JPH08156183A - Barrier laminate - Google Patents

Abstract

PURPOSE: To obtain a barrier laminate prevented from the generation of wrinkles and not deteriorated in gas barrier properties at the time of processing by laminating a vapor deposition membrane layer composed of metal or a metal compd. on a polyester film of which the surface roughness is within the range between two specific formulae. CONSTITUTION: A barrier laminate 4 is obtained by laminating a vapor deposition membrane layer composed of metal or a metal compd. on a polyester film of which the surface roughness is within the range between formula Y=165.49×X<-1.288> [wherein Y is center line average roughness (SRa) and X is the number of ridges (SPc) with SRa or more present per 1mm<2> ) and formula Y=10.80×X<-1.153> . The barrier laminate 4 consists of the polyester film barrier material 1 and the vapor deposition membrane layer 2 and the interface thereof is the surface 3 of the polyester film base material. As the polyester film base material 1, a polyester film of polyethylene terephthalate (PET) or polyethylene 2,4-naphthalate (PEN) can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier laminate which can be effectively blocked from permeation of gases such as oxygen and water vapor, which is used in the field of packaging foods, pharmaceuticals and the like.

[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 the case of pharmaceuticals that require aseptic handling, the effects of oxygen, water vapor and other gases that permeate the packaging material are prevented in order to prevent deterioration of the active ingredient and maintain efficacy. Therefore, it is required to have a gas barrier property of blocking these gases.

For this reason, a polyvinyl alcohol film (P
VA), ethylene vinyl alcohol copolymer film (EVOH), polyacrylonitrile film (PAN), etc., and polypropylene films, polyethylene films, etc. as barrier films that block water vapor are used as packaging materials as gas barrier laminates. However, a packaging film made of this packaging material has been generally used. However, these films alone do not have gas barrier properties against both oxygen and water vapor, and are generally laminated or coated by laminating other types of polymer resin compositions having different properties which are said to have relatively high gas barrier properties. Although it has been used as a film as a packaging material, it may not be able to exhibit a sufficient gas barrier property under the influence of temperature and humidity in the storage and use environments.

Further, there is a resin film having a gas barrier property against both oxygen and water vapor, and a polyvinylidene chloride film (PVDC), a polyester film, a polypropylene film, and a coated film obtained by coating polyvinylidene chloride on a nylon film are available. is there. When such a resin film is discarded after use and incinerated, a toxic gas is generated, which may cause an environmental problem.

On the other hand, as a packaging material which requires a high gas barrier property, a conventional resin film (even a resin which does not have a high gas barrier property by itself with a suitable polymer resin composition) is used as a packaging material. Metal foils made of metal have been used. Such a metal foil has excellent barrier properties against gases such as oxygen and water vapor, but when it is incinerated as waste after use, metal remains as a residue and is difficult to reuse. Environmental impact is unavoidable.

In order to solve the above problems, recently, silicon oxide (SiOx) such as silicon monoxide (SiO), metal such as aluminum oxide (AlxOy) and aluminum (Al), and metal oxide are used. Vapor-deposited films formed by forming means such as vapor-deposition on resin films have been developed, and these have gas barrier properties superior to those of gas-barrier materials composed of a polymer resin composition, and have little deterioration under high humidity, It is beginning to be used for packaging materials.

The packaging material made of these vapor-deposited films is rarely used as a vapor-deposited film alone, and is processed into a packaging container, a packaging bag or the like as post-processing after vapor deposition. For example, a packaging bag is processed into a bag shape by a bag-making process by further adhering a vapor deposition film to another base material.

[0008]

However, the vapor-deposited film obtained by forming a thin film of the above metal or metal oxide on the resin film, when the vapor-deposited thin film is damaged such as cracks or pinholes, There is a problem that a high barrier property, which is originally possessed, cannot be obtained because a gas such as oxygen or water vapor permeates.

These cracks, pinholes, and other damages occur because mechanical stress and thermal stress are applied to the vapor-deposited thin film in post-processing such as printing and laminating, and the vapor-deposited thin film is distorted. There are various factors such as dust that is mixed on the surface of the resin film peeling off together with the deposited thin film.

However, the most dominant factor is the protrusions on the surface of the resin film, which are caused by the additives present in the resin film, especially the lubricant. In other words, the vapor-deposited thin film formed on the protrusions is most likely to come into contact with rolls in various processing steps, so damage is likely to occur, or stress due to mechanical stress or thermal stress is generated on the protrusions where the vapor-deposited thin film is formed. Since it is easy to concentrate on the ridges, minute cracks may occur at the hem of the protrusion, or cracks may start from the protrusion.

Therefore, a vapor deposition thin film formed on a resin film having a large number of protrusions or a large number of protrusions on a resin film is often damaged by pinholes, cracks and the like, and a gas such as oxygen and water vapor easily penetrates. I have a problem.

To solve such a problem, for example, there is a method of reducing the amount of lubricant added and reducing the number of protrusions on the surface of the resin film to reduce the number of damages to the vapor-deposited thin film. However, by reducing the number of protrusions on the surface of the resin film, slipperiness is deteriorated between the resin films or between rolls during processing, and winding wrinkles easily occur.

As another method, there is a method in which the particle size (size) of the lubricant is reduced and the projection size on the surface of the resin film is reduced to reduce the damage size generated in the vapor-deposited thin film. However, as in the above method, the slipperiness is poor, winding wrinkles are generated, or the lubricants are easily aggregated, and it is very difficult to control the projection size.

There are several other methods, but the problem with each method is that the protrusions on the surface of the resin film exhibit the slipperiness and the vapor-deposited thin film requires the barrier property. The smoothness means that projections on the surface of the resin film are required to contradict each other in order to obtain sufficient performance.

Therefore, the present invention does not hinder workability and productivity such as generation of wrinkles during processing such as vapor deposition, printing and laminating, and is a gas barrier against gases such as oxygen and water vapor originally possessed by the vapor deposited thin film. It is an object of the present invention to provide a barrier laminate having high practicality without deteriorating the properties.

[0016]

According to the invention described in claim 1, the surface roughness is Y = 165.49 × X ^−1.288 (however,
Y is the center line average roughness (hereinafter abbreviated as SRa), X is 1 mm
Number of mountains above SRa existing in ² (hereinafter abbreviated as SPc))
And Y = 10.80 x X ^-1.153 (where Y is SRa, X
The present invention provides a barrier laminate, comprising a vapor-deposited thin film layer of a metal or a metal compound laminated on a polyester film in the range between SPc).

The invention described in claim 2 is based on the invention described in claim 1, and is a barrier laminate obtained by further laminating an adhesive layer and a thermoadhesive resin layer on the vapor-deposited thin film layer in this order. is there.

[0018]

The barrier property of a vapor-deposited film obtained by laminating a vapor-deposited thin film layer comprising a metal or a metal compound relating to the present invention on a polyester film has a close correlation with damage such as pinholes and cracks in the vapor-deposited thin film. Is the basis.

As in the present invention, if the number of protrusions on the surface of the polyester film and the protrusion size are in an appropriate relationship, pinholes formed in the vapor-deposited thin film laminated on the polyester,
Damage such as cracks can be suppressed to a minimum level without impairing the high barrier property that the vapor-deposited thin film can originally hold. Furthermore, the slipperiness of the resin film and the vapor-deposited film can also suppress the occurrence of wrinkles that adversely affect productivity and workability. Thus, both advantages of the two seemingly contradictory properties can coexist.

[0020]

Embodiments will be described in detail based on embodiments of the present invention.

FIG. 1 is a sectional view for explaining the constitution of the barrier laminate of the present invention, and FIG. 2 is a sectional view for explaining another constitution of the barrier laminate of the present invention. The barrier laminate 4 is composed of a polyester film substrate 1 and a vapor-deposited thin film layer 2, and its interface is a polyester film substrate surface 3.

The polyester film substrate 1 is in the form of a sheet or a film, and a polyester film such as polyethylene terephthalate (PET) or polyethylene 2.4-naphthalate (PEN) can be used.
These polyester film base materials 2 are appropriately selected according to the application. If necessary, it can be used as a biaxially stretched resin film.

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

However, in the case of those known additives such as lubricants having a function of forming protrusions on the surface 3 of the polyester film base material, the surface roughness of the surface 3 of the polyester film base material is within a specific range. It is necessary to be. That is, the surface 3 of the polyester film substrate
Among several indexes of surface roughness of S, the center line average roughness (SRa) and the number of peaks (SRa) of 1 mm ² and above SRa (S
Pc), Y = 165.49 × X ^−1.288 (where Y: SRa, X: ^SPc ) (formula A) and Y = 10.8.
It is necessary that the surface roughness be such that it is sandwiched between 0 × X ^−1.153 (where Y: SRa, X: ^SPc ) (formula B).

Furthermore, the surface of the polyester film base material 1 on which the vapor-deposited thin film layer 2 is formed, that is, the surface 3 of the polyester film base material, is publicly known by corona discharge treatment, reverse sputtering treatment, plasma activation treatment, glow discharge treatment or the like. The surface activation treatment may be carried out as long as the surface roughness of the polyester film substrate 1 is within the range between (Formula A) and (Formula B). Further, a coating agent such as ethyleneimine-based, amine-based, epoxy-based, urethane-based, polyester-based coating agent is applied on the surface 3 of the polyester film base material offline or in-line, and the surface roughness of the applied layer is expressed by the formula (Formula A ) (Equation B) may be applied as long as it does not fall outside the range between the two.

The thickness of the polyester film substrate 1 is not particularly limited, but in consideration of the processability in the vapor deposition process, it is 2
The range of 400 μm is preferable.

The deposited thin film layer 2 includes Al, Si, Ti and Z.
Metals such as n, Zr, Mg, Sn, Cu and Fe and oxides, nitrides, sulfides and fluorides of these metals such as Al ₂ O ₃ , SiO, SiO ₂ , TiO ₂ and ZrO.
₂ , MgO, SnO ₂ , ZnS, and MgF ₂ are used. As a forming method, an evaporation method such as vacuum evaporation, ion plating, or sputtering can be used, but vacuum evaporation and ion plating are preferable from the viewpoint of production efficiency. Resistance heating, electron beam (EB) heating, high frequency induction heating, or the like is used as a heating method for the vapor deposition apparatus.

The inside of the vapor deposition apparatus is 2 × 10 ⁻⁶ to 8 × 10 ^−3.
After evacuation to Torr, preferably 8 × 10 ⁻⁶ to 8 × 10 ⁻⁵ , a vapor deposition process is performed. The vapor-deposited metal thin film has a barrier property against oxygen and water vapor, but the barrier property varies depending on the material and film thickness of the thin film. Particularly, aluminum, silicon oxide, aluminum oxide and the like have excellent barrier properties.

The thickness of the vapor deposited thin film layer 2 may be in the range of 5 to 500 nm, preferably 30 to 150 nm.
This is because when the film thickness is less than 5 nm, the vapor-deposited thin film is likely to come off and the barrier property is apt to vary.
When it exceeds m, the flexibility of the vapor-deposited thin film is impaired, cracks and pinholes are easily generated, and the barrier properties are deteriorated. The vapor-deposited thin film is not limited to a single layer of a single component, and may be a vapor-deposited thin film made of a mixture of the above vapor deposition materials, or may be a multilayer having two or more layers.

Further, the heat-adhesive resin layer 6 is laminated on the vapor-deposited thin film layer 2 of the barrier laminate 7 of the present invention shown in FIG. 2 with the adhesive layer 5 interposed therebetween. With this heat adhesive resin layer 6,
Processed into packaging containers such as bags and containers.

The heat-adhesive resin layer 8 is a resin layer which is easily heat-sealed by heating and pressing, and is made of, for example, polyolefin such as polyethylene, polypropylene and ethylene-propylene copolymer, polyester, polyamide, ionomer, ethylene-vinyl acetate copolymer. Examples thereof include acrylic resins such as acrylic acid esters and methacrylic acid esters, polyvinyl acetals, phenol resins, modified epoxy resins and copolymers and mixtures thereof, but are not limited to these as long as the above conditions are satisfied. Not a thing. In particular, polyolefin, polyester, polyamide, ethylene vinyl acetate copolymer and the like are preferable.

The layer thickness of the heat-adhesive resin layer 8 varies depending on the use, but is in the range of 1 to 200 μm, preferably 10
˜100 μm. As a forming method, a general processing method such as a dry laminating method, a solventless laminating method or an extrusion laminating method can be used.

[0033]

EXAMPLES Hereinafter, specific examples of the present invention will be described in detail.

<Example 1> Heat of fusion of crystal 9.7 cal / g
Polyethylene terephthalate was extruded from the die with an extruding device and electrostatically applied on a drum cooled to 40 ° C. to prepare an unstretched resin film having a thickness of 153 μm.
This film was stretched 3.65 times in the flow direction on a metal roll heated to 95 ° C., and then, through a preheating zone of 95 ° C., was stretched 3.85 times in the width direction at 102 ° C. Furthermore, 2
Heat treatment was performed at 00 to 230 ° C. for 4.0 seconds to prepare a 12 μm biaxially stretched polyethylene terephthalate film (PET).

The surface roughness of this PET film is SRa.
= 0.018 μm, SPc = 657.14 / mm ² .

This PET film was wound up and loaded into an EB heating vacuum vapor deposition apparatus, and the degree of vacuum was 1.5 × 10 ^-5 Torr.
After that, metal aluminum (purity 99.99%) was added to the PET film surface by EB-Power at 30 kV-
2A, winding speed 1.5m / sec, pressure 2 × 10 ^-4
The barrier laminate of Example 1 was produced by vapor-depositing with wbar to a film thickness of 100 nm to form an aluminum vapor-deposited layer.

<Example 2> 1 obtained by adjusting the particle size and addition amount of the lubricant in the polyethylene terephthalate raw material.
The surface roughness of a 2 μm biaxially stretched polyethylene terephthalate film (PET) is SRa = 0.007 μm, S
A barrier laminate was produced in the same manner as in Example 1 except that Pc was 1142.86 pieces / mm ² .

<Example 3> 1 obtained by adjusting the particle size and addition amount of the lubricant in the polyethylene terephthalate raw material.
The surface roughness of a 2 μm biaxially stretched polyethylene terephthalate film (PET) is SRa = 0.039 μm, S
A barrier laminate was prepared in the same manner as in Example 1 except that Pc was 271.43 pieces / mm ² .

Example 4 Silicon monoxide (purity: 99.99%) was used as the vapor deposition material, and EB-Power of the vapor deposition conditions was 30 k.
A barrier laminate was produced in the same manner as in Example 1 except that V-0.75A was used.

<Example 5> Silicon monoxide (purity: 99.99%) was used as the vapor deposition material, and EB-Power of the vapor deposition conditions was 30 k.
A barrier laminate was produced in the same manner as in Example 2 except that V-0.75A was used.

Example 6 Silicon monoxide (purity 99.99%) was used as the vapor deposition material, and EB-Power of the vapor deposition conditions was 30 k.
A barrier laminate was produced in the same manner as in Example 3 except that V-0.75A was used.

<Comparative Example 1> 1 obtained by adjusting the particle size and addition amount of the lubricant in the polyethylene terephthalate raw material.
The surface roughness of the biaxially stretched polyethylene terephthalate film of 2 μm is SRa = 0.206 μm, SPc = 10.
A barrier laminate was produced in the same manner as in Example 1 except that the number was 42.86 pieces / mm ² .

<Comparative Example 2> 1 obtained by adjusting the particle size and addition amount of the lubricant in the polyethylene terephthalate raw material.
The surface roughness of a 2 μm biaxially stretched polyethylene terephthalate film is SRa = 0.058 μm, SPc = 92.
A barrier laminate was produced in the same manner as in Example 1 except that the number was 8.57 pieces / mm ² .

<Comparative Example 3> 1 obtained by adjusting the particle size and the addition amount of the lubricant in the polyethylene terephthalate raw material.
The surface roughness of the 2 μm biaxially stretched polyethylene terephthalate film is SRa = 0.008 μm, SPc = 35.
A barrier laminate was produced in the same manner as in Example 1 except that the number was 0.37 / mm ² .

<Comparative Example 4> Silicon monoxide (purity: 99.99%) was used as the vapor deposition material, and EB-Power of the vapor deposition conditions was 30 k.
A barrier laminate was produced in the same manner as in Comparative Example 1 except that V-0.75A was used.

<Comparative Example 5> Silicon monoxide (purity: 99.99%) was used as the vapor deposition material, and EB-Power under the vapor deposition conditions was 30 k.
A barrier laminate was produced in the same manner as in Comparative Example 2 except that V-0.75A was used.

<Comparative Example 6> Silicon monoxide (purity: 99.99%) was used as the vapor deposition material, and EB-Power of the vapor deposition conditions was 30 k.
A barrier laminate was produced in the same manner as in Comparative Example 3 except that V-0.75A was used.

Examples 1 to 6 and Comparative Examples 1 to 6
The barrier laminates of were compared and evaluated as follows. Oxygen permeability showing the barrier property and moisture permeability are measured respectively,
Table 1 shows the results. In addition, the measurement condition is that the oxygen transmission rate is MOCON method (MOCON-OXTRAN-10 / 50).
In A), the setting is 25 ° C-100% RH. The moisture permeability is based on the Mocon method (MOCON-PERMATRAN-W6), and the setting is 40 ° C-90% RH.

[0049]

[Table 1]

From Table 1, good results were obtained in Examples 1 to 6, but Comparative Examples 1 to 6 were poor. Further, in Comparative Examples 3 and 6, winding wrinkles occurred during vapor deposition and laminating.

[0051]

As described above, according to the present invention, among the surface roughness parameters of the polyester film substrate, S
By setting Ra and SPc within specific ranges, damage such as pinholes and cracks that occur in the vapor-deposited thin film provided on the surface of the polyester film substrate can be minimized, and the original excellent oxygen and water vapor of the vapor-deposited thin film can be minimized. It is possible to maintain the barrier property against the gas.

[0052]

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyester film base material 2 Vapor-deposited thin film layer made of metal or metal compound 3 Surface of polyester film base material 4, 7 Barrier laminate 5 Adhesive layer 6 Thermal adhesive resin layer

Claims (2)

[Claims] 1. The surface roughness is Y = 165.49 × X ^−1.288.
(However, Y is the center line average roughness (hereinafter abbreviated as SRa), X
Is the number of peaks of SRa or more (hereinafter abbreviated as ^SPc ) existing in 1 mm ² and Y = 10.80 × X ^-1.153 (where Y is S
A barrier laminate comprising a polyester film having Ra and X in a range between SPc) and a vapor-deposited thin film layer made of a metal or a metal compound. 2. The barrier laminate according to claim 1, wherein an adhesive layer and a heat-adhesive resin layer are sequentially laminated on the vapor-deposited thin film layer.