KR100340998B1 - Flame Retardant Thermoplastic Resin Composition - Google Patents

Abstract

Flame retardant thermoplastic resin composition of the present invention (A) 45 to 99 parts by weight of a polycarbonate resin; (B) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, or mixtures thereof and acryl Ronitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimides, or mixtures thereof 5 5 to 95 parts by weight of a mixture with -50 parts by weight of butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber having a glass transition temperature (T _G ) of -10 ° C. or less, Rubber modified graft grafted to 5 to 95 parts by weight of one or a mixture thereof selected from the group consisting of ethylene-propylene-diene terpolymer (EPDM) and a polyorganosiloxane / polyalkyl (meth) acrylate rubber composite 1 to 50 parts by weight of the polymer resin; And (C) an organic derivative derived from alkylene diols containing an ether group (D) based on 100 parts by weight of the base resin (A) + (B) + (C) composed of 0 to 50 parts by weight of a vinyl copolymer resin. 0.5 to 30 parts by weight of a phosphate ester flame retardant composed of 10 to 90% by weight of a phosphorus compound and 10 to 90% by weight of a monophosphate; And (E) 0.05 to 5 parts by weight of one or more flame retardants and flame retardant aids selected from the group consisting of other organic phosphate ester compounds, halogen-containing organic compounds, cyanurate compounds, fluorinated polyethylene resins, and metal salts.

Description

Flame Retardant Thermoplastic Resin Composition

Field of invention

The present invention relates to a thermoplastic resin composition having flame retardancy. More specifically, the present invention relates to a thermoplastic resin composition having flame retardancy composed of polycarbonate resin, rubber modified graft copolymer, vinyl copolymer, phosphate ester flame retardant and other flame retardant aids.

Background of the Invention

Polycarbonate resins are excellent in transparency, mechanical strength as well as heat resistance, and are widely used in applications such as electric, electronic products, and automobile parts. However, polycarbonate resins are used in combination with other types of resins due to their low notch impact strength and poor processability. For example, blends of polycarbonate / styrene-containing copolymers have improved notch impact strength while maintaining high notch impact strength. It can be referred to as a resin mixture. In addition, such a polycarbonate resin composition is usually applied to a large heat dissipation such as a computer housing or other office equipment, it is essential to maintain the flame retardancy and high mechanical strength. In addition, in recent years, in accordance with the trend of miniaturization and weight reduction of electrical and electronic products, the moldability of the resin composition is emerging as a major factor according to the thinning of electrical and electronic products.

In order to impart flame retardance to such a resin composition, a halogen-based flame retardant and an antimony compound have conventionally been used. U.S. Patent Nos. 4,983,658 and 4,883,835 disclose examples of using halogen containing compounds as flame retardants. However, when halogen-based flame retardants are used, the demand for resins that do not contain halogen-based flame retardants has been rapidly expanded recently due to the problem of human health of gases generated during combustion.

As a technique for imparting flame retardancy without using a halogen-based flame retardant, the most widely applied method is to use a phosphate ester flame retardant. U.S. Patent No. 4,692,488 discloses thermoplastic resin compositions consisting of non-halogen aromatic polycarbonate resins, non-halogen SAN (styrene acrylonitrile) copolymers, non-halogen phosphorus compounds, tetra fluoroethylene copolymers and small amounts of ABS copolymers. . Thus, when the phosphorus compound and the fluorinated alkane polymer are used to impart flame retardancy to the PC / ABS blend resin composition, it is possible to prevent the dropping of the spark that occurs during combustion, but the resin composition has a flame retardant during molding. There is a problem that a surface crack occurs due to the bleeding phenomenon to move to.

U.S. Patent No. 5,061,745 discloses a flame retardant resin composition composed of an aromatic polycarbonate resin, an ABS graft copolymer, a copolymer and a monomeric phosphate ester. The composition has excellent flowability and excellent moldability, but may cause surface crack problems due to bleeding due to volatilization of monomeric phosphate esters, and has a disadvantage in that heat resistance is severely degraded.

Japanese Patent Laid-Open No. 59-202,240 uses oligomers of phosphate esters as flame retardants in polyamide or polycarbonate resins.

U.S. Patent 5,204,394 discloses a flame retardant resin composition composed of an aromatic polycarbonate resin, a styrene-containing copolymer or a graft copolymer, and a phosphate ester oligomer having an aromatic compound as a link. In this case, the bleeding phenomenon is reduced compared to the case of using the monomeric phosphate ester as a flame retardant, and shows an excellent heat deformation temperature, but the fluidity is lowered, which is disadvantageous for molding the thin housing.

In contrast, the present inventors exhibited excellent flame retardancy and heat distortion temperature by using a phosphate ester compound composed of a mixture of polyphosphates derived from alkylene diols containing monophosphate and ether bonds as a flame retardant to overcome the above problems. The bleeding does not occur during the molding and excellent fluidity has led to the development of a flame retardant thermoplastic resin composition suitable for molding a thin housing.

An object of the present invention is to provide a thermoplastic resin composition excellent in mechanical properties, heat resistance and flame retardancy.

Another object of the present invention is to provide a flame retardant thermoplastic resin composition having excellent heat deflection temperature.

Still another object of the present invention is to provide a flame retardant thermoplastic resin composition in which bleeding does not occur during molding.

Another object of the present invention is to provide a flame retardant thermoplastic resin composition excellent in fluidity and suitable for forming a thin housing of an electric and electronic product.

The above and other objects of the present invention can be achieved by the present invention described below.

The thermoplastic resin composition having flame retardancy of the present invention is (A) polycarbonate resin, (B) rubber modified graft copolymer resin, (C) vinyl copolymer resin, (D) phosphate ester compound, and (E) other flame retardant It consists of a preparation and the detailed component about each of these components is as follows.

(A) polycarbonate resin

The polycarbonate resin of the present invention is prepared by reacting diphenols represented by the following general formula (1) with phosgene, halogen formate or diester carbonate as an aromatic polycarbonate containing no halogen:

(Wherein A is a single bond, C _1-5 alkylene, C _2-5 alkylidene, C _5-6 cycloalkylidene, S or SO ₂ ).

Examples of the diphenols represented by the formula (1) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis- (4-hydroxyphenyl) -propane, and 2,4-bis- (4-hydroxyphenyl) -2-methylbutane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2-bis- (3-chloro-4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane etc. are mentioned. Among them, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, 1,1-bis- (4- Hydroxyphenyl) -cyclohexane and the like. Most preferred is 2,2'-bis- (4-hydroxyphenyl) -propane, also called bisphenol-A.

The polycarbonate resin (A) of the present invention has a weight average molecular weight (M _w ) of 10,000 to 200,000, preferably 15,000 to 80,000. The branched polycarbonate resin may be used, and preferably, may be prepared by adding a compound having 0.05 to 2 mol% of a trivalent or more phenol group based on the total amount of diphenols used in the polymerization. The polycarbonate (PC) used in the preparation of the resin composition of the present invention may be used in the form of a homopolymer, a copolymer, or a mixture thereof. In addition, the polycarbonate resin (A) may be used in part or in whole by an aromatic polyester-carbonate resin obtained by polymerizing in the presence of a bifunctional carboxylic acid which is an ester precursor.

The polycarbonate resin (A) together with the rubber modified graft copolymer (B) and / or the vinyl copolymer (C) constitutes a base resin, and is used in the range of 45 to 99 parts by weight in the base resin.

(B) rubber modified graft copolymer resin

The rubber-modified graft copolymer resin used in the present invention is styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, or 50-95 parts by weight of a mixture thereof, acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N -Substituted maleimide, or 5 to 95 parts by weight of the mixture with 5 to 50 parts by weight of a mixture thereof Butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber having a glass transition temperature (T _G ) of -10 ° C. or less, One or their selected from the group consisting of acrylonitrile / butadiene rubber, isoprene rubber, ethylene-propylene-diene terpolymer (EPDM), and polyorganosiloxane / polyalkyl (meth) acrylate rubber composites A graft copolymer in which 5 to 95 parts by weight of the compound. The C _1-8 methacrylic acid alkyl esters are monohydryl alcohols containing 1 to 8 carbon atoms as esters of methacrylic acid. Preferred examples include methacrylic acid methyl ester, methacrylic acid ethyl ester, or methacrylic acid propyl ester, most preferably methacrylic acid methyl ester.

The graft copolymer resin may be prepared by a conventional polymerization method, but is preferably one synthesized by emulsion polymerization and bulk polymerization. Acrylonitrile / butadiene / styrene (ABS) resins in which acrylonitrile and styrene are grafted to butadiene rubber are widely used.

The rubber modified graft copolymer is used in the range of 1 to 50 parts by weight of the total base resin. When preparing the graft copolymer, the average size of the rubber particles is suitably in the range of 0.05 to 4 μm in consideration of impact strength and appearance.

(C) vinyl copolymer resin

Vinyl copolymers used in the present invention are styrene, α-methylstyrene, ring-substituted styrene, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, or mixtures thereof 50-95 Parts by weight with acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 acrylic acid alkyl esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimides, or these The vinyl copolymer obtained by copolymerizing 5-50 weight part of mixtures of these, or a mixture of these copolymers. This vinyl copolymer resin is used in 0-50 weight part of all the base resin.

Vinyl-based copolymers may be produced as by-products in the preparation of rubber-modified graft copolymers (B), especially when grafting excess vinyl-based monomers to small amounts of rubbery polymers. The content of the vinyl copolymer (C) used in the preparation of the resin composition of the present invention does not include by-products generated during the production of the graft copolymer (B). That is, the copolymer (C) used for manufacture of the resin composition of this invention is a thermoplastic resin and does not contain rubber | gum.

As a preferable specific example of the said vinyl copolymer (C), it is manufactured by emulsion polymerization, suspension polymerization, solution polymerization, or block polymerization using methacrylic acid methyl ester and / or acrylic acid methyl ester.

Other specific examples of the vinyl copolymer (C) include monomer mixtures of styrene and acrylonitrile and optionally methacrylic acid methyl ester, monomer mixtures of α-methylstyrene and acrylonitrile and optionally methacrylic acid methyl ester, or Styrene and α-methylstyrene and acrylonitrile and optionally from a monomer mixture of methacrylic acid methylester. The styrene / acrylonitrile copolymer may be prepared by emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization, and it is preferable to use a weight average molecular weight (M _w ) of 15,000 to 200,000.

Another specific example of the vinyl copolymer (C) is a copolymer of styrene and maleic anhydride, which may be prepared using a continuous bulk polymerization method and a solution polymerization method. In this case, the component composition ratio of styrene and maleic anhydride can be varied in a wide range, and the content of maleic anhydride is preferably 5 to 25 parts by weight. The styrene / maleic anhydride copolymer may be used in a wide range of 60,000 to 200,000 weight average molecular weight, and it is preferable to use an intrinsic viscosity of 0.3 to 0.9.

As the styrene monomer used in the preparation of the vinyl copolymer (C) of the present invention, other substituted styrene monomers such as p-methylstyrene, vinyltoluene, 2,4-dimethylstyrene and α-methylstyrene may be used.

The vinyl-based copolymers (C) described above can also be used alone or in mixture of two or more thereof.

(D) Phosphoric Acid Ester Compound

Phosphoric acid ester compound used in the present invention is composed of 10 to 90% by weight of an organophosphorus compound derived from alkylene diols containing ether group and 10 to 90% by weight of monophosphate, wherein the organophosphorus compound is 10% by weight If less, there is a problem that bleeding occurs during molding, and if it exceeds 90% by weight, the fluidity and mechanical properties of the final resin composition is lowered, which is not suitable for thin molding. The phosphate ester compound is used as a flame retardant in the thermoplastic resin composition of the present invention, it is preferable to use 0.5 to 30 parts by weight based on 100 parts by weight of the base resin.

The phosphate ester compound derived from the alkylene diols containing the ether group has the structure of formula (2)

In the above formula, R ₁ , R ₂ , R ₅ , and R ₆ are each C _6-20 aryl groups, R ₃ , R ₄ are each C _1-5 alkylene groups, and n is an integer of 1 to 5.

Preferred R ₁ , R ₂ , R ₄ and R ₅ are phenyl groups or phenyl groups substituted with alkyl groups such as t-butyl, isopropyl, isobutyl, isoamyl and t-amyl.

Examples of R ₃ and R ₄ are methylene group, ethylene group, propylene group, isopropylene group, butylene group, pentylene group and isopentylene group, respectively. Neopentylene group etc. are preferable, Ethylene group is preferable.

The monophosphate constituting the flame retardant together with the phosphate ester compound derived from alkylene diols containing the ether group is represented by the following formula:

In the above formula, R ₇ , R ₈ , R ₉ are C _6-20 aryl or C _6-20 aryl groups substituted with alkyl or hydroxyl groups, respectively. Preferred examples of R ₇ , R ₈ , R ₉ include phenyl group, cresyl group, diphenyl-2-ethyl cresylphosphate, tri- (isopropylphenyl) -phosphate, and the like, and most preferably, phenyl group.

(E) other flame retardants and flame retardants

The thermoplastic resin composition of the present invention may be added one or more flame retardants and flame retardants selected from the group consisting of an organic phosphate ester compound, a halogen-containing organic compound, a cyanate compound, a fluorinated polyethylene resin, and a metal salt to improve flame retardancy.

Fluorinated polyolefin resins are conventionally available resins as polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, tetrafluoroethylene / hexafluoropropylene copolymer or ethylene / Tetrafluoroethylene copolymers. These may be used independently of each other, or a mixture of two or more different types may be used. Most preferably polytetrafluoroethylene having a particle size of 0.05-1,000 μm and specific gravity 2.0-2.3 g / cm ² . The usage-amount of fluorinated polyolefin resin is 0.05-5 weight part with respect to 100 weight part of base resins.

The fluorinated polyolefin resin may be prepared using a known polymerization method, for example, sodium at a pressure of 7 to 71 kg / cm ² and a temperature of 0 to 200 ℃, preferably at a temperature of 20 to 100 ℃ It can be prepared in an aqueous medium containing a free radical forming catalyst such as potassium or ammonium peroxydisulfate. When the fluorinated polyolefin resin is mixed with the other constituent resins of the present invention and extruded, the fluorinated polyolefin resin forms a fibrillar network in the resin to lower the flow viscosity of the resin during combustion and increase the shrinkage rate so that the resin is dropped. Prevent the phenomenon. The resin may be used in an emulsion state or a powder state. However, in the case of using the fluorinated polyolefin resin in the emulsion state, the dispersibility in the entire resin composition is good, but there is a disadvantage that the manufacturing process is complicated. Therefore, even if it is powder state, if it can disperse | distribute suitably in whole resin composition and can form a fibrous network, it is preferable to use it in powder state.

Metal salts are conventionally used, and any suitable one for polycarbonate may be used, and preferred examples thereof include sodium trichlorobenzenesulfonate, diphenylsulfon potassium salt, alkane sulfonate or sodium ammonium hexafluoride. The usage-amount of a metal salt is 0.01-1 weight part with respect to 100 weight part of base resins.

In addition, the thermoplastic resin composition of the present invention is mixed in a conventional mixer after adding a lubricant, a releasing agent, a nucleating agent, an antistatic agent, a stabilizer, a reinforcing agent, an inorganic additive, a pigment and / or a dye according to each use. This mixture is prepared into a resin composition in pellet form through an extruder. At this time, the inorganic additives added may include asbestos, glass fibers, talc and ceramics, which may be used in the range of 0 to 60 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the base resin.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

(A) polycarbonate resin, (B) rubber modified graft copolymer resin, (C) vinyl-based copolymer resin, (D) organophosphorus compound and (E) fluorinated polyolefin used in the following examples and comparative examples The specification of system resin is as follows.

(A) polycarbonate resin

A bicarbonate-type polycarbonate having a melt flow index (250 ° C., 10 kg load) measured by ASTM D1238 of 20 g / 10 min was used.

(B) rubber modified graft copolymer resin

Butadiene rubber latex was added so that the butadiene content was 45 parts by weight based on the whole monomer, 1.0 parts by weight of potassium oleate, cumene hydroperoxide, which was an additive necessary for a mixture of 36 parts by weight of styrene, 14 parts by weight of acrylonitrile, and 150 parts by weight of deionized water. 0.4 parts by weight, 0.3 parts by weight of mercaptan-based chain transfer agent was added to the reaction while maintaining at 75 ℃ for 5 hours to prepare a g-ABS latex. 1% sulfuric acid solution was added to the resultant polymer latex to coagulate and dried to prepare a graft ABS copolymer resin in powder form.

(C) vinyl copolymer resin

A SAN copolymer resin was prepared by suspension polymerization by adding 0.2 parts by weight of azobisisobutyronitrile and 0.5 parts by weight of tricalcium phosphate, which are necessary additives to a mixture of 70 parts by weight of styrene, 30 parts by weight of acrylonitrile, and 120 parts by weight of deionized water. . The copolymer was washed with water, dehydrated and dried to obtain a SAN copolymer resin in powder form.

(D) organophosphorus compounds

(d ₁ ) An phosphate ester compound derived from alkylene diols containing ether groups, wherein n is 1.1, R ₁ , R ₂ , R ₅ , and R ₆ are phenyl groups, and R ₃ and R ₄ are each an ethylene group. Phosphorus compound.

(d ₂ ) Triphenylphosphate was used as monophosphate.

(d ₃ ) Bisphenol bis (diphenylphosphate) having an average number of phosphorus per molecule of 2.1 was used as the organic phosphate ester compound.

(E) fluorinated polyolefin resin

Teflon (trade name) 7AJ of Dupont, USA was used.

The composition and measured physical properties of each component used in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1. Examples 1 and 2 use a mixture of a phosphate ester compound and triphenyl phosphate derived from alkylene diols containing an ether group as a flame retardant, Comparative Example 1 is only triphenyl phosphate, Comparative Example 2 is a triphenyl phosphate Mixtures of bisphenol bis (diphenylphosphate) were used as flame retardants, respectively.

As shown in Table 1, each component was mixed, antioxidant and heat stabilizer were added, and then mixed in a conventional mixer and extruded using a twin screw extruder of L / D 35 and Φ 45 mm. Mixed extrusion was prepared in a resin composition in the form of pellets, and specimens for physical property measurement and flame retardancy evaluation were prepared at an injection temperature of 250 ° C. These specimens were measured for 48 hours at 23 ° C. and 50% relative humidity, and then measured for physical properties according to ASTM standards.

Izod impact strength was evaluated using a 3.2 mm thick, V-notched specimen according to ASTM D256, and the heat deflection temperature was measured at 18.6 kgf load according to ASTM D648. Melt flow index was evaluated according to ASTM D1238. Was evaluated at 220 ° C., 10 kg load. Flame retardancy was evaluated using a 2.12 mm thick specimen in accordance with UL94 regulations. Bleeding was evaluated by visually observing the surface of the injection molded product by injecting a container of 200 x 200 x 100 mm, thickness 3 mm using a 40-ounce injection machine.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 ingredient (A) polycarbonate 78 80 78 78 (B) g-ABS 12 10 12 12 (C) SAN resin 10 10 10 10 (D) (d ₁ ) Organic Phosphorus Compound 5 10 - - (d ₂ ) triphenyl phosphate 10 7 15 10 (d ₃ ) bisphenol bis (diphenyl phosphate) - - - 5 (E) PTFE 0.5 0.5 0.5 0.5 Properties Izod impact strength (kgfcm / cm) 56 53 52 51 Heat deflection temperature (℃) 75 76 69 76 Melt Flow Index (g / 10min) 36 39 38 31 Flame retardant (UL Class) V-0 V-0 V-0 V-0 Bleeding ○ ○ × ○

