Carbon fiber bundle

Abstract

A carbon fiber bundle including fibers having a surface on which a fibril(s) is/are present along the fiber axis direction, wherein in a single fiber tensile test at a gauge length of 50 mm in accordance with JIS R7606 (2000), the ratio of the number of fibers having a fracture surface where a fibrillar substance(s) with an aspect ratio of 3.0 to 10.0 is/are present in the fracture origin is 1 to 20%, and the ratio of the number of fibers having a fracture surface where a void(s) of not less than 100 nm is/are present in the fracture origin is 1 to 14%, and wherein the number of filaments is 48,000 to 60,000. An object of the present invention is to provide a carbon fiber bundle having excellent strength, and excellent process stability during further processing, while having high total fineness.

1 . A carbon fiber bundle comprising fibers having a surface on which a fibril(s) is/are present along the fiber axis direction,
 wherein in a single fiber tensile test at a gauge length of 50 mm in accordance with JIS R7606 (2000), the ratio of the number of fibers having a fracture surface where a fibrillar substance(s) with an aspect ratio of 3.0 to 10.0 is/are present in the fracture origin is 1 to 20%, and the ratio of the number of fibers having a fracture surface where a void(s) of not less than 100 nm is/are present in the fracture origin is 1 to 14%, and   wherein the number of filaments is 48,000 to 60,000.   
     
     
         2 . The carbon fiber bundle according to  claim 1 , comprising fibers having a surface on which a fibril(s) is/are present along the fiber axis direction,
 wherein in a single fiber tensile test at a gauge length of 50 mm in accordance with JIS R7606 (2000), when the ratio of the number of fibers having a fracture surface where a fibrillar substance(s) with an aspect ratio of 3.0 to 10.0 is/are present in the fracture origin is A (%), and the ratio of the number of fibers having a fracture surface where a void(s) of not less than 100 nm is/are present in the fracture origin is B (%), A and B satisfy the relationship of the following Formula (1):   
       
         
           
             
               
                 
                   
                     
                       B 
                       ≤ 
                       
                         
                           
                             - 
                             
                               0 
                               . 
                               7 
                             
                           
                           ⁢ 
                           A 
                         
                         + 
                         
                           2 
                           ⁢ 
                           
                             0 
                             . 
                             5 
                           
                         
                       
                     
                     . 
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
       
     
     
         3 . The carbon fiber bundle according to  claim 1 , comprising fibers having a surface on which a fibril(s) is/are present along the fiber axis direction,
 wherein in a single fiber tensile test at a gauge length of 50 mm in accordance with JIS R7606 (2000), the ratio of the number of fibers having a fracture surface where a fibrillar substance(s) with an aspect ratio of 3.0 to 10.0 is/are present in the fracture origin is 1 to 15%, and the ratio of the number of fibers having a fracture surface where a void(s) of not less than 100 nm is/are present in the fracture origin is 1 to 10%.   
     
     
         4 . The carbon fiber bundle according to any one of  claims 1 to 3 , having a fibril width of 100 to 600 nm. 
     
     
         5 . The carbon fiber bundle according to any one of  claims 1 to 4 , having a strand strength of 4.5 to 6.0 GPa.