摘要:
Disclosed are polymers and copolymers of CH.sub.2 .dbd.CHR alpha olefins where R is hydrogen or a 1-6 carbon atom alkyl radical, containing in the chain from 0.1 to 40 mole % of monomeric units ##STR1## where X is selected from the group consisting of (CH.sub.2).sub.r CH.sub.2 CH.sub.2 Y ##STR2## where r=0-10, Y is a halogen atom, R.sup.1 is a hydrocarbon radical with 1-18 carbon atoms.
摘要:
A process for the production of primarily syndiotactic vinyl aromatic polymers by polymerizing or copolymerizing vinyl aromatic monomers such as styrene or styrene derivatives in the presence of a catalyst system comprising the product of the reaction between:a) a compound of a transition metal (M) different from titanium and containing at least a bond M-O, M-C, M-N, M-P, M-S or M-halogen, andb) an organoaluminum compound containing at least an oxygen atom bound to the aluminum atom or bound between two aluminum atoms.Compound a) can be used as such or may be supported on a suitable carrier.
摘要:
Essentially syndiotactic crystalline copolymers of propylene with minor proportions of 1-butene, endowed with good mechanical properties, lowered melting point and limited solubility in xylene at 25.degree. C. and the process for their preparation by polymerizing mixtures of propylene with 1-butene, by using catalysts obtained form stereorigid and chiral zirconium and hafnium compounds and from polymethylalumoxane compounds.
摘要:
Crystalline copolymers of ethylene and alpha-olefins CH.sub.2 .dbd.CHR in which R is an alkyl group having 2 to 8 carbon atoms, containing 0.5 to 3% by moles of polymerized alpha-olefin and having a density lower than 0.945 g/cc are obtained by polymerizing, in the gas phase, mixtures of ethylene and the alpha-olefins in contact with catalysts prepared from (1) Ti compounds supported on Mg halides and (2) organometallic compounds, which are active in the polymerization of ethylene but exhibit little, if any, activity in the homo- or copolymerization of the alpha-olefins.
摘要:
Disclosed are catalysts for the polymerization of ethylene and of mixtures thereof with olefins, comprising the product obtained by reacting the following components:(a) an Al-alkyl compound;(b) an electron-donor compound containing at least a nitrogen atom, said compound being reactive towards MgCl.sub.2, but not towards Al-triethyl; and(c) the reaction product between a titanium compound containing at least a titanium-halogen bond and an anhydrous magnesium halide.The obtained (co)polymers have a very narrow molecular weight distribution which renders them particularly suitable for some applications, such as injection molding.
摘要:
Novel crystalline copolymers of propylene with minor proportions of ethylene and/or alpha-olefins, endowed with very good mechanical properties, a low melting point and a limited solubility in xylene at 25° C., and the process for preparing them by means of the polymerization of mixtures of propylene with ethylene and/or alpha-olefins of suitable composition, by using catalysts obtained from stereorigid and chiral compounds of zirconium, and methylalumoxanic compounds.
摘要:
A process for continuously producing an elastomeric composition includes providing at least one extruder, metering and feeding at least one elastomer, at least one filler, and ingredients different from elastomers and fillers into the at least one extruder, mixing and dispersing the at least one filler and the ingredients different from elastomers and fillers into the at least one elastomer using the at least one extruder, and extruding a resulting elastomeric composition. The at least one extruder includes the housing and at least one screw rotatably mounted in the housing. The housing includes at least one feed opening and a discharge opening. At least one of the ingredients different from elastomers and fillers includes a subdivided product including one or more minor ingredients dispersed in at least one thermoplastic binding agent. An apparatus for continuously producing the elastomeric composition is also disclosed.
摘要:
Elastomeric ethylene/propylene or ethylene/propylene/polyene copolymers containing small amounts of one or more &agr;-olefins are prepared by a slurry process wherein the polymerization reaction is carried out in a mixture of liquid propylene and alpha-olefin.
摘要:
Catalysts for the polymerization of olefins, comprising the product of the reaction between:A) a cyclopentadienyl compound of Ti, Zr or Hf;B) an alumoxane compound of formula: ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, the same or different from each other, are alkyl, alkenyl or alkylaryl radicals having 2 to 20 carbon atoms.
摘要:
Imidized acrylic polymers obtained by means of the reaction of an acrylic resin in the molten state, with at least one modifying agent having the general formula:R--X--NH--R' (I)wherein:R and R' are either equal to, or different from, each other and represent hydrogen or an alkyl, cycloalkyl; aryl or alkylaryl radical containing from 1 to 20 carbon atoms, andX is a bifunctional radical selected from the group consisting of: --CO--, --CONH--, --NHCO--, --OCO--, --SO.sub.2 --, --C.sub.6 H.sub.4 SO.sub.2 --.