JPS62253775A - Method for accelerating formation of patina film and treating liquid - Google Patents

Abstract

PURPOSE:To acceleratedly form a patina film having fine appearance and superior adhesion by coating the surface of copper with a treating liq. contg. an aqueous resin, a compound forming a complex salt with a copper ion, a compound causing a chelate bond to a copper ion, an alkali metallic salt and silica and by spraying water on the coated surface. CONSTITUTION:A treating liq. is prepd. by adding 10-300g/l (expressed in terms of solid matter) aqueous resin such as acrylic resin composition, 40-500g/l in total of a compound forming a complex salt with a copper ion, e.g., NH4OH, a compound causing a chelate bond to a copper ion, e.g., EDTA and an alkali metallic salt such as NaCl and 5-40g/l silica. The clean surface of copper or a copper alloy is coated with the treating liq. by 5-30g/m<2> (expressed in terms of a dry film) and the coated surface is forcedly dried. Water and/or steam is then sprayed on the coated surface in an atmosphere at ordinary temp.-80 deg.C at 1-12ml/m<2>/min rate for 5-120min. The coated surface may be exposed to an atmosphere at ordinary temp.-80 deg.C and >=90% relative humidity for 30-120min. Thus, the coated surface is allowed to uniformly develop a bluish green color in a relatively short time and finally the surface is dried.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for relatively quickly forming a green-blue film industrially on the surface of copper or copper alloy products, particularly copper plates for building materials used as roofing materials. This article relates to a method for making this happen.

[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. ■Medicinal treatment method, i.e. chemical conversion treatment method;■
Electrolytic treatment with chemicals, ■ Chemical conversion treatment and further painting, ■ Painting with a paint containing a greenish-blue forming substance, and ■ Applying copper powder or copper alloy powder to a copper surface whose surface has been roughened by sandblasting etc. Examples include a method of bonding with an adhesive and then applying a treatment liquid having a patina effect to form a patina film.

As a method corresponding to the above method (■),
0235, JP-A-53-122637, JP-A-53-1
22638, Japanese Patent Publication No. 55-8490, Special Publication No. 56-92
70, Special Publication No. 56-30396 and Special Publication No. 57-514
68, etc. However, in both methods, the drying after treatment is done by natural drying, so the color development tends to vary depending on seasonal factors, such as outside temperature and humidity, or it is necessary to repeat the treatment and drying. Because of this, not only is the rate of green-blue color development slow, but the green-blue film tends to be uneven, and there are problems such as poor adhesion, which is not necessarily suitable in terms of quality or industrial production.

As a method that corresponds to the above method (■),
641, Special Publication No. 55-12117, Special Publication No. 55-14
157, JP 55-15558, and JP 57-
177997, etc., but while it is possible to generate patina on the copper surface in a short time during the treatment process by electrolytic method, the formed patina film is easy to peel off.
It also has problems such as requiring a large amount of capital investment.

JP-A No. 55-8491 as applicable to the method of
, JP-A-56-13483, etc., but they have the problem that it is difficult to stably form a patina film.

JP-A No. 55-1394, which corresponds to the method of
No. 67 is mentioned, but it has the problem that adhesion deteriorates due to chalking of the coating film due to age of the patina film.

Japanese Patent Application Laid-open No. 56-6937 as applicable to method (■)
5 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 of the present invention have investigated and developed a patina film-forming treatment solution having an exposed area that promotes patina formation, and after applying and drying the treatment solution, the coating film can be formed in a shorter time. The present invention has been completed by discovering a method for promoting patina formation in which a uniform and adhesive patina film is formed on the surface of the substrate.

[Purpose of the Invention] The present invention was made with the aim of eliminating the above-mentioned problems and satisfying the needs. After applying it to the surface and forcing it to dry, spray water and/or steam onto the coated surface in an atmosphere controlled at a constant temperature, or expose the coated surface to a relative humidity of 90% or more to create a greenish-blue color. After coloring and drying, in other words, in the above surface treatment process, a patina film with excellent appearance and adhesion is formed without being affected by outside temperature and humidity, making it a new industrially productive product. Extremely good for
The present invention aims to provide a method for forming a patina film that closely matches natural patina.

[Structure of the Invention] The present invention, which has been made to achieve the above object, comprises a verdigris film forming treatment liquid (hereinafter referred to as treatment liquid) and an accelerated treatment method using the treatment liquid.

