JP6533880B1 - Liquid crystal polyester resin - Google Patents

Abstract

An object of the present invention is to provide a liquid crystalline polyester resin which is excellent in mechanical properties and in which the occurrence of blisters at the time of reflow is suppressed. In the present invention, formulas (I) to (V) [wherein p, q, r, s and t respectively represent the compositional ratio (mol%) of each repeating unit in the liquid crystal polyester resin, The conditions are satisfied: 15 ≦ p ≦ 30, 70 ≦ q ≦ 85, 0.01 ≦ r + s + t <2, where r, s and t are each 0 or more and 2 or less, where r, s and t are The present invention relates to a liquid crystalline polyester resin composed of a repeating unit represented by [not simultaneously 0].

Description

This patent application claims priority under the Paris Convention for Japanese Patent Application No. 2018-187392 (filing date: October 2, 2018), which is incorporated herein by reference in its entirety. Shall be incorporated into the book.
The present invention relates to a liquid crystal polyester resin in which the occurrence of blisters during reflow is suppressed.

  Thermotropic liquid crystalline polyester resin (hereinafter, also referred to as liquid crystalline polyester resin or LCP) is excellent in mechanical properties such as heat resistance and rigidity, chemical resistance, dimensional accuracy, etc. Its use is expanding to various applications such as

  In the information and communication fields such as personal computers and mobile phones, in particular, there is a rapid progress in increasing the degree of integration of components, downsizing, thinning and shortening, and a case in which a very thin thick portion is formed There are many. Therefore, the amount of LCP used is greatly increased by taking advantage of the excellent moldability, that is, good flowability, and the feature not found in other resins that burrs do not appear. As a liquid crystalline polyester resin for forming a molded article useful as an electrical and electronic component, a wholly aromatic polyester essentially comprising a specific structural unit has been proposed (Patent Documents 1 and 2).

  However, in recent years, the reflow temperature has been raised in electronic component applications such as connectors due to the use of lead-free solder, and the blister on the surface of the molded product is called blister caused by reflow processing at high temperature even for liquid crystal polyester resin molded products. The occurrence of is a problem.

  The occurrence of such blisters is considered to be caused by the air present in the mold or hopper, the decomposition gas contained in the resin, air or moisture.

  In addition, when the reflow temperature rises, there is a problem that the molded article of the liquid crystal polyester resin is easily warped, and in order to suppress the occurrence of the warp, a filler such as talc may be blended in the liquid crystal polyester resin Are known.

  However, since the filler such as talc contains a small amount of water, in the liquid crystal polyester resin composition containing the filler such as talc, the occurrence of the warpage of the molded article is suppressed, but the blister is generated. There is a problem that is more likely to increase.

  A number of methods have been proposed for solving such a problem of blistering of a liquid crystal polyester resin molded article. Specifically, a method of blending 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 at the time of injection molding (patent document 11), or a liquid crystal polyester resin There is known a method of adjusting a screw meshing ratio in the case of melt-kneading an inorganic filler and the like (Patent Document 12).

JP, 2017-179127, A Patent No. 6411706 JP 02-075653 A JP 06-032880 A Japanese Patent Application Laid-Open No. 10-036641 JP-A-10-158482 JP 11-140283 A Japanese Patent Application Laid-Open No. 11-199761 Japanese Patent Application Laid-Open No. 2003-096279 Unexamined-Japanese-Patent No. 2004-196886 JP-A-11-048278 Unexamined-Japanese-Patent No. 2003-211443

  However, with regard to the method of blending various additives in order to suppress the occurrence of blisters, the effect of suppressing the occurrence of blisters has room for improvement, and depending on the additives, the mechanical properties of the liquid crystal polyester resin composition are large. There was a problem of falling.

  Further, the method of adjusting the setting of the screw at the time of injection molding or at the time of melt-kneading of 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 blending the additive.

  Under these circumstances, there is a strong demand for the development of a liquid crystal polyester resin excellent in blister resistance without requiring operations such as the setting of a screw at the time of compounding of an additive or molding or the like.

  An object of the present invention is to provide a liquid crystal polyester resin which is excellent in mechanical properties and in which the occurrence of blisters at the time of reflow is suppressed.

  As a result of intensive studies conducted by the present inventors in view of the above problems, by condensation polymerization of a monomer giving a specific repeating unit, generation of blisters during reflow is suppressed while maintaining excellent mechanical properties. It has been found that a liquid crystalline polyester resin can be obtained, and the present invention has been completed.

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

［式中、
ｐ、ｑ、ｓおよびｔは、それぞれ、液晶ポリエステル樹脂中での各繰返し単位の組成比（モル％）であり、以下の条件を満たす：
１５≦ｐ≦３０、
７０≦ｑ≦８５、
０．０１≦ｓ＋ｔ＜２、ここで、ｓ、ｔは、それぞれ０以上２未満であり、但し、これらは同時に０でない。］[In the formula,
p, q, r, s and t are composition ratios (mol%) of the respective repeating units in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ r + s + t <2, where r, s and t are each 0 or more and 2 or less, provided that they are not 0 simultaneously. ]
In addition, a preferred embodiment of the present invention relates to a liquid crystal polyester resin composed of a repeating unit represented by the following formula.

[In the formula,
p, q, s, and t are composition ratios (mol%) of respective repeating units in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ s + t <2, where s and t are each greater than or equal to 0 and less than 2, provided that they are not simultaneously 0. ]

  The liquid crystal polyester resin of the present invention is excellent in mechanical properties such as tensile strength and tensile modulus, flexural strength and flexural modulus, and the occurrence of blisters at the time of reflow is remarkably suppressed. Therefore, the liquid crystal polyester resin of the present invention can be suitably used as a material of components for electrical and electronic parts such as thin-layered, highly integrated connectors, camera modules, antennas, substrates and the like.

  In the present specification and claims, the "liquid crystalline polyester resin" is a polyester resin that forms an anisotropic melt phase, and is referred to in the art as a thermotropic liquid crystalline polyester resin.

  The properties of the anisotropic melt phase of the liquid crystalline polyester resin can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. More specifically, confirmation of the anisotropic melt phase can be performed by observing the sample mounted on the Leitz hot stage under a nitrogen atmosphere at a magnification of 40 using a Leitz polarization microscope. The liquid crystalline polyester resin of the present invention exhibits optical anisotropy, that is, transmits light when inspected between crossed polarizers. If the sample is optically anisotropic, it will transmit polarized light, even in the quiescent state.

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

[In the formula,
p, q, r, s and t are composition ratios (mol%) of the respective repeating units in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ r + s + t <2, where r, s and t are each 0 or more and 2 or less, provided that r, s and t are not 0 simultaneously. ]

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

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

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

  As a monomer which gives the repeating unit represented by Formula (I), ester forming derivatives, such as 4-hydroxybenzoic acid and its acylation thing, an ester derivative, an acid halide etc., are mentioned, for example.

  Examples of the monomer giving the repeating unit represented by the formula (II) include 6-hydroxy-2-naphthoic acid and ester-forming derivatives such as an acyl derivative thereof, an ester derivative and an acid halide.

  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 repeating units, the composition ratio s of the repeating unit represented by the formula (IV) to all repeating units, and the formula (V) The total amount (r + s + t) of the composition ratio t to all the repeating units of the repeating units represented by is 0.01 mol% or more and less than 2 mol%, preferably 0.03 to 1.9 mol%, more preferably 0. It is preferably 0.5 to 1.8 mol%, more preferably 0.1 to 1.7 mol%, particularly preferably 0.2 to 1.6. Here, r, s and t are each 0 or more and 2 or less, provided that r, s and t are not 0 simultaneously.

  Suppression of blistering when the total amount (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 less than 0.01 mol% When the effect is insufficient and the content is 2 mol% or more, mechanical properties such as tensile strength and tensile modulus, bending strength and flexural modulus are lowered, and it is also difficult to obtain the effect of suppressing blistering.

  In the liquid crystal polyester resin of the present invention, at least one of the repeating unit represented by the formula (III), the repeating unit represented by the formula (IV) and the repeating unit represented by the formula (V) It exists as a structural unit of liquid crystal polyester resin. The repeating unit represented by the formula (III), the repeating unit represented by the formula (IV) and the repeating unit represented by the formula (V) are present only as constituent units of the liquid crystalline polyester resin. Or two or more may be present in combination.

  For example, when (1) liquid crystal polyester resin does not contain the repeating unit represented by Formula (IV) and Formula (V) (s and t are 0), the composition ratio r which concerns on Formula (III) is 0. In the case where 01 ≦ r <2, and the repeating unit represented by the formula (III) is not included (2) (r is 0), the composition ratio s related to the formula (IV) and the composition ratio related to the formula (V) The total amount (s + t) of t is 0.01 ≦ s + t <2.

  Also, for example, when (3) liquid crystal polyester resin does not contain the repeating units represented by the formula (III) and the formula (V) (r and t are 0), the composition ratio s according to the formula (IV) is In the case where 0.01 ≦ s <2, and the repeating unit represented by the formula (IV) is not included (4 is 0), the composition ratio r according to the formula (III) and the formula (V) The total amount (r + t) of the composition ratio t is 0.01 ≦ r + t <2.

  Also, for example, when (5) the liquid crystal polyester resin does not contain the repeating units represented by the formulas (III) and (IV) (r and s are 0), the composition ratio t according to the formula (V) is When 0.01 ≦ t <2, and the repeating unit represented by the formula (V) is not included (t is 0), the composition ratio r according to the formula (III) and the formula (IV) The total amount (r + s) of the composition ratio s is 0.01 ≦ r + s <2.

［式中、
ｐ、ｑ、ｓおよびｔは、それぞれ、液晶ポリエステル樹脂中での各繰返し単位の組成比（モル％）であり、以下の条件を満たす：
１５≦ｐ≦３０、
７０≦ｑ≦８５、
０．０１≦ｓ＋ｔ＜２、ここで、ｓ、ｔは、それぞれ０以上２未満であり、但し、これらは同時に０でない］
で表される繰返し単位から構成される液晶ポリエステル樹脂に関する。In the liquid crystal polyester resin of the present invention, two or more of the repeating unit represented by the formula (III), the repeating unit represented by the formula (IV) and the repeating unit represented by the formula (V) are combined Among the above-mentioned (2), (4) and (6), it is a case where the repeating unit represented by (2) formula (III) is not included (r is 0) when it exists, and formula (IV) It is preferable that a total amount (s + t) of the composition ratio s according to and the composition ratio t according to the formula (V) be 0.01 ≦ s + t <2.
That is, a preferred embodiment of the present invention has the following formula:

[In the formula,
p, q, s, and t are composition ratios (mol%) of respective repeating units in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ s + t <2, where s and t are each 0 or more and 2 or less, provided that these are simultaneously not 0]
The present invention relates to a liquid crystalline polyester resin composed of a repeating unit represented by

  In the liquid crystal polyester resin of the present invention, the repeating unit represented by the formula (III), the repeating unit represented by the formula (IV) and the repeating unit represented by the formula (V) contain only any one of them. Is preferred.

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

  Examples of the monomer giving the repeating unit represented by the formula (IV) include 2,6-naphthalenedicarboxylic acid and its alkyl, alkoxy or halogen substitution products, and ester derivatives thereof such as acid derivatives and ester derivatives thereof. And sex derivatives.

  As a monomer which gives the repeating unit represented by Formula (V), ester forming derivatives, such as hydroquinone and its alkyl, alkoxy or halogen substitution products, and these acyl compounds, are mentioned, for example.

  In the liquid crystal polyester resin of the present invention, the total [p + q + r + s + t] of the composition ratio of each repeating unit is preferably 100 mol%, but other repeating units may be further included within the scope of the present invention. . When the liquid crystalline polyester resin of the present invention further includes other repeating units, the composition ratio α of the other repeating units is 10 mol% or less with respect to 100 mol% in total of the repeating units constituting the liquid crystal polyester resin. Is more preferably 5 mol% or less, still more preferably 3 mol% or less, particularly preferably 1 mol% or less.

  As monomers giving other repeating units, aromatic hydroxycarboxylic acid, aromatic diol, aromatic dicarboxylic acid, aromatic hydroxydicarboxylic acid, aromatic hydroxyamine, aromatic diamine, aromatic aminocarboxylic acid, alicyclic And aliphatic dicarboxylic acids, aliphatic diols, alicyclic diols, aromatic mercaptocarboxylic acids, aromatic dithiols and aromatic mercaptophenols.

  There is no particular limitation on the method for producing the liquid crystalline polyester resin of the present invention, and a polycondensation method of a known polyester resin in which an ester bond is formed between the above monomer components, for example, a melt acidolysis method or a slurry polymerization method it can.

  Melt acidolysis involves heating the monomers first to form a molten solution of the reactants and then continuing the reaction to obtain a molten polymer. A vacuum may be applied to facilitate removal of volatiles (for example, acetic acid, water, etc.) by-produced in the final stage of condensation. This method is particularly preferably used in the present invention.

  The slurry polymerization method is a method of reacting in the presence of a heat exchange fluid, and a solid product is obtained in the state of being suspended in a heat exchange medium.

  In any of the melt acidolysis method and the slurry polymerization method, the polymerizable monomer component used in producing the liquid crystal polyester resin is subjected to the reaction as a modified form obtained by esterifying a hydroxyl group, that is, a lower acyl ester. You can also. The lower acyl group preferably has 2 to 5 carbon atoms, and more preferably 2 or 3 carbon atoms. Particularly preferred is a method of using an acetic acid ester of the monomer component for the reaction.

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

  A catalyst may be used as needed in any of the melt acidolysis method or the slurry polymerization method.

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

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

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

  The liquid crystalline polyester resin of the present invention preferably has a melt viscosity of 1 to 1000 Pa · s, more preferably 5 to 300 Pa · s, still more preferably 8 to 200 Pa · s, particularly preferably 1 to 1000 Pa · s. Is 12 to 150 Pa · s.

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

  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 of elasticity is more preferably 8.0 GPa or more, still more preferably 8.2 GPa or more, and usually 15.0 GPa or less.

  Furthermore, the liquid crystal polyester resin of the present invention has a flexural strength of 165 MPa or more measured according to ASTM D 790 using a strip-shaped test piece of length 65 mm × width 12.7 mm × thickness 2.0 mm. The elastic modulus is 9.0 GPa or more.

  The flexural 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, still more preferably 10.0 GPa or more, and usually 15.0 GPa or less.

  The present invention further provides a liquid crystalline polyester resin composition obtained by blending the liquid crystalline polyester resin of the present invention with one or more fillers of fibrous, plate or powder form. The filler may be appropriately selected from substances conventionally known to be used in resin compositions, according to the purpose of use, applications and the like of the liquid crystal polyester resin composition.

  As a fibrous filler, glass fiber, a silica alumina fiber, an alumina fiber, carbon fiber, an aramid fiber etc. are mentioned, for example. Among these, glass fiber is preferable from the point of being excellent in the balance of physical properties and cost.

  Examples of the plate-like or powder-like filler include talc, mica, graphite, wollastonite, calcium carbonate, dolomite, clay, glass flakes, glass beads, barium sulfate, titanium oxide and the like. Among these, talc is preferable because of its excellent balance between physical properties and cost.

  In the liquid crystal polyester resin composition of the present invention, the total blending amount of the filler is preferably 0.1 to 200 parts by mass, particularly 10 to 100 parts by mass with respect to 100 parts by mass of the liquid crystal polyester resin. When the blending amount of the filler exceeds 200 parts by mass, the molding processability of the liquid crystal polyester resin composition tends to be reduced, and the abrasion of the cylinder and the mold of the molding machine tends to be large.

  In the liquid crystal polyester resin or liquid crystal polyester resin composition of the present invention, the 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 fluorine resin, etc. Colorants such as dyes and pigments; antioxidants; heat stabilizers; ultraviolet light absorbers; antistatic agents; additives known to be used conventionally such as surfactants, etc. according to the purpose and application One or two or more may be combined and blended.

  With regard to those having an external lubricant effect such as higher fatty acid, higher fatty acid ester, higher fatty acid metal salt, fluorocarbon surfactant and the like, they may be adhered to pellets of liquid crystal polyester resin or liquid crystal polyester resin composition in advance for molding. .

  In the liquid crystal polyester resin composition of the present invention, all components such as fillers and additives are added to the polyester resin, and crystal melting of the liquid crystal polyester resin is performed using a Banbury mixer, a kneader, a single screw or twin screw extruder, etc. It can be prepared by melt-kneading from near the temperature at a temperature of crystal melting temperature + 100 ° C.

  The liquid crystalline polyester resin and the liquid crystalline polyester resin composition of the present invention thus obtained can be injection molded articles, films, sheets, non-woven fabrics, etc. by molding methods such as conventionally known injection molding, compression molding, extrusion molding and blow. Can be processed into

  The liquid crystal polyester resin and the liquid crystal polyester resin composition of the present invention are excellent in blister resistance, and excellent in mechanical properties such as heat resistance, tensile strength / tensile modulus, flexural strength / bending modulus, etc., connectors, camera modules, It is suitably used as a material of electric and electronic parts such as an antenna and a substrate.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.
In the examples, the following abbreviations represent the following compounds.
POB: 4-hydroxybenzoic acid BON 6: 6-hydroxy-2-naphthoic acid IPA: isophthalic acid NDA: 2, 6-naphthalenedicarboxylic acid HQ: hydroquinone

<Measurement of crystal melting temperature>
The measurement was performed using Exstar 6000 manufactured by Seiko Instruments Inc. as a differential scanning calorimeter. The liquid crystal polyester resin sample was measured under a temperature rising condition from room temperature to 20 ° C./min to observe an endothermic peak temperature (Tm1), and then 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 drop condition of 20 ° C./min, an endothermic peak when measured again under a temperature rise condition of 20 ° C./min is observed, and the temperature showing the peak top is the crystal melting of the liquid crystal polyester resin It was the temperature.

<Measurement of melt viscosity>
The melt viscosity under the conditions of a shear rate of 1000 sec ⁻¹ and 350 ° C. was measured using a 0.7 mmφ × 10 mm capillary with a melt viscosity measurement apparatus (Capirograph 1D manufactured by Toyo Seiki Co., Ltd.).

<Measurement of tensile strength and tensile modulus>
The dumbbell-shaped test pieces were obtained by injection molding at a crystal melting temperature + 20 to 40 ° C and a mold temperature of 70 ° C using an injection molding machine with a clamping pressure of 15 t (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.) A length of 63.5 mm × width 3.5 mm × thickness 2.0 mm) was produced. The tensile test was performed using an INSTRON 5567 (Instron Japan Company, universal testing machine manufactured by Instron Japan Ltd.) according to ASTM D638, at a chuck distance of 25.4 mm, and at a tensile speed of 5 mm / min.

<Measurement of flexural strength and flexural modulus>
Injection molding at a crystal melting temperature + 20 to 40 ° C and a mold temperature of 70 ° C using an injection molding machine with a clamping pressure of 15 t (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.), strip-shaped test pieces (Length 65 mm × width 12.7 mm × thickness 2.0 mm) was produced. The bending test was conducted using an INSTRON 5567 (Instron Japan Company, Ltd., universal testing machine) and a three-point bending test according to ASTM D 790 at a span distance of 40.0 mm and a compression speed of 1.3 mm / min.

<Izod impact strength measurement>
Injection molding at a crystal melting temperature + 20 to 40 ° C and a mold temperature of 70 ° C using an injection molding machine with a clamping pressure of 15 t (MINIMAT M26 / 15 manufactured by Sumitomo Heavy Industries, Ltd.), strip-shaped test pieces (Length 65 mm × width 12.7 mm × thickness 2.0 mm) was produced. Izod impact strength was measured in accordance with ASTM D256. The larger the value of Izod impact strength, the better the flexibility.

<Evaluation of blister occurrence>
Using an injection molding machine (NEX-15-1E manufactured by Nisshin Plastics Co., Ltd.), injection molding is performed at a crystal 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 6 mm in height and 0.2 mm in thickness were produced. The box-shaped test piece was heat-treated at 260 ° C. for 10 minutes in a gear oven, and after cooling, the number of blisters on the surface was visually observed. Thirty test pieces were evaluated in each test, and when the number of test pieces in which the blister occurred was 0 to 5, ○, 6 to 10, Δ, and 11 or more were x.

Example 1 (Reference Example)
In a reaction vessel equipped with a stirrer equipped with a torque meter and a distillation tube, POB: 205.6 g (22.9 mol%), BON 6: 939.4 g (76.8 mol%) and IPA: 3.2 g (0. 3 mol%) was charged, 1.03 moles of acetic anhydride were added to the hydroxyl groups (moles) of all monomers, and deacetic acid polymerization was performed under the following conditions.

  The temperature was raised from room temperature to 150 ° C. in 1 hour under a nitrogen gas atmosphere, and held at the same temperature for 30 minutes. Then, the temperature was rapidly raised to 210 ° C. while distilling off by-product acetic acid, and the temperature was maintained for 30 minutes. Thereafter, the temperature was raised to 350 ° C. over 4 hours, and then the pressure was reduced to 10 mmHg over 80 minutes. When a predetermined torque was indicated, the polymerization reaction was terminated, the contents of the reaction vessel were taken out, and pellets of a liquid crystal polyester resin were obtained by a grinder. The amount of acetic acid distilled off during the polymerization was almost as theoretical.

  Using the obtained pellets, the crystal melting temperature, melt viscosity, tensile strength, tensile modulus, flexural strength, flexural modulus, Izod impact strength and blister generation were measured and evaluated by the above method. The results are shown in Table 1.

[Examples 2 to 9 (Examples 2 to 4 and Examples 7 to 9 are reference examples) and Comparative Examples 1 to 5]
Pellets of a liquid crystal polyester resin were obtained in the same manner as in Example 1, except that POB, BON6, IPA, NDA and HQ were changed to the proportions (mol%) shown in Table 1. Using the obtained pellets, the crystal melting temperature, melt viscosity, tensile strength, tensile modulus, flexural strength, flexural modulus, Izod impact strength and blister generation were measured and evaluated by the above method. The results are shown in Table 1.

  In Comparative Example 4, when raising the temperature to 350 ° C. over 4 hours, the contents are solidified at the time of raising the temperature to 305 ° C. and the reaction becomes impossible because stirring becomes impossible, and a liquid crystal polyester resin is obtained. I could not

Example 10 (Reference Example)
10 parts by mass of glass fibers (chopped glass with a fiber diameter of 10.5 μm and a fiber length of 3 mm) and talc (average particles) as a filler using the resin of Example 1 as the liquid crystal polyester resin and 100 parts by mass of the liquid crystal polyester resin 20 parts by mass of a diameter of 19 μm was blended, and melt-kneaded by a twin-screw extruder (TEX-30 manufactured by Japan Steel Corp.) was pelletized to obtain pellets of a liquid crystal resin composition. Blister generation evaluation was performed by the above-mentioned method using the obtained pellet. The results are shown in Table 1.

Comparative Example 6
Pellets were obtained in the same manner as in Example 10 except that the resin of Comparative Example 1 was used as the liquid crystal polyester resin, and blister occurrence evaluation was performed. The results are shown in Table 1.

[Example 11]
In a reaction vessel equipped with a stirrer equipped with a torque meter and a distillation tube, POB: 205.6 g (22.9 mol%), BON 6: 939.4 g (76.8 mol%) and NDA: 4.2 g (0. 3 mol%) was charged, 1.03 moles of acetic anhydride were added to the hydroxyl groups (moles) of all monomers, and deacetic acid polymerization was performed under the following conditions.

  The temperature was raised from room temperature to 150 ° C. in 1 hour under a nitrogen gas atmosphere, and held at the same temperature for 30 minutes. Then, the temperature was rapidly raised to 210 ° C. while distilling off by-product acetic acid, and the temperature was maintained for 30 minutes. Thereafter, the temperature was raised to 350 ° C. over 4 hours, and then the pressure was reduced to 10 mmHg over 80 minutes. When a predetermined torque was indicated, the polymerization reaction was terminated, the contents of the reaction vessel were taken out, and pellets of a liquid crystal polyester resin were obtained by a grinder. The amount of acetic acid distilled off during the polymerization was almost as theoretical.

  Using the obtained pellets, the crystal melting temperature, melt viscosity, tensile strength, tensile modulus, flexural strength, flexural modulus, Izod impact strength and blister generation were measured and evaluated by the above method. The results are shown in Table 2.

[Examples 12 to 15 and Comparative Examples 7 to 10]
Pellets of a liquid crystal polyester resin were obtained in the same manner as in Example 1, except that POB, BON6, NDA and HQ were changed to the proportions (mol%) shown in Table 2. Using the obtained pellets, the crystal melting temperature, melt viscosity, tensile strength, tensile modulus, flexural strength, flexural modulus, Izod impact strength and blister generation were measured and evaluated by the above method. The results are shown in Table 2.

  In Comparative Example 9, when raising the temperature to 350 ° C. over 4 hours, the contents are solidified at the time of raising the temperature to 305 ° C. and the reaction becomes impossible because stirring becomes impossible, and a liquid crystal polyester resin is obtained. I could not

[Example 16]
10 parts by mass of glass fibers (chopped glass with a fiber diameter of 10.5 μm and a fiber length of 3 mm) and talc (average particles) as a filler using the resin of Example 11 as a liquid crystal polyester resin and 100 parts by mass of the liquid crystal polyester resin 20 parts by mass of a diameter of 19 μm was blended, and melt-kneaded by a twin-screw extruder (TEX-30 manufactured by Japan Steel Corp.) was pelletized to obtain pellets of a liquid crystal resin composition. Blister generation evaluation was performed by the above-mentioned method using the obtained pellet. The results are shown in Table 2.

  As shown in the above Tables, the liquid crystal polyester resin and the liquid crystal polyester resin composition according to each Example of the present invention were all excellent in mechanical properties, and good blister resistance at the time of reflow was obtained.

  On the other hand, when it did not depend on this invention (each comparative example), the blister resistance at the time of reflow was inadequate, and it was an evaluation result which can not be said that mechanical property or its balance is not enough. . In Comparative Example 5, the crystal melting temperature of the liquid crystal polyester resin was also lowered.

Claims (6)

Following formula:

[In the formula,
p, q, s, and t are composition ratios (mol%) of respective repeating units in the liquid crystal polyester resin, and satisfy the following conditions:
15 ≦ p ≦ 30,
70 ≦ q ≦ 85,
0.01 ≦ s + t <2, where s and t are each 0 or more and 2 or less, provided that these are simultaneously not 0]
Liquid crystal polyester resin comprised only from the repeating unit represented by these.   The liquid crystalline polyester resin according to claim 1, wherein a crystalline melting temperature measured by a differential scanning calorimeter is 290 to 340 ° C.   The tensile strength is 180 MPa or more, and the tensile elastic modulus is 7.7 GPa or more, measured according to ASTM D638, using a dumbbell-shaped test piece of 63.5 mm long × 3.5 mm wide × 2.0 mm thick The liquid crystal polyester resin according to claim 1 or 2, which is   The flexural strength is 165 MPa or more, and the flexural modulus is 9.0 GPa or more, measured according to ASTM D 790 using strip-shaped test pieces of length 65 mm × width 12.7 mm × thickness 2.0 mm The liquid crystalline polyester resin according to any one of claims 1 to 3.   A liquid crystalline polyester resin composition comprising 0.1 to 200 parts by mass of a fibrous, plate-like or powdery filler with respect to 100 parts by mass of the liquid crystalline polyester resin according to any one of claims 1 to 4.   A molded article comprising the liquid crystal polyester resin according to any one of claims 1 to 4 or the liquid crystal polyester resin composition according to claim 5.