JPH08300582A - Laminated film for packaging mushrooms and mushroom packaging body - Google Patents

Abstract

PURPOSE: To provide a laminated film for packaging mushrooms having excellent fog resistance, proper water vapor permeability, oxygen permeability, and carbon dioxide permeability, and provide a mushroom packaging body capable of keeping freshness of mushrooms packaged by the laminated film for a long time. CONSTITUTION: In a laminated film 2 for packaging mushrooms, a straight chain ethylene/α-olefin copolymer resin layer is laminated on both faces of a polyamide resin layer and a layer to be in contact with the mushrooms 1 contains a fog resisting agent. In this mushroom packaging body, the mushrooms 1 are packaged by the laminated film 2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminated film for packaging mushrooms suitable for packaging mushrooms such as mushrooms, shiitake mushrooms and shimeji mushrooms, and a mushroom package capable of maintaining freshness of mushrooms for a long period of time. is there.

[0002]

2. Description of the Related Art Mushrooms, like fruits and vegetables such as bell peppers and cucumbers, have a respiratory action even after harvesting, and it is known that their activity is higher than that of fruits and vegetables, and that quality deterioration thereof is faster. Therefore, in the packaging body that wrapped mushrooms,
Oxygen concentration decreases with the passage of time, and conversely, carbon dioxide concentration increases, causing heat generation, which leads to an increase in temperature inside the package. Also, due to this temperature increase, the respiratory action and transpiration action of mushrooms become more active,
Further, deterioration of the quality of mushrooms due to decay due to stuffiness, discoloration of brown to black or brown, and generation of mold will be accelerated.

At present, polyvinyl chloride stretch film is mainly used for packaging mushrooms. But,
Polyvinyl chloride film has a high water vapor transmission rate, which causes the mushrooms to wither, and harmful gases containing chlorine are generated during incineration, which causes environmental pollution and other problems, so a low density alternative Films based on ethylene resins such as polyethylene resins and ethylene / vinyl acetate copolymer resins are being actively developed.

However, since the films made of these ethylene resins have a large oxygen permeability, the respiratory action of mushrooms becomes active, and the moisture vapor permeability is low, so that the inside of the package becomes damp and the quality of mushrooms deteriorates rapidly. There was a problem. For the purpose of improving these drawbacks, JP-A-62-62
No. 235086 discloses a carbon dioxide gas permeability of 40,000 to 180,00 for covering mushrooms in a substantially sealed state.
Water vapor permeability of 8 at 0 cc / m ² · 24 hours · atm
One or more having an opening area equivalent to a circular hole with a diameter of 0.1 mm to 5.0 mm per 500 g of mushrooms packaged in a polyvinyl chloride or polyethylene film of 00 g / m ² · 24 hours · atm. Mushroom packages provided with holes have been proposed.

However, the film is perforated.
Has a high carbon dioxide permeability, resulting in respiratory action
It is essential to keep the quality of mushrooms active
Was not enough. In addition, JP-A-4-5776
No. 3 gazette contains mushrooms in a container with an open top.
The water vapor transmission rate when packaging with a thin transparent film
Is 20 to 500 g / m ²・ 24 hours (38 ° C)
Oxygen gas permeation rate is 2,000 to 30,000 ml / m
²・ 24 hours ・ Atm (23 ℃) thin transparent film
With use, the film will not come into contact with mushrooms
Saturated fatty acid having 14 to 22 carbon atoms and po
With a surfactant mainly composed of lyol ester
A packaging method characterized by the following is proposed.

However, the above film only controls the water vapor and oxygen permeability, and does not control the carbon dioxide gas permeability, which has the greatest effect on controlling the respiratory action of mushrooms, and does not necessarily retain freshness. Was not.

[0007]

DISCLOSURE OF THE INVENTION As a result of extensive studies aimed at solving the problems existing in the above-mentioned prior art, the present invention has excellent antifogging property, moderate water vapor permeability, oxygen permeability and appropriateness. An object of the present invention is to provide a laminated film for packaging mushrooms having excellent carbon dioxide gas permeability, and a mushrooms package capable of maintaining freshness of mushrooms for a long period of time by the laminated film.

[0008]

The present invention is a layer in which a linear ethylene / α-olefin copolymer resin (B) layer is laminated on both sides of a polyamide resin (A) layer and which is in contact with mushrooms. A laminated film for packaging mushrooms, characterized by containing an antifogging agent, and after placing mushrooms on a tray etc., the whole was packaged with the laminated film, or made into a bag from the laminated film. The present invention relates to a mushroom package which is stored in a thing.

The present invention will be described in detail below. The polyamide resin (A) which is the intermediate layer of the laminated film for packaging mushrooms according to the present invention includes nylon 6 and nylon 1.
1, nylon 12, nylon 66, nylon 610, nylon 6/12 copolymer, nylon 12/6 copolymer,
Crystalline polyamide resin such as nylon 6/66 copolymer and nylon 6/66/12 copolymer, and melting point 145
Copolymer elastomer of polyoxyalkylene glycol and ω-laurolactam having a density of 1.01 to 1.02 g / cm ³ at 180 ° C. [for example, E40 and E47 of Daiamide-PAE manufactured by Daicel Hüls Ltd. First name]. These may be used alone or in combination of two or more.

Among them, nylon 6/66 copolymer resin,
Nylon 12/6 copolymer resin is preferable in terms of balancing the above-mentioned water vapor permeability, oxygen permeability and carbon dioxide gas permeability. This polyamide resin (A) layer moderately enhances the permeation of water vapor and lowers the permeation of oxygen and carbon dioxide.

The resin for the inner and outer layers laminated on both sides of the intermediate layer in the laminated film for packaging mushrooms of the present invention is a linear ethylene / α-olefin copolymer resin (B). The linear ethylene / α-olefin copolymer resin (B) is a copolymer containing ethylene as a main component and α-olefin alone or as a mixture of two or more kinds. Preferred α-olefins are α-olefins having 4 to 8 carbon atoms such as butene-1, hexene-1, 4-methylpentene-1, octene-1, and the content of α-olefin is 10 to 30% by weight. , Preferably 12
~ 26% by weight.

When the content of α-olefin is less than 10% by weight, the obtained film tends to be hard, which lowers tear strength and the like, resulting in poor packaging suitability.
If it exceeds 30% by weight, film forming tends to be difficult. The linear ethylene / α-olefin copolymer resin (B) has a density of 0.905 g / cm ³ or less,
It is preferably 0.902 g / cm ³ or less, more preferably 0.900 g / cm ³ or less, and the Q value (Mw / Mn) is 4.0 or less, preferably 2.0 to 3.0, and MFR 0.
A linear ethylene / α-olefin copolymer resin of 5 to 5 g / 10 min is preferable.

When the density exceeds 0.905 g / cm ³ , the film appearance tends to be deteriorated, while the density is 0.9
Even if it is less than 05 g / cm ³ and the Q value is more than 4.0, the film appearance tends to be poor. Such a linear ethylene / α-olefin copolymer resin (B) uses a transition metal compound as a catalyst, a so-called Ziegler-Natta type catalyst, or an organometallic complex in the presence of a so-called metallocene catalyst or the like, Ethylene and α
-Ion-polymerized from olefins.

Further, as the manufacturing process, a high pressure method, a gas phase method, a solution method, which is used in general polyolefin manufacturing,
A slurry method and the like can be mentioned. The linear ethylene / α-olefin copolymer resin (B) used in the present invention is preferably a metallocene catalyst for controlling the relationship between the density and the Q value. This metallocene catalyst is a transition metal (F
(e, Ti, Zr, Hf, etc.) is sandwiched between unsaturated cyclic compounds, and precise control of stereoregularity, molecular weight, copolymerizability, etc. is possible.

The conventional Ziegler-Natta type catalysts and the like are called multi-site catalysts (MSCs) because they have mixed active sites with different properties. At the same time, a low molecular weight component other than the target molecular weight is obtained, and the film is transparent. Performance and heat sealability are deteriorated. On the other hand, the metallocene catalyst is called a single-site catalyst (SSC) because it has a uniform catalytic active site, and a homogeneous polymer having a narrow molecular weight distribution can be obtained. The molecular weight distribution related to processability and the composition distribution related to product properties are Can be controlled arbitrarily.

Such a metallocene-catalyzed linear ethylene
The α-olefin copolymer is available from Dow Chemical Japan KK as AFFINITY “FM1570”, “P
It is sold under the trade name of L1840 ". This linear ethylene / α-olefin copolymer resin (B) is adhesive to the laminated film for packaging mushrooms, or has heat sealability during bag formation and suitability for packaging. To improve.

The inner and outer layers have an ethylene / vinyl acetate copolymer (vinyl acetate content of 5 to 30% by weight) and an ethylene / acrylic acid copolymer (acrylic acid content of 5 to 5 for the purpose of improving packaging suitability. 20% by weight), ethylene / methyl methacrylate copolymer, ethylene, propylene and the like α
-Metal salt of a copolymer of olefin and a monomer selected from acrylic acid, methacrylic acid, maleic acid, etc. (Zn, N
a, K, Li, Mg, etc.) and the density is 0.920 to 0.93.
5 g / cm ³ , low density polyethylene having an MFR of 0.1 to 10 g / 10 minutes, and a density of 0.8 other than those used for the inner and outer layers
86 to 0.920 g / cm ³ linear low density polyethylene, maleic anhydride grafted ethylene / vinyl acetate copolymer, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, ethylene / acrylic acid lower alkyl ester / maleic anhydride An acid terpolymer or the like may be blended. These may be used alone or in combination of two or more.
It is possible to add 5 to 40% by weight, preferably 1 to 30% by weight.

Similarly, the intermediate layer may be blended in an amount of 0.5 to 40% by weight, and further, it may be interposed as an adhesive layer between the intermediate layer and the inner and outer layers. The linear ethylene / α-olefin copolymer resin (B) in the layer in contact with mushrooms of the laminated film for packaging mushrooms of the present invention contains an antifogging agent. The antifogging agent of the present invention is for imparting antifogging property and appropriate slipperiness, self-adhesiveness, antistatic property, and even if it is usually sold as an antistatic agent, The antifogging agent of the present invention can be said as long as it exhibits the effect of the property.

Specific examples of the antifogging agent include, for example, an aliphatic alcohol having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms,
An aliphatic alcohol fatty acid ester which is a compound with a fatty acid having 10 to 22 carbon atoms, preferably 12 to 18 carbon atoms,
Specifically, monoglycerin oleate, polyglycerin oleate, glycerin triricinoleate, glycerin acetyl ricinoleate, polyglycerin stearate, polyglycerin laurate, methyl acetyl ricinoleate, ethyl acetyl ricinoleate, butyl acetyl ricinoleate, propylene glycol Oleate, propylene glycol laurate, pentaerythritol oleate, polyethylene glycol oleate, polypropylene glycol oleate, sorbitan oleate, sorbitan laurate, polyethylene glycol sorbitan oleate, polyethylene glycol sorbitan laurate, etc.
In addition, polyalkylene ether polyols, specifically, polyethylene glycol, polypropylene glycol and the like can be mentioned. The content of the antifogging agent is 0.1 to 10% by weight, preferably 1 to 6% by weight of one or more of the above antifogging agents.

The antifogging agent is also added to the linear ethylene / α-olefin copolymer resin (B) in the layer not in contact with mushrooms or the polyamide resin (A) in the intermediate layer in an amount of 0.1.
It may be contained in an amount of 10% by weight. In addition to the antifogging agent,
A freshness-retaining agent such as hinokitiol or zeolite may be added to the inner and outer layers and the intermediate layer for the purpose of sterilization, mildew proofing, and ethylene adsorption.

The laminated film for packaging mushrooms of the present invention comprises
Using a plurality of extruders, the polyamide resin (A) and the linear ethylene / α-olefin copolymer resin (B) are subjected to a known method such as a coextrusion method by inflation molding or T-die molding, or an extrusion laminating method. Are laminated and molded. Among them, in order to obtain a laminated film having a sufficient balance of mechanical strength such as tear strength in the machine direction and the transverse direction, a coextrusion method by inflation molding is preferable,
The blow ratio at that time is 3 to 20 times, preferably 5 to 18 times.

