JP2002273854A - Coating unit, printing equipment and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and surely prevent a ground stain of a plate without necessitating a temperature control of the plate, in regard to printing for which a plate material dispensing with dampening water is used. SOLUTION: A layer of a barrier liquid 12 not showing compatibility with a resin which ink 10 contains is formed on the surface of the layer of ink 11 of an inking roller 10, as shown in Fig. 1 (A). Then the ground stain of the surface of the plate 20 can be prevented, since the layer of the barrier liquid 12 exists between the ink 11 and the plate 20. When the barrier liquid 12 is dispersed like particles on the surface of the layer of the ink 10, as shown in Fig. 1 (B), both the prevention of scumming of the plate 20 and the stability of inking on the plate 20 can be attained together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating unit, a printing apparatus, and a printing method. More specifically, the present invention relates to a printing plate having an ink-inlaid portion and a background portion that repels ink in a lithographic plate as in lithographic offset printing. The present invention also relates to an apparatus and a method applied to printing performed using viscous ink.

[0002]

2. Description of the Related Art In lithographic offset printing, a thin layer of water, which is a so-called fountain solution, which is generally a barrier layer for ink, is formed on the plate surface in advance during printing to prevent ink contamination on the background. . The formation of the dampening solution on the printing plate is skilled and difficult to automate. Therefore, in recent years, development of a plate using a silicone resin and requiring no dampening solution has been actively developed. However, since the fountain solution-free plate as described above does not use fountain solution in the background, the ink viscosity to be used is high and difficult to handle as compared with the plate using fountain solution. If the ink viscosity decreases due to the temperature rise, background smearing occurs. Therefore, the printing apparatus is provided with a cooling mechanism for keeping the ink viscosity constant.

In order to prevent soiling of a plate that does not require dampening solution, for example, as described in JP-A-52-116305,
There has been an example in which silicone oil has been added to ink for a long time. The added silicone oil is absorbed by the silicone resin, which is the material of the plate, and the coating of the silicone oil on the plate surface prevents soiling. In recent years, as described in, for example, JP-A-10-183045 and JP-A-8-320411, there is an example in which a silicone compound is added to a double-sided printing ink or an ultraviolet curable ink. However, there is a problem that the addition of silicone oil to the ink deteriorates the storability of the ink itself.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is simple and simple in printing using a printing plate material that does not require dampening water, without requiring temperature control of the printing plate. It is an object of the present invention to provide an apparatus and a method for surely preventing the background from being soiled.

[0005]

According to a first aspect of the present invention, an inking roller for depositing an ink on a printing plate that does not require dampening solution does not exhibit compatibility with a resin or a solvent contained in the ink. A coating unit for coating a barrier liquid, wherein the coating unit enables formation of a layer of the barrier liquid or dispersed particles of the barrier liquid on the surface of an ink layer formed on the inking roller. It is a characteristic.

According to a second aspect of the present invention, in the first aspect of the present invention, the coating unit is configured to be provided on an inking roller that is in contact with the printing plate.

According to a third aspect of the present invention, in the first or second aspect, the coating unit has a roller capable of forming the barrier liquid layer on the surface thereof, and the barrier liquid layer formed on the roller or the barrier liquid layer formed on the roller. The barrier liquid is applied to the inking roller by transferring the barrier liquid held by the roller to the inking roller.

According to a fourth aspect of the present invention, in the third aspect, the roller has a surface material using a silicone resin.

According to a fifth aspect of the present invention, in the second or third aspect, the coating unit has a porous elastic body capable of contacting the roller, and the porous elastic body is impregnated with a barrier liquid. The barrier liquid layer is formed on the surface of the roller by bringing the porous elastic body into contact with the roller.

According to a sixth aspect of the present invention, in the invention of the second or third aspect, the coating roller is formed of a porous elastic body, and the porous elastic body is impregnated with the barrier liquid to thereby form the roller. Is characterized in that it can hold the barrier liquid.

[0011] The invention of claim 7 is characterized in that, in the invention of claim 1 or 2, the coating unit has a nozzle unit in which a plurality of nozzles for spraying the barrier liquid are arranged.

According to an eighth aspect of the present invention, in the first aspect of the present invention, detecting means for detecting a background density of a printed matter printed using the printing plate, and the inking according to a detection result by the detecting means. Means for controlling the amount of the barrier liquid applied to the roller.

According to a ninth aspect of the present invention, there is provided a printing apparatus having at least a printing plate requiring no dampening solution and an inking roller for depositing ink on the printing plate, wherein a resin or a solvent contained in the ink is used. Using a liquid that does not show compatibility as a barrier liquid, in a state in which a layer of the barrier liquid or dispersed particles of the barrier liquid is further supplied to the surface of the ink layer formed on the inking roller, the ink is applied to the printing plate. The present invention is characterized by having a barrier liquid layer forming means capable of depositing.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the barrier liquid layer forming means is an application means for applying the barrier liquid to the inking roller.

According to an eleventh aspect, in the tenth aspect, the coating means is provided on an inking roller which is in contact with the printing plate.

A twelfth aspect of the present invention is the tenth or first aspect.
In the invention according to the first aspect, the application unit is a roller capable of forming a layer of the barrier liquid on a surface thereof, and applies a barrier liquid layer formed on the roller or a barrier liquid held by the roller to the inking roller. It is characterized in that the barrier liquid is applied to the inking roller by transferring.

According to a thirteenth aspect of the present invention, in the twelfth aspect, the roller has a surface material using a silicone resin.

The invention of claim 14 is the invention of claim 12 or 1
In the invention of the third aspect, the coating means has a porous elastic body that can contact the roller, and impregnates the porous elastic body with a barrier liquid to contact the porous elastic body with the roller. Forming the barrier liquid layer on the roller surface.

The invention of claim 15 is the invention of claim 12 or 1
In the invention according to 3, the coating roller is formed of a porous elastic body, and the roller is capable of holding the barrier liquid by impregnating the porous elastic body with the barrier liquid. It was done.

The invention of claim 16 is the invention of claim 10 or 1
In one aspect of the invention, the application unit is a nozzle unit in which a plurality of nozzles for spraying the barrier liquid are arranged.

The invention of claim 17 is the invention of claims 9 to 16
The invention according to any one of the above, wherein a material containing a compound having a polysiloxane skeleton is used as the barrier liquid.

The invention of claim 18 is the invention of claims 9 to 16
Any one of the inventions described above, wherein a fluorine-based oil is used as the barrier liquid.

The nineteenth aspect of the present invention provides the ninth to eighteenth aspects.
In any one of the inventions described above, as the printing plate requiring no fountain solution, a printing plate containing a member having a property of reducing a receding contact angle when heated in contact with a liquid is used. is there.

The twentieth aspect of the present invention provides the ninth to nineteenth aspects.
Any one of the inventions described above, wherein a printing plate containing a polymer member having a polysiloxane skeleton is used as the printing plate requiring no dampening solution.

The invention of claim 21 is the invention of claims 9 to 20
In any one of the inventions described above, detecting means for detecting a background density of a printed matter printed using the printing plate, and an application amount of the barrier liquid to the inking roller according to a detection result by the detecting means. Control means.

According to a twenty-second aspect of the present invention, there is provided a printing method in which ink is deposited on a printing plate that does not require dampening solution using an inking roller, and printing is performed on a printing medium using the printing plate with the ink deposited thereon. Using a liquid that is not compatible with the resin or solvent contained in the ink as a barrier liquid, and further supplying a layer of the barrier liquid or dispersed particles of the barrier liquid to the surface of an ink layer formed on the inking roller. In this state, the ink is applied to the printing plate.

According to a twenty-third aspect, in the twenty-second aspect, an ink to which the barrier liquid is added in advance is used as the ink.

According to a twenty-fourth aspect, in the twenty-third aspect, a material containing a compound having a polysiloxane skeleton is used as the barrier liquid.

In a twenty-fifth aspect of the present invention, in the twenty-fourth aspect, the barrier liquid is dimethylpolysiloxane, and the barrier liquid has a viscosity of 30 CS to 100 CS.

According to a twenty-sixth aspect, in the twenty-seventh aspect, the amount of the barrier liquid added to the ink is 0.1.
It is characterized by being in the range of 5 wt% to 3 wt%.

In a twenty-seventh aspect, in the twenty-third aspect, a fluorine-based oil is used as the barrier liquid.

The invention according to claim 28 is the invention according to claims 22 to 2.
The invention according to any one of the seventh to eighth aspects, wherein the background density of the printed matter is detected, and the supply amount of the barrier liquid is controlled according to the detected value.

[0033] The invention of claim 29 is the invention of claims 22 to 2
8. The printing plate according to any one of items 8, wherein the printing plate that does not require dampening solution is a printing plate containing a member having a property of reducing a receding contact angle when heated in contact with a liquid. is there.

The invention of claim 30 is the invention of claims 22 to 2
8. The printing plate according to any one of items 8, wherein a printing plate containing a polymer member having a polysiloxane skeleton is used as the printing plate requiring no fountain solution.

[0035]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a printing plate that does not require dampening solution,
It is applicable to a printing apparatus having an inking roller for depositing a resin and an ink containing a solvent of the resin on the fountain solution unnecessary plate, the surface of the ink layer placed on the inking roller, Alternatively, a liquid that is not compatible with the resin or solvent of the ink (hereinafter, referred to as a liquid near the surface of the ink layer)
(Hereinafter referred to as "barrier liquid") or in a state in which dispersed particles are arranged.

When a liquid layer that is not compatible with the ink resin or the solvent is formed on the ink surface or the plate surface,
Because the liquid acts as a barrier between the plate and the ink,
Background dirt can be prevented. In the method of forming a liquid layer on the plate surface, the material of the plate is limited because the plate material is required to have a liquid retaining property for forming the liquid layer,
Further, various types of printing plates cannot be used as a printing device. Therefore, the present invention is characterized in that printing is performed in a state in which a liquid that is not compatible with the ink resin or the solvent is formed on the surface of the ink layer on the inking roller.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings for describing the embodiments, portions having similar functions are denoted by the same reference numerals, and repeated description thereof will be omitted. Figure 1
FIG. 1 is a schematic configuration diagram for explaining the principle of preventing background contamination according to the present invention. FIG. 1 shows an example in which a layer of a barrier liquid 12 is formed on the surface of a layer of ink 11 formed on an inking roller 10. 1A shows an example in which particles of the barrier liquid 12 are dispersed and arranged in the vicinity of the surface of the ink 11 layer.
This is shown in FIG. First, as shown in FIG. 1A, when a layer of the barrier liquid 12 is formed on the surface of the ink 11, the barrier liquid 12 exists between the ink 11 and the plate 20. The stain on the surface of the plate 20 can be prevented.

However, if the effect of the barrier liquid 12 is too strong, the ink may be repelled even in an image portion at the time of printing, resulting in poor ink deposition. Therefore, FIG.
As shown in FIG. 3B, dispersing the barrier liquid 12 in the form of particles on the surface of the ink layer 11 makes it possible to achieve both prevention of background contamination of the printing plate 20 and stability of ink deposition on the printing plate 20.

As shown in FIG. 1A, when a layer of the barrier liquid 12 is formed on the layer surface of the ink 11,
If the thickness of the second layer is extremely thin, both the above-mentioned inking property and prevention of background contamination can be achieved. In that case, the layer thickness of the barrier liquid 12 is suitably about 0.1 μm to 2 μm. Further, as shown in FIG.
In the case where the particles are dispersed in the form of particles, the particle diameter is 0.1 μm.
m to about 10 μm is preferable. When the particle size is smaller than 0.1 μm, the effect as a barrier layer is small, and when the particle size is larger than 10 μm, blurring occurs in a solid image portion.

Examples of the material of the printing plate that does not require dampening water include a so-called silicone resin or silicone rubber having a polyorganosiloxane as a basic skeleton, a fluororesin having a perfluoroalkyl group, or polyethylene or polypropylene having an alkyl group. Suitable.

The composition of the ink 11 includes resins such as rosin-modified phenolic resins and alkyd resins, petroleum-based high-boiling solvents, vegetable oils containing saturated or unsaturated fatty acids,
And an ink containing a pigment, and a viscous ink having an ink viscosity in the range of 10 Pa · s to 500 Pa · s is suitable.

FIG. 2 is a schematic configuration diagram for explaining an example of the configuration of an inking roller unit to which the present invention can be applied. Inking roller unit 30
FIG. 2A shows a configuration in which a plurality of rollers are combined to supply the ink supplied from the ink stopper 31 to the plate 20 while kneading between the rollers.
As shown in (B), a configuration in which the ink is supplied to the plate 20 while controlling the ink thickness by the ink scraping blade 32 is appropriate. Such an inking roller is provided with a barrier liquid application unit according to the present invention described below.

FIG. 3 is a schematic configuration diagram for explaining a configuration example of a printing apparatus to which the present invention can be applied. As shown in FIG. 3A, an offset printing configuration having an offset blanket copper 21 as shown in FIG. Alternatively, it is appropriate to adopt a direct printing configuration in which the ink of the plate 20 is directly transferred to paper as shown in FIG. In FIG. 3, 2
Reference numeral 2 denotes a pressure copper, and reference numeral 40 denotes a printing device.

The barrier liquid 12 needs to have a property that does not show compatibility with the resin contained in the ink. The reason is that when the barrier liquid shows compatibility with the resin of the ink, the layer of the barrier liquid 12 is hardly formed on the surface of the layer of the ink 11 on the inking roller 10 or the particles of the barrier liquid 12 are dispersed. This is because, even if these barrier liquid layers and dispersed particles are formed, they are mixed with the resin, and the barrier effect becomes extremely weak. As a specific liquid agent of the barrier liquid 12, a chemically inert liquid is ideal, and a silicone-based oil or a fluorine-based oil is suitable.

As shown in FIGS. 1A and 1B, a layer of the barrier liquid 12 is simply placed on the inking roller 10 as shown in FIG.
The means for forming the barrier liquid 12 reliably is a means for applying the barrier liquid 12 to the inking roller 10. Also, barrier liquid 1
Since the amount of the barrier liquid 12 on the layer surface of the ink 11 can be controlled by controlling the application amount of the ink 2, the optimal barrier liquid can be controlled according to the change in the environmental temperature in the printing apparatus and the viscosity, color, and type of the ink. The quantity can be chosen.

As another method for creating a state in which a layer of the barrier liquid is formed, in addition to the method of coating the barrier liquid on the roller from the outside as described above, a method in which the barrier liquid is added to the ink in advance and selected. Alternatively, a method of forming a barrier liquid layer on the surface of the ink layer can be employed.

The barrier liquid may be added at the stage of producing the ink, or may be added after the ink is prepared. Also,
In the printing apparatus, it may be added to the ink reservoir. As a problem of the prior art, when added at the ink manufacturing stage, there is a problem of storage stability depending on the type of the barrier liquid. Therefore, it is preferable to adopt a method of adding the ink in the ink reservoir of the printing apparatus.

The means for applying the barrier liquid to the inking roller 10 is preferably provided on the inking roller 10 in contact with the plate. When the application unit is configured as an inking roller unit 30 including a plurality of inking rollers, it is basically effective to arrange the inking roller on any of the inking rollers. When the application means is arranged,
When soil contamination occurs due to changes in conditions such as environmental conditions,
Since the response time for controlling the barrier liquid layer can be shortened, the control is facilitated.

As a means for applying the barrier liquid to the inking roller, an application roller for applying the barrier liquid 11 can be used. A method in which a roller having a thin layer of the barrier liquid 11 formed on the surface thereof in contact with the inking roller as an application means has an advantage in that even a slightly viscous barrier liquid can be handled. In addition, there is an advantage that the barrier roller is excellent in uniform application properties in the axial direction of the application roller. FIG. 4 shows a specific example.

FIG. 4A shows a method of forming a layer of the barrier liquid 12 on the application roller 50 in advance by using a flexible porous elastic body 51 impregnated with the barrier liquid 12.
FIG. FIG. 4 (B)
Shows a configuration in which the application roller 52 itself is an elastic porous body impregnated with the barrier liquid 12. Of course, the supply of the barrier liquid to the application roller 50 is not limited to the above-mentioned porous elastic body, and any known means can be used as appropriate.

As a means for applying the barrier liquid to the inking roller, means in which a plurality of nozzles for spraying the barrier liquid can be used. As described above, the configuration in which the barrier liquid is applied using the application roller requires another mechanism for forming a thin layer of the barrier liquid on the application roller, and the apparatus becomes complicated. Therefore, the simplest mechanism is a mechanism for spraying finely divided barrier liquid onto the inking roller by a nozzle for spraying the barrier liquid. However, in order to atomize the barrier liquid, it is necessary that the viscosity of the barrier liquid is low to some extent, and a suitable viscosity is 1 CS to 50 CS.

FIG. 5 is a schematic configuration diagram for explaining the configuration of a nozzle for spraying the above barrier liquid. FIG.
As shown in (A), the barrier liquid 12 is sprayed by using the nozzle 53 at a distance from the surface of the inking roller 10. If the distance is longer than necessary, the barrier liquid 12 may adhere to the surface of the plate 20. Therefore, it is preferable that the distance is close to some extent, and the distance is appropriately set to 10 mm to 100 mm. As shown in FIG. 5B, the nozzles as described above include a configuration in which a plurality of individual nozzles 53n are arranged, or a nozzle hole 5n as shown in FIG.
The barrier liquid may be sprayed from this nozzle hole using a member provided with a plurality of 3o. Barrier liquid 1
The direction of spraying 2 may be from above or below the inking roller 10.

Next, a preferred composition of the barrier liquid will be described. As a result of various studies by the present inventors, it has been found that a material having a polysiloxane skeleton represented by the following chemical formula (1) has a remarkable effect as a barrier liquid. Further, in addition to the material having the structure of the following chemical formula (1), a modified type thereof, for example, a material such as fluorine-modified, amino-modified, epoxy-modified, alkyl-modified, polyether-modified, phenol-modified, or alcohol-modified may be used. .

[0054]

(Equation 1)

As a specific example of the material having a polysiloxane skeleton, dimethylpolysiloxane can be given. The suitable viscosity of the dimethylpolysiloxane at this time is in the range of 30 CS to 100 CS. The present inventors have conducted various experiments on the viscosity of dimethylpolysiloxane and found that a viscosity range of 30 CS to 100 CS is most effective in preventing background fouling. Although the reason is not clear, it is considered that if the viscosity is too high, it is difficult to form a barrier liquid selectively on the surface of the ink layer, and if the viscosity is too low, the compatibility with the ink resin is considered to be related.

Good results can be obtained by adjusting the amount of the barrier liquid made of dimethylpolysiloxane to 0.5 wt% to 3 wt%. The present inventors have conducted various experiments on the addition amount of dimethylpolysiloxane, and found that the addition range of 0.5 wt% to 3 wt% is most effective in preventing background fouling. It is considered that when the addition amount is large, the barrier layer on the surface of the ink layer becomes thicker, the barrier effect on the ink between the rollers becomes stronger, and the ink does not transfer between the rollers.

As another example of the barrier liquid, a fluorine-based oil can be suitably used. As a result of various studies by the present inventors, the following chemical formulas (2) and (3) were used as barrier liquids.
It was found that fluorine oil as in (4) had a remarkable effect. It is preferable that the fluorine oil and the solvent in the ink have no compatibility.

[0058]

(Equation 2)

An embodiment in which the background density of the printed matter is detected and the amount of the barrier liquid added is controlled in accordance with the numerical value will be described. FIG. 6 is a diagram for explaining a configuration in which background contamination is detected and the amount of barrier liquid is controlled. The degree of background contamination changes according to the amount of the barrier liquid added to the ink layer on the inking roller 10. Therefore, as shown in FIG. 6, background stain on the plate or paper is detected by the optical density sensor 61, and the background stain density calculation circuit 62 calculates the background stain density.
The control amount of the barrier liquid is calculated by the barrier liquid detection line calculation circuit 63, and the operation of the compression pump 65 is controlled by the barrier liquid amount control circuit 64 to control the barrier liquid amount. The barrier liquid extruded from the compression pump 65 is supplied to the spray coater 54.
Erupts from That is, the amount of barrier liquid supplied to the roller is controlled in accordance with the degree of background soiling of the plate. As the background stain detecting means, an optical density sensor which detects the optical density of the background portion on the plate or paper by the light reflection intensity as described above is appropriate.

Next, the characteristics of the plate will be described. Good results can be obtained by using a plate containing a member having the property of reducing the receding contact angle when heated in contact with a liquid, as a plate not requiring dampening water. The plate material used is disclosed in JP-A-3-17.
The fluororesin described in No. 8478 is suitable. The plate making method may be a method in which the entire surface of the plate is heated in advance in contact with the liquid and the background portion is heated in accordance with the image signal, or a method in which only the image portion is heated in contact with the liquid in accordance with the image signal.

As another example of a plate that does not require a fountain solution, it is preferable to use a plate containing a polymer member having a polysiloxane skeleton. The polymer member having a polysiloxane skeleton may be either a photosensitive silicone resin or a thermosetting silicone resin. As a plate making method, a method of forming by photo-exposure using a photosensitive silicone resin and using an under-film as a mask or an ablation method of destroying the silicone resin by laser can be used.

FIG. 7 is a flowchart for explaining a printing method according to the present invention using the functions as described above. As described above, the function of the present invention is to provide a printing technique using an inking roller for depositing ink on a printing plate that does not require dampening solution. A barrier liquid that does not exhibit solubility is supplied, and ink is deposited on the printing plate from the inking rotor in that state. In FIG. 7, first, a barrier liquid is prepared (step S1), the barrier liquid is supplied to the ink layer on the inking roller (step S2), and the ink is applied to the printing plate from the inking roller (step S1).
3) In this state, the ink is transferred from the printing plate to the printing medium (step S4). In this flowchart, the flow of the supply of the barrier liquid is represented in time series, but in actual printing, the above-described steps S1 to S1 are performed.
In step 4, the processing is performed simultaneously and in parallel while performing the above steps.

(Example 1) Plate: Fluorine-containing acrylate polymer Ink: Commercially available waterless lithographic ink (viscosity 100 Pa.
S) Printing equipment: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
Viscosity 30CS) Barrier liquid forming means: A roller in which the above barrier liquid is formed in advance on a urethane roller is used as a barrier liquid applying means,
This was brought into contact with the first inking roller to transfer the barrier liquid onto the ink.

Table 1 shows the results of the implementation. As shown in Table 1, at a high temperature, the barrier liquid has an effect of preventing background contamination.

[0065]

[Table 1]

(Example 2) Plate: Silicone resin plate Ink: Commercial waterless lithographic ink (viscosity 150 Pa.
S) Printing equipment: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
(Viscosity 100 CS) Barrier liquid forming means: A roller in which the above barrier liquid was previously formed on a urethane roller was used as a barrier liquid application hand, and this was brought into contact with a first inking roller to transfer the barrier liquid onto the ink. .

Table 2 shows the results of the implementation. As shown in Table 2, at a high temperature, the barrier liquid has an effect of preventing background contamination.

[0068]

[Table 2]

Example 3 Plate: Fluorine-containing acrylate polymer Ink: Commercially available waterless lithographic ink (viscosity of 120 Pa ·
S) Printing equipment: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
Viscosity 50CS) Barrier liquid forming means: A porous urethane elastic roller impregnated with a barrier liquid is used as a barrier liquid applying means,
This was brought into contact with the first inking roller to transfer the barrier liquid onto the ink.

Table 3 shows the results of the operation. As shown in Table 3, at a high temperature, the barrier liquid has an effect of preventing background contamination.

[0071]

[Table 3]

(Example 4) Plate: Fluorine-containing acrylate polymer Ink: Commercially available lithographic ink without water (viscosity: 80 Pa · S) Printing equipment: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
(Viscosity: 30 CS) Barrier liquid forming means: An array of spray nozzles was used as a barrier liquid applying means, and the barrier liquid was sprayed onto the mist from the nozzle onto the first inking roller.

Table 4 shows the results of the implementation. As shown in Table 4, at a high temperature, the barrier liquid has an effect of preventing background contamination.

[0074]

[Table 4]

(Example 5) Plate: Fluorine-containing acrylate polymer Ink: Commercially available lithographic ink without water Printing equipment: Commercial offset printing machine Barrier liquid: Fluorine oil (Daikin Industries Demnum) Barrier liquid forming means: On urethane roller A roller on which the barrier liquid was previously formed was used as a barrier liquid application hand, and this was brought into contact with the first inking roller to transfer the barrier liquid onto the ink.

Table 5 shows the results of the implementation. As shown in Table 5, at a high temperature, the effect of preventing the background stain of the barrier liquid is obtained.

[0077]

[Table 5]

(Example 6) Plate: Fluorine-containing acrylate polymer Ink: Commercially available lithographic ink without water Printing equipment: Commercial offset printing machine Barrier liquid: Fluorine oil (Daikin Industries) Means for forming barrier liquid: Urethane roller described above A roller on which a barrier liquid was previously formed was used as a barrier liquid application hand, and this was brought into contact with a first inking roller to transfer the barrier liquid onto the ink.

Table 6 shows the results of the operation. As shown in Table 6, the barrier liquid has an effect of preventing background contamination at high temperatures.

[0080]

[Table 6]

(Example 7) Plate: Fluorine-containing acrylate polymer Ink: Commercially available lithographic ink without water Printing equipment: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-9)
6). Means for forming barrier liquid: Immediately before printing, the barrier liquid was added to a commercially available ink at about 2 wt% and stirred.

Table 7 shows the results of the implementation. As shown in Table 7, at a high temperature, the barrier liquid has an effect of preventing background contamination.

[0083]

[Table 7]

Example 8 Plate: Fluorine-containing acrylate-based polymer Ink: Commercially available lithographic ink without water Printing equipment: Commercial offset printing press Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
(Viscosity: 10 CS to 1000 CS) Barrier liquid forming means: The above barrier liquid was added to a commercially available ink and stirred immediately before printing.

Table 8 shows the results of the implementation. As shown in Table 8, at a viscosity of 30 to 100 CS, the effect of preventing the soiling of the barrier liquid is exhibited.

[0086]

[Table 8]

(Example 9) Plate: Fluorine-containing acrylate polymer Ink: Commercially available lithographic ink without water Printing equipment: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
(Viscosity: 100 CS) Barrier liquid forming means: The above barrier liquid was added to a commercially available ink and stirred immediately before printing. The amount added at this time is 0 wt%
From 4 wt%.

Table 9 shows the results of the implementation. As shown in the table, the effect of preventing the soiling of the barrier liquid is obtained when the addition amount is 1 wt% to 2 wt%.

[0089]

[Table 9]

Example 10 Plate: Fluorine-containing acrylate polymer Ink: Commercially available lithographic ink without water Printing equipment: Commercial offset printing machine Barrier liquid: Various modified silicone oils Barrier liquid forming means: Immediately before printing the above barrier liquid It was added to a commercially available ink and stirred.

Table 10 shows the results of the implementation. As shown in Table 10, dimethylsiloxane has an effect of preventing the background of the barrier liquid.

[0092]

[Table 10]

(Example 11) Plate: Fluorine-containing acrylate polymer Ink: Commercially available waterless lithographic ink Printing device: Commercial offset printing machine Barrier liquid: dimethylsiloxane (Shin-Etsu Chemical KF-96,
(Viscosity 100 CS) Barrier liquid forming means: A roller in which the above barrier liquid was previously formed on a urethane roller was used as a barrier liquid application hand, and this was brought into contact with a first inking roller to transfer the barrier liquid onto the ink. . Means for detecting background stain: A white light source for detecting the background density of paper by reflected light and a photodiode for detecting reflected light are arranged at the paper discharge portion.

As a result, in continuous printing, by automatically increasing the amount of the barrier liquid applied in accordance with the rise in the plate surface temperature, it was possible to prevent background contamination due to the temperature rise without cooling the plate surface.

[0095]

According to the invention of claims 1, 9 and 22,
By forming a barrier liquid layer or barrier liquid dispersed particles on the surface of the ink layer formed on the inking roller. It is possible to effectively prevent soiling due to a change in environmental temperature without providing a large-scale cooling device as in the related art.

According to the second aspect of the present invention, since the coating unit is provided on the inking roller which is in contact with the printing plate, the responsiveness of the prevention control at the time of occurrence of background contamination is the best and the control stability is improved. Can be higher.

According to the third and twelfth aspects of the present invention, the barrier liquid layer formed on the roller or the barrier liquid held by the roller is transferred to the inking roller to apply the barrier liquid to the inking roller. By doing so, the most uniform coating is obtained, and printing with high reliability is possible.

According to the fourth and thirteenth aspects of the present invention, the reliability can be improved by using a silicone resin for the roller for applying the barrier liquid.

According to the fifth and fourteenth aspects of the present invention, the barrier liquid is impregnated into the porous elastic body which can be brought into contact with the roller to which the barrier liquid is applied, and the porous elastic body is brought into contact with the roller. By forming the barrier liquid layer on the roller surface, the barrier liquid can be supplied onto the roller with a simple configuration.

According to the sixth and fifteenth aspects of the present invention, the coating roller is formed of a porous elastic body, and the porous elastic body is impregnated with a barrier liquid. Barrier liquid can be supplied.

According to the seventh and sixteenth aspects of the present invention, a barrier unit is sprayed with a nozzle unit having a plurality of nozzles arranged side by side, so that the coating apparatus can be simplified most. It can be easily mounted on the vehicle.

According to the invention of claims 8, 21 and 28,
By detecting the background density of the printed matter printed using the printing plate and controlling the amount of barrier liquid applied to the inking roller according to the detection result, it is possible to flexibly respond to changes in environmental conditions , Reliability is improved.

According to the tenth aspect of the present invention, by using the application means for applying the barrier liquid to the inking roller, it is possible to reliably and easily prevent background contamination using a general-purpose ink and plate.

According to the eleventh aspect of the present invention, by providing the coating means on the inking roller which is in contact with the printing plate, the responsiveness of prevention control at the time of occurrence of background contamination is the highest, and high control stability can be obtained. .

According to the seventeenth and twenty-fourth aspects of the present invention, by using a material containing a compound having a polysiloxane skeleton as the barrier liquid, a high effect is exhibited in the barrier liquid, so that the reliability can be improved.

According to the inventions of claims 18 and 27, by using a fluorine-based oil as the barrier liquid, a high effect is exhibited in the barrier liquid, so that the reliability can be improved.

According to the nineteenth and twenty-ninth aspects of the present invention, as a printing plate requiring no dampening solution, a printing plate containing a member having a property of reducing a receding contact angle when heated in contact with a liquid is used. Image quality obtained by printing can be improved.

According to the twentieth and thirty aspects of the present invention, by using a plate containing a polymer member having a polysiloxane skeleton as a printing plate requiring no fountain solution, image quality obtained by printing can be improved. .

According to the twenty-third aspect of the present invention, by using an ink to which a barrier liquid is added in advance, it is possible to prevent background contamination without improving a commercially available printing press.

According to the twenty-fifth aspect, the barrier liquid is dimethylpolysiloxane, and the barrier liquid has a viscosity of 3%.
By changing from 0CS to 100CS, a viscosity range in which the background fouling eliminating effect is most provided is provided, and reliability can be improved.

According to the twenty-sixth aspect of the present invention, by setting the amount of the barrier liquid to be added to the ink in the range of 0.5 wt% to 3 wt%, the range of the amount of addition that is most effective in eliminating background contamination is provided. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining a principle of background dirt prevention according to the present invention.

FIG. 2 is a schematic configuration diagram for describing a configuration example of an inking roller unit to which the present invention can be applied.

FIG. 3 is a schematic configuration diagram for explaining a configuration example of a printing apparatus to which the present invention can be applied.

FIG. 4 is a diagram for explaining an advantage of a barrier liquid.

FIG. 5 is a schematic configuration diagram for explaining a configuration of a nozzle for spraying a barrier liquid.

FIG. 6 is a diagram for describing an embodiment in which background contamination is detected and the amount of barrier liquid is controlled.

FIG. 7 is a flowchart illustrating a printing method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Inking roller, 11 ... Ink, 12 ... Barrier liquid, 20 ... Plate (printing plate), 21 ... Offset blanket copper, 22 ... Pressed copper, 30 ... Inking roller unit,
31: ink retaining, 32: ink scraping blade, 4
0: printing device, 50: coating roller, 51: porous elastic body, 52: coating roller, 53: nozzle, 53n: individual nozzle, 53o: nozzle hole, 54: spray coater, 61
... Optical density sensor, 62...
Reference numeral 3 represents a background dirt / barrier liquid detection line calculation circuit, 64 represents a barrier liquid amount control circuit, and 65 represents a compression pump.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) B41N 1/14 B41N 1/14 F term (reference) 2C034 AA09 AA12 2C250 DB29 DC05 EA21 EB50 2H113 AA01 AA05 BA06 BA07 BB02 BB22 BC02 DA49 DA64 EA10 EA12 FA51 2H114 AA05 AA06 AA22 AA23 AA24 BA02 BA06 DA49 DA62 EA04 4F040 AA02 AB20 AC01 BA16 CB40

Claims (30)

[Claims] 1. An application unit for applying a barrier liquid that is not compatible with a resin or a solvent contained in an ink to an inking roller for depositing the ink on a printing plate requiring no dampening solution. The coating unit, wherein a layer of the barrier liquid or dispersed particles of the barrier liquid can be formed on the surface of the ink layer formed on the inking roller by the coating unit. 2. The coating unit according to claim 1, wherein the coating unit is provided on an inking roller that is in contact with the printing plate. 3. The coating unit according to claim 1, wherein the coating unit has a roller capable of forming a layer of the barrier liquid on a surface thereof, and the barrier liquid layer formed on the roller or the roller is formed on the roller. An application unit, wherein the barrier liquid is applied to the inking roller by transferring the held barrier liquid to the inking roller. 4. The ink application unit according to claim 3, wherein the roller has a surface material using a silicone resin. 5. The coating unit according to claim 2, wherein the coating unit has a porous elastic body capable of contacting the roller, and impregnating the porous elastic body with a barrier liquid. An application unit, wherein the barrier liquid layer is formed on the surface of the roller by bringing a porous elastic body into contact with the roller. 6. The coating unit according to claim 2, wherein the coating roller is formed of a porous elastic material, and the roller is formed by impregnating the porous elastic material with the barrier liquid. A coating unit characterized in that it can hold a barrier liquid. 7. The coating unit according to claim 1, wherein the coating unit includes a nozzle unit in which a plurality of nozzles for spraying the barrier liquid are arranged. 8. The coating unit according to claim 1, wherein the detection unit detects a background density of a printed material printed using the printing plate, and the detection unit detects a background density of the printed material. Means for controlling the amount of application of the barrier liquid. 9. A printing apparatus having at least a printing plate requiring no dampening solution and an inking roller for depositing ink on the printing plate, does not exhibit compatibility with the resin or solvent contained in the ink. Using a liquid as a barrier liquid, it is possible to deposit ink on the printing plate in a state in which a layer of the barrier liquid or dispersed particles of the barrier liquid is further supplied to the surface of the ink layer formed on the inking roller. And a barrier liquid layer forming means. 10. The printing apparatus according to claim 9, wherein
The printing apparatus according to claim 1, wherein the barrier liquid layer forming unit is a coating unit that applies the barrier liquid to the inking roller. 11. The printing apparatus according to claim 10, wherein the application unit is provided on an inking roller that is in contact with the printing plate. 12. The printing apparatus according to claim 10, wherein the coating unit is a roller capable of forming a layer of the barrier liquid on a surface thereof, wherein the barrier liquid layer formed on the roller or the roller is A printing apparatus, wherein the barrier liquid is applied to the inking roller by transferring the held barrier liquid to the inking roller. 13. The printing apparatus according to claim 12, wherein the roller has a surface material using a silicone resin. 14. The printing apparatus according to claim 12, wherein the coating unit has a porous elastic body that can contact the roller, and impregnates the porous elastic body with a barrier liquid. A printing apparatus, wherein the barrier liquid layer is formed on a surface of the roller by bringing a porous elastic body into contact with the roller. 15. The printing apparatus according to claim 12, wherein the coating roller is formed of a porous elastic body, and the roller is formed by impregnating the porous elastic body with the barrier liquid. A printing apparatus characterized in that it can hold a barrier liquid. 16. The printing apparatus according to claim 10, wherein the application unit is a nozzle unit in which a plurality of nozzles for spraying the barrier liquid are arranged. 17. The printing apparatus according to claim 9, wherein a material containing a compound having a polysiloxane skeleton is used as the barrier liquid. 18. The printing apparatus according to claim 9, wherein a fluorine-based oil is used as the barrier liquid. 19. The printing apparatus according to claim 9, wherein the printing plate that does not require dampening solution has a property that a receding contact angle decreases when heated in contact with a liquid. A printing apparatus characterized by using a plate containing the printing plate. 20. The printing apparatus according to claim 9, wherein a printing plate containing a polymer member having a polysiloxane skeleton is used as the printing plate requiring no dampening solution. Printing device. 21. A printing apparatus according to claim 9, wherein said printing means is configured to detect a background density of a printed matter printed by using said printing plate, and the detection means detects a background density of the printed matter. Means for controlling the amount of the barrier liquid applied to the inking roller. 22. A printing method in which an ink is applied to a printing plate that does not require dampening water using an inking roller, and printing is performed on a printing medium by using the printing plate provided with the ink. Using a liquid that does not show compatibility with the resin or solvent to be used as a barrier liquid, and further supplying a layer of the barrier liquid or dispersed particles of the barrier liquid to the surface of an ink layer formed on the inking roller, A printing method comprising depositing ink on a printing plate. 23. A printing method according to claim 22, wherein said ink is an ink to which said barrier liquid is added in advance. 24. The printing method according to claim 23, wherein a material containing a compound having a polysiloxane skeleton is used as the barrier liquid. 25. The printing method according to claim 24, wherein the barrier liquid is dimethylpolysiloxane,
A printing method, wherein the viscosity of the barrier liquid is from 30 CS to 100 CS. 26. The printing method according to claim 25, wherein the amount of the barrier liquid added to the ink is 0.5 w.
A printing method characterized by being in the range of t% to 3% by weight. 27. The printing method according to claim 23, wherein a fluorine-based oil is used as the barrier liquid. 28. The printing method according to claim 22, wherein a background density of the printed matter is detected,
A printing method comprising controlling the supply amount of the barrier liquid according to the numerical value. 29. The printing method according to claim 22, wherein the printing plate that does not require dampening solution has a property that the receding contact angle decreases when heated in contact with a liquid. A printing method characterized by using a contained plate. 30. The printing method according to claim 22, wherein a printing plate containing a polymer member having a polysiloxane skeleton is used as the printing plate requiring no dampening solution. Method.