Abstract: Improved ethylene polymer fibrils are provided which are characterized in having:(a) a melt temperature of at least about 137.degree. C.,(b) a molecular weight of at least 250,000,(c) at least about 1.2 weight % of polyvinyl alcohol sorbed thereon, and(d) a zero-span breaking length of at least about 25,000.

Abstract: Paper having improved properties, particularly tear strength, is prepared from a furnish containing at least 90 weight % of cellulose fibers and up to 10 weight % of olefin polymer fibrils. The fibrils are prepared by a differential temperature process of the type described in U.S. Pat. No. 4,013,751, are refined in isopropanol, and are treated with an aqueous solution of polyvinyl alcohol to sorb at least 1.0 weight % of polyvinyl alcohol on the fibrils. The fibrils are prepared from an olefin polymer having a weight average molecular weight of at least one (1) million.

Abstract: Apparatus useful in the manufacture of thermoplastic Olefin polymer fibrils are prepared by a process carried out in a disc mill. A hot olefin polymer solution is fed into the working cavity defined by the discs. In passing through the working cavity, the hot polymer solution is broken up into a plurality of uniaxially-oriented liquid streams which follow tortuous liquid paths through the working cavity whereby each of the streams is attenuated to orient the solute polymer molecules in said streams. A coolant liquid is fed into the working cavity and cools the attenuated polymer streams to a temperature sufficiently low so that substantially all of the solute polymer is precipitated in the form of uniaxially-oriented polymer fibrils. The product recovered from the modified disc mill consists of a mixture of uniaxially-oriented polymer fibrils, polymer solvent, and coolant liquid. The fibrils are recovered and refined in subsequent downstream operations.

Abstract: The invention is directed to an apparatus useful for dissolving high molecular weight olefin polymers in a hot hydrocarbon solvent. The apparatus includes:(a) A plurality of interconnected fluid chambers, each of which has a fluid inlet and a fluid outlet,(b) Screens covering the inlet and the outlet of each fluid chamber; the screen covering the outlet having a smaller mesh than the screen covering the inlet,(c) Stirring means in each fluid chamber adapted to sweep retained polymer particles free of the screen covering the outlet of said chamber,(d) Means for pumping fluid through the fluid chambers, and(e) Means for supplying heat to fluid passing through the apparatus.

Abstract: Centrifugal spinning apparatus is provided for the manufacture of fibrils from hot viscous hydrocarbon solutions of olefin polymers having an intrinsic viscosity of at least 3.5. The apparatus consists of an impeller which rotates at high speed in a cylindrical cavity having a discharge port. The impeller has a plurality of blades whose narrow dimensions lie substantially in the plane of the impeller's rotation and whose tips come in close proximity to the inner peripheral surface of the cylindrical cavity. The blades are arranged in at least two substantially-identical sets. Within each set, the blades are offset substantially equidistant from one another, both in the rotational plane of the impeller and in the plane transverse thereto. Two inlet ports are provided in the peripheral surface of the cylindrical cavity to feed liquids to the cylindrical cavity, each of which port is narrow in a plane transverse to the plane of the impeller's rotation and extends over substantially the entire peripheral surface.

Abstract: A process is disclosed for removing phenols from dilute aqueous solutions thereof. The method consists of contacting the aqueous phenol solution with a mass of olefin polymer fibrils which absorb the phenol from the aqueous solution. Water treated by the method does not give a characteristic phenol color when tested with ferric chloride.

Abstract: A process for preparing olefin polymer fibrils is disclosed. A high molecular weight ethylene polymer is dissolved in methylene chloride in a first zone that is heated to develop a superatmospheric pressure. The polymer solution is fed to a second zone which is maintained at atmospheric pressure. The polymer solution is discharged into vigorously stirred isopropanol to form fibrils. Polymer solvent is distilled from the resulting slurry. The fibrils are refined in the isopropanol slurry. The polymer solvent and the isopropanol are recycled to the process.

Abstract: Centrifugal spinning apparatus is provided for the manufacture of fibrils from hot viscous hydrocarbon solutions of olefin polymers having an intrinsic viscosity of at least 3.5. The apparatus consists of an impeller which rotates at high speed in a cylindrical cavity having a discharge port. The impeller has a plurality of blades whose narrow dimensions lie substantially in the plane of the impeller's rotation and whose tips come in close proximity to the inner peripheral surface of the cylindrical cavity. The blades are arranged in at least two substantially-identical sets. Within each set, the blades are offset substantially equidistant from one another, both in the rotational plane of the impeller and in the plane transverse thereto. Two inlet ports are provided in the peripheral surface of the cylindrical cavity to feed liquids to the cylindrical cavity, each of which port is narrow in a plane transverse to the plane of the impeller's rotation and extends over substantially the entire peripheral surface.

Abstract: A polymerization reaction product comprising a solution of a poly(1-alkene) and a hydrocarbon polymerization solvent is purified of Ziegler-Natta aluminum and titanium containing catalyst residue by treating with flux-calcined diatomite to deactivate and insolubilize the aluminum and titanium and filtering out the insolubilized aluminum and titanium.