JPS62100770A - Golden color toner for electrophotography - Google Patents

Abstract

PURPOSE:To obtain a golden color toner having excellent electrophotographic characteristics and ornamental effect by incorporating a pigment coated with a thin layer consisting of titanium dioxide and yellow iron oxide on a flaky inorg. crystal substrate as a coloring agent into the toner. CONSTITUTION:This toner for electrophotography formed by incorporating a resin for fixing, coloring agent and compounding agent for the toner is the golden color toner for electrophotography of which the coloring agent is the pigment coated with the thin layer consisting of the titanium dioxide and yellow iron oxide on the flaky inorg. crystal substrate. Mica is most preferable in terms of an aspect ratio as the flaky inorg. crystal substrate of the pigment and any material which is the flaky inorg. crystal is used. The amts. of the titanium dioxide and yellow iron oxide to be deposited on the flaky substrate are determined by the degree of metallic gloss and coloration to the golden color and are preferably in the range of 30-45wt% titanium oxide and 3-10wt% yellow iron oxide per the pigment.

Description

[Detailed description of the invention] (Field of industry E) The present invention relates to a gold toner for use in electrophotography.

(Prior art) In electrophotography D, a charge image formed on the surface of a photoreceptor is developed with a toner having electrodetection properties and fixing properties, and the developed toner image is transferred to a transfer paper. First, the toner is fixed to form an image. Various black to color toners are known as electrophotographic toners used for this purpose, but a gold toner is not yet known.

(Problems to be Solved by the Invention) In fields where prescription and decorative properties are required, electrophotographic copies and printed matter of golden images are sometimes required.
Conventional toners could not be applied to such uses.

When producing golden toner, the most common idea is to incorporate golden metal powder such as Cu-Zn alloy into the toner, but such metal powder is extremely difficult to handle. There is an extremely high risk of causing a dust explosion when turning into toner.

Therefore, an object of the present invention is to provide a golden toner that can be applied to electrophotography.

Another object of the present invention is to provide an electrophotographic toner that can be easily manufactured without the above-mentioned risks and has an excellent golden decorative feel.

Still another object of the present invention is to provide a golden toner that also has excellent electrophotographic properties.

(Means for Solving the Problems) The inventor of the present invention has discovered that when a toner contains as a coloring agent a pigment in which a thin layer of titanium dioxide and yellow iron oxide is coated on a flaky inorganic crystal matrix, It has been found that the above-mentioned problems can be solved and a golden toner with excellent electrophotographic properties and decorative effects can be provided.

(Function) The coloring agent used in the present invention is characterized in that it consists of a scaly pigment in which a flaky inorganic crystal matrix is coated with a thin layer of titanium dioxide and yellow iron oxide. When a toner made by dispersing this pigment in a fixing resin medium is fixed on paper, a layered structure in which flake-like pigments are arranged substantially parallel to the paper surface is formed by the fixing pressure.

The light incident on the fixed image with such a layered structure is regularly and multiple-reflected within the 9 multi-haired films of titanium dioxide and yellow iron oxide formed on the flaky substrate E, resulting in a metallic luster (pearly luster). is emphasized, and the yellow iron oxide in the thin film gives it a golden color. That is, the yellow iron oxide in the thin film gives it a golden color, and the titanium dioxide has a large refractive index, giving it a metallic luster.

Thus, it will be apparent that the present invention can impart superior golden decoration to fixed images of toner.

In addition, the pigment used in the present invention itself is composed of a chemically stable inorganic oxide, and as a result, problems such as powder explosion during toner production that occur when metal powder is used are eliminated. However, the toner has the advantage that the coloring agent is extremely stable against light, heat, corona discharge, ozone, etc., and the fastness of one image is also extremely excellent.

Further, since this pigment is electrically insulating and insensitive to humidity and the like, it also has the advantage of not impairing the electrophotographic properties of the toner at all.

(Description of Preferred Embodiments of the Invention) As the flaky inorganic crystal substrate for the flaky pigment pigment, mica is the best in terms of aspect ratio, but any flaky inorganic crystal substrate may be used, such as Barium sulfate, layered silicates, layered aluminosilicate IF, etc. can be used. Generally speaking, it is desirable that the substrate's 7 spectral ratio (thickness to length ratio) be in the range of about 1:10 to 1:50.

