KR101732452B1

KR101732452B1 - Gravure printing roll made of aluminum base material and method of manufacturing the same

Info

Publication number: KR101732452B1
Application number: KR1020150130852A
Authority: KR
Inventors: 이상진; 강서영; 김명진
Original assignee: 주식회사 이피랩
Priority date: 2015-09-16
Filing date: 2015-09-16
Publication date: 2017-05-08
Also published as: KR20170033039A

Abstract

The present invention relates to an aluminum roll; A zinc oxide coating layer applied to the outer periphery of the aluminum roll; A copper plating layer applied to the ginning coating layer and having a printed pattern formed thereon; And a nickel-tungsten alloy layer applied to the copper plating layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum-based gravure printing roll,

In the present invention, the use of an aluminum roll as a base roll facilitates ease of use, uniformity of plating, etc., and is high in durability due to, for example, anisotropy. In addition, in order to protect a copper- To a nickel-tungsten alloy layer to improve the strength and abrasion resistance while being eco-friendly, and a method for producing the same.

Generally, in the gravure printing roll, a printing pattern is formed on a copper plating layer after a copper plating layer for forming a printing surface is formed on a surface of a steel roll, and a chromium plating layer is formed on the copper plating layer. And so on.

However, in the case of a steel roll, problems such as corrosion may occur during use, so that durability can not be guaranteed. In the case of a chromium plating layer for protecting the copper plating layer, a plating bath containing hexavalent chromium is usually used It is pointed out that it is an environmental pollution source together with the safety of work.

In addition, in the case of the currently commercialized gravure printing roll, the surface hardness and the abrasion resistance are improved by applying a hexavalent chrome plating layer to the copper plating layer on the surface of the copper plating layer with a thickness of about 5 to 7 μm. In this case, As can be seen, it causes a considerable amount of microcracks in the plated layer. Such fine cracks cause a chiping phenomenon on the surface of the plating layer. In the case of precision devices requiring micro-scale precision, there is a problem that chiping acts as a main failure factor which deteriorates the reliability of a printed pattern. Furthermore, in gravure printing, there is a problem in that a large amount of continuous product is produced through the same plate produced in the form of a roll, resulting in a large loss such as a defective product being generated in proportion thereto.

Korea Patent No. 1328314

An object of the present invention is to provide an aluminum-based gravure printing roll which solves problems such as environmental problems caused by a chromium plating layer and defects caused by microcracks while using an aluminum roll excellent in corrosion resistance, And a method for producing the same.

The aluminum-based gravure printing roll of the present invention for achieving the above object comprises an aluminum roll; A zinc oxide coating layer applied to the outer periphery of the aluminum roll; A copper plating layer applied to the ginning coating layer and having a printed pattern formed thereon; And a nickel-tungsten alloy layer applied to the copper plating layer.

In one embodiment, the ginkgo coating layer comprises 400 to 500 g / l of sodium hydroxide, 80 to 100 g / l of zinc oxide, 1 to 3 g / l of calcium nitrate, and 0.5 to 1 g / l of sulfur iron oxide.

The present invention also provides a method of producing an aluminum-based gravure printing roll, comprising: removing a smur from an aluminum roll; Applying a zincate coating layer to the smoothed aluminum roll; Applying a copper plating layer to the ginning coating layer; forming a printing pattern on the copper plating layer; And applying a nickel-tungsten alloy layer to the copper plating layer on which the printing pattern is formed.

As an example, in the step of removing the smut from the aluminum roll, a surface treatment is performed on the aluminum roll using the treatment liquid, wherein the treatment liquid contains 40 to 50% by weight of sulfuric acid, 3 to 6% by weight, and dinonylnaphtylsulfonic acid ammonium salt in an amount of 1 to 3% by weight, and the balance being the remainder.

The aluminum-based gravure printing roll according to the present invention is advantageous in that it can be easily used by using an aluminum roll as a base roll, has high electric conductivity and is excellent in uniformity of plating, and has high rustproofing property to improve durability.

In addition, the aluminum-based gravure printing roll of the present invention has an advantage of securing a strong adhesive force with a copper plating layer in which a printed pattern is formed by pretreatment of a ginning coating layer without a separate nickel strike.

In addition, the aluminum-based gravure printing roll of the present invention is effective in eliminating smut and capable of controlling the generation of harmful substances, and thus has an advantage of being environmentally friendly as well as an adhesive force to the upper plating layer.

1 is a view showing microcracks caused by a chromium plating layer,
2 is a block diagram showing a method for producing an aluminum-based gravure printing roll of the present invention.

Hereinafter, the aluminum-based gravure printing roll of the present invention and its manufacturing method will be described.

The aluminum-based gravure printing roll of the present invention comprises an aluminum roll; A zinc oxide coating layer applied to the outer periphery of the aluminum roll; A copper plating layer applied to the ginning coating layer and having a printed pattern formed thereon; And a nickel-tungsten alloy layer applied to the copper plating layer.

First, the present invention uses an aluminum roll as a base roll. The aluminum roll has a smaller specific gravity than conventional steel rolls and is easy to use by the user. The electric conductivity of the aluminum roll is equivalent to about 3.7 times as much as that of steel, which is advantageous in uniform electrodeposition and hardness increase.

In addition, the existing steel rolls are easy to cause corrosion during use and cause durability deterioration.

In the case of the aluminum roll, the conventional steel roll requires plating of the nickel strike by the pretreatment of the copper plating layer, but it is easy to process because it can replace the pretreatment by applying a simple zincate coating layer.

The ginkgo coating layer is a pretreatment of a copper plating layer, and in particular, a composition of a ginkgo coating layer is presented in the present invention. The composition of the present embodiment is characterized by containing 400 to 500 g / l of sodium hydroxide, 80 to 100 g / l of zinc oxide, 1 to 3 g / l of calcium nitrate, and 0.5 to 1 g / l of sulfur iron oxide.

The zincate coating layer with such a composition forms a fine and uniform zinc layer and reduces the internal residual stress of the copper plating layer to be formed thereafter to improve mutual adhesion.

Particularly, the gin-coated coating layer contains calcium hydroxide and iron oxide in addition to ordinary sodium hydroxide and zinc oxide, which may cause microcracks in the coating layer during coating and curing of the zinc oxide coating layer on the aluminum roll. Microcracks cause a decrease in adhesion with the copper plating layer, so that the coating layer further contains calcium nitrate and sulfur oxide.

The calcium nitrate absorbs a part of the hardening heat in the course of the reaction, thereby lowering the total hardening heat, and by this action, the occurrence of micro-cracks due to the hardening heat is controlled.

However, when a large amount of calcium nitrate is contained in order to reduce hardening heat, calcium nitrate itself is weak in hardness and may lower the overall strength, so that in the present invention, sulfur oxide is added in addition to calcium nitrate. Sulfur iron oxide controls the autogenous shrinkage of the paste by delaying the reaction rate of the other composition to induce a continuous reaction.

That is, the addition of the sulfur iron oxide added for the purpose of delaying the reaction can significantly suppress the shrinkage of the paste. This is because sulfur iron oxide generates needle-like crystals during the curing process and induces the paste to a dense structure by the growth pressure of the needle-shaped crystals.

In other words, the effect of shrinkage can be reduced by obtaining expansion pressure as a number of fine needle-like crystals are developed, and furthermore, it is possible to control microcracks by a closed structure, and only sodium hydroxide and zinc oxide It is possible to remove the cause of the adhesion failure of the precipitate due to the precipitate.

The copper plating layer is for forming a print pattern having a desired shape, and examples of forming various print patterns may be presented. For example, a resist may be formed on the copper plating layer and cured and etched. Accordingly, a copper plated layer on which a desired print pattern is formed can be formed.

Since the copper plating layer is relatively hard, it is easily worn or damaged. In general, a chromium coating layer is used as a reinforcing coating layer on the copper plating layer, which may lead to environmental problems as mentioned above. In the present invention, a nickel-tungsten alloy layer is presented.

The nickel-tungsten alloy layer contains nickel (Ni) and tungsten (W), and the alloy layer has a hardness of 700 Hv or more, high corrosion resistance, and excellent surface gloss. For example, the nickel-tungsten alloy layer may contain 5 wt% to 15 wt% of tungsten. If the amount of tungsten is less than 5 wt%, the nickel-tungsten alloy layer may not have strength equivalent to that of the conventional chromium plating layer. Further, when tungsten exceeds 15% by weight, there is an uneconomical problem.

Preferably, the tungsten content is 10 wt% to 15 wt%. In this composition, the alloy layer is amorphous, chemically stable, and high in hardness. Also, because it is amorphous, there is no fear of contamination.

When the nickel-tungsten alloy layer exhibits a mechanism of action in the printing process, the doctor blade moves in contact with the surface of the gravure printing roll when the printing pattern is filled with ink. At this time, there is a problem in that the number of times of contact between the doctor blade and the gravure printing roll increases, and the surface of the gravure printing roll is damaged, shortening the service life.

Therefore, the gravure printing roll surface is strengthened through the nickel-tungsten alloy layer having high strength and abrasion resistance, and as mentioned above, it is possible to replace the chromium plating layer, which is a pollution inducing material, And causes microcracks due to the residual stress density, thereby solving the problem of causing defective factors such as lowering the reliability of the print pattern.

In the present invention, as shown in FIG. 2, a method for producing an aluminum-based gravure printing roll is presented.

The manufacturing method of the present invention includes a step (S10) of removing a smut from an aluminum roll; (S20) applying a zincate coating layer to the smoothed aluminum roll; Applying a copper plating layer to the ginning coating layer (S30): forming a printing pattern on the copper plating layer (S40); And a step (S50) of applying a nickel-tungsten alloy layer to the copper plating layer on which the printing pattern is formed.

First, there is a step (S10) of removing the smut from the aluminum roll.

The aluminum roll is mixed with aluminum and a small amount of metal components such as silicon, iron, copper, manganese, magnesium, zinc and nickel. In order to improve the corrosion resistance and the beauty of the surface of the aluminum roll, ), Anodizing, and the like.

At this time, the degreasing process is performed, and since the sodium hydroxide is generally used in an amount of 3 to 20% as an etchant, the aluminum component is dissolved in the aqueous ionic state by the aqueous alkali solution, but the small amount of silicon, iron, copper, Metal components such as magnesium, zinc and nickel are not dissolved in the alkali aqueous solution and remain on the surface of the material in a protruded state, which forms a smut.

In order to remove such smut, a concentrated aqueous solution of nitric acid is conventionally used, and a mixed aqueous solution is added by adding hydrofluoric acid to remove the smut by the silicon component which is not dissolved in the high concentration nitric acid aqueous solution.

However, a large amount of nitrogen oxides (NOx) gas is discharged by the use of nitric acid, and the hydrofluoric acid is discharged by the use of hydrofluoric acid, and nitric acid nitrogen of high concentration occurs in the wastewater, which may threaten the safety of workers exposed in a closed workplace And there is a problem that it is not easy to treat nitrate nitrogen at a high concentration in wastewater.

Accordingly, in the present invention, as the treatment liquid for removing the smut of the aluminum roll, 40 to 50% by weight of sulfuric acid, 3 to 6% by weight of ascorbic acid and 1 to 3% by weight of dinonylnaphthylsulfonic acid ammonium salt are added to 100% And the remaining balance being water.

The treatment liquid is conventionally used in place of nitric acid, and sulfuric acid is used as the main ingredient. If the total amount of the treatment liquid is more than 50 wt%, the aluminum raw base material component tends to be etched with less than 40 wt% The removal efficiency of the element is insignificant and is limited as described above.

In addition, ascorbic acid and dinonylnaphthylsulfonic acid ammonium salts are further added to the above-mentioned range in the treatment liquid.

When treated with a strong acid such as sulfuric acid, the surface becomes positively charged when the pH of the cleaning solution is lower than the PZC of the metal oxide such as iron oxide or manganese oxide. When the pH is lower, the charge amount is increased.

As the pH of the treatment solution is lowered, the eluted anions are not dissolved and re-adsorbed to the residual iron oxide, manganese oxide, and the like, in the various anions eluted by the acid. In addition, when a treatment solution of strong acid is used, the solubility of metal oxides such as iron oxide and manganese oxide is increased, but the remaining metal oxides such as iron oxide and manganese oxide that do not dissolve are formed as the pH of the washing solution is low and act as a very strong adsorbent .

And the anions eluted therefrom are strongly adsorbed to metal oxides such as iron oxide and manganese oxide, resulting in a problem that smut removal efficiency is rather lowered.

Accordingly, in the present invention, the pH is lowered by treatment with sulfuric acid to remove the smut, and in addition, the addition of the ascorbic acid prevents the elution of the anion from being oxidized, thereby controlling the deterioration of the smut removal efficiency due to re- will be.

In addition, in the present invention, dinonylnaphthylsulfonic acid ammonium salt is further included so that the treatment liquid contains the ascorbic acid. The reason why the dinonylnaphthylsulfonic acid ammonium salt is further included in this way is to prevent the ions eluted by the ascorbic acid from being oxidized and at the same time to prevent adsorption by water absorption by the dinonylnaphthylsulfonic acid ammonium salt, And to control the generation of re-adsorbed material that is not also treated by the acid.

And then (S30) coating a copper plating layer on the ginkgo coating layer. Herein, the composition of the ginkgo coating layer is the same as described above, and a description thereof will be omitted.

And then forming a print pattern on the copper plated layer (S40).

Finally, a step (S50) of applying a nickel-tungsten alloy layer to the copper plating layer on which the printing pattern is formed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims

Aluminum roll;
A zinc oxide coating layer which is applied to the outer periphery of the aluminum roll and contains 400 to 500 g / l of sodium hydroxide, 80 to 100 g / l of zinc oxide, 1 to 3 g / l of calcium nitrate and 0.5 to 1 g / l of sulfur iron oxide;
A copper plating layer applied to the ginning coating layer and having a printed pattern formed thereon;
A nickel-tungsten alloy layer applied to the copper plating layer;
Wherein the gravure printing roll comprises an aluminum-based gravure printing roll.

delete

Removing the smut from the aluminum roll;
Applying a zinc oxide coating layer containing 400 to 500 g / l of sodium hydroxide, 80 to 100 g / l of zinc oxide, 1 to 3 g / l of calcium nitrate and 0.5 to 1 g / l of sulfur iron oxide to the smoothed aluminum roll, ;
Applying a copper plating layer to the ginkgo coating layer;
Forming a printed pattern on the copper plated layer;
Applying a nickel-tungsten alloy layer to a copper plating layer on which a printing pattern is formed;
Based printing roll.

The method of claim 3,
In the step of removing the smut from the aluminum roll,
The surface treatment is performed on the aluminum roll using the treatment liquid, wherein the treatment liquid contains 40 to 50% by weight of sulfuric acid, 3 to 6% by weight of ascorbic acid, 1 to 3% by weight of dinonylnaphthylsulfonic acid ammonium salt, By weight based on 100% by weight of the total weight of the aluminum-based gravure printing roll.