Liquid crystal polyesters (LCPs) and thermoplastic compositions having low dielectric constant (Dk) and dissipation factor (Df)

Abstract

The present invention relates to a liquid crystal polyester (LCP) and a thermoplastic composition comprising such an LPC, which exhibits a low dielectric constant and dissipation coefficient and is suitable for mobile electronic device components, such as films or structural components.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application US 63 / 120436, filed December 2, 2020, and European Patent Application EP 21157098.1, filed February 15, 2021, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This disclosure relates to liquid crystal polyester (LCP) and thermoplastic compositions containing such LCP, which exhibit low dielectric constant and dissipation coefficient and are suitable for mobile electronic device components, such as films or structural components. Background Technology

[0004] Polymer compositions are widely used in the manufacture of mobile electronic device components due to their reduced weight and high mechanical properties. There is currently a high market demand for polymer compositions that can be used to manufacture mobile electronic device components with improved dielectric properties (i.e., low dielectric constant and dissipation coefficient).

[0005] In mobile electronic devices, the materials forming various components and housings can significantly reduce the transmission and reception of radio signals (e.g., frequencies of 1 MHz, 2.4 GHz, 5.0 GHz, 20.0 GHz) by the mobile electronic device via one or more antennas. The dielectric properties of materials to be used in mobile electronic devices can be determined by measuring the dielectric constant, as the dielectric constant represents the material's ability to interact with electromagnetic radiation and interfere with electromagnetic signals (e.g., radio signals) passing through the material. Therefore, the lower the dielectric constant of a material at a given frequency, the less interference the material will cause to electromagnetic signals at that frequency.

[0006] The applicant has discovered a new class of liquid crystal polyesters (LCPs) with improved dielectric properties, which makes them notably well-suited as materials for components in mobile electronic devices.

[0007] These LCPs are derived from specific combinations of components / monomers, including aromatic monomers and cyclohexanedicarboxylic acid monomers.

[0008] US 2020 / 017769 (Kuraray Co.) relates to a thermoplastic LCP capable of reducing dielectric dissipation in high-frequency bands and exhibiting a controlled melting point elevation. However, the LCP described in this document does not contain any cyclohexanedicarboxylic acid monomers, such as CHDA.

[0009] US 6,093,787 (Eastman Chemical Company) relates to an LCP containing a cyclohexanedicarboxylic acid (CHDA) moiety, and to a molded composition comprising such an LCP and glass fiber.

[0010] US Patent 2020 / 0102420 (SK Chemicals) discloses liquid crystal polymers (LCPs) comprising alicyclic dicarboxylic acids or derivatives thereof. Introducing alicyclic dicarboxylic acids or derivatives thereof into liquid crystal polymers improves their insulating properties. Alicyclic dicarboxylic acids or derivatives thereof include cycloalkane dicarboxylic acids or ester compounds having 5 to 20 carbon atoms. Preferably, 1,4-cyclohexanedicarboxylic acid (CHDA) can be used. The LCPs described in these documents have a large number of repeating units derived from hydroquinone and 4-hydroxybenzoic acid. Compared to the compositions of the present invention, they do not possess the desired dielectric properties.

[0011] US 4,355,133 (Celanese Corp) and US 4,318,842 (Celanese Corp) both describe melt-processable polyesters capable of forming an anisotropic molten phase at temperatures below approximately 350°C, the polyester being essentially composed of the following repeating units:

[0012]

[0013] The polymer described in US 4,318,842 contains 10 to 40 mol.% of unit III, preferably 15 to 25 mol.%, and most preferably 20 mol.%. All examples in this document describe LCP polymers having between 15 and 30 mol.%. The polymer described in US 4,355,133 contains 10 to 45 mol.% of unit III. The only example in this document describes an LCP polymer containing 24.7 mol.% of unit III. These polymers do not have the desired dielectric properties compared to the polymers of the present invention.

[0014] US 5,747,175 (Hoechst) describes LCP blends with reproducible color properties, stable temperature for automotive finishes, and high chemical resistance. This document generally describes the use of aromatic components in the preparation of LCPs, but also mentions the possibility of using aliphatic and alicyclic components, such as cyclohexanedicarboxylic acid. The only example described in this document is the use of CHDA at a molar content of 10 mol.%.

[0015] However, none of the documents listed above describe the LCPs of the present invention or their advantageous characteristics as components of mobile electronic devices. Summary of the Invention

[0016] One aspect of this disclosure relates to liquid crystal polyesters (LCPs) comprising specific combinations of repeating units. The applicant has discovered that combining multiple repeating units in specific molar amounts results in the preparation of LCP resins with improved dielectric properties and a set of thermal transition temperatures, making these resins ideally suited for use as materials in films and articles or components for mobile electronic devices.

[0017] Other aspects of the invention relate to thermoplastic compositions (C) comprising such LCPs, methods for preparing such LCPs and compositions, and the use of such polymer products in the preparation of articles or components intended for use in mobile electronic devices or transportation vehicles (including automobiles). Detailed Implementation

[0018] This document describes liquid crystal polyesters (LCPs) with improved dielectric properties and thermoplastic compositions (C) containing such LCPs, making them notably well-suited as materials for films and articles or components in mobile electronic devices. The LCPs of this invention are also well-suited for use in transportation vehicles (e.g., automobiles, aircraft, drones).

[0019] More specifically, the LCP of the present invention is prepared by combining a specific molar amount of cyclohexanedicarboxylic acid with selected aromatic components, and this specific combination of components has been shown to bring improved dielectric properties to the LCP or compositions containing such LCP compared to, for example, LCPs containing a higher amount of cyclohexanedicarboxylic acid.

[0020] The introduction of cyclohexanedicarboxylic acid (CHDA) in a selected molar ratio has also been shown to enable control of the melting temperature (Tm) and crystallization temperature (Tc) of LCP while maintaining its liquid crystal properties, which is ideal for a variety of processing requirements.

[0021] More precisely, the LCP of the present invention comprises, based on the total number of moles in the LCP:

[0022] - Repeating units of formula (I) ranging from 40 to 98 mol.%

[0023]

[0024] - Repeating units of formula (IIa), (IIb), (IIc) and / or (IId) from 1 to 20 mol.%

[0025]

[0026] and / or

[0027]

[0028] - Repeating units of formula (IIIa) and / or (IIIb) from 1 to 12 mol.%.

[0029] and / or

[0030] The LCP described herein may be an LCP that substantially contains the repeating units described above, or an LCP that contains such repeating units and optionally contains other repeating units as described below.

[0031] In some embodiments, when the LCP of the present invention includes additional repeating units, these repeating units may be selected from the group consisting of:

[0032]

[0033] and / or

[0034]

[0035] Each of these repeating units (IV), (V) and / or (VI) may be present in the LCP in molar amounts ranging from 0.1 to 15 mol.%, for example from 0.5 to 13 mol.%, from 1 to 11 mol.%, from 2 to 9 mol.%, or from 3 to 8 mol.%, based on the total number of moles in the LCP.

[0036] In some other embodiments, when the LCP of the present invention includes additional repeating units, these additional repeating units may be selected from the group consisting of:

[0037]

[0038] and / or

[0039] Each of these repeating units (VII), (VIII), (IX), (X), (XI) and / or (XI) may be present in the LCP in molar amounts ranging from 0.1 to 15 mol.%, for example from 0.5 to 13 mol.%, from 1 to 11 mol.%, from 2 to 9 mol.%, or from 3 to 8 mol.%, based on the total number of moles in the LCP.

[0040] According to the present invention, when the LCP of the present invention contains additional repeating units, these additional repeating units may be selected from the group consisting of (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI), and (XI). The LCP may contain one, two, three, four, five, six, seven, eight, or nine of these repeating units. Each of these repeating units may be present in the LCP in a molar amount ranging from 0.1 to 15 mol.%, for example, from 0.5 to 13 mol.%, from 1 to 11 mol.%, from 2 to 9 mol.%, or from 3 to 8 mol.%.

[0041] In this application:

[0042] -Even any description relating to a specific embodiment may be applied to and interchanged with other embodiments disclosed herein;

[0043] - When an element or component is referred to as being included in and / or selected from the list of enumerated elements or components, it should be understood that in the relevant embodiments explicitly considered herein, the element or component may also be any one of these enumerated individual elements or components, or may be a group consisting of any two or more of the explicitly enumerated elements or components; any element or component listed in the list of elements or components may be omitted from this list; and

[0044] - Any enumeration of numerical ranges by endpoints in this document includes all numbers contained within the enumerated range, as well as the endpoints and equivalents of that range.

[0045] In this application, the term "comprising or comprise" includes "consisting essentially of" and "consisting of".

[0046] The singular “a” or “one” used in this article includes the plural unless otherwise expressly indicated.

[0047] Throughout this document, all temperatures are given in degrees Celsius (°C).

[0048] The LCP of the present invention comprises repeating units (I), (II), and (III). As described throughout this application, repeating unit (II) may be according to formulas (IIa), (IIb), (IIc), and / or (IId). This means that, for example, the LCP of the present invention may comprise a variety of different repeating units (II), such as (IIa) and (IId) or (IIa), (IIb), and (IIc). Preferably, the LCP of the present invention comprises repeating units (IIa) and / or (IId). This also applies to repeating unit (III), which may be according to formulas (IIIa) and / or (IIIb). Preferably, the LCP of the present invention comprises repeating unit (IIIa).

[0049] More specifically, the LCP of the present invention comprises repeating units of formula (I) with a total mole percentage of 40 to 98 mol.% in the LCP, preferably 40 to 90 mol.%, more preferably 50 to 85 mol.%, or 60 to 81 mol.%. The LCP of the present invention further comprises repeating units of formula (IIa), (IIb), (IIc), and / or (IId) with a total mole percentage of 1 to 22 mol.% in the LCP, preferably 5 to 21 mol.% or 10 to 20 mol.%. The LCP of the present invention further comprises repeating units of formula (IIIa) and / or (IIIb) from 1 to 12 mol.% of the total moles in the LCP, preferably from 2 to 12 mol.%, or from 2 to 11 mol.%, or from 3 to 11 mol.%, or from 3 to 10 mol.%, or from 4 to 9.5 mol.%, or from 4.5 to 8.5 mol.%. In these embodiments, the LCP may be prepared from the following monomers: 6-hydroxy-2-naphthoic acid (HNA) (or derivatives, such as 6-acetoxy-2-naphthoic acid (AcHNA)), biphenyl (BP) (or derivatives, such as diacetoxybiphenyl (AcBP)), hydroquinone (HQ) (or derivatives, such as diacetoxybenzene (AcHQ)), and cyclohexanedicarboxylic acid (CHDA)). CHDA monomers are typically blends of cis / trans isomers, wherein the cis / trans ratio can vary between 1:99 and 99:1, for example, between 10:90 and 90:10. For example, LCPs can be prepared from hydroxy-2-naphthoic acid (HNA) (or derivatives), biphenyl phenol (BP) (or derivatives), and / or hydroquinone (HQ) (or derivatives), and cyclohexanedicarboxylic acid (CHDA). For example, LCPs can be prepared from only these three or four monomers. Various isomers of biphenyl phenol (BP) can be used to prepare the LCPs of the present invention. Biphenyl phenol (BP) can be, for example, in the form of 4,4'-biphenyl phenol (4,4'-BP), 3,4'-biphenyl phenol (3,4'-BP), or 3,3'-biphenyl phenol (3,3'-BP). One or more of these isomers can be used. Preferably, at least 4,4'-biphenyl phenol is used to prepare the LCPs of the present invention. Various isomers of hydroquinone (HQ) can also be used in the context of this invention.

[0050] The LCP of the present invention may additionally comprise repeating units (IV), (V), and / or (VI). In these embodiments, the LCP may be prepared from monomers including 2,6-naphthalenedicarboxylic acid (NDA) (or derivatives) and biphenylic acid (BB) (or derivatives). Various isomers of biphenylic acid (BB) may be used to prepare the LCP of the present invention. Biphenylic acid (BB) may be in the form of 4,4'-biphenylic acid (4,4'-BB) and / or 3,4'-biphenylic acid (3,4'-BB).

