JPH02245374A - Printing, and printing plate, blanket - Google Patents

Abstract

PURPOSE:To make possible accurate pattern printing by making ink magnetic and changing a magnetic field non-selectively and transferring the ink when the ink on the surface of a printing plate is transferred to a material to be printed on. CONSTITUTION:The ink 13 used is of photosensitive resin containing magnetic fine powder. The material to be printed is given ink 13 from an ink nozzle 14 on the top of a plate cylinder 11 in a non-magnetized area A where glass 18, on the entire surface of which an indiumtin oxide is sputtered is placed on a mobile table 19. Then all the ink excepting the one in a recessed part 20 is scraped off by a doctor 15. A coil 12 is magnetized non-selectively in the axial direction of the plate cylinder 11 in a magnetized area B right before the bottom after the ink 13 is scraped off. The ink 13 in the recessed part 20 is attracted by the coil to run around to the bottom of the plate cylinder 11. The ink 13 around the bottom is magnetized slightly in a reversed direction to the magnetized area B, in a weak, inversely magnetized area C. Consequently, the ink separates from the plate cylinder 11, moving to the glass 18 side.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention is generally applicable to intaglio, gravure, electrostatic gravure, offset gravure, direct printing planography, offset planography, letterpress, etc. photoresists, pigments, dye base materials, The present invention relates to a printing method for applying a pattern to a printing material such as paper, resin, glass, ceramic, resin, IC, etc. using various inks such as ordinary printing ink, and a plate and a plankent used therein.

<Conventional technology> The conventional technology will be briefly explained.

In conventional printing methods such as intaglio printing, lithographic printing, and letterpress printing, in which ink is patterned on the plate surface, when ink is transferred from the plate or blanket to the printing material, it is difficult to transfer the ink from the plate or blanket to paper, resin, glass, etc. Pressure was applied between the paper and the printing material to transfer the ink.

<Problems to be Solved by the Invention> However, when pressure is applied between the printing medium and the plate or blanket during ink transfer, the physical resistance of the plate, blanket, or printing medium becomes a problem. In addition, the pressure causes the plate, blanket, and printing material to become distorted and deformed, resulting in a problem that printing accuracy is reduced.

In addition, plates and blankets need to have a certain degree of ink affinity and ink phobicity. In other words, in the case of a plate, if there is no ink affinity, the ink will fall off the plate due to gravity etc. before it is transferred to the printing material or blanket, or if the ink has too high an affinity for the ink. Then, when the ink is transferred to the blanket or printing material, even if the ink is in contact with it, no transfer occurs. In the case of blankets, it is even more serious; if there is no ink affinity, the ink will not only fall off the plate due to gravity, but also fall from the plate to the blanket. If the affinity for the ink is too high, the transfer will no longer occur even if the ink is in contact with the printing material. Therefore, since both the conditions of ink affinity with the plate cylinder and ink phobicity with the printing medium must be satisfied, it may be difficult to set the conditions. It is particularly difficult to use materials such as glass, which have high ink phobicity and low physical resistance.

Furthermore, the tank required for ink during printing is limited from the perspective of preventing trapping, and in many cases the above problems cannot be solved by ink characteristics alone.

Note that, as a method of promoting ink transfer, there is a method such as electrostatic gravure in which a charge is applied to the ink to assist the ink transfer, but even if such a method is used, complete transfer is difficult.

In addition, as an ink holding means, for example, Japanese Patent Application Laid-open No. 52'
-13912, JP-A-56-93587, JP-A-5
7-70689, etc., the entire surface of the plate is coated with toner, and ink (toner) is applied to each dot using electromagnetic control or thermal control.
There is a way to control whether or not it is transferred. but,
This method requires control in both directions of the negative dimension, and increasing the don't accuracy is technically difficult due to the design technology of the magnetic field and heat arrangement due to leakage magnetic fields and heat radiation.

Also, if the ink is not a dry ink, adjacent dots will be pulled together. It is difficult to control, and there are technical bottlenecks in improving accumulation. Moreover, controlling the film thickness is quite difficult.

In addition, as a method of partially transferring ink by applying a magnetic field to the entire screen, as in Japanese Patent Application Laid-Open No. 57-29588, ink is sequentially supplied to the entire screen or linearly, and the ink is applied to a patterned screen. There is a stencil printing method in which a magnetic field is applied between a screen and a printing material to transfer ink when a pattern is transferred via a screen. However, with this method, it is not possible to control the ink film thickness, and the screen expands and contracts, making it difficult to perform precise printing.

In order to create a screen that does not expand or contract, it is better to increase the film thickness of the screen, but this makes it difficult to transfer the ink and reduces accuracy. Another drawback is that the printing speed is slow.

Accordingly, there has been a need for a printing method capable of printing even more precise patterns, and for a plate or blanket used therein.

Means for solving Section J> To solve the above problem, it is possible to use magnetic ink and change the magnetic field at the time when the ink on the plate surface is transferred to the printing material or blanket, or to transfer the ink from the blanket to the printing material. This can be solved by using printing means that changes the magnetic field at the point of transition from the plate to the blanket, or changes the magnetic field at the point of transition from the plate to the blanket.

It should be noted that here, whether the plate is a lithographic printing plate or a circular printing plate, whether the blanket is flat or circular, whether the printing method is intaglio printing or planographic printing, letterpress printing is used. It doesn't matter whether it's printing or not.

It should be noted that the printing element used in this means is a non-selective printing element for each specific direction along a direction orthogonal to the specific direction.
Plaques and plankents are available that have electromagnets inside along the surface that can be controlled to apply a different magnetic field, but this element is not essential. The magnetic field is changed non-selectively in the line or width area type.

Note that it does not matter whether the plate or blanket is cylindrical, the specific direction is the frequency division direction, and the direction orthogonal to the specific direction is the axial direction, or the plate or blanket is flat, or has another shape.

Alternatively, a planar plate or blanket may be used which is provided with electromagnets along its surface that can control the application of a non-selective magnetic field to the entire surface. In this case, the magnetic field to be changed at the time of transition is non-selectively changed in the entire area at once.

Note that changing the magnetic field here means changing it so that it applies a magnetic field that was not applied before, changing it by cutting off the magnetic field that was applied before, or changing it by applying a magnetic field that is the opposite of the previous magnetic field. , if we reduce the magnetic field until now,
This is a general term for increasing the existing magnetic field.

Among these, when changing to apply an IF field that has not been applied before, or when increasing the existing magnetic field, it is used as a means from the ink transfer destination side to obtain ink transfer from the ink transfer source side. It will be done.

When changing the magnetic field that has been applied so far or reducing the magnetic field that has been applied so far, it is used as a means from the ink transfer source side to transfer and separate the ink from the ink transfer source side.

Depending on the magnitude of the magnetic field, it can be used to change the current magnetic field by applying a reverse magnetic field, or to reduce the current magnetic field.

When used as a means from the ink transfer destination side to obtain ink transfer from the ink transfer source side, it is common and efficient to change it so that a magnetic field that has not been applied before is applied.

When used as a means from the ink transfer source side to transfer and separate ink from the ink transfer source side, it is more efficient to momentarily apply a weak magnetic field opposite to the previously applied magnetic field and then turn off the magnetic field. Good, and the transfer efficiency is better than the method from transfer light.

However, when applying a magnetic field until the ink on the plate surface is transferred to the printing material or blanket, the time to start applying the magnetic field may be before the ink is applied to the plate, at the same time as the ink is applied, or at the same time as the ink is applied. After that, the ink is patterned, for example, in the case of intaglio printing, unnecessary ink is removed with a doctor or wiper, which may be done before, at the same time, or after, and a magnetic field is generated until the ink on the blanket is just about to be transferred to the printing material. In this case, the application of the magnetic field may be started before the ink is transferred from the plate, at the same time as the transfer, or after the transfer. However, if you are concerned that the ink on the surface of the plate or blanket may fall off due to gravity, it is not necessary to apply a magnetic field while the ink is on the plate or blanket, but the reverse is not true. In both cases, there is a certain degree of inclination or ζ
It is necessary to apply a magnetic field to the part ′. Also,
In the case of intaglio printing, when removing unnecessary ink with a doctor or wiper, if the ink is tightly adhered to the plate due to the magnetic field, the ink that should be removed may not be able to be removed or may be difficult to remove. In this case, it is best not to apply a magnetic field when removing unnecessary ink with a doctor or wiper.

In addition, there are methods to non-selectively change the magnetic field, such as changing the magnetic field all at once, dividing the width into small areas and changing the magnetic field little by little, and then transferring ink to only those areas, and gradually changing the magnetic field in a line. There are methods to transfer ink by changing the magnetic field.

Among these methods, the method of changing the magnetic field of the entire device at once makes it easy to arrange the electromagnets, but it can only be used on flat tables.

The method of dividing the width and changing the magnetic field little by little in an area and transferring ink only to that area is easy to arrange the electromagnets, but the stepping drive makes the drive system complicated and causes pattern misalignment between widths. The method of transferring ink by changing the magnetic field little by little in a linear manner is the most effective method for transferring ink, which tends to cause a drop in pattern accuracy, an increase in contact pressure, and distortion due to contact height differences in the case of cylindrical shapes. Although it is small, it is not easy to place the magnet.

In addition, in the case of transferring ink from the plate or blanket to the printing material, or from the plate to the blanket, the mechanical structure may be different if the transfer destination side is on top of the transfer source side at the time of transfer. This is relatively simple, and in a configuration where the transfer destination side is below the transfer source side, the ink transfer is aided by gravity and is suitable for pressureless printing, and in a configuration where the transfer source and transfer destination are in contact on the side, It is possible to minimize mechanical distortion such as deflection of the transfer source and transfer destination, making it suitable when precision is required. As described above, each positional relationship has advantages and disadvantages, and it is necessary to select the appropriate one according to the situation.

In addition, the installation position of the electromagnet for the magnetic field can be broadly divided into the transfer source side and the transfer destination side, but in the case of the transfer source side, it is necessary to configure it below the surface of the plate or blanket, so it is not practical. The plate is made by forming an electromagnet in advance into a cylindrical or flat plate shape, and then fixing or forming a plate on top of it. However, if it is made in one piece, it is difficult and expensive to make, and it is necessary to add it later. In this case, there are problems in that the distance between the plates tends to be large and it is difficult to control the magnetic field, so there are advantages and disadvantages. On the other hand, when it is configured on the transfer destination side, there is a drawback that the advancement of ink transfer cannot be controlled such as ink retention. If the transfer destination is the printing material, it will be transferred to the printing material itself! Since it is rare that a magnet can be constructed, in most cases, an electromagnet is constructed in the support member of the printing medium. In this case, the electromagnet has the advantage of being easy to incorporate, but it cannot be used when the printing material is thick because it is separated from the ink by the thickness of the printing material.

Note that the i magnets are mainly arranged in a cylindrical shape or a flat plate, but in the case of a flat plate, the configuration is relatively simple and a uniform magnetic field can be applied and controlled over the entire surface 'f:! , a flat plate, a blanket, with magnets inside along its surface;
The support member can be easily produced in either case. However, since this configuration operates the magnetic field uniformly over the entire surface, it can only be used for flat stamps, and the problem is the smoothness of the surfaces of the plate, printing material, support member, etc., so it cannot be applied to all cases. It's not a thing.

There is also a method in which electromagnets are arranged on a support member, the support member and the printing material are configured as flat plates, and the blanket or plate is made into a curved surface such as a cylinder to transfer ink, but in this case, it is not possible to align the blanket or plate. It's not impossible, but it requires considerable skill. On the other hand, if the electromagnet is made into a cylinder, it is naturally more difficult to make it than if it is made from a flat plate, but since the magnetic field ultimately forms a loop, it is necessary to apply the magnetic field to the ink with either the N or S pole. Since the other magnetic field is being applied, it is necessary to send the other magnetic field to the outside world from somewhere. In the case of a flat plate, it is easy because you only need to pour it from the back, but in the case of a cylindrical plate, there are cases where the ink adheres to the area half a circle before the transition area, so there is an idea to pour it from the side. The configuration is complicated and it is not easy to control the magnetic field, so either a configuration in which a reverse magnetic field is applied in the area after the ink has been transferred, or a configuration in which a reverse magnetic field is applied targeting the area where the ink adheres and does not separate. is common.

The plate or blanket in this case does not need to have any affinity for ink; in this case, there will be almost no remaining ink, which will have the effect of preventing trapping, and there will be no need to consider tack.

A method of arranging a large number of electromagnets in parallel at small intervals as described above can be done by winding thin wire, but it is difficult to achieve precision, is expensive to produce, and requires a large number of turns to obtain a large magnetic field. It is difficult to ensure this, and leakage will occur if a large current is applied even though the spacing is narrow.

It is more practical to form sheet coils on the surface because of ease of production, low price, and ease of obtaining precision. However, in order to increase the number of turns, it is necessary to use multiple layers, but this is often difficult in terms of accuracy.

Next, there is also a method of laminating a large number of resin sheets provided with conductive layers in a straight line pattern, cutting them at the ends, and connecting adjacent sets of conductors to create an electromagnet. However, this has problems in that it may not be able to maintain mechanical strength and has low resistance to changes in temperature and humidity.

Next, there is also a method of laminating a large number of insulating layers and conductive layers, cutting them at the ends, and connecting wires between adjacent sets of conductors (JW) to create an amstone. In this case, the number of turns of the coil is equal to the number of wires that are determined by the pattern accuracy of the conductive layer.

In this case, it is necessary to pay attention to the insulating layer's physical strength such as mechanical strength in addition to its insulating performance. For this reason, insulating layers such as permalloy or plate-shaped iron cores are considered to be quite effective.

Furthermore, it may be necessary to use alloy printing instead of mild steel for the electromagnet due to strength issues.

For this reason, if we give up on applying a magnetic field in a line and instead control the magnetic field in units of areas with a certain width, the arrangement of the electromagnets becomes much easier. However, because of the stepping drive, the drive system becomes complicated, and it is necessary to synchronize the stepping motor and electromagnetic control to control the width, which is not easy and may cause pattern misalignment between widths or Due to the difference in contact height in the case of shapes, pattern accuracy is likely to decrease, contact pressure increases, distortion, etc. are likely to occur.

In principle, it is necessary to flow a direct current, but the power source is generally an alternating current power source, and it is necessary to convert it to direct current using an inverter or the like. Recently, transistors with high current resistance have been made, but considering that DC chopper control is required when controlling the magnetic field, Cyrisk control, which allows the DC chopper current to be suddenly changed from AC current, is superior.

Furthermore, the ink that can be used does not matter whether it is dry or wet, but it must have a certain degree of magnetism.

Ordinary ink has almost no magnetism, so it is necessary to add magnetism to it by mixing magnetic powder or other means.However, since it is not a printing method that uses electrostatic force such as electrostatic gravure, the present invention It is considered possible to implement both at the same time. Therefore, a synergistic effect can be expected by implementing them simultaneously.

<Function> When the present invention is used, when the ink on the plate surface is transferred to the printing material or the blanket, the ink on the blanket is transferred to the printing material, or the ink is transferred from the plate to the blanket, the ink transfer is mechanically performed. In addition to pressure, gravity, affinity or electrostatic attraction between the ink and the transfer destination, it is now possible to add another element.

Furthermore, as a printing element for suppressing the above-mentioned effect, it has become possible to provide a plate or a blanket that can control the application of a non-selective magnetic field in an area or line.

<Example> An example in which the magnetic field is line-controlled using a disk intaglio without using the blanket of the present invention will be described in detail with reference to the drawings. Therefore, the present invention is not limited to this embodiment, but also represents embodiments that are replaced by explanations of technologies that can be replaced in the means for solving the problems.

FIG. 1 is a conceptual sectional view of a printing process showing one embodiment of the present invention, and FIG. 2 is an enlarged conceptual sectional view of the same plate cylinder. In addition,
This is an extreme exaggeration because the printing mechanism as a whole and the size of the plates and coils are completely different.

The plate * (11) has a circular shape, and the surface has intaglio recesses (27) patterned by etching or engraving the copper. Below that, there is a coil (indicated by (12) as the coil installation part of the entire coil) in which multiple layers of annealed copper wire and mica are alternately provided, and this plate cylinder (11) An AC-DC chopper control circuit (not shown) is incorporated in the . Further, since this plate cylinder (11) is slightly bent, in order to prevent this, it is supported by stainless steel plate cylinder supports (17) from both sides.

Further, as the ink (13), a mixture of photosensitive resin and magnetic fine powder is used. The printing material is glass (18) on which ITO (indium-tin-oxide) is sputtered all over.
is on a movable platform (19).

F! , the cylinder (11) and the stand (19) recognize the position and rotation angle based on the rotary encoder (not shown) on the side of the plate cylinder and the linear encoder (not shown) on the white side, and synchronize the rotation on the surface. The speeds are controlled to be the same. This data is later synchronized with the magnetic field control TJ of the coil.

Ink (13) is supplied from the ink nozzle (14) on the upper surface of the plate cylinder (11) in the non-applying area (A), and the doctor (1)
5), the ink (13) other than the recess (20) is sniffed out. The scraped ink (13) is placed in the ink pan (16)
and exits from there to the outside of the printing device.

The coil (12) is an application area (B) from after the ink (13) is sniffed to just before the bottom, and may be either N or S, but it applies a magnetic field non-selectively in the axial direction of the plate cylinder (11). multiply. Therefore, the ink (13) in the remaining recess (20)
rotates to the bottom of the plate cylinder (11) while being drawn by the coil (12). It should be noted that the plate cylinder (11) and the glass (1 day) are in contact with each other to such an extent that it is difficult to judge whether they are in contact with each other or not.

Immediately after, the ink (13) that has reached the bottom is applied with a weak magnetic field opposite to the magnetic field applied in the application area (B) in the weak reverse application area (C), and is thereby separated from the plate cylinder (11) and applied to the glass (1).
8) Transfer to the side.

After that, the ink (13) is completely separated from the non-applied page area (
The coil (12) of the plate cylinder (11) in D) immediately cuts off the magnetic field and rotates upward again because the ink does not return.
.

In order to adjust the inflow and outflow of the entire magnetic field from the area where there is no need to worry about reverse transition of ink, the magnetic field is moved in and out in almost one cycle, which is opposite to the magnetic field applied in the application area (8) by the coil (12). are canceled out, and the reverse application area (
form E). This is to prevent magnetic field inequalities in the axial direction of the plate cylinder by freezing the magnetic field coming and going from the side surface of the plate cylinder as much as possible.

In this example, by directly using a rigid plate, it was possible to print accurately on the glass surface, which is easily breakable and to which ink is difficult to transfer, with almost no distortion of the plate.

<Effects of the Invention> The present invention facilitates ink transfer and facilitates pressureless printing and pressure printing. In addition, printing accuracy is improved, and it is possible to compensate for the drawback of unimpressive patterns, which is a particular drawback of pressureless printing and pressure-receiving printing.

In addition, it is possible to avoid to some extent the height error of the convex portion of the printing plate, which is a particular problem in letterpress printing and the like. In addition, it is effective in preventing trapping, allows flexibility in the printing order of ink, and creates the possibility of expressing things that could only be expressed with spot colors in the past. Furthermore, since the ink capture degree is high, it is also effective in preventing misting. It also has the effect of preventing mottling, so it is possible to improve the plate depth in the case of intaglio printing. Furthermore, the range of possible printable viscosities of ink can be expanded, and even ink with poor viscosity can be printed from the upper surface of the printing medium.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual sectional view of a printing process showing an embodiment of the present invention, and FIG. 2 is an enlarged conceptual sectional view of the same plate cylinder. 11... Plate cylinder 12... Coil installation part (coil) 13...
... Ink 14 ... Ink nozzle 15 ... Doctor 16 ... Ink receiver 17 ... Plate cylinder receiver 18 ... Glass I9. .....Base 20 ..... Concavity A ..... Non-applying region B ..... Application region C ..... Weak reverse application H region D ....・・Non-impression area E・・・・・・Reverse voltage area patent Kazuo Suzuki, Representative of Toppan Printing Co., Ltd. Figure 1

Claims (1)

[Claims] 1) In a printing method in which ink applied in a pattern on the surface of a plate is transferred to a printing medium, the ink is magnetic ink, and the ink on the plate surface is transferred to the printing medium. A printing method characterized by non-selectively changing the magnetic field at the point where the ink is transferred. 2) In a printing method in which ink applied in a pattern on the surface of the plate is transferred to the printing material via a blanket, the ink is magnetic ink, and non-magnetic ink is used at the time of transferring the ink on the plate surface to the blanket. A printing method characterized by selectively changing the magnetic field. 3) In a printing method in which ink applied in a pattern on the surface of a plate is transferred to a printing material through a blanket, the ink is magnetic ink, and at the time of transferring the ink on the blanket to the printing material. A printing method characterized by non-selectively changing a magnetic field. 4) Claims 1 and 2, characterized in that the plate is a lithographic printing plate.
, 3. The printing method described in . 5) Claims 1 and 2, characterized in that the plate is a circular printing plate.
, 3. The printing method described in . 6) Claim 2, characterized in that the blanket is flat.
, 3. The printing method described in . 7) Claim 2, characterized in that the blanket is circular.
, 3. The printing method described in . 8) Claims 1, 2, 3, 4, wherein the method of patterning the ink on the plate surface is an intaglio printing method.
Printing methods described in 5, 6, and 7. 9) Claims 1, 2, 3, 4, wherein the method of patterning the ink on the plate surface is a lithographic printing method.
Printing methods described in 5, 6, and 7. 10) Claims 1, 2, and 3, characterized in that the method of patterning the ink on the plate surface is a letterpress printing method.
The printing method described in 4, 5, 6, or 7. 11) A plate in which electromagnets capable of controlling non-selective magnetic field changes in each specific direction along a direction orthogonal to the specific direction are provided inside along the surface. 12) A blanket in which electromagnets that can control non-selective magnetic field changes in each specific direction along a direction orthogonal to the specific direction are provided inside along the surface. 13) Claim 1 characterized in that the plate is cylindrical, the specific direction is the dividing direction, and the direction orthogonal to the specific direction is the axial direction.
Version listed in 1. 14) The blanket according to claim 12, wherein the blanket is cylindrical, the specific direction is a dividing direction, and the direction perpendicular to the specific direction is an axial direction. 15) The plate according to claim 11, wherein the plate is flat. 16) The blanket according to claim 12, wherein the blanket has a flat plate shape. 17) A planar plate in which electromagnets are provided inside along the surface, which can change and control a non-selective magnetic field over the entire surface. 18) A planar blanket with internal electromagnets along its surface capable of varying and controlling a non-selective magnetic field over the entire surface.