HEAT-BONDABLE POLYACRYLONITRILE FIBER

摘要

PURPOSE:To provide a polyacrylonitrile(PAN) fiber bondable by heat-bonding while keeping the characteristic performance of PAN fiber, having high purity and causing small dimensional change in heat-bonding. CONSTITUTION:This heat-bondable PAN fiber has a sea-island structure consisting of a sea component composed of a PAN polymer containing 55-99wt.% of acrylonitrile component and an island component composed of a polymer having a heat-fusion temperature lower than that of the PAN polymer by >=30 deg.C. The blending weight ratio of both polymers is 98/2 to 60/40. The PAN polymer of the outermost layer is broken in the heat-bonding to squeeze out the polymer of the island component to the fiber surface to develop the adhesive force. At least a part of the island component polymer is preferably present at a depth of 0.01-2mum from the outermost layer. Acrylic nonwoven fabric having a sufficiently high bonding strength can be produced by heat- bonding a web containing >=10% of the PAN fiber at a heat-bonding temperature of 60-210 deg.C and a linear pressure of >=1kg/cm (usually 5-50kg/cm) or an areal pressure of >=2kg/cm<2> (usually 10-100kg/cm<2>).