JP2003341696A - Highly glossy aluminum alloy for use as can lid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an aluminum plate for use as a can lid which has required glossiness as a cold rolled plate without mirror-finishing such as polishing, specifically, the aluminum plate with a reflectance of 20% or higher. <P>SOLUTION: The shape and distribution of oil pits occurring on the surface of the plate by cold rolling are properly controlled. Specifically, the aluminum plate for use as a can lid with excellent glossiness has 40 oil pits/mm<SP>2</SP>with a depth of 0.6 to 1.5 &mu;m and a half width of 5 to 30 &mu;m present on the plate surface. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to a can having excellent gloss.
Excellent gloss, especially when a clear coating is applied to the lid material
Hang on the can lid material. [0002] 2. Description of the Related Art Currently, can lid materials are used by clear coating.
The aluminum plate surface can be seen through the coating film
It has become so. For this reason, the gloss of the aluminum plate surface
If bad, the clear paint film may look faint or
If it is colored, the color will look dull,
There is a problem that the appearance quality is deteriorated.
Therefore, a plate with high gloss is required. [0003] SUMMARY OF THE INVENTION High gloss aluminum
Alloys such as bright wheels for automobiles
The surface is chemically polished and further electrolytically polished, then anodized
Some are processed and mirror-finished, but large
Such mirror finish is a significant cost
Up, and the general consumer can also
Gloss is not required. Therefore, especially mirror finish such as polishing
Necessary light in the state of a cold rolled plate without applying
Those with many degrees, specifically those with a reflectance of 20% or more
Is required. [0004] Means for Solving the Problems The present inventors have made intensive studies.
As a result, oil pits formed on the sheet surface by cold rolling
Excellent reflection by properly controlling the shape and distribution of
Rate was obtained. That is, the present invention has a depth of 0.6
Oil pits of 1.5 to 1.5 μm, half width at 5 to 30 μm
40 pieces / mm on the surface²Gloss characterized by the following
It is an excellent aluminum plate for can lids. [0005] BEST MODE FOR CARRYING OUT THE INVENTION The surface of a cold rolled sheet is completely flat.
No, very rugged surface (wavelength 100 micron)
About 0.8 microns).
Loose irregularities have high reflectance when viewed macroscopically and have a metallic luster
Surface. However, on the surface of the cold rolled sheet
Is closed between the rolling roll and the sheet surface as shown in FIG.
Due to the pressure of the rolling oil, the peaks of the surface irregularities
There is a small depression called an oil pit. This o
If there is an il pit, the incident light is reflected at the same angle.
And diffusely reflected at the edges and slopes of the oil pit.
No, because of this, the metal surface deteriorated and the plate surface became cloudy
It will look like. Low luster with oil pits
It is qualitatively known that
As a result of research, it is identified among various oil pits, large and small
Size and shape greatly affect gloss reduction
The present invention has been found. Sand
A depth of 0.6 to 1.5 μm and a half width of 5 to 30 μm.
Il pits are 40 pieces / mm on the board surface²That
I do. Here, "depth" is as shown in FIG.
The distance from the edge of the oil pit (the highest point) to the bottom
To taste. Also, the diameter of the opening of the oil pit is
It directly contributes to the gloss, but which part is measured as the opening
It is difficult to determine whether
The width of the oil pit at position 2 is defined as the half width,
Value defines the size and shape of the oil pit.
Was. The cross-sectional shape of the oil pit at the half-width position is circular.
If not, find the area of the cross section and
Let the diameter of the circle be the half width. 0.6-1.5 μm depth, half
The value width of 5 to 30 μm is 1/10 of the roughness of the plate surface.
This size is equivalent to ~ 1/3, and this size has a large effect on gloss reduction.
Resonates. This oil pit is 40 pieces / mm on the plate surface²To
Above this, diffuse reflection of incident light becomes remarkable, and gloss
It decreases significantly. However, 40 pieces / mm²Don't be
If used as a can lid, it is possible to obtain sufficient gloss
it can. In addition, well-shaped oil deeper and narrower than this rule
Pits are unlikely to occur, and even if they do, the caliber is small
The effect on gloss is small. Rolling roll roughness
Of the rolling oil between the valley of the
Deep from the oil pit generation mechanism
Big things do not occur. On the other hand, those with shallow depth
It is buried in the roughness of the surface, and the effect on gloss is almost
Almost no. From these facts, other depth and half width
There is no provision for oil pits. A depth of 0.6 to 1.5 μm and a half width of 5 to 30
40 μm oil pits / mm²Below
As a way to control Use low viscosity rolling oil Reduce rolling reduction Use rolling rolls with small roughness It can be realized by a combination of such methods. alloy
Determined by the composition and the manufacturing process up to cold rolling
But not for example casting 5052 alloy, hot rolling,
After primary cold rolling and intermediate annealing, the center line of the roll surface
Use a rolling roll with an average roughness Ra of 0.04 to 0.6 μm
And perform final cold rolling at a reduction of 20 to 50%.
Can be achieved. [0008] EXAMPLE Cast 5052 alloy, hot rolling, primary cold pressure
After rolling and intermediate annealing, the viscosity and rolling reduction of
After various changes, final cold rolling was performed to obtain a rolled plate. Cold pressure
Rolling was performed using a roll with a roll roughness Ra of 0.42 μm.
The rolling speed was 30 m / s. As cold rolling oil, 40
Kinematic viscosity at ℃ 1.1mm²/ S and 5.6mm ²/
The ratio was adjusted to adjust the viscosity. This cold
Depth 0.6-1.5 μm, half width at the time of cold rolled sheet
The number of oil pits having a size of 5 to 30 μm (pieces / mm
²) Was measured. Light is incident on this plate at an incident angle of 45 °.
Of the direct reflected light reflected at a reflection angle of 45 °
The intensity was measured and the reflectance was determined. [0009] [Table 1] As shown in Table 1, in each of the examples of the present invention,
While the reflectivity shows high gloss exceeding 20%,
In Comparative Examples which do not meet the requirements of the invention, the gloss is low, and
It gives a cloudy impression when used as a can lid
U. [0011] As described above, according to the present invention,
Aluminum plate with sufficient glossiness as it is cold rolled plate
Is obtained stably. This is clear painted as a can lid material
If you use it, the coating film looks hazy and the color tone is dull
Problems such as poor appearance quality such as
It is.

[Brief description of the drawings] FIG. 1 is an explanatory diagram showing a shape of a plate surface. [Explanation of symbols] 1 ‥‥‥ Oil pit 2 ‥‥‥ depth 3 ‥‥‥ half width 4 ‥‥‥ Aluminum plate surface 5 ‥‥‥ aluminum plate

Claims (1)

Claims: 1. A depth of 0.6 to 1.5 μm and a half width of 5 to 3.
An aluminum plate for a can lid excellent in glossiness, characterized in that oil pits of 0 μm are 40 / mm ² or less on the plate surface.