JP3135113B2 - Package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package having a molded body filled with the contents and sealed with a lid, and to a package having little or no warpage of a flange portion of the package. is there. Incidentally, the film referred to in the present invention is used as a general term including a thick sheet.

[0002]

2. Description of the Related Art In packaging of foods, pharmaceuticals and the like, multi-layered films are often used in order to satisfy various required performances. For example, in the case of a package consisting of a molded main body and a lid, several types of unstretched films may be laminated on the main body side in order to impart properties such as gas barrier properties and pinhole resistance, or a combination of these may be used simultaneously. Extruded multilayer films are used. On the other hand, a laminated product of several types of stretched films and unstretched films is generally widely used for attaching and printing on the lid side. Next, as for the thickness of the main body and the lid, the thickness of the main body side is generally thicker because molding is performed, and the thickness in the thickness range belonging to the sheet category in the JIS classification may be used.

[0003] Needless to say, different types of resins, in general, even if the same type of resin is stretched and not stretched, physical properties are different, and thermal expansion coefficient and shrinkage behavior are different. Then, the sealed flange portion is warped. This gives a very negative image in terms of the appearance of the product. When displaying with the side filled with contents up, for example, overlapping packaging of sliced ham corresponds to this form, but when curled to the main body side, not only the appearance of the product is bad, but also the product printed on the back of the square flange Characters such as names are difficult to see. For this reason, the present inventor, by the combination of the combination of the body and the lid constituting the package,
Various investigations have been conducted to determine whether the above-mentioned warping phenomenon cannot be avoided at a relatively low price within the range of the existing multi-layering technology, and arrived at the package of the present invention.

[0004]

SUMMARY OF THE INVENTION A thermoformed main body container such as vacuum forming, pressure forming or vacuum / pressure forming is filled with the contents and sealed with a lid to keep the container air-filled. In a package such as a gas replacement package that seals by performing gas replacement or gas flush with an active gas, or a vacuum package that seals by vacuuming the inside, without sacrificing other characteristics such as storage stability, Provided is a package that solves the problem of warpage generated in a flange portion when heat sealing is performed due to a difference in the configuration of a multilayer film constituting a lid or the like.

[0005]

[MEANS FOR SOLVING THE PROBLEMS] When the total thickness of the main body and the lid is not more than 300 μm, the molded body and the lid are formed.
In a stacked package of a sliced ham , the main body is composed of a surface layer, an intermediate layer and a sealing layer, the lid is composed of a surface layer, an intermediate layer and a sealing layer, and the surface layers of the main body and the lid are saturated polyester, polycarbonate, or It is either a mixture of saturated polyesters and polycarbonates, body及
The intermediate layer of the cover and the cover
It consists of both a rear layer and a pinhole-resistant layer, and the thickness ratio of each surface layer is 10 % or more of the thickness of each main body and the lid, and the flange of the main body and the lid is sealed.
Slice ham with a warpage of plus or minus 5mm or less
A stacked package, wherein the barrier layer is any of ethylene vinyl alcohol copolymer or polyvinylidene chloride, the pinhole-resistant layer is any of polyamide, polyurethane, polyvinyl chloride, polybutene or polybutadiene; Is a mixture of an ethylene-based copolymer containing 3% by weight or more of polypropylene and polyethylene, and in a flange portion sealed between the seal layers of the main body and the lid, from the outside of the main body, a surface layer of the main body is formed. ,
This is a stacked package of sliced hams composed of an intermediate layer, a seal layer, a seal layer of a lid, an intermediate layer, and a surface layer in this order.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The saturated polyester constituting the surface layer of the main body and the lid used in the present invention refers to a linear thermoplastic resin having an ester bond in the main chain, such as polyethylene terephthalate and polybutylene terephthalate. And poly-1,4-cyclohexylene dimethylene terephthalate, polyarylate (polycondensate of bisphenol A and phthalic acids), poly-p-oxybenzoyl, and copolymers thereof. Further, polycarbonate generally refers to a thermoplastic resin having an aromatic polycarbonate bond. Further, a mixture of these saturated polyesters and polycarbonates may be used for both surface layers.

The ratio of the thickness of the surface layer to the body and the lid is preferably as high as 10% or more.
It is necessary . If the thickness ratio is less than 10 %, the effect of preventing curling may not be sufficient.

