PROCESS FOR PREPARING COPOLYMERS OBTAINED BY GRAFT POLYMERIZATION IN SOLUTION AND BASED ON POLYETHERS IN SOLID FORM

• US 20100204425A1
• Filed: 07/16/2008
• Published: 08/12/2010
• Est. Priority Date: 07/26/2007
• Status: Abandoned Application

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Güntherberg, Norbert, Dobrawa, Rainer, Meyer-Böhm, Kathrin, Mertoglu, Murat
• Application Number:
  US12/670,680
• Publication Number:
  US 20100204425A1
• Time in Patent Office: Days
• US Class Current: 526/264
• CPC Class Codes: B29C 48/03 characterised by the shape of the extruded material at extrusion
• CPC Class Codes: B29C 48/405 Intermeshing co-rotating screws
• CPC Class Codes: B29C 48/41 Intermeshing counter-rotating screws
• CPC Class Codes: B29C 48/76 Venting , drying means; Degassing means
• CPC Class Codes: C08F 283/06 on to polyethers, polyoxymethylenes or polyacetals C08F283/004 takes precedence

Abstract

A process for preparing copolymers in solid form, where the copolymers are obtained by free-radical polymerization of a mixture of 30 to 80% by weight of N-vinyllactam, 10 to 50% by weight of vinyl acetate and 10 to 50% by weight of a polyether in the presence of at least one solvent, with the proviso that the total of i), ii) and iii) equals 100% by weight, which process comprises removing the solvent from the polymerization mixture with the aid of an extruder.

Claims

1-5. -5. (canceled)

6. A process for preparing copolymers in solid form, where the copolymers are obtained by free-radical polymerization of a mixture of

(i) 30 to 80% by weight of N-vinyllactam,

(ii) 10 to 50% by weight of vinyl acetate and

(iii) 10 to 50% by weight of a polyether in the presence of at least one solvent,

with the proviso that the total of i), ii) and iii) equals 100% by weight, wherein the process comprises removing the solvent from the polymerization mixture with the aid of an extruder.

7. The process according to claim 6, wherein the polymerization solution is mixed with a slightly water-soluble active substance before removal of the solvent.

8. The process according to claim 6, wherein a slightly water-soluble active substance is introduced into the extruder during removal of the solvents.

9. The process according to claim 6, wherein the copolymers are molten during the removal of the solvent in the extruder.

10. The process according to claim 6, wherein the removal of the solvent takes place at temperatures of from 100 to 220°

C.

11. The process according to claim 6, wherein the mixture is

(i) 40 to 60% by weight of N-vinyllactam,

(ii) 15 to 35% by weight of vinyl acetate and

(iii) 10 to 30% by weight of a polyether.

12. The process according to claim 6, wherein the mixture is

(i) 50 to 60% by weight of N-vinyllactam,

(ii) 25 to 35% by weight of vinyl acetate and

(iii) 10 to 20% by weight of a polyether.