US4332749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of polyolefine-based fibrids, and the fibrids obtained
Assignee: Hercules LLC
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Filing: 1980-04-23
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Granted: 1982-06-01
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Expires: 2000-04-23
Abstract
Abstract Polyolefine-based fibrids are produced by the abrupt expansion of a liquid mixture of molten polyolefine and solvent, this mixture being at high temperature and high pressure. The mixture contains the solvent, a polyolefine of normal molecular weight and a polyolefine of low molecular weight onto which a polar monomer has been grafted. The fibrids obtained possess a high proportion of grafted polyolefine on their surface.
Inventors
- 👤 Jean-Pierre Pleska
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:14
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/11
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
97 words
In a process for the production of polyolefine-based fibrids by the abrupt expansion of a liquid mixture of molten polyolefine and solvent, by passage through an orifice, the mixture being under pressure and temperature conditions which are such that the abrupt expansion causes the instantaneous vaporisation of the solvent and the solidification of the polyolefine in the form of fibrids, the improvement comprising subjecting to abrupt expansion a liquid mixture containing (1) a polyolefine of normal molecular weight, (2) said solvent and (3) a polyolefine of low molecular weight, onto which a polar monomer has been grafted.
Claim 2
Dependent Claim
97 words
In a process for the production of polyolefine-based fibrids by the abrupt expansion of a liquid mixture of molten polyolefine and solvent, by passage through an orifice, the mixture being under pressure and temperature conditions which are such that the abrupt expansion causes the instantaneous vaporisation of the solvent and the solidification of the polyolefine in the form of fibrids, the improvement comprising subjecting to abrupt expansion a liquid mixture containing (1) a polyolefine of normal molecular weight, (2) said solvent and (3) a polyolefine of low molecular weight, onto which a polar monomer has been grafted.
Claim 3
Dependent Claim
21 words
Process according to claim 1, wherein the polyolefine of low molecular weight is an olefine polymer derived from ethylene and propylene.
Claim 4
Dependent Claim
23 words
Process according to claim 1 or 2, wherein the polyolefine of low molecular weight has a number-average molecular weight of less than 8,000.
Claim 5
Dependent Claim
23 words
Process according to claim 1 or 2, wherein the polyolefine of low molecular weight is a crystalline polyethylene wax or crystalline polypropylene wax.
Claim 6
Dependent Claim
14 words
Process according to claim 1 or 2, wherein said polar monomer comprises maleic anhydride.
Claim 7
Dependent Claim
28 words
Process according to claim 1 or 2, wherein the proportion of polar monomer in the grafted polyolefine of low molecular weight is between 0.1 and 5% by weight.
Claim 8
Dependent Claim
37 words
Process according to claim 1 or 2, wherein the amount of grafted polyolefine of low molecular weight in the liquid mixture is between 5 and 40% of the total weight of the polyolefines present in the mixture.
Claim 9
Dependent Claim
22 words
Process according to claim 1 or 2, wherein a polar monomer has not been grafted onto the polyolefine of normal molecular weight.
Claim 10
Dependent Claim
46 words
Process according to claim 1 or 2, wherein the grafted polyolefine of low molecular weight is manufactured by malaxating a mixture comprising the polyolefine of low molecular weight and the polar monomer at a temperature above the melting point of the polyolefine of low molecular weight.
Claim 11
Dependent Claim
16 words
Process according to claim 9, wherein the mixture which is malaxated additionally comprises a free-radical generator.
Claim 12
Dependent Claim
36 words
Process according to claim 10, wherein the polyolefine of normal molecular weight has a number-average molecular weight greater than 15,000 and the polyolefine of low molecular weight has a number-average molecular weight of less than 5,000.
Claim 13
Dependent Claim
44 words
Process according to claim 1 or 2, wherein the polyolefine of low molecular weight has a number-average molecular weight of less than 8,000 and the proportion of polar monomer in the grafted polyolefine of low molecular weight in between 0.1 and 5% by weight.
Claim 14
Dependent Claim
12 words
Process according to claim 12, wherein said polar monomer comprises maleic anhydride.
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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) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |