JP2001277238A - Manufacturing method for liquid crystal resin pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a liquid crystal resin pellet of which the discharge-stability is increased. SOLUTION: A liquid crystal resin under a molten state is discharged in a trough wherein cooling water is made to flow, by a discharging device as a strand group. Then, the strand group is solidified by cooling, and cut under the existence of the cooling water for this manufacturing method for pellets. In this manufacturing method, at least in the discharge initial stage from when the strand group is discharged from the discharging device to when the strand group reaches a cutter section, an amount of the cooling water, which is from 1.1 times to 10 times based on the amount of the cooling water at the normal pellet-forming time is made to flow into the trough.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing liquid crystalline resin pellets, and more particularly to a method for producing liquid crystalline resin pellets having improved discharge stability.

[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, a polymer is characterized by a parallel arrangement of molecular chains. Optically anisotropic liquid crystalline resins have attracted attention because of their excellent fluidity and mechanical properties.

As such a liquid crystalline resin, particularly a liquid crystalline polyester resin, a liquid crystalline polyester resin obtained by copolymerizing p-hydroxybenzoic acid and polyethylene terephthalate (JP-B-56-18016), p-hydroxybenzoic acid and In addition to polyethylene terephthalate,
A liquid crystalline polyester resin having improved flowability and heat resistance by adding an aromatic diol such as 4′-dihydroxybiphenyl and a copolymerization component such as an aromatic dicarboxylic acid (JP-A-63-30523); Liquid crystalline polyester resin obtained by copolymerizing hydroxybenzoic acid with 4,4'-dihydroxybiphenyl, t-butylhydroquinone and terephthalic acid (JP-A-62-164719), p-
Liquid crystalline polyester resin obtained by copolymerizing hydroxybenzoic acid with 4,4'-dihydroxybiphenyl, isophthalic acid and terephthalic acid (JP-B-57-24407, JP-A-60-25046), and p-hydroxybenzoic acid And a liquid crystalline polyester resin obtained by copolymerizing 6-hydroxy-2-naphthoic acid (Japanese Patent Application Laid-Open No. 54-77691).

As a method for producing these liquid crystalline polyester resins, as disclosed in Japanese Patent Application Laid-Open No. 6-192404, a hydroxyl group in a raw material monomer is subjected to an acetylation reaction with acetic anhydride, followed by dehydration. A method of performing an acetic acid polycondensation reaction is known.

On the other hand, as a method for producing thermoplastic resin pellets, a molten polymer is extruded into a strand shape through a die provided at a discharge outlet, cooled through a water bath, solidified, and then cut into pellets. The method (cold cut method) is most commonly used.

Further, as a method for further improving the yield of pellets in the above method, there is known a method in which a molten polymer is flowed in a strand form in a trough and cut in the presence of cooling water. For this method,
Specifically, it is disclosed in Japanese Patent Application Laid-Open No. H10-180753. However, when a liquid crystalline resin is applied to this, the strand group discharged from the discharge device reaches the cutter unit before it reaches the cutter unit. Due to poor flow, the fluid stays on the trough, causing a problem that ejection is not performed normally, and there is a problem that ejection stability is deteriorated.

[0007]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of studying to solve the problems in the prior art described above.

Accordingly, an object of the present invention is to provide a method for producing liquid crystalline resin pellets having improved ejection stability.

[0009]

In order to achieve the above object, a method of manufacturing a liquid crystalline resin pellet according to the present invention is directed to a method for manufacturing a liquid crystalline resin pellet in a molten state by using a trough having cooling water flowing through a discharge device. A pellet group that is discharged into a strand group, cooled and solidified, and cut in the presence of the cooling water, wherein the strand group is discharged from at least the discharge device. It is characterized in that a cooling water amount of 1.1 to 10 times the cooling water amount at the time of steady pelletization flows in the trough at the initial stage of discharge until the group reaches the cutter portion.

