A METHOD FOR RECYCLING POLYAMIDES FROM WASTE TEXTILE PRODUCTS

Abstract

The present invention relates to a low-cost method for recycling polyamide fibers from textile products, in which the solvent used is recovered and reused in the process. Thus, the recovery of polyamide derivatives, particularly polyamide 6 and 6,6, which are important types in the textile industry, is advantageously achieved using the method described in this invention.

Description

1 Specifications A PROJECT FOR RECYCLING POLYAMIDES FROM WASTE TEXTILE PRODUCTS. METHOD Field of Invention The present invention enables the recycling of polyamide fibers from textile products. The proposed solution involves returning the used solvent to the method in a reusable form. It is related to a low-cost method that is used to generate profit. State of the Art Nylon is a synthetic thermoplastic material. It is primarily used to create fibers, films, and molds. It is a petroleum product used and is a general member of the family of synthetic polymers consisting of polyamides (PA). It is the name. Polymers can be mixed with various additives to achieve different properties. Nylon is the world's first fully synthetic polymer fiber. It was originally used for making socks. Nylon is used in many different textile products due to its flexibility as well as its strength and durability. It is used in production. However, it is produced both from petrochemicals and biologically. It is not sustainable because it cannot be broken down. Nylon production is a very potent greenhouse gas. It produces nitrous oxide. In addition, the production process is highly energy-intensive. 20 Increased use of plastic is leading to the accumulation of plastic in the environment. These plastics are more... then they become microplastics, a global pollutant. These polymeric particles, It affects the ecosystem by increasing ecotoxicity and disrupting biogeochemical cycles. Furthermore... microplastic particles, organic pollutants and various other 25 including heavy metals They are also known for their role in exacerbating the effects of environmental pollutants. For all these reasons, like other polymeric materials, nylon also generates emissions during its production. reducing losses and recycling waste products that have reached the end of their economic life cycle Transformation is extremely important. 30 In recent years, the textile and fashion industry has been extremely stable in terms of consumption and production volumes. It is showing growth. Large quantities of fiber raw materials are being used and processed. With the chemicals used in its processes, the textile industry is one of the world's largest industries. It has become one of them. However, some production process wastes and end-of-life products 35 situations such as storage, burning, or even uncontrolled dumping into the environment are involved. 2 This is the subject. Therefore, both the waste generated during production and the waste that arises after consumption... The need for methods to recover and reintegrate into the production cycle continues. is doing. Synthetic fibers make up approximately 62% of the textile materials produced, with polyamide accounting for 5% of this figure. It constitutes approximately 5% of the fraction. In addition, different types of natural or polyamide are used in textile products. It is used in blends with synthetic fiber materials. Polyamide 6 (PA 6) offers superior properties. Thanks to its mechanical properties, it is resistant to wear, tear, or chemical corrosion. It is resistant. For this reason, it is frequently used in blended textile products. For example, polyamide (PA) and Textiles made from polyurethane (PU) are very flexible, repel water from the surface, and allow air to pass through. textiles made from polyamide and polyethylene terephthalate (PET) offer good abrasion resistance and wrinkle resistance. It has high resistance and shape retention properties; it is also made of a blend of polyamide and cotton. Textiles have good moisture and sweat permeability. The compositions are combined in varying proportions. By introducing these, it is possible to increase the number and variety of these samples. However, these compositions... The separation of PA from the resulting fiber products and their recycling in a way suitable for reuse. 15 The transformation presents itself as a technical problem. Therefore, only 2% of the total amount of PA produced (5.58 million tons in 2019) is recycled. This stems from various processes. This leads to environmental pollution and economic losses. For example... PA-based wastes contribute to microplastic pollution in aquatic environments (from fishing nets and synthetic textiles 20 This leads to some environmental problems (such as those resulting from the washing of fibers). Available PA recycling processes in this field include thermomechanical and solvent dissolution methods. It is divided into three main categories: chemical recycling and other recycling programs. In thermomechanical recycling, PA waste is mechanically extruded for reprocessing. They are ground up. This grinding process uses fishing nets, carpets, and pre-consumer industrial waste. This process is carried out in a similar way to PET recycling, where the raw materials are first cleaned, and then... It is ground, melted, filtered, and formed into pellets. The resulting pellets undergo a melt fiber spinning process. It is carried out. Thermomechanical recycling is advantageous in terms of environmental impact and cost. 30 However, the application area of ​​this method is limited to the plastics industry and the products that emerge in this sector. This is limited to pre-consumer industrial waste. Chemical or tertiary recycling processes; hydrolysis, pyrolysis, enzymatic degrading it into reusable building blocks through methods such as depolymerization 35 It is based on the principle of being one of the methods that can be used in the production of recycled textile fibers. The main problem in this method, which stands out as such, is the waste raw material to be used in recycling. 3 The requirement is that it must be of very high purity. Therefore, post-consumer waste is a primary method in this process. It cannot be used without the purification step. Otherwise, the final product will not be suitable for application. That is not possible. Furthermore, this method is the most expensive of the three existing methods. Patent document EP 3740362 A1 describes a mixture containing cellulosic components in addition to nylon. water-swellable building blocks from textile waste made from fibers (cotton, viscose, modal, etc.) It describes a method for separating the textile waste in question, its target component, and at least It contains an auxiliary component; where the target component has a density higher than the density of water. It consists of textile fibers that swell with water. However, in addition to cellulosic fibers, synthetic fibers are also used. 10 prepared with polymeric raw materials and mixtures (nylon, polyester, polyurethane, etc.). This method cannot be used for textile fibers. Dissolving with solvent is one of the most suitable methods for recycling. PA's in its dissolution, dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO) or polar solvents such as formic acid are known to dissolve synthetic fiber types. However, 15 by selectively dissolving nylon from textile waste mixed with it The need for methods to obtain high-purity samples still persists. However, PA is derived from post-consumer waste and other synthetic fibers that contain high levels of impurities. Selectively adding 20 of its mixtures (polyurethane, polyester, etc.) to the solvent. There is no commercialized method for selectively extracting nylon in the relevant technical field. prepared with aqueous alcohol mixtures according to the methods suggested by Rietzler and Qianhui for dissolution Salt solutions containing divalent metal cations were used. In these methods, nylon interacts with metals. By forming a complex, it is dissolved in the solvent. However, in these methods, cations To induce decomposition, a high concentration of 25 is added to the solution. This involves adding large amounts of water. Therefore, the processes used for PA dissolution involve... The cost of the solvent mixture far exceeds the economic value of the resulting polymer. When the state of the art is evaluated holistically, it is seen that PA (polymerase inhibitor) is used in textiles. 30 Recycling the final products obtained due to this reason is quite difficult. However, the relevant techniques... The recycling methods described for PA in the field ensure the selective separation of nylon. However, currently there is no method to perform this conversion process without waste, reusing solvents. It is unable to implement this in a way that allows its use and at a low cost. Therefore, the relevant In the technical field, a new, 35-year-old project has been developed for the separation and recycling of PA fiber from waste textile products. The need for economical and effective methods still continues. 4 To address this need, the present invention describes the recycling of polyamide fiber from waste textile products. the solvent used is presented for the purpose of carrying out the transformation. a low-cost and sustainable method where the material is recovered and made usable again. It presents. The method of the present invention is primarily based on the mixing of PA fiber with other Preparing a solution of this using a solvent inert to textile materials, 5 then the PA is precipitated and removed from the solution, and subsequently the solvent used is... They are innovative and advantageous in terms of being regenerated and reused. Brief Description of the Invention In one aspect, the present invention is a method for obtaining polyamide derivatives from textile waste. 10 This method provides the following steps: - Dissolving textile waste with at least one solvent, - filtering out non-polyamide fibers from the resulting mixture, - Precipitation of at least one polyamide derivative in the mixture with a solvent mixture, - Washing at least one polyamide derivative, obtained in solid form, with water, 15 - Recovery of the solvent mixture used after precipitation by evaporation, - Obtaining the final polyamide derivative. In the preferred configurations of the present invention, the polyamide derivative in question is preferably polyamide 6 and / or polyamide 6,6. 20 In the preferred configurations of the present invention, the solvent mixture in question is in the range of 50-70%. The solvent in question contains alcohol, 5-15% water, and 25-35% salt. The alcohols included in the mixture are preferably ethanol, methanol, butanol, hexanol, and mixtures thereof. It is selected from a group containing [specific group]. The salt in the mentioned solvent mixture is preferably Ca2+, 25 A sample containing Li2+, Mg2+, Fe2+, Mn2+ and Zn2+ divalent cations and combinations thereof. It is the salt of a divalent cation chosen from the group. More preferably, the salt in question is Ca2+ or Mg2+. It is a salt of the ion. In other preferred configurations of the present invention, at least 30 dissolved in the mixture Instead of water, a substance more volatile than water and commercially available is used to precipitate and separate a small amount of polyamide derivative. Commonly used acetone, ethers (e.g., diethyl ether), and alcohol group substances (e.g., methanol, ethanol), halogenated hydrocarbons (e.g., dichloroethane, chloroform), esters (ethyl acetate) and their aqueous compounds. It is selected from a group that includes solvents such as solutions. More preferably, the solvent in question, It may contain an alcohol group (e.g., methanol, ethanol). The alcohol mixture in question may also contain water. 35 is able to. The invention also applies preferably to the decantation method of the solvent mixture in question using polyamide. This involves the step of recovering the solvent for reuse after its separation. is doing. In another aspect, the present invention is a polyamide derivative 5 obtained by the method described in the invention. It offers the following polyamide derivatives: preferably polyamide 6 and / or polyamide 6,6. Brief Description of the Figures Figure 1 shows the FT-IR spectra of samples PA1, PA2 and PA3 of the present invention, as well as (A) 4000-400 cm-1, (B) 1700-800 cm-1, (C) 1200-800 cm-1, (D) 1600-1200 cm-1 wave numbers 10 It shows. Figure 2 shows the TGA thermograms of samples PA1, PA2 and PA3 of the present invention, as well as (A). (A) 50 - 800 °C region of the thermogram, (B) 50 - 120 °C region, (C) 410 - 470 °C region and (D) 700 - It indicates the -800 °C region. Figure 3 shows the DSC thermograms of samples PA1, PA2 and PA3 of the present invention and Xc 15. with their values, (A) thermogram 160-240 °C region, (B) thermogram 180 - 230 °C (C) shows the Xc values ​​for samples numbered PA1, PA2 and PA3. Detailed Description of the Invention This detailed explanation includes the method for obtaining the polyamide related to the invention, for a better understanding of the subject. and is described in detail in such a way as to not create any limiting effects. The present invention... Within the scope of this method, polyamide (PA) is produced from different textile fibers in an environmentally friendly and economical way. The process of obtaining the mixture by dissolving it via a specific method is explained. With the present invention, alcohol-water-salt After dissolving PA in the mixture, it undergoes decomposition in a higher concentration than water during the decomposition phase. Recovery of all components of the solvent by using a more volatile solution mixture 25 This is provided. Thus, polyamide-based, which is an important raw material in the textile industry, is used. products are recycled from waste generated during production and waste generated after consumption. The acquisition is being realized. However, within the scope of the present invention, it is entirely environmental. A method is offered that uses environmentally friendly chemicals that are harmless to human health and produces zero waste. One of the aims of the present invention is to combine different types of fiber materials, especially in textile products. Polyamide derivatives, particularly PA 6 and PA 6,6, which are present in mixtures with other substances, have effective, low-efficiency properties. It is costly and requires high-purity recycling. The inventors have demonstrated the reversible interaction of carbonyl groups of PA with divalent cations such as Ca2+, Li2+, Mg2+, etc. to complex the solution, use alcohol solutions of salts containing the cations in question. 6 They aim to selectively obtain PA in this form. With the method of the present invention. PA 6 and 6,6 can be recycled without producing any waste. Recycling of PA, now known as Nylon®, is only possible from pure waste materials. This can be achieved through thermomechanical methods or via depolymerization. 5 Depolymerization processes are a costly way to break down nylon into its monomers. It is obtained by decomposition. Furthermore, high yields are required to obtain the final product again from monomers. Costly processes are used. This invention offers a solution to the above problems, PA fibers need to be separated from the accompanying substances (e.g., polyurethane, polyester, (cotton, etc.) an inert solvent is used and PA is precipitated and removed from the solution, 10 The solvent in question can then be regenerated and reused. The present invention, in one aspect, concerns the production of polyamide derivatives from textile waste, as defined in the invention. It provides a method for this purpose, and this method includes the following steps: - Dissolving textile waste with at least one solvent, 15 - filtering out non-polyamide fibers from the resulting mixture, - Precipitation of at least one polyamide derivative in the mixture with a solvent mixture, - Washing at least one polyamide derivative, obtained in solid form, with water, - Recovery of the solvent mixture used after precipitation by evaporation, - Obtaining the final polyamide derivative. 20 The method of invention also preferably involves the recovery of the solvent mixture in question by the decantation method. It involves the step of obtaining the solvent. Thus, the solvent can be obtained without the need for a high heat treatment. The mixture can be recovered. In preparing the solvent mixture involved in the method of the present invention, preferably 50-70% alcohol in the range of 5-15%, water in the range of 25-35%, and salt in the range of 25-35%. It is used. In one example, preferably 60% is used in preparing the solvent for the method in question. It uses 10% alcohol, 10% water, and 30% salt. In another example, the word In preparing the solvent for the method in question, preferably 50% alcohol and 15% water are used. 30 and 35% salt is used. The solvent with these ratios in the present invention Thanks to the mixture, the PA fiber remains in bundles during interaction (complexation) with salt. By preventing entanglement and swelling, polyamide is obtained in the appropriate form and faster. It is precipitated as such. In addition, the inventors state that the solvent mixture of the invention is low. They state that it is also possible to evaporate it at these temperatures. 35 7 According to the method described in the invention, the alcohol included in the solvent mixture shall preferably be ethanol, methanol, or butanol. It is selected from a group containing hexanols and their mixtures. Polyamide carbonyl For reversible complexation of divalent cations with their groups, preferably Ca2+, Li2+, Mg2+, Fe2+, An alcohol is the salt of at least one cation selected from a group containing Mn2+ and Zn2+ divalent cations. Solutions are used. Thus, polyamide is selectively obtained in solution form. 5 It is possible. The inventors specifically designed solution mixtures containing salts of Ca2+ and Mg2+ cations. It is more effective in the precipitation of polyamide compared to the other cations mentioned. They have noticed that the salts of these cations make complexation more efficient. It has been observed that, in this way, polyamide fibers can be separated and obtained in solution form. In an example of the present invention, polyamide-containing particles are mixed within the prepared solution. The polyamide is stirred at a temperature between 40 and 100 °C until it is completely melted. Undissolved particles are filtered out of the solution. Afterwards, 15... Decomplex formation is achieved in order to obtain dissolved polyamide. In the preferred configurations of the present invention, after the precipitation of the polyamide derivative, water a solvent that is insoluble in the phase, to recover the precipitating solvent by decantation can be used. The solvent in question, which is insoluble in water, is preferably benzene, toluene, chloroform, or methyl 20. ethyl ketone, methyl iso butyl ketone, trichloroethylene, cyclohexane, perchlorethylene, methylene chloride, ethyl acetate and is selected from a group that includes combinations of these. In this case, any thermal The precipitating solvent used by decantation without the need for processing is also recycled. Alternatively, the precipitate formed in the method described in the invention can be recovered from the solution. A filter pressing process can also be used for removal purposes. 25 In the method described in the present invention, the polyamide is more volatile than water during the decomplication phase. treatment with solvents results in obtaining the product using much smaller amounts of solvent compared to water. This is being demonstrated for the first time with the present invention, which enables its use with water. The inventors Decomposition causes the formation of large amounts of mixtures during the precipitation phase. 30 and that it is possible to commercially recover the chemicals used in the process. They have concluded that it is not the case. In other words, inventors offer a solution to existing problems in technology, thus providing a solution. 35 with the aim of promoting the reuse of all its components and creating zero waste. Instead of adding excessive water, much smaller amounts of volatile mixtures are used for precipitating polyamide. They discovered that being treated that way was advantageous. 8 Within the scope of the method of the present invention, the decomplexation process is carried out on polyamide. During the production process, preferably acetone or ethers, which are more volatile than water and are commercially widely used, are preferred. (e.g., diethyl ether), alcohol group (e.g., methanol, ethanol), halogenated hydrocarbons (e.g., solvents such as dichloroethane, chloroform), esters (e.g., ethyl acetate) and their aqueous solutions or mixtures thereof are used. Within the scope of the present invention, the solvent in question is 5 It has been observed that the mixtures provide the most economical decomposition. Here, the alcohol-water mixture... It preferably contains 55% alcohol and 45% water. This alcohol-water mixture, with these ratios, is divalent. By enabling the effective removal of cations, it quickly produces pure polyamide. It has been observed that it makes it possible to obtain its derivatives. Further details of the volatile solvent mixture or volatile solvent-water mixture related to the present invention By using an alcohol-alcohol or alcohol-water mixture, 1 unit by mass of polyamide solution Instead of 10 units of water per head as in known state of the art methods, 0.5 to 3 units are used. Recycling of polyamide is possible through the use of solvents. Therefore, the present invention... In the method in question, a more volatile solvent is used, allowing the solvent to be easily absorbed. 15 The fact that it can be recovered after processing makes the current invention advantageous. Furthermore, this allows for high efficiency. instead of obtaining a large, dilute aqueous solution, a smaller amount and a higher volume A sustainable and low-cost method thanks to the use of an efficient solvent. This has been demonstrated. Alternatively, in the method related to the present invention, flash evaporation of the aforementioned solvent mixture is possible. The direct removal of polyamide through processes such as distillation and spray drying It may also be possible to obtain it in solid form. In this alternative structure, the solvent in question... After the fibrous materials were removed from the mixture, the solvent, which was in gaseous form, was removed. The mixture can be cooled and reintroduced into the method in liquid form. 25 In another aspect, the present invention is a polyamide derivative obtained by the method described in the invention. It provides. The polyamide derivative in question may be polyamide 6 and / or polyamide 6,6. The method of the present invention involves obtaining the remaining 30 after recycling the polyamide product. to obtain all components in the filtrate separately and complete the process with a zero-waste principle. It provides. In a more advanced development of the method of the present invention, for precipitation paint and salt residue remaining in the solid after the solvent used has evaporated Impurities such as these cause the solubility of the salt in question to be low, while the solubility of the dye is high. They can be obtained separately using a solvent such as 35. For example, the solvent in question is 35 preferably thinner, hexane, ether, chloroform, acetone, benzene, toluene and combinations thereof It could be a solvent selected from a group containing. 9 EXAMPLES In the experimental studies conducted, an industrial pure polyamide 6 (PA-6) raw material sample was used. PA1 is a commercially used recycled PA-6 raw material, PA2 is available The new recycled PA-6 sample presented using the method related to the invention is designated as PA3. It has been named. Fourier transform infrared 5 for the study of the three samples in question. spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) tests have been performed and the results obtained within the scope of the present invention are as follows: It is being detailed. ATR-FTIR Analyses: 10 When the FT-IR spectra of samples coded PA1, PA2 and PA3 were examined; in the amide-A region (3500- 2700 cm-1) 3300 (amide group NH stretching band), as reported in the literature, up to 50 cm-1. Since no shift to lower wave numbers occurred, the shift in question was essentially Ca2+ Since it is known that PA1 and PA2 arise from hydrogen bonds formed through coordination, Decomplexation in the samples was successfully achieved (Figure 1). 1438 cm-1 wave 15 The deflection of CH2 groups attached to deviated amide nitrogen atoms, as seen in number [number], is a deviation from ideal behavior. The bands show similarities to the spectra of decomplexed PA-6 reported in the literature. Coordination with Ca2+ causes a deviation from the absolute trans conformation as shown. It has been observed to disappear. In the spectra of PA3 and PA2 samples, wave numbers of 1122 cm-1 and 1076 cm-1 are observed. The peaks shown are the fully-trans CC main chain, which is shown in the literature as 1130 cm-1 and 1065 cm-1. It is attributed to the peaks belonging to the conformation (Figure 1, C). In general, PA-6 / CaCl2 In these complexes, a single peak observed in this region at a wave number of 1080 cm-1 is entirely trans C- The C main chain conformation completely disappears and the gauche conformation occurs. 25 This indicates that it has arrived. However, these two peaks reappeared in the decomplexed PA-6 structure. This indicates that the complex has degraded, returning to a conformation close to pure PA-6. When the spectra of samples coded PA2 and PA3 were examined, they were around 960 cm-1 and 930 cm-1, respectively. The resulting peaks, which indicate the formation of PA-6 α-crystalline morphology, are similar. This is observed (Figure 1, A and C). The presence and location of these peaks indicate that in the presence of Ca2+ cations, 30 PA-6, which had formed a complex and transformed into an amorphous structure, recrystallized, and the complex... This indicates that it has deteriorated. In general, the recyclable products already available on the market... PA2, which is a sample of the material, and PA3, which is obtained by the method that is the subject of the present invention. The spectra of the sample were found to show a high degree of similarity. 35 TGA Analyses: The moisture content of three different samples (PA1, PA2 and PA3) was determined from the TGA thermograms of the samples. The water content and inorganic residue amount were determined (Figure 2). The water content in the samples was measured at 50–120°C. PA-6 content was measured by mass output between 290–500°C (Figure 2, B). The bending points are shown by measuring the decrease in mass at each step (Figure 2, A and C). 5 The remaining inorganic balance was automatically calculated by the program for 800°C. PA1, PA2 and PA3 The initial moisture content of the samples was measured as 0.23%, 0.94%, and 2.64%, respectively. PA-6 content was found to be 94.48%, 86.65%, and 92.29% by mass, respectively. Here, PA-6 The inflection point of the curve is considered to be the intermediate temperature value at which decomposition occurs. The bending point values ​​for the three samples were 458.4°C, 421.8°C, and 443°C, respectively. This has been calculated. As can be understood from these values, it is the most successful in terms of thermal stability. The sample was PA1, and the other sample that showed a closer performance was PA3. The remaining inorganic residue / impurity amounts were determined to be 2.11%, 0.95%, and 1.77%, respectively. This was obtained as follows. The sample with which the method presented within the scope of the present invention shows the best agreement. It was determined that the sample was PA3 and that PA3 contained low impurities. 15 DSC Analyses: When the second heating curves of the DSC thermograms of samples PA1, PA2, and PA3 were examined; Sample PA1, with its pure PA-6 structure, belongs to recycled industrial samples PA2 and PA3. The thermograms melted, peaking at 220°C (Figure 3, A and B). 20 of the three samples in question... Melting enthalpies were measured and crystallinity fractions (Xc) of PA-6 samples are given below. The area was calculated according to the formula: 𝑿𝐜 = 𝚫𝑯𝐦 𝚫𝑯𝐨 ×𝝎PA6 (1) In the equation above, ΔHm is the melting enthalpies (J / g) determined by DSC, and ΔH0 is 25 for α and ν-crystallites. The calculated melting enthalpy of pure PA-6 is 240 J / g2, and ωPA6 represents the amount of PA-6 in the sample. It represents the mass fraction. PA-6 mass fractions (ωPA6) measured with TGA thermograms, The percentages for PA1, PA2, and PA3 are 94.48%, 86.65%, and 92.29%, respectively (Figure 3, C). The Xc values ​​of the samples were calculated as 10.84%, 11.35%, and 10.76%, respectively. The values ​​of the three samples (PA1, PA2, PA3) obtained with the invention are close to each other. 30 It is seen. As can be seen in light of what has been described above, the method of the invention is an improvement over existing methods. an innovative system that overcomes its limitations, adopting the principles of speed, low cost, and zero waste. 11 This approach represents a solution for the recovery of polyamide 6 and 6,6 with these features. It will be a valuable tool. The scope of protection of the present invention is set out in the attached claims, and this detailed description includes examples. It is obvious that it cannot be limited to what has been described for this purpose. A person who is an expert in the field would know the above. In light of what has been described, and considering the scope of the invention, it is possible to produce similar materials. 5 He / She will understand.

Claims

12 REQUESTS 1. This is a method for obtaining polyamide derivatives from textile waste, and its characteristic feature is... The method in question involves the following steps: - Dissolving textile waste with at least one solvent, 5 - filtering out non-polyamide fibers from the resulting mixture, - Precipitation of at least one polyamide derivative in the mixture with a solvent mixture, - Washing at least one polyamide derivative, obtained in solid form, with water, - Recovery of the solvent mixture used after precipitation by evaporation, - Obtaining the final polyamide derivative. 10 2. The method presented in accordance with Claim 1 is characterized by the fact that the polyamide derivative in question is polyamide 6 and / or polyamide 6,6.

3. The method presented according to Claim 1, characterized by the fact that the solvent mixture in question contains 50-70% 15 It contains between 5-15% alcohol, 25-35% water, and 25-35% salt.

4. The method presented in accordance with Claim 3 is characterized by the fact that the alcohol in question is converted into ethanol, methanol, butanol, It is selected from a group containing hexanol or mixtures thereof.

5. The method presented according to Claim 3 is characterized by the fact that the salt in question contains Ca2+, Li2+, Mg2+, Fe2+, Mn2+ and A divalent cation selected from a group containing Zn2+ and combinations thereof. It has salt.

6. The method presented according to claim 5, the characteristic of which is that the salt in question is preferably Ca2+ or Mg2+ 25 It is a salt of the ion.

7. The method presented in accordance with Claim 1 is characterized by the fact that the solvent mixture in question consists of acetone, ether, diethyl ether, methanol, ethanol, dichloroethane, chloroform, ester, ethyl acetate or any of these It is the selection of a group containing mixtures. 30 8. This is the method offered according to any of the previous requests, and its characteristic is... The method also involves recovering the solvent mixture in question through decantation. It includes the step. 35 9. A polyamide derivative obtained by the method presented according to Claim 1. 13 10. The polyamide derivative presented pursuant to Claim 9 has the characteristic that the said polyamide derivative is a polyamide. It must be 6 and / or polyamide 6,6.

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