Abstract: A polymerization process for preparing triblock copolymers and multiblock copolymers. The process includes the polymerization of isobutylene below about -40.degree. C. in a reaction mixture which includes a titanium halide, a mixed solvent, and an initiator compound selected from the group consisting of cumyl ester and cumyl ether compounds. In at least some instances, the components are added in a particular order, sometimes together with a moisture scavenger. After formation of the polyisobutylene, a diene is added to the mixture containing the polyisobutylene and polymerized to form the desired copolymer. The diene portion of the copolymer may subsequently be cyclized to produce a copolymer exhibiting both thermoplastic and elastomeric properties. If desired the block copolymers can be subsequently modified to include functional side groups, or to provide photocuring capabilities.

Abstract: A novel low-crystalline propylene random copolymer composition comprising[I] 60 to 95% by weight of a propylene random copolymer and[II] 5 to 40% by weight of a low-crystalline propylene random copolymerwhich has excellent heat-sealability, heat-seal imparting property, transparency and antiblocking property and containing a reduced amount of a hydrocarbon-soluble component, a process for production thereof, and polypropylene composite laminated structure having improved heat-sealability and heat seal strength at low temperatures.

Abstract: A process for the production of a product comprising ethylene/propylene copolymer incorporated into a matrix of propylene homopolymer or copolymer comprising the following steps:(a) contacting propylene or propylene and at least one alpha-olefin having 2 to 8 carbon atoms, and hydrogen, wherein the alpha-olefin is present in a ratio of about 0.01 to about 0.06 mole of alpha-olefin per mole of propylene and the hydrogen is present in a ratio of about 0.001 to about 0.

Abstract: A process for the production of .alpha.-olefin block copolymer particles having excellent impact resistance at low temperature and excellent molding and processing characteristics, is disclosed. The process includes a two step gas phase polymerization procedure under specific conditions in the presence of a specific catalyst system.

Abstract: A process for producing a 4-methylpentene-1 copolymer comprising copolymerizing 4-methylpentene-1 with other .alpha.-olefin in a hydrocarbon solvent in the presence of a Ziegler-Natta catalyst and a resin composition containing the 4-methylpentene-1 copolymer are disclosed. The copolymerization comprises a first stage in which (A) a homopolymer or random copolymer of 4-methylpentene-1 having an .alpha.-olefin content of not more than 3 mol % and an intrinsic viscosity of at least 2.5 dl/g is prepared and a second stage in which (B) a random copolymer having an .alpha.-olefin content higher than that of the polymer (A) and no higher than 9 mol % and an intrinsic viscosity of at least 2.5 dl/g is prepared, and the produced copolymer insoluble in the solvent is separated to recover a 4-methylpentene-1 copolymer containing from 5 to 80% by weight of the polymer (A). The process produces a solvent-insoluble copolymer in an increased yield without impairing transparency of the copolymer.

Abstract: A process for producing a propylene block copolymer in the presence of a highly stereospecific olefin polymerization catalyst which comprises producing a crystalline polymer or copolymer of propylene in a first stage and random-copolymerizing propylene and another alpha-olefin in a mole ratio of from 10:90 to 90:10 in the presence of the propylene polymer or copolymer in a second stage; wherein in the random copolymerization, 0.0001 to 0.5 mole, per gram atom of aluminum in the catalyst, of an oxygen-containing compound being gaseous in a standard condition or 0.001 to 1 mole, per gram atom of aluminum in the catalyst, of an active hydrogen-containing compound being liquid or solid in a standard condition is fed into the random-copolymerization reaction system.

Abstract: A polypropylene molding composition with a good hardness and good impact strength at low temperatures is formed by two-stage polymerization of propylene and ethylene in liquid propylene in the presence of a special supported catalyst.

Abstract: A propylene-ethylene block copolymer from which molded products having high rigidity and superior high-impact properties can be prepared even without adding any particular additive, is provided, which copolymer is obtained by (i) polymerizing propylene in 70 to 95 weight % based on the total polymerized amount, using a catalyst obtained by reacting an organoaluminum compound (I) or a reaction product of (I) with an electron donor (A), with TiCl.sub.4, further reacting the resulting solid product (II) with (A) and an electron acceptor (B), and combining the resulting solid product (III) with an organoaluminum compound (IV) and an aromatic carboxylic acid ester (V), the molar ratio of (V) to (III) being 0.1 to 10.0, and then (ii) polymerizing ethylene or ethylene and propylene in 30 to 5 weight % based on the total polymerized amount, at one or more stages, using the same catalyst as above, the ethylene content being 3 to 20 weight % based on the total polymerized amount.

Abstract: A process for producing a chemically blended propylene polymer composition having an ethylene content ranging from 3 to 40% by weight and being greater than the weight of the rubbery propylene copolymer formed in stage (II) below, which comprises the following stages (I) and (II):(I) a first stage of polymerizing propylene containing 0 to 5 mole % of another olefin in the presence of a catalyst composed of (A) a solid titanium catalyst component consisting essentially of titanium, magnesium, halogen, and an electron donor, (B) an organoaluminum compound, and (C) an organic silicon compound having an Si--O--C bond or an Si--N--C bond to thereby form a crystalline propylene polymer or copolymer; and(II) a second stage of polymerizing propylene and ethylene, or propylene, ethylene and another olefin in the presence of the reaction product of the first stage and the same catalyst as used in the first stage to form a rubbery propylene copolymer and a crystalline ethylene polymer or copolymer.

Abstract: Propylene/ethylene block copolymers are prepared by a process in which, in an agitated fixed bed comprising small polymer particles and in each case in the presence of hydrogen, first (I) propylene is homopolymerized from the gas phase, in a first polymerization zone, by feeding in a Ziegler-Natta catalyst, and then (II) the product obtained in the first polymerization zone is fed into a second polymerization zone, where a mixture of propylene and ethylene is polymerized with the propylene homopolymer present in the product from the first polymerization zone.

Abstract: A novel quick setting polymer concrete composite comprising a furfuryl alcohol monomer, an aggregate containing a maximum of 8% by weight water, and about 1-10% trichlorotoluene initiator and about 20-80% powdered metal salt promoter, such as zinc chloride, based on the weight of said monomer, to initiate and promote polymerization of said monomer in the presence of said aggregate, within 1 hour after mixing at a temperature of -20.degree. C. to 40.degree. C., to produce a polymer concrete having a 1 hour compressive strength greater than 2000 psi.

Abstract: A process for the preparation of ethylene-propylene block copolymers at high catalyst productivity rates resulting in polymer products having improved impact strength-polymerized ethylene content relationship.