JP3079621B2 - Flame retardant liquid crystal polyester composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a flame-retardant liquid crystal polyester composition having excellent flame retardancy, especially excellent granule drop resistance upon burning, and having excellent mechanical properties and molded article appearance and excellent heat resistance. 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.

[0003] On the other hand, these industrial materials are strongly required to have safety against a flame, 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 combustion 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 (1/32). It is known that flame retardancy in ") is insufficient, and flame retardancy is caused by using an organic bromine compound and an antimony compound in combination with this liquid crystal polyester (Japanese Patent Application Laid-Open No. 1-118567).

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-open No. Hei 1-1185
The method described in Japanese Patent Publication No. 67 requires a large amount of an antimony compound to be added, so that the retention stability during molding was found to be extremely poor. On the other hand, the present inventors have found that a liquid crystal polyester having a specific structure can be made flame-retardant by using only a small amount of an organic bromine compound without using an antimony compound, and the retention stability during molding can be greatly improved.

However, this polyester is 300
It was found that when the resin was kept at a high temperature of not less than ° C for a long time, the organic bromine compound was decomposed and the liquid crystal polyester was also decomposed. Further, it has been found that the flame retardancy of a thin-walled molded product having a thickness of 1/32 "or less is not always sufficient.

[0006]

That is, the present invention relates to (A) 100 parts by weight of a liquid crystal polyester comprising the following structural units (I), (II), (III) and (IV): Compound 0.5 to 30 parts by weight (C) Phenol compound and / or phosphite compound having a molecular weight of 5,000 or more and containing at least one aromatic ring.
An object of the present invention is to provide a flame retardant liquid crystal polyester composition containing 001 to 5 parts by weight.

[0007] In the present invention, the copolymerization ratio of the structural units (I) to (III) (the structural unit (IV) is the same as the structural units (II) and (II)
Is substantially equimolar to the sum of I)) , but the following embodiment is for X of the above structural unit (III)

[0008] In the case of (1), the structural unit (I) is replaced by the structural unit (I), (II)
40 to 90 mol% of (III) and the structural unit (I
The sum of (I) and (III) is the structural unit (I), (I
60 to 10 mol% based on the total of I) and (III)
And the molar ratio of the structural units (II) and (III)
[(I) / (II)] is preferably from 8/2 to 2/8, and more preferably from 7.5 / 2.5 to 2.5 / 7.5.
On the other hand, when X of the structural unit (III) is —CH ₂ CH ₂ —, the preferred composition of the structural units (I) to (IV) is such that the total of the structural units (I) and (II) is the structural unit (I); (I
75 to 95 mol% based on the total of I) and (III), wherein the structural unit (III) is composed of the structural units (I), (II) and
25 to 5 mol%, preferably 20 to 70 mol%, more preferably 15 to 10 mol%, based on the total of (III) and (III), and the molar ratio of the structural units (I) and (II) [(I)
/ (II)] is 75/25 to 95/5, preferably 78.
/ 22 to 93/7, more preferably 91/9 to 93/7
It is. Further, Y of the structural unit (IV) is

[0009] Is most preferred. In the polycondensation of the aromatic polyester of the present invention, the above structural units (I) to (IV)
3,3'-diphenyldicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 2,2'-diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid Acid, aromatic dicarboxylic acid such as 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid, alicyclic dicarboxylic acid such as hexahydroterephthalic acid, bisphenol A, bisphenol S, resorcinol, chlor Aromatic dihydroxy compounds such as hydroquinone, methylhydroquinone and 2,6-dihydroxynaphthalene, and their ethylene oxide adducts, and aromatics such as β-hydroxyethoxybenzoic acid, m-oxybenzoic acid and 2,6-oxynaphthoic acid Oxycarboxylic acid and p-aminophenol, p-aminobenzoic acid, etc. do not impair the purpose of the present invention. It can be allowed to further copolymerization in a range of minor proportions of degree.

The liquid crystal polyester of the present invention (A)
Can measure the logarithmic viscosity in pentafluorophenol, at a concentration of 0.1 g / dl at 60 ° C.
In is preferably not less than 0.5 dl / g as measured values, in particular X is -CH ₂ CH ₂ in the structural unit (III) - For 1.0～3.0Dl /
g is preferably, X of the structural unit (III) is -CH ₂ CH ₂ - if that does not include the preferred 2.0~10.0dl / g.

The melt viscosity of the aromatic polyester of the present invention is preferably from 10 to 20,000 poise, and more preferably from 20 to 10,000 poise. The melt viscosity is a value measured by a Koka type flow tester under the condition of (liquid crystal onset temperature + 40 ° C) and a shear rate of 1,000 (1 / second). The method for producing the liquid crystal polyester (A) in the present invention is not particularly limited and can be produced according to a known polyester polycondensation method, but X in the structural unit (III) does not contain -CH ₂ CH _2-.
In the case of R>, the following production method (1) is preferable, and in the case of containing -CH ₂ CH _2- , the following production method (2) is preferable.

(1) p-hydroxybenzoic acid, 4,4'-
A method of reacting an aromatic dihydroxy compound such as dihydroxybiphenyl and t-butylhydroquinone, or an aromatic dicarboxylic acid such as terephthalic acid with acetic anhydride to acylate a phenolic hydroxyl group, followed by a deacetic acid polycondensation reaction. (2) In the presence of a polyester or oligomer composed of ethylene glycol and an aromatic dicarboxylic acid such as terephthalic acid, or bis (β-hydroxyethyl) ester of an aromatic dicarboxylic acid such as terephthalic acid
A method of manufacturing according to the method (1).

The organic bromine compound used as the component (B) in the present invention has a bromine atom in the molecule and means a known organic bromine compound which is usually used as a flame retardant. Those having 20% by weight or more are preferred. Specifically, hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis (pentabromophenoxy) ethane, ethylenebis- (tetra Bromophthalimide), low-molecular-weight organic bromine compounds such as tetrabromobisphenol A, brominated polycarbonate (for example, a polycarbonate oligomer produced from brominated bisphenol A or a copolymer thereof with bisphenol A), a brominated epoxy compound (for example, Diepoxy compounds produced by the reaction of brominated bisphenol A with epichlorohydrin and the reaction of brominated phenols with epichlorohydrin Is mono-epoxy compounds), poly (brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A,
Condensates of cyanuric chloride and brominated phenol, halogenated polymers and oligomers such as brominated polystyrene, cross-linked brominated polystyrene, cross-linked brominated poly α-methylstyrene, and mixtures thereof, among which ethylene bis- (Tetrabromophthalimide), brominated epoxy oligomers or polymers, brominated polystyrene, cross-linked brominated polystyrene, brominated polyphenylene ether and brominated polycarbonate are preferred,
Particularly, ethylene bis- (tetrabromophthalimide), brominated polystyrene, and brominated polycarbonate can be particularly preferably used.

The preferred organic bromine compound will be described in more detail. As the brominated epoxy polymer, a compound represented by the following general formula (a) is preferred.

[0015] The polymerization degree n in the general formula (a) is preferably 15 or more, more preferably 50 to 80. Further, as the brominated polystyrene, those 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 The brominated styrene monomer includes a polybrominated styrene having a brominated styrene unit represented by the formula (c) produced by radical polymerization or anionic polymerization, preferably radical polymerization, and particularly, produced from brominated styrene monomer. following
(c) Polybrominated styrene having a polymerization average molecular weight of 1 × 10 ³ to 30 × 10 ⁴ containing a structural unit represented by the formula as a main component is preferable.

[0016] The brominated styrene monomer here is styrene monomer 1
Preferably, each aromatic ring has about two bromine atoms introduced into the aromatic ring by a substitution reaction, and may contain monobrominated styrene, tribrominated styrene and the like in addition to dibrominated styrene.

The polybrominated styrene preferably contains at least 60% by weight of dibrominated styrene units.
More preferably, the content is not less than 10% by weight. In addition to dibrominated styrene, polybrominated styrene obtained by copolymerizing monobrominated styrene and / or tribrominated styrene to 40% by weight or less, preferably 30% by weight or less may be used. The weight average molecular weight of this polybrominated styrene is from 1 × 10 ⁴ to 15 × 10
⁴ is more preferred. If the weight-average molecular weight is less than 1 × 10 ³ , the mechanical properties at the time of molding stay and the decrease in solder heat resistance are large, and if it is more than 30 × 10 ⁴ , the fluidity of the composition of the present invention tends to be poor. There is. The weight average molecular weight is a value measured using a gel permeation chromatograph, and is a relative value based on polystyrene molecular weight.

Further, as the cross-linked brominated polystyrene,
Polystyrene obtained by brominating porous polystyrene cross-linked with divinylbenzene is preferred. As the brominated polycarbonate, those represented by the following general formula (d) are preferable.

[0019] (R ¹ and R ^{2 each} represent a substituted or unsubstituted aryl group, and most preferably a pt-butylphenyl group.) In the above formula (d), the polymerization degree n is preferably 4 or more, and 8 or more. , Especially 8 to 25 can be more preferably used.

The amount of the organic bromine compound (B) to be added is 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the liquid crystal polyester. On the other hand, in the phenol compound and / or phosphite compound having a molecular weight of 5,000 or more and containing at least one aromatic ring used as the component (C) in the present invention, the molecular weight can be obtained by using either the phenol compound or the phosphite compound. 5
It is important that the number is at least 00, preferably 550 to 5,000, and contains at least one aromatic ring.

When a compound having a molecular weight of less than 500 or a compound containing no aromatic ring is used, the effect of improving the retention stability during molding is small, and it is difficult to solve the problems of the present invention. Examples of the phenol compound having a molecular weight of 5,000 or more and containing at least one aromatic ring include:

[0022] (Wherein R is an alkyl group having 1 to 10 carbon atoms such as methyl, ethyl, propyl, tert-butyl and the like). Specific examples include the following: Is mentioned. Triethylene glycol-bis-
3- (3'-t-butyl-4'-hydroxy-5'-methylphenyl) propionate, 1,3,5-tris (3 ', 5'-di-t-butyl-4'-hydroxybenzoyl) isocyanate Nurate, 1,3,5-trimethyl-2,4,6-tris (3 ′, 5 ′
-Di-t-butyl-4'-hydroxy-benzyl) benzene, hexamethylene glycol bis [β- (3,5-di-
t-butyl-4-hydroxy-phenyl) propionate], 6- (4'-hydroxy-3 ', 5'-di-t-butylanilino) -2,4-bis-octyl-thio-1,3,5- Triazine, tetrakis [methylene-3 (3 ', 5'-di-t
-Butyl-4'-hydroxy-phenyl) propionate] methane, 2,2'-thio [diethyl-bis-3 (3 ',
5'-di-tbutyl-4'-hydroxyphenyl) propionate], n-octadecyl-3- (4'-hydroxy-
3 ', 5'-di-t-butylphenol) propionate,
N, N'-hexamethylene-bis-3- (3 ', 5'-di-t
-Butyl-4'-hydroxy-propamide), 1,3,5-tris (3 ', 5'-di-t-butyl-4'-hydroxybenzyl) isocyanurate, 3,5-di-t-butyl- 4-hydroxy-benzylphosphonic acid dimethyl ester, nickel salt of bis (3,5-di-t-butyl-4-hydroxybenzylphosphonic acid) monomethyl ester, and the like, and n-octadecyl-3- (4 ′
-Hydroxy-3 ', 5'-di-t-butylphenol) propionate, tetrakis [methylene-3 (3', 5'-di-t-butyl-4'-hydroxy-phenyl) propionate] methane, triethylene glycol Bis-3- (
3'-t-butyl-4'-hydroxy-5-methylphenyl) propionate and the like can be preferably used. These may be used alone or in combination of two or more.

The phosphite compounds having a molecular weight of at least 500 and containing at least one aromatic ring include tris (noylphenyl) phosphite and tetra (tridecyl)-
4,4'-isopropylidene diphenyl phosphite,
2,2'-methylene-bis (4,6-di-t-butylphenyl) n-octyl phosphite, bis (2,4-di-t-
Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, tetraphenyl-dipropylene glycol diphosphite Phosphite, 4,4'-butylidene-bis (3-methyl-6-t-
Butylphenyl-di-trigesyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and a compound of the following formula (f)

[0024] And 2,2'-methylene-bis (4,6-di-t
-Butylphenyl) n-octyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6 -Di-t-butyl-4
-Methylphenyl) pentaerythritol diphosphite and the like can be preferably used.

The above-mentioned phenol compounds and / or phosphite compounds having a molecular weight of at least 500 and containing at least one aromatic ring can be used alone or in combination, and are more preferably used in combination. The addition amount is 0.001 to 5 parts by weight based on 100 parts by weight of the aromatic polyester.
Preferably it is 0.05 to 3 parts by weight. If the amount is less than 0.001 part by weight, the effect of improving heat resistance cannot be obtained, and if it exceeds 5 parts by weight, the mechanical properties of the liquid crystal polyester tend to be impaired, which is not preferred.

In the flame-retardant liquid crystal polyester composition of the present invention, 100 parts by weight of the liquid crystal polyester (A) is used.
By adding 0.01 to 20 parts by weight of an epoxy compound containing no bromine, the heat resistance during molding stay can be further improved. In this case, the epoxy group is 0.001 to 0.01 g
More preferably, it is added so as to be contained in an equivalent amount. Examples of the epoxy compound include glycidyl ethers such as bisphenol A diglycidyl, orthophenylphenol glycidyl ether, bisphenol A type epoxy compounds represented by the following structural formula (g), hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, and the like. Glycidyl esters of the following structural formula
(h) glycidyl ether esters, epoxy group-containing copolymers such as ethylene / glycidyl methacrylate / vinyl acetate copolymers containing 1 to 30% by weight of glycidyl methacrylate; Epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like. Among these, epoxysilanes Is most preferred.

[0027] (Ar is 1,4-phenylene, 1,3-phenylene, 2,6-phenylene
It represents naphthylene or the like, and n is 0-20. ) The liquid crystal polyester composition of the present invention thus formed exhibits excellent flame retardancy and heat resistance, and the injection molded product is VO even at a thickness of 1/32 "or less according to the UL94 standard vertical combustion test CASTM D790 standard). can do.

In the present invention, it is preferable to add 15 to 150 parts by weight of a filler to the liquid crystal polyester composition. Examples of the filler include glass fiber, carbon fiber, and the like.
Aromatic polyamide fiber, potassium titanate fiber, gypsum fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber, boron whisker fiber, mica, talc,
Examples include fibrous, powdery, granular or plate-like inorganic fillers such as silica, calcium carbonate, glass beads, glass flakes, glass microballoons, clay, wollastenite, and titanium oxide.

In the above-mentioned filler, glass fibers are preferably used. The type of the glass fiber is not particularly limited as long as it is generally used for reinforcing a resin. For example, a chopped strand of a long fiber type or a single fiber type, a milled fiber, or the like can be used. 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 or titanate, or other It may be treated with a surface treatment agent.

In the composition of the present invention, other antioxidants and heat stabilizers, ultraviolet absorbers (for example, resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants, etc., to the extent that the object of the present invention is not impaired. And coloring including mold release agents (such as montanic acid and its salts, esters, half esters, stearin alcohol, stearamide and polyethylene wax), dyes (such as nitrosine) and pigments (such as cadmium sulfide, phthalocyanine, carbon black) Ordinary additives such as additives, plasticizers and antistatic agents and other thermoplastic resins can be added to impart predetermined characteristics.

The resin 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 roll machine, kneader, single-screw or twin-screw extruder, 200-35
The composition can be obtained by melt-kneading at a temperature of 0 ° C.

[0032]

The present invention will be further described below with reference to examples. Example 1. Tribrominated polystyrene "Pyrocheck" 68PB per 100 parts by weight of polymer (A-1) (Nissan Ferro Co., Ltd.)
(B-1), 6 parts by weight of phosphite compound (C-1), 0.1 part by weight of phenol compound (D-1) and 45 parts by weight of glass fiber (chopped strand 3 mm length) after dry blending And a 30 mmφ twin screw extruder at 310 ° C. for melt kneading and pelletizing.

Next, the obtained pellets are subjected to Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.).
Combustion test specimens (1/32 "x 1/2" x 5 ") at a cylinder temperature of 320 ° C and a mold temperature of 90 ° C, test specimens for bending test and deflection temperature under load (DTUL) (1/1) 8 "x 1
/ 2 "x 5"). The appearance of these test pieces was observed, and a vertical combustion test was performed according to UL94 standard, and a DTUL (18.56 kgf / cm ² ) was measured according to ASTM D648.

As a result, the polyester containing the organic bromine compound of the present invention has a flame retardancy of 1/32 "V-0, a bending strength of 1845 kgf / cm ² , DTUL of 257 ° C., and a mechanical and thermal property. It was found to be excellent and had a good appearance of the formed product, and after having been retained in a molding machine for 30 minutes, molding was performed and the retention stability was examined.
The flexural strength was 1812 kgf / cm ² (retention rate 98 %), indicating that there was almost no decrease in physical properties.

[0035] Example 2 The same kneading and pelletizing as in Example 1 was carried out using (C-2) having the following structure in place of the phosphite (C-1) of Example 1, and then molded to have a flame retardancy of 1/32 ″. VO was confirmed, and the sample was kept in a molding machine for 30 minutes to check the retention stability, and the bending strength was 1717 kgf / cm.
² (97% retention), indicating that there was almost no decrease in physical properties.

[0036] Example 3. 100 parts by weight of polymer (A-1), 10 parts by weight of polydibrominated styrene (bromine content: 59%) obtained by polymerizing dibrominated styrene monomer (B-2), phosphite compound (C-
3) After dry blending with 0.2 part by weight and 45 parts by weight of glass fiber (chopped strand 3 mm long), the mixture was melt-kneaded and pelletized at 310 ° C. with a 30 mmφ twin screw extruder.

The obtained pellets were supplied to Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.).
Test pieces similar to those in Examples 1 and 2 were molded under the conditions of a cylinder temperature of 320 ° C. and a mold temperature of 90 ° C. As a result, the flame retardancy
0.5mm thickness, VO and bending strength of 1850kgf / c
m ² , DTUL 258 ° C. Then, after being kept in the molding machine for 30 minutes, molding was performed and the retention stability was examined. As a result, it was found that the bending strength was 1832 kgf / cm ² (retention rate: 99%) and there was almost no deterioration in physical properties.

Further, the bending test piece is connected to a solderability tester.
(Tabai Seisakusho), and immersed for 10 seconds. The appearance was observed, and the temperature at which deformation and swelling did not occur was measured as the solder heat resistant temperature. As a result, the solder heat resistance is still 300 after 30 minutes
° C and the same as before retention. Also, the flame retardancy is V-
O was retained.

[0039] Comparative Example 1. After being melt-kneaded and pelletized without adding (C-1) and (D-1) of Example 1, molding was carried out. When the sample was retained in the machine for 30 minutes and the retention stability was examined, the bending strength was 1592 kgf / cm ²
(Retention rate 87%) and solder heat resistance from 290 ℃ to 250
℃. Comparative Example 2. Melt kneading and pelletizing without adding (C-3) of Example 3 followed by molding resulted in a 0.5 mm thickness and flame retardancy of V-2.

The contents of Examples 1 to 3 and Comparative Examples 1 and 2
The results are shown in Table 1 below .

[Table 1]

According to the flame-retardant liquid crystal polyester composition of the present invention, an injection-molded article excellent in flame retardancy, mechanical properties and retention stability can be obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 69:00) (72) Inventor Norio Kitajima 1-9-9 Oe-cho, Minato-ku, Nagoya-shi, Aichi Nagoya Office of Toray Industries, Inc. (56 References JP-A-2-51524 (JP, A) JP-A-1-174524 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 67/00-67/04

Claims (2)

(57) [Claims] (A) 100 parts by weight of a liquid crystalline polyester comprising the following structural units (I), (II), (III) and (IV): (B) 0.5 to 30 parts by weight of an organic bromine compound ( C) A flame-retardant liquid crystal polyester composition containing 0.001 to 5 parts by weight of a phenol compound and / or a phosphite compound having a molecular weight of at least 500 and containing at least one aromatic ring. 2. Structural unit (III) of liquid crystal polyester
X is -CH₂CH₂−, YAnd the structural unitPosition (I)and(II)Is the structural unit
Rank(I), (II)and(III)Against the sum of7
5-95 mol%, structural unit (III)Structural unit
(I), (II)and25 to 5 mol% of (III)
Yes, structural unit (I)When(II) molar ratio[(I) /
(II)]Is 75/25 to 95/5.
Flame retardant liquid crystal polyestersetAdult.