[0008] In the production of the multilayer film, a conventional method which has hitherto been known can be used. For example, the entire body may be formed as a co-extruded film at one time, or a surface layer may be applied to the intermediate layer of the co-extruded film by extruding a layer including the intermediate layer and the seal layer by a method such as extrusion lamination or dry lamination. You can also. There is no problem even if the material used for the surface layer is used on the laminating surface side of the intermediate layer in order to improve the suitability for lamination. Further, the whole can be made by laminating each single film. The same applies to the lid.

[0009] In addition, the package of the present invention is formed by vacuum forming, pressure forming or vacuum / pressure forming of a film to further improve the appearance of the package. May be printed. For example, as an example, (back) printing is performed on the lid, and the identification function of collective display of the product name and contents is added, and wood grain pattern, cloud dragon pattern, logo, etc. are printed on the main body side to make the product flourish You can also elaborate the design. As will be described in detail in the next intermediate layer, gas barrier properties may be imparted to either surface of the surface layer by coating or the like.

[0010] The intermediate layer of the main body and the lid used in the present invention is provided for protection and maintenance of the contents. The function of protection / maintenance specifically refers to imparting gas barrier properties and pinhole resistance. Depending on the purpose of protection / maintenance, gas barrier properties and / or pinhole resistance are imparted. To impart gas barrier properties, resins such as ethylene vinyl acetate and polyvinylidene chloride can be used. In the case of a lid, a film coated with these resins can be used as a surface layer or an intermediate layer. Further, since no molding is performed on the lid, a material obtained by depositing or coating a metal such as aluminum or tin or an inorganic substance such as silica with a thickness of 10 μm or less may be used as the surface layer or the intermediate layer of the lid. Next, in order to impart pinhole resistance, polyamide resin, polyurethane resin, polyvinyl chloride resin,
It becomes possible by using a polybutene resin or a polybutadiene resin.

The seal layer used in the present invention is provided primarily for the purpose of hermetically sealing the contents, and a resin generally used as a seal layer can be used. Ethylene-based copolymers such as coalesced or ethylene-methacrylic acid copolymers and metal cross-linked products thereof, or sealants such as polypropylene,
Sealants such as ethylene vinyl acetate and saturated polyester are preferred in terms of sealing properties. For the seal layer on the main body side, a resin generally used as a seal layer can be used.For example, polyethylene, an ethylene copolymer such as an ethylene vinyl acetate copolymer or an ethylene methacrylic acid copolymer and a metal crosslinked product thereof, Polypropylene is preferred.
Further, an easily peelable delamination type or delamination type sealant can be used, and a delamination type or delamination type sealant such as a mixture of an ethylene-based copolymer containing 3% by weight or more of polypropylene and polyethylene can be used. Is preferred. If the polypropylene is less than 3% by weight,
The effect of the easy opening property is reduced.

[0012] The package of the present invention is a wrapped sliced ham.
A flange that is used for the body and seals the body and lid
It is necessary that the warpage of the part is plus or minus 5 mm or less
It is. For the warpage of the flange, the main body has a diameter of 100 mmΦ,
Formed to a depth of 14mm, into which diameter 98mmΦ, thickness 2
7 mm sliced ham and put a vacuum inside the package.
Then, make a package heat-sealed with a lid,
Cut out 150mm square so that it comes to the center, and warp four squares
Height from the surface assuming that the lid is horizontal
It is the average value measured with the warpage to the side as a plus. this
Almost no curl if the average value is less than ± 5mm
You can judge that there is no. As a configuration of the package, in the flange portion sealed between the seal layer of the main body and the lid,
From the outside of the main body, it is more preferable that the surface layer, the intermediate layer, the sealing layer, the sealing layer of the lid, the intermediate layer, and the surface layer of the main body are arranged in this order from the viewpoint of function, cost, and the like.

[0013]

EXAMPLE A main body and a lid film having the surface layers shown in Table 1 were prepared by the method described below, and the degree of warpage of the flange was examined by the following method. The method is to form a body with a diameter of 100 mmΦ and a depth of 14 mm, put seven sliced hams with a diameter of 98 mmΦ and a thickness of 2 mm into this, and create a package heat-sealed with a lid while vacuuming the inside of the package. Cut out the 150mm square so that the molded part comes to the center, measure the height of the four corners warping from the surface to the body side as a plus, assuming that the lid is horizontal,
The average values were compared. Generally, if this average value is less than plus or minus 5 mm, it can be determined that there is almost no curl.

In the first to fourth embodiments, the entire body is 150 μm.
The lid is made of a stretched printed polyester of 12 μm as the surface layer, 20 μm cellophane (K cello) coated with polyvinylidene chloride as the intermediate layer, and 30 μm ethylene vinyl acetate as the sealing layer. The polymer was dry laminated in this order. In the main body of Example 1, a polyester for molding (20 μm), an adhesive (10 μm) and an ethylene-vinyl alcohol copolymer (15
μm), and 6,66
Nylon copolymer (15 μm), adhesive (10 μm) and linear low density polyethylene (80 μm) as seal layer
In the configuration, "Koda PETG6763" manufactured by Eastman Co. was used as the polyester of the surface layer. In the main bodies of Examples 2 to 4, the surface layer resin of Example 1 was changed, and as Example 2, polybutylene terephthalate (“Schuranex 600FP” manufactured by Polyplastics Co., Ltd.) was used. As Example 3, polycarbonate (Sumitomo Dow) was used. "Calibur 200-13" manufactured by K.K.
A mixture of 15 parts by weight of "Lexan SP1310" manufactured by E Company and 85 parts by weight of a saturated polyester ("Kurapet KL541R" manufactured by Kuraray Co., Ltd.) was used. In each case, there was almost no warpage at ± 5 mm or less.

In Examples 5 and 6, the main body of Example 1 was used for the main body, and the lids were respectively formed by the following methods. That is, the lid of Example 5 was made of a polyethylene terephthalate film (16 μm) as a surface layer, a biaxially stretched nylon film (12 μm) coated with polyvinylidene chloride as an intermediate layer for providing a pinhole layer and barrier properties, and an ethylene sealant layer. Methacrylic acid copolymer metal crosslinked product (30μ
m), a dry-laminated configuration was prepared. The lid of Example 6 was composed of a polyethylene terephthalate film (12 μm) as a surface layer, an adhesive (5 μm), a polyvinylidene chloride (15 μm) having a gas barrier property as an intermediate layer, an adhesive (5 μm), and a seal layer. Coextruded in the order of a certain low-density polyethylene (30 μm) was formed by thermal lamination.

As Embodiments 7 and 8, in the main body of Embodiment 1, the main body of Embodiment 7 is a pinhole-resistant layer 6,66.
The copolymer of nylon (15 μm) and the ethylene-vinyl alcohol copolymer (15 μm) of the gas barrier layer were removed from the main body of Example 8, and the thickness of the linear low-density polyethylene of the seal layer was 85 μm. Thickness 1
It was 40 μm. The lid of the seventh embodiment is the same as the lid of the first embodiment,
The lid of Example 8 was tested in combination with the lid of Example 5. Curling was hardly observed in these cases.

In Examples 9 and 10, 120 μm co-extrusion was performed by thermal lamination on the printed surface of a 16 μm molding polyester film (“F865” manufactured by Toray Industries, Inc.) on which a cloud pattern was printed as the surface layer of the main body. The film was prepared by thermocompression bonding. The main body of Example 9 was formed from the laminating surface side from the polyester for molding (20 μm), the adhesive (10 μm), and the ethylene-vinyl alcohol copolymer (1) used in Example 1.
5 μm), the composition of 6,66 copolymer nylon (15 μm), the adhesive (10 μm) and the sealing layer (50 μm).
0 μm), ethylene vinyl alcohol copolymer (20 μm)
m), adhesive (10 μm), nylon 6,66 copolymer (15 μm), adhesive (10 μm) and seal layer (55 μm)
μm), and the seal layer was a mixture of 70% by weight of an ethylene methacrylic acid copolymer metal crosslinked product and 30% by weight of an ethylene propylene random copolymer having an ethylene content of 5%. The lid was made of 12 μm stretched polyester as in Example 1.
50μ which reduced the whole thickness of the main body used in
m was extruded and dry-laminated. In each case, there was almost no warpage at ± 5 mm or less, and the easy-opening property at the time of opening was good while the sealing property was sufficiently maintained.

As Comparative Examples 1 and 2, the main body was nylon 6 (15 μm), adhesive (10 μm), ethylene vinyl alcohol copolymer (15 μm), adhesive (10 μm), ethylene vinyl acetate copolymer from the surface layer side. (70μ
m) A 120 μm coextruded film laminated in the order of was used and sealed with the lid of Example 1. In Comparative Example 2, the surface layer of the main body of Comparative Example 1 was made of polypropylene. Comparative Example 1,
In both cases, both curled greatly toward the main body.

As Comparative Example 3, the main body used in Example 5
A film obtained by dry laminating a 30 μm stretched polypropylene and a 20 μm cellophane (K cello) coated with polyvinylidene chloride from the surface layer side as a lid and a 40 μm ethylene methacrylic acid copolymer metal crosslinked product in this order as a seal layer is used. And sealed. The result was curl toward the lid. As Comparative Example 4, the thickness of the main body of Example 1 was changed from the thickness configuration of the main body of Example 1 to the molding polyester (5 μm), the adhesive (7 μm), the ethylene-vinyl alcohol copolymer (10 μm) as the intermediate gas barrier layer, and the intermediate layer. 6,66 copolymer nylon (10μ)
m), an adhesive (8 μm) and a linear low-density polyethylene (100 μm) as a sealing layer to a total thickness of 140 μm, and the lid of Example 1 was used. As Comparative Example 5,
The surface layer of Comparative Example 4 was the polycarbonate of Example 3 with the same thickness ratio, the lid was a surface layer of biaxially stretched polyester of 3 μm, the intermediate layer was polyvinylidene chloride coated 30 μm of polypropylene, and the seal layer was 50 μm. Were dry-laminated in this order. In Comparative Examples 4 and 5, the curls are slightly conspicuous. In particular, Comparative Example 5 has structural aspects, and the curl is larger than Comparative Example 4.

Table 1 summarizes the results of the above Examples and Comparative Examples.

[Table 1]

The abbreviations used in the table are as follows. PET: Polyethylene or its copolymer PBT: Polybutylene terephthalate PC: Polycarbonate Ny: Polyamide (nylon) PP: Polypropylene In calculating the thickness ratio of the surface layer, the thickness of the dry laminate adhesive is generally several μm. I ignored it because there was.

[0022]

The package according to the present invention has an excellent appearance with little or no warping in the sealed flange of the main body and the lid, which is a conventional defect, and has a conventional appearance. It is suitable as a package capable of industrially producing a multilayer film having various functions by the multilayering technology.

Claims (5)

(57) [Claims] 1. A consists of a molded body and a lid, the body
And slices whose total thickness of the lid is 300 μm or less
In the stacked ham package, the main body is composed of a surface layer, an intermediate layer and a seal layer, the lid is composed of a surface layer, an intermediate layer and a seal layer, and the surface layers of the main body and the lid are made of saturated polyester, polycarbonate or saturated polyester. And a mixture of polycarbonate, and the intermediate layer of the main body and the lid is
Barrier layer or pinhole resistant layer or barrier layer and pin resistant
Consists both layers of the hole layer, the thickness ratio of the respective body of each surface layer is the ratio of 10% or more of the thickness of the lid body
The warpage of the flange where the lid and the lid are sealed
Sliced ham characterized by being less than 5 mm eggplant
Stacked package. 2. The stacked package of sliced ham according to claim 1, wherein the barrier layer is made of one of ethylene vinyl alcohol copolymer and polyvinylidene chloride. 3. The anti-pinhole layer according to claim 1, wherein the anti-pinhole layer is made of any one of polyamide, polyurethane, polyvinyl chloride, polybutene and polybutadiene.
A stacked package of the sliced ham described. 4. The stacked package of sliced ham according to claim 1, wherein the seal layer of the main body is a mixture of an ethylene-based copolymer containing 3% by weight or more of polypropylene and polyethylene. . 5. In a flange portion sealed between a sealing layer of a main body and a lid, a surface layer of the main body, an intermediate layer, a sealing layer, a sealing layer of the lid, an intermediate layer, and a surface layer are arranged in this order from outside the main body. The stacked package of sliced ham according to any one of claims 1 to 4, wherein