JP5594035B2 - Separator for fuel cell and manufacturing method thereof - Google Patents

Description

  The present invention relates to a separator for a fuel cell, and in particular, a separator used for each unit cell of a fuel cell in which a plurality of unit cells each having an electrode disposed on both sides of a solid polymer electrolyte membrane are connected, and a method for producing such a separator. About.

A fuel cell is simply a device that continuously supplies fuel (reducing agent) and oxygen or air (oxidant) from the outside, and reacts electrochemically to extract electrical energy. It is classified by type, use, etc. Recently, depending on the type of electrolyte used, 5 types of solid oxide fuel cells, molten carbonate fuel cells, phosphoric acid fuel cells, solid polymer electrolyte fuel cells, and alkaline aqueous fuel cells are used. It is common to categorize roughly into types.
These fuel cells use hydrogen gas generated from methane or the like as a fuel. Recently, a direct methanol fuel cell (hereinafter also referred to as DMFC) that directly uses an aqueous methanol solution as a fuel is also known. Yes.
In such a fuel cell, a polymer electrolyte fuel cell having a structure in which a solid polymer membrane is sandwiched between two types of catalyst and these members are sandwiched between a gas diffusion layer (GDL) and a separator. (Hereinafter also referred to as PEFC) is attracting attention.
In this PEFC, in order to obtain a desired electromotive force, a unit cell in which an air electrode (oxygen electrode) is disposed on one surface of a solid polymer electrolyte membrane and a fuel electrode (hydrogen electrode) is disposed on the other surface is obtained. A stack structure in which a plurality of layers are stacked or a structure in which a plurality of planes are connected in series is taken. For example, in the case of the above-described stack structure, the separator disposed between the unit cells is formed with a fuel gas supply groove for supplying fuel gas to the adjacent unit cell on its side. An oxidant gas supply groove for supplying oxidant gas to the other adjacent unit cell is formed on the other surface.

As such a separator, a metal separator is preferable from the viewpoint of cost and strength, but there is a problem in corrosion resistance. For this reason, metal separators that have been provided with corrosion resistance by forming conductive electrodeposition coatings have been developed. However, when using a metal substrate such as aluminum, which is prone to oxide coating, and the electrodeposition coating is directly formed on this metal substrate, the electrodeposition coating has defects such as unevenness, chipping, and pinholes. It was difficult to form a uniform electrodeposition coating film, and there was a problem in the corrosion resistance in the power generation state under acidic conditions inside the fuel cell.
For this reason, a corrosion-resistant foundation layer is formed by laminating a Zn displacement plating layer, an intermediate layer (Cu plating layer, Ni plating layer), and an Au plating layer on a metal substrate having low corrosion resistance such as aluminum. A separator having a polyimide resin layer formed on an underlayer has been developed (Patent Document 1).

JP 2007-1113080 A

However, the formation of a corrosion-resistant underlayer having a multilayer structure has a problem that the number of steps is large and the production time is long, resulting in an increase in manufacturing cost. Further, due to the difference in thermal expansion coefficient between the aluminum base material and the multilayer corrosion-resistant underlayer, there is a problem that the corrosion-resistant underlayer easily cracks during use as a separator, and the corrosion resistance is not stably exhibited. Furthermore, since the corrosion-resistant underlayer is a multi-layer plating film, alloying at the interface of each plating layer progresses with long-term use at high temperatures, resulting in the generation of Kirkendall voids and causing deterioration. was there.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a separator for a fuel cell that is excellent in strength and corrosion resistance and has low connection resistance, and a method for manufacturing the same.

In order to achieve such an object, the separator of the present invention includes a metal substrate, a conductive resin layer formed by electrodeposition so as to cover the metal substrate, the metal substrate, and the resin. The metal base material is aluminum or an aluminum alloy, and the surface of the metal base material covered with the resin layer has an average roughness Ra of 1.5 to 10 μm. The metal particles are any one of tin , iron, nickel, and copper, or two or more metal particles, and the resin layer contains a conductive material. It was.
As another aspect of the present invention, the metal particles have an average particle diameter in the range of 5 to 500 nm and a presence density in the range of 20 to 250,000,000 / mm ² .

As another aspect of the present invention, the metal base material has a groove on at least one surface.
As another aspect of the present invention, the metal base material has a plurality of through holes.
As another aspect of the present invention, the conductive material is configured to be at least one of carbon particles, carbon nanotubes, carbon nanofibers, carbon nanohorns, and corrosion-resistant metals.
As another aspect of the present invention, the base metal layer, the metal particles, and the resin layer are provided with a base plating layer.

  The method for producing a separator for a fuel cell of the present invention uses a step of roughening a metal substrate made of aluminum or an aluminum alloy, and an electrodeposition liquid in which a conductive material is dispersed in a resin having electrodeposition properties. Forming a resin film on the rough surface of the metal substrate by electrodeposition, and then performing a thermosetting treatment to form a resin layer. In the roughening treatment, zinc, tin, iron, A configuration in which a treatment liquid containing any one of nickel and copper, or two or more metals or metal salts is brought into contact with each other to form a rough surface having an average roughness Ra in the range of 1.5 to 10 μm. did.

As another aspect of the present invention, the treatment liquid is configured such that the pH is in the acidic region, and the treatment liquid contains hydrochloric acid in a range of 0.1 to 5.0 mol / L, It was set as the structure which contains a metal or the said metal salt in 0.01-1.0 mol / L.
As another aspect of the present invention, the treatment liquid is configured such that the pH is in the alkaline region, and the treatment liquid contains a chelating agent in the range of 0.01 to 1.0 mol / L, It was set as the structure which contains the said metal or the said metal salt in 0.01-1.0 mol / L.
As another aspect of the present invention, the metal substrate is subjected to an oxide film removal process before the surface roughening process.

  In the separator of the present invention, the surface of a metal substrate made of aluminum or an aluminum alloy is a rough surface having an average roughness Ra of 1.5 to 10 μm, and predetermined metal particles are interposed on the rough surface to form a conductive resin. Since the layers are arranged, the metal substrate and the resin layer are firmly adhered to each other, and the electrical resistance in front-to-back conduction is low, and excellent corrosion resistance is achieved.

  In the method for producing a separator of the present invention, before forming a conductive resin layer on a metal substrate made of aluminum or an aluminum alloy by electrodeposition, a metal substrate is treated with a treatment liquid containing a predetermined metal or metal salt. The material is roughened to form a rough surface with an average roughness Ra in the range of 1.5 to 10 μm. At the same time, metal particles are precipitated on the rough surface. A resin layer is formed by electrodeposition by electrodeposition, and the rough surface of the metal substrate acts as an anchor to the resin layer, whereby the metal substrate and the resin layer are firmly adhered to each other. A separator having a low electrical resistance, good conductivity, excellent corrosion resistance, and capable of manufacturing a separator using a conventional metal substrate made of aluminum or an aluminum alloy. Base and process can be simplified, and the manufacturing cost can be reduced.

It is a fragmentary sectional view showing one embodiment of a separator for fuel cells of the present invention. It is a partial expanded sectional view of the separator for fuel cells shown by FIG. It is a fragmentary sectional view which shows other embodiment of the separator for fuel cells of this invention. It is a partial expanded sectional view of the separator for fuel cells shown by FIG. FIG. 4 is a partially enlarged sectional view corresponding to FIG. 2 showing another embodiment of the separator for a fuel cell of the present invention. It is process drawing for demonstrating one Embodiment of the manufacturing method of the separator of this invention. It is process drawing for demonstrating other embodiment of the manufacturing method of the separator of this invention. It is a partial block diagram for demonstrating an example of the polymer electrolyte fuel cell using the separator of this invention. It is a figure for demonstrating the membrane electrode assembly which comprises the polymer electrolyte fuel cell shown by FIG. FIG. 9 is a perspective view showing a state where the separator and the membrane electrode assembly of the polymer electrolyte fuel cell shown in FIG. 8 are separated from each other. It is a perspective view which shows the state which separated the separator and membrane electrode assembly of the polymer electrolyte fuel cell shown by FIG. 8 from the direction different from FIG. It is a top view for demonstrating the other example of the polymer electrolyte fuel cell using the separator of this invention. It is a longitudinal cross-sectional view in the AA line of the polymer electrolyte fuel cell shown by FIG. It is a figure for demonstrating the membrane electrode assembly which comprises the polymer electrolyte fuel cell shown by FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Separator]
FIG. 1 is a partial cross-sectional view showing an embodiment of a separator for a fuel cell of the present invention, and FIG. 2 is an enlarged cross-sectional view of a portion surrounded by a circle of the separator for a fuel cell shown in FIG. is there. 1 and 2, the separator 1 of the present invention includes a metal substrate 2, grooves 3 formed on both surfaces of the metal substrate 2, and the surface of the metal substrate 2 including the inner wall surfaces of these grooves 3. And a resin layer 5 formed by electrodeposition so as to cover the rough surface 2a of the metal substrate 2. Further, metal particles 4 are interposed between the rough surface 2a of the metal base 2 and the resin layer 5, and the resin layer 5 contains a conductive material.
When the separator 1 is incorporated in a fuel cell, one of the groove portions 3 of the metal substrate 2 becomes a fuel gas supply groove portion for supplying fuel gas to an adjacent unit cell, and the other is adjacent to another adjacent one. It becomes an oxidant gas supply groove for supplying an oxidant gas to the unit cell. Further, one of the groove portions 3 may be either a fuel gas supply groove portion or an oxidant gas supply groove portion, and the other may be a cooling water groove. Further, the groove 3 may be provided only on one surface of the metal base 2. The shape of the groove 3 is not particularly limited, and may be a meandering continuous shape, a comb shape, or the like, and the depth, width, and cross-sectional shape are not particularly limited. Further, the shape of the groove 3 may be different between the front and back of the metal base 2.

3 is a partial cross-sectional view showing another embodiment of the separator for a fuel cell of the present invention, and FIG. 4 is an enlarged cross-sectional view of a portion surrounded by a circle of the separator for a fuel cell shown in FIG. It is. 3 and 4, the separator 11 according to the present invention includes a metal substrate 12, a plurality of through holes 13 formed in the metal substrate 12, and a metal substrate 12 including inner wall surfaces of these through holes 13. And a resin layer 15 formed by electrodeposition so as to cover the rough surface 12a of the metal base 12. Further, metal particles 14 are interposed between the rough surface 12a of the metal base 12 and the resin layer 15, and the resin layer 15 contains a conductive material.
The through hole 13 of the metal base 12 serves as a flow path for supplying fuel gas or oxidant gas to the unit cell when the separator 11 is incorporated into the fuel cell. There is no restriction | limiting in particular in the magnitude | size, the number of such a through-hole 13, and arrangement | positioning density.
The materials of the metal substrates 2 and 12 constituting the separators 1 and 11 of the present invention are pure aluminum (1000 series) and aluminum alloy. Examples of the aluminum alloy include 2000 series, 5000 series, 6000 series, and 7000 series of aluminum.

The rough surfaces 2a and 12a of the metal substrates 2 and 12 have an average roughness Ra in the range of 1.5 to 10 μm, preferably 2 to 5 μm. When the average roughness Ra of the rough surfaces 2a and 12a is less than 1.5 μm, the adhesion between the rough surfaces 2a and 12a and the resin layers 5 and 15 may be insufficient, and the average roughness Ra is If it exceeds 10 μm, pinholes may occur in the resin layers 5 and 15, which is not preferable.
The average roughness Ra of the rough surfaces 2a and 12a is measured by VertScan 2.0 manufactured by Ryoka System.

The metal particles 4 and 14 interposed between the metal bases 2 and 12 (rough surfaces 2a and 12a) and the resin layers 5 and 15 are any one or two of zinc, tin, iron, nickel and copper. The above metal particles. Such metal particles 4 and 14 serve to improve the adhesion between the rough surfaces 2a and 12a and the resin layers 5 and 15, and have an average particle diameter of 5 to 500 nm, preferably 10 to 100 nm. , and the presence density of 2 10000000-25 ten million / mm ^2, preferably in the range of 4 10000000-10 ten million / mm ^2. When the average particle diameter of the metal particles 4 and 14 is less than 5 nm, the effect of improving the adhesion between the rough surfaces 2a and 12a and the resin layers 5 and 15 may be insufficient, and the average particle diameter may be 500 nm. When exceeding, the adhesiveness of the metal base materials 2 and 12 and the resin layers 5 and 15 will worsen, and is not preferable. Further, when the density of the metal particles 4 and 14 is less than 20 million / mm ² , the effect of improving the adhesion between the rough surfaces 2a and 12a and the resin layers 5 and 15 may be insufficient. If it exceeds 250,000,000 / mm ² , the adhesion between the metal substrates 2 and 12 and the resin layers 5 and 15 is unfavorable.
In addition, the average particle diameter of the metal particles 4 and 14 is measured with a transmission electron microscope HF-3300 manufactured by Hitachi High-Tech, and the existence density is calculated from image data photographed with a transmission electron microscope HF-3300 manufactured by Hitachi High-Tech.

The resin layers 5 and 15 constituting the separators 1 and 11 are conductive and provide corrosion resistance to the metal bases 2 and 12. The resin layers 5 and 15 are formed by electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in various anionic or cationic synthetic polymer resins having electrodeposition properties, and then cured. Can be formed.
Examples of the anionic synthetic polymer resin include acrylic resin, polyester resin, maleated oil resin, polybutadiene resin, epoxy resin, polyamide resin, polyimide resin, etc., and these can be used alone or as a mixture of any combination. Can be used. Moreover, you may use together said crosslinking | crosslinked resin, such as anionic synthetic polymer resin and a melamine resin, a phenol resin, and a urethane resin. On the other hand, examples of the cationic synthetic polymer resin include acrylic resin, epoxy resin, urethane resin, polybutadiene resin, polyamide resin, polyimide resin, and the like. These can be used alone or as a mixture of any combination. Can do. Moreover, you may use together said cationic synthetic polymer resin and crosslinkable resin, such as a polyester resin and a urethane resin.
Further, in order to impart tackiness to the above-described synthetic polymer resin having electrodeposition properties, a tackifier resin such as rosin, terpene, and petroleum resin may be added as necessary.

Such an electrodepositable synthetic polymer resin is subjected to electrodeposition in a state where it is neutralized with an alkaline or acidic substance and solubilized in water, or in an aqueous dispersion state. That is, the anionic synthetic polymer resin is neutralized with amines such as trimethylamine, diethylamine, dimethylethanolamine and diisopropanolamine, and inorganic alkalis such as ammonia and caustic potash. The cationic synthetic polymer resin is neutralized with an acid such as formic acid, acetic acid, propionic acid, or lactic acid. The neutralized water-soluble polymer resin is used in a state of being diluted in water as a water-dispersed type or a dissolved type.
The thickness of the resin layers 5 and 15 formed by electrodeposition can be in the range of 2 to 100 μm, preferably 5 to 30 μm. If the thickness of the resin layers 5 and 15 is less than 2 μm, good corrosion resistance may not be ensured due to the occurrence of pinholes, etc. If the thickness exceeds 100 μm, the occurrence of cracks after drying and solidification, etc. Problems such as reduction and high cost occur, which is not preferable.

Examples of the conductive material contained in the resin layers 5 and 15 include carbon materials such as carbon particles, carbon nanotubes, carbon nanofibers, and carbon nanohorns, and corrosion-resistant metals. If it is obtained, it is not limited to these conductive materials. In particular, fine fibrous carbon materials such as carbon nanotubes, carbon nanofibers, and carbon nanohorns are suitable for imparting conductivity to the resin layers 5 and 15. The content of the conductive material in the resin layers 5 and 15 can be appropriately set according to the conductivity required for the resin layers 5 and 15, and can be set in the range of 10 to 90% by weight, for example.
The above-described embodiments of the separator of the present invention are examples, and the present invention is not limited to these embodiments. For example, as shown in FIG. 5, a base plating layer 6 may be provided between the metal substrate 2 and the metal particles 4 and the resin layer 5. In this case, the underlying plating layer 6 can be any one of nickel, tin, zinc, copper, silver, cobalt, or two or more plating layers. In the case of two or more kinds, a multilayer base plating layer 6 may be formed, or the base plating layer 6 may be an alloy plating layer. In the present invention, the average roughness Ra of the rough surface 2a is 1.5 to 10 μm even when the base plating layer 6 is provided between the metal substrate 2 and the metal particles 4 and the resin layer 5 as described above. The thickness is preferably in the range of 2 to 5 μm. Also in the separator 11 described above, a base plating layer may be provided between the metal substrate 12 and the metal particles 14 and the resin layer 15.

[Manufacturing method of separator]
Next, the manufacturing method of the separator for fuel cells of this invention is demonstrated.
FIG. 6 is a process diagram for explaining the manufacturing method of the present invention using the separator 1 shown in FIGS. 1 and 2 as an example. In the present invention, resists 8 and 8 are formed in a desired pattern on both sides of a metal plate 2 'made of aluminum or aluminum alloy by photolithography, and the metal plate 2' is etched from both sides using the resists 8 and 8 as a mask. Grooves 3 and 3 are formed (FIG. 6A). Thereafter, the resists 8 and 8 are peeled off to obtain the metal substrate 2 (FIG. 6B).
Next, a roughening treatment is performed on both surfaces of the metal base 2 to form a rough surface 2a having an average roughness Ra in the range of 1.5 to 10 μm, preferably 2 to 5 μm (FIG. 6C )). When the average roughness Ra of the rough surface 2a is less than 1.5 μm, the adhesion between the resin layer 5 and the rough surface 2a to be formed in the subsequent electrodeposition step may be insufficient, and the average roughness When Ra exceeds 10 μm, the followability to the rough surface 2 a is deteriorated in the subsequent electrodeposition step, and pinholes are easily generated in the formed resin layer 5, which is not preferable. This roughening treatment is performed by using a metal-based treatment liquid containing any one or more of zinc, tin, iron, nickel and copper, or a metal salt such as a hydrochloride or sulfate thereof. This can be done by contacting the material 2. The contact between the treatment liquid and the metal substrate 2 can be performed by any method such as an immersion method, a spray method, and a coating method, for example.

  As the treatment liquid, for example, a treatment liquid having a pH in the acidic region can be used. Such a treatment liquid contains, for example, hydrochloric acid in the range of 0.1 to 5.0 mol / L, preferably 0.5 to 3.0 mol / L, and the above metal or metal salt is 0.01 It may be contained in the range of -1.0 mol / L, preferably 0.1-0.5 mol / L. When the hydrochloric acid concentration is less than 0.1 mol / L, the metal substrate 2 is insufficiently roughened, and when it exceeds 5.0 mol / L, the metal or metal salt contained is roughened as particles. It becomes difficult to deposit on the surface of 2a, which is not preferable. In addition, when the concentration of the metal or metal salt is less than 0.01 mol / L, the average particle diameter and abundance density of the metal particles deposited on the surface of the rough surface 2a as particles are within the specified range in the separator of the present invention. May not be reachable. Moreover, when the density | concentration of a metal or a metal salt exceeds 1.0 mol / L, there exists a possibility that the average roughness Ra of the rough surface 2a may remove | deviate from the range of 1.5-10 micrometers, and is unpreferable.

Moreover, as said process liquid, the process liquid whose pH is an alkaline region, for example, Preferably pH is 8.5 or more can be used. Such a treatment liquid contains, for example, a chelating agent in the range of 0.01 to 1.0 mol / L, preferably 0.1 to 0.5 mol / L, and the above metal or metal salt is 0.1%. It may be contained in a range of 01 to 1.0 mol / L, preferably 0.1 to 0.5 mol / L. Examples of the chelating agent include glycine, ethylenediaminetetraacetic acid (EDTA), and citric acid. The chelating agent concentration depends on the concentration of the metal or metal salt in the treatment liquid, and if it is less than 0.01 mol / L, the contained metal or metal salt precipitates as hydroxide instead of metal particles. Sometimes. On the other hand, even if the chelating agent concentration exceeds 1.0 mol / L, the effect of the chelating agent is not exhibited. In addition, when the concentration of the metal or metal salt is less than 0.01 mol / L, the average particle diameter and abundance density of the metal particles deposited on the surface of the rough surface 2a as particles are within the specified range in the separator of the present invention. May not be reachable. Moreover, when the density | concentration of a metal or a metal salt exceeds 1.0 mol / L, there exists a possibility that the average roughness Ra of the rough surface 2a may remove | deviate from the range of 1.5-10 micrometers, and is unpreferable.
The temperature of the treatment liquid in the roughening treatment of the metal substrate 2 can be, for example, 30 to 80 ° C., preferably 40 to 60 ° C., and the contact time between the metal substrate 2 and the treatment liquid. Can be, for example, in the range of 0.5 to 10 minutes. When the temperature of the treatment liquid is less than 30 ° C., the surface roughening treatment speed is slow and the productivity is lowered, and when it exceeds 80 ° C., the dissolution of the metal substrate 2 may proceed. Moreover, when the contact time is less than 0.5 minutes, the roughening of the metal substrate 2 becomes insufficient, or the contained metal or metal salt is deposited on the surface of the rough surface 2a as metal particles. When it exceeds 10 minutes, the metal particles are abnormally precipitated, and the average particle diameter and density of the metal particles may be out of the specified range in the separator of the present invention, which is not preferable.

Next, electrodeposition is performed on the rough surface 2a of the metal substrate 2 by electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in various anionic or cationic synthetic polymer resins having electrodeposition properties. A film is formed, and then a thermosetting treatment is performed to form the resin layer 5 (FIG. 6D). Thereby, the separator 1 of this invention is obtained.
The various materials described above can be used as various anionic and cationic synthetic polymer resins and conductive materials for preparing the electrodeposition liquid. In the thermosetting treatment, conditions can be appropriately set according to the synthetic polymer resin to be used, and for example, the heating temperature can be set in the range of 180 to 240 ° C.
In the formation of the resin layer 5 by such electrodeposition, the metal particles deposited on the rough surface 2a by the above roughening treatment serve as a reaction initiator, and the electrodeposition is performed. The rough surface 2 a functions as an anchor for the resin layer 5. As a result, the metal substrate 2 and the resin layer 5 are firmly adhered to each other, and have good conductivity and high corrosion resistance.

FIG. 7 is a process diagram for explaining the separator manufacturing method of the present invention, taking the separator 11 shown in FIGS. 3 and 4 as an example. In the present invention, resists 18 and 18 having a plurality of openings are formed by photolithography on both surfaces of a metal plate 12 'made of aluminum or an aluminum alloy, and the metal plate 12' is formed from both sides using the resists 18 and 18 as a mask. A plurality of through holes 13 are formed by etching (FIG. 7A). The plurality of openings of the resists 18 and 18 are positioned so as to face each other through the metal plate 12 '. Thereafter, the resists 18 and 18 are peeled off to obtain the metal substrate 12 (FIG. 7B).
The through-hole 13 can be formed by a sandblasting method, a laser processing method, a drilling method, or the like in addition to the above-described etching method.
Next, the metal substrate 12 including the inner wall surface of the through hole 13 is roughened to form a rough surface 12a having an average roughness Ra in the range of 1.5 to 10 μm, preferably 2 to 5 μm. (FIG. 7C). This roughening treatment can be the same as in the above-described embodiment of the manufacturing method.

Next, electrodeposition is performed on the rough surface 12a of the metal substrate 12 by electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in various anionic or cationic synthetic polymer resins having electrodeposition properties. A film is formed, and then a thermosetting treatment is performed to form the resin layer 15 (FIG. 7D). Thereby, the separator 11 of this invention is obtained.
The various materials described above can be used as various anionic and cationic synthetic polymer resins and conductive materials for preparing the electrodeposition liquid. In the thermosetting treatment, conditions can be appropriately set according to the synthetic polymer resin to be used, and for example, the heating temperature can be set in the range of 180 to 240 ° C.
In the formation of the resin layer 15 by such electrodeposition, the metal particles deposited on the rough surface 12a by the roughening treatment serve as a reaction initiator, and the electrodeposition is performed. The rough surface 12a acts as an anchor with respect to the resin layer 15, whereby the metal substrate 12 and the resin layer 15 are firmly adhered to each other, and has good conductivity and high corrosion resistance.

In such a separator manufacturing method of the present invention, the metal bases 2 and 12 and the resin layers 5 and 15 are firmly adhered to each other, and it is possible to manufacture a separator having excellent corrosion resistance and conductivity. Compared with a conventional separator manufacturing method in which a multi-layered corrosion-resistant underlayer is formed on a substrate, the process is simplified and the manufacturing cost can be reduced.
The embodiments of the separator manufacturing method of the present invention described above are exemplifications, and the present invention is not limited to these embodiments. For example, as shown in FIG. 5, when manufacturing a separator having a metal base 2 and a base plating layer 6 between the metal particles 4 and the resin layer 5, nickel is formed on the rough surface 2 a of the metal base 2. Any one or two or more plating layers of tin, zinc, copper, silver, cobalt, etc., are formed as the base plating layer 6. In the case of two or more kinds, a multilayer base plating layer 6 may be formed, or the base plating layer 6 may be an alloy plating layer. In the formation of the base plating layer 6, since the metal particles deposited on the rough surface 2 a by the roughening treatment serve as a reaction initiator and are plated, the metal substrate 2 and the base plating layer 6 are separated from each other. It will be firmly adhered. Then, the rough surface 2a on which the base plating layer 6 is formed acts as an anchor for the resin layer 5, whereby the metal substrate 2, the base plating layer 6 and the resin layer 5 are firmly adhered to each other. It has high conductivity and high corrosion resistance. In the present invention, when the base plating layer 6 is formed in this way, the average roughness Ra of the rough surface 2a on which the base plating layer 6 is formed is in the range of 1.5 to 10 μm, preferably 2 to 5 μm. Like that.

[Example of fuel cell using separator of the present invention]
Here, an example of a polymer electrolyte fuel cell using the separator of the present invention will be described with reference to FIGS. FIG. 8 is a partial configuration diagram for explaining the structure of a polymer electrolyte fuel cell, and FIG. 9 is a diagram for explaining a membrane electrode assembly constituting the polymer electrolyte fuel cell. FIG. 10 and FIG. 11 are perspective views showing the state in which the separator of the polymer electrolyte fuel cell and the membrane electrode assembly are separated from different directions.
8 to 11, the polymer electrolyte fuel cell 21 has a stack structure in which a plurality of unit cells each including a membrane electrode assembly (MEA) 31 and a separator 41 are stacked. .
As shown in FIG. 9, the MEA 31 includes a fuel electrode (hydrogen electrode) 35 including a catalyst layer 33 and a gas diffusion layer (GDL) 34 disposed on one surface of the polymer electrolyte membrane 32. And an air electrode (oxygen electrode) 38 composed of a catalyst layer 36 and a gas diffusion layer (GDL) 37 disposed on the other surface of the polymer electrolyte membrane 32.

  The separator 41 has a fuel gas supply groove 43a on one surface, a separator 41A having an oxidant gas supply groove 44a on the other surface, a fuel gas supply groove 43a on one surface, and the other surface. The separator 41B has a cooling water groove 44b on the surface, and the separator 41C has a cooling water groove 43b on one surface and an oxidant gas supply groove 44a on the other surface. Such separators 41A, 41B, and 41C are separators of the present invention, and resin layers are formed on both surfaces thereof as shown in FIGS. 1 and 2, but they are omitted in the illustrated example.

  Two fuel gas supply holes 45a and 45b, two oxidant gas supply holes 46a and 46b, and two cooling water supplies are provided at predetermined positions of the separators 41A, 41B and 41C and the polymer electrolyte membrane 32. Holes 47a and 47b are formed as through holes. Then, the air electrode (oxygen electrode) 38 of the MEA 31 is in contact with the surface of the separator 41A where the oxidizing gas supply groove 44a is formed, and the surface of the separator 41B where the fuel gas supply groove 43a is formed, The fuel electrode (hydrogen electrode) 35 of the MEA 31 abuts, and the surface of the separator 41B on which the cooling water groove 44b is formed and the surface of the separator 41C on which the cooling water groove 43b is formed abut. The separators 41A, 41B, and 41C and the MEA 31 that is a unit cell are stacked, and the polymer electrolyte fuel cell 21 is configured by repeating this process. In the stacked state, the two fuel gas supply holes 45a and 45b form fuel gas supply passages penetrating in the stacking direction, and the two oxidant gas supply holes 46a and 46b are respectively formed. An oxidant gas supply path that penetrates the laminating method is formed, and the two cooling water supply holes 47a and 47b each form a cooling water supply path that penetrates in the laminating direction.

  Another example of the polymer electrolyte fuel cell using the separator of the present invention will be described with reference to FIGS. FIG. 12 is a plan view for explaining the structure of the polymer electrolyte fuel cell, and FIG. 13 is a longitudinal sectional view taken along line AA of the polymer electrolyte fuel cell shown in FIG. FIG. 14 is a view for explaining a membrane electrode assembly constituting a polymer electrolyte fuel cell.

As shown in FIGS. 12 and 13, the polymer electrolyte fuel cell 51 includes a plurality of unit cells 52 each including a membrane-electrode assembly (MEA) 61 and separators 71 </ b> A and 71 </ b> B in a planar shape. This is a polymer electrolyte fuel cell that is arranged and electrically connected in series to extract voltages corresponding to the number of unit cells (four in FIG. 9). Further, around each unit cell 52, an insulating portion 55 having substantially the same thickness as this is provided, and the whole is flat. That is, the unit cell 52 and the insulating part 55 are provided in a planar shape by fitting the unit cell 52 into the cut-out part of the flat insulating part 55.
The polymer electrolyte fuel cell 51 is provided with a front and back connection part 57c for penetrating through the insulating part 55 located between adjacent unit cells of the insulating part 55 and connecting the front and back thereof. Then, the front / back connection portion 57c is connected to the separator 71A (for example, the fuel electrode side separator) of one adjacent unit cell via the connection wiring 57a, and the other adjacent one is connected via the connection wiring 57b. The unit cell is connected to a separator 71B (for example, an air electrode side separator). Thereby, adjacent unit cells are electrically connected in series. Wirings 75 and 76 are connected to the separator 71A of the unit cell 52 located at one end connected in series and the separator 71B of the unit cell 52 located at the other end.
In the illustrated example, the number of unit cells is four, but the number of unit cells is not limited.

The insulating part 55 insulates adjacent unit cells from each other except that they are connected by connection parts 57 (connection wirings 57a and 57b and front and back connection parts 57c). The material of the insulating part 55 is not particularly limited as long as it is excellent in terms of processability and durability. For example, glass epoxy, polyimide resin, or the like is used. The insulating portion 55 may be made of only an insulating material or may include a part of a conductive material.
As the front and back connection part 57c of the connection part 57, either a through-hole connection part or a filling via connection part or a bump connection part is provided in the insulating part 55 located between adjacent unit cells. it can. These front and back connection portions 57c can be formed as an application of conventional wiring board technology.
Further, as shown in FIG. 14, the MEA 61 includes a fuel electrode (hydrogen electrode) composed of a catalyst layer 63 and a gas diffusion layer (GDL) 64 disposed on one surface of the polymer electrolyte membrane 62. ) 65, and an air electrode (oxygen electrode) 68 including a catalyst layer 66 and a gas diffusion layer (GDL) 67 disposed on the other surface of the polymer electrolyte membrane 62.
Separator 71A, 71B is a separator of the present invention as shown in FIG. 3 and FIG. 4, and has a conductive resin layer on a metal substrate having a plurality of through holes.

Next, the present invention will be described in more detail by showing specific examples.
[Example 1]
An aluminum alloy (A5052P) having a size of 80 mm × 80 mm and a thickness of 0.8 mm was prepared as a metal plate material, and the surface was degreased.
Next, a dry film resist (manufactured by Nichigo Morton Co., Ltd.) is laminated on both surfaces of the aluminum alloy to form a 35 μm-thick photosensitive resist layer, and then exposed through a photomask for forming a groove ( A resist was formed by irradiating with a 5 kW mercury lamp for 15 seconds) and developing (spraying a 2% aqueous sodium hydrogen carbonate solution at 30 ° C.).
Next, a ferric chloride aqueous solution heated to 45 ° C. was sprayed from both sides of the aluminum alloy through the resist, and half-etched to a predetermined depth. Thereafter, the resist was peeled off with a 5% aqueous sodium hydrogen carbonate solution at 50 ° C. and subjected to a cleaning treatment. As a result, a metal base material having a substantially semicircular cross section with a width of 1 mm and a depth of 0.3 mm, and a groove portion with a runout width of 50 mm and a meandering length of 1300 mm meandering on both sides was obtained.

Next, the metal film was subjected to an oxide film removal treatment using an aqueous nitric acid solution. Next, the metal base material was immersed in a treatment solution A in which hydrochloric acid was dissolved in pure water at a concentration of 1.2 mol / L and copper sulfate pentahydrate at a concentration of 0.04 mol / L (50 ° C., 1 minute) to roughen. Surface treatment was performed, and after lifting, it was washed with water and dried. The average roughness Ra of the rough surface of the metal substrate subjected to such surface roughening treatment was measured using VertScan 2.0 manufactured by Ryoka System Co., Ltd., and the results are shown in Table 1 below. In addition, it was 0.3 micrometer when average roughness Ra of the metal base material before performing a roughening process was measured similarly to the above.
Moreover, as a result of measuring the average particle diameter of the copper particle which exists in a rough surface using the Hitachi High-Tech transmission electron microscope HF-3300, it is about 12 nm, and the existence density of a copper particle is a Hitachi High-Tech transmission electron microscope HF. As a result of calculation from image data photographed at −3300, it was about 60 million pieces / mm ² .
Subsequently, carbon black (Vulcan XC-72 manufactured by Cabot Co., Ltd.) as a conductive material was added to and dispersed in the epoxy electrodeposition liquid by 75% by weight with respect to the resin solid content to obtain an electrodeposition liquid. The electrodeposition liquid was stirred while being kept at 25 ° C., and the metal substrate was immersed in the electrodeposition solution, electrodeposition was performed at a gap of 40 mm and a voltage of 50 V for 1 minute, and the pulled metal substrate was washed with pure water. Then, it dried with hot air (150 degreeC, 3 minutes) with the dryer, and also performed the thermosetting process for 1 hour at 180 degreeC in nitrogen atmosphere. Thereby, a resin layer having a thickness of 15 μm was formed, and a separator was obtained.

The epoxy electrodeposition solution used was prepared as follows.
First, 1000 parts by weight of diglycidyl ether of bisphenol A (epoxy equivalent 910) was dissolved in 463 parts by weight of ethylene glycol monoethyl ether while maintaining the temperature at 70 ° C. with stirring, and further 80.3 parts by weight of diethylamine was added to 100 parts. An amine epoxy adduct (A) was prepared by reacting at 2 ° C. for 2 hours.
Coronate L (manufactured by Nippon Polyurethane Co., Ltd. diisocyanate: NCO 13% non-volatile content 75% by weight) 875 parts by weight dibutyltin laurate 0.05 parts by weight and heated to 50 ° C., to this, 390 weights of 2-ethylhexanol After that, the mixture was reacted at 120 ° C. for 90 minutes. A component (B) obtained by diluting the obtained reaction product with 130 parts by weight of ethylene glycol monoethyl ether was obtained.
Next, the mixture consisting of 1000 parts by weight of the above-described amine epoxy adduct (A) and 400 parts by weight of component (B) is neutralized with 30 parts by weight of glacial acetic acid, and then diluted with 570 parts by weight of deionized water. A resin A having a nonvolatile content of 50% by weight was prepared. An epoxy electrodeposition solution was prepared by blending 200.2 parts by weight of this resin A (resin component 86.3 volumes), 583.3 parts by weight of deionized water, and 2.4 parts by weight of dibutyltin laurate.

About the produced said separator, the electrical resistance of front-back conduction was measured by the following method, and the result was shown in following Table 1.
(Measurement method of electrical resistance)
Separator gas diffusion layer (TGP-H-060 190μm thickness manufactured by Toray Industries, Inc.)
Between the two electrodes, and further sandwiched between 5 mm thick copper-plated copper electrodes (pressure: 20 kgf / cm ² ) to measure the resistance between the electrodes.

Further, the above-mentioned separator was subjected to a corrosion resistance test under the following conditions, and the evaluation results are shown in Table 1 below.
(Conditions for corrosion resistance test)
After immersing in 1 molar sulfuric acid aqueous solution (70 ° C) for 100 hours, pull up and observe the generation of aluminum hydroxide.
Evaluation criteria:
○: No occurrence of aluminum hydroxide and good corrosion resistance
×: Aluminum hydroxide is generated and corrosion resistance is insufficient

Furthermore, the above-mentioned separator was subjected to a resin layer adhesion test under the following conditions, and the evaluation results are shown in Table 1 below.
(Adhesion test conditions)
Attach the stud pin with epoxy adhesive vertically to the separator.
Using a Group-made Romulus, the tensile adhesion strength was measured, and the separator where the stud pin was peeled off was observed.
Evaluation criteria:
○… Cohesion failure occurs inside the resin layer, and adhesion between the resin layer and the metal substrate is maintained
Has good adhesion
X: Peeling occurs at the interface between the resin layer and the metal substrate, and the metal substrate is exposed,
Adhesion is insufficient

[Example 2]
A separator was produced in the same manner as in Example 1 except that a base plating layer (thickness: 3 μm) was formed on the rough surface of the metal substrate under the following conditions before forming the resin layer by electrodeposition.
(Under plating conditions)
・ Use bath: Nickel chloride plating bath
・ PH: 1.3
・ Current density: 6A / dm ²
・ Liquid temperature: 23 ℃
The average roughness Ra of the rough surface of the metal substrate after forming the base plating layer was measured by the same method as in Example 1, and the results are shown in Table 1 below.
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Example 3]
The treatment liquid used for the roughening treatment was the same as in Example 1 except that the treatment liquid B in which hydrochloric acid was dissolved in pure water at a concentration of 2 mol / L and tin sulfate was 0.15 mol / L was used. Thus, a separator was produced.
The average roughness Ra of the rough surface of the metal substrate subjected to the roughening treatment was measured in the same manner as in Example 1, and the results are shown in Table 1 below. Moreover, as a result of measuring the average particle diameter of the tin particles existing on the rough surface in the same manner as in Example 1, it was about 15 nm. As a result of measuring the existing density of tin particles in the same manner as in Example 1, about 40 million particles were obtained. / Mm ² .
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Example 4]
A separator was produced in the same manner as in Example 3 except that a base plating layer (thickness 3 μm) was formed on the rough surface of the metal base material under the following conditions before forming the resin layer by electrodeposition.
(Under plating conditions)
・ Use bath: Nickel chloride plating bath
・ PH: 1.3
・ Current density: 6A / dm ²
・ Liquid temperature: 23 ℃
The average roughness Ra of the rough surface of the metal substrate after forming the base plating layer was measured in the same manner as in Example 1, and the results are shown in Table 1 below.
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Example 5]
A separator was produced in the same manner as in Example 1 except that the time for immersing the metal substrate in the treatment liquid A at 50 ° C. was 0.5 minutes and the roughening treatment conditions were weakened.
The average roughness Ra of the rough surface of the metal substrate subjected to the roughening treatment was measured in the same manner as in Example 1, and the results are shown in Table 1 below. Moreover, as a result of measuring the average particle diameter of the copper particles existing on the rough surface in the same manner as in Example 1, it was about 12 nm, and as a result of measuring the existence density of the copper particles in the same manner as in Example 1, about 20 million particles were obtained. / Mm ² .
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Example 6]
A separator was produced in the same manner as in Example 1 except that the time for immersing the metal substrate in the treatment liquid A at 50 ° C. was 10 minutes and the conditions for the roughening treatment were increased.
The average roughness Ra of the rough surface of the metal substrate subjected to the roughening treatment was measured in the same manner as in Example 1, and the results are shown in Table 1 below. Moreover, as a result of measuring the average particle diameter of the copper particle which exists in a rough surface similarly to Example 1, it is about 12 nm, As a result of measuring the existence density of a copper particle similarly to Example 1, about 240 million pieces are obtained. / Mm ² .
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Example 7]
As a treatment solution used for the roughening treatment, copper sulfate is dissolved in pure water at a concentration of 0.1 mol / L and nickel sulfate is added at a concentration of 0.4 mol / L, and glycine is added at 0.15 mol / L. A separator was prepared in the same manner as in Example 1 except that the treatment liquid C having a pH adjusted to 9.0 with sodium hydroxide was used, and the immersion in the roughening treatment was 70 ° C. for 10 minutes. .
The average roughness Ra of the rough surface of the metal substrate subjected to the roughening treatment was measured in the same manner as in Example 1, and the results are shown in Table 1 below. Moreover, as a result of measuring the average particle diameter of the copper particle and nickel particle which existed in the rough surface like Example 1, the copper particle was about 11 nm and the nickel particle was about 18 nm. Further, the existence density of the copper particles and the nickel particles was measured in the same manner as in Example 1. As a result, the copper particles were about 50 million / mm ² and the nickel particles were about 80 million / mm ² .
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Comparative Example 1]
In the same manner as in Example 1, a metal substrate having groove portions on both sides was prepared, pretreated with an aqueous nitric acid solution, and washed with water.
Next, zinc replacement treatment was performed on the above metal base material under the following conditions to form a zinc alloy layer (thickness 0.05 μm) on the metal base material including the groove.
(Conditions for zinc replacement treatment)
・ Use bath: Zincate bath (Mertex Co., Ltd. ALMON EN)
・ Liquid temperature: 30 ℃
・ Processing time: 20 seconds

Next, a copper plating layer (thickness 1 μm), a nickel plating layer (thickness 5 μm), and a gold plating layer (thickness 0.05 μm) are sequentially laminated on the zinc alloy layer under the following electroplating conditions, and zinc / copper / nickel A corrosion-resistant underlayer having a four-layer structure of / gold was formed on a metal substrate including a groove.
(Copper electroplating conditions)
-Bath used: Copper cyanide bath-pH: 10.5
・ Current density: 2A / dm ²
・ Liquid temperature: 40 ℃
(Nickel electroplating conditions)
-Bath used: Nickel chloride plating bath-pH: 1.3
・ Current density: 6A / dm ²
・ Liquid temperature: 23 ℃
(Gold electroplating conditions)
-Bath used: alkaline high-purity gold plating bath-pH: 12
・ Current density: 0.4 A / dm ²
・ Liquid temperature: 60 ℃

Next, in the same manner as in Example 1, a resin layer having a thickness of 15 μm was formed on the corrosion-resistant undercoat layer to obtain a separator.
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Comparative Example 2]
A separator was prepared by forming a resin layer on the metal substrate in the same manner as in Example 1 except that the roughening treatment was not performed on the metal substrate.
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Comparative Example 3]
A separator was prepared by forming a base plating layer and a resin layer on the metal substrate in the same manner as in Example 2 except that the roughening treatment was not performed on the metal substrate.
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Comparative Example 4]
A separator was produced in the same manner as in Example 1 except that the time for immersing the metal substrate in the treatment liquid A at 50 ° C. was set to 0.3 minutes, and the roughening treatment conditions were weakened.
The average roughness Ra of the rough surface of the metal substrate subjected to the roughening treatment was measured in the same manner as in Example 1, and the results are shown in Table 1 below. Moreover, as a result of measuring the average particle diameter of the copper particles existing on the rough surface in the same manner as in Example 1, it was about 12 nm. As a result of measuring the existence density of the copper particles in the same manner as in Example 1, about 2 million particles / It was mm ^2.
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

[Comparative Example 5]
A separator was produced in the same manner as in Example 1 except that the time for immersing the metal substrate in the treatment liquid A at 50 ° C. was 20 minutes and the conditions for the roughening treatment were strengthened.
The average roughness Ra of the rough surface of the metal substrate subjected to the roughening treatment was measured in the same manner as in Example 1, and the results are shown in Table 1 below. Moreover, as a result of measuring the average particle diameter of the copper particles existing on the rough surface in the same manner as in Example 1, it was about 12 nm, and as a result of measuring the existence density of the copper particles in the same manner as in Example 1, about 300 million particles were obtained. / Mm ² .
About the produced said separator, the electrical resistance of front-back conduction was measured by the method similar to Example 1, and the result was shown in following Table 1.
Moreover, about said separator, the corrosion resistance test was done on the conditions similar to Example 1, and the evaluation result was shown in following Table 1. FIG.
Further, the above separator was subjected to a resin layer adhesion test under the same conditions as in Example 1, and the evaluation results are shown in Table 1 below.

As shown in Table 1, the separators of Examples 1 to 7 have good electrical conductivity with low electrical resistance on the front and back sides, excellent corrosion resistance, and good adhesion of the resin layer. It was confirmed that.
On the other hand, the separators of Comparative Examples 1 to 5 were inferior to the separators of Examples 1 to 7 in at least one of conductivity, corrosion resistance, and adhesion.

  The present invention can be applied to the manufacture of a fuel cell in which a plurality of unit cells each having an electrode disposed on both sides of a solid polymer electrolyte membrane are connected.

DESCRIPTION OF SYMBOLS 1,11 ... Separator 2,12 ... Metal base material 2a, 12a ... Rough surface 3 ... Groove 4,14 ... Metal particle 5,15 ... Resin layer 13 ... Through-hole 21, 51 ... Polymer electrolyte fuel cell 31,61 ... Membrane electrode assembly (MEA)
41A, 41B, 41C, 71A, 71B ... separator

Claims (12)

A metal base, a conductive resin layer formed by electrodeposition so as to cover the metal base, and metal particles interposed between the metal base and the resin layer, the metal base The material is aluminum or an aluminum alloy, the metal substrate surface covered with the resin layer has a rough surface with an average roughness Ra in the range of 1.5 to 10 μm, and the metal particles are tin. A separator for a fuel cell, wherein the resin layer contains one or more metal particles of iron, nickel and copper, and the resin layer contains a conductive material. The metal particles have an average particle size in the range of 5 to 500 nm and a density of 20 to 250,000,000 / mm. ² The separator for a fuel cell according to claim 1, wherein the separator is in the range of The separator for a fuel cell according to claim 1 or 2 , wherein the metal substrate has a groove on at least one surface. 3. The fuel cell separator according to claim 1, wherein the metal substrate has a plurality of through holes. 4. The fuel cell separator according to any one of claims 1 to 4 , wherein the conductive material is at least one of carbon particles, carbon nanotubes, carbon nanofibers, carbon nanohorns, and corrosion-resistant metals. The separator for a fuel cell according to any one of claims 1 to 5 , further comprising a base plating layer between the metal base material, the metal particles, and the resin layer.   A step of roughening a metal base material made of aluminum or an aluminum alloy, and the metal base material by electrodeposition using an electrodeposition liquid in which a conductive material is dispersed in a resin having electrodeposition properties Forming a resin layer by applying a thermosetting treatment, and in the roughening treatment, any one or two of zinc, tin, iron, nickel and copper are used. A process for producing a separator for a fuel cell, comprising contacting a treatment liquid containing the above metal or metal salt to form a rough surface having an average roughness Ra in a range of 1.5 to 10 μm. The method for producing a separator for a fuel cell according to claim 7 , wherein the treatment liquid has an acidic pH range. The treatment liquid contains hydrochloric acid in a range of 0.1 to 5.0 mol / L, and contains the metal or the metal salt in a range of 0.01 to 1.0 mol / L. The manufacturing method of the separator for fuel cells of Claim 8 . The method for producing a separator for a fuel cell according to claim 7 , wherein the treatment liquid has a pH in an alkaline region. The treatment liquid contains a chelating agent in a range of 0.01 to 1.0 mol / L, and contains the metal or the metal salt in a range of 0.01 to 1.0 mol / L. The method for producing a fuel cell separator according to claim 10 . Before the roughening treatment is applied, the method for manufacturing a fuel cell separator according to any one of claims 7 to 11, characterized in that performing the process of removing the oxide film to the metal substrate.

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