JP2892695B2 - Transparent high barrier plastic film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 【Technical field】

INDUSTRIAL APPLICABILITY The present invention is a transparent high-performance resin having excellent transparency, gas barrier properties, retort sterilization resistance, etc., and capable of stably obtaining useful properties as a packaging material or a gas barrier material in the fields of food and drink, clothing, electronic materials, and the like. Related to barrier plastic films.

[Prior art]

Conventionally, silicon oxide is vapor-deposited on a film surface for the purpose of improving the gas barrier property of a plastic film, as shown in JP-B-53-12953. Further, the silicon oxide vapor-deposited plastic film obtained in the semi-continuous winding vapor deposition by the same method has a moisture permeability:
A value of 3.0 g / m ² · 24 Hrs. Or less and an oxygen permeability: 2.0 cc / m ² · 24 Hrs. Or less are obtained, and are known to be practically effective. However moisture permeability:. 1.0g / m ² · 24Hrs less, oxygen permeability:. 0.5cc / m ² · 24Hrs the following values are obtained silicon oxide deposited plastic film At a production on an industrial scale, stable Manufacturing of the product was difficult. The reason is that a mixture of Si: SiO ₂ = 1: 1 (molar ratio) is used as the evaporation material, and a film of SiO _x is formed in the vapor deposition process. On the other hand, if SiO is used as the evaporating substance, a product having generally satisfactory performance can be obtained, but the production cost is high and there is a problem in practical use. In addition, in the case of a silicon oxide vapor-deposited plastic film alone, a very small amount, due to defects such as minute pinholes and minute cracks present in the silicon oxide vapor-deposited film, for example, moisture permeability: 2.3 g / m ² ., oxygen permeability: 1.8cc / m ² · 24Hrs.
It is common to indicate values such as. Attempts have also been made to increase the thickness of the silicon oxide vapor-deposited film in order to obtain an excellent transparent film having a small water vapor transmission rate and oxygen permeability. Defects such as minute cracks are not improved, and only the coloring of the obtained film becomes darker, which causes another problem that transparency is deteriorated.

[Object of the invention]

The present invention relates to a transparent high-barrier plastic film comprising a silicon oxide vapor-deposited plastic film provided with a silicon oxide vapor-deposited film directly or through an undercoat layer on one side of the plastic film. Excellent transparency, gas barrier property, retort sterilization resistance, etc.
An object of the present invention is to provide a transparent high-barrier plastic film capable of stably obtaining useful performance as a packaging material or a gas barrier material in the fields of food and drink, pharmaceuticals, electronic materials, and the like.

Configuration of the Invention

According to the present invention, two silicon oxide-deposited plastic films provided with a silicon oxide-deposited film are bonded to one side of the plastic film directly or via an undercoat layer such that the silicon oxide-deposited film side is on the inside. It is a transparent high barrier plastic film characterized by the above. That is, according to the present invention, two silicon oxide-deposited plastic films provided with a silicon oxide-deposited film are bonded to one side of the plastic film directly or via an undercoat layer such that the silicon oxide-deposited film side is on the inside. As a result, a transparent high-barrier plastic film having excellent transparency, gas barrier properties, and retort sterilization resistance, and capable of stably obtaining a film useful as a packaging material or a gas barrier material in the fields of foods and beverages, pharmaceuticals, electronic materials, and the like. Is made possible. As the plastic film in the method for producing a transparent high-barrier plastic film of the present invention, any plastic film having sufficient self-holding properties can be used.For example, polyethylene terephthalate, polyamide,
Film-like or sheet-like materials such as polyamideimide, polyethylene, polypropylene, cellulose acetate, polycarbonate, polyvinyl chloride, and fluororesin are used as appropriate. In particular, it is preferable to use a plastic film having a thickness of about 3 to 100 μm as the plastic film, since a transparent high barrier plastic film free of wrinkles and cracks can be continuously mass-produced. The plastic film may be uniaxially stretched or biaxially stretched, and biaxially stretched one is preferably used from the viewpoint of gloss and strength. Further, the plastic film may be one whose surface has been subjected to a surface treatment such as a corona discharge treatment or a low-temperature plasma treatment, and is generally preferable because the adhesion between the film and the deposited silicon oxide can be improved. Furthermore, the plastic film may have an undercoat layer provided on its surface, and as a resin for forming the undercoat layer, for example, a thermoplastic resin, a thermosetting resin,
Both electron beam curable resin and ultraviolet elevated resin are used, for example, acrylic resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polycarbonate,
Nitrocellulose, cellulose acetate, urethane-based resin, urea-based resin, melamine-based resin, urea-melamine-based resin, epoxy-based resin, alkyd-based resin, aminoalkyd-based resin, rosin-modified maleic resin, or a mixture thereof, or silane Coupling agents are preferably used. For the formation of the undercoat layer, an ordinary organic coating such as a roll coating method, a gravure coating method, a reverse coating method, a spray coating method, and the like, an organic solvent solution of the resin for forming the undercoat layer, an aqueous solution or a coupling agent. It is performed by applying by a method and drying (curing in the case of a thermosetting resin, an electron beam curable resin, an ultraviolet curable resin, or the like). The undercoat layer may be colored with a coloring material such as a general-purpose dye or pigment. A coloring material such as a dye or a pigment is appropriately selected from a range of about 3 to 30% with respect to a resin for forming the undercoat layer. In the transparent high barrier plastic film of the present invention, silicon monoxide alone, approximately equimolar%
Of silicon and silicon dioxide, and a mixture of substantially equimolar silicon and silicon dioxide and 1 mol% or more and less than 30 mol% of silicon monoxide, and formed by a known vacuum evaporation method. Is done. When silicon monoxide is added in an amount of 1 to 30 mol% to the conventional evaporation material of silicon and silicon dioxide in an equimolar amount, in a reaction system of Si + SiO ₂ → 2SiO _x (1), silicon monoxide is an initiator for accelerating the reaction. And plays the role of smoothly performing the reaction of the above (1). It is therefore a preferred evaporative raw material in view of economy and product quality obtained. In the present invention, the thickness of the silicon oxide vapor deposition film is not particularly limited, but is appropriately selected and determined depending on the use of the product and the desired performance, etc., in consideration of gas barrier properties and bending resistance. Usually, it is selected from the range of about 10 to 1000 nm, preferably about 50 to 200 nm. The adhesive and the bonding method in the transparent high barrier plastic film of the present invention are not particularly limited, and ordinary laminating methods and adhesives are used. As an adhesion method, for example, an extrusion lamination method, a dry lamination method, a solventless lamination method, or the like is appropriately used. Examples of the adhesive include acryl-vinyl chloride-vinyl acetate, acrylic, ethylene-vinyl acetate, epoxy, styrene-butadiene, polyester-isocyanate, polyethylene, vinyl chloride-vinyl acetate, and vinyl chloride. , Vinyl acetate, chlorinated polypropylene, and urethane adhesives are used alone or in appropriate blends. The thickness of the adhesive layer is usually selected from the range of 2 to 100 μm, preferably 3 to 10 μm. If the thickness of the adhesive layer is less than 2 μm, sufficient adhesive strength cannot be obtained, which is not preferable. On the other hand, even if it exceeds 100 μm, no change is recognized to the extent that it contributes to the adhesive strength. The plastic film surface may be provided with a protective layer, a protective film, a heat-sealing layer, and a printing layer such as a character pattern by a conventional method, so that the use thereof can be expanded. Next, the present invention will be described with reference to examples.

[Examples and Comparative Examples]

Comparative Example 1 Silicon monoxide was vacuum-deposited on a 12 μm-thick polyethylene terephthalate film surface under a vacuum of 5 × 10 ⁻⁵ Torr to a thickness of 100 nm to obtain a silicon oxide-deposited plastic film. Example 1 Two pieces of silicon oxide vapor-deposited plastic films obtained in Comparative Example 1 were bonded together using a polyurethane resin-polyisocyanate resin-based dry laminating adhesive so that the silicon oxide vapor-deposited film side was on the inside, and A transparent high barrier plastic film was obtained. Example 2 Linear high-density polyethylene was adhered to one surface of the transparent high-barrier plastic film of the present invention obtained in Example 1 using a polyurethane resin-polyisocyanate resin-based dry laminating adhesive. An application film of the film was obtained. With this film, heat sealing can be used for packaging electronic parts, the packaging work is easy and the contents can be checked without opening,
Moreover, it had a performance capable of maintaining sufficient quality.

【The invention's effect】

Using the silicon oxide vapor-deposited plastic film obtained in Comparative Example 1 and the transparent high barrier plastic films obtained in Examples 1 and 2, the moisture permeability and oxygen permeability of each of the five samples were measured. The moisture permeability and oxygen permeability of the transparent high barrier plastic films of Examples 1 and 2 were extremely stable.
It exhibited high performance not seen in the conventional silicon oxide-deposited plastic film (Comparative Example 1) (see Table 1).

Claims (1)

(57) [Claims] 1. Silicon monoxide alone, approximately equimolar% on one side of a plastic film directly or via an undercoat layer
A mixture of silicon and silicon dioxide, approximately equimolar to 1 mol% or more and 30 mol% of silicon and silicon dioxide
Two silicon oxide-deposited plastic films provided with a silicon oxide-deposited film formed of an evaporation material that is a kind of a mixture of are adhered together via an adhesive layer of 2 to 10 [mu] m, moisture permeability:. 1g / m ² · 24Hrs less, oxygen permeability:. 0.5cc / m ² · 24Hrs transparent high barrier, characterized in that less is Film.