JP3399120B2 - Liquid crystal polyester resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal polyester resin composition which can be used for molded articles by injection molding or extrusion molding.

[0002]

2. Description of the Related Art Liquid crystal polyesters, unlike crystalline polyesters such as polyethylene terephthalate and polybutylene terephthalate, do not cause entanglement even in a molten state because they have rigid molecules, form a polydomain having a liquid crystal state, and have low shear. It exhibits a behavior in which molecular chains are significantly oriented in the flow direction, and is generally called a melt-type liquid crystal (thermotropic liquid crystal) polymer. Due to this peculiar behavior, the melt fluidity is extremely excellent, a thin-walled molded product of about 0.2 to 0.5 mm can be easily obtained, and the molded product has high strength and high rigidity. Have However, there is a drawback that the anisotropy is extremely large. In order to improve the anisotropy, a filler such as glass fiber has been blended with the liquid crystal polyester, but the heat resistance,
It has not been possible to satisfy the market demand for a resin having rigidity and having excellent tensile properties and impact resistance. Another problem is that liquid crystal polyesters are generally expensive.

There has been a strong demand in the market for a liquid crystal polyester resin composition which retains the excellent heat resistance and mechanical properties of liquid crystal polyester, improves the anisotropy of molded articles, and is inexpensive. Japanese Patent Application Laid-Open No. 56-115357 discloses a resin composition containing a melt-processable polymer and an anisotropic melt-forming polymer. An anisotropic melt-forming polymer is formed in the melt-processable polymer. It is described that the processability of melt-fabricable polymers can be improved by adding a water-soluble polymer. For example, an example in which a liquid crystal polyester is added to a polyphenylene ether / polystyrene mixture is mentioned. JP-A-2-97555 discloses a resin composition in which various polyarylene oxides are mixed with liquid crystal polyester for the purpose of improving solder heat resistance. However, in general, a composition obtained by blending a liquid crystal polyester having a high molding temperature with an amorphous polymer having a lower molding temperature such as polyphenylene ether has a high melting temperature even if the melt processability of the composition is improved. There is a problem that the appearance of the molded product is deteriorated due to thermal decomposition of the compounded resin during the molding process. There is also a problem that the heat resistance, mechanical properties, impact resistance, etc. of the composition are insufficient. Further, compositions such as liquid crystal polyester and aromatic polycarbonate are disclosed in JP-A-57-40551 and JP-A-2-102257. However, they are not sufficient in heat resistance and mechanical properties. There wasn't. USP5216
No. 073 discloses a blend prepared by blending an epoxidized rubber with a liquid crystal polymer, but their heat resistance and mechanical properties were not sufficient.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal polyester resin composition which retains excellent heat resistance and mechanical properties of liquid crystal polyester, has improved tensile strength and weld strength, and is inexpensive. Especially.

[0005]

The present inventors have arrived at the present invention as a result of intensive studies to solve these problems. That is, the present invention comprises the inventions described below. [1] (A) liquid crystal polyester, and (B) (a) ethylene unit of 50 to 99% by weight, (b) unsaturated carboxylic acid glycidyl ester unit or unsaturated glycidyl ether unit of 0.1 to 30% by weight, (C) Epoxy group-containing ethylene copolymer comprising 0 to 50% by weight of ethylenically unsaturated ester compound unit and (C) number average fiber diameter of 5 to 25 μm, number average fiber length of 30 to 1000 μm, and number average The long / number average fiber diameter is 2 to 150, the surface-untreated glass fiber is contained, and the ratio of the component (A) and the component (B) is 55.0 to 99.9% by weight of the component (A). The component (B) is 45.0 to 0.1% by weight, and the weight sum of the components (A) and (B) is 50 to 99% by weight, and the component (C) is 50 to 1% by weight. Liquid crystal polyester resin composition. [2] The liquid crystal polyester resin composition according to [1], wherein the liquid crystal polyester (A) is obtained by reacting an aromatic dicarboxylic acid, an aromatic diol, and an aromatic hydroxycarboxylic acid. [3] The liquid crystal polyester resin composition according to [1], wherein the liquid crystal polyester (A) is obtained by reacting a combination of different aromatic hydroxycarboxylic acids. [4] The liquid crystal polyester resin composition according to [1], wherein the liquid crystal polyester (A) is composed of the following repeating units.

[Chemical 3] [5] The liquid crystal polyester resin composition as described in [1], wherein the liquid crystal polyester (A) is composed of the following repeating units.

