Abstract: A first crystalline polypropylene of the present invention satisfies the relationships of the following formulae (1) and (2): &agr;≦−0.42×ln(Mp)+7.3  (1),and Tm>1.85×ln(Mp)+144.5  (2), wherein &agr; is a 0° C. soluble content (% by weight) as measured through programmed-temperature fractionation, Mp is a peak molecular weight in a molecular weight distribution curve as measured through gel permeation chromatography, and Tm is a melting point (° C.) as measured through differential scanning calorimetry. A second crystalline polypropylene of the present invention satisfies the relationship given in the following formula (3): &agr;≦1.11[&eegr;]−0.42+1.40  (3) wherein &agr; is the same as above and [&eegr;] an intrinsic viscosity (dl/g) as measured in a tetralin solvent at 135° C.

Abstract: A first crystalline polypropylene of the present invention satisfies the relationships of the following formulae (1) and (2):

Abstract: Provided are propylene-ethylene block copolymers having the advantage of well-balanced physical properties of rigidity, impact resistance, etc. The propylene-ethylene block copolymers are characterized by (a), (b), (c1), (c2) and (c3): (a) The melt flow rate falls between 0.01 and 1000 g/10 min. (b) The room-temperature xylene-insoluble component has an [mmmm] fraction of not smaller than 98.9%. (cl) The amount of the room-temperature xylene-soluble component falls between 3 and 50% by weight. (c2) The T1 relaxation time component in pulse NMR is of a single relaxation component. (c3) The ethylene content, x % by weight, as measured through 13C-NMR, and the T1 relaxation time satisfy y≦0.0014x3−0.0897x2−1.0593x +231.6. The block copolymers may be characterized by (a), (b), (c1) and (c4): (a) The melt flow rate falls between 0.01 and 1000 g/10 min. (b) The room-temperature xylene-insoluble component has an [mmmm] fraction of not smaller than 98.9%.

Abstract: A composition useful in molding comprises (A) from 10-95% by weight of a syndiotactic styrene resin, (B) from 5-90% by weight of a thermoplastic resin such as a polyolefin, polyester, polyether, polyamide or polycarbonate, and ( ) from 1-15 parts by weight of a rubber polymer such as maleic anhydride-modified or unmodified styrene-(butadiene or isoprene) block copolymer.

Abstract: A polystyrene-based resin composition, comprising (A) a styrene-based resin with a mainly syndiotactic configuration, (B) a polyolefin, and (C) rubber polymer particles as main components, exhibits excellent heat resistance and impact resistance.

Abstract: A composition amenable to injection molding and extrusion comprises a syndiotactic styrene resin, a thermoplastic resin such as a polyolefin and an inorganic filler optionally contains a rubber.

Abstract: A composition comprises (A) a syndiotactic styrene-based resin and (C) rubber polymer particles such as graft copolymers, butadiene or isoprene block copolymers optionally hydrogenated and/or modified with maleic anhydride, and other rubbers, and, optionally, (B) a thermoplastic resin such as a polycarbonate, and/or (D) a filler such as glass fibers.

Abstract: Novel styrene-based resin compositions comprising a styrene-based resin having a mainly syndiotactic configuration in compbination with one or more of: (A) thermoplastic resins other than the styrene-based resin, (B) a rubber polyers, and (C) inorganic fillers. The compositions have improved heat resistance and impact resistance over non-syndiotactic styrene-based resin compositions.

Abstract: A polystyrene-based resin composition containing a styrene-based resin with mainly syndiotactic configuration, a polyamide, and a rubber polymer as main components.

Abstract: A composition comprising 20-80 weight percent of a styrene polymer with mainly syndiotactic configuration, and 20-80 weight percent of a polycarbonate, and optionally an inorganic filler.

Abstract: A polystyrene-based resin composition containing a styrene-based resin with mainly syndiotactic configuration and filler as main components. Styrene-based resins of mainly syndiotactic configuration include polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(alkoxystyrene), styrene copolymers comprised of polymerized units of at least of styrene, alkylstyrene, halogenated styrene and alkoxystyrene, and mixtures thereof.

Abstract: Disclosed are a polypropylene-based resin and a polypropylene-based resin composition having well-balanced, high-level flowability, stiffness and impact resistance. The polypropylene-based resin has an MI of from 30 to 70 g/10 min and a 25.degree. C. xylene-soluble content, x, of from 5 to 15% by weight, in which the 25.degree. C. xylene-soluble component is such that (a) its ethylene unit content, z, is from 20 to 30% by weight, and (b) its intrinsic viscosity, [72], indecalin at 135.degree. C. is not smaller than 2.00 dl/g, and in which the 25.degree. C. xylene-insoluble component is such that (c) its ethylene unit content, y (% by weight), satisfies the following:100y/[y.times.(1-x/100)+x].ltoreq.1.13z-16.6,(d) in GPC, the content of its constituent component having a molecular weight of not smaller than 10.sup.6 is not smaller than 2% by weight, (e) its MI is from 40 to 130 g/10 min, and (f) its stereospecificity index is not smaller than 98.5%.

Abstract: A polystyrene-based resin composition containing a styrene-based resin with mainly syndiotactic configuration and filler as main components. Styrene-based resins of mainly syndiotactic configuration include polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(alkoxystyrene), styrene copolymers comprised of polymerized units of at least of styrene, alkylstyrene, halogenated styrene and alkoxystyrene, and mixtures thereof.

Abstract: A styrene-based resin composition containing (A) a styrene-based resin with mainly syndiotactic configuration and (B) a thermoplastic resin other than the styrene-based resin exhibit excellent heat resistance and impact resistance. Optionally, the styrene-based resin composition may further contain (C) a rubber polymer and/or (D) an inorganic filler. More particularly, a composition containing 1-98% by weight (A) 1-98% by weight of a styrene-based resin with mainly syndiotactic configuration and 1-98% by weight (B) a polyethylene terephthalate resin or a polyester resin is disclosed.

Abstract: A resin composition comprising 5 to 95 parts by weight of a saponified product of an ethylene-vinyl acetate copolymer (A) having an ethylene content of 20 to 60 mol % and a degree of saponification of at least 90% and 95 to 5 parts by weight of a styrene-based polymer (B) having mainly syndiotactic configuration. The resin composition has gas barrier properties and a markedly improved heat resistance.

Abstract: Styrene-based resin composition containing as main components (A) 100 parts by weight of a styrene-based polymer having mainly a syndiotactic configuration and (B) 0.01 to 25 parts by weight of one or more nucleating agents selected from the group consisting of (1) metal salts of organic acids having an average particle diameter of not more than 50 .mu.m, (2) inorganic compounds having an average particle diameter of not more than 50 .mu.m, (3) organophosphorus compounds having an average particle diameter of not more than 50 .mu.m, and (4) metal salts of ionic hydrocarbon copolymer, and a process for producing styrene-based resin moldings by molding the above styrene-based resin composition at a temperature between room temperature and 200.degree. C. The resin composition of the present invention is suitable for injection molding and extrusion molding, and provides moldings which are of high crystallinity and are excellent in heat resistance, solvent resistance, chemical resistance and so forth.

Abstract: Disclosed is a resin composition which comprises (a) 5 to 95% by weight of a styrene-based polymer having a syndiotactic configuration, (b) 95 to 9% by weight of a thermoplastic resin having at least one polar group selected from a carboxyl group, a hydroxyl group and an amino group at the terminal; and (c) 0.01 to 15 parts by weight of a styrene-based copolymer obtained by copolymerizing a styrene compound with a vinyl compound having an epoxy group or a styrene-based copolymer obtained by copolymerizing a styrene compound with an .alpha.,.beta.-unsaturated carboxylic acid anhydride based on 100 parts by weight of the aobve components (a) and (b). The composition exhibits no laminar peeling and has an excellent appearance because affinity and dispersibility of the styrene-based polymer and the thermoplastic resin are improved, and a polystyrene-based resin composition improved in mechanical strength can also be obtained without using a complicated process.

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: There is disclosed a styrene-based polymer composition which comprises(A) 10 to 98% by weight of a styrene-based polymer having syndiotactic configuration with a racemic pentad of 30% or more and(B) 90 to 2% by weight of polyphenylene ether having an inrinsic viscosity of 0.28 dl/g or more at 30.degree. C. in chloroform.Also, a flame retarder, a flame-retardant aid, a rubber-like elastomer or an inorganic filler may optionally be added to the composition.Further, also disclosed is a stretched molding comprising stretching the above composition.

Abstract: A multi-layer material with a layer (A) of a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol % and a degree of saponification of at least 90% and a layer (B) of a styrene-based polymer having mainly syndiotactic configuration, or a resin composition comprising 5 to 95 parts by weight of a saponified product of an ethylene-vinyl acetate copolymer (A) having an ethylene content of 20 to 60 mol % and a degreee of saponification of at least 90% and 95 to 5 parts by weight of a styrene-based polymer (B) having mainly syndiotactic configuration has gas barrier properties and markedly improved heat resistance.In a molding comprising the resin composition or the multi-layer material, contents (food) can be stored for a long period of time at ambient temperature. Moreover, after retort sterilization, the container can be heated by boiling, or in a microwave oven or a grill oven (at 220 to 240.degree. C.