Non-halogenated flame retardant polyamide composition

Abstract

Disclosed herein is a flame retardant polyamide composition consisting of a polyamide, a non-halogenated flame retardant, a synergist, glass fibers, and one or more additives including a flow modifier, a heat stabilizer, a filler, or a combination thereof, where the synergist includes a phosphorus-containing compound, where the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8. The invention also relates to a method of forming a molded product. The composition provided by the invention achieves improved effects in the aspects of manufacturing cost, processability and product properties.

Description

[0001] This application is a divisional application of the international application number PCT / US2020 / 012469, entitled “Non-halogenated flame retardant polyamide composition”, filed by Ascend Functional Materials Operations Co., Ltd. on January 7, 2020. The date on which the international application PCT / US2020 / 012469 entered the Chinese national phase is July 1, 2021, and the national application number is 202080007773.6.

[0002] Priority declaration

[0003] This application claims priority to U.S. Provisional Application No. 62 / 789,223, filed on January 7, 2019, the entire contents and disclosure of which are incorporated herein by reference. Technical Field

[0004] The present disclosure relates to devices and methods that can be used in electrical and electronic applications, including connectors, relays, junction boxes, motors, wall panels, lamps, circuit breakers, switches and sensors, and other applications. Non-halogenated Flame retardant polyamide compositions (non-halogenated flame retardant polyamide compositions). Background Art

[0005] Flame retardant compositions, including compositions comprising polymer compositions, are known in the art and are used for various purposes, including those related to electrical and electronic applications. Known compositions include various synergists, flow modifiers and polymers and often suffer from problems with thermal stability and flowability during the manufacturing process. Another problem is that during the manufacturing process, the molecular weight of the composition grows, so that the viscosity increases and the flow decreases, which makes the recycling of the final product difficult. Although flow modifiers may be included to address some of these problems, such flow modifiers result in increased costs and may also have an adverse effect on the required viscosity.

[0006] As an example, US Publication No. 2013 / 0244527A1 proposes a flame retardant fiber including partially aromatic polyamide and a non-halogen flame retardant additive.

[0007] US Patent No. 8,234,296 generally relates to halogen-free flame retardant synthetic resin compositions containing specific (poly)phosphate compounds in combination with layered silicates.

[0008] U.S. Patent No. 8,940,818 generally relates to halogen-free flame retardants for incorporation into polymer matrices, wherein the flame retardant contains at least ammonium polyphosphate and / or its derivatives and oligomeric or polymeric 1,3,5-triazine derivatives or mixtures thereof and at least one compound selected from monozinc phosphate, zinc borate, trizinc phosphate, zinc pyrophosphate, zinc polyphosphate, zinc hydroxystannate, zinc stannate, boron phosphate, monoaluminum phosphate, trialuminum phosphate, aluminum metaphosphate and mixtures thereof, precondensed melamine derivatives, melamine salts and adducts, ethylenediamine phosphates, piperazine phosphates, piperazine polyphosphates, 1,3,5-trihydroxyethyl isocyanurate, 1,3,5-triglycidyl isocyanurate and triallyl isocyanurate.

[0009] U.S. Patent No. 8,362,119 generally relates to thermoplastic molding compositions comprising an unbranched thermoplastic polyamide, a phosphinate or diphosphinate, a nitrogen-containing flame retardant combination and at least one oxygen-containing, nitrogen-containing or sulfur-containing metal compound, and also to the production of the inventive molding compositions and their use for the production of fibers, foils and moldings of any type.

[0010] U.S. Publication No. 2007 / 0054992 generally relates to a flame retardant resin composition having excellent flame retardancy and low water absorption properties and exhibiting small dimensional changes and small reduction in insulation properties. The flame retardant resin composition contains: (A) an aliphatic polyamide resin; (B) an aromatic polyamide resin; (C) a specific flame retardant; and (D) an inorganic filler.

[0011] Although various compositions and materials have been proposed, conventional products are far from ideal in terms of manufacturing cost, processability and product properties. Summary of the invention

[0012] Overview

[0013] In some embodiments, the present disclosure relates to a flame retardant polyamide composition comprising a polyamide, a non-halogenated flame retardant, and a synergist, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8. The composition may further comprise one or more additives. The one or more additives may comprise a flow modifier, a thermal stabilizer, a filler, or a combination thereof. The weight average molecular weight of the composition may be 20,000 to 100,000. The z-average molecular weight may be 50,000 to 600,000. The composition may comprise 40 to 70 weight % nylon 6,6 based on the total weight of the composition. The composition may comprise 5 to 25 weight % non-halogenated flame retardant based on the total weight of the composition. The composition may comprise 0.1 to 15 weight % synergist based on the total weight of the composition. The composition may further comprise 5 to 45 weight % glass fiber based on the total weight of the composition. The composition may comprise 0.05 to 5 weight % thermal stabilizer based on the total weight of the composition. The non-halogenated flame retardant may comprise a phosphorus flame retardant. The synergist may comprise a polyphosphate. In some aspects, the synergist may comprise melamine polyphosphate. The polyamide may comprise less than 50 μeq / gram amine end groups. The polyamide may comprise nylon 6,6. In some aspects, the polyamide comprises nylon 6,6 in combination with at least one other polymer.

[0014] In some embodiments, the present disclosure relates to a molded flame retardant polyamide product formed from a composition comprising a polyamide, a non-halogenated flame retardant and a synergist, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8. The composition may further include one or more additives. The one or more additives may include a flow modifier, a thermal stabilizer, a filler, or a combination thereof. The weight average molecular weight of the composition may be 20,000 to 100,000. The z-average molecular weight may be 45,000 to 600,000. The composition may include 40 to 70 weight % nylon 6,6 based on the total weight of the composition. The composition may include 5 to 25 weight % non-halogenated flame retardant based on the total weight of the composition. The composition may include 0.1 to 15 weight % synergist based on the total weight of the composition. The composition may further include 5 to 45 weight % glass fiber based on the total weight of the composition. The composition may include 0.05 to 5 weight % thermal stabilizer based on the total weight of the composition. The non-halogenated flame retardant may include a phosphorus flame retardant. The synergist may comprise a polyphosphate. In some aspects, the synergist may comprise melamine polyphosphate. The polyamide may comprise less than 50 μeq / gram amine end groups. In some aspects, the polyamide comprises nylon 6,6 in combination with at least one other polymer.

[0015] In some embodiments, the present disclosure relates to a method for forming a molded product, comprising: a) forming a polyamide having a carboxylic acid / amine end group ratio greater than 1.8; b) compounding the polyamide with a non-halogenated flame retardant and a synergist comprising a phosphorus-containing compound to form a compounded composition; and c) molding the compounded composition to form a molded product. The composition may further comprise one or more additives. The one or more additives may comprise a flow modifier, a thermal stabilizer, a filler, or a combination thereof. The weight average molecular weight of the product may be from 20,000 to 100,000. The z-average molecular weight of the product may be from 45,000 to 600,000. The product may comprise 40 to 70% by weight of polyamide based on the total weight of the product. The product may comprise 5 to 25% by weight of non-halogenated flame retardant based on the total weight of the product. The product may comprise 0.1 to 15% by weight of synergist based on the total weight of the product. The product may further comprise 5 to 45% by weight of glass fiber based on the total weight of the product. The composition may include 0.05 to 5 weight percent thermal stabilizer based on the total weight of the composition. The non-halogenated flame retardant may include a phosphorus flame retardant. The synergist may include a polyphosphate. In some aspects, the synergist may include melamine polyphosphate. In some aspects, the polyamide includes nylon 6,6 combined with at least one other polymer.

[0016] In some embodiments, the present disclosure relates to a flame retardant polyamide composition comprising: 40 to 70 weight percent polyamide; 5 to 25 weight percent non-halogenated flame retardant; 0.1 to 15 weight percent synergist; 5 to 45 weight percent glass fiber; and 0.05 to 5 weight percent thermal stabilizer, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8. In some aspects, the polyamide comprises nylon 6,6 in combination with at least one other polymer.

[0017] In some embodiments, the present disclosure relates to a flame retardant polyamide composition comprising: 40 to 70 weight percent of a polyamide; 5 to 25 weight percent of a non-halogenated flame retardant; 0.1 to 15 weight percent of a synergist; and 0.05 to 5 weight percent of a thermal stabilizer, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8. In some aspects, the polyamide comprises nylon 6,6 in combination with at least one other polymer.

[0018] In some embodiments, the present disclosure is directed to a method of controlling the RV of a polyamide, the method comprising: determining a desired RV for the polyamide; adjusting the value of at least one of an amine end group, an inert end group, or a carboxylic acid end group; wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8. In some aspects, the desired RV is at least 20 or at least 35. In some aspects, a polymerization catalyst such as sodium hypophosphite is not included.

[0019] In some embodiments, the present disclosure relates to a flame retardant polyamide composition comprising a polyamide, a non-halogenated flame retardant, and a synergist, wherein the composition satisfies at least one of the following conditions: (a) the weight average molecular weight of the final composition is less than 300% higher than the weight average molecular weight of the starting polyamide resin; (b) the number average molecular weight of the final composition is less than 100% higher than the number average molecular weight of the starting polyamide resin; (c) the Z average molecular weight of the final composition is less than 100% higher than the Z average molecular weight of the starting polyamide resin; (d) the polydispersity index of the final composition is less than 300% higher than the weight average molecular weight of the starting polyamide resin; or (e) the intrinsic viscosity of the final composition is less than 100% higher than the intrinsic viscosity of the starting polyamide resin. DETAILED DESCRIPTION

[0020] Details

[0021] Overview

[0022] The present disclosure relates in part to a flame retardant polyamide composition. The composition may include a polyamide, a flame retardant, and a synergist. The polyamide may include nylon 6,6, which may be present in an amount of 40 to 70 wt % based on the total weight of the composition. Nylon 6,6 may have a carboxylic acid / amine end group ratio of at least 1.8, such as 1.9 to 3. The flame retardant may be non-halogenated and may be present in 5 to 25 wt % based on the total weight of the composition. The synergist may include a phosphorus-containing compound and may be present in 0.1 to 10 wt % based on the total weight of the composition. It has been found that the compositions described herein are thermally stable and have a reduced molecular weight increase during compounding and molding.

[0023] The present inventors have discovered that by utilizing specific polyamides with specific characteristics, particularly controlled amine end groups, compositions with synergistic characteristics are formed. Without being bound by theory, it is speculated that the use of polyamides with reduced reactivity, such as through lower amine end groups, increased inert acetate end groups, and / or increased carboxylic acid end groups, results in improved thermal stability and other desirable characteristics. As an added benefit, the molecular weight of the composition is controlled from initial formation to final compounding and molding.

[0024] The inventors have also discovered that some of the disclosed compositions produce products with reduced metal group plating out and corrosion. These improvements advantageously produce products with improved durability and performance.

[0025] In some aspects, no flow modifier is required to achieve the desired viscosity and flowability of the composition.

[0026] In some embodiments, the composition is prepared and then compounded and molded into a final molded product.

[0027] In some aspects, the molecular weight (Mw, Mn and / or Mz) of the composition can be controlled by means separate or together with the end group ratios described herein. Such means include processing changes, such as changes in moisture content, screw speed and / or screw design. Another means includes using a resin with a relatively low starting Rv, such as an RV of less than 36, such as an RV of 20 to 36.

[0028] Particularly preferred polyamides include nylon 6,6, and copolymers, blends and alloys of nylon 6,6 and nylon 6. Other embodiments include nylon derivatives, copolymers, terpolymers, blends and alloys containing nylon 6,6 or nylon 6 or made of nylon 6,6 or nylon 6, copolymers or terpolymers having the above repeating units, including but not limited to: N6T / 6,6, N612, N6 / 6,6, N6I / 6,6, N11 and N12, where "N" refers to nylon. Another preferred embodiment includes high temperature nylon ("HTN") and blends, derivatives, copolymers or terpolymers containing them. Another preferred embodiment also includes long chain aliphatic polyamides made with long chain diacids and blends, derivatives or copolymers containing them. When a blend of polymers is included, the reactivity of the end groups of all polymers is ideally low. For example, when a blend of polymers is used, the end group ratios described herein can be applied to the polyamide component and any other components (if applicable).

[0029] Composition components

[0030] As described herein, the present disclosure is directed to flame retardant polyamide compositions comprising polyamide (e.g., nylon 6,6) in combination with a non-halogenated flame retardant and a synergist (e.g., a synergist containing a phosphorus-containing compound). Additional components that may be present in the composition are described herein and include, but are not limited to, thermal stabilizers, metals, flow modifiers, fillers, and combinations thereof.

[0031] The composition can be formed by combining the above components and then extruding them through an extruder.

[0032] As described herein, a major advantage of the compositions described herein is that, during the compounding and molding process of the composition, the expected molecular weight is controlled and limited. In some aspects, the initial weight average molecular weight of the polyamide is at least 20,000, such as at least 22,500, at least 25,000 or at least 27,500. In terms of upper limits, the weight average molecular weight of the initial polyamide is 45,000 or less, such as 42,500 or less, 40,000 or less, or 37,500 or less. In terms of range, the weight average molecular weight of the initial polyamide is 20,000 to 45,000, such as 22,500 to 42,500, 25,000 to 40,000 or 27,500 to 37,500. In some aspects, the initial number average molecular weight of the polyamide is at least 10,000, such as at least 12,500, at least 15,000 or at least 17,500. In terms of upper limits, the number average molecular weight of the initial polyamide is 30,000 or less, such as 27,500 or less, 25,000 or less, or 22,500 or less. In terms of ranges, the number average molecular weight of the initial polyamide is 10,000 to 30,000, such as 12,500 to 27,500, 15,000 to 25,000, or 17,500 to 22,500. In some aspects, the initial Z-average molecular weight of the polyamide is at least 30,000, such as at least 35,000, at least 40,000, or at least 45,000. In terms of upper limits, the Z-average molecular weight of the initial polyamide is 70,000 or less, such as 65,000 or less, 60,000 or less, or 55,000 or less. In terms of ranges, the Z average molecular weight of the initial polyamide is 30,000 to 70,000, such as 35,000 to 65,000, 40,000 to 60,000, or 45,000 to 55,000. The polydispersity index of the initial polyamide may be at least 1.2, such as at least 1.3, at least 1.4, at least 1.5, or at least 1.6. In terms of upper limits, the polydispersity index of the initial polyamide may be less than 2, such as less than 1.95, less than 1.9, less than 1.85, or less than 1.8. In terms of ranges, the polydispersity index of the initial polyamide may be from 1.2 to 2, such as from 1.3 to 1.95, 1.3 to 1.9, 1.4 to 1.85, 1.5 to 1.8, or 1.6 to 1.8. The intrinsic viscosity of the initial polyamide in dl / g may be at least 2, such as at least 2.1, at least 2.2, at least 2.3, or at least 2.4. In terms of upper limits, the intrinsic viscosity of the initial polyamide in dl / g may be less than 3, such as less than 2.9, less than 2.8, less than 2.7, or less than 2.6. In terms of ranges, the intrinsic viscosity of the initial polyamide in dl / g may be from 2 to 3, such as from 2.1 to 2.9, from 2.2 to 2.8, from 2.3 to 2.7, or from 2.4 to 2.6.

[0033] After compounding and extrusion or injection molding, the final product may have a weight average molecular weight of at least 20,000, such as at least 25,000, at least 30,000, or at least 35,000. In terms of upper limits, the weight average molecular weight of the final product is 100,000 or less, such as 97,500 or less, 95,000 or less, or 92,500 or less. In terms of range, the weight average molecular weight of the final product is 20,000 to 100,000, such as 25,000 to 97,500, 30,000 to 95,000, or 35,000 to 92,500. In some aspects, the number average molecular weight of the final product is at least 10,000, such as at least 12,500, at least 15,000, or at least 17,500. In terms of upper limits, the number average molecular weight of the final product is 40,000 or less, such as 37,500 or less, 35,000 or less, or 32,500 or less. In terms of ranges, the number average molecular weight of the final product is 10,000 to 40,000, such as 12,500 to 37,500, 15,000 to 35,000, or 17,500 to 32,500. In some aspects, the Z average molecular weight of the final product is at least 30,000, such as at least 35,000, at least 40,000, or at least 45,000. In terms of upper limits, the Z average molecular weight of the final product is 550,000 or less, such as 500,000 or less, 400,000 or less, or 300,000 or less. In terms of ranges, the Z average molecular weight of the final product is 30,000 to 550,000, such as 35,000 to 500,000, 40,000 to 400,000, or 45,000 to 300,000. The polydispersity index of the final product may be at least 1.8, such as at least 1.9, at least 2, or at least 2.1. In terms of upper limits, the polydispersity index of the final product may be less than 4, such as less than 3.85, less than 3.5, or less than 3. In terms of ranges, the polydispersity index of the final product may be 1.8 to 4, such as 1.9 to 3.85, 2 to 3.5, or 2.1 to 3. The intrinsic viscosity of the final product in dl / g may be at least 2, such as at least 2.1, at least 2.2, at least 2.3, or at least 2.4. In terms of upper limits, the final product can have an intrinsic viscosity in dl / g of less than 4, e.g., less than 3.9, less than 3.8, less than 3.7, or less than 3.6. In terms of ranges, the initial polyamide can have an intrinsic viscosity in dl / g of 2 to 4, e.g., 2.1 to 3.9, 2.2 to 3.8, 2.3 to 3.7, or 2.4 to 3.6.

[0034] In terms of increase, the percentage increase in weight average molecular weight from the initial polyamide to the final product may be at least 1%, such as at least 5%, at least 10%, or at least 20%. In terms of upper limits, the percentage increase in weight average molecular weight from the initial polyamide to the final product may be less than 300%, such as less than 250%, less than 200%, or less than 100%. In terms of ranges, the percentage increase in weight average molecular weight from the initial polyamide to the final product may be 1% to 300%, such as 5% to 250%, 10% to 200%, 20 to 150%, or 20% to 100%. In terms of increase, the percentage increase in number average molecular weight from the initial polyamide to the final product may be at least 1%, such as at least 5%, at least 10%, or at least 15%. In terms of upper limits, the percentage increase in number average molecular weight from the initial polyamide to the final product may be less than 100%, such as less than 50%, less than 40%, or less than 35%. In terms of ranges, the percentage increase in number average molecular weight from the initial polyamide to the final product may be 1% to 100%, such as 5% to 50%, 10% to 25%, or 15% to 20%. In terms of increase, the percentage increase in Z average molecular weight from the initial polyamide to the final product may be at least 1%, such as at least 5%, at least 10%, or at least 20%. In terms of upper limits, the percentage increase in Z average molecular weight from the initial polyamide to the final product may be less than 300%, such as less than 250%, less than 200%, or less than 100%. In terms of ranges, the percentage increase in Z average molecular weight from the initial polyamide to the final product may be 1% to 300%, such as 5% to 250%, 10% to 200%, or 20% to 100%. In terms of increase, the percentage increase in polydispersity index from the initial polyamide to the final product may be at least 1%, such as at least 5%, at least 10%, or at least 20%. In terms of upper limits, the percentage increase in polydispersity index from the initial polyamide to the final product may be less than 200%, such as less than 100%, less than 50%, or less than 25%. In terms of ranges, the percentage increase in polydispersity index from the initial polyamide to the final product may be from 1% to 200%, such as 5% to 100%, 10% to 50%, or 20% to 25%. In terms of increase, the percentage increase in weight average molecular weight from the initial polyamide to the final product may be at least 1%, such as at least 5%, at least 10%, or at least 20%. In terms of upper limits, the percentage increase in intrinsic viscosity from the initial polyamide to the final product may be less than 100%, such as less than 75%, less than 50%, or less than 25%. In terms of ranges, the percentage increase in intrinsic viscosity from the initial polyamide to the final product may be from 1% to 100%, such as 5% to 75%, 10% to 50%, or 20% to 25%.

[0035] Non-halogenated flame retardants

[0036] Exemplary non-halogenated flame retardants include phosphorus-containing or melamine-containing flame retardants. Melamine flame retardants are known in the art and include melamine phosphates and melamine cyanurates. Phosphinate flame retardants include those sold by Clariant as diethylaluminum phosphinate, such as OP-1230 and OP-1400 can be used in the compositions described herein. Melamine phosphates include melamine phosphates, dimelamine phosphates, melamine pyrophosphates, melamine polyphosphates, melam polyphosphates, melam polyphosphates, melamine condensation products, or mixtures thereof. Phosphinate flame retardants may be desirable due to their thermal stability in nylon. Other phosphorus flame retardants that can be used in the compositions herein include phosphine oxides, phosphonate oligomers, aluminum phosphites (including V, VI, VII, VIII, etc.), polyphosphazenes, and alkyl-DOPO derivatives. Exemplary phosphazenes are disclosed in U.S. Publication Nos. 2018 / 0072873 and 2018 / 0171112, which are incorporated herein by reference in their entirety, and include phosphazenes of formula (III) or (IV)

[0037]

[0038] Where R 4 and R 4′ Same or different and C1-C 20 -alkyl, C6-C 30 -Aryl, C6-C 30 -Arylalkyl or C6-C 30 -alkyl substituted aryl, and X is a group -N═P(OPh)3 or -N═P(O)OPh, and Y is a group -P(OPh)4 or -P(O)(OPh)2; as component C, 0 to 30% by weight of an inorganic zinc compound, and as component D, 0 to 50% by weight of a nitrogen-containing flame retardant. Components A and B can be used alone or in combination with each other. Components C and D can be used in combination with components A and / or B. Exemplary alkyl-DOPO derivatives are disclosed in U.S. Publication No. 2013 / 0136911, which is incorporated herein by reference in its entirety, and include polycondensates of a) at least one phosphorus-containing monomer and b) at least one ester-forming monomer selected from monovalent or polyvalent alcohols and mixtures thereof, adducts of a) at least one phosphorus-containing monomer selected from a1) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and / or core-substituted DOPO derivatives in a2) unsaturated compounds selected from monovalent and polyvalent carboxylic acids and their anhydrides. Further DOPO derivatives include:

[0039]

[0040] Where R 1 is oxygen, and R 2 and R 3 are independently hydrogen, C1-C 15 Alkyl, C6-C 12 Aryl, C7-C 15 Arylalkyl or C7-C 15 Alkaryl, and wherein m is independently selected from 1-4.

[0041]

[0042]

[0043] wherein R is methyl, ethyl, propyl, butyl, etc.; and

[0044]

[0045] wherein H is replaced by an R group having one or more carbons. The flame retardants listed above can be used alone or in combination with each other.

[0046] In terms of the lower limit, the non-halogenated flame retardant is present in an amount of at least 5 wt %, such as at least 7.5 wt %, at least 10 wt %, or at least 12.5 wt %, based on the total weight of the composition. In terms of the upper limit, the non-halogenated flame retardant is present in an amount of less than 25 wt %, such as less than 22.5 wt %, less than 20 wt %, or less than 17.5 wt %. In terms of range, the non-halogenated flame retardant is present in an amount of 5 to 25 wt %, such as 7.5 to 22.5 wt %, 10 to 20 wt %, or 12.5 to 17.5 wt %.

[0047] Polyamide

[0048] As used herein, polyamide composition and similar terms refer to compositions containing polyamide (including copolymers, terpolymers, polymer blends, alloys and derivatives of polyamide). In addition, " polyamide " used herein refers to a polymer having a polymer having a connection of an amino group of one molecule to a carboxylic acid group of another molecule as a component. In some aspects, polyamide is a component present in a maximum amount. For example, a polyamide containing 40% by weight of nylon 6, 30% by weight of polyethylene and 30% by weight of polypropylene is referred to as polyamide in this article, because the nylon 6 component is present in a maximum amount. In addition, a polyamide containing 20% ​​by weight of nylon 6, 20% by weight of nylon 6,6, 30% by weight of polyethylene and 30% by weight of polypropylene is also referred to as polyamide in this article, because nylon 6 and nylon 6,6 components add up to components present in a maximum amount.

[0049] Exemplary polyamides and polyamide compositions are described in Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 18, pp. 328-371 (Wiley 1982), the disclosure of which is incorporated herein by reference.

[0050] In brief, polyamides are generally known as compounds containing repeating amide groups as an integral part of the main polymer chain. Linear polyamides are of particular interest and can be formed by condensation of difunctional monomers. Polyamides are often referred to as nylons. Although they are generally considered condensation polymers, polyamides are also formed by addition polymerization. This method of preparation is particularly important for some polymers, such as nylon 6, in which the monomers are cyclic lactams. Specific polymers and copolymers and their preparation can be found in the following patents: U.S. Patent Nos. 4,760,129; 5,504,185; 5,543,495; 5,698,658; 6,011,134; 6,136,947; 6,169,162; 7,138,482; 7,381,788; and 8,759,475.

[0051] There are many advantages to using polyamides, especially nylons, in commercial applications. Nylons are generally chemically and temperature resistant, resulting in superior performance over other particles. They are also known to have improved strength, elongation, and abrasion resistance over other polymers. Nylons are also very versatile, allowing them to be used in a variety of applications.

[0052] A particularly preferred class of polyamides for some applications includes those described in Glasscock et al., High Performance Polyamides Fulfill Demanding Requirements for Automotive Thermal Management Components, (DuPont), available online on June 10, 2016,

[0053] High temperature nylons (HTN's) as described in http: / / www2.dupont.com / Automotive / en_US / assets / downloads / knowledg e%20center / HTN-whitepaper-R8.pdf Such polyamides generally include one or more of the following structures:

[0054]

[0055] Non-limiting examples of polymers included in the polyamide include polyamide, polypropylene and copolymers, polyethylene and copolymers, polyesters, polystyrene, polyurethanes, and combinations thereof.

[0056] The nylon microfiber products described herein (including copolymers and terpolymers) may have a melting point between 223° C. and 390° C., such as between 223° C. and 380° C., or between 225° C. and 350° C. Additionally, the melting point may be greater than conventional nylon 6,6 melting point, depending on any additional polymeric materials added.

[0057] Other polymer materials that can be used in the compositions of the present disclosure include addition polymers and condensation polymer materials, such as polyolefins, polyacetals, polyamides (as previously discussed), polyesters, cellulose ethers and esters, polyalkylene sulfides, polyarylene oxides, polysulfones, modified polysulfone polymers, and mixtures thereof. Preferred materials in these broad categories include polyamides, polyethylene, polybutylene terephthalate (PBT), polypropylene, poly(vinyl chloride), polymethyl methacrylate (and other acrylic resins), polystyrene and its copolymers (including ABA type block copolymers), poly(vinylidene fluoride), poly(vinylidene chloride), polyvinyl alcohol of various degrees of hydrolysis (87% to 99.5%) in cross-linked and non-cross-linked forms. Addition polymers tend to be glassy (Tg greater than room temperature). This is the case for polyvinyl chloride and polymethyl methacrylate, polystyrene polymer compositions or alloys, or for low crystallinity in the case of polyvinylidene fluoride and polyvinyl alcohol materials. The nylon copolymers embodied herein can be made by combining various diamine compounds, various diacid compounds, and various cyclic lactam structures in a reaction mixture and then forming a nylon having monomer materials randomly positioned in a polyamide structure. For example, nylon 6,6-6,10 material is a nylon made from hexamethylene diamine and a blend of C6 and C10 diacids. Nylon 6-6,6-6,10 is a nylon made by copolymerization of epsilon aminocaproic acid, hexamethylene diamine, and a blend of C6 and C10 diacid materials.

[0058] In some respects, polyethylene can be used in the compositions of the present disclosure. The polyethylene that can be used for the method of this embodiment of the present disclosure preferably can have a melt index of about 5 grams / 10 minutes to about 200 grams / 10 minutes, for example, about 17 grams / 10 minutes to about 150 grams / 10 minutes. Polyethylene preferably should have a density of about 0.85 grams / ml to about 1.1 grams / ml, for example, about 0.93 grams / ml to about 0.95 grams / ml. Most preferably, the melt index of polyethylene is about 150 and the density is about 0.93.

[0059] The blend or copolymer of polyethylene and nylon can be formed in any suitable manner. Typically, the nylon compound is nylon 6,6; however, other polyamides of the nylon family can be used. Mixtures of nylons can also be used. In a specific example, polyethylene is blended with a mixture of nylon 6 and nylon 6,6. Polyethylene and nylon polymers are typically supplied in the form of pellets, chips, flakes, etc. The desired amount of polyethylene pellets or chips can be blended with nylon pellets or chips in a suitable mixing device (such as a drum roller, etc.), and the resulting blend can be introduced into the feed hopper of a conventional extruder or meltblown line.

[0060] In addition, different species of polymer major classes can be blended. For example, high molecular weight styrene materials can be blended with low molecular weight high impact polystyrene. Nylon-6 materials can be blended with nylon copolymers (such as nylon-6; 6,6; 6,10 copolymers). In addition, polyvinyl alcohols with low hydrolysis degrees (such as 87% hydrolyzed polyvinyl alcohol) can be blended with fully or superhydrolyzed polyvinyl alcohols with hydrolysis degrees of 98 to 99.9% and higher. All of these materials in admixture can be crosslinked using appropriate crosslinking mechanisms. Nylons can be crosslinked using crosslinking agents that react with nitrogen atoms in amide bonds. Polyvinyl alcohol materials can be crosslinked using hydroxyl reactive materials (such as monoaldehydes, such as formaldehyde, urea, melamine-formaldehyde resins and their analogs, boric acid and other inorganic compounds, dialdehydes, diacids, urethanes, epoxy resins and other known crosslinking agents). Cross-linking technology is a well-known and well-understood phenomenon in which cross-linking agents react and form covalent bonds between polymer chains to significantly improve molecular weight, chemical resistance, overall strength, and resistance to mechanical degradation.

[0061] One preferred mode is a polyamide comprising a first polymer and a second but different polymer (different in polymer type, molecular weight or physical properties) conditioned or treated at elevated temperatures. The polymer blend can be reacted and formed into a single chemical species or can be physically combined into a blended composition through an annealing process. Annealing means a physical change, such as crystallinity, stress relaxation or orientation. The preferred materials are chemically reacted into a single polymer species so that differential scanning calorimeter (DSC) analysis reveals a single polymeric material to produce improved stability when exposed to high temperature, high humidity and difficult operating conditions. Preferred materials for the blended polymer system include nylon 6; nylon 6,6; nylon 6,10; nylon (6-6,6-6,10) copolymers and other linear, generally aliphatic nylon compositions.

[0062] Suitable polyamides may include, for example, 20% nylon 6, 60% nylon 6,6, and 20% polyester by weight. The polyamide may include a combination of miscible polymers or a combination of immiscible polymers. In some aspects, the composition is free of aromatic polyamide.

[0063] In some aspects, the polyamide can include nylon 6. In terms of lower limits, the polyamide can include nylon 6 in an amount of at least 0.1 wt%, such as at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, or at least 20 wt%. In terms of upper limits, the polyamide can include nylon 6 in an amount of 99.9 wt% or less, 99 wt% or less, 95 wt% or less, 90 wt% or less, 85 wt% or less, or 80 wt% or less. In terms of ranges, the polyamide can include nylon 6 in an amount of 0.1 to 99.9 wt%, such as 1 to 99 wt%, 5 to 95 wt%, 10 to 90 wt%, 15 to 85 wt%, or 20 to 80 wt%.

[0064] In some aspects, the polyamide may include nylon 6,6. In terms of lower limits, the polyamide may include nylon 6,6 in an amount of at least 0.1 wt%, such as at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, or at least 20 wt%. In terms of upper limits, the polyamide may include nylon 6,6 in an amount of 99.9 wt% or less, 99 wt% or less, 95 wt% or less, 90 wt% or less, 85 wt% or less, or 80 wt% or less. In terms of ranges, the polyamide may include nylon 6,6 in an amount of 0.1 to 99.9 wt%, such as 1 to 99 wt%, 5 to 95 wt%, 10 to 90 wt%, 15 to 85 wt%, or 20 to 80 wt%.

[0065] In some aspects, the polyamide is predominantly nylon 6,6, such as at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or 100 wt% nylon 6,6.

[0066] In some aspects, the polyamide may include nylon 6I. In terms of lower limits, the polyamide may include nylon 6I in an amount of at least 0.1 wt%, such as at least 0.5 wt%, at least 1 wt%, at least 5 wt%, at least 7.5 wt%, or at least 10 wt%. In terms of upper limits, the polyamide may include nylon 6I in an amount of 50 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, or 20 wt% or less. In terms of ranges, the polyamide may include nylon 6I in an amount of 0.1 to 50 wt%, such as 0.5 to 40 wt%, 1 to 35 wt%, 5 to 30 wt%, 7.5 to 25 wt%, or 10 to 20 wt%.

[0067] In some aspects, the polyamide may include nylon 6T. In terms of lower limits, the polyamide may include nylon 6T in an amount of at least 0.1 wt%, such as at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, or at least 20 wt%. In terms of upper limits, the polyamide may include nylon 6T in an amount of 50 wt% or less, 47.5 wt% or less, 45 wt% or less, 42.5 wt% or less, 40 wt% or less, or 37.5 wt% or less. In terms of ranges, the polyamide may include nylon 6T in an amount of 0.1 to 50 wt%, such as 1 to 47.5 wt%, 5 to 45 wt%, 10 to 42.5 wt%, 15 to 40 wt%, or 20 to 37.5 wt%.

[0068] Block copolymers can also be used in the methods of the present disclosure. For such copolymers, the choice of solvent swelling agent is important. The solvent is selected so that both blocks are soluble in the solvent. An example is an ABA (styrene-EP-styrene) or AB (styrene-EP) polymer in dichloromethane solvent. If one component is not soluble in the solvent, it will form a gel. An example of such a block copolymer is Styrene-b-butadiene and styrene-b-hydrogenated butadiene (ethylene propylene), Type e-caprolactam-b-ethylene oxide, Polyester-b-ethylene oxide and polyurethanes of ethylene oxide and isocyanate.

[0069] Addition polymers such as polyvinylidene fluoride, syndiotactic polystyrene, copolymers of vinylidene fluoride and hexafluoropropylene, polyvinyl alcohol, polyvinyl acetate, amorphous addition polymers such as poly(acrylonitrile) and its copolymers with acrylic acid and methacrylates, polystyrene, poly(vinyl chloride) and its various copolymers, poly(methyl methacrylate) and its various copolymers are known to be relatively easy to solution spin because they are soluble at low pressures and temperatures. It is contemplated that these can be melt spun according to the present disclosure as a method of making fibers.

[0070] There are substantial advantages to forming polymer compositions comprising two or more polymeric materials in a polymer admixture, alloy format, or in a crosslinked chemically bonded structure. Without being bound by theory, it is believed that such polymer compositions improve physical properties by altering polymer attributes, such as improving polymer chain flexibility or chain mobility, overall molecular weight, and by forming a network of polymeric materials to provide reinforcement.

[0071] In one embodiment of this concept, two related polymer materials can be blended for beneficial properties. For example, a high molecular weight polyvinyl chloride can be blended with a low molecular weight polyvinyl chloride. Similarly, a high molecular weight nylon material can be blended with a low molecular weight nylon material.

[0072] The polyamide can have a relative viscosity (RV) of at least 20, e.g., at least 25, at least 30, or at least 35. In terms of upper limits, the polyamide can have an RV of less than 70, e.g., less than 60, less than 55, or less than 50. In terms of ranges, the polyamide can have an RV of 20 to 70, e.g., 25 to 60, 30 to 55, or 35 to 50.

[0073] The polyamide end groups can be controlled to achieve the desired properties. Nylon 6,6, for example, contains amino end groups and acid end groups. The acid end groups include inert acetic acid end groups and reactive carboxylic acid end groups. In some aspects, the amine end groups are present in an amount of less than 50 μeq / gram of polyamide, for example, less than 45 μeq / gram, less than 40 μeq / gram or less than 35 μeq / gram. In terms of lower limits, the amine end groups are present in an amount of at least 5 μeq / gram, for example, at least 10 μeq / gram, at least 15 μeq / gram or at least 20 μeq / gram. In terms of scope, the amine end groups can be present in an amount of 5 to 50 μeq / gram, for example, 10 to 45 μeq / gram, 15 to 40 μeq / gram or 20 to 35 μeq / gram.

[0074] As used herein, delta end groups (DEG or DEGs) are defined as the amount of amine end groups (-NH2) minus the amount of carboxylic acid end groups (-COOH). DEG calculation methods are well known.

[0075] As described above, the base polyamide composition utilizes specific ranges and / or limits of DEG levels. In some embodiments, the base polyamide composition has a DEG level of -30 μeq / gram to -90 μeq / gram, e.g., -35 μeq / gram to -85 μeq / gram, -40 μeq / gram to -80 μeq / gram, -45 μeq / gram to -75 μeq / gram, -50 μeq / gram to -70 μeq / gram, -55 μeq / gram to -65 μeq / gram, -60 μeq / gram to -65 μeq / gram, -45 μeq / gram to -65 μeq / gram, -45 μeq / gram to -60 μeq / gram, -50 μeq / gram to -65 μeq / gram, or -55 to -60 μeq / gram. In terms of lower limits, the base polyamide composition may have a DEG level of greater than -90 μeq / gram, greater than -85 μeq / gram, greater than -80 μeq / gram, greater than -75 μeq / gram, greater than -70 μeq / gram, greater than -65 μeq / gram, greater than -60 μeq / gram, greater than -55 μeq / gram, or greater than -50 μeq / gram. In terms of upper limits, the base polyamide composition may have a DEG level of less than -30 μeq / gram, such as less than -35 μeq / gram, less than -40 μeq / gram, less than -45 μeq / gram, less than -50 μeq / gram, less than -55 μeq / gram, or less than -60 μeq / gram. It has also been found that these specific DEG levels provide an unexpected combination of favorable synergistic properties in the final product after compounding as described herein.

[0076] In some cases, the DEG level can be obtained / realized / controlled by the amount of excessive hexamethylenediamine (HMD) in the control polymerization mixture. It is believed that HMD is more volatile than the (di) carboxylic acid (e.g., adipic acid) used for the reaction. HMD and carboxylic acid are used for balancing the formula (theoretical value based on the end group), and the balance between the two (and therefore DEG) can be adjusted to achieve the desired properties in the polyamide composition. In some cases, excessive HMD is not added to the polymerization mixture. In some cases, adipic acid is added to the polymerization mixture.

[0077] In some cases, the DEG level may be obtained / achieved / controlled by incorporation of (mono)acids and / or (mono)amines, for example by "capping" some of the terminal structures to achieve a desired DEG level, for example a desired end group balance.

[0078] In some cases, it has been found that the use of monofunctional endcaps provides surprising benefits in controlling (e.g., slowing) the polymerization rate. Without being bound by theory, it is believed that endcaps (1) limit the amount of reactive end groups; and (2) limit the degree of polymerization to a finite number. In some cases, the more endcaps are used, the lower the (maximum) molecular weight will be (at 100% conversion). Both the former and the latter can be achieved by establishing a high negative DEG system. Monofunctional acid and / or amine addition will increase the negative DEG level.

[0079] In one embodiment, the (mono)acid and / or (mono)amine is incorporated at a level of 1 to 40 μeq / gram, for example, 1 μeq / gram to 35 μeq / gram, 3 μeq / gram to 35 μeq / gram, 3 μeq / gram to 30 μeq / gram, 5 μeq / gram to 30 μeq / gram, 5 μeq / gram to 25 μeq / gram, 7 μeq / gram to 25 μeq / gram, 7 μeq / gram to 20 μeq / gram, 10 μeq / gram to 20 μeq / gram, or 10 μeq / gram to 15 μeq / gram. In terms of upper limits, the (mono)acid and / or (mono)amine may be incorporated at a level of less than 40 μeq / gram, for example, less than 35 μeq / gram, less than 30 μeq / gram, less than 25 μeq / gram, less than 20 μeq / gram, or less than 15 μeq / gram. In terms of lower limits, the (mono)acid and / or (mono)amine may be incorporated at a level greater than 1 μeq / gram, for example greater than 3 μeq / gram, greater than 5 μeq / gram, greater than 7 μeq / gram, or greater than 10 μeq / gram.

[0080] Exemplary (mono) acids include, but are not limited to, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, octanoic acid, palmitic acid, myristic acid, decanoic acid, undecanoic acid, dodecanoic acid, oleic acid or stearic acid or any combination thereof. Exemplary (mono) amines include, but are not limited to, benzylamine, ethylamine, propylamine, butylamine, amylamine, hexylamine, 2-ethyl-1-hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, amylamine, tert-butylamine, tetradecylamine, hexadecylamine or octadecylamine or any combination thereof.

[0081] Surprisingly and unexpectedly, it has been found that by controlling the carboxylic acid end group / amine end group ratio in the polyamide resin, the increase in weight average molecular weight, number average molecular weight, z-average molecular weight, polydispersity index, and intrinsic viscosity of the polyamide resin during compounding is minimized. In some aspects, the carboxylic acid end group / amine end group ratio in the polyamide resin is greater than 1.8, e.g., greater than 1.9, greater than 2, greater than 2.1, greater than 2.2, greater than 2.3, greater than 2.4, greater than 2.5, greater than 2.6, or greater than 2.7. In terms of upper limits, the carboxylic acid end group / amine end group ratio in the polyamide resin is 3:1 or less, for example, 2.975:1 or less, 2.95:1 or less, 2.925:1 or less, 2.9:1 or less, 2.875:1 or less, 2.85:1 or less, 2.825:1 or less, 2.8:1 or less, 2.775:1 or less, 2.75:1, 2.725:1 or less, or 2.7:1 or less. In terms of ranges, the carboxylic acid end group / amine end group ratio in the polyamide resin can be from 1.81:1 to 3:1, e.g., from 1.9:1 to 3:1, 2:1 to 3:1, 2.1:1 to 2.975:1, 2:1 to 2.95:1, 2.2:1 to 2.925:1, 2.3:1 to 2.9:1, or 2.4:1 to 2.7:1, including all ranges and values ​​therebetween.

[0082] The amount of amino end groups and / or acid is determined potentiometrically after the polyamide has been dissolved. One method is described, for example, in "Encyclopedia of Industrial Chemical Analysis", Vol. 17, p. 293, 1973. The amount of amine end groups (GTA) and / or acid (BMS) can be determined potentiometrically after the polyamide has been completely dissolved in trifluoroethanol and an excess of a strong base has been added. The basic species is then titrated with an aqueous solution of a strong acid. The amount of chain limiter is calculated by the ratio between the molar amount of chain limiter added and the mass of the product polymer. The amount of chain limiter can also be determined by hydrolyzing the polyamide followed by analysis by liquid chromatography.

[0083] Obtaining polyamide 6,6 unbalanced amines can be achieved in various ways known to those skilled in the art, such as during polymerization according to the stoichiometric imbalance of diamine compounds and diacids, or by adding compounds during extrusion to obtain polyamide 6,6 unbalanced final amines.

[0084] In terms of lower limits, the composition can include at least 40 wt %, for example at least 42.5 wt %, at least 45 wt %, at least 47.5 wt %, at least 50 wt % or at least 55 wt % of the polyamide. In terms of upper limits, the composition can include 70 wt % or less, 68 wt % or less, 66 wt % or less, 64 wt % or less, 62 wt % or less or 60 wt % or less of the polyamide. In terms of scope, the composition can include 40 to 70 wt %, for example 42.5 to 68 wt %, 45 to 66 wt %, 47.5 to 64 wt %, 50 to 62 wt % or 55 to 60 wt % of the polyamide.

[0085] Synergist

[0086] The synergists used in the compositions described herein can vary widely. In some aspects, the synergist can be a phosphorus-containing compound. In some aspects, the synergist is a phosphate, such as a polyphosphate. Exemplary synergists include phosphinates, aluminum diethylphosphinate, and melamine polyphosphate. Further examples include condensation products of melamine and / or reaction products of melamine with polyphosphoric acid and / or reaction products of condensation products of melamine with polyphosphoric acid, or mixtures thereof; or containing melem, melam, melon, dimelamine pyrophosphate, melamine polyphosphate, melem polyphosphate, melam polyphosphate, melon polyphosphate, and / or mixed polysalts thereof; or containing the formula (NH4) y H 3-y PO4 and / or (NH4PO3) z A nitrogen-containing phosphate wherein y is 1 to 3 and z is 1 to 10000. Still further examples include mixed alkali metal-aluminum phosphites and mixtures thereof with alkali metal salts.

[0087] In some aspects, the builder can be a phosphorus-free builder. An exemplary additional builder includes Dow Silicone powder sold as 43-821. Additional synergists include zinc borate, calcium hypophosphite, aluminum hydrogen phosphite combined with aluminum salts.

[0088] In terms of the lower limit, said composition can comprise at least 0.1 % by weight, for example at least 0.5 % by weight, at least 1 % by weight, at least 2 % by weight, at least 3 % by weight or at least 4 % by weight of the synergist. In terms of the upper limit, said composition can comprise 15 % by weight or less, 14 % by weight or less, 13 % by weight or less, 12 % by weight or less, 11 % by weight or less or 10 % by weight or less of the synergist. In terms of scope, said composition can comprise 0.1 to 15 % by weight, for example 0.5 to 14 % by weight, 1 to 13 % by weight, 2 to 12 % by weight, 3 to 11 % by weight or 4 to 10 % by weight of the synergist of the amount.

[0089] additive

[0090] In some aspects, the composition may also include various additives, such as fillers, reinforcing agents, stabilizers, colorants, etc., provided that the additives do not adversely affect the desired properties of the thermoplastic composition. Mixtures of additives may be used. These additives may be mixed at a suitable time during the mixing process of the components used to form the polymer composition.

[0091] The example of other suitable additive comprises flow modifier, heat stabilizer, filler and combination thereof.Generally speaking, additive can exist with at least 0.05 % by weight, for example at least 0.1 % by weight, at least 0.5 % by weight, at least 1 % by weight, at least 5 % by weight or at least 10 % by weight.With regard to the upper limit, additive can exist with 55 % by weight or less, 52.5 % by weight or less, 50 % by weight or less, 47.5 % by weight or less or 45 % by weight or less.With regard to scope, additive can exist with 0.05 to 55 % by weight, for example 0.5 to 52.5 % by weight, 1 to 50 % by weight, 5 to 47.5 % by weight or 10 to 45 % by weight.

[0092] In some respects, said composition can include glass fiber.Glass fiber can exist in an amount of at least 5 wt %, for example, at least 10 wt %, at least 12.5 wt %, at least 15 wt %, at least 20 wt % or at least 25 wt %.With regard to the upper limit, glass fiber can exist in an amount of 45 wt % or less, 42.5 wt % or less, 40 wt % or less, 37.5 wt % or less or 35 wt % or less.With regard to the scope, glass fiber can exist in an amount of 5 to 45 wt %, for example, 10 to 42.5 wt %, 12.5 to 40 wt %, 15 to 37.5 wt %, 20 to 35 wt % or 25 to 35 wt %.

[0093] In some aspects, one or more heat stabilizers may be included in the composition. Suitable heat stabilizer additives include, for example, organic phosphites, such as triphenyl phosphite, tris-(2,6-dimethylphenyl) phosphite, tris-(mixed mono- and di-nonylphenyl) phosphite, etc.; triphenylphosphine, phosphonates, such as dimethylphenylphosphonate, etc., phosphates, such as trimethyl phosphate, etc., or a combination comprising at least one of the above heat stabilizers. In some aspects, the heat stabilizer is a copper-containing heat stabilizer and an organophosphorus compound comprising a copper halide. The organophosphorus compound may be triphenylphosphine or triphenyl phosphite. The organophosphorus compound and the copper halide may form a complex, such as copper halide (I) / bis (triphenylphosphine), copper halide (I) / bis (triphenyl phosphite), copper iodide (I) / bis (triphenylphosphite), and / or copper iodide (I) / bis (triphenyl phosphite). In some aspects, the thermal stabilizer may include bromine so that the loading in the final compound contains less than 900 ppm bromine to produce a "halogen-free grade." In some aspects, the thermal stabilizer may include copper complexed or otherwise in a form that reduces water solubility and / or prevents copper migration, such as non-migrating copper, to mitigate contact corrosion of copper from the final product.

[0094] The heat stabilizer can be present in an amount of at least 0.05 wt %, such as at least 0.1 wt %, at least 0.25 wt %, at least 0.5 wt %, at least 0.75 wt %, at least 1 wt % or at least 1.5 wt %. In terms of upper limits, the heat stabilizer can be present in an amount of 5 wt % or less, 4.5 wt % or less, 4.25 wt % or less, 4 wt % or less, 3.75 wt % or less, or 3.5 wt % or less. In terms of ranges, the heat stabilizer can be present in an amount of 0.05 to 5 wt %, such as 0.1 to 4.75 wt %, 0.25 to 4.5 wt %, 0.5 to 4.25 wt %, 0.75 to 4 wt %, 1 wt % to 3.75 wt %, or 1.5 to 3.5 wt %.

[0095] In some aspects, the heat stabilizer may include CuI, KI heat stabilizer and / or Br, Cu, P heat stabilizer. In these aspects, CuI, KI heat stabilizer can be present in an amount of at least 0.1 wt%, such as at least 0.25 wt%, at least 0.5 wt%, at least 0.75 wt%, at least 1 wt% or at least 1.5 wt%. In terms of upper limit, CuI, KI heat stabilizer can be present in an amount of 4 wt% or less, 3.75 wt% or less, 3.5 wt% or less, or 3 wt% or less. In terms of range, CuI, KI heat stabilizer can be present in an amount of 0.1 to 4 wt%, such as 0.25 to 3.75 wt%, 0.5 to 3.5 wt%, 0.75 to 3.25 wt%, 1 wt% to 3 wt%, or 1.5 to 3 wt%. In these aspects, the Br, Cu, P thermal stabilizer can be present in an amount of at least 0.01 wt%, such as at least 0.05 wt%, at least 0.075 wt%, or at least 0.1 wt%. In terms of upper limits, the Br, Cu, P thermal stabilizer can be present in an amount of 1.5 wt% or less, 1 wt% or less, 0.75 wt% or less, or 0.5 wt% or less. In terms of ranges, the Br, Cu, P thermal stabilizer can be present in an amount of 0.01 to 1.5 wt%, such as 0.05 to 1 wt%, 0.1 to 0.75 wt%, or 0.1 to 0.5 wt%.

[0096] Additional fillers or reinforcing agents include any materials known for these uses. For example, suitable fillers and reinforcing agents include silicate and silica powders, such as aluminum silicate (mullite), synthetic calcium silicate, zirconium silicate, fused silica, crystalline silica graphite, natural silica sand, etc.; boron powders, such as boron nitride powder, boron silicate powder, etc.; oxides, such as titanium dioxide, aluminum oxide, magnesium oxide, etc.; calcium sulfate (as its anhydrate, dihydrate or trihydrate); single crystal fibers or "whiskers", such as silicon carbide, aluminum oxide, boron carbide, iron, nickel, copper, etc.; fibers (including continuous fibers and chopped fibers), such as carbon fibers, glass fibers such as E glass, etc.; sulfides, such as molybdenum sulfide, zinc sulfide, etc.; barium compounds, such as barium titanate, barium ferrite, barium sulfate, barite, etc.; metals and metal oxides, such as particulate or fibrous aluminum, bronze, zinc, copper and nickel, etc.; plate-like fillers, such as glass flakes, plate-like silicon carbide, aluminum diboride, aluminum flakes , steel flakes, etc.; fibrous fillers, such as short inorganic fibers, such as those derived from a blend comprising at least one of aluminum silicate, aluminum oxide, magnesium oxide, and calcium sulfate hemihydrate, etc.; natural fillers and reinforcing materials, such as wood flour obtained by pulverizing wood, fibrous products such as cellulose, cotton, sisal, jute, starch, cork flour, lignin, peanut shells, corn, rice husks, etc.; reinforcing organic fibrous fillers formed by organic polymers capable of forming fibers such as poly(ether ketone), polyimide, polybenzoxazole, poly(phenylene sulfide), aromatic polyamide, aromatic polyimide, polyetherimide, etc.; and additional fillers and reinforcing agents, such as mica, feldspar, soot, magnesium aluminosilicate salt (fillite), quartz, quartzite, pearlite, diatomite (tripoli), diatomaceous earth, carbon black, etc., or a combination comprising at least one of the above fillers or reinforcing agents. In some aspects, the composition does not contain aromatic polyamide.

[0097] Filler and reinforcing agent can be coated with metal material layer to promote conductivity, or with silane surface treatment to improve bonding and dispersion with polymer matrix resin. In addition, reinforcing filler can be provided in the form of monofilament or multifilament fiber, and can be used alone or in combination with other types of fibers, by for example co-braiding or core / skin type, side-by-side type or matrix-fibril type structure, or by other methods known to the technicians in the field of fiber manufacturing. Suitable co-braiding structure includes for example glass fiber-carbon fiber, carbon fiber-aromatic polyimide (aramid) fiber and aromatic polyimide fiber-glass fiber, etc. Fiber filler can be for example with roving, woven fiber reinforcement material, such as 0-90 degree fabric, etc.; non-woven fiber reinforcement material, such as continuous strand mat, chopped strand mat, tulle, paper and felt, etc.; or three-dimensional reinforcement material, such as braided form supply. In some aspects, the composition does not contain layered silicate. In addition, in some aspects, the composition does not contain ammonium polyphosphate and zinc polyphosphate. In other aspects, the composition is free of melamine cyanurate and zinc borate.

[0098] Antioxidants or "stabilizers" (e.g., hindered phenols and / or secondary aromatic amines) and, optionally, secondary antioxidants (e.g., phosphates and / or thioesters) may also be included as additives. Suitable stabilizer additives include, for example, metal phosphites, such as sodium, calcium or aluminum phosphites, or sodium, calcium or aluminum hypophosphites, and the like. Other suitable antioxidants include organic phosphites, such as tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, etc.; alkylated monophenols or polyphenols; alkylation reaction products of polyphenols with dienes, such as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane, etc.; butylation reaction products of p-cresol or dicyclopentadiene; alkylated hydroquinones; hydroxylated thiodiphenyl ethers; alkylidene-bisphenols; benzyl compounds; β-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane; Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid and monohydric alcohols or polyhydric alcohols; Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid and monohydric alcohols or polyhydric alcohols; Esters of sulfanyl or thioaryl compounds, such as distearyl thiopropionate, dilauryl thiopropionate, ditridecyl thiodipropionate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, etc.; amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid, etc., or a combination comprising at least one of the above antioxidants.

[0099] Light stabilizers and / or ultraviolet (UV) absorbing additives may also be used. Suitable light stabilizer additives include, for example, benzotriazoles such as 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-benzotriazole, and 2-hydroxy-4-n-octyloxybenzophenone, or a combination comprising at least one of the foregoing light stabilizers.

[0100] Suitable UV absorbing additives include, for example, hydroxybenzophenones; hydroxybenzotriazoles; hydroxybenzotriazines; cyanoacrylates; N,N'-oxanilides; benzoxazinones; 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-phenol (CYASORB TM 5411); 2-Hydroxy-4-n-octyloxybenzophenone (CYASORB TM 531); 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)-phenol (CYASORB TM 1164); 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one)(CYASORBTM UV-3638); 1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane (UVINUL TM 3030); 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one); 1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane; nanoscale inorganic materials, such as titanium oxide, cerium oxide and zinc oxide, all having a particle size of less than about 100 nanometers; and the like, or a combination comprising at least one of the foregoing ultraviolet absorbers, based on 100 parts by weight of the polymer component of the polymer composition.

[0101] In some aspects, fillers include zinc borate and zinc stearate. When included, fillers can be present in an amount of at least 0.01 wt %, such as at least 0.05 wt %, at least 0.075 wt %, or at least 0.1 wt %. With regard to upper limits, fillers can be present in an amount of 5 wt % or less, 4.75 wt % or less, 4.5 wt % or less, or 4.25 wt % or less. With regard to scope, fillers can be present in an amount of 0.01 to 5 wt %, such as 0.05 to 4.75 wt %, 0.1 to 4.5 wt %, or 0.1 to 4.5 wt %.

[0102] Plasticizers, lubricants and / or mold release additives may also be used. There is a large overlap between these types of materials, including, for example, phthalates such as dioctyl-4,5-epoxy-hexahydrophthalate; tris-(octyloxycarbonylethyl) isocyanurate; tristearin; poly-α-olefins; epoxidized soybean oil; silicones, including silicone oils; esters such as fatty acid esters such as alkyl stearates, such as methyl stearate; stearyl stearate, pentaerythritol tetrastearate, and the like; mixtures of methyl stearate and hydrophilic and hydrophobic nonionic surfactants (including polyethylene glycol polymers, polypropylene glycol polymers and copolymers thereof), such as methyl stearate and polyethylene-polypropylene glycol copolymers in a suitable solvent; waxes such as beeswax, montan wax, paraffin wax, and the like.

[0103] Colorants such as pigments and / or dye additives may also be present. Suitable pigments include, for example, inorganic pigments such as metal oxides and mixed metal oxides, such as zinc oxide, titanium dioxide, iron oxides, etc.; sulfides, such as zinc sulfide, etc.; aluminates; sodium sulfo-silicates; sulfates), chromates, etc.; carbon black; zinc ferrite; ultramarine blue; Pigment Brown 24; Pigment Red 101; Pigment Yellow 119; organic pigments such as azos, diazos, quinacridones, perylenes, naphthalenetetracarboxylic acids, flavanthrones, isoindolinones, tetrachloroisoindolones, anthraquinones, tribenzo[cd,jk]pyrene-5,10-diones, dioxazines, phthalocyanines and azo lakes; Pigment Blue 60, Pigment Red 122, Pigment Red 149, Pigment Red 177, Pigment Red 179, Pigment Red 202, Pigment Violet 29, Pigment Blue 15, Pigment Green 7, Pigment Yellow 147 and Pigment Yellow 150, or a combination comprising at least one of the foregoing pigments.

[0104] These additional additives, when present, can be present in an amount of at least 0.01 wt %, such as at least 0.05 wt %, at least 0.075 wt %, or at least 0.1 wt %. In terms of upper limits, the additional additives can be present in an amount of 4 wt % or less, 3 wt % or less, 2.75 wt % or less, or 2.5 wt % or less. In terms of ranges, the additional additives can be present in an amount of 0.01 to 4 wt %, such as 0.05 to 3 wt %, 0.1 to 2.75 wt %, or 0.1 to 2.5 wt %.

[0105] Method of forming the final molded product

[0106] As described herein, the composition can be compounded and then extruded or injection molded to form the final product. In some aspects, by using a polyamide resin having a carboxylic acid / amine end group ratio greater than 1.8, pressure spikes during extrusion are avoided. Additional benefits during extrusion are described herein, including controlled molecular weight enhancement.

[0107] use

[0108] Due to their thermal stability, flowability, processability and recyclability, the compositions of the present invention can be used in a variety of applications. The products can be used in electrical and electrical applications, including connectors, relays, junction boxes, motors, wall panels, lamps, circuit breakers, switches and sensors, among other applications.

[0109] The unique features of the compositions of the present disclosure provide functionality and benefits not seen in traditional products, such as existing flame retardant resins and products formed therefrom.

[0110] Implementation

[0111] Embodiment 1: A flame retardant polyamide composition comprising a polyamide, a non-halogenated flame retardant, and a synergist, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8.

[0112] Embodiment 2: The embodiment of embodiment 1, wherein the composition further comprises one or more additives.

[0113] Embodiment 3: The embodiment of embodiment 1 or 2, wherein the one or more additives comprise a flow improver, a thermal stabilizer, a filler, or a combination thereof.

[0114] Embodiment 4: The embodiment of any one of embodiments 1 to 3, wherein the weight average molecular weight of the composition is 20,000 to 100,000 Daltons, 25,000 to 65,000 Daltons, or 30,000 to 50,000 Daltons.

[0115] Embodiment 5: The embodiment of any one of embodiments 1 to 4, wherein the z-average molecular weight is 30,000 to 600,000, 35,000 to 220,000 Daltons, 40,000 to 120,000 Daltons, or 45,000 to 90,000 Daltons.

[0116] Embodiment 6: The embodiment of any one of embodiments 1 to 5, wherein the composition comprises 35 to 70 weight percent polyamide, based on the total weight of the composition.

[0117] Embodiment 7: The embodiment of any one of embodiments 1 to 6, wherein the composition comprises 5 to 25 weight percent of a non-halogenated flame retardant based on the total weight of the composition.

[0118] Embodiment 8: The embodiment of any one of embodiments 1 to 7, wherein the composition comprises 0.1 to 15 wt % synergist based on the total weight of the composition.

[0119] Embodiment 9: The embodiment of any one of embodiments 1 to 8, wherein the composition further comprises 5 to 45 wt% glass fibers based on the total weight of the composition.

[0120] Embodiment 10: The embodiment of any one of embodiments 1 to 9, wherein the composition comprises 0.05 to 5 weight percent thermal stabilizer based on the total weight of the composition.

[0121] Embodiment 11: The embodiment of any one of embodiments 1 to 10, wherein the non-halogenated flame retardant comprises an organophosphorus flame retardant.

[0122] Embodiment 12: The embodiment of any one of embodiments 1 to 11, wherein the builder comprises a polyphosphate.

[0123] Embodiment 13: The embodiment of any one of embodiments 1 to 12, wherein the synergist comprises melamine polyphosphate.

[0124] Embodiment 14: The embodiment of any one of embodiments 1 to 13, wherein the polyamide comprises less than 50 μeq / gram of amine end groups.

[0125] Embodiment 15: The embodiment of any one of Embodiments 1 to 14, wherein the polyamide comprises nylon 6,6.

[0126] Embodiment 16: A molded flame retardant polyamide product formed from the composition of any one of Embodiments 1 to 15.

[0127] Embodiment 17: A method of forming a molded product, comprising: a) forming a polyamide having a carboxylic acid / amine end group ratio greater than 1.8; b) compounding the polyamide with a non-halogenated flame retardant and a synergist comprising a phosphorus-containing compound to form a compounded composition; and c) molding the compounded composition to form a molded product.

[0128] Embodiment 18: The embodiment of embodiment 17, wherein the composition further comprises one or more additives.

[0129] Embodiment 19: The embodiment of embodiment 17 or 18, wherein the one or more additives comprise a flow improver, a thermal stabilizer, a filler, or a combination thereof.

[0130] Embodiment 20: The embodiment of any one of embodiments 17 to 19, wherein the weight average molecular weight of the product is 20,000 to 100,000.

[0131] Embodiment 21: The embodiment of any one of embodiments 17 to 20, wherein the product has a z-average molecular weight of 50,000 to 600,000.

[0132] Embodiment 22: The embodiment of any one of Embodiments 17 to 21, wherein the product comprises 40 to 70 weight percent nylon 6,6 based on the total weight of the product.

[0133] Embodiment 23: The embodiment of any one of embodiments 17 to 22, wherein the product comprises 5 to 25 weight percent non-halogenated flame retardant based on the total weight of the product.

[0134] Embodiment 24: The embodiment of any one of embodiments 17 to 23, wherein the product comprises 0.1 to 15 wt% synergist based on the total weight of the product.

[0135] Embodiment 25: The embodiment of any one of Embodiments 17 to 24, wherein the product further comprises 5 to 45 wt% glass fibers based on the total weight of the product.

[0136] Embodiment 26: The embodiment of any one of embodiments 17 to 25, wherein the composition comprises 0.05 to 5 weight percent thermal stabilizer based on the total weight of the composition.

[0137] Embodiment 27: The embodiment of any one of Embodiments 17 to 26, wherein the non-halogenated flame retardant comprises an organophosphorus flame retardant.

[0138] Embodiment 28: The embodiment of any one of embodiments 17 to 27, wherein the builder comprises a polyphosphate.

[0139] Embodiment 29: The embodiment of any one of embodiments 17 to 28, wherein the synergist comprises melamine polyphosphate.

[0140] Embodiment 30: The embodiment of any one of Embodiments 17 to 29, wherein the polyamide comprises nylon 6,6.

[0141] Embodiment 31: A flame retardant polyamide composition comprising: 40 to 70 weight percent of a polyamide, 5 to 25 weight percent of a non-halogenated flame retardant; 0.1 to 15 weight percent of a synergist; 5 to 45 weight percent of glass fiber; and 0.05 to 5 weight percent of a thermal stabilizer, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8:1.

[0142] Embodiment 32: A flame retardant polyamide composition comprising: 40 to 70 weight percent of a polyamide, 5 to 25 weight percent of a non-halogenated flame retardant; 0.1 to 15 weight percent of a synergist; and 0.05 to 5 weight percent of a thermal stabilizer, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8:1.

[0143] Embodiment 33: A method of controlling the RV of a polyamide, the method comprising: determining a desired RV of the polyamide; and adjusting the value of at least one of an amine end group, an inert end group, or a carboxylic acid end group; wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8:1.

[0144] Embodiment 34: An embodiment according to embodiment 33, wherein the desired RV is at least 20 or at least 35.

[0145] Embodiment 35: An embodiment according to any one of embodiments 33-34, wherein the polyamide is nylon 6,6.

[0146] Embodiment 36: An embodiment according to any one of embodiments 1-35, wherein no flow modifier is used.

[0147] Embodiment 37: A flame retardant polyamide composition comprising a polyamide, a non-halogenated flame retardant, and a synergist, wherein the composition satisfies at least one of the following conditions: (a) the weight average molecular weight of the final composition is less than 300% higher than the weight average molecular weight of the starting polyamide resin; (b) the number average molecular weight of the final composition is less than 100% higher than the number average molecular weight of the starting polyamide resin; (c) the Z average molecular weight of the final composition is less than 100% higher than the Z average molecular weight of the starting polyamide resin; (d) the polydispersity index of the final composition is less than 300% higher than the weight average molecular weight of the starting polyamide resin; or (e) the intrinsic viscosity of the final composition is less than 100% higher than the intrinsic viscosity of the starting polyamide resin.

[0148] The present invention also relates to the following items:

[0149] 1. A flame retardant polyamide composition comprising a polyamide, a non-halogenated flame retardant and a synergist, wherein the polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8.

[0150] 2. The composition according to item 1, wherein the composition further comprises one or more additives.

[0151] 3. The composition according to item 2, wherein the one or more additives comprise a flow improver, a thermal stabilizer, a filler or a combination thereof.

[0152] 4. The composition according to any one of items 1 to 3, wherein the weight average molecular weight of the composition is from 20,000 to 100,000 Daltons.

[0153] 5. The composition according to any one of items 1 to 4, wherein the z-average molecular weight is from 30,000 to 600,000 Daltons.

[0154] 6. The composition according to any one of items 1 to 5, wherein the composition comprises 35 to 70 wt% polyamide, based on the total weight of the composition.

[0155] 7. The composition according to any one of items 1 to 6, wherein the composition comprises 5 to 25 wt% of non-halogenated flame retardant, based on the total weight of the composition.

[0156] 8. The composition according to any one of items 1 to 7, wherein the composition comprises 0.1 to 15 wt. % synergist, based on the total weight of the composition.

[0157] 9. The composition according to any one of items 1 to 8, wherein the composition further comprises 5 to 45 wt% glass fibers, based on the total weight of the composition.

[0158] 10. The composition according to any one of items 1 to 9, wherein the composition comprises 0.05 to 5 wt% of a heat stabilizer, based on the total weight of the composition.

[0159] 11. A method of forming a molded product, comprising:

[0160] a) forming a polyamide having a carboxylic acid / amine end group ratio greater than 1.8;

[0161] b) compounding the polyamide with a non-halogenated flame retardant and optionally a synergist, wherein the synergist comprises a phosphorus-containing compound to form a compounded composition; and

[0162] c) molding the compounded composition to form a molded product.

[0163] 12. The method according to item 11, wherein the composition further comprises one or more additives.

[0164] 13. The process according to any one of items 11-12, wherein the one or more additives comprise a flow improver, a thermal stabilizer, a filler or a combination thereof.

[0165] 14. The process according to any one of items 11 to 13, wherein the weight average molecular weight of the product is from 20,000 to 100,000.

[0166] 15. The process according to any one of items 11 to 14, wherein the product has a z-average molecular weight of 40,000 to 600,000.

[0167] 16. A method of controlling the RV of a polyamide, the method comprising:

[0168] a) determining the desired RV of the polyamide; and

[0169] b) adjusting the value of at least one of the amine end group, the inert end group or the carboxylic acid end group; and further excluding polymerization catalysts, sodium hypophosphite,

[0170] The polyamide has a carboxylic acid end group / amine end group ratio greater than 1.8.

[0171] 17. The method according to item 16, wherein the desired RV is at least 20.

[0172] 18. The process according to any one of items 16-17, wherein the polyamide is nylon 6,6.

[0173] 19. Process according to any of items 16 to 18, wherein the moulded product is free of flow modifiers.

[0174] 20. A flame retardant polyamide composition comprising polyamide, a non-halogenated flame retardant and a synergist, wherein the composition satisfies at least one of the following conditions:

[0175] (a) the weight average molecular weight of the final composition is less than 300% higher than the weight average molecular weight of the starting polyamide resin;

[0176] (b) the number average molecular weight of the final composition is less than 100% higher than the number average molecular weight of the starting polyamide resin;

[0177] (c) the Z-average molecular weight of the final composition is less than 100% higher than the Z-average molecular weight of the starting polyamide resin;

[0178] (d) the polydispersity index of the final composition is less than 300% higher than the weight average molecular weight of the starting polyamide resin; or

[0179] (e) The intrinsic viscosity of the final composition is less than 100% higher than the intrinsic viscosity of the starting polyamide resin.

[0180] The present disclosure is further understood by means of the following non-limiting examples.

[0181] Example

[0182] Example 1

[0183] Four samples of nylon 6,6 resin were prepared having the viscosities and end groups shown below.

[0184]

[0185] Each of the above resins is then combined with a flame retardant and synergist as described herein. The initial Mw, Mz, PDI and IV of the resin are measured, and then the final Mw, Mz, PDI and IV of the total composition after compounding are measured. It is found that resins A and B with a carboxylic acid / amine end group ratio greater than 1.8 have acceptable increases in Mw, Mz, PDI and IV during compounding. It is found that resins C and D with a carboxylic acid / amine end group ratio of 1.8 or less have unacceptable increases in Mw, Mz, PDI and / or IV during compounding. In addition, during compounding, resin D experiences undesirable pressure spikes in the extruder. The screw speed can be reduced or the screw design can be changed to reduce pressure growth, but lower productivity is less economical, and a milder screw design may not provide sufficient mixing of the additive components.

[0186] Example 2

[0187] Five sample compositions were prepared with the following components. The amounts of polyamide, flame retardant, flow modifier, and synergist were varied as shown. The polyamide in samples 1-2 was nylon 6,6 resin D. The polyamide in samples 3-5 was nylon 6,6 resin B. The flow modifier / synergist was Dow Silicone powder sold as 43-821. Flame retardant is Clariant as OP-1230 or OP-1400 is a phosphorus flame retardant sold as a flame retardant. For samples 1-3, the vacuum applied to the extruder was between -27 and -28 mmHg, and for samples 4-5, the vacuum applied to the extruder was -22 mmHg. Examples 1 and 2 used polyamide resin D and were found to have unacceptable increases in Mw, Mz, PDI, and IV. Examples 3 and 5 show that increasing the amount of vacuum applied to the extruder can cause the system to become too dry, which can enhance molecular weight growth; therefore, it is best to apply vacuum to a moderate level to minimize molecular weight growth during compounding. Example 4 shows that for OP-1400, with Compared with OP-1230, the molecular weight growth during compounding is slightly smaller.

[0188]

[0189]

[0190] Example 3

[0191] Ten sample compositions were prepared with the following components. The amounts of polyamide, flame retardant, and synergist were varied as shown. The polyamide in samples 6-8 and 11-15 was nylon 6,6 resin B. The polyamide in sample 9 was nylon 6,6 resin A. The polyamide in sample 10 was nylon 6,6 resin C. The synergist in samples 6-7, 9-13, and 15 was melamine polyphosphate sold by JLS. The synergist in sample 14 was high thermal stability melamine polyphosphate. Samples 11-12 included The flow modifier was sold as TP-P1507. The flame retardant in each sample was Clariant as OP-1230 or OP-1400 is a phosphorus flame retardant for sale.

[0192]

[0193]

[0194] Example 4

[0195] Six sample compositions were prepared with the following components. The amounts of polyamide, flame retardant, and synergist were varied as indicated. The polyamide in Examples 16-21 was nylon 6,6 resin B. The synergist in Examples 16-19 was melamine polyphosphate sold by JLS. Examples 16-18 and 20-21 included a heat stabilizer sold by Brueggemann as TP-H1606. Example 19 included a heat stabilizer sold by Brueggemann as H3386. The flame retardant in each sample was Clariant as OP-1230 or OP-1400 is a phosphorus flame retardant for sale.

[0196]

[0197]

[0198] Although the present disclosure has been described in detail, it is easy for those skilled in the art to see modifications within the spirit and scope of the present disclosure. Such modifications are also considered to be a part of the present disclosure. Based on the above discussion, the relevant knowledge in the art and the references discussed in connection with the "background" above (their disclosures are all incorporated herein by reference), further description is considered unnecessary. In addition, it should be understood from the above discussion that aspects of the present disclosure and a part of various embodiments can be combined or interchanged in whole or in part. In addition, those of ordinary skill in the art will recognize that the above description is only illustrative and is not intended to limit the present disclosure. Finally, all patents, disclosures and applications mentioned herein are incorporated herein by reference in their entirety.

Claims

1. A flame retardant polyamide composition, consisting of: Polyamide, Non-halogenated flame retardants, Synergists, Fiberglass, and one or more additives including flow improvers, thermal stabilizers, fillers or combinations thereof, The synergists include phosphorus-containing compounds, The polyamide has a carboxylic acid end group / amine end group ratio greater than 1.

8.

2. The composition of claim 1, wherein the polyamide has a weight average molecular weight of 20,000 to 100,000 Daltons.

3. The composition of claim 1 wherein the polyamide has a z-average molecular weight of 30,000 to 600,000 Daltons.

4. The composition according to any one of claims 1 to 3, wherein the composition comprises 35 to 70 wt% polyamide, based on the total weight of the composition.

5. The composition according to any one of claims 1 to 4, wherein the composition comprises 5 to 25 wt% of a non-halogenated flame retardant, based on the total weight of the composition.

6. The composition according to any one of claims 1 to 5, wherein the composition comprises 0.1 to 15 wt% synergist, based on the total weight of the composition.

7. The composition according to any one of claims 1 to 6, wherein the composition further comprises 5 to 45 wt% glass fibers, based on the total weight of the composition.

8. The composition according to any one of claims 1 to 7, wherein the composition comprises 0.05 to 5 wt% of a heat stabilizer, based on the total weight of the composition.

9. A method of forming a molded product, comprising: a) forming a polyamide having a carboxylic acid / amine end group ratio greater than 1.8; b) compounding the polyamide with a non-halogenated flame retardant, a synergist, glass fibers, and one or more additives to form the flame retardant polyamide composition of claim 1, wherein the one or more additives include a flow modifier, a thermal stabilizer, a filler, or a combination thereof, wherein the synergist includes a phosphorus-containing compound; and c) molding the flame retardant polyamide composition to form a molded product.

10. The method of claim 9, wherein the polyamide has a weight average molecular weight of 20,000 to 100,000 Daltons.

11. The method of claim 9, wherein the polyamide has a z-average molecular weight of 40,000 to 600,000 Daltons.

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