JPH0364763A - color toner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color toner for visualizing electrostatic latent images in image forming methods such as electrophotography and electrostatic recording.

[Prior Art] In recent years, as image forming apparatuses such as electrophotographic color copying machines have become widespread, their uses have expanded to a wide variety of uses, and demands on their image quality have become stricter. 2. Description of the Related Art When copying images such as ordinary photographs, catalogs, and maps, it is required to reproduce them extremely finely and faithfully, without distortion or interruption, down to the smallest detail.

Furthermore, in recent image forming apparatuses such as electrophotographic color copying machines that use digital image signals, the latent image is formed by a collection of dots with a constant potential, and consists of solid areas, halftone areas, and light areas. is expressed by changing the dot density. However, if the toner particles do not adhere to the dots faithfully and the toner particles protrude from the dots, there is a problem that the tonality of the toner image corresponding to the dot density ratio of the digital latent image cannot be obtained. Furthermore, when improving resolution by reducing the dot size in order to improve image quality, it becomes even more difficult to reproduce the latent image formed from minute dots, resulting in poor resolution and gradation, especially in highlighted areas. Images tend to have poor sharpness and lack sharpness.

In addition, although the image quality is good initially, as copying or printing continues, the image quality may deteriorate. This phenomenon is thought to occur because, as copying or printing continues, only toner particles that are easily developed are consumed first, and toner particles that are less developable accumulate and remain in the developing machine.

Up to now, several developers have been proposed for the purpose of improving image quality. Japanese Patent Publication No. 51-3244
The publication proposes a non-magnetic toner intended to improve image quality by regulating particle size distribution. In the toner,
The toner mainly has a particle size of 8 to 12 μm, which is relatively coarse, and according to the studies of the present inventors, it is difficult to uniformly “glue” the latent image with this particle size, and toner with a particle size of 5 μm or less is 30% by number or less, and 20 μm or more is 5% by number or less, which means that the particle size distribution is broad, which also tends to reduce uniformity. In order to form clear images using such coarse toner particles and a toner with a broad particle size distribution, it is necessary to layer the toner particles thickly to fill the gaps between the toner particles and reduce the apparent appearance. There is also the problem that it is necessary to increase the image density, and the amount of toner consumption necessary to achieve a predetermined image density increases.

Mani 1 JP-A-54-72054 proposes a non-magnetic toner having a sharper distribution than the former, but the size of particles of intermediate weight is coarse, 8.5 to 11.0 μm; There is still room for improvement as a high-resolution color toner that faithfully reproduces minute dot latent images.

In JP-A No. 58-129437, the average particle size is 6 to 6.
A non-magnetic toner has been proposed in which the particle size is 10 μm and the maximum number of particles is 5 to 8 μm, but the number of particles of 5 μm or less is as small as 15% by number or less, and images that lack sharpness tend to be formed.

According to the studies conducted by the present inventors, it has been found that toner particles of 5 μm or less have the main function of clearly reproducing minute dots of a latent image and of applying dense toner to the entire latent image. Ta. In particular, in an electrostatic latent image on a photoreceptor, lines of electric force are concentrated, so the electric field strength is higher at the edge portion than inside the image, and the sharpness of the image quality is determined by the quality of toner particles collected at this portion. According to studies conducted by the present inventors, it has been found that the amount of particles of 5 μm or less is effective in solving the problem of highlight gradation.

However, when reducing the toner particle size and increasing the number of toner particles that can withstand 5 cycles, the cohesiveness of the toner itself increases, leading to problems such as a decrease in the mixability of carriers and a decrease in the fluidity of the toner. will occur.

E. Problems to be Solved by the Invention] An object of the present invention is to provide a color toner that solves the above-mentioned problems.

A further object of the present invention is to provide a color toner with high image density, excellent fine line reproducibility, and excellent highlight gradation.

An object of the present invention is to provide a color toner whose performance does not change even after long-term use.

A further object of the present invention is to provide a color toner whose performance does not change due to environmental changes.

Roughness C An object of the present invention is to provide a color toner with excellent transferability.

A further object of the present invention is to provide a color toner that can provide high image density with a small consumption amount.

Furthermore, it is an object of the present invention to improve resolution, highlight gradation %#, even in an image forming apparatus using digital image signals.
The object of the present invention is to provide a color toner that can form a toner image with excellent JI line reproducibility.

[Means and Effects for Solving the Problems] The present invention provides a color toner that can be applied to a developer having non-magnetic colorant-containing resin particles, L-toner made of two or more inorganic oxides, and magnetic particles. (2) The toner has a volume average diameter of 6 to 10 μm, contains 15 to 40 number % of toner particles with a particle size of 5 μm or less, and 0 toner particles with a particle size of 12.7-=-18.0 μM. , 1 to 5.0% by volume, toner particles having a particle size of 16 μm or more are contained at 1.0% by volume or less, and toner particles of 6.35 to 10.1 μm have a particle size distribution satisfying the following formula. and the apparent viscosity of the toner is 100
It is in the range of 104 to 5 x 104 voices at ℃, and 5 x 104% 5 x 104 voices at 90℃, and the endothermic peak value of 05G is 58 to 72 ℃,
■ One of the inorganic oxides is heated, the surface is treated with a silane coupling agent, and then the surface is treated with silicone oil. The specific surface area measured by the BET method after surface treatment is S A and the specific surface area measured by the BET method before surface treatment is S + h. % by weight of the inorganic oxide, and 1f! of the inorganic oxide! ε, the absolute value of the amount of frictional charge with the magnetic particles is 20 μc/g or less, and BE
It is characterized by containing a hydrophilic inorganic oxide B having a specific surface area Sa of 30 to 200 m'/g by the T method in b weight % based on the resin particles, and satisfying the following formula %: 15 Regarding color toner.

The color toner of the present invention containing two or more of the above-mentioned inorganic oxides and having the above-mentioned particle size and phase separation can faithfully reproduce the latent image formed on the photoreceptor, and can reproduce halftone dots and Excellent at reproducing minute dot latent images like digital ones,
Special C Provides an image with excellent gradation and resolution in the highlight area.

Furthermore, it maintains high image quality when copying or printing out, and even in the case of high-density images, it is possible to perform good development with less toner consumption than conventional non-magnetic toner, making it economical and This also has the advantage of reducing the size of the copying machine or printer itself.

In the color toner of the present invention, the number of color toner particles having a particle size of 5 μm or less is 15 to 40% (preferably 20% by number).
~35% by number) is one of the characteristics. Conventionally,
In color toners, color toner particles of 5 pm or less are difficult to control the amount of charge, impair the fluidity of color toners, and are components that cause toner scattering and stain machines, and also cause image fogging. It was believed that it was necessary to actively reduce the number of

However, according to studies conducted by the present inventors, it has been found that color toner particles of about 5 μm are an essential component for forming high-quality images.

For example, a two-component developer having a non-magnetic toner and a carrier having a particle size distribution ranging from 0.5 μm to 30 μm is used to change the surface potential on the photoreceptor, resulting in a large development potential contrast that allows a large number of toner particles to be easily developed. from,
The latent image is developed by changing the potential of the latent image on the photoreceptor, and the developed toner particles on the photoreceptor are collected. When the toner particle size distribution was measured, it was 8.
It has been found that there are many non-magnetic toner particles with a diameter of .mu.m or less, and in particular, there are many non-magnetic toner particles with a diameter of about 5 .mu.m on the latent image of minute dots. In other words, when non-magnetic toner particles with a particle size of about 5 μm are smoothly supplied to develop a latent image on a photoreceptor, an image that is faithful to the latent image, does not protrude from the latent image, and has truly excellent reproducibility. It is something that can be grown.

When the number of non-magnetic toner particles with a particle size of 5 μm or less is less than 15%, there are few non-magnetic toner particles effective for high image quality.
In particular, as the toner is used by continuing to copy or print out, the effective non-magnetic toner particle component decreases, and the balance of the particle size distribution of the non-magnetic toner as shown in the present invention deteriorates, resulting in a gradual decline in image quality. It's going to decline. In addition, if it exceeds 40% by number, non-magnetic toner particles tend to aggregate with each other, resulting in toner agglomerates larger than the original particle size, resulting in rough image quality and reduced resolution.
Or, the density difference between the edge part and the inside of the latent image becomes large,
The image tends to look hollow.

Further, in the non-magnetic toner of the present invention, 12.7 to 1
One feature is that particles in the range of 6.0 μι constitute 0.1 to 5.0 volume % (preferably 0.2 to 3.0 volume %).

This is related to the necessity of the presence of non-magnetic toner particles with a particle size of about 5 μm as mentioned above, but it is true that non-magnetic toner particles with a particle size of 5 μm or less can faithfully form the latent image of minute dots. Although it has the ability to reproduce toner particles, it itself has a fairly high cohesiveness, which may impair its fluidity as a non-magnetic toner.

The present inventors attempted to improve the fluidity by adding two or more of the above-mentioned inorganic oxides for the purpose of improving the fluidity, but adding the inorganic additives alone was insufficient to improve the image density. It was confirmed that the conditions for satisfying all items such as , toner scattering, and fogging were very narrow. Therefore, the present inventors further investigated the particle size distribution of toner, and found that non-magnetic toner with a particle size of 5 μm or less was 15 to 40 μm.
It was found that by containing 0.1 to 5.0 volume % of toner particles of 12.7 to 16.0μ in addition to the number % of toner particles, the problem of fluidity could be solved and high image quality could be achieved. . That is, toner particles in the range of 1.12.7 to 16.0 μm in weight are compared to non-magnetic toner particles with a size of 5 μm or less.
This is thought to be due to the fluidity being appropriately controlled, and as a result, sharp images with high density and excellent resolution and gradation are provided even when copying or printing is continued.

When the amount is more than 5.0% by volume, image quality deteriorates and more development than necessary occurs, that is, too much toner is applied, leading to an increase in toner consumption.

On the other hand, if it is less than 0.1% by volume, image density will decrease due to a decrease in fluidity.

Furthermore, for toner particles of 6.35 to 10.1 μm, their volume % (V), number % (N), and volume average particle diameter (d
Another feature of the color toner of the present invention is that it satisfies the following relationship between (v) and (c).

While studying the state of particle size distribution and development characteristics, the present inventors found that there is a state of particle size distribution most suitable for achieving the purpose as shown by the above formula.

That is, when the particle size distribution is adjusted by the general 18i class wind power, the toner particles of about 54 m, which faithfully reproduce the minute dot latent image, will increase for the L particles with the above-mentioned large value.
The fact that the above value is small can be solved by ε, which indicates that toner particles of about 5 μm are decreasing.

Therefore, there is a range of Tv of 6-10μ days, and
When the above relational expression is clearly satisfied, good toner fluidity and faithful latent image reproducibility are achieved.

In addition, non-magnetic toner particles with a particle size of 16 um or more are 1.0 μm or more.
It is preferable that ε is less than or equal to volume %, and (preferably 1) (is 0.
If it is less than 6% by volume and more than 10% by volume, it will not only hinder the reproduction of fine lines (during transfer, if a coarse toner of 16am or more is applied to the thin layer of toner particles that have been completely developed on the photoreceptor) The presence of protruding particles1] can disrupt the delicate adhesion between the photoreceptor and the transfer paper via the toner layer, causing fluctuations in transfer conditions and resulting in defective transfer images. There are many factors that cause this.

In addition, the volume average diameter of the non-magnetic toner is 6 to 10 μm, preferably 7 to 9 μm, and this value is determined by considering the above-mentioned components and the volume average. If the particle size is less than 6 μm, in applications with a high image area ratio such as graphic images, the amount of toner on the transfer paper is small (and the problem of low image density L is likely to occur; this is due to the latent image It is thought that the same reason as the reason why the internal density decreases at the edge part of Continued deterioration of image quality is likely to occur.

The particle size distribution of toner can be measured by Homo's method,
In the present invention, a Coulter counter is used. In other words, the measuring device is a Coulter counter.
-Interface chair (manufactured by Nikkaki) and CX that output number distribution 1 volume distribution using Type II (manufactured by Coulter)
-1 Connect to a personal computer (Canon),
As the electrolytic solution, a 1% NaCR aqueous solution is prepared using primary sodium chloride. According to the measurement method, the electrolytic aqueous solution ■0 to 1
Add 0.1 to 5 mR of a surfactant, preferably an alkylbenzene sulfonate, to the dispersant and add 2 to 20 mg of the sample to be measured. To suspend the sample, the electrolytic solution was dispersed for about 1 to 3 minutes using an ultrasonic disperser, and then dispersed using the Coulter Counter T^-II Type C using a 100μ aperture tube.
The particle size distribution of particles of ~40μ was measured and the value of the ε roller according to the invention was determined therefrom.

In the present invention, one of the inorganic oxides is added to the colorant-containing resin particles C having the above-mentioned particle size distribution,
After the surface treatment with a silane coupling agent, the surface is treated with silicone oil, and then goes through the process of breaking up the C agglomerates. Contains a% by weight of silica fine powder A that satisfies Sa/S s ; 2; 0.8 when the specific surface area is determined by the BET method before the analysis, and 1 of the inorganic oxides. Calm down, Js of the magnetic particle! The absolute value of the amount of triboelectric charge is 20 μc/g or less and the specific surface area Sa by the BET method is 30 to 200 m”/H, and the resin particles contain bg% of the hydrophilic inorganic oxide B, which is expressed by the following formula: Another feature is that it satisfies the formula %.

As described above, when the toner of the present invention having a uniform particle size distribution is used, the latent image formed by minute dots is faithfully developed, and there is little disturbance in toner adhesion at the edges of the latent image.

However, the toner function of reducing the toner particle size is
, Coulomb force and Van der Waals force are relatively strong compared to gravity and inertial force, so the adhesion force between toners is strong and toner aggregates are likely to form.

Furthermore, when reducing the particle size of toner, the surface area of the toner particles increases, which tends to cause excessive charging.
The structure of Publication No. 37 does not have much importance in preventing toner aggregation and controlling the amount of charge.

In contrast, in the present invention, an improvement has been made by adding an inorganic oxide whose absolute value of triboelectric charge with magnetic particles is 20 μc/g or less. By adding an appropriate amount of this low chargeability inorganic oxide, the charge amount of the toner can be controlled to a suitable level, and furthermore, the adhesion force caused by the charge is weakened, making it difficult to form toner aggregates. By improving the fluidity of the toner, the mixing properties of the developer and the cleaning properties of the toner are also improved.

Further, when the particle size of the toner is reduced, the number of contact points between the toner and the carrier increases, making carrier spent more likely to occur. In this regard, the low chargeability inorganic oxide serves as a good spacer between the carrier and the toner, and has a good effect.

As mentioned above, hydrophilic low-charge inorganic oxides are very effective in preventing toner aggregation or suppressing excessive charging, but these are 3 om'
/g (approx. 40mg) ~200+o'/g (approx. 12
mμ), more preferably 80
m'/g (approximately 25 mμ) ~ 150 m'/g (approximately 15
mμ) range.

That is, a low chargeability inorganic oxide having an ET specific surface area of more than 2 oom''/g has sufficient fluidity, but the disadvantage is that the toner tends to become hydrophilic.

Deterioration appears as phenomena such as a large change in the amount of charge or poor developer fluidity when copying continues with low toner consumption.

Furthermore, with a low chargeability inorganic oxide having an ET specific surface area smaller than 3o1/g, it becomes difficult to obtain sufficient fluidity even when used in combination with other fluidity imparting agents. Furthermore, the dispersion of the fluidity imparting agent tends to be insufficient, resulting in image c fog.

Furthermore, an additional disadvantage of reducing the toner particle size is deterioration of toner transferability. This is thought to be due to the fact that the small particle size toner forms a thin toner layer with respect to the latent image on the photoreceptor, and that the amount of charge is somewhat high.

To solve this problem, in the present invention, the surface is treated with a silane coupling agent, then with silicone oil, and then goes through a step of breaking up the agglomerates. When the specific surface area is S^ and the specific surface area measured by the BET method before surface treatment is Sl, SA/
This problem was solved by using fine silica powder that satisfies SI≧0.8.

S^/S+ represents the degree of crushing treatment, and the closer the value is to 1, the better the crushing is.

In the present invention, a material with SA/Sl of 0.8 or more is used, and more preferably 0.85 or more.

When fine silica powder whose surface is treated with silicone oil is used as a fluidity imparting agent, toner transferability is improved. The viscosity of the silicone oil probably affects the adhesion between toners and between the drum and toner.

However, when surface treatment is performed using only silicone oil, the charging ability becomes too high, and due to the viscosity of the oil, it becomes insufficient to impart fluidity to the toner. Therefore, in the present invention, a two-stage treatment with a silane coupling agent was carried out, and further, collection a of silica fine powder was crushed.

Both treatments work to bring the fine silica powder closer to primary particles than the treatment with oil alone. Therefore, these treatments have made it possible to both improve toner transferability and provide sufficient fluidity.

Furthermore, since the fluidity is improved, good effects of the invention can be obtained in the production process as well. In the case of the present invention, since the toner particle size is small, even if a small amount of coarse particles are included,
This will appear as an adverse effect such as poor transfer. Therefore,
After external addition, the toner is sieved through a fine sieve of 150 mesh or more, preferably 200 mesh or more, to remove fused materials generated during external addition. In order to pass through such a fine sieve, it is necessary to have good fluidity, and the present invention is effective.

Further, this fine silica powder serves to supplement the low chargeability inorganic oxide in terms of chargeability and ability to impart fluidity. Therefore, a sufficient effect cannot be obtained unless the BETET specific surface area is 80 m27g or more.More preferable (I50 m27g
The above is good.

In order to make the present invention more effective, the specific surface area of the hydrophobic inorganic oxide A is SA, and the specific surface area of the wood-philic inorganic oxide B is S^≧SIS, where A and D to the colorant-containing resin particles,
a part by weight each to satisfy the following formula.

A stir-fried rice flour containing b weight % ε, 0.3:i; a + b SS; 1.5 is required.

If (a and b) are not within the above range, the balance between chargeability and fluidity will be unbalanced.

When (a+b)>1.5, the fixing properties of the toner deteriorate, particularly the permeability of traben.

The surface treatment conditions for the silica fine powder used in the present invention are as follows:
After the first reaction, a silane coupling reaction is performed to eliminate the silanol group from the chemical bond center, and then a hydrophobic thin film is formed on the surface with silicone oil as a second reaction.

The IA amount of silicone oil is A/25±A for 100 parts by weight of silicic acid fine powder after silane coupling.
/30 parts by weight (8: specific surface area of silicic acid fine powder) Preferably, it is A/25 /40 parts by weight. At this time, the silane coupling agent has an auxiliary role for the silicone oil to form a homogeneous thin film.
J: It has meaning. In addition, silicone oil is added to determine the chargeability of the fine powder, and has the characteristic that the chargeability changes little due to the surrounding environment. If the processing amount is less than (A/25-A/30) parts by weight, the silicone oil coating will become non-uniform and charging of the developer will be insufficient.

This tendency is particularly noticeable under high humidity, and is accompanied by a decline in image quality.If the amount exceeds (A/25-1-A/30) parts by weight, silicone oil will bind fine powder and cause coagulation. Aggregates are more likely to occur.

As a result, the ability to impart charge to the developer decreases.

The silicic acid fine powder used in the present invention is preferably so-called dry silica produced by vapor phase oxidation of a silicon halide compound.

Alternatively, during production, metal halide compounds such as aluminum chloride and titanium chloride may be oxidized in a vapor phase to form a composite fine powder of silica and metal oxide.

The average primary particle size of the particles is preferably in the range of 0.001 to 2 microns, particularly preferably 0.002 to 0.2 microns.

Examples of the silane coupling agent used in the present invention include, but are not limited to, the general formula % Lucilan and the like.

The silicone oil used in the present invention is represented by a general formula such as dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allyl phenylene, and examples include dimethylsilicone oil, alkyl Examples include modified silicone oil, α-methylstyrene-modified silicone oil, chlorphenyl silicone oil, fluorine-modified silicone oil, but are not limited to C above.

The above silicone oil has a viscosity of 50 to 1 at 25°C.
000 centistokes is preferred.

If it is less than 50 centistocx, it will partially volatilize due to the addition of heat, and the charging characteristics will deteriorate. Moreover, if it exceeds 1000 centistokes, handling becomes difficult.

As a method for the silane coupling treatment, known techniques can be used. Examples include a dry process in which fine silicic acid powder is made into a cloud shape and then reacted with a vaporized silane coupling agent, and a wet process in which fine silicic acid powder is dispersed in a solvent and then reacted with a silane coupling agent dropwise. However, it is not limited to these.

As a method for silicone oil treatment, known techniques can be used. For example, silicic acid fine powder and silicone oil are mixed using a mixer. Examples include, but are not limited to, spraying silicone oil into fine silicic acid powder using a sprayer, or dissolving silicone oil in a solvent and then mixing fine silicic acid powder.

As the crushing means, for example, a device as shown in FIG. 4-1 is used. The additive is introduced from the inlet 13 and enters the inlet chamber 9.
, passes through the impact section 8 between the rotating blade 4 and the liner 7 along the rotating dispersing vane 3, passes through the outlet chamber IO, passes through the return path 11 and the blower 14, and circulates through the same circuit again. After the crushing process is completed, it is taken out from the takeout port 12. Here, if necessary, it is preferable to flow cooling water through the jacket 15 to adjust the ambient temperature. In Figure 4-2, between the blade 4 and the liner 7 11
a is the shortest gap, and the space corresponding to the width of the blade 4 is the impact portion. As the device for crushing, it is also possible to use a zigzag classifier used for toner classification, a pin mill used for crushing, and other improved devices, but the device is not limited to these. .

On the other hand, as hydrophilic inorganic oxides, alumina and titanium oxide are preferable because they can be relatively easily obtained with sharp particle size by a vapor phase method, but there are no particular restrictions on the manufacturing method or crystal structure. The shape of the particles is extremely angular.

Those that become needle-like are not preferred.

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

For example, styrene copolymers such as polystyrene, styrene/butadiene copolymer, styrene/acrylic copolymer, ethylene copolymers such as polyethylene, ethylene/vinyl acetate copolymer, and ethylene/vinyl alcohol copolymer. , phenolic resin, epoxy resin, acrylic phthalate resin, polyamide resin, polyester resin,
Maleic acid resin, etc. Furthermore, there are no particular restrictions on the manufacturing method of any of the resins.

Among these resins, the effects of the present invention are particularly great when a polyester resin having a high negative charging ability is used. That is, although polyester resin has excellent fixing properties and is suitable for color toner, it has a strong negative charging ability and tends to be overcharged. However, when polyester resin is used in the structure of the present invention, the disadvantages are improved and an excellent Toner is obtained.

In particular, the following formula (wherein R is ethylene or propylene group, x,
Each y is an integer of 1 or more, and the average value of x+y is 2 to lO. ) as a diol component, and a carboxylic acid component consisting of a bivalent or higher carboxylic acid, its acid anhydride, or its lower alkyl ester (e.g., fumaric acid, maleic acid, maleic anhydride, phthalate). A polyester resin obtained by cocondensation polymerization with terephthalic acid, trimellitic acid, pyromellitic acid, etc.) is more preferable because it has sharp melting characteristics.

In particular, in terms of light transmittance with traben, the apparent viscosity at 90° C. is 5 X 104 to 5 X 104 voids, preferably 7.5 XIO' to 2 X 104 voids, more preferably 108 to 10 voids. , the apparent viscosity at 100 t is 104 to 5 x 10''' voids, preferably 1,1104 to 3 Color 〇 IP is obtained, and good results are obtained in fixing properties, color mixing properties, and high-temperature offset resistance even when full color toner is applied. Apparent viscosity P at 90°C, h apparent viscosity at 100°C The absolute value of the difference from the multiplicative viscosity P is 2 x 104 < IPR-P21 < 4
A range of X 104 is particularly preferred.

As the coloring agent, widely used dyes and pigments such as phthalocyanine blue, Indakushin blue, peacock blue, permanent red, lake red, rhodamine lake, banza yellow, permanent yellow, and benzidine yellow can be used. In terms of its content,
In order to sensitively reflect the light transmittance of the OHP film, the amount is 12 parts by weight or less, preferably 0.5 to 9 parts by weight, based on the weight of the binder resin.

A charge control agent may be added to the toner according to the present invention in order to stabilize charge characteristics. In this case, a colorless or light-colored charge control agent that does not affect the color tone of the toner is preferred. In the present invention, the present invention becomes more effective when a negatively charged developer is used, and the negative charge control agent at that time may be, for example, a metal complex of an alkyl-substituted salicylic acid (for example, a di-tert. Examples include organic gold R complexes such as a chromium complex of butylsalicylic acid or zinc 21 (body).When a negative charge control agent is added to the toner, it is preferably 0.61 to 10 parts by weight based on 100 parts by weight of the binder resin. 0.5-8
It is best to add a portion of melon.

The magnetic particles used in the present invention include, for example, alloys or oxides of surface-oxidized or unoxidized metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium, and rare earths, as well as their oxides and fluorites. can be used. Moreover, there are no special restrictions on the manufacturing method.

In the present invention, the surfaces of the magnetic particles are coated with a resin or the like. Methods for this include a method in which a coating material such as a resin is dissolved or suspended in a solvent and then adhered to the coated magnetic particles; Any conventionally known method can be applied, such as a method of mixing in the body. In order to stabilize the coating layer, it is preferable that the coating material be dissolved in a solvent.

The material to be coated on the surface of the magnetic particles varies depending on the toner material, but examples include aminoacrylate resin, acrylic resin, a co-electric combination of these resins and styrene resin, silicone resin, polyester resin, polytetrafluorocarbon resin, etc. Ethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, and the like are suitable, but are not necessarily limited thereto.

The most suitable material for the present invention is an acrylic resin or a coelectric combination of these resins and a styrene resin.

The most suitable material for the magnetic particles used in the present invention is
98% or more Cu-Zn-Fe (composition ratio (5-20)
Ferrite particles having a composition of: (5-20) : (30-80)), which can easily smooth the surface, have stable charge imparting ability, and provide a stable coating.

Coating layer 1 of the above compound. The charging characteristics of the magnetic particles may be appropriately determined so as to satisfy the above-mentioned conditions, but generally the total amount is 0.1 to 30% (preferably 0.3 to 30%) based on the magnetic particles of the present invention. 20% by weight).

The coulometric average particle size of these magnetic particles is preferably 35 to 65 pm, preferably 40 to 60 pm. Further, the weight distribution is 26% or less, and the weight distribution is 5% or more, and the weight distribution is 5% or less, and 125% or less,
A good image can be maintained when the thickness of 74 μm or more is 2% or less.

In the present invention, the mixing ratio of the above-mentioned magnetic particles and toner particles is set to 2.0% to 9% by weight, preferably 3% to 8% by weight, in terms of toner concentration in the developer.ε Usually good results are obtained. can get. If the toner concentration is less than 260%, the image density will be low (not practical), and if it is more than 9%, fogging and in-machine scattering will increase, and the useful life of the developer will be shortened.

In addition, in the present invention, a fatty acid metal salt as a lubricant,
For example, fine powder of zinc stearate, aluminum stearate, etc., or fine powder of fluorine-containing polymer, such as fine powder of polytetrafluoroethylene, polyvinylidene fluoride, etc., and fine powder of tetrafluoroethylene-vinylidene fluoride copolymer, or cerium oxide, silicon carbide. An abrasive such as or a conductivity imparting agent such as tin oxide or zinc oxide may be added.

In order to produce the colorant-containing resin particles according to the present invention, the thermoplastic resin may be used as a pigment or dye as a colorant, as necessary.
The charge control agent and other additives are thoroughly mixed using a mixer such as a ball mill, and then melted, kneaded, and kneaded using a thermal mixer such as a heated roll, kneader, or extruder to blend the resins together. Colorant-containing resin particles according to the present invention can be obtained by dispersing or dissolving a pigment or dye in a compatible mixture, cooling and solidifying, and then pulverizing and strictly classifying.

Below, various measuring methods related to the characteristic values of the toner used in the present invention will be described.

(11 Frictional charge measurement: FIG. 1 is an explanatory diagram of the frictional charge amount measuring device.

First, a mixture of particles to be measured and magnetic particles to be used as a developer is prepared. The mixing ratio is 5 parts by weight to 95 parts by weight of magnetic particles in the case of toner and colorant-containing fine particles, and 2 parts by weight to 98 parts by weight of magnetic particles in the case of a fluidity imparting agent. .

Particles to be measured and magnetic particles are placed in a measurement environment and left for 12 hours or more, then placed in a polyethylene bottle, thoroughly mixed and stirred.

Next, a mixture of particles whose triboelectric charge is to be measured and magnetic particles is placed in a metal measurement container 2 with a conductive screen 3 of 500 mesh (the size can be changed as appropriate so that magnetic particles do not pass through) on the bottom. Put on the metal lid 4. The weight of the entire measuring container 2 at this time is measured as L (g). next,
In the suction device 1 (at least the portion in contact with the measurement container 2 is an insulator), suction is performed from the suction port 7 and the air volume control valve 6 is adjusted to set the pressure of the vacuum gauge 5 to 250 mmAq. In this state, suction is performed sufficiently (for about 2 minutes) to remove the toner.

The potential of the electrometer 9 at this time is assumed to be V (volt). Here, 8 is a capacitor, and the capacitance is C (pF). In addition, the weight of the entire measuring container after suction is weighed and is defined as L (g). This triboelectric charge amount T (ILc/g) is calculated as shown in the following formula.

(2) Apparent viscosity measurement: Flow tester CFT-500 type (manufactured by Takasu Seisakusho) is used. The sample is a 60 mesh bath product with a thickness of approximately 1.0 to 1.5
Weigh g. Use a molding machine to make this into 100kg/cm
Pressure is applied for 1 minute with a load of ”.

This pressurized sample is subjected to flow tester measurement under the following conditions at room temperature (temperature: about 20 to 30° C., humidity: 30 to 70% RH) to obtain a humidity-apparent viscosity curve. From the obtained smooth curve, the apparent viscosity at 90° C. and 100° C. is determined, and this is used as the apparent viscosity with respect to the temperature of the sample.

RATE TEMP 6. OD/M (
'C1 minute) SET TEMP 70. O.D.
EG (”C)MAX TEMP
200. ODEGINTERVAL
3. ODEGPREHEAT
300. OSEC (seconds) LOAD
20. OKGF (kg) DIE (DI
A) 1.0 MM (mm
)DIE(LENG) 1.0
MMPLUNGER1, OCM” (cm”) (3
) Endothermic peak value measurement by DSC: In the present invention, differential thermal analysis measuring device (DSC measuring device), DSC
-7 (manufactured by PerkinElmer).

The sample to be measured is accurately weighed in an amount of 5 to 20 mg, preferably 10 mg.

This is placed in an aluminum pan, and using an empty aluminum pan as a reference, measurement is performed at room temperature at a temperature increase rate of 10° C./min within a measurement temperature range of 30° C. to 200° C.

In this temperature raising process, the temperature at which the endothermic peak of the main beak is obtained in the temperature range of 40 to 100°C is defined as the endothermic peak value of the present invention.

(4) Hydrophobization degree measurement: The methanol titration test is an experimental test to confirm the hydrophobization degree of the silica fine powder that fli's the hydrophobized surface.

The "methanol titration test" specified herein to evaluate the degree of hydrophobization of the treated silica fine powder is carried out as follows: 0.2 g of the sample silica fine powder is mixed with a volume of 250
Add to 50 m2 of water in a mff Erlenmeyer flask. Methanol is titrated from the burette until all of the silica is turbid. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed when the entire amount of fine silica powder is suspended in the liquid, and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

[Example] A detailed explanation of the present invention is given below with reference to Examples.
"%" and "part" indicate weight percentage and weight part.

After thoroughly premixing 5 parts of the dynamic gloss salmon yupthalocyanine pigment using a 3-mouth lume mill, melt-knead the pigment with at least ε twice or more,
After cooling, it was coarsely ground to a particle size of about 1-2 mm using a hammer mill. Then, it was pulverized using an air jet type pulverizer. Further, the obtained finely pulverized material was classified using a multi-dividing classifier to obtain a volume average particle size of 8.3 pm, and 25% by number of 5 parts m or less, 91247 μm to 16 μm 1.
6% by volume, more than 16-m obtained substantially resin particles.

The apparent viscosity of the particles was 6.00 x 104 voids at 90°C and 1.1xio' voids at 100°C.

For 100 parts of the above colorant-containing resin particles, 0.5 parts of alumina fine powder whose specific surface area by BET method is 100 m2/g and whose magnetic particles used in this example have a charge amount of -3p, c/g. After dry treatment with methyldisilazane, treatment by spraying with dimethyl silicone oil (KF-96 Shin-Etsu Chemical), and then crushed silica fine powder with the crusher shown in Figure 4-1. (Specific surface area S a 2160 m"/g s S A/S by BET method,
= 160/180 = 0089) After adding 0.5 parts to the outside, the mixture was sieved through a 200-mesh sieve to obtain a cyan toner. The DSC endothermic peak of this toner is 6
The temperature was 7.2°C.

For the sake of curiosity, the classification process using a multi-division classifier is shown in the second stage.
This is schematically shown in FIG. 3, and a cross-sectional perspective view (stereoscopic view) of the multi-division classifier is shown in FIG.

To 6 parts of this cyan toner, 94 parts of Cu-Zn4e-based fluorite particles whose surface was coated with a styrene-methyl methacrylate-difunctional xyl acrylate copolymer were mixed to prepare a developer.

This toner has a charge amount of 6"J in a low-temperature, low-humidity environment (15℃, 10%RH), and a high-temperature, high-humidity environment (32.5℃, 85%RH).
Table 1 shows the amount of charge in H).

Using this developer, a commercially available plain paper copying machine (CLC-1 manufactured by Canon) was modified to have a sleeve circumferential speed of 280 mm/sec, and a running test of 30,000 sheets was carried out at a single temperature and humidity (23℃, 60%R1(), low temperature and low humidity cis°C.

1O%RH), high temperature (32.5℃985%RH)
As a result, high-quality images with sufficient image density were obtained in all environments.

"History" I As a fluidity imparting agent, the specific surface area by BET method is 220
Silica fine powder (S JS, = 220/250=0
．． 88) When the same procedure as in Example 1 was carried out except for using only 0.8 parts of black pepper, the image density decreased from 1.40 to 1.20 after 1000 sheets at low temperature and low humidity.
This became more noticeable as copying progressed.

Example 1 The fluidity imparting agent has a specific surface area of 120 by BET method.
Alumina fine powder 1 with a charge of R-3pc/g, which is m”/g
．． When the same procedure as in Example 1 was carried out except that only 0 copy was used, there was more toner scattering during copying than in Example 1, and the image was fogged. Thereafter, the toner concentration was lowered to 3% and the same procedure was carried out, but toner scattering and fogging were at an unsatisfactory level.

As a ratio 10 fluidity imparting agent, the specific surface area by BET method is 20o
+ 7g charge amount + 5 dec/g titanium oxide 0.5
The specific surface area by the BET method is 250 m"7g,
Silica fine powder (SB/S) was hydrophobized with hexamethyldisilazane, treated with dimethyl silicone oil, and then crushed with a crusher shown in Figure 4-1.

= 250/300 = 0.83) The same procedure as in Example 1 was carried out except that 0.5 part was used in total, but the mixture with the magnetic particles was poor and the frictional charge was not sufficient. Toner particles were generated, and after approximately 500 copies had been copied, fog became noticeable on the image. Furthermore, after that, the control of toner density became unstable, so the running test was discontinued.

