JPH11143129A - Dyed toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a yellow dyed toner having a narrow particle size distribution, excellent in light resistance and sublimability even in the case of a small particle diameter and giving high density by using a colorant contg. at least one compd. of a methine dye. SOLUTION: Thermoplastic resin-base powdery particles are dyed with a yellow colorant, in particular a colorant contg. at least one compd. of a methine dye to obtain the objective dyed toner. Thermoplastic resin particles used may be particles obtd. by pulverization, suspension polymn. or emulsion polymn.- aggregation. A method such as seed polymn. or dispersion polymn. is preferably adopted so as to obtain particles having a narrow particle size distribution. The yellow dye is, e.g. Disperse Yellow 31, 49, 61, 73, 82, 87, 88, 89, 90, 91, 93, 99, 109, 116, 118 or 201 or Solvent Yellow 32, 79 or 93.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dyeing toner used in an image recording apparatus such as a copying machine and a printer, and more particularly to a dyeing toner in which a colorant is dyed on powder particles.

[0002]

2. Description of the Related Art Conventionally, an image recording method used in a printing apparatus such as a copying machine, a printer, and a facsimile is roughly classified into an impact recording method and a non-impact recording method. Also,
Non-impact recording methods include recording methods such as a thermal transfer recording method, a thermal recording method, an electrophotographic recording method, an electrostatic recording method, and an ink jet recording method. Of these, in the electrophotographic recording method and the electrostatic recording method, In order to develop an image on a recording medium such as paper, toner is used.

Here, the general principle of the electrophotographic recording method using toner will be briefly described. This method
First, the surface of the photoconductor made of a photoconductive substance is charged to a uniform potential. Then, the surface of the photoreceptor is
Exposure is performed along an image to be output to form an electric latent image. The latent image formed there is developed by the developing unit.
The image is developed by the toner stored in the developing device, and a visible image is formed. Then, the visible image formed on the surface of the photoconductor is transferred to a recording medium such as paper, and then fixed on the recording medium by heat and pressure of a fixing device.

[0004] The toner used in the electrophotographic recording method described above is fine particles mainly containing a binder resin component and a coloring component, and contains only a toner developed into a latent image on a photoreceptor as a component. It is roughly classified into a one-component developer and a two-component developer in which a toner is mixed with glass beads, ferrite, iron powder particles and the like.

Conventionally, the toner has been manufactured by a pulverization method in which a binder resin and a colorant are melt-kneaded and then pulverized to a predetermined size by a pulverizer. But,
Since a large amount of fine powder is contained in the particles pulverized by this method, there is a problem that extra fine powder must be removed by a classification process for uniforming the particle size distribution.

Further, since the removed fine powder is recovered as unnecessary particles, there is a problem that the yield of particles obtained as a product is low with respect to the charged amount.

In order to solve the above-mentioned problems, methods for producing a toner by a polymerization method, for example, a suspension polymerization method, an emulsion polymerization aggregation method and a dispersion polymerization dyeing method have been proposed.

In the suspension polymerization method, a monomer and a colorant are mixed in a poor solvent in which the monomer is insoluble, and the monomer is dispersed with a stirring blade. Is to manufacture.

In this method, although colored particles can be produced by one polymerization operation, the particle size of the colored particles is controlled by the particle size of the monomer dispersed in the solvent.
In order to produce the following small particle size, it was necessary to carry out polymerization while controlling heating by stirring. However, it was very difficult to reduce the particle size to 7 μm or less because the strength of stirring was limited.

[0010] The particles produced by suspension polymerization contain a large amount of fine powder, though not as much as in the pulverization method. Therefore, a classification step is required after drying the colored particles.

In the emulsion polymerization coagulation method, a monomer and a polymerization initiator soluble in the poor solvent are mixed in a poor solvent in which the monomer is not soluble, and polymerization is started at a place different from the dispersed particles of the monomer. 1μ
A large number of particles of about m are generated. After that, by operating the solvent in which the particles and the colorant are dispersed,
Small particles of about 1 μm are aggregated to produce small particle aggregates of 5 μm or more.

However, the particle size distribution of the particles produced by this method is substantially the same as the particle size distribution of the particles produced by the pulverization method, because the particle size distribution is affected by stirring when the particles are aggregated.

In the dispersion polymerization dyeing method, the dispersion polymerization particles and the polymerization initiator are simultaneously dissolved in a good solvent in which the monomer is soluble,
As the polymerization proceeds, a polymer component that is no longer soluble in the solvent is precipitated to form particles.

The particles produced by this method have a narrow particle size distribution and a uniform particle size, but it is difficult to mix a colorant during polymerization and color simultaneously with the polymerization. Was dispersed again in a solvent to dye the polymer particles with the colorant.

[0015]

However, when the toner produced by the dispersion polymerization dyeing method (hereinafter referred to as a dyeing toner) is used for a color print as a recording material, the dyeing toner of four colors is used. Yellow, magenta, cyan, and black are needed to represent all colors. However, when expressing all colors with four colors,
Unless the reproduction range of each color is wide, all colors cannot be faithfully reproduced. In order to widen the color reproduction range, the color of the dye is limited.

The dyeing on the polymer particles can be achieved by transferring the dye into the polymer particles. However, when the solution for dyeing has a sufficient concentration, the dyeing after dyeing is completed. In most cases, the dye is slightly transferred to the colored particles. Therefore, there is a problem that the dyeing concentration after dyeing is completed is low.

Further, there is a problem that some of the dyes are inferior in light fastness, and are also inferior in sublimability in examining color transfer by laminating resin films.

The present invention has been made to solve the above problems, and provides a yellow dyeing toner having a narrow particle size distribution, excellent light resistance and sublimation even with a small particle diameter, and high density. It is intended to be.

[0019]

In order to achieve this object, a dyeing toner according to the first aspect of the present invention is a dyeing toner, wherein a yellow colorant is dyed on powder particles mainly composed of a thermoplastic resin. In particular, the colorant is characterized in that the colorant contains at least one methine dye compound.

According to the dyeing toner according to the first aspect of the present invention having the above-described structure, a colorant is dyed on powder particles containing a thermoplastic resin as a main component, and the colorant is a methine-based colorant. Because it contains a dye compound, the particle size distribution is narrow,
Excellent light fastness and sublimability, high yellowish density.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the dyed toner of the present invention will be described.

The thermoplastic resin particles used in the present invention are:
Particles obtained by a pulverization method, a suspension polymerization method, or an emulsion polymerization aggregation method can be used. In order to obtain particles having a narrow particle size distribution, it is desirable to use a method such as seed polymerization or dispersion polymerization. Dispersion polymerization is also called precipitation polymerization, in which a polymerization initiator and a polymer dispersant are simultaneously dissolved in an organic solvent in which a monomer is dissolved, and polymerization is started while maintaining a constant temperature. Further, it is also possible to add a surfactant or a crosslinking agent as needed.

Hereinafter, materials used in the dispersion polymerization dyeing method will be described with reference to examples.

(Organic solvent) Examples of the organic solvent for dissolving the polymerizable monomer used in the present embodiment include methanol, ethanol, isopropyl alcohol, n-butanol, s-butanol, t-butanol, n-amyl alcohol, s-amyl alcohol, t-amyl alcohol, isoamyl alcohol, isobutyl alcohol, isopropyl alcohol, 2-ethylbutanol, 2-ethylhexanol, 2-octanol, n-octanol, n-decanol, cyclohexanol, n-hexanol, 2- Heptanol, 3-heptanol, 3-pentanol, methylcyclohexanol, 2-methyl-
Alcohols such as 2-butanol, 3-methyl-2-butanol, 3-methyl-1-butyn-3-ol, 4-methyl-2-pentanol, and 3-methyl-1-pentyn-3-ol; Seeds or a mixture of two or more.

Further, organic solvents used in combination with these alcohols include, for example, hydrocarbon solvents such as hexane, toluene, cyclohexane, benzene, and xylene;
Ethyl benzyl ether, dibutyl ether, dipropyl ether, dibenzyl ether, dimethyl ether,
Ethers such as tetrahydrofuran, vinyl methyl ether and vinyl ethyl ether, acetaldehyde, acetone, acetophenone, diisobutyl ketone, diisopropyl ketone, ketones such as cyclohexanone, ethyl formate, ethyl acetate, methyl acetate, ethyl stearate,
Esters such as methyl salicylate and water. These solvents are used to adjust the SP value of the alcohol.

The weight ratio of the organic solvent to the monomer is 1
00 to 5 to 80 is appropriate.

(Monomer) As the monomer having a polymerizable functional group, a compound containing a vinyl group can be used. For example, styrene, methylstyrene, ethylstyrene, 2,4-dimethylstyrene, pn- Butylstyrene, styrene monomers such as pt-butylstyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate,
Cyclohexyl acrylate, methyl methacrylate,
Ethyl methacrylate, n-butyl methacrylate, 2
-Methyl fatty acid monocarboxylic acid esters such as ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, and n-butyl vinyl ether; acrylonitrile, methacrylonitrile, vinyl acetate, and vinyl chloride , Ethylene, propylene, chloroprene, and other vinyl compounds alone or in a mixture of two or more.

(Polymerization Initiator) The polymerization initiator for polymerizing the monomer is suitably added in an amount of 0.001 to 10% by weight, for example, lauryl peroxide, benzoyl peroxide, azobisisobutyronitrile. And so on.

(Dispersant) A dispersant is mixed in an organic solvent from an early stage of polymerization for the purpose of preventing aggregation of the formed polymer particles at the same time as polymerization starts to form particles. The amount of the mixture is the mixture 1
0.1 to 30 parts by weight is suitable for 00 parts by weight. Examples of the dispersant include polystyrene, polyvinyl acetate, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polyethylene, polypropylene, polylauryl methacrylate, polyoxyethylene, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, and polyacrylamide. , Polyvinyl pyrrolidone, polyethylene imine, polyvinyl methyl ether,
Poly-4-vinylpyridine, polystyrenesulfonic acid and the like.

After appropriately mixing a monomer and a dispersant in the organic solvent and purging with nitrogen, a polymerization initiator is added, and the temperature of the dispersion solution is raised to start polymerization. 40-50 ° C
When the temperature reached, the solution began to become cloudy, and it was confirmed that a polymer component that could not be dissolved in the solvent began to precipitate.

While confirming the particle size distribution and the conversion,
The temperature is kept constant and stirring is continued until the polymerization is completed for 24 hours. After completion of the polymerization, the temperature of the polymer particle dispersion maintained at a constant temperature is lowered to room temperature to complete a series of polymerization operations. The polymer particle dispersion solution is centrifuged,
The particles and the solution are separated and dispersed again in a solvent in order to wash away unreacted monomers and dispersants attached to the particle surfaces. The washing operation is repeated, and the thermoplastic fine particles are dried when it is recognized that the residue on the particle surface has disappeared.

The thermoplastic fine particles thus synthesized are dispersed again in a solvent for dyeing. The solvent used for dyeing is a condition that does not dissolve the thermoplastic fine particles. For example, methanol, ethanol, isopropyl alcohol, n-butanol, s-butanol, t-
Butanol, n-amyl alcohol, s-amyl alcohol, t-amyl alcohol, isoamyl alcohol,
Isobutyl alcohol, isopropyl alcohol, 2-
Ethyl butanol, 2-ethylhexanol, 2-octanol, n-octanol, n-decanol, cyclohexanol, n-hexanol, 2-heptanol,
3-heptanol, 3-pentanol, methylcyclohexanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 3-methyl-1-butyn-3-ol, 4-methyl-2-pentanol, 3-methyl-1-
Alcohols such as pentyn-3-ol or water can be used alone or in combination of two or more.

It is preferable that 1 to 50 parts by weight of the thermoplastic fine particles and 1 to 30 parts by weight of the coloring agent are mixed per 100 parts by weight of the organic solvent.

The dye used as a colorant in the present invention is, for example, Disperse Yellow 31, 49, 6
1, 73, 82, 87, 88, 89, 90, 91, 9
3, 99, 109, 116, 118, 201, Solvent Yellow 32, 79, 93 and the like.

The solution in which the thermoplastic fine particles and the colorant are dispersed is heated to 30 to 40 ° C. and kept at a constant temperature for 30 minutes to 30 minutes.
Dye while stirring for 2 hours. After completion of the dyeing, the temperature is lowered to room temperature, and the colored particles and the solvent are separated by a centrifuge. Further, in order to wash away the residual colorant attached to the surface of the colored particles, washing and separation with a solvent are repeated. The lump of the colored particles separated from the solvent is dried with a stirring drier kept at 30 to 40 ° C. to remove dyed thermoplastic fine particles in order to remove the absorbed solvent.

The dyed thermoplastic fine particles have durability,
In order to satisfy the fixability, fine particles and a release agent can be driven in using a machine such as a hybridizer or mechanofusion.

Hereinafter, examples of the dyed toner will be described.

(Production Example 1 of Polymerized Particles) 450 parts by weight of methanol and 150 parts by weight of isopropyl alcohol were mixed in a four-necked flask equipped with a stirring blade, a cooler, a thermometer, and a gas inlet tube. -3
0) Dissolve 20 parts by weight. To this, 160 parts by weight of styrene, 40 parts by weight of n-butyl acrylate and 8 parts by weight of 2,2-azobisisobutyronitrile were added and stirred to obtain a transparent solution. While stirring, the inside of the flask was replaced with nitrogen gas, the temperature was increased to 60 ° C., and polymerization was started at a stirring blade rotation speed of 100 rpm. Ten minutes after heating, the solution began to become cloudy, and polymerization was performed for 10 hours in this state.

After 7 hours from the start of the polymerization, 200 parts by weight of a 1: 1 mixed solvent of water and methanol was added dropwise over 1 hour, and the temperature was returned to room temperature to complete the polymerization. This slurry was subjected to a first centrifugation using a 3 μm filter, further redispersed in a mixed solvent of methanol and water, and then subjected to a second centrifugation using a 3 μm filter, and dried for one day and night. The resulting thermoplastic fine particles had a volume average particle diameter Dv of 7.2 μm, and the ratio (dispersion degree) of volume average particle diameter Dv / number average particle diameter Dp was 1.07.

(Production Example 2 of Polymerized Particles) Particles obtained by performing the same procedure and the same operation as in Production Example 1 of polymerized particle except that the monomer composition was changed to 160 parts by weight of styrene and 40 parts by weight of ethyl acrylate, , Dv = 7.11 μm, D
Thermoplastic fine particles having v / Dp = 1.12.

(Example 1) 100 parts by weight of methanol was poured into a 300 ml beaker. I. DISPERSE
Add 3 parts by weight of YELLOW 82 and stir with 4
The polymer is dissolved in a water bath at 0 ° C., and 30 parts by weight of the thermoplastic dry fine particles obtained in Production Example 1 of the polymer particles are dispersed. The mixture was stirred for 1 hour under reflux with heating to perform dyeing. The first centrifugation was performed with a 3 μm filter, and the mixture was re-dispersed in 100 parts by weight of a 1: 1 solvent of methanol and water, followed by a second centrifugation. The particles were dried all day and night to obtain yellow colored particles.

3 parts by weight of hydrophobic silica (RA200H) was mixed with 100 parts by weight of the particles, and the mixture was stirred with a mixer to obtain a positively charged dyed toner. The charge amount is iron powder 1
00 parts by weight, 4 parts by weight of the dyed toner were mixed, and measured with a blow-off charge amount measuring device, the result was +21 μC.
/ G.

The dyed toner was filled into a developing process for controlling the flying of the toner by controlling the voltage applied to the electrodes arranged in each opening and controlling the voltage applied to the electrodes. A yellow image having a sufficient reflection density of 1.14 without any offset was obtained in the image forming apparatus.

The reflection density was measured using a reflection densitometer RD manufactured by Macbeth.
It was measured at -917 and passed through a blue filter. In order to obtain a yellow image having a high density and no unevenness, the reflection density is desirably 1.1 or more.

Example 2 100 parts by weight of methanol was poured into a 300 ml beaker. I. DISPERSE
3 parts by weight of YELLOW 201 is added and dissolved in a water bath at 40 ° C. with stirring, and 30 parts by weight of the thermoplastic dry fine particles obtained in Production Example 1 of polymer particles are dispersed. The mixture was stirred for 1 hour under reflux with heating to perform dyeing. The first centrifugation was performed with a 3 μm filter, and the mixture was re-dispersed in 100 parts by weight of a 1: 1 solvent of methanol and water, followed by a second centrifugation. The particles were dried all day and night to obtain yellow colored particles.

3 parts by weight of hydrophobic silica (RA200H) was mixed with 100 parts by weight of the particles, and the mixture was stirred with a mixer to obtain a positively charged dyed toner. The charge amount is iron powder 1
00 parts by weight, 4 parts by weight of the dyed toner were mixed, and measured with a blow-off charge amount measuring device, the result was +28 μC
/ G.

The dyed toner has an opening, and the voltage applied to the electrodes arranged in each opening is controlled to control the voltage applied to the developing process for controlling the flying of the toner. A yellow image having a sufficient reflection density of 1.22 without offset was obtained in the image forming apparatus.

(Example 3) In the same manner as in (Example 1), dyeing was carried out using the particles produced in Polymer Particle Production Example 2.

The temperature was raised to 40 ° C., and the mixture was heated under reflux for 1 hour 3 hours.
Dyeing was carried out with stirring for 0 minutes, and washing was repeated, followed by drying all day and night to obtain yellow colored particles.

With respect to 100 parts by weight of the dyed particles,
3 parts by weight of hydrophobic silica (RA200H) were mixed and stirred with a mixer to obtain a positively charged dyed toner. The charge amount was measured by using a blow-off charge amount measuring device by mixing 4 parts by weight of the dyeing toner with respect to 100 parts by weight of iron powder.
+24 μC / g.

The dyed toner is provided with an opening, and the voltage applied to the electrodes arranged in each opening is controlled so that the toner is charged into a developing process for controlling the flying of the toner and printed. A yellow image having a sufficient reflection density of 1.44 without offset was obtained in the image forming apparatus.

(Comparative Example 1) The same solvent as in (Example 1),
Dyed with the azo dye SOLVENT YELLOW 3 at the charged amount,
The polymer particles were produced using the particles of Production Example 1. The results are shown in Table 1 below.

[0053]

[Table 1]

[0054]

As is apparent from the above description, according to the dyed toner of the first aspect of the present invention, the yellow colorant is dyed on the powder particles mainly composed of the thermoplastic resin. Since the coloring agent contains at least one methine dye compound, the dyeing toner has a narrow particle size distribution, is excellent in light resistance and sublimation even at a small particle diameter, and has a high yellow density. Can be offered.

Claims (1)

[Claims] 1. A dyed toner in which a yellow colorant is dyed on powder particles mainly composed of a thermoplastic resin, wherein the colorant contains at least one methine dye compound. A dyed toner characterized in that: