JPS58209583A - Printing by intaglio print - Google Patents

Abstract

PURPOSE:To raise the unniformity of packing density of ink in concaved portions and also the squeezability of ink on an intaglio print plate by a doctor knife by a method in which printing is made by fixing the intaglio print plate through a rubber elastic material between a float board and the intaglio print plate. CONSTITUTION:A rubber elastic material is interposed between an intaglio print plate and a flat board to fix the intaglio print plate. By this, a cushioning property can be given to the hard intaglio print plate, and the squeezability of ink by doscto knife, uniformity of the packing density of ink, the printing resistance of the intaglio print plate, and the wear resistance of the docto knife can be raised. Also, the flatness and smoothness of the intaglio print plate is not so severely needed, and printing can be performed by directly pressing a picture portion onto a medium to be printed.

Description

[Detailed description of the invention] The present invention relates to an improved intaglio printing method.

Generally, this is a method typified by printing using intaglio (referred to as gravure printing or curved surface printing (tampo printing or evening printing)). Gravure printing involves creating four parts on a copper surface using photolithography, applying chrome plating, etc., applying ink to only the four parts using a doctor knife as a cylindrical intaglio plate, and then printing directly onto the surface of synthetic film, etc.

Additionally, in many cases, curved surface printing is performed on a flat steel plate, copper plate, or glass plate using photolithography, after which the pattern that will become the image area is made into a concave shape, and then quenching or other processes are applied to further improve the abrasion resistance of the surface. An intaglio plate that has been chrome-plated to a mirror-like finish is used and fixed to a flat plate stand using double-sided tape or mechanically. Next, print ink is applied to the entire surface of the intaglio plate using an inking roller or a brush (around the J recess), and then the ink on the plate is squeezed out using a doctor knife, and at the same time, the ink is packed only into the four parts. Then, you can press the printing material against the plate surface to directly transfer the four inks, or use a convex pad made of silicone rubber or urethane rubber (
The indirect method, in which the transfer image is transferred to the surface (which becomes a blanket) at once, and then the transfer pad is pressed against the surface of the printing material to transfer the transferred image to the printing material, and the droplet intaglio offset printing method is used. be.

In the case of curved surface printing, indirect printing using a pad is common, and direct printing is rarely performed. In other words, in curved surface printing, printing is often performed on the surface of a hard molded object such as plastic, metal, or glass that has a curved surface, so it is impossible to print by pressing the printing object directly onto the intaglio surface.

The disadvantage of intaglio printing methods, especially intaglio flatbed printing in which the intaglio is fixed on a flat plate, is that the ink used is different from gravure printing, and when printing, a highly viscous and hard ink is generally used. Therefore, when squeezing ink in non-image areas with a doctor knife, the contact force with the printing plate must be strong. In other words, since the ink is hard, unless the doctor knife is strongly pressed against the printing plate to squeeze it, the ink will not be completely removed and the ink will not enter the four areas that will become the printing areas sufficiently. If the squeezing of the ink is insufficient as described above, as a result of printing, unnecessary ink is transferred to the printing material and a printed product with sharp lines is not printed. In other words, the print quality is poor.

On the other hand, if the doctor knife is strongly pressed against the intaglio plate surface, the printing durability of the intaglio plate will be reduced, and the cutting edge of the doctor knife will tend to be partially damaged, resulting in scratches on the plate surface I. Therefore, with regard to intaglio printing using a doctor knife, printing conditions are currently extremely difficult and a major problem.

In view of the current situation, the inventors of the present invention have made extensive studies to solve the above problems, and as a result, have arrived at the present invention described below.

That is, in the present invention, an intaglio plate is fixed on a flat plate, printing ink is applied to the plate surface, and then the ink is skimmed with a doctor knife, and then the ink in the recesses that will become the image area is applied directly or indirectly. This invention relates to an intaglio printing method in which the intaglio is fixed and printed by interposing a rubber elastic body between the flat plate surface and the intaglio in a printing method in which the printing is transferred onto a printing material.

The intaglio plate referred to in the present invention is a commonly used printing plate made of flat steel, copper, or glass with the necessary image formed in four parts at a depth of about 10 to 50 μm. Each plate is made using a photoengraving method.

In addition, there is also an intaglio plate for printing made by photolithography using a photosensitive intaglio material made by uniformly coating a photosensitive resin to a thickness of about 10 to 300 μm on a substrate. This phenomenon is more noticeable in the case of photosensitive intaglio materials. Photosensitive intaglio materialsThe main components of photosensitive resins are polyester, polyurethane, cellulose, polyvinyl alcohol, polyamide, etc.
Among them, polyamides, polyurethanes, and celluloses are particularly preferable in view of necessary characteristics such as abrasion resistance, squeezing resistance, and surface hardness.

The doctor knife is made of commonly used steel, and the cross-sectional width of the cutting edge is about 0.1 to 0.5 mm, and the size varies depending on the size of the intaglio.

The opposite side of the blade is part of the holder, so it is wider than the width of the blade. It is also possible to use a doctor knife as a ceramic or plastic knife. Among ceramics, zirconia-based ceramic doctor knives are less likely to damage the cutting edge than conventional steel knives, and have a lower ink squeezability. etc., so it can be said to be a preferable doctor knife.

The flat plate for fixing the intaglio is not particularly limited, and may be made of stainless steel, glass, plastic, etc. that maintains its flatness accurately.

The printing ink used in the present invention is not particularly limited, but
The objects to be printed using this printing method include plastic molded objects, metal molded objects, glass molded objects with curved parts, flat molded objects thereof, paper molded objects, film-like objects, etc. Therefore, ink is selected depending on the material of the object to be printed. In most cases, screen printing inks, ultraviolet curing inks, and offset inks with relatively high viscosity and low tack are used.
= I can cry.

The intaglio plate is generally fixed to the plate (printing plate stand) mechanically (such as by drilling a hole in the side of the intaglio plate and tightening it with screws) or adhesively using double-sided tape, etc. In the invention, in particular, by interposing a rubber elastic body between the flat plate and the fixed intaglio plate, for example, the hard intaglio plate can be given cushioning properties, and the ink on the intaglio plate can be squeezed by a doctor knife and the ink can be easily squeezed into the recesses. This dramatically improves the uniformity of ink loading, the printing durability of the intaglio itself, and the damage and abrasion resistance of the doctor knife's cutting edge. In addition, the flatness or smoothness of the intaglio surface is a particularly important factor in squeezing property, but by interposing this rubber elastic body, the flatness or smoothness is too severe.
Another major effect is that smoothness is no longer required.

The rubber elastic body surface referred to herein is not particularly limited as long as it is made of a material that provides rubber-like elastic resilience, such as natural rubber, synthetic rubber, urethane rubber, silicone rubber, polyester rubber, etc. can be given. Rubber elasticity is affected not only by the material itself but also by the surface hardness.
In the present invention, the rubber hardness is about 40° or more, preferably 50 or more. Furthermore, even if the hardness is the same, it is affected by the shape, ie, the thickness, of the rubber elastic body, so if the hardness is low, it is preferable to use a sheet-like material that is as thin as possible. Generally, a rubber elastic sheet-like material having a thickness of 50 μm to 5 mm and having high flatness is used as the elastic body.

The sheet-like material may be made of the rubber-elastic resin itself, but may also be a sheet-like material in which a rubber-elastic resin is uniformly coated on a substrate, such as a metal plate or a synthetic film. The manufacturing procedure is simple, and mounting on a flat plate is preferable in terms of workability. Further, a sheet-like material made of a resin having rubber elasticity and surface adhesiveness is more preferable.

The method of fixing the rubber elastic body on the flat plate is not particularly limited. For example, the rubber elastic body may be fixed to the surface of the flat board with double-sided tape, and then the second intaglio plate may be further fixed to the surface of the rubber elastic body with double-sided tape or a part of the edge of the intaglio plate or the entire circumference of the plate with adhesive tape. Alternatively, it may be fixed mechanically. In addition, when fixing mechanically, it is preferable that the intaglio is fixed by pressure using a doctor knife so that the force applied to the intaglio itself can be uniformly transmitted to the surface of the rubber elastic body. In addition, if the rubber elastic body has surface adhesiveness, the intaglio plate can be fixed with one touch without using double-sided tape, and conversely, the plate can be easily attached and detached. This is preferable.

The printing method of the present invention can be applied to ordinary printing using intaglio materials.

Furthermore, since the present invention provides cushioning properties to the intaglio plate by the rubber elastic body interposed between the flat plate and the intaglio plate, the image area can be directly pressed onto the surface of the printing material without using a pad or the like. Printing is also possible, and this can also be said to be one of the major features of the present invention.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Printing was carried out under the following conditions using a pad printing machine type "'T-5" manufactured by Taihei Kogyo Co., Ltd.

(1) Intaglio: thickness 2mm, size 11l 10mm x 12
A depth of 30 mm created by photolithography at the center of a copper plate of 0.
A chrome-plated metal intaglio plate with an image of μ.The image on the intaglio plate was made using positive film with the words ``Curved surface printing, test chart'' written in Gothic letters of grade 7 phototypesetting. (2) Rubber elastic body: 18
8μ polyester film coated with polyurethane rubber with a rubber hardness of 8σ to a thickness of 100 tt (3) In-1 =: Screen printing ink for ABS resin <4) Pad: Silicone rubber with a rubber hardness of 10' (5) Doctor knife: Blade edge width Q, 3 mm, thickness of part of the holder to the support fitting is 1.5 mm, 15 mm x 1
First, fix a flat plate in the center of the boat-shaped receiver of the printing press with a knife made from a 15 mm long sword-shaped steel, and attach it to the plate using double-sided tape.
An elastic sheet was glued on, and an intaglio was fixed on top of this sheet with double-sided tape.

The pressure of the doctor knife against the intaglio surface is approximately 1.33.5
Printing was performed under three conditions: Kq/am'. A plate-shaped molded body made of ABS resin was used as the printing target. As for the printing results, the ink was sufficiently squeezed out and the image was printed clearly regardless of the pressing force of any doctor knife. The abrasion of the intaglio plate at the tti point after 30,000 printings was measured by the change in thickness, and there was no difference in the change in thickness in either case.

Comparative Example 1 Printing was carried out in the same manner as in Example 1, except that the rubber elastic body was not used and the adhesive was directly fixed to a flat plate using double-sided tape. As a result, the ink was not completely removed from the intaglio surface by a pressure of 1KCJ/Cl11', and printing stains appeared on the ABS resin plate surface. Also, 5KO/a
In the case of m2, the ink was completely removed, but the doctor knife was heavily worn and the intaglio was worn by 15% Iζ.

Example 2 Printing was carried out in accordance with Example 1, except that NBR synthetic rubber with rubber hardness of 3σ, 50'', 70°, and 90° was used as the rubber elastic body.

Ir, the above elastic body is a polyester film (0,2
5mm thick) with 1 layer of the above NBR synthetic rubber.
It is coated with 00μ and has cushioning properties. The results showed that the ink on the intaglio surface was sufficiently squeezed and printing was possible with each rubber elastic body. However, the amount of ink transferred to the ABS resin plate of the printed image (ink J9 only) decreased as the rubber hardness of the rubber elastic body decreased (became softer).

Fruit Color Example 3 Printing was carried out in the same manner as in Example 1 except that the following conditions were used for the intaglio, doctor knife, and pressure of the doctor knife.

(jl) Intaglio: Alcohol-soluble photosensitive polyamide was coated to a thickness of 35μ on a 0.35 mm thick polyester film, and the letters of Example 1 were developed with alcohol using a photolithography method on an intaglio resin plate that was adhered. An intaglio was made.

(2) Doctor knife: Made of zirconia ceramic, cutting edge width 0.3 mm, size 15 mm x 115 mm
Squeeze knife (3) Pressure of the doctor knife against the intaglio surface 1Ka/a
m2 After printing 50,000 times, the ink squeegee removability of the intaglio surface was extremely good. In addition, the doctor knife had better ink removal than a regular steel knife. Furthermore, the wear of the intaglio plate was extremely small at 5%, and there was no damage to the cutting edge.

Example 4 Comparative Example 2 In Example 2, the thickness accuracy of the intaglio was set to 0.358 mm ±
Example 2 was carried out using a photosensitive polyamide intaglio plate with an uneven thickness of 20μ, that is, 0.36 to 0.356 mm.
When printed in the same manner as above, the ink on the intaglio surface was squeezed cleanly without any problems.

On the other hand, when similar printing was performed without using the rubber elastic body, the ink in the thinner portions was not sufficiently removed by the doctor knife and remained on the plate surface. From this, it can be seen that even if the thickness accuracy of the intaglio is slightly poor, if a rubber elastic body is used, it will not be affected by the squeezing property of the ink.

Claims (1)

[Claims] (1) Fix the intaglio plate on a flat plate, apply printing ink to the plate surface, then squeeze the ink with a doctor knife, and then directly or indirectly apply the ink of the four parts that will become the image area to the printing substrate. A printing method using an intaglio plate, which is characterized in that the intaglio plate is fixed and printed by interposing a rubber elastic body between the flat plate surface and the intaglio plate.