JP2984562B2 - Electrostatic image developing toner, image forming method, process cartridge, toner resin composition, and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic printing,
In an image forming method such as magnetic recording, the present invention relates to a toner for visualizing an electrostatic latent image, an image forming method using the toner, and a process cartridge having the toner.
Further, the present invention relates to a resin composition that can be used as a binder resin component constituting a toner and a method for producing the same.

[0002]

2. Description of the Related Art An electrophotographic method is disclosed in U.S. Pat.
Numerous methods are known as described in Japanese Patent Publication No. 7,691, Japanese Patent Publication No. 42-23910, 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, and then the latent image is developed using toner, and if necessary, a toner image is formed on a transfer material such as paper. After transferring, heating,
The image is fixed by pressure, heat and pressure or solvent vapor to obtain a copy. Further, the remaining toner that has not been transferred onto the photoreceptor is cleaned by various methods as necessary, and the above steps are repeated.

[0003] In recent years, such a copying apparatus has been strictly pursued for miniaturization, weight reduction, high speed, and high reliability, and as a result, the performance required of the toner has also become higher. For example, various methods and apparatuses have been developed for fixing a toner image on a sheet such as paper. At present, the most common method is a heat compression method using a heat roller. The heat compression bonding method using a heat roller performs fixing by allowing the toner image surface of a sheet to be fixed to pass through the surface of a heat roller having a surface formed of a material having releasability with respect to toner while contacting the surface under pressure. . In this method, since the surface of the heat roller and the toner image of the sheet to be fixed come into contact with each other under pressure, the thermal efficiency when fixing the toner image on the sheet to be fixed is extremely good, and the fixing can be performed quickly, It is very effective in high-speed electrophotographic copying machines.

However, in the above-described conventional heat roller fixing, (1) there is a time (a so-called wait time) during which the image forming operation is prohibited until the heat roller reaches a predetermined temperature.

(2) The heating roller is optimal for preventing defective fixing and transfer of toner to the heating roller (so-called offset phenomenon) due to fluctuations in the temperature of the heating roller due to the passage of a recording material or other external factors. It is necessary to maintain a high temperature, and for this purpose, it is necessary to increase the heat capacity of the heating roller or the heating element, which requires a large amount of electric power and causes a rise in the temperature inside the image forming apparatus.

(3) Since the pressure roller has a lower temperature than the fixing roller, when the recording material is discharged through the heating roller, the recording material and the toner on the recording material are cooled slowly. The toner becomes highly sticky, and in combination with the curvature of the roller, a paper jam may occur due to offset or entanglement of the recording material.

JP-A-63-313182 by the present applicant
In the publication, a toner device is heated through a heat-resistant sheet moved by a low-heat-capacity heating element heated and heated in a pulse shape, and a fixing device that fixes the toner image onto a recording material has a short wait time and forms an image with low power consumption. A device has been proposed. Similarly, in Japanese Patent Application Laid-Open No. 1-187852 by the present applicant, in a fixing device for heating and fixing a visible image of a toner to a recording material via a heat-resistant sheet, the heat-resistant sheet is provided with a heat-resistant layer and a release layer or a low-pressure layer. A fixing device that has a resistance layer and effectively prevents an offset phenomenon has been proposed.

However, in order to realize a fixing method that has a short wait time and low power consumption while achieving excellent fixability of a toner-visible image to a recording material, prevention of offset, and the like, a fixing device as described above is used. In addition, the characteristics of the toner are greatly affected.

Conventionally, a method using a toner having two peaks in a molecular weight distribution as a binder resin of a toner, and a low molecular weight wax are typified by the idea of imparting good fixability and offset resistance to the toner itself. A method of adding a low molecular weight polyolefin polymer to a toner has been proposed.

The method described in, for example, JP-A-56-1
6144, JP-A-2-23569, JP-A-63-127254, JP-A-3-26831, JP-A-62-9356, JP-A-3-725
Japanese Patent Application Laid-Open No. 52-3304 and Japanese Patent Application Laid-Open No. 52-330
No. 5, JP-A-57-52574, JP-A-58-58574
JP-A-215659, JP-A-60-217366, JP-A-60-252361, JP-A-60-2
No. 52362 is proposed.

However, simply using a binder resin having two peaks in the molecular weight distribution or including a certain release agent in the toner does not improve the fixing property and the offset resistance to some extent. Although it can be seen, not only does the binder component in the toner cause non-uniformity, but also hinders the dispersion of other components such as wax, and uneven distribution and release of specific components are likely to occur. In some cases, this may cause fusing to a photosensitive member or filming.

The use of a polyfunctional initiator in a binder resin having two peaks to increase the molecular weight on the high molecular weight side is also described in JP-A-2-272559 and JP-A-3-72505. However, in order to apply it to the fixing property at a lower temperature and the anti-offset property at a higher temperature, it is necessary to broaden the molecular weight distribution of the binder resin. When this is applied to a binder resin having two peaks, the compatibility between the low-molecular component and the high-molecular component is further deteriorated due to further polarization, so that the above-described serious problem is likely to occur. .

In order to improve the compatibility and dispersibility of the components of the toner, when the kneading conditions during the melt kneading in the production of the toner are strengthened, the molecular chains of the binder resin are cut off by the kneading or the like. Since the molecular weight at the time decreases, the offset resistance, particularly the hot offset property on the high temperature side, may be deteriorated. If a large amount of wax is added in order to exert a sufficient effect on the offset resistance, the blocking resistance is deteriorated, and the dispersion of the wax is further deteriorated. In some cases, the image is degraded, which may cause a practical problem.

On the other hand, Japanese Patent Application Laid-Open No. 61-114246 discloses that a vinyl monomer is grafted on a high molecular weight polymer component having a number average molecular weight of 30,000 or more, so that the molecular weight distribution of the resin is shifted toward the high polymer region. It has been proposed to widen and consequently improve the offset resistance. However, with such a binder resin, it is possible to broaden the molecular weight distribution to a certain extent in a state of relatively good compatibility, but the polymer-side component is selectively selected due to the shearing force applied during melt-kneading during toner production. The effect is reduced by half because it is cut into pieces. In particular, when applied to a magnetic toner that requires uniform dispersion of high-specific-gravity magnetic fine particles, it is very difficult to achieve both improvement in offset resistance and securing of developability. For example, when a resin having a relatively large molecular weight such as a number average molecular weight of more than 30,000 is used, the grafting ratio becomes low, and as a result, the generation of by-products is promoted.
The charging characteristics of a developer using such a resin become unstable, causing not only difficulty in combination with the image forming means, but also a problem that when the toner particle size is reduced for the purpose of high quality development, the New problems such as low density, toner fog on a white background, and defective cleaning are likely to occur.

The various properties required for the above-mentioned toners are often reciprocal to each other, and it is increasingly desired in recent years that both of them satisfy high performance.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic image, an image forming method, and a process cartridge which solve the above-mentioned problems.

An object of the present invention is to provide a toner for developing an electrostatic charge image having excellent heat fixing characteristics.

An object of the present invention is to provide a toner for developing an electrostatic image having excellent offset resistance.

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 an image forming method and a process cartridge using the above toner.

An object of the present invention is to provide a resin composition which can be suitably used for producing the above toner, and a method for producing the same.

[0022]

The present invention relates to a toner for developing an electrostatic image having at least a composition in which a binder resin component and a colorant are dispersed, wherein the binder resin component comprises:
Having a molecular weight of 50,000 or less and a branching index g ′ of 1
The present invention relates to a toner for developing an electrostatic image, characterized by containing a low-molecular-weight polymer component having a molecular weight of less than 1.

The present invention further provides a charging step of bringing a charging member into contact with a member to be charged and applying a voltage to the charging member from the outside to charge the member to be charged. An image forming step, a developing step of developing an electrostatic charge image with toner to form a toner image on a member to be charged, and a toner image on the member to be charged with or without an intermediate transfer member. A transfer step of transferring to a transfer material, and a fixing step of heating and fixing the toner image on the transfer material, wherein the toner is an electrostatic image development having a composition in which at least a binder resin component and a colorant are dispersed. And a binder resin component having a molecular weight of 5
The present invention relates to an image forming method comprising a low molecular weight polymer component having a molecular weight of not more than 10,000 and a branch index g ′ of less than 1.

Further, the present invention is a process cartridge comprising at least a developing means and a photoreceptor, wherein the developing means and the photoreceptor are integrally formed as a cartridge.
The process cartridge is detachable from the main body of the image forming apparatus, and the developing means has a toner, and the toner has a composition in which at least a binder resin component and a colorant are dispersed. A process cartridge, wherein the binder resin component contains a low molecular weight polymer component having a molecular weight of 50,000 or less and a branch index g ′ of less than 1; .

Further, the present invention contains a mixture of a low molecular weight polymer component and a high molecular weight polymer component, and the low molecular weight polymer component having a molecular weight of 50,000 or less has a branching index g ′ of less than 1. And a resin composition for toner.

Further, according to the present invention, there is provided a method for producing a resin composition for a toner having a mixture of a low molecular weight polymer component and a high molecular weight polymer, wherein the branching index g 'having a molecular weight of 50,000 or less is less than 1. The polymer component, as a polymerization initiator below

[0027]

[Outside 3] The present invention relates to a method for producing a resin composition for a toner, which is prepared by polymerizing a monomer in the presence of a peroxide having a functional group.

In the present invention, by precisely controlling the branched structure of the low-molecular-weight polymer component of the binder resin component, low-temperature fixing and anti-offset properties, as well as toner development characteristics and matching with an image forming apparatus can be enhanced. Was achieved.
This is presumed to be due to the improvement of the mobility of the polymer molecule due to the increase in the free terminal of the polymer and the improvement of the elasticity of the polymer due to the branched structure.

It is preferable that the resin composition in the toner of the present invention does not substantially contain a THF (tetrahydrofuran) -insoluble component. Specifically, 5% by weight based on the resin composition
Or less, preferably 3% by weight or less.

The THF-insoluble component in the present invention indicates a polymerization ratio of a polymer component (substantially crosslinked polymer) insoluble in a THF solvent in a resin composition in a toner,
It can be used as a parameter indicating the degree of crosslinking of the resin composition containing the crosslinking component. The THF-insoluble matter is defined by a value measured as follows.

Toner sample or resin composition 0.5 to
1.0 g was weighed (W ₁ g), placed in a thimble filter paper (for example, No. 86R manufactured by Toyo Roshi Kabushiki Kaisha), subjected to a Soxhlet extractor, and extracted with 100 to 200 ml of THF as a solvent for 6 hours. After evaporating the soluble component, the solution is vacuum-dried at 100 ° C. for several hours, and the amount of the THF-soluble resin component is weighed (W ₂ g). The weight of a component other than the resin component such as a magnetic substance or a pigment in the toner is represented by (W ₃
g). The THF-insoluble content is obtained from the following equation.

[0032]

[Outside 4]

When the content of the THF-insoluble component exceeds 5% by weight, it is difficult to achieve satisfactory low-temperature fixing.

The binder resin component in the toner composition according to the present invention contains a low molecular weight polymer having a molecular weight of 50,000 or less and a branch index g ′ of less than 1. In the present invention, the branching index of the low molecular weight polymer having a molecular weight of 50,000 or less is preferably 0.97 or less (more preferably 0.95 or less, further preferably 0.93 or less).

Jim Stockmeyer (Zimm St
branching index g of Ockmayer) is the intrinsic viscosity of the branched polymer having a branched structure [eta _branch], intrinsic viscosity [eta of a linear polymer having a straight chain structure having a molecular weight distribution identical molecular weight distribution and of the branched polymer _liner ] _Is calculated from the ratio [η _branch ] / [η _linear ].

The first of "size exclusion chromatography"
See pages 11-114 [1st ed. (1991.12.10), Sadao Mori, Kyoritsu Shuppan].

In the present invention, C.I. kuo, T .; Pr
ovder and M.W. E. FIG. "Eval by Koehler
uation abd Application of
aCommercial Single Capi
lary Viscometer System f
or the Characterizationof
Molecular Weight Distrib
union and Polymer Chain B
ranching "Presentedat the
1989 International GPC Sy
mposium, October 1-4, 1989,
(Issued by Waters) and further described in J.I. Less
c and C.I. Quiveron, Annulusi
s, 4,399 (1976) and J.M. Liq. , Chr
omatog. , 3, 407 (1982), etc.
The branching index g 'of a low molecular weight polymer component having a molecular weight of 50,000 or less is measured. The measurement is performed, for example, under the following conditions.

Apparatus: GPC-150CV (manufactured by Waters) Column: GMH-H, GMH-L (manufactured by Tosoh) Temperature: 30 ° C. Solvent: THF Flow rate: 1.0 ml / min. Sample: A sample having a concentration of 0.05 to 0.5% by weight is 0.2 m
l injection

Using the above apparatus, and further using a refractometer and a single capillary viscometer, GPCV software was used.
e is used to determine the Mark-Houwink parameters K and α, the molecular weight distribution and the viscosity of the polymer. Than,
This will be specifically described with reference to FIG.

First, the molecular weight distribution of the sample by GPC and the viscosity corresponding to each molecular weight component are measured. In the GPC graph, assuming that the intensity of the main peak is 100%, the branch index g ′ of the low molecular weight component (shaded portion) having a peak intensity of 20% or less is assumed to be 1, and the molecular weight distribution and viscosity of the shaded portion are assumed to be 1. From the data, the equation g ′ (M) = [η
_branch ] (M) / [η _linear ] (M) = [η _branch ]
(M) / K _linear × Find the coefficients K and α in M ^linear . When there is no measurement point at the peak intensity of 20%, the measurement point closest to the peak intensity of 20% is adopted to define the hatched portion in FIG. 7, and the coefficients K and α are obtained.

In FIG. 7, the molecular weight corresponding to the peak intensity of 20% is 5,000, and the branching parameter g 'of the low molecular weight component below this is 1. The measured viscosity [η _branch ] of the low molecular weight component in the range of 5,000 to 50,000, and the measured molecular weight of 5,000
The viscosity [η _linear ] is calculated using the molecular weight distribution in the range of from 50,000 to 50,000 and the coefficients K and α determined above. From the ratio of the actually measured viscosity [η _branch ] to the calculated viscosity [η _linear ], the branch index g ′ of the low-molecular-weight polymer component having a molecular weight of 50,000 or less in the present invention is obtained.

In FIG. 7, a straight line [η is drawn by assuming that the components having a molecular weight of 5,000 or less have a linear structure.
_linear ] and the measured viscosity [η _branch ] are plotted with “+”, and the calculated branch index g ′ is plotted with “0”.

Since the branch index g 'and Jimstock Mayer's branch index g show a good correlation,
In some cases, the ratio of the intrinsic viscosity of the branched polymer having a branched structure [η _branch ] to the intrinsic viscosity of the linear polymer having a linear structure having the same molecular weight distribution as the branched polymer [η _liner ] [η _liner ] [ η _branch ] / [η _linear ]
, The branch index g may be directly calculated.

The binder resin component of the toner of the present invention is THF.
In a molecular weight distribution of gel permeation chromatography (GPC) measured by a soluble component, a molecular weight of 20
It is preferable that the low molecular weight component having a molecular weight of less than 50,000 having a main peak in a region of 100,000 to 30,000 and a high molecular weight component having a molecular weight of 50,000 or more having a subpeak or a shoulder in a region having a molecular weight of 100,000 or more.

It is preferable that the binder resin component has a main peak in a region having a molecular weight of 2,000 to 30,000 and a subpeak in a region having a molecular weight of 200,000 or more (more preferably, 300,000 or more).

In the present invention, the molecular weight distributions of the binder resin component and the wax described below are measured by GPC (gel permeation chromatography) under the following conditions.

<GPC Measurement Conditions for THF-Soluble Content of Resin Component> Apparatus: GPC-150C (manufactured by Waters) Column: KF801-7 (manufactured by Shodex) Seven consecutive temperatures: 40 ° C. Solvent: THF flow rate: 1 .0 ml / min. Sample: 0.1 m of a sample having a concentration of 0.05 to 0.6% by weight
l injection

<GPC Measurement Conditions for Wax> Apparatus: GPC-150C (manufactured by Waters) Column: Duplex of GMH-HT (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (0.1% ionol added) ) Flow rate: 1.0 ml / min. Sample: 0.4 ml of 0.15% by weight sample is injected

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, the molecular weight of the wax is calculated by conversion using a conversion formula derived from the Mark-Houwink viscosity formula.

The weight average molecular weight (M) of the resin composition of the present invention
w) / number average molecular weight (Mn) ratio (Mw / Mn) is 3
It is preferably greater than zero. When Mw / Mn is 30 or less, it is difficult to sufficiently satisfy low-temperature fixability and offset resistance. More preferably, Mw / Mn is 35 or more.

By controlling the molecular structure of each component in the resin composition of the present invention as described above, good durability can be maintained without impairing the developing characteristics even when Mw / Mn is increased. In particular, when applied to a toner in which an additive having a high specific gravity such as magnetic fine particles is added to a resin composition having a bipolar molecular weight distribution, a remarkable effect is exhibited.

As a method for producing the binder resin component of the present invention, a high molecular weight polymer and a low molecular weight polymer are separately synthesized by a solution polymerization method, then they are mixed in a solution state, and then the solvent blend is removed. Method, a dry blending method in which the mixture is melt-kneaded by an extruder, etc., and a low-molecular-weight polymer obtained by a solution polymerization method or the like is dissolved in a monomer for constituting a high-molecular-weight polymer, and suspension polymerization is performed. , Washing with water and drying to obtain a binder resin component. However, with the dry blend method, uniform dispersion,
There is a problem in terms of compatibility, and although the two-stage polymerization method has many advantages such as uniform dispersibility, it is difficult to increase a low molecular weight component to a high molecular weight component or more. In the presence of a low molecular weight component, not only is it very difficult to synthesize a sufficient high molecular weight component desired in the present invention, but also there are problems such as unnecessary low molecular weight components being by-produced. The solution blending method is most suitable for application to the present invention.

As a method for synthesizing the low molecular weight component of the binder resin component of the present invention, the second monomer is added in the presence of a polymer in which a chain transfer reaction-prone group is contained in a repeating monomer unit or terminal group. A chain transfer method for performing radical polymerization; a polymer initiator method for polymerizing a second monomer using a polymer having a repeating unit or a terminal group as an initiator in a polymer; a radiation grafting method by irradiation with radiation; Chemical reaction method; a known method such as an improper or binding reaction method using a condensation reaction. By adjusting the amount of the initiator and the reaction temperature, a low-molecular-weight polymer can be easily obtained under mild conditions, and a chain transfer method using solution polymerization, which can utilize a difference in radical chain transfer depending on the solvent, is particularly preferable. Specifically, after the prepolymer is polymerized, hydrogen is extracted from the prepolymer by using an initiator having excellent hydrogen abstraction ability, a polymer radical is generated, and graft polymerization of the second monomer is started from the radical. The method is preferred.

It is effective to use a peroxide having the following structure in the molecule of the polymerization initiator as the polymerization initiator having excellent hydrogen abstracting ability.

[0055]

[Outside 5]

Specific examples of the polymerization initiator having such a structure include 1,1-bis (tert-butylperoxy) cyclohexane and 1,1-bis (tert-butylperoxy) 3,3,5- Trimethylcyclohexane,
2,2-bis (tert-butylperoxy) octane, di-tert-butime peroxide, tert-
Butyl cumyl peroxide, 2,5-dimethyl-2,
5-di (tert-butylperoxy) hexane, te
tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxypivalate, tert-butyl peroxy neodecanoate, tert-butyl peroxy 2-ethylhexanoate, tert-butyl pert Oxy 3,5,5-trimethyl hexanoate, tert-butyl peroxy laurate, tert-butyl peroxy benzoate, di-tert-butyl peroxy isophthalate,
tert-butyl peroxyisopropyl carbonate and the like.

Of the above polymerization initiators, when decomposed to generate free radicals, it is difficult to form a crosslinked structure,
Bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane, di-tert-butyl peroxide, tert-butylcumyl peroxide and the like are preferred.

These polymerization initiators are used alone or in combination of two or more. In order to control a desired molecular structure, 0.2 parts by weight of the prepolymer is required.
These polymerization initiators are added together with the second monomer in the range of ５5 parts by weight. When the polymerization reaction proceeds in the presence of the second monomer, the polymerization temperature is set at -10 ° C to + 20 ° C, more preferably -5 ° C to + 10 ° C, from the decomposition temperature at which the polymerization initiator obtains a half-life of 1 minute. It is preferable to adjust the range.

When the low molecular weight component of the binder resin component of the present invention is a combination of a monomer to be a styrene-based copolymer or a styrene-acrylic copolymer described below, low-temperature fixing can be achieved and an initiator can be obtained. In the sense of minimizing the amount used and minimizing the effect of the initiator residue on the charging characteristics,
The prepolymer may be polymerized under pressure.

On the other hand, it is preferable to add the second monomer so that the content of the acrylic component is higher than the monomer constituting the prepolymer. By doing this,
Not only are the storability and low-temperature fixability of the toner or developer highly satisfactory, but also the development characteristics are improved.

The second monomer is the prepolymer 100
It is preferable to add in the range of 5 to 50 parts by weight with respect to parts by weight. When the amount of the second monomer is less than 5 parts by weight,
The crosslinking reaction between polymer radicals generated by hydrogen abstraction is promoted, the crosslinking density increases, and the low-temperature fixability decreases. When the amount is more than 50 parts by weight, the generation of by-products such as oligomers is promoted, which adversely affects the storage stability and charging characteristics of the toner or developer and may cause a problem in matching with the image forming method.

The method for synthesizing the high molecular weight component of the binder resin component of the present invention includes an emulsion polymerization method and a suspension polymerization method.

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-phase polymerization initiator. This method makes it easy to control the heat of reaction,
Since the phase in which the polymerization is carried out (the oil phase composed of the polymer and the monomer) is different from the aqueous phase, the termination reaction rate is low, and as a result, the polymerization rate is high and a polymer having a high degree of polymerization is obtained. Furthermore, the polymerization process is relatively simple, and the polymerization product is fine particles, so that it is easy to mix with a colorant, a charge control agent, and other additives in the production of a toner. Therefore, there is an advantage in 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 remove the polymer. To avoid this inconvenience, suspension polymerization is advantageous.

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 the polymerization section. The polymerization temperature is suitably from 50 to 95 ° C, but should be appropriately selected depending on the initiator used and the intended polymer.

As the high molecular weight component of the binder resin used in the present invention, in order to achieve the object of the present invention, it is preferable to use a polyfunctional polymerization initiator having a polyfunctional structure as exemplified below.

Specific examples of the polyfunctional polymerization initiator include:
1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,3-bis- (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-
2,5- (t-butylperoxy) hexane, 2,5-
Dimethyl-2,5-di- (t-butylperoxy) hexyne-3, tris- (t-butylperoxy) triazine, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t -Butyl peroxybutane, 4,4
-Di-t-butylperoxyvaleric acid-n-
Butyl ester, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate, di-t-butylperoxytrimethyladipate, 2,2-bis- (4,4-di-t-butyl Multifunctional polymerization having a functional group having a polymerization initiating function such as two or more peroxide groups in one molecule such as peroxycyclohexyl) propane, 2,2-t-butylperoxyoctane and various polymer oxides An initiator; and a polymerization initiation function such as a peroxide group in one molecule such as diallyl peroxydicarbonate, t-butyl peroxymaleic acid, t-butyl peroxyallyl carbonate and t-butyl peroxyisopropyl fumarate. Selected from polyfunctional polymerization initiators having both a functional group having a polymer and a polymerizable unsaturated group It is.

Of these, preferred are 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, di-t-butyl Peroxyhexahydroterephthalate, di-t-butylperoxyazelate and 2,2-bis- (4,4-di-t-butylperoxycyclohexyl) propane, and t-butylperoxyallyl carbonate.

The polyfunctional polymerization initiator is preferably used in an amount of 0.05 to 5 parts by weight based on 100 parts by weight of the monomer.

These polyfunctional polymerization initiators are preferably used in combination with a monofunctional polymerization initiator in order to satisfy various performances required for a resin composition used for a toner. In particular, the use of a monofunctional polymerization initiator having a decomposition temperature of a half-life of 10 hours lower than the decomposition temperature for obtaining a half-life of 10 hours of the polyfunctional polymerization initiator makes the development characteristics of the toner more preferable. Be improved.

Specifically, organic peroxides such as di-t-butyl peroxide, dicumyl peroxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate and t-butyl peroxybenzoate Azo and diazo compounds such as azobisisobutyronitrile and diazoaminoazobenzene can be used.

These monofunctional polymerization initiators may be added to the monomer at the same time as the polyfunctional polymerization initiator. However, in order to maintain the initiator efficiency of the polyfunctional polymerization initiator properly, It is preferable to add the compound after the half-life of the polyfunctional polymerization initiator has elapsed under any polymerization conditions. The monofunctional polymerization initiator is preferably used in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the monomer.

The high molecular weight polymer component of the binder resin component used in the present invention is preferably polymerized in the presence of a crosslinking monomer as exemplified below in order to achieve the object of the present invention.

As the crosslinkable monomer, a monomer having two or more polymerizable double bonds is mainly used.
Specific examples include aromatic divinyl compounds (eg, divinylbenzene, divinylnaphthalene, etc.); diacrylate compounds linked by an alkyl chain (eg, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4 -Butanediol diacrylate, 1,5-pentanediol acrylate, 1,6-
Hexanediol diacrylate, neopentyl glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); diacrylate compounds linked by an alkyl chain containing an ether bond (for example, diethylene glycol diacrylate, triethylene glycol diacrylate) Acrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and methacrylate in place of the acrylate of the above compound); including an aromatic group and an ether bond Diacrylate compounds linked by a chain (for example, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propanediakurea , Polyoxyethylene (4) -
2,2-bis (4-hydroxyphenyl) propane diacrylate and those obtained by replacing the acrylate of the above compound with methacrylate; further, polyester type diacrylate compounds [for example, trade name MANDA (Nippon Kayaku)] ]. As multifunctional crosslinking agents, pentaerythritol acrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate, and acrylates of the above compounds to methacrylate Alternatives; triallyl cyanurate, triallyl trimellitate; and the like.

When these crosslinkable monomers are used in an amount of 1% by weight or less with respect to 100% by weight of the other monomer components, not only satisfactory low-temperature fixability and anti-offset property are satisfied, but also the storage of toner. The performance is also improved.

Among these crosslinking monomers, those preferably used include aromatic divinyl compounds (particularly divinylbenzene) and diacrylate compounds linked by a chain containing an aromatic group and an ether bond. It is preferable to use it in the range of 0.001 to 0.05% by weight based on 100% by weight of the monomer component. As a result, even when the particle size of the toner is reduced, the developing characteristics of the toner or developer under each environment are stabilized, and the durability is improved. Further, it shows good matching with a wax component described later.

The polymer side component of the binder resin component of the present invention includes:
A crosslinking unit may be promoted by including a monomer unit having at least one of a carboxyl group, a carboxylate group, and a carboxylic anhydride group and undergoing a hot-melt kneading step in the production of the toner. In particular, when a binder resin having a low melt viscosity is used, each component constituting the toner can enjoy a stronger and more uniform shearing force than before, due to the thickening effect of the crosslinking reaction, so that the synergistic effects of each component can be obtained. The dispersibility of the components is improved, and the stabilization of the developing property is realized.
It also shows good matching with the wax component described below.

In order to exhibit a predetermined effect by the crosslinking reaction, it is preferable that the above-mentioned carboxyl group capable of forming a crosslinking bond is contained within a range that does not impair the developing characteristics. Specifically, it is preferable to adjust the acid value of the polymer side component constituting the binder resin component of the toner of the present invention so as to be 0.5 to 30.

The polymer component having a polar group capable of forming a crosslink bond includes a carboxyl group, a carboxylic anhydride group,
Polymers containing at least one of the carboxylic acid groups show the best reactivity. Examples of the carboxyl group-containing monomer for synthesizing a vinyl polymer include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid and α- or β-alkyl derivatives thereof; fumaric acid, maleic acid, Examples include unsaturated dicarboxylic acids such as citraconic acid and monoester derivatives thereof, and maleic anhydride. Such a monomer can be used alone or as a mixture and copolymerized with another monomer to produce a desired polymer. Among them, it is particularly preferable to use a monoester derivative of an unsaturated dicarboxylic acid.

Monomers containing a carboxyl group which can be preferably used in the present invention include monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate,
Monoesters of α, β-unsaturated dicarboxylic acids such as monophenyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monophenyl fumarate, etc .; monobutyl n-butenylsuccinate, monomethyl n-octenylsuccinate, Monoesters of alkenyl dicarboxylic acids such as monoethyl n-butenylmalonate, monomethyl n-dodecenylglutarate, monobutyl n-butenyladipate; monomethyl phthalate, monoethyl phthalate, monobutyl phthalate, etc. And monoesters of aromatic dicarboxylic acids.

The carboxy group monomer described above is used in an amount of 1 to 1 with respect to all the monomers constituting the polymer side of the binder resin.
30% by weight, preferably 3 to 20% by weight may be added.

The reason that the monoester monomer of dicarboxylic acid is selected as described above is that it is not appropriate to use an acid monomer having high solubility in an aqueous suspension in the suspension polymerization. This is because it is preferable to use the compound in the form of an ester having low solubility.

In the present invention, the carboxylic acid groups and carboxylic acid ester sites in the copolymer obtained by the above method can be saponified by alkali treatment.

It is preferred that the carboxylic acid group or carboxylic acid ester moiety is changed to a polar functional group by reacting with a cation component of an alkali. This is because even if the polymer side component of the binder resin contains a carboxyl group that reacts with the metal-containing compound, the efficiency of the cross-linking reaction is reduced if the carboxyl group is in an anhydrous (ie, ring-closed) state. .

This alkali treatment may be carried out after the production of the binder resin, by introducing it as an aqueous solution into the solvent used during the polymerization and stirring. Examples of the alkali that can be used include hydroxides of alkali metals and alkaline earth metals such as Na, K, Ca, Li, Mg, and Ba; Zn, Ag, P
hydroxides of transition metals such as b and Ni; hydroxides of quaternary ammonium salts such as ammonium salts, alkylammonium salts and pyridinium salts. As a particularly preferred example,
NaOH and KOH are mentioned.

In the present invention, the saponification reaction does not need to be carried out over all of the carboxylic acid groups and carboxylic acid ester sites in the copolymer. I just need to change.

The amount of the alkali used in the saponification reaction is difficult to determine unconditionally depending on the type of the polar group in the binder resin, the dispersion method, the type of the constituent monomers, and the like. What is necessary is just 5 times equivalent. 0.
If the amount is less than 02 equivalents, the saponification reaction is not sufficient,
The number of polar functional groups generated by the reaction decreases, and as a result, the subsequent crosslinking reaction tends to be insufficient. On the other hand, when the amount exceeds 5 times equivalent, the functional group such as a carboxylic acid ester site may be adversely affected by hydrolysis of the ester, formation of a salt by a saponification reaction, or the like.

When an alkali treatment of 0.02 to 5 times equivalent of the acid value is performed, the residual cation ion concentration after the treatment is 5 to 5.
It is contained between 1000 ppm and can be preferably used to regulate the amount of alkali.

To the toner of the present invention, a metal-containing organic compound may be added to promote crosslinking between polymer chains of the resin composition during the production of the toner. Those containing a metal compound as a ligand or counter ion give excellent results.

Among the organic compounds forming a ligand or a counter ion with a metal ion, those having the above properties include salicylic acid, salicylamide, salicylamine,
Salicylaldehyde, salicylosalicylic acid, di-ter
Salicylic acid such as t-bitylsalicylic acid and derivatives thereof; β- such as acetylacetone and propionacetone;
Diketones; low-molecular carboxylate salts such as acetate and propionic acid;

The monomers for obtaining the binder resin used in the toner of the present invention include the following vinyl monomers.

Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,
4-dichlorostyrene, p-ethylstyrene, 2,4-
Dimethylstyrene, pn-butylstyrene, p-te
rt-butylstyrene, pn-hexylstyrene, p
-N-octylstyrene, pn-nonylstyrene, p
Styrene derivatives such as -n-decylstyrene, pn-dodecylstyrene; ethylene, propylene, butylene,
Unsaturated monoolefins such as isobutylene; unsaturated polyenes such as butadiene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyls such as vinyl acetate, vinyl propionate and vinyl benzoate. Esters: methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-methacrylate
-Octyl, dodecyl methacrylate, methacrylic acid-2
Α-methylene aliphatic monocarboxylic esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate;
Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole,
N-vinyl compounds such as N-vinylpyrrolidone; vinylnaphthalenes; acrylic acid derivatives or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide. These vinyl monomers are used alone or in combination of two or more.

Among these, a combination of monomers that results in a styrene-based copolymer and a styrene-acrylic copolymer is preferred.

The addition of a low molecular weight wax to the toner of the present invention is one of the preferred embodiments of the present invention.

Examples of the low molecular weight wax applicable to the present invention include wax-like substances such as polypropylene, polyethylene, microcrystalline wax, carnauba wax, sasol wax, paraffin wax, and oxides and graft-modified products thereof. . These can be used alone or in combination.

The weight average molecular weight of these low molecular weight waxes is 30,000 or less, preferably 10,000 or less. The addition amount is preferably 1 to 20 parts by weight based on 100 parts by weight of the binder resin.

Further, the low molecular weight wax used in the present invention has the following general formula: RY [R: a hydrocarbon group having a weight average molecular weight of 3000 or less as determined by gel permeation chromatography.

Y: represents a hydroxyl group, a carboxyl group, an alkyl ether group, an ester group, or a sulfonyl group. ], The object of the present invention can be achieved to a high degree by containing 60% by weight or more, preferably 70% by weight or more. The matching with the binder resin is very good.

Specific examples of the compounds include (A) CH ₃ (CH ₂ ) _n CH ₂ OH (n = about 20 to about 200) (B) CH ₃ (CH ₂ ) _n CH ₂ COOH (n = about ₂₀ ) 20
(C) CH ₃ (CH ₂ ) _n CH ₂ OCH ₂ (CH ₂ ) _m
CH ₃ (n = about 20 to about 200, m = 0 to about 100) (D) CH ₃ (CH ₂ ) _n CH ₂ COOH (CH ₂ ) _m
CH ₃ (n = about 20 to about 200, m = 0 to about 100) (E) CH ₃ (CH ₂ ) _n CH ₂ OSO ₃ H (n = about 2
0 to about 200). These compounds are derivatives of the compound (A), and the main chain is a linear saturated hydrocarbon. As long as the compound is derived from the compound (A), those other than those shown in the above examples can also be used.

The above compound has a number average molecular weight (Mn) of 20.
0 to 2000, weight average molecular weight (Mw) 400 to 30
Mw / Mn is preferably 3.0 or less. By having such a molecular weight distribution, the toner can have preferable physical characteristics. When the molecular weight is smaller than the above range, the composition is susceptible to thermal and mechanical effects excessively, and causes problems in offset resistance and storage stability. When the molecular weight is larger than the above range, the effect of adding the compound is reduced.

It is preferable that these low molecular weight waxes are previously added to and mixed with the binder resin in the production of the toner. In particular, a method is preferred in which the low molecular weight wax component and the high molecular weight polymer are preliminarily dissolved in a solvent during the production of the binder, and then mixed with the low molecular weight polymer solution. By preliminarily mixing the low molecular weight wax component and the high molecular weight component, phase separation in the micro region is reduced, the high molecular weight component is not re-aggregated, and a good dispersion state with the low molecular weight component is obtained.

The solid concentration of the polymer solution is determined by the dispersion efficiency,
In consideration of prevention of deterioration of the resin at the time of stirring, operability, etc., 5 to 70
Preferably, the preliminary solution of the high molecular weight polymer component and the low molecular weight wax component is 5 to 60% by weight, and the low molecular weight polymer solution is 5 to 70% by weight.

The method for dissolving or dispersing the high molecular weight polymer component and the low molecular weight wax component is performed by stirring and mixing.
A batch type or a continuous type may be used.

The method of mixing the low-molecular-weight polymer solution is to add 10 to 1000 parts by weight of the low-molecular-weight polymer solution to the solid content of the preliminary solution and to carry out stirring and mixing. But it can be continuous.

As the organic solvent used when mixing the solution of the resin composition according to the present invention, for example, benzene, toluene,
Xylol, Solvent Naphtha No. 1, Solvent Naphtha No. 2, Solvent Naphtha No. 3, Cyclohexane, ethylbenzene, hydrocarbon solvents such as Solvesso 100, Solvesso 150, mineral spirits; methanol, ethanol, iso-propyl alcohol, n-butyl alcohol; alcohol solvents such as sec-butyl alcohol, iso-butyl alcohol, amyl alcohol, and cyclohexanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate, n-butyl acetate, and cellosolve acetate Solvents: ether solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and methyl carbitol. Among these, aromatic, ketone or ester solvents are preferred. These may be used as a mixture.

It is preferable to remove the organic solvent by heating the organic solvent solution of the polymer, removing 10 to 80% by weight of the organic solvent under normal pressure, and then removing the remaining solvent under reduced pressure. At this time, the organic solvent solution is preferably kept at a temperature not lower than the boiling point of the used organic solvent and not higher than 200 ° C. Below the boiling point of the organic solvent, not only is the efficiency at the time of solvent distillation low, but also unnecessary shearing force is applied to the polymer in the organic solvent, and the redispersion of each constituent polymer is promoted, and in a micro state, Tends to cause phase separation. If the temperature exceeds 200 ° C., the depolymerization of the polymer tends to proceed, and not only the generation of oligomers due to molecular cleavage, but also the incorporation of residual monomers into the product resin due to the generation of monomers tends to occur.

The resin composition obtained by the above production method has excellent compatibility between the low molecular weight polymer and the high molecular weight polymer, not to mention the dispersibility of the low molecular weight wax component.
Significant improvements are made compared to conventional methods.

The glass transition temperature (Tg) of the resin composition contained in the toner of the present invention is preferably adjusted to 50 to 70 ° C. If the Tg is lower than 50 ° C., it tends to cause deterioration of the toner or developer in a high-temperature atmosphere and offset during heating and fixing. If the temperature exceeds 70 ° C., the fixing property is reduced.

In the present invention, the Tg of the resin is measured using a differential thermal analyzer (DSC analyzer), for example, DSC-7 (manufactured by PerkinElmer).

The measurement sample is 5 to 20 mg, preferably 10
Weigh the mg precisely. This is put in an aluminum pan, and the measurement is performed at a temperature rising rate of 10 ° C./min under normal temperature and normal humidity using an empty aluminum pan as a reference at a measurement temperature range of 30 ° C. to 200 ° C. In this heating process, the temperature is 40 to 10
An endothermic peak of the main peak in the range of 0 ° C. is obtained. At this time, the temperature corresponding to the intersection of the straight line passing through the middle point of the baseline before and after the endothermic peak and the differential heat curve is defined as the glass transition temperature.

In the toner of the present invention, it is preferable to add a charge control agent in order to improve charge stability and developability.

Specific examples of the positive charge control agent include nigrosine, an azine dye having an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), and a basic dye (for example, CI Basic Yellow 2). (C.I.4100
0), C.I. I. Basic Yellow 3, C.I. I. Basic Red 1 (CI. 45160), C.I. I.
Basic Red 9 (CI. 42500), C.I.
I. Basic Violet 1 (CI. 4253)
5), C.I. I. Basic Violet 3 (C.I.
I. 42555), C.I. I. Basic Violet 10 (CI. 45170), C.I. I. Basic Violet 14 (CI. 42510), C.I. I. Basic Blue 1 (CI. 42025), C.I.
I. Basic Blue 3 (CI51005),
C. I. Basic Blue 5 (CI. 4214)
0), C.I. I. Basic Blue 7 (CI.42
595), C.I. I. Basic Blue 9 (CI.
52015), C.I. I. Basic Blue 24 (C.I.
I. 52030), C.I. I. Basic Blue 25
(CI.52025), C.I. I. Basic Blue 26 (CI.44025) C.I. I. Basic Green 1 (CI. 42040), C.I. I. Basic Green 4 (C.I. 42000), lake pigments of these basic dyes (as the lacating agent, phosphotungstic acid, phosphomolybdic acid, phosphomolybdic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanic acid) , Ferrocyanide, etc.), C.I. I. Solvent Black 3 (CI. 26150), Hansa Yellow G (CI. 11680), C.I. I. Maudrant Black 11, C.I. I. Pigment Black 1.

For example, polyamide resins such as quaternary ammonium salts such as benzolmethyl-hexadecyl ammonium chloride and decyl-trimethyl ammonium chloride, vinyl polymers having an amino group, and condensation polymers having an amino group can be used. Preferred are nigrosine, quaternary ammonium salts, triphenylmethane-based nitrogen-containing compounds, and polyamides.

As the negative charge control agent, Japanese Patent Publication No. 41-20 / 1972
No. 153, JP-B-42-27596, JP-B-44-6397 and JP-B-45-26478, and metal complexes of monoazo dyes described in JP-A-50-133338. Nitroamine acids and salts thereof or C.I. I. Dyes and pigments such as 14645, JP-B-55-42752, JP-B-58-4
No. 1508, JP-B-58-7384, JP-B-59-7385, and the like. Zn, Al, Co of salicylic acid, naphthoic acid and dicarboxylic acid
Examples thereof include metal complexes such as Cr and Fe, sulfonated copper phthalocyanine pigments, nitro groups, styrene oligomers into which halogens have been introduced, and chlorinated paraffins.

Preferably, the negative charge control agent is a compound selected from the group consisting of a metal complex of salicylic acid, a metal complex of naphthoic acid, a metal complex of dicarboxylic acid and a metal complex of a derivative thereof.

From the viewpoint of dispersibility, an azo metal complex represented by the following [I] or a basic organic acid metal complex represented by the following [II] is particularly preferred.

[0117]

[Outside 6] [Wherein M represents a coordination center metal, and Cr, C
o, Ni, Ni, Mn and Fe. Ar is an aryl group, such as a phenyl group and a naphthyl group;
It may have a substituent. Examples of the substituent in this case include a nitro group, a halogen group, a carboxyl group, an anilide group, an alkyl group having 1 to 18 carbon atoms, and an alkoxy group. X, X ', Y, Y' are -O-, -CO-, -NH
-, -NR- (R is an alkyl group having 1 to 4 carbon atoms). Y ⁺ represents hydrogen, sodium, potassium, ammonium or aliphatic ammonium.

[0118]

[Outside 7] [Wherein, M represents a coordination center metal, and Cr having a coordination number of 6,
Co, Ni, Mn and Fe. A is

[0119]

[Outside 8] (Which may have a substituent such as an alkyl group),

[0120]

[Outside 9] (X is a hydrogen atom, a halogen atom or a nitro group) and

[0121]

[Outside 10] (R is a hydrogen atom, an alkyl or alkenyl group of C ₁ -C ₁₈₎ represent. Y ⁺ is hydrogen, sodium, potassium,
Ammonium and aliphatic ammonium. Z
Is -O- or

[0122]

[Outside 11] Is shown. ]

Specific examples of the azo metal complex [I] and the basic organic acid metal complex [II] are shown below.

[0124]

[Outside 12]

[0125]

[Outside 13]

[0126]

[Outside 14]

[0127]

[Outside 15]

[0128]

[Outside 16]

These metal complexes may be used alone or in combination of two or more.

When the above-mentioned metal complex is used as a charge controlling agent, the addition amount of the metal complex is maintained as described above, while maintaining the good triboelectricity, the developing power is reduced due to the contamination of the developing sleeve surface by the charge controlling agent, and the environmental stability is reduced. 100 parts by weight of the binder resin to minimize the adverse effects
An addition amount of 0.1 to 5 parts by weight is preferred.

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

The inorganic fine powder used in the present invention includes:
For example, silica fine powder, titanium oxide fine powder, alumina fine powder and the like can be mentioned. Among them, the specific surface area by nitrogen adsorption measured by the BET method is 30 m ² / g or more (particularly 50 to 40 m ² / g).
An inorganic fine powder in the range of 0 m ² / g) gives good results. Inorganic fine powder 0.01 to 100 parts by weight of toner
It is good to use 8 parts by weight, preferably 0.1 to 5 parts by weight.

The inorganic fine powder used in the present invention may be, if necessary, silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, It is also preferable that the treatment is carried out with a treating agent such as a silane coupling agent having a group or another organosilicon compound, or in combination with these treating agents.

Other additives include lubricants such as Teflon powder, zinc stearate powder and polyvinylidene fluoride powder (polyvinylidene fluoride is preferred); cerium oxide, silicon carbide and strontium titanate. Abrasives (preferably strontium titanate); fluidity-imparting agents such as titanium oxide and aluminum oxide (particularly preferably hydrophobic); anti-caking agents; carbon black, zinc oxide, antimony oxide, tin oxide A small amount of a conductivity-imparting agent or white fine particles or black fine particles of opposite polarity can also be used as a developability improver.

Further, when the toner of the present invention is used as a two-component developer, it is used by mixing with carrier particles. In this case, the mixing ratio between the toner and the carrier particles is 0.1 to 50% by weight, preferably 0.1 to 50% by weight as the toner concentration.
The content is preferably 5 to 10% by weight, more preferably 3 to 5% by weight.

As the carrier particles that can be used in the present invention, known carrier particles can be used. For example, powders having magnetism such as iron powder, ferrite powder, and nickel powder, and powders obtained by treating the surfaces thereof with a fluorine-based resin, a vinyl-based resin, a silicon-based resin, or the like can be given.

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

These magnetic materials have an average particle size of 0.1 to 2 μm.
m, preferably 0.1 to 0.5 μm.
The amount contained in the magnetic 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.

When the magnetic characteristic at the application of 10K Oersted is 2
0-250 eluted, saturation magnetization 50-200 emu
/ G and a residual magnetization of 2 to 20 emu / g are preferred.

As the nonmagnetic colorant that can be used in the toner of the present invention, any suitable pigment or dye can be used.
Examples of the coloring agent include pigments such as carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengara, phthalocyanine blue, and indanthrene blue. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and are preferably added in an amount of 0.1 to 20 parts by weight, preferably 2 to 10 parts by weight based on 100 parts by weight of the resin. Dyes are used for similar purposes. For example, there are azo dyes, anthraquinone dyes, xanthene dyes, methine dyes and the like.
The addition amount of 1 to 20 parts by weight, preferably 0.3 to 3 parts by weight is good.

To prepare the toner for developing an electrostatic image of the present invention, a binder resin, a metal compound, a pigment or dye as a colorant, a magnetic material, a charge control agent, and other additives as necessary are added. After sufficiently mixing with a mixer such as a Henschel mixer or a ball mill, melting using a hot kneader such as a heating roll, kneader or extruder,
The toner of the present invention can be obtained by kneading and kneading to disperse or dissolve a metal compound, a pigment, a dye, and a magnetic substance in a binder resin, solidify by cooling, and then pulverize and classify.

Further, if necessary, desired additives are sufficiently mixed by a mixer such as a Henschel mixer to obtain the toner for electrostatic charge development of the present invention.

Next, the image forming method of the present invention will be described with reference to FIG. An example of an apparatus such as a copying machine or a printer for performing the image forming method of the present invention is an electrophotographic apparatus shown in FIG. 6, and a developing unit 60 contains a toner 61 of the present invention. The toner is a magnetic toner or a non-magnetic toner. In an image forming apparatus other than the apparatus shown in FIG. 6, a developing unit using a two-component developer having a toner and a carrier may be used. A charging unit (for example, a charging roller, a charging brush, a charging blade, or the like, which is a contact charging unit) 62 to which a voltage is applied by the bias applying unit 62a is used by a photosensitive member (for example, an OPC photosensitive drum, amorphous silicone, or a polycrystalline photosensitive drum). )
The surface of the photoconductor 63 is charged, and an electrostatic charge image is formed on the photoconductor 63 by exposure (for example, laser light or light from a halogen lamp) 64. Toner coating blades (eg, elastic blades,
The electrostatic image is developed with the magnetic toner 61 housed in the developing means 60 having a developing sleeve 65 containing a magnetic blade 64 and a magnetic field generating means (for example, a magnet). For development, a regular development method or a repetitive development method is used. In the developing section, an alternating bias, a pulse bias and / or a DC bias are applied to the developing sleeve 65 by a bias applying means 66 as necessary. When the transfer material P is conveyed and reaches the transfer portion, a voltage is applied by the bias applying means 68. Transfer means (for example,
The toner image on the surface of the photoconductor 63 is charged by being charged while being pressed from the back surface (the side opposite to the photoconductor 63 side) of the transfer material P by a transfer roller, a transfer belt, etc. 67.
Transfer electrostatically to the top. In some cases, the toner image on the photoconductor 63 may be transferred to an intermediate transfer member (eg, an intermediate transfer drum, an intermediate transfer belt, etc.), and the toner image may be transferred from the intermediate transfer member to the transfer material P. .

The toner image on the transfer material P separated from the photoreceptor 63 is fixed to the transfer material P by a heating / pressing unit (for example, a heating / pressing roller fixing unit) 69. The toner remaining on the photoconductor 63 after the transfer step is cleaned by a cleaning unit (for example, a cleaning blade, a cleaning roller, a cleaning brush, etc.) 70 as necessary.
3 is removed from the surface. Photoconductor 63 after cleaning
Is repeated from the charging step by the charging means 62 again.

The photosensitive member 63, which is an electrostatic image carrier, generally has a photosensitive layer and a conductive substrate, and rotates in the direction of the arrow.
Developing sleeve 6 having non-magnetic cylinder as toner carrier
Reference numeral 5 rotates in the developing section so as to advance in the same direction as the photoconductor 63. Inside the developing sleeve 65, a multi-pole permanent magnet (magnet roll) as a magnetic field generating means is fixed and supported. The magnetic toner 61 housed inside the developing means 60 is applied to the surface of the developing sleeve 65 by the application blade 64, and the toner particles generate triboelectric charges due to friction with the surface of the application blade 64 and / or the developing sleeve 65. Granted. The application layer 64 uniformly applies the toner layer (for example, a thickness of 10 to 300 μm) on the surface of the developing sleeve 65. In the developing section, for example, the AC bias f
A voltage of 4,000 Hz and Vpp of 500 to 3,000 V is applied.

When transferring the toner particles in the developing section,
The toner particles transfer to an electrostatic image due to the electrostatic force of the photoconductor surface and the action of an AC bias or a pulse bias.

Next, each member of the apparatus shown in FIGS. 1 to 3 used in the embodiment will be described below. 1 to 3, reference numeral 10 denotes an electrostatic image carrier (photosensitive drum).
1 denotes a charger (charging roll), 12 denotes a process cartridge, 13 denotes a cleaning unit, and 14 denotes a cleaning unit.
Denotes an exposure unit, 15 denotes a developer container, and 16 denotes a developer container.
Denotes a developer carrier (developing sleeve), 17 denotes a magnetic field generating means, 18 denotes an elastic layer thickness regulating member, 19 denotes a transfer means (transfer roll), 20 denotes a stay,
21 indicates a heating element, 21a indicates a heater substrate, and 2
1b shows a heating element, 21c shows a surface protective layer, 21b
d indicates a temperature sensor, 22 indicates a fixing film, and 23 indicates a fixing film.
Indicates a pressure roller, 24 indicates a coil spring, 25
Indicates a film end regulating flange, 26 indicates a power supply connector, 27 indicates a power cutoff member, 28 indicates an entrance guide, and 29 indicates an exit guide (separation guide).

FIG. 5 is a schematic sectional view of the process cartridge taken out of the image forming apparatus main body.
The process cartridge at least integrates the developing means and the electrostatic image holder into a cartridge, and the process cartridge is formed so as to be detachable from a main body of the image forming apparatus (for example, a copying machine, a laser beam printer, or the like).

In this embodiment, a developing means, a drum-shaped electrostatic image holder 10 (photosensitive drum), a cleaner having a cleaning blade 13, a primary charger (charging roller)
11 is an example of a process cartridge.

In the present embodiment, the developing means has a toner layer thickness regulating member and a magnetic toner T in a toner container, and the magnetic toner T is used. A predetermined electric field is formed between the sleeve and the sleeve, and the developing step is suitably performed.

[0151]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

Preparation Example 1 of Resin Composition 300 parts by weight of xylene were put into a synthetic glass autoclave of low molecular weight polymers (L-1) and (L-2), and the inside of the container was sufficiently stirred with nitrogen. After replacing with
It sealed and heated up to 200 degreeC.

A mixture of 88 parts by weight of styrene, 12 parts by weight of n-butyl acrylate, and 2 parts by weight of di-tert-butyl peroxide was added dropwise over 2.5 hours while maintaining the pressurized reflux state at the same temperature. After that, the mixture was held for 1 hour to complete the polymerization, thereby obtaining a low molecular weight polymer (L-1) solution.

A part of the polymer solution was taken out, dried under reduced pressure, and the obtained low molecular weight polymer (L-1) was analyzed. Mw = 8,300, Mn = 4,200,
The peak molecular weight PMw was 6,900, Tg was 61 ° C., and the polymer conversion was 98%. The branch index g ′ was 1.05.

Next, 400 parts by weight of the low-molecular-weight polymer (L-1) solution was put into a four-necked flask, and the inside of the vessel was sufficiently purged with nitrogen while stirring, and then the xylene reflux temperature (144 ° C.) ).

While maintaining the reflux state at the same temperature, styrene 1
7.2 parts by weight, 2.8 parts by weight of n-butyl acrylate,
And 1,1-bis (tert-butylperoxy) 3,
A mixture of 2 parts by weight of 3,5-trimethylcyclohexane (1 minute half-life temperature; 148 ° C.) was added dropwise over 4 hours, and the mixture was held for 1 hour to complete polymerization, and a low molecular weight polymer (L-2) solution I got

A part of this polymer solution was sampled and dried under reduced pressure. The obtained low molecular weight polymer (L-2) was analyzed, and it was found that Mw = 8,400 and Mn = 4,20.
0, PMw = 6,900, Tg = 57 ° C., and branching index g ′ = 0.85. At this time, the conversion of the polymer was 97%.

Synthesis of High Molecular Weight Polymer (H-1) 180 parts by weight of degassed water and 20 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol were charged into a four-necked flask, and 69 parts by weight of styrene and acrylic acid were added. 26 parts by weight of n-butyl, 5 parts by weight of monobutyl maleate, 0.005 parts by weight of divinylbenzene, and 2,2-bis (4,4-di-
A mixture of 0.1 part by weight of tert-butylperoxycyclohexyl) propane (10-hour half-life temperature; 92 ° C.) was added and stirred to form a suspension.

After the inside of the flask was sufficiently replaced with nitrogen,
The temperature was raised to 5 ° C. to initiate polymerization. After maintaining at the same temperature for 24 hours, 0.1 part by weight of benzoyl peroxide (10-hour half-life temperature; 72 ° C.) was further added. Furthermore,
The polymerization was completed by holding for 12 hours.

To the suspension after completion of the reaction, an aqueous NaOH solution equivalent to twice the acid value (AV = 8.0) of the obtained high molecular weight polymer (H-1) was added, and the mixture was stirred for 2 hours. Was.

The high molecular weight polymer (H-1) was separated by filtration, washed with water, dried, and analyzed.
n = 110,000, PMw = 1.1 million, Tg = 61 ° C, THF
The insoluble content was 2.3%, which is substantially not contained, and the degree of branching was g '= 1.22.

Preparation of Binder In a four-necked flask, 100 parts by weight of xylene, 25 parts by weight of the high molecular weight polymer (H-1), 3 parts by weight of low molecular weight polyethylene (Mw = 800), and a structural formula of CH ₃ (C
H ₂₎ 20~60CH ₂ higher alcohol composed mainly of component represented by OH (Mw900, Mn450) 7 parts by weight were charged, and stirred under reflux heated, was predissolved. After maintaining in this state for 12 hours, a uniform preliminary solution (Y-1) of the high molecular weight polymer (H-1), the low molecular weight polyethylene and the higher alkyl alcohol was obtained.

The Tg of the solid content in this pre-dissolved solution was 58 ° C.
Met.

On the other hand, the low molecular weight polymer (L-
260 parts by weight of the homogeneous solution of 2) was charged and refluxed.

After the above pre-dissolved solution (Y-1) and the low molecular weight polymer (L-2) solution were mixed under reflux, the solvent was distilled off, and the obtained resin was cold-rolled, solidified and pulverized. Thus, a resin composition for toner (I) was obtained. The obtained resin composition (I) is TH
The content of the F-insoluble component was less than 3% by weight.

When the molecular weight of the resin composition (I) was measured, it had peaks at a molecular weight of 7,500 and 900,000, a main peak at a molecular weight of 7,500, and Mw / Mn of 4
5.7. The Tg of the resin composition (I) was 57 ° C.

Further, when the thin section of the resin composition was observed with a video microscope (manufactured by Wilson), good dispersion was confirmed without reaggregation.

Preparation Example 2 of Resin Composition Synthesis of Low Molecular Weight Polymer (L-3) 400 parts by weight of the above low molecular weight polymer (L-1) solution was charged into a four-necked flask, and stirred in a container. Was sufficiently replaced with nitrogen, and then heated to the xylene reflux temperature.

While maintaining a reflux state at the same temperature, 4.2 parts by weight of styrene, 0.8 parts by weight of n-butyl acrylate,
And 1,1-bis (tert-butylperoxy) 3,
A mixture of 2 parts by weight of 3,5-trimethylcyclohexane was added dropwise over 4 hours, and then maintained for 1 hour to complete the polymerization, thereby obtaining a low molecular weight polymer (L-3) solution.

A part of the polymer solution was sampled and dried under reduced pressure to obtain a low molecular weight polymer (L-3).
Analysis showed that Mw = 8,300, Mn = 4,10
0, PMw = 6,900, Tg = 58 ° C., and branching index g ′ = 0.95. At this time, the conversion of the polymer was 98%.

Preparation of Binder In the same manner as in Preparation Example 1 of the resin composition, the pre-solution (Y-
After preparing 1), the low molecular weight polymer (L-3) solution 2
After 90 parts by weight were mixed under reflux, the solvent was distilled off, and the obtained resin was cold-rolled, solidified and pulverized to obtain a resin composition for toner (II). The obtained resin composition (II) is THF
The insoluble content was less than 3% by weight.

When the molecular weight of the resin composition (II) was measured, it had peaks at molecular weights of 7,500 and 880,000, the main peak was at 7,500, and Mw / Mn was 4
4.9. The Tg of the resin composition (II) was 58 ° C.

Production Example 3 of Resin Composition Synthesis of Low Molecular Weight Polymer (L-4) 400 parts by weight of the above low molecular weight polymer (L-1) solution was charged into a four-necked flask, and stirred in a container. Was sufficiently replaced with nitrogen, and then heated to the xylene reflux temperature.

While maintaining the reflux state at the same temperature, styrene 4
4 parts by weight, 6 parts by weight of n-butyl acrylate, and 1,
1-bis (tert-butylperoxy) 3,3,5-
After a mixture of 2 parts by weight of trimethylcyclohexane was added dropwise over 4 hours, the mixture was held for 1 hour to complete the polymerization, thereby obtaining a low molecular weight polymer (L-4) solution.

A part of this polymer solution was sampled and dried under reduced pressure, and the resulting low molecular weight polymer (L-4) was obtained.
Was analyzed, Mw = 8,400, Mn = 4,10
0, PMw = 6,900, Tg = 56 ° C., g ′ = 0.8
Nine. At this time, the conversion of the polymer was 98%.

Preparation of Binder In the same manner as in Preparation Example 1 of the resin composition described above, the pre-solution (Y-
After preparing 1), the low molecular weight polymer (L-4) solution 2
25 parts by weight were mixed under reflux. Thereafter, the solvent was distilled off, and the obtained resin was cold-rolled, solidified and pulverized to obtain a resin composition for toner (III). The obtained resin composition (II
In I), the content of the THF-insoluble component was less than 3% by weight.

When the molecular weight of the resin composition (III) was measured, it had peaks at 7,400 and 880,000,
The main peak is at a molecular weight of 7400, and Mw / Mn is:
45.2. Tg of the resin composition (III) is 56
° C.

Production Example 4 of Resin Composition Synthesis of high molecular weight polymer (H-2) 180 parts by weight of degassed water and 20 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol were charged into a four-necked flask, and then styrene was added. 77 parts by weight, 23 parts by weight of n-butyl acrylate, 0.001 part by weight of divinylbenzene, and 1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane (10-hour half-life temperature; 90 ° C.) ) 0.
One part by weight of the mixture was added and stirred to form a suspension.

After sufficiently replacing the inside of the flask with nitrogen, 8
The temperature was raised to 5 ° C. to initiate polymerization. After maintaining at the same temperature for 24 hours, 0.1 part by weight of benzoyl peroxide (10-hour half-life temperature; 72 ° C.) was further added. Furthermore,
The polymerization was completed by holding for 12 hours.

The high molecular weight polymer (H-2) was separated by filtration, washed with water, dried and analyzed.
n = 120,000, PMw = 750,000, Tg = 60 ° C., the THF-insoluble content was 1.0%, which was substantially not contained, and the branching index g ′ was 1.15.

Preparation of Binder In a four-necked flask, 100 parts by weight of xylene, 25 parts by weight of the high molecular weight polymer (H-2), 3 parts by weight of low molecular weight polyethylene (Mw = 800), and the structural formula CH ₃
7 parts by weight of a higher fatty acid represented by (CH ₂ ) ₄₈ COOH was added, and the mixture was heated, stirred under reflux, and preliminarily dissolved. This state is maintained for 12 hours, and the high molecular weight polymer (H-
2) and a homogeneous pre-dissolved solution (Y-2) of low molecular weight polyethylene and higher fatty acid was obtained.

The Tg of the solid content in this pre-dissolved solution was 55 ° C.
Met.

After mixing the above pre-dissolved solution (Y-2) and 260 parts by weight of the low molecular weight polymer (L-2) solution under reflux,
The solvent was distilled off, and the obtained resin was cold-rolled, solidified and pulverized to obtain a resin composition for toner (IV). The obtained resin composition (IV) had a THF-insoluble content of less than 3% by weight.

When the molecular weight of the resin composition (IV) was measured, it had peaks at a molecular weight of 7,800 and 690,000, a main peak at a molecular weight of 7,800, and Mw / Mn.
Was 39.2. Tg of the resin composition (IV) is 5
6 ° C.

Production Example 5 of Resin Composition Production of Binder In a four-necked flask, 100 parts by weight of xylene, 25 parts by weight of the above high molecular weight polymer (H-2) and 7 parts by weight of low molecular weight polypropylene (Mw = 800) , And the mixture is heated and stirred under reflux to perform preliminary dissolution. This state was maintained for 12 hours to obtain a uniform preliminary solution (Y-3) of the high molecular weight polymer, (H-2) and the low molecular weight polypropylene.

The Tg of the solid content in the pre-dissolved solution was 59 ° C.
Met.

After mixing the above pre-dissolved solution (Y-3) and 260 parts by weight of the low molecular weight polymer (L-2) solution under reflux,
The solvent was distilled off, and the obtained resin was cold-rolled, solidified and pulverized to obtain a resin composition for toner (V). The obtained resin composition (V) had a THF-insoluble content of less than 3% by weight.

When the molecular weight of the resin composition (V) was measured, it had peaks at 7,800 and 890,000, the main peak was at 7,800, and Mw / Mn was 4
6.0. The Tg of the resin composition (V) was 58 ° C.

Comparative Production Example 1 of Resin Composition Synthesis of High Molecular Weight Polymer (H-3) 180 parts by weight of degassed water and 20 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol were charged into a four-necked flask. 77 parts by weight of styrene, 23 parts by weight of n-butyl acrylate, and 1-bis (tert-butylperoxy) 3
A mixture of 0.1 part by weight of 3,5-trimethylcyclohexane (10-hour half-life temperature; 90 ° C.) was added, and stirred to form a suspension.

After sufficiently replacing the inside of the flask with nitrogen, 8
The temperature was raised to 5 ° C. to initiate polymerization. After maintaining at the same temperature for 24 hours, 0.1 part by weight of benzoyl peroxide (10-hour half-life temperature; 72 ° C.) was further added. Furthermore,
The polymerization was completed by holding for 12 hours.

The high molecular weight polymer (H-3) was separated by filtration, washed with water, dried and analyzed. Mw = 960,000, Mn
= 50,000, PMw = 600,000, Tg = 60 ° C., THF-insoluble content was 0.5%, which was substantially not contained, and the branching index g ′ was 1.04.

Preparation of Binder In a four-necked flask, 100 parts by weight of xylene, 75 parts by weight of the low-molecular-weight polymer (L-1) having a degree of branching g 'of 1.05, and high-molecular-weight polymer (H-3) 25 parts by weight and 7 parts by weight of a low-molecular-weight polyethylene (Mw = 1,500) were charged, the mixture was heated, stirred under reflux for 12 hours, mixed, and then the organic solvent was distilled off. After cold rolling, solidifying and pulverizing, a comparative resin composition (i) was obtained.

When the molecular weight of the comparative resin composition (i) was measured, it had peaks at 7,500 and 390,000, the main peak was at 7,500, and the Mw / M
n was 27.9. T of comparative resin composition (i)
g was 55 ° C.

Comparative Production Example 2 of Resin Composition Synthesis of Low-Molecular-Weight Polymer (L-5) 300 parts by weight of xylene was charged into a four-necked flask, and the inside of the vessel was sufficiently purged with nitrogen while stirring. Sealed,
The temperature was raised to xylene reflux.

A mixture of 88 parts by weight of styrene, 12 parts by weight of n-butyl acrylate, 0.01 part by weight of divinylbenzene, and 7 parts by weight of di-tert-butyl peroxide was maintained at the same temperature while maintaining the pressure and reflux conditions. Was added dropwise over 2 hours and then held for 1 hour to complete the weight, thereby obtaining a low molecular weight polymer (L-5) solution.

A part of this polymer solution was sampled,
The polymer was dried under reduced pressure, and the obtained low molecular weight polymer (L-5) was obtained.
Was analyzed, Mw = 8,600, Mn = 4,30
0, PMw = 7,200, Tg = 64 ° C., and branching index g ′ = 1.52. At this time, the conversion of the polymer was 94%.

Preparation of Binder A pre-dissolved solution (Y-
After preparing 2), 225 parts by weight of a low molecular weight polymer (L-5) solution having a degree of branching g 'of 1.52 was mixed under reflux.
Thereafter, the organic solvent was distilled off, and the obtained resin was cold-rolled, solidified and pulverized to obtain a comparative resin composition (ii).

When the molecular weight of the comparative resin composition (ii) was measured, it had peaks at molecular weights of 7,800 and 850,000, the main peak was at 7,800, and Mw / M
n was 50.6. The Tg of the comparative resin composition (ii) was 60 ° C.

Further, when the flakes of this resin composition were observed with a video microscope, reaggregates were confirmed.

Toner Production Examples 1 to 5 and Comparative Production Example
Resin composition (I) obtained in Production Examples of one or more resin compositions
To (V), and 100 parts by weight of each of the comparative resin compositions (i) and (ii) obtained in Comparative Production Examples, 100 parts by weight of the magnetic fine powder, and a negative charge control agent (azo dye-based iron Complex:
After uniformly mixing 2 parts by weight of the complex [I] -7),
This was melt-kneaded with a twin-screw extruder heated to 110 ° C. and having a ratio of the length L of the entire kneading zone to the major axis D of the shaft of 29.5. After cooling, the kneaded product was coarsely pulverized with a hammer mill and further finely pulverized with a jet mill, and the obtained pulverized product was classified by wind power to obtain a magnetic toner having a weight average diameter of 6.4 μm and a comparative magnetic toner.

For each 100 parts by weight of each of these magnetic toners, 1.2 parts by weight of silicone oil-treated hydrophobic silica fine powder (BET specific surface area: 200 m ² / g) was dry-mixed, and the hydrophobic silica fine powder was removed. The added magnetic toners (A) to (E) and the comparative magnetic toners (a) and (b) were obtained.

[0202] The resin composition (I) obtained in the toner production example 6 and the resin composition production examples in Comparative Production Example 3 and the comparative resin composition (ii) obtained in the comparative production example were used. 100 parts by weight of carbon black (BE
T specific surface area: 130 m ² / g) 5 parts by weight and a negative charge control agent (azo dye-based iron complex: the above complex [II] -1) 3 parts by weight, the length D and the axis of the whole knee zone. Major diameter D
The non-magnetic toner having a weight average diameter of 6.2 μm and a comparative non-magnetic toner were obtained in the same manner as in the above-mentioned toner production example except that the mixture was melt-kneaded with a uniaxial extruder having a ratio of 33.7.

1.5 parts by weight of hydrophobic titanium oxide fine powder (BET) was added to 100 parts by weight of each of these non-magnetic toners.
Specific surface area: 150 m ² / g) was dry-mixed to obtain a non-magnetic toner (F) to which hydrophobic titanium oxide fine powder was externally added, and a comparative specific magnetic toner (b).

The molecular weight measurement result of the obtained toner, and
Table 1 shows the measurement results of the branching index in the low molecular weight region.

The binder resin component of each of the obtained toners is T
The content of HF insolubles was less than 3% by weight.

[0206]

[Table 1]

Next, the image forming apparatus used in this embodiment will be described. In this example, a commercially available laser beam printer LBP-PX (manufactured by Canon) was used under the following conditions.

A preferred specific example of the image forming apparatus is shown in FIGS.
This will be described with reference to FIG.

In this embodiment, a reversal developing apparatus for developing a negative (negative) latent image on a photoreceptor using a negative (negative) toner will be described as an example.

FIG. 1 is a schematic explanatory view of a cross section of a laser beam printer.

OPC photosensitive drum 10 (diameter 24 mm)
Rotates in the direction of the arrow, and is uniformly charged by the charging roll 11 so that the dark portion potential (Vd) becomes −600 V. Next, the image portion is exposed by the exposure device 14,
An electrostatic latent image having a bright portion potential (V1) of -150 V is formed. A gap (300 μm) is set without contact between the photosensitive drum 10 and the developer layer on the developer carrier 16 (including the magnet 17), and an AC bias (f = 1800 Hz, Vpp = 120)
0 V) and a DC bias (Vdc = −400 V) were applied to the developer carrier 16 by the bias applying means V, and the image portion was developed with negative toner to form a toner image on the photosensitive drum. The obtained toner image is transferred onto a transfer material by a transfer roll 19, and the toner remaining on the photoreceptor surface is cleaned by a cleaner 13. On the other hand, the transfer material P separated from the photosensitive drum 10 is heated and fixed by the heat fixing device H in order to fix the toner image on the transfer material P. Image formation is performed by repeating the above steps. At this time, the surface temperature of the temperature measuring element 21d of the heating body 21 of the heating and fixing apparatus H is 130 ° C., the total pressure between the heating body 21 and the pressure roller 23 is 6 kg, and the nip between the pressure roller and the film is 3 mm. Film 22
A heat-resistant polyimide film having a thickness of 50 μm and having a low-resistance release layer in which a conductive material is dispersed in PTEF on a contact surface with a transfer material was used.

When using a non-magnetic toner, an image is formed by attaching a sponge-made developer application roller to the back surface of the developer carrier 16 in the developer storage container 15.

Under the above set conditions, room temperature and normal humidity (25 ° C., 6
0% Rh) and a high-temperature, high-humidity (30 ° C., 80% Rh) environment at a printout speed of 4 sheets (A4 size) / min while continuously supplying the toner of the present invention and the comparative toner. A printout test was performed on 10,000 sheets, and the obtained images were evaluated for the following items.

At the same time, the matching between the used image forming apparatus and the toner was also evaluated.

Further, the temperature of the heater 21 was changed by 5 ° C. at a time, and the fixing temperature range of each toner (the temperature from the fixing start temperature to the temperature at which no high-temperature offset occurs) was measured.

Evaluation of Printout Image (1) Image Density Evaluation was performed by maintaining the image density at the end of 3,000 printouts on ordinary paper for copying machines (75 g / m ² ).
The image density was measured by using a "Macbeth reflection densitometer" (manufactured by Macbeth Co., Ltd.) with respect to a printout image of a white background portion having a document density of 0.00.

◎ (excellent): 1.40 or more, （(good):
1.35 or more and less than 1.40 △ (acceptable): 1.00 or more and less than 1.35 × (impossible): less than 1.00

(2) Dot Reproducibility The pattern shown in FIG. 4 was printed out, and the dot reproducibility was evaluated.

◎: Very good (2 defects or less / 100) ○: Good (3 to 5 defects / 100) △: Practical (6 to 10/100 defects) ×: Unpractical (Decrease) 11 or more / 100)

(3) Image fog The fog density (%) was calculated from the difference between the whiteness of the white background portion of the printout image measured by the “Reflectometer” (manufactured by Tokyo Denshoku Co., Ltd.) and the whiteness of the transfer paper. Image fog was evaluated.

◎: very good (less than 1.5%) ：: good (1.5% or more, less than 2.5%) △: practical (2.5% or more, less than 4.0%) ×: Not practical (more than 4%)

(4) Fixing Property The fixing property was evaluated by applying a load of 50 g / cm ² , rubbing the fixed image with soft thin paper, and decreasing the image density before and after rubbing (%).

◎ (excellent): 5% or less, （(good):
5% or less, less than 10% △ (acceptable): 10% or more, less than 20%, × (impossible): 2
0% or more

(5) Offset Resistance The offset resistance was evaluated by printing out a sample image having an image area ratio of about 5% and evaluating the degree of stain on the image after 3000 sheets.

◎: very good (not generated), ：: good (almost no occurrence) Δ: practical, ×: impractical

Evaluation of Matching of Image Forming Apparatus (1) Matching with Developing Sleeve After completion of the printout test, the state of fixation of residual toner on the surface of the developing sleeve and the effect on the printout image were visually evaluated.

◎: Very good (not generated) ：: Good (almost no occurrence) Δ: Practical (there is sticking, but there is little effect on the image) ×: Practical not possible (a lot of sticking, image unevenness Arises)

(2) Matching with Photosensitive Drum The occurrence of scratches on the surface of the photosensitive drum and sticking of residual toner and the effect on printout images were visually evaluated.

◎: very good (not generated) 良好: good (slight flaws are observed, but there is no effect on the image) Δ: practical (there is sticking or flaws, but the effect on the image is low) X): Impossible (many sticks, causing vertical streak-like image defects)

(3) Matching with Fixing Apparatus The appearance of the fixing film surface was observed and its durability was evaluated.

(1) Surface Properties The surface of the fixing film surface after the printout test was visually evaluated for occurrence of scratches and scraping.

◎: very good (not generated), ：: good (almost no occurrence) Δ: practical, ×: impractical

(2) Fixing State of Residual Toner The fixing state of the residual toner on the surface of the fixing film after completion of the printout test was visually evaluated.

◎: very good (not generated), ：: good (almost no occurrence) Δ: practical, ×: impractical

The above evaluation results are shown in Tables 2 and 3.

[0236]

[Table 2]

[0237]

[Table 3]

[0238]

As described above, the present invention controls the structure of the low molecular weight polymer component constituting the resin composition in the toner and specifies the physical properties of the toner, so that an extremely wide fixing temperature range can be obtained. , And has excellent dot reproducibility, and can form a stable and good image without fog for a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an image forming apparatus used in an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main part of the fixing device used in the embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a main part showing a film state when the fixing device used in the embodiment of the present invention is not driven.

FIG. 4 is an explanatory diagram of a checker pattern for checking development characteristics of toner.

FIG. 5 is a schematic explanatory view for explaining a specific example of the process cartridge of the present invention.

FIG. 6 is a schematic explanatory view for explaining a specific example of an image forming apparatus for performing the image forming method of the present invention.

FIG. 7 is a graph for explaining a method of calculating a branch index g ′.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 electrostatic latent image carrier (photosensitive drum) 11 charger (charging roll) 12 cartridge 13 cleaning unit 14 exposure unit 15 developer storage container 16 developer carrier (developing sleeve) 17 magnetic field generating unit 18 elastic layer thickness regulating member DESCRIPTION OF SYMBOLS 19 Transfer means (transfer roll) 20 Stay 21 Heating body 21a Heater substrate 21b Heating body 21c Surface protection layer 21d Temperature measuring element 22 Fixing film 23 Pressure roller 24 Coil spring 25 Film end regulating flange 26 Power supply connector 27 Disconnecting member 28 Inlet Guide 29 Exit guide (separation guide)

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI G03G 15/02 101 G03G 9/08 361 15/20 101 365 381 384 (72) Inventor Shunji Suzuki 3-30 Shimomaruko, Ota-ku, Tokyo No.2 Canon Inc. (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/08

Claims (47)

(57) [Claims] 1. An electrostatic image developing toner having a composition in which at least a binder resin component and a colorant are dispersed, wherein the binder resin component has a molecular weight of 50,000 or less and a branch index g ′ of 1 A toner for developing an electrostatic image, comprising a low-molecular-weight polymer component having a molecular weight of less than 1. 2. A binder resin component, tetrahydrofuran (T
HF) In the molecular weight distribution of gel permeation chromatography (GPC) measured by a soluble component, a low molecular weight polymer component forming a main peak in a molecular weight region of 2000 to 30,000 and a subpeak in a region exceeding a molecular weight of 50,000. 2. The electrostatic image developing toner according to claim 1, further comprising a shoulder-forming high molecular weight polymer component. 3. The electrostatic image developing toner according to claim 1, wherein the branch index g ′ of the low molecular weight polymer component is 0.97 or less. 4. The electrostatic image developing toner according to claim 3, wherein the branch index g ′ of the low molecular weight polymer component is 0.95 or less. 5. The toner for developing an electrostatic image according to claim 4, wherein the branch index g ′ of the low molecular weight polymer component is 0.93 or less. 6. The THF-soluble component of the binder resin component has a subpeak in a region having a molecular weight of 200,000 or more.
The toner for developing electrostatic images according to any one of the above. 7. The toner for developing an electrostatic image according to claim 6, wherein the THF-soluble component of the binder resin component has a subpeak in a region having a molecular weight of 300,000 or more. 8. The THF-soluble component of the binder resin component has a ratio Mw / weight average molecular weight (Mw) to number average molecular weight (Mn).
The electrostatic image developing toner according to any one of claims 1 to 7, wherein the value of Mn is larger than 30. 9. The THF-soluble component of the binder resin component is Mw /
9. The electrostatic image developing toner according to claim 8, wherein the value of Mn is 35 or more. 10. The binder resin component has a glass transition point (T
The toner according to claim 1, wherein g) is 50 to 70 ° C. 10. 11. The toner for developing an electrostatic image according to claim 1, wherein the composition contains a low molecular weight wax. 12. The low molecular weight wax is a compound selected from the group consisting of polypropylene, polyethylene, microcrystalline wax, carnauba wax, sasol wax, paraffin wax, and oxides and graft modified products thereof. 3. The toner for developing an electrostatic image according to item 1. 13. The electrostatic image developing toner according to claim 11, wherein the low molecular weight wax has a weight average molecular weight (Mw) of 30,000 or less. 14. The electrostatic image developing toner according to claim 13, wherein the low molecular weight wax has a Mw of 10,000 or less. 15. The low molecular weight wax is a binder resin component 1.
15. The electrostatic image developing toner according to claim 11, wherein the toner is contained in an amount of 1 to 20 parts by weight with respect to 00 parts by weight. 16. The low molecular weight wax is represented by the following formula: RY [R represents a hydrocarbon group having a weight average molecular weight of not more than 3000 by gel permeation chromatography, Y represents a hydroxyl group, a carboxyl group, an alkyl ether group, an ester group. Or a sulfonyl group. The toner for developing an electrostatic image according to any one of claims 11 to 15, comprising at least 60% by weight of a compound having the following formula: 17. A low molecular weight wax comprising the compound
17. The toner for developing an electrostatic image according to claim 16, wherein the toner is contained in an amount of at least% by weight. 18. The compound, wherein Mn is from 200 to 2,000.
18. The electrostatic image developing toner according to claim 16, wherein Mw is 400 to 3000, and Mw / Mn value is 3.0 or less. 19. A composition comprising a magnetic material and a binder resin component 10.
19. The electrostatic image developing toner according to claim 1, wherein the toner is contained in an amount of 40 to 150 parts by weight based on 0 part by weight. 20. The electrostatic image according to claim 1, wherein the composition contains 0.1 to 20 parts by weight of a nonmagnetic colorant based on 100 parts by weight of the binder resin component. Development toner. 21. The electrostatic image developing toner according to claim 1, wherein the composition contains a charge control agent. 22. The charge control agent is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the binder resin component.
2. The electrostatic image developing toner according to item 1. 23. The charge control agent according to claim 21, wherein the charge control agent is a compound selected from the group consisting of a metal complex of salicylic acid, a metal complex of naphthoic acid, a metal complex of dicarboxylic acid, and a metal complex of a derivative thereof. The toner for developing an electrostatic image according to the above. 24. The electrostatic image developing toner according to claim 1, wherein the low molecular weight polymer component is a styrene copolymer, a styrene-acrylate copolymer or a styrene-methacrylate copolymer. 25. A charging step of bringing a charging member into contact with a member to be charged, applying a voltage to the charging member from outside, and charging the member to be charged, and forming an electrostatic image on the charged member to be charged. And a developing step of developing the electrostatic charge image with toner to form a toner image on the member to be charged; and
A transfer step of transferring the toner image onto the transfer material without interposition, and a fixing step of heating and fixing the toner image on the transfer material, wherein the toner has at least a composition having a binder resin component and a colorant dispersed therein. An image forming method, which is a toner for developing a charge image, wherein the binder resin component contains a low molecular weight polymer component having a molecular weight of 50,000 or less and a branch index g ′ of less than 1. 26. A molecular weight of GPC measured by a THF-soluble component of the binder resin component, wherein the molecular weight is 2,000.
A low molecular weight polymer component forming a main peak in a region of ~ 30,000 and a sub peak in a region exceeding a molecular weight of 50,000, or
The image forming method according to claim 25, further comprising a shoulder-forming high molecular weight polymer component. 27. The heating and fixing step, wherein a visible image of the developer is formed by a fixedly supported heating member and a pressing member which is in pressure contact with the heating member and is in close contact with the heating member via a film. 25. A fixing step of heating and fixing the recording material, wherein the toner is the toner according to claim 3.
27. The image forming method according to 5 or 26. 28. A process cartridge comprising at least a developing unit and a photoconductor, wherein the developing unit and the photoconductor are integrally formed as a cartridge, and the process cartridge is detachable from an image forming apparatus main body. The developing means has a toner, and the toner is an electrostatic image developing toner having at least a composition in which a binder resin and a colorant are dispersed, and the binder resin component has a molecular weight of A low molecular weight polymer component having a molecular weight of 50,000 or less and a branch index g ′ of less than 1. 29. The process cartridge according to claim 28, wherein the process cartridge further has a charging unit for charging the photosensitive member. 30. The process cartridge according to claim 29, wherein the charging unit is a contact charging unit in contact with the photosensitive member. 31. The process cartridge according to claim 30, wherein the contact charging means is a charging roller. 32. The process cartridge according to claim 30, wherein the contact charging means is a charging brush. 33. The process cartridge according to claim 28, wherein the toner is the toner according to any one of claims 2 to 24. 34. A low molecular weight polymer component containing a mixture of a low molecular weight polymer component and a high molecular weight polymer component and having a molecular weight of 50,000 or less has a branching index g ′ of less than 1. Resin composition for toner. 35. The mixture has a molecular weight of 200 as determined by its molecular weight distribution in GPC as determined by its THF-soluble matter.
35. The method according to claim 34, comprising a low molecular weight polymer component forming a main peak in a region of 0 to 30,000 and a high molecular weight polymer component forming a subpeak or a shoulder in a region exceeding a molecular weight of 50,000. Resin composition for toner. 36. The low molecular weight polymer component is used as a polymerization initiator in the presence of a prepolymer and a second monomer as follows: The resin composition for a toner according to claim 34 or 35, wherein the polymer is a polymer obtained by adding a peroxide having a functional group of the following. 37. The resin composition for a toner according to claim 34, wherein the high molecular weight polymer in the high molecular weight region is a polymer polymerized in the presence of a polyfunctional polymerization initiator. 38. The mixture is prepared by dissolving or dispersing a high molecular weight polymer, a low molecular weight polymer forming a main peak and a low molecular weight wax in an organic solvent, and then removing the organic solvent. Claims 34 to 3
8. The resin composition for a toner according to any one of items 7 to 7. 39. The mixture is obtained by previously dissolving or dispersing a high molecular weight polymer and a low molecular weight wax in an organic solvent.
39. The resin composition for a toner according to claim 34, which is prepared by mixing with a solution of a low molecular weight polymer having a main peak in an organic solvent and removing the organic solvent. 40. The resin composition for a toner according to claim 34, wherein the branch index g ′ of the low molecular weight polymer component is 0.97 or less. 41. The resin composition for a toner according to claim 40, wherein the branch index g ′ of the low molecular weight polymer component is 0.95 or less. 42. The resin composition for a toner according to claim 41, wherein the branch index g ′ of the low molecular weight polymer component is 0.93 or less. 43. A method for producing a resin composition for a toner having a mixture of a low molecular weight polymer component and a high molecular weight polymer, wherein the low molecular weight polymer component having a molecular weight of 50,000 or less and a branch index g ′ of less than 1 is used. And the following as a polymerization initiator: A method for producing a resin composition for a toner, comprising polymerizing and preparing a monomer in the presence of a peroxide having the following functional group. 44. A low-molecular-weight polymer component and a high-molecular-weight polymer component are mixed, and a THF-soluble component of the mixture has a main peak in a molecular weight distribution region of 2000 to 30,000 in a molecular weight distribution of GPC, The method for producing a resin composition for a toner according to claim 43, wherein the resin composition is prepared so as to have a subpeak or a shoulder in a region exceeding 50,000. 45. The resin composition for a toner according to claim 43, wherein the high molecular weight polymer forming the high molecular weight region is prepared by polymerizing a monomer in the presence of a polyfunctional polymerization initiator. Manufacturing method. 46. The mixture is obtained by dissolving or dispersing a high molecular weight polymer forming a high molecular weight region, a low molecular weight polymer having a main peak and a low molecular weight wax in an organic solvent, and then removing the organic solvent. Claim 4 which is prepared
47. The method for producing a resin composition for a toner according to any one of items 3 to 45. 47. A mixture in which a high molecular weight polymer forming a high molecular weight region and a low molecular weight wax are previously dissolved or dispersed in an organic solvent, and then mixed with an organic solvent solution of a low molecular weight polymer having a main peak. The method for producing a resin composition for a toner according to any one of claims 43 to 46, wherein the method is prepared by removing an organic solvent.