Abstract: A process for producing an aromatic polycarbonate is described, which comprises melt-polycondensing an aromatic diol compound with a diaryl carbonate compound in the presence of an interesterification catalyst, said interesterification catalyst comprising a quaternary phosphonium salt compound represented by formula (II): ##STR1## wherein R.sup.3, R.sup.4, R.sup.5, and R.sup.6 each independently represent an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a cycloalkyl group, and X.sup.l- is an anion selected from the group consisting of a carbonate ion, a phosphate ion, and a tetrahydroxyboron ion, with the letter l indicating the valency of X.

Abstract: A process for producing an aromatic polycarbonate having a weight average molecular weight of from 7,000 to 60,000 is disclosed, comprising melt polycondensing an aromatic diol compound (e.g., bisphenol A) and a diaryl carbonate compound (e.g., diphenyl carbonate) in the presence of a combination of (a) an alkali metal compound and (b) a phosphonium hydroxide compound (e.g., tetraethylphosphonium hydroxide) as an interesterification catalyst. The aromatic polycarbonate has improved heat resistance and hue.

Abstract: A process for producing an aromatic polycarbonate with improved heat resistance comprising melt polycondensing an aromatic diol compound and a carbonic acid diester compound in the presence of an interesterification catalyst and in the co-presence of an organosilicon compound.

Abstract: A copolymer of an .alpha.-olefin with an aromatic diolefin such as divinylbenzene produced by means of Ziegler-Natta polymerization and having a vinylphenyl moiety is subjected to polymerization with an ethylenically unsaturated monomer by means of anion polymerization or free radical polymerization, whereby a graft-modified .alpha.-olefin copolymer is obtained.

Abstract: An aromatic polycarbonate of improved color value and high molecular weight is obtained by the addition of phosphorous acid and/or a phosphorous ester to the melt polycondensation reaction medium containing aromatic diol, carbonate diester and a metal-containing compound as ester interchange catalyst during the polycondensation reaction

Abstract: A process for the preparation of olefin polymers, which comprises polymerizing an olefin in the presence of a catalyst which comprises: (A) a solid catalyst component obtained by contacting a magnesium dihalide such as MgCl.sub.2 with a titanium tetra-alkoxide such as Ti(O-nBu).sub.4 and then with a polymeric silicon compound having a structure represented by the formula ##STR1## wherein R stands for a hydrocarbon residue such as CH.sub.3, and contacting the obtained solid component with a halogen compound of silicon such as SiCl.sub.4 or with a halogen compound of silicon such as SiCl.sub.4 and a halogen compound of titanium such as TiCl.sub.4, (B) an organoaluminum compound such as Al(Et).sub.3 ; and (C) an organic silicon compound having an Si--O--C linkage such as PhSi(OEt).sub.3. According to this process, a polymer having a high stereoregularity, a narrow particle size distribution and a high bulk density can be obtained in a high yield with a high efficiency.

Abstract: A copolymer of an .alpha.-olefin with an aromatic diolefin such as divinylbenzene produced by means of Ziegler-Natta polymerization and having a vinylphenyl moiety is subjected to polymerization with an ethylenically unsaturated monomer by means of anion polymerization or free radical polymerization, whereby a graft-modified .alpha.-olefin copolymer is obtained.

Abstract: Disclosed is a polymer alloy consisting essentially of a composition of a polyphenylene ether, a crystalline propylene resin, and an alkenyl aromatic monomer modified propylene-dialkenylbenzene compound copolymer. The composition excels in heat resistance and resistance to oils.

Abstract: A catalyst component for polymerization of .alpha.-olefins is produced by causing mutual contact of:(A) a magnesium halide containing solid;(B) an electron donating compound, having the structural site as represented by the formula show below in its molecule: ##STR1## and (C) a titanium halide. The catalyst thus produced has high polymerization activity and is capable of producing polymers having excellent stereoregularity.

Abstract: A process for preparing a titanium trichloride composition comprises the steps of:(1) reducing titanium tetrachloride with oaganoaluminum compounds to produce a titanium trichloride composition having a .beta.-crystal structure;(2) heat treating the resulting titanium trichloride having a .beta.-crystal structure and subsequently pulverizing the heat-treated titanium trichloride in the presence or absence of titanium tetrachloride to produce a titanium trichloride composition containing substantially no titanium trichloride having a .beta.-crystal structure;(3) treating the pulverized titanium trichloride composition with a complexing agent; and(4) treating the resulting titanium trichloride composition with a compound selected from the group consisting of metal halide compounds having Lewis acidity and interhalogen compounds.

Abstract: A catalyst component, which is to be combined with an organoaluminum component to form a Ziegler catalyst for olefin polymerization, is produced by treating (1) a solid composition resulting from a process of combining a magnesium halide such as magnesium chloride, an electron donor compound such as ethyl benzoate and a titanium halogen compound such as titanium tetrachloride with (2) an interhalogen compound or a halogen such as iodine trichloride.