JPH06285945A - Production of clean film for packing - Google Patents

Abstract

PURPOSE:To efficiently obtain a clean film for packing perfectly prevented from the adhesion of waste, refuse and dust, requiring no washing and excellent in packing material strength and capable of easily imparting desired function such as pinhole resistance or gas barrier properties. CONSTITUTION:Coating films 4 each composed of at least two thermoplastic resin films 4a, 4b are applied to both surfaces of a heat-resistant base material 2 by co-extrusion to produce a packing clean film 1 wherein the clean surfaces of the inside thermoplastic resin films 4a are exposed by peeling and removing the outermost thermoplastic resin films 4b of the coating films 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a clean film for packaging, and more specifically, for example, semiconductor products produced in a clean environment such as a clean room or clothes required for producing such products. The present invention relates to a method for producing a clean film for packaging, which is preferably used for packaging.

[0002]

2. Description of the Related Art Semiconductor products such as ICs and LSIs are manufactured in a clean room because they extremely dislike dust and dust. Further, it is required that dust and dirt do not adhere to a product manufactured under such a clean environment or a packaging material used for packaging clothes and the like which are required at the time of manufacturing such a product.

Therefore, conventionally, a packaging material manufactured in a clean room and washed with ultrapure water has been used as a packaging material used in a clean environment. On the other hand, a multilayer film formed by co-extrusion is drawing attention as such a clean film for packaging.

This multilayer film is formed by coating both sides of an intermediate layer film with an outer layer film which can be peeled off and removed. When the outer layer film is peeled off, a clean surface of the intermediate layer film which directly wraps an object to be packaged. Is exposed.

[0005]

However, in the conventional packaging materials, it is necessary to further wash the products manufactured in a clean room with ultrapure water, and this cleaning process is intended to reduce the manufacturing cost. However, there is a problem in that the degree of cleanliness is insufficient due to the degree of cleaning with ultrapure water.

The multi-layer film produced by co-extrusion is
Although washing with ultrapure water is unnecessary, the packaging material strength of the intermediate layer film used as a packaging material is not always sufficient, and the intermediate layer film is provided with desired functions such as pinhole resistance and gas barrier property. There is a problem that is difficult.

The present invention has been made under such circumstances, and an object of the present invention is that the adhesion of dust and dust is completely prevented, cleaning is unnecessary, and the strength of the packaging material is excellent and the durability is high. It is an object of the present invention to provide a method for producing a clean film for packaging, which can easily impart desired functions such as pinhole property and gas barrier property.

[0008]

Means for Solving the Problems The constitution of the present invention for achieving the above object is to provide at least 2 on both sides of a heat resistant substrate in a method for producing a packaging clean film in which a plurality of resin films are laminated. A coating film made of a thermoplastic resin film of a layer is co-extruded, and the outermost thermoplastic resin film of the coating film is peeled off to obtain a clean film for packaging in which a clean surface is exposed. It is a method for producing a clean film for packaging.

In the method for producing a clean film for packaging of the present invention, a laminate comprising at least two layers of a thermoplastic resin film is coextruded on both front and back surfaces of a heat resistant substrate to form a laminate.

Examples of the heat-resistant substrate to be used include stretched nylon (ONy) film, stretched nylon film with vinylidene chloride film (KON), polyethylene terephthalate (PET) film, polyethylene terephthalate with vinylidene chloride film (KPET). Film, ethylene / vinyl acetate alcohol saponified (EVOH) film, polyvinylidene chloride (PVDC) film, aluminum foil, inorganic oxide deposited PET, aluminum deposited PE
Suitable examples include T and the like. Among these, biaxially stretched nylon (ONy) film, biaxially stretched P
ET films are particularly preferred.

The thickness of the heat-resistant base material varies depending on the characteristics of the heat-resistant base material, the type of the article to be packaged, etc., so that it is difficult to determine the thickness uniformly. 30 μm
It is a degree.

If desired, one or both surfaces of this heat resistant substrate can be printed. In the method for producing a clean film for packaging of the present invention, then, a coating film comprising at least two layers of a thermoplastic resin film is directly or preferably on both sides of the heat resistant substrate directly or preferably via an anchor coat layer. Extrude together.

The above-mentioned anchor coat layer prevents the coating film from peeling from the interface with the heat resistant substrate, and is the outermost layer film of at least two layers of the thermoplastic resin film constituting the coating film. It is a layer that has the function or function of ensuring that only one is peeled and removed.

The anchor coat layer having such an action or function can be formed by applying an anchor coat agent on both front and back surfaces of the heat resistant substrate. here,
Examples of the anchor coat agent include polyethyleneimine-based, titanate-based, urethane-based, and isocyanate-based anchor cart agents.

When the anchor coat layer is formed, its thickness is usually about 0.3 to 3 μm, preferably about 0.5 to 1.5 μm. In the method for producing a clean film for packaging of the present invention, a coating film made of at least two layers of thermoplastic resin film is prepared by co-extrusion. For example, when the coating film is made of two layers of thermoplastic resin film, Regarding the thermoplastic resin to be co-extruded, for example, polyethylene (PE) / polypropylene (PP), polyethylene (P) may be used in combination of (heat-resistant substrate side film forming resin) / (outermost layer film forming resin).
E) / nylon (Ny), polyethylene (PE) / polyethylene terephthalate (PET), polyethylene (P
E) / Saponified ethylene / vinyl acetate alcohol (EV
OH) and the like are mentioned as preferable ones, and an appropriate combination may be selected according to a desired function such as pinhole resistance and gas barrier property.

Such a coating film can be formed, for example, by co-extrusion by the T-die method, by extruding two or more kinds of thermoplastic resins in a molten state from an extruder. Here, the co-extrusion temperature cannot be uniformly determined because it depends on the combination of the thermoplastic resins, but, for example, polyethylene (PE) / nylon (N
In the case of the combination of y), it is usually 290 ° C or lower, preferably 240 ° C or lower. This co-extrusion temperature is 300
If the temperature exceeds ℃, the peelability of the nylon film forming the outermost layer may be poor.

As shown in FIG. 1, the clean film 1 for packaging produced as described above has at least 2 directly on both sides of the heat-resistant substrate 2 with or without the anchor layer 3 interposed therebetween. Layer of thermoplastic resin film 4
The coating film 4 composed of a and 4b is co-extruded. Here, since at least two layers of the thermoplastic resin films 4a and 4b constituting the coating film 4 are laminated by coextrusion, the surface of the inner thermoplastic resin film 4a is produced both during and after production. Does not come into direct contact with the outside air, and therefore dust, dust, etc. do not adhere to the surface of the thermoplastic resin film 4a between the time of manufacturing and the time of use.

That is, as shown in FIG. 2, the outermost layer of the thermoplastic resin film 4b was peeled and removed to be covered with the thermoplastic resin film 4b, and the adhesion of dust, dust, etc. was completely prevented. The clean surface of the inner thermoplastic resin film 4a appears, and the thermoplastic resin film 4a can be suitably used as it is, for example, as a packaging material for an article to be packaged that requires high cleanliness such as semiconductor products.

The peel strength of the outermost thermoplastic resin film 4b in the at least two layers of the thermoplastic resin film constituting the coating film 4 impairs the function of coating the surface of the inner thermoplastic resin film 4a. Unless smaller, the smaller the better. When the peel strength is increased, the amount of static electricity generated on the surface of the inner thermoplastic resin film 4a when the outermost thermoplastic resin film 4b is peeled and removed is increased, whereby the dust collecting property of the surface of the film 4a is increased. This is because dust and dust are likely to adhere to the surface.

[0020]

EXAMPLES Next, examples of the present invention will be shown to explain the present invention more specifically. (Example 1) A stretched nylon (ONy) film having a thickness of 15 μm (“Emblem ON” manufactured by Unitika Ltd., density 1.1)
Gravure printing was performed on the surface of 5), and this was used as a heat resistant substrate.

Next, a urethane-based anchor coating agent (“ADCO” manufactured by Toyo Morton Co., Ltd.
AT506X / CAT10 ") to a thickness of 1.0
A μm anchor coat (AC) layer was formed.

Next, on this anchor coat (AC) layer, polyethylene (PE) (manufactured by Nippon Unicar "NUC"
8160 ", density 0.923, MI = 2.4 g / 10
Min) and nylon (Ny) (Ube Industries, Ltd. "5033"
B ", density 1.14) is co-extruded on the anchor coat (AC) layer side so that a polyethylene (PE) layer is formed to provide a coating layer composed of a polyethylene film and a nylon film. A clean film for packaging was created.

Ny 20μ / PE 40μ / AC / ONy 15μ /
Printed layer / AC / PE 40μ / Ny 20μ Then, the tensile strength of the packaging material film after peeling and removing the outermost nylon film of this packaging clean film was measured. The results are shown in Table 1.

[0024]

[Table 1] The tensile strength was measured as follows. Tensile strength: Tensile strength was measured using a tensile tester (Tensilon) under conditions of a tensile speed of 300 mm / min and an angle of 180 °. (Comparative Example 1) Nylon (Ny) was produced by a known extrusion method.
(Ube Industries, Ltd. "5033B", density 1.14) and polyethylene (PE) (PE) (Nippon Unicar "N"
UC8160 ", density 0.923, MI = 2.4g / 1
0 minutes) was coextruded to prepare a three-layer coextrusion laminated film having the following layer constitution.

Ny30μ / PE60μ / Ny30μ Then, the tensile strength of this three-layer coextruded laminated film was measured in the same manner as in Example 1. The results are shown in Table 1. (Study of Results) As is clear from Table 1, the packaging clean film produced in Example 1 has a higher tensile strength than the three-layer coextrusion laminated film produced in Comparative Example 1. From this, it was confirmed that according to the production method of the present invention, a packaging clean film was obtained in which dust, dust, etc. were not easily attached to the exposed surface and was excellent in dust-free property, and the strength was significantly improved. .

[0026]

As described in detail above, according to the present invention, a coating film composed of at least two layers of thermoplastic resin film is coextruded on both the front and back surfaces of a heat-resistant base material to form a coating film. Since the clean film for packaging is manufactured so that the clean surface is exposed when the outermost layer film is peeled off, the packaging material strength such as tensile strength is improved, and it is also dust-free and has pinhole resistance. Provided is a method for producing a clean film for packaging, which is easy to impart desired functions such as properties and gas barrier properties.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the layer structure of a clean film for packaging obtained by the production method of the present invention.

FIG. 2 is an explanatory view showing a state in which an outer layer film is peeled off in the packaging clean film shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Clean film for packaging 2 ... Heat resistant base material 4 ... Covering layer 4a, 4b ... Thermoplastic resin film

Claims (1)

[Claims] 1. A method for producing a clean film for packaging, comprising laminating a plurality of resin films, wherein a coating film comprising at least two layers of a thermoplastic resin film is coextruded on both front and back surfaces of a heat resistant substrate, A method for producing a packaging clean film, which comprises obtaining a packaging clean film having a clean surface exposed by peeling and removing an outermost thermoplastic resin film of a covering film.