POLYESTER COPOLYMER FOR EXTRUSION

Abstract

The polyester copolymer according to the present disclosure can be extrusion-molded, and thus, can be usefully applied for the preparation of various containers.

Claims

1. Polyester copolymer comprising 1) residues of dicarboxylic acid components comprising terephthalic acid; 2) residues of diol components comprising cyclohexanedimethanol, ethyleneglycol, and isosorbide; and 3) residues of tri-functional compounds, and satisfying the following Mathematical Formula 1:
10%≤(V.sub.1−V.sub.0)/V.sub.0≤50%  [Mathematical Formula 1] in the Mathematical Formula 1, V.sub.0 is complex viscosity of polyester copolymer measured at 210° C. and 1 rad/s conditions, and V.sub.1 is complex viscosity measured two hundredth, when continuously measuring the complex viscosity of polyester copolymer at 210° C. and 1 rad/s conditions for 1 hour at an interval of 18 seconds.

2. The polyester copolymer according to claim 1, wherein the cyclohexanedimethanol residues are included in the content of 40 to 70 moles, based on 100 moles of the total diol component residues.

3. The polyester copolymer according to claim 1, wherein the ethyleneglycol residues are included in the content of 5 to 25 moles, based on 100 moles of the total diol component residues.

4. The polyester copolymer according to claim 1, wherein the isosorbide residues are included in the content of 0.1 to 12 moles, based on 100 moles of the total diol component residues.

5. The polyester copolymer according to claim 1, wherein the tri-functional compound is benzenetricarboxylic acid, or an anhydride thereof.

6. The polyester copolymer according to claim 1, wherein the tri-functional compound is benzene-1,2,3-tricarboxylic acid, benzene-1,2,3-tricarboxylic acid anhydride, benzene-1,2,4-tricarboxylic acid, or benzene-1,2,4-tricarboxylic acid anhydride.

7. The polyester copolymer according to claim 1, wherein the tri-functional compound residues are included in the content of 0.005 to 0.5 parts by weight, based on 100 parts by weight of the polyester copolymer.

8. A method for preparing the polyester copolymer according to claim 1, comprising steps of: subjecting dicarboxylic acid components, diol components, and tri-functional compounds to an esterification reaction (step 1); and subjecting the product of the step 1 to a polycondensation reaction (step 2).

9. The method according to claim 8, wherein the esterification reaction is conducted in the presence of an esterification catalyst comprising zinc acetate, zinc acetate dihydrate, zinc chloride, zinc sulfate, zinc sulfide, zinc carbonate, zinc citrate, zinc gluconate, or a mixture thereof.

10. The method according to claim 8, wherein the polycondensation reaction is conducted in the presence of a polycondensation catalyst comprising a titanium-based compound, a germanium-based compound, an antimony-based compound, an aluminum-based compound, a tin-based compound, or a mixture thereof.

11. An article comprising the polyester copolymer according to claim 1.

Description

MODE FOR INVENTION

[0048] Hereinafter, preferable examples will be presented to assist in understanding of the invention. However, these examples are only presented for better understanding of the invention, and the scope of the invention is not limited thereby.

Example 1

[0049] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (terephthalic acid; 2714.9 g), TMA (trimellitic anhydride; 7.70 g), EG (ethylene glycol; 766.0 g), CHDM (1,4-cyclohexanedimethanol; 1189.3 g), ISB (isosorbide; 4.8 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, cobalt acetate (0.7 g) as a coloring agent, Polysynthren Blue RLS (Clarient corporation, 0.012 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.004 g) as red toner.

[0050] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.0 kgf/cm.sup.2 (absolute pressure: 1495.6 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0051] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 270° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.80 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0052] The content of residue of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 2

[0053] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2629.2 g), TMA (7.70 g), EG (603.9 g), CHDM (1140.4 g), ISB (427.8 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, cobalt acetate (0.7 g) as a coloring agent, Polysynthren Blue RLS (Clarient corporation, 0.010 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.003 g) as red toner.

[0054] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.0 kgf/cm.sup.2 (absolute pressure: 1495.6 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 225° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 225° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0055] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 270° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.80 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0056] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 3

[0057] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (3008.3 g), TMA (2.08 g), EG (966.3 g), CHDM (1043.8 g), ISB (238.1 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.017 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.004 g) as red toner.

[0058] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 0.5 kgf/cm.sup.2 (absolute pressure: 1127.8 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 250° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 250° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0059] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 275° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.78 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0060] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 4

[0061] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (3272.9 g), TMA (2.50 g), EG (537.9 g), CHDM (1987.4 g), ISB (316.6 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, and cobalt acetate (1.1 g) as a coloring agent.

[0062] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.0 kgf/cm.sup.2 (absolute pressure: 1495.6 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0063] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 265° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.78 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0064] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 5

[0065] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2938.9 g), TMA (0.43 g), EG (559.8 g), CHDM (1529.6 g), ISB (103.4 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, and cobalt acetate (0.9 g) as a coloring agent.

[0066] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 2.0 kgf/cm.sup.2 (absolute pressure: 2231.1 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 265° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 265° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0067] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 285° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.79 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0068] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 6

[0069] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2597.2 g), TMA (19.00 g), EG (540.3 g), CHDM (1351.8 g), ISB (98.2 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, and phosphoric acid (5.0 g) as a stabilizer.

[0070] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.5 kgf/cm.sup.2 (absolute pressure: 1715.5 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0071] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 270° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.81 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0072] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 7

[0073] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (3034.7 g), TMA (0.42 g), EG (663.1 g), CHDM (1184.6 g), ISB (40.0 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.013 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.004 g) as red toner.

[0074] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.0 kgf/cm.sup.2 (absolute pressure: 1495.6 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 265° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 265° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0075] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 275° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.77 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0076] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Example 8

[0077] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2854.1 g), TMA (19.75 g), EG (675.8 g), CHDM (1114.1 g), ISB (40.2 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.020 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.008 g) as red toner.

[0078] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 0.5 kgf/cm.sup.2 (absolute pressure: 1127.8 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 268° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 268° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0079] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 275° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.80 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0080] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Comparative Example 1

[0081] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2586.6 g), EG (628.0 g), CHDM (1346.3 g), ISB (341.2 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.017 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.006 g) as red toner.

[0082] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 0.5 kgf/cm.sup.2 (absolute pressure: 1127.8 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0083] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 275° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.77 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0084] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Comparative Example 2

[0085] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2611.4 g), TMA (16.5 g), EG (253.6 g), CHDM (1699.0 g), ISB (436.4 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, and cobalt acetate (0.7 g) as a coloring agent.

[0086] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.0 kgf/cm.sup.2 (absolute pressure: 1495.6 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0087] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 280° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.81 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0088] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Comparative Example 3

[0089] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2952.4 g), TMA (2.0 g), EG (683.7 g), CHDM (896.4 g), ISB (207.7 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.012 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.004 g) as red toner.

[0090] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 0.5 kgf/cm.sup.2 (absolute pressure: 1127.8 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 265° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 265° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0091] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 280° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.79 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0092] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Comparative Example 4

[0093] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2156.1 g), TMA (6.4 g), EG (539.5 g), CHDM (935.2 g), ISB (436.2 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.010 g) as blue toner, and Solvaperm Red BB (Clarient corporation, 0.003 g) as red toner.

[0094] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.5 kgf/cm.sup.2 (absolute pressure: 1715.5 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0095] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 270° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.80 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0096] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Comparative Example 5

[0097] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2870.6 g), TMA (25.2 g), EG (707.6 g), CHDM (1494.1 g), ISB (101.0 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, and cobalt acetate (0.7 g) as a coloring agent.

[0098] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 2.0 kgf/cm.sup.2 (absolute pressure: 2231.1 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 265° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 265° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0099] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 270° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.81 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0100] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Comparative Example 6

[0101] Into a reactor with a capacity of 10 L to which a column, and a condenser that can be cooled by water are connected, TPA (2595.8 g), TMA (19.5 g), EG (533.2 g), CHDM (1576.3 g) were introduced, and GeO.sub.2 (2.0 g) was used as a catalyst, phosphoric acid (5.0 g) as a stabilizer, and cobalt acetate (0.8 g) as a coloring agent.

[0102] Subsequently, nitrogen was introduced into the reactor to pressurize the reactor such that the pressure of the reactor is higher than atmospheric pressure by 1.5 kgf/cm.sup.2 (absolute pressure: 1715.5 mmHg). Further, the temperature of the reactor was raised to 220° C. for 90 minutes, maintained at 220° C. for 2 hours, and then, raised to 260° C. for 2 hours. And then, the mixture in the reactor was observed with unaided eyes, and until the mixture became transparent, while maintaining the temperature of the reactor at 260° C., an esterification reaction was progressed. During this process, by-products were discharged through the column and condenser. After the esterification reaction was completed, nitrogen in the pressurized reactor was discharged outside to lower the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7 L in which a vacuum reaction can be progressed.

[0103] Further, the pressure of the reactor was lowered from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) for 30 minutes, and simultaneously, the temperature of the reactor was raised to 275° C. for 1 hour, and while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less, a polycondensation reaction was conducted. At the beginning of the polycondensation reaction, a stirring speed is set rapid, but as the polycondensation reaction progresses, in case stirring force decreases due to increase in the viscosity of the reactant or the temperature of the reactant increases beyond the established temperature, the stirring speed can be appropriately controlled. The polycondensation reaction was progressed until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor became 0.80 dl/g. If the intrinsic viscosity of the mixture in the reactor reached a desired level, the mixture was discharged outside the reactor to make strand, which was solidified with a coolant, and then, granulated such that the average weight became 12 to 14 mg.

[0104] The content of residues of each component included in the polyester copolymer thus prepared was shown in the following Table 1.

Experimental Example

[0105] For the copolymers prepared in the Examples and Comparative Examples, properties were evaluated as follows.

[0106] 1) Intrinsic Viscosity

[0107] The polyester copolymer was dissolved in 150° C. orthochlorophenol (OCP) at the concentration of 0.12%, and then, the intrinsic viscosity was measured using Ubbelohde viscometer in a constant-temperature bath of 35° C.

[0108] 2) Composition of Residues

[0109] The compositions (mol %) of residues derived from acid and diol in polyester resin were confirmed through 1H-NMR spectrum obtained using nuclear magnetic resonance device (JEOL, 600 MHz FT-NMR) at 25° C., after dissolving a sample in a CDCl.sub.3 solvent at the concentration of 3 mg/mL. Further, TMA residues were confirmed by quantitatively analyzing the content of benzene-1,2,4-triethylcarboxylate produced by the reaction of ethanol with TMA through ethanolysis, through the spectrum measured using gas chromatography (Agilent Technologies, 7890B) at 250° C., and contents (wt %) based on the total weight of polyester resin were confirmed.

[0110] 3) Viscosity Change

[0111] Using Physica MCR 301 equipment of Anton Paar, for the polyester copolymers prepared in Examples and Comparative Examples, complex viscosity at 210° C. and a shear rate of 1.0 rad/s under nitrogen was measured (V.sub.0, Pa.Math.s). When measuring, parallel plates with a diameter of 25 mm were positioned parallel at an interval of 1 mm to 2 mm. And then, while rotating at 1 rad/s, complex viscosity was continuously measured every 18 seconds for 1 hour, and the two hundredth measurement value was confirmed as the final complex viscosity (V.sub.1, Pa.Math.s). The measured V.sub.0 and V.sub.1 were substituted in the following Mathematical Formula to calculate viscosity change.

Viscosity change=(V.sub.1−V.sub.0)/V.sub.0

[0112] The above results were shown in the following Table 1.

TABLE-US-00001 TABLE 1 Intrinsic Viscosity TPA EG CHDM ISB TMA viscosity change Unit mol % mol % mol % mol % wt % dl/g % Example 1 100 49.9 50 0.1 0.2 0.80 35 Example 2 100 38 50 12 0.2 0.80 30 Example 3 100 55 40 5 0.05 0.78 15 Example 4 100 25 70 5 0.05 0.78 20 Example 5 100 38 60 2 0.01 0.79 10 Example 6 100 38 60 2 0.5 0.81 45 Example 7 100 54 45 1 0.01 0.77 13 Example 8 100 54 45 1 0.5 0.80 47 Comparative 100 33 60 7 0 0.77 0 Example 1 Comparative 100 15 75 10 0.4 0.81 55 Example 2 Comparative 100 65 35 5 0.05 0.79 5 Example 3 Comparative 100 35 50 15 0.2 0.80 8 Example 4 Comparative 100 38 60 2 0.6 0.81 65 Example 5 Comparative 100 30 70 0 0.5 0.80 60 Example 6