[Chemical 4]

Next, the present invention will be described in detail. The liquid crystal polyester as the component (A) of the liquid crystal polyester resin composition of the present invention is a polyester called a thermotropic liquid crystal polymer. Specifically, (1) a combination of an aromatic dicarboxylic acid, an aromatic diol and an aromatic hydroxycarboxylic acid, (2) a combination of different aromatic hydroxycarboxylic acids, (3) an aromatic Examples include a combination of a dicarboxylic acid and a nuclear-substituted aromatic diol, (4) a polyester obtained by reacting a polyester such as polyethylene terephthalate with an aromatic hydroxycarboxylic acid, and the like. Anisotropy at a temperature of 400 ° C. or lower. It forms a melt. Incidentally, instead of these aromatic dicarboxylic acids, aromatic diols and aromatic hydroxycarboxylic acids, ester-forming derivatives thereof may be used. Examples of the repeating structural unit of the liquid crystal polyester include the following, but are not limited thereto. Repeating structural unit derived from aromatic dicarboxylic acid:

[0007]

[Chemical 5]

[0008]

[Chemical 6] Repeating structural units derived from aromatic diols:

[0009]

[Chemical 7]

[0010]

[Chemical 8] Repeating structural unit derived from aromatic hydroxycarboxylic acid:

[0011]

[Chemical 9] Especially preferred liquid crystal polyester from the balance of heat resistance, mechanical properties and processability

[0012]

[Chemical 10] The following combinations (I) to (V) of the repeating structural units are specifically included.

[0013]

[Chemical 11]

[0014]

[Chemical 12]

[0015]

[Chemical 13]

[0016]

[Chemical 14]

[0017]

[Chemical 15] The liquid crystal polyesters (I), (II), (III),
Regarding (IV), for example, Japanese Patent Publication No. 47-4
No. 7870, Japanese Patent Publication No. 63-3888, Japanese Patent Publication No. 63-3891, Japanese Patent Publication No. 56-18016. Among these, the combination of (I) and (II) is more preferable.

In the liquid crystal polyester resin composition of the present invention, in the field where high heat resistance is required, the liquid crystal polyester of the component (A) has the following repeating unit (a ') of 30:
A liquid crystal polyester having a repeating unit (b ') of 0 to 10 mol%, a repeating unit (c') of 10 to 25 mol% and a repeating unit (d ') of 10 to 35 mol% is preferably used. To be done.

[0019]

[Chemical 16] (In the formula, Ar is a divalent aromatic group.)

The epoxy group-containing ethylene copolymer which is the component (B) of the liquid crystal polyester resin composition of the present invention is
(A) 50 to 99% by weight of ethylene units, (b) 0.1 to 30% by weight of unsaturated carboxylic acid glycidyl ester units or unsaturated glycidyl ether units, preferably 0.1.
The epoxy group-containing ethylene copolymer comprises 5 to 20% by weight and (c) an ethylenically unsaturated ester compound unit of 0 to 50% by weight. The compounds which give the unsaturated carboxylic acid glycidyl ester unit and the unsaturated glycidyl ether unit (b) in the epoxy group-containing ethylene copolymer (B) are represented by the following general formulas 17 and 18, respectively.

[0021]

[Chemical 17] (R is a C2-C13 hydrocarbon group having an ethylenically unsaturated bond.)

[Chemical 18] (R is a hydrocarbon group having an ethylenically unsaturated bond and having 2 to 13 carbon atoms, and X is -CH ₂ -O- or

[Chemical 19] Is. ) Specific examples include glycidyl acrylate, glycidyl methacrylate, itaconic acid glycidyl ester, allyl glycidyl ether, 2-methylallyl glycidyl ether, and styrene-p-glycidyl ether.

The epoxy group-containing ethylene copolymer of the present invention includes a terpolymer of carboxylic acid glycidyl ester or unsaturated glycidyl ether, ethylene and (c) an ethylenic unsaturated ester compound, which is a ternary or more terpolymer. Can also be used. Examples of the ethylenically unsaturated ester compound (c) include vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, carboxylic acid vinyl esters such as butyl methacrylate, Examples include α, β-unsaturated carboxylic acid alkyl esters and the like. Particularly, vinyl acetate, methyl acrylate, and ethyl acrylate are preferable.

The epoxy group-containing ethylene copolymer (B) used in the present invention includes, for example, a copolymer consisting of ethylene units and glycidyl methacrylate units, a copolymer consisting of ethylene units, glycidyl methacrylate units and methyl acrylate units, Examples thereof include copolymers composed of ethylene units, glycidyl methacrylate units and ethyl acrylate units, copolymers composed of ethylene units, glycidyl methacrylate units and vinyl acetate units.

The melt index of the epoxy group-containing ethylene copolymer (hereinafter sometimes referred to as MFR, JIS K6760, 190 ° C., 2.16 kg load) is preferably 0.5 to 100 g / 10 minutes, and further, It is preferably 2 to 50 g / 10 minutes. The melt index may be out of this range, but if the melt index exceeds 100 g / 10 min, it is not preferable in terms of mechanical properties when the composition is formed, and if it is less than 0.5 g / 10 min, the component (A) is Is inferior in compatibility with the liquid crystal polyester and is not preferable.

The epoxy group-containing ethylene copolymer is usually an unsaturated epoxy compound and ethylene in the presence of a radical generator at 500 to 4000 at 100 to 300 ° C. in the presence or absence of a suitable solvent or chain transfer agent. It is produced by a method of copolymerizing below. It can also be produced by a method of mixing an unsaturated epoxy compound and a radical generator with polyethylene and performing melt graft copolymerization in an extruder.

The glass fiber of the component (C) of the liquid crystal polyester resin composition of the present invention has a number average fiber diameter of 5 to 25 μm.
m, preferably 5 to 20 μm, and the number average fiber length is 30 to 1
000 μm, preferably 30 to 300 μm is used. If the number average fiber diameter or the number average fiber length is out of this range, the reinforcing effect of the glass fibers becomes small, and sufficient rigidity, dimensional stability, and processability cannot be obtained, which is not preferable.

Further, the morphological ratio (hereinafter sometimes referred to as aspect ratio) represented by the number average fiber length / number average fiber diameter of glass fibers, that is, the ratio of the number average fiber length and the number average fiber diameter of glass fibers is , 2 to 150, preferably 3 to 20 are used. If the aspect ratio is out of this range, the appearance of the molded article of the composition is poor and the molding processability is unfavorable.

The glass fiber of the component (C) in the present invention has no surface treatment. The use of other glass fibers is not preferable because the mechanical properties and heat resistance of the composition deteriorate.

In the liquid crystal polyester resin composition of the present invention, when the composition ratio of the component (A), the component (B) and the component (C) takes a value within a specific range, the desired thermoplastic resin composition is obtained. You can get things. The composition ratio of the component (A) and the component (B) in the present invention is 55.0 to 99.9% by weight of the component (A) and 45.0 to the component (B).
0.1% by weight, preferably 65.0% of component (A)
˜99.0% by weight, and the component (B) is 35.0 to 1.0% by weight. When the component (A) is less than 55.0% by weight,
The heat resistance and mechanical properties of the molded product made of the composition are insufficient, and when it exceeds 99.9% by weight, the effect of improving the anisotropy of the composition becomes insufficient, and the advantage is low in cost. Not preferable.

In the present invention, the total weight of the component (A) and the component (B) is 50 to 99% by weight, while the component (C) is 50 to 1% by weight.
% By weight. When the content of the component (C) is less than 1% by weight, the effect of improving the mechanical strength and dimensional stability of the liquid crystal polyester resin composition of the present invention is small, and the content of the component (C) is 5
If it exceeds 0% by weight, the molding processability of the composition is deteriorated, and the appearance of the injection-molded article is also unfavorable.

The method for producing the liquid crystal polyester resin composition of the present invention is not particularly limited, and known methods can be used. For example, a method of mixing the components in a solution state and evaporating the solvent, a method of precipitating in the solvent, or a method of kneading the components in a molten state can be mentioned. From an industrial point of view, a method of kneading each component in a molten state is preferable. For melt kneading, generally used kneading devices such as a single-screw or twin-screw extruder and various kneaders can be used. A biaxial high kneader is particularly preferable. When melt-kneading, the cylinder setting temperature of the kneading device is 200-
It is preferably in the range of 360 ° C, more preferably 230 to
It is 350 ° C.

Upon kneading, the respective components may be mixed in advance by a device such as a tumbler or a Henschel mixer, or if necessary, the mixing may be omitted and the respective amounts may be separately supplied to the kneading device. Methods can also be used.

The kneaded resin composition is molded by various molding methods such as injection molding, extrusion molding and the like, but it is melt-processed by dry blending during injection molding or extrusion molding without undergoing the kneading process in advance. It is also possible to directly knead into the resin composition of the present invention to obtain a molded product.

In the liquid crystal polyester resin composition of the present invention, an inorganic filler is optionally used. Such inorganic fillers include calcium carbonate, talc, clay, silica, magnesium carbonate, barium sulfate, titanium oxide, alumina, gypsum, glass flakes, carbon fibers, alumina fibers, silica-alumina fibers, aluminum borate whiskers, titanium. Examples thereof include potassium acid fiber.

In the liquid crystal polyester resin composition of the present invention,
If necessary, further, an organic filler, an antioxidant, a heat stabilizer, a light stabilizer, a flame retardant, a lubricant, an antistatic agent, an inorganic or organic colorant, a rust preventive agent, a crosslinking agent, a foaming agent, a fluorescent agent. Various additives such as an agent, a surface smoothing agent, a surface gloss improving agent, and a release improving agent such as a fluororesin can be added during the manufacturing process or in the subsequent processing process.

[0036]

EXAMPLES The present invention will be described below with reference to examples, but these are merely examples and the present invention is not limited to these.

(1) Liquid crystalline polyester (i) of component (A) p-acetoxybenzoic acid 10.8 kg (60 mol), terephthalic acid 2.49 kg (15 mol), isophthalic acid 0.83 kg (5 mol) and 4 5.45 kg (20.2 mol) of 4,4'-diacetoxydiphenyl was charged into a polymerization tank having a comb-shaped stirring blade, and the temperature was raised with stirring under a nitrogen gas atmosphere to carry out polymerization at 330 ° C. for 1 hour. Polymerization was performed under strong stirring while removing acetic acid by-produced during this period. Then, the system was gradually cooled, and the polymer obtained at 200 ° C. was taken out of the system. The obtained polymer was pulverized with a hammer mill manufactured by Hosokawa Micron Co., Ltd.
The following particles were used. This was further treated in a rotary kiln under a nitrogen gas atmosphere at 280 ° C. for 3 hours to obtain a particulate wholly aromatic polyester having a repeating temperature of 324 ° C. and consisting of the following repeating structural units. Hereinafter, the liquid crystal polyester is abbreviated as A-1. This polymer exhibited optical anisotropy at 340 ° C. or higher under pressure. The repeating structural unit of the liquid crystal polyester A-1 is as follows.

[0038]

[Chemical 20]

(Ii) p-hydroxybenzoic acid 16.6
kg (12.1 mol) and 6-hydroxy-2-naphthoic acid 8.4 kg (4.5 mol) and acetic anhydride 18.6 k
g (18.2 mol) was charged into a polymerization tank equipped with a comb-type stirring blade, and the temperature was raised with stirring under a nitrogen gas atmosphere to 320 ° C.
For 1 hour and then under a reduced pressure of 2.0 torr for 32
Polymerization was carried out at 0 ° C for 1 hour. During this period, acetic acid produced as a by-product was continuously distilled out of the system. After that, the system is gradually cooled to 180
The polymer obtained at ℃ was taken out of the system. The obtained polymer was pulverized in the same manner as in the above (i), and then treated in a rotary kiln under a nitrogen gas atmosphere at 240 ° C. for 5 hours to obtain the following repeating units in the form of particles having a flow temperature of 270 ° C. A wholly aromatic polyester was obtained. Hereinafter, the liquid crystal polyester is abbreviated as A-2. This polymer exhibited optical anisotropy at 280 ° C. or higher under pressure. The ratio of the repeating structural units of the liquid crystal polyester A-2 is as follows.

[0040]

[Chemical 21]

(2) Component (B) Epoxy Group-Containing Ethylene Copolymer The copolymer used as component (B) is as follows. BB-1 (abbreviation): Sumitomo Chemical Co., Ltd., trade name Bond First 7M, composition ethylene / glycidyl methacrylate / methyl acrylate = 64/6/30, MFR (190 ° C., 2.16 kg load) = 9 g / 10
Minutes. BB-2 (abbreviation): Sumitomo Chemical Co., Ltd., trade name Bond First 2B, composition: ethylene / glycidyl methacrylate / vinyl acetate = 83/12/5, MFR (190 ° C., 2.16 kg load) = 3 g / 10
Minutes.

(3) The glass fibers used as the component (C) are as follows. C-1 (abbreviation): Central Glass Co., Ltd., trade name EF
H75-01, number average fiber diameter 13 μm, number average fiber length 5
0 μm, aspect ratio 3.8, no surface treatment. C-2 (abbreviation): Nippon Sheet Glass Co., Ltd., trade name REV
8. Number average fiber diameter 13 μm, number average fiber length 70 μm, aspect ratio 5.4, aminosilane treatment. C-3 (abbreviation): Nippon Sheet Glass Co., Ltd., trade name RES0
3-TP75, number average fiber diameter 10 μm, number average fiber length 3
mm, aspect ratio 300, silane coupling agent treatment.

Examples 1 to 5 and Comparative Examples 1 to 8 Each of the components shown in Tables 1 and 2 was mixed with a stabilizer in a Henschel mixer, and then PCM-30 manufactured by Ikegai Tekko KK
Cylinder set temperature 280-34 using a twin-screw extruder
Molded product which was kneaded at 4 ° C while devolatilizing and was injection molded at a molding temperature of 280 to 344 ° C and a mold temperature of 80 to 100 ° C using a PS40E5ASE type injection molding machine manufactured by Nissei Plastic Co., Ltd. Physical properties were measured as follows. Tensile properties, deflection temperature under load (TDUL): ASTM
No. 4 tensile dumbbell, test piece for TDUL measurement (127 mm
(Long x 12.7 mm wide x 6.4 mm thick) was molded, and the tensile properties and TDUL (load 18.6 kg) were measured according to ASTM D638 and ASTM D648, respectively.

Flexural modulus: Measured according to ASTM D790 on a test piece (6.4 mm thick). Izod impact strength: A test piece (6.4 mm thick) was measured according to JIS K7110 without notch. Weld portion strength, non-weld portion strength: The test piece shown in FIG. 1 was molded from the composition of the present invention. This test piece has a thickness of 3 m
m, the outer dimension was 64 mm, and the inner dimension was 38 mm. The shaded area including the weld line shown in FIG. 1 (64 × 13 m)
m) is cut out, distance between spans is 40 mm, bending speed is 2 m
Bending strength was measured in m / min. In addition, from the test piece of the same shape to the non-weld part (64 × 1
3 mm) was cut out and the bending strength was measured in the same manner.
The results are shown in Tables 1 and 2. It can be seen that the liquid crystal polyester resin composition of the present invention is excellent in heat resistance and mechanical properties, particularly tensile properties, weld strength and impact resistance, and is inexpensive.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

Industrial Applicability The liquid crystal polyester resin composition of the present invention retains the excellent heat resistance and mechanical properties of liquid crystal polyester, has improved tensile strength and weld strength, and is inexpensive. The resin composition is suitably used for molded articles, sheets, tubes, films, fibers, laminates, coating materials and the like by injection molding or extrusion molding by taking advantage of such characteristics.

[Brief description of drawings]

FIG. 1 is a view showing a shape of a test piece for measuring weld strength and non-weld strength.

[Explanation of symbols]

1. Weld line. 2. Cutout part. 3. Gate.

Claims (5)

(57) [Claims] 1. A liquid crystal polyester (A), and (B)
(A) 50 to 99% by weight of ethylene units, (b) 0.1 to 30% by weight of unsaturated carboxylic acid glycidyl ester units or unsaturated glycidyl ether units, and (c) 0 to 0 of ethylenically unsaturated ester compound units. 50% by weight of an epoxy group-containing ethylene copolymer, and (C) a number average fiber diameter of 5 to 25 μm and a number average fiber length of 30 to 100.
0 μm and number average fiber length / number average fiber diameter of 2 to 150
The surface-untreated glass fiber is contained, and the ratio of the component (A) to the component (B) is 55.0 to 99.9% by weight of the component (A) and 45.0 to 0 of the component (B). The liquid crystal polyester resin composition is 1% by weight, and the weight sum of the components (A) and (B) is 50 to 99% by weight, and the component (C) is 50 to 1% by weight. 2. The liquid crystal polyester resin composition according to claim 1, wherein the liquid crystal polyester (A) is obtained by reacting an aromatic dicarboxylic acid, an aromatic diol and an aromatic hydroxycarboxylic acid. object. 3. The liquid crystal polyester resin composition according to claim 1, wherein the liquid crystal polyester (A) is obtained by reacting a combination of different aromatic hydroxycarboxylic acids. 4. The liquid crystal polyester resin composition according to claim 1, wherein the liquid crystal polyester (A) is composed of the following repeating units. [Chemical 1] 5. The liquid crystal polyester resin composition according to claim 1, wherein the liquid crystal polyester (A) is composed of the following repeating units. [Chemical 2]