JP3128909B2 - Flame retardant polyester composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant liquid crystal polyester composition having excellent flame retardancy, particularly excellent granule drop resistance upon burning, and excellent heat resistance with good mechanical properties and appearance of a molded product. About.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for higher performance of plastics, and a number of polymers having various new properties have been developed and marketed. Among them, optics characterized by a parallel arrangement of molecular chains. Anisotropic liquid crystal polymers have attracted attention because of their excellent fluidity and mechanical properties, and their applications are expanding to mechanical parts, electric / electronic parts, and the like. On the other hand, these industrial materials are strongly required to have flame safety, that is, flame retardancy, in addition to the general balance of chemical and physical properties.

In general, it is known that a liquid crystal polymer has a burning resistance and has a property of forming a carbonized layer in a self-foaming manner when directly exposed to a flame. However, a liquid crystal polyester obtained by copolymerizing an acyloxy aromatic carboxylic acid with a polyester obtained from an alkylene glycol and a dicarboxylic acid, which is a typical liquid crystal polymer (for example, a polymer described in JP-B-56-18016), is a thin-walled molded product (1/1). It is known that the flame retardancy at 32 ") is insufficient, and the liquid crystal polyester is flame retarded by using an organic bromine polymer compound and an antimony compound in combination (Japanese Unexamined Patent Publication No.
-118567).

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Laid-Open No. 1-1
For 18 56 The method described in 7 No. is required to be added in a large amount of antimony compound, retention stability during molding was found to be remarkably poor. On the other hand, the present inventor has found that a liquid crystal polyester having a specific structure can be made flame-retardant with only a small amount of an organic bromine polymer compound without using an antimony compound, and the retention stability during molding can be greatly improved. However, the polyester when the dwell long time at 300 ° C. or more high temperature and organic bromine polymer compound is decomposed, it was found that there is a problem that allowed to decompose the liquid crystal polyester. The inventor of the present invention has made intensive studies to solve the above problems, and as a result, has arrived at the present invention.

[0005]

The present invention provides: (B) A brominated police having a heating weight loss temperature of 1% by weight of 315 ° C or more when heated at a rate of 10 ° C / minute under a nitrogen stream with respect to 100 parts by weight of a melt anisotropic polyester.
Styrene 0.5 to 30 parts by weight, (C) a flame retardant polyester composition characterized by comprising the additional inclusion of a filler 0-200 parts by weight. 2. The above (1), wherein the (A) melt-anisotropic polyester contains an ethylenedioxy unit as an essential component.
The flame-retardant polyester composition according to the above. To achieve the purpose.

The term "melt anisotropic polyester" as used in the present invention refers to a polyester having a unit selected from aromatic oxycarboxylate units, aromatic dioxy units, aromatic dicarbonyl units, ethylenedioxy units and the like. It is a polyester exhibiting anisotropy, preferably a polyester selected from the following structural units (I) to (V), and particularly preferably a polyester containing a structural unit (IV).

[0007]

Embedded image (However, X in the formula is

Embedded image Y represents one or more groups selected from

Embedded image And at least one group selected from

The copolymerization amount of the above structural units (I), (II), (III) and (IV) is preferably the following copolymerization amount.

The structural unit (V) is preferably formed from terephthalic acid, and the structural units (II), (III) and (IV)
Substantially equimolar to the sum .

[0010] In the present invention (B) a brominated polystyrene used as the component have a bromine atom in the molecule, those which are used as a passing <br/> normal flame retardants. This bromination
The polystyrene has a 1% by weight heat loss temperature of 315 ° C. or more when heated at a rate of 10 ° C./min under a nitrogen stream, and preferably has a hydrogen bromide generation amount of 325 g / g under a vacuum of 50 mmHg or less. It is 20 μg / g or less at 15 ° C. for 15 minutes. (The amount of hydrogen bromide generated is determined by the
Hydrogen bromide generated by charging 1 g of styrene and sealing at 325 ° C. under a vacuum of 50 mmHg or less was measured using a detector tube or an ion chromatograph. )

[0011]

[0012]

The brominated polystyrene is represented by the following formula (b) having a weight average molecular weight of 1 × 10 ³ to 30 × 10 ⁴ produced by brominating polystyrene obtained by radical polymerization or anion polymerization. Or a polybrominated styrene having a brominated styrene unit represented by the formula (b) or (c) produced by radical polymerization or anionic polymerization of a brominated styrene monomer, preferably by radical polymerization. In particular, polybrominated styrene produced from a brominated styrene monomer and having a structural unit represented by the following formula (c) as a main component is preferable.

[0014]

Embedded image The polybrominated styrene represented by the formula (c) and used in the present invention preferably contains 60% by weight or more of dibrominated styrene units, and more preferably contains 70% by weight or more. In addition to dibrominated styrene monomer, monobrominated styrene and / or tribrominated styrene
It may be a polybrominated styrene copolymerized in an amount of not more than 30% by weight, preferably not more than 30% by weight.

[0015] Mn of the brominated polystyrene is 1 × 10
⁴ to 30 × 10 ⁴ , Mw is 2 × 10 ^{4 to} 120 × 10 ^4
4 , Mn is 1 × 10 ⁴ to 15 × 10 ⁴ , Mw
Is more preferably 2 × 10 ^{4 to} 60 × 10 ⁴ . Also,
The ratio of Mw / Mn is 1. ~ 5.0 is preferred, and 2.0 ~
4.0 is more preferred. If the Mn is less than 1 × 10 ⁴ or the Mw is less than 2 × 10 ⁴ , the mechanical properties and the solder heat resistance at the time of molding stay are greatly reduced, which is not preferable. On the other hand, if greater than Mn of 3 0 × 10 ^4, Mw of 12
When it is larger than 0 × 10 ⁴ , the fluidity of the composition of the present invention becomes poor, which is not preferable.

Further, odor fluorinated polystyrene apparent density 1.0 g / cm ³ or more, preferably stiffer density 1.1 g / cm ³ or more, an apparent density of 1.1 g / cm ³ or more, firm density 1.2 g / cm ³ or more is more preferable. The odor fluorinated poly styrene <br/> This less mean diameter 2.5μ in the molten anisotropic polyester, it preferably dispersed below 2.0Myu. The average molecular weight is a value measured using a gel permeation chromatograph, and is an absolute value based on polystyrene molecular weight.

The amount of the brominated polystyrene is 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight based on 100 parts by weight of the melt anisotropic polyester. . If the amount is less than 0.5 part by weight, the flame-retardant effect is insufficient.
It is not preferable because thermal characteristics are deteriorated. Incidentally, since many hydrogen bromide generation amount at the time of heating of containing a large amount of monomer and 2-3 mers even odor fluorinated polystyrene,
By melt-kneading with a vented extruder to remove the monomer and the dimer or trimer, or by extracting with an organic solvent such as acetone, the monomer and the dimer in the brominated polystyrene are not more than 4% by weight, Preferably, it is necessary to be 1% by weight or less. The brominated polystyrene thus obtained is
The amount of hydrogen bromide generated during extrusion and molding is small, and not only the mechanical properties of the molded product are high, but also the corrosion of the mold and the like can be completely suppressed.

The amount of the filler used as the component (c) in the present invention is 0 to 200 parts by weight based on 100 parts by weight of the melt anisotropic polyester, and is selected from the group consisting of glass fiber, potassium titanate fiber, gypsum fiber, and brass. Fiber, stainless steel fiber, steel fiber, ceramic fiber, boron whisker fiber, mica, talc, calcium calcium carbonate, glass beads, glass flake, glass micro balloon,
Clay, wollastenite, fibrous such as titanium oxide, powdery, granular or plate-like inorganic filler and carbon fiber,
And aromatic aramid fibers.

In the above-mentioned filler, glass fibers are preferably used. The glass fiber can be selected from long fiber type, short fiber type chopped strand, milled fiber, etc., and the average fiber diameter of the glass fiber is to improve the anisotropy of the molded product, the surface appearance, The thickness is preferably 3 to 15 μm from the viewpoint of flame retardancy as well as the point of improving the fire resistance.
11 μm is more preferable, and most preferably 3 to 8 μm.
m. The length of the glass fiber is 30 to 10 ⁴ μm
Is more preferable, and more preferably 1000 to 4000 μm
It is. If the average fiber diameter is larger than 15 μm, the moldability will be reduced, the surface appearance will be poor, and the flame retardancy is not preferred. If the thickness is less than 3 μm, the effect of improving anisotropy is small, which is not preferable.

The amount of the filler to be added is 0 to 200 parts by weight, preferably 1 to 100 parts by weight of the melt anisotropic polyester.
5 to 150 parts by weight. Further, the glass fiber may be coated or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer, a thermosetting resin such as an epoxy resin, or a coupling agent such as a silane-based resin or a titanate-based resin, and other materials. It may be treated with a surface treatment agent.

The structural unit (IV) is composed of the structural units (I), (II) and (II)
When the amount is 0 to 23 mol% with respect to the sum of (I) and (IV) , flame retardancy can be achieved only with the flame retardant of the present invention without adding an antimony compound. Although any method may be used for producing the melt-anisotropic polyester used in the present invention, the following method is mentioned as a typical production method when the structural unit (IV) is contained, and (2) is particularly preferable.

(2) p-hydroxybenzoic acid, 4,4 '
A method of deacetic acid polymerization of an aromatic dihydroxy compound such as dihydroxybiphenyl, an aromatic dicarboxylic acid such as acetic anhydride and terephthalic acid, and a polyester made of an aromatic dicarboxylic acid with ethylene glycol such as polyethylene terephthalate.

The melt anisotropic polyester used in the present invention has a melt viscosity of 50 to 10,000 poise, especially 100.
A range of -5,000 poises is preferred. The melt viscosity was calculated as follows: (liquid crystal onset temperature + 30 ° C and shear rate of 1,000
(1 / sec)) measured by a flow tester. On the other hand, the logarithmic viscosity of this liquid crystal polyester is 0.5 to 15 dl / g, particularly 1.0 g / dl, measured in pentafluorophenol at a concentration of 0.1 g / dl and 60 ° C.
To 10.0 dl / g is preferable, and when including the structural unit (IV), 1.0 to 3.0 dl / g is preferable.

In the polycondensation of the melt anisotropic polyester used in the present invention, in addition to the components constituting the structural units (I) to (V), 2,2'-diphenyldicarboxylic acid, 1,2 Aromatic dicarboxylic acids such as -bis (phenoxy) ethane-4,4'-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid, adipic acid, azelaic acid, sebacic acid , Aliphatic dicarboxylic acids such as dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, methylhydroquinone, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylpropane, 4,4 '-Dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide,
Aromatic diols such as 4,4'-dihydroxybenzophenone and their ethylene oxide adducts, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol,
Aliphatic, alicyclic diols such as 4-cyclohexanedimethanol and m-hydroxybenzoic acid, aromatic hydroxycarboxylic acids such as 2,6-hydroxynaphthoic acid,
p-Aminophenol and the like can be further copolymerized in a small proportion that does not impair the object of the present invention.

The composition of the present invention contains an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphite, phosphonites, and substituted products thereof) to the extent that the object of the present invention is not impaired. UV absorbers (eg, resorcinol, salicylate, benzotriazole, benzophenone, etc.) Lubricants and release agents (eg, montanic acid and its salts, esters, half esters thereof, stearyl alcohol, stearamide, and polyethylene wax) Dyes (eg, niclosin) And colorants, including plastics and pigments (eg, cadmium sulfide, phthalocyanine, carbon black), plasticizers,
Ordinary additives such as an antistatic agent and other thermoplastic resins can be added to impart predetermined characteristics.

The polyester composition of the present invention is preferably melt-kneaded, and a known method can be used for melt-kneading. For example, using a Banbury mixer, rubber rolls, kneader, single screw or twin screw extruder, etc.
The composition can be melt-kneaded at a temperature of 00 to 400 ° C to obtain a composition.

Hereinafter, the present invention will be described in detail with reference to examples. [Reference Example 1] 1,105 parts by weight of p-hydroxybenzoic acid, 140 parts by weight of 4,4'-dihydroxybiphenyl
1,067 parts by weight of acetic anhydride, 125 parts by weight of terephthalic acid and 240 parts by weight of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g were charged into a reaction vessel equipped with a stirring blade and a distillation tube, and then deacetic acid was added under the following conditions. Polycondensation was performed. First, at 100 to 250 ° C. for 5 hours in a nitrogen gas atmosphere,
After reacting at 50 to 315 ° C for 1.5 hours, 315 ° C,
The pressure was reduced to 0.5 mmHg in 1.5 hours, and the reaction was further performed for 1.0 hour to complete the polycondensation. As a result, almost the theoretical amount of acetic acid was distilled out, and a resin (d) having the following theoretical structural formula was obtained. Was.

[0028]

Embedded image k / l / n / m = 80 / 7.5 / 12.5 / 20

Further, as a result of confirming the optical anisotropy by placing the polyester on a sample stage of a deflection microscope and raising the temperature,
The liquid crystal onset temperature was 292 ° C., indicating good optical anisotropy. The logarithmic viscosity of this polyester (0.1 g / dl
In pentafluorophenol at a temperature of 60 ° C)
Is 1.96 dl / g, 322 ° C., shear rate 1,0
The melt viscosity at 00 / sec was 910 poise.

[0030]

Example 1 80% by weight of dibrominated styrene, monobrominated
Contains 15% by weight of styrene and 5% by weight of tribrominated styrene.
A mixture of 500 g of the monomer and 500 g of toluene
Radical polymerization (thermal polymerization, 60-120 ° C, 12:00
After stirring, toluene and unreacted monomers are evaporated under reduced pressure.
Removal by distillation gave brominated polystyrene. This bromine
The polystyrene is further extracted with acetone.
, Number average molecular weight 3 × 10 ⁴ , weight average molecular weight 8 × 10
^{In step 4} , 1 weight when heated at 10 ° C / min under nitrogen stream
% Heat loss temperature 342 ° C, bromine content 59% bromination
Polystyrene (e-1) was obtained. The molten anisotropic polyester 100 parts by weight of the Example 1, the brominated Police
8.0 parts by weight of styrene (e-1) , and an epoxy-based coating agent
Average diameter 6μ treated with epoxy coupling agent
m, glass fiber of average length 3,000 microns (f) (Nippon electric
After 45 parts by weight of ECS03T-187DE manufactured by Gas Glass Co., Ltd. were mixed with a ribbon blender, the mixture was melt-kneaded and pelletized at 310 ° C. using an extruder with a 40 mmφ vent.

Next, the obtained pellets are used in a Sumitomo Nestal injection molding machine Promat 40/25 (Sumitomo Heavy Industries, Ltd.)
335 ° C, mold temperature 90 ° C
Combustion test piece (1/64 "x 1/2" x 5 ")
Test specimens (1/8 "x 1/2" x 5 ") for bending test and deflection temperature under load (HDT) measurement were formed.The appearance of these test pieces was observed, and a vertical combustion test was conducted in accordance with UL94 standard. HD according to ASTM D648
T (18.56 kgf / cm ² ) was measured.

As a result, the brominated polystyrene of the present invention
The polyester composition containing (e-1) has a flame retardancy of 1/64 "V-0, a non-drip, and a bending strength of 1830.
Kgf / cm ² , HDT 257 ° C. It was found that the molded article had excellent mechanical and thermal properties and a good appearance of a molded article. After being retained in the molding machine for 30 minutes, molding was performed and the retention stability was examined.
Kgf / cm ² (retention rate: 98%) was hardly reduced in physical properties, and the color tone (light yellow) of the molded product was hardly changed. Further, the sample was placed 1g of test tube, sealed under a vacuum of 10 mmHg, every 15 minutes at 325 ° C., by measuring the detector tube hydrogen bromide generated, brominated poly
The amount of hydrogen bromide generated from styrene (e-1) was 5 μg / g.

The brominated polystyrene of Example 1 (e-1)
Instead of 1% by weight when heated at a rate of 10 ° C./min. Under a nitrogen stream, a weight loss temperature of 305 ° C. and a bromine content of 62%.
Was added odor fluorinated poly styrene (e-2), was melt-kneaded pelletized flame retardant was molded 1/64 "V-
It was retained in a molding machine for 30 minutes, and retention stability was examined. As a result, the bending strength was 1592 Kgf / cm ² (retention rate: 87%), and the physical properties were significantly reduced. Was also 180 [mu] g / g was measured hydrogen bromide emission from odor fluorinated poly <br/> styrene (e-2).

[0034]

As described above, the present invention provides a flame-retardant polyester composition having excellent flame retardancy, particularly excellent granule falling resistance upon burning, excellent mechanical properties and molded article appearance, and excellent heat resistance. The following are industrially superior effects that can be obtained.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 67/00

Claims (2)

(57) [Claims] 1. A heating weight loss temperature of 1% by weight when (B) a temperature is raised at 10 ° C./min in a nitrogen stream with respect to 100 parts by weight of (A) a melt anisotropic polyester is 315 ° C. or more. Smell
0.5 to 30 parts by weight of polystyrene , (C) filler 0
What is claimed is: 1. A flame-retardant polyester composition characterized by containing about 200 parts by weight. 2. The flame-retardant polyester composition according to claim 1, wherein (A) the melt-anisotropic polyester contains an ethylenedioxy unit as an essential component.