JPH04128365A - Production of film for package - Google Patents

Abstract

PURPOSE:To obtain a film having excellent gas barrier property and high heat resistance, strength, and flexibility with good productivity by using an ion source to produce a SiOx beam and implanting this beam through a SiO2 film surface to form a SiOx film having a mixed state with the structure of a base material. CONSTITUTION:On at least one surface of a base material comprising a flexible plastic film, a SiOx layer (0<=x<2) having a mixed state with the structure of the base material and SiO2 film are successively formed. After forming the SiO2 film, an ion source is used to ionize SiOx (0<=x<2) to implant a SiOx beam on the SiO2 film surface by controlling the amt. of iron to be drawn and the acceleration voltage. Thereby, the SiOx film (0<=x<2) is formed to desired thickness at any position of the interface between the SiO2 film and the base material with good reproducibility.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a packaging film, and more specifically, it has excellent gas barrier properties such as moisture proofing, fragrance retention, and prevention of #I formation, and is heat resistant. The present invention also relates to a method for mass producing a colorless and transparent packaging film with high strength and flexibility with good productivity.

[Conventional technology] In recent years, with the spread of microwave ovens in households, the market for food packaging materials based on a base material made of flexible plastic film that can be distributed at room temperature and can be used in microwave ovens along with the packaging material has expanded. There is. Characteristics required for food packaging films include: ■ Excellent gas barrier properties such as moisture resistance, aroma retention, and antioxidant properties; ■ Sufficient strength and flexibility; ■ Applicability to heat and pressure sterilization. ,and so on.

Conventionally, as a material that satisfies the above characteristics, a flexible plastic film is used as a base, a film of metal oxide such as aluminum oxide, #I magnesium oxide, silicon oxide, etc. is formed on the surface of this film, and other films are laminated on the film-formed surface. A packaging film and a method for manufacturing the same have been proposed (see JP-A-58-148759, JP-A-1-206036, JP-A-1267036, and JP-A-2-34330).

In particular, packaging films made with silicon oxide have excellent water resistance, so there is little deterioration in gas barrier properties before and after retort sterilization, or due to environmental changes in which packaging materials and foods are placed, making them suitable as packaging materials that meet the above characteristics. It is being used. In most cases, a vacuum evaporation method is used to form a silicon oxide film in order to increase productivity and reduce costs.

(Problems to be Solved by the Invention) However, when using a silicon oxide thin film layer, 1,500 to 2,000 people are required to form the silicon oxide thin film if it is to have gas barrier properties that can be stored at room temperature for a long period of time. However, the cost is high.

■ Cracks tend to occur in the film when bent, causing problems in gas barrier properties and adhesion. Therefore, its use is limited to packaging forms that can avoid folding, such as standing pouches.

■ SiO created by vapor deposition using SiO as a raw material
Although the X layer is transparent, it is colored pale yellow, so it looks bad and is not suitable as a food packaging material. 0.0% during deposition of SiO. Although it is possible to obtain a colorless and transparent SiC2 film by introducing a gas, a film with sufficient barrier properties cannot be obtained as described in (2). In addition, when 5iOz is used as a raw material, a colorless and transparent 5iOzll can be formed by vacuum evaporation, but the vapor pressure is low and the evaporation rate is slow, making it unsuitable for large areas and mass production such as packaging films.

The following shortcomings remained unresolved.

In order to solve these drawbacks, we have filed a patent application for a packaging film characterized by having a SiOx layer (0≦X×2) intermingled with the base material structure at the interface between the SiO2 film and the flexible plastic film. was done first. The S i OX layer (0≦χ<2
), for example, vacuum evaporation is performed using SiO as a raw material, and at the same time Ar plasma is generated using high frequency waves to provide energy so that the film-forming particles bite into the base material structure. ≦X〈2), while S
In a method for producing an iO□ film, for example, when forming a film using a vacuum evaporation method using SiO as a raw material, 0□ gas is usually introduced into the atmosphere in order to increase the degree of oxidation.

In addition, in order to improve the film quality, 0! A possible method is to generate a plasma in a gas atmosphere and form a film.

[Problems to be Solved by the Invention] As a method for producing packaging films, it is desirable to use a method that can be produced uniformly over a large area and with high productivity at low cost because of its use as a packaging material. Specifically, a continuous method is preferred. It is suitable if it can be manufactured using a winding vapor deposition apparatus.

However, the packaging film has a SiOx layer (0≦X<2
) and Si0g film, with a SiO++ layer (0≦
In order to manufacture X<2), it is not enough to vacuum-deposit SiOw, and it is necessary to impart energy to the SiOx film-forming particles by some method so that they can penetrate into the base material structure. As mentioned earlier, using high frequency, A
In the method of generating 'r plasma and imparting energy to the SiOx film-forming particles, it is necessary to
≦X<2) and a vacuum chamber for forming the SiO□ film must be provided separately. Because, Sin, layer (0≦X〈
This is because 2) and Sin, the atmospheric pressure for forming the film, and the type of gas used are different. Therefore, the equipment becomes large and complicated, and the cost is high.Also, the method of imparting energy to the film-forming particles in the plasma is difficult due to the characteristics of the plasma.
It is difficult to maintain its stability and reproducibility, and it is difficult to uniformly produce a SiOx layer over a large area with good reproducibility.

Thus, in order to utilize the packaging film as a packaging material, it is important to establish a method for manufacturing it in large quantities with good productivity and without impairing its excellent properties.

The present invention provides a method for mass-producing a colorless and transparent packaging film that has excellent gas barrier properties such as moisture proofing, fragrance retention, and antioxidant properties, and has high heat resistance, strength, and flexibility, and is highly productive. It is.

[Means to solve the problem]

That is, the present invention was made in order to solve the problems that existed in the past, and includes a layer of Sin mixed with the structure of the base material on at least one side of a base material made of a flexible plastic film. (0≦X<2)
, SiO□ films are sequentially laminated to produce a packaging film, in which a 5-inch film is first formed on at least one side of a base material made of a flexible plastic film, and then 5 iOzl! 5iOx (0≦X
By implanting <2) as a beam, the 5iC) + layer (0≦X2) is mixed with the structure of the base material.
) by devising a method to obtain the above problem.

[Effect]

The method for producing a packaging film according to the present invention involves forming a layer of S i O (0≦x<2
), an ion source is used to obtain SiO++ (0≦X〈2
) is used as a beam to implant Sin from the film surface, thereby uniformly depositing a SiOx layer (0≦X<2) at any position and thickness on the interface between the Si0g film and the base material over a large area. , can be manufactured with good reproducibility. Therefore,
Moisture proof.

It becomes possible to obtain a colorless and transparent packaging film in large quantities with good productivity, which has excellent gas barrier properties such as aroma retention and antioxidant properties, and has high heat resistance, strength, and flexibility.

[The method for producing a packaging film according to the detailed description of the invention will be described in detail below.

As mentioned above, the packaging film produced by the production method of the present invention has a SiOx layer (0≦X <2), 5
The flexible plastic film that is the base material used in the present invention has a two-layer structure in which iOt films are sequentially laminated. Examples include films made of olefin resins such as polymers, polyesters such as polyethylene terephthalate and polyethylene terephthalate, nylon, polyvinyl chloride, polyvinylidene chloride, and polyvinyl alcohol. These films may be manufactured by any method, and may be unstretched or stretched, and the thickness of the substrate may be 5 to 1000 mm.
It is preferable to choose within the range of μm, especially 10 to 100 μm.
A range of is preferred.

The method of producing SiO□ film on the base material is sputtering method, CV
The D method, vacuum evaporation method, etc. are mentioned, but the vacuum evaporation method is preferable from the viewpoint of reducing costs for packaging materials and increasing productivity.The evaporation source in the vacuum evaporation method is resistance heating method, EB method, etc. , induction heating method, etc., but any method can be applied. Raw materials for producing SiO□ films are better if they have a high vapor pressure;
O is suitable. At that time, the degree of oxidation is increased to produce colorless and transparent Sin.
, in the atmosphere to obtain a film. It is also possible to obtain a dense, colorless and transparent SiO film by introducing a gas or by irradiating the deposition surface with an oxygen ion beam generated using an ECR ion source or the like at the same time as SiO deposition. S
If the O/Si ratio of the SiO film is 2, the film will be colorless and transparent, so any method that can produce a film with such a composition is not particularly limited. Although the thinner the thickness, the more the manufacturing cost is reduced, but the more the gas barrier property is deteriorated. Like conventional packaging film, 5iOzll! is applied to the base material! When forming a film, it is usually formed with a thickness of about 1,500, but the gas barrier property is not sufficient. In the packaging film of the present invention, Sin.

Good gas barrier properties are maintained even when the film thickness is 1500 Å or less, and preferably the thickness of Sin and Ill is 500 to 120 Å.
The range is 0 people.

Now, after preparing the Si film in this way, Si is added to the interface between the flexible plastic film and 5iOzlK.
n, layer (0≦X<2) is created, but in order to do so, 5iOx (0≦X<2) is ionized using an ion source and the amount of ion extraction and its acceleration voltage are controlled. 5iOx (0≦X<
2) Ion beam implantation is the best method. The type of ion source used is one that can vaporize 5iOx (0≦X<2) or ionize it into atomic or molecular form.

Examples include electron impact ion sources, liquid metal ion sources, beam plasma ion sources, hot cathode arc discharge ion sources, microwave ion sources, and PIG ion sources.

Among these, the Freeman type ion source, which is one of the PTG type ion sources, is particularly suitable for the manufacturing method of the present invention because it can obtain band-shaped ions with a large current. It can be used in the manufacturing method of the present invention by installing a plurality of ion sources in the width direction of the flexible plastic film to be manufactured, or by processing the shape of the outlet of the ion source. The method for producing the S i O++ (O≦X2) layer is as follows: S i Ox (
0≦X<2) is SiO! This is not the case if the method can control the energy and amount of implantation so that it penetrates through the film into the base material structure and creates a mixed layer of the S i OX (0≦x<2) layer and the base material.

The thickness of the 5iOx (0≦x<2) layer can be arbitrarily controlled by the amount of current of the SiOx ion beam extracted from the SiO and ion source. Further, the position at which the SiOx layer is formed can be arbitrarily determined by controlling the implantation depth using the accelerating voltage of the SiOx ion beam.

Note that the thickness of the 5iOx (0≦X<2) layer requires at least about 10 layers in order to achieve the desired gas barrier properties. Moreover, if the thickness of the 5iOx (0≦X<2) layer is too thick, colorless transparency will be lost, so it is preferable to set the thickness in the range of 50 to 100.

〔Example〕

An embodiment of the method for producing a packaging film according to the present invention will be described in detail with reference to FIG. In FIG. 1, 1 is a continuous winding vapor deposition device, 3 is an electron impact ion source, 5 is a resistance heating evaporation source, 7 is a substrate, and 9 is SiO.

FIG. 1 shows a film forming apparatus in which an electron impact ion source is incorporated into a continuous winding vapor deposition apparatus. The evaporation source is a resistance heating type. As a base material, a PET film with a thickness of 12 μm (
First, 0! 1,100 people deposited SiOx films using the gas reaction vapor deposition method. The atmospheric pressure during film formation was 2.5 x 10-'To, rr, P E
The T film winding respeed was 350 m/nin. As the evaporation material, 5iO (5 to 10 mesh manufactured by Osaka Titanium Co., Ltd.) was used.

Next, using an electron impact ion source, SiO was used as the raw material, and the ionization electron current was 500 mA.
By implanting an ion beam into the surface of the SiOz film at an accelerating voltage of 40 kV, the Si layer was
Man-made. Sin.

Three of the same ion sources were used in parallel so that the ion beam irradiation shape was wide and uniform in a band shape in the width direction of the PET film.

The structure of the packaging film produced in this way was measured by photoelectron spectroscopy.The procedure was to perform Ar ion beam etching in the film thickness direction from the film surface toward the base material, and then in the depth direction. ESCA spectrum (S
l! P, CIS+ ops) were measured. As a result, it was found that 5i
-0 bond exists and S i O! It was found that the membrane was successfully produced. Furthermore, a spectrum indicating the presence of 5i-3i bonds appeared in the SiOx layer produced by implanting a SiOx ion beam. The X value of the SiOx layer is 1.7
Met.

Furthermore, in a similar measurement when the base material PET was exposed, CIS indicating the presence of PET and 5jzr spectrum indicating the presence of Si appeared simultaneously. As a result, it was found that at the interface between the base material and the 5iOx layer, both structures were present in a mixed state, and from the position of the 5izr spectrum peak, it was found that a 5i-3i bond was present.

The oxygen permeability of the packaging film produced in the above process was measured in an oxygen atmosphere at 25°C and 100% RH. In addition, the transmittance of light was measured using a spectrometer. The measurement wavelength range is 190 μm to 700 μm. The measurement results are shown in Table 1.

[Example 2] Using the same base material as in Example 1, the same method as in Example 1 was applied on it: 50 people deposited the SiO1 layer (X=1.7), and 1150 people deposited the SiO□ film. Created. The oxygen transmittance and light transmittance of the above packaging film were measured in the same manner as in the examples. The measurement results are shown in Table 1.

(Comparative Example 1) Using the same base material as in Example 1 and using the same method as in Example 1, 1200 people produced SiO□ films.

The oxygen transmittance and light transmittance of the above packaging film were measured in the same manner as in the examples. The measurement results are shown in Table 1.

[Comparative Example 2] Using the same base material as in Example 1, 1200 Sin layers were produced in the same manner as in Example 1.

The oxygen transmittance and light transmittance of the above packaging film were measured in the same manner as in the examples. The measurement results are shown in Table 1.

(The following is a blank space) Table 1 [Effects of the invention] In the packaging film manufacturing method of the present invention, SiO++
By using an ion source to prepare the (0≦X<2) layer, it became possible to arbitrarily control the energy and implantation amount given to the SiO2 (0≦X<2) particles. therefore,
It became possible to produce a SiO++ (0≦X<2) layer at any position on the interface between the S40g film and the base material and at any thickness with good reproducibility. Furthermore, by adjusting the installation position and number of ion sources, it became possible to uniformly produce a 5iOx (0≦X<2) layer on a wide film surface. In addition, simply by installing an ion source in a continuous winding type vapor deposition apparatus, it is possible to continuously produce a SiOx (0≦x<2) layer and a SiOz film in the same vacuum chamber, making it possible to reduce the structure of the apparatus. Another advantage is that it is simple and does not require much effort.

By using the packaging film production method of the present invention, a colorless and transparent packaging film that has excellent gas barrier properties such as moisture resistance, fragrance retention, and antioxidant properties, and has high heat resistance, strength, and flexibility can be produced in large quantities at a low cost. It has become possible to produce with good reproducibility.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the method for producing a packaging film according to the present invention. l...Continuous winding vapor deposition device 3...Electron impact ion source 5...Resistance heating type evaporation source 7...Substrate 9...SiO Patent application Representative of Toppan Printing Co., Ltd. Kazuo Suzuki Diagram

Claims (1)

[Claims] (1) On at least one side of the base material made of a flexible plastic film, a SiO_x layer (0≦X<2), an S
A method for manufacturing a packaging film in which iO_2 films are sequentially laminated, the method comprising: after forming a SiO_2 film on a flexible plastic film, converting the SiO_x into an ion beam using an ion source to separate the SiO_2 film and the flexible plastic film from the surface of the SiO_2 film. A method for producing a packaging film characterized by applying the film to the interface of the packaging film.