[0051] In some embodiments, the LCP of the present invention includes:

[0052] -From 65 to 75 mol.% having repeating units of formula (I),

[0053] - Repeating units of formula (IIa), (IIb), (IIc) and / or (IId) from 13 to 18 mol.% and

[0054] - From 3 to 9 mol.% of repeating units having formula (IIIa) and / or (IIIb),

[0055] Optionally, at least one of the following repeating units:

[0056] -From 3 to 11 mol.% of repeating units of formula (IV),

[0057] - Repeating units of formula (V) from 3 to 11 mol.%, and / or

[0058] - Repeating units of formula (VI) from 3 to 11 mol.%.

[0059] In some preferred embodiments, the LCP of the present invention comprises or is substantially composed of the following:

[0060] -From 65 to 75 mol.% having repeating units of formula (I),

[0061] - Repeating units of formula (IIa), (IIb), (IIc) and / or (IId) ranging from 13 to 18 mol.%.

[0062] -From 3 to 9 mol.% of repeating units having formula (IIIa) and / or (IIIb), and

[0063] -Optionally from 3 to 11 mol.% of repeating units of formula (IV).

[0064] The LCP of the present invention may further comprise repeating units (VII), (VIII), (IX), (X), (XI), and / or (XII). In these embodiments, the LCP may be prepared from the following monomers: hydroxybenzoic acid (HBA) (or derivatives, such as acetoxybenzoic acid (AcHBA)), terephthalic acid (TPA) (or derivatives), isophthalic acid (IPA) (or derivatives), resorcinol (RS) (or derivatives), and / or catechol (CT) (or derivatives). In these embodiments, the LCP may be prepared from the following monomers: 6-hydroxy-2-naphthoic acid (HNA) (or derivatives, such as 6-acetoxy-2-naphthoic acid (AcHNA)), biphenyl (BP) (or derivatives, such as diacetoxybiphenyl (AcBP)), hydroquinone (HQ) (or derivatives, such as diacetoxybenzene (AcHQ)), cyclohexanedicarboxylic acid (CHDA), terephthalic acid (TPA) (or derivatives), and / or isophthalic acid (IPA) (or derivatives). For example, LCP can be prepared solely from HNA (or its derivatives), BP (or its derivatives), HQ (or its derivatives), CHDA (or its derivatives), and TPA (or its derivatives). LCP can also be prepared solely from HNA (or its derivatives), BP (or its derivatives), HQ (or its derivatives), CHDA (or its derivatives), and IPA (or its derivatives).

[0065] Various isomers of hydroxybenzoic acid (HBA) can be used to prepare the LCP of the present invention. Notably, HBA can be in the form of 4-hydroxybenzoic acid (4-HBA) and / or 3-hydroxybenzoic acid (3-HBA).

[0066] In some embodiments, the LCP of the present invention is such that the number of moles of repeating units is as follows:

[0067] -Equation (I)+(II)+(III)+(IV)+(V)+(VI)+(VII)+(VIII)+(IX)+(X)+(XI)+(XII)=100mol.%, wherein the number of moles of repeating units having equations (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI) and / or (XII) is ≥0mol.%.

[0068] -Equation (I)+(II)+(III)+(IV)+(V)+(VI)=100mol.%, wherein the number of moles of repeating units having equations (IV), (V) and / or (VI) is ≥0mol.%, and

[0069] - Equation (I)+(II)+(III)+(VII)+(VIII)+(IX)+(X)+(XI)+(XII)=100mol.%, wherein the number of moles of repeating units having equations (VII), (VIII), (IX), (X), (XI) and / or (XII) is ≥0mol.%.

[0070] In these embodiments, LCP can be prepared from only the following monomers: 6-hydroxy-2-naphthoic acid (HNA) (or derivatives), biphenyl (BP) (or derivatives), hydroquinone (HQ) (or derivatives), cyclohexanedicarboxylic acid (CHDA) (or derivatives), 2,6-naphthoic acid (NDA) (or derivatives), and biphenylcarboxylic acid (BB) (or derivatives).

[0071] For example, the LCP of the present invention can be such that the number of moles of repeating units is as follows:

[0072] - Equation (I) + (II) + (III) = 100 mol.%, for example, Equation (I) + (IIa) + (IIIa) = 100 mol.%.

[0073] - Equation (I) + (II) + (III) + (IV) = 100 mol.%, for example, Equation (I) + (IIa) + (IIIa) + (IV) = 100 mol.%.

[0074] -Equation (I) + (II) + (III) + (V) = 100 mol.%.

[0075] -Formula (I)+(II)+(III)+(VI)=100mol.%,

[0076] -Equation (I) + (II) + (III) + (IX) = 100 mol.%, or

[0077] -Equation (I) + (II) + (III) + (X) = 100 mol.%.

[0078] In some embodiments, LCP may be prepared solely from the following monomers: 6-hydroxy-2-naphthoic acid (HNA) (or derivatives), biphenol (BP) (or derivatives), cyclohexanedicarboxylic acid (CHDA) (preferably 1,4-CHDA), and 2,6-naphthoic acid (NDA) (or derivatives).

[0079] The LPCs of this invention are prepared from various entities, some of which are diols, dicarboxylic acids, hydroxycarboxylic acids, esters, or diesters. The term "diol" refers to an organic compound having two hydroxyl groups and preferably no other functional groups that can form ester bonds. The term "dicarboxylic acid" refers to an organic compound having two carboxyl groups and preferably no other functional groups that can form ester bonds. The term "hydroxycarboxylic acid" refers to an organic compound having one hydroxyl group and one carboxyl group and preferably no other functional groups that can form ester bonds. The terms "ester" or "diester" refer to an organic compound having one or two carboxyl groups derived from a carboxylic acid (R...). 1 CO2-, where R 1 It is an organic compound (either alkyl or substituted alkyl). In other words, the LPC of the present invention is an organic compound having [-OH], [-OCOR], etc. 1 The LCP is prepared from monomers of [-OH] and [-COOH]. In some embodiments, the LCP is prepared from a molar ratio ([-OH] + [-OCOR]) ranging from 0.8 to 1.2, preferably from 0.9 to 1.1, and even more preferably from 0.95 to 1.05. 1 [[II]+[XI]+[XII]) / [III]+[IV]+[V]+[VI]+[IX]+[X]) is prepared. As an example, according to these embodiments, the molar ratio of repeating unit ([II]+[XI]+[XII]) / repeating unit ([III]+[IV]+[V]+[VI]+[IX]+[X]) is equal to 1±0.2, preferably 1±0.1, more preferably 1±0.05, and even more preferably 1±0.01.

[0080] According to the embodiments, the LCP described herein has a melting temperature (Tm) above 260°C, for example, in the range between 260°C and 320°C, for example, between 270°C and 310°C, or between 280°C and 300°C, as determined by differential scanning calorimetry (DSC) according to ASTM D3418 (cooling, heating / cooling rate of 20°C / min).

[0081] According to the embodiments, the LCP described herein has a crystallization temperature (Tc) less than 260°C, for example, in the range between 150°C and 260°C, for example, in the range between 155°C and 250°C, or between 160°C and 246°C, or between 160°C and 240°C, as determined by differential scanning calorimetry (DSC) according to ASTM D3418 (cooling, heating / cooling rate of 20°C / min).

[0082] According to the embodiments, the LCP or thermoplastic composition (C) (for the purposes of this invention) preferably has a dielectric constant Dk of less than 3.5, preferably less than 3.4, or less than or equal to 3.3 at 5 GHz, as measured in the in-plane direction (5 GHz) on a 4 cm × 4 cm × 150 μm (thickness) film obtained from a "dry molding" compression molded film using the split cylindrical resonator method (SCR method) according to ASTM D2520.

[0083] According to the embodiments, the LCP or thermoplastic composition (C) (for the purposes of this invention) preferably has a dissipation factor Df of less than 0.0060, preferably less than 0.0058, or less than or equal to 0.0055 at 5 GHz, as measured in the in-plane direction (5 GHz) on a 4 cm × 4 cm × 150 μm (thickness) film obtained from a "dry molding" compression molded film using the split cylindrical resonator method (SCR method) according to ASTM D2520.

[0084] According to the embodiments, the LCP or thermoplastic composition (C) (for the purposes of this invention) preferably has a dielectric constant Dk of less than 3.6, preferably less than 3.5, or less than or equal to 3.4 at 20 GHz, as measured in the in-plane direction (20 GHz) on a 4 cm × 4 cm × 150 μm (thickness) film obtained from a "dry molding" compression molded film using the split cylindrical resonator method (SCR method) according to ASTM D2520.

[0085] According to embodiments, the LCP or thermoplastic composition (C) (for the purposes of this invention) preferably has a dissipation factor Df of less than 0.0030, preferably less than 0.0025, or less than or equal to 0.0020 at 20 GHz, as measured in the in-plane direction (20 GHz) on a 4 cm × 4 cm × 150 μm (thickness) film obtained from a "dry molding" compression-molded film using the split cylindrical resonator method (SCR method) according to ASTM D2520. The LCP or thermoplastic composition (C) (for the purposes of this invention) more preferably has a dissipation factor Df of from 0.0010 to 0.0020 or from 0.0011 to 0.0019 at 20 GHz.

[0086] The LCP described in this article can be prepared by any conventional method applicable to the synthesis of polyesters, or more precisely, LCPs.

[0087] The LCP described herein can be prepared, for example, by thermal polycondensation of monomers and comonomers. The LCP may contain a chain limiting agent, which is a monofunctional molecule capable of reacting with a hydroxyl or carboxylic acid moiety and is used to control the molecular weight of the LCP. For example, the chain limiting agent can be acetic acid, propionic acid, and / or benzoic acid. A catalyst may also be used. Examples of catalysts are phosphorous acid, orthophosphoric acid, metaphosphoric acid, alkali metal hypophosphites such as sodium hypophosphite, and phenylphosphine. Stabilizers, such as phosphites, may also be used.

[0088] The LCP described herein can also be advantageously prepared by a solvent-free method, i.e., a method carried out in the melt in the absence of a solvent. When the condensation is solvent-free, the reaction can be carried out in equipment made of materials inert to the monomer. In this case, the equipment is selected to provide sufficient contact with the monomer and in which the removal of volatile reaction products is feasible. Suitable equipment includes stirred reactors, extruders, and kneaders.

[0089] Thermoplastic composition (C)

[0090] The LCP described herein may be present in the thermoplastic composition (C) in an amount greater than 30 wt.%, 35 wt.%, 40 wt.%, or 45 wt.% of the total weight of the thermoplastic composition (C).

[0091] LCP may be present in the thermoplastic composition (C) in an amount of less than 99.95 wt.%, less than 99%, less than 95%, less than 90%, less than 80 wt.%, less than 70 wt.%, or less than 60 wt.% of the total weight of the thermoplastic composition (C).

[0092] LCP may be present in the thermoplastic composition (C) in an amount, for example, between 30 and 90 wt.%, or between 40 and 80 wt.%, based on the total weight of the thermoplastic composition (C).

[0093] The thermoplastic composition (C) may also contain one or more components selected from the group consisting of: fillers (including reinforcing agents), toughening agents, impact modifiers, plasticizers, colorants, pigments, antistatic agents, dyes, lubricants, heat stabilizers, light stabilizers, flame retardants, nucleating agents, and antioxidants.

[0094] A wide selection of fillers (including reinforcing agents, also referred to as reinforcing fibers or reinforcing fillers) may be added to the composition (C) according to the invention. These may be selected from fibrous reinforcing agents and particulate reinforcing agents. Fibrous reinforcing fillers are considered herein to be materials having a length, width, and thickness, wherein the average length is significantly greater than both the width and thickness. Generally, such materials have an aspect ratio (defined as the average ratio between the length and the largest of the width and thickness) of at least 5, at least 10, at least 20, or at least 50. Fillers may generally be selected from mineral fillers (such as talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate), glass fibers, carbon fibers, synthetic polymer fibers, aramid fibers, aluminum fibers, titanium fibers, magnesium fibers, boron carbide fibers, rock wool fibers, steel fibers, and wollastonite. Fillers may be, for example, low dielectric constant fiber fillers or hollow fillers. Fillers may be conductive and non-conductive thermally conductive fillers, such as boron nitride, zinc oxide, or graphene. In some embodiments, the thermoplastic composition (C) comprises boron nitride or zinc oxide. In one such embodiment, the thermoplastic composition (C) comprises boron nitride and is free of zinc oxide. In another embodiment, the thermoplastic composition (C) comprises zinc oxide and is free of boron nitride. As used herein and unless otherwise expressly stated, “free of” a component means that the concentration of that component is not greater than 1 wt.%, not greater than 0.5 wt.%, not greater than 0.1 wt.%, or not greater than 0.05 wt.% based on the total weight of the thermoplastic composition (C).

[0095] Fillers (including reinforcing agents) may be present in the thermoplastic composition (C) in an amount greater than 5 wt.%, greater than 10 wt.%, greater than 15 wt.%, or greater than 20 wt.% of the total weight of the thermoplastic composition (C). Fillers may be present in the composition (C) in an amount less than 65 wt.%, less than 60 wt.%, less than 55 wt.%, or less than 50 wt.% of the total weight of the polymer composition (C).

[0096] The filler may be present in the composition (C) in an amount, for example, between 5 and 65 wt.%, or between 10 and 55 wt.%, based on the total weight of the thermoplastic composition (C).

[0097] In some embodiments, the composition (C) of the present invention may comprise a low dielectric constant fiber filler, specifically, a low dielectric constant glass fiber filler. It is desirable that the low dielectric constant filler has a low dissipation factor Df. Notably, the low dielectric constant filler may have a Dk of less than 5.0 (about 4.5) at frequencies from 1 MHz to 1 GHz and a Df of less than about 0.002 at frequencies from 1 MHz to 1 GHz. In some instances, the low dielectric constant filler is a dielectric glass fiber having a Dk of less than 5.0 at frequencies from 1 MHz to 1 GHz and a Df of less than about 0.002 at frequencies from 1 MHz to 1 GHz.

[0098] In an exemplary aspect, composition (C) comprises glass fibers, such as low dielectric constant fiber fillers, and these fibers may be selected from E-glass, S-glass, AR-glass, T-glass, D-glass, R-glass, and combinations thereof. As an example, the glass fibers may be of the “E” glass type, which is a class of fibrous glass filaments comprising lime-aluminum-borosilicate glass.

[0099] The glass fibers, such as low-dielectric-constant glass fibers, that can be used in the composition (C) of the present invention can have various shapes. These fibers may include milled or chopped glass fibers. They may be in the form of whiskers or flakes. In other examples, they may be short glass fibers or long glass fibers. Glass fibers that may have a length of about 4 mm or longer are called long fibers, and fibers shorter than this are called short fibers. In one aspect, the diameter of these glass fibers may be 10 μm, or from 2 μm to 15 μm, or from 5 μm to 12 μm.

[0100] Glass fibers (including low dielectric constant glass fibers) can have circular, flat, or irregular cross-sections. Glass fibers with non-circular cross-sections can be used in the compositions of the present invention. Alternatively, the glass fiber can have a circular cross-section. The diameter of the glass fiber can be, for example, from about 1 to about 15 μm. More specifically, the diameter of the low dielectric constant glass fiber can be, for example, from about 4 to about 10 μm. Flat glass fibers, such as flat glass fibers (CSG 3PA-830) from Nitto Boseki Co., Ltd., can also be used.

[0101] The filler present in the composition (C) of the present invention can be surface-treated with a surface treatment agent containing a coupling agent to improve adhesion to the polymer base resin. Suitable coupling agents may include, but are not limited to, silyl coupling agents, titanate-based coupling agents, or mixtures thereof. Suitable silyl coupling agents include aminosilanes, epoxysilanes, amidesilanes, azidesilanes, and propylenesilanes. Organometallic coupling agents, such as titanium or zirconium-based organometallic compounds, may also be used.

[0102] The composition (C) of the present invention may further comprise a hollow filler. The hollow filler may be, for example, hollow glass spheres, hollow glass fibers, or hollow ceramic spheres. In a specific example, the hollow filler may be hollow glass spheres. Exemplary hollow glass spheres have a content of 0.2 g / cm³. 3 The density of a hollow glass sphere is approximately 0.46 g / cm³. For example, a suitable hollow glass sphere has a density of approximately 0.46 g / cm³. 3 The density. In a further example, a suitable hollow glass sphere has a density of approximately 0.6 g / cm³. 3 The density of the hollow glass sphere. Hollow glass spheres can have diameters ranging from 5 μm to 50 μm. For example, suitable hollow glass spheres have diameters of about 30 μm ± 2 or about 20 μm ± 2. Another suitable hollow glass sphere can have a diameter of about 10 μm ± 2.

[0103] The thermoplastic composition (C) of the present invention may also contain a toughening agent, also known as an impact modifier. The toughening agent is typically a polymer with a low glass transition temperature (Tg), where the Tg is, for example, below room temperature, below 0°C, or even below -25°C. Due to its low Tg, the toughening agent is typically an elastomer at room temperature. The toughening agent may be a functionalized polymer backbone.

[0104] Toughening agents can be, for example, siloxane toughening agents.

[0105] The polymer backbone of the toughening agent can be selected from elastomer backbones, including polyethylene and its copolymers, such as ethylene-butene; ethylene-octene; polypropylene and its copolymers; polybutene; polyisoprene; ethylene-propylene-rubber (EPR); ethylene-propylene-diene monomer rubber (EPDM); ethylene-acrylate rubber; butadiene-acrylonitrile rubber, ethylene-acrylic acid (EAA), ethylene-vinyl acetate (EVA); acrylonitrile-butadiene-styrene rubber (ABS), block copolymer styrene-ethylene-butadiene-styrene (SEBS); block copolymer styrene-butadiene-styrene (SBS); methacrylate-butadiene-styrene (MBS) type core-shell elastomers, or mixtures of one or more of the above.

[0106] When toughening agents are functionalized, the functionalization of the backbone can be achieved by copolymerization of monomers containing the functionalization, or by grafting a polymer backbone with another component.

[0107] Notable examples of functionalized toughening agents include terpolymers of ethylene, acrylate, and glycidyl methacrylate; copolymers of ethylene and butyl acrylate; copolymers of ethylene, butyl acrylate, and glycidyl methacrylate; ethylene-maleic anhydride copolymers; EPR grafted with maleic anhydride; styrene copolymers grafted with maleic anhydride; SEBS copolymers grafted with maleic anhydride; styrene-acrylonitrile copolymers grafted with maleic anhydride; and ABS copolymers grafted with maleic anhydride.

[0108] The toughening agent may be present in the composition (C) in a total amount greater than 1 wt.%, greater than 2 wt.%, or greater than 3 wt.% based on the total weight of the thermoplastic composition (C). The toughening agent may be present in the thermoplastic composition (C) in a total amount less than 30 wt.%, less than 20 wt.%, less than 15 wt.%, or less than 10 wt.% based on the total weight of the thermoplastic composition (C).

[0109] The thermoplastic composition (C) may also contain other conventional additives commonly used in the art, including plasticizers, colorants, pigments (e.g., black pigments such as carbon black and aniline black), antistatic agents, dyes, lubricants (e.g., linear low-density polyethylene, calcium stearate or magnesium stearate or sodium lignite), heat stabilizers, light stabilizers, flame retardants, nucleating agents, release agents, and antioxidants.

[0110] In various aspects, the thermoplastic composition (C) may contain a release agent. Exemplary release agents may include, for example, metal stearates, stearyl stearate, pentaerythritol tetrastearate, beeswax, lignite wax, paraffin wax, etc., or combinations containing at least one of the foregoing release agents. The release agent is typically used in an amount from about 0.1 to about 1.0 parts by weight based on 100 parts by weight of the total thermoplastic composition (C) excluding any fillers.

[0111] The thermoplastic composition (C) may also contain one or more other polymers, such as LCPs other than those of the present invention, or, for example, polyethylene glycol (PEG), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN).

[0112] Preparation of thermoplastic composition (C)

[0113] This document also describes a method for preparing the thermoplastic composition (C) as detailed above. In fact, the thermoplastic composition (C) of the present invention can be prepared according to a variety of methods. The compositions disclosed herein can be blended, compounded, or otherwise combined with the foregoing components by various methods involving close mixing / blending of the material with any additional additives desired in the formulation. Such preparation methods include, for example, melt-blending LCP with specific components (e.g., fillers, toughening agents, stabilizers, and any other optional additives).

[0114] In the context of this invention, any melt blending method can be used to mix the polymeric and non-polymeric components. For example, the polymeric and non-polymeric components can be fed into a melt mixer (such as a single-screw or twin-screw extruder, a stirrer, a single-screw or twin-screw kneader, or a Banbury mixer), and this addition step can be either adding all components at once or adding them batch by batch. When adding the polymeric and non-polymeric components batch by batch, a portion of these polymeric and / or non-polymeric components is added first, and then melt-mixed with the subsequently added remaining polymeric and non-polymeric components until a well-mixed composition is obtained. If the reinforcing agent exhibits a long physical shape (e.g., long glass fibers), stretch extrusion molding can be used to prepare the reinforced thermoplastic composition (C).

[0115] Product and end-use applications

[0116] This invention relates to articles comprising the LCP or thermoplastic composition (C) described herein.

[0117] The LCP or thermoplastic composition (C) of the present invention can be in various forms. For example, they can be in powder, fibrous, or granular form. They can also be in liquid form.

[0118] Powders, fibers, or granules of LCP can be produced using any method known to those skilled in the art, including mechanical, solution, and melt methods. Mechanical methods include grinding and milling solid LCP (e.g., cryogenic milling, air jet milling, ball milling, or similar methods). Solution methods include coagulating / precipitating soluble or semi-soluble LCP (e.g., solution coagulation or granulation). Fibers can be produced by melt spinning, solution spinning, or similar methods. Fibers can be monofilaments or bicomponent filaments, such as core-sheath and side-by-side filaments.

[0119] The LCP or thermoplastic composition (C) of the present invention can be used as a filler or additive in dispersions, solutions, films and injection-molded specimens.

[0120] For example, powders can be used as additives in dispersions (notably dispersions of polyamide / polyimide solutions, LCP solutions, or polysulfone solutions). They can also be used as matrices to coalesce into films or 3D objects. They can also be used as materials for injection molding, such as in narrow-pitch connectors, thin-walled parts, housings, microswitches, and structural materials for cameras. They can also be used as fillers / additives in resins for injection-molded parts such as structural components, antennas, and base stations.

[0121] Fibers can be used as short fibers in spunbonds, and also shredded as reinforcing agents / fillers. Possible methods for producing fibers include melt spinning, solution spinning, or similar methods. They can be monofilaments or bicomponent filaments (e.g., core-sheath, side-by-side).

[0122] The LCP or thermoplastic composition (C) of the present invention can be formed in the form of a film, such as a flexible printed circuit board (FPC).

[0123] LCP or thermoplastic compositions (C) can also be injection molded for structural components of microelectronic and smart devices, and mobile electronic devices (i.e., electronic devices designed for easy transport and use in various locations). Mobile electronic devices can include, but are not limited to, mobile phones, personal digital assistants (“PDAs”), laptops, tablets, wearable computing devices (e.g., smartwatches, smart glasses, etc.), cameras, portable audio players, portable radios, GPS receivers, and portable game consoles.

[0124] The LCP and thermoplastic composition (C) described herein achieves dielectric properties attributable to the synergistic effect between the LCP components. The LCP and thermoplastic composition (C) of the present invention also exhibits a set of advantageous thermal properties (e.g., Tm and Tc) while maintaining a liquid crystal morphology. This is particularly desirable for forming films of LCPs. More specifically, the inventors have realized that the LCPs of the present invention exhibit a set of Tc and Tm that make them very suitable for processing in film form. Notably, as described above, their Tc is preferably below 260°C and their Tm is above 260°C. The LCPs of the present invention can withstand assembly processing steps in microelectronic spaces. Various lamination / surface mount technologies (SMT) use temperatures above 260°C; therefore, LCPs having a Tm above 260°C (e.g., from about 280°C to 300°C) are obviously advantageous.

[0125] According to an embodiment, the mobile electronic device component may, for example, include a radio antenna and the composition (C). In this case, the radio antenna may be a WiFi antenna or an RFID antenna. The mobile electronic device component may also be an antenna housing.

[0126] In some embodiments, the mobile electronic device component is an antenna housing. In some such embodiments, at least a portion of the radio antenna is disposed on the thermoplastic composition (C). Additionally or alternatively, at least a portion of the radio antenna may be removable from the thermoplastic composition (C). In some embodiments, the device component may be a mounting component having mounting holes or other fastening devices, including but not limited to snap-fit ​​connectors between itself and another component of the mobile electronic device, including but not limited to circuit boards, microphones, speakers, displays, batteries, covers, housings, electrical or electronic connectors, hinges, radio antennas, switches, or switchpads. In some embodiments, the mobile electronic device may be at least a portion of an input device.

[0127] In some embodiments, mobile electronic device parts or components are used in vehicles such as automobiles (e.g., smart cars / intelligent cars with 5G capabilities), aircraft, and drones.

[0128] In another aspect, the molded articles can be used to manufacture articles, devices, or components in the field of transportation vehicles, notably the automotive field. Still in another aspect, non-limiting examples of such devices in the automotive field that can be used inside a vehicle with the disclosed blended thermoplastic composition (C) include adaptive cruise control, headlight sensors, windshield wiper sensors, and door / window switches. In another aspect, non-limiting examples of devices in the automotive field that can be used on the exterior of a vehicle with the disclosed blended thermoplastic composition (C) include pressure and flow sensors for engine management, air conditioning, collision detection, and exterior lighting.

[0129] All disclosures of patent applications and publications cited herein are incorporated herein by reference to the extent that they provide exemplary, procedural, or other detailed supplements to those cited herein. If any disclosure of a patent, patent application, or publication incorporated herein by reference conflicts with the description of this application to the extent that it may lead to ambiguity in terminology, this description shall prevail.

[0130] Example

[0131] These examples demonstrate the thermal and dielectric properties of the LCP of the present invention or a comparative LCP.

[0132] raw materials

[0133] AcHNA: 6-acetoxy-2-naphthoic acid, available from TCI (Tokyo Chemical Industry).

[0134] AcBP: 4,4'-diacetoxybiphenyl, commercially available from TCI.

[0135] CHDA: 1,4-cyclohexanedicarboxylic acid, commercially available from Sigma-Aldrich (cis / trans ratio 78.5:21.5).

[0136] NDA: 2,6-Naphthalenedicarboxylic acid, available commercially from TCI.

[0137] 4,4'-BB: 4,4'-Biphenylcarboxylic acid, available commercially from TCI.

[0138] Comparison with LCP resin 1

[0139] The reaction was carried out in a dry 100 mL round-bottom flask equipped with a top stirrer, a nitrogen inlet, and a distillation neck attached to the receiving flask. 33.68 g of AcHNA (70 mol.%), 5.40 g of CHDA (15 mol.%), and 8.47 g (15 mol.%) of AcBP were added. An anaerobic environment was subsequently created by degassing under vacuum and purging with N2 gas (3×). The initial temperature was 220 °C, or the temperature at which all monomers formed a melt, and this temperature was maintained with stirring for 0.5 h. The temperature was increased from the initial temperature at a rate of 1.0 °C / min up to 335 °C and maintained at this temperature for 1 h. A vacuum was then applied for 0.5–1 h to promote the removal of acetic acid condensate, followed by a high vacuum of 0.1–2 mmHg. The reaction was maintained under high vacuum until no significant condensate was observed leaving the reaction and the polymer sample solidified around the stirrer blades. The sample was then cooled and removed from the stirrer blades. The LCP was dried overnight at 100 °C before use.

[0140] LCP resin 2 of the present invention

[0141] This example follows the aforementioned procedure, with 33.07 g (70 mol.%) of AcHNA, 3.11 g (7 mol.%) of NDA, 2.83 g (8 mol.%) of CHDA, and 8.32 g (15 mol.%) of AcBP as monomer feed.

[0142] Comparison with LCP resin 3

[0143] This example follows the aforementioned procedure, with 29.02 g (60 mol.%) of AcHNA, 7.24 g (20 mol.%) of CHDA, and 11.36 g (20 mol.%) of AcBP as monomer feedstock.

[0144] LCP resin 4 of the present invention

[0145] This example follows the aforementioned procedure, with 32.72 g (70 mol.%) of AcHNA, 3.44 g (7 mol.%) of 4,4'BB, 2.80 g (8 mol.%) of CHDA, and 8.23 ​​g (15 mol.%) of AcBP as monomer feed.

[0146] LCP resin 5 of the present invention

[0147] This example follows the procedure described above as having LCP resin 2 of the present invention, but wherein 70 mol.% AcHNA, 15 mol.% AcBP, 10 mol.% NDA and 5 mol.% CHDA are used as monomers.

[0148] Membrane preparation

[0149] Compression molding was performed using two stainless steel plates, layered with a Kapton membrane and aluminum gaskets to control the thickness (0.004”). The sample was heated at Tm+20°C for approximately 3 minutes before placing the top plate. The sandwich structure was placed in the center of the press and closed to ensure contact with the upper and lower pressure plates. After heating at Tm+20°C for 2 minutes, four pressure-release-pressure cycles were performed (the first two cycles with a force of 2 tons and the last two cycles with a force of 4 tons) to complete the membrane compression molding procedure. The sandwich structure was immediately removed from the press and placed on a cool workbench, allowing it to recover to ambient temperature for at least 1 hour. The membrane was then removed from the sandwich structure and placed in an inert oven using N2 gas for annealing at 200°C for 18 hours.

[0150] test

[0151] Thermal transition (Tg, Tm)

[0152] The glass transition temperature and melting temperature of various LCPs were measured using differential scanning calorimetry (DSC) at a heating and cooling rate of 20 °C / min, according to ASTM D3418. Three scans were performed for each DSC test: a first heating to 340 °C, followed by a first cooling to 30 °C, and then a second heating to 350 °C. Tm was determined by the second heating, and Tc was determined by the cooling. The melting temperatures are listed in Table 1 below.

[0153] Compression molding and dielectric properties

[0154] Using a Carver 8393 laboratory press, 4”×4”×006” cubes were compression molded from dry granular polymer. The dielectric constant Dk and dissipation coefficient Df were measured on films of 4cm×4cm×150μm (thickness) obtained from the dry molding compression molding process. The in-plane dielectric constant Dk and dissipation coefficient Df were measured using the split cylindrical resonator method (SCR method) according to ASTM D2520.

[0155] result

[0156] The films made from resins 2, 4, and 5 of the present invention (having 5 to 8 mol% CHDA) have a dissipation coefficient Df of 0.0011 to 0.0019 at 20 GHz, while the films made from comparative resins 1 and 3 (having 15 and 20 mol% CHDA) have a higher dissipation coefficient Df of 0.0031 to 0.0046 at 20 GHz.

[0157]

[0158]

[0159] Table 1

Claims

1. A liquid crystal polyester (LCP), wherein the liquid crystal polyester (LCP) comprises, based on the total molar number of the liquid crystal polyester (LCP): - Repeating units of formula (I) ranging from 40 to 98 mol.% - Repeating units of formula (II) from 1 to 20 mol.% (IIc), and / or - Repeating units of formula (III) from 1 to 12 mol.% (IIIa) and / or (IIIb), It further includes: - Repeating units of formula (IV) from 0.1 to 15 mol.% , and / or - Repeating units of formula (V) from 0.1 to 15 mol.%: (V)， The number of moles in the repeating unit is as follows: - Equation (I) + (II) + (III) + (IV) = 100 mol.%, or - Formula (I)+(II)+(III)+(V) = 100 mol.%.

2. The liquid crystal polyester (LCP) as described in claim 1, further comprising: - Repeating units of formula (VI) from 0.1 to 15 mol.% 。 3. The liquid crystal polyester (LCP) as described in claim 1 or 2, further comprising: - Repeating units of formula (VII) from 0.1 to 15 mol.% - Repeating units of formula (VIII) from 0.1 to 15 mol.% - Repeating units of formula (IX) from 0.1 to 15 mol.% - Repeating units of formula (X) from 0.1 to 15 mol.% (X), and / or - Repeating units of formula (XI) from 0.1 to 15 mol.% (XI), and / or - Repeating units of formula (XII) from 0.1 to 15 mol.% 。 4. The liquid crystal polyester (LCP) as described in claim 1 or 2, comprising: - From 40 to 90 mol.% of repeating units with formula (I), - Repeating units of formula (II) from 10 to 20 mol.%, and - Repeating units of formula (III) from 2 to 12 mol.%.

5. The liquid crystal polyester (LCP) as described in claim 2, comprising: - Repeating units of formula (I) ranging from 65 to 85 mol.%. - Repeating units of formula (II) from 13 to 18 mol.%, and - Repeating units of formula (III) ranging from 3 to 11 mol.%. Optionally, at least one of the following repeating units: - Repeating units of formula (IV) from 1 to 11 mol.%. - Repeating units of formula (V) from 1 to 11 mol.%, and / or - Repeating units of formula (VI) from 1 to 11 mol.%.

6. The liquid crystal polyester (LCP) as described in claim 1, which is obtained by condensation of the following: - 6-Acetoxy-2-naphthoic acid (AcHNA) ranging from 40 to 98 mol.%. - 1 to 20 mol.% of 4,4'-biphenyl (BP), hydroquinone (HQ), 4,4'-diacetoxybiphenyl (AcBP) and / or 1,4-diacetoxybenzene (AcHQ). - Cyclohexanedicarboxylic acid (CHDA) from 1 to 12 mol.%, and - 0.1 to 15 mol.% of 2,6-naphthalenedicarboxylic acid (NDA), and / or - 4,4'-biphenylcarboxylic acid (4,4'-BB) from 0.1 to 15 mol.% 7. The liquid crystal polyester (LCP) as described in claim 6, wherein, Cyclohexanedicarboxylic acid (CHDA) is 1,4-cyclohexanedicarboxylic acid (1,4-CHDA).

8. The liquid crystal polyester (LCP) as described in claim 1 or 2, wherein it comprises [-OH], [-OCOR] 1 The condensation of monomers [-OH] and [-COOH] is obtained, wherein the molar ratio ([-OH] + [-OCOR]) is... 1 The range of [-COOH] is from 0.8 to 1.2, R 1 It is an alkyl or substituted alkyl group.

9. A thermoplastic composition (C) comprising liquid crystal polyester (LCP) as claimed in any one of claims 1-8, and optionally at least one component selected from the group consisting of: reinforcing agents, toughening agents, plasticizers, colorants, pigments, antistatic agents, dyes, lubricants, heat stabilizers, light stabilizers, flame retardants, nucleating agents, and antioxidants.

10. A mobile electronic device article or component comprising a liquid crystal polyester (LCP) as claimed in any one of claims 1-8 or a thermoplastic composition (C) as claimed in claim 9.

11. The article or component as claimed in claim 10, wherein, The liquid crystal polyester (LCP) or the thermoplastic composition (C) has the following characteristics: - A dielectric constant Dk less than 3.5 at 5 GHz, measured according to ASTM D2520 at 5 GHz, and / or - A dissipation factor Df less than 0.0060 at 5 GHz, measured according to ASTM D2520 at 5 GHz, and / or - A dielectric constant Dk less than 3.6 at 20 GHz, measured according to ASTM D2520 at 20 GHz, and / or - Dissipation factor Df less than 0.0030 at 20 GHz, measured at 20 GHz according to ASTM D2520.

12. The article or component as claimed in claim 10 or 11, wherein the article or component is in the form of a film.

13. The article or component as claimed in claim 10 or 11, wherein the article or component is a flexible printed circuit board (FPC).

14. Use of the liquid crystal polyester (LCP) as described in any one of claims 1-8 or the thermoplastic composition (C) as described in claim 9 in the manufacture of articles or components for mobile electronic devices.

15. Use of the liquid crystal polyester (LCP) as described in any one of claims 1-8 or the thermoplastic composition (C) as described in claim 9 for the preparation of devices, articles or components intended for use in transportation vehicles.

16. Use of the liquid crystal polyester (LCP) as described in any one of claims 1-8 or the thermoplastic composition (C) as described in claim 9 for the preparation of devices, articles or components intended for use in automobiles or aircraft.

17. Use of cyclohexanedicarboxylic acid (CHDA) in the preparation of liquid crystal polyester (LCP) as described in any one of claims 1-8, wherein the molar ratio of cyclohexanedicarboxylic acid (CHDA) varies between 1 and 12 mol.%.

18. The use as described in claim 17, wherein the liquid crystal polyester (LCP) comprises from 4 to 9.5 mol.% of repeating units having formula (III).

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