JPS5926757A - color electrophotography method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to color electrophotography, and more particularly to a color electrophotography JIC development method that provides clear and wide range of color tones.

Conventionally, regarding electrophotography, U.S. Patent No. 2297
691 one 1, Yu 11842-2391゜, one 6,3
As described in Japanese Patent No. 343-24748, uniform electrostatic charge is applied to the photoconductive layer by corona discharge,
By exposing this to a light image corresponding to the original, the charge in the exposed portion is erased and a latent image is formed. Development is carried out by depositing a finely powdered electrostatic substance, so-called toner, on the obtained electrostatic latent image. The toner is attracted to the electrostatic latent image depending on the amount of charge on the photoconductive layer, forming a toner image with shading. This toner image is transferred to the surface of a support such as paper or cloth as necessary, and permanently fixed to the support surface (C) using an appropriate fixing means such as heating, pressure, solvent treatment, or overcoating. This toner image can also be fixed onto the photoconductive layer if it is desired to omit the transfer step.

There are many known methods for developing a developer. Examples include the cascade development method described in U.S. Patent No. 2,618,552, the magnetic brush method described in U.S. Pat. No. 2,874,063, the touchdown method described in U.S. Pat. Particularly typical developing methods are known as the cascade method and the magnetic plan method. The cascade method uses non-magnetic particles such as glass beads,
A fine powder toner is attached to the surface to form a developer. When this developer cascades over the surface of the photoconducting layer, which has electrostatic potential, the toner selectively adheres only to the charged portion of the electrostatic latent image, causing non-electrostatic latent images. Development is performed by not adhering to charged areas.

Further, the magnetic plan method uses magnetic particles such as steel and ferrite as carriers. The developer consisting of toner and magnetic V1-carrier is held by a magnet, and the magnetic field of the magnet arranges the developer in a plan-like manner.This magnetic brush absorbs the electrostatic charge on the photoconductive layer. When it comes into contact with the latent image surface, only the toner is attracted from the plan to the electrostatic latent image and develops.

Touchdown development involves carrying developer material by a support layer, such as a web or sheet, to a latent image-bearing surface to develop a static latent image.

j) The fJ;i/ls method can be used not only to obtain conventional black and white copies, but also to obtain multicolor copies. That is, first of all, light from the original is passed through a blue filter and exposed onto a photoconductive jfj, and this formed electrostatic latent image is supplemented with a filter, and similarly, a pre-latent image is passed through a green filter and a red filter. The fc latent images formed are then developed with magenta toner and cyan toner, respectively. The three colors of developed toner are transferred to the same support in sequence, and the final color copy is obtained with -1 fixing. Of course, the order of development in this color development method is.

Regardless of the above-mentioned order of yellow, maze/red, and cyan, changes can be made as appropriate.

In color electrophotography, which requires multiple development cycles, the color toner should have the following properties: (1) A transparent colored toner that does not interfere with the different colored layers beneath the toner layer; It is necessary that there be.

(2) Each toner must have sufficient hue and lightness, have a wide range of color mixing properties, and have a wide range of color tone reproducibility.

(3) When mixing colors, a combination of color toners must be selected that provides a deep black color that matches the black image of the original.

(4) The l·ner must have a desirable triboelectric charging property and fluidity as a true characteristic of l·ner.

(5) Caking or dumpling during handling or storage!
: JL must be a toner that does not collect and has good storage stability.

and so on.

However, it is difficult to obtain a conventional color toner that satisfies all of these requirements.

β・Rieba, l[η, proposed in Publication No. 49-46951, etc., has been proposed, and an appropriate coloring agent has been selected and applied to color electronic method A.

However, in most of these cases, when selecting a colorant, emphasis is placed on the hue, spectral reflection characteristics, and color tone of the C toner. On the other hand, if emphasis is placed on the electrophotographic properties of the toner, the result will be a toner with reduced brightness, poor spectral reflection properties, and narrow color tone reproduction.

In general, in color toners, the tonal characteristics and electrophotographic characteristics of the toner can be said to be two sides of the same coin.

In order to overcome these drawbacks, the present inventor 77, after extensive research, developed a preferred electrophotographic q! that has a wide range of color tone reproducibility. We have discovered a developing method using a color filter that has a characteristic of J.

That is, an object of the present invention is to provide a novel developing method using L-ner having favorable spectral reflection characteristics.

Another object of the present invention is to provide a developing method using a toner that exhibits good color mixing properties in the color mixture of -(yellow, magenta, and cyan) and provides a wide range of color tone reproducibility.

Another object is to provide a toner with sufficient triboelectric charging properties. ! ! The present invention provides an imaging method.

Another object of the present invention is to provide a new developing method using a toner that can withstand long-term storage and has good storage stability.

The feature is that the color toner consists of a binder resin and a 71"i colorant, and the colorant for yellow, magenta, and cyan color toners is C1.5olven.
t YeJgow 77 and C1, Di 5perse
YedAow164, C1,5olvent Red
52 and C1,5 oaven, tRed49.0 pieces,
The present invention provides a color electrophotographic development method using a combination of toner containing Pigrnent Blue 15.

The color toner in the present invention is easily dispersed or dissolved in the binder resin and has excellent hue and brightness. Using this toner, the spectral reflectance of an image copied in only a single color is as shown in FIGS. 1 to 3.

Still, the blue obtained by overlapping two color toners,
The spectral reflectance of the green and red images is preferable as shown in FIGS. 4 to 6, and a wide range of color tone reproducibility can be obtained by combining the three color toners.

The content of the colorant is preferably 0.1% by weight or more and 30% by weight or less based on the binder resin, and more preferably 0.5% by weight or more and 20% by weight or less.

Examples of the binder resin of the color toner used in the present invention include monopolymers of styrene and its substituted products such as polystyrene, polychlorostyrene, and polyvinyltoluene; styrene-P-chlorostyrene copolymers, and styrene-P-chlorostyrene copolymers;
Propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer (-), styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-
Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α chloromethyl methacrylate copolymer,
Styrene-acrylonyl-IJ copolymer, styrene-
Vinyl methyl ether co-ffi combination, styrene-vinylethyl ether copolymer% styrene-vinyl methyl ether co-ffl combination, styrene-butadiene co-rli
Styrenic copolymers such as styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer; polymethyl methacrylate-1-
, polymethyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polynisdel, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic resin Group hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, etc. can be used alone or in combination.

As the carrier used in the present invention, either a magnetic substance or a non-magnetic substance can be used. For example, iron, steel, γ-ferrite 13a-ferrite, S
Examples include r-ferrite and oxides of chromium, cerium, and magnesium, or zircon, silicon, and silicon dioxide; these substances are used in the form of particles of 20 to = 000 microns.

The present invention is not limited to the development method using a two-component developer, but also includes other known toners, -component magnetic toner, -component conductive toner, -component non-magnetic toner, and development methods using a microtoning method. This is possible for all developing methods including component toners.

If necessary, the toner of the present invention may be mixed with various additives such as a charge control agent, a lubricant, and the like.

In the present invention, the spectrophotometer used to determine the spectral reflectance σ1 is a Beckman spectrophotometer 1) K-2A type, and the concentration measurements in the examples were carried out using Kodak Lano's blue filter, green filter, and red filter, respectively. Den filter≠47. ≠58. A Macbeth reflection densitometer (manufactured by Macbeth Co., Ltd.) is used.

Misfire while referring to the drawing below! An example of the blade will be described.

First, with reference to FIG. 8, an example of a color electrophotographic copying machine to which the color photocopying method according to the present invention is applied will be explained.
do. The electrostatic latent image formed on the photosensitive drum 1 by a suitable means is made visible by the developer in the developing device 16-3, and the image 21 is transferred onto the transfer material held on the transfer drum 19 by the gripper 20. A developed toner powder image is transferred by a corotron. Further, as a second color, a developing device 16-,
The toner powder image developed by the developer contained therein is also transferred to the transfer material by the transfer corotron 21, and the third color is similarly transferred. In this way, the transfer drone 19 rotates a predetermined number of times while gripping the transfer material, and images of a predetermined number of colors are multiple-transferred.

[Actual I16'li] The developer in the first color developer 16-3, the developer in the second color developer 16-7, and the developer in the third color developer R5163 are shown in the table below. Example of the structure shown in Table 1 (All parts in the table indicate parts by weight) Table 1 The toner was manufactured by premixing the toner components shown in Table 1, kneading them with two rolls, and going through a coarse crushing and fine crushing process. Finally, a color toner of 5 to 20 t+ was obtained through a classification process.

This toner was mixed with carrier iron powder (manufactured by Nippon Steel Powder) to give a suitable toner concentration, and when the toner was dispensed with an NP-Rikiler copying machine (manufactured by Canon), very good color tone reproducibility was obtained. In addition, as a storage test, approximately 2
When the developer left for a month was printed using an NP-color copying machine, the same image as before storage was obtained.

Colored image obtained by the present invention, Preuci1
FIG. 7 shows the range of tones that can be expressed by the present invention and deviations from the ideal toner.

In this case, the ideal toner is a three-primary toner using a subtractive color process that covers one-third of the visible spectrum.
This refers to a toner that has uniform high absorption and does not absorb at all over the entire wavelength range that is absorbed by the other two toners, in other words, completely reflects it, so as not to cause any overlap of absorption A12. .

The Preuci6 color circle is a pie chart as shown in FIG. 7, and is often used to know the color reproduction area of set inks.

For example, according to The Science of Printing (edited by Printing and Publishing ψF Research Institute) written by Youshige Hase, it is stated that it can be obtained by the following method.

The color circle has hues - Y (yellow), M (magenta), and C (cyan) on the outer circumference, and its secondary colors B (blue) and G (
Green), R (red) is the scale, at this position, the outer periphery is the clearest and brightest color, and the turbidity increases towards the center UII
, Therefore, the center is black. Then, divide the middle of each into 100 equal parts.

The first step in using the color circle is to measure the density of the solid ink area. Namely, Y, M.

C ink to B (Latten 7 to 47), G (Latten 5
8), R (Ratten ytc 25 ), and calculations are performed using the highest concentration of each ink as H2
2 is determined as M and the lowest value as L, it is determined as follows.

Heat error (hue error) = 111 x 10 o line - L Misalignment/fness (turbidity) = circle x 100 chi T (In the present invention, monochrome yellow, maze 7, cyan,
Then, the superimposed two-color images of blue, green, and red were compared, and the density of this image was measured using a MacPeth reflection densitometer to determine the hue error and turbidity (Table 2), which was plotted on the color circle. is shown in Figure 7.

Table 2 When the toner shown in Table 3 was produced in the same manner as in the example to obtain a nonoraton toner, and the image was copied using an NP-color copying machine (manufactured by Canon), the image was inferior to the color tone reproducibility of the example.
The overall color tone was unbalanced. Also, as in the example, a storage test was conducted in parallel.

All toners other than cyan toner were unsuitable for copying because toner particles agglomerated together, so-called clumps were formed, and even when mixed with a carrier, a sufficient load 1'' could not be retained.

PreucN! The dashed line graph in FIG. 7 shows the color circle obtained for the comparative example, and compared to the example, the area of one color tone development was narrower and the color circle was less balanced.

[Brief explanation of drawings]

FIGS. 1 to 6 are graphs showing the spectral reflectance of the obtained images. FIG. 7 is a graph showing a color circle of Preuci J. FIG. 8 is a schematic sectional view showing an example of a color electrophotographic copying machine to which the color electrophotographic developing method of the present invention is applied. l Photosensitive drum. 10- Current unit. 19 Transfer drum. 20・Gripper-0 21・Transfer corotron. 22... Separation claw. Applicant Canon Co., Ltd.

Claims (1)

[Claims] CI-So7! as a colorant for yellow, magenta, and cyan color toners! vent Yellow 77 and CI. Di8 ■) else Yellow 164, C1,
5o71vent Red52 and C1,5odven
t Red 49, C1, Pigment Bj
Color electrophotographic development method using tue15.