Polyamide elastomer with high melting point

Abstract

A process for producing a polyamide elastomer comprising feeding a salt solution having a solids content greater than or equal to 80% to a reactor having a phosphorus-containing catalyst having a phosphorus content of from 5 to 1000 parts by weight, based on the total weight of the catalyst, feeding a polyetheramine to the reactor, and reducing the pressure in the reactor upon reaching the target temperature to polymerize the salt solution and the polyetheramine to form the polyamide elastomer. The polyamide elastomers are particularly useful as cable ties and exhibit improved low temperature applications while maintaining high strength, good flame retardant rating and excellent processability.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 340,288, filed May 10, 2022, which is incorporated herein by reference in its entirety.

[0003] field

[0004] The present disclosure relates to aliphatic polyamide-based elastomers having high heat resistance, for example, above 210°C. In addition to high heat resistance, the elastomers also possess elastomeric properties such as high elongation, low compression set, and high impact resilience. In particular, the elastomers have components and / or backbones synthesized from polyamide and polyetheramines, such as diamines, triamines, tetraamines, or combinations thereof.

[0005] background

[0006] Conventional polyamides are commonly used in many applications, including cable ties. In some of these applications, the polyamides may be exposed to low temperatures, such as -40°C or lower. It is known that polyamides undergo a number of irreversible chemical and physical changes when exposed to such low temperatures, which manifest themselves in adverse properties. For example, the polyamides may become brittle, leading to breakage problems.

[0007] Even for cable ties designed for colder temperatures, many have failure rates of 10% or more at low temperatures. For example, conventional nylon cable ties exhibit a low-temperature failure rate of approximately 15-20%.

[0008] However, many of these conventional nylons, such as nylon 6,6, are known to offer desirable advantages such as high tensile strength, desirable high flammability ratings, low injection pressure / high flow, and fast cycle times (i.e., <12 seconds). Traditional strategies for toughening these conventional nylons, such as impact modification with maleated polyethylene materials, can provide the desired low-temperature and dry properties but can negatively impact flammability and strength properties.

[0009] Therefore, there is a need in the art for a polyamide composition that maintains the high strength and other beneficial properties associated with conventional nylons while providing improved dry and low temperature performance. The present disclosure addresses this need.

[0010] Overview

[0011] In general, the present disclosure relates to a polyamide elastomer comprising a polyetheramine, comprising a polyetheramine, such as a diamine, a triamine, a tetraamine, or a combination thereof, and an aliphatic polyamide. The polyamide elastomer is suitable for use as a concentrate added to a base polyamide to form a polyamide composition. Thus, in some embodiments, the present disclosure relates to a polyamide composition, i.e., a polyamide elastomer, comprising a base polyamide (e.g., polyamide 6,6 homopolymer) and an elastomer concentrate comprising 20-80% by weight of an elastomeric aliphatic polyether having a molecular weight of 400-4000 g / mol (e.g., polytetramethyl ether diamine or polyethylene oxide diamine); and 80-20% by weight of a concentrate polyamide (e.g., PA66 / 610 or PA66 / 6). In one embodiment, an article made from the polyamide composition comprises a cable tie.

[0012] In one embodiment, a method for producing a polyamide elastomer is provided, comprising feeding a salt solution having a solids content of greater than or equal to 80% to a reactor having a phosphorus-containing catalyst having a phosphorus content of 5 to 1000 parts per million (ppm), e.g., 10 to 100 ppm, based on the total weight of the catalyst, preferably at a temperature, feeding a polyetheramine comprising a polyetherdiamine, a triamine, a tetraamine, or a combination thereof to the reactor, and once a target temperature in the range of 240° C. to 260° C. is reached, reducing the pressure in the reactor to polymerize the salt solution and the polyetheramine to form the polyamide elastomer. In one embodiment, the pressure in the reactor is reduced to less than or equal to 2 atm, preferably 0.1 atm to 1 atm. In one embodiment, the polyetherdiamine preferably contains at least 70% primary amines, based on the total number of amines in the elastomeric aliphatic polyetherdiamine.

[0013] In another embodiment, a method is provided of feeding a salt solution into a reactor having a phosphorus-containing catalyst having a phosphorus content of 5 to 1000 parts per million based on the total weight of the catalyst; reducing the water content in the reactor, feeding a polyetheramine comprising a polyetherdiamine, triamine, tetraamine, or a combination thereof into the reactor after the water content has been reduced, and reducing the pressure in the reactor once a target temperature in the range of 240° C. to 260° C. has been reached to polymerize the salt solution and the polyetheramine to form a polyamide elastomer. In one embodiment, the polymerization step involves a high pressure cycle followed by a reduction in pressure, and post-polymerization (molecular weight building) at a reduced pressure, for example, less than or equal to 2 atm, preferably 0.1 atm to 1 atm, and a temperature of 240° C. to 260° C.

[0014] Details

[0015] As described above, conventional polyamide compositions, although exhibiting some desirable properties, have disadvantages, such as poor low temperature performance.

[0016] The present disclosure relates to polyamide compositions comprising a base polyamide and an elastomer concentrate that provide significant improvements in performance, particularly when used in articles for low-temperature applications, such as cable ties. For example, when the polyamide composition is formed into a cable tie, it exhibits a cable tie installation performance failure rate of less than 15%, or even less than 10%, when measured at low temperatures.

[0017] It has now been discovered that the use of an elastomer concentrate (along with a base polymer) has been shown to improve dry and low-temperature performance while synergistically maintaining the high strength properties of known polyamides, such as PA66. Without being bound by theory, it is speculated that the elastomeric copolymer acts as a molecular-level energy dampener, thereby providing improved dry toughness and maintaining a mobile phase (low glass transition phase) at low temperatures (i.e., below 0°C, particularly -40°C to 0°C). As a result, the disclosed polymer compositions provide an unexpected combination of performance characteristics that have not been previously achieved, such as low-temperature failure rate, tensile strength, and V-2 flammability rating.

[0018] Polyamide composition

[0019] The disclosed polyamide composition comprises a base polyamide (first polyamide) and an elastomer concentrate comprising a polyetheramine and a concentrate polyamide (second polyamide). A method for producing the elastomer concentrate is disclosed herein that is efficient and commercially viable for producing the elastomer concentrate. Additional polyamides may also be included in the polyamide composition.

[0020] Basic polyamide

[0021] The first polyamide may include various natural and artificial polyamides. Common polyamides include nylon and aromatic polyamides. The first polyamide may include aliphatic polyamides, such as polymerized ε-caprolactam (PA6) and polyhexamethylene adipamide (PA66) or other aliphatic nylons. In some embodiments, the first polyamide may include a polyamide having aliphatic and / or aromatic components. The terms "PA6 polymer" and "PA6 polyamide polymer" used herein also include copolymers with PA6 as the main component. The terms "PA66 polymer" and "PA66 polyamide polymer" used herein also include copolymers with PA66 as the main component. In some cases, physical blends of these polymers are envisioned, such as melt blends. In one embodiment, the polyamide polymer comprises PA66; PA6; PA610; PA611; PA612; PA10; PA11; PA12 or a combination thereof. Exemplary copolymers of these polyamides include PA66 / 6; PA66 / 610; PA66 / 611; PA66 / 612; PA66 / 10; PA66 / 11; PA66 / 12; PA6 / 6,6; PA6 / 610; PA6 / 611; PA6 / 612; PA6 / 10; PA6 / 11; and PA6 / 12.

[0022] As used herein, the terms "PA66," "nylon 66," and "polyamide 66" refer to homopolymers prepared from hexamethylenediamine and adipic acid monomer subunits. A PA66 polyamide can be a polyamide containing a significant portion of PA66 units in the polymer backbone, for example, at least 5 weight percent, at least 10 weight percent, at least 20 weight percent, at least 30 weight percent, at least 40 weight percent, at least 50 weight percent, at least 60 weight percent, at least 70 weight percent, at least 80 weight percent, or at least 90 weight percent. As used herein, the terms "PA6," "nylon 6," and "polyamide 6" refer to homopolymers prepared from caprolactam monomer subunits. As used herein, the terms "PA66 / 6," "nylon 66 / 6," and "polyamide 66 / 6" refer to copolymers prepared from hexamethylenediamine and adipic acid monomer subunits and also containing caprolactam monomer subunits.

[0023] The first polyamide can be a copolymer or a homopolymer. For example, the first polyamide can be a copolymer of PA6 and PA66, a PA6 homopolymer, or a PA66 homopolymer.

[0024] Similarly, the second polyamide, also referred to as concentrate polyamide, can include various natural and artificial polyamides, as disclosed above for the first polyamide.Furthermore, similar to the first polyamide, the second polyamide can be a copolymer or a homopolymer.

[0025] In one embodiment, the first polyamide or base polyamide is a homopolymer and the second polyamide or concentrate polyamide is a polyamide copolymer. For example, the first polyamide is a PA66 homopolymer and the second polyamide is a PA66 / 6 copolymer or a PA66 / 610 copolymer.

[0026] In some embodiments, the first polyamide, such as PA66 homopolymer, is present in the polyamide composition in an amount ranging from 50% to 99% by weight, such as 50% to 95% by weight, 50% to 90% by weight, 60% to 99% by weight, 60% to 95% by weight, 75% to 99% by weight, 75% to 95% by weight, 80% to 99% by weight, 80% to 95% by weight, or 85% to 95% by weight. In terms of upper limits, the first polyamide can be present in an amount less than 99% by weight, such as less than 95% by weight or less than 90% by weight. In terms of lower limits, the first polyamide can be present in an amount greater than 50% by weight, such as greater than 60% by weight, greater than 70% by weight, greater than 80% by weight, greater than 90% by weight, greater than 95% by weight, or greater than 99% by weight.

[0027] The polyamide in the polyamide composition may comprise a combination of polyamides. By combining various polyamides, the final composition can combine the desirable properties of each component polyamide, such as mechanical properties.

[0028] In addition to the first and second polyamides, the polyamide composition may also contain further polyamides which are identical to or different from the first and second polyamides and which may represent any of the polyamides mentioned above with respect to the first polyamide.

[0029] Elastomer concentrates

[0030] The polyamide composition comprises an elastomer concentrate comprising an aliphatic polyamide and an aliphatic polyetheramine, such as a diamine, triamine, or tetraamine. As used herein, the term "polyetheramine" refers to a diamine, a triamine, a tetraamine, or a combination thereof, unless otherwise specified. In some cases, the elastomer concentrate comprises 20-80% by weight of an elastomeric aliphatic polyetherdiamine having a molecular weight of 400-4000 g / mol; and 80-20% by weight of a concentrate polyamide (the second polyamide). As described above, it has been unexpectedly discovered that the addition of the elastomer concentrate provides the aforementioned synergistic combination of performance characteristics.

[0031] The weight percentages of the elastomer concentrate may comprise 20-80 weight percent of the elastomeric aliphatic polyether diamine, triamine, or tetraamine and 80-20 weight percent of the concentrate polyamide. For example, the elastomer concentrate may comprise 40 weight percent of the elastomeric aliphatic polyether and 60 weight percent of the concentrate polyamide; for example, 45 weight percent of the elastomeric aliphatic polyether and 55 weight percent of the concentrate polyamide; 50 weight percent of the elastomeric aliphatic polyether and 50 weight percent of the concentrate polyamide; 55 weight percent of the elastomeric aliphatic polyether and 45 weight percent of the concentrate polyamide; or 60 weight percent of the elastomeric aliphatic polyether and 40 weight percent of the concentrate polyamide.

[0032] In one embodiment, the elastomeric aliphatic polyether diamine preferably contains at least 70% primary amines, e.g., at least 75% primary amines, at least 80% primary amines, at least 85% primary amines, or at least 90% primary amines, based on the total number of amines in the elastomeric aliphatic polyether diamine.

[0033] With respect to the elastomeric aliphatic polyether, the elastomer concentrate may comprise, as an upper limit, less than 80% by weight of the elastomeric aliphatic polyether, e.g., less than 60% by weight, less than 55% by weight, less than 50% by weight, less than 45% by weight, or less than 40% by weight. As a lower limit, the elastomer concentrate may comprise greater than 20% by weight of the elastomeric aliphatic polyether, e.g., greater than 40% by weight, greater than 45% by weight, greater than 50% by weight, greater than 55% by weight, or greater than 60% by weight.

[0034] With respect to the concentrate polyamide, the elastomer concentrate may comprise, as an upper limit, less than 80% by weight of the concentrate polyamide, for example, less than 60% by weight, less than 55% by weight, less than 50% by weight, less than 45% by weight, or less than 40% by weight. As a lower limit, the elastomer concentrate may comprise greater than 20% by weight of the concentrate polyamide, for example, greater than 40% by weight, greater than 45% by weight, greater than 50% by weight, greater than 55% by weight, or greater than 60% by weight.

[0035] In one embodiment, the elastomer concentrate contains a small amount of a monoamine component, such as an aliphatic polyether monoamine, and preferably may be substantially free of a monoamine component.

[0036] In one embodiment, the elastomeric aliphatic polyetherdiamine comprises a compound of formula (I):

[0037]

[0038] Each n can be 1 to 5, such as 1 to 4, 1 to 3, 2 to 5, 2 to 4, or 3 to 5. For example, each n can be 1, 2, 3, 4, or 5. When n is 1, an ethylene oxide moiety may be present; when n is 3, a tetramethyl ether moiety may be present.

[0039] In some cases, each x is from 1 to 50. As the value of x increases, the molecular weight of the elastomeric aliphatic polyether becomes higher. Typically, the elastomeric aliphatic polyether has a molecular weight of 400-4000 g / mol, for example, 500-2500 g / mol; 500-2000 g / mol; 500-1500 g / mol; 1000-1500 g / mol; 1500-2000 g / mol; 1000-2000 g / mol; or 1500-2500 g / mol.

[0040] In some cases, y is 0 to 2. When y is 0, the elastomeric aliphatic polyether is a diamine. When x is 1 or 2, the elastomeric aliphatic polyether is a triamine or tetraamine, respectively.

[0041] In one embodiment, n is 1, x is 0, and the elastomeric aliphatic polyether has a molecular weight of 500-1500 g / mol. In this embodiment, the elastomeric aliphatic polyether is polytetramethyl ether diamine.

[0042] In another embodiment, n is 3, x is 0, and the elastomeric aliphatic polyether has a molecular weight of 1500-2500 g / mol. In this embodiment, the elastomeric aliphatic polyether is polyethylene oxide diamine.

[0043] According to one embodiment, the compound of formula (I) can be selected from difunctional, trifunctional or tetrafunctional polyetheramines, wherein the alkylene structural unit contains carbon atoms. Such polyetheramines can be used as Jeffamine TM and Elastamine TM Commercially available, both from Huntsman. In particular, Elastamine HE1700 and Elastamine HT1100 may be used.

[0044] In some cases, the concentrate may include the polyamides mentioned above with respect to the base polyamide, particularly PA6, PA66, P610, PA12, and / or combinations thereof. In some embodiments, the base polyamide and the concentrate polyamide are different from each other. This may allow the base polyamide to be PA66, while the concentrate polyamide is a combination of PA6 / PA66 or PA66 / PA612. In other embodiments, the base polyamide and the concentrate polyamide are compatible polyamides.

[0045] In some embodiments, the concentrate polyamide or the second polyamide unit as mentioned above can be a polyamide or a copolyamide comprising a combination of the following two monomers: PA66; PA6; PA6,10; PA6,11; PA6,12; PA10; PA11; and PA12. Exemplary copolyamides include PA66 / 6; PA66 / 6,10; PA66 / 6,11; PA66 / 6,12; PA66 / 10; PA66 / 11; PA66 / 12; PA6 / 6,6; PA6 / 6,10; PA6 / 6,11; PA6 / 6,12; PA6 / 10; PA6 / 11; and PA6 / 12.

[0046] During the polymerization process, the second polyamide can be combined with the elastomeric aliphatic polyether to form a terpolymer. For example, when the second polyamide represents a PA66 / 610 copolymer, the elastomer concentrate can be a PA66 / 610 / elastomeric aliphatic polyether terpolymer. Alternatively, when the second polyamide represents a PA66 / 6 copolymer, the elastomer concentrate can be a PA66 / 6 / elastomeric aliphatic polyether terpolymer.

[0047] The elastomer concentrate may also be characterized as having repeating units of an elastomeric aliphatic polyether and a concentrate polyamide, including components of the concentrate polyamide, such as adipic acid and hexamethylenediamine when the concentrate polyamide comprises PA66. Even from this perspective, the elastomer concentrate comprises a copolymer / terpolymer comprising repeating units of the elastomer and repeating units of a polyamide comprising repeating units of PA66; PA6; PA610; PA611, PA612; PA10; PA11; or PA12; or combinations thereof.

[0048] For example, in one embodiment, the elastomer concentrate can be represented by formula (II), wherein the X component represents the elastomeric aliphatic polyether and the Y component represents the concentrate polyamide. In this embodiment, the elastomeric aliphatic polyether is represented by polytetramethyl ether diamine.

[0049]

[0050] In formula (II), a is 2 to 16, b is 4 to 12, and c is 2 to 16. X constitutes 30 to 70% by weight of the polymer, and Y constitutes 30 to 70% by weight of the polymer.

[0051] In case the concentrate polyamide represents a copolymer, the composition of formula (II) can be further reacted with another polyamide.Formulas (III) and (IV) represent embodiments in which the polyamide concentrate is a copolymer.

[0052]

[0053] In formula (III), a is 2-16, b is 4-12, c is 2-16, d is 4-12, and e is 2-16. X constitutes 30-65% by weight of the polymer, Y constitutes 30-65% by weight of the polymer, and Z constitutes 5-20% by weight of the polymer.

[0054] In formula (IV), a is 2-16, b is 4-12, c is 2-16, and d is 4-11. X constitutes 30-60 wt % of the polymer, Y constitutes 10-60 wt % of the polymer, and Z constitutes 10-60 wt % of the polymer.

[0055] Additional examples of these structures can be shown when the elastomeric aliphatic polyether is represented as polyethylene oxide diamine.Similar to the above chemical structure, in formula (V), the X component represents the elastomeric aliphatic polyether and the Y component represents the condensate polyamide.

[0056]

[0057] In formula (V), each n is 1-50; X constitutes 30-70 weight percent of the polymer; and Y constitutes 30-70 weight percent of the polymer.

[0058] In case the concentrate polyamide represents a copolymer, the composition of formula (V) can be further reacted with another polyamide.Formula (VI) represents an embodiment wherein the polyamide concentrate is a copolymer.

[0059]

[0060] In formula (VI), each n is 1 to 50 and m is 4 to 11. X constitutes 30 to 65 weight percent of the polymer, Y constitutes 30 to 65 weight percent of the polymer, and Z constitutes 5 to 20 weight percent of the polymer.

[0061] The above structures shown in Formulas II-VI are illustrative examples of elastomer concentrates when the elastomeric aliphatic polyether is represented by polytetramethyl ether diamine or polyethylene oxide diamine. When other elastomeric aliphatic polyethers are used, a variety of other polymers will be apparent to those skilled in the art, all falling within the scope of the present disclosure. Similarly, when other polyamide concentrates are used, a variety of other elastomer concentrate polymers will be apparent to those skilled in the art, in addition to those shown in Formulas II-VI.

[0062] For example, elastomer concentrates formed as block copolymers, more particularly polyamide-block-ethers having ester linkages, are also contemplated. Formulas VII-VIII represent illustrative examples of these embodiments.

[0063]

[0064] In Formula VII, a is 4-12; X constitutes 30-70% by weight of the polymer; and Y constitutes 30-70% by weight of the polymer. In Formula VIII, a is 4-12; b is 2-16; X constitutes 30-70% by weight of the polymer; and Y constitutes 30-70% by weight of the polymer.

[0065] The total weight percentage of the base polyamide and / or elastomer concentrate in the polyamide composition, based on the total amount of the base polyamide and the elastomer concentrate, can vary widely. For example, the polyamide composition can comprise 1-25 weight percent elastomer concentrate and 75-99 weight percent base polyamide; 1-15 weight percent elastomer concentrate and 85-99 weight percent base polyamide; 1-10 weight percent elastomer concentrate and 90-99 weight percent base polyamide; 5-15 weight percent elastomer concentrate and 85-95 weight percent base polyamide; 5-20 weight percent elastomer concentrate and 80-95 weight percent base polyamide; or 5-10 weight percent elastomer concentrate and 90-95 weight percent base polyamide.

[0066] Regarding the base polyamide, the polyamide composition may contain, as an upper limit, less than 99% by weight of the base polyamide, for example, less than 95% by weight, less than 90% by weight, less than 85% by weight, less than 80% by weight, or less than 75% by weight. As a lower limit, the polyamide composition may contain greater than 75% by weight of the base polyamide, for example, greater than 80% by weight, greater than 85% by weight, greater than 90% by weight, greater than 95% by weight, or greater than 99% by weight.

[0067] Regarding the elastomer concentrate, the polyamide composition may contain, as an upper limit, less than 25% by weight of the elastomer concentrate, for example, less than 20% by weight, less than 15% by weight, less than 10% by weight, less than 5% by weight, or less than 1% by weight. As a lower limit, the polyamide composition may contain more than 1% by weight of the elastomer concentrate, for example, more than 5% by weight, more than 10% by weight, more than 15% by weight, more than 20% by weight, or more than 25% by weight.

[0068] Another embodiment relates to the elastomer concentrate itself. This embodiment is an elastomer concentrate comprising 20-80% by weight of an elastomeric aliphatic polyether having a molecular weight of 400-4000 g / mol and 80-20% by weight of a concentrate polyamide. The elastomeric aliphatic polyether and the concentrate polyamide in this embodiment are the same components as described above.

[0069] After the elastomer concentrate is prepared, it can be blended with the base polyamide using known manufacturing techniques. This can occur simultaneously with, shortly thereafter, or at a later point in time as the elastomer concentrate is prepared. For example, it may be desirable to prepare the elastomer concentrate at one location at a certain point in time, transport it to a second location, and have the elastomer concentrate blended with the base polyamide by a second party (e.g., a customer).

[0070] Alternatively, polyamide elastomers can be used by themselves in various applications for soft-touch, flexible, tough materials. For example, polyamide elastomers can be a substitute for polyurethane elastomers, copolyester elastomers, or polyamide-block-ether elastomers.

[0071] Method for producing elastomer concentrate

[0072] Many problems are encountered when incorporating polyether diamines, triamines, and / or tetraamines into elastomer concentrate preparations. Notably, several useful polyetheramines are water-insoluble, which creates problems when used in aqueous polymerization processes for producing polyamides, whether these processes are batch or continuous. The added polyetheramines can be viscous liquids.

[0073] Polyamide polymerization can be a continuous process or a batch process using an aqueous salt solution of a diacid and a diamine. The salt solution mixes water with the diacid and diamine in a molar ratio of 5:1 to 1:5, such as 3:1 to 1:3, such as 2:1 to 1:2, or more preferably 1:1. In one embodiment, the salt solution may contain 10 to 90 weight percent of a diacid having 6 or fewer carbon atoms and 90 to 10 weight percent of a diamine having 6 or fewer carbon atoms, each weight percent based on the total weight of the salt solution. More preferably, the salt solution may contain 20 to 80 weight percent of a diacid having 6 or fewer carbon atoms and 80 to 20 weight percent of a diamine having 6 or fewer carbon atoms, each weight percent based on the total weight of the salt solution. In some embodiments, the salt solution may further contain 0 to 40 weight percent of a diacid having more than 6 carbon atoms, such as 6 to 14 carbon atoms or 6 to 12 carbon atoms.

[0074] Commercial production methods for polyamide 66 use aqueous salt solutions of hexamethylenediamine and adipic acid. Other diacids (sebacic acid, decanedioic acid, and / or dodecanedioic acid) or diamines may be added to this aqueous salt solution. This aqueous salt solution typically has a solids content of less than or equal to 60%, for example, 20 to 60% or 30 to 60%. These low solids levels hinder the incorporation of polyetheramines into elastomer concentrates. To overcome this limitation, the present invention has developed a method for successfully processing elastomer concentrates in a cost-effective manner.

[0075] For larger-scale polyamide polymerizations based on diamines and diacids, the present invention uses separate evaporation and polymerization vessels to efficiently deliver reactive monomers. An aqueous salt solution can be metered from a strike vessel at an initial solids content of 30-60 wt% and pumped to an evaporator vessel, concentrated by heating to above 100°C, and then introduced into a polymerization reactor, such as an autoclave, plug flow reactor, or stirred tank reactor, for polycondensation. Multiple salts can be combined in the evaporator vessel. In some embodiments, the salts in the evaporator vessel can be mixed with other diacids, diamines, and lactams, such as caprolactam.

[0076] In some embodiments, the reactor can be operated as two vessels, and the salt solution can be concentrated in the reactor before the reaction to increase the solids content. Thus, in one embodiment, a method for producing a polyamide elastomer is provided, comprising feeding a salt solution into a reactor having a phosphorus-containing catalyst having a phosphorus content of 5 to 1000 parts per million based on the total weight of the catalyst; reducing the water content in the reactor; feeding a polyetheramine into the reactor after the water content has been reduced; and polymerizing the salt solution and the polyetheramine at a temperature of 240° C. to 260° C. under reduced pressure, for example, less than or equal to 2 atm, to form a polyamide elastomer. As used herein, reduced pressure refers to reducing the pressure of the reactor.

[0077] The evaporator vessel concentrates the salt solution to a higher solids content suitable for incorporating the polyetheramine into the elastomer concentrate. The solids content can be greater than or equal to 80%, for example, greater than or equal to 85%, or greater than or equal to 90%. In one embodiment, the salt solution has a solids content of 80% to 95%, for example, 80% to 90%. Increasing the solids content to at least 80% enables the incorporation of the polyetheramine. However, when the solids content becomes disproportionate, such as exceeding 95%, the process becomes inefficient and other challenges arise.

[0078] In one embodiment, the pressure and / or temperature conditions of the evaporator are carefully adjusted to remove water, for example as steam, and produce a concentrated salt solution. Preferably, the evaporator is operated under conditions that prevent or inhibit polymerization of the concentrated monomer solution. To achieve a concentrated salt solution, the process can operate the evaporator at a temperature of 100° C. to 215° C., for example, 100° C. to 200° C., 100° C. to 175° C., 105° C. to 175° C., or 105° C. to 150° C. In one embodiment, the evaporator can be operated at a pressure of 0.5 atm to 50 atm, for example, 1 atm to 40 atm, 1 atm to 35 atm, 1 to 30 atm, 1 atm to 20 atm, or 1 atm to 10 atm, 1 atm to 5 atm, or 1 atm to 3.5 atm. In a continuous process, the residence time of the salt solution in the evaporator can be 5 to 300 minutes, for example, 20 to 250 minutes, 20 to 200 minutes. According to some embodiments, the polyetheramine or at least a portion thereof can be added to the evaporator vessel.Since polymerization conditions are absent, the polyetheramine can be mixed into the concentrated salt solution.

[0079] The concentrated monomer salt solution is removed from the evaporator and can be pumped and / or metered to the reactor via a pipeline. The pipeline may have a heat jacket. According to some embodiments, the polyetheramine or at least a portion thereof can be added to the pipeline and combined with the monomer salt solution. To prevent clogging and corrosion problems, the conditions in the pipeline are maintained to inhibit polymerization conditions. In one embodiment, the concentrated monomer salt solution can leave the evaporator at a temperature of 100°C to 200°C, for example, 110°C to 190°C, 120°C to 180°C, 130°C to 170°C, 140°C to 160°C, or 145°C to 155°C. In terms of upper limits, the concentrated monomer salt solution leaves the evaporator at a temperature of less than 200°C, for example, less than 180°C, less than 160°C, less than 140°C, less than 120°C, or less than 110°C. In terms of lower limits, the concentrated monomer salt solution exits the evaporator at a temperature greater than 100°C, eg, greater than 120°C, greater than 140°C, greater than 160°C, greater than 170°C, greater than 180°C, or greater than 190°C.

[0080] The concentrated salt solution is introduced into the reactor vessel. According to some embodiments, the polyetheramine is preferably added to the reactor after the solids content is concentrated, unless the polyetheramine is added to the evaporator or pipeline before the reactor vessel. In one embodiment, at least 50% of the polyetheramine is added to the reactor, such as at least 60%, at least 70%, or at least 75%. In some embodiments, the entire amount of the polyetheramine is added to the reactor. The remainder, if any, can be added proportionally to the evaporator and / or pipeline.

[0081] In order to control and / or manipulate the molecular weight, some embodiments may also add the diamine component or the diacid component in a stoichiometric excess. The diamine component or the diacid component may be added separately from the salt solution in an amount of 5 to 500 mmol / kg, e.g., 10 to 200 mmol / kg or 15 to 150 mmol / kg, based on the combined weight of the salt solution and the polyetheramine.

[0082] Temperature and pressure may vary depending on the reactor type, salt solution, and polyetheramine monomer. Generally, the temperature and pressure should be sufficient to remove water from the condensation reaction and / or avoid solidification. In one embodiment, the reactor is operated at a peak temperature within an operable range of 180°C to 320°C, such as 200°C to 300°C, 210°C to 290°C, 220°C to 280°C, 230°C to 270°C, 240°C to 270°C, 245°C to 265°C, or 250°C to 260°C. In one embodiment, the reactor can be operated at a pressure of 0.05 atm to 25 atm, such as 0.1 atm to 20 atm, 0.1 atm to 18 atm, 0.1 atm to 15 atm, 0.1 atm to 10 atm, 0.1 atm to 5 atm, 0.1 to 4 atm, 0.15 atm to 2 atm, or 0.15 to 1 atm. The residence time can be adjusted as a parameter during the polymerization to avoid polymer degradation. The residence time in the reactor can be 20 to 240 minutes, such as 20 to 180 minutes, 30 to 150 minutes, 30 to 120 minutes, or 45 to 90 minutes.

[0083] In one embodiment, once the target temperature is reached in the reactor, preferably 240° C. to 260° C., the pressure in the reactor is reduced to less than or equal to 2 atm, e.g., less than 1.5 atm, less than 1.25 atm, less than 1 atm, less than 0.9 atm, less than 0.75, less than 0.6 atm, less than 0.5 atm, or less than 0.4 atm. In terms of ranges, the reduced pressure may be from 0.1 atm to 2 atm, e.g., from 0.2 atm to 1.5 atm, from 0.2 atm to 1.25 atm, from 0.2 atm to 1 atm, from 0.2 atm to 0.9 atm, from 0.3 atm to 0.9 atm, from 0.3 atm to 0.75 atm, from 0.3 atm to 0.6 atm. The polymerization reaction is carried out at the reduced pressure for a period of 20 to 240 minutes, e.g., from 20 to 180 minutes, from 30 to 150 minutes, from 30 to 120 minutes, or from 45 to 90 minutes. In one embodiment, the target temperature is maintained during the reaction.

[0084] In most embodiments, it is useful that the reactor vessel contains a polymerization catalyst. In one embodiment, the reactor vessel contains a phosphorus compound, such as phosphoric acid, phosphorous acid, hypophosphorous acid, phenylphosphonic acid, phenylphosphinic acid and / or have a monovalent to trivalent cation, such as their salts of Na, K, Mg, Ca, Zn or Al, and / or their esters, such as monosodium phosphate, triphenyl phosphate, triphenyl phosphite or tris(nonylphenyl) phosphite. Particularly preferred catalysts are hypophosphorous acid and salts thereof, such as sodium hypophosphite or manganese hypophosphite. In order to realize polymerization, catalyst can be used in an amount of 0.005 to 2.5 % by weight based on the gross weight of concentrated salt solution and polyetheramine. In a more preferred embodiment, catalyst can be used in an amount of 0.01 to 2.0 % by weight based on the gross weight of concentrated salt solution and polyetheramine. In one embodiment, the phosphorus-containing catalyst has a phosphorus content of 5 to 1000 ppm, eg, 5 to 500 ppm, 5 to 250 ppm, 10 to 250 ppm, 10 to 200 ppm, 10 to 150 ppm, or 10 to 100 ppm.

[0085] The stirred tank reactor can be equipped with a suitable agitator, such as a disk, screw or stirrer. The rotation of the agitator can be controlled to maintain sufficient circulation in the reactor.

[0086] In some embodiments, an inert gas can be injected into the reactor during the reaction. The inert gas can be, but is not limited to, helium, nitrogen, carbon dioxide, argon and / or neon. In order to limit the excess water in the reactor, the inert gas is usually dry. In one embodiment, the inert gas injected into the reactor is preferably nitrogen. The inert gas can be preheated and injected at a pressure slightly higher than that of the reactor.

[0087] Under these reactor conditions, polymerization of the monomers and polyetheramine occurs to produce the copolymers described herein, such as those of Formulae III-VI, at favorable monomer conversions. In one embodiment, the monomer conversion in the salt solution is greater than 80%, e.g., greater than 85%, greater than 90%, or greater than 95%. In one embodiment, the conversion of the polyetheramine is greater than 80%, e.g., greater than 85%, greater than 90%, or greater than 95%.

[0088] The polyamide obtained in molten form by the process of the invention can be shaped directly or can be extruded and pelletized for an optional postcondensation step and / or for subsequent conformation after melting.

[0089] Thus, in one embodiment, a method for producing a polyamide elastomer is provided, comprising feeding a salt solution having a solids content of greater than or equal to 80% into a reactor containing a phosphorus-containing catalyst having a phosphorus content of 5 to 1000 parts per million based on the total weight of the catalyst, feeding a polyetheramine comprising a polyetherdiamine, a triamine, a tetraamine, or a combination thereof into the reactor, and upon reaching a target temperature, for example, in the range of 240°C to 260°C, reducing the pressure in the reactor to polymerize the salt solution and the polyetheramine to form the polyamide elastomer. The target temperature can be a trigger for reducing the pressure, and the reactor can be operated outside the target temperature. In one embodiment, the reactor can be heated until a target temperature in the range of 240°C to 260°C is achieved, for example, in the range of 240°C to 258°C, in the range of 242°C to 258°C, in the range of 240°C to 255°C, or in the range of 245°C to 255°C. The reactor can be maintained at the target temperature, heating and cooling as needed. As described herein, the salt solution can be an aqueous solution of a concentrate polyamide (the second polyamide).

[0090] In one embodiment, the method may polymerize the salt solution and the polyetheramine at a temperature of 240° C. to 260° C. under reduced pressure to form the polyamide elastomer.

[0091] The methods disclosed herein provide polyamide elastomers having a number average molecular weight (Mn) greater than or equal to 5,000 g / mol, e.g., greater than or equal to 7,500 g / mol, greater than or equal to 9,000 g / mol, greater than or equal to 10,000 g / mol, greater than or equal to 11,000 g / mol, greater than or equal to 12,000 g / mol, greater than or equal to 13,000 g / mol, greater than or equal to 14,000 g / mol, greater than or equal to 15,000 g / mol, or greater than or equal to 16,000 g / mol. In terms of upper limits, the polyamide elastomer may have a number average molecular weight less than or equal to 30,000 g / mol, e.g., less than or equal to 25,000 g / mol, less than or equal to 20,000 g / mol, less than or equal to 19,000 g / mol, less than or equal to 18,000 g / mol, or less than or equal to 17,000 g / mol. Thus, in terms of ranges, the polyamide elastomer has a number average molecular weight of 5,000 g / mol to 30,000 g / mol, including subranges therein, for example, 7,500 g / mol to 25,000 g / mol, 9,000 g / mol to 20,000 g / mol, 10,000 g / mol to 19,000 g / mol, or 10,000 g / mol to 17,000 g / mol.

[0092] The methods disclosed herein provide polyamide elastomers having a weight average molecular weight (Mw) greater than or equal to 12,000 g / mol, e.g., greater than or equal to 15,000 g / mol, greater than or equal to 18,000 g / mol, greater than or equal to 20,000 g / mol, greater than or equal to 25,000 g / mol, greater than or equal to 30,000 g / mol, greater than or equal to 35,000 g / mol, greater than or equal to 40,000 g / mol, greater than or equal to 45,000 g / mol, or greater than or equal to 50,000 g / mol. In terms of upper limits, the polyamide elastomer can have a weight average molecular weight less than or equal to 65,000 g / mol, e.g., less than or equal to 60,000 g / mol, less than or equal to 55,000 g / mol, less than or equal to 50,000 g / mol, less than or equal to 45,000 g / mol, or less than or equal to 40,000 g / mol. Thus, in terms of ranges, the polyamide elastomer has a weight average molecular weight of 12,000 g / mol to 65,000 g / mol, including subranges therein, for example, 15,000 g / mol to 60,000 g / mol, 20,000 g / mol to 60,000 g / mol, 20,000 g / mol to 55,000 g / mol, or 25,000 g / mol to 55,000 g / mol.

[0093] The polyamide elastomer has a polydispersity index (PDI), i.e., weight average molecular weight / number average molecular weight (Mw / Mn), of 1.0 to 3.5, e.g., 1.2 to 3.5, 1.3 to 3.2, 1.5 to 3.1, 1.6 to 3.1, 1.7 to 3.1, 1.8 to 3.1, 1.9 to 3.1, 1.9 to 3.0, 1.9 to 2.8, 2.0 to 2.8, or 2.0 to 2.7. When the polydispersity index is controlled within these ranges, the present inventors have found that the polyamide elastomer has desirable properties.

[0094] In one embodiment, the relative viscosity (RV) of the polyamide elastomer is from 35 to 50, e.g., from 35 to 45 or from 40 to 45. The RV of a polyamide elastomer is typically the ratio of solution or solvent viscosities measured in a capillary viscometer at 25°C (ASTM D 789)(2015). In this case, the solvent is formic acid containing 10 wt% water and 90 wt% formic acid. The solution is 8.4 wt% polymer dissolved in the solvent.

[0095] The polyamide elastomer has a melting temperature (Tm) or melting point suitable for high temperature applications. In one embodiment, the polyamide elastomer has a melting temperature greater than or equal to 185°C, such as greater than or equal to 190°C, greater than or equal to 200°C, greater than or equal to 205°C, greater than or equal to 210°C, greater than or equal to 215°C, greater than or equal to 220°C, greater than or equal to 225°C, or greater than or equal to 230°C. Suitable ranges for the melting temperature can be 185°C to 280°C, such as 185°C to 260°C, 200°C to 260°C, or 200°C to 250°C.

[0096] The polyamide elastomer preferably has a crystallization temperature (Tc) that establishes a suitable operating temperature window. In one embodiment, the polyamide elastomer has a crystallization temperature of less than or equal to 185°C, such as less than or equal to 180°C, less than or equal to 175°C, less than or equal to 170°C, less than or equal to 165°C, less than or equal to 160°C, less than or equal to 155°C, less than or equal to 150°C, or less than or equal to 145°C. A crystallization temperature that differs from the melting temperature by at least 30°C is more preferred, such as at least 35°C, at least 40°C, at least 45°C, at least 50°C, or at least 55°C. Suitable ranges for the crystallization temperature may be 100°C to 185°C, such as 110°C to 180°C, 115°C to 175°C, or 120°C to 165°C.

[0097] Melting temperature and crystallization temperature are measured by DSC according to standard ISO 11357-3.

[0098] Heat stabilizer kit

[0099] When used in environments subjected to relatively high temperatures for extended periods, polyamide compositions may experience a reduction in mechanical properties due to thermal degradation. To prevent such adverse effects, the polyamide composition may include a thermal stabilizer package that improves the utility and functionality of the polyamide composition by mitigating, delaying, or preventing the effects of thermal damage and / or thermo-oxidative damage. In some embodiments, the thermal stabilizer package may be incorporated into the elastomer concentrate.

[0100] In some embodiments, the thermal stabilizer kit comprises a combination of thermal stabilizers, such as a first thermal stabilizer and a second thermal stabilizer.

[0101] Thermal stabilizer sets can vary widely and include any polymer (polyamide) thermal stabilizer known and commercially available. Suitable thermal stabilizers for polyamide compositions are disclosed in U.S. Patent Application No. 2020 / 0247994, which is incorporated herein by reference in its entirety. Typically, the thermal stabilizer can be a compound comprising a lanthanide, such as cerium or lanthanum. In some embodiments, the lanthanide can be lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium or lutetium, or a combination thereof. In some cases, the lanthanide-based thermal stabilizer can have an oxidation number of +III or +IV.

[0102] In some cases, the thermal stabilizer is generally of the structure (L)X n , wherein X is a ligand and n is a non-zero integer, and L is a lanthanide. That is, in some embodiments, the lanthanide-based thermal stabilizer is a lanthanide-based ligand. The inventors have found that specific lanthanide ligands are particularly good at stabilizing polyamides, especially when used in the amounts, limits, and / or ratios mentioned above. In some embodiments, the ligand can be selected from acetates, hydrates, oxygen-containing hydrates (oxyhydrates), phosphates, bromides, chlorides, oxides, nitrides, borides, carbides, carbonates, ammonium nitrates, fluorides, nitrates, polyols, amines, phenols, hydroxides, oxalates, oxyhalides, chromates (chromoates), sulfates or aluminates, perchlorates, sulfur, monochalcogenides of selenium and tellurium, carbonates, hydroxides, oxides, trifluoromethanesulfonates, acetylacetonates, alkoxides, 2-ethylhexanoates, or combinations thereof. Hydrates of these are also contemplated.

[0103] In some cases, the ligand can be an oxide and / or an oxyhydrate. In some embodiments, the thermal stabilizer comprises a specific oxide / oxyhydrate compound, preferably a lanthanide (cerium) oxide and / or a lanthanide (cerium) oxyhydrate.

[0104] In some embodiments, the polyamide composition comprises a lanthanide-based compound, such as cerium / lanthanum oxide and / or cerium / lanthanum oxyhydrate, in an amount of 0.01 wt% to 10.0 wt%, e.g., 0.01 wt% to 8.0 wt%, 0.01 wt% to 7.0 wt%, 0.02 wt% to 5.0 wt%, 0.03 to 4.5 wt%, 0.05 wt% to 4.5 wt%, 0.07 wt% to 4.0 wt%, 0.07 wt% to 3.0 wt%, 0.1 wt% to 3.0 wt%, 0.1 wt% to 2.0 wt%, 0.2 wt% to 1.5 wt%, 0.1 wt% to 1.0 wt%, or 0.3 wt% to 1.2 wt%. In terms of lower limits, the polyamide composition may include greater than 0.01 wt % of heat stabilizer, for example, greater than 0.02 wt %, greater than 0.03 wt %, greater than 0.05 wt %, greater than 0.07 wt %, greater than 0.1 wt %, greater than 0.2 wt %, or greater than 0.3 wt %. In terms of upper limits, the polyamide composition may include less than 10.0 wt % of heat stabilizer, for example, less than 8.0 wt %, less than 7.0 wt %, less than 5.0 wt %, less than 4.5 wt %, less than 4.0 wt %, less than 3.0 wt %, less than 2.0 wt %, less than 1.5 wt %, less than 1.2 wt %, less than 1.0 wt %, or less than 0.7 wt %.

[0105] In some embodiments, the polyamide composition comprises less than 1.0 wt % ceria, e.g., less than 0.7 wt %, less than 0.5 wt %, less than 0.3 wt %, less than 0.1 wt %, less than 0.05 wt %, or less than 0.01 wt %. In terms of ranges, the polyamide composition may comprise from 1 wppm to 1 wt % ceria, e.g., from 1 wppm to 0.5 wt %, from 1 wppm to 0.1 wt %, from 5 wppm to 0.05 wt %, or from 5 wppm to 0.01 wt %.

[0106] In some cases, the polyamide composition is almost or completely free of cerium hydrate, such as less than 10.0 wt % cerium hydrate, such as less than 8.0 wt %, less than 7.0 wt %, less than 5.0 wt %, less than 4.5 wt %, less than 4.0 wt %, less than 3.0 wt %, less than 2.0 wt %, less than 1.5 wt %, less than 1.2 wt %, less than 1.0 wt %, less than 0.7 wt %, less than 0.5 wt %, less than 0.3 wt %, or less than 0.1 wt %. In some cases, the polyamide composition is substantially free of cerium hydrate, such as completely free of cerium hydrate.

[0107] In some embodiments, the thermal stabilizer may be selected from phenols, amines, polyols, and combinations thereof.

[0108] For example, the heat stabilizer package may include an amine stabilizer, such as a secondary aromatic amine. Examples include an adduct of phenylenediamine and acetone (Naugard A), an adduct of phenylenediamine and linolene, Naugard 445, N,N′-dinaphthyl-p-phenylenediamine, N-phenyl-N′-cyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine, or a mixture of two or more thereof.

[0109] Other examples include heat stabilizers based on hindered phenols. Examples include N,N′-hexamethylene-bis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionamide, bis-(3,3-bis-(4′-hydroxy-3′-tert-butylphenyl)-butyric acid)-diol ester, 2,1′-thioethyl bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, 4-4′-butylene-bis-(3-methyl-6-tert-butylphenol), triethylene glycol-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionate, or mixtures of these stabilizers.

[0110] Further examples include phosphites and / or phosphonites. Specific examples of phosphites and phosphonites include triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, tri(octadecyl) phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, diisodecyloxy pentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis(2,4,6-tris-(tert-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetra(2,4 -di-tert-butylphenyl)-4,4′-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo-[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocine, bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite and bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite. Particularly preferred are tris[2-tert-butyl-4-thio(2′-methyl-4′-hydroxy-5′-tert-butyl)-phenyl-5-methyl]phenyl phosphite and tris(2,4-di-tert-butylphenyl)phosphite ( PAR24: a product of Clariant, Basel).

[0111] In some embodiments, the heat stabilizer comprises a copper-based stabilizer. As a non-limiting example, the copper-based compound may comprise a compound of monovalent or divalent copper, such as a salt of monovalent or divalent copper with an inorganic or organic acid or with a monovalent or divalent phenol, a complex of a monovalent or divalent copper oxide or a copper salt with ammonia, amine, amide, lactam, cyanide or phosphine, and combinations thereof. In some preferred embodiments, the copper-based compound may comprise a salt of monovalent or divalent copper with a hydrohalic acid, hydrocyanic acid or an aliphatic carboxylic acid, such as copper chloride (I), copper bromide (I), copper iodide (I), copper cyanide (I), copper oxide (II), copper chloride (II), copper sulfate (II), copper acetate (II) or copper phosphate (II). Preferably, the copper-based compound is copper iodide and / or copper bromide. The copper heat stabilizer can be used together with the halide additives discussed below. Copper stearate is also envisioned as a heat stabilizer (not as a stearate additive).

[0112] In some embodiments, the polyamide composition comprises a copper heat stabilizer in an amount of 0.01 wt % to 5.0 wt %, e.g., 0.01 wt % to 4.0 wt %, 0.02 wt % to 3.0 wt %, 0.03 wt % to 2.0 wt %, 0.03 wt % to 1.0 wt %, 0.04 wt % to 1.0 wt %, 0.05 wt % to 0.5 wt %, 0.05 wt % to 0.2 wt %, or 0.07 wt % to 0.1 wt %. In terms of lower limits, the polyamide composition can comprise greater than 0.01 wt % of the copper heat stabilizer, e.g., greater than 0.02 wt %, greater than 0.03 wt %, greater than 0.035 wt %, greater than 0.04 wt %, greater than 0.05 wt %, greater than 0.07 wt %, or greater than 0.1 wt %. In terms of upper limits, the polyamide composition can include less than 5.0 wt% copper heat stabilizer, e.g., less than 4.0 wt%, less than 3.0 wt%, less than 2.0 wt%, less than 1.0 wt%, less than 0.5 wt%, less than 0.2 wt%, less than 0.1 wt%, less than 0.05 wt%, or less than 0.035 wt%.

[0113] In some embodiments, the polyamide composition comprises a copper heat stabilizer, such as a copper-based compound, in an amount of 1 ppm to 1500 ppm, for example, 10 ppm to 1200 ppm, 50 ppm to 1000 ppm, 50 ppm to 800 ppm, 100 ppm to 750 ppm, 200 ppm to 700 ppm, 300 ppm to 600 ppm, or 350 ppm to 550 ppm. As a lower limit, the polyamide composition comprises a copper heat stabilizer greater than 1 ppm, for example, greater than 10 ppm, greater than 50 ppm, greater than 100 ppm, greater than 200 ppm, greater than 300 ppm, or greater than 350 ppm. As an upper limit, the polyamide composition comprises a copper stabilizer less than 1500 ppm, for example, less than 1200 ppm, less than 1000 ppm, less than 800 ppm, less than 750 ppm, less than 700 ppm, less than 600 ppm, or less than 550 ppm.

[0114] The polyamide may further comprise (in addition to the thermal stabilizer) a halide additive, such as chloride, bromide and / or iodide. In some cases, the purpose of the halide additive is to improve the stabilization of the polyamide composition. Surprisingly, the inventors have found that, when used as described herein, the halide additive works in conjunction with the stabilizer package by mitigating free radical oxidation of the polyamide. Exemplary halide additives include potassium chloride, potassium bromide and potassium iodide. In some cases, these additives are used in the amounts discussed herein.

[0115] Halide additives can vary widely. In some cases, a halide additive can be used in conjunction with a copper heat stabilizer. In some cases, the halide additive is not the same component as the copper heat stabilizer; for example, a copper heat stabilizer copper halide is not considered a halide additive. Halide additives are generally known and commercially available. Exemplary halide additives include iodides and bromides. Preferably, the halide additive comprises chloride, iodide, and / or bromide.

[0116] In some embodiments, the halide additive is present in the polyamide composition in an amount of 0.001 wt %, for example, 0.01 wt % to 0.75 wt %, 0.01 wt % to 0.75 wt %, 0.05 wt % to 0.75 wt %, 0.05 wt % to 0.5 wt %, 0.075 wt % to 0.75 wt % or 0.1 wt % to 0.5 wt %. With regard to the upper limit, the halide additive can be present in an amount less than 1 wt %, for example, less than 0.75 wt % or less than 0.5 wt %. With regard to the lower limit, the halide additive can be present in an amount greater than 0.001 wt %, for example, greater than 0.01 wt %, greater than 0.05 wt %, greater than 0.075 wt % or greater than 0.1 wt %.

[0117] In some embodiments, the halide, for example, iodide, is present in an amount of 30 wppm to 5000 wppm, for example, 30 wppm to 3000 wppm, 50 wppm to 2000 wppm, 50 wppm to 1000 wppm, 75 wppm to 750 wppm, 100 wppm to 500 wppm, 150 wppm to 450 wppm, or 200 wppm to 400 wppm. As for lower limits, the halide can be present in an amount of at least 30 wppm, for example, at least 50 wppm, at least 75 wppm, at least 100 wppm, at least 150 wppm, or at least 200 wppm. In terms of upper limits, the halide can be present in an amount of less than 5000 wppm, e.g., less than 3500 wppm, less than 3000 wppm, less than 2000 wppm, less than 1000 wppm, less than 750 wppm, less than 500 wppm, less than 450 wppm, or less than 400 wppm. The total halide, e.g., iodide content, in some cases includes iodide from all sources, e.g., copper iodide, and additives, e.g., potassium iodide.

[0118] The heat-stable polyamide preferably may contain a stearate additive, such as calcium stearate, but in small amounts, if at all. Generally, stearates are known to have no stabilizing effect; instead, stearate additives are typically used for lubrication and / or to aid in demoulding. Due to the use of synergistic small amounts, the heat-stable polyamide compositions of the present disclosure are able to effectively produce polyamide structures without the need for large amounts of stearate lubricants typically present in conventional polyamides, thereby improving production efficiency. The inventors have also found that small amounts of stearate additives reduce the potential for forming harmful stearate degradation products. In particular, it has been found that stearate additives degrade at higher temperatures to cause further stability problems in the polyamide composition.

[0119] In some cases, the polyamide composition is beneficially almost or completely free of stearate, such as calcium stearate and zinc stearate.Stearate additive may exist in a small amount in a collaborative manner.For example, the polyamide composition can include the stearate additive less than 0.3 % by weight, for example, less than 0.25 % by weight, less than 0.2 % by weight, less than 0.15 % by weight, less than 0.10 % by weight, less than 0.05 % by weight, less than 0.03 % by weight, less than 0.01 % by weight or less than 0.005 % by weight. With regard to scope, the polyamide composition can include the stearate additive of 1wppm to 0.3 % by weight, for example, 1wppm to 0.25 % by weight, 5wppm to 0.1 % by weight, 5wppm to 0.05 % by weight or 10wppm to 0.005 % by weight. With regard to lower limits, the polyamide composition can include the stearate additive greater than 1wppm, for example, greater than 5wppm, greater than 10wppm or greater than 25wppm. In some embodiments, the polyamide composition is substantially free of stearate additives, such as completely free of stearate additives.

[0120] In some cases, the polyamide composition is almost or completely free of antioxidant additives, such as phenolic antioxidants, more particularly hindered phenolic antioxidants. As mentioned above, antioxidants are known polyamide stabilizers that can be used in the polyamide compositions of the present disclosure. In some preferred embodiments, the polyamide composition is free of antioxidants and achieves production efficiency. In other embodiments, depending on the type and amount of the polyether, an antioxidant can be used to provide stability. For example, the polyamide composition may contain less than 5 wt % of an antioxidant additive, such as less than 4.5 wt %, less than 4.0 wt %, less than 3.5 wt %, less than 3.0 wt %, less than 2.5 wt %, less than 2.0 wt %, less than 1.5 wt %, less than 1.0 wt %, less than 0.5 wt % or less than 0.1 wt %. In terms of ranges, the polyamide composition can include 0.0001 wt% to 5 wt% antioxidant, e.g., 0.001 wt% to 4 wt%, 0.01 wt% to 3 wt%, 0.01 wt% to 2 wt%, 0.01 wt% to 1 wt%, 0.01 wt% to 0.5 wt%, or 0.05 wt% to 0.5 wt%. In terms of lower limits, the polyamide composition can include greater than 0.0001 wt% antioxidant additive, e.g., greater than 0.001 wt%, greater than 0.01 wt%, greater than 0.05, or greater than 0.1 wt%.

[0121] lubricant

[0122] The polyamide composition may include one or more lubricants known to those skilled in the art to be compatible with the polyamide composition. Suitable lubricants include long-chain fatty acids (such as stearic acid or behenic acid), their salts (such as calcium stearate or zinc stearate) or their esters or amide derivatives (such as ethylene bis stearamide), montan wax (a mixture of straight-chain saturated carboxylic acids having a chain length of 28 to 32 carbon atoms) or low molecular weight polyethylene wax or low molecular weight polypropylene wax. For example, the lubricant can be a salt of stearic acid, such as aluminum stearate, zinc stearate or calcium stearate. In one embodiment, the lubricant includes one or more of ethylene bis (hard amide) (EBS), stearyl erucamide, montan wax, polyethylene wax and polypropylene wax. Lubricant is typically present in an amount of 0-5%, such as 0.1-5%, 0.1-4%, 0.1-3%, 1-5% and 1-3%.

[0123] ColorPackage

[0124] The polyamide composition may include a color kit containing a colorant known to those skilled in the art to be compatible with the polyamide composition. Suitable components of the color kit include colorants, carbon black, aniline black, and combinations thereof. Colorants that can be used in the polyamide composition are disclosed in U.S. Patent Application No. 2021 / 0277203, which is incorporated herein by reference in its entirety.

[0125] The concentration of nigrosine in the polyamide composition can be, for example, 0 to 5 wt%, such as 0.1 wt% to 1 wt%, 0.15 wt% to 1.5 wt%, 0.22 wt% to 2.3 wt%, 0.32 wt% to 3.4 wt%, or 0.48 wt% to 5 wt%. In some embodiments, the concentration of nigrosine is 1 wt% to 2 wt%, such as 1 wt% to 1.6 wt%, 1.1 wt% to 1.7 wt%, 1.2 wt% to 1.8 wt%, 1.3 wt% to 1.9 wt%, or 1.4 wt% to 2 wt%. In terms of upper limits, the nigrosine concentration can be less than 5 weight percent, for example, less than 3.4 weight percent, less than 2.3 weight percent, less than 2 weight percent, less than 1.9 weight percent, less than 1.8 weight percent, less than 1.7 weight percent, less than 1.6 weight percent, less than 1.5 weight percent, less than 1.4 weight percent, less than 1.3 weight percent, less than 1.2 weight percent, less than 1.1 weight percent, less than 1 weight percent, less than 0.71 weight percent, less than 0.48 weight percent, less than 0.32 weight percent, less than 0.22 weight percent, or less than 0.15 weight percent. In terms of lower limits, the nigrosine concentration can be greater than 0.1 wt %, such as greater than 0.15 wt %, greater than 0.22 wt %, greater than 0.32 wt %, greater than 0.48 wt %, greater than 0.71 wt %, greater than 1 wt %, greater than 1.1 wt %, greater than 1.2 wt %, greater than 1.3 wt %, greater than 1.4 wt %, greater than 1.5 wt %, greater than 1.6 wt %, greater than 1.7 wt %, greater than 1.8 wt %, greater than 1.9 wt %, greater than 2 wt %, greater than 2.3 wt % or greater than 3.4 wt %. Lower concentrations, such as less than 0.1 wt %, and higher concentrations, such as greater than 5 wt %, are also envisioned. In some cases, the nigrosine is provided in a masterbatch, and the nigrosine concentration in the masterbatch and the resulting composition can be easily calculated.

[0126] The concentration of carbon black in the polyamide composition can be, for example, 0 to 5 weight %, for example, 0.1 weight % to 1.05 weight %, 0.15 weight % to 1.55 weight %, 0.22 weight % to 2.29 weight %, 0.32 weight % to 3.38 weight %, or 0.48 weight % to 5 weight %. In some embodiments, the concentration of carbon black is 0.2 weight % to 0.8 weight %. In terms of upper limits, the carbon black concentration can be less than 5 weight %, for example, less than 3.4 weight %, less than 2.3 weight %, less than 1.5 weight %, less than 1 weight %, less than 0.71 weight %, less than 0.48 weight %, less than 0.32 weight %, less than 0.22 weight %, or less than 0.15 weight %. In some embodiments, the carbon black concentration is less than 3 weight %. In terms of lower limits, the carbon black concentration can be greater than 0.1 wt%, such as greater than 0.15 wt%, greater than 0.22 wt%, greater than 0.32 wt%, greater than 0.48 wt%, greater than 0.71 wt%, greater than 1 wt%, greater than 1.5 wt%, greater than 2.3 wt%, or greater than 3.4 wt%. Lower concentrations, such as less than 0.1 wt%, and higher concentrations, such as greater than 5 wt%, are also contemplated.

[0127] Nucleating agent

[0128] The polyamide composition may include one or more nucleating agents known to those skilled in the art to be compatible with polyamide compositions. If present, nucleating agents are typically present in small amounts to further improve transparency and oxygen barrier and enhance oxygen barrier. Typically, these agents are insoluble high melting point species that provide a surface for initiating crystallites. By incorporating nucleating agents, more crystals are initiated, which are smaller in nature. More crystallites or higher % crystallinity are associated with greater enhancement / higher tensile strength and a more tortuous oxygen flux path (increased barrier); smaller crystallites reduce light scattering, which is associated with improved transparency. Suitable nucleating agents include calcium fluoride, calcium carbonate, talc, PA 2,2, and combinations thereof.

[0129] Advantageously, the polyamide composition exhibits suitable transparency and / or oxygen barrier properties without requiring larger amounts of nucleating agents. In some embodiments, the polyamide composition of any of the preceding claims, wherein the polyamide composition comprises less than 2.2 wt% of a nucleating agent, e.g., less than 2.0 wt%, less than 1.8 wt%, less than 1.5 wt%, less than 1.2 wt%, less than 1.0 wt%, less than 0.8 wt%, less than 0.5 wt%, less than 0.3 wt%, or less than 0.1 wt%.

[0130] As used herein, "greater than" and "less than" limits may also include the numbers associated with them. 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 wording 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."

[0131] The components mentioned herein may be considered optional. In some cases, the disclosed compositions may explicitly exclude one or more of the above-mentioned components from this section, such as through the wording of the claims. For example, the wording of the claims may be modified to indicate that the disclosed compositions, methods, etc. do not use or include one or more of the above-mentioned components, e.g., that the composition does not include carbon black.

[0132] Molded products

[0133] The present disclosure also relates to articles comprising polyamide compositions. Articles can be produced, for example, by conventional injection molding, extrusion molding, blow molding, press molding, compression molding, or gas-assisted molding techniques. Molding methods 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 those for electrical and electronic applications (such as, but not limited to, circuit breakers, junction boxes, connectors, etc.), automotive applications (such as, but not limited to, air handling systems, radiator end tanks, fans, shrouds, etc.), furniture and appliance components, and wire positioning devices, such as cable ties.

[0134] Particular uses of the polyamide compositions relate to their use in low-temperature applications. Articles used in low-temperature applications include fasteners, circuit breakers, junction boxes, connectors, automotive parts, furniture parts, appliance parts, cable ties, sporting equipment, gun stocks, window insulation strips, aerosol valves, food packaging films, automotive / vehicle parts, textiles, industrial fibers, carpets, or electrical / electronic components. Cable ties, such as those used in electrical installations, are particularly suitable for use with the disclosed polyamide compositions.

[0135] Performance characteristics

[0136] The polyamide compositions described above exhibit surprising performance results. For example, the polyamide compositions maintain comparable or better tensile properties, molding cycle times (loop strength), and flame retardancy than known conventional polyamide compositions, such as PA66, while providing improved cold-weather installation performance (lower failure rates). These performance parameters are exemplary, and the examples support other performance parameters contemplated by the present disclosure.

[0137] tensile strength

[0138] In one embodiment, the polyamide composition exhibits a tensile strength of at least 50 MPa, e.g., at least 55 MPa, at least 60 MPa, at least 70 MPa, at least 80 MPa. In terms of ranges, the tensile strength may be from 50 MPa to 150 MPa, e.g., from 60 MPa to 125 MPa, from 70 MPa to 100 MPa, from 75 MPa to 95 MPa, or from 80 MPa to 95 MPa.

[0139] Typically, tensile strength measurements can be performed according to ISO 527-1 (2019), and Charpy notched impact energy loss of polyamide compositions can be measured using standard procedures such as ISO 179-1 (2010).

[0140] Interlocking strength

[0141] The loop strength measurement is an Instron-based test in which a cable tie is tightened around a mandrel attachment that opens at a constant rate and the force is measured in lbs. The force required to break the cable tie is the reported metric. An acceptable ISO specification for the loop test is ISO 527. In some embodiments, the polyamide composition exhibits an improved loop strength measured at 23°C of at least 70 lbf (pounds force), e.g., at least 80 lbf, at least 90 lbf, or at least 95 lbf. In terms of ranges, the loop strength may be 50-150 lbf, 60-125 lbf, 70-110 lbf, or 80-100 lbf.

[0142] Injection molding

[0143] Improved injection molding results indicate that the polyamide compositions of the present invention can be processed at lower temperatures to provide better molecular weight retention, which further improves performance attributes such as strength and toughness. Another advantage of low injection pressure or improved flow is lower processing temperatures and higher molecular weight retention, which in turn provides better part toughness and service life.

[0144] Molding cycle time

[0145] Molding cycle time is the time it takes to complete one injection molding cycle. This process involves injecting molten polymer into the mold cavity, cooling the polymer, opening the mold, and ejecting the part. Polymer characteristics that strongly indicate cycle time are (1) the injection pressure or fluidity of the polymer, (2) how quickly the polymer crystallizes, and (3) the surface lubricity required to efficiently eject the part.

[0146] Flammability

[0147] In certain embodiments, the polyamide composition exhibits a V-2 flammability rating at various test thicknesses. Under the UL94 standard, the following requirements need to be met to achieve a V-2 rating: (1) after the test flame is applied, the specimen does not exhibit flaming combustion for more than 30 seconds; (2) for 10 flame applications for each set of 5 specimens, the total flaming combustion time may not exceed 250 seconds; (3) the specimen does not flamingly burn or burn hot to the fixture; (4) the specimen can drip flaming particles to ignite dry, degreased medical cotton located 300 mm below the specimen; and (5) the specimen may not have a burning hot lasting more than 60 seconds after the test flame is removed for the second time.

[0148] Flammability tests were performed according to the UL94 standard on samples of various thicknesses (0.4, 0.75, 1.5 and 3.0 mm).

[0149] Installation test

[0150] In some embodiments, the polyamide composition formed into a cable ties exhibits comparable room temperature installation performance and excellent cold weather installation performance as measured by failure rate.

[0151] The performance of cable ties can be tested using various techniques, such as those described in Underwriters Laboratory (UL) Standard No. 62275, which describes, for example, how to install cable ties.

[0152] The cable ties are injection molded from a polyamide composition and sealed in moisture-proof packaging to keep them "dry as molded". The cable ties are then manually installed on a steel mandrel using an installation gun (installation tool) with adjustable tensioning capability. The installation gun is calibrated to deliver approximately 35 to 37 lbs of tension during installation, and the excess "tail" is then cut off from the cable tie. The installation of the cable tie is considered successful if the assembled cable tie is installed without any cracks and remains intact after installation. Therefore, the installation test is a pass-fail type test, where the success rate (the percentage of cable ties that pass the installation test) is a measure of the toughness of the polyamide composition. Installation can be carried out at 23°C, 10-20% relative humidity (room temperature installation performance) and -40°C, 10-20% relative humidity (cold climate installation performance).

[0153] The polyamide composition unexpectedly exhibits cold weather cable tie installation performance failure rates of less than 20%, such as less than 15%, less than 10%, less than 5%, and less than 1%.

[0154] Embodiments of the present invention therefore relate to polyamide compositions, such as cable ties, having a tensile strength greater than 60 MPa, a flame retardancy rating of V-2 or higher, and / or a cold weather cable tie installation performance failure rate of less than 20%, such as less than 15%, less than 10%, less than 5%, and less than 1%. This combination has not been possible with impact-modified or standard PA66 molding grades.

[0155] Another embodiment relates to a method for improving low-temperature properties in a polyamide composition. The method comprises the steps of adding an elastomer concentrate to a base polymer to produce a modified polyamide composition having improved low-temperature properties. The elastomer concentrate comprises 20-80 wt. % of an elastomeric aliphatic polyether having a molecular weight of 400-4000 g / mol and 80-20 wt. % of a concentrate polyamide.

[0156] The elastomer concentrate, elastomeric aliphatic polyether, and concentrate polyamide in this method involve the same components as described above; the articles, such as cable ties, using the polyamide composition are the same as those described above; and the improved properties of the polyamide composition are the same as those described above. Example

[0157] Example 1 - Polyetherdiamine

[0158] The following polyamide compositions were prepared by polymerization in a 2 L autoclave using a high solids process (solids content > 80 wt %). Table 1 reports the components of each example. In a beaker, the diacid (adipic acid and / or dodecanedioic acid) was weighed out. In a separate beaker, a 50% aqueous solution of hexamethylenediamine (HMD) was prepared. Finally, in another beaker, the polyether diamine ( HT1100). An antioxidant (phenolic - NA281 - Antioxidant 1076) and a sodium hypophosphite catalyst (NA047) were also added to the autoclave. The components were not mixed during addition but were layered in the following order: HMD, dodecanedioic acid or caprolactam, adipic acid, antioxidant and catalyst additives, and polyetherdiamine. After the desired weights of all components were obtained, the materials were added to an autoclave vessel equipped with stirring and assembled on a polymerization apparatus equipped with nitrogen, pressurization, and electrical heating. Before stirring began, the reaction mixture (>80 wt% solids) was heated to above 130°C under a slightly elevated pressure of approximately 18.03 atm (265 psia); preheating before stirring / agitation homogenizes the diacid and polyetherdiamine components, but pre-stirring was found to result in a two-phase system and unsuccessful polymerization. After the temperature exceeds 130° C., stirring is initiated at a pressure of about 17.01 atm to about 18.71 atm (250-275 psia) and the reaction mixture is heated over 45 to 90 minutes to a peak temperature of 230-250° C. The pressure is then reduced over a period of 15 to 90 minutes while maintaining the target temperature between 240° C. and 260° C. The reaction is held at a reduced pressure of about 0.34 atm to about 0.68 atm (5-10 psia) for 30 to 240 minutes, depending on the desired molecular weight, prior to extrusion and pelletization using nitrogen head pressure to push the polymer out of the die orifice.

[0159] Table 1 reports the recipes for making the polymers with different amounts of polyetherdiamine. Examples 1a, 1b, 1c and 1d contain 40% polyetherdiamine, while Examples 1e, 1f, 1g and 1h contain 50% polyetherdiamine. Table 1 reports the molar amounts.

[0160]

[0161]

[0162] Thermal properties, melting point (Tm) and crystallization temperature (Tc) and molecular weight of these examples are reported in

[0163] Table 2.

[0164]

[0165] *Example 1c was repeated by reducing the processing time.

[0166] For injection molding, the molecular weights of Examples 1b, 1e, 1f, and 1g are particularly suitable, while for monofilament extrusion applications, Example 1c is acceptable.

[0167] Example 2 - Polyethylene oxide diamine

[0168] The following polyamide compositions were prepared: PA66 control (Comparative Example A). Impact modified (IM) controls (Comparative Example B and Comparative Example C), which were prepared with Fusabond TM PA66 raw materials compounded with 493 (anhydride modified ethylene copolymer), maleated polyethylene and common lubricants. The unfilled PA66 polymer control (Comparative Example D) at 48RV was compounded with EBS wax and aluminum distearate and CuI / KI heat stabilizer with about 100 ppm copper.

[0169] Terpolymer A (Ex. 2A-2D) contains 45% polyethylene oxide diamine with a molecular weight of 1700 g / mol in a 55% PA66 / PA6 copolymer. Terpolymer B (Ex. 3) contains 45% polytetramethyl ether diamine with a molecular weight of 1100 g / mol in a 55% PA66 / PA610 copolymer. Terpolymer C (Ex. 4) contains PA66 and PA612 and 50% HT1100.

[0170] Terpolymers A and B were blended with PA66 homopolymer in various amounts as shown below (80%-93.5% PA66 homopolymer). Terpolymer C was blended with the PA66 homopolymer of Comparative Example D in an amount of 10% based on the weight of the PA66 homopolymer.

[0171] The composition was then formed into a cable tie as described above and tested for the following properties: cable tie installation performance, interlock strength, and flammability at -40°C, 20% RH. The results are shown in Table 3 below.

[0172]

[0173]

[0174] As seen in Table 1, Examples 2-4 exhibit improved flammability in one or more flammability tests at 0.4 mm, 0.75 mm, 1.5 mm, and 3 mm compared to the comparative examples (including the PA66 control and the IM control). Examples 2C and 2D exhibit improved flammability at all four thicknesses. In Example 4, the % Installation Test is reduced compared to Comparative Example D while maintaining excellent interlock strength and improved flammability.

[0175] Additionally and unexpectedly, Examples 2 and 3 exhibited improved failure rates for cable tie installation performance at low temperatures. 110 cable ties from each formulation were installed using the above procedure and observed for cracking during installation, which was then used to calculate the % failure rate. In some cases, the examples of the present invention exhibited failure rates of less than 10% and less than 5%.

[0176] Additional performance comparisons can be readily derived from Table 3.

[0177] The injection molding properties, specifically injection pressure and cycle time, were also measured for the same compositions disclosed in Table 3. The results are shown in Table 4.

[0178]

[0179]

[0180] As can be seen in Table 4, for injection molding, Examples 2 and 3 exhibited an average molding cycle time reduction of approximately 10-15% compared to the neat grade (control) and the impact-modified grade. For injection molding, Examples 2 and 4 also exhibited an injection pressure reduction of approximately 10-20% compared to the neat grade. These two injection molding results demonstrate that the polyamide compositions of the present invention can be processed at lower temperatures and have better molecular weight retention than the neat grade and the impact-modified grade, which further improves performance attributes such as strength and toughness.

[0181] Implementation Plan

[0182] The following embodiments are contemplated. All combinations of features and embodiments are contemplated.

[0183] Embodiment 1: A polyamide composition comprising: a base polyamide, and an elastomer concentrate comprising: (a) 20-80 wt% of an elastomeric aliphatic polyether having a molecular weight of 400-4000 g / mol; and (b) 80-20 wt% of a concentrate polyamide.

[0184] Embodiment 2: The embodiment of embodiment 1, wherein the elastomeric aliphatic polyether comprises a compound of the formula:

[0185]

[0186] wherein: each n is 1-5; each x is 1-50; and y is 0-2.

[0187] Embodiment 3: The embodiment of embodiment 1, wherein the elastomeric aliphatic polyether is polytetramethyl ether diamine.

[0188] Embodiment 4: The embodiment of embodiment 1, wherein the elastomeric aliphatic polyether is polyethylene oxide diamine.

[0189] Embodiment 5: The embodiment of embodiment 2, wherein n is 3 and the elastomeric aliphatic polyether has a molecular weight of 500-1500 g / mol.

[0190] Embodiment 6: The embodiment of embodiment 2, wherein n is 1 and the elastomeric aliphatic polyether has a molecular weight of 1500-2500 g / mol.

[0191] Embodiment 7: The embodiment of embodiment 2 wherein y is 0 and the elastomeric aliphatic polyether is a diamine.

[0192] Embodiment 8: The embodiment of embodiment 1, wherein the concentrate polyamide comprises PA66; PA6; PA610; PA611, PA612; PA10; PA11; or PA12; or a combination thereof.

[0193] Embodiment 9: The embodiment of embodiment 1, wherein the elastomer concentrate comprises a copolymer / terpolymer comprising elastomer repeat units and polyamide repeat units, wherein the polyamide repeat units comprise PA66; PA6; PA610; PA611, PA612; PA10; PA11; or PA12; or a combination thereof.

[0194] Embodiment 10: The embodiment of embodiment 1, wherein the elastomer concentrate comprises a terpolymer of PA66, PA6, and an elastomeric aliphatic polyether.

