JP2018069598A - Sealant film, multilayer film using the same and packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant film which is excellent in low adsorptivity and has a MAX strength of 23 N/15 mm or more.SOLUTION: There is provided a sealant film which comprises a polyolefin layer containing a polyolefin and a polycycloolefin layer containing a polycycloolefin as a main component which serves as the outermost layer. The polycycloolefin comprises two or more structural units selected from a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound and a structural unit (C) derived from a norbornene compound, the polycycloolefin has a glass transition temperature of 80°C or less, the polycycloolefin layer has a thickness (T2) of 5 μm or more and 10 μm or less and a ratio (a) of the thickness (T1) of the polyolefin layer to the thickness (T2) of the polycycloolefin layer is 3 or more and 9 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealant film, a laminated film using the same, and a packaging bag.

  Conventionally, as a packaging container for storing contents such as foods, beverages, and pharmaceuticals, for example, a packaging bag composed of a laminated film in which a base material sheet made of a resin film or paper and a sealant film are laminated is widely used. Has been. In addition, in order to suppress deterioration of the contents due to oxygen, reduction due to external diffusion of contents, etc., the gas barrier film is further laminated, or the gas barrier property is imparted to the base sheet, thereby improving the permeability of the laminated film. It is decreasing.

  On the other hand, the contents (especially medicinal ingredients, fragrance ingredients, etc.) are adsorbed or absorbed by the sealant film (especially polyolefin film, etc.) in contact with the contents, which reduces the amount of the contents or degrades the quality. (For example, refer to JP, 2015-137130, A (patent documents 1)).

  In JP 2010-6985 (Patent Document 2), a structural unit derived from a dicyclopentadiene compound, a structural unit derived from a tetracyclododecene compound, and a structural unit derived from a norbornene compound are included at a specific ratio. The hydrogenated product of the ring-opening copolymer contains excellent solution stability during production, and the molding material containing this hydrogenated product as a resin component has high transparency, high moisture resistance, and appropriate heat resistance. Is disclosed.

JP2015-137130A JP 2010-6985 A

  Medicinal components such as EVOH (ethylene / vinyl alcohol copolymer resin), PET (polyethylene terephthalate) resin, polyacrylonitrile (PAN), etc., as materials for the sealant film to suppress the adsorption or absorption of the contents to the sealant film The use of a low-adsorbing material that is difficult to adsorb or absorb contents such as aroma components has been studied. However, these materials have a problem of insufficient seal strength.

  Therefore, the present inventors examined a sealant film excellent in low adsorptivity and seal strength. As a result, it has been found that it is effective to use a laminated film of a polyolefin layer and a polycycloolefin layer containing a specific polycycloolefin as a main component as a sealant film. The applicant of the present application has already filed a patent application (Japanese Patent Application No. 2006-142373) for such a sealant film.

  As a result of further investigation, it has been found that this sealant film may not satisfy the MAX strength (23 N / 15 mm or more) required when used as a packaging bag.

  This invention is made | formed in view of said subject, and it aims at providing the sealant film which is excellent in low adsorptivity and has MAX intensity | strength of 23 N / 15mm or more.

[1]
A polyolefin layer comprising a polyolefin;
A sealant film comprising a polycycloolefin layer containing polycycloolefin as a main component as an outermost layer,
The polycycloolefin is selected from a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound, and a structural unit (C) derived from a norbornene compound. Including more than one structural unit,
The glass transition temperature of the polycycloolefin is 80 ° C. or less,
The thickness (T2) of the polycycloolefin layer is 5 μm or more and 10 μm or less,
The sealant film, wherein the ratio (a) of the thickness (T1) of the polyolefin layer to the thickness (T2) of the polycycloolefin layer is 3 or more and 9 or less.

[2]
The polycycloolefin includes a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound, and a structural unit (C) derived from a norbornene compound [1 ] The sealant film as described in.

[3]
The sealant film according to [1] or [2], wherein the polycycloolefin has a glass transition temperature of 40 ° C or higher.

[4]
The dicyclopentadiene compound is tricyclo [5.2.1.0 ^2,6 ] deca-3,8-diene (synonymous with dicyclopentadiene) or a derivative thereof, and the tetracyclododecene compound is tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene or a derivative thereof, and the norbornene-based compound is bicyclo [2.2.1] hept-2-ene or a derivative thereof, according to any one of [1] to [3] The sealant film as described.

[5]
The polycycloolefin is a ring-opening metathesis polymer of two or more compounds selected from the dicyclopentadiene compound, the tetracyclododecene compound and the norbornene compound, and has a carbon-carbon double bond. The sealant film according to any one of [1] to [4], which is hydrogenated.

[6]
A base sheet;
A laminated film obtained by laminating the sealant film according to any one of [1] to [5].

[7]
Furthermore, the laminated film according to [6], wherein a gas barrier film is laminated between the base sheet and the sealant film.

[8]
The laminated film according to [6] or [7], wherein the thickness is 100 μm or less.

[9]
A packaging bag formed by sealing the laminated film according to any one of [6] to [8] so that the sealant films are fused together.

  ADVANTAGE OF THE INVENTION According to this invention, the sealant film which is excellent in low adsorptivity and has the MAX intensity | strength of 23 N / 15mm or more can be provided.

1 is a schematic cross-sectional view showing a sealant film of Embodiment 1. FIG. It is a schematic sectional drawing which shows the laminated | multilayer film of Embodiment 2. It is a schematic sectional drawing which shows the laminated film of Embodiment 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals represent the same or corresponding parts.

<Sealant film>
[Embodiment 1]
With reference to FIG. 1, the sealant film 1 of this embodiment is a sealant film which consists of two layers, a polyolefin layer 11 (base sheet side) and a polycycloolefin layer 12 (seal side).

(Polyolefin layer: base sheet side)
The polyolefin layer 11 contains polyolefin. In addition, content of polyolefin with respect to the whole quantity of the polyolefin layer 11 becomes like this. Preferably it is 50 mass% or more, More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more. The polyolefin layer 11 may contain a material other than polyolefin.

  As the polyolefin, polyethylene can be suitably used. As polyethylene, for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and the like can be suitably used.

(Polycycloolefin layer: seal side)
The polycycloolefin layer 12 contains polycycloolefin as a main component. Note that “include as a main component” means, for example, that the content of polycycloolefin is more than 50% by mass with respect to the total amount of the polycycloolefin layer 12, and the content of polyolefin is preferably 80% by mass. As mentioned above, More preferably, it is 90 mass% or more. Moreover, you may mix | blend other polymeric materials, various additives, etc. which are disclosed by patent document 2. FIG.

  The polycycloolefin includes structural units derived from two or more compounds (cycloolefin monomers) selected from dicyclopentadiene compounds, tetracyclododecene compounds, and norbornene compounds. That is, the polycycloolefin is selected from a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound, and a structural unit (C) derived from a norbornene compound. Contains two or more structural units.

  Preferably, the polycycloolefin includes a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound, and a structural unit (C) derived from a norbornene compound.

  When the polycycloolefin contains the structural units (A), (B) and (C), the ratio of the structural unit (A) derived from the dicyclopentadiene compound is preferably 5 to 80 mol%. The ratio of the structural unit (B) derived from the tetracyclododecene compound is preferably 10 to 90 mol%. The ratio of the structural unit (C) derived from the norbornene compound is preferably 5 to 50 mol%. In addition, these ratios are ratios when the sum of the structural units (A), (B), and (C) is 100 mol%. Even in this case, the polycycloolefin may contain a structural unit other than the structural units (A), (B) and (C) as long as the effects of the present invention are not impaired.

Examples of the dicyclopentadiene compound include dicyclopentadiene (tricyclo [5.2.1.0 ^2,6 ] deca-3,8-diene) and derivatives thereof. Examples of the dicyclopentadiene derivative include 2-methyldicyclopentadiene, 2,3-dimethyldicyclopentadiene, and 2,3-dihydroxydicyclopentadiene.

  In addition, examples of the structural unit (A) derived from a dicyclopentadiene compound include a structural unit derived from dicyclopentadiene.

Examples of the tetracyclododecene compound include tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene and its derivatives. Tetracyclo [4.4.0.1 ^2,5 . As a derivative of 1 ^7,10 ] -3-dodecene, for example, 8-methyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8,9-dimethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethyl-9-methyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-ethylidene-9-methyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, 8-methyl-8-carboxymethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene and the like.

Moreover, as a structural unit (B) derived from a tetracyclododecene compound, for example, tetracyclo [4.4.0.1 ^2,5 . And a structural unit derived from 1 ^7,10 ] -3-dodecene.

  Examples of the norbornene-based compound include bicyclo [2.2.1] hept-2-ene (common name: norbornene) and derivatives thereof. Examples of the derivatives of bicyclo [2.2.1] hept-2-ene include 5-methyl-bicyclo [2.2.1] hept-2-ene and 5,5-dimethyl-bicyclo [2.2. 1] Hept-2-ene, 5-ethyl-bicyclo [2.2.1] hept-2-ene, 5-ethylidene-bicyclo [2.2.1] hept-2-ene, 5-vinyl-bicyclo [ 2.2.1] hept-2-ene, 5-propenylbicyclo [2.2.1] hept-2-ene, 5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, 5- And cyanobicyclo [2.2.1] hept-2-ene, 5-methyl-5methoxycarbonyl-bicyclo [2.2.1] hept-2-ene, and the like.

  In addition, examples of the structural unit (C) derived from the norbornene compound include a structural unit derived from bicyclo [2.2.1] hept-2-ene.

  The polycycloolefin is preferably obtained by ring-opening metathesis copolymerization of the above cycloolefin monomer and then hydrogenating the C—C double bond. Such a polycycloolefin can be produced based on Patent Document 2.

  The glass transition temperature (Tg) of the polycycloolefin is 80 ° C. or lower, preferably 75 ° C. or lower. In this case, it is possible to obtain a sealant film having appropriate seal strength and low-temperature sealability in addition to non-adsorbability. Tg can be measured based on JIS K7121.

  In addition, since there exists a possibility that a sealant film may fuse | melt when Tg of polycycloolefin becomes the same as room temperature, Tg of polycycloolefin becomes like this. Preferably it is 40 degreeC or more, More preferably, it is 50 degreeC or more.

  The sealant film 1 can be produced, for example, as a film having a two-layer structure by coextruding the above-described polyolefin layer (film-shaped semi-molded product) and polycycloolefin layer (film-shaped semi-molded product). . The thickness of the sealant film 1 is preferably 100 μm or less. The thickness of the sealant film 1 is preferably 10 μm or more.

  The sealant film 1 of the present embodiment includes a layer composed of a polycycloolefin containing a structural unit derived from two or more kinds of specific cycloolefin monomers as described above, so that the contents (medicinal components, aroma components) Or the like) and is sufficiently non-adsorptive with sufficient sealing strength.

  In the present embodiment, the thickness (T2) of the polycycloolefin layer 12 is 5 μm or more and 10 μm or less. The ratio (a: T1 / T2) of the thickness (T1) of the polyolefin layer 11 to the thickness (T2) of the polycycloolefin layer 12 is 3 or more and 9 or less.

  The thickness of each layer (the polyolefin layer 11 and the polycycloolefin layer 12) can be measured with a microscope scale by observing the cut surface with a microscope after cutting the sealant film with a cutter or the like.

  By designing the thickness (T1) of the polyolefin layer 11 and the thickness (T2) of the polycycloolefin layer 12 in such a range, the sealant is excellent in low adsorptivity and has a MAX strength of 23 N / 15 mm or more. Film 1 can be obtained.

  Here, the MAX strength is not the initial seal strength or the like but the seal strength when the seal strength curve reaches the maximum and is stable. The retort standard (JIS Z0238) stipulates that the MAX strength is 23 N / 15 mm or more. The seal strength (MAX strength) can be measured according to JIS Z0238.

  In addition, the polyolefin layer 11 which comprises the sealant film 1 has a role which makes a film flexible. If the polycycloolefin layer 12 comprising a ring-opening metathesis polymer of two or more compounds selected from dicyclopentadiene compounds, tetracyclododecene compounds and norbornene compounds is a single layer, the film is hard and corona treatment Film formation is difficult, and it is very difficult to manufacture as a packaging bag. Therefore, by using the polyolefin layer 11 adjacent to the polycycloolefin layer 12, it has become possible to manufacture as a packaging bag by improving processability and film forming suitability.

  Moreover, the sealant film of the present embodiment also has a low temperature sealing property. Specifically, for example, the rising temperature of the seal strength of the sealant film (an index of the lowest temperature that can be sealed) is preferably 120 ° C. or less with regard to the low temperature sealability. The rising temperature of the seal strength is measured according to JIS Z0238, taking the temperature as a level.

Moreover, the sealant film of the present embodiment is also excellent in moisture resistance. Regarding moisture resistance, specifically, the water vapor permeability of a laminated film having a thickness of 50 μm or less formed by laminating a sealant film and a non-barrier substrate sheet is 5.0 g / (m ² · 24 h) or less. It is preferable. The moisture permeability (water vapor permeability) is measured under the conditions of 40 ° C. and 90% RH based on JIS K7129A.

<Laminated film>
[Embodiment 2]
With reference to FIG. 2, the laminated film 2 (packaging material) of the present embodiment is a laminated film in which the sealant film 1, the adhesive layer 41, and the base sheet 31 of the first embodiment are laminated in this order. is there. The thickness of the laminated film is preferably 100 μm or less.

  The base sheet 31 is not particularly limited as long as it has mechanical strength and dimensional stability, but a plastic film, paper, nonwoven fabric, and the like can be used. Examples of the constituent material of the plastic film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polypropylene, polyamides such as polystyrene and 6-nylon, polycarbonate, polyacrylonitrile, and polyimide. The plastic film is preferably a biaxially stretched film. In the present embodiment, the base sheet 31 is a PET film.

  Although it does not specifically limit as an adhesive agent which comprises the contact bonding layer 41, The adhesive agent for dry lamination can be used suitably. Adhesives for dry lamination include two-component curable urethane adhesives, polyester urethane adhesives, polyether urethane adhesives, acrylic adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, etc. Is mentioned. In addition, as a method of bonding the sealant film 1 and the gas barrier film 6 using such an adhesive, a dry laminating method may be mentioned.

  Among the above adhesives, a two-component curable adhesive that does not easily lower the adhesive force due to excellent adhesive force and chemical components of the contents can be suitably used. The two-component curable adhesive is composed of a main agent and a curing agent, and examples thereof include a two-component curable adhesive composed of a polyester polyol and a polyfunctional polyisocyanate.

  In place of the above adhesive layer, an anchor coat agent (two-component curable urethane adhesive, polyallylamine, etc.) may be used.

  By providing the sealant film of Embodiment 1, the laminated film of this embodiment is a non-adsorptive film in which the adsorption or absorption of the contents (medicinal components, aroma components, etc.) is suppressed as in Embodiment 1. In addition, it has sufficient sealing strength and the like, and the physical property change due to γ-ray sterilization is suppressed.

[Embodiment 3]
Referring to FIG. 3, in the laminated film of the present embodiment, a gas barrier film 6 is laminated in the middle in order to suppress deterioration of the contents due to oxygen gas, reduction due to external diffusion of the contents, and the like. Except this point, the second embodiment is the same as the second embodiment. Note that an adhesive layer 42 for adhering the gas barrier film 6 such as an aluminum foil to the sealant film 1 is provided.

  Examples of the gas barrier film 6 include an aluminum foil. In addition, a film having an aluminum vapor deposition film, a film having an inorganic oxide vapor deposition film, or the like can be used. Specifically, for example, a film obtained by forming an aluminum vapor deposition film or an inorganic oxide vapor deposition film on a stretched film such as a polyester film, a polypropylene film, or a nylon film can be used. As the gas barrier film 6, an ethylene / vinyl alcohol copolymer film can also be used.

  As the adhesive constituting the adhesive layer 42, the same material as the adhesive layer 41 can be used. The adhesive constituting the adhesive layer 41 and the adhesive constituting the adhesive layer 42 may be the same component or different components.

<Packaging bag>
Using the laminated film formed as described above, a bag is formed into a desired shape to form a packaging bag. For example, if a pillow type packaging bag, a caseette type packaging bag, a self-supporting type packaging bag, etc. (see Patent Document 1) are prepared according to the purpose (packaging bag design, internal capacity, ease of use, etc.) Good. In such a packaging bag, at least two of the above laminated films are sealed at least partially so that the sealant films are fused together.

  Examples of the contents include pharmaceuticals, quasi drugs, foods, and beverages. The packaging bag of the present embodiment is particularly about contents containing medicinal components, aromatic components, etc. (components that are easily adsorbed or absorbed in the packaging bag, or components that are problematically adsorbed or absorbed in the packaging bag), It can be preferably used. Specifically, the packaging bag of the present embodiment is preferably used to store, for example, a transdermal absorbent or mouthwash containing medicinal ingredients, cosmetics containing aroma components such as fragrance, coffee, and the like. Can do.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

(Examples 1-5, Comparative Examples 1-5)
Similarly to Embodiment 2, the base material sheet 31 and the sealant film 1 of Embodiment 1 are laminated via a two-component curable polyester and polyurethane adhesive, and Examples 1 to 5 and Comparative Examples 1 to 5 are stacked. A laminated film was produced.

  The base sheet 31 is made of polyethylene terephthalate (PET). The thickness of the base material sheet 31 is 12 μm.

  The sealant film 1 includes a polyolefin layer 11 and a polycycloolefin layer 12. The polyolefin (PO) layer is made of linear low density polyethylene (LLDPE).

The polycycloolefin (PCO) layer is composed of the following polycycloolefin A.
Polycycloolefin A:
Tricyclo [5.2.1.0 ^2,6 ] deca-3,8-diene,
Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, and
It is a terpolymer of three types of cycloolefin monomers consisting of bicyclo [2.2.1] hept-2-ene, and these cycloolefin monomers are subjected to ring-opening metathesis copolymerization, and then a C—C double bond It can be obtained by hydrogenating.

  The thickness of the polyolefin (PO) layer 11 and the thickness of the polycycloolefin (PCO) layer 12 are as shown in Table 1.

(Examples 6-12, Comparative Examples 6-12)
Similarly to the third embodiment, the base material sheet 31, the gas barrier film 6, and the sealant film 1 of the first embodiment are laminated via a two-component curable polyester and a polyurethane adhesive. Examples 6 to 12 and comparison The laminated films of Examples 6 to 12 were produced.

  The base sheet 31 is made of polyethylene terephthalate (PET). The gas barrier film 6 is an aluminum foil. The thickness of the base material sheet 31 is 12 μm, and the thickness of the gas barrier film 6 is 7 μm.

  The sealant film 1 includes a polyolefin layer 11 and a polycycloolefin layer 12. The polyolefin (PO) layer is made of linear low density polyethylene (LLDPE).

The polycycloolefin (PCO) layer is composed of the above polycycloolefin A.
The thickness of the polyolefin (PO) layer 11 and the thickness of the polycycloolefin (PCO) layer 12 are as shown in Table 1.

<Evaluation test 1>
About said Examples 1-12 and Comparative Examples 1-12, "seal strength" (MAX strength) was evaluated.

  Specifically, each laminated film of Examples 1-12 and Comparative Examples 1-12 was sealed with the sealant film inside. The sealing conditions were a sealing temperature of 170 ° C., a sealing pressure of 0.2 MPa, and a sealing time of 1.0 second. The peel strength (seal strength) of the laminated films cut into strips was measured based on JIS Z0238 for the peel strength (N / 15 mm) of the two laminated films sealed. In addition, the seal strength was measured by using the maximum value at the place where the seal strength curve was stable as the MAX strength.

<Evaluation Test 2>
About said Examples 6-12 and Comparative Examples 6-12, evaluation of low adsorptivity was performed.

  Specifically, each laminated film of Examples 6 to 12 and Comparative Examples 6 to 12 is cut into a predetermined shape, and the two laminated films are stacked so that the sealant films are in contact with each other. The three-sided bag-making type packaging bag was created by sealing the predetermined region. At this time, the upper end (top seal portion) of the packaging bag is not yet sealed to fill the contents.

  Next, l-menthol (0, 1, 3 or 6M aqueous solution) is filled from the upper end of the packaging bag in a nitrogen atmosphere, and the upper end (top seal part) of the packaging bag is sealed to seal the contents. did. This component is generally a component that is easily adsorbed by the sealant film.

  The packaging bag containing the contents as described above was stored for a month in a thermostat maintained at 40 ° C. After storage, the packaging bag was opened, each component was extracted from the sealant film only by ethanol extraction, and the amount of each extracted component was measured using high performance liquid chromatography. Based on the measured value, the ratio of the residual amount after each storage period to the initial amount was calculated as the residual rate (%).

  In addition, since Examples 6-12 and Comparative Examples 6-12 are provided with a gas barrier film (aluminum (AL) foil) and can prevent the absorption from the contents to the base material, the adsorptivity to the sealant film is evaluated. Is possible.

  The results of the above evaluation tests 1 and 2 are shown in Table 1. In the column of “peeling surface”, the state of the surface (peeling surface) where peeling occurred in evaluation test 1 is described.

  In addition, about the polycycloolefin layer used for Examples 1-12 and Comparative Examples 1-12, the glass transition temperature (Tg) measured based on JISK7121 using the differential scanning calorimetry analyzer was 70 degreeC. It was.

  As shown in Table 1, the thickness (T2) of the polycycloolefin layer is 5 μm or more and 10 μm or less, and the ratio (a) of the thickness (T1) of the polyolefin layer to the thickness (T2) of the polycycloolefin layer is In Examples 1-12 which are 3-9, it turns out that the MAX intensity | strength of 23 N / 15mm or more is provided.

  On the other hand, in Comparative Examples 1 to 8, 11 and 12 in which T2 and a (T1 / T2) are out of the above range, the MAX intensity is less than 23 N / 15 mm.

  As described in the section of the peeling surface in Table 1, in Examples 1 to 12, peeling is started from a low strength PCO layer by reducing the thickness of the PCO layer to some extent. This is considered to be because the MAX strength is increased because of the transition to the high-strength PO layer.

  On the other hand, when the thickness of the PCO layer is increased as in Comparative Examples 4, 5, 11, and 12, peeling starts from the PCO layer, and the peeled surface is in the low-strength PCO layer, so the MAX strength is high. It is thought not to be. Moreover, even if the PCO layer is thin as in Comparative Examples 1 to 3 and 6 to 8, if the PO layer is also thin (when the ratio a is small), peeling starts from the PCO layer, It is considered that the MAX strength does not increase even though the PO layer moves to a high-strength PO layer because the PO layer does not extend sufficiently.

  Moreover, it turns out that the sealant film of this invention is excellent in the low adsorptivity from the evaluation result of the low adsorptivity (residual rate) about Examples 6-12. This is because a sealant film is a copolymer of two or more kinds of specific cycloolefin polymers, and a polycycloolefin layer containing a polycycloolefin having a glass transition temperature (Tg) of 80 ° C. or less and a polyolefin layer. This is because it is a laminate.

  In Comparative Examples 9 and 10 in which T2 is in the above range and a (T1 / T2) exceeds 9, the MAX strength is 23 N / 15 mm or more, but the concentration of the content is particularly high. It can be seen that the low adsorptivity deteriorates. This is probably because when the PO layer is thicker, the amount of adsorption to the PO layer increases and the low adsorptivity deteriorates.

  From the above results, the thickness (T2) of the polycycloolefin layer is 5 μm or more and 10 μm or less, and the ratio (a) of the thickness (T1) of the polyolefin layer to the thickness (T2) of the polycycloolefin layer is 3 or more. When it is 9 or less, it is considered that the sealant film 1 having excellent low adsorptivity and having a MAX strength of 23 N / 15 mm or more can be obtained.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The sealant film of the present invention can be used as the innermost layer of a laminated film constituting a packaging bag.

  DESCRIPTION OF SYMBOLS 1 Sealant film, 11 Polyolefin layer, 12 Polycycloolefin layer, 2 Laminate film, 31 Base material sheet, 41, 42 Adhesive layer, 6 Gas barrier film.

Claims (9)

A polyolefin layer comprising a polyolefin;
A sealant film comprising a polycycloolefin layer containing polycycloolefin as a main component as an outermost layer,
The polycycloolefin is selected from a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound, and a structural unit (C) derived from a norbornene compound. Including more than one structural unit,
The glass transition temperature of the polycycloolefin is 80 ° C. or less,
The thickness (T2) of the polycycloolefin layer is 5 μm or more and 10 μm or less,
The sealant film, wherein the ratio (a) of the thickness (T1) of the polyolefin layer to the thickness (T2) of the polycycloolefin layer is 3 or more and 9 or less.   The polycycloolefin includes a structural unit (A) derived from a dicyclopentadiene compound, a structural unit (B) derived from a tetracyclododecene compound, and a structural unit (C) derived from a norbornene compound. The sealant film according to 1.   The sealant film according to claim 1 or 2, wherein the polycycloolefin has a glass transition temperature of 40 ° C or higher. The dicyclopentadiene compound is tricyclo [5.2.1.0 ^2,6 ] deca-3,8-diene or a derivative thereof, and the tetracyclododecene compound is tetracyclo [4.4.0.1. ^2,5 . 1, ¹⁰ ] -3-dodecene or a derivative thereof, wherein the norbornene-based compound is bicyclo [2.2.1] hept-2-ene or a derivative thereof. The sealant film as described.   The polycycloolefin is a ring-opening metathesis polymer of two or more compounds selected from the dicyclopentadiene compound, the tetracyclododecene compound and the norbornene compound, and has a carbon-carbon double bond. The sealant film according to any one of claims 1 to 4, which is hydrogenated. A base sheet;
The laminated film formed by laminating | stacking the sealant film of any one of Claims 1-5.   Furthermore, the laminated | multilayer film of Claim 6 formed by laminating | stacking a gas barrier film between the said base material sheet and the said sealant film.   The laminated film according to claim 6 or 7, wherein the thickness is 100 µm or less.   A packaging bag formed by sealing the laminated film according to any one of claims 6 to 8 so that the sealant films are fused.

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