WO2019039555A1 - Multilayered film, laminate, production method for laminate, and air bag - Google Patents

Abstract

A multilayered film to be bonded to fabric, the multilayered film comprising an adhesive layer to be bonded to the fabric and an airtight layer bonded to the adhesive layer, wherein the adhesive layer comprises an olefin-based polymer containing epoxy groups and the airtight layer has a higher melting point than the adhesive layer.

Description

Multilayer film, laminate, method of producing laminate, and airbag

The present invention relates to a multilayer film, a laminate, a method of manufacturing a laminate, and an air bag.

Conventionally, a laminate having a base fabric and a film laminated thereon is known. For example, Patent Document 1 discloses a laminate used as a vehicle air bag, in which a film is dry-laminated on a woven fabric having warp yarns and weft yarns.

International Publication No. 2015/065273

By the way, the above-mentioned laminate may be used in an environment where temperature or humidity or both are high. Therefore, in recent years, the laminated body is required to improve the durability under such a severe environment.

However, in the invention described in Patent Document 1, the durability of the laminate at high temperature and / or high humidity is not studied at all.

In view of the above-mentioned point, one form of the present invention makes it a subject to provide a multilayer film which enables manufacture of a layered product excellent in endurance under high temperature and / or a high humidity environment.

In order to solve the above problems, an embodiment of the present invention is a multilayer film used by bonding to a base fabric, and an adhesive layer to be bonded to the base fabric and the adhesive layer And the adhesive layer comprises an olefin-based polymer containing an epoxy group, and the melting point of the hermetic layer is higher than the melting point of the adhesive layer.

According to one aspect of the present invention, it is possible to provide a multilayer film that enables the production of a laminate excellent in durability under high temperature and / or high humidity environments.

1 is a schematic cross-sectional view of a multilayer film according to an aspect of the present invention. 1 is a schematic cross-sectional view of a multilayer film according to an aspect of the present invention. 1 is a schematic cross-sectional view of a multilayer film according to an aspect of the present invention. It is a typical sectional view of a layered product by one form of the present invention. It is a typical sectional view of a layered product by one form of the present invention. FIG. 1 is a schematic view of an apparatus for manufacturing a laminate according to an aspect of the present invention. It is a schematic diagram explaining lamination | stacking with the base fabric and multilayer film in the manufacturing process of the laminated body by one form of this invention.

(Multilayer film)
A multilayer film according to one aspect of the present invention is used by bonding to a base fabric, and has an adhesive layer on the side to be bonded to the base fabric and an airtight layer bonded to the adhesive layer. The adhesive layer contains an olefin-based polymer containing an epoxy group, and the melting point of the hermetic layer is higher than the melting point of the adhesive layer.

In FIG. 1, an example of a multilayer film is shown by typical sectional drawing. In the example of FIG. 1, the multilayer film 1 comprises a gas-tight layer 4 and an adhesive layer 2 bonded to the gas-tight layer 4, ie directly bonded to the gas-tight layer 4. The multilayer film 1 can be used by being adhered to a base cloth, and in the case of adhesion, the adhesive layer 2 is the side to be adhered to the base cloth. When the multilayer film 1 is adhered to the base fabric to form a laminate 10 as shown in FIG. 4, the adhesive layer 2 is directly laminated to the base fabric 8 and in the obtained laminate 10 It becomes an inner layer sandwiched between the cloth 8 and the airtight layer 4. Therefore, the adhesive layer 2 can be said to be a layer which bonds the airtight layer 4 and the base fabric 8.

In the present specification, the airtight layer is a layer having a function of preventing gas from flowing in and out of the layer (hereinafter, also referred to as an airtight function). The adhesive layer is a layer exhibiting adhesion to the base fabric, and the adhesion is exhibited by softening or melting under predetermined conditions, for example, under conditions of increased temperature and / or pressure. It may be

In this embodiment, the multilayer film has an adhesive layer containing an olefin-based polymer containing an epoxy group, whereby the multilayer film is adhered to a base fabric to produce a laminate; A laminate excellent in durability under the environment can be obtained. In addition, in this specification, high temperature refers to the temperature exceeding normal temperature, and high humidity refers to the humidity exceeding normal humidity. Here, normal temperature refers to a temperature range of 5 to 35 ° C., and normal humidity refers to a range of relative humidity of 45 to 85%. Therefore, the multilayer film of the present embodiment can exhibit excellent durability even after being stored for a predetermined time under conditions of a temperature above 35 ° C. and / or a relative humidity above 85%. In addition, the multilayer film of the present embodiment preferably has a temperature of 50 ° C. or more, more preferably 70 ° C. or more, and / or a humidity of 90% or more, more preferably 95% or more. Can also exhibit excellent durability. In addition, excellent durability can be exhibited even after storage under the above-described high temperature and high humidity conditions, for example, 84 hours or more, more preferably 168 hours or more, and still more preferably 408 hours or more.

The durability of the laminate is obtained, for example, by bonding a multilayer film and a base fabric to prepare a laminate, and storing the laminate under a high temperature and / or high humidity environment as described above for a predetermined time, It can be evaluated by measuring the delamination resistance (peel strength or breaking strength) between the multilayer film and the base fabric. The evaluation of the delamination resistance can include the evaluation of the delamination resistance between layers in the multilayer film.

The multilayer film has a multilayer structure having at least two layers having an airtight layer and an adhesive layer. Thereby, each layer can separately have an adhesion function at the time of adhering the multilayer film to the base fabric and an airtight function in the obtained laminate. Therefore, when the multilayer film according to the present embodiment is used, a high-quality laminate that reliably exhibits both the adhesive function and the airtight function of the multilayer film is manufactured as compared to the case where the single layer film is adhered to the base fabric. be able to.

In addition, the melting point of the hermetic layer is higher than the melting point of the adhesive layer. As described above, in the present embodiment, since materials having different heat behavior are used for each of the airtight layer and the adhesive layer, when the multilayer film is heated and adhered to the base fabric, the softening of the airtight layer is suppressed. The adhesive layer can be softened or melted to a softness suitable for adhesion to the backing. As a result, even when the conditions of temperature and pressure at the time of production are changed, the laminate can be produced while achieving both the reliable adhesion to the base cloth and the maintenance of the airtightness of the multilayer film.

As described above, since the adhesive layer can exhibit the adhesive function, the multilayer film can be favorably adhered to the base cloth without using an adhesive or the like separately. Thereby, the effort and cost by use of an adhesive agent can be reduced. Further, when used for a long time or under a high temperature and high humidity environment, it is possible to prevent the laminate from losing its flexibility or causing delamination due to the deterioration of the adhesive.

As used herein, the melting point of a layer is the temperature at which the layer softens when the temperature of the layer is raised, and the molecules of the polymer in the layer begin to move relative to each other, causing the polymer to become fluid. Point to. Therefore, the melting point of the adhesive layer and the hermetic layer can be said to be the melting point of the polymer component (including the polymer alloy) in the adhesive layer and the hermetic layer, respectively. The melting point of such a polymer can be the melting peak temperature measured by differential scanning calorimetry.

(Adhesive layer)
As described above, the adhesive layer is a layer on the side of the base fabric when the multilayer film is adhered to the base fabric, and is a layer showing adhesiveness to the base fabric under predetermined conditions. Furthermore, in the resulting laminate, the adhesive layer can also have an airtight function.

In the present embodiment, the adhesive layer contains an olefin-based polymer containing an epoxy group. Since the adhesive layer contains a polymer containing an epoxy group, it can improve the adhesion to a polyester-containing base fabric under high temperature and / or high humidity environments, so the base fabric and the adhesive layer Between the above and the other can hardly occur, and the durability can be improved.

The olefin-based polymer containing an epoxy group contained in the adhesive layer is preferably a copolymer containing a monomer unit containing an epoxy group and another monomer unit. For example, α-olefin / unsaturated carboxylic acid ester / epoxy It can be a terpolymer (terpolymer) of monomer units having a group.

Examples of α-olefins in terpolymers include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docosene, 1-tetracocene, 1-hexacocene, 1-octacocene, and 1-triaconcene It can be mentioned. The above α-olefins may be contained singly or in combination of two or more in the terpolymer.

The unsaturated carboxylic acid ester in the terpolymer is preferably an alkyl (meth) acrylate. As used herein, "(meth) acrylate" refers to methacrylate and / or acrylate. The alkyl (meth) acrylates include those in which the alkyl group has 1 to 24 carbon atoms. Specific examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. The acrylate may be contained singly or in combination of two or more in the olefin-based polymer containing an epoxy group.

The monomer unit having an epoxy group in the above terpolymer is preferably unsaturated epoxide. Unsaturated epoxides include glycidyl esters and ethers of fatty acids, and esters and ethers of cycloaliphatic glycidyls and the like. Glycidyl esters and ethers of fatty acids include, for example, allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate, glycidyl triconate, and glycidyl (meth) acrylate. Further, as esters and ethers of alicyclic glycidyl, for example, 2-cyclohexene-1-glycidyl ether, cyclohexene-4,5-diglycidyl dicarboxylate, cyclohexene-4-glycidyl carboxylate, 5-norbornene-2- Mention may be made of methyl 2-glycidyl carboxylate and diglycidyl endo-cis-bicyclo [2.2.1] -5-heptene-2,3-diglycidyl carboxylate. Among the above, glycidyl esters of fatty acids are preferable, and glycidyl methacrylate is more preferable, because the adhesion to a base fabric is good. The unsaturated epoxide may be contained singly or in combination of two or more in the olefin-based polymer containing an epoxy group.

Olefin-based polymers containing epoxy groups can be obtained by radical polymerization of the monomers (ie ethylene, alkyl (meth) acrylates and unsaturated epoxides).

The olefin polymer may also be a copolymer obtained by grafting an unsaturated epoxide onto a copolymer of ethylene, an alkyl (meth) acrylate and an optionally used α-olefin, a vinyl ester, or a diene. The grafting procedure itself can be performed by known methods. However, it is preferable that the olefin-based polymer is not an unsaturated epoxide-grafted polymer but a random terpolymer of ethylene / alkyl (meth) acrylate / unsaturated epoxide obtained by copolymerization of the respective monomers. It is more preferable that it is a terpolymer of ethylene / (meth) acrylic ester / glycidyl (meth) acrylate, and even more preferable that it is a terpolymer of ethylene / acrylic ester / glycidyl methacrylate.

The olefin polymer contains a monomer unit other than the above monomer unit, for example, a vinyl ester of a saturated carboxylic acid such as vinyl acetate or vinyl propionate, or a diene such as 1,4-hexadiene. It is also good.

The content of ethylene contained in the above-mentioned olefin-based polymer in the adhesive layer is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 55% by mass with respect to 100% by mass of the olefin-based polymer (terpolymer). The content may be at least parts by weight and / or preferably at most 94% by weight, more preferably at most 87% by weight, and even more preferably at most 75% by weight. The content may be a range defined by any of the lower limit and the upper limit, and may be a range in which any of the lower limit and the upper limit is combined. Hereinafter, the same applies to other components and conditions.

The content of the alkyl (meth) acrylate contained in the above-mentioned olefin-based polymer in the adhesive layer is preferably 5% by mass or more, more preferably 10% by mass or more, with respect to 100% by mass of the olefin-based polymer (terpolymer). More preferably, it may be 20% by mass or more and / or preferably 45% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less.

The content of unsaturated epoxide contained in the olefin polymer in the adhesive layer is preferably 1% by mass or more, more preferably 3% by mass or more, more preferably 100% by mass of the olefin polymer (terpolymer). May be 5% by weight or more and / or preferably 25% by weight or less, more preferably 20% by weight or less, and still more preferably 15% by weight or less. By setting the content of unsaturated epoxide to 1% by mass or more, the adhesion between the adhesive layer and the base fabric containing polyester can be improved, and by setting the content to 25% by mass or less, gelling of the olefin-based polymer Can be prevented.

The content of unsaturated epoxide contained in the above-mentioned olefin-based polymer in the adhesive layer is preferably 0.1% by mass or more, more preferably 1% by mass, and further preferably 100% by mass of the olefin-based polymer (terpolymer) It may be preferably 5% by mass or more and / or preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less. By making content of the monomer which has an epoxy group into 0.1 mass% or more, adhesiveness with the base fabric under high temperature and high humidity can be improved. Moreover, the chemical stability of the adhesive layer can be secured by setting the content to 20% by mass or less.

The content of the epoxy group in the olefin polymer is preferably 0.05% by mass or more, more preferably 0.1% by mass or more and / or preferably 5% by mass or less, more preferably 3% by mass or less can do.

The melting point of the olefin polymer is preferably 50 ° C. or more, more preferably 55 ° C. or more, and / or preferably 150 ° C. or less, more preferably 130 ° C. or less. The melting point of the adhesive layer is also preferably 50 ° C. or more, more preferably 55 ° C. or more, and / or preferably 150 ° C. or less, more preferably 130 ° C. or less. When the melting point of the adhesive layer is 50 ° C. or more, the mechanical strength of the multilayer film and the laminate at normal temperature can be secured, and by the melting point of the adhesive layer being 150 ° C. or less, the multilayer film and the laminate are laminated. Processability can be improved because processing can be performed at a relatively low temperature during manufacture of the body.

The adhesive layer can contain another polymer or copolymer other than the olefin-based polymer containing an epoxy group. Examples of the other polymers that can be contained in the adhesive layer include olefin-based polymers or copolymers that do not contain an epoxy group, such as ethylene / alkyl (meth) acrylate copolymers.

Additives may be added to the adhesive layer in addition to the components described above. The additives include pigments, fillers, antioxidants, hydrolysis stabilizers, antiblocking agents, and the like.

The content of the olefin-based polymer containing an epoxy group in the adhesive layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, based on the total amount of the adhesive layer. Preferably it is 95 mass% or more, More preferably, it can be 99.5 mass% or more. In addition, the polymer component contained in the adhesive layer is preferably made of an olefin-based polymer containing an epoxy group, and the adhesive layer is more preferably made of an olefin-based polymer containing an epoxy group.

The adhesive layer may be a single layer or two or more layers. When there are two or more adhesive layers, for example, two layers of a layer to which a colorant such as a pigment is added and a layer to which a colorant is not added can be used. This makes it possible to reduce the amount of colorant used as compared to the configuration in which the colorant is added to the entire adhesive layer having the same thickness as a whole. The total thickness of the adhesive layer is preferably 5 to 50 μm, more preferably 5 to 30 μm.

(Airtight layer)
As described above, the hermetic layer is a layer having a hermetic function that does not allow gas to flow in and out of the layer. Therefore, for example, when the multilayer film and the laminate of the present embodiment are formed into a bag, when the air is stored inside the bag, the airtight layer has a function to reliably prevent the air from leaking out. Can.

The hermetic layer preferably contains a thermoplastic polymer. The thermoplastic polymer contained in the hermetic layer is not particularly limited, but may be a thermoplastic elastomer or a thermoplastic resin, and is preferably a thermoplastic elastomer. As a thermoplastic elastomer, 1 or more types can be used among an amide type elastomer, an ester type elastomer, an olefin type elastomer, a styrene type elastomer, a urethane type elastomer, and a thermoplastic rubber crosslinked body, for example. Among them, it is preferable to use an amide-based elastomer because of its excellent low temperature properties and flexibility.

The amide-based elastomer preferably has polyamide as a hard segment, and polyester or polyether as a soft segment. Examples of the polyamide in the polyamide elastomer include nylon 6, nylon 6, 6, nylon 11, nylon 12 and the like, among which nylon 12 is preferable. The polyamide-based elastomer may contain the above-mentioned polyamide alone or in combination as a hard segment.

The content of the hard segment in the thermoplastic elastomer in the hermetic layer is preferably 65% by mass or more, more preferably 75% by mass or more, with respect to 100% by mass of the thermoplastic elastomer, and / or It is preferable that it is 95 mass% or less, and it is more preferable that it is 85 mass% or less. In addition, the content of the soft segment in the thermoplastic elastomer in the hermetic layer is preferably 5% by mass or more, more preferably 15% by mass or more, with respect to 100% by mass of the thermoplastic elastomer, and / or It is preferable that it is 35 mass% or less, and it is more preferable that it is 25 mass% or less.

The melting point of the thermoplastic elastomer contained in the hermetic layer is not particularly limited as long as the melting point of the hermetic layer is higher than the melting point of the adhesive layer, but is preferably 100 ° C. or more, more preferably 130 ° C. or more It is preferable that the temperature is 300 ° C. or less, and more preferably 210 ° C. or less. The melting point of the hermetic layer is also preferably 100 ° C. or more, more preferably 130 ° C. or more, and / or preferably 300 ° C. or less, more preferably 210 ° C. or less.

As described above, the melting point of the hermetic layer is higher than the melting point of the adhesive layer, but the difference between the melting point of the hermetic layer and the melting point of the adhesive layer can be preferably 10 ° C. or more, more preferably The temperature can be 30 ° C. or higher, and / or can be 150 ° C. or lower, more preferably 100 ° C. or lower. When bonding a multilayer film to a base fabric using heat, the heating temperature at the time of manufacture may fluctuate somewhat by setting the difference between the melting point of the hermetic layer and the melting point of the adhesive layer in the above range. Even if it is, it is possible to secure the airtight function of the airtight layer and the adhesive function of the adhesive layer. As a result, the occurrence of defective products in which the air tightness is impaired due to failure of the adhesive layer to soften sufficiently and adhesion with the base cloth can not be made well or the air tight layer is deformed or deteriorated The production stability can be improved.

The airtight layer can be blended with a polymer that is not a thermoplastic elastomer, such as polyamide resin, polyester resin, polyolefin resin, polyvinyl chloride, polyurethane, acrylic resin, polycarbonate and the like.

The content of the amide-based elastomer in the hermetic layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more based on the total amount of the hermetic layer. More preferably, it can be 99.5% by mass or more. It is preferable that the polymer component contained in the hermetic layer is made of an amide-based elastomer, and it is more preferable that the hermetic layer be made of an amide-based elastomer.

In addition to the components described above, additives may be added to the hermetic layer. The additives include pigments, fillers, antioxidants, hydrolysis stabilizers, antiblocking agents, and the like.

The hermetic layer may be a single layer or two or more layers. The thickness of the entire hermetic layer is preferably 5 to 50 μm, and more preferably 5 to 30 μm.

(Intermediate layer)
In the multilayer film according to the present embodiment, an intermediate layer can be provided between the hermetic layer and the adhesive layer. In FIG. 2, an example of the multilayer film provided with the intermediate | middle layer is shown with typical sectional drawing. As shown in FIG. 2, the multilayer film 1 is laminated in the order of the adhesive layer 2, the intermediate layer 3 and the airtight layer 4.

The intermediate layer is a layer having a function of bonding the hermetic layer and the adhesive layer. The composition of the intermediate layer can be selected according to the composition and thickness of the hermetic layer and the adhesive layer, the application of the multilayer film, and the like. By providing the intermediate layer, the bonding strength between the hermetic layer and the adhesive layer can be enhanced, whereby the delamination in the multilayer film can be prevented. In addition, by providing the intermediate layer, characteristics such as mechanical strength can be improved.

The intermediate layer preferably contains a thermoplastic polymer, more preferably an olefin-based polymer, depending on the types of the gas tight layer and the adhesive layer used. In particular, the intermediate layer more preferably contains an olefin-based resin or elastomer, and more preferably contains an olefin-based resin. Examples of the olefin resin include polyethylene, polypropylene, ethylene-propylene copolymer, polybutylene, polymethylpentene and the like. Examples of polyethylene include low density polyethylene (LPDE), high density polyethylene (HDPE), and linear low density polyethylene (L-LDPE). The intermediate layer may contain the above-mentioned olefin-based polymer singly or in combination of two or more.

The olefin-based polymer may be a modified olefin-based polymer obtained by combining an unsaturated carboxylic acid or an anhydride thereof by an addition reaction, a grafting reaction or the like. As such a modified olefin polymer, maleic anhydride modified olefin resin or maleic anhydride modified olefin elastomer is mentioned. Specifically, maleic anhydride modified polyethylene, maleic anhydride modified polypropylene and the like can be mentioned. The intermediate layer may contain the above modified olefin-based polymer singly or in combination of two or more.

When the airtight layer contains a polyamide, the intermediate layer preferably contains a maleic anhydride-modified olefin-based polymer as described above, because the adhesion to the polyamide is good, and the maleic anhydride-modified polyethylene Is more preferable, and it is further preferable to contain maleic anhydride modified low density polyethylene. When the adhesive layer contains an olefin-based polymer containing an epoxy group, the intermediate layer preferably contains polyethylene which is not maleic anhydride modified, and more preferably contains polyethylene which is not modified, It is further preferred to include high density polyethylene which is not maleic anhydride modified.

The melting point of the olefin-based polymer contained in the intermediate layer is preferably 50 ° C. or more, more preferably 60 ° C. or more, and / or preferably 200 ° C. or less, more preferably 180 ° C. or less. The melting point of the intermediate layer is preferably 50 ° C. or more, more preferably 60 ° C. or less, and / or preferably 200 ° C. or less, more preferably 180 ° C. or less.

The middle layer may be two or more layers. When the intermediate layer is two or more layers, the composition of each layer may be the same or different. When the number of intermediate layers is two or more, by selecting the material of each intermediate layer so as to improve the adhesion between each layer in the multilayer film, the bond between the respective layers can be further strengthened, thereby And delamination in the multilayer film can be prevented.

An example of a multilayer film provided with two intermediate layers is shown in FIG. 3 in a schematic cross-sectional view. As shown in FIG. 3, the multilayer film 1 is laminated in the order of the adhesive layer 2, the first intermediate layer 3 a, the second intermediate layer 3 b, and the airtight layer 4. The first intermediate layer 3 a is directly bonded to the adhesive layer 2, and the second intermediate layer 3 b is directly bonded to the adhesive layer 4.

If the gas-tight layer comprises a polyamide and the adhesive layer comprises an olefin-based polymer containing epoxy groups, the second interlayer directly bonded to the gas-tight layer is preferably a maleic anhydride-modified olefinic system. It may comprise a polymer, more preferably maleic anhydride modified low density polyethylene. Also, the first intermediate layer directly bonded to the adhesive layer is preferably non-maleic anhydride modified polyethylene, more preferably non-modified polyethylene, still more preferably non-maleic anhydride modified high density polyethylene Can be included.

The thickness of the entire intermediate layer can be preferably 5 to 50 μm, more preferably 5 to 30 μm.

In addition to the components described above, additives may be added to each layer of the intermediate layer. The additives include pigments, fillers, antioxidants, hydrolysis stabilizers, antiblocking agents, and the like.

(Manufacture of multilayer film)
A multilayer film can be produced by directly bonding the adhesive layer and the hermetic layer. In addition, when the multilayer film has an intermediate layer, it can be produced by directly bonding the adhesive layer and the intermediate layer, and directly bonding the intermediate layer and the hermetic layer. In that case, the adhesive layer, the airtight layer, and, if necessary, the intermediate layer may be formed as separate sheets by extrusion or the like, and may be bonded and integrated. For example, there is a method in which the respective sheets are stacked and melt-pressed by a heat press or a heat roll, and an extrusion laminating method in which the molten material is extruded on a formed sheet.

In addition, the materials for the adhesive layer, the airtight layer, and the intermediate layer as needed may be brought into a molten state and simultaneously extruded (co-extrusion) and molded using an inflation method, a T-die method or the like. Among these, it is preferable to use an inflation method which can be enlarged and has excellent productivity.

The multilayer film produced can be cut into the desired shape and size depending on the application. The multilayer film may be wound around a reel or the like, and may be unwound at the time of use. Furthermore, in the multilayer film, a release sheet may be provided at least on the adhesive layer side, whereby the adhesive layer can be protected until immediately before use.

(Base cloth)
The multilayer film according to the present embodiment can be used by adhering to a base fabric. In the present specification, the base fabric is a sheet-like structure that functions as a support for securing the mechanical strength of the laminate obtained by laminating the multilayer film and the base fabric. Here, the sheet shape includes, in addition to a planar shape, a shape formed in a tubular shape, a bag shape, or a balloon shape when viewed as a whole.

The base fabric preferably contains fibers. The base fabric may be a woven fabric, a knitted fabric, a non-woven fabric, and may be fully or partially sewn. Among them, a woven fabric is preferable because of high mechanical strength, and a biaxial structure in which a plurality of warps and a plurality of wefts are combined is preferable, and a plurality of warps, a plurality of wefts, and a plurality of diagonals are combined. A three-axis structure can also be used. When it is a base fabric of a biaxial structure, the weave is not limited, and may be plain weave, twill weave, satin weave, and the like. The base fabric is more preferably a plain weave fabric because of its strength and ease of manufacture. In addition, the base cloth is not a flat base cloth, but OPW (One Piece Woven) woven into a cylindrical or bag shape without a seam so that it can have a curved surface according to the shape of the target product Is also included.

The above-mentioned OPW can be used in a state of being inflated and storing air therein, and can be suitably used in applications such as vehicle air bags. Among these, the OPW used for a curtain airbag has a complex curved surface in which a plurality of rooms are formed, and can have a structure having unevenness when inflated. In general, when a film is adhered to a base fabric having such an uneven structure, peeling is more likely to occur between the base fabric and the film than when the film is adhered to an uneven base fabric. However, by using the multilayer film according to the present embodiment, the multilayer film can be adhered well even if it is an OPW having irregularities, and the delamination can be prevented.

The fibers contained in the base fabric may be synthetic fibers, natural fibers, regenerated fibers, semi-synthetic fibers, inorganic fibers, and combinations thereof (including blended yarns and mixed weaves). Among them, synthetic fibers, particularly polymer fibers, are preferred. As the fibers, composite fibers such as core-sheath fibers, side-by-side fibers, and split-type fibers can also be used.

As a polymer constituting the fiber, homopolyester such as polyalkylene terephthalate such as polyethylene terephthalate and polybutylene terephthalate, aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid as an acid component constituting the repeating unit of polyester Polyester fiber copolymerized with acid, etc., nylon 6, 6 nylon 6, nylon 12, nylon 4 6 and nylon 6 and nylon 6 6 copolymer, nylon with polyalkylene glycol, dicarboxylic acid, amines etc. Sulfur such as aramid fiber represented by polymerized polyamide fiber, copolymerization with paraphenylene terephthalamide and aromatic ether, rayon fiber, ultra high molecular weight polyethylene fiber, paraphenylene sulfone, polysulfone and the like Down fibers, polyether ketone fibers and the like.

The base fabric may contain two or more fibers. For example, if the backing is a fabric, different types of fibers can be used as the fibers used for yarns extending in different directions. More specifically, in the case of having a biaxial structure including a warp and a weft, the warp and the weft can be fibers of different types. In this case, at least one of the warp yarn and the weft yarn can be made of polyester fiber.

In the present form, the backing can comprise polyester. By the base fabric containing polyester and the above-mentioned multilayer film, it is possible to obtain a laminate which is more excellent in durability under high temperature and / or high humidity environment. More specifically, the base fabric can include fibers made of polyester or fibers containing polyester. That is, the base fabric may contain polyester fibers mixed with other fibers by mixing, etc., or may contain a blended fiber of polyester and a material other than polyester, or polyester and polyester The core-sheath type, the side-by-side type, and the split type composite fibers made of other materials may be included. When the base fabric contains polyester, the laminate can be manufactured relatively inexpensively while securing the mechanical strength and the weather resistance of the laminate. In addition, when the base fabric is made of polyester fibers, the above-mentioned effect is further exhibited.

As polyester contained in a base fabric, polyalkylene terephthalate or polyalkylene naphthalate is preferable. Specific examples of the polyester include homopolyesters such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and polyesters Examples of the acid component constituting the unit include copolymers obtained by copolymerizing aliphatic dicarboxylic acids such as isophthalic acid, 5-sodium sulfoisophthalic acid and adipic acid. The above polyesters can be used alone or in combination of two or more in the form of mixed weave, blend, composite fiber, or polymer blend.

Fibers other than polyester fibers that may be included in the base fabric may be one or more of synthetic fibers made of materials other than polyester, natural fibers, regenerated fibers, semi-synthetic fibers, and inorganic fibers. Further, as materials other than polyester, polyamide, polyolefin, aramid, acrylic, vinylon, polyurethane and the like can be mentioned.

When the backing is a textile, the backing may comprise two or more different fibers, in which case, for example, the fibers or yarns extending in different directions can be of different types. For example, if it has a biaxial structure including a warp and a weft, the warp and the weft can be different types of fibers. In this case, at least one of the warp yarn and the weft yarn can be made of polyester fiber.

The yarn contained in the backing may be monofilament or multifilament. When the yarn is a multifilament, it is preferable that the total fineness of the yarn (single yarn fineness × multiple yarn number) is 100 to 700 dtex. The single yarn fineness of the fibers used in the base fabric is preferably 1 to 10 dtex. When the base fabric is a plain weave fabric, the weave density is preferably 5 to 30 yarns / cm ² for each of the warp yarns and weft yarns.

Weight per unit area of the base fabric (1 m ² per mass), taking into account the storage and cost of the laminate (final product), 300 g / ^{m 2} or less, more preferably 200 g / ^{m 2} or less, more preferably 190 g / ^{m 2} Hereinafter, more preferably, it can be 150 g / m ² or less and 100 g / m ² or less. Further, from the viewpoint of securing mechanical strength, it is preferably 30 g / m ² or more, more preferably 50 g / m ² or more, and still more preferably 70 g / m ² or more.

The base fabric may be closed, or may have an opening because the resulting laminate can be made lighter. In this embodiment, instead of forming a layer by coating the base fabric with the polymer composition, a multilayer film formed in advance is laminated on the base fabric to form a laminate. Therefore, even if a base fabric having an opening is used as a base fabric to be adhered to the multilayer film of the present embodiment, sufficient mechanical properties are prevented without causing disadvantages such as penetration of a polymer composition having a relatively low viscosity. A laminate having strength and air tightness can be obtained.

(Laminate)
FIG. 4 shows a schematic cross-sectional view of a laminate according to an embodiment of the present invention. The laminate 10 is configured by bonding the multilayer film 1 provided with the above-mentioned airtight layer 4 and the adhesive layer 2 and the base fabric 8.

In the example of FIG. 4, the multilayer film 1 is disposed on one surface of the base fabric 8, but the multilayer film of the present embodiment can also be provided on both sides of the base fabric 8. When OPW is used as the base fabric 8, as shown in FIG. 5, the multilayer films 1A and 1B are respectively from above and below on the surface of the OPW 9 (base fabric 8) in a state where the air of the bag is extracted and folded. It may be laminated. The laminate of the form shown in FIG. 5 can be used as an air bag or the like because it can store air inside.

Also, in the examples of FIGS. 4 and 5, the multilayer films 1, 1A, 1B do not have an intermediate layer, but the multilayer film of each example may have one or more of the above-mentioned intermediate layers. .

In the manufacture of laminates, cost reduction of products is always required. Particularly in the field of vehicle airbags, conventionally, polyamides such as nylon have often been used as the material of the base cloth, but in recent years relatively cheap polyester base cloth has come to be used . Therefore, a film material having high adhesiveness to a base fabric containing polyester yarn has been required. However, conventional films may not have sufficient adhesion to the base fabric containing polyester yarn. On the other hand, when the above-mentioned multilayer film provided with an adhesive layer containing an olefin-based polymer containing an epoxy group is adhered to a base cloth containing polyester to produce a laminate, conditions of high temperature and / or high humidity In the conditions of 3, it is difficult to cause delamination between the multilayer film and the base fabric, and show excellent durability.

The laminate can be adhered to the backing by heating and / or pressing the above-mentioned multilayer film. At that time, it is considered that the epoxy group contained in the olefin-based polymer in the adhesive layer irreversibly reacts with the polyester in the base fabric to form a bond. Such bonding can improve the durability of the laminate under high temperature and / or high humidity.

(Method of manufacturing laminate)
One embodiment of the present invention is a method for producing a laminate having the above-described multilayer film and a base fabric, and by pressing the multilayer film and the base fabric while heating at a temperature at which the hermetic layer does not melt, Bonding the multilayer film to the base fabric.

Here, in the laminate according to the present embodiment, the "film" means a flexible thin film, and the state of temperature, hardness and the like does not matter. That is, the multilayer film to be supplied may be at normal temperature or lower, or may have a temperature higher than normal temperature. In addition, it may be softened to be able to at least partially exhibit an adhesive function. Therefore, the laminate according to the present embodiment can be manufactured, for example, by bonding a multilayer film supplied at normal temperature or less to a base fabric while heating it at a temperature below the melting point of the hermetic layer using a heating means. Also, for example, it can be produced by bonding a polymer, which is heated by an extruder and extruded into a film, to a base cloth.

FIG. 6 schematically shows a laminate manufacturing apparatus 100 for carrying out the method of manufacturing a laminate according to the present embodiment. In FIG. 6, the apparatus for manufacturing the laminated body by which the multilayer film was laminated | stacked on both surfaces of the base fabric 8 is demonstrated. The layered product manufacturing apparatus 100 includes a heating unit 102 and a cooling unit 104.

In the manufacturing method using the laminate manufacturing apparatus 100 of FIG. 6, first, the base fabric 8 and the multilayer films 1A and 1B previously wound up in a reel or the like are respectively unwound, and both sides of the base fabric 8 (upper surface And the lower surface) of the multilayer films 1A and 1B, respectively. The multilayer film 1A, the base fabric 8 and the multilayer film 1B, which are superimposed, are sent to the heating unit 102, and pressure is applied while heating in the heating unit 102.

The heating unit 102 includes, for example, a pressing unit including a pair of opposing rolls (such as nip rolls) or a pair of opposing belts as in the example of FIG. By heating at least one of the pair of rolls or belts of such pressing means and passing the laminated multilayer film 1A, the base cloth 8 and the multilayer film 1B between the pressing means, heating and It can be pressurized. Here, since the melting point of the adhesive layer of the multilayer film is lower than the melting point of the hermetic layer, for example, the heating temperature is set to a temperature at which the adhesive layer softens or melts and the hermetic layer does not melt (melt). The adhesive layer can be pressed against the base fabric in a state where the adhesive layer is sufficiently softened or melted while securing the function of the hermetic layer. Then, the softened or melted adhesive layer can also penetrate into the concavities and convexities of the surface of the base fabric, so that the adhesive layer can be tightly adhered to the base fabric. Thereby, in the form of illustration, multilayer film 1A, 1B can be each adhere | attached on the base fabric 8, and the laminated body 10 provided with the multilayer film 1A, the base fabric 8, and the multilayer film 1B is formed and conveyed. . The heating temperature can be set, for example, to a temperature lower than the melting point of the hermetic layer, whereby the function of the hermetic layer can be ensured more reliably. Further, the heating temperature may be a temperature at which the hermetic layer does not lose its hermetic function under the influence of heat.

The stacked body 10 that has passed through the heating unit 102 is transported to the cooling unit 104. In the cooling unit 104, the temperature of the laminate 10 can be lowered preferably to room temperature. That is, the method for manufacturing a laminate according to the present embodiment may further include a cooling step. The cooling unit 104 may include a cooling unit including a cooling medium, an intake unit, and the like. Further, as in the example of FIG. 6, the cooling unit 104 may be pressurized using a pressing unit including a pair of opposing belts, but the pressing is not necessarily required. The laminate 10 is wound on a reel as needed, as shown in FIG.

In addition, in the laminated body manufacturing apparatus 100 of FIG. 6, either of the multilayer films 1A and 1B can be abbreviate | omitted. In that case, as shown in FIG. 4, the laminated body 10 by which the multilayer film 1 was laminated | stacked on the single side | surface of the base fabric 8 can be manufactured.

Further, as the base fabric 8, it is also possible to use a tubular or bag-like OPW 9 woven without a seam. Thereby, a laminate as shown in FIG. 5 can be manufactured. In the apparatus shown in FIG. 6, in the case where the base fabric 8 is OPW, air is removed from the inside of the OPW to flatten it, and the one previously wound on a reel or the like is used. Similar to the above-described example, the OPW is unwound before being superimposed, and the multilayer films 1A and 1B are respectively superimposed on the upper surface and the lower surface.

FIG. 7 schematically shows a state in which the multilayer films 1A and 1B are respectively superimposed on the upper surface and the lower surface of the OPW 9 (base fabric 8) loaded into the laminate manufacturing apparatus 100 in a flat state. . As shown in FIG. 7, the multilayer film 1A, the OPW 9 (base fabric 8), and the multilayer film 1B stacked together are pressed from both sides by a pair of pressing means in the pressing unit 102. Thereby, multilayer films 1A and 1B are bonded to the upper and lower surfaces of OPW 9 (base fabric 8), respectively, and the edges of multilayer films 1A and 1B are bonded to each other by heating and pressing or by an adhesive or the like. Thus, a laminate 10 as shown in FIG. 5 can be obtained. At this time, the adhesive layers 2A and 2B can be adhered so as to cover the entire edge of the OPW 9 (base fabric 8). Also, the extra edge of the laminate 10 can be removed by cutting or the like. In this manner, it is possible to manufacture a laminate in which the base fabric is formed in a bag shape, and the multilayer film is formed on the entire surface of the OPW 9 (base fabric 8). The laminate thus obtained can be used as an air bag.

The heating temperature at the time of manufacturing a laminated body will not be specifically limited if it is the temperature which an airtight layer does not melt | dissolve, and the temperature which an adhesive layer softens or melts. The heating temperature may be a temperature below the melting point of the hermetic layer and a temperature at which the adhesive layer softens. Although the heating temperature and pressure depend on the configuration of the multilayer film and the base fabric, the heating temperature is preferably 100 ° C. or more, more preferably 120 ° C. or more, and / or 250 ° C. or less C. or less, more preferably 200.degree. C. or less. Moreover, the pressurizing pressure is preferable to be 5N / cm ² or more, it can be 10 N / cm ² or more, and / or preferable to be 700 N / cm ² or less, to 500 N / cm ² or less Can. Furthermore, it can be 5 to 50 N / cm ² according to the operating conditions at the time of manufacturing the laminate.

(Use)
The multilayer film and the laminate according to the present embodiment are suitably used in vehicle airbags, outdoor products, packaging applications and the like, and particularly suitably used in the manufacture of vehicle airbags, particularly curtain airbags. The curtain airbag is attached to a roof line or the like in the upper portion of the side window, and refers to an airbag that is deployed in a curtain shape vertically downward along the side window when a high load is applied in a collision or the like.

Since the curtain airbag needs to be maintained in a state of being inflated for several seconds, for example, 6 to 7 seconds after its operation, the material of the curtain airbag is required to have pressure resistance, specifically, Mechanical strength such as strength and tear strength is required. In addition, since the curtain airbag is often stored in a casing or the like in a folded or rolled state for a long time before deployment, flexibility is also required. In addition, when stored, it is often exposed to high temperature and high humidity environments. However, the multilayer film and the laminate according to the present embodiment can be suitably used even in such applications.

In addition, when the laminated body which has a film and base cloth is used as an airbag of a vehicle, the various performance which considered safety | security is requested | required. The standards for safety are set in each country, but the standards tend to be strict. For example, in the United States in recent years, safety standards for air bags have been raised, and in terms of durability under high temperature and high humidity conditions, for example, temperature and humidity conditions in the conventional high temperature and high humidity adhesion test are temperature What was 40.degree. C. and 92% relative humidity becomes more severe as 70.degree. C. temperature and 95% relative humidity. Therefore, there has been a demand for an air bag material that can withstand such severe high temperature and high humidity environment. On the other hand, the multilayer film and the laminate according to the present embodiment are unlikely to cause delamination even after being stored under such severe high temperature and high humidity, and can exhibit excellent durability.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

In this example, a multilayer film was formed, and the multilayer film was further adhered to a base fabric to produce a laminate, which was evaluated.

[Evaluation]
<High temperature and high humidity adhesion (durability under high temperature and high humidity)>
From the laminate obtained by laminating the multilayer film and the base fabric, a test piece of 50 × 150 mm is prepared, and this test piece is placed in a closed container, and the conditions in the container are 70 ° C., 95% relative humidity. And kept for 168 hours. Thereafter, while fixing the portion of the base fabric of the test piece (laminate) taken out of the container, the force required when peeling off the portion of the multilayer film in the direction of 180 ° at a tensile speed of 100 mm / min It measured as N / mm). Evaluation criteria are as follows.
Good: Peeling force was over 0.5 N / mm.
Δ: Peeling force was 0.3 to 0.5 N / mm.
X: Peeling force was less than 0.3 N / mm, or delamination occurred in the multilayer film.

In the peeling force measurement, in order to prevent the multilayer film from being broken or stretched during the peeling test, a 100 μm-thick polyethylene terephthalate film is attached to the airtight layer side of the multilayer film through an adhesive. It reinforced and used.

Example 1
(Preparation of multilayer film)
In an inflation extrusion apparatus (manufactured by Collin) having four extruders, terpolymers of ethylene, acrylic ester, and glycidyl methacrylate (“LOTADER® AX 8900” manufactured by Arkema, content of glycidyl methacrylate: 8% by mass, Melting point: 65 ° C), high density polyethylene ("HMA014" manufactured by Exxonmobile, melting point: 134 ° C), and low density polyethylene modified with maleic anhydride ("Plexar PX800" manufactured by Lyondell Basell, melting point 117 ° C to 125 ° C) A polyamide (“Vestamid (registered trademark)” manufactured by Evonik, melting point 170 ° C.) was frequently added, and melted at a temperature higher than the melting point of each resin to prepare a four-layer film by an inflation method. The extrusion rate of each layer was 10 g / m ² .

The obtained four-layer film is a terpolymer of ethylene, acrylic ester and glycidyl methacrylate as an adhesive layer, high density polyethylene as a first intermediate layer, low density polyethylene modified with maleic anhydride as a second intermediate layer, and polyamide as an airtight layer. Were stacked in the order described.

(Lamination of base cloth and multilayer film)
Using a laminating device (Twin-belt flat lamination system manufactured by Mayer), with an adhesive layer made of polyethylene terephthalate (PET) base fabric and the above-mentioned four-layer film in contact with the base fabric surface, 18 N with a nip roll heated to 170 ° C. The above adhesive layer was softened while being pressurized to ² cm ² to laminate the base cloth and the four-layer film. As a base fabric made of PET, a plain weave base fabric with a weave density of 22 / cm was used, with warps and wefts having a total fineness of 470 dtex.

When the high temperature and high humidity adhesion was measured as described above, the peeling force was 0.52 N / mm. Therefore, it turned out that the layered product of Example 1 shows the outstanding high temperature high humidity adhesiveness.

Hereinafter, preferred embodiments of the present invention will be additionally stated.
(Supplementary Note 1)
A multilayer film used by bonding to a base fabric containing polyester,
An adhesive layer on the side to be adhered to the backing, and an airtight layer bonded to the adhesive layer,
The adhesive layer comprises an olefin-based polymer containing an epoxy group,
The multilayer film, wherein the melting point of the hermetic layer is higher than the melting point of the adhesive layer.
(Supplementary Note 2)
The multilayer film according to claim 1, wherein the content of epoxy group of the olefin-based polymer is 0.05 to 5% by mass with respect to the total amount of the olefin-based polymer.
(Supplementary Note 3)
The multilayer film according to claim 1, wherein the olefin-based polymer is a terpolymer including ethylene, (meth) acrylic ester, and glycidyl (meth) acrylate.
(Supplementary Note 4)
5. The multilayer film of any of Appendices 1 to 3, wherein the hermetic layer comprises a polymer having a melting point of 160 ° C. or higher.
(Supplementary Note 5)
Additional layer according to any of the preceding claims, wherein the hermetic layer comprises a polyamide.
(Supplementary Note 6)
5. The multilayer film according to appendix 5, wherein the multilayer film has an intermediate layer between the adhesive layer and the airtight layer.
(Appendix 7)
Supplementary note 6, wherein the melting point of the intermediate layer is higher than the melting point of the adhesive layer and lower than the melting point of the hermetic layer.
(Supplementary Note 8)
The intermediate layer has a first intermediate layer and a second intermediate layer, the first intermediate layer is bonded to the adhesive layer, and the second intermediate layer is bonded to the air tight layer.
The multilayer film according to Appendix 6 or 7, wherein the first intermediate layer comprises polyethylene which is not maleic anhydride modified, and the second intermediate layer comprises maleic anhydride modified polyethylene.
(Appendix 9)
A laminate, wherein the multilayer film according to any one of appendices 1 to 8 and a base fabric containing polyester are adhered.
(Supplementary Note 10)
A method for producing a laminate comprising a base fabric and a multilayer film,
The base fabric comprises polyester and
The multilayer film is a multilayer film having an adhesive layer containing an olefin-based polymer containing an epoxy group, and an airtight layer bonded to the adhesive layer, having a melting point higher than that of the adhesive layer, and containing a polymer. Yes,
A method for producing a laminate, comprising the step of adhering the multilayer film and the base fabric by pressing the multilayer film and the base fabric while heating at a temperature at which the hermetic layer does not melt.
(Supplementary Note 11)
The method according to claim 10, wherein the heating temperature is 130 to 200 ° C.
(Supplementary Note 12)
The manufacturing method according to appendix 10 or 11, wherein the applied pressure is 10 to 30 N / cm ² .
(Supplementary Note 13)
15. The manufacturing method according to any one of appendices 10 to 12, further comprising the step of cooling the laminate to a temperature not higher than the melting point of the adhesive layer.
(Supplementary Note 14)
An airbag comprising the multilayer film according to any one of appendices 1 to 8.

This application claims the priority based on Japanese Patent Application No. 2017-161160 filed on Aug. 24, 2017 to the Japanese Patent Office, the entire contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Multilayer film 2, 2A, 2B Adhesive layer 3 Intermediate layer 3a 1st intermediate layer 3b 2nd intermediate layer 4, 4A, 4B Air tight layer 8 Base cloth 9 OPW
DESCRIPTION OF SYMBOLS 10 Laminated body 100 Laminated body manufacturing apparatus 102 Heating part 104 Cooling part

Claims (13)

1. A multilayer film used by bonding to a base cloth,
   An adhesive layer on the side to be adhered to the backing, and an airtight layer bonded to the adhesive layer,
   The adhesive layer comprises an olefin-based polymer containing an epoxy group,
   The multilayer film, wherein the melting point of the hermetic layer is higher than the melting point of the adhesive layer.
2. The multilayer film according to claim 1, wherein the content of the epoxy group of the olefin-based polymer is 0.05% by mass or more and 5% by mass or less with respect to the total amount of the olefin-based polymer.
3. The multilayer film according to claim 1, wherein the olefin-based polymer is a terpolymer including ethylene, (meth) acrylic ester, and glycidyl (meth) acrylate.
4. The multilayer film according to any one of claims 1 to 3, wherein the hermetic layer comprises a polymer having a melting point of 160 ° C or higher.
5. The multilayer film according to any one of claims 1 to 4, wherein the hermetic layer comprises a polyamide.
6. The multilayer film according to claim 5, wherein the multilayer film has an intermediate layer between the adhesive layer and the airtight layer.
7. The multilayer film according to claim 6, wherein the melting point of the intermediate layer is higher than the melting point of the adhesive layer and lower than the melting point of the hermetic layer.
8. The intermediate layer has a first intermediate layer and a second intermediate layer, the first intermediate layer is bonded to the adhesive layer, and the second intermediate layer is bonded to the air tight layer.
   The multilayer film according to claim 6 or 7, wherein the first intermediate layer comprises polyethylene not modified with maleic anhydride, and the second intermediate layer comprises polyethylene modified with maleic anhydride.
9. A laminated body in which the multilayer film according to any one of claims 1 to 8 and a base fabric containing polyester are adhered.
10. A method for producing a laminate comprising a base fabric and a multilayer film,
    The multilayer film is a multilayer film having an adhesive layer containing an olefin-based polymer containing an epoxy group, and an airtight layer bonded to the adhesive layer, having a melting point higher than that of the adhesive layer, and containing a polymer. Yes,
    A method for producing a laminate, comprising the step of adhering the multilayer film and the base fabric by pressing the multilayer film and the base fabric while heating at a temperature at which the hermetic layer does not melt.
11. The method according to claim 10, wherein the heating temperature is 130 ° C. or more and 200 ° C. or less.
12. The manufacturing method according to any one of claims 10 or 11, further comprising the step of cooling the laminated body to a temperature equal to or lower than the melting point of the adhesive layer.
13. An airbag comprising the multilayer film according to any one of claims 1 to 8.

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