JP6652223B1 - Liquid crystal polyester resin, method for producing the same, and molded article comprising the same - Google Patents

Abstract

A structural unit derived from an aromatic hydroxycarboxylic acid is 15 to 80 mol%, a structural unit derived from an aromatic diol is 7 to 40 mol%, based on 100 mol% of all structural units of a liquid crystal polyester resin. A liquid crystal polyester resin containing 7 to 40 mol% of a structural unit derived from an aromatic dicarboxylic acid and 0.01 to 5 mol% of at least one structural unit selected from the following structural units (I) and (II). Provided is a liquid crystal polyester resin which is excellent in thin-wall fluidity and dimensional stability while suppressing mold contamination, and a molded article made thereof. Embedded image

Description

  The present invention relates to a liquid crystal polyester resin and a molded article made thereof. More specifically, the present invention relates to a liquid crystal polyester resin capable of obtaining a molded article having excellent fluidity and dimensional stability while suppressing mold contamination during molding, and a molded article formed therefrom.

  The liquid crystal polyester resin has a liquid crystal structure and thus has excellent heat resistance, fluidity, and dimensional stability. For this reason, demand is expanding mainly for use in electrical and electronic parts such as connectors and relays that require these characteristics. In particular, with the recent increase in the performance of equipment, miniaturization and thinning of the above components have progressed, and further fluidity is required. For this reason, for example, it has been proposed to improve the fluidity by melt-kneading a liquid crystal polymer with a low molecular weight compound to obtain a liquid crystal polymer having a low melt viscosity (for example, see Patent Documents 1 and 2). Further, as a method of changing the chemical species of the molecular skeleton of the liquid crystal polyester resin, improvement in fluidity by liquid crystal polyester amide having a structure derived from acetaminophenone or 1,4-cyclohexanedicarboxylic acid has been proposed (for example, Patent Document 1). 3).

JP 2002-511513 A JP 2018-44108A International Publication No. WO 2013/115168

  On the other hand, when the liquid crystal polyester resin is made to have a low melt viscosity by the methods described in Patent Documents 1 and 2, the low heat resistance of the low molecular compound used itself is low, so that high processing required for molding the liquid crystal polyester resin is performed. At the temperature, there is a problem that the gas is decomposed to increase the gas, the mold is stained at the time of molding, and the dimensional stability is reduced. Also, the thin-wall fluidity was insufficient. Further, the liquid crystal polyester amide resin described in Patent Document 3 also has problems in mold contamination and dimensional stability, and also has insufficient thin-wall fluidity.

  The present invention solves the above-mentioned problems, and provides a liquid crystal polyester resin capable of obtaining a molded product excellent in fluidity and dimensional stability, while suppressing mold contamination during molding, and a molded product thereof. As an issue.

  The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, by using a liquid crystal polyester resin containing a small amount of a specific structural unit, while suppressing mold contamination during molding, fluidity and dimensional stability. The present inventors have found that a molded article excellent in the above can be obtained, and arrived at the present invention.

The invention is:
(1) Based on 100 mol% of the total structural units of the liquid crystal polyester resin, 15 to 80 mol% of a structural unit derived from an aromatic hydroxycarboxylic acid, 7 to 40 mol% of a structural unit derived from an aromatic diol, A liquid crystal polyester resin comprising 7 to 40% of a structural unit derived from an aromatic dicarboxylic acid and 0.01 to 5% by mole of at least one structural unit selected from the following structural units (I) and (II).

(2) The liquid crystal polyester resin contains a structural unit (III) as a structural unit derived from an aromatic hydroxycarboxylic acid, and a structural unit (IV) shown below as a structural unit derived from an aromatic dicarboxylic acid. The liquid crystal polyester resin according to (1), wherein the sum of (III) and the structural unit (IV) is 60 to 80 mol% based on 100 mol% of all the structural units of the liquid crystal polyester resin.

(3) The liquid crystal polyester resin contains the following structural unit (V) as a structural unit derived from an aromatic diol, and the structural unit (V) is 2 to 20% based on 100 mol% of all the structural units of the liquid crystal polyester resin. % Of the liquid crystal polyester resin according to (1) or (2).

(4) The liquid crystal polyester according to any one of (1) to (3), wherein at least one structural unit selected from the structural units (I) and (II) contains the structural unit (II) as an essential component. resin.
( 5 ) A liquid crystal polyester containing no structural unit selected from the structural units (I) and (II) and a compound having at least one type of structure selected from the structural units (I) and (II) are melt-kneaded. A method for producing a liquid crystal polyester resin, whereby the liquid crystal polyester resin according to any one of (1) to ( 5 ) is obtained .
( 7 ) A liquid crystal polyester resin composition comprising 10 to 200 parts by weight of a filler with respect to 100 parts by weight of the liquid crystal polyester resin according to any one of (1) to ( 4 ).
( 7 ) 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 (7).
( 8 ) The molded article according to ( 8 ), wherein the molded article is selected from the group consisting of a connector, a relay, a switch, a coil bobbin, a lamp socket, a camera module, and an integrated circuit sealing material.

  ADVANTAGE OF THE INVENTION According to the liquid crystal polyester resin of this invention, the molded article excellent in fluidity and dimensional stability can be obtained, suppressing the mold dirt at the time of shaping | molding. Such a resin is particularly suitable for electric / electronic parts and mechanical parts such as connectors, relays, switches, coil bobbins, lamp sockets, camera modules, and integrated circuit sealing materials having a thin box or cylindrical shape.

FIG. 3 is a perspective view of a connector molded product manufactured in an example and a conceptual diagram showing a measurement site of a warpage amount.

  Hereinafter, the present invention will be described in detail.

<Liquid crystal polyester resin>
The liquid crystal polyester resin used in the present invention is a polyester that forms an anisotropic molten phase. Examples of the liquid crystal polyester resin include a polyester composed of a structural unit selected from an oxycarbonyl unit, a dioxy unit, a dicarbonyl unit, and the like described below so as to form an anisotropic molten phase.

  Next, the structural units constituting the liquid crystal polyester resin will be described.

  The liquid crystal polyester resin of the present invention contains 15 to 80 mol% of oxycarbonyl units, that is, structural units derived from aromatic hydroxycarboxylic acid, based on 100 mol% of all structural units of the liquid crystal polyester resin. When the content of the oxycarbonyl unit is less than 15 mol%, liquid crystallinity is impaired, so that the fluidity of the liquid crystal polyester resin is reduced and the dimensional stability is also reduced. In light of improvement in fluidity and dimensional stability, the content of the oxycarbonyl unit is preferably equal to or greater than 20 mol%, and more preferably equal to or greater than 25 mol%. On the other hand, when the content of the oxycarbonyl unit is more than 80 mol%, it is difficult to control the crystallinity and melting point of the liquid crystal polyester resin, and the fluidity and the dimensional stability decrease. From the viewpoint of improving fluidity and dimensional stability, the content of the oxycarbonyl unit is preferably equal to or less than 75 mol%, and more preferably equal to or less than 70 mol%.

  Specific examples of the oxycarbonyl unit include structural units derived from p-hydroxybenzoic acid, m-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and the like.

  The liquid crystal polyester resin of the present invention contains 7 to 40 mol% of dioxy units, that is, structural units derived from aromatic diol, based on 100 mol% of all structural units of the liquid crystal polyester resin. When the content of the dioxy unit is less than 5 mol%, it is difficult to control the crystallinity and melting point of the liquid crystal polyester resin, and the fluidity and the dimensional stability decrease. From the viewpoint of improving fluidity and dimensional stability, the content of dioxy units is preferably 10 mol% or more, and more preferably 15 mol% or more. On the other hand, when the content of the dioxy unit is more than 40 mol%, the liquid crystallinity is impaired, so that the fluidity of the liquid crystal polyester resin is reduced and the dimensional stability is also reduced. In light of improvement in fluidity and dimensional stability, the content of the dioxy unit is preferably equal to or less than 37 mol%, and more preferably equal to or less than 35 mol%.

  In addition, the liquid crystal polyester resin of the present invention includes, as a dioxy unit, at least one structural unit selected from the following structural units (I) and (II) in addition to the structural unit derived from the aromatic diol having the content described above. And 0.01 to 5 mol% based on 100 mol% of all structural units of the liquid crystal polyester resin. The structural units (I) and (II) are structural units derived from 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, respectively. When the content of these structural units is less than 0.01 mol%, thin-wall fluidity and dimensional stability are reduced. From the viewpoint of excellent thin-wall fluidity and dimensional stability, the content of these structural units is preferably at least 0.03 mol%, more preferably at least 0.05 mol%. On the other hand, when the content of these structural units is more than 5 mol%, mold contamination occurs during molding, and thin-wall fluidity and dimensional stability also decrease. The content of these structural units is preferably 3% or less, and more preferably 1% or less, from the viewpoint of suppressing mold stains during molding and having excellent thin-wall fluidity and dimensional stability. Further, the structural unit (I) and the structural unit (II) may have either one of the structural units and the other structural unit may be 0 mol%. In addition, it is preferable to include the structural unit (II) as an essential component from the viewpoint of excellent thin fluidity and dimensional stability.

  Examples of the structural unit derived from an aromatic diol include 4,4′-dihydroxybiphenyl, hydroquinone, resorcinol, t-butylhydroquinone, phenylhydroquinone, chlorohydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 3,4'-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide, 4,4 And structural units derived from '-dihydroxybenzophenone. It is preferable to use a structural unit selected from structural units derived from 4,4'-dihydroxybiphenyl and hydroquinone from the viewpoint of excellent fluidity and dimensional stability while suppressing mold contamination during molding. Further, it has a structural unit derived from an aliphatic diol such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, or neopentyl glycol in a range that does not impair the liquid crystallinity and properties. be able to.

  The liquid crystal polyester resin of the present invention contains, as dicarbonyl units, 7 to 40 mol% of structural units derived from aromatic dicarboxylic acid based on 100 mol% of all structural units of the liquid crystal polyester resin. When the content of the structural unit derived from the aromatic dicarboxylic acid is less than 7 mol%, it is difficult to control the crystallinity and melting point of the liquid crystal polyester resin, and the fluidity and dimensional stability are reduced. From the viewpoint of improving fluidity and dimensional stability, the content of the structural unit derived from the aromatic dicarboxylic acid is preferably 10 mol% or more, and more preferably 15 mol% or more. On the other hand, when the content of the structural unit derived from the aromatic dicarboxylic acid is more than 40 mol%, the liquid crystallinity is impaired, so that the fluidity of the liquid crystal polyester resin is reduced and the dimensional stability is also reduced. From the viewpoint of improving the fluidity and dimensional stability, the content of the structural unit derived from the aromatic dicarboxylic acid is preferably 37 mol% or less, more preferably 35 mol% or less.

  Examples of the structural unit derived from an aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 3,3′-diphenyldicarboxylic acid, and 2,2 ′ -Diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid, 4,4'-diphenyl ether Structural units derived from dicarboxylic acids and the like are included. It is preferable to use a structural unit selected from structural units derived from terephthalic acid and isophthalic acid from the viewpoint of excellent fluidity and dimensional stability while suppressing mold contamination during molding. Also, structural units derived from aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecandioic acid, and hexahydroterephthalic acid; and alicyclic rings such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid. A structural unit or the like derived from the formula dicarboxylic acid may be further included in a range that does not impair the liquid crystallinity and characteristics.

  Further, in addition to the above structural units, structural units formed from p-aminobenzoic acid, p-aminophenol, and the like may further have a range in which liquid crystallinity and characteristics are not impaired.

  The raw material monomer constituting each of the above structural units is not particularly limited as long as it is a structure capable of forming each structural unit, but an acylated product of a hydroxyl group of each structural unit, an esterified product of a carboxyl group of each structural unit, and an acid halide Carboxylic acid derivatives such as chlorides and acid anhydrides may be used.

  The liquid crystal polyester resin of the present invention includes the following structural unit (III) as a structural unit derived from an aromatic hydroxycarboxylic acid, and the following structural unit (IV) as a structural unit derived from an aromatic dicarboxylic acid. The total content of the unit (III) and the structural unit (IV) is preferably from 60 to 80 mol% based on 100 mol% of all the structural units of the liquid crystal polyester resin. After controlling the crystallinity and melting point of the liquid crystal polyester resin, the total content of the structural units (III) and (IV) is preferably 63 mol% or more from the viewpoint of excellent thin-wall fluidity and dimensional stability. More preferably, it is at least 67 mol%. On the other hand, after controlling the crystallinity and melting point of the liquid crystal polyester resin, the total content of the structural units (III) and (IV) is preferably 78 mol from the viewpoint of excellent thin-wall fluidity and dimensional stability. % Or less. The structural unit (III) and the structural unit (IV) may have one of the structural units, and the other structural unit may be 0 mol%. From the viewpoint of control, it is preferable that both are contained in excess of 0 mol%.

  The content of the structural unit (III) is preferably at least 30 mol%, more preferably at least 50 mol%, based on 100 mol% of the total structural units of the liquid crystal polyester resin, from the viewpoint of excellent thin-wall fluidity and dimensional stability. . On the other hand, after controlling the crystallinity and melting point of the liquid crystal polyester resin, the content of the structural unit (III) is preferably 70 mol% or less and 65 mol% or less from the viewpoint of excellent thin-wall fluidity and dimensional stability. Is preferred.

  The content of the structural unit (IV) is preferably 5 mol% or more, more preferably 10 mol% or more, from the viewpoint of excellent thin-wall fluidity and dimensional stability, based on 100 mol% of all the structural units of the liquid crystal polyester resin. On the other hand, the content of the structural unit (IV) is preferably 30 mol% or less, and more preferably 20 mol% or less, from the viewpoint of excellent thin-wall fluidity and dimensional stability.

  The liquid crystal polyester resin of the present invention contains the following structural unit (V) as a structural unit derived from an aromatic diol, and the structural unit (V) is 2 to 20 mol based on 100 mol% of the total amount of the liquid crystal polyester resin. %. The structural unit (V) is a structural unit derived from hydroquinone. By containing the structural unit (V) in an amount of 2 mol% or more, thin-wall fluidity and dimensional stability can be further improved. The content of the structural unit (V) is more preferably at least 4 mol%, further preferably at least 7.5 mol%. On the other hand, by containing the structural unit (V) in an amount of 20 mol% or less, thin-wall fluidity and dimensional stability can be further improved. The content of the structural unit (V) is more preferably 15 mol% or less, and further preferably 12 mol% or less.

  The liquid crystal polyester resin of the present invention contains the following structural unit (VI) as a structural unit derived from an aromatic diol, and the structural unit (VI) is 3 to 30 with respect to 100 mol% of the total amount of the liquid crystal polyester resin. It is preferred that the content be contained in a mole%. The structural unit (VI) is a structural unit derived from 4,4'-dihydroxybiphenyl. By containing 3 mol% or more of the structural unit (VI), the crystallinity and melting point of the liquid crystal polyester resin can be controlled, and the heat resistance can be improved. The content of the structural unit (VI) is preferably at least 5 mol%, more preferably at least 7 mol%. On the other hand, by containing the structural unit (VI) in an amount of 30 mol% or less, the crystallinity and melting point of the liquid crystal polyester resin can be controlled, and the moldability can be improved. The content of the structural unit (VI) is more preferably 25 mol% or less, and still more preferably 20 mol% or less.

  The liquid crystal polyester resin of the present invention contains the following structural unit (VII) as a structural unit derived from an aromatic dicarboxylic acid, and the structural unit (VII) is 1 to 100 mol% of the total structural unit of the liquid crystal polyester resin. It is preferable to contain 10 mol%. The following structural unit (VII) is a structural unit derived from isophthalic acid. By containing the structural unit (VII) in an amount of 1 mol% or more, the crystallinity and melting point of the liquid crystal polyester resin can be controlled, and the moldability can be improved. The content of the structural unit (VII) is preferably at least 2 mol%, more preferably at least 3 mol%. On the other hand, by containing the structural unit (VII) in an amount of 10 mol% or less, the crystallinity and melting point of the liquid crystal polyester resin can be controlled, and the heat resistance can be improved. The content of the structural unit (VII) is more preferably 9 mol% or less, and still more preferably 8 mol% or less.

  The content of each structural unit of the liquid crystal polyester resin in the present invention is determined by pulverizing liquid crystal polyester pellets, adding tetramethylammonium hydroxide, and performing pyrolysis GC / MS measurement using GCMS-QP5050A manufactured by Shimadzu. be able to. The content of the structural unit not detected or below the detection limit is calculated as 0 mol%.

  The melting point (Tm) of the liquid crystal polyester resin of the present invention is preferably 220 ° C. or higher, more preferably 270 ° C. or higher, even more preferably 300 ° C. or higher from the viewpoint of heat resistance. On the other hand, the melting point (Tm) of the liquid crystal polyester resin is preferably 360 ° C. or lower, more preferably 355 ° C. or lower, and more preferably 350 ° C., from the viewpoint of suppressing deterioration of the liquid crystal polyester resin during processing and suppressing mold contamination during molding. C. or lower is more preferable.

The melting point (Tm) is measured by differential scanning calorimetry. Specifically, first, an endothermic peak temperature (Tm ₁ ) is observed by heating the polymerized polymer from room temperature under a heating condition of 20 ° C./min. After observation of an endothermic peak temperature (Tm _1), holding the polymer for 5 minutes at a temperature of the endothermic peak temperature _(Tm 1) + 20 ℃. Thereafter, the polymer is cooled to room temperature under a temperature-lowering condition of 20 ° C./min. The endothermic peak temperature (Tm ₂ ) is observed by heating the polymer again at a heating condition of 20 ° C./min. The melting point (Tm) refers to the endothermic peak temperature (Tm ₂ ) in the _second heating process.

  The melt viscosity of the liquid crystal polyester resin of the present invention is preferably 1 Pa · s or more, more preferably 3 Pa · s or more, even more preferably 5 Pa · s or more from the viewpoint of suppressing mold contamination during molding. On the other hand, from the viewpoint of excellent thin-wall fluidity, the melt viscosity of the liquid crystal polyester resin is preferably 50 Pa · s or less, preferably 20 Pa · s or less, and more preferably 10 Pa · s or less.

  The melt viscosity is a value measured by a Koka type flow tester at a temperature of the melting point (Tm) of the liquid crystal polyester resin + 20 ° C. and a shear rate of 1000 / sec.

<Production method of liquid crystal polyester resin>
The method for producing the liquid crystal polyester resin used in the present invention includes the following method.
(A) A method of adding a compound having at least one type of structure selected from the structural unit (I) and the structural unit (II) when producing according to a known polyester polycondensation method described below.
(B) A liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II) is produced according to a known polyester polycondensation method described below, and then the structural unit (I) and the structural unit ( A method of blending a compound having at least one structure selected from II).

  Since a suitable transesterification reaction with the liquid crystal polyester resin can further improve thin-wall fluidity and dimensional stability while suppressing mold contamination during molding, (B) the structural units (I) and (II) )), A method is preferred in which a liquid crystal polyester resin containing no structural unit selected from the above is produced, and then a compound having at least one type of structure selected from the structural units (I) and (II) is blended. As a method of blending these, a method of melt-kneading them is preferable. The detailed manufacturing method will be described later.

  Examples of the compound having at least one type of structure selected from the structural unit (I) and the structural unit (II) include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and an oxycarbonyl unit or diamine in the diol compound. Compounds in which one or more structural units such as a carbonyl unit which can constitute a liquid crystal polyester resin are ester-bonded are exemplified. Among them, from the viewpoint of suppressing mold contamination during molding, 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol having two hydroxyl groups, and oxycarbonyl units capable of forming a liquid crystal polyester resin in the diol compound Is preferably a compound having one or more ester bonds. Furthermore, from the viewpoint of having high heat resistance and suppressing thermal decomposition during polycondensation and melt kneading, while suppressing mold contamination during molding, from the viewpoint of being excellent in thin-wall fluidity and dimensional stability, the above-mentioned diol compound has a liquid crystal polyester. Compounds in which one or more oxycarbonyl units capable of constituting a resin are ester-bonded are more preferable, and compounds in which two or more oxycarbonyl units are ester-bonded are particularly preferable. A compound in which an oxycarbonyl unit is further bonded next to the oxycarbonyl unit may be used, but the upper limit of the number of bonded oxycarbonyl units does not generate an infusible substance derived from a long chain of a rigid oxycarbonyl unit. From the viewpoint, 10 or less is preferable, and 7 or less is more preferable.

  Compounds in which one or more oxycarbonyl units capable of constituting a liquid crystal polyester resin are ester-bonded to the diol compound include, for example, cyclohexane-1,4-diylbis (methylene) bis (4-hydroxybenzoate), (4- (hydroxy Methyl) cyclohexyl) methyl 4-hydroxybenzoate, 4-hydroxycyclohexyl 4-hydroxybenzoate, cyclohexane-1,4-diylbis (4-hydroxybenzoate) and the like.

  These compounds can be prepared by a method known to those skilled in the art using 1,4-cyclohexanediol or 1,4-cyclohexanedimethanol and an aromatic hydroxycarboxylic acid, for example, a method described in JP-T-2008-544954. Can be produced by esterification using Specifically, 1,4-cyclohexanediol or 1,4-cyclohexanedimethanol is reacted with an aromatic hydroxycarboxylic acid by heating to reflux in a solvent in the presence of sulfuric acid, and then purified by washing with methanol. By doing so, a compound in which one or more oxycarbonyl units capable of constituting a liquid crystal polyester resin are ester-bonded to the diol compound can be obtained.

  The molecular weight of the compound having at least one structure selected from the structural unit (I) and the structural unit (II) has a molecular weight of 200 from the viewpoint of excellent thin-wall fluidity and dimensional stability while suppressing mold contamination during molding. Or more is preferable, 230 or more is more preferable, and 250 or more is further preferable. On the other hand, when the diol compound is a compound in which one or more structural units capable of constituting the liquid crystal polyester resin are ester-bonded, the molecular weight is preferably 1000 or less from the viewpoint of suppressing the generation of infusible substances due to long chains of rigid structural units. Preferably, it is 700 or less, more preferably 500 or less.

  When the liquid crystal polyester resin is produced by the method (B), the content of the structural unit (I) and the content of the structural unit (I) and the structural unit (II) are adjusted so that the content is at least one type selected from the structural unit (I) and the structural unit (II). A compound having at least one structure selected from the structural units (I) and (II) is preferably added to 100 parts by weight of the liquid crystal polyester resin containing no structural unit selected from (II), preferably 0.01%. It is preferable that the compounding amount be at least 0.03 parts by weight, more preferably at least 0.05 parts by weight, more preferably at least 0.05 parts by weight. On the other hand, at least one structure selected from the structural units (I) and (II) is added to 100 parts by weight of the liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II). It is preferable to compound the compound having the compound in an amount of preferably 10 parts by weight or less, more preferably 7 parts by weight or less, and still more preferably 3 parts by weight or less.

  Known polyester polycondensation methods include structural units derived from p-hydroxybenzoic acid, structural units derived from 4,4′-dihydroxybiphenyl, structural units derived from hydroquinone, structural units derived from terephthalic acid, and Taking a liquid crystal polyester resin comprising a structural unit derived from isophthalic acid as an example, the following may be mentioned.

  (1) A method for producing a liquid crystal polyester resin from p-acetoxybenzoic acid, 4,4'-diacetoxybiphenyl, diacetoxybenzene and terephthalic acid and isophthalic acid by a deacetic acid condensation polymerization reaction.

  (2) Liquid crystal polyester by reacting p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, hydroquinone, terephthalic acid, and isophthalic acid with acetic anhydride to acetylate the phenolic hydroxyl group, followed by deacetic acid polymerization to carry out acetic acid polymerization. A method of manufacturing a resin.

  (3) A method for producing a liquid crystal polyester resin from phenyl p-hydroxybenzoate, 4,4'-dihydroxybiphenyl, hydroquinone, diphenyl terephthalate and diphenyl isophthalate by a phenol removal polycondensation reaction.

  (4) A predetermined amount of diphenyl carbonate is reacted with p-hydroxybenzoic acid, terephthalic acid and isophthalic acid to form phenyl esters, and 4,4′-dihydroxybiphenyl and hydroquinone are added, followed by dephenol polycondensation reaction. A method for producing a liquid crystal polyester resin.

  Above all, (2) p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, hydroquinone, terephthalic acid, and isophthalic acid are reacted with acetic anhydride to acetylate the phenolic hydroxyl group, and then by deacetic acid polycondensation reaction. A method for producing a liquid crystal polyester resin is preferably used because it is industrially excellent in controlling the terminal structure of the liquid crystal polyester resin and controlling the degree of polymerization.

  As a method for producing a liquid crystal polyester resin, the polycondensation reaction can be completed by a solid phase polymerization method. Examples of the solid phase polymerization method include the following methods. First, a polymer or oligomer of a liquid crystal polyester resin is pulverized by a pulverizer. The reaction is completed by heating the pulverized polymer or oligomer under a nitrogen stream or under reduced pressure to polycondensate to a desired degree of polymerization. The heating can be performed in the range of the melting point of the liquid crystal polyester of -50 ° C to -5 ° C (for example, 200 to 300 ° C) for 1 to 50 hours.

  Although the polycondensation reaction of the liquid crystal polyester resin proceeds without a catalyst, stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, metal magnesium and the like can be used as a catalyst.

<Liquid crystal polyester resin composition>
The liquid crystal polyester resin of the present invention can also be used as a resin composition containing a filler in order to impart mechanical strength and other properties of the liquid crystal polyester resin. The filler is not particularly limited, and examples thereof include a fibrous filler, a whisker-like filler, a plate-like filler, a powdery filler, and a granular filler. Specifically, the fibrous filler and the whisker-like filler include glass fiber; PAN-based or pitch-based carbon fiber; metal fiber such as stainless steel fiber, aluminum fiber and brass fiber; aromatic polyamide fiber and liquid crystal polyester fiber. Gypsum fiber, ceramic fiber, asbestos fiber, zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, barium titanate whisker, aluminum borate whisker, nitriding Silicon whiskers, needle-like titanium oxide and the like can be mentioned. Examples of the plate-like filler include mica, talc, kaolin, glass flake, clay, molybdenum disulfide, and wollastenite. Examples of the powdery filler and the particulate filler include silica, glass beads, titanium oxide, zinc oxide, calcium polyphosphate, and graphite. The surface of the filler may be treated with a known coupling agent (for example, a silane coupling agent, a titanate coupling agent, or the like) or another surface treatment agent. Two or more fillers may be used in combination.

  Among the above-mentioned fillers, glass fibers are preferred because they are excellent in mechanical strength such as tensile strength and bending strength, heat resistance and dimensional stability. The type of glass fiber is not particularly limited as long as it is generally used for reinforcing a resin, and examples thereof include long fiber type and short fiber type chopped strands and milled fibers. In addition, it is preferable to use mica from the viewpoint of excellent thin-wall fluidity.

  The surface of the filler may be treated with a known coupling agent (for example, a silane coupling agent, a titanate coupling agent, or the like) or another surface treatment agent. Further, the glass fiber may be covered or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin.

  The content of the filler is preferably from 10 to 200 parts by weight based on 100 parts by weight of the liquid crystal polyester resin. If the filler content is 10 parts by weight or more, the mechanical strength of the molded article can be improved, which is preferable. It is more preferably at least 15 parts by weight, even more preferably at least 20 parts by weight. On the other hand, when the content of the filler is 200 parts by weight or less, a liquid crystal polyester resin composition excellent in moldability and thin-wall fluidity can be obtained, which is preferable. 150 parts by weight or less is more preferable, and 100 parts by weight or less is further preferable.

  The liquid crystal polyester resin composition of the present invention further includes an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphite, thioethers and their substituted products) as long as the effects of the present invention are not impaired. UV absorbers (eg, resorcinol, salicylate), phosphites, anti-coloring agents such as hypophosphite, lubricants and release agents (montanic acid and its metal salts, its esters, its half esters, stearyl alcohol, Stearamide, polyethylene wax, etc.), coloring agents including dyes or pigments, conductive agents or coloring agents such as carbon black, crystal nucleating agents, plasticizers, and flame retardants (brominated flame retardants, phosphorous flame retardants, red phosphorus, silicone-based flame retardants) General additives selected from flame retardants, flame retardant aids, and antistatic agents It can be.

<Production method of liquid crystal polyester resin composition>
As a method for obtaining the liquid crystal polyester resin composition of the present invention, for example, a liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II) may be added to the liquid crystal polyester resin from the structural unit (I) and the structural unit (II). A dry blending method in which a compound having at least one selected structure, a filler and other solid additives are blended, and a liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II) , A compound having at least one type of structure selected from the structural unit (I) and the structural unit (II), a filler, and other liquid additives, a solution compounding method, a structural unit (I) and a structural unit A compound having at least one type of structure selected from (II), a filler and other additives are selected from structural units (I) and (II). A method of adding during the polymerization of a liquid crystal polyester resin containing no structural unit, or a liquid crystal polyester resin containing no structural unit selected from structural units (I) and (II), and a liquid crystal polyester resin selected from structural unit (I) and structural unit (II) For example, a method of melt-kneading at least one compound having at least one structure, a filler, and other additives can be used. Among them, a method of melt-kneading is preferred. Known methods can be used for the melt-kneading. For example, using a Banbury mixer, a rubber roll machine, a kneader, a single-screw or twin-screw extruder, or the like, each of the above components is melt-kneaded at a melting point of the liquid crystal polyester resin + 50 ° C. or lower to obtain a liquid crystal polyester resin composition. . Of these, melt kneading using a twin-screw extruder is preferred.

  The twin-screw extruder is preferably provided with one or more kneading portions, and more preferably provided with two or more kneading portions, in order to improve the dispersibility of the liquid crystal polyester resin and the filler. When the liquid crystal polyester resin is produced by the above method (B), by providing the kneading portion as described above, the liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II); The dispersibility of the compound having at least one type of structure selected from the structural unit (I) and the structural unit (II) is improved, and the two are appropriately transesterified, thereby suppressing mold contamination during molding. In addition, thin-wall fluidity and dimensional stability can be further improved. For example, when a filler is added from a side feeder, the kneading portion is provided at one or more locations upstream of the side feeder of the filler when the filler is added from a side feeder. In order to improve the dispersibility with the material, it is preferable to install one or more at a downstream side of the side feeder at a total of two or more places.

  Further, it is preferable to provide a vent in order to remove moisture in the twin-screw extruder and decomposition products generated during kneading. For example, when a filler is added from a side feeder, one or more locations upstream of the side feeder into which the filler is charged are used for melting and kneading when the filler is added from a side feeder. In order to remove cracked gas and carry-in air at the time of supplying the filler, it is preferable to install one or more two or more locations downstream of the side feeder. The vent may be under normal pressure or under reduced pressure.

  The kneading method includes (1) a liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II), and having at least one type of structure selected from the structural units (I) and (II). A method in which a compound, a filler and other additives are collectively charged from a feeder and kneaded (batch kneading method), (2) a liquid crystal polyester containing no structural unit selected from structural units (I) and (II) A resin, a compound having at least one type of structure selected from the structural unit (I) and the structural unit (II), and other additives are charged from a feeder and kneaded, and then the filler and other additives are added to the side. A method of adding and kneading from a feeder (side feed method), (3) a liquid crystal containing no structural unit selected from the structural units (I) and (II) A master pellet containing a high concentration of a compound having at least one structure selected from a ester resin, a structural unit (I) and a structural unit (II), and other additives is prepared. A method in which the master pellet is kneaded with a liquid crystal polyester resin and a filler (master pellet method) is exemplified. Any method may be used.

  The liquid crystal polyester resin composition of the present invention is obtained by performing known melt molding such as injection molding, injection compression molding, compression molding, extrusion molding, blow molding, press molding, spinning, etc., to obtain an excellent surface appearance (color tone) and machine. It can be processed into a molded product having mechanical properties, heat resistance and flame retardancy. Examples of the molded product include injection molded products, extrusion molded products, press molded products, sheets, pipes, unstretched films, uniaxially stretched films, various films such as biaxially stretched films, unstretched yarns, and superstretched yarns. Various fibers and the like can be mentioned. In particular, an injection molded product is preferable from the viewpoint of workability.

  Molded products obtained by molding the liquid crystal polyester resin or liquid crystal polyester composition of the present invention include, for example, various gears, various cases, sensors, LED lamps, connectors, sockets, resistors, relay cases, relay bases, and relay spools. , Switches, coil bobbins, camera modules, capacitors, variable condenser cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, Electrical and electronic parts such as housings, semiconductors, sealing materials for integrated circuits, liquid crystal display parts, FDD carriages, FDD chassis, HDD parts, motor brush holders, parabolic antennas, computer-related parts, etc .; VT Parts, TV parts, irons, hair dryers, rice cooker parts, microwave parts, audio parts, audio equipment parts such as audio / laser discs / compact discs; lighting parts, refrigerator parts, air conditioner parts, personal computer parts, etc. Home and office electrical products parts; office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, washing jigs, oil-less bearings, stern bearings, underwater bearings, and other bearings, motor parts, etc. Optical parts such as microscopes, binoculars, cameras, watches, etc., precision equipment parts; alternator terminals, alternator connectors, IC regulators, potentiometer bases for light dimmers, various valves such as exhaust gas valves, fuel-related parts Exhaust system Various intake system pipes, air intake nozzle snorkel, intake manifold, fuel pump, engine cooling water joint, carburetor main body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, air Flow meter, brake butt wear sensor, thermostat base for air conditioner, motor insulator for air conditioner, motor insulator for vehicle such as power window, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor Related parts, Distributor, Starter switch, Starter relay, Transmission Wire harness, window washer nozzle, air conditioner panel switch board, fuel related solenoid valve coil, fuse connector, horn terminal, electrical component insulation board, step motor rotor, lamp bezel, lamp socket, lamp reflector, lamp housing, Automotive and vehicle related parts such as brake piston, solenoid bobbin, engine oil filter, ignition device case, etc .; bottles for various chemicals such as shampoo, rinse, liquid soap, detergent; chemical storage tank, gas storage tank, coolant tank, Tanks for storing chemicals and gases such as oil transfer tanks, disinfectant tanks, blood transfusion pump tanks, fuel tanks, canisters, washer liquid tanks, oil reservoir tanks; medical equipment parts; soy sauce, sauces, ketchup, mayo Seasonings such as meat and dressings, fermented foods such as miso and vinegar, oil and fat foods such as salad oil, sake, beer, mirin, whiskey, shochu, wine and other alcoholic beverages, carbonated drinks, juices, sports drinks, milk, coffee drinks It can be used for food storage containers such as oolong tea, black tea, and soft drinks such as mineral water; and tanks and bottle-shaped molded articles as general living equipment parts, or hollow containers such as these tanks.

  Above all, connectors, relays, switches, and coil bobbins that have metal terminal sections and have thin-walled box-shaped or cylindrical shapes because they have excellent thin-wall fluidity and dimensional stability while suppressing mold contamination during molding It is particularly useful for electric and electronic parts such as lamp sockets, camera modules, and sealing materials for integrated circuits.

  Hereinafter, the present invention will be described using examples, but the present invention is not limited to the examples. In the examples, the composition and property evaluation of the liquid crystal polyester resin were measured by the following methods.

(1) Composition analysis of liquid crystal polyester resin To 0.1 mg of the crushed liquid crystal polyester resin pellets, 2 μL of a 25% methanol solution of tetramethylammonium hydroxide was added, and pyrolysis GC / MS measurement was performed using GCMS-QP5050A manufactured by Shimadzu. The composition ratio of each component in the liquid crystal polyester resin was determined.

(2) Melting point (Tm) of liquid crystal polyester resin
After observing the endothermic peak temperature (Tm ₁ ) observed when the temperature of the liquid crystal polyester resin was increased from room temperature under a heating condition of 20 ° C./min using a differential scanning calorimeter DSC-7 (manufactured by PerkinElmer). , Tm ₁ + 20 ° C. for 5 minutes, and once cooled to room temperature under a temperature-lowering condition of 20 ° C./min, and then heated again at a temperature-raising condition of 20 ° C./min. Tm ₂ ) was taken as the melting point. In the following production examples, the melting point (Tm ₂ ) is described as Tm.

(3) Melt viscosity of liquid crystal polyester resin Melting of liquid crystal polyester resin using a Koka type flow tester CFT-500D (orifice 0.5φ × 10 mm) (manufactured by Shimadzu Corporation) under conditions of Tm + 20 ° C. and shear rate 1000 / s. The viscosity was measured.

(4) Thin-wall fluidity The pellets obtained in each of the Examples and Comparative Examples were hot-air dried using a hot-air dryer at 150 ° C. for 3 hours, and then supplied to a FANUC α30C injection molding machine manufactured by FANUC Co., Ltd. Assuming that the melting point of the liquid crystal polyester is + 20 ° C., the mold temperature is 90 ° C., the injection pressure is 100 MPa, the speed is the minimum filling speed, the pitch between terminals is 0.4 mm as shown in FIG. 3) A connector molded product of 0.2 mm in outer dimensions and 3 mm in width × 2 mm in height × 30 mm in length was obtained. FIG. 1a is a perspective view of the connector molded product. A liquid crystal polyester resin or a resin composition was filled from a pin gate G1 (gate diameter 0.3 mm) provided on one short surface 2 of the connector molded product. 500 shot molding was performed, and the number of unfilled occurrences was evaluated for the filling property of the corner of the wall facing the gate. The corner portion is a portion where unfilling is likely to occur due to variation in the filling amount, and the smaller the number of unfilled occurrences, the better the thin wall fluidity.

(5) Mold stainability To 100 parts by weight of the pellets obtained in each of Examples and Comparative Examples, 0.05 parts by weight of a release agent (Licowax E, manufactured by Clariant) was added, and 150 parts by weight using a hot-air dryer. After drying with hot air at 3 ° C. for 3 hours, the mixture was supplied to a FANUC α30C injection molding machine manufactured by FANUC CORPORATION. The resin temperature was set to the melting point of the liquid crystal polyester + 20 ° C., the mold temperature was set to 90 ° C. A 1 mm thick square plate-like molded product was continuously molded. While visually checking the state of adhesion of the mold deposit every 100 shots, a maximum of 1000 shots were continuously formed until the adhesion of the mold deposit was confirmed. The number of shots at which adhesion to the mold cavity was confirmed was regarded as mold contamination. The larger the number of shots in which the mold deposit has been confirmed to adhere to the mold cavity, the smaller the mold contamination, and the better the mold contamination. When adhesion of mold deposit was not confirmed even after continuous molding of 1000 shots, ">1000" was set.

(6) Dimensional stability For the molded product molded under the same conditions as in (4) and completely filled, the warpage amount of the connector molded product after the heat treatment was measured. The heat treatment was performed by leaving the connector molded product in an oven heated to 260 ° C. for 3 minutes. In addition, the amount of warpage was measured by using a universal projector (V-16A (manufactured by Nikon)) in a state where the longitudinal direction of the molded product was left standing on a horizontal surface plate. Based on a line connecting both ends with a straight line, a dimensional difference from the line to a horizontal surface plate was measured and defined as a warpage amount. FIG. 1B is a conceptual diagram showing a portion where the warpage amount is measured in the long molded product. The difference between the AB surface as a reference surface a and the maximum deformation surface b is defined as the warpage amount. The smaller the amount of warpage, the better the dimensional stability.

[Example 1]
9L parts by weight of p-hydroxybenzoic acid, 283 parts by weight of 4,4'-dihydroxybiphenyl, 99 parts by weight of hydroquinone, 284 parts by weight of terephthalic acid, 90 parts by weight of isophthalic acid were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. , 1,4-cyclohexanedimethanol and 1242 parts by weight of acetic anhydride (1.05 equivalents of the total of phenolic hydroxyl groups), and reacted at 145 ° C. for 1 hour while stirring under a nitrogen gas atmosphere. The vessel jacket temperature was raised from 145 ° C to 350 ° C over 4 hours. Thereafter, the polymerization temperature was maintained at 350 ° C., and after reducing the pressure to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued. When the torque required for stirring reached 8 kg · cm, the polymerization was completed. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-1) was obtained. The Tm of the obtained liquid crystal polyester resin was 327 ° C., and the melt viscosity was 9 Pa · s.

[Example 2]
870 parts by weight of p-hydroxybenzoic acid, 338 parts by weight of 4,4'-dihydroxybiphenyl, 119 parts by weight of hydroquinone, 247 parts by weight of terephthalic acid, 202 parts by weight of isophthalic acid in a 5 L reaction vessel equipped with a stirring blade and a distillation tube , 1,4-cyclohexanedimethanol and 1321 parts by weight of acetic anhydride (1.07 equivalents of phenolic hydroxyl group in total), and reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. The vessel jacket temperature was raised from 145 ° C to 330 ° C over 4 hours. Thereafter, the polymerization temperature was maintained at 330 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 10 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-2) was obtained. The Tm of the obtained liquid crystal polyester resin was 308 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 1]
9L parts by weight of p-hydroxybenzoic acid, 283 parts by weight of 4,4'-dihydroxybiphenyl, 99 parts by weight of hydroquinone, 284 parts by weight of terephthalic acid, 90 parts by weight of isophthalic acid were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. And 1242 parts by weight of acetic anhydride (1.05 equivalents of phenolic hydroxyl groups in total), and reacted at 145 ° C. for 1 hour while stirring under a nitrogen gas atmosphere, and then the jacket temperature of the reaction vessel was increased from 145 ° C. to 350 ° C. Was heated for 4 hours. Thereafter, the polymerization temperature was maintained at 350 ° C., and after reducing the pressure to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued. When the torque required for stirring reached 8 kg · cm, the polymerization was completed. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-3) was obtained. The Tm of the obtained liquid crystal polyester resin was 328 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 2]
870 parts by weight of p-hydroxybenzoic acid, 338 parts by weight of 4,4'-dihydroxybiphenyl, 119 parts by weight of hydroquinone, 247 parts by weight of terephthalic acid, 202 parts by weight of isophthalic acid in a 5 L reaction vessel equipped with a stirring blade and a distillation tube And 1302 parts by weight of acetic anhydride (1.07 equivalents of the total of phenolic hydroxyl groups), and the mixture was reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. Then, the jacket temperature of the reaction vessel was increased from 145 ° C. to 330 ° C. The temperature was raised over 4 hours. Thereafter, the polymerization temperature was maintained at 330 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 10 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-4) was obtained. The Tm of the obtained liquid crystal polyester resin was 310 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 3]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4,4'-dihydroxybiphenyl, 112 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0.6 dl / g. 216 parts by weight of polyethylene terephthalate and 960 parts by weight of acetic anhydride (1.10 equivalents of phenolic hydroxyl groups in total) were charged and reacted at 145 ° C. for 1 hour while stirring under a nitrogen gas atmosphere. The temperature was raised over time. Thereafter, the polymerization temperature was maintained at 320 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 15 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-5) was obtained. The Tm of the obtained liquid crystal polyester resin was 312 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 4]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 808 parts by weight of p-hydroxybenzoic acid, 503 parts by weight of 4,4'-dihydroxybiphenyl, 374 parts by weight of terephthalic acid, 75 parts by weight of isophthalic acid, and 6-hydroxy- 85 parts by weight of 2-naphthoic acid and 1254 parts by weight of acetic anhydride (1.05 equivalents of the total of phenolic hydroxyl groups) were charged and reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. Was raised from 145 ° C. to 360 ° C. over 4 hours. Thereafter, the polymerization temperature was maintained at 360 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 10 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-6) was obtained. The Tm of the obtained liquid crystal polyester resin was 350 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 5]
497 parts by weight of p-hydroxybenzoic acid, 285 parts by weight of 4,4'-dihydroxybiphenyl, 228 parts by weight of hydroquinone, 598 parts by weight of terephthalic acid, 6-hydroxy-2 in a 5 L reaction vessel equipped with a stirring blade and a distilling tube. -85 parts by weight of naphthoic acid and 1206 parts by weight of acetic anhydride (1.05 equivalents of phenolic hydroxyl groups in total) were charged and reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. The temperature was raised from 145 ° C to 350 ° C over 4 hours. Thereafter, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 10 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-7) was obtained. The Tm of the obtained liquid crystal polyester resin was 333 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 6]
932 parts by weight of p-hydroxybenzoic acid, 419 parts by weight of 4,4'-dihydroxybiphenyl, 254 parts by weight of terephthalic acid, 120 parts by weight of isophthalic acid and 1206 parts by weight of acetic anhydride were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. (1.05 equivalents of the total of phenolic hydroxyl groups), and the mixture was reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. Then, the jacket temperature of the reaction vessel was increased from 145 ° C. to 340 ° C. over 4 hours. The temperature rose. Thereafter, the polymerization temperature was maintained at 340 ° C., and after reducing the pressure to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued. When the torque required for stirring reached 10 kg · cm, the polymerization was completed. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-8) was obtained. The Tm of the obtained liquid crystal polyester resin was 328 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 7]
31 parts by weight of p-hydroxybenzoic acid, 524 parts by weight of 4,4'-dihydroxybiphenyl, 467 parts by weight of terephthalic acid, 1016 parts by weight of 6-hydroxy-2-naphthoic acid were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. And 1206 parts by weight of acetic anhydride (1.05 equivalents of the total of phenolic hydroxyl groups) were charged and reacted at 145 ° C. for 1 hour while stirring under a nitrogen gas atmosphere, and then the jacket temperature of the reaction vessel was raised from 145 ° C. to 360 ° C. To 4 hours. Thereafter, the polymerization temperature was maintained at 360 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was continued, and the polymerization was completed when the torque required for stirring reached 10 kg · cm. Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-9) was obtained. The Tm of the obtained liquid crystal polyester resin was 350 ° C., and the melt viscosity was 9 Pa · s.

[Comparative Example 8]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 994 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4,4'-dihydroxybiphenyl, 112 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0.6 dl / g. 216 parts by weight of polyethylene terephthalate, 3 parts by weight of 1,4-cyclohexanedimethanol and 963 parts by weight of acetic anhydride (1.10 equivalents of the total of phenolic hydroxyl groups) were charged and reacted at 145 ° C. for 1 hour while stirring under a nitrogen gas atmosphere. After that, the temperature was raised from 145 ° C to 320 ° C over 4 hours. Thereafter, the polymerization temperature was maintained at 320 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 15 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), and the polymer was discharged into a strand through a die having one circular discharge port with a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-10) was obtained. The obtained liquid crystal polyester resin had a Tm of 311 ° C. and a melt viscosity of 9 Pa · s.

  For the pellets obtained in Examples 1 and 2 and Comparative Examples 1 to 8, the results of the composition analysis by the method described in (1) above and the results of the evaluations of (4) to (6) are shown in Table. It is shown in FIG.

  Subsequently, the additives (a-1) to (a'-5) are further melt-kneaded with the liquid crystal polyester resins (A-3) to (A-9) obtained above to obtain a liquid crystal polyester resin. Produced.

The compounds used in each of the examples and comparative examples are shown below.
(A-1): 1,4-cyclohexanediol (molecular weight: 116) manufactured by Tokyo Chemical Industry Co., Ltd.
(A-2): 1,4-cyclohexanedimethanol (molecular weight: 144) manufactured by Tokyo Chemical Industry Co., Ltd.
(A-3): cyclohexane-1,4-diylbis (methylene) bis (4-hydroxybenzoate) (molecular weight: 384) synthesized according to Production Example 1 below (the two hydroxyl groups of 1,4-cyclohexanedimethanol) And a carboxyl group of p-hydroxybenzoic acid in an ester bond)
(A'-4): 4,4'-dihydroxybiphenyl (molecular weight: 186) manufactured by Tokyo Chemical Industry Co., Ltd.
(A'-5): 1,4-cyclohexanedicarboxylic acid (molecular weight: 172) manufactured by Tokyo Chemical Industry Co., Ltd.

The production example of (a-3) will be described below.
[Production Example 1]
75 parts by weight of p-hydroxybenzoic acid, 43 parts by weight of 1,4-cyclohexanedimethanol and 4 drops of concentrated sulfuric acid are put into toluene, and water generated by the reaction is distilled off azeotropically from the system while toluene alone is removed. Reflux and heat for 3 hours. After cooling to room temperature, methanol was added and the resulting solution was filtered. Furthermore, it wash | cleaned and dried several times with methanol, and set it as (a-3).

Examples 3 to 12, Comparative Examples 9 to 12
Using a TEM35B twin-screw extruder manufactured by Toshiba Machine Co., equipped with a side feeder, a side feeder is installed at C3 of cylinders C1 (heater on the feeder side) to C6 (die heater), and a vacuum vent is provided at C5. Was installed. A screw arrangement in which the kneading block was incorporated in the C2 part and the C4 part was used. The liquid crystal polyester resins (A-3) to (A-9) and the additives (a-1) to (a'-5) were charged in the amounts shown in Table 2 from the main feeder, and the cylinder temperature was changed to the liquid crystal polyester. The melting point of the resin was set to + 10 ° C., the screw rotation speed was set to 200 rpm, and the mixture was melt-kneaded to obtain pellets. After the obtained liquid crystal polyester resin pellets were dried with hot air at 150 ° C. for 3 hours using a hot air dryer, the above (1) and (4) to (6) were evaluated. The results are shown in Table 2.

Subsequently, an inorganic filler was added to the liquid crystal polyester resins (A-1) to (A-10) obtained as described above to prepare a liquid crystal polyester resin. The inorganic fillers (b-1) to (b-3) used in each example and comparative example are shown below.
(B-1): Mica "NJ-030" manufactured by Yamaguchi Mica Co., Ltd.
(B-2): Talc “RL217” manufactured by Fuji Talc Kogyo Co., Ltd.
(B-3): EPG (70MD-01N) / P9W manufactured by NEC Corporation.

Examples 13 and 14, Comparative Examples 13 to 20
The liquid crystal polyester resins (A-1) to (A-10) were charged at the compounding amounts shown in Table 3 from the feedstock feeder, and the inorganic fillers (b-1) to (b-3) were compounded as shown in Table 3. , And melted and kneaded in the same manner as in Examples 3 to 12 and Comparative Examples 9 to 12 to obtain pellets, and the above evaluations (4) to (6) were performed. The results are shown in Table 3.

Examples 15 to 25, Comparative Examples 21 to 24
Except that the inorganic fillers (b-1) to (b-3) were added from the side feeder in the amounts shown in Table 4, the pellets were melt-kneaded in the same manner as in Examples 3 to 12 and Comparative Examples 9 to 12. Then, the evaluations (1) and (4) to (6) were performed. The results are shown in Table 4.

  From the results of Tables 1 to 4, it is understood that the liquid crystal polyester resin and the liquid crystal polyester resin composition of the present invention are excellent in thin-wall fluidity and dimensional stability while suppressing mold contamination. Therefore, it can be said that it is suitable for use in electrical and electronic parts and mechanical parts such as connectors, relays, switches, coil bobbins, lamp sockets, camera modules, and integrated circuit sealing materials having a thin box or cylindrical shape. .

  The liquid crystal polyester resin and the liquid crystal polyester resin composition of the present invention are excellent in thin-wall fluidity and dimensional stability while suppressing mold contamination, so that connectors, relays, switches, and coil bobbins having a thin-walled box or cylindrical shape are provided. It is suitable for electric / electronic parts and mechanical parts such as lamp sockets, camera modules, and sealing materials for integrated circuits.

1 long surface 2 short surface 3 length (30mm)
4 height (2mm)
5 width (3mm)
6 Distance between pitches (0.4mm)
7 Minimum thickness (0.2mm)
8 Sliding amount G1 Pin gate a Reference surface b Maximum deformation surface

Claims (8)

15 to 80 mol% of a structural unit derived from an aromatic hydroxycarboxylic acid, 7 to 40 mol% of a structural unit derived from an aromatic diol, and aromatic dicarboxylic acid with respect to 100 mol% of all the structural units of the liquid crystal polyester resin. A liquid crystal polyester resin comprising 7 to 40 mol% of a structural unit derived from, and 0.01 to 5 mol% of at least one structural unit selected from the following structural units (I) and (II).

The liquid crystal polyester resin contains the following structural unit (III) as a structural unit derived from an aromatic hydroxycarboxylic acid, and contains the following structural unit (IV) as a structural unit derived from an aromatic dicarboxylic acid; The liquid crystal polyester resin according to claim 1, wherein the total of the structural units (IV) and (IV) is 60 to 80 mol% based on 100 mol% of all the structural units of the liquid crystal polyester resin.

The liquid crystal polyester resin contains the following structural unit (V) as a structural unit derived from an aromatic diol, and the structural unit (V) is 2 to 20% based on 100 mol% of all the structural units of the liquid crystal polyester resin. The liquid crystal polyester resin according to claim 1.

The liquid crystal polyester resin according to any one of claims 1 to 3, wherein at least one structural unit selected from the structural units (I) and (II) includes the structural unit (II) as an essential component. By melt-kneading a liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II) and a compound having at least one type of structure selected from the structural units (I) and (II). A method for producing a liquid crystal polyester resin, which obtains the liquid crystal polyester resin according to claim 1. A liquid crystal polyester resin composition comprising 10 to 200 parts by weight of a filler with respect to 100 parts by weight of the liquid crystal 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 6 . The molded article according to claim 7 , wherein the molded article is selected from the group consisting of a connector, a relay, a switch, a coil bobbin, a lamp socket, a camera module, and an integrated circuit encapsulant.

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