In the method for producing liquid crystalline resin pellets of the present invention, the following conditions (a) to (c) are preferable conditions.

(A) The trough has a downward slope from the vicinity of the discharge section toward the cutter section, and the trough angle is greater than 0 degrees and 30 degrees or less with respect to a horizontal axis.

(B) The liquid crystalline resin is a liquid crystalline polyester containing a structural unit composed of p-hydroxybenzoic acid as an essential component.

(C) the liquid crystalline resin is a liquid crystalline polyester comprising the following structural units (I), a liquid crystalline polyester comprising the following structural units (I), (II) and (IV):
Liquid crystalline polyester comprising the following structural units (I), (III) and (IV), and the following structural units (I), (II) and (II)
At least one selected from liquid crystalline polyesters comprising I) and (IV) and liquid crystalline polyesteramides containing a structural unit comprising an aromatic aminohydroxy compound and / or an aromatic aminocarboxylic acid in these liquid crystalline polyesters That.

[0014]

Embedded image (However, R ₁ in the above formula is

[0015]

Embedded image R ₂ represents one or more groups selected from

[0016]

Embedded image R ₃ represents one or more groups selected from

[0017]

Embedded image Represents one or more groups selected from X in the formula represents a hydrogen atom or a chlorine atom. )

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a liquid crystalline resin pellet of the present invention will be described in detail.

The liquid crystalline resin produced in the present invention is a resin capable of forming an anisotropic molten phase upon melting, and examples thereof include liquid crystalline polyester, liquid crystalline polyester amide, liquid crystalline polyester carbonate, and liquid crystalline polyester elastomer. Among them, liquid crystalline polyester and liquid crystalline polyesteramide are preferably produced.

As the liquid crystalline polyester, a polyester which forms an anisotropic molten phase comprising a structural unit selected from an aromatic oxycarbonyl unit, an aromatic dioxy unit, an aromatic dicarbonyl unit, an ethylenedioxy unit and the like can be used. And the liquid crystalline polyester amide includes the above structural unit and an aromatic iminocarbonyl unit;
Polyester amides that form a fusible anisotropic phase composed of structural units selected from aromatic diimino units, aromatic iminooxy units, and the like are included.

In the above, the raw materials that can constitute the structural units of the liquid crystalline polyester or the liquid crystalline polyester amide include aromatic hydroxycarboxylic acids, dihydroxy compounds, aromatic dicarboxylic acids, polyesters comprising a dioxy unit and a dicarbonyl unit, and aromatic polyesters. Aromatic aminohydroxy compounds, aromatic aminocarboxylic acids and derivatives thereof, and the like, and the types and compositions thereof are appropriately combined so that the resulting polymer exhibits liquid crystallinity, thereby producing a liquid crystal resin of interest. be able to.

The aromatic hydroxycarboxylic acids include p-hydroxybenzoic acid and 6-hydroxy-2
-Naphthoic acid; and the aromatic dihydroxy compound includes 4,4'-dihydroxybiphenyl,
3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, phenylhydroquinone, methylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2, 2-bis (4-hydroxyphenyl) propane and 4,4'-dihydroxydiphenyl ether.

The aromatic dicarboxylic acids include
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-chlorophenoxy) ethane-
Polyesters comprising 4,4'-dicarboxylic acid and diphenyl ether dicarboxylic acid, etc. comprising the above dioxy units and dicarbonyl units include polyethylene terephthalate or oligomers thereof.

Further, the aromatic aminohydroxy compound includes p-aminophenol and the like, and the aromatic aminocarboxylic acid includes p-aminobenzoic acid and the like.

The liquid crystalline resin preferably produced in the present invention is a liquid crystalline resin containing a structural unit composed of p-hydroxybenzoic acid as an aromatic oxycarbonyl unit, and a liquid crystal resin containing an ethylenedioxy unit as an essential component. A hydrophilic resin can also be preferably produced.

As the liquid crystalline polyester, a liquid crystalline polyester comprising the following structural units (I), a liquid crystalline polyester comprising the following structural units (I), (II) and (IV), the following structural units (I) and (IV) III), a liquid crystalline polyester comprising (IV) and the following structural units (I), (II),
Liquid crystalline polyesters comprising (III) and (IV) are preferred, and among them, the following structural units (I), (III) and (I)
Liquid crystalline polyesters composed of the following structural units (I), (II), (III), and (IV) are more preferable.
A liquid crystalline polyester comprising I), (III) and (IV) is most preferably produced.

[0027]

Embedded image (However, R ₁ in the above formula is

[0028]

Embedded image R ₂ represents one or more groups selected from

[0029]

Embedded image R ₃ represents one or more groups selected from

[0030]

Embedded image Represents one or more groups selected from X in the formula represents a hydrogen atom or a chlorine atom. Here, the structural unit (I) is a structural unit generated from p-hydroxybenzoic acid and / or 6-hydroxy-2-naphthoic acid, and the structural unit (II) is 4,4′-dihydroxybiphenyl; 3,3 ', 5,5'-tetramethyl-4,4'-
Dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, phenylhydroquinone, methylhydroquinone, 2,6-dihydroxynaphthalene, 2,7
-A structural unit formed from an aromatic dihydroxy compound selected from dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane and 4,4'-dihydroxydiphenyl ether.

The structural unit (III) is a structural unit formed from ethylene glycol, and the structural unit (IV) is terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6- Selected from naphthalenedicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid and diphenyletherdicarboxylic acid It is a structural unit formed from an aromatic dicarboxylic acid.

Preferred examples of the liquid crystalline polyester amide include 6-hydroxy-2-naphthoic acid and p-
Liquid crystalline polyesteramide formed from aminophenol and terephthalic acid, and p-hydroxybenzoic acid,
4,4'-dihydroxybiphenyl, terephthalic acid, p
Liquid crystalline polyesteramide formed from aminobenzoic acid and polyethylene terephthalate (JP-A-64-331)
No. 23).

Among these liquid crystalline resins, in the case of a liquid crystal polyester comprising the above structural unit (I), a structural unit (I-1) comprising p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. Structural unit (I-2)
Is preferred.

The structural units (I), (II) and (I)
In the case of the liquid crystal polyester comprising V), R ₁ of the structural unit (I) is

[0035]

Embedded image And R _{2 of the} structural unit (II) is

[0036]

Embedded image At least one group selected from the group consisting of R
₃ is

[0037]

Embedded image Those which are one or more groups selected from

In the case of a liquid crystal polyester comprising the above structural units (I), (III) and (IV), the R of the structural unit (I)
₁ is

[0039]

Embedded image And R _{3 of the} structural unit (IV) is

[0040]

Embedded image Those which are one or more groups selected from

The above structural units (I), (II), (III),
In the case of the liquid crystal polyester comprising (IV), R ₁ of the structural unit (I) is

[0042]

Embedded image And R _{2 of the} structural unit (II) is

[0043]

Embedded image And R _{3 of the} structural unit (IV) is

[0044]

Embedded image Is particularly preferred.

The above structural units (I), (II),
The copolymerization amount of (III) and (IV) is optional. However, the following copolymerization amount is preferred from the viewpoint of fluidity.

That is, in the case of the liquid crystal polyester comprising the structural unit (I), the structural unit (I-1) comprising p-hydroxybenzoic acid and the structural unit (I-2) comprising 6-hydroxy-2-naphthoic acid. When the respective molar ratios are [I-1] and [I-2], [I-1] / [I-
2] is preferably in the range of 60/40 to 90/10, and 65
The range of / 35 to 85/15 is more preferable.

The structural units (I), (II) and (I)
In the case of the liquid crystal polyester comprising V), the structural unit (I) is 1% of the total of the structural units (I) and (II).
It is preferably in the range of 5 to 90 mol%, and 30 to 8
A range of 8 mol% is more preferable, and a range of 50 to 85 mol% is most preferable. Further, it is preferable that the structural unit (IV) is substantially equimolar to the structural unit (II).

In the case of a liquid crystal polyester comprising the structural units (I), (III) and (IV), the structural unit (I)
Is from 30 to the total of the structural units (I) and (III).
It is preferably in the range of 95 mol%, more preferably in the range of 40 to 95 mol%. The structural unit (IV) is preferably substantially equimolar to the structural unit (III).

Further, the structural units (I), (II),
In the case of a liquid crystal polyester composed of (III) and (IV),
From the viewpoints of heat resistance, flame retardancy and mechanical properties, the sum of the structural units (I) and (II) is determined by the structural units (I) and (I)
It is preferably in the range of 60 to 95 mol%, more preferably in the range of 80 to 92 mol%, based on the total of I) and (III). The structural unit (III) is 40 to 5 with respect to the total of the structural units (I), (II) and (III).
It is preferably in the range of mol%, more preferably in the range of 20 to 8 mol%. And the structural units (I) and (II)
The molar ratio [(I) / (II)] is preferably in the range of 75/25 to 95/5, more preferably 78/22 to 93/7, from the viewpoint of the balance between heat resistance and fluidity. Range. The structural unit (IV) is preferably substantially equimolar to the sum of the structural units (II) and (III).

Here, the term "substantially" means that either the carboxyl group terminal or the hydroxyl group terminal of the polyester terminal group can be increased as required.
In such a case, the number of moles of the structural unit (IV) is not completely equal to the total number of moles of the structural units (II) and (III).

Further, as the liquid crystalline polyester amide resin, in addition to the above structural units (I) to (IV), polyesters forming an anisotropic molten phase containing p-iminophenoxy units generated from p-aminophenol Amides are preferred.

The liquid crystalline polyester or the liquid crystalline polyester amide contains, in addition to the components constituting the structural units (I) to (IV), 3,3′-diphenyldicarboxylic acid,
Aromatic dicarboxylic acids such as 2,2'-diphenyldicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecandioic acid; alicyclic dicarboxylic acids such as hexahydroterephthalic acid; chlorohydroquinone; 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide,
Aromatic diols such as 4,4'-dihydroxybenzophenone and 3,4'-dihydroxybiphenyl;
Butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol,
Aliphatic, alicyclic diols such as 1,4-cyclohexanedimethanol and m-hydroxybenzoic acid, 2,6-
An aromatic hydroxycarboxylic acid such as hydroxynaphthoic acid and p-aminobenzoic acid can be further copolymerized within a range that does not impair the liquid crystallinity.

In the present invention, the liquid crystalline resin is produced by a deacetic acid polycondensation reaction. In this case, the hydroxyl group is deacetylated using a raw material in which the hydroxyl group is previously acetylated, and the hydroxyl group-containing monomer and the acetylating agent are used as raw materials for forming the liquid crystal resin, and the hydroxyl group is acetylated. Acetylation reaction and deacetic acid polymerization reaction in some cases, the latter method is preferred.

In the present invention, acetic anhydride is preferably used as the acetylating agent. In addition, the acetylating agent
The molar ratio is 0.1 to the number of moles of the hydroxyl group of the monomer.
It is preferable to be in the range of 9 to 1.5 mol,
The range is more preferably from 0.95 to 1.3 mol.

As a specific reaction method, a hydroxyl group-containing compound, a carboxylic acid group-containing compound and an acetylating agent such as acetic anhydride are used as represented by the following method (A) or (B). After acetylation of the hydroxyl group, there is a method in which the temperature is raised and deacetic acid polycondensation is performed under reduced pressure, and a method in which the hydroxyl group-containing compound is replaced with an acetylated compound in this method. Is particularly preferred.

In the following, the production method of (A) is preferably applied when a polyester comprising a dioxy unit and a dicarbonyl unit is not used as a raw material, and the production method of (B) is preferably applied when the polyester is used.

(A) p-hydroxybenzoic acid, 4,4 '
-Dihydroxybiphenyl, aromatic dihydroxy compounds such as hydroquinone, acetic anhydride is reacted with an aromatic dicarboxylic acid such as terephthalic acid to acetylate the phenolic hydroxyl group, and then heated, and then subjected to deacetic acid polycondensation reaction under reduced pressure. A method for producing a liquid crystalline polyester.

(B) Polyester polymers such as polyethylene terephthalate, oligomers or bis (β-
A method for producing a liquid crystalline polyester by the method (1) in the presence of a bis (β-hydroxyethyl) ester of an aromatic dicarboxylic acid such as (hydroxyethyl) terephthalate.

These polycondensation reactions proceed without a catalyst, but when a metal compound such as stannous acetate, tetrabutyl titanate, potassium acetate, sodium acetate, antimony trioxide and metal magnesium is added as a catalyst, or It may be preferable to add compounds such as sodium hypophosphite and potassium hypophosphite which are effective as a catalyst and a color tone improver.

In the present invention, the method for polymerizing the liquid crystalline resin is not particularly limited.
Alternatively, it can be produced according to a polycondensation method of a liquid crystalline polyesteramide.

Such a polycondensation reaction is usually carried out in a polycondensation reactor, and the liquid crystalline resin after the polymerization is finished in a molten state through a discharge device such as a nozzle (or a base) to the outside of the reaction vessel. It is discharged in the form of a strand.

In the present invention, the liquid crystalline resin in a molten state is discharged as a group of strands into a trough into which cooling water has flowed through a discharging device, and the group of strands is cooled and solidified and cut in the presence of the cooling water. At the time of pelletizing, at least a strand group is discharged from the discharge device, and in a trough at the initial discharge until the strand group reaches the cutter portion,
1.1 times or more 10 times the amount of cooling water during steady pelletization
It is essential that the cooling water flow is twice or less.

The term “steady pelleting” as used herein refers to a state in which the strand group is stably supplied to the cutter unit and pelletized.
5 to 100 m ³ / hour per 1 m of trough width is preferred,
10 to 50 m ³ / hour is more preferably used.

The trough at the initial stage of discharge until the strand group is discharged from the discharge device and the strand group reaches the cutter unit is 1.1 to 10 times the cooling water amount during steady pelletization. It is essential to flow the cooling water, but it is preferably 1.2 times or more and 7 times or less,
More preferably, it is 1.3 times or more and 5 times or less. If the amount of cooling water at the initial stage of discharge is less than the above range, the strand group stays on the trough, and there is a tendency that normal discharge cannot be performed.If the amount exceeds the above range, the strand group may bend or meander. However, there is an undesirable tendency that good pellets cannot be obtained and that the cooling water cannot be processed in the cutter portion and overflows.

There is no particular limitation on the method of implementing the cooling means. As a specific example, a cooling water bypass line or a new cooling water line is provided, and these lines are opened only at the initial stage of discharge. A method of closing the bypass line or a new cooling line after a certain period of time sufficient for the strand group to reach the cutter or the strand group to reach the cutter to obtain a steady cooling water amount, and a constant initial discharge. There is a method of increasing the setting of the cooling water amount only for the time.

The trough has a downward slope from the vicinity of the discharge section toward the cutter section, and the trough angle is 0 with respect to the horizontal axis.
Degrees, preferably 30 degrees or less, more preferably 2 degrees or more and 20 degrees or less, and more preferably 5 degrees or more and 1 degree or less.
Most preferably, it is 5 degrees or less. The trough angle referred to here is the angle at which the trough is inclined with respect to the horizontal axis. When the trough is formed of a single plane, the angle formed by the plane and when the trough is formed of two or more planes Means the average angle.

Further, the length of the trough is preferably in the range of 1 to 3 m, more preferably in the range of 1.5 to 2.5 m.

The temperature of the cooling water flowing through the trough is preferably in the range of 5 to 90 ° C., more preferably in the range of 10 to 60 ° C.

The diameter of the discharge port is preferably in the range of 1 to 10 mm, more preferably in the range of 2 to 7 mm, and most preferably in the range of 3 to 5 mm.

Further, the take-up speed of the strand group is 5
The range is preferably 0 to 400 m / min, and 70 to 300 m / min.
The range of minutes is more preferred.

An example of the method for producing a liquid crystalline resin pellet of the present invention will be described below with reference to the drawings.

FIG. 1 is an example of a process chart for explaining a method for producing a pellet which is preferably used when the liquid crystalline resin after polymerization is pelletized in the present invention.

After the liquid crystalline resin is polymerized in the reaction vessel (only the main part is partially shown), the liquid crystalline resin still in a molten state is discharged as a group of strands 3 from the base 2 of the reaction vessel. Is done.

The strand group 3 is discharged into the trough 7 through which the cooling water 6 flows from the cooling water supply bypass line 4 and the cooling water supply line 5, and cools the cooling water flowing through the trough 7. Then, it is conveyed to a cutter unit including a strand group take-up roll 8, a strand group cutting fixed blade 9, and a strand group cutting rotary blade 10.

After a lapse of time sufficient for the strand group 3 to reach the cutter portion at the initial stage of the discharge, the cooling water from the cooling water supply bypass line 4 is stopped, and only the cooling water supplied from the cooling water supply line 5 is removed. Become.

After the strand group 3 is taken up by the strand group take-up roll 8, it is cut in water by the strand group cutting fixed blade 9 and the strand group cutting rotary blade 10 to obtain a pellet 11. The cut pellets 11 are conveyed to the pellet receiving tank 12 by the cooling water flowing into the pellet receiving tank 12 from the trough via the cutter portion, and then subjected to a draining step (not shown).

Although not always necessary, a strand group cooling spray can be provided above the trough in order to cool the transported strand group and maintain running stability.

The drained pellets are dried in a usual manner to be subjected to the next step such as production or molding of a composition. The drained pellets are conveyed while being dried by means of air blowing or the like. Then, it can be provided to the next step.

As described above, by flowing the cooling water amount 1.1 to 10 times the cooling water amount at the time of steady pelletization into the trough at the initial stage of discharge until the strand group reaches the cutter portion, Good pellets can be obtained based on excellent discharge stability without staying in the trough, preventing normal discharge, or bending or meandering the strand group.

The melt viscosity of the liquid crystalline resin pellet obtained by the method of the present invention is preferably in the range of 1 to 2000 Pa · s, more preferably in the range of 2 to 1000 Pa · s. The case where the pressure is in the range of １００100 Pa · s is more effective.

The term “melt viscosity” used herein means the melting point (T
m) A value measured by a Koka type flow tester using a nozzle having a nozzle diameter of 0.5 mmφ and a nozzle length of 10 mm under a condition of + 10 ° C. and a shear rate of 1000 (1 / second). The melting point (Tm) refers to an endothermic peak temperature (Tm) observed when a polymer that has been polymerized is measured from a room temperature under a heating condition of 40 ° C./min.
After observing 1), after holding at a temperature of Tm1 + 20 ° C. for 5 minutes, and once cooling to room temperature under a cooling condition of 20 ° C./min,
It refers to the peak of the endothermic peak temperature (Tm2) observed when the temperature is measured again under the temperature rising condition of 20 ° C./min.

The liquid crystalline resin pellets produced in the present invention include glass fiber, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, aluminum borate fiber, gypsum fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber. , Boron whisker fiber, asbestos fiber, graphite, mica, talc, wet or dry silica,
Colloidal silica, calcium carbonate, glass beads, glass flakes, glass microballoons, clay, wollastenite, titanium oxide, molybdenum disulfide, calcium phosphate, barium sulfate, alumina, zirconia, etc. Reinforcing agents such as inorganic fillers, antioxidants, heat stabilizers, flame retardants, ultraviolet absorbers,
By adding ordinary additives such as a lubricant, a release agent, a dye, and a pigment, and other thermoplastic resins, predetermined characteristics can be imparted.

As a method for adding these, it is preferable to melt-knead the liquid crystalline resin pellets and other components.
Known methods can be used for the melt-kneading. For example, the composition can be melt-kneaded at a temperature of 200 to 400 ° C. using a Banbury mixer, a rubber roll machine, a kneader, a single-screw or twin-screw extruder, or the like to obtain a composition.

Further, since the liquid crystalline resin pellets produced in the present invention are excellent in supplyability and quantitativeness, molded articles can be produced by efficiently and stably providing them for molding such as injection molding. Also, when the liquid crystalline resin pellets produced by the present invention are supplied to a melt kneader such as a twin screw extruder with other components, the composition can be produced stably and efficiently.

The liquid crystalline resin pellets produced according to the present invention or the resin composition comprising the same and other additives is
It can be applied to various molded article applications. Specific examples of these molded products include various gears, various cases, sensors, LED lamps, connectors, sockets, resistors, relay case switch coil bobbins, capacitors, variable condenser cases, optical pickups, oscillators, various terminal boards, transformers, Plug, printed wiring board, tuner, speaker, microphone, headphone, small motor, magnetic head base, power module, housing, semiconductor, liquid crystal display parts, FDD carriage, FDD
Chassis, HDD parts, motor brush holder,
Electrical and electronic parts such as parabolic antennas and computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave parts, acoustic parts, audio laser disks (registered trademark), compact disks, etc. Audio equipment parts, lighting parts, refrigerator parts, air conditioner parts, typewriter parts,
Home and office electrical product parts such as word processor parts, office computer related parts, telephone related parts, facsimile related parts, copier related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings, etc. Machine-related parts such as bearings, motor parts, lighters, typewriters, etc., optical equipment such as microscopes, binoculars, cameras, clocks, etc., precision machine-related parts, alternator terminals, alternator connectors, IC regulators, light regulators Various valves such as potentiometer base and exhaust gas valve for
Various pipes for fuel, exhaust system, intake system, air 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 pad wear sensor , Throttle position sensor, crankshaft position sensor, air flow meter, brake butt wear sensor, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts, Distributors, starter switches,
Starter relay, transmission wire harness, window washer nozzle, air conditioner panel switch board, fuel-related electromagnetic valve coil, fuse connector, horn terminal, electrical component insulation board, step motor rotor, lamp socket, lamp reflector, lamp housing, brake Automobile and vehicle-related parts such as pistons, solenoid bobbins, engine oil filters, and ignition device cases.

[0086]

The present invention will be described in more detail with reference to the following examples. Example 1 A 1.6 m ³ reaction vessel equipped with a stirring blade and a distilling tube was charged with 221.0 kg of p-hydroxybenzoic acid,
27.8 kg of 4'-dihydroxybiphenyl, 24.8 kg of terephthalic acid, 47.8 kg of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g, and acetic anhydride 2
After charging 11.8 kg, the mixture was reacted at 140 ° C. for 1 hour with stirring under a nitrogen gas atmosphere, and then 3.5 ° to 250 ° C.
Temperature for 3 hours and then to 320 ° C. for 3 hours.
The pressure was reduced to 33 Pa, and stirring was continued at 320 ° C. for 0.5 hour to complete the polycondensation reaction.

Next, the inside of the reaction vessel was pressurized to 0.3 MPa, and a polymer at 320 ° C. was passed through a die having a diameter of 4 mm to a trough angle of 10 degrees, a trough length of 2 m, and a trough width of 40 c.
m was discharged into a trough in the form of a strand.

Immediately after the discharge, for the first minute including the time required for the strand group to reach the cutter section, cooling water flows from the cooling water supply line as well as the cooling water supply bypass line. 60 m ³ / hour (2.4 times the steady state).

Thereafter, the cooling water supply bypass line was closed, and the cooling water amount was set to 25 m ³ / hour per 1 m of trough width. The cooling water was at a temperature of 20 ° C., and pelletized into a size of a major axis of 4 mm, a minor axis of 2 mm and a length of 3 mm by a cutter in the presence of the cooling water. This liquid crystal polyester resin has a melting point of 315 ° C. and a melt viscosity of 25 Pa at 325 ° C.
-It was s.

The above reaction was repeated 10 times, but there was no stagnation of the strand group in the trough at the beginning of discharge, and pelletization could be carried out smoothly. The shape of the obtained pellet was also good. [Comparative Example 1] Pelletization was performed in the same manner as in Example 1 except that the cooling water amount at the initial stage of discharge was 25 m ³ / hour per 1 m of trough width and was equal to the cooling water amount at the time of steady state. Since the strand group stayed on the trough three times, it was necessary to interrupt the pelletization each time, remove the accumulated matter, and restart the pelletization, and the discharge stability was extremely poor. [Comparative Example 2] Pelletization was performed in the same manner as in Example 1 except that the amount of cooling water was set to 60 m ³ / hour per 1 m of trough width from the beginning to the end of discharge. However, the group of strands being discharged meandered, the number of diagonally cut chips increased, and the pellet shape deteriorated.

[0091]

As described above, according to the present invention,
A liquid crystal resin pellet having a good shape can be manufactured based on excellent ejection stability.

[Brief description of the drawings]

FIG. 1 is a process chart illustrating an example of a method for producing a liquid crystalline resin pellet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction container (part) 2 Reactor cap 3 Strand group 4 Cooling water supply bypass line 5 Cooling water supply line 6 Cooling water 7 Trough 8 Strand group take-off roll 9 Strand group cutting fixed blade 10 Strand group cutting rotary blade 11 Pellet 12 Pellet receiving tank 13 strand group cooling spray

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F070 AA47 DA05 DA12 4F201 AA23B AP06 BA02 BC01 BC13 BC19 BL13 BL43 BN12 BQ34

Claims (4)

[Claims] 1. A liquid crystal resin in a molten state is discharged as a group of strands into a trough into which cooling water has flowed through a discharging device, and the group of strands is cooled and solidified and cut in the presence of the cooling water. A pellet group is discharged from at least the discharging device, and in the trough at the initial stage of discharging until the strand group reaches the cutter portion, the cooling water amount at the time of steady pelletization is obtained. A method for producing liquid crystalline resin pellets, characterized by flowing 1.1 to 10 times the amount of cooling water. 2. The trough has a downward gradient from near the discharge section toward the cutter section, and the trough angle is 0 with respect to a horizontal axis.
The method for producing liquid crystalline resin pellets according to claim 1, wherein the temperature is greater than 30 degrees and less than 30 degrees. 3. The method for producing liquid crystalline resin pellets according to claim 1, wherein the liquid crystalline resin is a liquid crystalline polyester containing a structural unit composed of p-hydroxybenzoic acid as an essential component. . 4. The method according to claim 1, wherein the liquid crystalline resin has the following structural unit (I):
A liquid crystalline polyester comprising the following structural unit (I),
(II), a liquid crystalline polyester comprising (IV), a liquid crystalline polyester comprising the following structural units (I), (III) and (IV), and the following structural units (I), (II), (III) and (IV) )
At least one selected from the group consisting of liquid crystalline polyesters comprising: and a liquid crystalline polyester amide comprising a structural unit comprising an aromatic aminohydroxy compound and / or an aromatic aminocarboxylic acid in these liquid crystalline polyesters.
The method for producing a liquid crystalline resin pellet according to claim 1, wherein the pellet is a seed. Embedded image (However, R ₁ in the above formula is And R ₂ represents one or more groups selected from R ₃ represents one or more groups selected from Represents one or more groups selected from X in the formula represents a hydrogen atom or a chlorine atom. )