http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EA-000563-B1
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_e83d93ed02bbd6159e99b5a7796e3686 |
| classificationCPCAdditional | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08J2323-02 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08J2201-0542 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08J2201-0546 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08J2201-0543 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08J9-28 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C08J9-28 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/A61K9-00 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/A61K47-32 |
| filingDate | 1996-11-15-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_ddc17d7b49c0d9feeb4885359f16bd61 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_8dbe878ea365b9d74994836c5208d196 |
| publicationDate | 1999-10-28-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | EA-000563-B1 |
| titleOfInvention | METHOD FOR OBTAINING POROUS POLYOLEFIN PARTICLES |
| abstract | 1. Process for the preparation of porous polyolefin particles, which process comprises the following steps: dissolution of at least one crystallizable polyolefin in a solvent, which results in a solution being formed which comprises 0.1-50 wt.% (on the basis of the sum of the weight of the solvent and that of the polyolefin) polyolefin, and the initial polyolefin solution formed containing between 5 ppm and 20 wt.% (on the basis of the sum of the weight of the polyolefin and that of the nucleating agent) of nucleating agent, dispersion of the resulting polyolefin solution in a non-solvent, at a temperature that is higher than the crystallization temperature of the polyolefin in the polyolefin solution, upon which a multiphase system is formed, cooling of the multiphase system, with simultaneous stirring, the cooling rate being between 0.05 and 10 degree C/min, down to a temperature which is below the crystallization temperature of the polyolefin in the polyolefin solution, so that polyolefin-containing particles are formed, separation of the polyolefin-containing particles from the liquid(s), drying of the polyolefin-containing particles at a temperature that is below the crystallization temperature of the polyolefin in the initial polyolefin solution. 2. Process for the preparation of porous polyolefin particles, which process comprises the following steps: dissolution of at least one crystallizable functionalized polyolefin in a solvent, which results in a-solution being formed which comprises 0.1-50 wt.% (on the basis of the sum of the weight of the solvent and that of the functionalized polyolefin) functionalized polyolefin, dispersion of the resulting polyolefin solution in a non-solvent, at a temperature that is higher than the crystallization temperature of the functionalized-polyolefin in the polyolefin solution, upon which a multiphase system is formed, cooling of the multiphase system, with simultaneous stirring, the cooling rate being between 0.05 and 10 degree C/min, down to a temperature which is below the crystallization temperature of the functionalized-polyolefin in the polyolefin solution, so that functionalized-polyolefin-containing particles are formed, separation of the functionalized-polyolefin-containing particles from the liquid(s), drying of the functionalized-polyolefin-containing particles at a temperature that is below the crystallization temperature of the functionalized-polyolefin in the initial polyolefin solution. 3. Process according to either one of Claims 1-3, characterized in that, before the multiphase system is cooled, a portion of the solvent is evaporated from the multiphase system formed. 4. Process according to either one of Claim 1-3, characterized in that the polyolefin is a polyethylene. 5. Process according to Claim 4, characterized in that the solvent is cyclohexane, n-hexane or n-heptane. 6. Process according to any one of Claims 1-5, characterized in that the (functionalized) polyolefin concentration in the polyolefin solution is between 1 and 30 wt.% (on the basis of the sum of the weight of the solvent and that of the polyolefin). 7. Process according to any one of Claims 1 or 3-6, characterized in that the nucleating agent is chosen from the following compounds: silicates, mica, talc, sorbitol derivatives, saturated.or unsaturated fatty acids or their salts, organic pigments, polyolefins with functional groups, or a combination of these. 8. Process according to Claim 7, in which the nucleating agent is talc, a sorbitol derivative or an oxidized polyolefin. 9. Process according to any one of Claims 1-8, characterized in that the non-solvent is water, acetone, methanol, ethanol or a mixture of these compounds. 10. Process according to any one of Claims 1-9, characterized in that the non-solvent contains a surface-active agent. 11. Process according to any one of Claims 1-10, characterized in that the multiphase system is subjected to cooling at a rate that is between 0.1 and 5 degree C/min. 12. Process according to Claim 11, characterized in that the multiphase system is subjected to cooling at a rate that is between 0.2 and 2 degree C/min. 13. Process according to any one of Claims 1-12, characterized in that, upon drying under reduced pressure, the partial pressure of the solvent in the vapour phase is less than 20% of the standard vapour pressure of the solvent at 20 degree C. 14. Process according to Claim 2 and 7, in which the functionalized polyolefin contains from 0.1 to 15 wt.% functional groups. 15. Use of the porous polyolefin particles obtained according to the process of any one of Claims 1-14 as concentrate, absorbent or carrier for substances that are to be released slowly or in a controlled manner. |
| priorityDate | 1995-12-06-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
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