Liquid crystal resin composition for melt extrusion film and film using the same

Abstract

The present invention provides a liquid crystalline resin composition for melt extrusion films that can provide a film with a good balance of film-forming properties and surface smoothness, and a film using the same. [Solution] The liquid crystalline resin composition for melt extruded film according to the present invention contains (A) a liquid crystalline resin and (B) mica, wherein the content of (B) mica is 0.5 to 15% by mass of the entire liquid crystalline resin composition. The (A) liquid crystalline resin is an aromatic polyester or aromatic polyesteramide containing at least one constituent unit selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives. The average particle size of the (B) mica is 50 μm or less.

Description

Technical Field

[0001] The present invention relates to a liquid crystalline resin composition for melt-extruded films and a film using the same.

Background Art

[0002] Liquid crystalline resins have excellent mechanical strength, heat resistance, chemical resistance, electrical properties, etc. in a well-balanced manner, and also have excellent dimensional stability, so they are widely used as high-performance engineering plastics. Further, for example, melt-extruded films made of liquid crystalline resins are also produced by melt-extrusion methods such as the T-die method and the inflation method (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the studies of the present inventors, when a melt-extruded film containing a large amount of a conventional liquid crystalline resin is produced by the T-die method or the inflation method, it is likely to have holes, and in addition to the need for improvement in film-forming properties, although the film-forming properties can be improved by adding a filler, it has been found that the surface roughness increases. The present invention has been made to solve the above problems, and an object thereof is to provide a liquid crystalline resin composition for melt-extruded films and a film using the same that can give a film having excellent film-forming properties and surface smoothness in a well-balanced manner.

Means for Solving the Problems

[0005] The inventors of the present invention conducted extensive research to solve the above problems. As a result, they discovered that the above problems can be solved by using a liquid crystalline resin composition for melt extrusion film containing a liquid crystalline resin and a predetermined amount of mica, and thus completed the present invention. More specifically, the present invention provides the following.

[0006] (1) (A) Liquid crystal resin, and (B) Mica A liquid crystalline resin composition for melt extrusion film containing, A liquid crystalline resin composition for melt extrusion film, wherein the content of (B) mica is 0.5 to 15% by mass relative to the entire liquid crystalline resin composition.

[0007] (2) The liquid crystalline resin composition for melt extruded films according to (1), wherein the liquid crystalline resin (A) is an aromatic polyester or aromatic polyesteramide comprising at least one structural unit selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives.

[0008] (3) The liquid crystalline resin composition for melt extruded films according to (1) or (2), wherein the average particle size of the mica (B) is 50 μm or less.

[0009] (4) A liquid crystalline resin composition for melt extrusion film according to any one of (1) to (3), wherein the melt viscosity of the liquid crystalline resin composition at a temperature 10 to 30°C higher than the melting point of the liquid crystalline resin composition, a strain of 1%, and an angular frequency of 10 rad / s is 80 Pa·s or more and 300 Pa·s or less.

[0010] (5) Use of any of the liquid crystalline resin compositions for melt extrusion films described in (1) to (4) for manufacturing a film.

[0011] (6) A film comprising the liquid crystalline resin composition for melt extrusion film described in any of (1) to (4). [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a liquid crystalline resin composition for melt extrusion films that can give a film with a good balance of film-forming properties and surface smoothness, and a film using the same. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below. However, the present invention is not limited to the embodiments described below.

[0014] <Liquid crystal resin composition for melt-extruded films> The liquid crystalline resin composition for melt-extruded films of the present invention contains (A) a liquid crystalline resin and (B) mica.

[0015] [(A) Liquid crystal resin] The liquid crystalline resin composition for melt-extruded films according to the present invention contains (A) a liquid crystalline resin. (A) can be used alone or in combination of two or more types.

[0016] The (A) liquid crystalline resin used in this invention refers to a melt-processable polymer that has the property of forming an optically anisotropic molten phase. The properties of the anisotropic molten phase can be confirmed by conventional polarization inspection methods using orthogonal polarizers. More specifically, the anisotropic molten phase can be confirmed by using a Leitz polarizing microscope and observing a molten sample placed on a Leitz hot stage under a nitrogen atmosphere at 40x magnification. Liquid crystalline polymers applicable to this invention exhibit optical anisotropy, as polarization is normally transmitted even in a molten, stationary state when inspected between orthogonal polarizers.

[0017] The type of the (A) liquid crystalline resin as described above is not particularly limited, and it is preferably an aromatic polyester and / or an aromatic polyester amide, and more preferably an aromatic polyester amide. Also, a polyester partially containing an aromatic polyester and / or an aromatic polyester amide in the same molecular chain is within the scope. As the (A) liquid crystalline resin, when dissolved in pentafluorophenol at a concentration of 0.1% by mass at 60°C, those having a logarithmic viscosity (I.V.) of preferably at least about 2.0 dl / g, more preferably 2.0 to 10.0 dl / g are preferably used.

[0018] The (A) liquid crystalline resin applicable to the present invention preferably contains at least a structural unit derived from at least one selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives, and particularly preferably, it is an aromatic polyester or an aromatic polyester amide having a structural unit derived from at least one selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives as a constituent component.

[0019] More specifically, (1) A polyester mainly composed of structural units derived from at least one selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives; (2) A polyester mainly composed of (a) structural units derived from at least one selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives and (b) structural units derived from at least one selected from the group consisting of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and their derivatives; (3) A polyester mainly composed of (a) structural units derived from at least one selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives, (b) structural units derived from at least one selected from the group consisting of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and their derivatives, and (c) structural units derived from at least one selected from the group consisting of aromatic diols, alicyclic diols, aliphatic diols, and their derivatives; (4) A polyesteramide mainly composed of: (a) at least one structural unit derived from a group consisting of aromatic hydroxycarboxylic acids and their derivatives; (b) at least one structural unit derived from a group consisting of aromatic hydroxyamines, aromatic diamines, and their derivatives; and (c) at least one structural unit derived from a group consisting of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and their derivatives. (5) Examples include polyesteramides mainly composed of: (a) at least one structural unit derived from a group consisting of aromatic hydroxycarboxylic acids and their derivatives; (b) at least one structural unit derived from a group consisting of aromatic hydroxyamines, aromatic diamines, and their derivatives; (c) at least one structural unit derived from a group consisting of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and their derivatives; and (d) at least one structural unit derived from a group consisting of aromatic diols, alicyclic diols, aliphatic diols, and their derivatives. Further, a molecular weight regulator may be used in combination with the above components as needed.

[0020] (A) In the liquid crystalline resin, from the viewpoint of suppressing the fluctuation of the molecular structure of (A) the liquid crystalline resin, the content of the structural unit derived from at least one selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives is preferably 45 mol% or more, more preferably 50 mol% or more, still more preferably 55 mol% or more, even more preferably more than 60 mol%, and particularly preferably 62 mol% or more, based on all the structural units. The upper limit of the above content is not particularly limited and may be 100 mol% or less, 90 mol% or less, 80 mol% or less, 75 mol% or less, or 70 mol% or less, based on all the structural units.

[0021] Preferred examples of specific compounds constituting the (A) liquid crystalline resin applicable to the present invention include aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; aromatic diols such as 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcinol, compounds represented by the following general formula (I), and compounds represented by the following general formula (II); aromatic dicarboxylic acids such as 1,4-phenylenedicarboxylic acid, 1,3-phenylenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following general formula (III); and aromatic amines such as p-aminophenol, p-phenylenediamine, and N-acetyl-p-aminophenol. Of the aforementioned aromatic hydroxycarboxylic acids and their derivatives, 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, or combinations thereof are preferred from the viewpoint of reactivity and the stability of the molecular structure of the (A) liquid crystalline resin. [ka] (X: A group selected from alkylene (C1-C4), alkylidene, -O-, -SO-, -SO2-, -S-, and -CO-.) [ka] [ka] (Y:-(CH2) n -(n=1~4) and -O(CH2) n It is a base selected from O-(n=1~4).

[0022] The (A) liquid crystalline resin used in the present invention can be prepared by known methods using direct polymerization or transesterification from the above monomer compounds (or mixtures of monomers). Typically, melt polymerization, solution polymerization, slurry polymerization, solid-phase polymerization, etc., or a combination of two or more of these methods are used, with melt polymerization or a combination of melt polymerization and solid-phase polymerization being preferred. The above compounds having ester-forming ability may be used in polymerization in their original form, or they may be modified from precursors to derivatives having ester-forming ability in a step prior to polymerization. Various catalysts can be used in these polymerizations. Examples include metal salt catalysts such as fatty acid metal salt catalysts and organic compound catalysts. Typical examples 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. The amount of catalyst used is generally about 0.001 to 1% by mass, and particularly preferably about 0.01 to 0.2% by mass, relative to the total mass of the monomer. If necessary, the polymers produced by these polymerization methods can have their molecular weight increased by solid-phase polymerization, which involves heating under reduced pressure or in an inert gas.

[0023] (A) The melt viscosity of the liquid crystalline resin is not particularly limited. (A) A 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 of the (A) liquid crystalline resin in this specification is preferably 300 Pa·s or less, more preferably 5 to 150 Pa·s, and even more preferably 10 to 100 Pa·s. When the melt viscosity is within the above range, the (A) liquid crystalline resin itself, or a composition containing the (A) liquid crystalline resin, is more likely to have good film-forming properties during extrusion. In this specification, the melt viscosity of the liquid crystalline resin is measured in accordance with ISO 11443.

[0024] The content of (A) liquid crystalline resin in the total liquid crystalline resin composition for melt extrusion film of the present invention is preferably 85 to 99.5% by mass, more preferably 88 to 97% by mass, and even more preferably 90 to 95% by mass. A content of component (A) within the above range is preferable from the viewpoint of balancing film-forming properties and surface smoothness.

[0025] [(B) Mica] The liquid crystalline resin composition for melt extrusion films according to the present invention contains (B) mica. The inclusion of (B) mica in the liquid crystalline resin composition for melt extrusion films according to the present invention makes it easier to obtain films with excellent film-forming properties and surface smoothness. Surprisingly, the effect of easily obtaining films with excellent film-forming properties and surface smoothness is unique to (B) mica. Films obtained from liquid crystalline resin compositions containing other fillers instead of (B) mica tend to have excellent film-forming properties, but tend to have higher surface roughness and do not tend to have excellent surface smoothness. (B) mica can be used alone or in combination of two or more types.

[0026] (B) The average particle size of mica is preferably 50 μm or less. When the average particle size is within the above range, it is easy to obtain a film from the resulting composition that is well balanced in terms of film-forming properties and surface smoothness, while also being tear-resistant. The average particle size is more preferably 5 to 40 μm, and even more preferably 8 to 30 μm. In this specification, the average particle size of mica (B) refers to the volume-based arithmetic mean particle size measured by the laser diffraction / scattering particle size distribution method. The average particle size can be measured, for example, using the LA-920 laser diffraction / scattering particle size distribution analyzer manufactured by Horiba, Ltd. The average particle size of mica (B) in the liquid crystalline resin composition is measured by applying the above method to the remaining (B) component after ashing the liquid crystalline resin composition by heating it at 600°C for 2 hours.

[0027] The content of (B) mica in the total liquid crystalline resin composition for melt extrusion film of the present invention is 0.5 to 15% by mass. When the content of (B) mica is within the above range, it is easy to obtain a film from the resulting composition that has a good balance of film-forming properties and surface smoothness. The content of (B) mica is preferably 3 to 12% by mass, and more preferably 5 to 10% by mass.

[0028] Mica is a pulverized silicate mineral containing aluminum, potassium, magnesium, sodium, iron, etc. Examples of mica that can be used in this invention include muscovite, phlogopite, biotite, and artificial mica, but muscovite is preferred among these because it has a good hue and is inexpensive.

[0029] Furthermore, in the production of mica, wet grinding and dry grinding methods are known for grinding minerals. Wet grinding is a method in which the mica raw material is roughly ground in a dry grinder, then water is added to create a slurry, which is then ground in a wet grinding manner, followed by dewatering and drying. Compared to wet grinding, dry grinding is a low-cost and common method, but wet grinding makes it easier to grind minerals thinly and finely. In this invention, it is preferable to use thin and finely ground material because it yields mica having the preferred average particle size and the preferred thickness described later. Therefore, in this invention, it is preferable to use mica produced by wet grinding.

[0030] Furthermore, in the wet grinding method, a step is required to disperse the material to be ground in water. Therefore, to improve the dispersion efficiency of the material to be ground, it is common to add a flocculant and / or a settling aid to the material to be ground. Examples of flocculants and settling aids that can be used in the present invention include polyaluminum chloride, aluminum sulfate, ferrous sulfate, ferric sulfate, coppalus chloride, polyferrous sulfate, polyferric chloride, iron-silica inorganic polymer flocculant, ferric chloride-silica inorganic polymer flocculant, slaked lime (Ca(OH)2), caustic soda (NaOH), and soda ash (Na2CO3). These flocculants and settling aids have an alkaline or acidic pH. It is preferable that the mica used in the present invention is one that has not been treated with a flocculant and / or a settling aid during wet grinding. Using mica that has not been treated with a flocculant and / or a settling aid makes it less likely for the polymer in the liquid crystalline resin composition to decompose, reducing the generation of large amounts of gas and the molecular weight of the polymer, thus making it easier to maintain better performance of the resulting film.

[0031] The mica that can be used in the present invention may be surface-treated with a silane coupling agent or the like, and / or may be granulated with a binder to form granules.

[0032] [Other ingredients] The liquid crystalline resin composition for melt-extruded films of the present invention may also contain other polymers, fillers other than mica (granular fillers such as silica; plate-like fillers other than mica such as talc; fibrous fillers such as glass fibers; carbon black, etc.), and known substances generally added to synthetic resins, such as stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, etc., as appropriate according to the required performance, provided that the effects of the present invention are not impaired. From the viewpoint of surface smoothness, it is preferable that the liquid crystalline resin composition for melt-extruded films of the present invention does not contain fillers other than mica.

[0033] Other polymers include, for example, epoxy group-containing styrene polymers and epoxy group-free olefin polymers. Examples of epoxy group-containing styrene polymers include known epoxy group-containing styrene polymers, including copolymers composed of repeating units derived from styrenes and repeating units derived from glycidyl esters of α,β-unsaturated acids. Examples of epoxy group-free olefin polymers include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, polybutadiene, polyisoprene, polychloroprene, ethylene-propylene-butadiene copolymer, ethylene-propylene-isoprene copolymer, ethylene-propylene-chloroprene copolymer, ethylene-ethyl acrylate copolymer, and ethylene-vinyl acetate copolymer.

[0034] [Preparation of liquid crystalline resin compositions for melt-extruded films] The preparation of the liquid crystalline resin composition for melt-extruded films of the present invention is not particularly limited. For example, the liquid crystalline resin composition can be prepared by blending component (A), component (B), and optionally other components, and then melt-kneading them using a single-screw or twin-screw extruder.

[0035] [Liquid crystal resin composition for melt-extruded films] The melt viscosity of the liquid crystalline resin composition for melt extrusion film of the present invention obtained as described above is, from the viewpoint of film-forming properties, 80 Pa·s to 300 Pa·s, preferably 85 Pa·s to 275 Pa·s, more preferably 90 Pa·s to 250 Pa·s, and even more preferably 95 Pa·s to 225 Pa·s, at a temperature 10 to 30°C higher than the melting point of the liquid crystalline resin composition, a strain of 1%, and an angular frequency of 10 rad / s. In this specification, the melt viscosity of the liquid crystalline resin composition is the value obtained by a measurement method using a rotary rheometer in accordance with JIS K 7244-10:2005.

[0036] <film> The above-mentioned liquid crystalline resin composition is for melt-extruded films and is suitably used to manufacture films. That is, a melt-extruded film can be manufactured using the above-mentioned liquid crystalline resin composition. The film according to the present invention contains the liquid crystalline resin composition for melt-extruded films according to the present invention. The film according to the present invention is not particularly limited, and examples include melt-extruded films.

[0037] The film according to the present invention is not particularly limited in its use and can be used in various fields, for example, as an industrial film such as an insulating film, a waterproof film, or a heat-resistant film, or as a packaging material film such as a gas barrier film.

[0038] The thickness of the film according to the present invention is not particularly limited as long as it is within a range suitable for the film's application. From the viewpoint of applications such as insulating films, 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. Furthermore, the film thickness may be 20 μm, 100 μm, 200 μm, 20 μm to 100 μm, or 100 μm to 200 μm.

[0039] The surface roughness (Wc) of the film according to the present invention is preferably 10 or less, more preferably 8 or less, and even more preferably 7 or less. The lower limit of the surface roughness (Wc) is not particularly limited and may be 0 or more, 1 or more, or 2 or more. In this specification, the surface roughness (Wc) is defined as the value obtained by measurement with a surface roughness measuring instrument in accordance with JIS B 0601-2001. The surface roughness (Wc) of the film can be adjusted as appropriate by varying the content of (B) mica, the film formation temperature, etc.

[0040] [Film manufacturing method] The film in the present invention can be manufactured as a molten extruded film by, for example, melting a liquid crystalline resin composition in a single-screw extruder, discharging the molten resin composition from the extruder and supplying it to a die, and then extruding the molten resin composition from the die in a sheet form and cooling and solidifying it. The liquid crystalline resin composition melted in the extruder is discharged from the die in a sheet form and is cast, for example, on a rotating cooling drum to cool and solidify rapidly, thereby obtaining a molten extruded film. After cooling and solidification, this molten extruded film may be subjected to longitudinal and transverse stretching in order as appropriate, and finally, it may be wound into a roll form.

[0041] The extruder described above is a single-screw type extruder, equipped with a single-screw cylinder. The cylinder has a supply port, and the liquid crystalline resin composition is supplied into the cylinder through the supply port. The inside of the cylinder is composed of, in order from the supply port side, a supply section that quantitatively transports the liquid crystalline resin composition supplied from the supply port, a compression section that kneads and compresses the liquid crystalline resin composition, and a transport and metering section that transports the kneaded and compressed liquid crystalline resin composition to the discharge port while measuring the discharge amount.

[0042] The screw compression ratio of the extruder is set to, for example, 2.5 to 5.0, and the L / D ratio is set to, for example, 18 to 45. Here, the screw compression ratio refers to the degree to which the liquid crystalline resin composition is compressed in a molten state in order to knead it under back pressure, and is expressed as the volume ratio of the supply section and the conveying and metering section (i.e., volume per unit length of the supply section / 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. L / D is the ratio of the cylinder length (L) to the cylinder inner diameter (D).

[0043] When the screw compression ratio is 2.5 or higher, the mixture is easily kneaded, and it is less likely that undissolved portions will occur or that shear heat generation will be small, resulting in insufficient melting of the crystals. Conversely, when the screw compression ratio is 5.0 or lower, excessive shear stress is not applied, and it is less likely that the liquid crystalline resin composition will deteriorate due to heat generation or that the molecular weight will decrease due to the severance of liquid crystalline resin molecules. As a result, the molten resin composition is less likely to be non-uniform. The screw compression ratio is preferably in the range of 2.6 to 4.0, more preferably in the range of 2.7 to 3.5, and particularly preferably in the range of 2.8 to 3.0.

[0044] When the L / D ratio is 18 or higher, insufficient melting or mixing is less likely to occur, and fine crystals are less likely to remain, similar to when the screw compression ratio is 2.5 or higher. Conversely, when the L / D ratio is 45 or lower, the residence time of the liquid crystalline resin in the extruder is less likely to be long, and resin degradation is less likely to occur. Also, when the residence time is less long, cleavage of liquid crystalline resin molecules is less likely to occur, and the molecular weight does not decrease easily. The L / D ratio is good in the range of 21 to 40, preferably in the range of 25 to 35, and particularly preferably in the range of 28 to 30.

[0045] The liquid crystalline resin composition is melted by the extruder configured as described above, and the molten resin composition is continuously fed from the discharge port to the die. The molten resin composition fed to the die by the extruder is then extruded from the die in a sheet form, and is cast, for example, onto a cooling drum to cool and solidify, thereby forming a molten extruded film. Here, it is preferable that the melting point Tm (°C) of the liquid crystalline resin composition and the die set temperature Td (°C) satisfy Tm-10 ≤ Td ≤ Tm+15. If Tm-10 ≤ Td, the molten extruded film is less likely to produce blemishes (i.e., particles mixed in the molten extruded film). If Td ≤ Tm+15, the molten extruded film tends to have good surface smoothness. Tm (°C) and Td (°C) preferably satisfy Tm-9 ≤ Td ≤ Tm+14, more preferably Tm-8 ≤ Td ≤ Tm+13. [Examples]

[0046] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0047] <Liquid crystal resin> Aromatic polyester After loading the following raw materials into the polymerization vessel, the reaction system temperature was raised to 140°C and the reaction was carried out at 140°C for 1 hour. Then, the temperature was further increased to 325°C over 3.5 hours, and from there, the pressure was reduced to 5 Torr (i.e., 667 Pa) over 20 minutes, allowing melt polymerization to be carried out 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 change the pressure from reduced to atmospheric pressure and then to a pressurized state. The polymer was discharged from the bottom of the polymerization vessel and pelletized using the strand-cut method to obtain the target polymer as pellets. The melting point of the obtained polymer was 280°C, and the melt viscosity at 300°C was 44 Pa·s. The melt viscosity of the above polymer was measured in the same manner as the melt viscosity measurement method described later. 6-Hydroxy-2-naphthoic acid (HNA); 837g (27 mol%) 4-Hydroxybenzoic acid (HBA); 1660g (73 mol%) Fatty acid metal salt catalyst (potassium acetate catalyst); 165 mg Acylating agent (acetic anhydride); 1714g

[0048] • Aromatic polyesteramide After loading the following raw materials into the polymerization vessel, the reaction system temperature was raised to 140°C and the reaction was carried out at 140°C for 1 hour. Then, the temperature was further increased to 340°C over 4.5 hours, and from there, the pressure was reduced to 10 Torr (i.e., 1330 Pa) over 15 minutes, allowing melt polymerization to be carried out 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 change the pressure from reduced to atmospheric pressure and then to a pressurized state, allowing the polymer to be discharged from the bottom of the polymerization vessel. The strands were then pelletized to obtain pellets. The obtained pellets were heat-treated at 300°C for 2 hours under a nitrogen atmosphere to obtain the target polymer. The melting point of the obtained polymer was 335°C, and the melt viscosity at 350°C was 19.0 Pa·s. The melt viscosity of the above polymer was measured in the same manner as the melt viscosity measurement method described later. 4-Hydroxybenzoic acid (HBA); 1380g (60 mol%) 6-Hydroxy-2-naphthoic acid (HNA); 157g (5 mol%) 1,4-Phenylenedicarboxylic acid (TA); 484g (17.5 mol%) 4,4'-Dihydroxybiphenyl (BP); 388g (12.5 mol%) N-acetyl-p-aminophenol (APAP); 126g (5 mol%) Fatty acid metal salt catalyst (potassium acetate catalyst); 110 mg Acylating agent (acetic anhydride); 1659g

[0049] <Melting point> Using a differential scanning calorimeter (DSC, manufactured by Hitachi High-Tech Science Corporation), the endothermic peak temperature (Tm1) observed when the obtained liquid crystalline resin pellet was heated from room temperature at a heating rate of 20°C / min was measured. The pellet was then held at (Tm1+40)°C for 2 minutes. Furthermore, after cooling to room temperature at a cooling rate of 20°C / min, the endothermic peak temperature (Tm2) observed when the pellet was heated again at a heating rate of 20°C / min was measured as the melting point.

[0050] <Melting viscosity> Using a Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd., and at the following temperatures, an orifice with an inner diameter of 1 mm and a length of 20 mm was used, with a shear rate of 1000 sec. -1 Then, in accordance with ISO 11443, the melt viscosity of the liquid crystalline resin was measured. Aromatic polyester: 300℃ Aromatic polyesteramide: 350℃

[0051] <Materials other than liquid crystalline resins> • Mica 1: Y-1800 (manufactured by Yamaguchi Mica Co., Ltd., mica, average particle size 10.8 μm) • Mica 2: AB-25S (manufactured by Yamaguchi Mica Co., Ltd., mica, average particle size 24.0 μm) • Talc: Crown Talc PP (manufactured by Matsumura Sangyo Co., Ltd., talc, average particle size 12.8 μm) • Silica: Denka Fused Silica FB-5SDC (manufactured by Denka Co., Ltd., silica, average particle size 4.8 μm)

[0052] <Manufacturing of liquid crystalline resin compositions> The above components were melt-kneaded in the proportions shown in Table 1 using a twin-screw extruder (TEX30α type, manufactured by Japan Steel Works Ltd.) at the cylinder temperatures listed below to obtain liquid crystalline resin composition pellets. [Manufacturing conditions] Cylinder temperature: 300℃ (Example 1 and Comparative Examples 1 and 2) 350℃ (Examples 2-5 and Comparative Examples 3-5)

[0053] <Melting point> The melting point of the liquid crystalline resin composition was measured in the same manner as described above, except that liquid crystalline resin composition pellets were used instead of liquid crystalline resin pellets. The results are shown in Table 1.

[0054] <Melting viscosity> Using a rotary rheometer (TA Instruments, DHR-3), the melt viscosity of liquid crystalline resin composition pellets was measured under a nitrogen atmosphere in accordance with JIS K 7244-10:2005. The specific measurement temperature and other conditions were as follows. The results are shown in Table 1. Plate: 25mm diameter parallel plate Clearance: 1000 μm Distortion level: 1% Melt viscosity: Values ​​at 300°C and an angular frequency of 10 rad / s (Example 1 and Comparative Examples 1 and 2) Values ​​at 350°C and an angular frequency of 10 rad / s (Examples 2-5 and Comparative Examples 3-5)

[0055] <Manufacturing of molten extruded films> Using the obtained liquid crystalline resin pellets as raw material, a single-screw extruder (20mmφ single-screw extruder "Laboplastmill" manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to melt the material under the following conditions, with the screw compression ratio set to 2.9 and L / D = 29. The material was then extruded into a film from the T-die at the tip of the extruder (a coat hanger die with a width of 150mm) with the die temperature set to the melting point of the liquid crystalline resin composition + 10°C. The film was then cooled, and the winding speed was adjusted to produce a molten extruded film with a thickness of 100 μm. Cylinder temperature: Same as die temperature setting Screw rotation speed: 35 rpm Discharge amount: 30kg / h

[0056] <Surface roughness (Wc)> The surface roughness (Wc) of the melt-extruded films prepared as described above was measured using a CNC surface roughness measuring instrument (SURFTEST Extreme SV-3000 CNC, manufactured by Mitutoyo Corporation). Specifically, melt-extruded films cut to a size of 60 mm × 15 mm × 100 μm were measured in accordance with JIS B 0601-2001. The results are shown in Table 1. In Comparative Examples 4 and 5, the number of holes described later was too large, making it impossible to measure the surface roughness (Wc).

[0057] <Film forming properties> A 100cm melt-extruded film prepared as described above. 2 The number of holes per sample was visually counted, and the film-forming properties were evaluated according to the following criteria. The results are shown in Table 1. ○ (Good): The number of holes was 0. △ (Slightly defective): The number of holes was between 1 and 4. × (Defective): The number of holes was 5 or more.

[0058] [Table 1]

[0059] As is clear from the results shown in Table 1, the liquid crystalline resin compositions of the examples were confirmed to be able to provide films with a good balance of film-forming properties and surface smoothness.

Claims

1. (A) Liquid crystal resin, and (B) Mica A liquid crystalline resin composition for melt extrusion film containing, A liquid crystalline resin composition for melt extrusion film, wherein the content of (B) mica is 0.5 to 15% by mass relative to the entire liquid crystalline resin composition.

2. The liquid crystalline resin composition for melt extruded films according to claim 1, wherein the (A) liquid crystalline resin is an aromatic polyester or aromatic polyesteramide comprising at least one structural unit selected from the group consisting of aromatic hydroxycarboxylic acids and their derivatives.

3. The liquid crystalline resin composition for melt extruded film according to claim 1 or 2, wherein the average particle size of the mica (B) is 50 μm or less.

4. The liquid crystalline resin composition for melt extrusion film according to claim 1 or 2, wherein the melt viscosity of the liquid crystalline resin composition at a temperature 10 to 30°C higher than the melting point of the liquid crystalline resin composition, a strain of 1%, and an angular frequency of 10 rad / s is 80 Pa·s or more and 300 Pa·s or less.

5. Use of the liquid crystalline resin composition for melt extrusion film according to claim 1 or 2 for manufacturing a film.

6. A film comprising the liquid crystalline resin composition for melt extrusion film according to claim 1 or 2.

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