JPH0355244A - Method and apparatus for forming of image - Google Patents

Abstract

PURPOSE:To form an image having excellent environmental stability by removing water immersed with ink before and/or simultaneously upon application of a voltage. CONSTITUTION:Water contained in ink is removed before and/or simultaneously upon application of a voltage. That is, water content of ink is measured by the resistance value or current value of a fourth DC power source, and ink in an ink reservoir 103 and an ink layer 108 is evaporated by drying means 131, 132. Blowing of hot blast, heating of an infrared ray, etc., may be used as the first, second means 131, 132, or drying by forcible idle rotation, a blower, etc., may be utilized as drying. Thus, practical desire such as costs of operability, environmental stability, large quantity printing is satisfied, and a satisfactory image can be particularly stably obtained under an environment of high humidity.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an image forming method using an ink whose adhesion to at least one electrode surface is reduced by voltage application, and an image forming apparatus for carrying out the method. [Conventional technology] Lithographic printing, letterpress printing, gravure printing, etc. are used in printing technology, but they require complicated processes to create plates and require 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, there was a problem in that the above-mentioned printing technology was not suitable for high-volume printing in terms of cost and the like. [Problems to be Solved by the Invention] The present invention provides a recording material whose adhesion changes with the application of voltage in order to satisfy the above-mentioned practical demands such as ease of handling, environmental stability, cost 1 in high-volume printing, etc. It is an object of the present invention to provide an image forming method and an image forming apparatus which are based on the use of a method and which have particularly excellent environmental stability. [Means for Solving the Problems 1] The present invention is a step of sandwiching adhesive ink whose adhesion to the surface of at least one electrode is reduced by applying a voltage between a pair of electrodes, and applying a voltage imagewise to transfer the adhesive ink. an image forming method comprising a step of removing water contained in the ink before and/or simultaneously with the application of the voltage; an image forming apparatus capable of carrying out the method; and a pair of electrodes. An image forming method comprising the steps of sandwiching an adhesive ink whose adhesion to at least one electrode surface is reduced by applying a voltage between the two electrodes, applying a voltage in an imagewise manner, and transferring the ink. The present invention provides an image forming method including a step of measuring electrical conductivity, and an image forming apparatus capable of carrying out the method.

Effect 1 The ink used in the image forming method of the present invention is an ink whose adhesion to at least one electrode surface is reduced by voltage application. When the ink used in the present invention is sandwiched between electrodes consisting of an anode and a cathode and a voltage is applied and current is applied, non-adhesion occurs to either the anode or the anode electrode. The reason for this selective non-adhesion is that electricity causes electrolysis in the vicinity of the electrodes, generating gases such as hydrogen gas and oxygen gas, and whichever of the positive and negative electrodes generates a larger amount of gas becomes non-adherent. It is considered a thing. As described above, the ink used in the present invention is selectively non-adherent to either the positive or negative electrodes, and as a result, almost the entire part of the ink layer in the thickness direction moves ( (hereinafter referred to as bulk movement). As an example, gas generation due to electrolysis of a ○H group-containing solvent by energization, and gas generation due to electrolysis of water by energization are shown below. At the cathode, 2ROH" +2e → H2 ↑+2RO- (1 mole of hydrogen gas is generated) - In the case of water, 2H" +2e -h }{, ↑ (1 mole of hydrogen gas is generated) At the anode, 2ROH - 2RCHO+2H" +2e
In the case of water, 20H- = Ha o + station 02 + 2e (oxygen station molar generation) As shown in the above formula, the amount of gas generated is proportional to the electron ml (e-), that is, the current value, and only the cathode (containing ○H groups other than water) Gas is generated in the solvent), or twice as much gas is generated only at the cathode as at the anode. In other words, if there is a difference in the amount of gas generated above a certain amount, the ink at one pole (the cathode in the case of the above formula) becomes non-adhesive. Use of such ink enables image formation that is relatively easy to handle and requires little maintenance. Furthermore, the water content of the ink can be detected by measuring the electrical resistance and/or electrical conductivity of the ink. Furthermore, the applied voltage is changed in response to changes in the electrical resistance of the ink. In other words, the voltage is automatically or manually increased by the increase in the electrical resistance of the ink in order to ensure the current value necessary for bulk transfer. You can also do it. Furthermore, when the electrical resistance of the ink decreases due to moisture absorption, it becomes possible to automatically or manually lower the applied voltage. Furthermore, if the ink is not sufficiently coated and current leaks partially, detecting the leak enables automatic operations such as alarms and roll stoppages. Furthermore, when recording paper, dust, etc. are caught in a region where ink should originally be caught, it becomes possible to detect this by a change in electrical resistance, and automatic operations such as stopping voltage application become possible. By performing such a step, even better image formation can be stably performed. [Embodiment] Moisture removal in the method of the present invention can be carried out using a suitable drying means. As such a drying means, for example, a hot air dryer, an infrared heating dryer, etc. can be used. Further, for example, it is also possible to use, separately from the printing process, forced idle rotation of the roll for a certain period of time to ensure sufficient drying, or a means for performing the idle rotation. Alternatively, for example, a blower may be used which is provided with special blades on or around the roll and blows air onto the ink constantly or at desired times as the roll rotates. Further, as a method for detecting the electrical resistance of ink, there are, for example, a method and a means of measuring a current value by applying a voltage to a pair of electrodes with the ink sandwiched between them. By operating the drying means while detecting the amount of moisture in the ink, more precise moisture control becomes possible. Normally, when the water content of ink increases, the electrical resistance decreases (electrical conductivity increases), so it is preferable to use changes in this property as a detection means. The image forming apparatus of the present invention may be any apparatus as long as it has means capable of performing the above method. Such a device is
For example, at least one pair of electrodes having a shape capable of applying a voltage imagewise, a power source for applying a voltage between the electrodes, a means for supplying ink between the electrodes, and a method according to changes in the adhesion of the ink. The apparatus includes means for selectively transferring the ink. It is preferable that the electrode and the supply transfer means are installed on a roller-shaped member or a roller-shaped part. Moreover, the same member may serve as two or more means. The present invention will be described below with reference to the drawings. The image forming apparatus used in the image forming method of the present invention has at least one pair of electrodes. In the image forming apparatus shown in FIG. 1, an ink carrying roll 101 and a first intermediate roll 105
, or the first intermediate roll 105 and the second intermediate roll 10
7. The plan roll 111 and the cleaning roll 115 and the plate roll 109 and the second intermediate roll 107 are each a pair of electrodes. Now, in the image forming apparatus shown in FIG. 1, the ink carrying roll! 01 is a member that has a cylindrical shape and rotates in the eight directions indicated by the arrows. The roll lot is preferably formed of a conductive material such as aluminum, copper 5 stainless steel, or the like. On the surface (cylindrical surface) of the ink carrying roll 101, the ink 2, which is a recording material, is formed to have a uniform thickness by the coating roll 104 rotating in the direction of arrow B. This roll 101
The material constituting the surface which is the ink carrying surface of is particularly suitable as long as it is a material that can form a desired layer of ink 2 on the surface (by conveying the ink 2 by rotation in the eight directions of the arrow). It can be used without restrictions. More specifically, a conductor made of metal such as stainless steel is preferred. The surface of an ink carrying roll lot made of such a material may be a smooth surface, but from the point of view of further improving the conveying and carrying properties of the ink 2, it may be appropriately roughened (for example, according to JIS
It is preferable that the surface roughness of 80601 is approximately Is. Ink 2 is replenished into the ink reservoir 103. The ink 2 on the surface of the ink carrying roll 101 has the lth
Intermediate roll 105 is in contact. First intermediate opening 105
rotates in the direction of arrow C in the opposite direction to the roll 101 to form an ink layer 106 on its surface. The second intermediate roll 107 contacts the ink layer 106 and rotates in the direction of arrow D, forming an ink layer 108 on the surface of the second intermediate roll 107. The first intermediate roll 105, the second
The intermediate hole 107 is preferably made of a conductive material such as aluminum, copper, or stainless steel. Furthermore, the printing plate 110 on the plate roll 9 rotating in the direction of arrow E comes into contact with the ink layer 108, and the ink of the ink layer 108 is transferred to the image area of the printing plate +10, thereby forming an ink image. As the printing plate 110, a conventionally known one can be used. For example, a printing plate, a gravure printing plate, a letterpress, etc. can be used. Further, the printing plate 110 is composed of a conductive part and an insulating part, and for example, by applying a voltage from the fourth DC power supply 121 between the printing plate 110 and the second intermediate roll 107, ink does not adhere to the conductive part of the plate. , the ink may adhere only to the insulating portion. Further, the moisture content of the ink is measured from the resistance value or current value of the fourth DC power source, and the moisture in the ink in the ink reservoir 103 and the ink layer 108 is evaporated by drying means 131 and 132. First drying means l31. As the second drying means 132, hot air blowing, infrared heating, etc. can be used, and drying using forced air rotation, blower, etc. as exemplified above may also be used. Next, the ink image on the printing plate 110 is transferred to the conductive blanket 112 on the blank roll 111 rotating in the direction of arrow F while being in pressure contact with the printing plate 110, and the ink image on the blanket 112 is transferred to the conductive blanket 112 on the blanket 112. The ink image is transferred onto a recording medium 114 (paper, cloth, metal sheet, etc.) that passes in the J direction between pressure rolls 113 rotating in the direction of arrow G while being in pressure contact with each other, and the ink image corresponds to the above ink image on the recording medium 114. An image is formed. In some cases, the ink image on the plate 110 may be directly transferred onto the recording medium 114 without providing the blank roll Ill and the blanket 112, but if the blank roll 111 and the blanket 112 are provided, the material of the blanket 112 This makes it possible to prevent abrasion and deterioration of the plate, and to obtain an image with the same pattern as the plate on the recording medium. Now, if you do not remove the ink layer on the first intermediate roll 105, second intermediate roll 107, and blanket 112 after printing is finished, the ink layer will dry and interfere with the next printing. The first intermediate roll 5, the second
The intermediate roll 6 and blanket 112 are cleaned. First, the contact between the printing roll 109 and the second intermediate roll 107 is removed, and the contact between the first intermediate roll 105 and the second intermediate roll 107 is removed.
By applying a voltage between them so that the ink on the second intermediate roll 107 side becomes non-adhesive and rotating both rolls 107 and 105, the ink on the second intermediate roll +07 is transferred to the first intermediate roll. 105. That is, by utilizing the fact that the adhesion of ink is reduced on one electrode side by voltage application, ink remaining in the image forming apparatus can be moved one after another to perform ink cleaning. Next, the contact between the first intermediate roll 105 and the second intermediate roll 107 is removed, so that the first intermediate roll 105 side becomes non-adherent with ink between the first intermediate roll 105 and the ink carrying roll 101. By applying a voltage to the ink carrier roll 1, the ink layer 106 on the first intermediate roll 105 is
Absorbed by ink 2 above 01. In the above description, ink was removed by providing power supplies between the first intermediate roll 105 and the second intermediate roll 107 and between the first intermediate roll 105 and the ink carrying roll 101, respectively. A power source is provided between the second intermediate roll 107 and the ink carrying roll lot, and the second intermediate roll 107
The ink above and the ink above the first intermediate hole 105 may be removed successively. Further, another cleaning roll may be brought into contact with the first intermediate roll 105 or the second intermediate roll 107, and ink may be collected on this roll by applying a voltage. On the other hand, cleaning of the blanket 112 is similarly performed by applying voltage. That is, first, the blanket 112
is separated from the printing plate 110 and pressure roll 113. Print version 1
10 is usually removed after printing is completed in order to replace it with another printing plate. Next, the coating roll 116 for cleaning roll
The cleaning ink layer 117 formed on the cleaning roll 115 is brought into contact with the blanket 112 on the blank roll 111, and the blank roll 111 is moved in the F direction, the cleaning roll 115 in the H direction, and the cleaning coating roll 116 is moved in the machine direction. Rotate it to
Further, the residual ink on the blank roll 111 is removed by applying a voltage between the blank roll 111 and the cleaning roll 115 so that the cleaning roll 115 side becomes adhesive and the blank roll 111 side becomes non-adhesive. A cleaning J is placed on the cleaning roll 115 in advance.
iill7 is formed on the blanket 112
Since ink is formed in a pattern on the surface, if the cleaning layer 117 is not provided, there will be many areas where the cleaning roll 115 and the blanket 112 will come into direct contact without an ink layer intervening, resulting in severe wear. It's for this reason. Cleaning roll 115 and blanket 1
Depending on the material of the cleaning roll 115, the cleaning layer 117 may not be provided on the cleaning roll 115 in advance. The aforementioned voltage is applied to a first DC power supply 118 using the ink carrying roll 101 and the first intermediate roll 105 as electrodes, a second DC power supply 119 using the first intermediate roll and the second intermediate roll 107 as electrodes, and a plan roll l. ．． 1 1 and the cleaning roll 115 as electrodes. The voltage of each power supply is practically 3~IOO
V, more preferably a DC voltage of 5 to 80V. The voltage is
Specifically, it is best to apply it between the rotation axes of each roll. Further, although in FIG. 1 the adhesion of ink on the cathode side is reduced, depending on the ink, the adhesion of ink on the anode side may be reduced. The above-described plate roll 109, blank roll 111, and cleaning roll 115 are made of a conductive material such as aluminum, copper, or stainless steel. Also, blanket 11
2 is preferably made of a conductive and elastic material, such as conductive rubber. Moreover, the rolls 101, 105, 107. 1
The surfaces of Nos. 11 and 115 may be smooth, but from the viewpoint of further improving the conveying and supporting properties of the amorphous ink, they should be appropriately roughened (for example, the surface roughness of JISO601 is about IS).
It is preferable that The thickness of the ink layer 2 formed on the surface of the ink carrying roll 101 is determined by (the size of the gap between the ink carrying roll lot and the coating roll 104 rotated by arrow B, the viscosity of the ink, and the thickness of the ink carrying roll 101 surface). This roll 101 is the first intermediate roll 105 (depending on the material, surface roughness, rotational speed of the roll, etc.)
At a position opposite to about 0. OQ about 1-10mm, even 0. 001 to 1 mm is preferable. The film thickness of this ink layer 2 is 0. If it is less than 0.001 mm, it will be difficult to form a uniform ink layer 2 on the ink carrying roll 101. On the other hand, if the ink layer thickness exceeds 10 mm, it becomes difficult to convey the ink while keeping the surface layer of the ink layer 2 at a uniform circumferential speed. If the ink 2 contains water (water-soluble ink, emulsion ink), it can be used in the image forming method of the present invention by changing from adhesive to non-adhesive by applying a voltage. The mechanism by which the ink changes from adhesive to non-adhesive due to voltage application is thought to be that the ink electrolyzes and generates gas when energized by voltage application, changing the adhesive property. In this case, the ink generates gas near the electrode due to the voltage application, and this gas prevents the ink from adhering to the electrode.
In order for the ink to electrolyze and generate gas, water, alcohol, etc. are added to the ink. Solvents such as glycol,
Alternatively, it contains 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 10'Ω·cm or less. When the volume resistance exceeds 10 11Ω·cm, the amount of current flowing decreases, or a high voltage is required to prevent the amount of current flowing from decreasing. When the ink used in the present invention is a low-viscosity liquid such as water or alcohol, the cohesive force is weak and suitable adhesion cannot be obtained. The viscosity of the ink is 10 rad/s. ，
lOI to 10Io Boas at a temperature of 25°C, even 1
The ink used in the present invention is preferably 0' to 10" bores. For example, when the ink is applied to a platinum-plated stainless steel plate vertically erected to a thickness of 21111 Tl, the temperature is 25°C and the humidity is 60. It is preferable that the ink be substantially retained on the platinum-plated stainless steel plate in an environment of
nm, and when two platinum-plated stainless steel plates are separated from each other at a speed of 5 cm/sec with no voltage applied, it is preferable that ink adheres to the same extent to both plates. The ink used in the present invention includes, for example, inorganic or organic fine particles and oxygen that can generate gas by applying a voltage (current).
It is composed of a liquid dispersion medium containing an H group. The fine particles in the ink make it easier to cut the ink and improve the resolution of the image. The ink used in the present invention is amorphous and non-Newtonian in fluidity. The particles include metals (Au, Ag, Cu, etc.)
Particles, sulfides (zinc sulfide ZnS, antimony sulfide Sb
aSs, potassium sulfide K2S, calcium sulfide C a
S s germanium sulfide Gas, VC cobalt C
oS, tin sulfide SnS, iron sulfide FeS, sulfide fACL
laS-manganese sulfide MnS, molybdenum sulfide MO23
3 etc.) particles, silicic acid (orthosilicic acid LSiL, metasilicic acid}1tSiOs, mesonicic acid HzSf20s,
Mesotrisilicate H4si30s, mesotetrasilicic acid H6Sin
O+ + etc.) particles, polyamide resin particles, polyamideimide resin particles, iron hydroxide particles, aluminum hydroxide particles, fluoride mica particles, polyethylene particles, montmorillonite particles, fluororesin, silica, fluorocarbon, titanium oxide, carbon black etc. can be used. Furthermore, polymer particles containing various load 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 0.1 μm to 20 μm, especially o. Fine particles of i μm or more and 10 μm or less can be used, and such fine particles are contained in the ink in an amount of 1 part by weight or more, preferably 3 parts by weight to 90 parts by weight, more preferably 5 parts by weight to 60 parts by weight, based on 100 parts by weight of the ink. It can be contained in parts by weight. Examples of OH group-containing solvents include water, methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (weight average molecular weight, about 100 to 1000). Ethylene glyco・
- monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,
Methyl carbitol, ethyl carbitol, butyl carbitol, ethyl ruby acetate, diethyl carbitol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, glycerin, triethanolamine, flu Furyl alcohol, 2-ethoxyethanol, 1. 2. A single medium or a mixed medium of two or more of 6-hexanetriol, dibrobi-1/glycol, hexylene glycol, etc., or a mixed solvent with other solvents can be used. The liquid dispersion medium is 40 to 95 parts by weight, more preferably 60 to 95 parts by weight, per 100 parts by weight of the ink.
It is preferable to contain 85 parts by weight. In addition, in order to control the viscosity of the ink, 1 to 90 parts by weight, more preferably 1 to 50 parts by weight, particularly 1 to 20 parts by weight of the above-mentioned polymer soluble in the liquid dispersion medium is added to the ink based on 100 parts by weight of the ink material. It can be contained in a proportion of parts by weight. Such polymers include plant-based polymers such as guar gum, locust bean gum, gum arabic, taragant, carrageenan, vectin, mannan, and starch; microbial polymers such as xanthan gum, dextrin, succinoglucan, and curdlan; gelatin, casein, and albumin. , animal-based polymers such as collagen: cellulose-based polymers such as methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose; or starch-based polymers such as soluble starch, carboxymethyl starch, and methyl starch; alginic acid-based polymers such as brobylene glycol alginate and alginate; Other semi-synthetic polymers such as polyvinyl pyrrolidone derivatives; vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, carboxyvinyl polymers, sodium polyacrylate; other polyethylene glycol, ethylene oxide, brobylene oxide Combined polymers such as block copolymers, alkyd resins, phenolic resins, epoxy resins, amino alkyd resins, polyester resins, polyurethane resins, acrylic resins, polyamide resins, polyamideimide resins, polyesterimide resins, silicone resins, etc. alone or in combination More than one species can be used in combination. It is also possible to use greases such as silicone grease and liquid polymers such as polybutene. In addition to the above-mentioned OH group-containing solvent, a solvent in which an electrolyte such as sodium chloride or potassium chloride is dissolved is preferably used as a solvent whose adhesion properties change due to the generation of gas by electrolysis. However, it is particularly 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 and 99 parts by weight or less, based on 100 parts by weight of the ink. In a preferred embodiment of the ink, in view of the viscoelastic properties of the ink, it is preferable to use swellable fine particles capable of retaining the above-mentioned liquid dispersion medium in all or part of the fine particles. Such swellable fine particles include, for example, Na
-montmorillonite, Ca-montmorillonite, 3-
Octahedral synthetic smectite, Na-hectite, L
Examples include fluorinated micas such as i-hectolite, Na-teniolite, Na-tetrasilicic acid, and Li-teniolite, synthetic mica, and silica. The above-mentioned fluorinated mica can be represented by the following general formula (1). General formula (1) L-1/3 (X, Y)2.5-s (Z4010
1 F2 where W is Na or Ij. X and Y are M g
2°Fe”, Mn”, AI”, Fe”. “Li”
6-coordinate ions such as 2 is AI'', S+'', Ge'
°, Fe'°1331i or a combination thereof (Al
"/Si4-)" represents a cation with a coordination number of 4.The average particle diameter of the swellable fine particles is 0.1 to 20μ in the dry state.
m, even 0. 8-15 μm. Among them, 0.8~8μ
m is preferred. The content of the swellable fine particles may be the same as the content of the fine particles described above, but in addition, the content of the ink 100
It is preferably 8 parts by weight to 60 parts by weight. It is preferable that the swellable fine particles have an electric charge on their surface in order to lower the resistance of the ink. 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 coloring material, the content of the coloring material is 100% of the ink.
It is preferably 0.1 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 to make the above-mentioned fine particles themselves function as a coloring agent. Also, if necessary, use anti-mold agent,
It may also contain additives such as preservatives. To obtain the ink described above, for example, a liquid dispersion medium and fine particles may be mixed in a conventional manner. Even with the above ink, when the humidity of the atmosphere in which it is used becomes high, it becomes difficult to control adhesion due to moisture absorption, which may lead to deterioration of image quality. In other words, the viscosity decreases due to moisture absorption, the cohesive force of the ink decreases, and the ink splits (cuts in the ink).
This causes difficulty in bulk movement of ink, resulting in image deterioration. Note that since the amount of water and the electrical resistance value of the ink are in an inversely proportional relationship, the amount of water can be measured by measuring the electrical resistance value of the ink. [Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 1. Preparation of ink Glycerin 100 parts by weight Chton, average particle size 1 μm or less) Lithium borofluoride (LiBFJ 10 parts by weight, trade name: Cyanfne 78F) Hexaglycerin boriricinoleate 10 parts by weight (manufactured by Nikko Chemicals, trade name) Hexaglyn PR-15) Among the above formulations, first mix glycerin, lithium borofluoride, and cyan pigment with an autohomonicer, then mix the surfactant and colloidal hydrated silicate manually with a stirrer, and then mix with a roll mill. The ink was obtained by mixing. 2. Ink water supply amount and electrical resistance value Various amounts (parts by weight) for 100 parts by weight of the above ink
The volume resistivity of the sample was measured, and the results are shown in Figure 2. 3. Ink adhesion test An ink adhesion test was conducted on ink samples (1) to (5) in which the following amounts of E were added to 100 parts by weight of the above ink. The results of ink adhesion are shown when ink is sandwiched between two platinum plates measuring 1 cm x 1 am, approximately 100 μm thick, and the gap between the two platinum plates is widened while applying a DC voltage of 40 V. 4. Printing Next, image formation was performed using the printing machine shown in Figure 1.
As the ink carrying roll 101, a 30 mm diameter platinum-plated stainless steel cylindrical roll (surface roughness Is) was used, and as the first intermediate roll 105, a 30 mm diameter iron cylindrical roll whose surface was hard chrome plated was used. This ink carrying roll 101 E first intermediate roll 10
The above-mentioned ink is put into the ink reservoir 103 corresponding to the joint part of 5, and the ink carrying roll 1171 is rotated at a circumferential speed of 20 mm/
The coating roller 10 is a cylindrical roll made of surface Teflon rubber that rotates in the direction of arrow A with the sea.
4 and the coating roll 104
was rotated at a circumferential speed of 20 mm/sea to form an ink layer of about 0.2 mm on the ink carrying roll 101, and then the first
When the intermediate roll 105 was rotated in the direction of arrow C at a circumferential speed of 20 mm/sea, the ink on the surface of the ink layer was transferred onto the first intermediate roll 105 (thickness: 0.1 mm or less). Next, a second intermediate roll +07 made of a stainless steel cylindrical roll (diameter 30 mm) rotates at a circumferential speed of 20 mm/sec in the direction of arrow D in contact with the first intermediate roll 105.
A part of the ink on the first intermediate hole 105 was transferred to form a thin layer of ink (ink thickness of 0.1 mm or less). The surface of the second intermediate roll 107 is provided with conductive silicone rubber containing carbon powder. Next, a desired polymer image made of vinyl resin (T gas insulator) was formed on the surface of the copper plate. This is wound around the plate roll 109 as the printing plate 110, and a DC voltage of 25 V is applied between the plate roll 109 and the second intermediate roll 107 by the fourth DC power supply 121, with the plate roll 109 as the negative pole and the second intermediate roll 107 as the brass pole. When the roller was rotated in the direction of arrow E while being in contact with the ink on the second intermediate roll 107 while applying voltage, the ink was transferred only onto the polymer image, and furthermore, the ink on the polymer image was transferred onto the blanket 112. Conductive urethane rubber containing carbon powder is formed on the surface of the blanket 112. Next, the pressure roll 11 rotating at the same circumferential speed as the blank roll 111 in the direction of arrow G is transferred to the blank roll 111 via the recording medium l4 made of plain paper that is transferred in the direction of arrow J.
3 (surface silicone) were placed facing each other, an image identical to the polymer image of the printing plate 110 was obtained on the recording medium 114. Ten images were obtained using the same method, and there were no major image disturbances, which were sufficiently good for practical use. At this time, the resistance value of the ink calculated from the current value of the fourth DC power source was 8200 Ω'cm. Next, after stopping the above printing and leaving the printing device in an environment of 25°C 1 relative temperature 95% for 24 hours, printing was performed in the same manner as above, and the ink also appeared on the copper surface other than a part of the volumizer. It became an attached image. The resistance of the ink at this time (measured by the fourth DC power supply 121)
was 160Ω・cm. Therefore, the first drying means 131
, the second drying means 132 blows hot air into the ink pool l03.
, and while applying voltage from the fourth DC power supply once every 30 seconds while wiping the contact area between the printing plate 110 and the second intermediate roll 10B, remove the contact with the blank roll 111 and move each roll at the printing speed. After spinning for 5 minutes, the resistance of the ink became 720Ωcm. Therefore, after cleaning the ink on the blanket with a cloth, we printed under the same conditions as the previous printing, and an image with ink adhering only to a part of the volima of the same plate as the previous printing was obtained. Next, the contact between the second intermediate roll 107 and the plate roll 109 is removed, and the first intermediate roll 105 and the second intermediate roll 107 are removed from each other.
In between, the first intermediate roll 105 is the anode, and the second intermediate roll 1 is the anode.
5 while applying a voltage of 50V so that 07 becomes the cathode.
