JP2014117827A - Method of producing air permeation preventive layer for pneumatic tire and tire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air permeation preventive layer film composed of a thermoplastic elastomer composition and having improved dimensional stability and durability.SOLUTION: A method of producing an air permeation preventive layer film composed of a thermoplastic elastomer composition in which a rubber is dispersed in a thermoplastic resin includes (1) a step of melting the thermoplastic elastomer composition, (2) a step of discharging the thermoplastic elastomer composition from a die to form a film of the thermoplastic elastomer, (3) a step of heat-treating the film of the thermoplastic elastomer composition to relax molecular orientation and immobilizing the molecules and (4) a step of cooling the film of the thermoplastic elastomer composition.

Description

  The present invention relates to a method for producing an air permeation prevention layer film. More specifically, the present invention relates to a method for producing an air permeation preventive layer film made of a thermoplastic elastomer composition, an air permeation preventive layer film produced by the method, and a pneumatic tire using the air permeation preventive layer film.

  A film made of a thermoplastic elastomer composition in which rubber is dispersed in a continuous phase of a thermoplastic resin is known (see, for example, Patent Document 1). Due to its light weight and air permeation resistance, air permeation prevention of pneumatic tires is known. Used for layers.

  An air permeation preventive layer film made of such a thermoplastic elastomer composition is usually produced by being stretched during film formation (see, for example, Patent Document 2).

JP-A-8-217923 JP 2006-315339 A

  A film made of a thermoplastic elastomer composition tends to shrink when stretched due to its rubber component, and has low dimensional stability. Further, the orientation of the polymer molecular chain of the thermoplastic resin by stretching makes it easy to tear the film in a specific direction, resulting in a decrease in durability.

  Accordingly, an object of the present invention is to provide a method for producing an air permeation preventive layer film comprising a thermoplastic elastomer composition having improved dimensional stability and durability, an air permeation preventive layer film produced by the method, and the air. It is to provide a pneumatic tire using a permeation preventive layer film.

  As a result of intensive studies, the present inventors heat-treated the film after forming an air permeation preventive layer film made of the thermoplastic elastomer composition to relax the molecular orientation of the thermoplastic resin, and the heat of which orientation was relaxed. The inventors have found that the dimensional stability and durability of the film can be improved by immobilizing the molecules of the plastic resin, and the present invention has been achieved.

That is, the present invention includes the following aspects [1] to [9].
[1] A method for producing an air permeation preventive layer film comprising a thermoplastic elastomer composition in which rubber is dispersed in a thermoplastic resin,
(1) a step of melting the thermoplastic elastomer composition;
(2) a step of forming a film of the thermoplastic elastomer composition by discharging the thermoplastic elastomer composition from a die;
(3) The method comprising the steps of heat treating a film of the thermoplastic elastomer composition to relax molecular orientation and immobilizing the molecules, and (4) cooling the film of the thermoplastic elastomer composition.

  [2] The thermoplastic resin is nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 69, nylon 610, nylon 612, nylon 6/66, nylon 6/66/12, nylon 6/66 / 610, nylon MXD6, nylon 6T, nylon 6 / 6T, nylon 9T, and the method for producing an air permeation preventive layer film according to the above [1], which is at least one selected from the group consisting of aromatic nylon.

  [3] The above [1] or [2], wherein the rubber is at least one selected from the group consisting of a brominated isobutylene-paramethylstyrene copolymer and a maleic anhydride-modified ethylene-α-olefin copolymer. Manufacturing method of air permeation prevention layer film.

  [4] In the step of melting the thermoplastic elastomer composition, the air permeation according to any one of the above [1] to [3], wherein an extruder having a single screw or two or more screws is used. A method for producing a protective layer film.

  [5] The above-mentioned [1], wherein the step of forming the thermoplastic elastomer composition film by discharging the thermoplastic elastomer composition from the die is a film forming step using an inflation die or a T-shaped die. The method for producing an air permeation preventive layer film according to any one of [4].

[6] The step of heat-treating the film of the thermoplastic elastomer composition to relax the molecular orientation and immobilizing the molecules fixes the film and has the highest glass transition temperature contained in the thermoplastic elastomer composition. The air permeation prevention according to any one of the above [1] to [5], wherein the thermoplastic resin is a step of performing a heat treatment at a temperature from _Tm- 100 ° C to _Tm + 50 ° C, with a melting point of _Tm ° C. A method for producing a layer film.

  [7] The step of cooling the film of the thermoplastic elastomer composition reduces the film temperature of the thermoplastic elastomer composition to less than the glass transition temperature of the thermoplastic resin having the highest glass transition temperature contained in the thermoplastic elastomer composition. The method for producing an air permeation preventive layer film according to any one of the above [1] to [6], which is a step of lowering.

  [8] An air permeation preventive layer film produced by the method according to any one of [1] to [7].

  [9] A pneumatic tire using the air permeation preventive layer film according to [8].

  According to the method of the present invention, an air permeation preventive layer film comprising a thermoplastic elastomer composition having excellent dimensional stability and durability can be produced.

FIG. 1 is a schematic view of one example of the production method of the present invention using an inflation die in a film forming process. FIG. 2 is a schematic view of one example of the production method of the present invention using a T-shaped die in the film forming step. FIG. 3 is a schematic diagram of one example of a process of heat treating a film of a thermoplastic elastomer composition to relax molecular orientation and immobilize molecules.

The method for producing an air permeation preventive layer film comprising the thermoplastic elastomer composition of the present invention includes the following steps:
A step of melting the thermoplastic elastomer composition (hereinafter referred to as step (1));
A step of forming a film by discharging the thermoplastic elastomer composition from a die (hereinafter referred to as step (2));
Heat treating the film of the thermoplastic elastomer composition to relax the molecular orientation and immobilize the molecules (hereinafter referred to as step (3)); and
A step of cooling the film of the thermoplastic elastomer composition (hereinafter referred to as step (4)).

  In this specification, the thermoplastic elastomer composition is a composition in which a rubber component is dispersed in a thermoplastic resin component, the thermoplastic resin component constituting a continuous phase, and the rubber component constituting a dispersed phase. Is.

  The thermoplastic resin that can be used in the present invention is not particularly limited, and can be appropriately selected depending on the use of the thermoplastic elastomer composition. Examples of the thermoplastic resin include polyamide resin, polyester resin, polynitrile resin, polymethacrylate resin, polyvinyl resin, cellulose resin, fluorine resin, imide resin, polystyrene resin, polyolefin resin, and the like. Polyamide resins include nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon 6 / 66 (N6 / 66), nylon 6/66/12 (N6 / 66/12), nylon 6/66/610 (N6 / 66/610), nylon MXD6 (MXD6), nylon 6T, nylon 6 / 6T, nylon 9T, aromatic nylon, nylon 66 / PP copolymer, nylon 66 / PPS copolymer, and the like. Polyester resins include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), PET / PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, poly Examples thereof include aromatic polyesters such as oxyalkylene diimidic acid / polybutyrate terephthalate copolymer. Examples of the polynitrile resin include polyacrylonitrile (PAN), polymethacrylonitrile, acrylonitrile / styrene copolymer (AS), methacrylonitrile / styrene copolymer, methacrylonitrile / styrene / butadiene copolymer, and the like. Examples of the polymethacrylate resin include polymethyl methacrylate (PMMA) and polyethyl methacrylate. Examples of the polyvinyl resin include polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), ethylene-vinyl acetate copolymer (EVA), polyvinylidene chloride (PVDC), and polyvinyl chloride. (PVC), vinyl chloride / vinylidene chloride copolymer, vinylidene chloride / methyl acrylate copolymer, and the like. Examples of the cellulose resin include cellulose acetate and cellulose acetate butyrate. Examples of the fluororesin include polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), and tetrafluoroethylene / ethylene copolymer (ETFE). Examples of the imide resin include aromatic polyimide (PI). Examples of the polystyrene resin include polystyrene (PS). Examples of the polyolefin resin include polyethylene (PE) and polypropylene (PP).

  Among the thermoplastic resins, nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 69, nylon 610, nylon 612, nylon 6/66, nylon 6/66/12, nylon 6/66/610 , Nylon MXD6, Nylon 6T, Nylon 6 / 6T, Nylon 9T, and at least one selected from the group consisting of aromatic nylon are preferable in terms of air barrier properties.

  The thermoplastic resin used in the present invention includes a filler, a reinforcing agent, a processing aid, a stabilizer, an antioxidant, etc. for improving processability, dispersibility, heat resistance, antioxidant property, and the like. You may mix | blend the compounding agent generally mix | blended with a thermoplastic resin composition in the range which does not inhibit the effect of this invention. The plasticizer should not be blended from the viewpoints of gas barrier properties and heat resistance, but may be blended as long as the effects of the present invention are not impaired.

  The rubber that can be used in the present invention is not particularly limited, and can be appropriately selected depending on the use of the thermoplastic elastomer composition. Examples of the rubber include diene rubber and hydrogenated products thereof, olefin rubber, halogen-containing rubber, silicone rubber, sulfur-containing rubber, and fluorine rubber. Diene rubbers and hydrogenated products thereof include natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber (ENR), styrene butadiene rubber (SBR), butadiene rubber (BR) (high cis BR and low cis BR), acrylonitrile butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR, and the like. Examples of the olefin rubber include ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), maleic acid-modified ethylene propylene rubber (M-EPM), ethylene-α-olefin copolymer and modified products thereof such as maleic anhydride. Modified ethylene-α-olefin copolymer, ethylene-glycidyl methacrylate copolymer and modified product thereof, ethylene-ethyl acrylate copolymer and modified product thereof such as maleic anhydride modified ethylene-ethyl acrylate copolymer, butyl rubber (IIR) ), Isobutylene and aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), ionomer and the like. Examples of the halogen-containing rubber include halogenated butyl rubber such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR), brominated isobutylene-paramethylstyrene copolymer (BIMS) and modified products thereof, and halogenated isobutylene. -Isoprene copolymer rubber, chloroprene rubber (CR), hydrin rubber (CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid-modified chlorinated polyethylene (M-CM) and the like. Examples of the silicone rubber include methyl vinyl silicone rubber, dimethyl silicone rubber, and methyl phenyl vinyl silicone rubber. Examples of the sulfur-containing rubber include polysulfide rubber. Examples of the fluorine rubber include vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicone rubber, and fluorine-containing phosphazene rubber.

  Among the above rubbers, at least one selected from the group consisting of a brominated isobutylene-paramethylstyrene copolymer and a maleic anhydride-modified ethylene-α olefin copolymer is preferable from the viewpoint of durability or processability.

  In the rubber used in the present invention, a compounding agent generally blended in a rubber composition, such as a reinforcing agent (filler) such as carbon black or silica, a softening agent, an anti-aging agent and a processing aid, is included in the present invention. You may mix | blend in the range which does not inhibit this effect.

  In order to produce the thermoplastic elastomer composition, the thermoplastic resin component and the rubber component may be melt-kneaded with a kneading extruder or the like, and the rubber component may be dispersed in the thermoplastic resin forming the continuous layer.

  In order to fix the dispersed state of the rubber, the rubber may be dynamically crosslinked during kneading. In the present specification, dynamic crosslinking refers to crosslinking at the same time as melt-kneading.

  The crosslinking agent is not particularly limited, and can be appropriately selected according to the rubber composition. Zinc oxide, stearic acid, zinc stearate, magnesium oxide, m-phenylene bismaleimide, alkylphenol resin and its halides, secondary amines (eg N- (1,3-dimethylbutyl) -N′-phenyl-p- And phenylenediamine (6PPD) and polymerized 2,2,4-trimethyl-1,2-dihydroquinoline). Of these, zinc oxide, stearic acid, and N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine are preferable.

  The amount of the crosslinking agent is preferably 0.1 to 12 parts by weight, and more preferably 1 to 9 parts by weight with respect to 100 parts by weight of rubber.

  The kneader used for kneading the thermoplastic resin and rubber is not particularly limited, and examples thereof include a Banbury mixer and an extruder having a single screw or two or more screws. Preferably, an extruder having a single screw or two or more screws is used.

  As the conditions for melt kneading, the kneading temperature may be higher than the temperature at which the thermoplastic resin melts. Although it is the temperature more than melting | fusing point of a thermoplastic resin, Preferably it is 20 degreeC higher than melting | fusing point of a thermoplastic resin, for example, 200-250 degreeC. The time for the entire kneading is not particularly limited, but is usually 1 minute to 10 minutes.

  The composition ratio between the thermoplastic resin component and the rubber component in the thermoplastic elastomer composition is not particularly limited, and may be appropriately determined depending on the balance of film thickness, fatigue durability, flexibility, and the like. A preferable range is 35 to 400 parts by weight, more preferably 50 to 200 parts by weight of the thermoplastic resin with respect to 100 parts by weight of rubber.

  The produced thermoplastic elastomer composition may be extruded, for example, in a strand shape, and once pelletized with a resin pelletizer, may be subjected to step (1) of the present invention. Alternatively, the manufacturing process of the thermoplastic elastomer composition is the step (1) of the present invention, and then the thermoplastic elastomer composition is discharged in a molten state from a die attached to the discharge port of the extruder, and a thermoplastic resin is obtained. You may use for the process (2) of this invention shape | molded to the film of an elastomer composition.

  In step (1), the thermoplastic elastomer composition is melted. Melting is not particularly limited, but is performed using a Banbury mixer, an extruder having a single screw or two or more screws. Among these, an extruder having a single screw or a twin screw or more is preferable.

  The melting temperature in the step (1) may be equal to or higher than the temperature at which the thermoplastic resin melts. The temperature is preferably 20 ° C. higher than the melting point of the thermoplastic resin, for example, 200 to 250 ° C. The melting time is preferably 15 seconds to 10 minutes.

  In the step (2), the molten thermoplastic resin elastomer composition is discharged from a die attached to a discharge port of an extruder and formed into a film of the thermoplastic resin elastomer composition. Step (2) is preferably performed by stretching the thermoplastic resin elastomer composition discharged from the die. Stretching is performed by applying a stress in at least one direction to the thermoplastic resin elastomer composition.

  Although it does not specifically limit as a die | dye used in a process (2), It is preferable to film-form using an inflation die or a T-shaped die.

  In step (3), the film obtained in step (2) is subjected to heat treatment, the molecular orientation is relaxed, and the molecules are immobilized. In the present specification, the relaxation of molecular orientation means to relax the orientation of molecules of the thermoplastic resin produced by the film forming process, and the immobilization of molecules refers to the molecules of thermoplastic resin whose orientation has been relaxed. It is to fix by recrystallization. The heat treatment of this step improves the dimensional stability and durability of the film.

  The heat treatment in the step (3) is performed while maintaining the film width by fixing both ends in the width direction of the film obtained in the step (2) by fixing means such as a clip to avoid shrinkage of the film width. It is preferable from the viewpoint.

  FIG. 3 is a schematic diagram of an example of the step (3). Clips 9 running on an endless track rail are provided on both sides of the film conveyance path from the upstream side to the downstream side in the film conveyance direction. The clip 9 moves in the film transport direction in a state where both ends of the film 10 in the width direction are gripped. The film is subjected to heat treatment while maintaining the film width in a state where both ends in the width direction are held by the clip.

The heat treatment in the step (3) is preferably performed at a temperature of _Tm- 100 ° C to _Tm + 50 ° C, where T _m ° C is the melting point of the thermoplastic resin having the highest glass transition temperature contained in the thermoplastic elastomer composition. More preferably, it is carried out at a temperature of T _m −50 ° C. to T _m + 10 ° C.

  The heat treatment time is preferably 1 second to 600 seconds, more preferably 3 seconds to 180 seconds. The heat treatment time can be arbitrarily adjusted according to the speed at which the film flows through the conveyance path and the length in the film conveyance direction of the heat treatment process zone (for example, region 4 in FIG. 1 and region 8 in FIG. 2).

  In step (4), the film obtained in step (3) is cooled. The film is preferably cooled by lowering it below the glass transition temperature of the thermoplastic resin having the highest glass transition temperature contained in the thermoplastic elastomer composition. The cooling method is not particularly limited. For example, the cooling method is performed by blowing air on the film or by naturally cooling the film.

  The air permeation preventive layer film of the present invention can be used, for example, as an air permeation preventive layer in a pneumatic tire, and preferably as an inner liner in a pneumatic tire.

  A conventional method can be used as a method for producing a pneumatic tire using the air permeation preventive layer film of the present invention. For example, the air permeation preventive layer film of the present invention is attached in a cylindrical shape on a tire molding drum, and tire members such as a carcass layer, a belt layer, and a tread layer are sequentially laminated on the tire molding drum so that Remove the tire. Next, by vulcanizing the green tire according to a conventional method, a desired pneumatic tire using the air permeation preventive layer film of the present invention can be produced.

  The present invention will be further described in the following examples, but the scope of the present invention is not limited to these examples.

(1) Production of thermoplastic elastomer composition The following were used as raw materials.
Br-IPMS: Brominated isobutylene-p-methylstyrene copolymer rubber Exxpro (registered trademark) MDX89-4 manufactured by ExxonMobil Chemical Company
Maleic anhydride-modified ethylene-α olefin copolymer: maleic acid-modified ethylene-butene copolymer TUFMER (registered trademark) MH7010 manufactured by Mitsui Chemicals, Inc.
Zinc oxide: 3 types of zinc oxide manufactured by Shodo Chemical Industry Co., Ltd. N- (1,3-Dimethylbutyl) -N′-phenyl-p-phenylenediamine (6PPD): SantoFLEX 6PPD manufactured by Flexsys
Stearic acid: Beads stearic acid nylon 6/66 copolymer manufactured by NOF Corporation (melting point 195 ° C., glass transition temperature 50 ° C.): Novamid 2010R manufactured by DSM Japan Engineering Plastics Co., Ltd.
Nylon 6 (melting point 225 ° C., glass transition temperature 48 ° C.): UBE nylon 1013B manufactured by Ube Industries, Ltd.
Nylon 612 (melting point: 197 ° C., glass transition temperature: 43 ° C.): UBE nylon 7034B manufactured by Ube Industries, Ltd.

  Of the raw materials shown in Table 3 below, Br-IPMS was processed into pellets with a rubber pelletizer (manufactured by Moriyama Seisakusho) in advance. The rubber pellets, maleic anhydride-modified ethylene-α olefin copolymer, thermoplastic resin (nylon 6/66 copolymer, nylon 6, nylon 612), crosslinking agent (zinc oxide, stearic acid, 6PPD) The mixture was introduced into a twin-screw kneading extruder (manufactured by Nippon Steel Works) at a blending ratio shown in FIG. The kneaded product was continuously extruded into a strand from an extruder, cooled with water, and then cut with a cutter to obtain a pellet-shaped thermoplastic elastomer composition.

(2) Manufacture of air permeation prevention layer film The thermoplastic elastomer composition obtained in the above (1) is melted at 230 ° C. using an inflation molding apparatus (manufactured by Placo), extruded into a tube shape, and air is blown into it. And a tube-shaped air permeation preventive layer film was obtained by folding and winding with a pinch roll. The thickness of the obtained film was 130 μm, and the folded film width was 600 mm.

  In Examples 1 to 5, a heat treatment step was provided after folding with a pinch roll, and the heat treatment was performed at the temperatures shown in Table 3. As shown in FIG. 3, the heat treatment step was performed such that the film flows through the conveyance path while maintaining the film width by holding both ends in the width direction of the film with clips. The heat treatment time was the heat treatment time described in Table 3. After the heat treatment step, cooling was performed by blowing air so that the temperature of the film was equal to or lower than the glass transition temperature of the thermoplastic resin contained in the thermoplastic elastomer.

  About Comparative Examples 1-3, after folding with a pinch roll, it wound up as it was, without heat-processing.

(3) Measurement of film shrinkage Each obtained air permeation prevention layer film was cut into a belt shape having a width of 10 cm perpendicular to the extrusion direction, and the width (W1) in the longitudinal direction was immediately measured. Further, each cut out air permeation preventive layer film was left in the room for one week, and the width (W2) in the longitudinal direction was measured again. The shrinkage was determined by substituting this measured width into the following formula, and the results are shown in Table 3.

  Shrinkage rate = ((W1-W2) / W1) × 100

(4) Evaluation of film durability On the surface of each air permeation preventive layer film, the adhesive composition having the composition shown in Table 1 below was applied with a brush and dried, and then on the rubber composition having the composition shown in Table 2 below. The laminate was made of a 1 mm thick air permeation preventive layer film and a rubber composition. From this laminate, six JIS No. 3 dumbbells were punched out so that the extrusion direction of the air permeation preventive layer film was the longitudinal direction, and a 40% cyclic strain was applied at −35 ° C. with a constant strain tester (manufactured by Ueshima Seisakusho) It was over. After straining 1 million times, the dumbbell was taken out and the film surface was observed. Table 3 shows the number of cracks in the film among the six.

  The test results are shown in Table 3.

  In Comparative Examples 1 to 3, a film made of a thermoplastic elastomer composition was produced without passing through the heat treatment step (3) after the film forming step (2) of the present invention. All of them exhibited a film shrinkage rate of 1.0% or more, and cracks were observed in a plurality of samples among 6 samples in the film durability test.

  Examples 1 to 5 were carried out according to the method of the present invention. Compared with the comparative example, the shrinkage rate of the film was low, and no cracks were observed or only one sample was observed in 6 samples in the film durability test. Therefore, it was confirmed that the air permeation preventive layer film produced by the method of the present invention has excellent dimensional stability and durability.

  The air permeation preventive layer film obtained by the method of the present invention can be suitably used for pneumatic tires and the like.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Inflation die 3 Film 4 Heat treatment process zone 5 Extruder 6 T-shaped die 7 Film 8 Heat treatment process zone 9 Clip 10 Film

Claims (9)

A method for producing an air permeation preventive layer film comprising a thermoplastic elastomer composition in which rubber is dispersed in a thermoplastic resin,
(1) a step of melting the thermoplastic elastomer composition;
(2) A step of discharging a thermoplastic elastomer composition from a die to form a film of the thermoplastic elastomer composition,
(3) The method comprising the steps of heat treating a film of the thermoplastic elastomer composition to relax molecular orientation and immobilizing the molecules, and (4) cooling the film of the thermoplastic elastomer composition.   The thermoplastic resin is nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 69, nylon 610, nylon 612, nylon 6/66, nylon 6/66/12, nylon 6/66/610, nylon. The manufacturing method of the air permeation prevention layer film of Claim 1 which is at least 1 type chosen from the group which consists of MXD6, nylon 6T, nylon 6 / 6T, nylon 9T, and aromatic nylon.   The air permeation preventive layer film according to claim 1 or 2, wherein the rubber is at least one selected from the group consisting of a brominated isobutylene-paramethylstyrene copolymer and a maleic anhydride-modified ethylene-α-olefin copolymer. Manufacturing method.   The method for producing an air permeation preventive layer film according to any one of claims 1 to 3, wherein an extruder having a single screw or a twin screw or more is used in the step of melting the thermoplastic elastomer composition. .   5. The method according to claim 1, wherein the step of discharging the thermoplastic elastomer composition from a die to form a film of the thermoplastic elastomer composition is a film forming step using an inflation die or a T-shaped die. 2. A method for producing an air permeation preventive layer film according to item 1. The step of heat treating the film of the thermoplastic elastomer composition to relax the molecular orientation and immobilizing the molecules fixes the thermoplastic resin having the highest glass transition temperature contained in the thermoplastic elastomer composition. the melting point as T _m ° C., a step of performing heat treatment at a temperature of T _{m +} 50 ° C. from T _m -100 ° C., a manufacturing method of the air permeation preventive layer film according to any one of claims 1 to 5.   The step of cooling the film of the thermoplastic elastomer composition is a step of lowering the film temperature of the thermoplastic elastomer composition to less than the glass transition temperature of the thermoplastic resin having the highest glass transition temperature contained in the thermoplastic elastomer composition. The manufacturing method of the air permeation prevention layer film of Claim 1 which exists.   The air permeation prevention layer film manufactured by the method of any one of Claims 1-7.   A pneumatic tire using the air permeation preventive layer film according to claim 8.

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