JP2007169550A - Composition for resin molding and separator for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molded body composition capable of providing a resin molded body having excellent conductivity and mechanical properties substantially without a cooling step, and excellent conductivity obtained from the resin molded body composition To provide a fuel cell separator having mechanical properties.
SOLUTION: When a resin molded body composition is melt-molded with a resin molded body composition containing a polyphenylene sulfide resin, an aromatic polyester, an epoxy resin and a conductive filler, the polyphenylene sulfide and the aromatic polyester are mixed. When a reaction occurs and the aromatic polyester further reacts with the epoxy resin, a crosslinked structure is formed in the resin molding. For this reason, the composition for resin moldings of this invention can hold | maintain the shape shape shape | molded by the short cooling solidification time after melt molding, or without passing through a cooling process.
[Selection figure] None

Description

  The present invention relates to a resin molded body composition suitable for fuel cell separator parts and the like, which require molding processability, acid resistance, and conductivity in addition to excellent mechanical properties, and a fuel cell separator.

  In recent years, fuel cells have attracted attention as a next-generation energy source that emits less carbon dioxide because of efforts to deal with environmental problems on a global scale. Among them, the solid polymer electrolyte fuel cell is promising as a power source for household cogeneration (cogeneration) system and automobile because it can be operated at a temperature of around 80 ° C. These fuel cells use a flat separator having a gas flow path, which is an important component of the fuel cell.

  The separator has been conventionally processed by press-molding expanded graphite, or by heat-melting a mixture of a thermosetting resin or thermoplastic resin and a conductive filler such as carbon black or graphite powder, and by press molding or the like. There have been proposed a method of processing after forming into a flat plate, a method of graphitizing the formed plate in order to impart conductivity, and the like. Due to post-processing such as firing and cutting, the production efficiency is poor, the cost is very high, and the practical level is not reached.

  Therefore, a compression molding method has been proposed in which a conductive filler is added to a thermosetting resin, and the molding is performed at a temperature higher than the thermosetting temperature in the mold, and if this method is used, the molding cycle is shortened and the productivity problem is reduced. Can be overcome. (Patent Document 1)

However, conventional thermosetting resins such as phenol resin, urea resin, unsaturated polyester resin, alkyd resin, epoxy resin, and diallyl phthalate resin are poor in mechanical properties of the resin itself, and a fuel cell filled with a large amount of conductive filler. Separators have the disadvantage of being brittle and easy to break. For example, when it is used for a mobile object (such as an automobile), there is a risk that it may be damaged by vibration, resulting in lack of reliability.
Development of a separator using a so-called engineering plastic having excellent mechanical properties as a matrix resin has been promoted with respect to the problem of the separator using the thermosetting resin. Among these, polyphenylene sulfide resins are attracting attention because of their relatively low viscosity and excellent moldability (Patent Documents 2 and 3). However, in injection molding, which is a general polyphenylene sulfide molding method, if a large amount of graphite is filled to satisfy the electrical conductivity required for the separator, the fluidity of the compound is lowered and injection molding becomes impossible. Further, if the amount of graphite used is limited to such an extent that it can be injection molded, there is a problem that the conductivity is lowered, the internal resistance of the fuel cell separator using the graphite is increased, and the power generation efficiency of the fuel cell is lowered. When the melt viscosity of the polyphenylene sulfide resin is lowered as another method, the durability and mechanical properties are greatly reduced, and this is not a fundamental solution (Patent Document 4). Therefore, a method has been proposed in which a polyphenylene sulfide resin and a conductive filler are processed into a sheet shape in advance, and are heated and compressed using a mold (Patent Document 5). However, in this method, it is necessary to heat and heat the sheet above the melting point of the polyphenylene sulfide resin and then to cool and solidify it to a temperature below the melting point (the crystallization temperature or below). Otherwise, the physical properties (strength, toughness, etc.) of the polyphenylene sulfide resin cannot be exhibited sufficiently. In this case, it takes time to heat and cool the sheet and the mold, and there is a problem that the productivity of the separator is inferior. Moreover, the loss of thermal energy is large, and there is a problem from the viewpoint of energy saving.

JP-A-2005-89653 JP2001-122777A JP 2004-269567 A JP2005-5094 JP 2004-356091 A

  In view of these problems, the problem to be solved by the present invention is a resin molded body composition capable of providing a resin molded body having excellent conductivity and mechanical properties substantially without a cooling step, and the resin. An object of the present invention is to provide a fuel cell separator having excellent conductivity and mechanical properties obtained from a molded body composition.

  In the present invention, by including an aromatic polyester and an epoxy resin in the composition forming the resin molded body, the polyphenylene sulfide and the aromatic polyester react when melt-molding the resin molded body composition. Further, the aromatic polyester reacts with the epoxy resin, whereby a crosslinked structure is formed in the resin molded body. For this reason, the composition for resin moldings of this invention can hold | maintain the shape shape shape | molded in the short cooling solidification time after melt molding, or even without passing through a cooling process.

  Since the resin molded body composition of the present invention has a small temperature difference until it is cooled and solidified after melt molding, energy loss is small, and solidification and demolding can be performed in a short time, so that the molding cycle can be accelerated. For this reason, since a resin molded body can be efficiently produced by compression molding with good productivity, a resin molded body can be formed at low cost and with high productivity even when mass-producing resin molded bodies. Furthermore, the obtained resin molding has excellent electrical conductivity, excellent physical properties such as rigidity, heat resistance, and solvent resistance derived from cross-linked polyphenylene sulfide, and excellent mechanical properties derived from aromatic polyester. Therefore, it is useful as a fuel cell separator.

  The resin molded body composition of the present invention contains a polyphenylene sulfide resin, an aromatic polyester, an epoxy resin, and a conductive filler.

[Polyphenylene sulfide resin]
The polyphenylene sulfide resin used in the present invention is a polymer containing a repeating unit having a structure in which an aromatic ring and a sulfur atom are bonded. Of these, a structure bonded at the para position with respect to the aromatic ring is preferable in terms of heat resistance and crystallinity. The melt viscosity of the polyphenylene sulfide resin is preferably 10 Pa · s to 1000 Pa · s at a temperature of 300 ° C., and the low-viscosity product has better fluidity during molding, while the high-viscosity product has better rigidity.

[Aromatic polyester resin]
The aromatic polyester resin used in the present invention is a polyester resin comprising an aromatic dicarboxylic acid component and a bisphenol or biphenol component. This aromatic polyester resin can be produced using a known method. For example, a method of producing an aromatic polyester by an interfacial polymerization method by contacting an organic solvent solution of an aromatic dicarboxylic acid halide with an alkaline aqueous solution of bisphenols or biphenols, an aromatic dicarboxylic acid halide, and a bisphenol Alternatively, an organic solvent solution of biphenols is contacted in the presence of a dehydrochlorinating agent such as amine, and an aromatic polyester is produced by a solution polymerization method. A bisphenol or biphenol diacetate and phthalic acid are mixed. And a method of producing an aromatic polyester resin by a melt polymerization method by heating and reducing pressure to remove acetic acid produced.

  As the aromatic dicarboxylic acid component of the aromatic polyester, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid are used. These aromatic dicarboxylic acids may be copolymerized alone or in combination of two or more, and aliphatic dicarboxylic acids such as succinic acid, adipic acid, suberic acid, and sebacic acid may be copolymerized.

  Examples of bisphenol include bisphenol A, 3,3 ′, 5,5′-tetramethyl-biphenol A, bisphenol F, 3,3 ′, 5,5′-tetramethyl-biphenol F, 4,4′-dihydroxybenzophenone, Examples of bisphenols such as 9,9-bis- (4-hydroxyphenyl) fluorene include 4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 3,3. Examples include ', 5,5'-tetrabutyl-4,4'-biphenol and 1,1'-2-binaphthol. Of these, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol is preferable because of its good reactivity with the epoxy resin. Two or more of these bisphenols or biphenols may be copolymerized alone.

  Furthermore, a compound having both a carboxylic acid component such as hydroxybenzoic acid and a phenol component may be introduced into the aromatic polyester resin.

  Monofunctional phenols can be used in combination to adjust the molecular weight of the resulting aromatic polyester. Examples of the monofunctional phenols include phenol, o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,6-xylenol, 2,4,6-tetramethylphenol, p-tertiary butylphenol, m-tertiary butylphenol, o-tertiary butylphenol, 2,4-ditertiary butylphenol, 2,6-ditertiary butylphenol, p-secondary butylphenol, m-secondary butylphenol, o-secondary butylphenol, 2,4-disecondary butylphenol 2,6-disecondary butylphenol, p-octylphenol, p-phenylphenol, and the like. If the addition amount of this monofunctional phenol exceeds 20 mol% with respect to tetramethylbiphenol, an ester monomer containing a monofunctional phenol directly at both ends of the dicarboxylic acid component can be easily formed, and the solubility in organic solvents is increased. Inferior ingredients are by-produced.

  The polyphenylene sulfide and aromatic polyester used in the present invention are preferably in the form of powder or nonwoven fabric because they can be easily mixed uniformly with the conductive filler and other raw materials. Further, a polyphenylene sulfide resin and an aromatic polyester resin may be, for example, melt-kneaded and then molded into a nonwoven fabric.

[Epoxy resin]
As the epoxy resin used in the present invention, a known bisphenol type epoxy resin, biphenol type epoxy resin, novolak type epoxy resin, or the like can be used. For example, bisphenol components include bisphenol A, 3,3 ′, 5,5′-tetramethyl-biphenol A, bisphenol F, 3,3 ′, 5,5′-tetramethyl-biphenol F, dicyclopentadiene diphenol, Biphenol components such as bisphenol S, dihydroxydiphenyl ether, 4,4′-dihydroxybenzophenone and 9,9-bis- (4-hydroxyphenyl) fluorene include 4,4′-biphenol, 3,3 ′, 5,5 ′. -Tetrabutyl-4,4'-biphenol, 1,1'-2-binaphthol and the like. Examples of the novolak component include phenol novolak, cresol novolak, naphthol novolak, dihydroxynaphthalene novolak, and the like.

  Of these epoxy resins, novolak type epoxy resins are preferable because of the large number of epoxy groups per molecule. In addition, powder is preferable because it can be easily mixed with polyphenylene sulfide resin, aromatic polyester resin, and conductive filler.

[Conductive filler]
Examples of the conductive filler used in the present invention include known carbon materials, metals, metal compounds, and the like, and these conductive fillers can be used alone or in combination of two or more.

  The size of the conductive filler is not particularly limited as long as it can be uniformly distributed, but the average particle diameter is preferably in the range of 1 to 800 μm in terms of the conductivity and mechanical properties of the molded separator, 50-600 micrometers is especially preferable. Among them, the carbon material is preferable because it is lightweight and excellent in corrosion resistance, and examples thereof include artificial graphite, natural graphite, glassy carbon, carbon black, acetylene black, and ketjen black. These carbon materials can be used alone or in combination of two or more. There is no restriction | limiting in particular in the shape of the granular material of these carbon materials, Any of plate shape, spherical shape, fibrous shape, an amorphous shape, etc. may be sufficient. Also, expanded graphite obtained by chemically treating graphite can be used. In view of conductivity, artificial graphite, natural graphite, expanded graphite and the like are preferable in that a separator having a high degree of conductivity can be obtained in a smaller amount.

[Composition for resin molding]
The resin molding composition of the present invention contains the polyphenylene sulfide resin, aromatic polyester, epoxy resin and conductive filler, and contains the aromatic polyester and epoxy resin together with the polyphenylene sulfide resin. When the composition for resin molding is melt-molded, the polyphenylene sulfide and the aromatic polyester react with each other, and further, the aromatic polyester reacts with the epoxy resin, thereby forming a crosslinked structure in the resin molding. The For this reason, the composition for resin moldings of this invention can hold | maintain the shape shape shape | molded by the short cooling solidification time after melt molding, or without passing through a cooling process.

  The mixing ratio of each component in the resin molding composition can be determined by the ratio of the number of ester functional groups of the aromatic polyester resin to the number of epoxy functional groups of the epoxy resin. The number of these functional groups can be calculated from ester equivalent (g / eq, molecular weight per ester functional group) or epoxy equivalent (g / eq, molecular weight per epoxy functional group). In the case of the present invention, the ratio of the number of ester functional groups of the aromatic polyester resin to the number of epoxy functional groups of epoxy resin is preferably the number of ester functional groups / number of epoxy functional groups = 1 to 5. If there are more epoxy resins than this, an epoxy group will remain in the molded product, and if it is less than this, the progress of the curing reaction is small, which is not preferable.

  The mixing mass ratio of the mixture of the aromatic polyester resin and the epoxy resin and the polyphenylene sulfide resin is (aromatic polyester resin + epoxy resin) / polyphenylene sulfide resin = 0.05 to 1 in the range of the polyphenylene sulfide resin. It is preferable because the mechanical properties can be maintained, more preferably in the range of 0.1 to 0.8.

  In the present invention, a catalyst can be used in combination to promote the reaction between the aromatic polyester resin and the epoxy resin. Examples of the catalyst include known ammonium salt catalysts, amine-based catalysts, and imidazole-based catalysts. For example, tetramethylammonium chloride, tetramethylammonium bromide, pyridine, aniline, dimethylaniline, dimethylaminopyridine, imidazole, methylimidazole, Examples include dimethylimidazole.

  The addition amount of these catalysts is preferably 0.01 to 1% by mass, and more preferably 0.05 to 0.1% by mass with respect to the epoxy resin.

  The mixing mass ratio of the conductive filler is preferably 70% to 85% with respect to the total amount of the polyphenylene sulfide resin, the aromatic polyester resin, and the epoxy resin, and the range of 75% to 85% is the conductivity and strength of the separator. The balance is good and more preferable.

  The resin molding composition of the present invention may be a powder mixed composition obtained by powder-mixing a polyphenylene sulfide resin, an aromatic polyester, an epoxy resin conductive filler and a conductive filler, or a melt mixed composition obtained by melt mixing. In addition, in order to improve moldability and to uniformly mix each component, polyphenylene sulfide or aromatic polyester is mixed with other components as a nonwoven fabric, or polyphenylene sulfide resin and aromatic polyester resin are melt-kneaded in advance. A non-woven fabric may be mixed with other components.

  You may add various additives, such as another reinforcing material and a filler, to the resin molding composition of this invention as needed.

[Fuel cell separator]
The fuel cell separator of the present invention can be prepared by various molding methods using a desired separator-shaped mold or the like after powder-mixing or melt-mixing the conductive filler, polyphenylene sulfide resin, polyphenylene sulfide resin, and epoxy resin. It can be obtained by molding. In addition, as described above, the conductive filler is uniformly blended and laminated in a non-woven fabric made of polyphenylene resin or a mixture of polyphenylene resin and polyester resin, and then a desired separator-shaped mold is used. It can also be obtained by molding by various molding methods.

  Examples of the molding method include compression molding, transfer molding, injection compression molding, and the like. Of these, compression molding and transfer molding are preferred because they do not impair the object of the present invention.

  In this case, the melting temperature in the molding die can be appropriately selected between 280 ° C. and 360 ° C., but usually in the range of 280 ° C. to 340 ° C. in consideration of productivity, resin characteristics, and the like. In the present invention, the molded product can be taken out without cooling the mold after molding. When the separator composition is put in a mold as a powder, it is necessary to cool the mold once, so that the composition is melt-mixed or a conductive filler is laminated with a non-woven fabric of a resin component. The effect of this invention can be exhibited more by setting it to a metal mold | die after shape | molding in a stampable sheet form.

  Further, during the molding, other reinforcing materials, fillers and various additives can be added as necessary.

  Hereinafter, the present invention will be specifically described with reference to synthesis examples and examples, but the scope of the present invention is not limited thereto.

  A 250 mm × 250 mm × 2 mm flat molded product was used for gas sealability evaluation in the examples, evaluation of volume resistivity of the thickness method, and bending test. For evaluation of power generation characteristics of a single fuel cell, a molded product with ribs of 250 mm × 250 mm × 2 mm (FIG. 1) was used.

[Gas sealability evaluation]
A test piece having a diameter of 60 mm and a thickness of 2 mm was cut out from the flat plate-shaped product obtained in the examples described later, and the gas-sealing property of the flat plate-shaped product was determined in accordance with the gas permeation test method for plastic films and sheets of JIS K-7126. evaluated.

[Evaluation of volume resistivity in the thickness direction]
A test piece having a size of 50 mm square and a thickness of 2 mm was cut out from the flat plate-shaped product obtained in the examples described later, and a test piece having an area s and a thickness t was applied between the gold-plated electrode plates at a constant pressure, , The resistance c was measured, and the volume resistivity was measured by equation (1).
Volume resistivity in thickness direction = c × s / t (1)

[Bending test]
A test piece having a width of 25 mm, a length of 70 mm, and a thickness of 2 mm was cut out from the flat plate-shaped product obtained in Examples described later, and the bending strength of the flat plate-shaped product was measured in accordance with JIS K-6911.

[Evaluation of power generation characteristics of a single cell]
A membrane electrode assembly was placed between two molded products with ribs obtained in Examples below and fastened at 5 kg / cm ² to obtain a fuel cell single cell for power generation characteristic evaluation. Humidified hydrogen and air were supplied to the cell, and the voltage at a cell temperature of 80 ° C. and a current density of 100 mA / cm ² was measured.

(Synthesis example of aromatic polyester)
A reactor equipped with a stirring blade and a nitrogen inlet was charged with 48.46 g (0.20 mol) of 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol and 20 g (0.50 mol) of sodium hydroxide. Mol) was dissolved in 1000 ml of deoxygenated water to obtain an aqueous solution. Separately, 32.48 g (0.16 mol) of isophthalic acid chloride, 8.12 g (0.04 mol) of terephthalic acid chloride and 1.2 g of methyltrioctylammonium chloride were dissolved in 1000 ml of methylene chloride to obtain an organic solution.

The organic solution was added while stirring the aqueous solution in a nitrogen stream while maintaining the temperature at 12 ° C., and stirring was continued for 30 minutes. After stopping the stirring, the aqueous phase separated into the upper layer was removed, and then acetone was poured into the organic solution phase while stirring again to obtain a precipitate. The obtained precipitate was separated by filtration, washed with acetone and dried to obtain 72.0 g of an aromatic polyester resin powder.
The aromatic polyester had a weight average molecular weight of 350 × 10 ³ and an ester group equivalent of 186 g / eq.

Example 1
16 parts of polyphenylene sulfide resin powder (melt viscosity at 300 ° C. 30 Pa · s), 2.5 parts of tetramethylbiphenol type aromatic polyester resin (ester group equivalent 186 g / eq) obtained in the above synthesis example, and cresol novolak type A mixture of 1.5 parts of an epoxy resin (epoxy equivalent 214 g / eq) and 0.01 part of dimethylaminopyridine was mixed with 80 parts of artificial graphite (amorphous, average particle size 88 μm) as a conductive filler. The mixture was filled into a 250 mm × 250 mm × 2 mm flat plate mold, and the mold was set in a 300 ° C. hot press to melt the resin component, and then immediately pressurized at 60 MPa for 3 minutes. Next, the mold was taken out from the hot press machine, and the mold was opened to take out a flat plate-shaped product of 250 mm × 250 mm × 2 mm. The molding cycle from setting the mold to the hot press machine until taking out the molded product was 200 seconds. The obtained flat molded article had a hydrogen gas permeability of 3.0 × 10 ⁻⁵ cm ³ / sec · cm ² · Atm, a volume resistivity of 5 mΩ · cm, and a bending strength of 63 MPa.

Using a 250 mm × 250 mm × 2 mm ribbed molded product mold having the shape shown in FIG. 1, a ribbed molded product was also obtained in the same manner. The power generation amount of the single cell when the current density was 100 mA / cm ² at 80 ° C. was 785 mV.

(Example 2)
Polyphenylene sulfide resin powder (melt viscosity at 300 ° C. 30 Pa · s) was kneaded with an extruder and formed into a non-woven fabric by the spunbond method (weight per unit area: 25 g / m 2). 1. To 16 parts of this nonwoven fabric, 80 parts of artificial graphite (amorphous, average particle diameter of 88 μm) as a conductive filler and the tetramethylbiphenol type aromatic polyester resin (ester group equivalent 186 g / eq) obtained in the above synthesis example. 5 parts, a mixture of cresol novolac type epoxy resin (Epiclon N-695, manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent 214 g / eq) 1.5 parts and dimethylaminopyridine 0.01 part uniformly spread, 200 ° C. The non-woven fabric, artificial graphite, and other raw materials were fused together.
After cutting the non-woven fabric in which the artificial graphite and other raw materials are fused into a size of 250 mm × 250 mm, 30 sheets are stacked and filled in a 250 mm × 250 mm × 2 mm flat plate mold, and the heat pressing machine is heated to 300 ° C. After the mold was set and the resin component was melted, it was immediately pressurized at 60 MPa for 3 minutes. Next, the mold was taken out from the hot press machine, and the mold was opened to take out a flat plate-shaped product of 250 mm × 250 mm × 2 mm. The molding cycle from setting the mold to the hot press machine until taking out the molded product was 200 seconds. The obtained flat molded article had a hydrogen gas permeability of 3.0 × 10 ⁻⁵ cm ³ / sec · cm ² · Atm, a volume resistivity of 5 mΩ · cm, and a bending strength of 60 MPa.

Using a 250 mm × 250 mm × 2 mm ribbed molded product mold having the shape shown in FIG. 1, a ribbed molded product was also obtained in the same manner. The power generation amount of the single cell when the current density was 100 mA / cm ² at 80 ° C. was 780 mV.

(Example 3)
Extruded a mixture of 16 parts of polyphenylene sulfide resin powder (melt viscosity at 300 ° C. 30 Pa · s) and 2.5 parts of tetramethylbiphenol type aromatic polyester resin (ester group equivalent 186 g / eq) obtained in the above synthesis example The mixture was kneaded with a machine and formed into a nonwoven fabric by the spunbond method (weight per unit area: 25 g / m 2).

1. 80 parts of artificial graphite (amorphous, average particle diameter 88 μm) and cresol novolac type epoxy resin (Epiclon N-695 manufactured by Dainippon Ink & Chemicals, Inc., epoxy equivalent 214 g / eq) as a conductive filler in the obtained non-woven fabric. A mixture of 5 parts and 0.01 part of dimethylaminopyridine was spread uniformly, and a 200 ° C. heating plate was brought close to fuse the nonwoven fabric and artificial graphite. After cutting this non-woven fabric fused with artificial graphite into a size of 250 mm × 250 mm, 30 sheets are stacked and filled in a 250 mm × 250 mm × 2 mm flat plate mold, and the mold is placed in a 300 ° C. hot press machine. After setting and melting the resin component, it was immediately pressurized at 60 MPa for 3 minutes. Next, the mold was taken out from the hot press machine, and the mold was opened to take out a flat plate-shaped product of 250 mm × 250 mm × 2 mm. The molding cycle from setting the mold to the hot press machine until taking out the molded product was 200 seconds. The obtained flat molded article had a hydrogen gas permeability of 3.0 × 10 ⁻⁵ cm ³ / sec · cm ² · Atm, a volume resistivity of 5 mΩ · cm, and a bending strength of 64 MPa.

Using a 250 mm × 250 mm × 2 mm ribbed molded product mold having the shape shown in FIG. 1, a ribbed molded product was also obtained in the same manner. The power generation amount of the single cell when the current density was 100 mA / cm ² at 80 ° C. was 782 mV.

(Comparative Example 1)
20 parts of polyphenylene sulfide resin powder (melt viscosity of 30 Pa · s at 300 ° C.) was mixed with 80 parts of artificial graphite (amorphous, average particle diameter of 88 μm) as a conductive filler. The mixture was filled into a 250 mm × 250 mm × 2 mm flat plate mold, and the mold was set in a 300 ° C. hot press to melt the polyphenylene sulfide resin, and then immediately pressurized at 60 MPa for 3 minutes. The mold was then removed from the hot press and cooled for 30 seconds. The mold temperature at that time was 235 ° C. The molding cycle from setting the mold to the hot press machine until taking out the molded product was 237 seconds. When the mold was opened after cooling, the molded product was not solidified and could not be removed.

(Comparative Example 2)
20 parts of polyphenylene sulfide resin powder (melt viscosity of 30 Pa · s at 300 ° C.) was mixed with 80 parts of artificial graphite (amorphous, average particle diameter of 88 μm) as a conductive filler. The mixture was filled into a 250 mm × 250 mm × 2 mm flat plate mold, and the mold was set in a 300 ° C. hot press to melt the polyphenylene sulfide resin, and then immediately pressurized at 60 MPa for 3 minutes. The mold was then removed from the hot press and cooled for 180 seconds. The mold temperature at that time was 152 ° C. After cooling, the mold was opened and a 250 mm × 250 mm × 2 mm flat molded product was taken out. The molding cycle from setting the mold to the hot press machine until taking out the molded product was 288 seconds, which was 88 seconds longer than Example 1. The obtained flat molded article had a hydrogen gas permeability of 3.0 × 10 ⁻⁵ cm ³ / sec · cm ² · Atm, a volume resistivity of 5 mΩ · cm, and a bending strength of 52 MPa.

  Table 1 shows the results of the above Examples and Comparative Examples. As is clear from the examples, the resin molded body composition of the present invention can maintain the molded body shape without cooling time after compression molding. For this reason, as shown in the comparative example, there is no need to change the temperature from a high temperature during molding to a low temperature during cooling and solidification, so there is little energy loss during molding and the total molding time is shortened. It was possible to do.

It is a schematic diagram of a molded product mold with ribs.

Claims (12)

A composition for a resin molding, comprising a polyphenylene sulfide resin, an aromatic polyester, an epoxy resin, and a conductive filler. The composition for molded resin according to claim 1, wherein the aromatic polyester is an aromatic polyester comprising a phthalic acid residue and a tetramethylbiphenol residue. The resin molding composition according to claim 1 or 2, wherein the epoxy resin is a novolac type epoxy resin. The ratio for the number of ester functional groups of the aromatic polyester resin and the number of epoxy functional groups of epoxy resin (number of ester functional groups / number of epoxy functional groups) is 1 to 5. Composition for molded resin according to any one of claims 1 to 3 object. The mass ratio [(aromatic polyester resin + epoxy resin) / polyphenylene sulfide resin] of the mass sum of the aromatic polyester resin and the epoxy resin and the mass of the polyphenylene sulfide resin is 0.05 to 1. The composition for resin moldings in any one of 4. The composition for resin molding according to any one of claims 1 to 5, wherein the polyphenylene sulfide resin is a nonwoven fabric. The composition for resin molding according to any one of claims 1 to 5, which is a melt-kneaded product obtained by melt-kneading the polyphenylene sulfide resin and the aromatic polyester. The composition for resin molding of Claim 7 whose melt-kneaded material of the said polyphenylene sulfide resin and aromatic polyester is a nonwoven fabric form. A fuel cell separator obtained by compression molding the composition for molded resin according to any one of claims 1 to 8. The method for producing a resin molded body according to claim 9, wherein the polyphenylene sulfide resin is a nonwoven fabric. A method for producing a resin molding, comprising compression-molding a mixture containing a melt-kneaded product of a polyphenylene sulfide resin and an aromatic polyester, a conductive filler, and an epoxy resin. The method for producing a resin molded body according to claim 11, wherein the melt-kneaded product of the polyphenylene sulfide resin and the aromatic polyester is a nonwoven fabric.

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