JPH0820771B2 - Toner for electrostatic image development - Google Patents

Description

The present invention relates to a toner for developing an electrostatic latent image such as electrophotography and electrostatic recording.

[Prior Art] In a toner for developing an electrostatic charge image, a constant chargeability cannot be obtained by the binder resin used alone,
In order to control the toner to a desired triboelectric chargeability, charge control substances such as dyes and pigments are added.

Today, as a practical application in the technical field, a nigrosine dye is used to apply or control a positive charge to a toner, and a negative charge is applied or controlled to a toner, Japanese Patent Publication No. 45-26478. And metal-containing compounds disclosed in JP-B-55-42752 and the like. These compounds, in terms of the ability to impart a charge to the toner particles,
It has been possible to provide a toner which has particularly excellent properties among the charge control substances proposed hitherto, and which gives a practically sufficient image even in a conventional copying machine or the like.

[Problems to be Solved by the Invention] However, as electrophotography and electrostatic recording media are becoming more personalized, faster, and multifunctional, they have better environmental stability and good durability stability. There is a demand for a toner having a higher density, no fog, a high resolution, a clear contrast, or an image excellent in gradation reproducibility. Various development methods such as reversal development, digital development, low potential development as well as positive development and analog development have been used, and it is required to provide a toner that gives high image quality to any development method. ing.

Due to miniaturization and personalization, it has been used severely under high temperature and high humidity in the tropics, under low temperature and low humidity in the inland regions, and in places without air conditioning, and is always stable in any environment. Must give high quality images to. Further, due to the high speed, it is necessary to endure a large amount of use at one time or a continuous use for a long time and stably provide a high quality image.

On the other hand, various raw materials have been used to improve not only the developability but also the fixability, anti-offset property, cleaning property, and anti-blocking property required for toner. Along with this, the triboelectric charge amount of other materials also changes significantly, and the charge control agent simply “gives” the charge, that is, the function of increasing the charge is not sufficient, and it is possible to “control” the charge amount of the toner to a constant level. Those that are sought and should not interfere with the other performances listed above, but rather assist, are preferred.

The toner is controlled so that it is always triboelectrically charged to a constant amount of charge during long-term use in any environment.
As a result, it is necessary to provide a stable image quality. Therefore, the conventional toner cannot satisfy the above-mentioned various requirements, and it is necessary to improve the charge control agent.

An object of the present invention is to provide a toner that gives a stable image regardless of the environment such as temperature and humidity.

Another object of the present invention is to provide a toner which is excellent in durability and always gives a stable image even when continuously used for a long period of time.

Still another object is to provide a toner which gives an image having excellent resolution and fine line reproducibility.

Still another object is to provide a toner that always has a high density and gives a fog-free image.

Still another object is to provide an image in which a delicate image is precisely expressed and a graphic image or the like is clearly expressed.

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

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

[Means and Actions for Solving Problems] The present invention relates to the following general formulas (I) and (II) based on 100 parts by weight of a resin component containing a resin containing a tetrahydrofuran insoluble component. (III) or (IV) General formula (I) General formula (II) General formula (III) General formula (IV) [In the formula, R ¹ is alkyl having 1 to 18 carbons, alkenyl,
Represents alkyl, aryl, R ² represents hydrogen, halogen, nitro, or alkoxy having 1 to 18 carbons, R ³ represents hydrogen, halogen, nitro, carboxyl, anilide, or alkyl having 1 to 18 carbons. , Alkenyl, aralkyl, aryl, alkoxy or carboxyester. X and Y are -O-, -COO-, -S
-, or -NR ⁴ - (R ⁴ is alkyl of 1 to 4 carbon atoms)
Represents, scandium, vanadium, manganese,
Represents nickel or zinc, A is hydrogen, sodium,
Represents potassium, ammonium or organic ammonium, 1 represents 1 or 2 and m, n represents 1, 2 or 3. When it has a plurality of substituents, they may be the same or different. ] The toner for developing an electrostatic charge image containing 0.01 to 10 parts by weight of the compound represented by the following, wherein the resin component in the toner comprises 70% by weight or less of tetrahydrofuran insoluble matter and 30% by weight or more of tetrahydrofuran soluble matter. The present invention relates to a toner for developing an electrostatic charge image, which contains the tetrahydrofuran-soluble component and has an acid value of 50 or less.

Furthermore, in the present invention, the resin component in the toner is 70% by weight.
~ 10 wt% tetrahydrofuran insolubles and 30 wt% ~
The toner for developing an electrostatic image as described above, which contains 90% by weight of a tetrahydrofuran-soluble component.

The present inventors have earnestly studied a toner that is stably charged negatively in any environment and gives a stable image for a long period of time, and as a result, the general formulas (I), (II), (II
It has been found that the toner containing the compound represented by I) or (IV) is particularly excellent. That is, when the compound represented by the general formula (I), (II), (III) or (IV) used in the present invention is thermally and temporally stable, has a low hygroscopic property, and is contained in the toner. The present invention has been accomplished by finding that it is a high-quality charge control agent that gives a toner having excellent electrophotographic characteristics even under low humidity.

Furthermore, the acid value of the tetrahydrofuran-soluble component of the toner is 50
It was also found that the excellent charge control action of the compound of the general formula (I), (II), (III), or (IV) effectively works when the following is true.

Further, some of the compounds represented by the general formula (I), (II), (III) or (IV) have a weak coloring power, so that they may be used in combination with other coloring materials for color toners. it can.

Further, the general formulas (I), (II) used in the present invention,
The toner containing the compound represented by (III) or (IV) is well dispersed in the resin, and the compound represented by formula (I), (II), (III) or (IV) is well dispersed in the resin. In particular, using a resin component containing a resin containing a tetrahydrofuran insoluble matter, the tetrahydrofuran insoluble matter of the toner is 70% by weight or less, more preferably 70% by weight.
When the content of the toner particles is from 10 to 10% by weight, the dispersibility of the compound represented by the general formula (I), (II), (III) or (IV) into the resin is good. , Or between the toner and the carrier, or between the toner and the toner carrier such as the sleeve in the case of one-component development, the triboelectric charge amount is stable, and the triboelectric charge amount distribution is sharp and uniform. It has been found that the toner can be controlled to a suitable charge amount.

General formulas (I), (II) and (III) used in the present invention
Alternatively, as a method of incorporating the compound represented by (IV) into the toner, there are a method of adding it inside the toner and a method of adding it externally. The amount of these compounds used depends on the type of binder resin,
The presence or absence of additives used as necessary, which is determined by the toner production method including the dispersion method, is not uniquely limited, but preferably 0.1 to 100 parts by weight of the binder resin. To 10 parts by weight, more preferably 0.1 to 5 parts by weight. When adding externally, resin 10
0.01 to 10 parts by weight is preferable to 0 parts by weight.

General formulas (I), (II) and (III) used in the present invention
Alternatively, the compound represented by (IV) can be obtained by treating a metallizable azo compound with a metal-providing agent by a known method, and the counter ion can be changed depending on the subsequent treatment conditions.

For example, 4-methyl-6-chloro-2-aminophenol is diazotized and β-naphthol is coupled,
The compound (1) is obtained by treating with an inorganic manganese salt and then filtering off at pH 3 or less, and washing the precipitate until pH 6 to 7.

Compound (1) General formulas (I), (II) and (III) used in the present invention
Alternatively, other specific examples of the compound represented by (IV) include the following, which are synthesized by the same method.

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

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

Examples of the binder resin used in the present invention include styrene, o
-Methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p
-Ethylstyrene, 2,4-dimethylstyrene, pn-
Butyl styrene, p-tert-butyl styrene, pn-
Hexyl styrene, pn-octyl styrene, pn
-Nonylstyrene, pn-decylstyrene, pn-
Styrene and its derivatives such as dodecyl styrene; Ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Unsaturated polyolefins such as butadiene; Halogen such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride Vinyl esters; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, -n-octyl methacrylate, Α-Methylene aliphatic monocarboxylic acid ethers such as dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate. Teres; Methyl acrylate, Ethyl acrylate, N-butyl acrylate, Isobutyl acrylate, Propyl acrylate, N-octyl acrylate, Dodecyl acrylate, 2-Ethylhexyl acrylate, Stearyl acrylate, Acrylic acid 2-Acrylic esters such as chloroethyl and phenyl acrylate; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N- Vinylpyrrole, N-vinylcarbazole, N-vinylindole,
N-vinyl compounds such as N-vinylpyrrolidone; vinylnaphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide; acrylic acid, methacrylic acid, maleic acid,
A vinyl compound derivative having a carboxyl group such as fumaric acid; a half ester such as a maleic acid half ester and a fumaric acid half ester; a maleic anhydride, a maleic acid ester, a fumaric acid ester derivative; , Copolymer, polyester, polyurethane, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, haloparaffin, paraffin wax, etc. Alternatively, they can be mixed and used.

In particular, as a binder resin for the toner to be used in the pressure fixing method, low molecular weight polyethylene, low molecular weight polypropylene,
An ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, a higher fatty acid, a polyamide resin, a polyester resin or the like can be used alone or in combination.

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

As the carrier that can be used in the present invention, all known carriers can be used, for example, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads and the like and their surfaces treated with a resin or the like. Something is included.

Further, the toner of the present invention is a developing area of a developer carrying member facing a latent image holding member for holding a latent image, while applying an alternating electric field between the developer carrying member and the latent image holding member. In an image forming method of developing an image with a non-magnetic toner, the magnetic particles having a true specific gravity of 6 or less and covered with an electrically insulating resin prevent the presence of the magnetic particles in the developing area of the developer carrier. A magnetic brush is formed so as to have a concentration of 5 to 100 mg / cm ^2, and nonmagnetic 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 developing region. It is also used in an image forming method characterized by developing a latent image while reciprocating toner.

Further, the toner of the present invention can be used as a magnetic toner by further containing a magnetic material. The magnetic material contained in the magnetic toner of the present invention includes magnetite, maghemite, iron oxide such as ferrite, and iron oxide containing other metal oxides, metals such as Fe, Co, Ni, or these metals and A.
l, Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, V
Alloys with metals such as and mixtures thereof. These ferromagnetic materials have an average particle size of 0.1 to 2 μm
It is desirable that the magnetic properties under application of 0 Ke are coercive force of 20 to 150e, saturation magnetization of 50 to 200emu / g (preferably 50 to 100emu / g), and residual magnetization of 2 to 20emu / g, and the amount contained in the toner. As, 20 to 200 parts by weight with respect to 100 parts by weight of the resin component,
It is particularly preferably 40 to 150 parts by weight.

The toner of the present invention may be mixed with an additive as required. Examples of additives include lubricants such as Teflon, polyvinylidene fluoride, and fatty acid metal salts; or abrasives such as cerium oxide, strontium titanate, and silicon carbide;
Alternatively, there are fluidity-imparting agents such as colloidal silica and alumina, anti-caking agents; or conductivity-imparting agents such as carbon black and tin oxide; or fixing aids such as low molecular weight polyethylene. For the purpose of improving the quality, wax-like substances such as low-molecular weight polyethylene, low-molecular weight polypropylene, microcrystalline wax, carnauba wax and Sazol wax are added in an amount of 0.5-5.
You can also add about wt%.

In producing the toner according to the present invention, the constituent materials are thoroughly mixed by a ball mill or other mixing machine, and then thoroughly kneaded by using a heat kneader such as a heat roll, a kneader or an extruder, and after cooling and solidification, a machine is used. Pulverizing, classifying, classifying the binder resin solution and then spray-drying the constituent materials, mixing the binder resin with the desired material and emulsifying A polymerization method of producing a suspension and then polymerizing it, or a so-called microcapsule toner comprising a core material and a shell material, a method of containing a predetermined material in the core material or the shell material, or both can be applied. .

The toner of the present invention preferably has an acid value of the soluble component of the toner of 50 or less, more preferably 25 or less. When the acid value of the soluble component of the toner is less than the above, the general formulas (I), (II) used in the present invention,
The charge control action of the compound of (III) or (IV) works most effectively, shows better developability, and can give a high quality image. When the acid value exceeds 50, the charge amount becomes excessive under low humidity and the developability deteriorates.

In the present invention, the value of the acid value is a 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 is dissolved in 200 g of a mixed solvent of toluene / ethanol = 2/1, and titrated with a 0.1 N potassium hydroxide solution using phenolphthalein as an indicator.

Further, in the heat fixing toner of the present invention, the tetrahydrofuran-soluble component of the toner has a molecular weight Mn of 2,000 to 20,
000, Mw 50,000-5,000,000, preferably 50,000-3,00
What is 0,000 is good.

In the present invention, the values of Mw and Mn were calculated from the values measured by gel permeation chromatography. The measurement conditions are as follows: Tetrahydrofuran is used as a solvent at a flow rate of 1 ml per minute at a temperature of 25 ° C., and 0.5 ml of a tetrahydrofuran sample solution having a sample concentration of 8 mg / ml is injected. As a column, a plurality of commercially available polystyrene gel columns may be combined in order to accurately measure the molecular weight region of 10 ³ to 2 × 10 ⁶ , for example, μ-styr manufactured by waters.
agel 500,10 ^3, 10 ^4, made of 10 ⁵ of combinations and Showa Denko KK shodex
A combination of A-802,803,804,805 is good. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Che
mical Co. or Toyo Soda Kogyo Co., Ltd. has a molecular weight of 6 × 1
0 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9
It is suitable to use those of × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ and at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

Furthermore, in the heat fixing toner that has been kneaded and pulverized, the tetrahydrofuran component in the resin component of the toner is 70 wt%
The following, preferably 10 to 60 wt%, more preferably 10 to 50
When it is wt%, the general formula (I) used in the present invention,
The compound (II), (III) or (IV) is well dispersed in the toner, and the charge control action is effectively exhibited. When the tetrahydrofuran insoluble content is less than 10 wt%, the dispersion of the compound used in the present invention is poor, toner particles may be dispersed, durability may be poor, and problems such as concentration decrease and fogging during use may occur. . On the other hand, when it exceeds 70 wt%, there are drawbacks such as a problem in production such as poor fixing and insufficient kneading when a kneading method is used.

The tetrahydrofuran-insoluble matter in the present invention is a ratio of a polymer portion which becomes insoluble in a solvent. Tetrahydrofuran insoluble matter is defined by the value measured as follows. That is, a certain weight of toner (W
₁ g) Weigh out and extract with a Soxhlet extractor using a cylindrical filter paper (Toyo Roshi Kaisha No.86R), remove the soluble components in the polymer with a solvent, and extract the remaining sample without extraction. After drying, weigh (W ₂ g).

Let W ₃ be the weight of the magnetic substance and solid components such as silica contained in the toner. Calculated as Tetrahydrofuran is suitable as such a solvent, and it is extracted here for about 6 hours.

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

Example 1 After premixing the above materials, kneading with two rolls heated to 150 ° C, cooling, coarse crushing with a cutter mill, crushing with a fine crusher using a jet stream, and further classification with an air classifier As a result, a fine powder having a volume average particle diameter of 11 μm was obtained. This was mixed well with 0.4 parts of hydrophobic colloidal silica and toner N
I got o.1. The physical properties of Toner No. 1 are shown in Table 1.

When this toner was subjected to a copying test under a normal environment with a commercially available copying machine (trade name: NP-7550, Canon product), a high quality image faithful to the original was obtained. As a result of further repeated copying test of 50,000 sheets, a stable and good image was obtained during the test, the density was maintained at 1.3 to 1.4, no fog was observed at all, and the reproduction of thin letters was excellent. I didn't see any thinning. Furthermore, under low temperature and low humidity of 15 ℃, 10% RH, 30 ℃, 85
Similar results were obtained under high temperature and high humidity of% RH.

The charge amount is 1g of toner and iron powder carrier (200 / 300m
esh) 9 g was precisely weighed and thoroughly mixed, and then measured by blow-off (TB-200 manufactured by Toshiba Chemical Co.).

Example 2 Toner No. 2 having a volume average particle diameter of 12 μm was obtained in the same manner as in Example 1 except that the above materials were used. Table 1 shows the physical properties of Toner No. 2.

A developer was prepared by mixing 5 parts of the toner with 100 parts of an iron powder carrier having an average particle size of 50 to 80 μm. 10,000 using a commercially available electronic copier (product name: NP-5000, Canon product)
When a durable copy test was performed on a sheet, a stable blue high-resolution image was obtained and no fog was observed. Further similar tests were carried out at 15 ° C, 10% RH, 35 ° C, 80% RH, and similar results were obtained.

Example 3 A toner No. 3 having a volume average particle diameter of 12 μm was obtained in the same manner as in Example 1 except that the above materials were used and an extruder was used as a kneading device. Table 1 shows the physical properties of Toner No. 3.

When I performed a printout test with a commercially available laser beam printer (trade name LBP-CX, Canon product),
A high resolution image was obtained. As a result of repeatedly printing 3,000 sheets, the density remained at 1.30 to 1.40 and no fog was observed. Further, similar tests under the environments of 15 ° C, 10% RH, 35 ° C, 80% RH also obtained the same excellent images as in the normal environment.

Comparative Example 1 The following monoazo compound chromium complex was used instead of the compound (1). Toner No. 4 having a volume average particle size of 11.5 μm was obtained in the same manner as in Example 1 except that 2 parts of was used. Table 1 shows the physical properties of Toner No. 4.

As a result of the same copying test as in Example 1, a good image was obtained up to 50,000 sheets, but the density was lower than that in Example and was 1.1 to 1.2. Further, under the environment of low temperature and low humidity of 15 ° C. and 10% RH, the density gradually decreased and became 1.0 to 1.1 in 20,000 copies.

Comparative Example 2 The following monoazo compound chromium complex was used instead of the compound (3). Toner No. 5 having a volume average particle size of 11.5 μm was obtained in the same manner as in Example 3 except that 0.5 part of was used. Table 1 shows the physical properties of Toner No. 5.

As a result of the same copying test as in Example 3, good images were obtained up to 3,000 sheets, but the density was 1.2, which is lower than that in Example 3. Furthermore, the density was unstable under the conditions of 15 ° C and 10% RH and varied from 1.1 to 1.3, and the image had some fog.

[Effects of the Invention] The toner of the present invention is a conventionally known means and can be used for development for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, etc., and is described below. It produces such an excellent effect.

The triboelectric charge amount between the toner particles is uniform, and the control of the electric charge amount is easy. Further, the toner is stable during long-term continuous use or does not vary or decrease in triboelectric charge amount depending on the environment.

It is a toner which is not affected by humidity and gives a stable image under high humidity and low humidity.

It is a toner that gives stable images without being affected by temperature.

It is a toner that has excellent durability and always gives a stable image even when it is continuously used for a long period of time.

It is a toner that is excellent in resolving power and always gives a high-quality image with high density and no fog.

Since it has a low tinting strength, it can also be used for color toners.

It is a toner that gives an excellent image when developing a low-potential latent image.

Claims (2)

[Claims] 1. A compound represented by the following general formula (I), (II), (III) or (IV) with respect to 100 parts by weight of a resin component containing a resin containing a tetrahydrofuran insoluble component. ) General formula (II) General formula (III) General formula (IV) [In the formula, R ¹ is alkyl having 1 to 18 carbons, alkenyl,
Represents alkyl, aryl, R ² represents hydrogen, halogen, nitro, or alkoxy having 1 to 18 carbons, R ³ represents hydrogen, halogen, nitro, carboxyl, anilide, or alkyl having 1 to 18 carbons. , Alkenyl, aralkyl, aryl, alkoxy or carboxyester. X and Y are -O-, -COO-, -S
-, or -NR ⁴ - (R ⁴ is alkyl of 1 to 4 carbon atoms)
Represents, scandium, vanadium, manganese,
Represents nickel or zinc, A is hydrogen, sodium,
Represents potassium, ammonium or organic ammonium, 1 represents 1 or 2 and m, n represents 1, 2 or 3. When it has a plurality of substituents, they may be the same or different. ] A toner for developing an electrostatic charge image containing 0.01 to 10 parts by weight of the compound represented by the formula (1), wherein the resin component in the toner comprises 70% by weight or less of tetrahydrofuran insoluble matter and 30% by weight or more of tetrahydrofuran soluble matter. An electrostatic charge image developing toner containing the tetrahydrofuran-soluble component having an acid value of 50 or less. 2. The toner according to claim 1, wherein the resin component in the toner contains 70% by weight to 10% by weight of tetrahydrofuran insoluble matter and 30% by weight to 90% by weight of tetrahydrofuran soluble matter. The toner for developing an electrostatic charge image according to claim 1.