JP3039191B2 - Yellow toner and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image, and more particularly, to a dry toner used for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing and the like. > Related to yellow toner and its production method.

[0002]

2. Description of the Related Art Color material characteristics required for a full-color toner include the spectral characteristics of the color material and the heat resistance and light resistance of the color material during toner production. Conventionally, various color materials have been proposed for use in full-color toners. For example, color materials such as cyan, magenta, and yellow have been used in a subtractive color mixture method. Phthalocyanine pigments are used as the cyan coloring material, and lake pigments such as rhodamine lake and carmine 6BC are used as the magenta coloring material, which are excellent in light resistance, color reproducibility and heat resistance. On the other hand, various types of yellow color materials are known.
No. 1 discloses Solvent Yellow (hereinafter referred to as S.I.
Y. 162), and in JP-A-2-207274, S.M. Y. 160, JP-A-2-207273
In the official gazette, S.I. Y. Dyes such as 112,
JP-A-2-210363, JP-A-62-1570
No. 51 and Japanese Patent Application Laid-Open No. 62-255956 disclose C.I. I. Pigment Yellow-12, 13, 14, 1
Disazo pigments such as 6,17 are used. further,
JP-A-3-41472 describes a quinophthalone-based yellow dye, and JP-A-2-210364 and the like also describe a monoazo-based yellow pigment.

[0003]

However, these conventionally proposed yellow coloring materials have a problem when used as a full-color toner component. For example, the dyes described in JP-A-3-41472 have excellent transparency, but are inferior to pigments in heat resistance, color material migration (bleed), and light resistance. Is inferior to the case of pigments in image quality preservation. The disazo pigments described in each of the above publications are superior to dyes in heat resistance, color material transferability (bleed) and light fastness, but are inferior to lake pigments in light fastness and cyan and magenta. , Using yellow 3
The light fastness of color full-color copies is also poor in yellow characteristics, and there has been a problem that the hue changes with prolonged exposure to light. Furthermore, C.I. I. Pigment Yellow-13, 14 and 17 are Dyes and
d Pigments 15 (1991) 1-14, when exposed to a high temperature of 200 ° C. or more, causes thermal decomposition and causes harmful effects such as 3,3-dichlorobenzidine, which is harmful to the human body. It is known to generate substances. In addition, monoazo yellow pigments disclosed in JP-A-2-210364 and the like do not generate harmful substances as described above and are often excellent in light resistance and heat resistance, but have strong hiding power and poor transparency. It was not suitable as a color material for a full-color toner.

[0004] The present invention has been made in view of the above-mentioned problems in the prior art, and its object is to provide:
While satisfying the above-mentioned requirements, that is, the heat resistance and light resistance of the coloring material, the generation of harmful substances (there is no adverse effect on the human body even if thermal decomposition occurs), etc., after fixing the toner. A dry toner with excellent yellow toner fixed image spectral characteristics, transparency and image quality, and excellent toner productivity.
The object is to provide a formula yellow toner. Another object of the present invention is to provide a toner with high color developability, saturation,
Dry to provide good dry yellow toner transparency
It is to provide a method for producing Formula yellow toner.

[0005]

The dry yellow toner of the present invention (hereinafter, simply referred to as "yellow toner") contains a compound represented by the following formula (I), and has a volumetric flatness of the toner.
The uniform particle size d50 is in the range of 2 μm <d50 <10 μm .

Embedded image In the method for producing a yellow toner according to the present invention, the compound represented by the formula (I) is dispersed in advance in a part of a binder resin used for the toner, and the compound is added to the toner so that a desired color material concentration is obtained. It consists of diluting with the binder resin used.

Hereinafter, the present invention will be described in detail. The compound represented by the above formula (I) to be contained in the yellow toner of the present invention is C.I. I. Pigment Yellow 180, which has excellent heat resistance and light resistance, and does not generate harmful substances when heated during fixing. Further, the yellow toner formed by using this is characterized by having excellent transparency, color developability, saturation and the like. Other color materials may be used in combination with the yellow toner of the present invention as long as the preferable effects produced by using the compound represented by the formula (I) are not impaired.

On the other hand, the binder resin used in the yellow toner of the present invention can be selected from a wide range including known ones, but a colorless and transparent resin is preferred. Specifically, styrene-based resins such as styrene or a homopolymer of styrene-substituted product and a copolymer containing styrene or styrene-substituted product, for example, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer Polymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylate copolymer ( For example, styrene-methyl acrylate copolymer,
Styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (for example, Styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α-methyl methacrylate copolymer, And styrene-acrylonitrile-acrylate copolymer, vinyl chloride resin, rosin-modified maleic maleate resin, phenol resin, epoxy resin, saturated or unsaturated polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin Silicone resin, ketone resin,
Ethylene - ethyl acrylate - DOO copolymer, although a xylene resin and polyvinyl butyral resins, particularly preferred resins for use in the present invention, mentioned a styrene resin, saturated or unsaturated polyester resins and epoxy resins be able to. The above binder resins may be used alone or in combination of two or more.

Regarding the physical properties of the binder resin used in the present invention, it is preferable that the binder resin has a glass transition temperature (Tg) of 50 ° C. ≦ Tg in DSC thermal analysis from the viewpoint of storage stability of the toner. When the Tg is lower than 50 ° C., toner adhesion and fusion often occur during the production of the toner, resulting in poor stability of the pulverized particle size or the stability of the classified particle size. Insufficient production stability such as generation of coarse particles. In the present invention, Tg
Means the midpoint glass transition temperature (Tmg) and is defined by JIS
It can be measured by the DSC method of K7122 (heating rate, 10 ° C. per minute).

[0009] The binder resin preferably has a softening point in the range of 80 ° C to 150 ° C. When the softening point of the binder resin is lower than 80 ° C., the strength of the fixed image is low, and the fixing image is easily destroyed when an external force is applied. If the softening point exceeds 150 ° C., the temperature of the heating roll of the fixing machine must be set high during fixing, so that the life of the heating roll is shortened and a large number of continuous copies are taken. In this case, it is difficult to control the temperature of the heating roll, and there is a difference between the color development of the initial copy and the color development of the final copy, and the image quality of the fixed image is not maintained. Incidentally, the measured value of the softening point in the present invention,
It is a value obtained by using a ring and ball automatic softening point tester (TYPE ASP-M4P / Akimine Co., Ltd.).

In the present invention, the amount of the compound represented by the formula (I) is preferably 0.1 to 30 parts by weight, more preferably 2 to 15 parts by weight, per 100 parts by weight of the binder resin.
Parts by weight are desirable. If the addition amount is less than the above range, the coloring effect as a yellow color will be poor, and if it is too large, the melt effect of the toner will increase due to the filler effect of the pigment, and the unfavorable tendency that the fixability will be poor. Show.

In the yellow toner of the present invention, the charge control may be performed by the binder resin or the dye / pigment itself.
If necessary, a charge controlling agent that does not cause a problem in color reproduction may be used in combination. As an example of the charge control agent, 4
Examples thereof include basic electron donating substances such as quaternary ammonium salts, metal chelates, and acidic or electron withdrawing substances such as metal-containing dyes. Among them, the material can be appropriately selected and used so as to obtain a desired charging property. The addition amount of the charge control agent is determined in consideration of conditions such as the chargeability of the binder resin, the addition amount of the colorant, the production method including the dispersion method, and the chargeability of other additives, but is generally determined. The range is preferably 0.1 to 8 parts by weight based on 100 parts by weight of the binder resin. These charge control agents may be mixed and added to the binder resin, or may be contained in the form of adhering or fixing to the surface of the toner particles. Furthermore, in the yellow toner of the present invention, a solid electrolyte, a polymer electrolyte, a charge transfer complex, a conductor such as a metal oxide such as tin oxide, a semiconductor, or a ferroelectric substance, a magnetic substance,
The electrical properties of the toner can be controlled. Others
Auxiliary agents such as various plasticizers and release agents can be added to the yellow toner for the purpose of controlling thermal characteristics, physical characteristics, and the like. These addition amounts may be appropriately set within a range that does not cause a problem in color reproduction.

In the yellow toner of the present invention, the volume average diameter (d50 (Vol)) of the toner particles needs to satisfy the following inequality. 2 μm <d50 (Vol) <10 μm Particularly preferably, the inequality: 3 μm ≦ d50 (Vol) ≦
This is the case where the thickness satisfies the range of 9 μm, whereby a copy having excellent image quality can be obtained. The value of the volume average diameter was measured using a Coulter Counter TA-II (using a 50 μm diameter aperture); manufactured by Coulter Electronics Co., Ltd. As the volume average diameter of the toner particles becomes smaller, the image quality becomes better, but d50 (Vo
l) If <2 μm, the surface area of the toner is increased, so that the toner particles are strongly agglomerated, the toner is not uniformly charged, the image quality of the copy is abnormally deteriorated, and the image cannot be put to practical use. Further, since the aggregation property of the toner is abnormally strong, the cleaning characteristic for the photoconductor is abnormally deteriorated. On the other hand, when the volume average diameter is d50 (Vol)> 10 μm, the dots developed at the time of fixing are enlarged, and the reproduction of the original is not performed faithfully, so that a high quality image cannot be obtained.

Further, in the yellow toner of the present invention, fine powders such as titanium oxide, aluminum oxide, silicon oxide, and zirconium oxide are added to the toner particles to improve the fluidity and chargeability of the toner. Can be. The added amount is based on 100 parts by weight of the toner particles.
0.1 to 10 parts by weight is preferred.

Next, a method for producing the yellow toner of the present invention will be described. Various conventionally used methods for producing toner can be applied to the method for producing toner of the present invention. For example, the compound represented by the above formula (I) can be directly produced by melt-kneading with a binder resin. However, in such a case, the dispersion of the above compound becomes insufficient, resulting in poor transparency, which causes a problem when used as a full-color toner. When the melt-kneaded material is pulverized to a small diameter by a conventionally known jet mill, the amount of the coloring material present in the toner tends to decrease as the pulverized diameter decreases. I Oh, there is a case that caused the problem, also, it is difficult to make a toner with a stable color material amount. Therefore, the yellow toner of the present invention is preferably manufactured as follows. That is, the compound represented by the formula (I) is previously added to a part of the binder resin to be used and dispersed, and then the dispersion is mixed and diluted with the remaining binder resin.

As the step of dispersing the compound represented by the formula (I) in the binder resin in advance, a conventionally known master batch method or flashing method can be used. Regarding the master batch method, see, for example, JP-A-62-280.
The method described in Japanese Patent Application Laid-Open No. 755/755 can be used. As the flushing method, for example, the method described in Japanese Patent Application Laid-Open No. 4-227552 can be used. For example, after the synthesis, a water-containing paste of the above compound obtained by the pigmentation is added to the binder resin, and the mixture is subjected to at least 100
Heat and pressure kneading at a temperature of not less than ° C. may be performed to remove moisture. The ratio of the resin and the coloring material used in the dispersion treatment is such that the amount of the coloring material is 2 parts by weight to 1 part by weight with respect to 100 parts by weight of the resin.
It is preferably in the range of 00 parts by weight.

Next, the obtained pigment dispersion is mixed with a binder resin and diluted to a desired concentration. In that case,
The binder resin to be used may be the same as that used for dispersing the pigment, or another binder resin may be used.

[0017]

The present invention will be described below with reference to examples. In the production examples, examples and comparative examples, “parts” means “parts by weight” unless otherwise specified. The polyester resin, epoxy resin, and styrene-acryl resin used in the following Production Examples, Examples, and Comparative Examples are as follows. Polyester resin (A): A polyester resin obtained from a terephthalic acid / bisphenol A propylene oxide adduct and having physical properties of a softening point (Tm) of 110 ° C and a Tg of 65 ° C. (Mw = 8,800) polyester resin (B): there <br/> polyester resin obtained from terephthalic acid / trimellitic acid / ethylene oxide adduct of bisphenol A, its physical properties are (Tm) = 140 ℃ , Tg = 75
Resin which is ° C. (Mw = 20,000) Epoxy resin (C): Bisphenol A type epoxy resin : (Tm) = 91 ° C., Tg = 53 ° C. (Mw = 8,500) Styrene / acrylic resin (D) (styrene / 2-ethylhexyl) Acrylate (80/20)): (Tm) = 85 ° C., Tg = 55 ° C. (Mw = 20,000
0) Styrene / acrylic resin (E) (styrene / n-butyl acrylate (90/10)) (Tm) = 110 ° C, Tg = 65 ° C (Mw = 30,00
0)

(Example of Dispersion Treatment Pigment) Dispersion treatment pigment (1) The above polyester resin (A) is melted in a pre-heated pressure kneader, and C.I. I. Pigment Yellow 180 was gradually added and the whole amount was added. Thereafter, the mixture was kneaded at 120 ° C. for about 1 hour while applying pressure. After cooling, a hammer mill was used for coarse pulverization to obtain a dispersion-treated pigment having a pigment content of 30% by weight. Dispersion-treated pigment (2) The styrene / acrylic resin (E) is melted in a pre-heated pressure kneader, and C.I. I. Pigment Yellow 180 was gradually added and the whole amount was added. Thereafter, the mixture was kneaded at 120 ° C. for about 1 hour while applying pressure. After cooling, using a hammer mill, coarsely pulverized,
A dispersion-treated pigment having a pigment content of 30% by weight was obtained. Dispersion-treated pigment (3) A dispersion-treated pigment was obtained in the same manner as above, except that the polyester resin (A) in the dispersion-treated pigment (1) was replaced with the polyester resin (B). Dispersion-treated pigment (4) (for comparative example) I. Pigment Yellow 180 instead of C.I. I. Pigment Yellow 15
A dispersion-treated pigment was obtained in the same manner except that No.4 was used.

Example 1 A dispersion-treated pigment (1): 15 parts and a polyester resin (A): 85 parts were melt-kneaded using a pressure kneader, pulverized with a jet pulverizer, and centrifugally classified. To produce a fine powder having a volume average diameter d50 (vol) = 4.3 μm and a volume distribution d90 (vol) / d10 (vol) = 1.3. Furthermore, silica fine powder (Aerosil R81)
2, manufactured by Nippon Aerosil Co., Ltd.)
8% by weight and mixed with a rotary mixer to obtain a yellow toner.

Example 2 8 parts of the dispersion-treated pigment (2) and 92 parts of styrene / acrylic resin (D) were melt-kneaded using a pressure kneader, pulverized by a jet pulverizer, and centrifuged. Classified by a mold classifier, volume average diameter d50 (Vol) = 8.3 μm,
A fine powder having a volume distribution d90 (Vol) / d10 (Vol) = 1.3 was prepared. Furthermore, silica fine powder (Aerosil R
812, manufactured by Nippon Aerosil Co., Ltd.)
1.2 wt%, and mixed by a rotary mixer to obtain a yellow toner.

Example 3 25 parts of the dispersion-treated pigment (1) and 75 parts of the epoxy resin (C) were melt-kneaded using a pressure kneader, pulverized with a jet pulverizer, and centrifugally classified. Classifying by volume machine, volume average diameter d50 (Vol) = 3.5 μm,
A fine powder having a volume distribution d90 (Vol) / d10 (Vol) = 1.3 was prepared. Furthermore, silica fine powder (Aerosil R
812, manufactured by Nippon Aerosil Co., Ltd.)
The mixture was added to 2.3% by weight and mixed with a rotary mixer to obtain a yellow toner.

Example 4 10 parts of the dispersion-treated pigment (3) and 90 parts of the polyester resin (B) were melt-kneaded using a pressure kneader, pulverized with a jet pulverizer, and centrifugally classified. And classified by volume machine, volume average diameter d50 (Vol) = 9.7 μm,
A fine powder having a volume distribution d90 (Vol) / d10 (Vol) = 1.3 was prepared. Furthermore, silica fine powder (Aerosil R
812, manufactured by Nippon Aerosil Co., Ltd.)
1.1 wt% and mixed with a rotary mixer to obtain a yellow toner.

Example 5 A dispersion-treated pigment (1): 20 parts and a styrene / acrylic resin (E): 80 parts were melt-kneaded using a pressure kneader, pulverized by a jet pulverizer, and centrifuged. Classified by a mold classifier, volume average diameter d50 (Vol) = 5.2μ
m, volume distribution d90 (Vol) / d10 (Vol) = 1.3
Was prepared. Further, 1.7% by weight of silica fine powder (Aerosil R812, manufactured by Nippon Aerosil Co., Ltd.) was added to the fine powder and mixed with a rotary mixer to obtain a yellow toner.

Comparative Example 1 A yellow toner was obtained in the same manner as in Example 1 except that the dispersion-treated pigment (1) was replaced with the dispersion-treated pigment (4). Comparative Example 2 C.I. I. Pigment Yellow 154 was not subjected to the preliminary dispersion treatment, and 4.5 parts of this pigment and 95.5 parts of polyester resin (A) were used, and a yellow toner was obtained in the same manner as in Example 1.

Comparative Example 3 C.I. I. Solvent Yellow 162: 10 parts and epoxy resin (Tm = 78 ° C., Tg = 46 ° C.): 90 parts, d50 (Vol) using a jet type pulverizer and classification using an inertia method. = 1.8 µm and volume distribution d90 (Vol) / d10 (Vol) = 1.5. Furthermore, silica fine powder (Aerosil R81)
2. Nippon Aerosil Co., Ltd.)
0% by weight and mixed with a rotary mixer to obtain a yellow toner. (Only in this comparative example, a centrifugal sedimentation type SA-CP4L: manufactured by Shimadzu Corporation was used as a particle size analyzer.)

The yellow toners of Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated as follows.
Using a silicone-coated carrier (average particle size: 45 μm), the toner / carrier ratio was set as shown in Table 1, and mixed with a V blender to obtain each developer. Using these developers, copy samples were prepared using a modified machine of ACOLOR (manufactured by Fuji Xerox) and a modified fixing machine of ACOLOR (manufactured by Fuji Xerox), and the fixability, image quality, and the like were evaluated. The results are shown in Table 1 below.

The evaluation method and evaluation criteria are as follows. (Image quality) A: The image quality is very good. 〇: The image quality is good. Δ: Graininess is slightly inferior. The sharpness of image quality is slightly inferior. ×: The roughness is so severe that it cannot be used. Saturation is generally reduced. (Transparency) The transparency was evaluated by placing a small amount of toner in the center of a glass plate, placing a 7 μm-thick polyimide film on both ends of the glass plate, and heating the glass plate to about 200 ° C. with a hot plate from below. After the toner was in a molten state, another glass plate was placed thereon, a load was applied from above, and the sample was cooled to obtain a 7 μm-thickness transparent evaluation sample. The transparency of this sample was evaluated visually. 〇… Transparent, no turbidity. Δ: Slight turbidity is observed. ×: Opaque, turbidity is noticeable. (Temperature Required for Fixing) An unfixed copy sample of a solid image having a melting point of 100% was prepared and fixed by the above-mentioned modified fixing machine, when the surface glossiness (75 ° -75 °) became 50%. The fixing temperature was set to a temperature required for fixing.

(Bleed Characteristics) As for the bleed characteristics of the color material, a copy sample of a solid image having a halftone dot of 100% was prepared, and a polyvinyl chloride film (30% plasticizer-added product) was formed thereon.
And apply a load of 100 g / cm ² at 50 ° C./90
% RH for 48 hours, and the degree of transfer of the coloring material to the vinyl chloride resin film was evaluated. 〇: good, ×: color transfer occurred. (Toner Storage Property) Toner storage property is as follows. 5 g of toner is placed in a 100 ml beaker, and stored at 45 ° C. and 90% RH.
After standing for 8 hours, the blocking was evaluated. 〇… Good. ×
... Blocking is severe and cannot be used. (Toner Manufacturability) The manufacturability of the toner was evaluated from the difference in grindability, and the following judgment was made. …: Easy to produce, △: poor productivity but manufacturable, ×: unable to produce (Comprehensive evaluation) 〇: very good practicality. Δ: Practical level. ×: Not practical.

[0029]

[Table 1]

[0030]

The yellow toner of the present invention is excellent in heat resistance and weather resistance, does not generate substances harmful to the human body at the time of heat fixing, and has a yellow toner image obtained by fixing. It has high quality, good chroma and transparency, and has excellent image quality.

Claims (2)

(57) [Claims] 1. A binder resin comprising a compound represented by the following formula (I), wherein the volume average particle diameter d50 of the toner is 2 μm <
A dry yellow toner, wherein d50 is in the range of 10 [mu] m . Embedded image 2. The compound represented by the formula (I) according to claim 1, which is subjected to a dispersion treatment in advance using a part of the binder resin, and further diluted with the binder resin. The method for producing a dry yellow toner according to claim 1.