JPH08211652A - Image forming method - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an image forming method in which the adhesion of toner to an electrostatic latent image carrier is reduced. According to the present invention, a step of applying a voltage having at least an AC component to a charging member and bringing the charging member into contact with a latent image carrier to charge the surface of the latent image carrier, an electrostatic latent image. In the image forming method, which comprises a step of forming an electrostatic latent image with a toner, the charging member comprises an upper layer portion made of a high-resistive material in contact with a member to be charged and a lower layer of the upper layer portion. And a conductive lower layer portion to which a voltage having at least an AC component is applied, and the hardness of the charging member is AS.
KER-C is 60 ° or less, the toner is formed of a composition containing at least a polymer component and a charge control agent, and the polymer component of the composition has an acid value of 1 mgKOH / g or more. The present invention relates to an image forming method.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an image forming method for developing a dielectric latent image in a method such as electrophotography or electrostatic printing.

[0002]

2. Description of the Related Art US Pat.
A number of methods are known as described in Japanese Patent No. 7,691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc., but generally, a method using a photoconductive substance is used. The surface of the latent electrostatic image bearing member is uniformly charged by various means, and then an electrostatic latent image is formed by irradiating a part of the surface with an electrostatic latent image. Then, the latent image is developed with toner, and necessary. After transferring the toner image to a transfer material such as paper according to
The toner is fixed by pressurization, heat pressurization, solvent vapor or the like to obtain a copy, and the toner left untransferred on the photoconductor is cleaned if necessary, and the above steps are repeated.

As a charging method, recently, many contact charging methods have been proposed in which a charging member is brought into contact with the surface of an electrostatic latent image bearing member to apply a voltage in which a DC voltage and an AC voltage are superposed to perform charging. Lower applied voltages may be used as compared to the corona charging method of In addition, there is an advantage that the generation of ozone is small. According to this contact charging method, as shown in FIG. 1, for example, the charging roller 2 as a charging member is contact driven and rotated on the electrophotographic photosensitive drum 1 to generate an AC voltage V.
_The photosensitive drum 1 can be uniformly charged by applying a voltage (V _ac + V _dc ) obtained by superimposing _ac and the DC voltage V _dc to the charging roller 2.

As can be understood from the above, the charging roller 2 is required to maintain conductivity, and the charging roller 2 is conventionally surrounded by E around the core metal.
A conductive elastic member in which carbon is dispersed in elastic rubber such as PDM or NBR is used. Therefore, the charging roller 2 has a rubber hardness of ASKER.
At -C, it was inevitably over 70 °. When contact charging is performed using the charging roller 2 as described above, the conductive member 2b vibrates due to the AC component V _ac of the voltage applied to the cored bar 2a, and the charging roller 2 and the photosensitive drum 1
There is a problem that sound is generated at the nip portion (contact portion) between and. The generation of this noise tended to increase as the hardness increased.

Further, if the AC component V _ac of the applied voltage is eliminated, no sound is generated, but uniform charging of the surface of the photosensitive drum 1 cannot be obtained, and spot-like uneven charging occurs.

Therefore, the applicant of the present invention has filed Japanese Patent Application Laid-Open No. 1-19116.
The hardness of the charging member is ASKER (Asker)
We proposed a charging method that reduces the noise level due to charging by setting the temperature at −C to 60 ° C. or lower.

However, recently, there is a strong technical demand for low energy or high speed for copying machines, printers and the like using the electrophotographic method. As a result, the toner is softened at low energy. Must be designed. When such a toner is combined with the above-mentioned charging member whose hardness is lowered, the toner is apt to adhere to the surface of the electrostatic latent image carrier in a film form (so-called filming phenomenon), and The drawback is that the life is shortened. This tendency is particularly strong when the charging member is in the form of a roller, because when the hardness of the charging member decreases, when the driving force of the electrostatic latent image carrier is transmitted to the charging member via the contact surface, It is presumed that the deformation causes the force to disperse, causing slippage on the surfaces of the charging member and the electrostatic latent image carrier.

Generally, in order to soften the toner with low energy, it is effective to lower the glass transition point (Tg) and molecular weight of the binder resin, but on the other hand, the surface of the electrostatic latent image bearing member is filled with the toner. It is extremely disadvantageous to the toner, and there is a limit to the blocking resistance of the toner.

Japanese Unexamined Patent Publication No. 2-168264 and 2-2
No. 35069, No. 5-173363, No. 5-
In 173366 and 5-24371,
A binder composition for a toner and a toner having improved fixing property, blocking resistance property, image property, etc. by controlling the molecular weight, mixing ratio, oxidation and its ratio of the low molecular weight component and the high molecular weight component in the binder resin have been proposed. However, the degree of perfection is still low.

Particularly, in the adjustment of the acid value described in the above-mentioned publication, the coloring agent such as magnetic iron oxide, the charge control agent, and other additives are poorly dispersed, and the surface of the developer carrying member such as a carrier or a sleeve is contaminated. Image deterioration such as fog and density decrease occurs.

Further, further low temperature fixing is insufficient.

Further, in Japanese Patent Laid-Open No. 62-9256,
It discloses a binder composition for toner in which two kinds of vinyl resins having different molecular weights and resin acid values are blended. However, when such a binder resin is used,
To improve the compatibility and dispersibility of the toner constituent components, the kneading conditions must be strengthened, and the resin of the binder is affected by the cleavage of molecules and exhibits desired performance such as offset resistance. Will be difficult to do. Also, if kneading is carried out to such an extent that molecular cutting does not occur, dispersion of other additives will immediately occur, promoting contamination of the carrier of the carrier such as carrier and sleeve to the surface of the developer carrier, and fogging and scattering of the developing property. Will cause serious problems. In particular, when a polymer having a weight average molecular weight of 1,000,000 or more is used, these phenomena become apparent.

By the way, Japanese Patent Laid-Open No. 3-72505 discloses a vinyl-based toner binder having a molecular weight of 300,000 or more using a polyfunctional initiator. When such a resin is used, the fixability is to some extent. Although satisfactory, in addition to the above-mentioned problems, the performance of the developer deteriorates when left at high temperature. The cause of this phenomenon is not clear, but in our study, only the molecular breakage of the binder resin was promoted during toner formation, so that the proportion of the resin component having a sufficient molecular weight in the toner composition was It is supposed to be low and weak against thermal shock.

Regarding the filming of the toner on the surface of the electrostatic latent image bearing member, various external additives have been proposed for the purpose of polishing the surface of the electrostatic latent image bearing member. Since the polishing effect is too strong for the body surface, it causes various adverse effects.

On the other hand, the mainstream of the electrostatic latent image bearing member is OPC whose surface is coated with a resin, and there are many proposals for the surface layer, but in order to fix the toner with low energy and reproduce a high-definition image. Under the present circumstances, it is very difficult to obtain a satisfactory performance with respect to the technical trend of toner particle size reduction and contact charging.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to apply a voltage having an AC component to a charging member, to uniformly charge the surface of an electrostatic latent image bearing member with a low applied voltage, and to generate less ozone. Even when a toner that uses a contact charging method and does not generate noise due to charging and realizes low temperature fixing and high speed is used, the toner film is fixed to the surface of the electrostatic latent image carrier (so-called filming). It is an object of the present invention to provide an image forming method capable of achieving a long life without causing a phenomenon).

[0017]

According to the present invention, a voltage having at least an AC component is applied to a charging member,
In the image forming method, the method comprises the steps of bringing the charging member into contact with the latent image carrier to charge the surface of the latent image carrier, forming an electrostatic latent image, and developing the electrostatic latent image with toner. The charging member includes an upper layer portion made of a high resistance material that is in contact with an object to be charged, and a conductive lower layer portion that constitutes a lower layer of the upper layer portion and to which a voltage having at least an AC component is applied. The hardness of the charging member is 60 ° or less in ASKER-C, the toner is formed of a composition containing at least a polymer component and a charge control agent, and the polymer component of the composition is 1 mgKOH / g or more. The present invention relates to an image forming method having an acid value of.

The hardness of the charging member is 60 ° in ASKER-C.
By the following, it is possible to obtain a contact width sufficient for charging with a weak pressing force on the surface of the electrostatic latent image bearing member, which is the member to be charged, and to make the surface of the electrostatic latent image bearing member uniform with a low applied voltage. It becomes possible to charge, less ozone is generated, and noise is not generated by charging even when a voltage having an AC component is applied to the charging member. Further, by using the polymer component of the toner composition as described above, low temperature fixing and high speed are realized, and the toner film is fixed on the surface of the electrostatic latent image carrier (so-called filming phenomenon). Is less likely to occur, the life of the electrostatic latent image carrier can be extended.

The reason why the above effects are obtained is that the polymer component of the toner composition has the above-mentioned constitution.
Even though the low temperature fixing property is improved, it is strong against mechanical load in the low temperature range and the property that it is hard to stick is obtained, so in the contact charging method where the charging member and the electrostatic latent image carrier are always in contact with each other. However, toner is unlikely to adhere to the surface of the electrostatic latent image carrier. Also, the hardness of the charging member can be set to ASKER
By setting −C to 60 ° or less, it is possible to obtain a contact width sufficient for charging with a weak pressing force on the surface of the electrostatic latent image bearing member, which is the member to be charged. It is difficult for toner to stick to the surface.

The hardness of the charging member is 60 degrees in ASKER-C.
When the AC voltage is exceeded, noise due to charging is large, and in order to obtain a sufficient contact width for charging, the surface of the electrostatic latent image carrier must be brought into contact with a strong pressing force. The film-like adhesion of toner (so-called filming phenomenon) or the like is likely to occur on the surface of the electrostatic latent image carrier, which is not preferable.

The hardness of the charging member according to the present invention is ASKER-C.
As a form for setting the angle to 60 ° or less, preferably,
It is desirable that the lower layer portion be composed of an elastic layer made of thermoplastic elastomer or soft rubber and a conductive layer, or that the lower layer portion be formed of a conductive sponge.

Further, the upper layer portion of the charging member, which is in contact with the surface of the electrostatic latent image carrier, is made of a high resistance material and has a thickness of 50 to 200 μm.
It is preferable that the layer has a thickness of about m in order to obtain stable chargeability without causing leakage.

The polymer component of the toner composition of the present invention is 1
Characterized by having an acid value of mgKOH / g or more,
It is more preferably 2 mgKOH / g or more.

By introducing an acid component into the polymer component of the toner composition as described above, the ASKER-C of the present invention can be obtained.
Even when a charging member having a hardness of 60 ° or less is used, toner is less likely to adhere to the surface of the electrostatic latent image carrier.

Further, the polymer component of the toner composition of the present invention preferably contains substantially no THF-insoluble matter.
Specifically, it is more preferably 5% by weight or less, preferably 3% by weight or less, based on the resin composition.

The THF-insoluble matter in the present invention means the weight ratio of the polymer component (substantially cross-linked polymer) which becomes insoluble in the THF solvent in the resin composition in the 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 as a value measured as follows.

That is, 0.5 to 1.0 g of a toner sample is weighed (w ₁ g), and a cylindrical filter paper (for example, No.
86R), put on a Soxhlet extractor, and extracted with 100 to 200 ml of THF as a solvent for 6 hours. After evaporating the soluble component extracted by the solvent,
Vacuum-dry at 100 ° C. for several hours, and weigh the amount of the THF-soluble resin component (w ₂ g). The weight of the components other than the resin component such as the magnetic substance or pigment in the toner is (w ₃ g). T
The HF insoluble content is obtained from the following formula.

THF insoluble matter (%) = [{(w ₁ − (w ₃
+ W ₂ )} / (w ₁ -w ₃ )] × 100

If the content of THF insolubles exceeds 5% by weight, the fixability is deteriorated.

T of the polymer component in the toner composition of the present invention
The GPC chromatogram measured by the HF-soluble matter has a molecular weight of 3 × 10 ^{3 to} 3 × 10 ⁴ (more preferably 5 ×).
Having a main peak in the region of 10 ^{3 to} 2 × 10 ⁴ and having a molecular weight of 1 × 10 ^{5 to} 3 × 10 ⁶ (more preferably,
It is preferable to have a subpeak or a shoulder in the region of 5 × 10 ⁵ to 1 × 10 ⁶ ).

The area ratio of the polymer component having a molecular weight of 1,000,000 or more in the GPC chromatogram is 3%.
It is preferable that these exist. More preferably 3 to 1
It is 0%. The presence of 3% or more of a THF-soluble component having a molecular weight of 1,000,000 or more improves offset resistance without impairing low-temperature fixing, and at the same time improves the storage stability of the developer when it is left at high temperature. Can be increased.

In the present invention, the molecular weight distribution of the polymer component of the toner composition is measured by GPC (gel permeation chromatography) under the following conditions.

<GPC measurement conditions for toner composition and resin> Apparatus: GPC-150C (manufactured by Waters) Column: KF801-7 (manufactured by Showdex) 7 consecutive temperatures: 40 ° C Solvent: THF (tetrahydrofuran) 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

The polymer component according to the present invention is a low molecular weight polymer (having a molecular weight of 5 × in GPC chromatogram).
10 ⁴ less than the area) the acid value of the (A _VL), the relationship of the high molecular weight polymer (molecular weight in the GPC chromatogram 5 × 10 ⁴ or more regions) the acid value of (A _VH) are at the A _VL> A _VH It is preferable that the acid value (A _VL ) of the low molecular weight polymer (region of molecular weight less than 5 × 10 ⁴ in the GPC chromatogram) is 21 to 35 mgKOH / g, and the high molecular weight polymer (GPC chromatogram). The acid value (A _VH ) in the gram of a molecular weight of 5 × 10 ⁴ or more) is 0.5 to 11 mgKOH / g, and the difference is 10 ≦ (A _VL −A _VH ) ≦ 27.

As a result of earnest studies, the present inventors have found that in a toner resin composition comprising a low molecular weight polymer and a high molecular weight polymer, it is necessary that each polymer component has the acid value shown above at low temperature fixability, It has been found that it is most effective in anti-offset property, prevention of toner adhesion to the latent image carrier, and further improvement of developability.

The low temperature fixability is governed by the Tg and the molecular weight distribution of the low molecular weight component, but the acid component is contained in this component, and the acid value of the high molecular weight polymer is 10 mgKO.
It has been found that by increasing H / g or more, the viscosity can be made lower than that of the resin composition having the same Tg and the same molecular weight distribution as the acid value outside the above range.

This is because by setting the acid value of the high molecular weight component lower than the acid value of the low molecular weight component by 10 mgKOH / g or more (acid value 0.5 to 11 mgKOH / g), the molecules of the low molecular weight component and the high molecular weight component are It is considered that the chain entanglement is suppressed to some extent, and therefore, the viscosity is reduced on the low temperature side and the elasticity is maintained on the high temperature side. This also leads to low-temperature fixing in a high-speed machine and improvement in developing characteristics.

On the other hand, when the difference in the acid value exceeds 27, the mixing property of the low molecular weight component and the high molecular weight component becomes defective, and the durability offset property and the developability are deteriorated.

Furthermore, the acid value of the low molecular weight component is 21 mgK.
It was clarified that the charge rising property becomes good at OH / g or more.

On the other hand, the acid value of the low molecular weight component is 35 mgKO
If it exceeds H / g, environmental characteristics, particularly developability under high humidity, are impaired.

When the acid value of the high molecular weight component is less than 0.5, the low molecular weight component (acid value 21 to 35 mgKOH /
Mixability with g) becomes a problem, and developability, particularly fog characteristics, deteriorates.

Further, the polymer component of the toner resin composition of the present invention, in the relation between the low molecular weight component and the high molecular weight component, has a mixing ratio of W _L : _WH = 50: 50 to 90:10. It is necessary to. The reason is that if the ratio of the low molecular weight component to the high molecular weight component is out of this range, the fixability and the offset resistance will be impaired. That is, if the content of the low molecular weight component is less than 50% by weight, the fixability is deteriorated, whereas if the content of the high molecular weight component is less than 10% by weight, the high temperature offset resistance is deteriorated.

Further, regarding the relationship between the mixed amount of these and the acid value,

[0044]

[Outside 2] It is necessary to satisfy. The reason is that when the mixing amount of the low molecular weight component and the high molecular weight component and the respective acid values do not satisfy the relationship of the above formula, that is,

[0045]

[Outside 3] When the acid value of the low molecular weight component in the whole resin is less than 4 times the acid value of the high molecular weight resin in general, the miscibility of the low molecular weight component and the high molecular weight component increases, resulting in low viscosity at low temperature,
This is because the high elasticity on the high temperature side cannot be emphasized more.

In addition,

[0047]

[Outside 4] When it is less than 11, the rising characteristics of charging are deteriorated, while when it exceeds 30, the developability under high humidity is deteriorated.

In the present invention, the low molecular weight of the polymer component, the acid value (JIS acid value) of the polymer component and the high molecular weight polymer component are determined by the following method.

<Preparation of each component> [Device configuration] LC-908 (manufactured by Nippon Analytical Industry Co., Ltd.) JRS-86 (the same company; repeat injector) JAR-2 (the same company; autosampler) FC-201 (Gilson Company; Hula cushion collector) [Column configuration] JAIGEL-1H to 5H (20φ × 600 mm: preparative column) [Measurement conditions] Temperature: 40 ° C. Solvent: THF Flow rate: 5 ml / min. Detector: RI Sample is prepared by separating additives other than the polymer component. As a preparative method, the elution time at which the molecular weight becomes 5 × 10 ⁴ is preliminarily measured, and the low-molecular polymer component and the high-molecular polymer component are fractionated before and after that. The solvent is removed from the collected sample to obtain a sample for acid value measurement.

<Measurement of Acid Value (JIS Acid Value)> 1) 0.1 to 0.2 g of a pulverized product of a sample is precisely weighed, and its weight is W (g). 2) Put the sample in a 20 cc Erlenmeyer flask, and add 10 cc of a mixed solution of toluene / ethanol (2: 1) to dissolve it. 3) Add a few drops of an alcohol solution of phenolphthalein as an indicator. 4) Titrate the solution in the flask with a burette using an alcohol solution of 0.1N KOH.

At this time, the amount of KOH solution used is S (ml)
And At the same time, a blank test is performed, and the amount of the KOH solution at this time is B (ml). 5) Calculate the acid value by the following formula.

[0052]

[Outside 5] The total acid value in the present invention is measured as follows.

<Measurement of Total Acid Value> 1) The sample is used after removing additives other than the preliminarily polymer component. About 2g of crushed sample is precisely weighed and its weight is w '
(G). 2) Put a sample in a 200 cc Erlenmeyer flask, add 1,4-dioxane (30 cc), pyridine (10 cc) and 4-dimethylaminopyridine (20 mg) and dissolve for 1 hour. 3) Add 3.5 cc of ion-exchanged water and reflux for 4 hours. Then cool. 4) Add a few drops of alcohol solution of phenolphthalein as an indicator. 5) Titrate the solution in the flask with a burette using 0.1N KOH THF solution. KO at this time
Let the amount of H solution be S '(ml). At the same time, a blank test is performed, and the amount of KOH solution at this time is defined as B '(ml). 6) The total acid value is measured by the following formula.

[0054]

[Outside 6]

As a KOH THF solution, KOH6.
6 g of ion-exchanged water (20 cc) was added and dissolved, and then THF was added.
720 CC and 100 cc of ion-exchanged water are added, and then methanol is added with stirring until it becomes transparent.

Examples of the monomer for adjusting the acid value of the polymer component include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid and its α-
Alternatively, there are β-alkyl derivatives, unsaturated dicarboxylic acids such as fumaric acid, maleic acid, and citraconic acid, and their monoester derivatives or maleic anhydride.These monomers may be used alone or as a mixture, and may be mixed with other monomers. A desired polymer can be produced by polymerizing. Among these, it is particularly preferable to use a monoester derivative of unsaturated dicarboxylic acid.

More specifically, for example, 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-butenyl succinate, monomethyl n-octenyl succinate, Monoesters of alkenyldicarboxylic acids such as monoethyl n-butenylmalonate, monomethyl n-dodecenyl glutarate, monobutyl n-butenyl adipate; phthalic acid monomethyl ester, phthalic acid monoethyl ester, phthalic acid monobutyl ester, etc. Aromatic dicarboxylic acid monoesters such as:

The carboxy group-containing monomer as described above may be added in an amount of 1 to 20% by weight, preferably 3 to 15% by weight, based on all monomers constituting the polymer side of the binder resin.

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

In the present invention, the carboxylic acid group and the carboxylic acid ester moiety in the copolymer obtained by the above method may be alkali-treated to be saponified. That is, it is preferable to react with an alkali cation component to change the carboxylic acid group or the carboxylic acid ester moiety into a polar functional group. 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 crosslinking reaction will decrease if the carboxyl group is in an anhydrous state, that is, in a ring-closed state.

This alkali treatment may be carried out, after the binder resin is produced, by adding it as an aqueous solution into the solvent used during the polymerization and stirring. Examples of the alkali that can be used in the present invention include hydroxides of alkali metals and alkaline earth metals such as Na, K, Ca, Li, Mg and Ba; Z
There are hydroxides of transition metals such as n, Ag, Pb, and Ni; hydroxides of quaternary ammonium salts such as ammonium salts, alkylammonium salts, and pyridinium salts, and particularly preferable examples thereof include NaOH and KOH. .

In the present invention, the saponification reaction does not have to be carried out over all of the carboxylic acid groups and carboxylic acid ester moieties in the copolymer, and the saponification reaction partially proceeds to give polar functional groups. It should be different.

The amount of alkali used in the saponification reaction is difficult to determine depending on the type of polar group in the binder resin, the dispersion method, the types of constituent monomers, etc. It may be from 02 to 5 times equivalent. When the amount is less than 0.02 times the equivalent, the saponification reaction is not sufficient and the number of polar functional groups generated by the reaction is small, resulting in insufficient post-crosslinking reaction. On the other hand, when the amount exceeds 5 times the equivalent, the functional group such as the carboxylic acid ester moiety is adversely affected by hydrolysis of the ester, formation of a salt by saponification reaction, and the like.

When the alkali treatment is applied in an amount of 0.02 to 5 times the acid value, the residual cation concentration after the treatment is 5 to 1
It is contained between 000 ppm and can be preferably used to define the amount of alkali.

The toner composition according to the present invention has a glass transition temperature (Tg) of 50 to 70 ° C., preferably 55 to 65 ° C. from the viewpoint of storability, and a Tg of lower than 50 ° C. in a high temperature atmosphere. It causes the deterioration of the developer and the offset at the time of fixing. Further, when Tg exceeds 70 ° C., the fixability is adversely affected.

The relationship between Tg _L of the low molecular weight polymer and Tg _H of the high molecular weight polymer of the resin composition according to the present invention is preferably in the range of Tg _L ≧ Tg _H −5 (° C.), and Tg _L Is less than Tg _H −5, the developability tends to be poor. More preferably, Tg _L ≧ Tg _H.

As a method for producing the binder resin according to the present invention, a solution blending method in which a high molecular weight polymer and a low molecular weight polymer are separately synthesized by a solution polymerization method, these are mixed in a solution state, and then a solvent is removed. Also, a dry blending method of melt-kneading with an extruder or the like, further, a low molecular weight polymer obtained by a solution polymerization method or the like is dissolved in a monomer constituting a high molecular weight polymer, suspension polymerization is carried out, and washed with water. -A two-step polymerization method or the like in which the resin is dried to obtain a binder resin can be mentioned. However, the dry blending method has problems in uniform dispersion and compatibility, and the two-step polymerization method has many advantages such as uniform dispersibility, but the low molecular weight component is increased to the high molecular weight component or more. In the presence of a low molecular weight component, which is not possible, it is very difficult to synthesize a sufficient high molecular weight component desired in the present invention, and there is a drawback that unnecessary low molecular weight component is by-produced. The solution blending method is most suitable for application to the present invention.

Polymerization methods that can be used in the present invention as a method for synthesizing the high molecular weight component of the resin composition according to the present invention include solution polymerization method, emulsion polymerization method and 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 with an emulsifier in the aqueous phase and polymerization is carried out using a water-soluble polymerization initiator. . In this method, it is easy to control the heat of reaction, and the phase in which the polymerization takes place (oil phase consisting of polymer and monomer)
And the aqueous phase are different, the termination reaction rate is low, and as a result, the polymerization rate is high and the polymerization degree is high. Further, in the production of toner, due to the relatively simple polymerization process and the fine particles of the polymerization product,
It is advantageous as a method for producing a binder resin for a toner because it can be easily mixed with a colorant, a charge control agent and other additives.

However, the polymer produced is liable to become impure due to the added emulsifier, and an operation such as salting out is required to take out the polymer, and suspension polymerization is convenient in order to avoid this inconvenience.

In 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) is preferable. As the dispersant that can be used, polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, etc. are used, and there is an appropriate amount such as the amount of monomers in the aqueous solvent, but generally 0.05 to 1 per 100 parts by weight of the aqueous solvent. Used in parts by weight. The polymerization temperature is suitably 50 to 95 ° C., but it should be appropriately selected depending on the initiator used and the target polymer.

As the high molecular weight component of the resin composition used in the present invention, in order to achieve the object of the present invention, a polyfunctional polymerization initiator as shown below or a monofunctional polymerization initiator is used in combination.

Specific examples of the polyfunctional polymerization initiator having a polyfunctional structure 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-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxy Azelate, di-t-butylperoxytrimethyl adipate, 2,2-bis- (4,4-di-t-
Butyl peroxycyclohexyl) propane, 2,2-
A polyfunctional polymerization initiator having a functional group having a polymerization initiation function such as two or more peroxide groups in one molecule, such as t-butylperoxyoctane and various polymer oxides, and diallyl peroxydicarbonate, t- In a molecule such as butyl peroxymaleic acid, t-butyl peroxyallyl carbonate and t-butyl peroxyisopropyl fumarate, both a functional group having a polymerization initiation function such as a peroxide group and a polymerizable unsaturated group are contained. Selected from polyfunctional polymerization initiators having.

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

These polyfunctional polymerization initiators are preferably used in combination with a monofunctional polymerization initiator in order to satisfy various performances required as a binder for toner.
In particular, it is preferable to use together with a polymerization initiator having a decomposition temperature lower than the decomposition temperature for obtaining the half-life of 10 hours of the polyfunctional polymerization initiator.

Specifically, benzoyl peroxide,
1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-di (t
-Butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t
-Organic peroxides such as butyl peroxide, 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, but in order to keep the initiator efficiency of the polyfunctional polymerization initiator proper. It is preferably added after the polymerization time has passed the half-life indicated by the polyfunctional polymerization initiator under arbitrary polymerization conditions.

These initiators are 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 component of the resin composition used in the present invention contains a crosslinkable 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 are aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, etc .; Diacrylate compounds; for example, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate,
1,5-Pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and compounds obtained by replacing the acrylates of the above compounds with methacrylates; diacrylate compounds linked by an alkyl chain containing an ether bond. , Such as diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and the acrylates of the above compounds replaced with methacrylate Diacrylate compounds linked by a chain containing an aromatic group and an ether bond, for example, polyoxyethylene (2) -2,2-bis ( - hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,
2-bis (4-hydroxyphenyl) propane diacrylate, and those obtained by replacing the acrylate of the above compounds with methacrylates; further, polyester type diacrylate compounds, for example, trade name MANDA (Nippon Kayaku). . As the polyfunctional crosslinking agent, pentaerythritol acrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, and acrylates of the above compounds into methacrylate. And the like; triallyl cyanurate, triallyl trimellitate; and the like.

These cross-linking agents are based on other monomer components 10
1% by weight or less with respect to 0% by weight, preferably 0.00
It is preferably used in the range of 1 to 0.05% by weight.

Of these crosslinkable monomers, aromatic divinyl compounds (particularly divinylbenzene), aromatic groups and ether bonds are preferably used for the resin for developers from the viewpoints of fixing property and anti-offset property. Examples include chain-containing diacrylate compounds.

When the polymer on the high molecular side which constitutes the resin composition according to the present invention is mixed with a low molecular weight wax in advance, the phase separation in the micro region is alleviated, the high molecular component is not reaggregated, and A good dispersion state with the molecular polymer can be obtained.

As the low molecular weight wax applicable to the present invention, polypropylene, polyethylene, microcrystalline wax, carnauba wax, sazol wax, paraffin wax, higher alcohol wax,
Examples thereof include wax-like substances such as ester wax, and oxides and graft modified products thereof.

The weight average molecular weight of these low molecular weight waxes is preferably 30,000 or less, more preferably 10,000 or less.
The addition amount is preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the binder polymer component.

These low molecular weight waxes are preferably added and mixed in the binder resin in advance during toner production. Particularly preferred is a method in which the low-molecular weight wax and the high-molecular weight polymer are pre-dissolved in a solvent during the production of the binder and then mixed with the low-molecular weight polymer solution.

The solid concentration of the polymer solution depends on the dispersion efficiency,
Considering prevention of deterioration of resin at the time of stirring and operability, 5-70
It is preferably not more than 5% by weight, preferably 5 to 60% by weight or less in the preliminary solution of the high molecular weight polymer component and the polyolefin polymer, and 5 to 70% by weight or less in the low molecular weight polymer solution.

The method of dissolving or dispersing the high molecular weight polymer component and the polyolefin polymer is carried out by stirring and mixing, which may be a batch type or a continuous type.

Then, the method of mixing the low-molecular weight polymer solution is to add 10 to 1000 polymerization parts of the low-molecular weight polymer solution to the solid content of the preliminary solution, and mix with stirring. However, it does not matter if it is a continuous type.

Examples of the organic solvent used for mixing the solution of the resin composition according to the present invention include benzene, toluene,
Hydroxyl solvents such as xylol, solvent naphtha 1, solvent naphtha 2, solvent naphtha 3, cyclohexane, ethylbenzene, solvesso 100, solvesso 150, mineral spirits, methanol, ethanol, iso-propyl alcohol, n-butyl alcohol, Alcoholic solvents such as sec-butyl alcohol, iso-butyl alcohol, amyl alcohol, cyclohexanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ester solvents such as ethyl acetate, n-butyl acetate, cellosolve acetate. Examples of the solvent include ether solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and methyl carbitol. Among these aromatic,
Ketone-based and ester-based solvents are preferred. Moreover, these may be mixed and used.

The organic solvent is removed 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 residual solvent under reduced pressure. At this time, the organic solvent solution has a boiling point of 20% or more of the organic solvent used.
It is necessary to keep the temperature below 0 ° C. If the boiling point of the organic solvent is below the range, not only the efficiency during solvent evaporation is poor, but also unnecessary shearing force is applied to the polymer in the organic solvent, redispersion of each constituent polymer is promoted, and in a micro state. Cause phase separation.
Further, when the temperature exceeds 200 ° C., depolymerization of the polymer proceeds, and not only oligomer formation by molecular cleavage but mixing of residual monomer into the product resin due to monomer formation leads to unsuitable toner binder for electrophotography. Becomes

On the other hand, as a method for synthesizing the low molecular weight component of the binder resin according to the present invention, a known method can be used. However, in the bulk polymerization method, a low molecular weight polymer can be obtained by polymerizing at a high temperature to accelerate the termination reaction rate, but there is a problem that the reaction is difficult to control.
In that respect, in the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in chain transfer of radicals depending on the solvent, and by adjusting the amount of the initiator and the reaction temperature. It is preferable to obtain a low molecular weight product in the resin composition used in the present invention. In particular, minimize the amount of initiator used,
A solution polymerization method under pressure is also effective in that the influence of the residue of the initiator is suppressed as much as possible.

Examples of the comonomer for obtaining the polymer side component of the binder resin used for the developing side of the present invention and the monomer for obtaining the low molecular weight side component include the following.

For example, styrene, o-methylstyrene, m
-Methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene,
Styrene and its derivatives such as p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene and the like; ethylene. Ethylenically unsaturated monoolefins such as propylene, butylene, isobutylene; unsaturated polyenes such as butadiene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride; vinyl acetate, vinyl propionate, Vinyl esters such as vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid. Stearyl, methacryl Α-methylene aliphatic monocarboxylic acid esters such as phenyl, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n acrylate -Acrylic esters such as octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl Vinyl ketones such as methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone Nyl compounds; vinylnaphthalene compounds; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide; and vinyl monomers used alone or in combination of two or more.

Among these, a combination of monomers that forms a styrene-based copolymer or a styrene-acrylic-based copolymer is preferable.

It is preferable that both the low molecular weight component and the high molecular weight component contain at least 65 parts by weight of the styrene polymer component. By thus containing 65 parts by weight or more of each of the styrene-based components, the mixing property is improved.

The toner used in the present invention is preferably a magnetic toner containing a magnetic substance, the magnetic substance is preferably magnetic iron oxide, and further preferably contains a silicon element.

The content of silicon element in the magnetic iron oxide used for the magnetic toner is 0.1 to 5.0% by weight, preferably 0.4 to 2.0% by weight (more preferably, based on the iron element). 0.5 to 0.9% by weight) is preferable.

By containing silicon element in the magnetic material, the fluidity of the toner is excellent, and as a result, the charging of the toner is stabilized and the durability of the toner is improved. Further, the toner containing the magnetic material containing the silicon element has a very soft polishing effect on the surface of the latent image carrier, and even if the toner is about to adhere to the surface of the latent image carrier, It is appropriately polished and has the effect of improving the durability of the latent image carrier.

The amount of silicon element in the magnetic iron oxide particles was determined by the fluorescence X
Line analyzer SYSTEM3080 (Rigaku Denki Kogyo Co., Ltd.)
(Manufactured by Mitsui Chemicals Co., Ltd.) and in accordance with JIS K0119 “General rules for fluorescent X-ray analysis”.

The magnetic iron oxide particles used in the magnetic toner of the present invention are preferably used in an amount of 20 to 200 parts by weight based on 100 parts by weight of the binder resin. It is more preferable to use 30 to 150 parts by weight.

In some cases, the magnetic iron oxide particles used in the magnetic toner of the present invention may be treated with a silane coupling agent, a titanium coupling agent, titanate, aminosilane, an organic silicon compound or the like.

The toner for electrostatic image development used in the present invention contains carbon black, which is conventionally known, as a colorant.
Pigments or dyes such as copper phthalocyanine can be used.

The toner for developing an electrostatic charge image of the present invention may contain a charge control agent. In the case of a negatively chargeable toner, a metal complex salt of monoazo dye, a metal of salicylic acid, an alkylsalicylic acid, a dialkylsalicylic acid or a naphthoic acid is used. A negative charge control agent such as a complex salt is used.

For example, as the negative charge control agent,

[0106]

[Outside 7] The following three types are more effective as the negative charge control agent to be combined with the magnetic iron oxide used in the present invention.

[0107]

[Outside 8] [In the formula, X ₁ , X ₂ ; hydrogen atom, lower alkyl group, lower alkoxy group, nitro group, halogen atom m, m ′; 1-3 integer Y ₁ , Y ₃ ; hydrogen atom, C ₁ -C ₁₈ Alkyl, alkenyl, sulfonamide, mesyl, sulfonic acid, carboxy ester, hydroxy, C ₁ -C ₁₈ alkoxy, acetylamino, benzoyl, amino group, halogen atom n, n ′; 1-3 integers Y ₂ , Y ₄ ; Hydrogen atom, nitro group (X ₁ and X ₂ , m and m ′, Y ₁ and Y ₃ , n and n ′, Y ₂ and Y ₄ may be the same or different)

[0108]

[Outside 9] Monoazo iron complex salt

[0109]

[Outside 10]

Compounds of an aromatic hydroxycarboxylic acid, aromatic diol or aromatic dicarboxylic acid derivative having the above general formula with an iron atom

[0111]

[Outside 11] [In the formula, Y ¹ , Y ² ; phenyl group, naphthyl group, anthryl group R ¹ , R ² ; halogen atom, nitro group, sulfonic acid group,
Carboxyl group, carboxylic ester group, cyano group, carbonyl group and alkyl group, alkoxy group, amino group R ³ , R ⁴ ; hydrogen atom, alkyl group, alkoxy group, optionally substituted phenyl group, substituent An aralkyl group and an amino group which may have R ⁵ and R ⁶ ; a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms k, j; an integer of 0 to 3 (at the same time, not 0) m, n; 1 or 2 (Y ¹ and Y ² , R ¹ and R ² , R ³ and R ⁴ , R ⁵ and R ⁶ , k and j, and m and n may be the same or different)

NN′-bisarylurea derivatives having the above general formula

[0113]

[Outside 12] The monoazo iron complex represented by

Although the details are not clear, the use of the above-mentioned negative charge control agent and the acid component-adjusted polymer component used in the present invention tends to improve the image quality characteristics, particularly fog. It has been confirmed.

Specific examples of the positive charge control agent include, for example,
Modified products of nigrosine and fatty acid metal salts and the like; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium such as phosphonium salts which are analogs thereof. Salts and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (as a laking agent, phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, and ferricyanide). Russian compounds, etc.); metal salts of higher fatty acids, acetylacetone metal complexes; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate,
Examples thereof include diorgano tin borate such as dioctyl tin borate and dicyclohexyl tin borate, and these can be used alone or in combination of two or more kinds. Among these, charge control agents such as nigrosine and quaternary ammonium salts are particularly preferably used.

The amount of these charge control agents used is 0.1 to 100 parts by weight of the binder resin in view of the amount of charge of the toner.
5.0 parts by weight is preferred.

Further, the toner for developing an electrostatic charge image of the present invention is preferably mixed with an inorganic fine powder or a hydrophobic inorganic fine powder. For example, it is preferable to use fine silica powder or fine titanium oxide powder alone or in combination.

The fine silica powder used in the present invention includes both so-called dry process produced by vapor phase oxidation of a silicon halogen compound or dry silica called fumed silica and so-called wet silica produced from water glass. Although usable, dry silica, which has few silanol groups on the surface and inside and has no production residue, is preferable.

Further, the silica fine powder used in the present invention is preferably hydrophobized. To make hydrophobic treatment,
It is provided by chemically treating with an organic silicon compound or the like that reacts with or physically adsorbs on silica fine powder. As a preferred method, a method of treating dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound with a silane coupling agent, or simultaneously treating with a silane coupling agent and an organosilicon compound such as silicone oil Is mentioned.

Examples of the silane coupling agent used for the hydrophobic treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyl. Dichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane,
Chlormethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldimethyl Examples include siloxane and 1,3-diphenyltetramethyldisiloxane.

Examples of the organic silicon compound include silicone oil. As a preferable silicone oil, one having a viscosity of about 30 to 1,000 centistokes at 25 ° C. is used, and for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified. Silicone oil and the like are preferred.

As the method for treating silicone oil, for example, silica fine powder treated with a silane coupling agent and silicone oil may be directly mixed by using a mixer such as a Henschel mixer. The method of injecting Alternatively, it may be produced by dissolving or dispersing silicone oil in an appropriate solvent, mixing with silica fine powder of the base, and removing the solvent.

Further, a preferred system for hydrophobizing the silica fine powder used in the present invention is a method prepared by treating with dimethyldichlorosilane, then with hexamethyldisilazane, and then with silicone oil. Can be mentioned.

As described above, it is preferable that the silica fine powder is treated with two or more kinds of silane coupling agents and then treated with oil, because the degree of hydrophobicity can be effectively increased.

Those obtained by subjecting the above-mentioned silica fine powder to the hydrophobic treatment and further the oil treatment to the titanium oxide fine powder can also be used in the present invention, and are preferred similarly to the silica-based powder.

If necessary, an external additive other than silica fine powder may be added to the toner for developing an electrostatic image in the present invention.

For example, a charging auxiliary agent, a conductivity-imparting agent, a fluidity-imparting agent, an anti-caking agent, a releasing agent at the time of heat roll fixing,
Resin fine particles or inorganic fine particles that act as a lubricant, an abrasive, etc.

The resin fine particles have an average particle size of 0.
It is preferably from 03 to 1.0 μm, and the polymerizable monomer constituting the resin is styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, or the like. Styrene monomer, methacrylic acid such as acrylic acid and methacrylic acid,
Methyl acrylate / ethyl acrylate / acrylic acid n-
Butyl / isobutyl acrylate / n-propyl acrylate / n-octyl acrylate / dodecyl acrylate / 2-ethylhexyl acrylate / stearyl acrylate /
Acrylic esters such as 2-chloroethyl acrylate and phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n methacrylate
-Octyl / dodecyl methacrylate / methacrylic acid 2-
Methacrylic acid ester such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. Other acrylonitrile, methacrylonitrile,
Examples include monomers such as acrylamide.

As the polymerization method, suspension polymerization, emulsion polymerization,
Soap-free polymerization and the like can be used, but particles obtained by soap-free polymerization are more preferable.

In particular, it has been confirmed that the resin fine particles having the above characteristics have a great effect on the fusing of the drum in a contact charging system such as a roller, a brush or a blade as a primary charging device.

As the other fine particles, lubricants such as Teflon, zinc stearate, polyvinylidene fluoride, and polyvinylidene fluoride are preferable. Alternatively, abrasives such as cerium oxide, silicon carbide, and strontium titanate are preferable, and strontium titanate is particularly preferable. Alternatively, for example, a fluidity-imparting agent such as titanium oxide or aluminum oxide, among which a hydrophobic agent is particularly preferable. A small amount of an anti-caking agent, or a conductivity-imparting agent such as carbon black, zinc oxide, antimony oxide, tin oxide, etc., or white and black fine particles of opposite polarity can be used as a developing property improver.

The resin fine particles, the inorganic fine powder, the hydrophobic inorganic fine powder, or the like mixed with the toner are the magnetic toner 100.
0.1 to 5 parts by weight (preferably 0.1 to 5 parts by weight)
~ 3 parts by weight) should be used.

To prepare the electrostatic charge image developing toner for developing an electrostatic charge image according to the present invention, the polymer component of the present invention and a pigment as a colorant, a dye or a magnetic substance, a charge control agent, and the like. The additives and the like are thoroughly mixed with a mixer such as a ball mill, and then melted, kneaded and kneaded with a heat kneader such as a heating roll, kneader, and extruder to make the resins compatible with each other. The toner for developing an electrostatic charge image according to the present invention can be obtained by dispersing or dissolving a pigment or a dye, cooling and solidifying, and then pulverizing and strictly classifying.

As another method for obtaining the toner for developing an electrostatic charge image according to the present invention, the toner can be manufactured by a polymerization method. This suspension polymerization method toner comprises a polymerizable monomer, the charge control agent of the present invention, a pigment or a dye,
After magnetic iron oxide and a polymerization initiator (and optionally a crosslinking agent and other additives) are uniformly dissolved or dispersed to obtain a monomer composition, the monomer composition or the monomer A composition obtained by preliminarily polymerizing the composition is dispersed in a continuous phase (for example, water) containing a dispersion stabilizer using a suitable stirrer, and at the same time, a polymerization reaction is performed to obtain toner particles having a desired particle size. is there. When the magnetic iron oxide used in the present invention is used in the polymerization method, it is preferably subjected to a hydrophobic treatment in advance.

The electrostatic latent image carrier used in the present invention has a laminated structure composed of at least a conductive support, a charge generation layer and a charge transport layer, and the surface layer of the electrostatic latent image carrier contains fluorine and / or Alternatively, it preferably has a silicon atom.

Examples of the fluorine compound used in the present invention include known fluorine resins, such as tetrafluoroethylene, trifluoroethylene chloride, hexafluoropropylene, vinyl fluoride, vinylidene fluoride and difluorodichloride. One or more selected from homopolymers of ethylene and the like and copolymers thereof are appropriately selected. Further, carbon fluoride or the like can also be used.

In the present invention, a block or graft polymer containing a fluorine-based polymer or a fluorine-based segment synthesized from a copolymerization with a non-fluorine-based polymerizable monomer, a graft polymer, a surfactant, a macromonomer, etc. Can be used alone or in combination with the above fluororesins.

Specific examples of the silicon compound include monomethylsiloxane three-dimensional crosslinked products and dimethylsiloxane-
A monomethylsiloxane three-dimensional crosslinked product, an ultrahigh molecular weight polydimethylsiloxane, a block polymer containing a polydimethylsiloxane segment, a graft polymer, a surfactant, a macromonomer, a terminal-modified polydimethylsiloxane, etc. are used. In the case of a three-dimensional crosslinked product, the particle size used in the form of fine particles can be used in the range of 0.01 to 5 μm. In the case of a polydimethylsiloxane compound, its molecular weight is preferably in the range of 3,000 to 5,000,000.

The fine particles are dispersed as a photosensitive layer composition together with a binder resin.

The fluorine compound and the silicon compound used in the present invention are 50% in the organic photosensitive layer (OPC) composition.
The following amounts are preferably used. More preferably 0.5
% To 50%.

The presence of fluorine and / or silicon atoms in the surface layer of the electrostatic latent image bearing member has the effect of lowering the energy of the surface of the electrostatic latent image bearing member, making it difficult for the toner to adhere. If the blending amount is too large, the friction coefficient with the cleaning member will be too low, which will cause the toner to slip through and cause cleaning failure.

An example of the image forming apparatus is schematically shown in FIG. 2, and the image forming method will be described based on it.

Reference numeral 1 denotes a rotary drum-shaped electrostatic latent image carrier around which a primary charging device 2, an exposure optical system 3, a developing device 4 having a toner carrier 5, a transfer device 9 and a cleaning device 11 are provided. It is arranged.

In this image forming apparatus, the surface of the electrostatic latent image carrier 1, which is a photoconductor, is uniformly charged by the primary charging device 2, and the electrostatic latent image carrier is imagewise exposed by the exposure optical system 3. An electrostatic latent image is formed on the surface of 1.

Next, a toner coat layer is formed on the surface of the toner carrier 5 containing a magnet by the toner layer thickness regulating member 6 according to the constitution of the present invention, and the electrostatic latent image carrier 1 is electrically conductive in the developing section. The electrostatic latent image formed on the electrostatic latent image carrier 1 is developed while the bias applying means 8 applies an alternating bias, a pulse bias and / or a DC bias between the conductive substrate and the toner carrier 5.

The developed toner image is electrostatically transferred onto the transfer paper P by carrying the transfer paper P and applying a charge having a polarity opposite to that of the toner from the back surface of the transfer paper P by the transfer device 9 and the voltage applying means 10. .

The transfer paper P on which the toner has been transferred is passed through the heating and pressure roller fixing device 12 to obtain a fixed image.

The magnetic toner remaining on the latent image carrier after the transfer step is removed by the cleaning device 11, and the steps of primary charging and below are repeated again.

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

(Production of Resin Composition ) Synthesis of Low-Molecular Weight Polymer (L-1) 300 parts by weight of xylene was placed in a four-necked flask, the inside of the container was sufficiently replaced with nitrogen while stirring, and then the mixture was heated. Warm to reflux.

Under this reflux, a mixed solution of 75 parts by weight of styrene, 18 parts by weight of -n-butyl acrylate, 7 parts by weight of monobutyl maleate and 2 parts by weight of di-tert-butyl peroxide was added dropwise over 4 hours. After that, the mixture was held for 2 hours to complete the polymerization, and a low molecular weight polymer (L-1) solution was obtained.

A portion of this polymer solution was sampled,
Low molecular weight polymer (L-1) obtained by drying under reduced pressure
GPC and glass transition point (Tg) were measured, and weight average molecular weight (Mw) = 9,600, number average molecular weight (Mn) = 6,000, peak molecular weight (PMw) =
It was 8,500, Tg = 62 ° C., and an acid value of 25.

At this time, the polymer conversion rate 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 placed in a four-necked flask, and then 70 parts by weight of styrene and acrylic acid 25 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-t).
ert-Butylperoxycyclohexyl) propane (half-life 10 hours temperature; 92 ° C.) (0.1 parts by weight) was added and the mixture was stirred to give a suspension.

After thoroughly replacing the inside of the flask with nitrogen,
The temperature was raised to 5 ° C to initiate polymerization. After keeping the same temperature for 24 hours, 0.1 part by weight of benzoyl peroxide (half-life 10 hours temperature; 75 ° C.) was added additionally. Furthermore,
Hold for 12 hours to complete the polymerization.

To the suspension after completion of the reaction was added an aqueous solution of NaOH which was 6 times equivalent to the acid value (AV = 7.8) of the obtained high molecular weight polymer (H-1), and the mixture was stirred for 2 hours. It was

The high molecular weight polymer (H-1) was separated by filtration, washed with water, dried, and analyzed, whereupon Mw = 1.8 million, P
The Mw was 1.2 million, the Tg was 62 ° C., and the acid value was 6.

Production of binder 100 parts by weight of xylene, 25 parts by weight of the above high molecular weight polymer (H-1) and 4 parts by weight of polypropylene (Mw = 6,000) were placed in a four-necked flask, and the temperature was raised. Then, the mixture is stirred under reflux to carry out preliminary dissolution. After maintaining in this state for 12 hours, a uniform preliminary solution (Y-1) of the polymer (H-1) and polypropylene was obtained.

A portion of this preliminary lysate was sampled,
When it was dried under reduced pressure and the glass transition point of the obtained solid content was measured, it was 61 ° C.

On the other hand, the low molecular weight polymer (L-
300 parts by weight of the homogeneous solution of 1) is added and refluxed.

The above-mentioned preliminary solution (Y-1) and the low molecular weight polymer (L-1) solution were mixed under reflux, the organic solvent was distilled off, and the obtained resin was cooled, solidified and then ground. Resin 1 for toner was obtained.

When the resin 1 was analyzed, PMw = 11
The area ratio in the molecular weight distribution of GPC of the resin composition having a molecular weight of 100,000 and 1,000,000 or more is 9.2%, Tg = 62.5 ° C.,
The THF insoluble content was 2.1% by weight.

In the same manner, the amounts of monobutyl maleate, styrene, n-butyl acrylate and the amount of initiator were adjusted to obtain Resins 2 to 8 and Comparative Resin 1 shown in Table 1.

[0164]

[Table 1]

(Production of Magnetic Iron Oxide Particles) An aqueous ferrous sulfate solution was mixed with 0.95 equivalent of an aqueous sodium hydroxide solution with respect to Fe ²⁺ , and then ferrous iron containing Fe (OH) ₂ was mixed. An aqueous salt solution was produced.

After that, sodium silicate was added to the iron element so as to be 1.0% in terms of silicon element. Next, magnetic iron oxide particles containing elemental silicon were generated by aerating the aqueous ferrous salt solution containing Fe (OH) ₂ with air at a temperature of 90 ° C. to cause an oxidation reaction.

Furthermore, 0.1% sodium silicate was added to this suspension.
An aqueous sodium hydroxide solution in which (iron element converted to silicon element) is added in an amount of 1.05 equivalent to the residual Fe ²⁺ , and further heated at a temperature of 90 ° C. to oxidize and contain silicon element. Magnetic iron oxide particles were produced.

The produced magnetic iron oxide particles are washed, filtered and dried by a conventional method, and then the agglomerated magnetic iron oxide particles are crushed (consolidated crushing treatment with a mix muller),
Magnetic iron oxide particles 1 were obtained. The particle size is 0.21 μm, the silicon element content is 1.09%, and the surface SiO ₂ amount is 0.19.
%, Smoothness 0.53, bulk density 1.10 g / cm ³ , BE
T specific surface area 10.0 m ² / g, total pore volume 1.1 × 10
^The specific surface area was ^-2 ml / g, the micropore specific surface area was 4.8 m ² / g, and the mesopore specific surface area was 5.3 m ² / g.

(Production of Toner) Resin 1 100 parts by weight Magnetic Iron Oxide 1 100 parts by weight Negative charge control agent (the following formula) 2 parts by weight

[0170]

[Outside 13]

The above mixture was melt-kneaded with a twin-screw extruder heated to 140 ° C., the cooled kneaded product was coarsely pulverized with a hammer mill, and the coarsely pulverized product was finely pulverized with a jet mill. Was classified with a fixed wall type air classifier to produce classified powder. Further, the weight-average particle size (D4) 6 of the obtained classified powder is strictly classified at the same time by using a multi-division classifier utilizing the Coanda effect (Elbow Jet classifier manufactured by Nittetsu Mining Co., Ltd.) 0.7 μm (particle size 12.7 μ
A negatively chargeable magnetic toner having a magnetic toner particle content of m of 0.2%) was obtained.

100 parts by weight of this magnetic toner and 1.2 parts by weight of hydrophobic silica fine powder (BET 300 m ² / g) which had been treated with dimethyldichlorosilane, then with hexamethyldisilazane, and then with dimethyl silicone oil. , And 0.2 parts by weight of styrene-acrylic fine particles (average particle diameter of 0.05 μm) obtained by soap-free polymerization were mixed with a Henschel mixer to prepare a magnetic developer (toner No. 1).

Toners 2 to 8 and Comparative Toner 1 were prepared in the same manner except that the resin species used below and the compounding amount of magnetic iron oxide were changed. Table 2 shows the correspondence between the toner and the resin used and the physical properties of the resin component when made into toner. In addition, Table 3 shows the acid value of the toner.

[0174]

[Table 2]

[0175]

[Table 3]

[0176]

Example 1 Using toner 1, a laser beam printer LBP-A304GII manufactured by Canon was remodeled from 8 sheets / min to 25 sheets / min for printing and evaluation was performed. The process speed at this time was 110 mm / sec.

FIG. 1 is a schematic view showing an example of an embodiment of a contact charging device according to the present invention. In FIG. 1, 1 is an electrostatic latent image carrier, 2 is a charging member, and in this embodiment, 1 is an organic photoconductor (OPC) drum and 2 is a roller-shaped charging roller.

As an organic photoconductor (OPC) drum,
Tetrafluoroethylene-hexafluoropropylene copolymer fine powder (emulsion-polymerized fine powder having an average particle diameter of 0.32 μm) was formed on the outermost layer of the organic photoconductor (OPC) layer.
Photoreceptor A having an amount of 5% dispersed in the total composition of the organic photoconductor (OPC) layer was used.

As the charging roller, a metal cored bar 2a is used.
And a lower layer portion 2b formed on the outer periphery of the core metal and an upper layer portion 2c formed on the outer periphery of the lower metal layer 2b. In this embodiment, the outer diameter is 15 mm (core metal 2a diameter 8 mm, upper layer 2c thickness 150 μm) was used. Further, the hardness of the charging roller is 45 ° in ASKER-C (ASKER-C
Using a C hardness tester 100, the average value was obtained by measuring a total of 9 points on each of the three points on the center and left and right under a load of 500 g.

In the present embodiment, the contact charging device according to the present invention has the charging roller 2 that comes into contact with the photosensitive drum 1 with a predetermined pressure, and is driven to rotate in the direction of the arrow as the photosensitive drum 1 rotates. . The charging roller 2 has a voltage (V _ac + V) obtained by superimposing an AC voltage V _ac and a DC voltage V _dc from the power supply unit 3.
_dc; V _dc = -700V, the peak voltage V _pp = 1500
V, frequency Vf = 1000 Hz) was applied, and the photosensitive drum 1 was uniformly charged to V _D = −700V.

At this time, the charging sound due to the vibration of the charging roller 2 and the photosensitive drum 1 was at a level where there was no problem in practical use. The then charged surface of the photosensitive drum 1, by scanning a laser beam of minute spots according to an image pattern to form an electrostatic latent image of the V _L = -170V, AC bias f = 1800Hz, V _pp = 1400V , And DC bias V _dc = −500 V were applied between the developing sleeve carrying toner and the electrostatic latent image on the OPC surface to develop a toner image.

The formed toner image is transferred by applying a positive charge from the back of the transfer paper by a transfer device in which a transfer roller having a conductive elastic layer is brought into contact with the OPC drum at a contact pressure of 50 g / cm, and further transferred. A fixed image was obtained by passing through a heat and pressure roller fixing device. At this time, the surface temperature of the heating roller of the heating and pressure roller fixing device was set to 185 ° C., the total pressure between the heating roller and the pressure roller was set to 5.5 kg, and the nip was set to 4 mm.

Under the above setting conditions, low temperature and low humidity (15 ° C / 1
An image output test was performed in an environment of 0% RH. The print speed was 2 sheets / 20 sec.

In a low temperature and low humidity environment, after taking an initial sample, nine solid squares of 5 mm square (3 rows, 3 columns) were used.
The image of (column) was continuously printed on 100 sheets to obtain an image for evaluation of fixing property. Then, the toner was replenished successively and the durability of 20,000 sheets was performed.

(Evaluation) (1) Image Density An image of 9 solid 5 mm squares (3 rows and 3 columns) was printed on ordinary plain paper for copying (75 g / m ² ) and the "Macbeth reflection densitometer was used. (Manufactured by Macbeth Co., Ltd.) was used to measure the relative density of the printed image of a white background portion having a document density of 0.00.

(2) Fixability After the initial sample was taken in a low temperature and low humidity environment, 5
100 mm square solid black images (3 rows and 3 columns)
Using a sample printed on one sheet, a fixed image was rubbed with a soft thin paper under a load of 50 g / cm ² , and the worst value of the reduction rate of the image density before and after the rubbing was evaluated as follows.

⊚ (excellent): less than 5% ○
(Good): 5% to less than 10% △ (Fair): 10% to less than 20% × (No): 20% or more

(3) Anti-Offset Property The anti-offset property was evaluated by printing out a sample image having an image area ratio of about 5% and measuring the degree of stain on the image.

⊚ (excellent): not generated ○ (good):
Very slight occurrence Δ (OK): Slight occurrence X (Not possible): Stain on the image is noticeable

(4) Charging Sound The charging sound during printing was heard and evaluated at a distance of 50 cm from the main body.

◎ (excellent): I do not care at all ○ (good):
Almost unnoticeable △ (OK): A little worried × (No): Quite worried

(5) Toner sticking to the surface of the photosensitive drum Visual evaluation and image evaluation were carried out after the end of the 20,000-sheet running.

⊚ (excellent): Not generated ◯ (Good): Slightly generated, but does not affect the image Δ (Fair): Sticking is noticeable but has little effect on the image × (Failure): Sticking is remarkable Table 4 summarizes the above results.

Example 2 Evaluations were made in the same manner as in Example 1 except that the charging roller was changed to one having a hardness of 59 ° and the toner 2 was used.

Examples 3 to 6 Evaluations were performed in the same manner as in Example 1 except that Toners 3 to 6 were used.

Examples 7 and 8 As photosensitive drums, spherical spherical three-dimensional crosslinked polysiloxane fine powder (average particle size 0.29 μm) was used as an organic photoconductor (OPC) on the outermost layer of the organic photoconductor (OPC) layer. ) Evaluation was performed in the same manner as in Example 1 except that the photoconductor B in which 10% of the total composition of the layer was dispersed and the toners 7 and 8 were used, respectively.

Example 9 The procedure of Example 1 was repeated except that the photoconductor C was obtained by removing the fluorine-containing resin fine particles from the photoconductor A as the photoconductor drum.
An evaluation was made.

Table 4 is a summary of the above results.

The results of Examples 1 to 9 show that the level of the charging sound is good, the image characteristics and durability stability are good, and the fixing property, the anti-offset property, and the toner fixing to the drum are excellent. .

Comparative Examples 1 and 2 Evaluations were made in the same manner as in Example 1 except that charging rollers having hardnesses of 70 ° and 62 ° were used.

Comparative Example 3 Evaluation was carried out in the same manner as in Example 1 except that Comparative Toner 1 was used.

Table 4 shows the above results.

In Comparative Examples 1 and 2, the level of the charging sound was poor,
It wasn't practical. Further, in Comparative Example 1, a high contact pressure was required in order to produce a nip of 4 mm, and thus the amount of abrasion of the drum surface layer after the endurance of 20,000 sheets was large, resulting in point-like fusion.

In Comparative Example 3, since the toner acid value was low, the level of toner sticking to the drum surface was extremely low.

[0205]

[Table 4]

[0206]

According to the present invention, the hardness of the charging member is set to ASKER.
By setting the temperature at -C to 60 ° or less and introducing an acid value into the polymer component in the toner composition, charging noise is not generated,
It is possible to provide an image forming method capable of fixing at a lower temperature than before, excellent in offset resistance, less likely to deteriorate due to toner sticking to an electrostatic latent image carrier, and capable of long-term durability.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an example of a charging device used in an image forming method of the present invention.

FIG. 2 is a diagram schematically showing an example of an image forming apparatus used in the image forming method of the present invention.

[Explanation of symbols]

1 latent image carrier (1a substrate 1b organic photoconductor (O
PC layer) 2 charging member (2a core metal 2b conductive elastic layer 2c
High resistance layer) 3 Bias power supply device 4 Developing device 5 Toner carrier 6 Toner layer thickness regulating member 7 Toner stirring means 8 Developing bias power supply 9 Transfer device 10 Transfer current generating device 11 Cleaning means 12 Fixing device 13 Toner

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 27, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0205

[Correction method] Change

[Correction content]

[0205]

[Table 4]

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G03G 9/083 15/02 101 G03G 9/08 325 (72) Inventor Masaichiro Katada 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc.

Claims (12)

[Claims] 1. A step of applying a voltage having at least an AC component to a charging member and bringing the charging member into contact with the latent image carrier to charge the surface of the latent image carrier, forming an electrostatic latent image. In the image forming method including the step of developing the electrostatic latent image with toner, the charging member constitutes an upper layer portion made of a high resistance material that contacts a member to be charged, and a lower layer of the upper layer portion, and at least AC And a conductive lower layer portion to which a voltage having a component is applied, and the hardness of the charging member is ASKER.
-C is 60 ° or less, the toner is formed of a composition containing at least a polymer component and a charge control agent,
An image forming method, wherein the polymer component of the composition has an acid value of 1 mgKOH / g or more. 2. A GPC chromatogram of a polymer component of the composition, which is a) substantially free of THF-insoluble matter, and b) THF-soluble matter of the polymer component, has a molecular weight of 3 × 10 ^{3 to} 3. It has a main peak in the region of × 10 ⁴ and has a molecular weight of 1 × 10 ^{5 to} 3 × 10 ^6.
Having a sub-peak or shoulder in the region of: c) low molecular weight polymer (in GPC chromatogram,
Acid value (A _VL ) of molecular weight 5 × 10 ^{4 or} less) and high molecular weight polymer (molecular weight 5 × in GPC chromatogram)
The image forming method according to claim 1 or 2, wherein the relationship of the acid value (A _VH ) of 10 ⁴ or more) is A _VL > A _VH . 3. The GPC chromatogram of a low molecular weight polymer as a polymer component of the composition has an acid value (A _VL ) in the region of a molecular weight of less than 5 × 10 ⁴ of 21 to 35 mgKOH / g and a high molecular weight In the GPC chromatogram of the combined component, the acid value (A _VH ) in the region having a molecular weight of 5 × 10 ⁴ or more is 0.5 to 11 mgKOH / g, and the difference is 10 ≦ (A _VL −A _VH ) ≦ 27. The image forming method according to claim 1, wherein the image forming method is 27. 4. The glass transition point (Tg) of the composition is 50.
˜70 ° C. and Tg of the low molecular weight polymer of the composition
The image forming method according to claim 1, wherein the relationship between _L and Tg _H of the high molecular weight polymer is in the range of Tg _L ≧ Tg _H −5. 5. The composition has a Tg of 55 to 65 ° C.,
The image forming method according to claim 1, wherein the relationship between Tg _L of the low molecular weight polymer and Tg _H of the high molecular weight polymer of the composition is in the range of Tg _L ≧ Tg _H. 6. The image forming method according to claim 1, wherein the polymer component of the composition satisfies the following formula. [Outside 1] 7. The image forming method according to claim 1, wherein both the low molecular weight and high molecular weight polymer components of the composition contain at least 65 parts by weight of a styrene-based monomer component unit. . 8. The high molecular weight polymer component of the composition is a polymer polymerized with a polyfunctional polymerization initiator.
The image forming method according to any one of 1. 9. The polymer according to claim 1, wherein the high molecular weight polymer component of the composition is a polymer polymerized by using at least a polyfunctional polymerization initiator and a monofunctional polymerization initiator in combination. The image forming method described. 10. In a chromatogram of GPC measured by a THF-soluble content of a polymer component in the composition,
The image forming method according to claim 1, wherein a polymer component having a molecular weight of 1,000,000 or more is contained in an amount of 3% or more. 11. The toner according to claim 1, wherein the toner is a magnetic toner containing a magnetic material, the magnetic material is magnetic iron oxide particles, and the magnetic iron oxide particles contain silicon element. The image forming method described. 12. The latent electrostatic image bearing member has a laminated structure having at least a conductive support, a charge generation layer and a charge transporting layer, and a fluorine atom and silicon are contained in a surface layer of the latent electrostatic image bearing member. The image forming method according to claim 1, which has atoms or both.