JP5120866B2 - Printing method - Google Patents

Description

  The present invention applies an ink on a blanket to form an ink application surface, presses the relief plate on the ink application surface to remove the ink in contact with the relief plate, and then removes the ink remaining on the blanket. The present invention relates to a printing method for transferring to a substrate (this printing method is also referred to as a letterpress reverse printing method in this specification).

  In the conventional general printing method, ink is applied to a printing plate produced with a lithographic plate, an intaglio plate, a relief plate, etc. to form an ink layer on the image area, and a printed image is formed by transferring this ink layer. . For this reason, the quality of the printed image depends on how to apply ink only to the image area and how to increase the transfer rate of the ink to the printing medium.

On the other hand, in the letterpress reverse printing method developed recently (see Patent Document 1), as shown in FIG. 6, the ink is uniformly applied from the ink application device 23 onto the blanket 22 attached to the surface of the cylinder 21. After forming the ink application surface 1 and pressing the relief plate 24 against the ink application surface 1 to remove the portion of the ink 2 in contact with the relief plate 24 from the blanket 22, the ink 3 remaining on the blanket 22 is covered. The image is transferred to the printing body 4.
According to this letterpress reversal printing method, by using the blanket 22 having high releasability such as silicone rubber, when transferring the ink 2 of the non-image area from the blanket 22 to the letterpress 24, the image area When the ink 3 is transferred from the blanket 22 to the substrate 4 to be transferred, a transfer rate of 100% or close to it is obtained. Therefore, a printed image having an image pattern in which the pattern of the convex portion 25 of the relief plate 24 is accurately inverted is obtained. It can be formed on the substrate 4.

An ink jet method is known as a printing method that does not use a printing plate. In Patent Document 2, an image is formed on a transfer body made of silicone rubber or a material having a certain releasability using an ink jet, and the ink on the transfer body is further transferred to a printing body. A plateless transfer printing method for obtaining an image is disclosed.
Japanese Patent No. 3689536 JP 2004-42584 A

However, when the area of the image area is smaller than that of the non-image area, it is necessary to remove most of the ink applied on the blanket with the relief printing according to the relief printing method. • The amount used for printing is small. When composition changes due to evaporation of ink components, or precipitation or aggregation of components occurs, it is difficult to reuse the ink removed by the letterpress, so it is necessary to use a much larger amount of ink than to transfer it to the printing medium. This leads to an increase in the cost of ink and an increase in the environmental burden associated with disposal.
When inkjet is used as described in Patent Document 2, an inkjet image is formed by a set of droplets. Therefore, when the droplet diameter is not negligible compared to the size of the image area, the edge of the image is Based on the outer peripheral shape of the droplet, it becomes a wavy shape, and a fine and sharp image line cannot be obtained.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a printing method capable of reducing the cost by eliminating waste of the amount of ink used and capable of forming a high-definition image. And

  In order to solve the above-mentioned problems, the present invention forms an ink application surface by applying ink on a blanket, and presses the relief plate on the ink application surface to remove the ink in the portion in contact with the relief plate from the blanket. Then, in the printing method for transferring the ink remaining on the blanket to the printing medium, the ink application surface on the blanket is from an area corresponding to an image pattern formed on the printing medium and its vicinity by an inkjet method. There is provided a printing method characterized by being formed in a region to be formed.

  According to the present invention, it is possible to reduce the amount of ink removed from a blanket with a letterpress, and it is possible to reduce the cost by eliminating waste of the amount of ink used. Since the shape of the ink edge on the blanket (the boundary portion between the image portion and the non-image portion) can be adjusted by the relief printing, a high-definition image can be formed.

  The present invention will be described below with reference to the drawings based on the best mode. FIGS. 1A to 1C are explanatory views illustrating respective steps according to the first embodiment of the printing method of the present invention. FIGS. 2A to 2C are diagrams of the printing method of the present invention. It is explanatory drawing which illustrates each process which concerns on a 2nd form example. In addition, each drawing of this specification is a drawing schematically shown for explaining the printing process, and the proportional relationship of dimensions does not particularly reflect the actual situation.

As shown in FIG. 1, the apparatus used in the first embodiment of the printing method of the present invention is the same as the apparatus used in the conventional relief printing method, and includes a blanket 12 attached to the surface of the cylinder 11 and a blanket 12. An ink application device 13 for applying ink thereon and a relief plate 14 having projections 15 in a pattern obtained by inverting the target image pattern formed on the printing medium 4 are essential. The letterpress plate 14 having a pattern obtained by inverting the target image pattern refers to the concave portion 16 corresponding to the image line portion on which the print image is formed on the printing medium 4 and the region other than the image line portion (that is, the non-image area). Corresponding to the (line part), it has the convex part 15. FIG.
In the present invention, an ink jet apparatus is used as the ink application apparatus 13. Further, as the blanket 12, it is preferable to use a material having a certain releasability such as silicone rubber.

The ink used in the present invention is suitable for the letterpress reversal printing method and needs to be suitable for being applied by being ejected onto a blanket by inkjet. As long as it has the above-mentioned aptitude, examples of the ink include, for example, those mainly composed of a resin (polymer), a solvent, and the like and arbitrarily added with various components. For example, in the case of black ink or colored ink, a coloring material such as a dye or pigment is blended, and in the case of conductive ink, a conductive material such as metal powder is blended. In addition to the ink used in the present invention, various additives can be added as necessary.
There are no particular limitations on the substrate to be printed, and examples thereof include plastic, paper, glass, ceramics, and metal.

(Ink application process)
In order to carry out the printing method of the present invention, first, as shown in FIG. 1A, ink is applied on a blanket 12 to form an ink application surface 1. In the present invention, the ink application surface 1 on the blanket 12 is formed only in a region corresponding to an image pattern (image line portion) to be formed on the printing medium 4 and a region including the vicinity thereof by an inkjet method. For example, when a linear pattern is to be formed, the ink application surface 1 may be formed with a line width slightly larger than the line width of the target pattern.

  In the conventional letterpress reversal printing method, the ink 2 corresponding to the non-image area is removed by the letterpress even if it is applied on the blanket 12, leading to wasted ink. Therefore, in the present invention, a portion 5 where no ink is applied is provided in a region corresponding to the non-image portion so that the amount of ink 2 removed by the relief plate 14 can be reduced. As a result, it is possible to reduce the cost by eliminating waste of the amount of ink used.

(Image formation process)
Next, as shown in FIG. 1B, the relief plate 14 is pressed against the ink application surface 1 to remove the portion of the ink 2 in contact with the relief plate 14 from the blanket 12. In this step, the ink 2 in the non-image area is transferred to the relief plate 14 and removed. In the ink application process, the ink application surface 1 is formed from the portion corresponding to the image pattern formed on the substrate 4 and the vicinity thereof. Therefore, the ink transferred to the relief plate 14 only needs to be in the vicinity of the image pattern. Thereby, waste of the amount of ink used can be eliminated. Further, by removing the non-image portion ink 2 from the ink application surface 1 on the blanket 12 by the relief plate 14, the edge of the ink 3 that becomes the image portion remaining on the blanket 12 (the boundary portion between the image portion and the non-image portion). ), The ink application surface 1 formed by inkjet can be fine and sharp even if the edge of the ink application surface 1 is undulated based on the outer periphery of the droplet. It is possible to obtain a simple line.

(Transfer process)
Next, as shown in FIG. 1C, the ink 3 remaining on the blanket 12 is transferred to the printing medium 4. In this step, the ink 3 remains only in the image line portion on the blanket 12 as in the conventional relief printing method, so that an image having the desired image line portion can be formed on the printing medium 4. It is.
Since the ink 3 remaining on the blanket 12 is partially dried prior to transfer, the ink pattern is not easily broken during transfer, and the pattern reproducibility of the printing plate is improved.

  As a modified example of the printing method of the present invention, FIG. 2 shows an example using a relief plate 14 in which a concave portion 17 is included in a non-image area. That is, according to the present invention, in the image forming process, it is not necessary to bring the convex portion 15 of the relief plate 14 into contact with the portion 5 where the ink is not applied on the blanket 12, and therefore, as shown in FIG. In this case, even if the portion corresponding to a part or the whole of the portion 5 where the ink is not applied on the blanket 12 is set as the concave portion 17, the image formation is not hindered.

<Method for forming a plurality of different image patterns with a single relief plate>
In the present invention, it is also possible to form an image with a plurality of different image patterns (two or more) with a single relief plate. For this purpose, a single relief plate having a plurality of different image patterns formed as recesses is used.
First, any image pattern is arbitrarily selected from a plurality of different image patterns formed as recesses on a single relief plate, and the selected image pattern is controlled by an ink application device in an ink application process. The ink application surface on the blanket is formed in a region consisting of a portion corresponding to and its vicinity. In the image forming step, the selected image is formed by pressing a single relief plate formed with a plurality of different image patterns as recesses against the ink application surface and removing the ink in contact with the relief plate from the blanket. Patterns can be imaged. Then, the image pattern arbitrarily selected can be printed by transferring the ink remaining on the blanket to the printing medium.

  In order to use a plurality of different image patterns formed as recesses on one relief plate (it is not necessary to use all the image patterns that can be formed on the relief plate), each image pattern is selected in an arbitrary order. For each selected image pattern, printing is performed by ink coating, image formation, and transfer processes. In these series of printings, different blankets may be used as blankets, or the same blanket may be used multiple times. As a result, it is possible to form an image of a plurality of different image patterns with a single relief plate. As a result, it is possible to reduce the cost of producing the relief plate, reduce the process of cleaning the relief plate every printing, make the entire printing apparatus compact, reduce the installation space of the printing apparatus, and the like.

  For example, FIG. 3 shows a case where a plurality of different image patterns are parallel fine line patterns having different pitches. In FIG. 3B and FIG. 3E, the relief plate 14 in which the recesses 16 are formed with the pitch a is a parallel fine wire pattern with a pitch a, a parallel fine wire pattern with a pitch 2a, a parallel fine wire pattern with a pitch 3a, and a parallel with a pitch 4a. It can be considered that a plurality of patterns such as a fine line pattern are included. That is, the relief printing plate 14 can form images of parallel fine line patterns having a plurality of pitches such as a, 2a, 3a, 4a,.

As a specific example, a method of printing a parallel fine line pattern having a pitch a and a parallel fine line pattern having a pitch 2a using a relief plate 14 having recesses 16 formed at a pitch a will be described with reference to FIG.
In order to print the parallel fine line pattern of pitch a, in the ink application process, as shown in FIG. 3 (a), the ink application surface 1 is placed on the area consisting of the line width of the parallel fine line pattern and the vicinity thereof. Form with. In the image forming process, as shown in FIG. 3B, the ink application surface 1 applied on the blanket 12 at a pitch a is brought into contact with the convex portion 15 of the relief plate 14 to make an extra portion that is near the line width. Ink 2 is removed from the blanket 12. Thereby, an image is formed on the blanket 12 with a parallel fine line pattern having a pitch a. In the transfer step, the ink 3 remaining on the blanket 12 is transferred to the printing medium 4 as shown in FIG. Thereby, the parallel fine line pattern of pitch a is printed on the to-be-printed body 4. FIG.

  Moreover, in order to print the parallel thin line pattern of the pitch 2a, in the ink application process, as shown in FIG. 3 (d), the ink application surface 1 is formed in the region consisting of the line width of the parallel fine line pattern and its vicinity. It is formed at a pitch 2a. In the image forming step, as shown in FIG. 3 (e), the ink application surface 1 applied on the blanket 12 at a pitch 2a is brought into contact with the convex portion 15 of the relief plate 14 to make an extra portion that is near the line width. Ink 2 is removed from the blanket 12. Thereby, an image is formed on the blanket 12 with a parallel fine line pattern having a pitch 2a. In the transfer step, as shown in FIG. 3F, the ink 3 remaining on the blanket 12 is transferred to the printing medium 4A. Thereby, the parallel thin line pattern of the pitch 2a is printed on the printing medium 4A.

  Similarly, the printing of the parallel thin line patterns with the pitches 3a, 4a,... Can be easily performed by controlling the ink application pitch by the ink jet method. In FIG. 3, the printed body 4 on which the parallel fine line pattern with the pitch a is printed and the printed body 4A on which the parallel thin line pattern with the pitch 2a is printed are distinguished by changing the reference for convenience of explanation. The present invention is not limited to the case where a plurality of different image patterns are printed on a plurality of different printing bodies, but can also be applied to the case where a plurality of different image patterns are printed on a single printing body.

  In the method of forming an image of a plurality of different image patterns with a single letterpress, the plurality of image patterns can be present at any location on the letterpress. For example, as in the example shown in FIG. 3, when forming a plurality of parallel thin wire patterns having different pitches, a relief plate in which concave portions are formed with a pitch that is the greatest common divisor of the pitches of the parallel thin wire patterns (that is, units of parallel thin wire patterns) When using a relief printing plate with recesses per unit length, which is the least common multiple of the number per unit length, the pitch of the parallel fine line pattern will be a multiple of the pitch of the depressions on the relief printing plate. Formation is possible.

As another example, there are a rectangular pattern and a triangular pattern in one letterpress, sometimes using only a rectangular part, sometimes using only a triangular part, and sometimes using a rectangular part and a triangle. Both parts can be used simultaneously.
In the case where a plurality of different image patterns are formed on a single relief plate, it is also possible to apply a method for printing a plurality of image patterns on a single printing medium, which will be described below. For example, when there are a rectangular pattern and a triangular pattern in one letterpress and printing using both the rectangular part and the triangular part at the same time, red ink is used for the rectangular pattern and blue ink is used for the triangular pattern. Can be used for two-color printing. As another example, when forming a parallel fine line pattern, the color of each fine line can be changed in a desired combination, and for example, a pattern in which red fine lines and blue fine lines are alternately repeated can be formed. is there.

<Method of printing a plurality of image patterns on one substrate>
Further, in the present invention, the ink application surface on the blanket is formed in a region corresponding to the image pattern formed on the substrate to be printed and a region including the vicinity thereof by the inkjet method. It is possible to form a plurality of ink-applied surfaces and transfer the plurality of ink-applied surfaces to the printing medium at once from the one blanket. Therefore, in order to print a plurality (two or more) of image patterns on one printing medium with each ink, one blanket equipped with a plurality of ink heads can be used. In this case, a method for mounting a plurality of ink heads on one blanket is a method by mounting a single ink application device having a plurality of ink heads, and an ink application device having one or more ink heads. A method of arranging two or more ink heads (the number of ink heads provided in each ink coating device may be the same or different) may be used.
By using different types of ink as each ink applied from each ink head, printing with a plurality of types of ink can be realized by one transfer.

  For example, FIG. 4 shows three color filters of red (R), green (G), and blue (B) on a printing medium on which a black matrix BM (lattice black line pattern) is formed on the printing surface. An example of a method of forming a color pattern is shown. According to this method, three color filter patterns can be formed at a time, and the process can be shortened and the productivity can be improved.

In the ink application process, as shown in FIG. 4A, a blanket 12 equipped with an ink head 13R for applying red ink, an ink head 13G for applying green ink, and an ink head 13B for applying blue ink is used. By using the ink heads 13R, 13G, and 13B, the ink application surfaces 1R, 1G, and 1B are formed at different positions on the one blanket 12 in areas corresponding to the respective image patterns and in the vicinity thereof. .
In the image forming step, as shown in FIG. 4B, the recess 16R corresponding to the red image pattern, the recess 16G corresponding to the green image pattern, the recess 16B corresponding to the blue image pattern, and these Using the relief plate 14 having the projection 15 formed between the recesses 16R, 16G, and 16B, the three color ink application surfaces 1R, 1G, and 1B applied on the blanket 12 are brought into contact with the projection 15 of the relief plate 14 As a result, excess ink 2R, 2G, 2B between the image patterns is removed from the blanket 12. Thus, three color image patterns 3R, 3G, and 3B are formed on one blanket 12.
In the transfer step, the ink 3R, 3G, 3B remaining on the blanket 12 is transferred to the printing medium 4 as shown in FIG. As a result, a three-color image pattern is printed on the printing medium 4. In the example of FIG. 4C, the black matrix BM is formed in advance at the boundary between the three color image patterns, and the three color inks 3R, 3G, 3B on the blanket 12 are the same on the black matrix BM. The image is transferred onto the printing material 4 including the portion. Examples of the method for forming the black matrix BM on the substrate 4 include the relief printing method of the present invention and the conventional relief printing method.

As described above, referring to FIG. 4, a method of printing a plurality of image patterns 3R, 3G, and 3B on each printing medium 4 with each ink, and a plurality of ink heads 13R for applying each ink. , 13G, 13B is used, and each ink application surface 1R, 1G is formed in a region corresponding to each image pattern and a region formed in the vicinity thereof by each ink head 13R, 13G, 13B. , 1B are formed at different positions on one blanket 12, and then a single relief plate 14 having a plurality of image patterns formed as recesses 16R, 16G, 16B is pressed against each ink application surface 1R, 1G, 1B. A plurality of inks 2R, 2G, 2B in contact with the relief plate 14 are removed on the blanket 12 by removing the ink 2R, 2G, 2B from the blanket 12. Image pattern 3R, 3G, 3B and in one letterpress 14 how to image forming at once shown by way of specific examples.
In FIG. 4, the case where the ink pattern of the three colors R, G, and B is applied to the blanket 12 is a parallel line pattern in the length direction of the cylindrical body 11 as an example. This is one example, and as another example, a pattern (see FIG. 5A) applied in a circular shape in the circumferential direction of the cylinder 11 or a rectangular ink application portion in the length direction of the cylinder 11. 4 (a) to 4 (c) using a relief printing plate corresponding to each application pattern, even if a mosaic application pattern (see FIG. 5 (b)) arranged two-dimensionally in the circumferential direction is used. Thus, a color filter pattern can be formed on the substrate.

  The letterpress used for image formation of the plurality of image patterns 3R, 3G, and 3B is not limited to one, and two or more letterpresses can be used together. For example, a plurality of relief plates having recesses corresponding to the respective image patterns 3R, 3G, 3B are used, and each relief plate is pressed against each of the ink application surfaces 1R, 1G, 1B to make contact with the relief plate. Is removed from the blanket, and a plurality of image patterns 3R, 3G, 3B can be formed on one blanket 12.

For example, as a set of relief plates for forming an image of three-color image patterns 3R, 3G, 3B, the following groups can be exemplified. Even when the number of types of image patterns is different, it will be possible to prepare and use an appropriate number of relief plates according to this example.
(1) A red relief plate formed with the red image pattern 3R as the recess 16R, a green relief plate formed with the green image pattern 3G as the recess 16G, and a blue relief plate formed with the blue image pattern 3B as the recess 16B. A set of three pieces,
(2) A set of two sheets of a red / green relief plate formed with the red image pattern 3R and the green image pattern 3G as the recesses 16R and 16G and a blue relief plate formed with the blue image pattern 3B as the recesses 16B,
(3) A set of two sheets, a red / blue relief plate formed with the red image pattern 3R and the blue image pattern 3B as the recesses 16R and 16B, and a green relief plate formed with the green image pattern 3G as the recesses 16G,
(4) A set consisting of a red relief plate formed with the red image pattern 3R as the recess 16R and a green / blue relief plate formed with the green image pattern 3G and the blue image pattern 3B as the recesses 16G and 16B.

In each letterpress, the convex part for removing excess ink includes a position in the vicinity of the image pattern imaged on the letterpress and does not include all image patterns imaged on one blanket. It is necessary to form in position.
For example, in the case of a red relief plate formed with the red image pattern 3R as the recess 16R (green and blue images are not formed), the projection 15 has a position in the vicinity of the red image pattern 3R. In addition, while leaving the red image pattern 3R on the blanket 12, the excess red ink 2R can be removed by contact, and the ink that forms the green and blue image patterns 3B and 3G is not contacted. There is a need. However, the convex portion 15 of the red letterpress includes the positions in the vicinity of the green and blue image patterns 3G and 3B, and may contact the green and blue inks 2G and 2B to be removed.

As described above, according to the printing method of the present invention, the amount of ink removed from the blanket 12 by the relief plate 14 can be reduced, and wasteful use of the ink can be eliminated and cost reduction can be realized. Further, since the shape of the ink edge (the boundary between the image portion and the non-image portion) on the blanket 12 can be adjusted by the relief plate 14, a high-definition image can be formed.
In addition, by forming a plurality of different image patterns with one relief plate, the number of plates can be reduced, a wide variety of image patterns can be created with one blanket and plate unit, and the entire printing apparatus can be made compact and printed. The installation space of the apparatus can be reduced.
In addition, by applying multiple ink types to one blanket at a time, the number of plates and blankets can be reduced, multi-color printing can be performed at one blanket and plate unit at a time, and the printing device can be made compact and printed. The installation space of the apparatus can be reduced.

  The present invention can be used for forming color filters, patterning resists, manufacturing electronic components, and the like.

It is a conceptual diagram explaining each process which concerns on the 1st form example of the printing method of this invention, (a) shows an ink application process, (b) shows an image formation process, (c) shows a transfer process. It is a conceptual diagram explaining each process which concerns on the 2nd form example of the printing method of this invention, (a) shows an ink application process, (b) shows an image formation process, (c) shows a transfer process. It is a conceptual diagram explaining the method of image-forming a several different image pattern with one relief printing using the printing method of this invention, (a), (b), (c) is a parallel fine wire of pitch a (D), (e), and (f) show the ink application process for printing a pattern, the image formation process, and the transfer process. The transfer process is shown. It is a conceptual diagram explaining the method of printing a several image pattern on one to-be-printed body using the printing method of this invention, (a) is an ink application process, (b) is an image formation process, (c) is The transfer process is shown. (A) is a perspective view which shows the example of the pattern apply | coated circularly in the circumferential direction of the trunk | drum, (b) is a perspective view which shows the example of a mosaic-like application pattern. It is a conceptual diagram explaining each process of the conventional relief printing method, (a) shows an ink application process, (b) shows an image formation process, (c) shows a transfer process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ink application surface, 2 ... Non-image area ink, 3 ... Image area ink, 4 ... Printed object, 11 ... Cylinder, 12 ... Blanket, 13 ... Ink application apparatus, 14 ... Letterpress, 15 ... Letterpress Convex part.

Claims (3)

Ink is applied onto the blanket to form an ink application surface, and the letterpress is pressed against the ink application surface to remove the portion of the ink in contact with the letterpress from the blanket, and then the ink remaining on the blanket is covered. In a printing method for transferring to a printed material,
The ink application surface on the blanket is formed in an area composed of a portion corresponding to an image pattern formed on a substrate and the vicinity thereof by an inkjet method.
Using one letterpress with a plurality of different image patterns formed as recesses, and using different blankets or using the same blanket multiple times, the portion corresponding to each image pattern on the blanket and its vicinity A plurality of different image patterns are formed by forming an ink-coated surface in a region consisting of, and then pressing the one relief plate on the ink-coated surface to remove a portion of the ink in contact with the relief plate from the blanket. Is a printing method in which an image is formed with one letterpress,
The printing method, wherein the plurality of different image patterns are parallel fine line patterns having a plurality of different pitches, and the one relief plate is a relief plate having recesses formed at a pitch that is the greatest common divisor of the pitches of the parallel fine line patterns. . The plurality of different image patterns are a parallel fine line pattern having a predetermined pitch a and a parallel fine line pattern having a pitch that is an integer multiple thereof, and the one relief plate corresponds to the image line portion at the predetermined pitch a. it is obtained by forming a recess, the printing method according to claim 1. The parallel fine line pattern is obtained by changing the color of each of the thin line in the desired combination printing method according to claim 1 or 2.

Images