JP4435397B2 - Transparent barrier film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is excellent in transparency and barrier properties such as oxygen and water vapor, and is also a packaging material or image for articles that require air resistance, moisture resistance, etc. such as foods, pharmaceuticals, seasonings, spices, fragrances, detergents, etc. The present invention relates to a transparent barrier film suitable for use as a moisture-proof material such as a display material, and more particularly suitable for packaging wet products.
[0002]
[Prior art]
Conventional barrier films (barrier laminates) include: (1) a physical vapor deposition method (PVD method) or a chemical vapor deposition method (CVD method) on at least one surface of a polymer film; And (2) those formed by vapor deposition of a metal such as aluminum, and (3) those coated with a polymer that is relatively excellent in air resistance, moisture resistance, and the like.
[0003]
Such conventional barrier laminates have the following problems.
(1) Transparent barrier laminates deposited with silicon oxide or aluminum oxide have been widely used in recent years for their excellent transparency, air resistance, and moisture resistance, but they have poor durability against repeated bending. There were problems, such as the point that property falls.
Among polymer films, polyester films are frequently used but have the above-mentioned problems. A relatively flexible and durable polyamide film is also used as the base film for transparent barrier laminates deposited with silicon oxide and aluminum oxide. Transparent inorganic oxide thin films such as silicon oxide and aluminum oxide and polyamide In the interfacial adhesiveness with the film, the adhesion strength is remarkably smaller than that of the polyester film, and the adhesion strength in the presence of moisture is particularly low.
[0004]
[Problems to be solved by the invention]
The present invention solves the problems of conventional transparent barrier laminates, and provides a transparent barrier film that is transparent, excellent in barrier properties, and particularly improved in “interfacial moisture strength”.
[0005]
[Means for Solving the Problems]
That is, the present invention is a transparent barrier film in which an oxide thin film (B) composed of at least Si, Mg, and Zr is provided on at least one surface of the film (A), and the oxide thin film (B) is configured. The metal weight ratio of Si, Mg and Zr is 80: 5 to 50:15 to 30, and the “interfacial moisture strength” between the film (A) and the oxide thin film (B) is 0.35 (N / Cm) or more, and is a transparent barrier film characterized by being on the surface of the film (A) and / or the oxide thin film (B) or the film (A) and the oxide thin film. It is a transparent barrier film characterized in that another resin layer is provided between (B).
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the transparent barrier film of the present invention, the film (A) is not particularly limited as long as it is transparent and can withstand vapor deposition, sputtering, and the like. For example, homopolymers such as nylon 6 and nylon 66, or these Polyamide film, polyethylene terephthalate, polyethylene naphthalate comprising a mixture of the above, a copolymer obtained by adding a copolycondensation component to the homopolymer in such a range that the basic performance is not significantly changed, and the like. Polyester film such as copolyester, Polyolefin film such as polypropylene and polyethylene, Cellulose triacetate film, Cellophane, Polycarbonate film, Polyether sulfone film, Acrylic film, Aliphatic polymer Biodegradable film such as ether or polylactic acid and chitosan. As long as the object of the present invention is not impaired, the film may contain a colorant, an ultraviolet absorber, a lubricant, an antioxidant and the like. The thickness of these films is not particularly limited, but is preferably about 4 μm to 200 μm, more preferably 12 μm to 40 μm.
[0007]
As the film (A) in the present invention, an oxide comprising at least one metal selected from at least Si, Mg and Zr, Sn, Ti on at least one surface of the film (A), which is the gist of the present invention. As long as it is a transparent barrier film provided with a thin film (B) consisting of the above, and it can be achieved that the “interface moisture strength” is 0.35 (N / cm) or more, it is not particularly limited, At least one of the longitudinal and transverse directions has a draw ratio of 3 times or more, and the elongation (in either the longitudinal direction or the transverse direction) is 110% or less. Also in the direction of 0.5% or less. When the boiling water shrinkage rate exceeds 0.5%, it becomes difficult to achieve “interfacial moisture strength” of 0.35 (N / cm) or more. Furthermore, when at least one of the longitudinal and transverse directions is less than 3 times the draw ratio, and the elongation exceeds 110% in both directions, the oxygen permeability and the water vapor permeability often cannot be improved. ”Is difficult to achieve 0.35 (N / cm) or more.
[0008]
The film (A) thin film (B) formation surface is subjected to pretreatment such as plasma treatment, corona treatment, ion bombardment treatment, etc., and the film (A) thin film formation surface is inlined and / or offline. In order to improve the “wet strength”, a so-called undercoat may be applied by coating a chemical or a resin, or other metal or metal compound may be applied to the thin film forming surface of the film (A) before forming the thin film (B). It is preferable to perform a treatment such as forming an extremely thin film of about 0.01 to 5 nm in advance, and the “interface moisture strength” of the present invention is 0.35 (N / cm) or more by performing such a treatment. Is often achieved.
The transparent barrier film having an “interfacial moisture strength” of 0.35 (N / cm) or more in the present invention is more preferably an “interfacial moisture strength” of 0.50 (N / cm) or more, more preferably an “interface” The “wet strength” is 0.65 (N / cm) or more.
[0009]
In the present invention, the thin film (B) made of at least one metal selected from Si, Mg and Zr, Sn, Ti formed on at least one side of the film (A) has a thickness of 10 to 300 nm. It suppresses the permeability of oxygen and water vapor (moisture) and forms a transparent film, and in particular, the metal weight of Si: Mg: (one or more metals selected from Zr, Sn, Ti) The ratio is preferably 80: 5 to 50: 0.1 to 30, for example, an oxide and Zr having a metal weight ratio of Si: Mg of 80: 5 to 50 using Si, SiO ₂ and MgO. In the thin film (B), the Zr content is 80: 5 to 50: 0.1 to 30 in terms of Si: Mg: Zr (metal weight ratio), and the metal weight ratio is Si: Mg. Sn: Sn oxide with oxide of 80: 5-50 The content of Si: Mg: Sn in the thin film (B) is 80: 5 to 50: 1 to 30, the metal weight ratio of Si: Mg is 80: 5 to 50 and the oxide of Ti An oxide having a Ti content of 80: 5 to 50: 0.1 to 30 in Si: Mg: Zr and a metal weight ratio of 80: 5 to 50 in Si: Mg in the thin film (B) And the total content of Zr and Sn consisting of an oxide of Zr and Sn is 80: 5 to 50: 0.1 to 30 in Si: Mg: (Zr + Sn) in the thin film (B). it can.
[0010]
An oxide thin film (B) made of one or more metals selected from Si, Mg and Zr, Sn, and Ti, and Si: Mg: (one or more metals selected from Zr, Sn, and Ti) A more preferable range of the metal weight ratio of one or more metals selected from Zr, Sn, and Ti in the thin film (B) of which the metal weight ratio is 80: 5 to 50: 0.1 to 30 is The metal weight ratio of Si: Mg: (one or more metals selected from Zr, Sn, Ti) is 80:10 to 30: 0.5 to 20, more preferably 80:10 to 30: 1 to 15. It is. One or more metal oxides selected from Zr, Sn, and Ti are preferably ZrO ₂ , SnO ₂ , and TiO ₂ , and those having an oxygen ratio of 2 or less and 1.5 or more for each metal are also preferable.
The thin film (B) having a metal weight ratio of 80: 5 to 50: 0.1 to 30 of Si: Mg: (one or more metals selected from Zr, Sn, Ti) in the thin film (B). When the metal weight ratio of one or more metals selected from Zr, Sn, and Ti is less than 1, the effect of “interfacial wet strength” containing the oxide is extremely small. Deterioration of the barrier performance is observed, and the yellow color of the thin film is excessively increased, which is not preferable as a transparent barrier film.
In addition, Si: Mg: (one or more metals selected from Zr, Sn, Ti) having a metal weight ratio of 80: 5 to 50: 0.1 to 30 in the thin film (B) : Mg ratio of 80: 5 to 50 is preferable. When the Mg ratio is less than 5, the effect of improving barrier properties and transparency is small, and when it exceeds 50, the water resistance of the thin film (B) is deteriorated. As described above, the thickness of the thin film (B) is preferably 10 to 300 nm. When the thickness of the thin film (B) is less than 10 nm, it is not preferable because the barrier property is insufficient. In this case, it is not preferable because cracks are easily generated, and it is not preferable in terms of economic efficiency.
[0011]
The formation of the thin film (B) in the present invention is for obtaining oxygen permeation resistance (suppressing oxygen permeability) and water vapor permeation resistance (reducing moisture permeability), and further improving the barrier property, and transparency. And a barrier film having an “interfacial moisture strength” of 0.35 (N / cm) or more, and the oxygen permeability of the transparent barrier film of the present invention. Is 50 ml / (m ² · d · MPa) or less, preferably 30 ml / (m ² · d · MPa) or less, and the moisture permeability is 5 g / (m ² · d) or less, preferably 3 g / (m ² · m · d) The following.
These thin films (B) can be formed on the film (A) by a conventionally known physical vapor deposition method (PVD method) such as a vacuum vapor deposition method, a sputtering method, an ion plating method, a plasma vapor deposition method, or a silicon compound. Reactive vacuum deposition, reactive sputtering in a mixture of one or more compounds of metals such as oxygen in an atmosphere of oxygen gas or a mixed atmosphere of these gases and an inert gas such as argon or nitrogen A conventionally known chemical vapor deposition method (CVD method) such as a method, a reactive ion plating method, or a reactive plasma vapor deposition method can be employed.
These forming methods include forming directly on one side of the film (A), or forming it through an undercoat layer, or forming the film after plasma treatment, or first adding a metal such as chromium to the film. It is also applicable to form a nucleation layer with a thickness of about nm and then form a thin film (B).
[0012]
In the present invention, after forming the thin film (B) on the film (A), by providing another film or resin on the thin film (B) and / or the film (A), it is more practical as a packaging material. Can be. These films and resins are not particularly limited and are appropriately selected and used depending on the purpose.
For example, it is used for the purpose of protecting the thin film (B), providing further gas barrier properties, a sealing material, a printed layer, and the like. For example, an ethylene-vinyl alcohol copolymer (EVOH) resin layer or the like is laminated on the thin film (B) in order to protect the thin film (B) and impart gas barrier properties.
[0013]
The ethylene - thickness of vinyl alcohol copolymer (EVOH) resin layer is preferably 0.1-5 g / m ^2, and more preferred are 0.2~1.5g / m ^2, 0.1g / m When less than ² , the effect of laminating the resin with the thin film (B) is not obtained. Conversely, when it exceeds 5 g / m ² , not only the economy but also the adhesiveness with the thin film (B) decreases. However, problems such as peeling off from the thin film (B) at the time of practical use as a packaging material, for example, lamination with a seal layer or the like and sealing.
As a preferable form in the present invention, a form in which an electrostatic induction preventing agent is added and contained in the ethylene-vinyl alcohol copolymer (EVOH) resin layer can be mentioned. The antistatic induction agent in the present invention is an antistatic induction agent such as acrylic resin (eg, Konishi; Bondip PA100), and a transparent high barrier polyamide film is often laminated with a seal layer or other layers. Even in that case, the addition of the antistatic agent to the resin layer can maintain sufficient antistatic properties in the outermost layer of the transparent high barrier polyamide film laminate, and the resin layer (C) A suitable additive content of the antistatic induction agent is 5 to 50% by weight.
[0014]
【Example】
The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.
In addition, the measurement of ** "interfacial moisture strength" in the present invention is that the thin film (B) is provided on the obtained film (A) but the thin film (B) is not provided on the thin film (B). 40 μm-thick LLDPE film using an adhesive whose “interfacial wet strength” is at least 1.30 (N / cm) or more when dry-laminating a 40 μm-thick LLDPE film directly on the film (A) This was cut into a square of 100 mm × 100 mm, immersed in pure water at atmospheric pressure for 0.5 hour, taken out from the pure water, and surface water was removed with a filter paper, followed by 20 ° C., 65% After leaving to stand for 3 hours in RH, chopped to 15 mm width and 100 mm length, and containing pure water at the interface between the film (A) and the thin film (B) (regardless of the presence or absence of an undercoat layer, etc.) T-type peeling and “interfacial moisture strength” It is a method of measurement.
[0015]
* Example 1
An oxide thin film in which a polyethylene terephthalate film having a thickness of 12 μm is used as the film (A), and the metal weight ratio of Si: Mg: Zr is 80: 19: 4 as a thin film (B) directly by vapor deposition on the film surface. Was formed with a thickness of 50 nm to obtain a transparent barrier film.
The obtained transparent barrier film had an oxygen permeability of 4 ml / (m ² · d · MPa) and a moisture permeability of 0.5 g / (m ² · d).
Furthermore, the “interfacial moisture strength” was 1.30 (N / cm) or more.
[0016]
* Example 2
An oxide thin film in which a polyethylene terephthalate film having a thickness of 12 μm is used as the film (A), and the metal weight ratio of Si: Mg: Zr is 80: 45: 5 as a thin film (B) directly by vapor deposition on the film surface. Was formed with a thickness of 50 nm to obtain a transparent barrier film.
The obtained transparent barrier film had an oxygen permeability of 3 ml / (m ² · d · MPa) and a moisture permeability of 0.3 g / (m ² · d).
Furthermore, the “interfacial moisture strength” was 1.30 (N / cm) or more.
[0017]
* Example 3
An oxide thin film in which a polyethylene terephthalate film having a thickness of 12 μm is used as the film (A), and the metal weight ratio of Si: Mg: Zr is 80: 8: 4 as a thin film (B) directly by vapor deposition on the film surface. Was formed with a thickness of 50 nm to obtain a transparent barrier film.
The obtained transparent barrier film had an oxygen permeability of 7 ml / (m ² · d · MPa) and a moisture permeability of 0.7 g / (m ² · d).
Furthermore, the “interfacial moisture strength” was 1.30 (N / cm) or more.
[0018]
* Example 4
A polyethylene terephthalate film having a thickness of 12 μm is used as the film (A), and a polyester resin layer (from a polyester compound and a polyisocyanate compound) is applied to the film surface as an undercoat layer. Then, an oxide thin film having a Si: Mg: Zr metal weight ratio of 80:19:15 as a thin film (B) is formed on the undercoat layer on the undercoat layer by vapor deposition to a thickness of 50 nm. A transparent barrier film was obtained.
The obtained transparent barrier film had an oxygen permeability of 3 ml / (m ² · d · MPa) and a moisture permeability of 0.3 g / (m ² · d).
Furthermore, the “interfacial moisture strength” was 2.0 (N / cm) or more.
[0019]
* Comparative Example 1
A polyethylene terephthalate film having a thickness of 12 μm is used as the film (A), and an oxide thin film having a Si: Mg metal weight ratio of 80:19 is formed on the film surface as a thin film (B) by vapor deposition directly to a thickness of 50 nm. A transparent barrier film was obtained.
The obtained transparent barrier film had an oxygen permeability of 9 ml / (m ² · d · MPa) and a moisture permeability of 0.9 g / (m ² · d).
Furthermore, the “interfacial moisture strength” was 0.3 (N / cm) or less.
[0020]
【The invention's effect】
The transparent barrier film of the present invention is excellent in oxygen permeability and moisture permeability, excellent in “interfacial moisture strength”, excellent in bending resistance, and also suitable for microwave ovens, particularly a wet food. It is extremely useful as a packaging material.

Claims (2)

On at least one side of the film (A),
A transparent barrier film provided with an oxide thin film (B) comprising at least Si, Mg, and Zr,
The metal weight ratio of Si, Mg and Zr constituting the oxide thin film (B) is 80: 5 to 50:15 to 30,
“Interfacial wet strength” between the film (A) and the oxide thin film (B) is 0.35 (N / cm) or more,
A transparent barrier film characterized by The transparent barrier film according to claim 1,
Providing another resin layer on the surface of the film (A) and / or the oxide thin film (B) or between the film (A) and the oxide thin film (B);
A transparent barrier film characterized by