JPH084283Y2 - Laminate for packaging - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial application] The present invention has excellent gas barrier properties against oxygen gas, carbon dioxide gas, etc., water vapor barrier properties, flexibility, water resistance and chemical resistance, and can be used under various severe environments. A useful silicon oxide that has stable performance, is clean to the environment in various situations in the field of packaging materials such as foods and drinks, pharmaceuticals, and favorites, and has a gas barrier property against oxygen, water vapor, etc. The present invention relates to a packaging laminate including a dry plating layer, which is essential.

[0002]

2. Description of the Related Art Plastic laminates used in the field of packaging materials such as foods, drinks, pharmaceuticals, favourites, and electronic parts are permeable to gas such as water vapor and oxygen in order to prevent deterioration of the packaged contents. A material with a low rate is used. Further, recently, there is an increasing demand for safety of the global environment such as convenience in disposal and recycling. However, a barrier film containing chlorine molecules such as PVDC (polyvinylidene chloride) has a gas barrier property against oxygen, water vapor, etc., but due to the generation of chlorine ions during combustion, the generation of toxic substances or acid rain. The use of these films has recently become a hot issue. Further, polyvinyl alcohol films and polyvinyl alcohol films such as ethylene-vinyl alcohol copolymer films are also widely used as packaging materials because they have excellent oxygen barrier properties. When burned, these films do not generate toxic gases that harm the environment. However, the polyvinyl alcohol-based film is inferior in water vapor barrier property and further has a defect that the oxygen barrier property is deteriorated under the condition of high humidity.

In the case of a packaging material which requires a higher gas barrier property, a film in which an aluminum foil is attached or a film in which aluminum is vapor-deposited has been used. However, although a packaging material using such a metal foil has excellent gas barrier properties against water vapor, oxygen, etc., it has a problem in acid resistance and alkali resistance, so that the pH of the environment in which the content or laminate is used ( The range of use of the packaging material using a metal foil or the like is limited by the hydrogen ion concentration). In addition, packaging materials containing metal foil, etc. are melted at the time of combustion after disposal, and the metal foil etc. is melted, and metal is deposited on the bottom part of the combustion furnace, blocking the air holes and ash extraction holes of the combustion furnace, This is a problem because it may damage the refractory material. On the other hand, in the field of plastic laminate packaging materials, there is no pollution due to the work environment during coating and the fact that there is no concern about residual solvents as packaging materials.
Some highly safe aqueous coatings have been put to practical use. However, coating of a water-based coating agent on a plastic film that has not been subjected to any special treatment has not been widely used because of poor coating due to insufficient wettability and insufficient adhesive strength. This is because many plastic films are hydrophobic, and even if an aqueous coating is applied onto the plastic film, they do not get wet uniformly. Therefore, when a plastic film is coated with an aqueous coating agent, corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment is performed only for the purpose of improving the wettability of the film surface and the adhesion between the film and the aqueous coating agent. However, it is practically used to some extent by applying surface treatment such as surface roughening treatment, known anchor coat treatment, surface treatment such as easy adhesion treatment, and treatment such as coating of modifier to the plastic film. is there.

[0004]

[Problems to be Solved by the Invention] The present invention provides a surface of a plastic film by adding silicon oxide.
In addition to improving the wettability of the surface and improving the coatability and adhesiveness with water-based coating agents, the usable range of water-based coating agents has been expanded, making it better than organic solvent-based coating agents. The object of the present invention is to provide a clean laminated body that creates a working environment, has no residual solvent, does not release chlorine ions and the like even when incinerated, and is clean to the environment. Moreover, by using a dry coating layer that essentially requires silicon oxide as a gas barrier layer, it not only has excellent acid and alkali resistance, but also exhibits excellent gas barrier properties against water vapor, oxygen, etc. under high temperature and high humidity conditions. By applying an aqueous coating agent to the dry coating layer under conditions such as ordinary printing and dry lamination, a gas barrier property is further improved as compared with a solvent type coating agent.

[0005]

The present invention is a plastic film having at least one dry coating layer containing silicon oxide as an essential component, wherein the dry coating layer is coated or printed with an aqueous coating agent. It is a laminate for packaging. In the present invention, the plastic film is not particularly limited, and polyethylene terephthalate,
Polybutylene terephthalate, polyethylene-2,6-
Films made of polyester such as naphthalate, polyamide, polyimide, polyacrylonitrile, polycarbonate, polystyrene, polypropylene, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, aromatic polyamide, fluororesin, etc., or one of these or There are laminated films containing two or more,
It may be uniaxially stretched or biaxially stretched. In general packaging applications, biaxially oriented polypropylene film, polyester film and the like are preferably used in terms of gloss and strength, and in the electronic material field, fluororesin film and polyester film are used. Further, in the case of producing by the winding method, the thickness of the plastic film is preferably 5 to 100 μm from the viewpoint of preventing generation of stretch wrinkles, cracks and the like.

The method for forming a laminate according to the present invention is as follows. First, a dry coating layer containing silicon oxide as an essential component is formed on at least one surface of a plastic film as a base material. This dry coating layer not only improves the wettability of the plastic surface, but also imparts a gas barrier function such as oxygen and water vapor to the finally obtained film. The method for forming the dry coating layer containing silicon oxide as an essential component on the plastic film is not particularly limited, and vacuum vapor deposition, ion plating, sputtering, plasma CVD or the like is used. Furthermore, the heating method for vacuum vapor deposition is not particularly limited, and conventionally known heating methods such as high frequency induction heating, resistance heating, radiant heating, and electron beam heating can be used. The thickness of the thin film of silicon oxide is selected according to the thickness of the film substrate used and the purpose of use of the finally obtained film.
The range of 5000Å is desirable, preferably 200Å to 1
000Å is desirable. Next, an aqueous coating agent is applied or printed on the dry coating layer containing silicon oxide as an essential component. Examples of the water-based coating agent include a water-based adhesive agent, a water-based anchor coating agent, a water-based coating agent, a water-based gravure ink, and the like, which may have heat sealability and easy adhesion. The main solvent of these water-based coating agents may be water when used, and resins such as adhesives, anchor coating agents, coating agents and printing inks are not particularly limited. Further, the aqueous coating agent may partially contain an organic solvent such as alcohol. As the water-based coating material, a polyester-based coating material is preferable in consideration of recycling and combustion.

The coating amount of the water-based coating agent is not particularly limited, and there is no problem as long as an adhesive, an anchor coating agent, a coating agent, a printing ink, etc. are generally used. As a method of applying the water-based coating agent to a plastic film having a dry coating layer containing silicon oxide as an essential component, gravure coating, reverse coating, spray coating and the like can be considered, but the methods are not limited to these. is not. Further, there is no problem as long as the coating speed and the drying means are within the normally used range. The thickness of the aqueous coating agent is usually 1 to 10 μm.

There is no particular limitation on the method of providing a dry coating layer on a plastic film, coating or printing an aqueous coating agent on the dry coating layer, and laminating one or two or more layers of the plastic film on it, without any particular limitation. Conventionally known laminating methods such as extrusion laminating, thermal laminating and thermal laminating can be used. The plastic film laminated on the water-based coating material is not particularly limited, and polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,
Polyester such as 6-naphthalate, polyamide, polyimide, polyacrylonitrile, polycarbonate,
Polyolefin such as polystyrene, polyethylene, polypropylene, saponified ethylene-vinyl acetate copolymer,
There are films made of polyvinyl alcohol, aromatic polyamide, fluororesin, etc., or laminated films containing one or more of these, and may be uniaxially or biaxially stretched. Further, one or two or more plastic films may be laminated in the same manner also on the plastic film side provided with the dry coating layer containing silicon oxide as an essential component. The reason why the gas barrier property is further improved by coating or printing an aqueous coating agent on the dry coating layer is that the dry coating layer containing silicon oxide as an essential component is an aqueous coating agent. By coating or printing on, the water adsorbed to the surface of the thin film of silicon oxide and the fine pores formed in the thin film reacts, and the fine pores formed in and on the thin film of the silicon oxide are closed. Since it has a structure, it becomes a structure in which oxygen and water vapor are extremely difficult to permeate, and it is considered that each barrier property of oxygen and water vapor is excellent.

[0009]

[Effects of the Invention] The laminate obtained by the present invention is provided with a dry coating layer containing silicon oxide as an essential component on a plastic film to improve the wettability, thereby improving the coating suitability and, as a result, the aqueous coating. The agent can be used, and the surface modification treatment only for improving the adhesiveness is unnecessary.
Also, since no organic solvent is used, the laminating work environment,
Not only will the work environment such as the printing work environment be clean, but the residual solvent in the laminate will be almost eliminated.
The laminated body can be substantially composed of a polyester resin layer, there is no confusion during the disposal process, and chlorine ions are not generated even when incinerated. In addition, by coating the dry coating layer with an aqueous coating agent, the gas barrier properties of oxygen, water vapor, etc. are further improved.
It is possible to provide a highly barrier laminate for high barrier packaging, which does not need to be coated with water. This laminate can be used for pouches, tray lid materials, general packaging such as gusset packaging and tobacco packaging. Further, there is an advantage that the functions such as improvement of barrier property and printing and adhesion with other film can be performed by one treatment. For example, when the plastic film used as the substrate has a heat seal on one side in advance, a barrier film having heat seal layers on both sides can be obtained by one-time application or printing. As a method for forming the heat-sealing layer previously provided on this substrate, coextrusion multilayer biaxial stretching may be used, or in-line or off-line coating before and after film stretching may be used. Furthermore, in the case of tobacco packaging materials, PV that is conventionally used
Not only the flavor barrier performance such as L menthol is improved as compared with the DC coated polypropylene film, but the amount of the flavor component adsorbed to the resin is small, so that it can be stored for a long period of time without impairing the flavor of tobacco. In particular, when the heat seal layer on the inner surface of the bag is made of polyester, the amount of flavor component adsorbed on the resin can be reduced. Further, since the laminate is transparent, there is an advantage that printing on the bag is unnecessary.

[0010]

EXAMPLES The present invention will now be described in more detail based on the examples of the present invention, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. The measurement of each characteristic in the examples is based on the following measuring methods. Oxygen gas permeability According to ASTM D-3985, it measured on the conditions of 25 degreeC and 100% RH (humidity) using the oxygen gas permeability meter (Modern Controls OXTRAN-100). Water vapor transmission rate According to ASTM F-1249, water vapor transmission rate measuring instrument (PERMATRAN-WT
WIN) was used under the conditions of 40 ° C. and 90% RH. Heat-sealing strength: 15 mm width, T-shaped peeling, 300 mm / min for the laminated body heat-sealed under the conditions of 120 ° C., 1 Kg / cm ² , and 1 second.
Was measured. The heat-sealing was performed on three points, that is, the heat-sealing layer of the base polyester, the heat-sealing layer of the base polyester and its opposite surface, and the opposite surface. Residual solvent amount Put the obtained laminated body 10 × 30 mm in a sealed container,
After heat treatment for 30 minutes, the amount of solvent was measured by gas chromatography.

Example 1 12 μm thick biaxially stretched polyethylene terephthalate (P
Silicon monoxide was heated and vacuum-deposited on the surface of the (ET) film by a high frequency induction heating method to form a thin film of silicon oxide of about 1000 liters. A water-based gravure ink, Akwacolor R63F white (manufactured by Toyo Ink Mfg. Co., Ltd.) was coated on this vapor-deposited film at a coating amount of about 2 g / m ² (dry) at a speed of 100 m / min using a gravure coater, and water-based adhesive was further applied onto it. Agent AD-610A / AD-610C (manufactured by Toyo Morton Co., Ltd.) was applied at a coating amount of about 2.5 g / m ² (dry) at about 100 m / min using a gravure coater, and a linear low-density polyethylene film 60 μ and dry. Laminated. A partially enlarged sectional view of the obtained laminated body is shown in FIG. 1
Is a plastic film, 2 is a dry coating layer, 3 and 4 are aqueous coating layers, and 6 is a plastic film to be further laminated. Regarding the obtained laminate,
The oxygen gas permeability and the water vapor permeability were measured by the above method. Also, the adhesive strength between the dry coating layer 2 and the water-based ink 3 is 15 mm wide, T-shaped peeling, peeling speed 300 mm / mi
It was measured under the condition of n. Further, 0.2 m ² of the obtained laminate was placed in a sealed container, heat-treated at 80 ° C. for 30 minutes, and a test for residual solvent was conducted by gas chromatography. The results are shown in Table 1.

[0012]

[Table 1]

Example 2 A water-based adhesive AD-6 was added to the vapor-deposited film obtained in Example 1.
10A / AD-610C (manufactured by Toyo Morton Co., Ltd.) with a coating amount of about 2.5 g / m ² (dry) using a gravure coater
It was applied at 100 m / min and dry laminated with 60 μm of a linear low density polyethylene film. A partially enlarged cross section of the obtained laminate is shown in FIG. Oxygen gas permeability and water vapor permeability of the obtained laminate were measured by the methods described above.
Table 1 shows the measurement results.

Example 3 A water-based heat sealing agent THW-3287 (manufactured by Toyo Morton Co., Ltd.) was coated on both sides of the vapor-deposited film obtained in Example 1 by a take-up type dry laminator at about 1 g / m ² (dry). A laminate (FIG. 3) dried at 90 ° C. for 10 seconds was prepared. The oxygen gas permeability and the water vapor permeability of this laminate were measured by the methods described above. The measurement results are shown in Table-1. Further, heat-sealing was performed for 1 second at 120 ° C. and 2 kg / cm ² with the vapor deposition surface side and the vapor deposition surface side of the above-mentioned laminate facing each other. About the laminate, 15mm width, T-shaped peeling, 300
The heat seal strength was measured by mm / min. The measurement results are shown in Table 1.

Example 4 Heat-sealing treatment on one side with a thickness of 15 μm Biaxially stretched polyethylene terephthalate film A non-treated surface was heated and vacuum-deposited with silicon monoxide by a high-frequency induction heating method to about 1000Å.
A thin film of silicon oxide was formed. A water-based heat sealing agent THW-3287 (manufactured by Toyo Morton Co., Ltd.) was applied to the vapor deposition layer side of the vapor deposition film by a winding type dry laminator to about 1
A laminated body (FIG. 4) was prepared by applying g / m ² (dry) and drying at 90 ° C. for 10 seconds. The oxygen gas permeability and the water vapor permeability of this laminate were measured by the methods described above. The results are shown in Table 1. Further, with respect to the above-mentioned laminate, the heat-sealed surface and the coated surface are faced to each other at 120 ° C. 2 kg / cm
² was heat-sealed for 1 second, and the heat-sealing strength was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 12 μm thick biaxially stretched polyethylene terephthalate (P
ET) Water-based gravure ink, Akwacolor R63F white (manufactured by Toyo Ink Mfg. Co., Ltd.) is applied on the surface of the film to be about 2 g.
/ M ² (dry) using a gravure coater at a speed of 10
Printed at 0 m / min, and then water-based adhesive AD6
10A / AD610C (manufactured by Toyo Morton Co., Ltd.) was applied at a coating amount of about 2.5 g / m ² (dry) at a rate of about 100 m / min using a gravure coater, and was dry-laminated with a linear low-density polyethylene film 60 μ (FIG. 5). . Oxygen gas permeability and water vapor permeability of the obtained laminate were measured by the methods described above. The adhesive strength between the PET film 1 and the water-based ink 3 was measured under the same conditions as in Example 1. Table 1 shows the measurement results.

Comparative Example 2 A solvent-based gravure ink ramister R63 white (manufactured by Toyo Ink Mfg. Co.) and a solvent-based adhesive AD308A / AD308B (manufactured by Toyo Morton Co., Ltd.) were used for the vapor-deposited film obtained in Example 1. Laminate by the same method as in Example 1 (Fig. 6)
Was prepared, and the oxygen gas permeability and the water vapor permeability were measured by the methods described above. The residual solvent test was also conducted in the same manner as in Example 1. Table 1 shows the measurement results.

Comparative Example 3 A laminated body (FIG. 7) was prepared on the vapor-deposited film obtained in Example 1 by using the organic solvent adhesives AD308A / AD308B (manufactured by Toyo Morton Co., Ltd.) in the same manner as in Example 2. Then
The oxygen gas permeability and the water vapor permeability were measured by the above method. Table 1 shows the measurement results.

Comparative Example 4 With respect to the vapor deposited film obtained in Example 1, the oxygen gas permeability and the water vapor permeability were measured by the methods described above. The results are shown in Table 1.

Comparative Example 5 In the example described in Example 3, the heat-sealing agent was a solvent type AD-33-DW872 (manufactured by Toyo Morton Co., Ltd.), the drying condition was 150 ° C., 10 seconds, and the heat-sealing condition was 190.
Table 1 shows the results of evaluation of various properties of the laminate (FIG. 8) produced by the same procedure as in Example 1 except that the temperature was 3 kg / cm ² for 1 second.

[0021]

[Brief description of drawings]

FIG. 1 shows a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 2 is a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 3 is a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 4 is a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 5 is a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 6 shows a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 7 shows a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

FIG. 8 is a partially enlarged sectional view of a packaging laminate according to the present invention or a comparative example.

[Explanation of symbols]

 1 Plastic Film 2 Dry Plating Layer 3, 4, 5 Aqueous Coating Layer 6 Laminated Plastic Film 7 Heat Sealing Layer 8, 9, 10, 11 Organic Solvent Coating Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-3-277671 (JP, A) JP-A-3-275778 (JP, A) JP-A-3-259970 (JP, A) Actual development Sho-62- 136562 (JP, U) Ichiro Watanabe "Plastic Materials Course 15 Vinyl Acetate", Nikkan Kogyo Shimbun (August 30, 1964), page 113

Claims (5)

[Scope of utility model registration request] 1. A packaging film comprising a plastic film having at least one dry coating layer containing silicon oxide as an essential component, wherein the dry coating layer is coated or printed with an aqueous coating agent. body. 2. A plastic film having at least one dry coating layer containing silicon oxide as an essential component, wherein the plastic film is laminated on the dry coating layer using an aqueous coating agent. Laminate for packaging. 3. A plastic film having one or more dry coating layers containing silicon oxide as an essential component, wherein a water-based printing ink is applied to or printed on the dry coating layers, and further an aqueous coating agent is used on the outside. A laminate for packaging, which is formed by laminating plastic films. 4. A plastic film having one or more dry coating layers containing silicon oxide as an essential component, wherein an aqueous coating agent is applied or printed on the dry coating layers, and the opposite surface of the plastic film is further coated with an aqueous coating. A packaging laminate, which is obtained by applying or printing an agent. 5. A plastic film having at least one dry coating layer containing silicon oxide as an essential component, wherein the dry coating layer is coated or printed with an aqueous coating agent, and the opposite surface of the plastic film is further coated with an aqueous coating agent. A tobacco packaging laminate, which is obtained by applying or printing an agent.