POROUS COMPOSITE SHEET

PURPOSE:To provide a porous composite sheet comprising reinforcing fibers, a phenolic resin binder and a hydrophilic clay mineral, having many penetrated open pores, specific porosity and specified water drop-absorbing property, good in the high temperature durability and useful for water-absorbing materials, humidity-adjusting materials, etc. CONSTITUTION:Reinforcing fibers (e.g. polyethylene terephthalate fibers) and a fine spherical phenolic resin binder are mixed with each other and formed into a web by the use of a carding machine, etc. The formed web is passed through calender rolls set to a temperature of 120 deg.C to produce a composite web having thickness of 2mm, weight of 180g/m and width of 600mm. The composite web is coated with a dispersion comprising a hydrophilic clay mineral (e.g. sepiolite) homogeneously dispersed in water, and subsequently dried to provide the objective porous composite sheet having thickness of 2mm, average weight of 240g/m , many open pores penetrated from one side of the sheet to the other side, porosity of 40-80%, and water drop-absorbing property of