JP2018114755A - Barrier property sealant, multilayer film, and packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer film suppressing swelling of an adhesive layer even when packaging an object to be packaged containing a solvent having high permeability, suppressing poor appearance caused by delamination, and capable of forming a packaging bag decreased in a thickness, and a barrier property sealant capable of forming a multilayer film, a packaging bag.SOLUTION: The multilayer film has at least an adhesive layer 2, a film layer 3, and a thermal adhesiveness polyolefin resin layer 4 on a base material film 1 in this order where the film layer 3 is a barrier property sealant containing a polyvinyl alcohol-based copolymer having an amino group on a side chain, and further has a barrier layer between the base material film 1 and the adhesive layer 2 where the barrier layer is composed of a resin film one side of which contains at least one kind selected from the group consisting of aluminum, aluminum oxide, silica, m-xylylene diamine, and ethylene vinyl alcohol copolymer, or the barrier layer is a metal foil.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a barrier sealant, a multilayer film, and a packaging bag.

  Conventionally, a can, a plastic bottle, etc. are used as containers, such as a liquid. In recent years, packaging containers that can be reduced in volume by being folded after use have been used as containers for such liquids.

  Some contents such as liquid may contain volatile or highly permeable solvents, etc., and these contents permeate the highly permeable polyolefin resin, There is a problem in that delamination phenomenon (delamination) occurs, causing poor appearance (lamination floating). In particular, when a urethane adhesive that is widely used as an adhesive is used, the content that has passed through the polyolefin resin layer swells and lowers the molecular weight of the polyol component that is the main component of the urethane adhesive. The above-mentioned problem is remarkable.

  As a laminate for forming a packaging bag for solving such a problem, a multilayer laminate comprising at least a layer made of ethylene vinyl copolymer resin, a layer made of nylon, and a layer made of polyethylene on a sealant layer There has been proposed a laminate in which the lowermost layer of the multilayer laminate corresponding to the sealant layer side is the polyethylene (see Patent Document 1). Further, an adhesive layer, an olefin-based resin layer extruded and formed in a molten state, and a sealant layer are provided in this order on the substrate, and the adhesive layer contains a polyol and an isocyanate compound in a weight ratio. A laminated body containing 0: 100 to 20:80 is proposed (see Patent Document 2).

JP2015-128865A Japanese Patent No. 4894177

  However, the laminate described in Patent Document 1 uses an ethylene vinyl copolymer resin layer as a layer for suppressing permeation of volatile substances such as fragrances and medicinal components, and further penetrates like a solvent. The barrier property against a highly functional substance is not sufficient. For this reason, when providing layers, such as a base material layer, via an adhesive layer on an ethylene vinyl copolymer resin layer, there exists a problem that an adhesive layer swells and produces delamination and causes the appearance defect. Further, since the adhesiveness between the ethylene vinyl copolymer resin layer and the polyethylene layer is low, it is necessary to provide a layer for improving the adhesiveness such as a nylon layer between them. For this reason, it becomes necessary to provide a sealant layer in order to reduce the thickness of the polyethylene layer and improve the sealing strength, and there is a problem that the layer thickness is increased, and it is necessary to perform a process of laminating the sealant layer, which is costly. There is a problem of increasing.

  Moreover, although the laminated body described in the patent document 2 raises the crosslinking density and suppresses permeation | transmission of a solvent etc. by increasing content of the isocyanate compound of a contact bonding layer, barrier property is not enough. In particular, when the content contains a strong penetrating amine-based curing agent used for an epoxy-based adhesive, there is a problem that the appearance of the adhesive layer is poor due to delamination.

  Therefore, even when a packaged object containing a highly permeable solvent is packaged, swelling of the adhesive layer is suppressed, appearance defects due to delamination are suppressed, and thickness is reduced. Development of a multilayer film capable of forming a packaging bag is required. Moreover, development of the barrier-type sealant which can form the said multilayer film and packaging bag is calculated | required.

  The present invention has been made in view of the above problems, and even when a packaged object containing a highly permeable solvent or the like is packaged, swelling of the adhesive layer is suppressed, and appearance due to delamination An object of the present invention is to provide a multilayer film capable of forming a packaging bag in which defects are suppressed and the thickness is reduced. In the present invention, even when a packaged object that is formed of the multilayer film and contains a highly permeable solvent or the like is packaged, appearance defects due to delamination are suppressed, and the thickness is reduced. The purpose is to provide a packaging bag. Another object of the present invention is to provide a barrier sealant capable of forming the multilayer film and the packaging bag.

  As a result of intensive studies to achieve the above object, the present inventors have at least a coating layer and a heat-fusible polyolefin resin layer, and the coating layer has a polyvinyl alcohol copolymer having an amino group in the side chain. It has at least an adhesive layer, a coating layer and a heat-fusible polyolefin resin layer in this order on the barrier sealant containing the polymer and the base film, and the coating layer has an amino group in the side chain. According to the multilayer film containing the polyvinyl alcohol copolymer, the inventors have found that the above object can be achieved, and have completed the present invention.

That is, the present invention relates to the following barrier sealant, multilayer film and packaging bag.
1. A barrier sealant comprising at least a coating layer and a heat-fusible polyolefin resin layer, wherein the coating layer contains a polyvinyl alcohol copolymer having an amino group in a side chain.
2. On the base film, at least an adhesive layer, a coating layer, and a heat-sealable polyolefin resin layer are provided in this order, and the coating layer contains a polyvinyl alcohol copolymer having an amino group in the side chain. the film.
3. Item 3. The multilayer film according to Item 2, further comprising a barrier layer between the base film and the adhesive layer.
4). Item 4. The multilayer film according to Item 3, wherein the barrier layer is formed by depositing aluminum, aluminum oxide, or silica on at least one surface of the resin film.
5. Item 4. The multilayer film according to Item 3, wherein the barrier layer contains at least one selected from metaxylylenediamine and an ethylene-vinyl alcohol copolymer.
6). Item 4. The multilayer film according to Item 3, wherein the barrier layer is a metal foil.
7). Item 7. The multilayer film according to any one of Items 2 to 6, wherein the interlayer adhesive strength between the base film and the coating layer is 300 gf / 15 mm or more as measured by a measurement method based on JIS Z0238.
8). The packaging bag which consists of a multilayer film in any one of claim | item 2 -7.

  The multilayer film of the present invention has an excellent barrier property against a solvent or the like having a highly permeable film. Therefore, even when a packaged object containing a highly permeable solvent or the like is packaged, Swelling is suppressed and appearance defects due to delamination can be suppressed. In addition, the multilayer film of the present invention is excellent in adhesive strength between the adhesive layer and the coating layer, and also excellent in adhesive strength between the coating layer and the heat-fusible polyolefin resin layer. It is not necessary to provide a layer for further improving the adhesiveness between them, and the thickness is reduced. In addition, since the packaging bag of the present invention is formed of the multilayer film, it can suppress appearance defects due to delamination even when a package containing a highly permeable solvent or the like is packaged. And the thickness is reduced. Furthermore, since the barrier sealant of the present invention has an excellent barrier property against a solvent or the like having a highly permeable film, and the adhesive force between the coated layer and the heat-fusible polyolefin resin layer, these layers It is not necessary to provide a layer for further improving the adhesion between the two, and the thickness is reduced. For this reason, according to the barrier sealant of the present invention, the above-mentioned multilayer film and packaging bag can be formed.

It is sectional drawing which shows an example of the layer structure of the multilayer film of this invention. It is sectional drawing which shows an example of the layer structure of the multilayer film of this invention. It is sectional drawing which shows an example of the layer structure of the barriering sealant of this invention.

  Hereinafter, the barrier sealant, multilayer film and packaging bag of the present invention will be described in detail.

1. Multilayer film The multilayer film of the present invention has at least an adhesive layer, a coating layer, and a heat-sealable polyolefin resin layer in this order on a base film, and the coating layer has a polyvinyl group having an amino group in a side chain. Contains an alcohol copolymer. The multilayer film of the present invention having the above-described configuration has a coating layer between the heat-fusible polyolefin resin layer and the adhesive layer, and the coating layer has a polyvinyl alcohol copolymer having an amino group in the side chain. Since it contains a polymer, it has excellent barrier properties against highly permeable solvents. For this reason, even when a package containing a highly permeable solvent or the like is packaged using a multilayer film, the heat-sealable polyolefin resin layer as a heat seal layer is a layer on the package side. By forming the packaging bag with the base film as the outer layer, swelling of the adhesive layer can be suppressed and appearance defects due to delamination of the multilayer film can be suppressed. In addition, the multilayer film of the present invention is excellent in adhesive strength between the adhesive layer and the coating layer, and also excellent in adhesive strength between the coating layer and the heat-fusible polyolefin resin layer. It is not necessary to provide a layer for further improving the adhesiveness between them, and the thickness is reduced.

  The layer structure of the multilayer film of the present invention is not particularly limited as long as it has at least an adhesive layer, a coating layer, and a heat-fusible polyolefin resin layer in this order on the base film. 1 and 2 are cross-sectional views showing an example of the layer structure of the multilayer film of the present invention. In FIG. 1, the multilayer film of the present invention is a layer having an adhesive layer 2, a coating layer 3, and a heat-fusible polyolefin-based resin layer 4 on a base film 1 in this order from the top to the bottom of the paper. It has a configuration. In FIG. 2, the multilayer film of the present invention includes an adhesive layer (ii) 6, a barrier layer 5, an adhesive layer 2, a coating layer 3, and a heat-sealable polyolefin resin layer on a base film 1. 4 is a layer structure having 4 in this order from the top to the bottom of the drawing. 1 and 2, “on the base film” indicates that the base film 1 is on the surface on which the adhesive layer 2 or the adhesive layer (ii) 6 is laminated. When forming a packaging bag using the multilayer film of the present invention, the base film 1 is a layer located on the outer surface of the packaging bag, and the heat-sealable polyolefin resin layer 4 is located on the inner surface of the packaging bag. It is.

  The multilayer film of the present invention preferably has no other layer between the heat-fusible polyolefin resin layer 4 and the coating layer 3. By not having another layer between the heat-fusible polyolefin resin layer 4 and the coating layer 3, the thickness of the multilayer film of the present invention can be further reduced.

(Heat-bonding polyolefin resin layer)
The heat-sealable polyolefin resin layer is a layer that imparts heat sealability to the multilayer film of the present invention, and is a layer that is positioned on the inner surface of the packaging bag when the packaging bag is formed using the multilayer film.

  The heat-sealable polyolefin resin for forming the heat-sealable polyolefin resin layer is not particularly limited as long as heat sealability can be imparted to the heat-sealable polyolefin resin layer. Examples of such heat-fusible polyolefin resins include homopolypropylene (PP); homopolyethylene such as low density polyethylene (LDPE) and high density polyethylene (HDPE); linear low density polyethylene (LLDPE) and the like. Can be mentioned. Among these, linear low density polyethylene is preferable in that it can exhibit stronger heat sealability. The said polyolefin resin may be used independently and may use 2 or more types together.

  The linear low-density polyethylene can be obtained by copolymerizing ethylene and α-olefin using a single-site catalyst such as a Ziegler catalyst or a metallocene catalyst. The density range can be controlled by adjusting. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and the like. The α-olefin may be used alone or in combination of two or more.

  Other additives such as an antioxidant, a lubricant, and a pigment may be added to the heat-fusible polyolefin resin layer as long as the effects of the present invention are not impaired. The content of the other additive is about 1 to 10% by mass with the heat-fusible polyolefin resin layer as 100% by mass.

  The thickness of the heat-fusible polyolefin resin layer is not particularly limited, and is preferably 20 to 200 μm, and more preferably 40 to 100 μm. By setting the thickness of the heat-fusible polyolefin resin layer in the above range, the thickness of the multilayer film of the present invention does not become too thick, and more excellent heat sealability can be exhibited.

(Coating layer)
The coating layer is a layer that is located between the heat-fusible polyolefin resin layer and the adhesive layer, and exhibits barrier properties against a highly permeable solvent or the like to suppress swelling of the adhesive layer. .

  The coating layer contains a polyvinyl alcohol copolymer having an amino group in the side chain. The polyvinyl alcohol polymer having an amino group in the side chain is not particularly limited as long as it has an amino group in the side chain and has a vinyl alcohol structural unit. The thing containing the structural unit which has an amino group shown by (1) is mentioned.

In the formula, R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group, or a formyl group.

In the above formula (1), R ₁ is preferably a hydrogen atom. R ₂ is preferably a hydrogen atom or a formyl group, and more preferably a hydrogen atom.

  The polyvinyl alcohol polymer preferably contains 0.1 to 30 mol% of the structural unit having an amino group represented by the above formula (1) with respect to 100 mol% of all structural units of the polyvinyl alcohol polymer. . When the polyvinyl alcohol-based polymer contains the structural unit having an amino group in the above range, the adhesive force between the coating layer and the heat-fusible polyolefin-based resin layer is further improved.

  As the polyvinyl alcohol polymer having an amino group in the side chain, as shown in the general formula (1), a carbon atom constituting the main chain of the polyvinyl alcohol polymer and a nitrogen atom constituting the amino group And are not limited to those containing structural units directly linked to each other. For example, what contains the structural unit which has a hydrocarbon group etc. between the carbon atom which comprises the principal chain of a polyvinyl alcohol-type polymer, and the nitrogen atom which comprises an amino group can be used.

  The polyvinyl alcohol-based polymer preferably further contains a vinyl alcohol structural unit represented by the following general formula (2).

  By including such a vinyl alcohol structural unit, the water solubility of the resin composition for forming the coating layer is further improved, and the compatibility with water as a solvent is further improved. Is further improved.

  The polyvinyl alcohol-based polymer preferably contains 49 to 99.4 mol% of the vinyl alcohol structural unit represented by the above formula (2) with respect to 100 mol% of all structural units of the polyvinyl alcohol-based polymer. It is more preferable to contain -99 mol%. When the polyvinyl alcohol polymer contains the vinyl alcohol structural unit in the above range, the water solubility of the resin composition for forming the coating layer is further improved, and the compatibility with water as a solvent is further improved. The coating suitability of the resin composition is further improved.

  The polyvinyl alcohol polymer may further contain a vinyl alkyl ester structural unit represented by the following general formula (3).

In the formula, R ₃ represents a hydrogen atom or an alkyl group.

In the above formula (3), R ₃ is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and still more preferably a methyl group.

  The polyvinyl alcohol polymer is composed of a vinyl alcohol structural unit represented by the above formula (2) and a vinyl alkyl ester structural unit represented by the above formula (3), and the total of these polyvinyl alcohol polymers. It is preferable to contain 70-99.9 mol% with respect to 100 mol% of structural units, and it is more preferable to contain 70-99.5 mol%.

  The polyvinyl alcohol-based polymer preferably does not substantially contain the vinyl alkyl ester structural unit represented by the above formula (3). When the polyvinyl alcohol-based polymer does not substantially contain the vinyl alkyl ester structural unit represented by the above formula (3), the coating layer can exhibit higher barrier properties.

  As the polyvinyl alcohol polymer having an amino group in the side chain, a polyvinyl alcohol polymer represented by the following general formula (4) can be preferably used.

  In the formula, m, n, x and y are numbers indicating the mol% of each structural unit in the polyvinyl alcohol polymer, and m and n are numbers such that m + n is 70 to 99.9, x and y are numbers such that x + y is 0.1 to 30. In addition, n is preferably a number from 70 to 99.9, y is preferably a number from 0.1 to 30, m is preferably a number from 0 to 0.01, and x is preferably Is a number from 0 to 0.01.

  By using the polyvinyl alcohol polymer represented by the general formula (4) as the polyvinyl alcohol polymer having an amino group in the side chain, the adhesive force between the coating layer and the heat-sealable polyolefin resin layer can be further increased. The water solubility of the resin composition for forming the coating layer is further improved, and the compatibility with water as the solvent is further improved, so that the coating suitability of the resin composition is further improved.

  The polyvinyl alcohol-based polymer having an amino group in the side chain may be a copolymer obtained by further copolymerizing other monomers within the range not impairing the object of the present invention. Examples of such other monomers include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, α-octadecene, acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid and the like. Unsaturated acids or salts thereof, mono- or dialkyl esters, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide and methacrylamide, olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid and methallyl sulfonic acid, or Its salts, alkyl vinyl ethers, N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallyl vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinyl chloride , Polyoxyalkylene (meth) allyl ethers such as polyoxyethylene (meth) allyl ether, polyoxypropylene (meth) allyl ether, polyoxyalkylenes such as polyoxyethylene (meth) acrylate, polyoxypropylene (meth) acrylate ( Polyoxyalkylene (meth) acrylamides such as (meth) acrylate, polyoxyethylene (meth) acrylamide, polyoxypropylene (meth) acrylamide, polyoxyethylene (1- (meth) acrylamide-1,1-dimethylpropyl) ester, poly Oxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene Or the like can be mentioned vinyl amine.

  The polyvinyl alcohol polymer having an amino group in the side chain preferably has a saponification degree of 70 to 99.9 mol%. By setting the degree of saponification within the above range, the coating layer can exhibit higher barrier properties.

  The degree of saponification refers to the vinyl alcohol polymer having an amino group, the vinyl alcohol structural unit represented by the general formula (2), and the vinyl alkyl ester structural unit represented by the general formula (3). The ratio of the vinyl alcohol structural unit represented by the general formula (2) with respect to the total is expressed in mol%. For example, in the polyvinyl alcohol polymer represented by the general formula (4), {n ÷ (N + m)} × 100.

  The weight average molecular weight of the polyvinyl alcohol polymer having an amino group is preferably 5,000 to 2,000,000 g / mol. More preferably, it is 10,000-1,500,000 g / mol, More preferably, it is 15,000-1,000,000 g / mol, Especially preferably, it is 20,000-500,000 g / mol.

  It does not specifically limit as a method to manufacture the said polyvinyl alcohol-type polymer which has an amino group, It can manufacture by a conventionally well-known method. As such a production method, vinyl formamide and vinyl alkyl esters are copolymerized, the formyl group of the obtained copolymer is hydrolyzed to form an amino group, and the alkyl ester group is hydrolyzed to hydroxyl group. The manufacturing method which forms group is mentioned.

