TWI754049B - Liquid crystal polyester composition - Google Patents

Abstract

A liquid crystal polyester composition including a liquid crystal polyester and a glass fiber and satisfying the following (i) and (ii): (i) the flow initiation temperature of the liquid crystal polyester composition is 330℃ or more; and (ii) when, in the chromatogram of the decomposition product obtained by decomposing the liquid crystal polyester composition with n-butylaminethe the area ratio of the peak area at the retention time of 21.90 minutes to the peal area at the retention time of 2.50 minutes is a and, in a chromatogram of a decomposition product obtained by decomposition the liquid crystal polyester composition maintained at a temperature 30℃ higher than the flow initiation temperature of the liquid crystal polyester composition for 1 hour with n-butylamine, the area ratio of the peak area at the retention time of 21.90 minutes to the peak area at the retention time of 2.50 minutes is b, the value of 100 ×b/a is 50 or more and 200 or less.

Description

Liquid crystal polyester composition

The present invention relates to liquid crystal polyester compositions.

In this case, priority is claimed based on Japanese Patent Application No. 2017-090719 filed in Japan on April 28, 2017, and the content thereof is incorporated herein by reference.

Liquid crystal polyesters are widely used mainly for electrical and electronic parts because they are excellent in heat resistance, fluidity, and dimensional stability. In order to meet these uses, there has been proposed a molded body using a liquid crystal polyester composition using a liquid crystal polyester with high heat resistance and glass fiber as a forming material (for example, Patent Document 1).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-239950

However, in the conventional technology, although the heat resistance of the liquid crystal polyester composition is high, there is a problem that the thin-walled fluidity is low.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid crystal polyester composition having high heat resistance and high thin-wall fluidity.

In order to solve the above-mentioned problems, the present invention includes the following aspects: [1] A liquid crystal polyester composition comprising liquid crystal polyester and glass fibers; wherein the liquid crystal polyester composition satisfies the following (i) and (ii) Conditions: (i) the flow initiation temperature of the liquid crystal polyester composition is above 330°C; (ii) the liquid crystal polyester contained in the liquid crystal polyester composition is decomposed by n-butylamine to obtain the liquid crystal After the decomposition product of the polyester composition (that is, the decomposition product of the liquid crystal polyester composition treated with n-butylamine), the decomposition product was measured by liquid chromatography under the following conditions. In the obtained chromatogram, the area ratio of the "peak area with a retention time of 21.90 minutes" to the "peak area with a retention time of 2.50 minutes" was defined as a; The chromatogram of the liquid-crystalline polyester composition obtained by the same method as above (that is, the liquid-crystalline polyester composition obtained by n-butylamine at a higher temperature than the above-mentioned liquid-crystalline polyester by n-butylamine) After the liquid crystal polyester composition was decomposed and obtained by maintaining the liquid crystal polyester composition at a temperature higher than 30°C for 1 hour, the flow initiation temperature of the composition was measured by liquid chromatography under the following conditions. In the chromatogram), the area ratio of the "peak area with a retention time of 21.90 minutes" to the "peak area with a residence time of 2.50 minutes" is set as b; at this time, the value of 100×b/a is 50 Above 200 below.

[condition]

Sample injection volume: 10 μL

×1250mm) Column: manufactured by Sumika Analysis Center Co., Ltd., product name "sumipax ODS KP-06" (5μm × 4.6mm

×1250mm)

Column temperature: 40℃

Determination method: gradient elution method

Elution flow rate: 1.0mL/min

Detector: Ultraviolet Visible Spectrophotometer (UV)

Detection wavelength: 240nm

Eluent: Using (A) an aqueous solution added with 0.1% acetic acid and (B) an acetonitrile solution added with 0.1% acetic acid, the composition of the eluent was changed according to the following gradient conditions.

[gradient condition]

First, the ratio of the solution (B) was linearly changed from 10 vol % to 15 vol % with respect to the entire amount of the elution solution over a period of 15 minutes. Then, the ratio of the solution (B) was linearly changed from 15% by volume to 100% by volume with respect to the entire amount of the elution solution over 10 minutes.

The liquid crystal polyester composition of one aspect of the present invention has high heat resistance and high thin-wall fluidity.

1‧‧‧Motor

1a‧‧‧motor box

2‧‧‧Cylinder block

3‧‧‧Screw

4‧‧‧First vent hole

5‧‧‧Main inlet

6‧‧‧Second vent hole

7‧‧‧Side inlet

8‧‧‧Delivery

9‧‧‧Spit out the mold

9a‧‧‧Nozzle hole

10‧‧‧Extruder

11‧‧‧The first mixing department

12‧‧‧Second Mixing Department

13‧‧‧The third mixing department

Fig. 1 is a schematic cross-sectional view showing an example of an extruder related to a method for producing a liquid crystal polyester composition according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the structure of the thin-walled flow length measurement mold of the present embodiment.

The liquid crystal polyester composition according to one embodiment of the present invention will be described below with reference to the drawings. In addition, in all the drawings below, the dimensions, ratios, and the like of each constituent element are appropriately changed in order to make the drawings easier to see.

<Liquid crystal polyester composition>

The liquid crystal polyester composition of the present invention comprises liquid crystal polyester and glass fiber.

[liquid crystal polyester]

The liquid crystal polyester of the present embodiment exhibits liquid crystallinity in a molten state. The aforementioned liquid crystal polyester may be liquid crystal polyester imide, liquid crystal polyester ether, liquid crystal polyester carbonate, or liquid crystal polyester imide.

The flow initiation temperature of the liquid crystal polyester of the present embodiment is preferably 330°C or higher. It is preferably 330°C or higher and 450°C or lower, more preferably 330°C or higher and 400°C or lower, and still more preferably 330°C or higher and 390°C or lower. In addition, the flow initiation temperature may be 340°C or higher, 350°C or higher, or 360°C or higher.

On the other hand, the flow initiation temperature may be 340°C or higher and 450°C or lower, 350°C or higher and 400°C or lower, or 360°C or higher and 390°C or lower.

The so-called flow initiation temperature was measured by using a capillary rheometer under a load of 9.8 MPa (100 kg/cm ² ) at a rate of 4° C./min while melting the liquid crystal polyester. The temperature at which a viscosity of 4800Pa·s (48000 poise) is displayed when extruding from a nozzle of 1mm and a length of 10mm. This is a reference for the molecular weight of liquid crystal polyesters (see Naoyuki Koide, "Liquid Crystal Polymers-Synthesis/Forming/Application-", CMC Co., Ltd., June 5, 1987, p.95).

The liquid crystal polyester of the present embodiment includes a structural unit derived from p-hydroxybenzoic acid. Furthermore, the liquid crystal polyester of the present embodiment is preferably a wholly aromatic liquid crystal polyester polymerized only from an aromatic compound as a raw material monomer.

Typical examples of liquid crystal polyesters include "at least one compound selected from the group consisting of aromatic diols, aromatic hydroxyamines, and aromatic diamines" and aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids. Those obtained by polymerization (polycondensation); those obtained by polymerizing a plurality of aromatic hydroxycarboxylic acids; "at least one compound selected from the group consisting of aromatic hydroxyamines and aromatic diamines" and aromatic A product obtained by polymerizing a dicarboxylic acid and an aromatic diol; and a product obtained by polymerizing a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid.

Among them, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines and aromatic diamines may be independently used to replace a part or all of them with their polymerizable derivatives.

Examples of polymerizable derivatives of compounds having a carboxyl group such as aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids include: those in which the carboxyl group is substituted by an alkoxycarbonyl group or an aryloxycarbonyl group (ie, ester), the carboxyl group is substituted by a halogenated Substituted carboxyl group (ie acid halide), and carboxyl group substituted with acyloxycarbonyl group (ie acid anhydride).

Examples of polymerizable derivatives of compounds having hydroxyl groups such as aromatic hydroxycarboxylic acids, aromatic diols, and aromatic hydroxylamines include those in which hydroxyl groups are alkylated and substituted with alkoxyl groups (that is, hydroxyl groups). of acyl compounds).

As examples of the polymerizable derivatives of compounds having an amine group such as aromatic hydroxyamine and aromatic diamine, there may be mentioned: those obtained by amide group substituted with an amide group (that is, an amide group of an amine group) ).

The liquid crystal polyester preferably has a repeating unit represented by the following formula (1) (hereinafter also referred to as "repeating unit (1)"), and preferably has a repeating unit (1) and the following formula (2) The repeating unit (hereinafter also referred to as "repeating unit (2)") and the repeating unit represented by the following formula (3) (hereinafter also referred to as "repeating unit (3)") are more preferable.

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-X-Ar ³ -Y-

In the above formulae (1) to (3), Ar ¹ represents a phenylene group, a naphthylene group or a biphenylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylene group, or a group represented by the following formula (4). X and Y each independently represent an oxygen atom or an imino group (-NH-). The hydrogen atom contained in the aforementioned groups represented by Ar ¹ , Ar ² or Ar ³ may be independently substituted with a halogen atom, an alkyl group or an aryl group, respectively.

(4)-Ar ⁴ -Z-Ar ⁵ -

In formula (4), Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylene group.

The hydrogen atom contained in the aforementioned group represented by Ar ⁴ or Ar ⁵ may be independently substituted with a halogen atom, an alkyl group or an aryl group.

Examples of the halogen atom that can replace the hydrogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The aforementioned alkyl group that can replace the hydrogen atom is preferably an alkyl group having 1 to 10 carbon atoms, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary Butyl, tertiary butyl, n-hexyl, 2-ethylhexyl, n-octyl and n-decyl.

As for the aforementioned aryl group that can replace a hydrogen atom, at least one hydrogen atom constituting the aforementioned aryl group may be substituted, and an aryl group having a total carbon number of 6 to 20 including the aforementioned substituent group is preferred, for example: Phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl and 2-naphthyl.

When the aforementioned hydrogen atoms contained in the aforementioned groups represented by Ar ¹ , Ar ² or Ar ³ are substituted with these groups, in terms of the number of substitutions, the aforementioned groups represented by each of Ar ¹ , Ar ² or Ar ³ are The number of middle lines is usually two or less, preferably one, independently of each other.

The aforementioned alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, and examples thereof include methylene, ethylene, isopropylene, n-butylene, and 2-ethylhexylene.

When the hydrogen atom contained in the group represented by Ar ⁴ or Ar ⁵ is substituted with the aforementioned halogen atom, the aforementioned alkyl group or the aforementioned aryl group, in terms of the number of the groups substituted for the hydrogen atom, the number of hydrogen atoms in each Ar ⁴ or Ar ⁵ The number of bases shown independently of each other is preferably two or less, more preferably one.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. Repeating units (1) are those with Ar ¹ as a p-phenylene group (such as a repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ as a 2,6-naphthylene group (such as derived from 6-hydroxy- 2-naphthoic acid repeating unit) is preferred.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. The repeating units (2) are those with Ar ² as a p-phenylene group (such as a repeating unit derived from terephthalic acid), and Ar ² as a m-phenylene group (such as a repeating unit derived from isophthalic acid) , Ar ² is a 2,6-naphthylene group (such as a repeating unit derived from 2,6-naphthalenedicarboxylic acid), and Ar ² is a diphenyl ether-4,4'-diyl (such as a source of Repeating units derived from diphenyl ether-4,4'-dicarboxylic acid) are preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. The repeating units (3) are those with Ar ³ as a p-phenylene (such as a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ as a 4,4'-biphenylene Groups (such as repeating units derived from 4,4'-dihydroxybiphenyl, 4-amino-4'-hydroxybiphenyl or 4,4'-diaminobiphenyl) are preferred.

The term "derived from" in this specification means that the chemical structure is changed due to the polymerization.

The content of the repeating unit (1) in the liquid crystal polyester is usually 30 mol % or more, preferably 30 to 80 mol %, more preferably 40 mol % relative to the total amount of all repeating units constituting the liquid crystal polyester. to 70 mol %, more preferably 45 to 65 mol %.

The total amount of all repeating units constituting the liquid crystal polyester means that the substance of each repeating unit is obtained by dividing "the mass of each repeating unit constituting the liquid crystal polyester" by "the formula weight of each repeating unit thereof" Equivalent (moles) and summed values. The mass of each repeating unit constituting the liquid crystal polyester is calculated from the usage amount of the raw material monomers to be used, and this is a numerical value assuming that all the raw material monomers are reacted.

Similarly, the content of the repeating unit (2) of the liquid crystal polyester is 35 mol % or less, preferably 10 to 35 mol %, more preferably 10 to 35 mol % relative to the total amount of all repeating units constituting the liquid crystal polyester. 15 to 30 mol %, more preferably 17.5 to 27.5 mol %.

The content rate of the repeating unit (3) of the liquid crystal polyester is 35 mol % or less, preferably 10 to 35 mol %, more preferably 15 to 30 mol % with respect to the total amount of all repeating units constituting the liquid crystal polyester. mol %, more preferably 17.5 to 27.5 mol %.

On the one hand, when the liquid crystalline polyester includes the repeating unit (1), the repeating unit (2) and the repeating unit (3), the repeating unit (1) is the total amount of all repeating units constituting the aforementioned liquid crystal polyester. The content rate is 30 to 80 mol%, preferably 40 to 70 mol%, more preferably 45 to 65 mol%; the content of the repeating unit (2) is 10 to 35 mol%, preferably 15 to 30 mol %, more preferably 17.5 to 27.5 mol %; the content of the repeating unit (3) is 10 to 35 mol %, preferably 15 to 30 mol %, more preferably 17.5 to 27.5 mol % Ear%. However, the total content of repeating unit (1), repeating unit (2) and repeating unit (3) does not exceed 100 mol%.

In the liquid crystal polyester, the higher the content of the repeating unit (1), the easier it is to improve melt fluidity, heat resistance, and strength/rigidity. However, when the content rate of the repeating unit (1) is higher than 80 mol %, the melting temperature and the melt viscosity tend to be high, and the temperature required for molding tends to be high.

In the liquid crystal polyester of the present embodiment, the ratio of the content of the repeating unit (2) to the content of the repeating unit (3) is determined by [the content of the repeating unit (2)]/[the content of the repeating unit (3) ] (mol%/mol%). The ratio of the content rate of the repeating unit (2) to the content rate of the repeating unit (3) is usually 0.9 to 1.11, preferably 0.95 to 1.05, more preferably 0.98 to 1.02.

In addition, the repeating units (1) to (3) which the liquid crystal polyester has may each independently be derived from one kind of raw material monomer, or may be derived from two or more kinds of raw material monomers. Furthermore, the liquid crystal polyester may have repeating units other than repeating units (1) to (3). The content of repeating units other than repeating units (1) to (3) is 0 mol % or more and 10 mol % or less, preferably 5 mol % with respect to the total amount of all repeating units constituting the liquid crystal polyester. the following.

On the other hand, with respect to the total content rate of all repeating units constituting the liquid crystal polyester, the liquid crystal polyester of the present invention is grouped by repeating unit (1), repeating unit (2) and repeating unit (3) The content of at least one repeating unit selected from the group is preferably 90 mol% or more and 100 mol% or less, more preferably 95 mol% or more and 100 mol% or less.

The liquid crystalline polyester preferably has, as repeating units (3), those in which X and Y are oxygen atoms, respectively. That is, if it has a repeating unit derived from a predetermined aromatic diol, since melt viscosity tends to become low, it is preferable. Moreover, it is more preferable to have only what X and Y are oxygen atoms, respectively, as a repeating unit (3).

Liquid crystal polyesters may be used in combination with those having the same repeating unit in the above-mentioned range and having different content of the repeating unit.

The liquid crystal polyester in the liquid crystal polyester composition of the present embodiment may be a commercially available one, one manufactured by a known manufacturing method, or one manufactured by a known manufacturing method, as described in the description of the manufacturing method of the liquid crystal polyester composition described later. It is synthesized from raw material monomers corresponding to "repeating units constituting liquid crystal polyester".

In the liquid crystal polyester composition of the present embodiment, the content of the liquid crystal polyester is preferably 40 to 80% by mass relative to the total mass of the liquid crystal polyester composition.

[glass fiber]

The lower limit of the number average fiber length of the glass fibers contained in the liquid crystal polyester composition of the present embodiment is preferably 30 μm or more, more preferably 50 μm or more, still more preferably 70 μm or more, particularly preferably 80 μm or more.

Furthermore, the upper limit of the number average fiber length of the glass fibers contained in the liquid crystal polyester composition is preferably 200 μm or less, more preferably 170 μm or less, still more preferably 150 μm or less, and particularly preferably 100 μm or less.

The above upper limit value and lower limit value can be arbitrarily combined.

On the one hand, the number-average fiber length of the glass fibers contained in the liquid crystal polyester composition is preferably 30 μm or more and 200 μm or less, more preferably 50 μm or more and 170 μm or less, still more preferably 70 μm or more and 150 μm or less, particularly preferably 80 μm or more and 100 μm or less.

In the present embodiment, the number-average fiber length of the glass fibers in the liquid crystal polyester composition is measured by the method shown below. First, a predetermined amount of pellets composed of the liquid crystalline polyester composition was taken into a crucible, and was treated in an electric furnace at 600° C. for 6 hours to be ashed. Next, the obtained residue was dispersed in methanol, and a microscope photograph (magnification: 100 times) was taken in a state of being spread on a glass slide. The number-average fiber length of the glass fibers in the liquid crystal polyester composition was obtained by directly reading the length of the glass fibers from the photograph and calculating the average value.

In addition, the fiber length here means the maximum length of the fiber.

The average fiber diameter of the glass fibers is not particularly limited, but is preferably 3 μm or more and 15 μm or less. By setting the average fiber diameter of the glass fibers to be 3 μm or more, the reinforcing effect of the molded body formed from the obtained liquid crystal polyester composition can be made more sufficient. Furthermore, by making the average fiber diameter of the glass fibers 15 μm or less, the moldability of the obtained liquid crystal polyester composition is improved, and the appearance of the surface of the molded body formed from the liquid crystal polyester composition is improved.

The average fiber diameter of glass fibers can be calculated, for example, by reading directly from a microscope photograph.

The surface of the glass fiber of this embodiment can be treated with a surface coating agent. The surface coating agent includes coupling agents such as titanium coupling agents, resins, and other surface coating agents generally used for surface coating.

The use of the glass fiber treated with the surface coating agent can suppress the generation of gas in the molded body formed from the obtained liquid crystal polyester composition. Therefore, the chemical stability of the molded body can be improved. Furthermore, when assembling electrical and electronic equipment or optical equipment, it is possible to reduce contamination of peripheral members caused by gas generated from the molded body.

The glass fiber of the present embodiment can be treated with an epoxy-based, urethane-based, acrylic-based coating agent or a sizing agent.

In the liquid crystal polyester composition of the present embodiment, the content of glass fibers is preferably 20 to 60 mass % with respect to the total mass of the liquid crystal polyester composition.

[other ingredients]

The liquid crystal polyester composition according to one embodiment of the present invention may contain at least one of "other components such as fillers other than glass fibers, additives, and resins other than liquid crystal polyester" as needed.

From one aspect, the liquid crystal polyester composition of the present invention comprises: liquid crystal polyester; glass fiber; Select at least one ingredient.

In the liquid crystal polyester composition of the present invention, the content of other components is preferably 30% by mass or less with respect to the total mass of the liquid crystal polyester composition.

Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants, and colorants. The content of the additive in the liquid crystal polyester composition is usually 0 to 5 parts by mass relative to 100 parts by mass of the liquid crystal polyester.

Examples of resins other than liquid crystal polyester include polypropylene, polyamide, polyester other than liquid crystal polyester, polysiloxane, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyether amide Thermoplastic resins other than liquid crystal polyesters such as amines; and thermosetting resins such as phenol resins, epoxy resins, polyimide resins, and cyanate resins. The content of resins other than the liquid crystal polyester in the liquid crystal polyester composition is usually 0 to 20 parts by mass relative to 100 parts by mass of the liquid crystal polyester.

[Liquid crystal polyester composition]

The flow initiation temperature of the liquid crystal polyester composition of the present embodiment is 330° C. or higher and 450° C. or lower, which is quite high. The higher the flow initiation temperature of the liquid crystal polyester composition, the easier it is to improve heat resistance and strength/rigidity. That is, the liquid crystal polyester composition of the present embodiment having a flow initiation temperature of 330° C. or higher tends to improve heat resistance easily.

In the liquid crystal polyester composition of the present embodiment, the value of 100×b/a calculated from the peak area ratio a and the peak area ratio b in the chromatogram of the liquid crystal polyester composition (hereinafter also referred to as an element) (ii)) 50 or more and 200 or less.

The peak area ratio a and the peak area ratio b described above are measured by the following methods. The liquid crystal polyester contained in the liquid crystal polyester composition is decomposed by n-butylamine to obtain a decomposed product (that is, the liquid crystal polyester composition is treated with n-butylamine to obtain a decomposed product). In the chromatogram obtained by measuring the decomposed product by liquid chromatography under the following conditions, the "peak area at a retention time of 21.90 minutes" was calculated as the difference between the "peak area at a retention time of 2.50 minutes". Area ratio as a. Furthermore, in the chromatogram obtained by the same method as above, the liquid crystal polyester composition after being kept at a temperature 30°C higher than the flow initiation temperature of the liquid crystal polyester composition for 1 hour, was "retained". The area ratio of the "peak area at a time of 21.90 minutes" to the "peak area at a retention time of 2.50 minutes" is referred to as b.

[condition]

Sample injection volume: 10 μL

×1250mm) Column: manufactured by Sumika Analysis Center Co., Ltd., product name "sumipax ODS KP-06" (5μm × 4.6mm

×1250mm)

Column temperature: 40℃

Determination method: gradient elution method

Elution flow rate: 1.0mL/min

Detector: Ultraviolet Visible Spectrophotometer (UV)

Detection wavelength: 240nm

Eluent: Using (A) an aqueous solution added with 0.1% acetic acid and (B) an acetonitrile solution added with 0.1% acetic acid, the composition of the eluent was changed according to the following gradient conditions.

[gradient condition]

First, the ratio of the solution (B) was linearly changed from 10% by volume to 15% by volume with respect to the total amount of the eluent over 15 minutes. Then, the ratio of the solution (B) was linearly changed from 15% by volume to 100% by volume with respect to the entire amount of the elution solution over 10 minutes.

Here, the element (ii) will be described in detail.

In this embodiment, before the liquid crystalline polyester composition is measured by liquid chromatography, n-butylamine is added to the liquid crystalline polyester composition, and the liquid crystalline polyester contained in the liquid crystalline polyester composition is Treatment with butylamine. Thereby, the ester bond between the repeating units which comprise "the liquid crystal polyester contained in a liquid crystal polyester composition" is decomposed, and the said liquid crystal polyester can be decomposed|disassembled. In the chromatogram of the decomposed product of the liquid crystal polyester (that is, the decomposed product of the n-butylamine-treated liquid crystal polyester composition), components derived from each repeating unit are detected as peaks.

The chromatogram of the decomposition product of the liquid crystal polyester (that is, the decomposition product of the liquid crystal polyester composition treated with n-butylamine), after the liquid crystal polyester composition is decomposed by n-butylamine, according to the above It was obtained by measuring the conditions by liquid chromatography.

Among them, N-n-butyl-p-hydroxybenzamide, which is one of the "decomposition products of liquid crystal polyester", was detected at the peak position of the retention time of 2.50 minutes. In addition, another decomposition product (hereinafter also referred to as component X) was detected at the peak position of the retention time of 21.90 minutes.

Among them, it is assumed that the component X detected at the peak position of the retention time of 21.90 minutes is derived from the "crosslinking component resulting from the crosslinking of the liquid crystal polyester".

In this specification, the element (ii) means the rate of change of the component X of the crosslinking component when the liquid crystal polyester composition is kept at a temperature 30°C higher than the flow initiation temperature thereof. When the value (100×b/a) of the element (ii) is 50 or more and 200 or less, it can be said that when the liquid crystal polyester composition is maintained under the above conditions, the component X is less likely to be generated and the structural change is small. That is, the liquid crystal polyester composition of the present embodiment can be said to be the one with less structural change when kept under the above-mentioned conditions.

The value (100×b/a) of the element (ii) is preferably 60 or more, more preferably 70 or more. Furthermore, the value of the element (ii) is preferably 150 or less, more preferably 120 or less.

On the one hand, the value (100×b/a) of the element (ii) is preferably 60 or more and 150 or less, more preferably 70 or more and 120 or less, and particularly preferably 70 or more and 80 or less.

In the liquid crystal polyester composition of the present embodiment, since the value of the element (ii) (100×b/a) is 50 or more and 200 or less, it can be said that it is kept at a temperature 30°C higher than the flow initiation temperature for 1 hour. , the structural change caused by cross-linking is small. That is, in the case of the liquid crystal polyester composition of the present embodiment, when the liquid crystal polyester composition is kept at a high temperature (for example, 360° C. or higher) where side reactions are likely to occur, the liquid crystal polyester molecules are less likely to interact with each other. Side reactions such as cross-linking or decomposition reactions.

The reason for suppressing the above-mentioned side reactions is presumably due to the strong interaction between the liquid crystal polyester and the glass fiber constituting the liquid crystal polyester composition of the present embodiment. That is, it is considered that the liquid crystal polyester composition of the present embodiment is a composition having a strong interaction between the liquid crystal polyester and the glass fiber.

In addition, the present inventors discovered that the liquid crystal polyester composition satisfying the element (ii) is excellent in thin-wall fluidity, and completed the present invention.

As described above, when the value of 100×b/a, which is an “indicator of the strength of the interaction between the liquid crystal polyester and the glass fiber”, is 50 or more and 200 or less, the interaction becomes strong enough to obtain heat resistance. A liquid crystal polyester composition with high thin-walled fluidity.

In this specification, the thin-walled flowability of the liquid crystal polyester composition is high, and specifically means that the thin-walled flow length obtained by the following method is long.

The method for measuring the thin-wall flow length of the liquid crystal polyester composition will be described with reference to FIG. 2 . Fig. 2 is a schematic diagram of the structure of the mold for measuring the thin-walled flow length according to the present embodiment. In the present embodiment, the thin-walled flow length measuring die (0.3 mmt) shown in Fig. 2 is used, and the liquid crystal polyester composition is injected into a molding machine (roboshot S2000i-30B manufactured by FANUC) at a cylinder temperature of 380°C. , Molding was performed under the conditions of a mold temperature of 130°C and an injection speed of 200mm/sec. The thin-walled flow length was obtained by measuring the length of the taken out molded body.

The thin-wall flow length is preferably more than 20mm.

Various molded articles can be obtained by molding the liquid crystal polyester composition of the present embodiment. Examples of the molded body include optical pickup bobbins, bobbins such as transformer bobbins, relay cases, relay bases, relay sprues, and relay circuits. Relay parts such as relay armature; RIMM, DDR, CPU socket, S/O, DIMM, board to board connector, FPC connector, card connector and other connectors; lamps Reflectors such as reflectors and LED reflectors; supports such as lamp sockets and heater sockets; diaphragms such as speaker diaphragms; separation claws for copiers, separation claws for printers, etc.; camera modules ( camera module) parts; switch parts; motor parts; sensor parts; hard disk drive parts; tableware such as ovenware; vehicle parts; aircraft parts; components such as sealing components.

<Production method of liquid crystal polyester composition>

The said liquid crystalline polyester composition is obtained by melt-kneading at least liquid crystalline polyester and glass-made raw fiber (hereinafter also referred to as raw fiber) with an extruder.

The liquid crystal polyester composition having a flow initiation temperature of 330° C. or higher and 450° C. or lower can be obtained by using the liquid crystal polyester having a flow initiation temperature of 330° C. or higher and 450° C. or lower as a raw material. In addition, the flow initiation temperature of the liquid crystal polyester composition can be measured according to the same method as that of the liquid crystal polyester.

The liquid crystalline polyester in the method for producing the liquid crystalline polyester composition of the present embodiment may be commercially available, may be produced by a known method, or may be composed of a The raw material monomers are synthesized.

When synthesizing the liquid crystal polyester, it is preferably produced by melt-polymerizing raw material monomers and subjecting the obtained polymer (hereinafter also referred to as "prepolymer") to solid-phase polymerization. Thereby, a high-molecular-weight liquid crystal polyester having high heat resistance and high strength/rigidity can be produced with good workability.

The melt polymerization can be carried out in the presence of a catalyst. Examples of catalysts that can be used for melt polymerization include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide; and 4-( Nitrogen-containing heterocyclic compounds such as dimethylamino) pyridine and 1-methylimidazole. Preferably, nitrogen-containing heterocyclic compounds are used.

The raw material fibers in the method for producing the liquid crystal polyester composition of the present embodiment preferably have a number average fiber length of 1 mm or more, more preferably 1 mm or more and 10 mm or less, and still more preferably 1 mm or more and 6 mm or less. In addition, the number-average fiber length may be 2 mm or more, or 3 mm or more. On the other hand, the number average fiber length may be 2 mm or more and 10 mm or less, 3 mm or more and 10 mm or less, 2 mm or more and 6 mm or less, or 3 mm or more and 6 mm or less.

The raw material fiber in the aforementioned production method is preferably a chopped strand with a narrow distribution of fiber lengths.

[melt kneading]

Next, the procedure of melt-kneading the liquid crystal polyester and the raw material fibers will be described.

FIG. 1 is a schematic cross-sectional view showing an example of an extruder related to the step of melt-kneading in the above-mentioned production method. Hereinafter, the case where the liquid crystal polyester composition is produced by melt-kneading the liquid crystal polyester and the raw material fibers using the extruder shown in FIG. 1 will be described.

An extruder 10 shown in FIG. 1 includes a motor 1 accommodated in a motor box 1a, a cylinder 2 provided adjacent to the motor box 1a, and a cylinder 2 inserted into the cylinder 2 and connected to the motor 1 connected screw (screw) 3. The extruder 10 shown in FIG. 1 is a two-shaft extruder in which two screws 3 are inserted into the cylinder 2 .

The cylinder 2 is provided with: a main feed port 5 for supplying the liquid crystal polyester and raw fibers into the cylinder 2; The raw fiber is supplied to the side feed port 7 in the cylinder 2, the first vent 4 and the second vent 6 for discharging the volatile components (gas) generated in the cylinder 2, and the melt-kneaded liquid crystal The ejection die 9 for molding the polyester composition. Moreover, the discharge die 9 is provided with the nozzle hole 9a.

The main feed port 5 and the side feed port 7 are provided with: a hopper connected to the inside of the cylinder 2, and a supply device (neither are not shown) for supplying liquid crystal polyester and raw fiber.

The screw 3 includes a conveying portion 8 for conveying the liquid crystal polyester composition. Further, the screw 3 is provided with a first kneading section 11 for plasticizing and kneading the liquid crystal polyester composition between the main feed port 5 and the side feed port 7 . Furthermore, the screw 3 is provided with the second kneading part 12 for plasticizing and kneading the liquid crystal polyester composition between the side feed port 7 and the first vent hole part 4 . Further, the screw 3 is provided with a third kneading portion 13 for kneading the liquid crystal polyester composition between the first vent hole portion 4 and the second vent hole portion 6 . In addition, a fourth kneading portion and a fifth kneading portion may be further provided between the first vent hole portion 4 and the second vent hole portion 6 . At this time, it is preferable to adequately control the temperature rise of the cylinder caused by heat generation by shearing force.

The production method of the liquid crystal polyester composition of the present embodiment includes "the step of melt-kneading the liquid-crystalline polyester having a flow initiation temperature of 330°C or higher and raw fibers having a number-average fiber length of 1 mm or more." In this step, it is preferable to carry out melt-kneading until the raw material fibers become glass fibers having a number average fiber length of 30 μm or more and 200 μm or less.

In the production method of the liquid crystal polyester composition of the present embodiment, the raw material fibers having a number average fiber length of 1 mm or more and the liquid crystal polyester are kneaded and simultaneously broken, and melt-kneaded until the number-average fibers are obtained. Glass fibers with a length of not less than 30 μm and not more than 200 μm.

The liquid crystal polyester composition of the present embodiment can be produced by the above-described production method. In the liquid crystal polyester composition of the present embodiment, the raw fiber system is broken, and the liquid crystal polyester and the raw fiber system are strongly kneaded. Therefore, in the liquid crystal polyester composition of the present embodiment, it is recognized that the glass fibers are uniformly dispersed. Furthermore, in the liquid crystal polyester composition of the present embodiment, it is recognized that the liquid crystal polyester and the glass fiber interact strongly. Therefore, it is considered that the liquid crystal polyester composition of the present embodiment has high heat resistance and high thin-wall fluidity.

In the case of using the extruder 10, as long as the number-average fiber length of the glass fibers in the liquid crystal polyester composition can be adjusted to a desired length, the liquid crystal polyester, raw material fibers and The supply ratio of the components prepared as needed is not particularly limited. Similarly, the supply ratio of the liquid crystal polyester supplied to the side feed port 7, the raw material fiber, and the components prepared as needed is not particularly limited.

The temperature of the cylinder 2 of the extruder 10 is preferably kneaded at a temperature at which the liquid crystal polyester melts (for example, 340°C to 400°C). In addition, in order to suppress the excessive temperature rise of the molten resin caused by heat generation by shearing force, the temperature of the cylinder 2 can be reduced to a lower temperature than the “liquid crystal polyester will melt” by being located on the downstream side of the side feed port 7 Temperature" 120 ℃ lower temperature.

The discharge rate of the liquid crystal polyester composition from the "discharge die 9 of the extruder 10" is preferably 200 kg/hour to 400 kg/hour. Furthermore, the rotation number of the screw 3 of the extruder 10 is preferably 500 rpm to 800 rpm. In addition, these manufacturing conditions are preferably adjusted so that the torque (torque) of the electric motor 1 which the extruder 10 has is 60% or more with respect to the maximum torque of the extruder.

In the method for producing the liquid crystalline polyester composition of the present embodiment, after the liquid crystalline polyester and the raw fiber are melt-kneaded, pellets composed of the liquid crystalline polyester composition can be formed.

The molding method of the liquid crystal polyester composition is preferably a melt molding method. Examples of melt molding methods include extrusion molding methods such as injection molding, T-die molding, and inflation molding, compression molding, blow molding, vacuum molding, and pressure molding. . Among them, the injection molding method is particularly preferred.

On the other hand, the method for producing a liquid crystal polyester composition of the present embodiment includes: "a liquid crystal polyester having a flow initiation temperature of 330°C or higher" and "raw fibers having a number average fiber length of 1 mm or higher" , and "fillers, additives, and at least one component selected from the group consisting of resins other than the aforementioned liquid crystal polyesters" are supplied to the extruder; the aforementioned raw fibers supplied to the aforementioned extruder and the aforementioned The liquid crystal polyester is melt-kneaded until the raw material fibers become glass fibers having a number average fiber length of 30 μm or more and 200 μm or less, and pellets composed of the liquid crystal polyester composition are obtained by molding the melt-kneaded product.

In addition, the extruder in the manufacturing method of the liquid crystal polyester composition of one aspect of this invention is not limited to the extruder of the structure shown in FIG. 1. FIG. For example, it is preferable to use a cylinder body, at least one screw arranged in the cylinder body, and supply ports (main feed port and side feed port) provided at two or more places in the cylinder body. It is more suitable for those with at least one vent hole in the cylinder.

In addition, the extruder to which one aspect of the present invention can be applied can specifically be either a single-screw extruder or a two-screw extruder. Two-axis extruders can be listed as: co-rotating single-thread thread to three-thread thread, counter-rotating parallel-axis type, oblique-axis type or incomplete meshing type, etc. Departure is better.

Furthermore, when the number-average fiber length of the glass fibers contained in the liquid crystal polyester composition (or pellets) does not satisfy the target value, the liquid crystal polyester composition (or pellets) may be repeatedly fed from the supply port of the extruder again. It is charged and melt-kneaded until the number-average fiber length of the glass fibers reaches the target value.

The liquid crystal polyester composition of the present embodiment has high heat resistance and high thin-wall fluidity. Furthermore, according to the manufacturing method of the liquid crystal polyester composition of this embodiment, it is possible to obtain a liquid crystal polyester composition with high heat resistance and thin-walled fluidity.

As mentioned above, although the example of the suitable embodiment of this invention was demonstrated with reference to the attached drawings, it goes without saying that this invention is not limited to these examples. The shapes and combinations of the structural members shown in the above examples are only examples, and various changes can be made according to design requirements and the like as long as they do not depart from the scope of the present invention.

The present invention provides a liquid crystal polyester composition comprising: liquid crystal polyester; glass fiber; and optionally at least one selected from the group consisting of fillers other than glass fiber, additives, and resins other than the liquid crystal polyester. A component; wherein, the liquid crystal polyester is a liquid crystal polyester having repeating units represented by the aforementioned general formulas (1) to (3), preferably having “repeating units derived from p-hydroxybenzoic acid, derived from Repeating units of 4,4'-dihydroxybiphenyl, repeating units derived from terephthalic acid, and liquid crystal polyesters derived from repeating units derived from isophthalic acid; the number-average fiber length of the aforementioned glass fibers is 30 μm or more and 200 μm or less, preferably 50 μm or more and 170 μm or less, more preferably 70 μm or more and 150 μm or less, still more preferably 80 μm or more and 100 μm or less, particularly preferably 80 μm or more and 86 μm or less; and the liquid crystal polyester composition satisfies the following: Conditions of (i) and (ii):

(i) The flow initiation temperature of the liquid crystal polyester composition is 330°C or higher, preferably 350°C or higher and 400°C or lower, more preferably 360°C or higher and 390°C or lower, or 330°C or higher and 347°C or lower.

(ii) Decomposition of the liquid crystal polyester contained in the liquid crystal polyester composition by n-butylamine to obtain a decomposed product of the liquid crystal polyester composition (that is, the liquid crystal polyester treated with n-butylamine) After the decomposition product of the composition), in the chromatogram obtained by measuring the above-mentioned decomposition product by liquid chromatography under the following conditions, the "peak area with a retention time of 21.90 minutes" is relative to " The area ratio of the peak area for the retention time of 2.50 minutes is taken as a; the liquid crystal polyester composition after being kept at a temperature 30°C higher than the flow initiation temperature of the liquid crystal polyester composition for 1 hour has the same value as the above. In the chromatogram obtained by the method, the area ratio of the "peak area with a residence time of 21.90 minutes" to the "peak area with a residence time of 2.50 minutes" is defined as b; in this case, the value of 100 × b/a It is 50 or more and 200 or less, preferably 60 or more and 150 or less, more preferably 70 or more and 120 or less, and still more preferably 70 or more and 80 or less.

[condition]

Sample injection volume: 10 μL

×1250mm的ODS管柱(住化分析中心股份公司製，製品名「sumipax ODS KP-06」) Column: 5μm×4.6mm

×1250mm ODS column (manufactured by Sumika Analysis Center Co., Ltd., product name "sumipax ODS KP-06")

Column temperature: 40℃

Determination method: gradient elution method

Elution flow rate: 1.0mL/min

Detector: Ultraviolet Visible Spectrophotometer (UV)

Detection wavelength: 240nm

Eluent: Using (A) an aqueous solution added with 0.1% acetic acid and (B) an acetonitrile solution added with 0.1% acetic acid, the composition of the eluent was changed according to the following gradient conditions.

[gradient condition]

First, the ratio of the solution (B) was linearly changed from 10 vol % to 15 vol % with respect to the entire amount of the elution solution over a period of 15 minutes. Then, the ratio of the solution (B) was linearly changed from 15% by volume to 100% by volume with respect to the entire amount of the elution solution over 10 minutes.

(Example)

The following examples illustrate the present invention, but the present invention is not limited to these examples. In addition, the physical properties of the liquid crystal polyester and the liquid crystal polyester composition, and the number average fiber length of the glass fibers in the liquid crystal polyester composition were measured by the following methods.

[Measurement of flow initiation temperature of liquid crystal polyester]

Using a flow tester ("CFT-500 model" from Shimadzu Corporation), about 2 g of liquid crystal polyester was filled in a cylinder with a mold having a nozzle of 1 mm in inner diameter and 10 mm in length, and then placed in a cylinder. Under a load of 9.8 MPa (100 kg/cm ² ), the temperature was increased at a rate of 4° C./min while the liquid crystal polyester was melted, extruded from a nozzle, and the temperature at which it showed a viscosity of 4800 Pa·s (48000 poise) was measured.

[Measurement of the number-average fiber length of glass fibers in liquid crystal polyester compositions]

1 g of the pellets consisting of the liquid crystal polyester composition was taken into a crucible, and was treated in an electric furnace at 600° C. for 6 hours to be ashed. Next, the obtained residue was dispersed in methanol, and a microscope photograph (magnification: 100 times) was taken in a state of being spread on a glass slide. The length of the glass fiber was directly read from the photograph, and the average value was calculated. When calculating the average, the denominator is set to 400.

[Measurement of thin-wall flow length of liquid crystal polyester composition]

The thin-wall flowability of the liquid-crystalline polyester composition was evaluated by measuring the thin-wall flow length of the liquid-crystalline polyester composition by the following method. In this evaluation, the longer the thin-wall flow length of the liquid crystalline polyester composition is, the more excellent the thin-wall flowability of the liquid crystalline polyester composition is.

Using the thin-walled flow length measurement mold (0.3 mmt) shown in Fig. 2, the liquid crystal polyester composition was subjected to an injection molding machine (roboshot S2000i-30B manufactured by FANUC) at a cylinder temperature of 380°C and a mold temperature of 130°C. , Molding under the condition of injection speed of 200mm/sec.

The lengths of the cavity portions of the extracted molded bodies were measured for the five molded bodies, and the average value was used as the thin-wall flow length.

[Measurement of the rate of change (100×b/a) of the area ratio of the “peak area derived from component X” to the “peak area derived from N-n-butyl-p-hydroxybenzamide”]

For the measurement of the rate of change (100×b/a) of the area ratio (100×b/a) of the “peak area derived from component X” to the “peak area derived from N-n-butyl-p-hydroxybenzamide”, the following structural device.

[structure]

Device: Tosoh Corporation, high-speed liquid chromatography system

Pump: LC-20AD

Pump controller: CMB-20A

Autosampler: SIL-20AHT

Column oven: CTO-20A

(Preparation of sample)

The liquid crystal polyester composition described above was put into an eggplant-shaped flask fed with n-butylamine containing N-methylpyrrolidone, a cooling tube was installed, the sample was dissolved in a sand bath at 200°C, and further decomposed for 2 hours . Then, excess n-butylamine was removed by an evaporator in a sand bath at 80° C., and after neutralization by adding formic acid, N-methylpyrrolidone and anisic acid were fed as a sample solution.

(measurement)

The prepared sample was measured by liquid chromatography under the following conditions to obtain a chromatogram, and the "peak area with a retention time of 21.90 minutes" was determined relative to the spectrum with a "retention time of 2.50 minutes". The area ratio of "peak area", and this is taken as the peak area ratio a. Similarly, samples were prepared in the same manner for the aforementioned liquid crystal polyester composition after being kept at a temperature 30°C higher than the flow initiation temperature of the liquid crystal polyester composition for 1 hour, and liquid chromatography was performed under the following conditions. The measurement was performed to obtain a chromatogram, and the area ratio of the "peak area with a residence time of 21.90 minutes" to the "peak area with a residence time of 2.50 minutes" was obtained, and this was taken as the peak area ratio b. The value of 100×b/a is calculated according to the value of these spectral peak area ratios. In addition, in this example, the value of 100×b/a means the area of the “spectrum peak area derived from component X” relative to the “spectrum peak area derived from N-n-butyl-p-hydroxybenzamide” ratio of change.

[condition]

Sample injection volume: 10 μL

×1250mm) Column: manufactured by Sumika Analysis Center Co., Ltd., product name "sumipax ODS KP-06" (5μm × 4.6mm

×1250mm)

Column temperature: 40℃

Determination method: gradient elution method

Elution flow rate: 1.0mL/min

Detector: Ultraviolet Visible Spectrophotometer (UV)

Detection wavelength: 240nm

Eluent: Using (A) an aqueous solution added with 0.1% acetic acid and (B) an acetonitrile solution added with 0.1% acetic acid, the composition of the eluent was changed according to the following gradient conditions.

[gradient condition]

First, the ratio of the solution (B) was linearly changed from 10 vol % to 15 vol % with respect to the entire amount of the elution solution over a period of 15 minutes. Next, the ratio of the solution (B) was linearly changed from 15% by volume to 100% by volume with respect to the entire amount of the elution solution over 10 minutes.

<Production of liquid crystal polyester> [Production Example 1]

994.5 g (7.2 moles) of p-hydroxybenzoic acid, 446.9 g (2.4 moles) of 4,4'-dihydroxybiphenyl were added to a reactor equipped with a stirring device, a torque meter, a nitrogen gas introduction pipe, a thermometer and a reflux cooler. ), 365.4 g (2.2 mol) of terephthalic acid, 33.2 g (0.2 mol) of isophthalic acid, 1347.6 g (13.2 mol) of acetic anhydride, and 0.194 g of 1-methylimidazole as a catalyst. Warm stirring was performed for 15 minutes to sufficiently replace the inside of the reactor with nitrogen, and then the temperature was raised while stirring. After the internal temperature became 145°C, the same temperature was maintained and stirred for 1 hour.

Thereafter, the temperature was raised to 320° C. for 2 hours and 50 minutes while distilling off the distilled by-product acetic acid and unreacted acetic anhydride, and the time point at which an increase in torque was confirmed was regarded as the completion of the reaction to obtain a prepolymer. .

The flow onset temperature of the prepolymer was 263°C.

The obtained prepolymer was cooled to room temperature, and pulverized with a coarse pulverizer to obtain a powder of liquid crystal polyester (particle size of about 0.1 mm to about 1 mm). Then, the liquid crystal polyester powder was heated from room temperature to 250°C in a nitrogen atmosphere over 1 hour, then heated from 250°C to 300°C over 5 hours, and held at 300°C for 3 hours to conduct a polymerization reaction in a solid phase. The flow initiation temperature of the obtained liquid crystal polyester was 361°C.

<Production of liquid crystal polyester composition>

In the following examples and comparative examples, the following materials were used as raw fibers.

Raw fiber A: manufactured by Nitto Textile Co., Ltd., trade name "CS-3J-260S" (number-average fiber length: 3 mm)

Raw fiber B: manufactured by Central Glass Co., Ltd., trade name "MILLED FIBER EFH75-01" (number-average fiber length: 91 μm)

In addition, as an extruder, a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., model "TEM-41SS") was used. The structure of this two-screw extruder is that a fourth kneading part is added to the first vent hole part and a fifth kneading part is added to the second vent hole part to the extruder of the structure shown in FIG. 1 .

[Example 1]

Using 45 parts by mass of the raw fiber A and 55 parts by mass of the liquid crystal polyester obtained in Production Example 1, a liquid crystal polyester composition was produced by a biaxial extruder.

80% of the total amount of the liquid crystal polyester was supplied from the main feed port of the biaxial extruder, and 20% of the total amount of the liquid crystal polyester and the raw material fiber A were supplied from the side feed port. In addition, in order to suppress the increase in the cylinder temperature due to heat generation by shear force, the temperature from the second kneading section to the fifth kneading section was set to 280°C. In addition, it was set to 360 degreeC. A screw diameter of 41 mm was used, and a water pump was used for the second vent portion to maintain the vacuum degree so that the gauge pressure was -0.09 MPa (atmospheric pressure was regarded as 0 MPa). As the screw system, one with two coaxial axes (right rotation) was used, and the screw rotation number system was set to 650 rpm, and the extrusion rate was 300 kg/hour. The liquid crystal polyester and the raw fiber A are melt-kneaded under such conditions to obtain a liquid crystal polyester composition.

The flow initiation temperature of the liquid crystal polyester composition obtained in Example 1 was 347°C. Furthermore, the number-average fiber length of the glass fibers in the liquid crystal polyester composition was 86 μm.

[Comparative Example 1]

Using 45 parts by mass of the raw fiber B and 55 parts by mass of the liquid crystal polyester obtained in Production Example 1, a liquid crystal polyester composition was produced by a biaxial extruder. The same procedure as in Example 1 was carried out, except that "the entire amount of liquid crystal polyester was supplied from the main feed port of this twin-screw extruder, the raw fiber B was fed from the side feed port, and the processing temperature was uniformly set to 360°C." method of manufacture.

The flow initiation temperature of the liquid crystal polyester composition obtained in Comparative Example 1 was 347°C. Furthermore, the number-average fiber length of the glass fibers in the liquid crystal polyester composition was 87 μm.

Table 1 summarizes the liquid crystalline polyester composition blending ratio and various physical property values of Example 1 and the comparative example, and the number-average fiber length of glass fibers in the liquid crystalline polyester composition.

As shown in Table 1, for the liquid crystal polyester composition of Example 1 produced by the production method of one aspect of the present invention, even if the flow initiation temperature was approximately the same as that of Comparative Example 1, 100×b The value of /a is lower than that of Comparative Example 1. That is, the liquid crystal polyester composition of Example 1 showed the same heat resistance as that of Comparative Example 1, but relatively, the "peak area derived from component X" was relatively Example 1 is smaller than Comparative Example 1 in terms of the rate of change of the area ratio of the peak area of the benzamide. Furthermore, in other words, the liquid crystalline polyester composition of Example 1 showed the same heat resistance as that of Comparative Example 1, but in comparison with Comparative Example 1, it can be said that the molecular chains of the liquid crystalline polyester in Example 1 were not formed with each other. cross-linking reaction.

Furthermore, as shown in Table 1, the thin-wall flow length of the liquid crystal polyester composition of Example 1 was longer than that of Comparative Example 1. That is, the liquid crystal polyester composition of Example 1 showed the same heat resistance as that of Comparative Example 1, but relatively, Example 1 was superior to Comparative Example 1 in terms of thin-wall flowability.

From the above, it can be seen that the present invention is useful.

[Industrial Availability]

The liquid crystal polyester composition of the present invention has high heat resistance and high thin-wall fluidity, and is therefore extremely useful industrially.

The schematic diagram of this case is a schematic diagram of the extruder or die used in the embodiment of this case, and is not sufficient to represent the invention of the composition claimed in the scope of the patent application of this case, so there is no designated representative diagram in this case.

Claims (3)

A liquid crystal polyester composition comprising liquid crystal polyester and glass fiber; wherein, the liquid crystal polyester composition satisfies the following conditions (i) and (ii); (i) the flow of the liquid crystal polyester composition The initial temperature is 330°C or higher; (ii) after the liquid crystal polyester contained in the liquid crystal polyester composition is decomposed by n-butylamine to obtain a decomposed product of the liquid crystal polyester composition, the decomposed product is placed in the liquid crystal polyester composition. In the chromatogram obtained by the measurement by liquid chromatography under the following conditions, the area ratio of the peak area at the retention time of 21.90 minutes to the area of the peak at the retention time of 2.50 minutes was defined as a, and in the comparison In the chromatogram of the liquid crystalline polyester composition obtained by the same method as above after the liquid crystalline polyester composition was kept at a temperature higher than 30°C for 1 hour, the retention time was 21.90 minutes. The area ratio of the peak area to the peak area with a retention time of 2.50 minutes is defined as b. In this case, the value of 100×b/a is 50 or more and 200 or less; [Conditions] Sample injection volume: 10 μL column: Sumika analysis Made by Central Co., Ltd., product name "sumipax ODS KP-06" (5μm × 4.6mm

×1250mm) Column temperature: 40°C Measurement method: Gradient elution method Eluent flow rate: 1.0mL/min Detector: Ultraviolet visible light spectrophotometer (UV) Detection wavelength: 240nm A 0.1% acetic acid aqueous solution and (B) an acetonitrile solution added with 0.1% acetic acid were used to change the composition of the elution solution according to the following gradient conditions; The concentration was linearly changed from 10% by volume to 15% by volume with the entire amount of the solution; then, the ratio of the solution (B) was linearly changed from 15% by volume to 100% by volume relative to the entire amount of the eluent in 10 minutes. The liquid crystal polyester composition according to claim 1, wherein the flow initiation temperature of the liquid crystal polyester is 330°C or higher and 390°C or lower. The liquid crystal polyester composition according to claim 1 or 2, wherein the number average fiber length of the glass fibers is 30 μm or more and 100 μm or less, and the liquid crystal polyester composition is obtained by combining the liquid crystal polyester with the number average fiber length of 1 mm. The above raw material fibers are melt-kneaded until the raw material fibers become glass fibers having a number-average fiber length of 30 μm or more and 100 μm or less.

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