JP3475622B2 - Liquid crystalline resin and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystalline resin having an excellent color tone, good mechanical properties and a molded article appearance, a process for producing the same, and a liquid crystalline resin composition.

[0002]

A copolymerized polyester comprising a polyester unit formed from an aromatic hydroxycarboxylic acid, a polyester unit formed from an aromatic diol and an aromatic dicarboxylic acid, and a polyester unit formed from an alkylene glycol and an aromatic dicarboxylic acid is disclosed in JP 51-
It is disclosed in Japanese Patent No. 8395, Japanese Patent Laid-Open No. 58-84221, and the like.

The copolymerized polyesters disclosed in JP-A-51-8395 and JP-A-58-84821 are a. Acetylated product of aromatic hydroxycarboxylic acid,
b. A polyester obtained by condensing an aromatic dicarboxylic acid and an alkylene glycol, and c. Acetylated aromatic diol and d. The first step of charging and condensing an aromatic dicarboxylic acid
It is described that the production is carried out by the method consisting of the step 2 and the second step of reducing the pressure of the reaction system to a high molecular weight,
It is necessary to introduce the aromatic hydroxycarboxylic acid and the aromatic diol into acetylated products in advance in separate steps, which complicates the steps.

On the other hand, Japanese Patent Publication No. 6-2812 discloses a method in which a polyester obtained by condensing a hydroxycarboxylic acid, an aromatic dicarboxylic acid and an alkylene glycol and acetic anhydride are used, and the hydroxycarboxylic acid is acetylated and then polycondensed. The method is also disclosed in Japanese Examined Patent Publication (Kokoku) No. 5-53169 using p-hydroxybenzoic acid, aromatic diols, aromatic dicarboxylic acids, polyesters consisting of aromatic dicarboxylic acids and ethylene glycol, and acetic anhydride, and the hydroxy group is acetyl. A method for producing a polycondensation product after being converted into a polylactic acid is disclosed. These methods are simple in process since it is not necessary to isolate the acetylated product.

[0005]

The liquid crystalline resin produced by the method of JP-B-6-2812 and JP-B-5-53169 is a slurry of aromatic hydroxycarboxylic acid and aromatic diol in acetic anhydride. It is necessary to carry out an acetylation reaction. However, the slurry property of the aromatic hydroxycarboxylic acid is not sufficient, and stirring becomes difficult especially when polymerizing using a large-scale polymerization apparatus, and it is necessary to react without stirring until the stirring becomes possible. Therefore, not only the reaction time becomes long, but the raw material is locally heated,
It has been found that there arises a problem that the color tone of the obtained polymer deteriorates. Therefore, the present invention solves the above problems,
An object of the present invention is to obtain a resin composition having an excellent color tone and excellent heat resistance, which has good mechanical properties and a molded article appearance.

[0006]

That is, according to the present invention, when a liquid crystalline polyester resin or a liquid crystalline polyesteramide resin which essentially contains a structural unit represented by the following structural unit (I) is produced, a looseness density of 0 is obtained. A method for producing a liquid crystalline resin, which comprises using p-hydroxybenzoic acid having a concentration of not less than 30 g / cm ^{3 and not} more than 0.57 g / cm ³ and / or

[Chemical 5] When producing a liquid crystalline resin composed of a liquid crystalline polyester resin or a liquid crystalline polyesteramide resin which essentially includes the structural unit represented by the structural unit (I), the bulk density is 0.50 g / cm ³ or more and 0. It is intended to provide a method for producing a liquid crystalline resin, which comprises using p-hydroxybenzoic acid at 85 g / cm ³ or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystalline polyester referred to in the present invention is a polyester which forms an anisotropic molten phase, which requires the above structural unit (I) as an essential component, and is an aromatic oxy group other than the above structural unit (I). Carbonyl units, aromatic dioxy units, aromatic dicarbonyl units, polyesters composed of structural units selected from ethylenedioxy units and the like, the liquid crystalline polyesteramide is a polyesteramide forming an anisotropic melt phase, A structural unit (I) is essential and is a polyesteramide composed of the above structural unit and a structural unit selected from an aromatic iminocarbonyl unit, an aromatic diimino unit, an aromatic iminooxy unit and the like, but containing an ethylenedioxy unit. Those are preferable. The structural unit (I)
Is preferably 20 to 95 mol%, particularly preferably 40 to 95 mol%, based on the total of all oxy units and all oxycarbonyl units.

In particular, the following structural units (I), (II), (IV) or
(I), (III), (IV) or (I), (II), (III), (IV)
Polyester consisting of the structural unit of
Polyesters consisting of (I), (II), (III) and (IV) are preferred.

[0009]

[Chemical 6] (However, R ₁ in the formula is

[Chemical 7] R ₁ represents one or more groups selected from

[Chemical 8] Represents one or more groups selected from Further, in the formula, X represents a hydrogen atom or a chlorine atom, and the structural unit [(II) + (III)]
And structural unit (IV) are substantially equimolar. ) The structural unit (I) is a structural unit of polyester produced 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, methylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,
A structural unit produced from an aromatic dihydroxy compound selected from 2,2-bis (4-hydroxyphenyl) propane and 4,4′-dihydroxydiphenyl ether, a structural unit (III) is a structural unit produced from ethylene glycol, 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-chlorophenoxy) ethane-4,4'-dicarboxylic acid and a structural unit formed from an aromatic dicarboxylic acid selected from diphenyl ether dicarboxylic acid.

Of these, the structural units (I), (II) and (I
In the case of liquid crystal polyester composed of V), R ₁ is

[Chemical 9] One or more groups selected from R ₂

[Chemical 10] It is preferable that one or more groups selected from the group represented by the following formula be used. In the case of the liquid crystal polyester comprising the above structural units (I), (III) and (IV), R ₂ is

[Chemical 11] Are preferred.

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

[Chemical 12] And R ₂ is

[Chemical 13] Are particularly preferred.

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

That is, the above structural units (I), (II), (IV)
In the case of a copolymer consisting of the above structural unit (I) is [(I)
+ (II)] is preferably 15 to 90 mol%, more preferably 30 to 88 mol%, most preferably 50 to 85 mol%. The structural unit (IV) is substantially equimolar to the structural unit (II).

In the case of a copolymer composed of the structural units (I), (III) and (IV), the structural unit (I) is [(I) +
(III)] is preferably 30 to 95 mol%, more preferably 40 to 95 mol%. Further, the structural unit (IV) is the structural unit (I
It is substantially equimolar to II).

Further, the above structural units (I), (II), (III)
, (IV), the structural unit [(I) + (II)] is [(I) + (II) + (III) in view of heat resistance, flame retardancy and mechanical properties. )] Is preferably 60 to 95 mol%, more preferably 80 to 92 mol%. Also, the structural unit
(III) is preferably 40 to 5 mol% of [(I) + (II) + (III)], and more preferably 20 to 8 mol%. The molar ratio of structural unit (I) / (II) is preferably 75/25 to 95/5, more preferably 78/22 to 93/7 from the viewpoint of the balance between heat resistance and fluidity. Also, the structural unit (I
V) is substantially equimolar to the structural unit [(II) + (III)].

Here, the term "substantially" means that the number of terminal groups of the polyester may be either carboxyl group terminals or hydroxyl group terminals in many cases. In such a case, the structural unit (IV) The number of moles is the structural unit [(II) +
This is because it is not completely equal to the total number of moles of (III)].

Further, as the liquid crystal polyesteramide resin, in addition to the above structural units (I) to (IV), p-aminophen-
Polyester amides which form an anisotropic melt phase containing p-iminophenoxy units generated from styrene are preferred.

The preferred liquid crystal polyester or liquid crystal polyester amide is 3,3'-diphenyldicarboxylic acid, 2,3 in addition to the components constituting the structural units (I) to (IV).
Aromatic dicarboxylic acids such as 2′-diphenyldicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, 4,4 ′ -Dihydroxydiphenyl sulfone,
4,4'-dihydroxydiphenyl sulfide, 4,4
Aromatic diols such as ′ -dihydroxybenzophenone, 3,4′-dihydroxybiphenyl, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol Such as aliphatic, alicyclic diols and aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, and p-
Aminobenzoic acid and the like can be further copolymerized in a small proportion.

The characteristic feature of the method for producing the liquid crystalline polyester or the liquid crystalline polyesteramide produced by the present invention is that the loose bulk density is 0.30 g / cm ³ or more and 0.57 g / cm ³
Below and / or hard bulk density 0.50 g / cm ³
The use of p-hydroxybenzoic acid of 0.85 g / cm ³ or less and the weight average particle diameter of 0.17 m
It is preferably m or more and 2 mm or less. Bulk density 0.40 g / cm ³ or more loosened, is preferably 0.56 g / cm ³ or less, 0.45 g / cm ³ or more,
It is more preferably 0.56 g / cm ³ or less. Also, the bulk density is 0.60 g / cm ³ or more, 0.83 g / cm
Preferably ³ or less, 0.70 g / cm ³ or more, 0.81 g / cm ³ or less is more preferable. On the other hand, the weight average particle diameter is preferably 0.2 mm or more and 1 mm or less, more preferably 0.21 mm or more and 0.65 mm or less. Furthermore, the angle of repose is preferably 40 to 60 degrees, more preferably 42 to 57 degrees, and 48 to 55.
Degree is particularly preferred. Loose bulk density is 0.30 g / cm
Less than ³ or greater than 0.57 g / cm ³ , and
The bulk density is less than 0.50 g / cm ³ or 0.
If it is more than 85 g / cm ³ , the slurry property becomes insufficient, and it becomes difficult to stir when polymerizing using a large-scale polymerization apparatus in which the charged amount of p-hydroxybenzoic acid is 50 kg or more, particularly 100 kg or more, and the raw material is locally Due to the heating, the color tone of the liquid crystalline resin deteriorates, and the object of the present invention cannot be achieved.

Here, the loose bulk density means that an open glass tube having an outer diameter slightly smaller than the inner diameter of the measuring container is put in the measuring container, a constant weight of p-hydroxybenzoic acid is put in the open glass tube, and the glass tube is opened. It is obtained by gently pulling it up and depositing it in a measuring container, and using the volume obtained from the deposition height.

On the other hand, the bulk density can be measured by using a powder tester (manufactured by Hosokawa Micron Co., Ltd.). This is because a fixed weight of p-hydroxybenzoic acid was placed in a measuring container of known capacity with a cylinder attached, and the container was tapped 180 times, then the upper cylinder was removed and the cup was placed on top of the cup. It can be obtained by grinding a certain powder with a blade and measuring the weight of the powder.

Further, a sieve having a weight average particle diameter of 10 to 600 mesh is used, and the mesh number of one sieve and the sieve closest to it and having a large mesh number is about 1.5 to 2 times the mesh number. Stack from the smallest number to the lower one, and place the container without mesh at the bottom (however, the weight ratio remaining in the uppermost sieve and the lowermost container is less than 5%). ), Sieving using a vibrating sieving machine, determining the weight ratio of p-hydroxybenzoic acid remaining in each sieve, multiplying it by the average of the opening intervals of the sieve and the sieve opening above it, (However, those left on the uppermost sieve are multiplied by the openings of the uppermost sieve, and those left on the lowermost container are multiplied by the opening of the sieve with the largest mesh number.) It can be determined by sum for sieve.

There are no particular restrictions on the manufacturing method in respect of the points other than the above, and it can be manufactured in accordance with the known polycondensation method of polyester or polyesteramide.

For example, in the production of the above-mentioned preferably used liquid crystalline polyester resin, the following production method is preferably exemplified.

Aromatic dihydroxy compounds such as p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl and hydroquinone, aromatic dicarboxylic acids such as acetic anhydride and terephthalic acid, polyester polymers such as polyethylene terephthalate, oligomers or bis (β A bis (β-hydroxyethyl) ester of an aromatic dicarboxylic acid such as -hydroxyethyl) terephthalate is charged into a polymerization apparatus. At this time, the raw materials are preferably charged at 100 ° C. or lower, and the amount of acetic anhydride used is preferably 1.0 to 1.5 times the molar amount of the hydroxy groups of the starting raw materials, and particularly 1. The molar amount is preferably 05 to 1.2. After that, 50 to 200 ° C., preferably 70
Acetylation is performed at ˜180 ° C., more preferably 80 to 170 ° C., and after acetylation, the temperature is raised to 200 to 350 ° C., preferably 220 ° C. to 330 ° C., and deacetic acid polymerization is performed under reduced pressure. The liquid crystalline resin can be obtained. Further, this reaction under normal pressure is preferably carried out in an atmosphere of an inert gas such as nitrogen in order to suppress the oxidative decomposition reaction.

Although these polycondensation reactions proceed without a catalyst, it is sometimes preferable to add a metal compound such as stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, or magnesium metal. .

Some liquid crystal polyester resins or liquid crystal polyester amide resins produced by the present invention can be measured for logarithmic viscosity in pentafluorophenol, in which case the concentration is 0.1 g / dl and 60 ° C. It is preferably 0.3 or more in the value measured in 1., when the structural unit (III) is included, it is 0.5 to 3.0 dl / g, and when the structural unit (III) is not included, it is 1.0 to 15.0 dl / g. Is particularly preferable.

The liquid crystal polyester or liquid crystal polyesteramide produced by the present invention has a melt viscosity of 10 to 20.
000 poises are preferable, and 20 to 10,000 poises are particularly preferable.

Further, the melting point of the liquid crystalline polyester or the liquid crystalline polyesteramide is preferably 350 ° C. or lower.

The mechanical properties and heat resistance can be further improved by adding the filler (B) to the liquid crystalline resin comprising the liquid crystalline polyester and / or the liquid crystalline polyesteramide of the present invention. .

The amount of the filler used as the component (B) is 1 to 200 parts by weight, preferably 15 to 150 parts by weight, based on 100 parts by weight of the liquid crystal polyester resin and / or the liquid crystal polyesteramide resin, and the glass fiber. ,
Carbon fiber, aromatic polyamide fiber, potassium titanate fiber, aluminum borate fiber, gypsum fiber, brass fiber, stainless fiber, steel fiber, ceramic fiber, boron whisker fiber, asbestos fiber, graphite, mica, talc, silica, calcium carbonate ,Glass beads,
Examples thereof include fibrous, powdery, granular or plate-like inorganic fillers such as glass flakes, glass microballoons, clay, wollastonite, titanium oxide and molybdenum disulfide. In addition, as these fillers, those treated with a coupling agent such as a silane type or titanate type, or other surface treatment agent may be used.

The method of adding these is preferably melt kneading, and known methods can be used for melt kneading. For example, Banbury mixer, rubber roll machine,
Using a kneader, single-screw or twin-screw extruder, etc., 200
The composition can be obtained by melt-kneading at a temperature of ˜370 ° C.

In the present invention, an organic bromine compound (C) can be further added for the purpose of imparting flame retardancy.
The organic bromine compound has a bromine atom in the molecule, and particularly preferably has a bromine content of 20% by weight or more. Specifically, low molecular weight organic bromine compounds such as decabromodiphenyl ether, ethylene bis- (tetrabromophthalimide), brominated polycarbonate (for example, a polycarbonate oligomer produced from brominated bisphenol A as a raw material or its copolymerization with bisphenol A). Products), brominated epoxy compounds (for example, diepoxy compounds produced by the reaction of brominated bisphenol A with epichlorohydrin, monoepoxy compounds obtained by the reaction of brominated phenols with epichlorohydrin), poly (brominated benzyl acrylate), Brominated polyphenylene ether, brominated bisphenol A, condensate of cyanuric chloride and brominated phenol, brominated polystyrene, crosslinked brominated polystyrene, crosslinked brominated poly α
Examples include halogenated polymers and oligomers such as methylstyrene, and mixtures thereof. Among them, ethylene bis- (tetrabromophthalimide), brominated epoxy oligomer or polymer, brominated polystyrene, crosslinked brominated polystyrene, brominated Polyphenylene ether and brominated polycarbonate are preferable, and ethylene bis- (tetrabromophthalimide), brominated polystyrene, and brominated polycarbonate can be particularly preferably used. The above preferable organic bromine compound will be described in more detail. As the brominated epoxy polymer, those represented by the following general formula (a) are preferable.

[0034]

[Chemical 14] The polymerization degree n in the general formula (a) is preferably 15 or more,
More preferably, it is 50-80. Further, as the brominated polystyrene, one represented by the following formula (b) having a weight average molecular weight of 1 × 10 ^{3 to} 3 × 10 ⁵ produced by brominating polystyrene obtained by radical polymerization or anionic polymerization, or Examples thereof include polybrominated styrene having a brominated styrene unit represented by the formula (b) or (c), which is produced by radical polymerization or anionic polymerization of brominated styrene monomer, preferably brominated styrene. Weight average molecular weight 1 × 10 ^{3 to} 3 × 10 ⁵ containing a structural unit represented by the following formula (c), which is produced from a monomer, as a main constituent
Of polybrominated styrene are preferred.

