JPS6311949A - Toner for xerography - Google Patents

Abstract

PURPOSE:To enable development in a simultaneous development method and transfer to plain paper in a corona transfer method by consisting of the titled toner of resin parts A which have conductivity and do not mix with each other and resin parts B which have an insulating characteristic and are dispersed into the resin parts A. CONSTITUTION:The toner 1 has the structure in which the insulting resin parts 2 are dispersed into the conductive resin parts 3 without mixing the parts with each other. The insulating resin parts 2 consist essentially of a thermoplastic resin such as polystyrene, PE and acryl and oxide insulating magnetic powder such as Fe2O3 and gamma-Fe2O3 and also contain several % of pigment such as nigrosine, fluidity improving agent and electric charge controlling agent. The conductive resin parts 3 consist essentially of the thermoplastic resin having the thermal softening point lower by at least >=5 deg.C than the thermal softening point of the thermoplastic resin used for the insulating resin parts 2 and conductive magnetic powder or metal powder of Fe, Co, Ni, etc., and also several % of pigment such as carbon black, fluidity improving agent and electric charge controlling agent. The toner with which both methods of the development by the electric charge injection and corona transfer are utilizable is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to toners used in xerography.

[Conventional technology]

Conventionally, the toner used in xerography is 2.
Component magnetic brush effect realization method and float electric effect realization method (FE)
Insulating non-magnetic toner in the FJD method, insulating magnetic toner in the Jianbinge Genrin method, conductive magnetic toner used in electrofax machines, etc. h = 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, such as Japanese Patent Publication No. Showa 58
-153957 K proposed. In this method, it is believed that the optimal development method is to use a brush of conductive magnetic toner to which a bias voltage is applied to scratch the surface of the exposed photoconductor, and the photoconductor acts as an insulator. (exposure area), the amount of charge injected into the toner that comes into contact with the photoconductor surface due to the bias voltage t/- is generated, and the difference in the amount of charge t; Static electricity causes a difference in adhesion force, which makes development possible.

[Problems to be solved by the invention] However, due to the conductivity of the toner used in the simultaneous method, the IT charge of the toner is neutralized in a short relaxation time, and the heavy residual charge is lost and the toner is transferred to the paper. The known corona transfer method has the disadvantage that the transfer to paper is not sufficiently effective because of the loss of electrostatic adhesion.

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

[Means for solving open ends]

The toner in the present invention has conductivity that prevents them from mixing with each other! It is a sign that the resin part A has insulation properties and the resin part Bhi is dispersed inside the resin part A, and that it has reliability.

[Function] According to the above-mentioned structure of the great invention, charge is injected into the toner particles at the tip of the magnetic brush during development using the simultaneous method, and the charge is injected into the toner particles by the electroconductive resin part AK of the toner particles. The electrostatic adhesion to the paper during transfer can be caused by the charge of the insulating resin part B dispersed inside the pre-containing resin part A of the toner particles which have been charged in advance.

〔Example〕

FIG. 1 shows an embodiment of the toner according to the great invention. The figure shows toner l! Shows F1 side. 711. In the present invention, one toner is dispersed inside the insulating resin portion 2h and the conductive resin portion 3 without being mixed. .

Here, the insulating sIl1w part is made of two polystyrene e polyethylene/acrylic or other well-known thermoplastic resins.

