JPH06293370A - Cap for aerosol can - Google Patents

Abstract

PURPOSE:To provide a cap that is put on an aerosol can and is optimum for use in aerosol can that contains high corrosive injection agent such as dimethyl ether(DME), liquefied petroleum gas(LPG) or the like. CONSTITUTION:A cap for aerosol can is made of a laminated body that is made up by applying coating of fluorocarbon resin layer at least to one side of an aluminum plate and by drawing so that the resin layer comes to the inside. The caps made as mentioned above are optimum for use in aerosol cans containing various types of injection agent.

Description

Detailed Description of the Invention

[0001]

The present invention relates to dimethyl ether (D
(ME) or liquefied petroleum gas (LPG) as a propellant, and relates to a cap which is used by being fitted onto the upper portion of an aerosol can for spraying the contents in a mist or mousse form.

[0002]

2. Description of the Related Art Conventionally, as a propellant for aerosol cans, chlorofluorocarbon has conventionally been the mainstream. However, due to global environmental problems, the use of chlorofluorocarbon is regulated, and DME and LPG are used as alternative propellants. became. Normal,
The body of the aerosol can is made of a single metal, but depending on the propellant used, it is possible to coat the interior of the body of the aerosol can with a resin with excellent corrosion resistance, or to put a plastic bag inside. It is known that the cap fitted on the upper part of the mold is molded from a metal plate coated with a polypropylene film in order to improve the corrosion resistance (Japanese Utility Model Publication No. 55-76064).

However, since DME and LPG are extremely corrosive, the resin layer may be partly peeled off even when the cap coated with the polypropylene film is stored or used for a long time.

[0004]

DISCLOSURE OF THE INVENTION The present invention has found a cap capable of solving the above-mentioned problems, and its gist is to provide a laminate in which at least one surface of an aluminum plate is coated with a fluororesin layer, This is a cap for an aerosol can that is drawn so that the layer becomes the inner surface. The present invention will be described in detail below. As the aluminum plate used in the present invention, an alloy of aluminum and magnesium (5000 series according to JIS H0001) can be preferably used in terms of workability and strength. Further, the surface of the aluminum plate may be subjected to usual chromate treatment, chemical conversion treatment such as zirconium treatment or titanate treatment, or physical surface treatment such as electrolytic etching. A plate having a thickness of 0.2 to 0.7 mm, preferably 0.3 to 0.6 mm is suitably used.

The fluororesin used in the present invention includes polytetrafluoroethyl, a copolymer of tetrafluoroethylene and hexafluoropolypropylene, a copolymer of tetrafluoroethyl and perfluoroalkyl vinyl ether, and polychlorotrifluoroethylene. Examples thereof include, but are not limited to, polyvinylidene fluoride, polyvinyl fluoride, copolymers of ethylene and tetrafluoroethyl, copolymers of ethylene and chlorotrifluoroethylene, and the like. The thickness of the fluororesin layer is 20-
A range of 150 μm, preferably 30 to 100 μm can be suitably used.

The above-mentioned resin is coated on the surface of the aluminum plate, and the coating method may be a usual melt laminating method. The obtained laminated body needs to be drawn so that the resin layer becomes the inner surface of the cap. The drawing process may be performed by an ordinary cold working method depending on the shape of the cap. The cap of the present invention is to be fitted on the upper part of the aerosol can, and can also be used for the uppermost cap for attaching the injection valve and the shoulder part of the intermediate part with the main body.

The present invention will be described below with reference to examples.

[0008]

【Example】

Example 1 An aluminum plate whose surface has been chromated (A5052
A film (thickness: 25 μm) made of a copolymer of tetrafluoroethylene and hexafluoropolypropylene was melt-laminated on one surface (−O thickness 0.43 mm).

Using the obtained laminate, a cap having a final product shape was drawn by drawing so that the resin layer was on the inner surface. Next, a valve was attached to this cap, and then the cap was fitted onto the upper portion of the aerosol can body (40 mm diameter × 96 mm height, molded by the impact molding method and then spray-coated with polyamideimide paint on the inner surface). After filling the aerosol can with various contents, it was stored in an inverted state at an ambient temperature of 45 ° C. for 3 months, and the state of the inner surface of the cap was observed. As a result, no abnormality was found in the case where the propellant contained LPG hair treatment as the content, and no abnormality was found in the case where the propellant contained the acidic solution of PH2 of DME as the content.

Example 2 Example 1 except that the resin layer coating the surface of the aluminum plate was melt-laminated with a film (thickness: 25 μm) made of a copolymer of ethylene and tetrafluoroethylene.
A storage test was conducted in the same manner as in Example 1 after constructing an aerosol can with the same contents as described above. As a result, no abnormality was found in both the propellant containing LPG hair treatment and the propellant containing DME PH2 acidic liquid.

Comparative Example 1 An aerosol can was constructed in the same manner as in Example 1 except that the resin layer covering the surface of the aluminum plate was a polypropylene film (thickness: 20 μm), and then a storage test was conducted in the same manner as in Example 1. As a result, both the propellant containing LPG hair treatment and the propellant containing DME PH2 acidic liquid as contents contained swelling on almost the entire inner surface and the resin was peeled off.

Comparative Example 2 The same chromate-treated aluminum plate as in Example 1 was used to draw a cap in the same manner as in Example 1 and then spray coated with an epoxyphenol-based paint to obtain an inner surface having a thickness of 4 μm. Obtained. Using the obtained cap, a storage test was performed in the same manner as in Example 1. as a result,
For both the propellant containing LPG hair treatment and the propellant containing DME PH2 acidic liquid as contents, swelling was observed on almost the entire inner surface, and pitting corrosion on aluminum was observed along with resin peeling. Was done.

[0013]

As described above, the cap of the present invention has excellent corrosion resistance and can be suitably used for aerosol cans containing various propellants.

Claims (1)

[Claims] 1. A cap for an aerosol can obtained by drawing a laminate in which at least one surface of an aluminum plate is coated with a fluororesin layer so that the resin layer is the inner surface.