Polymer electrolyte material, polymer electrolyte molded product using the polymer electrolyte material, and method for manufacturing the polymer electrolye molded product, membrane electrode composite, and solid polymer fuel cell

Abstract

It is an object of the present invention to provide a polymer electrolyte material which has excellent proton conductivity even under the conditions of a low humidity or a low temperature and is excellent in mechanical strength and fuel barrier properties, and which moreover can achieve high output, high energy density and long-term durability in forming a polymer electrolyte fuel cell therefrom, and a polymer electrolyte form article using the same and a method for producing the same, a membrane electrode assembly and a polymer electrolyte fuel cell, each using the same. The present invention employs the following means. Namely, the polymer electrolyte material of the present invention is a polymer electrolyte material including a constituent unit (A1) containing an ionic group and a constituent unit (A2) substantially not containing an ionic group, wherein a phase separation structure is observed by a transmission electron microscope and a crystallization heat measured by differential scanning calorimetry is 0.1 J/g or more, or a phase separation structure is observed by a transmission electron microscope and the degree of crystallinity measured by wide angle X-ray diffraction is 0.5% or more. Also, the polymer electrolyte form article, the membrane electrode assembly and the polymer electrolyte fuel cell of the present invention are characterized by being composed of such polymer electrolyte materials.

1 . A polymer electrolyte material including a constituent unit (A1) containing an ionic group and a constituent unit (A2) substantially not containing an ionic group, wherein a phase separation structure is observed by a transmission electron microscope and a crystallization heat measured by differential scanning calorimetry is 0.1 J/g or more, or a phase separation structure is observed by a transmission electron microscope and the degree of crystallinity measured by wide angle X-ray diffraction is 0.5% or more. 
     
     
         2 . The polymer electrolyte material according to  claim 1 , wherein the polymer electrolyte material is an ionic group-containing block copolymer composed of a block (B1) containing an ionic group and a block (B2) substantially not containing an ionic group and a ratio W1/W2 of a molar amount W1 of B1 to a molar amount W2 of B2 is 0.2 or more and 5 or less. 
     
     
         3 . The polymer electrolyte material according to  claim 1 , wherein the ionic group-containing copolymer is an aromatic polyetherketone-type polymer. 
     
     
         4 . The polymer electrolyte material according to  claim 2 , wherein the block (B2) substantially not containing an ionic group comprises a constituent unit represented by the following general formula (Q1): 
       
         
           
           
               
               
           
         
       
       Z 1  and Z 2  in the general formula (Q1) represent a divalent organic group containing an aromatic ring and each of Z 1  and Z 2  may represent two or more kinds of groups but does not substantially contain an ionic group; and a and b each independently represents a positive integer. 
     
     
         5 . The polymer electrolyte material according to  claim 4 , wherein the Z 1  in said general formula (Q1) is a phenylene group and the Z 2  in said general formula (Q1) is at least one selected from the following general formulas (X-1), (X-2), (X-4) and (X-5): 
       
         
           
           
               
               
           
         
       
       the groups represented by the general formula (X-1), (X-2), (X-4) or (X-5) may be optionally substituted with a group other than the ionic group. 
     
     
         6 . The polymer electrolyte material according to  claim 4 , wherein the Z 1  and the Z 2  in the general formula (Q1) are a phenylene group. 
     
     
         7 . The polymer electrolyte material according to  claim 1 , wherein said ionic group is a sulfonic acid group. 
     
     
         8 . The polymer electrolyte material according to  claim 1 , wherein the density of the sulfonic acid group of the block (B1) containing an ionic group is 1.7 to 5.0 mmol/g and the density of the sulfonic acid group of the block (B2) substantially not containing an ionic group is 0 to 0.5 mmol/g. 
     
     
         9 . The polymer electrolyte material according to  claim 1 , wherein the block (B1) containing an ionic group comprises constituent units represented by the following general formulas (P1) and (P2): 
       
         
           
           
               
               
           
         
       
       in the general formulas (P1) and (P2), A represents a divalent organic group containing an aromatic ring and M 1  and M 2  represent hydrogen, a metal cation, or an ammonium cation; and A may represent two or more kinds of groups. 
     
     
         10 . The polymer electrolyte material according to  claim 9 , wherein said A is: at least one kind of constituent unit selected from the following general formulas (X-1) to (X-7): 
       
         
           
           
               
               
           
         
       
       the groups represented by the general formulas (X-1) to (X-7) may be optionally substituted. 
     
     
         11 . A method for producing a polymer electrolyte form article composed of an ionic group-containing block copolymer, having a block (B1) containing an ionic group and a block (B2) substantially not containing an ionic group, in which a ratio W1/W2 of weight W1 of the B1 to weight W2 of the B2 is 0.2 or more and 5 or less, wherein a polymer electrolyte material formed by introducing protective groups into at least the block (B2) substantially not containing an ionic group is formed and then at least a portion of the protective groups contained in the form article is deprotected. 
     
     
         12 . A polymer electrolyte form article, which is composed of the polymer electrolyte material according to  claim 1 . 
     
     
         13 . A membrane electrode assembly, which is composed of the polymer electrolyte material according to  claim 1 . 
     
     
         14 . A polymer electrolyte fuel cell, which is composed of the polymer electrolyte material according to  claim 1 .