Polyolefin blends compatibilized with a diblock copolymer

• US 6,114,443 A
• Filed: 06/23/1997
• Issued: 09/05/2000
• Est. Priority Date: 04/14/1995
• Status: Expired due to Fees

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Inventors: Lohse, David John, Yang, Henry Wu-Hsiang
• Primary Examiner(s): Wilson, Donald R.
• Application Number:
  US08/881,011
• Time in Patent Office: 1,170 Days
• Field of Search: 525/88, 525/95
• US Class Current: 525/88
• CPC Class Codes: C08F 297/08 polymerising mono-olefins
• CPC Class Codes: C08L 2205/08 containing additives to improve the compatibility between two polymers
• CPC Class Codes: C08L 23/04 Homopolymers or copolymers of ethene
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers

Abstract

The present invention is based on the discovery that diblock copolymers of ethylene and an atactic alpha-olefin that are prepared in the presence of a catalyst system comprising at least one metallocene compound and a non-coordinating anion are especially useful as compatibilizers with blends of polyethylene and isotactic poly-alpha-olefin homopolymers.

Claims

1. A composition comprising a blend of polyethylene and an isotactic poly-alpha-olefin homopolymer, together with a diblock copolymer compatibilizer of polyethylene block and an atactic poly-alpha-olefin block having no melting point, said isotactic poly-alpha-olefin homopolymer and said atactic poly-alpha-olefin block having the same monomer units, said diblock copolymer compatibilizer being formed by sequentially polymerizing ethylene and alpha-olefin in the presence of at least one metallocene compound and a non-coordinating anion, and the diblock copolymer having terminal unsaturation, at least 30% of which is vinylidene unsaturation.

2. The composition of claim 1 wherein the poly-alpha-olefin has from 2 to about 16 carbon atoms.

3. The composition of claim 2 wherein the compatibilizer is present in the range of from about 0.5 to about 10 wt %.

4. The composition of claim 3 wherein the olefin is propylene.

5. The composition of claim 1 wherein said isotactic poly-alpha-olefin has from 3 to about 16 carbon atoms, said blend of polyethylene and poly-alpha-olefin homopolymer having a ratio of polyethylene to poly-alpha-olefin in the range of 95:

5 to 5;

95, and the amount of said diblock copolymer being in the range of about 0.5 wt % to about 10 wt % based on the total weight of the blend.