JP2013199598A - Method for producing liquid crystal polyester composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit contamination due to foreign matter when producing a liquid crystal polyester composition containing liquid crystal polyester and a fatty acid ester of pentaerythritol using an extruder.SOLUTION: A liquid crystal polyester composition comprising 100 pts.mass liquid crystal polyester and 0.1-1 pts.mass fatty acid ester of pentaerythritol is produced using an extruder 2 in which a vacuum vent 23 having a vent port 32 is established on a barrel 25D. With the vent port 32 heated to 250°C or higher, the liquid crystal polyester and the fatty acid ester of pentaerythritol are melted and kneaded in the barrel 25D. A decomposed gas is hardly deposited which is produced through melting and kneading of the liquid crystal polyester and the fatty acid ester of pentaerythritol, onto an inner wall of the vent port 32.

Description

  The present invention relates to a method for producing a liquid crystal polyester composition containing a liquid crystal polyester and a fatty acid ester of pentaerythritol.

  2. Description of the Related Art Conventionally, liquid crystal polyester compositions containing liquid crystal polyester and a fatty acid ester of pentaerythritol have been used for thin-walled / small-sized injection-molded articles because of their high releasability. And it is disclosed that such a liquid crystal polyester composition is manufactured using an extruder (for example, refer to Patent Documents 1 and 2).

JP-A-2-208353 JP 2009-179893 A

  However, when a liquid crystal polyester composition containing a liquid crystal polyester and a fatty acid ester of pentaerythritol is produced by an extruder, a cracked gas is generated in the barrel of the extruder along with the melt kneading of the liquid crystal polyester and the fatty acid ester of pentaerythritol. Will occur. And this decomposition gas condenses in the vent port part of an extruder, adheres to an inner wall, it deteriorates, it may fall to a barrel, and there exists a possibility of mixing with a liquid crystal polyester composition as a foreign material.

  Therefore, in view of such circumstances, the present invention suppresses the mixing of foreign matters into the liquid crystal polyester composition when the liquid crystal polyester composition containing the liquid crystal polyester and the fatty acid ester of pentaerythritol is produced with an extruder. It is an object of the present invention to provide a method for producing a liquid crystal polyester composition that can be used.

  In order to achieve this object, the present inventor has intensively studied, and as a result, has completed the present invention.

  That is, the invention of the “method for producing a liquid crystal polyester composition” according to claim 1 uses an extruder in which a vent portion having a vent port portion is provided in a barrel, and 100 parts by mass of liquid crystal polyester is subjected to pentaerythritol. A method for producing a liquid crystal polyester composition comprising 0.1 to 1 part by weight of a fatty acid ester, wherein the liquid crystal polyester and the pentaerythritol are heated inside the barrel while the vent port portion is heated to 250 ° C. or higher. The fatty acid ester is melt-kneaded.

  According to the present invention, the liquid crystal polyester and the fatty acid ester of pentaerythritol are melted and kneaded inside the barrel while the vent port portion is heated to 250 ° C. or higher, so that the liquid crystal polyester and the fatty acid ester of pentaerythritol are melt-kneaded. Along with this, the generated decomposition gas is difficult to adhere to the inner wall of the vent port portion. As a result, when a liquid crystal polyester composition containing the liquid crystal polyester and a fatty acid ester of pentaerythritol is produced with an extruder, it is possible to suppress the entry of foreign matter into the liquid crystal polyester composition.

It is a front view which shows roughly the resin manufacturing equipment which concerns on Embodiment 1 of this invention. It is a front view which shows the extruder of the resin manufacturing equipment shown in FIG. It is an expanded sectional view which shows the principal part of the extruder shown in FIG.

Embodiments of the present invention will be described below.
Embodiment 1 of the Invention

1 to 3 show a first embodiment of the present invention.
<Configuration of resin production equipment>

As shown in FIG. 1, the resin manufacturing facility 1 according to the first embodiment includes an extruder 2. This extruder 2 has an extruder main body 21, and an open vent 22 and a vacuum vent 23 are attached to the extruder main body 21 as two vent portions. The details of the extruder 2 will be described later. A cylindrical tank 3 having a capacity of 10 L is installed in the vicinity of the extruder 2, and a pipe 4 is installed between the vacuum vent 23 and the tank 3 of the extruder 2. Further, a vacuum pump 6 is connected to the tank 3 via a pipe 5. Then, by driving the vacuum pump 6, as described later, the decomposition gas generated when the liquid crystal polyester and the fatty acid ester of pentaerythritol are melted and kneaded by the extruder 2 is condensed and recovered in the tank 3 while being vacuumed. The inside of the vent 23 can be evacuated.
<Extruder configuration>

  As shown in FIG. 2, the extruder 2 has an extruder body 21, and the extruder body 21 includes a drive unit 24 including a gear box and a motor, and the front of the drive unit 24 (left side in FIG. 2). And 12 barrels 25 connected in series on a straight line.

  A supply port 26 for supplying main raw materials such as liquid crystal polyester and fatty acid ester of pentaerythritol is mounted on the upper surface of the first barrel 25A, and on the upper surface of the sixth barrel 25B, An open vent 22 is attached. A supply port 27 for supplying auxiliary materials such as fillers and additives is mounted on the side surface of the seventh barrel 25C, and a vacuum vent 23 is provided on the upper surface of the eleventh barrel 25D. Is attached.

  That is, inside the eleventh barrel 25D, as shown in FIG. 3, two screws 28 penetrating all twelve barrels 25 in the horizontal direction are rotatably installed by the drive unit 24. An opening 29 that communicates the inside and outside of the barrel 25D is formed at the top of the eleventh barrel 25D. A vacuum vent 23 is provided above the eleventh barrel 25D. The vacuum vent 23 includes a vent block 31 for preventing a vent-up phenomenon in which molten kneaded material (resin) leaks from the opening 29, a vent port part 32 communicating with the opening 29, and the vent port part 32. The heater 33 for heating from the outside and the temperature sensor 34 attached to the outer wall of the vent port part 32 are comprised. Further, the vent port portion 32 includes a box-shaped vent port main body 32a and a vent port lid 32b detachably attached to the upper side of the vent port main body 32a. A pipe 4 is installed in the vacuum vent 23 so as to communicate with the inside of the vent port section 32, and a ribbon heater 35 for heating the pipe 4 from the outside is attached to the outer periphery of the pipe 4. It has been. Further, a temperature sensor 36 is attached to the outer wall of the pipe 4.

  An open vent 22 is provided on the upper side of the sixth barrel 25B. In this open vent 22, the vent port portion 32 is configured only from the vent port main body 32 a (the vent port lid 32 b is not provided), and the heater 33 is configured to heat only the vent port main body 32 a. Except for the point and the point where the pipe 4, the ribbon heater 35, and the temperature sensor 36 are not attached, it has the same configuration as the vacuum vent 23 described above.

Further, a die 30 is attached in front of the twelfth barrel 25E (left side in FIG. 2), and the die 30 includes two die heads 30a and a die nozzle 30b.
<Liquid crystal polyester composition>

  The liquid crystalline polyester composition of the present invention is a composition in which 0.1 to 1 part by mass of a fatty acid ester of pentaerythritol is contained in 100 parts by mass of the liquid crystalline polyester.

  The liquid crystalline polyester is a polyester that exhibits liquid crystallinity in a molten state, and is preferably melted at a temperature of 450 ° C. or lower. The liquid crystal polyester may be a liquid crystal polyester amide, a liquid crystal polyester ether, a liquid crystal polyester carbonate, or a liquid crystal polyester imide. The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester using only an aromatic compound as a raw material monomer.

  As a typical example of the liquid crystal polyester, an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxyamine, and an aromatic diamine are polymerized ( At least one selected from the group consisting of polycondensation), polymerization of multiple types of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines and aromatic diamines And those obtained by polymerizing a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid. Here, the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, the aromatic diol, the aromatic hydroxyamine, and the aromatic diamine are each independently replaced with a part or all of the polymerizable derivative. Also good.

  Examples of polymerizable derivatives of compounds having a carboxyl group such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid include those obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl Examples include those obtained by converting a group into a haloformyl group (acid halide), and those obtained by converting a carboxyl group into an acyloxycarbonyl group (acid anhydride). Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines include those obtained by acylating hydroxyl groups and converting them to acyloxyl groups (acylated products) ). Examples of polymerizable derivatives of amino group-containing compounds such as aromatic hydroxyamines and aromatic diamines include those obtained by acylating an amino group and converting it to an acylamino group (acylated product).

The liquid crystalline polyester preferably has a repeating unit represented by the following formula (1) (hereinafter sometimes referred to as “repeating unit (1)”), and the repeating unit (1) and the following formula (2) A repeating unit represented (hereinafter sometimes referred to as “repeating unit (2)”) and a repeating unit represented by the following formula (3) (hereinafter sometimes referred to as “repeating unit (3)”). It is more preferable to have.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
⁽³⁾ -X-Ar 3 -Y-
(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and the hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or an alkyl group. Or it may be substituted with an aryl group.)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ and Ar ⁵ each independently represents a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, An n-octyl group and n-decyl group are mentioned, The carbon number is 1-10 normally. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group, and the carbon number thereof is usually 6-20. . When the hydrogen atom is substituted with these groups, the number thereof is usually 2 or less for each group represented by Ar ¹ , Ar ² or Ar ³ , and preferably 1 It is as follows.

  Examples of the alkylidene group include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group, and a 2-ethylhexylidene group, and the number of carbon atoms is usually 1 to 10.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As the repeating unit (1), Ar ¹ is a p-phenylene group (a repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ is a 2,6-naphthylene group (6-hydroxy-2). -Repeating units derived from naphthoic acid) are preferred.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a p-phenylene group (repeating unit derived from terephthalic acid), Ar ² is an m-phenylene group (repeating unit derived from isophthalic acid), Ar ² Is a 2,6-naphthylene group (repeating unit derived from 2,6-naphthalenedicarboxylic acid), and Ar ² is a diphenyl ether-4,4′-diyl group (diphenyl ether- 4,4′-dicarboxylic acid-derived repeating units) are preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. As the repeating unit (3), Ar ³ is a p-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4′-biphenylylene group. Those (4,4′-dihydroxybiphenyl, 4-amino-4′-hydroxybiphenyl or repeating units derived from 4,4′-diaminobiphenyl) are preferred.

  The content of the repeating unit (1) is the total amount of all repeating units (the mass equivalent amount of each repeating unit (moles by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula amount of each repeating unit). ) And the total value thereof) is usually 30 mol% or more, preferably 30 to 80 mol%, more preferably 40 to 70 mol%, still more preferably 45 to 65 mol%. The content of the repeating unit (2) is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 30 mol%, still more preferably 17.5 to the total amount of all repeating units. 27.5 mol%. The content of the repeating unit (3) is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 15 to 30 mol%, still more preferably 17.5 to the total amount of all repeating units. 27.5 mol%. The higher the content of the repeating unit (1), the easier it is to improve the melt fluidity, heat resistance, strength, and rigidity. However, if the content is too large, the melting temperature and viscosity tend to increase, and the temperature required for molding increases. Cheap.

  The ratio between the content of the repeating unit (2) and the content of the repeating unit (3) is expressed as [content of repeating unit (2)] / [content of repeating unit (3)] (mol / mol). The ratio is usually 0.9 / 1 to 1 / 0.9, preferably 0.95 / 1 to 1 / 0.95, and more preferably 0.98 / 1 to 1 / 0.98.

  In addition, liquid crystalline polyester may have 2 or more types of repeating units (1)-(3) each independently. Further, the liquid crystalline polyester may have a repeating unit other than the repeating units (1) to (3), but the content thereof is usually 10 mol% or less with respect to the total amount of all repeating units, preferably 5 mol% or less.

  Since the liquid crystal polyester has a repeating unit (3) in which X and Y are each an oxygen atom, that is, having a repeating unit derived from a predetermined aromatic diol, the melt viscosity tends to be low. It is preferable that the repeating unit (3) has only those in which X and Y are each an oxygen atom.

  The liquid crystalline polyester can be produced by melt polymerizing raw material monomers corresponding to the repeating units constituting the liquid crystalline polyester and solid-phase polymerizing the obtained polymer (hereinafter sometimes referred to as “prepolymer”). preferable. Thereby, high molecular weight liquid crystal polyester having high heat resistance, strength and rigidity can be produced with good operability. Melt polymerization may be carried out in the presence of a catalyst. Examples of this catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, And nitrogen-containing heterocyclic compounds such as 4- (dimethylamino) pyridine and 1-methylimidazole, and nitrogen-containing heterocyclic compounds are preferably used.

  The liquid polyester has a flow starting temperature of usually 270 ° C. or higher, preferably 270 to 400 ° C., more preferably 280 to 380 ° C. As the flow start temperature is higher, the heat resistance, strength and rigidity are more likely to be improved. However, if the flow start temperature is too high, the melting temperature and the melt viscosity are likely to be high, and the temperature required for the molding is likely to be high.

The flow start temperature is also referred to as flow temperature or flow temperature. The liquid crystal polyester is heated at a rate of 4 ° C./min under a load of 9.8 MPa (100 kg / cm ² ) using a capillary rheometer. Is a temperature showing a viscosity of 4800 Pa · s (48000 poise) when extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm, and is a measure of the molecular weight of the liquid crystalline polyester (for example, Naoyuki Koide) "Refer to" Liquid Crystal Polymer -Synthesis / Molding / Application- ", pages 95-105, CMC Publishing Co., Ltd., published on June 5, 1987).

  On the other hand, the fatty acid ester of pentaerythritol is preferably any one of fatty acid monoesters, diesters, triesters and tetraesters of pentaerythritol, or a mixture thereof. The fatty acid ester of pentaerythritol may be a multimer.

  As fatty acids, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, Icosanoic acid, docosanoic acid (behenic acid), tetradocosanoic acid, hexadocosanoic acid, octadocosanoic acid (montanic acid), octadocosanoic acid and the like are preferred, octadecanoic acid, docosanoic acid, octadocosanoic acid and the like are more preferred, and octadecanoic acid is particularly preferred.

  In addition, the liquid crystal polyester composition may contain one or more other components such as a filler, an additive, and a resin other than the liquid crystal polyester.

  The filler may be a fibrous filler, a plate-like filler, or a spherical or other granular filler other than the fibrous and plate-like materials. The filler may be an inorganic filler or an organic filler. Examples of fibrous inorganic fillers include glass fibers; carbon fibers such as pan-based carbon fibers and pitch-based carbon fibers; ceramic fibers such as silica fibers, alumina fibers and silica-alumina fibers; and metal fibers such as stainless steel fibers. It is done. In addition, whiskers such as potassium titanate whisker, barium titanate whisker, wollastonite whisker, aluminum borate whisker, silicon nitride whisker, and silicon carbide whisker are also included. Examples of fibrous organic fillers include polyester fibers and aramid fibers. Examples of the plate-like inorganic filler include talc, mica, graphite, wollastonite, glass flake, barium sulfate and calcium carbonate. Mica may be muscovite, phlogopite, fluorine phlogopite, or tetrasilicon mica. Examples of the particulate inorganic filler include silica, alumina, titanium oxide, glass beads, glass balloons, boron nitride, silicon carbide and calcium carbonate. Content of a filler is 0-100 mass parts normally with respect to 100 mass parts of liquid crystalline polyester.

  Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants and colorants. Content of an additive is 0-5 mass parts normally with respect to 100 mass parts of liquid crystalline polyester.

Examples of resins other than liquid crystal polyesters include polypropylene, polyamide, polyesters other than liquid crystal polyesters, thermoplastic resins other than liquid crystal polyesters such as polysulfone, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyetherimide; and phenol resins And thermosetting resins such as epoxy resins, polyimide resins, and cyanate resins. Content of resin other than liquid crystalline polyester is 0-20 mass parts normally with respect to 100 mass parts of liquid crystalline polyester.
<Method for producing liquid crystal polyester composition>

  When this liquid crystal polyester composition is produced, the liquid crystal polyester and the fatty acid ester of pentaerythritol are melt-kneaded in the extruder 2 by the following procedure. Examples of the extruder 2 include a single-screw extruder and a twin-screw extruder having one or a plurality of vent portions, and the twin-screw extruder has a single-thread screw to a triple-screw screw rotating in the same direction. Can be used, and may be a parallel shaft type, an oblique shaft type, or an incomplete meshing type rotating in different directions. Among these, a twin-screw extruder rotating in the same direction having one or more vent portions is preferable. The screw diameter of the extruder 2 should just be 20 mm or more, According to the quantity which manufactures a liquid-crystal polyester composition, various sizes can be used. The temperature for melt kneading is preferably 250 ° C. or higher and 450 ° C. or lower, and more preferably 300 ° C. or higher and 400 ° C. or lower.

  First, in the vent port heating step, by energizing the heater 33 in the vacuum vent 23, the vent port portion 32 is heated to 250 ° C. or higher and the temperature is maintained. At this time, since the temperature sensor 34 is attached to the outer wall of the vent port portion 32, the temperature of the vent port portion 32 can be easily maintained by performing feedback control based on the output of the temperature sensor 34. Further, by energizing the ribbon heater 35, the pipe 4 is heated to a predetermined temperature and the temperature is maintained. As temperature of this piping 4, 100 to 450 degreeC is preferable and 150 to 400 degreeC is more preferable. At this time, since the temperature sensor 36 is attached to the outer wall of the pipe 4, the temperature of the pipe 4 can be easily maintained by performing feedback control based on the output of the temperature sensor 36. Similarly, by energizing the heater 33 in the open vent 22, the vent port portion 32 is heated to 250 ° C. or higher and the temperature is maintained. At this time, since the temperature sensor 34 is attached to the outer wall of the vent port portion 32, the temperature of the vent port portion 32 can be easily maintained by performing feedback control based on the output of the temperature sensor 34.

  Next, the process goes to a vacuuming step, and the vacuum pump 6 is driven to evacuate the vacuum vent 23.

  In this state, the process proceeds to the screw driving step, and the two screws 28 are rotated by the driving unit 24.

  Subsequently, the process proceeds to a main raw material supply step, and main raw materials (liquid crystal polyester, pentaerythritol fatty acid ester, etc.) of the liquid crystal polyester composition are supplied from the supply port 26.

  Finally, the process proceeds to the auxiliary material supply step, and auxiliary materials (fillers, additives, etc.) of the liquid crystal polyester composition are supplied from the supply port 27.

  Then, by rotation of the screw 28, the liquid crystal polyester and the fatty acid ester of pentaerythritol are supplied to the front (left side in FIG. 2) while being melt-kneaded inside the barrel 25, and in the seventh barrel 25C, the filler or Additives and the like are added and finally extruded from the die 30 in the form of pellets.

  At this time, a cracked gas is generated in the barrel 25 as the liquid crystal polyester and the fatty acid ester of pentaerythritol are melt-kneaded.

  However, in the extruder 2, as described above, in the vacuum vent 23 and the open vent 22, the vent port portion 32 is heated to 250 ° C. or higher, so that the liquid crystal polyester and the fatty acid ester of pentaerythritol Decomposed gas generated by melt kneading is less likely to adhere to the inner wall of the vent port portion 32. As a result, when the liquid crystal polyester composition containing the liquid crystal polyester and the fatty acid ester of pentaerythritol is produced by the extruder 2, it becomes possible to suppress the mixing of foreign matters into the liquid crystal polyester composition.

  In addition, since the pipe 4 is heated to a predetermined temperature as described above, the decomposition gas does not condense in the pipe 4 and adhere to the inner wall of the pipe 4. Therefore, by avoiding the blockage of the pipe 4, it is possible to continue the evacuation work in the vacuum vent 23 without any trouble.

  Furthermore, when the vacuum pump 6 is driven and the inside of the vacuum vent 23 is evacuated, the cracked gas generated when the liquid crystal polyester and the fatty acid ester of pentaerythritol are melted and kneaded by the extruder 2 in the tank 3 as described above. It can be recovered. Therefore, it is possible to maintain the degree of vacuum in the vacuum vent 23 and to prevent the vacuum pump 6 from being broken due to the cracked gas.

  In addition, as a molding method of the liquid crystal polyester composition, a melt molding method is preferable. Examples thereof include an injection molding method, an extrusion molding method such as a T-die method and an inflation method, a compression molding method, a blow molding method, and a vacuum molding method. And press molding. Of these, the injection molding method is preferable.

Examples of products and parts that are molded products of liquid crystal polyester compositions include bobbins such as optical pickup bobbins and transbobbins; relay parts such as relay cases, relay bases, relay sprues, and relay armatures; RIMM, DDR, CPU socket , S / O, DIMM, Board to Board connector, FPC connector, card connector, etc .; Lamp reflector, LED reflector, etc .; Lamp holder, heater holder, etc .; Speaker diaphragm, etc. Separation claws, separation claws for printers, etc .; camera module parts; switch parts; motor parts; sensor parts; hard disk drive parts; tableware such as ovenware; Include the sealing member of the sealing member such as a coil.
[Other Embodiments of the Invention]

  In the first embodiment described above, the case where the vacuum pump 6 is used as a vacuum device for evacuating the inside of the vacuum vent 23 has been described. However, a vacuum device other than the vacuum pump 6 can be used instead or in combination.

  In the first embodiment described above, the heater 33 is used as the heating means for heating the vent port portion 32 and the ribbon heater 35 is used as the heating means for heating the pipe 4. Thus, when the heater 33 and the ribbon heater 35 are used, there exists an advantage that it is excellent in operativity. However, as long as the vent port portion 32 and the pipe 4 can be heated to a predetermined temperature, for example, a lamp and a heat medium (steam, hot water, hot air, oil, etc.) can be substituted or used together.

  Moreover, in Embodiment 1 mentioned above, the extruder 2 in which the open vent 22 and the vacuum vent 23 were provided one place each as a vent part was demonstrated. However, you may provide the open vent 22 and the vacuum vent 23 in multiple places (two or more places). In addition, when a vent part is provided in several places, there may exist a vent part with little adhesion of the decomposition gas to the vent port part 32. FIG. In this case, it is possible to heat only the vent portion where the decomposition gas adheres to the vent port portion 32 and not to heat the vent portion where the decomposition gas adheres little to the vent port portion 32.

  In the first embodiment described above, the extruder 2 in which the open vent 22 is attached to the upper surface of the sixth barrel 25B and the vacuum vent 23 is attached to the upper surface of the eleventh barrel 25D has been described. However, the open vent 22 may be attached to the side surface of the barrel 25B, or the vacuum vent 23 may be attached to the side surface of the barrel 25D.

  Moreover, in Embodiment 1 mentioned above, although the case where the auxiliary materials (filler, additive, etc.) of a liquid crystal polyester composition were supplied from the supply port 27 was demonstrated, naturally supply of this auxiliary material can also be omitted.

Examples of the present invention will be described below. In addition, this invention is not limited to an Example.
<Measurement of flow start temperature of liquid crystal polyester>

Using a flow characteristic evaluation apparatus “Flow Tester CFT-500 type” manufactured by Shimadzu Corporation, about 2 g of liquid crystal polyester was filled in a barrel attached with a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm, and 9.8 MPa. While the temperature is raised at a rate of 4 ° C./min under a load of (100 kgf / cm ² ), the liquid crystal polyester is melted and extruded from the nozzle, and the temperature at which the melt viscosity is 4800 Pa · s (48000 poise) is defined as the flow start temperature. did.
<Production of liquid crystal polyester 1>

In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid and 299.0 g (1.8 mol) of terephthalic acid , 99.7 g (0.6 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4′-dihydroxybiphenyl, 1347.6 g (13.2 mol) of acetic anhydride and 0.18 g of 1-methylimidazole The mixture was heated from room temperature to 150 ° C. over 30 minutes with stirring under a nitrogen gas stream, and refluxed at 150 ° C. for 0.5 hours. Subsequently, 2.4 g of 1-methylimidazole was added, and while raising by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 150 ° C. to 320 ° C. over 3 hours, and kept at 320 ° C. for 1.5 hours. The contents were then removed from the reactor and cooled to room temperature. The obtained solid was pulverized with a pulverizer to obtain a powdered prepolymer. The flow initiation temperature of this prepolymer was 261 ° C. Next, the prepolymer was heated from room temperature to 250 ° C. over 1 hour in a nitrogen gas atmosphere, heated from 250 ° C. to 295 ° C. over 5 hours, and kept at 295 ° C. for 3 hours, thereby solidifying the prepolymer. After the phase polymerization, the mixture was cooled to obtain a powdery liquid crystal polyester. The liquid crystal polyester had a flow initiation temperature of 327 ° C. This liquid crystal polyester is designated as LCP1.
<Production of liquid crystal polyester 2>

In a reactor equipped with a stirrer, a torque meter, a nitrogen gas introduction tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid and 239.2 g (1.44 mol) of terephthalic acid , 159.5 g (0.96 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4′-dihydroxybiphenyl, 1347.6 g (13.2 mol) of acetic anhydride and 0.18 g of 1-methylimidazole The mixture was heated from room temperature to 150 ° C. over 30 minutes with stirring under a nitrogen gas stream, and refluxed at 150 ° C. for 0.5 hours. Subsequently, 2.4 g of 1-methylimidazole was added, and while raising by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 150 ° C. to 320 ° C. over 3 hours, and kept at 320 ° C. for 1.5 hours. The contents were then removed from the reactor and cooled to room temperature. The obtained solid was pulverized with a pulverizer to obtain a powdered prepolymer. The flow initiation temperature of this prepolymer was 243 ° C. Next, the prepolymer was heated from room temperature to 220 ° C. over 1 hour in a nitrogen gas atmosphere, heated from 220 ° C. to 240 ° C. over 0.5 hour, and held at 240 ° C. for 10 hours. After solid phase polymerization, the mixture was cooled to obtain a powdery liquid crystal polyester. The liquid crystal polyester had a flow start temperature of 286 ° C. This liquid crystal polyester is referred to as LCP2.
<Extruder>

  This embodiment consists of twelve barrels, the first barrel has a supply port, the sixth barrel has an open vent, the eleventh barrel has a vacuum vent, and has a screw diameter of 30 mm in the same direction. A rotary twin screw extruder PCM30HS (manufactured by Ikegai Co., Ltd.) was used. Of the 12 blocks, a side feeder was connected as a second supply port to the seventh barrel counted from the drive side of the extruder so that the filler could be supplied.

In the extruder, a temperature sensor and a heater were installed on the outer wall of each vent port portion of the open vent and the vacuum vent. A 10 L cylindrical tank was provided between the vacuum vent and the vacuum pump, and pipes connecting the vacuum vent and the tank and the tank and the vacuum pump were connected to the upper surface of the tank. A ribbon heater and a temperature sensor were installed in the piping between the vacuum vent and the tank.
<Example 1>

In the above extruder, the vent port portion of the open vent and the vacuum vent was heated to 300 ° C, and the piping between the vacuum vent and the tank was heated to 250 ° C. A raw material mixed at a ratio of LCP1 / LCP2 / pentaerythritol fatty acid ester = 55/45 / 0.045 was quantitatively supplied at a rate of 13.00 kg / h from the raw material supply section provided in the first barrel. Dipentaerythritol hexastearate (sold by Emery Oleochemicals Japan Co., Ltd., trade name LOXIOL VPG2571) was used as the fatty acid ester of pentaerythritol. From the side feeder, chopped strand glass fibers (Owens Corning Japan Co., Ltd., trade name CS03JAPx-1) were quantitatively supplied at a rate of 4.40 kg / h. Similarly, talc (manufactured by Nippon Talc Co., Ltd., trade name X-50) was quantitatively supplied from the side feeder at a rate of 2.60 kg / h. Melting and kneading was performed at a barrel set temperature of 340 ° C. and a screw rotation speed of 200 times / minute, and the state of the vent port portion of the open vent and the vacuum vent after the liquid crystal polyester composition was produced for 8 hours was observed. As a result, no condensate or deposits adhered to the vent ports of the open vent and the vacuum vent, and the generated gas was slightly adhered to the surface and colored.
<Comparative Example 1>

  In the above extruder, the liquid crystal polyester composition was prepared by the method described in Example 1 except that the vent port part of the open vent and the vacuum vent was heated to 200 ° C. and the piping between the vacuum vent and the tank was heated to 150 ° C. Manufactured on time. As a result of observing the state of the vent port part of the open vent and the vacuum vent after the production, it was found that a brown to black deposit adhered to both the vent port parts, and the deposit was mixed in the liquid crystal polyester composition. Probable traces were confirmed. Moreover, when the obtained liquid crystal polyester composition was visually observed, adhesion of black spots was observed on some pellets.

2 …… Extruder 22 …… Open vent (vent part)
23 …… Vacuum vent (vent part)
25 …… Barrel 32 …… Vent port

Claims (1)

By using an extruder in which a vent part having a vent port part is provided in a barrel, a method for producing a liquid crystal polyester composition in which 100 parts by mass of a liquid crystal polyester contains 0.1 to 1 part by mass of a fatty acid ester of pentaerythritol. There,
A method for producing a liquid crystal polyester composition, comprising melting and kneading the liquid crystal polyester and the fatty acid ester of pentaerythritol inside the barrel while the vent port portion is heated to 250 ° C. or more.

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