JP2017183164A - Manufacturing method for reinforcement type electrolyte membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce intensity gradient relaying on its direction in reinforcement type electrolyte membrane.SOLUTION: A manufacturing method for a reinforcement type electrolyte membrane comprises: (a) a step in which a first composite membrane in which a fist reinforcement layer base material is in contact with one face of a first electrolyte base material and a second composite membrane in which a second reinforcement base material is in contact with one face of a second electrolyte base material are bonded such that the first reinforcement layer base material and the second reinforcement layer base material are in contact with each other; and (b) a step in which the first reinforcement layer base material is impregnated with the first electrolyte base material in the first composite membrane and the second reinforcement layer base material is impregnated with the second electrolyte base bacterial in the second composite membrane. The first reinforcement layer base material and the second reinforcement layer base material respectively have maximum elastic modulus directions. The step (a) includes the step of bonding the first composite membrane and the second composite membrane such that the maximum elastic modulus direction of the first reinforcement layer base material and the maximum elastic modulus direction of the second reinforcement layer base material intersect each other.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing a reinforced electrolyte membrane.

  The electrolyte membrane used in the fuel cell changes greatly in size by repeatedly expanding or contracting according to the wet state inside the fuel cell. Further, by repeatedly generating and stopping the fuel cell, the electrolyte membrane may deteriorate and the strength may decrease. Therefore, a reinforced electrolyte membrane having a configuration in which a porous reinforcing layer is provided in parallel with the electrolyte membrane is known. By using a material that does not absorb moisture or absorb water, such as polytetrafluoroethylene (PTFE), as a reinforcing layer of the reinforced electrolyte membrane, the dimensional change due to expansion or contraction of the electrolyte membrane can be alleviated, and the dimensional stability and mechanical properties of the electrolyte membrane can be reduced. The strength can be improved. In the manufacturing process of a reinforced electrolyte membrane, when the strip member of the electrolyte membrane or the reinforcing layer is transported along the transport direction, the strip member is contracted and deformed in the width direction by applying a tensile stress in the transport direction. So-called neck-in may occur. When neck-in occurs, the strength of the band-shaped member decreases and the strength ratio between the transport direction and the width direction deviates from the desired value, thereby reducing the durability of the reinforced electrolyte membrane and the fuel cell using the same. There is a risk that. In Patent Document 1, as a method for manufacturing a reinforced electrolyte membrane, in order to suppress the occurrence of neck-in, a belt-like back sheet is disposed on the surface of a belt-like member of a reinforcing layer and conveyed, and the electrolyte membrane or reinforcement being conveyed is conveyed. Techniques for protecting the layers are disclosed.

JP 2014-229433 A

  Generally, in the manufacturing process of the reinforced electrolyte membrane, the band-shaped member that is the base of the reinforcing layer is stretched in the transport direction and the width direction, respectively. Due to the characteristics of the belt-like member that is the basis of the reinforcing layer, the strength increases in the extending direction. However, since the strength cannot be increased in a direction different from the extending direction, such as the transport direction and the width direction, a strength gradient depending on the direction can occur as the strength characteristic of the reinforced electrolyte membrane. When such a strength gradient occurs, damage such as tearing of the electrolyte membrane occurs in the direction of lower strength (generally different from the stretching direction) when a dimensional change of the electrolyte membrane occurs due to expansion or contraction. There is a problem that durability is lowered. Therefore, when the strength gradient in various directions is increased by reducing the strength gradient in the belt-shaped member conveyance control (stretching control), complicated conveyance control is required, so the manufacturing apparatus becomes expensive and the reinforced electrolyte membrane There is a problem that the manufacturing cost of the device increases. For this reason, there is a demand for a technique that can suppress an increase in the manufacturing cost of the reinforced electrolyte membrane while reducing the strength gradient depending on the direction in the reinforced electrolyte membrane.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

  (1) According to one embodiment of the present invention, a method for producing a reinforced electrolyte membrane is provided. This method of manufacturing a reinforced electrolyte membrane is a method of manufacturing a reinforced electrolyte membrane having a reinforced layer and a pair of electrolyte layers sandwiching the reinforced layer, wherein (a) a base material for one of the electrolyte layers. A first composite membrane in which a first reinforcing layer base material that is a base material of the reinforcing layer and is smaller in thickness than the reinforcing layer is in contact with one surface of one electrolyte base material; A second reinforcing layer base material that is a base material of the reinforcing layer and has a smaller thickness than the reinforcing layer is in contact with one surface of a second electrolyte base material that is a base material of the electrolyte layer. Bonding the composite film with the first reinforcing layer base material and the second reinforcing layer base material in contact with each other; (b) in the first composite film, the first electrolyte A base material is impregnated into the first reinforcing layer base material, and in the second composite film, the second electrolyte base material is replaced with the second reinforcing layer base material. The first reinforcing layer base material and the second reinforcing layer base material each have a maximum elastic modulus direction in which the tensile elastic modulus is larger than the other directions. And the step (a) includes the first composite so that the maximum elastic modulus direction of the first reinforcing layer base material and the maximum elastic modulus direction of the second reinforcing layer base material intersect each other. A step of bonding the film and the second composite film together.

  According to the method for manufacturing a reinforced electrolyte membrane of this embodiment, the first composite membrane and the second composite membrane are bonded together so that the first reinforcement layer substrate and the second reinforcement layer substrate are in contact with each other. In the step (a), since the maximum elastic modulus direction of the first reinforcing layer substrate and the maximum elastic modulus direction of the second reinforcing layer substrate are bonded to each other, the elastic modulus is maximized in the reinforcing layer. The direction can be suppressed from being limited to one direction, and the strength gradient depending on the direction in the reinforced electrolyte membrane can be reduced. In addition, since the strength gradient depending on the direction can be easily reduced by controlling the direction when the first reinforcing layer base material and the second reinforcing layer base material are bonded together, it is possible to manufacture the reinforced electrolyte membrane. Increase in cost can be suppressed.

  The present invention can be realized in various forms. For example, a membrane electrode assembly including a reinforced electrolyte membrane, a fuel cell including the membrane electrode assembly, a vehicle equipped with the fuel cell, a method of manufacturing a membrane electrode assembly, a method of manufacturing a fuel cell, and a method of manufacturing a vehicle It can also be realized in the form.

1 is a perspective view showing a reinforced electrolyte membrane manufactured by a method for manufacturing a reinforced electrolyte membrane as one embodiment of the present invention. FIG. 6 is a process diagram illustrating a method for manufacturing a reinforced electrolyte membrane 60. FIG. It is explanatory drawing which shows typically the 1st composite film 141 and the 2nd composite film 142 after execution of process P115. It is explanatory drawing which shows typically the 1st composite film and 2nd composite film after execution of process P120. It is explanatory drawing which shows typically the mode of the 1st composite film 41 and the 2nd composite film 42 at the time of execution of process P125. It is explanatory drawing which shows typically the reinforcement type electrolyte membrane precursor 50 after execution of process P130. It is explanatory drawing which shows the result of having measured the dimensional change rate of the sample 1 of 1st Example, and the sample 2 of a 1st comparative example. It is explanatory drawing which shows the result of having evaluated the durability of the reinforcement type electrolyte membrane using the sample 3 of 2nd Example, and the sample 4 of a comparative example.

A. Embodiment:
A1. Configuration of reinforced electrolyte membrane:
FIG. 1 is a perspective view showing a reinforced electrolyte membrane manufactured by a method for manufacturing a reinforced electrolyte membrane according to an embodiment of the present invention. The reinforced electrolyte membrane 60 has a configuration in which the reinforcing layer 20 and a pair of electrolyte layers (the first electrolyte layer 11 and the second electrolyte layer 12) sandwiching the reinforcing layer 20 are integrated. The reinforced electrolyte membrane 60 is used for, for example, a membrane electrode assembly of a fuel cell mounted on a vehicle. The reinforcing layer 20 is incorporated in the electrolyte membrane in order to suppress tearing and damage of the electrolyte membrane. The reinforcing layer 20 is formed by stretching polytetrafluoroethylene (PTFE) or the like. The reinforcing layer 20 is a porous body and has pores.

  The first electrolyte layer 11 is disposed so as to face one surface of the reinforcing layer 20. The second electrolyte layer 12 is disposed so as to face the other surface of the reinforcing layer 20. The first electrolyte layer 11 and the second electrolyte layer 12 are both fluorine-based ion exchange resin membranes that exhibit good proton conductivity. A part of the resin constituting the first electrolyte layer 11 and the second electrolyte layer 12 is impregnated into the pores of the reinforcement layer 20, whereby the reinforcement layer 20, the first electrolyte layer 11, and the second electrolyte layer are Are joined together and integrated.

A2. Manufacturing method of reinforced electrolyte membrane 60:
FIG. 2 is a process diagram showing a method for manufacturing the reinforced electrolyte membrane 60. First, various materials for manufacturing the reinforced electrolyte membrane 60 are prepared (process P105). As will be described later, the reinforced electrolyte membrane 60 is formed by bonding two composite membranes (a first composite membrane 41 and a second composite membrane 42 described later). In both of these two composite membranes, the base material of the reinforcing layer 20 (hereinafter also referred to as “reinforcing layer base material”) and the base material of the electrolyte layer (hereinafter also referred to as “electrolyte base material”) are bonded together. Have a configuration. Therefore, in step P105, a reinforcing layer base material and an electrolyte base material are prepared. The electrolyte substrate can be produced by an extrusion method. In addition, the thickness of the reinforcing layer base is smaller (thinner) than the thickness of the reinforcing layer 20 and is approximately ½. In the present embodiment, the reinforcing layer base material and the electrolyte base material are both prepared in a rolled state. And a reinforcement layer base material and an electrolyte base material are each set to the supply roller with which the manufacturing apparatus which is not shown in figure is equipped.

  The reinforcing layer base material is stretched in the width direction while being fed out from a supply roller (not shown) (process P110). In the present embodiment, the width direction is a direction orthogonal to the longitudinal direction of the reinforcing layer base material wound in a roll shape, in other words, a short direction, and a feeding direction (conveying direction) of the reinforcing layer base material. The directions are orthogonal. In a manufacturing apparatus (not shown), the end portion in the width direction of the reinforcing layer base material is transported downstream in the transport direction while being gripped by the transport roller, and the end portion in the width direction of the reinforcing layer base material is gripped by the widening roller. While expanding the reinforcing layer base material in the width direction. At this time, a load is not applied in the transport direction so that stretching in the transport direction is not performed. Therefore, a greater force is applied to the reinforcing layer base material in the width direction than in the transport direction. For this reason, in the reinforced layer base material after stretching, the tensile elastic modulus in the width direction of the film material is larger than the tensile elastic modulus in any other direction including the conveying direction of the film material. In the following description, the direction in which the magnitude of the tensile elastic modulus in the film material is larger than that in other directions is referred to as the maximum elastic modulus direction EMD. In the present embodiment, as described above, the elastic modulus maximum direction EMD coincides with the width direction. In addition, in this process P110, two reinforcement layer base materials are each extended | stretched for two composite films.

  The electrolyte base material is bonded to the two reinforcing layer base materials stretched in the process P110 to obtain two composite films (process P115). This process P115 is performed while conveying the two reinforcing layer base materials. The transport direction at this time coincides with the transport direction in the process P110. That is, the process P115 is performed while the reinforcement layer base material is conveyed in the same direction after the reinforcement layer base material is conveyed while being widened in the process P110. Hereinafter, the two composite films are referred to as a first composite film (first composite film 141 described later) and a second composite film (second composite film 142 described later). Further, the reinforcing layer base material and the electrolyte base material used for the first composite film are the same as the first reinforcing layer base material (first reinforcing layer base material 121 described later) and the first electrolyte base material (described below). 1 electrolyte substrate 131). Similarly, the reinforcing layer base material and the electrolyte base material used for the second composite membrane are used as a second reinforcing layer base material (second reinforcing layer base material 122 described later) and a second electrolyte base material (described later). This is referred to as a second electrolyte substrate 132). The first electrolyte base material becomes the above-described first electrolyte layer 11 through a later step. Further, the second electrolyte base material becomes the above-described second electrolyte layer 12 through a subsequent process.

  FIG. 3 is an explanatory diagram schematically showing the first composite film 141 and the second composite film 142 after the execution of the process P115. The X axis coincides with the transport direction of the first composite film 141. The Y axis coincides with the width direction of the first composite film 141. Further, the + Z direction indicates a vertically upward direction. As shown in FIG. 3, in step P115, the first reinforcing layer base 121 and the second reinforcing layer base 122 have different surfaces on which the electrolyte base is bonded. Specifically, the first electrolyte substrate 131 is bonded to the upper surface (the surface in the + Z direction) of the first reinforcing layer substrate 121, and the lower surface of the second reinforcing layer substrate 122. The second electrolyte base material 132 is bonded to the (surface in the -Z direction). Therefore, the two composite films after the execution of the process P115 have a configuration in which they are turned upside down. Further, as shown in FIG. 3, the transport direction of the first composite film 141 and the transport direction of the second composite film 142 are orthogonal to each other. In addition, the first composite film 141 is transported higher than the second composite film 142.

  As shown in FIG. 2, the first composite film 141 and the second composite film 142 are each cut into a predetermined size (process P120). Hereinafter, the first composite film and the second composite film after being cut in step P120 are also referred to as composite films, respectively. Both the first composite film 141 and the second composite film 142 are cut along the width direction. At this time, the composite films 141 and 142 after cutting are cut so that the lengths in the transport direction are substantially equal to the widths of the composite films 141 and 142.

  FIG. 4 is an explanatory diagram schematically showing the first composite film and the second composite film after the execution of the process P120. As shown in FIG. 4, the planar view shape of the cut first composite film (hereinafter referred to as “first composite film 41”) is substantially square. Similarly, the shape of the second composite film after cutting (hereinafter referred to as “second composite film 42”) in plan view is substantially square. As described above, since the transport direction of the first composite film 141 and the transport direction of the second composite film 142 are orthogonal to each other, the transport direction of the first composite film 141 and the second composite film 142 are the same. The width direction of the first composite film 141 coincides with the transport direction of the second composite film 142.

  As shown in FIG. 2, the 1st composite film 41 and the 2nd composite film 42 are bonded together (process P125). FIG. 5 is an explanatory view schematically showing the state of the first composite film 41 and the second composite film 42 when the process P125 is executed. As shown in FIG. 5, in the process P125, the first reinforcing layer base material 121 of the first composite film 41 and the second reinforcing layer base material 122 of the second composite film 42 are in contact with each other. The composite film 41 and the second composite film 42 are bonded together. Here, as described above, the elastic modulus maximum direction EMD of the first composite film 41 is the width direction of the first composite film 141, that is, the direction parallel to the Y axis, and the elasticity of the second composite film 42. Since the maximum modulus direction EMD is the width direction of the second composite film 142, that is, the direction parallel to the X axis, the maximum modulus of elasticity direction EMD is bonded so as to be orthogonal to each other in step P125. In the following description, a structure in which the first composite film 41 and the second composite film 42 are bonded together is referred to as a reinforced electrolyte film precursor 50. In the present embodiment, the above-described process P120 and process P125 are performed almost simultaneously. That is, cutting (process P120) and bonding (process P125) are performed at a location where the two composite films 141 and 142 shown in FIG.

  As shown in FIG. 2, a hot pressure is applied to the reinforced electrolyte membrane precursor 50 in the thickness direction (Z-axis direction) (step P130). FIG. 6 is an explanatory view schematically showing the reinforced electrolyte membrane precursor 50 after the execution of the process P130. As shown in FIG. 6, in the reinforced electrolyte membrane precursor 50, heat pressure is applied from the + Z direction of the first electrolyte base 131 to the −Z direction, and from the −Z direction of the second electrolyte base 132. Hot pressure is applied in the + Z direction. As a result, the first electrolyte base material 131 is impregnated into the first reinforcing layer base material 121 in the first composite film 41. Similarly, in the second composite membrane 42, the second electrolyte base material 132 is impregnated into the second reinforcing layer base material 122. In addition, the first reinforcing layer base 121 and the second reinforcing layer base 122 are joined to form one layer by heat pressure. Thus, in the reinforced electrolyte membrane precursor 50, the first electrolyte base 131, the second electrolyte base 132, the first reinforcing layer base 121, and the second reinforcing layer base 122 are integrated. Will be.

As shown in FIG. 2, hydrolysis treatment is performed on the reinforced electrolyte membrane precursor 50 (process P135). Specifically, the reinforced electrolyte membrane precursor 50 is immersed in an alkaline solution, and the —SO ₂ F group, which is a side chain terminal of the electrolyte polymer, is modified to —SO ₃ Na group. The reinforced electrolyte membrane precursor 50 is washed with pure water and then immersed in an acidic solution to denature —SO ₃ Na groups into —SO ₃ H groups. Thereby, proton conductivity is imparted to the electrolyte polymer of the reinforced electrolyte membrane precursor 50, and the reinforced electrolyte membrane 60 is completed. At this time, the first electrolyte base 131 of the reinforced electrolyte membrane precursor 50 shown in FIG. 6 becomes the first electrolyte layer 11 of the reinforced electrolyte membrane 60. Similarly, the second electrolyte substrate 132 of the reinforced electrolyte membrane precursor 50 is formed on the second electrolyte layer 12 of the reinforced electrolyte membrane 60 and the first reinforcing layer substrate 121 of the reinforced electrolyte membrane precursor 50. Are formed in the reinforcing layer 20 of the reinforcing electrolyte membrane 60 and the second reinforcing layer base material 122 of the reinforcing electrolyte membrane precursor 50 is formed in the reinforcing layer 20 of the reinforcing electrolyte membrane 60, respectively.

  According to the manufacturing method of the reinforced electrolyte membrane 60 in the present embodiment described above, the elastic modulus of the first reinforcing layer base 121 is obtained when the first composite membrane 41 and the second composite membrane 42 are bonded together. Since the maximum direction EMD and the maximum elastic modulus direction EMD of the second reinforcing layer base material 122 are bonded so as to be orthogonal to each other, the direction in which the elastic modulus is maximum in the reinforcing layer 20 is limited to one direction. The strength gradient depending on the direction in the reinforced electrolyte membrane 60 can be reduced. In addition, since the strength gradient depending on the direction can be easily reduced by controlling the direction in which the first reinforcing layer base 121 and the second reinforcing layer base 122 are bonded together, the reinforced electrolyte membrane 60 can be reduced. An increase in manufacturing cost can be suppressed. In addition, after the first composite film 41 and the second composite film 42 are bonded to each other, the first electrolyte base 131 in the first composite film 41 is subjected to the first reinforcement by applying heat pressure. Impregnation into the layer base material 121, the second electrolyte base material 132 impregnates into the second reinforcing layer base material 122 in the second composite membrane 42, and the first reinforcing layer in the reinforced electrolyte membrane precursor 50. Since the base material 121 and the second reinforcing layer base material 122 are integrated, a reinforced electrolyte membrane 60 with higher strength can be obtained.

B. Example B1. First Example A reinforced electrolyte membrane (Sample 1) was manufactured based on the embodiment described above. In addition, a reinforced electrolyte membrane (Sample 2) was produced as a comparative example. The dimensional change rate was measured for these two reinforced electrolyte membranes.

Sample 1 as the first example was manufactured as follows.
[1] In Step P105, an electrolyte base material of 4 μm was manufactured by an extrusion film forming method at 200 ° C. Further, a porous membrane material of polytetrafluoroethylene (PTFE) having a porosity of 60% and a thickness of 3 μm was produced as a reinforcing layer substrate.
[2] In Step P115, the electrolyte base material and the reinforcing layer base material manufactured in [1] were bonded together to manufacture two composite films 141 and 142.
[3] In step P125, the reinforcing layer base material of the first composite film 141 and the reinforcing layer base material of the second composite film 142 are connected to the transport direction of the first composite film 141 and the second composite film 142. The reinforced electrolyte membrane precursor 50 was prepared by arranging it so as to be orthogonal to the width direction, and a pressure of 2 MPa was applied to the reinforced electrolyte membrane precursor 50 at a temperature of 230 ° C.
[4] In step P135, the reinforced electrolyte membrane precursor 50 manufactured in [3] is immersed in a sodium hydroxide (NaOH) solution and nitric acid (HNO ₃ ), respectively, to manufacture a reinforced electrolyte membrane 60 having a thickness of about 10 μm. did.

  Sample 2 as a comparative example is the same as that in [3] (process P125) described above except that the first composite film 141 and the second composite film 142 are arranged so that the transport directions are the same. Manufactured in the same procedure as Sample 1 of the Example.

  FIG. 7 is an explanatory diagram showing the results of measuring the dimensional change rate of the sample 1 of the first example and the sample 2 of the first comparative example. The dimensional change rate was measured as follows. That is, a reinforced electrolyte membrane 60 of 60 mm × 60 mm is prepared and placed in a wet environment for a predetermined time, and then the reinforced electrolyte membrane 60 is dried. Thereafter, the dimensions in the transport direction and the width direction are measured, and the ratio is determined. Calculated. “Placed in a humid environment” means soaking in hot water at 80 ° C., and “Drying” means drying at 80 ° C. In FIG. 7, the dimensional change rate in the transport direction of the first composite film 141 and the width direction of the second composite film 142 and the width direction of the first composite film 141 and the second composite film 142 of the sample 1 are shown. The dimensional change rate in the conveyance direction is shown. Moreover, about the sample 2, the dimensional change rate of a conveyance direction and the dimensional change rate of the width direction are shown.

  As shown in FIG. 7, in the sample 2 of the first comparative example, the dimensional change rate in the transport direction and the dimensional change rate in the width direction are greatly different. Specifically, the dimensional change rate in the width direction of the sample 2 is about 6% larger than the dimensional change rate in the transport direction of the sample 2. In contrast, in the sample 1 of the first embodiment, the dimensional change rate in the transport direction of the first composite film 141 (and the width direction of the second composite film 142) and the width of the first composite film 141 There is no significant difference from the dimensional change rate in the direction (and the transport direction of the second composite film 142). Specifically, the dimensional change rate in the transport direction of the first composite film 141 (and the width direction of the second composite film 142) is equal to the width direction of the first composite film 141 (and the second composite film 142). About 0.5% smaller than the dimensional change rate in the conveyance direction). Therefore, it can be said that the intensity gradient depending on the direction in the sample 1 is lower than the intensity gradient depending on the direction in the sample 2. This is because, when the first composite film 141 and the second composite film 142 are bonded together, the maximum elastic modulus direction EMD of each reinforcing layer base material is bonded so as to be orthogonal to each other. Guessed.

B2. Second Example A reinforced electrolyte membrane (sample 3) was produced by the same method as in the first example. In addition, a reinforced electrolyte membrane (sample 4) was manufactured by the same method as the first comparative example described above as the second comparative example. Next, a membrane electrode assembly was manufactured using Sample 3 and Sample 4, and a fuel cell was manufactured using these membrane electrode assemblies. And each fuel cell was made to generate electric power, durability evaluation of the reinforced type electrolyte membrane by cell power generation was performed, and the durability was evaluated.

  FIG. 8 is an explanatory diagram showing the results of evaluating the durability of the reinforced electrolyte membrane using the sample 3 of the second example and the sample 4 of the second comparative example. Durability was measured (evaluated) as follows. That is, the dry state and the wet state are repeated with a constant cycle (cycle time 100 seconds), and the number of cycles until gas leakage between the electrodes due to breakage of the electrolyte membrane is measured. The larger the number of cycles, the higher the durability. It was evaluated.

  As shown in FIG. 8, the sample 3 of the second example has a larger number of cycles and higher durability until the gas leak between the electrodes due to breakage of the electrolyte membrane occurs compared to the sample 4 of the second comparative example. It was evaluated. This is because the sample 3 of the second embodiment uses a reinforced electrolyte membrane with a reduced strength gradient, thereby avoiding that the direction of low strength is limited to one direction. It is presumed that the stress concentration in one direction was restrained when the dimensional change of the electrolyte membrane due to the occurrence of severance occurred, and the occurrence of damage such as tearing of the electrolyte membrane was restrained.

C. Modification C1. Modification 1
In the above-described embodiment and examples, the reinforcing layer 20 of the reinforced electrolyte membrane 60 is formed of two substrates in which the first reinforcing layer substrate 121 and the second reinforcing layer substrate 122 are stacked. However, the present invention is not limited to this. For example, you may form by the laminated | stacked N piece (N is an integer greater than or equal to 3) base material. In this case, the reinforced electrolyte membrane 60 with higher strength can be obtained by laminating (bonding) the N base materials so that the elastic modulus maximum directions EMD cross each other.

C2. Modification 2
In the embodiment and examples described above, the first reinforcing layer base 121 and the second reinforcing layer base 122 are arranged so that the respective width directions are orthogonal to each other, but the present invention is limited to this. Not. The crossing may be performed at an arbitrary angle other than orthogonal. In addition, when the maximum elastic modulus direction EMD of one reinforcing layer base material matches the width direction and the maximum elastic modulus direction EMD of the other reinforcing layer base material matches the transport direction, The two composite membranes may be bonded together so that the width direction and the conveyance direction of the other reinforcing layer base material are orthogonal, that is, the width directions of the two reinforcing layer base materials are parallel to each other. That is, generally, the first composite film and the second composite film are made so that the maximum elastic modulus direction of the first reinforcing layer base material and the maximum elastic modulus direction of the second reinforcing layer base material intersect each other. The step of bonding may be used in the method for producing a reinforced electrolyte membrane of the present invention. Even in such a configuration, the same effects as in the embodiment can be obtained.

C3. Modification 3
In the said embodiment and Example, although the 1st reinforcement layer base material 121 and the 2nd reinforcement layer base material 122 were extended | stretched only to each width direction, this invention is not limited to this. While extending | stretching to the width direction, you may extend | stretch also to a conveyance direction. For example, the first reinforcing layer base 121 and the second reinforcing layer 122 are transported while applying a certain load in the transport direction to the first reinforcing layer base 121 and the second reinforcing layer base 122, respectively. The substrate 122 may be stretched in the transport direction. In this configuration, a greater force is applied to the first reinforcing layer base 121 and the second reinforcing layer base 122 in the transport direction than in the width direction, and both the reinforcing layer bases 121 and 122 are elastic. A case where the maximum rate direction EMD coincides with the transport direction may occur. In this case, by bonding the first composite film and the second composite film so that the transport direction of the first reinforcing layer base material 121 and the transport direction of the second reinforcing layer base material 122 cross each other. The same effects as in the embodiment are achieved.

C4. Modification 4
In the above-described embodiment and example, the following processing may be performed instead of the process P115 and the process P125 shown in FIG. After the execution of the process P110, the stretched first reinforcing layer base material 121 and the second reinforcing layer base material 122 are respectively cut in the same manner as in the process P120. Then, the cut first reinforcing layer base material 121 and second reinforcing layer base material 122 are bonded together so that the respective elastic modulus maximum directions EMD intersect each other. Thereafter, the electrolyte base material that has been separately stretched is bonded to the exposed surface of the first reinforcing layer base material 121 and the exposed surface of the second reinforcing layer base material 122, and then the process P130, the process P135 may be executed. In this configuration, after the execution of the process P130, the exposed surfaces of the reinforcing layer base materials 121 and 122 may be bonded to the electrolyte base material. Even in such a configuration, the same effects as in the embodiment can be obtained.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 11 ... 1st electrolyte layer 12 ... 2nd electrolyte layer 20 ... Reinforcement layer 41 ... 1st composite film 42 ... 2nd composite film 50 ... Reinforcement type electrolyte membrane precursor 60 ... Reinforcement type electrolyte membrane 121 ... 1st Reinforcing layer base material 122 ... Second reinforcing layer base material 131 ... First electrolyte base material 132 ... Second electrolyte base material 141 ... First composite film 142 ... Second composite film EMD ... Elastic modulus maximum direction

Claims (1)

A method for producing a reinforced electrolyte membrane comprising a reinforcing layer and a pair of electrolyte layers sandwiching the reinforcing layer,
(A) A first reinforcing layer base material that is a base material of the reinforcing layer and has a thickness smaller than that of the reinforcing layer on one surface of the first electrolyte base material that is a base material of the one electrolyte layer On one surface of the first composite membrane that is in contact with the second electrolyte base material that is the base material of the other electrolyte layer, the thickness of the base material of the reinforcing layer is smaller than that of the reinforcing layer. Bonding the second composite film in contact with the small second reinforcing layer base material so that the first reinforcing layer base material and the second reinforcing layer base material are in contact with each other;
(B) In the first composite membrane, the first electrolyte base material is impregnated in the first reinforcing layer base material, and in the second composite membrane, the second electrolyte base material is replaced with the second electrolyte base material. Impregnating the reinforcing layer base of
With
The first reinforcing layer base material and the second reinforcing layer base material each have a maximum elastic modulus direction in which the magnitude of the tensile elastic modulus is larger than the other directions,
In the step (a), the first composite film and the first composite layer so that the elastic modulus maximum direction of the first reinforcing layer base material and the elastic modulus maximum direction of the second reinforcing layer base material intersect each other. Including the step of bonding the second composite film,
A method for producing a reinforced electrolyte membrane.

Images