According to an embodiment of the present invention, there is provided a novel fluorene-based compound and a photopolymerization initiator using the fluorene-based compound. The fluorene-based compound according to an embodiment of the present invention is represented by the general formula (1). A photopolymerization initiator having additionally high sensitivity can be provided by using the fluorene-based compound. In addition, a photopolymerization initiator that can impart additionally excellent characteristics can be provided by appropriately selecting, for example, a substituent.

Continuity compositions are provided as are methods of their preparation. The compositions comprise at least one metal carboxylate salt which is modified with at least one molten fatty amine. These compositions find advantageous use in olefin polymerization processes.

Catalyst component for the polymerization of olefins comprising Mg, Ti and an electron donor of formula (I) ##STR00001##
Where R.sub.1 and R.sub.2, independently, are selected from hydrogen and C.sub.1-C.sub.15 hydrocarbon groups, optionally contain an heteroatom selected from halogen, P, S, N, O and Si, which can be fused together to form one or more closed cycles and A is a bivalent bridging group.

The present invention relates to a preparation method of a highly active supported metallocene catalyst which can prepare a polyolefin of high bulk density. More specifically, the present invention provides a method of preparing the supported metallocene catalyst in which one or more metallocene catalysts are loaded on the silica carrier of which the inside is penetrated by more cocatalyst than the prior art and the outside is attached with a substantial amount of the cocatalyst. The catalyst according to the present invention can prepare a polyolefin polymer with improved bulk density and efficiency while maintaining its highly active catalytic characteristic.

The present disclosure relates to a vessel for separating, at a pressure of from 10 MPa to 50 MPa, a composition comprising liquid components and gaseous components into a liquid fraction and a gaseous fraction, wherein the separation vessel has a vertically arranged cylindrical shape, has at its top a manhole, which is surrounded by a thickened by a part of the separation vessel wall; and bears at least one bursting disc which is held by a bursting disc holder which is installed pressure-tight within a boring in the thickened part of the separation vessel wall.

Provided are ligand compounds containing two or more diphosphinoamine functional groups, where the two or more diphosphinoamine functional groups are linked by 4 carbon atoms, a catalyst system including the ligand compounds for olefin oligomerization, and a method for olefin oligomerization using the same. The catalyst system for olefin oligomerization according to the present invention has excellent catalytic activity, and yet, exhibits high selectivity to 1-hexene and 1-octene, thus enabling efficient preparation of alpha-olefin.

Provided are ligand compounds containing two or more diphosphinoamine functional groups, where the two or more diphosphinoamine functional groups are linked by 4 carbon atoms, a catalyst system including the ligand compounds for olefin oligomerization, and a method for olefin oligomerization using the same. The catalyst system for olefin oligomerization according to the present invention has excellent catalytic activity, and yet, exhibits high selectivity to 1-hexene and 1-octene, thus enabling efficient preparation of alpha-olefin.

The present disclosure generally relates to a process for separating polymeric and gaseous components of a reaction mixture obtained by high-pressure polymerization of ethylenically unsaturated monomers in the presence of free-radical polymerization initiators into a gaseous fraction and a liquid fraction in a separation vessel, wherein the filling level of the liquid fraction in the separation vessel is measured by a radiometric level measurement system comprising at least two radioactive sources and at least three radiation detectors, and the filling level is controlled by a product discharge valve which operates based on data coming from the level measurement system.

The present disclosure relates to a process for separating polymeric and gaseous components of a reaction mixture obtained by high-pressure polymerization of ethylenically unsaturated monomers in the presence of free-radical polymerization initiators into in a gaseous fraction and a liquid fraction, wherein the separation is carried out at a pressure of from 15 MPa to 50 MPa and a temperature of from 120 C. to 300 C. in a separation vessel which has a vertically arranged cylindrical shape with a ratio of length to diameter L/D of from 4 to 10 and which is equipped with an inlet pipe which extends vertically from the top into the separation vessel; and the ratio of the inner diameter of the inlet pipe at its lower end and the inner diameter of the separating vessel in its cylindrical part is in the range of from 0.2 to 0.4.

A method of making a low-fluoride reactive PIB composition includes (a) providing a modified C4 feedstock by way of blending a mixed C4 feedstock with a second feedstock having a lower LB/IsoB ratio; or providing a C4 feedstock with an LB/IsoB index of less than 10%; (b) feeding the modified C4 feedstock or the C4 feedstock with an LB/IsoB index of less than 10% to a CSTR with a homogeneous catalyst comprising BF.sub.3 and a modifier selected from alcohols, ethers and mixtures thereof; (c) polymerizing the modified C4 feedstock or the C4 feedstock with an LB/IsoB index of less than 10% in the reactor while maintaining the reactor at a temperature above 15 C. and utilizing a residence time less than 45 minutes to produce a crude PIB composition in a polymerization mixture; and (d) recovering a purified PIB composition from the polymerization mixture having a molecular weight, Mn, from 250 to 5000 Daltons and an alpha vinylidene content of at least 50 mol %. The crude PIB composition suitably has a fluoride content of less than 100 ppm and the purified PIB composition has a fluoride content of less than 20 ppm in preferred embodiments. In the most preferred embodiments, ammonium salts are used to neutralize the catalyst and fluoride salts are sublimed from the product at elevated temperatures.