JPS6219910B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for 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. [Prior Art] Many patent applications have been filed to date for methods of industrially forming a green-blue film on the surface of copper or copper alloy products, especially copper plates for building materials used as roofing materials. , methods of treating with chemicals, i.e., chemical conversion treatment methods, electrolytic treatment methods with chemical solutions, methods of chemical conversion treatment and further painting, methods of painting with paints containing green-blue-forming substances, and copper surfaces whose surface has been roughened by sandblasting etc. Examples include a method in which a copper powder or copper alloy powder is bonded to the surface using an adhesive, and then a treatment liquid having a patina effect is applied to form a patina film.
As a method that corresponds to the above method,
110235, 122637, Japanese Patent Application Publication No. 1983-
1223638, JP 55-8490, JP 56-9270, JP 56-30396 and JP 57-51468, etc., but in all of these methods, drying after treatment is done by natural drying or Since it is necessary to repeatedly perform treatment and drying, there are problems such as not only the rate of generation of patina is slow but also the adhesion of the patina film is not good, which is not necessarily suitable for quality or industrial production. . As a method that falls under the above method,
-122641, Special Publication Showa 55-12117, Special Publication Showa 55-14157,
Examples include Japanese Patent Publication No. 55-15558 and Japanese Patent Application Laid-open No. 57-177997, but although it is possible to generate patina on the copper surface in a short time during the treatment process using an electrolytic method, the formed green-blue film is easy to peel off. However, there are other problems such as difficulty in managing the electrolyte and the need for a large amount of capital investment. As a method that falls under the above method,
-8491 and JP-A-56-13483, etc., but they have the problem that it is difficult to stably form a green-blue film. Tokuko Sho 55- as applicable to the above method
139467, but it has the problem that the adhesion of the green-blue film is not good. As applicable to the method of
693575 and Japanese Patent Publication No. 57-52425, etc., but both methods require a large number of steps to form a green-blue film and have problems in terms of productivity and processing cost. [Object of the Invention] The present invention has been made with the aim of eliminating the above-mentioned problems or drawbacks, and it is a method of imparting patina to the surface of copper or copper alloys, particularly copper plates for building materials used as roofing materials. After forming an organic film containing a promoting compound, it is coated with an organic resin paint containing a green-blue pigment and an extender pigment that imparts breathability and water permeability. The object of the present invention is to provide a novel method for forming a green-blue film that is excellent in terms of industrial production, in which a green-blue film with uniform and subdued color tone and good adhesion can be obtained by exposing the film to the outdoors. [Structure of the present invention] The present invention, which has been made to achieve the above object, provides an aqueous solution or aqueous suspension containing an aqueous resin, a compound that forms a complex salt with copper ions, and/or a compound that chelates with copper ions. As a processing liquid,
After applying it to a clean copper or copper alloy surface and immediately forcing it to dry, an organic resin paint containing a green-blue pigment and an extender pigment that provides air permeability and water permeability is applied on top of the paint film. Consists of forced drying. The water-based resin used in the treatment liquid used in the present invention may be either water-soluble or water-dispersible, and commonly used resins include acrylic, alkyd, urethane, and polyester resins. Examples include resin compositions. The resin content in the processing liquid is 10 to 300 as solid content.
g/(preferably 50 to 300 g/). Ten
If a treatment liquid of less than g/g is applied, the adhesion of the film will be poor. Regarding the treatment liquid with a solid content of 300 g/or more, it was not possible to prepare the treatment liquid because the solid content of all the water-based resins used in the examples of the present invention was lower than 50%.
However, if it is possible to prepare a processing solution containing 300g/or more of solids, it is possible to add a large amount of a copper complex-forming compound and/or a compound that chelates with copper ions to the processing solution and use it. It is presumed that the object of the present invention can be achieved even in this case. Compounds that form complex salts with copper ions include aqueous ammonia, ammonium salts, amines, etc. Compounds that form chelate bonds with copper ions include polyaminocarboxylate salts such as ethylenediamine tetracomplex salts, and oxycarboxylic acids such as citric acid. and condensed phosphates, and any compounds selected from these compounds can be used. The content of this compound in the treatment liquid is 10 to 500 g/(preferably 50 to 400 g/), and if the content is 10 g/or less, the film formed with this treatment liquid will not have a patinaing effect when exposed outdoors. If the amount is 500g/ or more, the coating formed with this treatment solution will undergo satisfactory patinaing when exposed outdoors, but the adhesion of the coating to the copper or copper alloy surface will be poor. decreases. Next, as a method of applying the treatment liquid, for example, roll coater coating, air knife method, etc. can be mentioned, but the method is not limited to these methods.
Any coating method may be used as long as it can be applied uniformly so that the coating amount is 0.5 to 5 g/m ² . dry adhesion amount
If it is less than 0.5 g/m ² , it is difficult to develop a patina when exposed outdoors, and if it is more than 5 g/m ² , the permeability of rainwater, carbon dioxide, etc. I'm getting old. Next, examples of forced drying means include methods using hot air or infrared rays. Although the drying conditions are not specified, the drying is usually carried out at 100 to 150°C under conditions of tack-free drying. In the method of the present invention, an organic resin paint containing a green-blue pigment and an extender pigment that imparts air permeability and water permeability to the coating film is applied on top of the film (lower layer film) formed by applying the treatment solution as described above. Then, a greenish-blue organic resin film (upper layer film) having air permeability and water permeability is formed. The green-blue pigment can be arbitrarily selected from organic pigments such as phthalocyanine green and phthalocyanine blue, and inorganic pigments such as natural green-blue and titanium white, and the color can be adjusted by blending them. The amount of the pigment to be blended depends on the desired green-blue color tone, shade of color, etc., and is not specified in the present invention. Further, as an extender pigment that imparts air permeability and water permeability to the coating film, for example, silica can be mentioned, and the amount of the extender pigment added to the resin is preferably 1 to 10% by weight. If it is less than 1%, the upper layer coating will have poor air permeability and water permeability, and
If more than 10% is added, the adhesion of the upper layer film to the lower layer film will deteriorate significantly, making it unsuitable for practical use. Next, examples of the organic resin include acrylic resin, alkyd resin, polyester resin, polyurethane resin, etc., and any organic resin can be selected from these organic resins. Further, the organic solvent is selected from those that dissolve the resin. The organic paint made with the above structure is applied onto the lower layer coating by a roll coater method or other methods, but it is recommended to apply it so that the dry coating amount is 5 to 50 g/ ^m2 . preferable. If it is less than 5 g/m ² , the greenish-blue color of the upper layer film will be insufficient, and if it is more than 50 g/m ² , the air permeability and water permeability of the upper layer film will be reduced, thereby delaying the patina of the lower layer film. In addition, it is preferable to dry the upper layer film by force drying using hot air or infrared rays at a temperature of 100℃ to 150℃.
Free). Copper or copper alloys coated by the method of the present invention, particularly copper plates for building materials used as roofing materials, are exposed outdoors. [Function] The film formed on the surface of copper or copper alloy by the method of the present invention has a green-blue color tone due to the upper layer film at the time of film formation, and when exposed outdoors, this film has a greenish-blue color tone. Rainwater and carbon gas in the air reach the lower layer film through the upper layer film, and then reach the metal surface through the lower layer film, where they ionize copper from the metal surface. These copper ions combine with complex salt-forming compounds and/or chelate-binding substances in the lower film to form copper complex salts and/or copper chelate compounds, and these substances turn green when exposed to the action of rainwater and carbon dioxide gas. . The role of the water-based resin in the lower layer coating is to adhere the lower layer patinaing substance to the metal surface, and therefore serves as a binder that maintains the adhesion of the lower layer coating as a patina coating. The role of the upper film is to maintain a greenish-blue appearance from the time it is coated until it deteriorates over time and peels off due to outdoor road conditions. That is, when the upper layer film is exposed outdoors, rainwater, carbon dioxide gas, etc. permeate through it, promoting the patina of the lower layer film, and on the other hand, it deteriorates over time, causing cracks in the film and gradually peeling off. After that, the appearance is maintained by the lower layer coating, that is, the patina coating with uniform adhesion and a subdued color tone. Thus, according to the method of the present invention, the appearance can be maintained in a greenish-blue color from the beginning of coating, and after it has peeled off due to long-term outdoor exposure, the appearance can be maintained by the adhesive greenish-blue film below. Examples of the present invention are shown below along with comparative examples. [Example] (1) Compounds used to prepare the treatment solution 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.) Primal HA-8 resin solid content 45.5% (Acrylic amulsion, Roan & Haas Japan Co., Ltd.) Bonditsuku 1010C resin solid content 40% (urethane emulsion, manufactured by Dainippon Ink & Chemicals Co., Ltd.) (2) Preparation of treatment liquid Add the calculated amount of copper complex-forming compound and/or copper chelate-forming compound to an appropriate amount. After adding it to water and stirring well, a calculated amount of water-based resin was added to the aqueous solution or 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.

〔Effect of the invention〕

As the above test results are shown in Table 2,
Comprehensive comparison of Examples and Comparative Examples in terms of patina generation of the lower layer film, adhesion of the film, and adhesion of the film after outdoor exposure showed that the Example clearly outperformed the other, demonstrating the effect of the present invention. I was able to confirm this. That is, the film formed by the method of the present invention on the surface of copper or copper alloys, particularly copper plates for building materials used as roofing materials, has a greenish-blue appearance from the beginning of coating, and this changes due to long-term outdoor exposure. While the blue-colored upper layer deteriorates and cracks and peels off naturally, moisture and carbon dioxide that permeate through the upper layer and reach the metal surface form copper ions from the metal surface, and these ions It acts with the complex salt-forming substance and/or the chelate-binding substance in the lower layer film to form a copper complex salt and/or a copper chelate compound, respectively, and furthermore, these compounds turn into green blue and combine with the binding action of the water-based resin to provide adhesiveness.
In addition, it forms a patina film with a uniform and calm green-blue color and maintains it stably. Therefore, in the film formed by the method of the present invention, the green-blue appearance is maintained by the green-blue upper layer film at the beginning of coating, and the green-blue appearance of the lower layer film is completed by the time the upper layer film deteriorates due to outdoor exposure. However, the green-blue film maintains the green-blue color even after the upper layer film deteriorates and flakes off, and has an excellent effect that is extremely favorable in terms of industrial productivity and quality.

【table】

Claims (1)

[Claims] 1. An aqueous solution or aqueous suspension containing an aqueous resin, a compound that forms a complex salt with copper ions, and/or a compound that forms a chelate bond with copper ions is used as a treatment liquid, and this treatment liquid is used as a treatment liquid for clean copper or copper. After applying it to the surface of the alloy and forcing the paint film to dry, an organic resin paint containing a green-blue pigment and an extender pigment that gives air permeability and water permeability to the paint film is applied on top of the paint film. A method for forming a green-blue film, characterized by comprising forced drying. 2 The content of water-based resin in the treatment liquid is calculated as solid content.
10 to 300 g/, and the total content of compounds that form complex salts with copper ions and/or compounds that chelate with copper ions is 10 to 500 g/. Formation method.