JP2008265833A - Miso packaging materials - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miso packaging material which enables the polyamide film of a substrate layer, a primer layer, a deposited layer, a protection coat layer, a printing layer, and a heat seal layer to overlie in sequence and is excellent in gas barrier property and pressure resistance and is excellent in anti-pinhole property, sticking resistance, impact resistance, loading resistance or the like when formed into a bag shape and does not cause air pollution due to generation or the like of dioxin and chlorine gas when burned. <P>SOLUTION: The miso packaging material includes a laminated body where the primer layer, a thin film layer, and the protection coat layer overlie in sequence at least one face of a substrate consisting of transparent oriented polyamide film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a miso packaging material having a gas barrier property using a polyamide film as a base material.

  In recent years, the packaging form of food and the like has also changed significantly. In addition, the deterioration of product quality due to the influence of temperature change, moisture, oxygen, etc. in the distribution and sales process has become a major problem not only in terms of sales loss but also in terms of food hygiene.

  Under the circumstances described above, there is an increasing demand for packaging films that have low gas and moisture permeability and do not cause quality degradation as food.

  That is, it is important to maintain the taste and freshness by suppressing the oxidation and alteration of proteins, fats and oils of food ingredients. For this reason, it is desired to block the permeation of air using a packaging material having a good gas barrier property.

  And if it wraps with a gas barrier film, the aroma of a content will be hold | maintained and the permeation | transmission of a water | moisture content will also be blocked | prevented. Moreover, moisture absorption deterioration is suppressed in the dried product. Furthermore, in the case of a hydrated product, alteration and solidification due to volatilization of moisture are suppressed, and it becomes possible to maintain a fresh flavor during packaging for a long time.

  A packaging material using a metal foil made of a metal such as aluminum as a gas barrier packaging material is excellent in gas barrier properties, but must be treated as a non-combustible material when discarded after use.

  Furthermore, since the packaging material using metal foil cannot be seen through the packaging material, it is difficult to confirm the sealing failure at the time of filling and sealing, and the detection of foreign matter by the metal detector There are problems such as not being able to.

  Further, coating with vinylidene chloride or the like as a gas barrier layer is inexpensive and economical, but does not have sufficient gas barrier properties against water vapor, oxygen, and the like. Further, vinylidene chloride has a problem of air pollution due to generation of dioxin and chlorine gas at the time of incineration.

  In particular, miso is significantly promoted to turn brown by oxygen. In addition, high barrier properties are required because of problems such as quality degradation due to the aroma dispersion of miso and the transfer of odors to other products.

In addition, as a packaging material for miso, an ethylene vinyl alcohol copolymer (EVOH) film, a polyvinyl alcohol (PVA) film or a sheet laminated with a film coated with polyvinylidene chloride (PVDC) has been generally used. there were. (For example, see Non-Patent Document 1)
Prior art documents are shown below.
"Functional and Food Packaging Technology Handbook" Published by Science Forum, Inc. 1989 (76-92 pages)

  However, these films have a reduced oxygen barrier under high temperature and high humidity. For this reason, the color change is remarkable, and the expiration date is set short in consideration of the temperature and humidity in summer.

  On the other hand, as a so-called dechlorination and dealumination gas barrier packaging material that does not use vinylidene chloride, aluminum metal foil, etc., a vapor deposition film in which a vapor deposition thin film made of an inorganic oxide is formed on a plastic substrate has come to be frequently used. .

  However, since vapor deposition onto a polyamide film has a lower glass transition point and is softer than a polyester film, there is a problem that it is difficult to form a hard vapor deposition layer uniformly, and barrier properties are difficult to develop.

  Furthermore, the miso packaging material must have puncture resistance, impact resistance, and pinhole resistance in addition to gas barrier properties. For this reason, the polyamide-type film excellent in these physical properties is used rather than the polyester-type film. And, with a polyamide-based vapor deposition barrier film, a packaging material for miso that can maintain a long shelf life cannot be realized.

  This invention is made | formed in view of the said conventional problem, The place made into the subject is providing the packaging material for miso which used the polyamide-type film excellent in gas barrier property as a base material.

In order to solve the above problems, the invention according to claim 1 of the present invention provides:
A primer layer, a thin film layer, and a protective coating layer on at least one surface of a substrate made of a transparent stretched polyamide film;
It is a packaging material for miso which consists of the laminated body which laminated | stacked one by one.

Next, the invention according to claim 2 of the present invention is as follows:
The packaging material for miso according to claim 1, wherein a printing layer and / or a heat seal layer is provided on the protective coating layer.

  Since the miso packaging material of the present invention has the above configuration, it is excellent in gas barrier properties and pressure resistance. And when used as a packaging material for miso, it has excellent pinhole resistance, no puncture or impact resistance, load breakage, etc., and air pollution due to generation of dioxins and chlorine gas during incineration The problem does not occur.

  Moreover, when the packaging material for miso of this invention is used as a packaging material for miso, even if it preserve | saves for a long time, there is little discoloration of miso. Furthermore, it is excellent in aroma retention.

  The miso packaging material of the present invention will be described in detail below along the embodiments with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a cross section of one embodiment of the miso packaging material of the present invention.

  As shown in FIG. 1, the packaging material for miso of this example is a polyamide film (1) that is a base material layer, a primer layer (2), a vapor deposition layer (3), a protective coating layer (4), The print layer (5) and the heat seal layer (6) are sequentially laminated.

  Moreover, since the miso packaging material requires puncture resistance, impact resistance, and pinhole resistance, a polyamide film is used.

  The polyamide film (1) as the base material layer is made of a nylon resin that is excellent in flexibility among plastic materials, and a stretched transparent film is good. For example, nylon 6 obtained by ring-opening polymerization reaction of ε-caprolactam, nylon 66 obtained by condensation polymerization reaction of hexamethylenediamine and adipate, MXD6 nylon obtained by condensation polymerization of metaxylenediamine and adipic acid, A general-purpose single layer film made of nylon 11, nylon 12, or the like is used.

  The stretching method may be a biaxial stretching method or a sequential stretching method. The thickness is preferably in the range of 12 to 25 μm from the viewpoint of film formability and economic efficiency.

  Further, when forming the polyamide film (1) as the base material layer, various additives and stabilizers, for example, an antistatic agent, an ultraviolet ray preventing agent, a plasticizer, a lubricant and the like may be used. The surface may be subjected to corona treatment, low temperature plasma treatment, ion bombardment treatment as a pretreatment, and may further be subjected to chemical treatment, solvent treatment, and the like.

  Moreover, when the easy-adhesion layer is provided in the single side | surface or both surfaces of the polyamide film (1) which is a base material layer, adhesiveness with a primer layer will improve. For this reason, when used in a container having a shape or structure to which more physical stress is applied, or when the contents are heavy, it is desirable that there is easy adhesion.

  Next, the primer layer (2) will be described. The primer layer (2) is provided for the purpose of improving the adhesion between the polyamide film (1), which is a base material layer, and the thin film layer (3), and suppressing a decrease in laminate strength due to the influence of the contents. Yes.

  As the primer resin for forming the primer layer (2), any resin material can be used as long as it can improve the adhesion between the polyamide film (1) as the base material layer and the thin film layer (3). And it is preferable that it is a polyester resin single-piece | unit or a mixture of this resin and 1 or more types of mixed resin chosen from an isocyanate resin, an epoxy resin, and a melamine resin. In particular, in the composition containing these resins as the above-mentioned resin, the polyamide film (1) and the thin film layer (3) as the base material layer are firmly bonded by the reaction of the functional group of each resin. Can be made.

  Moreover, it is desirable to coat the primer layer (2) so that the thickness after drying is generally in the range of 0.005 to 5 μm, and more preferably in the range of 0.01 to 1 μm. . And in the case of 0.01 micrometer or less, it is difficult to obtain a uniform coating film from the point of coating technology. Conversely, if it exceeds 1 μm, it is uneconomical.

  Furthermore, the vapor deposition layer (3) made of an inorganic compound is made of oxides such as silicon, aluminum, titanium, zirconium, tin, and magnesium, nitrogen, fluoride units, or a composite thereof. And it forms by vacuum processes, such as a vacuum evaporation method, sputtering method, and a plasma vapor phase growth method.

  In particular, aluminum oxide is colorless and transparent and excellent in boiling sterilization and heat / pressure sterilization, and can be used for a wide range of applications. The film thickness of the vapor deposition layer (3) varies depending on the application, but is preferably in the range of several tens to 5,000 mm. And if it is 50 mm or less, there is a problem in the continuity of the thin film. Moreover, since it will be easy to generate | occur | produce a crack when it exceeds 3000 cm and a flexibility falls, Preferably it is 50-3000 mm.

  Furthermore, a protective layer for the thin film layer (3) can be formed on the thin film layer (3) as required. Further, since the thin film layer (3) is an extremely thin film, it is relatively easily damaged by physical stimulation such as rubbing. And depending on the case, there exists a possibility that it may fall from the polyamide film (1) which is a base material layer. Therefore, it is meaningful to form a protective layer after forming the thin film layer (3) and before performing other processing.

  What is necessary is just to form arbitrary resin by methods, such as coating, as said protective layer. For example, the protective layer can be formed by forming a coating agent mainly composed of a water-soluble polymer such as polyvinyl alcohol on the thin film layer (3).

The protective coating layer (4) of this example is composed of Si (OR ¹ ) ₄ and R ² Si (OR ³ ) ₃ (R ¹ and R ² are CH ₃ , C ₂ H ₅ , C ₂ H ₄ OCH _3, etc. A high gas barrier is formed by applying a solution in which a silicon compound represented by a hydrolyzable group, R ² is an organic functional group) or a hydrolyzate thereof, and a water-soluble polymer having a hydroxyl group and drying by heating. It is preferable because of its good properties and good adhesion.

  The protective coating layer (4) is made of a silane coupling agent, an isocyanate compound, colloidal silica, smectite or other clay in consideration of water resistance, ink, adhesiveness with an adhesive, wettability, and prevention of cracking due to shrinkage. Known additives such as minerals, stabilizers, colorants, viscosity modifiers, and the like can also be added.

  Moreover, a printing layer (5) can also be provided on a protective coat layer (4). The printed layer (5) is formed for practical use as a packaging bag or the like. Additives such as various pigments, extender pigments, plasticizers, desiccants, stabilizers, etc. to conventionally used ink binder resins such as urethane, acrylic, nitrocellulose, rubber and vinyl chloride It is a layer composed of added ink, and characters, patterns, etc. are formed.

  As a forming method for forming the printing layer (5), for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known application such as a roll coat, a knife edge coat, or a gravure coat. A scheme can be used. And the thickness of the said printing layer (5) may be 0.1-2.0 micrometers.

  Moreover, when using the packaging material for miso of this invention as a packaging material, it is preferable to form the heat seal layer (6) which consists of a polyolefin-type thermoplastic resin in the side used as the innermost layer of a packaging material.

  In addition to forming the polyolefin-based thermoplastic resin on the thin film layer (3), an intermediate layer can be provided as necessary. The intermediate layer is provided to further functionalize the packaging material, such as imparting tearability and increasing the waist strength of the packaging material. Any material can be selected and used according to the consumer's requirements, the suitability of the contents, and the like.

  For example, when imparting tearability, a uniaxially stretched nylon film, a uniaxially stretched polyethylene terephthalate film, a uniaxially stretched polypropylene film, or the like can be used. In order to increase the waist strength, plastic materials such as a biaxially stretched polyethylene terephthalate film and a biaxially stretched polypropylene film can be used.

  The thickness of the intermediate layer is appropriately selected according to the material, required quality, required physical properties, etc., but is generally in the range of 10 to 30 μm.

  In addition, as a method for forming the intermediate layer, a known method such as a dry laminating method in which an adhesive such as a two-component curable urethane resin is bonded or an extrusion laminating method in which a heat-melted resin is extruded and bonded in a curtain shape is used. It can laminate | stack by using a method. In general, a dry lamination method is often used.

  Moreover, a polyethylene-type thermoplastic resin layer is utilized for the adhesion part at the time of forming a packaging material in a bag shape. Examples of the resin of the polyethylene-based thermoplastic resin layer include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, and ethylene-acrylic acid copolymer. Further, resins such as ethylene-acrylic acid ester copolymers and their metal cross-linked products are used.

  The thickness is appropriately selected according to the purpose, but is generally in the range of 15 to 200 μm.

  Moreover, as the formation method, the film-like thing which consists of said resin is laminated | stacked by the dry lamination method which bonds together using adhesives, such as a two-component curable urethane resin, and the method of laminating | stacking by a non-solvent lamination. Alternatively, the resin can be laminated by a known method such as an extrusion laminating method or a knee laminating method in which the resin is heated and melted and extruded into a curtain shape.

  Moreover, although not shown in the drawing, a laminate of a plurality of resins can be formed on the opposite surface of the stretched polyamide film 1 as a base material via a printing layer, a heat seal layer, and an adhesive.

  Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto.

At the time of implementation, the protective coating solution used was hydrolyzed with a solid content of 3 wt% (in terms of SiO ₂ ) obtained by adding 89.6 g of hydrochloric acid (0.1N) to 10.4 g of tetraethoxysilane and stirring for 30 minutes. Solution (liquid A). A 3 wt% water / isopropyl alcohol solution of polyvinyl alcohol (water: isopropyl alcohol in a weight ratio of 90:10) (liquid B). A mixture of liquid A and liquid B at a mixing ratio (wt%) of 60/40.

<Example 1>
As a base material layer, a biaxially stretched nylon film (Unitika Ltd., Emblem ONM) having a thickness of 15 μm and subjected to corona treatment on one side is used, and a corona treatment surface is made of a polyester resin and an isocyanate compound using a gravure coating machine. A primer layer having a thickness of about 0.1 μm was laminated.

  Next, the vapor deposition layer which consists of aluminum oxide with a thickness of 12 nm was laminated | stacked with the vacuum evaporation system. Furthermore, the protective coating liquid which apply | coated the protective coating liquid on the vapor deposition layer again with the gravure coater, and laminated | stacked the protective coating layer which consists of a dry film with a thickness of 0.2 micrometer was laminated | stacked, and the polyamide film laminated body was produced.

  Furthermore, after laminating a printing ink layer by gravure printing, the ink composition is provided with a two-component curable urethane adhesive by gravure coating on the printing ink layer by a dry laminating method. The film used for the packaging material for miso was produced by laminating an ethylene / vinyl acetate copolymer having a thickness of 50 μm to form a heat seal layer.

<Example 2>
In Example 1, 5 w of silane coupling agent was added to the protective coating solution with respect to the total solid content.
The film used for the packaging material for miso was produced like Example 1 except having added%.

<Comparative Example 1>
In Example 1, a film used for a packaging material for miso was prepared in the same manner as in Example 1 except that a vinylidene chloride coated nylon film having a thickness of 15 μm was used instead of the polyamide film laminate.

<Evaluation 1>
The oxygen permeability of the films produced in Examples 1-2 and Comparative Example 1 was measured. Based on JIS-7126B, it measured with the oxygen permeability measuring apparatus ("OX-TRAN 10 / 50A" Modern Controls company make) in the environment of temperature 30 degreeC and humidity 70% RH.

<Evaluation 2>
Moreover, using the films obtained in Examples 1 and 2 and Comparative Example 1, a 10 cm square four-side sealed notched bag was prepared and filled with 20 g of commercially available miso as a content. The pouch containing miso was stored in an environment of 30 ° C. and 90% RH for 2 weeks, and the color change was visually confirmed. A sample having almost no change in color compared with that before storage was marked with ◯, and a sample with brown color was marked with ×.

<Evaluation 3>
Further, the miso-containing sachet prepared in Evaluation 2 was put in a glass bottle with a lid, sealed, stored at 30 ° C. for 2 weeks, and the odor in the glass bottle was subjected to a sensory test. The odorless product was marked with ○, and the one with a miso scent was marked with ×.

<Evaluation results>
The evaluation results of Examples 1 and 2 and Comparative Example 1 are shown in Table 1.

<Comprehensive evaluation>
As shown in Table 1, Examples 1 and 2 have higher barrier properties than the vinylidene chloride coated film of Comparative Example 1, the color change was suppressed even under storage at 30 ° C. and 90% RH, and the fragrance retention was also good. . Further, Examples 1 and 2 did not generate chlorine gas.

It is sectional drawing which shows the cross section of one Example of a structure of the packaging material for miso of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Polyamide film which is a base material layer 2 ... Primer layer 3 ... Deposition layer 4 ... Protective coating layer 5 ... Printing layer 6 ... Heat seal layer

Claims (2)

A primer layer, a thin film layer, and a protective coating layer on at least one surface of a substrate made of a transparent stretched polyamide film;
A packaging material for miso, which is made of a laminate in which layers are laminated in sequence. The packaging material for miso according to claim 1, wherein a printing layer and / or a heat seal layer is provided on the protective coating layer.

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