JPH08267638A - Packaging material provided with printing layer with excellent barrier property - Google Patents

Abstract

PURPOSE: To provide a flexible packaging material with excellent gas barrier properties to oxygen and steam and with less decrease in the gas barrier properties even when a printing layer is provided directly on a deposit film. CONSTITUTION: A packaging material with excellent barrier properties provided with a printing layer is prepd. by providing the printing layer 5 on a coating layer 4 of a barrier material 1 in which an inorg. compd. deposited layer 3, and the coating layer 4 contg. a water-soluble polymer and a metal alkoxide or its hydrolyzate is provided successively on a base material 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved vapor-deposited film provided with a vapor-deposited layer of an inorganic compound such as silicon oxide and aluminum oxide. Even if a print layer is directly provided on the vapor-deposited film, the gas barrier property is less deteriorated. It concerns packaging materials.

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods, pharmaceuticals, etc. are used to suppress deterioration of contents, particularly oxidation and deterioration of proteins, fats and oils in foods, and to maintain taste and freshness. In addition, in order to suppress the deterioration of the active ingredient and maintain its efficacy in pharmaceuticals that require aseptic handling, the effects of oxygen, water vapor, and other gases that change the contents of the packaging material are prevented. It is necessary to provide a gas barrier property for blocking these gases.

Therefore, polymer resin compositions such as polyvinyl alcohol (hereinafter referred to as PVA), ethylene vinyl alcohol copolymer (EVOH), polyvinylidene chloride resin (PVDC), etc., which are generally said to have relatively high gas barrier properties, have been conventionally used. Gas-barrier laminates provided by laminating or coating are generally used as packaging films.

Further, a suitable polymer resin composition (even if it is a resin which does not have a high gas barrier property by itself)
A vapor-deposited film obtained by vapor-depositing a metal such as aluminum (Al) or a metal compound, and recently, silicon monoxide (Si).
A vapor deposition film has been developed in which a silicon oxide (SiOx) thin film such as O) or a magnesium oxide (MgO) thin film is formed on a base material made of a polymer material having transparency by a forming means such as vapor deposition. These have better gas barrier properties than gas barrier materials made of polymer resin compositions and are less likely to deteriorate under high humidity, so packaging films using this gas barrier material as a packaging material have begun to be generally used. There is.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention PVA and EVO
Since the gas barrier laminate using the H-based polymer resin composition has a large temperature dependency and humidity dependency, the gas barrier property is reduced at high temperature or high humidity, and particularly the water vapor barrier property is reduced. . Further, depending on the use of packaging, the gas barrier property may be remarkably deteriorated when the boiling treatment or the retort treatment is performed.

A gas barrier laminate comprising a PVDC type polymer resin composition has a small humidity dependency,
It is difficult to realize a high gas barrier material (high gas barrier material) having an oxygen barrier property of 1 cc / m ² · day · atm or less. In addition, since the coating contains a large amount of chlorine, there is a problem in terms of waste treatment such as incineration and recycling.

Further, as described above, silicon monoxide (S
Silicon oxides such as iO), magnesium oxide (MgO)
A vapor-deposited film provided with an inorganic compound such as
The inorganic compound thin film used for the gas barrier layer lacks flexibility, is weak in rubbing and bending, and has poor adhesion to the substrate, so be careful in handling, especially printing, laminating, bag making, etc. When the packaging material is post-processed, cracks occur and the gas barrier property is significantly deteriorated.

For this reason, as shown in FIG.
In general, the print film 51 having the print layer 53 provided on the second layer and the vapor deposition film 41 having the vapor deposition layer 43 provided on the vapor deposition base material 42 are attached to each other via the adhesive layer 61 to display by printing. It was target. In addition, 71 is a sealant layer for giving a heat-sealing property to the packaging material. In addition, it has been proposed to provide a resin coating layer for printing on the surface of the vapor deposition layer so that the printing layer can be directly formed on the vapor deposition layer. However, by providing this resin coating layer, the barrier property is lowered on the contrary. There was a tendency to do so, and it was not a good method.

[0009] Therefore, the present invention is a packaging material which has flexibility and is excellent in gas barrier property against oxygen, water vapor, etc., and even if a printing layer is directly provided on the vapor deposition film, the gas barrier property is not deteriorated so much and the barrier property is excellent. The purpose is to provide.

[0010]

According to the first aspect of the present invention,
A printing layer, comprising a substrate and an inorganic compound vapor deposition layer, a barrier material in which a coating layer containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof is sequentially provided, and a printing layer is provided on the coating layer. It is a packaging material with excellent barrier properties.

A second aspect of the present invention is a coating containing a water-soluble polymer and tin chloride in place of the coating layer containing the water-soluble polymer and the metal alkoxide or a hydrolyzate thereof according to the first aspect of the invention. A packaging material having a printed layer and excellent barrier properties, which is characterized in that a layer is provided.

In the above invention, it is preferable to provide the substrate with an anchor coat layer for vapor deposition of an inorganic compound.

A sealant layer is preferably provided on the coating layer side of the barrier material via an adhesive layer. At this time, an intervening film may be provided between the coating layer and the sealant layer via an adhesive layer.

Further, it is preferable to provide an exterior material made of a plastic film on the side of the barrier material opposite to the vapor deposition layer.

[0015]

In the packaging material of the present invention, an inorganic compound vapor deposition layer, a coating layer of a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof, or a coating layer of a water-soluble polymer and tin oxide is sequentially provided on a base material, Since the printing layer is provided on this coating layer, it is possible to prevent pinholes, cracks, etc. that occur in the vapor deposition layer due to the effects of the components of the printing ink during printing and the effects of printing layer formation. it can.

As a result, even if a printing layer is directly provided on the vapor-deposited film, a packaging material having high gas barrier properties and water resistance and excellent content resistance can be obtained. Further, even if the sealant layer is directly provided on the vapor-deposited film, there is no influence of the adhesive layer such as the adhesive agent and the anchor agent, so that the gas barrier property and water resistance after molding into the container can be maintained.

[0017]

EXAMPLE An example of the present invention will be described in detail. FIG. 1 is a sectional view showing an embodiment of the packaging material of the present invention, and FIG. 2 is a sectional view showing another embodiment of the packaging material of the present invention.

In FIG. 1, 1 is a barrier material, 2 is a base material, 3 is an inorganic compound vapor deposition layer, 4 is a coating layer, 5 is a printing layer, 6 is an adhesive layer, and 7 is a sealant layer. The base material 2 is
Sheet-like or film-like ones such as polyolefin (polyethylene, polypropylene etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate etc.), polyamide (nylon-6, nylon-66 etc.), polyvinyl chloride, A plastic film or sheet usually used as a packaging material such as polyimide or a copolymer of these polymers can be used.

Known additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant and a coloring agent can be added to the base material 2, and they are appropriately added if necessary.

It is also possible to further improve the adhesion of the vapor-deposited layer by subjecting the surface (vapor-deposited surface) of the substrate 2 to surface modification such as corona treatment or anchor coat treatment.

The inorganic compound vapor deposition layer 3 is made of oxides, nitrides, etc. of silicon, aluminum, titanium, zirconium, tin, etc.
Consists of a simple substance of fluoride or a compound thereof, and it is vacuum vapor deposition method, sputtering method, plasma vapor deposition method (CV).
It is formed by a vacuum process such as the D method).

The thickness of the inorganic compound vapor deposition layer 3 depends on the application and the second.
Depending on the thickness of the layer (coating layer), several tens of Å to 50
A range of 00Å is desirable. However, if it is 50 Å or less, there is a problem in the continuity of the thin film, and if it exceeds 3000 Å, cracks are likely to occur and flexibility is lowered, so that it is preferably 50 to 3000 Å.

The coating layer 4 is composed mainly of an aqueous solution containing a water-soluble polymer and (a) at least one metal alkoxide and its hydrolyzate or (b) tin chloride, or a water / alcohol mixed solution. And a coating agent. Water-soluble polymer and tin chloride are water-based (water or water /
Alcohol mixture) A solution obtained by dissolving in a solvent or a solution obtained by mixing a solution obtained by directly or previously hydrolyzing a metal alkoxide is coated on the inorganic compound vapor deposition layer 3 on the plastic substrate 2, It is formed by heating and drying. Each component contained in the coating agent will be described in detail below.

Examples of the water-soluble polymer used in the coating agent in the present invention include polyvinyl alcohol, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like. Particularly, when polyvinyl alcohol (PVA) is used as a coating agent for the gas barrier laminate of the present invention, the gas barrier property is most excellent. The PVA referred to here is generally obtained by saponifying polyvinyl acetate, and ranges from so-called partially saponified PVA in which acetic acid groups remain in several tens of percent to completely saponified PVA in which only several percent acetic acid groups remain. Including,
It is not particularly limited.

Further, tin chloride is stannous chloride (SnC).
l ₂ ), stannic chloride (SnCl ₄ ), or a mixture thereof, and may be an anhydride or a hydrate.

Further, the metal alkoxide is represented by a general formula such as tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxyaluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], M (OR). _n (M: Si, Ti, Ai, Zr or other metal, R: CH ₃ ,
And an alkyl group such as C ₂ H ₅ ). Of these, tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.

The above-mentioned components can be added to the coating agent singly or in combination, and the isocyanate compound, the silane coupling agent, the dispersant or the stabilizer can be added as long as the barrier property of the coating agent is not impaired. Well-known additives such as a viscosity modifier and a colorant can be added.

For example, the isocyanate compound added to the coating agent has two or more isocyanate groups (NCO groups) in its molecule. For example, tolylene diisocyanate (TDI), triphenylmethane triisocyanate (TTI), There are monomers such as tetramethyl xylene diisocyanate (TMXDI) and polymers and derivatives thereof.

As a coating method of the coating agent, conventionally known means such as a dipping method, a roll coating method, a screen printing method and a spraying method which are usually used can be used. The thickness of the film varies depending on the type of coating agent, but the thickness after drying may be in the range of about 0.01 to 100 μm, but if it is 50 μm or more, cracks tend to occur in the film, so 0.01 to 100 μm. It is desirable to set it to 50 μm.

The barrier material 1 having the above constitution is provided in one layer in the packaging material of the present invention. However, when higher barrier properties are required, the barrier material 1 may be provided in two or more layers. it can.

The present invention is characterized in that the printing layer 5 is provided on the coating layer 4 of the barrier material 1. The printing ink for forming the printing layer 5 is not particularly limited, but one using a urethane resin as a binder is preferable.

The above-mentioned barrier material 1 having the printed layer 5 formed thereon.
In general, a sealant layer 7 for imparting heat sealability to the packaging material is usually formed. As the sealant layer 7, any resin having heat-sealing property such as polyethylene, polypropylene, ethylene copolymer, and saturated polyester can be used according to the purpose. This sealant layer 7
May be provided by laminating a film material through an adhesive layer 6 made of an adhesive, or by laminating a molten resin through an adhesive layer 6 made of an anchor by extrusion coating.

In the embodiment shown in FIG. 1, the sealant layer 7 is laminated on the surface of the printing layer 5, but the present invention is not limited to this.

If necessary, another intervening film 9 may be provided between the sealant layer 7 and the coating layer 4 (printing layer 5) (see FIG. 2).

As the intervening film 9, a film having stable mechanical strength such as a stretched polyester film, a stretched polypropylene film, a stretched nylon film, or a vapor deposition film of an ethylene-vinyl alcohol copolymer or an inorganic compound, A film or the like having an excellent barrier property can be selected according to the purpose.

Further, the barrier material 1 and the sealant layer 7 are
A so-called sand laminating method of laminating via a melt-extruded adhesive resin (for example, an adhesive polyolefin such as low-density polyethylene) can be adopted. At this time, the adhesive resin functions as the interposing film 9 or the adhesive layer 6. To do.

Further, as shown in FIG. 2, an exterior material 8 made of a plastic film may be provided on the side of the barrier material 1 opposite to the vapor deposition layer 3 with an adhesive layer 6 interposed if necessary. The exterior material 8 is a film having stable mechanical strength such as a stretched polyester film, a stretched polypropylene film, and a stretched nylon film, or an ethylene-vinyl alcohol copolymer or an inorganic compound vapor-deposited like the intervening film 9 described above. A film having excellent barrier properties such as a film can be selected according to the purpose.

When the sealant layer 7 is provided on the side of the barrier material 1 opposite to the vapor deposition layer 3, the exterior material 8 is used.
Can be provided on the surface of the coating layer 4 (printing layer 5) of the barrier material 1.

The packaging material of the present invention obtained as described above has the sealant layer 7 as the inner surface, and the pillow packaging bag, 4
It can be used after being molded into a container such as a one-sided sealed bag, a three-sided sealed bag, a gusset-shaped bag, a standing pouch, and an inner bag of a bag-in-box.

Example 1 Polyethylene terephthalate (PET) having a thickness of 12 μm was used as a plastic base material, and SiO (silicon oxide) was used as a vapor deposition source on the upper surface of the plastic base material. A vapor-deposited layer was formed, a coating liquid having the following composition was applied by a bar coater, and dried by a dryer at 120 ° C. for 1 minute to form a coating layer having a thickness of about 0.5 μm.

Component of coating liquid tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] 10.
Hydrochloric acid (0.1 N) (89.6 g) was added to 4 g, and the mixture was stirred and hydrolyzed for 30 minutes to hydrolyze the solid solution having a solid content of 3 wt% (SiO ₂ conversion) (A) and 3.0 parts of polyvinyl alcohol.
A composition in which a wt% water / isopropyl alcohol (90/10) solution (B) is mixed.

Next, a two-component curing type ink (Lamister or New LP Super, both manufactured by Toyo Ink Mfg. Co., Ltd.) was applied to the coating layer surface by a gravure printing machine.
White, red and black print layers were formed separately. The oxygen permeability and water vapor permeability of the packaging material before and after the formation of each printing layer were measured. The results are shown in Table 1. The oxygen permeability was measured by the Mocon method, and the water vapor permeability was measured by the Mocon method (40 ° C., 90% RH).

[0043]

[Table 1]

<Comparative Example 1> A white printed layer was provided on the vapor deposition layer under the same structure and conditions as in Example 1 except that the coating layer of Example 1 was not provided, and the same test as in Example 1 was conducted. It was
Table 2 shows the results.

[0045]

[Table 2]

Example 2 A printed layer similar to that of Example 1 was provided with the same structure as in Example 1 except that aluminum oxide was formed as the vapor deposition layer of Example 1, and the same evaluation was performed. The results are shown in Table 3.

[0047]

[Table 3]

<Example 3> A urethane type two-component curing adhesive (A-515, manufactured by Takeda Pharmaceutical Co., Ltd.) was used on the printing layer side of the packaging material of Example 1 to reduce the thickness to 60 μm. Density polyethylene (AJ-1, manufactured by Tama Poly Co., Ltd.) was laminated by a dry lamination method to obtain a packaging material. The oxygen permeability and water vapor permeability of this packaging material were measured in the same manner as in Example 1 (before and after laminating of low density polyethylene). The results are shown in Table 4.

[0049]

[Table 4]

<Embodiment 4> A urethane-based two-component curing adhesive (A-515, manufactured by Takeda Pharmaceutical Co., Ltd.) was used on the printing layer side of the packaging material of Embodiment 2 to reduce the thickness to 60 μm. Density polyethylene (AJ-1, manufactured by Tama Poly Co., Ltd.) was laminated by a dry lamination method to obtain a packaging material. The oxygen permeability and water vapor permeability of this packaging material were measured in the same manner as in Example 1 (before and after laminating of low density polyethylene). The results are shown in Table 5.

[0051]

[Table 5]

[0052]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned constitution, compared with a packaging material in which a printing layer is directly provided on a vapor deposition layer of an inorganic compound, the deterioration of the barrier property is small, and another method for forming the printing layer is provided. It is no longer necessary to provide a film or resin layer.

Further, it becomes possible to provide an intervening film or a sealant layer on the surface of the coating layer via an adhesive layer, and the range of application to flexible packaging materials and packaging is expanded. Furthermore, since the thickness of the vapor deposition layer is thin, the time for forming the vapor deposition layer is short, the production efficiency is good, and the cost is superior.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing another embodiment of the packaging material of the present invention.

FIG. 3 is a cross-sectional view showing a conventional packaging material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Barrier material 2 ... Base material 3 ... Vapor deposition layer 4 ... Covering layer 5 ... Printing layer 6 ... Adhesive layer 7 ... Sealant layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Iwase 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (6)

[Claims] 1. A barrier material in which a substrate is provided with an inorganic compound vapor deposition layer, a coating layer containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof in this order, and a printing layer is provided on the coating layer. A packaging material having a printed layer and having an excellent barrier property. 2. A printing layer, comprising: a barrier material in which an inorganic compound vapor deposition layer and a coating layer containing a water-soluble polymer and tin chloride are sequentially provided on a substrate, and a printing layer is provided on the coating layer. A packaging material with excellent barrier properties. 3. The packaging material according to claim 1, wherein the base material has an anchor coat layer for vapor deposition of an inorganic compound. 4. A packaging material, wherein a sealant layer is provided on the coating layer side of the barrier material according to any one of claims 1 to 3 via an adhesive layer. 5. A packaging material, wherein an intervening film and a sealant layer are sequentially provided on the coating layer side of the barrier material according to any one of claims 1 to 3 with an adhesive layer interposed therebetween. 6. The packaging material according to any one of claims 1 to 5, wherein an exterior material made of a plastic film is provided on the side of the base material opposite to the vapor deposition layer.