JPH0784109B2 - Printing plate and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a printing plate and a manufacturing method thereof.

[Prior Art] Conventionally, for example, in a copper relief printing plate or an intaglio printing plate, the surface of the copper layer is plated with chromium in order to protect the surface and improve the printing durability.

[Problems to be Solved by the Invention] However, in the case of chrome plating, the waste liquid is harmful, requires expensive equipment and a considerably large installation space for the treatment of the waste liquid, and also has a large amount of hygiene management for workers. There is a problem. Further, since chrome plating requires polishing, not only the plate making cost becomes high, but also the plate making workability becomes poor.

Further, since the plate surface plated with hard chrome has a small wetting angle of the printing ink, the transferability of the ink to the printing paper is deteriorated and the printing finish is also adversely affected.

[Means for Solving the Problems] The present invention has been made to solve all such conventional problems, and a nickel layer in which particles of fluororesin are dispersed is provided as a protective layer on the surface of a printing plate. , And a method of producing a printing plate by plating the surface of the printing plate with nickel in which particles of a fluororesin are dispersed.

[Working] Since chrome plating is not performed, there is no need for waste liquid treatment, no polishing after plating is required, and the surface is protected to improve printing durability, and the wetting angle of printing ink is increased to transfer ink. It is possible to improve the sex.

Embodiments Embodiments of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, reference numeral 1 is a printing cylinder, on the surface of which a lead alloy layer or a copper layer 1a is provided with an image portion 2 protruding by corrosion, mechanical engraving or the like. Hereinafter, a printing cylinder having a copper layer 1a on its surface will be described in detail. 3 is the copper layer
This is a nickel plating layer plated on the surface of 1a, and particles 4 of fluororesin are dispersed in this layer. in this case,
The particle 4 has a diameter of 0.1 to 3.0 μm and its content is 10 to 35% by weight.

The plating film can be formed by either electroplating or electroless plating, and conventionally known plating methods can be adopted. For example, a fluororesin such as tetrafluoroethylene resin or a fluorine-containing compound such as graphite fluoride. If necessary, the particles can be dispersed in a desired plating solution in the presence of an activator for plating.

2 (I) to (IV) schematically show the state of the plating step, in which the particles 4 of the fluororesin are negatively charged in the plating solution. The positively charged nickel ions 5 are attached and the surroundings are positively charged, and some nickel ions are attached to the surface of the copper layer 1a of the negatively charged cylinder 1. After that, by appropriately adjusting the current density, the particles of the fluororesin to which the nickel ions 5 adhere are adhered and deposited on the surface of the copper layer 1a of the cylinder 1, and when this state progresses (Fig. As shown in IV), the nickel plating layer 3 is formed on the surface of the copper layer 1a, and the fluorine resin particles 4 are formed in the nickel plating layer 3.
Will be in a dispersed state.

A cylinder 1 for letterpress printing formed in this way,
When the coefficient of friction with the cylinder by another surface treatment was measured, the results shown in Table 1 were obtained. However, using a polished mild steel sheet as the mating material, vertical load (50
0g) is loaded.

According to this, when the fluororesin particles are dispersed at 35% by weight, a very excellent friction coefficient is obtained, and even when it is dispersed at 10% by weight, a friction coefficient superior to that of the conventional chrome plating is obtained. It was

Further, when the amounts of wear of various surface treatments were compared, Table 2 was obtained. However, the test was carried out with an LFW-1 type tester manufactured by Dow Corning, using steel as a counterpart material, and applying a load (13.6 Kg) in the atmosphere (25 ° C).

From this, it was found that the product of the present invention has an extremely small amount of wear.

Further, Table 3 shows the results of measuring the wetting angle between the plate surface and the ink. The product of the present invention has a significantly improved wetting angle with respect to toluene and water.

It was also found that the wetting angle can be arbitrarily adjusted by controlling the amount of dispersed fluororesin particles. It is considered that this is because the action of the fluororesin can adjust the non-adhesiveness of the intaglio surface and the inside of the cell in the case of the relief plate or the intaglio plate.

[Effects of the Invention] As described above, according to the present invention, the surface of the printing cylinder is plated with nickel in which fluororesin particles are dispersed, so that the printing durability is significantly improved and the wetting angle of the ink is increased. You can increase the size to make the print finish cleaner.

Further, since the mold release property of the surface of the printing plate is improved, it is possible to prevent dirt and ink dregs from being easily attached to the surface as in the past, which can easily cause stains on the printed matter.
Since the self-lubricating property of the surface of the printing plate is improved, there are advantages such as extending the life of the doctor.

Further, unlike the conventional case, since chrome plating is not performed, waste liquid treatment is unnecessary and pollution can be prevented, and polishing after plating is also unnecessary, so that plate making work efficiency is improved and cost is reduced. In addition to the effect, the present invention can be applied to both relief printing and intaglio printing.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a printing plate according to the present invention, FIG.
FIGS. (I) to (IV) are explanatory views schematically showing the plating process according to the present invention. 1 ... Cylinder, 1a ... Copper layer 2 ... Image part 3 ... Nickel plating layer 4 ... Fluororesin particles 5 ... Nickel ion

Front Page Continuation (72) Inventor Taritani Taniguchi 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (56) Reference JP-A-57-156259 (JP, A) JP-A-52-74403 (JP, A)

Claims (2)

[Claims] 1. A printing plate comprising a nickel layer having particles of fluororesin dispersed therein as a protective layer on the surface of the printing plate. 2. A method of manufacturing a printing plate, wherein a predetermined plate surface is formed on the surface of the printing plate, and then a plating step is carried out for surface protection. In the plating step, nickel plating in which fluororesin particles are dispersed is used. A method for producing a printing plate, comprising: