Abstract: A polypropylene resin composition including (A) 50-90 parts by weight of a polypropylene resin including (a) 3-30 weight % of stereoblock polypropylene having a weight-average molecular weight of 5,000-1,000,000, a percentage of five continuous propylene monomer units in which all propylene bonds are meso bonds and a percentage of five continuous propylene monomer units in which all propylene bonds are racemic bonds being 70% or more and 5% or more, respectively relative to the all propylene bonds, and (b) 70-97 weight % of an ultra-high stereospecific polypropylene having a melt flow rate of 0.1-1,000 g/10 minutes, an average meso chain length Nm calculated from a triad percentage determined from .sup.13 C-NMR spectrum by the following formula of Nm=2[mm]/[mr]+1, wherein [mm] is (isotactic triad/total triad).times.100 (%) and [mr] is (heterotactic triad/total triad).times.100 (%), meeting a relation of Nm>250+29.

Abstract: The thermoplastic resin composition of the present invention is made of:(a) 5-95 weight % of polypropylene;(b) 95-5 weight % of a polyester; and(c) 2-70 parts by weight, per 100 parts by weight of the total of (a) + (b), of a polyolefin-polyester graft copolymer.The polyolefin-polyester graft copolymer is constituted by 10-90 parts by weight of a polyester having an intrinsic viscosity [n] of 0.30-1.20 and an end carboxyl group content of 15-200 milliequivalent/kg; and (B) 90-10 parts by weight of a modified polyolefin having an epoxy group or carboxyl group content of 0.2-5 mol % and a weight-average molecular weight of 8,000-140,000. This thermoplastic resin composition may further contain (d) a modified polypropylene grafted with an unsaturated carboxylic acid or its anhydride.

Abstract: An ethylene polymer which Is capable of being degraded by microorganisms is provided which comprises a recurring unit represented by the general formula ##STR1## in which R is a divalent hydrocarbon group containing 2 to 20 carbon atoms, R' is a divalent hydrocarbon group containing 1 to 20 carbon atoms and A is a polyethylene segment comprising a recurring unit represented by the formula --CH.sub.2.CH.sub.2 -- and having a number average molecular weight (Mn) of 300 to 300,000, and the ethylene polymer having a number average molecular weight (Mn) of 500 to 5,000,000.

Abstract: The thermoplastic resin composition of the present invention is made of:(a) 5-95 weight % of polypropylene;(b) 95-5 weight % of a polyester; and(c) 2-70 parts by weight, per 100 parts by weight of the total of (a)+(b), of a polyolefin-polyester graft copolymer.The polyolefin-polyester graft copolymer is constituted by (A) 10-90 parts by weight of a polyester having an intrinsic viscosity [.eta.] of 0.30-1.20 and an end carboxyl group content of 15-200 milliequivalent/kg; and (B) 90-10 parts by weight of a modified polyolefin having an epoxy group or carboxyl group content of 0.2-5 mol % and a weight-average molecular weight of 8,000-140,000. This thermoplastic resin composition may further contain (d) a modified polypropylene grafted with an unsaturated carboxylic acid or its anhydride.

Abstract: A thermoplastic resin composition comprising (a) modified polyolefin produced by graft-polymerizing a polyolefin with a glycidyl compound represented by the following general formula: ##STR1## wherein R is a hydrogen atom or an alkyl group having 1-6 carbon atoms, Ar is an aromatic hydrocarbon group having 6-20 carbon atoms and containing at least one glycidyloxy group, and n is an integer of 1-4; and (b) a matrix polymer resin such as polyamide, polyester, polycarbonate etc.

Abstract: The present invention aims at providing an olefin polymerization catalyst comprising, as a component, a transition metal compound having two ligands such as .beta.-diketone, etc. coordinated, and having excellent properties as a polymerization catalyst in the polymerization of olefins including styrene compounds. This olefin polymerization catalyst comprises:(a) a transition metal compound represented by the general formula, ##STR1## wherein M represents titanium, zirconium, hafnium or vanadium, Y.sup.1 and Y.sup.2 each represent, same or different, halogen atoms or alkyl groups containing 1 to 10 carbon atoms and R.sup.1, R.sup.2 and R.sup.3 each represent hydrogen atoms or hydrocarbon groups containing 1 to 10 carbon atoms, at least one of which is a hydrogen atom but all of which must not be hydrogen atoms, and(b) an organoaluminum compound, in particular, aluminoxane.

Abstract: The modified polyolefin is produced by graft-polymerizing (a) 100 parts by weight of a polyolefin, with (b) 0.01-30 parts by weight of a glycidyl compound represented by the following general formula: ##STR1## wherein R is a hydrogen atom or an alkyl group having 1-6 carbon atoms, Ar is an aromatic hydrocarbon group having 6-20 carbon atoms and containing at least one glycidyloxy group, and n is an integer of 1-4. The glycidyl compound may be added stepwise to have a higher graft ratio. The modified polyolefin may be graft-copolymerized with polyesters at a high graft ratio.

Abstract: Rubber-reinforcing fiber cords are disclosed which are constituted by at least one kind of fibers selected from a group consisting of aromatic polyamide fibers, entire aromatic polyester fibers and polyvinylalcohol fibers having a tenacity of not less than 15 g/d. Spaces among filaments constituting the cord are each impreganted with a rubbery material. Radial tires are also disclosed which each comprise at least one pair of bead wires, at least one carcass ply cord layer and at least one belt ply cord layer. Carcass ply cords and/or belt ply cords are constituted by the above rubber-reinforcing fiber cords.

Abstract: Polyether urethane elastomer composition having improved mechanical properties has been prepared by using polyfunctional isocyanate, curing agent and polyether having active hydrogen terminal groups, wherein the weight average molecular weight of said polyether is within the range of 1,000 to less than 4,500 and the molecular weight distribution curve of said polyether has at least two peaks, at least one of which is located in the higher molecular weight region and at least another one of which is located in the lower molecular weight region than the rheological critical molecular weight of said polyether and wherein the equivalent ratio (d) of active hydrogen of a curing agent to the isocyanate group of said polyfunctional isocyanate is in the range of 0.9<d<1.2.