JP3796331B2 - Laminated film for food packaging - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated film for food packaging, and more specifically, a milk packaging film and a gray film, and optionally a laminated film for food packaging in which a film layer made of an ethylene-α-olefin copolymer is laminated. the film.
[0002]
[Prior art]
A laminated film for food packaging, particularly a laminated film for frozen food packaging, is usually required to have a light-shielding property in order to prevent deterioration of the oil used as the contents, particularly fried foods, and the consumer's purchasing desire. A certain degree of aesthetics is also required from the meaning of arousing.
[0003]
Conventionally, a film obtained by laminating a polyethylene terephthalate film or the like on a resin film such as polyethylene vapor-deposited with aluminum has been used to satisfy such demands, which satisfies light shielding properties and aesthetics.
However, in the production of resin films such as polyethylene deposited with aluminum, there is a problem that an expensive aluminum vacuum deposition apparatus is required and the production of the film is costly. It is not preferable from the viewpoint of hygiene to touch the surface, and in order to seal it, a film must be further laminated on the inside of the aluminum vapor-deposited film, leading to an increase in the cost of the product.
[0004]
[Problems to be solved by the invention]
The present invention has been made from the above viewpoint, and an object of the present invention is to provide a food packaging film excellent in light-shielding properties and aesthetics at low cost without using the above aluminum vapor deposition film.
[0005]
[Means for Solving the Problems]
As a result of extensive research, the present inventors have found that a milky white film containing a specific amount of a white pigment, a gray film containing specific amounts of a black pigment and a white pigment, and, if necessary, an ethylene-α-olefin. It has been found that the above object can be achieved by a laminated film for food packaging in which a film layer made of a copolymer is laminated. The present invention has been completed based on such findings.
[0006]
That is, this invention provides the following laminated films for food packaging.
(1) A milky white film having a white pigment content of 5 to 20% by weight and a thickness of 10 μm or more; a black pigment content of 0.2 to 1.0% by weight; and the black color In the laminated film for food packaging formed by laminating a white film containing a white pigment at a weight ratio of 20 to 60 with respect to the pigment 1 and having a thickness of 10 μm or more , the outer surface is a milky white film. A laminated film for packaging foods .
(2) A laminated film for food packaging in which a film layer made of an ethylene-α-olefin copolymer is laminated on the gray film side of the laminated film for food packaging described in (1) above.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described.
1. Contents of each film layer constituting the laminated film (1) Milky white film layer (1) The resin used is not particularly limited, but is a linear low density polyethylene (LLDPE) made of an ethylene-α-olefin copolymer, It is appropriately selected from thermoplastic resins such as high pressure method low density polyethylene (LDPE), medium density polyethylene, polypropylene, polyamide and polyester. Among these, an ethylene-α-olefin copolymer is preferably used because high strength can be obtained. In this case, as the α-olefin, butene-1, hexene, 4-methyl-1-pentene, isohexane, octene and the like are preferable.
[0008]
Moreover, you may mix | blend a heat stabilizer, a deodorizing agent, an antibacterial agent, an antiblocking agent, a slip agent, etc. with respect to the said thermoplastic resin as needed.
(2) The milky white film layer must contain a white pigment. The white pigment to be used is not particularly limited, and examples thereof include titanium dioxide, zinc oxide (zinc white), zinc sulfide, barium sulfate, and lead white. Among these, titanium dioxide is preferably used because of its fine particle size, excellent whiteness, hiding power, and coloring power, and excellent light resistance, heat resistance, and chemical resistance.
[0009]
The content of the white pigment is 5 to 30% by weight, preferably 10 to 15% by weight. If it is less than 5% by weight, the color of the outer surface becomes gray due to the influence of the black colored layer, the aesthetics deteriorate, and at the same time, the light shielding property also deteriorates and the contents may be oxidized. On the other hand, when it exceeds 30% by weight, the melt-kneading property of the resin is extremely lowered during the production of the film, and there is a possibility that color unevenness occurs.
[0010]
(3) The method for producing the milky white film is not particularly limited, and a known extrusion molding method such as an inflation molding method or a T-die molding may be used.
(2) Gray film layer (1) The resin used is not particularly limited, but is a linear low-density polyethylene (LLDPE) made of an ethylene-α-olefin copolymer, a high-pressure low-density polyethylene (LDPE), It is appropriately selected from thermoplastic resins such as density polyethylene, polypropylene, polyamide, and polyester. Among them, an ethylene-α-olefin copolymer is preferably used because high strength can be obtained. In this case, as the α-olefin, butene-1, hexene, 4-methyl-1-pentene, isohexane, octene and the like are preferable.
[0011]
Moreover, you may mix | blend a heat stabilizer, a deodorizing agent, an antibacterial agent, an antiblocking agent, a slip agent, etc. with respect to the said thermoplastic resin as needed.
(2) The gray film layer must contain a black pigment and a white pigment. The black pigment to be used is not particularly limited, and examples thereof include carbon black, iron black, graphite, etc. Among them, carbon black is preferably used because it has excellent hiding power and coloring power and is inexpensive. . Further, the particle size is not particularly limited, but when furnace carbon black is used, a particle size in the range of 0.03 to 0.04 μm is usually used.
[0012]
The content of the black pigment is 0.2 to 1.0% by weight, preferably 0.3 to 0.7% by weight. If it is less than 0.2% by weight, sufficient light shielding properties cannot be obtained, and the contents may be oxidized. If it exceeds 1.0% by weight, the color of the outer surface becomes gray and the aesthetics may deteriorate. Furthermore, it is necessary that the white pigment is contained in a weight ratio of 20 to 60, preferably 25 to 50 with respect to the black pigment 1. If it is less than 20, the color of the outer surface becomes gray and the aesthetics deteriorate, and if it exceeds 60, there may be a problem that the pigment cannot be mixed uniformly.
[0013]
(3) The production method of the gray film is not particularly limited, and a known extrusion method such as inflation molding or T-die molding may be used.
2. Laminated film for food packaging (1) In the case of a laminated film obtained by laminating the milky white film and the gray film (1) The total thickness of the laminated film for food packaging is 30 μm or more. preferable. When this thickness is less than 30 μm, the strength is insufficient and the film is easily broken. About an upper limit, what is necessary is just to select suitably according to the objective.
[0014]
(2) The thickness of the milky white film layer is 10 μm or more, preferably 15 μm or more. When the thickness of the milky white film layer is less than 10 μm, it may be inferior in aesthetics, and coextrusion may be difficult when forming a laminated film.
(3) The thickness of the gray film layer is 10 μm or more, preferably 15 μm or more. When the thickness of the milky white film layer is less than 10 μm, the light shielding property may be insufficient, and the coextrusion at the time of preparing the laminated film may be difficult.
[0015]
(4) The ratio between the thickness of the milky white film layer and the thickness of the gray film layer is not particularly limited. What is necessary is just to select suitably according to the objective.
(5) The lamination method of the milky white film and the gray film is not particularly limited, and is a known extrusion lamination, for example, an extrusion lamination in which a gray film resin is directly melt-extruded and bonded onto a milky white film substrate. Both economically and economically.
[0016]
(6) Furthermore, a resin layer made of polyamide, polyethylene terephthalate, or the like may be laminated on the outside of the milky white film. Printing may be performed on the back side of these resin layers, that is, the side in contact with the milky white film.
(2) When the film layer which consists of an ethylene-alpha-olefin copolymer is laminated | stacked on the gray type film side in the laminated film for food packaging as described in said (1).
[0017]
(1) The film layer made of the ethylene-α-olefin copolymer is laminated for the purpose of further improving the sealing property and ensuring the safety to foods to be contacted. It is necessary to be laminated on the gray film side of the film.
(2) The ethylene-α-olefin copolymer is not particularly limited, but it has a density of 0.860 to 0.935, an MI (melt index) of 0.5 to 7.0, and is a comonomer α. -Examples of olefins include butene-1, hexene, 4-methyl-1-pentene, isohexane, octene and the like.
[0018]
(3) The method for laminating the laminated film for food packaging described in (1) above and the ethylene-α-olefin copolymer resin film is not particularly limited, and may be a known extrusion lamination, for example, as described in (1) above. An extrusion laminate in which the linear low-density polyethylene resin film is directly melt-extruded and bonded onto a laminated film base material for food packaging is preferable in terms of both process and cost.
[0019]
(4) Furthermore, a resin layer made of polyamide, polyethylene terephthalate or the like may be laminated on the outside of the milky white film. Printing may be performed on the back side of these resin layers, that is, the side in contact with the milky white film.
[0020]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
〔Example〕
(1) Preparation of milky white film Slip to 79.2 grams of ethylene-α-olefin copolymer (Mortec 0138N, manufactured by Idemitsu Petrochemical Co., Ltd.) (ethylene-α-olefin copolymer in which α-olefin is 1-octene) Agent (Idemitsu Petrochemical's EB43) 0.1 gram and anti-blocking agent 0.2 gram dissolved in 8.6 gram of low-density polyethylene was added to make a resin component. Added 9 grams. This was subjected to inflation molding to obtain a milky white film having a thickness of 16 μm.
(2) Preparation of gray film Ethylene-α-olefin copolymer (Madetec 0138N made by Idemitsu Petrochemical Co., Ltd.) (Same as above) A resin component was prepared by dissolving 0.2 grams in 12.5 grams of low density polyethylene, and 11.3 grams of titanium dioxide as a white pigment and 0.4 grams of furnace carbon black as a black pigment were added thereto. . This was blown to obtain a gray film having a thickness of 16 μm.
(3) Preparation of seal layer film Ethylene-α-olefin copolymer (Idemitsu Petrochemical's MORETECH 0138N) (same as above) 99.0 grams, slip agent (Idemitsu Petrochemical's EB43) 0.1 grams and anti-blocking A solution obtained by dissolving 0.2 gram of the agent in 0.7 gram of low density polyethylene was added, and this was subjected to inflation molding to obtain a film for a sealing layer having a thickness of 8 μm.
(4) Preparation of laminated film for food packaging Each film obtained in the above (1) to (3) was coextruded to obtain a laminated film in which a milky white film, a gray film, and a seal layer film were laminated in this order. .
The thickness of the laminated film was 40 μm.
[0021]
As a food packaging film, it had excellent appearance and extremely good light shielding properties.
[0022]
【The invention's effect】
In this invention, the film for food packaging excellent in light-shielding property and aesthetics could be provided at low cost.

Claims (2)

A milky white film having a white pigment content of 5 to 20% by weight and a thickness of 10 μm or more; a black pigment content of 0.2 to 1.0% by weight; On the other hand, in a laminated film for food packaging formed by laminating a gray film having a thickness of 10 μm or more, containing a white pigment at a weight ratio of 20 to 60 ,
A laminated film for food packaging, characterized in that the outer surface is a milky white film . The laminated film for food packaging which laminated | stacked the film layer which consists of an ethylene-alpha-olefin copolymer on the gray-type film side in the laminated film for food packaging of Claim 1.