Comparison 1 Among the fluidity imparting agents in Example 1, silica fine powder was treated with only dimethyl silicone oil and then crushed (specific surface area = 170 tn2/
g (SA/S, = 170/200 = 0.8
5)) When the same procedure as in Example 1 was carried out except for changing to
It declined and did not recover after that. Further, in the images after 500 sheets, fogging in the background area was noticeable.

Among the fluidity imparting agents in Example 1, fine silica powder was not subjected to crushing treatment (specific surface area = 14
0 m”7g (SA/S, = 140/180
The same procedure as in Example 1 was carried out except that the value was changed to 0.78)). However, during the sieving (200 mesh) performed after external addition in the production process, the toner's permeability was poor.
Therefore, it took about twice as much time as in Example 1. Also,
In the running test, the mixing state of the toner and magnetic particles was poor, and the image had a narrower focal length of about 10 V than in Example 1.

In Example 1, among the flowability imparting agents, fine silica powder was treated with hexamethyldisilazane, then treated with olefin-modified silicone oil (KF-415 Shin-Etsu Chemical), and then No. 4-1 Fine silica powder (specific surface area = 190 m"7g (S A/S
When the same procedure as in Example 1 was carried out except that l=190/200=0.95)), good results were obtained as in Example 1.

In Uragohanyu Example 1, 3 parts of rhodamine pigment was used, and the volume average particle size was 8.55-m5P or less, 17% by number 12.7-16pm, 2.6% by volume 16-m or more
Magenta resin particles having a concentration of 0.1% by volume were obtained.

In addition to the above powder, alumina fine powder with a specific surface area of 95 m"7g by the BET method and a charge amount of substantially O←c/g is added.
．． After surface treatment with 4 parts and dimethyldichlorosilane,
Silica fine powder whose surface was treated with dimethyl silicone oil KF-96 and further subjected to crushing treatment (specific surface area 230 m"7g by BET method (S A / S + = 23
0/260=0.88)) 0.6 parts were added externally to form a magenta toner. The apparent density of this toner is 0.
37g/cm", apparent viscosity at 90℃ 5.7XIO'
The temperature was 5.8 x 104 at 100°C, and the endothermic peak of DSC was 67.8°C.

A developer was prepared by mixing 94 parts of ferrite particles whose surface was coated with a styrene-acrylic acid copolymer to 6 parts of the above toner.

When image formation was carried out in the same manner as in Example 1 using this developer, good results were obtained as in Example 1.

[Effects of the Invention] According to the present invention, an image having high image quality and good color reproducibility can be obtained, and also exhibits good environmental characteristics even under environmental fluctuations.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a frictional charge measuring device. FIG. 2 shows an explanatory diagram of a classification process using a multi-part classification means, FIG. 3 shows a schematic cross-sectional perspective view of the multi-part classification means, and FIG. 4 shows an example of a crusher used in the present invention. shows. 51... Multi-division classification device 61... Coarse powder 82...
・Powder with specified particle size

Claims (3)

[Claims] (1) In a color toner applied to a toner made of non-magnetic colorant-containing resin particles and two or more inorganic oxides and a developer having magnetic particles, [1] the volume average diameter of the toner is 6 to 10 μm. 15 to 40% by number of toner particles having a particle size of 5 μm or less, and 12.7 to 1
Toner particles with a particle size of 6.0 μm are 0.1 to 5.0
% by volume, toner particles having a particle size of 16 μm or more are contained at 1.0% by volume or less, and 6.35 to 10.1 μm.
The toner particles of m have the following formula 9≦V×@d@v/N≦14 [Here, V represents the volume % of toner particles having a particle size of 6.35 to 10.1 μm, and N is 6.35 μm. ~10.1μ
Indicates the number % of toner particles having a particle size of m, @d@v
represents the volume average diameter of all toner particles. ], and the apparent viscosity of the toner is 10^4 to 5x10^5 poise at 100°C, and 5x at 90°C.
It is in the range of 10^4 to 5 x 10^6 poise, the endothermic peak value of DSC is 58 to 72 °C, and [2] as one of the inorganic oxides, it is surface-treated with a silane coupling agent. After that, the surface is treated with silicone oil and goes through a process of breaking up the agglomerates.The specific surface area measured by the BET method after passing through the breaking process is S_A, and the specific surface area measured by the BET method before surface treatment is When Si, S_A/S
Silica fine powder A that satisfies i≧0.8 is contained in a weight percent of the colorant-containing resin particles, and as one of the inorganic oxides, the amount of triboelectrification with the magnetic particles is The absolute value is 20μc/g or less, and the specific surface area S_ by BET method
B contains 30 to 200 m^2/g of hydrophilic inorganic oxide B in b weight % based on the colorant-containing resin particles, and satisfies the following formula S_A≧S_B, 0.3≦a+b≦1.5 A color toner that is characterized by: (2) A claim in which the binder resin of the colorant-containing resin particles is mainly composed of polyester resin, and the hydrophilic inorganic oxide is alumina and/or titanium oxide.
1) Color toner described. (3) The color toner according to claim (1), which is manufactured by a manufacturing method comprising the step of mixing the colorant-containing resin particles and the inorganic oxide and then passing the mixture through a sieve of 150 mesh or more.