JPH06157849A - Flame-retardant thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. excellent in clarity and flame retardancy by compounding a styrene-(meth)acrylic acid copolymer with specific org. and inorg. flame retardants. CONSTITUTION:This resin compsn. is obtd. by compounding a copolymer essentially comprising styrene units and (meth)acrylic acid units with an org. flame retardant selected from the group consisting of ones based on halogenated diphenyl oxide and ones based on halogenated bisphenol (e.g. decabromodiphenyl oxide) and an inorg. flame retardant (e.g. antimony trioxide). The use of both the org. and inorg. flame retardants gives the compsn. excellent clarity and flame retardancy, while the styrene-methacrylic acid copolymer, widely used as a styrenic resin inherently excellent in heat resistance and clarity, is liable to lose its clarity when compounded with an org. or inorg. flame retardant.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to molding of various molded articles required to have flame retardancy, for example, various fields such as electric, electronic, OA, communication, audio, video, automobile, vehicle, machine and the like. The present invention relates to a resin composition suitable as a material.

[0002]

2. Description of the Related Art Styrenic resins are used in various fields because they exhibit various excellent physical properties such as moldability.

A styrene-methacrylic acid copolymer has been widely used as a styrene-based resin which is particularly excellent in heat resistance and transparency.

[0004]

However, regarding the flame retardation of the above-mentioned conventional styrene-methacrylic acid copolymers, organic flame retardants or inorganic flame retardants have hitherto been used as in the case of ordinary styrene resins. When a flame retardant is used, the transparency which is a characteristic of the styrene-methacrylic acid copolymer is lost, and thus there is a problem that both transparency and flame retardancy cannot be imparted to the copolymer so far. It was

The problem to be solved by the present invention is to provide a thermoplastic resin composition mainly composed of a copolymer having styrene and (meth) acrylic acid as essential components, which is excellent in transparency and flame retardancy. To do.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a specific organic compound can be added to a copolymer containing styrene and (meth) acrylic acid as essential components. It has been found that the above problems can be solved by blending a flame retardant and an inorganic flame retardant, and the present invention has been completed.

That is, the present invention is an organic system selected from the group consisting of a copolymer (A) containing styrene and (meth) acrylic acid as essential components, a halogenated diphenyl oxide flame retardant and a halogenated bisphenol flame retardant. It relates to a flame-retardant thermoplastic resin composition containing a flame retardant (B) and an inorganic flame retardant (C).

The copolymer (A) containing styrene and (meth) acrylic acid as essential components used in the present invention contains styrene and (meth) acrylic acid as essential components, and is further copolymerized with these as required. It is a copolymer resin composed of other possible monomers. In the copolymer (A), the polymerization rate of styrene and (meth) acrylic acid is styrene / (weight ratio).
It is preferable that (meth) acrylic acid is in the range of 50/50 to 90/1 from the viewpoint of excellent heat resistance improving effect.
Above all, the melt viscosity of the polymer is kept low, and the heat resistance,
The polymerization rate is preferably in the range of 60/40 to 97/3 from the viewpoint of excellent appearance of the molded product, affinity with the flame retardant, and the like.
In particular, it is preferably within the range of 70/30 to 95/5.

Other monomers copolymerizable with styrene and (meth) acrylic acid include, for example, vinyl-cyan compounds represented by acrylonitrile and methacrylonitrile; itaconic acid, maleic acid, fumaric acid, crotonic acid, cinnamic acid. Polymerizable unsaturated fatty acids represented by N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-octylmaleimide, N-isopropylmaleimide, N-phenylmaleimide, NP-bromophenylmaleimide, N- Unsaturated carboxylic acid anhydrides typified by maleimidic acid typified by O-chlorophenylmaleimide and N-cyclohexylmaleimide, maleic anhydride, itaconic anhydride, citraconic anhydride, etc .; allyl glycidyl ether, glycidyl methacrylate Epoki represented by Group-containing unsaturated compounds; amino group-containing unsaturated compounds represented by allylamine, aminoethyl methacrylate, -aminopropyl methacrylate, aminostyrene; acrylamide compounds represented by acrylamide and N-methylacrylamide; 2-hydroxy Examples thereof include, but are not limited to, a hydroxyl group-containing unsaturated compound such as ethyl-acrylate, 3-hydroxypropylmethacrylate, and 4-hydroxy-2-butene. These other monomers are
One kind or a combination of two or more kinds may be used for the polymerization.

Further, these other monomers are used within a range in which the affinity of the copolymer (A) and the organic flame retardant (B) is lowered and the effect of the present invention is not lowered. This copolymer resin (A) is produced by a commonly used production method, for example, Japanese Patent Laid-Open No.
0-106818, JP-A-60-168710, JP-A-61-43612, JP-A-61-1.
It can be easily produced by the methods exemplified in JP-A-63949 and JP-A-62-74908.

Specifically, in the presence or absence of a commonly used radical catalyst or ionic catalyst,
Emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, or emulsion-suspension polymerization, emulsion-solution polymerization, suspension-solution polymerization method, etc., batch, continuous or batch-continuous production method. be able to. For example, a styrene monomer and methacrylic acid are optionally added with another monomer copolymerizable with them, and a radical generator and a chain transfer agent are used, and the temperature is 60 to 180 ° C., preferably 7.
Suspension polymerization or bulk polymerization at 5 to 120 ° C., and then additives such as antioxidant, plasticizer, flame retardant, antistatic agent, mineral oil, etc., if necessary, and granulated by an extruder or the like. There is a method such as.

The polymer chain structure of the copolymer (A) produced by these production methods is not particularly limited, and may be a random copolymer, a block copolymer or a graft copolymer. May be Further, the weight average molecular weight (Mw) of this copolymer resin (A)
Is usually preferably 30,000 to 500,000.

The copolymer (A) thus obtained
Is a polymer obtained by previously treating a part of the carboxyl groups present in the molecule with an acid anhydride, a modified polymer with a glutaric anhydride group, and alkali metal, alkaline earth metal, etc. by taking advantage of the characteristics of the carboxy group. Ion-crosslinked polymers, modified polymers obtained by forming amide bonds and ester bonds with amide group-containing compounds, hydroxyl group-containing compounds and the like are also included in the copolymer (A) used in the present invention. is there.

The organic flame retardant (B) used in the present invention is not particularly limited as long as it is selected from the group consisting of halogenated diphenyl oxide flame retardants and halogenated bisphenol flame retardants. Bromides are preferred because of their excellent flame retardant effect.

As the halogenated diphenyl oxide flame retardant, for example, decabromodiphenyl oxide (D
BDPO), hexabromodiphenyl oxide, tetrabromodiphenyl ether (TBDPE), polydibromophenylene oxide, octabromodiphenyl ether, hexabromodiphenyl ether, tetrabromodiphenyl ether, tetrabromodiphenyl ether, pentabromodiphenyl ether and the like.

On the other hand, halogenated bisphenol flame retardants include tetrabromobisphenol A (TBBA), tetrabromobisphenol S (TBS), bishydroxyethyl ether TBA and bisbromoethyl ether T.
BA, tetrabromobisphenol A bis (2,3-dibromopropyl ether), tetrabromobisphenol A bis (allyl ether) and the like can be mentioned.

Of these, decabromodiphenyl oxide is particularly preferable because of its excellent transparency and flame retardancy.

The inorganic flame retardant (C) is not particularly limited, and examples thereof include aluminum hydroxide, antimony trioxide, antimony pentoxide, magnesium hydroxide, nitrogenated guanidine, zinc borate and zirconium.

Among these, antimony-based flame retardants such as antimony trioxide and antimony pentoxide are preferable in terms of synergistic effect with the flame retardant and excellent surface appearance. Further, in the present invention, if the antimony-based flame retardant has a relatively large particle size, the dispersibility thereof is poor, which causes problems such as unevenness on the surface of the molded product and deterioration of the surface gloss. Therefore, the average particle size of the antimony-based flame retardant is preferably 7 μm or less, because the dispersibility of the antimony-based flame retardant can be remarkably improved and the surface condition of the molded product can be extremely improved.

Among them, those having an average particle size of 0.1 to 7 μm are more preferable because the discharge amount at the time of extrusion molding is stable and the workability is improved. The inorganic flame retardant (C) is
Further, the surface treatment with an inorganic oxide can prevent generation of silver or the like due to the interaction between the inorganic flame retardant (C) and the copolymer (A), and the appearance of the molded product can be further improved. preferable.

The inorganic oxide used here is not particularly limited, but silicon oxide and titanium oxide are preferable from the viewpoint that the appearance of the molded product is remarkably improved. The amount of the inorganic oxide used for the surface treatment is not particularly limited, but it is preferable that the amount is 1% by weight or more based on the total amount of the antimony-based flame retardant, because this effect becomes remarkable. .

Specific examples of the surface treatment include, for example, the method described in Japanese Patent Publication No. 50-14254 when silicon oxide is used, while when titanium oxide is used, an antimony-based flame retardant is used. After impregnating with titanium oxide, a method of firing at 200 ° C. in an oxygen atmosphere can be mentioned.

Further, the content of impurities such as Fe in the antimony-based flame retardant is preferably less than 100 ppm from the viewpoint of preventing silver from being generated. Also, focusing on the silver prevention effect, the antimony-based flame retardant having an impurity content of less than 100 ppm and being surface-treated with an inorganic oxide has a more remarkable silver prevention effect. Very preferable.

The flame-retardant thermoplastic resin composition of the present invention contains each of the above-mentioned components. The mixing ratio of them is, for example, the organic flame-retardant (B) with respect to the copolymer (A). And the blending ratio of the inorganic flame retardant (C) is usually (A) / [(B) + (C)] = 90/10 to 50 / by weight ratio.
It is preferably 50, and in particular 80/20 to 60/4 from the viewpoint of excellent balance of flame retardancy, heat resistance and transparency.
It is more preferably 0. In addition, organic flame retardant (B)
The compounding ratio of the inorganic flame retardant (C) is usually 99/1 to 50
/ 50, among which 99/1 to 80/20 from the viewpoint of excellent balance of flame retardancy, moldability, surface condition of molded products, etc.
Is more preferable.

The composition of the present invention contains the above-mentioned copolymer (A), organic flame retardant (B), and inorganic flame retardant (C) as essential components, but has a better compatibility with the resin and the organic compound. Polysiloxane, plasticizer, mineral oil, commonly used antioxidants,
Compounding agents such as an ultraviolet absorber, a lubricant and an antistatic agent may be added.

Examples of the resin having good compatibility include (meth)
Acrylic esters, especially polymethylmethacrylate, styrene-methylmethacrylate copolymer are desirable, but are not limited to these, polyphenylene ether, styrene-maleic anhydride copolymer resin, styrene-acrylonitrile copolymer resin and the like. May be.

The method for producing the composition of the present invention includes:
There is no particular limitation, and a commonly used manufacturing method can be used. Specifically, for example, a method of applying the above-mentioned respective components to a melt-kneader with a heating roll, a Banbury mixer, a single-screw extruder, a twin-screw extruder, a single-screw-twisted extruder or the like can be mentioned.

The resin composition of the present invention thus obtained is further subjected to injection molding; film, sheet by axial, uniaxial stretching, biaxial stretching, etc .; board extrusion molding, vacuum molding, pressure molding, modified molding, It can be used by molding into various molded products by extrusion foam molding, blow molding and the like.

The composition of the present invention has a wide range of uses, including connectors, switches, timer parts, terminal blocks,
Adapters, relay parts, transformer parts, motor parts, and other parts in the electric and electronic fields and cases, air conditioners, refrigerators, television sets, warm air, humidifiers, etc. Housing: Copiers, printers, fax machines, CRT displays, personal computers, word processors, computers, various parts of office automation equipment such as registers, housings, automobile interiors, exterior parts and body parts; general machines such as pumps, fans, electric tools, etc. Parts, cases, building materials, etc.

For each of the above applications, the thermoplastic resin composition of the present invention is prepared by injection molding; film, sheet, board extrusion molding by non-axial or uniaxial stretching, vacuum molding, pressure molding, profile molding, hollow molding and the like. It can be used as various molded products.

[0031]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
The parts and% shown below are based on weight unless otherwise specified.

Various evaluation tests were conducted according to the following evaluation criteria. [Transparency] 0.3mm width H through 2mm thick plate
It was visually evaluated whether or not the B line could be identified.

⊚: No HB line at all ◯: HB line is hardly observed ×: Distinguishable [flame retardancy test] In accordance with UL-94 standard. [Dispersibility] The surface condition of the molded product was evaluated according to the following criteria.

◯: No unevenness on the surface, good gloss ×: Fine unevenness on the surface, poor gloss [Silver] It was visually evaluated according to the following criteria.

⊚: None of the plurality of samples is recognized at all. ◯: A slight amount of silver can be confirmed at a ratio of 1 out of 5 samples.

X: Clear silver appeared in all of the plurality of samples. Reference Example 1 2000 ml of distilled water was charged into a 5 liter stainless steel reactor equipped with a turbine-type stirring blade, 10 g of partially saponified polyvinyl alcohol and 0.05 gr of sodium dodecylbenzenesulfonate were dissolved as a suspension stabilizer, and 870 gr of styrene, Methacrylic acid 130 gr, liquid paraffin 10 gr, di-tert-butyl peroxyhexahydroterephthalate 4 g, and perbenzoic acid-tert.
-Butyl 1 gr was sequentially charged. After replacing the inside of the vessel with nitrogen gas, the temperature was raised under stirring at 500 rpm, suspension polymerization was carried out at 90 ° C. for 10 hours, and further reaction was carried out at 120 ° C. for 3 hours. The produced granular styrene-methacrylic acid copolymer was washed, dehydrated and then dried. This is referred to as a copolymer (A-1).

Reference Examples 2 to 4 Reference Example 1 except that each monomer was used in the composition shown in Table 1.
Copolymers (A-2) to (A-4) were obtained in the same manner as.
Table 1 shows the measurement results of the weight average molecular weights (Mw) of (A-1) to (A-4).

[0038]

[Table 1] Examples 1 to 4 and Comparative Examples 1 to 3 Each component was blended in a tumbler according to the formulations shown in Tables 2 and 3, and then a 30 mmφ single screw extruder (temperature 2
The pellets were obtained by melting, kneading and extruding at 20 to 250 ° C. A color plate was molded using the pellets (temperature: 250 ° C., mold temperature: 60 ° C.) and various evaluation tests were performed.
The results are shown in Tables 3 and 4.

[0039]

[Table 2]

[0040]

[Table 3] In Table 2, S-102 is decabromodiphenyl ether manufactured by Ethyl Corporation, and TBA is tetrabromobisphenol A "FG200 manufactured by Teijin Chemicals."
0 "and B-TBA are Tetrajin Bisphenol A bis (2-hydroxyethyl ether)" F
G-3600 "and BT-93 represent ethylene bis tetrabromophthalimide manufactured by Ethyl Corporation.

The flame retardants A to F are as follows. A: Antimony trioxide “UF” manufactured by Sumitomo Metal Mining Co., average particle size 3.2 μm B: Antimony trioxide “100A” manufactured by Dowa Mining Co., average particle size 1.0 μm C: Antimony pentoxide “NA” manufactured by San Epoque -301
0 ”D: Antimony trioxide“ ATOX-B ”manufactured by Nippon Seiko Co., Ltd.,
Average particle size 0.8 μm E: Antimony trioxide "PATOX-" manufactured by Nippon Seiko Co., Ltd.
L ”, average particle size 8 μm F: SiO 2 surface-treated antimony trioxide, average particle size 3 μm

[0042]

Industrial Applicability According to the present invention, it is possible to provide a thermoplastic resin composition mainly composed of a copolymer having styrene and (meth) acrylic acid as essential components, which is excellent in transparency and flame retardancy.

Claims (7)

[Claims] 1. An organic flame retardant selected from the group consisting of a copolymer (A) containing styrene and (meth) acrylic acid as essential components, a halogenated diphenyl oxide flame retardant and a halogenated bisphenol flame retardant ( B) and an inorganic flame retardant (C) are contained, The flame-retardant thermoplastic resin composition characterized by the above-mentioned. 2. The composition according to claim 1, wherein the organic flame retardant (B) is selected from the group consisting of brominated diphenyl oxide flame retardants and brominated bisphenol flame retardants. 3. The composition according to claim 2, wherein the organic flame retardant (B) is decabromodiphenyl oxide. 4. The composition according to claim 1, 2 or 3, wherein the inorganic flame retardant (C) is an antimony flame retardant. 5. The composition according to claim 4, wherein the inorganic flame retardant (C) has an average particle size of 0.1 to 7 μm. 6. The composition according to claim 4, wherein the inorganic flame retardant (C) is surface-treated with an inorganic oxide. 7. The composition according to claim 1, further comprising an organic polysiloxane.