COPOLYCARBONATE AND METHOD FOR PREPARING THE SAME

Abstract

Provided are a copolycarbonate having superior weather resistance as well as excellent mechanical properties, and a preparation method thereof.

Claims

1. A copolycarbonate, comprising a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by the following Chemical Formula 2, and having a weight average molecular weight of 1,000 to 100,000 g/mol: ##STR00006## wherein R.sub.1 to R.sub.8 are each independently hydrogen or C.sub.1-10 alkyl, Y is C.sub.1-10 alkylene, Z is a bond, —OCO—, or —COO—, and X.sub.1 to X.sub.2 are each independently 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, ##STR00007## wherein R.sub.9 to R.sub.12 are each independently hydrogen, C.sub.1-10 alkyl, C.sub.1-10 alkoxy, or halogen, and X.sub.3 is C.sub.1-19 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.

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

3. The copolycarbonate of claim 1, wherein R.sub.1 to R.sub.8 are each independently hydrogen or C.sub.1-4 alkyl.

4. The copolycarbonate of claim 1, wherein a molar ratio of the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2 is 1:0.001 to 1:1.

5. The copolycarbonate of claim 1, wherein a change in yellow index (dYI) is 20 or less, as measured in accordance with ASTM G155.

6. A preparation method of the copolycarbonate of claim 1, the method comprising the step of polymerizing a composition comprising a compound represented by the following Chemical Formula 3, an aromatic diol compound, and a carbonate precursor: ##STR00008## wherein R.sub.1 to R.sub.8 are each independently hydrogen or C.sub.1-10 alkyl, Y is C.sub.1-10 alkylene, Z is a bond, —OCO—, or —COO—, and X.sub.1 to X.sub.2 are 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.

7. The preparation method of claim 6, wherein the compound represented by Chemical Formula 3 is used in an amount of 0.1% by weight or more and 20% by weight or less, based on 100% by weight of the composition.

8. A molded article manufactured by using the copolycarbonate of claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a .sup.1H-NMR graph of a compound prepared in Example 1; and

[0046] FIG. 2 is a .sup.1H-NMR graph of a copolycarbonate prepared in Example 1.

ADVANTAGEOUS EFFECTS

[0047] According to the present invention, provided are a copolycarbonate having superior weather resistance as well as excellent mechanical properties, and a preparation method thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The present invention will be described in more detail with reference to the following

[0049] Examples. However, the following Examples are for illustrative purposes only, and the disclosure of the present invention is not intended to be limited by the following Examples.

EXAMPLE

Preparation of Copolycarbonate

Example 1

(1) Preparation of Bis-(4-(2-(4-Hydroxyphenyl)Propan-2-yl)Phenyl)3,3′-Thiodipropionate

[0050] ##STR00005##

[0051] In a round-bottom flask, 5 g of 3,3′ -thiodipropionic acid was dissolved in 50 ml of methylene chloride solvent, and then 7.47 g of oxalyl chloride and 0.001 g of DMF were added dropwise thereto at room temperature, followed by stirring at room temperature for 4 hours. The solvent was removed using a rotary evaporator to obtain 3,3-thiodipropionic chloride. Thereafter, the obtained 3,3′-thiodipropionic chloride was dissolved in 50 ml of dichloromethane without a purification process, and slowly added to 13.12 g of bisphenol A, 2.3 g of NaOH, and 50 ml of water, followed by stirring at room temperature for 24 hours. 50 ml of HCl was added to terminate the reaction, and the reaction product was washed with water and dichloromethane. A final compound, bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate was obtained in a final yield of 85%.

[0052] .sup.1H-NMR of the compound is shown in FIG. 1.

(2) Preparation of Copolycarbonate Resin

[0053] To a 2-L main reactor equipped with a nitrogen purge device and a condenser and enabling maintenance at room temperature using a circulator, 620 g of water, 116.24 g of BPA, 0.6 g of bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate prepared in (1), 102.5 g of NaOH, and 200 ml of MeCl.sub.2 were injected, followed by stirring for a few minutes.

[0054] After stopping the nitrogen purge, 62 g of triphosgene and 120 g of MeCl.sub.2 were added to a 1-L round-bottom flask to dissolve triphosgene. Then, the dissolved triphosgene solution was slowly injected to the main reactor where the BPA solution was dissolved. After completion of injection, 2.28 g of PTBP(p-tert-butylphenol) was added, followed by stirring for about 10 minutes. After completion of stirring, 97 g of 40%wt NaOH aqueous solution was added and 1.16 g of TEA as a coupling agent was added thereto. At this time, a reaction pH was maintained at 11˜13. After the reaction solution was allowed to stand for a time for sufficient reaction, pH was decreased to 3-4 by addition of HCl to terminate the reaction. After stopping the stirring, a polymer layer and an aqueous layer were separated and then the aqueous layer was removed, and the residue was repeatedly washed with pure H.sub.2O again, and this washing process was repeated 3 to 5 times.

[0055] After completion of washing, only the polymer layer was extracted, and the polymer crystals were obtained by re-precipitation using a non-solvent of methanol, H.sub.2O or the like. In this regard, a weight average molecular weight of the prepared polycarbonate was 31,000 g/mol.

[0056] .sup.1H-NMR of the prepared copolycarbonate is shown in FIG. 2.

Example 2

[0057] A polycarbonate was prepared in the same manner as in Example 1, except that 115.5 g of BPA was used, and 2.4 g of bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate was used.

Example 3

[0058] A polycarbonate was prepared in the same manner as in Example 1, except that 114.2 g of BPA was used, and 5.8 g of bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate was used.

Example 4

[0059] A polycarbonate was prepared in the same manner as in Example 1, except that 111.6 g of BPA was used, and 12.6 g of bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate was used.

Example 5

[0060] A polycarbonate was prepared in the same manner as in Example 1, except that 1.97 g of PTBP was used.

Example 6

[0061] A polycarbonate was prepared in the same manner as in Example 1, except that 3.41 g of

[0062] PTBP was used.

Comparative Example 1

[0063] A polycarbonate was prepared in the same manner as in Example 1, except that 116.47 g of BPA was used without using bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate.

Comparative Example 2

[0064] A polycarbonate was prepared in the same manner as in Example 1, except that 116.47 g of BPA was used and 1.97 g of PTBP was used without using bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′-thiodipropionate.

Comparative Example 3

[0065] A polycarbonate was prepared in the same manner as in Example 1, except that 116.47 g of BPA was used and 3.41 g of PTBP was used without using bis-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl)3,3′ -thiodipropionate.

EXPERIMENTAL EXAMPLE

Evaluation of Physical Properties of Copolycarbonate

[0066] The properties of the extrusion samples of the polycarbonates prepared in Example 1 and Comparative Example 1 were measured by the following method. The results are given in the following Table 1.

[0067] Weight average molecular weight (g/mol): measured by weighing with PC standard using Agilent 1200 series.

[0068] Flowability (MI): measured according to ASTM D1238 (under conditions of 300° C. and 1.2 kg).

[0069] Glass transition temperature (Tg, ° C.): Differential Scanning calorimetry (DSC).

[0070] Impact strength (IMP, J/m): measured according to ASTM D256(⅛ inch, Notched Izod) at 23° C.

[0071] Weather resistance (dYI, 500 time): a change in yellow index (dYI) of the sample was measured using a Zenon Whether 0 meter according to ASTM G155.

TABLE-US-00001 TABLE 1 Molecular weight MI Tg IMP (g/mol) (g/10 min) (° C.) (J/m) DYI Example 1 31,000 12.7 151.1 790 11 Example 2 31,000 15 150.8 782 9 Example 3 31,000 16.2 151.2 766 8 Example 4 31,000 17.5 151.3 746 7 Example 5 34,900 7.2 151.5 852 11 Example 6 24,700 28.6 151.6 641 11 Comparative 31,000 10.8 151 784 24 Example 1 Comparative 34,900 5.7 151.8 870 23 Example 2 Comparative 24,700 26.2 151.2 645 25 Example 3

[0072] Referring to Table 1, it was confirmed that the copolycarbonate prepared in Example 1 has impact strength equivalent to that of a general polycarbonate of Comparative Example 1, and also has very excellent flowability.

[0073] Further, the copolycarbonates of Examples have superior weather resistance which is a property of withstanding various weathers while maintaining the intrinsic physical properties of polycarbonate resin, thereby being easily applied to various fields such as exterior materials of electrical and electronic products, vehicle components, and construction materials.