JP2583305B2 - Roofing material that forms patina early - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a roofing material used for construction, and is one in which patina is formed early.

[Conventional technology]

Many of the roofs, exteriors, and art ornaments of buildings such as shrines, temples, and houses are formed using copper or a copper alloy, or have a surface plated with copper. This is because copper has excellent weather resistance, is hard to corrode, and can withstand long-term use.In particular, copper has a patina on the surface, which gives the copper product a heavy and calm feeling. This is why copper is preferred as a roofing material and artwork for buildings.

By the way, patina is naturally generated by exposing a copper product to the atmosphere, but its growth rate is extremely slow, and generally takes several years or more to form a desired film. It is.

For this reason, conventionally, a method of artificially generating patina by cleaning a copper product with an inorganic acid such as sulfuric acid, nitric acid or hydrochloric acid, temporarily eroding the surface, and treating the surface with sodium carbonate or the like. Attempted. However, the patina film produced by this method has the drawbacks that it is extremely thin, produces color unevenness, has low productivity, and requires a large-scale wastewater facility.

Therefore, as a measure to eliminate such a defect, a method of applying a paint using a copper compound of basic copper carbonate, copper sulfide or copper oxide instead of patina on the surface of a copper product has been attempted. However, this method has much higher productivity than the above surface treatment method, but on the other hand, these coatings have very low weather resistance.For example, when this is used for a copper roof, etc., within one year, There was a drawback that the paint was peeled off and the appearance was extremely ugly.

[Means for solving the problem]

In view of this, as a result of various studies, the present invention has developed a roof sheet material that accelerates the growth rate of patina generated on the surface of Cu or Cu alloy and forms patina at an early stage when patina naturally occurs in the short term. It is.

That is, the present invention is characterized in that the surface roughness (Ra) of at least one surface of the roofing sheet material made of Cu or Cu alloy is 0.10 μm or more.

[Action]

In the process of producing patina in the natural world, patina is generated when CO ₂ and SO ₂ in the atmosphere dissolve in the dew condensation water condensing on the copper roof shingle surface during rainfall and high humidity and corrode copper. .

When this condensed water adheres to the surface of the roof shingle, if the surface is smooth, it is difficult for rainwater or the like to be trapped, and the water quickly flows down or evaporates and dries in a short time.
Since copper is left in the corrosive environment for a short time, and hence the progress of the corrosion reaction is slow, it takes a very long time to develop patina.

Therefore, the present invention roughens the surface of the copper roof shingle to prevent rainwater from flowing down, and makes the hardened surface harder to dry because the roughened surface has a lower equilibrium water vapor pressure than the flat surface due to capillary action. Furthermore, on the roughened surface, dew condensation occurs at a lower humidity than on the flat surface, and since the roughened surface is much wetted for a longer time, green-blue is generated very early.

As a method of roughening, any method such as a dry buff, a wet buff, a shot blast, and a wet brush may be used.

The reason for setting the level of the surface roughness (Ra) to 0.10 μm or more is that when Ra <0.10 μm, the formation of green and blue is not substantially accelerated.

〔Example〕

Next, examples of the present invention will be described, but the present invention is not limited thereto.

First, copper roof plate materials No. 1 to No. 4 as shown below were manufactured.

<Roof slab material No.1 of the present invention> A phosphorous deoxidized copper plate (Ra = 0.05 μm) with a thickness of 0.45 mm
280 emery paper was applied and wet rotary polishing was performed for 15 minutes to Ra = 0.12 μm.

<Roof sheet material No.2 of the present invention> A phosphorous deoxidized copper sheet (Ra = 0.05μm) with a thickness of 0.45mm
100 wet emery papers were applied, and wet rotary polishing was performed for 15 minutes to obtain Ra = 0.23 μm.

<Roof plate material No. 3 of the present invention> A long line of a 0.45 mm-thick phosphor-deoxidized copper plate (Ra = 0.05 μm) was buffed with a # 800 buff on its surface by a production line that continuously performs pickling and buffing. Was used to process at a line speed of 20 m / min and a buff rotation speed of 1200 rpm to Ra = 0.25 μm.

<Comparative roof slat No. 4> Phosphorus deoxidized copper plate (Ra = 0.05μm) with a thickness of 0.45mm #
600 wet emery papers were applied, and wet rotary polishing was performed for 15 minutes to make Ra = 0.08 μm.

Thickness of the above roof shingle material without buffing etc.
Along with the comparative roof slat No. 5 consisting of a phosphorous deoxidized copper plate of 45 mm and Ra = 0.05 μm, it was exposed to coastal areas and mountainous areas to investigate the state of patina, and the results are shown in Table 1.

As is clear from Table 1, the roof sheet materials No. 1 to N of the present invention
In all o.3, patina was generated earlier and more uniformly than comparative roof slats No.4 and No.5, each of which had a small surface roughness.

〔The invention's effect〕

As described above, according to the present invention, a remarkable industrial effect is exhibited, such as the ability to generate uniform patina quickly and entirely on the copper roof slab.

Claims (1)

(57) [Claims] 1. A roof sheet material in which patina is formed at an early stage, characterized in that at least one surface roughness (Ra) of the roof sheet material made of Cu or Cu alloy is 0.10 μm or more.