JP2016124272A - Gas barrier laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier laminate capable of maintaining a high barrier property against water vapor, even under a high-temperature/high-humidity environment of 60°C or higher.SOLUTION: A gas barrier laminate includes, on a plastic film base material 1, at least a barrier layer 2 and a protective layer 3 sequentially laminated. The barrier layer 2 includes a reaction product of an aluminum alkoxide and a phosphorus compound. The protective layer 3 includes a reaction product of an isocyanate compound and a phosphorus compound.SELECTED DRAWING: Figure 1

Description

  The present invention provides a base material composed of a plastic film, a reaction product obtained by reacting an aluminum alkoxide formed on at least one surface of the base material and a phosphorus compound, as a barrier layer, and further an isocyanate compound on the barrier layer. The present invention relates to a gas barrier laminate in which a reaction product obtained by reaction with a phosphorus compound is used as a protective layer.

  A film containing a metal atom such as aluminum and a phosphorus atom as constituent components is conventionally known. For example, an organic polymer molded article having a gas permeation preventive coating made of a metal orthophosphate mainly composed of aluminum is known (Patent Document 1). Patent Document 1 discloses a method of forming a gas permeation preventive coating by applying a dispersion or solution of metal orthophosphate to an organic polymer molded article.

  Moreover, the composite_body | complex which consists of base materials, such as a metal, a metal alloy, and a plastic, and the coating component containing a specific aluminum phosphate compound is known (patent document 2). Patent Document 2 discloses a method of forming a coating using a solution containing an aluminum salt and a phosphate ester in an organic solvent.

  Furthermore, in order to solve the gas barrier property, particularly the resistance to hot water treatment such as retort treatment, which is the subject of the above invention, a coating layer is formed on the substrate by reacting a metal oxide such as aluminum and a phosphorus compound. A barrier film made has been invented (Patent Document 3).

JP 55-46969 A Japanese Patent No. 5117857 Japanese Patent No. 4961044

  However, the conventional barrier film that includes a metal oxide such as aluminum and a phosphorus compound in a plastic base material has voids in the film due to the properties of the film, and further has a polar group. There is a drawback that it is difficult to maintain a high barrier against water vapor in heat sterilization treatment such as retort treatment and high-temperature and high-humidity environmental tests. In particular, aluminum oxide undergoes a composition change in a high-temperature and high-humidity environment of 60 ° C. or higher, and physically becomes porous, so that the barrier property against water vapor is deteriorated. In that respect, the reaction product of aluminum alkoxide and phosphate compound can maintain the barrier property without changing chemically and physically even in a high temperature and high humidity environment of 60 ° C. or higher. Since the film has a hydroxyl group in its composition, when used for a barrier film used for foods and medical drugs, a high barrier against water vapor after processing such as retort sterilization and boiling cannot be maintained.

  An object of this invention is to provide the gas barrier laminated body which can maintain the high barrier property with respect to water vapor | steam also in the high temperature, high humidity environment of 60 degreeC or more.

The invention according to claim 1 of the present invention is a gas barrier laminate in which at least a barrier layer and a protective layer are sequentially laminated on a plastic film substrate,
The barrier layer comprises a reaction product of aluminum alkoxide and a phosphorus compound,
The protective layer is a gas barrier laminate comprising a reactive organism of an isocyanate compound and a phosphorus compound.

  In the invention according to claim 2, the composition of the protective layer is such that the atomic ratio (O / P) of oxygen and phosphorus calculated by X-ray photoelectron spectroscopy (XPS) is in the range of 2.0 to 5.0. The gas barrier laminate according to claim 1, wherein

  The invention according to claim 3 is the gas barrier laminate according to claim 1 or 2, wherein the P2p peak binding energy measured by XPS of the protective layer is in the range of 132 eV to 135 eV. .

  The invention according to claim 4 is the gas barrier laminate according to any one of claims 1 to 3, wherein the protective layer has a thickness of 3 nm to 10 nm.

  According to the first aspect of the present invention, there is provided a gas barrier laminate in which at least a barrier layer and a protective layer are sequentially laminated on a plastic film substrate, wherein the barrier layer comprises an aluminum alkoxide and a phosphorus compound. By comprising this reaction product, it is possible to impart gas barrier properties, particularly resistance to hot water treatment such as retort treatment. Further, since the protective layer is made of a reactive organism of an isocyanate compound and a phosphorus compound, it is possible to block voids and polar groups serving as a water vapor transmission path of the barrier layer, and the water vapor barrier obtained by the barrier layer alone. In addition to the property, it is possible to maintain a better barrier property.

  According to claim 2, the composition of the protective layer is such that the atomic ratio (O / P) of oxygen and phosphorus calculated by X-ray photoelectron spectroscopy (XPS) is in the range of 2.0 to 5.0. By being, it can block | interrupt the space | gap and polar group which become a water vapor transmission path more efficiently.

  Further, according to claim 3, when the binding energy of the P2p peak measured by XPS of the protective layer is in the range of 132 eV to 135 eV, it is possible to suppress the expansion of voids serving as a water vapor transmission path, As a result, water vapor barrier properties excellent in durability and durability can be imparted.

  According to claim 4, when the thickness of the protective layer is 3 nm to 10 nm, it is easy to control the uniform film thickness, and appropriate flexibility can be imparted. There is an effect of preventing the occurrence of cracks due to mechanical factors.

  Thus, according to the present invention, it is possible to provide a gas barrier laminate that can maintain a high barrier property against water vapor even in a high temperature and high humidity environment of 60 ° C. or higher.

It is sectional drawing which shows one Embodiment of the gas barrier laminated body of this invention.

  Hereinafter, a gas barrier laminate according to an embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the gas barrier laminate according to the present invention is characterized in that at least a barrier layer 2 and a protective layer 3 are sequentially laminated on a plastic film substrate 1. Moreover, the same structure can also be given to the front and back of the plastic film base material 1. FIG. FIG. 1 shows an example in which the anchor coat layer 4 is provided between the plastic film substrate 1 and the barrier layer 2 in order to obtain better adhesion, but there is no particular limitation.

  Examples of the plastic film substrate 1 used in the present invention include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate and copolymers thereof, and nylon. Examples thereof include polyamide resins such as −6, nylon-66 and nylon-12, and hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer.

  The plastic film substrate 1 (hereinafter simply referred to as a substrate) may be a stretched film or an unstretched film. A stretched film, particularly a biaxially stretched film is preferable because the processability (printing, laminating, etc.) of the resulting composite structure is excellent. The biaxially stretched film may be a biaxially stretched film produced by any one of a simultaneous biaxial stretching method, a sequential biaxial stretching method, and a tubular stretching method.

  The thickness of the substrate is not particularly limited, and a film obtained by laminating films having different properties in addition to a single film can be used. Considering the workability when forming the plasma pretreatment and the composite coating layer, a practical range of 3 to 200 μm is preferable, and a range of 6 to 100 μm is particularly preferable.

  By sequentially laminating a barrier layer 2 made of a reaction product of an aluminum alkoxide and a phosphorus compound and a protective layer 3 made of a reaction product of an isocyanate compound and a phosphorus compound on the base material, a high temperature of 60 ° C. or higher It was found that the barrier property against water vapor can be maintained even in a wet environment. Based on such investigation results, the present inventor made the gas barrier having high durability and excellent water vapor barrier properties by setting the protective layer 3 made of a reaction product of an isocyanate compound and a phosphorus compound to a desired composition ratio. A laminate can be produced. That is, the composition of the protective layer 3 made of these reaction products has an oxygen / phosphorus atomic ratio (O / P) calculated by X-ray photoelectron spectroscopy (XPS) in the range of 2.0 to 5.0. Therefore, the high barrier property against water vapor can be maintained by blocking voids and polar groups which are water vapor transmission paths of the barrier layer 2 made of a reaction product of the aluminum alkoxide and the phosphorus compound.

  Furthermore, when the binding energy of the P2p peak measured by XPS of the protective layer 3 is in the range of 132 eV to 135 eV, expansion of the voids in the barrier layer can be suppressed, and a highly durable protective film against water vapor barrier properties can be obtained. .

  The thickness of the protective layer 3 is preferably in the range of 3 nm to 10 nm, and it is possible to obtain a gas barrier property having uniform thickness and flexibility. If it is too thin, a uniform film cannot be formed, and it will be difficult to sufficiently function as a protective layer of the gas barrier material. On the other hand, if it is too thick, flexibility cannot be maintained due to residual stress, and cracks may occur due to external factors after film formation.

  The gas barrier laminate according to the embodiment may have a structure in which an anchor coat layer 4 is formed on the surface of a substrate 1 and the barrier layer 2 is provided on the anchor coat layer 4 as shown in FIG. The anchor coat layer 4 can be formed by applying an anchor coat agent to the surface of the substrate 1 and drying it. The anchor coat layer 4 has an effect of further improving the adhesion between the substrate 1 and the barrier layer 2.

  Anchor coating agents include, for example, solvent-soluble or water-soluble polyester resins, isocyanate resins, urethane resins, acrylic resins, urethane resins, vinyl alcohol resins, ethylene vinyl alcohol resins, vinyl modified resins, epoxy resins, oxazoline-containing resins, modified resins It is selected from styrene resin, modified silicone resin or alkyl titanate, and these can be used alone or in combination of two or more.

  The anchor coat layer 4 can be usually about 5 nm to 5 μm thick. The anchor coat layer 4 having such a thickness can be formed on the substrate surface with a uniform film thickness in which internal stress is suppressed. A more preferable thickness of the anchor coat layer 4 is 10 nm to 1 μm. In addition, in order to improve the applicability | paintability and adhesiveness of the anchor coat layer 4, you may give electric discharge processes, such as a corona process, to the base material 1 surface prior to an anchor coat.

  The chemical effect which provides a functional group to the base material 1 surface is acquired. Further, a physical effect of removing surface impurities and increasing the surface roughness can be obtained. As a result, the adhesion between the substrate 1 and the barrier layer 2 is further improved, and both have a structure with excellent adhesion even in a high-temperature and high-humidity test of 60 ° C. or higher.

  The protective layer 3 can be improved by adding a filler to improve barrier properties, wear properties, slip properties, and the like. Examples of the filler include silica sol, alumina sol, particulate inorganic filler, and layered inorganic filler. These can be used alone or in combination of two or more. The overcoat layer is preferably formed by adding a filler to the aforementioned resin and polymerizing or condensing it.

  When the barrier layer 2 is provided only on one side of the substrate 1, a layer containing a known additive such as an antistatic agent, an ultraviolet absorber, or a plasticizer may be provided on the other side.

  The gas barrier laminate according to the embodiment can be laminated with another film in consideration of suitability as a packaging material. As this film, for example, a polyester film such as polyethylene terephthalate, a fluorine-based resin film such as nylon, a polyvinyl fluoride film, or a polyvinyl fluoride can be used. Furthermore, resin films other than these can be laminated.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples.

<Example 1>
A PET film having a thickness of 100 μm was used as a base material, and a urethane resin was formed as an anchor coat layer with a thickness of 50 nm thereon by a gravure coating method. Next, a barrier layer made of a reaction product of an aluminum alkoxide and a phosphorus compound was applied onto the anchor coat layer by a gravure coating method and dried to form a thickness of 300 nm. Next, the protective layer which consists of a reaction product of an isocyanate compound and a phosphorus compound was apply | coated on the barrier layer by the gravure coating method, it was made to dry and was formed in thickness of 5 nm, and the gas barrier laminated body was produced.

  The obtained gas barrier laminate had an O / P ratio of 2.5 and a P2p peak binding energy of 132.2 eV. In addition, the measuring apparatus used for X-ray photoelectron spectroscopy (XPS) is an X-ray photoelectron spectroscopy analyzer (XPS: JEOL Ltd., JPS-90MXV). As the X-ray source, non-monochromated MgKα (1253.6 eV) was used, and measurement was performed with an X-ray output of 100 W (10 kV-10 mA). Relative sensitivity factors of 2.28 for O1s and 1.29 for P2p were used for quantitative analysis to determine the O / P ratio, respectively.

<Example 2>
Except that the mixing ratio of the isocyanate compound and the phosphorus compound was changed so that the O / P ratio was 3.2 and the binding energy of the P2p peak was 132.8 eV, and the drying conditions of the barrier layer and the protective layer were adjusted. In the same manner as in No. 1, a gas barrier laminate was produced.

<Example 3>
Except for changing the blending ratio of the isocyanate compound and the phosphorus compound and adjusting the drying conditions of the barrier layer and the protective layer so that the O / P ratio is 3.8 and the binding energy of the P2p peak is 133.3 eV. In the same manner as in No. 1, a gas barrier laminate was produced.

<Example 4>
Except that the mixing ratio of the isocyanate compound and the phosphorus compound was changed so that the O / P ratio was 4.2 and the binding energy of the P2p peak was 133.9 eV, and the drying conditions of the barrier layer and the protective layer were adjusted. In the same manner as in No. 1, a gas barrier laminate was produced.

<Example 5>
Except that the mixing ratio of the isocyanate compound and the phosphorus compound was changed so that the O / P ratio was 4.8 and the binding energy of the P2p peak was 134.5 eV, and the drying conditions of the barrier layer and the protective layer were adjusted. In the same manner as in No. 1, a gas barrier laminate was produced.

<Comparative Example 1>
Except that the mixing ratio of the isocyanate compound and the phosphorus compound was changed so that the O / P ratio was 1.6 and the binding energy of the P2p peak was 131.8 eV, and the drying conditions of the barrier layer and the protective layer were adjusted. In the same manner as in No. 1, a gas barrier laminate was produced.

<Comparative example 2>
Except that the mixing ratio of the isocyanate compound and the phosphorus compound was changed so that the O / P ratio was 5.5 and the binding energy of the P2p peak was 135.5 eV, and the drying conditions of the barrier layer and the protective layer were adjusted. In the same manner as in No. 1, a gas barrier laminate was produced.

<Comparative Example 3>
Except that the mixing ratio of the isocyanate compound and the phosphorus compound was changed so that the O / P ratio was 6.2 and the binding energy of the P2p peak was 136.1 eV, and the drying conditions of the barrier layer and the protective layer were adjusted. In the same manner as in No. 1, a gas barrier laminate was produced.

<Evaluation>
About the gas barrier laminated body obtained in Examples 1-5 and Comparative Examples 1-3, water vapor permeability (WVTR) was measured and water vapor barrier property was evaluated. The apparatus was a DELTAPERM manufactured by Technolox, and the measurement conditions were 60 ° C. and 90%.
As an evaluation standard, less than 50 mg / m ² · day was accepted (◯), and 50 mg / m ² · day or more was rejected (x).
Table 1 shows the evaluation results.

<Comparison result>
As apparent from Table 1, the gas barrier laminates of Examples 1 to 5 in which the O / P of the production reaction part barrier layer was adjusted to 2.0 to 5.0 and the binding energy of the P2p peak was adjusted to 132 to 135 eV were water vapor. The transmittance (WVTR) was less than 50 mg / m ² · day and passed.
On the other hand, Comparative Examples 1 to 3, in which the O / P of the product reactant barrier layer is 2.0 to 5 and the binding energy of the P2p peak is out of the range of 132 to 135 eV, the water vapor permeability is 50 mg / m ² · day or more. It was rejected.
As described above, when the protective layer for the product of the isocyanate compound and the phosphorus compound falls within the specified range, a gas barrier laminate exhibiting excellent high barrier property against water vapor can be provided even in a high temperature and high humidity environment.

  The present invention can provide a gas barrier laminate used as a gas barrier film for food packaging materials, medical and pharmaceutical packaging materials, and electronic media.

DESCRIPTION OF SYMBOLS 1 ... Plastic film base material 2 ... Barrier layer 3 ... Protective layer 4 ... Anchor coat layer

Claims (4)

A gas barrier laminate in which at least a barrier layer and a protective layer are sequentially laminated on a plastic film substrate,
The barrier layer comprises a reaction product of aluminum alkoxide and a phosphorus compound,
The said protective layer consists of a reaction product of an isocyanate compound and a phosphorus compound, The gas barrier laminated body characterized by the above-mentioned.   The composition of the protective layer is such that the atomic ratio (O / P) of oxygen and phosphorus calculated by X-ray photoelectron spectroscopy (XPS) is in the range of 2.0 to 5.0. A gas barrier laminate as described in 1.   The gas barrier laminate according to claim 1 or 2, wherein the P2p peak binding energy measured by XPS of the protective layer is in the range of 132 eV to 135 eV.   The gas barrier laminate according to any one of claims 1 to 3, wherein the protective layer has a thickness of 3 nm to 10 nm.

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