Propylene Copolymers for Adhesive Applications

• US 20140080974A1
• Filed: 11/21/2013
• Published: 03/20/2014
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Jiang, Peijun, Brant, Patrick, Henning, David Aaron, Johnsrud, David Raymond, Sims, Charles Lewis
• Granted Patent: US 9,051,404 B2
• Time in Patent Office: Days
• US Class Current: 525/53
• CPC Class Codes: C08F 10/06 Propene
• CPC Class Codes: C08F 2/001 Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer C08F295/00, C08F297/00 take precedence
• CPC Class Codes: C08F 210/06 Propene
• CPC Class Codes: C08F 210/14 Monomers containing five or more carbon atoms
• CPC Class Codes: C08F 2500/09 Long chain branches
• CPC Class Codes: C08F 2500/11 Melt tension or melt strength
• CPC Class Codes: C08F 2500/17 Viscosity
• CPC Class Codes: C08F 2500/20 Activation energy or enthalpy
• CPC Class Codes: C08F 2500/21 Rubbery or elastomeric properties
• CPC Class Codes: C08L 23/142 at least partially crystalline copolymers of propene with other olefins
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: C09J 123/142 at least partially crystalline copolymers of propene with other olefins

Abstract

Disclosed herein is an in-reactor produced multi-component copolymer comprises a semi-crystalline component having a crystallinity of 20% or more, and an amorphous component having a crystallinity of 5% or less. The copolymer comprises at least 80 wt % of units derived from propylene and from about 1 to about 20 wt % of units derived from at least one C₆ to C₁₂ alpha-olefin. The copolymer has a viscosity at 190° C. of at least 530 mPa sec and a heat of fusion between about 10 and about 70 J/g. An adhesive containing the copolymer exhibits a good balance of adhesive properties and mechanical strength.

Claims

1. A process for producing an in-reactor produced multi-component copolymer comprising at least 80 wt % of units derived from propylene and up to 20 wt % of at least one comonomer selected from a group consisting of hexene-1 and octene-1, the process comprising:

(a) polymerizing propylene and one or more of the comonomers in a first reaction zone in the presence of a first catalyst system to produce a first polymer product, wherein the first catalyst system comprises a first polymerization catalyst capable of producing a semi-crystalline poly-alpha-olefin having a crystallinity of 20% or more, and a second polymerization catalyst capable of producing an amorphous poly-alpha-olefin having a crystallinity of 5% or less; and

(b) contacting the first polymer product under polymerization conditions with a second catalyst system in a second reaction zone separate from the first reaction zone.

2. The process of claim 1 wherein the second catalyst system is the same as the first catalyst system.

3. The process of claim 1 wherein additional propylene is supplied to said second reaction zone.

4. The process of claim 3 wherein the amount of propylene supplied to the first reaction zone is between about 30% and about 90% of the total propylene supplied to the first and second reaction zones.

5. The process of claim 3 wherein the molar ratio of propylene to said one or more of the comonomers in said first reaction zone is different from that in said second reaction zone.

6. A process for preparing a copolymer comprising at least 80 wt % of units derived from propylene and up to 20 wt % of at least one comonomer selected from a group consisting of hexene-1 and octene-1, the process comprising:

(a) polymerizing propylene and one or more of the comonomers in a first reaction zone in the presence of a first catalyst system capable of producing a semi-crystalline copolymer having a crystallinity of 20% or more; and

(b) contacting the semi-crystalline copolymer product with propylene in a second reaction zone separate from the first reaction zone and in the presence of a second catalyst system to produce said copolymer, the second catalyst system comprising a first polymerization catalyst capable of producing a crystalline poly-alpha-olefin having a crystallinity of 20% or more, and a second polymerization catalyst capable of producing an amorphous poly-alpha-olefin having a crystallinity of 5% or less.

7. The process of claim 6 wherein the molar ratio of propylene to said one or more of the comonomers in said second reaction zone is different from that in said first reaction zone.

8. A process for preparing a copolymer comprising at least 80 wt % of units derived from propylene and up to 20 wt % of at least one comonomer selected from a group consisting of hexene-1 and octene-1, the process comprising:

(a) polymerizing propylene in a first reaction zone in the presence of a first catalyst system to produce a first polymer product; and

(b) contacting the first polymer product with propylene and one or more of the comonomers in a second reaction zone separate from the first reaction zone and in the presence of a second catalyst system to produce said copolymer, the second catalyst system comprising a first polymerization catalyst capable of producing a crystalline poly-alpha-olefin having a crystallinity of 20% or more, and a second polymerization catalyst capable of producing an amorphous poly-alpha-olefin having a crystallinity of 5% or less.

9. The process of claim 8 wherein the first catalyst system is the same as the second catalyst system.

10. The process of claim 8 wherein the molar ratio of propylene to said one or more of the comonomers in said second reaction zone is different from that in said first reaction zone.