# US 11,078,304 B2 · Process for preparing heterophasic propylene copolymers

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,078,304 B2
- Document ID: US11078304B2
- Status: Granted
- Kind: B2
- Application number: 16/624,191
- Filed: 2018-06-14
- Published: 2020-04-30
- Granted: 2021-08-03
- Earliest claimed: 2017-07-07
- Assignees: Borealis AG
- Applicants: Borealis AG
- Inventors: Luigi Maria Cristoforo Resconi; Wilfried Toltsch; Ville Virkkunen; Ismo Lehtiniemi; Noureddine Ajellal
- Web page: https://patentgrep.com/patent/US11078304B2

## CPC

- C08F 4/65927: {two cyclopentadienyl rings being mutually bridged}
- C08L 23/12: Polypropene
- C08F 2/01: characterised by special features of the polymerisation apparatus used
- C08F 2/34: Polymerisation in gaseous state
- C08F 4/65912: {in combination with an organoaluminium compound}
- C08F 210/06: Propene
- C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers
- C08F 2420/07: Heteroatom-substituted Cp, i.e. Cp or analog where at least one of the substituent of the Cp or analog ring is or contains a heteroatom
- C08L 2205/02: containing two or more polymers of the same C08L -group
- C08L 2207/02: Heterophasic composition
- C08L 2314/06: Metallocene or single site catalysts
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

Process for producing a heterophasic propylene copolymer using a specific class of metallocene complexes in a multistage polymerization process including a gas phase polymerization step. The invention further relates to the use of catalysts which comprise a specific class of metallocene complexes to produce a heterophasic propylene copolymer in a multistep process including a gas phase polymerization step.

## Claims

### Claim 1

A process for the preparation of a heterophasic propylene copolymer, the process comprising: preparing the heterophasic propylene copolymer in the presence of a single site catalyst comprising:
(i) a complex of formula (I):
wherein
M is zirconium or hafnium;
each X independently is a sigma-donor ligand
L is a divalent bridge selected from —R′2C—, —R′2C—CR′2—, —R′2Si—, —R′2Si—SiR′2—, or —R′2Ge—, wherein each R′ is independently a hydrogen atom or a C1-C20-hydrocarbyl group optionally containing one or more heteroatoms of Group 14-16 of the periodic table or fluorine atoms, or optionally two R′ groups taken together can form a ring;
R1 and R1′ are each independently hydrogen, C5-C10-aryl or a group —CH(Rx)2 wherein each Rx is independently H or a C1-10 hydrocarbyl group, and optionally the two Rx taken together can form a ring,
R2 and R2′ are each independently hydrogen, C5-C10-aryl or a group —C(Ry)3 wherein each Ry is independently H or a C1-10 hydrocarbyl group, or optionally two or three Ry groups taken together can form a ring,
whereby at least one of R1 or R2 and one of R1′ or R2′ is different from hydrogen, and
whereby R2 together with one of R1, as well as R2′ together with one of R1′ may be part of a further mono- or multicyclic ring condensed to the phenyl ring,
R3 and R3′ are each independently a linear C1 to C6 hydrocarbyl group or a branched or cyclic C4 to C10 hydrocarbyl group, whereby the groups are not branched in α-position,
R4 and R4′ are each independently a tertiary C4 to C10 hydrocarbyl group,
R5 and R5′ are each independently a linear or branched C1 to C10 alkyl group or an C5-C10-aryl group, and
(ii) a cocatalyst comprising a compound of a group 13 metal,
the heterophasic propylene copolymer comprising:
(a-1) a matrix (M) that is a polypropylene homopolymer or propylene-ethylene random copolymer, and
(a-2) an elastomeric propylene-ethylene copolymer (E) dispersed in said matrix (M),
wherein the elastomeric propylene-ethylene copolymer (E) has:
(i) an intrinsic viscosity (IV) determined according to DIN ISO 1628/1 (in decalin at 135° C. in a range of from 3.1 to 8.0 dl/g,
(ii) an ethylene comonomer content in a range of from 10.0 to 80.0 wt %,
(iii) optionally a second comonomer selected from 1-butene in an amount of from 0.0 to up to 20.0 wt % or 1-hexene in an amount of from 0.0 up to 10.0 wt %, and
(iv) a xylene soluble (XS) fraction (determined according to ISO 16152 at 25° C.) of at least 50.0 wt %, and
wherein a xylene soluble fraction (determined according to ISO 16152 at 25° C.) of the heterophasic propylene copolymer is in a range of from 5.0 to 50.0 wt %.

### Claim 2 (depends on 1)

The process according to claim 1, wherein in the formula (I) each X is independently a hydrogen atom, a halogen atom, C1-6 alkoxy group, C1-6 alkyl, phenyl or benzyl group.

### Claim 3 (depends on 1)

The process according to claim 1, wherein in the formula (I) L is dimethylsilyl, methylcyclohexylsilyl (Me-Si-cyclohexyl), ethylene or methylene.

### Claim 4 (depends on 1)

The process according to claim 1, wherein in the formula (I):
R3 and R3′ are the same and are linear C1 to C4 alkyl group, and
R4 and R4′ are each independently a tertiary C4 to C6 alkyl group.

### Claim 5 (depends on 1)

The process according to claim 1, wherein in the formula (I):
M is zirconium,
X is independently a halogen atom, C1-4 alkoxy group, C1-4 alkyl, phenyl or benzyl group,
L is dimethylsilyl,
R1 and R1′ are the same and are hydrogen or a group —CH2Rx wherein Rx is either H or a C1-3 alkyl group,
R2 and R2′ are the same and are hydrogen or a group —C(Ry)3 wherein Ry is either H or a C1-3 alkyl group,
whereby either R1 and R1′ or R2 and R2′ are hydrogen,
R3 and R3′ are the same and are a linear C1 to C4 hydrocarbyl group,
R4 and R4′ are each a tert-butyl group, and
R5 and R5′ are each a linear C1 to C4 alkyl group.

### Claim 6 (depends on 1)

The process according to claim 1, wherein the complex of formula (I) is rac-Me2Si(2-Me-4-(3,5-Me2Ph)-5-OMe-6-tBu-Ind)2ZrCl2 or rac-Me2Si(2-Me-4-(4-tBu-Ph)-5-OMe-6-tBu-Ind)2ZrCl2.

### Claim 7 (depends on 1)

The process according to claim 1, wherein the cocatalyst is an aluminoxane cocatalyst.

### Claim 8 (depends on 7)

The process according to claim 7, wherein in the formula (I) M is Zr and a ratio of Al/Zr is from 150 to 1000 mol/mol.

### Claim 9 (depends on 1)

The process according to claim 1, wherein the single site catalyst is in solid particulate form free from an external carrier.

### Claim 10 (depends on 9)

The process according to claim 9, wherein the single site catalyst is prepared by forming a liquid/liquid emulsion system, which comprises a solution of components (i) and (ii) dispersed in a solvent so as to form dispersed droplets, and solidifying said dispersed droplets to form solid particles.

### Claim 11 (depends on 1)

The process according to claim 1, wherein the heterophasic copolymer is prepared in a multistage process comprising at least two reactors connected in series including at least one gas phase polymerization step.

### Claim 12 (depends on 1)

The process according to claim 1, wherein the matrix (M) of the heterophasic polypropylene copolymer is a polypropylene homopolymer with a molecular weight distribution (MWD; Mw/Mn as measured with GPC) in a range of from 2.5 to 7.0.

### Claim 13 (depends on 1)

The process according to claim 1 further comprising:
(A) polymerizing propylene and optionally ethylene in at least a first reactor and optionally a second reactor to form a polypropylene homopolymer or a propylene-ethylene random copolymer, said polypropylene homopolymer or propylene-ethylene random copolymer forming the matrix (M), and
(B) polymerizing propylene and ethylene in a gas phase reactor in the presence of the polypropylene homopolymer or propylene-ethylene random copolymer prepared in step (A) to form an elastomeric propylene-ethylene copolymer (E).

### Claim 14 (depends on 13)

The process according to claim 13, further comprising:
(a) polymerizing in a first reactor propylene and optionally ethylene to obtain a first polypropylene homopolymer or propylene-ethylene random copolymer fraction (R-PP1),
(b) transferring said first polypropylene homopolymer or propylene-ethylene random copolymer fraction (R-PP1) into a second reactor,
(c) polymerizing in said second reactor in the presence of the first polypropylene homopolymer or propylene-ethylene random copolymer fraction (R-PP1) propylene and optionally ethylene to obtain a second polypropylene homopolymer or propylene-ethylene random copolymer fraction (R-PP2), wherein said first polypropylene homopolymer or propylene-ethylene random copolymer fraction (R-PP1) and said second polypropylene homopolymer or propylene-ethylene random copolymer fraction (R-PP2) form the matrix (M),
(d) transferring said matrix (M) into a third reactor, wherein said third reactor is a gas phase reactor,
(e) polymerizing in said third reactor in the presence of the matrix (M) propylene, and
ethylene to obtain an elastomeric propylene-ethylene copolymer (E), wherein said matrix (M) and said elastomeric propylene-ethylene copolymer (E) form the heterophasic propylene copolymer.