JPS63281170A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To obtain a stable image, irrespective of environmental conditions, by incorporating a specified compound in a resin component in an amount of 0.01-10wt.% of the resin. CONSTITUTION:The resin component contains, in an amount of 0.01-10wt.%, one of the compounds represented by formula I in which R1 is 1-18C alkyl, alkenyl, or aralkyl or aryl optionally substituted on the aromatic ring; each of R2 and R3 is H, halogen, nitro, or the like; each of X and Y is -O-, -COO, -S-, or -NR5-; R5 is H or 1-4C alkyl; M is Cr, Co, or Fe; A is H, Na, K, or the like; and each of l, m, and n is 1 or 2, thus permitting a stable image to be obtained under whatever environmental conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner for developing electrostatic latent images in electrophotography, electrostatic recording, and the like.

[Prior Art] In toner for developing electrostatic images, it is not possible to obtain a certain level of charging performance with the binder resin used alone, so dyes, pigments, etc. are used to control the toner to have the desired triboelectric charging performance. Addition of a charge control substance has been carried out.

Today, the technologies that have been put into practical use in the relevant technical fields are:
Nigrosine-based dyes are used to impart or control positive charge to the toner, and Japanese Patent Publication No. 45-26478 and Japanese Patent Publication No. 55-427 are used to impart or control negative charge to the toner.
Examples include metal-containing compounds shown in Publication No. 52 and the like. In terms of the ability to impart charge to toner particles, these compounds have particularly excellent properties among charge control substances that have been proposed to date, and they also produce images that are sufficient for practical use in conventional copying machines. We were able to provide a toner that gives you the best results.

[Problems to be solved by the invention]However, as electrophotography and electrostatic recording media become more personalized, faster, and more multifunctional, it is necessary to develop a system that has better environmental stability and durability. There is a need for toners that can provide images with higher density, no fogging, high resolution, clear contrast, or excellent gradation reproducibility. Various development methods have been used, including not only normal development and analog development, but also reversal development, digital development, and low-potential development, and it is required to provide toner that provides high image quality for any development method. ing.

With miniaturization and personalization, products have been used in harsh environments such as high temperature and high humidity in tropical regions, low temperature and low humidity in inland regions, and in places without air conditioning, making them stable under any environment. must be provided with high-quality images. As speed increases, it is necessary to be able to use a large amount at a time or to use it continuously over a long period of time, and to stably provide high-quality images.

On the other hand, the performance required of toner is not limited to developability.
Various raw materials have been used to improve fixing properties, anti-offset properties, cleaning properties, and anti-blocking properties. As a result, the amount of triboelectric charge of other materials changes significantly, and the ability of charge control agents to simply "impart" or increase the charge is insufficient, and it is not possible to "control" the amount of charge on the toner at a constant level. It should not interfere with the other performance requirements and listed above, but rather should support it.

Toner is required to be controlled so that it is triboelectrically charged to a constant amount even during long-term use under any environment, and as a result, to provide stable high image quality. Therefore, conventional toners are no longer able to satisfy the various requirements mentioned above, and there is a need for improvement in charge control agents.

An object of the present invention is to provide a toner that provides a stable image without being affected by the environment such as temperature and humidity.

Another object of the present invention is to provide a toner that is highly durable and always provides stable images even when used continuously for a long period of time.

Still another object is to provide a toner that provides images with high resolution and fine line reproducibility.

Yet another object is to provide a toner that consistently provides high density, fog-free images.

Still another object is to provide an image that accurately represents delicate images and clearly represents images such as graphics.

Still another object is to provide a toner that can be used in both low-speed and high-speed machines.

Still another object is to provide a toner that does not deteriorate in performance even when left for a long period of time.

[Means and effects for solving the problems] The present invention has the following features:
The toner for developing electrostatic images is characterized in that it contains 0.01 to 10 parts by weight of a compound represented by the following general formula (I) based on 100 parts by weight of the resin component.

(Left below)
72.1173 is hydrogen, halogen, nitro, carbon number 1-
Represents 18 alkyl, alkenyl, aralkyl, aryl, or alkoxy, and X and Y are -o-,-
coo-, -s- or -NR5- (R5 is hydrogen or alkyl having 1 to 4 carbon atoms), N represents chromium, cobalt or iron, and A represents hydrogen, sodium, potassium, ammonium or organic ammonium. Representation,
II, ta, n represent 1 or 2. In addition, when it has multiple substituents, each of them may be the same or different. As a result of intensive research into toners that give images with high contrast, the general formula (I
) was found to be particularly excellent. That is, the compound represented by the general formula (I) used in the present invention is thermally and temporally stable,
The present invention was achieved by discovering that it is a high-quality charge control agent that has low hygroscopicity and, when included in a toner, provides a toner with excellent electrophotographic properties even under low humidity conditions.

In addition, the compound represented by the general formula (I) has the property of having a certain amount of charge due to triboelectrification and stably maintaining a certain amount of charge under any environment. . Further, the compound of general formula (I) has a deep color and is excellent in coloring agents.

Further, the toner containing the compound represented by the general formula (I) used in the present invention has good dispersion in the resin, and can be used between toner particles or between the toner and the carrier, and between the toner and the sleeve in the case of -component development. It has been found that the amount of triboelectric charge between the toner and the toner carrier is stable, the distribution of the amount of triboelectricity is sharp and uniform, and the toner can be controlled to the amount of charge suitable for the developing system used.

In particular, it was found that the reduction in image density and fog caused by the charge-up phenomenon in a low-humidity environment were significantly improved. This is because, when toner particles tend to have an excessive charge, the compound of general formula (I) in the toner particles skillfully adjusts the charge of the entire toner particle and maintains the amount of charge at an appropriate constant value. I'm thinking of becoming deaf.

Methods for incorporating the compound represented by general formula (I) used in the present invention into the toner include a method of adding it inside the toner and a method of adding it externally. The amount of these compounds used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner manufacturing method, including the dispersion method, and is not uniquely limited. However, it is preferably used in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the binder resin. In addition, when externally added, 0.
01 to 10 parts by weight is preferred.

The compound represented by general formula (I) used in the present invention is
It is obtained by treating a metallizable azo compound with a metallizing agent by a known method, and the counter ion can be changed depending on the subsequent treatment conditions.

For example, 4-acetyl-2-7 minophenol is diazotized, β-naphthol is coupled, treated with an inorganic chromium salt, filtered at pH 3 or lower, and the precipitate is collected at pH 6 to 7.
Compound (1) can be obtained by washing until .

Compound (1) Other specific examples of the compound represented by the general formula (I) used in the present invention include the following:
Synthesized in a similar manner.

(Hereinafter in the margin) Compound (2) (Hereinafter in the margin) Compound (3) (Hereinafter in the margin) Compound (4) The compound used in the present invention can also be used in combination with a conventionally known charge control agent.

Any suitable pigment or dye can be used as the colorant used in the present invention, and for example, known dyes and pigments such as carbon black, iron black, phthalocyanine blue, ultramarine blue, quinacridone, and benzidine yellow are used.

The binder resin used in the present invention includes styrene, 0-
Methylstyrene, l-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene,
p-Chlorstyrene, 3,4-dichlorostyrene, p-
Ethylstyrene, 2,4-dimethylstyrene, p-n
-butylstyrene, p-tert-butylstyrene,
Styrene and its derivatives such as p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene; ethylene, propylene, butylene, isobutylene, etc. Ethylenically unsaturated monoolefins; unsaturated polyolefins such as butadiene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, etc. Class: Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate , dimethylaminoethyl methacrylate, α-methylene aliphatic monocarboxylic acid esters such as diethylaminoethyl methacrylate, methyl diacrylate, ethyl acrylate, acrylic (7g-n-butyl,
Isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, acrylic acid
Acrylic acid esters such as 2-ethylhexyl, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; Vinyl methyl ketone, vinyl hexyl ketone, and methyl Vinyl ketones such as isopropenyl ketone;
N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and tovinylpyrrolidone; vinylnaphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, niacryl acid, methacrylic acid , vinyl compound derivatives having a carboxyl group such as maleic acid and fumaric acid; Hafester such as maleic acid Hafester and fumaric acid Hafester; maleic anhydride, maleic ester, fumaric ester derivative; Polymers, copolymers, polyesters, polyurethanes, epoxy resins, polyvinyl butyral, rosins, modified rosins, terpene resins, phenolic resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, haloparaffins, paraffin waxes, etc. Can be used alone or in combination.

In particular, binder resins for toners used in pressure fixing systems include low molecular weight polyethylene, low molecular weight polypropylene, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, higher fatty acids, polyamide resins, polyester resins, etc. can be used alone or in combination.

Furthermore, when the toner of the present invention is used as a two-component developer, it is mixed with carrier powder.

All known carriers can be used in the present invention, such as magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, etc., and carriers whose surfaces have been treated with resin, etc. Things can be given.

Furthermore, the toner of the present invention is capable of developing while applying an alternating electric field between the developer carrier and the latent image carrier in the development area of the developer carrier that faces the latent image carrier for holding the latent image. In an image forming method in which an image is developed with a non-magnetic toner, magnetic particles having a true specific gravity of 6 or less and coated with an electrically insulating resin increase the amount of magnetic particles present in the development area of a developer carrier. A magnetic brush is formed so that the concentration of the magnetic brush is 5 to 100 mg/c2, and there is a gap between the latent image carrier and the surface of the developer carrier and the surface of the magnetic brush formed on the surface of the developer carrier in the development area. It is also used in an image forming method characterized by developing a latent image while reciprocating magnetic toner.

The toner of the present invention may further contain a magnetic material and be used as a magnetic toner. The magnetic material contained in the magnetic toner of the present invention includes iron oxides such as magnetite, magnetite, ferrite, and other metal oxides. containing iron oxide,
Metals such as Fe, Co, old or these metals and Aj), Go, Cu.

Pb, Mg, old, Sn, Zn, Sb, Be,
Bi, Cd, Ca, Mn.

Examples include alloys with metals such as Se, Ti, W, and V, and mixtures thereof. These ferromagnetic materials have an average particle size of about 0.1 to 2 mm, and have magnetic properties such as coercive force of 20 to 1500 e and saturation magnetization of 50 to 200 e when IOK 6 e is applied.
mu/g (preferably 50-100e+wu/g)
, residual magnetization of 2 to 20 emu/H is desirable, and the amount contained in the toner is 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight, per 100 parts by weight of the resin component.

The toner of the present invention may be mixed with additives as necessary. Examples of the additives include lubricants such as Teflon, polyvinylidene fluoride, and fatty acid metal salts; or cerium oxide,
Abrasives such as strontium titanate and silicon carbide; or flowability agents and anti-caking agents such as colloidal silica and alumina; or conductivity agents such as carbon black and tin oxide; or fixing aids such as low molecular weight polyethylene, etc. 0.5 to 5v of waxy substances such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, and Sasol wax are used to improve mold release properties during hot roll fixing.
It is also possible to add about t%.

In manufacturing the toner according to the present invention, the constituent materials are sufficiently mixed using a ball mill or other mixer, and then
A method of obtaining by thoroughly kneading using a heat kneader such as a hot roll, niegu, extruder, etc., cooling and solidifying, and then mechanically crushing and classifying, or dispersing the constituent materials in a binder resin solution and then spray drying. A polymerization toner production method in which the monomers to constitute the binder resin are mixed with predetermined materials to form an emulsified suspension and then polymerized; In the microcapsule toner, a method of containing a predetermined material in the core material, the shell material, or both can be applied.

In the toner of the present invention, the acid value of the soluble component of the toner is preferably 50 or less, more preferably 25 or less, and when the acid value of the soluble component of the toner is below the above range, The charge control action of the compound of general formula (I) used in the present invention works most effectively, exhibits superior developability, and can provide high-quality images. Acid value is 50
If it exceeds 100%, the amount of charge becomes excessive under low humidity, resulting in a decrease in developability.

In the present invention, the acid value is a numerical value expressed in mg of potassium hydroxide required to neutralize 1 g of a sample, and is measured as follows.

2 g of the soluble component was dissolved in 200 g of a mixed solvent of toluene/ethanol = 271, and phenolphthalein was used as an indicator. Titrate with IN potassium hydroxide solution.

Further, in the heat fixing toner of the present invention, the molecular weight of the tetrahydrofuran soluble component of the toner is Mn 2,000.
~20,000, Mw is ~50,000s, ooo, o
oo, preferably 50,000 to 3,000,000
It is good that

In the present invention, the values of Mw and Mn are calculated from the values measured by gel permeation chromatography, and the measurement conditions are as follows: Tetrahydrofuran is flowed as a solvent at a flow rate of Lrall per minute at a temperature of 25°C, and the sample concentration is 8.
I1g/II! ! A sample solution of tetrahydrofuran of
．． 5mj) Inject and measure. In addition, as a column,
In order to accurately measure the molecular weight range of 103 to 2 x 106, it is recommended to combine multiple commercially available polystyrene gel columns, such as G-ST7R manufactured by Waters.
ageI! 500.103.10', 105c7) combination and 5hodex A-802,80 manufactured by Showa Denko
The combination of 3,804,805 is good.When measuring the molecular weight of a sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithm value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. . As a standard polystyrene sample for creating a calibration curve, for example, Pressu
re Chemicaj) Co. or Toyo Tsudani Gyo Co., Ltd. with a molecular weight of 6 x 102.2. IX 103
,4 X 103°1.75X 104.5. IX 1
04.1. IX 105.3.9X 105°8, G
It is appropriate to use a standard polystyrene sample of at least about 1O point, with a polystyrene of X 105,2 X 106.4.48 X 106. In addition, the detector has RI (
refractive index) detector.

In a heat fixing toner that has been roughly kneaded and pulverized, the tetrahydrofuran insoluble portion of the resin component in the toner is 70vt.
% or less, preferably 10 to 60 wt%, more preferably 10 to 50 wt%, the compound of general formula (I) used in the present invention is well dispersed in the toner and the charge control effect is effectively exhibited. be done. When the amount of tetrahydrofuran is less than 10 wt %, the compound used in the present invention is poorly dispersed, resulting in variations in toner particles, poor durability, and problems such as a decrease in density and fogging during use may occur. Moreover, when it exceeds 70 wt%, there are disadvantages such as problems in manufacturing such as poor fixing and insufficient kneading when using a kneading method.

In the present invention, the tetrahydrofuran insoluble content is the proportion of a portion of the polymer that has become insoluble in a solvent. The tetrahydrofuran-insoluble content is defined by the value measured as follows. In other words, the toner is kept at a certain weight (Wag).
) Weigh the polymer, extract it with a Soxhlet extractor using a thimble filter paper (Toyo Roshi No. 86R), remove the soluble components in the polymer with a solvent, and dry the sample that remained unextracted. Weigh (12g).

If w3 is the weight of solid components such as magnetic material and silica contained in the toner, the solvent-insoluble content is calculated as 2-W3 [T x 100 (X)]. For example, tetrahydrone is suitable as such a solvent, and extraction was carried out for about 6 hours here.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. All parts in the following formulations are parts by weight.

Example 1 After premixing the above materials, they were kneaded with two rolls heated to 150°C, cooled, coarsely pulverized with a cutter mill, pulverized with a pulverizer using a jet stream, and further pulverized with a wind classifier. A fine powder with a volume average particle diameter of 11.5 grs was obtained. This was thoroughly mixed with 0.4 part of hydrophobic colloidal silica to obtain toner N011. Table 1 shows the physical properties of this toner N001.

This toner is applied to a commercially available electronic copying machine (product name NP-8570).
．． When we conducted a continuous copying test of 30,000 sheets under normal conditions using a Canon product, clear images with high image density (1.3 to 1.4) and no fog were obtained throughout the test. It was done. A similar test was also carried out at 15°C and 10% R.
When it was carried out under the low temperature and low humidity conditions of
), good images were obtained. In addition, the amount of electricity disseminated is 1g of toner and iron powder carrier (200/300meSh) 9
After weighing and mixing thoroughly, measurement was performed using a blow-off (TB-200 manufactured by Toshiba Chemical Corporation).

Example 2 A toner N002 having a volume average particle size of 12 mm was obtained in the same manner as in Example 1 except for using the above materials, using an extruder as the kneading device. Table 1 shows the physical properties of toner No. 2.

Commercially available laser beam printer (product name LBP-CX)
When a printout test was conducted using a Canon product, an image with high resolution and high image density (1.35 to 1.4) was obtained. Further, at 15°C, 10% RH, 35°C, 80
A similar test under %RH yielded similar results.

Example 3 Toner No. 3 having a volume average particle diameter of 12#Ll+ was obtained in the same manner as in Example 1 except that the above materials were used. Toner No.
, 3 are shown in Table 1.

Toner No. 3 was added to a commercially available copier (product name NP-250R).
As a result of a continuous copying test of 30,000 sheets under normal environment with E, cannon acid), the image density was stable (1.
1.35) and a fog-free image was obtained. Furthermore, even in the same test under each environment (15° C., 10% RH, 135° C., 80% RH), excellent images similar to those under normal environment 1 were obtained.

Example 4 Toner No. 4 was obtained in the same manner as in Example 1 except for using the above materials. Table 1 shows the physical properties of toner N004.

The toner was mixed at a ratio of 5 parts to 100 parts of ferrite carrier having an average particle size of 50 to 80 l to prepare a developer. This is commercially available electronic copy a (product name MP-5000)
When we conducted a continuous copying test of 30,000 sheets with Canon), the image density was high (1.35 to 1.4).
Clear, fog-free images were stably obtained. 1 more
When similar tests were conducted under the following environments: 5° C., 10% R) f and 30° C., 90% R) l, good images were obtained as in the normal environment.

Comparative Example 1 Toner No. 5 having a volume average particle size of 11.5 gm was obtained in the same manner as in Example 1, except that two parts of the following monoazo compound chromium complex were used instead of compound (1). Toner N06
The physical properties of No. 5 are shown in Table 1.

As a result of carrying out the same copying test as in Example 1, good images were obtained under normal conditions, but at 15°C and 10% R.
Under the low temperature and low humidity environment of H, a charge-up phenomenon occurred, the image density was low ((1.0 to 1.1)), and fogging also occurred.

Comparative Example 2 Toner No. 6 having a volume average particle size of 1.5 μm was obtained in the same manner as in Example 2, except that 0.5 part of the following monoazo compound chromium complex was used instead of compound (2). Toner N
The physical properties of o and 6 are shown in Table 1.

As a result of carrying out the same copying test as in Example 2, almost good images were obtained under normal conditions, but at 35°C and 80°C.
% RH, the image density decreased to a certain extent (1.0 to 1.05) that was problematic in practice.

[Effects of the Invention] The toner of the present invention can be used for developing electrostatic charge images in electrophotography, electrostatic recording, electrostatic printing, etc. by any conventionally known means. It produces such excellent effects.

■ Decrease in image density, which becomes a problem in low humidity environments, etc.
A charge-up phenomenon accompanied by fog etc. does not occur, and good images can be stably obtained.

■ Good images with high image density can be obtained even under high humidity conditions.

- Good images with high image density and no fogging can be obtained regardless of whether it is used in low-speed or high-speed machines with different copying speeds.

■ It has excellent resolution and line reproducibility, and is advantageous for digital development, which requires high resolution.

Claims (1)

[Claims] (1) For 100 parts by weight of the resin component, apply the following general formula (
A toner for developing electrostatic images, characterized in that it contains 0.01 to 10 parts by weight of the compound represented by I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R_1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼(
R^4 represents alkyl or alkenyl having 1 to 18 carbon atoms, or aralkyl or aryl which may have a substituent on the aromatic ring, and R^2 and R^3 represent hydrogen, halogen, nitro, carbon Represents 1 to 18 alkyl, alkenyl, aralkyl, aryl, or alkoxy, and X and Y are -O-, -COO-, -S-, or -N
R^5- (R^5 is hydrogen or alkyl having 1 to 4 carbon atoms), M represents chromium, cobalt or iron, A represents hydrogen, sodium, potassium, ammonium or organic ammonium, l, m and n are 1 or 2
represents. In addition, when it has multiple substituents, each may be the same or different. ]