JP2022155544A - Colored aluminum foil for cooking - Google Patents

Abstract

To shorten a time required to bake food by imparting a function of positively shortening a time from stopping to re-operating of a heater in an oven toaster to a colored layer in a colored aluminum foil for cooking.SOLUTION: A colored aluminum foil 10 for cooking comprises a colored layer 12 containing heat-resistant resin and carbon black as a black pigment on one surface of a body 11 comprising an aluminum foil, and a surface roughness (Ra) of the colored layer 12 is constituted to be 30-65 nm. When the surface roughness of the colored layer 12 is prescribed in the range, the surface of the colored layer 12 becomes structurally rough while preventing peeling of the colored layer 12 from the body 11, and an apparent surface area is increased so as to increase a heat quantity to be captured and enhance efficiency of heat absorption. As a result of this, a temperature in an oven toaster easily drops, and a time until re-operation of a heater is shortened so as to prolong an operating time of the heater per unit time.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a colored cooking aluminum foil for cooking food, a package comprising the colored cooking aluminum foil, and a method for producing the same.

Conventionally, foods such as sweet potatoes are often wrapped in aluminum foil and heated and cooked using a toaster oven or the like.
At that time, it is also known to use a colored aluminum foil for cooking in which a colored layer containing a black pigment such as carbon black is laminated on one side of a main body made of aluminum foil for wrapping food, as in Patent Document 1. ing.
In such a colored aluminum foil for cooking, since the colored layer absorbs the heat of an oven toaster or the like, the efficiency of cooking with heat is increased compared to an aluminum foil that is not colored (plain foil).

JP 2010-280131 A

By the way, a typical toaster oven is equipped with a thermostat that prevents the temperature inside the oven from rising excessively in order to prevent fires, etc., and the heater stops when the temperature inside the oven rises above a predetermined level. It has become.
When the heat supply from the heater is cut off, the temperature inside the refrigerator drops, and when the temperature drops below a predetermined level, the heater is restarted. When cooking food, the heater is repeatedly operated and stopped.

In this case, the time from when the heater is stopped to when it is restarted does not contribute much to the cooking of the food because the temperature inside the refrigerator is low. Therefore, there is a problem that it takes a long time to bake the food because it is a so-called lost time.

In the colored aluminum foil for cooking of Patent Document 1, the colored layer absorbs heat and the heat is transferred to the food through the aluminum foil, resulting in the temperature inside the oven toaster easily falling, and the falling speed is increased. It can be said that the time until the heater restarts is shortened to a certain extent because it is faster.

However, Patent Literature 1 does not focus on actively shortening the time from stopping the heater in the toaster oven to restarting it. That is, no attempt has been made to shorten the rest time of the heater beyond providing a colored layer on the aluminum foil.

Therefore, the problem to be solved by the present invention is to actively shorten the time from stopping to restarting the heater in the toaster oven, in addition to the endothermic effect derived from the color of the colored layer in the colored aluminum foil for cooking. To shorten the time required for baking food by giving it a function.

In order to solve the above problems, the colored aluminum foil for cooking according to the invention is composed of a main body made of an aluminum foil, and a heat-resistant resin and carbon black as a black pigment laminated on at least one side of the main body made of the aluminum foil. and a colored layer containing the colored layer, and the surface roughness (Ra) of the colored layer is 30 to 65 nm.

As described above, the colored aluminum foil for cooking according to the invention is configured such that the surface roughness (average roughness Ra) in the colored layer containing carbon black as a black pigment is 30 nm or more, so the colored layer The surface of is structurally roughened and the apparent surface area is increased. Therefore, the amount of heat captured from the heater to the surface of the colored layer increases (the amount of heat reflected decreases).
For this reason, the heat absorption efficiency of the colored aluminum foil for cooking is increased, the heat is transferred to the food, the temperature inside the toaster oven can be easily lowered, the time until the heater restarts is shortened, and the You can extend the operating time of the heater. As a result, the time required for baking the food can be shortened.

In addition, as described above, the colored aluminum foil for cooking according to the invention is configured such that the surface roughness of the colored layer containing carbon black as a black pigment is 65 nm or less, so that the surface of the colored layer has a structure. It is possible to prevent the coloring layer from peeling off from the main body made of aluminum foil due to excessive roughening.
Therefore, it is possible to maintain the function of actively shortening the time from stopping the heater until it is restarted, and maintain the function of shortening the time required for baking the food.

In the colored aluminum foil for cooking according to the invention, it is preferable to employ a configuration in which the carbon black accounts for 15 to 70% by weight in the colored layer.

By setting the content of carbon black in the colored layer within the above range, it becomes easier to adjust the surface roughness of the surface of the colored layer to the roughness within the predetermined range.
If the carbon black content is less than 15% by weight, the proportion of the heat-resistant resin becomes excessive and the structure of the colored layer becomes too fine, making it difficult to increase the surface roughness.
On the other hand, when the content of carbon black exceeds 70% by weight, the ratio of the heat-resistant resin having a role of binding carbon black in the colored layer becomes small, the structure of the colored layer becomes too rough, and the colored layer becomes aluminum. It becomes easy to separate from the main body made of foil.

In the colored aluminum foil for cooking according to the invention, it is preferable to employ a structure in which carbon black has an average particle size of 10 to 90 nm in the colored layer. The average particle diameter as used herein means an arithmetic average diameter obtained by observing the cross section of the colored layer with an electron microscope and randomly selecting 100 carbon black particles in the colored layer.

By setting the average particle size of the carbon black in the colored layer within the above range, it becomes easier to adjust the surface roughness of the surface of the colored layer to the roughness within the predetermined range.
When the average particle size of carbon black is less than 10 nm, it tends to aggregate and is difficult to use as a pigment. In addition, the particles are too fine, the structure of the colored layer becomes minute, and it becomes difficult to increase the surface roughness.
In addition, when the average particle size of carbon black exceeds 90 nm, it becomes bulky and it is difficult to increase the content of carbon black in the colored layer. As a result, the proportion of the heat-resistant resin increases and the surface roughness of the colored layer increases become difficult to do.

In the colored aluminum foil for cooking according to the invention, the main body made of the aluminum foil has a glossy surface on one side and a poppy surface on the other side, and the colored layer is laminated on the poppy surface of the main body. It is preferable to adopt a configuration in which

By laminating the colored layer on the poppy surface side of the main body made of aluminum foil, the surface roughness of which is larger than that of the glossy surface, the degree of adhesion of the colored layer to the main body is improved, and the colored layer is peeled off from the main body. is prevented.
In addition, by laminating the colored layer on the side of the poppy surface, the surface properties of the poppy surface with large surface roughness are reflected, and the surface roughness of the colored layer becomes relatively large. easier.

In the colored aluminum foil for cooking according to the invention, it is preferable that the colored layer has a coating amount of 0.5 to 5.0 g/m ² of the colored coating film after drying.

By setting the coating amount in the colored layer within the above range, it becomes easier to adjust the surface roughness of the colored layer to the roughness within the predetermined range.
If the coating amount is less than 0.5 g/m ² , it becomes difficult to form a coating film, the colored layer tends to peel off from the main body, and the colored layer becomes too thin, so that the heat absorption effect may not be sufficiently obtained. There is
When the coating amount exceeds 5.0 g/m ² , the thickness of the coating film increases and the smoothness of the surface increases, making it difficult to increase the surface roughness of the surface.

In the colored aluminum foil for cooking according to the invention, the food to be cooked is sweet potato, and it is preferable to use it for baking baked sweet potato.

By using the colored aluminum foil for cooking baked sweet potatoes, it is possible to bake baked sweet potatoes with high sugar content and rich sweetness in a short time.

In the colored aluminum foil for cooking according to the invention, the colored layer is laminated only on one surface of the main body made of the aluminum foil, and the release coat layer laminated on the other surface of the main body made of the aluminum foil. can be adopted.

When the aluminum foil for cooking is used so that the food is in contact with the surface on which the release coat layer is laminated during cooking, the action of the release coat layer suppresses the adhesion of the food to the colored aluminum foil for cooking. can be done.

In the colored aluminum foil for cooking according to the invention, it is preferable that the release coat layer is made of one or more selected from wax, silicone resin, acrylic resin, urethane resin, ethyl cellulose resin, and mineral oil. .

By configuring the release coat layer as described above, it is possible to make the release coat layer resistant to denaturation even by heat during cooking and to have good heat resistance.

In order to solve the above-described problems, the package according to the invention is made of the colored aluminum foil for cooking.

By configuring the package as described above, it is possible to shorten the time required for baking the food.

In order to solve the above-described problems, the method for producing a colored aluminum foil for cooking according to the invention includes the steps of preparing an aluminum foil that will be the main body, and applying the heat-resistant resin and the black pigment on at least one side of the aluminum foil. a step of applying an ink containing carbon black; and a step of heating the aluminum foil coated with the ink to form a colored layer, wherein the step of forming the colored layer is performed by heating the aluminum foil coated with the ink. A preheating step of heating the aluminum foil at a first temperature, and then a main heating step of heating the aluminum foil coated with the ink at a second temperature higher than the first temperature. of.

When the aluminum foil coated with ink is heated to evaporate the ink solvent and form a colored layer, if the solvent is suddenly heated to a high temperature, the solvent will evaporate rapidly, causing unexpected cracks in the coating film. Therefore, it becomes difficult to adjust the surface roughness of the colored layer after completion to the above range. In addition, the occurrence of film cracking makes it easier for the colored layer to separate from the main body after completion.
Heating is divided into two stages, a preheating process and a main heating process. In the preheating process, most of the solvent is blown off at a low temperature, and in the main heating process, the colored layer is baked at a high temperature. It becomes easy to adjust the surface roughness of the layer within the above range, and the peeling of the colored layer from the main body is prevented.

In the method for producing a colored aluminum foil for cooking according to the invention, the preheating step is performed at a heating temperature of 50 to 100° C. for a heating time of 3 to 9 seconds, and the main heating step is performed at a heating temperature of 180 to 180. It is preferable to employ a configuration in which the heating is performed under conditions of 220° C. and a heating time of 0.5 to 5 seconds. Furthermore, the preheating step is performed at a heating temperature of 60 to 80° C. for a heating time of 3 to 5 seconds, and the main heating step is performed at a heating temperature of 190 to 210° C. for a heating time of 0.5 to 2 It is preferable to adopt a configuration that operates under conditions of 0.4 seconds.

By constructing a drying zone or the like for the preheating process and performing it at a low temperature for a relatively long time in it, most of the solvent can be slowly evaporated so as not to cause film cracking, and the main heating process can be performed using a hot drum or the like. By using it at a higher temperature than the preheating process and for a short time than the preheating process, but for a time sufficient for drying and curing the heat-resistant resin, the colored layer is baked and a strong colored layer is formed and deteriorates. Therefore, it becomes easier to adjust the surface roughness of the colored layer within the above range, and separation of the colored layer from the main body is further prevented. In addition, as long as the effect of the present invention can be obtained, the main heating process may be performed for a longer period of time than the preheating process.

Since the colored aluminum foil for cooking according to the invention is configured as described above, the colored layer has the function of actively shortening the time from stopping the heater in the oven toaster to restarting, and the time required for baking food. It was possible to shorten the time.

Sectional view of the colored aluminum foil for cooking of the embodiment The perspective view which shows the usage condition of the colored aluminum foil for cooking of embodiment. Sectional view of colored aluminum foil for cooking of another embodiment Schematic diagram showing the state of use of the colored aluminum foil package for cooking of still another embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The colored aluminum foil 10 for cooking of the embodiment shown in FIG. ) is defined within a predetermined range.
As shown in FIG. 2, the colored layer 12 is on the outside and the main body 11 is on the inside (the side that comes in contact with the food), and the food F such as sweet potato is wrapped and used for heating and cooking in an oven toaster O or the like.

As the aluminum foil of the main body 11, a known aluminum foil can be used, and although it is not particularly limited, an 8000 series (8011, etc.) aluminum foil can be used, for example. Any of a hard material, a semi-hard material, and a soft material can be used for refining.

Although the thickness of the aluminum foil of the main body 11 is not particularly limited, it is preferably about 10 to 30 μm.
If the thickness is less than 10 μm, it is too thin and may break when the food F is wrapped, making it difficult to form a colored layer. On the other hand, when the thickness exceeds 30 μm, it is too thick to wrap the food F, and when wrapped, a space is likely to be generated between the food F and the heat transfer efficiency is reduced.
As will be described later, the thickness of the aluminum foil is not particularly limited when the colored aluminum foil 10 for cooking is used to form the colored aluminum foil package 10' for cooking, but the thickness of the aluminum foil is preferably 30 μm or more and 250 μm or less, and more preferably 50 μm or more and 150 μm. More preferably:
If the thickness is less than 30 μm, when the package 10 ′ such as a container is formed from the colored aluminum foil for cooking, the strength of the package 10 ′ may be lowered and the package 10 ′ may be deformed. Moreover, if the thickness exceeds 250 μm, it may be difficult to mold the container.

One surface of the aluminum foil of the main body 11 is a glossy surface (glossy noodles) and the other surface is a poppy surface (matte surface), like those generally available on the market.
The surface roughness of the poppy surface is larger than that of the glossy surface, and the colored layer 12 is formed on the poppy surface side.
The surface roughness (Ra) of the poppy surface is not particularly limited, but is preferably 0.2 μm or more, more preferably 0.25 μm or more. When the surface roughness is within such a range, the adhesion of the colored layer 12 to the main body 11 is improved, and peeling or the like is less likely to occur. easier to adjust.

The colored layer 12 contains a heat-resistant resin and carbon black as a black pigment. In addition, a dispersing agent or the like may be contained.
The type of heat-resistant resin is not particularly limited, but examples include polyamideimide resin, acrylic resin, epoxy resin, and polyethersulfone resin. Polyamideimide resin is preferable in terms of chemical resistance, oil resistance, abrasion resistance, and the like. . Although the content of the heat-resistant resin in the colored layer 12 is not particularly limited, 30 to 85% by weight can be exemplified. More preferably, the content of the heat-resistant resin is 40% by weight to 80% by weight.
The method for forming the colored layer 12 is not particularly limited, but it is formed by a dry coating film of ink containing a heat-resistant resin and carbon black as a black pigment.
The printing method or application method is not particularly limited, but examples of printing methods include gravure printing, screen printing, and calender printing, and examples of application methods include spray coating, brush coating, and roller coating.
After printing or applying ink by these methods, the colored layer 12 is formed by drying the coating film.
Here, the solvent for the ink is not particularly limited, but alcohol solvents such as ethanol, alkylamide solvents such as dimethylacetamide, ketone solvents such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, N-methyl-2 Pyrrolidone-based solvents such as -pyrrolidone, and ether-based solvents such as diethyl ether and tetrahydrofuran can be exemplified.

As shown in FIG. 1, the colored layer 12 is adjusted so that its surface 12a, that is, the surface opposite to the surface in contact with the main body 11, has a relatively large surface roughness (Ra) of 30 to 65 nm ( It should be noted that FIG. 1 is only a schematic diagram, and does not accurately depict the size of unevenness of the surface 12a.
More preferably, the surface roughness (Ra) of the surface 12a of the colored layer 12 is adjusted to 35-57 nm, and more preferably 45-57 nm.
Such adjustment is realized by appropriately adjusting the content of carbon black as a black pigment, the average particle size, the coating amount of the coating film, and the drying process of the coating film, as will be described later.
Since the colored layer 12 is laminated on the poppy surface side of the main body 11, the surface properties of the poppy surface having large surface roughness are reflected, and the surface roughness of the colored layer 12 naturally increases. Therefore, the surface roughness of the colored layer 12 can be easily adjusted within the predetermined range.
By adjusting the surface roughness of the colored layer 12 to such a range, the colored layer 12 is prevented from being peeled off from the main body 11, and the endothermic efficiency of the colored layer 12 is increased, and the food F is heated and cooked in the oven toaster O. In this case, the time from stopping the heater to restarting is shortened, and the heating efficiency of the food F is improved.

The content of carbon black in the colored layer 12 is not particularly limited, but is preferably 15 to 70% by weight, more preferably 20 to 60% by weight.
Carbon black is a good absorber of heat from the toaster oven heater.
If the carbon black content is less than 15% by weight, the proportion of the heat-resistant resin becomes excessive and the structure of the colored layer 12 becomes too fine, making it difficult to increase the surface roughness.
On the other hand, if the content of carbon black exceeds 70% by weight, the ratio of the heat-resistant resin having a role of binding the carbon black in the colored layer 12 becomes small, and the structure of the colored layer 12 becomes too rough. 12 can be easily peeled off from the main body made of aluminum foil.

The average particle size of carbon black in the colored layer 12 is not particularly limited, but is preferably 10 to 90 nm, more preferably 20 to 50 nm.
If the average particle size of carbon black is less than 10 nm, it tends to aggregate and is difficult to use as a pigment. In addition, the particles are too fine, the structure of the colored layer 12 becomes fine, and it becomes difficult to increase the surface roughness.
In addition, when the average particle size of carbon black exceeds 90 nm, it becomes bulky and it is difficult to increase the content of carbon black in the colored layer 12. As a result, the proportion of the heat-resistant resin increases, and the surface of the colored layer 12 It becomes difficult to increase the roughness.

^The thickness of the colored layer ¹² is not particularly limited. more preferably 0.7 to 0.9 g/m ² .
If the coating amount is less than 0.5 g/m ² , it becomes difficult to form a coating film, the colored layer 12 tends to peel off from the main body, and the colored layer 12 becomes too thin to obtain a sufficient heat absorbing effect. There is a possibility that it will not.
When the coating amount exceeds 5.0 g/m ² , the thickness of the coating film increases and the smoothness of the surface increases, making it difficult to increase the surface roughness of the colored layer 12 .

The mode of the drying treatment of the coating film in the colored layer 12 is not particularly limited, and heat drying and natural drying can be exemplified, but two-stage heat drying is preferable.
That is, the preferable heating and drying process includes a preheating process of heating the main body 11 coated with ink at a first temperature T1, and then a preheating process of heating the main body 11 coated with ink at a second temperature higher than the first temperature T1. and a main heating step of heating at T2.
The preheating step is performed, for example, in a drying booth or drying zone, and the main heating step is performed, for example, in hot drums.
Heating is divided into two stages, a preheating process and a main heating process. In the preheating process, most of the solvent is evaporated at a low temperature T1, and in the main heating process, the colored layer 12 is baked at a high temperature T2, so that film cracking is less likely to occur. Become.
Therefore, it becomes easier to adjust the surface roughness of the colored layer 12 within the above range, and separation of the colored layer 12 from the main body 11 is prevented.

The heating time and heating temperature in the preheating step and the main heating step are not particularly limited. It is preferable that the heating temperature T2 is 180 to 220° C. and the heating time is 0.5 to 5 seconds.
By performing the preheating process at a relatively low temperature for a long time, most of the solvent can be evaporated slowly so as not to cause film cracking, and the main heating process is performed at a higher temperature than the preheating process and for a shorter time than the preheating process. However, if the heat-resistant resin is dried and cured for a sufficient period of time, it is possible to prevent the colored layer from being baked and deteriorated.
Therefore, it becomes easier to adjust the surface roughness of the surface of the colored layer 12 within the above range, and the separation of the colored layer 12 from the main body 11 is further prevented. In addition, as long as the effect of the present invention can be obtained, the main heating process may be performed for a longer period of time than the preheating process.

Another embodiment of the colored aluminum foil 10 for cooking is shown in FIG.
In this embodiment, a main body 11 made of aluminum foil has a colored layer 12 on one side and a release coating layer 13 laminated on the other side.
During use, the food F is brought into contact with the surface on which the release coat layer 13 is laminated, so that the food F is heated and cooked.
When the colored aluminum foil 10 for cooking is removed from the food F after cooking, the release coat layer 13 can prevent the food F from adhering to the colored aluminum foil 10 for cooking.
This keeps the appearance of the food after cooking. Also, so-called food loss can be reduced.

The release coating layer 13 is not particularly limited as long as it has release properties, but it is preferable to have a heat resistance that is resistant to denaturation even by heat during cooking.
Examples thereof include waxes (vegetable waxes, animal waxes, mineral waxes, petroleum waxes, synthetic waxes, etc.), silicone resins, fluorine resins, acrylic resins, urethane resins, ethyl cellulose resins, mineral oils, and combinations thereof. .
The method of forming the release coat layer 13 is not particularly limited, and it can be formed on the opposite side of the main body 11 from the colored layer 12 by a method such as coating or extrusion.
The coating amount of the release coating layer 13 is not particularly limited, but is preferably 0.01 g/m ² to 2.5 g/m ² , more preferably 0.02 g/m ² to 1.0 g/m ² . If the coat amount is less than 0.01 g/m ² , it becomes difficult to stably form the release coat layer 13, and if it exceeds 2.5 g/m ² , the film thickness becomes too thick and the cost increases. is.

FIG. 4 shows a package 10' made of colored aluminum foil for cooking according to the embodiment of FIG.
The type of the colored aluminum foil package 10' for cooking is not particularly limited as long as the food F can be accommodated therein.
That is, as shown in FIG. 4(a), it may be a sheet on which food F can be placed, or on which food F can be wrapped in a bag shape, as shown in FIG. 4(b). As in c), it may be formed into a container shape capable of accommodating the food F. In this embodiment, one surface of the main body 11 is provided with the colored layer 12, and the other surface is laminated with the release coat layer 13. As shown in FIG.

As shown in FIGS. 4(a) and 4(b), in the colored aluminum foil package 10' for cooking, when simply using a sheet-like one, a sheet-like package as shown in FIG. 4(a) is used. The food F may be placed on the side of the release coat layer 13 in a state of being spread out and used as it is ("packaging" as used herein includes placing), As shown in (b), the food F may be contained in the central portion of the sheet so that the release coat layer 13 side faces inward, and the food F may be wrapped in a bag. When the food F is to be wrapped in a bag, the colored aluminum foil package 10' for cooking may be of a size that allows it.

As shown in FIG. 4(c), when the colored aluminum foil package 10' for cooking is in the shape of a container, the colored layer 12 is formed in advance on the required portion of the colored aluminum foil 10 for cooking, and then pressed. It may be prepared by forming into a container shape by molding, or by forming a colored layer 12 at a necessary location after molding a pure metal foil on which the colored layer 12 is not formed into a container shape by press molding. It is good by
Here, as shown in FIG. 4(c), the shape of the container as the colored aluminum foil package 10' for cooking is not particularly limited. A rectangular shape such as a rectangular shape, a circular shape (including an elliptical shape), and the like can be mentioned.
However, it is preferable to have at least a bottom wall 14, a peripheral wall 15 rising from the bottom wall 14, and optionally a flange 16, as shown in FIG. 4(c).
In addition, if necessary, the bottom wall 14 and the peripheral wall 15 of the container may be provided with irregularities, ribs, rims, or the like.

Hereinafter, the contents of the present invention will be further clarified by giving Examples and Comparative Examples of the present invention.

