US3821182A
Expired / Lapsed
US
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Method for preparing of film of a vinylidene chloride polymer
Assignee: WR Grace and Co Conn
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Filing: 1971-02-11
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Granted: 1974-06-28
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Expires: 1991-02-11
Abstract
Abstract A vinylidene chloride polymer film, a method of producing a direct laminate of vinylidene chloride and a non-saran thermoplastic polymer, preferably polyethylene, including procedures for orienting and irradiating the laminate and the method above wherein the outer polymer layers are stripped from the saran to provide a saran film.
Inventors
- 👤 W Baird
- 👤 S Holbrook
- 👤 J Platt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:16
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10; B29C48/14; B29C48/147; B29C48/1472; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/32; B29C48/335; B29C48/336; B32B1/00; B32B1/08; B32B27/30; B32B27/304; B32B27/32; B29C2791/00; B29C2791/004; B29C2791/007; B29C48/001; B29C48/0017; B29C48/0018; B29C48/0019; B29K; B29K2027/00; B29L; B29L2009/00; B32B2323/00; B32B2323/04; B32B2327/00; B32B2327/06; B32B2597/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
24 words
The film of claim 1 wherein said film has been irradiated with high energy electrons to a dosage of 1 megarad to 75 megarads.
Claim 2
Dependent Claim
130 words
A biaxially oriented crystalline film made of a thermoplastic copolymer of vinylidene chloride and at least one copolymerizable monomer, wherein the vinylidene chloride is at least 50 percent of the material in the copolymer, said film having an average thickness of less than 0.3 mil and having a shrinkability at 96*C of 100 to 500 percent in the transverse direction and 100 to 700 percent in the longitudinal direction, said film having been made by coextruding said copolymer as a melt between outer plies of thermoplastic polymer melts through a die, cooling and stretching to orient so as to produce a copolymer film between the order plies which is substantially devoid of pinholes and scratches and has low oxygen permeability and thereafter separating said outer plies from said copolymer film.
Claim 3
Dependent Claim
29 words
The film of claim 3 wherein said film has been irradiated with high energy electrons to a dosage of 1 megarad to 75 megarads after cooling but before stretching.
Claim 4
Dependent Claim
32 words
The film of claim 3 wherein said film has a haze of less than 2 percent and an average shrink of more than 30 percent in both the transverse and longitudinal directions.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |