JP2014152398A - Aluminum alloy product coated with fluororesin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy product coated with a fluororesin which has good non-stickiness and scratching resistance, a beautiful product surface and an extended service life of the product.SOLUTION: An aluminum alloy product coated with a fluororesin comprises: an aluminum alloy having crimps in the surface; a hard anode oxidation film covering the surface of the aluminum alloy; and a fluororesin coating layer. The fluororesin coating layer comprises: a primer layer on the surface of the hard anode oxidation film; a middle layer; and a top layer. The aluminum alloy has a Vickers hardness HV of 20-30. The crimps are irregular convexoconcave parts with the top of the convex parts being arc-like, and their roughness is such as to give a ten-point height Rz of 80-150 μm and arithmetic average roughness Ra of 20-40 μm. The primer layer is formed by coating at a surface temperature of the aluminum alloy of 30-50°C.

Description

  The present invention relates to a manufacturing area of aluminum alloy products, and particularly to an aluminum alloy product coated with a fluororesin.

  Conventionally, aluminum alloys have been widely applied to various aspects of daily life and industrial production. Due to the excellent non-adhesiveness and chemical stability of fluororesin, the surface coating of aluminum alloy products for cooking utensils, such as non-adhesive pans, is usually coated with fluororesin. The process of aluminum alloy products generally includes a process of first performing sand blasting on the surface of the aluminum alloy, and forming a small hole by sand blasting and then applying fluororesin.

  However, such a processing method has a problem that bubbles are easily formed, which causes the paint to fall off, and the paint surface cannot withstand scratching by a sharp object. Such problems are often a direct cause of shortening the service life of the product.

  U.S. Pat. No. 4,768,427 discloses an aluminum alloy product having an uneven surface, and the product has a hard anodized film formed on the surface of the aluminum alloy and a fluororesin coating on the hard anodized film. (See Patent Document 1).

  Japanese Patent No. 2,763,833 discloses a method for realizing scratch resistance and prevention of paint drop-off by using the wrinkles generated in the aluminum alloy itself. First, wrinkles are generated using a mold on the surface of the aluminum alloy. Then, sand blasting is performed, then hard inorganic coating such as ceramic is performed, and finally fluororesin coating is performed (see Patent Document 2).

US Pat. No. 4,768,427 Japanese Patent No. 2763833

  The unevenness disclosed in Patent Document 1 is a linear regular circumferential shape, and the unevenness having such a shape has a poor ability to disperse pressure against a sharp object. For example, metal utensils such as kitchen knives and frying tools are used. Then, surface scratches and paint removal occur very easily.

  The technology disclosed in Patent Document 2 reduces the contact surface of the metal tool with the aluminum alloy product by using the texture on the surface of the aluminum alloy, and improves the abrasion resistance performance of the product. In addition, a hard film such as a hard anodized film or hard inorganic coating is effective in increasing the surface hardness of the product, improves the scratch resistance of the product, and helps prevent deformation of the wrinkles. Certainly, the fluororesin paint on the convex portion of the product surface can prevent the fluororesin paint on the concave portion from being worn, and the non-adhesive effect on the product surface can be maintained as much as possible. However, this technology does not consider protecting the paint on the convex part, so the paint on the convex part is also easily worn away, and it is inevitable that the paint drops off easily within a short time. The non-adhesive effect is deteriorated and the product life is shortened, and at the same time, the aesthetics of the product surface are affected.

  Therefore, the object of the present invention is to overcome the current shortage of production of aluminum alloy products, improve the non-adhesiveness and scratch resistance of aluminum alloy products, and at the same time consider the aesthetics of the product surface and improve the product life. It is to extend.

  In order to achieve the above object, a fluororesin-coated aluminum alloy product according to the present invention comprises an aluminum alloy having a grain on its surface, a hard anodized film covering the surface of the aluminum alloy, and a fluororesin coating layer. The fluororesin coating layer includes a primer layer, a middle layer, and a top layer on the surface of the hard anodized film. The aluminum alloy has a Vickers hardness of HV = 20 to 30, and the wrinkles have an arc shape at the top of the convex portion. The roughness is 10 points average height Rz = 80 μm to 150 μm, arithmetic average roughness Ra = 20 μm to 40 μm, and the primer layer is an aluminum alloy with a surface temperature of 30 ° C. to 50 ° C. It is characterized in that it was formed at a temperature of ℃.

  The aluminum alloy product coated with the fluororesin of the present invention preferably has an aluminum alloy having a Vickers hardness of HV = 22 to 28, and a grain roughness having a ten-point average height of Rz = 100 μm to 130 μm and an arithmetic average roughness. Ra = 20 μm to 30 μm.

  The fluororesin-coated aluminum alloy product of the present invention preferably has a hard anodized film thickness of 25 μm to 45 μm and a Vickers hardness of HV = 300 to 370, more preferably a hard anodized film thickness of 35 μm to 45 μm. And the Vickers hardness is HV = 320 to 350.

  In the fluororesin-coated aluminum alloy product of the present invention, the thickness of the fluororesin coating layer is preferably 30 μm to 50 μm, and more preferably the thickness of the fluororesin coating layer is 35 μm to 45 μm.

  The aluminum alloy product coated with the fluororesin of the present invention preferably has a primer layer thickness of 10 μm to 15 μm.

  In the aluminum alloy product coated with the fluororesin of the present invention, the primer layer is preferably formed by coating when the surface temperature of the aluminum alloy is 35 ° C to 45 ° C.

  The aluminum alloy product coated with the fluororesin of the present invention preferably has a microporous rough surface having a depth of 2 μm to 8 μm by sandblasting on the surface of the aluminum alloy.

  An aluminum alloy product coated with a fluororesin of the present invention comprises an aluminum alloy having a grain on the surface, a hard anodized film covering the surface of the aluminum alloy, and a fluororesin coating layer. The Vickers hardness of the aluminum alloy, the shape of the grain, Good non-adhesiveness and scratch resistance can be obtained at the same time by specific numerical settings such as distribution and roughness, hard anodized film thickness and Vickers hardness, fluororesin coating layer thickness and coating temperature, etc. Considering the beauty of the product, it will extend the service life of the product.

  The above objects and advantages of the present invention and other objects and advantages will be more clearly understood through the following description of embodiments. However, the embodiments described below are merely examples, and the present invention is not limited to these.

It is a figure which shows the embossing of the aluminum alloy product by which the fluororesin coating of this invention was carried out.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A fluororesin-coated aluminum alloy product provided by the present invention comprises an aluminum alloy having a grain on its surface, a hard anodized film layer covering the aluminum alloy surface, and a fluororesin coating layer. The specific manufacturing process is as follows.

  (1) On the surface of a relatively soft aluminum alloy, irregular wrinkles having a vertices of convex portions with surface roughness within a reference range are formed.

  The present invention employs an aluminum alloy having a relatively soft hardness, and its Vickers hardness is HV = 20-30, preferably 22-28, which is affected by the convex portions of the product surface wrinkles in the process of use. It allows reduction deformation or lateral movement due to pressure within a certain range, so that it is not worn out immediately.

  The surface of the aluminum alloy employed in the present invention has irregular wrinkles, and the irregularities are shown in FIG. 1, and the irregularities 1 are arc-shaped (smooth), with smooth vertices and roundness. Therefore, compared to a triangle-shaped grain with a sharp apex, the area received is larger, the pressure resistance is stronger, and therefore the abrasion resistance is better.

  Compared to regular circumferential irregularities, irregular irregularities are sharp, but the pressure dispersibility is better, and it is possible to effectively prevent scratches caused by sharp metals such as knives and frying.

  According to research, the roughness of the wrinkles has a relatively large effect on the non-stickiness and scratch resistance of the product. For example, if the roughness is small, the surface of the product is close to a flat surface, and the convex part cannot protect the concave part. This is disadvantageous to the scratch resistance of the product, and conversely, for example, if the roughness is large, fluid or foreign substances easily stick to the relatively deep recess on the product surface in the process of use.

  The inventor of the present invention, after long-term testing and research on the scratch resistance and non-stickiness of the surface of aluminum alloy products in the situation of using metal tools, When Rz = 80 μm to 150 μm and arithmetic average roughness Ra = 20 μm to 40 μm, preferably the ten-point average height is Rz = 100 μm to 130 μm and arithmetic average roughness Ra = 20 μm to 30 μm, the product is excellent It has been found to have non-stickiness and scratch resistance.

  The texture on the surface of the aluminum alloy is usually formed by a die pressing method, but can also be formed by other casting methods or casting. Concavities and convexities formed by the press method are always formed in the vertical direction and have no lateral projections. Such protrusions having the same direction prevent the air under the coating formed on the surface of the subsequent aluminum alloy, and the coating is not damaged by the expansion of the air under the coating in the heated state. The texture on the mold surface is generally generated by an acid solution corrosion process.

  It should be noted that the distance and pressure of the pressing process should be adjusted moderately during mold pressing, so that the concave part of the mold surface does not completely contact the aluminum body, and the apex of the convex part of the formed aluminum alloy is an arc shape. In other words, it is not allowed to have the same shape as the convex portion on the mold surface.

  (2) Sand blasting is performed on an aluminum alloy having a grain on the surface.

  The purpose of sandblasting is to form a 2 to 8 μm microporous rough surface on the surface of the aluminum alloy. The sand used in the sand blasting is generally aluminum oxide or granules mainly composed of aluminum oxide.

  Before sandblasting, the surface of the aluminum alloy is first degreased and washed with an overheated detergent to wash off the oil and fat on the surface of the aluminum alloy, and the quality of the subsequent sandblasting is improved. After the alkaline degreasing cleaning, it is not always necessary, but preferably, the aluminum alloy surface may be subjected to acidic cleaning to further improve the cleaning effect.

  After sandblasting, alkali degreasing cleaning is performed again, and dirt and dust that have entered the surface recesses are cleaned and removed, which is useful for the subsequent generation of a hard anodized film. Similarly, after the alkaline degreasing cleaning, the cleaning effect may be enhanced by performing acidic cleaning again.

  (3) A hard anodized film is formed on the aluminum alloy surface after sandblasting.

  According to research, a hard anodized film with a thickness of 25 μm to 45 μm and a Vickers hardness HV = 300 to 370, preferably a hard anodized film with a thickness of 35 μm to 45 μm and a Vickers hardness HV = 320 to 350, on the aluminum alloy surface after sandblast By forming the film, the surface hardness of the aluminum alloy product can be greatly increased, and excessive deformation due to the pressure on the surface of the aluminum product can be prevented. At the same time, the hard anodic oxide film makes the fluororesin paint on the surface of the product better adherence and is effective in preventing the fluororesin paint from falling off.

  A hard anodized film can be formed by anodizing, for example, in a mixed solution of sulfuric acid or sulfuric acid and nitric acid, a hard anodized film can be formed by energizing aluminum alloy products for a certain period of time as an anode. I can do it.

  The sealing treatment may be performed immediately after the formation of the hard anodic oxide film.

  (4) A fluororesin coating layer is formed on the surface of the hard anodized film.

  Next, a primer layer, a middle layer and a top layer are coated on the surface of the hard anodized film, and this structure is used as a fluororesin coating layer of an aluminum alloy product.

  First, the product is preheated, and primer coating is performed when the surface temperature of the aluminum alloy is 30 ° C. to 50 ° C., preferably 35 ° C. to 45 ° C. after natural cooling. adjust.

  If the surface temperature is low when painting the primer layer, the primer layer cannot be fixed to the convex surface of the embossed surface, which causes insufficient strength of the convex coating layer, and the convex coating layer easily falls off. To do. On the contrary, when the surface temperature is high when the primer layer is applied, the applied paint easily evaporates or changes in quality, causing a loss of effectiveness of the primer layer.

  After the primer layer is applied, the primer layer is dried, and then the middle layer and the top layer are applied. It should be noted that the total film thickness of all the fluororesin coating layers, that is, the primer layer, the middle layer and the top layer is kept in the range of 30 μm to 50 μm, preferably 35 μm to 45 μm, and the excellent non-adhesiveness and chemical properties of the product It is to keep the stability.

  The present invention adjusts the specific settings such as the Vickers hardness, the shape, distribution and roughness of the aluminum alloy, the thickness and Vickers hardness of the hard anodized film, and the thickness and coating temperature of the fluororesin coating layer, Get product performance. As a result of the test, all of the specific examples shown in Table 1 below achieved relatively good non-adhesiveness and scratch resistance, and at the same time, the appearance of the product was beautiful and the product life could be extended.

  The present invention is suitably used for all aluminum alloy products coated with fluororesin.

Claims (10)

An aluminum alloy product coated with fluororesin,
An aluminum alloy having a grain on the surface, a hard anodic oxide film covering the surface of the aluminum alloy, and a fluororesin coating layer. The fluororesin coating layer includes a primer layer, a middle layer, and a top layer on the surface of the hard oxide film. Including
The aluminum alloy has a Vickers hardness of HV = 20-30,
The wrinkles are irregular irregularities in which the tops of the convex portions are arc-shaped, and the roughness is a ten-point average height of Rz = 80 μm to 150 μm and an arithmetic average roughness of Ra = 20 μm to 40 μm,
The primer layer is formed by coating when the surface temperature of the aluminum alloy is 30 ° C. to 50 ° C .;
An aluminum alloy product coated with fluororesin. The aluminum alloy has a Vickers hardness of HV = 22 to 28,
The aluminum alloy product coated with fluororesin according to claim 1. The grain has a ten-point average height of Rz = 100 μm to 130 μm and an arithmetic average roughness of Ra = 20 μm to 30 μm.
The aluminum alloy product coated with fluororesin according to claim 1 or 2. The hard anodized film has a thickness of 25 μm to 45 μm and a Vickers hardness of HV = 300 to 370;
The aluminum alloy product coated with fluororesin according to claim 3. The hard anodized film has a thickness of 35 μm to 45 μm and a Vickers hardness of HV = 320 to 350;
The aluminum alloy product coated with a fluororesin according to claim 4. The fluororesin coating layer has a thickness of 30 μm to 50 μm,
The aluminum alloy product coated with fluororesin according to claim 3. The fluororesin coating layer has a thickness of 35 μm to 45 μm;
The aluminum alloy product coated with fluororesin according to claim 6. The primer layer has a thickness of 10 μm to 15 μm;
The aluminum alloy product coated with fluororesin according to claim 3. The primer layer is formed by coating when the surface temperature of the aluminum alloy is 35 ° C to 45 ° C;
The aluminum alloy product coated with fluororesin according to claim 3. Having a microporous rough surface with a depth of 2 to 8 μm by sandblasting on the surface of the aluminum alloy;
The aluminum alloy product coated with fluororesin according to claim 3.

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