  Examples of the method for producing the polyvinyl alcohol polymer having an amino group include (a) 99 to 1 mol% of N-vinylformamide and (b) 1 to 99 mol% of one or more kinds of vinyl C1-C10. C1-C10 alkyl from copolymerized unit (b) is copolymerized and then hydrolyzed from 30 to 100 mol% of formyl groups from copolymerized unit (a) to form amino groups. The manufacturing method which hydrolyzes 30 to 100 mol% of ester groups and forms a hydroxyl group is mentioned.

Specifically, the manufacturing method is a manufacturing method including the following steps.
a) Charge the first portion of the total amount of N-vinylformamide into the reactor;
b) charging a first portion of the total amount of at least one vinyl C1-C10 alkyl ester into the reactor;
c) continuously feeding a first portion of the total amount of free radical polymerization catalyst into the reactor at a first catalyst flow rate;
d) contacting a first portion of N-vinylformamide, a first portion of at least one vinyl C1-C10 alkyl ester in the presence of a free radical polymerization catalyst under polymerization conditions for a first period;
e) After the first period, under polymerization conditions until the total amount of N-vinylformamide, the total amount of vinyl C1-C10 alkyl ester, and the total amount of free radical polymerization catalyst are fed into the reactor, the second period During which time a second portion of N-vinylformamide is continuously fed into the reactor in at least 4 hours, while at the same time a second portion of at least one vinyl C1-C10 alkyl ester is introduced into the reactor. -Feeding simultaneously with vinylformamide and simultaneously feeding the second part of the free radical polymerization catalyst into the reactor to produce an intermediate copolymer containing polyvinylformamide and one or more polyvinyl C1-C10 alkyl esters Here, in the third period, the solid content of the intermediate copolymer in the reactor is about 20 wt% or more and about 70 wt% or less. Sometimes it ends; Next, after the step of removing the polymerizable monomer unreacted give Intermediate copolymer.
f) The copolymer is saponified under either acidic or basic conditions to produce an intermediate polyvinylamide-polyvinyl alcohol copolymer;
g) The intermediate polyvinylamide-polyvinyl alcohol copolymer is hydrolyzed under either acidic or basic conditions to produce a water soluble copolymer.
h) This is washed in the presence of methanol and subjected to a dehydration drying step to obtain a water-soluble copolymer.

  The thickness of the coating layer is not particularly limited and is preferably 0.1 to 2 μm, more preferably 0.3 to 1 μm. By setting the thickness of the coating layer within the above range, the coating layer exhibits higher barrier properties, the thickness of the coating layer does not become too thick, and the cost can be further reduced.

(Adhesive layer)
An adhesive bond layer is a layer which is laminated | stacked between a membrane | film | coat layer and a base film in the multilayer film of this invention, and improves interlayer adhesiveness.

  The adhesive for forming the adhesive layer is not particularly limited as long as the above-described coating layer can be bonded to a base film or a barrier layer described later. Examples of such an adhesive include a two-component reactive polyurethane adhesive, a two-component reactive polyester adhesive, and a two-component reactive epoxy adhesive that are used by mixing a main agent and a curing agent. It is done.

  The main agent preferably has two or more hydroxy groups in one molecule, and at least one selected from the group consisting of an epoxy group, a urethane group and a carbonate group in which a part of the hydroxyl groups at the end of the main chain is present. It is more preferable to use one modified with the above group. Of these, those that are epoxy-modified are more preferred. These may be used alone or in combination of two or more.

  A commercial item can be used as such a main ingredient, for example, A616, A310, XCS-1000 by Mitsui Chemicals, etc. are mentioned.

  As the curing agent, a compound having two or more isocyanate groups in one molecule is preferable. For example, 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4-diphenylmethane diisocyanate (2,4- MDI), 2,2′-diphenylmethane diisocyanate (2,2′-MDI), carbodiimide modified diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, carbodiimidized diphenylmethane polyisocyanate, tolylene diisocyanate (TDI, 2,4, 2, 6 or a mixture thereof), xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate, phenylene diisocyanate, hexamethyle Diisocyanate (HDI), dimer acid diisocyanate, norbornene diisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate (hydrogenated XDI) ), Cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate. These may be used alone or in combination of two or more.

  A commercial item can be used as such a hardening | curing agent, for example, A65, A3 by Mitsui Chemicals, etc. are mentioned.

  The thickness of an adhesive bond layer is not specifically limited, 0.2-5 micrometers is preferable and 0.5-1.5 micrometers is more preferable. By setting the thickness of the adhesive layer in the above range, the thickness of the multilayer film of the present invention does not become too thick, and even better interlayer adhesion can be exhibited.

(Base film)
The base film is a layer located on the outer surface of the packaging bag when the above-mentioned adhesive layer or the like is laminated in the multilayer film of the present invention and a packaging bag is formed using the multilayer film.

  It does not specifically limit as resin which forms a base film, For example, Polyamide resin, such as nylon; Polyolefin resin, such as polyethylene resin and a polypropylene resin; Cyclic polyolefin resin; Polystyrene resin; Acrylonitrile-styrene copolymer (AS resin); Acrylonitrile-butadiene-styrene copolymer (ABS resin); Poly (meth) acrylic resin; Polycarbonate resin; Polyvinyl alcohol resin; Saponified ethylene-vinyl ester copolymer (EVOH resin); Polyester such as polyethylene terephthalate and polyethylene naphthalate A resin film selected from a resin; a polyurethane resin; an acetal resin; and a cellulosic resin can be suitably used. Such a resin film may be an unstretched film or a film stretched in a uniaxial direction or a biaxial direction. These may be used alone or in combination of two or more.

  If the base film is within the range not impairing the effects of the present invention, other additives such as silica may be added. The content of other additives is about 0.1 to 5% by mass, with the base material layer being 100% by mass.

  The thickness of a base film is not specifically limited, 5-100 micrometers is preferable and 10-50 micrometers is more preferable.

(Barrier layer)
The multilayer film of the present invention may further have a barrier layer between the base film and the adhesive layer. By having a barrier layer, the barrier property of the multilayer film of the present invention can be further improved.

  The barrier layer is not particularly limited as long as the barrier property can be imparted to the multilayer film. For example, a metal foil such as an aluminum foil, a copper foil, or a stainless steel foil; aluminum on at least one surface of a resin film such as a polyethylene terephthalate film; Further, a laminate obtained by laminating thin films such as silicon oxide such as aluminum oxide and silica, alumina, and the like by vapor deposition can be suitably used.

  As the barrier layer, a resin film formed of a resin containing metaxylylenediamine, an ethylene-vinyl alcohol copolymer, or the like can be suitably used. These resins may be used alone or in combination of two or more.

  The thickness of a barrier layer is not specifically limited, 2-50 micrometers is preferable and 5-30 micrometers is more preferable.

  When the multilayer film of the present invention has the barrier layer, an adhesive layer (ii) may be further provided between the base film and the barrier layer. By having the adhesive layer (ii), interlayer adhesion between the base film and the barrier layer can be further improved.

  The configuration of the adhesive, thickness, etc., forming the adhesive layer (ii) is the same as that of the adhesive layer.

  30-500 micrometers is preferable and, as for the total thickness of the multilayer film of this invention, 50-200 micrometers is more preferable.

  The multilayer film of the present invention preferably has an interlayer adhesive strength between the base film and the coating layer of 300 gf / 15 mm or more, more preferably 400 gf / 15 mm or more, as measured by a measurement method based on JIS Z0238. Moreover, although the upper limit of the said interlayer adhesive strength is not specifically limited, 2000 gf / 15mm is preferable and 1000 gf / 15mm is more preferable. In addition, when the multilayer film of this invention has the said barrier layer, the interlayer adhesive strength between a barrier layer and a film layer should just be the said range.

  Since the multilayer film of the present invention has the above-described configuration, it can be suitably used as a multilayer laminate film.

2. Barrier Sealant The present invention also includes at least a film layer and a heat-sealable polyolefin resin layer, and the film layer is also a barrier sealant containing a polyvinyl alcohol copolymer having an amino group in the side chain. . The barrier sealant of the present invention has at least a coating layer and a heat-fusible polyolefin-based resin layer, and the coating layer contains a polyvinyl alcohol-based copolymer having an amino group in the side chain. By using it for forming a multilayer film, a coating layer and a heat-fusible polyolefin resin layer can be applied to the multilayer film. For this reason, according to the barrier sealant of the present invention, the above-mentioned multilayer film and a packaging bag described later can be formed.

  The film layer and the heat-sealable polyolefin resin layer that form the barrier sealant are the same as the film layer and the heat-sealable polyolefin resin layer described in the above multilayer film.

  FIG. 3 shows an example of the layer structure of the barrier sealant of the present invention. FIG. 3 is a cross-sectional view showing an example of the layer structure of the barrier sealant of the present invention. In FIG. 3, the barrier sealant of the present invention has a layer structure having a coating layer 3 and a heat-fusible polyolefin resin layer 4 in this order from the top to the bottom of the paper. When forming a multilayer film using the barrier sealant of the present invention, the adhesive layer 2 may be formed on the coating layer 3 as shown in FIG.

  The barrier sealant of the present invention preferably has no other layer such as an adhesive layer between the heat-fusible polyolefin resin layer 4 and the coating layer 3. By not having another layer between the heat-fusible polyolefin-based resin layer 4 and the coating layer 3, the thickness of the barrier sealant of the present invention can be further reduced, whereby the multilayer of the present invention can be reduced. The thickness of the film can be further reduced. Further, since the barrier sealant of the present invention does not have other layers such as an adhesive layer between the heat-fusible polyolefin resin layer 4 and the coating layer 3, the coating layer 4 has amino groups in the side chain. Combined with the fact that it contains a polyvinyl alcohol copolymer having a group and is less likely to swell with a solvent or the like, the peeling between the heat-fusible polyolefin resin layer 4 and the coating layer 3 is further suppressed.

3. Packaging Bag The present invention is also a packaging bag made of the multilayer film. By forming the multilayer film into a bag shape so that the heat-fusible polyolefin resin layer is on the inside and the base film is on the outside, the coating layer has excellent barrier properties against highly permeable solvents, etc. Therefore, even when a packaged object containing a highly permeable solvent is packaged, the adhesive layer is prevented from swelling, and a packaging bag in which poor appearance due to delamination is suppressed can be obtained. it can.

  The method for manufacturing the packaging bag is not particularly limited, and two planar multilayer films are laminated so that the surfaces on which the heat-fusible polyolefin resin layer is formed are in contact with each other. The method of sealing by heat laminating and making it into a bag shape etc. is mentioned.

  Examples of the present invention will be described below. The present invention is not limited to the following examples.

(Evaluation of multilayer film)
Example 1
A linear low density polyethylene (LLDPE) film (manufactured by Toyobo Co., Ltd .: trade name L4102, thickness 70 μm) was prepared as the heat-sealable polyolefin resin layer. Next, as a resin for forming the coating layer, a polyvinyl alcohol copolymer having an amino group in the side chain (Selvol (trade name) 5003 manufactured by Seki Swiss Specialty Chemical Co., Ltd.) is prepared and dissolved in water to prepare a solution. did. The solution is subjected to corona treatment on one surface of the heat-fusible polyolefin resin layer, the solution prepared on the surface is applied, and dried at 80 ° C. for 1 minute, on the heat-fusible polyolefin resin layer. A film layer having a thickness of 0.4 μm was formed.

  Subsequently, as an adhesive for forming the adhesive layer, a polyurethane resin two-component reactive adhesive, manufactured by Mitsui Chemicals, Inc .: trade name A616 (main agent), trade name A65 (curing agent) in a mass ratio of 16: 1 It mixed by ratio and apply | coated to the surface of the membrane | film | coat layer so that it might become a thickness of 2 micrometers.

  As a metal foil for forming the barrier layer, an aluminum foil (1N30, thickness 9 μm) manufactured by Niskin Co., Ltd. was prepared and laminated on the adhesive applied to the surface of the coating layer.

  Next, as an adhesive for forming the adhesive layer 2, a polyurethane resin two-component reactive adhesive, manufactured by Mitsui Chemicals, Inc .: trade name A616 (main agent), trade name A65 (curing agent) with a mass ratio of 16: 1 It mixed by mass ratio and apply | coated to the surface of a barrier layer.

  Finally, a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd .: trade name E5102, thickness 12 μm) is prepared as a base film, laminated on the adhesive applied to the surface of the barrier layer, and dried at 45 ° C. for 3 days. Then, an adhesive layer 2 having a thickness of 2 μm and a base film were formed on the barrier layer to produce a multilayer film. The total thickness of the obtained multilayer film was 95.4 μm.

Examples 2-8, Comparative Examples 1-7
A multilayer film was produced in the same manner as in Example 1 except that the formulation shown in Tables 1 and 2 was changed.

In Tables 1 and 2, the raw materials used are as follows.
E5102: Polyethylene terephthalate (PET) manufactured by Toyobo
N1102: Biaxially stretched nylon (ONY) manufactured by Toyobo
P2161: Biaxially oriented polypropylene (OPP) manufactured by Toyobo
A616: Main component of polyurethane resin-based two-component reactive adhesives made by Mitsui Chemicals
A65: Curing agent for polyurethane resin-based two-component reactive adhesives made by Mitsui Chemicals
A310: Main component of polyurethane resin-based two-component reactive adhesives made by Mitsui Chemicals
XCS-1000: Main component of polyurethane resin-based two-component reactive adhesives made by Mitsui Chemicals
A3: Curing agent for polyurethane resin two-component reactive adhesives Mitsui Chemicals' Oribain BPS1109: Epoxy resin-based two-component reactive adhesives Tokyo Ink's Olivevine BHS8515: Epoxy resin two-component reactive adhesives Curing agent made by Tokyo Ink
AL: Aluminum foil 1N30 Nikkin Tech Barrier L: Silica-deposited polyethylene terephthalate film (Tvm-PET) Mitsubishi Plastics MX112: MXD barrier nylon film (BON) Toyobo
Selvol5003: Polyvinyl alcohol copolymer with amino group in the side chain
Selvol205: Polyvinyl alcohol copolymer with no amino group in the side chain
L4102: Linear low density polyethylene (LLDPE) film (containing 0.2% by mass of silica) Toyobo AL-1: Linear low density polyethylene (LLDPE) film Tamapoly

(Manufacture of packaging bags)
The obtained multilayer films of Examples and Comparative Examples were cut into a size of 100 mm × 165 mm and pouched to produce a packaging bag.

(Preparation of test piece)
Modified polyamidoamines, modified aliphatic polyamines, and modified alicyclic polyamines were prepared as contents (packages). A packaging bag filled with 10 g of the contents was prepared for each content, and the opening of the packaging bag was sealed by heat sealing to prepare a test piece. Moreover, the sealed packaging bag was put into 50 degreeC oven, and it was left to stand for one week or two weeks, and the test piece after an acceleration test was prepared.

  The following evaluation was performed using the test piece and the test piece after the acceleration test.

<Interlayer adhesion strength>
The interlayer adhesion strength between the coating layer and the substrate film was measured by a measuring method based on JIS Z0238 under the conditions of a tensile speed of 50 mm / min and a test piece width of 15 mm. In addition, when the barrier layer was formed, the interlayer adhesive strength between a membrane | film | coat layer and a barrier layer was measured.

<Poor appearance>
The test piece and the test piece after the acceleration test were visually observed for each content, and evaluated according to the following evaluation criteria.
○: Lami float (external appearance defect) is not seen at all.
(Triangle | delta): The stripe-like lame float has generate | occur | produced a little.
X: A lot of streaky Lami floats are generated.

  The results are shown in Tables 1 and 2.

(Evaluation of barrier sealant)
By the method described in Example 1 and Comparative Example 1 described above, a coating layer having a thickness of 0.4 μm was formed on a heat-sealable polyolefin-based resin layer having a thickness of 70 μm, thereby producing a barrier sealant.

Comparative Example 8
A film layer was not formed on the heat-sealable polyolefin resin layer, that is, a heat-sealable polyolefin resin layer having a thickness of 70 μm was used as the sealant of Comparative Example 8.

  The following evaluation was performed using the obtained barrier sealant of Example 1 and Comparative Example 1 and the sealant of Comparative Example 8.

<Gas barrier properties>
The gas barrier property of the barrier sealant was measured using an oxygen transmission rate measurement device (manufactured by MOCON, model number: OX-TRAN2 / 22L). The results are shown in Table 3.

<Interlayer adhesion strength>
Using the barrier sealant of Example 1 and Comparative Example 1, multilayer films of Example 1 and Comparative Example 1 were produced, and interlayer adhesion strength was measured. The results are as shown in Tables 1 and 2.

DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Adhesive layer 3 ... Film | membrane layer 4 ... Heat-fusible polyolefin resin layer 5 ... Barrier layer 6 ... Adhesive layer (ii)

Claims (8)

  A barrier sealant comprising at least a coating layer and a heat-fusible polyolefin resin layer, wherein the coating layer contains a polyvinyl alcohol copolymer having an amino group in a side chain.   On the base film, at least an adhesive layer, a coating layer, and a heat-sealable polyolefin resin layer are provided in this order, and the coating layer contains a polyvinyl alcohol copolymer having an amino group in the side chain. the film.   The multilayer film according to claim 2, further comprising a barrier layer between the base film and the adhesive layer.   The multilayer film according to claim 3, wherein the barrier layer is formed by depositing aluminum, aluminum oxide, or silica on at least one surface of the resin film.   The multilayer film according to claim 3, wherein the barrier layer contains at least one selected from metaxylylenediamine and an ethylene-vinyl alcohol copolymer.   The multilayer film according to claim 3, wherein the barrier layer is a metal foil.   The multilayer film in any one of Claims 2-6 whose interlayer adhesive strength between a base film and a membrane | film | coat layer measured by the measuring method based on JISZ0238 is 300 gf / 15mm or more.   The packaging bag which consists of a multilayer film in any one of Claims 2-7.