 to 1.40 was obtained, and no fusing or the like occurred.

[0118]

[Table 4]

[0119]

[Table 5]

[0120]

[Table 6]

[0121]

[Table 7]

[0122]

According to the present invention, a binder resin having a specific molecular weight distribution and a wax are contained in a toner.
Since favorable thermal characteristics can be imparted to the toner, the following excellent effects are exhibited.

The present invention can provide a toner excellent in fixing property at low temperature and anti-offset property and a heat fixing method.

The present invention can provide a toner excellent in offset resistance at high temperatures and a heat fixing method.

The present invention can provide a toner having excellent blocking resistance and good developability.

The present invention can provide a toner that achieves the above effects without contradiction.

[Brief description of the drawings]

FIG. 1 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 2 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 3 is a diagram showing an endothermic peak portion of a DSC curve at the time of temperature rise.

FIG. 4 shows the DS of the wax A according to the present invention when the temperature is raised.
It is a figure showing a C curve.

FIG. 5 shows the DS of the wax A according to the present invention when the temperature is lowered.
It is a figure showing a C curve.

FIG. 6 is a schematic explanatory view showing a specific example of a fixing device for performing the heat fixing method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heating element 2 fixing film 3 drive roller 4 driven roller 5 pressure roller 6 transfer material 7 toner 8 entrance guide 9 resistance material 10 alumina substrate 11 detection element

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masashi Jimbo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tsutomu Onuma 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-56-16144 (JP, A) JP-A-61-87162 (JP, A) JP-A-62-115170 (JP, A) JP-A-53-96839 (JP, A) A) JP-A-58-223155 (JP, A) JP-A-63-216063 (JP, A) JP-A-59-148067 (JP, A) JP-A-61-62045 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (3)

(57) [Claims] An electrostatic image developing toner containing at least a binder resin and a wax component.
A molecular weight distribution by PC, at least one peak is present in the ³ × 10 3 ~5 × 10 ⁴ region, there are at least one peak in 10 ⁵ or more regions, 10 ⁵ The following components be 50% or more And a DSC curve of the wax measured by a differential scanning calorimeter at a temperature of 70 to 130 ° C.
At least one has an endothermic peak P ₁ during heating, developing an electrostatic charge image, characterized in that there is a maximum exothermic peak at the time of temperature drop within a range of ± 9 ° C. of the peak temperature of the endothermic peak P ₁ in the area For toner. 2. The electrostatic image development according to claim 1, wherein a half-width of a maximum endothermic peak at the time of temperature rise is 10 ° C. or more in a DSC curve of the wax measured by a differential scanning calorimeter. For toner. 3. An electrostatic image developing toner containing at least a binder resin and a wax component.
A molecular weight distribution by PC, at least one peak is present in the ³ × 10 3 ~5 × 10 ⁴ region, there are at least one peak in 10 ⁵ or more regions, 10 ⁵ The following components be 50% or more And a DSC curve of the wax measured by a differential scanning calorimeter at a temperature of 70 to 130 ° C.
At least one has an endothermic peak P ₁ during heating, are formed with a maximum heating toner for developing an electrostatic image peak is during the temperature decrease in a range of ± 9 ° C. of the peak temperature of the endothermic peak P ₁ in the area Fixing the transferred toner image to a transfer material by a contact heating means.