Unstretched synthetic papers and methods of producing same

Abstract

Novel, unstretched synthetic papers being virtually free of mechanically produced microvoids and having a porous surface for writing and printing thereon are disclosed. The unstretched synthetic papers of the instant invention are formed typically by extruding from pellets a film or sheet material formed with a continuous olefin resin matrix containing an effective amount of a particulate filler having pre-existing microvoids inherent thereto, such as a diatamaceous earth. The microvoid particulate filler is dispersed somewhat uniformly yet randomly throughout the continuous olefin resin matrix of the unstretched synthetic papers to provide non-mechanically produced microvoids in communication with the surfaces of the unstretched synthetic papers to render said surfaces porous for imparting writeability and printability thereto. Additional paper-like characteristics can be imparted to the novel, unstretched synthetic papers of the instant invention by the addition of other resins, such as a styrene resin, to the continuous olefin resin matrix. The novel, unstretched synthetic papers of the present invention have good receptivity and retentivity for common writing materials, such as ink, pencil lead, paint and the like, even though they are not mechanically stretched to form mechanically produced microvoids.