JPS61112158A - Dry process color toner - Google Patents

Abstract

PURPOSE:To obtain a toner which eliminates the decrease in transparency owing to the aggregation of a copper phthalocyanine pigment and prevents the hiding of the color of an under layer when superposed by incorporating the copper phthalocyanine pigment and the metallic salt of an org. carboxylic acid into a binder resin. CONSTITUTION:The toner incorporated with 1-20pts.wt. copper phthalocyanine pigment by 100pts.wt. binder resin of the dry process color toner and 1-200pts. wt. Zn salt of preferably a stearic acid, diabietic acid, etc. as org. carbon by 100pts.wt. copperphthalocyanine pigment is prepd. The toner obtd. in such a manner contains less secondary aggregate of the copper phthalocyanine pigment and has good transparency of the toner when superposed on the other color toner. Since the toner does not hide the color of the under layer, the image having the excellent color reproducibility of an original is formed. The color toner which does not deteriorate in characteristic even in the stage of copying for a long period of time is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to color toners for developing electrostatic images.

[Conventional technology]

Cascade development, magnetic brush development, and the like are known as methods for developing electrostatic images formed by electrophotography or electrostatic recording.

These developing methods use a developer consisting of toner and carrier, and apply a charge of a different polarity to the electrostatic charge image to the toner by frictional charging between the toner and the carrier, and make the toner adhere to the latent image and visualize it.

In addition, in order to obtain a color image, the original is exposed through a color separation filter, and the electrostatic charge image formed is then developed multiple times with color toner corresponding to the complementary color of the filter, and the toner images are superimposed. It is a multicolor image.

In color reproduction by multicolor superimposition in electrophotography, etc., it is necessary that the spectral reflection characteristics of the toner be closer to the ideal value, and that the toner be transparent so that the color of the underlying layer is not hidden when superimposed. It is a condition.

Conventionally, steel phthalocyanine dyes and pigments, which are inexpensive and have good spectral reflection characteristics, have often been used as colorants for cyan toners. However, multicolor images obtained using toners in which steel phthalocyanine dyes and pigments are dispersed in binder resins are more opaque than cyan toners.
The lower layers of yellow and magenta were hidden and colors could not be faithfully reproduced. In order to obtain a transparent cyan toner, the steel phthalocyanine dye and pigment, which is a coloring agent, must theoretically be decoagulated to a size of 172 or less of its maximum absorption wavelength λamax. However, copper phthalocyanine-based dyeing is not possible using the melt mixing method using a roll mill or Nigu, which is generally used in the production of dry toners, or the spray drying method in which dry granulation is performed from a solution state. Further, the disadvantages caused by the presence of a large amount of secondary aggregates of copper phthalocyanine dyes and pigments in the binder resin not only deteriorate the color reproducibility but also significantly shorten the life of the developer. In other words, secondary aggregates of liberated copper phthalocyanine dyes and pigments in the toner surface layer contaminate the inner surface during long-term copying, significantly impairing the charging properties of the developer, and causing blurring and background in the copied image. This causes dirt and early deterioration of the developer.

[Problems to be Solved by the Invention] In view of these conventional drawbacks, the present invention solves the problem of concealment during multi-color superimposition caused by the opacity of the toner due to secondary aggregates of copper phthalocyanine dyes and pigments in the binder resin. To provide a dry cyan toner which does not cause the payload effect, does not cause deterioration of the chargeability of a developer due to contamination of the carrier surface, has excellent color reproducibility, and can withstand long-term copying.

[Means and effects for solving the problems] The object of the present invention can be achieved by a dry cyan toner characterized by containing a copper phthalocyanine dye and pigment and a metal salt of an organic carboxylic acid in a binder resin. can.

In the dry cyan toner of the present invention, zinc stearate or zinc diabietate can be preferably used as the metal salt of the organic carboxylic acid. The dry cyan toner of the present invention, which contains a copper phthalocyanine dye and pigment and a metal salt of an organic carboxylic acid in the binder resin, has high transparency and does not cause a hidden effect when layering multiple colors, and is almost equivalent to the original. It exhibits color reproducibility of T0, and no deterioration of the developer is observed even during long-term copying.

Examples of the cyanocyanine dyes and pigments used in the present invention include β-copper phthalocyanine pigments represented by C11 and Pigment Blue 15;

Solma@nt Blue 25 is a sulfonated copper phthalocyanine dye treated with amine in aluminum, C, I
.

Examples include sulfonated copper phthalocyanine typified by Direct Blue 136.

The copper 7 talocyan dye and pigment according to #Jζζ of the present invention is used in an amount of 1 to 20 parts by weight, preferably 3 to 15 parts by weight, based on 1003 it parts of the binder resin. The metal salt of an organic carboxylic acid is used in an amount of 1 to 200 parts by weight, preferably 3 to 150 parts by weight, based on 100 parts by weight of the copper 7-lysyanine dye and pigment. If the metal salt of organic carboxylic acid is less than 1 part by weight per 100 parts by weight of the copper phthalocyanine dye and pigment, the transparency of the toner will decrease and the life of the developer using this toner will be shortened, which is not preferable. .

If the amount is 200 parts by weight or more, the excess metal salt of the organic carboxylic acid decreases the transparency of the toner, which is not preferable.

As the binder resin of the toner used in the present invention, natural and synthetic resins, rubbers or waxes which exhibit adhesive properties under the application of heat or pressure are used.

Useful natural resins include balsam resin, rosin, shellac, and copal, and these natural resins can be modified with one or more of the following vinyl resins, acrylic resins, alkali resins, phenolic resins, etc. Can be done. Synthetic resins include vinyl chloride resin, vinylidene chloride resin,
Vinyl resins such as vinyl acetate resins, vinyl acetal resins such as polyvinyl butyral, or vinyl ether polymers: Acrylic resins such as polyacrylic esters, polymethacrylic esters, acrylic acid copolymers, and methacrylic acid copolymers; polyethylene Olefin resins such as , polypropylene, polystyrene, and styrene copolymers:
Polyamide resins such as nylon-12, nylon 6, polymerized fatty acid-modified polyamides; polyesters such as polyethylene tere-7-talate/iso-7-talate, polytetramethylene terephthalate/iso-7-talate; 7-talic acid resins;
Alkyd resins such as maleic acid resins; phenol formaldehyde resins; ketone resins; coumaron-indene resins; amine resins such as urea-formaldehyde resins, melamine-formaldehyde resins, etc. can be used, and these synthetic resins can be used in combinations of two or more types. Can also be used in combination.

Examples of natural or synthetic rubber substances include natural rubber, chlorinated rubber, cyclized rubber, polyimbutene, ethylene-propylene rubber, ethylene-propylene-diene rubber, polybutadiene, butyl rubber, styrene-butadiene rubber, and acrylonitrile-butadiene rubber. be able to.

The coating material may contain a charge control agent such as a quaternary ammonium salt or a colorless dye for the purpose of charge control.

The toner of the present invention can be mixed with carrier particles to form a developer, or the toner alone can be used as a developer without using carrier particles. The carrier particles to be mixed with the toner should preferably have an average particle size that is approximately the same as or larger than the toner (up to 500 μm is suitable.As the carrier particles, for example, glass particles or Single metals such as iron, nickel, cobalt, etc.
Alternatively, alloy particles or particles in which fine magnetic powder is dispersed in a solid resin may be used, and these may be used without coating the inner layer (or by coating with various resins or compounds).

Various additives may be further added to the toner of the present invention. These additives include charge control agents, fluidity modifiers, toner filming inhibitors, and the like.

Examples include colloidal silica, titanium oxide, alumina oxide, and the like.

〔Example〕

The present invention will be specifically explained below using Examples and Comparative Examples.

Example 1 Resin 10 is a copolymer of 60 parts styrene and 40 parts n-butyl methacrylate with a softening point of 130"0.
0 parts by weight and 0 parts by weight Ogen Blue D7072D (
5 parts by weight of BASF Steel Co., Ltd. 7 Polycyanine Pigment) and 0.5 parts by weight of zinc stearate were mixed, melt mixed in a heated roll mill, cooled and pulverized to obtain a toner having an average diameter of about 13 μm.

A developer is prepared by mixing 5 parts by weight of this toner with 95 parts by weight of iron powder gearia having a particle size of about 74 to 125 μm,
When a positive electrostatic image formed on a selenium-based photoreceptor was developed using conventional electrophotographic method I, a positive copy image was obtained, and this image had no blurring or background stains. Further, even after 100,000 copies were made, the copied image maintained a uniform image density and there was no background stain.

Also, when I took a superimposed image of toner using an XC-6500 copier (Fuji Xerox Co., Ltd.), I found cyan toner l.
No hidden pay effect was observed.

Example 2 Resin 10 is a copolymer of 60 parts styrene and 40 parts n-butyl methacrylate and has a softening point of 130°C.
0 parts by weight and Neoxapon Blua 807 (BA
3 parts by weight of SF steel phthalocyanine oil-soluble dye) and 1 part by weight of zinc stearate were mixed and mixed with ffI in a pressure kneader.
After cooling and pulverizing, a toner having an average diameter of about 13 μm was obtained.

A developer was prepared by mixing 3 parts by weight of this toner with 97 parts by weight of Yaria in ferrite having a particle size of approximately 74 to 125 μm, and a copy test similar to that in Example 1 was conducted.
Even after 100,000 copies were made, uniform image density was maintained and there was no background stain. In addition, although a superimposed image of the toner was taken using an XC-6500 copying machine, no concealment effect due to the cyan toner was observed.

Example 3 100 parts by weight of a copolymer of 93 parts styrene and 7 parts butadiene with a softening point of 100° C. and Fmstogen
51 parts of Blue BB (manufactured by Dainippon Inchu Co., Ltd., sulfonated copper phthalocyanine) and 5 parts by weight of zinc diabietate were mixed, melt-kneaded in a hot roll mill, cooled, and pulverized to have an average diameter of about 13 μm. I got the toner.

A developer is prepared by mixing 5 parts by weight of this toner with 95 parts by weight of an iron powder carrier having a particle size of about 74 to 125 μm,
When a copy test was conducted in the same manner as in Example 1, 10
Uniform image density was maintained even after 10,000 copies were made, and there was no background stain. Further, when a superimposed image of the toner was taken using an XC-6500 copying machine, no concealment effect due to the cyan toner was observed.

Example 4 Softening point 1 composed of 50 parts styrene, 35 parts n-butyl methacrylate and 15 parts polyester
100 parts by weight of resin and Neogapon B at 20°C
Mix 5 parts by weight of lue 807 with 0.4 parts by weight of zinc stearate and 3 parts by weight of zinc cyabinitate, melt and cross-mix with a heated roll mill, cool and crush to about 13 μm.
A toner having an average diameter of T was obtained.

A developer is prepared by mixing 7 parts by weight of this toner with 93 parts by weight of an iron powder carrier having a particle size of about 74 to 125 μm,
A copy test similar to that in Example 1 was conducted, and even after 100,000 copies, uniform image density was maintained and there was no background stain. Further, when a superimposed image of the toner was taken using an XC-6500 copying machine, no concealment effect due to the cyan toner was observed.

Comparative Example 1 A toner was prepared in the same manner as described in Example 1 except for zinc stearate, and a copy test was conducted in the same manner. The dirt in the background is starting to become noticeable. Also, when a superimposed toner image was taken using an XC-6500 copying machine, the other colors in F1 were significantly obscured by the upper layer of cyan toner, resulting in a color different from that of the original.

〔Effect of the invention〕

The present invention provides a dry cyan toner containing a steel phthalocyanine dye and pigment and a metal salt of an organic carboxylic acid in a binder resin. It does not hide other colors in the underlying layer when superimposed, has excellent color reproducibility of originals, and does not deteriorate even during long-term copying.

Claims (1)

[Scope of Claims] 1. A dry cyan toner characterized by containing a steel phthalocyanine dye and pigment and a metal salt of an organic carboxylic acid in a binder resin. 2. The dry cyan toner according to claim 1, wherein the metal salt of organic carboxylic acid is zinc stearate. 3. The dry cyan toner according to claim 1, wherein the metal salt of organic carboxylic acid is zinc diabietate.