Polyamide-imide polymers, polymer compositions, and articles containing the same, and methods for making the same

Abstract

The present invention relates to a method for preparing polyamide-imide (PAI) polymers by melt polymerization of at least one alicyclic acid component containing three carboxylic moieties selected from the group consisting of carboxylic acid, anhydride, and ester functional groups, and at least one diamine component, the method comprising maintaining the reaction mixture in a homogeneous liquid state during polymerization at a temperature of at least 200°C.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national stage entry of International Application No. PCT / EP2020 / 074992, filed September 8, 2020, which claims priority to U.S. Provisional Patent Application No. 62 / 897,473, filed September 9, 2019, the entire contents of each of which are incorporated herein by reference.

[0002] Polyamide-imide (PAI) polymers, polymer compositions containing same, methods for their production, and articles containing them are provided. [Background technology]

[0003] Polyamide-imides (PAIs) are high-performance polymers with exceptional thermal, chemical, and mechanical properties, making them suitable for demanding applications requiring high mechanical strength, stiffness, and low friction combined with high-temperature, corrosion, and wear resistance. For these reasons, they are widely used in the aerospace and automotive industries, as thermal insulation materials, coatings, solvent-resistant films, and in electronic devices.

[0004] PAIs are polymers that contain both amide and imide functional groups in the backbone. Thus, PAI polymers tend to exhibit hybrid properties of polyamides and polyimides. The increased rigidity of the imide groups not only confers superior hydrolytic, chemical, and thermal stability to the polymer, but also superior mechanical properties, especially for polymers based on aromatic monomers. Most commercially available PAI polymers are aromatic in nature, typically based on trimellitic acid, trimellitic anhydride, or halogenated trimellitic acid.

[0005] During the PAI preparation process, imides are formed from the reaction between two adjacent carboxylic acid groups (or their derivatives, such as acid halides, acid anhydrides, and esters) and a primary amine-containing molecule. An amic acid is first formed, which then closes to form an imide ring upon further elimination of a water molecule.

[0006] The imidization reaction typically requires high temperatures, especially for PAI polymers based on aromatic monomers. However, the use of high temperatures can result in crosslinking side reactions, leading to PAI polymers with limited processability, even thermoset-like structures. While the PAI polymers are chemically stable, their poor flowability during melt processing, poor handling at high temperatures (i.e., poor melt-processability) and poor solubility in conventional processing methods limit their use in certain applications.

[0007] Several attempts have been made to maintain the excellent thermal and mechanical performance of the PAI polymers while improving these properties, particularly by grafting the polymers, blending them with other types of polymers, and / or forming composites with additives or inorganic fibers.

[0008] Other attempts to improve the solubility and processability of PAI polymers involve the incorporation of flexible linkages and alicyclic units into the PAI polymer chain. For example, JP 2017-186560 A discloses a PAI based on cyclohexane-1,2,4-tricarboxylic-1,2-anhydride (CTA) (instead of trimellitic anhydride) and m-xylylenediamine (MXD). The method described in this publication is carried out in solution in an organic solvent. The use of organic solvents has significant drawbacks. First, recovery of the polymer after synthesis requires additional steps, such as precipitation of the polymer from a non-solvent and washing and drying the polymer. Second, some solvents are toxic. Third, polymers usually contain residual amounts of solvent, which can affect the polymer's mechanical performance or its use in certain applications. In other cases, the solvent can cause color problems.

[0009] US Patent Application Publication No. 2011 / 160407 describes a method for preparing PAI polymers by melt polymerization of at least one aromatic organic compound having a carboxyl group, at least one diamine compound, and optionally at least one diacid compound. This document more precisely describes the use of trimellitic acid, pyromellitic acid, or their anhydrides, esters, or amides as the aromatic organic compound. However, the aromaticity of these reactants imparts color (yellow to orange to red) to the polymer.

[0010] None of the above documents describe an organic solvent-free polymerization process for preparing PAI polymers, and the art would greatly benefit from this. Summary of the Invention

[0011] In a first aspect, a method for preparing a polyamide-imide (PAI) is provided, the method comprising: a) at least one alicyclic acid component containing three carboxylic moieties selected from the group consisting of carboxylic acid, anhydride, and ester functional groups; b) at least one diamine component; The method includes melt polymerizing a reaction mixture containing the compound (II) and the polymerizing agent (II) in a liquid state and at a temperature of at least 200°C during polymerization.

[0012] In a second aspect, there is provided a polyamide-imide (PAI) polymer obtainable by the method.

[0013] In a third aspect, a polymer composition is provided that includes the PAI polymer.

[0014] In a fourth aspect, an article is provided that includes the PAI polymer or the polymer composition. DETAILED DESCRIPTION OF THE INVENTION

[0015] A method for preparing polyamide-imide (PAI) polymers is provided. The method comprises melt polymerizing at least one cycloaliphatic acid component and at least one diamine component. The cycloaliphatic acid component comprises three carboxyl moieties selected from the group consisting of carboxylic acid, anhydride, and ester functional groups. The method further comprises maintaining the reaction mixture in a liquid state during polymerization at a temperature of at least 200°C.

[0016] Transparent, colorless PAI polymers with low branching and excellent mechanical properties are also provided, which can be processed into films and other articles using standard polymer processing techniques such as extrusion and injection molding.

[0017] PAI polymers exhibit low, controlled branching, which contributes to the optimized properties exhibited by PAI polymers, such as a combination of enhanced solubility, melt processability, and moldability combined with good thermal and mechanical properties, such as a high glass transition temperature (Tg). In particular, PAI polymers can be readily processed using conventional polymer processing techniques, such as extrusion and injection molding. Furthermore, PAI polymers can be readily converted into films and other articles. Articles comprising PAI polymers or polymer compositions containing PAI polymers are colorless, transparent, and have a low yellowness index.

[0018] As used herein, unless otherwise indicated, the following terms shall be construed as follows:

[0019] The term "alicyclic moiety" means an organic group that contains at least one aliphatic ring and no aromatic rings. The alicyclic moiety may be substituted with one or more linear or branched alkyl or alkoxy groups and / or halogen atoms, and / or may contain one or more heteroatoms in the ring, such as nitrogen, oxygen, and sulfur.

[0020] The term "alkyl" and derivative terms such as "alkoxy" include within their scope straight-chain, branched-chain, and cyclic moieties. Examples of alkyl groups are methyl, ethyl, 1-methylethyl, propyl, 1,1 dimethylethyl, and cyclopropyl. Unless otherwise specified, each alkyl group can be unsubstituted or substituted with one or more substituents, including, but not limited to, hydroxy, sulfo, C1-C6 alkoxy, and C1-C6 alkylthio, provided the substituents are sterically compatible and chemical bonding and strain energy rules are satisfied.

[0021] The term "halogen" or "halo" includes fluorine, chlorine, bromine and iodine, with fluorine being preferred.

[0022] Alicyclic acid component The PAI polymer is prepared from a reaction mixture comprising a cycloaliphatic acid component, a diamine component, and an optional diacid component. In a preferred embodiment, the cycloaliphatic acid component is represented by Formula (I) and / or (II): [ka] (In the formula: Z is an alicyclic moiety selected from the group consisting of substituted or unsubstituted monocyclic or polycyclic groups having 5 to 50 carbon atoms, preferably 6 to 18 carbon atoms; Y is ORa, Ra is H or alkyl, preferably alkyl having 1 to 5 carbon atoms, In formula (II), at least two Y(C=O) are bonded to two adjacent carbon atoms of Z, which means that at least two carboxyl moieties are in the ortho position relative to each other. Follow.

[0023] Preferably, Z is an alicyclic moiety containing 1 to 4 aliphatic rings. When Z contains multiple aliphatic rings, i.e., two or more aliphatic rings, the aliphatic rings may be fused together or may be directly or cross-linked to each other by the following bridges: -O-, -CH2-, -C(CH3)2-, -C(CF3)2-, or -(CF2)q-, where q is an integer of 1 to 5. The term "directly" means that the aliphatic rings are connected to each other via a bond.

[0024] Preferably, Z is selected from the group consisting of the formulas (III-A), (III-B), (III-C) and (III-D): [ka] and corresponding substituted structures, wherein X is —O—, —CH—, —C(CH)—, —C(CF)—, or —(CF)—, where q is an integer from 1 to 5.

[0025] In a preferred embodiment, the alicyclic acid component is represented by formula (Ia) and / or (IIa): [ka] Follow.

[0026] According to this embodiment, the method comprises: - melt polymerization of an alicyclic acid component according to formula (Ia) with at least one diamine component, - melt polymerization of an alicyclic acid component according to formula (IIa) and at least one diamine component, or - melt polymerization of a mixture of cycloaliphatic acid components according to formulae (Ia) and (IIa) and at least one diamine component, Includes.

[0027] Diamine component The reaction mixture in which the melt polymerization is carried out further comprises at least one diacid component. The diamine component used in the process may be aliphatic, cycloaliphatic, or aromatic. The diamine component comprises at least two amine moieties (—NH) and optionally at least one heteroatom, preferably selected from the group consisting of N, S, and O.

[0028] The diamine component is preferably represented by the following formula: H2N-R-NH2 (IV) where R is a C4 to C50 divalent hydrocarbon radical, particularly a divalent aliphatic, alicyclic, or aromatic hydrocarbon radical.

[0029] The diamine component is preferably selected from the group consisting of putrescine, cadaverine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,9-diaminononane, 2-methyl-1,8-diaminooctane, dodecamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), p-xylylenediamine, m-xylylenediamine, and mixtures thereof.

[0030] The diamine component may consist of a distinct diamine, for example a mixture of two or three distinct diamines.

[0031] Preferably, at least 50 mole percent, more preferably at least 65 mole percent, even more preferably at least 80 mole percent, and most preferably at least 95 mole percent of the diamine component is cycloaliphatic, based on the total number of moles of diamine in the diamine component.

[0032] According to an embodiment, the diamine component comprises a mixture of cycloaliphatic diamines, for example, two or three distinct cycloaliphatic diamines.

[0033] According to another embodiment, the diamine component consists of only one cycloaliphatic diamine. In such an embodiment, the diamine is preferably 1,3-bis(aminomethyl)cyclohexane.

[0034] Diacid component The reaction mixture in which the melt polymerization takes place optionally further comprises at least one diacid component or derivative thereof.

[0035] The expression "derivative thereof" refers to a derivative that is susceptible to reaction under polycondensation conditions to form an amide bond. Examples of diacid derivatives that form an amide bond include acyl groups, such as substituted or unsubstituted aliphatic acyl groups and aromatic acyl groups. Examples of acyl groups include, but are not limited to, formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, benzoyl, toluoyl, and xyloyl.

[0036] The diacid component may be aliphatic, alicyclic, or aromatic and optionally contains at least one heteroatom selected from the group consisting of N, S, and O.

[0037] The diacid component is preferably represented by the following formula: HOOC-R'-COOH(V) where R' is a C4 to C18 divalent hydrocarbon radical, particularly a divalent aliphatic, alicyclic, or aromatic hydrocarbon radical.

[0038] The diacid component is preferably selected from the group consisting of adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-bibenzoic acid, 5-hydroxyisophthalic acid, 5-sulfophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and mixtures thereof.

[0039] Melt polymerization The PAI polymers are provided by a process comprising melt polymerization of the above-identified components. More precisely, the process comprises combining an alicyclic acid component, a diamine component, and an optional diacid component to obtain a reaction mixture, and maintaining the reaction mixture in a liquid state during polymerization at a temperature of at least 200° C. The term “melt polymerization” means that the reaction mixture is maintained in a liquid state during polymerization at a temperature of at least 200° C.

[0040] In the context of the present invention, the phrase "maintained in a liquid state" means that the reaction mixture remains in a liquid state without solidification and / or precipitation of the resulting PAI polymer.

[0041] During polymerization, the reaction mixture is always heated to a high temperature so that the PAI polymer being prepared remains in a molten state. The minimum temperature to which the reaction mixture should be heated can usually be determined based on the melting or softening point of the PAI polymer being prepared. The melting or softening point of the PAI polymer being prepared can vary over the polymerization time depending on the amount of reactants involved in the reaction, particularly the amount of the limiting reactant, for example, if one of the reactants is added gradually to the reaction mixture. In this case, the melting or softening point of the PAI polymer being prepared can be determined based on the complete conversion of the limiting reactant monomer. Because the limiting reactant can be added to the reaction mixture sequentially, slight temperature increases / increments may be required to prepare the PAI polymer of the present invention. Each step of the polymerization process is then carried out at a temperature above the melting or softening point of the PAI polymer being produced.

[0042] The method is carried out in the absence of an organic solvent. In other words, the method does not include an organic solvent. That is, the reaction mixture does not include an organic solvent or includes an organic solvent in an amount of less than 1 wt. %, less than 0.5 wt. %, or even less than 0.2 wt. %, based on the total weight of the reaction mixture. The method may include water as a solvent.

[0043] In some embodiments, the process is carried out in the absence of added water or in the presence of added water in an amount of less than 50 wt. %, preferably less than 40 wt. %, more preferably less than 30 wt. %, even more preferably less than 15 wt. %, and most preferably less than 5 wt. %, based on the total weight of the reaction mixture.

[0044] Thus, the reaction mixture can be an aqueous solution containing the components identified above (i.e., at least one cycloaliphatic acid component, at least one diamine component, and optionally at least one diacid component). Preferably, the reaction mixture contains water as a solvent, since water facilitates stirring of the reaction mixture and therefore promotes its homogeneity.

[0045] According to various embodiments, either the alicyclic acid component and the diamine component are added sequentially, gradually, or continuously to the reaction mixture.

[0046] Preferably, the reaction mixture comprises the alicyclic acid component (“CAC”) and the diamine component (“DC”) in a ratio (CAC:DC) ranging from 0.8 to 1.2, preferably from 0.9 to 1.1, more preferably from 0.95 to 1.05, and even more preferably from 0.97 to 1.03.

[0047] When the process of the present invention employs a diacid component, the diacid component and / or diamine component may be introduced, at least in part, in the form of a salt of the diacid and / or diamine component.

[0048] PAI polymers are typically obtained by polycondensation between an alicyclic acid component, a diamine component, and an optional diacid component to form polyamide-imide chains with the formation of elimination products, particularly water. Preferably, the water formed during the process is distilled off at a pressure of 1 mbar to 30 bar, for example by fractional distillation using a condenser.

[0049] The reaction mixture is maintained in a liquid state during polymerization at a temperature of at least 200°C, preferably 215°C to 300°C, to distill off water (initially present in the reaction mixture and / or formed during polycondensation) while preventing the formation of a solid phase to prevent the mixture from solidifying.

[0050] The process can be carried out under pressure for at least part of the process. In these cases, a maximum pressure of 20 bar, preferably a maximum pressure of 10 bar, more preferably a maximum pressure of 3 bar is used. The end of the process is preferably carried out at low pressure (vacuum or atmospheric pressure) in order to drive the reaction to completion and to make it easier to remove the water formed during the process.

[0051] This process can be carried out in equipment made of materials inert to the above-identified components (i.e., the alicyclic acid component, the diamine component, and the optional diacid component). In this case, the equipment is selected to ensure sufficient contact between the components and to allow for the removal of volatile reaction products, especially water. Suitable equipment includes stirred reactors, extruders, and kneaders. The reaction vessel is preferably equipped with a stirring means, such as a rotating shaft.

[0052] To control the molecular weight of the resulting PAI polymer, a chain-limiting or end-capping agent may be added to the reaction mixture. Chain-limiting or end-capping agents are molecules that have only one site for reaction with amines and / or carboxylic acids. Examples of end-capping agents are monoamines such as benzylamine and 1-hexaneamine, and monocarboxylic acids such as acetic acid, propionic acid, benzoic acid, phthalic acid, or anhydrides.

[0053] Preferably, the order of introduction of the components into the reaction vessel during the process is as follows: water is charged first, then the diamine component, and finally the alicyclic acid component, and optionally the diacid component is added.

[0054] Preferably, an inert gas, such as nitrogen gas, is introduced into the reaction vessel to replace the atmosphere within the vessel. Preferably, the reaction vessel is purged with said inert gas both before and after charging all of the above-identified components. Preferably, the flow of inert gas is maintained throughout the process.

[0055] Polyamide-imide polymer There is also provided a polyamide-imide (PAI) polymer obtainable by the above-defined method.

[0056] Preferably, the PAI polymer has a Tg of at least 100°C, more preferably at least 120°C, even more preferably at least 140°C, and most preferably at least 150°C, as determined by DSC according to ASTM D3418.

[0057] Preferably, the PAI polymer has a Tg of at most 250°C, more preferably at most 240°C, even more preferably at most 230°C, and most preferably at most 220°C, as determined by DSC according to ASTM D3418.

[0058] Preferably, the PAI polymer has a number average molecular weight (Mn) of at least 5,000 g / mol, more preferably at least 10,000 g / mol, and even more preferably at least 15,000 g / mol, as determined by gel permeation chromatography (GPC) using a fluorinated solvent, two HFIP gel columns, and a UV-vis / refractive index detector.

[0059] Preferably, the PAI polymer has an Mn of at most 50,000 g / mol, more preferably at most 45,000 g / mol, and even more preferably at most 40,000 g / mol, as determined by gel permeation chromatography (GPC) using a fluorinated solvent, two HFIP gel columns, and a UV-vis / refractive index detector.

[0060] Advantageously, the PAI polymer is soluble in a variety of solvents, particularly hexafluoro-2-propanol, o-cresol, 98% sulfuric acid, and dimethylformamide.

[0061] The PAI polymer obtained by the method is in molten form and can therefore be formed directly or processed using conventional polymer processing techniques such as extrusion and injection molding for subsequent forming after melting.

[0062] Furthermore, the PAI polymers of the present invention can be easily converted into films and other articles. Because the PAI polymers of the present invention are soluble in a variety of organic solvents, films can be advantageously produced by casting a solution containing the PAI polymer and then evaporating the solvent, according to standard processes known to those skilled in the art. In particular, the films can be produced by dissolving the PAI polymer in a solvent to obtain a solution, casting the solution onto a substrate, and finally evaporating the solvent.

[0063] The PAI polymers can be used in many applications, particularly in the production of yarns, fibers or filaments, or films, or in the formation of articles by injection molding, extrusion, or extrusion / blow molding, especially in engineering plastic compositions.

[0064] polymer composition Also provided are polymer compositions comprising the PAI polymers.

[0065] Preferably, the PAI polymer is present in the polymer composition in an amount of at least 10 wt %, more preferably at least 15 wt %, even more preferably at least 20 wt %, and most preferably at least 25 wt %, based on the total weight of the polymer composition.

[0066] Preferably, the PAI polymer is present in the polymer composition in an amount of at most 99 wt%, more preferably at most 95 wt%, even more preferably at most 80 wt%, and most preferably at most 60 wt%, based on the total weight of the polymer composition.

[0067] According to one embodiment, the PAI polymer is present in the polymer composition in an amount ranging from 10 to 70 wt %, preferably from 20 to 60 wt %, based on the total weight of the polymer composition.

[0068] According to one embodiment, the polymer composition comprises at least one additional additive selected from the group consisting of reinforcing agents, colorants, dyes, pigments, lubricants, plasticizers, flame retardants, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fluxes, electromagnetic absorbers, and combinations thereof.

[0069] The reinforcing agent, also referred to as a reinforcing filler or fiber, may be selected from the group consisting of fibrous reinforcing fillers, particulate reinforcing fillers, and mixtures thereof. Fibrous reinforcing fillers are herein considered to be materials having a length, width, and thickness in which the average length is significantly greater than both the width and thickness. Generally, fibrous reinforcing fillers have an aspect ratio, defined as the average ratio between the length and the maximum width and thickness, of at least 5, at least 10, at least 20, or at least 50.

[0070] Fibrous reinforcing fillers include glass fibres, carbon or graphite fibres, and fibres formed from silicon carbide, alumina, titania, boron etc., and may include mixtures containing two or more such fibres. According to one embodiment, the fibres are flat fibres. Non-fibrous reinforcing fillers include talc, mica, titanium dioxide, potassium titanate, silica, kaolin, chalk, alumina, mineral fillers etc., among others.

[0071] Also provided is a method for providing a polymer composition, which comprises mixing a PAI polymer with the at least one additional additive. Preferably, mixing the PAI polymer with the at least one additional additive is performed by dry mixing and / or melt kneading. More preferably, mixing the PAI polymer with the at least one additional additive is performed by melt kneading, especially in a continuous or batch device. Such devices are well known to those skilled in the art. An example of a suitable continuous device is a screw extruder. Preferably, melt kneading is performed in a twin-screw extruder.

[0072] Goods Articles comprising the PAI polymer or the polymer composition are also provided.

[0073] The article is preferably a molded article, and preferably is molded from the PAI polymer or a polymer composition comprising said PAI polymer using methods well known in the art, such as, but not limited to, injection molding, blow molding, rotational molding, compression molding, or extrusion.

[0074] To the extent that the disclosure of any patents, patent applications, and publications incorporated herein by reference contradicts the statements of this application to the extent that the term may be unclear, the statements of this application shall control.

[0075] The present invention will now be described with reference to the following examples, which are for illustrative purposes only and are not intended to limit the scope of the claims. [Example]

[0076] material Cyclohexane-1,2,4-tricarboxylic-1,2-anhydride (CTA), available from Mitsubishi Gas Chemicals. 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), available from Mitsubishi Gas Chemicals. Hexamethylenediamine (HMDA), available from Ascend Performance Materials. 4,4'-methylenebis(cyclohexylamine) (PACM), available from Sigma-Aldrich. Phosphoric acid, available from Sigma-Aldrich.

[0077] method thermal analysis Thermal properties were determined using differential scanning calorimetry (DSC). DSC analysis was performed on a DSC Q200-5293 TA Instrument according to ASTM D3418. Each DSC run used three scans: a first heating cycle at 20.00°C / min to 300°C, a first cooling cycle at 20.00°C / min to 300°C, and a second heating cycle at 20.00°C / min to 300°C. The Tg was determined from the transition midpoint during the second heating cycle.

[0078] GPC Mn was measured by gel permeation chromatography (GPC) using fluorinated solvents, two HFIP gel columns, and a UV-vis / refractive index detector.

[0079] solubility A 5 mg sample of PAI polymer was added to 5 ml of solvent. The resulting mixture was stirred at room temperature for 24-48 hours, and the dissolution or softening of the sample was recorded. If the sample completely dissolved, it was considered soluble. If the sample showed no change in appearance after 48 hours, it was considered insoluble. Solubility in hexafluoro-2-propanol (HFIP), o-cresol, 98% sulfuric acid, and dimethylformamide (DMF) was tested.

[0080] Yellowness Test Films with thicknesses of 0.1-0.2 mm were prepared in a hot press (280°C, 2000 lb-f). The yellowness index was measured on the films using an X-Rite Ci7800 spectrophotometer.

[0081] Mechanical testing PAI1 polymer, synthesized as described below, was ground in a mill grinder and dried overnight under vacuum at 120°C. The resulting material was injection molded into Type V tensile bars according to ASTM D3641 using a mold temperature of 140°C, a melt temperature of 290°C, and an injection pressure of 6 bar. Mechanical testing was performed on injection-molded test specimens with a 0.3-inch gauge length according to ASTM D638 using an Instron 5569 machine at 23.2°C and 54.7% humidity. Notched Izod impact strength was measured according to ASTM D256 using injection-molded test specimens.

[0082] Synthesis method Polyamide-imide 1 (PAI1) CTA (53.9 g), 1,3-BAC (39.1 g), phosphoric acid (0.032 g), and deionized water (42 g) were placed in a 300 ml reactor. The reactor was then purged with nitrogen for 5 minutes, stirred, and heated to 280 °C within 2 hours to carry out the polymerization reaction. The generated steam was released after reaching the target temperature. The reactor was then evacuated, and the resulting molten polymer was then maintained at this condition for another 1 hour. After cooling, the polymer was removed from the reactor and used for analysis.

[0083] Polyamide-imide 2 (PAI2) CTA (55.6 g), 1,3-BAC (25.9 g), HMDA (11.7 g), phosphoric acid (0.032 g), and deionized water (42 g) were placed in a 300 ml reactor. The reactor was then purged with nitrogen for 5 minutes, stirred, and heated to 280 °C within 2 hours to carry out the polymerization reaction. The generated vapors were released after the target temperature was reached. The reactor was then evacuated, and the resulting molten polymer was then maintained at this condition for another 1 hour. After cooling, the polymer was removed from the reactor and used for analysis.

[0084] Polyamide-imide 3 (PAI3) CTA (50.7 g), PACM (27.1 g), HMDA (15.0 g), phosphoric acid (0.032 g), and deionized water (42 g) were placed in a 300 ml reactor. The reactor was then purged with nitrogen for 5 minutes, stirred, and heated to 280 °C within 2 hours to carry out the polymerization reaction. The generated vapors were released after the target temperature was reached. The reactor was then evacuated, and the resulting molten polymer was then maintained at this condition for another 1 hour. After cooling, the polymer was removed from the reactor and used for analysis.

[0085] result Table 1 shows the results of Tg, Mn, yellowness index, and solubility of the prepared PAI1, PAI2, and PAI3 polymers.

[0086] Table 2 shows the mechanical properties of PAI1.

[0087] [Table 1]

[0088] [Table 2]

[0089] As evidenced in Table 1 above, PAI polymers based on CTA and different diamines (1,3-BAC, HMDA, and PACM) were successfully prepared. The PAI polymers had number-average molecular weights greater than 19,000 g / mol and exhibited Tg values ​​ranging from 150 to 176°C. The Tg values ​​could be easily adjusted by varying the nature and amount of the diamine components.

[0090] The PAI polymers also exhibit a very low yellowness index.

[0091] Furthermore, these PAI polymers were found to be soluble in several organic solvents, indicating that their branching is minimal and controlled.

[0092] As shown in Table 2, PAI1 was melt processed and parts were fabricated by injection molding, demonstrating that PAI1 also exhibits melt processability and moldability. PAI1 also exhibits excellent mechanical properties, possessing a combination of high tensile modulus and strength.

Claims

1. a) Formula (Ia) and / or (IIa): at least one alicyclic acid component according to b) at least one diamine component selected from the group consisting of putrescine, cadaverine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,9-diaminononane, 2-methyl-1,8-diaminooctane, dodecamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), p-xylylenediamine, m-xylylenediamine, and mixtures thereof; 1. A method for preparing a polyamide-imide (PAI) polymer by melt polymerization of a reaction mixture comprising: at least 50 mol % of the diamine components are alicyclic, based on the total number of moles of diamine components involved in the process; maintaining the reaction mixture in a liquid state and at a temperature of at least 200°C during polymerization.

2. 10. The method of claim 1, wherein the reaction mixture further comprises at least one aliphatic, alicyclic, or aromatic diacid component or derivative thereof, wherein the diacid component is selected from the group consisting of adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-bibenzoic acid, 5-hydroxyisophthalic acid, 5-sulfophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and mixtures thereof.

3. 3. The process of claim 1 or 2, carried out in the absence of organic solvents and in the presence of added water in an amount of less than 50% by weight, based on the total weight of the reaction mixture.

4. The method according to any one of claims 1 to 3, wherein either the alicyclic acid component or the diamine component is added to the reaction mixture sequentially, gradually, or continuously.

5. 5. The process according to claim 1, wherein the water formed during the polymerization is distilled off by fractional distillation using a condenser at a pressure of from 1 mbar to 30 bar.

6. The PAI polymer has a glass transition temperature determined by DSC according to the ASTM D3418 standard, and the glass transition temperature is - at least 100°C, and / or - maximum 250°C, The method according to any one of claims 1 to 5.

7. The PAI polymer has a glass transition temperature determined by DSC according to the ASTM D3418 standard, and the glass transition temperature is - at least 140°C, and / or - maximum 220°C, The method according to any one of claims 1 to 6.

8. The PAI polymer has a number average molecular weight (Mn) determined by gel permeation chromatography using a fluorinated solvent, two HFIP gel columns, and a UV-vis / refractive index detector, and the number average molecular weight (Mn) is: - at least 5,000 g / mol, and / or - maximum 50,000 g / mol, The method according to any one of claims 1 to 7.

9. The PAI polymer has a number average molecular weight (Mn) determined by gel permeation chromatography using a fluorinated solvent, two HFIP gel columns, and a UV-vis / refractive index detector, and the number average molecular weight (Mn) is: - at least 10,000 g / mol, and / or - maximum 40,000 g / mol, The method according to any one of claims 1 to 8.

10. The method of any one of claims 1 to 9, wherein the PAI polymer is soluble in hexafluoro-2-propanol, o-cresol, 98% sulfuric acid, and / or dimethylformamide.

11. A method for preparing a polymer composition comprising a PAI polymer prepared by the method of any one of claims 1 to 10.

12. A method for producing an article comprising a PAI polymer prepared by the method of any one of claims 1 to 10 or a polymer composition prepared by the method of claim 11.

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