Liquid crystal resin

Abstract

To provide a liquid crystal resin which gives a film having a desired surface roughness and / or a desired hue when used as a film material, and to provide a method for producing the same.SOLUTION: A liquid crystal resin contains 90 mol% or more of structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof in all structural units, and has ester bonds or ester bonds and ketone bonds in the molecule, where the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 mmol%.

Description

[Technical Field]

[0001] The present disclosure relates to a liquid crystalline resin and a method for producing the same. [Background technology]

[0002] Liquid crystal resins have a good balance of excellent mechanical strength, heat resistance, chemical resistance, electrical properties, etc., and also have excellent dimensional stability, and therefore are widely used as high-performance engineering plastics.

[0003] For example, when a liquid crystalline resin is used as a material for a film for a printed circuit board, an insulating tape substrate, or the like, various properties such as heat resistance, low-temperature formability, chemical resistance, etc. are desired, and liquid crystalline resins having such properties have been developed. Furthermore, a film produced using a liquid crystalline resin as a material is desired to have a specific surface roughness and color suitable for the application. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. H05-186671 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, it has not been easy to adjust the surface roughness and hue of a film made of a liquid crystalline resin to a desired range.

[0006] An object of the present disclosure is to provide a liquid crystalline resin that, when used as a film material, produces a film having a desired surface roughness and / or hue, and a method for producing the same. [Means for solving the problem]

[0007] As a result of extensive research, the inventors discovered that the surface roughness and / or hue of a film made from a liquid crystalline resin can be adjusted by adjusting the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the liquid crystalline resin molecule within a specific range, and thus completed the present invention.

[0008] The present disclosure includes the following aspects. [1] The composition contains 90 mol% or more of structural units derived from aromatic hydroxycarboxylic acids or derivatives thereof among all structural units, It has an ester bond and a ketone bond in the molecule. A liquid crystal resin, in which the amount of ketone bonds is 0.5 to 1.4 millimol% based on the total amount of ester bonds and ketone bonds. [2] A method for producing a liquid crystalline resin, comprising: The production method includes forming ketone bonds in an amount such that the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 millimol%, by carrying out a melt polycondensation reaction at 300°C to 360°C of raw material monomers containing structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof in an amount of 90 mol% or more of all structural units, and allowing the reaction product to remain in a molten state in a reaction vessel, thereby forming ketone bonds. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a liquid crystalline resin that, when used as a film material, produces a film having a desired surface roughness and / or color, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present disclosure will be described in detail below. The present disclosure is not limited to the following embodiment, and can be implemented by making appropriate modifications within the scope that does not impair the effects of the present disclosure. The configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims. Each feature disclosed herein may be combined with any other feature disclosed herein. When a specific description given for one embodiment also applies to other embodiments, that description may be omitted in the other embodiments. In this disclosure, the expression "X to Y" regarding a numerical range means "X or more and Y or less." When a specific description given for one embodiment also applies to other embodiments, that description may be omitted in the other embodiments.

[0011] [First embodiment (liquid crystal resin)] The liquid crystalline resin according to this embodiment is a liquid crystalline resin that contains 90 mol % or more of all structural units (100 mol %) that are derived from aromatic hydroxycarboxylic acid or a derivative thereof, has ester bonds and ketone bonds in the molecule, and the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is more than 0.43 mmol % and less than 1.48 mmol %.

[0012] That is, in one embodiment, the liquid crystal resin is a polymer having repeating units including constitutional units derived from an aromatic hydroxycarboxylic acid or a derivative thereof. In one embodiment, the liquid crystalline resin is a polymer having repeating units including a structural unit derived from an aromatic hydroxycarboxylic acid or a derivative thereof and a structural unit derived from another compound. The other compound will be described later. In one embodiment, the liquid crystal resin is a polymer having repeating units composed of structural units derived from an aromatic hydroxycarboxylic acid or a derivative thereof. In one embodiment, the liquid crystal resin is a polymer having repeating units composed of structural units derived from an aromatic hydroxycarboxylic acid or a derivative thereof and structural units derived from other compounds. "Derived from" means the reaction residue after the polycondensation reaction of the monomer components.

[0013] In one embodiment, the liquid crystalline resin is an aromatic polyester or an aromatic polyester amide.

[0014] "Liquid crystallinity" refers to the ability to form an optically anisotropic melt phase. The properties of an anisotropic melt phase can be confirmed by a conventional polarization examination method using crossed polarizers. More specifically, the anisotropic melt phase can be confirmed by observing a molten sample placed on a Leitz hot stage at 40x magnification using a Leitz polarizing microscope under a nitrogen atmosphere. When a resin with liquid crystallinity is examined between crossed polarizers, polarized light usually passes through, even when the resin is in a molten, stationary state, demonstrating optical anisotropy.

[0015] (Monomer composition) Non-limiting examples of aromatic hydroxycarboxylic acids and derivatives thereof include 4-hydroxybenzoic acid (HBA), 6-hydroxy-2-naphthoic acid (HNA), 3-hydroxybenzoic acid, 6-hydroxy-3-naphthoic acid, 6-hydroxy-4-naphthoic acid, 4-hydroxy-4'-carboxydiphenyl ether, 2,6-dichloro-p-hydroxybenzoic acid, 2-chloro-p-hydroxybenzoic acid, 2,6-dimethyl-p-hydroxybenzoic acid, 2,6-difluoro-p-hydroxybenzoic acid, 4-hydroxy-4'-biphenylcarboxylic acid, vanillic acid, and derivatives thereof, with one or more of HBA, HNA, 4-hydroxy-4'-biphenylcarboxylic acid, and derivatives thereof being preferred. In particular, from the viewpoint of availability, it is more preferable that the liquid crystal resin contains one or more selected from HBA, HNA, and derivatives thereof. The liquid crystal resin preferably contains structural units derived from two or more aromatic hydroxycarboxylic acids or derivatives thereof, and more preferably contains a structural unit derived from HBA and a structural unit derived from HNA.

[0016] Here, in this specification, the term "derivative" refers to a compound whose molecular structure has been partially changed and which can be polymerized by melt polymerization. Examples include acylated compounds in which a phenolic hydroxyl group and / or an amino group is acylated with an acylating agent, acid halides in which a carboxyl group is halogenated with a halogenating agent, acid anhydrides, and alkyl esters (having about 1 to 4 carbon atoms).

[0017] In one embodiment, the liquid crystal resin contains 90 mol% or more of structural units derived from aromatic hydroxycarboxylic acid or its derivatives based on all structural units (100 mol%), and may contain 95 mol%, 96 mol%, 97 mol%, 98 mol%, 99 mol%, or 100 mol%, or may contain any of these as the upper and / or lower limits of the range. In this specification, the content of the structural units can be calculated from the amounts of raw materials charged during polymerization, or can be measured by instrumental analysis using gas chromatography.

[0018] In one embodiment, when the liquid crystalline resin contains two or more structural units derived from aromatic hydroxycarboxylic acids or derivatives thereof, the content of each structural unit in all structural units of the liquid crystalline resin may be 10 mol%, 20 mol%, 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, or 80 mol%, respectively, as long as the total does not exceed 100 mol%, or any of these may be the upper and / or lower limit.

[0019] In one embodiment, when the liquid crystalline resin contains, as structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof, structural units derived from HBA and structural units derived from HNA, the content of the structural units derived from HBA is, with the total not exceeding 100 mol%, preferably 10 mol% or more, and more preferably 24 mol% or more, of all structural units of the liquid crystalline resin, and the content of the structural units derived from HNA is, with the total not exceeding 100 mol%, preferably 10 mol% or more, and more preferably 20 mol% or more. In the liquid crystalline resin, when the content of the structural units derived from HBA is 24 mol% or more, it may be 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, 73 mol%, 79 mol%, or 80 mol%, or it may be a range having any of these as the upper and / or lower limits. In one embodiment, the content of the structural units derived from HBA in all structural units of the liquid crystalline resin may be 24 mol% to 73 mol%, 24 mol% to 80 mol%, or 73 mol% to 80 mol%. In the liquid crystalline resin, when the content of structural units derived from HNA is 20 mol% or more, it may be 25 mol%, 27 mol%, 30 mol%, 40 mol%, 50 mol%, 60 mol%, 70 mol%, 75 mol%, or 76 mol%, or it may be a range with any of these as the upper and / or lower limits. In one embodiment, the content of structural units derived from HNA in all structural units of the liquid crystalline resin may be 20 mol% to 76 mol%, 27 mol% to 76 mol%, or 20 mol% to 27 mol%.

[0020] The liquid crystal resin may contain, in addition to the constituent units derived from the aromatic hydroxycarboxylic acid or a derivative thereof, constituent units derived from one or more other compounds.

[0021] Non-limiting examples of the other compounds include aromatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic diols, alicyclic diols, aromatic hydroxylamines, alicyclic hydroxylamines, aromatic diamines, alicyclic diamines, and derivatives thereof.

[0022] Non-limiting examples of aromatic dicarboxylic acids include terephthalic acid (TA), isophthalic acid (IA), 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following formula (I):

[0023] Formula (I): TIFF2025168786000001.tif23170(Y:-(CH2) n -(n=1 to 4) and -O(CH2) n O-(n=1 to 4).

[0024] Non-limiting examples of alicyclic dicarboxylic acids include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, etc. Non-limiting examples of derivatives thereof include alkyl esters (having about 1 to 4 carbon atoms) and halides of the above compounds.

[0025] Non-limiting examples of aromatic diols include 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl (BP), hydroquinone, resorcinol, a compound represented by the following formula (II), and a compound represented by the following formula (III).

[0026] Formula (II): TIFF2025168786000002.tif23170 (X is a group selected from alkylene (C1 to C4), alkylidene, -O-, -SO-, -SO2-, -S-, and -CO-.)

[0027] Formula (III): TIFF2025168786000003.tif23170

[0028] Non-limiting examples of alicyclic diols include 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, etc. Non-limiting examples of derivatives thereof include alkyl esters (having about 1 to 4 carbon atoms) and halides of the above compounds.

[0029] Non-limiting examples of aromatic hydroxyamines include 4-aminophenol, 3-aminophenol, N-acetyl-p-aminophenol (APAP), and the like. Non-limiting examples of alicyclic hydroxyamines include 4-aminocyclohexanol, 3-aminocyclopentanol, and the like. Non-limiting examples of derivatives of aromatic or alicyclic hydroxyamine include alkyl esters (having about 1 to 4 carbon atoms) and halides of the above compounds.

[0030] Non-limiting examples of aromatic diamines include 1,4-phenylenediamine. Non-limiting examples of alicyclic diamines include 1,4-cyclohexanediamine, 1,3-cyclopentanediamine, and the like. Non-limiting examples of derivatives of aromatic or alicyclic diamines include alkyl esters (having about 1 to 4 carbon atoms) and halides of the above compounds.

[0031] The other compound is preferably an aromatic dicarboxylic acid, an aromatic diol, and / or an aromatic amine, more preferably an aromatic dicarboxylic acid and / or an aromatic diol, and even more preferably an aromatic dicarboxylic acid. The aromatic dicarboxylic acid is preferably TA, IA, and / or 2,6-naphthalenedicarboxylic acid, more preferably TA.

[0032] When the liquid crystal resin contains a structural unit derived from an aromatic hydroxycarboxylic acid or a derivative thereof and a structural unit derived from one or more other compounds, the content of the other compounds in all structural units of the liquid crystal resin is 10 mol% or less, and may be 5 mol%, 3 mol%, 1 mol%, 0.9 mol%, 0.8 mol%, 0.7 mol%, 0.6 mol%, 0.5 mol%, 0.4 mol%, 0.3 mol%, 0.2 mol%, or 0.1 mol%, or may be within a range with any of these upper and / or lower limits. In one embodiment, the content of the other compounds in all structural units of the liquid crystal resin may be 0 mol% to 5 mol%, 0 mol% to 3 mol%, 0 mol% to 1 mol%, or 0 mol% to 0.7 mol%.

[0033] Examples of the structural units (monomers) contained in the liquid crystal resin include: (1)(a) containing at least one compound selected from the group consisting of aromatic hydroxycarboxylic acids and derivatives thereof (preferably consisting of at least one compound selected from the group consisting of aromatic hydroxycarboxylic acids and derivatives thereof), or (2) (a) at least one compound selected from the group consisting of aromatic hydroxycarboxylic acids and derivatives thereof, and (b) at least one compound selected from the group consisting of aromatic or alicyclic dicarboxylic acids, aromatic or alicyclic diols, aromatic or alicyclic hydroxyamines, aromatic or alicyclic diamines, and derivatives thereof (preferably consisting only of the compound (a) and the compound (b)). Examples include: Furthermore, a molecular weight modifier may be used in combination with the above-mentioned constituent components, if necessary.

[0034] In one embodiment, the liquid crystalline resin contains a structural unit derived from HBA and / or HNA as a structural unit derived from an aromatic hydroxycarboxylic acid, and may contain a structural unit derived from TA as a structural unit derived from another compound. In one embodiment, the liquid crystalline resin may be a liquid crystalline resin comprising a structural unit derived from HBA and / or HNA as the structural unit derived from an aromatic hydroxycarboxylic acid, and a structural unit derived from TA as the structural unit derived from another compound.

[0035] (ketone binding amount) The liquid crystal resin has an ester bond and a ketone bond in its molecule, and the amount of the ketone bond relative to the total amount of the ester bond and the ketone bond is more than 0.43 millimol % and less than 1.48 millimol %.

[0036] The amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is more than 0.43 mmol% and less than 1.48 mmol%, and may be 0.5 mmol%, 0.6 mmol%, 0.7 mmol%, 0.8 mmol%, 0.9 mmol%, 0.1 mmol%, or 1.5 mmol%, or may be within a range with any of these as upper and / or lower limits. Furthermore, the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds may be 0.44 mmol%, 0.53 mmol%, 0.67 mmol%, 0.72 mmol%, 0.88 mmol%, 0.95 mmol%, 0.96 mmol%, 1.45 mmol%, or 1.47 mmol%, or may be within a range with any of these as upper and / or lower limits. In one embodiment, the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the liquid crystal resin may be 0.5 mmol % to 1.4 mmol %, or 0.5 mmol % to 1.0 mmol %.

[0037] When the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the molecule is more than 0.43 millimol% and less than 1.48 millimol%, when the liquid crystalline resin is used as a material for a film (preferably a melt-extruded film), the film is more likely to have the desired hue (L value) and / or the desired surface roughness.

[0038] The amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in a molecule can be calculated by the pyrolysis gas chromatography method described in Polymer Degradation and Stability 76 (2002) 85-94. For example, a liquid crystalline resin is heated in the presence of tetramethylammonium hydroxide (TMAH) using a pyrolysis apparatus (e.g., "PY2020iD" manufactured by Frontier Labs, Inc.) to generate gas through pyrolysis / methylation. This gas is analyzed using gas chromatography ("GC-6890N" manufactured by Agilent Technologies, Inc.), and the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds can be calculated from the ratio of the peak area derived from ketone bonds to the peak area derived from ester bonds.

[0039] The amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the liquid crystal resin can be adjusted, for example, by adjusting the polymerization temperature (final polymerization temperature), the residence time in the reaction vessel after polymerization (residence time), and / or the amount of catalyst used in the preparation process of the liquid crystal resin. For example, the higher the final polymerization temperature, the greater the amount of ketone bonds. Furthermore, the longer the residence time after the melt polycondensation reaction, the greater the amount of ketone bonds. For example, when the polymerization temperature is 325°C in the preparation process of the liquid crystal resin, the residence time is more than 15 minutes but less than 100 minutes, and the catalyst is 0.001 to 1 mass% relative to the total weight of the raw material monomers. This allows the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the prepared liquid crystal resin to be adjusted to more than 0.43 millimol% and less than 1.48 millimol%. In contrast, when the final polymerization temperature is low (for example, about 310°C), such as in a method in which an oligomer is formed from a monomer and then polymerized in the solid phase, ketone bonds are unlikely to be formed, and therefore the amount of ketone bonds is unlikely to increase even if the residence time is extended.

[0040] (Other characteristics) The molecular weight (number average molecular weight Mn) of the liquid crystalline resin is not particularly limited, and for a resin obtained by a melt polymerization process, it is preferably 10,000 to 100,000, and more preferably 15,000 to 80,000. For a resin obtained by a solid-state polymerization process, it is preferably 12,000 to 120,000, and more preferably 15,000 to 100,000. The number average molecular weight Mn can be measured by gel permeation chromatography.

[0041] The melting point of the liquid crystalline resin is not particularly limited and can be set to 250 to 380° C. The melt viscosity of the liquid crystalline resin is not particularly limited, and for a resin obtained by melt polymerization, it is preferred to use a cylinder temperature 10 to 30° C. higher than the melting point of the liquid crystalline resin and a shear rate of 1000 sec -1 The melt viscosity measured at this temperature is preferably 5 Pa·s or more and 150 Pa·s or less, more preferably 10 Pa·s or more and 100 Pa·s or less. Furthermore, when the solid-state polymerization step is carried out, the resin is polymerized at a cylinder temperature 10 to 30°C higher than the melting point of the liquid crystalline resin and a shear rate of 1000 sec -1 The melt viscosity measured by is preferably 5 Pa·s or more and 200 Pa·s or less, and more preferably 10 Pa·s or more and 150 Pa·s or less.

[0042] The "cylinder temperature 10 to 30°C higher than the melting point of the liquid crystalline resin" means the cylinder temperature at which the liquid crystalline resin can be melted to an extent that allows measurement of the melt viscosity, and the cylinder temperature higher than the melting point varies depending on the type of raw material resin within the range of 10 to 30°C. The liquid crystalline resin can be in the form of a powder or granular mixture, or can also be in the form of a molten mixture (melt-kneaded product) such as pellets.

[0043] The liquid crystal resin was measured by using a thermogravimetric analyzer. 10 mg of the liquid crystal resin was heated to a temperature 25°C higher than the melting point of the liquid crystal resin (T m 2The weight loss (mass %) when held at +25°C for 30 minutes is preferably 1.2% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.8% by mass or less. When the weight loss (mass %) is 1.2% by mass or less, the amount of gas generated during melting is small, and therefore, swelling (blistering) of the molded product due to the generated gas can be suppressed.

[0044] (Application) The liquid crystalline resin according to this embodiment can be used as a material for the resin composition according to the third embodiment and as a material for the molded article according to the fourth embodiment. The details are as described in the third and fourth embodiments.

[0045] In particular, the liquid crystalline resin according to this embodiment or the resin composition according to the third embodiment can be preferably used as a material for producing a film because the film produced using these materials has a desired hue and / or surface roughness. That is, the liquid crystalline resin according to this embodiment or the resin composition according to the third embodiment is a liquid crystalline resin or resin composition for a film. In one embodiment, the film is a melt-extruded film, and the liquid crystalline resin according to this embodiment or the resin composition according to the third embodiment can be used to produce a melt-extruded film, i.e., a liquid crystalline resin or resin composition for a melt-extruded film.

[0046] [Second embodiment (method for producing liquid crystal resin)] The method for producing a liquid crystalline resin according to this embodiment is a method for forming ketone bonds in an amount such that the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 millimol%, and includes melt polycondensation reaction of raw material monomers containing 90 mol% or more of structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof in all structural units at 300°C to 360°C, and allowing the reaction product to remain in a molten state in a reaction vessel, thereby forming ketone bonds.

[0047] The method for producing a liquid crystalline resin according to this embodiment can provide the liquid crystalline resin according to the first embodiment. That is, the method for producing a liquid crystalline resin according to this embodiment is the same as the method for producing a liquid crystalline resin according to the first embodiment.

[0048] The liquid crystalline resin of the first embodiment is produced by polymerization using a direct polymerization method, an ester exchange method, etc. For the polymerization, a melt polymerization method, a solution polymerization method, a slurry polymerization method, a solid-state polymerization method, etc., or a combination of two or more of these methods is used, and a melt polymerization method or a combination of a melt polymerization method and a solid-state polymerization method is preferably used.

[0049] In one embodiment, the method for producing a liquid crystalline resin according to the present embodiment includes the steps of: (a) preparing raw materials for a liquid crystalline resin in a reaction vessel; (b) subjecting the raw materials prepared in step (a) to a melt polycondensation reaction at 300°C to 360°C; and (c) allowing the reaction product to remain in a molten state within the reaction vessel. As a result, ketone bonds are formed in an amount that gives a ratio of 0.5 to 1.4 millimol % of the ketone bonds to the total amount of ester bonds and ketone bonds.

[0050] (Step (a)) In step (a), raw materials for the liquid crystalline resin are prepared in a reaction vessel by charging raw materials including raw material monomers into the reaction vessel.

[0051] The raw materials include raw material monomers, which include "structural units derived from aromatic hydroxycarboxylic acids and derivatives thereof" described in the "Monomer composition" of the first embodiment, or "structural units derived from aromatic hydroxycarboxylic acids and derivatives thereof" and "structural units derived from other compounds." In one embodiment, the raw material monomer comprises "structural units derived from aromatic hydroxycarboxylic acids and derivatives thereof" or "structural units derived from aromatic hydroxycarboxylic acids and derivatives thereof" and "structural units derived from other compounds" as described in the "Monomer composition" of the first embodiment.

[0052] Examples and preferred examples of the blending of raw material monomers are as described in the first embodiment.

[0053] The raw material monomer may be charged into the reaction vessel as it is, i.e., a raw material monomer that has not been treated with respect to acylation of the hydroxyl group, or a raw material monomer whose terminal has been activated by acylation in a pretreatment step may be charged into the reaction vessel. Acylation of the hydroxyl groups of the raw material monomer can be achieved by providing an acylation step with an acylating agent in or before step (a).

[0054] In one embodiment, the feedstock in step (a) comprises feedstock monomers and an acylating agent.

[0055] Non-limiting examples of acylating agents include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, monochloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, succinic anhydride, and β-bromopropionic anhydride. At least one selected from these can be used. From the standpoint of cost and ease of handling, preferred examples include carboxylic acid anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, and isobutyric anhydride. Among these, acetic anhydride is preferred from the standpoint of ease of availability.

[0056] From the viewpoint of ease of reaction control, the amount of the acylating agent used is preferably 1.0 to 1.1 times, and more preferably 1.01 to 1.05 times, the total hydroxyl group equivalent of the raw material monomers. The acylation step may include raising the temperature to 120°C to 160°C, preferably 130°C to 150°C, more preferably 140°C, and reacting at the raised temperature for 0.5 to 5 hours, preferably 0.5 to 2 hours, more preferably 1 hour, thereby acylating the raw material monomer.

[0057] The acylation step can generally be carried out under normal pressure (atmospheric pressure). For example, it can be carried out under a pressure of 1 atmosphere (101.3 kPa) to 1.1 atmospheres (111.4 kPa). Under reduced pressure, the acylating agent is more likely to be distilled out of the system, and the acylation rate is more likely to decrease due to by-products produced under increased pressure.

[0058] In one embodiment, the feedstock in step (a) comprises feedstock monomers and an acylating agent and / or catalyst.

[0059] Non-limiting examples of the catalyst include metal salt catalysts such as potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and tris(2,4-pentanedionato)cobalt(III), and organic compound catalysts such as 1-methylimidazole and 4-dimethylaminopyridine. Potassium acetate, sodium acetate, and / or magnesium acetate are preferred, and potassium acetate is more preferred.

[0060] The amount of catalyst used is 0.001 to 1 mass %, and preferably 0.001 to 0.2 mass %, based on the total weight of the raw material monomers, from the viewpoint of easy adjustment of the ketone bond amount.

[0061] (Step (b)) In step (b), raw material monomers are subjected to a melt polycondensation reaction at 300°C to 360°C. The melt polycondensation reaction temperature is preferably 310°C to 360°C, and more preferably 320°C to 350°C. When the reaction temperature is 320°C to 350°C, it may be 320°C, 325°C, 340°C, 345°C, or 320°C to 340°C.

[0062] By carrying out the reaction at 300 to 400°C, the ketone bond content (the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds) of the produced liquid crystalline resin is likely to be greater than 0.43 mmol% and less than 1.48 mmol%. A liquid crystalline resin having a ketone bond content greater than 0.43 mmol% and less than 1.48 mmol% is likely to have a desired hue (L value of 80 or more) and / or a desired surface roughness (Wc of less than 5). In contrast, in a method in which raw material monomers are reacted to form an oligomer and then a polymer is formed by solid-state polymerization, the reaction temperature is low, making it difficult to generate ketone bonds, and it is difficult to increase the amount of ketone bonds to more than 0.43 millimol% relative to the total amount of ester bonds and ketone bonds.

[0063] The reaction time is not limited and is, for example, 10 minutes to 10 hours, preferably 10 minutes to 5 hours, more preferably 15 minutes to 3 hours, and even more preferably 30 minutes to 1 hour. In one embodiment, the reaction time is 30 minutes.

[0064] The molecular weight (number average molecular weight Mn) of the liquid crystalline resin obtained in the melt polycondensation step (b) is preferably 10,000 to 100,000, more preferably 15,000 to 80,000.

[0065] The reaction can be carried out under a pressure of, for example, 400 Pa to 500 kPa, preferably 500 Pa to 300 kPa, and more preferably 600 Pa to 150 kPa.

[0066] (Process (c)) In step (c), the reaction product produced in step (b) is allowed to remain in a molten state in a reaction vessel. By step (b) and this step (c), ketone bonds can be formed in an amount such that the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 millimol%. The residence time is preferably 20 to 80 minutes. When the residence time is 20 to 80 minutes, it may be 20 minutes, 23 minutes, 35 minutes, 45 minutes, 55 minutes, 62 minutes, or 80 minutes, or may be within a range having any of these as the upper and / or lower limit.

[0067] By setting the residence time to 20 to 80 minutes, the ketone bond content (the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds) of the produced liquid crystalline resin is likely to be more than 0.43 mmol% and less than 1.48 mmol%. A liquid crystalline resin having a ketone bond content of more than 0.43 mmol% and less than 1.48 mmol% is likely to have a desired hue (L value of 80 or more) and / or a desired surface roughness (Wc of less than 5).

[0068] The residence temperature of the reaction product produced in step (b) in step (c) is not limited as long as the reaction product is in a molten state. For example, it may be the temperature at which the raw material monomers are melt-condensed in step (b), i.e., it may be within the range of the examples and preferred examples described in "step (b)" (300°C to 360°C, preferably 310°C to 360°C, more preferably 320°C to 350°C). The residence temperature in step (c) may be the same as or different from the melt-condensation temperature of the raw material monomers in step (b).

[0069] Step (c) is preferably carried out under normal pressure (atmospheric pressure). The pressurized or high pressure atmosphere in step (b) can be reduced to atmospheric pressure in step (c) or before step (c), for example, by introducing nitrogen into the reaction vessel.

[0070] (Other steps (d)) The method for producing a liquid crystalline resin according to this embodiment may further include solid-state polymerization of the product (liquid crystalline resin) obtained in the above steps (a) to (c). Solid-state polymerization can increase the molecular weight of the raw material resin, thereby producing a liquid crystalline resin with excellent strength and heat resistance.

[0071] Solid-state polymerization can be carried out by a conventionally known method. For example, it can be carried out by heating the raw material resin at a temperature 10°C to 120°C lower than the liquid crystal formation temperature under reduced pressure or vacuum in a stream of inert gas such as nitrogen gas. Note that since the melting point of the liquid crystalline resin increases as the solid-state polymerization proceeds, it is also possible to carry out solid-state polymerization at a temperature higher than the original melting point of the raw material resin. Solid-state polymerization can be carried out at a constant temperature or by gradually increasing the temperature. The heating method is not particularly limited, and microwave heating, heater heating, etc. can be used.

[0072] (Other process (e)) The method for producing a liquid crystalline resin according to this embodiment may include pelletizing the product (liquid crystalline resin) obtained in the above steps (a) to (c). By pelletizing, a liquid crystalline resin in the form of pellets (liquid crystalline resin pellets) can be obtained. The liquid crystalline resin pellets are easy to handle and can be suitably used, for example, for producing the molded article described in the fourth embodiment.

[0073] [Third embodiment (resin composition)] The liquid crystalline resin according to the first embodiment can be used to prepare a liquid crystalline resin composition by blending other components according to the purpose of use and / or within the range that maintains the desired properties. The resin composition according to this embodiment is a liquid crystalline resin composition containing the liquid crystalline resin according to the first embodiment and other components.

[0074] Examples of other components include fillers, other resins, antioxidants, stabilizers, pigments, crystal nucleating agents and other additives.

[0075] The filler may be any of various fibrous, granular, and plate-like inorganic and organic fillers.

[0076] Examples of inorganic fillers include fibrous, granular, and plate-like inorganic fillers.

[0077] Non-limiting examples of fibrous inorganic fillers include glass fibers, milled glass fibers, asbestos fibers, silica fibers, silica-alumina fibers, alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, silicate fibers such as wollastonite, magnesium sulfate fibers, aluminum borate fibers, and metal fibers such as stainless steel, aluminum, titanium, copper, and brass.

[0078] Non-limiting examples of powdery inorganic fillers include carbon black, graphite, silica, quartz powder, glass beads, glass balloons, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, silicates such as wollastonite, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony trioxide, and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, ferrite, silicon carbide, silicon nitride, boron nitride, and various metal powders.

[0079] Non-limiting examples of platy inorganic fillers include mica, glass flakes, talc, various metal foils, and the like.

[0080] Examples of the organic filler include heat-resistant, high-strength synthetic fibers such as aromatic polyester fibers, liquid crystal polymer fibers, aromatic polyamide fibers, and polyimide fibers.

[0081] These inorganic and organic fillers can be used alone or in combination of two or more. A fibrous inorganic filler may be used in combination with a granular or plate-like inorganic filler. The combined use of a fibrous inorganic filler and a granular or plate-like inorganic filler makes it easier to achieve mechanical strength, dimensional accuracy, and / or desired electrical properties. For example, glass fiber may be used in combination as a fibrous filler, and mica and talc may be used in combination as a plate-like filler. Such a combination makes it easier for the liquid crystalline resin composition to have the desired heat distortion temperature, mechanical properties, etc.

[0082] When using these fillers, a sizing agent or a surface treatment agent may be used as needed.

[0083] Examples of other resins include thermoplastic resins such as polyarylate, polyphenylene sulfide, polyphenylene ether, polyether ether ketone, polyetherimide, cycloolefin polymer, polyamide, polyamideimide, polyimide, epoxy group-containing olefin copolymer, and epoxy group-containing styrene copolymer, and two or more of these may be used in combination.

[0084] Additives such as antioxidants, stabilizers, pigments, and crystal nucleating agents can be appropriately selected from components well known to those skilled in the art.

[0085] (Application) The resin composition according to this embodiment can be used as a material for the molded article according to the fourth embodiment. The details are as described in the fourth embodiment.

[0086] [Fourth embodiment (molded product)] The liquid crystal resin according to the first embodiment or the liquid crystal resin composition according to the third embodiment can be molded to obtain a molded product. That is, the molded article according to this embodiment is a molded article manufactured using the liquid crystalline resin according to the first embodiment and / or the liquid crystalline resin composition according to the third embodiment as a material.

[0087] (Molded products and their properties) Non-limiting examples of molded articles include films (liquid crystalline resin films), three-dimensional molded articles, fibers, and the like. The film can be used, for example, but not limited to, as an industrial film such as an insulating film, a waterproof film, or a heat-resistant film, or as a film for packaging materials such as a gas barrier film. Such films can be used in a variety of fields.

[0088] The liquid crystalline resin according to the first embodiment or the resin composition according to the third embodiment can be used to produce a film (liquid crystalline resin film) having a desired hue and / or a desired surface roughness as a film, and therefore the molded article according to this embodiment is preferably a film. The film is preferably a film formed and / or produced by melt extrusion, i.e., the formed article is preferably a melt-extruded film.

[0089] When the molded article is a film, the thickness of the film is not limited as long as it is within a range suitable for the intended use of the molded article, but from the viewpoint of applications such as printed circuit boards, it is preferably 1 μm to 3 mm, more preferably 5 μm to 2 mm, even more preferably 10 μm to 1 mm, and particularly preferably 20 μm to 200 μm. When the thickness of the film is 20 μm to 200 μm, it may be 20 μm, 100 μm, or 200 μm, and may be within a range with any of these as the upper and / or lower limit.

[0090] When the molded article is a melt-extruded film, the L value thereof is preferably 80 or more, more preferably 80-100, and even more preferably 80-90. When the L value is 80 to 90, it may be 80, 81, 84, 86, 87, 88, 89, or 90, or may be a range with any of these as the upper and / or lower limits. Furthermore, when the L value is 80 to 90, it may be 81.2, 84.1, 86.6, 86.8, 87.7, 88.3, ​​88.7, 88.8, or 90.0, or may be a range with any of these as the upper and / or lower limits. The L value of the film can be measured using a spectrophotometer on a test piece measuring 50 mm x 50 mm x 100 μm. The L value can be adjusted by adjusting the amount of ketone bonds relative to the total number of ester bonds and ketone bonds in the molecules of the liquid crystalline resin that is the material for the film. It can also be adjusted by adjusting the cylinder temperature, die temperature, and residence time of the extruder during extrusion film production.

[0091] When the molded article is a melt-extruded film, the b value is preferably 5-30, and may be 8-25 or 9-24. The b value can be measured using a spectrophotometer in the same manner as the L value.

[0092] When the molded article is a melt-extruded film, its surface roughness (Wc) is preferably less than 5, more preferably 3 or less, and even more preferably 2 or less. The surface roughness (Wc) can be measured using a surface roughness measuring instrument. The surface roughness (Wc) of the film can be adjusted by adjusting the amount of ketone bonds relative to the total number of ester bonds and ketone bonds in the molecules of the liquid crystalline resin that is the material for the film.

[0093] When the molded article according to this embodiment is a liquid crystalline resin film, it is suitably used as a film for a printed circuit board, an insulating tape base material, or the like.

[0094] (Method of manufacturing molded products) In one embodiment, when the molded article according to this embodiment is a melt-extruded film, it can be produced by a production method including melting the liquid crystalline resin according to the first embodiment and / or the liquid crystalline resin composition according to the third embodiment, and extruding the molten resin and / or resin composition into a sheet shape.

[0095] In one embodiment, a film may be produced by melting liquid crystalline resin pellets in a single-screw extruder, discharging the molten resin from the extruder and supplying it to a die, and extruding the molten resin from the die in the form of a sheet, which is then cooled and solidified. The liquid crystalline resin melted in the extruder is extruded from a die in the form of a sheet, which is then cast onto, for example, a rotating cooling drum and rapidly cooled and solidified to obtain a film (melt-extruded film). After cooling and solidifying, the film may be stretched longitudinally and then transversely as appropriate, and may finally be wound up into a roll.

[0096] In one embodiment, the die temperature can be set to 250°C to 360°C, preferably 250°C to 350°C, more preferably 280°C to 340°C, and even more preferably 290°C to 330°C.

[0097] In another embodiment, the molded article can be produced by a method known to those skilled in the art. In the case of a melt-extruded film, for example, the molded article can be produced using an extruder by setting the conditions as follows:

[0098] The extruder is, for example, a single-screw type extruder, which is provided with a single screw inside a cylinder. In a single-screw extruder, the cylinder is equipped with a feed port through which liquid crystalline resin pellets are fed into the cylinder. The cylinder is composed of, in order from the feed port side, a feed section that transports a fixed amount of liquid crystalline resin fed from the feed port, a compression section that kneads and compresses the liquid crystalline resin, and a conveying and measuring section that conveys the kneaded and compressed liquid crystalline resin to the discharge port while measuring the discharge amount.

[0099] The screw compression ratio of the extruder is set, for example, to 2.5 to 5.0, and preferably to 2.6 to 4.0. If the screw compression ratio is less than 2.5, the mixture is not sufficiently mixed, undissolved portions are likely to occur, shear heat generation is small, and crystal melting is likely to be insufficient. As a result, it is difficult to reduce the occurrence of particles (particles mixed in the film) and / or thickness fluctuation in the MD direction (the direction of film flow). Conversely, if the screw compression ratio is more than 5.0, excessive shear stress is likely to be applied, which may cause heat generation and deterioration of the liquid crystalline resin, or the liquid crystalline resin molecules may be cleaved, resulting in a decrease in molecular weight.

[0100] The L / D is set to 18 to 45, preferably 21 to 40, more preferably 25 to 35, and even more preferably 28 to 30. If the L / D is less than 18, the resin will not melt or be mixed sufficiently, and fine crystals will likely remain, as in the case of a low screw compression ratio, making it difficult to reduce the occurrence of lumps and / or thickness variations in the MD. Conversely, if the L / D is more than 45, the liquid crystalline resin will remain in the extruder for too long, which will likely cause deterioration of the resin. Furthermore, if the residence time is too long, the liquid crystalline resin molecules will be cleaved, and the molecular weight will likely decrease.

[0101] Here, the screw compression ratio refers to the degree to which the liquid crystalline resin is compressed in a molten state in order to knead it under back pressure, and is expressed as the volume ratio between the supply section and the conveying and metering section (i.e., the volume per unit length of the supply section / the volume per unit length of the conveying and metering section), and is calculated using the outer diameter d1 of the screw shaft of the supply section, the outer diameter d2 of the screw shaft of the conveying and metering section, the groove diameter a1 of the supply section, and the groove diameter a2 of the conveying and metering section. Also, L / D is the ratio of the cylinder length (L) to the cylinder inner diameter (D).

[0102] The liquid crystalline resin is melted by the extruder configured as described above, and the molten resin is continuously fed from the discharge port to the die with a discharge pressure fluctuation of, for example, 10% or less. The molten resin fed to the die by the extruder is then extruded from the die in the form of a sheet, and is cast, for example, on a cooling drum and cooled and solidified to form a film. Here, the melting point T m (℃) and the die set temperature Td (℃) are m -10≦Td≦T m Meet +15. Td <T m If the die temperature is -10, the die temperature setting is too low, which can easily cause lumps to form, and the thickness tends to vary greatly in the MD direction, which can sometimes cause holes to form in parts of the film. m If the die temperature is set to +15, the die temperature is too high, which tends to increase thickness fluctuation in the MD direction, and in some cases, holes may appear in the film. m (°C) and Td (°C) are preferablym -9≦Td≦T m +14, more preferably T m -8≦Td≦T m Meet +13.

[0103] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure are disclosed below. [1] The composition contains 90 mol% or more of structural units derived from aromatic hydroxycarboxylic acids or derivatives thereof among all structural units, It has an ester bond and a ketone bond in the molecule. A liquid crystal resin, in which the amount of ketone bonds is 0.5 to 1.4 millimol% based on the total amount of ester bonds and ketone bonds. [2] The liquid crystal resin according to [1], which contains 95 mol % or more of structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof in all structural units. [3] The liquid crystal resin according to [1] or [2], wherein the aromatic hydroxycarboxylic acid or a derivative thereof is at least one selected from the group consisting of 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4-hydroxy-4'-biphenylcarboxylic acid, and derivatives thereof. [4] The liquid crystalline resin according to any one of [1] to [3], which is for use in a film. [5] Use of the liquid crystalline resin according to any one of [1] to [4] for producing a film. [6] A film comprising the liquid crystalline resin according to any one of [1] to [5]. [7] The film according to [6], having an L value of 80 or more. [8] A method for producing a liquid crystalline resin, comprising: forming ketone bonds in an amount such that the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 millimol%, The production method includes melt polycondensation of raw material monomers containing 90 mol% or more of structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof at 300°C to 360°C, and allowing the reaction product to remain in a molten state in a reaction vessel, thereby forming a ketone bond. [9] A method for producing a film, comprising melting the liquid crystalline resin according to any one of [1] to [4] and discharging it into a sheet shape. [Example]

[0104] The present disclosure will be explained in more detail below by showing examples, but interpretation of the present disclosure is not limited to these examples.

[0105] (1) Preparation of liquid crystalline resin A liquid crystalline resin was prepared by mixing raw materials as shown in Table 1. Specifically, the process is as follows. [Table 1] [Example 1] The following raw materials were charged into a polymerization vessel, and the temperature of the reaction system was raised to 140°C. The reaction was carried out at 140°C for 1 hour under atmospheric pressure (101.3 kPa). The temperature was then further raised to 325°C over 3.5 hours, and the pressure was then reduced to 5 Torr (i.e., 667 Pa) over 20 minutes. Polycondensation was carried out for 0.5 hours while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to return the reduced pressure to atmospheric pressure, and the mixture was allowed to dwell at 325°C for 35 minutes. The mixture was then pressurized, the polymer was discharged from the bottom of the polymerization vessel, and the strands were pelletized to obtain a liquid crystalline resin in pellet form (liquid crystalline resin pellets). (raw materials) 4-Hydroxybenzoic acid (HBA): 1660 g (73 mol%) 6-Hydroxy-2-naphthoic acid (HNA): 837 g (27 mol%) Metal catalyst (potassium acetate catalyst): 165 mg Acylating agent (acetic anhydride): 1714g (1.02 times the total hydroxyl equivalent of HBA and HNA)

[0106] [Example 2] Liquid crystalline resin pellets were obtained in the same manner as in Example 1, except that the retention time at 325°C was changed from 35 minutes to 62 minutes.

[0107] [Example 3] Liquid crystalline resin pellets were obtained in the same manner as in Example 1, except that the retention time at 325°C was changed from 35 minutes to 80 minutes.

[0108] [Example 4] After the following raw materials were charged into a polymerization vessel, the temperature of the reaction system was raised to 140°C and the reaction was carried out at 140°C for 1 hour under normal pressure (101.3 kPa). The temperature was then further raised to 340°C over 3.5 hours, and the pressure was then reduced to 10 Torr (i.e., 1330 Pa) over 20 minutes. Polycondensation was carried out for 0.5 hours while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to return the reduced pressure to normal pressure, and the mixture was allowed to dwell at 340°C for 20 minutes. The mixture was then pressurized, the polymer was discharged from the bottom of the polymerization vessel, and the strands were pelletized to obtain liquid crystalline resin pellets. (raw materials) 4-Hydroxybenzoic acid (HBA): 2524 g (79.3 mol%) 6-Hydroxy-2-naphthoic acid (HNA): 867 g (20 mol%) Terephthalic acid (TA): 27 g (0.7 mol%) Metal catalyst (potassium acetate catalyst): 150 mg Acylating agent (acetic anhydride): 2336 g (1.02 times the total hydroxyl equivalent of HBA and HNA)

[0109] [Example 5] Liquid crystalline resin pellets were obtained in the same manner as in Example 4, except that the retention time at 340°C was changed from 20 minutes to 45 minutes.

[0110] [Example 6] After the following raw materials were charged into a polymerization vessel, the temperature of the reaction system was raised to 140°C and the reaction was carried out at 140°C for 1 hour under normal pressure (101.3 kPa). The temperature was then further raised to 340°C over 3.5 hours, and the pressure was then reduced to 10 Torr (i.e., 1330 Pa) over 20 minutes. Polycondensation was carried out for 0.5 hours while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to return the reduced pressure to normal pressure, and the mixture was allowed to dwell at 340°C for 23 minutes. The mixture was then pressurized, the polymer was discharged from the bottom of the polymerization vessel, and the strands were pelletized to obtain liquid crystalline resin pellets. (raw materials) 4-Hydroxybenzoic acid (HBA): 448 g (23.3 mol%) 6-Hydroxy-2-naphthoic acid (HNA): 1988 g (76 mol%) Terephthalic acid (TA): 16.2 g (0.7 mol%) Metal catalyst (potassium acetate catalyst): 165 mg Acylating agent (acetic anhydride): 1,438 g (1.02 times the total hydroxyl equivalent of HBA and HNA)

[0111] [Example 7] Liquid crystalline resin pellets were obtained in the same manner as in Example 6, except that the retention time at 340°C was changed from 23 minutes to 55 minutes.

[0112] [Comparative Example 1] After the following raw materials were charged into a polymerization vessel, the temperature of the reaction system was raised to 140°C and the reaction was carried out at 140°C for 1 hour under normal pressure (101.3 kPa). The temperature was then further raised to 325°C over 3.5 hours, and the pressure was then reduced to 5 Torr (i.e., 667 Pa) over 20 minutes. Polycondensation was carried out for 0.5 hours while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to return the reduced pressure to normal pressure, and the mixture was allowed to dwell at 325°C for 15 minutes. The mixture was then pressurized, the polymer was discharged from the bottom of the polymerization vessel, and the strands were pelletized to obtain liquid crystalline resin pellets. (raw materials) 4-Hydroxybenzoic acid (HBA): 1660 g (73 mol%) 6-Hydroxy-2-naphthoic acid (HNA): 837 g (27 mol%) Metal catalyst (potassium acetate catalyst): 165 mg Acylating agent (acetic anhydride): 1714g (1.02 times the total hydroxyl equivalent of HBA and HNA)

[0113] Comparative Example 2 Liquid crystalline resin pellets were obtained in the same manner as in Comparative Example 1, except that the retention time at 325°C was changed from 15 minutes to 110 minutes.

[0114] Comparative Example 3 After charging the following raw materials into a polymerization vessel, the temperature of the reaction system was raised to 140°C and the reaction was carried out at 140°C for 1 hour under normal pressure (101.3 kPa). The temperature was then further raised to 340°C over 3.5 hours, and the pressure was then reduced to 10 Torr (i.e., 1330 Pa) over 20 minutes. Polycondensation was carried out for 0.5 hours while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to return the reduced pressure to normal pressure, and the mixture was allowed to dwell at 340°C for 100 minutes. The mixture was then pressurized, the polymer was discharged from the bottom of the polymerization vessel, and the strands were pelletized to obtain liquid crystalline resin pellets. (raw materials) 4-Hydroxybenzoic acid (HBA): 2524 g (79.3 mol%) 6-Hydroxy-2-naphthoic acid (HNA): 867 g (20 mol%) Terephthalic acid (TA): 27 g (0.3 mol%) Metal catalyst (potassium acetate catalyst): 150 mg Acylating agent (acetic anhydride): 2336 g (1.02 times the total hydroxyl equivalent of HBA and HNA)

[0115] Comparative Example 4 After the following raw materials were charged into a polymerization vessel, the temperature of the reaction system was raised to 140°C and the reaction was carried out at 140°C for 1 hour under normal pressure (101.3 kPa). The temperature was then further raised to 340°C over 3.5 hours, and the pressure was then reduced to 10 Torr (i.e., 1330 Pa) over 20 minutes. Polycondensation was carried out for 0.5 hours while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to return the reduced pressure to normal pressure, and the mixture was allowed to dwell at 340°C for 110 minutes. The mixture was then pressurized, the polymer was discharged from the bottom of the polymerization vessel, and the strands were pelletized to obtain liquid crystalline resin pellets. (raw materials) 4-Hydroxybenzoic acid (HBA): 448 g (23.3 mol%) 6-Hydroxy-2-naphthoic acid (HNA): 1988 g (76 mol%) Terephthalic acid (TA): 16.2 g (0.7 mol%) Metal catalyst (potassium acetate catalyst): 165 mg Acylating agent (acetic anhydride): 1,438 g (1.02 times the total hydroxyl equivalent of HBA and HNA)

[0116] (2) Evaluation of liquid crystalline resin [Ketone binding amount] The amount of ketone bonded was calculated by the pyrolysis gas chromatography method described in Polymer Degradation and Stability 76 (2002) 85-94. Specifically, the liquid crystalline resin was heated in the presence of tetramethylammonium hydroxide (TMAH) using a pyrolysis apparatus (Frontier Labs, Inc., "PY2020iD") to generate gas through pyrolysis / methylation. This gas was analyzed using gas chromatography (Agilent Technologies, Inc., "GC-6890N"), and the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds was calculated from the ratio of the peak area derived from ketone bonds to the peak area derived from ester bonds.

[0117] Table 1 shows the amount of ketone bonds in the liquid crystalline resins of each of the Examples and Comparative Examples.

[0118] When the polymerization temperature (final polymerization temperature) was 325°C to 340°C and the residence time in the molten state was 20 minutes to 80 minutes, the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the obtained liquid crystalline resin was 0.53 millimol% to 0.96 millimol%. On the other hand, when the polymerization temperature (final polymerization temperature) was 325°C to 340°C and the residence time in the molten state was 15 minutes or 100 minutes or more, the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the obtained liquid crystalline resin was 0.43 mmol%, or 1.48 mmol% to 1.60 mmol%.

[0119] From the above, it was found that by carrying out polymerization within a specific temperature range and setting the residence time within a specific range, it is possible to adjust the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the molecules of the produced liquid crystalline resin.

[0120] (3) Preparation of liquid crystalline resin film The obtained liquid crystalline resin pellets were used as raw materials and melted in a single screw extruder (20mmφ single screw extruder manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the following conditions: screw compression ratio (3.0-4.0), L / D, and full-flight screw (screw diameter D: 19.8mm) in the feed section of the extruder. The melt was extruded into a film from a T-die (width: 150mm) at the tip of the extruder, with the die temperature set as shown in the "Die Temperature" column in Table 1, and cooled. The take-up speed was adjusted to produce a 100μm thick liquid crystalline resin film (melt-extruded film). Cylinder temperature: same as die temperature setting Screw rotation speed: 30 rpm Discharge amount: 1.6kg / h

[0121] (4) Evaluation of liquid crystalline resin film [Hue (L value and b value)] The liquid crystalline resin film obtained in (3) above was measured for hue (L value and b value) using a spectrophotometer (SE6000, manufactured by Nippon Denshoku Industries Co., Ltd.) Specifically, the liquid crystalline resin film was cut into a size of 50 mm × 50 mm × 100 μm and the measurement was carried out.

[0122] [Surface roughness (Wc)] The surface roughness (Wc) of the liquid crystalline resin film obtained in (3) above was measured using a CNC surface roughness measuring instrument (Mitutoyo Corporation, SURFTEST Extreme SV-3000 CNC). Specifically, the liquid crystalline resin film cut into a size of 60 mm × 15 mm × 100 μm was measured in accordance with JIS B0601 2001.

[0123] Table 1 shows the evaluation results of the liquid crystalline resin films of the examples and comparative examples.

[0124] The melt-extruded films (Examples 1 to 7) produced using a liquid crystalline resin in which the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the molecule was 0.53 mmol% to 0.96 mmol% had a surface roughness of 2 and an L value of 81.2 or more. On the other hand, the melt-extruded film (Comparative Example 1) produced using a liquid crystalline resin in which the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the molecule was 0.43 millimol% had a surface roughness of 5 and an L value of 88.1. The melt-extruded films (Comparative Examples 2 to 4) produced using a liquid crystalline resin in which the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the molecule was 1.48 mmol% to 1.60 mmol% had a surface roughness of 2 and an L value of 77.1 to 78.4.

[0125] In Comparative Examples 1 to 4, no melt-extruded film had both the desired surface roughness (less than 5) and L value (80 or more). A surface roughness of less than 5 is preferred for reducing transmission loss when the film is used in a printed circuit board or the like, and an L value of 80 or more is preferred for improving appearance.

[0126] From the above, it was found that when the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds in the molecules of a liquid crystalline resin is within a specific range, a melt-extruded film produced using the liquid crystalline resin as a material has the surface roughness and hue (L value) desired for the film. [Industrial Applicability]

[0127] When the liquid crystalline resin of the present embodiment is used as a film material, it is possible to produce a film having a desired surface roughness and / or color, and therefore the resin can be suitably used as a film material for printed circuit boards, insulating tape substrates, etc., and has industrial applicability.

Claims

1. The composition contains 90 mol % or more of structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof among all structural units, It has an ester bond and a ketone bond in the molecule. A liquid crystal resin in which the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 millimol %.

2. 2. The liquid crystalline resin according to claim 1, wherein the resin contains 95 mol % or more of structural units derived from an aromatic hydroxycarboxylic acid or a derivative thereof based on all structural units.

3. 3. The liquid crystalline resin according to claim 1, wherein the aromatic hydroxycarboxylic acid or a derivative thereof is at least one selected from the group consisting of 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4-hydroxy-4'-biphenylcarboxylic acid, and derivatives thereof.

4. The liquid crystalline resin according to claim 1 or 2, which is for use in a film.

5. 3. Use of the liquid crystalline resin according to claim 1 or 2 for producing a film.

6. A film comprising the liquid crystalline resin according to claim 1 or 2.

7. 7. The film of claim 6, having an L value of 80 or greater.

8. A method for producing a liquid crystalline resin, comprising: The production method includes forming ketone bonds in an amount such that the amount of ketone bonds relative to the total amount of ester bonds and ketone bonds is 0.5 to 1.4 millimol%, by carrying out a melt polycondensation reaction at 300°C to 360°C of raw material monomers, the raw material monomers containing structural units derived from aromatic hydroxycarboxylic acid or a derivative thereof in an amount of 90 mol% or more of all structural units, and allowing the reaction product to remain in a molten state in a reaction vessel, thereby forming ketone bonds.

9. A method for producing a film, comprising: melting the liquid crystalline resin according to claim 1 or 2 and discharging the melted liquid crystalline resin into a sheet shape.

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