JP2003291281A - Antimicrobial and deodorizing film, and package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film and package which are excellent in an antimicrobial property, deodorizing effect and transparency, while the inside surface of a stretched polypropylene film has an anti-fogging property, and are suitable for packaging perishables. <P>SOLUTION: The package film comprises a base layer having a polyolefin resin as the main element, and a multilayer laminate having a seal layer constituted of mainly the polyolefin resin whose melting point is lower than the one of the base layer on the inside surface of the base layer. The seal layer of the antimicrobial and deodorizing package film contains a defogging agent and a polyphenols of 0.1 to 2 pts.wt. as well. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a packaging film and a packaging body, and more particularly to a packaging film and a packaging body having an inner surface sealing layer and having deodorant, antibacterial and antifogging effects, and further, For packaging fresh products consisting of plants or animals requiring high freshness such as vegetables / root vegetables, fruits, flowers, flowering trees, mushrooms, fish, meat (hereinafter, these are referred to as fresh products). It relates to suitable films and packages.

[0002]

2. Description of the Related Art Conventionally, polypropylene films have been widely used in the field of packaging such as food packaging and fiber packaging because of their excellent optical properties, mechanical properties, and packaging suitability. In particular, anti-fog films are widely used in packaging for fresh foods such as vegetables, which are required to maintain freshness.
Further, in recent years, an antibacterial film obtained by coating or kneading an antibacterial agent represented by silver zeolite on a film has come to be used for packaging vegetables and the like.

However, the conventionally known antibacterial polypropylene stretched film cannot obtain sufficient antibacterial property for keeping freshness of vegetables or the like, or the polypropylene antibacterial film is added in a large amount in order to obtain sufficient antibacterial property. However, there is a problem that the transparency, which is a characteristic of the above, is impaired, and there is no packaging body and packaging film that have both antibacterial properties and transparency.

[0004]

The present invention solves the problems of the conventional polypropylene stretched film described above,
It is an object of the present invention to provide a film and a package which have an antifogging property on the inner surface, are excellent in antibacterial and deodorant effects, and are excellent in transparency and suitable for packaging a fresh product.

[0005]

In order to achieve the above object, the packaging film of the present invention comprises (1) a base layer mainly composed of an olefin resin, and a polyolefin-based resin having a lower melting point than the base layer on the inner surface of the base layer. A packaging film comprising a multi-layer laminate having a resin-based seal layer, wherein the seal layer contains an antifogging agent and 0.1 to 2 parts by weight of polyphenols, and (2) the polyphenols are catechins. The antibacterial agent is present in (3) all layers, and (4) biaxially stretched to obtain an antibacterial deodorant packaging film, which can be used for a fresh product package or the like.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the packaging film and the packaging body of the present invention will be described below.

The film used in the present invention comprises a base layer composed mainly of a polypropylene resin and biaxially stretched, and a sealing layer composed mainly of a polyolefin resin having a lower melting point than the base layer formed on the inner surface of the base layer. It is a film of a multilayer laminated body.

Such a film is preferably manufactured by a coextrusion method or an in-line laminating method, but the manufacturing method itself does not limit the present invention. Further, the base layer of the film constituting the present invention needs to be biaxially stretched, but the seal layer formed on the inner surface may be unstretched, uniaxially stretched or biaxially stretched.

Here, as the polyolefin resin suitable for forming the base layer of the film in the present invention, polypropylene resin is particularly excellent, and it is necessary that it has a higher melting point than the polyolefin resin forming the seal layer. When the polypropylene resin suitable for forming the base layer has a lower melting point than the polyolefin resin forming the seal layer, the film sticks to the seal bar during automatic packaging, resulting in defective packaging or a low melting point. Since it is a raw material, the amount of copolymerization components increases and the amount of non-crystalline portions increases, so that the material loses its rigidity and the workability when hand-packing vegetables into bags is significantly reduced, which is not preferable. The polypropylene resin suitable for forming the base layer of the packaging film is not particularly limited as long as it satisfies the above requirements, and examples thereof include isotactic polypropylene and propylene / ethylene copolymer. Polymer, propylene / butene-1 copolymer, propylene / ethylene /
One or more of butene-1 copolymer and propylene / pentene copolymer are used. Still another polyolefin resin, for example, ethylene / butene-1 copolymer,
Ethylene-propylene-butene 1 copolymer, ethylene
Ionomer and polybutene-Acrylic acid copolymer / ethylene / acrylic acid copolymer crosslinked with metal ions
1, butene / ethylene copolymer, etc. may be used in part, and further, polyester resin, polyamide resin,
It is also possible to use a polycarbonate resin or the like within a range that does not impair the characteristics of the film. Further, an ultraviolet absorber, an antioxidant and the like can be optionally mixed.

The polyolefin resin suitable for forming the sealing layer on the inner surface of the packaging film in the present invention is a polyolefin resin having a melting point lower than that of the polypropylene resin forming the base layer, For example, ethylene / butene-1 copolymer, ethylene / propylene / butene-1 copolymer, ethylene / acrylic acid copolymer, ionomer obtained by crosslinking ethylene / acrylic acid copolymer with metal ion, polypropylene,
One or more of polybutene-1, butene / ethylene copolymer, propylene / propylene / butene-1 copolymer, propylene / pentene copolymer and the like are used, and further polyester-based resin, polyamide-based resin, polycarbonate Bonate resins and the like can also be used as long as the characteristics of the film are not impaired. Further, it is preferable that the seal layer on the inner surface of the packaging film in the present invention contains the same or different kinds and amounts of fine particles made of inorganic particles or organic polymers.

The sealing layer of the packaging film of the present invention comprises:
It is necessary to mix 0.1 to 2 parts by weight of polyphenols as an antibacterial agent. If it is less than 0.1 part by weight, the antibacterial and deodorant effects are insufficient, and if it exceeds 2 parts by weight, the transparency is impaired due to coloring and the antibacterial and deodorant effects are saturated.

The polyphenols used in the sealing layer of the packaging film of the present invention are not particularly limited, but it is preferable to use catechin extracted from green tea.

The packaging film of the present invention requires that the surface of the seal layer has antifogging properties. When manufacturing the film,
An antifogging agent may be added to both the resin forming the base layer and the resin forming the seal layer, or a film may be produced by adding the antifogging agent only to the resin forming the base layer. . Even in the latter case, the antifogging agent in the resin that forms the base layer during film production and storage after film formation sequentially migrates to the seal layer over time, and then bleeds out onto the seal layer surface to seal. The surface of the layer has an antifogging property.

On the surface of the seal layer on the side of the packaging film which is in contact with the fresh product, an antifogging agent which exhibits antifogging property during storage or distribution of the fresh product must be present. That is, in the present invention, the antifogging action is extremely important not only for preventing the fogging phenomenon on the inner surface of the package to enhance the commercial value but also for preventing the water content of the package contents from being spoiled due to the water droplets formed by the progress of the fogging. Is a characteristic
Combined with this effect, the antibacterial effect is enhanced, and even if a small amount of antibacterial agent is added, an excellent antibacterial effect is exhibited.

In order to maintain this excellent antifogging property,
Considering the temperature change during storage or distribution, there may be an antifogging agent present on the seal layer surface that continuously exhibits antifogging properties during the course of repeated temperature changes from 5 to 30 ° C. desired. The present invention is intended for packaging perishable products that continue to have physiological effects even after harvesting, and since it is desired to store in a room temperature atmosphere rather than frozen storage, in setting the antifogging property in the present invention, 5 It is preferably determined by the antifogging property when the temperature change is repeated at a temperature of -30 ° C.

Examples of the antifogging agent used include fatty acid esters of polyhydric alcohols, amines of higher fatty acids,
Typical examples include higher fatty acid amides, higher fatty acid amines, and amide ethylene oxide adducts. The amount of such an antifogging agent present in the film is preferably O.1 to 10% by weight, especially O.2 to 5% by weight in terms of the total layer, and 5% by weight or less, particularly 0.
It is preferably from 1 to 1.0% by weight.

The thickness ratio of the heat-sealing layer is not particularly limited, but is usually 1/50 to 1/3 with respect to all layers in the packaging film of the present invention (when heat-sealing layers are provided on both sides of the base layer). Is the total thickness). If the thickness ratio is smaller, the sealing strength will be insufficient and the reliability as a package will be impaired. Further, if the thickness ratio is larger, the proportion of the base layer portion is smaller, so that the entire packaging film becomes less stiff, and the shape of the package after filling with fresh products is unstable, resulting in lack of commercial value. The thickness of the packaging film is
Although not particularly limited, it is about 5 to 250 μm,
The thickness of the seal layer can be appropriately determined within this range.

The method of measuring the characteristic values used in the present specification will be described below.

(1) Transparency (%) Transparency was evaluated by measuring haze in accordance with JIS K7105. The smaller the number, the better the transparency.

(2) Waist: Tensile elastic modulus (MPa) The tensile elastic modulus was measured according to JIS K7127 to evaluate the waist of the film. The higher the value, the stronger the feeling of waist.

(3) 300 cc of warm water at 50 ° C. is put in an anti-fogging 500 cc upper opening container. The container opening is sealed with the film so that the antifogging measurement surface of the film is on the inside. Leave in a cold room at 5 ℃. Leave in a cold room at 5 ℃ for 12 hours, then move to a 30 ℃ environment and leave for 12 hours. After repeating the above operation for 2 days, the state of dew adhesion on the film measurement surface is evaluated on a 6-point scale. Evaluation 6th grade: No dew on the entire surface (adhesion area O) Evaluation 5th grade: Some dew adhesion (adhesion area 1/5) Evaluation 4th: Some dew adhesion (adhesion area 1/4) Evaluation 3rd grade: Approx. 1 Dew adherence of / 2 (adhesion area up to 2/4) Rating 2nd class: Almost dew adhesion (up to 3/4 area) Evaluation 1st level: Dew adhesion over the entire surface (adhesion area 3/4 or more)

(4) As an antibacterial test strain, Escherichia coli IFO 330
1) and Staphylococcus aureus ATCC 653
8P) was used and evaluated by the shake flask method shown below. Put 70 ml of phosphate buffered saline in an Erlenmeyer flask and sterilize by autoclave. 1.5 to 3.0 for this
Add 5 ml of test bacterial solution adjusted to × 10 ⁵ cells,
A 0.75 g test piece cut into 10 mm squares, 320-
After shaking at 340 rpm (25 ° C.) for 1 hour, the number of surviving bacteria was measured.

(5) Deodorizing property A test piece of 150 cm × 150 cm was placed in a collection bag made of aluminum for gas analysis having a volume of 5 liters, and 5 liters of ammonia gas having a concentration adjusted to 250 ppm was injected into the bag after left for 2 hours. The ammonia gas concentration of was measured with a gas detector tube.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples.

Example 1 (1) Resin for forming sealing layer Propylene / ethylene / butene copolymer (ethylene content 2.5 mol%, butyne content 7 mol%, melting point 132 ° C.) 100
Parts by weight, inert fine particles (Sylysia 420, Fuji Silysia Chemical Ltd.)
Made, particle size 1.9 μm) 0.265 parts by weight, antifogging agent (higher fatty acid ester monoglycerite) O.45 parts by weight, catechin (Pharma Foods Co., Ltd.) 0.3 parts by weight so that the resin temperature becomes 240 ° C. Melt-mixed into pellets. 100 parts by weight of this was used as a resin for forming a seal layer.

(2) Base layer forming resin Isotactic polypropylene polymer (melting point 158
C.) 100 parts by weight was mixed with 1.O parts by weight of an antifogging agent (higher fatty acid ester monoglycerite) to prepare a base layer forming resin.

(3) The resin and the resin for film formation were melted at a ratio of 1: 9 (weight ratio) so that the resin temperature was 260 ° C., and a sealing layer was laminated on both surfaces of the base layer in a three-layer state. Co-extruded from T-die, temperature 2
After casting with a casting roll at 5 ° C, the film was stretched 4 times in the machine direction and further stretched 9,5 times in the cross direction.

Next, the corona discharge treatment is applied to the surface of the seal layer of the obtained film, and the wetting tension of the corona discharge treated surface is applied.
390 mN / m, base layer 18 μm, seal layer one side 1 μm, total 20
A μm three-layer packaging film was obtained.

Table 1 shows various properties of the obtained packaging film. As can be seen from this table, in addition to having excellent antifogging properties, it also has excellent transparency, waist (tensile elastic modulus), antibacterial properties and deodorant properties.

Comparative Examples 1 to 3 Films of Comparative Examples 1 to 3 were obtained by changing the amounts of catechins compounded in the seal layer as shown in Table 1 in Example 1. Table 1 shows various properties of the obtained packaging film.

Comparative Example 4 A film obtained in the same manner as in Example 1 except that the resin for forming the seal layer and the resin for forming the base layer were not blended with an antifogging agent was used as Comparative Example 4, and various physical properties were obtained. It shows in Table 1.

Comparative Example 5 A film obtained in the same manner as in Example 1 except that a propylene / butene copolymer (butene content 18 mol%, melting point 129 ° C.) was used as the resin for forming the base layer. Comparative Example 5
And various physical properties are shown in Table 1.

Since Comparative Example 1 does not contain catechin, the antibacterial and deodorant effects are inferior.

Comparative Example 2 is inferior in antibacterial and deodorant effects because the amount of catechin is small.

Comparative Example 3 contained a large amount of catechin, was inferior in transparency, and had a poor appearance when the contents were put therein.

Comparative Example 4 has no anti-fogging property, the appearance of the contents when put in is deteriorated due to dew condensation, and the antibacterial effect is poor.

Comparative Example 5 is a film having a low tensile elastic modulus and no stiffness, which deteriorates the workability in filling the contents and the workability in handling the product, and also causes the product to be stretched at the time of display. There is no reduction in commercial value.

[0038]

[Table 1]

[0039]

EFFECT OF THE INVENTION According to the packaging film and package of the present invention, it is possible to impart transparency, antibacterial property and deodorant property while having excellent antifogging property in packaging of fresh products.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3E067 AB02 AB04 AB08 AB09 BA17A                       BB14A BB18A BB22A BB25A                       CA11 CA24 CA30 GC05 GD01                 3E086 AC07 AC22 BA04 BA15 BB06                       BB22 BB51 BB85 BB90 CA01                       CA17 CA18 CA19 DA01                 4F100 AH02B AK03A AK03B AK04J                       AK07 AK07J AK09J AT00A                       BA02 BA07 CA10B EH20                       EJ38 GB15 JA04B JC00                       JL12B JN01 YY00B

Claims (5)

[Claims] 1. A packaging film comprising a multi-layer laminate comprising a base layer composed mainly of an olefin resin and a seal layer composed mainly of a polyolefin resin having a melting point lower than that of the base layer on the inner surface of the base layer. An antibacterial deodorizing packaging film containing 0.1 to 2 parts by weight of polyphenols together with an antifogging agent. 2. The antibacterial deodorant packaging film according to claim 1, wherein the polyphenols are catechins. 3. The antibacterial deodorant packaging film according to claim 1, wherein an antifogging agent is present in all layers. 4. The film for antibacterial deodorant packaging according to claim 1, which is biaxially stretched. 5. A perishable product package comprising the antibacterial deodorant packaging film according to any one of claims 1 to 4.