Abstract: A nitride semiconductor epitaxial substrate includes: a Si substrate; a nitride semiconductor epitaxial layer disposed above the Si substrate; and a mixed crystal layer disposed between the Si substrate and the nitride semiconductor epitaxial layer, and containing Si and a group III metal element, the mixed crystal layer containing a high concentration of C. The mixed crystal layer has a concentration of at least 1.0×10+21 cm?3, and a transition metal element concentration of at most 5.0×10+16 cm?3.

Abstract: The present invention provides a method for producing a trialkyl gallium comprising the steps of reacting gallium, magnesium, and an alkyl halide in an ether, and diluting during the reaction the reaction system with an ether; a method for producing a trialkyl gallium comprising the steps of heating in a vacuum a mixture of magnesium and molten gallium, and reacting the mixture with an alkyl halide in a solvent; and a method for producing a trialkyl gallium comprising the step of reacting an alkyl metal with an alkylgallium halide compound represented by the formula Ga2RmX6?m wherein R is a methyl or ethyl group, X is a halogen atom, and m is an integer from 1 to 5.

Abstract: The present invention provides method 1 for producing a trialkyl gallium comprising the steps of reacting gallium, magnesium, and an alkyl halide in an ether, and diluting during the reaction the reaction system with an ether; method 2 for producing a trialkyl gallium comprising the steps of heating in a vacuum a mixture of magnesium and molten gallium, and reacting the mixture with an alkyl halide in a solvent; and method 3 for producing a trialkyl gallium comprising the step of reacting an alkyl metal with an alkylgallium halide compound represented by the formula Ga2RmX6-m wherein R is a methyl or ethyl group, X is a halogen atom, and m is an integer from 1 to 5.

Abstract: The present invention provides a method for producing a trialkyl gallium comprising the steps of reacting gallium, magnesium, and an alkyl halide in an ether, and diluting during the reaction the reaction system with an ether; a method for producing a trialkyl gallium comprising the steps of heating in a vacuum a mixture of magnesium and molten gallium, and reacting the mixture with an alkyl halide in a solvent; and a method for producing a trialkyl gallium comprising the step of reacting an alkyl metal with an alkylgallium halide compound represented by the formula Ga2RmX6?m wherein R is a methyl or ethyl group, X is a halogen atom, and m is an integer from 1 to 5.

Abstract: The present invention provides method 1 for producing a trialkyl gallium comprising the steps of reacting gallium, magnesium, and an alkyl halide in an ether, and diluting during the reaction the reaction system with an ether; method 2 for producing a trialkyl gallium comprising the steps of heating in a vacuum a mixture of magnesium and molten gallium, and reacting the mixture with an alkyl halide in a solvent; and method 3 for producing a trialkyl gallium comprising the step of reacting an alkyl metal with an alkylgallium halide compound represented by the formula Ga2RmX6-m wherein R is a methyl or ethyl group, X is a halogen atom, and m is an integer from 1 to 5.

Abstract: There are provided a propylene-based polymer characterized in that (1) the xylene-extraction insoluble portion (XI) is 99.0 wt % or greater, (2) the isotactic pentad ratio (IP) is 98.0% or greater as measured by 13C nuclear magnetic resonance spectroscopy, (3) the isotactic average chain length (N) is 500 or greater, and (4) the total amount of each of the fractions obtained by column separation of the xylene insolubles whose average chain length (Nf) is 800 or greater accounts for 10 wt % or more of the entirety, and a method for its production, as well as a propylene-based polymer composition prepared by combining with this propylene-based polymer at least a nucleating agent in the range of 0.05-15 wt %. In addition, there are provided a polymerization catalyst component allowing the production of such a propylene-based polymer, and a method for its production.

Abstract: There are provided a propylene-based polymer characterized in that (1) the xylene-extraction insoluble portion (XI) is 99.0 wt % or greater, (2) the isotactic pentad ratio (IP) is 98.0% or greater as measured by 13C nuclear magnetic resonance spectroscopy, (3) the isotactic average chain length (N) is 500 or greater, and (4) the total amount of each of the fractions obtained by column separation of the xylene insolubles whose average chain length (Nf) is 800 or greater accounts for 10 wt % or more of the entirety, and a method for its production, as well as a propylene-based polymer composition prepared by combining with this propylene-based polymer at least a nucleating agent in the range of 0.05-15 wt %. In addition, there are provided a polymerization catalyst component allowing the production of such a propylene-based polymer, and a method for its production.

Abstract: There are provided a propylene-based polymer characterized in that (1) the xylene-extraction insoluble portion (XI) is 99.0 wt % or greater, (2) the isotactic pentad ratio (IP) is 98.0% or greater as measured by .sup.13 C nuclear magnetic resonance spectroscopy, (3) the isotactic average chain length (N) is 500 or greater, and (4) the total amount of each of the fractions obtained by column separation of the xylene insolubles whose average chain length (N.sub.f) is 800 or greater accounts for 10 wt % or more of the entirety, and a method for its production, as well as a propylene-based polymer composition prepared by combining with this propylene-based polymer at least a nucleating agent in the range of 0.05-15 wt %. In addition, there are provided a polymerization catalyst component allowing the production of such a propylene-based polymer, and a method for its production.

Abstract: A process for producing a catalyst carrier for an olefin polymerization comprising:(i) passing a mixture to be emulsified comprised of (A) a halogenated magnesium adduct and (B) a dispersion medium through an emulsifying apparatus comprised of (1) a conduit for passage of the mixture to be emulsified, (2) a vibrator element disposed in the conduit and vibrating in the axial direction of the conduit, and (3) a vibration device for giving the vibration movement to the vibrator element; and(ii) quenching the resultant mixture.

Abstract: A propylene block copolymer comprising a matrix phase and a dispersed phase dispersed in said matrix phase, said matrix phase comprising (a) polypropylene; said dispersed phase having an average particle diameter of from 0.1 to 5 .mu.m; and said dispersed phase comprising an outer layer comprising (b) propylene-.alpha.-olefin copolymer rubber and an inner layer comprising (c) crystalline polyethylene dispersed therein a plurality of particles comprising an outer layer comprising (b') propylene-.alpha.-olefin copolymer rubber and an inner layer comprising (a') polypropylene, a propylene block copolymer comprising a matrix phase and a dispersed phase dispersed in said matrix phase, said matrix phase comprising (a) polypropylene; said dispersed phase having an average particle diameter of from 0.1 to 5 .mu.m; and said dispersed phase comprising (b) propylene-.alpha.

Abstract: A propylene block copolymer, a process for preparation of the propylene block copolymer, and a propylene resin composition comprising the propylene block copolymer. The propylene block copolymer comprises (a) from 35 to 95% by weight of a polypropylene block and (b) from 10 to 65% by weight of a block of a copolymer of a propylene and other .alpha.-olefins, the propylene block copolymer having: (i) in a crystallization temperature curve determined by a differential scanning calorimeter, besides a main peak, secondary peaks in a temperature range of from 90.degree. to 100.degree. C., and a proportion of the area of the secondary peaks to that of a main peak of from 1.5 to 10%; and (ii) a relationship between an amount of a soluble content on xylene extraction at 25.degree. C. and a proportion of the area of the secondary peaks to that of the main peak represented by equation (I):0.1X.sub.IS -1.ltoreq.SMA (I)wherein X.sub.IS represents an amount of a soluble content on xylene extraction at 25.degree. C.

Abstract: A propylene block copolymer comprising a matrix phase and a dispersed phase dispersed in said matrix phase, said matrix phase comprising (a) polypropylene; said dispersed phase having an average particle diameter of from 0.1 to 5 .mu.m; and said dispersed phase comprising an outer layer comprising (b) propylene-.alpha.-olefin copolymer rubber and an inner layer comprising (c) crystalline polyethylene dispersed therein a plurality of particles comprising an outer layer comprising (b') propylene-.alpha.-olefin copolymer rubber and an inner layer comprising (a') polypropylene, a propylene block copolymer comprising a matrix phase and a dispersed phase dispersed in said matrix phase, said matrix phase comprising (a) polypropylene; said dispersed phase having an average particle diameter of from 0.1 to 5 .mu.m; and said dispersed phase comprising (b) propylene-.alpha.

Abstract: A propylene block copolymer comprising: (a) a propylene homopolymer part having (i) an insoluble amount on xylene extraction at 25.degree. C. of 99.0% by weight or more; (ii) an isotactic pentad fraction of 98.0% or more; (iii) an isotactic average chain length of 500 or more; and (iv) a total amount of fractions having an isotactic average chain length of 800 or more obtained in a column chromatographic separation of 10% by weight or more, and (b) a copolymer part comprising propylene and at least one of ethylene and an .alpha.-olefin having from 4 to 12 carbon atoms, the proportion of the propylene homopolymer part (a) being from 50 to 97% by weight based on the total amount of the propylene homopolymer part (a) and the copolymer part (b), and the proportion of the copolymer part (b) being from 3 to 50% by weight based on the total amount of the propylene homopolymer part (a) and the copolymer part (b).

Abstract: Disclosed is a catalyst composition for use in the polymerization of olefins, which is comprised of (a) a catalyst component containing magnesium, titanium, a halogen, and an ingredient derived from a keto-ester compound, and (b) an organic aluminum compound. The catalyst activity and capability of providing a highly stereoregular polymer are enhanced by preparing the catalyst component (a) by a process wherein, during or after the formation of a solid catalyst component containing magnesium, titanium, and a halogen, the solid catalyst component is treated with a keto-ester of the formula: ##STR1## wherein R.sup.1, R.sup.2 and Z represent a hydrocarbon group.

Abstract: Disclosed is a catalyst composition for use in the polymerization of olefins, which is comprised of (a) a catalyst component containing magnesium, titanium, a halogen, and an ingredient derived from a keto-ester compound, and (b) an organic aluminum compound. The catalyst activity and capability of providing a highly stereoregular polymer are enhanced by preparing the catalyst component (a) by a process wherein, during or after the formation of a solid catalyst component containing magnesium, titanium, and a halogen, the solid catalyst component is treated with a keto-ester of the formula: ##STR1## wherein R.sup.1, R.sup.2 and Z represent a hydrocarbon group.