The amount of titanium dioxide and yellow iron oxide to be deposited on this flaky substrate is determined by the degree of methacrylic gloss and golden coloring, but the amount of titanium dioxide per pigment is between 3 and 4.5 billion %, especially between 3.5 and 4.5 billion. It is preferable that the content is in the range of 43% by weight, and -.
The coating of a thin film of titanium dioxide and yellow iron oxide, preferably in the range of 5 to 8%, can be formed by a method known per se, for example, in a slurry containing a flaky substrate, an IT-soluble titanium compound and It can be produced by gradually hydrolyzing a solution of a soluble iron compound and gradually depositing titanium dioxide and yellow iron oxide into a B flaky substrate.

The scaly pigment used in the present invention preferably has an average particle size of 1 to 404 m, particularly 5 to 3 olm, that is, the particle size is smaller than the above range. and,
There is a tendency for metallic luster to be lost, and if the particle size is larger than the range described in (E), it becomes difficult to produce particles with a particle size suitable for toner.

As the resin medium for fixing, resins used in the production of this type of toner are used, and particularly preferred are resins 1.
Various heptano- or diethylenically unsaturated intermediates, especially (a) vinyl aromatic monomers.

(b) Acrylic medium (true identity) Homopolymers and copolymers of these are used.

Examples of the monomer (a) above include styrene, vinyltoluene, α-methylstyrene, α-chlorostyrene, vinylxylene, and vinylnaphthalene,
Further, the ii-mer of (b) includes acrylic acid, methacrylic acid, ethyl acrylate, methyl methacrylate, butyl 7-acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 3-hydroxypropyl acrylate, Examples include 2-hydroxyethyl methacrylate, 3-aminopropyl acrylate, 3-N,N-diethylaminopropyl acrylate, and acrylamide.

Other monomers used in combination with these monomers (a) or (b) or alone include butadiene, isoprene, chloroprene, maleic anhydride, fumaric acid, crotonic acid, etc. , other ethylenically unsaturated carboxylic acids or their esters such as itaconic acid, vinyl esters such as vinyl acetate, vinylpyridine, vinylpyrrolidone, vinyl ethers, acrylonitrile, vinyl chloride, vinylidene Ia, etc. .

The molecular weight of these resins is 3. Goo ~ 300,00
0° is preferably in the range of 5,000 to 200,000.

In the toner of the present invention, the above-mentioned yellow flaky pigment is present in an amount of 1 to 40% by weight, particularly 5 to 30% by weight.
In other words, when the amount of the pigment blended is less than the range specified in L.

It becomes difficult to sufficiently express a metallic golden color, and if the amount exceeds the above range, fixing properties may be low,
Alternatively, it tends to be economically disadvantageous.

In the toner of the present invention, the scale-like pigment mentioned above can be used alone or in combination with other golden pigments, dyes, or transparent fillers, and thereby the color tone etc. can be adjusted. It's easy.

The toner of the present invention contains toner additives that can be considered to be golden, white, or substantially colorless and do not adversely affect the color of the toner, such as a charge control agent, an anti-offset agent, a pressure fixability imparting agent, and a conductive agent. They can be formulated according to well-known formulations.
=il! As a charge control agent, for the purpose of positive charge control,
Organic compounds having a basic nitrogen atom, such as basic dyes, aminopyrine, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, or fillers whose surfaces have been treated with these are used, and as negative charge control agents.

Carboxy group-containing compounds, such as alkyl salicylic acid chelates, are used. These charge control agents are preferably used in an amount of 1 to 10% by weight per toner, and
In the method of fixing the toner with a hot roll, an anti-offset agent such as silicone oil, low molecular weight olefin resins, various waxes, etc. can be used in an amount of 2 to 15 tonne percent based on the total amount.

Further, in applications where the toner is fixed with a pressure roll, a pressure fixing agent such as paraffin wax, various animal/vegetable waxes, fatty acid amide, etc. may be used in an amount of 5 to 3011% based on the total amount.

Toner and toner production In the present invention, a scaly pigment dispersed in a fixing resin medium is formed into particles each having a particle size of 5 to 50 μm,
Use toner.

The production of toner is carried out in this one step, as is known per se.
For example, the above-mentioned colorant and anti-charge W agent are blended into the fixing resin medium along with other blending aids if necessary, and the mixture is uniformly kneaded and then granulated to form a toner. For molding, after cooling the above-mentioned kneaded composition,
Crush this.

Obtained by sieving if necessary. Of course, there is no particular problem in performing rapid mechanical stirring in order to round off irregularly shaped particles.In this method, the particle structure of the flake-shaped pigment particles I- itself is not destroyed during kneading and crushing. It is important to pay attention to this.

Alternatively, the fixing resin medium is dissolved in a solvent such as toluene or xylene, and the scaly pigment is dispersed therein.
A toner in the form of one spherical particle can be obtained by spray-drying and granulating the obtained stock solution, and this method can be said to be an excellent method in that it does not cause destruction of the scaly pigment.

Furthermore, the scaly pigment is dispersed in a solvent that dissolves the monomer but does not dissolve the resulting polymer.

A toner can also be obtained by polymerizing monomers in this system in the presence of a radical initiator. As monomers, those exemplified above are preferably used.

(Applications and Effects) According to the present invention, an electrophotographic golden toner excellent in electrophotographic properties, decorative effects, and durability is provided.

This toner is used for copying on ordinary white paper, and is also advantageously used for forming golden images on black paper or young colored paper.

(Example) The invention is illustrated in the following examples.

Example 1 After dissolving and dispersing the mixture in 300 beads of Toluene using a homomixer, a bead-shaped powder was obtained by spray drying. Thereafter, it was classified into particles of 5 to 50 liters.

Furthermore, hydrophobic silica fine particles 7-R-972 (manufactured by Nippon Aerosil Co., Ltd.) 0.
Dry blended 3X.

25g of the obtained golden toner and ferrite carrier (F1
41-1530 (manufactured by Nippon Iron Powder Co., Ltd.) 500g to create a developer,
When I conducted a copy test, a bright golden copy was obtained.

Further, when colored paper was used as the transfer paper, even more vivid golden copies were obtained.

Example 2゜The E2 mixture was mixed with a ribbon blender, thoroughly kneaded with a Banbury mixer, and then 10 parts by weight of pearl pigment (Barl Glaze MDY manufactured by Nihon Kokenko! Co., Ltd.) was added and dispersed in a short period of time. The pearl pigment crystals were finely pulverized using a zero-order jet mill pulverizer in which the pearl pigment crystals were well oriented using a calender roll, and 5 to 50 μL of particles were collected using a classifier, and the hydrophobic silica fine particles R-972 were added to 100 parts by weight of golden toner. against 0.
3z was dry blended.

25g of the obtained golden toner and ferrite carrier (F1
41-1530) 500 g of Ik was mixed to prepare a developer, and a copying test was performed using a 1G-1110 copying machine, and a bright golden copy was obtained. Further, when color paper was used as the transfer paper, a more vivid golden color was obtained.

Example 3 8 g of polyacrylic acid was dissolved in 800 mJl of ethanol, and 80 g of styrene and methano IJ Arm -n-
Added 20 g of butyl, 1105 g of pearl pigment (lamellar mica powder coated with titanium dioxide and iron oxide) and tg of azobisisobutyronitrile, and stirred in a 1 U separable flask with a nitrogen stream 'Fl 50 r, p, m. The reaction was carried out at 80° C., and when the polymerization rate reached 80%, 1 g of 2-7 phosphooxyethyl methacrylate was added, and the polymerization was completed over 15 hours. The mixture was separated by sedimentation, washed three times with ethanol, and then dried to produce 96 g of 5-501 L.
A golden toner of m was obtained. Further obtained golden toner 10
Hydrophobic silica fine particles 7-R-8720- for 0 parts by weight
1 ffiffi part was dry blended.

A developer was prepared by mixing 25 g of the golden toner thus obtained and 500 g of ferrite carrier (F141-1530), and a copying test was performed using a DC Knee 111C copying machine, resulting in a bright golden copy. Also,
When colored paper was used as the transfer paper, more vivid golden copies were obtained.

Claims (3)

[Claims] (1) In an electrophotographic toner comprising a fixing resin, a colorant, and a toner compound, the colorant is a pigment in which a thin layer of titanium dioxide and yellow iron oxide is coated on a flaky inorganic crystal substrate. A golden toner for electrophotography characterized by: (2) The golden toner according to claim 1, wherein titanium dioxide is present in the pigment in an amount of 30 to 45% by weight and yellow iron oxide is present in an amount of 3 to 10% by weight. (3) The golden toner according to claim 1, wherein the pigment is present in the toner in an amount of 1 to 40% by weight.