Process for the manufacture of flame retardant polycarbonate particles and flame retardant polycarbonate particles prepared thereby

Patent metadata

Field	Value
Publication number	US-10913827-B2
Application number	US-201816629115-A
Country	US
Kind code	B2
Filing date	Sep 7, 2018
Priority date	Sep 22, 2017
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A process for the manufacture of polycarbonate particles is disclosed herein. The process includes combining a first solution including a polycarbonate and a phosphorus-containing flame retardant or a flame retardant polycarbonate, and an organic solvent with a second solution including a surfactant and an aqueous solvent substantially immiscible with the organic solvent, under conditions of shear and temperature effective to provide an emulsion. At least a portion of the organic solvent is removed from the emulsion to provide an aqueous slurry having a plurality of particles, wherein the particles include the polycarbonate and the phosphorus-containing flame retardant or the flame retardant polycarbonate.

First claim

What is claimed is:

1. A process for the manufacture of polycarbonate particles, the process comprising:
combining a first solution comprising
(i) a polycarbonate and a phosphorus-containing flame retardant, and
(ii) an organic solvent

with a second solution comprising
(i) a surfactant and
(ii) an aqueous solvent substantially immiscible with the organic solvent, under conditions of shear and temperature effective to provide an emulsion; and

removing at least a portion of the organic solvent to provide an aqueous slurry comprising a plurality of particles comprising the polycarbonate and the phosphorus-containing flame retardant.

2. The process of claim 1 , wherein
the polycarbonate is a homopolycarbonate, a copolycarbonate, a polycarbonate copolymer, or a combination comprising at least one of the foregoing.

3. The process of claim 1 , wherein the first solution comprises 10 to 30 weight percent of the polycarbonate, based on the total weight of the polycarbonate and the organic solvent.

4. The process of claim 1 , wherein the phosphorus-containing flame retardant comprises an aromatic group, a phosphorus-nitrogen bond, or a combination comprising at least one of the foregoing.

5. The process of claim 1 , wherein the phosphorus-containing flame retardant is present in the first solution in an amount effective to provide 0.05 to 5 weight percent of phosphorus, based on the combined weight of the polycarbonate and the phosphorus-containing flame retardant.

6. The process of claim 1 , wherein a boiling point of the organic solvent is less than 100° C., and wherein the organic solvent is substantially immiscible with water.

7. The process of claim 1 , wherein the surfactant comprises an anionic surfactant, a biopolymer surfactant, or a combination comprising at least one of the foregoing,
wherein the anionic surfactant is a (C 8-36 alkyl)benzene sulfonate, (C 8-36 alkyl) sulfonate, mono- or di(C 8-36 alkyl) sulfosuccinate, (C 8-36 alkyl ether) sulfate, (C 8-36 )alkyl ether sulfonate, perfluoro(C 2-12 alkyl) sulfate, or perfluoro(C 2-12 carboxylate); and
wherein the biopolymer is gelatin.

8. The process of claim 1 , wherein
a weight ratio of the polycarbonate to the phosphorus-containing flame retardant is 99:1 to 50:50;
the emulsion comprises water in a water to organic solvent weight ratio of greater than or equal to 0.4:1 to 1.25:1; and
the emulsion comprises the surfactant in a surfactant to polycarbonate weight ratio of 0.008:1 to 0.04:1.

9. The process of claim 1 , wherein removing at least a portion of the organic solvent comprises exposing the emulsion to heat by adding the emulsion into a receiving water, wherein the receiving water is at a temperature of 25 to 90° C.

10. The process of claim 1 , wherein removing at least a portion of the organic solvent comprises exposing the emulsion to heat by heating the emulsion to a temperature of 25 to 90° C. to provide the slurry.

11. The process of claim 10 , wherein the heating is conducted until 70% to 95% of the organic solvent is removed to provide the slurry; and the method further comprises agitating the slurry without heating to remove the remaining organic solvent.

12. The process of claim 1 , wherein removing at least a portion of the organic solvent comprises purging the emulsion with air, nitrogen, argon, or a combination comprising at least one of the foregoing in the absence of heat.

13. The process of claim 1 , further comprising passing the aqueous slurry comprising the plurality of particles through a filter, to provide micronized particles having at least one of:
a Dv90 of 5 to 140 micrometers;
a Dv50 of 3 to 60 micrometers;
a Dv10 of 0.1 to 20 micrometers; or
a particle size distribution span of 1.05 to 3.5;
wherein Dv90, Dv50, Dv10 and particle size distribution span are determined by laser diffraction.

14. The process of claim 1 , wherein the polycarbonate particles are recovered in a yield greater than 25%.

15. The process of claim 1 , wherein the polycarbonate particles have a glass transition temperature of less than or equal to 140° C., determined using differential scanning calorimetry.

16. The process of claim 7 , wherein the polycarbonate particles have a residual gelatin content of less than 1000 parts per million.

17. The process of claim 1 , wherein the polycarbonate particles retain greater than 90% of the phosphorus-containing flame retardant present in the first solution.

18. Polycarbonate particles comprising a phosphorus-containing flame retardant, produced by the process of claim 1 ;
wherein the polycarbonate particles have at least one of:
a Dv90 of 5 to 140 micrometers;
a Dv50 of 3 to 60 micrometers;
a Dv10 of 0.1 to 20 micrometers; or
a particle size distribution span of 1.05 to 3.5; and
wherein Dv90, Dv50, Dv10 and particle size distribution span are determined by laser diffraction.

19. Polycarbonate particles comprising:
a polycarbonate and resorcinol bis (diphenyl phosphate);
wherein the polycarbonate particles have at least one of:
a Dv90 of 5 to 140 micrometers;
a Dv50 of 3 to 60 micrometers;
a Dv10 of 0.1 to 20 micrometers; or
a particle size distribution span of 1.05 to 3.5;

wherein Dv90, Dv50, Dv10 and particle size distribution span are determined by laser diffraction;
wherein the polycarbonate particles have a glass transition temperature of less than or equal to 140° C., determined using differential scanning calorimetry; and
wherein the polycarbonate particles have a residual gelatin content of less than 1000 parts per million.

20. An article comprising the polycarbonate particles of claim 18 .

Assignees

• Sabic Global Technologies Bv

Inventors

• Kuzeljevic Zeljko
• Kalyanaraman Viswanathan
• Patil Rahul
• Inamdar Kapil
• Anderson Zachary
• Hollar William E
• Kannamkumarath Sasi Sethumadhavan

Classifications

• C08J2369/00

  Characterised by the use of polycarbonates; Derivatives of polycarbonates · CPC title

• C08K5/5399

  Phosphorus bound to nitrogen · CPC title

• C08K5/5333

  Esters of phosphonic acids · CPC title

• C08J3/203

  Solid polymers with solid and/or liquid additives · CPC title

• C08J3/14 Primary

  by precipitation from solutions {(C08J3/122 takes precedence)} · CPC title