JPS6057858A - Toner for electrophotography - Google Patents

Abstract

PURPOSE:To absorb thoroughly light energy in the near IR region where the emission intensity of a xenon flash lamp is high and to decrease the change in the color tone colored by a coloring material by incorporating a benzene dithiol metallic omplex into a toner for electrophotography which performs fixing to recording paper by photofixing. CONSTITUTION:A binder resin, a coloring agent, the benzene dithiol metallic complex expressed by the formula (in which x denotes hydrogen, halogen group or alkyl group, n denotes 1-4 integer, M denotes nickel, cobalt, palladium or platinum atom and A denotes a quaternary ammonium group) and charge control agent are kneaded, melted and uniformly dispersed by a kneader for pressurization, roll mill, extruder or the like. The cooled toner mass after kneading is pulverized by, for example, a grinder, jet mill or the like and is classified by a pneumatic classifier or the like. The practicable color toner of which the light absorptivity is exceptionally large in the near IR region and is extremely small in the visible region and has less change in hue and saturation and the black toner having excellent fixability are thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (al) Technical Field of the Invention The present invention relates to toner used to visualize electrostatic latent images in electrophotography, and in particular to toner that is fixed to recording paper by optical fixation. Regarding photographic toner.

(bl Background of the Technology) Electrophotography, which is used in copiers, laser printers, etc., generally applies a uniform electrostatic charge to a photoconductive insulating layer and irradiates a light image onto the insulating layer. By doing so, the electrostatic charge 6:f is partially removed to form an electrostatic latent image, and a fine powder called toner is attached to the remaining part of the electrostatic charge to visualize the latent image to create a toner image. After forming (referred to as development) and transferring the toner image onto recording paper, the toner is fixed to the recording paper (referred to as fixing) to obtain printed matter.

The toner is a natural or synthetic polymer W? A fine powder obtained by dispersing a colorant, a charge control agent, etc. in a binder resin and pulverizing it to a size of about 1 to 30 μm.
I
I! j i7L! ! - Image I3 is formed only with that toner.

As the fixing method, heat pressure fixing, pressure fixing, solvent fixing, optical fixing, etc. are known. Among these fixing methods, flash fixing, which is a typical photofixing method, is a method of fixing a 1-ner image on recording paper by irradiating flash light from a discharge tube such as a xenon flash lamp. (1) Non-contact fixing does not degrade image resolution during development.

■ There is no waiting time after the power is turned on, and a quick start is possible.

■ Even if recording paper gets jammed in the fuser due to system failure, no fire will occur.

■ It is possible to fix images regardless of the material or thickness of the recording paper, such as glued paper, preprinted paper, or paper of different thickness.

It is the most desirable fixing method because it has major characteristics such as 7. Since there is only one color toner available, and office automation (OA) equipment is becoming more and more colored, early commercialization of color toner is desired.

tc) Prior art and problems In FIG.
The process of fixing to the recording paper 2 is as follows.

As mentioned above, when the toner image is transferred to the recording paper 2, the image is formed by adhering the toner image as a powder to the paper sheet 2, as shown in the figure (al). If the image is expressed as ``, the image will be destroyed.For example, when the flash 3 of a discharge tube such as a xenon Franche lamp is irradiated, the toner 1 absorbs the energy of the flash 3 and converts it into thermal energy. As the temperature rises, it melts and adheres to the recording paper 2. After the 3 strong flashes, the temperature drops and solidifies, forming a slightly fixed image 4 as shown in Figure tb+, completing the fixing.
The fixed image 4 stuck to the recording paper 2G can be touched, for example, with a finger (km-)
But it will look like this without collapsing.

What is important here is that toner 1 melts and records h*i+t
It is to closely adhere to 2, and for that purpose, 1~zum-
1 is dissipated into the outside world and is not used to raise the temperature (,4).
need to be absorbed from

Although the spectral distribution of the xenon Franche lamp, which is commonly used as a discharge tube for flash fixing, covers a wide range from ultraviolet to infrared, as shown in Figure 2, the emission intensity is particularly strong. It is only in the near-infrared region from 800 to 11,000 nm, and other regions including the visible region from 7,100 to 800 nm are relatively weak.

However, the polymeric substance that is the binder resin that forms the main body of the toner 1 may be, for example, polystyrene, a copolymer of styrene and acrylate or mekkrylate-1, polyester resin, epoxy resin, polyamide resin, etc.
In both cases, the absorption of light energy in the visible and near-infrared regions is extremely small.Furthermore, colorants outside the range of use have absorption in the visible region but small absorption in the near-infrared region; Since the absorption in the outer region is also small, the color toner made from these combinations is 1j44 JI of Flash 3.
J hardly melts. For this reason, until now, there has been no practical color toner for flash fixing, but as office automation equipment is becoming increasingly color-based, its early commercialization is desired.

On the other hand, in black toners that have already been put to practical use, although the black coloring material that is the coloring agent absorbs the near-infrared region relatively well, the absorbed energy is still not sufficient. If the melting point of the binder resin is adjusted to this absorption level, the melting point will be lower, which may cause blocking between toners at room temperature, toner sticking to the carrier and deteriorating the developer, or the photoconductive However, if the melting point was increased to avoid this drawback, it would be possible to avoid the weak emission intensity of the xenon Franche lamp and the This is because there is a drawback that fixing failure occurs in the later stages of life.

(di) Purpose of the Invention The purpose of the present invention is to develop a color that can be put to practical use in 1-ner used for flash fixing in electronic FFJ method, in view of the above-mentioned desire to put into practical use the conventional unpractical products and the drawbacks of the already put into practical use. To provide a black toner with excellent I-toner and fixing properties.

(el Structure of the Invention The above object is based on the general formula (where X is hydrogen, a halogen group, or an alkyl group, n
is an integer of 1 to 4, M is a monomer, a cohal-11, a palladium or a platinum atom, and A represents a quaternary ammonium group. This is achieved by using electrophotographic toner.

Since the benzenedithiol-based metal complex has extremely low absorption of light in the visible region and has a maximum absorption wavelength in the near-infrared region of around 900 nm, the electrophotographic toner containing the same has a black hue. Even if it does not contain xenon, it absorbs light energy in the near-infrared region where the emitted light intensity of xenon flash lamps is high, and it does not change the color tone of the coloring agent, so xenon is included in the electrophotographic method. It becomes possible to obtain a color 1-toner that can be practically used for xenon flash fixing using a flash lamp, and even in the case of a black toner, the absorption in the near-infrared region is improved compared to the conventional one, and the fixing performance is improved.

Typical examples of the benzenedithiol-based metal complexes include the following, all of which produce practical effects when the content in the electrophotographic toner is 5% by weight or less.

■ Bis(1,2-dithiophel-11nickel(II)
) Tetra-n-ethylammonium■ Bis(1-methyl-3,4-sithioferrate)nickel(II)tetra-n-butylammonium■ Bis(I,4-dimethyl-2,3-dithioferrate)nickel (■) Trimethylcetylammonium■ Bis(1,2,3,4-tetramethyl-5゜6-sithioferto)nickel(II)tetra-n-butylammonium■ Bis(1-chloro-3,4-dithio Ferrate)
Nickel (n)tetra-n-butylammonium■ Bis(1,2,3,4-tetrachloro-5゜6-dithiophel-1.)nickel(II)tetra-n-butylammonium■ Bis<1. 2.4-1-Rif1Corot5,6-dithioferto)nickel(ll)tetra-n~butylammonium■ Bis(1,4-dichlorol:l-5,6-dithiofer-1.)nickel(ll)tetra-n~butylammonium■ 11) Tetra-n-butylammonium ■ Bis(1-chloro-5,6-sithioferto)nickel (n) Tetra-n-butylammonium [Phase] Bis(1,2,4-tribromo-5, 6-Sithioferte) Nickel (1) Tetra-n-Butylammonium Binding material constituting the electrophotographic toner 8J) As the fingers, commonly used polymeric substances can be used, such as polystyrene, styrene and acrylate. Alternatively, copolymers with methacrylate, polyester resins, epoxy resins JJIi, polyamide resins, etc. may be mentioned.

In addition, for color toners, quinacridone-based and rhodamine-based red hues, copper phthalocyanine-based and triphenylmethane-based blue colorants, and hengedine-based yellow colorants can be used. As before, a black coloring material such as carbon blank or nigrosine dye may be used.

Furthermore, if necessary, an alloy dye, a fatty acid ester, a compound containing an amino group, etc. may be added as a charge control agent.

The electrophotographic toner can be produced by a conventionally known method. That is, the binder resin, the coloring material, the benzenedithiol-based metal complex and, if necessary, the charge control agent are kneaded and melted using, for example, a pressure kneader, a roll mill, an extruder, etc., and uniformly dispersed. After kneading, the cooled toner mass is pulverized using, for example, a pulverizer or jet mill, and then classified using, for example, an air classifier to obtain a desired toner.

(fl Examples of the Invention The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto.

[Example of color toner]

This example is an example of the color toner contained in the color toner.

The composition shown in Table 1 was kneaded for 1 hour in a pressurized kneader at 100°C, cooled and assimilated, coarsely ground in a grinder, and then finely ground in a Gen mill. A blue toner with a size of 5 to 20 μm was obtained by classifying the powdered powder using an air classifier.

-1-Is it one color? 111's WΩ-epoxy 4L oil 95 (Ebiclone 4o61, Dainippon Ink Kagaku Kogyo Zen) Copper phthalocyanine 3 (Lionol Blue ES, Toyo Ink! > Benzenedithiol metal complex 2 [Bis(1,4-dichloro) -5,6-cythiofert)nickel(II)tetra-n-butylammonium] In Table 1, epoxy 4fl (the fat is a binding 4M fat, and the phthalocyanine is a coloring agent and a charge control agent. be.

Add this toner to 5% volume and use iron powder (EF) as a carrier.
V250 (manufactured by Nippon Steel Powder) was prepared as a developer at 95% by weight, and the F6 adopted a xenon flash fixing method.
A fixing test was conducted using a 715D laser printer (Fujitsu'M).

The setting conditions for the fixing device were such that a capacitor with a capacity of 160 μF was used, the charging voltage was varied in the range of 1000 to 2000 V, and this was applied to a xenon Franche lamp.

In addition, to evaluate the fixability, lightly apply adhesive tape (Scotch Mending Tape, Sumitomo 3M?J:M) on the surface of the fixed image, and move a cylindrical block of steel with a diameter of 100 mm and a thickness of 20 mm in the circumferential direction at a constant speed. The tape was rolled on the tape to bring it into close contact with the recording paper, and then the tape was peeled off and the amount of 1-ner adhering to the tape was visually judged, and when there was no adhesion, it was considered to be completely fixed. .

As a result, the voltage applied to the xenon flash lamp was the maximum of 2000 V, and the fixation was complete, which was within the practical range.

In order to compare this result with the case in which the benzenedithiol-based metal complex was not contained, blue L-ner We conducted a retention test. The results show that the applied voltage was increased to the maximum of 2000
Even at V, no fixing occurred at all, and even after repeating the fixing operation 10 times at 2000 V, the fixing was only about 50%.
It was of no practical use at all.

-2-'Color 1.--No.1''-side and plate marks'' Positive XL epoxy resin 97 (Epicron 4061, manufactured by Dainippon Ink Chemical Industries) Copper phthalocyanine 3 (Lionor Blue ES, Toyo Ink Alliance) , in order to reduce the difference in tone between the blue toner Examples and Comparative Examples, 5.
The Munsell value was measured using an M color computer (model 5M-3-3C11, manufactured by Suga Test Instruments).

The measurement sample was prepared by placing the toner in a standard 400 sieve sieve, dropping a certain amount of the toner onto recording paper using an ultrasonic vibrating sieve, and heating the recording paper to melt and solidify the toner.

As shown in Table 3, the measurement results show that, when the brightness is kept constant, the hue and saturation of the examples differ from those of the comparative examples, but the differences are so small as to pose no problem in practical use. Therefore, it can be seen that there is almost no change in color tone even when the benzenedithiol-based metal complex is added, and in combination with the above-mentioned fixing properties, the color toner for xenon flash fixing can be put to practical use.

3 Munsell El Lightness Hue Saturation Example 4.0 1.7PB 10.3 Comparative Example 4.0
” 3.1P8 12.0 Furthermore, the spectral absorption characteristics of the benzenedithiol-based metal complexes in Table 1 and the toners of Examples and Comparative Examples were measured using a spectrophotometric needle (Model 330, Hitachi M). The results are shown in Figures 3 and 4. It shows that the absorption of the benzenedithiol-based metal complex is overwhelmingly large in the near-infrared region and extremely small in the visible region. The major difference between the comparative example and the xenon Franche lamp is in the near-infrared region, which shows the strongest emission intensity. Judging from the characteristics shown in Figure 3, it is clear that this is due to the effect of the benzenedithiol-based metal complex. The color toner according to the invention clearly shows that xenon flash fixing is possible.

[Example using black toner]

This example is an example using black toner.

The composition shown in Table 4, which is an example of the present invention, in which the benzenedithiol-based metal complex is added, and the comparative example shown in Table 5, in which the benzenedithiol-based metal complex is replaced with a binder resin, for comparison. A black 1-toner was prepared with the same composition as in the above-mentioned color toner examples, and a fixing test was conducted.

In addition, in Table 4, the epoxy resin is a binder resin,
The carbon blank is a colorant, and the nigrosine dye is both a colorant and a charge control agent.

4 31 To - (717i Italy (Evening 1AJLn'
(-”%) □-Eboxy resin 90 (Epicron 4061, Dainippon Ink Chemical Industry Association) Carbon black 5 (Blank Pearls, manufactured by Cabo Nodo Co., Ltd.) Nigrosine dye 3 (Oil Black BY, manufactured by Orient Chemical) Benzenedithiol System metal complex 2 [Bis(1,4-dichloro-5,6-sithioferto)nickel(II)teI/cyn-butylammonium] Ratio of 5M color toner! 2nd edition plastic plates January %) -Epoxy resin 92 (Epicron 4061, manufactured by Dainippon Ink and Chemicals) Carbon blank 5 (Blasocvars, manufactured by Cabo Nodo Co., Ltd.) Nigrosine dye (Oil Black BY, manufactured by Orient Chemical) This result shows that the voltage for complete fixation is a comparative example The voltage was 1900V in the example, whereas it was 1300V in the example.

Therefore, the fixing performance of black toner is greatly improved by the present invention, and it becomes possible to take measures against the above-mentioned drawbacks that existed in the past.

(gl) Effects of the Invention As described above, the configuration of the present invention provides a color toner that can be used in practical use and a black toner with excellent fixing properties as a toner used for xenon flash fixing in electrophotography. This has the effect of making it possible to realize color printing and stabilize printing in the most desirable fixing method.

[Brief explanation of drawings]

Figure 1 is a diagram before fixing showing the fixing of toner by flash light (
al and the figure after fixation (BL, Figure 2 is a spectral distribution diagram of a xenon flash lamp, Figure 3 is a spectral absorption curve diagram of a benzenedithiol-based metal complex used in an example of the present invention, and Figure 4 is a h-color diagram. These are spectral absorption curve diagrams of Examples and Comparative Examples of the present invention in I. & J. In the drawings, 1 is toner, 2 is recording paper, 3 is flash light, and 4 is
For example, a fixed image is shown. 1llllji3 (b. Dormitory? Song 2) ゑ (7II town f-3 concave liquid chief (Asahicho ¥-4 song 1-rebellion)

Claims (1)

[Claims] The general formula is (where X is hydrogen, a halogen group, or an argyl group, n
is an integer of 1 to 4, M is a nickel, cobalt, palladium or platinum atom, and A is a quaternary ammonium group). Toner for electrophotography.