摘要:
A process is disclosed whereby porous flakes usable for making paper-like sheets are produced by melting a 10 to 75 parts by weight of thermoplastic polymer, dispersing 25 to 90 parts by weight of finely divided inorganic particles in a solvent capable of dissolving the polymer in an amount of 80 to 95% based on a total weight of the polymer, the inorganic particles and the solvent, at room temperature or lower to prepare a slurry. At a temperature at which the polymer can be dissolved in the solvent, the polymer melt is mixed with the slurry which has been preliminarily heated to a temperature pertinent for realizing the above-mentioned dissolving temperature when the heated slurry is mixed with the polymer melt, to prepare a uniform dispersion of the inorganic particles in the polymer solution in the solvent and then, the dispersion is spurted from a closed tank through an orifice, into a zone having a temperature and pressure lower than that of the dispersion, whereby the spurted dispersion is converted to composite porous flakes by rapidly evaporating the solvent.
摘要:
Flake- or sliver-like porous structures of a polymeric material heavily loaded with a finely divided inorganic substance are prepared by spurting a mixture of the polymeric and finely divided inorganic components in a solvent. The products have many fine, irregular voids. The thickness of walls forming such voids is 5.mu. or less. The products are especially useful for producing sheet-like structures therefrom by beating and/or refining them followed by general paper making procedures. The sheets, when calendered, have a high initial modulus and improved dimensional stability.