JPH06157921A - Production of resin composition and production of resin composition-molded product - Google Patents

Abstract

PURPOSE:To obtain a resin composition excellent in mechanical properties, heat resistance and moldability, useful for electrical and electronic parts, etc., by melt-kneading a resin with liquid crystal character capable of forming anisotropic molten phase together with a thermoplastic resin at specified proportion followed by heat-treating. CONSTITUTION:(A) 1-50wt.% of a resin with liquid crystal characteristic capable of forming anisotropic molten phase (e.g. a liquid crystal polyester) and (B) 99-50wt.% of a thermoplastic resin such as polybutylene terephthalate are kneaded in a molten state and then heat-treated to obtain the objective resin composition. The objective molded product can be obtained by molding this composition at a temperature lower than the initiation temperature for the liquid crystal formation for the component A but higher than the melting point of the component B or the moldable lower limit temperature of the component B.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the production of a resin composition comprising a liquid crystalline resin and a thermoplastic resin, which are useful as electric / electronic equipment parts, automobile parts, mechanical parts, etc. and which have excellent mechanical properties, heat resistance and moldability. The present invention relates to a method and a method for producing a resin composition molded article.

[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 properties have been developed. Among them, an optically anisotropic liquid crystal characterized by parallel arrangement of molecular chains. Resin has attracted attention because it has excellent fluidity and mechanical properties. However,
At present, the applications are limited because the molding shrinkage and mechanical properties are different in the direction perpendicular to the molecular chain orientation direction and the cost is high. On the other hand, it is known that many thermoplastic resins are not necessarily sufficient in mechanical properties and heat resistance as compared with liquid crystal resins.

Therefore, in order to solve the disadvantages of both, a blend of a liquid crystalline resin and a thermoplastic resin has been attracting attention (for example, JP-A-57-25354). Further, in order to improve the mechanical properties of the blend, a thermoplastic resin having a melting point lower than the liquid crystal starting temperature of the liquid crystalline resin by 10 ° C. or more is blended at a liquid crystal starting temperature or higher, and molded at a liquid crystal starting temperature or lower. A method for maintaining the alignment state of the liquid crystalline resin and improving the skin-core structure is proposed (Japanese Patent Laid-Open No. 3-24911).

[0004]

However, with this method, the physical properties and orientation of the liquid crystalline resin in the composition are not sufficient, and no significant improvement in physical properties is observed. Further, there is a problem that only liquid crystal resins having a liquid crystal starting temperature higher than the melting point of the thermoplastic resin by 10 ° C. or more can be used.

An object of the present invention is to solve the above problems and to produce a resin composition excellent in mechanical properties and heat resistance and to produce a molded article.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by heat-treating a melt-kneaded composition.

In the present invention, it is important to melt-knead the liquid crystalline resin and the thermoplastic resin and then heat-treat them, whereby a good alignment state of the liquid crystalline resin is maintained and a molded product obtained from the composition is obtained. The mechanical properties and heat resistance of can be greatly improved.

That is, the present invention comprises (A) 1 to 50% by weight of a liquid crystalline resin capable of forming an anisotropic melt phase, and (B)
It is intended to provide a method for producing a resin composition, characterized in that 99 to 50% by weight of a thermoplastic resin is melt-kneaded and then heat treated.

The compounds specifically used in the present invention will be described in detail below.

The liquid crystalline resin (A) used in the present invention is a resin capable of forming an anisotropic molten phase, which is generally called liquid crystal polyester, liquid crystal polyester amide, or the like. There is no particular limitation. Among them, liquid crystal polyesters are preferable, for example, p-hydroxybenzoic acid / polyethylene terephthalate type liquid crystal polyester, p-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid type liquid crystal polyester, p-hydroxybenzoic acid / 4,4′- Dihydroxybiphenyl / terephthalic acid /
Examples include isophthalic acid-based liquid crystal polyesters, among which the following structural units (I), (II), (IV) or (I), (II),
A liquid crystal polyester composed of (III) and (IV) is preferable.

[0011]

[Chemical 4] (However, R1 is

[Chemical 5] R1 represents one or more groups selected from

[Chemical 6] 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, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane and 4,4'- A structural unit formed from an aromatic dihydroxy compound selected from dihydroxydiphenyl ether, a structural unit (III) is a structural unit formed from ethylene glycol, and a structural unit (IV) is terephthalic acid, isophthalic acid, 4,4'-diphenyl Carboxylic 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, particularly when the structural unit (III) is included, R 1 is

[Chemical 7] Is 70% by mole or more of the structural unit (II), and R2 is

[Chemical 8] Particularly preferably those having 70 mol% or more of the structural unit (IV).

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, when the structural unit (III) is included, the structural unit [(I) + (II)] is [(I) + (II) + (III) in terms of heat resistance and mechanical properties.
60 to 95 mol% is preferable, and 70 to 92 mol%
Is more preferable. In addition, the structural unit (III) is [(I) + (II)
+ (III)] is preferably 40 to 5 mol%, more preferably 30 to 8 mol%. The molar ratio of structural unit (I) / (II) is preferably 75 from the viewpoint of the balance between fluidity and mechanical properties.
/ 25 to 95/5, and more preferably 78/22 to
It is 93/7. Further, the structural unit (IV) is a structural unit [(II)
+ (III)] is substantially equimolar.

On the other hand, when the structural unit (III) is not contained, the structural unit (I) is [(I) + (II)] from the viewpoint of fluidity.
Is preferably 40 to 90 mol%, and 60 to 88
It is particularly preferable that the amount is mol%, and the structural unit (IV) is substantially equimolar to the structural unit (II).

In polycondensation of the above preferred liquid crystalline polyester, 3,3'-diphenyldicarboxylic acid, 2,2 'is added in addition to the components constituting the structural units (I) to (IV).
An aromatic dicarboxylic acid such as diphenyldicarboxylic acid,
Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, methylhydroquinone, 4,4'-dihydroxydiphenyl sulfone, 4,4 ' -Dihydroxydiphenyl sulfide, aromatic diol such as 4,4'-dihydroxybenzophenone, 1,4-butanediol, 1,6-
Hexanediol, neopentyl glycol, 1,4-
Aliphatic and alicyclic diols such as cyclohexanediol and 1,4-cyclohexanedimethanol, and aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, and p-aminophenol and p-aminobenzoic acid An acid or the like may be copolymerized in an amount that does not impair the object of the present invention.

The method for producing the liquid crystalline resin (A) in the present invention is not particularly limited. For example, when a liquid crystal polyester is produced, it can be produced according to a known polyester polycondensation method. Specifically, the following methods (1) to (5) are exemplified. Among the liquid crystal polyesters that can be preferably used, when the structural unit (III) is not included,
(4) When the structural unit (III) is included, the production method of (5) is preferable.

(1) p-acetoxybenzoic acid and 4,
A method for producing a diacylated aromatic dihydroxy compound such as 4′-diacetoxybiphenyl and an aromatic dicarboxylic acid such as terephthalic acid by deacetic acid condensation polymerization reaction.

(2) p-hydroxybenzoic acid and 4,
A method in which an aromatic dihydroxy compound such as 4'-dihydroxybiphenyl and an aromatic dicarboxylic acid such as terephthalic acid are reacted with acetic anhydride to acylate a phenolic hydroxyl group, and then a deacetic acid polycondensation reaction is performed.

(3) A method for producing a phenyl ester of p-hydroxybenzoic acid and an aromatic dihydroxy compound such as 4,4'-dihydroxybiphenyl and a diphenyl ester of an aromatic dicarboxylic acid such as terephthalic acid by a dephenol polycondensation reaction. .

(4) Aromatic dicarboxylic acids such as p-hydroxybenzoic acid and terephthalic acid are reacted with a predetermined amount of diphenyl carbonate to form diphenyl esters, and then aromatic dihydroxy such as 4,4'-dihydroxybiphenyl. A method of producing a compound by adding a compound and performing a dephenol polycondensation reaction.

(5) Polyester polymers such as polyethylene terephthalate, oligomers or bis (β-
A method for producing by the method (1) or (2) in the presence of a bis (β-hydroxyethyl) ester of an aromatic dicarboxylic acid such as hydroxyethyl) terephthalate.

Typical examples of the catalyst used in the polycondensation reaction include stannous acetate, tetrabutyl titanate, potassium acetate, antimony trioxide, metal compounds such as sodium acetate, magnesium, and the like. It is effective when

Some of the liquid crystalline resins (A) used in the present invention are those capable of measuring the logarithmic viscosity in pentafluorophenol, in which case they are measured at a concentration of 0.1 g / dl at 60 ° C. The value obtained is preferably 0.5 or more. In particular, when the structural unit (III) is included, it is 1.0 to 3.
When 0 dl / g does not contain the structural unit (III), 2.
0 to 10.0 dl / g is preferable.

The liquid crystalline resin (A) used in the present invention
The melt viscosity of is preferably 10 to 20,000 poise, and more preferably 20 to 10,000 poise. The melt viscosity is a value measured by a high-pressure capillary viscometer under the condition of melting point (Tm) + 10 ° C. and shear rate of 1,000 / sec.

Here, the melting point (Tm) means the endothermic peak temperature (Tm1) observed in the differential calorimetric measurement, which is observed when the temperature of the polymerized polymer is measured from room temperature to 20 ° C./min. , Tm1 + 20 ° C. for 5 minutes, then once cooled to room temperature under a temperature lowering condition of 20 ° C./min, and then measured again under a temperature rising condition of 20 ° C./min, the endothermic peak temperature (Tm2) observed Refers to. The liquid crystal starting temperature (TN) is the temperature at which opalescence is emitted under shear stress by heating the sample on a sample stage of a polarizing microscope.

Preferred specific examples of the thermoplastic resin (B) used in the present invention include crystalline resins such as polyester, polyamide, polyarylene sulfide, polyoxymethylene, polypropylene, polyethylene and polystyrene. In addition to these crystalline thermoplastic resins, amorphous resins such as polycarbonate, polyarylate, polyarylene oxide, and polyetherimide are also included. Among these resins, polyester is more preferable. The thermoplastic resin may be of one type or of two or more types. However, when the thermoplastic resin used is a crystalline resin, (melting point −10 ° C.) is preferably lower than or equal to the liquid crystal starting temperature of the liquid crystalline resin before heat treatment.
In the case of an amorphous resin, assuming that the temperature at which the melt viscosity at a shear rate of 1000 / sec is 10,000 poise or less is the lower limit temperature of moldability, (lower limit temperature of moldability-10 ° C) is the liquid crystalline resin before heat treatment. It is preferable that the temperature becomes equal to or lower than the liquid crystal starting temperature. By satisfying these conditions, the oriented structure in the composition is maintained very suitably, and the effect of improving mechanical properties becomes remarkable. The individual resins will be specifically described below.

The thermoplastic polyester is a thermoplastic polyester having an aromatic ring as a chain unit of the polymer, which is an aromatic dicarboxylic acid (or its ester-forming derivative) and a diol (or its ester-forming derivative). Is a polymer or copolymer obtained by a condensation reaction containing as a main component. Examples of the dicarboxylic acid used herein include terephthalic acid, isophthalic acid, phthalic acid, 2,
6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p
-Carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4'-biphenylcarboxylic acid, 4,4'-diphenylethercarboxylic acid, 1,2-bis (p-carboxyphenoxy) ethane, or an ester-forming derivative thereof. To be If it is 30 mol% or less, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecanedioic acid and dimer acid, 1,
It may be substituted with an alicyclic carboxylic acid such as 4-cyclohexanedicarboxylic acid or 1,3-cyclohexanedicarboxylic acid. As the diol component, an aliphatic diol having 2 to 10 carbon atoms, that is, ethylene glycol, propylene glycol, butylene glycol, 1,5-pentane glycol, decamethylene glycol, 3-methyl-
1,3-propenediol, neopentyl glycol,
Examples thereof include, but are not limited to, cyclohexanedimethanol and cyclohexanediol. Specific examples of preferable polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene-1,2-bis (phenoxy) ethane-4,
4'-dicarboxylate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, etc. and polyethylene terephthalate / isophthalate, polybutylene terephthalate / isophthalate, polybutylene terephthalate / sebacate, polybutylene terephthalate / Copolyesters such as decane dicarboxylate and poly-1,4-cyclohexane dimethylene terephthalate / isophthalate may be mentioned. Among these, preferred polyesters include polybutylene terephthalate, polyethylene terephthalate, and poly-1,4-cyclohexanedimethylene terephthalate. Furthermore, polybutylene terephthalate is more preferable. The logarithmic viscosity of polybutylene terephthalate is preferably 0.9 to 1.3, more preferably 0.92 to 1.25.
The logarithmic viscosity of polybutylene terephthalate is 25
It was determined by dividing the logarithm of the relative viscosity obtained by using a 0.5% orthochlorophenol solution at 0 ° C. by the concentration.

As the polyamide, polyamide obtained from ω-amino acid or ω-lactam, or dicarboxylic acid such as diamine or m-xylenediamine and adipic acid, sebacic acid, dodecanedioic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid. And homopolymers or copolymers obtained from the above, mixed polymers and the like. Preferred polyamides are homopolyamides such as nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, and adipic acid / terephthalic acid / hexamethylenediamine, adipic acid / 1,4-cyclohexanedicarboxylic acid / hexamethylenediamine, adipine. Examples thereof include copolyamides such as acid / 1,3-cyclohexanedicarboxylic acid / hexamethylenediamine, terephthalic acid / isophthalic acid / hexamethylenediamine / paraaminocyclohexylmethane.

The polyarylene sulfide is a bond of an aromatic ring and sulfur. Preferred polyarylene sulfides include polyparaphenylene sulfide, which may be partially branched.

Examples of the polyoxymethylene include polyoxymethylene homopolymers and copolymers whose main chain is composed mainly of oxymethylene chains.

The polypropylene includes not only a homopolymer of propylene but also a block or random copolymer obtained by copolymerizing propylene with other α-olefins (eg ethylene, butene-1 etc.), and further having an ethylene content of 50 mol. % Copolymer of ethylene and α-olefin having 3 or more carbon atoms (for example, ethylene / propylene copolymer, ethylene / butene-1 copolymer, etc.), ethylene, α-olefin having 3 or more carbon atoms and non-conjugated It may contain a copolymer composed of a diene (for example, ethylene / propylene / 1,4-hexadiene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / ethylidene norbornene copolymer). . Preferred polypropylenes include polypropylene homopolymers, propylene / ethylene copolymers having an ethylene content of 30 mol% or less, or ethylene-α-olefin copolymers having an ethylene content of 50 mol% or more, or ethylene and carbon. Α of number 3 or more
-A polypropylene homopolymer containing 50% by weight or less of an elastomeric copolymer composed of an olefin and a non-conjugated diene, and a propylene / ethylene copolymer having an ethylene content of 30 mol% or less. Those modified with an unsaturated carboxylic acid or a derivative thereof are more preferable. Examples of the unsaturated carboxylic acid to be modified include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, 5-norbornene-2,3-dicarboxylic acid, tetrahydrophthalic acid and dimer acid. Examples of the derivative include anhydrides, esters, amides, imides and salts of the above acids.

The polyethylene includes not only a homopolymer of ethylene but also a block or random copolymer obtained by copolymerizing ethylene with another α-olefin (eg propylene, butene-1). Those modified with the above-mentioned unsaturated carboxylic acid or its derivative are more preferable.

As the polystyrene, in addition to polystyrene homopolymer, HIPS (high impact polystyrene), A
S (acrylonitrile / styrene copolymer), ABS
(Acrylonitrile / butadiene / styrene copolymer), MBS (methyl methacrylate / butadiene / styrene copolymer) and the like.

As the polycarbonate or polyarylate, bis (4-hydroxyphenyl), bis (3,
5-dialkyl-4-hydroxyphenyl) or hydrocarbon derivatives having bis (3,5-dihalo-4-hydroxyphenyl) substitution are preferred.
Polycarbonates or polyarylates based on 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) are particularly preferred.

As the polyarylene oxide, poly (2,6-dimethyl-1,4-phenylene) ether,
2,6-dimethylphenol / 2,4,6-trimethylphenol copolymer, 2,6-dimethylphenol /
2,3,6-triethylphenol copolymer and the like can be mentioned. These can be used by modifying with unsaturated carboxylic acid or its derivative by graft reaction. The unsaturated carboxylic acid to be modified is acrylic acid, methacrylic acid,
Crotonic acid, maleic acid, fumaric acid, itaconic acid, 5
-Norbornene-2,3-dicarboxylic acid, tetrahydrophthalic acid, dimer acid and the like. Examples of the derivative include anhydrides, esters, amides, imides and salts of the above acids. Further, styrene resins such as polystyrene and high impact polystyrene can be added to the polyarylene oxide.

In producing the resin composition of the present invention, conventionally known additives such as polyester polymerization catalysts, heat-resistant agents, weathering agents, antistatic agents, dyes, colorants, crystal nucleating agents, flame retardants, etc. Inorganic fillers such as talc, clay, mica, calcium metasilicate, silica sand, glass beads, glass flakes, graphite, potash whiskers, gypsum fibers, reinforcing agents such as glass fibers, asbestos fibers, carbon fibers, etc. It is also possible to add.
It is also possible to add an epoxy compound, an oxazoline compound, a silane compound or the like as a compatibilizer.

Various methods can be applied as a method for melt-kneading the liquid crystalline resin (A) and the thermoplastic resin (B). Examples of the apparatus for melt-kneading include a mixing roll, a Banbury mixer, a kneader, an extruder, and the like. Among them, an extruder is preferable. As this extruder, either a single-screw extruder or a twin-screw extruder can be used, but it is particularly preferable to use a twin-screw extruder. The kneading temperature is preferably higher than the melting point of the thermoplastic resin (B) and higher than the liquid crystal starting temperature of the liquid crystalline resin (A), more preferably higher than the melting point of the liquid crystalline resin (A). .

A preferred method for making the resin composition of the present invention includes stretching the melt blended melt blend. By this operation, the orientation of the liquid crystalline resin (A) in the composition can be further increased. Various methods are conceivable for stretching the blend, and although not particularly limited, winding by a roller or stretching by a cutter is preferable. Here, when the ratio of the diameter of the stretched gut to the diameter of the extruded gut to the power of 3 is defined as the stretch ratio, this value is preferably 4 or more, and more preferably 5 or more.

The method of heat-treating the composition thus obtained is not particularly limited, and it can be carried out under normal pressure or reduced pressure. When it is carried out under normal pressure, it is preferably carried out under an inert gas from which water has been removed, for example, under a nitrogen or argon atmosphere. The heat treatment temperature may be any temperature equal to or lower than the melting point of the crystalline resin (B) (lower limit temperature of molding of the amorphous resin), but (the liquid crystal starting temperature of the liquid crystal resin (A) before the heat treatment −20). C.) or higher, and more preferably (liquid crystal start temperature before heat treatment of liquid crystalline resin (A) -10.degree. C.) or higher. The heat treatment conditions are preferably the same as the conditions in which the melting point of the liquid crystalline resin (A) to be used is increased by 2 ° C. or more when DSC measurement is performed alone, more preferably 5 ° C. or more, and further preferably The conditions are equivalent to the conditions of increasing by 10 ° C. or more. Although the heat treatment time is arbitrary, the liquid crystalline resin (A)
When measured alone, a time equivalent to the time required for the melting point to rise by 2 ° C. or higher is the minimum required. When the temperature rises by 2 ° C. or more, the elastic modulus of the liquid crystalline resin itself in the composition also rises, and a great effect can be expected. Further, when the liquid crystal starting temperature of the used liquid crystalline resin (A) is not higher than the melting point of the thermoplastic resin (B), the liquid crystal of the liquid crystalline resin (A) when the liquid crystalline resin (A) is heat-treated alone. The composition is preferably heat-treated under the condition that the starting temperature is not lower than the melting point of the thermoplastic resin (B).

When a molded product is obtained from the resin composition of the present invention, usual methods such as injection molding, extrusion molding and blow molding can be applied, but injection molding is particularly preferable. The molding temperature is preferably not higher than the liquid crystal starting temperature of the liquid crystalline resin (A) in the composition after heat treatment and not lower than the melting point of the thermoplastic resin (B). When molded at this temperature, the dispersed state after stretching is preferably maintained, the dispersed state hardly changes inside the test piece and the surface layer portion, and the physical property improving effect is exhibited.

[0040]

EXAMPLES The present invention will be described in more detail with reference to examples below, but these examples do not limit the scope of application of the present invention. In addition, the part in an Example represents a weight part.

Reference Example 1 833 parts by weight of p-hydroxybenzoic acid, 168 parts by weight of 4,4'-dihydroxybiphenyl, 880 parts by weight of acetic anhydride, 150 parts by weight of terephthalic acid and an intrinsic viscosity of about 0.
398 parts by weight of 6 dl / g polyethylene terephthalate was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and deacetic acid polycondensation was carried out under the following reaction conditions. 1 under nitrogen gas atmosphere
After reacting at 00 to 250 ° C for 1.5 hours, 290 ° C,
When the pressure was reduced to 0.5 mmHg for 2 hours and the reaction was further continued for 1.0 hour to complete the polycondensation, almost the theoretical amount of acetic acid was distilled off, and a liquid crystal polyester (A-1) having the following theoretical structural formula was obtained. Obtained.

[0042]

[Chemical 9] k / l / m / n = 67/10/23/33 The liquid crystal starting temperature of the obtained polyester (A-1) is 22.
The melting point was 0 ° C and the melting point was 254 ° C. The melt viscosity at 264 ° C. and a shear rate of 1000 / sec was 880 poise. This liquid crystal polyester (A-1) was used in a nitrogen atmosphere,
The melting point after heat treatment at normal pressure is shown in Table 1 together with the heat treatment conditions.

[0043]

[Table 1] Reference Example 2 870 parts by weight of p-hydroxybenzoic acid, 168 parts by weight of 4,4'-dihydroxybiphenyl, 914 parts by weight of acetic anhydride, 150 parts by weight of terephthalic acid and an intrinsic viscosity of about 0.
346 parts by weight of 6 dl / g polyethylene terephthalate was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and deacetic acid polycondensation was carried out under the following reaction conditions. 1 under nitrogen gas atmosphere
After reacting at 00 to 250 ° C for 1.5 hours, 290 ° C,
When the pressure was reduced to 0.5 mmHg for 2 hours and the reaction was further continued for 1.0 hour to complete the polycondensation, almost the theoretical amount of acetic acid was distilled off, and a liquid crystal polyester (A-2) having the following theoretical structural formula was obtained. Obtained.

[0044]

[Chemical 10] k / l / m / n = 70/10/20/30 The liquid crystal starting temperature of the obtained polyester (A-2) is 23.
The melting point was 5 ° C and the melting point was 267 ° C. The melt viscosity at 277 ° C. and a shear rate of 1000 / sec was 610 poise. This liquid crystal polyester (A-2) was used in a nitrogen atmosphere,
The melting point after heat treatment at normal pressure is shown in Table 2 together with the heat treatment conditions.

[0045]

[Table 2] Reference Example 3 932 parts by weight of p-hydroxybenzoic acid, 168 parts by weight of 4,4′-dihydroxybiphenyl, 960 parts by weight of acetic anhydride, 150 parts by weight of terephthalic acid and an intrinsic viscosity of about 0.
260 parts by weight of 6 dl / g polyethylene terephthalate was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and deacetic acid polycondensation was carried out under the following reaction conditions. For nitrogen gas atmosphere 1
After reacting at 00 to 250 ° C. for 5 hours and 250 to 300 ° C. for 1.5 hours, the pressure was reduced to 0.5 mmHg at 300 ° C. for 1 hour, and the reaction was further performed for 1.0 hour to complete polycondensation. Then, almost the theoretical amount of acetic acid was distilled off to obtain a liquid crystal polyester (A-3) having the following theoretical structural formula.

[0046]

[Chemical 11] k / l / m / n = 75/10/15/25 The liquid crystal starting temperature of the obtained polyester (A-3) is 27.
The melting point was 2 ° C and the melting point was 295 ° C. The melt viscosity at 305 ° C. and a shear rate of 1000 / sec was 910 poise. This liquid crystal polyester (A-3) was used in a nitrogen atmosphere,
The melting point after heat treatment at normal pressure is shown in Table 2 together with the heat treatment conditions.

[0047]

[Table 3] Examples 1 to 11, Comparative Examples 1 to 4 (A) Liquid crystal polyester A-1 or A-2, (B) Polybutylene terephthalate (Intrinsic viscosity 1.20 dl /
Each of g) was weighed in a predetermined amount and dry-blended. Two
Melt extrusion was performed by a 30 mmφ twin-screw extruder set at 70 ° C.
The melt blend after extrusion was stretched by pulling a cutter. The value obtained by raising the ratio of the diameter of the extruded gut to the diameter of the stretched gut to the third power was set to be 7 as the extension ratio. The gut was pelletized and heat-treated under a nitrogen atmosphere at normal pressure at the temperature and time shown in Table 4. The liquid crystal polyesters A-1 and A-2 used in advance were heat-treated under the same conditions to determine the temperature rise of the melting point (Table 1). With an injection molding machine set to a molding temperature and a mold temperature of 90 ° C. as shown in Table 4, 1 /
8 "thick x 1/2" wide x 5 "long test piece and 1 /
8 "thick ASTM No. 1 dumbbell was molded. Tensileon UTM-2 manufactured by Toyo Baldwin Co., Ltd. was used with a bending strength of 1/8" thick x 1/2 "width x 5" length test piece.
The measurement was performed under the conditions of a strain rate of 1 and a distance between spans of 50 mm. Further, according to ASTM D638, ASTM No. The tensile strength of one dumbbell was measured. Table 4 shows the results of these tests.

[0048]

[Table 4] From the results shown in Table 4 above, it can be seen that heat treatment improves both tensile strength and bending strength.

Examples 12 to 14, Comparative Examples 5 to 7 (A) Liquid crystalline polyester A-2, and (B) thermoplastic resin shown in Table 2 were weighed in various amounts and dry blended. 300
It was melt-extruded by a 30 mmφ twin-screw extruder set at 0 ° C., and the melt blend after extrusion was stretched by pulling a cutter. The extension ratio at this time was 6. The gut was pelletized and heat-treated under the conditions shown in Table 5. After heat treatment,
At the molding temperature and the mold temperature of 120 ° C. shown in Table 5, Examples 1 to 1 are performed.
A test piece similar to that of No. 11 was molded and the tensile strength and bending strength were measured. Table 5 shows the results of these tests.

[0050]

[Table 5] From the results in Table 5 above, it can be seen that heat treatment improves both tensile strength and bending strength.

[0051]

The molded article obtained from the resin composition according to the present invention has excellent mechanical properties and heat resistance, and can be widely used in applications such as electric and electronic equipment parts and automobile parts.

Claims (7)

[Claims] 1. A liquid crystal resin capable of forming an anisotropic melt phase (A) 1 to 50% by weight and a thermoplastic resin (B) 99.
A method for producing a resin composition, characterized in that -50% by weight is heat-treated after melt-kneading. 2. The resin composition according to claim 1, wherein the thermoplastic resin (B) is a crystalline thermoplastic resin satisfying the formula (1) or an amorphous thermoplastic resin satisfying the formula (2). Method of manufacturing things. TN + 10≥Tm (1) (where TN is the liquid crystal starting temperature of the liquid crystalline resin (A) before heat treatment, Tm is the melting point of the crystalline resin (B)) TN + 10≥Ts (2) (However, TN is the liquid crystal start temperature of the liquid crystalline resin (A) before heat treatment, and Ts is the lower limit of the moldable temperature of the amorphous resin (B). 3. The melt kneading is performed at a temperature not lower than the liquid crystal starting temperature of the liquid crystalline resin (A) and not lower than the melting point of the thermoplastic resin (B) or the moldable lower limit temperature.
A method for producing the resin composition described. 4. The method for producing a resin composition according to claim 2, wherein the heat treatment is performed at a temperature equal to or lower than the melting point of the thermoplastic resin (B) or the minimum moldable temperature. 5. The stretch ratio of the melt blended product after melt kneading is 4
The method for producing a resin composition according to claim 1, wherein the resin composition is heat-treated after being stretched as described above. 6. A liquid crystalline resin (A) comprising the following structural units (I) and (I
The method for producing a resin composition according to claim 1, which is a liquid crystalline polyester resin comprising I), (IV) or (I), (II), (III) and (IV). [Chemical 1] (However, in the formula, R1 is R1 represents one or more groups selected from 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. ) 7. The thermoplastic resin composition according to claim 2 is molded at a temperature not higher than the liquid crystal starting temperature of the liquid crystalline resin (A) and not lower than the melting point of the thermoplastic resin (B) or the moldable lower limit temperature. A method for producing a resin composition molded article, which is characterized.