KR20210050038A - Thermoplastic resin composition having excellent scratch resistance and impact resistance and molded article prepared from the same - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition having excellent scratch resistance and impact resistance and a molded article prepared therefrom and, more specifically, to a thermoplastic resin composition containing a combination of a polycarbonate resin, a polysiloxane-polycarbonate copolymer including a hydroxy-terminated siloxane in a specific content or more as a repeating unit, branched polycarbonate, and a modified acrylic copolymer, having excellent scratch resistance and impact resistance while having excellent balance of properties such as transparency, fluidity, heat resistance, and the like at the same time, and having excellent compatibility in post-treatment coating, and a molded article prepared therefrom.

Description

Thermoplastic resin composition having excellent scratch resistance and impact resistance and molded article prepared from the same}

The present invention relates to a thermoplastic resin composition having excellent scratch resistance and impact resistance, and a molded article manufactured therefrom, and more particularly, a polycarbonate resin, a polysiloxane-polycarbonate comprising a hydroxy-terminated siloxane having a specific content or more as a repeating unit. It contains a combination of copolymer, branched polycarbonate and modified acrylic copolymer, has excellent scratch resistance and impact resistance, has excellent balance of physical properties such as transparency, fluidity, and heat resistance, and has excellent compatibility in post-treatment coatings. It relates to a thermoplastic resin composition and a molded article manufactured therefrom.

Polycarbonate resin is a general-purpose thermoplastic engineering plastic that is manufactured by polycondensation of bisphenol A and phosgene and has a glass transition temperature of around 150°C. It has excellent mechanical properties such as tensile strength and impact strength, and has numerical stability, heat resistance, and optical transparency. Due to its superiority, it is a highly heat-resistant engineering plastic that replaces glass, and its use field is expanding day by day, such as being used as a housing for electric/electronic products or as a plate for construction and advertisement. The physical properties of the polycarbonate resin are derived from the phenyl group and the carboxyl group, and the molecular structural characteristics such as the rigidity of the molecular chain and the confinement of rotation affect the physical properties.

However, since polycarbonate resin has limited scratch resistance, there are many limitations to use for applications that are exposed to the exterior without surface coating. In particular, in the case of using polycarbonate resin as a case material for cell phone housings, TV housings, computer monitor housings, copiers, printers, notebook batteries, lithium batteries, etc. that require contact with various chemical products in the electric/electronic field, heat resistance or mechanical properties In addition, excellent impact resistance is required.

Conventionally, there have been efforts to improve the physical properties of polycarbonate by blending polycarbonate and other thermoplastic resins. For example, U.S. Patent No. 3,218,372 discloses a resin composition in which polycarbonate and polyalkylene terephthalate are mixed to lower the melt viscosity and have improved ductility than polyalkylene terephthalate. However, since the two resins used in this patent have poor compatibility, the composition becomes opaque and the impact strength is lowered. In addition, U.S. Patent No. 4,391,954 discloses a resin composition consisting of a copolyester consisting essentially of repeating units derived from a mixture consisting of polycarbonate, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedimethanol. Sufficient impact strength cannot be obtained with the composition. U.S. Patent No. 4,634,737 discloses a resin composed of a copolymerized polycarbonate having an ester bond of 25 to 90 mol% and a copolyester composed of isophthalic acid, terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol and an olefin acrylate copolymer Although compositions are disclosed, these compositions also become opaque and do not provide sufficient impact strength. U.S. Patent No. 4,188,314 discloses a sheet molding product having improved chemical resistance, including polycarbonate and a copolyester derived from isophthalic acid, terephthalic acid and 1,4-cyclohexanedimethanol. It does not provide impact strength.

Therefore, as a thermoplastic resin composition using polycarbonate, there is still a need for a resin composition in which scratch resistance, transparency, impact resistance, and heat resistance are all excellently balanced.

The present invention is to solve the problems of the prior art described above, as a thermoplastic resin composition using polycarbonate, has excellent scratch resistance and impact resistance, as well as excellent balance of physical properties such as transparency, fluidity, and heat resistance, and also post-treatment. It is a technical problem to provide a thermoplastic resin composition having excellent compatibility in coating and a molded article manufactured therefrom.

In order to solve the above technical problem, the present invention includes (A) a polycarbonate resin, (B) a hydroxy-terminated siloxane and a polycarbonate block as a repeating unit, and the hydroxy-terminated siloxane content is 6.1% by weight or more, a polysiloxane- It provides a thermoplastic resin composition comprising a polycarbonate copolymer, (C) a branched polycarbonate, and (D) a modified acrylic copolymer.

According to an embodiment of the present invention, the hydroxy-terminated siloxane in the polysiloxane-polycarbonate copolymer has the following Formula 1a or Formula 1:

[Formula 1a]

In Formula 1a, R ₁ independently represents a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group, an alkoxy group, or an aryl group; R ₂ independently represents a hydrocarbon group or a hydroxy group; R ₃ independently represents an alkylene group having 2 to 8 carbon atoms; m is independently an integer from 0 to 4; n is an integer of 30 to 200,

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and m are as defined in Formula 1a; n is independently, an integer of 15 to 100, A represents the structure of the following formula (2) or (3),

[Formula 2]

In Formula 2, X is Y or NH-Y-NH, where Y is a C 1 to C 20 linear or branched aliphatic group, a cycloalkylene group, or a halogen atom, an alkyl group, an alkoxy group, an aryl group or a carboxyl group substituted Or unsubstituted mononuclear or polynuclear arylene group having 6 to 30 carbon atoms,

[Formula 3]

In Formula 3, R ₄ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic/aliphatic mixed hydrocarbon group, or an aliphatic hydrocarbon group having 1 to 20 carbon atoms.

In addition, according to an embodiment of the present invention, the polycarbonate block in the polysiloxane-polycarbonate copolymer has the following formula (4):

[Formula 4]

In Formula 4, R ₅ is a divalent alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms substituted or unsubstituted with a halogen atom or nitro. Show.

According to another aspect of the present invention, there is provided a molded article manufactured by processing the thermoplastic resin composition of the present invention.

The thermoplastic resin composition according to the present invention has excellent scratch resistance and impact resistance, and at the same time has excellent balance of physical properties such as transparency, fluidity (especially sufficient fluidity for injection into thin-film injection products), heat resistance, and high surface energy. There is an advantage in the post-processing coating process. Therefore, it can be usefully applied to various products such as mobile phone housings, TV housings, refrigerator housings, copiers, and printers that are required with excellent scratch resistance and impact resistance.

Figure 1 (A) is a graph showing the tendency of pencil hardness and impact strength according to the PMPA content of a general PC / co-PMPA composition, Figure 1 (B) is a PC / Si- according to an embodiment of the present invention. It shows the tendency of pencil hardness and impact strength according to the PMPA content of the PC/PMPA composition.

Hereinafter, the present invention will be described in detail.

(A) Polycarbonate resin

As the polycarbonate resin included in the thermoplastic resin composition of the present invention, a thermoplastic aromatic polycarbonate resin may be used, and the thermoplastic aromatic polycarbonate resin may be prepared from a dihydric phenol, a carbonate precursor, and a molecular weight modifier.

The dihydric phenols are, for example, a monomer of a polycarbonate resin having the following structure.

In the above, X includes both a case where a functional group such as an alkyl group, a sulfide, an ether, a sulfoxide, a sulfone, and a ketone is included, and a case where there is no functional group at all. Preferably X represents a straight, branched or cyclic alkylene group, more preferably X represents a straight, branched or cyclic alkylene group containing 1 to 10 carbons. R ₁ and R ₂ represent hydrogen, a halogen atom, a linear, branched or cyclic alkyl group. Meanwhile, n and m may independently be integers of 0 to 4. Here, when n and/or m is 0, it means that _{R 1} and/or R _{2 is hydrogen.}

Non-limiting examples of the dihydric phenols include bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)naphthylmethane, bis(4-hydroxyphenyl) Phenyl)-(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 (bisphenol A), etc. Among them, bisphenol A is representative.

The carbonate precursor is another monomer of the polycarbonate resin, and it is preferable to use phosgene (carbonyl chloride). Non-limiting examples of carbonate precursors include carbonyl bromide, bis halo formate, diphenylcarbonate or dimethylcarbonate, and the like.

As the molecular weight modifier, a known material, that is, a monofunctional compound similar to a monomer used to prepare a thermoplastic aromatic polycarbonate resin may be used. As a non-limiting example, derivatives thereof based on phenol (e.g., para-isopropylphenol, para-tert-butylphenol, para-cumylphenol, para-isooctylphenol, para-isononylphenol, etc.) Can be used, and other kinds of substances such as aliphatic alcohols can be used, and among them, it is most preferable to apply para-tert-butylphenol (PTBP).

Such dihydric phenols, carbonate precursors, and aromatic polycarbonate resins prepared with molecular weight modifiers include, for example, linear polycarbonate resins, branched polycarbonate resins, copolycarbonate resins, polyester carbonate resins, etc. There is this.

Meanwhile, in exemplary embodiments of the present invention, it is preferable to use a thermoplastic aromatic polycarbonate resin having a viscosity average molecular weight (M _{v) of 15,000 to 40,000 measured in a methylene chloride solution at 25° C., and 17,000 to 30,000.} It is more preferable to use it. When the viscosity average molecular weight is less than 15,000, mechanical properties such as impact strength and tensile strength may be greatly reduced, and when it exceeds 40,000, problems may occur in processing of the resin due to an increase in melt viscosity. In particular, in terms of mechanical properties such as impact strength and tensile strength, the viscosity average molecular weight is preferably 20,000 or more, and in terms of processability, the viscosity average molecular weight is preferably 30,000 or less.

In one embodiment, in the thermoplastic resin composition of the present invention, the (A) polycarbonate resin may be included in an amount of 5 to 90% by weight based on 100% by weight of the composition. If the content of the (A) polycarbonate resin in the composition is less than the above level, impact resistance, heat resistance, etc. may deteriorate, and if it is higher than the above level, scratch resistance may be deteriorated.

More specifically, the (A) polycarbonate resin content in 100% by weight of the thermoplastic resin composition of the present invention may be 10% by weight or more, 20% by weight or more, 25% by weight or more, 30% by weight or more, or 40% by weight or more. In addition, it may be 85% by weight or less, 80% by weight or less, 75% by weight or less, or 70% by weight or less.

(B) Polysiloxane -Polycarbonate copolymer

The polysiloxane-polycarbonate copolymer contained in the thermoplastic resin composition of the present invention includes a hydroxy-terminated siloxane and a polycarbonate block as a repeating unit.

In one embodiment, the weight average molecular weight (Mw) of the hydroxy-terminated siloxane contained in the polysiloxane-polycarbonate copolymer may be 2,500 to 15,000, more specifically 3,500 to 13,000, more specifically 4,000 to 9,000. Can be If the weight average molecular weight of the hydroxy-terminated siloxane is less than 2,500, the effect of improving the low-temperature impact resistance may be insignificant, and if it exceeds 15,000, the reactivity decreases, and there may be a problem in synthesizing the polysiloxane-polycarbonate copolymer with a desired molecular weight.

In the present invention, the content of the hydroxy-terminated siloxane in the polysiloxane-polycarbonate copolymer is 6.1% by weight or more based on 100% by weight of the copolymer. If the hydroxy-terminated siloxane content in the copolymer is less than 6.1% by weight, the impact resistance is poor.

In one embodiment, the content of the hydroxy-terminated siloxane in the polysiloxane-polycarbonate copolymer may be 6.5% by weight or more or 7% by weight or more, based on 100% by weight of the copolymer. There is no particular limitation on the upper limit of the hydroxy-terminated siloxane content in the copolymer, but in consideration of economic efficiency, it may be 15% by weight or less, 10% by weight or less, or 9% by weight or less.

In one embodiment, the hydroxy-terminated siloxane in the polysiloxane-polycarbonate copolymer has the following Formula 1a or Formula 1:

[Formula 1a]

In Formula 1a,

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

R ₂ independently represents a C 1 to C 13 hydrocarbon group or a hydroxy group. For example, R ₂ is an alkyl group or alkoxy group having 1 to 13 carbon atoms, an alkenyl group or alkenyloxy group having 2 to 13 carbon atoms, a cycloalkyl group or cycloalkoxy group having 3 to 6 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, It may be a C7-C13 aralkyl group or an aralkoxy group, or a C7-C13 alkaryl group or alkaryloxy group.

R ₃ independently represents an alkylene group having 2 to 8 carbon atoms.

m is independently an integer of 0 to 4.

n is an integer of 30 to 200, preferably an integer of 40 to 170, and more preferably an integer of 50 to 120.

) 사용할 수 있으나, 반드시 이에 한정되는 것은 아니다.In one embodiment, Dow Corning's siloxane monomer (

) Can be used, but is not necessarily limited thereto.

[Formula 1]

In Formula 1,

R ₁ , R ₂ , R ₃ and m are the same as previously defined in Formula 1a, and n is independently an integer of 15 to 100, preferably an integer of 20 to 80, more preferably an integer of 25 to 60 And A represents the structure of the following formula (2) or (3).

[Formula 2]

In Formula 2, X is Y or NH-Y-NH, where Y is a linear or branched aliphatic group having 1 to 20 carbon atoms, a cycloalkylene group (eg, a cycloalkylene group having 3 to 6 carbon atoms), or a halogen An atom, an alkyl group, an alkoxy group, an aryl group, or a carboxyl group substituted or unsubstituted mononuclear or polynuclear arylene group having 6 to 30 carbon atoms. For example, Y is an aliphatic group unsubstituted or substituted with a halogen atom, an aliphatic group containing an oxygen, nitrogen or sulfur atom in the main chain, or an aryl which may be derived from bisphenol A, resorcinol, hydroquinone or diphenylphenol. It may be a ren group, for example, it may be represented by the following formulas 2a to 2h.

[Formula 2a]

[Formula 2b]

[Formula 2c]

[Formula 2d]

[Formula 2e]

[Formula 2f]

[Chemical Formula 2g]

[Formula 2h]

[Formula 3]

In Formula 3, R ₄ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic/aliphatic mixed hydrocarbon group, or an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Here, R ₄ may have a structure including halogen, oxygen, nitrogen, or sulfur in addition to a carbon atom. For example, R ₄ can be phenyl, chlorophenyl or tolyl (preferably phenyl).

In one embodiment, the hydroxy-terminated siloxane of Formula 1 may be a reaction product of the hydroxy-terminated siloxane of Formula 1a (wherein n is an integer of 15 to 100) and an acyl compound. Here, the acyl compound may have, for example, an aromatic, aliphatic, or mixed structure including both aromatic and aliphatic. When the acyl compound is aromatic or mixed, it may have 6 to 30 carbon atoms, and if it is aliphatic, it may have 1 to 20 carbon atoms. The acyl compound may further contain a halogen, oxygen, nitrogen or sulfur atom.

In another embodiment, the hydroxy-terminated siloxane of Formula 1 may be a reaction product of a hydroxy-terminated siloxane of Formula 1a (where n is an integer of 15 to 100) and a diisocyanate compound. Here, 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 Formula 1 is a reaction product of a hydroxy-terminated siloxane of Formula 1a (wherein n is an integer of 15 to 100) and a phosphorus-containing compound (aromatic or aliphatic phosphate compound). I can. Here, the phosphorus-containing compound may be represented by the following Formula 1b.

[Formula 1b]

In Formula 1b, R ₄ is as previously defined in Formula 3, and Z independently represents phosphorus, a halogen atom, a hydroxy group, a carboxyl group, an alkyl group (having 1 to 20 carbon atoms), an alkoxy group or an aryl group.

In one embodiment, the polycarbonate block in the polysiloxane-polycarbonate copolymer has the following Formula 4:

[Formula 4]

In Formula 4, R ₅ is a divalent alkyl group (e.g., a divalent alkyl group having 1 to 13 carbon atoms), a cycloalkyl group (e.g., a divalent cycloalkyl group having 3 to 6 carbon atoms) , An alkenyl group (eg, a C2-C13 divalent alkenyl group), an alkoxy group (eg, a C1-C13 divalent alkoxy group), or a halogen atom or a nitro-substituted or unsubstituted C6-C30 It represents a divalent aromatic hydrocarbon group.

Here, the aromatic hydrocarbon group may be derived from a compound having a structure represented by the following Formula 4a.

[Formula 4a]

In Formula 4a, X is an alkylene group, a linear, branched or cyclic alkylene group having no functional group, or a linear, branched group containing functional groups such as sulfide, ether, sulfoxide, sulfone, ketone, naphthyl, and isobutylphenyl. Represents a topographic or cyclic alkylene group, and preferably, X may be a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms; R ₆ independently represents a hydrogen atom, a halogen atom, or an alkyl group, such as a C 1 to C 20 linear, branched or C 3 to C 20 (preferably 3 to 6) cyclic alkyl group; n and m are independently integers of 0 to 4.

The compound of Formula 4a is, 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)methane, Resorcinol, Hydroquine, 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-hydroxyl) Roxyphenyl)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, and 2,6-dihydroxynaphthalene, but are not limited thereto. . Representative of these is 2,2-bis(4-hydroxyphenyl)propane (bisphenol A). Other functional dihydric phenols may refer to U.S. Patent Nos. Can be used.

In the case of the carbonate precursor, as another monomer of the polycarbonate resin, for example, carbonyl chloride (phosgene), carbonyl bromide, bis halo formate, diphenyl carbonate or dimethyl carbonate may be used.

The preferred viscosity average molecular weight (Mv) of the polysiloxane-polycarbonate copolymer used in the present invention is 15,000 to 30,000, more preferably 17,000 to 22,000. If the viscosity average molecular weight of the polysiloxane-polycarbonate copolymer is less than 15,000, mechanical properties may be significantly deteriorated, and if it exceeds 30,000, a problem may occur in processing of the resin due to an increase in melt viscosity.

In one embodiment, in the thermoplastic resin composition of the present invention, the (B) polysiloxane-polycarbonate copolymer may be included in an amount of 5 to 90% by weight based on 100% by weight of the composition. If the content of the (B) polysiloxane-polycarbonate copolymer in the composition is less than the above level, impact resistance may deteriorate, and if it is higher than the above level, transparency may deteriorate.

More specifically, the content of the (B) polysiloxane-polycarbonate copolymer in 100% by weight of the thermoplastic resin composition of the present invention is 5% by weight or more, 10% by weight or more, 15% by weight or more, 20% by weight or more, or 25% by weight. It may be greater than or equal to 80% by weight, 70% by weight or less, 60% by weight or less, or 50% by weight or less.

(C) Basin Polycarbonate

The branched polycarbonate contained in the thermoplastic resin composition of the present invention is distinguished from the (A) polycarbonate resin, and is used to improve the impact resistance of the resin composition.

The branched polycarbonate is a bisphenol A and an organic compound having three or more functional groups as a branching agent [Japanese Patent Publication No. 60-11733, US Patent No. 4,415,753], and a phenol having a trivalent or tetravalent hydroxy group is used. Or it may be prepared using an aromatic compound containing trivalent or tetravalent chloroformate [US Patent No. 5,021,521, US Patent No. 5,283,314], or the like. That is, an organic compound having three or more functional groups, a phenol having a trivalent or tetravalent hydroxy group, or an aromatic compound containing a trivalent or tetravalent chloroformate group may be used as the branching agent.

In one embodiment, the general structure of the branched polycarbonate resin may be represented by the following Formula 5:

[Formula 5]

In Formula 5, A is a moiety derived from a branching agent, and may be, for example, tetravalent phenyl.

In one embodiment, the viscosity average molecular weight (Mv) of the branched polycarbonate may be 10,000 to 20,000, more specifically 15,000 to 20,000.

In one embodiment, in the thermoplastic resin composition of the present invention, the (C) branched polycarbonate may be included in an amount of 1 to 50% by weight based on 100% by weight of the composition. If the content of the (C) branched polycarbonate in the composition is less than the above level, impact resistance may deteriorate, and if it is higher than the above level, scratch resistance may deteriorate.

More specifically, the (C) branched polycarbonate content in 100% by weight of the thermoplastic resin composition of the present invention may be 2% by weight or more, 5% by weight or more, 10% by weight or more, or 15% by weight or more, and 45 It may be less than or equal to 40% by weight, less than or equal to 35% by weight, or less than or equal to 30% by weight.

(D) modified acrylic copolymer

The modified acrylic copolymer contained in the thermoplastic resin composition of the present invention is used to improve the scratch resistance of the resin composition.

In one embodiment, the modified acrylic copolymer may be a copolymer of an aromatic or alicyclic acrylic compound and a compound copolymerizable therewith, and the copolymerizable compound is an alkyl methacrylate, an alkyl acrylate, an unsaturated carboxylic acid, an acid anhydride , Acrylate containing a hydroxy group, amides, nitriles, allyl glycidyl ether, glycidyl methacrylate, styrene, or a combination thereof.

According to one embodiment of the present invention, the modified acrylic copolymer may be a copolymer of polymethyl methacrylate (PMMA), and more specifically, poly(methyl methacrylate-co-phenylmethacrylate). Rate) ((Poly(methyl methacrylate-co-phenyl methacrylate), PMPA).

In one embodiment, the weight average molecular weight of the modified acrylic copolymer may be 10,000 to 20,000, more specifically 15,000 to 20,000.

In one embodiment, in the thermoplastic resin composition of the present invention, the (D) modified acrylic copolymer may be included in an amount of 1 to 50% by weight based on 100% by weight of the composition. If the content of the (D) modified acrylic copolymer in the composition is less than the above level, scratch resistance may deteriorate, and if it is higher than the above level, impact resistance may deteriorate.

More specifically, the (D) modified acrylic copolymer content in 100% by weight of the thermoplastic resin composition of the present invention may be 2% by weight or more, 5% by weight or more, 7% by weight or more, or 10% by weight or more, and 45 It may be less than or equal to 40% by weight, less than or equal to 35% by weight, or less than or equal to 30% by weight.

In addition to the above components, the thermoplastic resin composition of the present invention may further include a thermally stable compound.

Examples of heat-stable compounds that can be used in the composition of the present invention include heat stabilizers and antioxidants, and these may be used alone or in combination of two or more.

In one embodiment, in the thermoplastic resin composition of the present invention, the thermally stable compound may be included in an amount of 0.01 to 1% by weight based on 100% by weight of the composition, more specifically 0.01 to 0.5% by weight, 0.02 to 0.5% by weight, or It may be contained in an amount of 0.02 to 0.3% by weight. If the content of the thermally stable compound in the composition is less than the above level, the fluidity change of the composition may become severe and processability may be deteriorated. Conversely, if it is more than the above level, there may be problems such as gas generation during molding processing.

The thermoplastic resin composition of the present invention may further contain one or more other optional additives.

In one embodiment, the resin composition of the present invention further comprises inorganic fillers such as silica, silicate, alumina, glass fiber, glass beads, glass flakes, clay, talc, mica, calcium carbonate, etc. to increase stiffness, heat resistance, and dimensional stability. It may contain, and it may be incorporated in an amount of 0.1 to 50% by weight based on the total resin composition.

In one embodiment, the resin composition of the present invention may additionally contain organic fillers such as carbon fiber and carbon black in order to increase the black color expression and conductivity, which is incorporated in an amount of 0.1 to 30% by weight based on the total resin composition. Can be.

In one embodiment, the resin composition of the present invention may further include a release agent, a lubricant, an ultraviolet stabilizer, etc. as other processing aids, and these may be used in an amount of 0.01 to 0.5% by weight based on the total resin composition.

According to another aspect of the present invention, there is provided a molded article manufactured by processing the thermoplastic resin composition of the present invention described above.

The molded article includes interior materials and exterior materials that require scratch resistance and excellent impact strength, and specifically includes, but is not limited to, a mobile phone housing and a housing of an electric and electronic product.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. However, the scope of the present invention is not limited to these.

[ Example ]

[Used compound]

(A) Polycarbonate resin (PC)

Linear polycarbonate derived from bisphenol-A (viscosity average molecular weight (Mv): 22,000)

(B) Polysiloxane -Polycarbonate copolymer ( Si -PC)

Si-PC1: Content of hydroxy-terminated siloxane in the copolymer: 9% by weight, Mv: 26,000 (Samyang)

Si-PC2: Content of hydroxy-terminated siloxane in the copolymer: 7% by weight, Mv: 26,000 (Samyang)

Si-PC3: Content of hydroxy-terminated siloxane in the copolymer: 6% by weight, Mv: 26,000 (LG Chemical)

(C) Basin Polycarbonate (BR-PC)

Branched polycarbonate derived from bisphenol-A using phenol having a tetravalent hydroxy group as a branching agent (Mv: 18,000)

(D) Modified acrylic copolymer ( PMPA )

Poly(methylmethacrylate-co-phenylmethacrylate)

(E) Thermal stability compound

Thermal stabilizer (alk240, song1076)

[Examples 1 to 4 and Comparative Examples 1 to 3]

In the composition and contents shown in Table 1 below, the composition components are mixed with a Henschel mixer and uniformly dispersed, and then extruded at a temperature of 240 to 270°C in a twin screw melt mixing extruder with L/D = 40 and Φ = 25 mm to form pellets. After manufacturing, drying for 4 hours or more in a hot air dryer at 100 to 120°C, the specimen was injection molded at a temperature of 260 to 280°C.

[Measurement of physical properties]

(1) Fluidity (MI): In accordance with ASTM D1238, it was measured at 300°C and 1.2kgf.

(2) Transmittance: It was measured using a 3T specimen according to ASTM D1003.

(3) Izod impact strength (Izod): The thickness of the specimen was 1/8”, and it was measured according to ASTM D256 at room temperature.

(4) Heat deflection temperature (HDT): It was measured at 18.56kgf load according to ASTM D648.

(5) Rockwell hardness: Measured by M scale according to ASTM D785.

(6) Pencil hardness: In accordance with ASTM D3363, the pencil hardness was measured after leaving for 48 hours at 23°C and 50% relative humidity. It was applied to the surface of the specimen three times, and the degree of scratching was observed with the naked eye. When pencil scratch marks occur more than two times on the surface of the specimen, the pencil hardness grade was classified as follows.

6B-5B-4B-3B-2B-B-HB-F-H-2H-3H-4H-5H-6H

(7) Surface energy: Surface energy was measured through arcotest's TEST INKS according to ASTM D2578.

[Table 1]

As can be seen from the results of Table 1, the compositions of Examples 1 to 5 according to the present invention all have excellent scratch resistance (Rockwell hardness and pencil hardness) and impact resistance (Izod impact strength), and at the same time, transparency, fluidity, and heat resistance It has excellent balance of physical properties such as, and has excellent compatibility in post-treatment coating. On the other hand, the composition of Comparative Example 1 was poor in impact resistance, the composition of Comparative Example 2 was poor in scratch resistance, the composition of Comparative Example 3 was poor in impact resistance, and the composition of Comparative Example 4 had impact resistance and surface energy properties. This was poor, and the composition of Comparative Example 5 had poor impact resistance.

Claims (9)

(A) polycarbonate resin,
(B) a polysiloxane-polycarbonate copolymer comprising a hydroxy-terminated siloxane and a polycarbonate block as a repeating unit, and wherein the hydroxy-terminated siloxane content is 6.1% by weight or more,
(C) a branched polycarbonate, and
(D) containing a modified acrylic copolymer,
Thermoplastic resin composition. The thermoplastic resin composition according to claim 1, wherein the (A) polycarbonate resin is a thermoplastic aromatic polycarbonate resin. The thermoplastic resin composition according to claim 1, wherein (A) the polycarbonate resin has a viscosity average molecular weight of 15,000 to 40,000. The thermoplastic resin composition according to claim 1, wherein (B) the hydroxy-terminated siloxane in the polysiloxane-polycarbonate copolymer has the following formula (1a) or formula (1):
[Formula 1a]

In Formula 1a, R ₁ independently represents a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group, an alkoxy group, or an aryl group; R ₂ independently represents a hydrocarbon group or a hydroxy group; R ₃ independently represents an alkylene group having 2 to 8 carbon atoms; m is independently an integer from 0 to 4; n is an integer from 30 to 200,
[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and m are the same as defined in Formula 1a; n is independently, an integer of 15 to 100, A represents the structure of the following formula (2) or (3),
[Formula 2]

In Formula 2, X is Y or NH-Y-NH, where Y is a C 1 to C 20 linear or branched aliphatic group, a cycloalkylene group, or a halogen atom, an alkyl group, an alkoxy group, an aryl group or a carboxyl group substituted A mononuclear or polynuclear arylene group having 6 to 30 carbon atoms or unsubstituted,
[Formula 3]

In Formula 3, R ₄ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic/aliphatic mixed hydrocarbon group, or an aliphatic hydrocarbon group having 1 to 20 carbon atoms. The thermoplastic resin composition according to claim 1, wherein the polycarbonate block in the (B) polysiloxane-polycarbonate copolymer has the following formula (4):
[Formula 4]

In Formula 4, R ₅ represents a divalent alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms substituted or unsubstituted with a halogen atom or nitro. The thermoplastic resin composition according to claim 1, wherein the (D) modified acrylic copolymer is poly(methylmethacrylate-co-phenylmethacrylate) (PMPA). The thermoplastic resin composition according to claim 1, further comprising a thermally stable compound. A molded article manufactured by processing the thermoplastic resin composition of claim 1. The molded article according to claim 8, which is a housing for electric/electronic products.

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