Modified polyester having antibacterial properties and use of the modified polyester

Abstract

To provide polymers with antibacterial properties and also to provide methods for producing textile articles with antibacterial properties in a more financially advantageous, more effective and less polluting manner.SOLUTION: Provided is a polyester having antibacterial properties, containing polyethylene terephthalate and containing at least a polyether amine.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the field of polymers. In particular, aspects disclosed herein relate to improvements in polymers for producing synthetic threads, fibers and yarns, for example for producing woven, nonwoven or other textile articles. Further aspects relate to improvements in polymers for producing articles for medical applications.

[0002] SUMMARY OF THE DISCLOSURE Embodiments disclosed herein relate to improvements in polyesters, particularly polyethylene terephthalate (hereinafter PET), and new applications for these polymers. [Background technology]

[0003] In the manufacture of textile articles, such as in the clothing, furniture, automotive and also medical and healthcare sectors, there is an increasing demand to impart antimicrobial properties to the threads, yarns or fibres used to manufacture the manufactured articles and to the products 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 on the one hand to health and hygiene and on the other hand to non-pathological side effects related to the presence and proliferation of microorganisms in textile articles used in clothing or other applications where contact with the skin is required. Health and hygiene reasons relate to the need to reduce the transmission of pathogens through textile articles, such as in industrial or hospital environments. It is recognized that the side effects related to the presence and proliferation of microorganisms, especially in clothing, are responsible for the generation of malodours.

[0004] Much research has been carried out with the aim of producing polymers for the manufacture of textile articles, in particular made of synthetic fibers or threads, with bactericidal properties. In general, the methods for imparting antibacterial or bacteriostatic activity to polymers fall into three macro categories: -Biochemical polymers: These are polymers with intrinsic antimicrobial activity that are based on the use of polycations to kill microorganisms, usually via their movement on the cell membrane of the microorganism. -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. Steric hindrance is characterized as an effect that can cause a slowing or inhibition of a chemical reaction due to the spatial distribution of atoms in a molecular structure. The molecules with bactericidal properties used in these cases are complex, relatively temperature unstable, expensive, and generally difficult to handle. - BIOCIDE-RELEASING POLYMERS: These are polymers that have no antimicrobial activity themselves, but have bactericidal molecules attached to them that are released over time. Essentially, they are polymer matrices that carry bactericidal molecules trapped in the matrix in various ways. These polymers have many drawbacks, such as the fact that the released bactericide is a contaminant or that the bactericide carried by the polymer is lost over time and must be reloaded.

[0005] An overview of recent developments in antimicrobial polymers is given in the following references: 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, ( www.mdpi.com / journal / 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", published by Varaprasad Bobbarala, ISBN 978-953-51-0723-1, September 12, 2012, chapter 19, pages 388-406

[0006] The need to use textile articles with antibacterial properties in the medical and hospital sector arises from the fact that these products can be dangerous vehicles for the spread of microorganisms. The risks arising from bacterial contamination of textile articles used in the medical and hospital sector are discussed in the following publications: A. Pinon et al., "Microbiological Contamination of Bed Linen and Staff Uniforms in a Hospital", in Advances in Microbiology, 2013, 3, 515-519, published online on http: / / www.scirp.org / journal / aim; http: / / dx.doi.org / 10.4236 / aim.2013.37069 S. Fijan et al., "Hospital Textiles, Are They a Possible Vehicle for Healthcare- Associated Infections?", in Int. J. Environ. Res. Public Health 2012, 9, 3330-3343; doi: 10.3390 / ijerph9093330, published in www.mdpi.com / journal / ijerph

[0007] As described in the above mentioned scientific and technical documents, the production of polymers with antimicrobial properties gives rise to significant technical difficulties and / or drawbacks during their conversion into fibers or during the use of semi-finished products and textile articles obtainable therefrom. Moreover, the above mentioned documents indicate an increasing need for polymers with bactericidal properties, especially in the clothing and medical fields. For this reason, solutions are continually being sought for more economically advantageous, more effective and less polluting production of textile articles with antimicrobial properties.

[0008] In addition to their use in the manufacture of textile fibers and threads and related products made therewith, polymeric materials have many applications in the medical field where antimicrobial properties would be beneficial. A summary of the use of polymeric materials in the medical and surgical fields is given in the following references: VP Shastri, "Non-Degradable Biocompatible Polymers in Medicine: Past, Present and Future", in Current Pharmaceutical Biotechnology, 2003, 4, 331-337; W. Khan et al. "Implantable Medical Devices", in Focal Controlled Drug Delivery, chap.2, by AJDomb and W.Khan; Advances in Delivery Science and Technology, DOI 10.1007 / 978-1-4614-9434-8_2, available on http: / / www.springer.com / gp / book / 9781461494331 ; LW McKeen, "Plastics Used in Medical Devices", in "Handbook of Polymer Applications in Medicine and Medical Devices. DOI: http: / / dx.doi.org / 10.1016 / B978-0-323-22805-3.00003.7, 2014 published by Elsevier Inc. (https: / / www.elsevier.com / _data / assets / pdf_file / 0011 / 91649 / Plastics-Used-in-Medical-Devices_link.pdf); MF Maitz, "Applications of synthetic Polymers in Clinical Medicine", in Biosurface and Biotribology 1 (2015) 161-176, available online at www.Sciencedirect.com. Polymers with antimicrobial properties would be beneficial in the medical and surgical fields. Summary of the Invention [Problem to be solved by the invention]

[0009] It has now surprisingly been discovered that antimicrobial properties can be imparted to polyesters by modifying the polyethylene terephthalate chains with at least one polyetheramine. The modified polyesters obtained by functionalization with polyetheramines exhibited the ability to reduce the growth of bacterial colonies inoculated onto samples of the polymer, i.e., bactericidal activity, compared to comparable polyethylene terephthalates not containing polyetheramines.

[0010] Thus, one aspect of the present invention relates to polyesters containing polyethylene terephthalate and at least one polyetheramine, in particular as polymers with improved antimicrobial activity, and the modified polyesters are functionalized polyesters containing polyethylene terephthalate chains which contain one or more polyetheramine moieties.

[0011] Although the embodiments shown herein use a single polyetheramine in combination with polyethylene terephthalate, it is also possible to use multiple polyetheramines, e.g., in combination with various numbers of amino groups (polyetherdiamines, polyethermonoamines, polyethertriamines, etc.), while end-functionalizing the polyethylene terephthalate chain by introducing polyetheramine moieties.

[0012] In this disclosure and claims, unless otherwise specified, antimicrobial activity or antibacterial properties generally refers to the ability to reduce or prevent the growth of microorganisms, particularly bacteria, pathogens, molds, and viruses. Thus, antimicrobial activity can include antimold or antifungal activity.

[0013] It is known to use polyetheramines as molecules for functionalization of polymers. WO2014 / 057364 and WO2015 / 001515 describe a method for producing modified polyamides, including nylon and polyetherdiamines, which 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 the clothes obtained from them. However, these documents are related to different types of polymers and suggest the use of polyetheramines for other purposes.

[0014] The introduction of at least a polyetheramine into the polyethylene terephthalate chain increases the antibacterial properties of the polyester, i.e. makes it possible to obtain modified polyesters with greater antibacterial power when compared to the same polyesters without polyetheramine. The polyetheramine and the polyethylene terephthalate are covalently bonded to each other in the polymeric chain of the polyester. The antibacterial properties thus provided by the polyetheramine are stable and persistent, even when the polyester is subjected to chemical, thermal or mechanical actions such as washing, sterilization processes, for example when extruding the polyester to wash or sterilize textile articles such as fabrics, nonwovens, etc. obtained from the modified polyester threads and fibers, during the manufacture of threads, filaments, fibers or semi-finished products.

[0015] The mechanism by which the surprising effects underlying the various embodiments described herein are obtained is not entirely clear. It is presumed that the amino groups present in the polyetheramines prevent the growth of microorganisms and impart bacteriostatic properties to the modified polyethylene terephthalate, but this should not be understood as limiting the scope of the present invention.

[0016] Preferably, the polyetheramines are prevalently located as chain ends having free amino ends (NH2) in the polyethylene terephthalate. The polyether amine may be a polyether monoamine. In a currently preferred embodiment, the polyetheramine contains more than one amino group and so can be, for example, a polyetherdiamine or a polyethertriamine.

[0017] The polyetheramine may be present in a weight percentage of at least about 1% by weight, preferably at least about 2% by weight, more preferably at least about 5% by weight, based on the total weight of the polyester. In the embodiments described herein, the polyetheramine may be present in an amount of about 50% by weight or less, preferably about 30% by weight or less, more preferably about 25% by weight or less, even more preferably about 20% by weight or less, based on the total weight of the polyester. For example, the polyester may contain polyetheramine in a weight percentage percentage of about 1% to about 50%, preferably about 1% to about 25%. In some embodiments, the polyester may contain polyetheramine in a percentage of about 1% to about 20%, about 2% to about 20%, or about 2.5% to about 15%.

[0018] In some embodiments, the polyester can comprise at least about 50% by weight, preferably at least about 60% by weight, more preferably at least about 70% by weight, and even more preferably at least about 80% by weight, of polyethylene terephthalate based on the total weight of the polyester. In the embodiments described herein, the weight percentage of polyethylene terephthalate is about 99% by weight or less, preferably about 98% by weight or less, and even more preferably about 95% by weight or less based on the total weight of the polyester, for example, the polyester can comprise about 50% by weight to about 99% by weight, preferably about 75% by weight to about 99% by weight, for example, about 80% by weight to about 99% by weight, or about 80% by weight to about 98% by weight, or about 85% by weight to about 97.5% by weight, of polyethylene terephthalate.

[0019] In some embodiments, the weight average molecular weight (Mw) of the polyetheramine is at least about 500 g / mol, preferably at least about 800 g / mol, more preferably at least 1000 g / mol, even more preferably at least about 1500 g / mol, and preferably not more than about 5000 g / mol, more preferably not more than about 3000 g / mol, for example, from 1500 to 2800 g / mol.

[0020] The polyetheramine modified polyesters disclosed herein may be particularly useful for the manufacture of textile articles. Textile products herein refer to both semi-finished and finished products. Semi-finished products may refer to continuous monofilament or multifilament threads, staple fibers, or yarns obtained by spinning staple fibers. Semi-finished products also refer to fabrics, tapes or tubular woven fabrics, or knitted fabrics, multi-ply nonwoven fabrics, consisting of bonded or unbonded fibers, threads or filaments, bonded, for example, mechanically, thermally, chemically, hydraulically, or by any method or combination of two or more of the aforementioned bonding methods. Semi-finished products or textile articles may include multi-ply products consisting of two or more combined plies of textile fibers or threads.

[0021] The textile may be composed only of polyethylene terephthalate and polyester containing at least one polyetheramine, as described above. In some embodiments, the textile may contain one or more additional components in addition to the polyester containing PET and polyetheramine. In some exemplary embodiments, different types of polymers may be combined with the polyester containing PET and polyetheramine. For example, embodiments of the subject matter described herein may be composed of filaments or fibers of two or more components, one of which is composed of a polyester containing PET and polyetheramine, and the other of which is composed of a different type of polymer, such as polyamide, polyethylene terephthalate without polyetheramine.

[0022] The bicomponent fibers or filaments may, for example, be comprised of at least about 40% by weight, preferably at least about 50% by weight, and more preferably at least about 60% by weight, of polyester containing polyethylene terephthalate and polyetheramine, based on the total weight of the textile.

[0023] The threads, filaments, fibers or yarns made with the modified polyester containing polyethylene terephthalate and polyetheramine described herein can be used as such or mixed with other natural, artificial or synthetic threads, filaments, fibers or yarns, including those made with polyesters that do not contain polyetheramine or other polymers such as polyamides or other suitable components. In this case, the polyester containing polyethylene terephthalate and polyetheramine can be present in the textile product in a weight percentage of at least about 10%, preferably at least about 50%, more preferably equal to about 60% or 70%, by weight. It is also preferred that this percentage is not more than about 95%, more preferably not more than about 80%, by weight of the total weight of the textile product.

[0024] According to a further aspect, the present specification discloses that polyesters containing polyethylene terephthalate and at least a polyetheramine are used to manufacture products or articles having antimicrobial properties.

[0025] In particular, it is disclosed herein that polyesters containing polyethylene terephthalate and at least a polyetheramine are used to manufacture textile articles having antimicrobial properties, and that the textile articles are selected from nonwoven, woven, knitted fabrics, with or without bonded fibers, or combinations thereof. According to a further aspect, the present specification discloses a method for imparting antimicrobial properties to polyesters containing polyethylene terephthalate by introducing a polyetheramine into the polyethylene terephthalate chain during or subsequent to the polymerization process, thereby reacting the polyetheramine with the already polymerized polyester.

[0026] According to a further aspect, the present specification discloses a method for making polyesters, particularly modified polyesters having antimicrobial properties, comprising reacting terephthalic acid, ethylene glycol, and a polyetheramine at a temperature and pressure sufficient to cause polymerization and formation of a polyester, particularly a polyester containing polyethylene terephthalate and a polyetheramine.

[0027] In some embodiments, a method for producing a polyester containing polyethylene terephthalate and a polyetheramine includes the steps of: reacting terephthalic acid and ethylene glycol with an excess of ethylene glycol to obtain polyethylene terephthalate having terminal carboxyl groups; The method includes reacting the terminal carboxyl groups with a polyetheramine to obtain a polyester containing polyethylene terephthalate and polymer chains containing polyetheramine.

[0028] According to another embodiment, a method for modifying already polymerized polyester to introduce at least a polyetheramine into the polyethylene terephthalate chain is provided. The method may include a step of reacting polyethylene terephthalate and a polyetheramine to obtain a polyester having antimicrobial properties and containing polyethylene terephthalate and a polyetheramine. The method may be carried out in an extruder to produce continuous monofilament or multifilament threads composed of modified polyethylene terephthalate having improved antimicrobial properties and containing polyetheramine, where the polyester containing polyethylene terephthalate, for example in chip or granular form, is added as a starting material directly to the extruder or in a vessel separate from the extruder or in fluid communication therewith, and a suitable amount of at least a polyetheramine is added. The polyester is reacted with the polyetheramine and the modified polyester is extruded to form a semi-finished article for use as a thread, fiber article, etc.

[0029] In other embodiments, the resulting modified polyester can be reprocessed into semi-finished products in the form of chips, granules, etc., for subsequent conversion steps. In other words, if the functionalization reaction of polyester and polyetheramine is initiated from already polymerized polyester and not from starting monomers, the modified polyester can be used to produce semi-finished products in any physical form suitable for subsequent processes, including further melting and extrusion steps. The stability of the covalent bond between polyetheramine and polyethylene terephthalate ensures that the antimicrobial properties obtained by introducing polyetheramine into the polyethylene terephthalate chain are maintained, even when the polymer is subjected to subsequent thermal treatment and mechanical processing operations. To facilitate the reaction of the already polymerized polyethylene terephthalate and polyetheramine, some embodiments may include the step of adding a grafting agent or chain extender. The method may include the steps of adding a grafting agent or chain extender to the polyethylene terephthalate and reacting the functionalized polyethylene terephthalate with a polyetheramine to obtain a functionalized polyethylene terephthalate.

[0030] According to a further aspect, the present invention relates to the use of polyester fibers or threads containing polyethylene terephthalate and at least a polyetheramine for the manufacture of textile articles having antimicrobial properties, such as fabrics, sheets, blankets, curtains, gauzes, or medical or surgical devices.

[0031] The antibacterial properties obtained by modifying polyethylene terephthalate with polyetheramines make the modified polyesters particularly suitable for all applications in which antibacterial properties are desirable and useful, for example in the medical and surgical field, but also in the clothing sector, where the reduction in bacterial load reduces the generation of malodours due to sweat.

[0032] The present specification also discloses a method for producing a textile article, comprising converting a semi-finished product in the form of textile fibers or threads into a textile structure, such as one or more plies of a nonwoven, woven, or knitted fabric, the semi-finished product comprising polyethylene terephthalate and a polyetheramine, to enhance the antimicrobial properties of the textile structure.

[0033] In some embodiments, the polyetheramine has at least two amino groups (NH), one of which is used to react with the polyethylene terephthalate to form a covalent bond with the polyester chain and one of which remains available on the resulting polymer chain.

[0034] The features and embodiments of the present specification are disclosed as follows, and the essentials of the specification are further described in the claims. The above brief description presents the features of various embodiments of the present invention so that the detailed description below may be better understood and the contributions of the present invention to the art may be better appreciated. Other features of the present invention are described in the remainder of the specification and 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 present invention is capable of other embodiments and can be practiced in various ways. Also, the phraseology and terminology used herein is for the purpose of description and not of limitation.

[0035] It is believed that those skilled in the art may readily utilize the conception on which this disclosure is based as a basis for designing other structures, methods, and / or systems for carrying out the various purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

[0036] The use of modified polyesters with polyetheramines as described herein allows textile threads and fibers, as well as other semi-finished or finished products, to have antibacterial properties through a process that can be easily implemented on an industrial scale.In fact, the process conditions, particularly for the introduction of polyetheramines into the polyethylene terephthalate chain, do not change significantly from those used to produce conventional, normal polyethylene terephthalate, i.e., polyethylene terephthalate that does not contain polyetheramines.Furthermore, this approach has the obvious advantage of being low cost compared to other currently known industrial processes for obtaining a similar effect in terms of increased antibacterial properties. [Brief description of the drawings]

[0037] The invention will now be described with reference to a series of exemplary embodiments and the results obtained, which are illustrated in the accompanying drawings, in which: Figure 1 shows the antimicrobial activity of a fabric containing conventional PET threads and a fabric containing threads made of polyetherdiamine-containing PET, i.e. PET functionalized with polyetheramine according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] 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. Rather, the scope of the invention is defined by the claims.

[0039] References in the description to "an embodiment," "an embodiment," or "some embodiments" refer to particular features, structures, or elements associated with at least one embodiment of the subject matter. Thus, the phrases "an embodiment," "an embodiment," or "some embodiments" in various instances of the description do not necessarily refer to the same embodiments. Moreover, particular features, structures, or elements may be combined in any suitable manner in one or more embodiments.

[0040] Ratios, concentrations, amounts and other numerical data shown or mentioned in the specification and claims can be expressed in the form of a range. It should be understood that this form of expression is used for convenience and conciseness, and the range should not be understood to include only the numerical data explicitly stated as the limit of the range. Instead, the range of numerical values ​​should be understood to be broad and flexible in the sense that it includes all individual numerical values ​​included in the range and all subranges separated by two numerical values ​​included in the range. Thus, in general, the expression "range from about A to about B" means not only the range from the ends of A and B, but also any subrange from "about X to about Y" where the numerical values ​​between A and B are X and Y.

[0041] When the contents of substance A and substance B are defined as a series of maximum percentages and a series of minimum percentages, it should be understood that the amount of substance A that can be contained in substance B falls 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 including 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 upper and lower limits.

[0042] 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.

[0043] According to embodiments described herein, polyetheramines attached to one or more monomers of polyethylene terephthalate in the polyester chain are used to obtain polyester-based polymers, including polyethylene terephthalate (PET), with improved antimicrobial activity.

[0044] Polyesters containing polyethylene terephthalate and polyetheramines can be obtained by a batch or continuous polymerization reaction using monomers for producing polyethylene terephthalate (terephthalic acid and ethylene glycol) as starting materials and adding at least a polyetheramine.

[0045] Examples of polyetheramines, particularly polyetherdiamines and polyethertriamines, that may be used in the processes and final products described herein are set forth below.

[0046] In some embodiments, the method provides for reacting terephthalic acid and ethylene glycol with an excess of ethylene glycol to obtain polyethylene terephthalate having terminal carboxyl groups.

[0047] [ka]

[0048] The reaction is carried out with an acid catalyst at a temperature of about 150°C to about 200°C under a pressure of about 4 bar. The resulting PET is reacted with polyether diamine to obtain modified polyethylene terephthalate having NH2 terminal groups. That is, the reaction is as follows:

[0049] [ka]

[0050] where H2N-R-NH2 is a typical polyether diamine, examples of which are described later in this specification. The reaction can be carried out at a temperature of about 120°C to about 140°C for 24 hours at atmospheric pressure.

[0051] The resulting modified polyethylene terephthalate can be in granular, chip or other suitable form and can be used in subsequent manufacturing processes such as molding, injection, co-molding, extrusion, blowing, etc.

[0052] In particular, the polyesters thus obtained containing polyethylene terephthalate and polyetheramine can be melted and extruded to obtain monofilament or multifilament threads that are semi-finished products for subsequent textile articles, the continuous filaments can be chopped into fibers and used to make nonwoven fabrics, or spun to obtain continuous yarns.

[0053] In another embodiment, modified polyesters can be produced starting from already polymerized polyethylene terephthalate, e.g., in chip, granular, etc. form, which undergoes a functionalization reaction. In the functionalization reaction, a polyetheramine molecule reacts with the end group of a polyethylene terephthalate molecule, or with two consecutive monomers of a PET molecule. The following reaction takes place between the chain end group of polyethylene terephthalate and a common polyetherdiamine H2N-R-H2 to obtain a modified polyester with the production of ethanol:

[0054] [ka]

[0055] Conversely, if a polyetheramine molecule reacts within the chain of two monomeric polyethylene terephthalate, the following reaction is obtained:

[0056] [ka]

[0057] In order to facilitate the formation of a polymer chain containing modified polyethylene terephthalate by adding polyetheramine to already polymerized polyethylene terephthalate as a starting material, a chain extender or grafting agent can be used to facilitate the formation of bonds between polyetheramine molecules and polyethylene terephthalate monomers. In some embodiments, formaldehyde and bromoacetic acid can be used as chain extenders. In the first step, pre-polymerized polyethylene terephthalate can react with the chain extender to form a carboxyl functionalized polyethylene terephthalate based on the reaction. The reaction is as follows:

[0058] [ka]

[0059] The first reaction can be carried out in 1 M acetic acid at about 30° C. for about 4 hours, and the second reaction can be carried out in 2 M sodium hydroxide at 30° C. for 18 hours.

[0060] The resulting molecule can react with each COOH end group via an amidation reaction with polyetheramine, resulting in a polyester containing polyetheramine as shown in the following reaction:

[0061] [ka]

[0062] In the formula, H2N-R-NH2 represents a common polyetherdiamine, examples of which are shown below. m is the number of PET, the number of PET monomers in a molecule containing n PET monomers, that reacts with the polyetheramine. The reaction can be carried out at about 120-140°C for 24 hours at atmospheric pressure. The value is The parameter n can be comprised between about 10 and about 1000. The parameter m can be between 1 and 100. The reaction may be carried out in a batch process.

[0063] In another embodiment, polyethylene terephthalate can be functionalized with polyetheramines in a continuous process in which polyethylene terephthalate is reacted with polyetheramines under suitable temperature and pressure conditions to obtain a functionalization reaction in a short time period, adapted to the residence time of the reagents in a constant feed volume based on said reaction, in the presence or absence of a grafting agent or chain extender.

[0064] For example, the polyester and the polyetheramine are fed to the extruder at the same or different positions in the longitudinal direction of the extruder, i.e. in the direction of the auger or other material feed system along the extruder. For example, the polyethylene terephthalate can be fed to the vessel at the upstream of the longitudinal direction of a single or twin screw filling auger. The polyetheramine can be introduced downstream of the polyethylene terephthalate feed point relative to the auger's filling direction, and contacts the polyethylene terephthalate that has been previously melted at the upstream of the path defined by the filling auger. At the downstream of the polyetheramine feed point, the latter reacts with the polyethylene terephthalate to obtain a polyester functionalized with polyetheramine, which is linearly extruded.

[0065] If the reaction is carried out with the use of one or more reaction aids, such as the grafting agents or chain extenders described above, these may be introduced along with the polyethylene terephthalate or afterwards, for example between the polyethylene terephthalate and polyetheramine feed points, along with the polyetheramine, or downstream of the polyetheramine feed point.

[0066] A molten mass of polyethylene terephthalate that has been reacted, or is being reacted, with a polyetheramine can be extruded to produce threads or filaments, or other semi-finished products of indefinite length.

[0067] In another embodiment, the polyethylene and polyetheramine can be reacted in the extruder with a residence time of 200 to 800 seconds, for example about 300 to about 700 seconds, preferably about 450 to about 600 seconds, typically about 550 seconds, with functionalization during the extrusion process. The residence temperature can be, for example, between about 250°C and about 350°C, preferably between about 270°C and about 310°C, for example, in particular about 290°C. The pressure in the extruder can be, for example, between about 100 bar and about 300 bar, preferably between about 100 bar and about 250 bar. The polymer mass of polyethylene terephthalate functionalized with polyetheramine can be extruded at a total flow rate of between 10 and 20 kg / h, preferably between 12 and 18 kg / h, for example about 15 kg / h. Exemplary embodiments defined by the specific parameters of the monofilament or multifilament thread are described below.

[0068] The starting polyethylene terephthalate has a weight average molecular weight (Mw) between about 10,000 and about 40,000, and in some embodiments, the relative viscosity (measured by a 1% solution in dichloroacetic acid) can be between about 0.4 and 1.0 dl / g. In some embodiments, the PET can contain 2% or less, preferably 1.5% or less, by weight, of TiO2. Examples of polyethylene terephthalates useful for making the modified polyesters described herein, particularly for textile applications, are RT20 manufactured and sold by INVISTA Resins & Fibers GmbH & Co Kg (Germany) and SM-01 / D535 sold by Novapet (Spain).

[0069] In other embodiments, polyether monoamines or polyether triamines can be used in place of the polyether diamines, as exemplified in the previous reaction.

[0070] If the polyester functionalized with polyetheramine is intended for the production of a continuous thread, for example for use in textile articles, a functionalization process in which polyether terephthalate reacts directly with polyetheramine, in the presence or absence of a grafting agent or chain extender, will be particularly interesting.In this case, indeed, polyethylene terephthalate and polyetheramine in chip form can be used as starting materials for an extrusion and spinning process in which the two components (PET and polyetheramine) come into contact with each other at the outlet of which is located a spinneret, from which a continuous thread is delivered, such as in an extruder or in a high-pressure chamber in fluid communication with the extruder.

[0071] In another embodiment, the modified polymer obtained by the reaction of PET with polyetheramine can be converted again into chips, granules or other shapes other than threads and then used in conversion processes such as molding and extrusion.

[0072] Details of polyetheramines that can be used in the process for producing polyethylene terephthalate and polyesters containing polyetheramines using any of the above methods are provided below.

[0073] Although references herein are made specifically to examples using a single polyetheramine (i.e., only one type of polyetheramine molecule), it should be understood that in some embodiments, multiple polyetheramines having different formulae can be incorporated into the polymer chain of polyethylene terephthalate.

[0074] In some embodiments, the polyether amine can be a polyether monoamine having the following general formula (1):

[0075] [ka]

[0076] 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 chain. Polyether monoamines of formula (1) are available, for example, from Jeffamine® M series (Huntsman, USA).

[0077] In a preferred embodiment, the polyetheramine has multiple free NH2 groups, and upon reaction with polyethylene terephthalate, one of the NH2 groups forms a covalent bond with the polyethylene terephthalate polymer chain, while the remaining NH2 group remains available.

[0078] In some embodiments, the polyetheramine is a polyetherdiamine of the following general formula (2):

[0079] [ka]

[0080] where x, y and z can vary depending on the number of ethylene oxide and propylene oxide groups present in the polymer chain.

[0081] As the polyether diamine of general formula (2), for example, Jeffamine (registered trademark) ED series and Elastamine (registered trademark) RE series (both manufactured by Huntsman Chemical, USA) can be used.

[0082] In a preferred embodiment, the polyetherdiamine has a weight average molecular weight (Mw) of at least about 500 g / mol, preferably at least about 800 g / mol, more preferably at least about 1000 g / mol, even more preferably at least about 1500 g / mol, and preferably not more than about 5000 g / mol, more preferably not more than about 3000 g / mol, e.g., 1500 to 2500 g / mol.

[0083] One embodiment provides for the use of Elastamine® RE-2000 (Huntsman) or Jeffamine® ED2003, either of formula (1): y is approximately equal to 39 (x+z) is approximately equal to 6, and has a weight average molecular weight (Mw) of about 2000 g / mol.

[0084] In another embodiment, polyetherdiamines of formula (2) can be used having the following characteristics: JPEG2025041609000010.jpg24154

[0085] 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 weight average molecular weight of the polyetheramine divided by the number of active amine hydrogens per molecule. For example, an ideal polyetheramine with a weight average molecular weight of 2000 g / mol, all polyether ends being amines, and 4 active amine hydrogens per molecule would have an AHEW of 500 g per equivalent. If 10% of the ends were hydroxyl groups instead of amines, and there were only 3.6 active amine hydrogens per molecule, the polyetheramine would have an AHEW of 556 g per equivalent.

[0086] The number of active amine hydrogens per molecule, the AHEW of the resulting polyetheramine, can be calculated according to the prior art and conventional techniques, for example, the nitrogen content of the amine groups is calculated using the procedure specified by the ISO 9702 standard.

[0087] In a particularly advantageous embodiment, the polyetheramine is a polyetherdiamine, preferably having a weight average molecular weight of 1500 g / mol and an AHEW not exceeding 10% of the ideal AHEW of the polyetheramine.

[0088] 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).

[0089] In another embodiment, the polyether diamine can have a polymer chain that contains polyethylene glycol (PEG) and polypropylene glycol (PPG) groups, with the PPG groups predominating. Polyether diamines of this type are available in the Elastamine® RP series (Huntsman).

[0090] In yet another embodiment, the polyether diamine can have the basic structure of polypropylene glycol and poly(tetramethylene ether glycol) (PTMEG). Examples of this type of polyether diamine are the polyether diamines sold in the Elastamine® RT series (Huntsman).

[0091] Although RE series polyetherdiamines having a weight average molecular weight of about 1500 g / mol or more and about 2500 g / mol or less are currently preferred, it is also possible to use polyetherdiamines having higher weight average molecular weights, for example polyetherdiamines having a weight average molecular weight of 5000 g / mol or less, such as Elastamine® RP3-5000 (Huntsman), particularly for applications with polyesters for the manufacture of fibers and threads. In other embodiments, the polyetherdiamines can have a weight average molecular weight (Mw) of less than 1500 g / mol, for example, 1000 g / mol or less, or 800 g / mol or less.

[0092] In another embodiment, the polyether diamine has a polymer chain comprised of a polypropylene glycol PPG group in the following general formula (3):

[0093] [ka]

[0094] Examples of this type of polyetherdiamine are the Jeffamine® D series of polyetherdiamines manufactured and sold by Huntsman Corporation, where the weight average molecular weight (Mw) varies from about 230 g / mol to about 4000 g / mol and x varies from about 2.5 to about 68.

[0095] In yet another embodiment, a polyetheramine can be used having a number of amino groups (NH2) greater than 2. For example, the polyetheramine can be a polyethertriamine of the following general formula (4.1):

[0096] [ka]

[0097] Wherein (x+y+z) can be between 5 and 6, and the weight average molecular weight Mw can be equal to about 440 g / mol. In other embodiments, the polyether triamine can be represented by the following general formula (4.2):

[0098] [ka]

[0099] where x+y+z is between about 50 and about 85, and the weight average molecular weight (Mw) is from about 3000 g / mol to about 5000 g / mol. Examples of polyether triamines of this type are the Jeffamine® T series manufactured and sold by Huntsman Corporation (USA).

[0100] In some embodiments, the amount of polyetheramine in the polyester can be between about 1 and about 50 weight percent, such as between about 2 and about 30 weight percent, preferably between about 2 and about 25 weight percent, such as between about 2.5 and about 20 weight percent, or between about 5% and about 20 weight percent, based on the total weight of the polyester.

[0101] In some embodiments, the polyester comprises at least about 50% by weight, preferably at least about 60% by weight, more preferably at least about 70% by weight, even more preferably at least about 80% by weight, such as at least 85% by weight, of polyethylene terephthalate based on the total weight of the polyester. In some embodiments, the proportion of polyethylene terephthalate is about 99% by weight or less, preferably about 98% by weight or less, such as about 95% by weight or less, or about 90% by weight or less, or about 85% by weight or less, based on the total weight of the polyester.

[0102] When the modified polyester containing polyetheramine is used in blends or combinations with other polymers, such as in bicomponent fibers or blends with fibers, threads or filaments composed of other polymers, the percentages of polyethylene terephthalate and polyetheramine given above refer to the total weight of the polyethylene terephthalate and the polyester containing polyetheramine, excluding the weight of the second or additional polymer in the blend.

[0103] Usable polyesters can have, for example, a molar mass between about 1,000 and about 1,000,0000 g / mol. In some embodiments, the polyesters have a molar mass between about 2,000 and about 1,000,0000 g / mol.

[0104] The polyesters described herein can be advantageously used to manufacture semi-finished textile products in the form of continuous threads or in the form of staple fibers. The threads can be monofilament or multifilament.

[0105] The threads are obtained by extrusion and the staple fibers are obtained by chopping the extruded continuous threads. The threads obtained from the extrusion of the polymer according to the method described herein can be multifilament textile threads of the LOY (low oriented yarn), POY (semi-oriented yarn) or FDY (fully oriented yarn) type.

[0106] When the threads are chopped into fibers, the fibers can have lengths of, for example, between about 2 and about 200 mm, preferably between about 10 and about 100 mm. The staple fibers can be converted into continuous yarns using known spinning processes.

[0107] 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.

[0108] The threads or yarns may be used for weaving processes, knitting processes, or other applications.

[0109] The threads produced by the processes described herein can be treated to modify their physical and mechanical properties. In some embodiments, the threads can be combined with other threads to obtain composite articles. In some embodiments, the threads obtained from the spinneret can be textured or taslanted, stretched, combined with elastic threads, for example by interlacing or cover jets or other suitable devices.

[0110] A thread or fiber can be monocomponent, in which case the one or more, or each, filament that forms it is composed of a single material.

[0111] In other embodiments, the thread can be multicomponent, for example bicomponent. The filament or filaments forming the thread 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 ("core-skin" bicomponent fibers). According to a possible embodiment, the outer portion or skin surrounding the inner core can be composed of a polyester containing polyethylene and polyetheramine, while the core can be composed of a different polymer.

[0112] In some embodiments, the bicomponent fibers can have a second component such as polyamide, polypropylene, or a thermoplastic polyurethane or polyester, such as polyethylene terephthalate or polybutylene terephthalate that does not contain polyetheramines.

[0113] In other embodiments, the two components forming each filament can be side-by-side with one another (a "side-by-side" bicomponent fiber) rather than being inserted one inside the other.

[0114] Extrusion heads for producing threads made of multiple components, in particular two components, are known and can be used to advantage in the context of the method described herein.

[0115] In some embodiments, the bicomponent threads comprise 10-95% by weight, preferably 50-80% by weight, of the polymers that make up the threads are polyesters containing polyethylene terephthalate and polyetheramines, while the remaining portions are polyamides, unmodified polyesters (i.e., containing no polyetheramines), or other types of polymers (e.g., polypropylene).

[0116] Depending on the intended application, the threads can have a filament count between 1 (monofilament) and 10,000. In some embodiments, they can have a count between about 5 and about 6000 dtex, preferably between about 5 and about 5000 dtex, for example between about 5 and about 3000 dtex.

[0117] In some embodiments, the thread is extruded with a filament count between 1 and 300, such as between 5 and 200.

[0118] In an advantageous embodiment, the thread may have a DPF value (dtex per filament) between 0.3 and 20, for example between 0.4 and 20.

[0119] In some embodiments, particularly for use in, for example, fabric manufacturing, the filament count of threads can be between 1 (monofilament) and about 100, preferably between about 30 and about 80, and in some embodiments, between about 40 and about 75. Also, the count can be between about 7 and about 140 dtex, preferably between about 40 and about 120 dtex, for example between about 50 and about 100 dtex, and in some embodiments, can have a count of about 90 dtex.

[0120] In some embodiments, the polymer is extruded at an extrusion speed between 20 and 80 cm / sec. The filaments exiting the spinneret can be advantageously cooled by known methods, such as, for example, air flow.

[0121] In this process, the single filaments are cooled by a transverse air flow and converge through an oil feed where they are combined to form a multifilament thread. Downstream the thread is fed to one or more drawing and / or relaxation and / or stabilization rollers, which are electrically controlled at different peripheral speeds to impart the required or desired degree of drawing and / or orientation.

[0122] The threads can be stretched and / or textured at an elongation percentage between about 15% and 200%. In some embodiments, the threads are stretched to between 20% and 150%.

[0123] Finally, the thread is wound to form a reel or package at a winding speed of between about 1000 and about 5500 m / min, preferably between about 2000 and about 3500 m / min, for example, between about 2500 and about 3000 m / min, and in one embodiment, about 2800 m / min. EXAMPLES

[0124] (Antibacterial Test) A comparative test of the antimicrobial activity of polyethylene terephthalate and polyester containing polyetheramine was carried out as described below.

[0125] The following were produced: a fabric sample knitted on a circular knitting machine with a multifilament thread made of polyethylene terephthalate with a tip of polyester RT20 (Invista Resins & Fibers GmbH&Co KG, Germany) with a count of 50 dtex with 52 filaments, 70 dtex with 60 filaments, 90 dtex and 92 filaments, and a fabric sample knitted on a circular knitting machine with the same multifilament thread with the above count and filament number, but with a polyester containing polyethylene terephthalate (RT20 Invista) and polyether diamine (Elastamine® RE2000 (Huntsman) at 2.5% by weight relative to the total thread weight. The polyethylene terephthalate functionalized with Elastamine® RE2000 was obtained by reaction in an extruder as described above.

[0126] Two fabric samples (with and without polyetheramines in the polyethylene terephthalate polymer chain) were inoculated with the following bacteria according to standard ASTM E2315-03: -Gram-positive bacteria, Staphilococcus aureus (DSM 346) - Gram-negative bacteria, Klebsiella pneumoniae (DSM 789)

[0127] Figure 1 shows the results obtained. The number of bacteria (10 10 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 500 510 520 530 540 550 560 610 620 630 640 650 700 7 6 As can be seen from FIG. 1, the fabric samples made of modified polyester obtained by functionalizing polyethylene terephthalate with polyether diamine obtained the following antibacterial activities: - 30% antibacterial activity with respect to Staphylococcus aureus, i.e. 30% lower bacterial growth than that obtained with a reference fabric made of the same polyamide but without polyetheramine - 18% antibacterial activity with regard to Klebsiella pneumoniae, i.e. 18% lower bacterial growth than that obtained with a reference fabric made of the same polyamide but without polyetheramine

[0128] The data shown were obtained 24 hours after inoculation with the bacteria. Two bar graphs for each bacteria are shown in the figure. The bar on the left relates to a standard polyethylene terephthalate reference sample (reference fabric), while the bar on the right relates to a sample of polyester containing polyethylene terephthalate and polyether diamine.

[0129] It is important to note that the international standard tests used are used only to establish the procedures to be followed to perform 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 final properties of the product to which it must ultimately be compared (e.g. odor emanating from a fabric, etc.).

[0130] According to the above data it can be said that fabrics made with fibers chemically modified by the incorporation of polyetheramines show a reduction in bacterial growth in the fabric compared to the same fabrics made with the standard fibers. It should be noted that Klebsiella pneumoniae is particularly resistant and difficult to kill, so it is not surprising that lower activity values ​​are obtained for Klebsiella pneumoniae than for other bacterial strains.

[0131] The tests carried out show that the introduction of polyetheramine moieties into the polymer chain of polyethylene terephthalate makes it possible to achieve a significant improvement of the polymer in terms of its antibacterial activity.

[0132] (Examples of manufacturing process and use) The examples given below explain the invention in more detail.

[0133] Example 1 (Preparation of PET Yarns with Elastamine RE2000 in Reactive Extrusion) The procedure given below describes the preparation of yarns of PET (polyethylene terephthalate) functionalized with a polyether diamine called Elastamine RE2000 (Huntsman, USA).

[0134] (Procedure for producing yarn) PET is injected at a flow rate of 5 kg / h into the extruder operating at 290° C. The flow rate of Elastamine RE2000 is 0.26 kg / h with a residence time of 10 minutes (the proportion of Elastamine RE2000 is equal to 5% by weight relative to the total weight of the polymer).

[0135] To evaluate the effectiveness of the functionalization reaction of the yarn obtained by the above method, chemical and physical analyses were carried out according to the following experimental procedures.

[0136] In particular, after washing with sodium dodecyl sulfate at a concentration (w / v) of 5% in water at 40, 60 and 80°C, a conversion rate equal to 100% for the functionalization reaction was confirmed. Carbon nuclear magnetic resonance also showed the presence of Elastamine RE2000 in the yarn. Typical signals of PET can be found in the following spectrum: δ 167.6 (C=OR), 133.1 (C Ar), 129.3 (C Ar), 63.0 (CH2). The characteristic peak of Elastamine RE2000 is present at 69.15 ppm.

[0137] The yarns were subjected to bacterial culture testing according to ISO 20743 and ASTM 2315-03. Two bacterial strains were used: Gram-positive bacteria, Staphilococcus aureus (DSM 346) Gram-negative bacteria, Klebsiella pneumoniae (DSM 789) The test was carried out as follows: The functionalized PET fabric was chopped into 0.04 g ± 0.05 pieces. The number of samples used was 6, and the number of samples of non-functionalized PET was 6. The specimens were placed in a multi-well plate and disinfected with a 70% ethanol (volume / volume) aqueous solution for 30 min. Bacterial growth was then assessed according to ISO 20743 and ASTM 2315-03. The polyetheramine functionalized PET samples showed bacterial growth equal to 5% relative to the untreated PET samples (100%) for both gram-positive and gram-negative bacteria.

[0138] The antifungal activity was evaluated according to the ISO 13629-2:2014 standard using Aspergillus aculeatus ATCC 36411 as the fungal strain. PET samples functionalized with polyetheramines gave a fungal growth rate equal to 2% relative to untreated PET (100%). In this and subsequent examples, a value of 100% is attributable to microbial growth in non-functionalized PET, and the bacterial growth potential of treated PET samples is expressed as a percentage of untreated PET. Thus, a percentage of 5% mold or bacterial growth means that the microbial growth of the tested sample is equal to 5% of the microbial growth of an untreated (i.e., not functionalized with polyetheramine) reference sample.

[0139] In a modified embodiment, it is possible to add one or more grafting agents or chain extenders during the reaction step in the extruder.

[0140] Example 2 (Preparation of PET Yarns with Elastamine RP3-5000 in Reactive Extrusion) The procedure given below describes the preparation of PET (polyethylene terephthalate) yarns functionalized with Elastamine RP3-5000 (Huntsman, USA), a trifunctional primary amine with a molecular weight (Mw) equal to about 5000, characterized by oxypropylene repeat units.

[0141] (Procedure for producing yarn) PET is injected at a flow rate of 5 kg / h into the extruder operating at 290° C. The flow rate of RP3-5000 is 0.26 kg / h with a residence time of 10 min (the proportion of RP3-5000 is equal to 5% by weight relative to the total weight of the polymer).

[0142] To evaluate the effectiveness of the functionalization reaction of the yarn obtained by the above method, chemical and physical analyses were carried out according to the following experimental procedures.

[0143] In particular, after washing with sodium dodecyl sulfate at a concentration (weight / volume) of 5% in water at 40, 60 and 80°C, a conversion rate equal to 98% to the functionalization reaction was confirmed. Carbon nuclear magnetic resonance also showed the presence of RP3-5000 in the yarn. Typical signals of PET can be found in the following spectrum: δ 167.6 (C=OR), 133.1 (C Ar), 129.3 (C Ar), 63.0 (CH2). The characteristic peak of RP3-5000 is present at 69.15 ppm.

[0144] The yarns were subjected to bacterial culture testing according to ISO 20743 and ASTM 2315-03. Two bacterial strains were used: Gram-positive bacteria, Staphilococcus aureus (DSM 346) Gram-negative bacteria, Klebsiella pneumoniae (DSM 789) The test was carried out as follows: The PET fabric functionalized with RP3-5000 was chopped to 0.04 g ± 0.05. The number of specimens used was 6, whereas the number of specimens of non-functionalized PET was 6. The specimens were placed in a multi-well plate and disinfected with a 70% ethanol (volume / volume) aqueous solution for 30 min. Bacterial growth was then assessed according to ISO 20743 and ASTM 2315-03. The samples prepared using functionalized PET showed bacterial growth potential equal to 40% relative to untreated PET samples (100%) for both Gram-positive and Gram-negative bacteria.

[0145] The antifungal activity was evaluated according to the ISO 13629-2:2014 standard using Aspergillus aculeatus ATCC 36411 as the fungal strain. PET samples functionalized with polyetheramines showed a mold growth rate equal to 1% relative to untreated PET (100%).

[0146] Example 3 (Preparation of PET Yarns Using Jeffamine M2005 in Reactive Extrusion) The procedure given below describes the preparation of PET (polyethylene terephthalate) yarns functionalized with Jeffamine M2005 (Huntsman, USA), a monoamine with a molecular weight (Mw) of approximately 2000.

[0147] (Procedure for producing yarn) PET is injected at a flow rate of 5 kg / h into the extruder operating at 290° C. The flow rate of Jeffamine M2005 is 0.26 kg / h with a residence time of 10 minutes (the proportion of Jeffamine M2005 is equal to 5% by weight relative to the total weight of the polymer).

[0148] To evaluate the effectiveness of the functionalization reaction of the yarn obtained by the above method, chemical and physical analyses were carried out according to the following experimental procedures.

[0149] In particular, after washing with sodium dodecyl sulfate equal to 5% concentration (w / v) in water at 40, 60 and 80 °C, a conversion rate equal to 97% for the functionalization reaction was confirmed. Carbon nuclear magnetic resonance also showed the presence of JA in the yarn. Typical signals of PET can be found in the following spectrum: δ 167.6 (C=OR), 133.1 (C Ar), 129.3 (C Ar), 63.0 (CH2). The characteristic peak of Jeffamine M2005 is present at 69.15 ppm.

[0150] The yarns were subjected to bacterial culture testing according to ISO 20743 and ASTM 2315-03. Two bacterial strains were used: Gram-positive bacteria, Staphilococcus aureus (DSM 346) Gram-negative bacteria, Klebsiella pneumoniae (DSM 789) The test was carried out as follows: The PET fabric functionalized with Jeffamine M2005 was chopped into 0.04 g ± 0.05 pieces. The number of specimens used was 6, while the number of specimens of non-functionalized PET was 6. The specimens were placed in a multi-well plate and disinfected with a 70% ethanol (volume / volume) aqueous solution for 30 min. Bacterial growth was then assessed according to ISO 20743 and ASTM 2315-03. The samples prepared using functionalized PET showed bacterial growth potential equal to 55% relative to untreated PET samples (100%) for both Gram-positive and Gram-negative bacteria.

[0151] The antifungal activity was evaluated according to the ISO 13629-2:2014 standard using Aspergillus aculeatus ATCC 36411 as the fungal strain. Specimens functionalized with Jeffamine M2005 showed a mold growth rate equal to 1% relative to untreated PET (100%).

[0152] Example 4 (Preparation of PET yarn using Elastamine RE2000) The procedure given below describes the preparation of PET (polyethylene terephthalate) yarn functionalized with Elastamine RE2000 (Huntsman, USA) via direct esterification and condensation polymerization reactions.

[0153] (Procedure for producing yarn) Ethylene glycol and terephthalic acid are provided to an autoclave capable of reflux or distillation. The set conditions are a pressure between 2.7 and 5.5 bar and a temperature between 220 and 260°C. The water generated by the condensation polymerization is removed by distillation. The esterification step may be two-stage, the set conditions for the second stage being 250-270°C and atmospheric pressure. The monomer obtained above is placed in a polymerization reactor, which is operated at 10-40 mmHg and 250-300°C, and Elastamine RE2000 is continuously added dropwise to the reactor so that the amount of Elastamine RE2000 becomes 5% by weight based on the total weight of the polymer. The above obtained dry polymer is fed into an extruder to obtain PET yarn functionalized with Elastamine RE2000.

[0154] To evaluate the effectiveness of the functionalization reaction of the yarn obtained by the above method, chemical and physical analyses were carried out according to the following experimental procedures.

[0155] In particular, after washing with sodium dodecyl sulfate at a concentration (w / v) of 5% in water at 40, 60 and 80 °C, a conversion rate equal to 100% for the functionalization reaction was confirmed. Carbon nuclear magnetic resonance also showed the presence of JA in the yarn. Typical signals of PET can be found in the following spectrum: δ 167.6 (C=OR), 133.1 (C Ar), 129.3 (C Ar), 63.0 (CH2). The characteristic peak of Elastamine is present at 69.15 ppm.

[0156] The yarns were subjected to bacterial culture testing according to ISO 20743 and ASTM 2315-03. Two bacterial strains were used: Gram-positive bacteria, Staphilococcus aureus (DSM 346) Gram-negative bacteria, Klebsiella pneumoniae (DSM 789) The test was carried out as follows: The PET fabric functionalized with Elastamine RE2000 was chopped into 0.04 g ± 0.05 pieces. The number of specimens used was 6, while the number of specimens of non-functionalized PET was 6. The specimens were placed in a multi-well plate and disinfected with a 70% ethanol (volume / volume) aqueous solution for 30 min. Bacterial growth was then assessed according to ISO 20743 and ASTM 2315-03. Samples prepared using functionalized PET showed bacterial growth potential equal to 8% relative to untreated PET samples (100%) for both Gram-positive and Gram-negative bacteria.

[0157] The antifungal activity was evaluated according to the ISO 13629-2:2014 standard using Aspergillus aculeatus ATCC 36411 as the fungal strain. The functionalized samples showed a mold growth rate equal to 5% relative to untreated PET (100%).

[0158] Example 5 (Preparation of PET-Based Masterbatch with Elastamine RE2000) The procedure given below describes the preparation of yarns based on PET (polyethylene terephthalate) functionalized with Elastamine RE2000 (Huntsman, USA) via direct esterification and condensation polymerization reactions.

[0159] (Procedure for producing yarn) Ethylene glycol and terephthalic acid are provided to an autoclave capable of reflux or distillation. The set conditions are a pressure between 2.7 and 5.5 bar and a temperature between 220 and 260°C. The water generated by the condensation polymerization is removed by distillation. The esterification step may be two-stage, the set conditions for the second stage being 250-270°C and atmospheric pressure. The monomer obtained above is placed in a polymerization reactor, which is operated at 10 to 40 mmHg and 250 to 300°C, and Elastamine RE2000 is continuously added dropwise to the reactor so that the amount of Elastamine RE2000 becomes 30% by weight based on the total weight. The dry polymer obtained above is charged into an extruder together with commercial (non-functionalized) PET to obtain PET functionalized with Elastamine RE2000 at a concentration equal to 5% by weight.

[0160] To evaluate the effectiveness of the functionalization reaction of the yarn obtained by the above method, chemical and physical analyses were carried out according to the following experimental procedures.

[0161] In particular, a conversion rate to functionalization equal to 97% was observed after washing with sodium dodecyl sulfate equal to a concentration (weight / volume) of 5% in water at 40, 60 and 80° C. Typical signals of PET can be found in the following spectrum: δ 167.6 (C=OR), 133.1 (C Ar), 129.3 (C Ar), 63.0 (CH2). The characteristic peak of Elastamine RE2000 is present at 69.15 ppm.

[0162] The yarns were subjected to bacterial culture testing according to ISO 20743 and ASTM 2315-03. Two bacterial strains were used: Gram-positive bacteria, Staphilococcus aureus (DSM 346) Gram-negative bacteria, Klebsiella pneumoniae (DSM 789) The test was carried out as follows: The PET fabric functionalized with Elastamine RE2000 was chopped into 0.04 g ± 0.05 pieces. The number of samples used was 6, and the number of samples of non-functionalized PET was 6. The specimens were placed in a multi-well plate and disinfected with a 70% ethanol (volume / volume) aqueous solution for 30 min. Bacterial growth was then assessed according to ISO 20743 and ASTM 2315-03. The samples showed bacterial growth equal to 6% relative to untreated PET samples (100%) for both gram-positive and gram-negative bacteria.

[0163] The antifungal activity was evaluated according to the ISO 13629-2:2014 standard using Aspergillus aculeatus ATCC 36411 as the fungal strain. Samples showed mold growth rates equal to 4% relative to untreated PET (100%).

[0164] In the above examples 4 and 5, the masterbatch of the polymer functionalized with polyetheramine is obtained in a polymerization reactor, while in another possible embodiment, the preparation of the masterbatch of PET functionalized with polyetheramine can be obtained by direct reactive extrusion. In this case, the base polymer, i.e. commercial PET, is fed to an extruder together with a polyetheramine, which can be selected from among those mentioned above. In some embodiments, the polyetheramine is added in a range between 10% and 60%, preferably between 15% and 50%, of the total polymer mass. The feeding is carried out using a volumetric feeder, a gravimetric feeder, and a combination of a volumetric feeder and a gravimetric feeder. The components are fed either in solid form (granular or powdery) or in liquid form. The mixing in the extruder with two screws allows the correct residence time and the correct reaction of PET and polyetheramine to be obtained. These conditions ensure the necessary association (by the formation of covalent bonds) to obtain a stable product with durable properties.

[0165] The process can be carried out in an extrusion step at temperatures between 250 and 300° C. and residence times between 60 and 120 seconds as a function of flow rate and type of extruder.

[0166] The resulting filaments, usually having a diameter in the order of millimeters, are then cooled, such as in a water bath at a suitable temperature (for example typically 30° C.), after which the threads are chopped into granules or chips. The thus obtained masterbatch of PET functionalized with polyetheramine can be used as a raw product for the manufacture of threads or yarns, such as multifilaments, typically for use in textile articles.

[0167] In this case, the functionalized PET is fed into the extruder in combination with non-functionalized (i.e., polyetheramine-free) components. For example, during extrusion of the final yarn, non-functionalized PET is added to provide about 5% of the weight content of polyetheramine in the final yarn.

[0168] The increased antimicrobial activity resulting from the modification of polyethylene terephthalate by the addition of polyetheramines to the polymer chain results in a polymeric material suitable for spinning, i.e. forming multifilament or monofilament threads, and the fibers or threads can be converted into woven or nonwoven fabrics, and then into staple fibers from which textile articles can be advantageously manufactured. These textile articles can be advantageously used in clothing, especially sports clothing, due to their ability to reduce malodors caused by bacterial growth. Indeed, antimicrobial activity, including antifungal properties, reduces the growth of microorganisms that are responsible for causing malodors.

[0169] Moreover, such modified polymers have beneficial health and hygiene applications where a reduction in bacterial load, i.e., a reduction in the presence of microorganisms such as bacteria and fungi, is required. For example, textile materials using modified polyesters with improved antimicrobial properties as described herein can be used in gowns, pajamas, sheets, cloths, protective masks, pillowcases, blankets, curtains, bandages and others, especially for use in hospitals as medical and surgical devices. The polymers can also be used to manufacture woven and nonwoven fabrics for furnishings (upholstery, rugs, carpets) in the domestic and automotive sectors, and can also be advantageously used to manufacture filters, especially air filters used in air conditioning systems.

[0170] Polyesters modified with polyetheramines covalently bonded to polyethylene terephthalate monomers can be used in medical and surgical procedures and generally in all areas where polyethylene terephthalate is currently used where a polymer with antimicrobial properties would be beneficial. For example, polyetheramines are used to impart antibacterial properties to polyethylene terephthalate for the manufacture of medical threads and membranes, such as suture threads, angioplasty catheter balloon membranes, bandages, medical membranes, hemodialysis membranes, tendon and ligament reconstruction materials, grafts or artificial blood vessels, surgical meshes, components of artificial heart valves, etc.

Claims

1. An antibacterial polyester containing polyethylene terephthalate and at least a polyetheramine.

2. The polyetheramine reacts with the amino terminal (NH ２ 2. The polyester of claim 1, wherein the aryl groups are prevalently located as chain ends having the formula:

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

4. 4. The polyester according to claim 1, wherein the polyetheramine is present in an amount of at least about 1% by weight, preferably at least about 2% by weight, more preferably at least about 5% by weight, based on the total weight of the polyester, and the amount of polyetheramine is not more than about 50% by weight, preferably not more than about 30% by weight, more preferably not more than about 25% by weight, and even more preferably not more than about 20% by weight, based on the total weight of the polyester.

5. 5. The polyester according to claim 1, wherein the polyester comprises a proportion of polyethylene terephthalate of at least about 50% by weight, preferably at least about 60% by weight, more preferably at least about 70% by weight, even more preferably at least about 80% by weight, based on the total weight of the polyester, and preferably the weight proportion of polyethylene terephthalate is not more than about 99% by weight, preferably not more than about 98% by weight, even more preferably not more than about 95% by weight, based on the total weight of the polyester.

6. 6. The polyester of claim 1 , wherein the polyetheramine has a weight average molecular weight (Mw) of at least about 500 g / mol, preferably at least about 800 g / mol, more preferably at least 1000 g / mol, even more preferably at least about 1500 g / mol, and preferably not more than about 5000 g / mol, more preferably not more than about 3000 g / mol.

7. 7. A textile product comprising the polyester of any one of claims 1 to 6 and selected from the group consisting of staple fibres, continuous monofilament threads, continuous multifilament threads, threads made of spun fibres, fabrics and non-woven fabrics.

8. 8. The textile product according to claim 7, comprising a polyester weight percentage of at least about 40% by weight, preferably at least about 50% by weight, more preferably at least about 60% by weight, based on the total weight of the textile product.

9. 7. Use of the polyester according to any one of claims 1 to 6 for producing a product having antibacterial properties.

10. 7. Use of threads or fibres containing a polyester according to any one of claims 1 to 6 for producing textile products having antibacterial properties.

11. A method for imparting antibacterial properties to polyesters containing polyethylene terephthalate, comprising the step of introducing a polyetheramine into the polyethylene terephthalate chain.

12. 1. A method for producing a polyester comprising the steps of reacting terephthalic acid, ethylene glycol and a polyetheramine at temperatures and pressures sufficient to cause polymerization and formation of a polyester containing polyethylene terephthalate and a polyetheramine.

13. reacting terephthalic acid and ethylene glycol with an excess of ethylene glycol to obtain polyethylene terephthalate having terminal carboxyl groups; 13. A method for producing the polyester containing polyethylene terephthalate and polyetheramine according to claim 12, comprising the step of reacting a terminal carboxyl group with a polyetheramine to obtain a polyester containing polyethylene terephthalate and a polymer chain containing polyetheramine.

14. A method for producing a polyester containing polyethylene terephthalate and a polyetheramine, comprising the step of reacting polyethylene terephthalate and a polyetheramine to obtain a polyester containing polyethylene terephthalate and a polyetheramine.

15. 15. The method of claim 14, further comprising the step of adding a grafting agent or a chain extender.

16. 16. The method of claim 15, comprising the steps of reacting polyethylene terephthalate with a grafting agent or chain extender to obtain a functionalized polyethylene terephthalate; and reacting the functionalized polyethylene terephthalate with a polyetheramine.

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