First, Examples 1 to 15 were prepared. In each example, an aluminum foil (8011 material, thickness 12 μm) was used as the main body of the colored aluminum foil for cooking, and ink was applied to the poppy surface and dried by heating to form a colored layer.

Here, the ink is a polyamideimide resin solution (Viromax manufactured by Toyobo Co., Ltd., Viromax and Viromax, manufactured by Toyobo Co., Ltd.) containing 15% by weight of solid content of polyamideimide resin as a heat-resistant resin and 85% by weight of N-methyl-2-pyrrolidone (NMP). is a registered trademark) and carbon black (CB) as a black pigment, and tetrahydrofuran (THF), N-methyl-2-pyrrolidone (NMP), and cyclohexanone are used as ink diluents to adjust the viscosity during coating. Using.
The coating weight of the colored layer was 0.7-0.9 g/m ² .
In addition, heat drying is performed in two stages: a preheating process performed in a drying zone at a heating temperature of 60 to 80 ° C. for a heating time of 3.6 seconds, and a main heating process performed in a hot drum at a heating temperature of 200 ° C. for a heating time of 0.9 seconds. It was carried out separately.
Here, the average particle size, content and surface roughness of carbon black in the colored layer in each example are shown in Table 1 below. The average particle diameter is the arithmetic average diameter obtained by randomly selecting 100 carbon black particles in the colored layer by observing the cross section of the colored layer with an electron microscope, and the surface roughness is manufactured by Oxford Instruments. , MFP-3D-SA atomic force microscope (AFM: Atomic Force Microscope) and AC160TS (equivalent to spring constant 3N/m) are used for the depth stylus, and the measurement area is 5μ square in tapping mode measurement, and the measurement atmosphere is the air. It is the average roughness (Ra) obtained by measuring under the conditions of room temperature (25° C.) under atmospheric conditions. In addition, almost all of the colored layer after drying was composed of polyamide-imide resin except for carbon black.

Further, as Comparative Example 1, an aluminum foil (8011 material, thickness 12 μm) similar to that of the example was prepared without the colored layer.
Furthermore, as Comparative Examples 2 to 5, the same aluminum foil (8011 material, thickness 12 μm) as in Examples was used, and ink was applied to the poppy surface and dried by heating to form a colored layer.
Here, the ink is a polyamideimide resin solution (Viromax manufactured by Toyobo Co., Ltd., Viromax and Viromax, manufactured by Toyobo Co., Ltd.) containing 15% by weight of solid content of polyamideimide resin as a heat-resistant resin and 85% by weight of N-methyl-2-pyrrolidone (NMP). is a registered trademark) and carbon black as a black pigment, and tetrahydrofuran (THF), N-methyl-2-pyrrolidone (NMP), and cyclohexanone were used as ink diluents for adjusting the viscosity during coating.
The coating weight of the colored layer was 0.7-0.9 g/m ² .
Heat drying was carried out using a hot drum at a heating temperature of 180° C. for a heating time of 30 seconds.
Here, the average particle size, content, and surface roughness of carbon black in the colored layers in Comparative Examples 2 to 5 were as shown in Table 2 below (the meaning of the average particle size and surface roughness is the same as in Examples). . In addition, almost all of the colored layer after drying was composed of polyamide-imide resin except for carbon black.

Using the specimens of these Examples and Comparative Examples, a sweet potato baking experiment was conducted using a toaster oven.
As the toaster oven, ET-UB22 manufactured by Zojirushi Mahobin Co., Ltd., and as the sweet potato, a plurality of sweet potatoes having a length of about 15 cm, a cross-sectional diameter of about 4 cm, and a weight of about 90 g were prepared so that the dimensions and weights were roughly the same. .
The oven toaster was set to 1000 W, ignoring the difference in rise, and kept turning the dial so as not to turn off in order to always operate.
Since the ON/OFF cycle of the heater stabilized after 4 cycles, the samples of Examples and Comparative Examples were wrapped in a spindle shape so that there were not many gaps, and placed in the center of the heating net in the chamber at the timing when the heater was turned off. , the sweet potato was heated and cooked for a period of time during which the ON/OFF cycle of the heater was repeated seven times, and the state of the finished roasted sweet potato was observed.
The results are shown in Table 3 below.
In Table 3, 〇 indicates that the bamboo skewer can be inserted into the baked potato smoothly, △ indicates that there is no problem if the bamboo skewer is inserted into the baked potato, but there is no problem in eating it, and × indicates that the bamboo skewer is inserted into the baked potato. When the baked sweet potato is pierced, the resistance is large and the baking is insufficient.
From Table 3, it was confirmed that the baked sweet potato was baked to the extent that there was no problem with eating at least in the samples of any of the examples.

Next, using the specimens of these Examples and Comparative Examples, a rubbing fastness test of the colored layer was carried out.
The rubbing fastness test conforms to the JIS L 0849 color fastness test method to rubbing, using a friction tester type II, rubbing the surface of the colored layer side of each specimen 100 times back and forth, and the colored layer peels off, It was confirmed whether the surface of the aluminum foil could be seen.
Here, the friction body was a dry white cloth made of cotton, and in order to prevent uneven friction, the white cotton cloth was doubled and fixed to the tester, and the sample was attached thereon.
The results are shown in Table 4 below.
In Table 4, ◯ means that the colored layer does not peel off and the surface of the aluminum foil cannot be seen, △ means that the colored layer has slight peeling of 10% or less of the surface area, and × means that the colored layer has 10% of the surface area. %, and ○ or △ satisfies the acceptance criteria.
As shown in Table 4, it was confirmed that the colored layer was not peeled off, which would hinder the use of the samples of any of the examples.

As can be seen from Tables 3 and 4, all the specimens of the comparative examples have at least one test result of the baking confirmation test or the rubbing fastness test, whereas the results of any of the examples are x. The test results of the baking confirmation test and the rubbing fastness test were 0 or △ for the specimen, confirming that the peeling prevention of the colored layer and the shortening of the baking time are compatible.
Among the examples, the test results of both the baking confirmation test and the rubbing fastness test were ◯ in Examples 3 to 5, Examples 8 and 9, and Examples 11 and 12.

Next, using the specimens of Examples 1 and 5 and Comparative Example 1, a verification experiment of the ON/OFF cycle of the heater attached to the oven toaster was conducted.
Using the same oven toaster and sweet potato as in the above sweet potato baking experiment,
The heating power was set to 1000 W, and after 4 cycles when the ON/OFF cycle of the heater was stabilized, the sweet potatoes were wrapped with the specimens of Examples 1 and 5 and Comparative Example 1 so that there were not many gaps. Installed in the center of the heating net inside the refrigerator.
The ON/OFF cycles of the heater were then continued seven times, the off and on times of the heater were measured, and the average value for the 2nd to 7th ON/OFF cycles was calculated.
The results are shown in Tables 5-7. Table 5 shows the results of Example 1, Table 6 shows the results of Example 5, and Table 7 shows the results of Comparative Example 1, respectively.
As can be seen from each table, in the sample of the example, the pause time of the heater was shorter than that of the sample of the comparative example. confirmed.

Furthermore, a silicone resin (addition reaction type silicone (trade name: SD7333, Toray Dow Corning (manufactured by Toray Co., Ltd.) and a catalyst (trade name: SRX212, manufactured by Dow Corning Toray) in a coating amount of 0.05 g/m ² ) and dried to form a release coat layer. Then, Example 16, Example 17, and Example 18 were prepared in order.
Similarly, a silicone resin (addition reaction type silicone (trade name: SD7333, manufactured by Dow Corning Toray Co., Ltd.)) was applied to the surface (glossy surface) of the samples of Comparative Examples 2 and 3 on the side where the colored layer was not formed. and a catalyst (trade name: SRX212, manufactured by Dow Corning Toray Co., Ltd.) in a coating amount of 0.05 g/m ² ), respectively, and dried to form a release coat layer. Comparative Examples 7 and 8 were prepared.
In addition, as Comparative Example 6, the same sample as in Comparative Example 1, that is, the surface on which the colored layer was not formed, was prepared without a release coat layer, and as a reference example, Example 3 and A similar sample was prepared, that is, the surface on which the colored layer was not formed (glossy surface) was not formed with a release coating layer.

Using the specimens of these Examples, Comparative Examples and Reference Examples, a rice cake baking experiment was conducted using a toaster oven.
An ET-UB22 manufactured by Zojirushi Mahobin Co., Ltd. was prepared as a toaster oven, and a square cut rice cake (50 g) manufactured by Sato Foods Co., Ltd. under the trade name of "Cristo Slit" was prepared as a rice cake.
After cutting the samples of Examples 16 to 18, Comparative Examples 6 to 8, and Reference Example to a size that fits in the toaster oven, each sample is spread into a sheet to form a colored layer. After laying it on the tray attached to the oven toaster so that the non-stick side (glossy side) faces upward, place the rice cake on that side, set the heat of the toaster oven to 1000 W, and heat for 3 minutes. did. Then, the appearance of the baked mochi after heating and the condition when the mochi was split in half were observed.
The results are shown in Table 8 below.
In Table 8, ◎ indicates that most of the mochi is browned and the inside of the mochi is soft and can be eaten. X means that the inside of the mochi is soft and edible, and x means that the mochi is not browned and the inside is hard and cannot be eaten.

Similarly, using the specimens of these Examples, Comparative Examples and Reference Examples, a rice cake peeling test was conducted.
After being heated as described above, the mochi was picked up with chopsticks and pulled up, and the peelability between the mochi and the sample was observed.
The results are shown in Table 8 below.
In Table 8, ◯ means that the rice cake was peeled off from the sample, and X means that the rice cake was not peeled off from the sample and the sample stuck to it.

Furthermore, using the specimens of these Examples, Comparative Examples, and Reference Examples, in the same manner as in Examples 1 to 15 and Comparative Examples 1 to 5, the specimens before heating were subjected to a rubbing fastness test. evaluated similarly.
The results are shown in Table 8 below.

As can be seen from Table 8, in all samples of the comparative examples, the results of at least one of the baking confirmation test, the peelability test, and the rubbing fastness test are x, whereas any of the examples , the test results of the baking confirmation test, peelability test, and rubbing fastness test are ◎ or 〇, and the prevention of peeling of the colored layer, the improvement of peelability, and the reduction of the baking time are all satisfied. It was confirmed that

The embodiments and examples disclosed this time are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims, and includes all modifications and variations within the scope of the claims and equivalents thereof.

For example, in the embodiments and examples, the colored layer 12 is formed only on one side of the main body 11 of the colored aluminum foil 10 for cooking, but the colored layer 12 can also be formed on both sides of the main body 11 .
Further, in the embodiments and examples, the colored layer 12 is formed on the poppy surface of the main body 11, but the colored layer 12 can also be formed on the glossy surface.
In the embodiments and examples, the colored layer 12 is formed on the entire surface of one side of the main body 11 of the colored aluminum foil 10 for cooking. There may be non-colored areas of
In the embodiments and examples, a sweet potato was given as an example of the food F to be wrapped in the colored aluminum foil 10 for cooking and cooked, but the type of the food F is not limited to this.
In the embodiments and examples, the toaster oven O was exemplified as the device for cooking the food F, but the device is not limited to this, and may be an oven range or the like.
In the embodiments and examples, the drying treatment process of the coating film in the colored layer 12 is performed by two stages of heat drying. , or a multi-stage heating and drying process of three or more stages.

10 Colored aluminum foil for cooking 10' Colored aluminum foil package for cooking 11 Main body 12 Colored layer 12a Colored layer surface 13 Release coat layer 14 Bottom wall 15 Peripheral wall 16 Flange F Food O Oven toaster

Claims (11)

A colored aluminum foil for cooking for wrapping or wrapping food and cooking it with an oven toaster, etc.
a main body made of aluminum foil;
A colored layer containing carbon black as a heat-resistant resin and a black pigment, laminated on at least one side of the main body made of the aluminum foil,
A colored aluminum foil for cooking, wherein the colored layer has a surface roughness (Ra) of 30 to 65 nm. In the colored layer,
The colored aluminum foil for cooking according to claim 1, wherein the carbon black accounts for 15-70% by weight. In the colored layer,
The colored aluminum foil for cooking according to claim 1 or 2, wherein the carbon black has an average particle size of 10 to 90 nm. The main body made of the aluminum foil has a glossy surface on one side and a poppy surface on the other side,
The colored aluminum foil for cooking according to any one of claims 1 to 3, wherein the colored layer is laminated on the poppy surface of the main body. The colored aluminum foil for cooking according to any one of claims 1 to 4, wherein the colored layer has a coating amount of 0.5 to 5.0 g/m ² of a colored coating film after drying. the food is sweet potato;
The colored aluminum foil for cooking according to any one of claims 1 to 5. The colored layer is laminated only on one surface of the main body made of the aluminum foil,
The colored aluminum foil for cooking according to any one of claims 1 to 6, further comprising a release coat layer laminated on the other surface of the main body made of said aluminum foil. 8. The colored aluminum foil for cooking according to claim 7, wherein the release coat layer is made of one or more selected from wax, silicone resin, acrylic resin, urethane resin, ethyl cellulose resin, and mineral oil. A colored aluminum foil package for cooking, comprising the colored aluminum foil for cooking according to any one of claims 1 to 8. A method for producing a colored aluminum foil for cooking according to any one of claims 1 to 8,
A step of preparing an aluminum foil to be the main body;
a step of applying ink containing the heat-resistant resin and carbon black as a black pigment to at least one side of the aluminum foil;
A step of heating the aluminum foil coated with the ink to form a colored layer,
The step of forming the colored layer includes
a preheating step of heating the aluminum foil coated with the ink at a first temperature;
Next, a main heating step of heating the aluminum foil coated with the ink at a second temperature higher than the first temperature. The preheating step includes
The heating temperature is 50 to 100° C. and the heating time is 3 to 9 seconds,
The main heating step is
The method for producing a colored aluminum foil for cooking according to claim 10, wherein the heating temperature is 180 to 220°C and the heating time is 0.5 to 5 seconds.

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