White aluminum foil

Abstract

To provide a white aluminum foil which improves a degree of whiteness of a white coat layer.SOLUTION: A white aluminum foil 10 has a colorless intermediate coat layer 13 containing a resin and no coloring pigment interposed between a body 11 composed of an aluminum foil and a white coat layer 12, and has a lightness L value pf 82 or more when a surface where the white coat layer 12 of the body 11 is stacked is measured according to 5.3.1 c) geometric condition c and 5.3.3 b) method b of JIS Z 8722:2009 color measuring method-reflectance and transmission object color. The white aluminum foil 10 dispenses with processes of increasing the thickness of the white coat layer 12, increasing the content of a white pigment, and repeating coating a plurality of times, the degree of whiteness of the white coat layer 12 is higher than that through the processes, and peeling is suppressed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a white aluminum foil with high whiteness and a white aluminum foil molded body using the same. [Background technology]

[0002] Conventionally, in order to improve the design of an aluminum foil molding using aluminum foil, a colored ink such as white ink is sometimes printed and applied in advance to the surface of the aluminum foil that serves as the main body (e.g., paragraph 0048 of Patent Document 1), thereby forming a white coating layer. In the printing and coating of such a white coating layer, since the underlying aluminum foil has a silver or gray color tone, the white coating layer turns grayish white, and there is a problem that it does not exhibit the desired white color.

[0003] In order to prevent the white coating layer from becoming grayish white, attempts have been made to increase the thickness of the white coating layer that is printed and applied, to increase the content of the white pigment in the white coating layer, or to repeatedly apply the white coating layer multiple times, which can achieve a certain level of whiteness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-44567 Summary of the Invention [Problem to be solved by the invention]

[0005] However, increasing the thickness of the white coating layer to be printed and applied, increasing the amount of white pigment contained in the white coating layer, or repeatedly applying the white coating layer multiple times increases the amount of raw material used, resulting in higher costs, and also increases the number of coating steps, resulting in increased costs, labor, and time.

[0006] Furthermore, although increasing the content of the white pigment in the white coating layer improves the whiteness to a certain extent, the large amount of white pigment contained therein leads to a decrease in the adhesion of the white coating layer, which may cause the white coating layer to peel off easily or crack easily. In particular, when producing an aluminum foil molded product by molding aluminum foil into a desired shape by press molding or the like, the white coating layer does not follow the shape changes of the aluminum foil during molding, and the white coating layer is prone to peeling and cracking.

[0007] Furthermore, even if the thickness of the white coating layer or the content of the white pigment is increased in this way, it is still not possible to obtain a desired white aluminum foil with high whiteness.

[0008] Therefore, the problem to be solved by the present invention is to provide a white aluminum foil that does not require increasing the thickness of the white coating layer, increasing the content of the white pigment, or repeating coating multiple times, and has a higher degree of whiteness than when these steps are performed, and in which peeling of the white coating layer is also suppressed, and a white aluminum foil molded body molded from such a white aluminum foil. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive studies and have found that by providing a colorless intermediate coating layer between the main body made of aluminum foil and the white coating layer and setting the lightness L value of the surface on which the white coating layer is laminated within a predetermined range, it has been found that a white aluminum foil with a higher whiteness than conventional white aluminum foil can be obtained.

[0010] That is, in order to solve the above-mentioned problems, the white aluminum foil according to the present invention comprises a main body made of aluminum foil, a white coating layer containing a white pigment and a resin laminated on at least one side of the main body, and a colorless intermediate coating layer interposed between the main body and the white coating layer, containing a resin but not a colored pigment. The surface of the main body on which the white coating layer is laminated has a lightness L value of 82 or more, measured in accordance with 5.3.1 c) geometric condition c and 5.3.3 b) method b of JIS Z 8722:2009, Methods for measuring color - Reflected and transmitted object color.

[0011] By configuring in this manner, it is possible to obtain a white aluminum foil with a higher whiteness (whiteness) than conventional aluminum foils, without the need to increase the thickness of the white coating layer, increase the content of the white pigment, or repeat coating multiple times. Furthermore, since the intermediate coating layer is strongly adhered to the aluminum foil substrate and the white coating layer, when the white aluminum foil is formed, the intermediate coating layer and the white coating layer follow the deformation of the main body, thereby suppressing peeling and cracking of the white coating layer.

[0012] In the white aluminum foil according to the present invention, it is preferable to adopt a configuration in which the resin in the intermediate coating layer contains one or more resins selected from the group consisting of acrylic ester resin, modified epoxy resin, vinyl chloride resin, vinyl acetate resin, and polyester polyol resin.

[0013] By including such a resin in the intermediate coating layer, the adhesion between the intermediate coating layer and the white coating layer is further improved, and when the white aluminum foil is formed, the intermediate coating layer and the white coating layer are more likely to follow the deformation of the aluminum foil base material. Therefore, peeling and cracking of the white coating layer can be further suppressed.

[0014] In the white aluminum foil according to the present invention, it is preferable that the white pigment in the white coating layer is a titanium dioxide pigment, and the weight percentage of the titanium dioxide pigment as a solid content in the white coating layer is 30% by weight or more and 80% by weight or less.

[0015] By configuring in this manner, it is possible to further suppress peeling and cracking of the white coating layer from the aluminum foil base material while maintaining a higher whiteness of the white aluminum foil.

[0016] In the white aluminum foil according to the present invention, when the average thickness of the intermediate coating layer is 0.5 μm or more and 1.5 μm or less and the average thickness of the white coating layer is 0.5 μm or more and 1.5 μm or less, the whiteness of the white aluminum foil and the suppression of peeling and cracking of the white coating layer can be achieved at a high level.

[0017] In the white aluminum foil according to the present invention, if a configuration is adopted in which the lightness L value is greater than the lightness L value of the surface on which the white coating layer is formed of a two-layer white aluminum foil in which a white coating layer is formed twice on an aluminum foil base material without forming a colorless intermediate coating layer, the white aluminum foil will have a higher whiteness (whiteness) than conventional white aluminum foils.

[0018] In the white aluminum foil according to the present invention, when the average thickness of the main body is 20 μm or more and 200 μm or less, it becomes easy to form and process into a foil molded body.

[0019] Moreover, by forming the white aluminum foil having the above-described configuration into a white aluminum foil molded body, it is possible to obtain a white aluminum foil molded body having high whiteness and excellent designability. An example of such a white aluminum foil molded product is a cooking oil protection panel. [Effects of the Invention]

[0020] By configuring the present invention as described above, it is not necessary to increase the thickness of the white coating layer, increase the content of the white pigment, or repeat coating multiple times, and the white coating layer has a higher degree of whiteness than when these steps are performed. A white aluminum foil and a white aluminum foil molded body in which peeling of the white coating layer is also suppressed can be obtained. [Brief explanation of the drawings]

[0021] [Figure 1] Cross-sectional view of a white aluminum foil according to an embodiment DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the white aluminum foil 10 of the embodiment includes a main body 11 made of aluminum foil, a white coating layer 12 laminated on at least one side of the main body 11, and an intermediate coating layer 13 interposed between the main body 11 and the white coating layer 12. Here, the white coating layer 12 is a white coating layer containing at least a white pigment and a resin, and the intermediate coating layer 13 is a colorless coating layer containing at least a resin but not a color pigment.

[0023] Here, the refractive index of the white coating layer 12 is 1.8 or more and 2.7 or less, and the difference between the refractive index of the white coating layer 12 and the refractive index of the intermediate coating layer 13 (refractive index of the white coating layer - refractive index of the intermediate coating layer) is adjusted to 0.3 or more and 1.2 or less. The difference between the refractive index of the white coating layer 12 and the refractive index of the intermediate coating layer 13 is more preferably 0.6 or more and 1.0 or less, and even more preferably 0.7 or more and 0.9 or less. By adopting such a configuration, the white aluminum foil 10 has a higher whiteness (whiteness) than conventional ones. The white coating layer 12 and the intermediate coating layer 13 do not need to be formed on the entire surface of the aluminum foil body 11, but may be formed only on a portion of the surface. Also, a different colored coating layer may be formed on the white coating layer 12. In this case, the color of the colored coating layer will be more beautiful.

[0024] The mechanism by which a white aluminum foil with a higher whiteness (whiteness) than conventional aluminum foil is obtained by setting the refractive index of the white coating layer 12 to 1.8 or more and 2.7 or less and setting the difference between the refractive index of the white coating layer 12 and the refractive index of the intermediate coating layer 13 (refractive index of the white coating layer - refractive index of the intermediate coating layer) to 0.3 or more and 1.2 or less is not necessarily clear. However, it is believed that the multi-layer structure with a refractive index difference has achieved a higher whiteness (whiteness) than conventional structures due to a combination of factors such as changes in the degree of light scattering and the occurrence of diffraction and interference phenomena, compared to single-layer or multi-layer structures with no refractive index difference.

[0025] The aluminum foil forming the main body 11 can be any known aluminum foil, and is not particularly limited, but for example, an 8000 series (8011, etc.) aluminum foil can be used. The thickness is preferably 20 μm or more and 200 μm or less. If the thickness is within this range, molding and processing are facilitated when a molded product is produced using the white aluminum foil 10. In addition, a desired strength can be obtained.

[0026] The intermediate coating layer 13 is a colorless layer containing resin but not coloring pigment, and this allows a white aluminum foil 10 to be obtained that has a higher degree of whiteness (whiteness) than conventional white aluminum foil in which a white coating layer 12 is directly laminated on a main body 11 made of aluminum foil. In addition, the presence of the intermediate coating layer 13 improves adhesion between the main body 11 and the white coating layer 12, and when the white aluminum foil 10 is molded, the white coating layer 12 can more easily follow the deformation of the main body 11 made of aluminum foil, thereby suppressing peeling and cracking.

[0027] The intermediate coating layer 13 is preferably configured to contain one or more resins selected from the group consisting of acrylic ester resin, modified epoxy resin, vinyl chloride resin, vinyl acetate resin, and polyester polyol resin. By including these resins, the adhesion of the intermediate coating layer 13 to the main body 11 and the white coating layer 12 is further improved, and when the white aluminum foil 10 is formed, the white coating layer 12 follows the deformation of the main body 11, thereby further suppressing peeling and cracking. Examples of acrylic ester resins include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate. Examples of modified epoxy resins include bisphenol A polyol, bisphenol F polyol, and bisphenol S polyol. Examples of polyester polyol resins include polyester polyols obtained by dehydration condensation, which are composed of adipic acid and phthalic acid as carboxylic acid units and ethylene glycol, 1,4-butanediol, and 1,6-hexanediol as alcohol units.

[0028] The refractive index of the intermediate coating layer 13 is preferably 1.4 or more and 1.7 or less, and more preferably 1.5 or more and 1.6 or less. By having the refractive index within this range, the difference in refractive index with the white coating layer 12 can be increased, which tends to lead to a higher degree of whiteness (whiteness) than before.

[0029] The white coating layer 12 contains a white pigment and a resin. The white pigment is not particularly limited, but examples thereof include titanium dioxide and zinc oxide. Titanium dioxide pigment is particularly preferred in terms of versatility, hiding power, and whiteness. Here, the refractive index of the white pigment itself is preferably 2.0 or more and 3.0 or less. Titanium dioxide pigment is suitable because it has a high refractive index of 2.72. By having the refractive index of the pigment within this range, the refractive index of the white coating layer 12 can be increased and the difference in refractive index with the intermediate coating layer 13 can be increased, which tends to lead to a higher degree of whiteness (whiteness) than before.

[0030] The content by weight of titanium dioxide pigment as a solid content in the white coating layer 12 is preferably 30% by weight or more and 80% by weight or less, and more preferably 55% by weight or more and 65% by weight or less. Within this range, peeling and cracking of the white coating layer from the aluminum foil substrate can be further suppressed while maintaining a higher whiteness of the white aluminum foil. The average particle size of the titanium dioxide pigment is preferably 200 nm or more and 1 μm or less, which is preferable in terms of high hiding power.

[0031] The resin contained in the white coating layer 12 is not particularly limited, but, like the intermediate coating layer 13, it is preferable that the white coating layer 12 is composed of one or more resins selected from the group consisting of acrylic ester resin, modified epoxy resin, vinyl chloride resin, vinyl acetate resin, and polyester polyol resin. The inclusion of these resins reliably prevents the white pigment from peeling off or falling off from the white coating layer 12. That is, it is possible to ensure reliable adhesion of the white pigment in the white coating layer 12. At the same time, the adhesion between the intermediate coating layer 13 and the white coating layer 12 is also improved, so that when the white aluminum foil 10 is molded, the white coating layer 12 follows the deformation of the main body 11, thereby further preventing peeling and cracking. Examples of acrylic ester resins include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate. Examples of modified epoxy resins include bisphenol A polyol, bisphenol F polyol, and bisphenol S polyol. Examples of polyester polyol resins include polyester polyols obtained by dehydration condensation, which are composed of adipic acid and phthalic acid as carboxylic acid units and ethylene glycol, 1,4-butanediol, and 1,6-hexanediol as alcohol units.

[0032] The refractive index of the white coating layer is 1.8 to 2.7, preferably 2.0 to 2.5, and more preferably 2.2 to 2.4. This range allows for a larger difference in refractive index with the intermediate coating layer, resulting in a higher whiteness (whiteness) than conventional coatings. Furthermore, this range is preferable in terms of maintaining the adhesion of the white pigment in the white coating layer.

[0033] The average thickness of the intermediate coating layer 13 is preferably 0.5 μm or more and 1.5 μm or less, and the average thickness of the white coating layer 12 is preferably 0.5 μm or more and 1.5 μm or less. Within this range, it is possible to achieve both high levels of whiteness of the white aluminum foil 10 and high levels of prevention of peeling and cracking of the white coating layer 12 from the main body 11.

[0034] The white aluminum foil 10 of the embodiment can be subjected to press molding or the like to form the white aluminum foil molded body of the embodiment. An example of such a panel is a cooking oil protection panel that is used to surround three sides of a kitchen range. The aluminum foil molded article can also be used in the kitchen, such as an exhaust vent cover, a ventilation fan cover, an aluminum foil framed range hood filter having an anti-oil stain filter in the frame attached to the range hood, or a gap cover for a range. By configuring the white aluminum foil 10 as described above, a white aluminum foil molding having high whiteness and excellent design properties can be obtained. [Example]

[0035] The present invention will be further clarified below by giving examples and comparative examples. First, the following aluminum foils of Examples 1 to 6 and Comparative Examples 1 to 4 were prepared.

[0036] Example 1 Using a bar coater #6 (manufactured by RK Print Coat Instruments), a 50 μm aluminum foil body was coated with a coating solution that had been mixed and stirred after adjusting the weight ratio of the solid content of butyl acrylate diluted with methyl ethyl ketone solvent to 57.1 wt %, the weight ratio of the solid content of bisphenol A polyol to 28.6 wt %, and the weight ratio of the solid content of isocyanate to 14.3 wt %, resulting in a coating weight of 2.5 to 3.0 g / m after drying. 2 The intermediate coating layer was formed so as to have the following properties. This colorless resin layer (intermediate coating layer) was dried at room temperature of 25° C. for 24 hours. Next, using a bar coater #6 (manufactured by RK Printcoat Instruments) of the same model number, a white ink (coating liquid containing a white pigment) diluted with methyl ethyl ketone solvent containing 61.9 wt% titanium dioxide (TiO2) as a solid content, 30.9 wt% bisphenol A polyol as a resin as a solid content, and adjusted so that the solid content weight ratio of hexamethylene diisocyanate was 7.2 wt% was mixed and stirred. The white ink was then applied to the resin layer in a coating amount of 1.0 to 1.5 g / m2 after drying. 2 The coating was thoroughly dried, and a white coating layer was laminated on the intermediate coating layer on the aluminum foil substrate. After drying for 24 hours, a white aluminum foil was obtained. The titanium dioxide used as the white pigment here was titanium dioxide produced by the chlorine method, had an average particle size of 250 nm (200 to 300 nm), and was of the rutile type.

[0037] Example 2 A coating liquid containing only butyl acrylate in a methyl ethyl ketone diluted solvent was applied to the same aluminum foil substrate as used in Example 1 using a bar coater and dried to form an intermediate coating layer. Thereafter, the coating liquid containing the white pigment was applied in the same manner as in Example 1 to obtain a white aluminum foil.

[0038] Example 3 As in Example 1, a coating liquid containing only bisphenol A polyol in a solvent of methyl ethyl ketone:toluene=1:1 was applied to an aluminum foil substrate using a bar coater and dried to form an intermediate coating layer. Thereafter, the coating liquid containing the white pigment was applied in the same manner as in Example 1 to obtain a white aluminum foil.

[0039] Example 4 As in Example 1, a coating liquid containing a resin composed of vinyl chloride:vinyl acetate:dicarboxylic acid in a polymerization ratio of 84:15:1 in a dilution solvent of methyl ethyl ketone:toluene = 1:1 by weight was applied to an aluminum foil substrate using a bar coater and dried to form an intermediate coating layer. Thereafter, the coating liquid containing the white pigment was applied in the same manner as in Example 1 to obtain a white aluminum foil.

[0040] Example 5 As in Example 1, a coating liquid containing saturated polyester polyol in a dilution solvent of ethyl acetate:toluene=1:1 was applied onto an aluminum foil substrate and dried to form an intermediate coating layer. Thereafter, the coating liquid containing the white pigment was applied in the same manner as in Example 1 to obtain a white aluminum foil.

[0041] Example 6 A coating solution was applied to a main body made of 50 μm aluminum foil using a gravure plate. The coating solution was a precursor solution containing butyl acrylate resin and bisphenol A polyol in a weight ratio of 2:1, diluted in methyl ethyl ketone, to which hexamethylene diisocyanate had been added, and the solid weight ratio of isocyanate in the coating solution was adjusted to 14.3 wt% (i.e., the remaining solids were 85.7 wt% and the butyl acrylate resin and bisphenol A polyol were contained in a weight ratio of 2:1). The coating solution was then passed through a drying zone and dried to form an intermediate coating layer. Onto the dried intermediate coating layer, a gravure plate was used to apply a white ink mixture (diluting solvents mainly methyl ethyl ketone and toluene) containing 51.5 wt% titanium dioxide (TiO2) as solid content, 41.2 wt% bisphenol A polyol, and adjusted so that the solid weight ratio of hexamethylene diisocyanate was 7.2 wt%, forming a white coating layer and obtaining a white aluminum foil.

[0042] (Comparative Example 1) As in Example 1, the same white ink (coating liquid containing a white pigment) as used in Example 1 was directly applied to a 50 μm aluminum foil substrate and thoroughly dried to obtain a white aluminum foil. This corresponds to a conventional white aluminum foil without an intermediate coating layer.

[0043] (Comparative Example 2) A white ink (a coating liquid containing a white pigment) was applied on top of the white aluminum foil of Comparative Example 1 in the same manner as in Comparative Example 1 to form another white coating layer, thereby obtaining a white aluminum foil with two white coating layers. This corresponds to a conventional white aluminum foil having no intermediate coating layer and a thick white coating layer.

[0044] (Comparative Example 3) As in Example 1, a 50 μm aluminum foil substrate contained titanium dioxide (TiO2), but contained 1.3 times the weight of titanium dioxide pigment (80.47 wt%), with the remaining solid content being 15.84 wt% butyl acrylate bisphenol A polyol and 3.69 wt% hexamethylene diisocyanate. A white ink (coating liquid containing a white pigment) in which the dilution solvent was methyl ethyl ketone was directly coated onto the aluminum foil substrate and thoroughly dried to obtain a white aluminum foil. This corresponds to a conventional white aluminum foil that does not have an intermediate coating layer and contains a large amount of white pigment in the white coating layer.

[0045] Comparative Example 4 In the same manner as in Example 1, a colorless resin layer (intermediate coating layer) similar to that in Example 1 was formed on an aluminum foil substrate using a bar coater. Then, for the white ink, the titanium dioxide (TiO2) used in Example 1 was replaced with zinc oxide and the content was reduced to obtain a white ink (coating liquid containing a white pigment) containing zinc oxide pigment (28.0% by weight) and the remaining solid content consisting of 48.0% by weight of butyl acrylate bisphenol A polyol and 24.0% by weight of hexamethylene diisocyanate, and using methyl ethyl ketone as a dilution solvent. The white ink was then directly coated onto the aluminum foil substrate and thoroughly dried to obtain a white aluminum foil.

[0046] The lightness L values ​​of the aluminum foils of Examples 1 to 6 and Comparative Examples 1 to 4 were measured using a spectrophotometer (Konica Minolta, Inc., Model No. Spectrophotometer CM-5) under conditions of a 10° field of view and a D65 light source, in accordance with 5.3.1 c) Geometrical Condition c and 5.3.3 b) Method b of JIS Z 8722:2009, Measurement of Color - Reflected and Transmitted Object Color. Three randomly selected points on the coated surface were measured for L value, and the average values ​​are shown in the table below. Here, the L value indicates brightness, and the larger the L value, the greater the whiteness and the whiter the color is perceived to be. An L value of 82 or more was evaluated as ◯, and an L value of less than 82 was evaluated as ×. The results are shown in Table 1 below. From Table 1, it was confirmed that the whiteness was good in all of the examples, whereas the whiteness was insufficient in the comparative examples, except for comparative example 3.

[0047] [Table 1]

[0048] Furthermore, test pieces of 2 cm x 3 cm were prepared by cutting the aluminum foils of Examples 1 to 3, Example 6, and Comparative Examples 1 to 4, and their cross sections were observed using a scanning electron microscope (manufactured by JEOL Ltd., model number: JSM-7200F) under conditions of an accelerating voltage of 7.5 kV and a working distance of 10 mm (the observation signal was backscattered electrons), and the thicknesses of the resin layer and the white ink layer were measured. Regarding the thickness, the thickness of each layer was measured at 10 points from the cross-sectional image, and the average value of the data from those 10 points was calculated.

[0049] Furthermore, each of the aluminum foils of Examples 1 to 6 and Comparative Examples 1 to 4 was cut into 30 cm squares to prepare three test pieces, which were then folded in half with the white coating layer side facing outward, i.e., folded 180°. The appearance of the white coating layer at this time was visually observed. If there was no peeling or cracking in the white coating layer of any of the white aluminum foil test pieces after the bending test, it was evaluated as ◯, and if there was even a small amount of peeling or cracking in the white coating layer of any one of the three test pieces, it was evaluated as ×. The results are shown in Table 2 below. From Table 2, it was confirmed that the bending properties (peel resistance) were good in all of the examples, whereas the bending properties (peel resistance) were insufficient in the comparative examples, except for comparative examples 1 and 4.

[0050] [Table 2]

[0051] Furthermore, for the aluminum foils of Examples 1 to 6 and Comparative Examples 1 to 4, the refractive index of each layer was measured in accordance with JIS K7142:2014 (Plastics - Determination of refractive index). The results are shown in Table 3. From the relationship with Table 1, it was confirmed that when the refractive index of the white layer is within a specified range, as in the examples, and the difference between the refractive index of the white coating layer and the refractive index of the intermediate coating layer (refractive index of the white layer - refractive index of the intermediate coating layer) is within a specified range, the whiteness is good in both cases, whereas when it is outside that range, the whiteness is generally insufficient, as in the comparative examples.

[0052] [Table 3]

[0053] The embodiments and examples disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and all modifications and variations within that scope and in a meaning equivalent to the claims are intended to be included. For example, in the embodiment, the white coating layer 12 and the intermediate coating layer 13 are provided on only one side of the white aluminum foil 10, but they may also be provided on both sides. [Explanation of symbols]

[0054] 10 White aluminum foil 11 Main unit 12 White coating layer 13 Middle coat layer

Claims

1. A main body made of aluminum foil; a white coating layer containing a white pigment and a resin laminated on at least one surface of the main body; a colorless intermediate coating layer that contains a resin and does not contain a coloring pigment and is interposed between the main body and the white coating layer; An aluminum foil framed range hood filter or range gap cover, which is formed by press-molding white aluminum foil, and which has a lightness L value of 82 or more as measured in accordance with 5.3.1 c) geometric condition c and 5.3.3 b) method b of JIS Z 8722:2009, Measurement methods of color - Reflected and transmitted object color, on the surface of the main body on which the white coating layer is laminated.

2. 2. An exhaust vent cover, a ventilation fan cover, an aluminum foil framed range hood filter provided with an oil stain prevention filter in a frame body to be attached to a range hood, or a range gap cover, which is obtained by press-molding the white aluminum foil according to claim 1, wherein the resin in the intermediate coating layer contains one or more resins selected from the group consisting of acrylic ester resin, modified epoxy resin, vinyl chloride resin, vinyl acetate resin, and polyester polyol resin.

3. the white pigment in the white coating layer is a titanium dioxide pigment; 3. An exhaust vent cover, a ventilation fan cover, an aluminum foil framed range hood filter provided with an oil stain prevention filter in a frame to be attached to a range hood, or a gap cover for a range, which is obtained by press-molding the white aluminum foil according to claim 1 or 2, wherein the content by weight of titanium dioxide pigment as a solid content in the white coating layer is 30% by weight or more and 80% by weight or less.

4. The average thickness of the intermediate coating layer is 0.5 μm or more and 1.5 μm or less, The white aluminum foil according to any one of claims 1 to 3, wherein the average thickness of the white coating layer is 0.5 μm or more and 2.0 μm or less, is press-molded to form an exhaust vent cover, a ventilation fan cover, or a frame-mounted range hood filter made of aluminum foil, the frame being attached to a range hood. The filter or range gap cover is provided with an oil stain prevention filter.

5. The lightness L value is An exhaust vent cover, a ventilation fan cover, an aluminum foil framed range hood filter provided with an oil stain prevention filter in a frame to be attached to a range hood, or a gap cover for a range, which is obtained by press-molding the white aluminum foil according to any one of claims 1 to 4, wherein the lightness L value of the surface on which the white coating layer is formed is greater than that of a two-layer white aluminum foil in which a white coating layer is formed twice without forming a colorless intermediate coating layer on a comparative aluminum foil base material.

6. The white aluminum foil according to any one of claims 1 to 5, wherein the average thickness of the main body is 20 μm or more and 200 μm or less, is press-molded into an exhaust vent cover, a ventilation fan cover, or a frame to be attached to a range hood. An aluminum foil framed range hood filter or range gap cover provided with an oil stain prevention filter.

7. A main body made of aluminum foil; a white coating layer containing a white pigment and a resin laminated on at least one surface of the main body; a colorless intermediate coating layer that contains a resin and does not contain a coloring pigment and is interposed between the main body and the white coating layer; A white aluminum foil molded body obtained by molding a white aluminum foil, in which the lightness L value measured in accordance with 5.3.1 c) geometric condition c and 5.3.3 b) method b of JIS Z 8722:2009 Color measurement method - Reflected and transmitted object color of the surface on which the white coating layer of the main body is laminated is 82 or more, and the white aluminum foil molded body is a cooking oil protection panel.

Images