JP4692788B2 - Printing method to include nanobubbles in fountain solution used in offset printing - Google Patents

Description

  The present invention relates to a printing method in which nanobubbles are included in a dampening solution used in offset printing.

  In conventional offset printing, ink is selectively applied only to the image area on the printing plate. Therefore, a water film is formed on the non-image area so that the ink is not transferred. This utilizes the chemical repulsive nature of water and oil. This water is called fountain solution. The purpose of the fountain solution is to prevent dot thickening, which causes extra ink to adhere to the image area on the plate, and to prevent ink from adhering to non-image areas. Protect the printing plate from oil and scratches. The ink is emulsified, scattered, and adhered to the non-image area. Cooling the elevated temperature of the ink roller and printing plate during printing. The properties required for fountain solution are as follows. The surface tension should be reasonably low and the ink difficult to emulsify so that good printing is possible with as little water as possible. However, if the surface tension is too low, the transferability of the ink is lowered. It has excellent hydrophilicity and plate surface protection for non-image areas, and has plate surface detergency. Stable chemical properties without deteriorating the image area. In some cases, fresh water is used as the fountain solution, but in many cases, an etchant (concentrated solution added to the fountain solution) is mixed for the purpose of improving the wetting and improving the surface-adjusting effect. The types of etchants include alkaline, neutral, acidic, alcohol type, and non-alcohol type. Moreover, IPA (isopropyl alcohol has a role of lowering the surface tension of dampening water with almost no influence on the pH value of dampening water as a dynamic surface tension adjusting agent. As a result, the coating film of the fountain solution (etch solution only) becomes thinner and more uniform, and the fountain solution can be reduced. There is also a bactericidal effect.) As alternatives to IPA, there are surfactants, alcohol derivatives, and non-alcohol derivatives. In the case where only the etchant is mixed in the fountain solution, in the case where only IPA or an alternative to IPA is mixed, both the etchant and IPA or an alternative to IPA may be used in combination. There are many alternative combinations of etchant, IPA, and IPA depending on the purpose, such as when the etchant itself is mixed with IPA or IPA substitutes from the beginning. (For example, refer nonpatent literature 1.)

  The fountain solution used in the above-described offset printing requires etching solution, IPA, or alternative concentration management of IPA, temperature management, and bacteria countermeasures. (For example, refer nonpatent literature 1.)

  It is necessary to keep the concentration of the fountain solution at an appropriate value in order to sufficiently exhibit the effect of the etchant in the fountain solution, IPA, or IPA. Concentration management based on electrical conductivity is prevalent in fountain solution concentration management. The conductivity and concentration change in a substantially linear relationship within the range of the concentration used as the fountain solution, and are easy to manage and have high stability. In addition, a quantitative dilution method that mixes mechanically at a constant rate. Some adopt a pH mixing method in which the concentration is mixed and controlled by the pH value. (For example, refer nonpatent literature 1.)

  Inks used in offset printing are generally designed to be used at 25 degrees, and at temperatures higher than that, the halftone dots are thick and the ink is easily emulsified. Therefore, it is desirable to cool the ink to about 25 degrees on the plate surface. For this reason, the dampening water supply device is generally provided with a cooling device, and dampening water whose temperature is controlled at 15 to 20 degrees is supplied. (For example, refer nonpatent literature 1.)

  Since offset printing is performed in a high-temperature and high-humidity environment, bacteria may be generated in the dampening water supply device, water boat, pipe, filter, etc., resulting in a sludge shape, which may hinder the dampening water supply. As a countermeasure against bacteria, there is a method of putting a preservative in dampening water. (For example, refer nonpatent literature 1.)

  The dampening water supply method is roughly classified into an AD (intra-arch dampening) method and an ITD (Ink Train Damping) method. The AD method has a dedicated swim roller, and directly supplies water to the printing plate. The ITD method is a method of supplying dampening water to a part of the inking device. The type of dampening water supply device is a spiral brush method (supplies dampening water to the water boat with dampening water supply device, kept at a certain level, blows dampening water with a brush, and rotates the roller. The fountain solution is carried and offset printing is performed, and the structure is simple and relatively inexpensive, but the management of the brush that blows water is important. .), Spray method (a method in which dampening water pressurized by a pump is atomized and sprayed by a spray nozzle. If the nozzle is clogged, the dampening water stops instantly, so the nozzle tip is not washed and foreign matter is not sent. It is important to keep the equipment and piping system clean.), Rotor system (dropping dampening water on a mortar-shaped rotor rotating at high speed, and spraying the dampening water into a mist by its centrifugal force Dampening water is supplied continuously and is uniform Has excellent stability. Water programs, since it is fairly finely freely set, as a spray method, there is excellent operability.). (For example, refer nonpatent literature 2.)

Japanese Laid-Open Patent Publication No. 07-304151 (for example, see Patent Document 1) discloses a circulation supply device or ink call circulation water supply device for lithographic printing water characterized by having an ozone sterilization device. Yes. This technology enables long-term stability by preventing the decay of dampening water for lithographic printing or ink roll circulating water by sterilizing the decay of circulating water, which has been difficult in the past, using ozone gas. .

  The microfilm (see, for example, Patent Document 2) of Japanese Utility Model Application No. 01-152004 (Japanese Utility Model Application Publication No. 03-090940) is provided with a sterilizing means in the middle of a supply system or a return system including a water tank. A fountain solution apparatus for a printing press characterized by being arranged is disclosed.

  Conventionally, various devices for various nanobubbles and methods for using nanobubbles are known. Japanese Unexamined Patent Application Publication No. 2004-121962 (for example, see Patent Document 3) discloses a nanobubble device and a method of using the nanobubble. It utilizes the characteristics of nanobubbles such as buoyancy reduction, surface area increase, surface activity increase, local high-pressure field generation, surface active action by realizing electrostatic polarization, and bactericidal action. More specifically, when they are related to each other, an adsorption function for dirt components, a high-speed cleaning function for an object surface, and a sterilization function are exhibited. And it is disclosed that various functions can wash | clean various objects by these functions with high function and low environmental load, and can purify polluted water. Nanobubbles are produced by electrolyzing water and applying ultrasonic vibration to the water.

  There are several nanobubble generation methods and nanobubble generation apparatuses, for example, the following disclosures are made.

  Japanese Unexamined Patent Application Publication No. 2008-030002 (see, for example, Patent Document 4) discloses an ultrafine bubble generation method and generator capable of generating an ultrafine bubble with a fluid to be treated with a simple structure, and the generator. A processing apparatus using the above is disclosed. In the method of generating ultrafine bubbles, high pressure fluid is jetted to the raw fluid to be processed to generate ultrafine bubbles, and a plurality of jet lines formed by jetting the high pressure fluid are a predetermined small region of the raw fluid. It is characterized in that the direction of each injection line is made different so as to pass through the inside.

  Japanese Patent Laying-Open No. 2005-245817 (for example, refer to Patent Document 5) discloses a nanobubble characterized by abruptly reducing the microbubbles by applying a physical stimulus to the microbubbles contained in a liquid. A manufacturing method is disclosed. The microbubbles are rapidly reduced by applying physical stimulation to the microbubbles contained in the liquid.

Japanese Patent Laying-Open No. 2006-289367 (see, for example, Patent Document 6) discloses a bubble generating device that can realize the miniaturization of generated bubbles with a simple and inexpensive configuration. The bubble generating device according to the present invention includes a pump having an inlet connected to a liquid source, a gas introduction unit connected to the suction side of the pump for introducing a gas at a predetermined flow rate, and an agitation connected to a pump outlet. A screw-shaped rotary vane that is provided in the stirring chamber and is rotationally driven and performs stirring operation by pushing down undissolved air bubbles above the stirring chamber into the liquid below the stirring chamber under the discharge pressure of the pump And a bubble separation chamber having an outlet for separating the bubbles at the communicating portion with the agitation chamber and introducing the bubble dissolved liquid and taking out the bubble dissolved liquid under the discharge pressure of the pump, and the outlet of the bubble separation chamber And a decompression device that decompresses and discharges the bubble solution.
Newspaper printing handbook revised edition p. 88 p. 89 p. 90 p. 91 Newspaper printing handbook revised edition p. 91 p. 92 p. 93 p. 94 p. 95 Japanese Patent Laid-Open No. 07-304151 Microfilm of Japanese Utility Model No. 01-152004 (Japanese Utility Model Application Publication No. 03-090940) JP 2004-121962 A JP 2008-030002 A JP 2005-245817 A JP 2006-289367 A

  With dampening water used in conventional offset printing (for example, see Non-Patent Document 1), at the start of operation of the offset printing machine, it is slow to wash unnecessary ink on the image area and non-image area of the printing plate. Therefore, defective paper due to ink smearing occurs until the printed matter becomes a product. During printing, it is necessary to print while increasing the amount of dampening water used depending on the situation so that ink stains do not occur on the printed matter. During acceleration / deceleration, the ink and dampening water are unbalanced, and ink stains are likely to occur on the printed matter. For this reason, it is necessary to temporarily increase the amount of dampening water used during printing. Immediately before the operation is stopped, ink stains are particularly likely to occur on the printed matter, and it is necessary to temporarily increase the amount of dampening water used during printing and during acceleration / deceleration. Nevertheless, ink stains may occur on the printed matter, resulting in defective paper. For this reason, with dampening water used in conventional offset printing, offset printing is performed while increasing the amount of dampening water used excessively in order to prevent the occurrence of ink stains on the printed matter. Alternatively, increase the concentration of the etchant, IPA, or IPA that is mixed with the fountain solution. Or both ink smear measures are necessary.

  Ink smear countermeasures for printing while increasing the amount of dampening water used excessively, because the dampening water that is the basis of offset printing cannot be printed in as small a quantity as possible, the ink becomes thinner and the ink density and transferability of the printed matter Becomes unstable. For this reason, it is necessary to increase the amount of ink used in order to stabilize the concentration and transferability of the ink. Increasing the amount of ink used may cause excess ink to adhere to the non-image area, resulting in ink stains on the printed matter. Since ink stains occur on the printed matter, it is necessary to increase the amount of dampening water. Since the above vicious cycle is repeated during printing, the amount of defective paper due to the amount of dampening water used, the amount of ink used, ink stains, etc. increases as printing is performed (printing time becomes longer). More specifically, excessive emulsification of the ink occurs (in offset printing, since the ink is constantly in contact with water, emulsification of the ink is unavoidable, and an emulsification phenomenon of the water-in-oil emulsion occurs. Excessive emulsification changes properties such as poor fluidity and lower tack, causing poor transfer and insufficient density, and in severe cases it becomes incapable of printing such as ink stains and roller stripping.) Set-off occurs due to poor ink transfer on the paper (unprinted ink on the printing surface retransfers to the opposite surface). Printing with an insufficient ink density causes dry-down (the smooth ink film surface immediately after printing has a vivid color tone and a high density value, but as the drying progresses, the ink penetrates the paper and the ink film gradually becomes rough. As a result, light is diffusely reflected in various directions, resulting in a decrease in density value and loss of vividness.) Watermarks are generated (raindrop spots on the seal surface). A ghost occurs (the shadow of another pattern appears on part of the pattern). Slurs occur (whisker-like ink stains occur in the printing direction of halftone dots). Water rises (dampening water accumulates between the ink source roller and doctor blade during printing, and ink supply becomes abnormal). The paper stretches excessively and the printing tension is not stable. Since the printing tension is not stable, the registration of the printed material is not stable. The above problems arise.

  Also, when printing is performed, paper dust and ink residue accumulate on the plate, blanket, diamond roller, watering roller, and inking roller, so the printed material is piled (the printing surface is white and the photo surface is scaled), Hickey (printing surface) A white donut-shaped omission occurs). There is a problem that the printing surface quality of the printed material is deteriorated due to the occurrence of piling and hickey.

  In order to prevent ink stains that increase the concentration of the etchant, IPA, or IPA that is mixed with the fountain solution, the pH value of the fountain solution is reduced by raising the concentration of the etchant, IPA, or IPA to an appropriate level. If it is too high (acidity is strong), the metal in the non-image area is melted and causes ink stains. In addition, the drying of the ink is delayed, and the printing durability of the printing plate is lost, resulting in poor plate durability. When the pH value of the fountain solution is too high (the alkalinity is too strong), the hydrophilic film in the non-image area is easily broken. In addition, since ink and water are easily mixed, a problem that causes ink smearing occurs.

  A particularly serious problem with conventional fountain solution is to increase the concentration of the etchant, IPA, or IPA that is mixed with the fountain solution to prevent the occurrence of ink stains on the print. In addition, since it is necessary to perform offset printing while excessively increasing the amount of dampening water used, the amount of alternative use of the etchant, IPA, or IPA and the amount of water supplied increase. In most cases, harmful chemicals are used to replace the etchant, IPA, and IPA. In particular, IPA corresponds to a hazardous material class 4 alcohol, and is also a second type organic solvent in the organic solvent poisoning prevention regulations. IPA has an excellent property as a dampening water additive, but it also causes deterioration of the rubber roller. In recent years, IPA reduction has been screamed in the printing industry. The reason for this is that IPA is a 100% VOC (volatile organic compound) solvent that is a highly flammable liquid (flash point 11.7 degrees), and more than 90% is volatilized during use. It is mentioned that. In order to solve the problem of using IPA, a dampening solution for offset printing has been devised to replace IPA. Surfactants, alcohol derivatives, and non-alcohol derivatives are used as alternative fountain solutions for these IPAs. These fountain solution compositions provide fountain solution properties similar to IPA from the viewpoint of surface tension, viscosity, and emulsification suitability, but substitute for adjustment of the dynamic surface tension of IPA itself and bactericidal action. It has not reached. Traditionally, IPA has been used in dampening water from several percent to tens of percent. (In the Japan Printing Industry Federation, the IPA content is 5% or less for materials using IPA. Rotation of the fountain solution, which has not been a problem in the past due to its bactericidal action, is a major problem in the dampening water alternative to IPA. For this purpose, it has been proposed to add benzoic acid and its derivatives as preservatives. However, these preservatives cannot be sufficiently used as a fountain solution for offset printing. Due to the above factors, the use amount of the etchant, IPA, and IPA is increased, which causes problems not only in cost but also in safety, workability, and environment.

  In addition, the thickening of dots that cause extra ink to adhere to the image area of the plate surface, which is the purpose of dampening water due to the use of offset printing presses, plate materials, paper, ink, etchant, IPA and IPA. Prevent ink from adhering to the non-image area of the printing plate, and quickly wash away the ink adhering to the non-image area due to emulsification and scattering. Since the purpose of the fountain solution cannot be obtained stably, there is a problem that ink stains occur on the printed matter.

  Use the conventional dampening water without cleaning the dampening water supply device for a long time. In addition, the dampening water may rot due to the influence of the use status of the offset printing press, paper, ink, etchant, IPA, IPA substitution, dampening water circulation, and the like. When the fountain solution rots, not only does it give off odors, but bacteria are generated and adhere to the fountain solution tank, the piping to the printing press, and the water fountain of the printing press. The printed matter is soiled by bacteria. Further, the color of the fountain solution, the contamination, the pH change, and the viscosity are lowered, and the properties of the fountain solution are changed. Each time, cleaning or dampening water must be readjusted, which causes a problem in work. The generation of bacteria in the fountain solution is due to the growth of various fungi that are present in the water, but the non-image area of the printing plate is not included in the fountain solution composition for offset printing. In order to protect, various water-soluble polymer compounds represented by gum arabic and carboxymethylcellulose are used as a desensitizing agent. Due to these contents, the fountain solution has a problem that the fungi are prone to grow and rot due to long-term storage and use as compared with normal water.

  In offset printing, waste water is generated by excess dampening water. is there.). Further, paper dust, ink residue, and bacterial stains are generated in the dampening water supply device, water boat, pipe, filter, and the like. Therefore, it is necessary to clean regularly, and wastewater is generated during cleaning. If the wastewater contains a lot of paper powder, ink residue, bacteria, etc., and BDO (biochemical oxygen demand), SS (floating matter), etc. show values above the standard value, it is necessary to treat the wastewater. There is. Usually, it can be made within the standard range by filtration or neutralization treatment. However, when bad odor or BOD value is high, there is a problem that treatment such as biological treatment or chemical oxidation method is required.

  The conventional fountain solution used in offset printing has various problems as described above.

  Japanese Laid-Open Patent Publication No. 07-304151 (for example, refer to Patent Document 1) discloses a lithographic dampening water circulation supply device or an ink roll circulation water supply device characterized by having an ozone sterilization device. Yes. This technology enables long-term stability by preventing the decay of dampening water for lithographic printing or ink roll circulating water by sterilizing the decay of circulating water, which has been difficult in the past, using ozone gas. . However, by preventing the fountain solution from corroding, it is possible to prevent the printed matter from being soiled by bacteria and the effect of the fountain solution from decreasing, but this is not a device that improves the original effect of the fountain solution. Therefore, the effects of reducing ink stains on the printed matter, improving the printing surface quality of printed matter, and improving workability beyond the original effect of the fountain solution cannot be obtained. In addition, ozone is considered to be decomposed into oxygen molecules and oxygen ions in the raw water, and these oxygen ions exhibit sterilizing ability. However, an ozone sterilization apparatus that simply injects ozone into raw water has insufficient decomposition of ozone in the raw water, so that its sterilizing effect is also insufficient. Further, since the ozone concentration changes due to the temperature change in the ozone generator, it is necessary to control the temperature of the ozone generator constantly, which causes an increase in the cost of the apparatus. Daily management at the site of use is also required. Furthermore, when the ozone concentration cannot be controlled to a constant level, the sterilization process is more than necessary, and there is a problem that the material that is the object of ozone sterilization is damaged. Further, when the pressure is supplied, the processing time can be shortened, but it is difficult to obtain an appropriate processing time. On the other hand, it is difficult to obtain an appropriate processing time even when supplying under reduced pressure. Moreover, after the ozone water is generated, the ozone concentration in the water rapidly decreases and returns to its original state. Therefore, conventionally, it is necessary to use ozone water immediately after generating ozone water, which is not suitable for long-term storage. Although low concentrations of ozone are beneficial to the human body, higher concentrations have an effect on the human body, and direct inhalation of high-concentration ozone gas may lead to fatal accidents depending on the amount. In use, there is a problem that the effect of ozone on the human body must be taken into consideration, such as intermittent use instead of continuous use.

  The microfilm (see, for example, Patent Document 2) of Japanese Utility Model Application No. 01-152004 (Japanese Utility Model Application Publication No. 03-090940) is provided with a sterilizing means in the middle of a supply system or a return system including a water tank. A fountain solution apparatus for a printing press characterized by being arranged is disclosed. However, it cannot be said that a means for removing the dirt of the fountain solution by disposing the sterilization means (filter or the like) in the dampening water supply device is not sufficiently effective. Insufficient maintenance and inspection may cause bacteria to stay on the filter used for filtration, which may lead to a suitable environment for the growth of fungi. It is.

  Japanese Unexamined Patent Application Publication No. 2004-121962 (for example, see Patent Document 3) discloses a nanobubble device and a method of using the nanobubble. However, it has been disclosed that water containing nanobubbles can be effectively used for washing objects, purifying contaminated water, applying to living bodies, or chemical reactions. There is no suggestion. The water used is ultrapure, electrolyzed water, alkaline ionized water, or acidic water. Moreover, only the treatment of water-based fluids such as waste water is described, and application to other types of fluids is not considered at all. A printing method in which nanobubbles are included in dampening water and used for offset printing has never been considered. In addition, electrolysis of water and application of ultrasonic vibration to the water make nanobubbles, so that the structure of the generator is complicated, and there are cost problems when producing a large number of nanobubbles .

  In addition, the conventional methods of using nanobubbles are used in various ways. In the field of cleaning, it is used for the purpose of efficiently and completely cleaning each object with high functionality and low environmental load. ing. Therefore, the conventional idea of using nanobubbles is that, like offset printing, surface tension problems of water and ink, etch solutions, IPA and IPA substitution problems, printing press problems, paper problems, printed surface of printed matter There is a problem of quality, etc., and water is repelled by a micron thin film formed on the plate, and ink is printed while repelling water. It is not considered at all to use nanobubbles for a liquid having a complicated action.

  As described above, offset printing has a wide variety of printing conditions such as printing presses, printing plates, paper, and ink. Printing using conventional fountain solution causes problems such as ink smears and dampening. Problems with excessive use of water, problems with the use of etchant, IPA and IPA alternatives, print surface quality problems, bacteria problems, wastewater problems, and the generation of defective paper causes ink, paper, water There were problems of cost such as etchant, replacement of IPA, IPA, offset printing machine, power of peripheral machines, safety, workability, and environment. There has been a demand for an offset printing method that can solve the various problems described above.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an offset printing method for solving the above-mentioned problem that has occurred by performing offset printing using a conventional fountain solution.

  In order to achieve the above object, the present invention is to include nanobubbles in the fountain solution used for offset printing.

  In the present invention, the nanobubble generator is attached to the dampening water tank of the dampening water supply device that supplies dampening water to the offset printing press. The nanobubble generator uses air to immerse nanobubbles in the fountain solution without using chemicals. A printing method is characterized in that dampening water containing nanobubbles is continuously supplied to an offset printing machine by a dampening water supply device to perform offset printing.

  The conventional fountain solution is the problem of how to make the cleaning effect and surface tension suitable by replacing the etchant, IPA, or IPA. Excessive amount of fountain solution is used to prevent the occurrence of ink stains on the printed matter. Offset printing while increasing to Increase the etchant, IPA, or alternative concentration of IPA to be mixed in the fountain solution. Or, both ink smudge countermeasures were necessary, but the present invention improves the cleaning effect and surface active action over conventional dampening water by including nanobubbles with cleaning effect and surface active action in the dampening water. can do. Therefore, offset printing can be performed by reducing the amount of dampening water used than before. An alternative concentration of etchant, IPA, or IPA can be lowered than before. More specifically, at the start of operation of the offset printing press, unnecessary ink in the image area and non-image area of the printing plate is cleaned faster than before, so that the printed matter becomes a product faster and the ink stains. Defective paper due to can be reduced. During printing, the occurrence of ink stains on the printed matter is reduced, so that the amount of dampening water used is not increased excessively, and offset printing can be performed with a reduction compared to the prior art. During acceleration / deceleration, the ink and dampening water balance becomes worse, so ink smears are more likely to occur. However, it is possible to reduce the occurrence of ink smears on the printed matter without temporarily increasing the amount of dampening water used during printing. . Immediately before the operation is stopped, ink stains are particularly likely to occur on the printed matter, but the occurrence of ink stains can be reduced without temporarily increasing the amount of dampening water used during printing and during acceleration / deceleration.

  Since the dampening water, which is the basis of offset printing, can be printed in as small a quantity as possible, the ink during printing is not diluted and the ink density and transferability are stabilized. Therefore, it is not necessary to increase the amount of ink used in order to stabilize the ink concentration and transferability as in the prior art. Since there is no need to increase the amount of ink used, excess ink does not adhere to the non-image area and ink stains do not occur on the printed matter. There is no need to increase the amount of dampening water again because no ink smears on the printed matter. Even if imprinting is performed without having to repeat the conventional vicious cycle during printing, the amount of dampening water used, the amount of ink used, and defective paper due to ink stains can be reduced. In addition, excessive emulsification of ink, which was in conventional fountain solutions. (Transfer defects, insufficient density, ink stains, roller stripping, etc.). Set-off occurred. Occurrence of drydown. The occurrence of a watermark. Generation of ghost. The occurrence of slurs. Occurrence of rising water. Unstable printing tension. Unstable print registration. The above problems can be solved.

  In addition, even when imprinting, dampening water containing nanobubbles is washed during printing of paper dust and ink residue deposited on the printing plate, blanket, diamond roller, watering roller, and ink application roller. Deposition can be prevented. As a result, it is possible to reduce the generation of printed material piling and hacky. Since no piling or hickey is generated, the ink can be stably transferred to the image area, so that the printing surface quality of the printed material can be improved as compared with the conventional art. Even if imprinted more than before, it is possible to reduce the deterioration of the printing surface quality of the printed matter.

  Also, by increasing the concentration of the dampening solution etchant, IPA, or IPA to an appropriate level or more, the ink stains that occur when the pH value of the dampening solution is too low or too high are reduced. it can.

  Increase the concentration of the etchant, IPA, or IPA that is mixed with the fountain solution to prevent the occurrence of ink stains on the printed matter, which is a major problem with the conventional fountain solution. While using offset printing, the use of etchant, IPA, or IPA alternatives and the amount of water supply increase. By using a dampening solution containing nanobubbles in the offset printing of the present invention, the problem is that The etchant, IPA, or alternative concentration of IPA can be lowered. Since offset printing can be performed by reducing the amount of dampening water used compared to the prior art, the amount of use of the etchant, IPA, or IPA, and the amount of water supply can be reduced. Can solve cost, safety, workability and environmental problems.

  A network where extra ink adheres to the image area of the printing plate, which is the purpose of dampening water because it is less affected by the use of the offset printing press, plate material, paper, ink, etchant, IPA, or IPA. Prevent spot thickening, prevent ink from adhering to the non-image area of the printing plate, and quickly wash away ink adhering to the non-image area due to emulsification. Since the purpose of the fountain solution can be obtained stably, it is possible to reduce the occurrence of ink stains on the printed matter.

  Use the conventional dampening water without cleaning the dampening water supply device for a long time. In addition, the dampening water may rot due to the influence of the offset printing press usage, etchant, IPA or IPA replacement, dampening water circulation, etc. In addition, since offset printing is performed while the nanobubbles are washed, it is possible to reduce paper dust, ink residue, and bacterial stains generated in the dampening water supply device. Therefore, it can prevent that dampening water decays.

  By using dampening water with nanobubbles in offset printing of the present invention, the amount of dampening water used can be reduced and offset printing can be performed compared to conventional methods, reducing waste water from excess dampening water. it can. In addition, since the concentration of the etchant, IPA, or IPA substitute can be lowered as compared with the prior art, the etchant, IPA, or BDO, SS, etc. contained in the surplus water of the dampening water can be reduced. Since the dampening water supply device and the like are offset printed while the dampening water containing nanobubbles is washed, the number of cleanings of the dampening water supply device and the like can be reduced. As a result, the amount of wastewater treated can be reduced.

  The effects of the present invention as described above can solve various problems associated with conventional fountain solutions used in offset printing.

  The fountain solution containing the nanobubbles of the present invention is stable with no change in chemical properties with the conventional fountain solution because it uses only the air in the nanobubble generator without using chemicals when the nanobubbles are included. In addition, since no chemicals are used, there are no running costs, safety, workability, and environmental problems. Since the nanobubble has the property that it can exist in the fountain solution for a long time, it exists in the fountain solution without using the offset printing press for a certain period of time. In addition, since the nano bubble generator is simply attached to the dampening water supply device of the current offset printing press, the initial cost can be kept low.

  Since the present invention is a printing method in which nanobubbles are included in conventional dampening water used in offset printing, various offset printing machines currently used, dampening water supply methods, supply devices, concentration management, temperature management, It can be used to replace bacteria, plate material, paper, ink, etchant, IPA and IPA.

  In an embodiment of the present invention, a nanobubble generator is attached to a dampening water tank of a dampening water supply device of an offset printing press. The alternative concentration setting of the etchant, IPA, or IPA mixed with the dampening water by the dampening water supply device is lowered as compared with the conventional case. A nanobubble generator generates nanobubbles using air without using chemicals, and includes the nanobubbles in the fountain solution. The dampening water containing nanobubbles is returned from the nanobubble generator to the dampening water tank. While repeating this process, dampening water containing nanobubbles is continuously supplied from the dampening water supply device to the offset printing machine while being repeated. Offset printing is performed by reducing the amount of dampening water containing nanobubbles compared to conventional dampening water.

  In addition, in the process of including nanobubbles in the fountain solution, the water temperature of the fountain solution may increase due to the generation method of the nanobubble generator. In that case, make the temperature control appropriate with the cooler of the dampening water supply device. (Water temperature is unlikely to be a problem when used for conventional cleaning, but dampening water temperature control is important in offset printing.)

  The nanobubble used in the present invention means that the bubble diameter is 1 μm or less. Such fine bubbles rapidly rise in the liquid and burst at the liquid level, whereas the rising speed is slow and the bubbles remain in the liquid for a long time. Then, the fine bubbles in the liquid are pressurized by the interfacial tension generated between the interface between the gas phase and the liquid phase, and become smaller. Furthermore, since the fine bubbles are negatively charged and repel each other, they do not combine and the bubble concentration does not decrease. For this reason, the fine bubbles can be dispersed in the liquid at a high density. (Dampening water using microbubbles has a problem that since the size of the bubbles is large, it is difficult to clean nano-sized regions and to perform surface-active action. If the microbubble generator is stopped for several hours, the microbubbles will disappear in a few hours.)

  According to the printing method using the dampening water containing nanobubbles in the offset printing of the above embodiment, when the offset printing machine starts operation, during printing, during acceleration / deceleration, when the operation is stopped, the usage situation of the offset printing machine, Reduce the occurrence of ink stains on printed matter due to the influence of plate materials, paper, ink, etchant, IPA and IPA. The dampening water that is the basis of offset printing can be printed with as little amount as possible. The printing surface quality of the printed matter is improved compared to the conventional one. Reduce printing surface quality degradation even if imprinted more than before. Printing workability can be improved as compared with the prior art. It is possible to clean paper dust, ink residue, and bacterial stains generated in dampening water supply devices, water boats, pipes, and filters. The amount of dampening water wastewater can be reduced. Cost, safety, workability, and environmental problems such as ink, paper, water, etchant, IPA, IPA substitution, offset printing machine, and power for peripheral machines can be solved. The above effects of the present invention can be obtained.

[0047]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing the configuration of the present invention. The nanobubble generator 1 is attached to the dampening water tank of the dampening water supply device 2 of the offset printing machine 3. The alternative concentration setting of the etchant, IPA, or IPA mixed with the dampening water by the dampening water supply device 2 is lowered as compared with the conventional method (1). The fountain solution is passed through the nanobubble generator 1 from the fountain solution supply device 2 ((2)). The nanobubble generator 1 uses air to add nanobubbles to the fountain solution. The dampening water containing nanobubbles is returned from the nanobubble generating device 1 to the dampening water tank of the dampening water supply device 2 ((3)). While repeating this process ((2), (3)), the dampening solution containing nanobubbles is continuously supplied during printing from the dampening solution supply device 2 to the offset printing machine 3 ((4)). . The amount of dampening water containing nanobubbles is reduced from the amount of conventional dampening water used, and offset printing is performed by the offset printing machine 3 (5).

  FIG. 2 is an explanatory view showing a configuration when the present invention is used in a newspaper offset rotary press. The nanobubble generator 1 is attached to the dampening water tank of the dampening water supply device 4 for the newspaper offset rotary press of the newspaper offset rotary press 5. The concentration setting of the etchant mixed with the dampening water by the dampening water supply device 4 for a newspaper offset rotary press is lowered as compared with the conventional method (8). Dampening water is passed through the nanobubble generator 1 from the dampening water supply device 4 for newspaper offset rotary press ((6)). The nanobubble generator 1 uses air to add nanobubbles to the fountain solution. The dampening water containing the nanobubbles is returned from the nanobubble generating device 1 to the dampening water tank of the dampening water supply device 4 for the newspaper offset rotary press ((3)). While repeating this process ((3), (6)) during printing, dampening water containing nanobubbles is continuously supplied from the dampening water supply device 4 for newspaper offset rotary press to the newspaper offset rotary press 5. Supply (7). The amount of dampening water containing nanobubbles is reduced from the amount of conventional dampening water used, and offset printing is performed on the newspaper offset rotary press 5 (5).

  According to the offset printing method using the fountain solution containing nanobubbles of the above embodiment, the effect of the present invention can be obtained.

It is explanatory drawing which shows the structure of this invention. It is explanatory drawing which shows a structure in the case of using this invention with a web offset press for newspapers.

DESCRIPTION OF SYMBOLS 1 Nano bubble generator 2 Dampening water supply device 3 Offset printing machine 4 Dampening water supply device for newspaper offset rotary press 5 Newspaper offset rotary press (1) Alternative of etchant, IPA, or IPA mixed with dampening water Lower the density setting than before.
(2) Pass the dampening water from the dampening water supply device.
(3) Return the dampening water containing nanobubbles.
(4) Continuously supply dampening water containing nanobubbles to the offset printing press.
(5) Offset printing is performed by using less amount of dampening water containing nanobubbles than conventional dampening water.
(6) Pass dampening water from a dampening water supply device for newspaper rotary press.
(7) Continuously supply fountain solution containing nanobubbles to the newspaper offset press.
(8) Lower the concentration setting of the etchant mixed in the dampening water.

Claims (15)

The printing method characterized by including nanobubbles in the dampening water used in offset printing. A printing method characterized in that nanobubbles are contained in a dampening water mixed with an alkaline etchant used in offset printing. A printing method characterized by including nanobubbles in a dampening water mixed with a neutral etchant used in offset printing. A printing method characterized in that nanobubbles are contained in a dampening water mixed with an acidic etchant used in offset printing. A printing method characterized in that nanobubbles are contained in a dampening water mixed with an alcohol type etchant used in offset printing. A printing method characterized in that nanobubbles are contained in a dampening water mixed with a non-alcohol type etchant used in offset printing. A printing method characterized in that nanobubbles are included in a dampening water mixed with isopropyl alcohol (IPA) used in offset printing. A printing method comprising adding nanobubbles to a fountain solution mixed with a surfactant that is an alternative to isopropyl alcohol (IPA) used in offset printing. A printing method characterized in that nanobubbles are contained in a dampening water mixed with an alcohol derivative instead of isopropyl alcohol (IPA) used in offset printing. A printing method characterized in that nanobubbles are contained in a dampening water mixed with a non-alcohol derivative instead of isopropyl alcohol (IPA) used in offset printing. The printing method according to claim 2, wherein isopropyl alcohol (IPA) is further used in combination with the fountain solution. The printing method according to any one of claims 2 to 4, wherein a surfactant that is an alternative to isopropyl alcohol (IPA) is further used in combination with the fountain solution. The printing method according to any one of claims 2 to 4, wherein an alternative alcohol derivative of isopropyl alcohol (IPA) is further used in combination with the fountain solution. The printing method according to claim 2, wherein a non-alcohol derivative alternative to isopropyl alcohol (IPA) is further used in combination with the dampening water. The dampening water is washed by offset printing to wash the dampening water supply device, water boat, pipe, and filter through which dampening water passes. The printing method described.

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