The present invention deals with a process of polymerising at least one olefin in a fluidised bed in a fluidised bed polymerisation reactor comprising a top zone, a middle zone in direct contact and below, a bottom zone in direct contact with and below the middle zone and wherein the reactor does not comprise a fluidisation grid. The process comprises passing a stream comprising the fluidisation gas and polymer particles into a separation step and withdrawing a stream comprising the polymer particles from the separation step and returning it to the polymerisation reactor. The process comprises adding a support gas stream to the stream comprising the polymer particles downstream of the separation step.

The present disclosure relates to a transparent thermoplastic resin and a method of preparing the same. More particularly, the present disclosure provides a transparent thermoplastic resin that provides superior transparency without generation of flow marks on a surface, and does not exhibit cracks or a whitening phenomenon during processing due to superior whitening resistance, particularly superior whitening resistance at low temperature, a method of preparing the transparent thermoplastic resin, and the like.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

The present invention relates to a process for producing cycloalkenamer-containing compositions and to such cycloalkenamer-containing compositions. The invention further relates to the use of these cycloalkenamer-containing compositions in the field of packaging materials, especially for food and drink.

The present invention relates to a solvent separation apparatus and a waste heat utilization method, and the solvent separation apparatus and the waste heat utilization method according to the present application can reduce the used amount of cooling water and the used amount of steam, in a process of separating a polymer and a solvent.

A method for the removal of unreacted olefin monomer(s) from polyolefin product particles of an olefin polymerization reaction, the method including: contacting the polyolefin product particles with a countercurrent flow of a purge gas in a purge vessel under conditions allowing diffusion of unreacted monomer and other gaseous substances from the polyolefin product particles into the countercurrent flow of the purge gas to produce purged particles; wherein the velocity of the purge gas exceeds 50% of the calculated minimum fluidization velocity of the polyolefin product particles in the purge vessel (U.sub.mf), is provided.

A system and method for a first reactor to produce a transfer slurry having a first polyolefin polymerized in the first reactor, a heat-removal zone to remove heat from the transfer slurry, and a second reactor to receive the transfer slurry cooled by the heat-removal zone, the second reactor to produce a product slurry having a product polyolefin which includes the first polyolefin and a second polyolefin polymerized in the second reactor.

A production process for production of water absorbing polymer particles, including drying an aqueous polymer gel in a belt drier with a conveyor belt having a drier setup in the interior, in which drying air in the interior of the drier setup is conducted in countercurrent counter to the conveying direction and the interior of the drier setup is kept substantially at a reduced pressure relative to the ambient pressure outside the drier setup, and the interior has and/or forms a pressure zone, and is especially divided into a number of pressure zones.

The present invention relates to a method of reducing the entrainment of polymer in the polymer-lean liquid phase in a separator, comprising the steps of: (i) Selecting the diameter of the polymer droplets in the polymer solution entering the separator; (ii) Determining the traveling time of the polymer droplets in the separator; and (iii) Adjusting the residence time of the polymer-dense phase in the separator to be at least the traveling time of the polymer droplets, a solution polymerization process using said method for reducing the entrainment of polymer in the polymer-lean liquid phase in the separator and the use of said method for determining the minimum residence time of the polymer solution in the separator required to ensure efficient separation of a polymer solution into a polymer-lean phase and a polymer-rich phase.

Provided is a water absorbent resin that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having a higher liquid permeability and a higher water absorbing speed. Further provided is a water absorbent resin powder that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having increased in absorbency of a liquid and in heat retaining property. A gel grinding device to be used to produce a water absorbent resin, includes: a screw; a feed opening; an extrusion opening; a porous plate; and a barrel, the barrel including a return preventing member provided on an inner surface thereof, and the return preventing member satisfying at least one of specific parameters.