JPS6063545A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain a color toner and a black toner improved in fixability, especially, flash fixability by incorporating a mercaptophenol type metal complex in the toner to enhance light absorptivity. CONSTITUTION:A toner contains a binder resin, a pigment, a magnetic powder, etc. and a mercaptophenol type metal complex represented by formula I or II in which M is Mi, Co, Pd, or Pt, and A is quaternary ammonium. Since this metal complex has high absorptivity of light in the near IR region emitted from a xenon flash lamp, etc., the toner is made easy to melt and a practicable color toner can be obtained. When it is added to a black toner, the toner is enhanced in fixability as compared with a conventional one.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a toner used for visualizing an electrostatic latent image in electrophotography, and in particular, toner that is fixed onto recording paper by optical fixation. Regarding toner for electrophotography.

(g)) 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 produces a photoimage on the insulating layer. partially removes the electrostatic charge by irradiating it to form an electrostatic latent image,
Fine powder called toner is attached to the remaining part of the static charge to form a toner image that visualizes the latent image (referred to as development), and after transferring the toner image to recording paper, the toner is transferred to the recording paper. Printed matter is obtained by fixing (referred to as fixing) on the paper.

The toner is a fine powder obtained by dispersing a colorant, a charge control agent, etc. in a binder resin made of a natural or synthetic polymeric material, and is pulverized to about 1 to 30 μm, and is usually made of iron powder, glass peas, etc. The toner is mixed with a carrier material (carrier) to form a developer and used for the development, but the toner image is formed only with the toner.

The fixing is to melt the toner of the toner image and fix it to the recording paper, and known methods include heat-pressure fixing, pressure fixing, solvent fixing, and optical fixing. Among these fixing methods, flash fixing, which is a typical optical fixing method, is a method in which the image is fixed by flashing light from a discharge tube such as a xenon flash lamp. ■ Since it is non-contact fixing, the image during development without degrading resolution.

■ 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.

However, only black toner has been put into practical use, and as office automation (OA) equipment has become increasingly color-based, color toner has become the most desirable fixing method. Early commercialization is desired.

(C1 Prior Art and Problems In FIG. 1, toner 1 is
The process of fixing to the recording paper 2 is as follows.

As mentioned above, when a toner image is transferred to the recording paper 2, the toner 1 adheres to the recording paper 2 as a powder as shown in Figure (a) and forms an image.For example, if you rub it with your finger, the image will be removed. It is in a state of collapse. Then, when the toner 1 is irradiated with flash light 3 from a discharge tube such as a xenon flash lamp, the toner 1 absorbs the energy of the flash light 3 and converts it into thermal energy, its temperature rises, it softens and melts, and adheres to the recording paper 2 . After the flash 3 ends, the temperature decreases and the image solidifies to become a fixed image 4 as shown in FIG. It becomes like this.

What is important here is that the toner 1 melts and adheres closely to the recording paper 2. To do this, the toner 1 must receive sufficient light, including the thermal energy that is dissipated into the outside world and is not utilized to increase the temperature. Energy needs to be absorbed from Flash 3.

Although the spectral distribution of a xenon flash lamp, which is generally 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 in the 800 to 800 range. Only in the near-infrared region of 1000 nlIl, other regions including the visible region of 400-800 n111 are relatively weak.

Therefore, from the viewpoint of fixability, it is desirable that the toner has good light absorption in the near-infrared region.

However, the polymeric substance that is the binder resin that forms the main component of the toner 1 may be, for example, polystyrene, a copolymer of styrene and acrylate or methacrylate, polyester resin,
Epoxy resins, polyamide resins, etc. are targeted, but all of them have extremely low absorption of light energy in the visible and near-infrared regions, and colorants other than black absorb in the visible region but in the near-infrared region. is small, and furthermore, the absorption in the near-infrared region by the charge control agent is also small, so the color toner made of a combination of these is hardly melted by irradiation with the flash light 3. For this reason, until now there was no practical color toner for flash fixing, but OAI#Il
As colored vessels are becoming more and more popular, it is hoped that they will be put into practical use as soon as possible.

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 lowered, 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 areas where the light emission intensity of the xenon flash lamp is weak and the This is because there is a drawback that fixing failure occurs in the later stages of life.

(d+ Purpose of the Invention The purpose of the present invention is to develop a color toner and fixing toner that can be put to practical use among toners used for flash fixing in electrophotography, in view of the above-mentioned desire to put into practical use the conventional products that have not been put into practical use and the drawbacks of the products that have already been put into practical use. To provide a black toner with excellent properties.

(61) Constitution of the Invention The above object is achieved by an electrophotographic toner characterized by containing a mercaptophenol metal complex.

According to the present invention, the mercaptophenol metal complex has the general formula (wherein M represents a nickel, cobalt, palladium or platinum atom, and A represents a quaternary ammonium group) or (wherein M represents a nickel , cobalt, palladium or platinum atom, and A represents a quaternary ammonium group).

These mercaptophenol-based metal complexes have extremely low absorption in the visible region of light and a maximum absorption wavelength of 1100 nm.
Since it exists in the near-infrared region around 0n, the electrophotographic toner containing it can absorb light energy in the near-infrared region, where the emission intensity of a xenon flash lamp is high, even when it does not contain a black colorant. Because it absorbs and hardly changes the color tone colored by the colorant, it becomes possible to obtain a color toner that can be used for xenon flash fixing using a xenon Franche lamp in electrophotography, and it is also possible to obtain a color toner that can be used for xenon flash fixing using a xenon Franche lamp in electrophotography. Also in this case, the absorption in the near-infrared region is improved compared to the conventional method, and the fixing performance is improved.

Typical examples of the mercaptophenol-based metal complexes represented by the above two general formulas are as follows, and all of them have practical effects when the content in the electrophotographic toner is 5% by weight or less. will occur.

[If the general formula is the former]

■ Bis(1-mercaptorate-2-naphthlate)
Nickel (II) tetra-n-butylammonium ■ Bis(1-mercaptolate-2-naphthlate)
Nickel (II) tetraethylammonium ■ Bis(1-mercaptolate-2-naphthlate)
Cobalt (II) tetra-n-butylammonium ■ Bis(l-mercaptolate-2-naphthlate)
Nickel (■) Trimethylphenylammonium■ Bis(1-mercaptolate-2-naphthlate)
Nickel (■) triethylamine ■ Bis(1-mercaptolate-2-naphtholate) nickel (II) diethylamine ■ Bis(1-mercaptolate-2-naphtholate) nickel (n) laurylamine ■ Bis(1
-mercaptorate-2-naphthlate)cobalt(I
[) Tetra-n-butylammonium■ Bis(1-mercaptolate-2-naphthlate)
Cobalt(If) diethylamine [phase] Bis(1-mercaptolate-2-naphthlate)cobalt(II)
Di-n-butylamine 0 bis(1-mercaptolate-2-naphtholate) nickel (■) Triethanolamine [if the general formula is the latter] ■ Bis(1-mercaptolate-2-ferrate)
Nickel (II) tetra-n-butylammonium ■ Bis(1-mercaptolate-2-ferulate)
Nickel (II) tetraethylammonium ■ Bis(1-mercaptolate-2-ferulate)
Nickel (II) tetramethylammonium ■ Bis(1-mercaptolate-2-ferulate)
Nickel (■) Trimethylphenylammonium■ Bis(1-mercaptolate-2-ferulate)
Nickel (■) Triethylamine ■ Bis(1-mercaptolate-2-ferulate) Nickel(II) Diethylamine ■ Bis(1-mercaptolate-2-ferulate) Nickel(II) Laurylamine 1 ■ Bis(1-mercaptolate) -2-ferrate)
Cobalt (If) tetra-n-butylammonium ■ Bis(1-mercaptolate-2-ferulate)
Cobalt(II) diethylamine [phase] Bis(1-mercaptolate-2-ferulate)Cobalt(II)
Di-n-7'thylamine 0 Bis(1-mercaptolate-2-ferulate) Nickel (■) Triethanolamine As the binder resin constituting the electrophotographic toner, commonly used polymeric substances can be used. For example, polystyrene, a copolymer of styrene and acrylate or methacrylate, polyester resin, epoxy resin, polyamide resin, etc. can be used.

In addition, for color toners, quinacridone-based and rhodamine-based red colorants, copper phthalocyanine-based and triphenylmethane-based blue colorants, and benzidine-based yellow colorants can be used. If so, black colorants such as carbon black or nigrosine dye may be used as usual.

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 colorant, the mercaptophenol-based metal complex and, if necessary, the charge control agent are cross-melted and uniformly dispersed using, for example, a pressure kneader, roll mill, extruder, etc.; ) The desired toner can be obtained by pulverizing the toner using a mill or the like and classifying it using, for example, an air classifier.

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

[Example of color toner]

This example is for a blue toner among color toners.

Example Tll is an example in which the general formula contains the former mercaptophenol metal complex.

3 2 The composition shown in Table 1 was kneaded for 1 hour in a pressure kneader heated to 100°C, cooled and solidified, and then coarsely ground in a grinder and further finely ground in a jet mill. The resulting fine powder was classified using an air classifier to obtain a blue toner with a size of 5 to 20 μm.

1 (1) -〇% Epoxy resin 95 (Epicron 4061, manufactured by Dainippon Ink and Chemicals) Copper phthalocyanine 3 (Lionol Blue ES, manufactured by Toyo Ink) Mercaptophenol metal complex 2 [Bis(1-mercaptolate-2- naphthlate) nickel (IF) tetra-n-butylammonium] In Table 1, the epoxy resin is a binder resin,
Copper phthalocyanine is a colorant as well as a charge control agent.

This toner was added to 5% by weight, and iron powder (EF) was used as a carrier.
A developer was prepared using 95 wt.

The setting conditions for the fixing device were as follows: 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 the xenon flash lamp.

In addition, to evaluate the fixability, lightly apply adhesive tape (Scotch Mending Tape, manufactured by Sumitomo 3M) to the fixed image surface.
Roll an iron cylindrical block with a diameter of 100 cm and a thickness of 20 cm over the tape at a constant speed in the circumferential direction to bring the tape into close contact with the recording paper, then peel off the tape and measure the amount of toner attached to the tape. was determined visually, and complete fixation was defined as no adhesion.

As a result, the voltage applied to the xenon flash lamp for complete fixing was 1900 V, which was within the practical range.

In order to compare this result with the case not containing the mercaptophenol metal complex, Comparative Example +1 shown in Table 2 in which the mercaptophenol metal complex was replaced with a binder resin.
A blue toner was produced in the same manner as in Example 1, and a fixing test was conducted. This result shows 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(l) -% Epoxy resin 97 (Epicron 4061, manufactured by Dainippon Ink & Chemicals) Copper phthalocyanine 3 (Lionol Blue ES, manufactured by Toyo Ink) In addition, Examples (11 and Comparative Example) both containing the same colorant In order to reduce the difference in color tone from (1), we used a 3M color computer (model 5M).
-3-5CH, manufactured by Suga Test Instruments), the Munsell value was measured.

The measurement sample was prepared by placing the toner in a 400-mesh standard 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 are as follows: When the brightness is kept constant, the hue and saturation of Example (11) differs from that of Comparative Example +11, but the difference is so small that it poses no practical problem. Therefore, even if the mercaptophenol-based metal complex is added, there is almost no change in color tone, and in combination with the above-mentioned fixing properties, it can be seen that the color toner for xenon flash fixing can be put to practical use.

3(1) and (1) Munsell Lightness Hue Saturation Example (1) 4.0 B, I B 8.0 Comparative Example (1)
14,03, IPR12,0 Furthermore, the mercaptophenol metal complexes in Table 1 and Examples (11, Comparative Examples (11)
The spectral absorption characteristics of each toner were measured using a spectrophotometric needle (Model 330, manufactured by Hitachi), and the results are shown in FIGS. 3 and 4. FIG. 3 shows that the absorption of the mercaptophenol metal complex is overwhelmingly large in the near-infrared region and extremely small in the visible region. Fourth
In the figure, the major difference between Example +11 and Comparative Example (1) is in the near-infrared region, showing that Example (1) absorbs the light energy of the xenon flash lamp well, which is the third It can be seen from the characteristics shown in the figure that this is due to the effect of the mercaptophenol-based metal complex, and clearly shows that the color toner according to the present invention is capable of xenon flash fixing.

Example (2) is an example in which the general formula contains the latter mercaptophenol metal complex.

With the composition shown in Table 4, a blue toner was manufactured in exactly the same manner as in Example (1) and a fixing test was conducted. As a result, the voltage for complete fixing was 2000 V, which was the same as in Example (1) It was within the practical range.Also, comparative example+ with the same colorant
In comparison of color tone with Example No. 11, although no data was presented, the difference was slight and did not pose a practical problem, similar to Example No. 11.

4 (2) - (% Epoxy resin 95 (Epicron 4061, manufactured by Dainippon Ink & Chemicals) Copper phthalocyanine 3 (Lionol Blue ES, manufactured by Toyo Ink) Mercaptophenol metal complex 2 [Bis(1-mercaptolate-2) -ferulate) nickel (II) tetra-n-8 butylammonium] [Example for black toner] The following example is for a black toner.

Example (3) is an example where the general formula contains the former mercaptophenol metal complex, and Example (4) is an example where the general formula contains the latter mercaptophenol metal complex.

Furthermore, in Comparative Example 12), the mercaptophenol metal complex was replaced with a binder resin for comparison.

For each of the compositions shown in Tables 5, 6, and 7, black toners were produced and a fixing test was conducted in exactly the same manner as in Example +1).

In these tables, the epoxy resin is a binder resin, the carbon black is a colorant, and the nigrosine dye is both a colorant and a charge control agent.

5 (3) % Epoxy resin 90 (Evicron 4061, manufactured by Dainippon Ink and Chemicals) Carbon black 5 (Black Pearls L1 manufactured by Cabot) Nigrosine dye 3 (Oil Black BY, manufactured by Orient Chemical) Mercaptophenol metal complex 2 [Bis(1-mercaptolate-2-naphtholate) nickel (II) tetra-n-butylammonium] 6 (41M! -〇 % Epoxy resin 90 (Evicron 4061, manufactured by Dainippon Ink and Chemicals) Carbon black 5 (Black Pearls, manufactured by Cabot) Nigrosine dye 3 (Oil blank BY, manufactured by Orient Chemical) Mercaptophenol metal complex 2 [Bis(1-mercaptolate-2-ferulate) nickel (If) tetra-n-butylammonium] 1 :3 7(2) -〇% Epoxy resin 92 (Evicron 406I, manufactured by Dainippon Ink and Chemicals) Carbon blank 5 (Black Pearls, manufactured by Cabot) Nigrosine dye 3 (Oil Black BY, manufactured by Orient Chemical) This result is , the voltage for complete fixing was 1900V in Comparative Example (2), 1200V in Example (3), and 1200V in Example (4).
), it was 1300 V. 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.

C. Effects of the Invention As explained above, according to the structure of the present invention, it is possible to provide a color toner that can be used in practical use and a black toner with excellent fixing properties among toners 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 (
Figure 2 is a spectral distribution diagram of the xenon flash lamp, Figure 3 is a spectral absorption curve diagram of the mercaptophenol metal complex used in Example (1), and Figure 4 is the diagram after fixation. It is a spectral absorption curve diagram of Example (1) and Comparative Example (1). In the drawing, 1 is toner, 2 is recording paper, 3 is flash light, 4 is
indicate fixed images, respectively. 2 Coil 1 Figure* 2 〆Unexamined Japanese Patent Publication No. 1997-63545 (7) Broom 3 Figure 400 500 6 (+1+ 7111+ &# l?
t) ρ 嵯ρ / IIθma & (1 graduate 4. creation (00 δO \ λ \ ward − 60′1 ＠+ ＼ ＼ Tsu [7) vine ry destination, 1 ko 7 to “[-1 ＼ ＼− ) (1j:

Claims (3)

[Claims] (1) An electrophotographic toner containing a mercaptopheno-JLt metal complex. (2) The mercaptophenol-based metal complex is characterized in that its general formula is represented by the following (where M represents a nickel, cobalt, palladium or platinum atom, and A represents a quaternary ammonium group). An electrophotographic toner according to claim (1). (3) The mercaptophenol-based metal complex is characterized in that its general formula is represented by the following (where M represents a nickel, cobalt, palladium or platinum atom, and A represents a quaternary ammonium group). The toner for electrophotography according to claim 11.