Abstract: A 1,2-polybutadiene composition having an excellent reinforcing effect for rubber and synthetic resin materials including at least two polybutadiene components different in melting point from each other and each having, as a main structure, a 1,2-polybutadiene structure, produced by polymerizing a 1,3-butadiene-containing monomer in a water-containing polymerization system in the presence of a catalyst comprising a transition metal compound, an organic compound of one of the Group I to III metals, and one of carbon disulfide, phenyl isothiocyanate, and xanthic acid compounds, while adding a melting point-regulating agent comprising at least one of ketones, aldehydes, alcohols, esters, nitriles, sulfoxides, amides, and phosphoric acid esters in one or two or more separate adding operations or a continuous adding operation.

Abstract: A process for producing polybutadiene essentially consisted of syndiotactic-1,2-polybutadiene in an aqueous medium includes a step off polymerizing diene essentially consisted of 1,3-butadiene in the presence of: (A) a catalyst composition including (a) a transition metal compound, and (b) an organometallic compound which includes a metal selected from the elements consisting off groups 1, 2, 12, and 13 of Periodic Table; (B) an initiator comprising at least one component selected from a group consisting of carbon disulfide, an isothiocyanate compound, and a xanthogenic compound; and (C) an inert organic liquid having a density of at least 1.10, thereby resultant particles of syndiotactic-1,2-polybutadiene have a diameter up to 2 min.

Abstract: A 3,4,3',4'-substituted biphenyl compound represented by the general formula (II): ##STR1## wherein, one of R.sup.1 and R.sup.2 is a -CH.sub.3 group and the one other is a --COOR.sup.5 group, --COOH group, or --COCl group, and one of R.sup.3 and R.sup.4 is a -CH.sub.3 group and the other one is a --COOR.sup.5 group, --COOH group, or --COCl group, is produced by the steps of oxidatively coupling an o-toluic acid alkyl ester in the presence of a catalyst containing a mixture of palladium salts with 1,10-phenanthroline or .alpha.,.alpha.'-bipyridine, a chelating product of a palladium salt with 1,10-phenanthroline, or a chelating products of a palladium salt with .alpha.,.alpha.

Abstract: A thermotropic aromatic polyester comprising (a) an aromatic dicarbonyl ingredient comprising recurring aromatic units of the formulae (I) and/or (II): ##STR1## and, optionally, other recurring aromatic dicarbonyl units, (b) an aromatic dioxy ingredient comprising recurring aromatic units of the formula (III) ##STR2## wherein R.dbd.--H, C.sub.

Abstract: An N-(hydroxyphenyl)maleimide-isobutylene copolymer having the following repeating units: ##STR1## wherein R.sup.3 is a halogen atom or a lower alkyl group having 1-5 carbon atoms; l, m and n are numbers satisfying conditions of 0.01<n/(l+m).ltoreq.10 and 0.2<l/(l+m).ltoreq.1; and p is an integer of 0-4.

Abstract: A process for the preparation of an N-(hydroxyphenyl)-5 maleimide copolymer having the following repeating units: ##STR1## wherein R.sup.1 is hydrogen, an aryl group, an alkyl group having 1-16 carbon atoms or a cycloalkyl group; R.sup.2 is hydrogen or a lower alkyl group having 1-5 carbon atoms; R.sup.3 is a halogen atom or a lower alkyl group having 1-5 carbon atoms; l, m and n are numbers satisfying conditions of 0.01<n/(l+m).ltoreq.10 and 0.1<l/(l+m).ltoreq.1; and p is an integer of 0-4, comprising reaction of a copolymer of maleic anhydride and an unsaturated hydrocarbon and an aminophenol in an organic solvent.

Abstract: A process for producing polybutadiene of a high degree of polymerization having high 1,2 and cis-1,4 microstructure contents and a low trans-1,4 microstructure content, which comprises polymerizing 1,3-butadiene in the presence of a catalyst system composed of(1) a halogen-containing organoaluminum compound,(2) (a) a cobalt dithiocarbamate compound or (b) the reaction product of carbon disulfide, a secondary amine and a cobalt compound, and(3) water.The polybutadiene has for example(A) a 1,2 microstructure content of 7 to 50%,(B) a cis-1,4 microstructure content of at least 50%,(C) a trans-1,4-microstructure content of at most 5%,(D) an inherent viscosity, measured in toluene at 30.degree. C., of at least 1, and(E) a gel content of at most 0.3%.