JP2019069817A - Plastic film for keeping freshness and packaging material - Google Patents

Abstract

To provide a plastic film which exhibits an excellent effect on keeping freshness and deodorization a perishable product such as vegetables and fruits, and a packaging material using the same.SOLUTION: A plastic film of the present invention contains resin, zeolite, an inorganic deodorant other than zeolite, and an antifogging agent. The inorganic deodorant is preferably an inorganic deodorant for sulfur-based gas. It is also preferred that the resin comprises a polyolefin, more preferably a polyethylene. The plastic film is suitable as a packaging material used for keeping the freshness of fruits and vegetables that generate an odor component containing a sulfur-based compound.SELECTED DRAWING: None

Description

  The present invention relates to a plastic film for maintaining freshness and a packaging material using the same.

BACKGROUND ART Conventionally, for fresh produce such as fruits and vegetables, it is an important issue to maintain the freshness from transportation from a production area to a consumption place until it is sold. For example, harvested fruits and vegetables are packaged and stored and transported in plastic film packaging materials, but carbon dioxide gas, aldehydes, alcohols, esters, etc. are generated during that time to reduce freshness. It has been known. In addition, plants of the family Brassicaceae such as broccoli are known to generate an odor component containing a sulfur-based compound such as methyl mercaptan and dimethyl disulfide by storing under anaerobic conditions.
As a plastic film for the purpose of maintaining freshness and deodorizing fresh products such as fruits and vegetables, for example, those described in Patent Document 1 are known.

Unexamined-Japanese-Patent No. 1-207333

  However, in the method described in Patent Document 1, there is still room for improvement in freshness retention and deodorization.

  Accordingly, an object of the present invention is to provide a packaging material that can eliminate the drawbacks of the above-mentioned prior art, and specifically, exerts an excellent effect on maintaining freshness and deodorizing fresh products such as fruits and vegetables. , A plastic film and a packaging material using the same.

  The present invention provides a plastic film for maintaining freshness, which contains a resin, zeolite, an inorganic deodorant other than zeolite, and an antifogging agent.

  The present invention also provides a packaging material comprising the plastic film.

  According to the present invention, a plastic film and a packaging material using the same are provided that exhibit excellent effects of maintaining freshness and deodorizing fresh products such as fruits and vegetables.

The present invention will be described below based on its preferred embodiments.
The plastic film of the present embodiment contains a resin, zeolite, an inorganic deodorant other than zeolite, and an antifogging agent.

(resin)
In the present invention, the resin is preferably made of a thermoplastic resin in view of processability and manufacturing cost. As the thermoplastic resin, for example, although it can be used without particular limitation, for example, polyolefin, polyester, polyamide, polyvinyl chloride, polyimide, ethylene / vinyl acetate copolymer or its saponified product, polyvinyl alcohol, polyacrylonitrile, polycarbonate, polystyrene And biodegradable resins such as ionomers, polylactic acid and polybutylene succinate, and mixtures thereof.

  As polyolefin, the homopolymer or copolymer of alpha-olefins, such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl 1-pentene, 1-octene, is mentioned. Specifically, polyethylene such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), polypropylene, propylene -Alpha-olefin random copolymer, propylene-based polymer such as propylene block copolymer, poly 1-butene, poly 4-methyl 1-pentene, etc. may be mentioned.

Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like.
Moreover, as a polyamide, nylon-6, nylon-66, polymetaxylene adipamide etc. are mentioned.

  In the present invention, it is preferable to use a polyolefin as the thermoplastic resin in terms of transparency, rigidity, manufacturing cost, processability, sealability, etc., and in particular polyethylene in terms of transparency, manufacturing cost, processability, sealability. It is preferable to use In particular, linear low density polyethylene (LLDPE) or low density polyethylene (LDPE) is preferably used as the resin from the viewpoint of production cost and processability, and in particular, it is preferable to use LLDPE and LDPE in combination to achieve a balance of appropriate rigidity. It is preferable from the point of obtaining strength and processability. As a quantitative ratio when combining LLDPE and LDPE, a plastic film having desirable physical properties and processability is obtained that LLDPE is 65 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass in total of LLDPE and LDPE. It is preferable at a point, and it is especially preferable that it is 70 to 90 mass parts.

When using a polyolefin as the thermoplastic resin, the polyolefin, a density 0.900 g / cm ³ or more 0.950 g / cm ³ or less, particularly 0.910 g / cm ³ or more 0.930 g / cm ³ using the following ones However, it is preferable in terms of processability, impact resistance, balance of rigidity, transparency, and sealability. Further, the melt index (MI) of the polyolefin is 0.3 or more and 10.0 or less, particularly 0.5 or more and 2.0 or less, and the balance of processability, rigidity, transparency, impact resistance, sealability Preferred in terms of Here, the measurement of the melt index is in accordance with JIS K 7210 “Test method of melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastics”, polyethylene resin has a temperature of 190 ° C. and a load of 2.16 kgf To do.

(Zeolite)
Zeolite is a crystal mainly composed of aluminum (Al) and silicon (Si), and has a structure in which silicon and aluminum are bonded via oxygen (O). In the zeolite crystals, there are a large number of very small holes called micropores, which can adsorb molecules or allow molecules to be chemically reacted inside. Zeolites include natural zeolites and artificial zeolites, any of which may be used. Zeolites also have ion exchange sites depending on the number of aluminum atoms in their crystals, and are capable of exchanging counter cations. For example, those in which the counter cation is a sodium ion are referred to as sodium type, those in which an ammonium ion is referred to as ammonium type and the like. Zeolite is considered to contribute to retention of freshness by adsorbing carbon dioxide gas, water, ethylene gas and ammonia gas. In the present invention, it is preferable to use a zeolite excellent in the adsorptivity of ethylene gas which is considered to most affect freshness retention. In the present invention, it is preferable to use a synthetic zeolite which can be easily controlled, since the adsorption properties of the zeolite depend on the size of the pore size, the crystal structure and the type of cation.

  It is preferable that the plastic film of the present invention contains 0.5 parts by mass or more of zeolite with respect to 100 parts by mass of the resin in terms of enhancing the freshness holding and deodorizing effects. The content of zeolite is preferably 3.0 parts by mass or less with respect to 100 parts by mass of the resin from the viewpoint of processability and transparency. From these points, the amount of zeolite is more preferably 0.5 parts by mass or more and 3.0 parts by mass or less, and 1.0 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the resin. Is particularly preferred.

(Inorganic deodorant)
As the inorganic deodorant, it is an inorganic deodorant for sulfur-based gas having a deodorizing effect on an odor component comprising a sulfur-based gas containing a sulfur-based compound such as hydrogen sulfide and methyl mercaptan, in particular, The obtained plastic film is preferable in that it is suitable for use for maintaining the freshness of perishables that easily emit sulfur-based gas, such as cruciferous plants. As such inorganic deodorizers, hydroxides or hydrous oxides of zirconium or lanthanoid elements; metals (zirconium, titanium, tin) phosphate carrying zinc ions and / or manganese (II) ions; fine particles Zinc oxide; metal silicate containing at least one metal selected from copper, zinc, manganese, cobalt and nickel; porous silicon dioxide carrying a compound having an amino group, and the like.

In particular, it is preferable to use a metal silicate containing at least one metal selected from copper, zinc, manganese, cobalt and nickel, from the viewpoint of high deodorizing and freshness maintaining effects when combined with zeolite and antifogging agent. . Such metal silicates can be produced by reacting metal salts with alkali silicates. As said metal salt, inorganic salts, such as a sulfuric acid, hydrochloric acid, nitric acid, of at least 1 sort (s) of metal chosen from copper, zinc, manganese, cobalt, nickel can be used. Among these, copper (I), copper (II) and zinc (I) are preferred as the metal. As the _{silicate, M 2 O · nSiO 2 ·} xH 2 O ( wherein, M in the formula represents a monovalent alkali metal, n represents 1 or more, and x is 0 or more.) Formula Kay Acid alkali salts can be mentioned. The metal silicates are sometimes referred to as amorphous complexes of metal salts and silicates. The preferred molar ratio of metal to silicon in the metal silicate is in the range of metal / silicon = 0.60 to 0.80. The average particle diameter of the inorganic deodorant is preferably 1 μm to 15 μm, and more preferably 2 μm to 5 μm. The average particle size referred to herein indicates the median diameter d50 of the volume-based particle size distribution. The complex (metal silicate) of a metal salt containing at least one metal selected from copper, zinc, manganese, cobalt, and nickel and a silicate (metal silicate) is disclosed, for example, in The thing as described in the 2011-104274 gazette can be used without particular limitation. For example, as an example of the above-mentioned complex (metal silicate), Kesmon (registered trademark) NS-10C and NS-20C manufactured by Toagosei Co., Ltd. can be mentioned as commercial products.

  It is preferable that the plastic film of the present invention contains 0.1 parts by mass or more of the inorganic deodorant with respect to 100 parts by mass of the resin, in order to further enhance the deodorizing effect on the odor component containing the sulfur compound. The content of the inorganic deodorant is preferably 0.6 parts by mass or less with respect to 100 parts by mass of the resin in terms of cost, processability, and transparency. From these points, the amount of the inorganic deodorant is more preferably 0.2 parts by mass or more and 0.4 parts by mass or less with respect to 100 parts by mass of the resin.

(Anti-fog agent)
An antifogging agent is generally a plastic film for the purpose of preventing fogging of the surface of a plastic film or sheet generated due to solidification of water vapor in the atmosphere and formation of water droplets on the surface and securing visibility. It is applied to the surface of or kneaded with the inside and used. In the present invention, by combining the zeolite and the antifogging agent with a specific inorganic deodorant, it exerts an excellent effect on deodorizing and maintaining freshness of fresh produce, particularly fruits and vegetables capable of generating an odor component containing a sulfur compound. Do. In the present invention, the antifogging agent is preferably kneaded into the plastic film from the viewpoint of the antifogging effect and durability. The anti-fogging agent may be any one having safety for use in plastic films for maintaining the freshness of fresh products, such as glycerin fatty acid ester, diglycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, polyethylene glycol fatty acid ester Etc.

Glycerin fatty acid ester refers to monoglycerin fatty acid ester. The glycerin fatty acid ester includes glycerin monofatty acid ester, glycerin difatty acid ester and the like, and in any case, it is at least one selected from the group consisting of saturated fatty acid having 10 to 20 carbon atoms and glycerin ester of unsaturated fatty acid. Compounds of the class are preferred, and include, for example, glycerin mono or dilaurate, glycerin mono or dipalmitate, glycerin mono or distearate, glycerin mono or dioleate.
As the glycerin fatty acid ester, glycerin monofatty acid ester is particularly preferable, glycerin monounsaturated fatty acid ester is particularly preferable, and glycerin monooleate is most preferable.

The diglycerin fatty acid ester is preferably at least one compound selected from the group consisting of saturated fatty acid having 10 or more and 20 or less carbon atoms and diglycerin ester of unsaturated fatty acid, for example, mono, di, tri of diglycerin Or tetra fatty acid esters. Specific compounds include diglycerin laurate, diglycerin palmitate, diglycerin stearate, and diglycerin oleate.
As the diglycerin fatty acid ester, diglycerin monofatty acid ester is particularly preferable, and diglycerin monosaturated fatty acid ester having a carbon number of 10 or more and 20 or less of saturated fatty acid is more preferable, and diglycerin monolaurate is preferable among these.

  The sorbitan fatty acid ester is preferably a sorbitan ester of a saturated or unsaturated fatty acid having 10 to 20 carbon atoms. Specific examples include sorbitan laurate, sorbitan myristate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan linoleate and the like.

The polyethylene glycol fatty acid ester is preferably at least one compound selected from the group consisting of saturated fatty acid having 10 or more and 20 or less carbon atoms and polyethylene glycol ester of unsaturated fatty acid.
As this specific compound, for example, polyethylene glycol decanate, polyethylene glycol laurate, polyethylene glycol myristilinate, polyethylene glycol palmitate, polyethylene glycol stearate, polyethylene glycol oleate and the like can be mentioned. Furthermore, the form of the ester may be any of monoester and diester.
It is preferably polyethylene glycol monofatty acid ester, particularly preferably polyethylene glycol monofatty acid ester of saturated fatty acid having 10 to 20 carbon atoms, and most preferably polyethylene glycol monolaurate.

  In particular, at least one of glycerin fatty acid ester, diglycerin fatty acid ester and polyethylene glycol fatty acid ester is preferably used as the antifogging agent from the viewpoint of processability and antifogging effect, and particularly glycerin fatty acid ester and / or diglycerin fatty acid It is preferable to use an ester and a polyethylene glycol fatty acid ester in combination in view of the balance of the antifogging effect due to the difference in processability, bleeding property and antifogging performance. When glycerin fatty acid ester and / or diglycerin fatty acid ester and polyethylene glycol fatty acid ester are used in combination, the mass ratio of the former to the latter is preferably 1.0: 0.1 to 0.3.

  It is most preferable to use a combination of glycerin fatty acid ester, diglycerin saturated fatty acid ester and polyethylene glycol fatty acid ester as the antifogging agent. In this case, the mass ratio of the glycerin fatty acid ester to the diglycerin fatty acid ester is preferably 1.0: 0.5 to 2.0 in the mass ratio of the former: the latter.

  The amount of the antifogging agent is preferably 0.2 parts by mass or more with respect to 100 parts by mass of the resin in terms of enhancing the freshness maintaining effect by combining the zeolite and the inorganic deodorant. Further, the amount of the antifogging agent is preferably 0.6 parts by mass or less with respect to 100 parts by mass of the resin in view of manufacturing cost, processability, and ease of packaging, and 0.4 parts by mass or less It is more preferable to do.

(Other ingredients)
The plastic film of the present invention may contain other components other than the zeolite, the inorganic deodorant and the antifogging agent. Examples of other components include coloring agents, inorganic fillers, organic fillers, ultraviolet light absorbers, light stabilizers, antioxidants, hydrolysis inhibitors, antistatic agents, plasticizers, and lubricants. . The content of these other components is not particularly limited, and can be appropriately determined within the range that does not impair the desired physical properties of the present film, but is preferably based on 100 parts by mass of the resin. The amount is preferably 5 parts by mass or less from the viewpoint of exhibiting the effects of maintaining the freshness and deodorizing more effectively, and particularly preferably 3 parts by mass or less.

(Plastic film)
The plastic film of the present invention can be obtained by molding a resin composition obtained by mixing the above-mentioned resin, zeolite, inorganic deodorant, antifogging agent and other components which are optionally added. it can.
In mixing, it is preferable from the viewpoint of processability and processing environment to add zeolite, an inorganic deodorant and an antifogging agent after making them into a masterbatch.
Moreover, it is preferable to mix using a measurement type mixer from the point of prevention of mixing nonuniformity, and supplyability of a stable mixture.
The method for molding the plastic film of the present invention from the resin composition is not particularly limited. For example, a known appropriate method such as an extrusion casting method using a T-die or an inflation method may be adopted. In particular, it is preferable to use the air-cooling inflation method from the viewpoint of processability and proper bag-making. The air-cooling inflation method is a method in which a melt tube extruded from a die is expanded by an air pressure inside using an inflation die, and the melt film is fixed by air cooling. The blowing direction of the film may be upward, horizontal or downward.
There are no particular limitations on the specifications and molding conditions of the inflation molding machine, and conventionally known methods and conditions can be adopted. For example, the bore diameter of the extruder is 50 to 100 mm in diameter, and the ratio L / D of the bore diameter D and the length L from the bottom of the hopper to the tip of the cylinder is 25 to 30.
The die has a shape generally used for inflation molding, and has, for example, a channel shape such as a spider type, a spiral type, or a stacking type, and has a diameter of 75 to 300 mm.
As molding conditions, the temperature of the resin extruded from the die is in the range of 170 to 200 ° C., and the average take-up speed determined by the discharge amount and the die shape is 5 mm / min to 30 m / min. The bubble that has exited the die is expanded by the gas inside, and may be molded under molding conditions such that the blow ratio represented by the ratio of the bubble diameter to the die aperture is in the range of 1.5 to 4.0. it can. The bubble is cooled and solidified, and the frost line height from the exit of the die to the solidification of the bubble varies depending on the film forming speed and the film thickness, but is in the range of 100 to 1000 mm.

  The thickness of the film of the present invention is preferably 15 μm or more and 50 μm or less. By setting the thickness of the film to 20 μm or more, the film strength can be made sufficient as a perishables packaging material. When the thickness of the film is 40 μm or less, there are advantages of cost and moisture permeability. From this viewpoint, the thickness of the film is more preferably 20 μm or more and 40 μm or less.

  The film of the present invention may be a single layer film or may be formed by laminating a plurality of films. When the film of the present invention comprises multiple layers of films, each layer may contain a resin, a zeolite, an inorganic deodorant and an antifogging agent, or a resin, a zeolite, an inorganic deodorant and The film which does not contain any or all of the resin, the zeolite, the inorganic deodorant and the antifogging agent in the present invention may be laminated on a single layer film containing the antifogging agent. When the film of the present invention is composed of a multilayer film, it is preferable that the total thickness thereof satisfy the above-mentioned preferred thickness range.

  The plastic film of the present invention may have pores for the purpose of controlling the respiration of fresh products, particularly fruits and vegetables. Examples of such a hole include those described in JP-A-4-125698. On the other hand, the plastic film of the present invention may be non-porous. When the plastic film is non-porous, it is possible to prevent weight loss associated with water evaporation. The non-porous plastic film means that one or more through holes are not provided. In addition, the through-hole as used in the field of this invention refers to what was provided intentionally, and the pinhole etc. which were provided unavoidable in a manufacturing process etc. are not included.

The plastic film of the present invention is preferably used as a packaging material in that it can effectively exhibit the deodorizing and freshness maintaining effects of its perishables.
It is preferable that the packaging material has a bag-like shape in terms of the ease of packaging fresh products. When the present invention is used as a packaging material, and the packaging material comprises a laminate of a plurality of layers, the film of the present invention containing a resin, a zeolite, an inorganic deodorant and an antifogging agent is at least plural. Among the layers, it is preferable to constitute the innermost layer located on the package side.

  As a use of a packaging material, the thing for packaging of perishable goods is mentioned preferably. As fresh produce, fruits and vegetables can be mentioned without limitation. The packaging material of the present invention is preferably used particularly for packaging of fruits and vegetables because it can effectively exhibit its deodorizing and freshness maintaining effects. Fruits and vegetables include, for example, vegetables, grains, fruits, beans, mushrooms, flowers and seedlings. The packaging material of the present invention is particularly preferably used for packaging fresh food.

Vegetables include root vegetables such as radish, carrot, potato, sweet potato, yam, lotus root, yam, burdock, onion lily, lily of the valley;
Mustard, cabbage, watercress, kale (hagoromokanran), komatsuna, saishin, sangchu, santoki, shunkyiku, shirona, seri, celery, taisai, radishona (Japanese radish), Japanese mustard spinach, Chinese cabbage, Chinese cabbage, Chinese cabbage, Chinese cabbage, parsley, Haruna, swiss chard (swiss chard), spinach, mizuna, mibunka, honeybee, meka cabbage, ruccola, lettuce (chisha), wankabi, wasabina, chopsticks, asparagus, udo, kohlrabi, sasai, bamboo shoots, garlic, hydrangea, green onions , Scallions, onions, artichokes, broccoli, cauliflower, edible chrysanthemums, nabasas, fukinotou, myoga etc.
Fruits such as eggplant, pepino, tomato, pepper, peppercorn, pepper, pumpkin, zucchini, cucumber, Tsunonigauri (Kiwano), Shirouri, Tsurureishi (Goya, Bittersweet), Tougan, Hachima, Okra, etc .;
Green bean sprouts, soybean sprouts, sprouts such as sweet potato; and the like.

Examples of cereals include corn, rice and wheat.
Fruits include banana, mango, plum, apple, strawberry, orange, grape, Japanese pear, pear and the like.
Examples of mushrooms include fungal fungi such as shiitake, shimeji, eryngii, maitake and matsutake.
Examples of flowers and trees include flowering plants such as chrysanthemum, lily and carnation.

  In particular, in the present invention, it is preferable to be used for maintaining the freshness of fruits and vegetables that generate an odor component containing a sulfur-based compound, from the viewpoint of effectively exerting the deodorizing and freshness holding effect of the packaging material of the present invention. Such fruits and vegetables include, among the above, cruciferous plants. Examples of sulfur-based compounds include methyl mercaptan, dimethyl disulfide, hydrogen sulfide and the like. It does not specifically limit as a site where fruits and vegetables are packaged, and any one or two or more species such as leaves, stems, shoots, flower buds, flowers, seeds, fruits, roots, rhizomes, florets, buds, etc. may be mentioned. It may be the whole body.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the present invention is not limited to such embodiments. In the following, “parts” means “parts by mass”, and “%” means “mass%”.

Example 1
Linear low density polyethylene (LLDPE, DOW2645.11G manufactured by Dow Chemical, d = 0.921 g / cm ³ , MI = 0.9) 80 parts, low density polyethylene (LDPE, Ube Maruzen Polyethylene Corporation F022 NH, d = As a zeolite, 5 parts of PEX 506 (synthetic zeolite, master batch containing 30% of sodium type aluminosilicate (matrix resin: LDPE)) as a zeolite relative to 20 parts of 0.922 g / cm ³ , MI = 0.8) 2 parts of Kessmon NS-20C (master batch containing 20% copper-containing metal silicate (matrix resin: LDPE)) manufactured by Toagosei Co., Ltd. as an inorganic deodorant, GMO (glycerin monooleate as an antifogging agent ): DGML (diglycerin monolaurate): PEGML (polyethylene glycol Monolaurate) the mass ratio of 50:40:10 mixture of 13% containing master batch (matrix resin: LDPE) 3 parts were added, respectively, by mixer, at room temperature, and homogeneously mixed. The obtained resin mixture is extruded at a molding temperature of 180 ° C. using an annular die inflation film forming machine (die diameter: 180 mmφ), and film forming is performed under the condition of blow ratio 2.76 (film width: 780 mm). A 30 μm non-porous tube base fabric was produced. The tube was formed into a bag by a heat sealing machine to form a packaging bag having an inner dimension of 600 mm in length and 780 mm in width (the inner surface area is twice the longitudinal length × lateral length).

(Comparative example 1)
A packaging bag was obtained in the same manner as in Example 1 except that none of zeolite, inorganic deodorant and antifogging agent was used.

(Comparative example 2)
A packaging bag was prepared in the same manner as in Example 1 except that an antibacterial agent (Novalon MZE1100 manufactured by Toagosei Co., Ltd., a master batch containing 10% of silver ion supported zirconium (matrix resin: LDPE)) was added instead of zeolite. Obtained.

[Evaluation 1]
The harvested broccoli (bud inflorescence and stem) was placed on each of the packaging bags of Example 1 and Comparative Examples 1 and 2 three days each on the harvest day, and the opening of the bag was folded and sealed, respectively. I put it and sealed it with kraft tape.
These packaging bags were stored in a 5 ° C. ± 4 ° C. (winter season) environment, and evaluated on the third day, the fifth day, the eighth day, and the tenth day from the start of storage according to the following method. Broccoli after storage was evaluated by the following method. The evaluation results are shown in Table 1.

(1) Appearance change of broccoli The broccoli flower buds (portion where the buds are collected) after storage were visually confirmed, and the appearance change was evaluated from the yellowing condition of the bud.
:: There is no yellowing, no melting point, and all green color is maintained.
X: Yellowish and crucible is present.

(2) Change in odor in the bag The packaging bag after storage was opened, and the odor was evaluated according to the following evaluation criteria.
○: No offensive odor is felt at all.
X: Sulfur smell or rot smell is felt.

(3) Changes in Taste The broccoli after storage was fed and evaluated based on the following evaluation criteria in comparison with broccoli immediately after harvest.
Good: Has the same taste as broccoli immediately after harvest.
X: The taste is reduced compared to broccoli immediately after harvest.

  From the results of Table 1, it can be seen that the plastic film of the present invention containing an inorganic deodorant other than a resin, zeolite, and zeolite and an antifogging agent exhibits excellent effects in maintaining freshness and deodorizing fresh products.

(Comparative example 3)
A packaging bag was obtained in the same manner as in Example 1 except that the zeolite and the antifogging agent were not added.

(Comparative example 4)
A packaging bag was obtained in the same manner as in Example 1 except that the inorganic deodorant and the antifogging agent were not added.

(Comparative example 5)
A packaging bag was obtained in the same manner as in Example 1 except that the zeolite, the inorganic deodorant and the antifogging agent were not added.

(Comparative example 6)
A packaging bag of PP bag (perforated type) was used.

[Evaluation 2]
10 to 12 strains of harvested broccoli (bud inflorescence and stem) were packed in each of the packaging bags of Example 1 and Comparative Examples 3 to 6 on the harvest day, and those sealed with vinyl tape were placed in cardboard respectively Sealed with kraft tape.
These packaging bags were stored at 20 ° C. for 0 days, at 20 ° C. for 4 days, and at 20 ° C. for 7 days. The cardboard was covered with a black film and stored in consideration of the influence of light incident from the window. Broccoli after storage was evaluated by the following method. The evaluation results are shown in Table 2.

(1) Appearance change of broccoli The broccoli flower buds (portion where the buds are collected) after storage were visually confirmed, and the appearance change was evaluated from the yellowing condition of the bud.
◎: There is no yellowing, no melting point, and all green color is maintained.
○: More than half of the strains are yellowing and show melting pot.
X: Yellowish and crucible found in all stocks.

(2) Change in odor in the bag The packaging bag after storage was opened, and the odor was evaluated according to the following evaluation criteria.
◎: No offensive odor is felt at all.
○: I feel a sulfur smell.
X: Sulfur smell and rot smell are felt.

(3) Analysis of total sugar and vitamin C content Three samples having a lot of buds from each packaging bag were selected, and analysis of total sugar and vitamin C content was performed using a sample obtained by cutting the bud with a slicer.

From the results of Table 2, the plastic film of the present invention containing resin, zeolite, inorganic deodorant other than zeolite and anti-fogging agent is further more effective to exert excellent effects on freshness retention and deodorization of fresh products. it is obvious.

Claims (10)

  A plastic film for maintaining freshness, which contains a resin, zeolite, an inorganic deodorant other than zeolite, and an antifogging agent.   The plastic film according to claim 1, wherein the inorganic deodorant is an inorganic deodorant for sulfur-based gas.   The plastic film according to claim 1 or 2, wherein the resin comprises a polyolefin.   The plastic film according to claim 3, wherein the resin comprises polyethylene.   The plastic film according to claim 4, wherein the resin comprises LLDPE and LDPE.   The plastic film according to any one of claims 1 to 5, wherein the inorganic deodorant is a metal silicate containing copper.   The antifogging agent is at least one selected from GMO (glycerin monooleate), DGML (diglycerin monolaurate), and PEGML (polyethylene glycol monolaurate). The plastic film described in.   A packaging material comprising the plastic film according to any one of claims 1 to 7.   The packaging material according to claim 8, which is in the form of a bag. The packaging material of Claim 8 or 9 used for the freshness preservation of the fruit and vegetables which generate | occur | produce the odor component containing a sulfur-type compound.