Propylene copolymers for adhesive applications

• US 9,051,404 B2
• Filed: 11/21/2013
• Issued: 06/09/2015
• Est. Priority Date: 09/29/2006
• Status: Expired due to Fees

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Jiang, Peijun, Brant, Patrick, Johnsrud, David Raymond, Sims, Charles Lewis, Henning, David Aaron
• Primary Examiner(s): Krylova, Irina
• Application Number:
  US14/086,298
• Publication Number:
  US 20140080974A1
• Time in Patent Office: 565 Days
• US Class Current: 1/1
• 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 preparing a multi-component copolymer comprising a semi-crystalline component having a crystallinity of 20% or more, and an amorphous component having a crystallinity of 5% or less, wherein the copolymer comprises at least 80 wt % of units derived from propylene and from 1 wt % 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 the semi-crystalline component having a crystallinity of 20% or more; and

(b) contacting the semi-crystalline component of step (a) with additional propylene in a second reaction zone separate from the first reaction zone and in the presence of the first catalyst system and a second catalyst system to produce said copolymer, the second catalyst system capable of producing the amorphous component having a crystallinity of 5% or less;

wherein the first catalyst system comprises di(p-triethylsilylphenyl)methylene(cyclopentadienyl)(3,8-di-t-butylfluorenyl)MR, where M is zirconium or hafnium and R is Cl or CH₃, and the second catalyst system comprises rae-dimethylsilyl bis(2-methyl-4-phenylindenyl)M*R*₂, where M* is zirconium or hafnium, and R* is Cl or CH₃;

wherein the copolymer has a viscosity at 190°

C. of 530 to 1500 mPa sec, a heat of fusion between 20 and 50 J/g, a branching index of 0.764 to 0.95 as measured at z-average molecular weight, an elongation of 400 to 1434.5%, and a toughness of 7 to 53 megajoule/m²;

wherein the weight averaged molecular weight of the semi-crystalline component is from 5,000 to 100,000;

wherein the semi-crystalline component is incorporated into the amorphous component so as to form a branched cross-product with both amorphous and semi-crystalline characteristics; and

wherein the weight ratio of the semi-crystalline component to the amorphous component is from 90;

10 to 30;

70.

2. The process of claim 1 wherein the molar ratio of the propylene to said one or more of the comonomers in said second reaction zone is different from that in said first reaction zone.

3. The process of claim 1 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 zone.