US3862284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing blow molded thermoplastic articles having improved barrier properties
Assignee: Air Products and Chemicals Inc
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Filing: 1973-05-10
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Granted: 1975-01-21
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Expires: 1993-05-10
Abstract
Abstract The barrier properties of blow molded thermoplastic articles are greatly improved if a blowing gas containing about 0.1 to about 20% by volume fluorine is employed during the expansion stage of the blow molding operation.
Inventors
- 👤 Dale D Dixon
- 👤 Donald G Manly
- 👤 Gerald W Recktenwald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:19
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/46; B29C35/00; B29C35/16; B29C2035/1658; B29C2035/1675; B29C2035/1683; B29C2049/4602; B29C2049/4605; B29C2049/4608; B29C2049/4611; B29C2049/4614; B29C2049/4617; B29C2049/462; B29C2049/4623; B29K; B29K2023/00; B29K2023/04; B29K2023/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
53 words
The process of claim 1 wherein the fluid medium also containS a gas selected from the group consisting of 0.5 to about 20% by volume of sulfur dioxide or carbon monoxide, 0.5 to about 50% by volume of carbon dioxide, 0.5 to about 99% by volume of chlorine or bromine and mixtures thereof.
Claim 2
Dependent Claim
125 words
A process for producing a blow molded hollow thermoplastic article which comprises the steps of: a. heating a thermoplastic selected from the group consisting of polymers and copolymers of polystyrene, polyacrylonitrile, polyvinyl chloride, and polyolefins of at least one aliphatic mono-1-olefin having a maximum of 8 carbon atoms per molecule to a temperature at or above its softening point, b. forming a parison of said thermoplastic, c. expanding said parison within a closed mold to conform it to the contour of said mold by means of a reactive gas mixture comprising from about 0.1 to 10% by volume fluorine and the balance of an inert gas, d. removing the reactive gas mixture from the resulting article, and e. recovering said article having improved barrier properties.
Claim 3
Dependent Claim
54 words
The process of claim 3 wherein the reactive gas mixture also contains a gas selected from the group consisting of 0.5 to about 20% by volume of sulfur dioxide or carbon monoxide, 0.5 to about 50% by volume of carbon dioxide, 0.5 to about 99% by volume of chlorine or bromine and mixtures thereof.
Claim 4
Dependent Claim
29 words
The process of claim 3 wherein said reactive gas mixture comprises from about 1 to 10% by volume fluorine and 99 to 90% by volume nitrogen, argon or helium.
Claim 5
Dependent Claim
28 words
The process of claim 3 wherein said thermoplastic comprises a polymer or copolymer of at least one aliphatic mono-1-olefin having a maximum of 8 carbon atoms per molecule.
Claim 6
Dependent Claim
18 words
The process of claim 6 wherein said thermoplastic comprises essentially polyethylene having a density of 0.91 to 0.98.
Claim 7
Dependent Claim
24 words
The process of claim 3 wherein said reactive gas mixture is removed and the resulting article is cooled by purging with an inert gas.
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) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |