摘要:
A process for the production of EPDM comprising reacting ethylene, propylene, ethylidene norbornene, and hydrogen, in the gas phase, in a fluidized bed, under polymerization conditions, in the presence of a catalyst system comprising:(a) a titanium based catalyst having the formula Mg.sub.a Ti(OR).sub.b X.sub.c (ED).sub.d whereinR is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms;each OR group is alike or different;each X is independently chlorine, bromine, or iodineED is an electron donora is 0.5 to 56;b is 0, 1, or 2;c is 2 to 116; andd is greater than 1.5 a+2;(b) at least one modifier having the formula BX.sub.3 or AlR.sub.(3-b) X.sub.b wherein each R is alkyl or aryl and is alike or different, and X and b are as defined above for component (a),wherein components (a) and (b) are impregnated into an inorganic support; and(c) a hydrocarbyl aluminum cocatalyst with the following proviso:(i) the partial pressure of ethylene is in the range of about 10 to about 150 psi;(ii) the molar ratio of propylene to ethylene is in the range of about 1.5:1 to about 5:1;(iii) the molar ratio of hydrogen to ethylene is in the range of about 0.001:1 to about 0.1:1; and(iv) the amount of ethylidene norbornene is about 1.5 to about 15 percent by weight based on the weight of the fluidized bed.
摘要:
A process of modifying ethylene polymers by reacting granular ethylene polymers having a density of about 0.87 to about 0.93 gram per cc and a pore volume of about 0.1 to about 1 cc per gram with a gaseous chlorosulfonating agent to produce elastomeric, granular, chlorosulfonated polymers having a tensile modulus of less than about 2,000 psi and a crystallinity of less than about 10 percent.
摘要:
A gas phase process for the production of an in situ polyethylene blend comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a magnesium/titanium based catalyst system including an activator and a cocatalyst in each of two fluidized bed reactors corrected in series, under polymerization conditions, with the provisos that: (a) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series; (b) other than the active catalyst referred to in proviso (a) and the cocatalyst referred to in proviso (f), no additional catalyst is introduced into the second reactor; (c) in the first reactor in which a relatively high molecular weight copolymer is made: (1) the alpha-olefin is present in a ratio of about 0.01 to about 0.4 mole of alpha-olefin per mole of ethylene; and (2) optionally, hydrogen is present in a ratio of about 0.001 to about 0.3 moles of hydrogen per mole of ethylene; (d) in the second reactor in which a relatively low molecular weight copolymer is made: (1) the alpha-olefin is present in a ratio of about 0.01 to about 0.6 mole of alpha-olefin per mole of ethylene; and (2) hydrogen is present in a ratio of about 1 to about 2.5 moles of hydrogen per mole of ethylene; (e) a sufficient amount of one or more hydrocarbons is added to the first reactor or to the mixture formed in the first reactor prior to its introduction into the second reactor to provide about 0.5 to about 15 parts by weight of hydrocarbon(s) per 100 parts by weight of the in situ blend, each of said hydrocarbons being a saturated alicyclic hydrocarbon, which is liquid at process temperature, is non-polar, is essentially amorphous, and contains less than about 15 percent by weight paraffin wax; and (f) additional hydrocarbyl aluminum cocatalyst is introduced into the second reactor in an amount sufficient to restore the level of activity of the catalyst transferred from the first reactor to about the initial level of activity in the first reactor.
摘要:
A pre-formed composition having essentially no yield point comprising a blend of:(a) at least about 50 percent by weight of a copolymer of ethylene and a 4 to 8 carbon atom alpha-olefin having a density in the range of 0.880 to 0.915 gram per cubic centimeter; a melt index of no greater than about one gram per 10 minutes; long chain branching in an amount of about 0.5 to about 1.5 long chains per 1000 carbon atoms; and a molecular weight of at least about 200,000; and(b) at least about 5 percent by weight of a copolymer of ethylene and vinyl acetate or a copolymer of ethylene and ethyl acrylate, the percent by weight being based on the combined weight of components (a) and (b).
摘要:
A process for substantially eliminating surface melt fracture during extrusion of a thermoplastic polymer such as a molten narrow molecular weight distribution, linear, ethylene copolymer, by incorporating into the thermoplastic polymer a wood rosin or wood rosin derivative.
摘要:
A process for reducing the odor of isotactic polypropylene containing an odor producing unsubstituted or substituted benzoic acid ester by admixing molten isotactic polypropylene with a compound capable of undergoing transesterification with the odor producing ester, said transesterification compound being (i) a partially esterified glycerol; (ii) an expoxide; (iii) a monofunctional or polyfunctional alcohol; (iv) an aliphatic acid ester; or (v) mixtures thereof wherein the transesterification compound is of such functionality and/or of sufficient molecular weight to yield an ester of a molecular weight of at least about 300 upon undergoing ester interchange with said odor causing benzoic acid ester.
摘要:
An impact polypropylene composition comprising:(i) isotactic polypropylene; and(ii) a copolymer of ethylene and an alpha-olefin comonomer having 3 to 8 carbon atoms, said copolymer (a) having a density of about 0.87 to about 0.90 gram per cubic centimeter and a crystallinity in the range of about 20 to about 35 percent by weight based on the weight of the copolymer and (b) being present in the composition in the range of about 20 to about 50 percent by weight based on the weight of the polypropylene.
摘要:
Chlorosulfonated alkylene-alkyl acrylate copolymers prepared by reacting, in the absence of a solvent or diluent, a granular alkylene-alkyl acrylate copolymer with a gaseous chlorosulfonating agent. The granular, elastomeric chlorosulfonated alkylene-alkyl acrylate copolymers can be used as extrudates about wires and cables and can be formed into film material characterized by excellent optical properties.
摘要:
Water-curable, silane modified chlorosulfonated olefinic polymers, particularly desirable for use as coverings about wires and cables, produced by reacting a mixture containing a chlorosulfonated olefinic polymer and a hydrolyzable silane having cyclic oxygen, sulfur or nitrogen functionality.
摘要:
A process for the production of EPDM comprising reacting ethylene, propylene, ethylidene norbornene, and hydrogen, in the gas phase, in a fluidized bed, under polymerization conditions, in the presence of a catalyst system comprising:(a) the reaction product of a vanadium compound and a electron donor;(b) at least one modifier having the formula BX.sub.3 or AlR.sub.(3-a) X.sub.a wherein each R is alkyl or aryl and is alike or different; each X is independently chlorine, bromine, or iodine; and a is 0, 1, or 2, wherein components (a) and (b) are impregnated into an inorganic support;(c) a halocarbon promoter; and(d) a hydrocarbyl aluminum cocatalyst with the following proviso:(i) the partial pressure of ethylene is in the range of about 25 to about 200 psi;(ii) the molar ratio of propylene to ethylene is in the range of about 0.2:1 to about 2:1;(iii) the molar ratio of hydrogen to ethylene is in the range of about 0.0001:1 to about 0.01:1; and(iv) the amount of ethylidene norbornene is about 1.5 to about 15 percent by weight based on the weight of the fluidized bed.