KR20000043581A - Flame-retardant thermoplastic resin composition having improved weather resistance - Google Patents

Abstract

PURPOSE: A thermoplastic resin composition having improved weather resistance is provided which is excellent in mechanical property, heat resistance and flame retardancy and generates no environmental pollution during processing and combustion. CONSTITUTION: A resin composition comprises 100 parts by weight of a base resin consisting of 40 to 95% by weight of a rubber modified styrene-based resin and 60 to 5% by weight of a polyphenyleneether resin; 2 to 20 parts by weight of a styrene-acrylonitrile copolymer containing 5 to 10% by weight of acrylonitrile; 5 to 30 parts by weight of an aromatic ester phosphate compound having a melting point of above 90°C; 3 to 20 parts by weight of bis(4-hydroxyphenyl)sulfon; and 0 to 20 parts by weight of a phenol resin. The composition exhibits an excellent flame retardancy without blending a halogen compound with a rubber modified styrene-based resin.

Description

Flame retardant thermoplastic resin composition with improved weatherability

Field of invention

The present invention relates to a thermoplastic resin composition having flame retardancy. More specifically, the present invention uses a styrene-acrylonitrile copolymer containing 5-18% by weight of acrylonitrile as a compatibilizer and using a rubber modified styrene resin and a polyphenylene ether resin as a base resin. It relates to a thermoplastic resin composition having a flame retardancy in which an aromatic phosphate ester compound having a melting point of 90 ° C. or more is applied and bis (4-hydroxyphenyl) sulfone and a phenol resin are added as a flame retardant aid.

Background of the Invention

Rubber modified styrene resins have been widely applied to various applications such as electrical appliances and office equipment because of their good processability, excellent physical properties, particularly impact strength and good appearance. However, since rubber-modified styrene resins are combustible, when applied to heat-dissipating products such as personal computers or fax machines, flame retardancy is required.

The most widely known flame retardant method is to impart flame retardant properties by applying a halogen-based compound and an antimony-based compound together to the rubber-modified styrene resin. As the halogen-based compound, polybromodiphenyl ether, tetrabromobisphenol A, a brominated substituted epoxy compound, chlorinated polyethylene and the like are mainly used. Antimony trioxide and antimony pentoxide are mainly used as an antimony compound.

The method of applying the halogen and antimony compound together to impart flame retardancy is easy to secure flame retardancy and hardly deteriorates the physical properties.However, the hydrogen halide gas generated during processing may damage the mold. The generation of such gas at the time of combustion is likely to have a fatal effect on the human body. In particular, polybrominated diphenyl ethers, which are mainly halogen-based flame retardants, have a high possibility of generating very toxic gases such as dioxins and difurans during combustion. .

As a flame retardant that does not contain halogen, a method of imparting flame retardancy to a resin composition by adding a compound such as phosphorus or nitrogen has been researched. However, the phosphorus compound alone has a disadvantage of lowering the heat resistance of the rubber-modified styrene resin and insufficient flame retardancy. Its application is limited.

In general, rubber-modified styrene resins, particularly acrylonitrile-butadiene-styrene copolymer (ABS) resins, are hardly expected to have a flame retardant effect in a solid phase because almost all parts are decomposed and vaporized during combustion. (Journal of Applied Polymer Science, 1998, vol 68, p 1067). Therefore, a high flame retardancy can be obtained by adding a char forming agent so that the char can be produced smoothly. Char forming agent forms a 3D carbon chain bond to the surface of the rubber molecule during combustion to effectively form a char to block the entry of oxygen from the outside and the inner rotor to prevent the release of fuel (fuel). Polycarbonate, polyphenylene ether, phenol resin, etc. are known as resin which forms a char well.

U.S. Patent Nos. 4,692,488 and 5,204,394 apply a aromatic phosphate ester compound to a blend of polycarbonate and acrylonitrile-styrene-butadiene resin and add polytetrafluoroethylene to produce a resin composition having flame retardancy of UL94 V-0. Although disclosed, the polycarbonate content of 60 parts by weight or less due to the nature of the added aromatic phosphate ester itself has a disadvantage of difficult to obtain the flame retardant properties of V-0 or V-1.

Japanese Patent Application Laid-open No. Hei 7-48491 discloses a thermoplastic flame retardant resin in which a phenolic resin, a phosphate ester, and a red phenol resin are added to a thermoplastic copolymer resin of a rubbery polymer and an aromatic vinyl monomer. However, it is difficult to secure the flame retardancy of UL94 V-0 or V-1, and it is very difficult to secure the practical heat resistance due to the rapid decrease in the heat resistance. This is because phenolic resin not only lowers the heat resistance of rubber-modified styrene resin (ABS) but also lacks char forming ability, so that a relatively large amount of phosphate ester and novolak phenolic resin should be added to obtain desired flame retardancy. This is because the degree is further lowered.

Therefore, the present inventors blended polyphenylene ether resin with rubber-modified styrene resin and used it as a base resin to solve the problems of the existing flame retardant thermoplastic resin, and the styrene-acrylonitrile having an acrylonitrile content of 5 to 18% by weight. The copolymer resin is used as a compatibilizer to prevent mechanical property deterioration of the resin composition, and the aromatic phosphate ester compound is used as a flame retardant, and bis (4-hydroxyphenyl) sulfone and phenol resin are used as flame retardant aids, thereby providing excellent flame resistance and weather resistance. There is a need to develop improved thermoplastic resin compositions.

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 thermoplastic resin composition having improved weather resistance.

Another object of the present invention is to provide a thermoplastic resin composition having a flame retardancy not containing a halogen compound that causes environmental pollution during processing or combustion of the resin.

The above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

The resin composition of the present invention is a base resin (A) consisting of a rubber-modified styrene resin (a ₁ ) and a polyphenylene ether resin (a ₂ ), with an acrylonitrile content of 5-18 to 100 parts by weight of the base resin. 2 to 20 parts by weight of the styrene-acrylonitrile copolymer (B) which is% by weight, 5 to 30 parts by weight of an aromatic phosphate ester compound (C) having a melting point of 90 ° C. or more, bis (4-hydroxyphenyl) sulfone (D) 3 It consists of -20 weight part and 0-20 weight part of phenol resins (E).

Hereinafter, each component of the resin composition of the present invention will be described in detail.

(A) Basic resin

The base resin in this invention mixes 40-95 weight% of rubber modified styrene resin, and 60-5 weight% of polyphenylene ether resin.

(a ₁ ) Rubber modified styrene resin

Rubber modified styrene resin refers to a polymer in which a rubber polymer is dispersed in the form of particles in a matrix (continuous phase) made of an aromatic vinyl polymer, and is capable of copolymerizing with an aromatic vinyl monomer in the presence of a rubber polymer and a vinyl polymer. It is prepared by adding and polymerizing monomers.

Such rubber-modified styrene-based resins can be prepared by known polymerization methods such as emulsion polymerization, suspension polymerization or bulk polymerization, and are usually produced by mixing and extruding styrene-containing graft copolymer resin and styrene-containing copolymer resin. In the case of bulk polymerization, the rubber-modified styrene resin is produced by only one step reaction without producing the styrene-containing graft copolymer resin and the styrene-containing copolymer resin separately, but in any case, the rubber content of the final rubber-modified styrene resin component is It is suitable that it is 5-30 weight part with respect to the whole resin.

Examples of such resins include acrylonitrile-butadiene-styrene copolymer resins (ABS), acrylonitrile-acryl rubber-styrene copolymer resins (AAS), acrylonitrile-ethylenepropylene rubber-styrene copolymers (AES) resins, and the like. There is this.

The resin may be used alone or in combination with the styrene-containing graft copolymer resin and styrene-containing graft copolymer resin and styrene-containing copolymer resin, it is preferable to combine the resin in consideration of each compatibility. The present invention uses a mixture of a styrene-containing graft copolymer resin (a ₁₁₎ styrene-containing copolymer resin (a ₁₂₎ of 0 to 80% by weight of 20-100% by weight.

(a ₁₁ ) Styrene-containing graft copolymer resin

Examples of the rubber used for the production of the styrene-containing graft copolymer resin include diene rubbers such as polybutadiene, poly (styrene-butadiene), and poly (acrylonitrile-butadiene); Saturated rubber hydrogenated to the diene rubber; Acrylic rubbers such as isoprene rubber, chloroprene rubber, and butyl polyacrylate; And ethylene-propylene-diene monomer terpolymer (EPDM) and the like, but diene rubber is preferred, and more preferably butadiene rubber is suitable.

As the aromatic vinyl monomer in the graft polymerizable monomer mixture, styrene, α-methyl styrene, p-methyl styrene, and the like may be used. Of these, styrene is most preferable, and a monomer copolymerizable with the aromatic vinyl monomer may be used. Apply by introducing one or more. Preferable monomers include vinyl cyanide compounds such as acrylonitrile and unsaturated nitrile compounds such as methacrylonitrile.

In the styrene-containing graft copolymer resin, the rubber is contained in an amount of 10 to 60 parts by weight, and the amount of the aromatic vinyl monomer such as styrene is 30 to 70 parts by weight in the components of the monomer grafted to the rubber. It is preferable that the quantity of a vinyl type or an unsaturated nitrile type monomer is 10-30 weight part.

In addition, graft polymerization may be performed by adding monomers such as acrylic acid, methacrylic acid, maleic anhydride, and N-substituted maleimide to impart properties such as workability and heat resistance. The amount added is in the range of 0 to 20 parts by weight based on the styrene-containing graft copolymer resin.

In preparing the styrene-containing graft copolymer, in consideration of impact strength and appearance, the average size of the rubber particles is preferably in the range of 0.1 to 4 μm.

(a ₁₂ ) Styrene-containing copolymer resin

Styrene-containing copolymer resin is prepared according to the monomer ratio and compatibility among the components of the styrene-containing graft copolymer resin prepared in the above composition except rubber, the components are as follows.

As the aromatic vinyl monomer to be copolymerized, styrene, α-methyl styrene, p-methyl styrene, etc. may be used. Among them, styrene is the most preferable, and the weight of the aromatic vinyl monomer in the entire component of the copolymer resin is 60 to 80 parts by weight. Corresponding. One or more monomers copolymerizable with the aromatic vinyl monomers may be introduced and applied thereto. As a monomer which can be introduced, a vinyl cyanide compound such as acrylonitrile and an unsaturated nitrile compound such as methacrylonitrile are preferable, and 40 to 20 parts by weight of the components of the entire copolymer are introduced. Furthermore, 0-40 weight part of monomers, such as acrylic acid, methacrylic acid, maleic anhydride, and N-substituted maleimide, can also be added and copolymerized here.

(a ₂ ) polyphenylene ether resin

The rubber-modified styrene resin alone is used as a base resin by adding polyphenylene ether resin because it is insufficient in flame retardancy and degrades rigidity and heat resistance. Such compounds include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-dipropyl-1,4 -Phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2-ethyl- 6-propyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene) ether and poly (2 Copolymers of 3,6-trimethyl-1,4-phenylene) ether and poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3,5-triethyl-1, Copolymers of 4-phenylene) ether. Preferably a copolymer of poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3,6-trimethyl-1,4-phenylene) ether and poly (2,6-dimethyl- 1,4-phenylene) ether is used, of which poly (2,6-dimethyl-1,4-phenylene) ether is most preferred.

Although the polymerization degree of polyphenylene ether is not specifically limited, It is preferable that the intrinsic viscosity measured in 25 degreeC chloroform solvent is 0.2-0.8 in consideration of the thermal stability and workability of a resin composition.

(B) styrene-acrylonitrile copolymer having 5 to 18% by weight of acrylonitrile

The styrene-acrylonitrile copolymer is a polymer added to improve the compatibility of the rubber-modified styrene resin (a ₁ ) and the polyphenylene ether resin (a ₂ ) used as the base resin. In general, the compatibility of the blend of the rubber modified styrene resin and the polyphenylene ether resin is affected by the content of acrylonitrile. That is, when the content of acrylonitrile in the styrene-acrylonitrile polymer except for the rubber part is in the range of 5 to 18% by weight, there is some compatibility, but when it exceeds this range, there is no compatibility. It shows the characteristic that a physical property falls.

In the present invention, a styrene-acrylonitrile copolymer in which 5 to 18% by weight of acrylonitrile is polymerized in 82 to 95% by weight of styrene is used. The styrene-acrylonitrile copolymer is prepared by emulsion polymerization, suspension polymerization, and bulk polymerization, and preferably has a weight average molecular weight of 50,000 to 300,000.

The amount of the styrene-acrylonitrile copolymer used is 2 to 20 parts by weight based on 100 parts by weight of the base resin mixed with the rubber modified styrene resin and the polyphenylene ether resin.

(C) Aromatic Phosphate Ester Compounds

In the present invention, a phosphate ester compound represented by Formula 1 is used:

In Formula 1, R ₁ , R _2, and R ₃ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, and X is from dial alcohols such as resorcinol, diphenol, hydroquinol, bisphenol-A, and bisphenol-S. Derived and N has a value of 0-4.

Examples of the compound represented by Chemical Formula 1 include tri (2,6-dimethylphenyl) phosphate, tri (2,4,6-trimethylphenyl) phosphate, and tri (2,4-dibutylbutylphenyl) when the N value is 0. Phosphate, tri (2,6-dibutylbutylphenyl) phosphate and the like, when the N value is 1, resorcinol bis (2,6-dimethylphenyl) phosphate, resorcinol bis (2,4-diary) Butylphenyl) phosphate, hydroquinol (2,6-dimethylphenyl) phosphate, hydroquinol (2,4-dibutylbutylphenyl) phosphate and the like are typical examples. These may be used alone or mixtures thereof may be used.

In the present invention, a phosphate ester compound represented by the following Chemical Formula 2 having phloroglucinol as a skeleton may also be used:

In Formula 2, R ₄ , R _5, and R ₆ are hydrogen or an alkyl group having 1 to 4 carbon atoms.

Examples of the compound represented by Formula 2 include 1,3,5-tri (diphenylphosphate) fluoroglucinol, 1,3,5-tri (dicresylphosphate) fluoroglucinol, 1,3,5 -Tri (designinylphosphate) fluoroglucinol and the like.

Phosphoric acid ester having the above formula may be applied singly or mixed, but it is not preferable to apply a compound having a molecular weight of 1,500 or more in the structure because the effect of imparting flame retardancy is small and melting point of 90 ° C. or more is preferably applied.

It is preferable to use the aromatic phosphate ester compound applied as a flame retardant in this invention in the range of 5-30 weight part with respect to 100 weight part of base resins.

(D) bis (4-hydroxyphenyl) sulfone

Bis (4-hydroxyphenyl) sulfone is a compound having a structure completed by combining two phenols and a sulfone group, and has a strong electron-absorbing property of sulfone and a resonance structure with a large phenol sulfone bond, which is good for heat of oxidation and light stability. It looks like a substance. Its main purpose is to be used as a raw material for improving dyeing fastness and flame retardant, but the present invention is applied as a flame retardant aid.

Bis (4-hydroxyphenyl) sulfone is a material that exhibits a melting phenomenon in the region of 220 to 270 ° C, and thus has a nonflammable performance. In the present invention, the component which imparts substantially flame retardancy has a high flame retardancy even when a small amount of flame retardant is applied because a nonflammable substance is evenly present in the base resin when the phosphate ester compound (C) or the bis (4-hydroxyphenyl) sulfone is added. You can get it.

The bis (4-hydroxyphenyl) sulfone has the formula

In the present invention, the bis (4-hydroxyphenyl) sulfone is used in the range of 3 to 20 parts by weight based on 100 parts by weight of the base resin.

(E) phenolic resin

In general, rubber-modified styrene-based resin hardly generates char when burned, so it is blended with a material capable of forming char. In the present invention, polyphenyl blended with rubber-modified styrene-based resin (a ₁ ) is used as a base resin. It is known that ene ether resin (a ₂ ) forms a char mainly in a high temperature range (350-500 degreeC). Therefore, by applying phenol resin which forms char in lower temperature range (300 ~ 450 ℃), char film is formed at the early stage of combustion to promote char generation of polyphenylene ether (a ₂ ) so that char is effectively formed on the combustion surface. .

