JP3346129B2 - Electrostatic image developing toner, electrostatic image developer, and image forming method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a toner for developing electrostatic latent images for full color for developing an electrostatic latent image, a full color
And an image forming method using the same.

[0002]

2. Description of the Related Art Conventionally, as a method of visualizing an electrostatic latent image formed on a photoconductive photoreceptor or the like by using a toner in an electrophotographic method, for example, a magnetic method described in US Pat. No. 2,870,063 is disclosed. Brush method, No. 2618552
No. 22.
A powder cloud method and the like described in Japanese Patent No. 21776 are known. As the toner used for these, a mixture of a thermoplastic resin and a colorant is generally used. The toner image formed on the photoconductive photoreceptor or the like by the above method or the like is transferred onto a support such as paper, and is fixed under pressure and / or heat. In recent years, the demand for high image quality of copied images has been increasing, and various improvements have been made for both copying machines and developers. In particular, it is often practiced to improve the image quality by reducing the average particle size of the toner particles.
Although reducing the average particle size of the toner particles is an effective method for improving the image quality, it is difficult to obtain a desired density due to high tribo, and further, the charge per toner particle is reduced. Fogging is likely to occur, and the type of use is restricted. In addition, simply reducing the diameter of only the toner causes a problem that when a toner image is fixed on an image support such as paper, toner particles are buried in gaps between fibers of paper and a desired color cannot be reproduced. May occur. In particular, when a toner is manufactured by a kneading and pulverizing method, there is a problem that as the average particle size is reduced, the cost increases.

[0003] For the purpose of improving the above-mentioned various problems, various toners in which the particle size distribution of toner particles is specified have been proposed. For example, Japanese Patent Application Laid-Open No. Sho 62-103675 discloses an average particle size having a specific particle size distribution of 7 to 14 μm.
m has been proposed.
No. 459 proposes a material having a sharp particle size distribution. By the way, in general, when the particle size distribution becomes broad, there is a tendency that the maintainability of charging is reduced and the so-called life is shortened. This is because toner particles having a large particle diameter, which is advantageous for development, are developed, and toners having a relatively small particle diameter stay in the developing machine for a long time. Therefore, it is desirable to make the toner particle size distribution sharper, but there is a limit due to manufacturing limitations and cost issues. Even in the toners described in the above publications, high-quality images cannot be obtained because the large particle diameter side or the small particle diameter side includes broad toner particles. In the case of the publication, fog is likely to occur due to the inclusion of fine powder having a small particle size,
There is a problem that only an image with poor graininess can be obtained.

[0004] In particular, toner particles having a large particle size affect image quality characteristics other than granularity. In particular, in the low pile height portion, the portion where the large particle diameter toner particles are fixed becomes high gloss, and the portion where the small particle diameter toner particles are fixed becomes low gloss, and micro gloss unevenness occurs. This tendency is remarkable as the diameter of the toner increases.
Further, at the time of transfer, there is a problem that the small particle diameter toner existing near the large particle diameter toner is difficult to be transferred, resulting in micro transfer unevenness and white spots.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems. An object of the present invention is extremely without decreasing the toner size, electrostatic charge for full color using high-quality image toner and electrostatic image developer for full-color it can get with no fog An object of the present invention is to provide an image developer. Another object of the present invention is to provide a full-color electrostatic image developing toner capable of forming a good transfer image and obtaining a high-quality image by faithfully developing the toner on the electrostatic latent image, and a toner therefor. An object of the present invention is to provide a full-color developer for electrostatic images using the same. Still another object of the present invention is to provide an image forming method capable of obtaining a high-quality image.

[0006]

The present inventors have studied to solve the above-mentioned drawbacks in the prior art, and as a result, by controlling the particle size distribution of toner particles to a specific range, the above-mentioned problems have been solved. Was found to be improved, and the present invention was completed.

That is, one of the toners for developing a full-color electrostatic image of the present invention comprises toner particles containing a colorant and a binder resin, and has a volume average particle diameter of 3 to 9 μm. And the particle size distribution satisfies the following formulas (1) and (2). D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (where D16v is the 16% volume average particle calculated from the large particle side of the volume average particle diameter) The diameter, D50v, is the 50% volume average particle diameter calculated from the larger particle side of the volume average particle diameter, D50v
50p represents the 50% number average particle diameter calculated from the large particle side of the number average particle diameter, and D84p represents the 84% number average particle diameter calculated from the large particle side of the number average particle diameter. )

Another one of the toner for developing an electrostatic image for full color of the present invention comprises toner particles containing a colorant and a binder resin and an external additive. 3 to 9 μm, the particle size distribution thereof satisfies the above formulas (1) and (2), and 20% of the external additive having an average particle diameter of 20 nm or more and less than 100 nm with respect to the total surface area of the toner particles. The above, and an external additive having an average particle diameter of 7 nm or more and less than 20 nm covers the toner surface at least 40%, and the total coverage of these two external additives is 60% or more based on the total surface area of the toner. It is characterized by being less than 120%. In the present specification, the total coverage is a value obtained by calculating the coverage by converting the amount of the external additive added. Therefore, the case where the addition amount capable of covering 120% is added based on the conversion amount of the external additive is expressed as a coverage rate of 120%.

One of the developers for full-color electrostatic images of the present invention comprises toner particles containing a colorant and a binder resin and a carrier, and the toner particles have a volume average particle diameter of 3 to 9 μm. And the particle size distribution satisfies the above formulas (1) and (2), and the carrier is resin-coated.

Another one of the full-color developer for an electrostatic image of the present invention is a developer for an electrostatic image comprising toner particles containing a colorant and a binder resin and an external additive and a carrier. The volume average particle diameter of the toner particles is 3 to 9;
μm, and its particle size distribution satisfies the above formulas (1) and (2).
External additives having an average particle diameter of 20 nm or more and less than 100 nm
0% or more of the toner particle surface is coated, and an external additive having an average particle size of 7 nm or more and less than 20 nm is coated on the toner particle surface of 40% or more. The total coverage of these two types of external additives is The carrier is characterized by being 60% or more and less than 120% with respect to the total surface area, and the carrier is coated with a resin.

One of the image forming methods of the present invention is a step of forming a latent image on a latent image holding member, and forming a toner image on the latent image holding member using a developer on a developer carrier. A step of transferring the toner image onto the image support, and a step of fixing the toner image on the image support, wherein the developer is
The toner particles contained in the developer include a colorant and a binder resin, the toner particles have a volume average particle diameter of 3 to 9 μm, and the particle size distribution is represented by the above formula (1). ) And Expression (2) are satisfied. Another one of the image forming methods of the present invention is the above-described image forming method, wherein the developer comprises a resin-coated carrier and toner particles, and the toner particles comprise a colorant and a binder resin. The volume average particle diameter of the particles is 3 to 9 μm, and the particle size distribution satisfies the above formulas (1) and (2). When the toner image on the latent image holding member is transferred onto the image support, the toner image may be indirectly transferred from the latent image holding member using an intermediate transfer member.

Another aspect of the image forming method of the present invention is the image forming method described above, wherein the smoothness (Sp) of the surface of the image support satisfies the following formula (7). Is used. Sp ≧ 5 × TMA ^-3 (7) (where Sp represents the smoothness of the surface of the image support, and TMA represents the toner amount (m) per unit area for obtaining a primary color density of 1.7.
g / cm ² ). )

In these image forming methods, the relationship between the volume average particle diameter (D50v) of the toner particles and the weight (TMA) of the toner adhering to the monochromatic colored portion on the image support is represented by the following formula (3). Is preferred. 0.116 × D50v / 2 ≦ TAM ≦ 0.223 × D50v / 2 (3) (where TAM represents an amount of toner (mg / cm ² ) per unit area to obtain a primary color density of 1.7. , D50v have the same meaning as described above.) Further, the relationship between the volume average particle diameter (D50v) of the toner particles and the content of the colorant (c) in the toner is preferably represented by the following formula (4). . 22 / D50v ≦ c ≦ 43 / D50v (4) (wherein c represents the content of the colorant (% by weight) and D50v
Has the same meaning as described above. Further, in these image forming methods, the melt viscosity of the toner particles preferably satisfies the following formulas (5) and (6). 1 × 10 ⁵ ≦ η (90 ° C.) ≦ 1 × 10 ⁶ (5) 1 × 10 ⁴ ≦ η (100 ° C.) ≦ 1 × 10 ⁵ (6) (where η (90 ° C.) and η (100 ° C.) ) Is the melt viscosity of the toner at 90 ° C. and 100 ° C., respectively (P
a · s). )

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The toner particles in the present invention are mainly composed of a binder resin and a colorant. As the binder resin used, styrene, styrenes such as chlorostyrene, ethylene, propylene, butylene, monoolefins such as isobutylene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl esters such as vinyl butyrate, Of α-methylene aliphatic monocarboxylic acids such as methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples include homopolymers and copolymers of esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone. Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-anhydride. Examples include maleic acid copolymers, polyolefins such as polyethylene and polypropylene, and the like. Further, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can also be used.

Examples of the coloring agent include carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine,
Malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1,
C. I. Pigment Red 122, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Yellow 9
7, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 17, C.I. I. Pigment Blue 1
5: 1, C.I. I. Pigment Blue 15: 3 and the like. Further, in addition to the above components, a charge control agent, a cleaning aid, and a fluidity promoter can be contained as necessary.

The toner particles in the present invention can be obtained by heating and kneading a colorant, a binder resin and other components, pulverizing and classifying. In this case, the toner particles have a volume average particle diameter of 3%. And the particle size distribution is expressed by the following formulas (1) and (2).
It is necessary to satisfy D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) In the present invention, the volume average particle diameter of the toner particles is 3 μm.
If m is smaller than m, the charge amount per toner particle becomes small, and an image with much fog is formed. On the other hand, when the volume average particle diameter is larger than 9 μm, the graininess deteriorates, and an image having a rough image quality is obtained.

It is necessary to control the particle size distribution of the toner particles within the above range in order to improve the image quality. That is, when the particle size distribution D16 / D50 on the large particle diameter side is larger than the range of the above formula (1), the granularity of the toner particles deteriorates, resulting in an image with a rough image quality, and the particle size distribution on the small particle diameter side. When D50 / D84 is larger than 1.45, the image quality is slightly fogged and the graininess tends to be deteriorated. Further, when an external additive is added, the amount of the external additive adhered to the toner particles having the central particle diameter becomes smaller than a desired amount because the external additive adheres more to the toner having a large particle diameter. , Transferability deteriorates.

In order to obtain a high quality image, it is necessary to more faithfully reproduce an electrostatic latent image formed on a latent image holding member such as a photoconductive photosensitive member. , Development, transfer, and fixation, the fidelity of the image gradually deteriorates, and the image quality of the image at the time of transfer significantly deteriorates. Although the detailed mechanism of action is not clear, if the particle size distribution of the toner is broad, scattering of the toner at the time of transfer increases, and particularly, when the toner having a large particle diameter scatters, image deterioration becomes remarkable. In addition, when the particle size distribution on the small particle diameter side is wide, when the external additive is added, the external additive becomes difficult to adhere to the toner particles having the small particle diameter, and as a result, poor transfer is likely to occur. However, if the particle size distribution on the large particle diameter side is controlled within the range of the above equation (1) and the particle size distribution on the small particle diameter side is controlled within the range of the above equation (2), a high quality image can be obtained. That is, by controlling the particle size distribution of the toner particles within the above range, the particle size distribution becomes sharp, and the toner is extremely faithfully arranged on the electrostatic latent image, so that an image quality improving effect can be obtained.

An external additive may be added to the toner of the present invention to coat the surface of the toner particles. The external additives used include TiO ₂ , SiO ₂ , Al ₂ O ₃ , MgO, Cu
O, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , Ba
O, CaO.SiO ₂ , K ₂ O (TiO ₂ ) _n , Al _{2
O 3 · 2SiO 2, CaCO 3} , MgCO 3, BaSO
₄ , MgSO ₄ , MoS ₂ , silicon carbide, boron nitride,
Examples include inorganic fine powder such as carbon black, graphite, and fluorinated graphite; and polymer fine particles such as polycarbonate, polymethyl methacrylate, polystyrene, and polyvinylidene fluoride. These may be used alone or as a mixture of two or more.

When these external additives are used, the average particle size is 20 nm or more and 100 n
m of the external additive covers the toner surface in an amount of 20% or more, and 40% of the external additive having an average particle diameter of 7 nm or more and less than 20 nm.
As described above, the toner surface is coated, and the total coverage of these two types of external additives is preferably 60% or more and less than 120% based on the total surface area of the toner particles. The total surface area of the toner particles is represented by the following equation (8). _{^{Σπd 2 · n x (8)}} ( wherein, d represents the toner particle size, n _x is. Represents the number of toner) The average particle size to the total surface area of the external additive of the toner particles 20
By setting the coverage of 20 nm or more to less than 100 nm to 20% or more, the contact area between the toner and the latent image holding member can be reduced, and stable transferability can be obtained for a long time. In addition, the average particle diameter is 7 nm or more, 20 nm
By making the external additive less than 40% or more, stable fluidity can be obtained for a long period of time. Further, when the coverage of these two types of external additives with respect to the total surface area of the toner particles is 60% or more and less than 120%, comet and filming are less likely to occur, and the granularity is improved, and the long term is achieved. Thus, a stable image can be obtained.

The toner of the present invention can be used as a one-component developer using the toner alone, or can be used as a two-component developer in combination with a carrier. When used as a two-component developer, ferrite, iron oxide powder, magnetic particles such as nickel,
Alternatively, a coated carrier in which these are coated with a resin, a dispersion type carrier in which magnetic powder is dispersed in a binder resin, or the like can be used. However, from the viewpoint of durability, a coated carrier obtained by coating magnetic particles with a resin is preferably used.
In that case, as a resin for coating, a fluorine resin, a silicone resin, or an acrylic resin can be used. The particle size of the carrier is generally 20 to 1
Those having a range of 00 μm are preferably used. In the case of a two-component developer, the mixing ratio between the toner particles and the carrier can be appropriately set, but generally the weight ratio is 1:99 to 1: 1.
A range of 5:85 is preferred.

The image forming method of the present invention comprises the steps of forming a latent image on a latent image carrier such as a photoconductive photoreceptor, and forming a toner on the latent image carrier by using a developer on a developer carrier. The method includes a step of forming an image and a step of transferring the toner image onto an image support, and a one-component developer or a two-component developer containing the toner described above is used as a developer. The toner image transferred onto the image support is fixed. In this case, when an image support such as paper is used as the image support, the surface smoothness (Sp) is expressed by the following equation (7). It is preferable that they be satisfied. Sp ≧ 5 × TMA ^-3 (7) (where Sp represents the smoothness of the surface of the image support, and TMA represents the toner amount (m) per unit area for obtaining a primary color density of 1.7.
g / cm ² ). Particularly preferably, Sp ≧ 10 × TMA ⁻³ .

In the present invention, by the surface smoothness of the image support in the above range, the image quality is improved, especially overlapping color color reproducibility of the time of forming a full color <br/> over image Extremely good, and color unevenness can be suppressed.

In this case, the relationship between the volume average particle diameter (D50v) of the toner particles and the weight (TMA) of the toner adhering to the monochrome colored portion on the image support is preferably represented by the following formula (3). 0.116 × D50v / 2 ≦ TAM ≦ 0.223 × D50v / 2 (3) (where TAM represents an amount of toner (mg / cm ² ) per unit area to obtain a primary color density of 1.7. , D50v have the same meaning as described above.) TMA was 0.116 × D50v / 2 and 0.223 × D50v.
By controlling in the range of / 2, a desired image density can be easily obtained, and a copy can be easily read.

In the present invention, the relationship between the volume average particle diameter (D50v) of the toner particles and the content (c) of the colorant in the toner particles is preferably represented by the following formula (4). 22 / D50v ≦ c ≦ 43 / D50v (4) (wherein c represents the content of the colorant (% by weight) and D50v
Has the same meaning as described above. ) Colorant content (c) of 22 / D50v to 43 / D50v
, The desired image density can be easily obtained and the copy can be easily read.

Further, the melt viscosity η of the toner (90 ° C.)
In the range of 1 × 10 ⁵ to 1 × 10 ⁶ , and the melt viscosity η (100 ° C.) of the toner in the range of 1 × 10 ⁴ to 1 × 10 ⁶
When the content is in the range of 10 ^5, a good image with less color unevenness can be obtained even when an image support having low smoothness is used. Here, the melt viscosity of the toner is a value (Pa · s) measured at each temperature using a flow tester.

Generally, as the diameter of toner particles decreases,
Interaction with the image support may increase. In the case where the image support is an image support such as paper, for example, toner particles enter between the fibers to reduce the density or the gloss.
Therefore, for example, when used in full color, red,
The color reproduction of superimposed colors such as blue and green may be deteriorated. In this case, it is necessary to adjust the smoothness of the surface of the image support so that the toner particles do not mix between fibers such as paper. These problems can be solved by controlling the surface smoothness of the image support to a range satisfying the above-mentioned formula (7) or controlling the melt viscosity of the toner.

In general, the reduction in the size of toner particles is as follows.
There is a tendency that the toner density range usable as a developer is significantly narrowed. That is, preferably, by setting the content of the colorant in the toner to a range satisfying the above formula (4), a desired image density can be obtained even when the amount of toner to be developed is small. There is no problem in mastering it. However, this alone results in an excessively high maximum density of the image, resulting in poor appearance.
Therefore, it is more preferable to set the toner amount per unit area of the highest density portion in a single color in a range that satisfies the expression (3).

[0029]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In the following description, all parts are parts by weight.
Means In measuring the particle size and the particle size distribution, a Coulter Counter TA2 was used. The coverage of the external additive, the total surface area Σπd ² n _x toner particles calculated from the measurement results of the Coulter counter 10
Coating was performed by calculating the addition amount of the external additive so that the target ratio was set to 0%, and the coverage was determined. In measuring the density of an image, X-Rite 404 manufactured by X-Rite is used.
A densitometer was used. Further, the surface smoothness of the image support is J
The measurement was performed according to IS P8119. Here, the higher the Sp value, the higher the smoothness. The melt viscosity of the toner particles was measured using a flow tester (CFT-5, manufactured by Shimadzu).
00C), starting temperature: 80 ° C., preheating: 300 seconds,
Pressure: 0.980665MPa, Die size: 1mmφ
It is a value (Pa · s) measured at each temperature at × 1 mm.

Example 1 (Toner) 95 parts of a polyester-based binder polymer (terephthalic acid / bisphenol A) (Mw: about 10,000) (trade name: NE382, manufactured by Kao Corporation) Colorant (CI Pigment Red 57) 1) 5 parts The above components were kneaded with a biaxial kneader, followed by pulverization and classification to obtain toner particles having a volume average particle diameter (D50) of 7 μm. At this time, D16v / D50v is 1.21, D
50p / D84p was 1.25. 1 part of silica fine particles was added to 100 parts of the obtained toner particles and mixed with a Henschel mixer. Thereafter, the toner was sieved with a sieve having a mesh size of 45 μm. (Carrier) Cu—Zn—Fe core (50 μm) 100 parts Fluorine-containing acrylic polymer 0.5 part The above components were mixed in a kneader and dried to obtain carrier particles having a volume average particle diameter of about 50 μm. (Developer) A magenta developer was prepared by mixing the toner and the carrier at a weight ratio of 10: 100.

Example 2 The coloring agent was C.I. I. Pigment Blue 15: 3 and the particle size distribution of the toner in the pulverizing and classifying step is D16v / D50v.
Was changed to 1.10 and D50p / D84p to 1.35, and a developer was prepared in the same manner as in Example 1. Example 3 The coloring agent was C.I. I. Pigment Yellow 17
In the pulverization and classification step, the volume average particle diameter of the toner is set to 3 μm,
Particle size distribution: D16v / D50v 1.35, D50p / D84p
Was changed to 1.36, and a developer was prepared in the same manner as in Example 1. Example 4 The volume average particle diameter of the toner was set to 5 μm in the pulverizing and classifying step,
Particle size distribution D16v / D50v 1.29, D50p / D84p
A developer was prepared in the same manner as in Example 1, except that was changed to 1.37. Example 5 The volume average particle diameter of the toner was set to 9 μm in the pulverizing and classifying step,
Particle size distribution D16v / D50v 1.10, D50p / D84p
Was changed to 1.20, and a developer was prepared in the same manner as in Example 3.

Comparative Example 1 In the pulverizing and classifying step, the volume average particle diameter of the toner was set to 5 μm.
Particle size distribution: D16v / D50v 1.33, D50p / D84p
Was changed to 1.46 to prepare a developer in the same manner as in Example 1. Comparative Example 2 In the pulverizing and classifying step, the volume average particle diameter of the toner was set to 5 μm.
Particle size distribution: D16v / D50v 1.40, D50p / D84p
Was changed to 1.47, and a developer was prepared in the same manner as in Example 2. Comparative Example 3 A developer was prepared in the same manner as in Example 2 except that the particle size distribution of the toner was changed to D35v / D50v of 1.35 and D50p / D84p to 1.51 in the pulverization and classification step. Comparative Example 4 A developer was prepared in the same manner as in Example 3, except that the particle size distribution of the toner was changed to D40v / D50v of 1.40 and D50p / D84p to 1.50 in the pulverizing and classifying step. Comparative Example 5 In the pulverization and classification step, the volume average particle diameter of the toner was set to 2.5 μm, the particle size distribution was set to D16v / D50v of 1.30, and D50p / D.
A developer was prepared in the same manner as in Example 3, except that 84p was changed to 1.50.

(Test) The developer prepared in Examples 1 to 5 and Comparative Examples 1 to 5 was used in a copying machine (A-color 6).
35, manufactured by Fuji Xerox Co., Ltd.), and a copying operation was performed to evaluate the image. Table 1 shows the results.

[0034]

[Table 1] * 1: and * 2: G1 (good) to G5 (bad)
It was decided by comparing with the sample of 5 stages up to,
Up to G3 is an allowable level. * 3: indicates fog grade after 30 kcV, G1
It is determined by comparing with a sample of five steps from (good) to G5 (bad), and the allowable level is up to G3.

The evaluation criteria in Table 1 are as follows. Granularity is 5 from G1 (good) to G5 (bad).
This is determined by comparing with a sample of the stage, and the level up to G3 is an allowable level. Similarly, for fog, G
It is determined by comparing with a sample of 5 steps from 1 (good) to G5 (bad), and G2 is a level that has fog but has no practical problem, and G3 and later is a level that is noticeable and has a practical problem Represents

As is clear from the above results, the smaller the particle size of the toner, the better the graininess, but the more sensitive it is to fog. Further, in the toner of the comparative example, even if the particle diameter of the toner is reduced due to fog, the effect of improving the granularity is not recognized. It can be seen that the toners of the examples have excellent effects on gloss unevenness, transfer unevenness, durability and fog compared with the toner of the comparative example.

Example 6 (Toner) 95 parts of polyester binder polymer [Ethylene oxide adduct of terephthalic acid (A) / cyclohexanediol (B) / bisphenol A (C) condensate, A: B: C = 50: 20 : 30 (molar ratio), (Mw: 10000, Mw: 3000)] 5 parts of colorant (CI Pigment Red 57: 1) The above components were kneaded with a biaxial kneader, followed by pulverization. By classification, toner particles having a volume average particle diameter (D50) of 7 μm were obtained. At this time, D16v / D50v is 1.21, D
50p / D84p was 1.35. The obtained toner particles are treated with 10% by weight of dimethyldichlorosilane as a first external additive (external additive 1) to be treated with 10% by weight of silica fine particles having an average primary particle diameter of 20 nm to achieve a coverage of 20% based on the total surface area. In addition, as a second external additive (external additive 2), titanium oxide fine particles having an average primary particle diameter of 15 nm treated with 12% by weight of trimethoxydecylsilane so as to have a coverage of 40% with respect to the total surface area. And mixed with a Henschel mixer. Thereafter, the toner was sieved with a sieve having a mesh size of 45 μm. (Carrier) Cu—Zn—Fe core (50 μm) 100 parts Fluorine-containing acrylic polymer 0.5 part The above components were mixed in a kneader and dried to obtain carrier particles having a volume average particle diameter of about 50 μm. (Developer) A magenta developer was prepared by mixing the toner and the carrier at a weight ratio of 10: 100.

Example 7 In Example 6, the external additive 1 was replaced with an average primary particle diameter of 80 nm.
A developer was prepared in the same manner except that the silica fine particles were changed to. Example 8 A developer was prepared in the same manner as in Example 6, except that the coverage of the external additive 2 was changed to 70%. Example 9 In the pulverization and classification step, the toner had a volume average particle diameter D50 of 5
μm, and the particle size distribution is D16 v / D50 v of 1.24, D50
except that p / D84 p is changed so that 1.32 was prepared a developer in the same manner as in Example 6. Example 10 A developer was prepared in the same manner as in Example 9, except that the coverage of the external additive 1 was changed to 50%. Example 11 In Example 9, the external additive 1 was changed to an average primary particle diameter of 80 nm.
The developer was prepared in the same manner except that the silica fine particles were changed to and the coverage of the external additive 2 was changed to 60%. Example 12 In the pulverizing and classifying step, the volume average particle diameter D50 of the toner was set to 3
μm, and the particle size distribution is D16 v / D50 v of 1.23, D50
except that p / D84 p was changed to be 1.35 was prepared a developer in the same manner as in Example 6.

Comparative Example 6 In the pulverizing and classifying step, the volume average particle diameter D50 of the toner was 7
μm, and the particle size distribution is D35 v / D50 v of 1.35, D50
except that p / D84 p was changed to be 1.47 was prepared a developer in the same manner as in Example 6.

The developers prepared in Examples 6 to 12 and Comparative Example 6 were placed in a copying machine (A-color 635, manufactured by Fuji Xerox Co., Ltd.), and a copying operation was performed to evaluate images. Table 2 shows the results.

[0041]

[Table 2]

The evaluation criteria in Table 2 are as follows. Granularity is 5 from G1 (good) to G5 (bad).
This is determined by comparing with a sample of the stage, and the level up to G3 is an allowable level. The transferability (image omission) was also determined by comparing with a sample of five stages from G1 (good) to G5 (bad), and G2 was a level at which there was fog but no problem in practical use , G3 and thereafter represent levels that are noticeably problematic in practice.

As is clear from the above results, the toner of the comparative example is poor in transferability and graininess, but the toner of the example is significantly improved in graininess and transferability.

Example 13 (Toner) 83.4 parts of polyester-based binder polymer [Ethylene oxide adduct of terephthalic acid (A) / cyclohexanediol (B) / bisphenol A (C) condensate, A: B: C = 50 : 20: 30 (molar ratio), (Mw: 10000, Mw: 3500), Tg65 ° C] Colorant (CI Pigment Red 57: 1 wet cake and 30 parts of the polyester-based binder polymer (30 parts by weight of pigment) (Non-aqueous solid content): Colorant mixed at a ratio of 70 parts and subjected to a pigment dispersion treatment by a heating kneader) 16.6 parts (Pigment content: 5.0 parts) The resulting mixture was pulverized and classified to obtain toner particles having a volume average particle diameter (D50) of 7 μm. At this time, D16v / D50v is 1.21, D
50p / D84p was 1.25. At this time, the melt viscosity of the toner is such that η (90 ° C.) is 2 × 10 ⁵ Pa · s, η
(100 ° C.) was 1.5 × 10 ⁴ Pa · s. To 100 parts of the obtained toner particles, silica fine particles having an average primary particle diameter of 40 nm and surface-treated with hexamethylenesilazane are added so as to have a coverage of 20% with respect to the total surface area of the toner, and the surface thereof is trimethoxydecylsilane. The treated silica fine particles having an average primary particle diameter of 20 nm were added so as to have a coverage of 40% based on the total surface area of the toner, and mixed with a Henschel mixer. Thereafter, the toner was sieved with a sieve having a mesh size of 45 μm. (Carrier) Cu—Zn—Fe core (50 μm) 100 parts Fluorine-containing acrylic polymer 0.5 part The above components were mixed in a kneader and dried to obtain carrier particles having a volume average particle diameter of about 50 μm. (Developer) A magenta developer was prepared by mixing the toner and the carrier at a weight ratio of 10: 100. (Development) The above-mentioned developer was transferred to a copying machine (A-color 63).
5, manufactured by Fuji Xerox Co., Ltd.) and developed using a gradation chart. The surface smoothness of the used paper is 50 seconds
c, 100 sec and 500 sec. At this time,
The amount of developed toner per unit area at a density of 1.7 is
It was 0.5 mg / cm ² .

Example 14 (Toner) 80.1 parts of polyester-based binder polymer [terephthalic acid / glycerin / ethylene oxide adduct of bisphenol A / propylene oxide adduct of bisphenol A (molar ratio 50: 5: 20: 25)) Mw: 420,000, Mn: 3,800, Tg: 69 ° C.] Colorant (30 parts of a wet cake of CI Pigment Blue 15: 3 and the above polyester-based binder polymer (non-aqueous solid content of pigment)) : Coloring agent mixed at a ratio of 70 parts and subjected to pigment dispersing treatment by a heating kneader) 19.9 parts (Pigment content: 6.0 parts) The above components are kneaded with a biaxial kneader, followed by pulverization and classification. Thereby, toner particles having a volume average particle diameter (D50) of 7 μm were obtained. The melt viscosity of the toner at this time is η (90
° C) is 1 × 10 ⁶ Pa · s, η (100 ° C) is 8.0 ×
10 ⁴ Pa · s, D16v / D50v is 1.20, D
50p / D84p was 1.40. Other toner,
A carrier and a developer were prepared in the same manner as in Example 13 to prepare a developer and develop. The surface smoothness of the used paper is 50 sec, 100 sec and 500 sec,
At this time, the amount of developed toner per unit area at a density of 1.7 was 0.45 mg / cm ² .

Example 15 When the amount of the colorant was 26.6 parts by weight (the amount of the pigment was 8.0 parts), the melt viscosity of the toner was η (90 ° C.) of 3.0 × 10 ^5.
Pa · s and η (100 ° C.) became 2.0 × 10 ⁴ Pa · s. Other toner, carrier and developer formulas
A developer was prepared and developed in the same manner as in Example 13. Surface smoothness of used paper is 50 sec, 100 sec
c and 500 sec, and the amount of developed toner per unit area at a density of 1.7 at this time is 0.4 mg /
cm ² .

Table 3 shows the results of the tests of Examples 13 to 15 described above.

[Table 3] In Table 3, the image deterioration is micro-gross unevenness or unevenness due to embossing of paper fibers in a fixed image, and is determined by comparing with five-stage samples from G1 (good) to G5 (bad). And up to G3 is an allowable level. The above results also show that the toners of the examples have an excellent effect on the graininess.

[0048]

As described above, the toner for full-color electrostatic image development and the developer for full-color electrostatic image of the present invention have toner particles having a volume average particle diameter of 3 to 9 μm as described above.
And the particle size distribution is calculated according to the above formulas (1) and (2).
By controlling so as to satisfy the following, the particle size distribution, particularly, the particle size distribution of the toner particles on the large particle diameter side becomes sharp, as a result, less gloss unevenness, transfer unevenness, durability, good granularity, In addition, high image quality without fog
A full-color image can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideyuki Akagi 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Kazuya Furuta 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72 ) Inventor Koji Fukushima 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Masahiro Takagi 1600 Takematsu, Minami-Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. 1600 Takematsu Fuji Xerox Co., Ltd. (72) Inventor Satoru Ishigaki 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Michio Take Inventor 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox (72) Inventor Yuka Ishihara No. 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (56) References JP-A-2-287458 (JP, A) JP-A-6-258862 (JP, A) JP-A-3-1644753 (JP, A) JP-A-3-203749 (JP, A) JP-A-7-110602 (JP, A) JP-A-62-157051 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08 G03G 9 / 113

Claims (16)

(57) [Claims] 1. A toner comprising toner particles containing a colorant and a binder resin, wherein the volume average particle diameter of the toner particles is 3 to 9 μm, and the particle size distribution is represented by the following formulas (1) and (2). A toner for developing electrostatic images for full color , characterized by satisfying the following. D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (where D16v is the 16% volume average particle calculated from the large particle side of the volume average particle diameter) The diameter, D50v, is the 50% volume average particle diameter calculated from the larger particle side of the volume average particle diameter, D50v
50p represents the 50% number average particle diameter calculated from the large particle side of the number average particle diameter, and D84p represents the 84% number average particle diameter calculated from the large particle side of the number average particle diameter. ) 2. An external additive comprising toner particles containing a colorant and a binder resin, wherein the volume average particle diameter of the toner particles is 3 to 9 μm, and the particle size distribution of the toner particles is represented by the following formula (1): An external additive that satisfies the formula (2) and has an average particle diameter of 20 nm or more and less than 100 nm with respect to the total surface area of the toner particles covers 20% or more of the toner particle surface, and has an average particle diameter of 7 nm or more and less than 20 nm. An external additive covers the toner particle surface by 40% or more, and the total coverage of these two types of external additives is 60% or more and less than 120% based on the total surface area of the toner particles. For full color
For developing electrostatic images. D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (wherein, D16v, D50v, D50p and D84p have the same meaning as described above.) 3. An electrostatic image developer comprising toner particles containing a colorant and a binder resin and a carrier, wherein the toner particles have a volume average particle diameter of 3 to 9 μm and a particle size distribution of: A developer for a full-color electrostatic image, which satisfies the formulas (1) and (2), and wherein the carrier is coated with a resin. D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (wherein, D16v, D50v, D50p and D84p have the same meaning as described above.) 4. An electrostatic image developer comprising a toner particle containing a colorant and a binder resin and an external additive and a carrier, wherein the volume average particle diameter of the toner particles is 3 to 9
μm, and the particle size distribution satisfies the following formulas (1) and (2).
External additives having an average particle diameter of 20 nm or more and less than 100 nm
0% or more of the toner particle surface is coated, and an external additive having an average particle size of 7 nm or more and less than 20 nm is coated on the toner particle surface of 40% or more. The total coverage of these two types of external additives is A developer for a full-color electrostatic image, which is 60% or more and less than 120% of the total surface area, and wherein the carrier is coated with a resin. D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (wherein, D16v, D50v, D50p and D84p have the same meaning as described above.) 5. A step of forming a latent image on a latent image holding member, a step of forming a toner image on the latent image holding member using a developer on a developer carrier, and a step of forming the toner image on an image supporting member. step of transferring the above, in an image forming method having the step of fixing the toner image on the image bearing member, der those developer for full color
Thus, the toner particles contained in the developer are composed of a colorant and a binder resin, the volume average particle diameter of the toner particles is 3 to 9 μm, and the particle size distribution is represented by the following formula (1) and formula (1). An image forming method which satisfies (2). D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (wherein, D16v, D50v, D50p and D84p have the same meaning as described above.) 6. A step of forming a latent image on a latent image holding member, a step of forming a toner image on the latent image holding member using a developer on a developer carrying member, and a step of forming the toner image on an image supporting member. step of transferring the above, in an image forming method having the step of fixing the toner image on the image bearing member, the developer is a resin-coated carrier and toner particles, and that the toner particles Do more with a colorant and a binder resin An image for full color , wherein the volume average particle diameter of the toner particles is 3 to 9 μm and the particle size distribution satisfies the following formulas (1) and (2). Forming method. D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (wherein, D16v, D50v, D50p and D84p have the same meaning as described above.) 7. The volume average particle diameter (D50v) of the toner particles.
And the toner weight (TA) adhering to the monochrome colored portion on the image support
The image forming method according to claim 6, wherein the relationship with (M) is represented by the following equation (3). 0.116 × D50v / 2 ≦ TAM ≦ 0.223 × D50v / 2 (3) (where TAM represents an amount of toner (mg / cm ² ) per unit area to obtain a primary color density of 1.7. , D50v are as defined above.) 8. A volume average particle diameter (D50v) of the toner particles.
7. The image forming method according to claim 6, wherein the relationship between the toner content and the colorant content (c) in the toner is represented by the following equation (4). 22 / D50v ≦ c ≦ 43 / D50v (4) (In the formula, c represents the content of the colorant (% by weight) and has the same meaning as described above.) 9. The image forming method according to claim 7, wherein the melt viscosity of the toner particles satisfies the following expressions (5) and (6). 1 × 10 ⁵ ≦ η (90 ° C.) ≦ 1 × 10 ⁶ (5) 1 × 10 ⁴ ≦ η (100 ° C.) ≦ 1 × 10 ⁵ (6) (where η (90 ° C.) and η (100 ° C.) ) Is the melt viscosity of the toner at 90 ° C. and 100 ° C., respectively (P
a · s). ) 10. The melt viscosity of the toner particles is expressed by the following formula (5).
The image forming method according to claim 8, wherein (6) is satisfied. 1 × 10 ⁵ ≦ η (90 ° C.) ≦ 1 × 10 ⁶ (5) 1 × 10 ⁴ ≦ η (100 ° C.) ≦ 1 × 10 ⁵ (6) (where η (90 ° C.) and η (100 ° C.) ) Is the melt viscosity of the toner at 90 ° C. and 100 ° C., respectively (P
a · s). ) 11. A step of forming a latent image on a latent image holding member,
Forming a toner image on the latent image holding member using a developer on a developer carrier, transferring the toner image onto an image support, and fixing the toner image on the image support. The image forming method, wherein the developer is for full color
The toner particles contained in the developer are composed of a colorant and a binder resin, and the volume average particle diameter of the toner particles is 3
To 9 μm, and the particle size distribution is represented by the following formula (1)
And (2), and the smoothness (Sp) of the surface of the image support satisfies the following expression (7). D16v / D50v ≦ 1.475-0.036 × D50v (1) D50p / D84p ≦ 1.45 (2) (where D16v is the 16% volume average particle calculated from the large particle side of the volume average particle diameter) The diameter, D50v, is the 50% volume average particle diameter calculated from the larger particle side of the volume average particle diameter, D50v
50p represents the 50% number average particle diameter calculated from the large particle side of the number average particle diameter, and D84p represents the 84% number average particle diameter calculated from the large particle side of the number average particle diameter. Sp ≧ 5 × TAM ^-3 (7) (where Sp represents the smoothness of the surface of the image support, and TMA represents the amount of toner per unit area (m in which a primary color density of 1.7 is obtained).
g / cm ² ). ) 12. A toner having a volume average particle diameter (D50v) and a toner weight (TA) adhering to a monochrome colored portion on an image support.
The image forming method according to claim 11, wherein the relationship with (M) is represented by the following equation (3). 0.116 × D50v / 2 ≦ TAM ≦ 0.223 × D50v / 2 (3) (where TAM represents an amount of toner (mg / cm ² ) per unit area to obtain a primary color density of 1.7. , D50v are as defined above.) 13. The image forming apparatus according to claim 11, wherein the relationship between the volume average particle diameter (D50v) of the toner and the colorant content (c) in the toner is represented by the following equation (4). Method. 22 / D50v ≦ c ≦ 43 / D50v (4) (wherein c represents the content of the colorant (% by weight) and D50v
Has the same meaning as described above. ) 14. The melt viscosity of the toner particles is expressed by the following formula (5).
The image forming method according to claim 11, wherein (6) is satisfied. 1 × 10 ⁵ ≦ η (90 ° C.) ≦ 1 × 10 ⁶ (5) 1 × 10 ⁴ ≦ η (100 ° C.) ≦ 1 × 10 ⁵ (6) (where η (90 ° C.) and η (100 ° C.) ) Is the melt viscosity of the toner at 90 ° C. and 100 ° C., respectively (P
a · s). ) 15. The melt viscosity of the toner particles is expressed by the following formula (5).
The image forming method according to claim 12, wherein the following conditions are satisfied. 1 × 10 ⁵ ≦ η (90 ° C.) ≦ 1 × 10 ⁶ (5) 1 × 10 ⁴ ≦ η (100 ° C.) ≦ 1 × 10 ⁵ (6) (where η (90 ° C.) and η (100 ° C.) ) Is the melt viscosity of the toner at 90 ° C. and 100 ° C., respectively (P
a · s). ) 16. The image forming method according to claim 11, wherein the developer comprises a resin-coated carrier and toner particles.