Random Mat and Fiber-Reinforced Composite Material Shaped Product

Abstract

There is provided a random mat including reinforcing fibers having an average fiber length of 3 to 100 mm and a thermoplastic resin, wherein the reinforcing fibers satisfy the following i) to iii). i) The reinforcing fibers have a weight-average fiber width (Ww) which satisfies the following equation (1). 0 mm<Ww<2.8 mm   (1) ii) The reinforcing fibers have an average-fiber-width dispersion ratio (Ww/Wn), which is defined as a ratio of the weight-average fiber width (Ww) to a number-average fiber width (Wn), of 1.00 or more and 2.00 or less. iii) The reinforcing fibers have a weight-average fiber thickness which is smaller than the weight-average fiber width (Ww) thereof.

1 . A random mat, comprising:
 reinforcing fibers having an average fiber length of 3 to 100 mm; and   a thermoplastic resin,   wherein the reinforcing fibers satisfy the following i) to iii):
 i) the reinforcing fibers have a weight-average fiber width (Ww) which satisfies the following equation (1):
   0 mm<Ww<2.8 mm   (1);
 
 
 ii) the reinforcing fibers have an average-fiber-width dispersion ratio (Ww/Wn), which is defined as a ratio of the weight-average fiber width (Ww) to a number-average fiber width (Wn), of 1.00 or more and 2.00 or less; and 
 iii) the reinforcing fibers have a weight-average fiber thickness which is smaller than the weight-average fiber width (Ww), and 
   the weight-average fiber thickness of the reinforcing fibers is 0.01 mm or more and 0.30 mm or less.   
     
     
         2 . The random mat according to  claim 1 ,
 wherein the reinforcing fibers are at least one kind selected from the group consisting of carbon fibers, aramid fibers, and glass fibers.   
     
     
         3 . The random mat according to  claim 1 ,
 wherein the weight-average fiber width (Ww) of the reinforcing fibers satisfies the following equation (2):
   0.1 mm<Ww<2.0 mm   (2).
 
   
     
     
         4 . The random mat according to  claim 1 , wherein the average-fiber-width dispersion ratio (Ww/Wn) of the reinforcing fibers is 1.30 or more and 1.95 or less. 
     
     
         5 . The random mat according to  claim 1 , wherein the weight-average fiber thickness of the reinforcing fibers is 0.02 mm or more and 0.20 mm or less. 
     
     
         6 . The random mat according to  claim 1 , which has a reinforcing-fiber areal weight of 25 to 10,000 g/m 2 . 
     
     
         7 . The random mat according to  claim 1 , wherein a content of the thermoplastic resin present is 10 to 800 parts by weight per 100 parts by weight of the reinforcing fibers. 
     
     
         8 . A fiber-reinforced composite material shaped product obtained from the random mat according to  claim 1 . 
     
     
         9 . The fiber-reinforced composite material shaped product according to  claim 8 , comprising:
 reinforcing fibers having an average fiber length of 3 to 100 mm; and   a thermoplastic resin, wherein the reinforcing fibers satisfy the following i) to iii):
 i) the reinforcing fibers have a weight-average fiber width (Ww) which satisfies the following equation (1):
   0 mm<Ww<2.8 mm   (1);
 
 
 ii) the reinforcing fibers have a dispersion ratio (Ww/Wn), which is defined as the ratio of the weight-average fiber width (Ww) to a number-average fiber width (Wn), of 1.00 or more and 2.00 or less; 
 iii) the reinforcing fibers have a weight-average fiber thickness which is smaller than the weight-average fiber width (Ww). 
   
     
     
         10 . The fiber-reinforced composite material shaped product according to  claim 8 , comprising a reinforcing-fiber mat constituted by the reinforcing fibers,
 wherein the reinforcing-fiber mat having a thickness unevenness of 20% or less in terms of a coefficient of variation CV defined by the following equation (3):
   Coefficient of variation  CV  (%)=[(standard deviation)/(average value)]×100   (3).
 
   
     
     
         11 . The fiber-reinforced composite material shaped product according to  claim 8 , which has a wall thickness of 0.2 to 100 mm.