JP2018178005A - Liquid repellent sealant film, and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant film capable of sufficiently preventing adhesion of ingredients, even when ingredients having high content of a surfactant (e.g. liquid detergent or the like) are housed, by enhancing liquid repellency of a surface.SOLUTION: There is provided a sealant film 10 having a single layer structure or a multilayer structure, having a heat adhesive resin layer 1 in which a fluorine-based additive is blended, in a layer constitution thereof, and the fluorine-based additive is bled out to a sealant film surface. By an action of the bled out fluorine-based additive, high liquid repellency is achieved even to ingredients having high content of a surfactant (e.g. liquid detergent or the like). When these ingredients are housed in a package having the sealant film inside, the ingredients can be fully used without remaining the ingredients inside of the package.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid repellent sealant film and a method of manufacturing the same.

  What has liquid repellency with respect to the contents as a lid material of the container which accommodates contents, such as a yogurt, is well-known (patent document 1). The lid material is a sealant film on which fine liquid repellent particles are attached, and the contents of the lid material are repelled by the action of the liquid repellent particles to prevent the adhesion. When the lid material is heat-sealed in a container, the liquid repellent particles are precipitated on the sealant film by the heat pressure at the time of the heat-sealing.

  On the other hand, there is also known a packaging material in which a fluorine-based additive is mixed with a sealant film and the adhesion of contents is prevented by the function of the fluorine-based additive (Patent Document 2). In this packaging material, not only yogurt but also sauce, soy sauce, ketchup and the like can be contained to prevent adhesion thereof.

Patent No. 5674221 gazette JP, 2015-209242, A

  However, with the contents having a large content of surfactant, these techniques can not sufficiently prevent adhesion. For example, the contents of liquid detergents and the like.

  Therefore, in the present invention, the liquid repellency of the surface is enhanced to sufficiently prevent the adhesion of these contents even when the contents having a large content of surfactant (for example, liquid detergent etc.) are accommodated. To provide a sealant film that can be

That is, the invention according to claim 1 is a sealant film having a single layer structure or a multilayer structure,
A liquid repellent sealant film having a heat-adhesive resin layer containing a fluorine-based additive and having a fluorine-based additive bleeding out on the surface of the sealant film in the layer structure. It is.

The invention according to claim 2 is a sealant film having a multilayer structure,
The layer structure includes a heat-adhesive resin layer containing a fluorine-based additive and a thermoplastic resin layer not containing a fluorine-based additive, and the fluorine-based additive bleeds on the surface of the sealant film A liquid repellent sealant film characterized by being out.

  Next, the invention according to claim 3 is a liquid repellent sealant film according to claim 2, wherein a slip agent is blended in the thermoplastic resin layer not containing a fluorine-based additive. .

Next, the invention according to claim 4 is the liquid repellent sealant film according to any one of claims 1 to 3, wherein the fluorine-based additive has a C 6 perfluoroalkyl group. is there.

  Next, the invention according to claim 5 is characterized in that a fluorine atom occupies 32 to 38 atomic% within a range of 10 nm from the surface of the sealant film. Sealant film.

  Next, invention of Claim 6 melt-extrusion forms the heat bondable resin which mix | blended the fluorine-type additive, and the said fluorine-type addition is carried out by preserve | saving at temperature of 40 degreeC or more for 12 hours or more next. It is a method of producing a liquid repellent sealant film characterized in that the agent is bled out to the surface.

  Next, invention of Claim 7 melt-extrusion forms into a film the thermoadhesive resin which mix | blended the fluorine-type additive, and the said fluorine-type addition is then made to contact the cooling roll of the temperature of 50 degreeC or more. It is a method of producing a liquid repellent sealant film characterized in that the agent is bled out to the surface.

  Next, in the invention according to claim 8, 3 to 7% by mass of a fluorine-based additive is blended with respect to the heat-adhesive resin. The liquid repellent sealant film according to claim 6 or 7 It is a manufacturing method.

  Next, the invention according to claim 9 melt coextrusion forms a thermoadhesive resin containing 2 to 6% by mass of a fluorine based additive and a thermoplastic resin containing a slip agent, and then forms 40 The method for producing a liquid repellent sealant film having a multilayer structure is characterized in that the fluorine-based additive is bled out on the surface by storing at a temperature of at least 8 ° C. for 8 hours or more.

  Next, the invention according to claim 10 forms a melt co-extrusion film of a thermoadhesive resin compounded with 2 to 6% by mass of a fluorine-based additive and a thermoplastic resin compounded with a slip agent, and at 50 ° C. or higher The method is a method for producing a liquid repellent sealant film having a multilayer structure, characterized in that the fluorine-based additive is bled out to the surface by contacting with a cooling roll at a temperature of 1.

  In the sealant film of the present invention, since the fluorine additive bleeds out on the surface, the content of the surfactant is high (for example, liquid detergent etc.) by the function of the fluorine additive. It also exhibits high liquid repellency. Therefore, when the contents are contained in a package having the sealant film as the inner surface, it is possible to use the contents without leaving the contents inside the package.

FIG. 1 is a cross-sectional explanatory view showing a specific example of a sealant film having a two-layer structure. FIG. 2 is a cross-sectional view showing a packaging material using a sealant film.

The sealant film according to the present invention has a heat-adhesive resin layer (hereinafter referred to as "fluorine-containing layer") containing a fluorine-based additive, and the fluorine-based additive bleeds out on the surface of the sealant film. It is a thing. The sealant film may have either a single layer structure or a multilayer structure, but in the case of the single layer structure, a single layer constituting the sealant film needs to be constituted by a fluorine-containing layer. Moreover, in the case of a multilayer structure, it is necessary for any one layer to be comprised by the fluorine-containing layer among several layers which comprise a sealant film. Further, in the case of a multilayer structure, generally, the fluorine-containing layer is disposed at a position to be the heat sealing surface when the sealant film is heat sealed.

  This sealant film can be laminated with any base film and used as a packaging material. For example, it is a lid of a container. It can also be used as a packaging bag material. In any case, it is desirable to dispose the fluorine-containing layer on the inner surface. Thus, the package manufactured by arranging the fluorine-containing layer on the inner surface can contain, for example, a liquid detergent as a content. Since the contained liquid detergent does not adhere to the fluorine-containing layer on the inner surface of the package, when the liquid detergent is poured out, it can be used up without remaining inside the package.

  The sealant film can be produced by melt extrusion film formation under specific conditions as described later. When the sealant film has a multilayer structure, a plurality of layers constituting the sealant film may be melt extruded.

  Next, the present invention will be described by taking a sealant film of a multilayer structure as an example. FIG. 1 of the drawings is a cross-sectional explanatory view showing a specific example of a two-layered sealant film, and FIG. 2 is a cross-sectional explanatory view showing a packaging material in which the sealant film is laminated on a base film.

  As can be seen from these figures, this sealant film 10 is composed of two layers, a fluorine-containing layer 1 and a thermoplastic resin layer 2 containing no fluorine additive (hereinafter referred to as "thermoplastic resin layer"). . And in this sealant film 10, the fluorine-type additive is bleeding out on the surface of the fluorine-containing layer 1, ie, the surface of the sealant film 10. Here, for convenience of explanation, a portion where the fluorine-based additive bleeds out in this way is hereinafter referred to as a "bleed-out film" and is illustrated by a symbol 1a.

  And in this invention, this bleed-out film | membrane 1a exhibits high liquid repellency, and prevents adhesion of a liquid detergent etc. For this purpose, it is desirable that the fluorine atoms derived from the fluorine-based additive bleed out to such an extent that they occupy 32 to 38 atomic% within the range of 10 nm from the surface of the sealant film 10. Even if a large amount of the fluorine-based additive is blended, the excess fluorine-based additive remains in the inside of the melt-extrusion film-forming machine, and the bleed-out amount of the sealant film 10 does not increase.

  The thickness of the sealant film 10 may be arbitrary, for example, about 20 to 200 μm. In the case of a two-layer structure as in this example, the thickness of the fluorine-containing layer 1 may be 3 μm to 20 μm, and the thickness of the thermoplastic resin layer 2 may be 20 to 180 μm.

  In addition, as heat bondable resin which comprises the fluorine-containing layer 1, well-known materials, such as polyolefin resin used as a heat seal film and polyolefin copolymer resin, are employable. Specifically, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, non-oriented polypropylene, ethylene vinyl acetate copolymer and the like can be mentioned.

  As a fluorine-type additive, the compound which has a C6 perfluoroalkyl group can be used conveniently. Such fluorine-based additives are commercially available from various companies. For example, "Megahook F-562" manufactured by DIC, "Megahook F-552", "Unidyne S-TG" manufactured by Daikin Industries, etc.

  Further, it is desirable that the thermoplastic resin constituting the thermoplastic resin layer 2 be excellent in compatibility with the heat adhesive resin. For example, it is a polyolefin resin or polyolefin copolymer resin such as low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, non-oriented polypropylene, ethylene vinyl acetate copolymer and the like.

  In the thermoplastic resin layer 2, an additive can be added in addition to the thermoplastic resin. For example, it is a slip agent. When this slip agent is blended, the amount of the fluorine-based additive blended in the fluorine-containing layer 1 can be reduced. Since the slip agent repels the fluorine-based additive, the fluorine-based additive bleeds to the opposite side, ie, the surface of the sealant film 10, so even if the blending amount of the fluorine-based additive is small, the surface of the sealant film 10 is The amount of fluorine-based additive that bleeds out can be sufficiently ensured. An amide slip agent can be suitably used as the slip agent. For example, erucic acid amide and the like. A masterbatch compounded with erucic acid amide is commercially available from Ube Maruzen Polyethylene Co., Ltd. under the trade name M425.

  Next, the base film 3 may be any film. For example, known materials can be used depending on the function required for the package, such as paper, synthetic resin, and the like. Specifically, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon-6 and nylon-66, polyvinyl chloride, cellophane, polyvinylidene chloride resin, polycarbonate resin, etc. It can be used suitably. Or the composite film which laminated | stacked these two or more films may be used. Moreover, aluminum foil and paper can also be used alone or in layers. Moreover, the thickness of the base film 3 is suitably selected within the range of 10 to 200 μm in consideration of processability. In addition, each layer used in known packaging materials may be laminated at any position. For example, a printing layer, a printing protective layer, an adhesive layer, a primer coat layer, an anchor coat layer etc. are mentioned.

  Moreover, the base film 3 can be laminated | stacked by methods, such as the dry laminating method, the extrusion laminating method, the wet laminating method, the heat laminating method.

  Next, a method of producing the sealant film 10 of the present invention will be described together with experimental data. The sealant film 10 of the present invention can be manufactured by two methods.

  First, the first manufacturing method is as follows. That is, first, 3 to 7% by mass of a fluorine-based additive is blended with the heat adhesive resin, and melt extrusion is performed to form a film. As in the illustrated example, in the case of the sealant film 10 having a two-layer structure, the thermoadhesive resin containing 3 to 7% by mass of the fluorine-based additive and the thermoplastic resin are melt co-extruded, A film having a two-layer structure may be formed. Then, the fluorinated film is bled out to the surface by storing the formed film at a temperature of 40 ° C. or more for 8 hours or more. As described above, the liquid repellent sealant film 10 thus obtained is bled out to such an extent that the fluorine-based additive occupies 32 to 38 atomic% within a range of 10 nm from the surface of the film 10.

  The experimental results related to this first manufacturing method will be described. This experiment consists of three kinds of experimental data. In the first experimental data, the amount of the fluorinated additive was varied to examine the amount of the fluorinated additive bled out on the surface (the amount of bleed out) and the contact angle of the liquid detergent. Further, the second experimental data is obtained by examining the storage time and the amount of bleed-out by changing the storage time after film formation. The third experimental data was obtained by examining the material and the amount of bleed-out by changing the material of the heat-adhesive resin.

  First, the first experiment was performed as follows.

That is, first, a linear low density polyethylene not containing a fluorine additive is used as the thermoplastic resin, and a linear low density polyethylene containing a fluorine additive is used as the heat adhesive resin, and these are melt co-extruded. The film was brought into contact with a cooling roll at 20 ° C. to form a film having a two-layer structure comprising the fluorine-containing layer 1 and the thermoplastic resin layer 2. Thereafter, a polyester film having a thickness of 12 μm was dry laminated on the thermoplastic resin layer 2 as a base film 3 to produce a packaging material.

  Then, it was stored at 40 ° C. for 12 hours, and the bleed out amount and the contact angle of the liquid detergent were measured.

  The amount of bleed-out was measured by X-ray photoelectron spectroscopy (XPS) to determine the proportion of fluorine atoms within a range of 10 nm from the surface. Among the materials constituting the packaging material, the fluorine-containing additive is the only one containing a fluorine atom, so the measured fluorine atoms are derived from the fluorine-based additive. For this reason, the value measured by this method can be used as an index indicating the bleed-out amount of the fluorine-based additive.

  Further, the contact angle of the liquid detergent was measured by dropping 5 μl of the liquid detergent and measuring its cross-sectional image. This result is shown in Table 1 about five types of packaging materials (samples 1-5) which changed the compounding quantity of the fluorine-type additive. In addition, "the addition amount of fluorine (mass%)" in the table means the compounding amount of the fluorine-based additive.

  From the first experimental data, the relationship between the amount of bleed out and the contact angle of the liquid detergent can be understood. That is, it can be understood that when the bleed-out amount exceeds 30 atomic%, the contact angle of the liquid detergent is 50 degrees or more, and the liquid detergent is less likely to adhere. Desirably, the amount of bleed-out is 32 atomic% or more, and at this time, the contact angle of the liquid detergent is 70 degrees or more, and the liquid detergent hardly adheres. And, in order to make the bleed out amount 30 atomic% or 32 atomic% or more in this way, the melt extrusion film formation was carried out by setting the compounding amount of the fluorine type additive to 3.0 mass% or more or 4.0 mass% or more After that, it may be stored at 0 ° C. for 12 hours.

  Next, the second experiment was performed as follows. As described above, the second experimental data is obtained by examining the storage time and the amount of bleed-out by changing the storage time after film formation.

  Also in this second experiment, as in the first experiment, a linear low density polyethylene in which a linear low density polyethylene not containing a fluorine additive is used as the thermoplastic resin and an fluorine additive is added is described above. As a heat adhesive resin, these were melt co-extruded, and brought into contact with a cooling roll at 20 ° C. to form a film of a two-layer structure composed of the fluorine-containing layer 1 and the thermoplastic resin layer 2. Thereafter, a polyester film having a thickness of 12 μm was dry laminated on the thermoplastic resin layer 2 as a base film 3 to produce a packaging material. And this packaging material was divided into 2 types, and one packaging material was preserve | saved at 40 degreeC. This is identical to sample 3 in the first experiment. In addition, the other packaging material was stored at normal temperature and used as sample 6. And the amount of bleed-out of these both packaging materials was measured. The amount of bleed-out was measured by XPS by the proportion of fluorine atoms within a range of 10 nm from the surface. In addition, the compounding quantity of a fluorine-type additive is 5.0 mass%. The results of these samples 3 and 6 are shown in Table 2.

  From this result, the relationship between the storage time after film formation and the amount of bleed-out can be understood. That is, the packaging material of sample 3 stored at 40 ° C. reaches a bleed-out amount of 34.0 atomic% in a storage time of 8 hours, and reaches 38.0 atomic% in 12 hours. From the first experiment described above, if the bleed-out amount is 32 atomic% or more, the contact angle of the liquid detergent becomes high, and the adhesion of the liquid detergent can be prevented. Thus, by setting the storage time to 8 hours or more, the liquid detergent It can be understood that the adhesion of On the other hand, for the packaging material of sample 6 stored at normal temperature, the amount of bleed-out did not change with the elapse of storage time, and was only 30.0 atomic% even after 24 hours. Therefore, it can be understood that it is important to store at a high temperature of about 40 ° C. in order to bleed out the fluorine-based additive.

  Next, the third experiment was performed as follows. As described above, the third experimental data is obtained by examining the material and the amount of bleed-out by changing the material of the heat-adhesive resin constituting the fluorine-containing layer 1.

  Also in this experiment, as in the first experiment, a linear low density polyethylene not containing a fluorine additive is used as the thermoplastic resin, and a polyolefin resin containing a fluorine additive is used as the heat adhesive resin. The melt co-extrusion was brought into contact with a cooling roll at 20 ° C. to form a film having a two-layer structure comprising the fluorine-containing layer 1 and the thermoplastic resin layer 2. Thereafter, a polyester film having a thickness of 12 μm was dry laminated on the thermoplastic resin layer 2 as a base film 3 to produce a packaging material. And it stored at 40 degreeC and 12 hours, and measured the amount of bleed-out. The amount of bleed-out was measured by XPS by the proportion of fluorine atoms within a range of 10 nm from the surface. In addition, three types of polyolefin resins, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and polypropylene (PP), were used as the heat adhesive resin. Moreover, the compounding quantity of a fluorine-type additive is 5.0 mass%, and the packaging material which used LLDPE is the same as the sample 3 in 1st experiment. The packaging material using LDPE is Sample 7, the sample using PP is Sample 8, and the results of Samples 3 to 8 are shown in Table 3.

  From this result, it can be understood that the fluorine-based additive bleeds out regardless of the type of heat-adhesive resin that constitutes the fluorine-containing layer 1. However, it is the linear low density polyethylene (sample 3) that the amount of bleed-out is the highest, and it can be seen that the linear low density polyethylene is excellent as the heat adhesive resin.

  Next, the second production method of the sealant film of the present invention is as follows. That is, it is a method of melt-extruding a thermoadhesive resin containing 3 to 7% by mass of a fluorine-based additive to form a film, and bringing this molten film into contact with a cooling roll at a temperature of 50 ° C. or higher. As in the illustrated example, in the case of the sealant film 10 having a two-layer structure, the heat adhesive resin containing 3 to 7% by mass of the fluorine-based additive and the thermoplastic resin are melt coextruded, 50 ° C. The film having a two-layer structure may be formed in contact with a cooling roll at the above temperature. Also by this method, it is possible to bleed out the fluorine-based additive on the surface. And the film 10 manufactured by this method also bleeds out to such an extent that the said fluorochemical additive accounts for 32 to 38 atomic% within the range of 10 nm from the surface.

  In addition, the experimental result investigated about the relationship between the temperature of a cooling roll and the amount of bleed-out is as follows.

In this experiment, a linear low density polyethylene not containing a fluorine-based additive and a linear low density polyethylene containing a fluorine-based additive are melt co-extruded and brought into contact with a cooling roll to form a fluorine-containing layer 1 A film having a two-layer structure consisting of the thermoplastic resin layer 2 was formed. Thereafter, a polyester film having a thickness of 12 μm was dry laminated on the thermoplastic resin layer 2 as a base film 3 to produce a packaging material. And the amount of bleed-out was measured. The amount of bleed-out was measured by XPS by the proportion of the fluorine-based additive within a range of 10 nm from the surface. The results are shown in Table 4 with the packaging material manufactured at a cooling roll temperature of 60.0 ° C. as sample 9 and the packaging material manufactured at 20.0 ° C. as sample 10.

  From this result, when the temperature of the cooling roll is 50 ° C. or higher, the fluorine-based additive bleeds out sufficiently without being stored at a high temperature of 40 ° C. or higher, and the bleed-out amount becomes 32 atomic% or more, It can be understood that the adhesion of the liquid detergent can be prevented.

  Next, as described above, when the slip agent is blended in the thermoplastic resin layer 2, the blending amount of the fluorine-based additive can be reduced. This point was also confirmed by experiments.

  In this experiment, two types of resins were prepared as the thermoplastic resin. The first thermoplastic resin is a linear low density polyethylene which does not contain a slip agent. Of course, this linear low density polyethylene does not contain a fluorine additive. The second thermoplastic resin is a linear low density polyethylene blended with 2% by mass of a slip agent. The linear low density polyethylene also contains no fluorine additive.

  Then, as in the first experiment, these two types of resins are used as the thermoplastic resin, and linear low density polyethylene containing a fluorine-based additive is used as the thermal adhesive resin, and these thermoplastic resins are thermally bonded to the thermoplastic resin. And a thermoplastic resin were brought into contact with a cooling roll at 20.degree. C. to form a film having a two-layer structure comprising a fluorine-containing layer 1 and a thermoplastic resin layer 2. Thereafter, a polyester film having a thickness of 12 μm was dry laminated on the thermoplastic resin layer 2 as a base film 3 to produce a packaging material. And the amount of bleed-out of these both packaging materials was measured. The amount of bleed-out was measured by XPS by the proportion of the fluorine-based additive within a range of 10 nm from the surface. In addition, the compounding quantity of a fluorine-type additive is 2.0 mass%.

  The packaging material using the linear low density polyethylene which does not mix | blend a slip agent is made into the sample 11, and the packaging material which uses linear low density polyethylene which mix | blended 2 mass% slip agents is made into the sample 12, This result is Table 5 Shown in.

  As can be seen from this result, when the thermoplastic resin layer 2 contains a slip agent (Sample 12), the sealant is obtained even if the amount of the fluorine-based additive blended in the fluorine-containing layer 1 is only 2% by mass. It can be understood that the adhesion of the liquid detergent can be prevented by setting the amount of the fluorine-based additive which bleeds out to the surface of the film 10 to 32 atomic% or more.

10: Repellent sealant film 1: Fluorine-containing layer 1a: Bleed-out film 2: Thermoplastic resin layer 20: Packaging material

Claims (10)

It is a sealant film of single layer structure or multilayer structure,
A liquid repellent sealant film having a heat-adhesive resin layer containing a fluorine-based additive and having a fluorine-based additive bleeding out on the surface of the sealant film in the layer structure. . A multi-layered sealant film,
The layer structure includes a heat-adhesive resin layer containing a fluorine-based additive and a thermoplastic resin layer not containing a fluorine-based additive, and the fluorine-based additive bleeds on the surface of the sealant film A liquid repellent sealant film characterized by being out.   The liquid repellent sealant film according to claim 2, wherein a slip agent is blended in the thermoplastic resin layer which does not contain a fluorine-based additive.   The liquid repellent sealant film according to any one of claims 1 to 3, wherein the fluorine-based additive has a C 6 perfluoroalkyl group.   The liquid repellent sealant film according to any one of claims 1 to 4, wherein a fluorine atom occupies 32 to 38 atomic% within a range of 10 nm from the surface of the sealant film.   The heat adhesive resin containing a fluorine-based additive is formed by melt extrusion, and then stored at a temperature of 40 ° C. or more for 12 hours or more to bleed out the fluorine-based additive on the surface. Method for producing a liquid repellent sealant film.   The heat adhesive resin containing a fluorine-based additive is melt extruded and formed into a film, and then brought into contact with a cooling roll at a temperature of 50 ° C. or more to bleed out the fluorine-based additive on the surface. Method for producing a liquid repellent sealant film.   The method for producing a liquid repellent sealant film according to claim 6 or 7, wherein 3 to 7% by mass of a fluorine-based additive is blended to the heat adhesive resin.   By melt coextrusion film formation of a thermoadhesive resin containing 2 to 6% by mass of a fluorine-based additive and a thermoplastic resin containing a slip agent, and then storing the film at a temperature of 40 ° C. or more for 8 hours or more A method for producing a liquid repellent sealant film having a multilayer structure, wherein the fluorine-based additive is bled out to the surface.   The thermoadhesive resin containing 2 to 6% by mass of a fluorine-based additive and the thermoplastic resin containing a slip agent are melt coextrusion film-formed and brought into contact with a cooling roll having a temperature of 50 ° C. or more. A method for producing a liquid repellent sealant film having a multilayer structure, which comprises bleeding out a fluorine-based additive on the surface.

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