Patent US4446208A successfully refreshed from Google Patents.
US4446208A
Expired / Lapsed
US
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Expandable polystyrene composition and process
Assignee: Cosden Technology Inc
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Filing: 1983-07-22
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Granted: 1984-05-01
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Expires: 2003-07-22
Abstract
Abstract A composition and process for reducing the adhesion of expandable polystyrene beads impregnated with a blowing agent such as pentane. The composition comprises effective amounts of magnesium stearate and zinc stearate respectively. The composition is added to the polystyrene in an apparatus such as a tumble blender prior to pre-expansion of the impregnated polystyrene beads.
Inventors
- 👤 Richard A. Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:07
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/22; C08J9/224; C08J2325/00; C08J2325/02; C08J2325/04; C08J2325/06; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
84 words
Expandable polystyrene beads exhibiting reduced adhesion to one another comprising expandable polystyrene beads containing a volatile blowing agent, said beads being coated with an anti-adhesion composition comprising effective amounts of magnesium stearate and zinc stearate respectively, wherein, (a) the effective amount of magnesium stearate is from about 50 gms. to about 40 gms. per 1,000 lbs. of expandable polystyrene beads; and (b) the effective amount of zinc stearate is from about 50 gms. to about 500 gms. per 1,000 lbs. of expandable polystyrene beads.
Claim 2
Dependent Claim
84 words
Expandable polystyrene beads exhibiting reduced adhesion to one another comprising expandable polystyrene beads containing a volatile blowing agent, said beads being coated with an anti-adhesion composition comprising effective amounts of magnesium stearate and zinc stearate respectively, wherein, (a) the effective amount of magnesium stearate is from about 50 gms. to about 40 gms. per 1,000 lbs. of expandable polystyrene beads; and (b) the effective amount of zinc stearate is from about 50 gms. to about 500 gms. per 1,000 lbs. of expandable polystyrene beads.
Claim 3
Dependent Claim
11 words
The composition of claim 1 wherein the blowing agent is pentane.
References Cited (Backward Citations)
US3560414A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-01 | 1987-10-31 | 1988-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-01 | 1991-10-31 | 1992-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-01 | 1995-10-31 | 1996-05-01 | $7700.00 | Window Closed / Lapsed |