JPH05297638A - Negatively charging electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain a negatively charging toner having good stability, good dispersibility and good tridoelectrification property by using a specified compd. as a charge controlling agent. CONSTITUTION:The compd. expressed by formula I is incorporated into the toner. In the formula I, X and Y are independently hydrogen atom, and compd. expressed by formula II, etc., but both of X and Y are not simultaneously hydrogen atoms and Z is hydrogen atom, alkyl group, or aryl group. In the formula II, D is an electron donative group, R1 and R2 are hydrogen atoms, halogen atoms, alkyl groups, cycloalkyl groups, aralkyl groups, aryl groups, acyl groups, cyano groups, or nitro groups. Namely, the toner consists essentially of a binder resin, coloring agent and the compd. expressed by the formula I. This toner is obtd. by kneading the mixture in a heater mixer while the binder resin is molten, and then cooling, pulverizing and classifying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negatively chargeable electrophotographic toner containing a specific compound.

[0002]

2. Description of the Related Art In an electrophotographic image forming process, an electrostatic latent image is formed on an inorganic photoreceptor such as selenium, selenium alloy, cadmium sulfide, or amorphous silicon, or an organic photoreceptor using a charge generating agent and a charge transporting agent. After being formed, this is developed with toner, transferred onto paper or a plastic film, and fixed to obtain a visible image.

The photosensitive member has a positive charging property and a negative charging property depending on its configuration. When the printed portion is left as an electrostatic latent image by exposure, it is developed with a toner of opposite sign charging, while the printed portion is discharged. When reversal development is carried out, the development is carried out with a toner having the same sign. A toner is composed of a binder resin, a colorant and other additives, but is generally a charge control agent in order to impart desirable triboelectrification characteristics (charging speed, charging level, charging stability, etc.), temporal stability and environmental stability Is used. The characteristics of the toner are greatly affected by this charge control agent.

Negative charging toner is used in the case of developing with the opposite sign charging toner using the positive charging photoreceptor and in the case of reversal development using the negative charging photoreceptor, in which case negative charging is used. A sex charge control agent is used.

Further, in the case of a color toner, a light color, preferably colorless charge control agent which does not affect the hue is required. Examples of these light-colored or colorless charge control agents include, for example, JP-B-55-42752 and JP-A-61-61.
-69073, a metal complex salt compound of a hydroxybenzoic acid derivative described in JP-A-61-221756, etc.,
Aromatic dicarboxylic acid metal salt compounds described in JP-A-57-111441, JP-A-61-114545
3, metal complex salt compounds of anthranilic acid derivatives described in JP-A-62-94856, USP-4767.
688, organic boron compounds described in JP-A-1-306861 and the like, and biphenol compounds described in JP-A-61-3149.

However, these charge control agents are chromium compounds which may cause environmental problems, may not be completely colorless, or may have a low charge imparting effect or may have a large amount of reversely charged toner. There are drawbacks such as poor dispersibility and poor compound stability, and none of them have satisfactory performance as a charge control agent.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the stability of the compound is good, the dispersibility in the binder resin is good, there is no deterioration at the time of toner production, and the charging property due to friction is maintained even under various environmental conditions. The present invention provides a toner that always gives a good and high-quality image in a stable manner.

[0008]

The present inventors have found a colorless stable compound which has good dispersibility with a binder resin and can impart good charging characteristics to a toner. The present invention has led to the invention of excellent toners.

That is, the present invention is represented by the following general formula (1)

[0010]

[Chemical 5]

[Wherein X and Y are each independently a hydrogen atom,

[Chemical 6] (Wherein D represents an electron-donating group, R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an acyl group, a cyano group, or a nitro group. ,),

[Chemical 7] (In the formula, D and R ₁ and R ₂ have the same meanings as described above.)
Or

[Chemical 8] (In the formula, D and R ₁ and R ₂ have the same meanings as described above.)
However, X and Y are not hydrogen at the same time, and Z is a hydrogen atom, an alkyl group or an aryl group. ] A negatively chargeable electrophotographic toner containing a compound represented by the following.

The present invention basically comprises a binder resin, a colorant and a compound represented by the general formula (1) according to the present invention. As a method for producing the toner of the present invention, a mixture of these is used. Method of obtaining by kneading, cooling, coarsely pulverizing, finely pulverizing, and classifying after melting the binder resin by a heating and mixing device, dissolving these mixtures in a solvent, atomizing by spraying, drying, and classifying And a method in which the colorant or the compound represented by the general formula (1) is dispersed in the suspended monomer particles to obtain it by a polymerization method.

As the binder resin, polystyrene,
Styrene-methacrylic acid ester copolymer, styrene-
Propylene copolymer, styrene-butadiene copolymer,
Acrylic resins, styrene-maleic acid copolymers, olefin resins, polyesters, epoxy resins, polyurethane resins, polyvinyl butyral, etc. can be used alone or in combination.

As a colorant, carbon black is generally used for black toners, and the following colorants can be used for color toners. Examples of yellow colorants include azo organic pigments such as CI Pigment Yellow 1, CI Pigment Yellow 5, CI Pigment Yellow 12, and CI Pigment Yellow 17, and inorganic pigments such as ocher or CI Solvent Yellow 2, CI Solvent Yellow 6, CI. Magenta colorants such as oil-soluble dyes such as Solvent Yellow 14 and CI Solvent Yellow 19 are azo pigments such as CI Pigment Red 57 and CI Pigment Red 57: 1, and xanthene pigments such as CI Pigment Violet 1 and CI Pigment Red 81. , CI Pigment Red 87, CI Butt Red 1,
Examples of cyan colorants such as thioindigo pigments such as CI Pigment Violet 38 or oil-soluble dyes such as CI Solvent Red 19, CI Solvent Red 49 and CI Solvent Red 52 include triphenylmethane pigments such as CI Pigment Blue 1 and CI Pigment Blue 15 Phthalocyanine pigments such as CI Pigment Blue 17 or CI Solvent Blue 25, CI Solvent Blue 40, CI
Known colorants such as oil-soluble dyes such as Solvent Blue 70 can be used.

The electron-donating group of the compound according to the present invention which can be used as a charge control agent is an alkyl group, a cycloalkyl group, an aralkyl group, a hydroxyl group, an alkoxy group, an amino group, a dialkylamino group, a diaralkylamino group, And a diallylamino group.

Specific examples of the compound according to the present invention that can be used as the charge control agent include the following.

Compound No. (1)

[Chemical 9]

Compound No. (2)

[Chemical 10]

Compound No (3)

[Chemical 11]

Compound No (4)

[Chemical 12]

Compound No. (5)

[Chemical 13]

Compound No. (6)

[Chemical 14]

Compound No. (7)

[Chemical 15]

Compound No. (8)

[Chemical 16]

Compound No. (9)

[Chemical 17]

Compound No. (10)

[Chemical 18]

Compound No. (11)

[Chemical 19]

Compound No. (12)

[Chemical 20]

Compound No (13)

[Chemical 21]

Compound No (14)

[Chemical formula 22]

Compound No. (15)

[Chemical formula 23]

Compound No. (16)

[Chemical formula 24]

Compound No. (17)

[Chemical 25]

The toner may be used as an additive in the toner.
For the purpose of carrier protection, toner fluidity improvement, thermal / electrical / physical property adjustment, resistance adjustment, softening point adjustment, and fixability improvement, hydrophobic silica, metal soap, fluorine-based surfactant, Dioctyl phthalate, wax, tin oxide, conductive zinc oxide and the like are used as necessary.

When the toner of the present invention is used as a two-component developer, as a carrier, fine glass beads, iron powder, ferrite powder, a binder type carrier of resin particles in which magnetic particles are dispersed or a polyester resin on the surface, Fluorine resin,
A resin coated carrier coated with an acrylic resin, a silicone resin or the like is used. Further, the toner of the present invention exhibits excellent performance even when used as a one-component toner.

[0036]

EXAMPLES The present invention will be specifically described below with reference to examples. Parts in the examples represent parts by weight.

Example 1 1 part of Compound No. (1), 5 parts of carbon black, and 94 parts of styrene-ethylhexyl methacrylate copolymer were kneaded by a heating mixer, cooled, and coarsely crushed by a hammer mill. Finely pulverize with a jet mill and then classify 10
12 μm black toner was obtained. This toner was mixed with an iron powder carrier in a weight ratio of 4: 100, and when shaken, the toner was negatively charged, and the charge amount measured by a blow-off powder charge amount measuring device was −38 μc / g. When this toner was used to produce an image on a modified commercial copying machine, a clear image could be obtained even at the initial stage and after copying 10,000 sheets.

Example 2 1 part of Compound No. (6), 5 parts of carbon black, and 94 parts of styrene-ethylhexyl methacrylate copolymer were kneaded by a heating mixer, cooled, and coarsely crushed by a hammer mill. Finely pulverize with a jet mill and then classify 10
12 μm black toner was obtained. This toner was mixed with an iron powder carrier at a weight ratio of 4: 100, and when shaken, the toner was negatively charged, and the charge amount measured by a blow-off powder charge amount measuring device was −22 μc / g. When this toner was used to produce an image on a modified commercial copying machine, a clear image could be obtained even at the initial stage and after copying 10,000 sheets.

Example 3 1 part of Compound No. (6), 5 parts of copper phthalocyanine oil-soluble dye, Spiron Blue 2BNH (product of Hodogaya Chemical Co., Ltd.), and 94 parts of styrene-butyl methacrylate copolymer are mixed by heating. After kneading, cooling and coarse pulverization with a hammer mill. It was finely pulverized with a jet mill and then classified to obtain a blue toner of 10 to 12 μm. This toner was mixed with an iron powder carrier in a weight ratio of 4: 100, and when shaken, the toner was negatively charged, and the charge amount measured by a blow-off powder charge amount measuring device was −25 μc / g. When this toner was used to produce an image on a modified commercial copying machine, a clear image could be obtained even at the initial stage and after copying 10,000 sheets.

Example 4 1 part of Compound No. (8), 5 parts of carbon black, and 94 parts of styrene-ethylhexyl methacrylate copolymer were kneaded by a heating mixer, cooled, and coarsely crushed by a hammer mill. Finely pulverize with a jet mill and then classify 10
12 μm black toner was obtained. This toner was mixed with a silicon coating carrier in a weight ratio of 4: 100, and when shaken, the toner was negatively charged, and the charge amount measured by a blow-off powder charge amount measuring device was −22 μc / g. When this toner was used to produce an image on a modified commercial copying machine, a clear image could be obtained even at the initial stage and after copying 10,000 sheets.

Example 5 1 part of Compound No. (8), 60 parts of magnetic iron powder and 100 parts of styrene-acrylic copolymer were kneaded by a heating mixer, cooled, and coarsely crushed by a hammer mill. It was finely pulverized with a jet mill and then classified to obtain a black toner of 10 to 12 μm. When an image was produced by a modified commercial copying machine using this one-component toner, a clear image quality could be obtained even at the initial stage and after copying 10,000 sheets.

Examples 6 to 11 The results shown in Table 1 were obtained in the same manner as in Example 1 except that the compound shown in Table 1 was used instead of the compound No (1) used in Example 1. .

[0043]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsutoshi Anzai 45 Miyukigaoka, Tsukuba-shi, Ibaraki Hodogaya Chemical Industry Co., Ltd. Tsukuba Research Institute

Claims (1)

[Claims] 1. The following general formula: [Wherein X and Y are independently a hydrogen atom, (Wherein D represents an electron-donating group, R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an acyl group, a cyano group, or a nitro group. ), And (In the formula, D and R ₁ and R ₂ have the same meanings as described above.)
Or, (In the formula, D and R ₁ and R ₂ have the same meanings as described above.)
However, X and Y are not hydrogen at the same time, and Z is a hydrogen atom, an alkyl group or an aryl group. ] A negatively-charged electrophotographic toner containing a compound represented by the following.