* ○: No bleeding. ×: bleeding occurs.

As can be seen in Examples 1 and 2 of Table 1 and Comparative Examples 1 and 2, when using the flame retardant of the present invention, there is no bleeding and excellent moldability while maintaining excellent heat resistance.

The present invention uses a mixture of monophosphate and phosphate esters derived from alkylene diols containing ether groups as a flame retardant, so that the mechanical properties including flame retardancy, heat resistance and impact strength are excellent, and fluidity is very high without bleeding. It is excellent in having the effect of providing a flame retardant thermoplastic resin composition useful for producing thin molded articles such as the housing of computers or notebooks.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (6)

(A) 45-99 parts by weight of polycarbonate resin; (B) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, or mixtures thereof and acryl Ronitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 methacrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimides, or mixtures thereof 5 5 to 95 parts by weight of a mixture with -50 parts by weight of butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber having a glass transition temperature (T _G ) of -10 ° C. or less, Rubber modified graft grafted to 5 to 95 parts by weight of one or a mixture thereof selected from the group consisting of ethylene-propylene-diene terpolymer (EPDM) and a polyorganosiloxane / polyalkyl (meth) acrylate rubber composite 1 to 50 parts by weight of the polymer resin; And (C) 100 parts by weight of the base resin (A) + (B) + (C) composed of 0 to 50 parts by weight of the vinyl copolymer resin; (D) 0.5 to 30 parts by weight of a phosphorus flame retardant composed of 10 to 90% by weight of an organophosphorous compound derived from alkylene diols containing ether groups and 10 to 90% by weight of monophosphate; And 0.05 to 5 parts by weight of one or more flame retardants and flame retardants selected from the group consisting of (E) an organic phosphate ester compound, a halogen-containing organic compound, a cyanate compound, a fluorinated polyethylene-based resin, and a metal salt; Flame-retardant thermoplastic resin composition, characterized in that consisting of. The flame retardant thermoplastic resin composition according to claim 1, wherein the organic phosphorus compound derived from alkylene diols containing ether groups is represented by the following Chemical Formula 2. Formula 2 (Wherein R ₁ , R ₂ , R ₅ , R ₆ are each C _6-20 aryl groups, R ₃ , R ₄ are each C _1-5 alkylene groups, n is an integer from 1 to 5) 3. A compound according to claim 2, wherein R ₁ , R ₂ , R ₅ and R ₆ are each a phenyl group or a phenyl group substituted with a methyl group or a hydroxy group, and R ₃ and R ₄ are a methylene group, an ethylene group, a propylene group and an isopropylene group. , Butylene group, pentylene group, isopentylene group. Flame retardant thermoplastic resin composition, characterized in that one or more mixtures selected from the group consisting of neopentylene group. The flame-retardant thermoplastic resin composition according to claim 2, wherein the average value of n is 0.1 to 3.0. The flame retardant thermoplastic resin composition of claim 1, wherein the monophosphate is represented by the following Chemical Formula 3. Formula 3 (Wherein R ₇ , R ₈ , R ₉ are each C _6-20 aryl or C _6-20 aryl group substituted with alkyl or hydroxyl group) The flame retardant thermoplastic resin composition according to claim 5, wherein R ₇ , R ₈ and R ₉ are each a phenyl group or a phenyl group substituted with a methyl group or a hydroxy group.