FLAME RETARDANT THERMOPLASTIC POLYMER COMPOSITION

Abstract

A flame retardant thermoplastic polymer composition is disclosed. The flame retardant composition may include a flame retardant system consisting of only two flame retardant components. The composition may exhibit excellent flame resistant properties at very low thicknesses. The composition may also contain a stabilizer package that dramatically improves heat aging properties.

Description

[Technical field]

[0001] Related Applications

[0001] This application is based on and claims priority to U.S. Provisional Patent Application No. 63 / 288,954, having a filing date of December 13, 2021; U.S. Provisional Patent Application No. 63 / 388,730, having a filing date of July 13, 2022; and U.S. Provisional Patent Application No. 63 / 417,543, having a filing date of October 19, 2022, all of which are incorporated by reference into this specification. [Background technology]

[0002]

[0002] In recent years, with the advent of electric vehicles and the continuous advancement of other electronic components, various electrical components such as connectors and housings have become increasingly important. For example, electric vehicles, including hybrid vehicles, generally have an electric powertrain that contains an electric propulsion source, such as thousands of lithium-ion battery cells, and at least one electric motor. The electric propulsion source provides high voltage electrical current that is fed to the motor through one or more power electronics modules. As a result, electric vehicles require the use of many electrical connectors that are used to transmit the high voltage electrical current.

[0003] In addition to their use in electric vehicles, similar electrical connectors are required in many industrial processes and systems, as well as in household electrical systems and appliances.

[0004]

[0004] Previously, conductive elements contained in connectors or other electronic components were surrounded by insulating polymers. Polyamide polymers, including glass-reinforced polyamide polymers, have been commonly used to construct electrical components due to their small size and complex geometries.

[0005]

[0005] However, polyamide compositions, especially when reinforced with glass fibers, typically do not have sufficient fire or flame resistance that may be required by various government agencies. As a result, in the past, polyamide polymers have been combined with one or more flame retardants.

[0006] For example, one common flame retardant package that has been used in the past includes a combination of diethylaluminum phosphinate (DEPAL) in combination with a melamine compound, such as melamine cyanurate or melamine polyphosphate, and zinc borate. For example, such compositions are disclosed in U.S. Pat. No. 6,255,371, U.S. Pat. No. 6,547,992, and U.S. Patent Publication No. 2006 / 0089435, all of which are incorporated herein by reference. Heretofore, the presence of all three of the above components was typically required for a polyamide composition to exhibit a V0 rating as determined according to UL94 at a thickness of 1.6 mm.

[0007]

[0007] Other flame retardant packages for use in polyamide compositions are disclosed in U.S. Patent Nos. 9,708,538 and 10,221,301, which are also incorporated herein by reference. The above references also mention the use of 9,10-dihydro-9-oxa-10 phosphaphenathrene-10-oxide (DOPO) and its derivatives. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 6,255,371 [Patent Document 2] U.S. Patent No. 6,547,992 [Patent Document 3] U.S. Patent Publication No. 2006 / 0089435 [Patent Document 4] U.S. Patent No. 9,708,538 [Patent Document 5] U.S. Patent No. 10,221,301 Summary of the Invention [Problem to be solved by the invention]

[0009]

[0008] While the flame retardant packages described above have been successful when used in previous generation products, further improvements are needed, especially as electric vehicles become more popular. In particular, there is a need for polyamide compositions that can exhibit excellent flame resistance at thinner thicknesses. There is also a need to incorporate flame retardant packages into polyamide polymers to improve the ability to melt process the polymer and mold it into various shapes and complex structures. In addition, there is a further need for flame retardant polyamide polymer compositions that also exhibit improved thermal stability. [Means for solving the problem]

[0010]

[0009] In general, the present disclosure is directed to polyamide compositions containing a flame retardant system that exhibit excellent flame resistance even at low thicknesses, have improved processing characteristics, and / or exhibit improved thermal stability.

[0011] For example, in one embodiment, the present disclosure is directed to a flame retardant polymer composition comprising a polyamide polymer, a plurality of inorganic fibers, and a flame retardant system. The flame retardant system comprises a metal phosphinate and a synergist. According to the present disclosure, the synergist comprises a melamine metal phosphate or a melamine poly(metal phosphate). In one embodiment, the flame retardant system may be present in the polymer composition in an amount greater than about 18.5% by weight. The polymer composition may also be formulated to be free of zinc borate or other similar salts. The polymer composition may be formulated to exhibit a rating of V0 when determined according to UL94 at a thickness of only 0.4 mm. Additionally, the polymer composition may be formulated to exhibit a comparative tracking index of 600 volts or higher when determined according to IC60112:2020.

[0012] In one embodiment, the metal phosphinate has the general formula (I) and / or formula (II):

[0013] [ka]

[0014] (wherein R7 and R8 are independently hydrogen or a substituted or unsubstituted, linear, branched, or cyclic, hydrocarbon group having 1 to 6 carbon atoms; R9 is a substituted or unsubstituted, linear, branched, or cyclic, C1 to C6 10 where Z is an alkylene, arylene, arylalkylene, or alkylarylene group; Z is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and / or a protonated nitrogen base; y is 1-4; n is 1-4; m is 1-4). The metal phosphinate may be present in the polymer composition in an amount of about 10% to about 20% by weight, such as about 12.5% ​​to about 16% by weight. In one embodiment, the synergist comprises melamine poly(zinc phosphate). The synergist may be present in the polymer composition in an amount of about 4% to about 12% by weight, such as about 6.5% to about 9% by weight.

[0015] In addition to the flame retardant system, the polymer composition may contain a stabilizer package that can provide various benefits and advantages. The stabilizer package may include at least a heat stabilizer. The heat stabilizer may be optionally combined with an antioxidant and / or a light stabilizer. The heat stabilizer may include, for example, a copper complex. Heat stabilizers well suited for use in the present disclosure include copper iodobis(triphenylphosphino) as one or the only component. Generally, any suitable antioxidant may be combined with the heat stabilizer. In one form, the antioxidant includes a diphosphonate. In one embodiment, the antioxidant includes a reaction product of 2,4-di-tert-butylphenol, phosphorus trichloride, and 1,1'-biphenyl. When present, the light stabilizer may include a hindered amine light stabilizer. For example, the light stabilizer may include a benzenedicarboxamide.

[0016]

[0013] The stabilizer package incorporated into the polymer composition can dramatically improve the heat aging properties of the composition. For example, the polymer composition can exhibit a decrease in Charpy notched impact resistance of less than about 50%, such as less than about 40%, after heat aging at 200°C for 1,500 hours. Similarly, the tensile strength can decrease by no more than about 50%, such as less than about 40%.

[0017]

[0014] In one embodiment, the polymer composition may also contain metal oxide particles and / or a lubricant. For example, the metal oxide particles may include silicon dioxide particles. The metal oxide particles may be present in the polymer composition in an amount of about 0.01% to about 1.5% by weight, for example, about 0.01% to about 0.3% by weight. The lubricant may include a partially saponified ester wax. For example, the lubricant may include a partially saponified ester wax of a C22 to C36 fatty acid.

[0018]

[0015] The one or more polyamides are generally present in the polymer composition in an amount of about 30% to about 70% by weight. The one or more polyamides present in the polymer composition may be one or more aliphatic polyamides, either alone or in combination with a semi-aromatic or fully aromatic polyamide. Aliphatic polyamides that may be present in the polymer composition include nylon-6, nylon-6,6, copolymers thereof, or combinations thereof.

[0019]

[0016] The inorganic fibers present in the polymer composition may include glass fibers. The glass fibers may be present in an amount of about 5% to about 50% by weight, such as about 25% to about 35% by weight. In one embodiment, the glass fibers may have an average fiber length of about 150 micrometers to about 600 micrometers.

[0020]

[0017] Any of a variety of different types of polymeric articles can be molded from the polymeric compositions of the present disclosure. The polymeric compositions are particularly well suited to be molded into components of electrical devices. The electrical device may include, for example, an electrically conductive component surrounded by a molded polymeric component formed from the polymeric compositions of the present disclosure. The electrical device may include, for example, an electrical switch, an electrical contactor, a circuit breaker, a contact rail, a battery, a battery plug board, switch gear, or a busbar. The molded polymeric component may directly surround and contact the electrically conductive component. Alternatively, the molded polymeric component may include a housing that surrounds the electrically conductive component.

[0021] In one embodiment, the electrical device may be an electrical connector including opposing walls defining a passage therebetween for receiving a contact pin. At least one of the walls may be made from a flame retardant polymer composition as described above. In one particular embodiment, the electrical connector may include a high voltage powertrain or charging connector for an electric vehicle.

[0022]

[0019] Other features and aspects of the present disclosure are discussed in more detail below.

[0020] The particular and enabling disclosure of the present disclosure is described in more detail in the remainder of the specification, including reference to the accompanying drawings. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of a high voltage charging connector that may incorporate the polymer composition of the present disclosure. [Diagram 2] FIG. 2 is a perspective view of a high voltage electrical connector including a polymeric component made in accordance with the present disclosure. [Diagram 3] FIG. 3 is a perspective view of a molded electrical housing made in accordance with the present disclosure that can be used to encapsulate a lithium ion battery. [Figure 4] FIG. 4 is a perspective view of a battery plug board that can be made in accordance with the present disclosure. [Diagram 5] FIG. 5 is a perspective view of a circuit breaker that can be made in accordance with the present disclosure. [Figure 6] FIG. 6 is a perspective view of a contact rail including a polymer component made according to the present disclosure. [Figure 7] FIG. 7 is a perspective view of an electrical switch that can be made in accordance with the present disclosure. [Figure 8] FIG. 8 is a perspective view of another embodiment of a circuit breaker that can be made in accordance with the present disclosure. [Figure 9] FIG. 9 is a perspective view of an electrical connector that can be made in accordance with the present disclosure. [Figure 10] FIG. 10 is a graphical representation of the results obtained in the examples below. [Figure 11] FIG. 11 is a graphical representation of the results obtained in the examples below. [Figure 12] FIG. 12 is a perspective assembly view of one embodiment of an electrical distribution box in which the polymer composition of the present disclosure may be employed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

[0025] Detailed Description It should be understood by those skilled in the art that the discussion of the present invention is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention.

[0026]

[0023] In general, the present disclosure is directed to a flame retardant polyamide polymer composition comprising at least one polyamide resin in combination with a flame retardant system and, optionally, reinforcing fibers. The flame retardant system may include a combination of a metal phosphinate and a synergist. The synergist may be, for example, a melamine metal phosphate or a melamine poly(metal phosphate). Among other advantages, the combination of a metal phosphinate and a synergist has been found to dramatically improve the flame resistant properties of the polymer composition at very small thicknesses without incorporating metal salts such as zinc borate into the polyamide composition. For example, the polymer composition of the present disclosure may be formulated to exhibit a V0 rating as determined according to UL94 at thicknesses of only 0.4 mm. In addition, it has been discovered that the flame retardant system of the present disclosure not only does not interfere with the melt processing properties of the polymer composition, but has actually been found to produce polyamide polymer compositions having superior melt flow and processing properties to many previously formulated flame retardant compositions. This result was completely unexpected.

[0027] In one embodiment, the polymer composition of the present disclosure may further contain a stabilizer package. The stabilizer package may include an antioxidant, a heat stabilizer, and optionally a light stabilizer. It has been found that the stabilizer package, when combined with a flame retardant system, significantly improves the heat aging characteristics of the polyamide polymer composition compared to previously used flame retardant formulations. For example, even after 1,500 hours of heat aging at 200°C, the polymer composition formulated according to the present disclosure exhibits a reduction in notched Charpy impact strength of less than 50%, such as less than about 45%, such as less than about 40%, and even less than about 35%. In addition to the impact strength, the tensile strength of the polymer composition also exhibits excellent heat aging properties. For example, after 1,500 hours of heat aging at 200°C, the tensile strength of the polymer composition decreases by less than about 50%, such as less than about 45%, such as less than about 40%, and even less than about 35%.

[0028] In addition to flame retardant properties and / or heat aging stability, the polymer compositions of the present disclosure can also exhibit excellent comparative tracking index properties. Comparative tracking index (CTI) is the maximum voltage, measured in volts, at which a material can withstand 50 drops of contaminated water without tracking. Tracking is defined as the formation of a conductive path due to electrical stress, humidity, and contamination. Comparative tracking index testing is an accelerated simulation to determine future defects that may typically cause shorts in electrical appliances that use polyamide polymer compositions as insulating materials. Comparative tracking index can be measured according to test IEC 60112:2020. The flame retardant polyamide polymer compositions of the present disclosure may be formulated to exhibit a comparative tracking index of 600 volts or higher, such as 650 volts or higher, such as 700 volts or higher.

[0029] The flame retardant polyamide compositions of the present disclosure also exhibit excellent physical and mechanical properties. For example, the polyamide compositions have a flame retardant strength of about 7 kJ / m2 when measured at 23° C. according to ISO test number 179 / 1:2010. 2 Larger, e.g., about 8 kJ / m 2 Larger, e.g., about 8.2 kJ / m 2よ For example, about 8.4 kJ / m 2 Much larger, typically around 30 kJ / m 2 It can exhibit a notched Charpy impact strength of less than 1000 nm.

[0030]

[0027] The polyamide composition may generally exhibit a tensile strength of greater than about 90 MPa, such as greater than about 95 MPa, such as greater than about 100 MPa, such as greater than about 105 MPa, such as greater than about 115 MPa, and generally less than about 200 MPa. Tensile properties may be determined according to ISO Test No. 527:2012.

[0031]

[0028] The excellent flame resistance, mechanical, and / or thermal stability properties combined with improved melt processing properties make the polymer composition of the present disclosure well suited for making any of a variety of different types of articles and parts. The polymer composition is particularly well suited for producing any of a variety of different types of electrical parts. Such parts can include high voltage power train connectors and / or charging connectors for electric vehicles and other devices that may use lithium ion batteries to obtain power. The polymer composition is also well suited for producing electrical switches, electrical contactors, circuit breakers, contact rails, batteries, battery plug boards, switch gears, and the like. The polymer composition may serve as a housing for electrical components or may be an insulating component that directly surrounds an electrical contact pin or other conductive member.

[0032]

[0029] Generally, any suitable polyamide can be incorporated into the polymer composition. The polymer composition may, for example, comprise a single type of polyamide polymer or may comprise a mixture of different polyamide polymers.

[0033]

[0030] Typically, the one or more polyamide polymers are present in the polymer composition in an amount of about 20% to about 85% by weight, including all 1% increments within that range. For example, the polymer composition may contain one or more polyamides in an amount greater than about 30% by weight, such as greater than about 40% by weight, such as greater than about 50% by weight, but generally less than about 80% by weight, such as less than about 70% by weight, such as less than about 65% by weight, such as less than about 60% by weight.

[0034]

[0031] Polyamides generally have CO-NH bonds in the main chain and are obtained by condensation of diamines and dicarboxylic acids, by ring-opening polymerization of lactams, or by self-condensation of aminocarboxylic acids. For example, polyamides may contain aliphatic repeating units obtained from aliphatic diamines, typically having 4 to 14 carbon atoms. Examples of such diamines include linear aliphatic alkylenediamines such as 1,4-tetramethylenediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, etc.; branched aliphatic alkylenediamines such as 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine, etc.; as well as combinations thereof. Of course, aromatic and / or alicyclic diamines may also be employed. Further, examples of dicarboxylic acid components include aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxy-diacetic acid, 1,3-phenylenedioxy-diacetic acid, diphenic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'-biphenyldicarboxylic acid, etc.), aliphatic dicarboxylic acids (e.g., adipic acid, sebacic acid, etc.). Examples of lactams include pyrrolidone, aminocaproic acid, caprolactam, undecane lactam, lauryllactam, etc. Similarly, examples of aminocarboxylic acids include amino fatty acids, which are compounds of the aforementioned lactams that are ring-opened with water.

[0035] In certain embodiments, "aliphatic" polyamides are employed that are formed only from aliphatic monomer units (e.g., diamine and dicarboxylic acid monomer units). Specific examples of such aliphatic polyamides include, for example, nylon-4 (poly-α-pyrrolidone), nylon-6 (polycaproamide), nylon-11 (polyundecane amide), nylon-12 (polydodecanamide), nylon-46 (polytetramethylene adipamide), nylon-66 (polyhexamethylene adipamide), nylon-610, and nylon-612. Nylon-6 and nylon-66 are particularly suitable. In one particular embodiment, for example, nylon-6 or nylon-66 can be used alone. In other embodiments, a blend of nylon-6 and nylon-66 may be employed. When such blends are employed, the weight ratio of nylon-66 to nylon-6 is typically from 1 to about 2, in some embodiments from about 1.1 to about 1.8, and in some embodiments, from about 1.2 to about 1.6.

[0036]

[0033] It is also possible to include aromatic monomer units in the polyamide so that it is semi-aromatic (containing both aliphatic and aromatic monomer units) or fully aromatic (containing only aromatic monomer units). For example, suitable semi-aromatic polyamides include poly(nonamethylene terephthalamide) (PA9T), poly(nonamethylene terephthalamide / nonamethylene decanediamide) (PA9T / 910), poly(nonamethylene terephthalamide / nonamethylene dodecanediamide) (PA9T / 912), poly(nonamethylene terephthalamide / 11-amino undecane amide) (PA9T / 11), poly(nonamethylene terephthalamide / 12-amino dodecane amide) (PA9T / 12), poly(decamethylene terephthalamide / 11-amino undecane amide) (PA10T / 11), poly(decamethylene terephthalamide / 12-amino dodecane amide) (PA10T / 12), poly(decamethylene terephthalamide / 11-amino undecane amide) (PA10T / 12), poly(decamethylene terephthalamide / 12-amino do ... diamide) (PA10T / 1010), poly(decamethylene terephthalamide / decamethylene dodecane diamide) (PA10T / 1012), poly(decamethylene terephthalamide / tetramethylene hexane diamide) (PA10T / 46), poly(decamethylene terephthalamide / caprolactam) (PA10T / 6), poly(decamethylene terephthalamide / hexamethylene hexane diamide) (PA10T / 66), poly(dodecamethylene terephthalamide / dodecamethylene dodecane diamide) (PA12T / 1212), poly(dodecamethylene terephthalamide / caprolactam) (PA12T / 6), poly(dodecamethylene terephthalamide / hexamethylene hexane diamide) (PA12T / 66), and the like can be mentioned.

[0037] In one embodiment, the polymer composition contains primarily aliphatic polyamide polymers, optionally blended with one or more semi-aromatic or fully aromatic polyamide polymers.

[0038]

[0035] The polyamides employed in the polyamide composition are typically crystalline or semi-crystalline in nature and therefore have a measurable melting temperature. The melting temperature may be relatively high so that the composition can provide a substantial degree of heat resistance to the resulting part. For example, the polyamide may have a melting temperature of about 220°C or higher, and in some embodiments, from about 240°C to about 325°C, and in some embodiments, from about 250°C to about 335°C. The polyamide may also have a relatively high glass transition temperature, such as about 30°C or higher, in some embodiments, from about 40°C or higher, and in some embodiments, from about 45°C to about 140°C. Glass transition and melting temperatures can be determined as is well known in the art using differential scanning calorimetry ("DSC"), for example, by ISO test numbers 11357-2:2013 (glass transition) and 11357-3:2011 (melting).

[0039]

[0036] In one embodiment, the polyamide polymer incorporated into the polymer composition may comprise post-industrial recycled polymer. For example, recycled polyamide polymer may be obtained from industrial fibers such as tire cords, from carpet fibers, from textile fibers, from films, from fabrics such as airbag fabrics. The recycled polyamide polymer, when incorporated into the polymer composition, is optionally combined with virgin polymer. For example, the weight ratio of recycled polyamide polymer to virgin polyamide polymer may be about 1:10 to about 10:1. For example, the amount of recycled polyamide polymer incorporated into the polymer composition may be greater than about 8 wt%, such as greater than about 10 wt%, such as greater than about 12 wt%, such as greater than about 15 wt%, such as greater than about 18 wt%, such as greater than about 20 wt%, such as greater than about 22 wt%, such as greater than about 30 wt%, such as greater than about 40 wt%, such as greater than about 50 wt%, such as greater than about 70 wt%, such as greater than about 80 wt%, such as greater than about 90 wt%, such as up to 100 wt%. The recycled polyamide is generally present in an amount less than about 90 wt%, such as less than about 70 wt%, such as less than about 50 wt%, such as less than about 45 wt%, such as less than about 35 wt%, such as less than about 30 wt%, based on the total amount of polyamide polymer present.

[0040]

[0037] In addition to one or more polyamide polymers, the flame retardant polymer composition of the present disclosure may optionally contain reinforcing fibers, which may be inorganic fibers. For example, the reinforcing or inorganic fibers may generally be present in the polymer composition in an amount greater than about 5 wt%, such as greater than about 10 wt%, such as greater than about 15 wt%, such as greater than about 20 wt%, such as greater than about 25 wt%. The reinforcing or inorganic fibers may generally be present in the polymer composition in an amount less than about 50 wt%, such as less than about 45 wt%, such as less than about 40 wt%, such as less than about 35 wt%.

[0041]

[0038] Inorganic fibers generally have a high degree of tensile strength relative to their mass. For example, the ultimate tensile strength of the fibers is typically about 1,000 to about 15,000 MPa, in some embodiments about 2,000 MPa to about 10,000 MPa, and in some embodiments about 3,000 MPa to about 6,000 MPa. High strength fibers can be formed from materials that are also inherently electrically insulating, such as, for example, glass, ceramics (e.g., alumina or silica), and the like, as well as mixtures thereof. Glass fibers are particularly suitable, such as, for example, E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass, and the like, and mixtures thereof. The inorganic fibers may have a relatively small median diameter, for example about 50 micrometers or less, in some embodiments about 0.1 to about 40 micrometers, and in some embodiments about 2 to about 20 micrometers, as determined, for example, using laser diffraction techniques in accordance with ISO 13320:2009 (e.g., using a Horiba LA-960 particle size distribution analyzer). It is believed that the small diameter of such fibers allows their length to be more easily reduced during melt blending, which can further improve the surface appearance and mechanical properties. After formation of the polymer composition, for example, the average length of the inorganic fibers may be relatively small, for example, about 10 to about 800 micrometers, in some embodiments about 100 to about 700 micrometers, and in some embodiments about 150 to about 600 micrometers. The inorganic fibers may also have a relatively high aspect ratio (average length divided by nominal diameter), such as from about 1 to about 100, in some embodiments from about 10 to about 60, and in some embodiments from about 30 to about 50.

[0042]

[0039] According to the present disclosure, the polyamide polymer composition of the present disclosure also contains a flame retardant system. In one form, the flame retardant system of the present disclosure contains only two flame retardant components, but in other embodiments, various other components may be added. A combination of excellent flame resistance properties and excellent melt processing properties can be obtained by simply incorporating a non-halogen flame retardant in combination with a synergist into the polymer composition. It is believed that constructing a flame retardant system from only two components provides numerous benefits regarding various efficiencies in the formulation of the composition, combined with excellent overall properties.

[0043] In one embodiment, the flame retardant system of the present disclosure contains a combination of a metal phosphinate and a synergist. The synergist may include an azine metal phosphate or an azine poly(metal phosphate).

[0044] The amount of the flame retardant system incorporated into the polymer composition may vary depending on the particular application and the desired results. Generally, the flame retardant system is present in the polymer composition in an amount greater than about 16% by weight, such as greater than about 18% by weight. In one embodiment, the amount of the flame retardant system incorporated into the polymer composition may be relatively large without any detrimental effect on the mechanical properties of the composition or the ability to melt process the composition. For example, the flame retardant system may be incorporated into the polymer composition in an amount greater than about 18.5% by weight, such as greater than about 19% by weight, such as greater than about 19.5% by weight, such as greater than about 20% by weight, such as greater than about 20.5% by weight, such as greater than about 21% by weight, such as greater than about 21.5% by weight, such as greater than about 22% by weight. The flame retardant system is generally present in the composition in an amount less than about 28% by weight, such as less than about 25% by weight, such as less than about 24% by weight.

[0045] As mentioned above, the flame retardant system may include a phosphinate flame retardant, such as a metal phosphinate. Such phosphinates are typically salts of phosphinic and / or diphosphinic acids, for example, those represented by the following general formula (I) and / or formula (II):

[0046] [ka]

[0047] (In the formula, R7 and R8 are independently hydrogen or a substituted or unsubstituted, linear, branched, or cyclic hydrocarbon group having 1 to 6 carbon atoms (e.g., alkyl, alkenyl, alkynyl, aralkyl, aryl, alkaryl, etc.), particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl group; R9 is a substituted or unsubstituted linear, branched, or cyclic C1-C 10 an alkylene, arylene, arylalkylene, or alkylarylene group, such as a methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, n-pentylene, n-octylene, n-dodecylene, phenylene, naphthylene, methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene, t-butylnaphthylene, phenylethylene, phenylpropylene, or phenylbutylene group; Z is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and / or a protonated nitrogen base; y is 1 to 4, preferably 1 to 2 (e.g., 1); n is 1 to 4, preferably 1 to 2 (e.g., 1); m is 1 to 4, preferably 1 to 2 (e.g., 2). It has the following.

[0048] Phosphinic acid salts can be prepared using any known technique, for example by reacting phosphinic acid with a metal carbonate, metal hydroxide, or metal oxide in aqueous solution. Particularly suitable phosphinic acid salts include, for example, metal salts of dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, methane-di(methylphosphinic acid), ethane-1,2-di(methylphosphinic acid), hexane-1,6-di(methylphosphinic acid), benzene-1,4-di(methylphosphinic acid), methylphenylphosphinic acid, diphenylphosphinic acid, hypophosphorous acid, and the like. The resulting salts are typically monomeric compounds, although polymeric phosphinic acid salts can also be formed. Particularly suitable metals for the salt include Al and Zn. For example, one particularly suitable phosphinic acid salt is zinc diethylphosphinate. Another particularly suitable phosphinic acid salt is aluminum diethylphosphinate.

[0049]

[0044] The one or more metal phosphinates may generally be present in the polymer composition in an amount greater than about 8 wt%, such as greater than about 10.5 wt%, such as greater than about 12.5 wt%, such as greater than about 13 wt%, such as greater than about 13.5 wt%, such as greater than about 14 wt%. The one or more metal phosphinates are generally present in the polymer composition in an amount less than about 20 wt%, such as less than about 18 wt%, such as less than about 16.5 wt%.

[0050]

[0045] In accordance with the present disclosure, the metal phosphinate is combined with a synergist. The synergist may include an azine metal phosphate or an azine poly(metal phosphate). In one form, the synergist may include a triazine-intercalated metal phosphate or a poly(metal phosphate). The synergist may be formed, for example, by reaction of an acidic metal phosphate with melamine. Examples of synergists particularly well suited for use in the present disclosure include melamine zinc phosphate, melamine poly(zinc phosphate), melamine magnesium phosphate, melamine poly(magnesium phosphate), melamine calcium phosphate, melamine poly(calcium phosphate), or mixtures thereof.

[0051] In one embodiment, the synergist is (melamine)2Mg(HPO4)2, (melamine)2Ca(HPO4)2, (melamine)2Zn(HPO4)2, (melamine)3Al(HPO4)3, (melamine)2Mg(P2O7), (melamine)2Ca(P2O7), (melamine)2Zn(P2O7), (melamine)3Al(P2O7). 3 / 2 may be also possible.

[0052] In one form, the synergist may be a melamine poly(metal phosphate), known as a hydrogen phosphato or pyrophosphatometalate, which has a complex anion with a tetravalent or hexavalent metal atom as the coordination site with a bidentate hydrogen phosphate or pyrophosphate ligand.

[0053] In one form the synergist may be a melamine-intercalated aluminium, zinc or magnesium salt of a condensed phosphoric acid, very particularly preferably bismelamine zincodiphosphate and / or bismelamine aluminotriphosphate.

[0054] In one form, the synergist may be aluminum phosphate, aluminum monophosphate, aluminum orthophosphate (AlPO4), aluminum orthophosphate (Al2(HPO4)3) and / or aluminum dihydrogenphosphate.

[0055] In one form, the synergist may be calcium phosphate, zinc phosphate, titanium phosphate, and / or iron phosphate. In one form, the synergist may be calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, magnesium hydrogen phosphate, titanium hydrogen phosphate (TIHC), and / or zinc hydrogen phosphate.

[0056] In one form, the synergist may be aluminum dihydrogen phosphate, magnesium dihydrogen phosphate, calcium dihydrogen phosphate, zinc dihydrogen phosphate, zinc dihydrogen phosphate dihydrate, and / or aluminum dihydrogen phosphate.

[0057] In one form, the synergist may be calcium pyrophosphate, calcium dihydrogen pyrophosphate, magnesium pyrophosphate, zinc pyrophosphate, and / or aluminum pyrophosphate.

[0058]

[0054] The synergist may generally be present in the polymer composition in an amount greater than about 4 wt%, such as greater than about 5 wt%, for example greater than about 6.5 wt%, for example greater than about 7 wt%, and generally less than about 12 wt%, for example less than about 9 wt%, for example less than about 8.5 wt%.

[0059] As mentioned above, in one embodiment, the flame retardant system may be composed of only the two components mentioned above. It has been discovered that excellent flame retardant characteristics can be obtained without the need to add other components that have been conventionally used in the past. For example, the polymer composition can be formulated to be free of metal oxides, metal hydroxides, borates, silicates, stannates, etc., that have been used in the past to increase flame retardant properties. For example, the polymer composition may be free of magnesium oxide, zinc oxide, manganese oxide, tin oxide, dihydrotalcite, hydrocalumite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, tin oxide hydrate, manganese hydroxide, zinc borate, basic zinc silicate, zinc stannate, etc.

[0060]

[0056] The polymer composition may contain only a small amount of halogen, or may not contain a halogen-based flame retardant. For example, the halogen content (i.e., bromine, fluorine, and / or chlorine) may be about 15,000 parts per million ("ppm") or less, in some embodiments about 10,000 ppm or less, in some embodiments about 5,000 ppm or less, in some embodiments about 200 ppm or less, and in some embodiments about 1 ppm to about 1,500 ppm. Nevertheless, in certain embodiments of the present invention, a halogen-based flame retardant may still be employed 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), as well as copolymers and blends and other combinations thereof.When employed, such halogen-based flame retardants typically comprise only about 10 wt.% or less of the flame retardant system, in some embodiments only about 5 wt.% or less, and in some embodiments only about 1 wt.% or less.Similarly, halogen-based flame retardants typically comprise only about 5 wt.% or less, in some embodiments only about 1 wt.% or less, and in some embodiments only about 0.5 wt.% or less of the total polymer composition.

[0061] In one form, traditional nitrogen synergists may also be excluded from the composition, for example, the composition may be free of melamine polyphosphate and / or melamine cyanurate.

[0062] In one embodiment, the polymer composition may further contain a stabilizer package. The stabilizer package has been found to dramatically improve the heat aging stability of the composition. The stabilizer package may include a heat stabilizer alone or in combination with an antioxidant and / or a light stabilizer.

[0063] The heat stabilizers contained in the stabilizer package may include copper complexes, which, in combination with either alone or in combination with an antioxidant, are believed to greatly increase the heat stability characteristics of the composition.

[0064] In one embodiment, for example, the thermal stabilizer may include iodobis(triphenylphosphino)copper.

[0061] In general, the heat stabilizer can include a copper compound, which can include a copper (I) salt, a copper (II) salt, a copper complex, or a combination thereof. For example, the copper (I) salt can be CuI, CuBr, CuCl, CuCN, CU2O, or a combination thereof, and / or the copper (II) salt can be copper acetate, copper stearate, copper sulfate, copper propionate, copper butyrate, copper lactate, copper benzoate, copper nitrate, CuO, CuCl2, or a combination thereof. In certain embodiments, the copper compound may be a copper complex containing an organic ligand, for example, an alkyl phosphine, such as a trialkyl phosphine (e.g., tris-(n-butyl)phosphine) and / or a dialkyl phosphine (e.g., 2-bis-(dimethylphosphino)-ethane); an aromatic phosphine, such as a triaryl phosphine (e.g., triphenylphosphine or a substituted triphenylphosphine) and / or a diaryl phosphine (e.g., 1,6-(bis(diphenylphosphino)) -hexane, 1,5-bis-(diphenylphosphino)-pentane, bis-(diphenylphosphino)methane, 1,2-bis-(diphenylphosphino)ethane, 1,3-bis-(diphenylphosphino)propane, 1,4-bis-(diphenylphosphino)butane, etc.; mercaptobenzimidazole; glycine; oxalates; pyridines (e.g., bipyridine); amines (e.g., ethylenediaminetetraacetate, diethylenetriamine, triethylenetetramine, etc.); acetylacetonates, etc., as well as combinations of the foregoing. Particularly suitable copper complexes for use in the heat stabilizer can include, for example, copper acetylacetonate, copper oxalate, copper EDTA, [Cu(PPh3)3X], [Cu2X(PPH3)3], [Cu(PPh3)X], [Cu(PPh3)2X], [CuX(PPh3)-2,2'-bipyridine], [CuX(PPh3)-2,2'-biquinoline)], or combinations thereof, where PPh3 is triphenylphosphine and X is CI, Br, I, CN, SCN, or 2-mercaptobenzimidazole.Similarly, other suitable complexes include 1,10-phenanthroline, o-phenylenebis(dimethylarsine), 1,2-bis(diphenylphosphino)-ethane, terpyridyl, and the like.

[0065]

[0062] Copper complexes, if employed, can be formed by reaction of copper ions (e.g. copper(I) ions) with organic ligand compounds (e.g. triphenylphosphine or mercaptobenzimidazole compounds). For example, these complexes can be obtained by reacting triphenylphosphine with copper(I) halides suspended in chloroform (G. Kosta, E. Reisenhofer and L. Stafani, J. Inorg. Nukl. Chem. 27(1965) 2581). However, it is also possible to reductively react copper(II) compounds with triphenylphosphine to obtain copper(I) adducts (FU Jardine, L. Rule, AG Vohrei, J. Chem. Soc.(A) 238-241(1970)). However, the complexes used according to the invention can also be produced by any other suitable process. Suitable copper compounds for the preparation of these complexes are copper(I) or copper(II) salts of hydrohalic acid, hydrocyanic acid, or copper salts of aliphatic carboxylic acids. Suitable examples of copper salts are copper(I) chloride, copper(I) bromide, copper(I) iodide, copper(I) cyanide, copper(II) chloride, copper(II) acetate, copper(II) stearate, and the like, as well as combinations thereof. Copper(I) iodide and copper(I) cyanide are particularly suitable.

[0066] In addition to the copper compound, the heat stabilizer may also contain a halogen-containing synergist. The copper compound and the halogen-containing synergist, when employed, are typically used in an amount to provide a copper:halogen molar ratio of about 1:1 to about 1:50, in some embodiments about 1:4 to about 1:20, in some embodiments about 1:6 to about 1:15. For example, the halogen content of the polymer composition may be about 1 ppm to about 10,000 ppm, in some embodiments about 50 ppm to about 5,000 ppm, in some embodiments about 100 ppm to about 2,000 ppm, in some embodiments about 300 ppm to about 1,500 ppm. In one embodiment, the halogen content of the polymer composition is less than about 1000 ppm, such as less than about 600 ppm, such as less than about 500 ppm, such as less than about 400 ppm.

[0067]

[0064] Halogenated synergists generally include organic halogen-containing compounds, such as aromatic and / or aliphatic halogen-containing phosphates, aromatic and / or aliphatic halogen-containing hydrocarbons, and the like, as well as combinations thereof. For example, suitable halogen-containing aliphatic phosphates can include tris(halohydrocarbyl)phosphates and / or phosphonates. Tris(bromohydrocarbyl)phosphates (brominated aliphatic phosphates) are particularly suitable. Specifically, in these compounds, there is no hydrogen atom bonded to the alkyl C atom alpha to the halogen-bonded C atom. This minimizes the extent to which dehydrohalogenation reactions can occur, thus further enhancing the stability of the polymer composition. Specific exemplary compounds are tris(3-bromo-2,2-bis(bromomethyl)propyl) phosphate, tris(dibromoneopentyl) phosphate, tris(trichloroneopentyl) phosphate, tris(bromodichloroneopentyl) phosphate, tris(chlorodibromoneopentyl) phosphate, tris(tribromoneopentyl) phosphate, or combinations thereof. Suitable halogen-containing aromatic hydrocarbons can include halogenated aromatic polymers (including oligomers), such as brominated styrene polymers (e.g., polydibromostyrene, polytribromostyrene, etc.); halogenated aromatic monomers, such as brominated phenols (e.g., tetrabromobisphenol-A), as well as combinations thereof.

[0068]

[0065] The heat stabilizer may be present in the polymer composition in an amount generally greater than about 0.08 wt%, such as greater than about 0.1 wt%, such as greater than about 0.2 wt%, such as greater than about 0.3 wt%, such as greater than about 0.4 wt%, and generally less than about 2.5 wt%, such as less than about 2 wt%, such as less than about 1.5 wt%, such as less than about 1 wt%, such as less than about 0.8 wt%. In one embodiment, the resulting copper content of the polymer composition may be from about 1 ppm to about 1,000 ppm, in some embodiments from about 3 ppm to about 200 ppm, in some embodiments from about 5 ppm to about 150 ppm, and in some embodiments from about 20 ppm to about 120 ppm.

