JPWO2019198665A1 - Liquid crystal polyester resin, method for producing the same, and molded article made of the same - Google Patents

Abstract

SOLUTION: The structural unit derived from an aromatic hydroxycarboxylic acid is 15 to 80 mol%, the structural unit derived from an aromatic diol is 7 to 40 mol%, based on 100 mol% of all the structural units of the 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 are a liquid crystal polyester resin excellent in thin-wall fluidity and dimensional stability while suppressing mold fouling, and a molded article made of the same. [Chemical 1]

Description

  The present invention relates to a liquid crystal polyester resin and a molded article made of the same. More specifically, the present invention relates to a liquid crystal polyester resin capable of obtaining a molded product excellent in fluidity and dimensional stability while suppressing mold fouling during molding, and a molded product made of the same.

  Since the liquid crystal polyester resin has a liquid crystal structure, it has excellent heat resistance, fluidity and dimensional stability. For this reason, demand is expanding mainly for electrical and electronic component applications such as connectors and relays that require those characteristics. In particular, as the performance of equipment has been improved in recent years, the parts are becoming smaller and thinner, and further fluidity is required. Therefore, for example, it has been proposed to improve the fluidity by melt-kneading a low molecular weight compound with a liquid crystal polymer to obtain a liquid crystal polymer having a low melt viscosity (see, for example, 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 of fluidity by a liquid crystal polyesteramide containing a structure derived from acetaminophenone or 1,4-cyclohexanedicarboxylic acid has been proposed (for example, Patent Document 1). 3).

Japanese Patent Publication No. 2002-511513 JP, 2018-44108, A International Publication No. 2013/115168

  On the other hand, when the liquid crystal polyester resin is made to have a low melt viscosity by the method described in Patent Documents 1 and 2, since the low molecular weight compound used itself has low heat resistance, high processing required for molding the liquid crystal polyester resin is required. At the temperature, there is a problem that the gas decomposes and the amount of gas increases, the mold becomes dirty at the time of molding, and the dimensional stability decreases. Moreover, the thin-wall fluidity was also insufficient. Further, the liquid crystal polyesteramide resin described in Patent Document 3 also has problems in mold fouling and dimensional stability, and has insufficient thin-wall fluidity.

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

  The present inventors have conducted extensive studies to solve the above problems, and as a result, a liquid crystal polyester resin containing a small amount of a specific structural unit suppresses mold fouling at the time of molding, while maintaining fluidity and dimensional stability. The present invention has been accomplished by finding that it is possible to obtain an excellent molded product.

The invention is:
(1) 15-80 mol% of a structural unit derived from an aromatic hydroxycarboxylic acid, 7-40 mol% of a structural unit derived from an aromatic diol, and an aromatic compound based on 100 mol% of all the structural units of the liquid crystal polyester resin. A liquid crystal polyester resin containing 7 to 40% of a structural unit derived from a group dicarboxylic acid and 0.01 to 5 mol% 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 the following structural unit (IV) as a structural unit derived from an aromatic dicarboxylic acid, and a structural unit The liquid crystal polyester resin according to (1), wherein the total 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 with respect to 100 mol% of all the structural units of the liquid crystal polyester resin. %, 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 resin containing no structural unit selected from the structural units (I) and (II), and a compound having at least one structure selected from the structural units (I) and (II) are blended. The liquid crystal polyester resin according to any one of (1) to (4) obtained by the above.
(6) Melt kneading a liquid crystal polyester containing no structural unit selected from the structural units (I) and (II) and a compound having at least one structure selected from the structural units (I) and (II). The method for producing a liquid crystal polyester resin according to any one of (1) to (5).
(7) A liquid crystal polyester resin composition containing 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 (5).
(8) A molded product comprising the liquid crystal polyester resin according to any one of (1) to (5) or the liquid crystal polyester resin composition according to (7).
(9) The molded product according to (8), wherein the molded product 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.

  According to the liquid crystal polyester resin of the present invention, it is possible to obtain a molded article having excellent fluidity and dimensional stability while suppressing mold stains during molding. Such a resin is particularly suitable for electrical / electronic parts and mechanical parts such as thin-walled box-shaped or tubular connectors, relays, switches, coil bobbins, lamp sockets, camera modules, and integrated circuit sealing materials.

3A and 3B are a perspective view of a connector molded product manufactured in an example and a conceptual diagram showing a portion for measuring 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 polyesters composed of structural units selected from an oxycarbonyl unit, a dioxy unit, a dicarbonyl unit, etc., which will be described later, 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 an oxycarbonyl unit, that is, a structural unit derived from an aromatic hydroxycarboxylic acid, based on 100 mol% of all the structural units of the liquid crystal polyester resin. When the content of the oxycarbonyl unit is less than 15 mol%, the liquid crystallinity is impaired, the fluidity of the liquid crystal polyester resin is lowered, and the dimensional stability is also lowered. From the viewpoint of improving fluidity and dimensional stability, the content of oxycarbonyl units is preferably 20 mol% or more, and more preferably 25 mol% or more. On the other hand, when the content of the oxycarbonyl unit is more than 80 mol%, it becomes difficult to control the crystallinity and the melting point of the liquid crystal polyester resin, and the fluidity and the dimensional stability deteriorate. From the viewpoint of improving fluidity and dimensional stability, the content of oxycarbonyl units is preferably 75 mol% or less, more preferably 70 mol% or less.

  As a specific example of the oxycarbonyl unit, a structural unit derived from p-hydroxybenzoic acid, m-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, or the like can be used.

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

  Further, the liquid crystal polyester resin of the present invention contains, 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 above content. , 0.01 to 5 mol% based on 100 mol% of all structural units of the liquid crystal polyester resin. 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 0.03 mol% or more, more preferably 0.05 mol% or more. On the other hand, when the content of these structural units is more than 5 mol%, the mold is contaminated during molding, and the thin-wall fluidity and the dimensional stability are deteriorated. The content of these structural units is preferably 3% or less, more preferably 1% or less, from the viewpoint of excellent thin-wall fluidity and dimensional stability while suppressing mold fouling during molding. 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%, but it suppresses mold stains during molding. However, from the viewpoint of excellent thin-wall fluidity and dimensional stability, it is preferable to include the structural unit (II) as an essential component.

  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'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 4,4 Structural units derived from'-dihydroxybenzophenone and the like can be mentioned. 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 fouling during molding. Further, a structural unit derived from an aliphatic diol such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol is further contained in a range not impairing liquid crystallinity and characteristics. 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 an 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 becomes difficult to control the crystallinity and melting point of the liquid crystal polyester resin, and the fluidity and the dimensional stability deteriorate. 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, 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, the fluidity of the liquid crystal polyester resin is lowered, and the dimensional stability is also lowered. From the viewpoint of improving 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, 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 can be mentioned. 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 fouling during molding. Further, structural units derived from aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and hexahydroterephthalic acid, alicyclic rings such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid A structural unit derived from the formula dicarboxylic acid may be further contained in a range not impairing liquid crystallinity and characteristics.

  Further, in addition to the above structural unit, a structural unit formed from p-aminobenzoic acid, p-aminophenol, or the like can be further included within a range not impairing liquid crystallinity and characteristics.

  The raw material monomer constituting each structural unit is not particularly limited as long as it has a structure capable of forming each structural unit, but is an acylated product of a hydroxyl group of each structural unit, an esterified product of a carboxyl group of each structural unit, an acid halogen. Compounds, carboxylic acid derivatives such as acid anhydrides and the like 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 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 unit (III) and the structural unit (IV) is preferably 63 mol% or more, from the viewpoint of excellent thin-wall fluidity and dimensional stability. More preferably, it is 67 mol% or more. On the other hand, after controlling the crystallinity and melting point of the liquid crystal polyester resin, the total content of the structural unit (III) and the structural unit (IV) is preferably 78 mol from the viewpoint of excellent thin-wall fluidity and dimensional stability. % Or less. Further, 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%, but the crystallinity and the melting point of the liquid crystal polyester resin may be From the viewpoint of control, it is preferable that both are contained in an amount of more than 0 mol%.

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

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

  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 structural units of the liquid crystal polyester resin. % Is preferably contained. 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 4 mol% or more, still more preferably 7.5 mol% or more. 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, 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 structural units of the liquid crystal polyester resin. It is preferable to contain it by mol%. The structural unit (VI) is a structural unit derived from 4,4'-dihydroxybiphenyl. By containing the structural unit (VI) in an amount of 3 mol% or more, the crystallinity and melting point of the liquid crystal polyester resin can be controlled, and heat resistance is improved. The content of the structural unit (VI) is preferably 5 mol% or more, more preferably 7 mol% or more. 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 is improved. The content of the structural unit (VI) is more preferably 25 mol% or less, further 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% based on the total amount of structural units 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 is improved. The content of the structural unit (VII) is preferably 2 mol% or more, more preferably 3 mol% or more. On the other hand, when the content of the structural unit (VII) is 10 mol% or less, the crystallinity and melting point of the liquid crystal polyester resin can be controlled, and the heat resistance is improved. The content of the structural unit (VII) is more preferably 9 mol% or less, further 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 the liquid crystal polyester pellets, adding tetramethylammonium hydroxide, and performing pyrolysis GC / MS measurement using Shimadzu GCMS-QP5050A. be able to. The content of structural units that were not detected or were below the detection limit was calculated as 0 mol%.

  From the viewpoint of heat resistance, 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. 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 350 from the viewpoint of suppressing deterioration of the liquid crystal polyester resin during processing and suppressing mold fouling during molding. C. or less is more preferable.

The melting point (Tm) is measured by differential scanning calorimetry. Specifically, first, the endothermic peak temperature (Tm ₁ ) is observed by heating the polymer that has completed the polymerization from room temperature under a temperature rising 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 ℃. Then, the polymer is cooled to room temperature under a temperature lowering condition of 20 ° C./min. Then, the endothermic peak temperature (Tm ₂ ) is observed by heating the polymer again under the temperature rising 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, and further 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, more preferably 20 Pa · s or less, and further 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.

<Method for producing liquid crystal polyester resin>
The method for producing the liquid crystal polyester resin used in the present invention includes the following methods.
(A) A method of adding a compound having at least one structure selected from the structural unit (I) and the structural unit (II) during the production according to the known polycondensation method of polyester described below.
(B) A liquid crystal polyester resin containing no structural unit selected from 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 incorporating a compound having at least one structure selected from II).

  By appropriately transesterifying with the liquid crystal polyester resin, it is possible to further improve thin-wall fluidity and dimensional stability while suppressing mold fouling at the time of molding. Therefore, (B) structural units (I) and (II) A method is preferred in which a liquid crystal polyester resin containing no structural unit selected from (1) is produced and then a compound having at least one structure selected from structural unit (I) and structural unit (II) is added. As a method of blending these, a method of melt-kneading these is preferable. The detailed manufacturing method will be described later.

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

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

  These compounds are 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, the method described in Japanese Patent Publication No. 2008-544954. Can be used for esterification. Specifically, 1,4-cyclohexanediol or 1,4-cyclohexanedimethanol and an aromatic hydroxycarboxylic acid are reacted by heating under reflux in a solvent in the presence of sulfuric acid, and then purified by washing with methanol. By doing so, it is possible to obtain a compound in which one or more oxycarbonyl units capable of forming a liquid crystal polyester resin are ester-bonded to the diol compound.

  The molecular weight of the compound having at least one structure selected from the structural unit (I) and the structural unit (II) is 200 in terms of excellent thin-wall fluidity and dimensional stability while suppressing mold fouling during molding. The above is preferable, 230 or more is more preferable, and 250 or more is further preferable. On the other hand, in the case where 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 1,000 or less from the viewpoint of suppressing infusate formation due to long chains of rigid structural units. It is preferably 700 or less, more preferably 500 or less.

  When the liquid crystal polyester resin is produced by the method (B), in order to set the content of at least one selected from the structural unit (I) and the structural unit (II) within a desired range, the structural unit (I) and A compound having at least one structure selected from structural unit (I) and structural unit (II) is preferably added to 0.01 part by weight with respect to 100 parts by weight of a liquid crystal polyester resin containing no structural unit selected from (II). It is preferable that the amount is at least parts by weight, more preferably at least 0.03 parts by weight, further preferably at least 0.05 parts by weight. On the other hand, with respect to 100 parts by weight of the liquid crystal polyester resin containing no structural unit selected from structural units (I) and (II), at least one structure selected from structural unit (I) and structural unit (II) is added. It is preferable that the compound has 10 parts by weight or less, more preferably 7 parts by weight or less, further preferably 3 parts by weight or less.

  As a known polycondensation method for polyesters, 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 Examples of the liquid crystal polyester resin composed of a structural unit derived from isophthalic acid include the following.

  (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 deacetic acid condensation polymerization reaction.

  (2) Liquid crystal polyester obtained by reacting p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, and isophthalic acid with acetic anhydride to acetylate a phenolic hydroxyl group and then deacetic acid-polymerize. A method for producing 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 dephenol polycondensation reaction.

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

  Among them, (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. The method for producing a liquid crystal polyester resin is industrially excellent in controlling the terminal structure of the liquid crystal polyester resin and controlling the degree of polymerization, and is preferably used.

  As a method for producing a liquid crystal polyester resin, it is also possible to complete the polycondensation reaction by a solid phase polymerization method. Examples of the solid-phase polymerization method include the following methods. First, a polymer or oligomer of 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 polycondense to a desired degree of polymerization. The above-mentioned heating can be performed within the range of the melting point of liquid crystal polyester −50 ° C. to melting point −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, metallic 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, but examples thereof include fibrous filler, whisker-like filler, plate-like filler, powder filler, and granular filler. Specifically, as the fibrous filler and the whisker-like filler, glass fiber; PAN-based or pitch-based carbon fiber; metal fiber such as stainless fiber, aluminum fiber or brass fiber; aromatic polyamide fiber or liquid crystal polyester fiber Organic fibers such as; gypsum fiber, ceramic fiber, asbestos fiber, zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whiskers, barium titanate whiskers, aluminum borate whiskers, nitriding Silicon whiskers, acicular titanium oxide and the like can be mentioned. Examples of the plate-shaped filler include mica, talc, kaolin, glass flake, clay, molybdenum disulfide, and wollastonite. Examples of the powdery filler and the granular filler include silica, glass beads, titanium oxide, zinc oxide, calcium polyphosphate and graphite. The surface of the above-mentioned filler may be treated with a known coupling agent (for example, a silane coupling agent, a titanate coupling agent, etc.) or another surface treatment agent. Two or more fillers may be used in combination.

  Among the above-mentioned fillers, glass fiber is preferable because it is 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. Further, from the viewpoint of excellent thin-wall fluidity, it is preferable to use mica.

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

  The content of the filler is preferably 10 to 200 parts by weight with respect to 100 parts by weight of the liquid crystal polyester resin. When the content of the filler is 10 parts by weight or more, the mechanical strength of the molded product can be improved, which is preferable. 15 parts by weight or more is more preferable, and 20 parts by weight or more is further preferable. 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. The amount is preferably 150 parts by weight or less, more preferably 100 parts by weight or less.

  The liquid crystal polyester resin composition of the present invention further includes an antioxidant, a heat stabilizer (for example, hindered phenol, hydroquinone, phosphite, thioethers and substituted products thereof, etc.) within a range that does not impair the effects of the present invention, UV absorbers (eg, resorcinol, salicylate), phosphite, hypophosphite and other anti-coloring agents, lubricants and mold release agents (montanic acid and its metal salts, its esters, its half esters, stearyl alcohol, Stearamide and polyethylene wax, etc.), colorants containing dyes or pigments, carbon black as a conductive agent or colorant, crystal nucleating agent, plasticizer, flame retardant (bromine flame retardant, phosphorus flame retardant, red phosphorus, silicone flame retardant) (Combustible agents, etc.), flame retardant aids, and ordinary additives selected from antistatic agents. It can be.

<Method for producing 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 structural units (I) and (II) A dry blending method in which a compound having at least one structure selected, a filler, and other solid additives are blended, and a liquid crystal polyester resin containing no structural unit selected from structural units (I) and (II) , A solution blending method of blending a compound having at least one structure selected from structural units (I) and structural units (II), fillers and other liquid additives, structural units (I) and structural units A compound having at least one structure selected from (II), a filler and other additives are selected from structural units (I) and (II). Method of addition at the time of polymerization of liquid crystal polyester resin containing no structural unit, liquid crystal polyester resin containing no structural unit selected from structural units (I) and (II), selected from structural unit (I) and structural unit (II) It is possible to use a method of melt-kneading the compound having at least one kind of structure, the filler and the other additives mentioned above. Among them, the method of melt-kneading is preferable. A known method can be used for the melt kneading. For example, a Banbury mixer, a rubber roll machine, a kneader, a single-screw or twin-screw extruder, etc. are used to melt-knead the above components at a melting point of the liquid crystal polyester resin + 50 ° C. or less to obtain a liquid crystal polyester resin composition. .. Of these, melt-kneading using a twin-screw extruder is preferable.

  In order to improve the dispersibility of the liquid crystal polyester resin and the filler, the twin-screw extruder is preferably provided with one or more kneading parts, more preferably two or more kneading parts. When the liquid crystal polyester resin is produced by the above-mentioned method (B), the kneading part is provided as described above so that the liquid crystal polyester resin does not contain a structural unit selected from structural units (I) and (II), The dispersibility of the compound having at least one kind of structure selected from the structural unit (I) and the structural unit (II) is improved, and the two undergo an appropriate transesterification reaction, thereby suppressing mold stains during molding. It is possible to further improve thin-wall fluidity and dimensional stability. The kneading part may be installed, for example, when the filler is added from the side feeder, in order to accelerate the plasticization of the liquid crystal polyester resin, at least one place upstream of the side feeder of the filler is filled with the liquid crystal polyester resin. In order to improve the dispersibility with the material, it is preferable to install one or more places on the downstream side of the side feeder, that is, two or more places in total.

  Further, in order to remove water in the twin-screw extruder and decomposed products generated during kneading, it is preferable to provide a vent portion. For example, when a filler is added from the side feeder, the vent portion is installed at one or more locations upstream of the side feeder into which the filler is added in order to remove water adhering to the liquid crystal polyester resin. In order to remove the decomposed gas and the carry-in air at the time of supplying the filler, it is preferable to install one or more places downstream of the side feeder, that is, two or more places in total. The vent portion 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 structural units (I) and (II), and at least one structure selected from structural unit (I) and structural unit (II). A method in which a compound, a filler and other additives are initially charged from a feeder and kneaded all at once (collective 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 kind of structure selected from structural units (I) and structural units (II), and other additives are charged into a feeder, kneaded and kneaded, and then a filler and other additives are added to the side. Method of adding from a feeder and kneading (side feed method), (3) Liquid crystal containing no structural unit selected from structural units (I) and (II) A master pellet containing a reester resin, a compound having at least one structure selected from structural units (I) and structural units (II), and other additives in a high concentration is prepared, and then a master pellet is prepared to have a predetermined concentration. Examples thereof include a method of kneading the master pellet with a liquid crystal polyester resin and a filler (master pellet method). It doesn't matter which method is used.

  The liquid crystal polyester resin composition of the present invention has an excellent surface appearance (color tone) and mechanical properties by performing known melt molding such as injection molding, injection compression molding, compression molding, extrusion molding, blow molding, press molding, and spinning. It is possible to process into a molded article having specific properties, heat resistance and flame retardancy. Examples of the molded product here include injection molded products, extrusion molded products, press molded products, sheets, pipes, various films such as unstretched films, uniaxially stretched films and biaxially stretched films, unstretched yarns, super-stretched yarns and the like. Examples include various fibers. 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 are, for example, various gears, various cases, sensors, LED lamps, connectors, sockets, resistors, relay cases, relay bases, spools for relays. , Switch, coil bobbin, camera module, condenser, variable capacitor case, optical pickup, oscillator, various terminal boards, transformer, plug, printed wiring board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, Electric / electronic parts typified by housings, semiconductors, integrated circuit sealing materials, 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 oven parts, audio parts, audio equipment parts such as audio / laser disks / compact disks; lighting parts, refrigerator parts, air conditioner parts, personal computer parts, etc. Household and office electrical product parts; representative of office computer related parts, telephone related parts, facsimile related parts, copier related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings and other bearings, motor parts, etc. Machine-related parts; microscopes, binoculars, cameras, clocks, and other optical instruments; precision machine-related parts; alternator terminals, alternator connectors, IC regulators, potentiometer bases for light dimmers, various valves such as exhaust gas valves, fuel-related parts Exhaust system 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 meters, brake butt wear sensors, air conditioner thermostat bases, air conditioner motor insulators, power window and other vehicle motor insulators, heating hot air flow control valves, radiator motor brush holders, water pump impellers, turbine vanes, wiper motors. Related parts, dust distributor, starter switch, starter relay, transmission Wiring harness, window washer nozzle, air conditioner panel switch board, fuel related solenoid valve coil, fuse connector, horn terminal, electrical component insulating plate, step motor rotor, lamp bezel, lamp socket, lamp reflector, lamp housing, Automobile / vehicle related parts such as brake piston, solenoid bobbin, engine oil filter, igniter case, etc .; various chemical bottles such as shampoo, rinse, liquid soap, detergent; tank for storing chemical liquid, tank for storing gas, coolant tank, Oil transfer tanks, antiseptic tanks, blood transfusion pump tanks, fuel tanks, canisters, washer fluid tanks, oil reservoir tanks and other chemical / gas storage tanks; medical device parts; soy sauce, sauces, ketchup, mayo Seasonings such as drinks, dressings, fermented foods such as miso and vinegar, fats and oils foods such as salad oil, sake, beer, mirin, whiskey, liquors such as shochu, wine, carbonated drinks, juices, sports drinks, milk, coffee drinks , A food storage container for soft drinks such as oolong tea, black tea, and mineral water; and a tank as a general household appliance component, a bottle-shaped molded product, or a hollow container such as the tank.

  Among them, it is a thin-walled connector, relay, switch, coil bobbin that has a metal terminal part and has a thin box-shaped or tubular shape because it suppresses mold fouling during molding and has excellent thin-wall fluidity and dimensional stability. It is particularly useful for electric / electronic parts such as lamp sockets, lamp modules, camera modules, and integrated circuit encapsulants.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the examples. In the examples, the composition and characteristics 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 pulverized liquid crystal polyester resin pellets, 2 μL of 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 constituent in the liquid crystal polyester resin was determined.

(2) Melting point (Tm) of liquid crystal polyester resin
Using a differential scanning calorimeter DSC-7 (manufactured by Perkin Elmer), after observing the endothermic peak temperature (Tm ₁ ) observed when the liquid crystal polyester resin was heated from room temperature under a temperature rising condition of 20 ° C./min. , Tm ₁ + 20 ° C. for 5 minutes, further cooled to room temperature under a temperature lowering condition of 20 ° C./min, and then increased again under a temperature rising 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 Using a high-performance flow tester CFT-500D (orifice 0.5φ × 10 mm) (manufactured by Shimadzu Corporation), melting of the liquid crystal polyester resin under the conditions of Tm + 20 ° C. and shear rate of 1000 / s. The viscosity was measured.

(4) Thin-wall fluidity The pellets obtained in each Example and Comparative Example were hot-air dried at 150 ° C. for 3 hours using a hot-air dryer, and then subjected to FANUC α30C injection molding machine manufactured by FANUC CO., LTD. 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 terminal pitch shown in FIG. 3) was 0.2 mm, and the external dimensions were 3 mm in width × 2 mm in height × 30 mm in length to obtain a connector molded product. FIG. 1a is a perspective view of the connector molded product. A liquid crystal polyester resin or a resin composition was filled from the pin gate G1 (gate diameter 0.3 mm) installed on the short surface 2 on one side of the connector molded product. Molding was performed for 500 shots, and the number of unfilled occurrences was evaluated for the filling property of the wall corner portion on the gate facing side. 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 occurrences of unfilling, the better the thin-wall fluidity.

(5) Mold Contamination Property To 100 parts by weight of the pellets obtained in each Example and Comparative Example, 0.05 part by weight of a mold release agent (LicowaxE, manufactured by Clariant) was added, and 150 parts by hot air dryer was used. After being dried with hot air for 3 hours at 50 ° C., it is subjected to a FANUC α30C injection molding machine manufactured by FANUC CO., LTD., The resin temperature is the melting point of liquid crystalline polyester + 20 ° C., the mold temperature is 90 ° C., and the molding cycle is 12 seconds, 50 mm × 50 mm × A rectangular plate-shaped molded product having a thickness of 1 mm was continuously molded. While visually confirming the state of adhesion of the mold deposit for every 100 shots, continuous molding was performed for a maximum of 1000 shots until the adhesion of the mold deposit was confirmed. The number of shots when adhesion to the mold cavity was confirmed was defined as the mold stain property. The larger the number of shots in which the mold deposit is confirmed to be attached to the inside of the mold cavity, the less the mold stains are, and the better the mold stain resistance is. When adhesion of the mold deposit was not confirmed even after 1000 shots continuous molding, it was set to ">1000".

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

[Example 1]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 932 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. , 1,4-cyclohexanedimethanol (3 parts by weight) and acetic anhydride (1242 parts by weight) (1.05 equivalents of total phenolic hydroxyl groups) were charged and reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. The jacket temperature of the container was raised from 145 ° C to 350 ° C over 4 hours. Then, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 8 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-1) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 327 ° C. and a melt viscosity of 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 were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. , 1,4-cyclohexanedimethanol (3 parts by weight) and acetic anhydride (1321 parts by weight) (1.07 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 145 ° C. for 1 hour with stirring under a nitrogen gas atmosphere. The jacket temperature of the container was raised from 145 ° C to 330 ° C over 4 hours. Then, the polymerization temperature was maintained at 330 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-2) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 308 ° C. and a melt viscosity of 9 Pa · s.

[Comparative Example 1]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 932 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. And 1242 parts by weight of acetic anhydride (1.05 equivalents of total 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 changed from 145 ° C. to 350 ° C. Was heated over 4 hours. Then, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then the reaction was further continued, and the polymerization was completed when the torque required for stirring reached 8 kg · cm. . Next, the inside of the reaction vessel was pressurized to 1.0 kg / cm ² (0.1 MPa), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-3) was obtained. The obtained liquid crystal polyester resin had a Tm of 328 ° C. and a melt viscosity of 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 were placed 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 total phenolic hydroxyl groups) were charged and reacted for 1 hour at 145 ° C with stirring under a nitrogen gas atmosphere, and then the jacket temperature of the reaction vessel was changed from 145 ° C to 330 ° C. The temperature was raised over 4 hours. Then, the polymerization temperature was maintained at 330 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-4) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 310 ° C. and a melt viscosity of 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 total phenolic hydroxyl groups) were charged and reacted for 1 hour at 145 ° C. under stirring in a nitrogen gas atmosphere, then from 145 ° C. to 320 ° C. The temperature was raised over time. Then, the polymerization temperature was maintained at 320 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-5) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 312 ° C. and a melt viscosity of 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, 6-hydroxy- After charging 85 parts by weight of 2-naphthoic acid and 1254 parts by weight of acetic anhydride (1.05 equivalents of the total phenolic hydroxyl groups) and reacting at 145 ° C. for 1 hour under stirring under a nitrogen gas atmosphere, the jacket temperature of the reaction vessel The temperature was raised from 145 ° C to 360 ° C over 4 hours. Then, the polymerization temperature was maintained at 360 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-6) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 350 ° C. and a melt viscosity of 9 Pa · s.

[Comparative Example 5]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 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. -Preparing 85 parts by weight of naphthoic acid and 1206 parts by weight of acetic anhydride (1.05 equivalents of the total phenolic hydroxyl groups), reacting at 145 ° C for 1 hour while stirring under a nitrogen gas atmosphere, and then changing the jacket temperature of the reaction vessel. The temperature was raised from 145 ° C to 350 ° C over 4 hours. Then, the polymerization temperature was maintained at 350 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-7) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 333 ° C. and a melt viscosity of 9 Pa · s.

[Comparative Example 6]
In a 5 L reaction vessel equipped with a stirring blade and a distillation tube, 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 added. (1.05 equivalent of the total of phenolic hydroxyl groups) was charged and reacted for 1 hour at 145 ° C. under stirring in a nitrogen gas atmosphere, and then the jacket temperature of the reaction vessel was changed from 145 ° C. to 340 ° C. over 4 hours. The temperature was raised. Then, the polymerization temperature was maintained at 340 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-8) was obtained. The obtained liquid crystal polyester resin had a Tm of 328 ° C. and a melt viscosity of 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. Parts and 1206 parts by weight of acetic anhydride (1.05 equivalents of the total 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 changed from 145 ° C. to 360 ° C. Up 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 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-9) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 350 ° C. and a melt viscosity of 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. Charge 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 total phenolic hydroxyl groups), and react 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. Then, the polymerization temperature was maintained at 320 ° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and then 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), the polymer was discharged into a strand through a die having a circular discharge port having a diameter of 10 mm, and pelletized by a cutter. A liquid crystal polyester resin (A-10) was obtained. The liquid crystal polyester resin thus obtained had a Tm of 311 ° C. and a melt viscosity of 9 Pa · s.

  The results of composition analysis by the method described in (1) above and the results of evaluation of (4) to (6) are shown for the pellets obtained in Examples 1 and 2 and Comparative Examples 1 to 8. Shown in 1.

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

The compounds used in each Example and Comparative Example are shown below.
(A-1): 1,4-cyclohexanediol manufactured by Tokyo Chemical Industry Co., Ltd. (molecular weight: 116)
(A-2): Tokyo Chemical Industry Co., Ltd. 1,4-cyclohexanedimethanol (molecular weight: 144)
(A-3): Cyclohexane-1,4-diylbis (methylene) bis (4-hydroxybenzoate) (molecular weight: 384) synthesized according to Production Example 1 below (two hydroxyl groups of 1,4-cyclohexanedimethanol) And a compound in which the carboxyl group of p-hydroxybenzoic acid is ester-bonded)
(A'-4): 4,4'-dihydroxybiphenyl manufactured by Tokyo Chemical Industry Co., Ltd. (molecular weight: 186)
(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 were placed in toluene, and water generated by the reaction was distilled off to the outside of the system by azeotropic distillation. Reflux and heat for 3 hours. After cooling to room temperature, methanol was added and the resulting solution was filtered. Further, it was washed with methanol several times and dried to obtain (a-3).

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

Subsequently, the liquid crystal polyester resin (A-1) to (A-10) obtained above was mixed with an inorganic filler 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 Industry Co., Ltd.
(B-3): EPG (70MD-01N) / P9W manufactured by Nippon Electric Glass Co., Ltd.

Examples 13 and 14, Comparative Examples 13 to 20
Liquid crystal polyester resins (A-1) to (A-10) were added from the original loading feeder in the compounding amounts shown in Table 3, and the inorganic fillers (b-1) to (b-3) were compounded in the compounding amounts shown in Table 3. In the same manner as in Examples 3 to 12 and Comparative Examples 9 to 12 except that the mixture was charged from the side feeder, pellets were obtained by melt kneading, and the above (4) to (6) were evaluated. The results are shown in Table 3.

Examples 15-25, Comparative Examples 21-24
Pellets were prepared by melt-kneading in the same manner as in Examples 3 to 12 and Comparative Examples 9 to 12, except that the inorganic fillers (b-1) to (b-3) were added from the side feeder in the amounts shown in Table 4. Then, the above (1) and (4) to (6) were evaluated. The results are shown in Table 4.

  From the results of Tables 1 to 4, it can be seen 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 fouling. Therefore, it can be said that it is suitable for use in electrical / electronic parts and mechanical parts such as thin-walled box-shaped or cylindrical connectors, relays, switches, coil bobbins, lamp sockets, camera modules, and integrated circuit sealing materials. .

  Since the liquid crystal polyester resin and the liquid crystal polyester resin composition of the present invention have excellent thin-wall fluidity and dimensional stability while suppressing mold fouling, connectors, relays, switches, and coil bobbins having a thin-walled box shape or a tubular shape are provided. It is suitable for electrical / electronic parts such as lamp sockets, camera modules, and integrated circuit sealing materials, and mechanical parts.

1 Long surface 2 Short surface 3 Length (30mm)
4 height (2mm)
5 width (3 mm)
Distance between 6 pitches (0.4mm)
7 Minimum wall thickness (0.2 mm)
8 Deflection G1 Pin gate a Reference plane b Maximum deformation plane

(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 ) Melt-kneading a liquid crystal polyester containing no structural unit selected from the structural units (I) and (II) and a compound having at least one structure selected from the structural units (I) and (II). A method for producing a liquid crystal polyester resin, whereby the liquid crystal polyester resin according to any one of (1) to ( 4 ) is obtained .
( 6 ) A liquid crystal polyester resin composition containing 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 product according to ( 8 ), wherein the molded product 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.

Claims (9)

Aromatic hydroxycarboxylic acid-derived structural units are 15 to 80 mol%, aromatic diol-derived structural units are 7 to 40 mol%, and aromatic dicarboxylic acid based on 100 mol% of all structural units of the liquid crystal polyester resin. A liquid crystal polyester resin containing 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 the following structural unit (IV) as a structural unit derived from an aromatic dicarboxylic acid, and a structural unit (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.

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 claim 1, wherein at least one structural unit selected from the structural units (I) and (II) contains the structural unit (II) as an essential component. Obtained by blending a liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II) and a compound having at least one structure selected from the structural units (I) and (II). The liquid crystal polyester resin according to any one of claims 1 to 4. A liquid crystal polyester resin containing no structural unit selected from the structural units (I) and (II) and a compound having at least one structure selected from the structural units (I) and (II) are melt-kneaded. 5. A method for producing a liquid crystal polyester resin according to any one of 1 to 4. 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 claim 1. A molded article comprising the liquid crystal polyester resin according to claim 1 or the liquid crystal polyester resin composition according to claim 7. The molded product according to claim 8, wherein the molded product 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.

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