[0195] Embodiment 11: The embodiment of embodiment 1, wherein the elastomer concentrate comprises a terpolymer of PA66, PA612 and an elastomeric aliphatic polyether, or a terpolymer of PA66, PA610 and an elastomeric aliphatic polyether.

[0196] Embodiment 12: The embodiment of embodiment 1, wherein the polyamide composition comprises 5-20 wt% elastomer concentrate and 80-95 wt% base polyamide.

[0197] Embodiment 13: The embodiment of embodiment 1, wherein the base polyamide comprises PA66 homopolymer.

[0198] Embodiment 14: The embodiment of embodiment 1, further comprising one or more lubricants.

[0199] Embodiment 15: The embodiment of embodiment 14, wherein the lubricant is selected from ethylene bis(stearyl amide) (EBS), stearyl erucamide, montan wax, polyethylene wax, polypropylene wax, and combinations thereof.

[0200] Embodiment 16: The embodiment of embodiment 1, further comprising one or more thermal stabilizers.

[0201] Embodiment 17: The embodiment of embodiment 1, further comprising a colorant, carbon black and / or aniline black.

[0202] Embodiment 18: The embodiment of embodiment 1, further comprising one or more nucleating agents.

[0203] Embodiment 19: The embodiment of embodiment 18, wherein the nucleating agent is selected from the group consisting of calcium fluoride, calcium carbonate, talc, PA 2,2, and combinations thereof.

[0204] Embodiment 20: An article for low temperature applications, wherein the article is formed from the polyamide composition of embodiment 1, wherein the article is used for fasteners, circuit breakers, junction boxes, connectors, automotive parts, furniture parts, appliance parts, cable ties, sporting equipment, gun stocks, window insulation strips, aerosol valves, food film packaging, automotive / vehicle parts, textiles, industrial fibers, carpets, or electrical / electronic parts.

[0205] Embodiment 21: Embodiment 20 of embodiment 20, wherein the article is a cable tie.

[0206] Embodiment 22: The embodiment of embodiment 20, wherein the article exhibits a tensile strength greater than 60 MPa and a flame retardancy rating of V-2 or higher.

[0207] Embodiment 23: The embodiment of embodiment 21, wherein the article exhibits a cold weather cable tie installation performance failure rate of less than 10%.

[0208] Embodiment 24: A method for improving the low temperature properties of a polyamide composition, comprising the step of adding an elastomer concentrate to a base polymer to produce a modified polyamide composition with improved low temperature properties, the elastomer concentrate comprising: (a) 20-80 wt% of an elastomeric aliphatic polyether having a molecular weight of 400-4000 g / mol; and (b) 80-20 wt% of the concentrate polyamide.

[0209] Embodiment 25: The embodiment of embodiment 24, wherein the polyamide composition is a cable tie and the improved low temperature performance is demonstrated by a cold weather cable tie installation performance failure rate of less than 10%.

[0210] Embodiment 26: The embodiment of embodiment 21, wherein the polyamide composition has a tensile strength of 60 MPa or higher, and a flame retardancy rating of V-2 or higher.

[0211] Embodiment 27: An elastomeric concentrate comprising (a) 20-80 wt% of an elastomeric aliphatic polyether having a molecular weight of 400-4000 g / mol; and (b) 80-20 wt% of a concentrate polyamide.

[0212] Embodiment 28: A method for producing a polyamide elastomer, comprising: feeding a salt solution having a solids content greater than or equal to 80% into a reactor having a phosphorus-containing catalyst, wherein the phosphorus-containing catalyst has a phosphorus content of 5 to 1000 parts per million based on the total weight of the catalyst; feeding a polyetheramine into the reactor; and reducing the pressure in the reactor, for example, to less than or equal to 2 atm, upon reaching a target temperature, for example, in the range of 240°C to 260°C, to polymerize the salt solution and the polyetheramine to form the polyamide elastomer.

[0213] Embodiment 29: The method of Embodiment 28, wherein the pressure in the reactor is reduced to 0.1 atm to 2 atm.

[0214] Embodiment 30: The method of Embodiment 28 and / or 29, wherein the polyamide elastomer has a weight average molecular weight greater than or equal to 12,000 g / mol.

[0215] Embodiment 31: The method of Embodiments 28-30, wherein the polyamide elastomer has a melting temperature greater than or equal to 200°C.

[0216] Embodiment 32: The method of Embodiments 28-31, wherein the polyamide elastomer has a melting temperature of 200°C to 280°C.

[0217] Embodiment 33: The method of Embodiments 28-32, wherein the salt solution has a solids content greater than or equal to 85%.

[0218] Embodiment 34: The method of Embodiments 28-33, wherein the salt solution comprises 10 to 90 weight percent of the diacid having 6 or fewer carbon atoms and 90 to 10 weight percent of the diamine having 6 or fewer carbon atoms, each weight percent based on the total weight of the salt solution.

[0219] Embodiment 35: The method of Embodiments 28-34, wherein the phosphorus-containing catalyst is phosphoric acid, phosphorous acid, hypophosphorous acid, phenylphosphonic acid, phenylphosphinic acid, and / or salts thereof.

[0220] Embodiment 36: The method of Embodiments 28-35, wherein the polyetheramine contains at least 70% primary amines based on the total number of amines in the elastomeric aliphatic polyether diamine.

[0221] Embodiment 37: The method of Embodiments 28-36, wherein the polyetheramine is a polyethermonoamine, polyetherdiamine, polyethertriamine, or polyethertetramine.

[0222] Embodiment 38: The method of Embodiments 28-37, wherein the polyetheramine is polytetramethyl ether diamine.

[0223] Embodiment 39: A method for producing a polyamide elastomer, comprising: supplying a salt solution into a reactor having a phosphorus-containing catalyst, wherein the phosphorus-containing catalyst has a phosphorus content of 5 to 1000 parts per million based on the total weight of the catalyst; reducing the water content in the reactor; supplying a polyetheramine into the reactor after the water content is reduced; and polymerizing the salt solution and the polyetheramine at a temperature of, for example, 240° C. to 260° C. under reduced pressure to form a polyamide elastomer.

[0224] Embodiment 40: The method of Embodiment 39, wherein the reduced pressure is less than or equal to 2 atm.

[0225] Embodiment 41: The method of Embodiment 39, wherein the reduced pressure is from 0.1 atm to 2 atm.

[0226] Embodiment 42: The method of Embodiments 39-41, wherein the polyamide elastomer has a weight average molecular weight greater than or equal to 12,000 g / mol.

[0227] Embodiment 43: The method of Embodiments 39-42, wherein the polyamide elastomer has a melting temperature greater than or equal to 200°C.

[0228] Embodiment 44: The method of Embodiments 39-43, wherein the polyamide elastomer has a melting temperature of 200°C to 280°C.

[0229] Embodiment 45: The method of Embodiments 39-44, wherein the water content is reduced by at least 30%.

[0230] Embodiment 46: The method of Embodiments 39-45, wherein the salt solution comprises 10 to 90 weight percent of the diacid having 6 or fewer carbon atoms and 90 to 10 weight percent of the diamine having 6 or fewer carbon atoms, each weight percent based on the total weight of the salt solution.

[0231] Embodiment 47: The method of Embodiments 39-46, wherein the phosphorus-containing catalyst is hypophosphorous acid and its salts.

[0232] Embodiment 48: The method of Embodiments 39-47, wherein the polyetheramine has 70% primary amines based on the total number of amines in the elastomeric aliphatic polyether diamine.

[0233] Embodiment 49: The method of Embodiments 39-48, wherein the polyetheramine is a polyethermonoamine, polyetherdiamine, polyethertriamine, or polyethertetramine.

[0234] Embodiment 50: The method of Embodiments 39-49, wherein the polyetheramine is polytetramethyl ether diamine.

[0235] Although the present invention has been described in detail, it will be readily apparent to those skilled in the art that modifications within the spirit and scope of the present invention will be apparent based on the above discussion, relevant knowledge in the art, and the references discussed above in connection with "background" and "detailed description" (the disclosures of which are incorporated herein by reference in their entirety). Furthermore, it will be understood that aspects of the present invention and portions of the various embodiments and the various features listed below and / or in the appended claims may be combined or interchanged in whole or in part. In the previous descriptions of the various embodiments, those embodiments with reference to another embodiment may be appropriately combined with the other embodiments as recognized by those skilled in the art. Furthermore, it will be appreciated that the foregoing descriptions are by way of example only and are not intended to be limiting.

Claims

1. A method for producing a polyamide elastomer, comprising: feeding a salt solution having a solid content of greater than or equal to 80% into a reactor having a phosphorus-containing catalyst having a phosphorus content of 5 to 1000 parts per million based on the total weight of the catalyst; feeding a polyetheramine into a reactor; and Once the target temperature is reached the pressure in the reactor is reduced to allow the salt solution and polyetheramine to polymerize to form the polyamide elastomer. 2 . The method of claim 1 , wherein the target temperature is in the range of 240° C. to 260° C.

3. The process according to claim 1, wherein the pressure in the reactor is reduced to less than or equal to 2 atm.

4. The process according to any one of claims 1 to 3, wherein the pressure in the reactor is reduced to 0.1 atm to 2 atm.

5. The method of any one of claims 1-4, wherein the polyamide elastomer has a weight average molecular weight greater than or equal to 12,000 g / mol.

6. The method according to any one of claims 1 to 5, wherein the polyamide elastomer has a melting temperature of 200 to 280°C.

7. The method of any one of claims 1-6, wherein the salt solution has a solids content greater than or equal to 85%.

8. The method of any one of claims 1 to 7, wherein the salt solution comprises 10 to 90 weight percent of a diacid having 6 or fewer carbon atoms and 90 to 10 weight percent of a diamine having 6 or fewer carbon atoms, each weight percent based on the total weight of the salt solution.

9. The method according to any one of claims 1 to 7, wherein the elastomer concentrate comprises a terpolymer of PA66 and PA612.

10. The process according to any one of claims 1 to 9, wherein the phosphorus-containing catalyst is phosphoric acid, phosphorous acid, hypophosphorous acid, phenylphosphonic acid, phenylphosphinic acid and / or salts thereof.

11. The process according to any one of claims 1 to 10, wherein the polyetheramine contains at least 70% of primary amines, based on the total number of amines in the elastomeric aliphatic polyetherdiamine.

12. The method according to any one of claims 1 to 11, wherein the polyetheramine is a polyethermonoamine, a polyetherdiamine, a polyethertriamine or a polyethertetramine.

13. The method according to any one of claims 1 to 11, wherein the polyetheramine is polytetramethyl ether diamine.

14. The process according to any one of claims 1 to 13, comprising reducing the water content in the reactor, wherein the polyetheramine is fed into the reactor after the water content has been reduced.

15. The method of claim 14, wherein the water content is reduced by at least 30%.

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