WO2013066000A1

WO2013066000A1 - Polycarbonate resin composition having improved low-temperature impact resistance and method of manufacturing the same

Info

Publication number: WO2013066000A1
Application number: PCT/KR2012/008834
Authority: WO
Inventors: Yun Ju Chang; Kyung Moo Shin; Hong Chol RHEE; Jae Hyun Kim; Sun Chul JIN
Original assignee: Samyang Corporation
Priority date: 2011-10-31
Filing date: 2012-10-26
Publication date: 2013-05-10
Also published as: KR20130047332A; KR101448058B1; TW201323519A

Abstract

The present invention relates to a polycarbonate resin composition and a method of manufacturing the same. More specifically, the present invention relates to a polycarbonate resin composition that comprises a polysiloxane-polycarbonate copolymer with high siloxane content and a polycarbonate in an appropriate mixing ratio, and thus has improved low-temperature impact resistance, flowability and heat resistance; and a method of manufacturing the same.

Description

POLYCARBONATE RESIN COMPOSITION HAVING IMPROVED LOW-TEMPERATURE IMPACT RESISTANCE AND METHOD OF MANUFACTURING THE SAME

Polycarbonate has good mechanical properties such as tensile strength, impact resistance, etc. and also has good dimensional stability, heat resistance and optical transparency. Thus, it has been extensively used in many industries. However, although polycarbonate has good impact resistance at room temperature, its impact resistance rapidly becomes worse at low temperature.

To improve such a disadvantage, various copolymers have been researched and it has been known that polysiloxane-polycarbonate copolymer has relatively good impact resistance at low temperature. However, polysiloxane-polycarbonate copolymers that are currently used conventionally do not show industrially satisfactory low-temperature impact resistance. In addition, they often cause deterioration in other physical properties such as flowability, heat resistance, etc.

Accordingly, there is a need to develop a polycarbonate resin composition which can show significantly improved low-temperature impact resistance while maintaining good inherent physical properties of polycarbonate, such as flowability, heat resistance, etc.

[Prior Art Document]

US 2003/0105226 A

The present invention is intended to solve the problems involved in the prior arts as stated above. The technical purpose of the present invention is to provide a polycarbonate resin composition which shows significantly improved low-temperature impact resistance while maintaining good flowability and heat resistance.

The present invention provides a polycarbonate resin composition comprising a polysiloxane-polycarbonate copolymer and a polycarbonate, wherein the amount of siloxane in the polysiloxane-polycarbonate copolymer is 10 to 35% by weight.

In another aspect, the present invention provides a method for preparing the polycarbonate resin composition, the method comprising: a step of reacting hydroxy-terminated siloxane and oligomeric polycarbonate under an interfacial reaction condition to form a polysiloxane-polycarbonate intermediate; a step of polymerizing the intermediate by using a first polymerization catalyst to prepare a polysiloxane-polycarbonate copolymer having a siloxane amount of 10 to 35% by weight; and a step of mixing the prepared polysiloxane-polycarbonate copolymer and a polycarbonate.

By comprising a polysiloxane-polycarbonate copolymer with specific siloxane content and a polycarbonate, the polycarbonate resin composition according to the present invention can improve low-temperature impact resistance significantly while securing good impact resistance at room temperature, flowability and heat resistance, and thus can be used properly in various applications such as helmet, automobile parts, cell phone housing, etc.

Hereinafter, the present invention will be described more specifically. The purpose, features and advantages of the present invention will be easily understood through the following embodiments. The present invention is not limited to the embodiments as explained herein and may be manifested in other forms. The embodiments introduced herein are provided in order to make the disclosed contents thorough and complete, and to convey the spirit of the present invention sufficiently to a person skilled in the art. Thus, the present invention is not limited to the following embodiments.

The term “reaction product” as used herein means a substance that is formed by reacting two or more reactants.

In addition, although the terms “first,” “second” and the like are used herein for the description of polymerization catalysts, the polymerization catalysts are not limited by these terms. These terms are just used to distinguish the polymerization catalysts from each other. For example, a first polymerization catalyst and a second polymerization catalyst may be of the same kind of catalyst or different kinds of catalyst.

Furthermore, in the chemical formulas described herein, although the English character “R” used for representing hydrogen, halogen atom and/or hydrocarbon group, etc. has a numerical subscript, “R” is not limited by such a subscript. “R” independently represents hydrogen, halogen atom and/or hydrocarbon group, etc. For example, even if two or more “R”s have the same numerical subscript, such “R”s may represent the same hydrocarbon group or different hydrocarbon groups. Also, even if two or more “R”s have different numerical subscripts, such “R”s may represent the same hydrocarbon group or different hydrocarbon groups.

[Polycarbonate resin composition]

The polycarbonate resin composition according to the present invention comprises a polysiloxane-polycarbonate copolymer and a polycarbonate, wherein the amount of siloxane in the polysiloxane-polycarbonate copolymer is 10 to 35% by weight.

Polysiloxane-polycarbonate copolymer (Si-PC)

The polysiloxane-polycarbonate copolymer comprised in the polycarbonate resin composition of the present invention may comprise, as repeating units, a hydroxy-terminated siloxane of the following chemical formula 1a or chemical formula 1; and a polycarbonate block of the following chemical formula 4:

[Chemical formula 1a]

In the above chemical formula 1a,

R₁ independently represents hydrogen atom, halogen atom, hydroxy group, or alkyl group, alkoxy group or aryl group having 1 to 20 carbon atoms. For example, the halogen atom may be Cl or Br, and the alkyl group may be an alkyl group having 1 to 13 carbon atoms such as methyl, ethyl or propyl group. In addition, for example, the alkoxy group may be an alkoxy group having 1 to 13 carbon atoms such as methoxy, ethoxy or propoxy group, and the aryl group may be an aryl group having 6 to 10 carbon atoms such as phenyl, chlorophenyl or tolyl group.

R₂ independently represents hydrocarbon group having 1 to 13 carbon atoms or hydroxy group. For example, R₂ may be alkyl or alkoxy group having 1 to 13 carbon atoms, alkenyl or alkenyloxy group having 2 to 13 carbon atoms, cycloalkyl or cycloalkoxy group having 3 to 6 carbon atoms, aryloxy group having 6 to 10 carbon atoms, aralkyl or aralkoxy group having 7 to 13 carbon atoms, or alkaryl or alkaryloxy group having 7 to 13 carbon atoms.

R₃ independently represents alkylene group having 2 to 8 carbon atoms.

The subscript “m” independently represents an integer of 0 to 4.

The subscript “n” independently represents an integer of 2 to 1,000, preferably 2 to 500, and more preferably 5 to 100.

In one embodiment, as a hydroxy-terminated siloxane of chemical formula 1a, a siloxane monomer available from Dow Corning (

) may be used, but it is not limited thereto.

[Chemical formula 1]

In the above chemical formula 1, R₁, R₂, R₃, m and n are the same as defined in chemical formula 1a above, and “A” represents a structure of the following chemical formula 2 or 3.

[Chemical formula 2]

In the above chemical formula 2,

X represents Y or NH-Y-NH, wherein Y represents linear or branched aliphatic group having 1 to 20 carbon atoms, cycloalkylene group (for example, cycloalkylene group having 3 to 6 carbon atoms), or mono- or polycyclic arylene group having 6 to 30 carbon atoms and being unsubstituted or substituted with halogen atom, alkyl group, alkoxy group, aryl group or carboxyl group. For example, Y may be an aliphatic group that is unsubstituted or substituted with halogen atom, an aliphatic group that contains oxygen, nitrogen or sulfur atom in its main chain, or an arylene group that can be derived from bisphenol A, resorcinol, hydroquinone or diphenylphenol. Y can be represented, for example, by one of the following chemical formulas 2a to 2h.

[Chemical formula 2a]

[Chemical formula 2b]

[Chemical formula 2c]

[Chemical formula 2d]

[Chemical formula 2e]

[Chemical formula 2f]

[Chemical formula 2g]

[Chemical formula 2h]

[Chemical formula 3]

In the above chemical formula 3,

R₄ represents an aromatic hydrocarbon group or aromatic/aliphatic mixed-type hydrocarbon group having 6 to 30 carbon atoms, or an aliphatic hydrocarbon group having 1 to 20 carbon atoms. R₄ may have a structure containing halogen, oxygen, nitrogen or sulfur as well as carbon atom(s). For example, R₄ may be phenyl, chlorophenyl or tolyl (preferably, phenyl).

In one embodiment, the hydroxy-terminated siloxane of chemical formula 1 may be a reaction product of a hydroxy-terminated siloxane of the above chemical formula 1a and an acyl compound.

The acyl compound may have, for example, an aromatic structure, an aliphatic structure, or a mixed type structure comprising both aromatic and aliphatic forms. When the acyl compound is of an aromatic structure or a mixed type structure, it can have 6 to 30 carbon atoms, and when the acyl compound is of an aliphatic structure, it can have 1 to 20 carbon atoms. The acyl compound may further comprise halogen, oxygen, nitrogen or sulfur atom.

