JP2675950B2 - Toner for developing electrostatic images - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
Toner for developing electrostatic images in electrostatic printing,
In particular, it relates to color toner.

[0002]

2. Description of the Related Art It is well known in the art to form and develop an image on the surface of a photoconductive material by electrostatic means.

That is, US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-2
A number of methods are known, such as Japanese Patent No. 4748, but generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the toner is called a toner on the latent image. A toner image corresponding to an electrostatic latent image is formed by attaching an extremely finely pulverized inspection material.

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

[0005] A developing method for visualizing an electric latent image by using a toner is described in, for example, a powder cloud method described in US Pat. No. 2,221,776, and US Pat. No. 2,618,55.
No. 2,874,063, a magnetic brush method, and a conductive property described in 3,909,258. A method using a magnetic toner is known.

As a toner applied to these developing methods, a toner obtained by mixing and dispersing a colorant in a thermoplastic resin and then pulverizing the same is used. As the thermoplastic resin, a polystyrene resin is the most common, but a polyester resin, an epoxy resin, an acrylic resin, a urethane resin, or the like is also used. As a coloring agent, carbon black is most widely used, and in the case of a magnetic toner, iron oxide black magnetic powder is often used. In the case of using a so-called two-component developer, the toner is usually glass beads,
It is used by being mixed with carrier particles such as iron powder.

The toner image on the final copy image forming member such as paper is permanently fixed on the support by heat, pressure or the like. Conventionally, this fixing step has often been performed by heat.

When a step of transferring a toner image is provided, a step for removing residual toner on the photoreceptor is usually provided.

In recent years, the development of monocolor copying to full-color copying in copying machines and the like has been rapidly progressing, and the study and commercialization of two-color copying machines and full-color copying machines have been greatly increased. For example, “Journal of the Society of Electrophotography,” Vol.
22, no. 1 (1983) and "Journal of the Institute of Electrophotography" Vo
l 25, No. 1, P52 (1986).

However, it is not immediately compared with the real thing like a television, a photograph, and a color printed matter, and for people who can see a color image which is more beautifully processed than the real thing, the full-color electrophotography currently in practical use. Images are not always pleasing.

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

In the method, first, an electrostatic latent image is formed on a photoconductive layer by passing light from a document through a color separation light transmitting filter having a complementary color relationship with the color of the toner, and then the toner is developed and transferred. Hold on the support. This process is sequentially performed a plurality of times, and while the registration is being performed, the toner is overlaid on the same support, and the final full-color image is obtained by one-time fixing.

Generally, in the case of a so-called two-component developing system in which a developer is composed of a toner and a carrier, the developer charges the toner to a required charge amount and charge polarity by friction with the carrier, and utilizes electrostatic attraction. Therefore, in order to obtain a good visible image, it is necessary for the toner to have good triboelectric charging properties mainly determined by the relationship with the carrier.

[0014] To solve the above-mentioned problems, search for a carrier core agent and a carrier coating agent and optimization of the coating amount, or study of a charge control agent and a fluidity imparting agent to be added to the toner, and further, a binder as a base Many studies have been made to achieve excellent triboelectrification in all materials constituting a developer, such as improvement of the developer.

For example, Japanese Patent Publication No. 52-25656 discloses a technique for adding a charge auxiliary agent such as chargeable fine particles to a toner.
JP-A-56-64352 and JP-A-61-160760 each add a fine resin powder having a polarity opposite to that of a toner to a developer.
Techniques for obtaining stable triboelectric charging properties have been proposed, and many charging aids have been developed today.

Further, various techniques have been devised as a method for adding the charging auxiliary as described above. For example, a method of attaching the toner particles to the surface of the toner particles by electrostatic force or van der Waals force between the toner particles and the charge auxiliary agent is generally used, and a stirrer, 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 particles, and the presence of the additive which has not been attached to the toner particles but aggregated with each other and is in a so-called free state is considered. It is difficult to avoid. This tendency becomes more conspicuous as the specific electrical resistance of the charging aid increases and as the particle size decreases. In such a case, the performance of the toner is affected. For example, the amount of triboelectric charge becomes unstable, the image density is not constant, and the image has a lot of fog.

If continuous copying or the like is carried out, the content of the charging auxiliary agent changes and the initial image quality cannot be maintained, which is a problem.

As another addition method, there is a method in which a charging auxiliary is added in advance together with a binder resin and a colorant at the time of manufacturing a toner. However, it is not easy to make the charge control agent uniform, and it is substantially in the vicinity of the toner particle surface that contributes to the chargeability, and the charge auxiliary agent and the charge control agent present inside the toner particles are charged. Therefore, it is not easy to control the amount of the charge auxiliary agent added and the amount of dispersion on the surface. Also, 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. The fact is that satisfactory quality has not been obtained.

In recent years, the demand for higher definition and higher image quality of copying machines has been increasing in the market, and in the technical field, attempts have been made to achieve high image quality and color by reducing the particle size of toner. However, as the particle size becomes smaller, the surface area per unit weight tends to increase, and the amount of charge of the toner tends to increase. In addition, since the charged amount of the toner is large, the adhesion between the toners is strong, the fluidity is reduced, and problems occur in the stability of toner supply and in the application of tribo to the supplied toner.

Further, since the color toner does not contain a conductive substance such as a magnetic material or carbon black, there is no portion for leaking the charge, and the amount of charge generally tends to increase. This tendency is more remarkable especially when a polyester binder having high charging performance is used.

In particular, in the case of a color toner, the following properties are strongly desired. (1) The toner needs to have a good fixing property. (2) The toner must have good hue and spectral reflection characteristics and sufficient saturation.

From this point of view, many binder resins have been studied, but a toner satisfying all the above characteristics has not yet been developed. Today, polyester resins are widely used as binder resins for color in the technical field. However, toners made of polyester resins are generally easily affected by temperature and humidity, and have an excessive charge amount under low humidity and high humidity. Under such circumstances, there arises a problem such as insufficient charge amount, and there is an urgent need to develop a color toner having a stable charge amount even in a wide range of environments.

Color toners such as yellow toners, magenta toners, and cyan toners do not contain a conductive substance such as a magnetic substance or carbon black, and therefore, there is no portion for leaking triboelectric charges to the toner, and the triboelectric charge amount of the toner is generally present. Tends to grow. This tendency is particularly remarkable when a polyester binder having high triboelectrification performance is used as a binder resin for the toner.

In the color toner for forming a full color image, the following characteristics are strongly desired. (1) To prevent the fixed toner from interfering with color reproduction due to diffused reflection of light, the toner particles need to be in a state of being almost completely melted at the time of fixing and deformed to the extent that the shape cannot be discriminated. (2) The color toner must have transparency so that the upper toner layer does not interfere with the color tone of the lower toner layer having a different color tone. (3) Each color toner must have well-balanced hue and spectral reflection characteristics and sufficient saturation.

Today, polyester resins are often used as binder resins for full-color toners. As described above, a toner containing a polyester resin is generally easily affected by temperature and humidity, and problems such as excessive triboelectric charge amount under low humidity and insufficient triboelectric charge amount under high humidity tend to occur.
Development of color toners and developers having a stable charge amount in a wide range of environments is desired.

[0026]

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

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

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

An object of the present invention is to provide a color toner for developing an electrostatic charge image capable of forming a clear color OHP image without turbidity.

[0030]

Specifically, according to the present invention, in a toner for developing an electrostatic image containing at least a colorant-containing resin particle and an external additive, the colorant-containing resin particle has a weight average. The particle size (D ₄ ) is 5 to 10 μm, the external additive has an average particle size of 0.01 to 0.2 μm, and the hydrophobicity is 2
For electrostatic image development, which is a hydrophobic anatase type titanium oxide fine powder treated with a silane coupling agent having 0 to 98% and a light transmittance of 40% or more for a light wavelength of 400 nm. Regarding toner.

The present inventor has made earnest studies on stabilization of chargeability of electrostatic image developing toners (particularly non-magnetic color toners). As a result, the hydrophobic agent treated with the above-mentioned silane coupling agent as an external additive. The present inventors have found that the anatase-type titanium oxide fine particles having excellent properties are extremely effective in terms of stabilization of charging, imparting fluidity, environmental stability, and the like, and arrived at the present invention.

This is difficult to achieve with the generally known hydrophobic silica as a flow improver.

The reason for this is that the silica fine particles themselves have a strong negative chargeability, whereas the titanium fine particles have a substantially neutral chargeability. Although it has been conventionally proposed to add hydrophobic titanium oxide fine particles,
Titanium oxide fine particles originally had a smaller surface activity than silica, and were not necessarily sufficiently hydrophobized. Further, when a large amount of a treating agent or the like or a highly viscous treating agent is used, the degree of hydrophobicity is certainly increased, but coalescence of particles occurs and the fluidity-imparting ability is reduced, etc. It was not always possible to achieve both the stabilization of charging and the imparting of fluidity.

The use of anatase-type titanium oxide fine particles has been proposed, for example, in Japanese Patent Laid-Open No. 60-112052, but the anatase-type titanium oxide fine particles have a volume resistivity value of about 10 ⁷ Ω · cm. When used as it is, the triboelectric charge leaks quickly under high humidity, and it is not always satisfactory in terms of stabilizing the charging of the toner, and it is necessary to improve it.

Further, as an example of containing a hydrophobized titanium oxide in a toner, Japanese Patent Application Laid-Open No. 59-52255 proposes a toner containing titanium oxide treated with alkyltrialkoxysilane. ,
Although the electrophotographic characteristics of the toner have certainly improved,
The surface activity of titanium oxide was originally small, and coalesced particles were generated at the stage of treatment, or the hydrophobicity was nonuniform, and therefore it was not always satisfactory when applied to a color toner for full-color image formation.

The inventors of the present invention have made earnest studies on the stability of chargeability of the toner, and as a result, have an average particle diameter of 0.01 to 0.2 μm.
m, a hydrophobicity of 20 to 98%, and a toner containing a hydrophobic anatase type titanium oxide fine powder treated with a silane coupling agent having a light transmittance of 40% or more for a light wavelength of 400 nm as an external additive. In addition, they have found that they are extremely effective in terms of stabilizing charging and imparting fluidity.

The anatase type titanium oxide fine particles can be produced by using titanium chloride as a raw material.

Since the untreated anatase type titanium oxide fine particles have hydrophilicity, the degree of hydrophobicity is 20 to 98%.
The hydrophobic anatase type titanium oxide fine particles having (preferably 20 to 80%) have to make the hydrophilic anatase type titanium oxide fine particles hydrophobic.

As a preferred method for hydrophobizing the anatase-type titanium oxide fine particles, a method of hydrolyzing the coupling agent while dispersing the anatase-type titanium oxide fine particles to have a primary particle size in an aqueous medium and surface-treating In this hydrophobic treatment method, the titanium oxide fine particles are less likely to coalesce with each other than in the gas phase, and the electrostatic repulsion action between the titanium oxide fine particles due to the hydrophobic treatment works. The surface is treated in the state of almost primary particles.

The method of treating the surface of titanium oxide while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent such as chlorosilanes or silazanes that generate a gas, and further, Titanium oxide fine particles easily coalesce with each other in the gas phase, and a highly viscous coupling agent, which has been difficult to treat well, can now be used, and the effect of hydrophobization is great.

Examples of the coupling agent usable in the present invention include a silane coupling agent and a titanium coupling agent. A silane coupling agent is more preferably used, which has the general formula R _m SiY _n [wherein R represents an alkoxy group, m represents an integer of 1 to 3, Y represents an alkyl group, a vinyl group, or a glycidoxy group. ,
A hydrocarbon group such as a methacryl group is shown, and n is an integer of 1 to 3. ]. For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane,
Dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyritrimethoxysilane, phenyltrimethoxysilane, n-
Hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, etc. can be mentioned.

[0042] In particular, the formula _{C p H 2p + 1 -Si- (} OC q H
_{2q + 1} ) ₃ [In formula, p shows the integer of 3-12, q is 1-
It is preferable to hydrophobize the anatase type titanium oxide fine particles in an aqueous medium using an alkyltrialkoxysilane coupling agent represented by the formula [3].

When p in the above formula is smaller than 3, the hydrophobic treatment is easy, but it is difficult to impart sufficient hydrophobicity, and when p is larger than 12, the hydrophobicity is sufficient. However, the coalescence of the titanium oxide particles increases, and the fluidity imparting ability is likely to decrease.

When q is larger than 3, the reactivity of the silane coupling agent is lowered and it becomes difficult to sufficiently hydrophobize the silane coupling agent.

Particularly, alkyltri in which p in the formula represents an integer of 3 to 12 (more preferably an integer of 3 to 8) and q represents an integer of 1 to 3 (more preferably an integer of 1 or 2). It is better to use an alkoxysilane coupling agent.

The treatment amount is 1 to 50 parts by weight, preferably 3 to 40 parts by weight, based on 100 parts by weight of titanium oxide, and the degree of hydrophobicity is 20 to 98%, preferably 20 to 80.
%, More preferably 40 to 80%.

If the degree of hydrophobicity is less than 20%, the amount of charge is greatly reduced by leaving it for a long time under high humidity, and a mechanism for promoting triboelectric charging on the hardware side is required, which complicates the developing device.
On the other hand, if the hydrophobicity exceeds 98%, it becomes difficult to control the triboelectric charge of titanium oxide itself even if anatase type titanium oxide having a small volume resistivity is used, and as a result, the toner is likely to be charged up under low humidity.

The average particle size of the titanium oxide fine powder having hydrophobicity is preferably 0.01 to 0.2 μ from the viewpoint of imparting fluidity. If the average particle diameter is larger than 0.2 μm, the triboelectric charge of the toner is likely to be non-uniform due to poor fluidity, resulting in toner scattering and fog. On the other hand, when the average particle size is smaller than 0.01 μm, the particles are likely to be embedded in the surface of the colorant-containing resin particles, toner deterioration is likely to occur quickly, and the durability is likely to decrease. This tendency is particularly remarkable in the sharp-melting color toner in which the melt viscosity is rapidly reduced by heating.

The primary average particle diameter of titanium oxide in the present invention is 120,000 times and is 10 from the transmission electron micrograph.
The average primary particle size of 00 particles is taken.

Further, in the present invention, the treated titanium oxide fine powder has a light transmittance of 4 at a light length of 400 nm.
It is preferably 0% or more for forming a good color image on the OHP film.

The hydrophobized titanium oxide fine powder used in the present invention has a very small primary particle size of 0.2 to 0.01 μm, but when it is actually contained in the toner, it is not always the primary particle size. The particles are not dispersed, but may be present as secondary particles. Therefore, no matter how small the primary particle size is, the effect of the present invention will be reduced if the effective particle size of the secondary particles behaving is large. However, the higher the light transmittance at 400 nm, which is the lower limit wavelength in the visible region, the smaller the secondary particle size,
Good results such as the ability to impart fluidity and the sharpness of the projected image of OHP are obtained.

On the other hand, when the titanium oxide fine powder having a poor transparency to visible light is externally added to the color toner for forming a full-color image, when the OHP film having the full-color image is projected, the projected image is eclipsed. It becomes difficult to obtain a clear full-color projection image.

The crystal form of titanium oxide was determined by X-ray diffraction.
Confirm that the anatase type has a lattice constant (a) of 3.78 Å and a lattice constant (b) of 9.49 Å.

As a method for obtaining hydrophobic titanium oxide fine particles, volatile titanium alkoxide or the like is oxidized at a low temperature,
After obtaining spherical titanium oxide fine particles, there is a method of performing surface treatment to obtain amorphous spherical titanium oxide, but considering that the starting material is expensive and the manufacturing apparatus is complicated, it is used in the present invention. The hydrophobic anatase-type titanium oxide fine powder can be easily produced, which is advantageous in terms of cost.

In the present invention, the aqueous medium is a medium containing water as a main component. Specifically, water itself as an aqueous medium, water with a small amount of a surfactant added,
Examples include water to which a pH adjusting agent is added and water to which an organic solvent is added. The surfactant is preferably a nonionic surfactant such as polyvinyl alcohol.
The surfactant is preferably added in an amount of 0.1 to 5 wt% with respect to water. Examples of pH adjusters include inorganic acids such as hydrochloric acid.

It is preferable that 0.1 to 10 parts by weight of titanium oxide fine powder is added to and mixed with 100 parts by weight of an aqueous medium and treated with a hydrophobizing agent.

Stirring is carried out, for example, by a mixer having stirring blades (specifically, a high shearing force mixing device such as an attritor or a TK homomixer) so that the titanium oxide fine powder becomes primary particles in an aqueous medium. It is good to do enough.

The titanium oxide fine powder hydrophobized with the silane coupling agent in the aqueous medium is further surface-treated so that the hydrophobic titanium oxide fine particles do not coalesce with the silane coupling agent in the gas phase. good. The purpose is to further seal the functional group of titanium oxide remaining after the treatment in the aqueous medium with a silane coupling agent, but surprisingly, its reactivity is extremely high because it is once treated in the aqueous system. Very expensive. The reason for this is not clear yet, but since it has been organically treated in a water system in advance, it is well compatible with the site other than the reactive group of the silane coupling agent and the site of the lipophilic group of the titanium oxide fine particles, It is presumed that this is because the reaction efficiency is enhanced.

The silane coupling agent used for the hydrophobic treatment in the gas phase has a general formula R _m SiY _n [wherein R represents an alkoxy group or a chlorine atom, m
Represents an integer of 1 to 3, Y represents a hydrocarbon group such as an alkyl group, a vinyl group, a glycidoxy group or a methacryl group,
n shows the integer of 1-3. ] The thing shown by is mentioned. For example, typically, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, Examples thereof include vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane and the like.

The silane coupling agent treatment of the titanium oxide fine powder may be a dry treatment in which the vaporized silane coupling agent is reacted with the surface-treated titanium oxide fine powder in the form of a cloud by stirring or the like. The silane coupling agent is 1 to 2 with respect to 100 parts by weight of the fine powder.
It is good to treat 0 part by weight, more preferably 3 to 10 parts by weight. The hydrophobic anatase type titanium oxide fine powder is preferably contained in the toner in an amount of 0.02 to 3% by weight.

The titanium oxide of the present invention is also suitable when the toner has a small particle size (for example, a weight average particle size of 5 to 10 μm, preferably 5 to 9 μm). When the particle size of the toner is reduced, the surface area per weight increases, and excessive charging due to rubbing is likely to occur. On the other hand, titanium oxide fine particles which can control charging and impart fluidity have a great effect.

In the present invention, the external additive has a polarity opposite to that of the colorant-containing resin particles and an average particle diameter of 0.5 to 0.02.
It is also preferable to add organic resin particles each having a distribution peak in the region of μ, preferably in the region of 0.2 to 0.02 μ and the region of 0.3 to 0.8 μ.

The reason is that the charge-up of the toner used in the present invention is neutralized by the above-mentioned organic resin particles.

Furthermore, by adding the organic resin particles, the rise of the charging of the toner is promoted, and very stable charging characteristics are achieved from the initial stage.

The reason for this is not clear yet, but it is presumed as follows. That is, the organic resin particles are strongly attracted and charged toward the charging member rather than the colorant-containing resin particles at the beginning of the rubbing of the toner with the charging member such as a carrier. Therefore, the rising of the charging of the resin particles containing the colorant having the opposite polarity is promoted. On the other hand, after once rising, on the contrary, it is more strongly attracted to the colorant-containing resin particles than the charge-imparting member, and functions to neutralize excessive charge. The charge level can be maintained in good and stable condition in various environments.

In order to make the above action more effective, it is preferable that the organic resin particles have a peak in each of a region having a particle diameter of 20 to 200 mμ and a region having a particle diameter of 300 to 800 mμ. The abundance ratio of the larger peak is 2 to 20% by weight, preferably 3 to 13% by weight. When the average particle diameter is smaller than the above range, the organic resin particles adhere too strongly to the colorant-containing resin particles or are embedded therein, and the above-mentioned effects disappear. On the other hand, if it is larger than the above range, the dispersion becomes non-uniform or liberates, and the effect is lost.

In the present invention, it is preferable to add 0.1 to 5.0% by weight to the colorant-containing resin particles in order to surely exhibit the performance and to have a stable negative charging property.

Furthermore, the organic resin particles of the present invention are suitable even when the toner has a small diameter.

That is, when the diameter of the toner is reduced, the number of contact points between the toner and the carrier is increased and carrier spent is likely to occur, or the number of contact points between the toner and toner is increased, and toner blocking is likely to occur. On the other hand, spherical organic resin particles having an appropriate size of 0.2 to 0.02 μ as organic resin particles serve as a good spacer and give good results. For the toner blocking, it is more effective to use the opposite polarity resin particles having a higher Tg than the toner resin.

There are some examples in which resin particles of opposite polarity are added to the toner. For example, in JP-A-54-45135 and JP-B-52-32256, colorless resin particles smaller than the toner particles are used. Addition is suggested.

However, in these examples, the toner and the opposite polarity resin particles behave separately, and the toner adheres to the latent image portion during development, whereas the opposite polarity resin particles adhere to the background portion.

That is, the reverse polarity resin particles have a function of promoting the charging of the toner. However, in the present invention, reverse polarity resin particles that are sufficiently smaller than the toner particle size are used, and finally, they are strongly adhered to the toner and developed together, and the transfer residue has a relatively rough side of 300 to 800 mμ. This is different from the above-mentioned invention because it is characterized in that the resin particles of (4) are appropriately left to improve the cleaning property.

More recently, there has been proposed a system in which silica and organic resin particles are used at the same time, as disclosed in JP-A-1-113767, but these are used for weakening the adhesion between the drum and the toner. There is something. However, in the present invention, the structure having the function of weakening the adhesive force on the drum side is used for the purpose of further improving the cleaning characteristics, that is, for the purpose of appropriately removing foreign substances on the drum. Therefore, the present invention is different from the above invention.

In Japanese Patent Publication No. 2-3172, etc., a system to be used has been proposed for the purpose of not lowering the charge of the toner, but in the present invention, a non-magnetic color toner which tends to be excessively charged is used. On the other hand, it is a different invention because it is positively used to reduce the charge.

The monomer constituting the reverse polarity resin particles used in the present invention is not particularly limited, but it is necessary to select it in consideration of the charge amount of the toner and the like. Specific examples of the addition-polymerizable monomer that can be used in the present invention include the following monomers.

That is, styrene and its derivatives such as alkylstyrene such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene, fluorostyrene. , Chlorostyrene,
Examples include halogenated styrenes such as bromostyrene, dibromostyrene, and iodostyrene, and nitrostyrene, acetylstyrene, and methoxystyrene.

Further, addition-polymerizable unsaturated carboxylic acids such as acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, α-methylcrotonic acid, α-ethylcrotonic acid, isocrotonic acid, tiglic acid, and ungeric acid are used. Examples thereof include addition-polymerizable unsaturated aliphatic monocarboxylic acids, and addition-polymerizable unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, and dihydromuconic acid.

Further, a metal salt of these carboxylic acids may be used, and the metal salt may be added after completion of the polymerization.

The addition-polymerizable unsaturated carboxylic acid and alkyl alcohol, halogenated alkyl alcohol,
Examples thereof include an esterified product with an alcohol such as an alkoxyalkyl alcohol, an aralkyl alcohol and an alkenyl alcohol. And, 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, and 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; and alkenyl alcohols such as allyl alcohol and crotonyl alcohol.

Amides and nitriles derived from the above-mentioned addition-polymerizable unsaturated carboxylic acids; aliphatic monoolefins such as ethylene, propylene, butene and isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, 1,2-
Dichloroethylene, 1,2-dibromoethylene, 1,2
-Diiodoethylene, isopropenyl chloride, isopropenyl bromide, allyl chloride, allyl bromide, vinylidene chloride,
Halogenated aliphatic olefins such as vinyl fluoride and vinylidene fluoride; 1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene; , 4-hexadiene, 3-
Examples thereof include 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.

Polymerization of one or more of these monomers can be used.

The reverse polarity resin particles used in the present invention are not limited to using only one kind, and a plurality of kinds can be used in combination.

Further, as a method for producing the reverse polarity resin particles used in the present invention, a spray drying method, a suspension polymerization method,
Any method that can produce spherical fine particles, such as an emulsion polymerization method, a soap-free polymerization method, a seed polymerization method, and a mechanical pulverization method, can be used. Among them, a soap-free polymerization method, which has no residual emulsifier and does not hinder the chargeability of the toner and has little environmental change in specific electric resistance, is particularly suitable, but is not particularly limited.

In order to have two peaks in the distribution of resin particles, two kinds of resin particles may be dry blended or wet blended and then dried, but preferably,
It is more preferable that the primary particles are appropriately coalesced to achieve two peaks when the emulsion is dried after the polymerization. Further, if necessary, heat treatment or crushing treatment may be performed.

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. A method of adsorbing a substance or the like by ion adsorption or external addition, a pigment or a dye, and 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 must have a peak molecular weight in the range of 10,000 to 5,000,000,
It is 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 and the blocking resistance is deteriorated.

The toner according to the present invention may contain a charge control agent in the colorant-containing resin particles 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 toner is preferable. Examples of the negative charge control agent at that time 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 added to the toner, it is preferably added in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the binder resin.

When a toner according to the present invention and a carrier are mixed to prepare a two-component developer, the mixing ratio is 2 to 12% by weight, preferably 3% by weight as the toner concentration in the developer.
Good results are usually obtained with -9% by weight. If the toner density is less than 2% by weight, the image density tends to be low.
If it exceeds 0% by weight, fog and scattering in the machine are increased, and the useful life of the developer is likely to be shortened.

As the colorant used in the present invention, known dyes and pigments such as phthalocyanine blue, indanthrene blue, peacock blue, permanent red, lake red, rhodamine lake, hansa yellow, permanent yellow, benzidine yellow and the like are widely used. can do. The content thereof is 12 parts by weight or less, preferably 0.5 to 9 parts by weight with respect to 100 parts by weight of the binder resin that sensitively reflects the transparency of the OHP film.
Parts by weight.

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 Teflon, zinc stearate, and polyvinylidene fluoride. Such lubricants, fixing aids (for example, low molecular weight polyethylene, low molecular weight polypropylene, etc.) organic resin particles, and the like.

In the production of the colorant-containing resin particles used in 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 and classified. Method: A method in which a material such as a colorant is dispersed in a binder resin solution and then spray-dried; or a predetermined material is mixed with a monomer that constitutes the binder resin, and then this emulsion suspension is used. A suspension polymerization method or the like in which the colorant-containing resin particles are obtained by polymerizing the liquid can be applied.

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

For example, polystyrene, styrene-based copolymers such as styrene-butadiene copolymer, styrene-acrylic copolymer, etc., ethylene-based such as polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer. Examples thereof include copolymers, phenol resins, epoxy resins, acrylic phthalate resins, polyamide resins, polyester resins, maleic acid resins and the like. In addition, the production 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. That is, the polyester-based resin has excellent fixability and is suitable for a color toner, but has a high negative charging ability and tends to be excessively charged. A toner is obtained.

In particular, the following equation

[0097]

[Outside 1] (In the formula, R ₁ and R ₂ represent an ethylene or propylene group, x and y each represent an integer of 1 or more, and x + y
The average value of is 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 consisting of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof (for example, fumaric acid, maleic acid, maleic anhydride, Polyester resins obtained by copolycondensation of phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) are more preferable because they have sharp melting characteristics.

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

As the monomer for the resin for coating the carrier core material which can be used in the present invention, as the styrene-based monomer,
For example, styrene monomer, chlorostyrene monomer, α
-Methylstyrene monomer, styrene-chlorostyrene monomer and the like. Examples of the acrylic monomer include, for example, acrylate monomer (methyl acrylate monomer, ethyl acrylate monomer, butyl acrylate monomer, octyl acrylate monomer, phenyl acrylate monomer) And methacrylic acid ester monomers (methyl methacrylate monomer, ethyl methacrylate monomer, butyl methacrylate monomer, phenyl methacrylate monomer).

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, rare earths, and alloys or magnetic materials thereof. Oxides such as ferrite can be used. Also, there is no particular restriction on the manufacturing method.

Preferably, it contains 98% by weight or more of a magnetic ferrite carrier having a metal composition ratio of copper, zinc and iron of 5 to 20: 5 to 20:30 to 80 (weight ratio).

Next, an example of an image forming apparatus in which non-magnetic one-component development is performed using the toner of the present invention will be described, but the present invention is not limited to this. In FIG.
2 shows an apparatus for developing an electrostatic image formed on a latent image holding member. Reference numeral 1 denotes a latent image holder, which is formed by an electrophotographic process means or an electrostatic recording means (not shown). 2
Denotes a developer carrier, which is formed of a nonmagnetic 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 by the supply roller 4 onto the developer carrier. The supply roller 4 also removes the toner on the developer carrier after development. The toner supplied onto the developer carrier is uniformly and thinly applied by the developer applying blade 5.
The contact pressure between the developer coating blade and the developer carrying member is effectively 3 to 250 g / cm, preferably 10 to 120 g / cm as the linear pressure in the sleeve generatrix direction. If the contact pressure is less than 3 g / cm, it becomes difficult to apply the toner uniformly, and the toner charge amount distribution becomes broad, causing fog and scattering. If the contact pressure exceeds 250 g / cm, a large pressure is applied to the toner, and the toner particles are aggregated or crushed, which is not preferable. By adjusting the contact pressure to 3 to 250 g / cm, it becomes possible to loosen the agglomeration peculiar to the toner having a small particle diameter, and it is possible to instantly raise the charge amount of the toner. As the developer coating blade, it is preferable to use a material of triboelectric charging series 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. Further, it may be coated with a polyamide resin or the like. Use of a conductive rubber or the like is preferable because the toner can be prevented from being excessively charged.

In the system proposed in the present invention for coating a thin layer of toner on a developer carrying member with a blade, the thickness of the toner layer on the developer carrying member is adjusted to obtain a sufficient image density. It is necessary to make it smaller than the facing gap length between the developer carrying member and the latent image holding member, and apply an alternating electric field to this gap. That is, by applying an alternating electric field or a developing bias in which a DC electric field is superimposed on the alternating electric field between the developer carrier and the latent image carrier by the bias power source 6 shown in FIG. The transfer of the toner onto the body is facilitated, and a higher quality image can be obtained.

The measuring method of the present invention will be described below.

(1) Particle Size Measurement of Colorant-Containing Resin Particles and Toner The particle size distribution can be measured by individual methods, but in the present invention, it was measured using a Coulter counter.

That is, a Coulter counter TA-II type (manufactured by Coulter) is used as a measuring device, and an interface (manufactured by Nikkaki) for outputting number average distribution and volume distribution and a CX-1 personal computer (manufactured by Canon) are connected. Then, the electrolyte is 1
% NaCl aqueous solution is prepared. As a measuring method, a surfactant, preferably an alkylbenzene sulfonate, is used as a dispersant in 100 to 150 ml of the electrolytic aqueous solution.
Add 5 ml, and further add 2-20 mg of the measurement sample.
The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of the sample were measured with the Coulter Counter TA-II type using a 100 μm aperture as an aperture. The volume distribution and number distribution of ˜40 μm were calculated. Then, according to the present invention, the weight-average weight average diameter (D
4) (The median value of each channel is taken as a representative value for each channel), the amount of weight-based coarse powder (1
6.0 μm or more), and the number-based fine powder number (5.04 μm or less) determined from the number distribution.

(2) Measurement of Hydrophobicity The hydrophobicity of the titanium oxide fine powder having a hydrophobized surface is measured as follows.

A water / methanol mixed solution of which the total amount is 100 ml is put into a 250 ml glass bottle with a stopper by changing various mixing ratios of water and methanol.

After 0.2 g of the sample was added and mixed for 10 minutes by a paint conditioner manufactured by Red Devil Co.,
The degree of hydrophobicity is measured as a percentage of methanol in a mixed solution of methanol and water in a state where the whole sample is wet.

(3) Method for Measuring Transmittance Sample 0.10 g Alkyd resin (Beckosol 1 manufactured by Dainippon Ink and Chemicals, Inc.)
323-60-EL) 13.20 g melamine resin (Dainippon Ink and Co., Ltd. Super Beckamine J-820-60) 3.30 g thinner (Kansai Paint Co., Ltd. amylak thinner)
3.50 g glass media 50.00 g a. Collect the above material in a glass bottle with a stopper of 150 ml,
Disperse for 1 hour with a paint conditioner manufactured by Red Devil. b. After the dispersion, the PET film sheet is coated with a 2 mil doctor blade. c. The coated film obtained in b) is heated at 120 ° C. for 10 minutes and baked. (D). The coated film sheet obtained in c is U-manufactured by JASCO
The transmittance is measured by BEST 50 in the range of 320 to 800 nm and compared.

Further, the titanium oxide fine powder or the treated titanium oxide fine powder was dispersed in ethanol at a solid content concentration of 0.1 wt%, and 400 was obtained using Shimadzu Corporation UV2200.
The light transmittance at the light wavelength of nm may be measured.

(4) Particle Size Measuring Method for Organic Resin Particles Apparatus Coulter Counter N4 type is used as a measuring apparatus and Tommy Seiko UD-200 type is used as an ultrasonic generator for dispersion. Method An appropriate amount of sample is put into 30 to 50 ml of distilled water to which a trace amount of a surfactant is added, and the output from the ultrasonic generator is 2 to 2.
6. Disperse for about 2 to 5 minutes. The suspension in which the sample is dispersed is transferred to a cell, and after the air bubbles are released, the suspension is set in the above-mentioned coulter counter in which the measurement temperature is set to 50 ° C. in advance. The measurement is started after elapse of 10 to 20 minutes in order to keep the sample at a constant temperature, and the volume average particle size distribution is determined.

[0114]

EXAMPLES Production examples and examples according to the present invention will be described below. "Parts" and "%" indicate "parts by weight" and "% by weight".

Production Example 1 Anatase-type hydrophilic titanium oxide fine powder (average particle size: 0.
1 part of 05 μm and BET specific surface area of 120 m ² / g) was added to 100 parts of an aqueous medium consisting of water and stirred sufficiently to obtain a silane coupling agent (n-C ₄ H ₉ Si (OCH ₃ )).
₃ ) Add 0.2 parts to an aqueous medium and stir it sufficiently so that the titanium oxide fine particles do not coalesce. After stirring, filter, dry and lightly crush to give an average particle size of 0.05 μm.
Thus, anatase type treated titanium oxide fine powder I having a hydrophobicity of 70% and a light transmittance of 60% for a light wavelength of 400 nm was obtained. It was confirmed by fluorescent X-ray analysis that the obtained treated titanium oxide fine powder I was treated with about 20% by weight (about 25 parts by weight of silane coupling agent per 100 parts by weight of titanium oxide) of a silane coupling agent. Was done.

Production Example 2 n-C ₆ H ₁₃ Si (OCH) as a silane coupling agent
₃₎ except using ₃ 15 parts of anatase type hydrophilic titanium oxide fine powder to hydrophobic treatment with water in the same manner as in Preparation Example 1, the average particle size of 0.05 .mu.m, the degree of hydrophobicity Anatase type treated titanium oxide fine powder II having 60% and a transmittance of 55% for a light wavelength of 400 nm II
I got

Production Example 3 n-C ₁₀ H ₂₁ Si (OCH) as a silane coupling agent
₃₎ except using ₃ 15 parts of anatase type hydrophilic titanium oxide fine powder to hydrophobic treatment with water in the same manner as in Preparation Example 1, the average particle size of 0.05 .mu.m, the degree of hydrophobicity Anatase type treated titanium oxide fine powder II having 70% and a transmittance of 45% for a light wavelength of 400 nm II
I was obtained.

Production Example 4 Anatase-type hydrophilic titanium oxide fine powder (average particle size: 0.
05 μm, BET specific surface area 120 m ² / g) was added to water, and n-C ₆ H ₁₃ Si (O
CH ₃ ) ₃ is added and mixed so that the titanium oxide fine particles do not coalesce to 20% by weight with respect to the titanium oxide fine powder, dried and crushed to have a hydrophobicity of 40%, and an average particle diameter of 0. Anatase-type treated titanium oxide fine powder IV having a light transmittance of 55% for a light wavelength of 400 nm of 0.055 μm was obtained.

Production Example 5 Anatase-type hydrophilic fine powder was hydrophobized in water in the same manner as in Production Example 4 except that phenyltrimethoxysilane was used as the silane coupling agent, and the average particle size was 0. 0.05 μm, the degree of hydrophobicity is 30%, and 4
Anatase-type treated titanium oxide fine powder V having a light transmittance of 60% for a light wavelength of 00 nm was obtained.

Production Example 6 The treated titanium oxide fine powder IV obtained in Production Example 4 was further treated with 5% by weight of (CH ₃ ) ₂ Si (OCH ₃ ) ₂ in the gas phase to give an average particle diameter of 0.05 μm. And the degree of hydrophobicity is 50%
And has a light transmittance of 50% for a light wavelength of 400 nm.
Anatase-type treated titanium oxide fine powder VI was obtained.

Comparative Production Example 1 CH ₃ Si (OC ₂ H ₅ ) as a silane coupling agent
An average particle diameter of 0.05 μm and a degree of hydrophobicity of 15% as in Production Example 1 except that ₃ is used.
A treated titanium oxide fine powder VII having a transmittance of 50% for a light wavelength of 400 nm was obtained.

Comparative Production Example 2 Anatase type hydrophilic titanium oxide fine powder (average particle size 0.0
5 μm, BET specific surface area 120 m ² / g) was sintered by high temperature heating to obtain rutile type hydrophilic titanium oxide fine powder having an average particle size of 0.3 μm. The obtained rutile-type hydrophilic titanium oxide fine powder was subjected to a hydrophobic treatment in the same manner as in Production Example 1 to have an average particle size of 0.3 μm and a degree of hydrophobicity of 80%.
A rutile-type treated titanium oxide fine powder VIII having a transmittance of 10% for a light wavelength of 400 nm was obtained.

Comparative Production Example 3 Anatase-type hydrophilic titanium oxide fine powder (average particle size: 0.
05 μm, BET specific surface area 120 m ² / g) was subjected to hydrophobic treatment with nC ₆ H ₁₃ Si (OCH ₃ ) ₃ in a gas phase,
A treated titanium oxide fine powder IX having an average particle diameter of 0.06 μm, a hydrophobicity of 50%, and a light transmittance of 25% for a light wavelength of 400 nm was obtained.

Comparative Production Example 4 Hydrophilic titanium oxide fine powder (average particle size 0.4 μm, BET
A treated titanium oxide fine powder X having an average particle diameter of 0.4 μm and a degree of hydrophobicity of 50% was obtained in the same manner as in Production Example 4 except that a specific surface area of 12 m ² / g) was used.

Comparative Production Example 5 The treated titanium oxide fine powder IV was further treated with 10% by weight of 500 centistokes dimethylpolysiloxane to have an average particle size of 0.07 μm and a hydrophobicity of 85%. A treated titanium oxide fine powder XI having a light transmittance of 30% for a light wavelength of 400 nm was obtained.

Comparative Production Example 6 The treated titanium oxide fine powder IV was mixed with 30% by weight of n-C ₁₆ H.
Further treatment with ₃₃ Si (OCH ₃ ) ₃ resulted in an average particle size of 0.
06 μm, hydrophobicity is 90%, 400 nm
A treated titanium oxide fine powder XII having a light transmittance of 32% with respect to the light wavelength was obtained.

Comparative Production Example 7 n-C ₁₆ H ₃₃ Si (OCH) as a silane coupling agent
₃ ) Same as in Production Example 1 except that ₃ is used, the average particle size is 0.06 μm, the hydrophobicity is 75%, and the light transmittance is 35% at a light wavelength of 400 nm. A treated titanium oxide fine powder XIII was obtained.

Example 1 Polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 100 parts Phthalocyanine facial department 4 parts Chromium complex of di-tert-butylsalicylic acid 2 parts

The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, cooled, roughly crushed to about 1 to 2 mm with a hammer mill, and then finely crushed with an air jet system. Finely ground. Further, the finely pulverized product obtained is classified to select 2 to 10 μm so as to obtain the particle size distribution of the present invention, and the weight average particle size is 8.2 μm.
Colorant-containing resin particles were obtained.

Cyan toner was prepared by adding 0.5 part of the treated titanium oxide fine powder I to 100 parts of the colorant-containing resin particles.

5 parts of this cyan toner and a copolymer (weight average molecular weight of 200,000) consisting of 75% of methyl methacrylate and 25% of butyl acrylate were used, and the weight average particle diameter was 45 μm.
m (particle size 35 μm or less 4.2%, particle size 35-40 μm
0.5% to a Cu-Zn-Fe-based ferrite carrier having a particle size distribution of 9.5% and a particle size of 74 μm or more and 0.2%).
% Of the coated magnetic carrier to prepare a two-component developer.

Using this developer, the development contrast was set to 300 V in a commercially available plain paper color copying machine (color laser copying machine 500, manufactured by Canon), and 23 ° C./65%.
Imaged below. The image obtained is Macbeth RD9
The reflection density was measured using an SPI filter on a Model 18 (the same applies to the following image density measurement method). The image density was as high as 1.52, and it was clear without any fog. Further, the OHP projection image was also clear and had no dust. Thereafter, 10,000 copies were further made, during which the density fluctuation was as small as 0.1, and the fog and sharpness were equivalent to those at the initial stage. Also under low temperature and low humidity (20 ℃,
Even at 10% RH), when the development contrast was set to 300 V and image formation was performed, the image density was as high as 1.47, suggesting that the present invention was effective in controlling the charge amount under low humidity. ing.

In addition, under high temperature and high humidity (30 ° C./80% RH)
However, when the development contrast was similarly set to 300 V and image formation was performed, the image density was 1.54, which was very stable and a good image was obtained.

23 ° C./60% RH, 20 ° C./10%
No abnormalities were observed in the initial images after being left for 1 month in each of RH and 30 ° C./80% RH environments.

Example 2 A cyan toner was prepared in the same manner as in Example 1 except that the treated titanium oxide fine powder II was used, and a two-component developer was prepared in the same manner as in Example 1. An image drawing test was performed.

In a high-temperature and high-humidity environment (30 ° C./80% RH), the triboelectric charge amount of the toner was slightly decreased and the image density was slightly increased to 1.57 to 1.61, but good results were obtained. It was

Example 3 Except that the treated titanium oxide fine powder III is used,
A cyan toner was prepared in the same manner as in Example 1, a two-component developer was further prepared, and an image was formed in the same manner as in Example 1.

Under a low temperature and low humidity environment (20 ° C./10% RH), the image density was slightly low at 1.40 to 1.45, but good results were obtained.

Comparative Example 1 A cyan toner and a two-component developer were prepared in the same manner as in Example 1 except that the treated titanium oxide fine powder VII prepared in Comparative Production Example 1 was used. Image formation was performed in the same manner as in Example 1.

In a high-temperature and high-humidity environment (30 ° C./80% RH), the triboelectric charge amount of the cyan toner is lowered, so that the image density is increased to 1.70 to 1.75 and fog occurs in the non-image area. did.

Comparative Example 2 Hydrophilic titanium oxide fine powder commercially available as titanium oxide fine powder (P25, manufactured by Nippon Aerosil Co., Ltd .; average particle diameter of about 0.0).
21 μm, BET specific surface area about 50 m ² / g, hydrophobicity 0
%), A cyan toner was prepared in the same manner as in Example 1, and a two-component developer was further prepared.
Image formation was performed in the same manner as in Example 1.

The fluidity of the cyan toner was poor, and the image quality of the toner image was significantly reduced. Also, under high temperature and high humidity environment (30
(° C./80% RH), the triboelectric charge amount of the cyan toner decreased and toner scattering occurred in the copying machine.

Comparative Example 3 Treated Titanium Oxide Fine Powder VIII Prepared in Comparative Production Example 2
A cyan toner was prepared in the same manner as in Example 1 except that was used, and a two-component developer was further prepared, and image formation was performed in the same manner as in Example 1.

The fluidity of the cyan toner deteriorated, and the quality of the toner image deteriorated. Further, when a cyan toner fixed image was formed on an OHP film and projected, the OHP projected image was dark and poor overall.

Comparative Example 4 Comparative treated titanium oxide fine powder XIII prepared in Preparation Example 7
A cyan toner was prepared in the same manner as in Example 1 except that was used, and a two-component developer was further prepared, and image formation was performed in the same manner as in Example 1.

Under a low temperature and low humidity environment (20 ° C./10% RH), the image density was reduced to 1.30 to 1.40 and the reproducibility of the highlight portion was also slightly reduced. Further, when a cyan toner fixed image is formed on the OHP film and projected,
The sharpness of the HP projected image was slightly lower than that in Example 1.

Example 4 A commercially available color copying machine (color laser copying machine 500, manufactured by Canon) was modified as shown in FIG. 1, and 3000 sheets were prepared in the same manner as in Example 1 except that no carrier was used. When images were printed, the image density was 1.46 to 1.53 at 20 ° C / 10% RH, 1.50 to 1.55 at 23 ° C / 65% RH, and 30 ° C / 80% RH. Good results of 1.52 to 1.58 were obtained.

Example 5 Instead of the phthalocyanine facial, C.I. I. Pigment Yellow 17 was used in the same manner as in Example 1 to prepare a yellow color toner. A two-component developer was prepared in the same manner as in Example 1, and an image was formed in the same manner as in Example 1. As a result, a good yellow color toner image was obtained. Good yellow color toner images were obtained in each environment.

Example 6 Instead of the phthalocyanine facial, C.I. I. Solven
0.8 parts of C.t Red 49 and C.I. I. Pigment
A magenta color toner was prepared in the same manner as in Example 1 using 4.2 parts of Red122. A two-component developer was prepared in the same manner as in Example 1, and an image was formed in the same manner as in Example 1, whereby a good magenta color toner image was obtained. In each environment, a good magenta color toner image was obtained.

Example 7 Two-component developer containing cyan color toner prepared in Example 1, two-component developer containing yellow color toner prepared in Example 5, and magenta color prepared in Example 6 A two-component developer containing toner was introduced into a plain paper full-color copying machine (CLC500, manufactured by Canon),
When each color toner was imaged under the same conditions as in Example 1 to form a full-color image, a full-color image with good color tone was obtained. Furthermore, when images were printed in each environment, good full-color images were obtained.

When a full-color image was formed by using an OHP film instead of plain paper as a transfer material, a full-color fixed image excellent in translucency and excellent in color tone was obtained.
It could be formed on the HP film.

Example 8 Polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 100 parts by weight Phthalocyanine facial composition 4 parts by weight Di-tert-butylsalicylic acid chromium complex 2 parts by weight

The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, cooled, roughly crushed to about 1 to 2 mm with a hammer mill, and then finely crushed with an air jet system. Finely ground. Further, the obtained finely pulverized product was classified to select 2 to 10 μm so as to obtain the particle size distribution of the present invention, to obtain colorant-containing resin particles having a weight average particle size of 8 μm.

To 100 parts by weight of the colorant-containing resin particles, 0.5 parts by weight of the treated titanium oxide fine powder VI, and a particle size of 0.05.
A cyan toner was prepared by combining 0.3 parts by weight of styrene / methyl methacrylate resin particles having two peaks at 5μ and 0.5μ.

A two-component developer was prepared by mixing with a resin-coated magnetic ferrite carrier in the same manner as in Example 1,
Commercially available plain paper color copier (color laser copier 50
(Manufactured by Canon Inc.), the development contrast was set to 300 V, and images were produced at 23 ° C./65% RH. The obtained image had a high density of 1.45 and was clear without any fog. . After that, 10,000 more copies were made, and the density fluctuation during that period was as small as 0.12, and fog and sharpness similar to those at the initial stage were obtained. Further, when the development contrast was set to 300 V and image formation was performed under low temperature and low humidity (20 ° C., 10% RH), the image density was as high as 1.41. It suggests that it was effective.

Further, under high temperature and high humidity (30 ° C./80% RH)
When the development contrast was set to 300 V and image formation was performed, the image density was 1.50, and a very stable and good image was obtained.

23 ° C./60% RH, 20 ° C./10%
No abnormality was observed in the initial images after being left for 1 month in each environment of RH and 30 ° C./80% RH.

Comparative Example 4 Image formation was carried out in the same manner as in Example 8 except that the treated titanium oxide fine powder IX was used in Example 8, and was 30 ° C.
Fog was observed under 80% RH and some toner scattering occurred. This is because the titanium oxide particles were coalesced with each other because the treatment was first performed in the gas phase, not in the water system, and as a result, the fluidity of the toner was impaired.

Comparative Example 5 Image formation was carried out in the same manner as in Example 8 except that the treated titanium oxide fine powder X was used in Example 8, and 30 ° C. /
Fog was observed under 80% RH, and some toner scattering occurred.

Comparative Example 6 Image formation was carried out in the same manner as in Example 8 except that the treated titanium oxide fine powder XI was used in Example 8, but at 20 ° C.
The image density was reduced by about 0.2 under RH of / 10%, and fog was also observed.

Comparative Example 7 Images were produced in the same manner as in Example 8 except that the treated titanium oxide fine powder XII was used in Example 8.
At a temperature of 10 ° C./10% RH, a solid image portion had an image defect that was probably caused by the coalescence of titanium oxide fine particles.

Example 9 Image formation was carried out in the same manner as in Example 8 except that the treated titanium oxide fine powder III was used in Example 8.
Although the image density was increased by 0.05 to 0.1 at a temperature of 80 ° C./80%, the reproduction of highlights was slightly superior, and good results were obtained.

Example 10 Image formation was carried out in the same manner as in Example 1 except that the treated titanium oxide fine powder IV was used in Example 8, and good results were obtained as in Example 2.

[0164]

As described above, when the toner of the present invention is used, a high quality toner image can be provided for a long period of time even under various environments, and a color toner fixed image excellent on an OHP film is formed. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a developing device using a non-magnetic one-component developer.

Claims (9)

(57) [Claims] 1. An electrostatic charge image developing toner comprising at least colorant-containing resin particles and an external additive, wherein the colorant-containing resin particles have a weight average particle diameter (D ₄ ) of 5 to 10 μm. A hydrophobic agent treated with a silane coupling agent, the agent having an average particle diameter of 0.01 to 0.2 μm, a hydrophobicity of 20 to 98%, and a light transmittance of 40% or more for a light wavelength of 400 nm. An electrostatic charge image developing toner, characterized in that it is a fine anatase type titanium oxide fine powder. 2. The hydrophobic titanium oxide fine powder has a hydrophobicity of 2 or less.
The toner for developing an electrostatic charge image according to claim 1, having 0 to 80%. 3. The toner for developing an electrostatic image according to claim 1, wherein the hydrophobic titanium oxide fine powder is subjected to a hydrophobic treatment with a silane coupling agent in an aqueous medium. 4. The toner for developing an electrostatic image according to claim 1, wherein the fine particles of hydrophobic titanium oxide are contained in the toner in an amount of 0.02 to 3% by weight. 5. A color toner having non-magnetic colorant-containing color resin particles and an external additive, wherein the external additive is surface-treated while hydrolyzing a silane coupling agent in an aqueous medium. The electrostatic charge image developing toner according to claim 1, which is a fine powder. 6. The hydrophobic titanium oxide fine powder has an average particle size in the range of 0.2 to 0.02 μ and a hydrophobicity of 20 to 8.
The toner for developing an electrostatic charge image according to claim 5, which is 0%. 7. The hydrophobic titanium oxide fine powder, wherein the external additive is surface-treated while hydrolyzing the silane coupling agent in an aqueous medium and then further surface-treated with the coupling agent in the gas phase. 5. Toner for developing electrostatic image 5. 8. The static additive according to claim 1, wherein the external additive further contains organic resin particles having at least peaks at particle sizes of 0.02 to 0.2 μ and 0.3 to 0.8 μ. Toner for charge image development. 9. A hydrophobic titanium oxide fine powder surface-treated with an external additive while hydrolyzing a silane coupling agent in a water system, and then further surface-treated with the coupling agent in a gas phase, and having a particle size of 0. The toner for developing an electrostatic charge image according to claim 1, further comprising: organic resin particles having at least peaks at 0.02 to 0.2 µ and 0.3 to 0.8 µ.