JP2749192B2 - Electrostatic toner - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a developer for an electrophotographic apparatus, and more particularly to a one-component or two-component toner.

(Prior Art) In recent years, electrophotographic methods, electrostatic recording methods, electrostatic printing methods (hereinafter, referred to as
Electrophotography) has made remarkable progress,
These technologies are based on Electrophotography (RMSchaffert
(Focal press Co., Ltd.), etc., the surface of the photoreceptor is uniformly charged, and then the image corresponding to the original is exposed to extinguish or reduce the charge in the exposed portion, thereby reducing electrostatic latent. An image is formed. Next, the electrostatic latent image is developed by electrostatically adhering a toner for electrostatic charge development (hereinafter sometimes abbreviated as toner) onto the electrostatic latent image, thereby developing the electrostatic latent image. In this case, the amount of toner attached changes in accordance with the amount of charge on the surface of the photoreceptor, and as a result, a toner image having shading is formed. This toner image, depending on the purpose,
The image is transferred to a support such as paper, cloth, or a polymer film, and is generally directly or indirectly heated and fixed on the support surface.

Many methods are known as a developing method in electrophotography, but when roughly classified, a two-component using a mixture of a carrier composed of fine particles (50 to 300 μm) such as iron powder, ferrite, and glass and a toner as a developer is used. There are a developing method and a one-component developing method using a developer consisting of only a toner. In either method, generally, charge is injected into the toner in a triboelectric manner.

Representative examples of the two-component development method include the cascade method described in U.S. Pat.No. 2,618,552 and U.S. Pat.
There is a magnetic brush method described in Japanese Patent No. According to these methods, a relatively stable image can be obtained. However, problems with the two-component developing method have been pointed out, such as contamination of the carrier surface due to toner and the like, deterioration of image quality due to a change in triboelectricity due to a change in the mixing ratio of the carrier and the toner, and the like.

In recent years, full color copiers have been actively developed in response to the growing need to faithfully copy color originals. Generally, in order to obtain a multicolor image of color, the original is exposed using a color separation filter, and the above process is repeated a plurality of times using a color developer of yellow, magenta, cyan, etc., and the toner images are superimposed. A technology for producing a color image has been established. However, as a problem of the present technology, in order to transfer the toner to a transfer material such as paper and obtain a color image, the second color is transferred onto the transfer material on which the first color toner is transferred, and furthermore, It is necessary to perform multiple transfer, in which the third color is transferred, and a transfer drum for holding the transfer material is required, compared to black and white copying in which transfer is usually performed only once. Become large. Also, the size, thickness, and material of the transfer material are limited. Further, the transfer rate of the toner transferred to the second color and the third color in the solid portion decreases, and the desired hue is not reproduced, or the toner of the second color and the third color scatters around the line in the line portion, and the characters are blurred. This causes other problems such as a reduction in sharpness. Therefore, in recent years, an electrophotographic process having a process of forming a plurality of toner images of different colors on a photoreceptor by repeating charging, exposing, and developing a plurality of times, and thereafter simultaneously transferring two or more colors of toner has been developed. An object of the present invention is to provide a toner composition having excellent dispersibility of a coloring substance and a charge control agent, which are toner compositions, without being limited to the one-component and two-component development systems.

(Problems to be Solved by the Invention) The present inventors have conducted intensive studies on the relationship between the structural formula of the compound and the action of preventing the crystal growth and aggregation of the coloring substance. As a result, it was found that a certain compound was added as a toner composition. Thereby, the dispersibility of the coloring substance and the charge controlling agent is improved, the coloring power of the toner is increased, and it is found that the stability of the charge amount is obtained, and the present invention has been achieved. It is to improve the disadvantage.

An object of the present invention is to provide a toner for electrostatic charge development having a high coloring power and a stable charge amount by uniformly and stably dispersing a coloring substance, a charge control agent, a magnetic powder and the like in a toner resin. .

(Means for Solving the Problems) That is, according to the present invention, at least a colorant and a phthalocyanine derivative represented by the following general formula (I) are blended with a binder resin for toner, and the mixture is melted, kneaded, pulverized, and classified. And a toner for electrostatic charge development.

General formula (I) (However, Pc is a phthalocyanine residue which may be substituted by a halogen atom, R ^{1 to} R ⁴ are a hydrogen atom (except when all of R ^{1 to} R ⁴ are hydrogen atoms), a halogen atom, a nitro group,
An amino group, a sulfone group, a carboxyl group, or a lower alkyl group, and n represents an integer of 1 to 4. Examples of the binder resin for toner include styrene-based copolymers such as polystyrene, styrene-butadiene copolymer, and styrene-acrylic copolymer, and polyethylene and ethylene-vinyl acetate-based copolymer, which are conventionally used as toner resins. And ethylene-based copolymers such as ethylene-vinyl alcohol-based copolymers, and thermoplastic resins such as phenolic resins, epoxy resins and polyester resins.

Further, as a coloring agent, a pigment or a dye, specifically, as an inorganic pigment, carbon black, for example, furnace black, channel black, chromate, for example, graphite,
Zinc yellow, etc., ferrocyanide, eg, navy blue, etc., sulfides, eg, silver vermilion, cadmium yellow, zinc sulfide, antimony white, etc., oxides, eg, zinc white, titanium white, red iron oxide, iron black, copper oxide, manganese dioxide, metal Powders such as aluminum powder and bronze powder, and organic pigments include nitroso pigments such as naphthol green B;
Nitro pigments, such as naphthol green Y, naphthol yellow S, lithol fast yellow 2G, etc., azo pigments, such as permanent red 4R, brilliant first scarlet, hansa yellow, lithol red, lake red C, lake red D, brilliant carmine 6B; Permanent red F5R, pigment scarlet 3B, etc., phthalocyanine pigments, such as phthalocyanine blue, phthalocyanine green, etc., basic dye-based pigments, such as rhodamine lake, malachite green lake, methyl violet lake, etc., acidic dye-based pigments, such as peacock blue lake, yuosin lake , Quinoline yellow lake, etc., quinacridone red, quinacridone violet, perylene red, perylene scarlet, Seo isoindolinone yellow,
Dioxazine violet, aniline black, dyes such as organic fluorescent pigments, azo dyes, anthraquinone dyes,
Examples include phthalocyanine dyes, carbonium dyes, quinoimine dyes, methine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone and naphthoquinone dyes, and naphthalimide dyes.

The amount of the colorant used is 0.5 to 10% by weight, more preferably 1 to 7% by weight, based on the weight of the toner.

The following are specific examples of the phthalocyanine derivative used in the present invention.

By adding the phthalocyanine derivative of the present invention, a toner having excellent coloring power can be supplied. The effect of the phthalocyanine derivative can be obtained by adding 0.1 to 20% by weight of the coloring agent used. Further, from an economical point of view, the expected effect can be obtained with an addition amount of preferably 0.1 to 10% by weight.

In addition, the phthalocyanine derivative of the present invention has the same effect with respect to the dispersion of the magnetic powder added when used as a magnetic one-component toner or a weak magnetic toner at the above-mentioned blending amount.

The charge control agents include those classified as dyes and those classified as resins. Also a charge stabilizer,
Some are classified as antistatic agents. Specifically, typical examples of imparting positive chargeability to the toner include a nigrosine-based oil-soluble dye, crystal violet, triphenylamine, and a quaternary ammonium salt. Further, by using a resin in which the amount of acid amide group introduced is adjusted as the copolymer resin constituting the toner, the level of the positive charge amount can be improved. Further, a quaternary ammonium salt or an antistatic agent may be added for stabilizing the charge. Typical examples of imparting negative chargeability include metal complex dyes such as balatin dyes and orazole dyes. Each of the above materials is contained in the toner of the present invention in an amount of 0.
By adding in the range of 5 to 10% by weight, the desired charge amount can be controlled. Of course, the above-mentioned agent, charge stabilizer and antistatic agent can be used alone or in combination of two or more.

By adding a phthalocyanine derivative having the structural formula shown in the present invention, to accelerate the rise of charging,
It also has the effect of improving the stability over time. Generally, the above charge control agent and charge stabilizer are 0.5 to 10% of the toner components.
However, by adding the present phthalocyanine derivative, the expected effect can be obtained.

The toner according to the present invention is a hot roll, a kneader, a binder resin, a colorant, a hot melt kneader such as an extruder,
A phthalocyanine derivative, a charge control agent, a magnetic powder, and the like can be produced by well melting and kneading, followed by mechanical pulverization and classification.

Further, the toner according to the present invention requires addition of silica as an external additive. The purpose of the silica addition is to improve the fluidity of the toner and to control the toner charge amount. If the addition amount is less than 0.05% by weight, there is no effect on fluidity and charge amount control, and if it is more than 2% by weight, the photoreceptor is damaged or silica is filmed on the photoreceptor.
A range of weight% is preferred.

Other external additives to the toner of the present invention, for example, a metal salt of a higher fatty acid typified by a cleaning improver, namely, zinc stearate, a fluorine-based polymer, a photoreceptor surface polishing agent, ie, cerium oxide, strontium titanate, Developing / transfer controlling agents, that is, fine polymer powder such as alumina, tin oxide, molybdenum disulfide, copper oxide, and polymethyl methacrylate can be added to the toner. The addition amount of these functional external additives is 0.05 to 3% by weight based on the toner.
Is preferred.

As a method of adding the above-mentioned silica and various functional external additives to the toner, known mixers, for example, a V-type mixer, a rotary container type mixer such as a turbula mixer, a ribbon type, a screw type, a rotary blade type, etc. Can be appropriately used. The various components may be mixed all at once, or may be mixed in order in consideration of the properties of the toner.

(Examples) Hereinafter, the toner according to the present invention will be described. The method for producing the toner shown in each of the examples and comparative examples is as follows. After thoroughly mixing the material powders shown in the respective examples and comparative examples, the mixture was heated and melted at 150 to 170 ° C., kneaded with a twin screw extruder, cooled and solidified, pulverized and classified to a predetermined average particle diameter. Aligned. Thereafter, a predetermined amount of silica as an external additive and other functional external additives were added, mixed by an Enshell mixer, and passed through a sieve to obtain a sample. For proper evaluation of this sample,
A commercial copier was modified.

Example 1 Polyester resin Tufton NE600 (Kao Corporation) 90 parts Phthalocyanine pigment Lionol Blue FG7350 (Toyo Ink Mfg. Co., Ltd.) 3 parts Wax Hoechst wax PE130 (Hoechst) 4 parts Charge control agent Bontron E-84 (Orient Chemical) Industrial Co., Ltd.) 2.5 parts Phthalocyanine derivative (Structural Formula (b)) 0.5 parts External additive Aerosil R-972 (Nippon Aerosil Co., Ltd.) 0.3 parts External additive Conductive tin oxide T-1 (Mitsui Metals Co., Ltd.) 1 Part Comparative Example 1 Same as Example 1 except that no phthalocyanine derivative was blended.

Example 2 Styrene acrylic resin Perfector 9231 (Hitachi Chemical Co., Ltd.) 74 parts Carbon black Mitsubishi Carbon # 44 (Mitsubishi Chemical Industry Co., Ltd.) 3 parts Magnetic powder KBC-250 (Kanto Denka Kogyo Co., Ltd.) 15 parts Wax Mitsui High Wax 320P (Mitsui Petrochemical Co., Ltd.) 4 parts Charge control agent Aizen Spilon Black TRH (Hodogaya Chemical Co., Ltd.) 2.5 parts Phthalocyanine derivative (Structural formula (c)) 1.5 parts External additive Aerosil R-812 (Nippon Aerosil) 0.2 part External additive FORAFLON 1000VLD (Showa Denko KK) 0.3 part Comparative Example 2 The same procedure as in Example 2 was carried out except that no phthalocyanine derivative was added.

Example 3 Polyester resin Nichigo Polyester HP-301
(Nippon Synthetic Chemical Industry Co., Ltd.) 89.5 parts Pigment Brillint Carmine 6BA (Toyo Ink Manufacturing Co., Ltd.) 3 parts Wax Biscol 550P (Sanyo Chemical Co., Ltd.) 3 parts Charge control agent Bontron P-51 (Orient Chemical Industry Co., Ltd.) 1.5 Part Lunaper 912 (Arakawa Chemical Industry Co., Ltd.) 3 parts Phthalocyanine derivative (Structural formula (c)) 0.1 part External additive Aerosil R-976 (Nippon Aerosil Co., Ltd.) 0.2 part Aluminum Oxide C (Nippon Aerosil Co., Ltd.) 0.02 part Comparative Example 3 Example 3 was the same as Example 3 except that the phthalocyanine derivative was not blended.

 Table 1 summarizes the evaluation results of the examples and comparative examples.

(Effect of the Invention) By adding the compound of the general formula (I) as a toner composition, the dispersibility of the coloring substance and the charge control agent is improved, the coloring power of the toner is increased, and the charge amount is stabilized.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-293870 (JP, A) JP-A-2-294665 (JP, A) JP-A-2-96182 (JP, A) JP-A-58-1983 211161 (JP, A)

Claims (1)

(57) [Claims] An electrostatic charge developing method characterized by blending at least a colorant and a phthalocyanine derivative represented by the following general formula (I) with a binder resin for a toner, and melting, kneading, pulverizing and classifying the mixture. toner. General formula (I) (However, Pc is a phthalocyanine residue which may be substituted by a halogen atom, R ^{1 to} R ⁴ are a hydrogen atom (except when all of R ^{1 to} R ⁴ are hydrogen atoms), a halogen atom, a nitro group,
An amino group, a sulfone group, a carboxyl group, or a lower alkyl group, and n represents an integer of 1 to 4. )