JPH0355285A - Image forming device - Google Patents

Abstract

PURPOSE:To lower the replacement frequency of electrodes and to simplify the handling by constituting one of a pair of electrodes of such a structure that two or more releasable conductive layers are laminated. CONSTITUTION:At least one of a pair of electrodes 1, 3 has constitution such that two or more releasable conductive layers are laminated. Therefore, when the outer surface of the uppermost layer constituting the surface of the electrode 1 having a multilayer structure consisting of the releasable conductive layers is deteriorated, said layer is released to expose the conductive layer thereunder and a new electrode surface is formed to make it possible to continuously utilize said electrode. By this constitution, electrode function can be easily returned without replacing the whole of the electrode 1 by simple operation and multilayer printing can be performed stably and simply.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for forming an image using a recording material (ink) whose adhesion changes depending on the polarity of an applied voltage.

[Conventional Techniques WI] Lithographic printing, letterpress printing, and gravure printing are used in printing technology, but they require complicated processes to create plates and require the use of dampening water to butter the ink. It was extremely troublesome to handle. Furthermore, the adhesion of the ink was easily affected by temperature and humidity, and it lacked environmental stability. For this reason, there are many difficulties in applying conventional printing techniques to recording peripheral devices such as computers.

On the other hand, printers using various recording methods are known as recording peripheral devices for computers, such as laser beam printers, inkjet printers, thermal transfer printers, wire dot printers, and daisy foil printers. However, the high volume printing achieved with the above-mentioned printing technology had problems such as cost.

To solve the problems with these printers, for example, Japanese Patent Application Laid-open Nos. 63-30279 and 63-7
No. 1359, No. 63-71360, and No. 63
2. Description of the Related Art A printer using ink whose adhesive properties change depending on the polarity of an applied voltage is known, as disclosed in Japanese Patent No. 71386 and the like.

(Problem to be Solved by the Invention) A printer that uses ink whose adhesion changes depending on the polarity of the applied voltage has a pair of electrodes for applying voltage to the ink, and one of the electrodes has a According to the polarity pattern, ink is not attached to one electrode, but ink is attached in a pattern to the other electrode, and the ink is transferred to a transfer medium such as paper to form an image. It has a structure for carrying out.

Electrodes for such printers are usually made of copper, nickel, stainless steel, aluminum, zinc, chromium, gold, or the like. However, electrodes made of these materials often experience surface deterioration over long-term use, impairing their function as electric buckets, and require relatively frequent replacement of the electrodes.

Furthermore, the deterioration of the electrode surface was more pronounced on the anode side.

An object of the present invention is to provide an image forming apparatus that uses ink whose adhesion changes depending on the polarity of an applied voltage, which requires less frequent electrode replacement, is easy to handle, and does not require complicated maintenance. There is a particular thing.

[Means to solve the problem]

The image forming apparatus of the present invention includes: a pair of electrodes capable of forming on one electrode a polarity pattern of an applied voltage that changes the adhesion of a recording material; and means for supplying a recording material between these electrodes;
and means for transferring a patterned recording material that does not adhere to one of a pair of electrodes but adheres to the other electrode to a transfer medium in accordance with a polarity pattern of an applied voltage. At least one of the electrodes has a structure in which two or more peelable conductive layers are laminated.

When the outer surface of the uppermost layer constituting the electrode deteriorates, the image forming apparatus of the present invention has a multilayer structure consisting of a removable conductive layer. By exposing the conductive layer of the electrode and forming a new electrode surface, it can continue to be used as an electrode, eliminating the need for frequent replacement of the entire electrode.

At that time, when the top layer was peeled off, the ink that adhered to the top layer (
Since the recording material (recording material) is removed from the electrodes at the same time, the effect of cleaning the electrodes can be obtained at the same time.

Furthermore, if the conductive layer is formed from a conductive porous sheet, the sheet can be peeled off with the ink soaked into the sheet, and the peeled sheet can be handled very easily.

〔Example〕

Embodiments of the image forming apparatus of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a side view showing essential parts of an embodiment of an image forming apparatus of the present invention.

The ink carrying roll 1 is a member that has a cylindrical shape and rotates in eight directions indicated by arrows. The roll 1 is made of a conductive material such as aluminum, copper, or stainless steel. Ink 2, which is a recording material, is formed on the surface (on the cylindrical surface) of the ink carrying roll 1 to a uniform thickness by a coating roll 9 rotating in the direction of arrow E.

The ink carrying roll 1 is connected to one end of a DC power supply 103, and forms an anode of a pair of electrodes forming the facing plate roll 3. As this ink carrying roll 1,
As shown in FIG. 2, a structure in which conductive layers are stacked in multiple layers in a peelable manner is used. Specifically, as shown in Figure 2, metal sheets, sheets with conductive fillers such as carbon and metal powder divided into polymers and ceramics, or resin fibers such as polyethylene fibers and polypropylene ya fibers with copper, Conductive materials such as those in which metal powder such as nickel is dispersed, carbon fiber (carbon paper), conductive filler in L resin, and made porous by foaming, sintering, swelling, etc. Each conductive layer (1-a) is formed by wrapping a porous sheet or the like around the outer periphery of a cylindrical base (mandrel, l-j) one layer at a time using an adhesive such as vinyl acetate, neoprene, EVA, epoxy, acrylic, or carboxymethylcellulose. ~1-h) can be used.

The conductivity of the sheet forming each conductive layer is σ = 10-8Ω
-1 or more is preferable.

The number of conductive layers ranges from 10 to 1.0 depending on the durability of conductivity.
000 layers, more preferably about 50 to 700 layers. The layer thickness is preferably about 10-2 mm.

When the conductive layer is formed from a porous sheet, the above-mentioned effects can be further obtained.

In addition, from the viewpoint of mechanical strength, the base body (1-j) may be a cylindrical body made of metal such as stainless steel copper, aluminum, or copper, or polyamide, polyethylene, polyacetal,
A resin molded body made of plastic such as polycarbonate or the like is used.

A plate 4 wound around a plate roll 3 is in contact with ink 2 on the surface of the ink carrying roll 1. The plate roll 3 is rotating in the direction of arrow B in the opposite direction to the roll 1. In the plate 4, as shown in FIG. 3, for example, a desired pattern 4b made of an insulating material is provided on a base material 4a made of a conductive material such as metal.

As the material for the material 4a, aluminum, copper, stainless steel, platinum, gold, chromium, nickel, steel copper, carbon, etc., or conductive polymers or various polymers in which metal fillers are dispersed can be used. As the material for the pattern 4b, thermal transfer recording materials (mainly wax and resin), electrophotographic toners, vinyl polymers, and natural or synthetic polymers can be used. In this way, by turning on the switch 11 and applying voltage from the power source 103 between the plate 4 and the ink carrying roll 1, the adhesion of the ink 2 that comes into contact with the conductive portion of the plate 4 changes, and due to the difference in adhesion, Ink 2 is deposited in a pattern on the plate to form an ink image. The voltage of the power supply 103 is practically 3 to 1. O
A DC voltage of OV, more preferably 5 to 80V is preferable, and the image quality can be made even sharper by further applying a high frequency (10 Hz - 100 kHz) AC bias voltage.

In FIG. 1, when electricity is repeatedly applied between the ink-carrying roll 1 and the plate 4, carbon and conductive filler gradually separate from the surface layer of the ink-carrying roll 1, causing the ink to lose its conductivity. It becomes impossible to change the adhesion of 2. Therefore, the conductivity R of the surface layer (1-a)
By peeling off the electrode and exposing the surface of the new conductive layer (1-b), it is possible to continue to control the adhesion of ink 2 without replacing the entire electrode, and it is possible to stably print a large amount. can.

In FIG. 1, the plate 4 side is the cathode and the ink carrying roll 1 side is the anode, but the reverse may be used depending on the ink.

Note that N.C. has a multilayer structure of conductive layers. Although it is usually effective to use the anode, which has a more pronounced surface deterioration, it may be used as both the cathode and the anode.

Specifically, the voltage from the power source 103 is preferably applied between the respective rotation axes of the printing roll 3 and the ink carrying roll 1.

The thickness of the ink layer 2 formed on the surface of the ink carrying roll 1 is determined by (the size of the gap between the ink carrying roll 1 and the coating roll 9, the fluidity or viscosity of the ink 2, and the thickness of the surface of the ink carrying roll 1). Although it varies depending on the material, surface roughness, rotational speed of the roll 1, etc.), at the ink transfer position where the roll 1 faces the pattern 4 on the printing roll 3, it is approximately 0.001 to iooml! It is preferably about 1.

The layer thickness of this ink layer 2 is O. If OO is less than 1 mm, it will be difficult to form a uniform ink layer on the ink carrying roll 1. On the other hand, if the ink layer thickness exceeds 100 mm, it becomes difficult to convey the ink layer 2 while keeping the surface layer of the ink layer (the layer in contact with the conductive pattern plate roll 4) at a uniform circumferential speed, and It is also difficult to energize the support roll 1 and the plate 4.

Next, the ink image on the plate 4 is transferred to the plan cylinder 5, which rotates in the direction of arrow C while being in pressure contact with the plate 4, and the ink image on the plan cylinder 5 is further rotated in the direction of arrow D, while being in pressure contact with the plan cylinder 5. The ink image . An image 8 corresponding to the image 8 is formed.

In some cases, the ink image on the plate 4 may be directly transferred onto the transfer medium 7 without providing the blank cylinder 5, but for example, the blank cylinder 5 may be made of silicone rubber, fluorine rubber, nitrile rubber, butyl rubber, etc. By providing this, it is possible to prevent abrasion and deterioration of the plate due to the material of the blank cylinder 5, and also,
An image with the same pattern as the plate (bog image) can be obtained on the recording medium.

Embodiment 2 FIG. 4 shows another embodiment of the present invention. In the example shown in FIG. 4, a printed circuit board having a photoresist image on a metal plate is used as the plate 4, and 4c in the figure indicates an insulating photoresist. In this embodiment, ink adheres to parts of the metal substrate where there is no photoresist, and an image 8 is formed on the recording paper 7. In the case of ink that inherently has adhesive properties, the ink adheres to the photoresist portion to form an image.

Embodiment 3 FIG. 5 shows still another embodiment of the present invention. In this embodiment, a plate is used in which a photoconductor in which a continuous conductive portion 4d is formed by irradiating a light image onto the photoconductor is disposed on a substrate made of a conductive material. Such photoconductors include gelatin-silver halide, zinc oxide film,
Selenium, amorphous silicon, organic photoconductors, etc. are suitably used. The sustained conductivity of optical semiconductors is explained in detail in Chapter 2 of ``Electrophotography'' by Seventh Shaft.

In addition to the above, a plate having an insulating film on which an image-like conductive pattern is formed by discharge breakdown on a substrate made of a conductive material can also be used. Furthermore, it is also possible to use a plate having a photographic image on which a conductive pattern of a silver image is formed by depositing silver particles on a substrate made of a conductive material.

In the examples shown in FIGS. 1, 4, and 5, the plate 4 is used by being wound around a cylindrical plate roll 3, but the plate 4 is used as a flat plate and used as an electrode to apply ink to the plate. An ink image can also be formed on a plate by applying a voltage while applying the ink and sandwiching the ink between the plate and the counter electrode.

As explained above, the image forming apparatus of the present invention supplies a specific ink between an electrode (plate) having a desired insulation pattern and a counter electrode, and applies a voltage between the pair of electrodes. Image formation is performed by utilizing the fact that ink adhesion changes depending on the electrode pattern.

Therefore, the device of the present invention uses a type of ink that has adhesive properties when no voltage is applied, and loses its adhesive properties when a voltage is applied.

Inks used in these image forming methods will be described below.

Regarding the mechanism by which the ink changes from adhesive to non-adhesive due to voltage application, the following cases can be considered.

This is a case in which the ink is electrolyzed and gas is generated by energization due to voltage application, and the adhesion properties change.

In this case, the ink is adjusted so that it inherently has adhesive properties, and when a voltage is applied, the ink generates gas near one of the electrodes, and this gas prevents the ink from adhering to the electrode. In order for the ink to electrolyze and generate gas, the ink contains a solvent such as water, alcohol, or glycol, or a solvent in which an electrolyte such as sodium chloride or potassium chloride is dissolved. The lower the electrical resistance of the ink, the better, and the volume resistivity is preferably io5Ω·CII+ or less. When the volume resistance exceeds 10'Ω·cm, the current flow rate decreases, or a high voltage is required to prevent the current flow from decreasing.

Further, regarding the transfer of ink to the plate, almost the entire thickness direction of the portion of the ink layer to which the voltage is applied is transferred (hereinafter referred to as bulk transfer).

If the ink is a liquid such as water or alcohol, its cohesive force is weak and suitable adhesiveness cannot be obtained. This ink can be applied, for example, to a platinum-plated stainless steel plate held vertically.
Preferably, the thickness is such that when the ink is deposited to a thickness of 1.5 mm, the ink is substantially retained on the platinum-plated stainless steel plate.

In addition, when ink is sandwiched between two platinum-plated stainless steel plates and the thickness of the ink is set to 2, and the two platinum-plated stainless steel plates are separated from each other with no voltage applied, the ink does not appear on either plate. It is preferable that the two adhere to the same extent.

The viscosity of the ink is a shear rate of 10 rad/s. temperature 2
At 5°C, 10' to 10l0 boas, or even 104
~io8 Boaz is preferred.

Ink that uses the above-mentioned mechanism is basically composed of inorganic or organic fine particles and a liquid dispersion medium. The fine particles in the ink make it easier to cut the ink and improve the resolution of the image. Ink is a colloidal sol, an amorphous solid, and non-Newtonian in fluidity.

In order to change the adhesion of ink by applying voltage, fine particles are contained in the ink. A fine particle dispersion is formed by kneading in the above-mentioned liquid dispersion medium, for example, in a homogenizer, a colloid mill, or an ultrasonic disperser. Such particles include metals (Au, ^g,
Cu, etc.) particles, sulfides (zinc sulfide ZnS, antimony sulfide sb,s, , potassium sulfide K2S, calcium sulfide CaS, germanium sulfide GeS, cobalt sulfide GoS, tin sulfide SnS, iron sulfide FeS, copper sulfide Cu, S, sulfide Manganese MnS, Molybdenum sulfide Mo
2S = etc.) particles, silicic acid (orthosilicic acid H4Si04
, metasilicic acid 12SiO. ,,Mesoniciliic acid H2Si2
0, , mesotrisilicate H4Si303. Mesotetrasilicic acid H
, Si. 0, , etc.) particles, polyamide resin particles, polyamideimide resin particles, iron hydroxide particles, aluminum hydroxide particles, fluorinated mica particles, polyethylene particles, montmorillonite particles, fluorine resins, and the like. Further, polymer particles containing various charge control agents used as toners for electrophotography can also be used.

The above-mentioned fine particles have an average particle diameter of 100 μm or less,
Preferably, particles with a particle size of 0.1 um to 20 um, especially 10 μm or less, can be used, and such fine particles are contained in the ink in an amount of 1 coulometric part or more, preferably 3 parts by weight to 90 parts by weight, and more preferably 3 parts by weight to 90 parts by weight. Preferably, it can be contained in an amount of 5 parts to 60 parts by weight.

In addition, the liquid dispersion medium used in the ink includes ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (weight average molecular weight, about 100
N+000), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methyl rubitol, ethyl rubitol, butyl carbitol, ethyl rubitol acetate, diethyl rubitol, 1-lyethylene glycol monomethyl ether, triethylene Glycol monoethyl ether, brobylene glycol monomethyl ether, glycerin, triethanolamine, formamide, dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, 1.3
-dimethylimidazolidinone, N-methylacetamide, ethylene carbonate, acetamide, succinonitrile, dimethylsulfoxide, sulfolane, furfuryl alcohol, N,N-dimethylformamide, 2-ethoxyethanol, hexamethylphosphoric triamide (hexamethyl Phosphoric acid triamide>, 2-nitrobrobane, nitroethane, γ-butyrolactone, brobylene carbonate, 1,2,6-hexanetriol, dibrobylene glycol, hexylene glycol, etc. can be used alone or in combination of two media. Yes, the liquid dispersion medium can be used as an ink.
40 to 95 parts by weight, even 60 to 100 parts by weight
It is preferable to contain 85 parts by weight.

In a preferred embodiment, in order to control the viscosity of the ink, the above-described polymer soluble in the liquid dispersion medium is added to the ink material in an amount of 1 to 90 parts by weight, more preferably 1 to 90 parts by weight, based on 100 parts by weight of the ink material.
It can be contained in an amount of 50 parts by weight, particularly 1 to 20 parts by weight. Such polymers include guar gum, roasted bean gum, gum arabic, taragant,
Plant-based polymers such as carrageenan, vectin, mannan, and starch; Microbial polymers such as xanthan gum, dextrin, succinoglucan, and curdlan; Gelatin,
Animal-based polymers such as casein, albumin, and collagen; cellulose polymers such as methylcellulose, ethylcellulose, and hydroxyethylcellulose; or starch polymers such as soluble starch, carboxymethyl starch, and methyl starch; and alginic acid polymers such as propylene glycol alginate and alginate. , and other semi-solid polymers such as polysaccharide derivatives; vinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, and carboxyvinyl polymer polysodium acrylate; other polyethylene glycol, ethylene oxide, and brobylene oxide. Block copolymers, alkyd resins, phenolic resins, epoxy resins,
Polymers such as aminoalkyd resins, polyester resins, polyurethane resins, acrylic resins, polyamide resins, polyamideimide resins, polyesterimide resins, and silicone resins can be used alone or in combination of two or more. It is also possible to use greases such as silicone grease and liquid polymers such as polybdenum.

Since the change in ink adhesion is caused by the generation of gas due to electrolysis, water, methanol,
A solvent such as ethanol, glycerin, ethylene glycol, or propylene glycol, or a solvent in which an electrolyte such as potassium iodide or lithium borofluoride is dissolved is preferably used. The contents of the liquid dispersion medium and fine particles are the same as those described above. In particular, it is preferable to use water or a liquid containing water as the liquid dispersion medium because hydrogen gas is likely to be generated on the negative electrode side. When water and another liquid dispersion medium are mixed, the content of water is preferably 1 part by weight or more, more preferably 5 parts by weight or more, based on 100 parts by weight of the ink.

In the case of ink that generates gas through electrolysis, the fine particles contained in the ink include, in addition to those listed above, silica, fluorocarbon, titanium oxide, carbon black, fluorocarbon, and the like.

In a preferred embodiment of the ink, considering the viscoelastic properties of the ink, it is preferable to use swellable fine particles capable of retaining the above-mentioned liquid dispersion medium as all or part of the fine particles in the ink. Such swellable particles include, for example, N
a-montmorillonite, Ca-montmorillonite, 3-
Octahedral synthetic smectite, Na-hectolite, Li-
Examples include fluorinated micas such as hectorite, Na-teniolite, Na-tetrasilicic mica, and Li-teniolite, synthetic mica, and silica. The above-mentioned fluorinated mica can be represented by the following general formula (1).