When the second intermediate roll 107 was rotated five times at a speed of mm/sec, all of the ink on the second intermediate roll 107 was transferred onto the first intermediate roll 105. Next, the first intermediate roll 105 and the second intermediate roll 107
During printing, a voltage of 30 V was applied between the first intermediate roll 105 and the ink carrying roll 101 so that the first intermediate roll 105 became the cathode and the ink carrying roll 101 became the anode. When the coating roll 104, first intermediate roll 105, and ink carrying roll 101 were rotated in the same direction at a circumferential speed of 5 mm/sec, all of the ink on the first intermediate roll 105 was transferred onto the ink carrying roll 101. ．． Next, the printing plate 110 is removed, and the contact between the pressure roll 113 and the blanket 112 is removed, and the cleaning ink layer 1l7 (same as the ink described above) is brought into contact with the blanket 112, which had not been in contact, and the cleaning roll 115 is used as an anode. With Branroll II1 as the cathode, 30
Applying a voltage of V, the blank roll 111 is moved in the F direction, the cleaning roll 115 is moved in the H direction, and the cleaning coating roll 116 is moved in one direction, all at 5 mm/sec.
When the blank roll 111 was rotated at a circumferential speed of 5 times, all of the ink on the Plancket 112 was removed. [Effects of the Invention] As explained above, the image forming method, image form, or apparatus of the present invention satisfies practical demands such as ease of handling, environmental stability, and cost in high-volume printing, and is particularly suitable for use in high-humidity environments. It is excellent in that stable and good images can be obtained even at the bottom.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of the image forming apparatus of the present invention, and FIG. 2 is a graph showing the relationship between the water content of the ink and the volume resistivity in the example. 101... Ink carrying roll 2... Ink 103... Ink reservoir 104... Coating roll 18... First DC power supply 05... First intermediate roll 06... First ink thin layer l9...Second DC power supply 07...Second intermediate roll 08...Second ink thin layer 2l...Fourth DC power supply 3l...First drying means 32...Second drying means 09 ... Plate roll 10 ... Printing plate 20 ... Third DC power supply 5 ... Cleaning roll 6 ... Coating roll 7 ... Cleaning ink layer 4 ... Recorded object 3 ... Pressure roll

Claims (1)

[Claims] 1) An image forming method comprising the step of sandwiching adhesive ink whose adhesion to the surface of at least one electrode is reduced by applying a voltage between a pair of electrodes, applying a voltage in an imagewise manner, and transferring the adhesive ink. An image forming method comprising the step of removing water contained in the ink before and/or at the same time as applying the voltage. 2. The image forming method according to claim 1, further comprising the step of: 2) detecting the water content of the ink. 3) An image forming method comprising the step of sandwiching an adhesive ink whose adhesion to the surface of at least one electrode is reduced by applying a voltage between a pair of electrodes, applying a voltage in an imagewise manner, and transferring the ink. An image forming method comprising the step of measuring electrical resistance and/or electrical conductivity of. 4) The image forming method according to claim 2, wherein the moisture content is detected by measuring electrical resistance and/or electrical conductivity of the ink. 5) An image forming apparatus comprising a means for sandwiching adhesive ink whose adhesion to the surface of at least one electrode is reduced by applying a voltage between a pair of electrodes and transferring the adhesive ink by applying a voltage imagewise. An image forming apparatus having means for removing water contained in the ink before and/or at the same time as application. 6) The image forming apparatus according to claim 1, further comprising means for detecting the water content of the ink. 7) An image forming apparatus comprising a means for sandwiching adhesive ink whose adhesion to the surface of at least one electrode is reduced by applying a voltage between a pair of electrodes and transferring the ink by applying a voltage in an imagewise manner. An image forming apparatus having means for measuring electrical resistance and/or electrical conductivity of. 8) The image forming method according to claim 6, wherein the moisture content detection means is a means for measuring electrical resistance and/or electrical conductivity of the ink.