US4935079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of making polyethylene/metal laminates
Assignee: Crown Packaging UK Ltd
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Filing: 1988-05-19
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Granted: 1990-06-19
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Expires: 2008-05-19
Abstract
Abstract A method of making a laminated structure in which a polyethylene element is bonded directly to a metal substrate by the application of heat and pressure is characterised by the selection of the polyethylene, for the purpose of obtaining good adhesion, to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure co-polymerisation of ethylene and but-1-ene. The polyethylene may be pre-treated, e.g. by corona discharge, glow discharge or flame treatment to further improve the adhesion. The polyethylene element may be a film applied to one or both sides of the metal substrate which may be a sheet or foil.
Inventors
- 👤 Dominic I. Nelson-Ashley
- 👤 Graham M. Gossedge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:50
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/04; B32B15/08; B32B15/085; B32B27/00; B32B27/18; B32B27/20; B32B27/32; B32B27/322; B32B38/00; B32B38/0008; B32B38/0036; B32B2250/00; B32B2250/40; B32B2309/00; B32B2309/02; B32B2309/04; B32B2309/12; B32B2310/00; B32B2310/14; B32B2323/00; B32B2323/04; B32B2323/046; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T156/1044; Y10T156/1048
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
92 words
A method of making a laminated structure including an element of polyethylene bonded to a surface of a metal substrate, comprising the steps of engaging the polyethylene element with the surface of the metal substrate and bonding it directly to the metal substrate by the application of heat and pressure, the polyethylene being selected to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure co-polymerisation of ethylene and but-1-ene.
Claim 2
Independent Claim
92 words
A method of making a laminated structure including an element of polyethylene bonded to a surface of a metal substrate, comprising the steps of engaging the polyethylene element with the surface of the metal substrate and bonding it directly to the metal substrate by the application of heat and pressure, the polyethylene being selected to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure co-polymerisation of ethylene and but-1-ene.
Claim 3
Dependent Claim
44 words
A method according to claim 1 characterised in that the polyethylene element is in the form of a film, and said metal substrate is in the form of a sheet or foil, said film being engaged to a surface of the sheet or foil.
Claim 4
Dependent Claim
26 words
A method according to claim 1 characterised in that the polyethylene element and substrate are heated to a temperature within the range 200° to 300° C.
Claim 5
Dependent Claim
17 words
A method according to claim 1 characterised in that the pressure applied is less than 3500 kPa.
Claim 6
Dependent Claim
20 words
A method according to claim 4 characterised in the pressure applied is in the range of 200 to 2400 kPa.
Claim 7
Dependent Claim
24 words
A method according to claim 1 characterised in that the pressure is applied for a period in the range 0.1 seconds to 5 minutes.
Claim 8
Dependent Claim
24 words
A method according to claim 1 characterised in that the surface of the metal substrate is heated before the polyethylene element is engaged therewith.
Claim 9
Dependent Claim
23 words
A method according to claim 1 characterised in that the polyethylene element is heated before engagement with the surface of the metal substrate.
Claim 10
Dependent Claim
26 words
A method according to claim 1 characterised in that the polyethylene element is pretreated by a pretreatment chosen from corona discharge, glow discharge or flame treatment.
Claim 11
Dependent Claim
22 words
A method according to claim 1 characterised in that the metal surface is flame treated before the polyethylene element is engaged therewith.
Claim 12
Dependent Claim
46 words
A method according to claim 1, characterised in that, after initial engagement of the polyethylene and substrate at a temperature in the range 140° C. to 300° C. the laminated structure is heated without pressure at a temperature in the range 180° C. to 300° C.
Claim 13
Dependent Claim
29 words
A method according to claim 11 characterised in that the laminated structure is heated within the range 180° C. to 300° C. for a period not exceeding 5 minutes.
Claim 14
Dependent Claim
31 words
A method according to claim 2 characterised in that the polyethylene film is engaged with two opposed surfaces of the metal sheet or foil to form a laminated structure of polyethylene/metal/polyethylene.
Claim 15
Dependent Claim
30 words
A method according to claim 2 characterised in that the metal sheet or foil is engaged with both surfaces of the polyethylene film to form a laminated structure of metal/polyethylene/metal.
Claim 16
Dependent Claim
41 words
A method according to claim 2 characterised in that the metal substrate is a sheet or foil of a metal chosen from steel; steel coated with tin or chromium or chromium/chromium oxide or zinc; aluminium; aluminum alloy; nickel; zinc or copper.
Claim 17
Dependent Claim
27 words
A method according to claim 15 characterised in that the surface of the metal substrate has a conversion coating applied thereto before the polyethylene is engaged therewith.
Claim 18
Dependent Claim
30 words
A method according to claim 1, characterised in that the laminated structure is formed to an article by a process chosen from pressing, stamping, drawing, deep drawing or wall ironing.
Claim 19
Dependent Claim
29 words
A method according to claim 17, characterised in that the article is heated to a temperature in the range 200° C. to 300° after forming from the laminated structure.
Claim 20
Independent Claim
123 words
A method of making a laminated structure including an element of polyethylene bonded to a surface of a metal substrate, comprising the steps of engaging the polyethylene element with the surface of the metal substrate and bonding it directly to the metal substrate by the application of heat and pressure, the polyethylene being selected to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure co-polymerisation of ethylene and but-1-ene, and the polyethylene element, prior to initial engagement with the surface of the metal substrate, having not been pretreated by a pretreatment chosen from Corona discharge, glow discharge or flame treatment.
Claim 21
Independent Claim
123 words
A method of making a laminated structure including an element of polyethylene bonded to a surface of a metal substrate, comprising the steps of engaging the polyethylene element with the surface of the metal substrate and bonding it directly to the metal substrate by the application of heat and pressure, the polyethylene being selected to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure co-polymerisation of ethylene and but-1-ene, and the polyethylene element, prior to initial engagement with the surface of the metal substrate, having not been pretreated by a pretreatment chosen from Corona discharge, glow discharge or flame treatment.
Claim 22
Independent Claim
94 words
A method of making a laminated structure including an element of polyethylene bonded to a surface of a metal substrate, consisting essentially of the steps of engaging the polyethylene element with the surface of the metal substrate and bonding it directly to the metal substrate by the application of heat and pressure, the polyethylene being selected to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure copolymerization of ethylene and but-1-ene.
Claim 23
Independent Claim
94 words
A method of making a laminated structure including an element of polyethylene bonded to a surface of a metal substrate, consisting essentially of the steps of engaging the polyethylene element with the surface of the metal substrate and bonding it directly to the metal substrate by the application of heat and pressure, the polyethylene being selected to be a linear low density polyethylene having a density from 0.91 to 0.94 g/ml -1 and a melt flow index in the range 0.2 to 2.0 g/10 min, produced by low pressure copolymerization of ethylene and but-1-ene.
Claim 24
Dependent Claim
17 words
A method according to claim 20 wherein a bond strength of at least 70N/2.5 cm is achieved.
Claim 25
Dependent Claim
44 words
A method according to claim 20 wherein the bonding is carried out at a temperature within the range 200° to 300° C., a pressure in the range of 200 to 2400 kPa, and for a period in the range 0.1 seconds to 5 minutes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |