JPS60230145A - Electrophotographic blue toner - Google Patents

Abstract

PURPOSE:To obtain a toner having excellent negative triboelectrifiability and a shape deep blue tone by adding a red or purple pigment to a halogen-substd. type Cu-phthalocyanine pigment. CONSTITUTION:A red or purple pigment is added to the halogen-substd. type Cu- phthalocyanine (CuPC) type pigment in a proper amt., such as 0.1-10wt%, and the obtained mixture is used. As said halogen, chlorine is used. This Cl-substd. type CuPC is green, and yellow is converted into a turbid or black color by adding red or purple, i.e., a mixed color of red and blue in a relation of complementary color to yellow, and on the whole, the color tone is turned into deep blue and the coloring is made sharp. Besides, the CuPC pigment is changed to negative triboelectric polarity by substituting Cl. As a result, the obtained electrophotographic blue toner is made deep blue in tone and sharp in coloring and excellent in negative triboelectrifiability by dispersing these pigments into a binder resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a blue toner for electrophotography that has excellent negative chargeability.

(Prior Art) In electrophotography, a black toner whose main components are a black pigment and a fixing resin binder is generally used, but by using a chromatic color as an R material!
− color toners are manufactured. Among these color toners, blue pigments commonly used in blue toners include:

Copper phthalocyanine pigment9. victoria blue rake,
Slenblue etc. are known. Although these pigments are blue in color, each pigment has its own unique color. Among them, phthalocyanine pigments have the most vivid blue color.

In electrophotography, the polarity of the toner to be developed is determined by the charging ability of the photoreceptor used. For example, a photoconductive layer of a photoreceptor made of amorphous selenium, which is commonly used as a photosensitive material, is uniformly charged with positive charges and then exposed for one image to form an electrostatic latent image.

At that time, the charged polarity of the toner is determined to be negative. As mentioned above, the main components of the toner are a pigment and a fixing resin binder. What is the charging polarity of the toner?

It mainly relies on resin binders. If a pigment with a polarity different from the toner's original friction charge polarity is used, for example, the toner as a whole will have a negative polarity, but if the pigment has a relatively strong positive polarity, aging (development) will occur. As the sleeve is operated idly without performing this step, the amount of charge on the toner gradually decreases. For example, a toner made from a conventionally used unsubstituted phthalocyanine with strong positive polarity as a blue pigment exhibits a decrease in negative chargeability of 3 to 5 μC/g or more after aging for 10 hours, resulting in brush marks, This causes trailing, toner scattering, etc. In order to prevent such a decrease in toner charge amount (toner deterioration), it is preferable to use a pigment that has the same polarity as the toner's original frictional charging polarity or a pigment that has relatively neutral charging ability. .

However, the copper phthalocyanine pigment used as the blue pigment is essentially of positive polarity, and is not preferable for negatively charged toners in terms of stability of charging characteristics. Therefore, measures have been taken to shift the benzene ring of the basic skeleton of phthalocyanine to the negative polarity side by substituting a halogen group, such as chlorine. However, due to the substitution of this halogen group, although the polarity becomes negative, the two color tones tend to change from blue to green. As another method, a method of adding a sulfone group to the phthalocyanine ring to form a lake is known, but it is insufficient to shift the frictional charging polarity to the negative polarity side.

Among the above-mentioned pigments, Thren Blue itself is suitable for use in negatively charged toners.

It has the disadvantage of being dark blue in color.

(Object of the Invention) An object of the present invention is to provide a blue toner for electrophotography that has nine clear tones and excellent negative chargeability. Another object of the present invention is to provide a method for changing the green color of chlorine-substituted copper phthalocyanine to blue, which is the original color of phthalocyanine pigments, by adding an appropriate amount of a pigment having a complementary color relationship to the green color. be. Still another object of the present invention is to provide a blue toner for electrophotography that has excellent chargeability maintenance properties.

(Structure of the Invention) The blue toner of the present invention contains a pigment obtained by adding an appropriate amount of a red pigment or a purple pigment to a halogen atom-substituted copper phthalocyanine pigment, thereby achieving the above object.

The halogen-substituted copper phthalocyanine pigment used in the present invention has the following formula (1) (% formula %) where R represents hydrogen or a halogen atom.

The amount of charge of the pigment itself can be arbitrarily adjusted depending on the number of halogen group substitutions in the above formula +1). The polarity of this pigment shifts to the negative electrode side as the number of substitutions increases. Also.

The nine tones tend to change from blue to green as the number of substitutions increases. In the present invention, those having a substitution number of 1 to 4 are particularly preferably used. An example is shown in the table below.

(Left below) The pigments that make up green are blue and yellow. Therefore, if this yellow can be removed, it becomes possible to change the green color of the pigment to blue. To remove yellow, add a certain amount of red, which is a complementary color to yellow, or purple, which is a mixture of red and blue. As a result, the yellow changes to a rich color or black, and the overall color tone becomes a relatively dark blue. As a result, the nine colors become clearer.

Here, the red or purple pigment as a complementary color pigment is preferably contained in an amount of 0.1 to 10% by weight, particularly 2 to 8% by weight, with respect to the halogen-substituted steel phthalocyanine pigment as a blue pigment, and is less than the above range. If the complementary color pigment is too large, the overall color tone will be reddish, and if it is too small, the effects of the present invention cannot be achieved.

For example, two red or purple pigments should be added to the green chlorinated steel phthalocyanine.

There are the following:

Red pigment; Fast Red 28E; Brilliant First Scarlet: Permanent Red 4R; Lysol Red; Pyrazo□Ron Red; Wonting Resod Calcium Salt; Lake Red D; Brilliant Carmino 6
B; Eosin lake; Rhodamine resin 10 B-Ori Zarin lake; Puriri, Antocarmino 3B: Toluidine resin; Permanent red F4RH.

Purple pigment: First Violet B; Methyl Violet Lake; Crystal Violet Lake; Rhodamine B: First Violet B'L.

Further, in the present invention, the total amount of pigment contained in the toner is preferably 1 to 30% by weight based on the fixing resin binder, and other well-known pigments may be used as long as the properties of the toner of the present invention are not affected. It is also possible to use inorganic and organic pigments together.

As the fixing resin binder for toner formation, among various plastic or thermosetting resins, all resins used in this field can be used, for example.

Styrene resin, acrylic resin, olefin resin,
Vinyl resin, saturated polyester resin.

Polyamide resin, alkyd resin, epoxy resin.

Xylene resin and the like may be used alone or in combination of two or more. The blue toner of the present invention may contain various auxiliary agents other than the above-mentioned essential components, if necessary. For example, in order to control the charge polarity of toner particles, charge control agents known per se 7 such as nigrosine base (C15045) can be used.
, oil blank (C126150), and oil-soluble dyes such as Spiron Black.

Naphthenic acid metal salts, fatty acid metal soaps, resin acid soaps, metal-containing azo dyes, etc. are blended. - Silicone oil, low molecular weight olefin resins, various waxes, etc. may be used for the purpose of assisting mold release.

In the electrostatographic reproduction method using the toner of the present invention, the formation of an electrostatic latent image can be carried out in any manner known per se. For example, after uniformly charging a photoconductive layer on a conductive substrate, An electrostatic latent image can be formed by imagewise exposure. Development of the electrostatic latent image is facilitated by mixing the toner with a magnetic carrier and contacting a magnetic brush of the toner with the substrate. The toner image formed by development is transferred onto copy paper, and fixed by bringing this toner image into contact with a heating roll.

(Example) The present invention will be described below with reference to Examples.

Styrene-acrylic copolymer (Prioride ACLi)
100 parts by weight of low molecular weight polypropylene (Viscol 550Pi manufactured by Sanyo Chemical Co., Ltd.), 5 parts by weight of tetrachlorocopper phthalocyanine (Cyanine Pur G-
50ON; manufactured by Yamama Shiki Co., Ltd.) and 0.3 parts by weight of a red monoazo lake pigment (Fast Red 2.8E; manufactured by Yamama Shokuryo Co., Ltd.) were premixed in a Henschel mixer, then melt-kneaded in a two-wheeled extruder and released. It got cold. This kneaded product was roughly pulverized with a cutting mill, finely pulverized with an ultrasonic Die Nodomil PJM-100, and then pulverized with an Alpine classifier.
Average diameter 11 in the range of 5 to 25 μm by cutting less than μm
．． A 5 μm blue toner was obtained. Furthermore, to improve fluidity, hydrophobic silica (R-972, manufactured by Nippon Aerosil Co., Ltd.) 0.
2 weight it% was applied to the surface of the toner using a Henschel mixer. 80g of this blue toner and iron powder carrier (STV
-25T (manufactured by Nippon Tetsuko Co., Ltd.) 720 g was mixed by rotation in a roll mill for 1 hour to prepare a developer, and the amount of blow-off triboelectric charge was measured to be -17.9 μc/g. This developer was placed in a developing machine in a commercially available copying machine (D C-232; manufactured by Sanda Kogyo), and a bias voltage was applied (+200 V).
An aging operation was performed for 10 hours in which the developing machine and drum were idled. The toner concentration after aging was measured by the water washing method and was 9.8%, and the amount of triboelectric charge of the toner was -
It was 17.2 μc/g, and no deterioration of the physical properties of the developer was observed. Furthermore, when copying was performed on an actual machine after aging, a clear blue copy was obtained.

A blue toner was obtained in exactly the same manner as in Example 1 except that Fast Red 28E was removed.
Changes in physical properties before and after the time aging test show that the toner concentration is 1
From 0% to 9.7%, the toner charge amount is -18.0, El
c/g to -17.5 #c/g, with almost no deterioration observed. However, when I made a physical copy after aging, I was able to obtain a copy that was not blue but had a color tone somewhere between blue and green.

Daiarashi■1 Styrene-acrylic copolymer (Prioride ACL
100 parts by weight of low molecular weight polypropylene (Viscol 550P, manufactured by Sanyo Chemical Co., Ltd.), 5 parts by weight of monochlorocopper phthalocyanine (Cyanine Pur G-
50ON; manufactured by Yamama Shiki Co., Ltd.) 6 parts by weight and 0.12 parts by weight of a red monoazo lake pigment (Fast Red 28Ei manufactured by Sanyo Shiki Co., Ltd.) were premixed in a Henschel mixer, then melt-kneaded in a twin-screw extruder and allowed to cool. . This kneaded product was roughly pulverized with a cutting mill, finely pulverized with an ultrasonic jet mill PJM-100, and then pulverized with an Alpine classifier.
The average diameter is 11 in the range of 5 to 25 μm by cutting less than μm.
．． A 5μ blue toner was obtained. Furthermore, to improve fluidity, hydrophobic silica (R-97,2; manufactured by Nippon Aerosil Co., Ltd.)
0.2% by weight was applied to the surface of the toner using a Henschel mixer. 80g of this blue toner and iron powder carrier (STV
-25Ti (manufactured by Nippon Iron Powder Co., Ltd.) 720g in a roll mill
A developer was prepared by time-rotation mixing, and the amount of triboelectrostatic charge measured in the pull-off was -17.2 .mu.c/g. This developer was placed in a developing machine in a commercially available copying machine (DC-232i manufactured by Sanda Kogyo), and a bimass voltage was applied (+200 V).
An aging operation was performed for 10 hours in which the developing machine and drum were idled. The toner concentration after aging was measured by the water washing method and was 9.5%, and the amount of triboelectric charge of the toner was -
It was 14.0 μc/g, and no deterioration of the physical properties of the developer was observed. Furthermore, when copying was performed on an actual machine after aging, a clear blue copy was obtained.

(Effects of the Invention) According to the present invention, as described above, it is possible to supply a blue toner for electrophotography which has two tones of relatively deep blue color, has a clear color tone, and is excellent in negative polarity charging ability.

that's all Applicant: Sanda Kogyo Co., Ltd. Agent: Patent Attorney Shusaku Yamamoto

Claims (1)

[Scope of Claims] 1. A blue toner for electrophotography containing a pigment obtained by adding an appropriate amount of a red pigment, a purple pigment, or a horn pigment to a halogen atom-substituted copper phthalocyanine pigment. 2. The blue toner according to claim 1, wherein the halogen atom is a chlorine atom. 3. The blue toner according to claim 1, wherein the red pigment or the purple pigment is contained in a proportion of 0.1 to 10% by weight based on the phthalocyanine pigment.