WO2019213920A1

WO2019213920A1 - Polymer composition with reduced dielectric constant

Info

Publication number: WO2019213920A1
Application number: PCT/CN2018/086389
Authority: WO
Inventors: Xiangbing PENG; Min Wang; Xiang YUAN
Original assignee: Ticona LLC
Current assignee: Ticona LLC
Priority date: 2018-05-10
Filing date: 2018-05-10
Publication date: 2019-11-14
Anticipated expiration: 2020-11-10

Abstract

A polymer composition contains special fillers for plastic dielectrical and other properties adjustment. In general, the composition contains a base resin and a polymeric filler, such as a polyethylene (e.g., ultrahigh molecular weight polyethylene). The polymeric filler may reduce the dielectric constant of the base resin, the dissipation factor of the base resin, or both.

Description

POLYMER COMPOSITION WITH REDUCED DIELECTRIC CONSTANT

BACKGROUND

Low dielectric materials find use in many applications, such as in insulating electrical components from other conductors. In many cases, low dielectric materials are employed in high frequency applications in which stable performance is not guaranteed. In some cases, ceramics are used, but ceramics are hard and brittle, posing many challenges for processing and durability.

Plastics may also provide suitable low dielectric materials, but stable properties are often hard to achieve. For example, the dielectric constant and dissipation factor of a particular plastic may vary widely based on the method of manufacture. Environmental variables, such as the temperature and moisture content of the plastic, may also cause drastic variation of the electrical properties of the material.

Some attempts to provide a low dielectric plastic material aim to incorporate filler particles, such as hollow or porous inorganic fillers. In such examples, the dielectric properties are directly linked to the geometry of the embedded filler particles, and the properties remain vulnerable to particle variance and a number of processing sensitivities (e.g., filler breakdown during mixing steps) .

In view of the above, a need exists for a special filler for the adjustment of the dielectric behavior and other properties of a plastic.

SUMMARY

In general, the present disclosure is directed to a polymer composition having a relatively low dielectric constant (D _k) and/or dissipation factor (D _f) . In accordance with the present disclosure, a polymeric filler is incorporated into a matrix polymer that dramatically reduces the dielectric constant and/or the dissipation factor of the matrix polymer. In addition, the polymeric filler can also reduce density. Further components and additives can also be incorporated into the composition for further reducing the dielectric constant and for improving the bonding characteristics of the polymer composition to metals, such as treated metals.

In one embodiment, for instance, the present disclosure is directed to a polymer composition having electrical insulating properties. The polymer composition includes a semi-crystalline aromatic thermoplastic polymer. The thermoplastic polymer is generally present in the composition in an amount of at least 40%by weight, such as in an amount of at least 45%by weight, such as in an amount of at least 50%by weight. The semi-crystalline aromatic thermoplastic polymer, for instance, may comprise a polyester such as polybutylene terephthalate or a polyarylene sulfide such as a polyphenylene sulfide. In accordance with the present disclosure, a polymeric filler is incorporated into the polymer composition that comprises high density polyethylene particles. The polymeric filler is present in the polymer composition sufficient to lower the dielectric constant of the thermoplastic polymer by more than about 2%, such as by more than about 2.5%, such as more than about 3%, such as more than about 3.5%, such as more than about 4%when tested at a frequency of 2.5 GHz.

Optionally, the polymer composition can contain glass fibers for further reducing the dielectric constant. The glass fibers, for instance, may be selected so as to have a dielectric constant of less than about 6, such as less than about 5.5, such as less than about 5, such as less than about 4.5 when measured at a frequency of 1 GHz. The glass fibers can be present in the polymer composition in an amount from 0%to about 35%by weight, such as in an amount from about 15%to about 25%by weight.

In one embodiment, the polymer composition contains an epoxy-functional polymer. The epoxy-functional polymer, for instance, can be present in the composition in an amount greater than about 2%by weight, such as in an amount greater than about 4%by weight, and generally less than about 15%by weight, such as less than about 10%by weight. In one embodiment, the epoxy-functional polymer comprises a polyethylene grafted with glycidyl methacrylate.

In one particular embodiment, the polymer composition contains a polybutylene terephthalate polymer in an amount from about 45%to about 70%by weight, glass fibers in an amount from about 15%to about 25%by weight, an epoxy-functional polymer in an amount from about 3%to about 8%by weight, and the polymeric filler in an amount from about 8%to about 25%by weight.

The polymeric filler as described above can comprise high density polyethylene particles, such as ultrahigh molecular weight polyethylene particles. The high density polyethylene particles, for instance, can have a particle size (e.g., a D50) of from about 10 μm to about 300 μm and can have a molecular weight of from about 1,000,000 g/mol to about 10,000,000 g/mol.

The polymer composition of the present disclosure can be used in various and numerous applications. In one embodiment, for instance, the polymer composition can be bonded with a metal, such as through injection molding. For instance, an article can be formed that includes a metal substrate bonded to the polymer composition.

The polymer composition can be used in electrical components. For instance, the polymer composition can be formed into a case for an electronic device such as a mobile phone, a computer antenna cover, a projector cover, or used to form a connector. The polymer composition can also be used as a coating for a cable or wire. In yet another embodiment, the polymer composition can be used to form auto parts, such as interior or exterior automotive parts.

Other features and aspects of the present disclosure are discussed in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying figures:

Fig. 1 is a perspective view of one embodiment of a wire or cable made in accordance with the present disclosure;

Fig. 2 is a perspective view of a cover for a mobile phone made in accordance with the present disclosure; and

Fig. 3 is a perspective view of a cable connector that may be made in accordance with the present disclosure.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present disclosure.

In general, the present disclosure is directed to a polymer composition containing a base resin and a polymeric filler. In accordance with the present disclosure, the polymer composition is formulated so as to have a relatively low dielectric constant (D _k) and/or a dissipation factor (D _f) . In one embodiment, for instance, the base resin comprises a semi-crystalline aromatic thermoplastic polymer and the polymeric filler comprises high density polyethylene particles, such as ultrahigh molecular weight polyethylene particles. The high density polyethylene particles have been found to dramatically reduce the dielectric constant and/or the dissipation factor of the thermoplastic polymer. In addition, the polymeric filler can also reduce the density of the polymer composition without experiencing problems related to delamination.

The polymer composition of the present disclosure is particularly well suited for use in applications for protecting electrical components. For instance, the polymer composition can be bonded with metals through injection molding, can be used to mold covers for mobile phones, can be used to cover computer antennas, and can be used in other applications that require lower dielectric constants such as in signal transfer applications, such as related to 4G or 5G communications.

The dielectric constant D _k is also known as the relative permittivity, or the relative static permittivity in some cases. Generally, D _k represents a number of ratios between physical quantities, with examples including the ratio between the absolute permittivity of a material and the vacuum permittivity and the ratio between the electrical flux density and the field strength through a material, for example. Additionally, the capacitance of a material is directly proportional to D _k; for example, the capacitance C of a parallel plate capacitor is calculated as

C = D _k × D _vac × A × d ^-1

where D _vac is the vacuum permittivity, A is the area of one capacitor plate, and d is the distance between plates.

The dissipation factor D _f is related to the amount of energy absorbed and dissipated by a capacitive material when subjected to an electrical field. That is, D _f represents one measure of the efficiency of a dielectric. A low D _f material may, in some embodiments, minimize the amount of energy dissipated as heat from both conducting and insulating components.

Advantageously, the polymeric filler according to the present disclosure may be configured to reduce or minimize the D _k, D _f, or both, of a base resin. Additionally, the resulting polymer composition may possess good stability of properties, including stability of D _k, D _f, or both. When combined with other appropriately selected ingredients, a polymer composition prepared as herein may furnish other desirable attributes, such as low density or good adherence to substrates (e.g., treated or untreated metal substrates) . The polymeric filler may augment, assist, or otherwise work in conjunction with traditional dielectric filler materials, such as a glass filler (e.g., glass fiber or beads) .

Of further advantage, the polymeric filler of the present disclosure may provide the beneficial attributes mentioned above with a reduced proclivity to degradation, such as degradation via delamination induced by mismatched flow properties and polarity between the base resin and the polymeric filler.

The base resin may be generally selected from any of a variety of polymers or combinations of polymers. Suitable polymers may include, for instance, polyamides (e.g., aromatic polyamides) , polyesters, polyarylene sulfides, polyetherimides, polyphenylene oxides, polyarylketones (e.g., polyetheretherketone, polyetherketoneketone, etc. ) , etc., as well as blends thereof.

For example, aromatic polymers are suitable, as such polymers are generally considered “high performance” polymers that they have a relatively high glass transition temperature and/or high melting temperature. Such high performance aromatic polymers can thus provide a substantial degree of heat resistance to the resulting polymer composition. For example, the aromatic polymer may have a glass transition temperature of about 40℃ or more, in some embodiments about 50℃ or more, and in some embodiments, from about 60℃ to about 320℃. The aromatic polymer may also have a melting temperature of about 200℃ or more, in some embodiments from about 210℃ to about 400℃, and in some embodiments, from about 220℃ to about 380℃. The glass transition and melting temperatures may be determined as is well known in the art using differential scanning calorimetry ( "DSC" ) , such as determined by ISO Test No. 11357-2: 2013 (glass transition) and 11357-3: 2011 (melting) .

One example of a semi-crystalline aromatic polymer, for instance, is an aromatic polyester that is a condensation product of an aromatic dicarboxylic acid having 8 to 14 carbon atoms and at least one diol. Suitable diols may include, for instance, neopentyl glycol, cyclohexanedimethanol, 2, 2-dimethyl-1, 3-propane diol and aliphatic glycols of the formula HO (CH ₂) _nOH where n is an integer of 2 to 10. Suitable aromatic dicarboxylic acids may include, for instance, isophthalic acid, terephthalic acid, 1, 2-di (p-carboxyphenyl) ethane, 4, 4′-dicarboxydiphenyl ether, etc., as well as combinations thereof. Fused rings can also be present such as in 1, 4-or 1, 5-or 2, 6-naphthalene-dicarboxylic acids. Particular examples of such aromatic polyesters may include, for instance, poly (ethylene terephthalate) (PET) , poly (1, 4-butylene terephthalate) (PBT) , poly (1, 3-propylene terephthalate) (PPT) , poly (1, 4-butylene 2, 6-naphthalate) (PBN) , poly (ethylene 2, 6-naphthalate) (PEN) , poly (1, 4-cyclohexylene dimethylene terephthalate) (PCT) , and copolymers and mixtures of the foregoing.

In one embodiment, for instance, the matrix polymer used in the polymer composition is a polybutylene terephthalate polymer. The polybutylene terephthalate polymer may have a crystallinity of greater than about 38%, such as greater than about 40%, such as greater than about 45%. The crystallinity of the polybutylene terephthalate polymer is generally less than about 70%. Percent crystallinity may be determined using differential scanning calorimetry (DSC) . Such analysis may be performed using a Pyris 6 DSC from PerkinElmer instruments. A detailed description of the calculation is available from Sichina, W.J. "DSC as problem solving tool: measurement of percent crystallinity of thermoplastics. " Thermal Analysis Application Note (2000) .

Those skilled in the art will appreciate that the degree of crystallinity of a given polyester may depend upon the monomers used to form the polymer, the process temperatures during formation of the polymer, the process used to make the polymer, and/or the molecular structure of the polyester. In one embodiment, the degree of crystallinity of a polyester can be altered by changing the amount and/or type and/or distribution of monomer units that make up the polyester chain. For example, if about 3 to about 15 mole percent of the ethylene glycol repeat units in poly ethylene terephthalate are replaced with 1, 4-cydohexanedimethanol repeat units, or by di-ethylene glycol repeat units, the resulting modified polyester can be amorphous and has a low melt processing temperature. Similarly, if about 10 to about 20 mole percent of the terephthalic acid repeat units in polyethylene terephthalate (or polybutylene terephthalate) are replaced with isophthalic acid repeat units, the resulting modified polyester can also be amorphous and have a low melt processing temperature. Such concepts can also be combined into one polyester or by melt mixing at least two different polyesters. Accordingly, the choice of a particular modifying acid or diol can significantly affect the melt processing properties of the polyester.

As used herein, the terms “modifying acid” and “modifying diol” are meant to define compounds, which can form part of the acid and diol repeat units of a polyester, respectively, and which can modify a polyester to reduce its crystallinity or render the polyester amorphous. In one embodiment, however, the polyesters present in the polymer composition of the present disclosure are non-modified and do not contain a modifying acid or a modifying diol.

Examples of modifying acid components may include, but are not limited to, isophthalic acid, phthalic acid, 1, 3-cyclohexanedicarboxylic acid, 1, 4-cyclohexane dicarboxylic acid, 2, 6-naphthaline dicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, suberic acid, 1, 12-dodecanedioic acid, and the like. In practice, it is often preferable to use a functional acid derivative thereof such as the dimethyl, diethyl, or dipropyl ester of the dicarboxylic acid. The anhydrides or acid halides of these acids also may be employed where practical. Preferred is isophthalic acid.

Examples of modifying diol components may include, but are not limited to, neopentyl glycol, 1, 4-cyclohexanedimethanol, 1, 2-propanediol, 1, 3-propanediol, 2-Methy-1, 3-propanediol, 1, 4-butanediol, 1, 6-hexanediol, 1, 2-cyclohexanediol, 1, 4-cyclohexanediol, 1, 2-cyclohexanedimethanol, 1, 3-cyclohexanedimethanol, 2, 2, 4, 4-tetramethyl 1, 3-cyclobutane diol, Z, 8-bis (hydroxymethyltricyclo- [5.2.1.0] -decane wherein Z represents 3, 4, or 5; 1, 4-Bis (2-hydroxyethoxy) benzene, 4, 4′-Bis (2-hydroxyethoxy) diphenylether [Bis-hydroxyethyl Bisphenol A] , 4, 4′-Bis (2-hydroxyethoxy) diphenylsulfide [Bis-hydroxyethyl Bisphenol S] and diols containing one or more oxygen atoms in the chain, e.g. diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and the like. In general, these diols contain 2 to 18, preferably 2 to 8 carbon atoms. Cycloalphatic diols can be employed in their cis or trans configuration or as mixtures of both forms.

In some examples, at least one polyester or copolyester present in the composition may have an intrinsic viscosity (IV) of from about 0.5 to about 0.9 dL/g, such as from about 0.5 to about 0.8 dL/g. In one embodiment, for instance, the intrinsic viscosity of the polyester is from about 0.65 to about 0.8 dL/g.

Polyarylene sulfides are also suitable semi-crystalline aromatic polymers. The polyarylene sulfide may be homopolymers or copolymers. For instance, selective combination of dihaloaromatic compounds can result in a polyarylene sulfide copolymer containing not less than two different units. For instance, when p-dichlorobenzene is used in combination with m-dichlorobenzene or 4, 4'-dichlorodiphenylsulfone, a polyarylene sulfide copolymer can be formed containing segments having the structure of formula:

and segments having the structure of formula:

or segments having the structure of formula:

The polyarylene sulfide may be linear, semi-linear, branched or crosslinked. Linear polyarylene sulfides, in some embodiments, contain 80 mol%or more of the repeating unit – (Ar–S) –. For example, the polyarylene sulfide can be a polyphenylene sulfide (PPS) , such as a linear PPS, defined herein as containing the phenylene sulfide structure – (C ₆H ₄–S) _n– (wherein n is an integer of 1 or more) as a component thereof. Such linear polymers may also include a small amount of a branching unit or a cross-linking unit, but the amount of branching or cross-linking units may, in some embodiments, be less than about 1 mol%of the total monomer units of the polyarylene sulfide. A linear polyarylene sulfide polymer may be a random copolymer or a block copolymer containing the above-mentioned repeating unit. Semi-linear polyarylene sulfides may likewise have a cross-linking structure or a branched structure introduced into the polymer a small amount of one or more monomers having three or more reactive functional groups. By way of example, monomer components used in forming a semi-linear polyarylene sulfide can include an amount of polyhaloaromatic compounds having two or more halogen substituents per molecule which can be utilized in preparing branched polymers. Such monomers can be represented by the formula R'X _n, where each X is selected from chlorine, bromine, and iodine, n is an integer of 3 to 6, and R'is a polyvalent aromatic radical of valence n which can have up to about 4 methyl substituents, the total number of carbon atoms in R'being within the range of 6 to about 16. Examples of some polyhaloaromatic compounds having more than two halogens substituted per molecule that can be employed in forming a semi-linear polyarylene sulfide include 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene, 1, 3-dichloro-5-bromobenzene, 1, 2, 4-triiodobenzene, 1, 2, 3, 5-tetrabromobenzene, hexachlorobenzene, 1, 3, 5-trichloro-2, 4, 6-trimethylbenzene, 2, 2', 4, 4'-tetrachlorobiphenyl, 2, 2', 5, 5'-tetra-iodobiphenyl, 2, 2', 6, 6'-tetrabromo-3, 3', 5, 5'-tetramethylbiphenyl, 1, 2, 3, 4-tetrachloronaphthalene, 1, 2, 4-tribromo-6-methylnaphthalene, etc., and mixtures thereof.

At least one base resin is present in the polymer composition in an amount sufficient to form a continuous phase. For example, the base resin may be present in the polymer composition in an amount of at least about 40 wt. %, such as in an amount of at least about 45 wt. %, such as in an amount of at least 50 wt. %, such as in an amount of at least about 55 wt. %, such as at least about 65 wt. %, such as at least about 70 wt. %. In some embodiments, the base resin is present in an amount less than about 98 wt. %, such as less than about 90 wt. %, such as less than about 85 wt. %, such as less than about 70 wt. %, such as less than about 60 wt. %.

The polymeric filler may be generally selected from a polyethylene polymer. As used herein, a polyethylene polymer refers to a polymer made from over 90%ethylene derived units, such as greater than 95%ethylene derived units, or 100%ethylene derived units. The polyethylene can be a homopolymer or a copolymer, including a terpolymer, having other monomeric units. In one embodiment, the polyethylene particles are made from a high density polyethylene. A high density polyethylene has a density of about 0.93 g/cm ³ or greater. The polyethylene used to produce the particles can comprise a high molecular weight polyethylene, a very high molecular weight polyethylene, and/or an ultrahigh molecular weight polyethylene. "High molecular weight polyethylene" refers to polyethylene compositions with weight-average molecular weight of at least about 3x10 ⁵ g/mol and, as used herein, is intended to include very-high molecular weight polyethylene and ultra-high molecular weight polyethylene. For purposes of the present specification, the molecular weights referenced herein are determined in accordance with the Margolies equation ( "Margolies molecular weight" ) .

"Very-high molecular weight polyethylene" refers to polyethylene compositions with a weight average molecular weight of less than about 3x10 ⁶ g/mol and more than about 1x10 ⁶ g/mol. In some embodiments, the molecular weight of the very-high molecular weight polyethylene composition is between about 2x10 ⁶ g/mol and less than about 3x10 ⁶ g/mol.

"Ultra-high molecular weight polyethylene" refers to polyethylene compositions with weight-average molecular weight of at least about 3x10 ⁶ g/mol. In some embodiments, the molecular weight of the ultra-high molecular weight polyethylene composition is between about 3x10 ⁶ g/mol and about 30x10 ⁶ g/mol, or between about 3x10 ⁶ g/mol and about 20x10 ⁶ g/mol, or between about 3x10 ⁶ g/mol and about 10x10 ⁶ g/mol, or between about 3x10 ⁶ g/mol and about 6x10 ⁶ g/mol.

As described above, in one embodiment, the polyethylene is a homopolymer of ethylene. In another embodiment, the polyethylene may be a copolymer. For instance, the polyethylene may be a copolymer of ethylene and another olefin containing from 3 to 16 carbon atoms, such as from 3 to 10 carbon atoms, such as from 3 to 8 carbon atoms. These other olefins include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methylpent-1-ene, 1-decene, 1-dodecene, 1-hexadecene and the like. Also utilizable herein are polyene comonomers such as 1, 3-hexadiene, 1, 4-hexadiene, cyclopentadiene, dicyclopentadiene, 4-vinylcyclohex-1-ene, 1, 5-cyclooctadiene, 5-vinylidene-2-norbornene and 5-vinyl-2-norbornene. However, when present, the amount of the non-ethylene monomer (s) in the copolymer may be less than about 10 mol. %, such as less than about 5 mol. %, such as less than about 2.5 mol. %, such as less than about 1 mol. %, wherein the mol. %is based on the total moles of monomer in the polymer.

In one embodiment, the polyethylene may have a monomodal molecular weight distribution. Alternatively, the polyethylene may exhibit a bimodal molecular weight distribution. For instance, a bimodal distribution generally refers to a polymer having a distinct higher molecular weight and a distinct lower molecular weight (e.g. two distinct peaks) on a size exclusion chromatography or gel permeation chromatography curve. In another embodiment, the polyethylene may exhibit more than two molecular weight distribution peaks such that the polyethylene exhibits a multimodal (e.g., trimodal, tetramodal, etc. ) distribution. Alternatively, the polyethylene may exhibit a broad molecular weight distribution wherein the polyethylene is comprised of a blend of higher and lower molecular weight components such that the size exclusion chromatography or gel permeation chromatography curve does not exhibit at least two distinct peaks but instead exhibits one distinct peak broader than the individual component peaks.

In one embodiment, the composition may be comprised of more than one polyethylene, each having a different molecular weight and/or molecular weight distribution. For instance, the molecular weight distribution may be within the average molecular weight specifications provided above.

In addition, the composition may be comprised of a blend of one or more polyethylene polymers or copolymers and another thermoplastic polymer such as a polypropylene, a polybutylene, a polymethylpentene, a linear low density polyethylene, or mixtures thereof. However, the amount of non-polyethylene polymer (s) in the composition may be less than about 10 wt. %, such as less than about 5 wt. %, such as less than about 2.5 wt. %, such as less than about 1 wt. %, wherein the wt %is based on the total weight of the composition.

Any method known in the art can be utilized to synthesize the polyethylene. The polyethylene powder is, in some cases, produced by the catalytic polymerization of ethylene monomer or optionally with one or more other 1-olefin co-monomers, the 1-olefin content in the final polymer being less or equal to 10%of the ethylene content, with a heterogeneous catalyst and an organo aluminum or magnesium compound as cocatalyst. The ethylene is usually polymerized in gaseous phase or slurry phase at relatively low temperatures and pressures. The polymerization reaction may be carried out at a temperature of between 50℃. and 100℃. and pressures in the range of 0.02 and 2 MPa.

The molecular weight of the polyethylene can be adjusted by adding hydrogen. Altering the temperature and/or the type and concentration of the co-catalyst may also be used to fine tune the molecular weight. Additionally, the reaction may occur in the presence of antistatic agents to avoid fouling and product contamination.

Suitable catalyst systems include but are not limited to Ziegler-Natta type catalysts. In some cases, Ziegler-Natta type catalysts are derived by a combination of transition metal compounds of Groups 4 to 8 of the Periodic Table and alkyl or hydride derivatives of metals from Groups 1 to 3 of the Periodic Table. Transition metal derivatives used usually comprise the metal halides or esters or combinations thereof. Exemplary Ziegler-Natta catalysts include those based on the reaction products of organo aluminum or magnesium compounds, such as for example but not limited to aluminum or magnesium alkyls and titanium, vanadium or chromium halides or esters. The heterogeneous catalyst might be either unsupported or supported on porous fine grained materials, such as silica or magnesium chloride. Such support can be added during synthesis of the catalyst or may be obtained as a chemical reaction product of the catalyst synthesis itself.

In one embodiment, a suitable catalyst system can be obtained by the reaction of a titanium (IV) compound with a trialkyl aluminum compound in an inert organic solvent at temperatures in the range of -40℃. to 100℃., preferably -20℃. to 50℃. The concentrations of the starting materials are in the range of 0.1 to 9 mol/L, preferably 0.2 to 5 mol/L, for the titanium (IV) compound and in the range of 0.01 to 1 mol/L, preferably 0.02 to 0.2 mol/L for the trialkyl aluminum compound. The titanium component is added to the aluminum component over a period of 0.1 min to 60 min, preferably 1 min to 30 min, the molar ratio of titanium and aluminum in the final mixture being in the range of 1: 0.01 to 1: 4.

In another embodiment, a suitable catalyst system is obtained by a one or two-step reaction of a titanium (IV) compound with a trialkyl aluminum compound in an inert organic solvent at temperatures in the range of -40℃. to 200℃., preferably -20℃. to 150℃. In the first step the titanium (IV) compound is reacted with the trialkyl aluminum compound at temperatures in the range of -40℃. to 100℃., preferably -20℃. to 50℃. using a molar ratio of titanium to aluminum in the range of 1: 0.1 to 1: 0.8. The concentrations of the starting materials are in the range of 0.1 to 9.1 mol/L, preferably 5 to 9.1 mol/L, for the titanium (IV) compound and in the range of 0.05 and 1 mol/L, preferably 0.1 to 0.9 mol/L for the trialkyl aluminum compound. The titanium component is added to the aluminum compound over a period of 0.1 min to 800 min, preferably 30 min to 600 min. In a second step, if applied, the reaction product obtained in the first step is treated with a trialkyl aluminum compound at temperatures in the range of -10℃. to 150℃., preferably 10℃. to 130℃. using a molar ratio of titanium to aluminum in the range of 1: 0.01 to 1: 5.

In yet another embodiment, a suitable catalyst system is obtained by a procedure wherein, in a first reaction stage, a magnesium alcoholate is reacted with a titanium chloride in an inert hydrocarbon at a temperature of 50° to 100℃. In a second reaction stage the reaction mixture formed is subjected to heat treatment for a period of about 10 to 100 hours at a temperature of 110° to 200℃. accompanied by evolution of alkyl chloride until no further alkyl chloride is evolved, and the solid is then freed from soluble reaction products by washing several times with a hydrocarbon.

In a further embodiment, catalysts supported on silica, such as for example the commercially available catalyst system Sylopol 5917 can also be used.

Using such catalyst systems, the polymerization is normally carried out in suspension at low pressure and temperature in one or multiple steps, continuous or batch. The polymerization temperature may be, in some embodiments, in the range of 30℃. to 130℃., preferably is the range of 50℃. and 90℃. and the ethylene partial pressure may be, in some embodiments, less than 10 MPa, preferably 0.05 and 5 MPa. Trialkyl aluminums, like for example but not limited to isoprenyl aluminum and triisobutyl aluminum, are used as co-catalyst such that the ratio of Al: Ti (co-catalyst versus catalyst) is in the range of 0.01 to 100: 1, more preferably is the range of 0.03 to 50: 1. The solvent is an inert organic solvent as may be used for Ziegler type polymerizations. Examples are butane, pentane, hexane, cyclohexene, octane, nonane, decane, their isomers and mixtures thereof. The polymer molecular mass is controlled through feeding hydrogen. The ratio of hydrogen partial pressure to ethylene partial pressure is in the range of 0 to 50, preferably the range of 0 to 10. The polymer is isolated and dried in a fluidized bed drier under nitrogen. The solvent may be removed through steam distillation in case of using high boiling solvents. Salts of long chain fatty acids may be added as a stabilizer. Some examples are calcium, magnesium and zinc stearate.

Optionally, other catalysts such as Phillips catalysts, metallocenes and post metallocenes may be employed. Generally a cocatalyst such as alumoxane or alkyl aluminum or alkyl magnesium compound is also employed. Other suitable catalyst systems include Group 4 metal complexes of phenolate ether ligands.

Ultrahigh-molecular-weight polyethylene (UHMW-PE) can be employed for example as a powder, in particular as a micro powder. The UHMW-PE generally has a mean particle diameter D ₅₀ (volume based and determined by light scattering) in the range of 1 to 5000 μm, preferably from 10 to 500 μm and particularly preferably from 10 to 300 μm, such as 50 to 200 μm or 120 to 180 μm. In one embodiment, the polyethylene particles can be a free-flowing powder. The powder particle size can be measured utilizing a laser diffraction method according to ISO 13320. In one embodiment, 90%of the polyethylene particles can have a particle size of less than about 250 microns. In other embodiments, 90%of the polyethylene particles can have a particle size of less than about 200 microns.

The molecular weight of the polyethylene polymer can vary depending upon the particular application. The polyethylene polymer, for instance, may have an average molecular weight, as determined according to the Margolies equation. The molecular weight can be determined by first measuring the viscosity number according to DIN EN ISO Test 1628. Dry powder flow is measured using a 25 mm nozzle. The molecular weight is then calculated using the Margolies equation from the viscosity numbers, of at least or greater than about 500,000 g/mol, such as greater than about 1,000,000 g/mol, such as greater than about 1,500,000 g/mol, such as greater than about 2,000,000 g/mol, such as greater than about 2,500,000 g/mol, such as greater than about 3,000,000 g/mol, such as greater than about 3,500,000 g/mol, such as greater than about 4,000,000 g/mol. The average molecular weight is generally less than about 12,000,000 g/mol, such as less than about 10,000,000.

The polyethylene may have a viscosity number of from at least 100 mL/g, such as at least 500 mL/g, such as at least 1,500 mL/g, such as at least 2,000 mL/g, such as at least 2,500 mL/g to less than about 6,000 mL/g, such as less than about 5,000 mL/g, such as less than about 4000 mL/g, such as less than about 3,000 mL/g, as determined according to ISO 1628 part 3 utilizing a concentration in decahydronapthalene of 0.0002 g/mL. The polyethylene can have a melt flow rate determined at 190℃ and at a load of 21.6 kg of less than 1 g/10 min, such as less than about 0.5 g/10 min, such as less than about 0.1 g/10 min and generally greater than 0.001 g/10 min when determined according to ISO Test 1133.

The polyethylene may have a crystallinity of from at least about 40%to 85%, such as from 45%to 80%.

Suitable UHMW-PE is commercially available from Ticona GmbH, Germany under the tradename

In one embodiment, the ultrahigh molecular weight polyethylene can be present in an amount up to about 40 wt. %, in an amount ranging from about 5 to 35 wt. %, in an amount ranging from about 8 to 30 wt. %, such as about 8 to 25 wt. %, such as about 8 to 22 wt. %, e.g.

In one embodiment, the polymeric filler is added to the polymer composition in an amount sufficient for the polymer composition to have desired dielectric properties. For instance, the polymeric filler can be added to the polymer composition in an amount sufficient to reduce the dielectric constant of the matrix polymer by at least about 2%, such as by at least about 2.5%, such as by at least about 3%, such as by at least about 3.5%, such as by at least about 4%. The dielectric constant is generally reduced up to about 20%, such as up to about 15%. In one embodiment, the dielectric constant of the polymer composition is less than about 3, such as less than about 2.95, such as less than about 2.9, such as less than about 2.8, and generally greater than about 1.5. The dielectric constant of the polymer composition is measured at a frequency of 2.5 GHz.

In one embodiment, the polymeric filler is added to the polymer composition in an amount sufficient to have a desirable influence on the dissipation factor. For instance, the polymeric filler can be added so as to decrease the dissipation factor of the matrix polymer by greater than about 5%, such as greater than about 10%, such as greater than about 15%, such as greater than about 18%, such as greater than about 20%, such as greater than about 22%, such as greater than about 25%, such as greater than about 27%. The dissipation factor is generally reduced by an amount up to about 50%. In one embodiment, the dissipation factor of the polymer composition is less than about 0.01, such as less than about 0.009, such as less than about 0.008 and is generally greater than about 0.001.

As described above, the polymeric filler can also reduce the density of the matrix polymer. For instance, the density of the matrix polymer can be reduced by greater than about 4%, such as greater than about 5%, such as greater than about 6%, such as greater than about 7%, such as greater than about 8%, such as greater than about 9%, such as greater than about 10%. The density of the matrix polymer can be decreased up to about 20%. In one embodiment, the density of the polymeric composition is less than about 1.4 kg/m ³, such as less than about 1.35 kg/m ³, such as less than about 1.3 kg/m ³ and is generally greater than about 1 kg/m ³.

An epoxy-functionalized component may be present in some embodiments of a polymer composition prepared as disclosed herein. In some examples, the epoxy-functionalized component may contribute an impact modifying effect, a toughening effect, a metal-ion adsorbing effect (e.g., promoting adherence to a metallic substrate) , or combinations thereof. Epoxy-functionalized, as used herein, indicates the presence of epoxy functional groups in each molecule of the component, such as one, two, or more functional groups per molecule. In some embodiments, the epoxy-functionalized component may contain an olefinic monomeric unit that is derived from one or more α-olefins. Examples of such monomers include, for instance, linear and/or branched α-olefins having from 2 to 20 carbon atoms and, in some cases, from 2 to 8 carbon atoms. Specific examples include ethylene, propylene, 1-butene; 3-methyl-1-butene; 3, 3-dimethyl-1-butene; 1-pentene; 1-pentene with one or more methyl, ethyl or propyl substituents; 1-hexene with one or more methyl, ethyl or propyl substituents; 1-heptene with one or more methyl, ethyl or propyl substituents; 1-octene with one or more methyl, ethyl or propyl substituents; 1-nonene with one or more methyl, ethyl or propyl substituents; ethyl, methyl or dimethyl-substituted 1-decene; 1-dodecene; and styrene. Particularly desired α-olefin monomers are ethylene and propylene.

The epoxy-functionalized component may also contain an epoxy-functional monomeric unit. One example of such a unit is an epoxy-functional (meth) acrylic monomeric component. As used herein, the term “ (meth) acrylic” includes acrylic and methacrylic monomers, as well as salts or esters thereof, such as acrylate and methacrylate monomers. For example, suitable epoxy-functional (meth) acrylic monomers may include, but are not limited to, those containing 1, 2-epoxy groups, such as glycidyl acrylate and glycidyl methacrylate. Other suitable epoxy-functional monomers include allyl glycidyl ether, glycidyl ethacrylate, and glycidyl itoconate. Other suitable monomers may also be employed to help achieve the desired molecular weight.

Of course, the epoxy-functionalized component may also contain other monomeric units as is known in the art. For example, another suitable monomer may include a (meth) acrylic monomer that is not epoxy-functional. Examples of such (meth) acrylic monomers may include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, s-butyl acrylate, i-butyl acrylate, t-butyl acrylate, n-amyl acrylate, i-amyl acrylate, isobornyl acrylate, n-hexyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate, methylcyclohexyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, i-propyl methacrylate, i-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, i-amyl methacrylate, s-butyl-methacrylate, t-butyl methacrylate, 2-ethylbutyl methacrylate, methylcyclohexyl methacrylate, cinnamyl methacrylate, crotyl methacrylate, cyclohexyl methacrylate, cyclopentyl methacrylate, 2-ethoxyethyl methacrylate, isobornyl methacrylate, etc., as well as combinations thereof. In one particular embodiment, for example, the epoxy-functionalized component may include an epoxy-functional (meth) acrylic monomeric component, α-olefin monomeric component, and non-epoxy functional (meth) acrylic monomeric component.

The relative portion of the monomeric component (s) may be selected to achieve a balance between epoxy-reactivity and melt flow rate. More particularly, high epoxy monomer contents can result in good reactivity, such as with a matrix polymer, but too high of a content may reduce the melt flow rate to such an extent that the epoxy-functionalized component adversely impacts the melt strength of the polymer blend. Thus, in most embodiments, the epoxy-functional (meth) acrylic monomer (s) constitute from about 1 wt. %to about 20 wt. %, in some embodiments from about 2 wt. %to about 15 wt. %, and in some embodiments, from about 3 wt. %to about 10 wt. %of the epoxy-functionalized component. The α-olefin monomer (s) may likewise constitute from about 55 wt. %to about 95 wt. %, in some embodiments from about 60 wt.%to about 90 wt. %, and in some embodiments, from about 65 wt. %to about 85 wt. %of the epoxy-functionalized component. When employed, other monomeric components (e.g., non-epoxy functional (meth) acrylic monomers) may constitute from about 5 wt. %to about 35 wt. %, in some embodiments from about 8 wt. %to about 30 wt. %, and in some embodiments, from about 10 wt. %to about 25 wt. %of the epoxy-functionalized component. The result melt flow rate may, in some cases, be from about 1 to about 30 grams per 10 minutes ( “g/10 min” ) , in some embodiments from about 2 to about 20 g/10 min, and in some embodiments, from about 3 to about 15 g/10 min, as determined in accordance with ASTM D1238-13 at a load of 2.16 kg and temperature of 190℃.

The epoxy-functionalized component may, in some embodiments, be produced from the selected monomers via copolymerization processes, grafting process, or both. For example, in some embodiments, the epoxy-functional monomer is grafted to an olefinic monomer (e.g., glycidyl methacrylate grafted to a polyethylene, such as a high density polyethylene, to form GMA-g-PE) . In another embodiment, one example of a suitable epoxy-functionalized copolymer that may be used in the present invention is commercially available from Arkema under the name

AX8840.

AX8840, for instance, has a melt flow rate of 5 g/10 min and has a glycidyl methacrylate monomer content of 8 wt. %.Another suitable copolymer is commercially available from DuPont under the name

PTW, which is a terpolymer of ethylene, butyl acrylate, and glycidyl methacrylate and has a melt flow rate of 12 g/10 min and a glycidyl methacrylate monomer content of 4 wt. %to 5 wt. %.

In some embodiments, the epoxy-functionalized component may be present in an amount greater than about 0.1 wt. %, such as greater than about 1 wt. %, such as greater than about 2 wt. %, such as greater than about 3 wt. %, such as greater than about 4 wt. %, by weight of the polymer composition. In some examples, the component is present in an amount less than about 20 wt. %, such as less than about 15 wt. %, such as less than about 10 wt. %, such as less than about 8 wt. %.

A fibrous filler (e.g., inorganic fibers or beads) may be included in some embodiments of the polymer composition, such as to provide strength or a complementary dielectric effect. The inorganic fibers may generally have a high degree of tensile strength relative to their mass. For example, the ultimate tensile strength of the fibers (determined in accordance with ASTM D2101) may, in some cases, be from about 1,000 to about 15,000 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. The high strength fibers may be formed from materials that are also electrically insulative in nature, such as glass, ceramics (e.g., alumina or silica) , etc., as well as mixtures thereof. Glass fibers are particularly suitable, such as E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass, etc., and mixtures thereof. In one embodiment, the fibers can have a dielectric constant of less than about 6, such as less than about 5.5, such as less than about 5, such as less than about 4.8 and generally greater than about 1, such as greater than about 2 when measured at a frequency of 1 GHz.

The fibers may also have a relatively high length. For example, the fibers may have a volume average length of from about 1 to about 400 micrometers, in some embodiments from about 80 to about 250 micrometers, in some embodiments from about 100 to about 200 micrometers, and in some embodiments, from about 110 to about 180 micrometers. The fibers may also have a narrow length distribution. That is, at least about 70%by volume of the fibers, in some embodiments at least about 80%by volume of the fibers, and in some embodiments, at least about 90%by volume of the fibers have a length within the range of from about 1 to about 400 micrometers, in some embodiments from about 80 to about 250 micrometers, in some embodiments from about 100 to about 200 micrometers, and in some embodiments, from about 110 to about 180 micrometers. In addition to possessing the length characteristics noted above, the fibers may also have a relatively high aspect ratio (average length divided by nominal diameter) to help improve the mechanical properties of the resulting polymer composition. For example, the fibers may have an aspect ratio of from about 2 to about 50, in some embodiments from about 4 to about 40, and in some embodiments, from about 5 to about 20 are particularly beneficial. The fibers may, for example, have a nominal diameter of about 5 to about 35 micrometers, and in some embodiments, from about 8 to about 30 micrometers.

These fibers may be in modified or unmodified form, e.g. provided with a sizing, or chemically treated, in order to improve adhesion to the plastic. In some examples, glass fibers are provided with a sizing to protect the glass fiber, to smooth the fiber but also to improve the adhesion between the fiber and a matrix material. A sizing usually comprises silanes, film forming agents, lubricants, wetting agents, adhesive agents optionally antistatic agents and plasticizers, emulsifiers and optionally further additives. Specific examples of silanes are aminosilanes, e.g. 3-trimethoxysilylpropylamine, N- (2-aminoethyl) -3-aminopropyltrimethoxy-silane, N- (3-trimethoxysilanylpropyl) ethane-1, 2-diamine, 3- (2-aminoethyl-amino) propyltrimethoxysilane, N- [3- (trimethoxysilyl) propyl] -1, 2-ethane-diamine.

The fibers may be present, in some embodiments, in an amount of at least about 1 wt. %, such as greater than about 5 wt. %, such as greater than about 10 wt. %, such as greater than about 20 wt. %. In some embodiments, the fibers are present in an amount lower than about 40 wt. %, such as lower than about 30 wt. %, such as lower than about 20 wt. %.

Still other additives that can be included in the polymer composition can encompass, without limitation, lubricants, nucleating agents, coupling agents, antimicrobials, pigments or other colorants, impact modifiers, antioxidants, stabilizers, surfactants, flow promoters, solid solvents, waxes, flame retardants, anti-drip additives, additional polymers, and other materials added to enhance properties and processability. Such optional materials may be employed in the thermoplastic composition in conventional amounts and according to conventional processing techniques.

For example, the composition may include a nucleating agent in an amount from about 0.1 to about 5 parts, in some embodiments from about 0.2 parts to about 3 parts, and in some embodiments, from about 0.3 to about 2 parts by weight per 100 parts by weight of the polymer composition. For example, the nucleating agent may constitute between about 0.001%and 0.5%, from about from about 0.01 wt. %to about 5 wt. %, in some embodiments from about 0.05 wt. %to about 2 wt. %, and in some embodiments, from about 0.1 wt. %to about 1 wt. %of the polymer composition. Suitable nucleating agents may include, for instance, a salt (e.g., sodium salt) of a dicarboxylic acid, such as sodium terephthalates, sodium naphthalene dicarboxylates, and sodium isophthalates. Suitable nucleating agents also include a salt (e.g., sodium salt) of a C ₁₀ to C ₃₆ monofunctional organic acid, and in some embodiments, C ₃₀ to C ₃₆ monofunctional organic acid, such as sodium stearate, sodium behenate, sodium erucate, sodium palmitate, sodium montanate, or combinations thereof. An example of such a nucleating agent is a sodium salt of montanic acid, commercially available under the tradename Licomont ^TM NaV101 from Clariant.

Lubricants may also be employed, such as polyolefin waxes (e.g., polyethylene wax) , amide waxes, fatty acid ester waxes, etc. Such waxes may, in some cases, constitute from about 0.1 to about 20 parts, in some embodiments from about 0.4 to about 10 parts, and in some embodiments, from about 0.5 to about 5 parts per 100 parts of the polymer composition. Fatty acid ester waxes may, for instance, be obtained by oxidative bleaching of a crude natural wax and subsequent esterification of the fatty acids 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 multifunctional (e.g., 2 to 4 hydroxyl groups) , a carbon atom number of 2 to 8 is particularly desired. Particularly suitable multifunctional alcohols may include dihydric alcohol (e.g., ethylene glycol, propylene glycol, butylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 6-hexanediol and 1, 4-cyclohexanediol) , trihydric alcohol (e.g., glycerol and trimethylolpropane) , tetrahydric alcohols (e.g., pentaerythritol and erythritol) , and so forth. Aromatic alcohols may also be suitable, 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 mesitylene glycerol. Particularly suitable fatty acid esters for use in the present invention are derived from montanic waxes.

OP (Clariant) , for instance, contains montanic acids partially esterified with butylene glycol and montanic acids partially saponified with calcium hydroxide. Thus,

OP contains a mixture of montanic acid esters and calcium montanate. Other montanic acid esters that may be employed include

E,

OP, and

WE 4 (all from Clariant) , for instance, are montanic esters obtained as secondary products from the oxidative refining of raw montan wax.

E and

WE 4 contain montanic acids esterified with ethylene glycol or glycerine.

Yet another suitable lubricant may be a siloxane polymer that improves internal lubrication and that also helps to bolster the wear and friction properties of the composition encountering another surface. Such siloxane polymers may, in some embodiments, constitute from about 0.2 to about 20 parts, in some embodiments from about 0.5 to about 10 parts, and in some embodiments, from about 0.8 to about 5 parts per 100 parts of the polymer composition. Any of a variety of siloxane polymers may generally be employed. The siloxane polymer may, for instance, encompass any polymer, co-polymer or oligomer that includes siloxane units in the backbone having the formula:

R _r Si O _(4-r/2)

wherein R is independently hydrogen or substituted or unsubstituted hydrocarbon radicals, and r is 0, 1, 2, or 3.

Some examples of suitable radicals R include, for instance, alkyl, aryl, alkylaryl, alkenyl or alkynyl, or cycloalkyl groups, optionally substituted, and which may be interrupted by heteroatoms, i.e., may contain heteroatom (s) in the carbon chains or rings. Suitable alkyl radicals, may include, for instance, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-pentyl radicals, hexyl radicals (e.g., n-hexyl) , heptyl radicals (e.g., n-heptyl) , octyl radicals (e.g., n-octyl) , isooctyl radicals (e.g., 2, 2, 4-trimethylpentyl radical) , nonyl radicals (e.g., n-nonyl) , decyl radicals (e.g., n-decyl) , dodecyl radicals (e.g., n-dodecyl) , octadecyl radicals (e.g., n-octadecyl) , and so forth. Likewise, suitable cycloalkyl radicals may include cyclopentyl, cyclohexyl cycloheptyl radicals, methylcyclohexyl radicals, and so forth; suitable aryl radicals may include phenyl, biphenyl, naphthyl, anthryl, and phenanthryl radicals; suitable alkylaryl radicals may include o-, m-or p-tolyl radicals, xylyl radicals, ethylphenyl radicals, and so forth; and suitable alkenyl or alkynyl radicals may include vinyl, 1-propenyl, 1-butenyl , 1-pentenyl, 5-hexenyl, butadienyl, hexadienyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, ethynyl, propargyl 1-propynyl, and so forth. Examples of substituted hydrocarbon radicals are halogenated alkyl radicals (e.g., 3-chloropropyl, 3, 3, 3-trifluoropropyl, and perfluorohexylethyl) and halogenated aryl radicals (e.g., p-chlorophenyl and p-chlorobenzyl) . In one particular embodiment, the siloxane polymer includes alkyl radicals (e.g., methyl radicals) bonded to at least 70 mol %of the Si atoms and optionally vinyl and/or phenyl radicals bonded to from 0.001 to 30 mol %of the Si atoms. The siloxane polymer is also preferably composed predominantly of diorganosiloxane units. The end groups of the polyorganosiloxanes may be trialkylsiloxy groups, in particular the trimethylsiloxy radical or the dimethylvinylsiloxy radical. However, it is also possible for one or more of these alkyl groups to have been replaced by hydroxy groups or alkoxy groups, such as methoxy or ethoxy radicals. Particularly suitable examples of the siloxane polymer include, for instance, dimethylpolysiloxane, phenylmethylpolysiloxane, vinylmethylpolysiloxane, and trifluoropropylpolysiloxane.

The siloxane polymer may also include a reactive functionality on at least a portion of the siloxane monomer units of the polymer, such as one or more of vinyl groups, hydroxyl groups, hydrides, isocyanate groups, epoxy groups, acid groups, halogen atoms, alkoxy groups (e.g., methoxy, ethoxy and propoxy) , acyloxy groups (e.g., acetoxy and octanoyloxy) , ketoximate groups (e.g., dimethylketoxime, methylketoxime and methylethylketoxime) , amino groups (e.g., dimethylamino, diethylamino and butylamino) , amido groups (e.g., N-methylacetamide and N-ethylacetamide) , acid amido groups, amino-oxy groups, mercapto groups, alkenyloxy groups (e.g., vinyloxy, isopropenyloxy, and 1-ethyl-2-methylvinyloxy) , alkoxyalkoxy groups (e.g., methoxyethoxy, ethoxyethoxy and methoxypropoxy) , aminoxy groups (e.g., dimethylaminoxy and diethylaminoxy) , mercapto groups, etc.

Regardless of its particular structure, the siloxane polymer may optionally have a relatively high molecular weight, which reduces the likelihood that it migrates or diffuses to the surface of the polymer composition and thus further minimizes the likelihood of phase separation. For instance, the siloxane polymer may have a weight average molecular weight of about 100,000 grams per mole or more, in some embodiments about 200,000 grams per mole or more, and in some embodiments, from about 500,000 grams per mole to about 2,000,000 grams per mole. The siloxane polymer may also have a relative high kinematic viscosity, such as about 10,000 centistokes or more, in some embodiments about 30,000 centistokes or more, and in some embodiments, from about 50,000 to about 500,000 centistokes.

If desired, silica particles (e.g., fumed silica) may also be employed in combination with the siloxane polymer to help improve its ability to be dispersed within the composition. Such silica particles may, for instance, have a particle size of from about 5 nanometers to about 50 nanometers, a surface area of from about 50 square meters per gram (m ²/g) to about 600 m ²/g, and/or a density of from about 160 kilogram per cubic meter (kg/m ³) to about 190 kg/m ³. When employed, the silica particles may optionally constitute from about 1 to about 100 parts, and in some some embodiments, from about 20 to about 60 parts by weight based on 100 parts by weight of the siloxane polymer. In one embodiment, the silica particles can be combined with the siloxane polymer prior to addition of this mixture to the polymer composition. For instance a mixture including an ultrahigh molecular weight polydimethylsiloxane and fumed silica can be incorporated in the polymer composition. Such a pre-formed mixture is available as

Pellet S from Wacker Chemie, AG.

Sterically hindered phenolic antioxidant (s) may be employed in the composition. Examples of such phenolic antioxidants include, for instance, calcium bis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate) (

1425) ; terephthalic acid, 1, 4-dithio-, S, S-bis (4-tert-butyl-3-hydroxy-2, 6-dimethylbenzyl) ester (

1729) ; triethylene glycol bis (3-tert-butyl-4-hydroxy-5-methylhydrocinnamate) ; hexamethylene bis (3, 5-di-tert-butyl-4-hydroxyhydrocinnamate (

259) ; 1, 2-bis (3, 5, di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazide (

1024) ; 4, 4′-di-tert-octyldiphenamine (

438R) ; phosphonic acid, (3, 5-di-tert-butyl-4-hydroxybenzyl) -, dioctadecyl ester (

1093) ; 1, 3, 5-trimethyl-2, 4, 6-tris (3′, 5′-di-tert-butyl-4′hydroxybenzyl) benzene (

1330) ; 2, 4-bis (octylthio) -6- (4-hydroxy-3, 5-di-tert-butylanilino) -1, 3, 5-triazine (

565) ; isooctyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (

1135) ; octadecyl 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (

1076) ; 3, 7-bis (1, 1, 3, 3- tetramethylbutyl) -10H-phenothiazine (

LO 3) ; 2, 2′-methylenebis (4-methyl-6-tert-butylphenol) monoacrylate (

3052) ; 2-tert-butyl-6- [1- (3-tert-butyl-2-hydroxy-5-methylphenyl) ethyl] -4-methylphenyl acrylate (

TM 4039) ; 2- [1- (2-hydroxy-3, 5-di-tert-pentylphenyl) ethyl] -4, 6-di-tert-pentylphenyl acrylate (

GS) ; 1, 3-dihydro-2H-Benzimidazole (

MB) ; 2-methyl-4, 6-bis [ (octylthio) methyl] phenol (

1520) ; N, N′-trimethylenebis- [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide (

1019) ; 4-n-octadecyloxy-2, 6-diphenylphenol (

1063) ; 2, 2′-ethylidenebis [4, 6-di-tert-butylphenol] (

129) ; N N′-hexamethylenebis (3, 5-di-tert-butyl-4-hydroxyhydrocinnamamide) (

1098) ; diethyl (3, 5-di-tert-butyl-4-hydroxybenxyl) phosphonate (

1222) ; 4, 4′-di-tert-octyldiphenylamine (

5057) ; N-phenyl-1-napthalenamine (

L 05) ; tris [2-tert-butyl-4- (3-ter-butyl-4-hydroxy-6-methylphenylthio) -5-methyl phenyl] phosphite (

OSP 1) ; zinc dinonyidithiocarbamate (

VP-ZNCS 1) ; 3, 9-bis [1, 1-diimethyl-2- [ (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2, 4, 8, 10-tetraoxaspiro [5.5] undecane (

AG80) ; pentaerythrityl tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate] (

1010) ; ethylene-bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) -propionate (

245) ; 3, 5-di-tert-butyl-4-hydroxytoluene (Lowinox BHT, Chemtura) and so forth.

Some examples of suitable sterically hindered phenolic antioxidants for use in the present composition are triazine antioxidants having the following general formula:

wherein, each R is independently a phenolic group, which may be attached to the triazine ring via a C ₁ to C ₅ alkyl or an ester substituent. Preferably, each R is one of the following formula (I) - (III) :

Commercially available examples of such triazine-based antioxidants may be obtained from American Cyanamid under the designation

1790 (wherein each R group is represented by the Formula III) and from Ciba Specialty Chemicals under the designations

3114 (wherein each R group is represented by the Formula I) and

3125 (wherein each R group is represented by the Formula II) .

Sterically hindered phenolic antioxidants may constitute from about 0.01 wt. %to about 3 wt. %, in some embodiments from about 0.05 wt. %to about 1 wt. %, and in some embodiments, from about 0.05 wt. %to about 0.1 wt. %of the entire stabilized polymer composition. In one embodiment, for instance, the antioxidant comprises pentaerythrityl tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

Hindered amine light stabilizers ( “HALS” ) may be employed in the composition to inhibit degradation of the polyester composition and thus extend its durability. Suitable HALS compounds may be derived from a substituted piperidine, such as alkyl-substituted piperidyl, piperidinyl, piperazinone, alkoxypiperidinyl compounds, and so forth. For example, the hindered amine may be derived from a 2, 2, 6, 6-tetraalkylpiperidinyl. Regardless of the compound from which it is derived, the hindered amine may, in some cases, be an oligomeric or polymeric compound having a number average molecular weight of about 1,000 or more, in some embodiments from about 1000 to about 20,000, in some embodiments from about 1500 to about 15,000, and in some embodiments, from about 2000 to about 5000. Such compounds may contain at least one 2, 2, 6, 6-tetraalkylpiperidinyl group (e.g., 1 to 4) per polymer repeating unit.

Without intending to be limited by theory, it is believed that high molecular weight hindered amines are relatively thermostable and thus able to inhibit light degradation even after being subjected to extrusion conditions. One particularly suitable high molecular weight hindered amine has the following general structure:

wherein, p is 4 to 30, in some embodiments 4 to 20, and in some embodiments 4 to 10. This oligomeric compound is commercially available from Clariant under the designation

N30 and has a number average molecular weight of 1200.

Another suitable high molecular weight hindered amine has the following structure:

wherein, n is from 1 to 4 and R ₃₀ is independently hydrogen or CH ₃. Such oligomeric compounds are commercially available from Adeka Palmarole SAS (joint venture between Adeka Corp. and Palmarole Group) under the designation ADK

LA-63 (R ₃₀ is CH ₃) and ADK

LA-68 (R ₃₀ is hydrogen) .

Other examples of suitable high molecular weight hindered amines include, for instance, an oligomer of N- (2-hydroxyethyl) -2, 2, 6, 6-tetramethyl-4-piperidinol and succinic acid (

622 from Ciba Specialty Chemicals, MW=4000) ; oligomer of cyanuric acid and N, N-di (2, 2, 6, 6-tetramethyl-4-piperidyl) -hexamethylene diamine; poly ( (6-morpholine-S-triazine-2, 4-diyl) (2, 2, 6, 6-tetramethyl-4-piperidinyl) -iminohexamethylene- (2, 2, 6, 6-tetramethyl-4-piperidinyl) -imino) (

UV 3346 from Cytec, MW=1600) ; polymethylpropyl-3-oxy- [4 (2, 2, 6, 6-tetramethyl) -piperidinylysiloxane (

299 from Great Lakes Chemical, MW=1100 to 2500) ; copolymer of α-methylstyrene-N- (2, 2, 6, 6-tetramethyl-4- piperidinyl) maleimide and N-stearyl maleimide; 2, 4, 8, 10-tetraoxaspiro [5.5] undecane-3, 9-diethanol tetramethyl-polymer with 1, 2, 3, 4-butanetetracarboxylic acid; and so forth. Still other suitable high molecular weight hindered amines are described in U.S. Pat. Nos. 5,679,733 to Malik, et al. and 6,414,155 to Sassi, et al., which are incorporated herein in their entirety by reference thereto for all purposes.

In addition to the high molecular hindered amines, low molecular weight hindered amines may also be employed in the composition. Such hindered amines are generally monomeric in nature and have a molecular weight of about 1000 or less, in some embodiments from about 155 to about 800, and in some embodiments, from about 300 to about 800.

Specific examples of such low molecular weight hindered amines may include, for instance, bis- (2, 2, 6, 6-tetramethyl-4-piperidyl) sebacate (

770 from Ciba Specialty Chemicals, MW=481) ; bis- (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl) - (3, 5-ditert. butyl-4-hydroxybenzyl) butyl-propane dioate; bis- (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl) sebacate; 8-acetyl-3-dodecyl-7, 7, 9, 9-tetramethyl-1, 3, 8-triazaspiro- (4, 5) -decane-2, 4-dione, butanedioic acid-bis- (2, 2, 6, 6-tetramethyl-4-piperidinyl) ester; tetrakis- (2, 2, 6, 6-tetramethyl-4-piperidyl) -1, 2, 3, 4-butane tetracarboxylate; 7-oxa-3, 20-diazadispiro (5.1.11.2) heneicosan-20-propanoic acid, 2, 2, 4, 4-tetramethyl-21-oxo, dodecyl ester; N- (2, 2, 6, 6-tetramethyl-4-piperidinyl) -N′-amino-oxamide; o-t-amyl-o- (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl) -monoperoxi-carbonate; β-alanine, N- (2, 2, 6, 6-tetramethyl-4-piperidinyl) , dodecylester; ethanediamide, N- (1-acetyl-2, 2, 6, 6-tetramethylpiperidinyl) -N′-dodecyl; 3-dodecyl-1- (2, 2, 6, 6-tetramethyl-4-piperidinyl) -pyrrolidin-2, 5-dione; 3-dodecyl-1- (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl) -pyrrolidin-2, 5-dione; 3-dodecyl-1- (1-acetyl, 2, 2, 6, 6-tetramethyl-4-piperidinyl) -pyrrolidin-2, 5-dione, (

3058 from Clariant, MW=448.7) ; 4-benzoyloxy-2, 2, 6, 6-tetramethylpiperidine; 1- [2- (3, 5-di-tert-butyl-4-hydroxyphenylpropionyloxy) ethyl] -4- (3, 5-di-tert-butyl-4-hydroxylphenyl propionyloxy) -2, 2, 6, 6-tetramethyl-piperidine; 2-methyl-2- (2″, 2″, 6″, 6″-tetramethyl-4″-piperidinylamino) -N- (2′, 2′, 6′, 6′-tetra-methyl-4′-piperidinyl) propionylamide; 1, 2-bis- (3, 3, 5, 5-tetramethyl-2-oxo-piperazinyl) ethane; 4-oleoyloxy-2, 2, 6, 6-tetramethylpiperidine; and combinations thereof. Other suitable low molecular weight hindered amines are described in U.S. Pat. Nos. 5,679,733 to Malik, et al.

The hindered amines may be employed singularly or in combination in any amount to achieve the desired properties, but may, in some cases, constitute from about 0.01 wt. %to about 4 wt. %of the polymer composition.

UV absorbers, such as benzotriazoles or benzopheones, may be employed in the composition to absorb ultraviolet light energy. Suitable benzotriazoles may include, for instance, 2- (2-hydroxyphenyl) benzotriazoles, such as 2- (2-hydroxy-5-methylphenyl) benzotriazole; 2- (2- hydroxy-5-tert-octylphenyl) benzotriazole (

UV 5411 from Cytec) ; 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzo-triazole; 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole; 2- (2-hydroxy-3, 5-dicumylphenyl) benzotriazole; 2, 2′-methylenebis (4-tert-octyl-6-benzo-triazolylphenol) ; polyethylene glycol ester of 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole; 2- [2-hydroxy-3- (2-acryloyloxyethyl) -5-methylphenyl] -benzotriazole; 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] benzotriazole; 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-octylphenyl] benzotriazole; 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] -5-chlorobenzotriazole; 2- [2-hydroxy-5- (2-methacryloyloxyethyl) phenyl] benzotriazole; 2- [2-hydroxy-3-tert-butyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole; 2- [2-hydroxy-3-tert-amyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole; 2- [2-hydroxy-3-tert-butyl-5- (3-methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole; 2- [2-hydroxy-4- (2-methacryloyloxymethyl) phenyl] benzotriazole; 2- [2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropyl) phenyl] benzotriazole; 2- [2-hydroxy-4- (3-methacryloyloxypropyl) phenyl] benzotriazole; and combinations thereof.

Exemplary benzophenone light stabilizers may likewise include 2-hydroxy-4-dodecyloxybenzophenone; 2, 4-dihydroxybenzophenone; 2- (4-benzoyl-3-hydroxyphenoxy) ethyl acrylate (

UV 209 from Cytec) ; 2-hydroxy-4-n-octyloxy) benzophenone (

531 from Cytec) ; 2, 2′-dihydroxy-4- (octyloxy) benzophenone (

UV 314 from Cytec) ; hexadecyl-3, 5-bis-tert-butyl-4-hydroxybenzoate (

UV 2908 from Cytec) ; 2, 2′-thiobis (4-tert-octylphenolato) -n-butylamine nickel (II) (

UV 1084 from Cytec) ; 3, 5-di-tert-butyl-4-hydroxybenzoic acid, (2, 4-di-tert-butylphenyl) ester (

712 from Cytec) ; 4, 4′-dimethoxy-2, 2′-dihydroxybenzophenone (

UV 12 from Cytec) ; and combinations thereof.

When employed, UV absorbers may constitute from about 0.01 wt. %to about 4 wt. %of the entire polymer composition.

In one embodiment, the polymer composition may contain a blend of stabilizers that produce ultraviolet resistance and color stability. The combination of stabilizers may allow for products to be produced that have bright and fluorescent colors. In addition, bright colored products can be produced without experiencing significant color fading over time. In one embodiment, for instance, the polymer composition may contain a combination of a benzotriazole light stabilizer and a hindered amine light stabilizer, such as an oligomeric hindered amine.

Various other stabilizers may also be present in the composition. For instance, in one embodiment, the composition may contain a phosphite, such as a diphosphite. For instance, in one embodiment, the phosphite compound may comprise distearyl pentaerythritol diphosphite. The phosphite compound may also comprise bis (2, 4-ditert-butylphenyl) pentaerythritol diphosphite.

Organophosphorus compounds may be employed in the composition that serve as secondary antioxidants to decompose peroxides and hydroperoxides into stable, non-radical products. Trivalent organophosphorous compounds (e.g., phosphites or phosphonites) are particularly useful in the stabilizing system of the present invention. Monophosphite compounds (i.e., only one phosphorus atom per molecule) may be employed in certain embodiments of the present invention. Preferred monophosphites are aryl monophosphites contain C ₁ to C ₁₀ alkyl substituents on at least one of the aryloxide groups. These substituents may be linear (as in the case of nonyl substituents) or branched (such as isopropyl or tertiary butyl substituents) . Non-limiting examples of suitable aryl monophosphites (or monophosphonites) may include triphenyl phosphite; diphenyl alkyl phosphites; phenyl dialkyl phosphites; tris (nonylphenyl) phosphite (Weston ^TM 399, available from GE Specialty Chemicals) ; tris (2, 4-di-tert-butylphenyl) phosphite (

168, available from Ciba Specialty Chemicals Corp. ) ; bis (2, 4-di-tert-butyl-6-methylphenyl) ethyl phosphite (

38, available from Ciba Specialty Chemicals Corp. ) ; and 2, 2′, 2″-nitrilo [triethyltris (3, 3′5, 5′-tetra-tert-butyl-1, 1′-biphenyl-2, 2′-diyl) phosphate (

12, available from Ciba Specialty Chemicals Corp. ) . Aryl diphosphites or diphosphonites (i.e., contains at least two phosphorus atoms per phosphite molecule may also be employed in the stabilizing system and may include, for instance, distearyl pentaerythritol diphosphite, diisodecyl pentaerythritol diphosphite, bis (2, 4 di-tert-butylphenyl) pentaerythritol diphosphite (Ultranox ^TM 626, available from GE Specialty Chemicals) ; bis (2, 6-di-tert-butyl-4-methylpenyl) pentaerythritol diphosphite; bisisodecyloxypentaerythritol diphosphite, bis (2, 4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis (2, 4, 6-tri-tert-butylphenyl) pentaerythritol diphosphite, tetrakis (2, 4-di-tert-butylphenyl) 4, 4′-biphenylene-diphosphonite (Sandostab ^TM P-EPQ, available from Clariant) and bis (2, 4-dicumylphenyl) pentaerythritol diphosphite (

S-9228) .

Organophosphorous compounds may constitute from about 0.01 wt. %to about 2 wt. %, in some embodiments from about 0.05 wt. %to about 1 wt. %, and in some embodiments, from about 0.1 wt. %to about 0.5 wt. %of the polymer composition.

In addition to those mentioned above, secondary amines may also be employed in the composition. The secondary amines may be aromatic in nature, such as N-phenyl naphthylamines (e.g.,

PAN from Uniroyal Chemical) ; diphenylamines, such as 4, 4′-bis (dimethylbenzyl) -diphenylamine (e.g.,

445 from Uniroyal Chemical) ; p-phenylenediamines (e.g.,

300 from Goodyear) ; quinolones, and so forth. Particularly suitable secondary amines are oligomeric or polymeric amines, such as homo-or copolymerized polyamides. Examples of such polyamides may include nylon 3 (poly-β-alanine) , nylon 6, nylon 10, nylon 11, nylon 12, nylon 6/6, nylon 6/9, nylon 6/10, nylon 6/11, nylon 6/12, polyesteramide, polyamideimide, polyacrylamide, and so forth. In one particular embodiment, the amine is a polyamide terpolymer having a melting point in the range from 120℃. to 220℃. Suitable terpolymers may be based on the nylons selected from the group consisting of nylon 6, nylon 6/6, nylon 6/9, nylon 6/10 and nylon 6/12, and may include nylon 6-66-69; nylon 6-66-610 and nylon 6-66-612. One example of such a nylon terpolymer is a terpolymer of nylon 6-66-610 and is commercially available from Du Pont de Nemours under the designation

8063R. Still other suitable amine compounds are described in U.S. Patent Application Publication No. 2003/0060529 to Ho, et al., which is incorporated herein in its entirety by reference thereto for all purposes.

Secondary amines may constitute from about 0.01 wt. %to about 2 wt. %, of the entire polymer composition.

If desired, other known stabilizers may also be incorporated into the composition, such as metal deactivators, acid stabilizers, other light stabilizers (e.g., benzophenones) or antioxidants, etc. Acid stabilizers, for instance, may help neutralize the acidic catalysts or other components present in the polymers. Suitable acid stabilizers may include zinc oxide, calcium lactate, natural and synthetic hydrotalcites, natural and synthetic hydrocalumites, and alkali metal salts and alkaline earth metal salts of higher fatty acids, such as calcium stearate, zinc stearate, magnesium stearate, sodium stearate, sodium ricinoleate and potassium palmitate. When employed, such acid stabilizers may, in some cases, constitute about 1.5 wt. %or less, in some embodiments, about 1 wt. %or less, and in some embodiments, from about 0.01 wt. %to about 0.5 wt. %of the polymer composition.

Each stabilizer above may be present in an amount from about 0.01%to about 3 wt. %, such as from about 0.05%to about 0.5 wt. %. In a preferred embodiment, the composition contains both a heat stabilizer and an antioxidant. For example, the heat stabilizer may comprise a sterically hindered phenolic compound and the antioxidant may comprise a diphosphite.

The various components of the polymer composition as described herein may be combined in any suitable manner, such as melt processed or blended together. For example, the components may be supplied separately or in combination to an extruder that includes at least one screw rotatably mounted and received within a barrel (e.g., cylindrical barrel) and may define a feed section and a melting section located downstream from the feed section along the length of the screw. Sometimes, it is desired to minimize the number of distributive and/or dispersive mixing elements that are employed within the mixing and/or melting sections of the extruder. For example, the extent to which the length of any fiber components is degraded during extrusion can be minimized, such as by adding the fibers at a location downstream from the point at which other polymeric components are supplied (e.g., hopper) . The epoxy-functionalized component, if used, may also be added to the extruder at a location downstream from the point at which other polymeric components are supplied. One or more of the sections of the extruder may be heated, such as within a temperature range of from about 200℃ to about 450℃., in some embodiments, from about 220℃ to about 350℃, and in some embodiments, from about 250℃ to about 350℃ to form the composition. The speed of the screw may be selected to achieve the desired residence time, shear rate, melt processing temperature, etc. For example, the screw speed may range from about 50 to about 800 revolutions per minute ( “rpm” ) , in some embodiments from about 70 to about 150 rpm, and in some embodiments, from about 80 to about 120 rpm. The apparent shear rate during melt blending may also range from about 100 s ^-1 to about 10,000 s ^-1, in some embodiments from about 500 s ^-1 to about 5000 s ^-1, and in some embodiments, from about 800 s ^-1 to about 1200 s ^-1. The apparent shear rate is equal to 4Q/πR ³, where Q is the volumetric flow rate ( “m ³/s” ) of the polymer melt and R is the radius ( “m” ) of the capillary (e.g., extruder die) through which the melted polymer flows.

Polymer compositions made in accordance with the present disclosure can be used in numerous and diverse applications. For instance, the polymer composition can be bonded with metals through injection molding or can be molded into various articles. The molded articles can be used in electrical components. For example, the polymer composition of the present disclosure can be used to form covers for electrical components, such as mobile phones, covers or coatings for computer antennas, projector covers, connectors, auto parts, and the like.

In one embodiment, for instance, the polymer composition may be used to produce coatings for wires. As used herein, a wire is referred to as any multi-layer article that has a linear configuration. The term wire, for instance, includes cables and all flexible threads or rods that include a core covered by a coating.

Referring to FIG. 1, for instance, one embodiment of a wire 10 in accordance with the present disclosure is shown. As illustrated, the wire 10 includes a core 12 that can be made from one or more metal elements. In the embodiment illustrated, for instance, the core 12 is made from multiple threads or filaments. The core 12 is surrounded by a coating or sheath 14 made in accordance with the present disclosure. In particular, the flame resistant, polymer composition containing the thermoplastic elastomer in combination with the α-olefin and vinyl acetate copolymer can be used to produce the sheath in forming the wire 10.

In an alternative embodiment, the polymer composition of the present disclosure can be used to produce protective covers for electronics. For instance, FIG. 2 illustrates a protective cover 40 for a mobile phone.

In still another embodiment, the polymer composition of the present disclosure can be used to produce a connector 50 as shown in FIG. 3. The connector 50 includes a first connector 52, such as a USB port, and a second connector 54 that are in electrical communication with each other by a cable 56. In accordance with the present disclosure, the polymer composition may be used to produce the sheath 58 that is part of the cable 56. In addition, the polymer composition may be used to produce a transition sleeve 60. The transition sleeve 60 is positioned around the cable 56 before entering each

connector

52 and 54. The polymer composition of the present disclosure is particularly well suited for producing the sleeves 60 because sleeves made from the polymer composition are very resistant to kinking.

Examples

The following examples were conducted in order to demonstrate some of the advantages and benefits of polymer compositions made according to the present disclosure. Samples were formulated according to Table 1.

Table 1: Sample Formulations

*D _k at 1 GHz ≈ 4.5

The ultrahigh molecular weight polyethylene particles had an average particle size (d50) of 145 microns using laser scattering. The average molecular weight of the ultrahigh molecular weight polyethylene was 5, 700,000 g/mol (Margolies’equation) . The ultrahigh molecular weight polyethylene had a density of 0.930 g/cm ³ and a bulk density of 0.45 g/cm ³. The ultrahigh molecular weight polyethylene had a melt flow rate at 190℃ and a load of 21.6 kg of less than 0.1 g/10 min and had a viscosity number of less than 3,000 ml/g.

A 32 mm twin-screw extruder (Steer) was used with the parameters as shown in Table 2. All ingredients except for the glass fiber were added into the throat feed zone; the glass fiber was added through a middle stream feed zone. Each sample was removed in the form of a strand from a die having a 3.2 mm diameter. The resulting samples were granulated after a water cooling step.

Table 2: Compounding of Sample Formulations

The granulates were pre-dried for 4 hours at 120 ℃ and then injection molded using a Fanuc Roboshot S2000i-100B injection molding machine with the parameters as shown in Table 3 to form test specimens from each sample composition.

Table 3: Injection Molding of Sample Formulations

Various properties of the test specimens molded from each sample composition were measured and are reported in Table 4.

Table 4: Test Results

These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged either in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.

Claims

A polymer composition having electrical insulating properties comprising:

a semi-crystalline aromatic thermoplastic polymer, the thermoplastic polymer being present in the composition in an amount of at least 40%by weight;

a polymeric filler comprising high density polyethylene particles, the polymer filler being present in the polymer composition sufficient to lower the dielectric constant of the thermoplastic polymer by more than 2%when tested at a frequency of 2.5 GHz; and

optionally glass fibers, the glass fibers being present in the composition in an amount from 0%to 35%by weight, the glass fibers having a dielectric constant at a frequency of 1 GHz of less than about 6.
A polymer composition as defined in claim 1, wherein the polymeric filler is present in the composition in an amount sufficient to lower the dissipation factor of the thermoplastic polymer by more than about 10%when tested at a frequency of 2.5 GHz.
A polymer composition as defined in any of the preceding claims, wherein the polymer composition has a dielectric constant of less than about 3 when measured at a frequency of 2.5 GHz.
A polymer composition as defined in any of the preceding claims, wherein the thermoplastic polymer comprises a polybutylene terephthalate.
A polymer composition as defined in any of claims 1-3, wherein the thermoplastic polymer comprises a polyarylene sulfide.
A polymer composition as defined in any of the preceding claims, wherein the polymer composition contains the glass fibers in an amount from about 5%to about 30%by weight.
A polymer composition as defined in any of the preceding claims, wherein the polymeric filler is present in the composition in an amount from about 8%to about 30%by weight.
A polymer composition as defined in any of the preceding claims, wherein the polymeric filler is present in the composition in an amount sufficient to decrease the density of the thermoplastic polymer by at least 4%.
A polymer composition as defined in any of the preceding claims, wherein the composition further contains an epoxy-functional polymer.
A polymer composition as defined in claim 9, wherein the epoxy-functional polymer is present in the composition in an amount from about 2%to about 10%by weight.
A polymer composition as defined in claim 9 or 10, wherein the epoxy-functional polymer comprises a polyethylene grafted with glycidyl methacrylate.
A polymer composition as defined in any of the preceding claims, wherein the polymer composition has a dissipated factor of less than about 0.01 when measured at a frequency of 2.5 GHz.
A polymer composition as defined in any of the preceding claims, wherein the polymer composition has a density of less than about 1.4 kg/m ³.
A polymer composition as defined in any of the preceding claims, wherein the thermoplastic polymer comprises a polybutylene terephthalate, the polybutylene terephthalate being present in the composition in an amount from about 45%to about 70%by weight, the polymer composition containing the glass fibers in an amount from about 15%by weight to about 25%by weight, the polymer composition further containing an epoxy-functional polymer in an amount from about 3%to about 8%by weight, and wherein the polymeric filler is present in the polymer composition in an amount from about 8%to about 25%by weight.
A polymer composition as defined in any of the preceding claims, wherein the high density polyethylene particles comprise ultrahigh molecular weight polyethylene particles.
A polymer composition as defined in any of the preceding claims, wherein the high density polyethylene particles have a D50 value of from about from about 10 μm to about 300 μm.
A polymer composition as defined in any of the preceding claims, wherein the high density polyethylene particles have a molecular weight of from about 1,000,000 g/mol to about 10,000,000 g/mol.
An article of manufacture comprising:

a metal substrate; and

a polymer composition bonded to the metal substrate, the polymer composition comprising the polymer composition as defined in any of the preceding claims.
A molded article made from the polymer composition as defined in any of claims 1-17.
A cable or wire comprising a coating made from the polymer composition defined in any of claims 1-17.
A case for an electronic device made from the polymer composition defined in any of claims 1-17.
An automotive part made from the polymer composition as defined in any of claims 1-17.