Abstract: A whitening-resistant, highly melt-viscoelastic ethylene-propylene copolymer and process for producing the same are provided, which copolymer is produced by copolymerizing ethylene with propylene in the presence of a specified stereoregular catalyst and at four stages under specified conditions, the catalyst being prepared by reacting an organoaluminum compound or its reaction product with an electron donor, with TiCl.sub.4, reacting the resulting solid product with an electron donor and an electron acceptor, and combining the resulting solid product with an organo-aluminum compound and an aromatic carboxylic acid ester so as to give a specified ratio, and at the four stages, the ethylene contents in monomers fed, the proportion of polymerization amounts and the intrinsic viscosities of polymers formed being specified.

Abstract: Oriented polymer material of high Young's modulus and low creep strain is provided by a process which comprises drawing polymer material having a weight average molecular weight greater than 150,000 and a ratio of weight average molecular weight to number average molecular weight greater than 5 at temperatures from 95.degree. C. to 140.degree. C. and at a rate such that the deformation ratio is greater than 18.

Abstract: Polypropylene compositions having high impact strength at low temperatures comprising as essential components:100 parts by weight of polypropylene having an isotacticity index >90,8-25 parts by weight of an amorphous copolymeric fraction (1) of ethylene-propylene soluble in xylene at 23.degree. C., containing 20-80% by weight of ethylene,2-10 parts by weight of an ethylene-propylene crystalline copolymeric fraction (2) having a crystallinity of the polyethylene type containing 50-90% by weight of ethylene;and in which the weight ratio between the total polymerized ethylene and fraction (1) is <1.The compositions are prepared by polymerization processes comprising at least a step of homopolymerization of propylene to stereoregular polymer and a subsequent step of polymerization of ethylene-propylene mixtures in the presence of catalysts comprising a titanium compound carried on a magnesium halide in active form.

Abstract: A process for the preparation of ethylene-propylene impact copolymers at improved catalyst productivity rates involving the formation of a propylene prepolymer by polymerization of propylene in liquid phase in the presence of a catalyst system containing titanium halide supported on magnesium halide and aluminum alkyl complexed with an electron donor. Ethylene and propylene are block polymerized onto the prepolymer in a vapor phase reaction zone in the presence of further added quantities of aluminum alkyl components.

Abstract: An ethylene-propylene block copolymer capable of producing foamed shaped articles having a structure of uniform and fine foams even without adding any other resins, and a process for producing the same are provided, which copolymer consists of a propylene homopolymer portion and an ethylene-propylene (EP) copolymer portion and is characterized in that .circle.1 the former portion is obtained by polymerizing propylene at two stages so that the portion can further consist of a lower molecular weight portion and a higher molecular portion; .circle.2 between the melt flow rates of the resulting block copolymer under a specified load and five times the load, there is a specified relationship; .circle.3 the EP copolymer portion has an ethylene content of 60 to 95% by weight based on this portion; and .circle.4 the block copolymer has an ethylene content of 10 to 40% by weight based on the copolymer.

Abstract: The invention relates to a thermoplastic propylene block copolymer comprising one or more substantially crystalline polypropylene blocks and one or more 1-alkene-propylene copolymer blocks, in at least one of which 1-alkene-propylene copolymer blocks diene units are present, and to a process for preparing such a propylene block copolymer.According to the invention, as diene, a cyclic hydrocarbon compound is used wherein at least one double bond forms part of a strained structure, particularly a polycyclic compound with 7 to 20 carbon atoms containing at least one 4- and/or 5-ring, with one or more double bonds in or to the ring.The invention offers the advantage that it is possible to prepare block copolymers which can otherwise not or hardly be made, while at the same time only a small quantity is formed of byproducts which are soluble in the dispersant.

Abstract: The present invention relates to a process for producing a polypropylene-ethylene block copolymer by a continuous multi-stage polymerization comprising a first stage in which polypropylene is polymerized in a first polymerization vessel in the presence of a propylene polymerization catalyst, and a second stage in which propylene and ethylene are copolymerized in a second polymerization vessel, wherein the polypropylene slurry discharged from the first polymerization vessel is supplied to a concentrator to separate said slurry into a concentrated polypropylene slurry and a supernatant liquid, the concentrated polypropylene slurry is then introduced through an upper part of a hydraulic sedimentation classifier to be contacted with a countercurrent of the upward flowing of the supernatant fluid introduced through a lower part of said classifier to obtain hydraulically sedimented polypropylene, and non-hydraulically sedimented polypropylene; the thus obtained hydraulically-sedimented polypropylene is then supplie

Abstract: Thermoplastic elastomeric sequentially prepared propylene and (ethylene-propylene) polymer, or propylene, (ethylene-propylene) and propylene polymer, made in solvent medium with catalyst system based on (a) complex of titanium tetrachloride and alkyl benzoate or a phenol, supported on magnesium dihalide and (b) trialkyl aluminum modified by electron rich substituted benzoate.

Abstract: A process for producing a thermoplastic elastomer in the presence of a Ziegler catalyst which comprises a first step of forming polypropylene and then a second step of forming an ethylene/propylene random copolymer, characterized in that(a) the catalyst is used such that the total amount of the polymer formed is at least 50 kg per gram of titanium metal in the catalyst,(b) a hydrocarbon having 3 or 4 carbon atoms is used as a slurry polymerization solvent,(c) the solvent phase of the slurry is evaporated and separated without bringing the resulting polymer into contact with alcohols and/or hydrocarbons having at least 5 carbon atoms,(d) the polymerization temperature in the second step is adjusted to not more than 50.degree. C.

Abstract: A process for producing ethylene-propylene block copolymer by the use of a catalyst employed for producing isotactic polypropylene is provided. This process is characterized in that a gas phase polymerization of propylene is substantially carried out in the presence of the catalyst obtained by combining a titanium trichloride composition with an average particle size of 10.about.100 .mu. and an organic aluminum to form the propylene polymer segment with a specific surface area more than 0.015 m.sup.2 /g at a yield of more than 3,000 g per 1 g of the titanium trichloride composition in the first step, and then a gas phase polymerization of a mixture of polypropylene and ethylene is successively carried out in the second step to form the copolymer segment with a copolymerization ratio of propylene:ethylene being 5.about.80 weight %:95.about.20 weight %, wherein the polymerized amount of the second step is 10-40% of total polymerized amount and wherein normal hexane extraction ratio (75.degree. C.

Abstract: A block copolymer comprising 60 to 95 parts by weight of a binary or tertiary random copolymer block A comprising propylene, ethylene and/or butene-1 and 5 to 40 parts by weight of a binary or tertiary random copolymer block B comprising butene-1, propylene and, optionally, ethylene. This block copolymer can be shaped into a film having excellent heat sealability, transparency and blocking resistance.

Abstract: Block copolymers are prepared by using two successive and different catalytic processes, a Ziegler-Natta type polymerization followed by a conventional anionic polymerization.

Abstract: A polypropylene molding composition of polypropylene, ethylene-propylene copolymer and polyethylene having a high hardness and increased impact strength and homogeneity after processing is obtained by way of a continuous three-stage polymerization, when the melt viscosities of the polymer mixtures obtained in the individual stages are in a determined ratio of one to the other.

Abstract: A crosslinked product is derived from an olefinic block copolymer comprising 5 to 70 parts by weight of at least one block (A), which is selected from homopolymer blocks of propylene and random copolymer blocks of propylene and ethylene or a C.sub.4-12 .alpha.-olefin and has a propylene content of 60 to 100% by weight, and 30 to 95 parts by weight of at least one block (B), which is a random copolymer of ethylene and at least one C.sub.3-12 .alpha.-olefin and has an ethylene content of 10 to 85% by weight. This crosslinked product is characterized in that:(1) the content therein of hot xylene insoluble components is from 5 to 75% by weight; and(2) the fluidity thereof, i.e., the quantity thereof flowing per second (cc/sec..times.10.sup.-3) out through the orifice of Koka flow tester, is 3 to 500 cc/sec..times.10.sup.

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 propylene block copolymer produced by polymerizing propylene, ethylene and an .alpha.-olefin having 4 to 8 carbon atoms in two stages with a Zieglar-Natta catalyst by a process which comprises (A) supplying propylene and ethylene in the first stage and propylene and the .alpha.-olefin in the second stage, or (B) supplying propylene and the .alpha.-olefin in the first stage and propylene and ethylene in the second stage, to the polymerization system, wherein the amounts of propylene and ethylene supplied in the first stage of (A) or in the second stage of (B) are 90 to 99 wt % and 10 to 1 wt % based on the total amount of propylene and ethylene supplied in the first stage of (A) or in the second stage of (B), respectively, the amounts of propylene and the .alpha.-olefin supplied in the second stage of (A) or in the first stage of (B) are 60 to 98 wt % and 40 to 2 wt % based on the total amount of propylene and the .alpha.

Abstract: Thermoplastic elastomeric block copolymers having the general formula (AB).sub.n A, wherein each A is a crystalline polypropylene block, each B is a random ethylene-propylene copolymer block and n is an integer from 1 to about 12 exhibit structural and physical properties differences in comparison to related products.

Abstract: A propylene-ethylene block copolymer in the presence of a catalyst comprises as main components, a solid titanium-containing catalytic component and an organoaluminum compound having the formulaAIR.sub.m.sup.1 Cl.sub.3-m(R.sup.1 represents a C.sub.1-20 hydrocarbon moiety; and m is 3.gtoreq.m>1.5) by producing a homopolymer of propylene or a propylene-ethylene copolymer by polymerizing propylene or both propylene and ethylene at a vapor phase propylene concentration of 90 mol % or higher based on the sum of propylene and ethylene in a first step and producing a propylene-ethylene block copolymer by copolymerizing propylene and ethylene at a vapor phase propylene concentration of less than 90 mol % based on the sum of propylene and ethylene in the presence of the polymer resulted in the first step and the catalyst in a second step is produced by newly adding an aluminum compound having the formulaAlR.sub.n.sup.2 X.sub.3-n(R.sup.2 represents a C.sub.

Abstract: 1.

Abstract: A propylene-ethylene block copolymer is produced in the presence of a catalytic system essentially comprising an organoaluminum compound and a solid titanium trichloride catalytic complex having an atomic ratio of Al to Ti of less than 0.15 and having a complexing agent in two stages of polymerization;(a) a first stage for polymerizing propylene in the presence of a liquid propylene and hydrogen to produce a propylene homopolymer having a melt flow index of 1 to 150 at a ratio of 70 to 95% by weight based on a total of polymers; and(b) a second stage for copolymerizing propylene and ethylene in the presence of hydrogen and a liquid propylene at a concentration of propylene in vapor phase based on a total of propylene and ethylene in vapor phase of 50 to 85 mol. % and at a concentration of hydrogen in vapor phase based on a total of propylene and ethylene in vapor phase of 0.5 to 30 mol %, to produce ethylene-propylene copolymer having a melt flow index of 10.sup.-7 to 0.

Abstract: A process for producing a propylene-ethylene block copolymer by subjecting propylene and ethylene to three-step polymerization using a stereoregular polymerization catalyst, which comprises in the first step polymerizing propylene alone or a propylene/ethylene mixture so that the average ethylene/propylene reaction ratio is 6/94 or less, thereby polymerizing 60 to 95% by weight of the total polymerization amount, in the second step polymerizing a propylene/ethylene mixture so that the average ethylene/propylene reaction ratio is 25/75 to 67/33, thereby polymerizing 1 to 20% by weight of the total polymerization amount, and in the third step polymerizing a propylene/ethylene mixture so that the average ethylene/propylene reaction ratio is 76/24 to 89/11, thereby polymerizing 4 to 35% by weight of the total polymerization amount, wherein in the second and third steps, ethylene alone is supplied thereby gradually decreasing the amount of propylene in the polymerization system from the first step to the succeedin

Abstract: A propylene block copolymer comprising propylene, ethylene and a straight-chain .alpha.-olefin of 5 to 12 carbon atoms is characterized in that: its limiting viscosity is 0.3 to 15 dl/g (at 135.degree. C., in decalin); it comprises specified quantities of these monomers; and when it is subjected to successive extraction with o-dichlorobenzene at 40.degree. C. and 80.degree. C., the quantities, fusion peak temperatures, and content of the .alpha.-olefin of the resulting fractions are respectively within specific limits of values.

Abstract: A process for the preparation of ethylene-propylene block copolymers at improved catalyst productivity rates involving the formation of a propylene prepolymer by polymerization of propylene in liquid phase in the presence of a catalyst system containing titanium halide supported on magnesium halide and aluminum alkyl complexed with an electron donor. Ethylene and propylene are block polymerized onto the prepolymer in a vapor phase reaction zone in the presence of further added quantities of similar catalyst components. The product of the process has higher ethylene and block contents as compared to products formed with none or only one of the components being added to the vapor phase reaction zone.

Abstract: A block copolymer consisting essentially of crystalline polymerized propylene segments joined to crystalline segments of polymerized .alpha.-mono-olefinic hydrocarbon other than propylene. These block copolymers have an inherent viscosity in Tetralin at 145.degree. C. of from about 0.4 to 2.4, a density of at least 0.85, a brittle point below 0.degree. C. and contain at least 80 percent, by weight, of polymerized propylene.

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.

Abstract: Substantially crystalline block polymers comprising a homo-polymer block of an alpha-olefin having 2-8 carbon atoms and attached thereto a copolymer block of at least 2 alpha-olefins containing 2-2 carbon atoms, one of which may be the same or different from the alpha-olefin from which the homo-polymer block is prepared. Such block polymers are prepared in the presence of a stereospecific catalyst system by contacting the aforesaid alpha-olefin with said catalyst system to form the solid, substantially crystalline homo-polymer block, and then contacting the same catalyst system with the aforesaid mixture of said alpha-olefins. In an embodiment between about 55 and 95% of the polymerization time is expended in preparing the homo-polymer block. When preparing the copolymer block, one uses at least as much of the least reactive alpha-olefin, or more of the same, as one uses of the more reactive monomers.

Abstract: Compatibilized polymer blends are described comprising a blend of olefin polymer, nitrile rubber, and a compatibilizing amount of block copolymer comprising nitrile rubber compatibilizing segments and olefin polymer compatibilizing segments.

Abstract: A process for producing an ethylene copolymer having a density of from 0.900 to 0.945 g/cm.sup.3 by copolymerizing in two steps a predominant amount of ethylene with a minor amount of an alpha-olefin containing at least 3 carbon atoms at room temperature to not more than about 100.degree. C. under a pressure of about 1 to about 100 kg/cm.sup.2 in the presence of a catalyst composed of (A) a titanium catalyst component supported on a magnesium compound and (B) an organoaluminum compound; characterized in that said copolymerization is carried out in(i) a first step where about 0.01 to about 50 g, per gram of the titanium catalyst component (A), of the alpha-olefin containing at least 3 carbon atoms is polymerized, said catalyst further comprising an organic acid ester (C), and then(ii) a second step where the final product of ethylene copolymer is formed in an amount more than about 100 times the weight of the polymer formed in the first step.

Abstract: A method for continuous production of block copolymers having a block of propylene homopolymer and blocks of polymer of ethylene. The block copolymers produced thereby. In a first stage a first reaction mixture containing a polymer of ethylene is produced with continuous transfer of a portion of this reaction mixture along with propylene monomer and a catalyst modifier into a second stage in which a block copolymer having a block of propylene homopolymer and blocks of polymer of ethylene is produced. In preferred embodiments the polymer of ethylene is ethylene homopolymer and/or ethylene-propylene random copolymer.

Abstract: A modified polypropylene having improved impact resistance is obtained by producing, in the presence of a stereoregular polymerization catalyst and in three steps, two types of polypropylene blocks formed stepwise at different temperatures and then poly(ethylene or ethylene/propylene) block, the polymerization temperatures employed and the quantities of polymers produced in each step being in specific ranges.

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.

Abstract: A process for producing propylene-ethylene block copolymers by a three-step polymerization technique using a stereoregular catalyst, characterized in that the first-step polymerization is carried out by supplying propylene alone or a propylene/ethylene mixture so that the ethylene/propylene reaction ratio is 6/94 or less, thereby polymerizing 60 to 95% by weight of the total polymerization amount, the second-step polymerization is carried out by supplying a propylene/ethylene mixture so that the ethylene/propylene reaction ratio is 15/85 to 79/21, thereby polymerizing 1 to 20% by weight of the total polymerization amount, and the third-step polymerization is carried out by supplying a propylene/ethylene mixture so that the ethylene/propylene reaction ratio is 50/50 to 89/11, thereby polymerizing 4 to 35% by weight of the total polymerization amount, with the ethylene/propylene reaction ratio in the third step made larger than that in the second step.

Abstract: A process for producing a modified polypropylene by copolymerizing propylene with ethylene in the presence of a Ziegler-Natta catalyst is provided.This process consists of the following three steps:a first step of carrying out polymerization so as to give a propylene polymer corresponding to 75-90% by weight based on a final modified polypropylene and having an ethylene content of 2% by weight or lower,a second step of preparing an ethylene-propylene random copolymer (A) having an intrinsic viscosity of 12 dl/g or higher and an ethylene content of 50-95% by weight; anda third step of preparing an ethylene-propylene random copolymer (B) having an intrinsic viscosity of 9.5 dl/g or lower and an ethylene content of 40-90% by weight,the proportion of said (A) in the total amount of said (A) and (B) being adjusted to 4-30% by weight. In this process, it is possible to prepare said (B) in the second step and then prepare said (A) in the third step.

Abstract: Waterflood oil recovery process involving the use of an amphoteric polyelectrolyte as a thickening agent for mobility control. The amphoteric polyelectrolyte is a copolymer of a quaternary vinyl pyridinium sulfonate and a water-insoluble alpha olefin or hydrogenated diene. Specifically disclosed are vinyl pyridinium sulfonate-styrene block copolymers. The amphoteric polyelectrolytes are stable in high temperature and high brine environments.

Abstract: Particles of titanium trichlorides usable for the stereospecific polymerization of alpha-olefines, especially propylene, having been dried until their liquid content is less than 1% by weight relative to the weight of titanium trichloride present in said particles, as well as a process for the preparation of such particles and a process for stereospecific polymerization in the presence thereof.

Abstract: A process is disclosed for fabricating a thermoplastic, which thermoplastic is either a thermoplastic ionomer or a multiphase graft or block copolymer of the ABA (AB).sub.n, or ##STR1## wherein n is greater than 1 and wherein the polymer blocks, A and B, are each thermoplastic resins having softening points substantially above room temperature with the B block being present in at least about 30 wt. % of the total polymer. The thermoplastic composition is first suspended in finely divided form in a liquid medium in a sufficient amount such that the solids content of the resulting suspension is in the range of from about 15 to about 75 wt. %. The liquid medium must be nonvolatile and must be capable of plasticizing the B block (or the backbone if the ionomer is employed) of the thermoplastic composition above the softening point of that block but must not be capable of plasticizing the A block to a substantial extent. The suspension is then applied as a coating to any desired surface, e.g.

Abstract: Linear telechelic diene polymers with molecular weights of about 300 to about 20,000 which contain hydrazide end groups and to a process for their preparation as well as to their use for synthesizing high molecular weight polymers.