PREPARATION OF POLYMER SEED HAVING STORAGE STABILITY

• Main Authors: HINDERER JUERGEN, HALLE OLAF DR, STRUEVER WERNER DR
• Format: Patent
• Language: English
• Published: 29.02.2000
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

PROBLEM TO BE SOLVED: To provide storage-stable polymer particles obtd. through polymerization of gelatin-sealed monomer droplets in an aq. phase, by conducting, immediately after the polymerization, drying of the gelatin-sealed seed until the residual water content comes to be less than a specific value. SOLUTION: This drying is conducted using a conventional dryer for attaining a residual water content of <1% in the polymer. It is pref. conducted in a fluidized bed type dryer, a tumbler dryer, a moving bed type dryer or a dryer cabinet. The drying conditions can be varied in a wide range. The drying is, e.g. pref. conducted under atmospheric pressure or a reduced pressure. A temp. of 25 deg.C is sufficient under a reduced pressure. Under normal pressure, the drying is pref. conducted at 40-120 deg.C. In the course of drying, the temp. of moist polymer particles is kept low at the beginning and approaches the drying temp. only when the residual moist content becomes low. The polymer thus prepd. can be employed as a seed for the seeding process and is stable in storage.