Polycarbonate and preparation method thereof

Abstract

Provided is a polycarbonate of Chemical Formula 1: ##STR00001## wherein in Chemical Formula 1: Ar is C.sub.6-60 arylene unsubstituted or substituted with C.sub.1-10 alkyl; and n and m are each independently an integer from 1 to 50, provided that n+m is 2 or more, and a preparation method thereof.

Claims

1. A polycarbonate, comprising a repeating unit of the following Chemical Formula 1: ##STR00018## wherein in Chemical Formula 1: Ar is C.sub.6-60 arylene unsubstituted or substituted with C.sub.1-10 alkyl; and n and m are each independently an integer from 1 to 50, provided that n+m is 2 or more.

2. The polycarbonate of claim 1, wherein the repeating unit of Chemical Formula 1 has a structure of one of the following Chemical Formulae 1a to 1c: ##STR00019## wherein in Chemical Formulae 1a to 1c, n and m are each independently an integer from 1 to 50, provided that n+m is 2 or more.

3. The polycarbonate of claim 1, further comprising a repeating unit of the following Chemical Formula 2: ##STR00020## wherein in Chemical Formula 2: R.sub.1 to R.sub.4 are each independently hydrogen, C.sub.1-10 alkyl, C.sub.1-10 alkoxy, or halogen; and Z is C.sub.1-10 alkylene unsubstituted or substituted with phenyl, C.sub.3-15 cycloalkylene unsubstituted or substituted with C.sub.1-10 alkyl, O, S, SO, SO.sub.2, or CO.

4. The polycarbonate of claim 3, wherein R.sub.1 to R.sub.4 are each independently hydrogen or C.sub.1-4 alkyl.

5. The polycarbonate of claim 3, wherein a weight ratio of the repeating unit of Chemical Formula 1 and the repeating unit of Chemical Formula 2 is 5:95 to 40:60.

6. The polycarbonate of claim 1, wherein a weather resistance index (ΔE) calculated according to the following Equation 1 is 1 to 15, and a melt index measured in accordance with ASTM D1238 (300° C., 1.2 kg condition) is 8 to 120 g/10 min:
ΔE=√{square root over (((L′−L).sup.2+(a′−a).sup.2+(b′−b).sup.2))}  Equation 1 wherein in Equation 1, L, a and b are measured for a specimen with a thickness of ⅛ inch in accordance with ASTM D7869, and L′, a′ and b′ are measured after leaving the specimen in 2250 hr weathering condition.

7. A method of preparing the polycarbonate of claim 1, comprising polymerizing a composition containing a compound of the following Chemical Formula 3 and a carbonate precursor: ##STR00021## wherein in Chemical Formula 3: Ar is C.sub.6-60 arylene unsubstituted or substituted with C.sub.1-10 alkyl; and n and m are each independently an integer from 1 to 50, provided that n+m is 2 or more.

8. The method of claim 7, wherein the compound of Chemical Formula 3 has a structure of one of the following Chemical Formulae 3a to 3c: ##STR00022## wherein in Chemical Formulae 3a to 3c, n and m are each independently an integer from 1 to 50, provided that n+m is 2 or more.

9. The method of claim 7, wherein the composition further contains an aromatic diol compound of the following Chemical Formula 4: ##STR00023## wherein in Chemical Formula 4: R.sub.1 to R.sub.4 are each independently hydrogen, C.sub.1-10 alkyl, C.sub.1-10 alkoxy, or halogen; and Z is a C.sub.1-10 alkylene unsubstituted or substituted with phenyl, C.sub.3-15 cycloalkylene unsubstituted or substituted with C.sub.1-10 alkyl, O, S, SO, SO.sub.2, or CO.

10. The method of claim 9, wherein the aromatic diol compound of Chemical Formula 4 is selected from the group consisting of bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, and 1,1-bis(4-hydroxyphenyl)-1-phenylethane.

11. A molded article, comprising the polycarbonate of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a .sup.1H-NMR graph of the compound prepared in Example 1.

(2) FIG. 2 is a .sup.1H-NMR graph of the compound prepared in Example 3.

(3) FIG. 3 is a .sup.1H-NMR graph of the compound prepared in Example 5.

(4) FIG. 4 is a .sup.1H-NMR graph of the compound prepared in Example 6.

(5) FIG. 5 is a .sup.1H-NMR graph of the compound prepared in Example 8.

(6) FIG. 6 is a .sup.1H-NMR graph of the compound prepared in Example 10.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(7) The present disclosure will be described in more detail through the following embodiments. However, the following embodiments are provided only for the purpose of illustrating the present disclosure, and thus the present disclosure is not limited thereto.

EXAMPLES

Preparation of Polycarbonate

Example 1

(1) Preparation of resorcinol 3-HB (1,3-phenylene bis(3-hydroxybenzoate) oligomer)

(8) ##STR00011##

(9) 5 g of resorcinol was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 25.1 g of 1,3-hydroxybenzoic acid was added dropwise thereto. Thereafter, 23 g of oxalyl chloride and 0.01 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. The solvent was removed using a rotary evaporator under reduced pressure to obtain a 1,3-phenylene bis(3-hydroxybenzoate) oligomer.

(10) In addition, the obtained 1,3-phenylene bis(3-hydroxybenzoate) oligomer was subjected to an acid-base work-up process using 1N NaOH, 1N HCl aqueous solution, and methylene chloride solvent, and then a 1,3-phenylene bis(3-hydroxybenzoate) oligomer (weight average molecular weight: 780 g/mol) was obtained with a crude yield of 95% without any other purification.

(11) .sup.1H NMR (in CDCl.sub.3) analysis was performed on the obtained 1,3-phenylene bis(3-hydroxybenzoate) oligomer (n+m=6), and the result is shown in FIG. 1.

(2) Preparation of Polycarbonate Resin

(12) 620 g of water, 112.61 g of BPA, 11.27 g of the 1,3-phenylene bis(3-hydroxybenzoate) oligomer prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(13) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the 1,3-phenylene bis(3-hydroxybenzoate) oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, a reaction pH was maintained at 11-13.

(14) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4. Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(15) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 46,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,3-phenylene bis(3-hydroxybenzoate) oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Example 2

(16) A polycarbonate was prepared in the same manner as in Example 1, except that 5.7 g of 1,3-phenylene bis(3-hydroxybenzoate) oligomer and 114.51 g of BPA were used. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,3-phenylene bis(3-hydroxybenzoate) oligomer is included in an amount of 30 wt % based on a total weight of the repeating units.

Example 3

(2) Preparation of hydroquinone 3-HB (1,4-phenylene bis(3-hydroxybenzoate) Oligomer)

(17) ##STR00012##

(18) 5 g of hydroquinone was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 25.1 g of 1,3-hydroxybenzoic acid was added dropwise thereto. Thereafter, 23 g of oxalyl chloride and 0.01 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. The solvent was removed using a rotary evaporator under reduced pressure to obtain a 1,4-phenylene bis(3-hydroxybenzoate) oligomer.

(19) In addition, the obtained 1,4-phenylene bis(3-hydroxybenzoate) oligomer was subjected to an acid-base work-up process using 1N NaOH, 1N HCl aqueous solution, and methylene chloride solvent, and then a 1,4-phenylene bis(3-hydroxybenzoate) oligomer (weight average molecular weight: 1,100 g/mol) was obtained with a crude yield of 93% without any other purification.

(20) .sup.1H NMR (in Acetone-d6) analysis was performed on the obtained 1,4-phenylene bis(3-hydroxybenzoate) oligomer (n+m=10), and the result is shown in FIG. 2.

(2) Preparation of Polycarbonate Resin

(21) 620 g of water, 112.61 g of BPA, 11.27 g of the 1,4-phenylene bis(3-hydroxybenzoate) oligomer prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(22) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the 1,4-phenylene bis(3-hydroxybenzoate) oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13.

(23) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4. Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(24) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 45,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,4-phenylene bis(3-hydroxybenzoate) oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Example 4

(25) A polycarbonate was prepared in the same manner as in Example 3, except that 5.7 g of 1,4-phenylene bis(3-hydroxybenzoate) oligomer and 114.51 g of BPA were used.

(26) As a result of NMR analysis, it was identified that the repeating unit derived from the 1,4-phenylene bis(3-hydroxybenzoate) oligomer is included in an amount of 30 wt % based on a total weight of the repeating units.

Example 5

(1) Preparation of BPA 3-HB (propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) Oligomer)

(27) ##STR00013##

(28) 10.37 g of BPA was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 25.1 g of 1,3-hydroxybenzoic acid was added dropwise thereto. Thereafter, 23 g of oxalyl chloride and 0.01 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. The solvent was removed using a rotary evaporator under reduced pressure to obtain a propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer.

(29) In addition, the obtained propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer was subjected to an acid-base work-up process using 1N NaOH, 1N HCl aqueous solution, and methylene chloride solvent, and then a propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer (weight average molecular weight: 1,000 g/mol) was obtained with a crude yield of 95% without any other purification.

(30) .sup.1H NMR (in CDCl.sub.3) analysis was performed on the obtained propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer, and the result is shown in FIG. 3.

(2) Preparation of Polycarbonate Resin

(31) 620 g of water, 113.21 g of BPA, 12.3 g of the propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(32) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13.

(33) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4. Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(34) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 49,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the propane-2,2-diylbis(4,1-phenylene) bis(3-hydroxybenzoate) oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Example 6

(1) Preparation of resorcinol 4-HB (1,3-phenylene bis(4-hydroxybenzoate) Oligomer)

(35) ##STR00014##

(36) 5 g of resorcinol was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 25.1 g of 1,3-hydroxybenzoic acid was added dropwise thereto. Thereafter, 23 g of oxalyl chloride and 0.01 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. The solvent was removed using a rotary evaporator under reduced pressure to obtain a 1,3-phenylene bis(4-hydroxybenzoate) oligomer.

(37) In addition, the obtained 1,3-phenylene bis(4-hydroxybenzoate) oligomer was subjected to an acid-base work-up process using 1N NaOH, 1N HCl aqueous solution, and methylene chloride solvent, and then a 1,3-phenylene bis(3-hydroxybenzoate) oligomer (weight average molecular weight: 950 g/mol) was obtained with a crude yield of 96% without any other purification.

(38) .sup.1H NMR (in Acetone-d6) analysis was performed on the obtained 1,3-phenylene bis(4-hydroxybenzoate) oligomer (n+m=8), and the result is shown in FIG. 4.

(2) Preparation of Polycarbonate Resin

(39) 620 g of water, 112.61 g of BPA, 11.27 g of the 1,3-phenylene bis(4-hydroxybenzoate) oligomer prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(40) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the 1,3-phenylene bis(4-hydroxybenzoate) oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13.

(41) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4. Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(42) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 46,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,3-phenylene bis(4-hydroxybenzoate) oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Example 7

(43) A polycarbonate was prepared in the same manner as in Example 6, except that 5.7 g of 1,3-phenylene bis(4-hydroxybenzoate) oligomer and 114.51 g of BPA were used. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,3-phenylene bis(4-hydroxybenzoate) oligomer is included in an amount of 30 wt % based on a total weight of the repeating units.

Example 8

(1) Preparation of hydroquinone 4-HB (1,4-phenylene bis(4-hydroxybenzoate) Oligomer)

(44) ##STR00015##

(45) 5 g of hydroquinone was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 25.1 g of 1,4-hydroxybenzoic acid was added dropwise thereto. Thereafter, 23 g of oxalyl chloride and 0.01 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. The solvent was removed using a rotary evaporator under reduced pressure to obtain a 1,4-phenylene bis(4-hydroxybenzoate) oligomer.

(46) In addition, the obtained 1,4-phenylene bis(4-hydroxybenzoate) oligomer was subjected to an acid-base work-up process using 1N NaOH, 1N HCl aqueous solution, and methylene chloride solvent, and then a 1,4-phenylene bis(4-hydroxybenzoate) oligomer (weight average molecular weight: 820 g/mol) was obtained with a crude yield of 98% without any other purification.

(47) .sup.1H NMR (in CDCl.sub.3) analysis was performed on the obtained 1,4-phenylene bis(4-hydroxybenzoate) oligomer (n+m=7), and the result is shown in FIG. 5.

(2) Preparation of Polycarbonate Resin

(48) 620 g of water, 112.61 g of BPA, 11.27 g of the 1,4-phenylene bis(4-hydroxybenzoate) oligomer prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(49) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the 1,4-phenylene bis(4-hydroxybenzoate) oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13.

(50) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4.

(51) Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(52) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 48,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,4-phenylene bis(4-hydroxybenzoate) oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Example 9

(53) A polycarbonate was prepared in the same manner as in Example 8, except that 5.7 g of 1,4-phenylene bis(4-hydroxybenzoate) oligomer and 114.51 g of BPA were used. As a result of NMR analysis, it was identified that the repeating unit derived from the 1,4-phenylene bis(4-hydroxybenzoate) oligomer is included in an amount of 30 wt % based on a total weight of the repeating units.

Example 10

(1) Preparation of BPA 4-HB (propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) Oligomer)

(54) ##STR00016##

(55) 10.37 g of BPA was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 25.1 g of 1,3-hydroxybenzoic was added dropwise thereto. Thereafter, 23 g of oxalyl chloride and 0.01 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. The solvent was removed using a rotary evaporator under reduced pressure to obtain a propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer.

(56) In addition, the obtained propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer was subjected to an acid-base work-up process using 1N NaOH, 1N HCl aqueous solution, and methylene chloride solvent, and then a propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer (weight average molecular weight: 980 g/mol) was obtained with a crude yield of 95% without any other purification.

(57) .sup.1H NMR (in Acetone-d6) analysis was performed on the obtained propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer (n+m=7), and the result is shown in FIG. 6.

(2) Preparation of Polycarbonate Resin

(58) 620 g of water, 113.21 g of BPA, 12.3 g of the propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(59) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13. A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4. Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(60) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 46,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the propane-2,2-diylbis(4,1-phenylene) bis(4-hydroxybenzoate) oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Comparative Example 1

(61) 620 g of water, 116 g of BPA, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(62) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, a reaction pH was maintained at 11-13. A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4.

(63) Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was repeatedly performed three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again.

(64) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 46,300 g/mol.

Comparative Example 2

(1) Preparation of 3-((3-hydroxyphenoxy)carbonyl)benzoic Acid Oligomer

(65) ##STR00017##

(66) 5.1 g of resorcinol was added dropwise to 200 ml of methylene chloride solvent in a round flask, after which 200 g or water, 3.7 g of NaOH and 0.01 g of tetrabutylammonium bisulfate were added dropwise thereto. Thereafter, 5.9 g of terephthaloyl chloride was added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours to obtain a 3-((3-hydroxyphenoxy)carbonyl)benzoic acid oligomer. The synthesized oligomer was added in the preparation of a polycarbonate without any separate separation process.

(2) Preparation of Polycarbonate Resin

(67) 620 g of water, 115.077 g of BPA, 3-((3-hydroxyphenoxy)carbonyl)benzoic acid oligomer solution prepared in (1) above, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(68) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the 3-((3-hydroxyphenoxy)carbonyl)benzoic acid oligomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13.

(69) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4. Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding pure H.sub.2O theretoagain.

(70) When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 46,000 g/mol. As a result of NMR analysis, it was identified that the repeating unit derived from the 3-((3-hydroxyphenoxy)carbonyl)benzoic acid oligomer is included in an amount of 10 wt % based on a total weight of the repeating units.

Comparative Example 3

(71) 620 g of water, 108.9 g of BPA, 11.38 g of 1,4-phenylene bis(4-hydroxybenzoate) monomer, 102.5 g of 40 wt % NaOH aqueous solution, and 200 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and kept at room temperature with a circulator, and then stirred for minutes.

(72) After stopping nitrogen purging, 62 g of triphosgene and 120 g of MeCl.sub.2 were put into a 1 L round-bottom flask to dissolve triphosgene therein, after which a resulting dissolved triphosgene solution was slowly put into the main reactor, in which BPA and the 1,4-phenylene bis(4-hydroxybenzoate) monomer solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was added thereto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was added thereto, and 1.16 g of TEA was added thereto as a coupling agent. At this time, the reaction pH was maintained at 11-13.

(73) A resulting mixture was left alone for a while to fully carry out a reaction, after which HCl was added thereto to finish the reaction, such that the pH was dropped to 3-4.

(74) Then, agitation was stopped, after which a polymer layer and a water layer were separated from each other, such that a rinsing process was performed repeatedly three to five times by removing the water layer therefrom and adding thereto pure H.sub.2O again. When rinsing was completely done, only the polymer layer was extracted therefrom, after which a polymer crystal was obtained via reprecipitation by using non-solvents such as methanol, H.sub.2O, etc. At this time, a weight average molecular weight of the polycarbonate prepared was 48,000 g/mol.

EXPERIMENTAL EXAMPLES

Evaluation of Physical Properties of Polycarbonate

(75) The characteristics of injection-molded specimens of polycarbonates prepared in Examples and Comparative Examples above were measured by means of the following method, and the results thereof are shown in Table 1.

(76) Weight average molecular weight (g/mol): 200 mg of polymer resin was diluted in 200 ml of tetrahydrofuran (THF) solvent to manufacture a sample of about 1000 ppm. Then, a molecular weight thereof was measured with an RI detector at 1 ml/min flow by using Agilent 1200 series GPC equipment. With regard to criteria for calculating a molecular weight of the sample, a calibration curve was drawn up by measuring eight PS standards, after which the molecular weight of the sample was calculated accordingly.

(77) Flowability (MI): Measured in accordance with ASTM D1238 (300° C., 1.2 kg condition).

(78) Weather resistance index (ΔE): Measured for a specimen with a thickness of ⅛ inch by measuring L, a, and b values of the specimen in accordance with ASTM D7869 and measuring L′, a′ and b′ values again after leaving the specimen in 2250 hr weathering condition with Weather-Ometer® machine. From the results, the weather resistance index (ΔE) was calculated according to the following Equation 1.
ΔE=√{square root over (((L′−L).sup.2+(a′−a).sup.2+(b−b).sup.2)})  Equation 1

(79) TABLE-US-00001 TABLE 1 Type and weight ratio Weather of repeating unit of Mw Ml resistance Chemical Formula 1 (g/mol) (g/10 min) index (ΔE) Example 1 Resorcinol 3-HB 46,000 15.4 4.5 oligomer, 10 wt % Example 2 Resorcinol 3-HB 45,000 15.9 7.5 oligomer, 30 wt % Example 3 Hydroquinone 3-HB 45,000 16.1 4.6 oligomer, 10 wt % Example 4 Hydroquinone 3-HB 44,000 18 7.9 oligomer, 30 wt % Example 5 BPA 3-HB oligomer, 49,000 11.6 4.5 10 wt % Example 6 Resorcinol 4-HB 46,000 15 5.3 oligomer, 10 wt % Example 7 Resorcinol 4-HB 45,000 16.7 8.3 oligomer, 30 wt % Example 8 Hydroquinone 4-HB 48,000 13.3 5.1 oligomer, 10 wt % Example 9 Hydroquinone 4-HB 46,000 14.9 4.9 oligomer, 30 wt % Example 10 BPA 4-HB oligomer, 47,000 13 4.8 10 wt % Comparative — 46,000 11.8 31 Example 1 Comparative 3-((3-hydroxyphenoxy) 48,000 10.3 17 Example 2 carbonyl)benzoic acid oligomer*, 10 wt % Comparative Hydroquinone 4-HB 48,000 11 24.5 Example 3 monomer*, 10 wt % (*In Comparative Examples 2 and 3, the kind of a repeating unit corresponding to a repeating unit of Chemical Formula 1 was described.)

(80) With reference to the above Table 1, in case of all the Examples including the repeating unit of the present disclosure, weather resistance and flowability were significantly improved than the general BPA polycarbonate of the Comparative Example 1 or polycarbonates of the Comparative Examples 2 to 3. In particular, an effect of improving weather resistance was highest when the repeating unit of the Chemical Formula 1 was included in an amount of about 10 wt %.