Sumitomo Chemical Company, Limited

Kiyoshi Matsuyama

Akinobu Shiga

Masahiro Kakugo

Yukio Naito

Takatoshi Suzuki

Seiichiro Ima

Mamoru Asada

Hiroyuki Ogawa

Kenji Ochi

Katsuyoshi Yamashita

Akira Nunose

Takuya Suzaki

Kazuyoshi Imai

Shozi Ishikawa

Seizi Hirata

Takeshi Chigusa

Tsutomu Ogura

Hitoshi Hashimoto

Masaharu Nishioka

A polymer slurry formed by polymerizing ethylene or propylene optionally with other olefin monomer copolymerizable therewith in a hydrocarbon solvent such as propylene, propane, butane, etc., is continuously or intermittently supplied to a filter having a filtering surface on which a slight quantity of polymer particles are retained. Most of the hydrocarbon solvent is recovered by passing through the filtering surface, and the polymer particles are overflown from the filter to recover as a wet cake. By the use of such a specific filter, the quantity of the solvent to be vaporized can be greatly reduced.

Finishing method of polymer slurry

A particulate polyolefin molding material is disclosed. The material is comprised of a particulate polyolefin particle having a bulk density of 0.45 g/cc or more and a mean particle size of 150 to 2,000.mu., and a layer comprising a compounding additive and a binder formed on the surface of the particle. The material can be used in producing molded articles without first forming the material into pellets as is conventionally done.

Particulate polyolefin molding material

In a process for producing a homopolymer or a copolymer of propylene comprising polymerizing propylene or copolymerizing propylene and at least one other unsaturated hydrocarbon monomer in liquid propylene using a catalyst system containing activated titanium trichloride (a) and an organoaluminum compound (b), the activated titanium trichloride (a) being prepared by reducing titanium tetrachloride with an organoaluminum compound followed by activation, to produce a polymer slurry; introducing the polymer slurry produced into the top of a counter-current washing tower; and washing the polymer slurry by counter-currently contacting the polymer slurry with liquid propylene introduced into the bottom of the washing tower, the improvement which comprises purifying the homopolymer or copolymer of propylene by feeding an epoxide in a molar amount of about 1 to about 15 times the molar amount of the total of activated titanium trichloride (a) and organoaluminum compound (b), to a part of said washing tower, thereby deactivating the catalyst and removing the catalyst residue and the homopolymer or copolymer of propylene dissolved in the polymer slurry.

Process for the production of purified propylene homopolymers or

Granules containing 60 wt. % or more filler, having such particle size distribution that 90 wt. % or more granular particles have a particle size of (1/3)d.sub.50.sup.b to 3d.sub.50.sup.b (d.sub.50.sup.b : mean particle size of the granules), and being produced by blending (a) 60 to 90 parts by weight of a filler having a mean particle size of 0.05 to 100.mu., (b) 5 to 35 parts by weight of crystalline polyolefin powder having a mean particle size (d.sub.50.sup.a) of 150 to 1,000.mu. and having such particle size distribution that 90 wt. % or more particles thereof have a particle size of (1/2)d.sub.50.sup.a to 2d.sub.50.sup.a, (c) 5 to 35 parts by weight of a binder having a melting point lower than that of said crystalline polyolefin powder by a least 10.degree.C., and optionally, (d) a compounding additive, at a temperature lower than the melting point of the crystalline polyolefin powder and higher than the melting point of the binder, is disclosed.

Granules with a narrow particle size distribution comprising filler,

In a process for producing polypropylene comprising polymerizing propylene in the presence of hydrogen and a catalyst system comprising (A) titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound and reacting the reduced solid with an ether represented by the formula:

Propylene-ethylene copolymer having improved stretchability

In polymerizing an olefin, for example, in a polymerization reactor with a reflux condenser, a gas mixture withdrawn from the polymerization reactor is first washed before it reaches the heat transfer surface of the reflux condenser to remove active catalyst particles and polymer particles entrained therein and then condensed to obtain a condensed liquid, and the condensed liquid is returned to the polymerization reactor whereby the heat generated in the polymerization reactor is efficiently removed without causing any clogging of pipes, etc.

Method for the heat removal from polymerization reactor

In a process for producing propylene copolymer containing about 80 to 99 mol % propylene and about 1 to 20 mol % ethylene and/or an .alpha.-olefin having 4 to 18 carbon atoms using a Ziegler-Natta catalyst, the improvement which comprises said Ziegler-Natta catalyst comprising:

Process for producing propylene copolymer

Process for producing a propylene-ethylene copolymer having improved

A molded product of polypropylene having an isotactic pentad fraction of the boiling heptane insoluble portion of at least about 0.955 and a boiling heptane solubles content of about 2.0 to 9.0% by weight. The molded products include a stretched film, insulating materials for electrical equipment, etc.

Molded products of polypropylene

A process for producing a propylene polymer or copolymer which comprises polymerizing (a) propylene or (b) a mixture of propylene and another unsaturated hydrocarbon monomer in liquid propylene in the presence of a catalyst system of

Process for producing propylene polymer or copolymer

A slurry containing polymer particles having an average particle diameter of 0.1 to 1 mm suspended therein is discharged smoothly from a discharge valve without valve clogging by operating the valve such that the degree of valve opening is set within a range II for a valve operating time t.sub.1 and within a range III for a valve operating time t.sub.2 ; the time t.sub.1 being from 5 to 60 seconds, the time t.sub.2 being from 1 to 10 seconds, the range II being a range of valve openings at which the valve is gradually clogged with the polymer particles discharged, and the range III being a range of valve openings at which the valve permits continuous discharge without clogging.

Method of discharging slurry by varying valve openings

In a process for the recovery of an atactic polymer which comprises heating liquid propylene containing the dissolved atactic polymer at a gauge pressure of 13 to 40 kg/cm.sup.2 in a vaporizer to vaporize the propylene, and separating the atactic polymer from the vaporized propylene thereby recovering the polymer in a molten state, the improvement comprising maintaining the vaporization temperature of propylene at 45.degree. C. to 90.degree. C. and the temperature of a heating medium for the vaporizer at 60.degree. C. to 150.degree. C. According to this process, a long run can be used in the recovery of the atactic polymer.

Process for the recovery of atactic polymers

A process for purifying propylene homopolymers or copolymers which comprises:

Process for the purification of highly crystalline polyolefins

In a process for producing a propylene homopolymer or copolymer which comprises polymerizing propylene or copolymerizing propylene and at least one other unsaturated hydrocarbon monomer in liquid propylene using a catalyst comprising activated titanium trichloride and an organo-aluminum compound, the activated titanium trichloride being prepared by reducing titanium tetrachloride with an organo-aluminum compound followed by activation, introducing the polymer slurry produced into the top of a counter-current washing tower, and washing the slurry by bringing the slurry into counter-current contact with liquid propylene which is introduced into the bottom of the washing tower, the improvement which comprises refining the homopolymer or copolymer of propylene by feeding (a) an alcohol having 3 to 8 carbon atoms in a molar amount of about 0.1 to about 10 times the molar amount of the organo-aluminum compound in the slurry, or (b) a mixture of an alcohol having 3 to 8 carbon atoms and an epoxide, the molar amount of the alcohol being about 0.1 to about 10 times the molar amount of the organo-aluminum compound in the slurry and the molar amount of the epoxide compound being about 0.1 to about 3 times the molar amount of the organo-aluminum compound in the slurry, to a part of the washing tower, thereby simultaneously deactivating the catalyst and removing the catalyst and the propylene homopolymer or copolymer dissolved in the polymer slurry.

Process for refining a homopolymer of copolymer of propylene

A process for producing a homopolymer of propylene or a copolymer of propylene which comprises polymerizing propylene or a mixture of propylene and another unsaturated hydrocarbon monomer such as ethylene in liquid propylene, in the presence of a catalyst system consisting essentially of (a) an activated titanium compound obtained by reducing titanium tetrachloride with an organic aluminum compound and activating the resulting titanium compound and (b) an organic aluminum compound to produce a polymer slurry, introducing the polymer slurry into an upper part of a counter-current washing zone, such as a washing tower, and counter-currently contacting the polymer slurry with liquid propylene which is introduced into a lower part of the washing zone, whereby the polymer and catalyst residues dissolved in the polymer slurry are removed.

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Niihama, Japan

Kiyoshi Matsuyama