KR101422661B1 - Flameproof Thermoplastic Resin Composition - Google Patents

Abstract

The present invention is characterized in that a polystyrene resin having a predetermined molecular weight is applied to a polycarbonate resin / impactor reinforcement system, a rubber particle size and a kind of an impact reinforcement are specified, a phosphorus flame retardant is added and the content of each component is controlled, To a thermoplastic resin composition having remarkably improved dispersibility.
The flame retardant thermoplastic resin composition according to the present invention has an advantage of excellent flame retardancy, impact resistance, fluidity and appearance.

Description

Flameproof Thermoplastic Resin Composition "

The present invention relates to a flame retardant thermoplastic resin composition, and more particularly, to a flame retardant thermoplastic resin composition which comprises a polycarbonate resin / impact reinforcement system to which a polystyrene resin having a predetermined molecular weight is applied, a rubber particle size and a kind of the impact reinforcement are specified, The present invention relates to a thermoplastic resin composition having improved flame retardance, impact resistance, fluidity and appearance characteristics by dramatically improving the dispersibility of an impact modifier in a thermoplastic resin by controlling the content of each component.

The PC / ABS Alloy resin is a thermoplastic resin which is excellent in heat resistance and impact strength of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) And chemical resistance, so that it has excellent processing characteristics and mechanical properties. In addition, it exhibits excellent physical properties compared to ABS and can be used for various purposes because it can reduce cost compared to PC. In particular, halogen-free NH (non halogen) -PC / ABS resin is not harmful to the environment and does not cause environmental pollution, so it can be used in various electronic products and automobile parts such as monitor housings, hard disks, printers, Door handles, bumpers, and instrument panels.

Typical components of NH-PC / ABS are polycarbonate, ABS, phosphorus flame retardant, and are generally used for the exterior of electronic products that require high gloss, high flow and high impact. The content of rubber used as a stiffener is generally determined according to its size, and the impact, appearance and gloss of the resin are determined according to proper rubber selection and dispersion techniques. However, conventionally, affinity between polycarbonate resin and ABS (impact reinforcing material) is weak, and ABS is aggregated and aggregated with each other, resulting in lower dispersion efficiency on a polycarbonate resin matrix, and it is difficult to obtain desired impact strength against ABS content.

In addition, PC / ABS blend is mainly used in the case of high external appearance resin for TV exterior materials, but due to the limitation of coloring ability due to the nature of SAN, the market does not meet the high appearance requirement.

Japanese Patent Application Laid-Open No. 2009-203270 (2009.09.10.) Published Patent Publication No. 10-2004-0062428 (July 7, 2004)

DISCLOSURE OF THE INVENTION The present invention has been conceived to solve the above problems, and it is an object of the present invention to provide a polycarbonate resin / impactor reinforcement system which comprises applying a polystyrene resin having a predetermined molecular weight, specifying a rubber particle size and a kind of an impact reinforcement, The present invention aims to provide a thermoplastic resin composition having flame retardance, impact resistance, fluidity and appearance characteristics at the same time by dramatically improving the dispersibility of the impact modifier in the thermoplastic resin.

Another object of the present invention is to provide a molded article obtained by extruding or injecting the flame retardant thermoplastic resin composition.

In one embodiment, the present invention provides a method for producing a molded article, which comprises 50 to 95 parts by weight of a polycarbonate resin (a), 1 to 30 parts by weight of a polystyrene resin (b), 1 to 30 parts by weight of an impact reinforcement (c) And 1 to 20 parts by weight of a phosphorus-containing flame retardant (d) based on 100 parts by weight of the base resin (a) + (b) + (c), wherein the polystyrene resin (b) (C1) containing a rubbery polymer having an average particle diameter of 0.05 to 0.5 占 퐉 and a rubber-like polymer having an average particle diameter of 0.05 to 0.5 占 퐉 are contained in the rubber-modified vinyl-based graft copolymer And a core-shell graft copolymer (c2) comprising an acrylic-based shell.

The rubber-modified vinyl-based graft copolymer (c1) and the core-shell graft copolymer (c2) comprising an acrylic shell may be contained in a mixing ratio of 1: 1 to 1: 3.

The rubber-modified vinyl-based graft copolymer (c1) can be prepared by graft-polymerizing a monomer mixture containing a rubbery polymer, an aromatic vinyl compound and a vinyl cyanide compound.

The core-shell graft copolymer (c2) comprising the acryl-based shell may be obtained by copolymerizing an acrylic monomer, a heterocyclic monomer, an aromatic vinyl monomer, an aromatic vinyl monomer, an aromatic vinyl monomer, and an aromatic vinyl monomer into a rubbery polymer polymerized from a monomer of dienic monomer, acrylic monomer, silicone monomer, An unsaturated nitrile monomer or a combination of these unsaturated compounds is grafted; The unsaturated compound may be prepared by containing at least one acrylic monomer.

The polycarbonate resin may have a melt index of 5 to 100 g / 10 min (ISO 1133, 1.2 kg, 300 ° C).

The thermoplastic resin has an impact strength (ASTM D256, 1/8 ") of 45 to 55 kgf · cm / cm, a melt flow index (ISO 1133, 220 ° C., 10 kg) of 100 to 115 g / (UL94, 2 mm) may be VO.

In another aspect, the present invention relates to a molded article obtained by molding the flame retardant thermoplastic resin composition.

The thermoplastic resin composition according to the present invention has advantages of excellent impact resistance, fluidity, appearance and flame retardancy by dramatically increasing the dispersibility by controlling the shape and position of the impact reinforcement in the resin.

Accordingly, the present invention can be applied to the manufacture of various electrical and electronic products and automobile parts that require such properties simultaneously.

The flame retardant thermoplastic resin composition of the present invention comprises 50 to 95 parts by weight of a polycarbonate resin (a), 1 to 30 parts by weight of a polystyrene resin (b), 1 to 30 parts by weight of an impact reinforcement (c) And 1 to 20 parts by weight of a phosphorus-containing flame retardant (d) based on 100 parts by weight of the base resin (a) + (b) + (c), wherein the polystyrene resin (b) (C1) containing a rubbery polymer having an average particle diameter of 0.05 to 0.5 占 퐉 and a rubber-like polymer having an average particle diameter of 0.05 to 0.5 占 퐉 are contained in the rubber-modified vinyl-based graft copolymer And a core-shell graft copolymer (c2) comprising an acrylic-based shell.

Hereinafter, the configuration of the present invention will be described in more detail.

(a) Polycarbonate resin

The polycarbonate resin of the present invention can be produced by reacting a diphenol represented by the following formula (1) with phosgene, halogen formate or carbonic acid diester.

[Chemical Formula 1]

In the above formula, A represents a single bond, C ₁ -C ₅ alkylene, C ₁ -C ₅ alkylidene, C ₅ -C ₆ cycloalkylidene, -S- or -SO ₂ -.

The diphenols represented by the above formula (1) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis- (4-hydroxyphenyl) 2-methylbutane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2-bis- (3-chloro-4-hydroxyphenyl) 2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane and the like.

Specific examples of the diphenols include 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) - (4-hydroxyphenyl) -cyclohexane is preferably used, and 2,2-bis- (4-hydroxyphenyl) -propane, also referred to as bisphenol-A, is most preferably used.

The polycarbonate resin may be in the form of a branched chain. Preferably, the polycarbonate resin is used in an amount of 0.05 to 2 mol%, based on the total amount of diphenols used for polymerization, of tri- or more polyfunctional compounds such as trivalent or higher phenol Lt; / RTI > group.

The polycarbonate resin of the present invention preferably has a weight average molecular weight (Mw) in the range of 10,000 to 200,000 g / mol, and most preferably 15,000 to 80,000 g / mol.

In addition, the melt index of the polycarbonate resin of the present invention may be 5 to 100 g / 10 min at ISO 1133, 1.2 kg, and 300 ° C. For example, 80 to 99% by weight of a polycarbonate resin having 31 to 100 g / 10 min and 1 to 20% by weight of a polycarbonate resin having 5 to 30 g / 10 min can be used as the polycarbonate resin. % Can be mixed and used. When a polycarbonate resin having such a melt index range is used, the appearance of injection moldability and injection property can be improved.

As the polycarbonate used in the production of the resin composition of the present invention, homopolycarbonate, copolycarbonate or a blend form thereof may all be used. The polycarbonate may be used in place of an ester precursor, for example, an aromatic polyester-carbonate resin obtained by polymerization reaction in the presence of a bifunctional carboxylic acid.

