Patent US3878033A successfully refreshed from Google Patents.
US3878033A
Expired / Lapsed
US
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Forming parisons with nucleated inner layer
Assignee: Phillips Petroleum Co
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Filing: 1971-03-10
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Granted: 1975-04-15
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Expires: 1991-03-10
Abstract
Abstract Tubular parisons suitable for blow molding into high strength transparent hollow objects are formed having a thin inner layer of nucleated polypropylene and a thicker outer layer of polypropylene containing no nucleating agent.
Inventors
- 👤 Frederick Zavasnik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:12
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/22; B29C48/00; B29C48/001; B29C48/0013; B29C48/0015; B29C48/0016; B29C48/16; B29C48/18; B29C48/21; B29C48/03; B29C48/09; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/139; Y10T428/1393; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
55 words
AN INDIVIDUAL PREFORMED TUBULAR PARISON COMPRISING AN INNER TUBULAR LAYER OF POLYPROPYLENE OF 5-50 MILS WALL THICKNESS, SAID POLYPROPYLENE CONTAINING 0.005-1 WEIGHT PERCENT OF A NUCLEATING AGENT, AND AN OUTER INTEGRALLY JOINED LAYER OF POLYPROPYLENE, SAID OUTER LAYER HAVING A THICKNESS OF 60-300 MILS AND SAID POLYPROPYLENE COMPRISING SAID OUTER LAYER HAVING NO NUCLEATING AGENT.
Claim 2
Dependent Claim
55 words
AN INDIVIDUAL PREFORMED TUBULAR PARISON COMPRISING AN INNER TUBULAR LAYER OF POLYPROPYLENE OF 5-50 MILS WALL THICKNESS, SAID POLYPROPYLENE CONTAINING 0.005-1 WEIGHT PERCENT OF A NUCLEATING AGENT, AND AN OUTER INTEGRALLY JOINED LAYER OF POLYPROPYLENE, SAID OUTER LAYER HAVING A THICKNESS OF 60-300 MILS AND SAID POLYPROPYLENE COMPRISING SAID OUTER LAYER HAVING NO NUCLEATING AGENT.
Claim 3
Dependent Claim
13 words
An article according to claim 1 wherein said nucleating agent is sodium benzoate.
Claim 4
Dependent Claim
28 words
AN ARTICLE ACCORDING TO CLAIM 1 WHEREIN SAID INNER LAYER OF POLYPROPYLENE HAS A RELATIVELY HIGH MELT FLOW AND SAID OUTER LAYER HAS A RELATIVELY LOW MELT FLOW.
Claim 5
Dependent Claim
39 words
An article according to claim 1 wherein the polymer comprising said inner layer has a melt flow within the range of 3-10 and when said polypropylene comprising said outer layer has a melt flow within the range of 0.5-2.9.
Claim 6
Dependent Claim
17 words
An article according to claim 1 wherein said inner layer has a wall thickness of 9-15 mils.
Claim 7
Dependent Claim
17 words
An article according to claim 1 wherein said outer layer has a wall thickness of 100-150 mils.
Claim 8
Dependent Claim
38 words
An article according to claim 1 wherein said nucleating agent is present in said polypropylene of said inner layer in an amount within the range of 0.01 to 0.05 weight percent based on the weight of said polypropylene.
Claim 9
Dependent Claim
28 words
An article according to claim 7 wherein said inner layer has a wall thickness of 9-15 mils and said outer layer has a wall thickness of 100-150 mils.
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 |