Enhanced lubrication in polyolefin closure with polyolefin grafted cyclodextrin

• US 7,385,004 B2
• Filed: 12/27/2004
• Issued: 06/10/2008
• Est. Priority Date: 12/10/2002
• Status: Active Grant

• Current Assignee: Verdant Technologies, Inc.
• Original Assignee: Cellresin Technologies, LLC
• Inventors: Wood, Willard E.
• Primary Examiner(s): Gulakowski; Randy
• Assistant Examiner(s): Asinovsky; Olga
• Application Number:
  US11/023,288
• Publication Number:
  US 20050131119A1
• Time in Patent Office: 1,261 Days
• Field of Search: 525/54.2, 525/64, 428/34.1, 428/35.7, 428/36.92, 428/355.EN, 428/339
• US Class Current: 525/54.2
• CPC Class Codes: C08B 37/0012 Cyclodextrin [CD], e.g. cycle with 6 units (alpha), with 7 units (beta) and with 8 units (gamma), large-ring cyclodextrin or cycloamylose with 9 units or more; Derivatives thereof
• CPC Class Codes: C08F 210/18 with non-conjugated dienes, e.g. EPT rubbers
• CPC Class Codes: C08F 8/14 Esterification
• CPC Class Codes: C08F 8/46 Reaction with unsaturated dicarboxylic acids or anhydrides thereof, e.g. maleinisation
• CPC Class Codes: C08G 81/02 at least one of the polymers being obtained by reactions involving only carbon-to-carbon unsaturated bonds
• CPC Class Codes: C08G 81/024 Block or graft polymers containing sequences of polymers of C08C or C08F and of polymers of C08G
• CPC Class Codes: C08L 23/04 Homopolymers or copolymers of ethene
• 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 5/16 Cyclodextrin; Derivatives thereof
• CPC Class Codes: C08L 51/06 grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• CPC Class Codes: C08L 87/005 Block or graft polymers not provided for in groups C08L1/00 - C08L85/04
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1397 Single layer [continuous layer]
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component
• CPC Class Codes: Y10T 428/2878 including addition polymer from unsaturated monomer

Abstract

Thermoplastic polymer compositions in a closure can comprise a polymer, a modified vinyl polymer and a slip agent or polymer lubricant said modified polymer having a moiety comprising a cyclodextrin compound. The cyclodextrin compound, locked into the polymer structure, can absorb impurities, permeants, or other undesirable volatile materials. The cooperation between the lubricant, the cyclodextrin grafted onto the thermoplastic polymer and the polymer structure can provide barrier properties to a film, web or other polymer structure and a surface with substantial lubricity.

Claims

1. A closure comprising a cap, the cap having a weight of about 0.75 to 1.25 grams and comprising a blend of a polyolefin resin, a lubricant and a modified polyolefin resin, the modified polyolefin resin comprising a polymethylene backbone having randomly substituted covalently bonded groups derived from a cyclodextrin compound, the cap comprising about 100 parts by weight of the polyolefin resin, about 0.05 to 4 parts by weight fatty acid amide lubricant and about 0.01 to 10 parts by weight of the modified polyolefin;

wherein the cyclodextrin compound is substantially free of a compound in the central pore of the cyclodextrin ring and the concentration of lubricant at the surface of the cap is greater than the concentration of lubricant in the polyolefin resin.

2. The closure of claim 1 wherein the polyolefin comprises a melt index of about 0.5 to 100 g-10 min.⁻

1 and the modified polyolefin is derived from a polyolefin with a melt index of 0.7 to 200 g-10 min<sup>−

1</sup>.

3. The closure of claim 1 wherein the polyolefin comprises a melt index of about 1 to 75 g-10 min.⁻

1 and the modified polyolefin is derived from a polyolefin having a melt index of about 1 to 100 g-10 min.<sup>−

1</sup>.

4. The closure of claim 1 wherein the polyolefin comprises a polyethylene copolymer, a polypropylene copolymer or mixtures thereof.

5. The closure of claim 1 wherein the modified polyolefin comprises a modified polyethylene, a modified polypropylene or mixtures thereof.

6. The closure of claim 1 wherein the closure lubricant comprises about 0.1 to 3 wt % of a fatty acid amide based on the composition.

7. The closure of claim 6 wherein the fatty acid amide comprises a C_10-24 fatty acid amide, or mixtures thereof.

8. The closure of claim 4 wherein the polyolefin comprises a poly(ethylene-co-propylene).

9. The closure of claim 4 wherein the modified polyolefin comprises a modified poly(ethylene-co-propylene).

10. The closure of claim 1 wherein the modified polyolefin comprises a cyclodextrin bonded to a maleic acid modified polyolefin wherein the maleic acid modified polyolefin comprises about 0.02 to 5 weight percent maleic anhydride groups.

11. The closure of claim 1 wherein the modified polyolefin comprises a cyclodextrin bonded to a maleic acid modified polyolefin wherein the maleic acid modified polyolefin comprises about 0.02 to 2 weight percent maleic anhydride groups.

12. The closure of claim 4 wherein the polyethylene comprises a low-density polyethylene.

13. The closure of claim 4 wherein the polyethylene comprises a linear low-density polyethylene.

14. The closure of claim 4 wherein the polyethylene comprises a high-density polyethylene.

15. The closure of claim 1 wherein the cyclodextrin compound has a substituent substantially on at least one —

OH group.

16. The closure of claim 1 wherein the cyclodextrin compound further has at least one substituent at the −

2, 3 or the −

6 position of a glucose moiety.