KR100467809B1 - Non-halogen fire retardant styrene resin composition - Google Patents

Abstract

The present invention relates to a dropping non-halogen flame retardant styrene resin composition, and the dropping non-halogen flame retardant styrene resin composition of the present invention is excellent in dropping flame retardancy and does not cause harmful substances to humans even upon disposal.

Description

Dropping type non-halogen flame-retardant styrene resin composition {NON-HALOGEN FIRE RETARDANT STYRENE RESIN COMPOSITION}

[Industrial use]

The present invention relates to a flame retardant styrene resin composition, and more particularly to a non-halogen flame retardant styrene resin composition excellent in dropping flame retardancy.

[Prior art]

Styrene-based resins represented by impact-resistant polystyrene are used in various industrial fields, including home appliances, automobile parts, and office equipment parts because of their excellent moldability, rigidity, and electrical properties. In particular, recently, it is mainly used for a television housing.

Although the styrene resin has excellent processability and physical properties, it has a problem in terms of safety because it has a property of easily burning. Accordingly, studies have been made to secure safety by providing flame retardancy to styrene resins. The regulation on flame retardancy follows the UL (Underwriters Laboratories) standard, and has mainly adopted a method in which halogen-based flame retardants are blended with styrene-based resins together with flame retardant aids to produce styrene resins having flame retardancy suitable to UL standards. As the halogen flame retardant, polybromodiphenyl ether, tetrabromobisphenol A, an epoxy compound substituted with bromine, chlorinated polyethylene and the like are mainly used. As the flame retardant aid, an antimony-based compound is used, and mainly antimony trioxide and antimony pentoxide are used.

As described above, the method of imparting flame retardancy to the styrene resin by applying a halogen flame retardant and an antimony flame retardant aid together can produce a styrene resin that is excellent in flame retardancy and hardly causes a decrease in physical properties of the final product. There is an advantage. However, there is a problem that hydrogen halide gas may be generated during processing to damage the mold, and dioxin having strong carcinogenicity is discharged from the waste incinerator at the time of disposal due to the presence of halogen compounds, which adversely affects the environment and the human body. Moreover, in recent years, as the movement to regulate halogen-based flame retardant resin materials is actively made, it is necessary to develop materials for flame-retardant styrene resins containing no halogen element.

In order to ensure the flame retardance of the polystyrene resin containing no halogen element, a method of mainly applying an aromatic phosphorus ester compound may be used. In the case of applying such a phosphorus ester compound alone, there is a problem that the heat resistance of the polystyrene resin is lowered and it is difficult to achieve the flame retardancy to be achieved. Therefore, in order to improve heat resistance of polystyrene resin and to impart flame retardancy, polyphenylene ether is blended with rubber-reinforced polystyrene Methods of applying phosphate ester compounds have been presented and studied.

The polyphenylene ether has the advantages of excellent mechanical properties, electrical properties, heat resistance, low temperature properties and dimensional stability, low water absorption, and easily flame retardant. However, since it has a drawback that the molding processability and impact resistance are insufficient, it is blended with rubber-reinforced polystyrene to improve the above defects to resin compositions such as electric and electronic parts, office equipment housings, automobile parts, precision parts, and various industrial parts. I use it widely. Thus, the resin obtained by blending with polyphenylene ether and rubber-reinforced polystyrene resin is low molecular weight triphenylphosphate, cresyl diphenyl phosphate, tricresyl phosphate, high molecular weight resorcinol bis diphenyl phosphate, tridiphenyl Phosphoric acid ester compounds such as phosphate have been applied to achieve flame retardancy.

In the processing of the polyphenylene ether and rubber-reinforced polystyrene blend flame retardant resin, since the polyphenylene ether has a high heat resistance, the screw is designed to be processed separately to increase the processing temperature or to greatly increase the shear force. At this time, when the processing temperature is more than 250 ℃ low molecular weight phosphate ester compound may be affected by the change in physical properties and flame retardancy due to the change in the content of the phosphate ester compound present in the final resin compared to the initial dose. In addition, in the preparation of the dropping flame retardant resin, the higher the content of the polyphenylene ether, the more the dropping flame retardancy desired can not be achieved by preventing the dropping of the flame retardant resin.

In view of the problems of the prior art, an object of the present invention is to provide a non-halogen flame retardant styrene resin composition capable of improving the drop-in flame retardancy of the blend resin of flame retardant polyphenylene ether and rubber-reinforced polystyrene.

It is also an object of the present invention to provide a dropping non-halogen flame retardant styrene resin composition that can minimize volatilization of the phosphate ester compound during processing.

The present invention, in order to achieve the above object, in the dropping non-halogen flame retardant styrene composition,

a) 85 to 99% by weight of rubber reinforced polystyrene resin; And

Ii) 15 to 1% by weight of polyphenylene ether resin

100 parts by weight of a base resin including;

b) 4 to 30 parts by weight of a phosphate ester compound; And

c) 0.1 to 10 parts by weight of calcium stearic acid

It provides a dropping non-halogen flame-retardant polystyrene-based resin composition comprising a.

Hereinafter, the present invention will be described in detail.

Dropping type non-halogen flame retardant styrene composition of the present invention,

The rubber-reinforced polystyrene resin of a) i) is a polymer in which a rubbery polymer is dispersed in the form of particles on a matrix composed of a vinyl aromatic polymer, and is a main component of a molding resin composition, which is prepared from the resin composition of the present invention. It serves to support the strength of the molded product. The rubber-reinforced polystyrene resin may be polymerized by bulk polymerization, suspension polymerization or emulsion polymerization, and it is particularly preferable to polymerize by bulk polymerization. When the rubber-reinforced polystyrene resin is prepared by bulk polymerization, the rubbery polymer is dissolved in a vinyl aromatic monomer and then stirred, followed by polymerization by adding a polymerization initiator.

The rubber-like polymer (soft component particles) of the rubber-reinforced polystyrene resin includes a diene rubber (high cis-butadiene) having a content of cis 1,4 bond of at least 70 wt% of the butadiene chain portion of the diene rubber. It is preferable that the content of the cis 1,4-bond in the butadiene chain in the rubbery polymer is 90% by weight or more. When the butadiene (low cis-butadiene) having a cis 1,4-linkage of the butadiene chain is less than 70% by weight, the effect of improving impact resistance of the polystyrene resin may be insignificant. It is preferable that the glass transition temperature (Tg) of the said rubbery polymer is -30 degrees C or less, and when the glass transition temperature of the said rubbery polymer exceeds -30 degreeC, the impact resistance of a polyester resin falls. The rubbery polymer is preferably a polybutadiene, styrene-butadiene copolymer, or butadiene-isoprene copolymer, and more preferably a polybutadiene, styrene-butadiene copolymer.

The content of the rubber-reinforced polystyrene is preferably contained 85 to 99% by weight in the base resin, the rubber-like polymer content in the rubber-reinforced polystyrene is 3 to 30% by weight, more preferably 4 to 15% by weight. The particle diameter of the rubber polymer particles dispersed in the form of particles in the rubber-reinforced polystyrene is preferably 0.5 to 6 ㎛.

Vinyl aromatic monomers used for the polymerization of rubber-reinforced polystyrene resins include nucleoalkyl substituted styrenes such as styrene, paramethyl styrene, 2,4-dimethyl styrene, and ethyl styrene; And alpha alkyl substituted styrene of alpha methyl styrene or alpha methyl paramethyl styrene. The content of the vinyl aromatic monomer is preferably 70 to 97% by weight in rubber-reinforced styrene.

The polyphenylene ether resin of a) ii) is a component for imparting heat resistance and flame retardancy to the rubber-reinforced polystyrene resin, a homopolymer of a compound represented by the following formula (1), or a copolymer comprising a compound of the formula (1) to be.

[Formula 1]

In Formula 1, R ₁ , R _2, R ₃ , and R ₄ are each independently or simultaneously chlorine, bromine, iodine, methyl, ethyl, propyl, allyl, phenyl, methylbenzyl, chloromethyl, bromomethyl, Cyanoethyl, cyano, methoxy, phenoxy, or nitro group. In particular, in the formula (1), R ₁ and R ₂ are alkyl groups, especially polymers having 1 to 4 carbon atoms, and preferably have a degree of polymerization of 50 or more.

Examples of the homopolymer of the polyphenylene ether resin include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, and poly (2 -Methyl-6-propyl-1,4-phenylene) ether, poly (2,6-zipurofil-1,4-phenylene) ether, poly (2-ethyl-6-propyl-1,4-phenyl Lene) ether, poly (2,6-dimethoxy-1,4-phenylene) ether, poly (2,6-dichloromethyl-1,4-phenylene) ether, poly (2,6-dibromomethyl -1,4-petylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, and poly (2,5-dimethyl-1,4-phenylene) ether can be used.

In addition, as the copolymer of the polyphenylethylene ether resin, a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol or o-cresol; Alternatively, polyphenylene ether copolymers mainly composed of polyphenylene ether structures such as copolymers of 2,3,6-trimethylphenol and o-cresol can be used. As the 2,6-dimethyl phenol used in the copolymer, poly (2,6-dimethyl, 1,4-phenylene) having an intrinsic viscosity (measured at 30 ° C. with a 0.5 g / dl chloroform solution) of 0.25 to 0.50 Preference is given to using ethers.

The polyethylene ether resin is a homopolymer or copolymer of the polyethylene ether in addition to the polyethylene ether homopolymer and the copolymer, α, β-unsaturated carboxylic acid or a derivative thereof, styrene or a derivative thereof in the presence or absence of an initiator. And modified polyphenylene ether obtained by reacting at a temperature of 30 to 350 ° C. in a molten state, a solution state, or a slurry state.

The polyphenylene ether resin preferably contains 15 to 1% by weight in the base resin.

The phosphate ester compound of b) is a component for imparting flame retardancy to a base resin comprising a rubber-reinforced polystyrene resin and a polyphenylene ether resin of a), and a triphenyl phosphate which is a monomolecular phosphate ester, tri Cresylphosphate, trixylenolphosphate, cresyldiphenyl phosphate, or hydroxyphenyldiphenyl phosphate; Alternatively, triphenyl phosphate represented by the following formula (2), or resorcinol tetracyclyloxy diphosphate represented by the formula (3) can be used.

[Formula 2]

[Formula 3]

The content of the phosphate ester compound is preferably 4 to 30 parts by weight based on 100 parts by weight of the base resin of the rubber-reinforced polystyrene resin and the polyphenylene ether resin.

The calcium stearic acid of c) is a component for imparting dropping property to the rubber-reinforced polystyrene resin and the compound of the polyphenylene ether resin, and in general, since the nonpolar group and the polar group coexist in the polymer, the external lubricant and the internal lubricant are generally used. Used to play a dual role in lubricant.

In the present invention, by adding 0.1 to 10 parts by weight of the calcium stearic acid it was possible to significantly improve the drop-type flame retardancy of the final prepared flame-retardant polystyrene resin composition.

The flame retardant polystyrene resin composition may further include at least one additive selected from the group consisting of antioxidants, heat stabilizers, lubricants, inorganic additives, and pigments.

The present invention will be described in more detail with reference to the following examples and comparative examples. However, an Example is for illustrating this invention and this invention is not limited only to these.

Of the styrene-based resin composition constituents of the examples and comparative examples, only the content of the polyphenylene ether resin (B) and the phosphate ester compound (C) is the rubber-reinforced polystyrene resin (A) and the polyphenylene. The amount is based on 100 parts by weight of the base resin of the ether resin (B), and the other components represent the content of the final polystyrene resin composition.

Preparation and specifications of rubber-reinforced polystyrene resin (A), polyphenylene ether resin (B), phosphate ester compound (C), and calcium stearic acid (D) used in the resin compositions of Examples and Comparative Examples described below are as follows. Same as

1) Rubber-reinforced polystyrene resin (A): The average particle diameter of the rubbery particles of the rubber-reinforced polystyrene resins used in Examples and Comparative Examples of the present invention is 1.5 to 2.0 탆.

2) Polyphenylene ether resin (B): Modified polyphenylene ether having a polyphenylene content of 10 to 90% by weight of Asahi Kasei Co., Ltd., Japan, was used, and the shape was in the form of pellets. The modified polyphenylene ether will be referred to as mPPE (modified Polyphenyl ether) below.

3) Phosphoric acid ester compound (C): The thing of melting | fusing point with the triphenyl phosphate of Great Lakes, Inc. of USA was 48 degreeC.

4) Calcium stearic acid (D): Has the form of white powder.

(Examples 1 to 3 and Comparative Examples 1 to 4)

First of all, in order to minimize volatilization of phosphate ester at a high processing temperature, modified polyphenylene comprising 90 to 10% by weight of rubber-reinforced polystyrene resin and 10 to 90% by weight of pure polyphenylene ether resin The ether resin and the rubber-reinforced polystyrene resin were mixed and processed in a conventional twin screw extruder to lower the high content of the pure polyphenylene ether resin in the whole composition. At this time, the internal temperature of the extruder cylinder was maintained at 240 to 280 ℃. The primary processed resin produced by this extrusion process is called B '. However, in the case of Comparative Example 4, instead of B ', a modified polyphenylene ether resin (B) was not used.

The components of the flame retardant styrenic resin compositions of (A) to (D) described above were blended according to the weight parts given in Table 1 below. In addition to the above components, 0.5 parts by weight of polyethylene having a molecular weight of 2,000 and 0.3 parts by weight of a heat stabilizer were added to prepare a styrene resin composition. The blended resin composition was uniformly mixed with a Hansel mixer and then extruded with a twin screw extruder to obtain a resin composition in pellet form. In the process of extruding with a twin screw extruder, the internal temperature of the twin screw extruder cylinder was maintained at 180 to 200 ℃ to minimize the volatility of the phosphate ester.

Flame-retardant test specimens were obtained by injection molding the polystyrene-based resin composition prepared according to the above method, and 1/8 "specimens were prepared according to the standards of 94V-2, 94V-1, 94V-0 described in items 7 to 10 of UL94. The experiment was conducted and evaluated for flame retardancy.

In addition, the presence of undissolved modified polyphenylene ether (mPPE) was judged by appearance and touch.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 A 85 100 85 60 70 B 'or B 15 0 15 40 30 (use B) C 16 16 16 16 20 D 3 0 3 (PE wax) 15 4 Combustion t ₁ 14 52 36 - 42 t ₂ 2 20 18 - 15 Flame retardancy V-2 failure failure - failure Whether mPPE remains None None None - Occur T ₁ : burning time of the specimen after 10 seconds of first burning t ₂ : burning time of the specimen after 10 seconds of second burning

As shown in Table 1, in the case of the polystyrene-based resin composition specimens of Examples 1 to 3, the flame retardancy evaluation results were not poor, it can be confirmed that the unmelted mPPE does not remain.

Comparing the combustion time, it can be seen that the drop-in flame retardancy significantly improved due to the influence of calcium stearic acid (D). In addition, since the mixture of rubber-modified polystyrene and polyphenylene ether resin to some extent through the first extrusion processing and B 'which reduces the content of polyphenylene ether is used, unmelted mPEE is also reduced even in secondary processing at a relatively low temperature. It did not occur, and the trifonyl phosphate used as the phosphate ester compound in the present invention hardly volatilized to improve the flame retardancy.

In the case of Comparative Example 1, mPPE and calcium stearic acid (D) were not added, so that flame retardancy and dropping ability fell, and the combustion time increased considerably, and thus desired flame retardancy was not obtained.

In the case of Comparative Example 2, low molecular weight polyethylene wax was used instead of calcium stearic acid (D), but the dropping property was insufficient to obtain a desired flame retardancy.

In the case of Comparative Example 3, as the amount of calcium stearic acid (D) was added in a large amount of 15 parts by weight, it was difficult to prepare a pellet as the extrudability during the second extrusion processing, the next experiment was not carried out.

In the case of Comparative Example 4, the first extrusion was omitted, and extruded by adding mPPE (B) which was not diluted directly at a temperature of 260 ° C. As a result, the phosphate ester compound (C) was first melted to act as a lubricant, and mPPE was not sufficiently melted and formed in the form of protrusions on the extrudate. Since phosphate ester also volatilized under high temperature and vacuum, flame retardance was reduced.

The dropping non-halogen flame-retardant styrene resin composition of the present invention is excellent in dropping flame retardancy and non-halogen-based, so that no harmful substances are generated when disposed of.

Claims (8)

a) 85 to 99% by weight of rubber reinforced polystyrene resin; And Ii) 15 to 1% by weight of polyphenylene ether resin 100 parts by weight of a base resin containing; b) 4 to 30 parts by weight of a phosphate ester compound; And c) 0.1 to 10 parts by weight of calcium stearic acid Dropping non-halogen flame-retardant polystyrene-based resin composition comprising a. The dripping non-halogen of claim 1, wherein the dripping non-halogen flame-retardant polystyrene-based resin composition further comprises at least one additive selected from the group consisting of an antioxidant, a heat stabilizer, a lubricant, an inorganic additive, and a pigment. Flame retardant polystyrene resin composition. The dripping non-halogen flame retardant polystyrene resin composition according to claim 1, wherein the rubber-reinforced polystyrene resin of a) i) is a polybutadiene, styrene-butadiene, or butadiene-isoprene copolymer. The dripping non-halogen flame retardant polystyrene resin composition according to claim 1, wherein the rubber component of the rubber-reinforced polystyrene resin of a) i) is 3 to 30% by weight. The dripping non-halogen flame retardant polystyrene resin composition according to claim 1, wherein the polyphenylene ether resin of a) ii) is a homopolymer of a compound represented by the following general formula (1) or a copolymer including the compound of the general formula (1) : [Formula 1] In Formula 1, R ₁ , R ₂ , R ₃ , and R ₄ are each independently or simultaneously chlorine, bromine, iodine, methyl, ethyl, propyl, allyl, phenyl, methylbenzyl, chloromethyl, bromomethyl , Cyanoethyl, cyano, methoxy, phenoxy, or nitro group. The polyphenylene ether-based resin of a) ii) is poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenyl. Ethylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2,6-zipurophyll-1,4-phenylene) ether, poly (2-ethyl-6- Propyl-1,4-phenylene) ether, poly (2,6-dimethoxy-1,4-phenylene) ether, poly (2,6-dichloromethyl-1,4-phenylene) ether, poly (2 , 6-dibromomethyl-1,4-petylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,5-dimethyl-1,4-phenylene) Group consisting of ether, 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / o-cresol copolymer, and 2,3,6-trimethylphenol / o-cresol copolymer Dropping type non-halogen flame-retardant polystyrene resin composition selected from the group consisting of one or more. The method of claim 1, wherein the polyphenylene ether-based resin of a) ii) is an initiator of α, β-unsaturated carboxylic acid or derivatives thereof, styrene or derivatives thereof, and a homopolymer or copolymer of polyethylene ether of formula (1). Dropped non-halogen flame-retardant polystyrene resin composition prepared by the method comprising the step of reacting in the presence or absence of, at a temperature of 30 to 350 ℃, molten state, solution state, or slurry state. According to claim 1, wherein the phosphate ester compound of b) is selected from the group consisting of triphenyl phosphate, trixylenol phosphate, cresyl diphenyl phosphate, and hydroxy phenyl diphenyl phosphate in the form of a single molecule A dropping non-halogen flame retardant polystyrene resin composition which is a compound, a modified compound thereof, or a phosphate ester compound in the condensed form.