Reverse-phase polymerization process

Patent metadata

Field	Value
Publication number	US-10370461-B2
Application number	US-201414908872-A
Country	US
Kind code	B2
Filing date	Jul 29, 2014
Priority date	Jul 31, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A reverse-phase suspension polymerization process for the manufacture of polymer beads comprising forming aqueous monomer beads comprising an aqueous solution of water-soluble ethylenically unsaturated monomer or monomer blend and polymerizing the monomer or monomer blend, to form polymer beads while suspended in a non-aqueous liquid, and recovering polymer beads, in which the process comprises providing in a vessel (1) a volume (2) of non-aqueous liquid wherein the volume of non-aqueous liquid extends between at least one polymer bead discharge point (3) and at least one monomer feed point (4), feeding the aqueous monomer or monomer blend through orifices (5) into, or onto, the non-aqueous liquid to form aqueous monomer beads, allowing the aqueous monomer beads to flow towards the polymer bead discharge point initiating polymerization of the aqueous monomer beads to form polymerizing beads, wherein the polymerizing beads form polymer beads when they reach the polymer bead discharge point, removing a suspension of the polymer beads in non-aqueous liquid from the vessel at the polymer bead discharge point and recovering, water soluble or water swellable polymer beads from the suspension, in which the aqueous monomer or monomer blend and/or the orifices is/are vibrated such that the frequency multiplied by the weight average droplet diameter is between 150 and 800 mm/s. The invention also relates to the apparatus suitable for carrying out a reverse-phase suspension polymerization and polymer beads obtainable by the process or employing the apparatus. Furthermore, the invention also relates to polymer beads having a weight mean particle size in the range of 0.05 to 5 mm which are held in a container in an amount of at least 300 kg having a standard deviation of particle size less than 20%. In addition, the invention also provides polymer beads having a weight mean particle size in the range 0.05 to 5 mm having a standard deviation of particle size less than 20% and having an amount of residual acrylamide of less than 500 ppm.

First claim

The invention claimed is:

1. A reverse-phase suspension polymerisation process for the manufacture of polymer beads comprising forming aqueous monomer beads of an aqueous solution comprising water-soluble ethylenically unsaturated monomer or monomer blend and polymerising the monomer or monomer blend, to form polymer beads while suspended in a non-aqueous liquid, and recovering polymer beads, in which the process comprises:
providing in a vessel a volume of non-aqueous liquid wherein the volume of non-aqueous liquid extends between at least one polymer bead discharge point and at least one monomer feed point,
feeding the aqueous monomer or monomer blend through orifices into, or onto, the non-aqueous liquid to form aqueous monomer beads,
allowing the aqueous monomer beads to flow towards the polymer bead discharge point initiating polymerisation of the aqueous monomer beads to form polymerising beads,
wherein the polymerising beads have formed polymer beads when they reach the polymer bead discharge point,
removing a suspension of the polymer beads in non-aqueous liquid from the vessel at the polymer bead discharge point and recovering, water soluble or water swellable polymer beads from the suspension, in which the aqueous monomer or monomer blend and/or the orifices is/are vibrated such that the frequency multiplied by the weight average droplet diameter is between 150 and 800 mm/s,
wherein the non-aqueous liquid flows in a downward direction and co-current with the direction of flow of the monomer beads.

2. The process according to claim 1 in which the polymer beads removed from the vessel at the polymer bead discharge point are subjected to a post polymerisation stage.

3. The process according to claim 1 in which the aqueous monomer or monomer blend and/or the orifices is/are vibrated such that the frequency multiplied by the weight average droplet diameter is between 250 and 500 mm/s.

4. The process according to claim 1 in which the vibration amplitude is between 0.0005 and 0.5 mm.

5. The process according to claim 1 in which the orifices are disposed in at least one plate or at least one grid.

6. The process according to claim 1 in which the orifices comprise a conical part and a cylindrical part.

7. The process according to claim 6 in which the aqueous monomer or monomer blend flows through the conical part and then through the cylindrical part.

8. The process according to claim 1 wherein the process is conducted in two or more vessels in parallel.

9. The process according to claim 1 in which the aqueous monomer or monomer blend and/or the non-aqueous liquid contains a polymerisation initiator.

10. The process according to claim 1 in which the suspension of the polymer beads in the non-aqueous liquid removed at the polymer bead discharge point has a concentration of at least 10% polymer beads on total weight of suspension.

11. The process according to claim 1 in which the aqueous polymer beads are produced at a rate of at least 15 kg/hour.

12. The process according to claim 1 in which an amphipathic stabiliser is included in the non-aqueous liquid.

13. The process according to claim 1 wherein the water-soluble ethylenically unsaturated monomer or monomer blend comprises at least one monomer selected from the group consisting of acrylamide, methacrylamide, N-vinyl pyrrolidone, 2-hydroxy ethyl acrylate, acrylic acid (or salts thereof), methacrylic acid (or salts thereof), itaconic acid (or salts thereof), maleic acid (or salts thereof), 2-acrylamido-2-propane sulphonic acid (or salts thereof), vinyl sulphonic acid (or salts thereof), allyl sulphonic acid (or salts thereof), dimethyl amino ethyl acrylate (or acid salts or quaternary ammonium salts thereof), dimethyl amino ethyl methacrylate (or acid salts or quaternary ammonium salts thereof), dimethyl amino propyl acrylamide (or acid salts or quaternary ammonium salts thereof), dimethyl amino propyl methacrylamide (or acid salts or quaternary ammonium salts thereof), vinyl formamide and combinations of any of the above.

14. The process according to claim 13 in which at least one monomer has been prepared by a chemically catalysed process, a biologically catalysed process or a biological process.

15. The process according to claim 13 in which the acrylamide has been prepared by a biological catalysed process or a biological process.

16. The process according to claim 1 in which the so formed polymer beads are ground to produce a polymer powder.

17. The process according to claim 1 in which the process is performed in a continuous mode.

Assignees

• Basf Se

Inventors

• Hesse Pascal
• Jelicic Aleksandra
• Fonseca Zepeda Gabriela Eugenia
• Haschick Robert
• Keelapandal Ramamoorthy Shankara Narayanan
• Naylor Gareth Ian
• Barratt John Scott
• Soetje Oliver
• Lievre Marcel
• Rainau Florian
• Lebkuecher Mark

Classifications

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C08F220/20

  of polyhydric alcohols or phenols {, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate} · CPC title

• B01J19/123

  Ultraviolet light · CPC title

• B01J2219/0869

  Feeding or evacuating the reactor · CPC title

• B01J4/02

  for feeding measured {, i.e. prescribed} quantities of reagents · CPC title