Liquid crystal polymer composition, liquid crystal polymer molded body, camera module, and electrical and electronic equipment

Abstract

Provided is a liquid crystal polymer composition that, in relation to sliding between a liquid crystal polymer molded body thereof and a metal material, is capable of reducing the friction coefficient to a low level both at an early stage of the sliding and after the sliding has been repeated multiple times.　This liquid crystal polymer composition comprises a liquid crystal polymer (A), a first inorganic filler (B1), a second inorganic filler (B2), and a solid lubricant (C). A treatment layer composed of a hydrophilic surface treatment agent is provided on the surface of the first inorganic filler (B1), and a treatment layer composed of a hydrophobic surface treatment agent is provided on the surface of the second inorganic filler (B2).

Description

Liquid crystal polymer composition, liquid crystal polymer molded article, camera module, and electrical / electronic device

[0001] The present invention relates to a liquid crystal polymer composition, a liquid crystal polymer molded article using the liquid crystal polymer composition, and a camera module and an electric / electronic device using the liquid crystal polymer molded article.

[0002] Liquid crystal polymers (hereinafter sometimes referred to as "LCPs") are characterized by excellent flow properties and self-orientation properties not found in other resins, and are excellent in mechanical strength, moldability, dimensional accuracy, chemical resistance, moisture resistance, electrical properties, etc. Liquid crystal polymers are used, for example, primarily in molding thin-walled parts that require mechanical strength, and are also widely used in a variety of parts for various electrical and electronic components, machinery and robotics, automotive, etc. Furthermore, because liquid crystal polymers have excellent heat resistance and thin-wall moldability, their use in electronic components such as precision instruments is being considered, for example, for use in camera modules.

[0003] Camera modules are incorporated into many smartphone models, and camera modules with actuator mechanisms such as autofocus (AF) mechanisms and optical image stabilization (OIS) mechanisms are widely used. In recent years, as the number of cameras installed in a single smartphone has increased, new actuator mechanisms, such as those integrating AF and OIS mechanisms, are being considered to enable the inexpensive manufacture of camera modules. Camera module manufacturers have also begun developing mechanisms that perform focus adjustment by sliding plastic and metal parts.

[0004] In a mechanism that performs focus adjustment by sliding a plastic part against a metal part, the plastic part and the metal part rub against each other, so the material of the plastic part is required to have excellent low-friction characteristics, i.e., a low coefficient of friction. However, plastic materials generally tend to have poor friction characteristics when rubbed against other materials, i.e., a high coefficient of friction, and liquid crystal polymers are no exception.

[0005] If a plastic material with poor friction properties is used in the mechanism that performs focus adjustment, the sliding action will not proceed smoothly, and focus adjustment will take a long time or will not be performed properly, leading to malfunctions.In addition, because the camera function of a smartphone is used repeatedly, the material used must be one that can exhibit excellent low friction properties over a long period of time.

[0006] As a method for improving the sliding properties of a liquid crystal polymer, a method of adding a sliding additive such as polytetrafluoroethylene (hereinafter sometimes referred to as "PTFE") or graphite to the liquid crystal polymer is generally known, but this method may not provide sufficient sliding properties. For example, Patent Document 1 discloses that by using polytetrafluoroethylene and barium sulfate in addition to a liquid crystal polymer, a liquid crystal polymer composition can be provided that can further improve the sliding properties compared to when polytetrafluoroethylene is added alone to the liquid crystal polymer.

[0007] International Publication No. 2021 / 117607

[0008] However, the liquid crystal polymer composition disclosed in Patent Document 1 tends to have a tendency that the coefficient of friction increases significantly at the beginning of sliding, particularly with respect to a metal material, and then gradually decreases, and there are cases where the large fluctuation in the coefficient of friction at the beginning of sliding cannot be sufficiently suppressed. On the other hand, if an attempt is made to suppress the coefficient of friction at the beginning of sliding low, there is a problem that it is difficult to sufficiently suppress the coefficient of friction after repeated sliding.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a liquid crystal polymer composition that can keep the coefficient of friction low when a liquid crystal polymer molded body slides against a metal material both at the beginning of sliding and after repeated sliding operations, a liquid crystal polymer molded body using the liquid crystal polymer composition, and a camera module and an electrical / electronic device using the liquid crystal polymer molded body.

[0010] The present invention provides the following liquid crystal polymer composition, a liquid crystal polymer molded article using the liquid crystal polymer composition, and a camera module and an electric / electronic device using the liquid crystal polymer molded article.

[0011] Item 1. A liquid crystal polymer composition comprising a liquid crystal polymer (A), a first inorganic filler (B1), a second inorganic filler (B2), and a solid lubricant (C), wherein a treatment layer formed of a hydrophilic surface treatment agent is provided on a surface of the first inorganic filler (B1), and a treatment layer formed of a hydrophobic surface treatment agent is provided on a surface of the second inorganic filler (B2).

[0012] Item 2. The liquid crystal polymer composition according to item 1, wherein the hydrophilic surface treatment agent has a surface free energy of more than 50 mN / m, and the hydrophobic surface treatment agent has a surface free energy of less than 50 mN / m.

[0013] Item 3. The liquid crystal polymer composition according to item 1 or 2, wherein the liquid crystal polymer (A) has a melting point of 150°C to 310°C.

[0014] Item 4. The liquid crystal polymer composition according to any one of Items 1 to 3, further comprising barium sulfate (D).

[0015] Item 5. The liquid crystal polymer composition according to any one of Items 1 to 4, wherein the liquid crystal polymer (A) is at least one of a liquid crystal polyester and a liquid crystal polyester amide.

[0016] Item 6. The liquid crystal polymer composition according to any one of items 1 to 5, wherein the total content of the first inorganic filler (B1) and the second inorganic filler (B2) is 5% by mass to 50% by mass, based on 100% by mass of the total amount of components contained in the liquid crystal polymer composition.

[0017] Item 7. The liquid crystal polymer composition according to any one of Items 1 to 6, wherein the first inorganic filler (B1) is a fibrous particle or a non-fibrous particle.

[0018] Item 8. The liquid crystal polymer composition according to any one of Items 1 to 7, wherein the second inorganic filler (B2) is a fibrous particle or a non-fibrous particle.

[0019] Item 9: The liquid crystal polymer composition according to any one of items 1 to 8, wherein the mass ratio of the first inorganic filler (B1) to the second inorganic filler (B2) is 1:4 to 4:1.

[0020] Item 10. The liquid crystal polymer composition according to any one of items 1 to 9, wherein the content of the solid lubricant (C) is 1% by mass to 30% by mass, based on 100% by mass of the total amount of components contained in the liquid crystal polymer composition.

[0021] Item 11. The liquid crystal polymer composition according to any one of items 1 to 10, which is used in a camera module.

[0022] Item 12. A liquid crystal polymer molded article, which is a molded article of the liquid crystal polymer composition according to any one of items 1 to 11.

[0023] Item 13. The liquid crystal polymer molded article according to Item 12, which is a sliding member.

[0024] Item 14. A camera module comprising the liquid crystal polymer molded article according to item 12 or 13.

[0025] Item 15. An electric / electronic device comprising the liquid crystal polymer molded article according to item 12 or 13, and having a camera function.

[0026] According to the present invention, it is possible to provide a liquid crystal polymer composition that can keep the coefficient of friction low both at the beginning of sliding and after repeated sliding between a liquid crystal polymer molded body and a metal material, a liquid crystal polymer molded body using the liquid crystal polymer composition, and a camera module and an electrical / electronic device using the liquid crystal polymer molded body.

[0027] Hereinafter, an example of a preferred embodiment of the present invention will be described. However, the following embodiment is merely an example, and the present invention is not limited to the following embodiment.

[0028] <Liquid Crystal Polymer Composition> The liquid crystal polymer composition of the present invention contains a liquid crystal polymer (A), a first inorganic filler (B1), a second inorganic filler (B2), and a solid lubricant (C). The liquid crystal polymer composition of the present invention may further contain barium sulfate (D), a particulate carbon material (E), and other additives, as needed.

[0029] The surface of the first inorganic filler (B1) is provided with a treatment layer made of a hydrophilic surface treatment agent, and the surface of the second inorganic filler (B2) is provided with a treatment layer made of a hydrophobic surface treatment agent.

[0030] The inventor of the present invention has found that by using the liquid crystal polymer composition that contains the first inorganic filler (B1) that is formed with the treatment layer of hydrophilic surface treatment agent in addition to the liquid crystal polymer (A) and the solid lubricant (C), and the second inorganic filler (B2) that is formed with the treatment layer of hydrophobic surface treatment agent, it is surprising that when the liquid crystal polymer molding and metal material slide, it can suppress the friction coefficient low in both the initial stage of sliding and after repeated sliding times.It should be noted that the mechanism that obtains the effect of the present invention is not clear, but it is considered as follows.

[0031] Since the liquid crystal polymer composition of the present invention contains the second inorganic filler (B2) provided with a treatment layer formed of a hydrophobic surface treatment agent, it is thought that in the initial stage of sliding between the liquid crystal polymer molded body and the metal material, no resistance is generated between the treatment layer formed of the hydrophobic surface treatment agent and the metal material, thereby making it possible to keep the friction coefficient low.

[0032] In addition, the liquid crystal polymer composition of the present invention contains the first inorganic filler (B1) that is provided with the treatment layer that is made up of hydrophilic surface treatment agent, so when the sliding of liquid crystal polymer molding and metal material is repeated, the wear powder that contains part of hydrophilic surface treatment agent is adhered to the metal material surface, and when the sliding number of times is repeated, it is thought that the adhered wear powder is stretched and forms a lubricating film.This lubricating film is strongly adhered to the metal material surface, and is difficult to peel off even when the sliding number of times is repeated, so it is thought that even when the sliding number of times is repeated, the friction coefficient can be suppressed to a low level.

[0033] Thus, according to the liquid crystal polymer composition of the present invention, the coefficient of friction can be kept low when a liquid crystal polymer molded article slides against a metal material, both at the beginning of the sliding and after repeated sliding.

[0034] Each of the constituent components of the liquid crystal polymer composition of the present invention will be described below.

[0035] <Constituents of Liquid Crystal Polymer Composition> (Liquid Crystal Polymer (A)) The liquid crystal polymer composition of the present invention contains a liquid crystal polymer (A).

[0036] The liquid crystal polymer (A) refers to a melt-processable polymer capable of forming an optically anisotropic molten phase, and is not particularly limited as long as it is a polymer known in the art as a thermotropic liquid crystal polymer. The optically anisotropic molten phase can be confirmed by a conventional polarization inspection method using crossed polarizers.

[0037] The liquid crystal polymer (A) has a molecular shape that is long and thin, flat, and has a molecular chain (referred to as a "mesogen group") with high rigidity along the long chain of the molecule. The liquid crystal polymer (A) may have a mesogen group in either or both of the polymer main chain and the side chain, but if the obtained liquid crystal polymer molded article is required to have higher heat resistance, it is preferable that the polymer main chain has a mesogen group.

[0038] Examples of the liquid crystal polymer (A) include liquid crystal polyester, liquid crystal polyester amide, liquid crystal polyester ether, liquid crystal polyester carbonate, liquid crystal polyester imide, and liquid crystal polyamide. Among these, from the viewpoint of obtaining a liquid crystal polymer molded article having superior strength, the liquid crystal polymer (A) is preferably liquid crystal polyester, liquid crystal polyester amide, or liquid crystal polyamide. Furthermore, from the viewpoint of obtaining a liquid crystal polymer molded article having lower water absorption, the liquid crystal polymer (A) is preferably liquid crystal polyester or liquid crystal polyester amide, and more preferably liquid crystal polyester.

[0039] As the liquid crystal polymer (A), for example, liquid crystal polymers such as (A1) to (A6) described in WO 2021 / 117607 may be used.

[0040] The liquid crystal polymer (A) used in the present invention preferably has a melting point of 150°C to 310°C, more preferably 200°C to 310°C, and even more preferably 250°C to 310°C. When the melting point of the liquid crystal polymer (A) is equal to or higher than the lower limit, deformation, discoloration, etc. of the resulting liquid crystal polymer molded article can be further suppressed, and the heat resistance of the liquid crystal polymer molded article can be further improved. On the other hand, when the melting point of the liquid crystal polymer (A) is equal to or lower than the upper limit, the tensile adhesive strength and weld strength of the resulting liquid crystal polymer molded article can be further improved. The melting point can be measured in accordance with JIS-K7121.

[0041] The liquid crystal polymer (A) has a melt viscosity of 1.0×10 measured at a temperature 20° C. to 40° C. higher than the melting point. ３ mPa・s~1.0×10 ５For example, in liquid crystal polymers, due to differences in heat distortion temperature, those with a deflection temperature under load of 260°C or more are called Type I, and those with a deflection temperature under load of 210°C or more and less than 260°C are called Type II. The melt viscosity of Type I liquid crystal polymers can be measured at a temperature 30°C higher than the melting point, and that of Type II liquid crystal polymers can be measured at a temperature 40°C higher than the melting point. The melt viscosity is measured using a capillary rheometer by passing an orifice with a diameter of 1 mm and a length of 10 mm through a 1.0 x 10 ３ sec －１ The viscosity can be obtained by measuring the viscosity of the solution as it passes through a shear rate of 100 psi.

[0042] The form of the liquid crystal polymer (A) is not particularly limited as long as it can be melt-kneaded, and for example, any of powder, granules, and pellets can be used.

[0043] The content of the liquid crystal polymer (A) in the liquid crystal polymer composition of the present invention is preferably 10% by mass to 70% by mass, more preferably 30% by mass to 70% by mass, and even more preferably 40% by mass to 70% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition (total amount of components contained in the liquid crystal polymer composition).

[0044] (First Inorganic Filler (B1) and Second Inorganic Filler (B2)) The liquid crystal polymer composition of the present invention contains a first inorganic filler (B1) and a second inorganic filler (B2).

[0045] The main body (excluding the treated layer) of the first inorganic filler (B1) and the second inorganic filler (B2) is, for example, a particulate inorganic filler. The particle shape of the inorganic filler is not particularly limited as long as it improves the strength and rigidity of the resulting liquid crystal polymer molded article. For example, fibrous particles or non-fibrous particles can be used as the inorganic filler. In particular, the first inorganic filler (B1) is preferably fibrous particles or non-fibrous particles, and the second inorganic filler (B2) is preferably fibrous particles or non-fibrous particles. The particle shape of the inorganic filler can be analyzed, for example, by observation with a scanning electron microscope (SEM).

[0046] In the present invention, fibrous particles refer to particles in which the longest side of the rectangular parallelepiped having the smallest volume among the rectangular parallelepipeds circumscribing the particle (circumscribing rectangular parallelepiped) is defined as the major axis L, the next longest side as the minor axis B, and the shortest side as the thickness T (B > T), where L / B and L / T are both 3 or more, and the major axis L corresponds to the fiber length and the minor axis B corresponds to the fiber diameter. Non-fibrous particles refer to particles in which L / B is 3 or less. Plate-like particles are preferred as non-fibrous particles. Plate-like particles refer to non-fibrous particles in which L / T is 3 or more. Note that plate-like includes not only plate-like but also flake-like, scale-like, etc.

[0047] Specific examples of the fibrous particles include inorganic fibers such as carbon fibers, glass fibers, potassium titanate fibers, wollastonite fibers, aluminum borate fibers, magnesium borate fibers, xonotlite fibers, zinc oxide fibers, basic magnesium sulfate fibers, alumina fibers, silicon carbide fibers, and boron fibers; and organic fibers such as aramid fibers and polyphenylene benzoxazole (PBO) fibers, with inorganic fibers being preferred. These fibrous particles may be used alone or in combination.

[0048] From the viewpoint of further improving the mechanical strength and sliding properties of the resulting liquid crystal polymer molded article, the fibrous particles are preferably particles having a Mohs hardness of 2.5 or more and 5 or less, and are more preferably at least one of potassium titanate fibers and wollastonite fibers. Mohs hardness is an index representing the hardness of a substance, and a substance that is scratched when two minerals are rubbed against each other has a lower hardness.

[0049] From the viewpoint of further improving the mechanical strength and sliding properties of the resulting liquid crystal polymer molded article, the average fiber length of the fibrous particles is preferably 1 μm to 300 μm, more preferably 1 μm to 200 μm, even more preferably 3 μm to 100 μm, and particularly preferably 3 μm to 50 μm. The average aspect ratio of the fibrous particles is preferably 3 to 200, more preferably 3 to 100, even more preferably 3 to 50, and particularly preferably 3 to 40.

[0050] A wide variety of conventional potassium titanate fibers can be used, including, for example, potassium tetratitanate fiber, potassium hexatitanate fiber, and potassium octatitanate fiber. The dimensions of the potassium titanate fibers are not particularly limited as long as they are within the range of the dimensions of the fibrous particles described above, but the average fiber length is preferably 1 μm to 50 μm, more preferably 3 μm to 30 μm, and even more preferably 3 μm to 20 μm. The average fiber diameter of the potassium titanate fibers is preferably 0.01 μm to 1 μm, more preferably 0.05 μm to 0.8 μm, and even more preferably 0.1 μm to 0.7 μm. The average aspect ratio of the potassium titanate fibers is preferably 10 or more, more preferably 10 to 100, and even more preferably 15 to 35.

[0051] Wollastonite fiber is an inorganic fiber made of calcium metasilicate. The dimensions of the wollastonite fiber are not particularly limited as long as they are within the range of the dimensions of the fibrous particles described above, but the average fiber length is preferably 5 μm to 180 μm, more preferably 7 μm to 100 μm, and even more preferably 9 μm to 40 μm. The average fiber diameter of the wollastonite fiber is preferably 0.1 μm to 15 μm, more preferably 1 μm to 10 μm, and even more preferably 2 μm to 7 μm. The average aspect ratio of the wollastonite fiber is preferably 3 or more, more preferably 3 to 30, and even more preferably 3 to 15.

[0052] The average fiber length and average fiber diameter can be measured by observation with a scanning electron microscope (SEM), and the average aspect ratio (average fiber length / average fiber diameter) can be calculated from the average fiber length and average fiber diameter. For example, a plurality of fibrous particles are photographed with a scanning electron microscope (SEM), and 300 fibrous particles are randomly selected from the observation image, and their fiber lengths and fiber diameters are measured. The average fiber length can be calculated by integrating all the fiber lengths and dividing by the number of particles, and the average fiber diameter can be calculated by integrating all the fiber diameters and dividing by the number of particles.

[0053] Specific examples of non-fibrous particles include mica, sericite, illite, talc, kaolinite, montmorillonite, boehmite, smectite, vermiculite, titanium dioxide, potassium titanate, lithium potassium titanate, magnesium potassium titanate, boehmite, etc. These non-fibrous particles may be used alone or in combination.

[0054] From the viewpoint of further improving the mechanical strength and sliding properties of the resulting liquid crystal polymer molded article, the non-fibrous particles are preferably particles having a Mohs hardness of 1 or more and less than 2.5, and more preferably talc.

[0055] Talc is a hydrous magnesium silicate in terms of chemical composition, and is generally represented by the chemical formula 4SiO ２ ・3MgO・2H ２ It is represented by O and is usually a scaly particle with a layered structure. These talcs can also be used as commercially available products.

[0056] The average particle size of the non-fibrous particles is preferably 1 μm to 50 μm, more preferably 3 μm to 30 μm, and even more preferably 3 μm to 25 μm, from the viewpoint of further improving the mechanical strength and sliding properties of the resulting liquid crystal polymer molded article.

[0057] The average particle size of the non-fibrous particles can be measured by a laser diffraction / scattering method. Specifically, the average particle size of the non-fibrous particles is the particle size at 50% cumulative volume in the particle size distribution measured by the laser diffraction / scattering method (volume-based cumulative 50% particle size), i.e., D ５０ (median diameter). This volume-based cumulative 50% particle diameter (D ５０ ) is the particle size at which the cumulative value reaches 50% when the particle size distribution is calculated on a volume basis and the number of particles is counted from the smallest particle size on a cumulative curve with the total volume set to 100%.

[0058] In the present invention, a treatment layer composed of a hydrophilic surface treatment agent is provided on the surface of the first inorganic filler (B1). Furthermore, a treatment layer composed of a hydrophobic surface treatment agent is provided on the surface of the second inorganic filler (B2). In the first inorganic filler (B1) and the second inorganic filler (B2), the treatment layer may cover a portion of the surface of the inorganic filler's main body, as long as the effects of the present invention are achieved. The treatment layer preferably covers 50% or more, and more preferably 80% or more, of the surface of the inorganic filler's main body. However, it is even more preferable for the treatment layer to cover the entire inorganic filler's main body.

[0059] The surface free energy of the hydrophilic surface treatment agent constituting the treatment layer of the first inorganic filler (B1) is preferably greater than 50 mN / m. The surface free energy of the hydrophilic surface treatment agent is preferably greater than 50 mN / m, more preferably 52 mN / m or greater, and preferably 100 mN / m or less, more preferably 95 mN / m or less, even more preferably 90 mN / m or less, still more preferably 85 mN / m or less, even more preferably 80 mN / m or less, still more preferably 75 mN / m or less, and particularly preferably 70 mN / m or less.

[0060] The surface free energy of the hydrophobic surface treatment agent constituting the treatment layer of the second inorganic filler (B2) is preferably less than 50 mN / m. The surface free energy of the hydrophobic surface treatment agent is preferably 5 mN / m or more, more preferably 10 mN / m or more, even more preferably 15 mN / m or more, particularly preferably 17 mN / m or more, and is preferably 50 mN / m or less, more preferably less than 50 mN / m, even more preferably 45 mN / m or less, even more preferably 40 mN / m or less, even more preferably 35 mN / m or less, particularly preferably 30 mN / m or less.

[0061] The surface free energy can be determined by uniformly applying a surface treatment agent diluted 10 times with methanol to a glass plate, heating the plate at 85°C for 1 hour, and then heat-treating the plate at 110°C for 1 hour, and then measuring the static contact angle between the two liquids, water and decane, to calculate the surface free energy of the surface on which the surface treatment agent is applied.

[0062] Examples of the hydrophilic surface treatment agent constituting the treatment layer of the first inorganic filler (B1) include amino-based silane coupling agents and epoxy-based silane coupling agents.

[0063] Examples of amino-based silane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane.

[0064] Examples of epoxy-based silane coupling agents include 3-glycidyloxypropyltrimethoxysilane (γ-glycidoxypropyltrimethoxysilane), 3-glycidyloxypropyl(dimethoxy)methylsilane (γ-glycidoxypropyl(dimethoxy)methylsilane), diethoxy(3-glycidyloxypropyl)methylsilane, triethoxy(3-glycidyloxypropyl)silane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0065] Among these, the hydrophilic surface treatment agent is preferably 3-aminopropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane (γ-glycidoxypropyltrimethoxysilane), or 3-(2-aminoethylamino)propyltrimethoxysilane, and more preferably 3-glycidyloxypropyltrimethoxysilane (γ-glycidoxypropyltrimethoxysilane). These hydrophilic surface treatment agents may be used alone or in combination of two or more.

[0066] The hydrophobic surface treatment agent that constitutes the treatment layer of the second inorganic filler (B2) can be, for example, a hydrophobic silane coupling agent.The hydrophobic silane coupling agent can be any agent that has an essentially hydrophobic functional group such as an alkyl group or an aryl group, and a hydrolyzable functional group that generates a group that can react with the hydrophilic group on the surface of the inorganic filler body.The representative example of such a hydrophobic silane coupling agent can be, for example, an alkoxysilane represented by the following general formula (I):

[0067] R １ ｎ Si(OR ２ ) ４－ｎ ... Formula (I) [In general formula (I), n represents an integer selected from 1 to 3, and R １ represents an alkyl group, an alkenyl group, or an aryl group, and these groups may have a substituent. １ When there are a plurality of R, they may be the same or different. ２ represents an alkyl group, which may have a substituent; R ２ When there are a plurality of groups, they may be the same or different.

[0068] R １ Examples of the alkyl group represented by the formula (I) include alkyl groups such as heptyl, octyl, nonyl, decyl, dodecyl, hexadecyl, octadecyl, and icosyl. The number of carbon atoms in the alkyl group is preferably 6 or more, and more preferably 8 or more. The upper limit of the number of carbon atoms in the alkyl group is not particularly limited, but can be, for example, 20 or less.

[0069] These alkyl groups may have a cyclic structure or a branched structure. In general, the greater the number of carbon atoms in the linear chain of an alkyl group, the greater the degree of hydrophobicity. The alkyl group may have a substituent, as described below, at any position.

[0070] R １Examples of the alkenyl group represented by the formula (I) include a vinyl group and a butenyl group. These may have a cyclic structure or a branched structure. The alkenyl group may have a substituent, which will be described later, at any position.

[0071] R １ Examples of the aryl group represented by the formula (I) include a phenyl group, a naphthyl group, etc. The aryl group may have a substituent, which will be described later, at any position.

[0072] R １ The groups represented by the formula (I) may each have a substituent, as long as it does not impair the hydrophobicity. Examples of the substituent include hydrophobic substituents such as a fluorine atom and a (meth)acryloxy group.

[0073] Furthermore, R １ The alkyl group represented by the formula (I) may have the above-mentioned aryl group as a hydrophobic substituent. １ The aryl group represented by the formula (I) may have an alkyl group as a hydrophobic substituent.

[0074] R ２ Examples of the alkyl group represented by the formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a hexadecyl group, an octadecyl group, and an icosyl group. ２ ) is a hydrolyzable group, so from the viewpoint of hydrolysis, R ２ is preferably a lower alkyl group having 4 or less carbon atoms, more preferably an ethyl group or a methyl group, and even more preferably a methyl group.

[0075] n represents any integer selected from 1 to 3. n is preferably 1 from the viewpoint of further increasing the reactivity and hydrophobicity between the surface of the main body of the inorganic filler and the treatment layer.

[0076] Specific examples of the alkoxysilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, heptyltrimethoxysilane, octyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, icosyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, hexyltriethoxysilane, heptyltriethoxysilane, octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, hexadecyltriethoxysilane, octadecyltriethoxysilane, icosyltriethoxysilane, and phenyltriethoxysilane. Among these, the hydrophobic surface treatment agent is preferably heptyltrimethoxysilane, octyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, icosyltrimethoxysilane, heptyltriethoxysilane, octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, hexadecyltriethoxysilane, octadecyltriethoxysilane, or icosyltriethoxysilane, and more preferably decyltrimethoxysilane or hexadecyltrimethoxysilane. These hydrophobic surface treatment agents may be used alone or in combination of two or more.

[0077] As a method for forming a treatment layer consisting of a surface treatment agent on the surface of the main body (inorganic filler) constituting the first inorganic filler (B1) and the second inorganic filler (B2), a known surface treatment method can be used, but as a method for forming a coupling agent in advance on the surface of the inorganic filler, a dry method or a wet method can be used, and either method can be used.

[0078] The surface treatment is carried out, for example, by a dry method in which the inorganic filler is charged into a device capable of high-speed stirring, such as a Henschel mixer, and the surface treatment agent (if it is a liquid) or a solution in which the surface treatment agent is dissolved in a solvent that promotes hydrolysis (for example, water, alcohol, or a mixed solvent of these) is sprayed onto the inorganic filler while stirring.

[0079] The amount of hydrophilic surface treatment agent used when treating the surface of the main body of the inorganic filler constituting the first inorganic filler (B1) is not particularly limited. In the case of a dry method, for example, a solution of the hydrophilic surface treatment agent may be sprayed so that the amount of the surface treatment agent is preferably 0.1% by mass to 20% by mass, more preferably 0.1% by mass to 10% by mass, more preferably 0.3% by mass to 5% by mass, and even more preferably 0.5% by mass to 3% by mass, relative to 100% by mass of the first inorganic filler (B1).

[0080] The amount of hydrophobic surface treatment agent used when treating the surface of the main body of the inorganic filler constituting the second inorganic filler (B2) is not particularly limited. In the case of a dry method, for example, a solution of the hydrophobic surface treatment agent may be sprayed so that the amount of the surface treatment agent is preferably 0.1% by mass to 20% by mass, more preferably 0.1% by mass to 10% by mass, more preferably 0.3% by mass to 5% by mass, and even more preferably 0.5% by mass to 3% by mass, relative to 100% by mass of the second inorganic filler (B2).

[0081] The total content of the first inorganic filler (B1) and the second inorganic filler (B2) in the liquid crystal polymer composition of the present invention is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 45% by mass, and even more preferably 15% by mass to 40% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition.

[0082] When the total content of the first inorganic filler (B1) and the second inorganic filler (B2) is within the above range, the coefficient of friction can be kept lower during sliding between the liquid crystal polymer molded body and the metal material, both at the initial stage of sliding and after repeated sliding.

[0083] In the liquid crystal polymer composition of the present invention, the mass ratio of the first inorganic filler (B1) to the second inorganic filler (B2) (first inorganic filler (B1):second inorganic filler (B2)) is preferably 1:4 to 4:1, more preferably 3:7 to 7:3, and even more preferably 4:6 to 6:4.

[0084] When the mass ratio (first inorganic filler (B1):second inorganic filler (B2)) is within the above range, the coefficient of friction can be kept lower during sliding between the liquid crystal polymer molded body and the metal material, both at the initial stage of sliding and after repeated sliding.

[0085] The content of the first inorganic filler (B1) is preferably 5% by mass to 40% by mass, more preferably 5% by mass to 30% by mass, and even more preferably 5% by mass to 20% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition.

[0086] The content of the second inorganic filler (B2) is preferably 5% by mass to 40% by mass, more preferably 5% by mass to 30% by mass, and even more preferably 5% by mass to 20% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition.

[0087] (Solid Lubricant (C)) The liquid crystal polymer composition of the present invention contains a solid lubricant (C).

[0088] The solid lubricant (C) is not particularly limited, but can be exemplified by polyolefin resins such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-high molecular weight polyethylene, silicone resin, graphite, molybdenum disulfide, tungsten disulfide, boron nitride, fluororesin, etc. These can be used alone or in combination of two or more.Among them, from the viewpoint of achieving a higher level of both the sliding properties and mechanical strength of the obtained liquid crystal polymer molded body, the solid lubricant (C) is preferably graphite or fluororesin, more preferably fluororesin.

[0089] Fluorine resin is -(CF ２ -CF ２)- repeating units. Fluorine resins are, for example, polymers having the repeating units of -(CF ２ -CF ２ )- repeating units, and polytetrafluoroethylene resins containing perfluoroalkyl ether groups (-C ｐ F ２ｐ -O-) (p is an integer of 1 to 4) or a polyfluoroalkyl group (H(CF ２ ) ｑ ) (q is an integer of 1 to 20) is introduced into modified polytetrafluoroethylene resins.

[0090] The fluororesin may be obtained by either a suspension polymerization method for obtaining a general molding powder or an emulsion polymerization method for obtaining a fine powder. The fluororesin may also be a fluororesin obtained by subjecting a high molecular weight polytetrafluoroethylene resin to thermal decomposition or radiation to reduce its molecular weight.

[0091] The fluororesin is preferably in the form of non-fibrous particles. The average particle size of the fluororesin is preferably 0.1 μm to 100 μm, more preferably 1 μm to 50 μm, and even more preferably 5 μm to 20 μm. By setting the average particle size of the fluororesin within the above range, the sliding properties of the resulting liquid crystal polymer molded article can be further improved. The average particle size of the fluororesin can be measured in the same manner as for the non-fibrous particles described above.

[0092] The particle shape of the fluororesin is not particularly limited. For example, non-fibrous particles such as spherical, columnar, plate-like, rod-like, cylindrical, block-like, and irregularly shaped fluororesin can be used. The particle shape of the fluororesin can be analyzed, for example, by observation with a scanning electron microscope (SEM).

[0093] Although polytetrafluoroethylene (hereinafter sometimes referred to as "PTFE") resin is classified as a thermoplastic resin, it generally cannot be injection molded due to its abnormally high melt viscosity, and a resin composition containing PTFE as the main component is manufactured into a molded body by compressing mixed particles of the resin and heating them above the melting point to fuse the particles together (compression molding). The PTFE used for compression molding is of high molecular weight, but when high molecular weight PTFE is blended with a general thermoplastic resin and melt-kneaded, the PTFE fibrillates and aggregates, causing the resin composition to lose its fluidity, making it impossible to melt-knead or injection-mold.

[0094] For this reason, the PTFE used as a solid lubricant for the thermoplastic resin for injection molding has a low molecular weight. In addition, the liquid crystal polymer (A) is generally melt-kneaded at a temperature around the melting point of PTFE, and has a low viscosity when melted, so if the molecular weight of the PTFE to be blended and melt-kneaded is too large, it may aggregate.

[0095] Since the molecular weight and melt viscosity of PTFE are correlated, the MFR value of PTFE used in fluororesin, measured under conditions of 372 ° C and a load of 5 kg, is preferably 5 g / 10 min or more, more preferably 10 g / 10 min or more, and even more preferably greater than 35 g / 10 min. The upper limit of the MFR value of PTFE can be, for example, 200 g / 10 min. The MFR value of PTFE can be measured in accordance with JIS K7210.

[0096] PTFE is sometimes baked to suppress fibrillation and aggregation. Although it varies depending on the molecular weight, the melting point of the baked body is 320°C to 330°C, and the melting point of the unbaked body is 330°C to 350°C, so the degree of baking can be estimated by looking at the melting point. For fluororesins, from the viewpoint of further suppressing aggregation during molding, the melting point is preferably less than 330°C, with the lower limit being preferably 320°C. The melting point of PTFE can be measured in accordance with JIS-K7121.

[0097] The content of the solid lubricant (C) in the liquid crystal polymer composition of the present invention is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, even more preferably 5% by mass to 18% by mass, and particularly preferably 5% by mass to 15% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition. By setting the content of the solid lubricant (C) in the range of 0.1% by mass to 30% by mass, the sliding properties of the obtained liquid crystal polymer molded article can be further improved.

[0098] (Barium Sulfate (D)) The liquid crystal polymer composition of the present invention may contain barium sulfate (D) as needed.

[0099] Examples of barium sulfate (D) include elutriated barium sulfate (baryte powder) obtained by crushing a mineral called barite, washing it to remove iron, and elutriating it, and artificially synthesized precipitated barium sulfate. With precipitated barium sulfate, the particle size can be controlled by the synthesis conditions, and fine barium sulfate with a low content of the desired coarse particles can be produced. As barium sulfate (D), it is preferable to use precipitated barium sulfate from the viewpoint of further reducing impurities and making the particle size distribution more uniform.

[0100] The barium sulfate (D) is preferably non-fibrous particles, and its average particle size is preferably 0.1 μm to 50 μm, more preferably 0.1 μm to 30 μm, even more preferably 0.1 μm to 5 μm, and even more preferably 0.5 μm to 1.5 μm. By setting the average particle size of the barium sulfate (D) within the above range, the sliding properties of the obtained liquid crystal polymer molded article can be further improved. The average particle size of the barium sulfate (D) can be measured in the same manner as for the non-fibrous particles described above.

[0101] The particle shape of barium sulfate (D) is not particularly limited. As barium sulfate (D), for example, non-fibrous particles such as spherical, columnar, plate-like, rod-like, cylindrical, block-like, and irregularly shaped particles can be used. The particle shape of barium sulfate (D) is preferably spherical or irregular. The particle shape of barium sulfate (D) can be analyzed, for example, by observation with a scanning electron microscope (SEM).

[0102] Barium sulfate (D) may be surface-treated, and examples of the treating agent include coating agents, dispersants, modifiers, etc. Specific examples of the treating agent include fatty acids, waxes, nonionic surfactants, epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, phosphorus compounds, aluminum salts such as alumina, silicates such as silicon dioxide, and titanium salts such as titanium dioxide. These may be used alone or in combination.

[0103] The content of barium sulfate (D) in the liquid crystal polymer composition of the present invention is preferably 1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, and even more preferably 5% by mass to 15% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition. When the content of barium sulfate (D) is within the above range, the sliding properties of the obtained liquid crystal polymer molded article can be further improved.

[0104] (Particulate Carbon Material (E)) The liquid crystal polymer composition of the present invention may contain particulate carbon material (E) as needed.

[0105] The particulate carbon material (E) is not particularly limited, and is used, for example, for the purpose of ensuring the light-blocking properties of liquid crystal polymer molded bodies such as camera module components, and generally available materials used for resin coloring can be suitably used.

[0106] Examples of the particulate carbon material (E) that can be used include graphite; carbon black such as acetylene black, furnace black, lamp black, thermal black, channel black, roll black, and disc black; carbon nanotubes; and carbon fibrils. From the viewpoint of further improving the light-shielding properties of the resulting liquid crystal polymer molded article, the particulate carbon material (E) is preferably carbon black. The particulate carbon material (E) may be used alone or in combination of two or more types.

[0107] In the present invention, the primary particle diameter of the particulate carbon material (E) is preferably 10 nm or more, more preferably 15 nm or more, and even more preferably 20 nm or more, and is preferably 100 nm or less, more preferably 75 nm or less, and even more preferably 40 nm or less.

[0108] When the primary particle size of the particulate carbonaceous material (E) is within the above range, the particulate carbonaceous material (E) can be more easily dispersed in the liquid crystal polymer composition, and the surface resistivity of the resulting liquid crystal polymer molded article can be sufficiently reduced, thereby further suppressing an increase in the amount of charge in the liquid crystal polymer molded article.

[0109] In the present invention, the primary particle size of the particulate carbon material (E) can be an arithmetic mean particle size (number average), which is the average value of primary particle sizes measured by a transmission electron microscope.

[0110] In the present invention, the DBP oil absorption of the particulate carbon material (E) is preferably 30 cm ３ / 100g or more, more preferably 100cm ３ / 100g or more, preferably 300cm ３ / 100g or less, more preferably 200cm ３ / 100g or less.

[0111] When the DBP oil absorption of the particulate carbonaceous material (E) is equal to or greater than the lower limit, the surface resistivity of the resulting liquid crystal polymer molded article can be further reduced, and an increase in the amount of charge in the liquid crystal polymer molded article can be further suppressed. Also, when the DBP oil absorption of the particulate carbonaceous material (E) is equal to or less than the upper limit, the viscosity of the liquid crystal polymer composition can be prevented from becoming too high when melt-kneading the composition, making it easier to produce the liquid crystal polymer composition of the present invention.

[0112] In the present invention, the DBP oil absorption can be a value measured in accordance with JIS K 6221 using a dibutyl phthalate absorbed meter.

[0113] In the present invention, the BET specific surface area of ​​the particulate carbon material (E) is preferably 10 m ２ / g or more, more preferably 30m ２ / g or more, more preferably 100m ２ / g or more, preferably 300m ２ / 100g or less, more preferably 250m ２ / g or less, more preferably 200m ２ / 100g or less.

[0114] When the BET specific surface area of ​​the particulate carbon material (E) is equal to or greater than the lower limit, the surface resistance of the resulting liquid crystal polymer molded article can be further reduced, and an increase in the amount of charge in the liquid crystal polymer molded article can be further suppressed. Furthermore, when the BET specific surface area of ​​the particulate carbon material (E) is equal to or less than the upper limit, the viscosity of the liquid crystal polymer composition can be prevented from becoming too high during melt-kneading, making it easier to produce the liquid crystal polymer composition of the present invention.

[0115] In the present invention, the BET specific surface area is determined by measuring the amount of nitrogen gas adsorbed at liquid nitrogen temperature using a BET specific surface area measuring device, such as an AccuSorb 2100E manufactured by Micromeritics.

[0116] The content of the particulate carbon material (E) in the liquid crystal polymer composition of the present invention is preferably within a range of 0.1% by mass to 5.0% by mass, more preferably within a range of 0.5% by mass to 4.5% by mass, and even more preferably within a range of 1.0% by mass to 3.0% by mass, based on 100% by mass of the total amount of the liquid crystal polymer composition.

[0117] When the content of the particulate carbon material (E) is within the above range, the dispersibility of the particulate carbon material (E) in the liquid crystal polymer composition can be further improved, and the heat resistance and light-shielding properties of the obtained liquid crystal polymer molded body can be increased, while the mechanical strength, particularly the impact resistance, can be further improved.

[0118] (Other Additives) The liquid crystal polymer composition of the present invention may contain other additives within the range that does not impair its preferable physical properties.

[0119] Other additives include, for example, inorganic fillers such as calcium carbonate, mica, sericite, illite, kaolinite, montmorillonite, boehmite, smectite, vermiculite, palygorskite, pyrophyllite, hylosite, diatomaceous earth, and titanium dioxide (excluding the first inorganic filler (B1), the second inorganic filler (B2), and barium sulfate (D)); MgAl ２ O ４ , ZnAl ２ O ４ , FeAl ２ O ４ , CuFe ２ O ４ , CuCr ２ O ４ , MnFe ２ O ４ , NiFe ２ O ４ , TiFe ２ O ４ , FeCr ２ O ４ , MgCr ２ O ４conductive fillers other than particulate carbon materials (E), such as metal non-fibrous particles (e.g., aluminum flakes), metal fibrous particles, metal oxide non-fibrous particles, carbon fibrous particles, ionic liquids, surfactants, etc.; antistatic agents such as anionic antistatic agents, cationic antistatic agents, non-ionic antistatic agents, etc.; antioxidants or heat stabilizers such as hindered phenols, hydroquinones, phosphites, thioethers, and substituted derivatives thereof; ultraviolet absorbers such as resorcinols, salicylates, benzotriazoles, benzophenones, triazines, etc.; light stabilizers such as hindered phenols, hindered amines, etc.; weathering agents; light resistance agents; higher fatty acids, higher fatty acid esters, etc. Examples of suitable additives include mold release agents such as esters, higher fatty acid amides, higher fatty acid metal salts (here, higher fatty acids refer to those having 10 to 25 carbon atoms), fatty acids, and fatty acid metal salts; lubricants; flow improvers; plasticizers such as polyester-based plasticizers, glycerin-based plasticizers, polycarboxylic acid ester-based plasticizers, phosphate ester-based plasticizers, polyalkylene glycol-based plasticizers, and epoxy-based plasticizers; impact resistance modifiers; flame retardants such as phosphazene-based compounds, phosphate esters, condensed phosphate esters, inorganic phosphorus-based, halogen-based, and silicone-based flame retardants, metal oxide-based flame retardants, metal hydroxide-based flame retardants, organic metal salt-based flame retardants, nitrogen-based flame retardants, and boron compound-based flame retardants; dripping inhibitors; nucleating agents; dispersants; vibration dampers; neutralizing agents; and antiblocking agents. These may be used alone or in combination.

[0120] When the liquid crystal polymer composition of the present invention contains other additives, the content thereof is not particularly limited as long as it does not impair the preferable physical properties of the liquid crystal polymer composition of the present invention. The content of other additives is preferably 10% by mass or less, more preferably 5% by mass or less, based on 100% by mass of the total amount of the liquid crystal polymer composition.

[0121] <Method for producing liquid crystal polymer composition> The liquid crystal polymer composition of the present invention can be produced by heating and mixing (particularly, melt-kneading) a mixture obtained by blending a liquid crystal polymer (A), a first inorganic filler (B1), a second inorganic filler (B2), and a solid lubricant (C), and, if necessary, barium sulfate (D), a particulate carbon material (E), and other additives.

[0122] For melt-kneading, a known melt-kneading device such as a twin-screw extruder can be used. Specifically, the composition can be produced by (1) a method of premixing the components in a mixer (such as a tumbler or a Henschel mixer), melt-kneading the components in a melt-kneading device, and pelletizing the components with a pelletizing means (such as a pelletizer); (2) a method of preparing a masterbatch of desired components, mixing other components as necessary, and melt-kneading the masterbatch in a melt-kneading device to form pellets; or (3) a method of feeding the components to a melt-kneading device and pelletizing the masterbatch.

[0123] The processing temperature in the melt-kneading is not particularly limited as long as the liquid-crystalline polymer (A) can be melted. Usually, the cylinder temperature of the melt-kneading device used for melt-kneading is adjusted to this range. Thus, the liquid-crystalline polymer composition of the present invention exhibiting the desired effects is produced.

[0124] <Method for producing liquid crystal polymer molded article and its use> The liquid crystal polymer composition of the present invention can be molded into a liquid crystal polymer molded article by a known resin molding method such as injection molding, insert molding, compression molding, blow molding, or inflation molding, depending on the type, use, and shape of the desired liquid crystal polymer molded article. The molding method is preferably injection molding or insert molding. A molding method combining the above molding methods can also be used. The liquid crystal polymer molded article obtained by molding the liquid crystal polymer composition of the present invention can maintain a low coefficient of friction in sliding against a metal material both at the beginning of sliding and after repeated sliding.

[0125] The liquid crystal polymer molded article produced using the liquid crystal polymer composition of the present invention is suitable for use as a component in the manufacture of electronic components for precision instruments. Parts containing the liquid crystal polymer molded article are suitable for use in the manufacture of electronic components for sliding members that slide against other members, such as components selected from the group consisting of connectors, antennas, switches, relays, and camera modules. Among these, the liquid crystal polymer molded article of the present invention is particularly suitable for the manufacture of optical electronic components (camera module components) that constitute camera modules, since it is expected to prevent deterioration of optical properties due to fibrillation of the liquid crystal polymer molded article surface. Examples of optical electronic components that constitute camera modules include lens barrels (the parts on which the lens is mounted), spacers, mount holders (the parts where the barrel is attached and fixed to the substrate), bases, lens barrels, CMOS (image sensor) frames, shutters, shutter plates, shutter bobbins, aperture rings, and stoppers (the parts that hold the lens).

[0126] The liquid crystal polymer molded article of the present invention can be particularly suitably used in camera modules having actuator mechanisms such as an autofocus (AF) mechanism or an optical image stabilization (OIS) mechanism. The liquid crystal polymer molded article of the present invention can also be suitably used in electric and electronic devices having a camera function. The liquid crystal polymer molded article of the present invention can also be suitably used in smartphones or tablet terminals equipped with a camera function.

[0127] The present invention will be specifically explained below based on examples and comparative examples, but the present invention is not limited thereto. The raw materials used in the examples and comparative examples are as follows.

[0128] <Raw Materials> (Liquid Crystal Polymer (A)) Liquid Crystal Polymer: Melt Viscosity 2.4 x 10 ４ mPa·s, melting point 280°C, manufactured by Ueno Pharmaceutical Co., Ltd., product name "UENO LCP A-5000"

[0129] (Inorganic filler) Potassium titanate fiber: fibrous inorganic filler, average fiber length 15 μm, average fiber diameter 0.5 μm, manufactured by Otsuka Chemical Co., Ltd., trade name "Tismo N" Talc: plate-shaped inorganic filler, average particle diameter (D ５０ ) 13 μm, manufactured by Fuji Talc Industries Co., Ltd., product name "ML112"

[0130] (First inorganic filler (B1)) Potassium titanate fiber A: Potassium titanate fiber was charged into a Henschel mixer, and the potassium titanate fiber was surface-treated by a dry method so that 1.0 mass% of the entire potassium titanate fiber was treated with 3-glycidyloxypropyltrimethoxysilane (γ-glycidoxypropyltrimethoxysilane) (surface free energy: 55 mN / m). Thus, potassium titanate fiber A was obtained.

[0131] Talc A: Talc was charged into a Henschel mixer and subjected to a surface treatment using a dry method with 3-aminopropyltrimethoxysilane (surface free energy: 68 mN / m) in an amount of 1.0 mass % based on the total mass of the talc. Talc A was thus obtained.

[0132] (Second inorganic filler (B2)) Potassium titanate fiber B: Potassium titanate fiber was charged into a Henschel mixer, and the potassium titanate fiber was surface-treated by a dry method so that 1.0 mass% of the potassium titanate fiber was treated with decyltrimethoxysilane (surface free energy: 28 mN / m). Thus, potassium titanate fiber B was obtained.

[0133] Talc B: Talc was charged into a Henschel mixer and subjected to a surface treatment using a dry method with hexadecyltrimethoxysilane (surface free energy: 20 mN / m) in an amount of 1.0 mass % based on the total mass of the talc. Thus, Talc B was obtained.

[0134] (Other inorganic fillers) Untreated potassium titanate fibers: Potassium titanate fibers were used as they were without any surface treatment.

[0135] Potassium titanate fiber C: Potassium titanate fiber was charged into a Henschel mixer, and the potassium titanate fiber was surface-treated by a dry method with 3-glycidyloxypropyltrimethoxysilane (γ-glycidoxypropyltrimethoxysilane) and decyltrimethoxysilane in amounts of 0.5% by mass each based on the potassium titanate fiber. Potassium titanate fiber C was thus obtained.

[0136] (Solid Lubricant (C)) Polytetrafluoroethylene (PTFE) resin: average particle size 8 μm, MFR value 50 g / 10 min or more, melting point 324° C., manufactured by 3M, product name “TF-9205”

[0137] (Barium sulfate (D)) Barium sulfate (BaSO ４ ): Average particle size 1 μm, manufactured by Sakai Chemical Industry Co., Ltd., product name "Precipitated Barium Sulfate 300"

[0138] (Particulate carbon material (E)) Carbon black (CB): primary particle diameter 22 nm, BET specific surface area 124 m ２ / g, DBP oil absorption 116cm ３ / 100g, Mitsubishi Chemical Corporation, product name "#750B"

[0139] <Method for Evaluating Raw Materials> The melt viscosity of the liquid crystal polymer (A) was measured at 300°C and a shear rate of 1.0 × 10 using a melt viscosity measuring device (manufactured by Toyo Seiki Seisakusho, product name "Capirograph 1D"). ３ sec －１ The measurement was carried out using a capillary rheometer of 1.0 mmφ×10 mm under the conditions of

[0140] The melting point of the liquid crystal polymer (A) was measured in accordance with JIS-K7121.

[0141] The MFR value of PTFE was measured in accordance with JIS K7210 under conditions of 372°C, 5 minute retention, and a load of 5 kg.

[0142] The melting point of PTFE was measured using a differential scanning calorimeter (manufactured by Hitachi High-Tech Science Corporation, product name "DSC7000X") by placing 10 mg of a sample in a measurement aluminum cell, raising the temperature from room temperature to 50°C at a heating rate of 10°C / min under a nitrogen gas flow of 100 ml / min, holding at 50°C for 5 minutes, and then raising the temperature to 400°C at a heating rate of 10°C / min.

[0143] The average fiber length and average fiber diameter of the fibrous inorganic filler were determined from the average values ​​of 300 randomly selected fibers measured by observation with a scanning electron microscope (SEM).

[0144] The average particle size of each sample was measured using a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, trade name "SALD-2100").

[0145] <Production of Liquid Crystal Polymer Compositions and Liquid Crystal Polymer Molded Articles> <Examples 1 to 5 and Comparative Examples 1 to 7> Pellets were produced by melt-kneading the liquid crystal polymer compositions using a twin-screw extruder at the blending ratios shown in Tables 1 and 2. The cylinder temperature of the twin-screw extruder was 300°C.

[0146] <Evaluation> (Friction Coefficient) The obtained pellets were molded into flat plates (length 90 mm, width 50 mm, thickness 3 mm) using an injection molding machine to obtain evaluation samples (liquid crystal polymer molded articles). The cylinder temperature of the injection molding machine was 300°C, and the mold temperature was 120°C.

[0147] For each evaluation sample, a static friction tester (manufactured by Kyowa Interface Science Co., Ltd., product number "TRIBOSTAR TS 501") was used, and a sliding test with hard metal was performed under the conditions of a load of 50 g, a speed of 1 mm / sec, a travel distance of 10 mm, a stainless steel ball (SUS304, φ3 mm), and 2000 sliding cycles, and the static friction coefficient (μs) and dynamic friction coefficient (μk) were measured. Thus, the sliding test with hard metal was carried out in a sliding configuration between a flat plate (length 90 mm, width 50 mm, thickness 3 mm) and a stainless steel ball (SUS304, φ3 mm), and the average friction coefficient was measured at the initial sliding time (1 to 500 sliding cycles), 600 to 1000 sliding cycles, 1100 to 1500 sliding cycles, and 1600 to 2000 sliding cycles. The results are shown in Tables 1 and 2.

[0148]

[0149]

[0150] As is clear from Tables 1 and 2, by using a liquid crystal polymer composition containing both a first inorganic filler (B1) having a treatment layer made of a hydrophilic surface treatment agent in addition to the liquid crystal polymer (A) and the solid lubricant (C) and a second inorganic filler (B2) having a treatment layer made of a hydrophobic surface treatment agent, in Examples 1 to 5, in the sliding between the liquid crystal polymer molded body and the metal material, the friction coefficient (static friction coefficient and / or kinetic friction coefficient) at the beginning of the sliding is kept low, and the friction coefficient (static friction coefficient and / or kinetic friction coefficient) is gradually reduced even after repeated sliding.

[0151] On the other hand, in Comparative Examples 3 and 5, in which only the first inorganic filler (B1) having a treatment layer formed by a hydrophilic surface treatment agent is used as the inorganic filler, the friction coefficient (static friction coefficient and / or dynamic friction coefficient) at the beginning of sliding cannot be sufficiently reduced, and in Comparative Examples 4 and 6, in which only the second inorganic filler (B2) having a treatment layer formed by a hydrophobic surface treatment agent is used, the friction coefficient (static friction coefficient and / or dynamic friction coefficient) after repeated use is not sufficiently reduced. Also, in Comparative Example 7, in which an inorganic filler having a treatment layer formed by both a hydrophilic surface treatment agent and a hydrophobic surface treatment agent is used, it can be seen that the friction coefficient (static friction coefficient and / or dynamic friction coefficient) after repeated use is not sufficiently reduced.

[0152] Thus, in the present invention, by using a liquid crystal polymer composition containing both a specific first inorganic filler (B1) and a specific second inorganic filler (B2) in addition to the liquid crystal polymer (A) and the solid lubricant (C), it is found that the friction coefficient is kept low in sliding against a metal material both at the beginning of sliding and after repeated sliding.

[0153] <Evaluation> (Measurement of tensile adhesive strength) The obtained pellets were molded into a flat plate (length 126 mm, width 13 mm, thickness 1.6 mm) using an injection molding machine to obtain an evaluation sample (liquid crystal polymer molded article). In Example 5, the cylinder temperature of the injection molding machine was 300°C, and the mold temperature was 120°C.

[0154] The above-mentioned flat plate test specimens (126 mm long, 13 mm wide, 1.6 mm thick) were dried in a forced convection oven at 120°C for 60 minutes. After drying, the test specimen area of ​​the flat plate was wiped with solvent and thoroughly degreased. An adhesive (low-elasticity, fast-curing epoxy adhesive, product number "AE-740", manufactured by Ajinomoto Fine-Techno Co., Ltd.) was applied to the 15 mm portion of the test specimen (mold fixing surface) from the end opposite the gate. The mold fixing surfaces were bonded together with an overlap of 15 mm / min, and the specimens were secured with clips. The specimens were then cured for 60 minutes in an oven preheated to 80°C. After curing, any adhesive that protruded significantly beyond the bonding surface was removed with a cutter or other tool. After preparation, a tensile test was performed on a Shimadzu Autograph, product number "AG-I", at a speed of 10 mm / min. The resulting maximum stress (MPa) was recorded as the adhesive strength. The test was carried out five times, and the average value was taken as the adhesive strength (tensile adhesive strength), and the results are shown in Table 3.

[0155] (Weld Strength) The obtained pellets were molded into a flat plate (length 9 mm, width 9 mm, thickness 1 mm) using an injection molding machine to obtain an evaluation sample (liquid crystal polymer molded article). In Example 5, the cylinder temperature of the injection molding machine was 300°C, and the mold temperature was 120°C.

[0156] A hole with an inner diameter of 5 mm was drilled in the center of the above flat plate (length 9 mm, width 9 mm, thickness 1 mm) to prepare a test specimen. A digital force gauge (ZTA-500N, manufactured by Imada Co., Ltd.) was used to apply force to the weld at a push-pull gauge speed of 10 mm / min. The stress applied to the weld of the test specimen when the weld broke was taken as the weld strength (N). The test was performed 10 times, and the average value was taken as the weld strength (N), and the results are shown in Table 3.

[0157]

[0158] It was confirmed that the liquid crystal polymer molded article of Example 5, which used a liquid crystal polymer (A) having a melting point of 310° C. or less, also had excellent tensile adhesive strength (adhesive strength) and weld strength. Thus, when a liquid crystal polymer (A) having a melting point of 310° C. or less is used, the liquid crystal polymer molded article can also be expected to improve the adhesion between parts used in precision instruments and electronic components.

[0159] As described above, the liquid crystal polymer composition and liquid crystal polymer molded article of the present invention can be suitably used, for example, in optical electronic components constituting camera modules, and can be particularly suitably used in optical electronic components such as camera modules having actuator mechanisms such as autofocus (AF) mechanisms and optical image stabilization (OIS) mechanisms.

Claims

1. A liquid crystal polymer composition comprising a liquid crystal polymer (A), a first inorganic filler (B1), a second inorganic filler (B2), and a solid lubricant (C), wherein a treatment layer composed of a hydrophilic surface treatment agent is provided on the surface of the first inorganic filler (B1), and a treatment layer composed of a hydrophobic surface treatment agent is provided on the surface of the second inorganic filler (B2).

2. The liquid crystal polymer composition according to claim 1, wherein the surface free energy of the hydrophilic surface treatment agent is greater than 50 mN / m, and the surface free energy of the hydrophobic surface treatment agent is less than 50 mN / m.

3. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the melting point of the liquid crystal polymer (A) is 150°C to 310°C.

4. The liquid crystal polymer composition according to claim 1 or claim 2, characterized in that the liquid crystal polymer composition further contains barium sulfate (D).

5. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the liquid crystal polymer (A) is at least one of a liquid crystal polyester and a liquid crystal polyester amide.

6. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the total content of the first inorganic filler (B1) and the second inorganic filler (B2) is 5% by mass to 50% by mass in 100% by mass of the total amount of the components contained in the liquid crystal polymer composition.

7. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the first inorganic filler (B1) is fibrous particles or non-fibrous particles.

8. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the second inorganic filler (B2) is fibrous particles or non-fibrous particles.

9. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the mass ratio of the first inorganic filler (B1) to the second inorganic filler (B2) is 1:4 to 4:

1.

10. The liquid crystal polymer composition according to claim 1 or claim 2, wherein the content of the solid lubricant (C) is 1% by mass to 30% by mass in 100% by mass of the total amount of the components contained in the liquid crystal polymer composition.

11. The liquid crystal polymer composition according to claim 1 or claim 2, which is used in a camera module.

12. A liquid crystal polymer molded article, which is a molded article of the liquid crystal polymer composition according to claim 1 or claim 2.

13. The liquid crystal polymer molded article according to claim 12, which is a sliding member.

14. A camera module comprising the liquid crystal polymer molded body according to claim 12.

15. An electric and electronic device comprising the liquid crystal polymer molded body according to claim 12 and having a camera function.

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