CN116648477A

CN116648477A - Fiber reinforced propylene polymer compositions

Info

Publication number: CN116648477A
Application number: CN202180085505.0A
Authority: CN
Inventors: 大卫·W·伊斯特普; 亚伦·H·约翰逊
Original assignee: Ticona LLC
Current assignee: Ticona LLC
Priority date: 2020-12-17
Filing date: 2021-12-07
Publication date: 2023-08-25

Abstract

A fiber reinforced polymer composition is provided comprising about 60wt.% to about 90wt.% of a polymer matrix comprising a propylene polymer and about 10wt.% to about 40wt.% of a plurality of long reinforcing fibers distributed within the polymer matrix. The polymer composition exhibits a dielectric constant of about 4 or less and a dissipation factor of about 0.01 or less at a frequency of 2 GHz. In addition, the polymer composition exhibits about 20kJ/m measured at a temperature of about 23℃according to ISO test No. 179-1:2010 ² Or greater notched impact strength of a simply supported beam, and a limiting oxygen of about 25 or greater as determined according to ISO 4589:2017An index.

Description

Fiber reinforced propylene polymer compositions

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional patent application Ser. No. 63/126,602, 12/17, 2020, 4/7, 2021, and 63/171,608, which are incorporated herein by reference in their entirety.

Background

Electronic modules typically contain electronic components (e.g., printed circuit boards, antenna elements, radio frequency devices, sensors, light sensing and/or transmitting elements (e.g., optical fibers), cameras, global positioning devices, etc.), which are housed within a housing structure to protect them from weather effects such as sunlight, wind, and moisture. Typically, such housings are formed of a material that allows electromagnetic signals (e.g., radio frequency signals or light) to pass through. While these materials are suitable in some applications, problems can occur in higher frequency ranges, such as those associated with LTE or 5G systems. In these applications, various attempts have been made to employ fiber reinforced materials to provide the necessary strength. Unfortunately, most conventional fiber reinforced materials exhibit relatively high dissipation factors (loss tangent) and dielectric constants at high frequencies, which result in unacceptable levels of electromagnetic signal loss. Furthermore, attempts to improve electrical loss properties can adversely affect the flame retardancy of the material, which is undesirable in most electrical applications. Accordingly, there is a need for improved materials for electronic modules.

Disclosure of Invention

According to one embodiment of the present invention, a fiber reinforced polymer composition is disclosed that includes from about 60wt.% to about 90wt.% of a polymer matrix comprising a propylene polymer and from about 10wt.% to about 40wt.% of a plurality of long reinforcing fibers distributed within the polymer matrix. The polymer composition exhibits a dielectric constant of about 4 or less and a dissipation factor of about 0.01 or less at a frequency of 2 GHz. In addition, the polymer composition exhibits about 20kJ/m measured at a temperature of about 23℃according to ISO test No. 179-1:2010 ² Or greater notched impact strength of a simply supported beam, about 25 or greater limits as determined according to ISO 4589:2017Oxygen index.

Other features and aspects of the present invention are set forth in more detail below.

Drawings

A full and enabling disclosure of the present invention, including the best mode thereof to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures wherein:

FIG. 1 is a schematic diagram of one embodiment of a system that may be used to form the polymer compositions of the present invention;

FIG. 2 is a cross-sectional view of an impregnation die that may be used with the system shown in FIG. 1;

FIG. 3 is an exploded perspective view of one embodiment of an electronic module that can employ the polymer composition of the present invention; and

fig. 4 depicts one embodiment of a 5G system that may employ the electronic module shown in fig. 3.

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 invention.

In general, the present invention relates to a fiber reinforced propylene polymer composition for use in various electronic devices and systems. The composition includes a polymer matrix comprising a propylene polymer and a plurality of long reinforcing fibers distributed within the polymer matrix. The inventors have found that by careful selection of the specific properties and concentrations of the components of the polymer composition, the resulting composition can exhibit a synergistic combination of good electrical properties (i.e., low dielectric constant and dissipation factor) with good mechanical properties and flame retardant properties. That is, the polymer composition may exhibit a low dielectric constant of about 4 or less, in some embodiments about 3.5 or less, in some embodiments about 0.1 to about 3.4, in some embodiments about 1 to about 3.3, in some embodiments about 1.5 to about 3.2, in some embodiments about 2 to about 3.1, and in some embodiments about 2.5 to about 3.1 at high frequencies (e.g., 2GHz or 10 GHz). The dissipation factor of the polymer composition (which is a measure of the rate of energy loss) can likewise be about 0.01 or less, in some embodiments about 0.009 or less, in some embodiments about 0.008 or less, in some embodiments about 0.007 or less, in some embodiments about 0.006 or less, and in some embodiments about 0.001 to about 0.005 at high frequencies (e.g., 2GHz or 10 GHz).

The polymer composition is also generally flame retardant. For example, the extent to which the composition can extinguish a fire ("form coke") can be expressed by its limiting oxygen index ("LOI"), which is the volume percent of oxygen required to support combustion. More specifically, the polymer composition may have an LOI of about 25 or greater, in some embodiments about 27 or greater, in some embodiments about 28 or greater, and in some embodiments about 30 to 100, when measured according to ISO 4589:2017 (technically equivalent to ASTM D2863-19). Flame retardancy may also be characterized according to the procedure of underwriter laboratory bulletin 94 entitled "flammability test of Plastic Material, UL 94". Depending on the extinguishing time (total flame time of a set of 5 samples) and the anti-drip ability, several ratings may be used, as described in more detail below. According to this procedure, for example, at a part thickness (e.g., 3 millimeters) discussed in more detail below, the polymer composition may exhibit at least a V1 rating, preferably a V0 rating. For example, the composition may exhibit a total flame time (V1 rating) of about 250 seconds or less, in some embodiments a total flame time of about 100 seconds or less, and in some embodiments a total flame time (V0 rating) of about 50 seconds or less.

Traditionally, it is believed that flame retardant polymer compositions exhibiting low dissipation factors and dielectric constants will not also have adequate mechanical properties. However, the inventors have found that the polymer composition is capable of maintaining excellent mechanical properties. For example, the polymer composition may exhibit about 20kJ/m when measured at various temperatures, e.g., in a temperature range of about-50 ℃ to about 85 ℃ (e.g., -40 ℃ or 23 ℃) according to ISO test No. 179-1:2010) (technically equivalent to ASTM D256-10e 1) ² Or greater simply supported beams without notch impact strength, in someIn an embodiment about 30kJ/m ² To about 80kJ/m ² And in some embodiments from about 40kJ/m to about 60 kJ/m. Tensile mechanical properties and flexural mechanical properties may also be good. For example, the polymer composition may exhibit a tensile strength of about 50MPa or greater, 300MPa, in some embodiments about 80MPa to about 500MPa, and in some embodiments, about 85MPa to about 250 MPa; about 0.5% or greater, in some embodiments about 0.6% to about 5%, and in some embodiments, about 0.7% to about 2.5%; and/or a tensile modulus of about 3,500mpa to about 20,000mpa, in some embodiments a tensile modulus of about 6,000mpa to about 15,000mpa, and in some embodiments a tensile modulus of about 8,000mpa to about 15,000 mpa. Tensile properties may be determined according to ISO test No. 527-1:2019 (technically equivalent to ASTM D638-14) at various temperatures, for example, in a temperature range of about-50℃to about 85 ℃ (e.g., -40℃or 23 ℃). The polymer composition may also exhibit a flexural strength of about 100MPa to about 500MPa, in some embodiments about 130MPa to about 400MPa, and in some embodiments about 140MPa to about 250 MPa; about 0.5% or greater, in some embodiments about 0.6% to about 5%, and in some embodiments, about 0.7% to about 2.5%; and/or a flexural modulus of about 4,500mpa to about 20,000mpa, in some embodiments a flexural modulus of about 5,000mpa to about 15,000mpa, and in some embodiments a flexural modulus of about 5,500mpa to about 12,000 mpa. Bending properties may be measured according to ISO test No. 178:2019 (technically equivalent to ASTM D790-17) at various temperatures, for example, in a temperature range of about-50 ℃ to about 85 ℃ (e.g., -40 ℃ or 23 ℃).

The polymer composition may also be less sensitive to aging at low or high temperatures. For example, the composition may be aged in an atmosphere having a temperature of about-50 ℃ to about 85 ℃ (e.g., -40 ℃ or 85 ℃) for about 100 hours or more, in some casesIn embodiments from about 300 hours to about 3000 hours, and in some embodiments, from about 400 hours to about 2500 hours (e.g., 500 or 1000 hours). Mechanical properties (e.g., impact strength, tensile properties, and/or flexural properties) may remain within the above ranges even after aging. For example, the ratio of a particular mechanical property after "aging" at 150 ℃ for 1,000 hours (e.g., notched impact strength, tensile strength, flexural strength, etc. of a simply supported beam) to the initial mechanical property prior to such aging may be about 0.6 or greater, in some embodiments about 0.7 or greater, and in some embodiments, about 0.8 to 1.0. Likewise, the sensitivity of the polymer composition to ultraviolet light is not high. For example, as described above, the polymer composition may be exposed to one or more cycles of ultraviolet light. Even upon such exposure (e.g., according to SAE J2527_2017092, the total exposure level is 2,500kJ/m ² ) Thereafter, mechanical properties (e.g., impact strength, tensile strength, bending strength, etc.) may be maintained within the above-mentioned ranges.

In certain embodiments, the composition may also provide a high degree of shielding effectiveness against electromagnetic interference ("EMI"). More specifically, the EMI shielding effectiveness may be about 20 decibels (dB) or greater, in some embodiments about 25 dB or greater, and in some embodiments, about 30 dB to about 100 dB, when measured at a frequency of 2GHz according to ASTM D4935-18. In addition to exhibiting good EMI shielding effectiveness, the composition may also exhibit a relatively low volume resistivity, such as about 5000ohm-cm or less, in some embodiments about 1000ohm-cm or less, and in some embodiments, from about 50ohm-cm to about 800ohm-cm, when measured according to D257-14.

Various embodiments of the present invention will now be described in more detail.

I.Polymer matrix

A.Propylene polymers

The polymer matrix acts as the continuous phase of the composition and comprises one or more propylene polymers. For example, the propylene polymer generally comprises from about 30wt.% to about 80wt.%, in some embodiments from about 45wt.% to about 75wt.%, and in some embodiments, from about 50wt.% to about 70wt.%, and comprises from about 30wt.% to about 65wt.%, in some embodiments, from about 35wt.% to about 60wt.%, and in some embodiments, from about 40wt.% to about 55wt.% of the total polymer composition.

Any of a variety of propylene polymers, or combinations of propylene polymers, may generally be used in the polymer matrix, such as propylene homopolymers (e.g., syndiotactic, atactic, isotactic, etc.), propylene copolymers, and the like. For example, in one embodiment, the propylene polymer that may be used is an isotactic or syndiotactic homopolymer. The term "syndiotactic" generally refers to a degree of stereoregularity in which a majority (if not all) of the methyl groups alternate on opposite sides along the polymer chain. On the other hand, the term "isotactic" generally refers to stereoregularity in which most, if not all, of the methyl groups are located on the same side along the polymer chain. Such homopolymers may have a melting point of about 160 ℃ to about 170 ℃. In other embodiments, copolymers of propylene with alpha-olefin monomers may also be used. Specific examples of suitable alpha-olefin monomers may include ethylene, 1-butene; 3-methyl-1-butene; 3, 3-dimethyl-1-butene; 1-pentene; 1-pentene having one or more methyl, ethyl or propyl substituents; 1-hexene with one or more methyl, ethyl or propyl substituents; 1-heptene having one or more methyl, ethyl or propyl substituents; 1-octene with one or more methyl, ethyl or propyl substituents; 1-nonene having one or more methyl, ethyl or propyl substituents; ethyl, methyl or dimethyl substituted 1-decene; 1-dodecene; and styrene. The propylene content of such copolymers may be from about 60 mole% to about 99 mole%, in some embodiments from about 80 mole% to about 98.5%, and in some embodiments, from about 87 mole% to about 97.5%. The alpha-olefin content may likewise be from about 1 mole% to about 40 mole%, in some embodiments from about 1.5 mole% to about 15 mole%, and in some embodiments, from about 2.5 mole% to about 13 mole%. Propylene polymers generally have a high flowability to aid in the shaping of the composition into small parts. For example, the high flow propylene polymer may have a relatively high melt flow index, such as about 150 g/10 min or greater, in some embodiments about 180 g/10 min or greater, and in some embodiments about 200 g/10 min to about 500 g/10 min, as determined according to ISO1133-1:2011 (technically equivalent to ASTM D1238-13) at a load of 2.16kg and a temperature of 230 ℃.

The propylene copolymer may generally be formed using any of a variety of known techniques. For example, free radicals or coordination catalysts (e.g., ziegler-natta) may be used to form such polymers. In some embodiments, for example, the polymer may be formed from a single site coordination catalyst, such as a metallocene catalyst. Such catalyst systems produce copolymers in which the comonomer is randomly distributed within the molecular chain and uniformly distributed at different molecular weight fractions. Examples of metallocene catalysts include bis (n-butylcyclopentadienyl) titanium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) scandium chloride, bis (indenyl) zirconium dichloride, bis (methylcyclopentadienyl) titanium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, cobaltocene, cyclopentadienyl titanium trichloride, ferrocene, hafnocene dichloride, isopropyl (cyclopentadienyl, -1-fluorenyl) zirconium dichloride, molybdenum dichloride, nickel dichloride, niobium dichloride, ruthenium dichloride, titanocene dichloride, zirconocene dichloride hydride, zirconocene dichloride, and the like. Polymers prepared using metallocene catalysts typically have a narrow molecular weight range. For example, metallocene-catalyzed polymers may have a polydispersity number (Mw/Mn) of less than 4, a controlled short chain branching distribution, and a controlled isotacticity.

B.Flame retardant systems

In addition to the above components, the polymer matrix also contains a flame retardant system to help achieve the desired combustion performance. The flame retardant system generally comprises from about 5wt.% to about 60wt.%, in some embodiments from about 6wt.% to about 50wt.%, in some embodiments from about 8wt.% to about 35wt.%, in some embodiments from about 10wt.% to about 30wt.%, and from about 1wt.% to about 50wt.%, in some embodiments from about 5wt.% to about 30wt.%, in some embodiments from about 10wt.% to about 25wt.% of the total polymer composition. The flame retardant system generally comprises at least one low halogen flame retardant. The halogen (e.g., bromine, chlorine, and/or fluorine) content of such agents is about 1500 parts per million ("ppm") (by weight) or less, in some embodiments about 900ppm or less, and in some embodiments about 50ppm or less. In certain embodiments, the flame retardant is completely halogen-free (i.e., 0 ppm). The particular properties of the halogen-free flame retardant can be selected to help achieve the desired combustion performance without adversely affecting the dielectric properties (e.g., dielectric constant, dissipation factor, etc.) and mechanical properties of the polymer composition.

For example, the system may comprise one or more organophosphorus flame retardants, such as phosphate salts, phosphate esters, phosphonate amines, phosphazenes, phosphinates, and the like, and mixtures thereof. In one embodiment, the organophosphorus flame retardant may be a nitrogen-containing phosphate salt formed from the reaction of a nitrogen-containing base and phosphoric acid. Suitable nitrogen-containing bases may include those having a substituted or unsubstituted cyclic structure with at least one nitrogen heteroatom (e.g., a heterocyclic group or heteroaryl group) in the cyclic structure and/or with at least one nitrogen-containing functional group (e.g., an amine group, an amide group, etc.) substituted at a carbon atom and/or heteroatom of the cyclic structure. Examples of such heterocyclic groups may include, for example, pyrrolidine, imidazoline, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, piperidine, piperazine, thiomorpholine, and the like. Likewise, examples of heteroaryl groups may include, for example, pyrrole, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, triazole, furazan, oxadiazole, tetrazole, pyridine, diazine, oxazine, triazine, tetrazine, and the like. The cyclic structure of the base may also be substituted with one or more functional groups, if desired, such as acyl, acyloxy, amide, alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl ester, cycloalkyl, hydroxyl, halogen, haloalkyl, heteroaryl, heterocyclyl, and the like. Substitution may occur at heteroatoms and/or carbon atoms of the cyclic structure.

One suitable nitrogen-containing base is melamine comprising a 1,3,5 triazine ring structure substituted with an amino functional group at each of the three carbon atoms. Examples of suitable melamine phosphate salts may include, for example, melamine orthophosphate, melamine pyrophosphate, melamine polyphosphate, and the like. For example, melamine pyrophosphate may comprise a molar ratio of pyrophosphate to melamine of about 1:2. Another suitable nitrogen-containing base is piperazine, which is a six-membered ring structure containing two nitrogen atoms at opposite positions of the ring. Examples of suitable piperazine phosphate salts may include, for example, piperazine orthophosphate, piperazine pyrophosphate, piperazine polyphosphate, and the like. For example, piperazine pyrophosphate may comprise a molar ratio of pyrophosphate to melamine of about 1:1. In certain embodiments, a blend of melamine and piperazine phosphate can be used in the flame retardant system. For example, the flame retardant system may comprise one or more piperazine phosphate salts (e.g., piperazine pyrophosphate) in an amount of about 40wt.% to about 90wt.%, in some embodiments about 50wt.% to about 80wt.%, and one or more melamine phosphate salts (e.g., melamine pyrophosphate) in an amount of about 10wt.% to about 60wt.%, in some embodiments about 20wt.% to about 50wt.%, and in some embodiments about 25wt.% to about 45 wt.%.

Of course, other organophosphorus flame retardants may also be used. For example, in one embodiment, monomeric and oligomeric phosphates and phosphonates may be used, such as tributyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, diphenyl 2-ethyltolyl phosphate, tri (isopropylphenyl) phosphate, resorcinol bridged oligomeric phosphate, bisphenol a phosphate (e.g., bisphenol a bridged oligomeric phosphate or bisphenol a bis (diphenyl phosphate)), and the like, as well as mixtures thereof. Phosphinates, such as phosphinic acid and/or salts of diphosphinic acid, may be used. Particularly suitable phosphinates include, for example, salts of dimethyl phosphinic acid, ethyl methyl phosphinic acid, diethyl phosphinic acid, methyl n-propyl phosphinic acid, methane-bis (methyl phosphinic acid), ethane-1, 2-bis (methyl phosphinic acid), hexane-1, 6-bis (methyl phosphinic acid), benzene-1, 4-bis (methyl phosphinic acid), methylphenyl phosphinic acid, diphenyl phosphinic acid, hypophosphorous acid, and the like. The salt produced is typically a monomeric compound; however, polymeric phosphinates may also be formed. Particularly suitable phosphinates are zinc or aluminum diethylphosphinate.

In certain embodiments, the flame retardant system may be formed entirely of organophosphorus flame retardants, such as those described above. However, in other cases, the organophosphorus flame retardant may be used in combination with one or more other additives. In such embodiments, the organophosphorus compound may constitute from about 50wt.% to about 99.5wt.%, in some embodiments from about 70wt.% to about 99wt.%, and in some embodiments, from about 80wt.% to about 95wt.%, and from about 1wt.% to about 30wt.%, in some embodiments, from about 2wt.% to about 25wt.%, and in some embodiments, from about 5wt.% to about 20wt.% of the polymer matrix of the flame retardant system.

One suitable type of additive that may be used is an inorganic compound that may be used as a low halogen char-forming agent and/or smoke suppressant. Suitable inorganic compounds (anhydrous or hydrated) may include, for example, inorganic molybdates such as zinc molybdate (e.g., available under the name Huber Engineered MaterialsCommercially available), calcium molybdate, ammonium octamolybdate, zinc molybdate-magnesium silicate, and the like. Other suitable inorganic compounds may include: inorganic borates, e.g. zinc borate (available under the name Rio Tento Minerals- >Commercially available), etc.); zinc phosphate, zinc hydrogen phosphate, zinc pyrophosphate, basic zinc (VI) chromate (zinc yellow), zinc chromite, zinc permanganate, silica, magnesium silicate, calcium carbonate, zinc oxide, titanium dioxide, magnesium hydroxide, and the like. In particular embodiments, it may be desirable to use inorganic zinc compounds, such as zinc molybdate, zinc borate, zinc oxide, and the like, to enhance the overall performance of the composition. When used, such is devoid ofThe organic compound (e.g., zinc oxide) may, for example, constitute from about 1wt.% to about 20wt.%, in some embodiments from about 2wt.% to about 15wt.%, and in some embodiments, from about 3wt.% to about 10wt.% of the flame retardant system.

Another suitable additive is a nitrogen-containing synergist, which may cooperate with the organophosphorus flame retardant and/or other components to produce a more efficient flame retardant system. Such nitrogen-containing synergists may include those having formulae (III) to (VIII), or mixtures thereof:

wherein R is ₅ 、R ₆ 、R ₇ 、R ₉ 、R ₁₀ 、R ₁₁ 、R ₁₂ And R is ₁₃ Independently is: hydrogen; c (C) ₁ -C ₈ An alkyl group; c (C) ₅ -C ₁₆ Cycloalkyl or alkylcycloalkyl, optionally hydroxy or C ₁ -C ₄ Hydroxyalkyl substitution; c (C) ₂ -C ₈ Alkenyl groups; c (C) ₁ -C ₈ Alkoxy, acyl or acyloxy; c (C) ₆ -C ₁₂ Aryl or aralkyl; OR (OR) ⁸ Or N (R) ⁸ )R ⁹ Wherein R is ⁸ Is hydrogen, C ₁ -C ₈ Alkyl, C ₅ -C ₁₆ Cycloalkyl or alkylcycloalkyl, optionally hydroxy or C ₁ -C ₄ Hydroxyalkyl group, C ₂ -C ₈ Alkenyl, C ₁ -C ₈ Alkoxy, acyl, or acyloxy, or C ₆ -C ₁₂ Aryl or aralkyl substitution;

m is 1 to 4;

n is 1 to 4;

x is an acid capable of forming an adduct with the triazine compound of formula III. For example, the nitrogen-containing synergist may include benzoguanamine, tris (hydroxyethyl) isocyanurate, allantoin, glycoluril, melamine cyanurate, dicyandiamide, guanidine, and the like. Examples of such synergists are described in U.S. Pat. No. 6,365,071 to Jenewein et al, U.S. Pat. No. 7,255,814 to Hoerold et al, and Bauer et al, U.S. patent No. 7,259,200. One particularly suitable synergist is melamine cyanurate, e.g. available under the name BASFMC (e.g.)>MC 15, MC25, MC 50) are commercially available.

As described above, the flame retardant system and/or the polymer composition itself typically has a relatively low halogen (i.e., bromine, fluorine, and/or chlorine) content, for example, about 15,000 parts per million ("ppm") or less, in some embodiments about 5,000ppm or less, in some embodiments about 1,000ppm or less, in some embodiments about 800ppm or less, and in some embodiments, about 1ppm to about 600ppm. Nevertheless, in certain embodiments of the present invention, halogen-based flame retardants may be used as an optional component. Particularly suitable halogen-based flame retardants are fluoropolymers such as Polytetrafluoroethylene (PTFE), fluorinated Ethylene Polypropylene (FEP) copolymers, perfluoroalkoxy (PFA) resins, polychlorotrifluoroethylene (PCTFE) copolymers, ethylene-chlorotrifluoroethylene (ECTFE) copolymers, ethylene-tetrafluoroethylene (ETFE) copolymers, polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF) and copolymers and blends thereof, as well as other combinations. When used, such halogen-based flame retardants typically constitute only about 10wt.% or less, in some embodiments about 5wt.% or less, and in some embodiments about 1wt.% or less of the flame retardant system. Likewise, halogen-based flame retardants typically constitute about 5wt.% or less, in some embodiments about 1wt.% or less, and in some embodiments about 0.5wt.% or less of the total polymer composition.

C.Stabilizer system

Although not required, the polymer matrix may also contain a stabilizer system to help maintain the desired surface appearance and/or mechanical properties even after exposure to ultraviolet light and high temperatures. More specifically, the stabilizer system may include one or more antioxidants (e.g., sterically hindered phenolic antioxidants, phosphite antioxidants, thioester antioxidants, etc.) and/or ultraviolet light stabilizers, as well as various other optional light stabilizers, optional heat stabilizers, and the like.

i.Antioxidant agent

One type of antioxidant that may be used in the polymer composition is a sterically hindered phenol. When used, the sterically hindered phenol is typically present in an amount of from about 0.01wt.% to about 1wt.%, in some embodiments from about 0.02wt.% to about 0.5wt.%, and in some embodiments, from about 0.05wt.% to about 0.3wt.% of the polymer composition. Although a variety of different compounds may be used, particularly suitable hindered phenol compounds are compounds having one of the following general structures (IV), (V) and (VI):

wherein, the liquid crystal display device comprises a liquid crystal display device,

a. b and c are independently 1 to 10, and in some embodiments 2 to 6;

R ⁸ 、R ⁹ 、R ¹⁰ 、R ¹¹ and R is ¹² Independently selected from hydrogen, C ₁ -C ₁₀ Alkyl and C ₃ -C ₃₀ Branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, or tert-butyl moieties; and

R ¹³ 、R ¹⁴ and R is ¹⁵ Independently selecting a moiety represented by one of the following general structures (VII) and (VIII):

d is 1 to 10, and in some embodiments 2 to 6;

R ¹⁶ 、R ¹⁷ 、R ¹⁸ and R is ¹⁹ Independently selected from hydrogen, C ₁ -C ₁₀ Alkyl and C ₃ -C ₃₀ Branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl or tert-butyl groups.

Specific examples of suitable hindered phenols having the above general structure may include, for example, 2, 6-di-t-butyl-4-cresol; 2, 4-di-tert-butylphenol; pentaerythritol tetrakis (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate; octadecyl-3- (3 ',5' -di-tert-butyl-4 ' -hydroxyphenyl) propionate; tetrakis [ methylene (3, 5-di-tert-butyl-4-hydroxycinnamate) ] methane; bis-2, 2' -methylene-bis (6-tert-butyl-4-cresol) terephthalate; 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene; tris (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate; 1,3, 5-tris (4-tert-butyl-3-hydroxy-2, 6-dimethylbenzyl) 1,3, 5-triazine-2, 4,6- (1 h,3h,5 h) -trione; 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane; 1,3, 5-triazine-2, 4,6 (1 h,3h,5 h) -trione; 1,3, 5-tris [ [3, 5-bis (1, 1-dimethylethyl) -4-hydroxyphenyl ] methyl ];4,4',4"- [ (2, 4, 6-trimethyl-1, 3, 5-benzenetriyl) tris (methylene) ] tris [2, 6-bis (1, 1-dimethylethyl) ]; 6-tert-butyl-3-methylphenyl; 2, 6-di-tert-butyl-p-cresol; 2,2' -methylenebis (4-ethyl-6-tert-butylphenol); 4,4' -butylidenebis (6-tert-butyl m-cresol); 4,4' -thiobis (6-t-butyl-m-cresol); 4,4' -dihydroxydiphenyl-cyclohexane; alkylating bisphenol; styrenated phenol; 2, 6-di-tert-butyl-4-methylphenol; n-octadecyl-3- (3 ',5' -di-tert-butyl-4 ' -hydroxyphenyl) propionate; 2,2' -methylenebis (4-methyl-6-tert-butylphenol); 4,4' -thiobis (3-methyl-6-tert-butylphenyl); 4,4' -butylidenebis (3-methyl-6-tert-butylphenol); stearyl- β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate; 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane; 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene; tetrakis [ methylene-3- (3 ',5' -di-tert-butyl-4 ' -hydroxyphenyl) propionate ] methane, stearyl 3, 5-di-tert-butyl-4-hydroxycinnamate; etc., and mixtures thereof.

Particularly suitable compounds are those having the general structure (VI), for example tris (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, which can be named3114 are commercially available.

Another suitable antioxidant is a phosphite antioxidant. When used, phosphite antioxidants are typically present in an amount of about 0.02wt.% to about 2wt.%, in some embodiments about 0.04wt.% to about 1wt.%, and in some embodiments, about 0.1wt.% to about 0.6wt.% of the polymer composition. Phosphite antioxidants may include a variety of different compounds such as aryl monophosphites, aryl bisphosphites, and the like, as well as mixtures thereof. For example, aryl bisphosphites having the following general structure (IX) may be used:

wherein R is ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ 、R ₆ 、R ₇ 、R ₈ 、R ₉ And R is ₁₀ Independently selected from hydrogen, C ₁ -C ₁₀ Alkyl and C ₃ -C ₃₀ Branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl or tert-butyl moieties.

Examples of such aryl bisphosphite compounds may include, for example, bis (2, 4-dicumylphenyl) pentaerythritol bisphosphite (mayS-9228 is commercially available) and bis (2, 4-di-tert-butylphenyl) pentaerythritol bisphosphite (which may be +.>626 commercially available). Likewise, suitable aryl monophosphites may include tris (2, 4-di-tert-butylphenyl) phosphite (in +. >168 commercially available), bis (2, 4-di-tert-butyl-6-methylphenyl) ethyl phosphite (as/>38 commercially available), and so forth.

Yet another suitable antioxidant is a thioester antioxidant. When used, the thioester antioxidant is typically present in an amount of about 0.04wt.% to about 4wt.%, in some embodiments about 0.08wt.% to about 2wt.%, and in some embodiments, about 0.2wt.% to about 1.2wt.% of the polymer composition. Thioester antioxidants particularly suitable for use in the present invention are thiocarboxylic esters such as those having the general structure:

R ₁₁ -O(O)(CH ₂ ) _x -S-(CH ₂ ) _y (O)O-R ₁₂

x and y are independently 1 to 10, in some embodiments 1 to 6, and in some embodiments 2 to 4 (e.g., 2);

R ₁₁ and R is ₁₂ Independently selected from linear or branched C ₆ -C ₃₀ Alkyl, in some embodiments C ₁₀ -C ₂₄ Alkyl, and in some embodiments C ₁₂ -C ₂₀ Alkyl groups such as lauryl, stearyl, octyl, hexyl, decyl, dodecyl, oleyl, and the like.

Specific examples of suitable thiocarboxylates may include, for example, distearyl thiodipropionate (which mayPS 800 commercially available), dilaurylthiodipropionate (in +.>PS 802 commercially available), di-2-ethylhexyl thiodipropionate, diisodecyl thiodipropionate, and the like.

In particularly suitable embodiments of the present invention, a combination of antioxidants may be used to help provide a synergistic effect on the characteristics of the composition. For example, in one embodiment, the stabilizer system may use a combination of at least one sterically hindered antioxidant, phosphite antioxidant, and thioester antioxidant. When used, the weight ratio of phosphite antioxidant to hindered phenol antioxidant may be from about 1:1 to about 5:1, in some embodiments from about 1:1 to about 4:1, and in some embodiments, from about 1.5:1 to about 3:1 (e.g., about 2:1). The weight ratio of thioester stabilizer to phosphite antioxidant is typically from about 1:1 to about 5:1, in some embodiments from about 1:1 to about 4:1, and in some embodiments, from about 1.5:1 to about 3:1 (e.g., about 2:1). Likewise, the weight ratio of thioester antioxidant to hindered phenol antioxidant is also typically from about 2:1 to about 10:1, in some embodiments from about 2:1 to about 8:1, and in some embodiments, from about 3:1 to about 6:1 (e.g., about 4:1). Within these selected ratios, the composition is believed to achieve a unique ability to remain stable even after exposure to high temperatures and/or ultraviolet light.

The polymer composition may also comprise one or more UV stabilizers. Suitable UV stabilizers may include, for example, benzophenone (e.g., (2-hydroxy-4- (octyloxy) phenyl, methanone @81 Benzotriazole (e.g., 2- (2-hydroxy-3, 5-di-alpha-cumylphenyl) -2H-benzotriazole (-/-)>234 2- (2-hydroxy-5-tert-octylphenyl) -2H-benzotriazole (+.>329 2- (2-hydroxy-3-alpha-cumyl-5-tert-octylphenyl) -2H-benzotriazole928 (2, 4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -s-triazine (-/-), etc.)>1577 A) sterically hindered amine (e.g., bis)(2, 6-tetramethyl-4-piperidinyl) sebacate (++>770 Polymer of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2, 6-tetramethyl-4-piperidine (/ -)>622 And the like, as well as mixtures thereof. Benzophenone is particularly suitable for use in polymeric compositions. When used, such uv stabilizers generally constitute from about 0.05wt.% to about 2wt.%, in some embodiments from about 0.1wt.% to about 1.5wt.%, and in some embodiments, from about 0.2wt.% to about 1.0wt.% of the composition.

D.Other components

In addition to the above components, the polymer matrix may also contain various other components. Examples of such optional components may include, for example, EMI fillers, compatibilizers, particulate fillers, lubricants, colorants, flow improvers, pigments, and other materials added to enhance properties and processability. For example, when EMI shielding characteristics are desired, EMI fillers may be used. EMI fillers are typically formed from electrically conductive materials that provide a desired degree of electromagnetic interference shielding. In certain embodiments, for example, the material comprises a metal such as stainless steel, aluminum, zinc, iron, copper, silver, nickel, gold, chromium, and the like, as well as alloys or mixtures thereof. EMI fillers can also take a variety of different forms, such as particles (e.g., iron powder), flakes (e.g., aluminum flakes, stainless steel flakes, etc.), or fibers. Particularly suitable EMI fillers are metal-containing fibers. In such embodiments, the fibers may be formed primarily of metal (e.g., stainless steel fibers), or the fibers may be formed of a core material coated with metal. When a metal cladding is used, the core material may be formed of a material that is conductive or insulating in nature. For example, the core material may be formed of carbon, glass, or a polymer. One example of such a fiber is a nickel-coated carbon fiber.

Compatibilizers may also be used to increase the degree of adhesion between the long fibers and the polymer matrix. When used, such compatibilizers typically constitute from about 0.1wt.% to about 15wt.%, in some embodiments from about 0.5wt.% to about 10wt.%, and in some embodiments, from about 1wt.% to about 5wt.% of the polymer composition. In certain embodiments, the compatibilizing agent may be a polyolefin compatibilizing agent comprising a polyolefin modified with polar functional groups. The polyolefin may be an olefin homopolymer (e.g., polypropylene) or copolymer (e.g., ethylene copolymer, propylene copolymer, etc.). The functional groups may be grafted onto the polyolefin backbone, incorporated as monomer components of the polymer (e.g., block or random copolymers), or the like. Particularly suitable functional groups include maleic anhydride, maleic acid, fumaric acid, maleimide, maleic acid hydrazide, reaction products of maleic anhydride and diamines, dichloromaleic anhydride, maleic acid amide, and the like.

Regardless of the particular components used, the raw materials (e.g., thermoplastic polymers, flame retardants, stabilizers, compatibilizers, etc.) are typically melt blended together to form a polymer matrix prior to reinforcement with long fibers. The raw materials may be supplied simultaneously or sequentially to a melt blending device that dispersedly blends the materials. Batch and/or continuous melt blending techniques may be used. For example, a mixer/kneader, banbury mixer, farrel continuous mixer, single screw extruder, twin screw extruder, roll mill, or the like may be used to blend the materials. One particularly suitable melt blending apparatus is a co-rotating twin screw extruder (e.g., a ZSK-30 twin screw extruder, available from Werner & Pfleiderer Corporation of Ramsey, N.J.). Such extruders may include a feed port and a discharge port and provide high intensity distributed and dispersive mixing. For example, the propylene polymer may be fed to the feed port of a twin screw extruder and melted. Thereafter, the stabilizer may be injected into the polymer melt. Alternatively, the stabilizer may be fed to the extruder separately at different points along the length of the extruder. Regardless of the particular melt blending technique selected, the raw materials are blended under high shear/pressure and heat to ensure thorough mixing. For example, melt blending may be performed at a temperature of about 150 ℃ to about 300 ℃, in some embodiments about 155 ℃ to about 250 ℃, and in some embodiments about 160 ℃ to about 220 ℃.

As noted above, certain embodiments of the present invention contemplate the use of a blend of polymers within a polymer matrix (e.g., a propylene homopolymer and/or a propylene/α -olefin copolymer). In such embodiments, each polymer used in the blend may be melt blended in the manner described above. However, in other embodiments, it may be desirable to melt blend a first polymer (e.g., a propylene polymer) to form a concentrate, and then reinforce with long fibers in the manner described below to form a precursor composition. Thereafter, the precursor composition can be blended (e.g., dry blended) with a second polymer (e.g., a propylene polymer) to form a polymer composition having desired properties. It will also be appreciated that other polymers may also be added before and/or during the reinforcement of the polymer matrix with long fibers.

II.Long fiber

To form the fiber reinforced compositions of the present invention, the long fibers are typically embedded within a polymer matrix. For example, the long fibers may constitute from about 10wt.% to about 40wt.%, in some embodiments from about 12wt.% to about 38wt.%, and in some embodiments, from about 15wt.% to about 35wt.% of the composition. Likewise, the polymer matrix generally comprises from about 60wt.% to about 90wt.%, in some embodiments from about 62wt.% to about 88wt.%, and in some embodiments, from about 65wt.% to about 85wt.% of the composition.

The term "long fibers" generally refers to discontinuous fibers, filaments, yarns, or rovings (e.g., bundles) having a length of about 1 millimeter to about 25 millimeters, in some embodiments about 1.5 millimeters to about 20 millimeters, in some embodiments about 2 millimeters to about 15 millimeters, and in some embodiments about 3 millimeters to about 12 millimeters. Even after forming the molded part (e.g., injection molding), a substantial portion of the fibers may remain relatively long. That is, the median length (D50) of the fibers in the composition may be about 1 millimeter or greater, in some embodiments about 1.5 millimeters or greater, in some embodiments about 2.0 millimeters or greater, and in some embodiments, about 2.5 millimeters to about 8 millimeters. Regardless of its length, the nominal diameter of the fibers (e.g., the diameter of the fibers within the roving) can be selectively controlled to help improve the surface appearance of the resulting polymer composition. More specifically, the nominal diameter of the fibers may be from about 20 microns to about 40 microns, in some embodiments from about 20 microns to about 30 microns, and in some embodiments, from about 21 microns to about 26 microns. Within this range, the tendency of the fibers to "bunch up" on the surface of the molded part is reduced, which results in the color and surface appearance of the part being primarily from the polymer matrix. In addition to providing improved aesthetic consistency, it may also allow better color retention after exposure to ultraviolet light, as the stabilizer system may be more easily used within the polymer matrix. Of course, it should be understood that other nominal diameters may be used, such as nominal diameters of about 1 micron to about 20 microns, in some embodiments about 8 microns to about 19 microns, and in some embodiments, about 10 microns to about 18 microns.

The fibers may be formed from any conventional material known in the art, such as metal fibers, glass fibers (e.g., E-glass, a-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass), carbon fibers (e.g., graphite), boron fibers, ceramic fibers (e.g., alumina or silica), aramid fibers (e.g.,) Synthetic organic fibers (e.g., polyamides, polyethylenes, para-phenylenes, terephthalamides, polyethylene terephthalates, and polyphenylene sulfides), the aforementioned metal fibers (e.g., stainless steel fibers), and various other natural or synthetic inorganic or organic fiber materials known for reinforcing thermoplastic compositions. Glass fibers, especially S-glass fibers, are particularly desirable. The fibers may be twisted or straight. The fibers may be in the form of rovings (e.g., fiber bundles) comprising a single fiber type or different fiber types, if desired. Different fibers may be included within each roving, or alternatively, each roving may include different types of fibersDimension. For example, in one embodiment, some rovings may comprise carbon fibers, while other rovings may comprise glass fibers. The number of fibers contained in each roving may be constant or may vary from roving to roving. Typically, the roving may comprise from about 1,000 fibers to about 50,000 individual fibers, and in some embodiments, from about 2,000 fibers to about 40,000 fibers. / >

The fibers can generally be incorporated into the polymer matrix using any of a variety of different techniques. The long fibers may be randomly distributed within the polymer matrix or alternatively, may be distributed in an aligned manner. For example, in one embodiment, the continuous fibers may initially be immersed in a polymer matrix to form strands (strands) that are subsequently cooled and then cut into pellets to provide the resulting fibers with the desired length of long fibers. In such embodiments, the polymer matrix and continuous fibers (e.g., rovings) are typically pultruded through an impregnation die to achieve the desired contact between the fibers and the polymer. Pultrusion also helps ensure that the fibers are spaced apart and aligned in the same or substantially similar direction, for example in a longitudinal direction parallel to the long axis (e.g., length) of the pellet, which further improves mechanical properties. For example, referring to fig. 1, one embodiment of a pultrusion process 10 is shown wherein a polymer matrix is supplied from an extruder 13 to an impregnation die 11, and continuous fibers 12 are pulled through die 11 by a puller device 18 to create a composite structure 14. Typical puller devices may include, for example, crawler-type pullers and reciprocating pullers. Although optional, the composite structure 14 may also be pulled through a cladding mold 15, the cladding mold 15 being connected to an extruder 16, through which extruder 16 a cladding resin is applied to form a cladding structure 17. As shown in fig. 1, the coated structure 17 is then pulled through a puller assembly 18 and supplied to a pelletizer 19, which pelletizer 19 cuts the structure 17 to the desired size to form a long fiber reinforced composition.

The nature of the impregnation die used during the pultrusion process may be selectively varied to help achieve good contact between the polymer matrix and the long fibers. Examples of suitable impregnation die systems are described in detail in Hawley reissue patent No. 32,772, regan et al patent No. 9,233,486, and Eastep et al patent No. 9,278,472. For example, referring to fig. 2, one embodiment of such a suitable impregnation die 11 is shown. As shown, the polymer matrix 127 may be supplied to the impregnation die 11 by an extruder (not shown). More specifically, the polymer matrix 127 may exit the extruder through barrel flange 128 and enter a die flange 132 of die 11. The mold 11 includes an upper mold half 134 that mates with a lower mold half 136. Continuous fibers 142 (e.g., rovings) are supplied from spools 144 through feed ports 138 to upper mold half 134 of mold 11. Similarly, continuous fibers 146 are also supplied from spool 148 through feed port 140. The substrate 127 is heated within the mold halves 134 and 136 by a heater 133 mounted in the upper mold half 134 and/or the lower mold half 136. The mold is typically operated at a temperature sufficient to cause melting and impregnation of the thermoplastic polymer. Typically, the mold is operated at a temperature above the melt temperature of the polymer matrix. When processed in this manner, continuous fibers 142 and 146 become embedded in matrix 127. The mixture is then pulled through the impregnation die 11 to form the fiber reinforced composition 152. The pressure sensor 137 may also sense the pressure near the impregnation die 11 if necessary in order to control the extrusion rate by controlling the rotational speed of the screw shaft or the linkage of the feeder.

Within the impregnation die, it is generally desirable that the fibers contact a series of impingement areas. In these areas, the polymer melt may flow laterally through the fibers to create shear and pressure forces, thereby significantly increasing the degree of impregnation. This is particularly useful when forming composite materials from high fiber content ribbons. Typically, the die will contain at least 2, in some embodiments at least 3, and in some embodiments 4 to 50 impact regions per roving to produce a sufficient degree of shear and pressure. Although their specific forms may vary, the impact region typically has a curved surface, such as curved lobes, stems, and the like. The impact area is also typically made of a metallic material.

Fig. 2 shows an enlarged schematic view of a portion of the impregnation die 11, the impregnation die 11 comprising a plurality of impingement areas 182 in the form of lobes. It should be understood that the present invention may be practiced using multiple feed ports, which may optionally be coaxial with the machine direction. The number of feed ports used may vary with the number of fibers processed at one time in the die, and the feed ports may be installed in either the upper die half 134 or the lower die half 136. The feed port 138 includes a sleeve 170 mounted in the upper mold half 134. The feed port 138 is slidably mounted in a sleeve 170. The feed port 138 is divided into at least two pieces, shown as pieces 172 and 174. The feed port 138 has an aperture 176 longitudinally therethrough. The aperture 176 may be in the shape of a right cylindrical tapered opening away from the upper mold half 134. Fibers 142 pass through apertures 176 and into channel 180 between upper mold half 134 and lower mold half 136. A series of lobes 182 are also formed in the upper mold half 134 and the lower mold half 136 so that the channel 210 takes a tortuous path. The plurality of lobes 182 pass the fibers 142 and 146 through at least one of the lobes such that the polymer matrix within the channel 180 is in full contact with each of the fibers. In this way, full contact between the molten polymer and fibers 142 and 146 is ensured.

To further facilitate impregnation, the fibers may also be held under tension when present in the impregnation die. For example, the tension may be about 5 newtons to about 300 newtons per fiber strand (tow), in some embodiments about 50 newtons to about 250 newtons, and in some embodiments, about 100 newtons to about 200 newtons. In addition, the fibers may also pass through the impingement zone in a circuitous path to enhance shear forces. For example, in the embodiment shown in fig. 2, the fibers traverse the impact region in a sinusoidal path. The angle at which the roving traverses from one impact zone to another is typically high enough to enhance shear, but not so high as to cause excessive forces to break the fibers. Thus, for example, the angle may be from about 1 ° to about 30 °, and in some embodiments, from about 5 ° to about 25 °.

The impregnation die shown and described above is but one of the various possible configurations that may be used in the present invention. In alternative embodiments, for example, the fibers may be introduced into a cross-head die that is disposed at an angle relative to the flow direction of the polymer melt. As the fibers move through the crosshead die and reach the point where the polymer exits the extruder barrel, the polymer is forced into contact with the fibers. It should also be appreciated that any other extruder design may be used, such as a twin screw extruder. In addition, other components may optionally be used to assist in the impregnation of the fibers. For example, in certain embodiments a "gas jet" assembly may be employed to help uniformly spread the bundles or tows of individual fibers (which may each contain up to 24,000 fibers) across the width of the fused tows. This helps achieve an even distribution of the intensity characteristics in the streamer. Such an assembly may include a supply of compressed air or another gas that impinges the moving fiber bundles through the outlet port in a substantially vertical manner. The spread fiber bundles may then be introduced into a mold for impregnation, for example as described above.

Fiber reinforced polymer compositions can generally be used to form molded parts using a variety of different techniques. Suitable techniques may include, for example, injection molding, low pressure injection molding, extrusion compression molding, gas injection molding, foam injection molding, low pressure gas injection molding, low pressure foam injection molding, gas extrusion compression molding, foam extrusion compression molding, extrusion molding, foam extrusion molding, compression molding, foam compression molding, gas compression molding, and the like. For example, an injection molding system may be used that includes a mold into which the fiber-reinforced composition may be injected. The time within the syringe may be controlled and optimized so that the polymer matrix is not pre-cured. When the cycle time is reached and the barrel is fully loaded for discharge, a piston may be used to inject the composition into the mold cavity. Compression molding systems may also be used. As with injection molding, shaping the fiber reinforced composition into the desired article also occurs within the mold. The composition may be placed into a compression mold using any known technique, such as being picked up by an automated robotic arm. The temperature of the mold may be maintained at or above the curing temperature of the polymer matrix for a desired period of time to allow curing. The shaped product may then be cured by bringing the shaped product to a temperature below the melting temperature. The resulting product may be demolded. The cycle time of each molding process can be adjusted to accommodate the polymer matrix, achieve adequate bonding, and increase overall process productivity. Because of the unique properties of the fiber reinforced composition, relatively thin molded parts (e.g., injection molded parts) can be easily formed therefrom. For example, the thickness of such components may be about 10 millimeters or less, in some embodiments about 8 millimeters or less, in some embodiments about 6 millimeters or less, in some embodiments about 0.4 millimeters to about 5 millimeters, and in some embodiments about 0.8 millimeters to about 4 millimeters (e.g., 0.8 millimeters, 1.2 millimeters, or 3 millimeters).

II.Application of

Due to their unique properties, the polymer compositions can be used in a variety of electronic devices and systems. For example, in some embodiments, the device may be an electronic module that includes a housing that houses one or more electronic components (e.g., printed circuit boards, antenna elements, radio frequency sensing elements, sensors, light sensing and/or transmitting elements (e.g., optical fibers), cameras, global positioning devices, etc.). For example, the housing may include a base including a sidewall extending therefrom. The cover may also be supported on a side wall of the base to define an interior in which the electronic components are housed and protected from the external environment. Regardless of the specific configuration of the module, the polymer composition of the present invention may be used to form all or part of the housing and/or cover. For example, in one embodiment, the polymer composition of the present invention may be used to form the base and sidewalls of an enclosure. In such embodiments, the cap may be formed from the polymer composition of the present invention or from a different material such as a metal member (e.g., an aluminum plate). It is noted that one benefit of the present invention is that the linear thermal expansion coefficient of the polymer composition is similar to typical metal components used in electronic modules. For example, the linear thermal expansion coefficient of the polymer composition may be from about 10 μm/m ℃ to about 35 μm/m ℃, in some embodiments from about 12 μm/m ℃ to about 32 μm/m ℃, and in some embodiments, from 15 μm/m ℃ to about 30 μm/m ℃ when measured in the flow direction (parallel) according to ISO 11359-2:1999. Further, the ratio of the linear thermal expansion coefficient of the polymer composition to the linear thermal expansion coefficient of the metal member may be from about 0.5 to about 1.5, in some embodiments from about 0.6 to about 1.2, and in some embodiments, from about 0.6 to about 1.0. For example, aluminum has a linear thermal expansion coefficient of about 21 μm/mdeg.C to 24 μm/mdeg.C.

For example, referring to fig. 3, one embodiment of an electronic module 100 that may include the polymer composition of the present invention is shown. The electronic module 100 includes a housing 102, the housing 102 including side walls 132 extending from the base 114. The housing 102 may also include a shroud 116 that can house electrical connectors (not shown), if desired. In any event, a printed circuit board ("PCB") is received inside the module 100 and connected to the housing 102. More specifically, circuit board 104 includes an aperture 122, aperture 122 being aligned with and receiving post 110 on housing 102. The circuit board 104 has a first surface 118, and circuitry 121 is provided on the first surface 118 to allow radio frequency operation of the module 100. For example, the radio frequency circuit 121 may include one or more antenna elements 120a and 120b. The circuit board 104 also has a second surface 119 opposite the first surface 118, and may optionally include other electrical components, such as components that allow digital electronic operation of the module 100 (e.g., digital signal processors, semiconductor memory, input/output interface devices, etc.). Alternatively, such components may be provided on additional printed circuit boards. A cover 108 may also be used, with the cover 108 being disposed on the circuit board 104 and attached to the housing 102 (e.g., side walls) by known techniques (e.g., soldering, adhesive, etc.) to seal the electrical components inside. As described above, the polymer composition may be used to form all or part of the cover 108 and/or housing 102.

Electronic modules may be used in a variety of applications. For example, the electronic module may be used in an automotive vehicle (e.g., an electric vehicle). For example, when used in automotive applications, the electronic module may be used to sense the positioning of the vehicle relative to one or more three-dimensional objects. In this regard, the module may include radio frequency sensing means, light detection or optical means, cameras, antenna elements, and the like, as well as combinations thereof. For example, the module may be a radio detection and ranging ("radar") module, a light detection and ranging ("light arrival") module, a camera module, a global positioning module, etc., or may be an integrated module that incorporates two or more of these components. Thus, such modules may use a housing that receives one or more types of electronic components (e.g., printed circuit boards, antenna elements, radio frequency sensing devices, sensors, light sensing and/or transmitting elements (e.g., optical fibers), cameras, global positioning devices, etc.). For example, in one embodiment, a light module may be formed that includes a fiber optic assembly for receiving and emitting light pulses that is received within the interior of the housing/cover assembly in a manner similar to the embodiments discussed above. Similarly, radar modules typically include one or more printed circuit boards with electrical components dedicated to processing Radio Frequency (RF) radar signals, digital signal processing tasks, and the like.

The electronic module may also be used in a 5G system. For example, the electronic module may be an antenna module, such as a macro cell (base station), a small cell, a micro cell, or a repeater (femto cell), etc. As used herein, "5G" generally refers to high-speed data communication via radio frequency signals. The 5G network and system are capable of data communication at a much faster rate than the previous data communication standards (e.g. "4G", "LTE"). Various standards and specifications have been promulgated to quantify the requirements of 5G communications. As an example, the International Telecommunications Union (ITU) promulgated the international mobile communications-2020 ("IMT-2020") standard in 2015. The IMT-2020 standard specifies various data transmission standards (e.g., downstream and upstream data rates, delays, etc.) for 5G. The IMT-2020 standard defines the upstream and downstream peak data rates as the lowest data rates that the 5G system must support for uploading and downloading data. The IMT-2020 standard specifies a downstream peak data rate requirement of 20Gbit/s and an upstream peak data rate of 10Gbit/s. As another example, the third generation partnership project (3 GPP) recently released a new standard of 5G, referred to as "5G NR". The 3GPP released "release 15" in 2018, defining a "first stage" of standardization of 5G NR. The 3GPP defines the 5G band generally as "frequency range 1" (FR 1) including frequencies below 6GHz and "frequency range 2" (FR 2) for the 20-60GHz band. However, as used herein, "5G frequency" may refer to systems that use frequencies greater than 60GHz, such as up to 80GHz, up to 150GHz, and up to 300 GHz. As used herein, "5G frequency" may refer to a frequency of about 1.8GHz or higher, in some embodiments about 2.0GHz or higher, in some embodiments about 3.0GHz or higher, in some embodiments about 3GHz to about 300GHz, or higher, in some embodiments about 4GHz to about 80GHz, in some embodiments about 5GHz to about 80GHz, in some embodiments about 20GHz to about 80GHz, and in some embodiments about 28GHz to about 60GHz.

A 5G antenna system typically uses high frequency antennas and antenna arrays for 5G components, such as macro cells (base stations), small cells, micro cells or repeaters (femtocells), etc., and/or other suitable components for 5G systems. The antenna elements/arrays and systems may meet or conform to a 3GPP release standard such as "5G" under release 15 (2018), and/or "5G" under IMT-2020 standard. To achieve high-speed data communications at such high frequencies, antenna elements and arrays typically use small feature sizes/pitches (e.g., fine pitch technology) that can improve antenna performance. For example, the feature size (spacing between antenna elements, width of antenna elements), etc., typically depends on the desired wavelength ("λ") (e.g., nλ/4, where n is an integer) of the transmitted and/or received radio frequency propagating through the substrate on which the antenna elements are formed. Furthermore, beamforming and/or beam steering may be used to facilitate reception and transmission across multiple frequency ranges or channels (e.g., multiple-input multiple-output (MIMO), massive MIMO). The high frequency 5G antenna element may have a variety of configurations. For example, the 5G antenna element may be or include a coplanar waveguide element, a patch array (e.g., a grid patch array), other suitable 5G antenna configuration. The antenna elements may be configured to provide MIMO, massive MIMO functions, beam steering, and the like. As used herein, a "massive" MIMO function generally refers to providing a large number of transmission and reception channels, e.g., 8 transmission (Tx) channels and 8 reception (Rx) channels (abbreviated as 8 x 8), with an antenna array. Massive MIMO functionality may be provided in 8 x 8, 12 x 12, 16 x 16, 32 x 32, 64 x 64, or more.

The antenna elements may be fabricated using a variety of fabrication techniques. As one example, the antenna elements and/or related elements (e.g., ground elements, feed lines, etc.) may employ fine pitch technology. Fine pitch technology generally refers to small or fine pitches between its components or wires. For example, the feature size and/or spacing between antenna elements (or between antenna elements and ground plane) may be about 1500 microns or less, in some embodiments 1250 microns or less, in some embodiments 750 microns or less (e.g., center-to-center spacing of 1.5mm or less), 650 microns or less, in some embodiments 550 microns or less, in some embodiments 450 microns or less, in some embodiments 350 microns or less, in some embodiments 250 microns or less, in some embodiments 150 microns or less, in some embodiments 100 microns or less, and in some embodiments 50 microns or less. However, it should be understood that smaller and/or larger feature sizes and/or pitches may also be used. Due to this small feature size, an antenna configuration and/or array may be implemented with a large number of antenna elements in a small footprint. For example, the average antenna element concentration of the antenna array may be greater than about 1,000 antenna elements per square centimeter, in some embodiments greater than 2,000 antenna elements per square centimeter, in some embodiments greater than 3,000 antenna elements per square centimeter, in some embodiments greater than 4,000 antenna elements per square centimeter, in some embodiments greater than 6,000 antenna elements per square centimeter, and in some embodiments greater than about 8,000 antenna elements per square centimeter. Such a compact arrangement of antenna elements may provide a greater number of channels for MIMO functionality per unit area of antenna area. For example, the number of channels may correspond to (e.g., be equal to or proportional to) the number of antenna elements.

Referring to fig. 4, for example, the 5G antenna system 100 may include a base station 102, one or more relay stations 104, one or more user computing devices 106, one or more Wi-Fi relays 108 (e.g., "femtocells"), and/or other suitable antenna components for the 5G antenna system 100. Relay 104 may be configured to facilitate communications with base station 102 through user computing device 106 and/or other relay 104 by relaying forwarded or "repeated" signals between base station 102 and user computing device 106 and/or relay 104. Base station 102 may include a MIMO antenna array 110, MIMO antenna array 110 configured to receive and/or transmit radio frequency signals 112 with relay station 104, wi-Fi repeater 108, and/or directly with user computing device 106. The user computing device 306 is not necessarily limited by the invention and includes devices such as a 5G smart phone. MIMO antenna array 110 may focus or steer radio frequency signals 112 with respect to beam steering of relay station 104. For example, MIMO antenna array 110 may be configured to adjust an elevation angle 114 relative to the X-Y plane and/or a yaw angle 116 defined in the Z-Y plane and relative to the Z-direction. Similarly, one or more of the relay station 104, the user computing device 106, the Wi-Fi repeater 108 may employ beam steering to improve the receiving and/or transmitting capabilities with respect to the MIMO antenna array 110 by steering the sensitivity and/or power transmission of the devices 104, 106, 108 with respect to the MIMO antenna array 110 of the base station 102 (e.g., by adjusting one or both of the relative elevation and/or relative azimuth of the devices).

The invention will be better understood with reference to the following examples.

Test method

Melt flow index: the melt flow index of the polymer or polymer composition can be determined according to ISO 1133-1:2011 (technically equivalent to ASTM D1238-13) under a load of 2.16kg and at a temperature of 230 ℃.

Tensile modulus, tensile stress, and tensile elongation at break: tensile properties may be tested according to ISO test No. 527-1:2019 (technically equivalent to ASTM D638-14). Modulus and strength measurements can be made on dog bone test strip specimens having a length of 170/190mm, a thickness of 4mm and a width of 10 mm. The test temperature may be-30 ℃, 23 ℃ or 80 ℃, and the test speed may be 1mm/min or 5mm/min.

Flexural modulus, elongation at break at bend and flexural stress: flexural performance can be tested according to ISO test No. 178:2019 (technically equivalent to ASTM D790-17). The test can be performed over a support span of 64 mm. Testing can be performed on the center portion of an uncut ISO 3167 multipurpose stick. The test temperature may be-30 ℃, 23 ℃ or 80 ℃, and the test speed may be 2mm/min.

Impact strength of simple beam: simply supported beam performance may be tested according to ISO test No. 179-1:2010 (technically equivalent to ASTM D256-10). The test can be performed using type 1 specimen dimensions (80 mm in length, 10mm in width, and 4mm in thickness). The sample may be cut from the center of the multipurpose rod using a single tooth milling machine. The test temperature may be-30 ℃, 23 ℃ or 80 ℃.

