JPS6340167A - Toner - Google Patents

Abstract

PURPOSE:To obtain a toner which permits utilization of both systems; development by electric charge injection and corona transfer by coating an insulating material on the surface of a conductive toner at <=2mum thickness and 10-90% covering rate. CONSTITUTION:The insulating material is coated on the surface of the conductive toner 1 essentially consisting of a binder resin, coloring material 3 and magnetic material 2 at <=2mum thickness and 10-90% covering rate. The insulating material to be used includes hydrophobic colloidal silica or fine silica particles. The coating is executed by coating said material on the surface of the toner 1 in hot gaseous flow or by a ball mill, etc., then removing the surface coating at need under or in ultrasonic oscillation or high-velocity gaseous flow. The injection of the electric charge to the toner 1 at the top end of a magnetic brush during the development by a simultaneous method is executed by the conductive material of the toner particles, and the electrostatic attraction force to paper at the time of corona transfer is born the electric charge of the insulating material on the preliminarily electrostatic cally charged toner particle surface.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to purchasing a of toner used in electrophotography.

[Conventional technology]

Conventionally, toners used in electrophotography are two-component m
Insulating non-magnetic toner in air-grain development method and float electrode effect realization iron method (FEED method), insulating magnetic toner in jumping development method, conductive EB toner in electrofax, etc. are known. It also has the potential to greatly simplify the process. A method of forming an image group by simultaneously performing exposure and development (hereinafter referred to as the "simultaneous method") has been studied in various places, and the first one was published in Japanese Patent Application Laid-Open No. 58-1539.
57 has been proposed. In this method, it is considered that the most suitable method is to scrape the surface of the photoconductor during exposure with a conductive toner brush to which a bias voltage is applied, and the photoconductor is There is a difference in the amount of light injected into the toner that is in contact with the toner surface due to the bias voltage between when it acts as an unexposed area (unexposed area) and when it acts as a 4-dimensional body (exposed area). The difference in charge amount becomes the difference in the electrostatic adhesion force to the surface of the light 4 camera body, making development possible.

[Problem that the invention seeks to solve]

However, due to the toner used in the simultaneous method, due to its conductivity, the charge on the toner is neutralized in a short relaxation time, and the residual charge is lost, resulting in electrostatic adhesion to the paper. 1. The disadvantage of the well-known corona transfer method is that it cannot transfer to paper adequately. had.

The purpose of the present invention is to create a toner that can be developed using a simultaneous method and that can be transferred to paper-saving paper using a corona transfer method. It is about providing.

[Means for solving the intermittent point 1r] The toner of the present invention has an insulating substance f on the surface of the conductive toner, which is mainly composed of a binder resin, a colorant, and a magnetic material.
It is characterized by coating with a thickness of 2 A m or less and a coating coverage of 10 to 90 cm.

In the simultaneous method, one structure of a toner that can be used is one in which an insulating material is broken on the surface of a primary toner. This utilizes the special properties of a tetraelectric material during development, and utilizes the electrostatic adhesion of a charged material during transfer.

In the toner of the present invention, the binder resin that can be used is a known styrene resin or its polymer polyester;
Polyethylene, polypropylene.

Acrylic resin, polyvinyl acetate, polyurethane.

Polyamide, epoxy resin, polyvinyl chloride, polyvinyl butyral, polyamide, rosin, modified rosin, terpene fat, phenol S+ fat, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin.

Chlorinated paraffin and the like can be used alone or in combination.

Furthermore, the toner of the present invention has a coloring effect of an auxiliary color and a charge i! ! For control purposes and for other purposes, known materials 1 such as carbon black, nigrosine, metal complexes, etc. can be used.

Further, in the present invention, EB powders include alloys and compounds of cobalt, nickel, manganese, etc., such as madanetite, hematite, and ferrite, which are known as EB powders, and other magnetic materials.

Further, examples of the insulating material used in the present invention include hydrophobic colloidal silica or silica fine particles. Is it on the surface of Sytoner in a hot air stream or in a ball mill? After overturning, the surface coating is removed by ultrasonic vibration or high-speed air flow, if necessary.

FIG. 1 shows the Sa of the toner in the present invention.

In the toner 1 according to the present invention, electrically insulating parts 5 are scattered on the surface of a conductive material 40 in which a tB magnetic material and a colorant 3 are dispersed.

In FIG. 2, the same elements as in FIG. 1 are designated by the same numbers. Photo-humiliation electric layer 6. Transparent 4-electric layer7. The photoreceptor 9, which is layered on 1'A of the bright support layer 8, is exposed to light 11 while moving in the direction of the arrow 10. Due to the fB nature of the toner, the toner 1 is removed by a well-known magnetic brush formed using a magnetic roller 16 and a sleeve 12.

After the insulating material 5 on the surface receives a desired charge by a sleeve 12 or a charging blade (not shown), it comes into contact with the photoconductor layer 6 at the exposed portion.

Since a bias voltage 13 is applied to the sleeve 12, charge is injected into the toner in contact with the photoconductor layer through the conductive material 42, but the amount of charge is different between the 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 6, and development is performed.

FIG. 3 shows how toner is transferred by the corona transfer method according to the present invention. Elements in FIG. 1 that are the same as those in FIG. 2 are given the same numbers. A transfer paper 14 is placed on the surface of the developed photoreceptor 9, and ions having a polarity opposite to the surface charge of the insulating material 5 of the toner 1 are injected from the back side of the transfer paper by a corona transfer device 15. At this time, the electric charges in the insulating material 4 injected during development are instantaneously neutralized and do not contribute to the transfer force to the transfer paper, while the surface charges on the insulating material 5 have a long relaxation time, so there is a gap between them and the transfer paper. Electrostatic force acts as a transfer force, and toner transfer is achieved due to the adhesiveness of the insulating material 5.

[Function] According to the above structure of the present invention, in the simultaneous method, charge injection into the toner at the tip of the magnetic brush is performed by the conductive Mt material of the toner particles, and the static charge on the paper during corona transfer is The electrical adhesion force can be caused by the electric charge of the insulating material on the surface of the toner particles, which is charged in advance.

[Implementation row]

This case will be explained in detail below according to the implementation sequence.

Example 1 Styrene-acrylic copolymer 100 parts EB material (0 magnetite) 90 parts carbon black
10 parts of the materials were mixed in a roll mill, coarsely pulverized in a stamp mill, finely pulverized in a jet mill, and particles with an average size of 10 μm were collected in an air classifier.

Hydrophobic colloidal silica (Aerosil R-972 average particle size 16'm μ) was added to the recovered conductive toner. t.

The mixtures were mixed in the proportions shown in Table 1, and the toner surface was coated in a hot air stream. The thickness of the coating layer is 16
After determining the cracking rate based on the area ratio on the photograph from a microscopic photograph of one surface in the range of ~25 mμ,
Two copy tests of 10,000 copies were conducted to determine the transfer efficiency. As shown in Table 1, when the surface coverage was around 100%, transfer by the simultaneous method was not performed, and when the surface coverage was below 11%, the transfer efficiency was reduced.

Table 1 Example row 2 Polyester resin 40 parts Polystyrene resin 40 parts Magnetic agent (magnetite) 80 parts Carbon black 10 parts The above materials were mixed in a screw extruder, coarsely ground in a stamp mill, and then put in a shelving mill. The powder was finely pulverized using an air classifier and particles with an average size of 10 μm were collected.
Hydrophobic colloidal silica (Aerosil R-972) was mixed with the collected conductive toner at the T ratio shown in Table 2,
The toner surface was coated in a hot air stream. The thickness of the coating layer ranged from 16 to 30-7 Lμ.

Table 2 Copy test? The results are shown in Table 2.

Transfer was carried out efficiently in the range of surface coverage of $90% to $10.

〔Effect of the invention〕

As described above, according to the present invention, the surface of the conductive toner mainly composed of the binder resin 1, the colorant and the magnetic agent is coated with an insulating substance 'f: 10 to 90% of the surface with a thickness of 2 μm or less. By coating at a high rate, development is carried out by toner conveyance by a magnetic brush using the plate rotation of the particles, and charge injection using the conductivity of the toner particles, and transfer is performed by transferring the toner to the insulating part on the surface of the toner particles. Since this is done by charging, it is possible to realize a toner that can utilize both charge injection development and corona transfer. When this toner is used in the simultaneous method, it is possible to realize printing and loading with good transferability and a greatly simplified process.

[Brief explanation of the drawing]

Figure vJ1 shows the [i?] of the toner in the present invention. FIG. 2 shows how the toner of the present invention is used for development by the simultaneous method. FIG. 3 is a diagram showing a die to which toner is transferred by a corona transfer method in the present invention. １・Toner・Toner 2 Fist --＠Return 3 Clear coloring material 4... e capital Note material 5... Insulating material 6... Light '4 Electric material first 7... Transparent conductor Lighting body J・Δ 8...Transparent support -'j 9...Photoconductor 1, (,)...13 Moving direction of light body 11...Kenpo exposure 121・Sleeve 1311・Fist bias voltage 14 Pot・Number transfer paper 15...Corona transfer machine 16...Magnetic roller and applicant Seiko Epson Corporation IDOBU- Figure 1 Figure 2

Claims (1)

[Claims] In toner used in electrophotography, an insulating material is coated on the surface of a conductive toner whose main components are a binder resin, a coloring material, and a magnetic agent with a thickness of 2 μm or less and a coverage rate of 10 to 90%. A toner characterized by: