JPH0352544B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for industrially forming a green-blue film relatively quickly on the surface of copper or copper alloy products, particularly copper plates for building materials used as roofing materials. be. [Prior Art] Many patent applications have been filed so far for methods of industrially forming a green-blue film on the surface of copper or copper alloy products, particularly copper plates for building materials used as roofing materials. Chemical treatment methods, such as chemical conversion treatment methods, chemical electrolytic treatment methods, chemical conversion treatment and further painting methods, methods of painting with paints containing green-blue-forming substances, and sandblasting, etc., on roughened copper surfaces. Examples include a method of bonding copper powder or copper alloy powder with an adhesive and then applying a treatment liquid having a patina effect to form a patina film. As a method that falls under the above method,
-110235, JP-A-53-122637, JP-A-53-
122638, JP 55-8490, JP 56-9270, JP 56-30396, JP 57-51468, etc.
In either method, drying after treatment is done naturally or it is necessary to repeat treatment and drying, so not only is the rate of green-blue color development slow, but also the adhesion of the green-blue film is poor. There are problems such as not necessarily being suitable in terms of quality or industrial production. As a method that corresponds to the above method,
122641, Japanese Patent Publication No. 55-12117, Japanese Patent Publication No. 55-14157, Japanese Patent Publication No. 55-15558, and Japanese Patent Publication No. 177997, etc., which generate patina on the copper surface in a short time during the treatment process using an electrolytic method. However, there are problems in that the formed patina film is likely to peel off and a large amount of equipment investment is required. As applicable to the method of
8491, JP-A No. 56-13483, etc., but they have the problem that it is difficult to stably form a patina film. As applicable to the method of
139467, but it has the problem that adhesion deteriorates due to chocking of the coating film due to aging of the patina film. As applicable to the method of
69375, and Japanese Patent Publication No. 57-52425, but all of these methods require a large number of steps to form a verdigris film, and have problems in terms of productivity and processing cost. In order to solve these problems, the inventors
As the main inventor, he completed a treatment solution for coatings that promote patina and filed a patent application (Japanese Patent Application No. 126235/1983). After applying this treatment solution to the surface of copper or copper alloy and drying it, an excellent patina film can be formed by exposing it outdoors for a short time of about one month, but it takes about one month of outdoor exposure for it to turn green. It is necessary. [Object of the invention] The present invention was made with the aim of solving the above-mentioned problems and forming a patina film that is excellent in terms of appearance and adhesion in industrial production, that is, a patina promotion treatment process. At the time, the above-mentioned patent application was filed in 1982.
-Improvement of the method for promoting the formation of a patina film using the treatment solution for a patina-promoting film of 126235, that is, a water-based resin of 10 to 300 g/solid content, a compound that forms a complex salt with copper ions, and a chelate bond with the copper ions. An aqueous solution or aqueous suspension containing a total amount of 20 to 500 g of the compound is applied to the surface of clean copper or copper alloy, and after this is forced dry, water and/or steam is sprayed onto the applied surface. Or, by exposing the coated surface to a relative humidity of 90% or higher, the coated surface develops a greenish-blue color, and then dries, i.e., a greenish-blue color with excellent appearance and adhesion is obtained in the above surface treatment process. The present invention aims to provide a novel method for forming a patina film that approximates natural patina, which is extremely superior in terms of industrial production, and which allows the film to be formed throughout the year without being affected by outside temperature and humidity. The concentration of the compound that chelates with the copper ion is preferably 5 to 480 g/, and the concentration of the compound that forms a complex salt with the copper ion is preferably 20 to 495 g/. [Structure of the Invention] The present invention, which has been made to achieve the above object, provides an aqueous solution containing a water-based resin and a compound that forms a complex with copper ions and a compound that forms a chelate bond with copper ions as a compound that promotes patina. After applying a treatment solution consisting of a cloudy liquid to the surface of clean copper or copper alloy and forcing the coated surface to dry, water and/or steam is sprayed onto the coated surface to develop color, or the relative humidity is 90% or more. By exposing the coated surface to an atmosphere of It is possible to form a film. [Description of Composition and Conditions] The water-based resin contained in the treatment liquid used in the present invention may be either water-soluble or water-dispersible, and the types of resin include acrylic, alkyd, urethane, Commonly used resin compositions such as polyester-based resin compositions are applicable. The resin content in the treatment liquid is preferably 10 to 10% in terms of solid content.
300g/(particularly preferably 50 to 300g/). A patina film formed with a treatment solution containing less than 10 g/g/ml has poor adhesion. A treatment solution containing 300 g/or more could not be prepared because the solid content of the water-based resin used in the examples of the present invention was lower than 50%. Substances that form complex salts with copper ions include aqueous ammonia, ammonium salts, and amines; substances that chelate with copper ions include polyaminocarboxylic acid salts such as ethylenediaminetetraacetate, oxycarboxylic acids such as citric acid, and condensation Examples include phosphates, and any of these substances can be selected and used. The content of these compounds in the treatment solution is preferably 20 to 500 g/(particularly preferably
50 to 400g/), and the film formed with a treatment solution containing less than 20g/g/) may have insufficient patina.
Or, it will not progress much. 500g/
Although a film formed with a treatment liquid having the above content is sufficiently patinaed, the adhesion tends to decrease because the content of the water-based resin must be reduced. Next, examples of methods for applying the treatment liquid according to the present invention include roll coater application, air knife method, curtain flow coater method, etc., but these methods are not particularly specified. Any coating method may be used as long as it can uniformly coat the surface of the alloy with a treatment liquid in an amount of 5 to 30 g/m ² . When the dry adhesion amount is less than 5 g/m ² , patina formation is difficult to occur, and when it is over 30 g/m ² , the adhesion of the formed patina film tends to decrease, resulting in higher costs due to increased processing solution consumption. This is undesirable because Examples of forced drying means include means using hot air or an infrared lamp. These means are
Although not specific, the drying conditions are usually
100 to 200℃ (60 as the plate temperature of copper or copper alloy coated plate)
The process is carried out under the conditions of fixing and drying at a temperature of ~130°C). In addition, as the green-blue color promotion treatment in the present invention,
The main point is to apply moisture as uniformly as possible to the dry film obtained in the above treatment and cause it to quickly react with the copper or copper alloy surface, and the method is to spray water and/or steam onto the coated plate. , or a method in which the coated plate is exposed to a high humidity atmosphere is preferred. In the method of spraying water in the form of a mist, it is desirable to spray the mist as finely and uniformly as possible. Color development is promoted when the ambient temperature is high to a certain extent, but when considering processing costs, room temperature to 80°C (especially preferably about 30 to about 60°C) is appropriate, and in order to maintain a constant color tone. It is preferable to keep the temperature as constant as possible. The spray amount is about 1 to about 12 ml/m ² /min (especially preferably about 2 to 5 ml/m 2 /min).
ml/m ² /min) is appropriate, approximately 1ml/m ² /min
If it is less than 12 ml/m 2 /min, it will take too much time to develop the color (greenish-blue color) or uneven shading will occur, and if it exceeds about 12ml/m ² /min, the quality of the green-blue film will deteriorate due to uneven flow of greenish-blue color. Undesirable. The spraying time of water and/or steam is approximately 5 to 60 minutes (particularly preferably approximately 20 to 40 minutes), which is suitable for practical use and productivity. It is better to do it over a certain period of time. In the method of exposing the coated surface to a high humidity atmosphere to turn it greenish-blue, the coated surface is exposed to an atmosphere of room temperature to about 80°C (especially preferably about 30 to about 60°C) and relative humidity of 90% or more for about 30 to about 120 minutes. is preferable from a practical standpoint. The copper or copper alloy material that has been subjected to the above accelerated treatment is dried as is or washed with water and then dried.
Either natural drying or forced drying may be used as the drying method, but since changing the drying conditions will cause a subtle change in the green-blue color tone, it is necessary to select the drying conditions and maintain them within a constant range as much as possible. For industrial production, forced drying is preferred. The forced drying temperature is usually about 100 to about 200℃ (approx.
80 to about 130°C). [Function] The film formed on the surface of copper or copper alloy by the treatment liquid used in the present invention has air permeability and water permeability, so it can be formed into a green-blue film in the treatment process of the present invention. . In other words, when the accelerated treatment is performed after applying and drying the treatment liquid, water penetrates into the film and dissolves the color-forming components present in the film, that is, substances that form complex salts and chelate compounds with copper ions. The aqueous solution containing this color-forming component ionizes copper on the surface, forms a copper complex salt and a copper chelate compound with the ionized copper, and develops a green-red color. Although these are soluble, the basicity of the film further progresses due to drying after coloring treatment and the action of moisture in the atmosphere, carbon dioxide gas, etc. over time, resulting in a stable patina film. The patina film thus formed has excellent adhesion due to the bonding action of the resin component and chelate component in the film, and has a uniform, calm appearance resembling natural patina. If necessary, a clear coat can be applied to the resulting patina film to further strengthen and protect the surface. EXAMPLES Examples of the present invention will be shown below together with comparative examples to specifically explain the effects of the present invention. Example 1 (1) Compounds used in the preparation of treatment liquids The compounds used in the preparation of treatment liquids used in the examples and comparative examples of the present invention are as follows. Compounds that form complex salts with copper ions Ammonium chloride (first class reagent) Ammonium carbonate (first class reagent) Compounds that form chelate bonds with copper ions Tetrasodium ethylenediaminetetraacetate (EDTA-4Na, first class reagent) Water-based resin Phthalkyd W-760A Resin solid content 47 %
(Alkyd emulsion, manufactured by Hitachi Chemical Co., Ltd.) (2) Preparation of treatment liquid Add the calculated amount of copper complex-forming compound and copper chelate-forming compound to an appropriate amount of water, stir well, and add this aqueous solution or water. A calculated amount of water-based resin was added to the suspension, water was further added to bring the total volume to 1, and the mixture was further stirred to prepare a treatment liquid. Table 1 shows the composition of the treatment liquid used in the Examples and Comparative Examples of the present invention. (3) Test plate Copper plate for roofing material, plate thickness 0.35m, dimensions 70mm x 150mm (4) Processing method Test plate was cleaned using Perco Cleaner N364S (Alkali cleaner manufactured by Nippon Parkerizing Co., Ltd.) 20
After spray cleaning at 60°C for 1 minute, wash with water, drain and dry. Next, the treatment solution was applied to the test plate at a rate of 40 ml/m ² using a grooved rubber roll coater, and immediately forced drying was performed at 120° C. for 30 seconds. next,
The coated plate was sprayed in an atmosphere at a temperature of 40° C. for 30 minutes (spray amount 2 ml/m ² /min), and then force-dried at 120° C. for 30 seconds. Table 2 shows the results of the green-blue color development and adhesion. Test method and evaluation method Green-blue coloring property Visual observation ◎...The entire surface is uniformly colored and has a subdued green-blue color. ○...There are some areas where the green-blue color is slightly uneven. ▲…Appearance between ○ and △. △...Pale or uneven green-blue color. ×: Significant discoloration compared to green-blue. Adhesion test After color development, the test plate is coated with the same thickness as the test plate (0.35
Stack 4 sheets of mm) and fold them so that they are sandwiched together. Then, the state of peeling of the film at the bent portion was visually observed. ◎...No peeling at all. ○...There are some parts that are slightly peeled off. △...There is a part where about half of the film peels off. ×…Full surface peeling.

【table】

[Table] Comprehensive comparison of Examples and Comparative Examples in terms of green-blue color development and adhesion shows that Examples are clearly superior. When promoting patina treatment, the effects of the copper complex-forming compound, the compound that chelates with copper, the aqueous resin with adhesive function, and the addition of moisture may combine to produce a uniform product with a subdued color tone in a short period of time. A verdigris film with good adhesion can be formed. On the other hand, in the comparative example, the applied treatment liquid did not contain a water-based resin with a film adhesion function, so the adhesion was significantly inferior. In addition, in Comparative Example 1-3, the total amount of the copper complex-forming compound and the chelate-forming compound was insufficient in the treatment solution applied thereto, so although the adhesion was excellent, there was hardly any slight patina formation. Ta. Example 2 Table 3 shows the conditions and results of examining the effect of promoting patina color development on a copper plate treated by the coating method of Example 1 using the treatment liquid 1-4 of Example 1. The test method and evaluation method are the same as in Example 1.

[Table] From the results in Table 3, it can be seen that when the Examples and Comparative Examples are compared, the Examples exhibit superior green-blue color development. That is, while the patina is promoted by supplying moisture to the film under the conditions shown in the examples, in the case of the comparative example, when the moisture supply is insufficient, the patina coloring is insufficient; When there is a large amount, the color develops into a greenish-blue color, but the appearance is inferior. [Effects of the Invention] As explained above, the method of promoting the formation of a patina film according to the present invention involves spraying water and/or steam for 5 to 60 minutes after forming a film containing a water-based resin, or spraying water and/or steam at a relative humidity of 90%. The film develops a greenish-blue color by exposing it for 30 to 120 minutes, so the film is 5g/
Even if it is more than m ² , it has the excellent effect of being able to efficiently form a uniform patina film with excellent adhesion and a subdued color tone on the surface of copper or copper alloy in a short time. Furthermore, if a roof is led using a copper plate treated with the method according to the invention,
Since it has a greenish-blue appearance with a uniform and calm tone from the beginning, it has the advantage of being excellent in terms of quality and industrial productivity.

Claims (1)

[Claims] 1. 10 to 300 g of water-based resin as solid content,
The total amount of compounds that form complex salts with copper ions and compounds that chelate with copper ions is 20 to 500.
An aqueous solution or aqueous suspension containing g/ is used as a treatment liquid,
This is applied to the surface of clean copper or copper alloy, the coated surface is force-dried to form a film of 5 to 30 g/ ^m2 , and then water and/or steam is applied to the coated surface for 5 to 30 g/m2.
A method for promoting the formation of a green-blue film, which comprises spraying for 60 minutes to develop a green-blue color, and then drying the coated surface. 2 50 to 300 g/solid content of water-based resin,
The total amount of compounds that form complex salts with copper ions and compounds that chelate with copper ions is 50 to 400.
The method for promoting the formation of a verdigris film according to claim 1, wherein the treatment liquid is an aqueous solution or suspension containing g/. 3. The method for promoting the formation of a verdigris film according to claim 1, which comprises spraying water and/or steam in an atmosphere at room temperature to 80°C. 4 Spray water and/or steam at a rate of 1 to 12 ml/m ² /
2. The method for promoting the formation of a verdigris film according to claim 1, which is carried out at a rate of min (amount of spray per minute per 1 m square, in the case of water vapor, its water equivalent value). 5 10 to 300 g of water-based resin as solid content,
The total amount of compounds that form complex salts with copper ions and compounds that chelate with copper ions is 20 to 500.
An aqueous solution or aqueous suspension containing g/ is used as a treatment liquid,
Apply this to the surface of clean copper or copper alloy, force dry the coated surface to form a film of 5 to 30 g/ ^m2 , and then place the coated surface in an atmosphere at room temperature to 80℃ and relative humidity of 90% or more. 1. A method for promoting the formation of a green-blue film, which comprises exposing the coated surface for 30 to 120 minutes to develop a green-blue color, and then drying the coated surface. 6. The method for promoting the formation of a verdigris film according to claim 5, which is exposed to an atmosphere of 30 to 60°C and a relative humidity of 90% or more to develop a greenish-blue color.