JPH04161360A - Ion generating device for electrostatic recording and manufacture thereof - Google Patents

Abstract

PURPOSE:To form a dielectric layer having uniform quality and thickness by making a first electrode sheet coated with emulsion type dielectric paste rotate centrifugally, layering a second electrode sheet on the coated layer, connecting with pressure and patterning them so as to form first and second electrodes. CONSTITUTION:For dielectric paste, for example, surface of inorganic fine powder having a large dielectric constant is emulsified in water including surface active agent, of which a predetermined quantity is mixed uniformly into vehicle for emulsion painting. A copper sheet for a first electrode is coated with the dielectric paste and defoamed by a centrifugal separator so as to form a dielectric layer 2 having a uniform thickness. A copper sheet for a second electrode 3 is layered on the dielectric layer 2, pressed with heat, and fixed. Next, the copper sheets for the first and second electrodes 1 and 3 are patterned by etching at the same time or one by one, so that an ion generator which works as an electrostatic record head is obtained. Thus, a dielectric layer having uniform quality and thickness is formed and print images having high precision can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ion generator for ion flow electrostatic recording, and in particular to an ion generator for ion flow electrostatic recording used in electrostatic printing and copying. This invention relates to a device and its manufacturing method.

[Prior Art] A technique generally called electrostatic recording method includes a method in which a needle-like electrode is applied to a dielectric layer and a high voltage recording signal is applied to form an electrostatic latent image on the surface of the dielectric layer. , - A recording head consisting of a dielectric layer sandwiched between a pair of electrodes is placed a little apart from the dielectric layer on the substrate, and this recording head controls the corona ion flow on a pixel by pixel basis, thereby creating a non-contact state. There is a method in which an electrostatic image is formed as dots on the surface of a dielectric layer on a substrate. Of these, the latter method using a corona ion flow is described, for example, in Japanese Patent Publication No. 57-501348.

Although this method using corona ion flow is an effective method for electrostatic recording, it has the drawback that the dot size varies with the currently manufactured recording heads, making it difficult to obtain highly accurate images. There is. This is thought to be due to nonuniform film thickness and internal composition of the dielectric layer of the recording head, and the presence of defects (air bubbles, solvent vapor bubbles) in the ion-generating portion of the dielectric layer. .

It has been proposed to use a mica thin film as a dielectric layer with a homogeneous and uniform thickness, but it is difficult to obtain a thin film with the width of a recording paper, is expensive, and does not adhere well to the electrodes.
For other reasons, such as difficulty in processing, paste-like paints (dielectric paste) in which dielectric powder is dispersed have come to be used.

[Invention or problem to be solved] Dielectric paste has many advantages such as adhesion, cost, and the ability to form a free shape, but it also has various difficulties in forming a uniform film. There is.

That is, the dielectric paste is made by uniformly suspending dielectric powder in a vehicle made of an organic compound. The blending amount of the dielectric powder in the dielectric paste is as high as 50 to 809 degrees, so that the liquid must be dense and highly viscous. Therefore, most dielectric pastes are highly thixotropic and are very difficult to handle.

Further, the dielectric paste is usually formed as a thin film on the electrode by screen printing or die printing. Bubbles are trapped inside the dielectric paste when it is stirred and mixed or printed, but these bubbles hardly rise to the surface when left standing, and it is extremely difficult to remove the bubbles, so they remain fixed inside. .

Furthermore, unevenness on the underlying electrode surface, uneven mixing of the dielectric paste, viscosity changes due to the thixotropic nature of the dielectric paste, non-uniformity in the dielectric layer due to differences in printing pressure, and non-uniform film thickness may occur due to neglect. To be leveled <
(1o Therefore, when the entire surface is wet immediately after printing, even if it appears to be printed with a uniform thickness,
After drying and solidifying, fine irregularities, surrounding embankments, and variations in thickness between the printing start and end points occur.

The present invention was made in order to solve the above problems, and it is possible to form a dielectric layer that is substantially homogeneous and has a uniform thickness, thereby making it possible to form a static dot latent image with high precision. A method of manufacturing an ion generator for electrographic recording is provided.

[Means for Solving the Problems] The present invention includes a step of dispersing an emulsion type dielectric paste in which dielectric powder is dispersed in a paint vehicle on one side of a first electrode sheet, A step of centrifugally rotating the applied first electrode sheet, a step of placing a second electrode sheet on the coating layer and pressure bonding, and a step of applying the first and second electrode sheets to a predetermined pattern. Provided is a method for manufacturing an ion generating device for ion flow electrostatic recording, which includes the step of patterning to form first and second electrodes.

After drying the coating layer after centrifugal rotation, the surface of the coating layer can be activated by treating the surface of the coating layer with a solvent or by heat-treating the surface of the coating layer after centrifugal rotation.

Further, the present invention provides an ion generating device for ion flow electrostatic recording in which a dielectric layer in which dielectric powder is dispersed is interposed between a first electrode and a second electrode, wherein The dielectric powder is highly concentrated on the first electrode side and on the second electrode side.
Provided is an ion generating device for ion flow electrostatic recording, which is characterized by a low concentration on the electrode side of the ion flow.

The dielectric paste used in the present invention is prepared by treating the surface of a dielectric powder, such as an inorganic fine powder with a high dielectric constant, to make it hydrophilic, and then emulsifying it in water containing a surfactant. It is a highly concentrated, low to medium viscosity, paste-like emulsion-type paint obtained by uniformly mixing it in a vehicle for use.

As the paint vehicle, a resin component such as a thermosetting alkyd resin dissolved in an organic solvent can be used.

Further, as the dielectric powder, titanium oxide, barium titanate, lead zirconate, etc. can be used.

The amount of dielectric powder in the dielectric paste is preferably 50
~80 weight 96. In addition, the amount of resin component in the dielectric paste is 10 to 25% by weight, and the amount of organic solvent and water is 1% by weight.
0 to 25 weight 96 is preferable.

Dielectric paste is a highly viscous, stringy liquid with a viscosity of 70,000 to 120,000 cps when statically stable at room temperature. Further, the dielectric paste has a large thixotropic property, and its viscosity changes greatly by stirring (or shaking).

For example, if a dielectric paste of 100,000 cps is strongly stirred when it is stable, the speed may be reduced by half to 50,000 cps.

Since the dielectric paste used in the present invention is an emulsion-type water-based paint, even if the amount of dielectric powder is almost the same as that of an organic solvent-based paint, the viscosity at room temperature is 8.000~2.
0,000, and the viscosity change due to stirring or temperature change is also small. This low viscosity is much superior to organic solvent-based paints in terms of stationary defoaming properties, and especially when centrifugal separation is employed as in the method of the present invention, organic solvent-based paints are not defoamed. However, it is possible to defoam sufficiently for practical purposes.

The first and second electrodes can be obtained by patterning (etching) a copper sheet or a stainless steel sheet into a predetermined pattern.

[Function] In the method of the present invention, a dielectric paste is first applied to the first electrode sheet. This dielectric paste is an emulsion-type paint in which dielectric powder is dispersed in a paint vehicle, so even if it contains a high concentration of dielectric powder, the viscosity does not increase very much. can be easily defoamed by centrifugal rotation. As a result, it is possible to obtain a dielectric layer of uniform thickness.

In addition, because the dielectric powder gathers at the bottom (first electrode side) and the vehicle at the top due to centrifugal rotation, slight irregularities on the top surface of the dielectric layer do not affect the dot concentration, and therefore, the ion generation method of the present invention Using the apparatus, it is possible to form a dot latent image with high precision.

[Example] Hereinafter, with reference to the drawings, specific examples of the present invention will be described.
explain.

FIG. 1 is a sectional view of an ion generator according to an embodiment of the present invention, and FIG. 2 is a perspective view thereof.

In FIG. 1, a plurality of first electrodes 1 extend in parallel to a direction perpendicular to the paper surface, and a plurality of second electrodes 3 extend in a direction different from the first electrodes. A dielectric layer 2 is sandwiched between these first and second electrodes. The second electrode 3 has an opening corresponding to the first electrode 1. A third electrode 5 is arranged on the opposite side of the second electrode 3 from the first electrode 1, and this third electrode 5 has an opening corresponding to the opening of the second electrode 3. Second electrode 3 and third electrode 5
An insulator layer 4 is sandwiched between the insulator layer 4 and
has openings corresponding to the openings of the second electrode 3 and the third electrode 5.

In the ion generator configured as described above, by selectively applying a voltage between the plurality of first electrodes 1 and the second electrodes 3, the second electrode corresponding to the selected portion is Positive and negative ions are generated near the opening of No.3. Second
A bias voltage is applied between the electrode 3 and the third electrode 5, and only ions determined by the polarity are extracted from the generated ions. The extracted ions pass through the insulator layer 4 and the opening of the third electrode 5, and selectively charge a member to be charged (not shown) disposed opposite the third electrode. In this way, by selectively driving the plurality of first electrodes 1 and second electrodes 3, a dot latent image is formed on the charged member.

That is, this ion generator functions as an electrostatic recording head.

Example 1 36% phthalic anhydride, 4896 soybean oil (medium oil), and 16% glycerin were mixed in a reaction vessel, and after purging with nitrogen,
A preliminary reaction was carried out at 0° C. for 3 hours to obtain an alkyd resin.

To 100 parts of the solid content of this alkyd resin, 30 parts of benzyl alcohol and carpitol acetate (CH, Coo)
(C2H40・C2H40” C2Hs ) ) 2
0 parts, and while stirring, add 200 parts of titanium oxide powder, 5 parts of surfactant (nonionic such as polyethylene glycol alkyl ether), and further add 100 parts of ion-exchanged water. It was dispersed into This was placed in a reaction vessel equipped with a reflux device and concentrated at 110° C. until the amount of volatile solvent and water became 15% to obtain a dielectric paste.

The dielectric paste thus obtained was applied to a thickness of 20 to 40 μm on a 5 μm thick copper sheet for the first electrode, and then centrifuged for 10 minutes before the coating began to dry. A dielectric layer of uniform thickness was formed by degassing. The rotation speed of the centrifuge is 5000 rpm (-100
0G).

Next, after heating and drying the dielectric layer, a second layer is placed on the dielectric layer.
A copper sheet with a thickness of 5 μm for the second electrode is stacked, and a heat press is applied from above to fix the copper sheet for the second electrode on the dielectric layer, and the dielectric layer is hardened by the heat of the heat press. I let it happen.

Next, the copper sheets for the first and second electrodes were patterned by etching either simultaneously or one by one to obtain an ion generator functioning as an electrostatic recording head.

When this ion generator was attached to an ionographic printer and an image was printed, a highly accurate printed image was obtained.

Example 2 100 parts of Kotax WE804 (trade name, manufactured by Toshisha), which is known as a water-soluble anionic acrylic resin, 60 parts of aromatic hydroxy ether, and 1 part of ion-exchanged water were added.
00 parts and 2 parts of triethylamine were added, and the titanium oxide powder 2
00 parts were added little by little and mixed. Heat to 100℃,
The water content was concentrated to 15% to obtain a dielectric paste.

Note that uniform dispersion can be facilitated by soaking the titanium oxide powder in a dilute solution of acrylic oligomer or a surfactant to treat the surface of the titanium oxide powder particles before mixing.

Thereafter, in the same manner as in Example 1, a dielectric paste was applied to a thickness of 20 to 40 μm on a 5 μm thick copper sheet for the first electrode.
Before the coating film began to dry, it was degassed by centrifugation for 10 minutes to form a dielectric layer of uniform thickness.

After drying the dielectric layer, the dielectric surface is moistened with a 1 part mixture of carpitol acetate and ethyl propionate, a 5 μm thick copper sheet for the second electrode is placed on top of this, and pressure is applied evenly to keep it static. I placed it.

One hour after pressurization, the pressure was released, and the dielectric layer was cured by heating to 150°C. Note that it is also possible to use a pressurizing material that can withstand 150° C. and perform heat curing while being pressurized.

Next, in the same manner as in Example 1, the copper sheets for the first and second electrodes were patterned by etching simultaneously or one by one to obtain an ion generator functioning as an electrostatic recording head.

When this ion generator was attached to an ionographic printer and an image was printed, a highly accurate printed image was obtained as in Example 1.

[Effects of the Invention] As explained above, in the present invention, since an emulsion-type paint in which dielectric powder is dispersed, that is, a dielectric paste, is used to form the dielectric layer, degassing is greatly improved by centrifugal rotation. This can be easily carried out, and as a result, it is possible to form a dielectric layer of uniform thickness and homogeneity. In addition, since centrifugal rotation is used, the dielectric powder is placed at the bottom (first electrode side).
Since the vehicle gathers at the top, slight irregularities on the top surface of the dielectric layer do not affect the dot density, making it possible to manufacture a recording head capable of forming a highly accurate dot latent image.

Furthermore, since the second electrode is laminated on the surface with a high vehicle concentration, strong adhesion is possible without using an adhesive, and processing is extremely simple. Furthermore, since the dielectric paste is water-based, the drying speed is slower than that of organic solvent-based paints, and there is no possibility that only the outer layer will harden first, inhibiting internal drying. As a result, a homogeneous dielectric layer is obtained.

As described above, according to the present invention, it is possible to form a dielectric layer that is substantially homogeneous and has a uniform thickness, thereby obtaining an ion generator for electrostatic recording that can form a dot latent image with high precision. Is possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an ion generator according to an embodiment of the present invention, and FIG. 2 is a perspective view thereof. DESCRIPTION OF SYMBOLS 1... First electrode, 2... Dielectric layer, 3... Second
4... Insulator layer, 5... Third electrode. Applicant's agent Patent attorney Jun Tsuboi Figure 21! I

Claims (3)

[Claims] (1) Step of applying an emulsion type dielectric paste in which dielectric powder is dispersed in a paint vehicle to one side of the first electrode sheet, and centrifuging the first electrode sheet coated with the dielectric paste. Rotating process, a second layer on top of the coating layer
an ion flow electrostatic method comprising the steps of: placing and press-bonding the first and second electrode sheets; and patterning the first and second electrode sheets into a predetermined pattern to form first and second electrodes. A method for manufacturing a recording ion generator. (2) After drying the applied layer after the centrifugal rotation, the surface of the applied layer is activated by treating the surface of the applied layer with a solvent or by heating the applied layer surface after the centrifugal rotation. The method for manufacturing an ion generator for ion flow electrostatic recording according to claim 1. (3) An ion generator for ion flow electrostatic recording comprising a dielectric layer having dielectric powder dispersed therebetween between a first electrode and a second electrode, wherein An ion generator for ion flow electrostatic recording, characterized in that the dielectric powder has a high concentration on the first electrode side and a low concentration on the second electrode side.