KR100458071B1 - Flameproof Styrenic Resin Composition - Google Patents

Abstract

Flame-retardant styrene resin composition of the present invention (A) 40 to 85% by weight of rubber-reinforced polystyrene resin; (B) 10 to 40% by weight of polyphenylene ether resin; And 5 to 20% by weight of an organophosphorous compound comprising (C) 30 to 80% by weight of the (C ₁ ) oxa phosphoran compound and 20 to 70% by weight of the (C ₂ ) aromatic phosphate ester compound.

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 is applied to the blend of rubber-reinforced polystyrene resin copolymer and polyphenylene ether resin by applying a mixture of an oxa phospholane compound and an aromatic phosphate ester compound as a flame retardant to improve the flame retardancy, heat resistance and mechanical strength The present invention relates to a styrene-based thermoplastic resin composition which is excellent in environmental friendliness since it does not use a halogen-based flame retardant that is excellent 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 used flame retardant method is to impart flame retardant properties by applying a halogen compound and an antimony compound to a 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.

U.S. Patent No. 3,639,506 discloses compositions using aromatic phosphate esters and aromatic halogen flame retardants in polyphenylene ethers and styrene resins.

In addition, U.S. Patent No. 4,526,917 uses a monophosphate ester compound having triphenyl phosphate (TPP) and mesityl groups in polyphenylene ether and styrene resin to improve flame retardancy. However, in order to obtain sufficient flame retardancy, the amount of polyphenylene ether must be increased, which results in a poor flowability.

U. S. Patent No. 5,334, 760 uses the ring-opened oxa-phosphoran compound as a reactive flame retardant of polyester.

On the other hand, the present inventors have excellent flame retardancy by using a mixture of an oxa phospholane-based compound and an aromatic phosphate ester-based compound as a flame retardant in the base resin consisting of rubber-reinforced polystyrene resin and polyphenylene ether resin in order to overcome the above problems In addition, the present inventors have developed a resin composition excellent in flowability, heat resistance and flexural strength.

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

Another object of the present invention is to provide an environmentally friendly styrene resin composition by using an environmentally friendly compound as a flame retardant instead of 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.

Flame retardant styrene resin composition of the present invention (A) 40-85% by weight of rubber-reinforced polystyrene resin; (B) 10-40% by weight of polyphenylene ether resin; And 5-20% by weight of an organophosphorous compound comprising (C) 30-80% by weight of the (C ₁ ) oxa phosphorane compound and 20-70% by weight of the (C ₂ ) aromatic phosphate ester compound.

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

(A) Rubber reinforced styrene resin

The rubber-reinforced styrene resins used in the present invention are prepared by mixing rubber with aromatic monoalkenyl monomers and / or alkyl ester monomers and polymerizing them by thermal polymerization or by using a polymerization initiator thereto.

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, 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) Organophosphorus Compound

The organophosphorus compound used as the flame retardant in the present invention is used by mixing 30-80% by weight of the (C ₁ ) oxa phosphorane compound and 20-70% by weight of the (C ₂ ) aromatic phosphate ester compound. Each detailed description of these is as follows.

(C ₁ ) oxa phosphoran compound

An oxa phosphoran compound of the present invention is represented by the following formula (1).

[Formula 1]

Wherein R ₁ is hydrogen; An alkyl group of C ₁ -C ₄ ; Or an aryl group of C ₆ -C ₁₀ , and R ₂ , R ₃ are hydrogen or an alkyl group of C ₁ -C ₄ . N has a value of 1 to 3.

Representative examples of the oxa phospholane-based compound include 2-methyl-2,5-dioxo-1-oxa-2-phosphoran and 2-petyl-2,5-dioxo-1-oxa-2-phosphoran Can be mentioned.

The oxa phosphoran compound may be used alone or as a mixture of two or more.

(C ₂ ) Aromatic Phosphate Ester Compounds

The aromatic phosphate ester compound of the present invention is represented by the following formula (2).

[Formula 2]

R ₄ , R ₅ and R ₆ are each independently hydrogen or an alkyl group of C _1-4 ; X is a C _6-20 aryl group substituted with a C _6-20 aryl group or an alkyl group and is derived from dialcohols such as resorcinol, hydroquinol, bisphenol-A, bisphenol-S and the like; m has a value of 0-4.

Examples of the compound represented by Chemical Formula 2 include triphenyl phosphate, tricresyl phosphate, trigylenyl phosphate, tri (2,6-dimethylphenyl) phosphate, and tri (2,4,6-trimethylphenyl) when n is 0. Phosphate, tri (2,4-dibutylbutylphenyl) phosphate, tri (2,6-dibutylbutylphenyl) phosphate, and the like, when n is 1, resorcinol bis (diphenyl) phosphate, resorcinol Bis (2,6-dimethylphenyl) phosphate, resorcinolbis (2,4-dibutylbutyl) phosphate, hydroquinolbis (2,6-dimethylphenyl) phosphate, hydroquinolbis (2,4-diary) Butylphenyl) phosphate etc. are typical examples.

The phosphate ester compound may be applied alone or may be applied to each mixture.

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

Preparation and specifications of (A) rubber-reinforced styrene resin, (B) polyphenylene ether resin and (C) organophosphorus compound used in Examples and Comparative Examples illustrated in Table 1 below are as follows.

(A) Rubber reinforced styrene resin

As rubber-reinforced polystyrene resin, Cheil Industries Co., Ltd. HF-1690H was used.

(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) Organophosphorus Compound

(C ₁ ) 2-methyl-2,5-dioxo-1-oxa-2-phosphoran having a melting point of 242 ° C-245 ° C was used.

(C ₂₁ ) Triphenyl phosphate (TPP) with a melting point of 48 degrees was used.

₍₂₂ C) was used as resorcinol di (2,6-dimethylphenyl) Japanese daepal chemical phosphate (trade name: PX-200).

Example 1-3

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 1-3

Comparative Example 1 was prepared in the same manner as in Example 1 except that only 2-methyl-2,5-dioxo-1-oxa-2-phosphoran was used alone as a flame retardant.

Comparative Example 2 was prepared in the same manner as in Example 1 except that only triphenyl phosphate (TPP) was used alone as a flame retardant.

Comparative Example 3 was prepared in the same manner as in Example 1, except that only resorcinol di (2,6-dimethylphenyl) phosphate was used as a flame retardant.

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

(1) The heat resistance was measured at 200 ° C. and 5 kgf load according to ASTM D1525 standard.

(2) The melt flow index was measured at 200 ° C. in accordance with ASTM D1238.

(3) Flexural strength was measured under ASTM D 790 conditions.

(4) Flame retardancy was measured at a thickness of 1/12 "by UL 94 VB.

Compositions and physical properties of the resins prepared in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below.

Item Example Comparative Example One 2 3 One 2 3 (A) Rubber reinforced styrene resin 80 80 80 80 80 100 (B) PPE 20 20 20 20 20 10 (C) Organic Phosphorus Compound (C ₁ ) 3 3 5 10 - - (C ₂₁ ) 7 - 5 - 10 - (C ₂₂ ) - 7 - - - 10 Vicat Softening Temperature (℃) 84 90 86 90 76 94 Melt Flow Index (g / ml) 5.8 4.5 5.3 3.5 6.2 2.3 Flexural Strength (kgf / cm ² ) 500 520 505 480 460 495 UL94 flame retardant (1/12 ") V-0 V-0 V-0 V-0 V-2 Fail

From the results in Table 1 above, when using an oxa phospholane compound and an aromatic phosphate ester compound as a flame retardant, achieved a flame retardancy of V-0 at 1/12 "thickness, thermal properties, mechanical properties and flow properties On the other hand, Comparative Example 1, in which only the oxa phosphoran-based compound was applied as a flame retardant, had excellent heat resistance, but showed low flowability and flexural strength, using triphenyl phosphate (TPP) as a flame retardant. In Comparative Example 2, the flowability was excellent, but the heat resistance and mechanical strength were greatly reduced, and Comparative Example 3 using only resorcinol di (2,6-dimethylphenyl) phosphate as a flame retardant was remarkably flowable and flame retardant. It was found to be degraded.

According to the present invention, by using an oxa phospholane compound and an aromatic phosphate ester compound as a flame retardant in a base resin composed of a rubber-reinforced polystyrene resin and a polyphenylene ether resin, heat resistance, flow chart, and flexural strength are achieved while having environmental stability and fire safety. It has the effect of providing the excellent flame retardant styrene resin composition.

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) 40 to 85% by weight of rubber-reinforced polystyrene resin; (B) 10 to 40% by weight of polyphenylene ether resin; And (C) 5 to 20% by weight of an organophosphorous compound consisting of 30 to 80% by weight of the (C ₁ ) oxa phosphoran compound and 20 to 70% by weight of the (C ₂ ) aromatic phosphate ester compound; Flame-retardant styrene resin composition, characterized in that consisting of. The flame retardant styrene-based resin composition according to claim 1, wherein the oxa phosphoran compound (C ₁ ) is represented by the following general formula ( ₁ ). [Formula 1] Wherein R ₁ is hydrogen; C ₁ -C ₄ alkyl group; or C ₆ -C ₁₀ aryl group, R ₂ , R ₃ are hydrogen or C ₁ -C ₄ alkyl group. N is 1 to 3 Has the value of) The flame-retardant styrene resin composition of claim 1, wherein the aromatic phosphate ester compound (C ₂ ) is represented by the following Chemical Formula 2. [Formula 2] (Wherein R ₄ , R ₅ and R ₆ are each independently hydrogen or an alkyl group of C _1-4 ; X is a C _6-20 aryl group or a C _6-20 aryl group substituted with an alkyl group resorcinol Derived from dialcohols such as hydroquinol, bisphenol-A and bisphenol-S; m has a value from 0 to 4) The flame retardant styrene-based resin composition of 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. .