JPH0588410A - Electrophotographic blue toner - Google Patents

Abstract

PURPOSE:To improve the dispersing property of a coloring agent and a charge controlling agent and provide a clear blue image by using, as coloring agents, a copper phthalocyanine pigment and inorganic pigments of blue, purple and green together. CONSTITUTION:In an electrophotographic blue toner containing at least a binding resin and a coloring agent, a copper phthalocyanine pigment and inorganic pigments of blue, purple and green are used together as coloring agents. The ratio of copper phthalocyanine pigment to inorganic pigments is 1:19-19:1, preferably 1:10-10:1, and more preferably 1:4-2:3. The blending ratio in the whole coloring agent is 2-20wt.%, and preferably 3-10wt.%, and more preferably 6-8wt.%. As a charge controlling agent, ternary ammonium salts, salicylic metal complex compounds, and metal-containing azo compounds are preferably used, and the ratio contained in the toner is 0.1-2.0wt.%, and preferably 0.4-2.0wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic developer for developing an electric latent image.

[0002]

2. Description of the Related Art Conventionally, electrophotographic methods are described in US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748. This method uses a photoconductive substance to form an electrical latent image on the photoconductor, develops it with toner, and transfers the toner image to paper, etc., if necessary, and then fixes it by heating or solvent vapor. And get a copy.

As a method of visualizing an electric latent image using toner, for example, a magnetic brush method described in US Pat. No. 2,670,063 and US Pat. No. 261 are described.
The cascade developing method described in US Pat. No. 6,552, and the powder cloud method described in US Pat. No. 2,221,776 are known.

As a developer for electrophotography, a pigment or dye such as phthalocyanine blue is used as a coloring agent in resins such as polystyrene, styrene-butadiene copolymer and polyester. After melt kneading, it is ground to 1 to 30 microns. To obtain toner. And the average particle size is almost the same as the particle size of the toner, glass beads up to 500 microns, iron,
Particles of nickel, ferrite or the like, or a carrier obtained by coating these particles with various resins is mixed with the above toner and used as a developer.

[0005]

However, with the above-mentioned developer alone, desired charge amount, charge speed, charge exchange property, charge uniformity, environmental dependence of image quality, developer durability, etc. can be obtained. Since it does not contain inorganic fine powder of low resistance, quaternary ammonium salt, charge control agent such as salicylic acid metal complex compound, etc., it is attempted to improve by adding externally, but the above requirements are not sufficiently satisfied. It was In particular, even if the charge amount is adjusted to a desired value, the charge exchange property is poor, so the amount of toner adhered to the non-image area of the photoconductor is increased, and only fog-prone copies can be obtained, and stains inside the machine occur. Was there.

On the other hand, copper phthalocyanine has been used as a colorant for blue toners for electrophotography, but since it has crystallinity itself, its dispersibility in the binder resin is insufficient, and it is charged when used for a long period of time. However, when the toner is replenished, the charge amount is not uniform, which causes image defects such as fog. Further, a large amount of copper phthalocyanine needs to be internally added in order to obtain a desired coloring power as a blue toner, but a large amount of internal addition has a problem in safety.

Therefore, the present invention eliminates the above-mentioned drawbacks and improves the dispersibility of the coloring agent and the charge control agent in the electrophotographic blue toner, and as a result, the charge amount of the toner is kept uniform and excellent. It has a charge exchange property, and even after adding toner (after toner admix), the charge distribution is sharp, toner adhesion to the non-image area of the photoconductor is extremely small, stains inside the machine are small, and durability is excellent. The present invention aims to provide a toner for electrophotography, which can obtain stable image quality even in copying, and has no safety problem.

[0008]

According to the present invention, in a blue toner for electrophotography containing at least a binder resin and a colorant, a copper phthalocyanine pigment is used as a colorant together with an inorganic pigment such as blue, purple or green. A blue toner for electrophotography, which is characterized in that

In the present invention, it is used in combination with a copper phthalocyanine pigment.
Inorganic pigments are thermally stable and can be heated by the heat of kneading.
No copper phthalocyanine pigment and charge control
If it has the effect of improving the dispersibility of the control agent,
It does not matter what kind. For example, have Al and Si at the same time
Compound, or 6 (6A) group in periodic table, 7
To the (7A), 8 (8), 9 (8), and 10 (8) families
Inorganic pigments containing specified metals, specifically blue
As an inorganic pigment, cobalt blue (CoO.nAl₂
O₃: N = 2 to 3), Cerulean blue (CoO ・ nS)
nO₂-MMgO: n = 1.5-3.5; m = 2-
6), Kuresu (Co₃O_Four+ SiO₂+ Al₂O ₃+ Fe
₂O₃+ NiO + MnO), ultramarine (3NaAlSiO_Four
・ Na₂S₂2 (Na₂O ・ Al₂O₃・ 2Si
O₂) ・ Na₂S₂) Dark blue (Fe_Four Fe (CN)_Five 
3・ NH₂O), as a purple inorganic pigment, cobalt purple
(Deep mouth) (Co ₃(PO_Four)₂; Co₃(PO_Four)₂・
8H₂O), cobalt purple (light mouth) (Co ₃(AsO_Four)
₂; Co₃(AsO_Four)₂・ 8H₂O), manganese purple
(Mn₂(PO_Four)₃; (NH_Four)₂Mn (P₂O₇)
₂), Chrome green (dark blue and
Mixture of yellow lead), zinc green (mixture of zinc yellow and navy blue)
Object), chromium oxide (Cr₂O₃), Viridian (Cr₂
O (OH)_Four), Emerald green (Cu (CH₃C
O₂)₂・ 3CuO (AsO₂)₂) Etc.
You can

Examples of the binder resin for the toner include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene and isobutylene;
Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid Α-Methylene aliphatic monocarboxylic acid esters such as butyl and dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone Examples of the binder resin include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, and styrene-acrylate. Rironitoriru copolymer, styrene ─ butadiene copolymer, styrene ─ maleic anhydride copolymer, polyethylene, polypropylene or the like. Further, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can be mentioned.

[0011]

The present invention can improve the dispersibility of copper phthalocyanine and the charge control agent by using two kinds of copper phthalocyanine and inorganic pigments such as blue, violet and green as the colorant of the toner. The uneven distribution of the colorant and the charge control agent in the toner is prevented, and as a result, the charge amount of the toner can be made uniform, and since the colorant is evenly present on the toner surface, the charge exchange property is improved,
It becomes possible to secure desired chargeability in the admix. The ratio of copper phthalocyanine and inorganic pigment is
1:19 to 19: 1, preferably 1:10 to 1
It is 0: 1, more preferably 1: 4 to 2: 3. And the compounding ratio of the whole colorant is 2 to 20% by weight, preferably 3 to 10% by weight, and more preferably 6 to 8% by weight.

As the charge control agent, it is preferable to use a quaternary ammonium salt, a salicylic acid metal complex compound, a metal-containing azo compound or the like. The ratio contained in the toner is
It is 0.1 to 2.0% by weight, preferably 0.4 to 2.0% by weight.

On the toner surface, TiO ₂ , Al ₂ O ₃ ,
It is preferable to attach at least one or more kinds of inorganic oxide fine particles selected from SnO ₂ and SiO ₂ . The average particle size of these is preferably 0.3 micron or less. In order to attach the inorganic oxide fine particles to the surface of the toner particles, they may be mixed with a Henschel mixer, for example. In this case, the total amount of the inorganic oxide fine particles is 0.1 with respect to the total amount of the toner.
˜5% by weight, preferably 0.5 to 3% by weight.

The carrier of the present invention may be either a magnetic powder dispersion type or a resin coating type. As the resin used for the magnetic powder-dispersed carrier, all the resins exemplified as the binder resin for the toner particles can be used. For example, when Cu-Zn ferrite is used as the core material particles, styrene resin, epoxy resin, silicone resin and the like are preferably used. Further, as the magnetic powder, fine particles of a ferromagnetic material which are usually used can be used, and specific examples thereof include triiron tetraoxide, gamma-iron trioxide, various ferrites, chromium oxide and various metal fine particles. The amount of the magnetic powder compounded is 30 to 95% by weight, preferably 45 to 90% by weight based on the whole carrier.
It is in the range of% by weight. As the resin-coated curia, at least a fluorine-based resin in a core material such as ferrite or iron powder,
A material coated with a silicone resin or the like is used.

[0015]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following explanation, "part"
Represents all "parts by weight".

[Example 1] (Production of toner) Styrene-n-butyl acrylate (85/15) copolymer 89 parts Copper phthalocyanine (CIPig.Blue 15: 3) 1 part Dark blue (Milory blue 671) 4 parts Charge control Agent (Bontron P51, manufactured by Orient Chemical Co., Ltd.) 1 part Low molecular weight polypropylene (Viscole 660P, manufactured by Sanyo Kasei) 5 parts The above components were melt-kneaded, pulverized and classified to obtain blue particles having an average particle diameter of 12 microns. To 100 parts of the particles, 2 parts of titanium dioxide P25 (manufactured by Nippon Aerosil) was added and mixed with a Henschel mixer to obtain toner particles.

(Production of Carrier) Styrene-n-butyl acrylate (80/20) copolymer 24 parts Magnetite (EPT-1000 manufactured by Toda Kogyo) 70 parts Fluororesin (manufactured by Kynar 201 Penwald) 6 parts Pressurized above components Melt kneading with a kneader, pulverization, and classification were performed to obtain carrier particles having an average particle size of 40 μm. (Preparation of developer) Then, 95 parts of the carrier was mixed with 5 parts of the toner by a V-type blender to obtain a developer.

Example 2 A toner was prepared in the same manner as in Example 1 except that the inorganic pigment was changed from dark blue to ultramarine, and a developer was obtained.

[Embodiment 3] The charge control agent is Bontron P5.
A toner was obtained in the same manner as in Example 1 except that the number was changed from 1 to E-84 (produced by Orient Chemical Co., Ltd.). Then, 95 parts of a steel shot carrier was mixed with 5 parts of this toner by a V-type blender to obtain a developer.

Example 4 The charge control agent was Bontron P5.
A toner was prepared in the same manner as in Example 2 except that the toner was changed from 1 to E-84 (manufactured by Orient Chemical Co., Ltd.) to obtain a developer.

Comparative Example 1 A toner and further a developer were obtained in the same manner as in Example 1 except that copper phthalocyanine was omitted from the toner raw material of Example 1.

Comparative Example 2 A toner and a developer were obtained in the same manner as in Example 2 except that copper phthalocyanine was omitted from the toner raw material of Example 2.

Comparative Example 3 A toner and a developer were obtained in the same manner as in Example 3 except that copper phthalocyanine was omitted from the toner raw material of Example 3.

Comparative Example 4 A toner and further a developer were obtained in the same manner as in Example 4 except that copper phthalocyanine was omitted from the toner raw material of Example 4.

[Comparative Example 5] A developer was prepared in the same manner as in Example 1, except that the amount of copper phthalocyanine was changed to 5 parts by weight except for the dark blue of Example 1.

[Continuous Copying Experiment] Regarding the developers obtained in the above-mentioned Examples and Comparative Examples, Able 13 manufactured by Fuji Xerox
The modified copier No. 01 was used to evaluate continuous copying of 10,000 sheets. As shown in Table 1, the blue developers of Examples are
It can be seen that, despite copying a large number of sheets, it is excellent in terms of density maintenance, fog, and stains inside the machine. The copy density was measured with a Macbeth densitometer. Fog is G1 (good)
From G to G5 (evil), it is decided by comparing with a five-step sample. G1 has no fog, G4 has a lot of fog, G
5 indicates very high.

[0027]

[Table 1]

[0028]

INDUSTRIAL APPLICABILITY The present invention can improve the dispersibility of copper phthalocyanine and a charge control agent by using two kinds of copper phthalocyanine and inorganic pigments such as blue, purple and green as a colorant for toner. It is possible to prevent uneven distribution of the colorant and the charge control agent in the toner, and as a result,
The toner charge amount can be made uniform, and since the colorant is evenly present on the toner surface, the charge exchange property is improved, and it becomes possible to secure the desired chargeability in the admix, and a clear blue color is obtained. It became possible to obtain a large number of images.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Egawa 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Fuji Zero Tsux Co., Ltd. Takematsu Office

Claims (1)

[Claims] 1. An electrophotographic blue toner containing at least a binder resin and a colorant, wherein a copper phthalocyanine pigment as a colorant and an inorganic pigment such as blue, purple or green are used in combination. Blue toner.