# US 10,370,461 B2 · Reverse-phase polymerization process

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- Number: US 10,370,461 B2
- Document ID: US10370461B2
- Status: Granted
- Kind: B2
- Application number: 14/908,872
- Filed: 2014-07-29
- Published: 2016-06-09
- Granted: 2019-08-06
- Earliest claimed: 2013-07-31
- Assignees: BASF SE
- Applicants: BASF SE
- Inventors: Pascal Hesse; Aleksandra Jelicic; Gabriela Eugenia Fonseca Zepeda; Robert Haschick; Shankara Narayanan Keelapandal Ramamoorthy; Gareth Ian Naylor; John Scott Barratt; Oliver Soetje; Marcel Lievre; Florian Rainau; Mark Lebkuecher
- Web page: https://patentgrep.com/patent/US10370461B2

## CPC

- C08F 2/32: Polymerisation in water-in-oil emulsions
- B01J 4/002: {Nozzle-type elements (nozzle-type reactors B01J19/26)}
- B01J 4/004: {Sparger-type elements}
- B01J 4/007: {provided with moving parts}
- B01J 4/02: for feeding measured {, i.e. prescribed} quantities of reagents
- B01J 19/10: employing sonic or ultrasonic vibrations
- B01J 19/123: {Ultraviolet light}
- C08F 2/01: characterised by special features of the polymerisation apparatus used
- C08F 220/56: Acrylamide; Methacrylamide
- B01J 2219/0869: Feeding or evacuating the reactor
- B01J 2219/0888: Liquid-liquid
- B01J 2219/24: Stationary reactors without moving elements inside
- C08F 220/06: Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
- C08F 220/20: of polyhydric alcohols or phenols {, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate}
- C08F 220/382: {and containing oxygen, e.g. 2-sulfoethyl (meth)acrylate}
- C08F 220/385: {and containing nitrogen}
- C08F 226/10: N-Vinyl-pyrrolidone
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## 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.

## Claims

### Claim 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 1)

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

### Claim 5 (depends on 1)

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

### Claim 6 (depends on 1)

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

### Claim 7 (depends on 6)

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.

### Claim 8 (depends on 1)

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

### Claim 9 (depends on 1)

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

### Claim 10 (depends on 1)

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.

### Claim 11 (depends on 1)

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

### Claim 12 (depends on 1)

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

### Claim 13 (depends on 1)

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.

### Claim 14 (depends on 13)

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.

### Claim 15 (depends on 13)

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

### Claim 16 (depends on 1)

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

### Claim 17 (depends on 1)

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