Patent US4430450A successfully refreshed from Google Patents.
US4430450A
Expired / Lapsed
US
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Expandable thermoplastic polymer particles and process for producing the same
Assignee: Kanegafuchi Chemical Industry Co Ltd
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Filing: 1983-05-27
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Granted: 1984-02-07
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Expires: 2003-05-27
Abstract
Abstract Disclosed are expandable thermoplastic polymer particles and process for preparing the same. Expandable thermoplastic polymer particles superior in processability as well as expansion are prepared by controlling an amount of inside moisture contained in said particles coated or impregnated with a blowing agent to not more than 1% by weight based on polymer, immediately after prepared.
Inventors
- 👤 Kenichi Senda
- 👤 Masao Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:29
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
111 words
In a process for producing expandable thermoplastic polymer particles, improvement which comprises pelletizing styrene polymer powder obtained by emulsion polymerization and coating or impregnating the resulting pellets with a volatile blowing agent in an aqueous suspension medium containing a suspending agent and a water-soluble inorganic salt selected from the group consisting of calcium chloride, sodium sulfate, magnesium chloride, sodium chloride and mixtures thereof, in a range of from 3 to 20 parts by weight based on 100 parts by weight of the aqueous suspension medium, whereby the amount of inside moisture contained in said particles immediately after preparation is not more than 1% based on the weight of the polymer particle.
Claim 2
Dependent Claim
111 words
In a process for producing expandable thermoplastic polymer particles, improvement which comprises pelletizing styrene polymer powder obtained by emulsion polymerization and coating or impregnating the resulting pellets with a volatile blowing agent in an aqueous suspension medium containing a suspending agent and a water-soluble inorganic salt selected from the group consisting of calcium chloride, sodium sulfate, magnesium chloride, sodium chloride and mixtures thereof, in a range of from 3 to 20 parts by weight based on 100 parts by weight of the aqueous suspension medium, whereby the amount of inside moisture contained in said particles immediately after preparation is not more than 1% based on the weight of the polymer particle.
References Cited (Backward Citations)
US4017427A
Cited
US4036794A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |