Adhesive sealing film for fuel cell

Abstract

To provide an adhesive sealing film for a fuel cell using a resin composition capable of suppressing a decrease in tensile fracture stress.SOLUTION: An adhesive sealing film 10 for a fuel cell includes a base material layer 11 containing a resin as a forming material, and an adhesive layer 13 laminated on each of both surfaces of the base material layer 11 with an intermediate layer 12 interposed between the base material layer and the adhesive layer. The base material layer 11 is formed of a resin composition containing a polyester resin other than a liquid crystal polymer, a low-melting-point liquid crystal polymer having a crystal melting temperature of 250°C or lower, and an acid-modified polyethylene resin, the intermediate layer 12 is formed of an acid-modified polyethylene resin or an imine-modified polyolefin resin, and the adhesive layer 13 is formed of an acid-modified polypropylene resin.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an adhesive sealing film for fuel cells.

Background Art

[0002] Among polyester resins, liquid crystal polymers have good hydrolysis resistance. However, it is difficult to knead a liquid crystal polymer with a crystal melting temperature of 280°C or higher with other resins to form a polymer alloy. Therefore, a resin composition obtained by polymer alloying a low-melting liquid crystal polymer with a crystal melting temperature of 250°C or lower and other resins is commercially available (see, for example, Patent Documents 1 and 2). In addition, Patent Document 3 discloses a hot melt adhesive resin laminate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a resin composition in which a low-melting liquid crystal polymer with a crystal melting temperature of 250°C or lower is finely dispersed, the hydrolysis resistance of the liquid crystal polymer is affected and decreased. When stored or used under humid conditions, there is a problem that the tensile fracture stress of the resin composition decreases.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide an adhesive sealing film for fuel cells using a resin composition capable of suppressing a decrease in tensile fracture stress.

Means for Solving the Problems

[0006] The first aspect is an adhesive sealing film for a fuel cell, which has a base material layer made of a resin as a forming material, and adhesive layers laminated on both surfaces of the base material layer via intermediate layers respectively. The base material layer is formed from a resin composition containing a polyester resin other than a liquid crystal polymer, a low melting point liquid crystal polymer having a crystal melting temperature of 250°C or lower, and an acid-modified polyethylene resin. The intermediate layer is formed from an acid-modified polyethylene resin or an imine-modified polyolefin resin, and the adhesive layer is formed from an acid-modified polypropylene resin.

[0007] The second aspect is that in the first aspect, the base material layer contains an acid-modified polyolefin compound as a compatibilizer. The third aspect is that in the first or second aspect, the intermediate layer contains an acid-modified polyolefin compound as a compatibilizer. The fourth aspect is that in any one of the first to third aspects, the base material layer has, with the total of the resin composition being 100 parts by weight, 40 to 60 parts by weight of the polyester resin other than the liquid crystal polymer, 20 to 40 parts by weight of the low melting point liquid crystal polymer, and 5 to 30 parts by weight of the acid-modified polyethylene resin.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide an adhesive sealing film for a fuel cell using a resin composition capable of suppressing a decrease in tensile fracture stress.

Brief Description of the Drawings

[0009]

Figure 1

Modes for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described based on preferred embodiments.

[0011] The adhesive sealing film 10 for a fuel cell according to the embodiment has a base material layer 11 made of a resin as a forming material, and adhesive layers 13 laminated on both surfaces of the base material layer 11 via intermediate layers 12, respectively. The layer structure of the adhesive sealing film 10 for a fuel cell consists of five layers: adhesive layer 13 / intermediate layer 12 / base material layer 11 / intermediate layer 12 / adhesive layer 13.

[0012] The base material layer 11 is formed from a resin composition containing a polyester resin other than a liquid crystal polymer, a low melting point liquid crystal polymer having a crystal melting temperature of 250°C or lower, and an acid-modified polyethylene resin.

[0013] The base material layer 11 contains a polyester resin other than a liquid crystal polymer. These polyester resins are non-liquid crystal polyester resins, and may be, for example, linear polyester resins obtained by condensation polymerization of a dicarboxylic acid component and a diol component.

[0014] Examples of the dicarboxylic acid component of the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene-1,4-dicarboxylic acid, and naphthalene-2,6-dicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid. Examples of the diol component of the polyester resin include linear diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexamethylene diol; branched diols such as neopentyl glycol and 2,2-dialkyl-1,3-propanediol; and cyclic diols such as cyclopentane dimethanol and cyclohexane dimethanol. Examples of the alkyl group of the side chain branched from the main chain of the branched diol include a methyl group, an ethyl group, a propyl group, and a butyl group.

[0015] Specific examples of the polyester resin are not particularly limited, and include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, and modified polyesters obtained by modifying part of the dicarboxylic acid component and / or diol component in these polyesters with other dicarboxylic acid components and / or diol components.

[0016] The base material layer 11 contains a low melting point liquid crystal polymer having a crystal melting temperature of 250°C or lower. The liquid crystal polymer is a thermoplastic resin that exhibits liquid crystallinity when melted, and a liquid crystal polymer made of a polyester resin is preferred. The polyester resin other than the liquid crystal polymer may be a thermoplastic resin that does not exhibit liquid crystallinity when melted.

[0017] The low melting point liquid crystal polymer may be composed of only one type of low melting point liquid crystal polymer, or may be a mixture of multiple types of low melting point liquid crystal polymers. The low melting point liquid crystal polymer may be a liquid crystal polyester or liquid crystal polyester amide that forms an anisotropic molten layer called a thermotropic liquid crystal polymer, and a liquid crystal polyester is preferred.

[0018] The crystal melting temperature of the low melting point liquid crystal polymer is the temperature of the crystal melting peak measured using a differential scanning calorimeter. The measurement method using a differential scanning calorimeter is as follows: after observing the endothermic peak temperature (Tm1) observed when measuring under a temperature rising condition of 20°C / min from room temperature, hold at a temperature 20 to 50°C higher than Tm1 for 10 minutes, then cool the sample to room temperature under a temperature falling condition of 20°C / min, and then observe the endothermic peak when measuring again under a temperature rising condition of 20°C / min. The temperature indicating the peak top is taken as the crystal melting temperature of the liquid crystal polymer. The crystal melting temperature of the low melting point liquid crystal polymer is 250°C or lower, preferably 160°C to 240°C, more preferably 170°C to 230°C, and particularly preferably 200°C to 230°C.

[0019] Examples of the repeating units constituting the low melting point liquid crystal polymer include aromatic hydroxycarboxylic acid units (-O-Ar-CO-), aromatic dicarboxylic acid units (-CO-Ar-CO-), aromatic diol units (-O-Ar-O-), aromatic aminocarboxylic acid units (-NH-Ar-CO-), aromatic hydroxyamine units (-O-Ar-NH-), aromatic diamine units (-NH-Ar-NH-), aliphatic diol units (-O-Ra-O-), and aliphatic dicarboxylic acid units (-O-Ra-O-). Here, -Ar- represents an aromatic group, and -Ra- represents an aliphatic group. The -CO- groups contained in these units are not limited to those derived from carboxylic acids (-CO-OH), and may also be derived from acyl compounds (-CO-O-COR), ester derivatives (-CO-OR), acid halides (-CO-X), etc. Further, the -O- group and -NH- group are not limited to those derived from hydroxy groups (-OH) and amino groups (-NH2), respectively, and may also be derived from acyl compounds (-O-COR and -NH-COR), etc. Here, R represents an organic group such as an alkyl group or an aryl group, and X represents a halogen atom. If a polyester is formed as the low melting point liquid crystal polymer, the repeating units constituting these liquid crystal polymers may be only one kind or a combination of two or more kinds, but it is desirable to contain at least one kind of hydroxycarboxylic acid unit. As the low melting point liquid crystal polymer, an all-aromatic low melting point liquid crystal polymer in which each repeating unit contains an aromatic group is preferable.

[0020] Specific examples of the aromatic hydroxycarboxylic acid units include units derived from 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, and their alkyl, alkoxy or halogen-substituted derivatives. Among these, units derived from one or more selected from the group consisting of 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are preferred from the viewpoint of easily adjusting the heat resistance, mechanical strength and melting point of the resulting liquid crystal polymer.

[0021] Specific examples of the aromatic dicarboxylic acid units include units derived from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3,4'-dicarboxybiphenyl and 4,4''-dicarboxytriphenyl, and their alkyl, alkoxy or halogen-substituted derivatives. Among these, units derived from one or more selected from the group consisting of terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid are preferred from the viewpoint of effectively enhancing the heat resistance of the resulting liquid crystal polymer, and terephthalic acid units or 2,6-naphthalenedicarboxylic acid units are more preferred.

[0022] Specific examples of the aromatic diol units include units derived from hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, and 2,2'-dihydroxybinaphthyl, and their alkyl, alkoxy, or halogen-substituted derivatives. Among these, from the viewpoint of excellent reactivity during polymerization, units derived from one or more selected from the group consisting of hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene are preferred, and units derived from one or more selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl, and 2,6-dihydroxynaphthalene are more preferred.

[0023] Specific examples of the aliphatic diol units include units derived from ethylene glycol, 1,4-butanediol, and 1,6-hexanediol. Also, during production, a polymer containing an aliphatic diol such as polyethylene terephthalate or polybutylene terephthalate may be reacted with the above-mentioned aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, and their acylates, ester derivatives, acid halides, etc.

[0024] Specific examples of the aliphatic dicarboxylic acid units include units derived from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, fumaric acid, maleic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydroterephthalic acid. Among these, from the viewpoint of excellent reactivity during polymerization, units derived from oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, and 1,4-cyclohexanedicarboxylic acid are preferred.

[0025] The base material layer 11 contains an acid-modified polyethylene resin. Examples of the polyethylene include low-density polyethylene, high-density polyethylene, linear low-density polyethylene, and the like. The proportion of the acid-modified polyethylene resin in the base material layer 11 is, for example, 5 to 30% by weight.

[0026] Examples of the method for producing the acid-modified polyethylene resin include a method of graft-modifying an unmodified polyethylene resin with an acid-functional group-containing monomer by melt-kneading, a method of copolymerizing an ethylene monomer and an acid-functional group-containing monomer, and the like. Examples of the acid-functional group-containing monomer include a carboxylic acid group-containing monomer and an acid anhydride group-containing monomer. Examples of the carboxylic acid group-containing monomer include α,β-unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, maleic acid, nadic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, tetrahydrophthalic acid, and endo-bicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid (endomethylene dicarboxylic acid). Examples of the acid anhydride group-containing monomer include unsaturated dicarboxylic acid anhydride monomers such as maleic anhydride, nadic anhydride, itaconic anhydride, citraconic anhydride, and endo-methylene dicarboxylic acid anhydride.

[0027] Examples of the method for producing the resin composition of the base material layer 11 include a method of blending a polyester resin, a low-melting-point liquid crystal polymer, and an acid-modified polyethylene resin by a method such as melt-kneading. After blending two of the three types of polyester resin, low-melting-point liquid crystal polymer, and acid-modified polyethylene resin first, the remaining one type may be added and blended. The apparatus for melt-kneading is not particularly limited, and a single-screw extruder, a multi-screw extruder, a Banbury mixer, a plast mill, a heating roll kneader, or the like can be used. Further, blending can also be achieved by dry-blending a polyester resin, a low-melting-point liquid crystal polymer, and an acid-modified polyolefin and then forming a film with an extruder or the like.

[0028] As a result of blending, the resin composition of the base material layer 11 may form a sea-island structure in which the polyester resin constitutes the sea portion and the low melting point liquid crystal polymer and the acid-modified polyethylene resin each constitute an island portion. Since the acid-modified polyethylene resin is well dispersed with respect to the polyester resin and the low melting point liquid crystal polymer, hydrolysis of ester bonds and the like contained in the polyester resin and the low melting point liquid crystal polymer can be suppressed even in a high temperature and high humidity environment such as during thermoforming. Furthermore, a decrease in the tensile fracture stress of the resin composition can be suppressed.

[0029] Assuming the total of the resin composition of the base material layer 11 is 100 parts by weight, it is preferable that the polyester resin other than the liquid crystal polymer is 40 to 60 parts by weight, the low melting point liquid crystal polymer is 20 to 40 parts by weight, and the acid-modified polyethylene resin is 5 to 30 parts by weight. It is preferable that the proportion of the polyester resin other than the liquid crystal polymer is more than the proportion of the low melting point liquid crystal polymer, and it is preferable that the proportion of the low melting point liquid crystal polymer is more than the proportion of the acid-modified polyethylene resin.

[0030] The resin composition of the base material layer 11 may contain optional components. Examples of optional resin components include polyolefin resins, olefin-based elastomers, styrene-based elastomers, etc. Examples of additives, although not particularly limited, include fillers, colorants, antioxidants, defoaming agents, leveling agents, light absorbers, etc.

[0031] The resin composition of the base material layer 11 may contain an acid-modified polyolefin compound as a compatibilizer. Examples of the acid-modified polyolefin compound include acid-modified polyolefins selected from the range of molecular weights of 9000 to 160000. Examples of the acid-modified polyethylene resin of the base material layer 11 described above include acid-modified polyethylene having a molecular weight of 200000 or more. The proportion of the compatibilizer in the base material layer 11 may be 1 to 3% by weight.

[0032] The resin composition of the base material layer 11 may be a composition that does not contain a high melting point liquid crystal polymer with a crystal melting temperature exceeding 250°C. Further, the resin composition of the base material layer 11 may be a composition that does not contain a resin component with a melting temperature (melting point) exceeding 250°C. The thickness of the base material layer 11 is not particularly limited, but examples include 60 to 120 μm.

[0033] The intermediate layer 12 is formed of an acid-modified polyethylene resin or an imine-modified polyolefin resin. Examples of the acid-modified polyethylene resin of the intermediate layer 12 include a graft polymer obtained by graft-modifying an unmodified polyethylene resin with an acid functional group-containing monomer by melt kneading, a copolymer obtained by copolymerizing an ethylene monomer and an acid functional group-containing monomer, etc. Examples of the acid functional group-containing monomer include the carboxylic acid group-containing monomer and the acid anhydride group-containing monomer. Examples of the polyethylene include low density polyethylene, high density polyethylene, linear low density polyethylene, etc. Examples of the imine-modified polyolefin resin of the intermediate layer 12 include a polymer compound obtained by modifying a polyolefin resin such as a polyethylene resin or polypropylene with an imine compound.

[0034] The intermediate layer 12 can improve the adhesive strength (interlayer peeling strength) between the base material layer 11 and the adhesive layer 13. The thickness of the intermediate layer 12 is not particularly limited, but examples include 1 to 20 μm. The acid-modified polyethylene resin contained in the intermediate layer 12 may be of the same grade or a different grade from the acid-modified polyethylene resin contained in the base material layer 11.

[0035] The intermediate layer 12 may contain an acid-modified polyolefin compound as a compatibilizer. Examples of the acid-modified polyolefin compound include an acid-modified polyolefin selected from the range of a molecular weight of 9000 to 160000. Examples of the acid-modified polyethylene resin of the intermediate layer 12 described above include an acid-modified polyethylene with a molecular weight of 200000 or more. The proportion of the compatibilizer in the intermediate layer 12 includes 1 to 3% by weight.

[0036] The resin composition of the intermediate layer 12 may contain optional components. Examples of optional resin components include polyolefin resins, olefin-based elastomers, styrene-based elastomers, and the like. Examples of additives, although not particularly limited, include fillers, colorants, antioxidants, defoamers, leveling agents, light absorbers, and the like.

[0037] The adhesive layer 13 is formed of an adhesive polypropylene resin such as an acid-modified polypropylene resin. Examples of the acid-modified polypropylene resin include a graft polymer obtained by graft-modifying a non-acid-modified polypropylene resin with an acid functional group-containing monomer by melt kneading, a copolymer obtained by copolymerizing a propylene monomer and an acid functional group-containing monomer, and the like. Examples of the acid functional group-containing monomer include the carboxylic acid group-containing monomer and the acid anhydride group-containing monomer. Examples of polypropylene include homopolypropylene, block polypropylene, random polypropylene, and the like.

[0038] The adhesive layer 13 can obtain good adhesiveness to the adherend of the adhesive sealing film 10 for fuel cells. The thickness of the adhesive layer 13 is not particularly limited, but examples include 10 to 40 μm.

[0039] The resin composition of the adhesive layer 13 may contain optional components. Examples of optional resin components include polyolefin resins, olefin-based elastomers, styrene-based elastomers, and the like. Examples of additives, although not particularly limited, include fillers, colorants, antioxidants, defoamers, leveling agents, light absorbers, and the like. As the antioxidant, phenolic, phosphite-based, thioether-based, etc. can be used alone or in combination. In particular, it is preferable to add an antioxidant to the resin layer that becomes the outermost layer.

[0040] The adhesive sealing film 10 for fuel cells according to the embodiment can be used as an adhesive material, a sealing material, etc. in a fuel cell. The adhesive sealing film 10 for fuel cells according to the embodiment can be suitably applied, for example, to the gasket of a fuel cell.

[0041] As the electrolyte membrane of the fuel cell, a known or commercially available solid polymer electrolyte membrane can be used. For example, a hydrogen ion conductive polymer electrolyte, a perfluorosulfonic acid-based fluorine ion exchange resin, an anion conductive solid polymer electrolyte membrane, etc. can be mentioned. On the surface of the electrolyte membrane, a catalyst layer such as platinum, a platinum alloy, or a platinum compound is laminated as a cathode catalyst or an anode catalyst. In the cell of the fuel cell, gaskets are arranged on both sides of the membrane electrode assembly including the electrolyte membrane and the catalyst layer via sub-gaskets. The sub-gaskets and the gaskets are formed in an annular or frame shape so as to surround the outer periphery of the membrane electrode assembly.

Examples

[0042] Hereinafter, the present invention will be specifically described with examples.

[0043] <Base material layer> A polymer alloy of a polyester resin and a low melting point liquid crystal polymer and an acid-modified polyethylene resin were melt-kneaded, and the obtained resin composition was formed into a film with a thickness of 90 μm to obtain a base material layer.

[0044] As the polyester resin and the low melting point liquid crystal polymer, a polymer alloy (trade name: TECROS (registered trademark) T-440HS, manufactured by Ueno Pharmaceutical Co., Ltd., denoted as "PET / LCP" in the table) in which polyethylene terephthalate (PET) and liquid crystal polymer (LCP) were blended at a weight ratio of 60:40 was used. The liquid crystal polymer contained in this polymer alloy is a low melting point liquid crystal polymer having a crystal melting temperature of 220°C.

[0045] As the acid-modified polyethylene resin, a commercially available acid-modified polyethylene (trade name: Admer (registered trademark) SF728, manufactured by Mitsui Chemicals, Inc., denoted as "APE" in the table) was used. In No. 1, only PET / LCP (without APE) was used, in No. 2, PET / LCP and APE were in a weight ratio of 90:10, and in No. 3, PET / LCP and APE were in a weight ratio of 80:20.

[0046] The measurement of the tensile breaking stress was carried out on samples obtained by punching the film of the obtained base material layer into dumbbell shapes of No. 5. The measurement was performed under the conditions of a chuck distance of 80 mm, a gauge length of 45 mm, and a tensile speed of 300 mm / min. After preparing each sample so that the tensile direction was the MD direction (flow direction) or the TD direction (width direction), the tensile breaking stress was determined from the cross-sectional area (width 6 mm, thickness 0.09 mm) at the narrow part of the sample width.

[0047] The pressure cooker test (PCT) was carried out under the conditions of 110 °C, 85% RH, and 96 h. The tensile breaking stress before and after PCT was measured for the same sample, and the retention rate before and after PCT was calculated. This retention rate is obtained by (tensile breaking stress after PCT) / (tensile breaking stress before PCT) × 100 (%). The measurement results of the tensile breaking stress are shown in Table 1.

[0048]

Table 1

[0049] As shown in Table 1, it was confirmed that by blending the acid-modified polyethylene resin, the decrease in the tensile breaking stress after PCT can be suppressed.

[0050] <Adhesive sealing film for fuel cell> An adhesive sealing film for fuel cells composed of five layers of adhesive layer / intermediate layer / base material layer / intermediate layer / adhesive layer was fabricated. The thickness of the intermediate layer was 5 μm and the thickness of the adhesive layer was 25 μm.

[0051] As the intermediate layer for Nos. 1 to 3, the same grade of APE as the acid-modified polyethylene resin used for the base material layer was used. For the intermediate layers of Nos. 4 to 6, APE and a compatibilizer were blended at a weight ratio of 98:2. The compatibilizers used were C1 (trade name: Yumex (registered trademark) 1001, manufactured by Sanyo Chemical Industries, Ltd., acid-modified polypropylene resin) for No. 4, C2 (trade name: Rikeaid (registered trademark) MG-670P, manufactured by Riken Vitamin Co., Ltd., acid-modified polypropylene resin) for No. 5, and C3 (trade name: Rikeaid (registered trademark) KG-005P, manufactured by Riken Vitamin Co., Ltd., silica-based polypropylene resin) for No. 6.

[0052] As the adhesive layer, two types of acid-modified polypropylene resins (trade name: Admer (registered trademark) QE060, manufactured by Mitsui Chemicals, Inc., designated as "APP1" in the table) and (trade name: Admer (registered trademark) QF575, manufactured by Mitsui Chemicals, Inc., designated as "APP2" in the table) and an antioxidant (a mixture of phenolic, phosphite, and thioether types) were blended at a weight ratio of 55:40:5 and added at 3500 ppm to the resin component of the adhesive layer.

[0053] The interlayer peeling strength of the adhesive sealing film for fuel cells was measured as the average of N = 3 (the average of the measured values measured three times). The results are shown in Table 2.

[0054]

Table 2

[0055] As shown in Table 2, when the compatibilizer was not used, the sample of No. 2 had the highest interlayer peeling strength. When the compatibilizer was used, the interlayer peeling strength was further improved.

Explanation of Symbols

[0056] 10... Adhesive sealing film for fuel cells, 11... Base material layer, 12... Intermediate layer, 13... Adhesive layer.

Claims

1. An adhesive sealing film for a fuel cell, comprising a base material layer made of a resin as a forming material and adhesive layers laminated on both sides of the base material layer via intermediate layers respectively, wherein the base material layer is formed from a resin composition containing a polyester resin other than a liquid crystal polymer, a low melting point liquid crystal polymer having a crystal melting temperature of 250°C or lower, and an acid-modified polyethylene resin, the intermediate layer is formed from an acid-modified polyethylene resin or an imine-modified polyolefin resin, and the adhesive layer is formed from an acid-modified polypropylene resin. Adhesive sealing film for a fuel cell.

2. The adhesive sealing film for a fuel cell according to Claim 1, wherein the base material layer contains an acid-modified polyolefin compound as a compatibilizer.

3. The adhesive sealing film for a fuel cell according to Claim 1, wherein the intermediate layer contains an acid-modified polyolefin compound as a compatibilizer.

4. The adhesive sealing film for a fuel cell according to Claim 1, wherein, taking the total amount of the resin composition as 100 parts by weight, the polyester resin other than the liquid crystal polymer is in a proportion of 40 to 60 parts by weight, the low melting point liquid crystal polymer is in a proportion of 20 to 40 parts by weight, and the acid-modified polyethylene resin is in a proportion of 5 to 30 parts by weight.

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