US4254207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing spherical particles or crystalline polymers
Assignee: Hercules LLC
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Filing: 1979-12-26
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Granted: 1981-03-03
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Expires: 1999-12-26
Abstract
Abstract A process for producing uniformly small spherical particles of crystalline, normally solid condensation polymers is described. The process of this invention further provides high yields of hydrophobic, non-agglomerating particles in a useful size range directly, without the need for subsequent processing, and is carried out by forming a dispersion of small liquid particles of the crystalline polymer in certain aprotic liquids containing 0.1 to 20% by weight of the polymer of an acid-modified polymer of propylene in a specified manner, cooling the dispersion with agitation until the liquid particles solidify and recovering the particles.
Inventors
- 👤 Leo M. Landoll
- 👤 Walter S. Ropp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:09
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/16; C08J3/02; C08J3/09; C08J3/11
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
114 words
A process for producing spherical small particles of crystalline, normally solid condensation-type polymers which process comprises agitating under conditions of shear a fluid mixture of said polymer in an aprotic liquid which is a non-solvent for said polymer and which contains dissolved or dispersed therein from 0.1 to 20%, based on the weight of said polymer, of an acid-modified polymer of propylene at a temperature above the crystalline melting point of the condensation-type polymer until a dispersion of small liquid particles is formed, agitating the dispersion while cooling to a temperature below the crystalline melting point of the condensation-type polymer until the liquid particles solidify, and recovering the resulting particles from the aprotic liquid.
Claim 2
Dependent Claim
114 words
A process for producing spherical small particles of crystalline, normally solid condensation-type polymers which process comprises agitating under conditions of shear a fluid mixture of said polymer in an aprotic liquid which is a non-solvent for said polymer and which contains dissolved or dispersed therein from 0.1 to 20%, based on the weight of said polymer, of an acid-modified polymer of propylene at a temperature above the crystalline melting point of the condensation-type polymer until a dispersion of small liquid particles is formed, agitating the dispersion while cooling to a temperature below the crystalline melting point of the condensation-type polymer until the liquid particles solidify, and recovering the resulting particles from the aprotic liquid.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the crystalline condensation-type polymer is a polyester.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein the polyester is an aliphatic polyester.
Claim 5
Dependent Claim
10 words
The process of claim 3 wherein the polyester is pigmented.
Claim 6
Dependent Claim
12 words
The process of claim 4 in which the pigment is carbon black.
Claim 7
Dependent Claim
13 words
The process of claim 4 in which the pigment is magnetic iron oxide.
Claim 8
Dependent Claim
14 words
The process of claim 4 wherein the acid modified polymer of propylene is amorphous.
Claim 9
Dependent Claim
26 words
The process of claim 7 wherein the carboxyl content of the acid-modified polymer of propylene ranges from 0.15 to 10% by weight of the modified polymer.
Claim 10
Dependent Claim
15 words
The process of claim 8 wherein the acid-modified polymer of propylene is maleic anhydride-modified polypropylene.
Claim 11
Dependent Claim
11 words
The process of claim 9 wherein the polyester is poly(butylene adipate).
Claim 12
Dependent Claim
15 words
The process of claim 8 wherein the acid-modified polymer of propylene is acrylic acid-modified polypropylene.
Claim 13
Dependent Claim
11 words
The process of claim 11 wherein the polyester is poly(butylene adipate).
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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |