Use of modified polyamide for manufacturing Anti-bacterial textile products

Abstract

To provide economical, more effective and less polluting methods for manufacturing textile articles with anti-bacterial properties.SOLUTION: The invention provides the use of a polyetheramine in a polyamide containing nylon, in order to impart or increase anti-bacterial properties of the polyamide.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to the field of polymers. In particular, embodiments of the present invention relate to improvements in polymers for making threads, fibers, or synthetic yarns for producing textile products, such as woven, knitted, nonwoven fabrics, or other textile articles made from synthetic threads, fibers, or yarns. The embodiments described herein relate to improvements in polyamides. [Background technology]

[0002] In the manufacture of textile articles, in particular in the manufacture of clothing, there is an increasing demand to impart antimicrobial properties (ANTIMICROBIAL or ANTIBACTERIAL) to the threads, yarns or fibres used to manufacture the articles and to the clothing obtained from these semi-finished products. The need to impart antimicrobial or bacteriostatic properties to semi-finished products for the manufacture of textile articles is related to medical hygiene reasons and to the non-pathological side effects associated with the presence and proliferation of microorganisms in textile articles used in clothing. Medical hygiene reasons are related to the need to reduce the transmission of pathogens through textile articles, such as in hospital or industrial environments. Among the side effects associated with the presence and proliferation of microorganisms, especially in clothing, is the generation of microbial malodours.

[0003] Much research has been carried out with the aim of realising polymers suitable for knitting and weaving to be used for producing textile articles made of synthetic fibres, in particular with bactericidal properties. In general, the methods for imparting antibacterial or bacteriostatic properties to polymers can be subdivided into three categories: -Biocidal Polymers: They are polymers with intrinsic antimicrobial activity, usually based on the use of polycations that have the property of killing microorganisms through reactions on the cell membrane of the microorganisms. -POLYMERIC BIOCIDES: These are polymers with no intrinsic antimicrobial activity, to which the bactericidal molecules specifically bind. Polymeric bactericides are usually less effective than bactericidal polymers due to their characteristic steric hindrance, an effect known to occur due to the spatial distribution of atoms in a molecular structure that can cause a slowing or inhibition of a chemical reaction. The bactericidal molecules used in these cases are complex, have low thermal stability, are expensive, and are generally difficult to handle. - BIOCIDE-RELEASING POLYMERS: These are non-antimicrobial polymers with attached bactericidal molecules that are released over time. Essentially, they are polymer matrices carrying bactericidal molecules entrapped in the matrix in various ways. These polymers have many drawbacks due to the fact that the released bactericide is a contaminant or the bactericide in the polymer is lost over time and must be re-added.

[0004] An overview of recent developments in antimicrobial polymers is given in the following publications: Madson RE Santos et al., "Recent Developments in Antimicrobial Polymers: A review", in Materials, 2016, 9, 599; doi: 10.3390 / ma9070599 (www.mdpi.com / journal / materials); Xan Xue et al. Diana Santos Morais et al. "Antimicrobial Approaches for Textiles: From Research to Market", in Materials, 2016, 9, 498; doi: 10.3390 / ma9060498, (http: / / www.mdpi.com / j ournal / materials); Felix Siedenbiedel et al, "Antimicrobial Polymers in Solution and Surfaces: Overview and Functional Principles", in Polymers 2012, 4, 46-71; doi: 10.3390 / polym4010046 (www.mdpi.com / journal / polymers); Sheila Shahidi et al, "Antimicrobial Agents in Textile Industry", in "Antimicrobial Agents", edito da Varaprasad Bobbarala, ISBN 978-953-51-0723-1, September 12, 2012, chapter 19, pages 388-406

[0005] As is evident from the above mentioned scientific and technical literature, the production of polymers with antimicrobial properties gives rise to significant technical difficulties and / or drawbacks during their formation into fibres or when using the semi-finished products and the textile products obtained from these products. Thus, there is a continuing need for more effective, less polluting and economical solutions for producing textile articles with antimicrobial properties. More generally, there is a need for synthetic resins that have antibacterial or bacteriostatic properties, including antifungal properties. Summary of the Invention [Problem to be solved by the invention]

[0006] It has surprisingly been discovered, and is the object of the present invention, that certain modifications of polyamides, particularly polyamide 66 and polyamide 6, impart antibacterial and antifungal properties to the polymers. In this specification and claims, the term "antibacterial" generally refers to the ability to reduce or inhibit the growth of microorganisms, particularly bacteria, pathogens, molds and viruses (BACTERIA, MICROBES, FUNGI, VIRUSES).

[0007] More specifically, it has been found that polyamides containing nylon, particularly nylon 6 and nylon 66, acquire or improve antibacterial properties if polyetheramines are introduced into the polyamide molecule, and it has also been found that polyamides containing polyetheramine moieties attached to the nylon molecule have higher bacteriostatic activity than the same polyamide polyetheramine moieties.

[0008] WO2014 / 057364 and WO2015 / 001515 describe methods for producing modified polyamides containing nylon and polyether diamines that increase the moisture regain, i.e., the ability to absorb and retain moisture. In particular, it is suggested that these modified polyamides improve the feel of fabrics and clothing obtained from those fabrics. However, these prior art documents do not demonstrate the effect of polyether amines on the antibacterial properties of the modified polyamides.

[0009] According to one aspect, the present invention relates to the use of at least one polyetheramine in a polyamide containing nylon to enhance the antimicrobial properties of the polyamide, i.e. to obtain a modified polyamide having a higher antimicrobial activity than the same polyamide without the polyetheramine. Since the polyetheramine and the nylon are covalently linked and form part of the polyamide polymer chain, the antimicrobial properties imparted by the polyetheramine are stable and persistent over time, even when the polymer is subjected to repeated washing and / or heat treatments, which are typically encountered when using polyamides in the manufacture of textile articles, such as clothing.

[0010] The mechanism of the surprising effect achieved by the present invention is not entirely clear, however, without limiting the scope of this disclosure, it is believed that the amino groups present in the polyetheramines presumably inhibit the growth of microorganisms and impart bacteriostatic properties to the modified polyamides.

[0011] According to a further embodiment, the present invention relates to the use of polyamide fibers or yarns containing nylon and polyetheramines for the manufacture of textile articles having antimicrobial properties, including antifungal properties, particularly but not limited to clothing.

[0012] According to a more general embodiment, the present invention relates to the use of polyamides containing nylon and polyetheramines to manufacture articles having antimicrobial, including antifungal properties, in the textile industry as well as in any application where the antimicrobial properties of the modified resin are useful. The selection of the basic polymer or copolymer can be based on the intended end use of the modified resin.

[0013] Since the presence of bacteria in fabrics and garments leads to the generation of unpleasant odors, the uses and methods described herein for imparting or enhancing the antimicrobial activity of polyamides also indicate uses and methods for reducing or preventing the generation of unpleasant odors in garments made with fibers or threads containing said polyamides.

[0014] The invention also relates to the use of semi-finished products in the form of fibers or yarns containing nylon and polyamide containing polyetheramines in the manufacture of textile articles, such as clothing, which reduce or prevent the development of malodours.

[0015] Generally, the fibers or yarns may contain other materials in addition to nylon and polyamide containing polyetheramines, for example, may contain a percentage of polymers that do not contain polyetheramines. The fibers or yarns may be, for example, bicomponent fibers or yarns.

[0016] According to a further embodiment, the present invention relates to a method for producing polyamides containing nylon, in which a polyetheramine is introduced into the polymer structure of the polyamide to enhance the antimicrobial properties of the polyamide. The properties of the nylon and the polyetheramine are advantageously selected so that the polyamide can be extruded and converted into fibers or yarns for use in the manufacture of textile articles, particularly but not limited to clothing.

[0017] Also disclosed is a method for producing semi-fibrous products in the form of yarns or fibers containing polyamides containing nylon, in which polyetheramines are introduced into the polymer structure of the polyamide to enhance the antimicrobial properties of the polyamide.

[0018] Also disclosed is a method for producing semi-fibrous products in the form of yarns or fibers containing polyamides containing nylon, in which polyetheramines are introduced into the polymer structure of the polyamide to reduce the generation of unpleasant odors.

[0019] The method may include the step of adding a polyetheramine during the polymerization process. Accordingly, an object of the present invention includes the use of a polyetheramine in a polymerization process to form a nylon and a polyamide containing the polyetheramine, having improved antimicrobial properties.

[0020] In another embodiment, the method can provide a step of reacting the polyetheramine with the polyamide, which comprises contacting the polyetheramine with a polyamide containing nylon, to react the carboxyl end groups of the nylon with the amino groups of the polyetheramine molecule, thereby replacing the carboxyl end groups with polyetheramine moieties.

[0021] An object of the present invention is therefore the use of polyetheramines in a method for modifying polyamides, including nylon, also in order to introduce at least one polyetheramine into its chemical structure, i.e. into its polymer chain, to impart or enhance the antimicrobial capabilities of the modified polyamides containing the polyetheramines.

[0022] The present invention also relates to a method for producing a textile article, comprising converting a semi-finished product in the form of a fiber or yarn into a textile structure, such as a nonwoven, woven or knitted fabric. The semi-finished product comprises nylon and a polyamide containing polyetheramine to enhance the antimicrobial properties of the textile structure.

[0023] Preferably, the polyetheramine used in the polyamide has at least two amine end groups (NH2), one of which is used to bond the polyamide to the nylon molecule and the other of which remains available on the resulting polymer chain.

[0024] According to embodiments disclosed herein, the polyetheramine is preferably a polyetherdiamine or a polyethertriamine.

[0025] Preferably, the nylon is nylon 6 or nylon 66, or a copolymer of nylon 6 and nylon 66.

[0026] By using polyamides modified with polyetheramines, it is possible to obtain antibacterial properties of yarns and fibers by a process that can be easily implemented at an industrial level. In particular, in practice, the process conditions for introducing polyetheramines into the polyamide chain do not substantially differ from those used for the production of polyamides. Moreover, this has clear economic advantages compared to other currently known industrial processes aimed at achieving a similar effect.

[0027] In the various manufacturing processes, the amine groups can be attached at terminal positions on the polymer chain, although it is also possible for the amine groups to be at intermediate positions along the polymer chain.

[0028] The use of amino-modified nylon 6 and nylon 66 is particularly useful for the production of bacteriostatic or antibacterial textile articles. These products can be used not only in the clothing sector, but also in other sectors, such as, for example, the furniture sector, the automotive industry, or for the production of textile articles such as towels, sheets, gowns, etc. for home, hospital or general use.

[0029] Furthermore, the antibacterial or bacteriostatic properties imparted to polyamides modified by amino groups are also useful in fields other than the textile industry. Different modified polyamides with bacteriostatic and / or antibacterial properties may be used in fields where the synthetic resin must have different physical properties than those required for fibers or yarns. For example, in the dental field, resins are used to manufacture dental prostheses, dental instruments, dental splints, dental bites, etc. For these applications, it is necessary to impart special properties of mechanical strength and stiffness to the synthetic resin. The antibacterial properties of dental resins are particularly useful.

[0030] According to further embodiments, the present specification describes the use of polyamides modified with amino groups derived from polyetheramines that have antibacterial properties along with mechanical properties that make them useful in the dental field. In these applications, according to some embodiments, the base polyamide can include nylon 12 instead of nylon 6 or nylon 66.

[0031] Specifically disclosed is the use of nylon and polyamides containing polyetheramines for the manufacture of dental articles having bacteriostatic or antibacterial, including antifungal, properties, including dental splints, dental bites, dental prostheses and components thereof.

[0032] Features and embodiments of the present specification are disclosed as follows and further described in the claims, which form a binding part of this document. The above brief description sets forth the features of various embodiments of the present invention so that the detailed description that follows may be better understood and the present contribution to the art may be better appreciated. It is to be understood that other features of the present invention are described hereinafter and in the claims. In this regard, before describing several embodiments of the present invention in detail, it is to be understood that the various embodiments of the present invention are not limited in their application to the details of construction and the arrangement of elements illustrated in the following description and drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. It is also to be understood that the phraseology and terminology used herein is for the purpose of description and not of limitation. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a graph showing the antibacterial properties of fabrics made with polyamides consisting of nylon 66 and polyamides containing nylon 66 and polyetherdiamine, showing the results obtained according to ISO 20743:2013. [Diagram 2] 1 is a graph showing the antimicrobial properties of fabrics made with polyamides consisting of nylon 66 and polyamides containing nylon 66 and polyether diamine, showing results obtained according to ASTM E2315-03. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The following detailed description of the illustrated embodiments refers to the accompanying drawings. The same reference numbers in different drawings indicate the same or similar elements. Also, the drawings are not necessarily to scale. The following detailed description is not intended to limit the invention. Instead, the scope of the invention is defined by the claims.

[0035] Reference in the description to "one embodiment," "an embodiment," or "some embodiments" means that a particular feature, structure, or characteristic associated with an embodiment is included in at least one of the disclosed subject matter. Thus, the phrases "one embodiment," "an embodiment," and "some embodiments" in various places are not necessarily referring to the same embodiments. Moreover, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0036] Ratios, concentrations, amounts and other numerical values ​​depicted or mentioned in the present specification and claims can be expressed as ranges. It should be understood that this is used for convenience and precision, and that the ranges should not be understood to include only the numerical values ​​expressly set forth as the limits of the range. On the contrary, numerical ranges should be understood to be broad and flexible in the sense that they include all individual numerical values ​​contained in the range and all subranges bounded by two numerical values ​​contained in the range. Thus, in general, the expression "range from about A to about B" implies not only the range of the limited numerical values ​​A and B, but also any subrange from "about X to about Y" where X and Y are numerical values ​​contained between A and B.

[0037] If the content of substance A in substance B is defined by a series of maximum percentages and a series of minimum percentages, it should be understood that substance A is included in the group in an amount that is within a number of ranges defined by a combination of any one of the minimum values ​​and any one of the maximum values, respectively. For example, a definition containing at least x%, preferably at least (xn)%, and not more than y%, preferably not more than (ym)%, includes the ranges [x;y], [x;(ym)], [(xn);y], [(xn);(ym)]. Each of these ranges also includes each subrange defined between its maximum and minimum values.

[0038] The term "about" may include rounding a number to a significant figure. As used herein, the term "about" when referring to a numerical value or a range of numerical values ​​allows for a degree of variation of the numerical value or range, for example, within 10% of the stated numerical value or the stated limit of a range, or within 5% of the stated numerical value.

[0039] The term average molecular weight (Mw) as used herein, unless otherwise specified, should be understood as weight average molecular weight (commonly abbreviated as Mw).

[0040] According to embodiments described herein, polyetheramines attached to nylon molecules of polyamides are used to obtain polyamide-based polymers containing nylon for the manufacture of yarns or fibers that have improved antimicrobial capabilities or a reduced tendency to generate unpleasant odors when processed into garments and worn.

[0041] In general, the polyamide may be a dyeable acid (anionic) or base (cationic) polymer. In a particularly advantageous embodiment, the polyamide may comprise, for example, nylon 66 (polyhexamethylene adipamide). In another embodiment, the polyamide may comprise nylon 6, i.e., poly(ε-caprolactam). In a further embodiment, the polyamide may be a copolymer of nylon 6 and nylon 66.

[0042] The polyamide containing polyetheramine can be provided by a batch or continuous polymerization reaction, for example, by mixing a diacid, a nylon salt and a polyetheramine, and heating the mixture at a controlled pressure in one or more heating and cooling cycles to obtain the polymerization of the nylon and polyamide containing polyetheramine.

[0043] An example of a method for producing polyamides containing polyetheramines, in which the polyetheramines are introduced into the polyamide molecule during the polymerization process, is described in WO2014 / 057364, the contents of which are hereby incorporated by reference.

[0044] In other embodiments, the polyetheramine can be introduced into the polyamide chain after the polyamide has already been formed by a suitable polymerization process. For example, using a polyamide containing nylon and a polyetheramine, the polyamide and polyetheramine can be reacted in an extruder that feeds the spinning system, or in a separate vessel under controlled temperature and pressure, to replace the end groups of the polyamide molecules with polyetheramine molecules.

[0045] An example of a method for producing a polyamide containing nylon and a polyetheramine by reacting the polyamide and polyetheramine in an extruder or other pressurized vessel is described in WO2015 / 001515, the contents of which are hereby incorporated by reference.

[0046] Details regarding possible methods for producing polyamides containing nylon and polyetheramines by both batch and extrusion processes are provided below.

[0047] Although references herein are made specifically to examples in which a single polyetheramine (i.e., only one type of polyetheramine molecule) is used, it should be understood that in some embodiments, multiple polyetheramines having different formulae can also be incorporated into the polyamide chain.

[0048] In some embodiments, the polyetheramine can be a polyether monoamine having the following general formula (1):

[0049] [ka]

[0050] where R=H for ethylene oxide and R=CH3 for propylene oxide, where x and y vary depending on the number of propylene oxide and ethylene oxide present in the polymer chain. Polyether monoamines of formula (1) are commercially available, for example, as Jeffamine® M series (Huntsman, USA).

[0051] In a preferred embodiment, the polyetheramine has multiple free NH2 groups, and in the polymerization reaction, one of the NH2 groups forms a covalent bond with the nylon 66 or nylon 6 of the polyamide chain.

[0052] In some embodiments, the polyetheramine is a polyetherdiamine of the following general formula (2):

[0053] [ka]

[0054] where x, y and z may vary depending on the number of ethylene oxide and propylene oxide units in the polymer chain.

[0055] Polyetherdiamines of general formula (2) are commercially available, for example, as the Jeffamine (registered trademark) ED series and the Elastamine (registered trademark) RE series (both from Huntsman Chemical, USA).

[0056] In a preferred embodiment, the polyetheramine has an average molecular weight (Mw) of at least about 500, preferably at least about 800, more preferably at least about 1000, even more preferably at least about 1500, and preferably not more than about 5000, more preferably not more than about 3000, e.g., 1500-2500.

[0057] One embodiment provides for the use of Elastamine® RE-2000 (Huntsman) or Jeffamine® ED2003, both of which have the formula (1): y is approximately equal to 39 (x+z) is approximately equal to 6, and has an average molecular weight (Mw) of about 2000.

[0058] In another embodiment, polyetherdiamines of formula (2) can be used having the following characteristics: JPEG2025011090000003.jpg29170

[0059] Preferably, the polyetherdiamine has an AHEW (amine hydrogen equivalent) of 10% or less with respect to the ideal AHEW. The term "AHEW" is defined as the average molecular weight of the polyetheramine divided by the number of active amine hydrogens per molecule. For example, an ideal polyetheramine with an average molecular weight of 2000, all polyether end groups being amino terminated, and 4 active amino hydrogens per molecule would have an AHEW of 500g per equivalent. If 10% of the ends were hydroxyl groups instead of amino groups, and there were only 3.6 active amine hydrogens per molecule, the polyetheramine would have an AHEW of 556g per equivalent.

[0060] The number of active amine hydrogens per molecule, the AHEW of the resulting polyetheramine, can be calculated according to known and conventional techniques, for example, the nitrogen content of the amine groups is calculated using the procedure specified by the ISO 9702 standard.

[0061] In a particularly advantageous embodiment, the polyetheramine is a polyetherdiamine, preferably having a molecular weight of 1500 or more and an AHEW of no more than 10% of the ideal AHEW of the polyetherdiamine.

[0062] In the embodiments described herein, the polyether diamine has the general formula (2) and has a polymer chain composition that is rich in PEG (polyethylene glycol) groups relative to PPG (polypropylene glycol) groups, i.e., y>(x+z).

[0063] In another embodiment, the polyether diamine may contain polyethylene glycol (PEG) and polypropylene glycol (PPG) groups, with the polymer chain being rich in PPG groups. This type of polyether diamine is sold as the Elastamine® RP series (Huntsman).

[0064] In yet another embodiment, the polyether diamine can have a structure based on polypropylene glycol and poly(tetramethylene ether) glycol (PTMEG). Examples of this type of polyether diamine are the polyether diamines sold under the Elastamine® RT series (Huntsman).

[0065] Although the RE series polyetherdiamines having an average molecular weight of about 1500 or more and about 2500 or less are currently preferred, for applications to polyamides, particularly for the manufacture of fibers and yarns, polyetherdiamines having higher average molecular weights can be used, such as Elastamine® RP3-5000 (Huntsman) having an average molecular weight of about 5000 or less. In further embodiments, the polyetherdiamine can have, for example, a lower molecular weight (Mw).

[0066] In a further embodiment, the polyether diamine has a polymer chain comprised of polypropylene glycol (PPG) groups in the following general formula (3):

[0067] [ka]

[0068] For example, Jeffamine® D series polyether diamines manufactured and sold by Huntsman Corporation have average molecular weights (Mw) ranging from about 230 to about 4000, and x ranging from about 2.5 to about 68.

[0069] In a further embodiment, a polyetheramine can be used having a number of amino (NH2) terminal groups greater than 2. For example, the polyetheramine can be a polyethertriamine of the following general formula (4.1):

[0070] [ka]

[0071] wherein (x+y+z) is 5 to 6, and Mw is about 440. In other embodiments, the polyether triamine can be represented by the following general formula (4.2):

[0072] [ka]

[0073] Here, x+y+z is between about 50 and about 85, and the average molecular weight (Mw) is about 3000 to about 5000. Examples of this type of polyether triamine are the Jeffamine® T series manufactured and sold by Huntsman Corporation (USA).

[0074] The modified polyamides described herein can be produced by batch or continuous processes starting with nylon salt, diacid and polyetheramine. In some embodiments, the process provides for contacting the diacid, polyetheramine and nylon salt to form a mixture and heating the mixture in a closed vessel at a temperature and pressure sufficient to obtain polymerization of the mixture to form a polyamide containing nylon and polyetheramine. The nylon salt can be nylon 66 salt (hexamethylenediamine adipate), nylon 6 salt, or a combination thereof.

[0075] The nylon salts may be provided in a total weight range of about 50 to about 99 weight percent, preferably about 50 to about 95 weight percent.

[0076] Generally, the polymerization can include multiple subsequent heating cycles with appropriate pressure and temperature profiles. A more detailed description of possible polymerization cycles can be found in WO2014 / 057364. Depending on the type of nylon salt used, the final polymer can generally be a polyamide containing nylon 6, nylon 66, or a copolymer of nylon 6 and nylon 66, with polyetheramine molecules present in the polymer chain.

[0077] The final product can be formed into chips and used in a subsequent spinning process by extrusion methods according to known techniques.

[0078] In a further embodiment, as indicated above, polyetheramines can be introduced into the polyamide chain even after polymerization, for example by reacting the polyetheramine with the nylon-containing polyamide in an extruder or pressurized vessel. This type of method is described in WO2015 / 001515.

[0079] In some embodiments, the polyamide and polyetheramine are charged to a vessel, optionally with additives to facilitate the reaction of the polyamide with the polyetheramine. The polymer mass is brought to a melting temperature and reacted with the polyetheramine to obtain the modified polyamide.

[0080] The additive may include a chain extender or grafting agent for thermoplastic polymers, particularly polyamides, suitable for reacting with carboxyl and amino groups. In some embodiments, the additive may be the chain extender Joncryl® ADR-3400 sold by BASF. Other suitable additives may be Fusabond N493 from DuPont, Orgalloy R 6000-6600 from Athochem, and Irgarod RA20 from Ciba Specialty Chemicals.

[0081] After reaction of the polyamide with the polyetheramine, the resulting polymer can be directly extruded to obtain single or multifilament yarns for the formation of yarns or fibers for the manufacture of textiles, apparel or other articles.

[0082] In the embodiments described herein, the amount of polyetheramine in the polyamide can be between about 1% and about 50% by weight, such as about 2% to about 30% by weight, preferably about 5% to about 25% by weight, such as about 8% to about 20% by weight, based on the total weight of the polyamide.

[0083] In some embodiments, the polyamide comprises an amount of nylon of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, such as at least 85%, based on the total weight of the polyamide. In some embodiments, the proportion of nylon is 99% or less, preferably 98% or less, more preferably 95% or less, even more preferably 90% or less, such as 85% or less, based on the total weight of the polyamide.

[0084] As described herein, when the modified polyamide is used in a blend or combination with other polymers, such as, for example, a bicomponent fiber, the above percentages of nylon and polyetheramine refer to the total weight of the polyamide, including nylon and polyetheramine, excluding the weight of the second component polymer or additional polymers attached thereto.

[0085] Usable polyamides can have a molecular mass of, for example, about 8,000 to about 18,000 UMA. In some embodiments, the polyamide has a molecular mass of about 9,000 to about 15,000 UMA, for example, about 10,000 to about 14,000 UMA.

[0086] In a possible embodiment, the polyamide can have a number of amino end groups (NH2) equal to the number of carboxyl end groups (COOH), for example 47 each.

[0087] The polyamides described herein can be advantageously used in the form of continuous yarns or staple fibers to manufacture semi-finished products for the textile industry. The yarns can be single or multifilament yarns.

[0088] The yarns are obtained by extrusion and the staple fibers are obtained by chopping the extruded continuous yarns. The yarns obtained from the extrusion of the polymer according to the method described herein may be multifilament fiber yarns of the LOY (low oriented yarn), POY (partially oriented yarn) or FDY (fully oriented yarn) type.

[0089] When the yarns are chopped into fibers, the fibers may have a length of, for example, between about 10 and about 100 mm. The staple fibers can be converted into continuous yarns by known spinning processes.

[0090] According to another embodiment, staple fibers are used to make nonwoven fabrics or to form fiber plies, which are subsequently subjected to mechanical, hydraulic, chemical, thermal bonding processes, or combinations thereof.

[0091] The yarn may be used for weaving processes, knitting processes, or other uses.

[0092] The yarns produced by the processes described herein can be treated to modify their physical and mechanical properties. In some embodiments, the yarns can be combined with other yarns to obtain composite products. In some embodiments, the yarns coming out of the spinneret can be textured or taslanted, stretched, combined with elastic yarns, for example by interlace jets or cover jets or other suitable devices.

[0093] A yarn or fiber can be monocomponent. In this case, the filaments are composed of the same material. In other embodiments, the yarn may be multicomponent, for example bicomponent. One or more filaments forming the yarn in this case comprise two portions formed by two different polymers. In some embodiments, the filaments comprise an inner core and an outer coating made of different polymers (so-called "core-skin" bicomponent fibers). According to possible embodiments, the outer portion or skin surrounding the inner core can be composed of a high moisture regain polymer containing polyamide and polyetheramine, while the core can be composed of a different polymer, for example a polyamide that does not contain polyetheramine molecules. In some embodiments, a nylon 6 or nylon 66 core can be extruded with a skin of polyamide and polyetheramine produced according to the present invention.

[0094] In some embodiments, the bicomponent fibers may have a second component comprised of or containing polypropylene or a thermoplastic polyurethane or polyester, such as polyethylene terephthalate or polybutylene terephthalate.

[0095] In other embodiments, the two components forming each filament can be arranged side-by-side with one another (so-called "side-by-side" bicomponent fibers) rather than being inserted one inside the other.

[0096] Extrusion heads for producing multicomponent fibers, particularly bicomponent fibers, are known and may be used to advantage in the context described herein.

[0097] In some embodiments, the bicomponent yarn may be made with 10% to 95% by weight, preferably 50% to 80% by weight, of the constituent polymers containing polyamide and polyetheramine, while the remaining portion is comprised of unmodified polyamide (i.e., polyamide without polyetheramine) or only nylon or other types of polymers, such as polypropylene.

[0098] In some embodiments, the yarn is extruded with a filament count between 1 and 300, such as between 5 and 200.

[0099] In some embodiments, the yarn has a yarn count between about 5 and about 6000 dtex. In an advantageous embodiment, the yarn has a DPF value (dtex per filament) between 0.5 and 20.

[0100] In particular, in some embodiments, the yarn has a number of filaments, including between 1 (single filament) and about 100, preferably between about 30 and about 60, and a number of filaments, including between about 7 and about 140 dtex, preferably between about 40 and about 60 dtex. In some embodiments, the polymer is extruded at an extrusion speed of between 20 and 80 cm / sec. The filaments exiting the spinneret can be advantageously cooled by known methods, such as, for example, air flow.

[0101] In this process, the individual filaments are cooled by a transverse air flow and then combined to form a multifilament yarn by converging and passing through an oil feed. Downstream, the yarn can be fed to one or more drawing and / or relaxation and / or stabilization rollers. The rollers are electrically controlled at different peripheral speeds to impart the required or desired degree of drawing and / or orientation to the yarn.

[0102] In some embodiments, the yarn is subjected to an elongation of between 20% and 60%.

[0103] Finally, the yarn is wound to form a reel or package. Winding speeds can include, for example, between about 1000 and about 5500 m / min. EXAMPLES

[0104] (Antibacterial Test) Comparative tests were carried out on the antibacterial activity of polyamides containing polyetheramines, as described below.

[0105] The fabric samples were knitted on a circular knitting machine using a polyamide 66 multifilament yarn with a count of 46 dtex and 40 filaments, and the fabric samples were knitted using a polyamide 66 multifilament yarn (count 46 dtex, 40 filaments) modified with polyetherdiamine Elastamine® RE2000 (Huntsman) in a weight equal to 8% by weight with respect to the total weight of the yarn.

[0106] Fabric samples were inoculated with the following bacteria according to the ISO 20743:2013 standard: -Gram-positive bacteria, Staphilococcus aureus (DSM 346) - Gram-negative bacteria, Klebsiella pneumoniae (DSM 789) In addition, the following bacteria were inoculated according to the ASTM E2315-03 standard: -Gram-positive bacteria, Staphilococcus aureus (DSM 346) - Gram-negative bacteria, Escherichia coli (DSM 1576)

[0107] Figure 1 shows the results obtained according to ISO 20743:2013 and Figure 2 shows the results obtained according to ASTM E2315-03. The number of bacteria (10 ) detected in nylon 66 and modified polyamide containing the polyetherdiamine Elastamine® RE2000 (Huntsman) in a weight amount equal to 8% by weight relative to the total weight of nylon 66 and yarn. 6 As can be seen from Figure 1, the fabric samples made of modified polyamide containing polyetherdiamine have antibacterial properties according to the ISO test. - 40% antibacterial activity with respect to Staphylococcus aureus, i.e. 40% lower bacterial growth than that obtained with a reference fabric made of the same polyamide but without polyetheramine - 4% antibacterial activity with respect to Klebsiella pneumoniae, i.e. 4% lower bacterial growth than that obtained with a reference fabric made of the same polyamide but without polyetheramine

[0108] According to the ASTM test in Figure 2, the fabric samples made of modified polyamide containing polyetherdiamine have antibacterial properties. - 50% antibacterial activity with respect to Staphylococcus aureus, i.e. 50% lower bacterial growth than that obtained with a reference fabric made of the same polyamide but without polyetheramines - 30% antibacterial activity with respect to E. coli, i.e. 30% lower bacterial growth than that obtained with a reference fabric made of the same polyamide but without polyetheramine

[0109] The data shown in both figures were obtained 24 hours after inoculation with the bacteria. In each figure, two bar graphs for each bacteria are shown in the figure. The bar on the left relates to a reference sample (reference fabric) made with standard polyamide (nylon 66), while the bar on the right relates to a sample made with modified polyamide containing polyetheramine.

[0110] It is important to note that the international test standards used are used only to establish the procedures to be followed to carry out the tests. They do not provide any absolute or relative comparison criteria to define whether the detection activity is weak, good or excellent. This parameter must be established based on the characteristics of the final product with which it must ultimately be compared (e.g. the odor emanating from a fabric, etc.).

[0111] According to the above data, it can be said that fabrics made with fibers chemically modified by the introduction of polyetheramines are characterized by a reduction in bacterial growth in the fabric compared to the same fabric made with a standard fiber (nylon 66). The antibacterial activity was confirmed in two different types of tests (ISO and ASTM). In fact, in the compared polyamide-based fabrics, activities of 40% and 50% were measured with respect to Staphylococcus aureus, which are comparable. It must be mentioned that Klebsiella pneumoniae is a particularly resistant bacteria and difficult to kill. Thus, a clearly lower activity was obtained than that obtained with respect to other bacterial strains.

[0112] Finally, not all bacterial colonies are equal in terms of their ability to produce unpleasant odors. A particularly relevant test for this indicator is the E. coli test.

[0113] The tests carried out show that the introduction of polyetheramine molecules into the nylon chains allows a substantial improvement of the polymer with regard to its antibacterial activity.

[0114] The increased antimicrobial activity resulting from the modification of polyamides by the insertion of polyetheramines into the polymer chains allows the formation of polymerized filamentary materials, i.e. suitable for forming multifilament or monofilament yarns, which can be converted into staple fibers that can be advantageously used in the manufacture of textile articles, by converting the fibers or yarns into fabrics or nonwovens. These textile articles can be advantageously used in the clothing sector, in particular in sportswear, due to their ability to reduce the generation of malodours due to bacterial growth. The antimicrobial activity actually results in a reduction in the growth of microorganisms that are responsible for the generation of malodours. Furthermore, the modified polymers are also advantageously used when a reduction in the bacterial load is required for health and hygiene reasons, i.e. when a reduction in the amount of bacteria is required. For example, textile materials using modified polyamides with improved antimicrobial properties as described herein can be used in coats, pajamas, sheets, drapes, protective masks, pillowcases, blankets, curtains, bandages and others, in particular for use in hospitals.

[0115] For example, polyamides containing nylon and polyetheramines with or without antimicrobial activity can be used in all applications where polyamides are commonly used in the medical field. For example, polyetheramines are used to impart antimicrobial properties to polyamides for the manufacture of medical yarns and membranes, such as suture yarns, balloon membranes for angioplasty catheters (also in the form of nylon 11 or nylon 12), bandages, medical membranes, hemodialysis membranes, tendon and ligament reconstruction materials, etc. The modified polyamides described herein, such as modified polyamide 12 (nylon 12), can be used in particular for the manufacture of dental articles, particularly dental splints, dental bites, dental appliances, dentures, fixed or movable dental prostheses, and some of their components.

Claims

1. 2. Use of polyetheramines in polyamides, including nylon, to impart or enhance antimicrobial properties to the polyamide.

2. 2. The use according to claim 1, wherein the polyetheramine is a polyetherdiamine or a polyethertriamine.

3. 3. The use according to claim 1 or 2, wherein the nylon is selected from the group consisting of nylon 6; nylon 66; nylon 12; a copolymer containing at least two components selected from nylon 6, nylon 66, nylon 12, or a combination thereof.

4. The polyetheramine reacts with the free amino groups (NH ２ 4. The use according to claim 1 , wherein the aryl group is predominantly located as a chain end having a chain terminus with a cyclic alkyl group.

5. 5. Use according to any one of claims 1 to 4, wherein the weight percentage of polyetheramine is at least about 1%, preferably at least about 5%, more preferably at least about 10%, relative to the total weight of the polyamide, and the weight percentage of polyetheramine is not more than about 50%, preferably not more than about 30%, more preferably not more than about 25%, even more preferably not more than about 20%, relative to the total weight of the polyamide.

6. 6. Use according to any one of claims 1 to 5, wherein the polyamide comprises a weight percentage of nylon of at least about 50%, preferably at least about 60%, more preferably at least about 70%, even more preferably at least about 80%, for example at least about 85%, based on the total weight of the polyamide, and the weight percentage of nylon is not more than about 99%, preferably not more than about 95%, more preferably not more than about 90%, based on the total weight of the polyamide.

7. 7. Use according to any one of claims 1 to 6, wherein the polyetheramine has an average molecular weight (Mw) of at least about 500, preferably at least about 800, more preferably at least about 1000, even more preferably at least about 1500, preferably not more than about 5000, more preferably not more than about 3000.

8. 8. Use according to any one of claims 1 to 7 for the manufacture of semi-finished products for the manufacture of textile articles, said semi-finished products being selected from the group consisting of staple fibres; continuous monofilament yarns; continuous multifilament yarns.

9. 9. The use according to claim 8, wherein the semi-finished product is a two-component semi-finished product.

10. 11. Use according to claim 9 or 10, wherein the bicomponent semi-finished product comprises a weight percentage of polyamide of at least about 10%, preferably at least about 50%, preferably not more than about 95%, more preferably not more than about 80%, relative to the total weight of the semi-finished product.

11. 1. Use of a polyamide yarn or fiber comprising nylon and at least one polyetheramine for the manufacture of a textile article having antibacterial properties.

12. 12. The use according to claim 11, wherein the textile article is selected from the group comprising: nonwoven fabrics composed of bonded fibers; woven fabrics; knitted fabrics; or combinations thereof.

13. 13. The use according to claim 11 or 12, wherein the polyetheramine is a polyetherdiamine or a polyethertriamine.

14. 14. The use according to any one of claims 11 to 13, wherein the nylon is nylon 6, nylon 66, or a copolymer of nylon 6 and nylon 66.

15. The polyetheramine reacts with the free amino groups (NH ２ 15. The use according to any one of claims 11 to 14, wherein the aryl group is predominantly located as a chain end having a chain end with a cyclic alkyl group.

16. 16. Use according to any one of claims 11 to 15, wherein the weight percentage of polyetheramine is at least about 1%, preferably at least about 5%, more preferably at least about 10%, relative to the total weight of the polyamide, and the weight percentage of polyetheramine is not more than about 50%, preferably not more than about 30%, more preferably not more than about 25%, even more preferably not more than about 20%, relative to the total weight of the polyamide.

17. 17. Use according to any one of claims 11 to 16, wherein the polyamide comprises a weight percentage of nylon of at least about 50%, preferably at least about 60%, more preferably at least about 70%, even more preferably at least about 80%, for example at least about 85%, based on the total weight of the polyamide, and the weight percentage of nylon is not more than about 99%, preferably not more than about 95%, more preferably not more than about 90%, based on the total weight of the polyamide.

18. 18. Use according to any one of claims 11 to 17, wherein the polyetheramine has an average molecular weight (Mw) of at least about 500, preferably at least about 800, more preferably at least about 1000, even more preferably at least about 1500, and preferably has an average molecular weight (Mw) of not more than about 5000, more preferably not more than about 3000.

19. 19. The use according to any one of claims 11 to 18, wherein the fibre or yarn has a bicomponent structure, one of the components being nylon and the polyamide containing polyetheramine.

20. 20. The use of claim 19, wherein the bicomponent fiber or yarn comprises a weight percent of nylon and polyamide containing polyetheramine that is at least about 10%, preferably at least about 50%, based on the total weight of the bicomponent fiber or yarn, and preferably not more than about 95%, more preferably not more than about 80%, based on the total weight of the bicomponent fiber or yarn.

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