JP2000006331A - Wrap film for packaging food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject wrap film excellent in self-adhesiveness, transparency, cutting properties, low smell properties, heat resistance and safety. SOLUTION: A wrap film for packaging food is obtained by laminating a polyolefin resin layer compounded with 0.5-15 wt.% of one of an alicyclic saturated hydrocarbon resin and a terpene resin or a combination of them and 0.3-8.0 wt.% of an antifogging agent on the single surface or both surfaces of an amorphous resin layer compounded with 0-10 wt.% of one of an alicyclic saturated hydrocarbon resin and a terpene resin or a combination of them by co-extrusion. This film is excellent in self-adhesiveness, transparency, cutting properties, low smell properties, heat resistance and safety.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a co-extruded laminated food packaging wrap film comprising at least two layers.
More specifically, the present invention relates to a wrap film for food packaging having excellent self-adhesiveness, transparency, cutting properties, low odor, heat resistance and safety.

[0002]

2. Description of the Related Art A wrap film for food packaging is used for wrapping fresh foods or frozen foods directly or in a container such as tableware, and is used for preserving foods in a refrigerator or cooking by heating in a microwave oven. I have. It is an object of the present invention to obtain the effects of keeping the freshness of the food, preventing the reduction of the aroma, preventing dust, preventing the scattering and leakage, and preventing the transfer of the odor by wrapping the food in a film of this kind.

Generally, this kind of film is used in a state where it is stored in a storage box provided with a saw blade-shaped metal, paper or plastic cutting blade, and the film is pulled out by hand and an appropriate amount is cut with the cutting blade. .

[0004] Wrap films provided for such food packaging include self-adhesiveness, freshness retention due to appropriate gas permeability, anti-fogging properties, transparency, flexibility, heat resistance, and low odor of the film itself. It is required that the cutability of the storage box with the cutting blade is good.

Until now, food packaging wrap films include biaxially stretched polyvinylidene chloride resin films, polyvinyl chloride films, polyethylene films, polymethylpentene films, and laminated films of polyethylene, polypropylene, and polymethylpentene films. It is known that at least two or more resin layers such as methylpentene, polyamide, polyvinyl acetate, polyethylene terephthalate, and polycarbonate are combined.

[0006]

However, in a conventional food packaging wrap film, for example, a biaxially stretched polyvinylidene chloride-based resin film (for example, Japanese Patent Publication No. 38-4174) draws the film and cuts it. When the film is cut with a film, the film has a very low tear strength, so that the film has good cuttability. However, the film is easily torn in a direction other than the cutting blade and the handleability is poor. Further, since there is no appropriate gas permeability, when such a wrap film is used for preserving fresh food such as vegetables, a freshness maintaining effect cannot be expected.

[0007] Polyvinyl chloride films and polyethylene films (for example, JP-A-6-179787 and JP-B-59-23268) have low heat resistance when used for cooking in a microwave oven, and thus the films are not melted. And may be difficult to peel off from food or tableware.

[0008] Polymethylpentene-based films (for example,
Japanese Unexamined Patent Publication No. Hei 5-342115) has a high tear strength, and the film has poor cuttability, and has insufficient flexibility, so that it has poor wrapping properties for foods and dishes.

For the purpose of solving the problems of the above-mentioned polyvinylidene chloride resin film, polyvinyl chloride film, and polyethylene film, films devised by combining resin layers of polyethylene, polypropylene, polymethylpentene, polyamide, and the like, For example, Japanese Patent Application Hei 4-
297392 and Japanese Patent Application No. 7-232488) have low adhesiveness and poor film cutability.

A combination of resin layers of polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, etc.
No. 62, JP-A-6-238848) has been proposed as a wrap film having excellent adhesiveness, cutability and heat resistance. However, a film was obtained by co-extrusion lamination of polypropylene and polyethylene terephthalate or a polycarbonate resin layer. In this case, there is a disadvantage that peeling easily occurs between the resin layers. For this reason, when peeling between the resin layers occurs when the film is drawn out by hand and cut with a cutting blade, there is a problem that a tearing phenomenon of the film occurs and good cutability cannot be obtained. In order to prevent this problem, there has been proposed a method of improving the adhesive strength between the resin layers by providing an adhesive layer between the respective resin layers at the time of co-extrusion lamination. However, when the number of resin layers is increased, the cost of the co-extrusion apparatus and the resin composition is increased. Has the problem of becoming high.

The present invention has been made in view of such circumstances, and requires self-adhesiveness, appropriate gas permeability, and freshness retention by a wrap film provided for food packaging.
An object of the present invention is to provide an excellent food packaging wrap film which satisfies antifogging property, transparency, flexibility, heat resistance, low odor of the film itself, and good cutability with a cutting blade of a storage box.

[0012]

The inventors of the present invention have conducted intensive studies to satisfy the above-mentioned characteristics, and as a result, the alicyclic saturated hydrocarbon resin and the terpene resin alone or in combination of two types have been used in an amount of from 0 to 10%. A single or a combination of two types of alicyclic saturated hydrocarbon resin and terpene resin is provided on one or both surfaces of the amorphous resin layer (a) containing 0.5% to 15% by weight.
The present invention has been completed by finding that an excellent food packaging film can be obtained by co-extruding and laminating a polyolefin resin layer (b) containing 0.3% to 8.0% by weight of an antifogging agent. Reached.

Here, examples of the resin of the amorphous resin layer (a) include a polycarbonate resin, a methacrylic resin layer and a polyethylene terephthalate resin. The amorphous resin layer (a) is a resin layer in an amorphous state, in which the resin is non-crystalline or the resin is rapidly cooled from a molten state to be in an amorphous state. is there.

As the resin of the polyolefin resin layer (b), low-density polyethylene resin, butene-1, hexene-
Linear low-density polyethylene resin obtained by copolymerizing ethylene with an α-olefin such as 1,4-methylpentene-1 and octene-1, a compound having a structure in which a transition metal is sandwiched between π-electron unsaturated cyclic compounds Linear low-density polyethylene resin obtained by copolymerizing α-olefin and ethylene with a metallocene catalyst consisting of, propylene resin, and polypropylene-based resin obtained by copolymerizing α-olefin and propylene, and these may be used alone or in combination of two or more. It can be used in combination.

Examples of the antifogging agent to be blended in the polyolefin resin layer (b) include monoglycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, and polyoxyethylene alkyl ether.
This is used alone or in combination of two or more. These anti-fog agents are available from Riken Vitamin Co., Ltd.
-100, DO-100, O71-DE, L-250
It is commercially available under trade names such as A and B-205. The addition amount of the antifogging agent is set to 0.3 to 8.0% by weight based on the polyolefin resin layer (b), and is appropriately adjusted according to a film forming method, a film thickness, a type of food to be packaged, a packaging form, and the like.

The alicyclic hydrocarbon resin in the present invention is a resin obtained by hydrogenating an aromatic petroleum resin and is commercially available from Arakawa Chemical Co., Ltd. under the trade name of "Alcon". . Further, terpene resins are those obtained by polymerizing terpene monomers such as β-pinene, dipentene, α-pinene, d-limonene, and aromatic monomers such as styrene, α-methylstyrene, vinyltoluene and terpene. Aromatically modified terpene resins copolymerized with monomers, or terpene phenolic resins obtained by copolymerizing phenols such as phenol, cresol and bisphenol A with terpene monomers, and these terpene resins It may be a hydrogenated terpene resin obtained by hydrogenation. These terpene resins are commercially available from Yashara Chemical Corporation under the trade names "CLEARON" and "YS Resin". The compounding amount of the alicyclic saturated hydrocarbon resin and the terpene resin is 0 with respect to the amorphous resin layer (a).
10 to 10% by weight, and 0.5 to 15% by weight based on the polyolefin resin layer (b).

By blending an alicyclic saturated hydrocarbon resin and a terpene resin, when the film is drawn out by hand and cut with a cutting blade, the resin layer between the amorphous resin layer (a) and the polyolefin resin layer (b) Peeling of the film is prevented, the film tearing phenomenon is prevented, and good cut properties are obtained.

Further, the synergistic effect with the antifogging agent blended in the polyolefin resin layer (b) makes it possible to achieve both good self-adhesiveness and film drawability. In order to obtain these properties, the polyolefin resin layer (b) may contain 0.5 to 5.0% by weight of an antifogging agent, an alicyclic saturated hydrocarbon resin and a terpene resin alone or in combination of two kinds.
It is desirable to set it to 15% by weight. When the amount of the antifogging agent is less than 0.8% by weight, the self-adhesiveness and the film drawing property are poor. On the other hand, when the amount exceeds 5.0% by weight, the excessive amount of the antifogging agent migrates to the film surface, resulting in a transparent film. It is not preferable because of reduced properties, unpleasant stickiness and smell of antifogging agent. If the content of the alicyclic saturated hydrocarbon resin and the terpene resin is less than 0.5% by weight, the self-adhesiveness and the cut property are poor, and if it exceeds 15% by weight, the self-adhesiveness becomes excessive and the film becomes easy. Can not be pulled out.

For mixing the compounding material and the resin constituting the amorphous resin layer (a) and the polyolefin resin layer (b), known methods such as melt mixing by an extruder and various stirring and mixing devices can be used. .

The resin composition after mixing has a T
A film can be obtained by laminating by a die method or an inflation method. Specifically, the amorphous resin layer (a)
And the polyolefin resin layer (b) are melt-kneaded in separate extruders and supplied to a T-die or a multi-manifold T-die joined to a multi-layer feed block, and the melt-extruded laminated resin is cooled and controlled on a casting roll. And quenching. By quenching the melt-extruded laminated resin, a film having more excellent transparency and tackiness can be obtained. If necessary, lubricants, antioxidants, antistatic agents, flame retardants, fillers, reinforcing agents, release agents, foaming agents, crosslinking agents, fluorescent agents, fungicides, antibacterial agents, processing aids, pigments, A viscosity modifier and the like can be included in the resin composition of the present invention.

In the present invention, the total thickness of the amorphous resin layer (a) and the polyolefin resin layer (b) is 4 to 30 μm, preferably 6 to 1 μm.
6 μm, and the thickness of the amorphous resin layer (a) is 10 to 60% of the total thickness of all the layers. When the total thickness of all the layers is less than 6 μm, the strength as a film is insufficient. 1
When it exceeds 6 μm, the strength as a film becomes too high, and cut property, adhesive property and wrap property are impaired. When the thickness of the amorphous resin layer (a) is less than 10% of the total thickness of all the layers, the heat resistance becomes insufficient, and when it exceeds 60%, the flexibility is reduced, so that the adhesiveness and the lapping property are insufficient. Becomes

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, examples of a wrap film for food packaging according to the present invention will be described with reference to comparative examples, but the present invention is limited to the description of these examples only. is not.

In this embodiment, the die width is 550 mm
The resin layer (a) shown in Table 1 was extruded with a 40 mm diameter, L / D25 extruder, and the resin layer (b) was extruded with a 50 mm diameter, L / D25, using a two-type three-layer feedblock type T-die apparatus. The mixture was melted and kneaded by a machine and taken up by a casting roll adjusted to a temperature of 25 ° C. to obtain a laminated film having a width of 300 mm and a thickness of 10 μm. The layer structure of the laminated film is such that the resin layer (a) is a central layer, the resin layer (b) is a surface layer, and (b) /
(A) / (b) were made into two types and three layers. The thickness configuration of each layer is
The center layer thickness of the resin layer (a) was 2 μm, and the surface layer thickness of the resin layer (b) was 4 μm on one side.

[0024]

Example 1 As an amorphous resin layer (a), Sumitomo Dow Co., Ltd.
Polycarbonate resin (trade name: Caliber 200-)
30, MFR = 30, density 1.20) 95% by weight of terpene resin (trade name: CL, manufactured by Yashara Chemical Co., Ltd.)
A resin composition containing 5% by weight of EARON P-125, a softening point of 125 ° C, and a glass transition temperature of 68 ° C) was used.
As the polyolefin resin layer (b), a polypropylene resin manufactured by Mitsubishi Chemical Corporation (trade name: Novatec PP4400)
F, MFR = 6.0, density 0.90), 88% by weight, a terpene resin (trade name: CLE) manufactured by Yashara Chemical Co., Ltd.
10% by weight of ARON P-125, softening point 125 ° C, glass transition temperature 68 ° C) and 2% by weight of an antifogging agent (trade name: DO-100, polyglycerin oleate) manufactured by Riken Vitamin Co., Ltd. The used resin composition was used.

[0025]

Example 2 As an amorphous resin layer (a), Unitika Ltd.
Polyethylene terephthalate resin (trade name: MA-
2101, IV = 0.64, density 1.34).
Sumitomo Chemical Co., Ltd. as polyolefin resin layer (b)
Low-density polyethylene resin (trade name: Sumikasen CE)
3506, MFR = 5.0, density 0.931) 50% by weight, linear low density polyethylene resin (trade name: Exelen VL800, MFR = 20, density 0.905) 3
8% by weight, alicyclic saturated hydrocarbon resin manufactured by Arakawa Chemical Industry Co., Ltd. (trade name: Alcon P-125, softening point 125 ° C,
Glass transition temperature of 81 ° C.) and 10% by weight of an anti-fogging agent manufactured by Riken Vitamin Co., Ltd. (trade name: Riquemar DO-100,
A resin composition containing 2% by weight of polyglycerin oleate) was used.

[0026]

Example 3 As an amorphous resin layer (a), a methacrylic resin manufactured by Kuraray Co., Ltd. (trade name: EH-1000, MFR =
1.2, density 1.2). As the polyolefin resin layer (b), a low-density polyethylene resin manufactured by Sumitomo Chemical Co., Ltd. (trade name: Sumikasen CE3506, MFR =
5.0, density 0.931), 60% by weight, linear low-density polyethylene resin (trade name: Exelen VL800, M
FR = 20, density 0.905) 28% by weight, terpene resin (trade name: CLEAR, manufactured by Yashara Chemical Co., Ltd.)
ON P-125, softening point 125 ° C, glass transition temperature 6
8 ° C.) and 2% by weight of an antifogging agent (trade name: DO-100, polyglycerin oleate) manufactured by Riken Vitamin Co., Ltd.

[0027]

Comparative Example 1 As an amorphous resin layer (a), Sumitomo Dow
Polycarbonate resin (trade name: Caliber 200-)
30, MFR = 30, density 1.20). As the polyolefin resin layer (b), a polypropylene resin manufactured by Mitsubishi Chemical Corporation (trade name: Novatec PP4400F, M
FR = 6.0, density 0.90) of 98% by weight, and a resin composition containing 2% by weight of an antifogging agent (trade name: DO-100, polyglycerin oleate) manufactured by Riken Vitamin Co., Ltd. Using.

[0028]

Comparative Example 2 Unitika Ltd. was used as the amorphous resin layer (a).
Polyethylene terephthalate resin (trade name: MA-
2101, IV = 0.64, density 1.34).
Sumitomo Chemical Co., Ltd. as polyolefin resin layer (b)
Low-density polyethylene resin (trade name: Sumikasen CE)
3506, MFR = 5.0, density 0.931) 60% by weight, linear low density polyethylene resin (trade name: Exelen VL800, MFR = 20, density 0.905) 3
4% by weight, anti-fogging agent manufactured by Riken Vitamin Co., Ltd. (trade name: D
O-100, polyglycerin oleate) to 6
A resin composition blended by weight% was used.

[0029]

Comparative Example 3 As an amorphous resin layer (a), Unitika Ltd.
Polyethylene terephthalate resin (trade name: MA-
2101, IV = 0.64, density 1.34).
Sumitomo Chemical Co., Ltd. as polyolefin resin layer (b)
Low-density polyethylene resin (trade name: Sumikasen CE)
3506, MFR = 5.0, density 0.931) 40% by weight, linear low-density polyethylene resin (trade name: Exelen VL800, MFR = 20, density 0.905) 3
3% by weight, terpene resin manufactured by Yashara Chemical Co., Ltd. (trade name: CLEARON P-125, softening point 125)
And a glass transition temperature of 68 ° C.) and 2% by weight of an anti-fogging agent (trade name: DO-100, polyglycerin oleate) manufactured by Riken Vitamin Co., Ltd.

[0030]

Reference Examples 1 to 3 A commercially available vinylidene chloride wrap film manufactured by Company A as Reference Example 1, a commercially available polymethylpentene wrap film manufactured by Company C as Reference Example 2, and a polypropylene based wrap film manufactured by Company M as Reference Example 3. A laminated wrap film of resin and nylon resin was used.

[0031]

[Evaluation Method] The film properties of the films of Examples, Comparative Examples and Reference Examples were evaluated by the following evaluation methods, and the evaluation results are shown in Table 1.

(Transparency) Regarding transparency, HAZ was measured using an automatic haze meter (Model NDH-24 manufactured by Nippon Denshoku Industries Co., Ltd.).
The E value was measured.

(Adhesive force) A wrap film cut to 250 mm was cut into an inner diameter of 40 mm, a width of 300 mm, and a weight of 3 kg.
And pressed against the glass plate with a rubber roll, and the T-peel peel strength was measured in the direction of an angle of 150 ° by using a Strograph R2 manufactured by Toyo Seiki.

(Pullability) When the wrap film in the storage box is pulled out by hand, lightly and easily can be pulled out. ○, when the drawer is a little heavy, △, the drawer is heavy and the wrap film jumps out of the storage box. If so ×
And

(Cutability) When the film is pulled out and cut by hand with the breaking blade provided in the storage box, ○ indicates that the film can be easily cut. When it was difficult to cut easily, it was evaluated as x. In addition, when peeling occurred between the resin layers and the film was torn, the film was easily torn in a direction other than the breaking blade, and the handleability was poor.

(Wrapping property) When tableware or food was wrapped with a wrapping film, the case where the degree of flexibility and adhesion was good was evaluated as ○, the case where it was slightly better was evaluated as Δ, and the case where it was poor was evaluated as x.

(Sensory odor) Rice cooled to room temperature is placed in a ceramic bowl, wrapped in a wrap film, and heated in a microwave for 2 minutes to warm the rice. Thereafter, the wrap film was quickly peeled off, and the sensory odor of the wrap film and the rice was evaluated. The case where no odor other than rice was felt was rated as ○, the case where a slight odor other than rice was felt was rated as △, and the case where an odor other than rice was felt was rated as ×.

(Heat resistance) According to Tokyo Metropolitan Ordinance No. 1027, a wrap film is cut into a strip having a width of 30 mm and a length of 140 mm, and jigs sandwiching the entire width are attached to both ends. The distance between jigs is 90mm and one jig is 10g
With the weight suspended, it was placed in a thermostat for 1 hour to determine the temperature at which it did not melt, and was defined as the heat-resistant temperature.

(Anti-fogging property) Distilled water 200 at a water temperature of 20 ± 3 ° C.
ml into a 500 ml beaker, a wrap film is stuck to the beaker opening so as not to wrinkle, and this is immediately put into a commercial refrigerator kept at a temperature of 0 to 3 ° C.
The state change of the wrap film surface was observed. When there were almost no water drops, or when there were a few water drops but within the allowable range, it was evaluated as ○, when there were a few water drops, as Δ, and when there were many water drops, as X.

(Feel) Touch the wrap film directly with your hand,
The case where there was no unpleasant stickiness and the flexibility was good, the case where there was unpleasant sticky feeling was Δ, and the case where the rigidity was high and the flexibility was bad was X.

(Gas Permeability) The permeation amount of oxygen and carbon dioxide was measured using a gas permeation tester Gasperm-100 manufactured by JASCO.

(Moisture Permeability) The permeability was measured by the test method of JIS standard Z0208.

[0043]

[Table 1]

[0044]

As described above, the wrapping film for food packaging according to the present invention comprises a mixture of an alicyclic saturated hydrocarbon resin and a terpene resin alone or in combination of two types.
0.5% to 15% by weight of an alicyclic saturated hydrocarbon resin or a terpene resin alone or in combination of two types on one or both sides of the amorphous resin layer (a) containing 0% by weight, The polyolefin resin layer (b) containing 0.3 to 0.8% by weight is co-extruded and laminated. According to such a composition, there is an effect that a wrap film for food packaging having excellent self-adhesiveness, transparency, cutability, low odor, heat resistance and safety can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 57:02) (C08L 23/00 47:00) (C08L 101/00 57:02) (C08L 101 / 00 47:00) F-term (Reference) 3E086 AB02 AD13 BB15 BB22 BB41 BB58 BB90 4F100 AK01A AK02A AK02B AK02C AK02H AK03B AK03C AK25A AK42A AK45A BA02 BA03 BA06 BA10A BA10BBA10 JBAJJAJJBJAJJBJ10A BA013 BB03X BB05X BB12X BB14X BG05W BK003 CF06W CG00W EH046 GG02

Claims (3)

[Claims] 1. An alicyclic saturated hydrocarbon resin, a terpene resin alone or in combination of two kinds, in an amount of 0 to 10% by weight.
On one or both sides of the compounded amorphous resin layer (a), 0.5 to 15% by weight of an alicyclic saturated hydrocarbon resin or a terpene resin alone or in combination of two kinds, and 0.1% of an antifogging agent.
Polyolefin resin layer (b) containing 3 to 8.0% by weight
Wrap film for food packaging, characterized by being co-extruded and laminated. 2. The food packaging material according to claim 1, wherein said amorphous resin layer (a) comprises one resin layer selected from a polycarbonate resin layer, a methacrylic resin layer and a polyethylene terephthalate resin layer. Wrap film. 3. The total thickness of the amorphous resin layer (a) and the polyolefin resin layer (b) is 4 to 30 μm, and the thickness of the amorphous resin layer (a) is 10% of the total thickness of all the layers. ~
The wrap film for food packaging according to claim 1 or 2, wherein the wrap film is 60%.