Method for producing granular polycarbonate prepolymer for solid-state polymerization

• US 5,981,051 A
• Filed: 03/02/1998
• Issued: 11/09/1999
• Est. Priority Date: 08/31/1995
• Status: Expired due to Fees

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Petrochemical Co., Ltd. (Idemitsu Kosan Company Limited)
• Inventors: Shishikura, Akihiro, Kunishi, Noriyuki, Motegi, Hiroaki
• Primary Examiner(s): Acquah, Samuel A.
• Application Number:
  US09/029,069
• Time in Patent Office: 617 Days
• Field of Search: 528/491, 528/492, 528/493, 528/494, 528/495, 528/496, 528/502, 528/503, 524/81, 524/220, 524/222, 524/356, 524/366, 524/367, 428/402, 428/143, 428/147, 428/304.4
• US Class Current: 428/304.4
• CPC Class Codes: B29B 9/12 characterised by structure or composition
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: C08G 64/20 General preparatory processes
• CPC Class Codes: C08J 2369/00 Characterised by the use of polycarbonates; Derivatives of polycarbonates
• CPC Class Codes: C08J 3/12 Powdering or granulating
• CPC Class Codes: C08J 3/14 by precipitation from solutions C08J3/122 takes precedence
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/24405 Polymer or resin [e.g., natural or synthetic rubber, etc.]
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

Provided is a method for producing a granular polycarbonate prepolymer for solid-phase polymerization, comprising dissolving a polycarbonate prepolymer in a solvent under heat, then crystallizing it by cooling, and shaping it. The grains of the granular prepolymer hardly fuse together in polymerization, and the granular prepolymer is suitable for high-speed solid-phase polymerization to give polycarbonate.

Claims

1. A method for producing polycarbonate prepolymer pellets for solid-phase polymerization, comprising dissolving a polycarbonate prepolymer in a solvent to form a prepolymer solution, passing the prepolymer solution through a tubular condenser to crystallize it into strands, and reducing said crystallized strands to predetermined lengths.

3. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 1, wherein the solvent is an aromatic solvent or a mixture of an aromatic solvent and a poor solvent for the polycarbonate prepolymer.

5. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 3, wherein the solvent is an aromatic solvent.

7. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 5, wherein the aromatic solvent is selected from the group consisting of benzene, toluene, o-xylene, m-xylene, p-xylene, dioxane, ethylbenzene, anisole, cumene, propylbenzene, naphthylene, mesitylene, dibenzyl ether, diphenyl ether, tetrahydronaphthylene, phenanthrene, anthracene, cyclohexanone, tetrahydrofuran and mixtures thereof.

9. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 1, wherein the granular polycarbonate prepolymer has a specific surface area of not smaller than 1 m² /g.

11. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 1, wherein the granular prepolymer contains fine powder in an amount of not larger than 5% by weight.

2. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization, comprising dissolving a polycarbonate prepolymer in a solvent to form a prepolymer solution, contacting the prepolymer solution with a cooling gas to crystallize the prepolymer and granulating the crystallized prepolymer.

4. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 2, wherein the solvent is an aromatic solvent or a mixture of an aromatic solvent and a poor solvent for the polycarbonate prepolymer.

6. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 4, wherein the solvent is an aromatic solvent.

8. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 6, wherein the aromatic solvent is selected from the group consisting of benzene, toluene, o-xylene, m-xylene, p-xylene, dioxane, ethylbenzene, anisole, cumene, propylbenzene, naphthylene, mesitylene, dibenzyl ether, diphenyl ether, tetrahydronaphthylene, phenanthrene, anthracene, cyclohexanone, tetrahydrofuran and mixtures thereof.

10. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 2, wherein the granular polycarbonate prepolymer has a specific surface area of not smaller than 1 m² /g.

12. A method for producing a granular polycarbonate prepolymer for solid-phase polymerization as claimed in claim 2, wherein the granular prepolymer contains fine powder in an amount of not larger than 5% by weight.