POLYCARBONATE AND PREPARATION METHOD THEREOF

Abstract

The present disclosure relates to a polycarbonate and a preparation method thereof, which has a novel structure with an improvement in weather resistance and refractive index, while having excellent mechanical properties.

Claims

1. A polycarbonate, comprising a repeating unit represented by Chemical Formula 1: ##STR00013## wherein, in Chemical Formula 1, X is C.sub.6-60 arylene unsubstituted or substituted with C.sub.1-10 alkyl, Y is C.sub.1-10 alkylene, and n is an integer of 1 to 10.

2. The polycarbonate of claim 1, wherein Y is C.sub.1-5 alkylene.

3. The polycarbonate of claim 1, wherein X is one of structures represented by the following structural formulae: ##STR00014##

4. The polycarbonate of claim 1, further comprising a repeating unit represented by Chemical Formula 2: ##STR00015## 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.

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

6. The polycarbonate of claim 4, wherein the repeating unit represented by Chemical Formula 1 is included in an amount of 5 wt % to 50 wt % based on a total weight of the repeating units.

7. The polycarbonate of claim 4, wherein the repeating unit represented by the Chemical Formula 1 is included in an amount of more than 50 wt % and 99 wt % or less based on a total weight of the repeating units.

8. The polycarbonate of claim 1, wherein a refractive index (nD) of the polycarbonate measured in accordance with JIS-K-7142 is 1.58 to 1.70.

9. The polycarbonate of claim 1, wherein a weather resistance index (ΔE) of the polycarbonate is 30 or less, calculated according to Equation 1 by measuring L, a, and b values of a specimen in accordance with ASTM D7869 and measuring L′, a′ and b′ values again after leaving the specimen in 2250 hr weathering condition:
ΔE=√{square root over (((L′−L).sup.2+(a′−a).sup.2+(b′−b).sup.2))}  [Equation 1]

10. The polycarbonate of claim 1, wherein a melt index of the polycarbonate measured in accordance with ASTM D1238 (300° C., 1.2 kg condition) is 10 g/10 min to 50 g/10 min.

11. A method of preparing the polycarbonate of claim 1, comprising a step of: polymerizing a composition containing a compound represented by Chemical Formula 3, and a carbonate precursor: ##STR00016## wherein, in Chemical Formula 3, X is C.sub.6-60 arylene unsubstituted or substituted with C.sub.1-10 alkyl, Y is C.sub.1-10 alkylene, and n is an integer of 1 to 10.

12. The preparation method of the polycarbonate of claim 11, wherein X in Chemical Formula 3 is one of structures represented by the following structural formulae: ##STR00017##

13. The method of claim 11, wherein the compound represented by Chemical Formula 3 is one of compounds represented by the following structural formulae: ##STR00018## wherein, in the above structural formulae, n is as defined in Chemical Formula 3.

14. The method of claim 11, wherein the composition further contains an aromatic diol compound represented by Chemical Formula 4: ##STR00019## 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 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.

15. The method of claim 14, wherein the aromatic diol compound represented by the Chemical Formula 4 is at least one compound 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.

16. A molded article comprising the polycarbonate of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0073] FIG. 1 is a .sup.1H-NMR graph of the compound prepared in Example 1.

[0074] FIG. 2 is a .sup.1H-NMR graph of the polycarbonate prepared in Example 1.

[0075] FIG. 3 is a .sup.1H-NMR graph of the compound prepared in Example 2.

[0076] FIG. 4 is a .sup.1H-NMR graph of the compound prepared in Example 3.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0077] 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 BP-DTDPA (bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate)

[0078] ##STR00010##

[0079] 15 g of 3,3′-disulfanediyldipropionic acid was dissolved in 100 ml of methylene chloride solvent in a round flask, after which 19.9 g of oxalyl chloride and 0.25 g of DMF were added dropwise thereto at room temperature, and stirred at room temperature for about 4 hours. When a resulting reactant became transparent and did not cause any foams, the reactant was slowly added to 33.4 g of bisphenol A, 33.9 g of pyridine and 200 ml of methylene chloride solvent without a separate purification process, and stirred at room temperature for 24 hours. 50 ml of 35% HCl was added thereto to finish the reaction, and then washed with water and dichloromethane. A final compound, i.e., bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate (weight average molecular weight: 1,800 g/mol) was obtained with a final yield of 97%. At this time, the compound was obtained in a form of mixtures thereof, wherein n is 1 to 4, respectively.

[0080] .sup.1H-NMR of the compound is shown in FIG. 1.

(2) Preparation of Polycarbonate Resin

[0081] 247 g of water, 166.5 g of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate prepared in (1) above, 41 g of 40 wt % NaOH, and 165 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and might be kept at room temperature with a circulator, and then stirred for minutes.

[0082] After stopping nitrogen purging, 25 g of triphosgene and 48 ml 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 BP-DTDPA solution had been dissolved. After such input was completed, 1.1 g of PTBP (p-tert-butylphenol) was put thereinto and stirred for about 10 minutes. Such agitation was completed, after which 39.8 g of 40 wt % NaOH aqueous solution was put thereinto, such that 0.43 g of TEA was put thereinto 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 put thereinto 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 putting pure H.sub.2O thereinto again.

[0083] 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 based on PS standard.

[0084] .sup.1H-NMR of the polycarbonate is shown in FIG. 2.

Example 2

(1) Preparation of BHP-DTDPA (bis(3-hydroxyphenyl) 3,3′-dithiodiyldipropionate)

[0085] ##STR00011##

[0086] Synthesis was performed in the same manner as in Example 1, except that 15 g of 3,3′-disulfanediyldipropionic acid of Example 1 was used, and 19.92 g of oxalyl chloride, 0.24 g of DMF, 16.1 g of resorcinol instead of bisphenol A, and 33.9 g of pyridine were used.

[0087] A final compound, i.e., bis(3-hydroxyphenyl) 3,3′-dithiodiyldipropionate (weight average molecular weight: 989 g/mol) was obtained with a final yield of 91%. At this time, the compound was obtained in a form of mixtures thereof, wherein n is 1 to 4, respectively.

[0088] .sup.1H-NMR of the compound is shown in FIG. 3.

(2) Preparation of Polycarbonate Resin

[0089] Synthesis was performed in the same manner as in Example 1, except that 104.08 g of bis(3-hydroxyphenyl) 3,3′-dithiodiyldipropionate was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate of Example 1. At this time, a weight average molecular weight of the polycarbonate prepared was 47,000 g/mol based on PS standard.

Example 3

(1) Preparation of BPF-DTDPA (bis(4-(9-(4-hydroxyphenyl)-9H-fluoren-9-yl)phenyl) 3,3′-dithiodiyldipropionate)

[0090] ##STR00012##

[0091] Synthesis was performed in the same manner as in Example 1, except that 15 g of 3,3′-disulfanediyldipropionic acid of Example 1 was used, and 19.92 g of oxalyl chloride, 0.24 g of DMF, 51.2 g of 4,4′-(9H-fluorene-9,9-diyl)diphenol instead of bisphenol A, and 33.9 g of pyridine were used.

[0092] A final compound, i.e., bis(4-(9-(4-hydroxyphenyl)-9H-fluoren-9-yl)phenyl) 3,3′-dithiodiyldipropionat (weight average molecular weight: 2,000 g/mol) was obtained with a final yield of 87%. At this time, the compound was obtained in a form of mixtures thereof, wherein n is 1 to 4, respectively.

[0093] .sup.1H-NMR of the compound is shown in FIG. 4.

(2) Preparation of Polycarbonate Resin

[0094] Synthesis was performed in the same manner as in Example 1, except that 230.9 g of bis(4-(9-(4-hydroxyphenyl)-9H-fluoren-9-yl)phenyl) 3,3′-dithiodiyldipropionate was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate of Example 1. At this time, a weight average molecular weight of the polycarbonate prepared was 50,000 g/mol based on PS standard.

Example 4

[0095] 619 g of water, 15.4 g of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate (BP-DTDPA) prepared in (1) of Example 1 above, 111.3 g of bisphenol A, 102.5 g of 40 wt % NaOH, and 195 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and might be kept at room temperature with a circulator, and then stirred for minutes.

[0096] After stopping nitrogen purging, 62.81 g of triphosgene and 120 ml 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 a mixed solution of BP-DTDPA and BPA had been dissolved. After such input was completed, 2.5 g of PTBP (p-tert-butylphenol) was put thereinto and stirred for about 10 minutes. Such agitation was completed, after which 99.4 g of 40 wt % NaOH aqueous solution was put thereinto, such that 1.04 g of TEA was put thereinto 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 put thereinto 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 repeatedly performed three to five times by removing the water layer therefrom and putting pure H.sub.2O thereinto again.

[0097] 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 based on PS standard. As a result of NMR analysis, it was identified that the repeating unit derived from BP-DTDPA is included by 10 wt % based on a total weight of the repeating units.

Example 5

[0098] Polymerization was performed in the same manner as in Example 4, except that 15.8 g of bis(3-hydroxyphenyl) 3,3′-dithiodiyldipropionate (BHP-DTDPA) monomer prepared in (1) of Example 2 was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate in Example 4, and 111.6 g of bisphenol A was used. At this time, a weight average molecular weight of the polycarbonate prepared was 48,000 g/mol based on PS standard. Also, as a result of NMR analysis, it was identified that the repeating unit derived from BHP-DTDPA is included by 10 wt % based on a total weight of the repeating units.

Example 6

[0099] Polymerization was performed in the same manner as in Example 4, except that 15.4 g of bis(4-(9-(4-hydroxyphenyl)-9H-fluoren-9-yl)phenyl) 3,3′-dithiodiyldipropionate (BPF-DTDPA) monomer prepared in (1) of Example 3 was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate in Example 4, and 111.3 g of bisphenol A was used. At this time, a weight average molecular weight of the polycarbonate prepared was 49,000 g/mol based on PS standard. As a result of NMR analysis, it was identified that the repeating unit derived from BPF-DTDPA is included by 10 wt % based on a total weight of the repeating units.

Example 7

[0100] Polymerization was performed in the same manner as in Example 4, except that 7.62 g of BPF-DTDPA monomer prepared in (1) of Example 3 was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate in Example 4, and 115 g of bisphenol A was used. At this time, a weight average molecular weight of the polycarbonate prepared was 49,000 g/mol based on PS standard. As a result of NMR analysis, it was identified that the repeating unit derived from BPF-DTDPA is included by 5 wt % based on a total weight of the repeating units.

Example 8

[0101] Polymerization was performed in the same manner as in Example 4, except that 42.7 g of BPF-DTDPA monomer prepared in (1) of Example 3 was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate in Example 4, and 107.9 g of bisphenol A was used. At this time, a weight average molecular weight of the polycarbonate prepared was 49,000 g/mol based on PS standard. As a result of NMR analysis, it was identified that the repeating unit derived from BPF-DTDPA is included by 30 wt % based on a total weight of the repeating units.

Example 9

[0102] Polymerization was performed in the same manner as in Example 4, except that 68.1 g of BPF-DTDPA monomer prepared in (1) of Example 3 was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate in Example 4, and 102.7 g of bisphenol A was used. At this time, a weight average molecular weight of the polycarbonate prepared was 49,000 g/mol based on PS standard. As a result of NMR analysis, it was identified that the repeating unit derived from BPF-DTDPA is included by 50 wt % based on a total weight of the repeating units.

Example 10

[0103] Polymerization was performed in the same manner as in Example 4, except that 91.2 g of BPF-DTDPA monomer prepared in (1) of Example 3 was used instead of bis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) 3,3′-dithiodiyldipropionate in Example 4, and 98.07 g of bisphenol A was used. At this time, a weight average molecular weight of the polycarbonate prepared was 50,000 g/mol based on PS standard. As a result of NMR analysis, it was identified that the repeating unit derived from BPF-DTDPA is included by 70 wt % based on a total weight of the repeating units.

Comparative Example 1

[0104] 619 g of water, 116.5 g of bisphenol A, 102.5 g of 40 wt % NaOH, and 195 ml of MeCl.sub.2 were put into a 2 L main reactor which is equipped with a nitrogen purge and a condenser and might be kept at room temperature with a circulator, and then stirred for minutes.

[0105] After stopping nitrogen purging, 62.81 g of triphosgene and 120 ml 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 had been dissolved. After such input was completed, 2.5 g of PTBP (p-tert-butylphenol) was put thereinto and stirred for about 10 minutes. Such agitation was completed, after which 99.4 g of 40 wt % NaOH aqueous solution was put thereinto, such that 1.04 g of TEA was put thereinto 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 put thereinto 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 repeatedly performed three to five times by removing the water layer therefrom and putting pure H.sub.2O thereinto again.

[0106] 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 based on PS standard.

Comparative Example 2

[0107] First, bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate (BP-TDPA) was prepared according to Example 1 of KR publication No. 2017-0027256.

[0108] 620 g of water, 116.24 g of bisphenol A, 12.6 g of bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate (BP-TDPA), 102.5 g of NaOH, 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 might be kept at room temperature with a circulator, and then stirred for minutes.

[0109] 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 BP-TDPA solution had been dissolved. After such input was completed, 2.66 g of PTBP (p-tert-butylphenol) was put thereinto and stirred for about 10 minutes. Such agitation was completed, after which 97 g of 40 wt % NaOH aqueous solution was put thereinto, such that 1.16 g of TEA was put thereinto 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 put thereinto 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 repeatedly performed three to five times by removing the water layer therefrom and putting pure H.sub.2O thereinto again.

[0110] 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 based on PS standard.

Experimental Examples: Evaluation of Physical Properties of Polycarbonate

[0111] 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. [0112] Weight average molecular weight (Mw): 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. [0113] Flowability (MI): Measured in accordance with ASTM D1238 (300° C., 1.2 kg condition). [0114] Glass transition temperature (Tg, ° C.): Measured using differential scanning calorimetry (DSC). [0115] Refractive index (nD): Measured for a specimen with a thickness of ⅛ inch in accordance with JIS-K-7142 by using an abbe refractometer (23° C., wavelength of 589 nm). [0116] 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 Formula 1.

ΔE=√{square root over (((L′−L).sup.2+(a′−a).sup.2+(b′−b).sup.2))}  [Equation 1]

TABLE-US-00001 TABLE 1 Type and weight ratio of Molecular repeating unit of weight MI Refractive Weather resistance Chemical Formula 1 (g/mol) (g/10 min) index (nD) index (ΔE) Example 1 BP-DTDPA, 49,000 31 1.60 27 100 wt % Example 2 BHP-DTDPA, 47,000 38 1.59 23 100 wt % Example 3 BPF-DTDPA, 50,000 26 1.68 21 100 wt % Example 4 BP-DTDPA, 49,000 24 1.58 7 10 wt % Example 5 BHP-DTDPA, 48,000 28 1.58 8 10 wt % Example 6 BPF-DTDPA, 49,000 20 1.59 7 10 wt % Example 7 BPF-DTDPA, 49,000 18 1.58 9 5 wt % Example 8 BPF-DTDPA, 49,000 21 1.61 10 30 wt % Example 9 BPF-DTDPA, 49,000 23 1.63 14 50 wt % Example 10 BPF-DTDPA, 50,000 25 1.65 19 70 wt % Comparative 0 wt % 49,000 15 1.58 32 Example 1 Comparative BP-TDPA*, 50,000 18 1.58 7 Example 2 10 wt % (*In Comparative Example 2, the kind of a repeating unit corresponding to a repeating unit of Chemical Formula 1 was described.)

[0117] With reference to the above Table 1, the polycarbonate prepared by using a monomer including a fluorene structure out of the monomers of the Chemical Formula 3 showed excellent refractive characteristics.

[0118] Meanwhile, in case of all the Examples including the repeating unit of the present disclosure, weather resistance was more excellent than the general BPA polycarbonate of the Comparative Example 1. In particular, an effect of improving weather resistance was highest when the repeating unit of the Chemical Formula 1 was included by 50 wt % or less, and more preferably by about 10 wt %.

[0119] In addition, when comparing Comparative Example 2 including a thiodipropionate-derived repeating unit containing only one sulfur atom with Example 4 including the same content of the dithiodipropionate-derived repeating unit, it was confirmed that Example 4 had significantly improved fluidity.

[0120] When considering the results as above, in case of preparing a polycarbonate for the purpose of a high refractive index such as lens, it is preferable to include a high content of the monomer of the Chemical Formula 3 having the fluorene structure. In case of preparing a polycarbonate requiring weather resistance, it is advantageous to include a low content of the monomer of the Chemical Formula 3. Thus, it appears that the polycarbonate with desired physical properties can be prepared by adjusting the content and the monomer thereof suitably for its purposes.