[0069] The antioxidant, optionally present with the heat stabilizer, may be a phenolic antioxidant. In one embodiment, for example, the composition may contain a phenolic antioxidant. Examples of such phenolic antioxidants include, for example, calcium bis(ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate) (Irganox® 1425); terephthalic acid, 1,4-dithio-,S,S-bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) ester (Cyanox® 1729); triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylhydrocinnamate); namate); hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate (Irganox® 259); 1,2-bis(3,5,di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazide (Irganox® 1024); 4,4'-di-tert-octyldiphenamine (Naugalube® 438R); phosphonic acid, (3,5-di-tert-butyl-4-hydroxybenzyl)-,di 1,3,5-trimethyl-2,4,6-tris(3',5'-di-tert-butyl-4'hydroxybenzyl)benzene (Irganox® 1330); 2,4-bis(octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine (Irganox® 565); isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)benzene (Irganox® 1093); octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox® 1076); 3,7-bis(1,1,3,3-tetramethylbutyl)-10H-phenothiazine (Irganox® LO3); 2,2'-methylenebis(4-methyl-6-tert-butylphenol) monoacrylate (Irganox® 3052);2-tert-butyl-6-[1-(3-tert-butyl-2-hydroxy-5-methylphenyl)ethyl]-4-methylphenyl acrylate (Sumilizer® TM4039); 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate (Sumilizer® GS); 1,3-dihydro-2H-benzimidazole (Sumilizer® MB); 2-methyl-4,6-bis[(octylthio)methyl]phenyl N,N'-Trimethylenebis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide (Irganox® 1019); 4-n-Octadecyloxy-2,6-diphenylphenol (Irganox® 1063); 2,2'-Ethylidenebis[4,6-di-tert-butylphenol] (Irganox® 129); N,N'-Hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamamide ) (Irganox® 1098); diethyl (3,5-di-tert-butyl-4-hydroxyphenyl)phosphonate (Irganox® 1222); 4,4'-di-tert-octyldiphenylamine (Irganox® 5057); N-phenyl-1-naphthalenamine (Irganox® L05); tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-6-methylphenylthio)-5-methylphenyl]phosphite (Host anox® OSP1); zinc dinonyldithiocarbamate (Hostanox® VP-ZNCS1); 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane (Sumilizer® AG80); pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox® 1010);Ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)-propionate (Irganox® 245); 3,5-di-tert-butyl-4-hydroxytoluene (Lowinox BHT, Chemtura);

[0070] The stabilizer system may also include a phosphorus-containing antioxidant. If employed, such antioxidants typically comprise from about 2 wt.% to about 50 wt.%, in some embodiments from about 5 wt.% to about 45 wt.%, and in some embodiments from about 15 wt.% to about 35 wt.% of the stabilizer system. If employed, the weight ratio of the thermal stabilizer to the phosphorus-containing antioxidant can be selectively controlled to achieve desired properties, for example, within the range of from about 1 to about 5, in some embodiments from about 1.1 to about 4, and in some embodiments from about 1.5 to about 3.

[0071]

[0068] Phosphorus-containing antioxidants include, for example, those having the following structure: [RP(OR1)2] m (1) (In the formula, R is a mono- or polyvalent aliphatic, aromatic, or heteroaromatic organic radical, such as a cyclohexyl, phenyl, phenylene, and / or biphenyl radical; R1 is independently selected from the group consisting of the structure (II)

[0072] [ka]

[0073] or the two radicals R1 are of the structure (III)

[0074] [ka]

[0075] forming a bridging group of the formula: A is a direct bond, O, S, C1~ 18 Alkylene (straight or branched chain), or C1~ 18 is an alkylidene (straight or branched chain); R2 is independently C1~ 12 Alkyl (straight or branched chain), C1~ 12 Alkoxy or C5~ 12 is cycloalkyl; n is 0 to 5, in some embodiments 1 to 4, and in some embodiments 2 to 3; m is 1 to 4, in some embodiments 1 to 3, and in some embodiments 1 to 2 (e.g., 2). Examples of phosphonites include those having the formula:

[0076]

[0069] Particularly preferred are compounds prepared according to the preceding description by Friedel-Crafts reaction of aromatic or heteroaromatic compounds such as benzene, biphenyl or diphenyl ether with phosphorus trihalide, preferably phosphorus trichloride, in the presence of a Friedel-Crafts catalyst such as aluminum chloride, zinc chloride or iron chloride, followed by reaction with phenols which form the basis of structures (II) and (III). Mixtures of phosphites produced from excess phosphorus trihalide and from the abovementioned phenols in a specific reaction sequence are also expressly included in the present invention.

[0077] In one particular embodiment, R1 is a group of structure (II). Within this group of compounds, antioxidants of general structure (V) are particularly preferred:

[0078] [ka]

[0079] where n is as defined above. In one particular embodiment, n in formula (V) is 1, such that, for example, the antioxidant is tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene-diphosphonate.

[0080] In one embodiment, the antioxidant may be the reaction product of 2,4-di-tert-butylphenol, phosphorus trichloride, and 1,1'-biphenyl. One or more antioxidants may be present in the polymer composition generally in an amount greater than about 0.05 wt%, such as greater than about 0.08 wt%, for example greater than about 0.1 wt%, such as greater than about 0.15 wt%, for example greater than about 0.18 wt%, and generally less than about 2 wt%, such as less than about 1.5 wt%, for example less than about 1 wt%, such as less than about 0.8 wt%, for example less than about 0.5 wt%, for example less than about 0.4 wt%.

[0081] As mentioned above, the stabilizer package may optionally include a light stabilizer, which may include a hindered amine light stabilizer. Examples of light stabilizers that may be incorporated into the present disclosure include benzenedicarboxamides. Light stabilizers may also include alkyl-substituted piperidyl, piperidinyl or piperazinone compounds, or any compound derived from a substituted alkoxypiperidinyl. Other suitable HALS are those that are derivatives of 2,2,6,6-tetramethylpiperidine. Specific preferred examples of HALS include 2,2,6,6-tetramethyl-4-piperidinone, 2,2,6,6-tetramethyl-4-piperidinol, bis-(2,2,6,6-tetramethyl-4-piperidinyl)-sebacate, a mixture of esters of 2,2,6,6-tetramethyl-4-piperidinol and fatty acids, and bis-(2,2,6,6-tetramethyl-4-piperidinyl)-succinate. , Bis-(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl)-sebacate, Bis-(1,2,2,6,6-pentamethyl-4-piperidinyl)-sebacate, Tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylic acid, N-Butyl-2,2,6,6-tetramethyl-4-piperidinamine, N,N'-Bis -(2,2,6,6-tetramethyl-4-piperidyl)-hexane-1,6-diamine, ~2.2'-[(2.2.6.6-tetramethyl-4-piperidinyl)-imino]-bis-[ethanol], ~5-(2.2.6.6-tetramethyl-4-piperidinyl)-2-cyclo-undecyl-oxazole), ~2,2,4,4-tetramethyl-21-oxo-7-oxa-3.20-diazadispiro[5.1 .11.2]heneicosane-20-propionic acid dodecyl ester and 2.2.4.4 Tetramethyl-21-oxo-7;oxa-3,20-diazadispiro[5,1,11,2]-heneicosane-20-propionic acid;tetradecyl ester, ~diacetam-5 (CAS reg. no.: 76505-58-3), ~propanedioic acid, [(4-methoxyphenyl)methylene]-, bis(1,2,2,6,6-Pentamethyl-4-piperidinyl) ester, ~1,3-benzenedicarboxamide, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl), ~3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)-pyrrolidine-2,5-dione, ~formamide, N,N'-1,6-hexanediylbis[N-(2,2,6,6-tetramethyl-4-piperidinyl, ~3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidine-2,5-dione , ~1,5-dioxaspiro(5,5)undecane 3,3-dicarboxylic acid, bis(2,2,6,6-tetramethyl-4-peridinyl) ester, ~1,5-dioxaspiro(5,5)undecane 3,3-dicarboxylic acid, bis(1,2,2,6,6-pentamethyl-4-peridinyl) ester, ~bis(1,2,2,6,6-pentamethyl-4-piperidyl)(3,5-di-t-butyl-4-hydroxybenzyl)-butylpropanedioate, ~tetrakis-(1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylic acid, tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)ester, 1,2,3,4-butanetetracarboxylic acid, 1,2,3-tri(1,2,2,6,6-pentamethyl-4-piperidinyl)-4-tridecylester, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro(4,5)decane-2,4-dione, N-2,2,6,6- Tetramethyl-4-piperidinyl-N-amino-oxamide, 4-acryloyloxy-1,2,2,6,6-pentamethyl-4-piperidine, 1,5,8,12-tetrakis[2',4'-bis(1”,2”,2”,6”,6”-pentamethyl-4”-piperidinyl(butyl)amino)-1',3',5'-triazin-6'-yl]-1,5,8,12-tetraazadodecane, 1,1'-(1,2-ethane-di-yl)-bis-(3,3',5,5'-tetra-methyl-piperazinone) (Good rite 3034), propanamide, 2-methyl-N-(2,2,6,6-tetramethyl-4-piperidinyl)-2-[(2,2,6,6-tetramethyl-4-piperidinyl)amino], ~Oligomer of N-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol and succinic acid, ~Poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-s-triazine-2,4-diyl][2,2,6,6-tetramethyl-4-piperidinyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]], ~Poly[(6-morpholine-S-triazine-2.4-diyl)[(2.2.6.6-tetramethyl- 4-piperidinyl)-imino]hexamethylene-[(2.2.6.6-tetramethyl-4-piperidinyl)-imino]], ~poly[(6-morpholino-s-triazine-2.4-diyl)[1.2.2.6.6-penta-methyl-4-piperidyl)imino]-hexamethylene[(2,2,6,6 tetra-methyl-4-piperidyl)imino]], ~polymethylpropyl-3-oxy-[4(2.2.6.6-tetramethyl)-piperidinyl)]-siloxane, a-methylstyrene and n-(2.2.6.6-tetramethyl-piperidyl) Copolymers of N-stearyl-4-maleimide and N-stearyl-maleimide, ~1,2,3,4-butanetetracarboxylic acid, 8,8,8',8'-tetramethyl-2,4,8,10-tetraoxaspiro[5,5]undecane-3,9-diethanol, polymers with 1,2,2,6,6-pentamethyl-4-piperidinyl ester, ~1,2,3,4-butanetetracarboxylic acid, 8,8,8',8'-tetramethyl-2,4,8,10-tetraoxaspiro[5,5]undecane-3,9-diethanol, 2,2,6,6-tetramethyl Polymers with 4-piperidinyl esters, ~7-oxa-3,20-diazadispiro[5,1,11,2]heneicosan-21-one, oligomers of 2,2,4,4-tetramethyl-20-(oxiranylmethyl), ~1,3,5-triazine-2,4,6-triamine, N,N”-[1,2-ethanediylbis[[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazin-2-yl]imino]-3,1-propanediyl]]-bis[N,N”-dibutyl-N,N”-bis(1.2.2.6.6-pentamethyl-4-piperidinyl), ~1.3-propanediamine, N,N-1,2-ethanediylbis-, polymer with 2,4,6-trichloro-1,3,5-triazine, reaction product with N-butyl-2,2,6,6-tetramethyl-4-piperidinylamine, ~1.6-hexanediamine, N,N'-bis(2,2,6,6-tetramethyl-4piperidinyl) polymer with 2,4,6-trichloro-1,3,5-triazine, N-butyl-1-butanamine and N -butyl-2,2,6,6-tetramethyl-4-piperidinylamine, ~2,9,11,13,15,22,24,26,27,28-decaazatricyclo[21,3,1,110,14]octacosa-1(27),10,12,14(28),23,25-hexaene-12,25-diamine, N,N'-bis(1,1,3,3-tetramethylbutyl)-2,9,15,22-tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)-, ~1,1,1"-(1,3,5-triazine- 2,4,6-triyltris((cyclohexylimino)-2,1-ethanediyl)tris(3,3,5,5-tetramethylpiperazinone), ~1,1,1”-(1,3,5-triazine-2,4,6-triyltris((cyclohexylimino)-2,1-ethylenediyl)tris(3,3,4,5,5-tetramethylpiperazinone), ~1,6-hexanediamine, N,N’-bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymer with 2,4,6-trichloro-1,3,5-triazine , reaction products of 3-bromo-1-propene with n-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, oxidized, hydrogenated, ~alkene, (C20-24)-4 alpha-, polymer with maleic anhydride, reaction products with 2,2,6,6-tetramethyl-4-piperidinamine, ~N-2,2,6,6-tetramethyl-4-piperidinyl-N-amino-oxamide; 4-acryloyloxy-1,2,2,6,6-pentamethyl-4-piperidine; HALS PB-41 or mixtures thereof.

[0082] In one particular embodiment, the hindered amine light stabilizer comprises an alkyl-substituted piperidyl compound. For example, the compound can be a di- or tricarboxylic acid (ester) amide, such as N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,3-benzenedicarboxamide (Nylostab® S-EED).

[0083]

[0076] One or more light stabilizers may be present in the composition generally in an amount greater than about 0.01% by weight, such as greater than about 0.05% by weight, for example greater than about 0.08% by weight, and generally in an amount less than about 2% by weight, such as less than about 1% by weight, for example less than about 0.8% by weight, for example less than about 0.5% by weight, for example less than about 0.3% by weight, for example less than about 0.2% by weight.

[0084]

[0077] In one embodiment, the flame retardant polyamide polymer composition may also contain a lubricant. Any suitable lubricant may be incorporated into the polymer composition. In one embodiment, the lubricant may include a partially saponified ester wax. For example, the lubricant may include a partially saponified ester wax of a C22-C36 fatty acid. The fatty acid may include, for example, a montan wax. In one embodiment, the lubricant may include a 1-methyl-1,3-propanediyl ester. The lubricant may be present in the polymer composition generally in an amount greater than about 0.08 wt%, such as greater than about 0.1 wt%, such as greater than about 0.2 wt%, such as greater than about 0.3 wt%, such as greater than about 0.4 wt%, generally less than about 2.5 wt%, such as less than about 2 wt%, such as less than about 1.5 wt%, such as less than about 1 wt%, such as less than about 0.8 wt%.

[0085] Another component that may be optionally included in the polymer composition is a metal oxide particle, such as a silicon dioxide particle. The metal oxide particle or silicon dioxide particle may be present in a relatively small amount. For example, such particles may be present in the polymer composition in an amount of more than about 0.001 wt%, such as more than about 0.005 wt%, such as more than about 0.008 wt%, such as more than about 0.01 wt%, such as more than about 0.03 wt%. The particles are generally present in an amount of less than about 1.5 wt%, such as less than about 1 wt%, such as less than about 0.8 wt%, such as less than about 0.5 wt%, such as less than about 0.3 wt%, such as less than about 0.2 wt%.

[0086]

[0079] Various additional additives may further be included in the polyamide composition, examples of such additives include impact modifiers, compatibilizers, particulate fillers (e.g., mineral fillers), pigments, and / or other materials added to enhance properties or processability.

[0087]

[0080] The polyamide, inorganic fibers, flame retardant system, and other additives can be melt processed or blended together. These components can be fed separately or in combination into an extruder that includes at least one rotatably mounted screw, received in a barrel (e.g., a cylindrical barrel) defining a feed section and a melt section along the length of the screw, the feed section being disposed downstream from the feed section. Fibers can optionally be added at a location downstream from the point at which the polyamide is fed (e.g., a hopper). Optionally, a flame retardant can also be added to the extruder at a location downstream from the point at which the polyamide is fed. One or more of the extruder sections are typically heated, for example, within a temperature range of about 200°C to about 450°C, in some embodiments from about 220°C to about 350°C, in some embodiments from 250°C to about 350°C, to form the composition. The speed of the screw can be selected to achieve the desired residence time, shear rate, melt processing temperature, and the like. 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 is also about 100 sec -1 ~about 10,000 seconds -1 and in some embodiments, about 500 seconds. -1 ~about 5000 seconds -1 , in some embodiments, about 800 seconds -1 ~about 1200 seconds -1 The apparent shear rate may be in the range of 4Q / πR 3 where Q is the volumetric flow rate of the polymer melt ("m 3 / sec") and R is the radius ("m") of the capillary (e.g., extruder die) through which the molten polymer flows.

[0088] The resulting polyamide composition, regardless of the particular manner in which it is formed, can have excellent thermal properties. For example, the melt viscosity of the polyamide composition may be low enough to allow the composition to flow easily into mold cavities having small dimensions. In one particular embodiment, the polyamide composition has a melt viscosity of 1000 s. -1 The composition may have a melt viscosity of from about 400 to about 1,000 Pascal seconds ("Pa-s"), and in some embodiments from about 450 to about 900 Pa-s, and in some embodiments from about 500 to about 800 Pa-s, measured at a shear rate of 100 .mu.m. The melt viscosity may be determined according to ISO Test No. 11443:2005 at a temperature 15° C. above the melting temperature of the composition (e.g., 285° C.).

[0089]

[0082] The flame retardant polyamide polymer composition of the present disclosure can be used to produce any number of different types of molded components and parts. Examples of articles that can incorporate the polymer composition are illustrated in Figures 1-9. Referring to Figure 1, for example, a high voltage charging plug or connector 10 is illustrated. As shown, the charging plug 10 is in electrical communication with a voltage source 12 and is connected to an electric vehicle 14. The charging plug or connector 10 may include a connector portion that includes electrical pins that form an electrical connection with a high voltage circuit contained within the electric vehicle 14. A protective or insulating member extends from a base and surrounds at least a portion of the electrical pins contained within the charging plug 10. At least the base of the protective member may be comprised of the flame retardant polymer composition of the present disclosure. The flame retardant polymer composition of the present disclosure can also be used to produce various other components contained within the charging plug 10.

[0090]

[0083] Referring to Figure 2, a high voltage electrical connector is shown in its entirety 20. The connector 20 includes a first connector part 22 that is inserted into and mated with a second connector part 24. The electrical connector 20 may include a conductive part 26 surrounded by a polymer part 28. The polymer part 28 may be made from the flame retardant polymer composition of the present disclosure. As shown in Figure 2, the electrical connector 20 may have a complex shape with thin walls in certain areas. Due to the melt flow characteristics of the polymer composition of the present disclosure, the composition is well suited to forming the electrical connector 20 as shown in Figure 2 via any suitable molding process, such as injection molding.

[0091]

[0084] In one embodiment, the polymeric compositions of the present disclosure can also be used to produce housings that contain electrical components. For example, referring to FIG. 3, a portion of a battery housing 30 is shown. The battery housing 30 may include a variety of different complex shapes, all of which can be molded from the flame retardant polymeric compositions of the present disclosure. Similarly, FIG. 4 illustrates a battery plug board 40 that can also be molded from the polymeric compositions of the present disclosure. In one embodiment, the battery plug board 40 can form a portion of the battery housing and can be used to connect the battery to an electrical connector.

[0092]

[0085] In another embodiment, the flame retardant polyamide polymer composition of the present disclosure can be used to construct a circuit breaker. For example, a single switch circuit breaker 50 is shown in FIG. 5, while another embodiment of a circuit breaker 60 containing multiple switches is shown in FIG. 8. The circuit breaker contains electrical components installed in a circuit in a residential home, industrial facility, etc. The flame retardant polyamide polymer composition of the present disclosure can be used to construct the insulating components in the circuit breaker 50 or 60, can construct the housing of the circuit breaker 50 or 60, or can be used to form the switch in the circuit breaker 50 or 60.

[0093]

[0086] Referring to Figure 6, a contact rail 70 is illustrated. The contact rail 70 includes a conductive member 72. The contact rail 70 is configured to directly contact a conductive power rail. As shown in Figure 6, the contact rail 70 includes a polymer component 74 that can be made from the flame retardant polymer composition of the present disclosure.

[0094] 7, an electrical switch 80 made in accordance with the present disclosure is shown. The electrical switch 80 includes a switch 82, a housing 84, and various different electrical components 86. The switch 82 and the housing 84 may be formed from the flame resistant polyamide polymer composition of the present disclosure.

[0095]

[0088] Referring to Figure 9, another electrical component that can be constructed in accordance with the present disclosure is shown. More specifically, Figure 9 illustrates an electrical contactor 90. The electrical contactor 90 includes a housing 92 that encapsulates a polymeric component 94 that surrounds an electrically conductive component 96. The polymeric or insulating component 94 and / or the housing 92 can also be formed from the flame retardant polyamide polymer composition of the present disclosure.

[0096]

[0089] In addition to the structures shown in Figures 1-9, various other electrical components, particularly those well suited for electric vehicles, can also employ the polymer composition of the present disclosure. In one embodiment, for example, a battery system for an electric vehicle may include a battery module (e.g., a lithium ion battery module) electrically connected to a relay box. Typically, such a box may also include other electronic components, such as a main relay, a main fuse, a shunt, a heating relay, a pre-charge relay, a pre-charge resistor, and the like. The polymer composition can be used to form one or more components of the battery module, the relay box, or a combination thereof. In one embodiment, the relay box may contain a housing that includes the polymer composition. To achieve charging and discharging of the battery module, the battery system may include a positive circuit, a negative circuit, a pre-charge circuit, and a heating circuit, which are composed of various electrical components. Referring to Figure 12, for example, an embodiment of a battery system is shown that includes a main relay 3, a main fuse 4, a shunt 5, a heating relay 6, a pre-charge relay 7, and a pre-charge resistor 8. The system may also include a relay box, which in this particular embodiment is formed from a housing including a base 1 and a top cover 2. Of course, it should be understood that the box may be a unitary piece or may contain other parts. Optionally, the base 1 and / or the top cover 2 may be made from the polymer composition of the present disclosure.

[0097]

[0090] In the illustrated embodiment, the positive circuit includes a main relay 3 and a main fuse 4 connected in series. The main fuse 4 is electrically connected to the positive output terminal (not shown) of the battery module. The top cover 2 includes a first box cover 21 and a second box cover 25 in communication with each other, the first box cover 21 covering a first area and the second box cover 25 covering a second area. The first box cover 21 and the second box cover 25 are connected to form a stepped structure, and the resulting box has a regular shape. The main fuse 4 may be connected in series with the main relay 3 via a connection row 31 to form a positive circuit, whereby an input row of the positive circuit is fixedly supported on the first protrusion.

[0098]

[0091] The outer wall of the top cover 2 has grooves 23 recessed inward at the corner positions where the first box cover 21 and the second box cover 25 are connected. The groove 23 at the upper left corner of the first box cover 21 provides a path for the input row of the positive circuit, and the grooves 23 at the upper left corner and upper right corner of the second box cover 25 provide a path for the input row and the output row of the negative circuit, respectively. Furthermore, the top cover 2 and the base 1 are fixedly connected by bolts. Specifically, the diagonal positions of the grooves on the receiving side have protrusions 125 and 127, and the diagonal positions of the top cover 2 are recessed inward to form the grooves on the mounting side. Preferably, a partition plate 120 is provided on the combined protrusions and disposed between the input row of the heating circuit and the output row of the positive circuit, so as to realize the physical insulation of the heating circuit and the positive circuit and improve the reliability of the distribution box. In addition, the box further includes an adapter plug 9. The positive circuit, negative circuit, heating circuit and pre-charging circuit are all connected to an external control unit via an adapter plug 9 for communication, thereby avoiding chaotic wiring inside the box and reducing the usage of wiring harness.

[0099]

[0092] As indicated above, the flame retardant polymer composition of the present disclosure is particularly well suited for constructing electrical components, such as those operating under high pressure. In one embodiment, the polymer composition can be formulated to exhibit particularly dramatic flame retardant properties, considering that the flame retardant system contains only two components. Although not clear, it is believed that the amount of the flame retardant components, their relative weight ratios, and possibly the presence of a stabilizer package all combine together to dramatically improve flame resistance, while also unexpectedly exhibiting improved melt processing properties.

[0100] The flammability of the composition can be characterized according to Bulletin 94 of Underwriter's Laboratory, entitled "Test for Flammability of Plastic Materials, UL 94". Several ratings can be applied based on the time to extinguishment (total burn time of a set of five samples) and the ability of the composition to resist drips. The test can be applied to a variety of different samples having different thicknesses. Traditionally, the thickness has typically varied between about 0.8 mm and about 3.2 mm. In the case of the present invention, the test was performed on molded samples having a thickness of only 0.4 mm, as shown in the examples described below. Due to the thinness of the samples, the samples were first molded and then milled to a thickness of 0.4 mm. It was found that the polymeric composition of the present disclosure can still exhibit a rating of V0 even at a thickness of 0.4 mm.

[0101] [Table 1] EXAMPLES

[0102] Example 1 Test methods for the examples

[0094] Tensile modulus, tensile stress, and tensile elongation at break: Tensile properties can be tested according to ISO527:2019 (technically equivalent to ASTM D638-14). Modulus and strength measurements can be performed on the same test strip sample with a length of 80 mm, a thickness of 10 mm, and a width of 4 mm. The test temperature can be 23°C, and the test speed can be 1 or 5 mm / min.

[0103]

[0095] Flexural modulus and bending stress : Flexural properties may be tested according to ISO test number 178:2019 (technically equivalent to ASTM D790-10). The test may be performed on a support span of 64 mm. The test may be performed on the central section of an uncut ISO 3167 multipurpose bar. The test temperature may be 23°C and the test speed may be 2 mm / min.

[0104]

[0096] Charpy impact strength : Charpy properties can be tested according to ISO ISO179-1:2010) (technically equivalent to ASTM D256-10, Method B). This test can be performed using a Type 1 specimen size (80 mm length, 10 mm width, and 4 mm thickness). The specimen can be cut from the center of a multipurpose bar using a single-tooth milling machine. The test temperature may be 23°C. For "notched" impact strength, this test can be performed using a Type A notch (0.25 mm base radius) and a Type 1 specimen size (80 mm length, 10 mm width, and 4 mm thickness).

[0105]

[0097] Comparative Tracking Index ("CTI"): Comparative Tracking Index (CTI) can be determined according to the international standard IEC 60112-2020 and can provide a quantitative indication of a composition's ability to function as an electrical insulating material under wet and / or contaminated conditions. In determining the CTI rating of a composition, two electrodes are placed on a molded test specimen. A voltage difference is then established between the electrodes while a 0.1% aqueous ammonium chloride solution is dropped onto the specimen. The maximum voltage that five specimens withstand for a test period of 50 drops without producing defects is measured. Test voltages range from 100 to 600 V in increments of 25 V. The numerical value of the voltage that causes defects with the application of 50 drops of electrolyte is the "Comparative Tracking Index". This value provides an indication of the relative track resistance of the material. According to UL 746A, a nominal part thickness of 3 mm is considered representative of performance at other thicknesses.

[0106]

[0098] UL94 : The specimen is supported vertically and a flame is applied to the bottom of the specimen. The flame is applied for 10 seconds and then removed until the flame ceases, following which the flame is reapplied for another 10 seconds and then removed. Two sets of five specimens are tested. Sample size is 125mm long, 13mm wide, and 0.8mm thick, or as specified. The two sets are conditioned before and after aging. For unaged tests, each thickness is tested after conditioning for 48 hours at 23°C and 50% relative humidity. For aged tests, five samples of each thickness are tested after conditioning for 7 days at 70°C.

[0107]

[0099] A variety of different polyamide polymer compositions were compounded and tested for a variety of different properties as shown below ("x" indicates that the component is present in an amount equal to 100% by weight). After molding and drying, the above samples were tested for flame retardancy, CTI and various mechanical properties. The results are as follows:

[0108] [Table 2]

[0109]

[0100] As shown above, Samples Nos. 1 and 2 unexpectedly exhibited superior melt processing properties. Example 2

[0101] Samples Nos. 1 and 2 above were subjected to long term heat aging. Specifically, the specimens were heat aged for 1,500 hours at 200°C. The following results were obtained:

[0110] [Table 3]

[0111]

[0102] Samples Nos. 1 and 2 above were tested and compared to other formulations containing conventional flame retardants. Specifically, Samples Nos. 6 and 7 contained the same polyamide polymer but combined with an EXOLIT flame retardant package obtained from Clariant. The results are illustrated in Figures 10 and 11. As shown in Figures 10 and 11, the polymer compositions made according to the present disclosure had dramatically better heat aging characteristics.

[0112] Example 3

[0103] A variety of different flame retardant polyamide polymer compositions were formulated according to the present disclosure. In this example, each of the compositions contained different amounts of recycled post-industrial polyamide polymer. The results below demonstrate that excellent properties can be obtained even when recycled polymer is incorporated into the formulation.

[0113] The following formulations were tested with the following results:

[0114] [Table 4]

[0115] [Table 5]

[0116] [Table 6]

[0117] Example 4

[0105] Additional flame retardant polyamide polymer compositions were formulated in accordance with the present disclosure. Four different polymer composition samples were formed from nylon 6, nylon 6,6, glass fiber, a flame retardant system, a stabilizer system, a lubricant, and silica. The flame retardant system included DEPAL (aluminum phosphinate) and melamine poly(zinc phosphate). The table below lists the concentrations of each component in the samples.

[0118] [Table 7]

[0119]

[0107] After samples Nos. 12-15 were molded and dried, they were tested for various mechanical properties, the results of which are given in the table below.

[0120] [Table 8]

[0121]

[0108] Samples Nos. 12-15 were also subjected to long-term heat aging after they were molded and dried. Specifically, the specimens were heat aged for 3,000 hours at 140°C and 200°C. The results are set forth in the table below.

[0122] [Table 9]

[0123] [Table 10]

[0124] [Table 11]

[0125] [Table 12]

[0126]

[0109] These and other modifications and variations to the present invention may be implemented by those skilled in the art without departing from the spirit and scope of the present invention, which is more particularly described in the appended claims. In addition, it is to be understood that the forms of the various embodiments are interchangeable, both in whole or in part. Furthermore, those skilled in the art will appreciate that the foregoing description is merely exemplary and is not intended to limit the invention, which is further described in such appended claims. [Explanation of symbols]

[0127] 1 Base 2 Top cover 3 Main Relay 4 Main fuse 5. Shunt 6 Heating Relay 7 Pre-charging relay 8 Pre-charging resistor 9 Adapter Plug 10 High voltage charging plug or connector 12 Voltage Source 14 Electric Vehicles 20 Connector 21 First Box Cover 22 First connector part 23 Groove 24 Second connector part 25 Second Box Cover 26 Conductive parts 28 Polymer parts 30 Battery housing 31 Connection sequence 40 Battery Plug Board 50 Switch Circuit Breaker 60 Circuit Breaker 70 Contact Rail 72 Conductive materials 74 Polymer parts 80 Electric Switch 82 Switch 84 Housing 86 Electrical Components 90 Electrical Contactor 92 Housing 94 Polymer parts 96 Conductive Parts 120 Plate 125 Protrusion 127 Protrusion

Claims

1. 1. A flame retardant polymer composition comprising: a polyamide polymer; a plurality of inorganic fibers; and a flame retardant system, the flame retardant system comprising a metal phosphinate and a synergist, the synergist comprising a melamine metal phosphate or a melamine poly(metal phosphate), the flame retardant system being present in the polymer composition in an amount greater than 18.5 weight percent, the composition exhibiting a V0 rating when measured in accordance with UL94 at a thickness of 0.4 millimeters and a comparative tracking index of 600 volts or greater when measured in accordance with IEC 60112:2020.

2. The flame retardant polymer composition of claim 1 , wherein the synergist comprises melamine poly(zinc phosphate).

3. 3. The flame retardant polymer composition according to claim 1, wherein the synergist is present in the polymer composition in an amount of from 4 wt. % to 9 wt. %.

4. 10. The flame retardant polymer composition of claim 1, further comprising a stabilizer package comprising an antioxidant, a heat stabilizer, and optionally a light stabilizer, wherein the heat stabilizer comprises a copper compound.

5. 5. The flame retardant polymer composition of claim 4, wherein the copper compound comprises a copper(I) salt, a copper(II) salt, a copper complex, or a combination thereof.

6. 6. The flame retardant polymer composition of claim 4 or 5, wherein the heat stabilizer further comprises a halogen-containing synergist.

7. 5. The flame retardant polymer composition of claim 4, wherein the heat stabilizer comprises iodobis(triphenylphosphino) copper.

8. 5. The flame retardant polymer composition of claim 4, wherein the antioxidant comprises the reaction product of 2,4-di-tert-butylphenol, phosphorus trichloride, and 1,1'-biphenyl.

9. 10. The antioxidant of claim 1, wherein the antioxidant has the structure: [R-P(OR １ ) ２ ] ｍ (1) (In the formula, R is a monovalent or polyvalent aliphatic, aromatic, or heteroaromatic organic radical; R １ independently represents structure (II) 【Chemical 1】 or a compound of two radicals R １ has the structure (III) 【Chemistry 2】 forming a bridging group of the formula: A is a direct bond, O, S, C １ ~ １８ Alkylene (straight or branched chain), or C １ ~ １８ alkylidene (linear or branched); R ２ are independently １ ~ １２ Alkyl (straight or branched chain), C １ ~ １２ Alkoxy, or C ５ ~ １２ is cycloalkyl; n is 0 to 5; m is 1 to 4.

5. The flame retardant polymer composition of claim 4, comprising a phosphonate having the formula:

10. R is a cyclohexyl, phenyl, phenylene, or biphenyl radical; R １ 10. The flame retardant polymer composition of claim 9, wherein: is a group of structure (II), wherein m is 2 and n is 2-3.

11. 3. The flame retardant polymer composition of claim 1 or 2, further comprising a lubricant.

12. The flame retardant polymer composition of claim 11, wherein the lubricant comprises a partially saponified ester wax of a C22 to C36 fatty acid.

13. 3. The flame retardant polymer composition of claim 1 or 2, wherein the polyamide polymer comprises 30 wt.% to 70 wt.% of the composition, the inorganic fibers comprise 5 wt.% to 50 wt.% of the composition, and the flame retardant system comprises 19 wt.% to 27 wt.% of the composition.

14. The metal phosphinate is represented by general formula (I) and / or formula (II): 【Chemistry 3】 (In the formula, R ７ and R ８ are independently hydrogen or a substituted or unsubstituted, straight-chain, branched-chain, or cyclic hydrocarbon group having 1 to 6 carbon atoms; R ９ is a substituted or unsubstituted straight-chain, branched-chain, or cyclic C １ ~C １０ an alkylene, arylene, arylalkylene, or alkylarylene group; Z is Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and / or protonated nitrogen bases; y is 1 to 4; n is 1 to 4; m is 1 to 4.

3. The flame retardant polymer composition of claim 1, wherein

15. 2. The flame retardant polymer composition of claim 1, wherein the metal phosphinate is a metal salt of dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, methane-di(methylphosphinic acid), ethane-1,2-di(methylphosphinic acid), hexane-1,6-di(methylphosphinic acid), benzene-1,4-di(methylphosphinic acid), methylphenylphosphinic acid, diphenylphosphinic acid, or hypophosphoric acid, or a mixture thereof.

16. 3. The flame retardant polymer composition of claim 1 or 2, wherein the flame retardant system does not include zinc borate.

17. 10. The flame retardant polymer composition of claim 1, wherein the polyamide polymer is an aliphatic polyamide, the aliphatic polyamide being nylon-6, nylon-6,6, copolymers thereof, or combinations thereof.

18. 18. The flame retardant polymer composition of claim 17, wherein the aliphatic polyamide is present together with a semi-aromatic or fully aromatic polyamide.

19. 3. The flame-retardant polymer composition according to claim 1, wherein the inorganic fibers comprise glass fibers, the glass fibers being present in the polymer composition in an amount of 25 wt. % to 35 wt. %, and the glass fibers having an average fiber length of 150 micrometers to 600 micrometers.

20. 1. A flame retardant polymer composition comprising: a polyamide polymer; a plurality of inorganic fibers; and a flame retardant system, the flame retardant system comprising a metal phosphinate and a synergist, the synergist comprising a melamine metal phosphate or a melamine poly(metal phosphate), the polymer composition further comprising a stabilizer package comprising an antioxidant, a heat stabilizer, and optionally a light stabilizer, the heat stabilizer comprising a copper complex, the composition exhibiting a comparative tracking index of 600 volts or greater when measured in accordance with IEC 60112:2020.

21. 21. The flame retardant polymer composition of claim 20, wherein the synergist comprises melamine poly(zinc phosphate).

22. 22. The flame retardant polymer composition according to claim 20 or 21, wherein the synergist is present in the polymer composition in an amount of 4 wt.% to 9 wt.%, and the metal phosphinate is present in the polymer composition in an amount of 12.5 wt.% to 16 wt.%.

23. 1. A flame retardant polymer composition comprising: a polyamide polymer; a plurality of inorganic fibers; and a flame retardant system, the flame retardant system comprising a metal phosphinate and a synergist, the synergist comprising a melamine metal phosphate or a melamine poly(metal phosphate); the polymer composition further comprising a stabilizer package comprising an antioxidant, a heat stabilizer, and optionally a light stabilizer, the composition exhibiting less than about a 50% decrease in Charpy notched impact resistance and a decrease in tensile strength after heat aging at 200°C for 1500 hours.

24. 26. An electrical connector having opposing walls defining a passage therebetween for receiving a contact pin, wherein at least one of the walls comprises the flame-retardant polymer composition of any one of claims 1, 2, 4, 5, 7-10, 15, 17, 18, 20, 21, or 23.

25. 22. An electrical device comprising an electrically conductive component surrounded by a shaped polymer component, the polymer component comprising the flame retardant polymer composition of any one of claims 1, 2, 4, 5, 7-10, 15, 17, 18, 20, 21, the electrical device comprising an electrical switch, an electrical contactor, a circuit breaker, a contact rail, a battery, a battery plug board, or a switchgear.

26. A battery system for an electric vehicle, comprising a battery module and a relay box, wherein the relay box comprises the flame-retardant polymer composition according to any one of claims 1 to 21.

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