JPH0551510A - Flame-retardant, high-impact styrene based resin composition - Google Patents

Abstract

PURPOSE:To provide aflame-retardant, high-impact styrene based resin composition. CONSTITUTION:The title composition comprises a rubber-modified styrene based resin, a polyphenylene ether, a boric acid salt, an organophosphorus compound, and a compound having the skeleton of a triazine. This composition can have greatly improved flame retardancy even when the amounts of the conventional flame retardants are reduced considerably. It is suited for various fields where a high flame retardancy is required, e.g. parts of household appliances and OA apparatus.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition having excellent flame retardancy. More specifically, it relates to a flame-retardant impact-resistant styrene resin composition containing no halogen compound.

[0002]

2. Description of the Related Art Rubber-modified vinyl aromatic resins typified by HIPS are excellent in moldability and dimensional stability, as well as in impact resistance, rigidity, and electrical insulation, and are therefore home appliances and OA. It has come to be used in various fields including equipment parts.

In recent years, the demand for flame retardancy has been increasing for plastic materials used in such fields due to safety concerns, and various flame retardancy standards have been established. Various methods have been devised as a method for imparting flame retardancy to a resin that is easily flammable, but generally, halogen compounds such as bromine compounds having a high flame retardant effect, and antimony oxide if necessary. Is added to the resin. Known bromine compounds include nuclear bromine-substituted aromatic compounds such as decabromodiphenyl ether, tetrabromobisphenol A, and brominated phthalimide.
Although the method by adding these flame retardants can obtain excellent flame retardancy, impact strength and heat distortion temperature decrease, and in some cases the flame retardant bleeds out on the surface of the resin molded product to improve the appearance of the molded product. It had problems such as making it worse. Further, during the molding of the resin, there are problems such that the halogen compound is thermally decomposed to generate a gas harmful to the human body and the mold and the screw are corroded.

For this reason, methods for flame retardation without using halogen compounds have been investigated. As such a method, a method of adding a hydrated metal compound such as aluminum hydroxide or magnesium hydroxide to a resin is known, but in order to obtain sufficient flame retardancy, a large amount of the above hydrated metal compound is added. However, there is a drawback that the original characteristics of the resin are lost.

On the other hand, as a method not using such a hydrated metal compound, a flame-retardant resin composition comprising a nitrogen-containing compound selected from vinyl aromatic resin, polyphenylene ether, organic phosphorus compound, triazine and / or its derivative. Have been proposed (JP-A-54-38348, JP-A-54-34848).
-38349, European Patent 311,909). However, JP-A-54-38348 and JP-A-54-383 are mentioned above.
No. 49, the resin composition described in European Patent No. 311,909 is a useful flame-retardant resin material that does not use any halogen compound, but because it is mainly polyphenylene ether of low fluidity, resin There is a problem that the moldability of the composition is poor.

US Pat. No. 4,456,720 also describes
A resin composition comprising polyphenylene ether, a rubber-modified styrene resin, a brominated flame retardant, and lead borate is disclosed. However, the composition is not only different from the present invention in that it uses a halogen-based flame retardant, but since it is mainly composed of polyphenylene ether having low fluidity, there is a problem that the moldability of the resin composition is poor. It was

[0007]

SUMMARY OF THE INVENTION In view of the above situation, the present invention does not have the above-mentioned problems, that is, the conventional flame retardants can be greatly reduced, and the high flame retardancy and impact resistance are high. An object of the present invention is to provide a styrene resin composition having properties.

[0008]

Means for Solving the Problems As a result of intensive investigations by the present inventors to improve the flame retardancy of styrene resins, the conventional (A)
By combining (C) borate with rubber-modified styrenic resin, (B) polyphenylene ether, (D) organophosphorus compound, and (E) triazine skeleton-containing compound, surprisingly, conventional flame retardants are added. The inventors have found that it is possible to dramatically improve flame retardancy even if the amount is drastically reduced, and arrived at the present invention.

That is, the present invention provides (A) a rubber-modified styrenic resin, (B) polyphenylene ether, (C) borate, (D).
Organic phosphorus compound, and (E) a styrene-based flame-retardant impact-resistant resin composition comprising a triazine skeleton-containing compound, among others,
(A) rubber-modified styrenic resin and (B) polyphenylene ether account for 100 parts by weight of the total of both components (B) component is 10 to 30 parts by weight of the resin component 100 parts by weight, (C) boric acid Salt
1 to 30 parts by weight, 1 to 30 parts by weight of (D) organophosphorus compound, and
(E) A styrene-based flame-retardant impact-resistant resin composition containing 5 to 30 parts by weight of a triazine skeleton-containing compound.

The present invention will be described in detail below.

The resin composition of the present invention comprises (A) a rubber-modified styrene resin, (B) polyphenylene ether, (C) borate, (D) an organophosphorus compound, and (E) a triazine skeleton-containing compound. However, the purpose of the invention cannot be achieved even if any of them is lacking. The component (A) forms the main component of the molding resin composition and plays a role of maintaining the strength of the molded product.The component (D) imparts flame retardancy to the component (A) together with the component (E). In addition, the components of (B) and (C) above are (D)
It is a component for further enhancing the flame retarding effect of the components (E) and (E).

Here, the borate (C) acts as a dehydrating agent, and accelerates the carbonization of the composition by the combination of boric acid (B) produced during combustion and the polyphenylene ether (B).

The rubber-modified styrene resin as the component (A) is a polymer in which a rubber-like polymer is dispersed in particles in a matrix composed of a vinyl aromatic polymer. A known bulk polymerization, bulk suspension polymerization, solution polymerization, or emulsion polymerization of a monomer mixture by adding an aromatic vinyl monomer in the presence thereof and a vinyl monomer copolymerizable therewith, if necessary. Is obtained by

Examples of such resins include high impact polystyrene, ABS resin (acrylonitrile-butadiene-styrene copolymer), AAS resin (acrylonitrile-acrylic rubber-styrene copolymer), AES resin (acrylonitrile-ethylene). Propylene rubber-styrene copolymer) and the like.

Here, the rubber-like polymer must have a glass transition temperature (Tg) of -30 ° C. or lower,
If it exceeds 30 ° C, the impact resistance will decrease.

Examples of such a rubber-like polymer include diene rubbers such as polybutadiene, poly (styrene-butadiene) and poly (acrylonitrile-butadiene), and saturated rubber obtained by hydrogenating the above diene rubber, isoprene rubber and chloroprene rubber. Acrylic rubbers such as polybutyl acrylate, ethylene-propylene-diene monomer terpolymer (EPDM) and the like can be mentioned, and diene rubbers are particularly preferable.

The aromatic vinyl monomer which is an essential component of the graft-polymerizable monomer mixture is, for example, styrene or α.
-Methylstyrene, paramethylstyrene, p-chlorostyrene, p-bromostyrene, 2,4,5-tribromostyrene, etc., with styrene being the most preferable, but mainly other styrene aromatic vinyl monomers. May be copolymerized.

If necessary, one or more monomer components copolymerizable with the aromatic vinyl monomer may be introduced as a component of the rubber-modified styrene resin. When it is necessary to enhance oil resistance, unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile can be used.

When it is necessary to reduce the melt viscosity during blending, an acrylate ester having an alkyl group having 1 to 8 carbon atoms can be used. Furthermore, when it is necessary to further increase the heat resistance of the polymer composition, acrylic acid, methacrylic acid, maleic anhydride, N-
A monomer such as a substituted maleimide may be copolymerized. The content of the vinyl monomer copolymerizable with the vinyl aromatic monomer in the monomer mixture is 0 to 40% by weight.

The rubber-like polymer in the rubber-modified styrenic resin of the present invention is preferably 5 to 80% by weight, more preferably 10 to 50% by weight, and the graft-polymerizable monomer mixture is preferably 95 to 20% by weight. %, More preferably 90 to 50% by weight. Outside this range, the impact resistance and rigidity of the desired polymer composition cannot be balanced. Furthermore, the rubber particle size of the styrene polymer is 0.1 to 5.0 μm.
Is preferable, and 0.2 to 3.0 μm is particularly preferable. Outside the above range, the impact resistance tends to decrease.

The polyphenylene ether of the present invention (hereinafter P
Abbreviated as PE. ) Is a homopolymer and / or a copolymer composed of a bonding unit represented by the following formula.

[0022]

[Chemical 1]

(Here, R ₁ , R ₂ , R ₃ , and R ₄ are each selected from the group consisting of hydrogen, hydrocarbon, and substituted hydrocarbon groups, and may be the same or different from each other. .) As a concrete example of this PPE, poly (2,6
-Dimethyl-1,4-phenylene ether), a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol and the like are preferable, and among them, poly (2,6-dimethyl-1,4
-Phenylene ether) is preferred. The method for producing such PPE is not particularly limited as long as it is obtained by a known method, and for example, a complex of a cuprous salt and an amine by the method described in US Pat. No. 3,306,874 is used as a catalyst, For example, it can be easily produced by oxidative polymerization of 2,6 xylenol.Other than that, U.S. Pat.No. 3,306,875, U.S. Pat.No. 3,257,357, U.S. Pat.No. 3,257,358, and Japanese Patent Publication No. 52-178.
It can be easily produced by the methods described in JP-A No. 80 and JP-A No. 50-51197. The reduced viscosity of the PPE used in the present invention (0.5 g / dl, chlorofilm solution, measured at 30 ° C.) is 0.
It is preferably in the range of 20 to 0.70 dl / g, 0.30 to 0.60
More preferably, it is in the range of dl / g. Examples of means for satisfying the above requirements regarding the reduced viscosity of PPE include adjustment of the amount of catalyst during the production of PPE.

On the other hand, examples of the borate of the present invention include ammonium borate, sodium borate, manganese borate, zinc borate and the like, and zinc borate is particularly preferable. Further, it may be surface-treated with a higher fatty acid, an epoxy resin or the like in order to improve the compatibility with the styrene resin.

Further, as the organophosphorus compound of the present invention, phosphine, phosphine oxide, biphosphine,
Examples thereof include phosphonium salts, phosphinates, phosphoric acid esters, and phosphorous acid esters. More specifically, methyl neopentyl phosphite, pentaerythritol diethyl diphosphite, methyl neopentyl phosphonate, phenyl neopentyl phosphate, pentaerythritol diphenyl diphosphate, dicyclopentyl hypophosphite, dineopentyl hypophosphite. Examples thereof include phyto, phenylpyrocatechol phosphite, ethylpyrocatechol phosphate, dipyrocatechol hypophosphite and the like.

The triazine skeleton-containing compound of the present invention acts as a flame retardant aid for organic phosphorus compounds, and specific examples thereof include melamine, succinoguanamine, adipoguanamine, and methylglutaloganamin. However, melamine is most preferred.

In the resin composition of the present invention, (A) rubber-modified styrenic resin and (B) polyphenylene ether form a resin component, and the proportion of component (B) in 100 parts by weight of the resin component is , 10 to 30 parts by weight is preferable. When the amount of the component (B) is less than 10 parts by weight, the amount of carbonization residue is small and the flame retardancy is insufficient, and when it exceeds 30 parts by weight, the fluidity is deteriorated, which is not preferable. The more preferable range of the component (B) is 10 to 2.
5 parts by weight.

Next, the resin composition of the present invention comprises 1 to 30 parts by weight of (C) borate and (D) organophosphorus compound based on 100 parts by weight of the total of components (A) and (B). Is preferably in the range of 1 to 30 parts by weight, and the (E) triazine skeleton-containing compound is in the range of 5 to 30 parts by weight. If it deviates from the above range, the flame retardancy or impact resistance is lowered, which is not preferable.

The polymer composition of the present invention can be obtained by, for example, melt-kneading each of the above polymers with a commercially available single-screw extruder, a twin-screw extruder, or the like. At that time, BHT is used.
Antioxidants such as, UV absorbers, tin-based heat stabilizers, lubricants such as stearic acid and zinc stearate, fillers, reinforcing materials,
Dyes, pigments and the like can be added as required. By subjecting the composition of the present invention thus obtained to, for example, injection molding or extrusion molding, a molded article having excellent flame retardancy and impact resistance can be obtained.

[0030]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

The measurements in Examples and Comparative Examples were carried out using the following methods or measuring instruments.

(1) Flame Retardancy Evaluation was carried out by the VB (Vertical Burning) method according to UL-94. (1/8 "test piece) (2) Izod impact strength Measured at 23 ° C by a method according to ASTM-D256 (V notch, 1/8" test piece) Example 1 (a) Rubber-modified styrene resin Production of (HIPS) A polymerization stock solution having the following composition was prepared.

Polybutadiene rubber 8.0 parts by weight (NF-35A manufactured by Asahi Kasei Co., Ltd.) Styrene 77.0 parts by weight Ethylbenzene 15.0 parts by weight α-Methylstyrene dimer 0.06 parts by weight Stearyl 3- (3,5-di-shaributyl 0.10 parts by weight- 4-Hydroxyphenyl) -propionate Then, the above stock solution for polymerization was continuously fed to a multistage reactor equipped with a stir bar to carry out polymerization. The polymerization temperature and the stirring number were adjusted so that the weight average particle diameter of the rubber particles was 2.3 μm and the solid content concentration in the final reactor was 80% by weight. Subsequently, it was introduced into a devolatilization device for the polymerization liquid to obtain a rubber-modified vinyl aromatic resin (HIPS) having a rubber content of 10% by weight. As a result of analyzing the obtained rubber-modified vinyl aromatic resin, the gel content was 32% by weight, the swelling index of the gel component was 12.5, and the reduced viscosity of the matrix portion was 0.75 dl / g.

(B) Manufacture of polyphenylene ether (PPE) The inside of a stainless steel reactor having an oxygen blowing port at the bottom of the reactor and having a cooling coil and stirring blades inside was thoroughly replaced with nitrogen, and then brominated. 2,6 in a mixed solvent of 54.8 g of cupric acid, 1110 g of di-n-butylamine, 20 liters of toluene, 16 liters of n-butanol, and 4 liters of methanol.
-Xylenol 8.75Kg was melted and charged into the reactor. Continue to blow oxygen into the reactor while stirring to keep the internal temperature at 30
Polymerization was carried out for 180 minutes while controlling at ℃. After completion of polymerization
The precipitated polymer was separated by filtration, a methanol / hydrochloric acid mixture was added to decompose the residual catalyst in the polymer, and the polymer was thoroughly washed with methanol and then dried to obtain a powdery PPE. The reduced viscosity was 0.55 dl / g.

(C) Borate A commercially available borate (Zinc Borate 2335 manufactured by Borax Chemical Co.) was used as a borate (referred to as ZB).

(D) Organic phosphorus compound Commercially available triphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.) was used as the organic phosphorus compound (referred to as TPP).

(E) Triazine skeleton-containing compound As the triazine skeleton-containing compound, commercially available melamine (manufactured by Wako Pure Chemical Industries, Ltd.) was used (referred to as ML).

(F) Preparation and Evaluation of Compositions The above HIPS / PPE / ZB / TPP / ML were mechanically mixed in a weight ratio of 77/23/8/12/12, and a Laboplast manufactured by Toyo Seiki Seisakusho Co., Ltd. Using a mill, melting was performed at a melting temperature of 230 ° C. and a rotation speed of 50 rpm for 5 minutes. A 1/8 "-thick test piece was prepared from the polymer composition thus obtained by hot pressing, and its flame retardancy and Izod impact strength were evaluated. Table 1 shows the results.

Comparative Example 1 The same experiment as in Example 1 was repeated except that ZB was not added. The results are shown in Table 1.

Comparative Example 2 Example 1 was repeated except that TPP was not added.
The same experiment was repeated. The results are shown in Table 1.

Comparative Example 3 The same experiment as in Example 1 was repeated except that ML was not added in Example 1. The results are shown in Table 1.

Comparative Example 4 The same experiment as in Example 1 was repeated except that the HIPS / PPE 77/23 weight ratio resin component 100 in Example 1 was changed to HIPS100. (However, the ratio of each additive to the rubber-modified styrenic resin component was the same as in Example 1) Table 1 shows the results.

[0043]

[Table 1]

[0044]

The composition of the present invention is a styrenic resin composition which has a high degree of flame retardancy and impact resistance even if the conventional flame retardant is largely reduced. This composition is for home appliances parts, OA
It is suitable for equipment parts and plays a major role in the industrial world.

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Claims (1)

[Claims] 1. A rubber-modified styrenic resin, (B) polyphenylene ether, (C) borate, (D) organic phosphorus compound,
And (E) a styrene flame-retardant impact-resistant resin composition comprising a triazine skeleton-containing compound.