[0035]

[Chemical 15] Brominated styrene monomer here means styrene monomer 1
It is preferable that about 2 bromine atoms are introduced into the aromatic ring per one by a substitution reaction, and monobrominated styrene, tribrominated styrene and the like may be contained in addition to dibrominated styrene. The polybrominated styrene preferably contains dibrominated styrene units in an amount of 60% by weight or more.
Those containing 0% by weight or more are more preferable. In addition to dibrominated styrene, 40% by weight or less of monobrominated styrene and / or tribrominated styrene, preferably 30% by weight
The following may be copolymerized polybrominated styrene. The weight average molecular weight of this polybrominated styrene is 1 × 10 ⁴ to
1.5 × 10 ⁵ is more preferable. Weight average molecular weight is 1x
If it is less than 10 ³ , the mechanical properties and solder heat resistance at the time of molding are deteriorated, and if it is more than 3 × 10 ⁵ , the fluidity of the composition of the present invention tends to be poor. The weight average molecular weight is a value measured using a gel permeation chromatograph and is a relative value based on polystyrene molecular weight. As the brominated polycarbonate, those represented by the following general formula (d) are preferable.

[0036]

[Chemical 16] (R ₃ and R _{4 each} represent a substituted or unsubstituted aryl group, and a pt-phenyl group is most preferable.) The polymerization degree n in the above formula (d) is preferably 4 or more, and 8 or more. Especially, 8 to 25 can be used more preferably. The amount of the organic bromine compound (C) added is 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the liquid crystal polyester.

The method of adding these is preferably melt kneading, and known methods can be used for melt kneading. For example, Banbury mixer, rubber roll machine,
Using a kneader, single-screw or twin-screw extruder, etc., 200
The composition can be obtained by melt-kneading at a temperature of ˜370 ° C.

Further, the flame-retardant liquid crystal polyester composition of the present invention contains an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphite ester, etc.) to the extent that the object of the present invention is not impaired. And their substitutes), ultraviolet absorbers (eg resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and mold release agents (montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide, polyethylene and polyethylene and Polyethylene wax, etc.), dye (eg nitrocin, etc.)
Ordinary additives such as colorants including pigments (eg, cadmium sulfide, phthalocyanine, carbon black, etc.), plasticizers, antistatic agents, and other thermoplastic resins can be added to impart predetermined characteristics. .

The method of adding these is preferably melt kneading, and known methods can be used for melt kneading. For example, Banbury mixer, rubber roll machine,
Using a kneader, single-screw or twin-screw extruder, etc., 200
The composition can be obtained by melt-kneading at a temperature of ˜370 ° C.

The liquid crystalline resin and the liquid crystalline resin composition of the present invention thus obtained have excellent melt flowability, moldability and optical anisotropy, and have excellent heat resistance, chemical resistance, and It can be processed into three-dimensional molded products, sheets, container pipes, etc. that have hydrolysis resistance and mechanical properties. For example, various gears, various cases, sensors,
LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers, microphones, headphones, small size 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 oven parts, audio parts, audio equipment parts such as audio / laser disks / compact disks , Lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, etc.
Office computer related parts, telephone related parts, facsimile related parts, copier related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings, and other bearings,
Mechanical parts such as motor parts, lighters and typewriters, optical devices such as microscopes, binoculars, cameras and watches, precision mechanical parts; alternator terminals, alternator connectors, IC regulators, light deer potentiometers Various valves such as base, exhaust gas valve, fuel related / exhaust system / intake system various pipes, 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 bat wear sensor, air conditioner thermostat base, heating hot air flow control valve, radiator motor brush holder, water pump impeller, turbine vane, wiper motor related parts, Duss Tributors, starter switches, starter relays, transmission wire harnesses, window washer nozzles, air conditioner panel switch boards, fuel-related electromagnetic valve coils, fuse connectors, horn terminals, electrical component insulating plates, step motor rotors, lamp sockets, lamps Reflector, lamp housing, brake piston, solenoid bobbin, engine oil filter , Motor vehicles, such as the ignition device case
It is useful for vehicle-related parts and other various applications.

[0041]

EXAMPLES The present invention will be described in more detail below with reference to examples.

[0042] Example 1 vertical and horizontal ratio for the reaction can and polycondensation provided with a stirring blade fitted with helical ribbon blade to a height of 0.18 m ³ the polymerization apparatus having an inner volume of 0.5 m ³ 2.5 Polymerization was carried out in the following manner using the polymerization tank of No. 2.

Loosen bulk density of 0.54 g / cm in reaction can
³ , firm bulk density 0.76 g / cm ³ , weight average particle diameter 0.45 mm, angle of repose 53 degrees p-hydroxybenzoic acid 110.5 kg, 4,4′-dihydroxybiphenyl 14.0 kg, polyethylene terephthalate 24 .0
kg, terephthalic acid 12.5 kg and acetic anhydride 10
8.5 kg was charged and the atmosphere was replaced with nitrogen. Then, when the inside of the system was observed, it was observed that powder raw materials including p-hydroxybenzoic acid were precipitated. After that, when the stirring was started, the stirring was good, and the slurry property was also good. After that, the temperature inside the can is increased to 130 ° C over 1 hour.
And the reaction is carried out at 130 to 250 ° C. for 5 hours, and then the reaction product is transferred to a polymerization vessel and the temperature inside the vessel is adjusted to 25 over 2 hours.
The temperature was lowered to 0 to 315 ° C., the pressure of the polymerization vessel was reduced to 1.0 Torr, and stirring was continued at 315 ° C. for 2 hours to complete polycondensation. Then, the inside of the polymerization vessel was pressurized, and the polymer was discharged in a strand shape through the die.

The theoretical structural formula of the obtained liquid crystalline polyester (A) is as follows.

[0045]

[Chemical 17] k / l / m / n = 80 / 7.5 / 12.5 / 20 This liquid crystal polyester was applied to Sumitomo Nestal injection molding machine Promat 40/25 (Sumitomo Heavy Industries, Ltd.),
A bending test piece (1/32 "x 1/2" x 5 ") was molded under the conditions of a cylinder temperature of 330 ° C and a mold temperature of 90 ° C. Also, using this test piece, SM manufactured by Suga Test Instruments Co., Ltd. It was 68 when the whiteness (W value) was measured using the color computer apparatus.

Comparative Example 1 Using the same polymerization apparatus as in Example 1, the reaction vessel was loosened to have a bulk density of 0.60 g / cm ³ and a firm bulk density of 0.87 g / cm ³ .
cm ³ , weight average particle diameter 0.10 mm, angle of repose 38 degrees, p-hydroxybenzoic acid 110.5 kg, 4,4′-
Dihydroxybiphenyl 14.0 kg, polyethylene terephthalate 24.0 kg, terephthalic acid 12.5 kg
Then, 108.5 kg of acetic anhydride was charged and the atmosphere was replaced with nitrogen. Then, when the inside of the system was observed, it was observed that powder raw materials including p-hydroxybenzoic acid were precipitated. After that, it was attempted to start stirring, but the slurry property was poor and stirring could not be performed. After that, the temperature inside the can was raised to 130 ° C. over 2 hours with no stirring, then stirring was started, and the reaction was carried out at 130 to 250 ° C. for 5 hours. The temperature inside the can was adjusted to 250 to 315 ° C over a period of time, the pressure of the polymerization can was reduced to 1.0 Torr, and stirring was continued at 315 ° C for 2 hours to complete polycondensation.
Then, the inside of the polymerization vessel was pressurized, and the polymer was discharged in a strand shape through the die.

When the obtained liquid crystal polyester was evaluated for whiteness in the same manner as in Example 1, the color tone was 60, which was inferior to that in Example.

Comparative Example 2 Using the same polymerization apparatus as in Example 1, the reaction vessel was loosened to have a bulk density of 0.59 g / cm ³ and a solid bulk density of 0.86 g / cm ³ .
cm ³ , weight average particle diameter 0.38 mm, angle of repose 47 degrees p-hydroxybenzoic acid 110.5 kg, 4,4′-
Dihydroxybiphenyl 14.0 kg, polyethylene terephthalate 24.0 kg, terephthalic acid 12.5 kg
Then, 108.5 kg of acetic anhydride was charged and the atmosphere was replaced with nitrogen. Then, when the inside of the system was observed, it was observed that powder raw materials including p-hydroxybenzoic acid were precipitated. After that, it was attempted to start stirring, but the slurry property was poor and stirring could not be performed. After that, the temperature inside the can was raised to 130 ° C. over 2 hours with no stirring, then stirring was started, and the reaction was carried out at 130 to 250 ° C. for 5 hours. The temperature inside the can was adjusted to 250 to 315 ° C over a period of time, the pressure of the polymerization can was reduced to 1.0 Torr, and stirring was continued at 315 ° C for 2 hours to complete polycondensation.
Then, the inside of the polymerization vessel was pressurized, and the polymer was discharged in a strand shape through the die.

When the obtained liquid crystal polyester was evaluated for whiteness in the same manner as in Example 1, the color tone was 62, and the color tone was worse than that in Example.

Example 2 45 parts by weight of glass fibers having an average diameter of 10 μm and an average length of 3000 μm were mixed with 100 parts by weight of the liquid crystalline polyester of Example 1 by a ribbon blender and then heated at 310 ° C. using a 30 mmφ twin-screw extruder. After melt-kneading with, pelletized. A bending test piece was molded in the same manner as in Example 1 and the whiteness (W value) was measured and found to be 72.

Example 3 Polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer in Example 2 (bromine content 59%) 10
Melt-kneading and pelletization were performed in the same manner as in Example 1 except that parts by weight were added together with the glass fibers. It was 70 when molded in the same manner as in Example 1 and measured for whiteness.

Comparative Example 3 The liquid crystal polyester obtained in Comparative Example 1 was melt-kneaded and pelletized in the same manner as in Example 2. When this was molded in the same manner as in Example 1 and the whiteness was evaluated, it was 64, and the color tone was worse than in Example.

Comparative Example 4 Comparative Example 2 The liquid crystal polyester obtained was melt-kneaded and pelletized in the same manner as in Example 2. When this was molded in the same manner as in Example 1 and the whiteness was evaluated, it was 66, and the color tone was worse than in Example.

[0054]

INDUSTRIAL APPLICABILITY According to the present invention, a liquid crystalline resin having an excellent color tone and having good mechanical properties and a molded article appearance can be obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 63/00-63/91 C08G 69/00-69/50

Claims (7)

(57) [Claims] 1. When producing a liquid crystalline resin consisting of a liquid crystalline polyester resin or a liquid crystalline polyesteramide resin which essentially comprises a structural unit represented by the following structural unit (I), a loose bulk density is 0.30 g / cm. ³ or more 0.57 g / c
A method for producing a liquid crystalline resin, which comprises using p-hydroxybenzoic acid having a m ³ or less. [Chemical 1] 2. When producing a liquid crystalline resin consisting of a liquid crystalline polyester resin or a liquid crystalline polyesteramide resin which essentially comprises the structural unit represented by the structural unit (I), the bulk density is 0.50 g / cm ³ or more 0.85 g / c
A method for producing a liquid crystalline resin, which comprises using p-hydroxybenzoic acid having a m ³ or less. 3. The method for producing a liquid crystalline resin according to claim 1, wherein p-hydroxybenzoic acid has a bulk density of 0.50 g / cm ³ or more and 0.85 g / cm ³ or less. 4. The method for producing a liquid crystalline resin according to claim 1, wherein the weight average particle diameter of p-hydroxybenzoic acid is 0.17 mm or more and 2 mm or less. 5. A liquid crystalline polyester comprising the following structural unit (I):
It consists of (II), (III) and (IV), and has the structural unit [(I) + (I
I)] is 60 to 95 mol% of [(I) + (II) + (III)], and the structural unit (III) is 40 to 5 mol% of [(I) + (II) + (III)]. And the molar ratio of structural units (I) / (II) is 75 / 25-9
Claim and characterized in that a 5/5 1-4
The method for producing a liquid crystalline resin according to any one of 1. [Chemical 2] (However, R ₁ in the formula is It represents one or more groups selected from, R ₂ is embedded image And one or more groups selected from However, in the formula, X represents a hydrogen atom or a chlorine atom. Further, the structural unit (IV) is substantially equimolar to the structural unit [(II) + (III)]. ) 6. A charged amount of p-hydroxybenzoic acid is 50 k.
It is g or more, Any one of Claim 1-5 characterized by the above-mentioned.
A method for producing a liquid crystalline resin according to item. 7. A liquid crystalline resin obtained by the method according to any one of claims 1 to 6 .