WO2019240013A1 - Composition - Google Patents

Abstract

Provided is a composition containing a liquid crystal polymer and an antioxidant having excellent heat resistance. This composition contains: at least one type of liquid crystal polymer selected from between a liquid crystal polyester and a liquid crystal polyesteramide; and diamond nanoparticles at quantities whereby the proportion of the diamond nanoparticles is 0.001-5 parts by weight relative to 100 parts by weight of the liquid crystal polymer. The liquid crystal polymer preferably has the constitution shown below. Relative to all constituent units that constitute the liquid crystal polymer, the content of constituent units represented by formula (I) is 50-100 mol%, the content of constituent units represented by formula (II) is 0-25 mol%, and the content of constituent units represented by formula (III) is 0-25 mol%.

Description

Composition

The present invention relates to a composition comprising a liquid crystal polymer and nanodiamond particles. This application claims the priority of Japanese Patent Application No. 2018-1113023 for which it applied to Japan on June 13, 2018, and uses the content here.

The problem is that the resin is oxidized and deteriorated by exposure to heat and light, and it becomes brittle or yellowed. In order to prevent this, an antioxidant is added to the resin. For example, Patent Document 1 describes a heat-resistant thermoplastic composition containing a thermoplastic elastomer and an antioxidant. As the antioxidant, an aromatic amine-based antioxidant, a hindered phenol-based antioxidant, a sulfur It describes that a system antioxidant, a phosphorus antioxidant, etc. can be used.

On the other hand, the liquid crystal polymer has a high melting point of 300 ° C. or higher, and can stably maintain its shape even in a high temperature environment (for example, a high temperature environment of 150 ° C. or higher and lower than 300 ° C.) It is possible to suppress the occurrence and maintain the shape with high accuracy). That is, it is excellent in heat resistance.

Further, in order to mold the liquid crystal polymer, it is necessary to heat at a temperature higher than the melting point of the liquid crystal polymer. However, there is a problem that the liquid crystal polymer is easily oxidized and deteriorated by heating at a temperature higher than the melting point. This is because even if an antioxidant is added to the liquid crystal polymer, the antioxidant is volatilized or thermally decomposed by high-temperature heating during molding, and the desired effect cannot be obtained.

JP 2011-116856 A

Accordingly, an object of the present invention is to provide a composition comprising a liquid crystal polymer and an antioxidant having excellent heat resistance.
Another object of the present invention is to provide an antioxidant having heat resistance at a temperature equal to or higher than the molding temperature of the liquid crystal polymer.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have excellent heat resistance and do not volatilize or decompose even when heated to 400 ° C. in an oxygen atmosphere. It has been found that when nanodiamond particles are added to a liquid crystal polymer, the nanodiamond particles trap peroxy radicals, thereby preventing oxidative degradation of the liquid crystal polymer in a high temperature environment. The present invention has been completed based on these findings.

That is, in the present invention, at least one liquid crystal polymer selected from liquid crystal polyester and liquid crystal polyester amide and nanodiamond particles are added in an amount of 0.001 to 5 parts by weight of nanodiamond particles with respect to 100 parts by weight of the liquid crystal polymer. Compositions containing in proportions are provided.

The present invention also provides the composition, wherein the liquid crystal polymer has the following constitution.
In all structural units constituting the liquid crystal polymer,
The content of the structural unit represented by the following formula (I) is 50 to 100 mol%,
The content of the structural unit represented by the following formula (II) is 0 to 25 mol%,
The content of the structural unit represented by the following formula (III) is 0 to 25 mol%

(Wherein Ar ¹ to Ar ³ are the same or different and may have at least one substituent selected from a halogen atom, an alkyl group, and an aryl group, a phenylene group, a naphthylene group, or biphenylylene) And X and Y are the same or different and represent —O— or —NH—.

The present invention also provides the composition, wherein the nanodiamond particles are detonation nanodiamond particles.

The present invention is also in the infrared absorption spectrum by Fourier transform infrared spectrophotometer of nanodiamond particles, the maximum peak of 1700 ~ 1850 cm ^-1 is provided a higher than the maximum peak of 2800 ~ 3000 cm ^-1 wherein the composition To do.

The present invention also provides the composition, wherein the amount of radicals generated at 320 ° C. measured by electron spin resonance is 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g.

The present invention also provides the composition, wherein the radical generation amount at 400 ° C. measured by an electron spin resonance method is not more than 3.0 times the radical generation amount at 25 ° C.

The present invention also provides a molded body comprising a solidified product of the composition.

The present invention also provides an antioxidant for thermoplastic resin containing nanodiamond particles.

The present invention also provides the antioxidant for a thermoplastic resin, wherein the 5% weight reduction temperature measured at a heating rate of 10 ° C./min (in air) is 450 ° C. or higher.

The composition of the present invention contains nanodiamond particles together with a liquid crystal polymer, and the nanodiamond particles exhibit an action of capturing peroxy radicals that cause oxidative deterioration of the liquid crystal polymer. Therefore, even when the composition of the present invention is heated at a high temperature, the liquid crystal polymer can be prevented from being oxidatively deteriorated, and the toughness of the liquid crystal polymer can be reduced due to the oxidative deterioration and can be prevented from becoming brittle. In addition, yellowing due to oxidative degradation can be suppressed, and the hue can be maintained well.
In addition, the melt of the composition of the present invention is excellent in fluidity, has little shrinkage due to solidification, and can suppress the occurrence of warpage. Therefore, a molded body having a desired shape can be manufactured with high accuracy.
Furthermore, the molded article of the composition of the present invention suppresses deterioration of physical properties (for example, toughness, embrittlement, etc.) over a long period of time even in a high temperature environment (for example, a high temperature environment of 150 ° C. or higher and lower than 400 ° C.). be able to. Therefore, it withstands long-term use at high temperatures.
Since the composition of the present invention has the above-mentioned characteristics, for example, printed circuit board mounting parts, connectors / bobbins / optical pickup parts cases, micromotor parts and other electric / electronic parts materials; compressor parts, shock absorber parts and other automobiles It can be suitably used as a component material.

Further, the antioxidant of the present invention contains, as a main component, nanodiamond particles having both an antioxidant effect (or peroxy radical scavenging effect) and heat resistance. Therefore, it can be suitably used as an antioxidant (or a peroxy radical scavenger) for a high melting point thermoplastic resin having a molding temperature of 300 ° C. or higher.

4 is a diagram showing FT-IR data of ND1 obtained in Example 1. FIG. 6 is a diagram showing FT-IR data of ND2 obtained in Example 2. FIG. 6 is a diagram showing FT-IR data of ND3 obtained in Example 3. FIG. 6 is a diagram showing FT-IR data of ND4 obtained in Example 4. FIG. It is a correlation diagram of temperature and the amount of radical generation of the composition obtained in Example 8 and Comparative Example 1 obtained by ESR measurement.

[Composition]
The composition of the present invention comprises at least one liquid crystal polymer selected from liquid crystal polyester and liquid crystal polyester amide, and nanodiamond particles (hereinafter sometimes referred to as “ND particles”) in 100 parts by weight of the liquid crystal polymer. The nanodiamond particles are contained at a ratio of 0.001 to 5 parts by weight with respect to the above.

(Liquid crystal polymer)
The liquid crystal polymer in the present invention refers to a melt processable polymer having a property capable of forming an optically anisotropic melt phase. The property of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. 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 a magnification of 40 times. When the liquid crystal polymer of the present invention is inspected between crossed polarizers, the polarized light is usually transmitted and optically anisotropic even if it is in a molten stationary state.

The liquid crystal polymer in the present invention is at least one liquid crystal polymer selected from liquid crystal polyester and liquid crystal polyester amide.

Examples of the liquid crystal polymer include at least a structural unit represented by the following formula (I) and may include a structural unit represented by the following formula (II) and / or a structural unit represented by the following formula (III). A good liquid crystal polymer is mentioned.

(Wherein Ar ¹ to Ar ³ are the same or different and may have at least one substituent selected from a halogen atom, an alkyl group, and an aryl group, a phenylene group, a naphthylene group, or biphenylylene) And X and Y are the same or different and represent —O— or —NH—.

Examples of the halogen atom that Ar ¹ to Ar ³ in the above formula may have as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkyl group that may have as a substituent include alkyl groups having 1 to 3 carbon atoms such as a methyl group, an ethyl group, a propyl group, and an isopropyl group.

Examples of the aryl group that may be present as a substituent include aryl groups having 6 to 14 carbon atoms (particularly 6 to 10 carbon atoms) such as a phenyl group and a naphthyl group.

In all structural units constituting the liquid crystal polymer,
The content of the structural unit represented by the formula (I) is, for example, 50 to 100 mol%.
The content of the structural unit represented by the formula (II) is, for example, 0 to 25 mol%.
The content of the structural unit represented by the formula (III) is, for example, 0 to 25 mol%.

Content of the structural unit represented by the above formula (I), the structural unit represented by the above formula (II), and the structural unit represented by the above formula (III) with respect to all the structural units constituting the liquid crystal polymer ( The total content) is, for example, 70 mol% or more, preferably 80 mol% or more, particularly preferably 90 mol% or more.

Further, in the liquid crystal polymer, the content of the structural unit represented by the following formula (VI) is preferably, for example, 30 mol% or less, more preferably 20 mol% or less, based on all the structural units constituting the liquid crystal polymer. Especially preferably, it is 10 mol% or less, Most preferably, it is 5 mol% or less, Most preferably, it is 1 mol% or less. When content of the structural unit shown by following formula (VI) exceeds the said range, there exists a tendency for the antioxidant effect by ND particle | grains to become difficult to be acquired.

(Wherein Ar ⁴ to Ar ⁶ are the same or different and each may have at least one substituent selected from a halogen atom, an alkyl group, and an aryl group, a phenylene group, a naphthylene group, or biphenylylene) Group)

More specifically, examples of the liquid crystal polymer include the following embodiments (1) to (5). Furthermore, you may use a molecular weight modifier together with the following structural component as needed.
(1) A polyester mainly composed of one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(2) mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(B) a polyester comprising one or more aromatic dicarboxylic acids and derivatives thereof;
(3) mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(B) one or more of aromatic dicarboxylic acids and derivatives thereof;
(C) a polyester comprising one or more aromatic diols and derivatives thereof;
(4) mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(B) one or more of aromatic hydroxyamine, aromatic diamine, and derivatives thereof;
(C) a polyesteramide comprising an aromatic dicarboxylic acid and one or more of its derivatives;
(5) mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(B) one or more of aromatic hydroxyamine, aromatic diamine, and derivatives thereof;
(C) one or more aromatic dicarboxylic acids and derivatives thereof;
(D) Polyesteramide comprising one or more aromatic diols and derivatives thereof

Preferable specific examples of the monomer constituting the liquid crystal polymer include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4 Aromatic diols such as, 4'-dihydroxybiphenyl, hydroquinone, resorcin; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid; p-aminophenol, and aromatic amines such as p-phenylenediamine.

The liquid crystal polymer is not particularly limited and can be prepared by a known method, and examples thereof include a direct polymerization method and a transesterification method. In the direct polymerization method, the monomer (or monomer mixture) is melt-polymerized, solution-polymerized, slurry-polymerized, solid-phase polymerized, or a combination of two or more of these (preferably, melt-polymerized or melt-polymerized In combination with a solid phase polymerization method).

In the direct polymerization method, when the monomer is a compound having ester forming ability, it can be used for polymerization as it is, but when the monomer is a compound having no ester forming ability, an acylating agent (for example, It is preferable to use a derivative modified with a derivative having ester-forming ability using carboxylic anhydride such as acetic anhydride).

The polymerization of the monomer is preferably performed in the presence of a catalyst. Examples of the catalyst include metal salt catalysts and organic compound catalysts. These can be used alone or in combination of two or more.

Examples of the metal salt catalyst include potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, tris (2,4-pentanedionato) cobalt (III), etc. Is mentioned.

Examples of the organic compound catalyst include N-methylimidazole and 4-dimethylaminopyridine.

The amount of the catalyst used is, for example, about 0.0001 to 0.01 parts by weight with respect to 100 parts by weight of the monomer.

The polymerization temperature of the monomer is, for example, 200 to 400 ° C.

The atmosphere during the polymerization reaction of the monomer is not particularly limited as long as the reaction is not inhibited, and may be any of an air atmosphere, a nitrogen atmosphere, an argon atmosphere, and the like. The polymerization reaction of the monomer can be performed under reduced pressure, normal pressure, or increased pressure.

The liquid crystal polymer obtained by the above method can be further increased in molecular weight by solid phase polymerization heated in an inert gas. The heating temperature is, for example, 230 to 350 ° C., preferably 260 to 330 ° C., and the final ultimate pressure is, for example, 10 to 760 Torr (that is, 1330 to 101080 Pa).

The melting point or softening point of the liquid crystal polymer is, for example, 250 ° C. or higher, preferably 270 ° C. or higher. The upper limit of the melting point or softening point of the liquid crystal polymer is 400 ° C., for example.

As the melt viscosity of the liquid crystal polymer, the melt viscosity measured under conditions of a shear rate of 1000 sec ^{−1 at} a cylinder temperature 10 to 30 ° C. higher than the melting point or softening point of the liquid crystal polymer is, for example, 5 to 100 Pa · s, preferably 10 to 60 Pa · s, particularly preferably 15 to 50 Pa · s. The “cylinder temperature 10-30 ° C. higher than the melting point or softening point of the liquid crystal polymer” means a cylinder temperature at which the liquid crystal polymer can be melted to such an extent that the melt viscosity can be measured. The number of degrees C higher than the melting point or softening point can be appropriately selected depending on the type of the liquid crystal polymer within the temperature range (that is, within the range of 10 to 30 ° C.).

(Nanodiamond particles)
The primary particle diameter (D50, median diameter) of ND particles is 10 nm or less, preferably 8 nm or less, particularly preferably 7 nm or less, and most preferably 6 nm or less. The lower limit of the particle size of the ND particles is, for example, 2 nm.

It is preferable that the ND particles have a carbonyl group (C═O group) on the surface in terms of being excellent in an antioxidant effect (particularly, an antioxidant effect of a liquid crystal polymer). The ND particles in the present invention may have other functional groups (for example, C—H groups) in addition to carbonyl groups on the surface, but may have more carbonyl groups than other functional groups. preferable.

The surface functional group of the ND particle can be confirmed by an infrared absorption spectrum. For example, in the infrared absorption spectrum, 1700 tallest peak at ~ 1850 cm ^-1 (e.g., P1 in Fig. 1), the maximum peak of 2800 ~ 3000 cm ^-1 (e.g., P2 in Fig. 1) is higher than (details the absorption peak derived from C = O near 1712 cm ^-1, absorption peaks were observed originating from C-H in the vicinity of 2915 cm ^-1, absorption peaks of 1712 cm ^-1 is than the absorption peak of 2915 cm ^-1 When it is high), it can be seen that the ND particles have more carbonyl groups as surface functional groups than other functional groups. The infrared absorption spectrum can be measured using FTIR [Fourier transform infrared spectrophotometer; FT / IR-4200 type A (manufactured by JASCO Corporation)].

The ND particles can be produced, for example, by the detonation method described in detail below, but the ND particles in the present invention are not limited to those produced by this method.

(Generation process)
A molded explosive with an electric detonator is installed inside a pressure-resistant container for detonation, and the container is sealed in a state where atmospheric pressure gas and atmospheric explosive coexist in the container. . The container is made of, for example, iron, and the volume of the container is, for example, 0.5 to 40 m ³ . As the explosive, a mixture of trinitrotoluene (TNT) and cyclotrimethylenetrinitroamine, ie hexogen (RDX), can be used. The weight ratio of TNT to RDX (TNT / RDX) is, for example, in the range of 40/60 to 60/40.

In the generation process, the electric detonator is then detonated and the explosive is detonated in the container. Detonation refers to an explosion associated with a chemical reaction in which the reaction flame surface moves at a speed exceeding the speed of sound. At the time of detonation, ND particles are generated by the action of the pressure and energy of the shock wave generated by the explosion, using as a raw material carbon that has been partially incompletely burned by the explosive used. The produced ND particles are aggregated very strongly as a result of coulomb interaction between crystal planes in addition to the action of van der Waals force between adjacent primary particles or crystallites to form an aggregate.

In the production step, the container and the interior thereof are then allowed to cool by allowing to stand at room temperature for about 24 hours and allowing to cool. After this cooling, the ND particle crude product adhering to the inner wall of the container (including the ND particle aggregates and soot generated as described above) is scraped off with a spatula and collected. A crude product of ND particles can be obtained by the method as described above.

(Acid treatment process)
The acid treatment step is a step of removing metallic impurities mixed in the crude product of ND particles obtained through the production step, and the crude product of ND particles obtained by dispersing the crude product of ND particles in water. By adding an acid to the product dispersion to elute the metallic impurities into the acid, and then separating and removing the acid from which the metallic impurities are eluted, the metallic impurities can be removed. As the acid (particularly strong acid) used in the acid treatment, a mineral acid is preferable, and examples thereof include hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, aqua regia and the like. These can be used individually by 1 type or in combination of 2 or more types. The concentration of the acid used for the acid treatment is, for example, 1 to 50% by weight. The acid treatment temperature is, for example, 70 to 150 ° C. The acid treatment time is, for example, 0.1 to 24 hours. The acid treatment can be performed under reduced pressure, normal pressure, or increased pressure. As a method for separating and removing the acid from which the metallic impurities are eluted, it is preferable to carry out, for example, decantation. In decantation, it is preferable to wash the solids (including ND particles) with water, and it is particularly preferable to repeat the water washing until the pH of the precipitate reaches, for example, 2 to 3.

(Oxidation process)
The oxidation treatment step is a step of removing graphite from the ND particle crude product using an oxidizing agent. The crude product of ND particles obtained by the detonation method includes graphite (graphite), but this graphite does not form ND particle crystals out of the carbon released by partial incomplete combustion of the explosive used. Derived from carbon. For example, after passing through the above acid treatment, graphite can be removed from the ND particle crude product by applying a predetermined oxidizing agent in an aqueous solvent. In addition, an oxygen-containing group such as a carboxyl group or a hydroxyl group can be introduced to the surface of the ND particle by causing an oxidant to act.

Examples of the oxidizing agent used in this oxidation treatment include chromic acid, chromic anhydride, dichromic acid, permanganic acid, perchloric acid, nitric acid, and mixtures thereof, and at least one acid selected from these. And mixed acids of these with other acids (for example, sulfuric acid), and salts thereof. In the present invention, it is particularly preferable to use a mixed acid (particularly, a mixed acid of sulfuric acid and nitric acid) because it is environmentally friendly and excellent in oxidizing and removing graphite.

The mixing ratio of sulfuric acid and nitric acid in the mixed acid (the former / the latter; weight ratio) is, for example, 60/40 to 95/5, even under a pressure around normal pressure (for example, 0.5 to 2 atm). For example, it is preferable in that graphite can be efficiently oxidized and removed at a temperature of 130 ° C. or higher (particularly preferably 150 ° C. or higher, and the upper limit is, for example, 200 ° C.). The lower limit of the mixing ratio is preferably 65/35, particularly preferably 70/30. The upper limit of the mixing ratio is preferably 90/10, particularly preferably 85/15, and most preferably 80/20.

When the ratio of nitric acid in the mixed acid exceeds the above range, the content of sulfuric acid having a high boiling point is decreased. Therefore, the reaction temperature becomes, for example, 120 ° C. or less under a pressure near normal pressure, and the graphite removal efficiency tends to decrease. There is. On the other hand, when the ratio of nitric acid in the mixed acid is less than the above range, the content of nitric acid that greatly contributes to the oxidation of graphite is reduced, so that the graphite removal efficiency tends to decrease.

The amount of the oxidizing agent (especially the mixed acid) used is, for example, 10 to 50 parts by weight, preferably 15 to 40 parts by weight, and particularly preferably 20 to 40 parts by weight with respect to 1 part by weight of the ND particle crude product. The amount of sulfuric acid used in the mixed acid is, for example, 5 to 48 parts by weight, preferably 10 to 35 parts by weight, particularly preferably 15 to 30 parts by weight, based on 1 part by weight of the ND particle crude product. The amount of nitric acid used in the mixed acid is, for example, 2 to 20 parts by weight, preferably 4 to 10 parts by weight, particularly preferably 5 to 8 parts by weight, based on 1 part by weight of the ND particle crude product.

Further, when the mixed acid is used as the oxidizing agent, a catalyst may be used together with the mixed acid. By using a catalyst, the graphite removal efficiency can be further improved. Examples of the catalyst include copper (II) carbonate. The amount of the catalyst used is, for example, about 0.01 to 10 parts by weight with respect to 100 parts by weight of the ND particle crude product.

The oxidation treatment temperature is 100 to 200 ° C., for example. The oxidation treatment time is, for example, 1 to 24 hours. The oxidation treatment can be performed under reduced pressure, normal pressure, or increased pressure.

After such an oxidation treatment, it is preferable to remove the supernatant by, for example, decantation. In decantation, it is preferable to wash the solids with water. Although the supernatant liquid at the beginning of water washing is colored, it is preferable to repeat the water washing of the solid content until the supernatant liquid becomes transparent visually.

(Drying process)
In this method, it is preferable to provide a drying step next. For example, after the liquid content is evaporated from the ND particle-containing solution obtained through the above steps using a spray drying device, an evaporator, or the like, the resulting solid content is dried by heating and drying in a drying oven. A method is mentioned. The heating and drying temperature is, for example, 40 to 150 ° C. Through such a drying process, ND particles are obtained.

(Heat oxidation process)
In this method, it is preferable to provide a heat oxidation step next. The heating oxidation step is a step of obtaining ND particles having C═O groups on the surface thereof by heating and oxidizing the ND particles obtained through the above steps in an atmosphere containing oxygen.

The reaction atmosphere in the heating oxidation step is not particularly limited as long as it is a gas containing oxygen. In the present invention, it is preferable to use oxygen diluted with an inert gas such as nitrogen from the viewpoint of safety, and the concentration of oxygen is, for example, 0.01 to 30 v / v%, preferably 0. .1 to 25 v / v%, particularly preferably 0.5 to 10 v / v%.

The heating temperature in the heating oxidation step can be appropriately set in consideration of the heat resistance of the ND particles, and is preferably 200 to 800 ° C., more preferably 350 to 700 ° C., further preferably 400 to 600 ° C., and particularly preferably. 430-500 ° C. When the heating temperature is within the above range, oxidation of ND particles is suppressed, non-diamond carbon is selectively oxidized, ND particles having a large amount of C═O groups on the surface and excellent in the antioxidant effect are obtained. It is done.

The heating time in the heating and oxidizing step is not particularly limited, but is preferably 0.1 to 15 hours, more preferably 0.5 to 12 hours, and still more preferably 1 to 10 hours. When the heating time is within the above range, oxidation of ND particles is suppressed, non-diamond carbon is selectively oxidized, ND particles having a large amount of C═O groups on the surface and excellent in the antioxidant effect are obtained. It is done.

The pressure in the heating oxidation step is not particularly limited, but is preferably 0.01 to 5.0 atm, more preferably 0.1 to 1.5 atm, and further preferably 0.2 to 1.2 atm.

(Method for producing composition)
The composition of the present invention can be produced, for example, by melt-kneading a liquid crystal polymer and ND particles at a temperature equal to or higher than the melting point (or softening temperature) of the liquid crystal polymer.

The content of ND particles in the composition of the present invention is 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, particularly preferably 0.1 to 1 part by weight, based on 100 parts by weight of the liquid crystal polymer. Part.

The composition of the present invention contains a liquid crystal polymer and ND particles as nonvolatile components. In addition to the above components, the composition of the present invention includes other components (for example, fillers, stabilizers, lubricants, pigments, crystal nucleating agents, antifoaming agents, silane coupling agents, leveling agents, surfactants, flame retardants, 1 type or 2 types or more of ultraviolet absorbers, decolorizers, colorants, adhesion-imparting agents, etc.) may be contained, but the total content of the ND particles and the liquid crystal polymer in the total amount of nonvolatile content contained in the composition The amount is, for example, 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, still more preferably 40% by weight or more, still more preferably 50% by weight or more, still more preferably 60% by weight or more, particularly preferably. Is 70% by weight or more.

The filler includes a fibrous, powdery, or plate-like inorganic or organic filler.

Examples of the fibrous filler include glass fiber, milled glass fiber, carbon fiber, asbestos fiber, silica fiber, silica-alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, titanic acid. Silica fiber such as potassium fiber, wollastonite, magnesium sulfate fiber, aluminum borate fiber, inorganic fibrous material such as metal (for example, stainless steel, aluminum, titanium, copper, brass, etc.); polyamide resin , High melting point organic fibrous materials such as fluororesin, polyester resin, and acrylic resin. A particularly typical fibrous filler is glass fiber.

Examples of the particulate filler include metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony trioxide, and alumina; metal carbonates such as calcium carbonate and magnesium carbonate; metals such as calcium sulfate and barium sulfate Sulfates of carbon black, graphite, silica, quartz powder, glass beads, glass balloons, glass powder, calcium oxalate, aluminum oxalate, kaolin, clay, diatomaceous earth, wollastonite, etc., ferrite, Examples thereof include silicon carbide, silicon nitride, boron nitride, and various metal powders.

Examples of the plate-like filler include mica, glass flakes, talc, and various metal foils.

ND particles exhibit the effect of capturing peroxy radicals generated in the liquid crystal polymer. Since the composition of the present invention contains ND particles having the above-mentioned characteristics, an increase in radical generation amount (or peroxy radical generation amount) is suppressed by capturing peroxy radicals in ND particles even in a high temperature environment. In addition, the toughness of the liquid crystal polymer is reduced due to oxidative degradation due to the generated peroxy radicals, and embrittlement can be prevented, and yellowing due to oxidative degradation can be suppressed and the hue can be maintained well.

The radical generation amount at 25 ° C. of the composition of the present invention measured by electron spin resonance (ESR) is, for example, 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g, preferably 1 × 10 ¹⁷ to 10 ×. 10 ¹⁷ spins / g, particularly preferably 2 × 10 ¹⁷ to 5 × 10 ¹⁷ spins / g.

The radical generation amount at 320 ° C. of the composition of the present invention measured by electron spin resonance (ESR) is, for example, 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g, preferably 5 × 10 ¹⁶ to 10 ×. 10 ¹⁷ spins / g, particularly preferably 1 × 10 ¹⁷ to 5 × 10 ¹⁷ spins / g.

The radical generation amount at 400 ° C. of the composition of the present invention measured by electron spin resonance (ESR) is, for example, 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g, preferably 1 × 10 ¹⁷ to 10 ×. 10 ¹⁷ spins / g, particularly preferably 2 × 10 ¹⁷ to 10 × 10 ¹⁷ spins / g.

When the radical generation amount of the composition of the present invention exceeds the above range, it is difficult to prevent oxidative deterioration of the liquid crystal polymer due to peroxy radicals, so that it does not adversely affect melt moldability and polymer mechanical properties. A peroxy radical scavenger may be added. On the other hand, when the radical generation amount is below the above range, the lifetime of the peroxy radical is short, and the oxidation reaction derived from oxygen becomes active, so that the physical properties of the obtained solidified product are deteriorated (for example, toughness is reduced and embrittled) Etc.).

The composition of the present invention exhibits the effect of capturing peroxy radicals generated in the liquid crystal polymer by the ND particles. Therefore, even when exposed to a high temperature environment, an increase in the amount of radicals that cause oxidative degradation of the liquid crystal polymer is suppressed. The radical generation amount at 400 ° C. measured by electron spin resonance (ESR) is, for example, 3.0 times or less, preferably 2.5 times or less, particularly preferably 2.2 times the radical generation amount at 25 ° C. It is as follows. If the increase in the amount of radical generation exceeds the above range, the radical scavenging effect by the ND particles is insufficient (peroxy radical stabilization is insufficient), and the effect of preventing oxidative degradation of the liquid crystal polymer is difficult to obtain. Tend.

Since the composition of the present invention contains ND particles having an effect of scavenging peroxy radicals, it has excellent heat resistance, can be prevented from oxidative deterioration even when exposed to a high temperature environment, and has a temperature rising rate of 10 ° C./min. The weight reduction rate when the temperature is raised from 50 ° C. to 370 ° C. (in air) is, for example, 2.5% by weight or less, preferably less than 2.0% by weight, particularly preferably 1.8% by weight or less. .

Since the composition of the present invention contains ND particles having excellent heat resistance and antioxidation effect together with the liquid crystal polymer, the composition is heated at a temperature at which the liquid crystal polymer contained in the composition melts. However, the ND particles can exhibit an excellent antioxidant effect (or radical scavenging effect) without being decomposed, and exhibit the effect of scavenging radicals generated in the liquid crystal polymer. Thereby, the oxidative deterioration of the liquid crystal polymer due to radicals can be prevented, and yellowing of the liquid crystal polymer can be suppressed.

Accordingly, the composition of the present invention can be used, for example, as a printed circuit board mounting component, a connector / bobbin / optical pickup component case, a micromotor component or other electric / electronic component material; a compressor component, a shock absorber component or other automotive component material. It can be preferably used.

[Molded body]
The molded product of the present invention comprises a solidified product of the above composition. The molded body of the present invention can be produced, for example, by filling the melt of the above composition into a mold having a concave portion having a reverse shape of a desired shape, and then cooling to solidify the above composition. it can.

The above composition is melted by heating at a temperature equal to or higher than the melting point or softening point of the liquid crystal polymer contained therein. The composition is solidified by cooling to a temperature lower than the melting point or softening point of the liquid crystal polymer contained therein to form a solidified product.

The above composition can be molded by, for example, a melt molding method such as an injection molding method or an extrusion injection molding method.

The molded product thus obtained has a good hue and excellent appearance. Moreover, it is excellent in heat resistance, and it can suppress the fall of mechanical characteristics (toughness etc.) over a long period of time at the temperature lower than melting | fusing point or softening point of the liquid crystal polymer which comprises a molded object. That is, it withstands long-term use at high temperatures. Therefore, it can be suitably used for in-vehicle applications that require heat resistance.

Therefore, the molded article of the present invention is suitable as, for example, printed circuit board mounting parts, connector / bobbin / optical pickup parts cases, electric / electronic parts such as micro motor parts, automobile parts such as compressor parts, shock absorber parts, etc. Can be used.

[Antioxidant]
The antioxidant of the present invention is characterized by containing ND particles (preferably, the above-mentioned ND particles). The antioxidant of the present invention can be suitably used as an antioxidant for thermoplastic resins.

The antioxidant of the present invention is excellent in heat resistance, and the 5% weight loss temperature measured at a heating rate of 10 ° C./min (in air) is, for example, 450 ° C. or higher (eg, 450 to 600 ° C.), preferably 500 ° C. That's it. The 5% weight loss temperature can be measured by, for example, TG / DTA (simultaneous measurement of differential heat and thermogravimetry).

Since the antioxidant of the present invention is excellent in heat resistance, it has a high melting point (or softening temperature) of 250 ° C. or higher (eg 250 to 550 ° C.), preferably 300 ° C. or higher, particularly preferably 320 ° C. or higher. It can be used as an antioxidant for resins.

When the antioxidant of the present invention contains ND particles containing a carbonyl group as a surface functional group, an antioxidant for a liquid crystal polymer (particularly preferably a liquid crystal polyester and / or a liquid crystal polyester amide) among thermoplastic resins. It can be suitably used as an agent. Under a high temperature environment, the liquid crystal polymer undergoes oxidative degradation due to the decomposition of the ester bond or amide bond site by radicals. However, the ND particles capture peroxy radicals, thereby allowing the ester bond and the liquid crystal polymer to bond with each other. This is because oxidative degradation of the amide bond site is suppressed and stabilized.

The antioxidant of the present invention may contain other components in addition to the ND particles, but the proportion of the ND particles in the total amount of the antioxidant is, for example, 60% by weight or more, preferably 70% by weight or more. Particularly preferably, it is 80% by weight or more, and most preferably 90% by weight or more. The upper limit is 100% by weight. When content of ND particle | grains is less than the said range, there exists a tendency for the effect of this invention to become difficult to be acquired.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Preparation Example 1 (Preparation of liquid crystal polymer (LCP1))
After the following raw materials were charged into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C. and reacted at that temperature for 1 hour. Thereafter, the temperature is further raised to 325 ° C. over 3.5 hours, and then reduced to 5 Torr (ie, 667 Pa) over 20 minutes while distilling acetic acid, excess acetic anhydride, and other low-boiling components. Melt polymerization was performed. After the stirring torque reaches a predetermined value, nitrogen is introduced to change from the reduced pressure state to the normal pressure state, the liquid crystal polymer is discharged from the lower part of the polymerization vessel, the strand is pelletized, and the pellet-like liquid crystal polymer is removed. Obtained.
The obtained liquid crystal polymer had a melting point of 280 ° C. and a melt viscosity at 300 ° C. of 44.0 Pa · s.
4-hydroxybenzoic acid (HBA); 1660 g (73 mol%)
2-Hydroxy-6-naphthoic acid (HNA); 837 g (27 mol%)
Metal catalyst (potassium acetate catalyst); 165 mg
Acylating agent (acetic anhydride); 1714 g

Preparation Example 2 (Preparation of liquid crystal polymer (LCP2))
After the following raw materials were charged into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C. and reacted at that temperature for 1 hour. Thereafter, the temperature is further increased to 340 ° C. over 4.5 hours, and then the pressure is reduced to 10 Torr (ie, 1330 Pa) over 15 minutes, while acetic acid, excess acetic anhydride, and other low boiling points are distilled off. Melt polymerization was performed. After the stirring torque reaches a predetermined value, nitrogen is introduced to change from the reduced pressure state to the normal pressure state, the liquid crystal polymer is discharged from the lower part of the polymerization vessel, the strand is pelletized, and the pellet-like liquid crystal polymer is removed. Obtained. The obtained pellet-like liquid crystal polymer was further heat-treated at 300 ° C. for 2 hours under a nitrogen stream.
The obtained liquid crystal polymer had a melting point of 336 ° C. and a melt viscosity at 350 ° C. of 19.0 Pa · s.
4-hydroxybenzoic acid (HBA); 1380 g (60 mol%)
2-hydroxy-6-naphthoic acid (HNA); 157 g (5 mol%)
Terephthalic acid (TA); 484 g (17.5 mol%)
4,4′-dihydroxybiphenyl (BP); 388 g (12.5 mol%)
4-acetoxyaminophenol (APAP); 126 g (5 mol%)
110 mg of metal catalyst (potassium acetate catalyst)
Acylating agent (acetic anhydride); 1659 g

Preparation Example 3 (Preparation of liquid crystal polymer (LCP3))
After the following raw materials were charged into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C. and reacted at that temperature for 1 hour. Thereafter, the temperature is further raised to 360 ° C. over 5.5 hours, and then the pressure is reduced to 5 Torr (ie, 667 Pa) over 30 minutes, while acetic acid, excess acetic anhydride, and other low boiling points are distilled off. Melt polymerization was performed. After the stirring torque reaches a predetermined value, nitrogen is introduced to change from the reduced pressure state to the normal pressure state, the liquid crystal polymer is discharged from the lower part of the polymerization vessel, the strand is pelletized, and the pellet-like liquid crystal polymer is removed. Obtained. The obtained pellet-like liquid crystal polymer was further heat-treated at 300 ° C. for 8 hours under a nitrogen stream.
The obtained liquid crystal polymer had a melting point of 352 ° C. and a melt viscosity at 380 ° C. of 23.0 Pa · s.
4-hydroxybenzoic acid (HBA); 37 g (2 mol%)
2-hydroxy-6-naphthoic acid (HNA); 1218 g (48 mol%)
Terephthalic acid (TA); 560 g (25 mol%)
4,4′-dihydroxybiphenyl (BP); 628 g (25 mol%)
Metal catalyst (potassium acetate catalyst); 165 mg
Acylating agent (acetic anhydride); 1432 g

[Melting point]
After observing the endothermic peak temperature (Tm1) observed when the liquid crystal polymer was measured at room temperature from 20 ° C / min with a DSC manufactured by TA Instruments, the temperature was (Tm1 + 40) ° C for 2 minutes. After being held, it was once cooled to room temperature under a temperature drop condition of 20 ° C./min, and then the temperature of an endothermic peak observed when measured under a temperature rise condition of 20 ° C./min was measured again.

[Measurement of melt viscosity]
The melt viscosity of the liquid crystal polymer was measured in accordance with ISO11443 under the following conditions using an orifice having an inner diameter of 1 mm and a length of 20 mm using a capillograph (piston diameter: 10 mm) manufactured by Toyo Seiki Seisakusho.
Cylinder temperature:
When the liquid crystal polymer is LCP1: 300 ° C
When the liquid crystal polymer is LCP2: 350 ° C.
When the liquid crystal polymer is LCP3: 380 ° C.
Shear rate: 1000 sec ^-1

Example 1 (Synthesis of antioxidant (ND1))
A molded explosive with an electric detonator attached was placed inside a pressure-resistant container (made of iron, volume: 15 m ³ ) for detonation, and the container was sealed. As the explosive, 0.50 kg of a mixture of TNT and RDX (TNT / RDX = 50/50) was used. Next, the electric detonator was detonated, and the explosive was detonated in the container. Next, the container and its interior were cooled by being left at room temperature for 24 hours. After this cooling, the ND particle coarse product adhering to the inner wall of the container (including the ND particle aggregate and soot produced by the above detonation method) is scraped off with a spatula, The product was recovered.

The acid treatment was performed on the crude ND particle product obtained by performing the production process as described above a plurality of times. Specifically, a slurry obtained by adding 6 L of 10 wt% hydrochloric acid to 200 g of the ND particle crude product was heated at 85 to 100 ° C. for 1 hour under reflux under normal pressure conditions. It was. After cooling, the solid content (including ND particle aggregates and soot) was washed with water by decantation. The solid content was washed repeatedly with decantation until the pH of the precipitate reached 2 from the low pH side.

Next, oxidation treatment was performed. Specifically, 12 L of 98% by weight sulfuric acid aqueous solution and 1 L of 97% by weight nitric acid aqueous solution were added to the precipitate obtained through decantation after acid treatment (including ND particle aggregates) to form a slurry. Thereafter, the slurry was subjected to a heat treatment at 140 to 160 ° C. for 48 hours under reflux under normal pressure conditions. After cooling, the solid content (including ND particle aggregates) was washed with water by decantation. The supernatant liquid at the beginning of water washing was colored, and the solid contents were washed repeatedly by decantation until the supernatant liquid became transparent visually.

The precipitation liquid (including ND particle aggregates) obtained through decantation after the oxidation treatment was evaporated to dryness using an evaporator to obtain ND particle powder (ND1, D50 = 4.2 nm). In FT-IR, as shown in Figure 1, absorption peaks derived from a ketone group (C = O) in the surface functional groups 1730.15Cm ^-1 in the range of 1700 ~ 1850 cm ^-1, and the surface functional near 2915 cm ^-1 Absorption due to C—H in the group was seen. Absorption peak 1730.15Cm ^-1 was higher than the absorption peak around 2915 cm ^-1.

The 5% weight loss temperature of the ND particle powder (ND1) measured by TG / DTA (simultaneous measurement of differential heat and thermogravimetry) measured at a heating rate of 10 ° C./min (in air) was 523 ° C. It was.

Example 2 (Synthesis of antioxidant (ND2))
A heating oxidation process was performed using a gas atmosphere furnace (trade name “Gas Atmosphere Tube Furnace KTF045N1”, manufactured by Koyo Thermo System Co., Ltd.).
Specifically, after ND1 (4.5 g) obtained as described above is left in the core tube of the gas atmosphere furnace and nitrogen gas is continuously passed through the core tube at a flow rate of 1 L / min for 30 minutes. The flow gas was switched from nitrogen to a mixed gas of oxygen and nitrogen (oxygen concentration: 4% by volume), and the mixed gas was continuously passed through the core tube at a flow rate of 1 L / min. After switching to the mixed gas, the temperature in the furnace was raised to a heating set temperature of 400 ° C. The heating rate was 10 ° C./min from 380 ° C., which is 20 ° C. lower than the heating set temperature, and then 1 ° C./min from 380 ° C. to the heating set temperature. And the oxygen oxidation process was performed about ND particle powder in a furnace, maintaining the temperature conditions in a furnace at 400 degreeC. The processing time was 3 hours. As described above, ND particle powder (ND2) was obtained. The ratio (yield) of the amount of the ND particle powder after the heating oxidation step to the amount of the ND particle powder before being subjected to the heating oxidation step was 96%. In FT-IR, as shown in FIG. 2, an absorption peak derived from the ketone group (C═O) in the surface functional group was observed at 1776.44 cm ⁻¹ . No noticeable absorption peak was observed at 2800 to 3000 cm ⁻¹ .

Example 3 (Synthesis of antioxidant (ND3))
An ND particle powder (ND3) was obtained in the same manner as in Example 2 except that the heating set temperature in the heating oxidation step was changed to 475 ° C. The rate of temperature increase was 10 ° C./min from 455 ° C., which is 20 ° C. lower than the heating set temperature, and then 1 ° C./min from 455 ° C. to the heating set temperature.
The ratio (yield) of the amount of the ND particle powder after the heating oxidation step to the amount of the ND particle powder before being subjected to the heating oxidation step was 70%. In FT-IR, as shown in FIG. 3, an absorption peak derived from a ketone group (C═O) in the surface functional group was observed in the vicinity of 1800 cm ⁻¹ . No noticeable absorption peak was observed at 2800 to 3000 cm ⁻¹ .

Example 4 (Synthesis of antioxidant (ND4))
ND1 (4.5 g) obtained in the same manner as in Example 1 was left in the core tube of the gas atmosphere furnace, and nitrogen gas was continuously passed through the core tube at a flow rate of 1 L / min for 30 minutes. The flowing gas was switched from nitrogen to a mixed gas of hydrogen and nitrogen, and the mixed gas was continuously passed through the core tube at a flow rate of 1 L / min. The hydrogen concentration in the mixed gas is 2% by volume. After switching to the mixed gas, the temperature in the furnace was raised to a heating set temperature of 800 ° C. The heating rate was 10 ° C./min from 780 ° C., which is 20 ° C. lower than the heating set temperature, and then 1 ° C./min from 780 ° C. to the heating set temperature. And the hydrogen reduction process was performed about ND particle powder in a furnace, maintaining the temperature conditions in a furnace at 800 degreeC. The processing time was 5 hours. In this way, ND particle powder (ND4) was obtained.
The ratio (yield) of the amount of the ND particle powder after the heat reduction treatment to the amount of the ND particle powder before being subjected to the heat reduction treatment was 93%. In FT-IR, as shown in Figure 4, the absorption peak derived from C-H was observed at the surface functional group near 2940 cm ^-1, from a ketone group (C = O) in the surface functional group in the vicinity of 1710 cm ^-1 The absorption peak to be observed was hardly seen.

<FT-IR measurement>
A Fourier transform infrared spectrophotometer (trade name “FT-720”, manufactured by HORIBA, Ltd.) and heated vacuum stirring reflection (trade name “Heat Chamber Type—1000 ° C.”, manufactured by ST Japan Co., Ltd.) ) Was used to measure. In order to remove adsorbed water of ND particles, FT-IR measurement was performed after heating at 150 ° C. for 1 minute under a vacuum degree of 2 × 10 ⁻³ Pa.

Examples 5 to 10, Comparative Examples 1 to 3
Each component was mixed in the formulation shown in Table 1 below, and a composition was obtained by melting and kneading for 30 minutes at the following cylinder temperature using a plastmill manufactured by Toyo Seiki Seisakusho Co., Ltd., and the heat resistance of the resulting composition Was evaluated by the following method.
Cylinder temperature:
When LCP1 is contained as a liquid crystal polymer: 300 ° C.
When LCP2 is contained as a liquid crystal polymer: 350 ° C.
When LCP3 is contained as a liquid crystal polymer: 370 ° C.

<Weight reduction rate>
The obtained composition was heated from room temperature to 370 ° C. at 10 ° C. per minute under a flow of 60 mL / min dry air using a TA instrument thermogravimetric measuring device, and held for 2 hours after reaching 370 ° C. Then, the weight of the composition at room temperature and 370 ° C. was measured, and the weight reduction rate was calculated from the following formula.
Weight reduction rate = weight at 370 ° C./weight at room temperature × 100 (%)

<Measurement of radical generation by ESR>
50 mg of each of the compositions obtained in Example 8 and Comparative Example 1 was weighed out and placed in an ESR sample tube (quartz tube having an inner diameter of about 3.5 mmφ), and temperature rising ESR measurement was carried out by the following analysis method under the following conditions. . The results are shown in FIG.

Measuring device: JES-FE3T (manufactured by JEOL Ltd.)
Attached device: High temperature cavity (manufactured by JEOL Ltd.)
Measurement conditions Measurement temperature: Room temperature to set temperature Central magnetic field: Near 3278G Magnetic field sweep range: 500G
Modulation: 100kHz, 1G
Microwave: 9.21 GHz, 1 mW
Sweep time: 120s x 1time
Time constant: 100 ms
Number of data points: 4095 points
Cavity: TE011, cylindrical type

analysis method:
Using a device for high temperature measurement, changes in radical amount, g value, and line width with increasing temperature were examined. In this apparatus, the Mn marker was measured at the same time, and the g value was calculated and the detection sensitivity was corrected based on the marker signal.
Temperature rise ESR measurement (temperature rise rate: 10 ° C./min) was performed in an atmosphere in which synthetic air [21% O ₂ (N ₂ balance)] was circulated at 30 mL / min. The quantification of radicals was performed assuming that all unpaired electrons on carbon were localized electrons (paramagnetic substance). That is, since the signal intensity of the localized spin is proportional to the inverse of absolute temperature (1 / T), the signal intensity at each temperature is converted to the signal intensity at room temperature and compared with the signal intensity of the standard sample measured at room temperature. The number of unpaired electrons was calculated.

From Table 1, it was found that the composition of the present invention suppresses an increase in the amount of radical generation due to heat and suppresses oxidative degradation of the liquid crystal polymer.

Examples 11 to 13, Comparative Examples 4 to 5 (Preparation of molded bodies)
Each component was mixed with the formulation shown in the following Table 2, and melt-kneaded at the following cylinder temperature using a twin-screw extruder (trade name “TEX30α”, manufactured by Nippon Steel Works, Ltd.) to obtain a composition. . As milled glass fiber, PF70E001 manufactured by Nittobo Co., Ltd. was used.
Cylinder temperature:
When LCP1 is contained as a liquid crystal polymer, 300 ° C.
350 ° C when LCP2 is contained as the liquid crystal polymer

The obtained composition was molded under the following molding conditions using a molding machine (trade name “TR-100EH”, manufactured by Sodick Co., Ltd.) to obtain a molded body of 50 mm × 5 mm × 0.8 mm.
〔Molding condition〕
Mold temperature: 80 ℃
Injection speed: 200mm / sec
Holding pressure: 50 MPa

<Heat aging test>
The obtained molded body was allowed to stand at 260 ° C. for 2000 hours in an air atmosphere in a hot air thermostat (trade name “EPEC-18”, manufactured by Isuzu Seisakusho Co., Ltd.). Then, it took out from the tank and obtained the molded object after the heat aging test.

The molded body before and after the heat aging test is subjected to a three-point bending test under the following test conditions using a Tensilon universal testing machine (trade name “RTC-1325A”, manufactured by Orientec Co., Ltd.). The bending strain (%) until the molded body broke was calculated from the following formula (1), and the toughness retention was calculated from the following formula (2).
Breaking bending strain (%) = 600 × [deflection (mm)] × [test specimen thickness (mm)] / [distance between fulcrums (mm)] (1)
Toughness retention (%) = [Bending bending strain at 2000 hours of heat aging (%)] / [Bending bending strain at 0 hours of heat aging (%)] × 100 (2)

[Three-point bending test conditions]
Test speed: 1mm / min
Distance between fulcrums: 12.8mm
Indenter radius: 0.5 mm
Support base radius: 2mm

From Table 2, it can be seen that the molded products obtained in the examples are suppressed in deterioration of the resin due to oxidation, and the toughness of the resin is maintained even when exposed to a high temperature environment for a long time.

As a summary of the above, the configuration of the present invention and its variations are appended below.
[1] At least one liquid crystal polymer selected from liquid crystal polyester and liquid crystal polyester amide, and nanodiamond particles in a ratio of 0.001 to 5 parts by weight of nanodiamond particles to 100 parts by weight of the liquid crystal polymer. Containing composition.
[2] The composition according to [1], wherein the liquid crystal polymer has the following configuration.
In all structural units constituting the liquid crystal polymer,
The content of the structural unit represented by the formula (I) is 50 to 100 mol%,
The content of the structural unit represented by the formula (II) is 0 to 25 mol%,
The content of the structural unit represented by the formula (III) is 0 to 25 mol%. [3] The structural unit represented by the formula (I) and the formula (II) with respect to all the structural units constituting the liquid crystal polymer. The composition according to [1] or [2], wherein a proportion of the total content of the structural unit represented by formula (III) and the structural unit represented by formula (III) is 70 mol% or more.
[4] The composition according to any one of [1] to [3], wherein the proportion of the content of the structural unit represented by the formula (VI) with respect to all the structural units constituting the liquid crystal polymer is 30 mol% or less. Composition.
[5] The composition according to any one of [1] to [4], wherein the liquid crystal polymer has a melting point or softening point of 250 to 400 ° C.
[6] The composition according to any one of [1] to [5], wherein the following liquid crystal polymer has a melt viscosity of 5 to 100 Pa · s.
Melt viscosity of liquid crystal polymer: Melt viscosity measured at a shear rate of 1000 sec ^-1 at a cylinder temperature 10 to 30 ° C higher than the melting point or softening point of the liquid crystal polymer.
[7] The composition according to any one of [1] to [6], wherein the nanodiamond particles are detonated nanodiamond particles.
[8] The composition according to any one of [1] to [7], wherein the median diameter of the nanodiamond particles is 10 nm or less.
[9] The composition according to any one of [1] to [8], wherein the nanodiamond particles are nanodiamond particles having a carbonyl group on the surface.
[10] In the infrared absorption spectrum by Fourier transform infrared spectrophotometer of nanodiamond particles, the maximum peak of 1700 ~ 1850 cm ^-1 is greater than the maximum peak of ^{2800 ~ 3000cm -1, [1]} ~ [9] The composition as described in any one of these.
[11] The composition according to any one of [1] to [10], wherein a radical generation amount at 25 ° C. measured by an electron spin resonance method is 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g. object.
[12] The composition according to any one of [1] to [11], wherein a radical generation amount at 320 ° C. measured by an electron spin resonance method is 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g. object.
[13] The radical generation amount at 400 ° C. measured by an electron spin resonance method is 3.0 times or less the radical generation amount at 25 ° C., according to any one of [1] to [12] Composition.
[14] Any of [1] to [13], wherein the weight loss rate when heated from 50 ° C. to 370 ° C. at a temperature rising rate of 10 ° C./min in air is 2.5% by weight or less. The composition according to any one of the above.
[15] A molded article comprising a solidified product of the composition according to any one of [1] to [14].
[16] An antioxidant for thermoplastic resin, comprising nanodiamond particles.
[17] The antioxidant for thermoplastic resin according to [16], wherein the nanodiamond particles are detonated nanodiamond particles.
[18] The antioxidant for thermoplastic resins according to [16] or [17], wherein the median diameter of the nanodiamond particles is 10 nm or less.
[19] The antioxidant for thermoplastic resins according to any one of [16] to [18], wherein the nanodiamond particles are nanodiamond particles having a carbonyl group on the surface.
[20] In the infrared absorption spectrum by Fourier transform infrared spectrophotometer of nanodiamond particles, the maximum peak of 1700 ~ 1850 cm ^-1 it is greater than the maximum peak of ^{2800 ~ 3000cm -1, [16]} ~ [19] The antioxidant for thermoplastic resins as described in any one of these.
[21] The antioxidant for thermoplastic resins according to any one of [16] to [20], which is an antioxidant for thermoplastic resins having a melting point or softening temperature of 250 ° C. or higher.
[22] The oxidation for a thermoplastic resin according to any one of [16] to [21], wherein a 5% weight loss temperature measured at a heating rate of 10 ° C./min (in air) is 450 ° C. or higher. Inhibitor.
[23] The antioxidant for thermoplastic resins according to any one of [16] to [22], wherein the content of nanodiamond particles is 60% by weight or more of the total amount of the antioxidant.
[24] Use of nanodiamond particles as an antioxidant for thermoplastic resins.
[25] Use as an antioxidant for a thermoplastic resin according to [24], wherein the nanodiamond particles are detonated nanodiamond particles.
[26] Use as an antioxidant for thermoplastic resins according to [24] or [25], wherein the median diameter of the nanodiamond particles is 10 nm or less.
[27] The use as an antioxidant for thermoplastic resins according to any one of [24] to [26], wherein the nanodiamond particles are nanodiamond particles having a carbonyl group on the surface.
[28] In the infrared absorption spectrum by Fourier transform infrared spectrophotometer of nanodiamond particles, the maximum peak of 1700 ~ 1850 cm ^-1 it is greater than the maximum peak of ^{2800 ~ 3000cm -1, [24]} ~ [27] Use as an antioxidant for thermoplastic resins according to any one of the above.
[29] The use as an antioxidant for thermoplastic resins according to any one of [24] to [28], wherein the nanodiamond particles are detonated nanodiamond particles.
[30] Use as an antioxidant for thermoplastic resins according to any one of [24] to [29], wherein the median diameter of the nanodiamond particles is 10 nm or less.
[31] Use as an antioxidant for thermoplastic resins according to any one of [24] to [30], wherein the nanodiamond particles are nanodiamond particles having a carbonyl group on the surface.
[32] In the infrared absorption spectrum by Fourier transform infrared spectrophotometer of nanodiamond particles, the maximum peak of 1700 ~ 1850 cm ^-1 it is greater than the maximum peak of ^{2800 ~ 3000cm -1, [24]} ~ [31] Use as an antioxidant for thermoplastic resins according to any one of the above.
[33] A method for producing an antioxidant for thermoplastic resin, comprising producing an antioxidant for thermoplastic resin using nanodiamond particles.

Claims (9)

1. A composition comprising at least one liquid crystal polymer selected from liquid crystal polyester and liquid crystal polyester amide, and nanodiamond particles in a proportion of 0.001 to 5 parts by weight of nanodiamond particles with respect to 100 parts by weight of the liquid crystal polymer. object.
2. The composition according to claim 1, wherein the liquid crystal polymer has the following constitution.
   In all structural units constituting the liquid crystal polymer,
   The content of the structural unit represented by the following formula (I) is 50 to 100 mol%,
   The content of the structural unit represented by the following formula (II) is 0 to 25 mol%,
   The content of the structural unit represented by the following formula (III) is 0 to 25 mol%
   

   

   (Wherein Ar ¹ to Ar ³ are the same or different and may have at least one substituent selected from a halogen atom, an alkyl group, and an aryl group, a phenylene group, a naphthylene group, or biphenylylene) And X and Y are the same or different and represent —O— or —NH—.
3. The composition according to claim 1 or 2, wherein the nanodiamond particles are detonation nanodiamond particles.
4. In the infrared absorption spectrum by Fourier transform infrared spectrophotometer of nanodiamond particles, the maximum peak of 1700 ~ 1850 cm ^-1 is greater than the maximum peak of 2800 ~ 3000 cm ^-1, any one of claims 1 to 3, A composition according to 1.
5. The composition according to any one of claims 1 to 4, wherein a radical generation amount at 320 ° C measured by an electron spin resonance method is 2 × 10 ¹⁶ to 2 × 10 ¹⁸ spins / g.
6. 6. The composition according to claim 1, wherein a radical generation amount at 400 ° C. measured by an electron spin resonance method is 3.0 times or less of a radical generation amount at 25 ° C.
7. A molded body comprising a solidified product of the composition according to any one of claims 1 to 6.
8. An antioxidant for thermoplastic resin containing nanodiamond particles.
9. The antioxidant for thermoplastic resins according to claim 8, wherein a 5% weight reduction temperature measured at a temperature rising rate of 10 ° C / min (in air) is 450 ° C or higher.

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