JPH052414Y2 - - Google Patents

Description

[Detailed explanation of the idea]

INDUSTRIAL APPLICATION FIELD This invention relates to a heat-resistant aluminum container for food and drink that is used while being exposed to high temperatures, such as an aluminum pan for frying. In this specification, the term aluminum is used to include aluminum alloys. BACKGROUND TECHNOLOGY Conventionally, aluminum containers for food and beverages as described above have been made by molding an aluminum base material into a dish or cup shape, with the aluminum base exposed. Problems that the invention aims to solve However, such containers cannot be used for storing food, etc.
During storage, there was a drawback that the container was easily corroded by moisture, salt, acid, etc. contained in the container contents.
Furthermore, when containers stored in a stack are taken out one by one, the aluminum surface has poor slipperiness, so the containers tend to stick together and move, making it difficult to take them out. Alternatively, when forming containers, lubricating oil must be applied to the surface of the aluminum base material to improve formability, making the forming process troublesome, and furthermore, the lubricating oil must be removed after forming for food hygiene reasons. However, there were also drawbacks such as the fact that the work was increasingly troublesome. However, containers with vinyl coating on the inner surface are also available to prevent corrosion caused by the contents of the container, but in this case, they cannot be heated in a microwave, oven, open flame, etc. while the contents are still inside. When this is done, the resin decomposes due to heat, causing problems such as discoloration and blackening of the resin, and even smoke generation. This invention was developed in view of this technical background, and it prevents corrosion caused by container contents, discoloration during heating, and smoke generation, and improves the ease of removing stacked containers by improving slipperiness. The object of the present invention is to provide an aluminum container for food and beverages, which does not require lubricating oil during molding. Means for Solving the Problems According to this invention, as shown in FIGS. 1 and 2, a zirconium compound, monoolefin or olefin polymer, and a mixed film 3 of a polymer having a hydroxyl group or a carboxyl group
The gist of the present invention is a heat-resistant aluminum container 4 for food and beverages, characterized in that it is coated with zirconium in a prescribed amount of 30 mg/m ² or more. The aluminum base material 1 constituting the container body 2 is
The composition is not particularly limited as long as it has the strength, moldability, and other properties required as a container for food and drink. The mixed film 3 is formed by applying a treatment liquid in which a zirconium compound, a monoolefin or an olefin polymer, and a polymer having a hydroxyl group or a carboxyl group are mixed in the state of an aqueous solution or an emulsion, and a drying process. be. Examples of the zirconium compound include alkali metal salts and ammonium salts of ammonium zirconium carbonate and fluorozirconate. In addition, monoolefins or olefin polymers include ethylene, propylene,
-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butene,
3-methyl-1-butene, 2-methyl-2-butene,
1-hexene, 2,3-dimethyl-2-butene,
1-heptene, 1-octene, 1-nonene, 1-
Desene etc. can be mentioned. Among them, it is preferable to use ethylene and propylene. Examples of polymers having hydroxyl or carboxyl groups include polyacrylic acid, polyvinyl alcohol, cellulose hydroxyethyl ether, ethylene maleic anhydride, polyvinylpyrrolidine, and polyvinylmethyl ether. Examples include acrylic copolymer latex.
Among these, polyacrylic acid is preferred. Here, the mixing ratio of the above three components is preferably 10 to 95 parts, more preferably 60 to 90 parts for the monoolefin or olefin polymer. The addition of monoolefin or olefin polymer is particularly useful for improving the moldability of the film itself, but if it exceeds 95 parts, it will no longer be a water-soluble resin. 5 to 50 parts for polymers having hydroxyl or carboxyl groups;
More preferably, the amount is 10 to 40 parts. The ratio of the zirconium compound is 1 zirconium to the total of both polymers.
The amount is preferably 0.5 to 10 parts, more preferably 1 to 5 parts. Further, as a method for applying the treatment liquid for forming a mixed film onto the surface of the aluminum substrate, any method such as a spray method, a dipping method, a roll coating method, a brush coating method, etc. can be adopted. Also, drying after coating is
It is desirable to carry out at a temperature of about 15 to 300°C. Drying time varies depending on the drying temperature, for example at 200℃
It is best to do this for about 10 seconds. However, in this invention, it is required that the mixed coating 3 be formed in such a manner that the amount of zirconium deposited is 30 mg/m ² or more. Zirconium contributes to improving corrosion resistance, but at 30 mg/m ²
If it is less than that, the effect will be poor. On the other hand, if the amount is increased, the effect will not be particularly increased, but rather the cost will increase due to wasted materials, so the preferred deposition range is 30 to 100 mg/m ² . The amount of zirconium deposited may be set by adjusting the mixing ratio of the zirconium compound and the monoolefin or olefin polymer and the polymer having a hydroxyl group or carboxyl group during the production stage of the treatment liquid, or by adjusting the mixing ratio of the zirconium compound and the monoolefin or olefin polymer and the polymer having a hydroxyl group or carboxyl group. The coating may be carried out by adjusting the amount applied to the aluminum base material. In this case, the coating amount, that is, the mixed coating amount, is preferably about 5000 mg/m ² or less from the viewpoint of film thickness, etc., and preferably about 300 mg/m ² or less. Of course, the above-mentioned mixed film 3 may be formed by forming the aluminum base material 1 into the container body 2 and then applying a treatment liquid to the inner surface of the container body 2 and drying it. It is better to form a container by forming a material whose surface is coated with the mixed film 3 in advance so that the mixed film surface is on the inner surface of the container, since the effect of improving moldability due to the mixed film surface can also be exhibited, and the moldability can be improved. This is preferable in that no lubricating oil is required. The container of the illustrated embodiment was also manufactured in this manner. In the illustrated embodiment, a container is shown in which the mixed coating 3 is formed only on the inner surface of the container body 2, but
If necessary, a mixed coating may be formed on the inner and outer surfaces of the container body 2. Effects of the invention As described above, the heat-resistant aluminum container for food and beverages according to the invention contains a zirconium compound, a monoolefin or an olefin polymer, and a polymer having a hydroxyl group or a carboxyl group at least on the inner surface of the container body made of an aluminum base material. The combined mixed coating is formed in a state in which the amount of zirconium deposited is specified to be 30 mg/m ² or more. Therefore, due to the presence of the mixed film, as will be clear from the examples described below, it can be made to have excellent heat resistance, and even when the container is heated, the film will not change color or emit smoke. There is no possibility that this will occur. Moreover, it has excellent corrosion resistance, and even when foods and the like are stored for a long period of time, corrosion of the container by the contents of the container can be prevented. Furthermore, it has excellent slip properties, and even when containers are stored in a stacked state, each container can be separated and taken out reliably and easily, making it extremely convenient to handle. . Furthermore, by using an aluminum material with a mixed film pre-coated on the surface of an aluminum base material and molding it into a container, it is possible to improve moldability and eliminate the need for lubricating oil during molding. This also has the effect of improving molding workability. Example Next, an example of this invention will be shown in comparison with a comparative example. [Example 1] A stock solution was prepared by mixing a mixture of 13% ZrO ₂ and 87% water with a 13% aqueous solution of a material consisting of 80 parts of ethylene and 20 parts of polyacrylic acid.
A treatment solution diluted to 10V/V (%) was prepared. Then, the treatment liquid was applied to the surface of a 0.15 mm thick aluminum base material made of JIS1200 alloy using a rubber roll, and then dried at 200°C for 10 seconds to produce a test material. The amount of zirconium deposited at this time was 30 mg/m ² . [Example 2] A test material was produced under the same conditions as in Example 1 except that the amount of zirconium deposited was set to 70 mg/m ² . [Comparative Example 1] A test material (without film treatment) consisting of a rolled aluminum base material having the same composition and the same shape as above was obtained. [Comparative Example 2] Vinyl chloride-vinyl acetate paint was applied to the same aluminum base material surface as above, and then heated at 150°C x 5
Drying was performed for seconds to produce a test material coated with a resin film with a film amount of 2 g/m ² . The following tests were conducted on the four types of test materials obtained above. [Corrosion Resistance Test] The four types of test materials were subjected to salt water spraying in accordance with JIS Z2371 for 150 hours, and the state of surface corrosion was investigated. The results are: ○: No corrosion was observed, △: Slight corrosion was observed.
×: Shown in Table 1 as severe corrosion. In addition, each sample material was immersed in hot water of 95℃ or higher for 30 minutes.
The state of discoloration of the surface was examined when immersed for a minute. The results are ○: No discoloration was observed, △:
Table 1 shows those in which slight discoloration was observed, and ×: severe discoloration. [Formability Test] Each sample material was press-molded into a container with a diameter of 12 cm and a depth of 3.5 mm, and the roughness of the aluminum on the inner peripheral surface of the molded product was examined. The results are shown in Table 1 as ○: No rough skin was observed, ×: rough skin was observed. [Slip property test] The slip property of the surface of each sample material was examined using an adhesion slip tester. The results are shown in Table 1 as ○: Good slip property, ×: Poor slip property. [Heating Test] Each sample material was directly heated with a gas burner to examine the state of discoloration on the surface of the material. The results are shown in Table 1 as ○: No discoloration was observed, ×: Discoloration from brown to black. At the same time, the presence or absence of smoke was also examined. The results are shown in Table 1 as ○: No smoke generation was observed, ×: Smoke generation was observed.

[Table] As is clear from the above results, the container according to this invention has excellent corrosion resistance and slip properties, and has excellent corrosion resistance without the risk of discoloration of the film or smoke generation even when heated. I was able to confirm it. It can also be seen that when a material in which a mixed film is previously formed on an aluminum base material is molded into a container, it has excellent moldability.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of a heat-resistant aluminum container for food and beverages according to this invention, and FIG. 2 is a perspective view of the appearance of the container. 1... Aluminum base material, 2... Container body, 3
...Mixed film, 4...Container.

Claims (1)

[Scope of utility model registration request] A mixed coating of a zirconium compound, a mono-olefin or an olefin polymer, and a polymer having a hydroxyl group or a carboxyl group is applied to at least the inner surface of the container body made of an aluminum base material, and the amount of zirconium deposited is specified to be 30 mg/m ² or more. 1. A heat-resistant aluminum container for food and beverages, characterized by being coated with.