Patent US3791916A successfully refreshed from Google Patents.
US3791916A
Expired / Lapsed
US
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Sealing polystyrene
Assignee: WR Grace and Co Conn
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Filing: 1971-12-06
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Granted: 1974-02-12
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Expires: 1991-12-06
Abstract
Abstract Two polystyrene surfaces may be sealed together with a fusion type seal at a temperature below the melting point or distortion temperatures of the polystyrene by coating the polystyrene with a selected material that causes the polystyrene to seal in such a manner at a temperature between room temperature and the melting temperature of the polystyrene. A new article is formed having two layers of polystyrene separated by a layer of polystyrene with a selected material dispersed therein. In some species the medial layer is stronger than the adjacent polystyrene layers and in others, the seals will open along the seal line when opening stress is applied to the article.
Inventors
- 👤 F Eastes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:04
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; C; C08; C08J; C08J5/00; C08J5/12; B32B27/30; B32B27/302; C08J5/122; B32B2325/00; C08J2325/00; C08J2325/02; C08J2325/04; C08J2325/06; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31938
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
32 words
The article of claim 1 wherein said material is selected from the group consisting of acetyltri-2-ethylhexyl citrate, glyceryl triacetate, propylene glycol monolaurate, polyethylene glycol dilaurate, fully acetylated acetoglyceride (C14-C20) and mixtures thereof.
Claim 2
Dependent Claim
22 words
The article of claim 1 wherein the fused surfaces have greater strength integrity than adjacent unfused portions of the two polystyrene surfaces.
Claim 3
Dependent Claim
22 words
The article of claim 1 comprising two juxtapositioned layers comprising polystyrene separated by a layer of polystyrene having the material dispersed therein.
Claim 4
Dependent Claim
42 words
An article comprising polystyrene having a surface thereof coated with a material selected from the group consisting of citric acid triester, glyceryl triester, propylene glycol fatty acid monoester, polyethylene glycol fatty acid diester, more than 60 percent acetylated acetoglyceride and mixtures thereof.
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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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |