JPH08134195A - Liquid-crystalline resin and its injection molded product - Google Patents

Abstract

PURPOSE: To obtain the liquid-crystalline resin having a specific fusion heat quantity, comprising a liquid-crystalline polyester or liquid-crystalline polyesteramide, excellent in melt flowability, optical anisotropy, heat resistance, hydrolysis resistance, etc., and useful for molded products. CONSTITUTION: This liquid-crystalline resin has a polymer fusion heat quantity of >=1.5J/g, preferably >=1.8J/g, especially preferably >=2.2J/g, and comprises a liquid-crystalline polyester or liquid-crystalline polyesteramide. The liquid- crystalline resin is preferably a liquid-crystalline polyester comprising structural units of formula I, formula II (R1 is especially preferably biphenyl), formula III, and formula IV (R2 is especially preferably phenyl).

Description

Detailed Description of the Invention

[0001]

The present invention can be obtained only by melt polymerization, has excellent melt fluidity and optical anisotropy, and has excellent heat resistance, chemical resistance and hydrolysis resistance by ordinary molding methods. And a liquid crystalline resin capable of giving a molded article having mechanical properties and an injection molded article thereof.

[0002]

2. Description of the Related Art In recent years, the demand for higher performance of plastics has been increasing, and many polymers having various new functionalities have been developed. Among them, optically anisotropic liquid crystal polymers have excellent mechanical properties. Attention is paid to the point.

[0003]

As the above-mentioned liquid crystal polymer, for example, a liquid crystal polymer in which polyethylene terephthalate is copolymerized with p-hydroxybenzoic acid is known (JP-A-49-72393). On the other hand, a liquid crystal polymer obtained by copolymerizing polyethylene terephthalate with p-hydroxybenzoic acid, an aromatic dicarboxylic acid and an aromatic diol (JP-A-63-30523 and JP-A-4-136027).
Japanese Patent Application Laid-Open No. 2004-242242) has been proposed, and it is also known that the injection-molded article obtained by this method has significantly improved heat resistance and mechanical properties as compared with the above-mentioned polymer. However, it has been found that these liquid crystalline polyesters are not always sufficient in terms of chemical resistance and hydrolysis resistance.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned objects, the present inventors have found that a liquid crystalline resin having a specific heat of fusion can achieve the object of the present invention. Came to the end.

That is, the present invention is characterized in that the polymer has a heat of fusion of 1.5 J / g or more as determined by differential calorimetry, and a liquid crystalline resin comprising a liquid crystalline polyester or a liquid crystalline polyesteramide and its injection molding. It is to provide goods.

The liquid crystal polyester referred to in the present invention comprises a structural unit selected from an aromatic oxycarbonyl unit, an aromatic dioxy unit, an aromatic dicarbonyl unit, an ethylenedioxy unit, etc., and forms an anisotropic molten phase. The polyesteramide is a liquid crystalline polyesteramide that forms an anisotropic molten phase, consisting of the structural units and aromatic iminocarbonyl units, aromatic diimino units, structural units selected from aromatic iminooxy units and the like. Of these, those having a structural unit formed from p-hydroxybenzoic acid are preferable. Further, those containing an ethylenedioxy unit are preferable, and particularly the following structural units (I) and (I
II), (IV) or (I), (II), (III), polyesters composed of structural units of (IV) are preferred, especially (I), (I
Polyesters consisting of I), (III) and (IV) are preferred.