That is, the solid content of water-based resin is 10 to 300 s/l, and the total amount of compounds that form complex salts with copper ions, compounds that chelate with copper ions, and alkali metal salts is 4.
0 to 500 g/l and further 5 to 409 g/l of silica.
After applying the treatment solution containing fl and the treatment solution to the surface of clean copper or copper alloy and forcing the coated surface to dry, the coated surface is sprayed with water and/or steam to develop color, or the coated surface is By exposing it to an atmosphere with a relative humidity of 90% or more to develop color and then drying the coated surface, it has an excellent appearance with a uniform and subdued color tone close to natural verdigris on copper or copper alloy, and has excellent adhesion. It consists of a treatment method that can form an excellent green-blue film.

[Description of composition and conditions 1 The water-based resin contained in the treatment liquid used in the present invention is as follows:
It can 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 300 g/l, particularly preferably 50 to 20 g/l as a solid content.
0g/l).

A patina film formed with a treatment liquid containing less than 10 g/l has poor adhesion. In addition, since the solid content of the aqueous resin used in the examples of the present invention was lower than 50%, it was not possible to perform IIfJ on the treatment liquid containing more than 300 g/J, so the performance could not be confirmed. This is not preferable because it increases the cost.

Substances that form complex salts with steel ions include ammonia water,
There are ammonium salts, amines, etc., and ethylenediaminetetraacetic acid IIM is a substance that chelates with copper ions.
Examples include polyaminocarboxylic acid salts such as A, oxycarboxylic acids such as citric acid, and condensed phosphates, and any of these substances can be selected and used.

Also, as an alkali metal salt, hydrochloric acid,! Examples include sodium, potassium, and lithium salts of the acid, acetic acid. The content of these compounds in the treatment solution is preferably 40 to 500
g/l1, particularly preferably 100 to 4009/l
It is. If the treatment liquid has a content of less than 409/l, the amount of dry film obtained by coating will be small, and the patina will be insufficient or will not progress much. A treatment solution with a content higher than 4009/j has the ability to sufficiently turn the film into a patina, but as a prerequisite for this, the content of the water-based resin must be reduced, which results in a decrease in adhesion. Undesirable. As the silica, commercially available colloidal silica or finely powdered silica can be used. The content of silica is preferably 5 to 40 g/l, particularly preferably 10 to 3
If it is less than 5 g/l, the uniformity when applying the treatment liquid will decrease, and if the treatment liquid contains more than 409/9, the adhesion of the film will decrease, so it is not preferable in any case. .

Next, methods for applying the treatment liquid according to the present invention include, for example, spray coating, roll coater coating, 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 so that the dry adhesion amount of the treatment liquid is 5 to 309/m.

When the dry adhesion amount is less than 5 g/yd, patina formation is difficult to occur, and when it is more than 30 g/lyl, the adhesion of the formed patina film decreases and the consumption of processing solution increases, resulting in poor performance. This is unfavorable both in terms of performance and cost.

Examples of forced drying means include hot air or infrared rays. Although these methods are not specified, the drying conditions are usually 100 to 200°C (60°C as the plate temperature for copper or copper alloy coated plates). The drying process is carried out at a temperature of 130° C. to 130° C. for fixation and drying.

In addition, the green-blue color formation promotion treatment method in the present invention includes:
The main point is to apply moisture as uniformly as possible to the dry film obtained in the above treatment and to react with the surface of the copper or copper alloy immediately.This method involves spraying water in the form of mist or steam onto the coated plate. A method of exposing the dried film to a humid 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 if processing costs are considered, room temperature to about 8
A temperature of 0° C. (particularly preferably about 30 to about 60° C.) is suitable, and in order to keep the color tone constant, it is preferable to keep the temperature as constant as possible. Also, the amount of spray is 1-12! ! IIl/
TIi/1n (particularly preferred about 2 to about 5 dll r
d/1n) is suitable; if it is less than 1 xi/yd/Sin, it takes too long for color development (greenish-blue) and unevenness in greenish-blue shading tends to occur. Moreover, if it exceeds 12M1/TIt/1n, uneven color flow occurs, which deteriorates the quality of the patina film after drying, which is not preferable. Processing time is approximately 5
~120 minutes, particularly preferably about 20 to 60 minutes) is suitable for practical and productive purposes.Actually, it is preferable to appropriately select the treatment time depending on the green-blue condition and carry out the treatment over a certain period of time. Next, the method of exposing the coated surface to a high humidity atmosphere is from room temperature to about 80°C (especially preferably about 30 to about 60°C).
℃), about 30 to about 120 in an atmosphere with a relative humidity of 90% or more.
From a practical point of view, it is preferable to expose the solution separately.

The copper or copper alloy material that has been subjected to the above acceleration treatment is either dried as is or washed with water and then dried.

The drying method may be either natural drying or forced drying, but
Changes in drying conditions cause subtle changes in the green-blue color tone, so it is necessary to select drying conditions according to the color tone and maintain the conditions within a constant range as much as possible. However, forced drying is preferred for industrial production.

The forced drying temperature is usually preferably about 100 to about 200°C (about 80 to about 130°C as the temperature of the treated plate).

A clear coat may also be applied on the resulting patina film to further strengthen and protect the surface. The clear coating agent may be a commonly used water-based, solvent-based, or resin-based one, and is not particularly limited thereto.

[Function] The treatment liquid of the present invention can form a green-blue film by being exposed to supination for about one month after being applied and dried, so it itself has the function of promoting green-blue color. However, the present invention also includes a method of accelerating the formation of patina during the treatment process. That is, the film formed by applying the treatment liquid to the surface of clean steel or copper alloy and forcing it to dry has air permeability and water permeability, so this coating film is coated with the patina promoting treatment of the present invention. That is, water and/or water vapor spray or room temperature to about 80°C, relative humidity about 9
By exposing to an atmosphere of 0% or more, a verdigris film can be formed in the process of promoting the formation of a verdigris film in the present invention. In other words, when accelerated treatment is performed after applying and drying a treatment liquid, moisture penetrates into the film, and the components present in the film that develop a greenish-blue color, i.e., compounds that form complex salts with copper ions, copper ions. Dissolve the compound and alkali metal salt that chelate with. 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 greenish-blue color. At this time, alkali metal salts play a role in promoting this reaction. These substances are soluble, but due to drying after coloring treatment and over time, insoluble PAN
Copper chloride progresses to form a stable patina film. The patina film thus formed is uniform and has excellent adhesion, combined with the adhesion-improving effect of coatings such as resin, silica, etc., and becomes a patina film that approximates a settled natural patina. Furthermore, the resulting patina film can be further strengthened and protected by further applying a clear coat on top of the patina film.

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 (reagent-grade) Ammonium carbonate (reagent-grade) ・Compounds that form chelate bonds with copper ions: Tetrasodium ethylenediaminetetraacetate (E (lTA-4Na, reagent-grade) ・Water-based resins Phthalkyd +4-76OA 4 After adding the copper complex-forming compound and copper chelate-forming compound of the W4 calculator to an appropriate amount of water and stirring well, disperse the silica, add the calculated amount of water-based resin to this water suspension, and then add water. The total volume was adjusted to 11, and the treatment solution was prepared by further stirring.Table 1 shows the composition of the treatment solution used in the examples and comparative examples of the present invention.

(3) Test plate Copper plate for roofing material Plate thickness 0.357FL Dimension 7 (IJIIIX 150trm) (4) Processing method Spray the test plate with Barco Cleaner-83643 (Alkali cleaner manufactured by Nippon Bar Ising) 209/J at 60°C for 1 minute After washing, rinse with water, drain and dry.

Next, the treatment solution was applied to the test plate using a grooved rubber roll coater for 40 minutes.
Immediately after applying d/d, heat to 11i at 120℃ for 30 seconds.
It was dried for 1J. Next, the coated plate was subjected to water spray N (spraying method: 2d/i/m1n) at an ambient temperature of 40°C for 30 minutes, and then forcedly dried at 120°C for 30 seconds.

Table 2 shows the results of the uniform application, green-blue color development, and adhesion of these treatment solutions.

(5) Test method and evaluation method ■ Treatment liquid applicability Visual observation O... Uniform coating appearance 〇...ya) There are uneven parts. Δ・・・Uneven parts are noticeable ×...There is uneven coating overall. ■ Patina color development Visual observation ◎...Uniform green-blue color developed over the entire surface.

O... or) There are non-uniform parts.

Δ...Color development is pale or uneven.

×: Almost no color development is observed.

■ Adhesion After color development, the test plate is stacked with four plates of the same thickness (0.35 m) as the test plate, and then bent to sandwich them. Then, the state of peeling of the film at the bent portion was visually observed.

◎...No peeling at all.

O: Slight peeling is observed.

M...Approximately 25% peeling is observed.

Δ: Approximately 50% peeling is observed.

X: Fully peeled off.

Table 2 Test Results When comparing the Examples and Comparative Examples with respect to treatment solution coating properties, green-blue color development, and adhesion, it is observed that the addition of resin improves adhesion, and the addition of silica improves coating uniformity. In the case of Example 1-5, the adhesion is 1 rank inferior to Examples 1-2 to 1-4, but this is due to the content of antimony chloride, antimony carbonate, sodium chloride, etc. as seen in Table-1. This is because there are relatively many. However, when compared comprehensively, it is clear that the example is better.

In other words, when promoting patina treatment, the phase-opening effect of a copper complex-forming compound, a copper chelate-forming compound, an alkali metal salt, an aqueous resin with an adhesive function, and silica that improves uniform coating properties, and the addition of moisture to the coated surface. The combination of these effects makes it possible to form a patina film with a calm color tone in a short period of time with uniformity and good adhesion. On the other hand, in Comparative Examples 1-1 to 1-3, the applied treatment liquid did not contain a water-based resin, so the adhesion was significantly inferior. Further, Comparative Examples 1-1 and 1-2 do not contain silica, and Comparative Example 1-5 has a very low silica content, so the uniformity during coating is poor in both cases. Next, in Comparative Example 1-4, the silica content was too high, so the adhesion was reduced. In Comparative Example 1-6, almost no green-blue color was observed because the total amount of the copper complex-forming compound, copper chelate-forming compound, and alkali metal salt was insufficient.

Example 2 A method for promoting patina color development was investigated on a copper plate treated by the coating method of Example 1 using the treatment liquid 1-4 of Example 1. Table 3 shows the conditions and results. The trial method and evaluation method are the same as in Example 1.

Table 3 From the results in Table 3, it can be seen that the examples exhibit better color development than the comparative examples. That is, while the patina is promoted by supplying moisture to the film under the conditions shown in Examples, in the case of Comparative Example 2-1, color development was insufficient due to insufficient moisture supply, and Comparative Example 2-2 In the case of , the patina film runs and becomes uneven due to too much water supply, resulting in poor appearance. In addition, in the case of Comparative Example 2-3, the green color development was extremely poor due to the low sI content in the atmosphere.

[Effects of the Invention] As explained above, the treatment method for promoting the formation of a green-blue film of the present invention and the treatment liquid used in the treatment method have a simple process for forming a green-blue film, and the formation of a green-blue film in the process. It has the excellent effect of being able to form.

Furthermore, when a roof is constructed using a copper plate treated by the method of the present invention, it is possible to obtain a roof that has a uniform and subdued green-blue color immediately after construction, and the resulting patina film has a natural patina. It also has excellent effects such as being similar and preferable in terms of quality.

Claims (9)

[Claims] (1) 10 to 300 g/l of water-based resin as solid content,
The total amount of compounds that form complex salts with copper ions, compounds that chelate with copper ions, and alkali metal salts is 40
-500g/l and 5-40g/l of silica
After applying the containing treatment liquid to the surface of clean copper or copper alloy and forcing drying, water and/or steam is sprayed onto the applied surface to develop a greenish-blue color, and then the applied surface is dried. A distinctive treatment method for promoting the formation of a patina film. (2) The method for promoting the formation of a verdigris film according to claim (1), wherein the coating amount of the verdigris film forming treatment liquid is 5 to 30 g/m^2 as a dry adhesion amount. (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 1 to 12 ml/m^
2/min (1 m square, spray amount per minute; in the case of water vapor, the same applies below its water equivalent value). (5) The method for promoting the formation of a verdigris film according to claim (1), wherein the water and/or steam is sprayed for 5 to 120 minutes. (6) 10 to 300 g/l of water-based resin as solid content;
The total amount of compounds that form complex salts with copper ions, compounds that chelate with copper ions, and alkali metal salts is 40
-500g/l and 5-40g/l of silica
After applying the containing treatment solution to the surface of clean copper or copper alloy and forcing drying, the applied surface is exposed to an atmosphere of room temperature to 80°C and relative humidity of about 90% or more to develop a greenish-blue color. A treatment method for promoting the formation of a verdigris film, characterized by drying the surface. (7) Claim No. 6, which develops a greenish-blue color by being exposed to an atmosphere of 30 to 60°C and a relative humidity of about 90% or more.
The method for promoting the formation of a verdigris film as described in 2. (8) The method for promoting the formation of a verdigris film according to claim (6), wherein the exposure time in the atmosphere is 30 to 120 minutes. (9) 10 to 300 g/l of water-based resin as solid content;
The total amount of compounds that form complex salts with copper ions, compounds that chelate with copper ions, and alkali metal salts is 40
-500g/l and 5-40g/l of silica
A verdigris film forming treatment liquid characterized by comprising: