Sound absorbing and heat insulating material, and method of manufacturing same

A method of manufacturing thermal-acoustic insulation material, comprising the steps of:

• producing spun fibers having an average fiber diameter less than 2 am and an average fiber length of 1 mm to 15 mm by heating and melting anisotropic pitch obtained by polymerizing condensed polycyclic hydrocarbon, then discharging a melted matter out of a spinning nozzle and at the same time, blowing a heated gas from around the spinning nozzle in the same direction in which the melted matter is discharged;
• manufacturing non-galvanic corrosive carbon fibers by infusibilizing said spun fibers and thereafter carbonizing said spun fibers at not lower than 550° C. but lower than 800° C.;
• forming a carbon fiber aggregate having a bulk density less than 1.3 kg/m3 by aggregating said non-galvanic corrosive carbon fibers;
• spraying a thermosetting resin solution to the carbon fiber aggregate;
• and
• curing the thermosetting resin by compressing and heating the carbon fiber aggregate sprayed with the thermosetting resin solution to bond contact points of said carbon fibers and thereby manufacture a three dimensional structure of carbon fibers having a bulk density of from 3 kg/m3 to 10 kg/m3.

A method of manufacturing a thermal-acoustic insulation material, comprising the steps of:

• producing spun fibers having an average fiber diameter of 1.3 μm or less and an average fiber length of 1 mm to 15 mm, said producing comprising heating and melting anisotropic pitch obtained by polymerizing condensed polycyclic hydrocarbon to produce melted pitch, and discharging said melted pitch out of a spinning nozzle while at the same time, blowing a heated gas from around the spinning nozzle in the same direction that the melted pitch is discharged, to form said spun fibers;
• manufacturing non-galvanic corrosive carbon fibers comprising infusibilizing said spun fibers to form infusibilized fibers and carbonizing said infusibilized fibers at not lower than 550° C. but lower than 800° C., to form said non-galvanic corrosive carbon fibers;
• forming a carbon fiber aggregate comprising aggregating and compressing said non-galvanic corrosive carbon fibers to a bulk density of from (3−b) kg/m3 to (10−b) kg/m3, to form said carbon fiber aggregate;
• spraying a thermosetting resin solution to said carbon fiber aggregate so that the amount of a thermosetting resin in relation to the amount of the carbon fiber aggregate is b, where b is an arbitrary number fixed so that the bulk density is positive and the relationship 0.3≦b≦4 is satisfied, to form a sprayed aggregate;
• and
• curing said thermosetting resin comprising heating said sprayed aggregate, to form a three-dimensional structure of carbon fibers, wherein said carbon fibers are bonded at contact points thereof, and said three-dimensional structure has a bulk density of from 3 kg/m3 to 10 kg/m3.