JP3267006B2 - Method for producing liquid crystalline resin composition pellets for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a liquid crystalline resin composition pellet for molding. More specifically, supply,
The present invention relates to a production method for obtaining a molding liquid crystalline resin composition pellet having a shape excellent in quantitativeness in a high yield.

[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 functions have been developed and marketed. Among them, optics characterized by a parallel arrangement of molecular chains. Anisotropic liquid crystal polymer
It is noted for its excellent moldability and mechanical properties.

As a method for producing a liquid crystalline polyester,
Known are a melt polymerization method (Japanese Patent Application Laid-Open No. 62-277427), a bulk polymerization method (Japanese Patent Application Laid-Open No. 57-151419), a solid phase polymerization method (Japanese Patent Application Laid-Open No. 60-190449), and mechanical strength. Fillers and other additives such as inorganic fillers, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, release agents, colorants, plasticizers, antistatic agents, flame retardants, etc. As a method for filling a plastic resin, a melt kneading method using an extruder is generally known.

Further, as a method for producing a thermoplastic resin composition pellet for molding, after the polymerization reaction is completed or after melt-kneading with a filler, a molten polymer is extruded into a gut shape through a die provided at a discharge outlet. Cooling by passing through a water bath, solidifying and cutting into pellets (cold cut method), cutting the molten polymer immediately after extrusion in air (hot cut method), and extruding and cutting the polymer in water ( An underwater cut method is known.

[0005] When the pellet production method is used, the pellet temperature at the time of cutting is usually the melting point (Tm) x
The temperature was below 0.3 ° C.

[0006]

However, the liquid crystal resin composition pelletized by these methods has a higher solidification rate than a general thermoplastic resin composition, so that pellets are cracked at the time of cutting, and debris / powder. Mixing, irregular shape, poor pelletization yield, and the resulting pellets clogging in the raw material supply port of the molding machine,
It was found that molding troubles such as variations in the supply amount were likely to occur.

[0007] Accordingly, an object of the present invention is to solve the above-mentioned problems and to produce a molding liquid crystalline resin composition pellet having a shape excellent in supplyability and quantitativeness in a high yield.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.

That is, the present invention provides a liquid crystalline resin composition for molding characterized in that when producing pellets of the liquid crystalline resin composition for molding, the pellet temperature during cutting satisfies the following equation: The present invention provides a method for producing a product pellet.

(Tm × 0.35) ≦ pellet temperature ≦
(Tm × 0.55) Here, Tm in the formula represents the melting point (° C.) of the liquid crystalline resin composition.

The liquid crystalline resin composition of the present invention includes the following (I), (II), (IV) or (I), (III), (I)
V) or 100 parts by weight of a liquid crystalline polyester comprising structural units of (I), (II), (III) and (IV), based on inorganic and / or organic fillers, additives, and other thermoplastic resins. It is a liquid crystalline resin composition filled with 0 to 200 parts by weight of one or more selected fillers.

[0012]

Embedded image (However, R ₁ in the formula is

Embedded image R ₂ represents one or more groups selected from

Embedded image Represents one or more groups selected from In the formula, X represents a hydrogen atom or a chlorine atom, and the structural units (II) and (II)
The sum of I) and the structural unit (IV) are substantially equimolar.) In the present invention, in the pelletization of the liquid crystalline resin composition obtained by the above polymerization reaction or melt kneading,
It is important to cut in a limited polymer temperature range, thereby suppressing the solidification of the discharge polymer surface,
It is possible to prevent a reduction in pelletization yield due to cracking of pellets, mixing of debris / powder, and irregular shapes, and to produce molding pellets having a shape excellent in feedability and quantitativeness.

The structural unit (I) is a structural unit of a polyester formed from p-hydroxybenzoic acid, and the structural unit (II) is 4,4'-dihydroxybiphenyl,
3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, phenylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,
The structural unit formed from an aromatic dihydroxy compound selected from 2,2-bis (4-hydroxyphenyl) propane and 4,4'-dihydroxydiphenyl ether, and the structural unit (III) is formed from ethylene glycol The structural unit (IV) is terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,6-
Naphthalenedicarboxylic acid, 1,2-bis (phenoxy)
Ethane-4,4'-dicarboxylic acid, 1,2-bis (2-
Structural units formed from aromatic dicarboxylic acids selected from chlorphenoxy) ethane-4,4'-dicarboxylic acid and diphenyletherdicarboxylic acid are shown. In particular, when a structural unit (III) is contained, R1 is

Embedded image Is at least 70 mol% of the structural unit (II)
But

Embedded image Is more preferably 70% or more of the structural unit (IV).

On the other hand, when the above structural unit (III) is not contained, R1 is

Embedded image R2 is

Embedded image Is particularly preferred.

The copolymerization amount of the above structures (I) to (IV) is optional. However, the following copolymerization amount is preferred from the viewpoint of fluidity.

That is, when the above-mentioned structural unit (III) is contained, the total of the above-mentioned structural units (I) and (II) is the structural unit (I) from the viewpoint of heat resistance, flame retardancy and mechanical properties .
60 to 95 mol% based on the total of (II) and (III)
Is preferable, and 82 to 93 mol% is more preferable. Also,
The structural unit (III) is composed of the structural units (I), (II) and (II)
It is preferably from 40 to 5 mol% based on the total of I) , and from 18 to
7 mol% is more preferred.

The molar ratio [(I) / (II)] of the structural unit (I) to (II) is preferably 75/25 to 95 / from the viewpoint of balance between heat resistance and fluidity. 5, more preferably 78/22 to 93/7. The structural unit (I
V) is substantially equimolar to the sum of structural units (II) and (III) .

On the other hand, when the above-mentioned structural unit (III) is not contained, the above-mentioned structural unit (I) is structural unit from the viewpoint of fluidity.
It is preferably from 40 to 90 mol%, more preferably from 60 to 88 mol%, based on the total of (I) and (II) , and the structural unit (IV) is substantially equivalent to the structural unit (II). Equimolar.

The method for polymerizing the liquid crystalline polyester in the present invention is not particularly limited, and it can be produced according to a known method for polycondensation of a liquid crystalline polyester. For example, the following method (1) or (2) can be used. However, the method (2) is particularly preferred.

(1) p-acetoxybenzoic acid and 4,
Diacylated aromatic dihydroxy compounds such as 4'-diacetoxybiphenyl and paradiacetoxybenzene and aromatic dicarboxylic acids such as terephthalic acid; polyesters and oligomers from ethylene glycol and aromatic dicarboxylic acids; A method for producing (β-hydroxyethyl) ester by a deacetic acid polycondensation reaction.

(2) p-hydroxybenzoic acid, 4,4 '
Aromatic dihydroxy compounds such as dihydroxybiphenyl and hydroquinone; aromatic dicarboxylic acids such as acetic anhydride and terephthalic acid; polyesters and oligomers from ethylene glycol and aromatic dicarboxylic acids; or bis (β-hydroxyethyl ) A method in which a phenolic hydroxyl group is acylated by reacting with an ester, followed by a deacetic acid polycondensation reaction.

Although this polycondensation reaction proceeds without a catalyst,
In some cases, it is preferable to add a metal compound such as stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, and metallic magnesium.

In the polycondensation of the liquid crystalline polyester which can be used in the present invention, 3,3'-diphenyldicarboxylic acid, 2,2'- Aromatic dicarboxylic acids such as diphenyldicarboxylic acid, adipic acid, azelaic acid, sebacic acid,
Aliphatic dicarboxylic acids such as dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, methylhydroquinone, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide, 4,4 ' -Aromatic diols such as dihydroxybenzophenone, 1,4-butanedio-
1,6-hexanediol-neopentyl glyco-
Aliphatic, alicyclic diol and aromatic hydroxy such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol. Carboxylic acid, p-aminophenol, p-aminobenzoic acid and the like can be further copolymerized in a small proportion that does not impair the object of the present invention.

The method of melt-kneading the liquid crystalline resin composition in the present invention is not particularly limited. For example, when melt-kneading a liquid crystalline polyester and a filler to form a resin composition,
It is recommended to use a twin-screw extruder, and to supply a liquid crystalline polyester and a filler to the extruder simultaneously or sequentially and continuously by melt kneading.

The filler used in the present invention is at least one selected from inorganic and / or organic fillers, additives, and other thermoplastic resins.

Examples of the inorganic and / or organic filler include glass fiber, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, stone fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber, and boron whisker fiber. , Mica, talc, silica, calcium carbonate,
Glass beads, glass flakes, glass microvalves
Fibrous, granular, powdery or plate-like inorganic and / or clays such as iron, clay, wollastenite, titanium oxide, graphite, etc.
Or an organic filler. In addition, the average fiber diameter of the glass fiber used in the present invention is preferably ³ to 15 μm, and the fiber length is preferably 30 to 10 ⁴ μm, more preferably 1000 μm.
４4000 μm. The glass fiber is preferably treated with a coating or sizing agent such as an epoxy-based, urethane-based, or acrylic-based material, and an epoxy-based material is particularly preferred.
It is preferably treated with a silane-based or titanate-based coupling agent or another surface treatment agent, and an epoxysilane or aminosilane-based coupling agent is particularly preferable.

Examples of the additives include an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphites and the like) and ultraviolet absorbers (for example, resorcinol, salicylate, benzotriazo). , Benzophenone, etc.), lubricants and release agents (such as montanic acid and its salts, esters thereof, half esters thereof, stearyl alcohol, stearamide and polyethylene wax), dyes (such as nigrosine) and pigments (such as sulfurized) Common additives such as a coloring agent containing cadmium, phthalocyanine, and carbon black), a plasticizer, an antistatic agent, and a flame retardant.

As the thermoplastic resin, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, poly-1,4
-Cyclohexane dimethylene terephthalate, polyamide, polycarbonate, polyacetal, polyphenylene sulfide, polyether terketone, polyetherimide, polyamideimide, polyether sulfone, polysulfone, polyoxymethylene, polyary Examples include ordinary thermoplastic resins such as lensulphide.

The filler used in the present invention is filled in an amount of 0 to 200 parts by weight in total with respect to 100 parts by weight of the liquid crystalline polyester. In order not to impair the excellent moldability and mechanical properties of the liquid crystalline polyester, The filling amount of the inorganic and / or organic filler is preferably 40 to 150 parts by weight,
More preferably, it is 50 to 100 parts by weight. Further, the filling amount of the additive is preferably 20 parts by weight or less, more preferably 10 parts by weight or less. The filling amount of the thermoplastic resin is preferably 100 parts by weight or less, more preferably 50 parts by weight.
Not more than parts by weight.

The molding liquid crystalline resin composition pellets obtained by the production method of the present invention can be used as a sensor, an LED lamp, a connector, a socket, a resistor, a relay, a switch, a coil, a coil bobbin, a capacitor, and a varicon. −
, Optical pickup, oscillator, various terminal boards, transformer plug, printed circuit board, tuner, speaker, microphone, headphone, small motor, magnetic head base
Electrical and electronic components such as power modules, power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders, parabolic antennas, computer related components, VTR components, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts,
Audio parts, audio / laser / compact disks, etc., audio equipment parts, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processors
Home and office electrical product parts such as parts, office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, cleaning jigs, motor parts, writers, and typewriters. , Optical equipment typified by microscopes, binoculars, cameras, clocks, etc., precision machinery-related parts, alternator terminals, alternator connectors, IC regulators ,
Potentiometer base for light dial, various valves such as exhaust gas valve, various valves related to fuel, exhaust system, intake system, air w-intake nozzle snorkel, intake manifold, fuel pump, engine cooling Water joint, carburetor main body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, brake padware sensor, throttle position sensor, crankshaft position sensor, air -Flow meter, brake pad wear sensor, thermostat base for air conditioner, heating hot air flow
Control valve, brush holder for radiator motor, water pump impeller, turbine bin, wiper motor related parts, distributor, starter switch, Starter relay, transmission wire harness, window washer
Nozzle, air conditioner panel switch board, fuel related solenoid valve coil, fuse connector, phone terminal,
Automotive / vehicle-related parts such as electrical parts insulation board, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil filter, ignition device case, etc. Useful for various applications.

A feature of the method for producing a liquid crystalline resin composition pellet for molding of the present invention is a pellet temperature at the time of pelletizing the composition obtained by the above polymerization reaction or melt kneading. That is, in the present invention, when cutting the polymer extruded from the discharge ports of the polymerization apparatus and the melt-kneading apparatus, it is to pelletize under the condition that the pellet temperature satisfies the following equation.

(Tm × 0.35) ≦ Pellet temperature ≦
(Tm × 0.55) Here, Tm in the formula represents the melting point (° C.) of the liquid crystalline resin composition.

The pellet temperature in the present invention refers to a pellet sampled immediately after pelletizing (within 10 seconds after cutting) in a 2 liter container having a heat retaining structure such as a thermos in which a temperature measuring part of a thermometer is installed. Is filled so as to be 80% of the internal volume, and the thermometer indicates a thermometer display value at the time when the temperature measuring unit comes into equilibrium with the pellet being in contact with the pellet.

If the pellet temperature is less than the above range, solidification causes cracking of the pellets during cutting, resulting in debris and
It is not preferable because it causes mixing of powder and irregular shapes. On the other hand, if the temperature is higher than the above range, the surface of the discharged polymer is weak, so that the pellets are fused or flattened, so that the object of the present invention cannot be achieved. The pellet temperature is within the above temperature range, more preferably Tm × 0.4 to Tm ×
Only when it is in the range of 0.5, it is possible to obtain a molding liquid crystalline resin composition pellet having a shape excellent in supplyability and quantitativeness in a high yield.

Further, the pelletization yield in the present invention is:
The ratio of the yield of pellets excluding non-standard-sized pellets to the amount of polymer extruded from the discharge ports of the polymerization apparatus and the melt-kneading apparatus.

The pelletizing method in the present invention is not particularly limited, and a known thermoplastic resin composition pellet manufacturing apparatus can be used. Examples thereof include a cold cut method, a hot cut method, and an under water cut method. , A cold cut method or a hot cut method is preferred.

Here, the melting point (Tm) is defined as Tm1 + 20 ° C. after observing the endothermic peak temperature (Tm1) observed when the temperature is measured at a rate of 20 ° C./min using a differential scanning calorimeter.
, And once cooled to room temperature under a temperature-lowering condition of 20 ° C./min, and the endothermic peak temperature (Tm2) observed when measured again at a temperature-raising condition of 20 ° C./min. Say.

[0038]

The present invention will be described in more detail with reference to the following examples.

Example 1 A reaction vessel of 0.1 m ³ equipped with a stirring blade and a distilling tube was charged with p-
Hydroxybenzoic acid 22.1 kg, 4,4'-dihydroxybiphenyl 2.8 kg, terephthalic acid 2.5 kg,
4.8 kg of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g and 21.7 kg of acetic anhydride were charged,
After reacting at 150 ° C. for 2 hours while stirring under a nitrogen atmosphere, the temperature was raised to 250 ° C. for 2.5 hours, and after holding for 1 hour, further raised to 320 ° C. for 1.5 hours. Then 1.
The pressure inside the reaction vessel was reduced to 1.0 mmHg in 5 hours, and the reaction was further continued for 1 hour to complete the polycondensation. Next, the inside of the reaction vessel was pressurized to 2.0 kg / cm ² , and the molten polymer at 320 ° C. was passed through a die having five circular discharge ports with a diameter of 6 mm.
Discharged in a strand at a linear velocity of 5 m / min,
After immersing in a water bath at 0 ° C for 2 seconds, strand cutter
(Tanabe Plastics Machine Co., Ltd.) 3mm in diameter,
Pelletized to a size of 3 mm in length. The melting point (Tm) of this liquid crystal polyester was 315 ° C. Table 1 shows the results of the pellet temperature, pelletization yield, and pellet shape measured by the method described above.

Example 2 A screw 44 mm in diameter equipped with a cylinder pressure reducing device
A screw extruder (manufactured by Nippon Steel Works, Ltd.) was charged with 100 parts by weight of the liquid crystal polyester obtained in the same manner as in Example 1 and a diameter of 13 μm.
m, 50 parts by weight of glass fiber having a length of 3 mm and 2 parts by weight of carbon black are continuously supplied at a total of 50 kg / hr, a cylinder temperature of 310 ° C., and a screw rotation speed of 20 parts.
After melt-kneading under the condition of 0 rpm, 330 ° C. is passed through a die in which seven circular discharge ports having a diameter of 4 mm are arranged in seven horizontal directions.
Is melted in a strand at a linear velocity of 20 m / min, passed through a water bath at a water temperature of 50 ° C. for 1.5 seconds, and then diameter 3 m with a strand cutter (manufactured by Ishinaka Tekko Co., Ltd.).
and pelletized to a size of 3 mm in length. Table 1 shows the results of the pellet temperature, pelletization yield, and pellet shape measured by the method described above.

Example 3 A screw 35 mm in diameter equipped with a cylinder pressure reducing device 2
A screw extruder (manufactured by Toshiba Machine Co., Ltd.) was charged with 100 parts by weight of the liquid crystal polyester obtained by the same method as in Example 1 and a diameter of 13 μm.
m, 100 parts by weight of glass fiber having a length of 3 mm, and 20 parts by weight of talc having an average particle diameter of 8 μm were continuously supplied at a total of 20 kg / hr, and were melt-kneaded at a cylinder temperature of 310 ° C. and a screw rotation speed of 200 rpm. After, 3m in diameter
The molten polymer at 340 ° C. is discharged at a linear velocity of 10 m / min via a die in which four circular discharge ports of m are arranged on the circumference, and the center-cut hot cutter is immediately used.
The pellets were pelletized into spherical pellets having a diameter of 3 mm using a Toshiba Machine Co., Ltd. Pellets are cooling water flowing along the inner wall of the cutter (water temperature 20 ° C, flow rate 100L / min)
Together with the water, and was separated from water by a dehydrator. Table 1 shows the results of the pellet temperature, pelletization yield, and pellet shape measured by the method described above.

Comparative Example 1 After the polycondensation reaction was completed under the same composition and under the same conditions as in Example 1, pelletizing was performed under the same conditions as in Example 1 except that the immersion time in the water bath was changed to 4 seconds. Table 1 shows the results.

Comparative Example 2 After the polycondensation reaction was completed under the same composition and under the same conditions as in Example 1, the pelletizing was performed under the same conditions as in Example 1 except that the immersion time in the water bath was changed to 0.5 second. Table 1 shows the results.

Comparative Example 3 After melt-kneading under the same composition and under the same conditions as in Example 2, the pelletizing was carried out under the same conditions as in Example 2 except that the water temperature of the water bath through which the discharge strand was passed was 20 ° C. Table 1 shows the results.

Comparative Example 4 Example 3 was repeated except that the temperature of the cooling water in the cutter cover was changed to 50 ° C. after melt-kneading under the same composition and under the same conditions as in Example 3.
Pelletized under the same conditions. Table 1 shows the results.

[0046]

[Table 1] As is clear from Table 1, the liquid crystalline resin composition pellets for molding obtained by the production method of the present invention have a higher yield and a uniform shape as compared with the pellets obtained by the method shown in Comparative Example. I have.

[0047]

Industrial Applicability According to the present invention, it is possible to produce a molding liquid crystalline resin composition pellet having a shape excellent in supplyability and quantitativeness in a high yield.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08J 3/12 B29B 9/06 B29B 9/12-9/14

Claims (3)

(57) [Claims] (1) The following (I), (II), (IV) or (I), (III), (IV) or (I), (II),
One or more fillers 0 to 0 selected from inorganic and / or organic fillers, additives, and other thermoplastic resins with respect to 100 parts by weight of the liquid crystalline polyester comprising the structural units (III) and (IV). A liquid crystalline resin composition for molding, characterized in that when producing a pellet of the liquid crystalline resin composition for molding filled with 200 parts by weight, the pellet temperature during cutting satisfies the following equation: Of manufacturing product pellets. (Tm × 0.35) ≦ pellet temperature ≦ (Tm × 0.55) Here, Tm in the formula represents the melting point (° C.) of the liquid crystalline resin composition. Embedded image (Where R ₁ in the formula is And R ₂ represents one or more groups selected from Represents one or more groups selected from In the formula, X represents a hydrogen atom or a chlorine atom, and the structural units (II) and (II)
The sum of I) and the structural units (IV) are substantially equimolar) 2. The method according to claim 1, wherein the liquid crystalline polyester is (I), (II), (IV) or (I), (II),
The method for producing a molding liquid crystalline resin composition pellet according to claim 1, comprising a structural unit of (III) or (IV). 3. The liquid crystalline resin composition pellet according to claim 1, wherein the liquid crystalline polyester comprises the structural units of (I), (II), (III), and (IV). Manufacturing method.