JPH02196247A - cyan toner - Google Patents

Abstract

PURPOSE:To obtain sharp copies which have sufficient image densities and less fogging by incorporating a binder resin, compd. classified to C.I. pigment blue-15 and specific compds. into the toner. CONSTITUTION:Specific >=2 kinds of the compds. are incorporated into the binder resin in order to obtain the cyan toner having good spectral reflection characteristic, transparency and color mixability, low environmental dependency and excellent electrostatic chargeability and durability. Namely, two kinds of blue coloring agents are used as the essential constitution of the cyan toner and are incorporated at 0.1 to 20wt.% therein. Since the compd. classified to the C.I. pigment blue-15 exhibits a highly reddish blue color, the use of this compd. alone as the coloring agent of the cyan toner is not preferable in terms of hue and there is a disadvantage that the fogging is generated if the development is repeatedly executed by using the toner contg. this compd. The compd. expressed by the formula I is added to the toner to develop the bright cyan color having no redness in order to overcome this disadvantage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a cyan toner, particularly a negatively chargeable cyan toner for color electrophotography.

[Conventional technology]

Electrophotography method is US Patent No. 2297691, Special Publication No. 41
As disclosed in various publications such as Japanese Patent Publication No. 23910 and Japanese Patent Publication No. 43-24748, generally an electrostatic latent image is formed on a photoreceptor containing a photoconductive material by various means, and then the latent image is The image is developed as a toner powder image, and after the cough powder image is transferred to a paper or the like as necessary, it is fixed by heating, pressurization, solvent vapor, or the like.

In addition, in recent years, the electrostatic latent image of the document is formed by exposing it to spectral light, and this is developed with color toner of each color to obtain a colored copy image, or the copy images of each color are superimposed to form a full-color copy image. A color copying method for obtaining a copied image has been put into practical use, and color toners such as yellow magenta and cyan, which are made by dispersing dyes and/or pigments of various colors in a binder resin, have been produced.

The toner used is particles made by dispersing dyes and pigments in a resin such as polyester and pulverizing them into particles of approximately 1 to 30 μm.Such toners are made using a carrier material such as glass peas, iron powder, or fur. It is used in combination with

[Problem that the invention seeks to solve]

Color toners are required to have the following characteristics, similar to the commonly used black toner.

- Excellent triboelectric properties.

・Characteristics do not change significantly depending on the environment such as temperature and humidity, that is, there is little environmental dependence.

・Less deterioration due to repeated continuous use.

Furthermore, the following characteristics unique to color toners are also essential.

・Spectral reflection characteristics must be good in order to faithfully reproduce the original.

- Robust against light and heat, and does not fade even if left unused.

・High transparency for multicolor overlay.

- Good color mixing properties with toners of other colors.

However, if priority is given to hue, transparency, etc., the materials that can be used are limited, and it may not be possible to fully satisfy chargeability, durability under continuous use, etc.
At present, there is a constant demand for improvements in color toners.

[Means for solving problems]

The present invention was made based on these circumstances, and
The purpose is to provide a cyan toner that has good spectral reflection characteristics, transparency, and color mixing properties, is less dependent on the environment, and is also excellent in chargeability, durability, and the like.

Therefore, the present inventors conducted extensive studies to achieve the above object, and found that a cyan toner that satisfies the above object can be obtained by incorporating two or more specific compounds into the binder resin.The present invention is based on the present invention. reached.

That is, the gist of the present invention is that the binder resin, C, I.

The cyan toner is characterized by containing a compound classified as Pigment Blue 15 and a compound represented by the following general formula (I).

[In the formula, X1 to X4 are each a hydrogen atom or (in the formula, R
1 and R- each represent an alkoxy group having 1 to 5 carbon atoms, and n represents any integer of 0 to 4. ) represents.

However, except for the case where all of x I and x 4 are hydrogen atoms (,) [Operation] The present invention will be described in detail below.

First, two types of blue colorants are listed as essential constituent components of the cyan toner of the present invention.

Compounds classified as C,1, Pigment Blue 15 are:
A specific example of a copper phthalocyanine pigment is Hostaperm Blue AR (Hoechst
) Heliogen Blue LGB
(BASF) Sanyo Cyanine B
lue KG (Dainiehi)
Cyanine Blue B (Dainichiseika) Su
mit, omo Cyanir+e Blue LB
C Sumitomo Chemical Phthaloeyanine Blue
e SG (Tokyo Ink) etc.These are
0.1 to 20 wt% based on the resin, more preferably 0.1 to 20 wt%.
The content is preferably in the range of 5 to 1Qwt%.

This compound classified as C, 1, Bigmen I/Blue 15 exhibits a strong reddish blue color, so it is not preferred from the viewpoint of hue to be used alone as a coloring agent for cyan toner. Furthermore, toners containing this compound have the disadvantage that fogging occurs when repeated development is performed.

This is presumed to be due to an increase in uncharged or weakly charged portions in the toner.

In the present invention, the above C,1, Pigment Blue 1
In order to eliminate the drawbacks of toners that use only compounds classified as 5 as colorants, one of the requirements is to add the compound represented by -Funenin (I) above, and by mixing them, redness can be reduced. This makes it possible to develop a clear cyan color. In addition, the compound represented by general formula (I), when contained in a resin, uniformly charges the toner to a negative polarity that is stable against changes in humidity. It is extremely effective in preventing fog caused by generation. - X l in the sailor (1),
Preferred specific examples of the substituent represented by X 4 include the following.

The copper phthalocyanine compound represented by general formula (1) is
)Cl, except for those in which all the substituents represented by It is more preferable to use a mixture thereof, and the content in the toner is 0.1 to 20 wt%, based on the resin.
The content is preferably 0.5 to 10 wt%.

On the other hand, the binder resin to be contained in the cyan toner of the present invention can be selected from a wide range including known ones. Specifically, styrene resins such as polystyrene, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, and styrene-butadiene copolymer, as well as polyester resin, epoxy resin, phenol resin, and coumaron resin. , chlorinated paraffin, xylene resin, vinyl chloride resin, polyethylene, and polypropylene, and two or more of these resins may be used in combination as appropriate.

Among these, it is advantageous to use styrene resins, polyester resins, or epoxy resins, and among these, polyester resins synthesized from diols and polyhydric carboxylic acids and having a softening point of 70 to 150°C are particularly preferred. Such polyester resins are excellent in terms of transparency and gloss, and are particularly suitable for use in toners for full-color electrophotography where multiple transfers are performed. The polyester resin will be explained below.

25 ethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1. 4-butanediol, neopentyl glycol, 1,4-butynediol, 1,4-bis(hydroxymethyl)cyclohexane, bisphenol A1 hydrogenated bisphenol A1 polyoxypropylene (2,2)-2,2-bis(4 -hydroxyphenyl)propane, polyoxypropylene (3
゜3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene (2,0)-2゜2-bis(
4-Hydroxyphenyl)propane, polyoxypropylene (2,Cj> ~2,2-bis(4-hydroxyphenyl)propane moxibustion bond Upper left major 2nd and minor spots (divalent carboxylic acid) Maleic acid, fumaric acid, phthalate acids, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, cepatic acid, malonic acid, oxalic acid, or their acid anhydrides or esters with lower alcohols (trivalent or higher carboxylic acids), benzene-1, 2,4-1-dicarboxylic acid, cyclohexane-1,2,1-tricarboxylic acid, naphthalene-2,5
, 71-dicarboxylic acid, tetra(carboxymethyl)methane, octa-1,2゜7.8-tetracarboxylic acid and these acid anhydrides. ) Bisphenol A Example of a polyester resin with a softening point of 120°C synthesized from fumaric acid (
B) Bisphenol A Example of a polyester resin with a softening point of 112°C synthesized from terephthalic acid (
C) Example of polyester resin synthesized from isophthalic acid with a softening point of 93°C (D
) An example of a polyester resin with a softening point of 101°C synthesized from terephthalic acid (
E) Polyester synthesized from benzene terephthalate-1,2,4-1-dicarboxylic acid with a softening point of 132°C. However, these polyester resins easily cause blocking if their softening point is lower than 70°C. Therefore, there is a drawback in storage stability, and if the softening point exceeds 150° C., fixing performance deteriorates, and furthermore, transparency and color mixing properties are also impaired, which is not preferable. Therefore, the softening point is always between 70 and 150.
It must be within the range of °C.

The softening point of polyester resin is JIS 2207-
It was measured using the environmental method described in 1980.

The cyan toner of the present invention has good negative chargeability, but if necessary, it may further contain a known negative charge control agent such as a metal complex of salicylic acid or alkylsalicylic acid with Cr, Zn or /1. 0.5~5w in toner
It may be contained within the range of t%.

Further, in the present invention, a fluidity improver such as colloidal silica may be added to the toner in an amount of about 0.01 to 3 wt%.

In addition, cleaning aids such as metal stearate may be added as appropriate.

The cyan toner of the present invention can be manufactured by any conventionally known cyan toner manufacturing method, and examples of the intra-film manufacturing method include the following.

First, the resin and the compound represented by general formula (1) (additives such as a charge control agent may be added depending on the case) are uniformly mixed using a ball mill, V-type mixer, S-type mixer, Henschel mixer, etc. dispersed into

Next, the dispersion is melt-kneaded using a double-arm kneader, pressurized kneader, or the like. The mixture is pulverized using a pulverizer such as a hammer mill, shed mill, or ball mill, and the resulting powder is further classified using an air classifier or the like.

The toner of the present invention is preferably mixed with a carrier and used as a two-component developer, but it can also be used as a touchdown type one-component developer.

As the carrier, conventionally known carriers such as iron powder, ferrite powder, magnetite powder and the like having a particle size of about 50 to 2008 parts can be used. Moreover, those whose surfaces are coated with silicone resin, acrylic resin, fluororesin, or a mixture of these resins can also be suitably used.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to the following examples unless it exceeds the gist of the invention.
"Parts" shall mean "parts by weight j."
The copper phthalocyanine compound used as a material in each example and comparative example has approximately 18 2-substituted and 4-substituted compounds.
It is a mixture containing at a molar ratio of 1.

Implementation 1↓ Polyester resin example (A) 100 copies Host
aperm Blue AR 3 parts The above materials were melt-kneaded using a hot roll mill, cooled, and coarsely ground using a hammer mill, and then finely ground using an air jet type pulverizer. The obtained fine powder was classified to select particles with a particle size of 5 to 20 μm, and 0.5 wt of hydrophobic silica R972 (trade name, manufactured by Nippon Aerosil) was added to the selected toner particles using a Henschel mixer. % was added externally to obtain a cyan toner.

To 3 parts of this toner, 97 parts of carrier (ferrite powder coated with silicone resin and having an average particle diameter of about 100 μm) was mixed in a blender to prepare a developer. The charge amount of this developer by the blow-off method was -16 μC/g.

Using this developer, we conducted a continuous copying test using a commercially available dry copying machine that uses selenium as a photoreceptor, and the results showed that even after 20,000 copies, there was no fog, the spectral reflection characteristics were very good, and the copies were clear in cyan color. was gotten. Also,
The charge amount of the developer at this time was also stable at -15 IjC/g, and it was found that the chargeability and durability were also excellent.

Furthermore, when full-color copying was performed using a combination of yellow toner using an ab-based dye and magenta toner using an anthraquinone-based dye, a clear color image with extremely good color reproducibility was obtained, and the areas corresponding to black in the original were obtained. has been reproduced in pure black.

S1111 Polyester resin example (A) 100 parts 5any
o Cyanir+e Blue KG 4
Example 1 except that the materials used were as described above.
A developer was manufactured in exactly the same manner as described above, and a continuous copying test was conducted. Even after 2,000 copies were printed, extremely clear cyan copies were obtained without a decrease in image density or an increase in fog.

Further, when full-color copying was performed using this developer in combination with the same yellow toner and magenta toner used in Example 1, a clear color image with extremely good color reproducibility was obtained, which corresponded to the black of the original. Parts have been reproduced in pure black.

1 application 1 Polyester resin example (C) 100 parts Host
Aperm Blue AR5 copies A developer was manufactured in exactly the same manner as in Example 1 except that the materials used were as described above, and a continuous copying test of 20,000 sheets was conducted, resulting in copies exhibiting an extremely clear cyan color without fogging. I got it.

Furthermore, when this developer was combined with the same yellow toner and magenta toner used in Example 1 to perform full-color copying, a clear color image with extremely good color reproducibility was obtained, and the portions of the original that corresponded to black were obtained. has been reproduced in pure black.

Example of applied polyester resin (D) 100 parts Dain
ichi Cyanins Blue B 5
Part: Copper phthalocyanine compound having the above-mentioned substituent (a) 2 parts A developer was produced in exactly the same manner as in Example 1, except that the materials used were as described above. 8
I brought it to 5% RH) and did a continuous live-action test, but
Even after copying 20,000 copies, extremely clear cyan copies without fogging were obtained.

A developer was produced in exactly the same manner as in Example 1, except that the copper phthalocyanine compound was removed from the materials used in the above example, and using this developer, continuous When we conducted a live-action test, we were able to initially obtain clear copies (blue with a strong reddish tint). However, after copying 20,000 copies, the copies were blurred with a lot of fog. At this time, when the charge distribution of the developer was examined, it was found that an extremely large amount of uncharged and weakly charged toner was generated.

When the developer was used in combination with the same yellow toner and magenta toner as used in Example 1 to perform full-color copying, the resulting full-color image had poor color reproducibility in intermediate colors and was somewhat unclear. The part corresponding to black became a dull black.

Comparison 1: A developer was produced in the same manner as in Example 1, except that the materials used in the above Example were changed as described below, and Hostaperm Blue AR was removed. When a live copying test was carried out in exactly the same manner as in Example 1, 20,000 continuous copies could be made without any particular problem.

However, compared to the cyan copy obtained in Example 1, the saturation was slightly inferior, resulting in an overall dark tone.

When this developer was combined with the same yellow toner and magenta toner used in Example 1 to perform full-color copying, the resulting full-color image had poor color reproducibility of intermediate colors and was somewhat unclear, and the black of the original The area corresponding to the color became dull and dark.

〔Effect of the invention〕

The cyan toner of the present invention enables clear copies with sufficient image density and little fog, is less dependent on the environment, has excellent durability, and, as a color toner, has excellent spectral reflection characteristics, transparency, and gloss. It is.

Claims (1)

[Claims] 1) Binder resin, C.I. I. A cyan toner characterized by containing a compound classified as Pigment Blue 15 and a compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) (In the formula, X^1 to X^4 are each hydrogen atoms, or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1 and R^ 2 each represents an alkoxy group having 1 to 5 carbon atoms, and n represents any integer of 0 to 4.) However, the case where all of X^1 to X^4 are hydrogen atoms is excluded. (2) The cyan toner according to claim 1, wherein the binder resin is a polyester resin synthesized from a diol and a polyhydric carboxylic acid and has a softening point of 70 to 150°C.