JPH02267565A - Positive chargeable toner - Google Patents

Abstract

PURPOSE:To obtain image quality of a high grade with the positive chargeable toner consisting of a resin, coloring agent and charge control agent and to eliminate the deterioration of the performance thereof with age by incorporating at least the triphenyl methane compd. expressed by specific formula into the charge control agent of the above-mentioned toner at a specific weight ratio of the resin. CONSTITUTION:The triaminotriphenyl methane compd. which can be expressed by the formula is incorporated at 0.05 to 10pts.wt. per 100pts.wt. resin into the charge control agent of the positive chargeable toner consisting of at least the resin, the coloring agent and the charge control agent. In the formula, R denotes 1 to 5C alkyl group. Carbon blacks, Berlin blue, azo systems, etc., are used as the coloring agent and a styrene resin, epoxy resin, etc., are used as the binder resin. The triaminotriphenyl methane compd. is used as the essential component of the charge control agent and the charge control agent is incorporated into the resin at 0.05 to 10pts.wt. per 100pts.wt. resin, by which the developer having the image quality of the high grade and the long life is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positively chargeable toner used in fields such as electrophotography.

(Prior art and problems to be solved) Conventionally, two-component developers consisting of carrier and toner have been used as developers for developing electrostatic images formed on latent image holding surfaces such as electrophotographic photoreceptors. A one-component developer (magnetic toner) that does not require a developer or a carrier is known.

The toner particles constituting these developers are usually colored fine particles containing a resin 1 colorant, a charge control agent, etc. as components. −
In component-based developers, magnetic fine particles such as magnetite having magnetism are used as colorants.

As the resin component in these toners, known resins such as styrene resin, epoxy resin, and polyester resin can be used.

However, developers using positively charged toners containing dyes such as nigrosine as a charge control agent in epoxy resins and polyester resins, which have excellent low temperature fixability and resistance to vinyl chloride staining, are used in plain paper copiers, printers, etc. In practice, the following problems arise when using the device repeatedly.

(a) The inherent chargeability of the resin has OH groups and COOH groups, so it is negatively chargeable.l) The triboelectricity becomes uneven, and furthermore, when mixed with a carrier, the triboelectricity becomes unstable over time. . This inconsistency and instability tend to cause various image defects such as insufficient image density and worsening of fog.

(b) The rate at which developed toner particles are effectively transferred to paper or the like, that is, the transfer efficiency is low, and images tend to be uneven or faded.

(c) Due to the triboelectric charging characteristics that are unstable over time due to mixing with carrier, the resistance of the developer changes and image quality such as gradation and resolution changes.

(Means for Solving the Problems) The present inventors solved the problems of the conventional toner described above,
As a result of intensive studies to obtain a toner that satisfies various required characteristics, we have developed a positive toner that has uniform and stable triboelectric charging properties on each side of the toner particles over time, little change in resistance of the developer, and good transferability. We discovered a chargeable toner and arrived at the present invention.

That is, the gist of the present invention is to provide a toner consisting of at least a resin, a colorant, and a charge control agent, in which the charge control agent contains at least a triaminotriphenylmethane compound represented by the following general formula, based on 700 parts by weight of the resin. 0!
~/Q parts by weight of a positively charged toner.

(R represents an alkyl group having carbon number/-j.) The present invention will be described in detail below.

Various known colorants can be used as the colorant in the toner of the present invention. Examples include inorganic pigments such as carbon black, navy blue, and titanium oxide, organic pigments such as azo pigments and phthalocyanine pigments, and dyes such as anthraquinone pigments. These are contained in the toner in the amount necessary to obtain a clear visible image, but usually 20 parts by weight per 100 parts by weight of the resin.
It is not more than 10 parts by weight, preferably not more than 10 parts by weight.

Known styrene resins, epoxy resins, and polyester resins can be used as the binder resin used in the present invention, and the thermal properties of these resins satisfy the thermal performance required of toners such as fixing properties and storage properties. It is necessary to. These may be crosslinked with a crosslinking agent.

In the present invention, it is particularly preferable to use an epoxy resin and/or a polyester resin having an acid value of jKOH/g9 or less as the binder resin;
When H/WIg is higher, the negative chargeability of the resin itself becomes stronger,
Even if a positive charge control agent is added, sufficient positive charge characteristics cannot be obtained. The toner of the present invention using such a resin has excellent charging properties when combined with the specific charge control agent used, and has excellent resistance to vinyl chloride staining, and in this sense, it is particularly suitable as a toner for printers. be.

The charge control agent used in the present invention uses a triaminotriphenylmethane compound (hereinafter referred to as a TAPM compound) of the general formula described above as an essential component, but other known charge control agents such as nigrosine dyes and quaternary ammonium salts are also used. A charge control agent may be used in combination as long as it does not disturb the charging characteristics of the toner.The amount of charge control agent added is 0.0 parts by weight per 100 parts by weight of the resin.
The amount is 1 to 10 parts by weight, preferably 0.1 to 7 parts by weight.

In addition, the amount of added TAPM compound, which is an essential component, is 1/1 of the resin.
0, θj -70 parts by weight, preferably 0.00 parts by weight. / -j parts by weight.

Other constituent components of the positively chargeable toner of the present invention include:
For example, to improve fixing properties, a low molecular weight olefin polymer, TiO2, A12os +5i02 + Fe5
Various internal or external additives may be included, such as ultrafine powders such as O4, but these should be in amounts that do not interfere with the objectives of the invention.

In addition, the method for manufacturing toner is to combine each of the above ingredients,
They may be mixed and kneaded using a kneader or the like, cooled, then pulverized and classified, and if necessary external addition may be performed using a stirrer or the like. The volume average particle diameter of the toner is preferably 5 to 20 μm as measured by a Coulter counter.

When the toner of the present invention is mixed with a carrier and used as a two-component developer, examples of the carrier include iron powder, ferrite powder, magnetite powder, etc., and any of them can be suitably used. Furthermore, it may be a so-called coated carrier coated with various resins for the purpose of improving durability during continuous use. The average particle size of the carrier is 10
-20θμm is preferred. The mixed weight ratio of carrier and toner is preferably 100', / to /θ.

When the toner of the present invention is used as a one-component developer containing magnetic powder inside, examples of the magnetic powder include fine particles of magnetite powder, ferrite powder, etc., and the amount of magnetic powder in the toner is is lθ to ro% by weight, preferably 20 to 70% by weight.

Hereinafter, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In addition, "parts" in the examples indicate "parts by weight."

Further, the amount of charge was measured using a flow-on charge amount measuring device.

(Example) Toner raw materials were mixed at the following blending ratio, kneaded using an extrusion kneader, cooled, pulverized, and classified. Furthermore, 03-2 parts of hydrophobic silica was added to 700 parts of the classified toner and dispersed by stirring at high speed. At the very least, toner A having an average particle size of 2.3 μm was obtained.

Resin Polyester resin A too
Part coloring agent Mitsubishi carbon plastic, resin #da θ 5
Part (manufactured by Mitsubishi Kasei) Charge control agent Copy Blue PR Part 2 (manufactured by Hoechst) Polyester resin A is a polyester whose main components are bisphenol A and terephthalic acid, and the resin acid value is o, yKO.
H/'n9, and this acid value was measured according to JIs K-69θlK, except that a mixture of toluene and methanol at a volume ratio of 9:1 was used as the solvent for dissolving the sample. is TA where R is a methyl group
It is an MP compound.

Then, "Developer A" was prepared by mixing two parts of toner A and a part of spherical iron powder carrier with an average particle size of 100 μm, and a continuous printing test was performed using a reversal development type non-impact printer equipped with a selenium photoreceptor. I did it.

As a result, there was almost no change in image quality from the initial stage to 10,000 pages, and as shown in Table 1, there was very little variation in the amount of charge.

(Example 2) Resin Polyester resin k 100
The same method as toner A and developer A was used, except that the coloring agent Mitsubishi Carbon Black #gθ was mixed with the charge control agent Copy Blue PR/Pontron N- (manufactured by Orient Chemical Industry ■). Table 1 shows the results of a printing test after adjusting toner B and developer B.

As a result, there was almost no change in image quality from the initial stage to 100,000 pages, and although the amount of charge increased slightly at the beginning, the fluctuation was relatively small.

(Example 3) Resin Polyester resin A I00
Part coloring agent Mitsubishi carbon black nto
S-part charge control agent Copy Blue PRJ, Bontron)-4/0.6 parts (manufactured by Orient Chemical Industry Co., Ltd.) Bontron P-j/ is a quaternary ammonium salt charge control agent.

Table 1 shows the results of a printing test using toner C and developer C prepared in the same manner as toner A and developer A except for the above formulation.

As a result, there was almost no change in image quality from the initial stage to 10,000 pages, and although the amount of charge decreased slightly at the beginning, the fluctuation was relatively small.

(Example 4t) Resin Polyester resin A ioo
Part coloring agent Mitsubishi carbon black @410
J Part Charge Control Agent Copy Blue PR/Part Bontron N-///Part Bontron P-t/ 0. Part J: Toner D and developer were adjusted in the same manner as Toner A and Developer A except for the above formulation, and a printing test was conducted. The results are shown in Table 1.

As a result, there was almost no change in image quality over 100,000 pages from the beginning, and the amount of charge also showed very little variation from the beginning.

(Example resin epoxy resin; Epicoat 1007/
θθ part coloring agent Mitsubishi carbon black @4tOj part charge control agent Copy Blue PR/part Pontron N-090,! Table 1 shows the results of a printing test using toner E and developer E prepared in the same manner as toner A and developer A except for the above formulation.

As a result, there was almost no change in image quality over 100,000 pages from the initial stage, and there was also relatively little variation in the amount of charge from the initial stage.

(Comparative example 1) Resin Polyester resin A I00
Part Coloring Agent Mitsubishi Carbon Black @/IO! Charge control agent Bontron N-/7 2 parts Toner F and developer F were prepared in the same manner as toner A and developer A except for the above formulation, and the results of a printing test are shown in Table 2. .

As a result, although the initial image quality was good, the amount of charge tended to increase over time, and accordingly, the print density gradually decreased and voids also worsened.

(Comparative Example 2) Resin Polyester resin A /θθ
Part Coloring agent: Mitsubishi Carbon Bra, Ri@4tOj Part: Charge control agent: Bontron N-09, Z part: Toner G and developer G were adjusted in the same manner as toner A and developer A, except for the above formulation. The results of the printing test are shown in Table 2.

As a result, although the initial image quality was good, the amount of charge tended to decrease over time, and the capri gradually deteriorated accordingly.

(Comparative Example 3) Resin Polyester resin A ioθ
Part coloring agent Mitsubishi carbon plastic, Rig θ!
Charge control agent Bontron P-j/2
Table 2 shows the results of a printing test using toner H and developer H prepared in the same manner as toner A and developer A except for the above formulation.

As a result, fogging was poor at the beginning, the amount of charge remained at a low level over time, and the image was poor.

Δ: Somewhat good.

: Bad (Effect of the invention) As mentioned above, The positively chargeable toner of the present invention By using high-quality images, And over time A long-life developer with little deterioration in performance can be obtained.

Mitsubishi Chemical Corporation

Claims (1)

[Claims] (1) In a toner comprising at least a resin, a colorant, and a charge control agent, the charge control agent contains at least 0.05 to 10 parts by weight of a triaminotriphenylmethane compound represented by the following general formula per 100 parts by weight of the resin. 1. A positively charged toner characterized by containing: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R represents an alkyl group having 1 to 5 carbon atoms.)