US5313987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer plastic pipe comprising an outer polyamide layer and a layer of a molding formed from a mixture of thermoplastic polyester and a compound having at least two isocyanate groups
Assignee: Evonik Operations GmbH
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Filing: 1993-04-16
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Granted: 1994-05-24
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Expires: 2013-04-16
Abstract
Abstract A plastic pipe having improved resistance to methanol-containing fuels and improved mechanical properties is provided. This is achieved by a multilayer plastic pipe consisting of at least one outer layer based on polyamide and at least one layer of a linear, crystalline polyester modified with isocyanates. With the aid of the invention it is possible to obtain plastic pipes having improved barrier properties against methanol-containing fuels and dimensional stability and mechanical load-bearing capacity.
Inventors
- 👤 Stefan Rober
- 👤 Joachim Mugge
- 👤 Roland Feinauer
- 👤 Hans Jadamus
- 👤 Hans-Dieter Herrmann
- 👤 Hans Ries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:21
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B7/00; B32B7/04; B32B7/10; B32B1/00; B32B1/08; B32B27/34; B32B27/36; C; C09; C09J; C09J175/00; C09J175/04; C09J175/06; B32B2307/00; B32B2307/70; B32B2307/704; B32B2307/718; Y; Y10; Y10S; Y10S138/00; Y10S138/07
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
81 words
A multilayer plastic pipe comprising I) at least one outer layer comprising polyamide and II) at least one layer of a molding formed from a mixture of a) 99 to 60% by weight of a linear partially crystalline thermoplastic polyester and b) 1 to 40% by weight of a compound having at least two isocyanate groups, wherein the isocyanate groups originating from component IIb being contained in component II in a concentration between 0.03 and 3% by weight, adhesively bonded together.
Claim 2
Dependent Claim
81 words
A multilayer plastic pipe comprising I) at least one outer layer comprising polyamide and II) at least one layer of a molding formed from a mixture of a) 99 to 60% by weight of a linear partially crystalline thermoplastic polyester and b) 1 to 40% by weight of a compound having at least two isocyanate groups, wherein the isocyanate groups originating from component IIb being contained in component II in a concentration between 0.03 and 3% by weight, adhesively bonded together.
Claim 3
Dependent Claim
25 words
The multilayer plastic pipe according to claim 1, wherein at least 50% of the end groups in the polyamide of component I are amino groups.
Claim 4
Dependent Claim
51 words
The multilayer plastic pipe according to claim 1 or 2, wherein the molding of component II is formed from a mixture of a) 98 to 70% by weight of a linear partially crystalline thermoplastic polyester and b) 2 to 30% by weight of a compound having at least two isocyanate groups.
Claim 5
Dependent Claim
49 words
The multilayer plastic pipe according to claim 1 or 2, wherein the molding of component II is formed from mixture of a) 97.5 to 90% by weight of a linear partially crystalline polyester and b) 2.5 to 10% by weight of a compound having at least two isocyanate groups.
Claim 6
Dependent Claim
32 words
The multilayer plastic pipe according to claim 1, wherein the isocyanate groups in the molding of component II are present in a concentration between 0.3 and 1.8% by weight of the molding.
Claim 7
Dependent Claim
27 words
The multilayer plastic pipe according to claim 1 wherein the isocyanate group containing compound has at least one isocyanurate, urethane, acylated urea, biuret, carbodiimide or ester group.
Claim 8
Dependent Claim
26 words
The multilayer plastic pipe according to claim 1, wherein the isocyanate group containing compound is isophorone diisocyanate, an isocyanurate derived from isophorone diisocyanate, or mixture thereof.
Claim 9
Dependent Claim
21 words
The multilayer plastic pipe according to claim 1, wherein the isocyanate group containing compound contains an isocyanate blocked by a lactam.
Claim 10
Dependent Claim
20 words
The multilayer plastic pipe according to claim 1, wherein the plastic pipe contains three or more layers I and II.
Claim 11
Dependent Claim
17 words
A process of using the multilayer plastic pipe according to claim 1 comprising transporting chemical agents therein.
Claim 12
Dependent Claim
24 words
A process of using the multilayer plastic pipe according to claim 8 or 9, comprising conveying fuel or brake, cooling, or hydraulic fluids therein.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |