摘要:
Catalytic component for the (co)polymerization of alpha-olefins consisting of the compound having the general formula VL.sub.3, wherein V is trivalent vanadium and L is a ligand selected from those having general formula (I): ##STR1## wherein R is selected from H and C.sub.1 -C.sub.20 monofunctional hydrocarbyl radicals; n is an integer between 2 and 13 excluding 4 and 5.
摘要:
Adhesive thermoplastic composition basically consisting of:1) dynamically vulcanized thermoplastic elastomer;2) polyethylene having a density equal to or less than 0.920 g/cm.sup.3 ;3) additives.The above composition is particularly useful for being firmly bound to articles made of EPM and/or EPDM vulcanized rubbers and for binding parts of vulcanized EPM and/or EPDM to each other.
摘要翻译:粘合热塑性成分基本上由以下组成:1)动态硫化热塑性弹性体; 2)密度等于或小于0.920g / cm 3的聚乙烯; 3)添加剂。 上述组合物特别可用于牢固地结合由EPM和/或EPDM硫化橡胶制成的制品以及将硫化EPM和/或EPDM的部分彼此粘合。
摘要:
In an improved process for producing elastomeric ethylene-propylene copolymers with a propylene content comprised within the range of from 22 to 38% by weight and a content of residual chlorine, coming from the co-catalyst, lower than 300 parts per million parts, the polymerization is carried out in suspension in the monomers in the liquid state, with vanadium triacetylacetonate and alkyl-Al compounds, and the obtained polymer is recovered without any washing steps.
摘要:
Elastomeric copolymer obtained by the polymerization of:a) a monomer selected from those having general formula CH.sub.2 .dbd.CR'--CO--OR, wherein R is a monofunctional radical selected from linear or branched C.sub.1 -C.sub.6 alkyl radicals;b) (meth)acrylonitrile;c) a third monomer selected from:c1) a chlorinated vinyl ester;c2) a mixture of an unsaturated carboxylic acid and an aliphatic or aromatic diepoxy compound;c3) a mixture consisting of a chlorinated vinyl ester and an unsaturated carboxylic acid.
摘要:
Process for the preparation of elastomeric copolymers of ethylene, wherein ethylene is copolymerized with an .alpha.-olefin, and possibly with a diene as termonomer, in the presence of a Ziegler-Natta catalyst including a solid component of catalyst based on titanium and aluminium, supported on magnesium chloride and obtained, in accordance with a special procedure, in the form of a spherical granular solid. This process produces elastomeric copolymers having a low crystallinity even with a high content of linked ethylene.
摘要:
Elastomeric composition vulcanizable with sulfur useful for the preparation of tyre treads which comprises: a) 100 parts of elastomeric mixture comprising from 20 to 100% by weight of an elastomer deriving from the polymerization of a monovinylarene with a conjugated diene, preferably a styrene-butadiene copolymer, the complement to 100 being selected from natural rubber, polybutadiene and other diolefin elastomers; b) from 10 to 150 parts of silica per 100 parts of (a); c) from 0 to 150 parts of carbon black per 100 parts of (a); characterized in that the elastomeric mixture (a) has an epoxidation degree from 0.7 to 8.0%.
摘要:
Process for the preparation in liquid phase of copolymers of ethylene with propylene and optionally another diene, in the presence of a catalyst selected from (a) Titanium salt supported on magnesium salt and (b) compound of Vanadium soluble in hydrocarbon solvents either supported on an inert material or prepolymerized, and a co-catalyst essentially consisting of an organic compound of Aluminium, and a possible chlorinated activator, characterized in that: 1) when the polymerization is almost complete, a solid material insoluble in the reaction environment and having an average diameter of between 0.001 and 200 microns is added to the reaction mixture; 2) the suspension of polymer and solid material are kept in contact for a sufficient time to obtain perfectly free-flowing polymeric particles; 3) the perfectly free-flowing polymeric particles of step (2) are recovered.
摘要:
A catalytic system to polymerize diolefinic monomers consists of a lanthanide salt, an organometallic compound of a metal belonging to groups I, II and III of the periodic table of elements and an organometallic compound of boron. The polymers obtained are characterized in that they have a high degree of 1,4 chain units and ratio between 1.4-cis/1,4-trans units which can vary as desired, and also a narrow molecular weight distribution.
摘要:
Method for the shortstopping of polymerizations of conjugated dienes possibly mixed with vinyl-substituted aromatic products in a radicalic emulsion polymerization process using a redox initiator, in particular radicalic emulsion polymerizations of butadiene possibly mixed with styrene or acrylonitrile, a method which enables the production of polymers without nitrosamines (NA) and/or their precursors.
摘要:
Organometallic complexes of lanthanides with a well-defined stoichiometry which can be used in the stereospecific polymerization of unsaturated monomers, can be represented by the general formula:Me(OR).sub.3 *(Me.sub.1 R.sup.1 R.sup.2 R.sup.3).sub.xwherein, Me represents a metal with atomic number 21, 39, or an atomic number between 57 and 71, OR is an alkoxylic group of an alcohol; Me represents a metal of the group IIIA, whereas R.sup.1, R.sup.2, R.sup.3 can be H, or a linear, branched or cyclo-aliphatic alkyl radical containing from 1 to 10 carbon atoms and x is an integer (3 or 4) and depends on the type of alkoxide used.The preparation of the complexes is described and their use in the stereospecific polymerization of unsaturated monomers.