Water-dispersible copolyamide

Abstract

To provide a copolyamide that can be used as a support material for 3D printing, is water-dispersible, has a glass transition temperature of less than 200°C, possesses sufficient mechanical properties to function as a support material, and does not produce any emissions containing toxic residues. [Solution] The present invention provides a water-dispersible copolyamide mainly comprising at least four different polyamide units, wherein at least one of the polyamide units comprises at least one sulfonate group, and the polyamide sulfonate unit is present in a content of at least 15% by weight; and at least two of the polyamide units are derived from aliphatic monomers, and the copolyamide is understood to contain at least 15% by weight of sulfonate monomers and not exceeding 20% ​​by weight of caprolactam units.

Description

Technical Field

[0001] This patent application also relates to a water-dispersible copolyamide, a method for producing the same, and a composition containing the copolyamide useful as a support material in 3D printing.

Background Art

[0002] In additive manufacturing methods, three-dimensional objects are manufactured by adding materials rather than by subtraction as in conventional molding processes.

[0003] Among the particularly well-known manufacturing processes is the FDM (Fused Deposition Modeling) technique in which filaments of a material are deposited and fused to manufacture an article. In this process, generally, when the manufactured article has an overhang portion or a void segment, it is necessary to provide a support structure.

[0004] These support structures may be constructed via the same technique. The materials used, known as support materials or sacrificial materials, must meet a plurality of specific requirements, particularly having good mechanical properties at the melting point of the material used in the manufacture of the article, and thus must have a glass transition temperature higher than the melting point of the material used in the manufacture of the article. Further, if the support material must adhere to the material used to manufacture the article during construction, it must be easily removable from the article once construction is complete.

[0005] Particularly recognized support materials are those that are water-dispersible and can be removed simply by passing water through them.

[0006] For this purpose, Brochure International Patent Application Publication No. 2016 / 205690A1 proposes sulfopolyamides, sulfopolyesters, or sulfopolyurethanes obtained by copolymerization with sulfonate monomers, more specifically with sodium or lithium salts of 5-sulfoisophthalic acid (5-SSIPA, CAS No. 6362-79-4). The aforementioned document describes two specific sulfopolyamides, 6I / 6T / 6SSIPA and 12 / MACMI / MACMSSIPA. However, it does not provide any details regarding their synthesis or their properties, such as their inherent viscosity or water dispersibility. Obtaining these polymers with sufficient molar mass to ensure the required mechanical properties is difficult.

[0007] Furthermore, their high glass transition temperature (approximately 200°C), associated with the presence of ionic groups, suggests a very high melt viscosity.

[0008] Specific copolyamide sulfonates are described further for other applications. For example, International Patent Application Publication No. 2011 / 147739A1 describes copolyamides obtained by polycondensation of hexamethylenediamine and adipic acid salts with a small amount of lithium 5-sulfoisophthalic acid salt for gas and liquid barrier properties. U.S. Patent No. 5,889,138 describes copolyamide sulfonates for improving the stain resistance of polyamide fibers. The specifically described copolyamide 66 / 6SSIPA has a glass transition temperature (Tg) that is too low for use in 3D printing with most materials. Furthermore, the water dispersibility of these copolyamides is usually insufficient for their intended applications.

[0009] Furthermore, European Patent Application No. 0696607A1 describes a caprolactam-based copolyamide sulfonate as a film-forming agent useful for preparing hair fixatives. Finally, French Patent Invention No. 2172973 describes such a copolyamide sulfonate for improving the dyeing ability of polyamide fibers. Currently, due to the incomplete polymerization of caprolactam, these copolyamides have high content of residual monomers, cyclic dimers, and higher-order cyclic oligomers. Due to the toxicity of these compounds, it is desirable to limit the use of these copolyamides.

[0010] Therefore, there is still a need to propose a copolyamide that is water-dispersible, has a glass transition temperature of less than 200°C, especially less than 150°C, possesses sufficient mechanical properties to function as a support material, and does not produce any emissions containing toxic residues. [Overview of the Initiative]

[0011] Therefore, according to a first aspect, one subject of the present invention is a water-dispersible copolyamide comprising at least four different polyamide units, -At least one of the polyamide units contains at least one sulfonate group, and the polyamide sulfonate unit is present in an amount of at least 15% by weight. - At least two of the polyamide units are derived from aliphatic monomers, It is understood that the aforementioned copolyamide contains caprolactam units not exceeding 20% ​​by weight.

[0012] In one embodiment, the water-dispersible copolyamide comprises at least five different polyamide units.

[0013] In one embodiment, a water-dispersible copolyamide is given by formula (I) A / X1Y1 / X2Y2 / X3Y3 / X4Z (I) During the ceremony, -A is a unit obtained from at least one lactam or aminocarboxylic acid containing at least six carbon atoms, -X1Y1 is a unit obtained from an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X1 and an aliphatic or aromatic dicarboxylic acid Y1. -X2Y2 is a unit obtained from an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X2 and an aliphatic or aromatic dicarboxylic acid Y2. -X3Y3 is a unit obtained from an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X3 and an aliphatic or aromatic dicarboxylic acid Y3. -X4Z is an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X4 containing 4 to 12 carbon atoms, and formula SO3 containing 4 to 18 carbon atoms where X may be hydrogen, a quaternary ammonium group, or a monovalent metal. - X + The unit is obtained from a sulfonate compound Z selected from aromatic dicarboxylic acid sulfonates, aliphatic sulfonates, or esters thereof, having at least one of the groups.

[0014] In one embodiment, the copolyamide does not contain more than 10% by weight of alicyclic diamine residues.

[0015] In one embodiment, the copolyamide of formula (I) is a lactam or an aminocarboxylic acid containing 10 to 12 carbon atoms, particularly selected from 11-aminoundecanoic acid and lauryl lactam.

[0016] In one embodiment, the copolyamide of formula (I) is selected from 1,2-ethylenediamine, 1,6-hexamethylenediamine, 1,9-nonanediamine, and 1,10-decanediamine, where X1, X2, X3, and X4 are the same or different.

[0017] In one embodiment, the copolyamide of formula (I) is selected from adipic acid, azelaic acid, sebacic acid, and dodecanediic acid, with Y1 and Y2 being the same or different.

[0018] According to one embodiment, the copolyamide has the formula (I) where Y3 is isophthalic acid.

[0019] According to one embodiment, the sulfonate compound is selected from the sodium, lithium or potassium salts of 5-sulfoisophthalic acid and the sodium, lithium or potassium salts of the methyl diester of 5-sulfoisophthalic acid.

[0020] According to one embodiment, the water-dispersible copolyamide comprises 0 to 30% by weight of unit A, 0 to 30% by weight of unit X1Y1, 0 to 30% by weight of unit X2Y2, 0 to 30% by weight of unit X3Y3, and 10% to 50% by weight of unit X4Z, and it is understood that the copolyamide contains at least four different polyamide units.

[0021] According to one embodiment, the water-dispersible copolyamide contains at least 40% by weight of aromatic units.

[0022] According to one embodiment, the water-dispersible copolyamide has a glass transition temperature between 100 and 140 °C, preferably between 110 and 130 °C.

[0023] According to one embodiment, the water-dispersible copolyamide has an intrinsic viscosity greater than 0.4 dl / g, preferably greater than 0.5 dl / g, particularly greater than 0.6 dl / g.

[0024] According to a second aspect, the present invention a. providing monomers selected from lactams, aminocarboxylic acids, and diamines and diacids respectively in appropriate numbers and ratios; b. the step of polycondensation of the monomers in the presence of one or more catalysts and / or chain limiters under conditions suitable for obtaining the copolyamide, if appropriate, and if necessary, the step of granulating the copolyamide relates to a method for producing the water-dispersible copolyamide, comprising the above steps.

[0025] Finally, according to a third aspect, the present invention relates to a composition comprising the water-dispersible copolyamide in particular in the form of a filament. [Modes for carrying out the invention]

[0026] Definition of Terms The term "polymer" is intended to refer to a polymer derived from the copolymerization of at least two chemically distinct types of monomers, called comonomers. Thus, a copolymer is formed from at least two repeating units; it may be formed from three or more repeating units. It can be any of the enumerated types of copolymers, particularly random copolymers or block copolymers. Preferably, it is a random copolymer.

[0027] The term "polyamide" (homopolyamide or copolyamide) is intended to refer to any polymer essentially formed from units or monomers linked to one another via amide groups, such as lactams, amino acids and / or diacids, and diamines. However, polymers further containing units or monomers linked to one another via other groups, such as ester, urethane, or urea groups, are also targeted if these units are present in small amounts.

[0028] The term "polyamide monomer or unit" should be interpreted in the context of this specification as meaning "repeating unit," as the case where the repeating unit of a polyamide consists of a combination of a diamine and a diamine is a special case. This is considered to be a combination of a diamine and a diamine, i.e., a diamine-diamine pair (equomolar amount), and is thought to correspond to a monomer. This is because, individually, a diamine or diamine is merely a structural unit and is insufficient for polymerization on its own. Polyamide units may be particularly aliphatic, aromatic, and / or semi-aromatic.

[0029] The term "sulfonate compound" is intended to indicate a compound that can react by polycondensation containing a group -SO3X where X may be hydrogen, a quaternary ammonium group, or a monovalent metal. Preferably, the sulfonate group is supported by a dicarboxylic acid.

[0030] The term "copolyamide" (abbreviated as CoPA) means a polymerization product of at least two, in the context of the present invention, four or more, and in particular six, seven or eight different monomers.

[0031] The term "water-dispersible" is used to describe the characteristics of a material that disintegrates in an aqueous solution that does not contain agents that promote its disintegration or dissolution, such as a base (sodium hydroxide) or an acid. In other words, it is water that disintegrates or dissolves the material. Preferably, the water has a neutral pH at that time, i.e., a pH of about 5 to 9. Preferably, the material is water-dispersible not only in desalinated water but also in water containing various mineral salts, such as tap water. During the disintegration process, the material can break down into smaller fragments and / or particles of polymer. Some of the material may also dissolve.

[0032] The term "intrinsic viscosity" refers to viscosity measured according to the modified standard ISO 307:2007, with the solvent being m-cresol instead of sulfuric acid, the concentration being 0.5% by weight, and the temperature being 20°C. Intrinsic viscosity makes it possible to assess the molar mass of the polymer.

[0033] The term "filament" refers to a thread of variable thickness, generally 10 μm to 10 mm, preferably 50 μm to 5 mm, of fusible material optionally reinforced with fillers, suitable for use in 3D printers, particularly FDM technology.

[0034] The term "melting point" is intended to indicate the temperature at which at least partially crystalline polymers become a viscous liquid state, as measured by differential scanning calorimetry (DSC) according to the NF EN ISO 11357-3 standard, using a heating rate of 20°C / min.

[0035] The term "glass transition temperature" is intended to indicate the temperature at which at least partially amorphous polymers transition from a rubbery state to a glassy state, or vice versa, when measured by differential scanning calorimetry (DSC) according to the NF EN ISO 11357-2 standard, using a heating rate of 20°C / min.

[0036] The nomenclature used to define polyamides is described in the ISO 1874-1:2011 standard "Plastics - Polyamide (PA) molding and extrusion materials - Part 1: Designation," particularly on page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0037] The term "aromatic unit" is intended to refer to polyamide units derived from polycondensation of a non-aromatic diamine with an aromatic diacid, polycondensation of a diamine containing an aromatic unit with a non-aromatic diacid, or alternatively, polycondensation of a diamine containing an aromatic unit with an aromatic diacid.

[0038] [Copolyamide] This invention proposes a water-dispersible copolyamide that is particularly useful as a support material in 3D printing.

[0039] For usefulness in this application, the material preferably combines the following properties. - Good water dispersibility, including tap water and after long-term storage. - A glass transition temperature close to the glass transition temperature of the substrate, -At the temperature at which 3D printing is performed, • Sufficient mechanical strength and rigidity to support printed parts. • A melt viscosity close to the melt viscosity of the substrate, and - Formation of spills that can be dispersed in water and removed without danger.

[0040] Current tests have revealed that copolyamide sulfonates containing two different polyamide units do not disperse in water, even when they contain high levels of sulfonate monomers. Furthermore, while migration to terpolyamide can improve water dispersibility, this improvement is not persistent and rather shows significant degradation over time. This observation can be explained by the slight crystallization of the polyamide, which reduces its solubility in water.

[0041] On the other hand, the applicant found that adding additional polyamide units to these terpolyamides, selected such that at least two of the polyamide units of the resulting copolyamide are aliphatic, enables the preparation of copolyamides that meet the requirements, namely a high glass transition temperature combined with excellent water dispersibility in tap water at 70°C, even after 15 days of conditioning.

[0042] Furthermore, the applicant identified the minimum required sulfonate monomer content in the copolyamide to ensure good water dispersibility.

[0043] Therefore, according to the present invention, a copolyamide comprising at least four, preferably five, different polyamide units is proposed. -At least one of the polyamide units comprises at least one sulfonate group, - At least two of the polyamide units are derived from aliphatic monomers, The copolyamide is understood to contain at least 15% by weight of sulfonate monomers and not exceeding 20% ​​by weight, preferably not exceeding 15% by weight, more preferably not exceeding 10% by weight, and particularly not exceeding 5% by weight of caprolactam units.

[0044] Conveniently, copolyamides are given by formula (I) A / X1Y1 / X2Y2 / X3Y3 / X4Z (I) During the ceremony, -A is a unit obtained from at least one lactam or aminocarboxylic acid containing at least six carbon atoms, -X1Y1 is a unit obtained from an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X1 and an aliphatic or aromatic dicarboxylic acid Y1. -X2Y2 is a unit obtained from an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X2 and an aliphatic or aromatic dicarboxylic acid Y2. -X3Y3 is a unit obtained from an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X3 and an aliphatic or aromatic dicarboxylic acid Y3. -X4Z is an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X4 containing 4 to 12 carbon atoms, and formula SO3 containing 4 to 18 carbon atoms where X may be hydrogen, a quaternary ammonium group, or a monovalent metal. - X + The unit is obtained from a sulfonate compound Z selected from aromatic dicarboxylic acid sulfonates, aliphatic sulfonates, or esters thereof, having at least one of the groups.

[0045] According to the present invention, at least two of the polyamide units of the copolyamide are aliphatic. If Z is derived from an aromatic dicarboxylic acid, then unit X4Y is not aliphatic. In addition, at least two of the polyamide units A, X1Y1, X2Y2, and X3Y3 of the copolymer of formula (I) are aliphatic in this case.

[0046] When unit A is obtained from a lactam, the lactam may be selected from caprolactam, oenantractam, caprylolactam, pelargolactam, decanolactam, undecanolactam, and lauryllactam, particularly lauryllactam.

[0047] When unit A is obtained from the polycondensation of amino acids, unit A may be selected from 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminoundecanoic acid and 11-aminododecanoic acid and their derivatives, in particular N-heptyl-11-aminoundecanoic acid, and especially 11-aminoundecanoic acid.

[0048] However, since the aforementioned compounds polymerize incompletely and are toxic, it is preferable to avoid using caprolactam.

[0049] Advantageously, unit A is obtained from at least one lactam or aminocarboxylic acid containing at least 7, preferably at least 8, particularly at least 9, most particularly at least 10, particularly 11, and preferably at least 12 carbon atoms.

[0050] Preferably, A is derived from a lactam or aminocarboxylic acid containing 10 to 12 carbon atoms. Among these monomers, aminoundecanoic acid and lactam 12 are particularly preferred. Preferably, unit A is an aliphatic unit.

[0051] The diamines from which groups X1, X2, X3, and X4 are derived may be the same or different aliphatic, alicyclic, heterocyclic, or arylaliphatic diamines.

[0052] Preferably, the diamines each independently contain 2 to 18 carbon atoms, preferably 4 to 12, and more particularly 6 to 10 carbon atoms.

[0053] Advantageously, the diamine is selected from linear aliphatic diamines, particularly 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonameethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, and 1,18-octadecamethylenediamine. Preferably, the diamines X1, X2, X3, and X4 are selected from 1,2-ethylenediamine, 1,6-hexamethylenediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine. More specifically, the diamines X1, X2, X3, and X4 may be selected from 1,2-ethylenediamine, 1,6-hexamethylenediamine, 1,9-nonamethylenediamine, and 1,10-decamethylenediamine.

[0054] The diamine may also be selected from branched aliphatic diamines, such as 2,2,4-trimethyl-1,6-hexamethylenediamine and 2-methyl-1,5-pentamethylenediamine.

[0055] The diamine can also be selected from alicyclic diamines, particularly isophorone diamine (IPD), bis(3-methyl-4-aminocyclohexyl)methane (MACM), 2,2-bis(3-methyl-4-aminocyclohexyl)propane (MACP), p-bis(aminocyclohexyl)methane (PACM), 2,6-bis(aminomethyl)norbornane (BAMN), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), and 1,4-bis(aminomethyl)cyclohexane (1,4-BAC).

[0056] Furthermore, at least certain diamines X1, X2, X3, or X4 may be arylaliphatic diamines, and may be selected from metaxylylenediamine (MXD) and paraxylylenediamine (PXD).

[0057] Finally, at least certain diamines X1, X2, X3, or X4 may be heterocyclic diamines, and can be selected from piperazine (Pip) and N-aminoethylpiperazine (AEP).

[0058] The dicarboxylic acid derived from group Y1 may be an aliphatic diacid containing 6 to 18 carbon atoms, preferably 6 to 12, and especially 8 to 10 carbon atoms. It is preferably a linear dicarboxylic acid. Advantageously, it is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic acid, brassic acid, tetradecanediic acid, pentadecanediic acid, hexadecanedioic acid, and octadecanediic acid. Preferably, Y1 is selected from adipic acid, azelaic acid, sebacic acid, and dodecanediic acid.

[0059] The dicarboxylic acids derived from groups Y2 and Y3 are aliphatic or aromatic dicarboxylic acids, which may be the same or different. Preferably, diacids Y2 and Y3 independently contain 6 to 18 carbon atoms, preferably 6 to 12, and especially 8 to 10 carbon atoms. If it is an aliphatic dicarboxylic acid, dicarboxylic acid Y1 can be selected from the list mentioned above. Advantageously, it can be selected from adipic acid, azelaic acid, sebacic acid, and dodecanediic acid. If it is an aromatic acid, it can be particularly selected from terephthalic acid, 2,6-naphthalenedicarboxylic acid, and isophthalic acid, with isophthalic acid being preferred.

[0060] According to one embodiment, Y1 and Y2 are selected from adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid. According to one embodiment, Y3 is isophthalic acid.

[0061] The polyamide unit X1Y1 is preferably selected from PA26, PA29, PA210, PA212, PA66, PA69, PA610, PA612, PA96, PA99, PA910, PA912, PA106, PA109, PA1010, PA1012, PA2I, PA6I, PA9I, and PA10I.

[0062] The polyamide unit X2Y2 is preferably selected from PA26, PA29, PA210, PA212, PA66, PA69, PA610, PA612, PA96, PA99, PA910, PA912, PA106, PA109, PA1010, PA1012, PA2I, PA6I, PA9I, and PA10I.

[0063] The polyamide unit X3Y3 is preferably selected from PA26, PA29, PA210, PA212, PA66, PA69, PA610, PA612, PA96, PA99, PA910, PA912, PA106, PA109, PA1010, PA1012, PA2I, PA6I, PA9I and PA10I, PA2T, PA6T, PA9T and PA10T.

[0064] Sulfonate monomers are preferably derived from dicarboxylic acids or their esters and diamines having at least one sulfonate group. Preferably, the dicarboxylic acids or ester sulfonates are used in the form of alkali metals (particularly sodium, lithium, or potassium), alkaline earth metals, or quaternary ammonium sulfonates. The dicarboxylic acids or ester sulfonates further have two acid or ester functional groups attached to one or more aromatic rings if they are aromatic dicarboxylic acids, or to an aliphatic chain if they are aliphatic dicarboxylic acids.

[0065] Suitable sulfonate compounds include aromatic dicarboxylic acids or anhydride sulfonates, such as sulfoisophthalic acid, sulfoterephthalic acid, or sulfo-orthophthalic acid or anhydride, sulfo-4-naphthalene-2,7-dicarboxylic acid or anhydride, and aliphatic dicarboxylic acids or anhydride sulfonates, such as sulfosuccinate dioic acid or anhydride or their lower diesters (methyl, ethyl, propyl, isopropyl, butyl).

[0066] The preferred sulfonate compounds are sodium, lithium, or potassium salts of sulfisophthalic acid and sulfosuccinic acid or anhydride, and their methyl diesters. Preferably, the sulfonate compounds are lithium salt of 5-sulfisophthalic acid (abbreviated as LiSIPA), sodium salt of 5-sulfisophthalic acid (hereinafter abbreviated as SSIPA), potassium salt of 5-sulfisophthalic acid (abbreviated as KSIPA), or their methyl diesters (abbreviated as LiSIPMe, SSIPMe, and KSIPMe, respectively).

[0067] The unit X4Z is preferably selected from 2SSIPA, 6SSIPA, 9SSIPA, 10SSIPA, 2LiSIPA, 6LiSIPA, 9LiSIPA, 10LiSIPA, 2KSIPA, 6KSIPA, 9KSIPA, 10KSIPA, 2SSIPMe, 6SSIPMe, 9SSIPMe, 10SSIPMe, 2LiSIPMe, 6LiSIPMe, 9LiSIPMe, 10LiSIPMe, 2KSIPMe, 6KSIPMe, 9KSIPMe, and 10KSIPMe. 2SSIPA, 6SSIPA, 6LiSIPA, and 6SSIPMe are particularly preferred.

[0068] Where appropriate, the water-dispersible copolyamide according to the present invention may also contain other additional monomers represented by formula (I). In particular, it may contain one, two or more further monomers X as defined above. n Y n It may also contain other non-polyamide monomers. Furthermore, the copolyamide may contain other non-polyamide monomers.

[0069] The copolyamide according to the present invention may contain 2, 3, 4, or 5 aliphatic polyamide units. Preferably, it contains 2 or 3 aliphatic polyamide units.

[0070] The weight ratios of various polyamide units in a copolyamide can vary considerably.

[0071] However, in order to raise the glass transition temperature sufficiently, that is, preferably above 100°C, the copolyamide preferably contains more than 40% by weight, preferably more than 45%, and in particular more than 50% by weight of aromatic units.

[0072] Furthermore, to ensure sufficient water dispersibility, the mass content of sulfonate monomers in the copolyamide is at least 20%, preferably at least 25%, advantageously at least 30%, and particularly at least 35%, relative to the weight of the total monomers.

[0073] Advantageously, the mass content of sulfonate monomers in the copolyamide is 15% to 70%, particularly 20% to 60%, particularly 20% to 50%, preferably 25% to 40%, and more preferably 25% to 35%, relative to the weight of the total monomers.

[0074] Furthermore, the copolyamide preferably contains a low mass percentage, preferably 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, or polyamide units derived from alicyclic diamines.

[0075] According to one embodiment, the copolyamide comprises weight-based units A in 0-30%, particularly 5-25%, and especially 10-20%, weight-based units X1Y1 in 0-30%, particularly 5-25%, and especially 10-20%, weight-based units X2Y2 in 0-30%, particularly 5-25%, and especially 10-20%, weight-based units X3Y3 in 0-30%, particularly 5-25%, and especially 10-20%, and weight-based units X4Z in 15-70%, particularly 20-50%, particularly 25-45%, and especially 25-35%, and it is understood that the copolyamide comprises at least four different polyamide units.

[0076] No destructive effect on water dispersibility has been observed with respect to excess carboxylic acid or amine groups at the ends of copolyamide chains. Nevertheless, it is preferable that copolyamides have substantially equivalent amounts of chain-termining carboxylic acid and amine groups.

[0077] According to one embodiment, the length and end-chain functionality of the copolyamide according to the present invention are modified by adding at least one suitable monofunctional or bifunctional chain limiter.

[0078] Such suitable chain restrictors may be linear aliphatic C2-C18 monocarboxylic acids and / or linear aliphatic C4-C18 monoamines. Alternatively, they may be linear aliphatic C3-C36 dicarboxylic acids or linear aliphatic C4-C18 diamines.

[0079] Acids used as chain limiters can be selected from, for example, acetic acid, lauric acid, stearic acid, adipic acid, azelaic acid, sebacic acid, and dodecanediic acid.

[0080] Preferably, the copolyamide according to the present invention is limited to linear aliphatic C2-C18 monocarboxylic acids and / or linear aliphatic C6-C12 dicarboxylic acids, and particularly preferably linear aliphatic C6-C12 dicarboxylic acids, adipic acid, sebacic acid, and dodecanediic acid.

[0081] The amines used as chain limiting agents may be selected from, for example, laurylamine, hexanediamine, and decanediamine.

[0082] Preferably, the copolyamide according to the present invention is limited to C6-C12 monoamines and / or C6-C12 diamines, with hexanediamines and laurylamines being particularly preferred.

[0083] Chain restrictors are generally added in amounts significantly less than the monomers. Generally, their content in the monomer mixture is less than 1% by weight, preferably less than 0.5% by weight, or even less than 0.2% by weight, relative to the weight of the monomer mixture.

[0084] To ensure sufficient mechanical strength, the copolyamide according to the present invention preferably has an intrinsic viscosity of more than 0.4 dl / g, more preferably more than 0.5 dl / g, and especially more than 0.6 dl / g.

[0085] In one embodiment, the copolyamide has a glass transition temperature between 100 and 140°C, preferably between 110 and 130°C. Copolyamides with higher transition temperatures risk having a lower molar weight due to their higher viscosity, and consequently risk having insufficient mechanical properties.

[0086] [Method for producing copolyamide] According to a second aspect, the present invention relates to a method for preparing the copolyamide described above.

[0087] Generally, methods for producing water-dispersible copolyamides are: a. A step of providing monomers selected from lactams, aminocarboxylic acids, and diamines and diacids in appropriate numbers and proportions. b. Where appropriate, a step of polycondensation of monomers in the presence of one or more catalysts and / or chain limiters under conditions suitable for obtaining the copolyamide, and c. Granulation of the copolyamide, if necessary. Includes.

[0088] The copolyamides described are known to those skilled in the art and can be obtained by any of the polycondensation processes described in particular in the Nylon Plastics Handbook, Ed. Melvin I. Kohan, Hanser Publishers 1995, pages 17 to 27.

[0089] For example, in one embodiment, polycondensation is carried out in a single step within the same reactor at a temperature of 200 to 300°C, particularly a temperature higher than the melting point of the copolyamide sulfonate, at a pressure that can be raised to 30 bar and then gradually reduced to below atmospheric pressure in order to complete the polymerization. The reaction temperature in this polycondensation step is preferably higher than the melting point of the copolyamide in order to ensure effective stirring.

[0090] The catalyst may be phosphoric acid and / or phosphorous acid, hypophosphorous acid, and phosphorus-based acids such as sodium or potassium salts of these acids. The chain restrictor can be selected from the above.

[0091] Therefore, the reaction produces oligomers as intermediates, which condense with each other to directly produce polyamides in the same reactor. Optionally, the polymers may be removed from the reactor at a pressure higher than atmospheric pressure. Polymerization may then be completed, optionally, by an extrusion step at a temperature higher than the melting point, or by a heating step at a temperature lower than the melting point of the polyamide according to a “solid polymerization” process.

[0092] Alternatively, the polycondensation process is carried out in three steps, including the following: (i) A first step of prepolymerization in a first reactor, wherein the temperature is preferably higher than the melting point of the prepolymer, by heating the comonomer at a temperature of 200°C to 300°C, particularly at a pressure of 20 to 30 bar, to obtain a prepolymer. (ii) A second step in which the prepolymer is transferred from the first reactor to the second reactor at a temperature of 220-280°C and a pressure of 2-30 bar. (iii) A third step of polymerization, wherein the temperature is particularly high above the melting point of the copolyamide, the heating is performed at a temperature of 200-300°C at a pressure which may be in the range of up to 30 bar, and the pressure is gradually reduced to below atmospheric pressure to complete polymerization and obtain a copolyamide.

[0093] Optionally, the polymer after polymerization in step c may be removed from the second reactor at a pressure higher than atmospheric pressure.

[0094] Polymerization may be completed by extruding at a temperature above the melting point, or by heating at a temperature below the melting point of the polyamide according to a "solid polymerization" process.

[0095] Advantageously, the copolyamide sulfonate is then recovered by cooling without direct contact with water.

[0096] [Compositions containing copolyamides] According to a third aspect, the present invention relates to compositions comprising the above-mentioned copolyamide. Such formulations may, in particular, result from the addition of conventional additives and / or fillers to polymer formulations.

[0097] Therefore, the composition may contain 0 to 10% by weight, preferably 1% to 8% by weight, and particularly 2% to 5% by weight, of one or more common additives such as colorants, pigments, dyes, anti-UV agents, anti-aging agents, antioxidants, fluidizers, anti-wear agents, release agents, stabilizers, plasticizers, surfactants, fluorescent whitening agents, or waxes. Furthermore, the composition may contain fillers or reinforcing agents as appropriate.

[0098] Copolyamide alone, or copolyamides formulated as described above, can then be formed into shapes suitable for their use. When copolyamides are used in 3D printing, they can be formed into filaments, for example, by extrusion.

[0099] [Uses of Copolyamides] According to a fourth aspect, the present invention relates particularly to the use of copolyamide as a support material as described in 3D printing.

[0100] Specifically, the described copolyamides have excellent water dispersibility in water, including tap water, and similarly possess a glass transition temperature that provides sufficient mechanical strength at the polyamide transformation temperature, even after long-term storage.

[0101] Advantageously, the copolyamide can be dispersed in tap water.

[0102] To obtain rapid dispersion, the copolyamide is preferably dispersed in hot water. Preferably, the temperature of the water used to disperse the copolyamide is 40-90°C, preferably 50-80°C, and especially 60-80°C.

[0103] The present invention will be described in more detail in the following examples. Unless otherwise specified, percentages are weight percentages relative to the weight of the final composition. [Examples]

[0104] Example 1 9.00 g of aminoundecanoic acid, 18.55 g of hexamethylenediamine, 7.06 g of isophthalic acid, 5.01 g of adipic acid, 5.72 g of sebacic acid, 14.66 g of sodium 5-sulfoisophthalic acid, 0.14 g of phosphoric acid in 8.5% water, 0.08 g of sodium hypophosphate in 60% water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over 30 minutes under a nitrogen stream. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. Under these conditions, after 140 minutes, the tubular reactor containing the resulting polymer is cooled with ambient air.

[0105] Next, the obtained copolyamide having the composition shown in Table 2 was pulverized into granules of several millimeters in size, and then its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were characterized and evaluated as follows.

[0106] The glass transition temperature was measured by differential scanning calorimetry (DSC) according to the standard NF EN ISO 11357-2, using a heating rate of 20°C / min.

[0107] Water dispersibility was evaluated by introducing 0.5 g of copolyamide into a suitable container equipped with a stirrer, containing 150 g of tap water heated to 70°C. Evaluation was performed once immediately after synthesis and once after 15 days of conditioning (23°C, 50% RH). The water dispersibility of the resulting dispersion was evaluated by visual inspection for 10 minutes and classified into one of the categories shown in Table 1 below. JPEG2026062700000001.jpg55170

[0108] MVI: Evaluated under a 5 kg load at 220°C according to standard ISO 1133-1 (2011).

[0109] Intrinsic viscosity was evaluated by applying the modified standard ISO 307:2007, with the solvent being m-cresol instead of sulfuric acid, the concentration being 0.5 wt%, and the temperature being 20°C.

[0110] The results are summarized in Table 3 below.

[0111] Example 2 9.00 g of aminoundecanoic acid, 18.55 g of hexamethylenediamine, 7.06 g of isophthalic acid, 5.01 g of adipic acid, 5.72 g of sebacic acid, 13.77 g of lithium salt of 5-sulfoisophthalic acid, 0.14 g of phosphoric acid in 8.5% water, 0.08 g of sodium hypophosphite in 60% water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over 30 minutes under a nitrogen stream. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. Under these conditions, after 41 minutes, the tubular reactor containing the resulting polymer is cooled with ambient air.

[0112] Next, the obtained copolyamide having the composition shown in Table 2 was pulverized into granules of several millimeters in size, and then, as described in Example 1, its characteristics with respect to its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were clarified. The results are summarized in Table 3 below.

[0113] Example 3 9.00 g of aminoundecanoic acid, 18.55 g of hexamethylenediamine, 7.06 g of isophthalic acid, 5.01 g of adipic acid, 5.72 g of sebacic acid, 16.18 g of sodium methyl diester of 5-sulfoizophthalic acid, 0.14 g of phosphoric acid in 8.5% water, 0.08 g of sodium hypophosphite in 60% water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over a nitrogen stream for 30 minutes. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. After 30 minutes under these conditions, the tubular reactor containing the resulting polymer is cooled with ambient air.

[0114] Next, the obtained copolyamide having the composition shown in Table 2 was pulverized into granules of several millimeters in size, and then, as described in Example 1, its characteristics with respect to its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were clarified. The results are summarized in Table 3 below.

[0115] Example A (Comparative Example) 22.78 g of hexamethylenediamine, 18.38 g of adipic acid, 18.84 g of sodium salt of 5-sulfoisophthalic acid, 0.14 g of phosphoric acid in 8.5% water, 0.08 g of sodium hypophosphite in 60% water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over 30 minutes under a nitrogen stream. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. After 120 minutes under these conditions, the tubular reactor containing the resulting polymer is cooled.

[0116] Next, the obtained copolyamide having the composition shown in Table 2 was pulverized into granules of several millimeters in size, and then, as described in Example 1, its characteristics with respect to its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were clarified. The results are summarized in Table 3 below.

[0117] Example B (Comparative Example) 23.35 g of hexamethylenediamine, 5.29 g of isophthalic acid, 16.71 g of adipic acid, 14.65 g of sodium salt of 5-sulfoisophthalic acid, 0.14 g of 8.5% phosphoric acid in water, 0.08 g of 60% sodium hypophosphite in water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over a nitrogen stream for 30 minutes. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. After 130 minutes under these conditions, the tubular reactor containing the resulting polymer is cooled.

[0118] Next, the obtained copolyamide having the composition shown in Table 2 was pulverized into granules of several millimeters in size, and then, as described in Example 1, its characteristics with respect to its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were clarified. The results are summarized in Table 3 below.

[0119] Example C (Comparative Example) 9.00 g of aminoundecanoic acid, 19.7 g of hexamethylenediamine, 13.24 g of isophthalic acid, 5.01 g of adipic acid, 5.72 g of sebacic acid, 7.33 g of sodium 5-sulfoisophthalic acid, 0.14 g of phosphoric acid in 8.5% water, 0.08 g of sodium hypophosphate in 60% water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over 30 minutes under a nitrogen stream. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. After 35 minutes under these conditions, the tubular reactor containing the resulting polymer is cooled with ambient air.

[0120] Next, the obtained copolyamide was pulverized into granules of several millimeters in size, and its characteristics with respect to its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were determined and evaluated as follows.

[0121] The obtained copolyamide having the composition shown in Table 2 was pulverized, and its characteristics with respect to glass transition temperature, water dispersibility, viscosity index, and viscosity were clarified as described in Example 1. The results are summarized in Table 3 below.

[0122] Example D (Comparative Example) 24.00 g of aminoundecanoic acid, 13.17 g of hexamethylenediamine, 12.36 g of isophthalic acid, 10.47 g of sodium 5-sulfoisophthalic acid, 0.14 g of 8.5% phosphoric acid in water, 0.08 g of 60% sodium hypophosphite in water, and 18 g of deionized water are placed in a tubular glass reactor equipped with a stirring anchor. After purging the reactor with nitrogen, the contents are heated to 145°C over a nitrogen stream for 30 minutes. These conditions are maintained for 30 minutes with stirring at 50 rpm, and then the temperature is gradually increased to 245°C over 20 minutes. The culture medium is then placed under a vacuum of 50 mbar. The progress of polymerization is monitored by a torque meter on the stirring shaft. After 140 minutes under these conditions, the tubular reactor containing the resulting polymer is cooled.

[0123] Next, the obtained copolyamide having the composition shown in Table 2 was pulverized into granules of several millimeters in size, and then, as described in Example 1, its characteristics with respect to its glass transition temperature, water dispersibility, melt viscosity index (MVI), and intrinsic viscosity were clarified. The results are summarized in Table 3 below. JPEG2026062700000002.jpg68170JPEG2026062700000003.jpg70170

[0124] A series of tests demonstrates that copolyamides having two polyamide units do not disperse in water, even when they contain a high content of sulfonate monomers (see Comparative Example A). Furthermore, migration to terpolyamide can improve water dispersibility, but this is not guaranteed and is not persistent in any case (see Examples B and D). Replacing short-chain units (PA66) with long-chain units (PA11) is also unsatisfactory (see Example D).

[0125] On the other hand, this study reveals that the copolyamides according to the present invention, which contain additional mainly aliphatic polyamide units and sufficient sulfonate monomer content, exhibit excellent water dispersibility in tap water at 70°C, even after 15 days of conditioning (Examples 1-3). Furthermore, these copolyamides have appropriate glass transition temperatures and appropriate melt viscosities, and are therefore excellent candidates as support materials for 3D printing.

[0126] [List of References, etc.] Brochure for International Patent Application Publication No. 2016 / 205690A1 Brochure for International Patent Application Publication No. 2011 / 147739A1 U.S. Patent No. 5889138 European Patent No. 0696607A1 French Patent No. 2172973 Specification

Claims

1. A water-dispersible copolyamide comprising at least four different polyamide units, - At least one of the polyamide units contains at least one sulfonate group, and the polyamide sulfonate unit is present in an amount of at least 15% by weight. - At least two of the polyamide units are derived from aliphatic monomers, The copolyamide is a water-dispersible copolyamide comprising not more than 20% by weight of caprolactam units, having a glass transition temperature between 100 and 140°C when measured by DSC according to standard NF EN ISO 11357-2 at a heating rate of 20°C / min, and having an intrinsic viscosity greater than 0.4 dl / g when measured at 20°C in a 0.5% by weight solution in m-cresol, according to standard ISO 307:2007.

2. A water-dispersible copolyamide according to claim 1, comprising at least five different polyamide units.

3. Copolyamide is given by formula (I): A / X １ Y １ / X ２ Y ２ / X ３ Y ３ / X ４ Z (I) During the ceremony, -A is a unit obtained from at least one lactam or aminocarboxylic acid containing at least six carbon atoms, -X １ Y １ is a unit obtained from an aliphatic, alicyclic, heterocyclic or arylaliphatic diamine X １ and an aliphatic or aromatic dicarboxylic acid Y １ and is -X ２ Y ２ This refers to aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X ２ , and aliphatic or aromatic dicarboxylic acid Y ２ It is a unit derived from, -X ３ Y ３ This refers to aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X ３ , and aliphatic or aromatic dicarboxylic acid Y ３ It is a unit derived from, -X ４ Z is an aliphatic, alicyclic, heterocyclic, or arylaliphatic diamine X containing 4 to 12 carbon atoms. ４ The formula SO contains 4 to 18 carbon atoms, and X may be hydrogen, a quaternary ammonium group, or a monovalent metal. ３ － X ＋ The water-dispersible copolyamide according to claim 2, which is a unit obtained from a sulfonate compound Z selected from aromatic dicarboxylic acid sulfonates, aliphatic sulfonates, or esters thereof having at least one group of the same group.

4. A copolyamide according to any one of claims 1 to 3, which does not contain more than 10% by weight of alicyclic diamine residue.

5. The water-dispersible copolyamide according to claim 3 or 4, wherein A is a lactam or an aminocarboxylic acid containing 10 to 12 carbon atoms, and is particularly selected from 11-aminoundecanoic acid and lauryl lactam.

6. X １ , X ２ , X ３ and X ４ A water-dispersible copolyamide according to any one of claims 3 to 5, wherein the two components are the same or different and selected from 1,2-ethylenediamine, 1,6-hexamethylenediamine, 1,9-nonanediamine, and 1,10-decanediamine.

7. Y １ and Y ２ A water-dispersible copolyamide according to any one of claims 3 to 6, wherein the two are the same or different and selected from adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid.

8. Y ３ A water-dispersible copolyamide according to any one of claims 3 to 7, wherein isophthalic acid.

9. The water-dispersible copolyamide according to any one of claims 1 to 8, wherein the sulfonate compound is selected from sodium, lithium, or potassium salts of 5-sulfoisophthalic acid and sodium, lithium, or potassium salts of methyl diester of 5-sulfoisophthalic acid.

10. Unit A represents 0-30% by weight, and unit X represents 0-30% by weight. １ Y １ , units X from 0 to 30% by weight ２ Y ２ , units X from 0 to 30% by weight ３ Y ３ , and units X from 15% to 70% by weight ４ A water-dispersible copolyamide according to any one of claims 3 to 9, comprising Z, wherein the copolyamide is understood to comprise at least four different polyamide units.

11. A water-dispersible copolyamide according to any one of claims 1 to 10, comprising at least 40% by weight of aromatic units.

12. A water-dispersible copolyamide according to any one of claims 1 to 11, having a glass transition temperature between 110 and 130°C.

13. A water-dispersible copolyamide according to any one of claims 1 to 12, having an intrinsic viscosity exceeding 0.5 dl / g, and particularly exceeding 0.6 dl / g.

14. a. A step of providing monomers selected from lactams, aminocarboxylic acids, and diamines and diacids in appropriate numbers and proportions. b. Where appropriate, a step of polycondensation of monomers in the presence of one or more catalysts and / or chain limiters under conditions suitable for obtaining the copolyamide, and c. The process of granulating the copolyamide, where appropriate. A method for producing a water-dispersible copolyamide according to any one of claims 1 to 13, comprising:

15. A composition comprising a water-dispersible copolyamide according to any one of claims 1 to 13, particularly in the form of a filament.

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