Pipd Paper and Components Made Therefrom

Abstract

The invention concerns a paper useful as an structural component, the paper comprising 20 to 100 percent by weight of polypyridobisimidazole fiber and a binder material, wherein the paper has (i) a density of 0.08 to 1.5 grams per cubic centimeter and (ii) a basis weight of from 10 to 150 grams per square meter, and the paper, when impregnated with at least 15% by weight of phenolic resin, has a specific tensile stiffness of at least 100 (N/cm)/(g/m 2 ), wherein the weight % is based on the total weight of the paper and resin.

1 . A paper useful as an structural component, the paper comprising 20 to 100 percent by weight of polypyridobisimidazole fiber and optionally a binder material, wherein the paper has (i) a density of 0.08 to 1.5 grams per cubic centimeter and (ii) a basis weight of from 10 to 150 grams per square meter, and the paper, when impregnated with at least 15% by weight of phenolic resin, has a specific tensile stiffness of at least 100 (N/cm)/(g/m 2 ), wherein the weight % is based on the total weight of the paper and resin. 
   
   
       2 . The paper of  claim 1  wherein the binder material is chosen from the group consisting of thermoset and thermoplastic resins in the form of solutions, emulsions, suspensions, powders, flakes, and fibers; fibrids; and pulps from polymers other than polypyridobisimidazole. 
   
   
       3 . The paper of  claim 1  wherein the polypyridobisimidazole fiber is PIPD. 
   
   
       4 . The paper of  claim 1  having a specific tensile stiffness after impregnation with phenolic resin of 110-150 N/cm)/(g/m 2 ). 
   
   
       5 . The paper of  claim 1  having a Gurley Hill porosity of from 1 to 20 seconds. 
   
   
       6 . The paper of  claim 5  having a Gurley Hill porosity of from 5 to 12 seconds. 
   
   
       7 . The paper of  claim 3  having 70 to 90 percent by weight PIPD fiber. 
   
   
       8 . The paper of  claim 1  having a density of 0.6 to 1.2 grams per cubic centimeter. 
   
   
       9 . The paper of  claim 1  further comprising at least one of conductive fillers, antioxidants, pigments, and catalysts. 
   
   
       10 . The paper of  claim 1  wherein PIPD fiber is introduced into the paper in the form of the floc. 
   
   
       11 . The paper of  claim 1  wherein PIPD fiber is introduced into the paper in the form of the pulp. 
   
   
       12 . The paper of  claim 1  wherein PIPD fiber is introduced into the paper as a blend of PIPD floc and PIPD pulp. 
   
   
       13 . A structural core comprising the paper of  claim 1 . 
   
   
       14 . A honeycomb core comprising the paper of  claim 1 . 
   
   
       15 . A folded paper core comprising the paper of  claim 1 . 
   
   
       16 . A printed wiring board comprising the paper of  claim 1 . 
   
   
       17 . A sandwich panel comprising the paper of  claim 1 . 
   
   
       18 . A method of making a paper comprising:
 forming a slurry of polypyridobisimidazole fiber and optionally a binder; and   removing at least a portion of the water in one or more steps to form a paper;   wherein the paper has (i) a density of 0.08 to 1.5 grams per cubic centimeter and (ii) a basis weight of from 10 to 150 grams per square meter, and the paper, when impregnated with at least 15% by weight of phenolic resin, has a specific tensile stiffness of at least 100 (N/cm)/(g/m 2 ), wherein the weight % is based on the total weight of the paper and resin.   
   
   
       19 . The method of  claim 18  further comprising calendering of the formed paper at ambient or increased temperature. 
   
   
       20 . The method of  claim 18  wherein the polypyridobisimidazole fiber is PIPD.