Porous carbonaceous material and a method for producing the same

A process for producing a porous composite sheet which comprises hot-pressing one or more plies of a web wherein a prepreg sheet is disposed in a first mold comprising at least one pair of opposed surfaces defining a molding compartment, at least one of said opposed surfaces being provided with grooves, under heating at 80.degree. to 200.degree. to provide a ribbed sheet and disposing said ribbed sheet, leaving a clearance, in a second mold comprising at least one pair of opposed surfaces defining a molding compartment, at least one of said opposed surfaces being provided with grooves larger than the grooves of said first mold, and heating said ribbed sheet at a temperature of 150.degree. to 250.degree. C. for expansion and complete cure of said resin.

A process of producing a porous carbonaceous material which comprises

• hot-pressing at least one of a random web comprising a precursor fiber convertible to carbon fiber and/or a carbon fiber and a carbonizable or graphitizable thermosetting resin while curing of said resin is inhibited to provide a prepreg sheet,
• heating the prepreg sheet at a temperature over the melting temperature of said resin under no load, for expansion and complete cure of the resin, and
• either carbonizing or graphitizing the resultant porous composite sheet.

A porous composite sheet which is prepared by a process comprising

• hot-pressing a random web comprising a precursor fiber convertible to carbon fiber and/or a carbon fiber and a carbonizable or graphitizable thermosetting resin while curing of said resin is inhibited to provide a prepreg sheet;
• and
• heating said prepreg sheet at a temperature of the melting point of said thermosetting resin or more under no load, for expansion and complete cure of said resin.

A porous carbonaceous material which is prepared by a process comprising

• hot-pressing at least one of a random web comprising a precursor fiber convertible to carbon fiber and/or a carbon fiber and a carbonizable or graphitizable thermosetting resin while curing of said resin is inhibited to provide a prepreg sheet,
• heating the prepreg sheet at a temperature over the melting temperature of said resin under no load for expansion and complete cure of the resin, and
• either carbonizing or graphitizing the resultant porous composite sheet.

A porous carbonaceous material which is prepared by a process comprising a step of hot-pressing at least one ply of a random web comprising a fiber component composed of a precursor fiber convertible to carbon fiber and/or a carbon fiber and, based on 100 parts by weight of said fiber component, 15 to 275 parts by weight of a carbonizable or graphitizable thermosetting resin with a carbonization yield of 50 to 75% by weight, 0 to 250 parts by weight of a pitch with a carbonization yield of not less than 50% by weight, and 0 to 250 parts by weight of an organic granular material with a mean particle diameter of 0.1 to 500 .mu.m while curing of said thermosetting resin is inhibited to provide a prepreg sheet;

• a step of heating said prepreg sheet at a temperature over the melting temperature of said resin under no load for expansion and complete cure of the resin;
• and
• a step of carbonizing or graphitizing the resultant porous composite sheet.

A porous carbonaceous material which is prepared by a process comprising

• hot-pressing one or more plies of a web wherein a prepreg sheet is disposed in a first mold comprising at least one pair of opposed surfaces defining a molding compartment, at least one of said opposed surfaces defining a molding compartment, at least one of said opposed surfaces being provided with grooves, under heating at 80.degree. to 200.degree. C. to provide a ribbed sheet and disposing said ribbed sheet, leaving a clearance, in a second mold comprising at least one pair of opposed surfaces defining a molding compartment, at least one of said opposed surfaces being provided with grooves larger than the grooves of said first mold,
• heating said ribbed sheet at a temperature of 150.degree. to 250.degree. C. for expansion and complete cure of said resin, and
• either carbonizing or graphitizing the resultant porous composite sheet.