JP2008111149A - Gravure plate making roll and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new gravure plate making roll with a surface reinforcement covering layer free from toxicity and also free from the risk of the generation in pollution at all, and further having excellent printing resistance, and to provide its production method. <P>SOLUTION: The gravure plate making roll comprises: a plate base material; a copper plating layer provided at the surface of the plate base material, and in which many gravure cells are formed on the surface; and a plating layer of nickel or its alloy covering the surface of the copper plating layer, and, its hardness is improved by heat-treating the plating layer of nickel or its alloy with superheated steam. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gravure printing roll and a method for producing the same, which can be provided with a surface-strengthening coating layer having sufficient strength without using chrome plating, and in particular, nickel or an alloy thereof as an alternative to a chrome plating layer. The present invention relates to a gravure plate making roll provided with a plating layer and a method for producing the same.

  In gravure printing, a minute concave portion (gravure cell) corresponding to plate making information is formed on a plate base material to produce a plate surface, and the gravure cell is filled with ink and transferred to a printing material. In general gravure plate-making rolls, the surface of a metal hollow roll (plate base material) such as aluminum or iron or a plastic hollow roll (plate base material) such as CFRP (carbon fiber reinforced plastics) is used for forming a plate surface. To provide a copper plating layer (plate material) and to form a large number of minute recesses (gravure cells) in accordance with the plate making information by etching or electronic engraving on the copper plating layer, and then to increase the printing durability of the gravure printing roll A hard chromium layer is formed by chrome plating to form a surface-enhanced coating layer, and plate making (plate surface production) is completed. However, because highly toxic hexavalent chromium is used in the chrome plating process, there is an extra cost to maintain work safety, and there are also problems of pollution, and the surface-enhanced coating layer replaces the chrome layer. The current situation is that the appearance of

As a plating method replacing chrome plating, there is a method of forming a plating layer of nickel or an alloy thereof by electrolytic plating or electroless plating, and the following patent documents 1 to 7 are known.
JP-A-2005-256170 JP 2005-146411 A Japanese Patent No. 2937426 Japanese Patent No. 3333561 Japanese Patent No. 3826651 US Pat. No. 6,200,450 US Pat. No. 6,372,118

  In view of the above-mentioned problems of the prior art, the present inventors newly prepared various plating solutions to develop a new plating method that replaces the chromium plating method, and as a result of many experiments, nickel or its Research was carried out on the assumption that alloy plating could be a powerful alternative to chrome plating, and the strength of the resulting nickel or alloy plating layer was not sufficient, and various studies were repeated to improve its strength. As a result, it has been found that by using heat treatment with superheated steam, a surface-enhanced coating layer having a strength comparable to that of a conventional chromium layer and having no toxicity and no concern about the occurrence of pollution can be obtained. completed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a novel gravure plate making roll having a surface-enhanced coating layer that is non-toxic and has no fear of occurrence of pollution, and is excellent in printing durability, and a method for producing the same.

  In order to solve the above problems, a gravure plate making roll of the present invention comprises a plate base material, a copper plating layer provided on the surface of the plate base material and having a number of gravure cells formed on the surface, and the copper plating layer A nickel or alloy plating layer covering the surface of the metal, and the nickel or alloy plating layer is heat-treated with superheated steam to improve its hardness.

  The plating layer of nickel or an alloy thereof is formed by electrolytic plating or electroless plating.

  The method for producing a gravure plate roll of the present invention comprises a step of preparing a plate base material, a copper plating step of forming a copper plating layer on the surface of the plate base material, and a number of gravure cells on the surface of the copper plating layer. A gravure cell forming step to be formed; a nickel plating step of forming a plated layer of nickel or an alloy thereof by electrolytic plating or electroless plating on the surface of the copper plating layer on which the gravure cell is formed; and plating of the nickel or the alloy thereof And a heat treatment step of heat-treating the layer with superheated steam.

  By further including a step of washing the surface of the heat-treated nickel or its alloy plating layer with cold water or hot water, the hardness of the nickel or its alloy plating layer can be further improved. Cold water should just use normal temperature water, and warm water should just use the heating water of about 40 to 100 degreeC. A washing time of about 30 seconds to 10 minutes is sufficient.

  It is preferable that the condition of the heat treatment with the superheated steam is 100 ° C. and 400 ° C. or less, 1 minute to 1 hour.

  In the gravure platemaking roll of the present invention, the copper plating layer has a thickness of 50 to 200 μm, the gravure cell has a depth of 5 to 150 μm, and the nickel or its alloy plating layer has a thickness of 0.1 to 15 μm. Preferably there is.

  The gravure cell may be formed by an etching method or an electronic engraving method, but an etching method is preferable. Here, the etching method is a method in which a gravure cell is formed by applying a photosensitive solution to the copper plating layer of the plate base material and directly baking it, followed by etching. The electronic engraving method is a method of engraving a gravure cell on the surface of a copper plating layer of a plate base material by mechanically operating a diamond engraving needle by a digital signal.

  According to the gravure plate roll of the present invention, the use of a plating layer of nickel or an alloy thereof heat-treated with superheated steam as the surface-enhanced coating layer eliminates the chromium plating step, so that highly toxic hexavalent chromium. This eliminates the need for extra costs for work safety, eliminates the risk of pollution, and the plating layer of nickel or its alloy heat-treated with superheated steam has a strength comparable to that of a chromium layer. And has a great effect of having excellent printing durability. According to the method for producing a gravure printing roll of the present invention, the gravure printing roll of the present invention can be produced effectively without any concern about the occurrence of pollution.

  Embodiments of the present invention will be described below, but these embodiments are exemplarily shown, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention.

  The manufacturing method of the gravure printing roll of this invention is demonstrated using FIG.1 and FIG.2. FIG. 1 is an explanatory view schematically showing a production process of a gravure plate making roll according to the present invention, where (a) is an overall sectional view of the plate base material, and (b) is a state in which a copper plating layer is formed on the surface of the plate base material. (C) is a partially enlarged sectional view showing a state in which a gravure cell is formed on the copper plating layer of the plate base material, (d) is a surface of the copper plating layer of the plate base material of nickel or its alloy. FIG. 4E is a partially enlarged cross-sectional view showing a state in which a plating layer is formed, and FIG. 4E is a partial enlarged cross-sectional view showing a state in which the hardness of the nickel or its alloy plating layer is improved by heat treatment with superheated steam. FIG. 2 is a flowchart showing a method for producing a gravure plate-making roll of the present invention.

  In FIG. 1A, reference numeral 10 denotes a plate base material, which is a metal hollow roll such as aluminum or iron or a plastic hollow roll such as CFRP (carbon fiber reinforced plastics) (step 100 in FIG. 2). A copper plating layer 12 is formed on the surface of the plate base material 10 by a copper plating process (step 102 in FIGS. 1B and 2).

  A large number of minute concave portions (gravure cells) 14 are formed on the surface of the copper plating layer 12 (step 104 in FIG. 1C and FIG. 2). As a method for forming the gravure cell 14, an etching method (a photosensitive liquid is applied to the plate cylinder surface and directly baked and then etched to form the gravure cell 14) or an electronic engraving method (a diamond engraving needle is machined by a digital signal) A known method such as engraving the gravure cell 14 on the copper surface can be used, but an etching method is preferred.

Next, a plating layer 16 of nickel or an alloy thereof is formed on the surface of the copper plating layer 12 (including the gravure cell 14) on which the gravure cell 14 is formed (step 106 in FIG. 1 (d) and FIG. 2). As a method for forming the nickel alloy plating layer 16, electrolytic plating or electroless plating is applied.

  Subsequently, the nickel or its alloy plating layer 16 is heat-treated with superheated steam to obtain a nickel or its alloy plating layer 18 with improved hardness (step 108 in FIGS. 1 (e) and 2). ).

  By causing the nickel or alloy plating layer 18 with improved hardness to act as a surface-enhanced coating layer, a gravure printing roll 10a having no toxicity and no concern about the occurrence of pollution and having excellent printing durability is obtained. Can do.

  It is preferable that the copper plating layer has a thickness of 50 to 200 μm, the gravure cell has a depth of 5 to 150 μm, and the nickel or alloy plating layer has a thickness of 0.1 to 15 μm. The thickness of the nickel or its alloy plating layer is more preferably 1 to 10 μm, and most preferably 3 to 10 μm.

A known method may be applied to the electrolytic plating method or the electroless plating method used to form the nickel or its alloy plating layer.
The plated layer 16 of nickel or an alloy thereof has glitter and high reflectivity, and has a hardness in the range of 700 to 900 in the deposited state. Has hardness. This heat treatment may be performed at a temperature exceeding 100 ° C. and not more than 400 ° C. for about 1 minute to 1 hour. Moreover, this nickel alloy plating layer has high heat resistance, corrosion resistance, and abrasion resistance as deposited. The coating is non-porous and is not cracked. The plated layer of nickel or an alloy thereof subjected to the heat treatment with superheated steam has an advantage that it can be replaced with chromium, hard chromium, and a chromium alloy.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

(Example 1)
Formation of a copper plating layer described below using a boomerang line (a gravure plate manufacturing apparatus manufactured by Sink Laboratory Co., Ltd.) for a plate base material (aluminum hollow roll) having a circumference of 760 mm, a surface length of 1100 mm, and an area of 83.6 dm ² The etching process was performed. First, the plate base material (aluminum hollow roll) is mounted on the plating tank, the anode chamber is brought close to the hollow roll up to 20 mm by an automatic slide device by a computer system, the plating solution is overflowed, and the hollow roll is completely submerged. A copper plating layer of 80 μm was formed at dm 2 and 6.0V. The plating time was 20 minutes, and the surface of the plating was free of spots and pits, and a uniform copper plating layer was obtained. The surface of the copper plating layer was polished for 12 minutes using a 4H polishing machine (Sink Laboratory polishing machine) to make the surface of the copper plating layer a uniform polishing surface.

  A photosensitive film (thermal resist: TSER-2104E4) was applied to the copper plating layer formed above (fonte coater) and dried. The film thickness of the obtained photosensitive film was 4 μm as measured by a film thickness meter (F20 manufactured by FILLMETRICS, sold by Matsushita Techno Trading). The image was then developed with laser exposure. In the laser exposure, a laser stream FX was used and a predetermined pattern exposure was performed under an exposure condition of 5 minutes / m 2/10 W. The development was performed at 24 ° C. for 60 seconds at a developer dilution ratio (stock solution 1: water 7) using a TLD developer (Sink Laboratory Co., Ltd. developer) to form a predetermined pattern. This pattern was dried (burned) to form a resist image.

  Further, cylinder printing was performed to engrave an image composed of gravure cells, and then the resist image was removed to form a printing plate. At this time, a cylinder was manufactured with a gravure cell depth of 12 μm. The etching was performed by a spray method under the conditions of a copper concentration of 60 g / L, a hydrochloric acid concentration of 35 g / L, a temperature of 37 ° C., and a time of 70 seconds.

The cylinder printing plate described above was immersed in the following electroless plating solution to form a coating having a thickness of 8 μm on the plate surface.
Nickel chloride 30g / L
Sodium hypophosphite 10k / L
Sodium hydroxyacetate 50g / L
Silicon carbide powder 5g / L
Temperature 90 ° C
pH 5
The resulting coating had a Vickers hardness of 713. Subsequently, after the surface of the coating was polished with sandpaper, heat treatment was performed at 300 ° C. for 10 minutes using superheated steam, and the Vickers hardness of the coating was measured to be 1016.

  Furthermore, cyan ink Zahn cup viscosity 18 seconds (water-based ink super rampy pure indigo 800PR-5 manufactured by Sakata Inx Co., Ltd.) was applied to the above-mentioned gravure cylinder as printing ink, and OPP (Oriented Polypropylene Film: biaxially oriented polypropylene film) A printing test (printing speed: 120 m / min) was performed. The obtained printed matter had no plate fog and could be printed up to a length of 50,000 m. The accuracy of the pattern did not change. Also, there was no problem with the adhesion of the plated layer of nickel or its alloy to the etched copper plating cylinder. Since the gradation from the highlight portion to the shadow portion of the gravure cylinder of the present invention was not different from that of the chrome-plated gravure cylinder produced according to a conventional method, it is determined that there is no problem in ink transferability. As a result, it was confirmed that the surface-enhanced coating layer composed of a nickel alloy plating layer and a silicon dioxide film has a performance comparable to that of a conventional chromium layer and can be sufficiently used as a substitute for the chromium layer.

(Example 2)
The following electrolytic plating was carried out under the conditions of a liquid temperature of 55 ° C., a time of 6 minutes, and a current density of 4 A / dm ^{2 in place} of the electroless plating in Example 1, and a nickel plating layer having a thickness of 5 μm was formed. A gravure cylinder was created as in 1. When the Vickers hardness of the coating was measured, it was the same as that of Example 1. Subsequently, when a printing test was performed in the same manner as in Example 1 using this gravure cylinder, the surface-enhanced coating layer composed of a nickel or alloy plating layer as in Example 1 has a performance comparable to that of a conventional chromium layer. It was confirmed that it can be used satisfactorily as a chromium layer substitute.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows typically the manufacturing process of the gravure printing roll of this invention, (a) is whole sectional drawing of a plate base material, (b) is a part which shows the state which formed the copper plating layer in the surface of a plate base material Enlarged sectional view, (c) is a partially enlarged sectional view showing a state in which a gravure cell is formed on a copper plating layer of the plate base material, and (d) is a plating layer of nickel or an alloy thereof on the surface of the copper plating layer of the plate base material. FIG. 5E is a partially enlarged cross-sectional view showing a formed state, and FIG. 5E is a partially enlarged cross-sectional view showing a state in which a nickel or alloy plating layer is heat-treated with superheated steam. It is a flowchart which shows the manufacturing method of the gravure printing roll of this invention.

Explanation of symbols

10: Plate base material (hollow roll), 10a: Gravure plate roll, 12: Copper plating layer, 14: Gravure cell, 16: Nickel or its alloy plating layer, 18: Nickel or its alloy heated by superheated steam Plating layer.

Claims (7)

  A plate base material, a copper plating layer provided on the surface of the plate base material and having a number of gravure cells formed thereon, and a nickel or alloy plating layer covering the surface of the copper plating layer. A gravure plate making roll characterized in that its hardness is improved by heat-treating the nickel or alloy plating layer with superheated steam.   The thickness of the copper plating layer is 50 to 200 µm, the depth of the gravure cell is 5 to 150 µm, and the thickness of the plating layer of the nickel or its alloy is 0.1 to 15 µm. The gravure printing roll described.   The gravure printing roll according to claim 1 or 2, wherein the plating layer of nickel or an alloy thereof is formed by electrolytic plating or electroless plating.   A step of preparing a plate base material, a copper plating step of forming a copper plating layer on the surface of the plate base material, a gravure cell forming step of forming a number of gravure cells on the surface of the copper plating layer, and the gravure cell A nickel plating step of forming a plating layer of nickel or an alloy thereof by electrolytic plating or electroless plating on the surface of the copper plating layer on which is formed, and a heat treatment step of heat-treating the plating layer of nickel or an alloy thereof with superheated steam And a method for producing a gravure plate making roll.   The thickness of the copper plating layer is 50 to 200 µm, the depth of the gravure cell is 5 to 150 µm, and the thickness of the plating layer of the nickel or its alloy is 0.1 to 15 µm. The manufacturing method of the gravure plate-making roll of description.   6. The method for producing a gravure printing roll according to claim 4, further comprising a step of washing the surface of the heat-treated nickel or alloy plating layer with cold water or warm water.   A method for producing a gravure plate, characterized in that the condition of the heat treatment with superheated steam is over 100 ° C. and 400 ° C. or less, 1 minute to 1 hour.

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