WO2020070904A1

WO2020070904A1 - Liquid crystal polyester resin

Info

Publication number: WO2020070904A1
Application number: PCT/JP2018/048153
Authority: WO
Inventors: 大輔齋尾; 山下　哲也; 久成藤原
Original assignee: 上野製薬株式会社
Priority date: 2018-10-02
Filing date: 2018-12-27
Publication date: 2020-04-09

Abstract

The purpose of the present invention is to provide a liquid crystal polyester resin which exhibits excellent mechanical properties and suppresses blistering at the time of reflow. The present invention pertains to a liquid crystal polyester resin configured from repeating units represented by formulas (I)-(VII) [In the formula, p, q, r, s, t, u and v represent the compositional ratio (mol%) of each repeating unit in the liquid crystal polyester resin, and satisfy the following expressions: 15≤p≤30, 70≤q≤85, and 0.01≤r+s+t+u+v<2. Herein, the r, s, t, u and v are each at least 0 and less than 2, and an arbitrary two or more thereof are not 0].

Description

Liquid crystal polyester resin

This patent application claims the priority under the Paris Convention on Japanese Patent Application No. 2018-187393 (filing date: October 2, 2018), which is hereby incorporated by reference in its entirety. Shall be incorporated into the book.
The present invention relates to a liquid crystal polyester resin in which blister generation during reflow is suppressed.

Thermotropic liquid crystal polyester resin (hereinafter also referred to as liquid crystal polyester resin or LCP) is excellent in mechanical properties such as heat resistance and rigidity, chemical resistance, dimensional accuracy, etc., so that it is not only used for molded articles but also for fibers and films. Its use is expanding for various uses.

In particular, in the information and communication fields such as personal computers and mobile phones, components are rapidly becoming more highly integrated, smaller, thinner, and thinner, and cases where extremely thin thick portions are formed. There are many. Therefore, the amount of LCP used has been greatly increased by taking advantage of its excellent moldability, that is, good flowability and no burrs, which are not characteristic of other resins. As a liquid crystal polyester resin for forming a molded article useful as an electric / electronic part, a wholly aromatic polyester which requires a specific structural unit has been proposed (Patent Documents 1 and 2).

However, in recent years, lead-free soldering has led to higher reflow temperatures in applications for electronic components such as connectors, and even in molded products made of liquid crystal polyester resin, blisters called blisters caused by reflow treatment at high temperatures have swelled. Is a problem.

ブリ It is considered that such blisters are caused by air present in the mold or hopper, decomposed gas contained in the resin, air or moisture.

In addition, when the reflow temperature is increased, there is a problem that a molded product of the liquid crystal polyester resin is likely to be warped, and a filler such as talc may be added to the liquid crystal polyester resin in order to suppress the occurrence of the warpage. Are known.

However, since the filler such as talc contains a trace amount of water, in the liquid crystal polyester resin composition containing the filler such as talc, the occurrence of warpage of the molded product is suppressed, but the generation of blisters is suppressed. Has a problem that it tends to increase more.

多数 Numerous methods have been proposed for solving the problem of the occurrence of blisters in the molded product of the liquid crystal polyester resin. Specifically, a method of blending a silicone rubber, a phosphorus compound, a boron compound, or the like as an additive (Patent Documents 3 to 10), a method of adjusting a screw compression ratio during injection molding (Patent Document 11), or a liquid crystal polyester resin There is known a method of adjusting the screw engagement ratio when melt-kneading a material and an inorganic filler (Patent Document 12).

JP 2017-179127 A Japanese Patent No. 6411706 Japanese Patent Application Laid-Open No. 02-075653 JP 06-032880 A JP-A-10-036641 JP-A-10-158482 JP-A-11-140283 JP-A-11-197761 JP-A-2003-096279 JP 2004-196886 A JP-A-11-048278 JP-A-2003-212443

However, regarding the method of blending various additives to suppress the generation of blisters, the effect of suppressing the generation of blisters has room for improvement, and the mechanical properties of the liquid crystal polyester resin composition are large depending on the additives. There was a problem of lowering.

方法 In addition, the method of adjusting the screw setting at the time of injection molding or at the time of melt-kneading the liquid crystal polyester resin and the inorganic filler has a problem that a large work load is required as compared with the method of compounding the additive.

から Under these circumstances, there is a strong demand for the development of a liquid crystal polyester resin having excellent blister resistance without the need for operations such as compounding additives and adjusting screw settings during molding and the like.

目的 An object of the present invention is to provide a liquid crystal polyester resin which is excellent in mechanical properties and in which blister generation during reflow is suppressed.

In view of the above problems, the present inventors have conducted intensive studies and, as a result, by condensation polymerization of a monomer that gives a specific repeating unit, while maintaining excellent mechanical properties, generation of blisters during reflow is suppressed. It was found that a liquid crystal polyester resin was obtained, and the present invention was completed.

That is, the present invention relates to a liquid crystal polyester resin composed of repeating units represented by the following formulas (I) to (VII).

[Where,
p, q, r, s, t, u and v are the composition ratio (mol%) of each repeating unit in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ r + s + t + u + v <2, where r, s, t, u, and v are each 0 or more and less than 2, provided that any two or more of these are not 0]

(4) The liquid crystal polyester resin of the present invention is excellent in mechanical properties such as tensile strength / tensile elastic modulus and bending strength / flexural elasticity, and remarkably suppresses blistering during reflow. Therefore, the liquid crystal polyester resin of the present invention can be suitably used as a material for electrical and electronic parts such as thinned and highly integrated connectors, camera modules, antennas, and substrates.

において In the present specification and claims, the “liquid crystal polyester resin” is a polyester resin that forms an anisotropic molten phase, and is referred to in the art as a thermotropic liquid crystal polyester resin.

性質 The property of the anisotropic molten phase of the liquid crystal polyester resin can be confirmed by a normal polarization inspection method using an orthogonal polarizer. More specifically, the anisotropic molten phase can be confirmed by using a Leitz polarizing microscope and observing a sample placed on a Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere. The liquid crystal polyester resin of the present invention exhibits optical anisotropy, that is, it transmits light when inspected between orthogonal polarizers. If the sample is optically anisotropic, polarized light will be transmitted, even in the stationary state.

The liquid crystal polyester resin of the present invention is composed of the repeating units represented by the formulas (I) to (VII).

[Where,
p, q, r, s, t, u and v are the composition ratio (mol%) of each repeating unit in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ r + s + t + u + v <2, where r, s, t, u, and v are each 0 or more and less than 2, provided that any two or more of these are not 0. ]

In the liquid crystal polyester resin of the present invention, the composition ratio p of the repeating unit represented by the formula (I) to all the repeating units is 15 to 30 mol%, preferably 16 to 25 mol%, more preferably 17 to 24 mol%, More preferably, it is 18 to 24 mol%.

In the liquid crystal polyester resin of the present invention, the composition ratio q of the repeating unit represented by the formula (II) to all the repeating units is 70 to 85 mol%, preferably 75 to 84 mol%, more preferably 76 to 83 mol%, More preferably, it is 76 to 82 mol%.

と When the composition ratio p according to the formula (I) is more than 30 mol% or the composition ratio q according to the formula (II) is less than 70 mol%, the crystal melting temperature of the obtained liquid crystal polyester resin decreases. If the composition ratio p according to the formula (I) is less than 15 mol% or the composition ratio q according to the formula (II) is more than 85 mol%, polymerization becomes difficult.

単量体 Examples of the monomer giving the repeating unit represented by the formula (I) include 4-hydroxybenzoic acid and its ester-forming derivatives such as acylated products, ester derivatives and acid halides.

単量体 Examples of the monomer giving the repeating unit represented by the formula (II) include 6-hydroxy-2-naphthoic acid and its ester-forming derivatives such as acylated products, ester derivatives and acid halides.

In the liquid crystal polyester resin of the present invention, the composition ratio r of the repeating unit represented by the formula (III) to all the repeating units, the composition ratio s of the repeating unit represented by the formula (IV) to all the repeating units, and the formula (V) , The composition ratio t of the repeating unit represented by the formula (VI) with respect to all the repeating units, and the composition ratio u of the repeating unit represented by the formula (VI) and the composition of the repeating unit represented by the formula (VII) with respect to all the repeating units. The total amount (r + s + t + u + v) of the ratio v is 0.01 mol% or more and less than 2 mol%, preferably 0.03 to 1.9 mol%, more preferably 0.05 to 1.8 mol%, and still more preferably 0 to 1.8 mol%. 0.1 to 1.7 mol%, particularly preferably 0.2 to 1.6 mol%. Here, r, s, t, u, and v are each 0 or more and less than 2. However, any two or more of these are not zero. That is, the liquid crystal polyester resin of the present invention contains at least two or more arbitrary repeating units selected from the repeating units represented by the formulas (III) to (VII).

If the total amount (r + s + t + u + v) of the composition ratios r to v in each of the formulas (III) to (VII) is less than 0.01 mol%, the effect of suppressing the generation of blisters becomes insufficient, and is 2 mol% or more. As a result, mechanical properties such as tensile strength and tensile elastic modulus and bending strength and flexural modulus are reduced, and it is difficult to obtain the effect of suppressing blister generation.

Examples of the monomer giving the repeating unit represented by the formula (III) include isophthalic acid and its alkyl, alkoxy or halogen-substituted product, and ester derivatives and ester-forming derivatives thereof such as acid halides. .

Examples of the monomer giving the repeating unit represented by the formula (IV) include, for example, 2,6-naphthalenedicarboxylic acid and its alkyl, alkoxy or halogen-substituted product, and ester derivatives of these, and ester formation such as acid halides Sex derivatives.

Examples of the monomer that gives the repeating unit represented by the formula (V) include terephthalic acid and its alkyl, alkoxy or halogen-substituted product, and ester derivatives and ester-forming derivatives thereof such as acid halides. .

{Examples of the monomer giving the repeating unit represented by the formula (VI) include hydroquinone and alkyl-, alkoxy- or halogen-substituted products thereof, and ester-forming derivatives such as acylated products thereof.

Examples of the monomer giving the repeating unit represented by the formula (VII) include 4,4′-dihydroxybiphenyl and its alkyl, alkoxy or halogen-substituted products, and ester-forming derivatives such as acylated products thereof. Can be

とおり As described above, the liquid crystal polyester resin of the present invention contains at least two arbitrary units among the repeating units represented by the formulas (III) to (VII), and combinations thereof are not limited.

Preferred combinations of the repeating units represented by the formulas (III) to (VII) included in the liquid crystal polyester resin of the present invention are as follows.
(1) Combination of repeating units represented by Formula (III) and Formula (IV) (2) Combination of repeating units represented by Formula (III) and Formula (V) (3) Formula (IV) and Formula ( (4) Combination of repeating units represented by Formula (III), Formula (IV) and Formula (V) (5) Combination of repeating units represented by Formula (IV) and Formula (VI) (6) Combination of repeating units represented by formulas (IV) and (VII) (7) Combination of repeating units represented by formulas (V) and (VI) (8) Formula ( (IV) Combination of repeating units represented by formula (VII) (9) Combination of repeating units represented by formula (III) and formula (VI)

Among these, the combination of (1) to (4) is particularly preferred.
In the combinations of (1) to (3), the ratio (r / s) of the composition ratio r according to the formula (III) and the composition ratio s according to the formula (IV), the composition ratio r according to the formula (III) and the formula ( The ratio (r / t) of the composition ratio t according to V) and the ratio (s / t) of the composition ratio t according to the formula (IV) and the composition ratio t according to the formula (V) are 0.1 to 10 respectively. Is preferably, more preferably 0.2 to 5, and further preferably 0.4 to 2.5.

In the combination of (4), the ratio (r / s / t) of the composition ratio r according to the formula (III), the composition ratio s according to the formula (IV), and the composition ratio t according to the formula (V) is 0. It is preferably from 1 to 10 / 0.1 to 10 / 0.1 to 10, more preferably from 0.2 to 5 / 0.2 to 5 / 0.2 to 5, and from 0.4 to 5 / 0.2 to 5 / 0.2 to 5. More preferably, it is 2.5 / 0.4 to 2.5 / 0.4 to 2.5.

In one embodiment, the combination of (2) or the combination of (3) is preferably adopted.
In this embodiment, in the combination of (2), the ratio (r / t) of the composition ratio r according to the formula (III) and the composition ratio t according to the formula (V) is 1 or more (that is, 1 or 1 Is more preferable, the value is more preferably 1.2 or more, and further preferably 1.5 or more. The above ratio (r / t) is usually 5 or less, preferably 4 or less, more preferably 3 or less.

In this embodiment, in the combination of (3), the ratio (s / t) between the composition ratio s according to the formula (IV) and the composition ratio t according to the formula (V) is 1 or more (that is, 1 or 1). 1 or more), more preferably 1.2 or more, and even more preferably 1.5 or more. The above ratio (s / t) is usually 5 or less, preferably 4 or less, more preferably 3 or less.

In another embodiment, in the combination of (2), the ratio (r / t) of the composition ratio r according to the formula (III) to the composition ratio t according to the formula (V) is preferably less than 1; It is more preferably from 1 to 0.9, further preferably from 0.2 to 0.8, and particularly preferably from 0.3 to 0.7.

In this embodiment, in the combination of (3), the ratio (s / t) of the composition ratio s according to the formula (IV) and the composition ratio t according to the formula (V) is preferably less than 1; It is more preferably from 0.1 to 0.9, further preferably from 0.2 to 0.8, and particularly preferably from 0.3 to 0.7.

In the liquid crystal polyester resin of the present invention, the total [p + q + r + s + t + u + v] of the composition ratios of the respective repeating units is preferably 100 mol%, but other repeating units may be further contained as long as the object of the present invention is not impaired. . When the liquid crystal polyester resin of the present invention further contains another repeating unit, the composition ratio α of the other repeating unit is 10 mol% or less based on 100 mol% of the total of the repeating units constituting the liquid crystal polyester resin. Is more preferably 5 mol% or less, further preferably 3 mol% or less, and particularly preferably 1 mol% or less.

Examples of the monomer giving another repeating unit include aromatic hydroxycarboxylic acid, aromatic diol, aromatic dicarboxylic acid, aromatic hydroxydicarboxylic acid, aromatic hydroxyamine, aromatic diamine, aromatic aminocarboxylic acid, and alicyclic ring. Examples thereof include aromatic dicarboxylic acids, aliphatic diols, alicyclic diols, aromatic mercaptocarboxylic acids, aromatic dithiols, and aromatic mercaptophenols.

The method for producing the liquid crystal polyester resin of the present invention is not particularly limited, and a known polyester resin polycondensation method for forming an ester bond between the above monomer components, for example, a melt acidilysis method, a slurry polymerization method, or the like may be used. it can.

Molten acid lysis is a method in which a monomer is first heated to form a molten solution of a reactant, and then the reaction is continued to obtain a molten polymer. In addition, vacuum may be applied to facilitate removal of volatiles (for example, acetic acid, water, and the like) by-produced in the final stage of the condensation. This method is particularly preferably used in the present invention.

Slurry polymerization is a method in which a reaction is performed in the presence of a heat exchange fluid, and a solid product is obtained in a state of being suspended in a heat exchange medium.

In both cases of the melt acidilysis method and the slurry polymerization method, the polymerizable monomer component used in producing the liquid crystal polyester resin should be subjected to the reaction as a modified form in which a hydroxyl group is esterified, that is, a lower acyl ester. Can also. The lower acyl group preferably has 2 to 5 carbon atoms, more preferably 2 or 3 carbon atoms. Particularly preferred is a method in which an acetic acid ester of the monomer component is used for the reaction.

The lower acyl ester of the monomer may be separately acylated and used in advance, or may be produced in the reaction system by adding an acylating agent such as acetic anhydride to the monomer during the production of the liquid crystal polyester resin. it can.

触媒 A catalyst may be used as required in either the melt acidilysis method or the slurry polymerization method.

Specific examples of the catalyst include organic tin compounds such as dialkyltin oxide (eg, dibutyltin oxide) and diaryltin oxide; organic titanium compounds such as titanium dioxide, antimony trioxide, alkoxytitanium silicate, and titanium alkoxide; alkali and alkali carboxylic acids. Earth metal salts (eg, potassium acetate); alkali and alkaline earth metal salts of inorganic acids (eg, potassium sulfate); gaseous acid catalysts such as Lewis acids (eg, BF ₃ ), hydrogen halides (eg, HCl), and the like. Can be

使用 The use ratio of the catalyst is usually 10 to 1000 ppm, preferably 20 to 200 ppm, based on the total amount of the monomers.

The thus obtained liquid crystal polyester resin of the present invention has a crystal melting temperature measured by a differential scanning calorimeter (DSC) described later, preferably from 290 to 340 ° C, more preferably from 295 to 335 ° C, and still more preferably. The temperature is 300 to 330 ° C, particularly preferably 305 to 325 ° C.

Further, the liquid crystal polyester resin of the present invention preferably has a melt viscosity measured at 350 ° C. of 1 to 1000 Pa · s, more preferably 5 to 300 Pa · s, still more preferably 8 to 200 Pa · s, and particularly preferably. Is 12 to 150 Pa · s.

In addition, the liquid crystal polyester resin of the present invention has a tensile strength of preferably 180 MPa or more measured using a dumbbell-shaped test piece having a length of 63.5 mm × a width of 3.5 mm × a thickness of 2.0 mm in accordance with ASTM D638. And the tensile modulus is preferably 7.7 GPa or more.

(4) The tensile strength is more preferably 190 MPa or more, still more preferably 200 MPa or more, and usually 280 MPa or less.

The tensile modulus is more preferably 8.0 GPa or more, still more preferably 8.2 GPa or more, and usually 15.0 GPa or less.

Further, the liquid crystal polyester resin of the present invention has a bending strength of 165 MPa or more measured using a rectangular test piece having a length of 65 mm × a width of 12.7 mm × a thickness of 2.0 mm in accordance with ASTM D790. The elastic modulus is 9.0 GPa or more.

The bending strength is more preferably 170 MPa or more, still more preferably 175 MPa or more, and usually 250 MPa or less.

The flexural modulus is more preferably 9.5 GPa or more, further preferably 10.0 GPa or more, and usually 15.0 GPa or less.

The present invention further provides a liquid crystal polyester resin composition obtained by mixing one or more of a fibrous, plate-like, or powdery filler with the liquid crystal polyester resin of the present invention. The filler may be appropriately selected from substances conventionally known to be used in resin compositions according to the intended use and application of the liquid crystal polyester resin composition.

Examples of the fibrous filler include glass fiber, silica-alumina fiber, alumina fiber, carbon fiber, and aramid fiber. Among these, glass fibers are preferred because they have an excellent balance between physical properties and cost.

Plate-like or powdery fillers include, for example, talc, mica, graphite, wollastonite, calcium carbonate, dolomite, clay, glass flakes, glass beads, barium sulfate, titanium oxide and the like. Of these, talc is preferred because of its excellent balance between physical properties and cost.

において In the liquid crystal polyester resin composition of the present invention, the total amount of the filler is preferably from 0.1 to 200 parts by weight, particularly preferably from 10 to 100 parts by weight, based on 100 parts by weight of the liquid crystal polyester resin. When the compounding amount of the filler exceeds 200 parts by mass, the molding processability of the liquid crystal polyester resin composition is reduced, and the cylinder and the mold of the molding machine tend to be abraded.

The liquid crystal polyester resin or liquid crystal polyester resin composition of the present invention includes a mold release of a higher fatty acid, a higher fatty acid ester, a higher fatty acid amide, a higher fatty acid metal salt, a polysiloxane, a fluororesin, etc., as long as the effects of the present invention are not impaired. Colorants such as dyes and pigments; antioxidants; heat stabilizers; ultraviolet absorbers; antistatic agents; surfactants and other known additives, depending on the purpose and application. Or one or more of them may be combined.

(4) Those having an external lubricant effect, such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon surfactants, may be used by adhering them to pellets before molding.

The liquid crystal polyester resin composition of the present invention is obtained by adding all components such as fillers and additives to the polyester resin, and melting the crystal of the liquid crystal polyester resin using a Banbury mixer, a kneader, a single screw or twin screw extruder, or the like. It can be prepared by melting and kneading at a temperature close to the crystal melting temperature + 100 ° C.

The liquid crystal polyester resin and the liquid crystal polyester resin composition of the present invention thus obtained can be obtained by injection molding, compression molding, extrusion molding, blow molding, and other known molding methods, such as injection molded articles, films, sheets, and nonwoven fabrics. Can be processed.

The liquid crystal polyester resin and the liquid crystal polyester resin composition of the present invention are excellent in blister resistance, heat resistance, mechanical strength such as tensile strength / tensile elastic modulus, flexural strength / flexural modulus, and so on. It is suitably used as a material for electric and electronic parts such as antennas and substrates.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.
In the examples, the following abbreviations represent the following compounds.
POB: 4-hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid IPA: isophthalic acid NDA: 2,6-naphthalenedicarboxylic acid TPA: terephthalic acid HQ: hydroquinone BP: 4,4′-dihydroxybiphenyl

<Measurement of crystal melting temperature>
The measurement was performed using Exstar6000 manufactured by Seiko Instruments Inc. as a differential scanning calorimeter. The liquid crystal polyester resin sample was measured from room temperature under a heating condition of 20 ° C./min, and after observing the endothermic peak temperature (Tm1), the sample was held at a temperature 20 to 50 ° C. higher than Tm1 for 10 minutes. Next, after cooling the sample to room temperature under a temperature-lowering condition of 20 ° C./min, an endothermic peak was again observed when the temperature was measured under a temperature-raising condition of 20 ° C./min. Temperature.

<Measurement of melt viscosity>
The melt viscosity under a condition of a shear rate of 1000 sec ^-1 and 350 ° C. was measured with a melt viscosity measuring device (Capillograph 1D manufactured by Toyo Seiki Co., Ltd.) using a capillary of 0.7 mmφ × 10 mm.

<Measurement of tensile strength and tensile modulus>
Using an injection molding machine (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.) with a mold clamping pressure of 15 t, injection molding was performed at a cylinder melting temperature of +20 to 40 ° C. and a mold temperature of 70 ° C., and a dumbbell-shaped test piece ( 63.5 mm long x 3.5 mm wide x 2.0 mm thick). The tensile test was performed using INSTRON5567 (a universal testing machine manufactured by Instron Japan Company Limited) in accordance with ASTM D638 at a distance between the chucks of 25.4 mm and a tensile speed of 5 mm / min.

<Measurement of flexural strength and flexural modulus>
Using an injection molding machine (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.) with a mold clamping pressure of 15 t, injection molding was performed at a cylinder melting temperature of +20 to 40 ° C. and a mold temperature of 70 ° C. (Length 65 mm x width 12.7 mm x thickness 2.0 mm). In the bending test, a three-point bending test was performed using INSTRON5567 (a universal testing machine manufactured by Instron Japan Company Limited) in accordance with ASTM D790 at a distance between spans of 40.0 mm and a compression speed of 1.3 mm / min.

<Measurement of Izod impact strength>
Using an injection molding machine (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.) with a mold clamping pressure of 15 t, injection molding was performed at a cylinder melting temperature of +20 to 40 ° C. and a mold temperature of 70 ° C. (Length 65 mm x width 12.7 mm x thickness 2.0 mm). Izod impact strength was measured according to ASTM D256. The greater the value of the Izod impact strength, the better the flexibility.

<Measurement of deflection temperature under load (DTUL)>
Using an injection molding machine (Nissei Plastic Industry Co., Ltd. UH1000-110), a strip test having a length of 127 mm, a width of 12.7 mm and a thickness of 3.2 mm was performed at a cylinder setting temperature of 350 ° C. and a mold temperature of 70 ° C. It was molded into a piece, and using this, it was measured at a load of 1.82 MPa and a heating rate of 2 ° C./min in accordance with ASTM D648.

<Evaluation of blister generation>
Using an injection molding machine (NEX-15-1E manufactured by Nissei Plastics Co., Ltd.), injection molding was performed at a cylinder melting temperature of +20 to 40 ° C. and a mold temperature of 140 ° C., and a box-shaped test piece (30 mm long × 5 mm wide × Height 6 mm, thickness 0.2 mm). This box-shaped test piece was subjected to a heat treatment at 260 ° C. and 280 ° C. for 10 minutes in a gear oven, and after cooling, the number of blisters (blisters) generated on the surface was visually observed. Thirty test specimens were evaluated for each test, and the test specimens with swelling were evaluated as ５ when the number was 0 to 5, Δ when the number was 6 to 10, and × when the number was 11 or more.

[Example 1]
In a reaction vessel equipped with a stirrer equipped with a torque meter and a distilling tube, POB: 204.7 g (22.8 mol%), BON 6: 935.7 g (76.5 mol%), IPA 5.5 g (0.5 mol) %) And 2.2 g (0.2 mol%) of TPA, and 1.03 times the molar amount of acetic anhydride with respect to the amount of hydroxyl groups (mol) of all the monomers. Was done.

温 The temperature was raised from room temperature to 150 ° C. over 1 hour in a nitrogen gas atmosphere, and the temperature was maintained for 30 minutes. Next, the temperature was quickly raised to 210 ° C. while distilling off by-produced acetic acid, and kept at the same temperature for 30 minutes. Thereafter, the temperature was raised to 350 ° C. over 4 hours, and then reduced to 10 mmHg over 80 minutes. The polymerization reaction was terminated when a predetermined torque was obtained, the contents of the reaction vessel were taken out, and pellets of liquid crystal polyester resin were obtained with a pulverizer. The amount of acetic acid distilled at the time of polymerization was almost the same as the theoretical value. Using the obtained pellets, the crystal melting temperature, tensile strength, tensile modulus, tensile strain, bending strength, flexural modulus, Izod impact strength, DTUL and blister generation were measured and evaluated by the above-described methods. The results are shown in Tables 1 and 2.

[Examples 2 to 6, 8 to 10 and Comparative Examples 1 to 5, 7 to 9]
Pellets of a liquid crystal polyester resin were obtained in the same manner as in Example 1, except that POB, BON6, IPA, NDA, TPA, HQ, and BP were changed so as to have the ratios (mol%) shown in Table 1. Using the obtained pellets, the crystal melting temperature, tensile strength, tensile modulus, tensile strain, bending strength, flexural modulus, Izod impact strength, DTUL and blister generation were measured and evaluated by the above-described methods. The results are shown in Tables 1 and 2.

In Comparative Example 4, when the temperature was raised to 350 ° C. over 4 hours, the content was solidified and the stirring became impossible when the temperature was raised to 305 ° C., and the reaction was stopped to obtain a liquid crystal polyester resin. Could not.

[Example 7]
Using the resin of Example 1 as a liquid crystal polyester resin, 10 parts by mass of glass fiber (chopped glass having a fiber diameter of 10.5 μm and a fiber length of 3 mm) and talc (average particles) were used as fillers with respect to 100 parts by mass of the liquid crystal polyester resin. 20 parts by mass (diameter: 19 μm) were blended and melt-kneaded with a twin-screw extruder (TEX-30, manufactured by Nippon Steel Corporation) into pellets to obtain pellets of a liquid crystal resin composition. Using the obtained pellets, blister generation was evaluated by the above method. The results are shown in Tables 1 and 2.

[Comparative Example 6]
Pellets were obtained in the same manner as in Example 1 except that the resin of Comparative Example 1 was used as the liquid crystal polyester resin, and blister generation was evaluated. The results are shown in Tables 1 and 2.

示す As shown in the above table, the liquid crystal polyester resin and the liquid crystal polyester resin composition according to each of the examples of the present invention were all excellent in mechanical properties and excellent in blister resistance during reflow.

On the other hand, in the cases not according to the present invention (Comparative Examples), the evaluation results were insufficient in all of the blister resistance during reflow, and the mechanical properties or their balance were not sufficient. . In Comparative Example 5, a decrease was also found in the crystal melting temperature of the liquid crystal polyester resin.

Claims

Formulas (I) to (VII)

[Where,
p, q, r, s, t, u and v are the composition ratio (mol%) of each repeating unit in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ r + s + t + u + v <2, where r, s, t, u, and v are each 0 or more and less than 2, provided that any two or more of these are not 0]
A liquid crystal polyester resin composed of a repeating unit represented by
The liquid crystal polyester resin according to claim 1, wherein the crystal melting temperature measured by a differential scanning calorimeter is 290 to 340 ° C.
Using a dumbbell-shaped test piece having a length of 63.5 mm × a width of 3.5 mm × a thickness of 2.0 mm, the tensile strength is 180 MPa or more and the tensile modulus is 7.7 GPa or more, measured in accordance with ASTM D638. The liquid crystal polyester resin according to claim 1, wherein
The bending strength is 165 MPa or more and the flexural modulus is 9.0 GPa or more, measured according to ASTM No. D790 using a rectangular test piece having a length of 65 mm × a width of 12.7 mm × a thickness of 2.0 mm. The liquid crystal polyester resin according to any one of claims 1 to 3.
(5) A liquid crystal polyester resin composition comprising 0.1 to 200 parts by mass of a fibrous, plate-like, or powdery filler based on 100 parts by mass of the liquid crystal polyester resin according to any one of (1) to (4).
(4) A molded article comprising the liquid crystal polyester resin according to any one of (1) to (4) or the liquid crystal polyester resin composition according to (5).