The blow ratio here means the ratio of the circumferential length of the final blown film to the circumferential length of the die slit of the die. The total thickness of the laminated film for packaging mushrooms is 8 to 30 μm, of which the intermediate layer has a thickness of 1 to 10 μm.
It is preferable that each of the inner and outer layers has a thickness of 4 to 10 μm.
In addition, when the laminated film for packaging mushrooms requires heat shrinkability, it is uniaxially stretched 1.2 to 5 times in the film take-up direction or 3 times or more in each of the longitudinal and transverse directions of the film. Axial stretched ones are preferred.

The laminated film for packaging mushrooms of the present invention is
Its water vapor permeability is 100 to 600 g / m ² · 24 hours · atm, and oxygen permeability is 400 to 10,000 cc / m ^2.
・ 24 hours ・ atm, and carbon dioxide permeability of 1.00
0 to 35,000 cc / m ² · 24 hours · atm, preferably water vapor permeability of 100 to 500 g / m ² · 24 hours · atm, oxygen permeability of 400 to 8,000 cc / m ² ·
24 hours atm and carbon dioxide permeability of 1,500
~ 30,000 cc / m ² · 24 hours · atm,
It is suitable for controlling respiration and transpiration of mushrooms, and is suitable as a film capable of maintaining freshness of mushrooms for a long time.

As a form of packaging mushrooms with the laminated film for packaging mushrooms of the present invention, a bag-shaped bag made of the laminated film is directly packed with mushrooms,
Mushrooms are stored in a tray or the like, and the entire tray or the like is wrapped with a laminated film for packaging mushrooms. As the material for the tray and the like, those made of plastic or paper can be used, and specific examples thereof include expanded polystyrene and impact resistant polystyrene, but are not limited thereto. Further, as a shape, a shallow container or a deep container can be used. For example, FIG. 1 shows an example in which mushrooms 1 are stored in a tray 3 and the entire tray 3 is stretch-wrapped with a laminated film 2 for packaging mushrooms.

[0025]

EXAMPLES The contents and effects of the present invention will be described below in more detail with reference to Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Incidentally, in the following examples, the evaluation of the obtained laminated film for mushrooms packaging, practicality and packaging suitability were carried out by the following method, and the evaluation results, practicality and The packaging suitability is shown in Table 1.

<Water Vapor Permeability> JIS K 7129 <Oxygen Permeability and Carbon Dioxide Gas Permeability> JIS Z 1707

<Anti-fog property> After placing a raw mushroom on a tray made of impact-resistant polystyrene, it was stretch-wrapped on the film and the anti-fog property of the film after 4 days was visually observed. ◯: The product has a good appearance with no fogging or water droplets attached to the inner surface of the film. Δ: Fogging or a small amount of water droplets is present on the inner surface of the film. Poor: The appearance of the product was poor due to noticeable cloudiness or water droplets on the inner surface of the film.

<Preservability> Mushroom packaging was carried out in the same manner as in the evaluation of antifogging property, and the freshness of fresh mushrooms was visually observed. X: The freshness was good, but less than 5 days. Δ: The freshness was good for 5 to 7 days. ◯: Freshness was good, but more than 7 days.

<Extensible> Raw mushrooms are placed on trays made of expanded polystyrene, expanded polystyrene, and impact-resistant polystyrene, and packed by an automatic stretch wrapping machine, A-18X [trade name] manufactured by Fujikikai Co., Ltd. Then, the stretched state of the film at that time was visually observed. ◯: The film stretches almost uniformly. X: The film stretches unevenly.

<Break Occurrence Status> Packaging was performed in the same manner as in the extensibility evaluation, and the presence or absence of breakage of the film at that time was visually observed.

<Wrinkle Occurrence State> Packaging was performed in the same manner as in the extensibility evaluation, and the presence or absence of wrinkles in the film at that time was visually observed.

Example 1 Nylon 6/66 copolymer resin [density 1.13 g / cm ³ , melting point 192 ° C .; trade name “Novamid EN220-5C” manufactured by Mitsubishi Chemical Co., Ltd. as a resin for the intermediate layer
S ”] using an extruder of 65 mm in diameter and L / D25
Kneading was performed at 30 ° C., while a linear ethylene / α-olefin copolymer resin [density 0.895 was used as the resin for the inner and outer layers.
g / cm ³ , Q value 2.26, MFR 1.6 g / 10 min, α
-Olefin: Octene-1 (content: 14.5% by weight); Dow Chemical Japan KK, trade name "AF
FINITY PF1140 "] 98.5% by weight and diglycerin oleate [manufactured by Riken Vitamin Co., Ltd., trade name" Rikemar O71D "] 1.5% by weight, with a resin composition of 50 mm in diameter, L / D25 extruder. Using 19
The mixture was kneaded at 0 ° C., and both were supplied to one annular three-layer die so that inner and outer layers each having a thickness of 5 μm were laminated on both sides of an intermediate layer having a thickness of 3 μm, and a die temperature of 230 ° C. A blown film was blow-molded at a blow ratio of 10 to produce a laminated film for packaging mushrooms having an overall thickness of 13 μm (5 μm / 3 μm / 5 μm). Table 1 shows the evaluation results, practicality and packaging suitability of the laminated film.

Example 2 Nylon 12 resin was used as the intermediate layer resin in Example 1.
[Density 1.02 g / cm ³, Melting point 155 ° C .; Daicel He
Product name "Daiamide N1901" manufactured by Urs Co., Ltd.]
Instead of the resin for the inner and outer layers, use linear ethylene / α-olefin.
Incopolymer resin [Density 0.902g / cm³, Q value 2.
20, MFR 1.0 g / 10 minutes, α-olefin: Oct
Ten-1 (content 12.0% by weight); Dow Chemical Di
Product name "AFFINITY PL18" manufactured by CAPAN Co., Ltd.
80 "] 98.5% by weight and sorbitan oleate [RIKEN
Vitamin Co., Ltd., trade name "Rikemar O250"]
Except for replacing with a resin composition of 1.5% by weight,
In the same way, a laminated film for packaging mushrooms with a three-layer structure
Manufactured. Evaluation results, practicality and packaging of the laminated film
The suitability is shown in Table 1.

Example 3 In Example 1, the resin for the inner and outer layers was linear ethylene.
α-Olefin Copolymer Resin [Density 0.870 g / c
m ³ , Q value 2.0, MFR 1.0 g / 10 min, α-olefin: octene-1 (content 24.0% by weight); Dow
Product name “ENGAGE E” manufactured by Chemical Japan Co., Ltd.
G8100 "] 98.0% by weight and glycerin monooleate [manufactured by Riken Vitamin Co., Ltd., trade name" Rikemar OL "
-100 "] A laminated film for packaging mushrooms having a three-layer structure was produced in the same manner as in the same example except that the resin composition was changed to 2.0% by weight. Evaluation results of this laminated film,
Table 1 shows practicality and suitability for packaging.

Example 4 In Example 1, the resin for the intermediate layer was nylon 6/66.
Copolymer resin [density 1.13 g / cm ³ , melting point 196 ° C .;
BASF Engineering Plastics Co., Ltd., trade name "Ultramid C35"] in place of the resin for the inner and outer layers, the linear ethylene / α-olefin copolymer resin 95% by weight used in the same example, ethylene / ethyl acrylate・
Maleic anhydride terpolymer resin [Density 0.930 g /
cm ³ , MFR 5.0 g / 10 minutes, melting point 107 ° C .; Sumitomo Chemical Co., Ltd., trade name “Bondaine LX411
0 "] 3.0 wt%, diglycerin oleate used in the same example 1.0 wt% and glycerin monooleate used in Example 3 1.0 wt% except that the resin composition was replaced,
A three-layered laminated film for packaging mushrooms was produced in the same manner as in the same example. Table 1 shows the evaluation results, practicality and packaging suitability of the laminated film.

Comparative Example 1 In Example 1, the resin for the intermediate layer was polybutene-1 resin [density 0.908 g / cm ³ , MFR 1.0 g / 10.
Min; Mitsui Petrochemical Industry Co., Ltd., trade name "Polybutene"
M8640 "], a linear ethylene / α-olefin copolymer resin [density 0.920 g /
cm ³ , MFR 2.0 g / 10 min; Mitsubishi Chemical Co., Ltd., trade name “Mitsubishi Polyechie LL SF240”] 98.5% by weight and a resin composition comprising 1.5% by weight of diglycerin oleate used in the same example. A laminated film having a three-layer structure was produced in the same manner as in the same example except that the above was replaced with. Table 1 shows the evaluation results, practicality and packaging suitability of the laminated film.

Comparative Example 2 Linear ethylene / α-olefin copolymer resin [density 0.920 g / cm ³ , MFR 2.1 g / 10 min; manufactured by Mitsubishi Chemical Corporation, trade name "Mitsubishi Polyechie LL UF24"
0 "] 98.0% by weight and the diglycerin oleate used in Example 1 2.0% by weight, a caliber of 5
Knead at 190 ° C using 0 mm, L / D25 extruder,
By inflation molding with a blow ratio of 10 times, a single-layer film having a thickness of 13 μm was manufactured. Table 1 shows the evaluation results, practicality and packaging suitability of the single layer film.

[0038]

[Table 1]

[0039]

EFFECT OF THE INVENTION The laminated film for packaging mushrooms of the present invention is excellent in antifogging property, and has appropriate water vapor permeability, oxygen permeability,
Mushroom packaging wrapped with the laminated film, which has carbon dioxide permeability, has a particularly advantageous effect that the freshness of mushrooms can be maintained for a long period of time, and its industrial use. The value is extremely large.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a mushroom package of the present invention.

[Explanation of symbols]

 1 Mushroom 2 Laminated film for packaging mushrooms 3 Tray

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 27/34 B32B 27/34 B65D 65/40 B65D 65/40 A 75/26 75/26 85 / 50 85/50 A

Claims (7)

[Claims] 1. A straight-chain ethylene / α-olefin copolymer resin (B) layer is laminated on both sides of a polyamide resin (A) layer, and an antifogging agent is contained in a layer in contact with mushrooms. A laminated film for packaging mushrooms, which is characterized by being present. 2. The linear ethylene / α-olefin copolymer resin (B) has a density of 0.905 g / cm ³ or less, and
Q value (Mw / Mn) is 4.0 or less, The laminated film for packaging mushrooms of Claim 1 characterized by the above-mentioned. 3. The laminated film for packaging mushrooms according to claim 1, wherein the antifogging agent is an aliphatic alcohol fatty acid ester or / and a polyalkylene ether polyol. 4. The laminated film for packaging mushrooms has a water vapor permeability of 100 to 600 g / m ² · 24 hours · atm and an oxygen permeability of 400 to 10,000 cc / m ² · 24 hours ·
atm and carbon dioxide gas permeability of 1,000 to 35,0
The laminated film for packaging mushrooms according to any one of claims 1 to 3, wherein the laminated film is 00cc / m ² · 24 hours · atm. 5. Mushrooms are placed on a tray or the like, and then the whole is wrapped with a laminated film for packaging mushrooms, the film comprising linear ethylene.α- on both sides of a polyamide resin (A) layer. An olefin copolymer resin (B) layer is laminated,
A mushroom package comprising an antifogging agent in a layer in contact with mushrooms. 6. A mushroom is laminated with a laminated film for packaging mushrooms into a bag shape, and the film is packaged on both surfaces of a polyamide resin (A) layer.
A mushroom package, characterized in that an olefin copolymer resin (B) layer is laminated, and an antifogging agent is contained in a layer in contact with the mushroom. 7. The linear ethylene / α-olefin copolymer resin (B) has a density of 0.905 g / cm ³ or less, and
Q value (Mw / Mn) is 4.0 or less, The mushrooms packaging body of Claim 5 thru | or 6 characterized by the above-mentioned.