Abstract: The present invention provides such a three-dimensional ladder polymer that has, as a main chain, a silsesquioxane skeleton having a structure of the cage structure of octasilsesquioxane with two broken corners. The polymer of the invention is a polymer obtained by using a silsesquioxane derivative represented by formula (1-0). R0 each represents hydrogen, alkyl, cycloalkyl, aryl or arylalkyl, R1 each represents chlorine, a group defined as similar to R0, or a group having —CN, X independently represents hydrogen, chlorine, a group defined as similar to R1, or a group having one of —CH?CH—, —C?C—, —OH, —COOH, —COO—, 2-oxapropane-1,3-dioyl, oxiranyl, oxiranylene, oxetanyl, oxetanylene, 3,4-epoxycyclohexyl, —SH, —NCO, —NH— and —NH2; and at least two of X each is a reactive group.

Abstract: The present invention provides such a three-dimensional ladder polymer that has, as a main chain, a silsesquioxane skeleton having a structure of the cage structure of octasilsesquioxane with two broken corners. The polymer of the invention is a polymer obtained by using a silsesquioxane derivative represented by formula (1-0). R0 each represents hydrogen, alkyl, cycloalkyl, aryl or arylalkyl, R1 each represents chlorine, a group defined as similar to R0, or a group having —CN, X independently represents hydrogen, chlorine, a group defined as similar to R1, or a group having one of —CH?CH—, —C?C—, —OH, —COOH, —COO—, 2-oxapropane-1,3-dioyl, oxiranyl, oxiranylene, oxetanyl, oxetanylene, 3,4-epoxycyclohexyl, —SH, —NCO, —NH— and —NH2; and at least two of X each is a reactive group.

Abstract: A polypropylene resin composition is diclosed which comprises (a) 50-80% by weight of a specific polypropylene/ethylene-propylene copolymer composition, (b) 5-40% by weight of a specific ethylene/.alpha.-olefin copolymer rubber, (c) 1-10% by weight of a specific hydrogenated diene block copolymer, and (d) 10-30% by weight of talc, wherein the polypropylene component of the component (a) has a melt flow rate of 100-1,000 g/10 min and a C.sub.f value (cross fractionation ratio) of not more than 0.5. The resin composition has excellent flowability and can impart excellent rigidity, high-temperature rigidity and impact resistance, and well-balanced combination thereof to the molded articles.

Abstract: A propylene-ethylene copolymer composition is obtained which has good moldability and an excellent balance of rigidity, toughness, and impact-strength. The composition has a melt flow rate of 10 to 300 g/10 minutes and is obtained by producing 60 to 95% by weight, based on the weight of whole polymer, of a propylene polymer having a melt flow rate (ASTM D1238) in the range of 100 to 1,000 g/10 minutes and having a ratio (Cf) of integrated values of the propylene polymer dissolved in o-dichlorobenzene at a temperature of lower than 112.degree. C., and a temperature of 112.degree. C. or higher, respectively, of 0.5 or less, by carrying out polymerization of propylene in the presence of a highly stereoregular catalyst and hydrogen in a polymerization step (I), and then producing 5 to 40% by weight, based on the weight of whole polymer, of an ethylene-propylene copolymer by feeding ethylene and propylene to the propylene polymer to react so that the content of ethylene becomes 30 to 80% by weight.

Abstract: A catalyst component for olefin polymerization composed of a solid component (IV) and capable of affording a supported type catalyst composed of large particles and having a sharp particle size distribution is provided,which solid component (IV) is obtained bystep A of reacting an organic Mg compound of a specified formula with a 1-20C saturated or unsaturated mono- or polyhydric alcohol C in the presence of CO.sub.

Abstract: A catalyst for use in polymerization of olefins which comprises a carrier mainly composed of a magnesium compound precipitated from a solution and a catalytic component supported on the carrier and selected from titanium halides, vanadyl halides and vanadium halides is described. The catalyst is obtained by a process which comprises: (A) mixing (a) at least one magnesium compound with (c) a saturated or unsaturated monohydric or polyhydric alcohol for reaction in dissolved state in the presence of (b) carbon dioxide in an inert hydrocarbon solvent to obtain component (A); (B) subjecting the component (A) to mixing and reaction with (d) a titanium and/or a vanadyl halide and/or a vanadium halide of the general formula, VX.sub.r (OR.sup.8).sub.4-r, and also with (e) at least one boron compound, Si compound and/or Siloxane compound thereby obtaining solid product (I); (C) reacting the solid product (I) with (f) a cyclic ether with or without R.sup.