Abstract: There are disclosed dibenzofuran amorphous polymer comprising a recurring unit represented by following formula (II) and having a molecular weight giving a reduced viscosity of at least 0.2 dl/g as measured in the form of a 0.5% (W/V) solution in N-methyl-pyrrolidone at 25.degree. C., a process for producing said amorphous polymer, a dibenzofuran copolymer comprising, in addition to a recurring unit represented by following formula (II), at least one type of recurring unit represented by following general formula (III) in a specific proportion and having a molecular weight giving a reduced viscosity of at least 0.2 dl/g as measured in the form of a 0.5% (W/V) solution in concentrated sulfuric acid at 25.degree. C., and a process for producing said copolymer. ##STR1## wherein A is --O--, --CO--, --S--, --SO.sub.2 --, a divalent alkylene group or a single bond and n is a number of 0, 1 or 2.

Abstract: The present invention relates to an aromatic polycarbonate composition which is stabilized by adding to an aromatic polycarbonate (containing substantially no chlorine atom) a very slight amount of at least one compound selected from a phosphorous acid diester and a phosphorous acid monoester and at least one compound selected from a phenolic antioxidant, a phosphorous acid triester and an organic phosphonite. This composition has the characteristics that molded products made therefrom are superior in hot-water resistance and steam resistance and recycling molding thereof causes substantially no coloration. Thus, this composition is high in industrial applicability.

Abstract: A porous, crystallized, aromatic polycarbonate prepolymer is disclosed, which comprises recurring aromatic carbonate units and terminal hydroxyl and aryl carbonate groups, wherein these terminal groups are in a specific molar ratio and has specific number average molecular weight, surface area and crystallinity. The prepolymer can readily be converted by solid-state condensation polymerization to a porous, crystallized, aromatic polycarbonate having excellent properties. The porous, crystallized, aromatic polycarbonate of the present invention can readily be molded to obtain a shaped, porous, crystallized polycarbonate. The porous, crystallized, aromatic polycarbonate and the shaped, porous, crystallized polycarbonate of the present invention have excellent heat resistance and solvent resistance and exhibit advantageously low water absorption so that these are suited for use as a filter material, an adsorbent or the like.

Abstract: A porous, crystallized, aromatic polycarbonate prepolymer is disclosed, which comprises recurring aromatic carbonate units and terminal hydroxyl and aryl carbonate groups, wherein these terminal groups are in a specific molar ratio, and has specific number average molecular weight, surface area and crystallinity. The prepolymer can readily be converted by solid-state condensation polymerization to a porous, crystallized, aromatic polycarbonate having excellent properties. The porous, crystallized, aromatic polycarbonate of the present invention can readily be molded to obtain a shaped, porous, crystallized polycarbonate. The porous, crystallized, aromatic polycarbonate and the shaped, porous, crystallized polycarbonate of the present invention have excellent heat resistance and solvent resistance and exhibit advantageously low water absorption so that these are suited for use as a filter material, an adsorbent or the like.

Abstract: There are disclosed a process for producing an aromatic (poly)etherketone or an aromatic (poly)ethersulfone having an ether group represented by the formula --Y--Ar--O--Ar--Y-- which process comprises reacting an aromatic halogen compound having at least one active halogen group represented by the formula --Y--Ar--X, where Y denotes a ketone group or a sulfone group; Ar denotes a phenylene group or a nuclear-substituted product thereof; and X denotes a halogen atom which is bonded at the ortho- or para-position relative to Y, with a specified salt of an alkali metal, and an aromatic polyetherketone polymer which has a repeating unit represented by formula (I) ##STR1## and which has a crystalline melting point not lower than 390.degree. C. and an intrinsic viscosity of 0.7 to 2.0 dl/g (sulfuric acid at 25.degree. C.).

Abstract: A copolymer which can be employed for various molded articles, particularly for uses which require a high nonflammability, which copolymer is a crystalline aromatic polyketone type copolymer which has an intrinsic viscosity of not less than 0.40 and has a linear polymer structure comprising structural units (A) represented by the formula (A) ##STR1## structural units (B) represented by the formula (B) ##STR2## and structural units (C) represented by the formula (C.sub.1) ##STR3## or by the formula (C.sub.2) ##STR4## the molar ratio of said units (B) to said units (C) being in the range from 30:70 to 99:1, and the unit (A) and either the unit (B) or the unit (C) being linked alternately; and a process producing the same.

Abstract: Crystalline aromatic polyketones having a linear polymer structure comprising repeating units [I] of ##STR1## and repeating units [II] of ##STR2## the repeating units [I] and [II] are bonded alternately, and the polymer has an intrinsic viscosity of at least 0.4, has excellent properties, particularly heat resistance, and can be used as shaped articles, coatings, films, fibers, etc.

Abstract: A process for preparing a crystalline aromatic polyetherketone having a reduced viscosity of 0.6 or more is disclosed. The process includes polycondensing an aromatic dihydroxy compound with a dihalogeno aromatic ketone in a solvent having the following general formula (I) or (II): ##STR1## wherein each of R.sub.1, R.sub.2 and R.sub.3 is independently a hydrogen atom, a C.sub.1-3 alkyl group or a phenyl group; X is an oxygen atom, a sulfur atom or a direct bond; Y is an oxygen atom or a ketone group; and n is 0 or 1;in the presence of an alkali compound.

Abstract: Polyethylene and an ethylene-.alpha.-olefin copolymer are produced by polymerizing ethylene or a mixture of ethylene with an .alpha.-olefin having 3 to 18 carbon atoms by use of a coordination polymerization catalyst containing a transition metal compound and an organometallic compound, deactivating said catalyst by adding a copolymer of at least one monomer selected from the group consisting of vinyl monomers having a carbonyl group represented by the formula: ##STR1## wherein R.sup.1 represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms; R.sup.2 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; M represents a metal element; and m represents the valence of M,or maleic anhydride with ethylene to be mixed with said catalyst, separating unaltered monomers from the polymer mixture.

Abstract: A modified linear medium- or low-density polyethylene composition obtained by uniformly melt kneading a mixture of a linear medium- or low-density polyethylene having a density of not less than 0.90 g/cm.sup.3 but less than 0.94 g/cm.sup.3 and a melt index (MI).sub.1 of not more than 3 g/10 minutes and a radical initiator in an amount of not less than 0.0005% by weight but less than 0.1% by weight based on the weight of the linear medium- or low-density polyethylene at a temperature of from the melting point of the linear medium- or low-density polyethylene to a temperature of less than the thermal decomposition temperature of the linear medium- or low-density polyethylene to such an extent that the ratio of the melt index of the modified linear medium- or low-density polyethylene composition (MI).sub.2 to that of the linear medium- or low-density polyethylene (MI).sub.1 [(MI).sub.2 /(MI).sub.1 ] is 0.05 to 0.9.

Abstract: A novel block copolymer mixture of conjugated diene (C.D.) and vinylaromatic hydrocarbon (V.H.) having a superior transparency and impact-resistance is produced by the following two step polymerizations using an organolithium compound as a catalyst and a solvent consisting mainly of an aliphatic hydrocarbon: a first step (A) of preparing a living (co)polymer of C.D. or C.D. and V.H., by polymerizing the monomer(s) in a ratio by weight of V. H. to C.D. of 0/100 to 60/40 and in an amount of 1 to 80% by weight of total monomers to be used, in the presence of said catalyst and solvent, and a second step (B) of preparing V.H. polymer or block copolymer of V.H. and C.D., by adding to said living (co)polymer, remaining monomer(s), in a ratio by weight of V.H. to C.D. of 100/0 to 65/35 and in an amount of 99 to 20% by weight of total monomers to be used, and said catalyst and solvent, and polymerizing the remaining monomer(s) to obtain a block copolymer mixture, this block copolymer mixture having a ratio of V.H.

Abstract: A novel block copolymer mixture of conjugated diene (C.D.) and vinylaromatic hydrocarbon (V.H.) having a superior transparency and impact-resistance is produced by the following two step polymerizations using an organolithium compound as a catalyst and a solvent consisting mainly of an aliphatic hydrocarbon:a first step (A) of preparing a living (co)polymer of C.D. or C.D. and V.H., by polymerizing the monomer(s) in a ratio by weight of V.H. to C.D. of 0/100 to 60/40 and in an amount of 1 to 80% by weight of total monomers to be used, in the presence of said catalyst and solvent, anda second step (B) of preparing V.H. polymer or block copolymer of V.H. and C.D., by adding to said living (co)polymer, remaining monomer(s), in a ratio by weight of V.H. to C.D. of 100/0 to 65/35 and in an amount of 99 to 20% by weight of total monomers to be used, and said catalyst and solvent, and polymerizing the remaining monomer(s) to obtain a block copolymer mixture,this block copolymer mixture having a ratio of V.H.

Abstract: A novel high-impact polystyrene composition superior to conventional high-impact polystyrene composition, in low temperature high-impact properties, tensile strength, processability, toughness, stiffness, etc. can be obtained by a radical polymerization of a mixture of (1) 2-20% by weight of a random copolymer having a composition of continuously and gradually reduced styrene content along the polymer chain of the copolymer which is obtained by the solution polymerization of butadiene and styrene in the presence of a lithium base catalyst and (2) 80-98% by weight of styrene, carried out in bulk polymerization manner or in a manner in which bulk and suspension polymerizations are used in series.