Ceramic oxide fibers

Abstract

Tow of substantially continuous ceramic oxide fibers having a sizing material. Tows according to the present invention are useful, for example, for making metal matrix wires.

1 . A tow of substantially continuous ceramic oxide fibers, wherein each ceramic oxide fiber has an outer surface, wherein at least a portion of the outer surfaces of at least some of the ceramic oxide fibers have a sizing material therein, and wherein the sizing material comprises a composition represented by the formula: 
       R′O—(RO) n —H, wherein:    R′ is selected from C x H 2x+1 , wherein x is 1-8 or —H;    R is selected from the group consisting of —(C y H 2y )—, wherein y is 1-4, and —CH 2 —O—(CH 2 ) m —, wherein m=2-5; and    n is chosen such that the number average molecular weight is in a range from 500 g/mole to 7,000,000 g/mole.    
   
   
       2 . The tow according to  claim 1 , wherein the substantially continuous ceramic oxide fibers are crystalline.  
   
   
       3 . The tow according to  claim 1 , wherein the substantially continuous ceramic oxide fibers are selected from the group consisting of crystalline alumina fibers, crystalline aluminosilicate fibers, crystalline aluminoborosilicate fibers, and combinations thereof.  
   
   
       4 . The tow according to  claim 1 , wherein n is chosen such that the number average molecular weight is in a range from 500 g/mole to 3,000,000 g/mole.  
   
   
       5 . The tow according to  claim 1 , wherein n is chosen such that the number average molecular weight is in a range from 500 g/mole to 400,000 g/mole.  
   
   
       6 . A method of providing the tow of substantially continuous ceramic oxide fibers according to  claim 1 , the method comprising: 
 providing a tow of substantially continuous ceramic oxide fibers, wherein each ceramic oxide fiber has an outer surface;    coating at least a portion of the outer surfaces of at least some of the ceramic oxide fibers with an aqueous-based sizing material, wherein the sizing material comprises a composition represented by formula:     R 1 ′O′(R 1 O) n1 —H,   wherein:    R 1 ′ is selected from C x1 H 2x1+1 , wherein x1 is 1-8 or —H;    R 1  is selected from the group consisting of —(C y1 H 2y1 )—, wherein y 1  is 1-4, and —CH 2 —O—(CH 2 ) m1 —, wherein m 1 =2-5; and wherein n is chosen such that the number average molecular weight is in a range from 500 g/mole to 7,000,000 g/mole; and    removing at least a portion of the water.    
   
   
       7 . The method according to  claim 6 , wherein the aqueous-based sizing material is a solution.  
   
   
       8 . The method according to  claim 6 , wherein the aqueous-based sizing material is an emulsion.