HIGHLY HEAT-RESISTANT POLYCARBONATE ESTER AND PREPARATION METHOD THEREFOR

Abstract

A heat-resistant, bio-based polycarbonate ester prepared by melt polycondensation of 1,4:3,6-dianhydrohexitol and a carbonate or 1,4-cyclohexanedicarboxylate is disclosed. The heat-resistant, bio-based polycarbonate ester includes a repeat unit 1 of Formula 1, a repeat unit 2 of Formula 2, and a repeat unit 3 of Formula 3. The polycarbonate ester has excellent heat resistance, transparency, and processability. A method of producing the polycarbonate includes a step of melt polycondensation of 1,4:3,6-dianhydrohexitol and a carbonate or 1,4-cyclohexanedicarboxylate.

##STR00001##

Claims

1. A highly heat-resistant, bio-based polycarbonate ester, comprising: a repeat unit 1 of the following Formula 1; a repeat unit 2 of the following Formula 2; and a repeat unit 3 of the following Formula 3: ##STR00013## wherein the repeat unit 3 is obtained from the reaction of 1,4:3,6-dianhydrohexitol and a compound represented by the following Formula 5, ##STR00014##

2. The highly heat-resistant, bio-based polycarbonate ester of claim 1, wherein the compound represented by the Formula 5 is obtained by converting a compound represented by the following Formula 4 to an intermediate reactant having a halogen functional group at the terminal thereof, followed by a nucleophilic reaction with phenol or a phenol substituent, or subjecting a compound represented by the following Formula 4 to a transesterification or esterification reaction with phenol or a phenol substituent; ##STR00015## wherein R.sup.1 is methyl or hydrogen.

3. The highly heat-resistant, bio-based polycarbonate ester of claim 1, wherein the repeat unit 1 is obtained from the reaction of 1,4:3,6-dianhydrohexitol and a compound represented by the following Formula 7, and the repeat unit 2 is obtained from the reaction of 1,4:3,6-dianhydrohexitol and a compound represented by the following Formula 6, ##STR00016## wherein R.sup.2 and R.sup.3 are each an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, wherein the aryl group may have at least one substituent selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 4 to 20 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkoxy group having 4 to 20 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, a cycloalkylsulfonyl group having 4 to 20 carbon atoms, an arylsulfonyl group having 6 to 18 carbon atoms, and an ester substituent.

4. The highly heat-resistant, bio-based polycarbonate ester of claim 1, which is composed of the repeat units 1 to 3, and when the molar fractions of the repeat units 1 to 3 are x, y, and z, respectively, x is a real number of greater than 0 to less than 1, y is a real number of greater than 0 to 0.7, z is a real number of greater than 0 to 0.6, and x+y+z is 1.

5. The highly heat-resistant, bio-based polycarbonate ester of claim 2, wherein the intermediate reactant having a halogen functional group at the terminal thereof is a compound represented by the following Formula 8: ##STR00017## wherein R.sup.4 is each independently F, Cl, or Br.

6. The highly heat-resistant, bio-based polycarbonate ester of claim 5, wherein the molar ratio of the compound represented by the above Formula 8 to phenol or the phenol substituent is 1:1 to 5.

7. The highly heat-resistant, bio-based polycarbonate ester of claim 2, wherein the intermediate reactant having a halogen functional group at the terminal thereof is prepared by reacting the compound represented by the above Formula 4 with a halogenated compound, and the halogenated compound is at least one selected from the group consisting of phosgene, triphosgene, thionyl chloride, oxalyl chloride, phosphorus trichloride, phosphorus pentachloride, phosphorus pentabromide, and cyanuric fluoride.

8. The highly heat-resistant, bio-based polycarbonate ester of claim 3, wherein the compound represented by the above Formula 7 is diphenyl carbonate or substituted diphenyl carbonate.

9. The highly heat-resistant, bio-based polycarbonate ester of claim 3, wherein the highly heat-resistant, bio-based polycarbonate ester further comprises an additional diphenyl ester compound other than the compounds represented by the Formulae 5 and 6, when the molar ratio of the additional diphenyl ester compound is p, the molar ratio of the compounds represented by the above Formulae 5 to 7 employed is to be 1-p, wherein the additional diphenyl ester is prepared by reacting a primary, secondary, or tertiary dicarboxylate or dicarboxylic acid with phenol or a phenol substituent, and the additional diphenyl ester compound is one kind or a mixture of two or more kinds.

10. The highly heat-resistant, bio-based polycarbonate ester of claim 1, which has a glass transition temperature of 160 to 240° C. and a melt flow index of 5 to 150 g/10 min when measured at 260° C. under a load of 2.16 kg.

Description

EXAMPLE

Preparation Example 1: Preparation of DPT from TPA

[0100] A 1-L round-bottom flask equipped with a 4-blade agitator, inlets for phosgene and nitrogen gas, an outlet for gases, and a thermometer was charged with 100 g (0.60 mol) of TPA (SK Chemicals) and 200 g of toluene. The mixture was stirred at room temperature. 1.28 mol of phosgene gas was fed to the flask under atmospheric pressure for 10 hours to carry out the reaction. Thereafter, nitrogen gas was fed to the flask for 2 hours to remove the residual phosgene and hydrochloric acid gas generated as a by-product, thereby yielding a transparent and homogeneous reaction solution. An analysis of the reaction solution by gas chromatography (GC) indicated that the ratio of TPC was 49 wt % and that the reaction yield was 87%.

[0101] Then, 50 wt % of toluene initially supplied was distilled off from the reaction solution under a reduced pressure. Thereafter, a phenol solution in which 121 g (1.28 mol) of phenol was dissolved in 121 g of toluene was added through a dropping funnel to the reaction solution for 2 hours. The mixture was stirred for 1 hour. Upon completion of the reaction, toluene was distilled off from the reaction solution under a reduced pressure. The crude DPT thus obtained was purified by recrystallization. Then, the purified DPT was dried at 90° C. under vacuum for 24 hours to obtain 162 g of DPT. Here, the reaction yield was 85%, and the purity of DPT according to a GC analysis was 99.8%.

Preparation Example 2: Preparation of DPT from TPA

[0102] The procedures of Preparation Example 1 were repeated to prepare DPT, except that 1.27 g (0.017 mol) of dimethyl formamide was employed as an organic catalyst. As a result of synthesis, the reaction yield was 84%, and the purity of DPT according to a GC analysis was 99.7%.

Preparation Example 3: Preparation of DPT from DMT

[0103] A 1-L round-bottom flask equipped with a 4-blade agitator, inlets for phosgene and nitrogen gas, an outlet for gases, and a thermometer was charged with 100 g (0.51 mol) of DMT (SK Chemicals), 2.0 g (0.015 mol) of aluminum chloride, and 200 g of toluene. The mixture was stirred at room temperature. 1.10 mol of phosgene gas was fed to the flask under atmospheric pressure for 10 hours to carry out the reaction. Thereafter, nitrogen gas was fed to the flask for 2 hours to remove the residual phosgene and hydrochloric acid gas generated as a by-product, thereby yielding a transparent and homogeneous reaction solution. An analysis of the reaction solution by gas chromatography (GC) indicated that the ratio of TPC was 48 wt % and that the reaction yield was 89%.

[0104] Then, 50 wt % of toluene initially supplied was distilled off from the reaction solution under a reduced pressure. Thereafter, a phenol solution in which 100 g (1.06 mol) of phenol was dissolved in 100 g of toluene was added through a dropping funnel to the reaction solution for 2 hours. The mixture was stirred for 1 hour. Upon completion of the reaction, toluene was distilled off from the reaction solution under a reduced pressure. The crude DPT thus obtained was purified by recrystallization. Then, the purified DPT was dried at 90° C. under vacuum for 24 hours to obtain 85 g of DPT. Here, the reaction yield of DPT was 87%, and the purity of DPT according to a GC analysis was 99.7%.

Preparation Example 4: Preparation of DPT from TPA

[0105] A 1-L autoclave equipped with a 4-blade agitator, a cooling condenser, and a thermometer was charged with 100 g (0.6 mol) of TPA, 565 g (6 mol) of phenol, and 1.83 g (0.01 mol) of zinc acetate (Zn(OAc).sub.2) as a catalyst. Then, the mixture was heated to 100° C. and stirred, followed by pressurizing to 1 kgf/cm.sup.2 and elevating temperature to carry out the reaction at 200° C. for 10 hours. In such event, water generated as a reaction by-product was discharged from the autoclave. Upon completion of the reaction, excessively added phenol was distilled off under a reduced pressure to thereby finally obtain a solid product containing unreacted materials.

[0106] Then, 136 g of the solid product containing unreacted materials, 282 g of phenol, 400 g of toluene, and 0.92 g of zinc acetate were charged to the autoclave as described above and then stirred at room temperature. Thereafter, the mixture was heated to 100° C. and subjected to the reaction at room temperature for 10 hours. In such event, water generated as a reaction by-product was discharged from the autoclave. Upon completion of the reaction, the reactants were cooled to 50° C. and separated by solid-liquid separation using a filter. Then, toluene was removed from the separated toluene solution using an evaporator, and the crude DPT thus obtained was purified by recrystallization. Thereafter, the purified DPT was dried at 90° C. under vacuum for 24 hours to obtain 80 g of DPT. Here, the reaction yield was 42%.

Preparation Example 5: Preparation of DPT from DMT

[0107] A 1-L autoclave equipped with a 4-blade agitator, a cooling condenser, and a thermometer was charged with 100 g (0.51 mol) of DMT (SK Chemicals), 480 g (5.10 mol) of phenol, and 1.72 g (0.01 mol) of p-toluenesulfonic acid. Then, the mixture was heated to 100° C. and stirred, followed by pressurizing to 1 kgf/cm.sup.2 and elevating temperature to carry out the reaction at 200° C. for 10 hours. In such event, methanol generated as a reaction by-product was discharged from the autoclave. Upon completion of the reaction, excessively added phenol was distilled off under a reduced pressure to thereby finally obtain a solid product containing unreacted materials.

[0108] Then, 140 g of the solid product containing unreacted materials, 240 g of phenol, 400 g of toluene, and 0.86 g of p-toluenesulfonic acid were charged to the autoclave as described above and then stirred at room temperature. Thereafter, the mixture was heated to 100° C. and subjected to the reaction at room temperature for 10 hours. In such event, methanol generated as a reaction by-product was discharged from the autoclave. Upon completion of the reaction, the reactants were cooled to room temperature and separated by solid-liquid separation using a filter. Then, toluene was removed from the separated toluene solution using an evaporator, and the crude DPT thus obtained was purified by recrystallization. Thereafter, the purified DPT was dried at 90° C. under vacuum for 24 hours to obtain 106 g of DPT. Here, the reaction yield was 65%.

Example 1: Preparation of a Highly Heat-Resistant, Bio-Based Polycarbonate Ester

[0109] An 18-L bench-scale reactor for polycondensation was charged with 1,995 g (13.7 mol) of isosorbide (ISB, Roquette Freres), 436 g (1.37 mol) of DPT prepared in Preparation Example 1, 444 g (1.37 mol) of DPCD (SK Chemicals), 2,345 g (10.96 mol) of DPC (Changfeng), and 2 g of a 1% aqueous solution of sodium aluminate (NaAlO.sub.2). The mixture was heated to 150° C. Once the temperature reached 150° C., the pressure was reduced to 400 torr, and the temperature was then elevated to 190° C. over 1 hour. During the temperature elevation, phenol was generated as a by-product of the polymerization reaction. When the temperature reached 190° C., the pressure was reduced to 100 torr and maintained for 20 minutes, and then the temperature was elevated to 230° C. over 20 minutes. Once the temperature reached 230° C., the pressure was reduced to 10 torr, and then the temperature was elevated to 250° C. over 10 minutes. The pressure was reduced to 1 torr or less at 250° C., and the reaction continued until the target stirring torque was reached. Upon arrival at the target stirring torque, the reaction was terminated. The polymerized product was discharged as a strand under a pressure, which was rapidly cooled in a water bath and then cut into pellets. The polycarbonate ester thus prepared had Tg of 168° C. and IV of 0.54 dL/g.

Example 2 to 10: Preparation of a Highly Heat-Resistant, Bio-Based Polycarbonate Ester

[0110] The same procedures as Example 1 were repeated, except that the raw materials for polymers were as described in Table 1 below.

Comparative Example 1: Preparation of a Bio-Based Polycarbonate Ester from CHDM

[0111] The same procedures as Example 1 were repeated to prepare a polycarbonate ester, except that 1,623 g (5.1 mol) of DPT prepared in Preparation Example 1, 2,549 g (11.9 mol) of DPC, 1,988 g (13.6 mol) of ISB, and 490 g (3.4 mol) of 1,4-cyclohexanedimethanol (CHDM, SK Chemicals) were used while DPCD was not used. The polycarbonate ester thus prepared had Tg of 155° C. and IV of 0.55 dL/g.

Comparative Examples 2 and 3

[0112] The same procedures as Comparative Example 1 were repeated to prepare a polycarbonate ester, except that the raw materials for polymers were as described in Table 1 below.

Test Example: Evaluation of Physical Properties

[0113] The polycarbonate esters of Examples 1 to 10 and Comparative Examples 1 to 3 were each evaluated for their physical properties by the following methods. The measured physical properties are shown in Table 1 below.

[0114] Measurement of Glass Transition Temperature (Tg)

[0115] The glass transition temperature was measured using a differential scanning calorimeter (Q20, TA Instruments) in accordance with ASTM D3418.

[0116] Measurement of Light Transmittance (T)

[0117] The light transmittance was measured for a specimen having a thickness of 4 mm using a spectrophotometer (CM-3600A, Konica Minolta) in accordance with ASTM D1003.

[0118] Measurement of Melt Flow Index (MFI)

[0119] The melt flow index was measured using a melt indexer (G-01, TOYOSEIKI) under the conditions of 260° C. and a load of 2.16 kg in accordance with ASTM D1238.

TABLE-US-00001 TABLE 1 Tg T MI ISB CHDM DPC DPCD DPT (° C.) (%) (g/10 min) Ex. 1 1 0 0.8 0.1 0.1 168 92 72 Ex. 2 1 0 0.7 0.2 0.1 164 92 100 Ex. 3 1 0 0.6 0.2 0.2 172 92 71 Ex. 4 1 0 0.5 0.2 0.3 180 91 41 Ex. 5 1 0 0.4 0.3 0.3 178 92 70 Ex. 6 1 0 0.3 0.4 0.3 174 92 99 Ex. 7 1 0 0.2 0.4 0.4 182 91 69 Ex. 8 1 0 0.1 0.4 0.5 190 91 39 Ex. 9 1 0 0.3 0.3 0.4 185 91 42 Ex. 10 1 0 0.2 0.3 0.5 193 90 14 C. Ex. 1 0.8 0.2 0.7 0 0.3 155 90 35 C. Ex. 2 0.8 0.2 0.6 0.1 0.3 152 91 65 C. Ex. 3 0.7 0.3 0.6 0 0.4 154 89 37

[0120] As shown in Table 1 above, the highly heat-resistant, bio-based polycarbonate esters prepared from diphenyl terephthalate (DPT) represented by Formula 5 in Examples 1 to 10 according to the process of the present invention had high glass transition temperatures as compared with the conventional bio-based polycarbonate ester copolymerized from DPC and 1,4-diphenyl-cyclohexanedicarboxylate (DPCD) alone. Thus, the highly heat-resistant, bio-based polycarbonate esters are suitable for applications that require high heat resistance.

[0121] In addition, as the content of the repeat unit of DPCD increases (Examples 1, 2 and 4 to 6), the glass transition temperature is lowered as the content of the aliphatic ring monomer increases. But the melt flow index increases, resulting in an increased flowability.

[0122] Further, it was confirmed that as the content of the repeat unit of DPT increases (Examples 2 to 4 and 6 to 8), the glass transition temperature was elevated whereas the melt flow index was decreased. In particular, in Example 3, the melt flow index is similar even though the glass transition temperature is higher than that of Example 1. In Example 7, the melt flow index is similar even though the glass transition temperature is higher than those of Examples 1 and 3. In addition, in Example 10, the glass transition temperature had the highest value among the Examples, but the melt flow index was relatively low due to the low content of the repeat unit of DPCD.

[0123] In addition, the light transmittance values in Examples 1 to 10 were all 90% or more, which is equal to, or higher than, the maximum light transmittance of 90% of BPA-based polycarbonate products that have the same level of heat resistance. In particular, the light transmittance values in Examples 1 to 9 were more excellent as 91% or higher.

[0124] Meanwhile, the bio-based polycarbonate esters prepared from 1,4-cyclohexanedimethanol (CHDM) in Comparative Examples 1 to 3 had low glass transition temperatures. Thus, they are not suitable for applications that require high heat resistance. The melt flow indices were not high even though the glass transition temperatures were relatively low as compared with the Examples. In particular, in Comparative Example 3, the light transmittance was reduced as the content of the repeat unit of DPT was increased.

[0125] Accordingly, in the process of the present invention, it is possible to control the properties of the bio-based polycarbonate ester attributable to the advantages and disadvantages of the carbonate bond and the ester bond by adjusting their ratios as well as the contents of the repeat units of 1,4-diphenyl-cyclohexanedicarboxylate and diphenyl terephthalate, depending on the target properties of high heat resistance thereof. The highly heat-resistant, bio-based polycarbonate ester prepared by the process is excellent in heat resistance, transparency, and flowability. Thus, they can be advantageously used in various applications that require high heat resistance.