In the present invention, the polycarbonate resin may be used in an amount of 50 to 95 parts by weight, preferably 65 to 95 parts by weight, and more preferably 70 to 90 parts by weight, based on 100 parts by weight of the total composition. The thermoplastic resin composition of the present invention can impart appropriate impact strength and heat resistance properties when the polycarbonate resin is used in such a content range.

(b) Polystyrene resin

The polystyrene resin of the present invention can be produced by bulk polymerization, suspension polymerization, emulsification and continuous polymerization method of an aromatic vinyl monomer.

The aromatic vinyl monomer may include styrene, paramethylstyrene,? -Methylstyrene, and 4-N-propylstyrene, preferably styrene and? -Methylstyrene.

The polystyrene resin may have a weight average molecular weight of 200,000 to 400,000 g / mol, preferably 250,000 to 350,000 g / mol.

In the present invention, the polystyrene resin having a weight-average molecular weight range is a type of emulsifier which improves the affinity between the polycarbonate and the impact reinforcement to improve the dispersibility of the impact reinforcement by optimizing the shape and position of the impact reinforcement added to the polycarbonate resin . Generally, there is almost no affinity between the polycarbonate and the impact reinforcement, and it is difficult to obtain an appropriate impact strength because the impact reinforcement is not uniformly dispersed due to aggregation and aggregation. When the content of the impact reinforcement is too high or the particle size is increased, Abnormal appearance such as unusual color, gate mark or the like occurs. The polystyrene resin imparts appropriate fluidity to the thermoplastic resin and allows the impact stiffener to be positioned on the interface of the polycarbonate resin and the polystyrene resin to be evenly dispersed on the thermoplastic resin matrix. Accordingly, the thermoplastic resin of the present invention can obtain a sufficient impact strength even with a small amount of impact reinforcement, and can improve coloring property and injection moldability, thereby securing high appearance characteristics.

Polystyrene domain size can be divided into physical mixing and thermodynamic factors. Physical factors include PC / PS viscosity difference and SEC (specific energy consumption) determined by screw RPM / process temperature. . However, physical blending is not thermodynamically unstable because it is not a fundamental improvement in compatibility of the polycarbonate / polystyrene blend. However, when a core-shell graft copolymer (c2) containing an acrylic shell having an intermediate affinity of polycarbonate / polystyrene is mixed, the acrylic domain is located at the polycarbonate / polystyrene interface. In the present invention, the core-shell graft copolymer (c2) containing an acrylic shell serves as a compatibilizer of the polycarbonate / polystyrene blend, and thus the PS domain size can be controlled to be small and the rubber dispersion can be maximized have. Thus, when the dispersion degree is maximized, excellent appearance characteristics are obtained.

In the present invention, the polystyrene resin may be used in an amount of 1 to 30 parts by weight, preferably 2 to 20 parts by weight, more preferably 5 to 15 parts by weight based on 100 parts by weight of the total composition. When the polystyrene resin is used in such a content range, the thermoplastic resin composition of the present invention can maximize the dispersibility of the impact reinforcement and ensure appropriate fluidity, thereby improving impact resistance and injection moldability and ensuring adequate flame retardancy .

(c) Impact reinforcement

( c1 ) Rubber Modification Vinyl-based Graft  Copolymer

The rubber-modified vinyl-based graft copolymer of the present invention can be produced by graft-polymerizing a monomer mixture containing a rubbery polymer, an aromatic vinyl compound and a vinyl cyanide compound. The content of each component is 40 to 70% by weight of a rubbery polymer and 30 to 60% by weight of a vinyl monomer, and 60 to 90% by weight of an aromatic vinyl compound and 10 to 40% By weight.

The rubbery polymer may be at least one selected from the group consisting of a polybutadiene rubber, an acrylic rubber, an ethylene / propylene rubber, a styrene / butadiene rubber, an acrylonitrile / butadiene rubber, an isoprene rubber, an acrylic rubber, a terpolymer of ethylene- / Polyalkyl (meth) acrylate rubber composites, either singly or in the form of a mixture thereof. Particularly, polybutadiene rubber is most preferable.

The average particle diameter of the rubbery polymer is preferably 0.05 to 0.5 占 퐉, more preferably 0.2 to 0.35 占 퐉. When the average particle diameter is in the above range, excellent appearance characteristics can be obtained while maintaining proper impact strength.

As the aromatic vinyl compound, styrene,? -Methylstyrene, halogen or alkyl-substituted styrene may be used, and styrene is preferable.

As the vinyl cyanide compound, acrylonitrile, methacrylonitrile and the like can be used, and acrylonitrile is preferable.

Further, graft polymerization can be performed by further adding monomers such as C1-C8 methacrylic acid alkyl esters, C1-C8 acrylic acid alkyl esters, and maleic anhydride. The C1-C8 methacrylic acid alkyl esters or C1-C8 acrylic acid alkyl esters are alkyl esters of methacrylic acid or acrylic acid, respectively, and are esters obtained from monohydric alcohol containing 1 to 8 carbon atoms. Specific examples thereof include methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid propyl ester, acrylic acid ethyl ester and acrylic acid methyl ester.

Preferable examples of the rubber-modified vinyl-based graft copolymer include graft-copolymerization of styrene, acrylonitrile and optionally (meth) acrylic acid alkyl ester monomer in the form of a mixture in polybutadiene rubber, acrylic rubber or styrene / butadiene rubber ≪ / RTI >

An example of the most preferred rubber-modified graft copolymer in the present invention is an ABS (acrylonitrile butadiene styrene) graft copolymer.

( c2 ) Acrylic Shell  Including core-shell Graft  Copolymer

The core-shell graft copolymer has a core-shell structure by grafting an unsaturated monomer to the core structure of the rubber to form a hard shell. The core-shell graft copolymer is obtained by polymerizing from a diene monomer, an acrylic monomer, a silicone monomer, Wherein the unsaturated compound comprises at least one acrylic monomer, wherein the unsaturated compound is an acryl-based monomer, a heterocyclic monomer, an aromatic vinyl monomer, an unsaturated nitrile monomer or a combination thereof.

Examples of the diene-based monomer include C4 to C6 butadiene, isoprene, and the like. Of these, butadiene can be used. Specific examples of the rubber polymer obtained by polymerizing the diene monomer include butadiene rubber, acrylic rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber and ethylene-propylene-diene terpolymer (EPDM).

Examples of the acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) ) Acrylate, and the like. At this time, it is preferable to use at least one monomer selected from the group consisting of ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, (Meth) acrylate, triallyl cyanurate and the like can be used.

Examples of the silicon-based monomer include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, octaphenylcyclotetrasiloxane Or a combination thereof. At this time, a curing agent such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane or tetraethoxysilane can be used.

The average particle diameter of the rubbery polymer is preferably 0.05 to 0.5 占 퐉, more preferably 0.07 to 0.15 占 퐉. When the average particle diameter is in the above range, excellent appearance characteristics can be obtained while maintaining proper impact strength.

As the acrylic monomer among the unsaturated compounds, alkyl (meth) acrylate, (meth) acrylic acid ester, or a combination thereof may be used. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl Acrylate and the like. Of these, methyl (meth) acrylate can be preferably used.

The heterocyclic monomers may be substituted or unsubstituted C2 to C20 heterocycloalkyl compounds, substituted or unsubstituted C2 to C20 heterocycloalkenyl compounds, or substituted or unsubstituted C2 to C20 heterocycloalkynyl compounds . Specific examples of the heterocyclic monomers include maleic anhydride, alkyl or phenyl N-substituted maleimide, and the like.

As the aromatic vinyl monomer, styrene, C1 to C10 alkyl-substituted styrene, halogen-substituted styrene, or a combination thereof may be used. Specific examples of the alkyl-substituted styrene include o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, and -methylstyrene.

As the unsaturated nitrile monomer, acrylonitrile, methacrylonitrile, ethacrylonitrile, or a combination thereof may be used. Examples of the polymer formed from at least one monomer among the above unsaturated compounds include polymethyl methacrylate and the like.

Since the copolymer of the core-shell structure aggregates in an empty spherical form on the polycarbonate and polystyrene resin matrix and is positioned on the interface between the polycarbonate resin and the polystyrene resin, the dispersibility is maximized. Therefore, even with a small amount of impact reinforcement, So that the impact can be obtained.

The copolymer of the core-shell structure may be composed of 30 to 80% by weight of the rubbery polymer and 20 to 70% by weight of the grafted unsaturated compound. When the copolymer of the core-shell structure is in the above ratio, it is easy to aggregate into hollow spherical form. Therefore, it is possible to trap toward the surface on the thermoplastic resin matrix having the fluidity due to the polystyrene resin because of its light weight, so that the dispersibility is increased and the impact strength due to the external impact is increased.

In addition, the core-shell structure copolymer may have an average particle size of 0.07 to 1.0 mu m. When the average particle size is within the above range, the dispersion is well dispersed on the polycarbonate and polystyrene resin matrix, so that shock absorption against external impact is facilitated, and the impact reinforcing effect is enhanced.

The most preferred example of the core-shell graft copolymer including the acrylic shell is a methylmethacrylate-butadiene-styrene (MBS) copolymer.

The impact modifier of the present invention may use a rubber-modified vinyl-based graft copolymer (c1) and a core-shell graft copolymer (c2) comprising an acrylic shell in a mixing ratio of 1: 1 to 1: 3. It is possible to achieve an appropriate surface trapping effect in the mixing ratio range, thereby improving the dispersion efficiency.

The impact modifier may be used in an amount of 1 to 30 parts by weight, preferably 3 to 20 parts by weight, more preferably 6 to 15 parts by weight, based on 100 parts by weight of the total composition. The thermoplastic resin composition of the present invention is capable of securing appropriate appearance characteristics, fluidity and impact strength of the resin when the impact reinforcing material is used in such a content range.

(d) Take over Flame retardant

Phosphate, phosphonate, phosphinate, phosphine oxide, phosphazene, metal salts thereof and the like can be used as the phosphorus flame retardant which can be used in the present invention. , Preferably a phosphate-based compound, and more preferably an aromatic phosphate ester compound which is a kind of phosphate compound.

The aromatic phosphoric acid ester compound may have a structure represented by the following formula (2).

(2)

Wherein R ₁ , R ₂ , R ₄ and R ₅ are each independently an aryl group or a C 1 -C 10 alkyl substituted aryl group which is C 6 -C 20 and R ₃ is selected from the group consisting of resorcinol, hydroquinol, bisphenol- S < / RTI > alcohol, and n is 0-5.

I) when n is 0, the aromatic phosphoric ester compound is selected from the group consisting of triphenyl phosphate, tricresyl phosphate, cresyldiphenyl phosphate, triazyl phosphate, tri (2,4,6-trimethylphenyl) (2,6-ditertiary butylphenyl) phosphate, tri (2,6-ditertiarybutylphenyl) phosphate and the like, and ii) when n is 1, resorcinol bis (diphenylphosphate), hydroquinol bis (2, 6-dimethylphenylphosphate), etc., and iii) when n is 2 or more, Or more can be present in the form of a mixture of oligomeric forms. The above-mentioned compounds may be used singly or in combination of two or more, preferably bisphenol A bis (diphenyl phosphate), BDP.

The aromatic phosphoric acid ester compound may be used alone or in combination with other phosphorus flame retardants.

The phosphorus flame retardant (d) may be used in an amount of 1 to 20 parts by weight, preferably 5 to 20 parts by weight, more preferably 10 to 20 parts by weight, per 100 parts by weight of the base resin (a) + (b) To 16 parts by weight. When the phosphorus-based flame retardant is used in such a content range, the thermoplastic resin composition of the present invention can obtain excellent flame retardancy and ensure an appropriate impact strength.

The thermoplastic resin according to the present invention has an impact strength (ASTM D256, 1/8 ") of 45 to 55 kgf · cm / cm and a melt flow index (ISO 1133, 220 ° C., 10 kg) of 100 to 115 g / The flame retardancy (UL94, 2 mm) may be VO.

The flame retardant thermoplastic resin composition of the present invention may further include an additive optionally in accordance with the use. Examples of the additives include antioxidants, nucleating agents, surfactants, coupling agents, fillers, plasticizers, lubricants, antibacterial agents, mold release agents, heat stabilizers, light stabilizers, compatibilizers, inorganic additives, colorants, stabilizers, antistatic agents, pigments, But are not limited thereto, and they may be used alone or in combination.

The flame retardant thermoplastic resin composition of the present invention can be produced in the form of a resin molded article according to a known resin production method. For example, the components of the present invention and other additives may be simultaneously mixed and then melt-extruded in an extruder to produce pellets. Such pellets can be used to produce plastic injection or compression molded articles. The molding method is not particularly limited, and for example, extrusion molding, injection molding, calender molding, vacuum molding, and the like can all be applied.

Since the flame retardant thermoplastic resin composition of the present invention is excellent in flame retardance, gold formation, impact strength, and gloss characteristics, it can be used in various fields such as television, washing machine, cassette player, MP3, DMB, navigation, A telephone, a game machine, an audio player, a monitor, a computer, a printer, a copying machine, and the like.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

[ Example ]

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples. The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Example  1 to 4 and Comparative Example  1-3. Thermoplastic resin manufacturing

The thermoplastic resin compositions according to Examples 1 to 4 and Comparative Examples 1 to 3 were prepared with the compositions shown in Table 1 below. The specific components used in the production of the polycarbonate resin are as follows. The components were mixed in the composition shown in Table 1 below, and extruded in a conventional twin-screw extruder. The extrudate was then pelletized.

(a) Polycarbonate resin (Manufacturer: Cheil Industries)

(1) PC-1: melt index MI (300 DEG C, 1.2 kg, ISO 1133) of 62 g / 10 min

(2) PC-2: A melt index MI of 300 g (1.2 kg, ISO 1133) of 8 g / 10 min was used.

(b) Polystyrene resin (manufactured by Tairirex)

① PS-1: w / o zinc stearate, molecular weight 310,000 g / mol

② PS-2: w / o zinc stearate with a molecular weight of 260,000 g / mol was used.

(c) Impact reinforcement

(1) g-ABS (manufactured by Cheil Industries): 60 parts by weight of butadiene rubber having an average particle diameter of 0.31 mu m, 40 parts by weight of a vinyl-based polymer composed of 75% by weight of styrene and 25% by weight of acrylonitrile, Followed by polymerization to prepare g-ABS.

② MBS (Manufacturer: R & H)

BTA-731 manufactured by R & H Co., Ltd., having an average particle diameter of 100 nm as a rubber polymer, was used.

(d) Take over Flame retardant

BDP: Bisphenol A bis (diphenyl phosphate) produced by Daihachi was used.

* Other additives

0.3 parts by weight of Teflon, 0.3 parts by weight of antioxidant IRGANOX 245, CIBA and 0.2 parts by weight of a lubricant STEARATE series (LEBAX-140B, Lion Chem) were added to 100 parts by weight of the total amount of the thermoplastic resin composition.

* Extrusion conditions

45,, extrusion temperature 240 캜,

BDP was side fed.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 (a) PC-1 (% by weight) 86 87 76 77 91 87 60 PC-2 (% by weight) - - 10 10 5 5 30 (b) PS-1 (% by weight) 10 10 - - - - - PS-2 (% by weight) - - 10 10 - - - (c) g-ABS (wt%) 4 3 4 3 4 8 10 MBS S-573 (phr) 4 6 4 6 - - - BDP (phr) 15 15 15 15 15 15 15

Test Example . Evaluation of thermoplastic resin properties

The properties of the resin specimens prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were measured by the following methods. The results are shown in Table 2 below.

(1) IZOD impact strength: Measured according to ASTM D256 (specimen thickness 1/8 ").

(2) Melt flow index (MI): The melt flow index (g / 10 min) was measured at 220 캜 and 10 kg in accordance with ISO 1133.

(3) Vicat softening temperature (VST): Vicat softening temperature (占 폚) was measured under a load of 5 kg according to ISO R306.

(4) Flame retardancy: The flame retardancy of a 2.0 mm thick specimen was measured according to the UL94 flame retardance specification.

(5) Spiral Flow (S / F): Spiral flow lengths of 2 mm thick specimens were measured at 250 ° C.

(6) Appearance: Milky mark evaluation method. The specimen was injected to quantify the milky marks on the surface. The milky mark determination was visually observed under fluorescent light (20 WX 4) illumination to simulate the Samex local determination conditions, and also observed with an optical microscope. Clouds with holes on the surface during optical microscopic observation were judged by milky mark. mark intensity and area were taken into consideration. The score was 0 for milky mark and 5 for maximum mark intensity. The milky mark acceptance criteria was evaluated by dividing the mold production into three parts, with a maximum of 15 points per sample. These three samples were evaluated by summing up to 45 points. 0 (good) to 45 (poor)

Properties unit Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 IZ (1/8 ") ASTM D256 kgf · cm / cm 45 48 45 53 10 50 60 MI (220 DEG C, 10 kg) ISO 1133 g / 10 min 48 50 50 50 45 48 60 VST (5kg) ISO R306 ℃ 97 96 97 96 100 98 95 Flame retardant (2.0mm) UL94 Rating V-0 V-0 V-0 V-0 V-0 V-0 V-0 S / F (250 DEG C) 2 mm cm 34 36 35 37 28 31 34 Exterior Cheil Method point 10 13 12 15 13 30 40

As shown in Table 2, it was found that the impact strength of the resins of Examples 1 to 4, which were based on PC / PS blend and mixed with g-ABS and MBS as impact modifiers, was remarkably increased as compared with Comparative Example 1 have. In Comparative Example 2-3, although the impact strength was high, the appearance was remarkably decreased. In other words, when the g-ABS alone is applied, the impact strength increases as the g-ABS content increases, but the score of the milky mark increases exponentially. It is considered that this is caused by a decrease in the dispersion of rubber. g-ABS alone, there is a problem in dispersion, but the dispersibility is enhanced due to the effect of PC / PS interfacial trapping when MBS is applied, and in Examples 1 to 4, the rubber content is relatively high, The milky mark score is stabilized. In particular, when comparing the characteristics of the actual flow field, it can be seen that Examples 1 to 4 have an excellent appearance as compared with Comparative Example 3 having high flowability. In Comparative Example 3, the content of the low viscosity PC was relatively high, so that the flow was excellent, but the appearance was greatly reduced.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative and non-restrictive in all respects.

Claims (8)

50 to 95 parts by weight of a polycarbonate resin (a), 1 to 30 parts by weight of a polystyrene resin (b), 1 to 30 parts by weight of an impact reinforcement (c) And 1 to 20 parts by weight of a phosphorus-containing flame retardant (d) based on 100 parts by weight of the base resin (a) + (b) + (c), the thermoplastic resin composition comprising
The polystyrene resin (b) has a weight average molecular weight of 200,000 to 400,000 g / mol,
The impact reinforcing material (c) comprises a rubber-modified vinyl-based graft copolymer (c1) containing a rubbery polymer having an average particle diameter of 0.05 to 0.5 탆 and an acrylic shell containing a rubbery polymer having an average particle diameter of 0.05 to 0.5 탆 Wherein the core-shell graft copolymer (c2) comprises a core-shell graft copolymer (c2).
The method according to claim 1,
Characterized in that the rubber-modified vinyl-based graft copolymer (c1) and the core-shell graft copolymer (c2) comprising an acrylic shell are contained in a mixing ratio of 1: 1 to 1: Resin composition.
The method according to claim 1,
The rubber-modified vinyl-based graft copolymer (c1) is prepared by graft-polymerizing a monomer mixture containing a rubbery polymer, an aromatic vinyl compound and a vinyl cyanide compound.
The method according to claim 1,
The core-shell graft copolymer (c2) comprising the acryl-based shell may be obtained by copolymerizing an acrylic monomer, a heterocyclic monomer, an aromatic vinyl monomer, an aromatic vinyl monomer, and a polyfunctional monomer in a rubbery polymer polymerized from a monomer of a dienic monomer, acrylic monomer, silicone monomer, An unsaturated nitrile monomer or a combination of these unsaturated compounds is grafted;
The flame-retardant thermoplastic resin composition according to claim 1, wherein the unsaturated compound comprises at least one acrylic monomer.
The method according to claim 1,
Wherein the polycarbonate resin has a melt index of 5 to 100 g / 10 min (ISO 1133, 1.2 kg, 300 캜).
The method according to claim 1,
The thermoplastic resin composition has an impact strength (ASTM D256, 1/8 ") of 45 to 55 kgf.cm/cm, a melt flow index (ISO 1133, 220 ° C, 10 kg) of 100 to 115 g / 10 min, UL94, 2 mm) is VO.
The method according to claim 1,
The resin composition can be used as an antioxidant, a nucleating agent, a surfactant, a coupling agent, a filler, a plasticizer, a lubricant, an antibacterial agent, a releasing agent, a heat stabilizer, a light stabilizer, a compatibilizer, an inorganic additive, a colorant, a stabilizer, an antistatic agent, Wherein the flame retardant thermoplastic resin composition further comprises at least one additive selected from the group consisting of the flame retardant thermoplastic resin composition.
A molded article obtained by molding the flame-retardant thermoplastic resin composition according to any one of claims 1 to 7.