JP2806487B2 - Electrophotographic toner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an electrophotographic toner used for developing an electrostatic latent image in electrophotography, electrostatic recording, and the like.

[Conventional technology]

In the electrophotographic image forming process, selenium,
An electrostatic latent image is formed on an inorganic photoreceptor such as a selenium alloy, cadmium sulfide, or amorphous silicon, or an organic photoreceptor using a charge generating agent and a charge transporting agent.
Transfer and fix to paper or plastic film to obtain visible image. The photoreceptor has positive chargeability and negative chargeability depending on its configuration.If the printed area is left as an electrostatic latent image by exposure, develop it with a reverse-charging toner. Is carried out, the toner is developed with the same-charging toner. A toner is composed of a binder resin, a colorant, and other additives. In general, a charge control agent is used to impart desirable triboelectric charging characteristics (charging speed, charging level, charging stability, etc.), aging stability, and environmental stability. Is used. The characteristics of the toner are greatly affected by the charge control agent. Negatively chargeable toner is used when developing with a reverse chargeable toner using a positively chargeable photoreceptor and when performing reversal development using a negatively chargeable photoreceptor. Agent is used.

Further, in the case of a color toner, a light-colored, preferably colorless, charge control agent which does not affect the hue is required. These light-colored or colorless charge control agents include:
For example, JP-B-55-42752, JP-A-61-69073, JP-A-61-69073
Metal complex salts of hydroxybenzoic acid derivatives described in JP-A-221756, metal salts of aromatic dicarboxylic acids described in JP-A-57-111541, JP-A-61-141453, JP-A
Metal complex salt compounds of anthranilic acid derivatives described in 62-94856 and the like, organic boron compounds described in USP-4767688, JP-A-1-306681 and the like, and biphenol compounds described in JP-A-61-3149 and the like. . However, these charge control agents are chromium compounds that are a concern for environmental issues, or those that cannot be completely colorless, or have a low charge-providing effect, have many reverse-charged toners, or have a dispersibility or There were drawbacks such as poor stability of the compound, and none of them had satisfactory performance as a charge control agent.

[Problems to be solved by the invention]

The present invention uses a colorless aluminum compound having high stability as a compound as a charge control agent, the charge control agent has good dispersibility in a binder resin, has good charge stability by friction, and has high image quality. The purpose of the present invention is to provide a toner that constantly provides an image stably.

[Means for solving the problem]

The present inventors have good dispersibility with the binder resin,
A colorless stable compound capable of imparting good charging characteristics to the toner has been found, and the use of this compound as a charge control agent has led to the invention of an excellent toner.

That is, the present invention provides the following general formula (Wherein, R ₁ represents an alkyl group, a cycloalkyl group or an aralkyl group, R ₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, a hydroxyl group or an alkoxy group, and n represents 2 or An integer of 3, and M represents a hydrogen atom, an alkali metal, ammonium, an aliphatic ammonium, or an alicyclic ammonium ion.)

The present invention basically comprises a binder resin, a colorant and the compound represented by the general formula (1) according to the present invention. A method for producing the toner of the present invention is as follows. Kneading under the melting of the binder resin by kneading, after cooling, coarse pulverization, fine pulverization, classification, a method of dissolving these mixtures in a solvent, atomization by spraying, drying, classification and a method of obtaining by suspension A colorant or a compound represented by the general formula (1) is dispersed in the monomer particles, and
There is a method obtained by a polymerization method and the like.

Polystyrene, styrene-
Methacrylic acid ester copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, acrylic resin, styrene-maleic acid copolymer, olefin resin,
Polyester, epoxy resin, polyurethane resin, polyvinyl butyral and the like can be used alone or in combination.

As a colorant, carbon black is generally used for a black toner, and the following colorants can be used for a color toner. As a yellow colorant,
CI Pigment Yellow 1, CI Pigment Yellow 5, CI
Azo organic pigments such as CI Pigment Yellow 12, CI Pigment Yellow 17 or the like, or inorganic pigments such as loess or oil-soluble dyes such as CI Solvent Yellow 2, CI Solvent Yellow 6, CI Solvent Yellow 14, CI Solvent Yellow 19, etc.
Examples of the magenta colorant include azo pigments such as CI Pigment Red 57 and CI Pigment Red 57: 1, xanthene pigments such as CI Pigment Violet 1 and CI Pigment Red 81,
CI pigment blue 1 such as CI Pigment Red 87, CI Butt Red 1 and CI Pigment Violet 38; oil-soluble dyes such as CI Solvent Red 19, CI Solvent Red 49 and CI Solvent Red 52; Phthalocyanine pigments such as CI Pigment Blue 15, CI Pigment Blue 17 or CI Solvent Blue 25, CI Solvent Blue
Known colorants such as oil-soluble dyes such as 40 and CI Solvent Blue 70 can be used.

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

In addition, the toner may be used as an additive to protect the photoreceptor / carrier, improve the fluidity of the toner, adjust the thermal, electrical, and physical properties, adjust the resistance, adjust the softening point, and improve the fixability. Silica, metallic soap, fluorosurfactant, 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, the carrier may be a fine glass bead, an iron powder, a ferrite powder, a binder type carrier of resin particles in which magnetic particles are dispersed, or a polyester-based resin or a fluorine-based 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 shows excellent performance even when used as a one-component toner.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to examples. Parts in Examples are parts by weight.

Example 1 1 part of the aluminum compound of Compound Example (1), 5 parts of carbon black, and 94 parts of a styrene-ethylhexyl methacrylate copolymer were kneaded by a heating and mixing apparatus, and after cooling,
It was coarsely ground with a hammer mill. After finely pulverizing with a jet mill, classification was performed to obtain a black toner of 10 to 12 μm. This toner was mixed with an iron powder carrier at a weight ratio of 4 to 100 and shaken. As a result, the toner was negatively charged, and the charge was -15 μc / g as measured by a blow-off powder charge meter.
When an image was produced with a modified commercial copying machine using this toner, a clear image was obtained at the initial stage and after 10,000 copies.

Example 2 1 part of the aluminum compound of Compound Example (2), 5 parts of carbon black, and 94 parts of a styrene-ethylhexyl methacrylate copolymer were kneaded by a heating and mixing apparatus, and after cooling,
It was coarsely ground with a hammer mill. After finely pulverizing with a jet mill, classification was performed to obtain a black toner of 10 to 12 μm. This toner was mixed with an iron powder carrier at a weight ratio of 4 to 100, and when shaken, the toner was negatively charged. The charge amount was −14 μc / g as measured by a blow-off powder charge amount measuring device.
When an image was produced with a modified commercial copying machine using this toner, a clear image was obtained at the initial stage and after 10,000 copies.

Example 3 1 part of aluminum compound of compound (1), copper phthalocyanine
Spiron Blue 2BNH, an anine-based oil-soluble dye 5 copies,
Heat and mix 94 parts of styrene-butyl methacrylate copolymer.
After kneading with a mixing device and cooling, coarsely pulverize with a hammer mill.
Was. Finely pulverized with a jet mill, then classified and 10 to 12 μm
Blue toner was obtained. Four pairs of this toner and iron powder carrier
After mixing at a weight ratio of 100 and shaking, the toner became negative
And measured with a blow-off powder charge meter.
The charge amount was −18 μc / g. Modified using this toner
When an image was produced with a commercial copier, the initial and 10,000 copies were copied.
After that, images with clear image quality could be obtained.

Example 4 1 part of the aluminum compound of Compound Example (3), 5 parts of carbon black, and 94 parts of a styrene-ethylhexyl methacrylate copolymer were kneaded by a heating and mixing apparatus, and after cooling,
It was coarsely ground with a hammer mill. After finely pulverizing with a jet mill, classification was performed to obtain a black toner of 10 to 12 μm. 4 to 100 of this toner with silicone resin coated carrier
And the toner was negatively charged when shaken, and the charge amount was −15 μc / g as measured by a blow-off powder charge amount measuring device. When an image was produced using a modified commercial copying machine using this toner, clear images were obtained at the initial stage and after 10,000 copies.

Examples 5 to 10 Except that the aluminum compound shown in Table 1 was used instead of the aluminum compound of the compound example (1) of Example 1,
By performing the same operation as in Example 1, the results shown in Table 1 were obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-309072 (JP, A) JP-A-64-10261 (JP, A) JP-A-63-237065 (JP, A) JP-A-63-1987 208865 (JP, A) JP-A-2-190869 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 9/097

Claims (1)

(57) [Claims] 1. The following general formula (Wherein, R ₁ represents an alkyl group, a cycloalkyl group or an aralkyl group, R ₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, a hydroxyl group or an alkoxy group, and n represents 2 or An integer of 3, and M represents a hydrogen atom, an alkali metal, ammonium, an aliphatic ammonium or an alicyclic ammonium ion.) An electrophotographic toner comprising: