Liquid crystal polymer composition

Abstract

Disclosed is a polymer composition comprising a polymer matrix containing at least one thermotropic liquid crystalline polymer and at least one hollow inorganic filler having a dielectric constant of about 3.0 or less at a frequency of 100 MHz, wherein the weight ratio of the at least one thermotropic liquid crystalline polymer to the at least one hollow inorganic filler is from about 0.1 to about 10, and the polymer composition exhibits a dielectric constant of about 4 or less and a dielectric loss tangent of about 0.02 or less, determined at a frequency of 10 GHz.

Description

[Technical Field]

[0001] Cross-reference of related questions

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 898,208, having a filing date of September 10, 2019; U.S. Provisional Patent Application No. 62 / 994,317, having a filing date of March 25, 2020; U.S. Provisional Patent Application No. 63 / 038,968, having a filing date of June 15, 2020; and U.S. Provisional Patent Application No. 63 / 056,853, having a filing date of July 27, 2020, which are incorporated by reference herein in their entireties. [Background technology]

[0002]

[0002] Electrical components often contain molded parts formed from liquid crystalline thermoplastics. Recent demands on the electronics industry have necessitated miniaturization of such components to achieve desired performance and space savings. One such component is an electrical connector, which can be external (e.g., used for power or communications) or internal (e.g., computer disk drives or servers, link printed wiring boards, wires, cables, and other EEE components). To achieve desired properties, specific liquid crystalline polymers with specific monomers may be utilized, and specific additives may also be used with the liquid crystalline polymer. Despite the benefits achieved, such compositions have various drawbacks. For example, such compositions may not exhibit desired dielectric properties. In particular, such compositions may exhibit relatively high dielectric constants and dissipation factors, making them difficult to use in certain applications. Furthermore, such compositions may not exhibit the desired balance between the dielectric, thermal, and mechanical properties of the polymer composition. Summary of the Invention [Problem to be solved by the invention]

[0003]

[0003] Therefore, a need exists for polymer compositions that have a relatively low dielectric constant and a relatively low dissipation factor, yet can still maintain excellent mechanical properties and processability (eg, low viscosity). [Means for solving the problem]

[0004]

[0004] According to one embodiment of the present invention, a polymer composition is disclosed comprising a polymer matrix containing at least one thermotropic liquid crystal polymer and at least one hollow inorganic filler having a dielectric constant of about 3.0 or less at a frequency of 100 MHz, wherein the weight ratio of the at least one thermotropic liquid crystal polymer to the at least one hollow inorganic filler is from about 0.1 to about 10, and the polymer composition exhibits a dielectric constant of about 4 or less and a dielectric loss tangent of about 0.015 or less determined at a frequency of 10 GHz.

[0005] In accordance with another embodiment of the present invention, a molded part is disclosed that includes the aforementioned polymer composition.

[0006] According to another embodiment of the present invention, an electrical connector formed from the aforementioned polymer composition is disclosed.

[0006]

[0007] Other features and aspects of the present invention are described in more detail below.

[0008] A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0007] [Figure 1A]

[0009] 1 is a diagram of a thin-walled electrical connector according to an aspect of the present invention. [Figure 1B]

[0010] FIG. 1B is an enlarged view of a portion of the thin-walled connector of FIG. 1A. [Figure 2]

[0011] 10 is an exploded perspective view of another embodiment of a thin-walled connector and connector receptacle formable in accordance with the present invention; [Figure 3]

[0012] FIG. 1 is a diagram of a 5G communication system including a base station, a relay station, a user computing device, and a Wi-Fi repeater. DETAILED DESCRIPTION OF THE INVENTION

[0008]

[0013] It will be understood by those skilled in the art that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the invention.

[0014] Generally, the present invention relates to a polymer composition containing a unique combination of a thermotropic liquid crystalline polymer and a hollow inorganic filler. In particular, since the thermotropic liquid crystalline polymer and the hollow inorganic filler each have their own unique properties, by combining them within a specific ratio range, a polymer composition having beneficial properties can be provided. For example, the polymer composition has a relatively low dielectric constant (D k ) and a relatively low dielectric loss tangent (D f ), as well as exhibiting good mechanical properties and good processability.

[0009]

[0015] To provide such beneficial properties, the weight ratio of thermotropic liquid crystalline polymer to hollow inorganic filler may be about 0.1 or greater, in some embodiments about 1 or greater, in some embodiments about 1.5 or greater, in some embodiments about 0.1 to about 10, in some embodiments about 1 to about 10, in some embodiments about 2 to about 10, in some embodiments about 2 to about 6, and in some embodiments about 2 to about 5.

[0010]

[0016] As a result, the polymer composition may have a relatively low dielectric constant and loss tangent. Providing a polymer composition with such dielectric properties can help minimize signal loss and improve performance when utilized in certain applications, such as signal transmission applications, particularly those related to 5G communications.

[0011]

[0017] In this regard, the dielectric constant of the polymer composition may be about 4 or less, in some embodiments about 3.7 or less, in some embodiments about 3.5 or less, in some embodiments about 0.5 to about 3.4, or in some embodiments about 1.0 to about 3.2, as determined by split post resonance at a frequency of 10 GHz. Further, the dielectric loss tangent, which is a measure of the rate of energy loss of the polymer composition, may be about 0.02 or less, in some embodiments about 0.015 or less, in some embodiments about 0.01 or less, in some embodiments about 0.001 to about 0.01, or in some embodiments about 0.001 to about 0.006, as determined by split post resonance at a frequency of 10 GHz.

[0012]

[0018] In particular, to provide such a relatively low dielectric constant, the hollow inorganic filler may be capable of reducing the dielectric constant of the polymer matrix. For example, the use of both hollow inorganic fillers may reduce the dielectric constant of the polymer matrix by about 2% or more, in some embodiments, by about 3% or more, in some embodiments, by about 3.5% to about 50%, and in some embodiments, by about 4% to about 30%. Similarly, the use of both hollow inorganic fillers may reduce the dielectric loss tangent of the polymer matrix. For example, the use of hollow inorganic fillers may reduce the dielectric loss tangent of the polymer matrix by about 2% or more, in some embodiments, by about 3% or more, in some embodiments, by about 3.5% to about 50%, and in some embodiments, by about 4% to about 30%.

[0013]

[0019] Furthermore, it has traditionally been thought that polymer compositions exhibiting such a combination of low dielectric constant and low dielectric loss tangent do not simultaneously possess sufficiently good thermal and mechanical properties and ease of processability (i.e., low viscosity) to enable their use in certain types of applications. However, contrary to conventional thinking, it has been found that the polymer compositions possess both excellent thermal and mechanical properties and processability.

[0014]

[0020] For example, the melting temperature of the polymer composition may be, for example, about 180°C or higher, in some embodiments about 200°C, in some embodiments about 210°C to about 400°C, and in some embodiments about 220°C to about 380°C. Even at such melting temperatures, the ratio of temperature deflection under load ("DTUL"), a measure of short-term heat resistance, to melting temperature may still remain relatively high. For example, the ratio may range from about 0.5 to about 1.00, in some embodiments about 0.6 to about 0.95, and in some embodiments about 0.65 to about 0.85. A particular DTUL value may be, for example, about 200°C or higher, in some embodiments about 200°C to about 350°C, for example, from about 210°C to about 320°C, for example, from about 230°C to about 290°C.

[0015]

[0021] The polymeric compositions may also have excellent mechanical properties that may be useful in forming molded parts. For example, the polymeric compositions may exhibit a tensile strength of about 20 MPa or greater, in some embodiments about 30 MPa or greater, in some embodiments about 40 MPa to about 300 MPa, and in some embodiments about 50 MPa to about 100 MPa. The tensile properties may be determined according to ISO Test No. 527:2012 at a temperature of 23°C. Furthermore, the polymeric compositions may exhibit a flexural strength of about 20 MPa or greater, in some embodiments about 50 MPa or greater, in some embodiments about 60 MPa to about 300 MPa, and in some embodiments about 80 MPa to about 250 MPa. The flexural properties may be determined according to ISO Test No. 178:2010 at a temperature of 23°C. Furthermore, the polymeric compositions may also have high impact strength that may be useful in forming thin substrates. For example, the polymeric compositions may exhibit a flexural strength of about 3 kJ / m 2 or greater, in some embodiments, about 5 kJ / m 2 or greater, in some embodiments, about 7 kJ / m 2 or more, in some embodiments, about 8 kJ / m 2 ~about 40kJ / m 2 , and in some embodiments, about 10 kJ / m 2 ~about 25kJ / m 2 The impact strength may be determined in accordance with ISO Test No. ISO 179-1:2010 at a temperature of 23°C.

[0016]

[0022] Various embodiments of the invention will now be described in more detail. I. polymer composition A. polymer matrix

[0023] The polymer matrix contains one or more liquid crystalline polymers. Liquid crystalline polymers generally have a rod-like structure and are classified as "thermotropic" as long as they are capable of exhibiting crystalline behavior in their molten state (e.g., a thermotropic nematic state). Liquid crystalline polymers utilized in the polymer composition typically have a melting temperature of about 180°C or higher, in some embodiments about 200°C or higher, in some embodiments from about 220°C to about 350°C, and in some embodiments from about 240°C to about 300°C. Melting temperatures may be determined as known in the art using differential scanning calorimetry ("DSC"), for example, by ISO Test No. 11357-3:2011.

[0017]

[0024] Liquid crystal polymers may be formed from one or more types of repeat units, as known in the art. Liquid crystal polymers, for example, generally have the following formula (I):

[0018] [ka]

[0019] (In the formula, Ring B is a substituted or unsubstituted 6-membered aryl group (e.g., 1,4-phenylene or 1,3-phenylene), a substituted or unsubstituted 6-membered aryl group fused to a substituted or unsubstituted 5- or 6-membered aryl group (e.g., 2,6-naphthalene), or a substituted or unsubstituted 6-membered aryl group linked to a substituted or unsubstituted 5- or 6-membered aryl group (e.g., 4,4-biphenylene); Y1 and Y2 are independently O, C(O), NH, C(O)HN, or NHC(O). The aromatic ester compound contains one or more aromatic ester repeat units represented by:

[0020]

[0025] Typically, at least one of Y1 and Y2 is C(O). Examples of such aromatic ester repeat units include, for example, aromatic dicarboxylic acid repeat units (in Formula I, Y1 and Y2 are C(O)), aromatic hydroxycarboxylic acid repeat units (in Formula I, Y1 is O and Y2 is C(O)), and various combinations thereof.

[0021]

[0026] For example, aromatic dicarboxylic acid repeat units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, bis(4-carboxyphenyl)ether, bis(4-carboxyphenyl)butane, bis(4-carboxyphenyl)ethane, bis(3-carboxyphenyl)ether, bis(3-carboxyphenyl)ethane, etc., as well as alkyl-, alkoxy-, aryl-, and halogen-substituted versions thereof, and combinations thereof, may be utilized. Particularly suitable aromatic dicarboxylic acids include, for example, terephthalic acid ("TA"), isophthalic acid ("IA"), and 2,6-naphthalenedicarboxylic acid ("NDA"). When utilized, repeat units derived from aromatic dicarboxylic acids (e.g., IA, TA, and / or NDA) typically comprise from about 5 mol.% to about 60 mol.%, in some embodiments from about 10 mol.% to about 55 mol.%, and in some embodiments, from about 15 mol.% to about 50 mol.% of the polymer.

[0022]

[0027] Also useful are aromatic hydroxycarboxylic acid repeat units derived from aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 4-hydroxy-4'-biphenylcarboxylic acid, 2-hydroxy-6-naphthoic acid, 2-hydroxy-5-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, and the like, as well as alkyl-, alkoxy-, aryl-, and halogen-substituted versions thereof, and combinations thereof. Particularly suitable aromatic hydroxycarboxylic acids are 4-hydroxybenzoic acid ("HBA") and 6-hydroxy-2-naphthoic acid (HNA). When utilized, repeat units derived from hydroxycarboxylic acids (e.g., HBA and / or HNA) typically comprise from about 10 mol.% to about 85 mol.%, in some embodiments from about 20 mol.% to about 80 mol.%, and in some embodiments, from about 25 mol.% to about 75 mol.% of the polymer.

[0023]

[0028] Other repeat units can also be utilized in the polymer. For example, in certain embodiments, repeat units derived from aromatic diols such as hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl (or 4,4'-biphenol), 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, bis(4-hydroxyphenyl)ethane, and the like, as well as alkyl, alkoxy, aryl, and halogen-substituted versions thereof, and combinations thereof, may be utilized. Particularly suitable aromatic diols include, for example, hydroquinone ("HQ") and 4,4'-biphenol ("BP"). When utilized, repeat units derived from aromatic diols (e.g., HQ and / or BP) typically comprise from about 1 mol % to about 30 mol %, in some embodiments from about 2 mol % to about 25 mol %, and in some embodiments, from about 5 mol % to about 20 mol % of the polymer. Repeat units such as those derived from aromatic amides (e.g., acetaminophen (“APAP”)) and / or aromatic amines (e.g., 4-aminophenol (“AP”), 3-aminophenol, 1,4-phenylenediamine, 1,3-phenylenediamine, etc.) may also be utilized. When utilized, repeat units derived from aromatic amides (e.g., APAP) and / or aromatic amines (e.g., AP) typically comprise from about 0.1 mol.% to about 20 mol.%, in some embodiments from about 0.5 mol.% to about 15 mol.%, and in some embodiments, from about 1 mol.% to about 10 mol.% of the polymer. It should also be understood that various other monomeric repeat units may be incorporated into the polymer. For example, in certain embodiments, the polymer may contain one or more repeat units derived from non-aromatic monomers, such as aliphatic or alicyclic hydroxycarboxylic acids, dicarboxylic acids, diols, amides, amines, and the like. Of course, in other embodiments, the polymer may be “fully aromatic” in that it does not include repeat units derived from non-aromatic (e.g., aliphatic or alicyclic) monomers.

[0024]

[0029] Although not required, the liquid crystal polymer may be made from a polymer such as naphthalene-2,6-dicarboxylic acid ("NDA"), 6-hydroxy-2-naphthoic acid ("HNA"), or a combination thereof. Naphthalene Hydroxycarboxylic acids and Naphthalene As long as it contains a relatively high content of repeating units derived from dicarboxylic acid, Naphthalene " may be a polymer. Naphthalene The total amount of repeat units derived from hydroxycarboxylic acids and / or dicarboxylic acids (e.g., NDA, HNA, or a combination of HNA and NDA) may be about 10 mol.% or more of the polymer, in some embodiments, about 12 mol.% or more, in some embodiments, about 15 mol.% or more, in some embodiments, about 18 mol.% or more, in some embodiments, about 30 mol.% or more, in some embodiments, about 40 mol.% or more, in some embodiments, about 45 mol.% or more, in some embodiments, about 50 mol.% or more, in some embodiments, about 55 mol.% or more, and in some embodiments, about 60 mol.% to about 95 mol.%. Without being limited by theory, such "high Naphthalene It is believed that the polymer can reduce the tendency of the polymer composition to absorb water, thereby promoting the stabilization of the dielectric constant and the dielectric loss tangent in the high frequency range. Naphthalene The polymer typically has a water absorption of about 0.015% or less, in some embodiments about 0.01% or less, and in some embodiments, about 0.0001% to about 0.008%, after 24 hours of immersion in water according to ISO 62-1:2008. NaphthaleneThe polymer may also have a moisture absorption of about 0.01% or less, in some embodiments about 0.008% or less, and in some embodiments about 0.0001% to about 0.006%, after exposure to a humid atmosphere (50% relative humidity) according to ISO 62-4:2008 at a temperature of 23° C. In one embodiment, for example, repeat units derived from HNA and / or NDA may comprise 10 mol.% or more, in some embodiments about 12 mol.% or more, in some embodiments about 15 mol.% or more, and in some embodiments about 18 mol.% to about 95 mol.% of the polymer. In such embodiments, the liquid crystal polymer may further contain various other monomers, such as aromatic hydroxycarboxylic acids (e.g., HBA) in an amount of from about 20 mol.% to about 60 mol.%, and in some embodiments, from about 30 mol.% to about 50 mol.%, aromatic dicarboxylic acids (e.g., IA and / or TA) in an amount of from about 2 mol.% to about 30 mol.%, and in some embodiments, from about 5 mol.% to about 25 mol.%, and / or aromatic diols (e.g., BP and / or HQ) in an amount of from about 2 mol.% to about 40 mol.%, and in some embodiments, from about 5 mol.% to about 35 mol.%.

[0025]

[0030] However, in other embodiments, Naphthalene "Low" refers to a polymer in which the total amount of repeat units derived from hydroxycarboxylic acids and / or dicarboxylic acids (e.g., NDA, HNA, or a combination of HNA and NDA) is less than 10 mol.% of the polymer, in some embodiments, about 8 mol.% or less, in some embodiments, about 6 mol.% or less, and in some embodiments, about 1 mol.% to about 5 mol.%. Naphthalene Liquid crystal polymers may be utilized in the composition. In certain embodiments, for example, liquid crystal polymers may be formed from repeat units derived from 4-hydroxybenzoic acid ("HBA"), as well as terephthalic acid ("TA") and / or isophthalic acid ("IA"), and various other optional components. The repeat units derived from 4-hydroxybenzoic acid ("HBA") may comprise from about 10 mol.% to about 80 mol.%, in some embodiments from about 30 mol.% to about 75 mol.%, and in some embodiments, from about 45 mol.% to about 70% of the polymer. Similarly, the repeat units derived from terephthalic acid ("TA") and / or isophthalic acid ("IA") may comprise from about 5 mol.% to about 40 mol.%, in some embodiments from about 10 mol.% to about 35 mol.%, and in some embodiments, from about 15 mol.% to about 35% of the polymer. Additionally, repeat units derived from 4,4'-biphenol ("BP") and / or hydroquinone ("HQ") may be utilized in amounts of from about 1 mol.% to about 30 mol.%, in some embodiments from about 2 mol.% to about 25 mol.%, and in some embodiments from about 5 mol.% to about 20 mol.% of the polymer. Other possible repeat units can include those derived from 6-hydroxy-2-naphthoic acid ("HNA"), 2,6-naphthalenedicarboxylic acid ("NDA"), and / or acetaminophen ("APAP").

[0026]

[0031] The liquid crystalline polymer in the polymer matrix may be present in an amount of about 30 wt.% or more, in some embodiments about 40 wt.% or more, in some embodiments about 40 wt.% to about 99.5 wt.%, in some embodiments about 45 wt.% to about 90 wt.%, and in some embodiments about 50 wt.% to about 85 wt.%, based on the weight of the polymer composition. In certain embodiments, all of the liquid crystalline polymer is present in a "high molecular weight" polymer, such as those described above. Naphthalene In other embodiments, the polymer may be a "low Naphthalene The liquid crystal polymer may preferably be utilized in relatively low amounts only. NaphthaleneThe liquid crystalline polymer may comprise from about 1 wt.% to about 50 wt.%, in some embodiments from about 2 wt.% to about 40 wt.%, in some embodiments from about 5 wt.% to about 30 wt.%, of the total amount of liquid crystalline polymer in the composition, and from about 0.5 wt.% to about 45 wt.%, in some embodiments from about 2 wt.% to about 35 wt.%, in some embodiments from about 5 wt.% to about 25 wt.% of the total composition. In contrast, high Naphthalene The liquid crystalline polymer may comprise from about 50 wt.% to about 99 wt.%, in some embodiments from about 60 wt.% to about 98 wt.%, and in some embodiments from about 70 wt.% to about 95 wt.% of the total amount of liquid crystalline polymer in the composition, and from about 55 wt.% to about 99.5 wt.%, in some embodiments from about 65 wt.% to about 98 wt.%, and in some embodiments from about 75 wt.% to about 95 wt.% of the total composition.

[0027] B. hollow inorganic filler

[0032] To help achieve desired dielectric properties, the polymer composition may include hollow inorganic fillers. For example, these fillers may have a dielectric constant at 100 MHz of about 3.0 or less, in some embodiments about 2.5 or less, in some embodiments about 1.1 to about 2.3, and in some embodiments, about 1.2 to about 2.0. Additionally, hollow inorganic fillers may have a particular size, which can contribute to the strength of the polymer composition and, due to their hollow nature, may allow the polymer composition to have a reduced weight and / or density.

[0028]

[0033] Generally, hollow inorganic fillers have an internal hollow space or cavity and may be synthesized using techniques known in the art. Hollow inorganic fillers may be made from conventional materials. For example, hollow inorganic fillers may include alumina, silica, zirconia, magnesia, glass, fly ash, borates, phosphates, ceramics, etc. In one embodiment, hollow inorganic fillers may include hollow glass fillers, hollow ceramic fillers, and mixtures thereof. In one embodiment, the hollow inorganic filler comprises a hollow glass filler.

[0029]

[0034] The hollow glass filler may be made from soda-lime borosilicate glass, soda-lime glass, borosilicate glass, sodium borosilicate glass, sodium silicate glass, or aluminosilicate glass. In this regard, in one embodiment, the glass composition may be, but is not limited to, at least about 65 wt. % SiO, 3-15 wt. % NaO, 8-15 wt. % CaO, 0.1-5 wt. % MgO, 0.01-3 wt. % AlO, 0.01-1 wt. % KO, and optionally other oxides (e.g., LiO, FeO, TiO, BO). In another embodiment, the composition may be about 50-58 wt. % SiO, 25-30 wt. % AlO, 6-10 wt. % CaO, 1-4 wt. % NaO / KO, and 1-5 wt. % other oxides. Furthermore, in one embodiment, the hollow glass filler may include more alkaline earth metal oxide than alkali metal oxide. For example, the weight ratio of alkaline earth metal oxide to alkali metal oxide may be greater than 1, in some embodiments, greater than about 1.1, in some embodiments, from about 1.2 to about 4, and in some embodiments, from about 1.5 to about 3. Notwithstanding the above, it should be understood that the composition of the glass may vary depending on the type of glass utilized and still provide the benefits desired by the present invention.

[0030]

[0035] The hollow inorganic filler may have at least one dimension having an average value of about 1 micrometer or greater, in some embodiments about 5 micrometers or greater, in some embodiments about 8 micrometers or greater, in some embodiments about 1 micrometer to about 150 micrometers, in some embodiments about 10 micrometers to about 150 micrometers, and in some embodiments about 12 micrometers to about 50 micrometers. In one embodiment, such average value is d 50 It may be referred to as the value.

[0031]

[0036] Additionally, the hollow inorganic filler has a D of about 3 micrometers or greater, in some embodiments about 4 micrometers or greater, in some embodiments from about 5 micrometers to about 20 micrometers, and in some embodiments, from about 6 micrometers to about 15 micrometers. 10 The hollow inorganic filler may have a D of about 10 micrometers or more, in some embodiments about 15 micrometers or more, in some embodiments from about 20 micrometers to about 150 micrometers, and in some embodiments, from about 22 micrometers to about 50 micrometers. 90 may have

[0032]

[0037] In this regard, the hollow inorganic filler may be present in a size distribution that may be Gaussian, normal, or non-normal. In one embodiment, the hollow inorganic filler may have a Gaussian size distribution. In another embodiment, the hollow inorganic filler may have a normal size distribution. In a further embodiment, the hollow inorganic filler may have a non-normal size distribution. Examples of non-normal size distributions can include unimodal and multimodal (e.g., bimodal) size distributions.

[0033]

[0038] When referring to the above dimensions, such dimensions may be any dimensions. However, in one embodiment, such dimensions refer to diameters. For example, such values ​​for dimensions refer to the average diameter of the spheres. Dimensions such as average diameters may be determined according to 3M QCM 193.0. In this regard, in one embodiment, hollow inorganic fillers may refer to hollow spheres, such as hollow glass spheres. For example, hollow inorganic fillers may have an average aspect ratio of approximately 1. Generally, the average aspect ratio may be about 0.8 or greater, in some embodiments, about 0.85 or greater, in some embodiments, about 0.9 to about 1.3, and in some embodiments, about 0.95 to about 1.05.

[0034]

[0039] Additionally, the hollow inorganic fillers may have relatively thin walls to aid in the dielectric properties and weight reduction of the polymer composition, and the wall thickness may be about 50% or less, in some embodiments about 40% or less, in some embodiments about 1% to about 30%, and in some embodiments about 2% to about 25% of the average dimension, e.g., average diameter, of the hollow inorganic fillers.

[0035]

[0040] Furthermore, the hollow inorganic filler may have a specific true density, which allows for easy handling and can provide a polymer composition with reduced weight. Generally, the true density refers to the quotient obtained by dividing the mass of a hollow filler sample by the true volume of the mass of the hollow filler, and the true volume is referred to as the total volume of the hollow filler. In this regard, the true density of the hollow inorganic filler is about 0.1 g / cm 3 or more, in some embodiments, about 0.2 g / cm 3 or more, in some embodiments, about 0.3 g / cm 3 More than ~ approx. 1.2g / cm 3 , and in some embodiments, about 0.4 g / cm 3 More than ~ approx. 0.9g / cm 3 True density may be determined according to 3M QCM 14.24.1.

[0036]

[0041] Even when fillers are hollow, they may possess mechanical strength that allows them to maintain their structural integrity and reduces the likelihood of the fillers breaking during processing and / or use. In this regard, the isotactic crush resistance of hollow inorganic fillers (i.e., at least 80 vol.%, e.g., at least 90 vol.%, of the hollow filler survives) may be about 20 MPa or greater, in some embodiments about 100 MPa or greater, in some embodiments about 150 MPa to about 500 MPa, and in some embodiments about 200 MPa to about 350 MPa. Isotactic crush resistance may be determined according to 3M QCM 14.1.8.

[0037]

[0042] The alkalinity of the hollow inorganic filler may be about 1.0 meq / g or less, in some embodiments about 0.9 meq / g or less, in some embodiments about 0.1 meq / g to about 0.8 meq / g, and in some embodiments about 0.2 meq / g to about 0.7 meq / g. The alkalinity may be determined according to 3M QCM 55.19. To produce a relatively low alkalinity, the hollow inorganic filler may be treated with a suitable acid, such as phosphoric acid.

[0038]

[0043] Furthermore, the hollow inorganic filler may also include a surface treatment to help provide better compatibility with the polymer and / or other components in the polymer composition. For example, the surface treatment may be silanization. In particular, the surface treatment may include, but is not limited to, aminosilane, epoxysilane, etc.

[0039]

[0044] The hollow inorganic filler may, for example, comprise about 1 wt.% or more of the polymer composition, in some embodiments about 4 wt.% or more, in some embodiments about 5 wt.% to about 40 wt.%, and in some embodiments, about 10 wt.% to about 30 wt.%.

[0040] C. Dielectric Filler

[0045] Furthermore, dielectric fillers may also be utilized in the polymer composition to improve the properties of the polymer composition. For example, the dielectric filler may also be capable of reducing the dielectric constant of the polymer composition. Furthermore, the dielectric filler may also contribute to improving other properties of the polymer composition. For example, the dielectric filler may also improve the thermal and mechanical properties of the polymer composition.

[0041]

[0046] These dielectric fillers may be dielectric inorganic fillers, dielectric organic fillers, or mixtures thereof. In one embodiment, the dielectric fillers may be inorganic dielectric fillers. In another embodiment, the dielectric fillers may be organic dielectric fillers. In a further embodiment, the dielectric fillers may be mixtures of inorganic and organic dielectric fillers. Furthermore, in one embodiment, these dielectric fillers may be solid fillers that do not have internal voids.

[0042]

[0047] These dielectric fillers may comprise about 1 wt.% or more of the polymer composition, in some embodiments, about 2 wt.% or more, in some embodiments, about 3 wt.% to about 40 wt.%, and in some embodiments, about 5 wt.% to about 25 wt.%. Furthermore, because hollow inorganic fillers and dielectric fillers each have unique properties, combining them within a specific ratio can provide a polymer composition with beneficial properties, such as a desired balance between dielectric, thermal, and / or mechanical properties. In this regard, the weight ratio of hollow inorganic filler to dielectric filler may be about 0.1 or more, in some embodiments, about 0.1 to about 10, in some embodiments, about 0.1 to about 5, in some embodiments, about 0.5 to about 4, and in some embodiments, about 1 to about 2.

[0043] i. Fibrous fillers

[0048] Fibrous fillers may be utilized in the polymer composition as dielectric fillers. Fibrous fillers typically comprise fibers having a high tensile strength relative to their mass. For example, the ultimate tensile strength of the fibers (determined according to ASTM D2101) is typically from about 1,000 to about 15,000 megapascals ("MPa"), in some embodiments from about 2,000 MPa to about 10,000 MPa, and in some embodiments from about 3,000 MPa to about 6,000 MPa. To help maintain desired dielectric properties, such high-strength fibers may be formed from materials generally of an insulating nature, such as glass, ceramic, or mineral (e.g., alumina or silica), aramid (e.g., Kevlar® sold by EI duPont de Nemours, Wilmington, Delaware), mineral, polyolefin, polyester, and the like.

[0044]

[0049] In one embodiment, the fibrous filler may comprise glass fiber, mineral fiber, or a mixture thereof. For example, in one embodiment, the fibrous filler may comprise glass fiber. Particularly suitable glass fibers may include E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass, and the like. In another embodiment, the fibrous filler may comprise mineral fiber. Mineral fibers may include those derived from silicates, such as neosilicates, sorosilicates, inosilicates (e.g., calcium inosilicates such as wollastonite; calcium magnesium inosilicates such as tremolite; calcium magnesium iron inosilicates such as actinolite; magnesium iron inosilicates such as anthophillite), phyllosilicates (e.g., aluminum phyllosilicates such as palygorskite), tectosilicates, and the like; sulfates such as calcium sulfate (e.g., dehydrated or anhydrite); mineral wool (e.g., rock or slag wool), and the like. Particularly suitable are inosilicates such as wollastonite fiber available from Nyco Minerals under the trade name NYGLOS® (eg, NYGLOS® 4W or NYGLOS® 8).

[0045]

[0050] Furthermore, while fibrous fillers may have a variety of different sizes, fibers with a specific aspect ratio may contribute to improved mechanical properties of polymer compositions. That is, fibrous fillers having an aspect ratio (average length divided by nominal diameter) of about 2 or greater, in some embodiments about 4 or greater, in some embodiments about 5 to about 50, and in some embodiments about 8 to about 40 may be particularly beneficial. Such fibrous fillers may have a weight-average length of, for example, about 10 micrometers or greater, in some embodiments about 25 micrometers or greater, in some embodiments about 50 micrometers to about 800 micrometers, and in some embodiments about 60 micrometers to about 500 micrometers. Furthermore, such fibrous fillers may have a volume-average length of, for example, about 10 micrometers or greater, in some embodiments about 25 micrometers or greater, in some embodiments about 50 micrometers to about 800 micrometers, and in some embodiments about 60 micrometers to about 500 micrometers.

[0046]

[0051] The fibrous filler may similarly have a nominal diameter of about 5 micrometers or greater, in some embodiments about 6 micrometers or greater, in some embodiments about 8 micrometers to about 40 micrometers, and in some embodiments, about 9 micrometers to about 20 micrometers. The relative amount of fibrous filler may also be selectively controlled to help achieve desired mechanical and thermal properties without adversely affecting other properties of the polymer composition, such as its flowability and dielectric properties. In this regard, the fibrous filler may have a dielectric constant at a frequency of about 6 or less, in some embodiments about 5.5 or less, in some embodiments about 1.1 to about 5, and in some embodiments about 2 to about 4.8.

[0047]

[0052] The fibrous filler may be modified or unmodified and may be sized or chemically treated, for example, to improve adhesion to plastics. In some cases, glass fibers may be sized to protect them, smooth them, and improve adhesion between the fibers and the matrix material. If present, the sizing may include silanes, film-forming agents, lubricants, wetting agents, adhesives, optional antistatic agents and plasticizers, emulsifiers, and optionally additional additives. In one particular embodiment, the sizing may include silanes. Specific examples of silanes include aminosilanes such as 3-trimethoxysilylpropylamine, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(3-trimethoxysilanylpropyl)ethane-1,2-diamine, 3-(2-aminoethyl-amino)propyltrimethoxysilane, and N-[3-(trimethoxysilyl)propyl]-1,2-ethane-diamine.

[0048] ii. Particulate fillers

[0053] Particulate fillers may also be utilized in the polymer compositions as dielectric fillers to help achieve desired properties and / or color. Particulate clay minerals may be particularly suitable for use in the present invention. Examples of such clay minerals include, for example, talc (MgSiO 10 (OH2), halloysite (Al2Si2O5(OH)4), kaolinite (Al2Si2O5(OH)4), illite ((K,H3O)(Al,Mg,Fe)2(Si,Al)4O 10 [(OH)2,(H2O)]), montmorillonite (Na,Ca) 0.33 (Al,Mg)2SiO 10 (OH)2.nH2O), vermiculite ((MgFe,Al)3(Al,Si)4O 10 (OH)2.4H2O), palygorskite ((Mg,Al)2Si4O 10 (OH).4(H2O)), pyrophyllite (Al2Si4O 10(OH)2), and the like, and combinations thereof. Still other particulate fillers can be utilized instead of, or in addition to, clay minerals. For example, other suitable particulate silicate fillers, such as mica, diatomaceous earth, and the like, can also be utilized. For example, mica may be a particularly suitable mineral for use in the present invention. As used herein, the term "mica" refers to muscovite (KAl2(AlSi3)O 10 (OH)2), biotite (K(Mg,Fe)3(AlSi3)O 10 (OH)2), phlogopite (KMg3(AlSi3)O 10 (OH)2), red mica (K(Li,Al) 2-3 (AlSi3)O 10 (OH)2), glauconite (K,Na)(Al,Mg,Fe)2(Si,Al)4O 10 (OH)2), and combinations thereof.

[0049]

[0054] The particulate filler may be in modified or unmodified form and may be treated, for example, to improve properties. In some examples, the particulate filler may be fluorinated, for example, as a coating. Fluorinated additives may be utilized to improve the processing of polymer compositions, for example, by providing better mold filling, internal lubrication, mold release, etc. In certain embodiments, the fluorinated additive may include a fluoropolymer containing a hydrocarbon backbone polymer in which some or all of the hydrogen atoms are substituted with fluorine atoms. The backbone polymer may be polyolefinic and formed from an unsaturated olefin monomer substituted with fluorine. The fluoropolymer may be a homopolymer of such a fluorine-substituted monomer, a copolymer of a fluorine-substituted monomer, or a mixture of a fluorine-substituted monomer and a non-fluorine-substituted monomer. In addition to the fluorine atoms, the fluoropolymer may be substituted with other halogen atoms, such as chlorine and bromine atoms. Representative monomers suitable for forming the fluoropolymer used in the present invention are tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, perfluoroethyl vinyl ether, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, etc., and mixtures thereof. Specific examples of suitable fluoropolymers include polytetrafluoroethylene, perfluoroalkyl vinyl ether, poly(tetrafluoroethylene-co-perfluoroalkyl vinyl ether), fluorinated ethylene propylene copolymer, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, etc., and mixtures thereof. The fluorinated additive may contain only the fluoropolymer, or may include other components, such as those that aid its ability to be uniformly dispersed in the polymer composition. For example, in one embodiment, the fluorinated additive may include a fluoropolymer in combination with a plurality of carrier particles. For example, in such an embodiment, the fluoropolymer may be coated on carrier particles, such as the particulate fillers described above.

[0050] D. functional compound

[0055] If desired, functional compounds can also be utilized in the polymer composition, particularly to facilitate a reduction in the melt viscosity of the polymer composition. For example, the functional compound can be a functional aromatic compound, a non-aromatic functional compound, or a mixture thereof. For example, in one embodiment, the polymer composition can include a non-aromatic functional compound. Such compounds can serve various purposes, such as reducing the melt viscosity. One such non-aromatic functional compound is water. If desired, water can be added in a form that generates water under process conditions. For example, water can be added as a hydrate that effectively "lose" water under process conditions (e.g., elevated temperatures). Such hydrates include alumina trihydrate, copper sulfate pentahydrate, barium chloride dihydrate, calcium sulfate dehydrate, and the like, and combinations thereof. In one particular embodiment, the hydrate can include alumina trihydrate.

[0051]

[0056] When utilized, functional compounds such as hydrates may comprise about 0.001 wt.% or more, in some embodiments about 0.005 wt.% or more, in some embodiments about 0.005 wt.% to about 2 wt.%, and in some embodiments, about 0.01 wt.% to about 1 wt.% of the polymer composition.

[0052] E. Laser Activatable Additives

[0057] The polymer composition may be "laser activatable" in the sense that it contains an additive that can be activated by a laser direct structuring ("LDS") process. In such a process, the additive is exposed to a laser that causes the liberation of metal. The laser thereby patterns the conductive elements in the part, leaving behind a roughened surface containing embedded metal particles. These particles act as nuclei for crystal growth during a subsequent plating process (e.g., copper plating, gold plating, nickel plating, silver plating, zinc plating, tin plating, etc.).

[0053]

[0058] The laser activatable additive generally comprises a spinel crystal, which may comprise two or more metal oxide cluster configurations within a definable crystal formation. For example, the entire crystal formation may have the following general formula: AB2O4 (In the formula, A is a metal cation having a valence of 2, such as cadmium, chromium, manganese, nickel, zinc, copper, cobalt, iron, magnesium, tin, titanium, etc., and combinations thereof; B is a metal cation having a valence of 3, such as chromium, iron, aluminum, nickel, manganese, tin, and combinations thereof. may have

[0054]

[0059] Typically, A in the above formula provides the primary cation component of the first metal oxide cluster, and B provides the primary cation component of the second metal oxide cluster. These oxide clusters may have the same or different structures. For example, in one embodiment, the first metal oxide cluster has a tetrahedral structure, and the second metal oxide cluster has an octahedral cluster. Nevertheless, the clusters can combine to provide a single, identifiable crystalline structure with enhanced sensitivity to electromagnetic radiation. Examples of suitable spinel crystals include, for example, MgAl2O4, ZnAl2O4, FeAl2O4, CuFe2O4, CuCr2O4, MnFe2O4, NiFe2O4, TiFe2O4, FeCr2O4, and MgCr2O4. Copper chromium oxide (CuCr2O4) is particularly suitable for use in the present invention and is available from Shepherd Color Co. under the name "Shepherd Black 1GM."

[0055]

[0060] The laser activatable additive may comprise from about 0.1 wt.% to about 30 wt.%, in some embodiments from about 0.5 wt.% to about 20 wt.%, and in some embodiments, from about 1 wt.% to about 10 wt.% of the polymer composition.

[0056] F. Other additives

[0061] A wide variety of additional additives may also be included in the polymer composition, such as lubricants, thermally conductive fillers, pigments, antioxidants, stabilizers, surfactants, waxes, flame retardants, anti-sag additives, nucleating agents (e.g., boron nitride), flow modifiers, coupling agents, antimicrobial agents, pigments or other colorants, impact modifiers, and other materials added to improve properties and processability. Such optional materials may be utilized in the polymer composition in conventional amounts and in accordance with conventional processing techniques. When utilized, for example, such additives typically comprise from about 0.05 wt.% to about 5 wt.%, and in some embodiments, from about 0.1 wt.% to about 1 wt.%, of the polymer composition.

[0057]

[0062] In one embodiment, the polymer composition may include a lubricant. For example, the lubricant may include a polyolefin wax (e.g., polyethylene wax), an amide wax, a fatty acid ester wax, or the like. In one embodiment, the lubricant may include a polyolefin wax such as a polyethylene wax. The lubricant may also be a fatty acid ester wax. The fatty acid ester wax may be obtained, for example, by oxidative bleaching of crude natural wax followed by esterification of the fatty acid with an alcohol. The alcohol may, in some cases, have 1 to 4 hydroxyl groups and 2 to 20 carbon atoms. When the alcohol is polyfunctional (e.g., 2 to 4 hydroxyl groups), an alcohol having 2 to 8 carbon atoms is particularly desirable. Particularly suitable polyfunctional alcohols include dihydric alcohols (e.g., ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,4-cyclohexanediol), trihydric alcohols (e.g., glycerol and trimethylolpropane), and tetrahydric alcohols (e.g., pentaerythritol and erythritol). Aromatic alcohols such as o-, m-, and p-tolylcarbinol, chlorobenzyl alcohol, bromobenzyl alcohol, 2,4-dimethylbenzyl alcohol, 3,5-dimethylbenzyl alcohol, 2,3,5-cumobenzyl alcohol, 3,4,5-trimethylbenzyl alcohol, p-cuminyl alcohol, 1,2-phthalyl alcohol, 1,3-bis(hydroxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, pseudocumenyl glycol, mesitylene glycol, and mesityleneglycerol may also be suitable. Fatty acid esters particularly suitable for use in the present invention are derived from montan wax. For example, Licowax® OP (Clariant) contains montanic acid partially esterified with butylene glycol and partially saponified with calcium hydroxide. Thus, Licowax® OP contains a mixture of montanic acid esters and calcium montanate.Other Montan acid esters that may be utilized include, for example, Licowax® E, Licowax® OP, and Licolub® WE 4 (all manufactured by Clariant), which are Montan acid esters obtained as secondary products from the oxidative refining of raw Montan wax. Licowax® E and Licolub® WE 4 contain Montan acid esterified with ethylene glycol or glycerin.

[0058]

[0063] In one embodiment, the polymer composition may include a black pigment. The black pigment typically includes a plurality of carbon black particles, such as furnace black, channel black, acetylene black, or lamp black. The carbon black particles may have any desired shape, such as granules or flakes. The average particle size (e.g., diameter) may range, for example, from about 1 to about 200 nanometers, in some embodiments from about 5 to about 150 nanometers, and in some embodiments, from about 10 to about 100 nanometers. Furthermore, it is typically desirable for the carbon black particles to be relatively pure, e.g., containing polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene, naphthalene, etc.) in an amount of about 1 parts per million ("ppm") or less, and in some embodiments, about 0.5 ppm or less. For example, the black pigment may contain benzo[a]pyrene in an amount of about 10 parts per billion ("ppb") or less, and in some embodiments, about 5 ppb or less.

[0059]

[0064] If desired, the black pigment of the polymer composition may include a carrier resin capable of encapsulating the carbon black particles, thereby providing various benefits. For example, the carrier resin may improve the ability of the particles to be handled and incorporated into the base polymer composition. While any known carrier resin may be utilized for this purpose, in certain embodiments, the carrier resin is a liquid crystalline polymer, which may be the same or different from the polymer utilized in the polymer composition. If desired, the carrier resin may be preblended with the carbon black particles to form a pigment masterbatch, which may then be combined with the polymer. When utilized, the carrier resin typically comprises from about 50 wt.% to about 95 wt.%, in some embodiments from about 60 wt.% to about 90 wt.%, and in some embodiments, from about 70 wt.% to about 85 wt.%, of the masterbatch, and the carbon black particles typically comprise from about 5 wt.% to about 50 wt.%, in some embodiments, from about 10 wt.% to about 40 wt.%, and in some embodiments, from about 15 wt.% to about 30 wt.% of the masterbatch. Of course, other ingredients may also be incorporated into the masterbatch.

[0060] II. formation

[0065] The components used to form the polymer composition may be combined together using any of a variety of different techniques known in the art. For example, in one particular embodiment, the liquid crystalline polymer, hollow inorganic filler, and other optional additives are melt-processed as a mixture in an extruder to form the polymer composition. The mixture may be melt-mixed in a single-screw or multi-screw extruder at a temperature of about 250°C to about 450°C. In one embodiment, the mixture can be melt-processed in an extruder containing multiple temperature zones. The temperature of each zone is typically set within about -60°C to about 25°C of the melt temperature of the liquid crystalline polymer. By way of example, the mixture can be melt-processed using a twin-screw extruder, such as a Leistritz 18mm co-rotating, fully intermeshing twin-screw extruder. A general-purpose screw design can be used to melt-process the mixture. In one embodiment, the mixture containing all of the components can be fed into the feed throat of the first barrel by a metering feeder. In another embodiment, different components can be added at different addition points in the extruder, as is known. For example, the liquid crystal polymer can be applied to a feed inlet, and specific additives (e.g., hollow inorganic fillers) can be added downstream at the same or different temperature zones. In either case, the resulting mixture can be melted, mixed, and then extruded through a die. The extruded polymer composition can then be quenched in a water bath to solidify, pelletized in a pelletizer, and then dried.

[0061]

[0066] The melt viscosity of the polymer composition is generally low enough to allow it to flow easily into a mold cavity and form a small sized circuit board. For example, in one particular embodiment, the polymer composition has a melt viscosity of 1,000 s -1The polymer may have a melt viscosity of about 5 Pa·s or greater, in some embodiments about 10 Pa·s or greater, in some embodiments about 10 Pa·s to about 500 Pa·s, in some embodiments about 5 Pa·s to about 150 Pa·s, in some embodiments about 5 Pa·s to about 100 Pa·s, in some embodiments about 10 Pa·s to about 100 Pa·s, in some embodiments about 15 to about 90 Pa·s, and in some embodiments about 20 Pa·s to about 60 Pa·s, as determined at a shear rate of 100 Pa·s to about 90 Pa·s. The melt viscosity may be determined in accordance with IEC 611443:2005.

[0062]

[0067] The polymer composition may also have a relatively low density, for example, a density of about 3 g / cm 3 or less, in some embodiments, about 2.5 g / cm 3 or less, in some embodiments, about 0.1 g / cm 3 ~About 2g / cm 3 , and in some embodiments, about 0.5 g / cm 3 ~Approx. 1.6g / cm 3 The density may be determined according to ISO 1183.

[0063]

[0068] Additionally, polymer compositions are described in U.S. Pat. No. 6,495,616, which is incorporated herein by reference, and have the following formula: X=100×[(100 / ρ0+α / ρ1+β / ρ3)-(100+α+β) / ρ](α / ρ1-α / ρ2) (wherein α represents the amount of hollow inorganic filler (parts by weight based on 100 parts by weight of the liquid crystal polymer), β represents the amount of dielectric (e.g., fibrous) filler (parts by weight based on 100 parts by weight of the liquid crystal polymer), ρ0 represents the specific gravity of the liquid crystal polymer, ρ1 represents the true specific gravity of the hollow inorganic filler, ρ2 represents the material specific gravity of the hollow inorganic filler, ρ3 represents the specific gravity of the dielectric (e.g., fibrous) filler, and ρ represents the specific gravity of an ASTM No. 4 dumbbell (having a thickness of 2.5 mm) obtained by injection molding the liquid crystal polymer composition. In one embodiment, X may be 10 to 50. In another embodiment, X may be less than 10 or greater than 50. For example, in one embodiment, X may be less than 10. In another embodiment, X may be greater than 50.

[0064] III. Molded parts

[0069] Once formed, the polymer composition can be molded into the shape desired for a particular application. Typically, molded parts are formed using a one-component injection molding process in which dried and preheated plastic granules are injected into a mold.

[0065]

[0070] In one embodiment, the molded part or shape may be a thin-walled electrical connector. The thin-walled electrical connector may have a variety of configurations within the scope of the present disclosure. By way of example, the thin-walled connector may define multiple passages or spaces between opposing walls. The passages may accommodate contact pins and facilitate electrical connection with multiple individual pins.

[0066]

[0071] The electrical connector may also be very compact as a result of the polymer composition from which it is formed. For example, the polymer composition may exhibit excellent flow characteristics for forming the very small features required to form the electrical connectors described herein, while simultaneously exhibiting minimal warpage upon exposure to heat. In this regard, the walls may have relatively thin respective widths "w" of about 500 micrometers or less, in some embodiments about 400 micrometers or less, in some embodiments, from about 25 micrometers to about 350 micrometers, and in some embodiments, from about 50 micrometers to about 300 micrometers.

[0067]

[0072] One particularly preferred thin-walled electrical connector 100 according to an embodiment of the present invention is shown in Figure 1A. Figure 1B is an enlarged view of the thin-walled connector 100 of Figure 1A. As shown, an insertion passage or space 225 capable of accommodating contact pins and facilitating multiple individual electrical connections is defined between opposing walls 224. The thin-walled electrical connector 100 may be very compact. More specifically, the walls 224 may have respective widths "w" that are relatively thin, such as within the ranges discussed above.

[0068]

[0073] FIG. 2 illustrates another embodiment of a thin-walled electrical connector 200. The connector 200 may include a board side C2 that may be attached to the surface of a circuit board P. The connector 200 may also include a wiring side C1 that is structured to couple to the board connector C2 to connect individual electrical wires 3 to the circuit board P. The board side C2 may include a first housing 10 having a mating recess 10a into which the wiring connector C1 is mated and an elongated configuration in the width direction of the housing 10. The wiring side C1 may also include a second housing 20 that is elongated in the width direction of the housing 20. The second housing 20 may have multiple terminal-receiving cavities 22 arranged parallel to the width direction, creating a two-tiered array including upper and lower terminal-receiving cavities 22. Terminals 5 attached to the distal ends of the individual electrical wires 3 may be received in each of the terminal-receiving cavities 22. If desired, the housing 20 may also be provided with locking portions 28 (engagements) that correspond to connecting members (not shown) of the board connector C2.

[0069]

[0074] As discussed above, the interior walls of first housing 10 and / or second housing 20 may be relatively thin (e.g., may have a relatively small width dimension) and may be formed from the polymer composition of the present invention.

[0070]

[0075] As shown, the electrical connector may be formed from a polymer composition having a relatively low dielectric constant and dissipation factor. In this regard, the electrical connector can also reduce or prevent interference (e.g., "crosstalk") between signals transmitted to adjacent or nearby pins due to the dielectric properties of the polymer composition from which it is formed. Providing a composition with such dielectric properties can help minimize signal loss and improve performance when utilized in certain applications, such as signal transmission applications, particularly those related to 5G communications. As used herein, "5G" generally refers to high-speed data communications via radio frequency signals. 5G networks and systems can communicate data at much higher speeds than previous generations of data communications standards (e.g., "4G," "LTE"). Various standards and specifications quantifying the requirements for 5G communications have been published. As one example, the International Telecommunications Union (ITU) published the International Mobile Telecommunications-2020 ("IMT-2020") standard in 2015. The IMT-2020 standard defines various data transmission criteria for 5G (e.g., downlink and uplink data rates, latency, etc.). The IMT-2020 standard specifies uplink and downlink peak data rates as the minimum data rates for uploading and downloading data that 5G systems must support. The IMT-2020 standard sets the downlink peak data rate requirement at 20 Gbit / s and the uplink peak data rate at 10 Gbit / s.

[0071]

[0076] Another example is 3 rdThe Third Generation Partnership Project (3GPP®) recently published a new standard for 5G called "5G NR." 3GPP® published "Release 15" in 2018, defining "Phase 1" as the standardization of 5G NR. 3GPP® defines the 5G frequency band as "Frequency Range 1" (FR1), which generally includes frequencies below 6 GHz, and "Frequency Range 2" (FR2), which is the frequency band in the range of 20-60 GHz. However, as used herein, "5G frequency" can also refer to systems utilizing frequencies greater than 60 GHz, for example, in the ranges up to 80 GHz, up to 150 GHz, and up to 300 GHz. As used herein, "5G frequency" may refer to frequencies of about 2.5 GHz or higher, in some embodiments about 3.0 GHz or higher, in some embodiments about 3 GHz to about 300 GHz or higher, in some embodiments about 4 GHz to about 80 GHz, in some embodiments about 5 GHz to about 80 GHz, in some embodiments about 20 GHz to about 80 GHz, and in some embodiments about 28 GHz to about 60 GHz.

[0072]

[0077] The connectors described herein can be used in radio frequency systems that meet or may be considered "5G" standards based on standards published by 3GPP (registered trademark), such as Release 15 (2018), and / or the IMT-2020 standard. To achieve such high-speed data communications at high frequencies, antenna elements and arrays typically utilize small feature sizes / spacings (e.g., fine-pitch technology) and / or advanced materials that can improve antenna performance. For example, feature sizes (spacings between antenna elements, widths of antenna elements), etc., typically depend on the wavelength (λ) of the desired transmit and / or receive radio frequency propagating through the dielectric of the substrate on which the antenna elements are formed (e.g., nλ / 4, where n is an integer). Additionally, beamforming and / or beamsteering can be utilized to facilitate transmission and reception across multiple frequency ranges or channels (e.g., MIMO, massive MIMO).

[0073]

[0078] Referring to Figure 3, a 5G communication system 300 may include a base station 302, one or more relay stations 304, one or more user computing devices 306, one or more Wi-Fi repeaters 308 (e.g., "femtocells"), and / or a 5G antenna system 300 The base station 302 may include other suitable antenna components. The relay station 304 may be configured to relay or "repeat" signals between the base station 302 and the user computing device 306 and / or relay station 304 to facilitate communication with the base station 302 by the user computing device 306 and / or other relay station 304. The base station 302 may include a MIMO antenna array 310 configured to receive and / or transmit radio frequency signals 312 with the relay station 304, a Wi-Fi repeater 308, and / or directly with the user computing device 306. The user computing device 306 is not necessarily limited by the present invention and includes devices such as 5G smartphones.

[0074]

[0079] The MIMO antenna array 310 may utilize beam steering to focus or direct the radio frequency signals 312 toward the relay station 304. For example, the MIMO antenna array 310 may be configured to adjust an elevation angle 314 relative to a heading angle 316 defined in the XY and / or ZY planes, as well as relative to the Z direction.

[0075]

[0080] Similarly, relay stations 304, user computing devices 306, Wi-Fi repeaters 308 One or more of the devices 304, 306, 308 may utilize beam steering to directionally tune the sensitivity and / or power transmission of the devices 304, 306, 308 relative to the MIMO antenna array 310 of the base station 302 (e.g., by adjusting the relative elevation of each device). By adjusting one or both of the antenna angles and / or relative azimuth angles, reception and / or transmission capabilities for the MIMO antenna array 310 can be improved.

[0076]

[0081] Electrical connectors may be utilized to communicatively couple various elements of the base station 302, relay station 304, and / or user computing device 306. For example, the base station 302, relay station 304, and / or user computing device 306. Such antennas and / or antenna arrays may be communicatively coupled to one or more integrated circuits, processors, memories, etc. For example, a front-end module may be used to control the transmission and / or reception of radio frequency signals using the antennas and / or antenna arrays. Electrical connectors may communicatively couple any of the above devices.

[0077]

[0082] The present invention may be better understood with reference to the following examples. [Example]

[0078] Test Method

[0083] Melt viscosity: Melt viscosity (Pa s) was measured using a Dynisco LCR7001 capillary rheometer at a shear rate of 1,000 s -1 and may be determined according to ISO Test No. 11443:2005 at a temperature 15°C above the melt temperature (e.g., about 350°C). The rheometer orifice (die) had a diameter of 1 mm, a length of 20 mm, an L / D ratio of 20.1, and an entrance angle of 180°. The barrel diameter was 9.55 mm + 0.005 mm, and the rod length was 233.4 mm.

[0079]

[0084] Melting Temperature: The melting temperature ("Tm") may be determined by differential scanning calorimetry ("DSC") as known in the art. The melting temperature is the differential scanning calorimetry (DSC) peak melting temperature as determined by ISO Test No. 11357-2:2013. Based on the DSC procedure, DSC measurements performed on a TA Q2000 instrument were used, with samples heated and cooled at 20°C per minute as described in ISO Standard 10350.

[0080]

[0085] Deflection Temperature Under Load ("DTUL"): Deflection temperature under load may be determined according to ISO Test No. 75-2:2013 (technically equivalent to ASTM D648-07). More specifically, a specimen sample 80 mm long, 10 mm thick, and 4 mm wide may be subjected to an edgewise three-point bend test with a specified load (maximum external fiber stress) of 1.8 megapascals. The specimen is lowered into a silicone oil bath and the temperature is increased at 2°C per minute until the specimen deflects 0.25 mm (0.32 mm per ISO Test No. 75-2:2013).

[0081]

[0086] Tensile modulus, tensile stress, and tensile elongation: Tensile properties may be tested according to ISO Test No. 527:2012 (technically equivalent to ASTM D638-14). Modulus and strength measurements may be performed on the same specimen sample, 80 mm long, 10 mm thick, and 4 mm wide. The test temperature may be about 23°C, and the test speed may be 1 or 5 mm / min.

[0082]

[0087] Flexural Modulus, Flexural Stress, and Flexural Elongation: Flexural properties may be tested according to ISO Test No. 178:2010 (technically equivalent to ASTM D790-10). This test may be performed on a support span of 64 mm. Testing may be performed at the center of an uncut ISO 3167 multipurpose bar. The test temperature may be approximately 23°C, and the test speed may be 2 mm / min.

[0083]

[0088] Unnotched and Notched Charpy Impact Strength: Charpy properties may be tested according to ISO Test No. ISO 179-1:2010 (technically equivalent to ASTM D256-10, Method B). This test may be performed using a Type 1 specimen size (80 mm length, 10 mm width, and 4 mm thickness). When testing notched impact strength, the notch may be a Type A notch (0.25 mm base radius). Specimens may be cut from the center of the multipurpose bar using a single-tooth milling machine. The test temperature may be approximately 23°C.

[0084]

[0089] Dielectric constant ("Dk") and dissipation factor ("Df"): The dielectric constant (or relative static permittivity) and dissipation factor are determined by Baker-Jarvis et al., IEEE Trans. on Dielectric and Electrical Insulation, 5(4), 571 (1998) and Krupka et al., Proc. th It is determined using a known split-post dielectric resonance method, such as that described in International Conference on Dielectric Materials: Measurements and Applications, IEEE Conference Publication No. 430 (September 1996). More specifically, a plate-shaped sample measuring 80 mm x 80 mm x 1 mm was inserted between two fixed dielectric resonators. The resonators measured the dielectric constant components at the surface of the specimen. Five samples were tested, and the average value was recorded. The split-post resonator can be used to perform dielectric measurements in the low gigahertz range, e.g., 1 GHz, 2 GHz, or 10 GHz.

[0085] Example 1

[0090] Samples 1-5 were prepared from liquid crystal polymers (LCP1 or LCP2), hollow glass spheres, and mica, wollastonite, glass powder, and / or glass fibers. LCP1 was prepared from 43% HBA, 9% TA, 29% HQ, and 20% NDA. LCP2 was prepared from 48% HNA, 2% HBA, 25% BP, and 25% TA. The hollow glass spheres had an average diameter of 18 micrometers. The glass powder had a dielectric constant of 4.8 determined at a frequency of 1 GHz. Additionally, the utilized glass fibers had an initial length of either 3 mm or 4 mm. The polymer compositions may also contain polyethylene lubricant, alumina trihydrate, pigments, and / or various other minor additives. Compounding was performed using a 25 mm single-screw extruder.

[0086] [Table 1]

[0087]

[0091] The samples were then tested for thermal and mechanical properties, and the results are listed in Table 2 below.

[0088] [Table 2]

[0089] Example 2

[0092] Sample 7 was prepared from liquid crystal polymers (LCP2 and LCP4), hollow glass spheres, glass powder, glass fiber, and alumina trihydrate. LCP4 was prepared from 60% HBA, 4% HNA, 18% TA, and 18% BP. The glass powder had a dielectric constant of 4.8 determined at a frequency of 1 GHz. Compounding was carried out using a 25 mm single-screw extruder.

[0090] [Table 3]

[0091]

[0093] The samples were then tested for thermal and mechanical properties, and the results are listed in Table 4 below.

[0092] [Table 4]

[0093]

[0094] These and other modifications and variations of the present invention may be practiced by those skilled in the art without departing from the spirit and scope of the present invention. Furthermore, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those skilled in the art will appreciate that the foregoing description is merely illustrative, and thus does not limit the invention as further described in the appended claims. The claims as filed are as follows: [Claim 1] a polymer matrix containing at least one thermotropic liquid crystalline polymer; and At least one hollow inorganic filler having a dielectric constant of about 3.0 or less at a frequency of 100 MHz. a weight ratio of the at least one thermotropic liquid crystalline polymer to the at least one hollow inorganic filler of about 0.1 to about 10; The polymer composition exhibits a dielectric constant of about 4 or less and a dissipation factor of about 0.02 or less, determined at a frequency of 10 GHz. [Claim 2] 2. The polymer composition of claim 1, wherein the weight ratio of the at least one thermotropic liquid crystal polymer to the at least one hollow inorganic filler is about 2 to about 6. [Claim 3] 3. The polymer composition of claim 1 or 2, exhibiting a dielectric constant of about 3.5 or less and a dissipation factor of about 0.005 or less, determined at a frequency of 10 GHz. [Claim 4] 4. The polymer composition according to claim 1, wherein the thermotropic liquid crystal polymer is an aromatic polyester containing repeating units derived from 4-hydroxybenzoic acid. [Claim 5] The thermotropic liquid crystal polymer is about 10 mol.% or more Naphthalene Hydroxycarboxylic acids and / or Naphthalene 5. The polymer composition of claim 1, having a total amount of repeat units derived from a dicarboxylic acid. [Claim 6] 6. The polymer composition of claim 5, wherein the thermotropic liquid crystal polymer has a total amount of repeat units derived from naphthalene-2,6-dicarboxylic acid of about 10 mol.% or more. [Claim 7] 7. The polymer composition of claim 1, wherein the thermotropic liquid crystalline polymer is present in an amount of about 40 wt.% or more. [Claim 8] 8. The polymer composition of claim 1, wherein the at least one hollow inorganic filler comprises hollow glass spheres. [Claim 9] 9. The polymer composition of claim 8, wherein the hollow glass spheres have an aspect ratio of about 0.8 to about 1.2. [Claim 10] 9. The polymer composition of claim 8, wherein the hollow glass spheres have an average diameter of about 1 micrometer to about 150 micrometers. [Claim 11] 11. The polymer composition of claim 10, wherein the wall thickness of the hollow glass spheres is no more than about 40% of the average diameter of the hollow glass spheres. [Claim 12] 12. The polymer composition of claim 1, wherein the at least one hollow inorganic filler is present in an amount of about 5 wt.% to about 40 wt.%. [Claim 13] 13. The polymer composition of claim 1, further comprising at least one dielectric filler. [Claim 14] 14. The polymer composition of claim 13, wherein the at least one dielectric filler comprises a fibrous filler, a particulate filler, or a mixture thereof. [Claim 15] 14. The polymer composition of claim 13, wherein the fibrous filler comprises glass fibers. [Claim 16] 14. The polymer composition of claim 13, wherein the fibrous filler comprises wollastonite. [Claim 17] 14. The polymer composition of claim 13, wherein the particulate filler comprises mica. [Claim 18] 17. The polymer composition of claim 16, wherein the mica is modified with a fluorinated additive. [Claim 19] 14. The polymer composition of claim 13, wherein the at least one dielectric filler is present in an amount of about 3 wt.% to about 40 wt.%. [Claim 20] 14. The polymer composition of claim 13, wherein the thermotropic liquid crystalline polymer is present in an amount of about 50 wt.% or more, the at least one hollow inorganic filler is present in an amount of about 5 wt.% to about 40 wt.%, and the at least one dielectric filler is present in an amount of about 3 wt.% to about 40 wt.%. [Claim 21] 21. The polymer composition of claim 1, further comprising a hydrate. [Claim 22] 22. The polymer composition of any of claims 1 to 21, further comprising a polyethylene wax. [Claim 23] 23. The polymer composition of any of claims 1 to 22, having a deflection temperature under load of about 200°C or greater at 1.8 MPa, determined according to ISO 75. [Claim 24] 24. The polymer composition of any of claims 1 to 23, having a tensile strength of about 40 MPa or greater, determined according to ISO 527. [Claim 25] Approximately 3 kJ / m determined according to ISO 179 2 25. The polymer composition according to claim 1, having a notched Charpy impact strength of at least 1000 kJ / cm2. [Claim 26] Determined according to ISO 1183, approximately 2.5 g / cm 326. The polymer composition of any of claims 1 to 25, having a density of: [Claim 27] 1,000 seconds -1 27. The polymer composition of claim 1, having a melt viscosity of about 10 Pa s to about 100 Pa s determined at a shear rate of 100 Pa s and a temperature 20° C. above the melting temperature of the at least one polymer. [Claim 28] 28. The polymer composition of any of claims 1 to 27, further comprising a laser activatable additive. [Claim 29] The laser activatable additive has the following general formula: AB2O4 (In the formula, A is a metal cation having a valence of 2; B is a metal cation with a valence of 3 29. The polymer composition of claim 28, containing spinel crystals having the formula: [Claim 30] 29. The polymer composition of claim 28, wherein the spinel crystals comprise MgAl2O4, ZnAl2O4, FeAl2O4, CuFe2O4, CuCr2O4, MnFe2O4, NiFe2O4, TiFe2O4, FeCr2O4, MgCr2O4, or combinations thereof. [Claim 31] 31. A molded part comprising the polymer composition of any of claims 1 to 30. [Claim 32] 32. An electrical connector formed from the molded component of claim 31.

Claims

1. a polymer matrix containing at least one thermotropic liquid crystalline polymer; and 5 wt. % to 40 wt. % of at least one hollow inorganic filler comprising hollow glass spheres having a dielectric constant of 3.0 or less at a frequency of 100 MHz. a weight ratio of said at least one thermotropic liquid crystalline polymer to said at least one hollow inorganic filler is 0.1 to 10; The polymer composition exhibits a relative dielectric constant of 3.2 or less and a dielectric loss tangent of 0.02 or less, determined at a frequency of 10 GHz, the thermotropic liquid crystal polymer has a total amount of repeat units derived from naphthalenehydroxycarboxylic acid and / or naphthalenedicarboxylic acid of 10 mol % or more, and repeat units derived from aromatic dicarboxylic acid constitute 15 mol % to 60 mol % of the thermotropic liquid crystal polymer, and The polymer composition comprises glass fibers having a dielectric constant of 5.5 or less at a frequency of 1 GHz. The polymer composition.

2. 2. The polymer composition of claim 1, wherein the weight ratio of said at least one thermotropic liquid crystalline polymer to said at least one hollow inorganic filler is 2-6.

3. 3. The polymer composition of claim 1 or 2, exhibiting a dielectric constant of 3.14 or less and a dissipation factor of 0.005 or less, determined at a frequency of 10 GHz.

4. 4. The polymer composition according to claim 1, wherein the thermotropic liquid crystal polymer is an aromatic polyester containing repeating units derived from 4-hydroxybenzoic acid.

5. 5. The polymer composition according to claim 1, wherein the thermotropic liquid crystal polymer has a total amount of repeating units derived from naphthalenehydroxycarboxylic acid and / or naphthalenedicarboxylic acid of 12 mol. % or more.

6. 6. The polymer composition according to claim 5, wherein the thermotropic liquid crystal polymer has a total amount of repeating units derived from naphthalene-2,6-dicarboxylic acid of 10 mol. % or more.

7. 7. The polymer composition of claim 1, wherein the thermotropic liquid crystalline polymer is present in an amount of 40 wt. % or more.

8. 10. The polymer composition of claim 1, wherein the hollow glass spheres have an aspect ratio of 0.8 to 1.

2.

9. 10. The polymer composition of claim 1, wherein the hollow glass spheres have an average diameter of from 1 micrometer to 150 micrometers.

10. 10. The polymer composition of claim 9, wherein the wall thickness of the hollow glass spheres is no more than 40% of the average diameter of the hollow glass spheres.

11. 11. The polymer composition according to any of claims 1 to 10, wherein the at least one hollow inorganic filler is present in an amount of 5 wt.% to 40 wt.%.

12. 12. The polymer composition of any of claims 1 to 11, further comprising at least one dielectric filler.

13. 13. The polymer composition of claim 12, wherein the at least one dielectric filler comprises a second fibrous filler, a particulate filler, or a mixture thereof.

14. The polymer composition of claim 13 , wherein the second fibrous filler comprises glass fibers.

15. 14. The polymer composition of claim 13, wherein the second fibrous filler comprises wollastonite.

16. The polymer composition of claim 13 , wherein the particulate filler comprises mica.

17. 17. The polymer composition of claim 16, wherein the mica is modified with a fluorinated additive.

18. 13. The polymer composition of claim 12, wherein the at least one dielectric filler is present in an amount of 3 wt. % to 40 wt. %.

19. 13. The polymer composition of claim 12, wherein the thermotropic liquid crystalline polymer is present in an amount of 50 wt. % or more, the at least one hollow inorganic filler is present in an amount of 5 wt. % to 40 wt. %, and the at least one dielectric filler is present in an amount of 3 wt. % to 40 wt. %.

20. 20. The polymer composition of any of claims 1 to 19, further comprising a hydrate.

21. 21. The polymer composition of any of claims 1 to 20, further comprising a polyethylene wax.

22. 22. The polymer composition of any of claims 1 to 21, having a deflection temperature under load at 1.8 MPa of 200°C or greater, determined according to ISO 75.

23. 23. A polymer composition according to any of the preceding claims, having a tensile strength, determined according to ISO 527, of 40 MPa or greater.

24. 3 kJ / m determined according to ISO 179 ２ 24. The polymer composition of claim 1, having a Charpy notched impact strength of at least 1000 kJ / cm2.

25. 2.5 g / cm determined according to ISO 1183 ３ 25. The polymer composition of any of claims 1 to 24, having a density:

26. 1,000 seconds －１ and a temperature 20° C. above the melting temperature of said at least one polymer.

27. 27. The polymer composition of any of claims 1 to 26, further comprising a laser activatable additive.

28. The laser activatable additive has the following general formula: AB ２ 4 ４ (In the formula, A is a metal cation having a valence of 2; B is a metal cation having a valence of 3.

28. The polymer composition of claim 27, containing spinel crystals having the formula:

29. The spinel crystal is 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 ４ or a combination thereof.

30. 30. A molded part comprising the polymer composition of any of claims 1 to 29.

31. 31. An electrical connector formed from the molded component of claim 30.

32. A polymer matrix containing at least one thermotropic liquid crystalline polymer; and 5 wt. % to 40 wt. % of at least one hollow inorganic filler comprising hollow glass spheres having a dielectric constant of 3.0 or less at a frequency of 100 MHz. a weight ratio of said at least one thermotropic liquid crystalline polymer to said at least one hollow inorganic filler is 0.1 to 10; The polymer composition exhibits a relative dielectric constant of 3.2 or less and a dielectric loss tangent of 0.02 or less, determined at a frequency of 10 GHz, and the thermotropic liquid crystal polymer has a total amount of repeating units derived from naphthalene-2,6-dicarboxylic acid of 10 mol % or more, and repeating units derived from aromatic dicarboxylic acids constitute 15 mol % to 60 mol % of the thermotropic liquid crystal polymer. The polymer composition.

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