Deflection temperature under load ("DTUL"): the deflection temperature under load can be determined according to ISO test No. 75-2:2013 (technically equivalent to ASTM D648-07). More specifically, test strip specimens having a length of 80mm, a width of 10mm, and a thickness of 4mm can be subjected to a three point bending along edge test, with a specified load (maximum external fiber stress) of 1.8 megapascals. The sample may be lowered into a silicone oil bath with the temperature rising at 2 ℃ per minute until the sample flexes 0.25mm (0.32 mm for ISO test No. 75-2:2013).

Coefficient of linear thermal expansion ("CLTE"): the linear thermal expansion coefficient may be determined in the flow direction and/or in the transverse direction according to ISO 11359.

Dielectric constant ("Dk") and dissipation factor ("Df"): the dielectric constant (or relative electrostatic permittivity) and dissipation factor (or loss tangent) were determined according to IPC 650 test method No. 2.5.5.13 (1/07) at a frequency of 2 GHz. According to this method, the in-plane dielectric constant and dissipation factor can be determined using split cylinder resonators. The test specimen had a thickness of 8.175mm, a width of 70mm and a length of 70mm.

Limiting oxygen index: limiting oxygen index ("LOI") can be determined by ISO 4589:2017 (technically equivalent to ASTM D2863-19). LOI refers to the lowest oxygen concentration in a flowing mixture of oxygen and nitrogen that is just capable of supporting flame combustion. More specifically, the sample may be placed vertically in a transparent test column and a mixture of oxygen and nitrogen may be forced upward through the column. The sample may be ignited at the top. The oxygen concentration may be adjusted until the sample just supports combustion. The reported concentrations are the volume percent of oxygen just supporting combustion for the sample.

UL94: the specimen is supported in a vertical position and a flame is applied to the bottom of the specimen. The flame was applied for ten (10) seconds, then the flame was removed until combustion ceased, at which time the flame was again applied for another ten (10) seconds, then the flame was removed. Two (2) sets of five (5) samples were tested. The sample dimensions were 125mm long, 13mm wide, and 3mm thick. Both groups were conditioned before and after aging. For the unaged test, each thickness was tested after conditioning at 23 ℃ and 50% relative humidity for 48 hours. For the aging test, five (5) samples of each thickness were tested after conditioning at 70 ℃ for 7 days.

Example 1

A sample was formed comprising about 45wt.% propylene homopolymer (melt flow index 65g/10min, density 0.90g/cm ³ ) 35wt.% of a flame retardant masterbatch, 20wt.% of a continuous glass fiber roving (2400 Tex, filament diameter 16 μm), less than 5wt.% of a coupling agent (maleic anhydride grafted olefin polymer), and less than 2wt.% of a thermal/UV stabilizer. The flame retardant masterbatch contains 40wt.% polypropylene and 60wt.% of a halogen-free flame retardant system comprising the phosphorus-based flame retardant described above. The samples were melt processed in a single screw extruder (90 mm) with a melt temperature of 250 ℃, a die temperature of 250 ℃, and a zone temperature of 160 ℃ to 320 ℃, and a screw speed of 160rpm.

Example 2

A sample was formed comprising about 50wt.% propylene homopolymer (melt flow index 65g/10min, density 0.90g/cm ³ )、30wt.％As described in the examples, 20wt.% of continuous glass fiber rovings (2400 Tex, filament diameter 16 μm), less than 5wt.% of coupling agent (maleic anhydride grafted olefin polymer), and less than 2wt.% of thermal/UV stabilizer. The samples were melt processed in a single screw extruder (90 mm) with a melt temperature of 250 ℃, a die temperature of 250 ℃, and a zone temperature of 160 ℃ to 320 ℃, and a screw speed of 160rpm.

Samples of examples 1-2 were tested for dielectric, mechanical and flame retardant properties. The results are set forth in the following table.

	Example 1	Example 2
			Tensile Strength at 23 ℃ (MPa)	91	90
Flexural Strength at 23 ℃ (MPa)	145	141
			Flexural modulus (MPa) at 23 ℃	5,988	5,574
Notched impact Strength (kJ/m) of a simply supported beam at 23 ℃ ² )	48.8	49.6
			Flame retardant Property of 3mm (UL 94)	V0	V0
Dielectric constant of 2GHz	3.07	2.93
			Dissipation factor of 2GHz	0.0024	0.0021

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. Additionally, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will recognize that the foregoing description is by way of example only, and is not intended to limit the invention from that further described in the claims that follow.

Claim (modification according to treaty 19)

1. A fiber reinforced polymer composition comprising about 60wt.% to about 90wt.% of a polymer matrix comprising a propylene polymer and about 10wt.% to about 40wt.% of a plurality of long reinforcing fibers distributed within the polymer matrix, wherein the polymer composition exhibits a dielectric constant of about 4 or less and a dissipation factor of about 0.01 or less at a frequency of 2GHz, and wherein the polymer composition exhibits a dissipation factor of about 20kJ/m as measured according to ISO test No. 179-1:2010 at a temperature of about 23 ℃ ² Or greater notched impact strength, and a limiting oxygen index of about 25 or greater as determined according to ISO 4589:2017.

2. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits a V0 rating or a V1 rating according to UL 94.

3. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits a total flame time of about 250 seconds or less according to UL 94.

4. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits a flexural strength of about 100MPa to about 500MPa measured according to ISO test No. 178:2019 at a temperature of about 23 ℃.

5. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits about 20kJ/m measured at a temperature of about-40 ℃ according to ISO test No. 179-1:2010 ² Or greater simply supported beams without notched impact strength.

6. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits a tensile strength of about 50MPa or greater as measured according to ISO test No. 527-1:2019 at a temperature of about 23 ℃.

7. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits a tensile strength of about 50MPa or greater as measured according to ISO test No. 527-1:2019 at a temperature of about-40 ℃.

8. The fiber reinforced polymer composition of claim 1, wherein the polymer composition further comprises a flame retardant system.

9. The fiber reinforced polymer composition of claim 8, wherein the flame retardant system comprises at least one halogen-free organophosphorus flame retardant.

10. The fiber reinforced polymer composition of claim 9, wherein the organophosphorus flame retardant comprises a nitrogen-containing phosphate salt.

11. The fiber reinforced polymer composition of claim 10, wherein the phosphate salt comprises melamine phosphate, piperazine phosphate, or a combination thereof.

12. The fiber reinforced polymer composition of claim 9, wherein the organophosphorus flame retardant comprises a phosphate, a phosphonate, a phosphinate, a phosphonate amine, a phosphazene, or a combination thereof.

13. The fiber reinforced polymer composition of claim 9, wherein the organophosphorus flame retardant comprises about 50wt.% to about 99.5wt.% of the flame retardant system.

14. The fiber reinforced polymer composition of claim 1, wherein the polymer composition further comprises a stabilizer system.

15. The fiber reinforced polymer composition of claim 14, wherein the stabilizer system comprises a sterically hindered phenolic antioxidant, a phosphite antioxidant, a thioester antioxidant, or a combination thereof.

16. The fiber reinforced polymer composition of claim 14, wherein the stabilizer system comprises a UV stabilizer.

17. The fiber reinforced polymer composition of claim 1, wherein the fibers comprise glass fibers.

18. The fiber reinforced polymer composition of claim 1, wherein the fibers are spaced apart and aligned in a substantially similar direction.

19. The fiber reinforced polymer composition of claim 1, wherein the polymer composition exhibits a linear coefficient of thermal expansion of from about 10 μιη/m ℃ to about 35 μιη/m ℃.

20. An electronic module comprising a housing that receives at least one electronic component, wherein the housing comprises the polymer composition of claim 1.

21. The electronic module of claim 20, wherein the polymer composition is disposed adjacent to a metal member.

22. The electronic module of claim 21, wherein a ratio of the coefficient of linear thermal expansion of the polymer composition to the coefficient of linear thermal expansion of the metal member is from about 0.5 to about 1.5.

23. The electronic module of claim 22, wherein the metal member comprises aluminum.

24. The electronic module of claim 20, wherein the electronic component comprises an antenna element configured to transmit and receive 5G radio frequency signals.

25. The electronic module of claim 20, wherein the electronic component comprises a radio frequency sensing component.

26. The electronic module of claim 20, wherein the electronic component comprises a fiber optic assembly for receiving and transmitting pulses of light.

27. The electronic module of claim 20, wherein the electronic component comprises a camera.

Claims

5. According to claimThe fiber reinforced polymer composition of 1, wherein the polymer composition exhibits about 20kJ/m measured at a temperature of about-40 ℃ according to ISO test No. 179-1:2010 ² Or greater simply supported beams without notched impact strength.

22. The electronic module of claim 21, wherein the ratio of the coefficient of linear thermal expansion of the polymer composition to the coefficient of linear thermal expansion of the metal member is about 0.5 to about 1.5.