JP2003192878A - Thermotropic liquid crystalline polymer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silica-containing thermotropic liquid crystalline polymer composition having high surface smoothness without containing silica having poor dispersion in the product and used for injection molding for precision components without lowering productivity. <P>SOLUTION: This thermotropic liquid crystalline polymer composition is obtained by uniformly mixing a spherical silica having 0.1-5.0 μm average primary particle diameter with an ester compound of at least one kind of alcohol selected from neopentyl alcohol, neopentyl glycol and pentaerythritol with a 10-30C higher fatty acid, mechanically and physically pressing the resultant mixture to provide a pressed and granulated substance having ≥0.5 degree of compaction and compounding the granulated substance in an amount of 20-80 wt.% based on total amount of the composition and melting and kneading the compound. In the polymer composition, silica aggregate having ≥60 μm size does not exist. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermotropic liquid crystalline polymer composition having a high concentration of spherical silica, a method for efficiently producing the composition, and a good surface obtained by injection molding the composition. The present invention relates to a molded product suitable for precision parts that require smoothness and high dimensional accuracy.

[0002]

2. Description of the Related Art Thermotropic liquid crystalline polymers have excellent mechanical properties, linear expansion coefficient, dimensional accuracy, chemical resistance, and very good fluidity, so that they can be used in precision parts, audio-related parts, and electrical parts. -It is a polymer that is often used in electronic parts, but in injection molding, due to its strong anisotropy, various improperly-balanced molded products are formed, and in the cooling process after injection. In many cases, anisotropy was generated in the shrinking behavior, and a molded product having a wavy surface was often formed.

Therefore, conventionally, in injection molding using a thermotropic liquid crystalline polymer, a fibrous filler such as glass fiber, a plate-like filler such as glass flake, etc. in the resin,
Amorphous fillers such as silica are filled to reduce the anisotropy of characteristics.

However, when a fibrous filler or a plate-like filler is used, in a precision component requiring high precision, the surface irregularity is generated due to the influence of the exposed filler, so that the component having good surface smoothness. In addition, in the molding of cylindrical parts, the surface smoothness is hindered by the influence of the exposed filler, and the roundness of the inner and outer diameters and parts with high cylindricity are obtained. I can't.

In order to solve such a problem, Japanese Unexamined Patent Application Publication No. Hei 8 (1998)
Japanese Patent Publication No. 59965 proposes to control the anisotropy by filling a substantially spherical filler having a maximum diameter of 100 μm or less and an aspect ratio of 1.5 or less.

However, such a substantially spherical filler having a maximum diameter of 100 μm or less and an aspect ratio of 1.5 or less has a problem that the bulk density is large. That is, when the bulk density becomes large, the air contained in the filler at the time of kneading hinders the quantitative feed of the filler.
Therefore, conventionally, measures have been taken to use silica that has been spray-dried and granulated with water or the like and has improved fluidity and handleability. However, when the compression-granulated silica is used, a large number of silica aggregates that cause poor dispersion remain in the product, and the product quality is deteriorated. As described above, at present, a thermotropic liquid crystalline polymer composition that satisfies both the productivity and the surface smoothness and also achieves the reduction of anisotropy has not been obtained.

[0007]

In view of the above problems of the prior art, the present invention has high surface smoothness without containing poorly-dispersed silica in the product, and is precise without lowering productivity. Provided is a silica-containing thermotropic liquid crystalline polymer composition that can be used for injection molding of parts, and a precision molded article having good characteristics, high surface smoothness, and roundness formed by the composition. For the purpose of provision.

[0008]

Means for Solving the Problems The present inventor diligently studied the granular silica to be mixed with the thermotropic liquid crystalline polymer in order to achieve the above object, and found that a spherical spherical silica having an average primary particle diameter of 0.1 to 5.0 μm was selected. The present invention has been completed by finding that a compression granulated product having a compression degree of 0.5 or more obtained by homogeneously mixing with a specific fatty acid ester and then physically compressing is extremely effective.

That is, the present invention has an average primary particle diameter of 0.1 to 5.0 μm.
m spherical spherical silica is obtained by homogeneously mixing with an ester compound of at least one alcohol selected from neopentyl alcohol, neopentyl glycol and pentaerythritol and an ester compound of a higher fatty acid having 10 to 30 carbon atoms and then mechanically physically compressing the mixture. The composition is prepared by blending 20 to 80% by weight of the compressed granules having a degree of compression of 0.5 or more with respect to the entire composition and melt-kneading, and silica aggregates of 60 μm or more do not exist in the composition. And a thermotropic liquid crystalline polymer composition. Further, the present invention is an injection-molded article obtained by injection-molding the above composition, wherein the molded article has a surface image clarity value of 60 or more.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The thermotropic liquid crystalline polymer used in the present invention refers to a melt processable polymer having the property of forming an optically anisotropic molten phase. The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using a crossed polarizer. More specifically, the confirmation of the anisotropic molten phase is performed by Lei
This can be carried out by observing the molten sample placed on the Leitz hot stage under a nitrogen atmosphere at a magnification of 40 times using a tz polarization microscope. The liquid crystalline polymer applicable to the present invention, when inspected between orthogonal polarizers, normally transmits polarized light even if it is in a molten stationary state, and exhibits optical anisotropy.

The liquid crystal polymer as described above is not particularly limited, but is preferably an aromatic polyester or an aromatic polyesteramide, and a polyester partially containing the aromatic polyester or the aromatic polyesteramide in the same molecular chain. Is also in that range. These are 60
When dissolved in pentafluorophenol at a concentration of 0.1% by weight at 0 ° C., preferably at least about 2.0 dl /
Those having a logarithmic viscosity (IV) of g, more preferably 2.0 to 10.0 dl / g are used.

The aromatic polyester or aromatic polyesteramide as the liquid crystalline polymer applicable to the present invention is particularly preferably at least one selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic hydroxyamine and aromatic diamine. Aromatic polyesters and aromatic polyester amides having the above compound as a constituent.

More specifically, (1) a polyester mainly composed of one or more kinds of aromatic hydroxycarboxylic acid and its derivative; (2) mainly (a) one kind of aromatic hydroxycarboxylic acid and its derivative. Or two or more and (b) one or more of an aromatic dicarboxylic acid, an alicyclic dicarboxylic acid and a derivative thereof, and (c) an aromatic diol, an alicyclic diol, an aliphatic diol and a derivative thereof. Polyester consisting of at least one kind or two or more kinds; (3) Mainly (a) one or more kinds of aromatic hydroxycarboxylic acid and its derivative, and (b) aromatic hydroxyamine, aromatic diamine and its From one or more kinds of derivatives and (c) one or more kinds of aromatic dicarboxylic acids, alicyclic dicarboxylic acids and their derivatives. (4) Mainly (a) one or more aromatic hydroxycarboxylic acids and their derivatives, and (b) one or more aromatic hydroxyamines, aromatic diamines and their derivatives. , (C) one or more aromatic dicarboxylic acids, alicyclic dicarboxylic acids and derivatives thereof,
(D) Polyesteramides comprising at least one or more of aromatic diols, alicyclic diols, aliphatic diols and their derivatives. Further, if necessary, a molecular weight modifier may be used in combination with the above constituent components.

Preferable examples of specific compounds constituting the liquid crystalline polymer 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 general formula (II); terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6 -Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid and compounds represented by the following general formula (III); aromatic amines such as p-aminophenol and p-phenylenediamine.

[0015]

[Chemical 1]

(However, X is a group selected from alkylene (C _{1 to} C ₄ ), alkylidene, -O-, -SO-, -SO _2- , -S-, -CO-, Y:-(CH ₂ ) _n- (n = 1 to 4), -O (CH ₂ ) _n O- (n =
Groups selected from 1 to 4)) Particularly preferred liquid crystalline polymers to which the present invention is applied include p-hydroxybenzoic acid and 6-hydroxy-2-
Aromatic polyesters and polyester amides containing an aromatic hydroxycarboxylic acid composed of naphthoic acid as a main constituent unit component.