[0007]

Embedded image (However, R ₁ in the formula is

[Chemical 6] R ₁ represents one or more groups selected from

[Chemical 7] Represents one or more groups selected from In the formula, X represents a hydrogen atom or a chlorine atom, and the structural unit [(II) + (III)]
And the structural units (IV) are substantially equimolar. )

The melting point of the polyester and / or polyesteramide is preferably 200 ° C. or higher and 350 ° C. or lower. The structural unit (I) is a structural unit of polyester produced from p-hydroxybenzoic acid,
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, 2, Structural units produced from aromatic dihydroxy compounds selected from 2-bis (4-hydroxyphenyl) propane and 4,4′-dihydroxydiphenyl ether, structural units (III) are structural units produced from ethylene glycol, structural units (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'-
Structural units formed from an aromatic dicarboxylic acid selected from dicarboxylic acid and diphenyl ether dicarboxylic acid are shown below. Of these, R ₁

Embedded image And R ₂ is

[Chemical 9] Are particularly preferred. As the liquid crystal polyesteramide, a liquid crystal polyesteramide containing a p-iminophenoxy unit formed from p-aminophenol in addition to the above structural units (I) to (IV) is preferable.

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

That is, the above structural units (I), (III), (I
In the case of a copolymer consisting of V), the structural unit (I) is preferably 40 to 95 mol% of [(I) + (III)],
˜95 mol% is more preferred. Further, the structural unit (IV) is substantially equimolar to the structural unit (III).

Further, the above structural units (I), (II), (III),
In the case of a copolymer composed of (IV), the above structural unit [(I) +
(II)] is preferably 60 to 95 mol% of [(I) + (II) + (III)], and more preferably 85 to 93 mol%. The structural unit (III) is preferably 40 to 5 mol% of [(I) + (II) + (III)], more preferably 15 to 7 mol%. Also,
The molar ratio of the 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. The structural unit (IV) is substantially equimolar to the structural unit [(II) + (III)].

In addition to the components constituting the above structural units (I) to (IV), aromatic dicarboxylic acids such as 3,3'-diphenyldicarboxylic acid and 2,2'-diphenyldicarboxylic acid, adipic acid, azelaic acid and sebacine. Acids, aliphatic dicarboxylic acids such as dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone,
4,4'-dihydroxydiphenyl sulfone, 4,4 '
-Aromatic diols such as dihydroxydiphenyl sulfide and 4,4'-dihydroxybenzophenone, 1,4-
Butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol,
Aliphatic and alicyclic diols such as 1,4-cyclohexanedimethanol and aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, and p-aminophenol and p-aminobenzoic acid Further copolymerization can be carried out in a small proportion within a range that does not impair the object of the present invention.

The liquid crystalline resin of the present invention is required to have a heat of fusion of polymer of 1.5 J / g or more as determined by differential calorimetry, more preferably 1.8 J / g, and particularly 2. It is preferably 2 J / g or more, and the upper limit is not specified, but 3.0 J from the viewpoint of practicality.
/ G or less is preferable.

Even when the composition ratio of the structural units (I) to (IV) satisfies the above preferable conditions, the composition distribution of the polymer,
When the heat of fusion is less than 1.5 J / g due to the difference in homogeneity, the molded article has insufficient chemical resistance and hydrolysis resistance, and the object of the present invention cannot be achieved.

The term "heat of fusion" used herein means that after measuring the endothermic peak temperature (Tm1) observed when the polymer is measured at room temperature to 40 ° C./min in the differential calorimetry, T
After being held at a temperature of m1 + 20 ° C. for 5 minutes, the temperature was once cooled to room temperature under a temperature lowering condition of 20 ° C./min, and then the endothermic peak temperature (T
It means the amount of heat of the endothermic peak obtained from the peak of m2).

The method for producing a liquid crystalline resin having the above heat of fusion is not particularly limited as long as it has the above heat of fusion.
Depending on the production method, even if they have the same skeleton, the crystallinity is low due to randomness, etc., and only those with a low amount of heat of fusion may be obtained, so the resin is produced so that the crystallinity is sufficiently high. This is very important. In terms of reaction mechanism, it can be produced according to a known polycondensation method of polyester or polyesteramide.

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

(1) p-acetoxybenzoic acid, 4,4 '
-Diacylated aromatic dihydroxy compounds such as diacetoxybiphenyl and diacetoxybenzene, aromatic dicarboxylic acids such as terephthalic acid, and polyester polymers such as polyethylene terephthalate, oligomers, and aromatics such as bis (β-hydroxyethyl) terephthalate A method for producing a bis (β-hydroxyethyl) ester of a dicarboxylic acid group by a deacetic acid polycondensation reaction.

(2) p-hydroxybenzoic acid, 4,4 '
-Aromatic dihydroxy compounds such as dihydroxybiphenyl and hydroquinone, aromatic dicarboxylic acids such as acetic anhydride and terephthalic acid, polyester polymers such as polyethylene terephthalate, oligomers or aromatic dicarboxylic acids such as bis (β-hydroxyethyl) terephthalate And a bis (β-hydroxyethyl) ester of the above are produced by deacetic acid polycondensation reaction.

(3) A method of using 1,2-bis (4-hydroxybenzoyl) ethane as a part of the starting material in the production method of (1) or (2) as described in JP-A-3-59024.

In order to produce a liquid crystalline resin having a heat of fusion specified in the present invention by the deacetic acid polymerization reaction as described above, acetylation is mainly used in the first container (hereinafter referred to as a reaction can). When the above reaction is carried out and this reaction product is transferred into the second container (hereinafter referred to as a polymerization vessel) through the liquid transfer port and polymerization is carried out in the polymerization vessel, the amount of distillate distilled from the reaction vessel is theoretical It is preferable to transfer the reaction product to the polymerization vessel after distilling 80% or more of the discharged amount. Also, when decompressing at the final polymerization temperature, 1
Between 00 and 600 Torr, preferably 200-50
It is preferable to maintain the degree of reduced pressure at 0 Torr for 15 minutes or more. Further, in the batch type continuous polymerization method in which after the molten polymer is discharged, the next raw material is charged into the same polymerization vessel and the polymerization is repeated, when the polymer is discharged, the residual polymer amount is 30 kg per 1 m ³ of the inner volume of the polymerization vessel. It is preferable to add the following raw materials in the following manner.

Further, when the raw materials are charged, it is preferable to charge the dicarboxylic acid component in excess with respect to the diol component, and in particular, the amount of the dicarboxylic acid is more than 1 mol and 1.3 mol or less per 1 mol of the diol component. preferable.

Further, the structural units (I), (III) and
In the case of the liquid crystal polyester composed of (IV), it is preferable to use 1,2-bis (4-hydroxybenzoyl) ethane for multistage polymerization, and the structural units (I), (II), (II
In the case of the liquid crystal polyester composed of I) and (IV), it is preferable to charge the dicarboxylic acid component in excess with respect to the dihydroxy component.

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

Some of the above-mentioned liquid crystalline resins for use in the present invention are those capable of measuring the logarithmic viscosity in pentafluorophenol, and in that case, the concentration is 6 at a concentration of 0.1 g / dl.
The value measured at 0 ° C is preferably 0.3 dl / g or more, and when the structural unit (III) is contained, it is 0.5 to 3.0 dl / g,
1.0 to 15.0 dl when the structural unit (III) is not included
/ G is particularly preferred.

Further, the liquid crystalline resin in the present invention is 10 to
20,000 poise is preferred, especially 20 to 10,000
0 poise is more preferred.

The melt viscosity is the melting point (Tm) +10.
It is a value measured by a Koka type flow tester under conditions of a shear rate of 1,000 (1 / sec) under conditions of ° C.

Particularly, it is possible to impart good flame retardancy by adding an organic flame retardant to the copolyester of the present invention.

The organic flame retardant which can be used in the present invention is an organic bromine compound and / or an organic phosphorus compound.

The organic bromine compound has a bromine atom in the molecule, and 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-methylstyrene And halogenated polymers and oligomers thereof, or mixtures thereof. Among them, ethylene bis- (tetrabromophthalimide), brominated epoxy oligomer or polymer, brominated polystyrene, crosslinked brominated polystyrene, brominated polyphenylene ether and bromine. Brominated polycarbonate is preferable, and ethylene bis- (tetrabromophthalimide), brominated polystyrene, and brominated polycarbonate can be particularly preferably used.

The amount of these organic bromine compounds added is preferably 0.2 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, per 100 parts by weight of the liquid crystalline resin. Since there is a close relationship with the copolymerization amount of the structural unit formed from the aliphatic monomer of, for example, the structural unit (III) in the liquid crystalline polyester, the following addition amounts are preferable. That is, the addition amount of the organic bromine compound is 100 units of the structural unit generated from the aliphatic monomer in the liquid crystalline resin, for example, the structural unit (III) in the liquid crystalline polyester.
60 to 280 parts by weight is preferable with respect to parts by weight, and 100
˜200 parts by weight is particularly preferred.

On the other hand, the organic phosphorus compound has a phosphorus atom in the molecule, and is a compound synthesized from phosphoric acid, phosphorous acid, phosphonic acid, compounds such as phosphine, phosphine oxide, and phosphorane, and compounds of the following structural formulas. It is a compound and a polymer containing these compounds as at least one component.

[0033]

[Chemical 10] (Here, R ₃ represents a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms and / or a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms).

[0034]

Examples of this polymer include polymers having the following structural units.

[0036]

[Chemical 11] (Here, R ₄ represents a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms and / or a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and Ar represents a trivalent group having 6 to 20 carbon atoms. Represents an aromatic hydrocarbon group).

[0037]

The most preferable organic phosphorus compound among them is the following polymer.

[0039]

[Chemical 12] A part of these organic phosphorus compounds may be a metal salt.

The amount of these organic phosphorus compounds added is 0.2 to 30 parts by weight, preferably 0.5 to 15 parts by weight, per 100 parts by weight of the liquid crystalline resin, and 100 parts by weight of the structural unit (III).
2 to 150 parts by weight is preferable with respect to parts by weight, 10 to 1
10 parts by weight is more preferable.

In the present invention, the organic phosphorus compound may be an organic phosphorus compound containing a bromine atom such as a polymer having the following structural unit.

[0042]

[Chemical 13] Moreover, mechanical properties and heat resistance can be further improved by adding a reinforcing agent and a filler to the liquid crystalline resin of the present invention.

When the reinforcing agent and the filler are added, the addition amount thereof is preferably 200 parts by weight or less, and particularly preferably 15 to 150 parts by weight, relative to 100 parts by weight of the liquid crystalline resin.

Examples of reinforcing agents and fillers that can be used in the present invention are glass fiber, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, gypsum fiber, brass fiber, stainless fiber, steel fiber, ceramic fiber, boron. Whisker fiber, asbestos fiber, graphite, mica, talc, silica, calcium carbonate, glass beads, glass flakes, glass microballoons,
Examples thereof include fibrous, powdery, granular or plate-like inorganic fillers such as clay, wollastonite, titanium oxide and molybdenum disulfide. Further, as these reinforcing agents and fillers, those treated with a coupling agent such as a silane type or titanate type, or other surface treatment agent may be used.

Further, the liquid crystalline resin of the present invention contains an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, and the like) to the extent that the object of the present invention is not impaired.
Phosphites and their substitution products), UV 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 and polyethylene), dyes (eg nitrosine) and pigments (eg cadmium sulfide, phthalocyanine, carbon black etc.), plasticizers,
Conventional additives such as 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 melt-kneaded at a temperature of ˜350 ° C. to obtain a composition.

The liquid crystalline resin of the present invention thus obtained has excellent melt fluidity and optical anisotropy, and has excellent heat resistance, chemical resistance, hydrolysis resistance, and mechanical properties obtained by ordinary molding methods. Can be molded into a three-dimensional molded product having the above-mentioned properties. Above all, an extremely practical injection-molded product can be obtained by injection molding due to its excellent crystallinity.
Further, it is also possible to process other sheets, container pipes, etc., and as molded articles obtained by molding such as injection molding, for example, various gears, various cases,
Sensors, LED lamps, connectors, sockets, resistors, relay case switch coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners,
Speakers, microphones, headphones, small motors, magnetic head bases, power modules, housings, semiconductors, liquid crystal display parts, FDD carriages, FDD chassis, HDD parts, motor brush holders, parabolic antennas, computer-related parts, etc. Electronic 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,
Household and office electrical product parts represented by refrigerator parts, air conditioner parts, typewriter parts, word processor parts, office computer related parts, telephone related parts, facsimile related parts copier related parts, cleaning jigs, oilless bearings, Various bearings such as stern bearings, underwater bearings, mechanical parts such as motor parts, lighters and typewriters, optical devices such as microscopes, binoculars, cameras and watches, precision machine parts; alternator terminals, Alternator connector, I
C regulator, potentiometer base for light deer, various valves such as 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 butt wear sensor, Air conditioner thermostat base, Heating hot air flow control valve, Radiator motor Brush holders, water pump impellers, turbine vanes, wiper motor related parts, dust reviewers , Starter switch, starter relay, transmission wire harness,
Window washer nozzles, air conditioner panel switch substrates, coils for fuel-related electromagnetic valves, connectors for fuses, horn terminals, insulation plates for electrical components, step motor rotors, lamp sockets, lamp reflectors,
It is useful for automobile / vehicle related parts such as lamp housing, brake piston, solenoid bobbin, engine oil filter, ignition device case, and other various applications.

[0048]

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

[0049] Example 1 vertical and horizontal reactor which ratio the scraping-down direction of the helical ribbon blade into the polymerization apparatus having an inner volume of 0.1 m ³ of 2.5 is provided with a stirrer fitted to a height of 0.035 m ³ Was polymerized as follows using a polymerization can for polycondensation.

P-Hydroxybenzoic acid 22.1 was added to the reactor.
kg, 4,4'-dihydroxybiphenyl 2.79k
g, polyethylene terephthalate 4.8 kg, terephthalic acid 2.61 kg (1.05 times moles based on 4,4′-dihydroxybiphenyl) and acetic anhydride 21.34 k
g in a reactor can be heated to 130 to 2 over 5 hours.
The temperature was raised to 50 ° C., and stirring was continued at 250 ° C. for 30 minutes. The amount of distillate at this point was 20.30 kg, which was 8% of the theoretical amount.
It was 2%. After that, the reaction product was transferred to a polymerization vessel, the temperature inside the vessel was adjusted to 250 to 315 ° C over 2 hours, and the polymerization vessel was cooled to 7 ° C.
Reduce the pressure to 250 Torr over 0 minutes and reduce the pressure to 250
Stirring was continued for 1 hour while keeping at Torr. Then 50
The pressure was reduced to 1 Torr over minutes, and stirring was continued for 2 hours to complete polycondensation. After that, the inside of the polymerization vessel was pressurized, and then the polymer was discharged in a strand shape through the die.

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

[0052]

Embedded image k / l / m / n = 80 / 7.5 / 12.5 / 20

The melting point and the heat of fusion of this liquid crystalline polyester were measured under the above-mentioned conditions by using DSC-7 type manufactured by Perkin Elmer Co., and 2.25 J / at 313 ° C.
g. The logarithmic viscosity of this polymer was 1.82d.
1 / g (measured at 60 ° C. in pentafluorophenol at a concentration of 0.1 g / dl).

The obtained pellets were subjected to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 320 ° C. and a mold temperature of 90 ° C. to be 3.2.
A mm-thick ASTM No. 1 dumbbell test piece was molded. Using this molded product, the chemical resistance (room temperature, 1000 hours, immersion in 1,2 dichloroethane) was tested to measure the tensile strength retention rate. Table 1 shows the results.

With respect to 100 parts by weight of this polymer, 10 parts by weight of polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer (bromine content 59%) and an average fiber diameter of about 1 are used.
After dry-blending 45 parts by weight of glass fiber of 0 μm and average fiber length of 3 mm, 31 by a 30 mmφ twin-screw extruder
Melt kneading-pelletizing at 0 ° C.

The pellets thus obtained were subjected to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 320 ° C. and a mold temperature of 90 ° C. to 3.2.
A mm-thick ASTM No. 1 dumbbell test piece was molded. Using this molded product, hydrolysis resistance (100
C., 10 days immersion in water) and the tensile strength retention rate was measured. Table 1 shows the results.

Comparative Example 1 Using the same polymerization apparatus as in Example 1, 22.1 kg of p-hydroxybenzoic acid, 2.79 kg of 4,4′-dihydroxybiphenyl, 4.8 kg of polyethylene terephthalate and 2. 37 kg (0.95 times mol relative to 4,4′-dihydroxybiphenyl) and 21.34 kg of acetic anhydride were charged, and the temperature inside the reaction vessel was adjusted to 130 to 230 ° C. over 5 hours, and the mixture was stirred at 230 ° C. for 30 minutes. Continued. The amount of distillate at this point was 18.32 kg, which was 74% of the theoretical amount of distillate. After that, the reaction product was transferred to a polymerization vessel and the temperature inside the vessel was adjusted to 230 to 31 over 2 hours.
Bring the temperature to 5 ° C, and then take 90 minutes to bring the polymerization vessel to 1.0 Torr.
The pressure was reduced to, and stirring was continued at 315 ° C. for 2 hours to complete polycondensation. After that, the inside of the polymerization vessel was pressurized, and then the polymer was discharged in a strand shape through the die. The melting point and the heat of fusion of the obtained liquid crystalline polyester were measured in the same manner as in Example 1 and found to be 1.35 J / g at 315 ° C. The logarithmic viscosity of this polymer was 1.80 dl / g. This polymer was molded in the same manner as in Example 1 and evaluated for chemical resistance. Table 1 shows the results.

With respect to 100 parts by weight of this polymer, 10 parts by weight of polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer (bromine content 59%) and an average fiber diameter of about 1 are used.
Forty-five parts by weight of glass fiber of 0 μm and average fiber length of 3 mm was melt-kneaded and pelletized in the same manner as in Example 1 to evaluate hydrolysis resistance. Table 1 shows the results.

Example 2 Using the same polymerization apparatus as in Example 1, terephthalic acid 12.
46 kg, 1,2-bis (4-hydroxybenzoyl)
22.67 kg of ethane and 8.42 kg of acetic anhydride were charged, and the temperature inside the reaction vessel was 130 to 250 ° C over 5 hours.
And continued stirring at 250 ° C. for 30 minutes. The amount of distillate at this point was 8.01 kg, which was 82% of the theoretical amount of distillate. After that, the reaction product was transferred to a polymerization vessel, the temperature inside the vessel was adjusted to 250 to 270 ° C. over 2 hours, the polymerization vessel was depressurized to 250 Torr over 70 minutes, and the depressurization degree was 250 Torr.
The stirring was continued for 1 hour. Thereafter, the pressure was reduced to 1 Torr over 50 minutes, the polymerization vessel was reduced to 1.0 Torr, and stirring was continued at 270 ° C. for 2 hours to complete polycondensation.
After that, the inside of the polymerization vessel was pressurized, and then the polymer was discharged in a strand shape through the die.

Then again, the obtained polymer 21.62k
g, p-acetoxybenzoic acid 18.02 kg,
Stirring was carried out at 250 ° C. for 3 hours. The amount of distillate at this point was 4.86 kg, which was 81% of the theoretical amount of distillate.
After that, the reaction product was transferred to a polymerization vessel, the temperature inside the vessel was adjusted to 250 to 290 ° C over 2 hours, and the polymerization vessel was heated to 25 minutes over 70 minutes.
The pressure was reduced to 0 Torr, and stirring was continued for 1 hour while maintaining the degree of reduced pressure at 250 Torr. 50 minutes later 1 To
depressurize to rr, depressurize the polymerization vessel to 1.0 Torr,
Stirring was continued at 290 ° C. for 2 hours to complete polycondensation. After that, the inside of the polymerization vessel was pressurized, and then the polymer was discharged in a strand shape through the die.

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

[0062]

[Chemical 15] k / l / m = 80/20/20

The melting point and the heat of fusion of the obtained liquid crystalline polyester were measured in the same manner as in Example 1 and found to be 1.54 J / g at 268 ° C. The logarithmic viscosity of this polymer is 0.
It was 75 dl / g. This polymer was molded in the same manner as in Example 1 and evaluated for chemical resistance. Table 1 shows the results.

With respect to 100 parts by weight of this polymer, 10 parts by weight of polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer (bromine content 59%) and an average fiber diameter of about 1
Forty-five parts by weight of glass fiber of 0 μm and average fiber length of 3 mm was melt-kneaded and pelletized in the same manner as in Example 1 to evaluate hydrolysis resistance. Table 1 shows the results.

Comparative Example 2 Using the same apparatus as in Example 1, deacetic acid polymerization was carried out under the following conditions. First, 28.8 p-acetoxybenzoic acid was placed in a reaction can.
3 kg and polyethylene terephthalate 7.69 kg
Was charged and stirred at 240 ° C. for 3 hours. The amount of distillate up to this point was 6.82 kg, which was 71% of the theoretical amount.
%Met. After that, the reaction product was transferred to a polymerization vessel, the temperature inside the vessel was adjusted to 240 to 300 ° C over 2 hours, and the polymerization vessel was heated to 90 ° C.
The pressure was reduced to 1 Torr over minutes. Then, stirring was continued for 1 hour to complete polycondensation.

The melting point and heat of fusion of the obtained liquid crystalline polyester were measured in the same manner as in Example 1 and found to be 0.81 J / g at 296 ° C. The logarithmic viscosity of this polymer is 0.
It was 70 dl / g. This polymer was molded in the same manner as in Example 1 and evaluated for chemical resistance. Table 1 shows the results. This polymer was molded in the same manner as in Example 1 and evaluated for chemical resistance. Table 1 shows the results.

With respect to 100 parts by weight of this polymer, 10 parts by weight of polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer (bromine content 59%) and an average fiber diameter of about 1
Forty-five parts by weight of glass fiber of 0 μm and average fiber length of 3 mm was melt-kneaded and pelletized in the same manner as in Example 1 to evaluate hydrolysis resistance. Table 1 shows the results.

Example 3 Using the same polymerization apparatus as in Example 1, 16.58 kg of p-hydroxybenzoic acid, 15.05 kg of 2-hydroxy-6-naphthoic acid and 22.44 kg of acetic anhydride were charged, and the reaction was carried out for 5 hours. The temperature inside the reaction can was adjusted to 130 to 250 ° C., and stirring was continued at 250 ° C. for 30 minutes. The amount of distillate at this point was 21.09 kg, which was 81% of the theoretical amount of distillate. Then, the reaction product was transferred to a polymerization vessel, the temperature inside the vessel was adjusted to 250 to 280 ° C. over 2 hours, the polymerization vessel was depressurized to 250 Torr over 70 minutes, and the depressurization degree was 250 Torr.
The stirring was continued for 1 hour. Then, the pressure was reduced to 1 Torr over 50 minutes, the pressure of the polymerization vessel was reduced to 1.0 Torr, and stirring was continued at 280 ° C. for 2 hours to complete polycondensation.
After that, the inside of the polymerization vessel was pressurized, and then the polymer was discharged in a strand shape through the die.

Then again, the obtained polymer 14.01k
g, p-Hydroxybenzoic acid (6.63 kg) and acetic anhydride (5.39 kg) were charged, the temperature inside the reaction vessel was set to 130 to 250 ° C over 5 hours, and stirring was continued at 250 ° C for 30 minutes. The amount of distillate at this point was 5.13 kg, which was 82% of the theoretical amount of distillate. After that, the reaction product was transferred to a polymerization vessel, and the temperature inside the vessel was adjusted to 250 to 310 ° C over 2 hours.
The polymerization vessel was depressurized to 250 Torr over 70 minutes, and stirring was continued for 1 hour while maintaining the degree of depressurization at 250 Torr.
Thereafter, the pressure was reduced to 1 Torr over 50 minutes, the pressure of the polymerization vessel was reduced to 1.0 Torr, and stirring was continued at 310 ° C. for 2 hours to complete polycondensation. After that, the inside of the polymerization vessel was pressurized, and then the polymer was discharged in a strand shape through the die.

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

[0071]

Embedded image k / l = 73/27

The melting point and heat of fusion of the obtained liquid crystalline polyester were measured in the same manner as in Example 1 and found to be 1.62 J / g at 280 ° C. The logarithmic viscosity of this polymer is 5.
It was 34 dl / g. This polymer was molded in the same manner as in Example 1 and evaluated for chemical resistance. Table 1 shows the results.

With respect to 100 parts by weight of this polymer, 10 parts by weight of polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer (bromine content 59%) and an average fiber diameter of about 1
Forty-five parts by weight of glass fiber of 0 μm and average fiber length of 3 mm was melt-kneaded and pelletized in the same manner as in Example 1 to evaluate hydrolysis resistance. Table 1 shows the results.

Comparative Example 3 Using the same apparatus as in Example 1, deacetic acid polymerization was carried out under the following conditions. First, p-hydroxybenzoic acid 20.1 was placed in a reaction can.
7 kg, 2-hydroxy-6-naphthoic acid 10.16 k
g and 22.44 kg of acetic anhydride were charged and the temperature was adjusted to 130 to 230 ° C. over 5 hours. The amount of distillate up to this point was 19.00 kg, which was 73% of the theoretical amount of distillate.
After that, the reaction product was transferred to a polymerization vessel, the temperature inside the vessel was adjusted to 230 to 330 ° C over 2 hours, and the polymerization vessel was heated to 1T over 90 minutes.
The pressure was reduced to orr. Then, stirring was continued for 1 hour to complete polycondensation.

The melting point and heat of fusion of the obtained liquid crystalline polyester were measured in the same manner as in Example 1 and found to be 1.08 J / g at 280 ° C. The logarithmic viscosity of this polymer is 5.
It was 48 dl / g. This polymer was molded in the same manner as in Example 1 and evaluated for chemical resistance. Table 1 shows the results.

With respect to 100 parts by weight of this polymer, 10 parts by weight of polydibrominated styrene obtained by polymerizing a dibrominated polystyrene monomer (bromine content 59%) and an average fiber diameter of about 1
Forty-five parts by weight of glass fiber of 0 μm and average fiber length of 3 mm was melt-kneaded and pelletized in the same manner as in Example 1 to evaluate hydrolysis resistance. Table 1 shows the results.

[0077]

[Table 1]

[0078]

INDUSTRIAL APPLICABILITY The present invention can be obtained only by melt polymerization and has excellent melt fluidity and optical anisotropy, and is excellent in heat resistance, chemical resistance, hydrolysis resistance and mechanical properties by ordinary molding methods. It is possible to obtain a liquid crystalline resin having a desired property and an injection molded product thereof.

Claims (4)

[Claims] 1. A liquid crystalline resin comprising a liquid crystalline polyester or a liquid crystalline polyesteramide, wherein the polymer has a heat of fusion of 1.5 J / g or more as determined by differential calorimetric measurement. 2. The liquid crystalline resin according to claim 1, wherein the liquid crystalline resin contains the following structural unit (I). Embedded image 3. The liquid crystalline resin is a liquid crystalline polyester comprising the following structural units (I), (II), (III) and (IV), or (I), (III) and (IV). Item 2. The liquid crystalline resin according to item 2. Embedded image (However, in the formula, R ₁ is R ₁ represents one or more groups selected from Represents one or more groups selected from In the formula, X represents a hydrogen atom or a chlorine atom, and the structural unit [(II) + (III)] and the structural unit (IV) are substantially equimolar). 4. An injection-molded article obtained by injection-molding the liquid crystalline resin according to claim 1.