Claims
- 1. Homopolymers or copolymers obtained by a multistage continuous process for the polymerization of one or more olefins having the formula CH.sub.2 .dbd.CHR, in which R is hydrogen or R has from 1 to 10 carbon atoms and is an alkyl, cycloalkyl or aryl group, the process comprising:
- (A) a first stage of polymerization in which one or more of the olefins are polymerized, in one or more reactors, in the presence of a catalyst comprising the product of reaction between an alkyl-Al compound and a solid component in the form of spheroidal particles with a mean diameter of between 10 and 150 .mu.m, comprising a compound of a transition metal M.sup.I selected from the group consisting of Ti and V, not containing M-.pi. bonds, and a halide of Mg in active form, to produce an olefin homo or copolymer,
- (B) a treatment stage in which the product obtained in the first stage of polymerization (A) is:
- (a) brought into contact with a compound capable of deactivating the catalyst present in the stage (A); and thereafter
- (b) brought into contact with a compound of a transition metal M selected from the group consisting of Ti, Zr, V, or Hf containing at least one M-.pi. bond and optionally with an alkyl-Al compound;
- (C) a second stage of polymerization in which one or more of the olefins are polymerized, in one or more reactors, in the presence of the product obtained in treatment stage (B);
- and wherein the amount of olefin homo- or copolymer produced in the first stage polymerization (A) and treated in treatment stage (B) is between 10% and 90% by weight of the total amount of polymer produced in stages (A) and (C) combined.
- 2. Homopolymers and copolymers obtained in a multistage continuous process for the preparation of heterophase copolymers of propylene, the process comprising:
- (A) a first stage of polymerization in which, in one or more reactors, propylene and optionally ethylene and/or one or more olefins CH.sub.2 .dbd.CHR.sup.II, where R.sup.II is a hydrocarbon radical with 2-10 carbon atoms, are polymerized in the presence of a catalyst comprising the product of the reaction between an alkyl-Al compound, optionally an electron-donor compound (external donor) and a solid component in the form of spheroidal particles with a mean diameter of between 10 and 150 .mu.m, comprising at least one compound of a transition metal M.sup.I selected from titanium and vanadium and not containing M.sup.I -.pi. bonds, a magnesium halide in active form and optionally an electron-donor compound (internal donor), obtaining an olefin polymer having porosity, expressed as percentage of voids, greater than 10%, content of units derived from ethylene and/or from the CH.sub.2 .dbd.CHR.sup.II olefin less than 20% by weight, content of units derived from propylene greater than 80% by weight and insolubility in xylene greater than 60%;
- (B) a treatment stage in which the product obtained in stage (A) is:
- (a) brought into contact with a compound that is capable of deactivating the catalyst present in stage (A); and thereafter
- (b) brought into contact with a compound of a transition metal M selected from Ti, V, Zr and Hf containing at least one M-.pi. bond and optionally with an alkyl-Al compound;
- (C) a second stage of polymerization in which, in one or more reactors, one or more olefins CH.sub.2 .dbd.CHR, where R is hydrogen or R has from 1 to 10 carbon atoms and is an alkyl, cycloalkyl or aryl radical, are polymerized in the presence of the product obtained in stage (B), obtaining a substantially amorphous olefin (co)polymer in a quantity of between 20 and 80% by weight based on the total amount of polymer produced in stages (A) and (C).
- 3. Homopolymers and copolymers obtained in a multistage continuous process for the polymerization of one or more olefins having the formula CH.sub.2 .dbd.CHR, in which R is hydrogen or R has from 1 to 10 carbon atoms and is an alkyl, cycloalkyl, or aryl group, the process comprising:
- (A) a first stage of polymerization in which one or more of the olefins are polymerized, in one or more reactors, in the presence of a catalyst comprising the product of the reaction between an alkyl-Al compound and a solid component in the form of spheroidal particles with a mean diameter of between 10 and 150 .mu.m, comprising a compound of a transition metal M.sup.I selected from titanium and vanadium and not containing M.sup.I -.pi. bonds, and a halide of Mg in active form, to produce an olefin homo- or copolymer;
- (B) a treatment stage in which the product obtained in stage (A) is, in any order whatever:
- (a) brought into contact with water;
- (b) brought into contact with a compound of a transition metal M selected from Ti, V, Zr and Hf containing at least one M-.pi. bond and optionally with an alkyl-Al compound;
- (C) a second stage of polymerization in which one or more of the olefins are polymerized, in one or more reactors, in the presence of the product obtained in stage (B);
- and wherein the amount of olefin homo- or copolymer produced in the first stage polymerization (A) and treated in treatment stage (B) is between 10% and 90% by weight of the total amount of polymer produced in stages (A) and (C) combined.
Priority Claims (1)
Number |
Date |
Country |
Kind |
MI94A2028 |
Oct 1994 |
ITX |
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Parent Case Info
This is a divisional of U.S. application Ser. No. 08/461,691, filed Jun. 5, 1995 now U.S. Pat. No. 5,648,422.
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Divisions (1)
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Number |
Date |
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Parent |
461691 |
Jun 1995 |
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