JPH0675212B2 - New electrophotographic metallic toner - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metallic toner used in electrophotography.

(Prior Art) In electrophotography, a charge image formed on the surface of a photoconductor is developed with a toner having a detecting property and a fixing property, the developed toner image is transferred onto a transfer paper, and then fixed. Then, an image is formed. Various black to color toners are known as electrophotographic toners used for this purpose.
No toner having a metallic color tone is known yet.

(Problems to be Solved by the Invention) On the other hand, in the field where decorativeness is required, there are cases where an electrophotographic copy or a printed matter of an image with a metallic color tone is required. Could not adapt to.

The most common idea when producing a metallic toner is to mix a metal powder having a relatively large particle size such as metal aluminum powder into a toner together with a colorant. Is very difficult, and there is a great risk of causing a dust explosion or the like when forming a toner.

Therefore, an object of the present invention is to provide a toner having a metallic color tone applicable to electrophotography.

Another object of the present invention is to provide an electrophotographic toner which is easily manufactured without the above-mentioned dangers and which has a metallic color tone and is excellent in decorative feeling.

Still another object of the present invention is to provide a metallic toner having excellent electrophotographic properties.

(Means for Solving Problems) The present inventors have solved the above-mentioned problems by including a plate-shaped structure of purine or a derivative thereof in a toner, and have electrophotographic properties and decorative effects. It has been found that an excellent metallic toner is provided.

(Function) As the purine or its derivative component used in the present invention,
As such a plate-like structure is used.

That is, when a toner obtained by dispersing the plate-like structure in a resin medium is fixed on the paper, a fixing pressure forms a layered structure in which the structures are arranged substantially parallel to the paper surface.

Light incident on a fixed image having such a layered structure is regularly reflected in the multiple thin films of the above structure to enhance the metallic gloss.

Thus, according to the present invention, it is possible to provide a fixed image having an extremely decorative color tone in combination with the color tone of the colorant contained in the toner.

Further, the plate-like structure used in the present invention is composed of a chemically stable purine or derivative thereof, and as a result, troubles such as dust explosion at the time of toner production which occurs when using metal powder is eliminated. There is an advantage that

Further, since this pigment is electrically insulative and insensitive to humidity and the like, there is an advantage that the electrophotographic characteristics of the toner are not impaired at all.

(Preferred embodiment of the invention) Purine or derivative thereof The purine used as a blending component of the toner in the present invention is a heterocyclic compound composed of a condensed ring of a pyrimidine ring and an imidazole ring, and has the following tautomerism. Exists as the body.

The purine derivative is a compound having a purine skeleton, but in the present invention, a so-called purine base which is usually basic, such as guanine, adenine, and other purine alkaloids, is preferably used.

In the present invention, a plate-like structure is used among the above compounds.

That is, the above compound is generally known as a needle-shaped crystal, but in the present invention, the crystals arranged in such a form at the molecular level are further arranged in a plate shape at the macroscopic level. Use what you have.

For example, guanine components extracted from fish scales are known to form a macroscopic plate-like structure.

By thus mixing the plate-like structure as a toner component, an electrophotographic toner having a metallic luster and an excellent decorative feeling can be obtained.

The plate-like structure used in the present invention preferably has an average particle size of 1 to 40, especially 5 to 30 μm. That is, if the particle size is smaller than the above range, the metallic luster tends to be lost, while if it is larger than the above range, it becomes difficult to produce a particle size suitable for the toner.

Toner composition As the fixing resin medium, resins used in the production of this kind of toner are used, and as particularly preferable ones,
Various mono- or di-ethylenically unsaturated monomers, especially (a) vinyl aromatic monomers, (b) homopolymers or copolymers of acrylic monomers are used.

Examples of the monomer (a) include styrene, vinyltoluene, α-methylstyrene, α-chlorostyrene, vinylxylene and vinylnaphthalene.
Examples of the monomer (b) include acrylic acid, methacrylic acid, ethyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate. , 3-aminopropyl acrylate, 3-N, N-diethylaminopropyl acrylate, acrylamide and the like.

Other monomers used in combination with these monomers (a) or (b), or alone, include butadiene, isoprene, chloroprene, and other maleic anhydride, fumaric acid, crotonic acid, and itacone. Other examples include ethylenically unsaturated carboxylic acids such as acids or esters thereof, vinyl esters such as vinyl acetate, vinyl pyridine, vinyl pyrrolidone, vinyl ethers, acrylonitrile, vinyl chloride, vinylidene chloride and the like.

The molecular weight of these resins is 3,000 to 300,000, especially 5,000.
It is preferably in the range of 0 to 200,000.

In the toner of the present invention, the above-mentioned plate-like structure is compounded in the toner in an amount of 1 to 40% by weight, particularly 5 to 30% by weight. When the blending amount of the crystalline component is less than the above range, it is difficult to sufficiently develop a metallic color tone, and when the blending amount is more than the above range, fixability is lowered, or economically. Tends to be at a disadvantage.

As the colorant, an organic pigment or dye having a particle size of 0.2 μm or less is used from the viewpoint of translucency.

The type of organic pigment is not particularly limited as long as it has the above-mentioned particle size, but for example, a blue-green phthalocyanine pigment, a yellow-red azo pigment, a metal complex salt pigment, a triphenylmethane pigment, a vat dye closely related. A pigment or the like is used. The organic pigment having the above particle size can be obtained by crystallization of the pigment into fine crystals at the final stage of pigment production. As the dye, an oil-soluble dye used for coloring plastics is used.

One of these organic pigments or dyes is used for each fixing resin medium.
It is preferably used in an amount of from 20 to 20% by weight, especially from 2 to 15% by weight.

In the toner of the present invention, a toner compounding agent that does not adversely affect the color of the toner and can be regarded as colorless or white or substantially colorless, such as a charge control agent, an offset preventing agent, a pressure fixing property-imparting agent, and a conductive agent, is well known. It may be blended according to the prescription. As the charge control agent, for the purpose of positive charge control, an organic compound having a basic nitrogen atom, for example, a basic dye, aminopyrine, a pyrimidine compound, a polynuclear polyamino compound, aminosilanes or a filler surface-treated with the same is used. Etc. are used, and as the negative charge control agent, a carboxy group-containing compound such as a metal chelate of alkylsalicylic acid is used. These charge control agents are preferably used in an amount of 1 to 10% by weight per toner. Further, in the method of fixing the toner with a hot roll, an offset preventive agent such as silicone oil, low molecular weight olefin resins and various waxes can be used in an amount of 2 to 15% by weight based on the whole amount. For fixing the toner with a pressure roll, a pressure-fixing imparting agent such as paraffin wax, various animal / vegetable waxes and fatty acid amides may be used in an amount of 5 to 30% by weight based on the whole amount.

Toner and Manufacture of Toner In the present invention, a fixing resin medium in which a plate-like crystal component and a colorant are dispersed is molded into particles having a particle diameter of 5 to 50 μm to obtain a toner.

The toner is manufactured by any means known per se. For example, the above-mentioned coloring agent, plate-like structure and charge control agent are compounded in a fixing resin medium together with other compounding aids if necessary, and this is uniformly and uniformly kneaded, and then granulated to obtain a toner. To do. In molding, it is obtained by cooling the above-mentioned kneaded composition, pulverizing this, and sieving if necessary. Of course, there is no particular problem even if mechanical rapid agitation is performed in order to chamfer the amorphous particles. In this method, it is important to take care so that the plate-shaped structure of the plate-shaped structure itself is not destroyed during kneading and pulverization.

As an alternative method, the fixing resin medium is dissolved in a solvent such as toluene or xylene, and the plate-shaped structure having a certain fine shape and the colorant are dispersed therein, and the resulting undiluted solution is spray-dried and granulated. This makes it possible to obtain toner in the form of spherical particles. This method can be said to be an excellent method in that the plate-like structure is not broken.

Further, by dispersing the plate crystal component in a solvent that dissolves the monomer but does not dissolve the produced polymer, and polymerizing the monomer in the presence of a radical initiator in this system, the toner can also be obtained. Can be obtained. As the monomer, those exemplified above are preferably used.

(Use and Effect) According to the present invention, a metallic color toner for electrophotography, which is excellent in electrophotographic characteristics, decorative effect, durability and the like, is provided.

This toner is used not only for ordinary copying on white paper, but also for the purpose of forming a metallic color image on black paper or colored paper.

(Example) The present invention will be described in the following example.

Example 1. Styrene-acrylic resin (XPA-525 manufactured by Mitsui Toatsu Chemicals, Inc.) 100 parts by weight Low molecular weight polypropylene (Viscor 550-P manufactured by Sanyo Kasei Co., Ltd.) 3 parts by weight Guanine (extracted from fish scales) 15 parts by weight Blue dye ( Orient Oil Blue 2N Orient Chemical Co., Ltd.) 3 parts by weight Charge control agent (Bontron E-84 Orient Chemical Co., Ltd.) 3 parts by weight The above mixture was dissolved and dispersed in 300 parts by weight of toluene using a homomixer, and then spray dried. Thus, spherical blue metallic powder was obtained. Then, it was classified into particles of 5 to 50 μm. Further obtained blue metallic toner 100
0.3% of hydrophobic silica fine particles R-972 (manufactured by Nippon Aerosil Co., Ltd.) was dry-blended with respect to parts by weight.

When 25 g of the obtained metallic blue toner was mixed with 500 g of a ferrite carrier (F141-1530 manufactured by Nippon Iron Powder Co., Ltd.) to prepare a developer, and a copy test was performed using a DC-111C copier (manufactured by Mita Industry Co., Ltd.). , A vivid blue metallic copy was obtained.

Further, when a color paper was used as the transfer paper, a more vivid blue metallic copy was obtained.

Example 2. Polyester resin (Luna Pel 445, manufactured by Arakawa Chemical Co., Ltd.) 100 parts by weight Low molecular weight polyethylene wax (Sun Wax 161-P, manufactured by Sanyo Kasei Co., Ltd.) 2 parts by weight Green dye (Orient Oil Green 530, manufactured by Orient Chemical Co., Ltd.) 3 parts by weight Charge control agent (Bontron E-84, manufactured by Orient Chemical Co., Ltd.) 2 parts by weight The above mixture is mixed with a ribbon blender and thoroughly kneaded with a Banbury mixer. The guanine crystals were orientated well. Next, the mixture was finely pulverized with a jet mill fine pulverizer, 5 to 50 µ of green metallic particles were collected with a classifier, and hydrophobic silica fine particles R-972 were dry blended with 100% by weight of green metallic to 0.3%.

25 g of the obtained metallic green toner and 500 g of a ferrite carrier (F141-1530) are mixed to prepare a developer,
When a copy test was performed using a DC-111C copying machine, a bright green metallic copy was obtained. When a color paper was used as the transfer paper, a brighter green metallic copy was obtained.

Example 3 8 g of polyacrylic acid was dissolved in 800 ml of ethanol, and 80 g of styrene, 20 g of n-butyl methacrylate and guanine were dissolved in this solution.
10g, Dye (Aizen SOT Red 1, Hodogaya Chemical Co., Ltd.)
3 g and 1 g of azobisisobutyronitrile were added, and the reaction was carried out at 80 ° C while stirring at 150 rpm in a separable flask under a nitrogen stream at the time when the polymerization rate reached 80%. 1 g of ethyl methacrylate was added, and the polymerization was completed over 15 hours. The polymer is separated by sedimentation, washed 3 times with ethanol, then dried to give 96g of 5-50μ.
m metallic red toner was obtained. Further, 0.1 part by weight of hydrophobic silica fine particles R-972 was dry-blended with 100 parts by weight of the obtained metallic red toner.

25 g of the thus obtained metallic red toner was mixed with 500 g of a ferrite carrier (F141-1530) to prepare a developer, and a copying test was conducted with a DC-111C copying machine, and a bright metallic red copy was obtained. Further, when a color paper was used as the transfer paper, a more vivid metallic red copy was obtained.

Claims (2)

[Claims] 1. An electron having a particle size of 5 to 50 μm, which is obtained by mixing a fixing resin, a colorant, and a compounding agent for a toner with a plate-like structure of purine or a derivative thereof having an average particle size of 1 to 40 μm. Photographic metallic toner. 2. The metallic toner according to claim 1, wherein the plate-shaped structure is contained in an amount of 1 to 40% by weight per toner.