JPH05186668A - Tubular molded material - Google Patents

Abstract

PURPOSE:To obtain a tubular molded article having a low coefficient thermal expansion, excellent toughness, thermal aging resistance, etc., comprising a resin composition prepared by adding an epoxy resin to a mixture of an anisotropic melt phase-forming liquid crystal polyester and a non-anisotropic melt phase-forming thermoplastic resin. CONSTITUTION:100 pts.wt. resin mixture comprising (A) 1-99wt.% anisotropic melt phase-forming liquid crystal polyester and (B) 99-1wt.% thermoplastic resin (preferably polybutylene terephthalate) not forming anisotropic melt phase is blended with (C) 0.01-20 pts.wt. epoxy compound (preferably diglycidyl ester compound such as phthalic acid diglycidyl ester) to give a resin composition, which is molded into a tubular shape. The component A, for example, is obtained by subjecting a diacylated compound of p-acetoxybenzoic acid and an aromatic dihydroxy compound such as 4,4'-diacetoxybiphenyl and an aromatic dicarboxylic acid such as terephthalic acid to deacetylating polycondensation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to tubular molded articles such as tubes, hoses and pipes having excellent mechanical properties and sliding properties at high temperatures. More specifically, the present invention relates to a tubular molded body having a small linear expansion coefficient and excellent toughness, which is suitable for engineering.

[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, optically anisotropic liquid crystal polymers have excellent mechanical properties. (JP-A-51-8395 and JP-A-49-72393).

The tubular molded product obtained from this liquid crystal polymer has not only its excellent mechanical properties but also a property of low linear expansion coefficient, but has a drawback that it does not have sufficient toughness and is easily fibrillated. I found out that

[0004]

To solve the problems of toughness and fibrillation, a thermoplastic resin such as polyethylene terephthalate was blended with a liquid crystal polyester to prepare a tubular molded body, and the problem of fibrillation was solved. It was found that the problem of toughness could not be solved yet.

Therefore, the present invention solves the above-mentioned problems, and has a small toughness in mechanical properties and linear expansion coefficient at high temperature, and a tubular molded article such as a tube, a hose or a pipe, and more specifically, a heat aging resistance, An object is to obtain a tubular molded body having excellent durability and suitable for engineering. As a result of intensive studies to solve the above problems, the present inventors have found that the mechanical properties are significantly improved by adding an epoxy compound, and arrived at the present invention.

[0006]

That is, the present invention provides (A)
Liquid crystalline polyester resins 1-99 that form an anisotropic melt phase
Wt% and (B) thermoplastic resin that does not form an anisotropic molten phase 9
With respect to 100 parts by weight of a resin mixture consisting of 9 to 1% by weight,
(C) The present invention provides a tubular molded body obtained by molding a resin composition containing 0.01 to 20 parts by weight of an epoxy compound into a tubular shape.

The present invention will be described in detail below. The liquid crystal polyester (A) used in the present invention is a polyester that forms an anisotropic melt phase, and includes p-hydroxybenzoic acid / polyethylene terephthalate liquid crystal polyester, p
-Hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid type liquid crystal polyester, p-hydroxybenzoic acid / 4,
Examples thereof include 4'-dihydroxybiphenyl / terephthalic acid / isophthalic acid type liquid crystal polyester. Among them, the following structural units (I), (II), (IV) or (I), (II), (II
A liquid crystal polyester composed of I) and (IV) is preferable.

[0008] (Where R ₁ is

[0009] R ₁ represents one or more groups selected from

[0010]

Shows one or more groups selected from Also,
In the formula, X represents a hydrogen atom or a chlorine atom, and the structural unit [(I
[I) + (III)] and the 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
A structural unit formed from an aromatic dihydroxy compound selected from (4-hydroxyphenyl) propane and 4,4′-dihydroxydiphenyl ether is represented by a structural unit (II
I) is a structural unit produced from ethylene glycol, and structural unit (IV) is terephthalic acid, isophthalic acid, 4,4′-diphenylcarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bis (phenoxy) ethane. Each of the structural units formed from an aromatic dicarboxylic acid selected from -4,4'-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid and diphenyl ether dicarboxylic acid is shown. Among these, especially structural units (II
I) is included, R ₁ is

[0012] Is 70 mol% or more of the structural unit (II), and R ₂ is

[0013]

It is particularly preferable that the above-mentioned occupies 70% by mole or more of the structural unit (IV). The above structural unit (I),
The copolymerization amounts of (II), (III) and (IV) are arbitrary. However, the following copolymerization amount is preferable from the viewpoint of fluidity. That is, when the structural unit (III) is included, the structural unit [(I) + (II)] is used in view of heat resistance and mechanical properties.
Is preferably 60 to 95 mol% of [(I) + (II) + (III)], and
7 to 92 mol% is more preferable. The structural unit (III) is preferably 40 to 5 mol% of [(I) + (II) + (III)],
~ 15 mol% is more preferred. In addition, the structural unit (I) / (I
The molar ratio of I) is preferably 75/25 to 95/5, and more preferably 78/22 to 95 from the viewpoint of the balance between fluidity and mechanical properties.
It is 93/7. Further, the structural unit (IV) is a structural unit [(I
I) + (III)] is substantially equimolar.

On the other hand, when the structural unit (III) is not contained, the structural unit (I) is [(I) + (I
I)] is preferably 40 to 90 mol%, particularly preferably 60 to 88 mol%, and the structural unit (IV) is substantially equimolar to the structural unit (II). In addition, when polycondensing the above preferred liquid crystalline polyester, the above structural unit
In addition to the components constituting (I) to (IV), aromatic dicarboxylic acids such as 3,3'-diphenyldicarboxylic acid, 2,2'-diphenyldicarboxylic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, etc. Aliphatic dicarboxylic acids, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, methylhydroquinone,
Aromatic diols such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxybenzophenone, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1 , 4-Cyclohexanediol, 1,4-
Aliphatic and alicyclic diols such as cyclohexanedimethanol and aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, and p
-Aminophenol, p-aminobenzoic acid and the like may be copolymerized in an amount that does not impair the object of the present invention.

The method for producing the liquid crystal polyester (A) in the present invention is not particularly limited, and it can be produced in accordance with a known polyester polycondensation method. For example, among the liquid crystal polyesters that can be preferably used, the above structural unit (III)
If it does not contain the following (1) to (4), the structural unit (III)
When it contains, the following production method (5) is preferable. (1) A method for producing a diacylated aromatic dihydroxy compound such as p-acetoxybenzoic acid and 4,4′-diacetoxybiphenyl and an aromatic dicarboxylic acid such as terephthalic acid by a deacetic acid polycondensation 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 used for production. (3) A method for producing from 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 of aromatic dicarboxylic acids such as bis (β-hydroxyethyl) terephthalate
In the presence of (hydroxyethyl) ester (1) or
The method of manufacturing by the method of (2).

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 The liquid crystal polyester (A) used in the present invention is capable of measuring the logarithmic viscosity in pentafluorophenol, in which case 0.1 g /
The value measured at a concentration of dl at 60 ° C. is preferably 0.5 or more, and particularly when the above structural unit (III) is contained,
2.5 dl / g is preferred.

The melt viscosity of the liquid crystal polyester (A) used in the present invention is preferably from 100 to 20,000 poise, more preferably from 2,000 to 2,000 poise. When the melt viscosity contains the structural unit (III), the melting point (Tm) +
Under the condition of 10 ° C, when the above structural unit (III) is not included, the liquid crystal starting temperature is + 40 ° C, and for other substances, when the melting point can be observed, it cannot be observed at the melting point (Tm) + 10 ° C. In the case, the values are measured by a Koka type flow tester at a liquid crystal starting temperature + 40 ° C. and a shear rate of 1,000 / sec.

Here, the melting point (Tm) is the endothermic peak temperature (Tm) observed in the differential calorimetric measurement when the polymerized polymer is measured at a temperature rising condition from room temperature to 20 ° C./min.
After observing 1), after keeping at Tm1 + 20 ℃ for 5 minutes,
After cooling down to room temperature at 20 ℃ / min.
It refers to the endothermic peak temperature (Tm2) observed when measured under temperature rising conditions of ° C / min. The liquid crystal starting temperature is a temperature at which the sample is placed on a sample stage of a deflection microscope, heated and heated to emit opalescence under shear stress.

The thermoplastic resin (B) used in the present invention is polyester, polycarbonate, polyarylene oxide, polyarylene sulfide, polyamide, polyoxymethylene, polysulfone, polyether sulfone, polyketone, polyolefin which does not form an anisotropic melt phase. One or more selected from the above, and preferred are polyester, polycarbonate, polyarylene oxide, and polyarylene sulfide. Among them, polyester is particularly preferable. The following are mentioned as a preferable specific example.

The thermoplastic polyester is a polyester which is thermoplastic and has an aromatic ring as a chain unit of the polymer, and includes 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 here include terephthalic acid, isophthalic acid, phthalic acid, and 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. Be done. If it is 30 mol% or less, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecanedioic acid and dimer acid, alicyclic rings such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid It may be replaced by the formula dicarboxylic acid. As the diol component, aliphatic and alicyclic diols having 2 to 10 carbon atoms, that is, ethylene glycol, propylene glycol, butylene glycol, 1,
5-pentane glycol, decamethylene glycol, 3
-Methyl-1,3-propene diol, neopentyl glycol, cyclohexane dimethanol, cyclohexane diol and the like, but not limited thereto. 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 / decane dicarboxylate, poly-1,4- Copolymerized polyesters such as cyclohexanedimethylene terephthalate / isophthalate can be mentioned. Among these, particularly preferred polyesters include polybutylene terephthalate, polyethylene terephthalate, and poly-1,4-cyclohexanedimethylene terephthalate. Of these, polybutylene terephthalate is most preferable. The logarithmic viscosity of polybutylene terephthalate used in the composition of the present invention is
It is preferably 0.9 to 1.3, and more preferably 0.9.
92 to 1.25. Incidentally, the polybutylene terephthalate logarithmic viscosity was obtained by dividing the logarithm of the relative viscosity obtained by using a 0.5% orthochlorophenol solution at 25 ° C. by the concentration.

Polycarbonates include bis (4-hydroxyphenyl), bis (3,5-dialkyl-4-).
Hydroxyphenyl) or bis (3,5-dihalo-4)
Polycarbonates based on hydrocarbon derivatives having -hydroxyphenyl) substitution are preferred, and polycarbonates based on 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) are particularly preferred.

Examples of the polyarylene oxide include polyarylene oxide.
(2,6-dimethyl-1,4-phenylene) ether,
2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol /
2,3,6-triethylphenol copolymer and the like can be mentioned. Polyarylene oxide includes polystyrene,
A styrenic resin such as high impact polystyrene can be added.

Polyarylene sulfide is one in which an aromatic ring and sulfur are bound. Preferred polyarylene sulfides include polyparaphenylene sulfide, which may be partially branched. In order to remove impurities contained in this polyphenylene sulfide, it is preferable to use treatment such as acid treatment or heat treatment. These methods include, for example, immersing PPS in an acid such as acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, or propyl acid or an aqueous solution thereof, and optionally heating and stirring, heating in a pressure vessel. Examples thereof include a method of treating water, a method of combining these methods, and the like. When these treatments are performed, it is preferable to wash with warm water several times in order to remove the remaining acid, salt and the like.

The blend composition (weight) of the liquid crystal polyester (A) and the thermoplastic resin (B) is 1/99 to 99/1. Preferably 5/95 to 50/50, more preferably 10/90
~ 40/60. Epoxy compound used in the present invention (C)
Is a compound having one or more epoxy groups and is not necessarily limited, but includes glycidyl ethers synthesized from phenols and epichlorohydrin such as bisphenol A diglycidyl ether and orthophenylphenol glycidyl ether, and hexahydrophthalate. Acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester,
Glycidyl esters such as isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, dimer acid diglycidyl ester, and glycidyl methacrylate, p
-Glycidyl ester / ethers consisting of hydroxycarboxylic acid such as glycidyl ester / ether of hydroxybenzoic acid and epichlorohydrin, epoxidized imide compound such as N-glycidyl phthalimide, epoxy group-unsaturated such as epoxidized polybutadiene and glycidyl methacrylate Epoxy group-containing copolymers composed of monomers and other unsaturated monomers such as ethylene, or γ-glycidoxypropyltrimethoxysilane, such as epoxysilanes usually used as a silane coupling agent. .. These epoxy compounds may be used alone or in combination of two or more.

Of the above epoxy compounds, a particularly preferred compound is a diglycidyl ester compound. The amount of the (C) epoxy compound in the composition of the present invention is
The amount is 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight, and more preferably 100 parts by weight of the resin mixture comprising (A) liquid crystal polyester and (B) thermoplastic polyester.
0.1 to 5 parts by weight. If it is less than 0.01 parts by weight, the bonding strength at the interface between both polyesters is weak and the improvement of mechanical properties is remarkably small. Conversely, if it exceeds 20 parts by weight, the mechanical properties and fluidity of the thermoplastic resin composition are low. It greatly decreases, and both are not preferable.

In producing the resin composition before molding of the present invention, conventionally known polyester polymerization catalysts, heat-resistant agents, weathering agents, antistatic agents, dyes, colorants, crystal nucleating agents, flame retardants, etc. Additives of takule, clay, mica,
It is also possible to add calcium metasilicate, silica sand, glass beads, glass flakes, potassium whisker titanate, inorganic fillers such as gypsum fiber, and reinforcing agents such as glass fiber, asbestos fiber and carbon fiber.

Particularly, the flame retardant is preferably an organic polymer flame retardant. As the organic polymer flame retardant, those having a bromine atom in the molecule are preferable, and those having a bromine content of 20% by weight or more are particularly preferable. Specific examples include brominated polycarbonate
(For example, a polycarbonate oligomer produced from brominated bisphenol A as a raw material or a copolymer thereof with bisphenol A), a brominated epoxy compound (for example, a diepoxy compound or brominated phenol produced by the reaction of brominated bisphenol A and epichlorohydrin) Compounds obtained by reaction of compounds with epichlorohydrin), poly (brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A, condensate of cyanuric chloride and brominated phenol, brominated polystyrene (brominated polystyrene) , A polymer of dibromostyrene), a crosslinked brominated polystyrene, a crosslinked brominated poly α-methylstyrene, or another halogenated polymer or oligomer, or a mixture thereof. Lenbis (tetrabromophthalimide), brominated epoxy oligomer or polymer, brominated polystyrene, crosslinked brominated polystyrene, brominated polyphenylene ether and brominated polycarbonate are preferable, and brominated polystyrene can be particularly preferably used.

The amount of the organic polymer flame retardant added is preferably 0.2 to 30 parts by weight per 100 parts by weight of the resin composition,
It is more preferably 0.5 to 20 parts by weight. Various methods can be applied as a method of mixing the liquid crystal polyester, the thermoplastic resin, and the epoxy compound. Examples of the apparatus for melt mixing include a mixing roll, a Banbury mixer, a kneader, an extruder, and the like. Among them, an extruder is preferable. As the extruder, either a single screw or a screw having two or more screws can be used, but it is particularly preferable to use a twin screw extruder.

In the present invention, the resin composition obtained as described above is molded into a tubular shape. As a molding method, a usual method such as injection molding, extrusion molding or blow molding can be applied. Extrusion is preferred. Further, a shear-controlled oriented extrusion technique as disclosed in “Plastic Age” No. 5 (1991), p. 184 can be exemplified as a preferable method for obtaining the tubular molded article of the present invention.

[0033]

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 p-Hydroxybenzoic acid 870 parts by weight, 4,4'-dihydroxybiphenyl 168 parts by weight, acetic anhydride 914 parts by weight, terephthalic acid 150 parts by weight and polyethylene terephthalate 259 parts by weight having an intrinsic viscosity of about 0.6 dl / g. 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.

First, after reacting in a nitrogen gas atmosphere at 100 to 250 ° C. for 1.5 hours, the pressure was reduced to 0.5 mmHg at 290 ° C. for 2 hours, and the reaction was continued for 1.0 hour to complete polycondensation. As a result, almost theoretical amount of acetic acid was distilled off to obtain a liquid crystal polyester (A-1) having the following theoretical structural formula.

[0035]

K / l / m / n = 70/10/20/30 This polyester has a melting point of 267 ° C. and an inherent viscosity (0.1 g / dl).
(Measured at 60 ° C in pentafluorophenol at a concentration of
It was 1.62 dl / g, and the melt viscosity at 270 ° C and a shear rate of 1000 / sec was 1050 poise. Reference Example 2 932 parts by weight of p-hydroxybenzoic acid 210 parts by weight of 4,4′-dihydroxybiphenyl 210 parts by weight of 2,6-diacetoxynaphthalene 274 parts by weight, 374 parts by weight of terephthalic acid and 1010 parts by weight of acetic anhydride were stirred and distilled. The reaction vessel was equipped with a discharge tube, and deacetic acid polycondensation was performed under the following conditions.

First, 5 at 100 to 250 ° C. in a nitrogen gas atmosphere.
After reacting at 250-330 ℃ for 1.5 hours, 310 ℃, 1.
The pressure was reduced to 0.5 mmHg in 5 hours, and the reaction was continued for 1.0 hour.
When the polycondensation was completed, almost the theoretical amount of acetic acid was distilled off, and a liquid crystal polyester (A-
2) was obtained.

[0038]

K / l / m / n = 75 / 12.5 / 12.5 / 25 This polyester has a melting point of 282 ° C. and an inherent viscosity (0.1 g / dl)
(Measured at 60 ° C in pentafluorophenol at a concentration of
The melt viscosity was 4.88 dl / g, and the melt viscosity at 300 ° C and a shear rate of 1000 / sec was 4100 poise. Examples 1 to 10 and Comparative Examples 1 to 4 (A) Liquid crystalline polyester A-1 or A-2; (B) Polybutylene terephthalate (logarithmic viscosity (measured at a concentration of 0.5 g / dl in orthochlorophenol at 25 ° C.) ), PBT
1: 0.81, PBT: 1.03) and (C) epoxy compound
A predetermined amount of each of (a) to (c) was weighed and dry-blended. It was melt-extruded by a 30 mmφ twin-screw extruder set at 270 to 300 ° C., cooled with water and pelletized.

[0040]

[0041]

[0042]

Next, the pellets obtained are dried and then 40
Used in mmφ single screw extruder, hopper 255-2
It was extruded from a 6 × 2 mm cylindrical die at a temperature setting of 90 ° C. to form a tube having an outer diameter of 6 mm and an inner diameter of 4 mm. The extrudability was good and a smooth surface was obtained. Furthermore, Example 1
~ 10, in order to investigate the toughness and linear expansion coefficient of each composition of Comparative Examples 1 to 4, the resulting pellets were subjected to Sumitomo Nestal injection molding machine Promat 40/25 (Sumitomo Heavy Industries Machinery Co., Ltd.), Cylinder temperature 300 ° C, mold temperature 90 ° C, 1/8 "
Thick ASTM No. 1 dumbbells and 1/8 "thickness x 1/2" width x 5 ⁷ length test pieces were made. The tensile elongation was measured using a Shimadzu Autograph 5t under the conditions of a strain rate of 10 mm / min and a span distance of 30 mm. The linear expansion coefficient was measured at 10 ° C./min using SSC-5000 manufactured by Seiko Denshi Kogyo Co., Ltd. The results are shown in Table 1.

[0044]

From the results shown in Table 1 above, it can be seen that the addition of the epoxy compound improves both the tensile elongation and the linear expansion coefficient as compared with the case of the composition comprising only (A) and (B). Examples 11 to 19, Comparative Examples 5 to 7 (A) Liquid crystalline polyester A-1 or A-2; (B) Polyethylene terephthalate (logarithmic viscosity, 0.93) and
(C) Epoxy compounds (see Examples 1 to 9) were weighed in predetermined amounts and dry-blended. It was melt-extruded by a 30 mmφ twin-screw extruder set at 270 to 300 ° C., cooled with water and pelletized. The obtained pellets were used in Examples 1 to 10 and Comparative Examples 1 to 4.
Tube molding was performed in the same manner as above, and the tensile elongation and the coefficient of linear expansion were measured using the molding test piece in the same manner as above. The results are shown in Table 2.

[0046]

From the results in Table 2 above, it can be seen that the addition of the epoxy compound improves both the tensile elongation and the linear expansion coefficient as compared with the case of the composition comprising only (A) and (B). Examples 20 to 22 and Comparative Examples 8 to 10 (A) Liquid crystalline polyester A-1 50 parts, (B) shown in Table 2
A predetermined amount of 50 parts of the thermoplastic resin and (C) epoxy compound (glycidyl ester of phthalic acid) were weighed and dry blended. It was melt extruded by a 30 mmφ twin-screw extruder set at 270 to 300 ° C., water-cooled and pelletized. The obtained pellets were molded into tubes in the same manner as in Examples 1 to 10 and Comparative Examples 1 to 4, and the tensile elongation and the coefficient of linear expansion were measured using the molding test pieces as described above.

[0048] From the results in Table 3 above, it was found that when an epoxy compound was used as a compatibilizer, the melt viscosity was lowered and the tensile elongation and the linear expansion coefficient were improved as compared with the case of the composition comprising (A) and (B). ..

[0049]

INDUSTRIAL APPLICABILITY The tubular molded article of the present invention is excellent in heat resistance, mechanical properties and moldability, and can be used in various applications such as a plastic member replacing metal.

Continuation of front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication B29L 23:00 4F (72) Inventor Fumio Akiyama 1 Toray Co., Ltd. 9-9 Oemachi, Minato-ku, Aichi Prefecture Nagoya business site

Claims (2)

[Claims] 1. A resin blend 100 comprising (A) 1 to 99% by weight of a liquid crystalline polyester resin which forms an anisotropic molten phase and (B) 99 to 1% by weight of a thermoplastic resin which does not form an anisotropic molten phase. A tubular molded body obtained by molding a resin composition in which 0.01 to 20 parts by weight of the epoxy compound (C) is added to parts by weight in a tubular shape. 2. A liquid crystal polyester resin which forms an anisotropic molten phase (A) has the following structural units (I), (II), (IV) or
The tubular molded article according to claim 1, which is a liquid crystalline polyester having a molecular structure composed of (I), (II), (III) and (IV). (However, in the formula, R ₁ is R ₂ 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 structural unit (IV) are substantially equimolar. )