JPH05204183A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To ensure stable triboelectric chargeability in various environments by using amorphous fine titanium oxide particles having a specified primary average particle diameter as an additive. CONSTITUTION:Amorphous fine titanium oxide particles having 1-200mmu primary average particle diameter are used as an additive. The average particle diameter of the primary particles is preferably 1-100mmu, more preferably 1-50mmu, further preferably 1-40mmu and most preferably 10-30mmu. The amorphous fine titanium oxide particles stuck on the surfaces of colorant-contg. resin particles have 5-150 average particle diameter of the primary particles, secondary particles, tertiary particles, etc., and the resulting toner preferably has 0.35-0.5g/cm<3> bulk density, 2-15% degree of aggregation and 4-10mum weight average particle diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
The present invention relates to an electrostatic charge image developing toner for developing an electrostatic charge image in an image forming method such as electrostatic printing.

[0002]

BACKGROUND OF THE INVENTION The formation and development of images on the surface of photoconductive materials by electrostatic means is well known in the art.

US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-2.
Many methods are known, such as Japanese Patent No. 4748. Generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then toner is attached onto the latent image to form a toner image corresponding to the electrostatic latent image. ..

Then, if necessary, the toner is transferred onto the surface of the image support such as paper, and then fixed by heating, pressurizing, heating and pressurizing or solvent vapor to obtain a copy. When there is a step of transferring the toner image, a step for removing the residual toner is usually provided.

A developing method for visualizing an electric latent image with toner, for example, a powder cloud method described in US Pat. No. 2,221,776, US Pat. No. 2,618,55.
No. 2, cascade development method, US Pat. No. 2,874,063, magnetic brush method, and US Pat. No. 3,909,258, conductive. A method using a magnetic toner is known.

As the toner applied to these developing methods, a toner obtained by mixing and dispersing a colorant in a thermoplastic resin and then pulverizing it is generally used. Polystyrene resin is the most common thermoplastic resin, but polyester resin, epoxy resin, acrylic resin, urethane resin, etc. are also used. Carbon black is most widely used as the colorant, and iron oxide-based black magnetic powder is often used in the case of magnetic toner. In the case of a system using a two-component developer, the toner is usually used as a mixture with carrier particles such as glass beads, iron powder and ferrite particles.

The toner image on the final copy imaging support, such as paper or a transparent film for overhead projectors (hereinafter "OHP film"), is permanently applied to the support by heat, pressure or heat and pressure. It is fixed. Conventionally, this fixing step is often adopted by heating and pressing.

In recent years, the development from mono-color copying to full-color copying is rapidly progressing in copying machines and the like, and two-color copying machines and full-color copying machines have been studied and put into practical use. For example, “Journal of the Electrophotographic Society”, Vol. 22,
No. 1 (1983) and "Journal of the Electrophotographic Society" Vol. Two
5, No. 1, P52 (1986), there are reports on color reproducibility and gradation reproducibility.

Color image formation by full-color electrophotography generally reproduces all colors using color toners of three primary colors of yellow, magenta and cyan.

The method is as follows. First, the light from the original is passed through a color separation light transmitting filter having a complementary color relationship with the color of the toner to form an electrostatic latent image on the photoconductive layer, and then a developing step and a transferring step are performed. Are held on a support. Repeat this step multiple times, matching the registration,
After the toners are superposed on the same support, the final full-color image is obtained by fixing once.

Generally, in the case of a developing system using a so-called two-component type developer in which the developer is composed of a toner and a carrier, the toner is charged to a required charge amount and charge polarity by friction with the carrier, and the toner is statically charged. The electrostatic image is developed with toner by using the electric attraction. Therefore, in order to obtain a good visible image, it is necessary that the triboelectric chargeability of the toner is mainly determined by the relationship with the carrier.

To solve the above problems, the search for carrier core agents and carrier coating agents and the optimization of the coating amount, or the examination of charge control agents and fluidity imparting agents to be added to toners, and the binder serving as the base material Many studies have been made to achieve excellent triboelectrification property in the material constituting the developer, such as improvement of the above.

For example, Japanese Patent Publication No. 52-32256 has been proposed as a technique for adding a charging auxiliary agent such as chargeable fine particles to a toner, and Japanese Patent Laid-Open No. 56-6435.
JP-A No. 61-160760 proposes to use a resin fine powder having a polarity opposite to that of the toner, and a fluorine-containing compound is added to the developer to provide stable triboelectric charging property. Has been proposed.

Further, various methods have been proposed as a method for adding the charging auxiliary agent as described above. For example, a method of attaching the toner particles to the surface of the toner particles by an electrostatic force or a Van der Waals force between the charge assisting agent is generally used,
At that time, stirring, a mixer or the like is used. However, in this method, it is not easy to uniformly disperse the additive on the surface of the toner particle, and avoid the existence of the additive in a free state because the additive does not adhere to the surface of the toner particle and the additives become aggregates. Is difficult. This tendency becomes more remarkable as the specific electric resistance of the charging aid increases and the particle size decreases. In such a case, the performance of the toner is affected. For example, the triboelectric charge amount becomes unstable, the image density is not constant, and an image with a lot of fog is likely to be formed. Further, when continuous copying is performed, there is a problem that the content of the charging aid changes and the image quality at the initial stage cannot be maintained.

As another addition method, there is a method in which a charging auxiliary agent is added in advance together with the binder resin and the colorant at the time of manufacturing the toner. However, it is not easy to make the charge control agent uniform, and it is in the vicinity of the toner particle surface that practically contributes to the chargeability, and the charge auxiliary agent and charge control agent present inside the particle contribute to the chargeability. Therefore, it is not easy to control the addition amount of the charging aid and the dispersion amount on the surface. Even in the toner obtained by such a method, the triboelectric charge amount of the toner is unstable, and it is not easy to obtain a toner satisfying the developer characteristics as described above.

Further, in recent years, there has been an increasing demand for high definition and high image quality of copying machines, and in this technical field, attempts have been made to achieve high image quality by reducing the particle size of toner. If the particle size of the toner particles becomes smaller, the surface area per unit weight increases, and the amount of triboelectricity of the toner tends to increase, and there is a concern that the image density will be low and the durability will deteriorate. In addition, since the triboelectric charge amount of the toner is large, the adhesion between the toner particles is strong and the fluidity is reduced,
Problems tend to occur in stability of toner replenishment and tribo addition to the replenishment toner.

[0017]

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

An object of the present invention is to provide a toner for developing an electrostatic charge image, which is not easily influenced by the environment such as temperature and humidity and has stable triboelectric charging property.

An object of the present invention is to provide a toner for developing an electrostatic charge image, which has clear image characteristics without fog and is excellent in durability stability.

An object of the present invention is to provide an electrostatic charge image developing toner capable of forming a color image or a full color image having excellent transparency on an OHP film.

[0021]

According to the present invention, at least a colorant-containing resin particle and a primary average particle diameter of 1 to 200 are used.
The present invention relates to a toner for developing an electrostatic charge image, which contains amorphous titanium oxide fine particles having mμ.

The present invention will be described in detail below.

The present inventor has examined the triboelectrification stability and fluidity of the toner for developing an electrostatic charge image, and found that a toner using amorphous titanium oxide fine particles having a primary average particle diameter of 1 to 200 mμ is used as an external additive. It has been found that it is extremely effective in stabilizing the triboelectric chargeability in various environments and has good fluidity.

The reason for this is that the conventional titanium oxide production method requires a high temperature sintering step, so that the particles are easily coarsened, and the obtained titanium oxide fine particles have anatase or rutile type crystal structure. These titanium oxide fine particles are likely to be amorphous particles, and it is difficult to obtain fine spherical primary particles.

In the present invention, a preferable toner is
Amorphous titanium oxide fine particles having an average particle diameter of primary particles of 1 to 100 mμ (more preferably 1 to 50 mμ, further preferably 1 to 40 mμ, most preferably 10 to 30 mμ) are used. The average particle diameter (average dispersed particle diameter) of titanium oxide particles (including aggregated titanium particles) such as primary particles, secondary particles, and tertiary particles on the surface of the colorant-containing resin particles is 5 to 150 mμ (more preferably 5). The toner has a bulk density of 0.35 to 0.5 g / cm ³ and an aggregation degree of 2 to 80 mμ).
It is preferably 15% and the weight average particle diameter is 4 to 10 μm.

The toner is stable in charging in various environments, has a good fluidity, and is extremely excellent in fine line fidelity of an original document, reproducibility of highlights and the like, and a high quality image can be obtained. And has arrived at the present invention.

In the present invention, particularly, amorphous titanium fine particles produced by thermally decomposing a volatile titanium compound such as titanium alkoxide in a gas phase at 600 ° C. or lower are preferable. The reason for this is that the conventional titanium oxide production method requires a high temperature sintering step, so that the particles are likely to become coarse, and the resulting titanium oxide fine particles have anatase or rutile type crystal form. Since these titanium oxide fine particles that have undergone the sintering process undergo particle growth during the manufacturing process, they tend to become irregularly shaped particles, making it difficult to obtain spherical and fine primary particles. It has been confirmed that titanium tetrachloride and water are mixed at 200 ° C. to 800 ° C. in two vapor phases to obtain anatase type fine particulate titanium oxide. However, this method yields many amorphous particles. , It is difficult to obtain a spherical one.

The titanium oxide fine particles used in the present invention are
Using a volatile titanium compound as a raw material, the above volatile titanium compound is vaporized or atomized at a relatively low temperature of 600 ° C. or lower (preferably 250 ° C. to 400 ° C.), and then decomposed to form titanium oxide fine particles and decomposed. Immediately thereafter, it is preferable to cool to a temperature (preferably 100 ° C. or lower) at which titanium fine particles do not coalesce again in a shortest possible time.

Further, it is effective to use a dispersion aid, a surface modifier or the like for the purpose of preventing coalescence of the titanium fine particles during cooling or after cooling, or for the purpose of improving collection and recovery.

When the above-mentioned titanium oxide fine particles are externally added to the colorant-containing resin particles, their fine particle diameter and good dispersibility, and the spherical shape effectively act to obtain extremely excellent fluidity. ..

As a factor for stabilizing the charging, the titanium oxide fine powder used in the present invention is charged to the same polarity as the colorant-containing resin particles when rubbed with the iron powder, and the absolute value of the charging amount is 30 μc / g or less. It is preferable that it does not affect the charging characteristics even if the environment changes. When the titanium oxide fine powder having such characteristics is externally added to the colorant-containing resin particles, the triboelectric charge amount of the toner, which tends to become excessive under low humidity, is suppressed. Further, even in a situation where the charge amount is likely to be insufficient such as under high temperature or in the initial stage of rubbing of the toner, the frictional charging of the toner is unlikely to be hindered, and stable charging characteristics can be obtained as a whole.

In order to exert the above-mentioned effect, the average particle size of the primary particles is preferably 1 to 40 mμ (more preferably 10 to 30 mμ), and the aggregate of titanium oxide fine particles on the colorant-containing resin particles is formed. The average dispersed particle diameter of the titanium oxide particle group contained is preferably 5 to 80 mμ (more preferably 10 μm).
Titanium oxide fine particles having a particle size of up to 60 mμ) are added in an amount of 0.01 to 5% by weight (preferably 0.1 to 5% by weight) of the colorant-containing resin particles.
˜3% by weight, more preferably 0.2 to 2% by weight).

If the particle size is larger than the above range or if the added amount is larger than the above range, the dispersion becomes insufficient and the particles are easily released from the colorant-containing resin particles, which not only impairs the effect but also has a harmful effect. It is easy to occur. If the particle size is smaller than the above range or if the added amount is smaller than the above range, the absolute amount is insufficient or the particles are embedded in the colorant-containing resin particles, and the charge controllability and fluidity of the toner tend to be insufficient.

Further, when the titanium oxide fine particles are used in the full-color toner in the present invention, the average particle size on the colorant-containing resin particles is 5 to 150 mμ (preferably 5 to 80 mμ).
Since it is extremely small, the transparency to visible light is very good, color reproduction and color mixing are not hindered, and a projected image of an OHP film having a color image is also very clear.

Conventionally, as an example of adding titanium oxide to a toner, for example, as a polishing agent in JP-A-48-47345, JP-A-52-19535 and JP-A-56-
Although a metal oxide such as titanium oxide is used as a fluidizing agent in the No. 128956 publication, the first object of the present invention is to stabilize the charge in each environment, and is different from these inventions.
Further, as those involved in charging, JP-A-58-18540
No. 5, JP-A-58-216252, the surface-treated titanium oxide fine particles impart positive chargeability to the toner. JP-A-58-1157 and JP-A-60-1
In Japanese Patent No. 36755, when the hydrophobic silica is used as an external additive when used in combination with the hydrophobic silica, the silica is used for the purpose of suppressing the charge amount of the silica, which tends to become excessive.
On the other hand, in the present invention, the charging characteristics of the color toner particles themselves are controlled to reduce the difference in triboelectric charge amount due to temperature or / and humidity fluctuations, and to impart sufficient fluidity to the toner even without silica. Because it is used as a thing,
It is different from these inventions.

As a raw material of titanium oxide used in the present invention, titanium tetramethoxide, titanium tetraethoxide,
Titanium tetrapropoxide, titanium tetrabutoxide,
In addition to titanium alkoxides such as diethoxytitanium oxide, titanium tetrachloride, titanium tetrabromide and other tetrahalogenated titanium, and further trihalogenated monoalkoxytitanium, dihalogenated dialkoxytitanium, monohalogenated trialkoxytitanium, etc. It is also possible to use a titanium compound having properties.

When the volatile titanium compound is vaporized or atomized, it is preferable to dilute the volatile titanium compound with a diluent gas to a ratio of 0.1 to 10% by volume. This diluting gas serves as a carrier gas for introducing the vaporized volatile titanium compound into a decomposition furnace for decomposing.

Here, as the diluting gas, argon gas,
An inert gas such as helium gas or nitrogen gas, water vapor or oxygen is used. Particularly, it is preferable to use helium gas and / or nitrogen gas. Further, if necessary, a dispersion aid, a surface modifier and the like may be added.

In the present invention, since the volatile titanium compound is decomposed after being vaporized or atomized, an oxygen-containing gas is required except that an oxygen-containing compound such as alkoxide is used.

The decomposition temperature is preferably 600 ° C. or lower, more preferably 250 to 400 ° C., and particularly preferably 250 to 350 ° C. At a temperature of less than 250 ° C, it is difficult to obtain a sufficient decomposition rate, while at a temperature of more than 600 ° C, it is difficult to obtain fine titanium oxide particles.

Further, in the present invention, it is preferable that the titanium oxide fine particles thus formed are rapidly cooled to a temperature at which they do not coalesce immediately after decomposition so that they do not coalesce again in the gas phase. The rapid cooling prevents coalescence of the titanium fine particles, and the obtained spherical and fine particulate amorphous titanium oxide can be collected and collected in the state of primary particles.

Surface treatment may be carried out within a range that does not impair the characteristics of the titanium oxide fine powder, such as adjustment of the charging characteristics of the toner and hydrophobic treatment for improving stability under high humidity. When hydrophobizing, 10% to 80% hydrophobicity
(Preferably 40% to 80%, more preferably 50% to
70%) is preferable. If the degree of hydrophobicity is less than 10%, the effect of hydrophobic treatment is not obtained in the fine titanium oxide fine powder, and the electrostatic charge retention is not excellent under high humidity. If it exceeds 80%, particularly in low humidity. Deterioration of charging characteristics and deterioration of fluidity are likely to occur.

As a method of hydrophobizing, when quenching,
For example, it is effective to treat the titanium oxide fine particles after thermal decomposition with a refrigerant of an inert gas such as nitrogen gas by a hydrophobizing agent to make the particles hydrophobic.

To further stabilize the charging of the toner,
The titanium oxide fine particles are charged with the same polarity as the colorant-containing resin particles when they are rubbed with the iron powder, and the absolute value of the charge amount is 30.
It is preferably μc / g or less because it does not affect the charging characteristics of the toner even if the environment changes. When titanium oxide having such characteristics is externally added to the toner, the charge amount of the color toner, which tends to become excessive under low humidity, is suppressed, and the charge amount tends to become insufficient such as at high temperature or in the initial rubbing of the toner. Also, in the case of (1), charging is unlikely to be hindered, and stable charging characteristics can be obtained as a whole.

In the present invention, as another preferable toner, an external additive A comprising titanium oxide fine particles as an external additive is used.
And another external additive B, and when the external additive A and the iron powder are triboelectrically charged, the absolute value is 20 μc / g or less,
When the external additive B and the iron powder are triboelectrically charged, they are charged in the opposite polarity to the colorant-containing resin particles and their absolute value is 10 μc / g.
The average particle diameter of the external additive A is aμ, and the external additive B is
There are some that satisfy the condition of a ≧ b when the average particle diameter of b is bμ.

As a result of diligent studies on the environmental safety of the charging property of the electrostatic charge developing color toner, the present inventors have used at least two or more external additives as the external additives and used iron as the external additive A. The absolute value is 20μ when it is triboelectrically charged with powder.
c / g or less, when the toner is triboelectrically charged with the iron powder as the external additive B, it is charged with the opposite polarity to the toner and its absolute value is 10 μ
It has been found that when it is c / g or more, it is extremely effective in stabilizing the chargeability in various environments.

The reason is that the charge-up due to excessive rubbing of the binder resin is neutralized by the above-mentioned additive having the opposite polarity to the toner.

Further, by adding the additive having the opposite polarity, the rise of the charging of the toner is promoted, and a very stable charging characteristic is achieved from the initial stage.

The reason for this is not clear yet, but it is presumed as follows. At the beginning of charging the toner, the additive B having the opposite polarity is strongly attracted and charged by the charging member rather than the colorant-containing resin particles. Therefore, the rise of charging of the colorant-containing resin particles is promoted. On the other hand, after once rising, it is more strongly attracted to the colorant-containing resin particles than the charge imparting member, and functions to neutralize excessive charge. Therefore, the toner of the present invention has a rise in charge and a saturation charge. The quantity level can be kept good and stable in various environments.

In order to make the above-mentioned action more effective, it is necessary that the average particle size of the additive B having the opposite polarity is smaller than the average particle size of the additive A used in combination. This is because when the additive B having the opposite polarity is large, the colorant-containing resin particles are electrostatically aggregated with each other via the additive having the opposite polarity, and the above-mentioned effect is reduced. Further, the additive B having the opposite polarity needs to be 10 μc / g or more when charged with iron powder. This is a preferable value for neutralizing the colorant-containing resin particles, and if it is less than this value, the neutralizing effect decreases. In particular, in order to make the neutralizing effect even more effective, a temperature of 30
° C. / charge amount when the under and under conditions of temperature 20 ° C. / 10% humidity of 80% humidity was triboelectrification with each iron powder Q _H μc / g, when set to Q _L μc / g Q _L> It is preferably Q _H.

In the present invention, in order to stabilize the performance, the addition amount of the additive B of opposite polarity is related to the addition amount of the additive A, but is 0.1% with respect to the colorant-containing resin particles.
It is preferable that the content is up to 5% by weight.

Further, when the toner has a smaller particle size, the additive B having the opposite polarity is suitable. When the particle size of the toner is reduced, the number of contact points between the toner and the charge-imparting member increases, and the spent of the toner easily occurs, and the contact points of the toner particles and the toner particles increase, and blocking easily occurs. On the other hand, the additive B having a proper polarity and having an opposite polarity serves as good spacer particles and gives good results.

In the present invention, it was confirmed that when silica is used as a fluidity improver together with the neutralization effect, the stable charge is narrowed by silica due to the neutralizing effect described above. In the present invention, it is preferable to use together with the additive A whose absolute value is 20 μc / g or less when triboelectrically charged with iron powder.

As a result, the above-mentioned additive A, which has substantially constant charging characteristics without being affected by temperature and humidity, can impart fluidity without impairing the charging stability of the toner, improve the developing characteristics and transfer the toner. Improved properties are achieved.

It is necessary that the particle size of the additive B is smaller than that of the additive A, and it is preferable to use a fine silica powder which has been surface-treated so as to have suitable charging characteristics. As the silica fine powder before surface treatment of the present invention, either dry process silica or wet process silica can be used,
From the viewpoint of particle size, dry process silica is preferred.

A proposal of using silica and titanium oxide in combination is proposed in, for example, Japanese Patent Publication No. 2-27664.
The present case is different from the present invention in that titanium oxide prevents the phenomenon of charge-up with silica alone. Further, in JP-A-62-229158, there is a proposal as a positively chargeable toner, but the present invention is different in that it is preferably a negatively chargeable toner.

The dry method referred to here is a method for producing fine silica powder produced by vapor phase oxidation of a silicon halogen derivative. For example, in a method utilizing a thermal decomposition oxidation reaction of silicon tetrachloride gas in oxygen hydrogen, the basic reaction formula is as follows. SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

In this manufacturing process, for example, a composite fine powder of silica and another metal oxide can be obtained by using another metal halogen derivative such as aluminum chloride or titanium chloride together with the silicon halogen derivative. These are also included.

On the other hand, as the method for producing the silica fine powder used in the present invention by the wet method, various conventionally known methods can be applied. For example, there is a method in which sodium silicate is prepared by decomposition with an acid. Na ₂ O ・ XSiO ₂ + HCl + H ₂ O → SiO ₂・ nH ₂
O + NaCl

In addition, the method of decomposing sodium silicate with ammonia salts or alkali salts, generating alkaline earth metal silicate from sodium silicate and then decomposing it with acid to obtain silicic acid, and sodium silicate solution as ions There are a method of making silicic acid by an exchange resin, a method of using natural silicic acid or a silicate, and the like.

The silica fine powder mentioned here includes anhydrous silicon dioxide (silica), aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, and the like.
Any silicate such as zinc silicate can be applied.

Examples of the organic group which can serve as the positive triboelectrification site of the silane coupling agent include an amino group and a nitrogen-containing heterocyclic group. As the nitrogen-containing heterocyclic group, there are an unsaturated heterocyclic group and a saturated heterocyclic group, and known ones can be applied to each. Examples of the compound having an unsaturated heterocyclic group include the following.

[0063]

[Outer 1]

Examples of the compound having a saturated heterocyclic group include the following.

[0065]

[Outside 2]

Nitrogen-containing salt compounds such as quaternary ammonium salts and pyridinium salts can also be exemplified. Further, phosphine, phosphonium salt and the like can be exemplified. However, an amino group or a nitrogen-containing heterocyclic group is preferable in consideration of ease of synthesis and cost.

The silane coupling agent can be synthesized by a conventionally known method. Basically, hydrohalogenosilane or hydroalkoxysilane and a compound having an alkene moiety into which the positive triboelectric charging site (and, if necessary, a negative triboelectric charging site) are introduced are allowed to act in the presence of a catalyst such as a platinum-containing compound.

For example, in the case of diethylaminopropyltriethoxysilane, triethoxyhydrosilane and allyldiethylamine are allowed to act in the presence of a chloroplatinic acid catalyst, or chloropropyltriethoxysilane and diethylamine are allowed to act, and then sodium methoxide is further added. It can be obtained by acting and purifying.

The silica fine powder treated with the silane coupling agent as described above improves the environmental stability of the toner, but is further treated with silicone oil in order to further improve the moisture resistance, fluidity and transferability. Is also good. By the silicone oil treatment, the slipperiness of the fine silica powder is improved, the fluidity of the toner is increased, and the transferability from the photosensitive drum can be further improved.

The degree of hydrophobicity of the silica fine powder is preferably 90% or more (preferably 95% or more). If the degree of hydrophobicity is less than this, it becomes difficult to obtain a high-quality image due to the water adsorption of the silica fine powder under high humidity.

The amount of the additive A used in the present invention is
The amount is 0.01 to 5% by weight, preferably 0.05 to 2% by weight, based on the weight of the colorant-containing resin particles. Although this addition amount is related to the amount of the additive B used, if it is less than 0.01% by weight, it is difficult to achieve appropriate fluidity, and if it exceeds 5% by weight, problems such as toner scattering and deterioration of fog occur. Cheap. Further, it is preferable that the amount of the additive B used is smaller than the amount of the additive A used for stabilization. It is the reverse polarity resin fine particles that can neutralize the excessive charge of the color toner that is effective in stabilizing the charge of the toner. In order to exert such an effect, it is preferable that the particle size of the resin fine particles is 20 to 200 mμ and the addition amount is in the range of 0.1 to 5.0% by weight with respect to the color toner.

The monomer constituting the reverse polarity resin particles to be combined with the present invention as necessary is not particularly limited, but it is necessary to select it in consideration of the charge amount of the toner. The following monomers may be mentioned as specific examples of the addition-polymerizable monomer that can be used in the present invention.

Styrene and its derivatives, such as styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, alkylstyrenes such as heptylstyrene, octylstyrene, fluorostyrene. , Halogenated styrenes such as chlorostyrene, bromostyrene, dibromostyrene and iodostyrene, and further nitrostyrene, acetylstyrene, methoxystyrene and the like.

Addition-polymerizable unsaturated carboxylic acids, that is, acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, α-methylcrotonic acid, α-ethylcrotonic acid,
Addition-polymerizable unsaturated aliphatic monocarboxylic acids such as isocrotonic acid, tiglic acid and ungeric acid, or addition-polymerizable unsaturated fats such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, dihydromuconic acid Group dicarboxylic acids.

The metal chlorides of these carboxylic acids can also be used, and this metal chloride can be carried out after completion of the polymerization.

The addition-polymerizable unsaturated carboxylic acid and alkyl alcohol, halogenated alkyl alcohol,
Examples thereof include esterification products with alcohols such as alkoxyalkyl alcohol, aralkyl alcohol, and alkenyl alcohol. Then, as specific examples of the alcohol, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol,
Alkyl alcohols such as hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol; halogenated alkyl alcohols obtained by partially halogenating these alkyl alcohols; methoxyethyl alcohol, ethoxyethyl alcohol, ethoxy Alkoxyalkyl alcohols such as ethoxyethyl alcohol, methoxypropyl alcohol and ethoxypropyl alcohol; aralkyl alcohols such as benzyl alcohol, phenylethyl alcohol and phenylpropyl alcohol; alkenyl alcohols such as allyl alcohol and crotonyl alcohol.

Further, amides and nitriles derived from the addition-polymerizable unsaturated carboxylic acid; aliphatic monoolefins such as ethylene, propylene, butene and isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, 1,2.
-Dichloroethylene, 1,2-dibromoethylene, 1,
Halogenated aliphatic olefins such as 2-diiodoethylene, isopropenyl chloride, isopropenyl bromide, allyl chloride, allyl bromide, vinylidene chloride, vinyl fluoride, vinylidene fluoride; 1,3-butadiene, 1,3- Pentadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 3
And conjugated diene-based aliphatic diolefins such as -methyl-2,4-hexadiene.

Further, vinyl acetates, vinyl ethers; nitrogen-containing vinyl compounds such as vinylcarbazole, vinylpyridine, vinylpyrrolidone and the like can be mentioned.

As the fine powder, those obtained by polymerizing one kind or two or more kinds of these monomers can be used.

The reverse polarity resin particles are not limited to using only one type, and a plurality of types can be used in combination.

As the method for producing the reverse polarity resin particles used in the present invention, spherical fine particles can be produced by a spray drying method, a suspension polymerization method, an emulsion polymerization method, a soap-free polymerization method, a seed polymerization method, a mechanical grinding method, or the like. Any method can be used. Among these, particularly suitable is a soap-free polymerization method which does not hinder the charging property of the toner and has little environmental fluctuation of the specific electric resistance because there is no residual emulsifier, but the method is not particularly limited. ..

The reverse polarity resin particles may be subjected to particle surface treatment, if necessary. As the method of surface treatment, a method of surface-treating a metal such as iron, nickel, cobalt, copper, zinc, gold or silver by a vapor deposition method or plating, or a metal oxide such as the above metal, magnetic material or conductive zinc oxide is used. Method of fixing things such as ion adsorption or external addition, pigment or dye,
Further, a triboelectrically chargeable organic compound such as a polymer resin may be supported by coating or external addition.

The molecular weight distribution of the reverse polarity resin particles is required to have a peak molecular weight in the range of 10,000 to 5,000,000, and preferably in the range of 20,000 to 1,000,000. When the peak molecular weight is larger than 5,000,000, the fixability of the color toner is adversely affected, and when it is smaller than 10,000, the magnetic particles are contaminated or the blocking resistance is deteriorated.

In the present invention, by using the above-mentioned titanium fine particles, even in the case of a toner having a weight average particle diameter of 4 to 10 μ, the cohesion degree and the bulk density in the above ranges can be satisfactorily satisfied.

The average particle diameter of the colorant-containing resin particles is 4 to 10
When the value is made as small as μ, the degree of aggregation of the toner is increased, the bulk density is increased, and the toner transportability from the toner hopper to the toner container in the developing device is lowered, or the problem of charging failure is likely to occur.

For the purpose of reducing the cohesion of the toner, for example, B
Although it is general to add colloidal silica fine particles having a large ET surface area, addition of colloidal silica fine particles is liable to deteriorate the environmental stability inevitably and to reduce the triboelectric charge amount of the toner under high humidity. However, the triboelectric charge amount of the toner increases under low humidity, which makes it difficult to achieve an appropriate image density.

Among the conventional titanium fine particles, some have a small primary particle diameter of about 20 mμ. However, these titanium fine particles have many aggregated particles or aggregates of the primary particles due to the production method thereof, and the toner targeted by the present invention is the toner. It was difficult to satisfy the cohesion degree and the bulk density.

The colorant-containing resin particles according to the present invention may be blended with a charge control agent in order to stabilize the charge characteristics. At that time, a colorless or light-colored charge control agent that does not affect the color tone of the colorant-containing resin particles is preferable. Examples of the negative charge control agent include organic metal complexes such as metal complexes of alkyl-substituted salicylic acid (for example, chromium complex or zinc complex of di-tert-butylsalicylic acid). When the negative charge control agent is blended with the colorant-containing resin particles, 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, is added to 100 parts by weight of the binder resin.

When a two-component type developer is prepared by mixing the toner of the present invention and a carrier, the mixing ratio thereof is 2 to 12% by weight, preferably 3 to 9% by weight in the developer. Usually good results are obtained. If the toner concentration is less than 2% by weight, the image density tends to be low, and if it exceeds 12% by weight, fog and scattering in the machine are increased and the useful life of the developer is apt to be shortened.

Examples of the colorant used in the present invention include dyes and pigments known as non-magnetic toner, for example, phthalocyanine blue, indanthrene blue, peacock blue, permanent red, lake red, rhodamine lake, hansa yellow, permanent yellow, Benzidine yellow or the like can be used. As for its content,
In order to sensitively reflect the transparency of the OHP film, the amount is 12 parts by weight or less, preferably 0.5 to 9 parts by weight, based on 100 parts by weight of the binder resin. A magnetic toner can be used by using a magnetic material.

If necessary, the toner of the present invention may be mixed with additives within a range that does not impair the characteristics of the toner. Examples of such additives include organic resin particles, charging aids such as metal oxides, lubricants such as Teflon, zinc stearate and polyvinylidene fluoride, or fixing aids (eg low molecular weight polyethylene, low molecular weight polypropylene). Etc.).

In the production of the colorant-containing resin particles and the toner of the present invention, the constituent materials are well kneaded by a heat kneader such as a hot roll, a kneader or an extruder, and then mechanically pulverized to classify the pulverized powder. To obtain a toner by dispersing a material such as a colorant in a binder resin solution,
Method obtained by spray-drying; a predetermined material is mixed with a polymerizable monomer that constitutes the binder resin to obtain a monomer composition, and an emulsion suspension of this composition is polymerized to obtain a toner. The obtained toner production method by suspension polymerization can be applied.

As the binding substance used for the colorant-containing resin particles, various material resins conventionally known as electrophotographic toner binding resins are used.

For example, polystyrene; styrene / styrene copolymers such as styrene / butadiene copolymers, styrene / acrylic copolymers, styrene / methacrylic copolymers; polyethylene polymers; ethylene / vinyl acetate copolymers, ethylene / vinyl. Ethylene copolymers such as alcohol copolymers; phenolic resins; epoxy resins; acrylic phthalate resins; polyamide resins; polyester resins;
Examples include maleic acid resins. The manufacturing method of any resin is not particularly limited.

Among these resins, the effect of the present invention is remarkable when a polyester resin having a high negative chargeability is used. The polyester resin has excellent fixability and is suitable as a binder resin for color toners, but on the other hand, it has a strong negative charging ability, and the triboelectric charge amount of the toner tends to become excessive. When a resin is used, the harmful effect is improved and an excellent toner is obtained.

In particular, the following equation

[0097]

[Outside 3] (In the formula, R and R ′ are ethylene or propylene groups, x and y are each an integer of 1 or more, and x + y
The average value of is from 2 to 10. ), A bisphenol derivative or a bisphenol-substituted compound represented by the formula (1) is used as a diol component, and a carboxylic acid component composed of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof (eg, fumaric acid, maleic acid, maleic anhydride, A polyester resin obtained by copolycondensation of phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) is preferable because it has sharp melting characteristics.

When the toner of the present invention and a carrier are mixed and used as a two-component developer, it is preferable to use an electrically insulating resin as a coating resin for the surface of the carrier, and a toner material or / and a carrier core material. It is appropriately selected depending on the material. In the present invention, in order to improve the adhesiveness to the surface of the carrier core material, as the coating resin, at least one selected from at least acrylic acid (or its ester) monomer and methacrylic acid (or its ester) monomer. It is preferable to use a resin containing the above monomer. In particular, when the colorant-containing resin particles using a polyester resin having a high negative chargeability are used as the toner material, the coating resin may be a copolymer with a styrene-based monomer for the purpose of stabilizing the charge. preferable. The copolymerization weight ratio of the styrene-based monomer is preferably 5 to 70% by weight.

Examples of the monomer for the resin for coating the carrier core material which can be used in the present invention include styrene monomers, styrene monomers, chlorostyrene monomers, α-methylstyrene monomers, styrene-chlorostyrene monomers and the like; as acrylic monomers. There are acrylic acid ester monomers (methyl acrylate monomer, ethyl acrylate monomer, butyl acrylate monomer, octyl acrylate monomer, phenyl acrylate monomer, 2-ethylhexyl acrylate monomer); methacrylic acid ester monomer (methacrylic acid monomer There are methyl monomers, ethyl methacrylate monomers, butyl methacrylate monomers, phenyl methacrylate monomers).

The carrier core material (magnetic particles) used in the present invention includes, for example, surface-oxidized or unoxidized metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium and rare earths, and alloys or ferrites thereof. Oxides such as can be used. There are no particular restrictions on the manufacturing method.

Next, an example of a developing device for developing a non-magnetic one-component toner using the toner of the present invention will be described.
It is not necessarily limited to this. FIG. 1 shows an apparatus for developing an electrostatic image formed on a latent image carrier. In the latent image carrier 1, latent images are formed by electrophotographic process means or electrostatic recording means (not shown). The developer carrying member 2 is composed of a non-magnetic sleeve made of aluminum, stainless steel or the like. The non-magnetic one-component color toner is stored in the hopper 3 and is supplied onto the developer carrier 2 by the supply roller 4. The supply roller 4 also removes the toner on the developer carrying member 2 after development. The toner supplied onto the developer carrying member 2 is uniformly and thinly applied by the developer applying blade 5. The contact pressure between the developer coating blade 5 and the developer carrying member 2 is effectively 3 to 250 g / cm, preferably 10 to 120 g / cm as the linear pressure in the sleeve generatrix direction. When the contact pressure is less than 3 g / cm, it becomes difficult to apply the toner uniformly, and the charge amount distribution of the toner becomes broad, which easily causes fog and scattering. If the contact pressure exceeds 250 g / cm, a large pressure is applied to the toner, so that the toner particles tend to agglomerate or are crushed, which is not preferable. By adjusting the contact pressure to 3 to 250 g / cm, it becomes possible to satisfactorily loosen the agglomeration of the small particle size toner,
It is possible to instantly increase the triboelectric charge amount of the toner. The developer coating blade 5 is preferably made of a triboelectric material suitable for charging the toner to a desired polarity.

In the present invention, silicone rubber, urethane rubber, styrene-butadiene rubber and the like are preferable.
The use of a conductive rubber is preferable because it can prevent the toner from being triboelectrically charged excessively. If necessary, the surface of the blade 5 may be coated. Particularly when used as a negative toner, it is preferable to coat a positively chargeable resin such as a polyamide resin.

In a system in which a thin layer of toner is coated on the developer carrying member 2 with the blade 5, the thickness of the toner layer on the developer carrying member 2 is set to obtain a sufficient image density. It is preferable that the length is smaller than the opposing gap length between the latent image carrier 1 and the latent image carrier 1 and an alternating electric field is applied to this gap. By the bias power source 6 shown in FIG.
An alternating electric field or a developing bias in which a direct current electric field is superposed on the alternating electric field is applied between the latent image holding member 1 and the latent image holding member 1 to facilitate the movement of the toner on the latent image holding member 1 from the developer holding member 2, and further improve the quality. The image of can be obtained.

The methods for measuring each physical property in the present invention will be described below.

(1) Measurement of triboelectric charge amount: The measuring method will be described in detail with reference to FIG.

FIG. 2 is an explanatory view of an apparatus for measuring the triboelectric charge amount of toner. First, in a metal measuring container 22 having a 500 mesh screen 23 on the bottom, a mixture of colorant-containing resin particles or toner and iron powder having a weight ratio of 1:19, whose amount of triboelectric charge is to be measured, is about 0.5-1. .5g (also
In the case of an external additive, a mixture of 1:99) is 50-100
Place in a polyethylene bottle with a volume of about 10-40
Shake by hand for a second and cover with metal lid 24. At this time, the total weight of the measurement container 22 is weighed and set as W ₁ (g). Next, in the suction device 21 (at least the portion in contact with the measurement container 22 is an insulator), suction is performed from the suction port 27, and the air volume control valve 26 is adjusted to set the pressure of the vacuum gauge 25 to 250 mmAq. In this state, sufficient suction (preferably 2 minutes) is performed to remove the toner by suction. The potential of the electrometer 29 at this time is V (volt). Here, 28 is a capacitor, and the capacitance is C (μF). The weight of the entire measuring container after suction is weighed and is W ₂ (g). The triboelectric charge amount (μc / g) of this toner is calculated by the following formula.

[0107]

[Outside 4] (However, the measurement conditions are 23 ° C. and 60% RH.)

(2) Toner particle size measurement: The particle size distribution can be measured by various methods, but in the present invention, it was measured using a Coulter counter.

As a measuring device, a Coulter counter T
A-II type (manufactured by Coulter, Inc.)
An interface (made by Nikkaki) that outputs volume distribution and a CX-1 personal computer (made by Canon) are connected, and the electrolyte is 1% NaC using first-grade sodium chloride.
l Prepare an aqueous solution. As a measuring method, the electrolytic solution 1
0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) as a dispersant in 0 to 150 ml
In addition, 2 to 20 mg of the measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the Coulter Counter TA-II type is used to form a 100 μm aperture as an aperture, and the volume of the colorant-containing resin particles or toner particles Then, the number is measured to calculate a volume distribution and a number distribution of 2 to 40 μm. Then, according to the present invention, the weight-based weight average diameter (D4) obtained from the volume distribution (the median value of each channel is a representative value for each channel), and the weight-based coarse powder amount obtained from the volume distribution ( 16.0 μm or more), and the number-based fine powder number (5.04 μm or less) obtained from the number distribution is obtained.

(3) Aggregation degree measurement: The aggregation degree is used as one means for measuring the flow characteristics of the toner having the sample or the external additive. The larger the value of the degree of aggregation, the worse the fluidity of the sample.

A powder tester (manufactured by Hosokawa Micron Co., Ltd.) is used as a measuring device.

As a measuring method, 200 mesh, 100 mesh, and 60 mesh screens were placed on the vibrating table in the order of narrow openings, that is, in order of 200 mesh, 100 mesh, and 60 mesh screens so that the 60 mesh screen was at the top. Set on top of each other.

5 g of an accurately weighed sample was added to the set 60 mesh sieve, and the input voltage to the shaking table was set to 2
The amplitude of the vibrating table at that time is set to 1.7 V and is 60
Adjust to fall within the range of ˜90 μ (Rheostat scale about 2.5) and apply vibration for about 15 seconds. Then, the weight of the sample remaining on each sieve is measured to obtain the aggregation degree according to the following formula.

[0114]

[Outside 5]

The sample is about 1 at 23 ° C. and 60% RH.
The one left for 2 hours is used, the measurement environment is 23 ° C, 60%
RH.

(4) Bulk (apparent) density measurement: The apparent density is measured using a powder tester (manufactured by Hosokawa Micron). For measurement, a 60-mesh sieve is set on a vibrating table, and an apparent density measuring cup (internal capacity: 100 cc) whose weight is measured in advance is placed directly under the 60-mesh sieve.

Next, the rheostat scale is adjusted to 2.0 and vibration is started. The sample to be measured is gently discharged from the vibrating upper part of the 60 mesh screen so as to enter the measuring cup.

When the cup is filled with the heaped sample, the vibration is stopped, the upper surface of the heaped cup is scraped with a blade, and the balance is accurately weighed.

Since the measuring cup has an internal capacity of 100 cc, the apparent density (g / cm ³ ) = sample weight ÷ 1
00 can be obtained.

The sample was about 1 at 23 ° C. and 60% RH.
The one left for 2 hours is used, the measurement environment is 23 ° C, 60%
RH.

(5) Hydrophobicity measurement The methanol titration test is an experimental test for confirming the hydrophobicity of inorganic fine particles having a hydrophobized surface.

0.2 g of the inorganic fine particles to be tested (for example, titanium oxide fine powder) was mixed with 5 parts of water in a 250 ml Erlenmeyer flask.
Add to 0 ml. Methanol is titrated from the burette until the total amount of inorganic particulate is wet. At this time, the solution in the flask is constantly stirred with a magnetic stirrer.
The end point is observed by suspending the total amount of the inorganic fine particles in the liquid, and the hydrophobicity is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

[0123]

EXAMPLES The present invention will be described in detail below with reference to production examples of titanium oxide fine particles and examples and comparative examples of the present invention. Parts and percentages are by weight.

Titanium Oxide Fine Particles Production Example 1 (Invention) Titanium tetraisopropoxide was used as a raw material. Using nitrogen gas as a carrier gas, the raw materials are sent to the glass wool of a vaporizer heated to 200 ° C and vaporized by a chemical pump. Hexamethyldisilazane gas is used as a carrier gas, and hydrophobic treatment is performed at the same time, and rapid cooling is performed to collect the product. The triboelectric charge amount is -20 μc / g, the average primary particle diameter is 20 mμ, and the BET specific surface area is 130 m ² / g. Spherical titanium oxide fine particles I having a hydrophobicity of 70% and a carbon content of 7% were obtained. It was confirmed by X-ray diffraction that the titanium oxide fine particles were amorphous.

Fine Titanium Oxide Fine Particles Production Example 2 (Invention) The same procedure as in Production Example 1 was repeated except that methyltriethoxysilane was used instead of hexamethyldisilazane, and the triboelectric charge was -17 μc / g and the average primary particle diameter was 20 mμ. , BET
Amorphous spherical titanium oxide fine particles I having a specific surface area of 120 m ² / g, a hydrophobicity of 65% and a carbon content of 6%
Got I.

Titanium Oxide Fine Particles Production Example 3 (Invention) Titanium tetranormal propoxide was used instead of titanium tetraisopropoxide, the vaporizer humidity was 220 ° C., and the reactor temperature was 270 ° C. As in Example 1, amorphous spherical titanium oxide fine particles having a triboelectric charge amount of -19 μc / g, an average primary particle diameter of 32 mμ, a BET specific surface area of 100 m ² / g, a hydrophobicity of 70%, and a carbon content of 5.5%. III was obtained.

Production Example 4 of Titanium Oxide Fine Particles (Invention) The same procedure as in Example 1 was carried out except that hexamethyldisilazane was not used, and the triboelectrification amount was 0 μc / g and the average primary particle size was 2
Amorphous spherical titanium oxide fine particles IV having a 0 mμBET specific surface area of 150 m ² / g, a hydrophobicity of 0 and a carbon content of 0.2% were obtained.

Titanium oxide fine particles Production Example 5 (Comparative Example) Titanium oxide fine particles were produced in the same manner as in Production Example 1 except that the thermal decomposition temperature was 800 ° C., and the triboelectric charge amount was −33 μc / g and the average primary particle diameter was 20.
mμ, BET specific surface area 75 m ² / g, hydrophobicity 80%,
Amorphous spherical titanium oxide fine particles V having a carbon content of 4.5% were obtained.

Production Example 6 of Titanium Oxide Fine Particles (Comparative Example) The same procedure as in Production Example 1 was carried out except that rapid cooling was not carried out after thermal decomposition. The triboelectric charge amount was -24 μc / g and the average primary particle diameter was 25.
mμ, BET specific surface area 120 m ² / g, hydrophobicity 70
%, Carbon content 6.5%, amorphous spherical titanium oxide VI was obtained.

Production Example 7 of Titanium Oxide Fine Particles (Comparative Example) Titanium tetrachloride was thermally decomposed in a gas phase at 800 ° C. to give a triboelectric charge amount of 0 μc / g, an average primary particle diameter of 25 mμ, a BET specific surface area of 80 m ² / g, Amorphous spherical titanium oxide / VII having a hydrophobicity of 0 was obtained.

Production Example 8 of Titanium Oxide Fine Particles (Comparative Example) Spherical titanium oxide VII was subjected to a hydrophobic treatment with hexamethyldisilazane in the gas phase to give a triboelectric charge amount of 12 μc / g, an average primary particle diameter of 25 mμ and a BET specific surface area of 70 m. Spherical titanium oxide VIII having ² / g, a hydrophobicity of 50% and a carbon content of 3.8% was obtained.

Production Example 9 of Titanium Oxide Fine Particles (Comparative Example) A titanium oxide was produced by the sulfuric acid method in which the precipitate formed was neutralized in an aqueous solution of titanium sulfate, and the triboelectric charge was -2.5 μc /
g, average primary particle size 200 mμ, BET specific surface area 50 m
² / g of rutile type titanium oxide IX was obtained.

Example 1 Polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 100 parts Phthalocyanine pigment 4 parts Di-tert-butylsalicylic acid chromium complex salt 4 parts

The above materials were sufficiently premixed by a Henschel mixer, melt-kneaded by a twin-screw extruder, cooled, roughly crushed to about 1 to 2 mm by a hammer mill, and then finely crushed by an air jet method. Finely crushed with.
Further, the finely pulverized product obtained is classified to have a weight average particle diameter of about 8 μm.
Colorant-containing resin particles (amount of triboelectric charge-20.5 μc /
g) was obtained.

The colorant-containing resin particles and 0.5% by weight of the titanium oxide fine particles I of Production Example 1 were mixed with a Henschel mixer to obtain a cyan toner. This cyan toner is
The weight average diameter was 7.9μ. The average particle diameter of the titanium oxide fine particles on the colorant-containing resin particles was 36 mμ.

Weight average particle diameter 45μ (4.2 is less than 35μ)
Wt%, 35-40 μ is 9.5 wt%, 74 μ or more is 0.2% in particle size distribution), and a Cu-Zn-Fe-based ferrite carrier has 80% by weight of styrene and 20% by weight of methyl methacrylate. Combined (number average molecular weight 35,000 weight average molecular weight 76,000),
A developer was prepared by mixing 95 parts of a coated ferrite carrier coated with 5% and 5 parts of a cyan toner.

Using this developer, a commercially available plain paper color copying machine (color laser copier 500, manufactured by Canon) was used to set the development contrast to 300 V, and the temperature was 23 ° C./65.
The image was drawn out under%. The image obtained is Macbeth RD9
Reflection density measurement was performed using an 18-inch SPI filter (the same applies to subsequent image density measurement methods). The toner image density was as high as 1.49 and it was clear without fog. After that, 10,000 more copies were made, and the density fluctuation during that period was as small as 0.09, and fog and sharpness similar to those at the initial stage were obtained. Low temperature and low humidity (20 ℃, 1
Even when the development contrast was set to 300 V at 0% RH and image formation was performed, the image density was as high as 1.45, which was effective in controlling the charge amount under low humidity.

When a cyan toner image was transferred onto an OHP film and fixed, it was transmitted through an overhead projector, and a clear cyan image was projected on the screen.

Even under high temperature and high humidity (30 ° C./80%), similarly, when the development contrast was set to 300 V and image formation was performed, the image density was 1.52, and a very stable and good image was obtained. It was

23 ° C./60% RH, 20 ° C./10
%, 30 ° C./80%, the initial image after being left for 1 month in each environment showed no abnormality.

Table 1 shows the physical properties of toner, and Table 2 shows the amount of charge and the image characteristics in each environment (same below). Except that the titanium oxide fine particles II and III of Examples 2 and 3 are used.
When a toner and a developer were prepared in the same manner as in Example 1 and tested in the same manner as in Example 1, good results were obtained.

Example 4 A toner and a developer were prepared in the same manner as in Example 1 except that the titanium oxide fine particles IV were used and tested in a high temperature and high humidity environment (30 ° C./80%). The image density was higher than in Example 1 and lacked in stability, but there was no problem in practical use.

Comparative Example 1 A toner and a developer were prepared in the same manner as in Example 1 except that the titanium oxide fine particles V were used. The average dispersed particle diameter on the colorant-containing resin particles was as large as 100 mμ.
The toner cohesion was as large as 19%, and the image quality was deteriorated in the image output test.

Comparative Example 2 The procedure of Comparative Example 1 was repeated except that the titanium oxide fine particles V were used in an amount of 1.5%. As a result, the toner cohesion decreased to 5.2%, but the toner charge amount was low. , Toner scattering has occurred.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the titanium oxide fine particles VI were used, and as a result, the average particle diameter on the colorant-containing resin particles was as large as 90 mμ, and the image quality was deteriorated.

Comparative Example 4 Instead of the titanium oxide fine particles I, fine silica powder treated with dimethyldichlorosilane (average primary particle diameter 10 mμ, B
The same procedure as in Example 1 was carried out except that ET220 m ² / g hydrophobicity 70%) was used, and at 20 ° C./10%, the charge was high and the image density was low.

Comparative Examples 5 and 6 Titanium oxide VII to IX were used, except that the image quality was deteriorated.

Example 5 Same as Example 1 except that the developing device of a commercially available color copying machine (color laser copier 500, made by Canon) is modified as shown in FIG. 1 and only toner is used without using a carrier. When the image was printed with, good results were obtained. At this time, as the toner coating blade, a urethane elastic blade coated with a polyamide resin was used.

[0149]

[Table 1]

[0150]

[Table 2]

Example 6 100 parts by weight of polyester resin obtained by condensing propoxylated bisphenol and fumaric acid C.I. I. Pigment Yellow 17 3.5 parts by weight • Chromium complex salt of zeta-tert-butylsalicylic acid 4
Parts by weight

Using the above materials, in the same manner as in Example 1, colorant-containing resin particles having a weight average particle size of about 8 μm (amount of triboelectrification charge-22.7 μc / g) were obtained. A yellow toner was prepared by mixing 99.5 parts by weight of the obtained colorant-containing resin particles and 0.5 parts by weight of titanium oxide fine particles I. The yellow toner has a weight average particle diameter of 7.9 μm, an average dispersion diameter of titanium oxide fine particles on the colorant-containing resin particles is 37 mμ, and a coagulation degree of the yellow toner is 3.3%. The bulk density was 0.43 g / cm ³ .

Then, in the same manner as in Example 1, 5 parts by weight of the yellow toner and 95 parts by weight of the coated ferrite carrier were mixed to obtain a two-component type developer, and the image was formed in the same manner as in Example 1. As a result, a good yellow toner image was obtained.

When a yellow toner image was transferred onto an OHP film and fixed, it was transmitted through an overhead projector, and a clear yellow image was projected on the screen.

Example 7 Polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 100 parts by weight Rhodamine pigment 4 parts by weight Chromium complex salt of diethyl butyl salicylic acid 4
Parts by weight

Using the above materials, in the same manner as in Example 1, colorant-containing resin particles having a weight average particle diameter of about 8 μm (friction charge amount: −21.3 μc / g) were obtained. 99.5 parts by weight of the obtained colorant-containing resin particles and 0.5 of titanium oxide fine particles I
Magenta toner was prepared by mixing with a part by weight. The magenta toner has a weight average particle diameter of 7.9 μm, and the average dispersion diameter of the titanium oxide fine particles on the colorant-containing resin particles is 35.
mμ, the degree of aggregation of the yellow toner was 3.1%, and the bulk density of the yellow toner was 0.42 g / cm ³ .

Then, in the same manner as in Example 1, 5 parts by weight of the magenta toner and 95 parts by weight of the coated ferrite carrier were mixed to obtain a two-component developer, and an image was formed in the same manner as in Example 1. As a result, a good magenta toner image was obtained.

When a magenta toner image was transferred onto an OHP film and fixed, it was transmitted through an overhead projector, and a clear magenta image was projected on the screen.

Example 8 Cyan toner-containing two-component developer prepared in Example 1,
Using the yellow toner-containing two-component developer prepared in Example 6 and the magenta toner-containing two-component developer prepared in Example 7, a plain paper color copying machine (color laser copier 500) was used to obtain a full-color image. When an image output test was conducted, a good full-color image was obtained, and the color mixing state of each color was good.

When an OHP film having a full-color image formed by transferring and fixing a multicolor toner image on the OHP film was transmitted through an overhead projector, a clear full-color image was projected on the screen.

According to the present invention, the fine particles of titanium oxide as an external additive are improved, particularly those obtained by subjecting a volatile titanium compound at a relatively low temperature to rapid cooling and hydrophobizing treatment after vapor phase thermal decomposition reaction. By using the toner,
It can stabilize the charge in various environments and exhibits good fluidity.

Titanium Oxide Fine Particle Production Example 10 Titanium tetraisopropoxide is used as a raw material. A small amount of the raw material was fed by a chemical pump into glass wool of vaporizer Izano heated to 200 ° C. to evaporate, introduced into a reactor and a subsequent cooling pipe, and thermally decomposed at 350 ° C., and the product adhered to the cooling pipe. Then, the product adhering to the cooling pipe was captured to obtain titanium oxide fine particles. At this time, helium was used as a carrier gas for introducing the raw material, and titanium oxide fine particles were previously attached to the inner wall of the reactor.

The obtained titanium oxide fine particles were observed with a transmission electron microscope, and the particle diameter of 100 particles in the visual field was measured to obtain the average particle diameter, which was 25 mμ. It was also confirmed by analysis by X-ray diffraction that it was amorphous.
The triboelectric charge amount of the titanium oxide fine particles was 0 μc / g.

Titanium Oxide Fine Particle Production Example 11 Titanium tetranormal propoxide was used as a raw material, the vaporizer temperature was 220 ° C., and the reactor temperature was 280.
Titanium oxide fine particles were obtained in the same manner as in Production Example 10 except that the temperature was changed to ° C.

The obtained titanium oxide fine particles were observed with a transmission electron microscope, and the average particle diameter was determined in the same manner as in Production Example 10 to find that it was 35 mμ, and it was confirmed by X-ray diffraction analysis that it was amorphous. The triboelectric charge amount of the titanium oxide fine particles was 0 μc / g.

Example 9 Polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 100 parts Phthalocyanine pigment 4 parts Di-tert-butylsalicylic acid chromium complex salt 4 parts

The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded with a three-roll mill twice or more, cooled, coarsely pulverized to about 1 to 2 mm with a hammer mill, and then finely pulverized by an air jet method. Pulverized with a machine. Further, the obtained fine powder was classified to obtain colorant-containing resin particles (amount of triboelectric charge of −22.4 μc / g).

Cyan toner was obtained by mixing 0.7% of titanium oxide fine particles of Production Example 10 and 0.3% of acrylic reverse polarity resin particles having a particle diameter of 50 mμ with the colorant-containing resin particles using a Henschel mixer. This cyan toner had a weight average diameter of 7.9 μ.

Weight average particle diameter 45μ (4.2 is less than 35μ)
%, 35-40 μ has a particle size distribution of 9.5% by weight, and 74 μ or more has a particle size distribution of 0.2% by weight.) A Cu—Zn—Fe ferrite carrier, a styrene component 50%, a methylmethacrylate component 20%, 2- Copolymer consisting of 30% of ethylhexyl acrylate component (number average molecular weight 212
50 parts of a carrier coated with 0.5% of 50 and a weight average molecular weight of 52360) and 5 parts of a cyan toner were mixed to prepare a developer.

Using this developer, the development contrast was set to 300 V in a commercially available plain paper color copying machine (color laser copier 500, made by Canon), and 23 ° C./65%.
Pictured below. The image obtained is Macbeth RD91
The reflection density was measured using an SPI filter of 8 type (the same applies to the subsequent image density measuring method). The image density was as high as 1.49 and was clear without fog. After that, 10,000 more copies were made, but the density fluctuation during that time was as small as 0.09, and fog and sharpness similar to those at the initial stage were obtained. Low temperature and low humidity (20 ° C, 10% RH)
Also, when the development contrast was set to 300 V and image formation was performed, the image density was as high as 1.45, which was effective in controlling the charge amount under low humidity.

Even under high temperature and high humidity (30 ° C./80%), when the development contrast was set to 300 V and image formation was performed, the image density was 1.56, and a very stable and good image was obtained. It was

23 ° C./60% RH, 20 ° C./10
%, 30 ° C./80%, the initial image after being left in each environment for 1 month did not show any abnormality.

Example 10 Image formation was carried out in the same manner as in Example 9 except that the titanium oxide fine particles of Production Example 11 were used as the external additive. Image density is 1.44 to 1.53 at 20 ° C / 10%; 23 ° C /
1.47 to 1.55 under 65% and 1.50 to 1.57 at 30 ° C./80%, and good results were obtained.

Example 11 An image was produced in the same manner as in Example 9 except that the developing device of a commercially available color copying machine (color laser copier 500, manufactured by Canon) was modified as shown in FIG. 1 and no carrier was used. went. Image density is 1.46 to 1.5 at 20 ° C / 10%
3; 23 ° C./1.50 to 1.58 under 65%; 30 ° C. /
It was 1.56 to 1.60 under 80%, and good results were obtained.

Example 12 Except that titanium oxide fine particles (triboelectric charge amount-18.7 μc / g) having a hydrophobicity of 22% obtained by subjecting titanium oxide of Production Example 10 to a hydrophobic treatment with a titanium-based coupling agent were used as external additives. Image formation was performed in the same manner as in Example 9. Image density is 2
1.40 to 1.46 under 0 ° C / 10%; 23 ° C / 65%
1.41 to 1.47 under; 1.50 under 30 ° C / 80%
It was ~ 1.57, and good results were obtained without impairing the characteristics under low humidity.

Example 13 Image formation was carried out in the same manner as in Example 9 except that reverse polarity resin particles having a particle size of 50 mμ (friction charge amount +60 μc / g) were not used as an external additive. The image density is 1.37 to 1.42 at 20 ° C./10%; 1.42 at 23 ° C./65%.
1.53; 1.50 to 1.58 at 30 ° C./80%, and although the image density under low humidity was slightly reduced as compared with Example 9, good results were obtained.

Comparative Example 8 As an external additive, titanium sulfate instead of the titanium oxide fine particles of Production Example 10 was neutralized in an aqueous solution, and the resulting precipitate was calcined. Image formation was performed in the same manner as in Example 9 except that titanium fine particles (triboelectric charge amount 0 μc / g) were used. 30 ° C / 8
Under 0%, the image density was increased from the 500th sheet due to a shortage of the charge amount, and the toner was scattered from around 3000 sheets.

Comparative Example 9 Silica fine powder treated with dimethyldichlorosilane instead of the titanium oxide fine particles of Production Example 10 as an external additive (B.
E. T. Specific surface area 170 m ² / g, triboelectric charge amount −42.
Image formation was performed in the same manner as in Example 9 except that 5 μc / g) was used. Image density is 1.2 at 20 ℃ / 10%
5 to 1.30; 1.43 to 1.5 at 23 ° C / 65%
1; 1.49 to 1.55 at 30 ° C./80%, and the environmental stability was lower than that of Example 9.

Comparative Example 10 Image formation was carried out in the same manner as in Example 9 except that titanium oxide was not used. Due to lack of fluidity, the image quality was significantly reduced from the initial stage.

Comparative Example 11 The titanium oxide of Production Example 10 was used as an external additive at a high temperature (800
Image formation was performed in the same manner as in Example 9 except that anatase type titanium oxide having a particle size of 300 mμ (triboelectric charge amount-1.3 μc / g) obtained by sintering was used. The image density is 1.19 to 1.29 at 20 ° C./10%; 23 ° C. /
It was 1.40 to 1.52 under 65% and 1.48 to 1.59 under 30 ° C./80%, and the environmental stability was decreased as compared with Example 9.

Example 14 100 parts of polyester resin obtained by condensation of propoxylated bisphenol and fumaric acid 4 parts of phthalocyanine pigment 4 parts of chromium complex salt of di-tert-butylsalicylic acid

The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder,
After cooling, it was roughly pulverized to about 1 to 2 mm by using a hammer mill, and then finely pulverized by an air jet type fine pulverizer. Further, the finely pulverized product obtained was classified to have an average particle size of 8.3.
Colorant-containing resin particles of μ (triboelectric charge amount-19.5 μc /
g) was obtained.

100 parts of the colorant-containing resin particles were synthesized from titanium isopropoxide by a gas phase decomposition method at 500 ° C. to have an average particle diameter of 18 mμ and a charge amount of −2.8 μc / g.
0.5 part of the titanium oxide fine particles and 20 parts of the silane coupling agent represented by the composition I are treated with silica fine powder Aerosil 300 (manufactured by Nippon Aerosil Co., Ltd.) (150 ° C., 2 hours).
r) A cyan toner was obtained by combining 0.4 parts of silica fine powder having an average particle size of 11 mμ and a charge amount of +30.5 μc / g.

[0184]

[Outside 6]

Weight average particle diameter 45 μ (4.2 is less than 35 μ)
% By weight, 35-40 μ has a particle size distribution of 9.5% by weight, and 74 μ or more has a particle size distribution of 0.2% by weight) Cu-Zn-Fe ferrite carrier, styrene-methyl methacrylate (40:60) copolymer (Weight average molecular weight about 120,0
(00) was dissolved in a xylene / methyl ethyl ketone mixed solvent, and 95 parts of a carrier coated with 0.5% resin and 5 parts of cyan toner were mixed to prepare a developer.

Using this developer, the development contrast 3
23 ° / 65 with a commercially available plain paper color copying machine (color laser copier 500, made by Canon) fixed at 00V
%, The obtained toner image is 1.5
It was as high as 2 and was clear without fog. After that, 20,000 copies were further made, and the density fluctuation during that time was as small as 0.07, and fog and sharpness similar to those at the initial stage were obtained. When image formation was performed under low temperature and low humidity (20 ° C./10%), the image density was as high as 1.48, which was effective in controlling the charge amount under low humidity.

When images were printed under high temperature and high humidity (30 ° C./80%), the image density was 1.55, which was very stable and good images were obtained. 23 ° C / 60% RH, 20 ° C /
No abnormality was found in the initial images after being left for 1 month in each environment of 10% and 30 ° C./80%.

Comparative Example 12 Image formation was carried out in the same manner as in Example 14 except that the titanium oxide fine particles were not used.
Fog was observed under / 10%, and toner was scattered during continuous copying, which is considered to be caused by defective mixing of the toner and the carrier. Therefore, the evaluation was stopped after 1000 sheets were printed.

Example 15 In Example 14, fine silica powder (charge amount + 53μ) treated with the following silane coupling agent instead of the composition I was used.
c / g, average particle diameter 12 mμ) 0.3 part was used, and image formation was carried out in the same manner as in Example 14, Example 14
Similar good results were obtained.

[0190]

[Outside 7] Example 16 In Example 14, titanium oxide obtained by treating titanium oxide with a titanium coupling agent (charge amount -11.5 μc / g,
Example 1 except using 0.7 parts of average particle size 20 mμ)
When images were printed out in the same manner as in Example 4, good results were obtained as in Example 14.

Example 17 A cyan toner prepared by mixing 1.0 part of titanium oxide fine particles and 0.3 part of silica fine powder in Example 14 was used.
When the developing unit of LC-500 was modified for a non-magnetic single component as shown in FIG. 1 and 3000 images were printed, good results without fog and toner scattering were obtained.

[0192]

INDUSTRIAL APPLICABILITY In the present invention, by using the above-mentioned specific external additive, the chargeability can be stabilized under various environments and a color image of excellent quality can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a developing device.

FIG. 2 is an explanatory diagram of an apparatus for measuring a triboelectric charge amount of a powder sample.

[Explanation of symbols]

 1 latent image carrier 2 developer carrier 3 hopper 4 supply roller 5 developer coating blade 6 power supply

Claims (7)

[Claims] 1. A toner for developing an electrostatic charge image, comprising at least colorant-containing resin particles and amorphous titanium oxide fine particles having a primary average particle size of 1 to 200 mμ. 2. The titanium oxide fine particles have a primary average particle size of 1 to
The electrostatic image developing toner according to claim 1, having a particle size of 100 mμ. 3. The titanium oxide fine particles have a primary average particle size of 1 to
The toner for developing an electrostatic charge image according to claim 1, having a particle size of 50 mμ. 4. The titanium oxide fine particles have a primary average particle diameter of 1 to 1.
The toner for developing an electrostatic charge image according to claim 1, having a particle size of 40 mμ. 5. The titanium oxide fine particles have an average dispersed particle diameter on the colorant-containing resin particles of 5 to 80 mμ, a toner bulk density of 0.35 to 0.5 g / cm ³ , and a toner aggregation degree. Is 2 to 15%, and the toner has a weight average particle diameter of 4 to 10 μm. 6. Titanium oxide fine particles are titanium oxide fine particles produced by vapor-phase thermal decomposition reaction from volatile titanium at a temperature of 600 ° C. or lower, and the titanium oxide fine particles are further triboelectrically charged with iron powder. Charged to the same polarity as the toner,
The absolute value is 30 μc / g or less, and the particle size is 10 mμ.
The toner for developing an electrostatic charge image according to claim 1, which is in a range from 1 to 200 mμ. 7. When the titanium oxide fine particles (external additive A) are triboelectrically charged with iron powder, the absolute value is 20 μc / g or less, and the other external additive (external additive B) is When the toner is triboelectrically charged with iron powder, it is charged in the opposite polarity to the toner and its absolute value is 10 μc / g or more, and the average particle diameter of the external additive A is a.
2. The toner for developing an electrostatic charge image according to claim 1, wherein a ≧ b, where μ is the average particle size of the external additive B, and b ≧.