However, since phenolic resins tend to be easily oxidized to easily form chromophores, the phenolic resin has a disadvantage in that it is difficult to apply to exterior materials of electrical and electronic products requiring weather resistance by rapidly lowering the weather resistance of the final resin when a large amount is used. Therefore, in the present invention, the bis (4-hydroxyphenyl) sulfone is applied as the main flame retardant auxiliary agent in order to prevent the weather resistance of the resin composition from deteriorating, and a phenol resin may be added as necessary.

Phenolic resins include resol type phenol resins and novolac type phenol resins, and both of them can be used in the present invention. In addition, the phenol resin may be classified into a thermosetting resin and a thermoplastic resin, all of which may be used. In the present invention, novolak-based phenol resins are more preferably used than resol-based phenol resins.

The phenol formaldehyde novolak resin, tertiary butyl phenol formaldehyde novolak resin, paraoctyl phenol formaldehyde novolak resin, paracyano phenol formaldehyde novolak resin, etc. may be used as the novolak phenol resin, Copolymers may also be used. The novolak-based phenol resin is preferably about 300 to 10,000 average molecular weight. The phenol resin is 0 to 20 parts by weight based on 100 parts by weight of the base resin.

The resin composition of the present invention may be added dropping inhibitors, impact modifiers, plasticizers, heat stabilizers, antioxidants, light stabilizers, compatibilizers, etc., if necessary, organic or inorganic pigments, dyes and talc, silica, mica, glass fiber Inorganic fillers such as may also be added. These are used in the amount of 0-30 weight part with respect to 100 weight part of base resin of this invention.

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) Basic resin consisting of rubber modified styrene resin and polyphenylene ether resin, (B) styrene-acrylonitrile copolymer, and (C) aromatic phosphate ester compound used in the resin compositions of Examples and Comparative Examples , (D) bis (4-hydroxyphenyl) sulfone, and (E) phenol resin production and specifications are as follows.

(A) Basic resin

(a ₁ ) Rubber modified styrene resin

It was prepared by mixing 40% by weight of styrene-containing graft copolymer resin (a ₁₁ ) and 60% by weight of styrene-containing copolymer resin (a ₁₂ ).

(a ₁₁ ) Styrene-containing graft copolymer resin (ABS)

36 parts by weight of styrene, 14 parts by weight of acrylonitrile and 150 parts by weight of deionized water are added to 50 parts by weight of butadiene rubber latex, 1.0 part by weight of potassium oleate, 0.4 part by weight of cumene hydroperoxide, 0.2 parts by weight of mercaptan-based chain transfer agent, 0.4 parts by weight of glucose, 0.01 parts by weight of iron sulfate hydrate, and 0.3 parts by weight of sodium pyrophosphate and maintained at 75 ° C. for 5 hours to complete the reaction to prepare graft ABS latex, and resin Styrene-containing graft copolymer resin (g-ABS) powder was prepared by adding and solidifying 0.4 parts by weight of sulfuric acid to the solid content of.

(a ₁₂ ) Styrene-containing copolymer resin (AN content 25% by weight)

To 75 parts by weight of styrene and 25 parts by weight of acrylonitrile, 120 parts by weight of deionized water, 0.15 parts by weight of azobisisobutyronitrile, 0.4 parts by weight of tricalcium phosphate, and 0.2 parts by weight of mercaptan-based chain transfer agent were added. The copolymer resin (SAN) having an acrylonitrile content of 25% by weight was prepared by heating to 80 ° C. and then maintaining the temperature at 80 ° C. for 180 minutes. It was washed with water, dehydrated and dried to prepare a SAN powder. The weight average molecular weight of the synthesized styrene-acrylonitrile copolymer resin was in the range of 160,000 to 200,000.

(a ₂ ) polyphenylene ether resin

Poly (2,6-dimethyl-1,4-phenylene) ether of Asahi Kasei Co., Ltd., Japan, was used, and the product name was P-401 as a powder in the form of particles having an average particle diameter of several μm.

(B) Styrene-acrylonitrile copolymer (AN 13 wt%)

120 parts by weight of deionized water, 87 parts by weight of styrene and 13 parts by weight of acrylonitrile, 0.1 part by weight of azobisisobutyronitrile, 1,1'-di (tertiarybutylperoxy) -3,3 ', 5-trimethyl 0.2 part by weight of cyclohexane, 0.4 part by weight of tricalcium phosphate, and 0.2 part by weight of mercaptan-based chain transfer agent were added. The temperature was raised from 80 ° C. to 90 ° C. for 90 minutes, maintained at this temperature for 150 minutes, and then elevated to 95 ° C., followed by 120 minutes. Was maintained to prepare a copolymer resin (SAN) having an acrylonitrile content of 13% by weight. It was washed with water, dehydrated and dried to prepare a SAN powder. The weight average molecular weight of the synthesized styrene-acrylonitrile copolymer resin was in the range of 100,000 to 140,000.

(C) Aromatic Phosphate Ester Compounds

(c ₁ ) tri (2,6-dimethylphenyl) phosphate

A commercially available product having a melting point of 137 ° C was purchased and used.

(c ₂ ) triphenyl phosphate

A commercially available product having a melting point of 48 ° C. was purchased and used.

(D) bis (4-hydroxyphenyl) sulfone

Diphon A, Yorkshire, England, having a molecular weight of 250 and a melting point of 240 ° C., was used.

(E) phenolic resin

Phenol Novolac structure of PSM 4324 Grade in Gunei, Japan was used.

The resin compositions of Examples 1 to 2 and Comparative Examples 1 to 3 were prepared in the compositions shown in Table 1 below.

Item Example Comparative Example One 2 One 2 3 A Rubber modified styrene resin (a ₁ ) 75 75 75 75 75 Poly (2,6-dimethyl-1,4-phenylene) ether (a ₂ ) 25 25 25 25 25 B SAN (AN: 13 wt%) 6 6 6 6 - C Tri (2,6-dimethylphenyl) phosphate (c ₁ ) 16 16 16 - 16 Triphenylphosphate (c ₂ ) - - - 16 - D Bis (4-hydroxyphenyl) sulfone 6 3 - - - E Phenolic Resin - 3 6 6 6

The resin compositions of Examples 1 to 2 and Comparative Examples 1 to 3 were added in the amounts shown in Table 1, and extruded at a temperature range of 200 to 280 ° C. in a conventional twin screw extruder to prepare pellets. The prepared pellets were dried for 3 hours at a temperature of 80 ° C., and then injected in a 10 Oz injection machine under conditions of a molding temperature of 220 to 280 ° C. and a mold temperature of 40 to 80 ° C. to prepare a physical specimen. The manufactured specimens were measured for Izod impact strength (1/8 "notch) in accordance with ASTM D-256, and for measuring biquet softening temperature at 5 kg load in accordance with ASTM D-1525, and flame retardancy (1/10) in accordance with UL94 flame retardant regulations. ") And the flowability at 200 ℃ and 5kg load according to ASTM D-1238, and the weather resistance as the degree of discoloration (ΔE) when exposed to ultraviolet rays (UV) for 6 hours under the atmosphere of 60 ℃. It is listed in Table 2 below.

Item Example Comparative Example One 2 One 2 3 Izod impact strength (1/8 ", kgfcm / cm) 19 18 18 16 2 Vicket Softening Temperature (VST) (℃) 87 87 87 78 90 Flame Retardant (1/10 ") V-1 V-1 V-1 V-1 V-1 Weatherability (ΔE) 5.5 7.4 9.9 10.0 10.4

In Examples 1 and 2 manufactured according to the present invention, it was found that the impact strength, heat resistance, flame retardancy and weather resistance were all good. In Comparative Example 1 in which only phenol resin was applied as a flame retardant aid and bis (4-hydroxyphenyl) sulfone was excluded, flame retardancy was good, but weather resistance was lowered. On the other hand, Example 1, in which only bis (4-hydroxyphenyl) sulfone was applied, was found to have the best weather resistance. In addition, in the case of Example 2 in which bis (4-hydroxyphenyl) sulfone and phenol resin are used in combination, it also showed excellent weather resistance compared to the comparative example. As a result, compared to Comparative Examples 1 to 3 in which only the same amount of phenyl resin was applied without using bis (4-hydroxyphenyl) sulfone, not only did they have the same level of flame retardancy but also excellent weather resistance.

In Comparative Example 2 in which the aromatic phosphate ester compound having a melting point of less than 90 ° C. was applied, the impact strength and the heat resistance were lower than those in Examples 1 and 2. The resin compositions of Examples 1 and 2 were commercially available by applying a styrene-acrylonitrile copolymer resin having an acrylonitrile content of 13% by weight to a blend of a rubber-modified styrene-based resin and a polyphenylene ether resin having no compatibility with each other. As a result of improving the properties, it can be seen that the impact strength is remarkably superior to Comparative Example 3, in which no styrene-acrylonitrile copolymer resin is added.

In the present invention, (A) rubber-modified styrene resin, polyphenylene ether resin, (B) styrene-acrylonitrile copolymer having a content of 5-18% by weight of acrylonitrile, (C) aromatic phosphate ester compound, and (D) It is essential to include bis (4-hydroxyphenyl) sulfone, and it is preferable to use a compound having a melting point of 90 ° C. or higher as the phosphate ester compound. It can be seen that a resin composition having improved weather resistance as well as improved physical properties such as flame retardancy can be obtained.

The thermoplastic resin composition of the present invention is added to the blend of the rubber-modified styrene resin and the polyphenylene ether resin to improve the compatibility by adding a styrene-acrylonitrile copolymer resin having an acrylonitrile content of 5 to 18% by weight. It is excellent in strength and has a melting point of more than 90 ℃ aromatic phosphate ester compound by applying a flame retardant and bis (4-hydroxyphenyl) sulfone and phenolic resin as a flame retardant aid has a good flame retardancy and excellent weather resistance has the effect of the invention. Even if no halogen compound is added to the rubber-modified styrenic copolymer resin, not only flame retardancy and weather resistance but also mechanical properties and the like have very good effects of the invention. In addition, the present invention does not cause any environmental pollution problems by containing no existing halogen flame retardant that generates toxic gases during processing or combustion of the resin.

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) (a ₁ ) 100 parts by weight of a base resin composed of 40 to 95% by weight of rubber-modified styrene resin and (a ₂ ) 60 to 5% by weight of polyphenylethylene resin; (B) 2 to 20 parts by weight of a styrene-acrylonitrile copolymer having an acrylonitrile content of 5 to 18% by weight; (C) 5-30 weight part of aromatic phosphate ester compounds whose melting | fusing point is 90 degreeC or more; (D) 3 to 20 parts by weight of bis (4-hydroxyphenyl) sulfone; And (E) 0-20 weight part of phenol resins; A flame retardant thermoplastic resin composition having improved weather resistance. The weathering resistance according to claim 1, wherein the rubber-modified styrene resin (a ₁ ) comprises 20 to 100 wt% of a styrene-containing graft copolymer resin and 80 to 0 wt% of a styrene-containing copolymer resin. Improved flame retardant thermoplastic resin composition. The flame retardant thermoplastic resin composition of claim 1, wherein the aromatic phosphate ester compound (C) is represented by the following Chemical Formula 1 or 2: Formula 1 Wherein R ₁ , R ₂ and R ₃ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, and X is derived from a dialcohol such as resorcinol, diphenol, hydroquinol, bisphenol-A, bisphenol-S, etc. N is a value from 0 to 4; Formula 2 Wherein R ₄ , R ₅ and R ₆ are hydrogen or an alkyl group having 1 to 4 carbon atoms. The flame retardant thermoplastic resin composition of claim 1, wherein the bis (4-hydroxyphenyl) sulfone (D) is melted at 220 to 270 ° C and is represented by the following Chemical Formula 3. Formula 3 The flame retardant thermoplastic resin composition of claim 1, wherein the phenol resin (E) is a novolak-based resin. The flame retardant thermoplastic resin according to any one of claims 1 to 5, further comprising a plasticizer, a heat stabilizer, an antioxidant, a light stabilizer, a compatibilizer, a pigment, a dye, and / or an inorganic additive. Composition.