JPS5820355Y2 - aluminum foil composite - Google Patents

Description

[Detailed description of the invention] The invention relates to an aluminum foil composite material, and more specifically, a linear copolymerized polyester resin layer is interposed on the back side of an aluminum foil laminated with printed aluminum foil, paper, or plastic film. This aluminum foil has good heat-sealing properties and is made by laminating resin layers made of chlorinated isotactic polypropylene resin and epoxy resin.

Conventionally, aluminum foil coated with a heat sealant has been widely used for packaging materials, lidding materials, and the like.

Namely, (1) A package for medicine that is generally made of a molded polyvinyl chloride sheet as a base, covered with coated aluminum foil, and sealed by heat sealing.

(FTP packaging) (2) Fill a solid or pasty food such as jam, butter, or chocolate into a molded container made of polyvinyl chloride, heat-resistant vinyl chloride resin, polystyrene, etc., heat-seal it with coated aluminum foil, and seal it with a lid. What I did.

(Blister Pack) (3) A paper cup or foamed polystyrene cup whose inner surface is coated with polyethylene is filled with ramen noodles, shiruko, etc., and is heat-sealed with coated aluminum foil to form a lid.

(4) A lactic acid drink such as sour or yogurt placed in a molded polystyrene cup and covered with aluminum foil.

In most cases, a molded container made of polyvinyl chloride or polystyrene is filled with aluminum foil coated with a heat-sealing agent and then heat-sealed as a lid material.

Instead of the polyvinyl chloride or polystyrene base material mentioned above, if you use polypropylene resin, which has characteristics such as low moisture permeability, heat resistance, and stiffness, and combine it with an aluminum foil lid, The above-mentioned PTP packaging and B115
Although it is thought that it can be used satisfactorily for applications such as ter packs, the combination of a polypropylene formal container and an aluminum foil lid has not been used until now because polypropylene has good heat sealability and does not deteriorate over time.
This is because an aluminum foil composite material with a structure excellent in heat resistance and steam resistance has not been found.

Some research has been done on lids for polypropylene containers and aluminum foil-formed containers (inner surface laminated with polypropylene film), but this also requires (1) Removing the contents. I can't open the lid by hand.

(2) Cost is high.

(3) Heat sealing temperature is high because polypropylene is fused together.

These problems have been pointed out as drawbacks, and the current situation is that it has not yet been put into practical use.

From the above, for molded containers using a polypropylene film or sheet molded door and a composite material whose heat-sealing surface is polypropylene, we found that: ■ Good heat-sealability; ■ Heat-sealability over time in various atmospheres. There is a demand for an aluminum foil with properties such as: ■ no loss of strength; ■ heat resistance, water resistance, and steam resistance; and ■ no blocking when wound into a coil. The inventor came up with the present invention as a result of intensive research on this subject.

That is, the present invention is an aluminum foil composite material with good heat-sealability for polypropylene molded containers.As illustrated in the drawings, the back side of aluminum foil 2 is pasted with aluminum foil, paper, or plastic film with printing 1 applied thereto. A resin layer 4 made of a chlorinated isotactic polypropylene resin and an epoxy resin is laminated thereon via a linear copolymerized polyester resin layer 3.

To describe the present invention in more detail, the present invention uses a mixed resin of chlorinated isotactic polypropylene resin and epoxy resin as a resin that adheres well to polypropylene containers, and this chlorinated isotactic polypropylene resin A linear copolymerized polyester resin is interposed to achieve adhesion between the resin layer made of epoxy resin and the aluminum foil.

Chlorinated isotactic polypropylene resin is obtained by chlorinating ordinary crystalline isotactic polypropylene, and the chlorine content is preferably within the range of 10 to 45%, and if it is less than 10%, it will not dissolve in organic solvents. Not only will the properties deteriorate and stability as a solution cannot be obtained, but
A uniform coating film cannot be obtained, and if it exceeds 45%, the adhesion to polypropylene decreases, and as a result, the heat sealing strength decreases, making it impossible to replace the aluminum foil composite material preferred for polypropylene containers.

Furthermore, it is preferable to add an epoxy resin to this chlorinated isotactic polypropylene in order to increase the cohesive force of the chlorinated isotactic polypropylene resin layer and prevent the heat seal strength from decreasing over time. In terms of compatibility, 70-95% of chlorinated isotactic polypropylene and 5-30% of epoxy resin
is appropriate.

In addition, when bonding aluminum foil and chlorinated isotactic polypropylene, it goes without saying that the resin has adhesive properties to both, but since chlorinated isotactic polypropylene has crystallinity, heat Even after being melted and cooled by sealing, crystallization tends to progress gradually if left in an atmosphere of 20 to 60°C, so chlorinated isotactic polypropylene A linear copolymer polyester resin with low crystallinity is suitable as a resin that does not reduce the adhesion at the interface.

In addition, the aluminum foil is not particularly limited and may be printed or laminated with paper or plastic film.The aluminum foil-linear copolymerized polyester resin layer obtained in this way may be used. - An aluminum foil composite material in which a resin layer consisting of a chlorinated isotactic polypropylene resin and an epoxy resin is laminated has good heat sealability with polypropylene when used as a lid material for a polypropylene molded container.

(2) There is no decrease in heat sealing strength in various atmospheres.

(3) Good water resistance.

(4) It can withstand hot packs and has good heat resistance and steam resistance.

(5) No blocking.

It can demonstrate excellent performance.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the aluminum foil composite material according to the present invention. 2... Aluminum foil, 3... Linear copolymerized polyester resin layer, 4... Resin layer made of chlorinated isotactic polypropylene resin and epoxy resin.

Claims (1)

[Scope of utility model registration request] An aluminum foil composite material with good heat sealability, which is made by laminating a resin layer made of chlorinated isotactic polypropylene resin and epoxy resin on the back side of aluminum foil via a linear copolymerized polyester resin layer.