KR100458069B1 - Flameproof Styrenic Resin Composition - Google Patents

Abstract

The flame retardant styrene resin composition of the present invention comprises (A) 60 to 99.4 weight% of rubber-reinforced styrene resin; (B) 0.5 to 20% by weight of polyphenylene ether resin; And (C) (C ₁₎ Hin hindered oligomer type phosphoric acid ester compound having a methyl group 25 to 80% by weight, and (C ₂₎ a naphthyl phosphate ester compound having 20 to 75 5 to 20% by weight butyl phosphate ester compound comprising in weight percent Characterized in that consists of.

Description

Flame retardant styrene resin composition {Flameproof Styrenic Resin Composition}

Field of invention

The present invention relates to a styrene resin composition having excellent environmental friendliness and excellent flame retardancy. More specifically, the present invention uses a phosphate ester compound composed of a phosphate ester compound having a hindered methyl group and a phosphate ester compound having a naphthyl group in a blend composed of a rubber-reinforced styrene resin copolymer and a polyphenylene ether resin. The present invention relates to a styrene-based thermoplastic resin composition having excellent environmental friendliness since it does not use a halogen-based flame retardant having excellent flame retardancy, heat resistance and mechanical strength, and which has been tightened in terms of environmental stability.

Background of the Invention

Styrene-based resins, which are used as exterior materials for electronic products, are applied to almost all electronic products due to their excellent processability and mechanical properties. However, since the styrene resin itself has a property that combustion can easily occur, there is no fire resistance. Therefore, the styrene resin may be easily burned by an external ignition source, and may serve to further spread the fire. In view of this, the United States, Japan and Europe, etc., regulate the law to use only polymer resin that meets the flame retardant specification as an exterior material in order to ensure the safety of fire of electronic products.

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-reinforced styrene resin. As the halogen-based compound, polybromodiphenyl ether, tetrabromobisphenol-A, brominated substituted epoxy compound, chlorinated polyethylene and the like are mainly used. As the antimony compound, antimony trioxide and antimony pentoxide are mainly used.

However, the method of imparting flame retardancy by applying a halogen and an antimony compound together has an advantage of easily obtaining flame retardancy and hardly deteriorating physical properties. However, hydrogen halide gas generated during processing is likely to have a fatal effect on the human body. In particular, since polybrominated diphenyl ethers, which are mainly halogen-based flame retardants, are highly likely to generate very toxic gases such as dioxins and furans during combustion, recent interest in flame retardant methods that do not apply such halogen-based compounds has attracted much attention. ought.

As a halogen-free flame retardant, a method of adding flame retardance to a resin composition by adding a monophosphate ester compound such as triphenyl phosphate has been studied.

In US Pat. No. 4,526,917, flame retardancy was improved by using a monophenyl phosphate ester compound having triphenyl phosphate (TPP) and mesityl groups in polyphenylene ether and styrene resin. However, the amount of the polyphenylene ether used in the US patent is 20% by weight or more, and in such a composition, it is very difficult to achieve drop type flame retardancy while maintaining flowability.

In contrast, the present inventors use a rubber-reinforced styrene resin and a polyphenylene ether as a base resin, and apply a phosphate ester compound having a hindered methyl group and a phosphate ester compound having a naphthyl group as a flame retardant. Thus, a resin composition excellent in environmental stability, flame retardancy, and heat resistance was developed. In addition, the use of less than 20% polyphenylene ether has led to the development of a resin excellent in flowability and dropping flame retardancy.

An object of the present invention is to provide a thermoplastic flame retardant styrene resin composition that is stable against fire.

Another object of the present invention is to provide a styrene resin composition having environmental stability by using an environmentally friendly compound as a flame retardant, rather than using a halogen compound that causes environmental pollution during processing or combustion of the resin as a flame retardant.

Still another object of the present invention is to provide a flame retardant styrene resin composition which can be used as an exterior material such as electronic products with excellent heat resistance and flow chart.

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 flame retardant styrene resin composition of the present invention comprises (A) 60 to 99.4 weight% of rubber-reinforced styrene resin; (B) 0.5 to 20% by weight of polyphenylene ether resin; And (C) (C ₁₎ comprises a hinge hindered phosphoric acid ester compound having a methyl group, and 25-80% by weight of (C ₂₎ 5~20% by weight of phosphoric acid ester compounds consisting of 20-75% by weight of phosphoric acid ester compound having a naphthyl .

Hereinafter, the detailed description of each of these components is as follows.

(A) Rubber reinforced styrene resin

The rubber-reinforced styrenic resin used in the present invention is prepared by mixing a rubber with an aromatic monoalkenyl monomer and / or an alkyl ester monomer and polymerizing using a thermal polymerization or polymerization initiator.

The rubber is selected from the group consisting of butadiene rubbers, isoprene rubbers, copolymers of butadiene and styrene, alkyl acrylate rubbers, and the like, and preferably 3 to 30 parts by weight, preferably 5 to 15 parts by weight.

In addition, the monomer is selected from the group consisting of aromatic monoalkenyl monomers, alkyl ester monomers of acrylic acid or methacrylic acid, and 70 to 97 parts by weight, preferably 85 to 95 parts by weight of one or more monomers selected from the group. It is desirable to.

The present invention may be prepared by polymerization using a polymerization initiator, and may be prepared by thermal polymerization without the polymerization initiator.

Polymerization initiators that may be used in the present invention include one of peroxide initiators consisting of benzoyl peroxide, t-butyl hydroperoxide, acetyl peroxide, cumenehydro peroxide and azo initiators such as azobis isobutyronitrile (AIBN). More than one species can be selected and used.

The rubber-reinforced styrenic resin may be prepared using a bulk polymerization, suspension polymerization, emulsion polymerization or a mixture thereof, and among these polymerization methods, a bulk polymerization method may be preferably used.

In order to give optimum physical properties in the blend of the rubber-reinforced styrene resin and the polyphenylene ether resin, the rubber particle size is preferably 0.5 to 2.0 µm.

(B) polyphenylene ether resin

Since rubber-reinforced styrene resins are insufficient in flame retardancy and deteriorated in heat resistance, in the present invention, polyphenylene ether resin is added and used as the base resin. Examples of the polyphenylene ether resin include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-di Propyl-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-diphenyl-1,4-phenylene) ether, poly (2,6-dimethyl-1,4-phenylene ) Copolymer of poly (2,3,6-trimethyl-1,4-phenylene) ether and poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3,5- Copolymers of triethyl-1,4-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 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.

(C) phosphate ester compound

The phosphate ester compound used as the flame retardant in the present invention is used by mixing 25-80% by weight of the phosphate ester compound having a (C ₁ ) hindered methyl group and 20-75% by weight of the phosphate ester compound having a (C ₂ ) naphthyl group. . Detailed description of each of the phosphate ester compounds of the present invention is as follows.

(C ₁ ) phosphate ester compound having a hindered methyl group

Phosphoric acid ester compound having a hindered methyl group of the present invention is represented by the following formula (1).

[Formula 1]

In the above formula, n represents a number average degree of polymerization, and the value of n is a value between 0 and 4. X is derived from dialcohol, and may be one derived from catechol, resorcinol, hydroquinone, and bisphenylenediol represented by the following Formula 2.

[Formula 2]

Wherein Y represents C _1-5 alkylene, C _1-5 alkylidene, C _5-6 cycloalkylidene, S or SO ₂ , z is 0 or 1. Of these, resorcinol and bisphenol A are preferable.

Representative compounds of Formula 1 include tri (2,6-dimethylphenyl) phosphate, resorcinol di (2,6-dimethylphenyl) phosphate and bisphenol A di (2,6-dimethylphenyl) phosphate, and these phosphorus-based compounds The compounds may be applied alone or in mixtures of each.

(C ₂ ) Phosphate Ester Compounds Having Naphthyl Group

The phosphate ester compound having a naphthyl group of the present invention is represented by the following formula (3).

[Formula 3]

In Formula 3, m is an integer between 0 and 2. Representative compounds of Formula 3 include naphthyldiphenyl phosphate, dinaphthylphenyl phosphate, and trinaphthyl phosphate, and these compounds may be used alone or in mixtures thereof.

In the thermoplastic resin manufacturing method of the present invention, an antidripping agent, an impact enhancer, a plasticizer, an inorganic additive, a heat stabilizer, an antioxidant, a compatibilizer, a light stabilizer, a pigment, and / or a dye may be added according to each use. The inorganic additives to be added include asbestos, glass fibers, talc, ceramics and sulfates, which may be used in an amount of 0 to 30 parts by weight based on 100 parts by weight of the base resin of the present 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

The specifications of (A) rubber-reinforced styrene resin, (B) polyphenylene ether resin, and (C) phosphate ester compound used in the following examples and comparative examples are as follows.

(A) Rubber reinforced styrene resin

Rubber-reinforced styrene resin was HR-1380 manufactured by Cheil Industries.

(B) polyphenylene ether (PPE) resin

Poly (2,6-dimethyl-phenylether) (trade name P-402) of Asahi Kasei Co., Ltd., Japan, was used, and the particle size was in the form of a powder having an average particle diameter of several tens of micrometers.

(C) phosphate ester compound

(C ₁ ) As a phosphate ester compound having a hindered methyl group, resorcinol di (2,6-dimethylphenyl) phosphate (trade name PX-200) manufactured by Nippon Scorpion Co., Ltd. was used.

(C ₂₎ a phosphoric acid ester compound having a naphthyl, was used for the tildi naphthyl diphenyl phosphate having a melting point of 62 ℃.

(C ₂ ) Triphenyl phosphate (TPP) with a melting point of 48 ° C. was used.

Example 1-2

Each component was added to the content shown in Table 1 below and extruded in a conventional twin screw extruder at a temperature range of 200 ~ 280 ℃ to prepare a pellet. The prepared pellet was dried at 80 ° C. for 3 hours, and then injected into a 6 Oz injection machine under conditions of a molding temperature of 180 to 280 and a mold temperature of 40 to 80 ° C. to prepare a physical specimen.

Comparative Example 1-4

Comparative Example 1-2 was prepared in the same manner as in Example 1, except that only resorcinol di (2,6-dimethylphenyl) phosphate or naphthyldimethyl phosphate was used alone as a flame retardant.

Comparative Example 3 was prepared in the same manner as in Example 1, except that triphenylphosphate (TPP) was used instead of the naphthyldimethyl phosphate of the present invention.

Comparative Example 4 was prepared in the same manner as in Example 1 except that only triphenylphosphate (TPP) was used as a flame retardant.

Physical properties of the specimens prepared in Examples and Comparative Examples were measured by the following methods.

(1) Vicat softening temperature (VST) was measured at 200 ° C and 5 kgf load according to ASTM D1525 standard.

(2) Melt flow index was measured according to ASTM D1238.

(3) Izod impact strength was measured under ASTM 256A conditions at 1/8 "thickness.

(4) Tensile strength was evaluated according to ASTM D 638 conditions.

(5) Flame retardancy was measured by using a specimen of thickness 1/8 "and 1/12" by UL 94 VB.

The composition and physical properties of the resin prepared in Example 1-2 and Comparative Example 1-4 are shown in Table 1 below.

Item Example Comparative Example One 2 One 2 3 4 Ingredients (parts by weight) (A) Rubber modified styrene resin 100 100 100 100 100 100 (B) PPE resin 10 10 10 10 10 10 (C) phosphate ester compound (C ₁ ) 2 4 - 8 2 - (C ₂ ) 6 4 8 - - - (C ₃ ) - - - - 6 8 Properties Vicat Softening Temperature (℃) 91 93 92 96 85 78 Melt Flow Index (g / ml) 9.0 8.8 8.2 4.7 10.2 12.4 Izod impact strength (1/8 ") 13 12 10 9 11 6 Tensile Strength (kgf / cm ² ) 415 430 360 365 370 350 UL94 Flame Retardant (1/8 ") V-2 V-2 Fail Fail V-2 Fail UL94 flame retardant (1/12 ") V-2 V-2 Fail V-2 V-2 Fail

From the results in Table 1, when using a phosphate ester compound having a hindered methyl group and a phosphate ester having a naphthyl group as a flame retardant, flame retardancy of V-2 was achieved at 1/8 "and 1/12" thickness, respectively. It was found to be excellent in thermal properties, mechanical properties and flow properties. On the other hand, in Comparative Example 1 using only a phosphate ester having a naphthyl group as the flame retardant, the tensile strength and impact strength was lowered, it was not possible to achieve the flame retardancy of V-2. In addition, in Comparative Example 2 using only a phosphate ester compound having a hindered methyl group as a flame retardant, flame retardancy of V-2 was achieved at 1/12 "thickness, respectively, but it was found that the flowability and mechanical properties were significantly reduced. The use of triphenyl phosphate in place of the phosphate ester having a naphthyl group as the flame retardant decreased the heat resistance and the tensile strength of Comparative Example 3. The heat resistance and mechanical properties of Comparative Example 4 in which only triphenyl phosphate was used as the flame retardant alone were also applied. This was found to be significantly lowered.

The present invention is applied to the base resin consisting of a rubber-reinforced styrene resin and a polyphenylene ether resin by applying a phosphate ester compound consisting of a phosphate ester compound having a hindered methyl group and a phosphate ester compound having a naphthyl group, thereby improving environmental stability and fire safety It has an effect of providing a flame retardant rubber-reinforced styrene resin composition having excellent heat resistance, impact strength and flowability.

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 (4)

(A) 60 to 99.5 weight% of rubber-reinforced styrene resin; (B) 0.5 to 20% by weight of polyphenylene ether resin; And (C) (C ₁₎ a hindered oligomer type phosphoric acid ester compound having a methyl group, and 25-80% by weight of (C ₂₎ a naphthyl phosphate ester compound having 20 to 75 butyl phosphate ester compound composed of 5 to 20% by weight% by weight; Flame-retardant styrene resin composition, characterized in that consisting of. The flame-retardant styrene resin composition according to claim 1, wherein the oligomer-type phosphate ester compound (C ₁ ) having a hindered methyl group is represented by the following general formula ( ₁ ). [Formula 1] Where n is the number average degree of polymerization and is a value between 0 and 4. X is derived from dialcohol, catechol, resorcinol, hydroquinone and bisphenylenediol represented by the following formula (2). [Formula 2] Wherein Y represents C _1-5 alkylene, C _1-5 alkylidene, C _5-6 cycloalkylidene, S or SO ₂ , z is 0 or 1. The flame retardant styrene resin composition according to claim 1, wherein the phosphate ester compound (C ₂ ) having a naphthyl group is represented by the following general formula (3). [Formula 3] In which m is an integer between 0 and 2. The flame retardant styrene-based resin according to claim 1, wherein the resin composition further comprises an antidropping agent, an impact enhancer, a plasticizer, an inorganic additive, a heat stabilizer, an antioxidant, a compatibilizer, a light stabilizer, a pigment, and / or a dye. Composition.