JPH0826215B2 - Flame-retardant polyphenylene ether resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-retardant polyphenylene ether resin composition, and more specifically, a polyphenylene ether resin,
The present invention relates to a flame-retardant polyphenylene ether resin composition containing a vinyl aromatic hydrocarbon resin, a metal salt of phosphoric acid, and a phosphate compound.

[Conventional technology]

Polyphenylene ether is a resin excellent in various properties such as heat resistance, rigidity, and electrical characteristics, and is widely used as a useful engineering plastic. However, polyphenylene ether is inferior in moldability and impact resistance, and further flame retardancy is not sufficient in itself.

The technology of blending styrene resin or elastomer-reinforced styrene resin, and various elastomers for the purpose of improving molding processability and impact resistance is disclosed in US Patent No.
It is disclosed in various documents such as the specification of 3,383,435. However, it is well known that the flame retardancy of polyphenylene ether is greatly impaired by adding a styrene resin or an elastomer.

Therefore, in order to use a polyphenylene ether or a resin composition composed of a polyphenylene ether and a styrene resin and / or an elastomer in an application requiring flame retardancy, it is necessary to blend a flame retardant. It is also well known that The flame retardants that have been recognized to be effective in the past are mainly phosphorus-containing compounds and halogen-containing compounds.

For example, JP-A-49-32947, JP-A-53-73248, JP-A-55-16081 and JP-A-57-30737 propose the use of aromatic phosphates. ing.

Phosphoric acid esters, when added to polyphenylene ether as a flame retardant, exert excellent flame retardant effect and further improve moldability due to plasticizing effect, but on the other hand, heat resistance such as heat distortion temperature It is unavoidable that the mechanical strength such as elasticity or tensile strength is significantly reduced, and the more serious problem is that these phosphoric acid esters volatilize from the resin phase during the molding process, contaminating the mold, and eventually molding. It is also a loss of appearance. This is because the molding processing temperature of the molding material containing polyphenylene ether requires a relatively high temperature of 250 to 300 ° C., which poses a serious problem in practical use. Taking triphenyl phosphate and tricresyl phosphate as examples, about 20% of them may volatilize even when kneaded into the resin phase when heated to around 300 ° C. As a technique for solving such a problem of volatility of phosphoric acid esters, JP-A-55-1189557 proposes the use of an aromatic phosphoric acid ester polymer.

On the other hand, there are many known techniques for halogen-containing compounds, for example, JP-A-48-7945 proposes a method of blending hexabromobenzene and antimony oxide,
JP-B-48-39014 and JP-A-52-57255 disclose a method of adding a similar aromatic halogen compound. Halogen-containing compounds have almost no plasticizing effect on polyphenylene ether, and when blended with polyphenylene ether, the fact that they do not impair the heat resistance is an excellent feature not found in phosphate esters. However, on the other hand, the fact that the molding processability is not improved is a drawback. Furthermore, when a halogen-containing compound is used as a flame retardant, blooming occurs due to migration of the halogen-containing compound to the surface of the molded product, and corrosion of the molding machine or mold due to the thermal decomposition product of the halogen-containing compound. It is well known that problems can occur.

Furthermore, Japanese Patent Publication No. 48-38768 discloses a method of using a phosphoric acid ester and an aromatic halogen compound in combination, and even in this method, the essential effect brought about by the use of a phosphoric acid ester and a halogen-containing compound is disclosed. However, it has not improved the major drawbacks.

[Problems to be solved by the invention]

The present inventors have found that when a conventionally known phosphorus-containing compound or halogen-containing compound is blended as a flame retardant in a polyphenylene ether resin or a resin composition of a polyphenylene ether resin and a polystyrene resin, As a result of conducting investigations to solve the above drawbacks by means different from the known art, the following was found and the resin composition of the present invention was reached. That is, i) the metal salt of phosphoric acid described below alone does not have a flame retarding effect on the polyphenylene ether-based resin composition, and ii) the combined use of the metal salt of phosphoric acid and a phosphate compound results in synergistic flame retardancy. Since the effect is exhibited, the amount of the phosphate compound used can be reduced as compared with the case where the phosphate compound is used alone. iii) Since the heating weight loss of the metal phosphate is smaller than that of the usual phosphate compound, the heating weight loss of the flame retardant as a whole can be reduced in combination with the reduction of the usage amount of the phosphate compound due to the combined use.

[Means for solving problems]

The resin composition of the present invention comprises (a) a polyphenylene ether resin, (b) a vinyl aromatic hydrocarbon resin, (c) a metal salt of phosphoric acid represented by the following general formula (I), and (d) a phosphate. A flame-retardant polyphenylene ether resin composition containing a compound.

M: Ca, Ba, Al R ₁ , R ₂ , R ₃ , R ₄ : C _1-3 alkyl group l, m, n, o: 0 or an integer 1-5 p: M when Ca or Ba Is 1 when M is Al. The polyphenylene ether resin used as the component (a) in the resin composition of the present invention is a monocyclic phenol represented by the general formula (II). (In the formula, R ₅ is a lower alkyl group having 1 to 3 carbon atoms, R ₆ and
R ₇ is a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms. ) A polyphenylene ether obtained by oxidative polycondensation of one or more of the above; and a graft copolymer having a polyphenylene ether as a backbone obtained by graft-polymerizing a vinyl aromatic compound on the polyphenylene ether. To do. The polyphenylene ether may be a homopolymer or a copolymer.

Examples of the monocyclic phenol represented by the general formula (II) include 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-dipropylphenol, 2-methyl-6-ethylphenol and 2 -Methyl-6-propylphenol, 2-ethyl-6-propylphenol, m-
Cresol, 2,3-dimethylphenol, 2,3-diethylphenol, 2,3-dipropylphenol, 2-methyl-3-ethylphenol, 2-methyl-3-propylphenol, 2-ethyl-3-methylphenol , 2-ethyl-3-propylphenol, 2-propyl-3-methylphenol, 2-propyl-3-ethylphenol, 2,3,6-trimethylphenol, 2,3,6-triethylphenol, 2,3, 6-tripropylphenol, 2,6-dimethyl-3-ethylphenol, 2,6-dimethyl-3-
Examples include propylphenol and the like. And, as the polyphenylene ether obtained by polycondensation of one or more of these monocyclic phenols, for example, poly (2,6-
Dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-dipropyl-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, 2,6- Dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, 2,6-diethylphenol / 2,3,6-trimethylphenol copolymer Polymer, 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer, graft copolymer obtained by graft-polymerizing styrene to poly (2,6-dimethyl-1,4-phenylene) ether, 2 , 6-Dimethylphenol / 2,3,6-trimethylphenol Graft copolymers of styrene on Nord copolymer obtained by graft polymerization, and the like. In particular, poly (2,6-dimethyl-1,4-phenylene) ether, 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, and a graft copolymer obtained by graft-polymerizing styrene to the former two, respectively. Polymers are preferred as the polyphenylene ether resin used in the present invention.

In the resin composition of the present invention, the polyphenylene ether resin and the vinyl aromatic hydrocarbon resin as the component (b) forming the resin composition have the following general formula (III) (In the formula, R ₈ is a hydrogen atom or a lower alkyl group, Z is a halogen atom or a lower alkyl group, and q is 0 or 1
Is a positive integer of ˜3. ) Is a resin containing at least 25% by weight or more of the structural unit represented by Examples of such polystyrene resins include polystyrene, rubber-modified polystyrene (impact-resistant polystyrene), poly-p-methylstyrene, rubber-modified poly-p-methylstyrene, styrene-putadiene copolymer, styrene-butadiene-acrylonitrile copolymer. , Styrene-acrylic acid rubber-acrylonitrile copolymer, styrene-α-methylstyrene copolymer, styrene-butadiene block copolymer, styrene-maleic anhydride copolymer, rubber-modified styrene-maleic anhydride copolymer, and the like. You may use it.

The metal salt of phosphoric acid represented by the general formula (I), which is the component (c) of the resin composition of the present invention, is disclosed in JP-A-59-145224.
It is produced according to the method for producing a partial metal salt of a phosphoric acid ester disclosed in JP-A No. That is, first, the phenols are reacted with phosphorus oxychloride or phosphoric anhydride (temperature 150 to 2
(00 ° C., reaction time 2 to 15 hours) and then hydrolyzed to give the formula: A phosphoric acid ester represented by Next, according to a general method for synthesizing a fatty acid metal salt, the phosphoric acid ester is neutralized with 1.0 to 1.1 times equivalent amount of alkali (for example, sodium hydroxide) equivalent to a strong acid value, and then calcium, barium, and aluminum are added. A compound represented by the general formula (I) by adding an inorganic acid metal salt (for example, calcium chloride, barium chloride, aluminum sulfate, etc.) in an equivalent amount of the above-mentioned alkali necessary for neutralization or a slight excess thereof to undergo metathesis. Is generated.

In the general formula (I), R ₁ , R ₂ , R ₃ and R ₄ are each independently a C _1-3 alkyl group, that is, a methyl group, an ethyl group, a propyl group or an isopropyl group, and l ,
m, n, and o are each independently 0 or an integer of 1 to 5. Therefore, specific examples of the phenols used for producing the metal salt of phosphoric acid represented by the general formula (I) include phenol, cresol, xylenol, trimethylphenol, tetramethylphenol, pentamethylphenol and ethyl. Phenol, propylphenol,
Examples thereof include isopropylphenol, diethylphenol, triisopropylphenol and the like, and these may be used alone or in combination.

The metal forming the metal salt is calcium, barium, or aluminum, and when the metal is aluminum, one unesterified hydroxyl group must remain.

As the phosphate compound which is the component (d) of the resin composition of the present invention, those represented by the following general formula (IV) are preferable. Specifically, phenyl-bis (R ₉ , R ₁₀ and R ₁₁ are each independently an alkyl group, a cycloalkyl group, an allyl group, an alkyl-substituted allyl group, an allyl-substituted alkyl group, hydrogen, etc.) (Dodecyl) phosphate, phenyl-bis ( Neopentyl) phosphate, phenyl-ethyl-hydrogen phosphate, phenyl-bis (3,5,5-trimethylhexyl) phosphate, ethyl-diphenyl phosphate, bis (2-ethylhexyl) -P-triphosphate, tritolyl phosphate , Bis (2-ethylhexyl) -phenyl phosphate, tri (nonylphenyl) phosphate, phenyl-methyl-hydrogen diphosphate, di (dodecyl) -P-tolyl phosphate, tricresyl phosphate, triphenyl phosphate, Tri (isopropylphenyl) phosphine Ate, a phosphate obtained from a mixture of isopropylphenol and phenol, dibutyl-phenylphosphate,
P-tolyl-bis (2,5,5-trimethylhexyl) phosphate, 2-ethylhexyl-diphenyl phosphate, diphenyl-hydrogen phosphate, halogenated triphenyl phosphate, 2-chloroethyl-diphenyl phosphate, tris (Β-naphthyl) phosphate, tris (P-phenylphenyl) phosphate, and the like. Further, examples of the phosphate compound not represented by the general formula (IV) include a phosphate polymer having two or more phosphorus atoms in one molecule, which is obtained from a mixture of phenol and resorcin.

In the resin composition of the present invention, the amounts of the metal salt of phosphoric acid represented by the general formula (I) and the phosphate compound used vary depending on the ratio of the resin components and / or the degree of flame retardancy required for the resin composition. However, in general, the total amount of both is 1 to 50 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the resin component (including the elastomer).
If it is less than the lower limit amount, it is difficult to achieve a predetermined degree of flame retardancy, and if it exceeds the upper limit amount, other performance is impaired. The ratio (weight ratio) of the metal salt of phosphoric acid represented by the general formula (I) to the phosphate compound is generally 10/90 to 8
0/20, preferably 20/80 to 70/30, more preferably 40/60
~ 65/35. When the proportion of the compound represented by the general formula (I) is high, it is difficult to achieve a predetermined degree of flame retardancy. On the contrary, when the proportion of the phosphate compound is high, the volatilization loss from the resin composition during heating is generally high. Will increase.

Ratio of polyphenylene ether resin to vinyl aromatic hydrocarbon resin (weight ratio) in the resin composition of the present invention
Regarding, generally 1/99 to 99/1, preferably 10/90
90 to 90/10, more preferably 20/80 to 80/20.

The resin composition of the present invention, various additives, depending on the purpose,
It is possible to mix other ingredients such as fillers and elastomers. For example, stabilizers such as sterically hindered phenols, organic phosphites, phosphonites, phosphonasic acids, cyclic phosphonites, hydrazine derivatives, amine derivatives, carbamate derivatives, thioethers, phosphotrictriamides, benzoxazole derivatives, and metal sulfides; benzotriazole. UV absorbers such as derivatives, benzophenone derivatives, salicylate derivatives, sterically hindered amines, and oxalic acid diamide derivatives; olefin waxes as lubricants represented by polyethylene wax, polypropylene wax; decabromobiphenyl, pentabromo Brominated flame retardants represented by toluene, decabromobiphenyl ether, brominated polystyrene, etc .; pigments represented by titanium oxide, zinc oxide, carbon black, etc.
Inorganic fillers typified by glass fibers, glass beads, asbestos, wollastonite, mica, talc, clay, calcium carbonate, silica, etc .; metal flakes typified by flakes such as copper, nickel, aluminum, zinc; aluminum fibers, aluminum Examples thereof include metal fibers typified by alloy fibers, brass fibers, stainless fibers, carbon fibers, and organic fillers typified by aromatic polyamide fibers.

Further, the elastomer is an elastomer in a general sense, for example, “Properties and AV” by AV Tobolsky.
Structures of Polymers "(John WILEY & Sons, Inc.,
1960) The definition adopted on pages 71 to 78 can be quoted, and elastomer has a Young's modulus at room temperature of 10 ⁵ to 10 ⁹ dynes /
It means a polymer that is cm ² (0.1 to 1020 Kg / cm ² ). Specific examples of the elastomer include AB-A 'type elastomeric block copolymers, A-B-A' type elastomeric block copolymers in which the double bond of the polybutadiene portion is hydrogenated, polybutadiene, polyisoprene. , A copolymer of a diene compound and a vinyl compound, a radial tereblock copolymer, a nitrile rubber, an ethylene-propylene copolymer, an ethylene-propylene-diene copolymer (EPD
M), thiochol rubber, polysulfide rubber, acrylic acid rubber, polyurethane rubber, graft copolymer of butyl rubber and polyethylene, polyester elastomer, polyamide elastomer, polyurethane elastomer and the like. Above all, an AB-A 'type elastomeric block copolymer is preferable. The terminal blocks A and A'of this block copolymer are polymerized vinyl aromatic hydrocarbon blocks, and B is a polymerized conjugated diene block or a polymerized conjugated diene block in which most of the double bonds are hydrogenated. Desirably, the molecular weight of the B and B blocks is greater than the combined molecular weight of the A and A'blocks. The end blocks A and A'may be the same or different and the blocks are thermoplastic homopolymers or copolymers derived from vinyl aromatic hydrocarbons whose aromatic moieties may be monocyclic or polycyclic. . Examples of such vinyl aromatic hydrocarbons include styrene, α-methylstyrene, vinyltoluene, vinylxylene, ethylvinylxylene, vinylnaphthalene and mixtures thereof. The central block B is a conjugated diene hydrocarbon, such as
It is an elastomeric polymer derived from 1,3-butadiene, 2,3-dimethylbutadiene, isoprene, 1,3-pentadiene and mixtures thereof. Block A at each end
And the molecular weight of A'is preferably about 2,000 to about 100,000.
While the molecular weight of central block B is preferably in the range of about 25,000 to about 1,000,000. The blending amount of the elastomer is 0 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 3 to 5% by weight based on the total amount of the polyphenylene ether resin and the vinyl aromatic hydrocarbon.

In preparing the polyphenylene ether resin composition of the present invention, a conventionally known method may be adopted, for example, after mixing the components with a high speed mixer typified by a turnbull mixer or a Hensiel mixer. A mixing method using a Banbury mixer or the like is appropriately selected.

〔Example〕

Hereinafter, the resin composition of the present invention will be specifically described with reference to Reference Examples, Examples and Comparative Examples. The number of parts is part by weight unless otherwise specified.

Reference Example The heating weight loss of the following metal salts of phosphoric acid synthesized according to the method described above was measured.

Measurement conditions Equipment: TG-8110 (Rigaku Denki) Temperature rise: 10 ° C / min Atmosphere: Pressurized air The weight loss of each of the above substances from room temperature to 300 ° C was as follows. Values for triphenyl phosphate are also shown for comparison.

TPP 79% A) 9.4% B) 6.9% C) 9.4% D) 5.9% As is clear from the above results, the decrease in weight by heating of the metal salt of phosphoric acid used in the resin composition of the present invention has hitherto been known. Much smaller than in the case of triphenyl phosphate.

Examples 1 to 3, 2, 6 having an intrinsic viscosity of 0.47 dl / g (25 ° C, in chloroform)
-Dimethylphenol / 2,3,6-trimethylphenol copolymer (the proportion of 2,3,6-trimethylphenol is 5 mol%) 50 parts, high impact polystyrene (measured with chloroform at 25 ° C as a solvent) Intrinsic viscosity of polystyrene matrix 0.80 dl / g, gel content obtained using benzene as solvent 22.4% by weight) 46 parts, polystyrene-polybutadiene-polystyrene block copolymer (weight ratio of polystyrene part and polybutadiene part is 30 / 70,
And, the viscosity of the 20% toluene solution of the copolymer measured at 25 ° C using a Brukfield model RVT viscometer is 1
500 cps) 3 parts, ethylene-propylene copolymer (concentration 0.1 g / 100 ml using decalin as a solvent, reduced specific viscosity 2.0 measured at a temperature of 135 ° C, glass transition point -49 ° C) 1 part, tetrakis (2,4- Di-tert-butylphenyl) -4,4'-biphenylenediophionite 0.4 part, 2,6-di-tert-butyl-P-cresol 0.3 part, titanium oxide 5 parts, partially oxidized polyethylene wax (SANYO) Kasei: Product name "E-250
p ") and 1.5 parts by weight of triphenyl phosphate (TPP) and the metal salt of phosphoric acid of the reference example shown in Table 1, respectively, with a Labo Plastomill (Toyo Seiki) at a kneading bath temperature of 270
Kneading was carried out under conditions of a temperature of 60 ° C. and a roller rotation speed of 60 rpm. The obtained melt-kneaded product was taken out from Labo Plastomill and pressed at a pressure of 200 kg / cm ² for 10 minutes using a mold at 290 ° C. to prepare a 1/16 ″ -thick sheet. A ″ × 5 ″ strip-shaped test piece was cut out and used for a combustion test according to UL94 standard.

Comparative Examples 1 to 4 In Examples 1 to 3, in place of the combined use of triphenyl phosphate and a metal salt of phosphoric acid, triphenyl phosphate or a metal salt of phosphoric acid alone is used in each of the weights shown in Table 1. The operations of Examples 1 to 3 were repeated except that a part was used. The results are shown in Table 1.

As is clear from the results of Table 1, although a large amount of metal salt of phosphoric acid alone (Comparative Examples 2, 3 and 4) does not have a flame retarding effect, a small amount of metal salt of phosphoric acid produces a small amount of triflate. When used in combination with enyl phosphate, the flame retardant effect is revealed.
Only a small amount of triphenyl phosphate (Comparative Example 1)
No flame retardant effect is observed.

Example 5 The procedure of Example 1 was repeated except that 5.6 parts by weight of A) of Reference Example and 8.4 parts by weight of triphenyl phosphate were used as the metal salt of phosphoric acid in Example 1. The average burning time was 4.9 seconds. By the way, the average burning time when using only 8.4 parts by weight of triphenyl phosphate is
It took 8.5 seconds.

Example 6 The procedure of Example 3 was repeated except that 8.5 parts by weight of D) and 6.0 parts by weight of triphenyl phosphate were used as the metal salt of phosphoric acid in place of C) in Reference Example. The average burning time was 5.8 seconds. On the other hand, when only 12.6 parts by weight of D) of Reference Example was used, drops were generated.

〔The invention's effect〕

The heating weight loss of the metal salt of phosphoric acid, which is a constituent of the resin composition of the present invention, is small, and therefore, volatilization of these metal salts due to heating from the resin composition of the present invention containing this and a small amount of a phosphate compound. The amount is lower than in the case of a resin composition containing a large amount of only the corresponding phosphate compound.
Further, the combined use of a metal salt of phosphoric acid and a phosphate compound imparts an effective flame retarding effect to the polyphenylene ether resin composition.

Claims (3)

[Claims] 1. A polyphenylene ether resin (a) (1)
99 parts by weight, (b) 99 to 1 parts by weight of the vinyl aromatic hydrocarbon resin, and 100 parts by weight of the resin component (c) 1 to 1 of the metal salt of phosphoric acid represented by the following general formula (I)
A flame-retardant polyphenylene ether resin composition comprising 50 parts by weight and (d) 1 to 50 parts by weight of a phosphate compound. M: Ca, Ba or _{Al R 1, R 2, R} 3, R 4: an alkyl group l of _{C 1~3, m, n, o} : 0 or an integer of 1 to 5 p: when M is Ca, Ba, 0 is 1 when M is Al 2. The flame-retardant polyphenylene ether resin composition according to claim 1, wherein the (d) phosphate compound is a phosphate compound represented by the following general formula (IV). (R ₉ , R ₁₀ and R ₁₁ are each independently an alkyl group, a cycloalkyl group, an allyl group, an alkyl-substituted allyl group, an allyl-substituted alkyl group, hydrogen, etc.) 3. The weight ratio of (c) the metal salt of phosphoric acid represented by the general formula (I) and (d) the phosphate compound is from 10/90 to 8.
It is 0/20, The flame-retardant polyphenylene ether-type resin composition of Claim (1) characterized by the above-mentioned.