US3877490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steel pipes provided with plastic coatings
Assignee: JFE Engineering Corp
•
Filing: 1973-06-08
•
Granted: 1975-04-15
•
Expires: 1993-06-08
Abstract
Abstract In a steel pipe provided with a corrosion resistant layer of plastic and a protective layer of plastic applied onto the corrosion resistant layer through an intermediate layer of an antifusion agent, the antifusion agent comprises a mixture of two or more synthetic resins of the polyolefin series. The synthetic resins have lower molecular weight than the plastics utilized to form the corrosion resistant layer and the protective layer and solidify at room temperature to form a film.
Inventors
- 👤 Yoshio Tsubouchi
- 👤 Noboru Shima
- 👤 Hiroyuki Tanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:55
CPC Classifications
F; F16; F16L; F16L58/00; F16L58/18; F16L58/181; Y; Y10; Y10S; Y10S138/00; Y10S138/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
94 words
IN A STEEL PIPE PROVIDED WITH A CORROSION RESISTANT LAYER OF PLASTIC AND A PROTECTIVE LAYER OF PLASTIC APPLIED ONTO SAID CORROSION RESISTANT LAYER THROUGH AN INTERMEDIATE COEXTENSIVE LAYER OF AN ANTIGUSION AGENT, THE IMPROVEMENT WHEREIN SAID ANTIFUSION AGENT COMPRISES A MIXTURE OF TWO OR MORE OF SYNTHETIC RESINS OF THE POLYOLEFIN SERIES, SAID MIXTURE OF SYNTHETIC RESINS HAVING LOW MOLECULAR WEIGHT THAN SAID PLASTICS FORMING SAID CORROSION RESISTANT LAYER AND SAID PROTECTIVE LAYER AND SOLIDIFYING AT ROOM TEMPERATURE TO FORM A FILM WHEREBY FUSION AND SLIPPAGE BETWEEN THE LAYERS OF PLASTIC IS PREVENTED.
Claim 2
Dependent Claim
94 words
IN A STEEL PIPE PROVIDED WITH A CORROSION RESISTANT LAYER OF PLASTIC AND A PROTECTIVE LAYER OF PLASTIC APPLIED ONTO SAID CORROSION RESISTANT LAYER THROUGH AN INTERMEDIATE COEXTENSIVE LAYER OF AN ANTIGUSION AGENT, THE IMPROVEMENT WHEREIN SAID ANTIFUSION AGENT COMPRISES A MIXTURE OF TWO OR MORE OF SYNTHETIC RESINS OF THE POLYOLEFIN SERIES, SAID MIXTURE OF SYNTHETIC RESINS HAVING LOW MOLECULAR WEIGHT THAN SAID PLASTICS FORMING SAID CORROSION RESISTANT LAYER AND SAID PROTECTIVE LAYER AND SOLIDIFYING AT ROOM TEMPERATURE TO FORM A FILM WHEREBY FUSION AND SLIPPAGE BETWEEN THE LAYERS OF PLASTIC IS PREVENTED.
Claim 3
Dependent Claim
30 words
The steel pipe according to claim 1 wherein said antifusion agent comprises a mixture of two or more of synthetic resins of the polyolefin series and a heavy paraffin oil.
Claim 4
Dependent Claim
41 words
The steel pipe accoRding to claim 1 wherein said synthetic resins of the polyolefin series are selected from the group consisting of polyethylene of molecular weight of 500-2,000, polypropylene of molecular weight of 2,000-8,000 and polybutene of molecular weight of 200-1,500.
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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |