JPS63244050A - Toner - Google Patents

Abstract

PURPOSE:To obtain a clear transfer image of a conventional paper by incorporating a spherical particle contg. an electrically conductive fine particle as a main component in a thermoplastic elastomer. CONSTITUTION:The toner 1 comprises the thermoplastic elastomer 4 as a binding resin, and has a structure of dispersing the electrically conductive spherical particle 3 together with a magnetic powder 2 in the toner, and coating thinly the surface of the toner with an insulating spherical fine particle 5. The binding resin is preferably composed of a material which is a soft and has elasticity at ordinary temp. and becomes soft at the temp. of about 10 deg.C. The electrically conductive spherical particle 3 preferably contains 1wt.%-15wt.% the spherical particle which contains a carbon black as a main component, and has the particle size of 2-3mum. Thus, the image can be formed by a simultaneous method, and the transfer of the image to the conventional paper can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a toner used in a recording device applying an electrophotographic method.

[Conventional technology]

Output of image information in recent years! ! Printing devices using electrophotographic processes, which are capable of low-noise, high-speed printing, are attracting attention. Recently, it has the potential to greatly simplify the process.

A method using new xerography technology that creates a painter by simultaneously performing exposure and painting (hereinafter referred to as the simultaneous method)
are being considered in various places. (Japanese Patent Publication No. 58-153
957) In this method.

The most suitable method is currently considered to be a method in which a toner brush applied with a bias voltage during exposure is used to rub the surface of the patterned body containing the photoconductor layer. There is a difference in the charge '11 injected into the toner in contact with the surface of the painter's forming body due to the bias voltage when it acts as an insulator (unexposed area) and when it acts as a conductor [jl light area]. The difference in charge amount of 1 m is due to the difference in electrostatic adhesion force to the surface of the forming body, and it is possible to selectively form toner in the bath.

However, when using a conductive toner, due to its conductivity, the charge on the toner is neutralized in a short relaxation time, causing the toner to lose its residual charge and lose its electrostatic adhesion to paper. The electrostatic transfer method cannot transfer the image to paper sufficiently, and the method using a transfer roller or the like has the disadvantage that the process becomes complicated.

In order to improve these drawbacks of the simultaneous method, a method using pressurized MT is being considered, as proposed in Japanese Patent Application No. 61-235706, for example, and the development of toners for this purpose is progressing.

This uses a toner made of conductive fine particles dispersed in a binder resin whose main component is a thermoplastic elastomer, and when the toner is pressurized, the shape of the toner changes, causing the conductive fine particles inside to become densely packed. As a result, a conductive chain is formed inside the toner, and the specific resistance of the toner itself is reduced. As a result, free charge is injected and a formation is formed on the surface of the photoreceptor. By not applying pressure during transfer, the insulating properties of the toner itself make it possible to transfer to plain paper using an electrostatic transfer method.

[Problem that the invention seeks to solve]

However, a structure in which ordinary conductive fine particles are simply dispersed in a binder resin has the following problems.

1. It was difficult to uniformly disperse the conductive particles, and uneven printing of the conductive particles resulted in hollow spots and low contrast.

2. As a result of being dispersed throughout the spherical particles, pressure controllability is lacking, and the pressure is 1 to several f/cW1'' in the developing sleeve.
It is inferior in that conductivity can be established by the pressure of This situation was occurring.

Therefore, the present invention aims to solve these problems.
The purpose is to provide a toner for use in printing devices utilizing the simultaneous process. Specifically, it is an object of the present invention to provide a toner that can form an image in a simultaneous method and that can be transferred to plain paper.

[Means for solving problems]

The toner according to the present invention is characterized in that spherical particles containing conductive fine particles as a main component are contained in a thermoplastic elastomer.

[Effect]

Conductor 1+1 with a size of about ⅇ to A relative to the toner diameter
By adopting a structure in which several to dozens of 100% spherical particles are contained in the binder resin, conductive chains in the toner are difficult to form under minute pressure, and even if the particles come close to each other, If the contained particles do not approach each other as a whole, there will be a rapid induction YII.
Since the conductivity is not in the direction of the L ratio, the conductivity can be obtained in accordance with the pressure.

In addition, by including conductive spherical particles with a certain size, the probability that each will come into contact with each other due to volume deformation due to pressure application increases, making it easier to determine the conductivity at a given pressure. It can definitely be done.

[Implementation row]

Actual column l FIG. 1 shows the cross-sectional S structure of the toner according to the present invention.

The toner 1 of the present invention has a structure in which a thermoplastic elastomer 4 is used as a binder resin, conductive spherical particles 3 are dispersed therein together with magnetic powder 2, and the surface of the elastomer 1 is thinly coated with insulating spherical fine particles 5. The binder resin is preferably a material that is soft and elastic at room temperature and softens at around 100°C, such as BVh@ resin, polyurethane, styrene-butadiene copolymer, polyester and its copolymer, polyethylene and its copolymer, etc. As the 1Mi powder 2, which is preferably used alone or in combination in a range of 40 wt% to 6 Dwt% based on the total amount of the toner, known magnetic powders such as triiron tetroxide, r-ferric oxide, and chromium dioxide are used. , 30wt% to 80wt of nickel 7-elite, iron alloy powder, etc.
It is preferable to use it within the range of qII.

As the conductive spherical particles 3, spherical particles having a size of 2 to 3 μm and containing known carbon black as a main component are used at 1 wtTo.
It is preferable to contain 15 wt%.

Next, a method for producing the toner will be described.

First, conductive spherical particles having a size of about 2 to 3 μm are manufactured by fPFh. rF, the manufacturing procedure is as shown below.

1. Weigh hydroxyethyl cellulose and carbon black so that the weight ratio is l=1.

2. Dispersion M was prepared so that the concentration of hydroxyethyl cellulose was 2%. Water was used as the solvent in this case.

3. The sample was dispersed for 5 hours using a vibration disperser.

4. Spray the sample using the spray drying method to obtain a sample with a size of 2~
Spherical particles of 3 μm were produced.

5. The remaining moisture in the spherical particles was removed by using a hot air dryer.

Next, as a thermoplastic elastomer, HR5041 manufactured by Asahi Kasei was used.
Prepare a solution of this in xylene. A sample was prepared by mixing triiron tetroxide as an a-type powder and the above-mentioned carbon black-containing particles as conductive particles.
The ingredients of the food were as follows.

HR5041...60% by weight? '$, O,...O...Weight % Conductive particles No....1O weight The sample was dispersed using a vibration disperser, and then spherical particles of about 10 μm were prepared by spray drying.

Residual moisture was removed from the obtained toner using a hot air dryer.

Further, 11 parts by weight of insulating spherical particles 5 were mixed with 100 parts by weight of the above toner in a ball mill, and the mixture was sphericalized using a flash dryer. As the insulating particles 5, colloidal silica, hydrophobic silica, polyvinylidene fluoride fine particles, etc. can be used.

FIG. 2 shows how the toner according to the present invention is used for simultaneous development.

The toner transferred from the toner supply device onto the magnetic sleeve is crushed by the blade 11 and subjected to volumetric deformation as it passes through the gap between the magnetic sleeve and the two photoreceptors, which is controlled to be about 1 to 21 degrees above the magnetic sleeve. As a result, a conductive chain is formed in the cytochie and charge injection takes place. Photoconductive layer 6. Transparent conductor layer 7. The photoreceptor formed by laminating the transparent support layer 8 in this order is exposed to light as it moves in the direction of the arrow. At this time, if a bias voltage is applied between the sleeve and the photoconductor, the toner in contact with the photoconductor layer will undergo volume deformation, and the toner in contact with the photoconductor layer will undergo conductive conductivity formed by the volume deformation. Charge injection occurs through the chain and development occurs.

Regarding transfer, while the photoreceptor belt is rotating, the pressure on the moat-formed toner is released, and the conductive chains inside the particles are broken, forming insulating particles, and the effect of the anti-fik coating on the surface also overlaps. The injected charge is retained, allowing electrostatic transfer to plain paper using normal transfer processes.

Subsequently, the image is permanently fixed to the paper by heat fixing using a heat roll.

A4 size continuous copy test 1 using toner according to the present invention
After repeating this process 10,000 times, clear fixed iron was obtained with good reproducibility. This shows that charge injection and transfer were carried out in accordance with the above model using the pressure-sensitive type toner of the present invention.

Example 2 When producing the toner of the present invention, the resin for forming the spherical particles containing the X-conducting fine particles may be any resin as long as it is not attacked by the solvent that dissolves the thermoplastic elastomer that is the binder resin of the toner. Preferably, one that also has elasticity is selected.

This time, Milastomer (manufactured by Tamashi Petrochemical Co., Ltd.), which is dissolved in toluene, was used as the binder resin for the conductive fine particles, and l1R5041, which was dissolved in hot xylene, was used as the binder resin for the toner.

The manufacturing method was the same as in Example 1. By using an elastic elastomer for both resins, resistance changes due to pressure during development and transfer can be accurately controlled and device design is facilitated.

The printing results now have clear edges on both sides with good reproducibility.

〔Effect of the invention〕

According to the above-described tilK present invention, by having a structure in which spherical particles mainly composed of conductive fine particles are contained in a thermoplastic elastomer, the toner exhibits a resistance change according to the applied pressure. It has become easier to control the conductivity of toner during development and transfer. Therefore, clear transferred images on plain paper can be obtained with good reproducibility.

As a result, if the toner according to the present invention is used in the simultaneous method, it is possible to realize a printing device with a greatly simplified process, which has a great effect on miniaturization and cost reduction.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the cross-sectional structure of the toner according to the present invention. FIG. 2 is a diagram showing the process of developing using toner according to the present invention. 1. Toner 2. Magnetic powder 3 Life conductive spherical particles 4. Thermoplastic elastomer 5. 9 insulating spherical particles 11. Magnetic sleeve 11. Blade and above Applicant Seiko Epson Corporation Agent Patent attorney Tsutomu Mogami and one other person Figure 1

Claims (2)

[Claims] (1) A toner characterized in that spherical particles containing conductive fine particles as a main component are contained in a thermoplastic elastomer. (2) Claim 1, characterized in that the spherical particles mainly composed of conductive fine particles have a size of 1 to 5 μm.
Toner described in section.