POLYMERIZATION AND ISOLATION OF LOW VISCOSITY POLYMERS USING PASTILLATION TECHNOLOGY

• US 20200131282A1
• Filed: 07/02/2018
• Published: 04/30/2020
• Est. Priority Date: 07/14/2017
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Zogg, JR., Michael J., Bawiskar, Santosh S., Jin, Yi, Rynearson, Daniel S., Boone, Harold W., Brown, Kate R., Kluge, JR., Barry D.
• Granted Patent: US 11,059,913 B2
• Time in Patent Office: Days
• CPC Class Codes: B29B 9/10 by moulding the material, i.e. treating it in the molten state
• CPC Class Codes: C08F 10/02 Ethene
• CPC Class Codes: C08F 10/06 Propene
• CPC Class Codes: C08F 2/01 characterised by special features of the polymerisation apparatus used
• CPC Class Codes: C08F 2/04 Polymerisation in solution C08F2/32 takes precedence
• CPC Class Codes: C08F 2400/02 Control or adjustment of polymerization parameters

Abstract

A process to form an olefin-based polymer, said process comprising at least the following steps: a) polymerizing a reaction mixture comprising an olefin, in at least one reactor, in a solution polymerization, to form a polymer solution; b) feeding at least a portion of the polymer solution through at least one devolatilizer, to form the olefin-based polymer, in melt form; c) feeding at least a portion of the olefin-based polymer, in melt, form through a heat exchanger, and then into a pastillation apparatus to form polymer particles.

Claims

1. A process to form an olefin-based polymer, said process comprising at least the following steps:

a) polymerizing a reaction mixture comprising an olefin, in at least one reactor, in a solution polymerization, to form a polymer solution;

b) feeding at least a portion of the polymer solution through at least one devolatilizer, to form the olefin-based polymer, in melt form;

c) feeding at least a portion of the olefin-based polymer, in melt, form through a heat exchanger, and then into a pastillation apparatus to form polymer particles.

2. The process of claim 1, wherein the process is a continuous process.

3. The process of claim 1, wherein, for step c, the pastillation apparatus comprises a droplet former, and wherein the olefin-based polymer, in melt form, comes into contact with, and is discharged through, the droplet former and cooled on a belt.

4. The process of claim 3, where the viscosity (η

(in cP)) of the olefin-based polymer at the temperature of the olefin-based polymer at the droplet former (T, °

C.) meets the following relationship;

ln(η

)≤

[0.028T−

b(T−

T₀)+2.96],

where the coefficient b indicates the temperature sensitivity of the viscosity of the olefin-based polymer;

T₀ is a reference temperature (177°

C.), and T>

T_m+20°

C. where T_m is the melting point of the olefin based polymer; and

T is the temperature of the olefin-based polymer at the droplet former; and

where η

=η

₀e<sup>−

b(T−

T0)</sup>, where η

₀ is the viscosity (cP) of the olefin-based polymer at 177°

C.

5. The process of claim 1, wherein the olefin-based polymer has a melt viscosity (177°

C.) from 500 to 10000 cP.

6. The process of claim 1, wherein a heat exchanger is located upstream from the pastillation apparatus.

7. The process of claim 1, wherein the olefin based polymer has a number average molecular weight from 4000 g/mol to 25,000 g/mol and a MWD<

3.5.

8. The process of claim 1, wherein the olefin-based polymer has a molecular weight distribution (MWD) from 1.80 to 3.50.

9. The process of claim 1, wherein the olefin-based polymer is a propylene-based polymer.

10. The process of claim 1, wherein the olefin-based polymer is an ethylene-based polymer.