General formula (1> W4-t/* (X. Y) 2.11-3 (
240 r. ) In the F2 formula, W is Na or Li, X and Y are y g 3 +Fe", Ni", Mn", A
l", Fe". 6-coordinate ion such as Li+, Z is A
It represents a cation with a coordination number of 4, such as I'', St'', Ge', Fe3◆, B3◆, or a combination thereof (AI''/Si'').

The average particle diameter of the swellable fine particles is preferably 75 μm or less, more preferably 0.8 to 15 μm, and preferably 8 μm or less in a dry state.

The ink may contain colorants such as carbon black and other dyes and pigments that are generally used in the fields of printing and recording, if necessary. When the ink contains a colorant, the content of the colorant is 0 per 100 parts by weight of the ink.
．． 1 to 40 parts by weight, more preferably 1 to 20 parts by weight.

Further, instead of or together with the coloring material, a coloring compound that develops color upon application of voltage may be contained. In addition, the ink may contain an electrolyte, thickener, thinner, surfactant, etc. that impart conductivity.

Furthermore, it is also possible for the above-mentioned fine particles themselves to also function as a coloring material.

To obtain such an ink, for example, a liquid dispersion medium and fine particles may be mixed by a conventional method.

In each of the above-mentioned embodiments (in which the cylindrical ink transfer roller 1 is used as the ink transfer means, an example in which a cylindrical ink transfer roller 1 is used as the ink transfer means) may also be used. This belt or sheet-like ink transport member may be fed out from one side and wound up from the other, but it is preferable to use it repeatedly by making it move endlessly.

〔Effect of the invention〕

In the image forming device of the present invention, a structure made of a large number of laminated conductive layers that can be peeled off is used as the electrode used to attach the recording material to the plate in a pattern, and even if the surface deteriorates, By simply peeling off the top layer, the electrode function can be easily restored without replacing the entire electrode.

Therefore, according to the present invention, the image forming apparatus is easy to maintain and can stably and easily perform large-volume printing as a recording peripheral device such as a printer for a computer, and does not require frequent replacement of electrodes. can be provided.

[Brief explanation of drawings]

FIG. 1 is a side view showing an example of the image type detection device of the present invention, FIG. 2 is a partially enlarged side view of an electrode having a multi-counterfeit conductive layer, and FIG.
The figure is a perspective view showing an example of a plate used in the apparatus of the invention, and FIGS. 4 and 5 are side views showing other examples of the image forming apparatus of the invention. DESCRIPTION OF SYMBOLS 1.-ink carrying roll, 2.. ink, 3.. plate roll, 4.. plate, 5.. plan cylinder, 6.. impression cylinder, 7.. transferred object, 8. ...Ink image, 9...Coating roll, 10...Ink reservoir.

Claims (1)

[Scope of Claims] 1) A pair of electrodes capable of forming on one electrode a pattern of polarity of applied voltage that changes the adhesion of a recording material, and means for supplying a recording material between these electrodes; In an image forming apparatus, at least one of the pair of electrodes is configured to transfer a patterned recording material that is not attached to one of the pair of electrodes and is attached to the other electrode to a transfer medium in accordance with the polar pattern; An image forming apparatus, one of which has a structure in which two or more removable conductive layers are laminated. 2) The image forming apparatus according to claim 1, wherein the conductive layer is a polymer sheet, a ceramic sheet, or a metal sheet in which a conductive filler is dispersed. 3) The image forming apparatus according to claim 1 or 2, wherein the conductive layer is a conductive porous sheet. 4) The image forming apparatus according to claim 1, wherein one of the pair of electrodes is an anode, and at least the anode has a structure in which two or more removable conductive layers are laminated.