Mitsui Chemicals, Inc.

Mitsui Petrochemical Industries, Ltd.

Satoru Ohtani

Shinji Abe

Tomohiro Arase

Hiroto Nishida

Yoshiaki Kikuchi

Ryoichi Yamamoto

Kenji Doi

Shotaro Matsuda

Ryouichi Yamamoto

Hiroshi Nishikawa

Teruhisa Kojima

Jun Iwama

Hisayoshi Watanabe

Fumio Hattori

Yoshinori Morita

Michiharu Sakata

Yutaka Haneda

Toshihiro Okano

Takahiro Mamyoda

Toshimi Hachimori

Takao Uetake

The olefinic polymer characterised in that the n-decane-soluble content thereof is 10% by weight or less and the content of a ligand having a cyclopentadienyl structure is 5 ppb by weight or less. The process for producing an olefinic polymer is a process of producing an olefinic polymer by (co)polymerizing olefins in a gas phase using a fluidized-bed reactor, the process comprising: a polymerization step of (co)polymerizing the olefins with allowing a saturated aliphatic hydrocarbon to exist in a concentration of 2 to 30 mol % in the fluidized-bed reactor and a ligand removing step involving a step of bringing the resulting (co)polymer into contact with a ligand-remover and a step of heating said (co)polymer which has been brought into contact with the ligand-remover.

Olefinic polymer and process for producing the same

In a gas phase olefin polymerization process using a fluidized bed vessel, an apparatus is employed having a device for measuring temperature or temperature distribution on the external wall surface of the vessel and a controlling means which predicts the progressive state of reaction inside the vessel, calculates the difference between the measured value and a target value determined beforehand and modifies polymerization conditions in relation thereto.

Fluidized bed polymerization apparatus and an olefin polymerization process

A process for producing a polyolefin according to the present invention comprises (co) polymerizing one or two or more &#x3b1;-olefins in a vapor phase in a fluidized-bed reactor, wherein the concentration of (A) a saturated aliphatic hydrocarbon in the fluidized bed reactor is 1 mol % or more and at least one compound selected from (B) an aliphatic amide and (C) a nonionic surfactant constituted only of carbon, oxygen and hydrogen atoms is made to exist in the reactor. The present invention can provide a process for producing a polyolefin, the process ensuring that the prevention of clogging caused by the generation of sheet or block polymers and a high efficiency of the production of a polyolefin due to good catalytic activity can be accomplished at the same time and also having superb continuous productivity.

Process for producing polyolefin

The process for producing an olefinic polymer comprises introducing a saturated aliphatic hydrocarbon in a liquid phase state and in a vapor phase state into the aforementioned fluidized-bed and (co)polymerizing in the condition that when the inside radius of the cylinder section of the fluidized-bed reactor is defined as a distance of 1, the relationship between the concentration (C) of the saturated aliphatic hydrocarbon put in a liquid state in the peripheral portion of the cylinder section at a relative distance of 0.7 to 1.0 from the center of the cylinder section as a start point and the concentration (C) of the saturated aliphatic hydrocarbon put in a liquid state in the center portion of the cylinder section at a relative distance less than 0.7 from the center fulfills the following equation: C&#x3e;Cat a place close to the upstream section of said gas distributing plate.

Process for producing olefinic polymer

The present invention provides a method for producing a polyolefin composition having a narrow composition distribution and is characterized in that when at least two olefins are copolymerized in the presence of a transition metal compound catalyst using at least two gas phase fluidized bed reactors, a saturated aliphatic hydrocarbon is allowed to exist in each reactor in a concentration from 0.1 to 30 mol %, and the ratio of the concentration (C ) of a saturated aliphatic hydrocarbon in a reactor of a second stage to the concentration (C ) of a saturated aliphatic hydrocarbon in a reactor of a first stage (C /C ) is 0.13 or more. Further, the present invention provides a method for producing a polyolefin composition by multi-stage polymerization, which can prevent sheeting in the reactor and can give a polyolefin composition stably with high productivity, and is characterized in that a saturated aliphatic hydrocarbon is allowed to exist in a transport line for transporting a polymer particle extracted from a fluidized bed reactor in the previous stage to a fluidized bed reactor in the subsequent stage at a concentration from 0.1 to 30 mol %.

Processes for producing polyolefin composition

In a gas phase olefin polymerization process using a fluidized bed vessel, an apparatus is employed having a device for measuring temperature or temperature distribution on the external wall surface of the vessel and a controlling means which predicts the progressive state of reaction inside the vessel, calculates the difference between the measured value and a target value determined beforehand an modifies polymerization conditions.

Fluidized bed polymerization apparatus having temperature distribution monitoring

A method of multistage gas phase polymerization is provided comprising performing polymerization of a feed gas mixture at least containing ethylene gas, an &agr;-olefin gas and hydrogen gas in an upstream fluid bed reactor to thereby produce a polymer powder, recovering the thus-produced polymer powder and performing further polymerization of the polymer powder in a downstream fluid bed reactor, the downstream fluid bed reactor being continuously connected to the upstream fluid bed reactor so that the polymer powder recovered from the upstream fluid bed reactor is introduced into the downstream fluid bed reactor, which method comprises the steps of: recovering polymer powder from the upstream fluid bed reactor, treating the recovered polymer powder so as to lower the content of &agr;-olefin gas and hydrogen gas therein by contacting the polymer powder with a stream of gas comprising ethylene or an inert gas, and introducing the treated polymer powder into the downstream fluid bed reactor. By this method, &agr;-olefin gas and hydrogen gas which inhibit the polymerization reaction in the downstream fluid bed reactor and which render regulation of desired polymer product properties difficult are removed from the polymer product prior to the downstream fluid bed reactor.

Method of multistage gas phase polymerization, apparatus therefor and device for reducing entrainment of subcomponents in polymer powder in apparatus for multistage gas phase polymerization

A method of terminating a gas phase polymerization of an olefin to be conducted subsequent to producing a polyolefin by feeding a gaseous olefin into a fluidized bed reactor to polymerize the gaseous olefin while holding solid particles containing a catalyst in a fluid state, said method comprising introducing a deactivator in the fluidized bed reactor through at least two deactivator introduction ports of the fluidized bed reactor so as to terminate the gas phase polymerization. The height of the fluidized bed is generally at least 3 m. The deactivator is preferably introduced through deactivator introduction ports disposed at heights Ha=-0.3 D to 0.3 D (a) and Hb=0.3 D to 2.0 D (b) (D is the inside diameter of the fluidized bed reactor (cm)). After the termination of the polymerization, the gas phase polymerization can directly be resumed. Formation of the product during the termination period can be minimized and the gas phase polymerization can rapidly be terminated even if the amount of the deactivator is small. Also, an apparatus which is suitable for the above termination and resumption of gas phase polymerization is provided.

Method of terminating gas phase polymerization of olefin, method of

A method of treating polyolefin comprises (i) a ligand-decomposition step of contacting polyolefin, which is obtained by the use of a transition metal compound containing ligands having cyclopentadienyl skeleton, with a ligand decomposer, such as water, oxygen, alcohol, alkylene oxide or peroxide, to decompose the ligands contained in the polyolefin, and (ii) a ligand-removal step of heating the polyolefin contacted with the ligand decomposer to remove the decomposed ligands from the polyolefin. According to this method, the residual ligands having cyclopentadienyl skeleton, which are contained in the polyolefin produced by the use of a transition metal compound containing ligands having cyclopentadienyl skeleton, are decomposed and removed from the polyolefin, whereby polyolefin diminished in odor development in the molding process can be obtained.

Method of treating polyolefin

In a gas phase olefin polymerization, an olefin is continuously fed to a fluid bed reactor in which a metallocene catalyst is present. At least one compound selected from water, alcohols and ketones is added in a specified amount simultaneously with the feeding of the olefin. Thus, an olefin polymer having a satisfactory drop second count index as defined by the below indicated formula is produced: ##EQU1## wherein t.sub.0 and t respectively represent a flow time measured in the flow test according to ASTM D-1775 of the olefin polymer obtained when none of the water, alcohols and ketones is incorporated in the reactor, and when at least one compound of water, alcohols and ketones is incorporated in the reactor. The flowability of the polymer formed in the reactor is excellent, so that blocking, bridging and the like do not occur during the gas phase polymerization. Thus, it is feasible to stably produce a (co)polymer having excellent particle properties in high yield for a prolonged period of time.

Process for gas phase polymerization of olefin

Drying of a solid polymer is disclosed in which a solid polymer obtained by polymerization (or a product of modification of the solid polymer) is contacted with a drying gas so that any solvent and/or unreacted polymerization feed materials remaining in the solid polymer are removed to thereby dry the solid polymer, and in which a gaseous polymerization feed material is used as the drying gas and contacted with the solid polymer to thereby dry the solid polymer (step i), and the resultant solid polymer is contacted with a drying gas which contains an inert gas (step ii). The drying gas can be recovered from the step (i) and part thereof can be recycled through a polymerization step as it is or be recycled, after cooling the drying gas to thereby remove any condensed components, to the step (i). Not only can the solid polymer be efficiently dried but also the solvent and unreacted polymerization feed materials recovered from the solid polymer can efficiently be recycled by the disclosed method.

Drying solid polymer apparatus

A gas distributor plate provided in a fluidized bed polymerization vessel which effects the gas phase polymerization of olefins, the gas distributor plate exhibiting excellent action for uniformly diffusing the gas flow in the fluidized bed zone. A gas distributor plate has a number of gas passage holes and is provided in a fluidized bed polymerization vessel which effects the gas phase polymerization of olefins, wherein when the inner radius of the straight drum portion of the polymerization vessel is denoted by 1, the holes perforated in the outer peripheral portion of the distributor plate at 0.7 to 1.0 from the center of the straight drum portion have an average diameter which is larger than the average diameter of the holes perforated in the inner peripheral portion of the distributor plate at smaller than 0.7 from said center. This makes it possible to uniformly and stably diffuse the gas flow in the fluidized bed zone in the polymerization vessel, to effectively prevent the formation of a dead zone, as well as to effectively prevent the polymer from adhering onto the wall surfaces of the polymerization vessel.

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Ichihara, Japan

Satoru Ohtani