Flame retardant polyamide composition with improved glowing filament performance

Abstract

A flame retardant polyamide composition includes a polyamide, a non-halogenated phosphinate based flame retardant, an impact modifier including an olefin / acrylate copolymer / terpolymer, a flame retardant synergist, and an optional enhancer. The flame retardant polyamide composition exhibits a pass value measured by IEC 60695-2-11 for the glowing filament end product test, a pass value measured by IEC-60695-2-13: 201 for the glowing filament ignition test, a pass value measured by IEC-60695-2-13: 201 for UL94 performance at 0.8 mm (Grade V0), and an elongation at break of greater than 2.7% as measured by ISO Test No. 527: 2012.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 413,499, filed on October 5, 2022, entitled “Flame Retardant Polyamide Compositions with Improved Glow Wire Properties,” the disclosure of which is incorporated herein by reference in its entirety. field

[0002] The present disclosure relates to non-halogenated flame retardant polyamide compositions. In particular, the present disclosure relates to polyamide compositions comprising non-halogenated (halogen-free) flame retardants and impact modifiers that exhibit excellent ductility, glow-wire end product, and flammability properties. background

[0003] Polymer compositions are generally known and many have been commercially available for a long time. Conventional polymer compositions are often formed (eg, molded) into a wide variety of products.

[0004] A subset of this category of products are electrical connectors, which are commonly used in household and industrial appliances to provide connections between products and circuits, or between different components within the product itself. These electrical connectors often have complex geometries and are small in size. Many of these connectors have snap-fit ​​structures, which facilitate quick assembly (compared to nails or screws). Due to the nature and use of snap-fit ​​structures, good ductility is required to prevent breakage during the push operation.

[0005] In addition, because electrical connectors are often required to operate continuously in harsh environments at extreme temperatures and voltages, they must pass stringent safety standards to ensure consumer safety. The International Electrotechnical Commission (“IEC”) has adopted flame retardancy in multiple electrical safety standards to assess the safety of electrical end products. This integrates existing heat and fire resistance requirements for polyamide compositions and other resins used in electrical components when used as insulating materials. Applicable fire resistance and flame retardancy are described in “glow wire” standards, such as the glow wire end product test (“GWEPT”) according to IEC 60695-2-11 and the glow wire ignition test (“GWIT”) according to IEC 60695-2-13.

[0006] Conventional polyamide compositions are known to have beneficial physical properties such as high melting point, high recrystallization temperature, faster injection molding cycle time, high flow, toughness, elasticity, chemical resistance, inherent UL94 V2 flame retardancy and wear resistance. However, when these polyamide compositions are exposed to high temperatures for a long time, such as in automotive applications or electrical / electronic applications, the mechanical properties are generally degraded due to thermal oxidation of the polymer, such as heat aging. These polyamide compositions, especially those reinforced with glass fibers, generally sacrifice an acceptable degree of inherent flame resistance in exchange for CTI and mechanical properties. In addition, while the addition of heat stabilizers to polyamide compositions can improve glow-wire ignition and flammability requirements, these additional ingredients may also add other unwanted compounds / elements, thereby adversely affecting other parameters. In some cases, stabilizers may act as fuels, which is very undesirable. In many cases, additives used to benefit one performance characteristic often have an adverse effect on other performance characteristics.

[0007] Therefore, even taking into account known compositions, there remains a need for polyamide compositions that are able to meet the IEC glow wire standard without the need for halogen based flame retardants, while also exhibiting other performance characteristics, such as mechanical properties, processability or electrical properties. Overview

[0008] In some cases, the present disclosure relates to a flame retardant polyamide composition comprising (5 wt % to 85 wt %) polyamide, preferably PA-6, PA-66, PA-6,6 / 6I, PA-6I / 6T or PA-6,6 / 6T, or mixtures thereof; (0.01 wt % to 24 wt %) non-halogenated flame retardant, phosphinate-based flame retardant, preferably diethylphosphinate aluminum salt (DEPAL); at least one of: (1 wt % to 10 wt %) impact modifier, comprising an olefin / acrylate copolymer / terpolymer, optionally comprising a random terpolymer of ethylene, methyl acrylate and glycidyl methacrylate units; and (0.1 wt % to 5 wt %) flame retardant synergist, optionally a melamine-based synergist, preferably melamine polyphosphate, and optionally (less than 50 wt %) reinforcing agent, preferably reinforcing glass fibers having an average diameter greater than 10 microns; wherein the flame retardant polyamide composition exhibits a flame retardant performance as determined by IEC 6001-1 The composition may also exhibit a comparative tracking index greater than 550 volts and / or a tensile modulus greater than 3500 MPa and / or a tensile strength greater than 60 MPa as measured by IEC 60112:2003. The composition may also include additives, preferably stabilizers, colorants, lubricants, antioxidants or light stabilizers or combinations thereof. The present disclosure also relates to molded products, such as electrical connectors, comprising the flame retardant polyamide composition. Detailed Description introduce

[0009] As mentioned above, some conventional polymer (e.g., polyamide) formulations utilize heat stabilizers and flame retardants to ensure compliance with electrical safety standards. It has been found that these conventional formulations typically sacrifice mechanical properties, processability, or electrical properties to comply with electrical safety standards. And heat aging performance is generally insufficient to meet more demanding applications, including exposure to higher temperatures, such as automotive applications and electrical / electronic applications. In order to meet the glow wire standard while maintaining other performance characteristics, the traditional practice is to add heat stabilizers to the composition. However, when heat stabilizers are added to improve heat aging, such additions typically have a detrimental effect on other performance characteristics, such as processability, flame retardant ability, or electrical properties. In many cases, additives used to benefit one performance characteristic typically have an adverse effect on other performance characteristics, for example, an increase in heat aging performance can result in a loss of processability. Importantly, in order to have good snap-fit ​​capabilities, the flame retardant polyamide composition needs to exhibit good ductility (quantified by elongation at break, such as a lever that does not break); as well as low rigidity properties (quantified by mechanical modulus) and easy push / insertion.

[0010] Impact modifiers are traditionally known to be detrimental to flame and ignition properties. It is sometimes assumed that due to the ingredient chemistry, most will produce burning droplets and act as fuel, which is a detrimental effect. In addition, it is generally believed that (higher) reinforcing agent content will improve flame retardancy, at least in part because most reinforcing agents are not non-flammable. In practice, reinforcing agents are believed to form an expanding network, which helps to improve flame retardancy. Traditionally, the higher the amount of reinforcing agent, the better the flame retardancy. In fact, many flame retardant additives are designed and sold for use with higher reinforcing agent loadings, for example, greater than 25 wt%, greater than 30 wt%, greater than 35 wt%, greater than 40 wt%, greater than 45 wt%, greater than 50 wt%, greater than 60 wt%, or greater than 70 wt%.

[0011] The present inventors have now discovered that a synergistic combination of a specific non-halogenated flame retardant, a (smaller amount of) reinforcing agent and a specific impact modifier (optionally in the disclosed amounts) can meet the IEC glow wire standard without the need for a halogen-based flame retardant while maintaining other performance characteristics, such as mechanical properties (elongation at break and mechanical modulus), processability or electrical properties. It has been found that the disclosed compositions surprisingly improve flame retardancy and ignition performance. Furthermore, the disclosed (smaller amount of) reinforcing agent (e.g. glass fiber) unexpectedly provides sufficient formation of the intumescent network required to promote the non-halogenated flame retardant mechanism. The use of the disclosed impact modifier, flame retardant and / or (low) glass fiber content combination advantageously results in a synergistic combination of performance characteristics that have not been achieved before, such as GWEPT performance, ductility and mechanical properties. Specifically, the disclosed polyamide compositions exhibit excellent flame retardancy, improvements in mechanical and electrical ("CTI") properties, and reliably meet the requirements of the IEC Glow Wire Ignition Test ("GWIT") according to IEC 60695-2-13 and the Glow Wire End Product Test ("GWEPT") according to IEC 60695-2-11. Unlike conventional flame retardant polyamide compositions, the disclosed compositions do not sacrifice mechanical properties, processability, or electrical properties in order to meet electrical safety standards. Without being bound by theory, it is believed that one reason for this is that the disclosed impact modifiers contain epoxy functional groups, which are believed to have a tendency to self-react (with heat), which in turn results in a cross-linked structure that is not flammable and does not promote burning dripping during flammability testing.

[0012] The disclosed flame retardant polyamide composition comprises a combination of an impact modifier, a (low) reinforcing agent content, and a non-halogenated phosphinate-based flame retardant (and an optional melamine flame retardant synergist). Specifically, the flame retardant polyamide composition comprises a polyamide; an impact modifier, which comprises an olefin / acrylate copolymer / terpolymer; a non-halogenated phosphinate-based flame retardant; a flame retardant synergist; and an optional reinforcing agent. These components will be discussed separately below. Impact modifier

[0013] The polyamide compositions disclosed herein include one or more impact modifiers. The inventors have found that these impact modifiers work synergistically with the other components (and optionally do not adversely affect the other components). In some cases, the impact modifier can be an elastomeric or rubber material that is selected to have good interaction and compatibility with the one or more polyamides of the composition and have dispersibility between them - again, while working synergistically with the flame retardant (and optional synergist) and not adversely affecting other performance properties.

[0014] As described above, in some embodiments, the impact modifier comprises an olefin / acrylate copolymer / terpolymer backbone. In some cases, the impact modifier comprises a copolymer or terpolymer having olefin and / or acrylate units. For example, the impact modifier may comprise a random terpolymer consisting of ethylene, methyl acrylate, and glycidyl methacrylate units. It has been found that these specific impact modifiers work synergistically with the disclosed flame retardants and / or synergists, see above for discussion of glycidyl / epoxy functional groups.

[0015] In one embodiment, the impact modifier is a terpolymer including polyethylene blocks, methyl acrylate blocks, and glycidyl methacrylate blocks. Specific impact modifiers are copolymers or terpolymers having ethylene, glycidyl methacrylate, and methyl acrylate units. It has been found that combinations of specific impact modifiers work synergistically with non-halogenated flame retardants, optionally in the disclosed amounts and ratios, to provide the above-described combination of performance characteristics.

[0016] In some cases, the impact modifier includes ethylene-methacrylate-glycidyl methacrylate terpolymer, methacrylate butadiene styrene rubber, acrylate rubber, acrylonitrile-styrene-acrylate rubber, high rubber grafted acrylonitrile-butadiene-styrene, acrylate-olefin copolymer, polyolefin modifier or silicone-acrylic modifier, or a combination thereof. In some cases, the above chemical structures can be functionalized, for example, with maleic anhydride.

[0017] Some suitable commercial products are sold under the trade names It is available in the form of polymers sold by SK Chemicals. Some of them are ethylene-methacrylate-glycidyl methacrylate terpolymers including glycidyl methacrylate units (as the backbone), available under the trade name LOTADER AX8900. Others include LOTADER 4700 and LOTADER 4720, which have the same or similar backbones.

[0018] The copolymer / terpolymer may comprise 0.1 wt % to 50 wt % of acrylate (e.g., glycidyl methacrylate and / or methyl acrylate) units, e.g., 0.5 wt % to 45 wt %, 1 wt % to 40 wt %, 3 wt % to 40 wt %, 5 wt % to 35 wt %, 5 wt % to 45 wt %, 10 wt % to 35 wt %, or 15 wt % to 35 wt %, based on the total weight of the copolymer / terpolymer. In terms of upper limits, the copolymer / terpolymer may comprise less than 50 wt % of acrylate units, e.g., less than 45 wt %, less than 40 wt %, less than 35 wt %, less than 30 wt %, less than 25 wt %, or less than 20 wt %. In terms of lower limits, the copolymer / terpolymer may comprise greater than 0.1 wt % acrylate units, e.g., greater than 0.3 wt %, greater than 0.5 wt %, greater than 1 wt %, greater than 3 wt %, greater than 5 wt %, greater than 10 wt %, greater than 15 wt %, or greater than 20 wt %, based on the total weight of the copolymer / terpolymer.

[0019] The copolymer / terpolymer may comprise 30% to 80% olefin (e.g., ethylene) units, e.g., 35% to 75%, 40% to 70%, 45% to 65%, 50% to 60%, or 52.5% to 57.5% by weight, based on the total weight of the copolymer / terpolymer. In terms of upper limits, the copolymer / terpolymer may comprise less than 80% olefin units, e.g., less than 75%, less than 70%, less than 65%, less than 60%, or less than 57.5% by weight. In terms of upper limits, the copolymer / terpolymer may comprise greater than 30% olefin units, e.g., greater than 35%, greater than 40%, greater than 45%, greater than 50%, or greater than 52.5% by weight.

[0020] In some embodiments, the copolymer / terpolymer may contain 0.3 wt% to 12 wt% of glycidyl methacrylate units, such as 0.4 wt% to 11 wt%, 0.5 wt% to 10 wt%, 0.6 wt% to 9 wt%, 0.7 wt% to 8 wt%, 0.8 wt% to 7 wt%, 0.9 wt% to 6 wt%, or 1 wt% to 5 wt%, based on the total weight of the copolymer / terpolymer. In terms of upper limits, the copolymer / terpolymer may contain less than 12 wt% of glycidyl methacrylate units, such as less than 11 wt%, less than 10 wt%, less than 9 wt%, less than 8 wt%, less than 7 wt%, or less than 6 wt%. In terms of lower limits, the copolymer / terpolymer may contain greater than 0.3 wt% of glycidyl methacrylate units, such as greater than 0.4 wt%, greater than 0.5 wt%, greater than 0.6 wt%, greater than 0.7 wt%, greater than 0.8 wt%, or greater than 0.9 wt%.

[0021] The copolymer / terpolymer may comprise 5 to 35 wt % of methyl acrylate units, such as 7 to 33 wt % methyl acrylate, 9 to 31 wt % methyl acrylate, 11 to 29 wt % methyl acrylate, 13 to 27 wt % methyl acrylate, or 15 to 25 wt % methyl acrylate, based on the total weight of the copolymer / terpolymer. In terms of upper limits, the copolymer / terpolymer may comprise less than 35 wt % methyl acrylate, such as less than 33 wt % methyl acrylate, less than 31 wt % methyl acrylate, less than 29 wt % methyl acrylate, less than 27 wt % methyl acrylate, or less than 25 wt % methyl acrylate. In terms of lower limits, the copolymer / terpolymer may comprise greater than 5 wt % methyl acrylate, such as greater than 7 wt % methyl acrylate, greater than 9 wt % methyl acrylate, greater than 11 wt % methyl acrylate, greater than 13 wt % methyl acrylate, or greater than 15 wt % methyl acrylate.

[0022] The concentration of the impact modifier in the polyamide composition can be, for example, in the range of 0.01 wt % to 10 wt %, such as 0.1 wt % to 9 wt %, 1 wt % to 8 wt %, 2 wt % to 7 wt %, 3 wt % to 6 wt % or 4 wt % to 5 wt %. In terms of the upper limit, the impact modifier concentration can be less than 10 wt %, such as less than 9 wt %, less than 8 wt %, less than 7 wt %, less than 6 wt % or less than 5 wt %. In terms of the lower limit, the impact modifier concentration can be greater than 0.01 wt %, greater than 0.1 wt %, greater than 1 wt %, greater than 2 wt %, greater than 3 wt %, greater than 4 wt % or greater than 4.5 wt %. In some embodiments, the concentration of the impact modifier in the polyamide is less than 5 wt %. In some embodiments, the concentration of the impact modifier is less than 7.5 wt %. The inventors have found that the use of these amounts of impact modifiers can provide advantageous properties, such as UL94 performance.

[0023] Surprisingly, the ratio of the amount of impact modifier and non-halogenated flame retardant in the composition is particularly important for producing materials with favorable electrical and mechanical properties (e.g., strength and ductility). The weight ratio of impact modifier to non-halogenated flame retardant in the polyamide composition can be, for example, 0.05 to 2, such as 0.1 to 1.5, 0.15 to 1, 0.2 to 0.5, 0.24 to 0.6, or 0.22 to 0.4. In terms of upper limits, the weight ratio of impact modifier to non-halogenated flame retardant can be less than 2, such as less than 1.5, less than 1, less than 0.6, less than 0.5, or less than 0.4. In terms of lower limits, the weight ratio of impact modifier to non-halogenated flame retardant can be greater than 0.05, such as greater than 0.1, greater than 0.11, greater than 0.12, greater than 0.15, greater than 0.2, or greater than 0.22.

[0024] It has also been unexpectedly discovered that the ratio of the amount of impact modifier and reinforcing agent in the composition is particularly important in producing a material having a favorable combination of strength and ductility properties. Presumably, this ratio is important because a lower amount of glass fiber helps improve ductility, which in turn helps snap-fit ​​performance. The weight ratio of impact modifier to glass fiber in the polyamide composition can be, for example, 0.05 to 5, such as 0.1 to 4.0, 0.1 to 2.0, 0.2 to 2.0, 0.2 to 1.5, 0.3 to 1.0, or 0.3 to 0.9. In terms of upper limits, the weight ratio of impact modifier to glass fiber can be less than 5.0, such as less than 4.5, less than 4.0, less than 3.5, less than 3, less than 2.5, less than 2.25, less than 2, less than 1.5, less than 1.0, or less than 0.9. In terms of lower limits, the weight ratio of impact modifier to glass fiber can be greater than 0.05, eg, greater than 0.1, greater than 0.2, greater than 0.3, greater than 0.5, greater than 1, greater than 1.25, greater than 1.5, or greater than 1.75. Non-halogenated phosphinate-based flame retardants

[0025] The polyamide composition also contains a flame retardant. Typically, non-halogenated flame retardants are used because it is desirable to avoid the potential adverse environmental effects of halogenated flame retardants. The disclosed flame retardants act synergistically with the other components to provide the above-mentioned combination of performance characteristics.

[0026] Exemplary non-halogenated flame retardants include flame retardants containing phosphorus or melamine. Phosphoric acid esters are particularly suitable for use. Such compounds include, for example, alkyl and aryl esters of phosphoric acid, such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, methyl diphenyl phosphate, octyl diphenyl phosphate, tris(2-ethylhexyl) phosphate, diisopropylphenyl phosphate, tricresyl phosphate, tri(isopropylphenyl) phosphate, trinaphthyl phosphate, bisphenol A diphenyl phosphate and resorcinol diphenyl phosphate. The metal salts of these compounds are also contemplated.

[0027] Commonly used triaryl phosphates include, for example, triphenyl phosphate (TPP), toluene diphenyl phosphate, and tricresyl phosphate. Inorganic phosphate flame retardants may also be used, such as ammonium polyphosphate (which is used as an intumescent flame retardant). Hexaphenoxy cyclotriphosphazene (phenoxyphosphazene oligomers), such as Rabitle FP-100 (high purity), Rabitle FP-110 (standard grade) from Fushimi Pharmaceutical Co., exhibit high thermal stability and may be used together with these aromatic polyamides.

[0028] Exemplary flame retardants include those disclosed in US Publication Nos. 20060089435A1, 20200165416A1, US20180244899A1, and US20190153197A1.

[0029] In some embodiments, the flame retardant comprises a dialkylphosphinate (and / or a metal salt thereof, such as an aluminum salt). A specific example is the aluminum salt of diethylphosphinate, also known as DEPAL.

[0030] Combinations of the various flame retardants mentioned herein and in these references are also contemplated.

[0031] Exemplary commercial products include Clariant and Products sold under trade names such as OP1230, OP1400, OP1312, OP1380, or others.

[0032] In some embodiments, the concentration range of the non-halogenated phosphinate-based flame retardant is 0.01 wt % to 24 wt %, such as 1 wt % to 23 wt %, 2 wt % to 22 wt %, 5 wt % to 21 wt %, 6 wt % to 20 wt %, 7 wt % to 19 wt %, 8 wt % to 18 wt %, or 10 wt % to 15 wt %, based on the total weight of the polymer composition. In terms of the upper limit, the concentration of the flame retardant can be less than 24 wt %, such as less than 23 wt %, less than 22 wt %, less than 21 wt %, less than 20 wt %, less than 19 wt %, less than 18 wt %, or less than 15 wt %. In terms of the lower limit, the concentration of the flame retardant can be greater than 0.01 wt %, such as greater than 1 wt %, greater than 2 wt %, greater than 5 wt %, greater than 6 wt %, greater than 7 wt %, greater than 8 wt %, or greater than 10 wt %. Lower concentrations, such as less than 0.01 wt %, are also contemplated. Synergist

[0033] In addition to the phosphinate flame retardant, the non-halogenated flame retardant may also contain a flame retardant synergist (FR synergist). Flame retardant synergists are used to increase the effectiveness of the flame retardant. These synergists are usually used as non-halogenated charring agents and / or smoke suppressants in combination with phosphinate flame retardants. The inventors have found that the addition of these synergists can provide desirable performance characteristics, such as improved glow wire ignition test (GWIT) performance. A particularly suitable flame retardant synergist base is melamine, which contains three carbon atoms in its ring structure, substituted by amino functional groups.

[0034] Such melamine-based flame retardant synergists may include melamine phosphate, dimelamine phosphate, melamine pyrophosphate, melamine polyphosphate, melam polyphosphate, melem polyphosphate and / or cyanuramide polyphosphate. The flame retardant synergist may also include melamine condensates, such as high thermal stability nitrogen compounds, such as melam (1,3,5-triazine-2,4,6-triamine-n-(4,6-diamino-1,3,5-triazine-2-yl), melem (2,5,8-triamino-tris-triazine) and cyanuramide (poly [8-amino-1,3,4,6,7,9,9b-heptaazatriphenylene-2,5-diyl) imino).

[0035] In some embodiments, the flame retardant synergist is melamine polyphosphate, which is available from BASF as MELAPUR 200) or from Budenheim as It is commercially available under the name of 341 or 342.

[0036] In some cases, the composition includes a synergist but no impact modifier. For example, the composition includes a polyamide, a flame retardant, a synergist, and a reinforcing agent.

[0037] In some cases, the composition includes an impact modifier but no synergist. For example, the composition includes a polyamide, a flame retardant, an impact modifier, and a reinforcing agent.

[0038] In some embodiments, the concentration of the flame retardant synergist (e.g., a melamine-based flame retardant synergist) ranges from 0.01 wt % to 20 wt %, for example, 0.1 wt % to 15 wt %, 0.1 wt % to 10 wt %, 0.1 wt % to 5 wt %, 1 wt % to 9 wt %, 2 wt % to 8 wt %, 3 wt % to 7 wt %, or 4 wt % to 6 wt %, based on the total weight of the polyamide composition. In terms of upper limits, the concentration of the flame retardant may be less than 20 wt %, for example, less than 10 wt %, less than 9 wt %, less than 8 wt %, less than 7 wt %, or less than 6 wt %. In terms of lower limits, the concentration of the flame retardant may be greater than 0.01 wt %, for example, greater than 0.1 wt %, greater than 1 wt %, greater than 2 wt %, greater than 3 wt %, or greater than 4 wt %.

[0039] In some embodiments, the combined concentration of non-halogenated phosphinate-based flame retardant and (melamine-based) flame retardant synergist ranges from 0.01 wt % to 40 wt %, such as 1 wt % to 35 wt %, 2 wt % to 34 wt %, 4 wt % to 32 wt %, 5 wt % to 31 wt %, 7 wt % to 29 wt %, 8 wt % to 28 wt %, or 9 wt % to 27 wt %. In terms of upper limits, the combined concentration of phosphinate-based flame retardant and melamine-based flame retardant synergist is less than 40 wt %, such as less than 35 wt %, less than 34 wt %, less than 32 wt %, less than 31 wt %, less than 29 wt %, less than 28 wt %, or less than 27 wt %. In terms of lower limits, the combined concentration of non-halogenated phosphinate-based flame retardant and melamine-based flame retardant synergist is greater than 0.01 wt %, such as greater than 1 wt %, greater than 2 wt %, greater than 4 wt %, greater than 5 wt %, greater than 7 wt %, greater than 8 wt %, or greater than 9 wt %. Polyamide

[0040] As used herein, "polyamide" refers to a polymer having a polymer having a connection between an amino group containing one molecule and a carboxylic acid group containing another molecule as a component. In some aspects, polyamide is the component with the largest amount. For example, a polyamide containing 40% by weight of nylon 6, 30% by weight of polyethylene and 30% by weight of polypropylene is referred to as polyamide in this article because the amount of nylon 6 component is the largest. In addition, a polyamide containing 20% ​​by weight of nylon 6, 20% by weight of nylon 66, 30% by weight of polyethylene and 30% by weight of polypropylene is also referred to as polyamide in this article because the nylon 6 and nylon 66 components are the components with the largest amount in total. In some cases, polyamide is a pure polyamide and does not contain any non-polyamide units.

[0041] There are many advantages to using polyamides in commercial applications. Nylons are generally resistant to chemicals and high temperatures, resulting in superior performance over other polymers. They also have better strength, elongation, and abrasion resistance than other polymers. Nylons are also very flexible and can be used in a variety of applications.

[0042] The polyamide of the disclosed composition can vary widely and can include one polyamide polymer or two or more polyamides. Common polyamides include nylon and aramid. For example, the polyamide can include PA-4T / 4I; PA-4T / 6I; PA-5T / 5I; PA-6; PA-66; PA-6,6 / 6; PA-6,6 / 6T; PA-6,6 / 6I, PA-6I / 6T; PA-6T / 6I; PA-6T / 6I / 6; PA-6T / 6; PA-6T / 6I / 66; PA-6T / 66; PA-6T / 6I / 66; PA-6T / MPMDT (wherein MPMDT is a polyamide based on a mixture of hexamethylenediamine and 2-methylpentamethylenediamine as diamine components and terephthalic acid as diacid component); PA-6T / 66; PA-10; PA-12 ; PA610, PA612; PA-6T / 610; PA-10T / 612; PA-10T / 106; PA-6T / 612; PA-6T / 10T; PA-6T / 10I; PA-9T; PA-10T; PA-12T; PA-10T / 10I; PA-10T / 12; PA-10T / 11; PA-6T / 9T; PA-6T / 12T; PA-6T / 10T / 6I; PA-6T / 6I / 6; PA-66 / 6C; PA-6T / 61 / 12; and copolymers, blends, mixtures and / or other combinations thereof. This list is exemplary and non-limiting. Other suitable polyamides, additives and other components are disclosed in U.S. Patent Application No. 16 / 003,528.

[0043] One or more polyamide polymers in the composition may include aliphatic polyamides, such as polymerized ε-caprolactam (PA6) and polyhexamethylene adipamide (PA66) or other aliphatic nylons, polyamides with aromatic components, such as p-phenylenediamine and terephthalic acid, and copolymers, such as adipic acid and 2-methylpentanediamine and 3,5-dicarboxybenzenesulfonic acid or sulfonated isophthalic acid in the form of sodium sulfonate. Polyamides may include polymers of polyaminoundecanoic acid and bis-p-aminocyclohexylmethane and undecanoic acid. Other polyamides include poly(aminododecaneamide), polyhexamethylene sebacamide, poly(p-xylene azelaic acid), poly(m-xylene adipamide), and polyamides formed from bis(p-aminocyclohexyl)methane and azelaic acid, sebacic acid, and homologous aliphatic dicarboxylic acids. As used herein, the terms "PA6 polymer" and "PA6 polyamide polymer" also include copolymers with PA6 as the main component. As used herein, the terms "PA66 polymer" and "PA66 polyamide polymer" also include copolymers with PA66 as the main component. In some embodiments, copolymers such as PA-6,6 / 6I, PA-6I / 6T or PA-6,6 / 6T or combinations thereof are contemplated as polyamide polymers. In some cases, physical blends of these polymers, such as melt blends, are contemplated. In some cases, the polyamide polymer includes PA-6, PA-6,6, or a combination thereof. In some cases, the polyamide polymer includes PA-6,12, PA-6,10, or a combination thereof.

[0044] The polyamide composition may include a polyamide produced by ring-opening polymerization or polycondensation (including copolymerization and / or co-polycondensation) of a lactam. These polyamides may include, for example, polyamides produced by propiolactam, butyrolactam, valerolactam, and caprolactam. For example, in some embodiments, the composition may include a polyamide polymer derived from the polymerization of caprolactam.

[0045] The polyamide composition can include a combination of polyamides. By combining various polyamides, the final composition can combine the desired properties of each composition polyamide, such as mechanical properties. The combination of polyamides can include any number of known polyamides. In some embodiments, the polyamide composition includes a combination of PA6 and PA66, preferably present in an amount discussed herein. In some aspects, the polyamide composition includes 45% to 55% by weight of PA66 polyamide polymers and less than 12% by weight of PA6 polyamide polymers. The polyamide composition can also include any combination of PA6 and PA66 percentages described herein.

[0046] In the polyamide composition, the concentration of one or more polyamide polymers can be, for example, in the range of 5 % by weight to 85 % by weight, for example, in the range of 5 % by weight to 85 % by weight, in the range of 10 % by weight to 80 % by weight, in the range of 15 % by weight to 75 % by weight, in the range of 20 % by weight to 70 % by weight, in the range of 25 % by weight to 65 % by weight, in the range of 30 % by weight to 60 % by weight, in the range of 35 % by weight to 55 % by weight, or in the range of 40 % by weight to 50 % by weight. In some embodiments, the concentration of one or more polyamide polymers is in the range of 30 % by weight to 60 % by weight. With regard to the upper limit, the polyamide polymer concentration of combination can be less than 85 % by weight, for example, less than 80 % by weight, less than 75 % by weight. In some embodiments, the polyamide polymers of the present invention may be present in an amount of less than 70 wt %, less than 65 wt %, less than 60 wt %, less than 55 wt %, less than 50 wt %, less than 45 wt %, less than 40 wt %, less than 35 wt %, less than 30 wt %, less than 25 wt %, less than 20 wt %, less than 15 wt %, or less than 10 wt %. In terms of lower limits, the concentration of the combined polyamide polymers may be greater than 5 wt %, such as greater than 10 wt %, greater than 15 wt %, greater than 20 wt %, greater than 25 wt %, greater than 30 wt %, greater than 35 wt %, greater than 40 wt %, greater than 45 wt %, greater than 50 wt %, greater than 55 wt %, greater than 60 wt %, greater than 65 wt %, greater than 70 wt %, greater than 75 wt %, or greater than 80 wt %. Lower concentrations, such as less than 5 wt %, and higher concentrations, such as greater than 85 wt %, are also contemplated. In some cases, the ranges and limits disclosed for one or more polyamide polymers are applicable to PA66.

[0047] In certain aspects, one or more polyamide polymers include PA66 polymers. The concentration of the PA66 polymer in one or more polyamide polymers can be, for example, within the range of 0 wt % to 100 wt %, such as 0 wt % to 60 wt %, 10 wt % to 70 wt %, 20 wt % to 80 wt %, 30 wt % to 90 wt % or 40 wt % to 100 wt %. In some embodiments, one or more polyamide polymers include 40 wt % to 60 wt % of PA66 polymers. With regard to the upper limit, the PA66 polymer concentration in one or more polyamide polymers can be less than 100 wt %, such as less than 90 wt %, less than 80 wt %, less than 70 wt %, less than 60 wt %, less than 50 wt %, less than 40 wt %, less than 30 wt %, less than 20 wt %, or less than 10 wt %. In terms of lower limits, the concentration of PA66 polymer in the one or more polyamide polymers can be greater than 0 weight percent, for example, greater than 10 weight percent, greater than 20 weight percent, greater than 30 weight percent, greater than 40 weight percent, greater than 50 weight percent, greater than 60 weight percent, greater than 70 weight percent, greater than 80 weight percent, or greater than 90 weight percent.

[0048] In certain aspects, one or more polyamide polymers include PA6 polymers. The concentration of PA6 polymers in one or more polyamide polymers can be, for example, in the range of 0 wt % to 100 wt %, for example, 0 wt % to 60 wt %, 10 wt % to 70 wt %, 20 wt % to 80 wt %, 0.1 wt % to 25 wt %, 1 wt % to 20 wt %, 1 wt % to 15 wt %, 3 wt % to 13 wt %, 5 wt % to 15 wt %, 7 wt % to 13 wt %, 30 wt % to 90 wt % or 40 wt % to 100 wt %. In some embodiments, one or more polyamide polymers include 0 wt % to 20 wt % of PA6 polymers. In terms of upper limits, the PA6 polymer concentration in the one or more polyamide polymers can be less than 100 wt%, such as less than 90 wt%, less than 80 wt%, less than 70 wt%, less than 60 wt%, less than 50 wt%, less than 40 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 13 wt%, or less than 10 wt%. In terms of lower limits, the PA6 polymer concentration in the one or more polyamide polymers can be greater than 0 wt%, such as greater than 0.1 wt%, greater than 1 wt%, greater than 3 wt%, greater than wt%, greater than 7 wt%, greater than 10 wt%, greater than 20 wt%, greater than 30 wt%, greater than 40 wt%, greater than 50 wt%, greater than 60 wt%, greater than 70 wt%, greater than 80 wt%, or greater than 90 wt%.

[0049] The one or more polyamides each independently have a specific configuration of end groups, such as amine end groups, carboxylate end groups, and so-called inert end groups, including monocarboxylic acids, monoamines, lower dicarboxylic acids capable of forming inert imine end groups, phthalic acid and its derivatives. It has been discovered that in certain aspects, the polymer end groups can be selected to specifically interact with the impact modifier of the composition, thereby affecting dispersibility and the resulting mechanical properties.

[0050] In addition to the composition of the polyamide blend, it has been found that the relative viscosity of one or more amide polymers can provide surprising benefits in terms of performance and processing. For example, if the relative viscosity of the amide polymer is within a certain range and / or limit, productivity and tensile strength (and optional impact resilience) are improved.

[0051] In some embodiments, the RV of the polyamide composition ranges from 5 to 80, e.g., 5 to 70, 10 to 70, 15 to 65, 20 to 60, 30 to 50, 10 to 35, 10 to 20, 60 to 70, 50 to 80, 40 to 50, 30 to 60, 5 to 30, or 15 to 32. In terms of lower limits, the RV of the polyamide composition can be greater than 5, e.g., greater than 10, greater than 15, greater than 20, greater than 25, greater than 27.5, or greater than 30. In terms of upper limits, the RV of the polyamide composition can be less than 70, e.g., less than 65, less than 60, less than 50, less than 40, or less than 35.

[0052] To calculate the RV, the polyamide can be dissolved in a solvent (usually formic acid or sulfuric acid), the viscosity measured, and then compared to the viscosity of the pure solvent. This gives a unitless measurement. Solid materials as well as liquids may have a specific RV. Such measurements are well known in the art. Enhancer

[0053] Some embodiments of the flame retardant polyamide composition include a reinforcing agent. The material of the reinforcing agent is not particularly limited, and can be selected from fibers / fillers known in the art, such as glass fibers.

[0054] In certain cases, the combination of impact modifiers / flame retardants and reinforcing agents, optionally in the disclosed amounts and ratios, provide surprising, synergistic combinations of performance characteristics, such as tensile / flexural properties and impact resistance.

[0055] The reinforcing agent may include any material known for these purposes. For example, suitable reinforcing agents include silicate and silica powders, such as aluminum silicate (mullite), synthetic calcium silicate, zirconium silicate, fused silica, crystalline silica graphite, natural silica sand, etc.; boron powders, such as boron nitride powder, borosilicate powder, etc.; oxides, such as TiO 2, aluminum oxide, magnesium oxide, etc.; calcium sulfate (as its anhydrate, dihydrate or trihydrate); single crystal fibers or "whiskers", such as silicon carbide, aluminum oxide, boron carbide, iron, nickel, copper, etc.; fibers (including continuous fibers and chopped fibers), such as carbon fibers, glass fibers (such as E glass), etc.; sulfides, such as molybdenum sulfide, zinc sulfide, etc.; barium compounds, such as barium titanate, barium ferrite, barium sulfate, barite, etc.; metals and metal oxides, such as granular or fibrous aluminum, bronze, zinc, copper and nickel, etc.; flaky reinforcements, such as glass flakes, flaky silicon carbide, aluminum diboride, aluminum flakes, steel flakes, etc.; fibrous reinforcements, such as short inorganic fibers, such as those derived from materials containing aluminum silicate, aluminum oxide, magnesium oxide and semi-ferrous metals. natural reinforcing agents and reinforcing materials, such as wood flour obtained by pulverizing wood, fiber products such as cellulose, cotton, sisal, jute, starch, cork flour, lignin, peanut shells, corn, rice husks, etc.; reinforcing organic fiber reinforcing agents formed from organic polymers capable of forming fibers, such as polyetherketone, polyimide, polybenzoxazole, polyphenylene sulfide, aromatic polyamide, aromatic polyimide, polyetherimide, etc.; and additional reinforcing agents, such as mica, feldspar, smoke, magnesium aluminosilicate (fillite), quartz, quartzite, perlite, tripoli, diatomaceous earth, carbon black, etc., or a combination comprising at least one of the foregoing reinforcing agents.

[0056] The reinforcing agent can be coated with a layer of metal material to promote conductivity, or surface treated with silane to improve adhesion and dispersibility with polymer matrix resin. In addition, the reinforcing agent can be provided in the form of monofilament or multifilament fiber, and can be used alone or in combination with other types of fibers, for example, co-woven or core / sheath, side by side or matrix and fibril structure, or by other methods known to those skilled in the art of fiber manufacturing. Suitable co-woven structures include, for example, glass fiber-carbon fiber, carbon fiber-aromatic polyimide (aramid) fiber and aromatic polyimide glass fiber, etc. The fiber reinforcing agent can be provided in the form of, for example, roving, woven fiber reinforcement (such as 0-90 degree fabric, etc.); non-woven fiber reinforcement (such as continuous fiber mat, chopped fiber mat, paper towel, paper and felt, etc.); or three-dimensional reinforcement (such as braid). In some aspects, the composition does not contain layered silicate.

[0057] The concentration of the reinforcing agent in the flame retardant polyamide composition can be, for example, in the range of 5 wt % to 60 wt %, for example, in the range of 6 wt % to 50 wt %, 7 wt % to 40 wt %, 8 wt % to 30 wt % or 9 wt % to 20 wt %. As for the upper limit, the glass fiber concentration can be less than 60 wt %, for example, less than 50 wt %, less than 40 wt %, less than 30 wt %, less than 25 wt %, less than 20 wt %, less than 17.5 wt %, less than 16 wt %, less than 15 wt %, less than 12.5 wt %, less than 10 wt % or less than 8 wt %. In terms of lower limits, the glass fiber concentration can be greater than 5 wt%, such as greater than 6 wt%, greater than 7 wt%, greater than 7.5 wt%, greater than 8 wt%, greater than 8.5 wt%, greater than 9 wt%, greater than 9.5 wt%, greater than 10 wt%, greater than 11 wt%, greater than 12 wt%, greater than 12.5 wt%, greater than 13 wt%, greater than 13.5 wt%, greater than 14 wt%, or greater than 14.5 wt%. Lower concentrations, such as less than 5 wt%, and higher concentrations, such as greater than 60 wt%, are also contemplated.

[0058] As described above, in some cases, the combination of components is particularly advantageous for lower reinforcement loadings (e.g., less than 30 wt. %, less than 20 wt. %, less than 16 wt. %, or less than 15 wt. %). Advantageously, these compositions (with lower reinforcement loadings) unexpectedly provide improvements in ductility while also exhibiting the above-mentioned performance advantages.

[0059] Glass fibers are particularly suitable due to their inherent electrical insulating properties. Contemplated glass fibers include E glass, A glass, C glass, D glass, AR glass, S1 glass, S2 glass, etc., and mixtures thereof.

[0060] The glass fibers may include long fibers, for example, greater than 6 mm, greater than 7 mm, greater than 8 mm, or greater than 10 mm, short fibers, for example, less than 6 mm, less than 5 mm, or less than 3 mm, or combinations thereof. The glass fibers may be ground.

[0061] In some embodiments, the glass fibers may have a relatively small median diameter, such as about 50 microns or less, such as about 0.1 to about 40 microns, about 1 to about 20 microns, or about 2 to about 15 microns. It is believed that the small diameter of such glass fibers may make it easier to reduce their length during melt blending, which may improve mechanical properties.

[0062] The amount of glass fiber in the polyamide composition relative to the amounts of the other composition components can be selected to advantageously provide additional strength without negatively affecting material ductility.See above discussion regarding the weight ratio of impact modifier to reinforcing agent. additive

[0063] In some aspects, the composition may also include various additives, such as reinforcing agents, stabilizers, heat stabilizers, colorants, lubricants, antioxidants, light stabilizers, etc., provided that these additives do not adversely affect the desired properties of the flame retardant polyamide composition. A mixture of additives may be used. These additives may be mixed at a suitable time during the mixing of the components for forming the polyamide composition.

[0064] Antioxidants or "stabilizers" such as hindered phenols and / or secondary aromatic amines, and optionally secondary antioxidants such as phosphates and / or thioesters, may also be included as additives. Suitable antioxidant additives include, for example, organic phosphites such as tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearylpentaerythritol diphosphite, and the like; N,N'-hexane-1,6-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)); alkylated monophenols or polyphenols; alkylation reaction products of polyphenols with dienes such as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane, and the like; butylation reaction products of p-cresol or dicyclopentadiene; alkylated hydroquinone; hydroxylated thiodiphenyl ethers; alkylated Bisphenol; benzyl compound; ester of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid and monohydric alcohol or polyhydric alcohol; ester of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid and monohydric alcohol or polyhydric alcohol; ester of sulfanyl or sulfaryl compound, such as distearyl thiopropionate, dilauryl thiopropionate, ditridecyl thiodipropionate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, etc.; amide of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid, etc., or a combination comprising at least one of the above antioxidants.

[0065] Suitable commercially available antioxidants may include, for example, Irganox available from BASF and Irgafos available from BASF. Light stabilizers and / or ultraviolet (UV) absorbing additives may also be used. Suitable light stabilizer additives include, for example, benzotriazoles such as 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, and 2-hydroxy-4-n-octyloxybenzophenone, or a combination comprising at least one of the foregoing light stabilizers.

[0066] Suitable UV absorbing additives include, for example, hydroxybenzophenone; hydroxybenzotriazole; hydroxybenzotriazine; cyanoacrylate; oxalanilide; benzoxazinone; 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-phenol (CYASORB TM 5411); 2-Hydroxy-4-octyloxybenzophenone (CYASORB TM 531); 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)-phenol (CYASORB TM 1164); 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one)(CYASORB TM UV-3638); 1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane (UVINUL TM 3030); 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one); l,3-bis[(2-cyano-3,3-diphenylacryl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryl)oxy]methyl]propane; nanometer-sized inorganic materials, such as titanium dioxide, cerium dioxide and zinc oxide, all of which have a particle size of less than about 100 nanometers; or the like, or a combination comprising at least one of the foregoing ultraviolet absorbers, based on 100 parts by weight of the polymer component of the polymer composition.

[0067] Plasticizers, lubricants and / or mold release additives may also be used. There is considerable overlap between these types of materials, including, for example, phthalates, such as dioctyl-4,5-epoxy-hexahydrophthalate; tris-(octyloxycarbonylethyl) isocyanurate; tristearin; poly-α-olefins; epoxidized soybean oil; silicones, including silicone oils; esters, such as fatty acid esters such as alkyl stearates, such as methyl stearate; stearyl stearate, pentaerythritol tetrastearate, etc.; aluminum salts, such as aluminum stearate; mixtures of methyl stearate with hydrophilic and hydrophobic nonionic surfactants, including polyethylene glycol polymers, polypropylene glycol polymers and copolymers thereof, such as mixtures of methyl stearate and polyethylene-polypropylene glycol copolymers in suitable solvents; waxes, such as beeswax, montan wax, paraffin wax, etc.

[0068] Colorants such as pigments and / or dye additives may also be present. Suitable pigments include, for example, inorganic pigments such as metal oxides and mixed metal oxides such as zinc oxide, titanium dioxide, iron oxide, and the like; sulfides such as zinc sulfide, and the like; aluminates; sodium sulfate-silicates, chromates, and the like; carbon black; zinc ferrites; ultramarine; pigment brown 24; pigment red 101; pigment yellow 119; organic pigments such as azo, diazo, quinacridone, perylene, naphthalenetetracarboxylic acid, flavanone, isoindolinone, tetrachloroisoindolone, anthraquinone, anthracene, dioxazine, phthalocyanine, and azo lakes; pigment blue 60, pigment red 122, pigment red 149, pigment red 177, pigment red 179, pigment red 202, pigment violet 29, pigment blue 15, pigment green 7, pigment yellow 147, and pigment yellow 150, or a combination comprising at least one of the foregoing pigments.

[0069] When these additives are present, their content can be greater than 0.01 wt%, such as greater than 0.05 wt%, greater than 0.075 wt%, greater than 0.1 wt%, greater than 0.15 wt%, greater than 0.20 wt%, or greater than 0.25 wt%. In terms of upper limits, the content of the additive can be 4 wt% or less, 3 wt% or less, 2.75 wt% or less, 2.5 wt% or less, 2.25 wt% or less, or 2 wt% or less. In terms of ranges, the content of the additive can be 0.01 to 4 wt%, such as 0.05 to 3 wt%, 0.1 to 2.75 wt%, 0.15 to 2.5 wt%, 0.20 wt% to 2.25 wt%, or 0.25 wt% to 2 wt%.

[0070] As used herein, "greater than" and "less than" limits may also include the numbers associated therewith. In other words, "greater than" and "less than" may be interpreted as "greater than or equal to" and "less than or equal to." It is contemplated that this language may be later modified in a claim to include "or equal to." For example, "greater than 4.0" may be interpreted and later modified in a claim to "greater than or equal to 4.0."

[0071] Some components and steps disclosed herein may be considered optional. In some cases, the disclosed compositions, methods, etc. may explicitly exclude one or more of the above components or steps in this specification, for example, through claim language. The inventors contemplate this. For example, the claim language may be modified to state that the disclosed compositions, methods, flows, etc. do not utilize or include one or more of the above components or steps, for example, the flame retardant polyamide composition does not include an impact modifier. Such negative limitations are contemplated and are used herein as support for negative limitations of components, steps, and / or features. Preparation method

[0072] One or more polyamides, reinforcing agents, impact modifiers, non-halogenated flame retardants and other optional additives can be mixed and blended together to produce a polyamide composition, or can be formed in situ using appropriate reactants. The term "addition" or "combination" without further clarification is intended to cover adding the material itself to the composition or forming the material in situ in the composition. In another embodiment, two or more materials to be combined with the composition are added simultaneously through a masterbatch.

[0073] A reinforcing agent may optionally be added at a location downstream of the polyamide supply point. If desired, a flame retardant may also be added downstream of the polyamide supply point. Molded products

[0074] The present disclosure also relates to articles comprising any provided non-halogenated flame retardant polyamide compositions. The articles can be produced by, for example, conventional injection molding, extrusion molding, blow molding, compression molding, compression molding or gas-assisted molding techniques. Molding processes suitable for the disclosed compositions and articles are described in U.S. Patent Nos. 8,658,757, 4,707,513, 7,858,172 and 8,192,664, each of which is incorporated herein by reference in its entirety for all purposes. Examples of articles that can be made from the provided polyamide compositions include articles for electrical and electronic applications (such as, but not limited to, circuit breakers, wiring terminals, connectors, etc.), furniture and electrical appliance components, and wire positioning devices (such as cable ties).

[0075] In some cases, the inventors have found that the disclosed polyamide compositions are particularly suitable for manufacturing connectors, such as snap-on connectors and / or unattended devices, such as unattended household appliances, which must be able to withstand the IEC 60695-2-11 standard.

[0076] The present inventors have also discovered that the disclosed polyamide compositions are particularly suitable for use in electrical connectors, such as those used in household and industrial appliances.

[0077] The present invention may be better understood with reference to the following examples. Test Method

[0078] Tensile modulus, tensile stress and tensile elongation at break :Tensile properties can be tested according to ISO Test No. 527: 2012 (technically equivalent to ASTM D638-14). Modulus and strength measurements can be made 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.

[0079] The disclosed compositions can exhibit an elongation at break greater than 2.7%, such as greater than 2.9%, greater than 3.0%, greater than 3.2%, greater than 3.5%, greater than 3.7%, greater than 4.0%, or greater than 4.2%.

[0080] The disclosed compositions can exhibit a tensile modulus greater than 3500 MPa, e.g., greater than 3700, greater than 4000, greater than 4300, greater than 4500, greater than 4800, greater than 5000, greater than 5300, or greater than 5500.

[0081] The disclosed compositions can exhibit a tensile strength greater than 60 MPa, e.g., greater than 65, greater than 70, greater than 75, greater than 80, greater than 85, or greater than 90.

[0082] Unnotched Izod Impact Strength: Unnotched Izod performance may be tested according to ISO Test No. ISO 179-1:2010) (technically equivalent to ASTM D256-10, Method B). The test may be conducted using a Type 1 sample size (80 mm length, 10 mm width, 4 mm thickness). The sample may be cut from the center of a multipurpose bar using a single tooth milling machine. The test temperature may be 23°C.

[0083] The disclosed compositions can exhibit greater than 25 kJ / m 2 The unnotched Izod impact strength is greater than 27, greater than 30, greater than 33, greater than 35, greater than 38 or greater than 40.

[0084] Notched Izod Impact Strength: Notched Izod performance may be tested according to ASTM D256-10. The test may be conducted using a Type 1 specimen size (80 mm length, 10 mm width, 4 mm thickness). The specimen may be cut from the center of a multipurpose bar using a single tooth milling machine. The test temperature may be 23°C.

[0085] The disclosed compositions can exhibit greater than 3.5 kJ / m 2 The notched Izod impact strength is greater than 4, greater than 4.25, greater than 4.5, greater than 4.75, greater than 5.0, greater than 5.25, greater than 5.5 or greater than 5.75.

[0086] Charpy notched impact resistance: Charpy notched impact strength can be tested using a standard protocol such as ISO 179-1 (2010). The test temperature can be 23°C.

[0087] The disclosed compositions can exhibit greater than 3.5 kJ / m 2The notched Charpy impact strength is greater than 4, greater than 4.25, greater than 4.5, greater than 4.75, greater than 5.0, greater than 5.25, greater than 5.5 or greater than 5.75.

[0088] The disclosed compositions can exhibit greater than 25 kJ / m 2 The unnotched Charpy impact strength is greater than 27, greater than 30, greater than 33, greater than 35, greater than 38, greater than 40, greater than 43, greater than 45, greater than 47 or greater than 50.

[0089] Bending properties : Flexural properties, such as flexural stress, strain, and modulus, can be measured according to ISO 178. This test uses a universal testing machine and a three-point bend fixture to bend a plastic test bar to obtain the data needed to evaluate flexibility.

[0090] The disclosed compositions can exhibit a flexural stress greater than 120 MPa, e.g., greater than 125 MPa, greater than 130 MPa, greater than 131 MPa, greater than 132 MPa, greater than 133 MPa, greater than 134 MPa, greater than 135 MPa, greater than 136 MPa, greater than 137 MPa, greater than 138 MPa, greater than 139 MPa, greater than 140 MPa, or greater than 142 MPa, greater than 145 MPa, or greater than 150 MPa.

[0091] The disclosed compositions can exhibit a flexural modulus greater than 3500 MPa, 4000 MPa, greater than 4100 MPa, greater than 4200 MPa, greater than 4300 MPa, greater than 4400 MPa, greater than 4500 MPa, greater than 4600 MPa, greater than 4700 MPa, greater than 4800 MPa, greater than 4900 MPa, or greater than 5000 MPa.

[0092] Heat Deflection Temperature ("HDT") : HDT is defined as the temperature at which a sample bends 0.25 mm under a given weight. It can be measured using ISO 175 methods A (1.80 MPa), B (0.45 MPa) or C (8.00 MPa).

[0093] The disclosed compositions may exhibit a HDT greater than 150°C, e.g., greater than 160°C, greater than 170°C, greater than 180°C, greater than 190°C, greater than 200°C, greater than 210°C, greater than 220°C, greater than 230°C, greater than 240°C, or greater than 250°C.

[0094] Melting Point: The melting point can be measured according to ISO 3146 by differential scanning calorimetry (DSC).

[0095] The disclosed compositions may exhibit a melting point greater than 150°C, e.g., greater than 160°C, greater than 170°C, greater than 180°C, greater than 190°C, greater than 200°C, greater than 210°C, greater than 220°C, greater than 230°C, greater than 240°C, greater than 250°C, greater than 260°C, greater than 270°C, greater than 280°C, greater than 290°C, or greater than 300°C.

[0096] Comparative Tracking Index ("CTI"): The Comparative Tracking Index can be determined in accordance with the International Standard IEC 60112-2003 to quantitatively indicate the ability of a composition to act as an electrical insulating material under humid 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 when a 0.1% aqueous solution of ammonium chloride is dripped onto the test specimen. The maximum voltage at which five specimens do not fail during a test period of 50 drops is determined. The test voltage range is 100 to 600V, in increments of 25V. The value of the voltage at which fifty (50) drops of electrolyte cause failure is the CTI. This value provides an indication of the relative tracking resistance of the material. An equivalent method for determining CTI is ASTM D-3638-12.

[0097] UL94 : The sample is supported in a vertical position and a flame is applied to the bottom of the sample. The flame is applied for ten seconds and then removed until the flame stops, at which time the flame is applied again for ten seconds and then removed. Two groups of five samples are tested. The samples are typically tested at different widths, such as 0.4 mm, 0.8 mm, and 1.6 mm. The two groups of samples are conditioned before and after aging. For the unaged test, each thickness is tested after conditioning for 48 hours at 23°C and 50% relative humidity. For the aged test, five samples of each thickness are tested after conditioning for 7 days at 70°C. The disclosed compositions can show V0 or V1 or V2 scores.

[0098] Glow-wire ignition test: This test measures the temperature at which a composition ignites and burns for more than 5 seconds when in contact with a heated test plate. This temperature is called the glow wire ignition temperature ("GWIT") and is determined according to IEC-60695-2-13:2010 at a part thickness as described above (e.g., about 0.4 to about 3.2 millimeters). The disclosed compositions can exhibit a passing GWIT score. The disclosed compositions can exhibit a passing GWIT score at a desired temperature.

[0099] Glow Wire Final Product Testing:The test measures the final product formed from the composition in a pass / fail setting, where a glow wire at a temperature of 750°C is applied to the final product for 30 seconds. The maximum flame duration must be less than 2 seconds. The final product is measured in three different directions (x, y, and z planes). If the flame duration is less than 2 seconds, the final product obtains a "pass" in that measurement direction according to IEC-60695-2-11:2021. Parts made from the disclosed compositions can exhibit a passing GWEPT score at the desired temperature.

[0100] Glow Wire Flammability Index Test ("GWFI"): In the GWFI test, a glow wire is used at a temperature of 550 to 960°C, and the highest temperature is determined on 3 test specimens (e.g., between 4 and 60 mm) at which the afterflame time does not exceed 30 seconds and there are no burning drops in the specimens. The glow wire is applied to the test specimen, and 3 consecutive tests shall not cause ignition even during exposure to the glow wire. Ignition refers to a flame with a flame time ≥ 5 seconds. The test is performed according to IEC 60695-2-12. The disclosed compositions can exhibit a passing GWFI score at the desired temperature. Example Example 1-2: Flame retardancy and glow wire ignition test

[0101] The polyamide formulations of Examples 1 and 2 were prepared. These examples included PA66 and other components as shown in Table 1, such as PA6, reinforcement (glass fiber), mold release agent (aluminum stearate), antioxidants (Irganox 1098 and Irgafos 168), flame retardant synergist (MELAPUR 200, a melamine polyphosphate (MPP) available from BASF), impact modifier (Lotader AX8900, an ethylene / acrylate / glycidyl methacrylate terpolymer available from SK Chemicals). Each example also included a commercially available non-halogenated phosphinate-based flame retardant as described herein (organic phosphinate flame retardants, such as the Exolit product line from Clariant). Comparative Examples A, B, and C were prepared without the use of FR synergists and using different amounts of flame retardants and impact modifiers.

[0102] The above formulations were made into test specimens and tested for performance properties such as mechanical and electrical properties. The results are shown in Table 2. A GWFI score of at least 2 seconds was considered acceptable. For flameout time, the passing criteria were each individual flameout time less than 30 seconds and no burning dripping.

[0103] As shown above, Comparative Example A, which contains 21% flame retardant, does not meet the flame retardant (UL94 V1) and glow wire (GWIT) requirements. Increasing the amount of flame retardant to 24%, as shown in Comparative Examples B and C, produces adequate flame retardancy (UL94 V0) at 0.8 mm. However, GWIT performance is not improved in these examples.

[0104] However, both Example 1 and Example 2 contain a FR synergist and meet the flame retardant and glow wire requirements. Surprisingly, Example 2 also contains an impact modifier and shows significant improvements in ductility and softness without any adverse effects on UL94 and glow wire performance. Example 3-4: Amount of impact modifier

[0105] To further determine the effect of the presence of an impact modifier on flame retardancy and glow wire ignition, four formulations (Examples 3 and 4 and Comparative Examples D and E) were prepared using different amounts of Lotader AX8900 as an impact modifier, as shown below in Table 3. Each formulation contained at least some of the above additives.

[0106] The formulations were prepared into test pieces and tested for their properties as described above. The results are shown in Table 4 below.

[0107] As shown above, while all samples met the GWIT requirements, those samples containing less than 10 wt % impact modifier exhibited excellent UL94 flame retardant performance, while those containing 10+ wt % exhibited poor UL94 flame retardant performance. Example 5-6: Phosphinate flame retardant

[0108] Examples 5 and 6 were prepared using different phosphinate flame retardants (Flame Retardant A is Exolit 1312 and Flame Retardant B is Exolit 1380).

[0109] The components of the two formulations are shown in Table 5 below.

[0110] Examples 5 and 6 were prepared into test specimens and tested for mechanical, thermal and flammability properties. The results are shown in Table 6 below.

[0111] As shown in Table 6, Examples 5 and 6 performed similarly in all tests, exhibiting desirable mechanical, thermal, and flammability properties. Comparative Example FH: Phosphinic Acid-Based Flame Retardant

[0112] A similar set of samples was prepared using a phosphoric acid based flame retardant instead of the phosphinate flame retardant. The composition of the formulations is shown in Table 7 below.

[0113] The tests showed that Comparative Examples F, G and H all failed to meet the flame retardancy and glow wire requirements, as shown in Table 8 below. Example 7: GWEPT Performance

[0114] To meet the requirements of IEC 60335, all components carrying current > 0.2A and used in unattended household appliances must be able to meet the criteria of IEC 60695-2-11. As mentioned above, the test is performed by applying a glow wire with a temperature of 750°C to the test sample for 30 seconds. The maximum allowed combined flame duration is < 2 seconds.

[0115] To test the GWEPT performance, Flat Blade 24 circuit housings were molded using the compositions shown below in Table 9. The flame retardant was a non-halogenated organic phosphinate and the flame retardant synergist was melamine polyphosphate.

[0116] In order to fully characterize the GWEPT robustness, GWEPT tests were performed along the x, y and z axes of the molded parts. Five rounds of testing were performed. The results are shown in Table 10 below, where T i Indicates the ignition time; T e Indicates the time from the start of the test to the flame extinguishing; T a indicates the time the glow wire is applied; Height indicates the height of the flame; Drops indicates whether dropping of the charred portion occurs (rated as yes or no); Burn indicates whether the thin paper burns (rated as yes or no); and P / F indicates the final rating of pass or fail.

[0117] As shown above, the Flat Blade 24 circuit housing molded from the composition described herein meets the requirements of IEC 60335 for unattended household appliances carrying current greater than 0.2A. Implementation

[0118] As used hereinafter, any reference to a series of embodiments is to be understood as a reference to each of those embodiments (eg, "Embodiments 1-4" is to be understood as "Examples 1, 2, 3, or 4").

[0119] Embodiment 1: A flame retardant polyamide composition comprising a polyamide; less than 24 wt% of a non-halogenated phosphinate-based flame retardant; at least one of: an impact modifier present in an amount less than 10 wt%, the impact modifier comprising an olefin / acrylate copolymer / terpolymer, and a flame retardant synergist; and an optional reinforcing agent; wherein the flame retardant polyamide composition exhibits a pass value for the glow-wire end product test measured by IEC 60695-2-11, a pass value for the glow-wire ignition test measured by IEC-60695-2-13:201, a pass value for UL94 performance at 0.8 mm (V0 rating), and an elongation at break greater than 2.7% measured by ISO Test No. 527:2012.

[0120] Embodiment 2: The flame retardant polyamide composition of Embodiment 1, wherein the impact modifier comprises a random terpolymer composed of ethylene, methyl acrylate, and glycidyl methacrylate units.

[0121] Embodiment 3: The flame retardant polyamide composition of embodiment 1 or embodiment 2, comprising 1 wt % to 10 wt % of the impact modifier based on the total weight of the flame retardant polyamide composition.

[0122] Embodiment 4: The flame retardant polyamide composition of Embodiment 3, comprising 3 wt % to 9 wt % of the impact modifier, based on the total weight of the flame retardant polyamide composition.

[0123] Embodiment 5: The flame retardant polyamide composition of Embodiments 1-4, comprising 0.01 wt% to 24 wt% of a non-halogenated phosphinate-based flame retardant based on the total weight of the flame retardant polyamide composition.

[0124] Embodiment 6: The flame retardant polyamide composition of Embodiment 5, comprising 5 wt % to 21 wt % of a non-halogenated phosphinate-based flame retardant based on the total weight of the flame retardant polyamide composition.

[0125] Embodiment 7: The flame retardant polyamide composition of Embodiments 1-6, wherein the non-halogenated flame retardant comprises a diethylphosphinate aluminum salt (DEPAL) based flame retardant.

[0126] Embodiment 8: The flame retardant polyamide composition of Embodiments 1-7, wherein the flame retardant synergist is a melamine-based synergist.

[0127] Embodiment 9: The flame retardant composition of Embodiment 8, wherein the flame retardant synergist is melamine polyphosphate.

[0128] Embodiment 10: The flame retardant polyamide composition of Embodiments 1 to 9, comprising a flame retardant synergist, optionally in an amount of 0.1 wt % to 5 wt %.

[0129] Embodiment 11: The flame retardant polyamide composition of Embodiments 1 to 10, further comprising an additive, wherein the additive comprises a stabilizer, a colorant, a lubricant, an antioxidant or a light stabilizer or a combination thereof.

[0130] Embodiment 12: The flame retardant polyamide composition of Embodiments 1-11, comprising less than 50 wt% of a reinforcing agent, wherein the reinforcing agent is reinforcing glass fiber having an average diameter greater than 7 microns.

[0131] Embodiment 13: The flame retardant polyamide composition of embodiments 1-12 comprises 5 wt % to 85 wt % of a polyamide, including PA-6, PA-66, PA-6,6 / 6I, PA-6I / 6T, PA-6,6 / 6T, a long chain polymer such as PA12, PA610, PA612 or a mixture thereof, based on the total weight of the flame retardant polyamide composition.

[0132] Embodiment 14: The flame retardant polyamide composition of Embodiments 1-13, wherein the polyamide comprises PA-66 and PA-6.

[0133] Embodiment 15: The flame retardant polyamide composition of Embodiments 1-14, wherein the flame retardant polyamide composition exhibits a tensile modulus greater than 3500 MPa and / or a tensile strength greater than 60 MPa.

[0134] Embodiment 16: A flame retardant polyamide composition comprising: a polyamide; 5 wt% to 21 wt% of a non-halogenated diethylphosphinate aluminum salt (DEPAL) based flame retardant; 0.1 wt% to 7.5 wt% of an impact modifier comprising an olefin / acrylate copolymer / terpolymer; a flame retardant synergist comprising melamine polyphosphate, and an optional reinforcing agent; wherein the flame retardant polyamide composition exhibits a pass value for a glow wire end product test measured by IEC 60695-2-11, a pass value for a glow wire ignition test measured by IEC-60695-2-13:201, a pass value for UL94 performance at 0.8 mm (V0 rating), and an elongation at break greater than 2.7% measured by ISO Test No.527:2012.

[0135] Embodiment 17: The flame retardant polyamide composition of Embodiment 16, wherein the flame retardant polyamide composition exhibits a tensile modulus greater than 3500 MPa and / or a tensile strength greater than 60 MPa.

[0136] Embodiment 18: A molded product comprising the flame retardant polyamide composition of embodiments 1-17.

[0137] Embodiment 19: The flame retardant molded product of Embodiment 18, wherein the flame retardant molded product is an electrical connector.

[0138] Embodiment 20: The flame retardant molded product of Embodiment 19, wherein the flame retardant molded product exhibits a passing value of a glow wire end product test measured by IEC 60695-2-11.

[0139] Embodiment 21: The embodiment of embodiments 1-17, wherein the flame retardant polyamide composition exhibits a comparative tracking index greater than 250 volts as measured by IEC 60112:2003, for example, greater than 300 volts, greater than 350 volts, greater than 400 volts, greater than 500 volts, or greater than 600 volts.

Claims

1. A flame retardant polyamide composition, include: Polyamide; Less than 24% by weight of non-halogenated phosphinate-based flame retardants; At least one of the following: an impact modifier present in an amount less than 10 wt. %, the impact modifier comprising an olefin / acrylate copolymer / terpolymer, and Flame retardant synergist; as well as optional reinforcing agents; The flame retardant polyamide composition exhibits a pass value of the glow wire final product test measured by IEC 60695-2-11, a pass value of the glow wire ignition test measured by IEC-60695-2-13:201, a pass value of UL94 performance at 0.8 mm (V0 rating), and an elongation at break greater than 2.7% measured by ISO Test No. 527:2012.

2. The flame retardant polyamide composition of claim 1, wherein the impact modifier comprises a random terpolymer consisting of ethylene, methyl acrylate and glycidyl methacrylate units.

3. The flame retardant polyamide composition according to claim 1, comprising 1 to 10 wt% of the impact modifier, preferably 3 to 9 wt%, based on the total weight of the flame retardant polyamide composition.

4. The flame retardant polyamide composition according to claim 1, comprising 0.01 to 24 wt% of the non-halogenated phosphinate-based flame retardant, preferably 5 to 21 wt%, based on the total weight of the flame retardant polyamide composition.

5. The flame retardant polyamide composition of claim 1, wherein the non-halogenated flame retardant comprises a diethylphosphinate aluminum salt (DEPAL) based flame retardant.

6. The flame retardant polyamide composition according to claim 1, wherein the flame retardant synergist is a melamine based synergist, preferably melamine polyphosphate, optionally present in an amount of 0.1 wt% to 5 wt%.

7. The flame retardant polyamide composition according to claim 1, further comprising an additive, wherein the additive comprises a stabilizer, a colorant, a lubricant, an antioxidant or a light stabilizer or a combination thereof.

8. The flame retardant polyamide composition of claim 1, comprising less than 50% by weight of a reinforcing agent, wherein the reinforcing agent is reinforcing glass fiber having an average diameter greater than 7 microns.

9. The flame retardant polyamide composition according to claim 1, comprising 5 to 85 wt% of polyamide based on the total weight of the flame retardant polyamide composition, wherein the polyamide comprises PA-6, PA-66, PA-6,6 / 6I, PA-6I / 6T, PA-6,6 / 6T, a long chain polymer such as PA12, PA610, PA612 or a mixture thereof, preferably PA-66 and PA-6.

10. The flame retardant polyamide composition of claim 1, wherein the flame retardant polyamide composition exhibits a tensile modulus greater than 3500 MPa and / or a tensile strength greater than 60 MPa.

11. A flame retardant polyamide composition, include: Polyamide; 5 to 21 wt% of a non-halogenated diethylphosphinate aluminum salt (DEPAL) based flame retardant; 0.1 wt % to 7.5 wt % of an impact modifier comprising an olefin / acrylate copolymer / terpolymer; Flame retardant synergists including melamine polyphosphate, and optional reinforcing agents; The flame retardant polyamide composition exhibits a passing value of the glow wire final product test measured by IEC 60695-2-11, a passing value of the glow wire ignition test measured by IEC-60695-2-13:201, a passing value of UL94 performance at 0.8 mm (V0 rating), and an elongation at break greater than 2.7% measured by ISO Test No. 527:2012.

12. The flame retardant polyamide composition according to claim 11, wherein the flame retardant polyamide composition exhibits a tensile modulus greater than 3500 MPa and / or a tensile strength greater than 60 MPa.

13. A molded product comprising the flame retardant polyamide composition according to claim 1.

14. The flame retardant molded product according to claim 13, wherein the flame retardant molded product is an electrical connector.

15. The flame retardant molded product according to claim 14, wherein the flame retardant molded product exhibits a pass value of a glow wire end product test measured by IEC60695-2-11.

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