Next, the silica used in the present invention will be described. In the present invention, spherical spherical silica having an average primary particle size of 0.1 to 5.0 μm, preferably 0.2 to 2.0 μm is used as a raw material component. Here, the true spherical shape means that the aspect ratio (ratio of the major axis of the particle to the minor axis) is 1.2 or less and the particle is substantially spherical. The use of such spherical silica as a raw material component is essential for obtaining an injection-molded article having good surface smoothness. In the present invention, the productivity is increased by further uniformly mixing a specific fatty acid ester with silica having primary particles having such characteristics and subjecting it to mechanical compression. That is, it was possible to eliminate silica aggregates having a particle size of 60 μm or more in the composition by using a compression granulated product having a compression degree of 0.5 or more obtained by uniformly mixing a specific fatty acid ester.

The fatty acid ester used here is an ester compound of at least one alcohol selected from neopentyl alcohol, neopentyl glycol and pentaerythritol and a higher fatty acid having 10 to 30 carbon atoms, and particularly preferably penta Erythritol tetrastearate. The amount of such fatty acid ester blended is 0.6 to 2.0% by weight, preferably 1.0
~ 1.5% by weight.

The method of uniform mixing is not particularly limited, but it is desirable to use a mixer such as a Henschel mixer or a Reedige mixer. As the stirring condition, the purpose is to uniformly mix the fatty acid ester with the silica particles before physical compression.Therefore, the faster the stirring speed, the shorter the time required.However, if the stirring speed is too high, contamination due to abrasion of the mixer will occur. Is mixed, so it is desirable that it is fast enough to prevent contamination. Further, the fatty acid ester may be mixed as a solid as it is, or may be dissolved in an organic solvent and then gradually added. The latter method has the advantage that it can be mixed more uniformly, but requires a drying step for removing the organic solvent after mixing.
The organic solvent is not particularly limited as long as it can dissolve the fatty acid ester, and toluene, isopropanol or the like can be used. The stirring time can be shortened by preferably heating and mixing the mixer for uniform mixing. The heating temperature is not particularly limited, but a temperature at which the fatty acid ester melts is desirable.

The physical compression uses a roll pressing method in which powder is supplied between two rolls which bite in opposite directions and freely rotate, and compression molding is performed by rotation of the rolls. With the roll pressing method, both briquetting in which briquette pockets are engraved on the roll surface and compacting using a flat roll can be used, but compacting is preferred. Generally, in compacting, the granules are granulated in a sheet form, and crushing and sizing treatment are required as a post-process, but in the present invention, since the amount of fatty acid ester is small, granules are granulated in a flake form. Therefore, there is an advantage that a post process can be omitted.

The compacting granulation pressure can be adjusted by the powder supply amount, roll rotation number, roll gap, and roll hydraulic pressure, but it can also be adjusted by using a pre-compression screw that forces the powder into the roll. Is possible. In this case, the granulation pressure can be adjusted by the rotation speed of the screw.

When the fatty acid ester is mixed with silica, the higher the granulation pressure is, the more the moldability of the granulated product is improved, the compression degree of the granulated product is increased, and the fluidity is improved. Roll line pressure
At a low pressure of less than 150 kgf / cm, the granulated product tends to collapse and the fluidity of the molded silica granules decreases, so in order to maintain the fluidity, the roll linear pressure is 150 kgf / cm or more, preferably 300 kgf / cm. The above is desirable.

The compressed granules obtained by homogeneously mixing with the fatty acid ester and physically compressing the mixture preferably have a compressibility of 0.5 or more. Here, the degree of compression is the difference between the apparent specific gravity before granulation and the apparent specific gravity after granulation.

The degree of compression is extremely important for improving the production efficiency of the thermotropic liquid crystalline polymer composition, and if the degree of compression is less than 0.5, the productivity will be extremely reduced.

Uniform mixing of the fatty acid ester with the spherical silica at the time of physical compression is important for obtaining the effect of the present invention, and if the fatty acid ester is not mixed, the productivity is improved. Many silica aggregates remain in the product after extrusion. Since the silica aggregate deteriorates the surface roughness of the product, the surface smoothness of the precision molded product deteriorates, and the dimensional accuracy is affected accordingly. On the contrary, when the specific fatty acid ester is mixed and compression granulated, the fatty acid ester controls the binding force between particles and the cohesive force appropriately, so that the silica aggregate does not remain in the product after extrusion, A good precision molded product can be obtained.

Further, since the fatty acid ester itself has the effect of improving the mold releasability, it is possible to excellently extrude the product during the extrusion of the precision component during the molding, and thus the deformation,
It is possible to prevent breakage and obtain a good precision molded product.

The content of the fatty acid ester in the resin composition is 0.1 to 0.5% by weight. If it is less than 0.1% by weight, the releasability is insufficient and the molded product may be deformed or destroyed depending on its shape. If it exceeds 0.5% by weight, the fatty acid ester oozes out from the molded product and the moldability deteriorates.

It is desirable that silica aggregates are not present in the product. When a large amount of residual silica aggregate is present, it is not preferable in terms of surface smoothness and the like. From the above points, it is desirable that there are no silica aggregates in the product, but silica aggregates of less than 60 μm have a practically smooth surface, and silica aggregates of less than 60 μm are practically no problem. .

From the viewpoint of reducing the anisotropy without deteriorating the properties such as strength and dimensional stability of the resin, the filling amount of the compression granulated product prepared as described above is a composition containing the thermotropic liquid crystalline polymer. It is 20 to 80% by weight in the product. If it is less than 20% by weight, the effect of reducing anisotropy will not be exhibited, and conversely if it exceeds 80% by weight, the fluidity of the resin will decrease and the moldability will deteriorate, and the mechanical properties of the molded article will decrease, which is preferred. Absent. From the viewpoint of effectively reducing anisotropy while maintaining good moldability, a more preferable range of the filling amount is 40 to 60% by weight.

In the present invention, the method for producing the thermotropic liquid crystalline polymer composition is not particularly limited,
It is desirable to uniformly melt-knead the above-mentioned compressed granulation product and the thermotropic liquid crystalline polymer using a twin-screw extruder having a degassing port.

The composition of the present invention includes, in addition to the thermotropic liquid crystalline polymer, a thermoplastic resin which does not auxiliary form a small amount of an anisotropic molten phase and a thermosetting resin in a range that does not impair the effects of the present invention. You may mix resin. The resin that does not form such an anisotropic molten phase may be compatible or incompatible with the thermotropic liquid crystalline polymer.

Examples of the thermoplastic resin which does not form an anisotropic molten phase include polyethylene, polypropylene, polybutylene, polybutadiene, polyisoprene, polyvinyl acetate, polyvinyl chloride, polyvinylidene, polystyrene, acrylic resin, ABS resin, AS. Resin, BS resin, polyurethane, silicone resin, polyacetal,
Polycarbonate, polyethylene terephthalate, polybutylene terephthalate, aromatic polyester, polyamide, polyacrylonitrile, polyvinyl alcohol,
Polyvinyl ether, polyether imide, polyamide imide, polyether ether imide, polyether ether ketone, polyether sulfone, polysulfone,
Examples thereof include polyphenylene sulfide and polyphenylene oxide. Examples of the thermosetting resin that does not form an anisotropic molten phase include phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, and alkyd resin. be able to.

In the composition of the present invention, if necessary, for example, a stabilizer such as a plasticizer, an antioxidant and an ultraviolet absorber, a flame retardant, a coloring agent such as a dye or a pigment, a foaming agent, and a divinyl type. A compound, a crosslinking agent such as a peroxide or a vulcanizing agent, a low molecular weight organic compound as a lubricant for improving fluidity and releasability, and the like can be appropriately added.

[0034]

The compression granules filled in the resin are present in a high ratio around the liquid crystal polymer molecules melted at the time of injection molding, prevent each molecular chain from flowing in the same direction, and Reduces the anisotropy of properties. At this time, the silica particles in the molten resin do not agglomerate to form coarse protrusions due to the interaction between the shape and the size thereof, and do not significantly protrude to the outer periphery of the molded product, so that they contact the mold of the molded product. The surface property of the resin is not hindered. Therefore, the molded product has a high surface smoothness (a surface with little unevenness in the case of plate-shaped or disk-shaped parts, a high roundness and cylindricity in the case of cylinders, cylinders, etc.)
Is expressed. In order to exhibit high surface smoothness, it is necessary that the surface image clarity value of the molded product is 60 or more.
Surface image clarity is a measure of how sharply an image is projected when an object appears on the surface, and the larger this value is, the better the surface property is. It is necessary to use the composition of the present invention in order to obtain a molded product having a value of 60 or more even if a mold having a good surface is used.

Therefore, it can be obtained by injection-molding the composition filled with the silica particles having such a special shape,
Precision parts such as optical fiber connectors, fuel pump impellers, centering hubs for hard disk drives, and nozzles for laser beam printers have excellent characteristics (strength, heat resistance, etc.) and extremely high roundness and cylindricity. Become.

[0036]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto. still,
The evaluation method and the like are as follows. (Production Method of Silica Particles Used) [Production Method of True Spherical Silica] The true spherical silica fine particles form a chemical flame by a burner in an atmosphere containing oxygen, and the target oxide fine particles are formed in the chemical flame. A method in which metal powder forming a part is added in an amount such that a dust cloud is formed and detonation is caused to obtain oxide fine particles,
Silica (Admafine SO-C2; having an average primary particle size of 0.5 μm) synthesized by the MC method (Vapourized Metal Combution Method) (Japanese Patent Publication No. 1-55201).
(Manufactured by Admatechs) was used.・ Silica (1); average primary particle size 0.5 μm, apparent specific gravity 0.44
(G / cc) untreated, non-granulated, spherical silica synthesized by the VMC method and having a compression degree of 0.・ Silica (2); 20 parts by weight of silica (1) and 80 parts by weight of water are mixed to prepare a slurry, and the slurry is supplied to a rotary disk type spray dryer, and the dry air temperature is 240 ° C.
It is a silica granulated by the spray drying granulation method, and the average particle size after granulation is 70 μm (microscopic observation), and the apparent specific gravity after granulation.
1.01 (g / cc) with a compression degree of 0.57.・ Silica (3); 100 parts by weight of silica (1) was put into a Ledige mixer equipped with a crushing blade, and the crushing shaft rotation speed was 3000 rpm.
While stirring in, a 30% concentration toluene solution containing 0.6 part by weight of pentaerythritol tetrastearate was added dropwise over 2 minutes, and the mixture was stirred and granulated for 30 minutes after the addition. After that, it is a granulated silica from which toluene was removed by heating at 140 ° C. for 2 hours using a hot air circulation type dryer, and the average particle size after granulation is 1.5 mm (sieving method, weight basis). Apparent specific gravity 0.8
7 (g / cc), compression degree 0.43.・ Silica (4); Silica (1) is supplied by a compacting granulator which is a roll press method, powder supply rate 300 kg / h, roll speed 30 rpm, roll hydraulic pressure 150 kg / cm ² , roll gap 1.
Granulated silica that is mechanically compressed and granulated with 0 mm, no pre-compression screw, and compression pressure (roller linear pressure) 400 kgf / cm, average particle size after granulation 0.4 mm (sieving method, weight basis), granulation Later apparent specific gravity of 0.94 (g / cc) and compression of 0.50. Silica (5); 100 parts by weight of silica (1) in a Loedige mixer equipped with a crushing blade heated to 80 ° C with a boiler,
1 part by weight of pentaerythritol tetrastearate was added, and the mixture was heated and mixed for 15 minutes at a spindle speed of 50 rpm and a crushing shaft speed of 3000 rpm. Then, using a compacting granulator, which is a roll pressing method, the powder supply rate 80 kg / h, roll speed 20 rpm, roll hydraulic pressure 100 kg / cm ² , roll gap 0.5 mm.
, Without pre-compression screw, compression pressure (roll linear pressure) 1
Granulated silica that is mechanically compressed and granulated at 50 kgf / cm,
The average particle size after granulation is 0.4 mm (sieving method, weight basis), the apparent specific gravity after granulation is 0.91 (g / cc), and the degree of compression is 0.47. Silica (6); 100 parts by weight of silica (1) in a Loedige mixer equipped with a crushing blade heated to 80 ° C with a boiler,
1 part by weight of pentaerythritol tetrastearate was added, and the mixture was heated and mixed for 15 minutes at a spindle speed of 50 rpm and a crushing shaft speed of 3000 rpm. After that, by a compacting granulator which is a roll pressing method, the powder supply amount 100 kg / h, the roll rotation speed 22 rpm, the roll hydraulic pressure 170 kg / cm ² , the roll gap 0.25.
mm, pre-compression screw rotation speed 60 rpm, compression pressure (rolling line pressure) 850 kgf / cm, which is a granulated silica mechanically compressed and granulated. Average particle size after granulation 0.6 mm (sieving method, weight basis),
An apparent specific gravity after granulation of 0.98 (g / cc) and a compressibility of 0.54. -Silica (7): Pentaerythritol tetrastearate-containing silica which has been mixed and dried by changing the mixing time to 20 minutes in the production conditions of silica (3), and further silica.
Granulated silica that is mechanically compressed and granulated under the compression conditions of (4), the average particle size after granulation is 0.55 mm (sieving method, weight basis), the apparent specific gravity after granulation is 0.97 (g / cc), A compression degree of 0.53. -Silica (8); 20 parts by weight of silica (1), 80 parts by weight of water, and 0.2 parts by weight of stearic acid are mixed to prepare a slurry, and the slurry is supplied to a rotary disk type spray dryer to obtain a dry air temperature of 240 Silica granulated by spray drying granulation method at ℃, average particle size after granulation 70μm (microscopic observation), apparent specific gravity after granulation 1.01 (g / cc), compressibility 0.57
Things. (Productivity) The productivity of the polymer composition was judged by using the composition containing the above silica particles, and regarding the amount of pellets extruded by the twin-screw extruder, whether 100 kg or more per hour can be extruded. When it was possible to extrude, it was marked with ◯, and when it was impossible to feed, it was marked with x. (Amount of fatty acid ester) Perkin Elmer DSC-7
Was used to measure the heat of fusion of the fatty acid ester in the pellet, and the amount of the fatty acid ester in the pellet was quantified from the ratio with the heat of fusion of the pure fatty acid ester.・ Test conditions Measurement temperature: 120 ℃ (3 min hold) → 0 ℃ Temperature decrease rate: 10 ℃ / min (Manufacture and evaluation of molded products) The obtained compound product is injection condition described below, one side is 60 mm, thickness is 3 mm. Was molded into a square flat plate.

The undispersed silica of this flat plate is treated with soft X-ray (SOF
TEX SV-100A). The minimum aggregate that can be confirmed by soft X-rays is about 20 μm, and since smaller aggregates cannot be confirmed, it is assumed that there is substantially no aggregate. This time the agglomerate determination method is bad if the size of the largest undispersed silica agglomerate is 60 μm or more, ×, ○ if the size of the largest undispersed silica agglomerate is less than 60 μm, undispersed silica agglomerate If is not confirmed, it is written as ◎.

Using this flat plate, the image clarity was measured as follows. <Measurement of image clarity> Image measurement instrument (Suga Test Instruments, type IC
M-1D). Light is incident on the molded sample at an angle of 45 °, reflected light at 45 ° is passed through an optical comb with a width of 1.0 mm, and the maximum value M of the bright part and the minimum value m of the dark part of the transmitted light of the optical comb are measured by the photoreceiver. Measured and determined the image clarity (%) by the following formula (light source: tungsten filament, light wavelength: 400 to 70)
0 nm).

Image clarity (%) = [(M-m) / (M +
m)] × 100 If this value is large, the image clarity is good, and the sample plate is smooth, and if it is small, the sample plate surface is rough.

The flexural strength (FS) and flexural modulus (FM) of the molded product were measured according to ISO178.

Molding machine; JSW J75SSII-A Cylinder temperature; 300-300-290-280 ° C Mold temperature; 90 ° C Injection speed; 2 m / min Holding pressure; 58.8 MPa cycle; Injection holding pressure 7 sec + cooling 7 sec Screw rotation speed 100 rpm screw back pressure; 3.5 MPa Furthermore, in order to evaluate the releasability, the obtained compound product was molded into a precision molded product having the cross-sectional shape shown in FIG. The case was judged as ×, and the case of releasing the mold without any problem was judged as ○.・ Molding conditions Resin drying temperature: 150 ℃ x 5 hr Cylinder temperature: 300 ℃ Mold temperature: 70 ℃ Injection pressure: 800 kg / cm ² Injection speed: 3.4 m / min Holding pressure: 500 kg / cm ² Screw rotation speed: 300 rpm cycle; 30 sec Examples 1-2, Comparative Examples 1-6 100 parts by weight of thermotropic liquid crystalline polymer (manufactured by Polyplastics Co., Ltd., Vectra A950; registered trademark) and 100 parts by weight of various silica particles are added to a twin-screw extruder (Nippon Steel). TEX-30α manufactured by Tosho Co., Ltd. was melt-kneaded at a resin temperature of 300 ° C. to form pellets. The various silica particles were kneaded with the thermotropic liquid crystalline polymer by side feed from the middle of the extruder.

Table 1 shows the results of the above-mentioned evaluation using this pellet.

Since silica, which is generally problematic in productivity, has good dispersibility, no aggregates are present in the product. On the contrary, since silica having excellent metering property has poor dispersibility, many silica aggregates remain in the product. Since Comparative Examples 1 to 6 have such a problem, it is difficult to make both properties compatible with each other. On the other hand, as is clear from the results of Examples 1 and 2, the use of silica that has been subjected to a specific treatment as in the present invention made it possible to achieve both of the above characteristics. Further, the general physical properties of the obtained molded product are not deteriorated.

[0044]

[Table 1]

[Brief description of drawings]

FIG. 1 is a diagram showing a precision molded product used for evaluation of releasability in Examples.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 77/12 C08L 77/12 // B29K 67:00 B29K 67:00 105: 16 105: 16 309: 00 309: 00 (72) Inventor Kazushi Watanabe, 973 Miyajima, Fuji City, Shizuoka Prefecture, within Polyplastix Co., Ltd. (72) Inventor Abe, 1099 Marune, Kuronesa, Miyoshi-cho, Nishikamo-gun, Aichi Prefecture 20 Inside Admatechs Co., Ltd. (72 ) Inventor Hirokazu Sugiura 1099 Marune, Kuronesa, Miyoshi-cho, Nishikamo-gun, Aichi 20 Admatex Co., Ltd. (72) Inventor, 1099 Marune, Kuroshisa, Miyoshi-cho, Nishikamo-gun, Aichi 20 F-term in Admatex Co., Ltd. (Reference) 4F071 AA43 AA57 AB26 AC10 AD07 AF35 AG12 AG22 BA01 BB05 4F201 AA24 AA29E AB07 AB17 AC01 BA01 BC01 BC02 BC12 BC19 BC37 BD04 BK02 BK1 3 BK27 BK36 BK75 4F206 AB17 AC07 AF16 AM35 JA07 4J002 CF181 CL081 DJ016 FA086 FB086

Claims (6)

[Claims] 1. True spherical silica having an average primary particle diameter of 0.1 to 5.0 μm is at least 1 selected from neopentyl alcohol, neopentyl glycol and pentaerythritol.
20% to 20% of the whole composition of the granulation product having a compression degree of 0.5 or more obtained by mechanically physically compressing after uniformly mixing an ester compound of a different alcohol and a higher fatty acid having 10 to 30 carbon atoms.
A composition obtained by mixing 80% by weight and melt kneading,
A thermotropic liquid crystalline polymer composition characterized in that silica aggregates of m or more do not exist in the composition. 2. True spherical silica is produced by the VMC method (Vapourized).
The thermotropic liquid crystalline polymer composition according to claim 1, which is synthesized by the Metal Combution Method). 3. The thermotropic liquid crystalline polymer composition according to claim 1, wherein the ester compound is pentaerythritol tetrastearate. 4. The compounding amount of the ester compound of at least one alcohol selected from neopentyl alcohol, neopentyl glycol, and pentaerythritol and the higher fatty acid having 10 to 30 carbon atoms is 0.1 to the whole composition.
The thermotropic liquid crystalline polymer composition according to claim 1, which is 0.5% by weight. 5. A twin-screw extruder having a degassing port is used, and spherical silica having an average primary particle size of 0.1 to 5.0 μm is mixed with at least one alcohol selected from neopentyl alcohol, neopentyl glycol and pentaerythritol. It is necessary to uniformly melt-knead the compression granules having a compression degree of 0.5 or more obtained by mechanically physically compressing an ester compound with a higher fatty acid having 10 to 30 carbon atoms and the thermotropic liquid crystalline polymer. A method for producing a thermotropic liquid crystalline polymer composition, which is characterized. 6. The injection molding of the thermotropic liquid crystalline polymer composition according to claim 1.
An injection-molded product whose surface image clarity value is 60 or more.