Patent US3942903A successfully refreshed from Google Patents.
US3942903A
Expired / Lapsed
US
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Unitary porous themoplastic writing nib
Assignee: Porex Technologies Corp
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Filing: 1974-04-23
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Granted: 1976-03-09
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Expires: 1994-04-23
Abstract
Abstract A process is provided to form spherical thermoplastic particles that involves dispersing a thermoplastic powder in a liquid that is a partial solvent for the thermoplastic, breaking the dispersion into droplets, forming thermoplastic spheres by heating the droplets to a temperature sufficient to at least partially solubilize the thermoplastic and to evaporate the solvent. Unique products, including porous structures, may be produced from material formed by this process.
Inventors
- 👤 Clarence A. Dickey
- 👤 John E. McDaniel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:12
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/24; B; B43; B43K; B43K1/00; B43K1/006; C08J3/00; C08J3/12; C08J3/122; Y; Y10; Y10S; Y10S521/00; Y10S521/919; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
70 words
A unitary porous thermoplastic polymer product formed by: dispersing thermoplastic polymer particles in a partial solvent for said thermoplastic polymer; atomizing the dispersion at an elevated temperature sufficient to at least partially solubilize said thermoplastic polymer, to vaporize said partial solvent and to cause said particles to adhere and melt together thus forming fully-densified microspheres of the thermoplastic polymer; and sintering said thermoplastic polymer microspheres to form the porous product.
Claim 2
Dependent Claim
70 words
A unitary porous thermoplastic polymer product formed by: dispersing thermoplastic polymer particles in a partial solvent for said thermoplastic polymer; atomizing the dispersion at an elevated temperature sufficient to at least partially solubilize said thermoplastic polymer, to vaporize said partial solvent and to cause said particles to adhere and melt together thus forming fully-densified microspheres of the thermoplastic polymer; and sintering said thermoplastic polymer microspheres to form the porous product.
Claim 3
Dependent Claim
18 words
A unitary porous product of claim 1 formed of a plurality of fully-densified polyvinylidene fluoride microspheres sintered together.
Claim 4
Dependent Claim
10 words
A writing nib formed from the product of claim 2.
Claim 5
Dependent Claim
10 words
A writing nib formed from the product of claim 1.
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) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |