KR20110044685A - Siloxane compound and branched polycarbonate manufactured using the same - Google Patents

Abstract

PURPOSE: A branched polycarbonate prepared using siloxane compounds is provided to improve shock resistance at low temperature. CONSTITUTION: A siloxane compound is denoted by chemical formula 1. In chemical formula 1, R1 is independently hydrogen atom, halogen atom, alkyl group, alkoxy group, or aryl group; and R2 is independently alkylene group or arylene group of 3-8 carbon atoms. A branched polycarbonate contain 0.5-40 weight% of branched structure induced from the siloxane compounds.

Description

Siloxane compound and branched polycarbonate prepared using the same {SILOXANE COMPOUND AND BRANCHED POLYCARBONATE MANUFACTURED USING THE SAME}

The present invention relates to siloxane compounds and branched polycarbonates prepared using the same, and more particularly, to siloxane compounds having three or more hydroxyl groups and branched polycarbonates prepared using the same as a branching agent.

Polycarbonate resins have advantages such as high impact strength, numerical stability and thermal stability that exhibit optical properties, and thus are used for soundproof walls, windows, and lenses requiring low dust pollution for building materials requiring transparency.

In general, polycarbonate resin is prepared by reacting bisphenol A with phosgene, and the glass transition temperature (Tg) is about 155 ° C. Among these polycarbonate resins, the linear polycarbonate has a high impact strength of 90 to 100 kgf · cm / cm at room temperature, while a sharp decrease in impact strength to 10 to 20 kgf · cm / cm at a low temperature around −30 ° C. There is this. For example, low temperature impact resistance is insufficient to be used for automotive plastics and the like exposed to the external environment in cold weather.

In order to improve the low temperature impact resistance of polycarbonate, a polysiloxane-polycarbonate copolymer has been proposed, but the polysiloxane-polycarbonate copolymer has a high melt strength, high shear response, and high melt discharge ratio required for blow molding. There is a problem that does not meet the requirement to have.

In order to solve the above problems, the present invention provides a branched polycarbonate having an improved low temperature impact resistance while having the melting characteristics required for processing such as blow molding.

The present invention provides a siloxane compound having three or more hydroxy groups, which is used as a branching agent to prepare the branched polycarbonate.

The siloxane compound according to the embodiments of the present invention may have Formula 1 below.

[Formula 1]

In Formula 1, R ₁ may independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, R ₂ may independently represent an alkylene group or an arylene group having 3 to 8 carbon atoms, Y ₁ , Y ₂ may each independently represent a hydrogen atom, a hydroxy group, an amine group, a urethane group, an ester group, or an alkoxy group having 1 to 8 carbon atoms, p may represent an integer of 0 to 3, and q is An integer of 0 to 4 may be represented, and D may represent an integer of 1 or more.

The branched polycarbonate according to embodiments of the present invention may include a branched structural unit derived from the siloxane compound of Formula 1.

The branched structural unit may be included in 0.5 to 40% by weight based on the branched polycarbonate.

The molecular weight of the branched polycarbonate may be 15,000 to 150,000.

The branched polycarbonate according to the embodiments of the present invention may be prepared by using a siloxane compound having three or more hydroxyl groups as a branching agent, and thus may have melting properties required for processing such as blow molding while having improved low temperature impact resistance. have.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The objects, features and advantages of the present invention will be readily understood through the following examples. The invention is not limited to the embodiments described herein, but may be embodied in other forms. The embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and the spirit of the present invention may be sufficiently delivered to those skilled in the art. Therefore, the present invention should not be limited by the following examples.

As used herein, the term "reaction product" means a product formed by reacting two or more reactants.

In addition, in the chemical formula described herein, the letter "R" used to represent a hydrogen atom, a halogen atom and / or a hydrocarbon group, etc. has a subscript represented by a number, but "R" is such a subscript. It should not be limited by "R" may independently represent a hydrogen atom, a halogen atom, and / or a hydrocarbon group. For example, even if two or more "Rs" have the same number of subscripts, these "Rs" may represent the same hydrocarbon group or may represent different hydrocarbon groups. In addition, even if two or more "R" have different numbers of subscripts, these "R" may represent the same hydrocarbon group or may represent a different hydrocarbon group.

<Siloxane compound>

The siloxane compound according to the embodiments of the present invention may have Formula 1 below. As shown in the following Formula 1, the siloxane compound may have three or more hydroxyl groups.

[Formula 1]

In Formula 1, R ₁ may independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. For example, the halogen atom may be Cl or Br, and the alkyl group may be a methyl group, ethyl group, propyl group, or butyl group. The alkoxy group may be a methoxy group, an ethoxy group, a propoxy group or a butoxy group, and the aryl group may be a phenyl group, a chlorophenyl group, a phenol group, or a tolyl group. R ₂ may independently represent an alkylene group or an arylene group having 3 to 8 carbon atoms. Y ₁ and Y ₂ may each independently represent a hydrogen atom, a hydroxyl group, an amine group, a urethane group, an ester group, or an alkoxy group having 1 to 8 carbon atoms. p may represent an integer of 0 to 3, q may represent an integer of 0 to 4, and D may represent an integer of 1 or more.

The siloxane compound may be, for example, a compound of the following Chemical Formula 2a and / or 2b having at least one hydroxyl group and a compound of the following Chemical Formula 3 containing silicon at a molar ratio of 2: 1 using a platinum catalyst. Can be prepared synthetically. The compounds of formulas 2a and / or 2b can be prepared using, for example, allyldimethoxybenzene and aluminum powder and iodine.

(2a)

[Formula 2b]

In Formulas 2a and 2b, Y ₁ and Y ₂ may each independently represent a hydrogen atom, a hydroxyl group, an amine group, a urethane group, an ester group, or an alkoxy group having 1 to 8 carbon atoms. p may represent an integer of 0 to 3, q may represent an integer of 0 to 4, and m may represent an integer of 2 to 7.

(3)

In Formula 3, R ₁ may independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group. For example, the halogen atom may be Cl or Br, and the alkyl group may be a methyl group, ethyl group, propyl group, or butyl group. The alkoxy group may be a methoxy group, an ethoxy group, a propoxy group or a butoxy group, and the aryl group may be a phenyl group, a chlorophenyl group, a phenol group, or a tolyl group. D may represent an integer of 1 or more.

<Branched polycarbonate>

Branched polycarbonates according to the present invention can be prepared using the siloxane compound as a branching agent. The branched polycarbonate may include a structure of Formula 4 as a repeating unit.

[Formula 4]

In Formula 4, R ₃ may represent an arylene group, and may be derived from a compound of Formula 5 below.

[Chemical Formula 5]

In Formula 5, X is a straight, branched or cyclic alkylene group having no functional group, or a straight, branched group containing a functional group such as sulfide, ether, sulfoxide, sulfone, ketone, phenyl, isobutylphenyl, naphthyl Or a cyclic alkylene group. Preferably, X may be a straight, branched, or cyclic alkylene group having 1 to 10 carbon atoms. R ₄ and R ₅ may independently represent a hydrogen atom, a halogen atom or a straight, branched or cyclic alkyl group. n and m can represent an integer of 0-4 independently.

The compound of Formula 5 may be, for example, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) naphthylmethane, bis (4-hydroxyphenyl )-(4-isobutylphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1-ethyl-1,1-bis (4-hydroxyphenyl) propane, 1-phenyl-1,1 -Bis (4-hydroxyphenyl) ethane, 1-naphthyl-1,1-bis (4-hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, 1,10-bis ( 4-hydroxyphenyl) decane, 2-methyl-1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy Phenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) nonane, 2,2- Bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 4-methyl-2,2-bis (4-hydroxyphenyl) pentane , 4,4-bis (4-hydroxyphenyl) heptane, diphenyl-bis (4-hydroxyphenyl) Tan, Resorcinol, Hydroquinone, 4,4'-dihydroxyphenyl ether [bis (4-hydroxyphenyl) ether], 4,4'-dihydroxy-2,5- Dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (3,5-dichloro- 4-hydroxyphenyl) ether, 1,4-dihydroxy-2,5-dichlorobenzene, 1,4-dihydroxy-3-methylbenzene, 4,4'-dihydroxydiphenol [p, p '-Dihydroxyphenyl], 3,3'-dichloro-4,4'-dihydroxyphenyl, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5- Dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dichloro-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) Cyclododecane, 1,1-bis (4-hydroxyphenyl) cyclododecane, 1,1-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) decane, 1, 4-bis (4-hydroxyphenyl) propane, 1,4-bis ( 4-hydroxyphenyl) butane, 1,4-bis (4-hydroxyphenyl) isobutane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (3-chloro-4-hydroxy Hydroxyphenyl) propane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, bis (3,5-dichloro-4-hydroxyphenyl) methane, 2,2-bis (3,5-dimethyl-4 -Hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2 , 4-bis (4-hydroxyphenyl) -2-methyl-butane, 4,4'-thiodiphenol [bis (4-hydroxyphenyl) sulfone], bis (3,5-dimethyl-4-hydroxy Phenyl) sulfone, bis (3-chloro-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, bis (3-methyl-4-hydroxyphenyl ) Sulfide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, bis (3,5-dibromo-4-hydroxyphenyl) sulfoxide, 4,4'-dihydroxybenzophenone, 3 , 3 ', 5,5'-tetramethyl-4,4'-dihydroxybenzo It may be a non-4,4'-dihydroxy-diphenyl, methyl hydroquinone, 1,5-dihydroxynaphthalene, and 2,6-dihydroxy naphthalene, but is not limited thereto. Representative of this is 2,2-bis (4-hydroxyphenyl) propane (bisphenol A). Other difunctional phenols may refer to US Patents US 2,999,835, US 3,028,365, US 3,153,008, US 3,334,154, US 4,131,575, and the like. Can be used in combination.

In embodiments of the present invention, the branched polycarbonate may be prepared by adding the branching agent to an oligomeric polycarbonate and reacting. Alternatively, the branched polycarbonate may be prepared by a phosgene method of mixing a phosgene together with the dihydric phenol compound and the branching agent, but is not limited thereto.

The oligomeric polycarbonate may be prepared by adding the dihydric phenol compound to an aqueous alkali solution to make a phenol salt state and then reacting the salt phenols in dichloromethane, which is an organic solvent injected with phosgene gas. For the production of the oligomeric polycarbonate, the molar ratio of phosgene to bisphenol can be maintained in the range of about 1: 1 to 1.5: 1. Preferably, the molar ratio of phosgene to bisphenol may be about 1: 1 to 1.2: 1. The molecular weight of the oligomeric polycarbonate prepared may be 1,000 to 2,000.

The oligomer formation reaction can generally be carried out at a temperature in the range of about 15 to 60 ℃. Alkali metal hydroxides may be introduced into the mixture for pH adjustment of the reaction mixture. The alkali metal hydroxide may be, for example, sodium hydroxide.

The branched polycarbonate can be prepared by adding the branching agent to the organic phase-aqueous mixture comprising the oligomeric polycarbonate, and stepwise introducing a molecular weight regulator and a catalyst.

The amount of branching agent added may be 0.01-15 mol% relative to bisphenol A in polycarbonate. When the content of the branching agent is less than 0.01 mol%, low temperature impact resistance may not be satisfactory, and when the content of the branching agent is more than 15 mol%, transparency may be lowered.

As the molecular weight modifier, a monofunctional compound similar to the monomer used for preparing polycarbonate may be used. Such monofunctional materials include, for example, p-isopropylphenol, p-tert-butylphenol (PTBP), p-cumylphenol, p-isooctylphenol, and p- Phenol-based derivatives or aliphatic alcohols such as isononylphenol. Preferably, p-tert-butylphenol (PTBP) can be used.

As the catalyst, a polymerization catalyst and / or a phase transfer catalyst may be used. The polymerization catalyst may be, for example, triethylamine (TEA), and the phase transfer catalyst may be a compound having Formula 6 below.

[Formula 6]

^{_{(R 6) 4 Q + X}} -

In Formula 6, R ₆ may independently represent an alkyl group having 1 to 10 carbon atoms, Q may represent nitrogen or phosphorus, and X may represent a halogen atom or -OR ₇ . R ₇ may represent a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

The phase transfer catalyst is, for example, [CH ₃ (CH ₂ ) ₃ ] ₄ NX, [CH ₃ (CH ₂ ) ₃ ] ₄ PX, [CH ₃ (CH ₂ ) ₅ ] ₄ NX, [CH ₃ (CH ₂₎ ) ₆ ] ₄ NX, [CH ₃ (CH ₂ ) ₄ ] ₄ NX, CH ₃ [CH ₃ (CH ₂ ) ₃ ] ₃ NX, CH ₃ [CH ₃ (CH ₂ ) ₂ ] ₃ NX. Here, X may be Cl, Br or -OR ₇ . R ₇ may be a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

The content of the phase transfer catalyst is preferably about 0.1 to 10% by weight of the reaction mixture. If the content of the phase transfer catalyst is less than 0.1% by weight, the reactivity may be lowered. If the content of the phase change catalyst is greater than 10% by weight, it may precipitate as a precipitate and transparency may be reduced.

After preparing the branched polycarbonate, the organic phase dispersed in methylene chloride is washed with alkali and then separated. Subsequently, the organic phase is washed with 0.1N hydrochloric acid solution, and then washed twice with distilled water.

When the washing is completed, the concentration of the organic phase dispersed in methylene chloride is constantly adjusted to granulate with a certain amount of secondary distilled water in the range of 70 to 80 ℃. If the temperature of the secondary distilled water is less than 70 ° C, the granulation speed may be excessive, and the granulation time may be excessively exceeded. If it is more than 80 ° C, it is difficult to obtain a polycarbonate having a constant particle size. When the assembly is completed, it is preferable to dry for 5 to 10 hours at 100 to 110 ° C first, and 5 to 10 hours at 110 to 120 ° C secondly.

The viscosity average molecular weight of the branched polycarbonate may be 15,000 to 150,000. If the viscosity average molecular weight is less than 15,000, mechanical properties may be significantly lowered. If the viscosity average molecular weight is more than 150,000, there is a problem in processing of the resin due to an increase in melt viscosity.

Example

<Production of siloxane compound>

Example 1

A condenser was placed in a 100 ml three-necked flask, and 4.5 g (0.03 mol) of 4-allylbenzene-1,2-diol and 8.83 g of polydimethylsiloxane were placed under a nitrogen atmosphere. (0.015 mol) was dissolved in 50 ml of chlorobenzene. After completely dissolved, 0.03 g (0.00364 mmol) of a platinum catalyst (platinum (0) -1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex) was added thereto and refluxed for 24 hours. After removing the solvent of the reacted solution, it was washed with distilled water. As a result, a siloxane compound of Formula 7 was prepared.

[Formula 7]

<Production of Branched Polycarbonate>

Example 2

In a 1 L three-necked flask, 60 g (0.263 mol) of bisphenol A was dissolved in 330 ml (18.46 g, 0.462 mol) of 5.6 wt% aqueous sodium hydroxide solution, and then 26.0 g (0.263 mol) of phosgene was collected in methylene chloride and teflon tube (20 m). The reaction was carried out slowly through. The external temperature was kept at 0 ° C. The reactant passed through the tubular reactor was subjected to an interfacial reaction in a nitrogen environment for about 10 minutes to prepare an oligomeric polycarbonate having a viscosity average molecular weight of about 1,000. 215 ml of the organic phase and 322 ml of an aqueous phase were collected from the mixture containing the oligomeric polycarbonate prepared above, and 0.231 g (0.263 mmol, 0.1 mol% of bisphenol A) of the compound of Chemical Formula 7 prepared in Example 1, 1.383 g of p-tert-butylphenol (PTBP) (9.21 mmol, 3.5 mol% for bisphenol A), 0.731 g of tetrabutyl ammonium chloride (TBACl) (2.63 mmol, 1 mol% for bisphenol A), 15 0.1 ml of weight-% triethylamine (TEA) was mixed and reacted for 30 minutes. After separation of the layers, only the organic phase was collected, and the reaction was carried out for 1 hour by mixing 283 g of methylene chloride, 110 mL of 1.1N aqueous sodium hydroxide solution (20% by volume based on the total mixture), and 15 µl of 15% by weight triethylamine. After addition, 167 µl of 15% by weight triethylamine and 128 g of methylene chloride were added thereto, and the mixture was further reacted for 1 hour. The organic phase whose viscosity increased after layer separation was separated after washing with alkali by adding pure water. Subsequently, the organic phase was washed with 0.1N hydrochloric acid solution and then repeatedly washed 2-3 times with distilled water. The washing was completed and the concentration of the organic phase was assembled at a constant amount of 76 ° C. with a certain amount of secondary distilled water. After the granulation was completed, it was first dried at 110 ° C. for 8 hours and secondly at 120 ° C. for 10 hours. This produced a branched polycarbonate. The physical properties of the prepared branched polycarbonate were measured and the results are shown in Table 1 below.

Example 3

In the same manner as in Example 2, a branched polycarbonate was prepared using 0.463 g (0.526 mmol, 0.2 mol% of bisphenol A) of the siloxane compound of Formula 7 prepared in Example 1 as a branching agent. The physical properties of the prepared branched polycarbonate were measured and the results are shown in Table 1 below.

Example 4

In the same manner as in Example 2, a branched polycarbonate was prepared using 0.694 g (0.789 mmol, 0.3 mol% of bisphenol A) of the siloxane compound of Formula 7 prepared in Example 1 as a branching agent. The physical properties of the prepared branched polycarbonate were measured and the results are shown in Table 1 below.

Example 5

In the same manner as in Example 2, a branched polycarbonate was prepared using 0.926 g (1.052 mmol, 0.4 mol% of bisphenol A) of the siloxane compound prepared in Example 1 as a branching agent. The physical properties of the prepared branched polycarbonate were measured and the results are shown in Table 1 below.

Example 6

In a 1 L three-necked flask, 60 g (0.263 mol) of bisphenol A was dissolved in 330 ml (18.46 g, 0.462 mol) of 5.6 wt% aqueous sodium hydroxide solution, and then 26.0 g (0.263 mol) of phosgene was collected in methylene chloride and teflon tube (20 m). The reaction was carried out slowly through. The external temperature was kept at 0 ° C. The reactant passed through the tubular reactor was subjected to an interfacial reaction in a nitrogen environment for about 10 minutes to prepare an oligomeric polycarbonate having a viscosity average molecular weight of about 1,000. 215 ml of the organic phase and 322 ml of an aqueous phase were collected from the mixture containing the oligomeric polycarbonate prepared above, and 0.463 g (0.526 mmol, 0.2 mol% of bisphenol A) of the compound of Formula 7 prepared in Example 1, 0.790 g of p-tert-butylphenol (PTBP) (5.26 mmol, 2.0 mol% for bisphenol A), 0.731 g of tetrabutyl ammonium chloride (TBACl) (2.63 mmol, 1 mol% for bisphenol A), 15 0.1 ml of weight-% triethylamine (TEA) was mixed and reacted for 30 minutes. After separation of the layers, only the organic phase was collected and reacted for 1 hour by mixing 283 g of methylene chloride, 110 ml of 0.52N sodium hydroxide solution (20% by volume based on the total mixture), and 15 µl of 15% by weight triethylamine. After addition, 167 µl of 15% by weight triethylamine and 128 g of methylene chloride were added thereto, and the mixture was further reacted for 1 hour. The organic phase whose viscosity increased after layer separation was separated after washing with alkali by adding pure water. Subsequently, the organic phase was washed with 0.1N hydrochloric acid solution and then repeatedly washed 2-3 times with distilled water. The washing was completed and the concentration of the organic phase was assembled at a constant amount of 76 ° C. with a certain amount of secondary distilled water. After the granulation was completed, it was first dried at 110 ° C. for 8 hours and secondly at 120 ° C. for 10 hours. This produced a branched polycarbonate. The physical properties of the prepared branched polycarbonate were measured and the results are shown in Table 1 below.

Example 7

In the same manner as in Example 6, a branched polycarbonate was prepared using 0.395 g (2.62 mmol, 1.0 mol% of bisphenol A) as a molecular weight modifier and 110 mL of 0.81 N sodium hydroxide aqueous solution. Was prepared. The physical properties of the prepared branched polycarbonate were measured and the results are shown in Table 1 below.

Comparative Example 1

Linear polycarbonates were prepared by interfacial polymerization without the addition of branching agents. The physical properties of the prepared linear polycarbonate were measured, and the results are shown in Table 1 below.

Comparative Example 2

The physical properties of the commercialized polycarbonate (Sabic EXL 1414) were measured and described in Table 1 below.

Comparative Example 3

The physical properties of the commercially available branched polycarbonate (Samyang's TRIREX 3026B) were measured and described in Table 1 below.

Table 1 below shows the physical properties measured after drying the polycarbonate prepared according to Examples 2 to 7 and Comparative Examples 1 to 3 for 24 hours at 130 ℃. The measuring method of the said physical property value is as follows.

(a) H-NMR (nuclear magnetic resonance spectroscopy): Measured using a Bruker Avance DRX 300. The peak of the methyl group of dimethylsiloxane observed at 0.2 ppm by H-NMR and the hydrogen peak at the carbon next to the benzene ring of the silicone branching agent observed at 2.6 ppm and the benzene ring of the silicone branching agent observed at 3.9 ppm It was confirmed that the branched polycarbonate was synthesized by the peak of the methoxy group.

(b) Viscosity Average Molecular Weight: The viscosity of the methylene chloride solution was measured at 20 ° C. using an Ubbelohde Viscometer, and the ultimate viscosity [η] was calculated from the following equation.

[η] = 1.23 × 10 ^-5 Mv ^0.83

(c) Impact strength: Impact strength was measured at room temperature and -50 ℃ using an impact tester (RESIL IMPACTOR, CEAST).

(d) Shear Response: MIR was measured at 260 ° C. based on ASTM D 1238.

division Example Comparative example 2 3 4 5 6 7 One 2 3 Siloxane content
(mol% / BPA) 0.1 0.2 0.3 0.4 0.2 0.2 0 0.23 0 Viscosity Average Molecular Weight
(Mv) 21,000 20,500 20,300 19,500 45,000 100,000 21,000 21,000 22,000 Impact strength
(kgcm / cm) Room temperature 74-78 75-80 74-80 75-80 95-100 110-115 74-78 75-80 75-80 -50 ℃ 60-63 62-64 62-64 63-66 65-68 75-80 14-19 60-65 15-20 Glass transition temperature
(℃) 150-153 147-151 140-145 135-140 155-160 158-163 154-158 145-150 155-160 MIR 20-21 30-34 37-40 41-43 11-13 3 to 4 13-15 8 ~ 10 2 ~ 3

As shown in Table 1, the branched polycarbonates prepared according to Examples 2 to 7 have a glass transition temperature similar to that of linear polycarbonates while having a high MIR value at a similar molecular weight as that of the polycarbonates of Comparative Examples 1 to 3. It can be seen that. Therefore, the branched polycarbonate according to the embodiments of the present invention may have a melting characteristic required for processing such as blow molding while having high low temperature impact resistance.

Hereinafter, specific embodiments of the present invention have been described. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (4)

The siloxane compound of Formula 1 below.
[Formula 1]

(In Formula 1, R ₁ independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, R ₂ independently represents an alkylene group or an arylene group having 3 to 8 carbon atoms, Y ₁ , Y ₂ each independently represents a hydrogen atom, a hydroxyl group, an amine group, a urethane group, an ester group, or an alkoxy group having 1 to 8 carbon atoms, p represents an integer of 0 to 3, and q represents an integer of 0 to 4 , D represents an integer of 1 or more.) A branched polycarbonate comprising a branched structural unit derived from the siloxane compound of claim 1. The method of claim 2,
The branched structural unit is a branched polycarbonate, characterized in that it comprises 0.5 to 40% by weight relative to the branched polycarbonate. The method of claim 2,
The branched polycarbonate has a molecular weight of 15,000 to 150,000.