Abstract: A method for preparing a propylene (co)polymer having a substantially high syndiotactic structure and a desired molecular weight which comprises the step of (co)polymerizing propylene or propylene and a small amount of another olefin by the use of a transition metal compound catalyst having asymmetric ligands in the presence of a specific internal olefin.

Abstract: A method for preparing a decomposable film which comprises the steps of dispersing poly-.alpha.-methylstyrene or a polyalkylene carbonate in water, or preferably dissolving poly-.alpha.-methylstyrene or the polyalkylene carbonate in a solvent, dispersing the resulting solution in water, vaporizing the solvent so that the content of the solvent may be in the range of from 20 to 100% by weight based on the weight of poly-.alpha.-methylstyrene or the polyalkylene carbonate, applying the resulting aqueous emulsion, and then drying the same; and a method for preparing a metal film having a flat surface which comprises the steps of depositing a metal on the surface of the decomposable film, and then treating the film at a temperature higher than the decomposition temperature of the film.

Abstract: A syndiotactic graft copolymer is here disclosed in which a radical polymerizable unsaturated compound is grafted on a propylene homopolymer or copolymer, and this graft copolymer is obtained by heating a homopolymer having a substantially syndiotactic structure of propylene or a copolymer having a substantially syndiotactic structure of propylene and another .alpha.-olefin and a radical polymerizable unsaturated compound such as an unsaturated carboxylic acid or an unsaturated silane in the presence of a radical initiator up to the decomposition temperature or more of the radical initiator. This kind of graft copolymer can be used as a composition for adhesion. The graft copolymer in which the radical polymerizable unsaturated compound is a hydrolyzable unsaturated silane can be converted into a crosslinked polymer by heating in the presence of water, and it can also be converted into a water-crosslinkable resin composition by adding various additive thereto.

Abstract: A syndiotactic graft copolymer is here disclosed in which a radical polymerizable unsaturated compound is grafted on a propylene homopolymer or copolymer, and this graft copolymer is obtained by heating a homopolymer having a substantially syndiotactic structure of propylene or a copolymer having a substantially syndiotactic structure of propylene and another .alpha.-olefin and a radical polymerizable unsaturated compound such as an unsaturated carboxylic acid or an unsaturated silane in the presence of a radical initiator up to the decomposition temperature or more of the radical initiator. This kind of graft copolymer can be used as a composition for adhesion. The graft copolymer in which the radical polymerizable unsaturated compound is a hydrolyzable unsaturated silane can be converted into a crosslinked polymer by heating in the presence of water, and it can also be converted into a water-crosslinkable resin composition by adding various additive thereto.

Abstract: A polyimide comprising a requisite structural unit having one or more recurring structural units of the formula: ##STR1## such as the structural units of the formula ##STR2## The polyimide can have an extremely low dielectric constant and is colorless, transparent and excellent in processability and heat resistance, and also provides an aromatic diamine which is useful as a raw material monomer of the polyimide or a raw material of other various engineering plastics.

Abstract: A radiation-resistant polypropylene resin composition is disclosed which comprises a polypropylene having a substantially syndiotactic structure, and if desired, a phosphorus-containing anti-oxidant, an amine-containing anti-oxidant and/or a nucleating agent. Molded articles obtained from this resin composition can be utilized as containers for foods and medicines, and their physical properties scarcely deteriorate during sterilization by radiation.

Abstract: An .alpha.-olefin-alkenylsilane copolymer having steric regularity in which the side chains in the .alpha.-olefin unit substantially have the steric regularity, the content of alkenylsilane units is from 0.01 to 50% by weight, and the intrinsic viscosity measured in a tetralin solution at 135.degree. C. is 0.01 or higher. A method for preparing the above copolymer comprises the step of copolymerizing an .alpha.-olefin having 3 to 25 carbon atoms with an alkenylsilane in the presence of a catalyst comprising an aluminoxane and a transition metal compound containing a cyclopentadiene group or its derivative as a ligand.

Abstract: A syndiotactic graft copolymer is here disclosed in which a radical polymerizable unsaturated compound is grafted on a propylene homopolymer or copolymer, and this graft copolymer is obtained by heating a homopolymer having a substantially syndiotactic structure of propylene or a copolymer having a substantially syndiotactic structure of propylene and another .alpha.-olefin and a radical polymerizable unsaturated compound such as an unsaturated carboxylic acid or an unsaturated silane in the presence of a radical initiator up to the decomposition temperature or more of the radical initiator. This kind of graft copolymer can be used as a composition for adhesion. The graft copolymer in which the radical polymerizable unsaturated compound is a hydrolyzable unsaturated silane can be converted into a crosslinked polymer by heating in the presence of water, and it can also be converted into a water-crosslinkable resin composition by adding various additive thereto.

Abstract: The present invention relates to a process for the preparation of a thermoplastic resin composite comprising conducting polycondensation of a monomer material in a solution of an organic solvent containing an organic solvent soluble polymer to form an aromatic condensation polymer which is insoluble in said organic solvent and a thermoplastic resin composite prepared by the process.

Abstract: A thermoplastic resin composition comprise 99.9.about.50 parts by weight of one or more thermoplastic resin selected from the group consisting of aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyethersulfone and aromatic polyether ketone and 0.1.about.50 parts by weight of one or more liquid crystal type aromatic polyimide having recurring structural units represented by the formula (1): ##STR1## wherein R.sub.1 .about.R.sub.5 is a hydrogen atom, fluorine atom, trifluoromethyl, methyl, ethyl or cyano and may be the same or different, and R is a tetravalent radical having 6.about.27 carbon atoms and being selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member.

Abstract: Disclosed herein is a polypropylene resin composition of a high syndiotacticity comprising a substantial homopolymer of propylene, in which the ratio of the intensity of the peak attributable to the syndiotactic pentad bonds to the sum of the intensities of all the peaks attributable to the methyl groups in the spectrum of the methyl groups measured by .sup.13 C-NMR is 0.7 or more, and a copolymer of ethylene and propylene, and a preparation process thereof.

Abstract: A method for preparing a molded article of a crosslinked polyolefin which comprises the steps of bringing a composition comprising a copolymer of an alkenylsilane and an olefin and a compound having at least two unsaturated bonds into contact with a catalyst selected from the group consisting of salts of rhodium, alkoxy compounds and metallocene compounds of metals in the group IVa of the periodic table, combinations of the metallocene compounds and organic metal compounds, and then molding the composition, or carrying out the contact simultaneously with the molding, or molding the composition, and then bringing the molded article into contact with the catalyst, and if necessary, further heating the molded article to accelerate a crosslinking reaction.The molded article of the crosslinked polyolefin obtained by the method of the present invention has a high crosslinking density and is excellent in mechanical properties, solvent resistance and heat resistance.

Abstract: The heat resistant adhesive of the invention comprises polyamic acid and/or polyimide which are prepared by using 1,3-bis(3-aminophenoxy)benzene as an aromatic diamine component and 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride and/or 3,3',4,4'-diphenylethertetracarboxylic dianhydride as tetracarboxylic acid dianhydrides, and further by blocking the polymer chain end with dicarboxylic anhydride or a monoamine compound; or comprises a polyimide solution containing the polyimide in a good solvent.The adhesive of the invention is a heat-resistant adhesive capable of adhering under mild temperature/mild pressure conditions. The adhesive of polyimide solution can provide desired adhesion by simple procedures such as applying to the adherend and heating under pressure and exhibits excellent adhesive strength.

Abstract: A syndiotactic polypropylene resin composition comprising a polypropylene having a substantially syndiotactic structure and a nucleating agent. The syndiotactic polypropylene may be a homopolymer of the propylene, a copolymer of the propylene and a smaller amount of another olefin or a mixture of the above-mentioned (co)polymer and an isotactic polypropylene. The resin composition preferably has a higher crystallization temperature than a polypropylene containing no nucleating agent by 5.degree. C. or more, as measurement is made by a differential scanning thermal analysis.

Abstract: Copolymers of butene-1 and propylene, having specific physical properties and substantially a syndiotactic structure; and easily heat-sealable polypropylene resin compositions comprising 5-50 parts by weight of one of the copolymers and 95-50 parts by weight of a stereoregular crystalline propylene-ethylene copolymer or propylene ethylene-C.sub.4-12 -.alpha.-olefin copolymer having specific compositions and melt flow index.

Abstract: A method for molding a polypropylene or a propylene copolymer having a syndiotactic structure which comprises the steps of melting, molding, if desired, quenching and then stretching a propylene homopolymer or a copolymer of propylene and a small amount of ethylene or another .alpha.-olefin which has a substantially syndiotactic structure, or a mixture of the same and a small amount of a polypropylene having a substantially isotactic structure. The molded and stretched article can be heated at a temperature of a molding temperature or more, while a load is applied to the article. Furthermore, the molded and stretched article, if desired, can be treated with a hydrocarbon vapor, while a load is applied to the article. The molded article obtained by the method of the present invention has a novel crystalline structure.

Abstract: The heat resistant adhesive of the invention comprises polyamic acid and/or polyimide which are prepared by using 1,3-bis(3-aminophenoxy)benzene as an aromatic diamine component and 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride and/or 3,3',4,4'-diphenylethertetracarboxylic dianhydride as tetracarboxylic acid dianhydrides, and further by blocking the polymer chain end with dicarboxylic anhydride or a monoamine compound; or comprises a polyimide solution containing the polyimide in a good solvent.The adhesive of the invention is a heat-resistant adhesive capable of adhering under mild temperature/mild pressure conditions. The adhesive of polyimide solution can provide desired adhesion by simple procedures such as applying to the adherend and heating under pressure and exhibits excellent adhesive strength.

Abstract: According to the present invention, molded articles can be provided in which a melting point attributed to a syndiotactic polypropylene and measured at a temperature rise rate of 10.degree. C./minute by differential scanning thermal analysis is indicated by a substantially single peak, the aforesaid molded articles being obtained by heating, melting and molding a substantially syndiotactic homopolymer of propylene, a substantially syndiotactic copolymer of propylene and a small amount of another olefin, or a mixture of these polymers and a small amount of a substantially isotactic polypropylene, and then subjecting the molded products to a heat treatment. Furthermore, a method for preparing the above-mentioned molded articles is also provided. The molded articles have high stiffness and impact resistance.

Abstract: There is disclosed a homoplymer of an alkenylsilane having a syndiotactic structure and a copolymer of the alkenylsilane and an .alpha.-olefin. The polymer and the copolymer can be prepared by subjecting the alkenylsilane or the alkenylsilane and the .alpha.-olefin to addition polymerization in the presence of a transition metal compound having asymmetirically interconnected ligands or preferably in the presence of the transition metal compound and aluminoxane. The polymer and the copolymer can be used as a nucleating agent for a crystalline polypropylene.

Abstract: A substantially syndiotactic propylene copolymer which comprises propylene and at least one cyclic diolefin having 6 to 25 carbon atoms or an alkadiene having 6 to 25 carbon atoms and at least one terminal double bond, in the .sup.13 C-NMR spectrum of the copolymer measured in a 1,2,4-trichlorobenzene solution, a peak intensity observed at about 20.2 ppm as the reference of tetramethylsilane at 0.0 ppm being 0.5 or more of the total peak intensity attributed to methyl groups of propylene; the content of the cyclic diolefin or the alkadiene being from 0.01 to 20 mol %; the intrinsic viscosity [.eta.] of the copolymer measured in a tetralin solution at 135.degree. C. being from 0.1 to 10 dl/g.This copolymer can contain an .alpha.-olefin other than propylene, particularly ethylene.