The main ingredients are well-known oxide insulating magnetic powders such as lFe2O3 and γ-Fg203, and also contain pigments such as nigrosine, fluidity improvers, and charge control agents. In addition, the conductive resin part 3
A thermoplastic resin whose thermal softening point is at least 5°C lower than that of the thermoplastic resin used for the insulating resin in Section III, and a well-known conductive magnetic powder or metal powder such as Fg, an, Ni, etc. These separately prepared resin parts, which contain pigments such as carbon black, fluidity improvers, and charge control agents as main components, are kneaded and manufactured to be used at least in the conductive resin part 2. The temperature is set at a temperature higher than the softening point of the thermoplastic resin and lower than the softening point of the thermoplastic resin used for the insulating resin part 3, and crosstalk is carried out using a well-known crosstalk machine such as a screw extruder [7. Coarsely pulverize with a well-known device such as a crusher, then finely pulverize with a well-known device such as a jet mill, and if necessary, classify with a device such as a soft sieve classifier. Part 2 h;, conductivity 4! Toner particles 1^t can be dispersed inside the pilgrim 3 without mixing with each other, and have a thickness of 5 to 15 μm.

f$2 Figure K shows how development is carried out by the simultaneous method using the toner of the present invention. In the figure, the same elements as in Figure 1 are designated by the same numbers hi. Photoconductor layer 4, transparent conductor layer 5. When the transparent support layer 6 is laminated in this order and the photoreceptor 7 moves in the direction of the arrow 8, it receives image exposure 9.

Due to the magnetism of the toner, a well-known magnetic brush formed using a magnet roller 11 and a sleeve 12 is used to remove one toner and the inside of the gauze resin. The sleeve 12 receives a desired charge from the blade and is vertically connected to the photoconductor layer 5 in the exposure area.Since a bias voltage of 13hS is applied to the sleeve 12, the toner in contact with the photoconductor layer is Charge hZ is injected through the conductive resin part 3 surrounding the particles, but the injection 'Jl is different between the exposed area and the unexposed area,
As a result, a difference occurs in the electrostatic adhesion of the toner to the powder surface of the photoconductor layer 12, resulting in a difference in the electrostatic adhesion of the toner to the powder surface of the photoconductor layer 12.

FIG. 4 shows how toner is transferred by the corona transfer method according to the present invention. In the figures, the same elements as in Figures 1 and 3 are numbered the same.

It is. A transfer paper 14 is placed on the surface of the photoreceptor 70 which has been washed, and a corona transfer device 15 injects iodine having a polarity opposite to the surface charge of the insulating resin portion 20 of the toner 1 from the back side of the transfer paper. At this time, the charges in the conductive resin part 3 injected during development are instantaneously neutralized and do not contribute to the transfer force to the transfer paper, while the charges on the surface of the insulating resin part 2 have a long relaxation time. Electrostatic force ^ acts as a transfer between the paper and the eave ceiling paper, and the toner transfer is guided.

〔Effect of the invention〕

As described above, according to the present invention, the toner is dispersed within the conductive resin part and the conductive resin part so that the toner does not mix with each other; Moreover, due to the reason that the IR material is magnetic, it is carried out by utilizing the magnetism of the particles, transporting the toner by a magnetic brush, and injecting electric charge into the toner by the conductive resin part of the toner particles.

Since the transfer is performed by electrostatic charge on the IP edge resin surface of the toner particles, it is possible to realize a toner that can utilize both charge injection development and corona transfer methods. If this toner is used in the simultaneous method, a printing device with good transferability and a simplified wide-width process can be realized.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the toner according to the present invention. FIG. 2 is a diagram showing how a head image is created by the simultaneous method using the toner according to the present invention. FIG. 3 is a diagram showing how toner is transferred by a corona transfer method in the present invention. 1... Fist toner 2... Insulating resin part 3... Conductive resin part and above

Claims (3)

[Claims] (1) In a toner for xerography, a conductive resin part A that does not mix with each other and the resin part A
A toner for xerography, characterized in that a resin part B having an insulating property is dispersed inside the toner and has magnetism. (2) The resin part A and the resin part B have a volume resistivity ratio of 10^2 (Ωcm) or more, and the softening points of the resins of the resin part A and the resin part B are at least The toner for xerography according to claim 1, characterized in that the difference is 5° C. or more. (3) The resin part B is dispersed inside the resin part A using a kneader, and the toner particle size is adjusted to 5 to 15 μm. Toner for xerography.