Amorphous polypropylene based adhesive

• US 6,677,396 B2
• Filed: 12/23/2002
• Issued: 01/13/2004
• Est. Priority Date: 10/30/2000
• Status: Active Grant

• Current Assignee: Earthco Adhesives Technologies Limited
• Original Assignee: Gluco Limited
• Inventors: Johnson, Anthony Francis, Tsui, Sum-Wing
• Primary Examiner(s): Wu, David W.
• Assistant Examiner(s): CHEUNG, WILLIAM K
• Application Number:
  US10/221,415
• Publication Number:
  US 20030105211A1
• Time in Patent Office: 386 Days
• Field of Search: 524/487, 524/476, 524/478, 524/482, 524/484, 524/502, 524/507, 524/514
• US Class Current: 524/476
• CPC Class Codes: C08L 2207/14 Amorphous or atactic polypropylene
• 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 51/06 grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• CPC Class Codes: C09J 123/14 Copolymers of propene C09J123/16 takes precedence

Abstract

An adhesive composition comprises an amorphous polyalphaolefin, 50-90 wt %; a tackifier 10-40 wt %; a functionalised polypropylene trace-20 wt %; and optional further ingredients selected from stablisers, fillers and waxes; wherein the proportions of the amorphous polyalphaolefin, tackifier and functionalised polypropylene are selected to total 100%. A method of forming polypropylene packaging using the adhesive is also provided.

Claims

1. An adhesive composition comprising:

2. An adhesive composition as claimed in claim 1 wherein the polyalphaolefin has a melt viscosity at 190°

of 2,700-50,000, mPas.

3. An adhesive composition as claimed in claim 2 wherein the polyalphaofin has a melt viscosity at 190°

of 3,000-4,000 mPas.

4. An adhesive composition as claimed in claim 1 wherein the polyalphaolefin is atactic polypropylene.

5. An adhesive composition as claimed in claim 1 wherein the tackifier is selected from the group consisting of hydrocarbon resins, rosin esters and other resins of natural origin and hydrogenated resins.

6. An adhesive composition as claimed in claim 1 wherein the tackifier is a hydrocarbon oligomer resin with MW 500-1,500.

7. An adhesive as claimed in claim 6 wherein the tackifier is a hydrocarbon oligomer resin with MW 700.

8. An adhesive as claimed in claim 1 wherein the functionalised polypropylene is functionalized with 2,2′

-dimethyl-1,3-isopropenyl benzyl isocyanate or maleic anhydride.

9. A method of forming a polypropylene article comprising the steps of:

applying a quantity of adhesive as claimed in claim 1 to a first surface of a workpiece;

contacting a second surface of the workpiece to the adhesive; and

allowing the adhesive to cure to form said article wherein the first and second surfaces are secured together by the adhesive.

10. A method of forming an article as claimed in claim 9 wherein the article is polypropylene packaging.