In another embodiment, the hydroxy-terminated siloxane of the above chemical formula 1 may be a reaction product of a hydroxy-terminated siloxane of the above chemical formula 1a and a diisocyanate compound.

The diisocyanate compound may be, for example, 1,4-phenylenediisocyanate, 1,3-phenylenediisocyanate or 4,4'-methylenediphenyl diisocyanate.

In another embodiment, the hydroxy-terminated siloxane of the above chemical formula 1 may be a reaction product of a hydroxy-terminated siloxane of the above chemical formula 1a and a phosphor-containing compound (an aromatic or an aliphatic phosphate compound).

The phosphor-containing compound may have a structure of the following chemical formula 1b.

[Chemical formula 1b]

In the above chemical formula 1b, R₄ is the same as defined in chemical formula 3 above, and Z independently represents phosphorus, halogen atom, hydroxyl group, carboxyl group, alkyl group (having 1 to 20 carbon atoms), alkoxy group or aryl group.

Preferably, the polysiloxane-polycarbonate copolymer comprises, as repeating units, a hydroxy-terminated siloxane of the above chemical formula 1a or chemical formula 1; and a polycarbonate block of the following chemical formula 4:

[Chemical formula 4]

In the above chemical formula 4,

R₅ represents aromatic hydrocarbon group having 6 to 30 carbon atoms that is unsubstituted or substituted with alkyl group having 1 to 20 carbon atoms (for example, alkyl group having 1 to 13 carbon atoms), cycloalkyl group (for example, cycloalkyl group having 3 to 6 carbon atoms), alkenyl group (for example, alkenyl group having 2 to 13 carbon atoms), alkoxy group (for example, alkoxy group having 1 to 13 carbon atoms), halogen atom or nitro.

The aromatic hydrocarbon group may be derived from a compound of the following chemical formula 4a.

[Chemical formula 4a]

In the above chemical formula 4a,

X represents alkylene group; linear, branched or cyclic alkylene group having no functional group; or linear, branched or cyclic alkylene group comprising a functional group such as sulfide, ether, sulfoxide, sulfone, ketone, naphthyl, isobutylphenyl, etc. Preferably, X may be linear or branched alkylene group having 1 to 10 carbon atoms, or cyclic alkylene group having 3 to 6 carbon atoms.

R₆ independently represents hydrogen atom, halogen atom or alkyl group―for example, linear or branched alkyl group having 1 to 20 carbon atoms, or cyclic alkyl group having 3 to 20 (preferably, 3 to 6) carbon atoms.

The subscripts “n” and “m” independently represent an integer of 0 to 4.

The compound of the above chemical formula 4a 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-hydroxyphenyl)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)methane, 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-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-hydroxyphenyl)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'-dihydroxybenzophenone, 4,4'-dihydroxy diphenyl, methylhydroquinone, 1,5-dihydroxynaphthalene, or 2,6-dihydroxynaphthalene, but it is not limited thereto. Among them, the representative one is 2,2-bis(4-hydroxyphenyl)propane (bisphenol A). For other functional dihydric phenols, US Patent Nos. 2,999,835; 3,028,365; 3,153,008 and 3,334,154 may be referred to. The above dihydric phenol may be used alone or in combination of two or more of them.

In case of carbonate precursor, for example, carbonyl chloride (phosgene), carbonyl bromide, bis halo formate, diphenylcarbonate, dimethylcarbonate, etc. may be used as another monomer of the polycarbonate resin, but it is not limited thereto.

In the polycarbonate resin composition of the present invention, the amount of siloxane in the polysiloxane-polycarbonate copolymer is 10 to 35% by weight, preferably 15 to 30% by weight, and more preferably 20 to 30% by weight. If the amount of siloxane is less than 10% by weight based on total weight of the copolymer, the effect of improving low-temperature impact resistance may be insufficient as compared with the requirement of the present invention. If the amount of siloxane is greater than 35% by weight, the relative amount of polycarbonate in the copolymer decreases and thus physical properties such as flowability, heat resistance, impact resistance at room temperature, transparency, etc. may be deteriorated.

Preferably, the polysiloxane-polycarbonate copolymer may have a viscosity average molecular weight (M_v) of from 10,000 to 70,000, and more preferably from 15,000 to 30,000. If the viscosity average molecular weight of the copolymer is less than 10,000, its mechanical properties may be deteriorated severely. If the viscosity average molecular weight is greater than 70,000, the melt viscosity increases and thus there may be a problem in resin processing.

Polycarbonate (PC)

There is no special limitation to the polycarbonate which is comprised in the polycarbonate resin composition of the present invention together with the polysiloxane-polycarbonate copolymer. Any conventional polycarbonate resin may be used.

Preferably, the polycarbonate has a viscosity average molecular weight of from 10,000 to 50,000, and more preferably 15,000 to 35,000. If the viscosity average molecular weight of the polycarbonate is less than 10,000, its mechanical properties may be deteriorated severely. If the viscosity average molecular weight is greater than 50,000, the flowability decreases and thus there may be a problem in resin processing.

The weight ratio of polysiloxane-polycarbonate copolymer : polycarbonate in the polycarbonate resin composition of the present invention is preferably 10 : 90 to 50 : 50, and more preferably 15 : 85 to 40 : 60. If the weight ratio of the copolymer to the polycarbonate is less than 10 : 90, the effect of improving low-temperature impact resistance may be insufficient as compared with the requirement of the present invention. If the weight ratio is greater than 50 : 50, physical properties such as flowability, heat resistance, impact resistance at room temperature, transparency, etc. may be deteriorated.

The amount of siloxane in the present polycarbonate resin composition comprising a polysiloxane-polycarbonate copolymer and a polycarbonate together is preferably from 3 to 12% by weight, and more preferably from 4 to 10% by weight. When the amount of siloxane in the total composition is within a range of from 3 to 12% by weight, the low-temperature impact resistance can be improved significantly (more than two-fold) while securing good flowability and impact resistance at room temperature.

[Method for preparing the polycarbonate resin composition]

The polycarbonate resin composition of the present invention may be prepared through the steps of: reacting hydroxy-terminated siloxane and oligomeric polycarbonate under an interfacial reaction condition consisting of an aqueous alkaline solution and an organic phase to form a polysiloxane-polycarbonate intermediate; polymerizing the intermediate by using a first polymerization catalyst to prepare a polysiloxane-polycarbonate copolymer; and mixing the prepared polysiloxane-polycarbonate copolymer and a polycarbonate.

In a preferred embodiment, the step for forming the intermediate may comprise a step of mixing the hydroxy-terminated siloxane and the oligomeric polycarbonate in a weight ratio of 10 : 90 to 35 : 65 (more preferably, 15 : 85 to 30 : 70). If the mixing ratio of hydroxy-terminated siloxane is less than 10, the effect of improving low-temperature impact resistance may be insufficient as compared with the requirement of the present invention. If the mixing ratio of hydroxy-terminated siloxane is greater than 35, the relative amount of polycarbonate in the copolymer decreases and thus physical properties such as flowability, heat resistance, impact resistance at room temperature, transparency, etc. may be deteriorated.

The polycarbonate used in the preparation of the polysiloxane-polycarbonate copolymer may be an oligomeric polycarbonate having a viscosity average molecular weight of from 800 to 20,000 (more preferably, from 1,000 to 15,000). If the viscosity average molecular weight of the oligomeric polycarbonate is less than 800, the molecular weight distribution may broaden and physical properties may be deteriorated. If the viscosity average molecular weight of the oligomeric polycarbonate is greater than 20,000, the reactivity may be lowered.

In one embodiment, the oligomeric polycarbonate may be prepared by adding the above-explained dihydric phenol compound in an aqueous alkaline solution to make it in a phenol salt state, and then adding the phenol compound in a phenol salt state to dichloromethane containing injected phosgene gas for reaction. To prepare the oligomer, it is preferable to maintain the molar ratio of phosgene to bisphenol within a range of about 1 : 1 to 1.5 : 1, and more preferably 1 : 1 to 1.2 : 1. If the molar ratio of phosgene to bisphenol is less than 1, the reactivity may be lowered. If the molar ratio of phosgene to bisphenol is greater than 1.5, the molecular weight increases excessively and thus the processability may be lowered.

The above reaction of forming an oligomer may generally be conducted at a temperature range of about 15 to 60°C. In order to adjust pH of the reaction mixture, alkali metal hydroxide (for example, sodium hydroxide) may be used.

In an embodiment, the step for forming the intermediate comprises a step of forming a mixture comprising the hydroxy-terminated siloxane and the oligomeric polycarbonate, wherein the mixture may further comprise a phase transfer catalyst, a molecular weight-controlling agent and a second polymerization catalyst. In addition, the step for forming the intermediate may comprise a step of forming a mixture comprising the hydroxy-terminated siloxane and the oligomeric polycarbonate; and after the reaction of the hydroxy-terminated siloxane and the oligomeric polycarbonate is completed, a step of extracting an organic phase from the resulting mixture, wherein the step of polymerizing the intermediate may comprise a step of providing the first polymerization catalyst to the extracted organic phase.

Concretely, the polysiloxane-polycarbonate copolymer may be prepared by adding the hydroxy-terminated siloxane of the above chemical formula 1a or chemical formula 1 to a mixture of organic phase/aqueous phase containing the polycarbonate, and subsequently feeding a molecular weight-controlling agent and a catalyst.

As the molecular weight-controlling agent, a monofunctional compound similar to a monomer used in preparation of polycarbonate may be used. The monofunctional compound may be, for example, a derivative based on phenol such as p-isopropylphenol, p-tert-butylphenol (PTBP), p-cumylphenol, p-isooctylphenol and p-isononylphenol, or an aliphatic alcohol. Preferably, p-tert-butylphenol (PTBP) may 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 of the following chemical formula 5.

[Chemical formula 5]

(R₇)₄Q⁺X^-

In the above chemical formula 5,

R₇ represents alkyl group having 1 to 10 carbon atoms,

Q represents nitrogen or phosphorus, and

X represents halogen atom or -OR₈ wherein R₈ represents hydrogen atom, alkyl group having 1 to 18 carbon atoms or aryl group having 6 to 18 carbon atoms.

Concretely, the phase transfer catalyst may be, for example, [CH₃(CH₂)₃]₄NX, [CH₃(CH₂)₃]₄PX, [CH₃(CH₂)₅]₄NX, [CH₃(CH₂)₆]₄NX, [CH₃(CH₂)₄]₄NX, CH₃[CH₃(CH₂)₃]₃NX or CH₃[CH₃(CH₂)₂]₃NX, wherein X represents Cl, Br or -OR₈ where R₈ represents hydrogen atom, alkyl group having 1 to 18 carbon atoms or aryl group having 6 to 18 carbon atoms.

The amount of the phase transfer catalyst is preferably about 0.01 to 10% by weight, and more preferably 0.1 to 10% by weight based on total weight of the hydroxy-terminated siloxane and the oligomeric polycarbonate. If the amount of the phase transfer catalyst is less than 0.01% by weight, the reactivity may be lowered. If the amount of the phase transfer catalyst is greater than 10% by weight, precipitation may happen or the transparency may be deteriorated.

In one embodiment, after the polysiloxane-polycarbonate copolymer is prepared, the organic phase dispersed in methylene chloride is washed with alkali and then separated. Subsequently, the organic phase is washed with 0.1 N solution of hydrochloric acid and then rinsed with distilled water 2 or 3 times. After rinsing is completed, the concentration of the organic phase dispersed in methylene chloride is adjusted constantly and granulation is conducted by using a constant amount of pure water at 30 to 100°C, preferably 60 to 80°C. If the temperature of the pure water is lower than 30°C, the granulation rate is low and thus the granulation time may be too long. If the temperature of the pure water is higher than 100°C, it may be difficult to obtain the polycarbonate in uniformly sized morphology. After granulation is completed, it is preferable to dry the product at 100 to 120°C for 5 to 10 hours. More preferably, the product is dried at 100 to 110°C for 5 to 10 hours first, and then at 110 to 120°C for 5 to 10 hours.

The method of mixing the polysiloxane-polycarbonate copolymer and the polycarbonate prepared as such is not especially limited. Preferably, the polysiloxane-polycarbonate copolymer and the polycarbonate are mixed in a weight ratio of 10 : 90 to 50 : 50 to finally prepare the polycarbonate resin composition of the present invention.

Examples and Comparative Examples

Example 1

0.0666 mol of monomer (BY16-799, Dow Corning) was dissolved in 100mL of benzene under nitrogen condition, and 6.66 mmol of 1,4-diazabicyclo[2,2,2]-octane was added thereto. Under refluxing of the resulting solution, 0.0333 mol of 4,4-methylene bis(phenyl isocynate) dissolved in 200mL of benzene was slowly added thereto for 1 hour. The resulting solution was refluxed for 12 hours. After the reaction was completed, the solvent was removed from the solution, and the resulting product was dissolved in acetone, washed with hot distilled water, and dried for 24 hours in a vacuum oven to prepare hydroxy-terminated siloxane having urethane linkage of the following chemical formula 6. The synthesis was confirmed by H-NMR analysis wherein the peak of hydrogen atom that is bonded to the first carbon atom of the aliphatic chain adjacent to the terminal phenyl group in the following chemical formula 6 was observed at 2.75ppm.

[Chemical formula 6]

An interfacial reaction of bisphenol A in an aqueous solution phase and phosgene gas was conducted in the presence of methylene chloride to prepare 400mL of an oligomeric polycarbonate mixture having a viscosity average molecular weight of about 1,000. To the obtained oligomeric polycarbonate mixture, 20% by weight of the hydroxy-terminated siloxane having urethane linkage of chemical formula 6 dissolved in methylene chloride, 1.8mL of tetrabutylammonium chloride (TBACl), 1.5g of p-tert-butylphenol (PTBP) and 275μl of triethylamine (TEA, 15 wt% solution) were admixed and reacted for 30 minutes. The reacted oligomeric polycarbonate mixture was kept for phase separation. After the phases were separated, only the organic phase was collected and thereto 170g of an aqueous solution of sodium hydroxide, 370g of methylene chloride and 300μl of triethylamine (15 wt% solution) were admixed and reacted for 2 hours. After phase separation, the viscosity-increased organic phase was washed with alkali and separated. Next, the resulting organic phase was washed with 0.1N hydrochloric acid solution and then rinsed with distilled water 2 to 3 times. After rinsing was completed, the concentration of the organic phase was adjusted constantly and then granulation was conducted by using a constant amount of pure water at 76°C. After granulation was completed, the product was dried first at 110°C for 8 hours, and second at 120°C for 10 hours. The synthesis was confirmed by H-NMR analysis wherein the peak of methylene group of the polysiloxane was observed at 2.65ppm, the peak of methoxy group was observed at 3.85ppm, and the peak of hydrogen of benzene ring was observed at 7.1 to 7.5ppm.

A polycarbonate resin composition was prepared by mixing the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3022PJ, M_v: 21,000, Samyang Corporation) in a weight ratio of 40 : 60. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Example 2

In a 500mL three-necked flask equipped with a condenser, 0.4 mol of monomer (BY16-799, Dow Corning) was dissolved in 300mL of chloroform under nitrogen atmosphere, and then 67mL of triethylamine (TEA) catalyst was added thereto. Under refluxing of the resulting solution, 0.2 mol of terephthaloylchloride (TCL) dissolved in 1,000mL of chloroform was slowly added thereto for 1 hour, and the resulting solution was refluxed for 12 hours. After the reaction was completed, the solvent was removed from the solution, and the product was dissolved in acetone, washed with hot distilled water, and dried for 24 hours in a vacuum oven to prepare a hydroxy-terminated siloxane having ester linkage of the following chemical formula 7. The synthesis was confirmed by H-NMR analysis wherein the peak of methylene group of the polysiloxane was observed at 2.6ppm, the peak of hydrogen of benzene ring of TCL was observed at 8.35ppm, and the peak of hydrogen of benzene ring of the polysiloxane was observed at 6.75 to 7.35ppm.

[Chemical formula 7]

An interfacial reaction of bisphenol A in an aqueous solution phase and phosgene gas was conducted in the presence of methylene chloride to prepare 400mL of an oligomeric polycarbonate mixture having a viscosity average molecular weight of about 1,000. To the obtained oligomeric polycarbonate mixture, 30% by weight of the hydroxy-terminated siloxane having ester linkage of chemical formula 7 dissolved in methylene chloride, 1.8mL of tetrabutylammonium chloride (TBACl), 1.5g of p-tert-butylphenol (PTBP) and 275μl of triethylamine (TEA, 15 wt% aqueous solution) were admixed and reacted for 30 minutes. The reacted oligomeric polycarbonate mixture was kept for phase separation. After the phases were separated, only the organic phase was collected and thereto 170g of an aqueous solution of sodium hydroxide, 360g of methylene chloride and 300μl of triethylamine (15 wt% aqueous solution) were admixed and reacted for 2 hours. After phase separation, the viscosity-increased organic phase was washed with alkali and separated. Next, the resulting organic phase was washed with 0.1N hydrochloric acid solution and then rinsed with distilled water 2 to 3 times. After rinsing was completed, the concentration of the organic phase was adjusted constantly and granulation was conducted by using a constant amount of pure water at 76°C. After granulation was completed, the product was dried first at 110°C for 8 hours, and second at 120°C for 10 hours. The synthesis of the copolymer was confirmed by H-NMR analysis wherein the peaks of methylene group of the polysiloxane were observed at 2.6ppm and 2.65ppm, the peak of hydrogen of benzene ring of TCL was observed at 8.35ppm, and the peak of hydrogen of benzene ring of the polysiloxane was observed at 6.95 to 7.5ppm.

A polycarbonate resin composition was prepared by mixing the prepared polysiloxane-polycarbonate copolymer and polycarbonate (3022PJ, M_v: 21,000, Samyang Corporation) in a weight ratio of 20 : 80. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Example 3

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 20% by weight of hydroxy-terminated siloxane of the above chemical formula 7, and the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3027PJ, M_v: 24,600, Samyang Corporation) were mixed in a weight ratio of 30 : 70. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Example 4

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 20% by weight of hydroxy-terminated siloxane of the following chemical formula 8, and the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3022PJ, M_v: 21,000, Samyang Corporation) were mixed in a weight ratio of 30 : 70. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

[Chemical formula 8]

Example 5

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 30% by weight of hydroxy-terminated siloxane of the above chemical formula 8, and the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3022PJ, M_v: 21,000, Samyang Corporation) were mixed in a weight ratio of 15 : 85. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Comparative Example 1

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 8% by weight of hydroxy-terminated siloxane of the above chemical formula 7, and the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3022PJ, M_v: 21,000, Samyang Corporation) were mixed in a weight ratio of 60 : 40. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Comparative Example 2

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 9% by weight of hydroxy-terminated siloxane of the above chemical formula 8, and the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3027PJ, M_v: 24,600, Samyang Corporation) were mixed in a weight ratio of 30 : 70. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Comparative Example 3

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 45% by weight of hydroxy-terminated siloxane of the above chemical formula 8, and the prepared polysiloxane-polycarbonate copolymer and a polycarbonate (3027PJ, M_v: 24,600, Samyang Corporation) were mixed in a weight ratio of 40 : 60. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below. The composition of Comparative Example 3 could not be molded by injection, and thus its low-temperature impact resistance could not be measured.

Comparative Example 4

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 8% by weight of hydroxy-terminated siloxane of the above chemical formula 7, and the prepared polysiloxane-polycarbonate copolymer was used alone without mixing it with a polycarbonate. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Comparative Example 5

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that the polysiloxane-polycarbonate copolymer was prepared by using 20% by weight of hydroxy-terminated siloxane of the above chemical formula 7, and the prepared polysiloxane-polycarbonate copolymer was used alone without mixing it with a polycarbonate. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Comparative Example 6

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that a polycarbonate (3022PJ, M_v: 21,000, Samyang Corporation) was used alone without any polysiloxane-polycarbonate copolymer. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Comparative Example 7

A polycarbonate resin composition was prepared by the same method as described in Example 1, except that a polycarbonate (3030PJ, M_v: 31,200, Samyang Corporation) was used alone without any polysiloxane-polycarbonate copolymer. The properties of the prepared polycarbonate resin composition were measured, and the results are shown in Table 1 below.

Table 1

As shown in Table 1 above, the polycarbonate resin compositions prepared according to the Examples showed better impact resistance at room temperature and flowability, and remarkably superior low-temperature impact resistance, as compared with the polycarbonate resin compositions prepared according to the Comparative Examples.

The method for measuring the above properties used in the Examples and the Comparative Examples were as follows.

(a) H-NMR (nuclear magnetic resonance spectroscopy): This analysis was conducted by using Avance DRX 300 (Bruker).

(b) Viscosity average molecular weight (M_v): The viscosity of methylene chloride solution was measured by using an Ubbelohde Viscometer at 20°C, and the limiting viscosity [η] therefrom was calculated according to the following equation.

[η]=1.23x10^-5 Mv^0.83

(c) Impact resistance: Impact resistance was measured by using an impact test machine (RESIL IMPACTOR, CEAST Co., Ltd.) at room temperature and -50°C.

(d) M.I. (Melt Index): The melt index, which indicates flowability under certain temperatures and loads, was measured at 300°C under a load of 1.2kg_f according to ASTM D1238.

The present invention has been described with reference to concrete examples. A person skilled in the art would understand that the present invention can be realized as a modified form within a scope not departing from the essential characteristics of the present invention. Accordingly, the disclosed examples must be considered in their illustrative aspect and not their limitative aspect. The scope of the present invention is shown not in the aforesaid explanation but in the appended claims, and all differences within a scope equivalent thereto should be interpreted as being included in the present invention.

Claims

A polycarbonate resin composition comprising a polysiloxane-polycarbonate copolymer and a polycarbonate, wherein the amount of siloxane in the polysiloxane-polycarbonate copolymer is 10 to 35% by weight.
The composition according to claim 1, wherein the polysiloxane-polycarbonate copolymer comprises, as repeating units, a hydroxy-terminated siloxane of the following chemical formula 1a or chemical formula 1; and a polycarbonate block of the following chemical formula 4:.

[Chemical formula 1a]

wherein, in chemical formula 1a,

R₁ independently represents hydrogen atom, halogen atom, hydroxy group, or alkyl group, alkoxy group or aryl group having 1 to 20 carbon atoms;

R₂ independently represents hydrocarbon group having 1 to 13 carbon atoms or hydroxy group;

R₃ independently represents alkylene group having 2 to 8 carbon atoms;

m independently represents an integer of 0 to 4; and

n represents an integer of 2 to 1,000;

[Chemical formula 1]

wherein, in chemical formula 1,

R₁ independently represents hydrogen atom, halogen atom, hydroxy group, or alkyl group, alkoxy group or aryl group having 1 to 20 carbon atoms;

R₂ independently represents hydrocarbon group having 1 to 13 carbon atoms or hydroxy group;

R₃ independently represents alkylene group having 2 to 8 carbon atoms;

m independently represents an integer of 0 to 4;

n independently represents an integer of 2 to 1,000; and

A represents a structure of the following chemical formula 2 or 3;

[Chemical formula 2]

wherein, in chemical formula 2,

X is Y or NH-Y-NH, wherein Y represents linear or branched aliphatic group having 1 to 20 carbon atoms, cycloalkylene group, or mono- or polycyclic arylene group having 6 to 30 carbon atoms and being unsubstituted or substituted with halogen atom, alkyl group, alkoxy group, aryl group or carboxyl group;

[Chemical formula 3]

wherein, in chemical formula 3,

R₄ represents an aromatic hydrocarbon group or aromatic/aliphatic mixed-type hydrocarbon group having 6 to 30 carbon atoms, or an aliphatic hydrocarbon group having 1 to 20 carbon atoms;

[Chemical formula 4]

wherein, in chemical formula 4,

R₅ represents aromatic hydrocarbon group having 6 to 30 carbon atoms that is unsubstituted or substituted with alkyl group, cycloalkyl group, alkenyl group, alkoxy group, halogen atom, or nitro.
The composition according to claim 1, wherein the polysiloxane-polycarbonate copolymer has a viscosity average molecular weight of 10,000 to 70,000.
The composition according to claim 1, wherein the polycarbonate has a viscosity average molecular weight of 10,000 to 50,000.
The composition according to claim 1, wherein the amount of siloxane in the total composition is from 3 to 12% by weight.
The composition according to claim 1, wherein the weight ratio of the polysiloxane-polycarbonate copolymer : polycarbonate is 10 : 90 to 50 : 50.
A method for preparing the polycarbonate resin composition of claim 1, the method comprising:

a step of reacting hydroxy-terminated siloxane and oligomeric polycarbonate under an interfacial reaction condition to form a polysiloxane-polycarbonate intermediate;

a step of polymerizing the intermediate by using a first polymerization catalyst to prepare a polysiloxane-polycarbonate copolymer having a siloxane amount of 10 to 35% by weight; and

a step of mixing the prepared polysiloxane-polycarbonate copolymer and a polycarbonate.
The method for preparing the composition according to claim 7, wherein the step for forming the intermediate comprises:

a step of mixing the hydroxy-terminated siloxane and the oligomeric polycarbonate in a weight ratio of 10 : 90 to 35 : 65.
The method for preparing the composition according to claim 7, wherein the step for forming the intermediate comprises:

a step of forming a mixture comprising the hydroxy-terminated siloxane and the oligomeric polycarbonate,

and wherein the mixture further comprises a phase transfer catalyst, a molecular weight-controlling agent and a second polymerization catalyst.
The method for preparing the composition according to claim 7, wherein the step for forming the intermediate comprises:

a step of forming a mixture comprising the hydroxy-terminated siloxane and the oligomeric polycarbonate; and

after completion of the reaction of the hydroxy-terminated siloxane and the oligomeric polycarbonate, a step of extracting an organic phase from the resulting mixture,

and wherein the step of polymerizing the intermediate comprises:

a step of providing the first polymerization catalyst to the extracted organic phase.
The method for preparing the composition according to claim 7, wherein the oligomeric polycarbonate has a viscosity average molecular weight of 800 to 20,000.