Abstract: Styrene homo-or-co- polymers, the stereoregularity of which is mainly syndiotactic are disclosed, having repeating unit or two or more different repeating units defined by a general formula (I): ##STR1## wherein each R may be the same or different. And a method of preparation of syndiotactic copolymers wherein there are two different repeating units represented by formula (I); wherein the polymerization is carried out with a catalyst comprising (a) a titanium compound and (b) a contact product of an organoaluminum compound and a condensing agent such as water.

Abstract: The present invention relates to a styrene-based resin composition comprising a styrene-based polymer having mainly a syndiotactic configuration and a specified antioxidant, a fibrous molding or extrusion produced by spinning a syndiotactic styrene resin composition and a molding produced by shaping and/or spinning, and stretching said resin.

Abstract: The present invention provides a process for producing a homogeneous aluminoxane solution wherein an alkylaminoxane (A) obtained by reacting an organoaluminum compound with water and removing a solid residue by filtration is reacted with an organoaluminum compound (C) in the presence of an aromatic hydrocarbon solvent (B). According to the present invention, the gel-free homogeneous aluminoxane solution can be obtained and the catalytic activity thereof is not deteriorated during the storage.

Abstract: An amorphous and excellently moldable styrene-based polymer having a syndiotactic structure can be obtained when a styrene-based polymer having a substantially syndiotactic structure is dissolved in a solvent followed by separation and recovery of the polymer from the solution or melt thereof is quenched. Shaping the same gives various kinds of shaped articles having excellent mechanical strengths and heat resistance. Physical properties of the shaped articles can be further improved by a modification treatment.

Abstract: Disclosed is a process for producing a styrene-based polymer by contacting a styrene-type monomer with alkylaluminoxane previously, adding a transition metal compound and then polymerizing of the styrene-type monomer.By using the process of the present invention, polymerization of a styrene-type monomer can be carried out with a high catalytic activity, and a styrene-based polymer having high syndiotacticity can be obtained with high efficiency.The sytrene-based polymer having a high degree of syndiotactic configuration of this invention has various excellent physical properties such as heat resistance and chemical resistance, and can be effectively and widely utilized for various applications.

Abstract: A catalyst for producing styrene-based polymers having mainly syndiotactic configuration which comprises (A) a titanium compound and (B) a contact product of a methyl group-containing organoaluminum compound and water, wherein the contact product (B) has a high magnetic field component of not more than 50% in the methyl proton signal region due to an aluminum-methyl group (Al-CH.sub.3) bond as determined by the proton nuclear magnetic resonance absorption method.

Abstract: A novel crystalline vinylcyclohexane-based polymer having a repeating unit represented by the general formula: ##STR1## (wherein all the symbols are as defined in the appended claims), a degree of polymerization of at least 5 and mainly syndiotactic configuration. This polymer is produced by hydrogenating a styrene-based polymer having a repeating unit represented by the general formula: ##STR2## (wherein all the symbols are as defined in the appended claims), a degree of polymerization of at least 5 and mainly syndiotactic configuration.

Abstract: A process for production of styrene polymers is disclosed, comprising polymerizing styrene monomers by the use of a catalyst comprising (a) a titanium compound and (b) a contact product of an organoaluminum compound and a condensing agent, and further in the presence of hydrogen. The styrene polymers produced by the present process have a stereo structure that substituent groups are mainly in the syndiotactic configuration. Thus the styrene polymers have high heat resistance and high solvent resistance as compared with atactic polystyrene commonly used and are useful as materials for production of articles for which high heat resistance and high solvent resistance are required.

Abstract: A process for producing styrene-based polymers having mainly syndiotactic configuration in the presence of a catalyst comprising (A) a titanium compound and (B) a contact product of a methyl group-containing organoaluminum compound and water, wherein the contact product (B) has a high magnetic field component of not more than 50% in the methyl proton signal region due to an aluminum-methyl group (Al--CH.sub.3) bond as determined by the proton nuclear magnetic resonance absorption method.According to this process, styrene-based polymers having mainly syndiotactic configuration can be efficiently and economically produced.

Abstract: Disclosed is a process for producing propylene oligomers at high selectivities which comprises oligomerizing propylene in the presence of a catalyst comprising an alkyl substituted cyclopentadienyl compound of zirconium and/or hafnium and a condensation product of organoaluminum compound and water.

Abstract: A process for production of styrene polymers of high syndiotactic configuration is disclosed, comprising polymerizing styrene or styrene derivatives by the use of a catalyst comprising: (A) a titanium compound, e.g., at least one compound selected from those represented by the formulae: TiR.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c X.sup.1.sub.4 -(a+b+c) and TiR.sup.1.sub.d R.sup.2.sub.e X.sup.1.sub.3-(d+e) (all the symbols are as defined in the appended claims); and (B) a contact product of an organoaluminum compound and a condensation agent, e.g., a product resulting from modification of trimethylaluminum with water. Because of such high syndiotactic configuration, the styrene polymers are greater in thermal resistance and solvent resistance than conventional atactic polystyrene.