JP5869983B2 - Liquid crystalline resin composition - Google Patents

Description

  The present invention relates to a liquid crystalline resin composition containing talc.

  Various attempts have been made to obtain a liquid crystalline resin composition by adding talc to a liquid crystalline resin. However, a resin characterized by high heat resistance and high dimensional accuracy, such as a liquid crystalline resin, has various problems at high temperatures. That is, when a liquid crystalline resin composition containing talc in a liquid crystalline resin is molded, the liquid crystalline resin is molded by heating and melting, but the melting temperature of the liquid crystalline resin is much higher than that of other resins. It becomes very hot. And a peculiar phenomenon expresses due to such high temperature. For example, a reaction such as thermal decomposition or hydrolysis of a liquid crystalline resin by a catalytic action of an impurity metal in talc or, in some cases, talc itself. Due to this, a liquid crystalline resin composition containing talc has not been sufficient in mechanical properties and heat resistance in the past.

Various liquid crystalline resin compositions that solve the above problems have been proposed (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses that talc having a total content of Fe ₂ O ₃ and Al ₂ O ₃ of less than 1% by weight and an average particle diameter of 2.5 to 3.5 μm with respect to 100 parts by weight of a predetermined copolymerized polyester. A heat resistant resin composition containing 5 to 200 parts by weight is described.
Patent Document 2 discloses a composition containing talc containing only 35% to 65% aromatic polyester and 1% to 60% of a material that can be decomposed at an elevated temperature with a minimum content. Things are listed.
However, in either case, the moldability and heat resistance have not reached sufficient levels, and a liquid crystalline resin composition with even better moldability and heat resistance is desired.

Japanese Patent Laid-Open No. 4-202557 JP 59-3615 A

  This invention is made | formed in view of the said conventional problem, and it aims at providing the liquid crystalline resin composition excellent in molding processability and heat resistance.

The present invention for solving the above problems is as follows.
(1) A liquid crystalline resin composition comprising 5 to 200 parts by mass of talc with respect to 100 parts by mass of a liquid crystalline resin,
The total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is 2.5% by mass or less with respect to the total solid content of the talc, and the total content of Fe ₂ O ₃ and Al ₂ O ₃ is 1 More than 0.0 mass% and 2.0 mass% or less, and the CaO content is less than 0.5 mass%.

(2) The liquid crystalline resin composition according to (1), wherein the talc has a particle size (D50%) measured by a laser diffraction method of 4.0 to 20.0 μm.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystalline resin composition excellent in molding processability and heat resistance can be provided.

The liquid crystalline resin composition of the present invention is a liquid crystalline resin composition comprising 5 to 200 parts by mass of talc with respect to 100 parts by mass of the liquid crystalline resin, and Fe based on the total solid content of the talc. The total content of ₂ O ₃ , Al ₂ O ₃ and CaO is 2.5% by mass or less, and the total content of Fe ₂ O ₃ and Al ₂ O ₃ is more than 1.0% by mass and 2.0% by mass or less. And the CaO content is less than 0.5% by mass.
Each component is described in detail below.

[Liquid crystal resin]
The liquid crystalline resin used in the present invention refers to a melt processable polymer having a property capable of forming an optically anisotropic molten phase. The property of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. More specifically, the anisotropic molten phase can be confirmed by using a Leitz polarizing microscope and observing a molten sample placed on a Leitz hot stage under a nitrogen atmosphere at a magnification of 40 times. When the liquid crystalline resin applicable to the present invention is inspected between crossed polarizers, the polarized light is normally transmitted even in a molten stationary state, and optically anisotropic.

  Although it does not specifically limit as a kind of above liquid crystalline resin, It is preferable that it is aromatic polyester or aromatic polyesteramide. Moreover, the polyester which partially contains aromatic polyester or aromatic polyester amide in the same molecular chain is also in that range. They preferably have a logarithmic viscosity (IV) of at least about 2.0 dl / g, more preferably 2.0-10.0 dl / g when dissolved in pentafluorophenol at 60 ° C. at a concentration of 0.1% by weight. .) Are preferably used.

  The aromatic polyester or aromatic polyester amide as the liquid crystalline resin applicable to the present invention is particularly preferably at least one compound selected from the group of aromatic hydroxycarboxylic acids, aromatic hydroxyamines, and aromatic diamines. Aromatic polyesters and aromatic polyester amides as constituent components.

More specifically,
(1) A polyester mainly composed of one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(2) mainly (a) one or more of aromatic hydroxycarboxylic acids and derivatives thereof; and (b) one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids and derivatives thereof; c) Polyester comprising at least one or more of aromatic diol, alicyclic diol, aliphatic diol and derivatives thereof;
(3) mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof; (b) one or more aromatic hydroxyamines, aromatic diamines and derivatives thereof; and (c). A polyesteramide comprising one or more of aromatic dicarboxylic acid, alicyclic dicarboxylic acid and derivatives thereof;
(4) mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof; (b) one or more aromatic hydroxyamines, aromatic diamines and derivatives thereof; and (c). One or more of aromatic dicarboxylic acid, alicyclic dicarboxylic acid and derivatives thereof; and (d) at least one or more of aromatic diol, alicyclic diol, aliphatic diol and derivatives thereof, and And polyester amides composed of Furthermore, you may use a molecular weight modifier together with said structural component as needed.

  Preferable examples of specific compounds constituting the liquid crystalline resin applicable to the present invention include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; 2,6-dihydroxynaphthalene, 1 , 4-dihydroxynaphthalene, 4,4′-dihydroxybiphenyl, hydroquinone, resorcin, aromatic diols such as compounds represented by the following general formula (I) and the following general formula (II); terephthalic acid, isophthalic acid, 4, Aromatic dicarboxylic acids such as 4′-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid and compounds represented by the following general formula (III); aromatic amines such as p-aminophenol and p-phenylenediamine It is done.

（Ｘ：アルキレン（Ｃ１〜Ｃ４）、アルキリデン、−Ｏ−、−ＳＯ−、−ＳＯ_２−、−Ｓ−、−ＣＯ−より選ばれる基である）

(X: alkylene (C1 -C4), _{alkylidene, -O -, - SO -,} - SO 2 -, - S -, - is a group selected from CO-)

（Ｙ：−（ＣＨ_２）_ｎ−（ｎ＝１〜４）、−Ｏ（ＣＨ_２）_ｎＯ−（ｎ＝１〜４）より選ばれる基である。）

(Y is a group selected from — (CH ₂ ) _n — (n = 1 to 4) and —O (CH ₂ ) _n O— (n = 1 to 4).

The liquid crystalline resin used in the present invention can be synthesized by a known method using a direct polymerization method or a transesterification method from the above monomer compound (or a mixture of monomers), but usually a melt polymerization method or a slurry. A polymerization method or the like is used. The above compounds having ester-forming ability may be used for polymerization as they are, or may be modified from a precursor to a derivative having ester-forming ability in the previous stage of polymerization. In the polymerization, various catalysts can be used. Typical examples include dialkyl tin oxide, diaryl tin oxide, titanium dioxide, alkoxy titanium silicates, titanium alcoholates, carboxylic acid alkalis and Examples include alkaline earth metal salts and Lewis acid salts such as BF ₃ . The amount of the catalyst used is generally about 0.001 to 1% by weight, particularly about 0.01 to 0.2% by weight, based on the total weight of the monomers. If the polymers produced by these polymerization methods are further necessary, the molecular weight can be increased by solid-phase polymerization by heating in a reduced pressure or an inert gas.

The melt viscosity of the liquid crystalline resin obtained by the above method is not particularly limited. Generally, those having a melt viscosity at a molding temperature of 10 Pa · s to 600 Pa · s at a shear rate of 1000 sec ⁻¹ can be used. However, those having a very high viscosity are not preferable because the fluidity is extremely deteriorated. The liquid crystalline resin may be a mixture of two or more liquid crystalline resins.

[talc]
As the talc used in the present invention, the total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is 2.5% by mass or less based on the total solid content of the talc, Fe ₂ O ₃ and Al The total content of ₂ O ₃ is more than 1.0% by mass and 2.0% by mass or less, and the content of CaO is less than 0.5% by mass. That is, the talc used in the present invention contains at least one of Fe ₂ O ₃ , Al ₂ O ₃ and CaO in addition to the main components SiO ₂ and MgO, and each component has the above content range. It contains.

In the talc, when the total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO exceeds 2.5% by mass, the moldability and heat resistance deteriorate. The total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is preferably 1.0% by mass or more and 2.0% by mass or less.
Further, in the talc, the total content of 1.0 mass% of talc _Fe 2 _{O 3} and _Al 2 _{O 3} is difficult to obtain, exceeds 2.0 mass%, moldability and heat resistance Gets worse. The total content of Fe ₂ O ₃ and Al ₂ O ₃ is preferably 1.0% by mass or more and 1.7% by mass or less.
Furthermore, in the talc, when the content of CaO is 0.5% by mass or more, moldability and heat resistance deteriorate. The content of CaO is preferably 0.01% by mass or more and 0.4% by mass or less.

  In the present invention, the particle size (D50%) of the talc measured by a laser diffraction method is preferably 4.0 to 20.0 μm from the viewpoint of preventing warpage deformation and maintaining fluidity. More preferably, it is 18 μm.

  On the other hand, in this invention, the said talc contains 5-200 mass parts with respect to 100 mass parts of liquid crystalline resin. When the content is less than 5 parts by mass, the effect of preventing warping deformation is small, and when it exceeds 200 parts by mass, the fluidity is deteriorated. The content is preferably 5 to 100 parts by mass, and more preferably 10 to 40 parts by mass.

  Commercially available products such as Crown Talc PP made by Matsumura Sangyo and MS-K made by Nippon Talc can be used as the talc.

[Other ingredients]
In the present invention, an inorganic filler other than talc may be blended. For example, glass fiber, asbestos fiber, silica fiber, silica / alumina fiber, potassium titanate fiber, boron fiber, silicon carbide fiber, carbon fiber, light calcium carbonate, heavy or finely powdered calcium carbonate, special calcium filler, etc. Calcium carbonate, meteorite, feldspar fine powder, montmorillonite, bentonite, etc., clay such as silane modified clay (aluminum silicate powder), silica (silicon dioxide) powder such as fused silica, synthetic silica, crystalline silica, diatomaceous earth Silica-containing compounds such as silica sand, pulverized natural minerals such as pumice powder, pumice balloon, slate powder, and mica powder, alumina-containing compounds such as alumina, alumina colloid (alumina sol), alumina white, aluminum sulfate, barium sulfate, Lithopone, calcium sulfate, molybdenum disulfide, Minerals such as phyto (graphite), glass beads such as glass beads, glass hollow bodies, glass flakes, foamed glass beads, fly ash spheres, volcanic glass hollow bodies, synthetic inorganic hollow bodies, single crystal potassium titanate, carbon nanotubes, Carbon hollow sphere, carbon 64 fullerene, anthracite powder, artificial cryolite, titanium oxide, magnesium oxide, basic magnesium, dolomite, potassium titanate, calcium sulfite, mica, asbestos, calcium silicate, aluminum powder, sulfide Examples include molybdenum.
These inorganic fillers may be used alone or in combination of two or more.

There is no limitation in particular as a method of obtaining a molded article using the liquid crystalline resin composition of this invention, A well-known method is employable. For example, the liquid crystalline resin composition of the present invention is put into an extruder, melted and kneaded into pellets, and the pellets are put into an injection molding machine equipped with a predetermined mold and injection molded to obtain a molded product. be able to.
As a melting temperature at the time of pelletizing, it is preferable to set it as 250-400 degreeC, and it is more preferable to set it as 300-380 degreeC.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Examples 1-6, Comparative Examples 1-5]
100 parts by mass of a liquid crystalline resin (LCP; manufactured by Polyplastics Co., Ltd., Vectra (registered trademark) LCP E950i) and glass fiber (ECS04T-790DE manufactured by Nippon Electric Glass Co., Ltd. (average fiber diameter 6 μm, length 3 mm) Biaxial extrusion of 27 parts by mass of chopped strand fiber), 55 parts by mass of talc, and 0.55 parts by mass of a release agent (pentaerythritol tetrabehenate, manufactured by Nippon Oil & Fats Co., Ltd., Nissan Electol WEP-5) The mixture was melt-kneaded and pelletized using a machine (Tex-30α manufactured by Nippon Steel Co., Ltd.) In each example and comparative example, talc having the composition described in Table 1 was used. , “Fe + Al + Ca” and “Fe + Al” are the total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO with respect to the total solid content of talc, respectively, Fe ₂ O ₃ represents the total content of Al ₂ O _{3. Further,} the content of each component in talc is a value obtained by analysis according to JIS M 8851, and the particle diameter is obtained by measurement by a laser diffraction method. Value.

The following evaluation tests were performed on the obtained resin composition (pellet).
(1) Melt viscosity Using the capillary rheometer (Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd .: piston diameter 10 mm), the above pellets are subjected to ISO under the conditions of a cylinder temperature of melting point + 20 ° C. and a shear rate of 1000 sec ^−1. The apparent melt viscosity was measured according to 11443. For the measurement, an orifice having an inner diameter of 1 mm and a length of 20 mm was used. The measurement results are shown in Table 1.
(2) Blister test 1/32 combustion test piece (with weld) under the condition that the molding cycle is 20 seconds using an injection molding machine (SE100DU manufactured by Sumitomo Heavy Industries, Ltd.). Molded into. The obtained test piece was sandwiched between hot presses at a specified temperature for 5 minutes, and then the surface was observed. The maximum temperature at which the surface did not swell was searched as BFT (Blister Free Temp). The sample divided by the weld was used as one specimen, and the specified temperature was set in increments of 10 ° C. in the range of 250 to 300 ° C., and measurement was performed. The measurement results are shown in Table 1.
(3) Metering time The above pellets are molded using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., SE30DUZ, screw diameter φ: 18 mm, measuring stroke length: 55 mm) under the condition of a screw speed of 150 rpm. The weighing time for each 20 shots was measured to obtain an average value. The obtained numerical values are shown in Table 1. In addition, it is judged that a thing with short measurement time has favorable moldability.

  From Table 1, in Examples 1-6, since the result of a blister test is 270 degreeC or more, all are excellent in heat resistance, Moreover, even if the measurement time is the longest, since it is more than 21 seconds, it is in forming workability. It turns out that it is excellent. On the other hand, in Comparative Examples 1-5, the result of the blister test is as low as 260 ° C. except for Comparative Example 3, and the measurement time is over 22 seconds, and the molding processability and heat resistance are good at the same time. It was not possible to achieve a good result.

Claims (2)

A liquid crystalline resin composition comprising 5 to 200 parts by mass of talc with respect to 100 parts by mass of a liquid crystalline resin,
The total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is 2.5% by mass or less with respect to the total solid content of the talc, and the total content of Fe ₂ O ₃ and Al ₂ O ₃ is 1 More than 0.0 mass% and 2.0 mass% or less, and CaO content is less than 0.5 mass%, The liquid crystalline resin composition characterized by the above-mentioned.   2. The liquid crystalline resin composition according to claim 1, wherein the talc has a particle size (D50%) measured by a laser diffraction method of 4.0 to 20.0 μm.