JPS63141074A - One component toner - Google Patents

Abstract

PURPOSE:To obtain a toner permitting simultaneous development, permitting also transfer to ordinary paper by the corona transfer method by constituting the toner comprising particles consisting of an insulative resin as base material wherein electroconductive fibers penetrate the particles and the ends of said fibers appear on the surface of the particles. CONSTITUTION:The toner 1 comprises insulative resin particles 4 contg. pigment 2, magnetic material 3, and other additives dispersed in said insulative resin 4, through which several numbers of electroconductive fibers 5 penetrate and a part of said fibers appear out of the surface of the particles. The insulative resin 4 to be used is pref. commonly used thermoplastic resin. The pigment 2 is pref. 1-3wt% carbon black. Suitable magnetic material 3 is conventional powdery magnetic body, pref. Fe3O4. Cellulosic or nylon fibers, etc. having 1-10<6>OMEGA.cm specific resistance are used for the electroconductive fiber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of monocomponent toners used in electrophotography.

[Conventional technology]

In recent years, various printing devices using electrophotographic technology have been put into practical use and used. To give an overview of the toners used in this technology, in the case of printing devices using the "Carlson process", insulating non-magnetic toners are used in two-component magnetic brush development method and float electrode effect development method (CFEED method). In the case of electrofax, conductive magnetic toner and the like are known. Recently, a method of forming an image by simultaneously performing exposure and development (hereinafter referred to as the "simultaneous method"), which has the potential of greatly simplifying the process, has been studied in various places. 155957. In this method, the optimal development method is considered to be a method in which a brush of conductive magnetic toner to which a bias voltage is applied is rubbed over the surface of the photoconductor during exposure, and the photoconductor acts as an insulator. (unexposed area) and when it acts as a conductor.
A difference occurs in the amount of charge injected into the toner in contact with the photoconductor surface due to the bias voltage, and this difference in charge amount becomes a difference in electrostatic adhesion force to the photoconductor surface, making development possible. There is.

[Problem that the invention seeks to solve]

However, due to the conductivity of the toner used in the simultaneous method,
The well-known corona transfer method had the disadvantage that sufficient transfer to paper could not be achieved because the charge on the toner was neutralized in a short relaxation time, resulting in the loss of residual charge and electrostatic adhesion to paper. .

An object of the present invention is to provide a toner which can be developed by a simultaneous method and which can be transferred to plain paper by a corona transfer method.

[Means for solving problems]

The one-component toner according to the present invention is characterized in that it has conductive fibers on its surface that penetrate particles made of an insulating resin as a base material, and that the toner has magnetism.

[Effect]

According to the above structure of the present invention, charge injection into the toner at the tip of the magnetic brush during development in the simultaneous method is performed by conductive fibers, and the electrostatic adhesion force to the paper during corona transfer is controlled by the pre-charged insulation. It can be made to take charge of the electric charge of the plastic resin.

[Example] FIG. 1 shows a cross-sectional view of a toner in an example of the present invention. In the toner 1 of the present invention, several conductive fibers 5 penetrate through 40 particles of insulating resin in which pigment 2, magnetic material 3, and other additives are dispersed, and some of the fibers are exposed from the particle surface. It has a structure where The insulating resin 4 is preferably a commonly used thermoplastic resin, such as polystyrene and its copolymers, polyester and its copolymers, polyethylene and its copolymers, epoxy resins, acrylates, and methacrylates. It is preferable to use acrylate resins, copolymers, vinyl resins, etc. alone or in combination.

As the pigment 2, it is preferable to use carbon black, spirit black, nigrosine, etc. in a range of 1 wt% to 5 wt%. As the magnetic material 3, it is preferable to use known basic powders such as triiron tetroxide, γ-ferric oxide, chromium dioxide, nickel 7-erite, and iron alloy powder. Furthermore, as other additives, fluidity improvers (Si02゜TLO2, etc.) (L 1 w
It is preferable to add it in a range of t% to 115 wt%. The conductive fiber 5 has a specific resistance IR・crIL~106ρ・
Alpha cellulose-based and nylon-based materials are used. Using the above raw materials, a toner having a diameter of 10 to 15 μm is produced through commonly performed cross-mixing, pulverization, and classification steps.

FIG. 2 shows how the toner of the present invention is used for simultaneous development. In the figure, the same elements as in FIG. 1 are given the same numbers. A photoreceptor 13 formed by laminating a photoconductor layer 10, a transparent conductor layer 11, and a transparent support layer 12 in this order receives image exposure 15 as it moves in the direction of an arrow 14. Due to the magnetic material dispersed in the insulating resin, the toner 1 is transferred to the insulating resin 4 by a well-known magnetic brush formed using a magnet roller 16 and a sleeve 17 or a charging blade and a charging device (not shown). After receiving the desired charge, it comes into contact with the photoconductor layer 10 at the exposed portion. Since a bias voltage 18 is applied to the sleeve 17, charges are injected into the toner in contact with the photoconductor layer through the conductive fibers 5, but the amount of charge is different between exposed and unexposed areas. As a result, a difference occurs in the electrostatic adhesion force of the toner to the surface of the photoconductor layer 10, and development is performed.

FIG. 3 shows how the toner in the present invention is transferred by the corona transfer method. In the figure, the same elements as in FIG. 2 are given the same numbers. A transfer paper 19 is placed on the developed surface of the photoreceptor 130, and ions having a polarity opposite to the surface charge of the insulating resin 4 of the toner 1 are injected from the back side of the transfer paper by a corona transfer device 20. At this time, the charges in the conductive fibers 5 injected during development are instantaneously neutralized and do not contribute to the transfer force to the transfer paper, while the surface charges of the insulating resin 4 have a long relaxation time, so they do not contribute to the transfer paper. The electrostatic force between them acts as a transfer force, and toner transfer is achieved.

[Example 1] Polystyrene resin (Styron, Asahi Kasei) was used as the insulating resin, and cellulose was used as the conductive fiber (length: 1 mm, specific resistance: 1 j?"l: 'm and 10' II @cru)
Using spirit black as a coloring agent, raw materials were weighed to give the composition shown in Table 1. Thereafter, the mixture is roughly mixed and kneaded using a screw extruder. The mixed material is coarsely pulverized to 01 to α5 length using a stamp mill, and the coarsely pulverized material is pulverized to 5 to 20 μm using a jet mill.

The toner was further classified to 10 to 15 μm using a dry sieve classifier to produce a toner.

Table 1 Next, development, transfer, and fixing were performed using the single-component toners of sample 7g61 to 6 by the simultaneous method, and a good fixed image could be obtained.

[Comparative Example 1] A toner having the composition shown in Table 2 was manufactured using the same raw materials and manufacturing method as in Example 1. 'Table 2 Next, using this sample/I67-11 single-component toner, development, transfer, and fixing were performed using the simultaneous method.
Sample/I67 could not be developed.

This is because the amount of conductive fibers is small and sufficient charge injection cannot be performed.

Sample/168 could not be transferred.

The reason for this is that the amount of insulating resin is small and cannot sufficiently hold the charge necessary for transfer. Sample 7169~
Scrap 11 could not be developed.

This is because the resistance of the fibers is high and sufficient charge injection cannot be performed.

[Example 2] Polyester (pylon 200°) was used as the insulating resin, nylon type (length 1 mu,
Specific resistance 142 @! and 10'J7@cm), using nigrosine as a coloring agent, the raw materials were weighed to have the composition shown in Table 5. Thereafter, a toner having a thickness of 10 to 15 μm was produced in the same manner as in [Example 1].

Next, using the one-component magnetic toners of Samples 412 to 17, development, transfer, and fixing were performed by a simultaneous method, and good fixed images were obtained.

[Comparative Example 2] A toner having the composition shown in Table 4 was manufactured using the same raw materials and manufacturing method as in Example 2.

Next, when the monocomponent toners of samples 71618 to 22 were used for development, transfer, and fixing by the simultaneous method, sample 418 could not be developed.

This is because the amount of conductive fibers is small and sufficient charge injection cannot be performed. Sample, %19, could not be transferred. The reason for this is that the amount of insulating resin is small and cannot sufficiently hold the charge necessary for transfer. Samples Nos. 20 to 422 could not be developed. This is because the resistance of the fibers is high and sufficient charge injection cannot be performed.

〔Effect of the invention〕

As described above, according to the present invention, since the toner used in electrophotography has conductive fibers on the surface that penetrate through the particles made of insulating resin, development is performed by the magnetic material in the toner. A magnetic brush and conductive fibers running through the toner form a conductive chain to inject charge, and a one-component toner can be realized that uses corona transfer using an insulating resin for transfer. Furthermore, since the one-component toner of the present invention has several fibers on its surface, it can intertwine with paper fibers and improve transfer efficiency. Therefore, if this toner is used in the simultaneous method, good transfer can be performed without being affected by humidity, and a printing device with a greatly simplified process can be realized.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a single-component toner according to the present invention, and FIG. 2 is a diagram showing how development is performed by a simultaneous method using the single-component toner according to the present invention. FIG. 3 is a diagram showing how the one-component toner according to the present invention is transferred by the corona transfer method. 1... - component magnetic toner 4... insulating resin 5... conductive fiber and above Applicant: Seiko Epson Corporation Figure 1 Figure 2

Claims (2)

[Claims] (1) A one-component toner used in electrophotography, which is characterized by having conductive fibers on its surface that penetrate through particles made of an insulating resin. (2) The one-component toner according to claim 1, wherein the toner is a magnetic toner.