Patent ID: 11951692
Assignee: MITSUBISHI CHEMICAL CORPORATION
Field: Measurement (Instruments)
Classification: CPC B  C  G  Y | IPC B  C  G

Claim 4:
5. A sheet-shaped fiber-reinforced resin material comprising dispersed carbon fiber bundles impregnated with a thermosetting resin and having a longitudinal direction and a width direction, wherein, when the longitudinal direction of the fiber-reinforced resin material is defined as a 0° direction and the width direction is defined as a 90° direction, a diffracted X-ray at a diffraction angle 2θ of 25.4° is detected by an X-ray diffraction method, and a sum of an average value and a standard deviation of a degree of crystal orientation fa of the fiber bundle based on the 0° direction obtained by the following Formulas (4) to (6) is in a range of 0.05 to 0.13,

fa=2a-1  (4), a
     =
     
      
       
        
         ∑
          
        
        
         í
         =
         1
        
        N
       
       ⁢
       
        I
        ⁡
        (
        
         ϕ
         i
        
        )
       
       ⁢
       
        cos
        2
       
       ⁢
         
       
        ϕ
        i
       
      
      
       
        
         ∑
          
        
        
         i
         =
         1
        
        N
       
       ⁢
       
        I
        ⁡
        (
        
         ϕ
         i
        
        )
       
      
     
    
   
   
    
     (
     5
     )
    
   
  
 

 
  
   
    
     
      
       
        ∫
        0
        
         3
         ⁢
         6
         ⁢
         0
        
       
       
        
         I
         ⁡
         (
         ϕ
         )
        
        ⁢
        d
        ⁢
        ϕ
       
      
      =
      
       
        
         ∑
         
          i
          =
          2
         
         N
        
        
         
          (
          
           
            I
            ⁡
            (
            
             ϕ
             i
            
            )
           
           +
           
            I
            ⁡
            (
            
             ϕ
             
              i
              -
              1
             
            
            )
           
          
          )
         
         ×
         d
         ⁢
         ϕ
         ×
         
          1
          2
         
        
       
       =
       10000
      
     
    
   
   
    
     
      (
      6
      ), wherein:
“aa” is an orientation coefficient represented by Formula (5), and
I(ϕi) is a luminance at an i-th rotation angle (ϕi) in X-ray diffraction measurement and is normalized so that an integration strength represented by Formula (6) becomes 10000.