Process for depolymerizing polyamides by hydrolysis

Abstract

A process for depolymerizing polyamide 6 prepared from ε-caprolactam by hydrolysis, comprising: (i) supplying a chemical raw material F comprising polyamide 6 and further comprising at least one further organic polymer compound; and (ii) a liquid aqueous stream S W (iii) The steps of supplying the raw material F and (iii) supplying the raw material F to stream S W The mixture is mixed with the reaction unit U R A aqueous stream S is subjected to depolymerization conditions for polyamide 6 and contains one or more decomposition products of ε-caprolactam and at least one further organic polymer compound. E (iv) an aqueous stream S containing at least a portion of water and at least a portion of at least one of the one or more decomposition products contained in the stream S. R (v) the aqueous stream S R At least a portion of the chemical reaction unit U R A process that includes the step of supplying and returning to the source.

Description

[Technical Field]

[0001] The present invention relates to the hydrolytic (i.e., by hydrolysis) depolymerization of polyamide 6, which results in an increased yield of ε-caprolactam by at least partially returning (recycling) the aqueous stream generated downstream of the hydrolytic depolymerization reaction back into the hydrolysis reaction. [Background technology]

[0002] Polyamide, specifically the formula (-NH-(CH2)5-CO-) n Polyamide 6, characterized by [specific characteristics], can be found in many materials, such as packaging, automotive engineering plastics, and fiber filaments. The latter accounts for approximately 40% of the global market for polyamide 6. Currently, only a small portion of fiber filaments is recycled, yet it accounts for a significant portion of global CO2 emissions. Therefore, there is a need to recycle polyamide 6 from such materials. Processes exist for the alkali depolymerization of polyamides. Furthermore, the processes in this art are energy-intensive. Moreover, the materials subjected to such recycling processes often contain other polymer compounds, such as polyamide 6, polyurethane, polyester, polyethylene terephthalate, etc., which usually complicates recycling. Therefore, there is a need to provide an improved process for hydrolytically depolymerizing polyamide 6 contained in materials that, in addition to polyamide 6, also contain at least one other polymer compound. [Overview of the Initiative] [Problems that the invention aims to solve]

[0003] Surprisingly, in the process of the present invention where polyamide 6 is depolymerized by hydrolysis and the feedstock subjected to the hydrolysis depolymerization process contains at least one further polymer compound, it has been found that it is possible to increase the yield of ε-caprolactam, a valuable product which is a monomer compound resulting from the depolymerization of polyamide 6. More specifically, the process of the present invention makes it possible to reduce the overall energy consumption as compared to known processes which make it possible to reduce the CO2 footprint and costs.

Means for Solving the Problems

[0004] Therefore, the present invention is a process (method) for depolymerizing polyamide 6 by hydrolysis, comprising: (i) supplying a chemical feedstock F containing polyamide 6 and further containing at least one further organic polymer compound; (ii) supplying a liquid aqueous stream S W ; (iii) mixing the chemical feedstock F supplied according to (i) with the stream S supplied according to (ii), and subjecting the resulting mixture to the depolymerization conditions of polyamide 6 including the depolymerization temperature T W of polyamide 6 and the depolymerization pressure p R in a chemical reaction unit U D to obtain an aqueous stream S D exiting from U R , wherein the stream S E contains one or more decomposition products of ε-caprolactam and one or more of the at least one further organic polymer compound; E and (iv) generating an aqueous stream S E containing at least a part of at least one of at least a part of water and at least one of the one or more decomposition products contained in the stream S R , wherein the stream S R has a depleted ε-caprolactam as compared to the stream S E . (v) Water-based Stream S W As part of the Aqueous Stream S R At least a portion of the chemical reaction unit U R The step of supplying and returning This includes processes related to the process.

[0005] Preferably, according to the present invention, no depolymerization catalyst for polyamide 6, such as one or more mineral acids, such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and / or zinc salts, such as zinc chloride, zinc acetate, or zinc triflate, are added to prepare a mixture subjected to the depolymerization conditions for polyamide 6 by hydrolysis.

[0006] In addition to ε-caprolactam monomer compounds, Stream S E Preferably, it further comprises one or more of ε-caprolactam dimer and aminocaproic acid.

[0007] In accordance with (i), the at least one further organic polymer compound contained in the raw material F preferably includes at least one polyamide 6.6; at least one semi-aromatic polyamide including one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer of two or more polymer compounds including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and at least one rubber material including one or more of at least one natural rubber material and at least one synthetic rubber material.

[0008] According to the present invention, it is preferable that at least one of the at least one further organic polymer compounds contained in the chemical raw material is polyurethane. Therefore, preferably, the present invention is a process for depolymerizing polyamide 6 by hydrolysis, the process comprising the following steps: (i) A step of supplying a chemical raw material F comprising polyamide 6 and at least one polyurethane, and optionally further comprising at least one additional organic polymer compound, (ii) Liquid Aqueous Stream S W The steps of supplying, (iii) Chemical raw material F supplied according to (i) to stream S supplied according to (ii) W The mixture is mixed with the chemical reaction unit U R Within the structure, the depolymerization temperature T of polyamide 6. D and the depolymerization pressure p of polyamide 6 D The polyamide 6 containing U is subjected to depolymerization conditions, R Water-based Stream S E A step to obtain stream S E However, the step includes one or more degradation products of ε-caprolactam and at least one further organic polymer compound, (iv) At least a portion of the water and stream S E Aqueous Stream S containing at least one portion of one or more degradation products contained in R A step of generating the stream S R However, Stream S E In comparison, ε-caprolactam is depleted, step, (v) Water-based Stream S W As part of the Aqueous Stream S R At least a portion of the chemical reaction unit U R The steps include supplying and returning, The process relates to one or more of the following: (i) a further organic polymer compound preferably comprising at least one polyamide 6.6; at least one semi-aromatic polyamide comprising one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer of two or more of the polymer compounds comprising statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and at least one rubber material comprising one or more of at least one natural rubber material and at least one synthetic rubber material.

[0009] In addition to at least one further organic polymer compound, the raw material F supplied by (i) may further contain other chemical compounds. These compounds may include, for example, one or more of at least one pigment material and at least one glass fiber material. For example, such a pigment material may include an organic or inorganic pigment, such as TiO2.

[0010] According to (iv), an aqueous stream S comprising at least a portion of water and at least a portion of at least one of the one or more decomposition products obtained according to (iii) R A is generated, and then its stream S R It is reused (recycled) according to (v). Preferably, stream S R , more Stream S RAt least one of the one or more decomposition products contained in comprises at least one amine, at least one ketone, at least one ether, at least one amide, and at least one alcohol, wherein the at least one amine preferably comprises at least one aliphatic amine and at least one aromatic amine, the at least one ketone preferably comprises at least one aliphatic ketone, the at least one ether preferably comprises at least one aliphatic ether, the at least one amide preferably comprises at least one aliphatic amide, and the at least one alcohol preferably comprises at least one aliphatic alcohol.

[0011] More preferably, Stream S R , more Stream S R At least one of the one or more degradation products contained in includes one or more of aniline, 4-aminotoluene, 2,2-dimethoxy-3-methylbutane, 3,3-dimethoxypentane, dimethylacetamide, tripropylamine, 2-octanol, 2,2-dimethoxybutane, and cyclopentanone, where aniline is preferably Stream S R It is included in, preferably, Stream S R It is included in at least one of the one or more degradation products contained in it.

[0012] More preferably, Stream S R This comprises ε-caprolactam, and preferably one or more of N-ethylcaprolactam and 3-(2-oxazepan-1-yl)propanal.

[0013] As described above, the at least one further organic polymer compound contained in the supply raw material F preferably includes at least one polyurethane, and stream S E This comprises one or more decomposition products of the at least one polyurethane, where stream S RThis includes at least a portion of at least one of the one or more decomposition products described above. More preferably, one or more of the at least one polyurethane contained in the supply material F is prepared from at least one aniline-based isocyanate, S R One or more of the decomposition products contained in it include aniline.

[0014] Generally, the chemical raw material F may consist of a single material or several different materials; that is, the chemical raw material F may consist of w chemical materials M j (where j=1..w and w≧1). Furthermore, according to the present invention, chemical material M is preferably used. j At least one, more preferably all, of the chemical materials M j This includes, preferably consists solely of, waste, which preferably includes, one or more of, at least one fiber waste and at least one engineering plastic waste, more preferably consists solely of them, more preferably includes, and more preferably consists solely of, at least one fiber waste. If w > 1, each of the two or more materials may have different chemical compositions, provided that the chemical raw material F exhibits the above-described composition, and is not subject to any particular limitations.

[0015] While there are no specific limitations on each, it is preferable that 10 to 100% by weight, more preferably 20 to 100% by weight, more preferably 30 to 100% by weight, more preferably 40 to 100% by weight, more preferably 50 to 100% by weight, and more preferably 60 to 100% by weight of the supply material F consist solely of polyamide 6 and at least one further organic polymer compound. Generally, possible ranges for each may be, for example, 70 to 100% by weight, or 80 to 100% by weight, or 90 to 100% by weight, or 95 to 100% by weight, or 98 to 100% by weight, or 99 to 100% by weight. Preferred weight ratios of polyamide 6 to the at least one further organic polymer compound are 1.6:1 to 4:1, 1.6:1 to 1:6:1, 1.6:1 to 1:6:1, 1.8:1 to 3:1, or 1.2:1 to 8:1, or 1.4:1 to 6:1, or 1.8:1 to 3:1.

[0016] With respect to the chemical raw material F supplied in accordance with (i), it is preferable that it be provided in solid form, and more preferably in particle form, for example, in particle form.

[0017] Preferably, the particle size distribution is characterized by one or more pairs of the following values, more preferably two or more pairs of the following values, and more preferably three pairs of the following values: - D10 values ​​for particle widths in the range of 0.3 to 15 mm and D10 values ​​for particle lengths in the range of 0.3 to 15 mm. - D50 values ​​for particle widths in the range of 0.5 to 20 mm and D50 values ​​for particle lengths in the range of 0.5 to 20 mm. - D90 values ​​for particle widths ranging from 0.8 to 30 mm and D90 values ​​for particle lengths ranging from 0.8 to 30 mm.

[0018] A more preferable pair of values ​​would be, for example, - D10 values ​​for particle widths in the range of 2 to 4 mm and D10 values ​​for particle lengths in the range of 3.5 to 5.5 mm. - D50 values ​​for particle widths in the range of 2.5 to 4.5 mm and D50 values ​​for particle lengths in the range of 4 to 7 mm. - D90 values ​​for particle widths in the range of 3 to 5 mm and D90 values ​​for particle lengths in the range of 4.5 to 8.5 mm That is the case.

[0019] As used in this context of the present invention, the term "particle" may optionally include pre-formed granules and may also include fine fragments.

[0020] According to the first alternative method of the present invention, the chemical raw material F is in solid form in a liquid aqueous stream S W And are mixed according to (iii). According to this alternative method, (i) (i) A step of supplying a chemical raw material F in solid form, the step of the supplied raw material having a temperature below the melting point of polyamide 6, (ii) (ii) Liquid Aqueous Stream S W A step of supplying S W 90 to 100% by weight consists of water, and S W The further step involves having a temperature below the melting point of polyamide 6, (iii) (iii) Solid chemical raw materials supplied according to (i) and liquid aqueous stream S supplied according to (ii) W chemical reaction unit U R It is supplied to obtain a mixture, U R The above mixture inside, polyamide 6 at temperature T D A step of subjecting polyamide 6 containing to depolymerization conditions, wherein T D However, the temperature of the liquid aqueous stream S supplied according to (i) is higher than the temperature of the raw material supplied according to (ii). W A process that includes further steps at temperatures lower than the specified temperature may be preferable.

[0021] According to a second alternative method of the present invention, supplying a chemical raw material F according to (i) includes the step of converting the chemical raw material F from a solid form to a liquid form, and according to (iii), the chemical raw material F is in liquid form into a liquid aqueous stream S W It is mixed with this. With respect to this alternative method, the process of the present invention is preferably, (a) A step of supplying raw material F in solid form, (b) Melting Unit U M In this process, the solid raw material F is melted, and pressure p SM At temperature T SM Liquid Stream S M Steps to obtain, (c) pressure p SW At temperature T SW Liquid aqueous stream S W The steps of supplying, (d) Pre-reaction (preliminary reaction) unit U PR In Stream S M Stream S W When mixed with, pressure p SF At temperature T SFA liquid reaction feed stream S having F the step of obtaining; (e) Stream S F is supplied to a chemical reaction unit U R and in it, the depolymerization temperature T of polyamide 6 R and the depolymerization pressure p of polyamide 6 D are subjected to the depolymerization conditions of polyamide 6 including, to obtain an aqueous stream S D exiting from U R where stream S E contains one or more decomposition products of one or more of ε-caprolactam and at least one further organic polymer compound; E and may be included.

[0022] According to the method including these steps (a) to (e), 0.8 ≦ T SF / T D ≦ 1.05, and 0.9 ≦ p SF / p D ≦ 1.05 is preferred. 0.6 ≦ T SM / T SF ≦ 1.05, and 0.9 ≦ p SM / p SF ≦ 1.05 is even more preferred. Even further, 0.8 ≦ T SW / T SF ≦ 1.3, and 0.9 ≦ p SW / p SF ≦ 1.05 is preferred. Further, according to this method including steps (a) to (e), the pre-reaction unit U PR in (d) comprises a mixing unit, preferably a static mixing unit, and preferably consists only of it. As used herein, the term "static mixing unit" refers to an arrangement of mixing elements installed in a pipe or duct and operating essentially without moving parts, preferably completely without moving parts. According to the present invention, the pipe for stream S M and stream S W ​​​​​​​​It may be preferable to be configured as an appropriate pipe joint with a pipe for, and there is no specific mixing element. Furthermore, the melting unit U M preferably comprises a kneader or an extruder, more preferably an extruder, and more preferably, the melting unit U according to (ii) M consists only of an extruder, and more preferably, the extruder is a single-screw extruder or a twin-screw extruder, more preferably a twin-screw extruder. Furthermore, according to this method including steps (a) to (e), the melting unit U M downstream of and upstream of the reaction unit U R a filtration unit U F is preferably arranged to separate particles having a particle size in the range of preferably 100 to 500 micrometers, preferably 200 to 400 micrometers from the liquid stream S M from the filtration unit U F wherein the process includes the step of passing the stream liquid stream S M through U F before mixing according to (d).

[0023] Regarding the depolymerization conditions of polyamide 6 according to (iii), they are in the range of 230 to 330 °C, more preferably in the range of 250 to 320 °C, more preferably in the range of 270 to 310 °C, for example in the range of 270 to 280 °C, or 280 to 290 °C, or 290 to 300 °C, or 300 to 310 °C, the depolymerization temperature T of polyamide 6 D is included. The depolymerization temperature T D is the temperature of the liquid reaction mixture during (iii). Furthermore, regarding the depolymerization conditions of polyamide 6 according to (iii), they are in the range of 40 to 140 bar, more preferably in the range of 40 to 125 bar, more preferably in the range of 40 to 110 bar, for example in the range of 40 to 55 bar, or 55 to 70 bar, or 70 to 85 bar, or 85 to 100 bar, or 100 to 110 bar, the polyamide 6 depolymerization pressure p D is included.

[0024] With respect to step (iii), the supply raw material F and stream S W The mixing ratio (m) is in the range of 1:1 to 20:1, preferably in the range of 2:1 to 15:1, and more preferably in the range of 5:1 to 10:1. W (kg) / (m) P It is preferable to mix at a rate of / kg, where m W is S W This is the amount of water contained in m P This is the amount of polyamide 6 contained in the chemical raw material F.

[0025] Chemical reaction unit U R Regarding this, it involves z chemical reactors R i It is preferable to have a reactor R where i=1...z, and z is in the range of 1 to 10, preferably 1 to 8, more preferably 1 to 6, more preferably 1 to 5, more preferably 1 to 4, and more preferably 1 to 3. If z>1, preferably at least two reactors R i , comfortable z reactors R i They are connected in series.

[0026] Chemical reaction unit U R The total residence time of the reaction mixture subjected to the depolymerization conditions of polyamide 6 is in the range of 15 to 800 minutes, preferably in the range of 30 to 600 minutes, more preferably in the range of 45 to 360 minutes, and more preferably in the range of 60 to 240 minutes. The term “total residence time” as used in this context of the present invention applies to all of the above chemical reactor R i This refers to the total dwell time in that location.

[0027] According to the present invention, in particular with respect to the method comprising steps (a) to (e) described above, if z > 1, at least two reactors R i Preferably z reactors R i They are connected in series, and stream S F R i Aqueous liquid stream S containing ε-caprolactam dissolved in water is supplied to (i=1). i Reactor R iis withdrawn from and supplied to reactor R i+1 (where i < z); and an aqueous liquid stream S containing ε-caprolactam dissolved in water z is withdrawn as stream S E from reactor R z ; where in all reactors R i at a depolymerization pressure p Di at a depolymerization temperature T Di is maintained, independently of one another, T Di is in the range from 230 to 330 °C, and p Di is in the range from 40 to 140 bar, preferably T Di is in the range from 250 to 320 °C, and p Di is in the range from 40 to 125 bar, more preferably T Di is in the range from 270 to 310 °C, and p Di is preferably in the range from 40 to 110 bar. Preferably, when z > 1, the z reactors R i are arranged vertically, with R1 being the uppermost reactor and R z being the lowermost reactor, and S i obtained from R i moves to R i+1 by gravity, preferably by gravity alone.

[0028] More preferably, at least one, preferably z reactors R i are stirred tank reactors, and all stirred tank reactors R i may preferably have, independently of one another, from 2 to 6 compartments, preferably from 2 to 5 compartments, more preferably from 2 to 4 compartments, said compartments being preferably arranged in series, more preferably in series and vertically, where two adjacent compartments are separated by a partition containing at least one flow opening. The at least one compartment contained in reactor R i may preferably be equipped with at least one stirrer, preferably all compartments of all reactors R i are equipped with at least one stirrer, more preferably all reactors R iEach section is equipped with a stirrer, wherein the process includes the step of stirring the depolymerized mixture in a given section for at least a portion of the time while it is subjected to the depolymerization conditions in the section.

[0029] Alternatively, regarding the specific design of the aforementioned stirred tank reactor, according to the present invention, at least one stirred tank reactor R i Preferably all stirred tank reactors R i The reactor R has, independently of each other, preferably 2 to 6 compartments, more preferably 2 to 5 compartments, more preferably 2 to 4 compartments, and the compartments are preferably arranged in series, more preferably in series and vertically, and the reactor R i The reactor comprises at least one stirrer, and two adjacent compartments are formed and separated by one or more suitable components of the stirrer, for example, blades included in the stirrer, wherein the process particularly preferably includes the step of stirring a depolymerization mixture in a given compartment for at least a portion of the time it is subjected to depolymerization conditions in the reactor compartment.

[0030] The depolymerization conditions for polyamide 6 are preferably unit U R Preferably z reactors R i More preferably, the total residence time t of the aqueous depolymerization mixture in z stirred tank reactors D The mixture further comprises at least 85% by weight, preferably at least 90% by weight, and more preferably at least 95% by weight of the aqueous depolymerization mixture, in the range of 30 to 90 minutes. D It has. More preferably, when z > 1, reactor R i The residence time of the aqueous depolymerization mixture inside is t Di And, 0.90 ≤ (t Di / t Di+1 )≦1.10, preferably 0.95≦(t Di / t Di+1 ) ≤ 1.05.

[0031] Preferably, according to the present invention, aqueous stream S according to (iv). R To generate reaction unit UR Stream S obtained from E Depending on the choice, S E After being subjected to filtration, it is subjected to hot water separation, and Stream S R The process includes the step of obtaining the following. The hot water separation is preferably comprised of one or more of evaporation and distillation, more preferably distillation and one or more of flowing membrane evaporation, although it is not limited to any particular method. R To generate reaction unit U R Stream S obtained from E Depending on the choice, S E After being filtered, it is distilled and Stream S R The process includes, more preferably consists of, the step of obtaining the following: The distillation is preferably carried out in a distillation column, preferably with a bottom temperature in the range of 70 to 140°C, more preferably 80 to 120°C, more preferably 90 to 110°C, and a top pressure in the range of 0.5 to 1.5 bar, more preferably 0.7 to 1.2 bar, more preferably 0.8 to 1.1 bar, and the stream S R This is obtained at the top of the distillation column. Furthermore, the distillation preferably involves condensing the vapor top stream to produce a liquid stream S. R The step includes obtaining a liquid stream S R At least a portion of it is aqueous stream S according to (v). W Chemical reaction unit U as part of the chemical reaction unit R The liquid stream S obtained by condensation is supplied and returned. R The first stream obtained from the split is the aqueous stream S according to (v). W Chemical reaction unit U as part of the chemical reaction unit R The first stream is supplied and returned to the top of the distillation column, and the volume ratio of the first stream to the second stream is preferably in the range of 10:1 to 0.5:1, more preferably in the range of 7:1 to 1:1, and more preferably in the range of 5:1 to 2:1.

[0032] Furthermore, preferably according to (iv), aqueous stream S R Stream S E to U R Stream S containing purified ε-caprolactam, which is produced in the process of being subjected to one or more downstream steps. CPL The material is prepared and may then be appropriately reused (recycled) in the material value chain, for example, as a starting material for preparing polyamide 6. Stream S E The heat contained therein is appropriately recovered and the one or more downstream purification steps may further include one or more steps used to at least partially satisfy the heat demand of one or more of the downstream purification steps, for example, the following series of steps: (A) Liquid Aqueous Stream S E Evaporation unit U E Pass through to S E From, c SL >c SR The concentration c SL Aqueous aqueous Stream S containing ε-caprolactam dissolved in water L Having obtained, and furthermore S E From one or more water vapor streams S V Steps to obtain (B) Water-based Stream S L Heat consumption purification unit U P Pass through to S L From, c SCPL >>c SL The concentration c SCPL Stream S containing ε-caprolactam CPL Having obtained S L From one or more water-based stream S RW A step to obtain U P At least a portion of the heat consumed in one or more streams S V Provided by at least one of the following, thereby providing at least one stream S V From at least one at least partially condensed aqueous stream S VW To obtain, step, (C) Stream S RTherefore, at least partially, at least one stream S VW and at least partially at least one stream S RW reaction unit U R The step of reusing (recycling).

[0033] Reuse (recycling) by (C) is preferably, (C.1) at least one stream S VW and at least one stream S RW water treatment unit U W To supply U W From at least one water-based reuse (water-based recycling) stream S R Steps to obtain, (C.2) At least one aqueous stream S as described above R at least partially react unit U R The steps to reuse (recycle) It may include.

[0034] (C.1) Water treatment unit U W Preferably, the water recovery unit U WR and wastewater unit U WW It may also be provided, and (x.1) is, (C.1.1) at least one stream S VW and at least one stream S RW Water recovery unit U WR To supply U WR From at least one water-based reuse (water-based recycling) stream S W and at least one aqueous stream S SW Steps to obtain, (C.1.2) At least one stream S above SW wastewater unit U WW To supply U WW From at least one wastewater stream S WW Steps to obtain It also includes.

[0035] (B) Purification unit U P Preferably, a heat-consuming water separation unit (heat-consuming water separation unit) U WS , a distillation unit that consumes heat (heat-consuming distillation unit) U D , and a heat-consuming crystallization unit (heat-consuming crystallization unit) U C One or more of the following, preferably a heat-consuming water separation unit U WS , heat consumption distillation unit U D , and heat consumption crystallization unit U C Two or more of the following, Comfortable Heat Consumption Water Separation Unit U WS , heat consumption distillation unit U D , and heat consumption crystallization unit U C Equipped with U WS , U D , and U C At least a portion of the heat consumed by one or more of them is transferred to one or more streams S V It is provided by at least one of the following.

[0036] Preferably, this process consists of the following steps: - U WS From at least one at least partially condensed aqueous stream S VW1 Steps to obtain - U D From at least one at least partially condensed aqueous stream S VW2 Steps to obtain - U C From at least one at least partially condensed aqueous stream S VW3 Steps to obtain One or more of the following, more preferably at least two or more of the following, more preferably all of the following: This process involves one or more S VW1 S VW2 , and S VW3 Preferably two or more S VW1 S VW2 , and S VW3 , moreS VW1 S VW2 , and SVW3 , defined above as water treatment unit U W The process further includes the step of supplying to [the appropriate device / factory].

[0037] Preferably, Stream S RW At least one of U WS It is obtained from.

[0038] Preferably, purification unit U P This is the heat consumption water separation unit U WS , heat consumption distillation unit U D , and heat consumption crystallization unit U C This process may also include a concentration c SL Stream S containing ε-caprolactam L to U WS The steps of supplying to U WS From concentration c UWS Stream U containing ε-caprolactam WS Steps to obtain and Stream S UWS distillation unit U D The steps of supplying to U D From concentration c UD Stream S containing ε-caprolactam UD Steps to obtain and Stream S UD Crystallization unit U C The steps of supplying to U C From concentration c SCPL Stream S containing ε-caprolactam CPL The steps include obtaining, c SL <c UWS <c UD <c SCPL That is the case.

[0039] Preferably, water separation unit U WS This includes at least two heat-consuming water separation subunits U WS1 and U WS2 Preferably, two heat-consuming water separation subunits U are coupled in series. WS1 and U WS2 It may also be equipped with Stream S L UWS1 It is supplied to U WS1 and U WS2 At least a portion of the heat consumed by one or more of them is transferred to one or more streams S V It is provided by at least one of the following.

[0040] Preferably, the process may include one or more of the following, more preferably all of the following: - U WS1 From at least one at least partially condensed aqueous stream S VW11 Steps to obtain - U WS2 From at least one at least partially condensed aqueous stream S VW12 Steps to obtain.

[0041] Preferably, at least one aqueous stream S RW1 U WS1 Obtained from and at least one aqueous stream S RW2 U WS2 Obtained from, S RW1 and S RW2 At least one of the following, preferably S RW1 and S RW2 U W It is supplied to.

[0042] Preferably, evaporation unit U E The process comprises two or more evaporation subunits, and the process has at least two steam streams S V1 and S V2 Steps to obtain and steam stream S V1 The steps include passing the steam stream S to at least one heat consumption unit and passing it through to the steam stream S V2 The steps include passing the steam stream S to at least one heat consumption unit. V1 and S V2 They differ from each other in either pressure and / or temperature.

[0043] The present invention also, (i) A step of supplying a chemical raw material F comprising polyamide 6 and further comprising at least one further organic polymer compound, (ii) Liquid Aqueous Stream S W The steps of supplying, (iii) The raw material F supplied according to (i) is supplied to the stream S supplied according to (ii). W The mixture is mixed with the chemical reaction unit U R Within the structure, the depolymerization temperature T of polyamide 6. D and the depolymerization pressure p of polyamide 6 D The polyamide 6 containing U is subjected to depolymerization conditions, R Water-based Stream S E A step to obtain stream S E However, the step includes one or more degradation products of ε-caprolactam and at least one further organic polymer compound, (iv) A water stream S comprising at least a portion of water and at least a portion of at least one of one or more decomposition products R A step of generating the stream S R However, Stream S E In comparison, ε-caprolactam is depleted, step and Aqueous stream S obtained by a process including R or a part thereof, relating to the use as a recycled stream to increase the ε-caprolactam yield of the depolymerization of polyamide 6 by (iii).

[0044] Furthermore, the present invention also provides a method for increasing the ε-caprolactam yield of the depolymerization reaction of polyamide 6, comprising the following steps: (i) A step of supplying a chemical raw material F comprising polyamide 6 and further comprising at least one further organic polymer compound, (ii) Liquid Aqueous Stream S W The steps of supplying, (iii) The raw material F supplied according to (i) is supplied to the stream S supplied according to (ii).W The mixture is mixed with the chemical reaction unit U R Within the structure, the depolymerization temperature T of polyamide 6. D and the depolymerization pressure p of polyamide 6 D The polyamide 6 containing U is subjected to depolymerization conditions, R Water-based Stream S E A step to obtain stream S E However, the step includes one or more degradation products of ε-caprolactam and at least one further organic polymer compound, (iv) A water stream S comprising at least a portion of water and at least a portion of at least one of one or more decomposition products R A step of generating the stream S R However, Stream S E In comparison, ε-caprolactam is depleted, step, (v) Water-based Stream S W Water-based Stream S as part of R At least a portion of the chemical reaction unit U R The step of supplying and returning This includes methods.

[0045] Chemical raw materials and materials M jThe supply of each material may include an upstream sorting step. In this regard, for example, the collected waste, preferably textile waste and / or engineering plastic material, more preferably textile waste, can be spread on a conveyor, and this spreading can be carried out either manually or by machine. The spread waste is then subjected to sorting by either composition and / or color. Sorting can be carried out either manually or by optical methods. If carried out by optical methods, sorting preferably includes infrared sorting, more preferably near-infrared sorting and / or mid-infrared sorting. Optionally, the waste may be subjected to an appropriate metal removal step before sorting. If a metal removal step is carried out, ferrous elements are preferably separated, for example, by appropriate magnetic means, and / or non-ferrous elements are preferably separated, for example, by appropriate eddy current separation means. After the sorting, the resulting waste can be subjected to further processing, for example, cutting and / or grinding.

[0046] The present invention is further described by the following set of embodiments and combinations of embodiments arising from the dependencies and backreferences shown. In particular, it should be noted that in each example in which the scope of an embodiment is referred to, for example in the context of the term, for example, "the process described in any one of Embodiments 1 to 4", all embodiments within this scope are expressly disclosed to those skilled in the art, i.e., the wording of this term should be understood by those skilled in the art as synonymous with "the process described in any one of Embodiments 1, 2, 3, and 4". Furthermore, it should be explicitly noted that the following set of embodiments represents a well-structured portion of the general description directed toward preferred aspects of the present invention and therefore adequately supports, but does not represent, the claims of the present invention.

[0047] 1. A process for hydrolytically depolymerizing polyamide 6, (i) A step of supplying a chemical raw material F comprising polyamide 6 and further comprising at least one further organic polymer compound, (ii) Liquid Aqueous Stream S W The steps of supplying, (iii) Chemical raw material F supplied according to (i) to stream S supplied according to (ii) W The mixture is mixed with the chemical reaction unit U R Within the structure, the depolymerization temperature T of polyamide 6. D and the depolymerization pressure p of polyamide 6 D The polyamide 6 containing U is subjected to depolymerization conditions, R Water-based Stream S E A step to obtain stream S E However, the step includes one or more degradation products of ε-caprolactam and at least one further organic polymer compound, (iv) At least a portion of the water and stream S E Aqueous Stream S containing at least one portion of one or more degradation products contained in R A step of generating the stream S R However, Stream S E In comparison, ε-caprolactam is depleted (drastically reduced, depeated), step, (v) Water-based Stream S W Water-based Stream S as part of R At least a portion of the chemical reaction unit U R The step of supplying and returning A process that includes this.

[0048] 2. Stream S E The process of Embodiment 1, further comprising one or more of ε-caprolactam dimers and aminocaproic acid.

[0049] 3. The process of Embodiment 1 or 2, wherein the supply raw material F comprises one or more of the following: at least one further organic polymer compound comprising at least one polyamide 6.6; at least one semi-aromatic polyamide comprising one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer comprising two or more of the polymer compounds comprising statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and at least one rubber material comprising one or more of the natural rubber material and at least one synthetic rubber material.

[0050] 4. Any one of the processes in Embodiments 1 to 3, wherein the supply raw material F comprises polyamide 6 and at least one further organic polymer compound, in addition to one or more of at least one pigment material and at least one glass fiber material.

[0051] 5. Stream S R Preferably, stream S R Any one of the processes in Embodiments 1 to 4, wherein at least one of the one or more decomposition products contained comprises at least one amine, at least one ketone, at least one ether, at least one amide, and at least one alcohol, wherein the at least one amine preferably comprises at least one aliphatic amine and at least one aromatic amine, the at least one ketone preferably comprises at least one aliphatic ketone, the at least one ether preferably comprises at least one aliphatic ether, the at least one amide preferably comprises at least one aliphatic amide, and the at least one alcohol preferably comprises at least one aliphatic alcohol.

[0052] 6. Stream S R Preferably, stream S R At least one of the one or more degradation products contained in comprises one or more of aniline, 4-aminotoluene, 2,2-dimethoxy-3-methylbutane, 3,3-dimethoxypentane, dimethylacetamide, tripropylamine, 2-octanol, 2,2-dimethoxybutane, and cyclopentanone, wherein aniline is preferably Stream S R It is included in, preferably stream S R A process from any one of embodiments 1 to 5, comprising at least one of the one or more degradation products contained in.

[0053] 7. Stream S R However, any one of the processes from Embodiments 1 to 6, comprising one or more of ε-caprolactam, preferably N-ethylcaprolactam and 3-(2-oxazepan-1-yl)propanal.

[0054] 8. At least one further organic polymer compound contained in the supply material comprises at least one polyurethane, and Stream S E However, it includes one or more decomposition products of the at least one polyurethane, and Stream S R However, any one of the processes from Embodiments 1 to 7, comprising at least a portion of at least one of the one or more decomposition products.

[0055] 9. At least one of the polyurethanes contained in the supply raw material F is prepared from at least one aniline-based isocyanate, S R The process according to Embodiment 8, wherein one or more degradation products contained therein include aniline.

[0056] 10.(i) The chemical raw material F supplied according to the instructions for w chemical materials M j (where j=1..w and w≧1) and chemical material M jAt least one of the chemical materials M, preferably all of them j A process any one of Embodiments 1 to 9, wherein the process includes, preferably only, waste, wherein the waste preferably includes one or more of at least one textile waste and at least one engineering plastic waste, more preferably only, and more preferably includes, preferably only, at least one textile waste.

[0057] 11. Any one of the processes of Embodiments 1 to 10, wherein 10 to 100% by weight of the supply raw material F, preferably 20 to 100% by weight, more preferably 30 to 100% by weight, more preferably 40 to 100% by weight, more preferably 50 to 100% by weight, and more preferably 60 to 100% by weight consists of polyamide and at least one further organic polymer compound.

[0058] According to 12.(i), the process of any one of Embodiments 1 to 11 wherein the supply material F is supplied in solid form, preferably in the form of particles, and the particle size distribution of the particles is preferably characterized by one or more pairs of the following values, preferably two or more pairs of the following values, more preferably three pairs of the following values: - D10 values ​​for particle widths in the range of 0.3 to 15 mm and D10 values ​​for particle lengths in the range of 0.3 to 15 mm. - D50 values ​​for particle widths in the range of 0.5 to 20 mm and D50 values ​​for particle lengths in the range of 0.5 to 20 mm. - D90 values ​​for particle widths ranging from 0.8 to 30 mm and D90 values ​​for particle lengths ranging from 0.8 to 30 mm.

[0059] According to 13.(iii), the supplied raw material F is in solid form in aqueous stream S W The process of embodiment 12, which involves mixing with the other.

[0060] 14. The supply of the feed material F in accordance with (i) preferably includes the step of converting the feed material F from a solid form to a liquid form by subjecting the solid feed material F to melt extrusion, and in accordance with (iii), the feed material F in liquid form into an aqueous stream S W The process of embodiment 12, which involves mixing with the other.

[0061] According to 15.(iii), the depolymerization temperature T of polyamide 6 is D However, any one of the processes in Embodiments 1 to 14, wherein the temperature range is in the range of 230 to 330°C, preferably in the range of 250 to 320°C, and more preferably in the range of 270 to 310°C.

[0062] According to 16.(iii), the depolymerization pressure p of polyamide 6 D However, any one of the processes in Embodiments 1 to 15, wherein the pressure is in the range of 40 to 140 bar, preferably in the range of 40 to 125 bar, and more preferably in the range of 40 to 110 bar.

[0063] According to 17.(iii), the supply raw materials F and stream S W However, the mixing ratio (m) is in the range of 1:1 to 20:1, preferably in the range of 2:1 to 15:1, and more preferably in the range of 5:1 to 10:1. W (kg) / (m) P Mixed in m ( / kg), W S W This is the amount of water contained in m P A process in any one of embodiments 1 to 16, wherein the amount of polyamide 6 contained in F is [amount].

[0064] 18. Reaction Unit U R However, z chemical reactors R i A process comprising i=1...z, wherein z is in the range of 1 to 10, preferably 1 to 8, more preferably 1 to 6, more preferably 1 to 5, more preferably 1 to 4, and more preferably 1 to 3, any one of embodiments 1 to 17.

[0065] 19. If z > 1, then at least two reactors R i Preferably z reactors R i The process of embodiment 18, in which the two are coupled in series.

[0066] 20. Chemical Reaction Unit U R A process in any one of Embodiments 1 to 19, wherein the total residence time is in the range of 15 to 800 minutes, preferably in the range of 30 to 600 minutes, more preferably in the range of 45 to 360 minutes, and more preferably in the range of 60 to 240 minutes.

[0067] 21. Any one of the processes from Embodiments 1 to 20, which is a continuous process, a semi-continuous process, or a batch process.

[0068] 22.(iv) Aqueous Stream S R The reaction unit U generates R Stream S obtained from E Depending on the choice, S E After being subjected to filtration, it is subjected to hot water separation, and Stream S R A process any one of embodiments 1 to 21, which includes the step of obtaining

[0069] 23. The process of Embodiment 22, wherein the hot water separation includes one or more of distillation and drip membrane evaporation.

[0070] 24.(iv) Aqueous Stream S R The reaction unit U generates R Stream S obtained from E Depending on the choice, S E After being filtered, it is distilled and streamed. R A process which includes, preferably consists solely of, the step of obtaining one of the embodiments 1 to 23.

[0071] 25. Distillation is carried out in a distillation column at a bottom temperature in the range of 70 to 140°C, preferably 80 to 120°C, more preferably 90 to 110°C, and a top pressure in the range of 0.5 to 1.5 bar (abs), preferably 0.7 to 1.2 bar (abs), more preferably 0.8 to 1.1 bar (abs), and in stream S R The process of Embodiment 24, in which the product is obtained at the top of the distillation column.

[0072] 26. Distillation condenses the top vapor stream into a liquid stream S. R The step includes obtaining a liquid stream S R At least a portion of it is aqueous stream S according to (v). W Chemical reaction unit U as part of the chemical reaction unit R The process of embodiment 25, which is supplied and returned.

[0073] 27. Liquid stream S obtained by condensation R However, it is divided into two streams, and the first stream obtained from the division is the aqueous stream S according to (v). W Chemical reaction unit U as part of the chemical reaction unit R The process of Embodiment 26, wherein a second stream is supplied and returned to the top of the distillation column, and the volume ratio of the first stream to the second stream is preferably in the range of 10:1 to 0.5:1, more preferably in the range of 7:1 to 1:1, and more preferably in the range of 5:1 to 2:1.

[0074] 28.(iv) Aqueous Stream S R To generate (A) Liquid Aqueous Stream S E Evaporation unit U E Pass through to S E From, c SL >c SR The concentration c SL Aqueous aqueous Stream S containing ε-caprolactam dissolved in water L Having obtained S E From one or more water vapor streams S VSteps to obtain (B) Water-based Stream S L Heat consumption purification unit U P Pass through, S L From, c SCPL >>c SL The concentration c SCPL Stream S containing ε-caprolactam CPL Having obtained S L From one or more water-based stream S RW A step to obtain U P At least a portion of the heat consumed is used by one or more streams S V Provided by at least one of the following, thereby providing at least one stream S V From, at least one partially condensed aqueous stream S VW To obtain, steps, (C) Stream S R Therefore, at least partially, at least one stream S VW and at least partially at least one stream S RW reaction unit U R The steps to reuse (recycle) A process which includes any one of Embodiments 1 to 21.

[0075] 29. S obtained by the process of Embodiment 28 for preparing one or more polymers and polymer products CPL Use, or A method for preparing one or more polymers and polymer products, which can be obtained by the process of Embodiment 28 or obtained S CPL A method comprising the step of using as a starting material.

[0076] 30. Use or method of Embodiment 29, wherein the polymer, or polymer product, or polymer and polymer product is in the form of at least one of granules, strands, rods, plates, pipes, foil, layers, films, sheets, fibers, filaments, coatings, extruded articles, molded articles, flexible foams, semi-rigid foams, and rigid foams.

[0077] 31. A polymer, or polymer product, or polymer and polymer product comprising polyamide 6 and optionally, at least one further polymer compound, wherein the polyamide 6 is S CPL Obtained at least partially from or obtained from the S CPL Use or method of Embodiment 29 or 30, wherein the process of Embodiment 28 yields or obtains at least one further polymer compound, preferably comprising at least one polyamide 6.6; at least one semi-aromatic polyamide comprising one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer of two or more of the polymer compounds comprising statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and at least one rubber material comprising one or more of at least one natural rubber material and at least one synthetic rubber material.

[0078] 32. Use of any one of the methods of Embodiments 29 to 31, wherein the polymer, or polymer product, or polymer and polymer product is one of the following, or part of one of the following: - Parts of an automobile, preferably cylinder head covers, engine covers, intake radiator housings, intake radiator flaps, intake pipes, intake manifolds, connectors, gear wheels, fan wheels, coolant boxes, heat exchanger housings or housing components, coolant coolers, intake radiators, thermostats, water pumps, radiators, fastening components or parts of battery systems for electric transport, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, automotive exteriors for A, B, C or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protective housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights, taillights, airbags, and / or cushions; - Cloth, clothing, preferably shirts, trousers, pullovers, boots, shoes, soles, tights and / or jackets; - Electrical components, preferably electrical components, passive electronic components, active electronic components, printed circuit boards, housing components, foil, lines, switches, e.g., microswitches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, bobbins, lamps, diodes, e.g., LEDs, transistors, connectors, regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microbuttons, semiconductors, e.g., reflector housings for light-emitting diodes, fasteners, spacers, bolts, strips, slide-in guides, screws, nuts, film hinges, snap hooks (snap-ins), and / or spring tongues for electrical and / or electronic components; - Consumer and / or pharmaceutical products, preferably tennis strings, climbing ropes, bristols, brushes, artificial grass, 3D printing filaments, lawnmowers, zippers, hook-and-loop fasteners, paper machine garments, extruded coatings, fishing lines, fishing nets, seabed lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, plain bearings, rollers, wheels, gears, rollers, ring gears, screws and spring dampers, hoses, pipelines, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes and / or bottles, mattresses, cushions, insulation materials; - Packaging for the food industry, preferably single-layer and / or multi-layer inflated films, cast films (single-layer and / or multi-layer), biaxially oriented films, and laminate films.

[0079] 33. Polymers, or polymer products, or polymers and polymer products, S CPL The polyamide 6 obtained from or obtained from the S CPL However, the amount obtained or obtained by the process described in Embodiment 28 is any one of the uses or methods of Embodiments 29 to 32, which is 1% by weight or more, preferably 2% by weight or more, more preferably 5% by weight or more, more preferably 15% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 60% by weight or more, more preferably 80% by weight or more, more preferably 90% by weight or more, more preferably 95% by weight or more, and / or 100% by weight or less, preferably 95% by weight or less, more preferably 90% by weight or less, more preferably 50% by weight or less, more preferably 25% by weight or less, more preferably 10% by weight or less.

[0080] 34. (i) A step of supplying a chemical raw material F comprising polyamide 6 and further comprising at least one further organic polymer compound, (ii) Liquid Aqueous Stream S W The steps of supplying, (iii) The raw material F supplied according to (i) is supplied to the stream S supplied according to (ii). W The mixture is mixed with the chemical reaction unit U R Within the structure, the depolymerization temperature T of polyamide 6. D and the depolymerization pressure p of polyamide 6 D The polyamide 6 containing U is subjected to depolymerization conditions, R Water-based Stream S E A step to obtain stream S E However, the step includes one or more degradation products of ε-caprolactam and at least one further organic polymer compound, (iv) A water stream S comprising at least a portion of water and at least a portion of at least one of one or more decomposition products R A step of generating the stream S R However, Stream S E In comparison, ε-caprolactam is depleted (drastically reduced), and Aqueous stream S obtained by a process including R or a portion thereof, as a reuse (recycle) stream to increase the ε-caprolactam yield of the depolymerization of polyamide 6 in accordance with (iii).

[0081] 35. A method for increasing the ε-caprolactam yield of the depolymerization reaction of polyamide 6, (i) A step of supplying a chemical raw material F comprising polyamide 6 and further comprising at least one further organic polymer compound, (ii) Liquid Aqueous Stream S W The steps of supplying, (iii) The raw material F supplied according to (i) is supplied to the stream S supplied according to (ii). W The mixture is mixed with the chemical reaction unit U R Within the structure, the depolymerization temperature T of polyamide 6. D and the depolymerization pressure p of polyamide 6 D The polyamide 6 containing U is subjected to depolymerization conditions, RWater-based Stream S E A step to obtain stream S E However, the step includes one or more degradation products of ε-caprolactam and at least one further organic polymer compound, (iv) A water stream S comprising at least a portion of water and at least a portion of at least one of one or more decomposition products R A step of generating the stream S R However, Stream S E In comparison, ε-caprolactam is depleted (drastically reduced), step, (v) Water-based Stream S W Water-based Stream S as part of R At least a portion of the chemical reaction unit U R The step of supplying and returning Methods that include...

[0082] With respect to Embodiment 33, the respective amounts are preferably determined based on identity retention and / or separation and / or mass balance and / or book and claims management models, more preferably based on mass balance, and more preferably based on International Sustainability and Carbon Certification (ISCC) standards.

[0083] With respect to embodiments 29 to 33, the preparation of polymers, polymer products, or polymers and polymer products may involve one or more synthetic steps and can be carried out by conventional synthesis and techniques well known to those skilled in the art. Examples of synthetic steps are found in "Industrial Organic Chemistry," Vol. 3, Wiley-VCH, 1997; ISBN: 978-3-527-28838-0; "Kunststoffhandbuch," Vol. 11 of 17 sub-volumes, Carl Hanser Verlag, Vol. 6 in particular; "Polyamides," 1st edition, 1966; "Injection Molding Reference Guide, 4 thThis information is contained in the edition, "CreateSpace Independent Publishing Platform," 2011, ISBN: 978-1466407824; International Publication No. 2008 / 155271 and International Publication No. 2013 / 139827, which are incorporated herein by reference, respectively.

[0084] In the context of the present invention, the phrase "X is one or more of A, B, and C" should be understood as disclosing that X is either A, B, or C, or A and B, or A and C, or B and C, or A, B, and C. In this regard, those skilled in the art can translate the above abstract terms into concrete examples, for example, X is a chemical element and A, B, and C are specific elements, e.g., Li, Na, and K, or X is a temperature and A, B, and C are specific temperatures, e.g., 10°C, 20°C, and 30°C. In this regard, it should be noted that it is possible to extend the above terms to less specific realizations of the features, for example, "X is one or more of A and B" to disclose that X is either A, or B, or A and B, or for more specific realizations of the features, for example, "X is one or more of A, B, C, and D" to disclose that X is either A, or B, or C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C, or A and B and D, or B and C and D.

[0085] When used in the context of this invention, the term "bar" refers to "bar(abs)," that is, bar (absolute value), and is sometimes also referred to as "bara."

[0086] As used herein, the term “textile material” encompasses fibrous and non-textile raw materials processed into linear, planar, and spatial structures by various methods. This includes linear fibrous structures manufactured from fibrous materials, e.g., yarns, twisted yarns, and ropes; sheet-like fibrous structures, e.g., woven fabrics, knitted fabrics, braids, stitch-bonded fabrics, nonwoven fabrics, and felts; and three-dimensional fibrous structures, i.e., body structures, e.g., fibrous hoses, stockings, or fibrous semi-finished products; and further, finished products made from the aforementioned products that are assembled, opened up, and / or otherwise made ready for sale to processors, traders, or end consumers.

[0087] The term "textile waste" encompasses the textile materials defined above, whose inherent value has been consumed from the perspective of the current owner, and which are thus materials at the end of their lifespan for the said owner.

[0088] As used herein, the term “engineering plastics” refers to high-performance plastic grades that possess physical properties enabling them to be used in structural applications, over a wide temperature range, under mechanical stress, and for long-term use in challenging chemical and physical environments, for example, to manufacture plastic components as an alternative to conventional engineering materials such as metals and ceramics. Engineering plastics are particularly applicable to the manufacture of mechanical components across several industries, such as automotive, medical, electrical and electronic, aerospace, construction, and consumer products.

[0089] As used herein, the term “engineering plastic waste” encompasses the engineering plastic materials defined above, whose inherent value has been consumed from the perspective of the current owner, and which are thus materials that have reached the end of their lifespan for that owner.

[0090] Preferred embodiments of the present invention are further shown in Figure 1 and the examples below. [Brief explanation of the drawing]

[0091] [Figure 1] Figure 1 shows the experimental results from operations 1 to 10, as described in Table 2, particularly regarding the total yields of the caprolactam species (i) ε-caprolactam monomer, (ii) ε-caprolactam dimer, and (iii) aminocaproic acid. In Figure 1, the x-axis shows the number of operations for each operation, and the y-axis shows the corresponding total yield (%). Linear regression is included (dotted line), which further highlights the increase in yield over time. [Modes for carrying out the invention]

[0092] <Examples> A fiber waste M containing approximately 65% ​​by weight of polyamide 6, and further containing at least one additional organic polymer material including polyurethane prepared from an aniline-based isocyanate, was subjected to the depolymerization of polyamide 6 as a feed material F as follows: 1.2 kg of material M was supplied in the form of solid granules with a diameter ranging from 1 to 4 mm. This material was added to 10 kg of liquid aqueous phase S having the composition shown in the table below. W Along with, internal volume 20dm 3 Attach Autoclave U R The mixture was then placed in the autoclave. Next, the autoclave was closed and the granule / aqueous phase mixture was heated from ambient temperature to 270°C, the depolymerization temperature of polyamide T. D The mixtures were heated to a pressure of 55-60 bar (abs) for 2 to 4 hours. This temperature was maintained for a residence time of 140 minutes. The resulting depolymerization reaction mixtures S were then prepared. E The mixture was cooled to ambient temperature. E After draining from the autoclave, S E The mixture was filtered through a 50 μm sieve.

[0093] Next, the filtered solution S obtained... E The material was subjected to distillation in a distillation column at a bottom temperature of 106°C, a top temperature of 100°C, and a top pressure of 1013 mbar (abs). The vapor top stream obtained from the distillation column was condensed to obtain the liquid stream S. RDivide it into two streams, and add 25% by volume of S R Feed it to the top of the tower and return it, and add 75% by volume of S R In the next drive, S W As part of the autoclave U R It was supplied and returned as a supply to (reflux ratio 1:3). The raw material ε-caprolactam solution U R The bottom stream obtained from has a water content of approximately 30% by weight, an ε-caprolactam content of 4 to 5% by weight, an ε-caprolactam dimer content of 0.05 to 0.1% by weight, and an aminocaproic acid content of 0.9 to 1.4% by weight, and stream S R GC analysis revealed that it contained approximately 0.045% by weight of ε-caprolactam.

[0094] Liquid stream S obtained from the condensation described above R It contained the following compounds, as determined by GC analysis (average area content based on values ​​obtained from operations 1 to 10):

[0095] [Table 1]

[0096] According to the present invention, as described above, 75 volume% of S R S in the next operation W As part of the autoclave U R It was supplied and returned as a supply to [the source]. In this regard, 10 consecutive polyamide depolymerization reactions were carried out in an autoclave. In the first run, aqueous stream S W It consists of 10 kg of unused DI water, and the resulting product stream S E After filtration, the above distillation is performed, and the top vapor stream S from 75% by volume is obtained. R This results in the use of the aqueous Stream S in the second operation. W U as part of R It supplied and returned. Stream S was used for the second run. W The total mass of S was also 10 kg, WOnly a part of it consists of fresh water, and the rest consists of the above 75% by volume of S R As summarized in the following table, this procedure was repeated for the following operations 3 to 10. After the 10th operation, the process was stopped.

[0097] Furthermore, the following table shows the respective yields of ε-caprolactam species for each operation, and as far as these species are concerned, in addition to ε-caprolactam (monomer), ε-caprolactam dimer and aminocaproic acid are considered. The term "yield" as used in this context of the present invention, for each operation, is defined as the mass of each component contained in the stream S obtained in this operation divided by the mass of polyamide 6 contained in the material M used as the starting material for this operation. The following results were obtained: R as the mass of polyamide 6 contained in the material M used as the starting material for this operation. The following results were obtained:

[0098]

Table 2

[0099] As can be derived from the results shown in the above table further shown in FIG. 1, the total yield in all ε-caprolactam species, particularly the yield in ε-caprolactam monomer, increases statistically over time, i.e., the longer the process operation (more continuous operation is carried out), the higher the respective yields. This result obtained from the continuous batch operation is also a model of a continuous process, and therefore, essentially the same result (increase in yield) should be expected.

[0100] The GC analysis measurement according to the present invention was carried out as follows: The analysis was performed using a standard GC instrument equipped with a split / splitless injector and FID. The injection volume was 1 μL (microliter) with a split ratio of 15:1. The injector temperature was 250°C. The instrument was operated in constant pressure mode at 14.5 psi (approximately 1 bar), and nitrogen was used as the carrier gas. Separation was performed using an Agilent Technologies Wax 52 CB column, 50 m × 0.32 mm, 1.2 μm. The temperature program started with a gradient from 80°C to 185°C at a heating rate of 7°C / min and a retention time of 30 minutes at 185°C. The second gradient was from 185°C to 200°C at a heating rate of 7°C / min and a retention time of 5 minutes at 200°C. The detector (flame ionization detector, FID) temperature was 250°C. Purity values ​​were evaluated based on the area % distribution corrected for water content determined by the Carl Fisher method.

Claims

1. A process for depolymerizing polyamide 6 by hydrolysis, comprising the following steps: (i) A step of supplying a chemical raw material F which comprises the polyamide 6 and further comprises at least one further organic polymer compound, (ii) Liquid Aqueous Stream S Ｗ The steps of supplying, (iii) The chemical raw material F supplied according to (i) is supplied according to the stream S Ｗ The mixture is mixed with the chemical reaction unit U Ｒ Within the structure, the depolymerization temperature T of polyamide 6. Ｄ and the depolymerization pressure p of polyamide 6 Ｄ The polyamide 6 containing U is subjected to depolymerization conditions, Ｒ Water-based Stream S Ｅ A step to obtain the stream S Ｅ However, the step includes one or more degradation products of ε-caprolactam and the at least one further organic polymer compound, (iv) at least a part of the water and at least a part of at least one of the one or more decomposition products contained in the stream S Ｅ to generate an aqueous stream S containing at least a part of at least one of the one or more decomposition products contained in the stream S Ｒ wherein the stream S Ｒ has a sharp decrease in ε-caprolactam compared to the stream S Ｅ and a step, (v) The aqueous stream S Ｗ As part of the aqueous stream S Ｒ At least a portion of the chemical reaction unit U Ｒ The step of supplying and returning A process that includes this.

2. The aforementioned stream S Ｅ The process according to claim 1, further comprising one or more of ε-caprolactam dimer and aminocaproic acid.

3. The process according to claim 1 or 2, wherein the at least one further organic polymer compound contained in the supply raw material F comprises at least one polyamide 6.6; at least one semi-aromatic polyamide comprising one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer comprising two or more polymer compounds including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and at least one rubber material comprising one or more of at least one natural rubber material and at least one synthetic rubber material.

4. The aforementioned stream S Ｒ , more preferably the stream S Ｒ The process according to any one of claims 1 to 3, wherein at least one of the one or more decomposition products contained in comprises one or more of at least one amine, at least one ketone, at least one ether, at least one amide, and at least one alcohol, wherein the at least one amine preferably comprises one or more of at least one aliphatic amine and at least one aromatic amine, the at least one ketone preferably comprises at least one aliphatic ketone, the at least one ether preferably comprises at least one aliphatic ether, the at least one amide preferably comprises at least one aliphatic amide, and the at least one alcohol preferably comprises at least one aliphatic alcohol.

5. The aforementioned stream S Ｒ Preferably the stream S Ｒ At least one of the one or more decomposition products contained in is one or more of aniline, 4-aminotoluene, 2,2-dimethoxy-3-methylbutane, 3,3-dimethoxypentane, dimethylacetamide, tripropylamine, 2-octanol, 2,2-dimethoxybutane, and cyclopentanone, and aniline is preferably the stream S Ｒ Included in, preferably the stream S Ｒ The process according to any one of claims 1 to 4, wherein the process is contained in at least one of the one or more decomposition products contained in the above.

6. The aforementioned stream S Ｒ The process according to any one of claims 1 to 5, wherein the process comprises ε-caprolactam, and preferably one or more of N-ethylcaprolactam and 3-(2-oxazepan-1-yl)propanal.

7. The at least one further organic polymer compound contained in the supply material comprises at least one polyurethane, and the stream S Ｅ However, it includes one or more decomposition products of the at least one polyurethane, and the stream S Ｒ However, it contains at least a portion of at least one of the one or more decomposition products, and one or more of the at least one polyurethane contained in the supply raw material F is preferably prepared from at least one aniline-based isocyanate, and S Ｒ The process according to any one of claims 1 to 6, wherein the one or more decomposition products contained therein include aniline.

8. (i) The chemical raw material F supplied according to (i) is w of chemical materials M ｊ It consists of j = 1, w and w ≥ 1, and the chemical material M ｊ At least one of the chemical materials M, preferably all of them ｊ The process according to any one of claims 1 to 7, wherein the material includes, preferably only, waste, and the waste preferably includes, one or more of at least one fibrous waste and at least one engineering plastic waste, more preferably only, at least one fibrous waste, more preferably only, and preferably 10 to 100% by weight, more preferably 20 to 100% by weight, more preferably 30 to 100% by weight, more preferably 40 to 100% by weight, more preferably 50 to 100% by weight, and more preferably 60 to 100% by weight of the supply material F consists only of the polyamide and the at least one further organic polymer compound.

9. The supply raw material F is in solid form, and the aqueous stream S Ｗ Mixing according to (iii) or supplying the feed material F according to (i) includes the step of converting the feed material F from a solid to a liquid, preferably by subjecting the solid feed material F to melt extrusion, and according to (iii), the feed material F is in liquid form in the aqueous stream S Ｗ It is mixed with; According to (iii), the supply raw material F and the stream S Ｗ However, the mixing ratio (m) is preferably in the range of 1:1 to 20:1, more preferably in the range of 2:1 to 15:1, and more preferably in the range of 5:1 to 10:

1. Ｗ (kg) / (m) Ｐ It is mixed at a rate of / kg, where m Ｗ is S Ｗ This is the amount of water contained in, and m Ｐ The process according to claim 8, wherein is the amount of polyamide 6 contained in F.

10. According to (iii), the depolymerization temperature T of the polyamide 6 Ｄ However, the depolymerization pressure p of the polyamide 6 is in the range of 230 to 330°C, preferably in the range of 250 to 320°C, more preferably in the range of 270 to 310°C, and according to (iii), Ｄ However, the range is 40 to 140 bar, preferably 40 to 125 bar, more preferably 40 to 110 bar, and the chemical reaction unit U Ｒ The process according to any one of claims 1 to 9, wherein the total residence time within is in the range of 15 to 800 minutes, preferably in the range of 30 to 600 minutes, more preferably in the range of 45 to 360 minutes, and more preferably in the range of 60 to 240 minutes.

11. (iv) The aqueous stream S Ｒ The reaction unit U generates Ｒ The stream S obtained from Ｅ Depending on the choice, S Ｅ After being subjected to filtration, it is subjected to hot water separation, and the stream S Ｒ The process according to any one of claims 1 to 10, comprising the step of obtaining, wherein the thermal separation preferably comprises one or more of distillation and flowing film evaporation.

12. (iv) The aqueous stream S Ｒ The reaction unit U generates Ｒ The stream S obtained from Ｅ Depending on the choice, S Ｅ After being filtered, it is distilled and the stream S Ｒ The process includes the step of obtaining, where distillation is carried out in a distillation column at a bottom temperature preferably in the range of 70 to 140°C, more preferably in the range of 80 to 120°C, more preferably in the range of 90 to 110°C, and a top pressure preferably in the range of 0.5 to 1.5 bar (abs), more preferably in the range of 0.7 to 1.2 bar (abs), more preferably in the range of 0.8 to 1.1 bar (abs), and the stream S Ｒ However, obtained at the top of the distillation column, Distillation is preferably performed by subjecting the top vapor stream to condensation, thereby producing a liquid stream S Ｒ The step includes obtaining the liquid stream S Ｒ At least a portion of the aqueous stream S according to (v) Ｗ As part of the chemical reaction unit U Ｒ The liquid stream S is supplied and returned, and obtained by condensation. Ｒ However, by optional selection, it may be divided into two streams, and the first stream obtained by the division is the aqueous stream S according to (v). Ｗ As part of the chemical reaction unit U Ｒ The process according to any one of claims 1 to 10, wherein a second stream is supplied back to the top of the distillation column, and the volume ratio of the first stream to the second stream is preferably in the range of 10:1 to 0.5:1, more preferably in the range of 7:1 to 1:1, and more preferably in the range of 5:1 to 2:

1.

13. (iv) The aqueous stream S Ｒ To generate it, follow these steps: (A) The liquid aqueous stream S Ｅ Evaporation unit U Ｅ Pass it through to S Ｅ From, c ＳＬ > c ＳＲ The concentration c ＳＬ Aqueous Stream S containing ε-caprolactam dissolved in water Ｌ Having obtained S Ｅ From one or more water vapor streams S Ｖ Steps to obtain, (B) The aqueous stream S Ｌ Heat consumption purification unit U Ｐ Pass through, S Ｌ From, c ＳＣＰＬ >>c ＳＬ The concentration c ＳＣＰＬ Stream S containing ε-caprolactam ＣＰＬ Having obtained S Ｌ From one or more Aqueous Stream S ＲＷ A step to obtain U Ｐ At least a portion of the heat consumed is used in the one or more streams S Ｖ It is brought about by at least one of the at least one stream S Ｖ From, at least one at least partially condensed aqueous stream S ＶＷ To obtain, steps, (C) The stream S Ｒ Therefore, at least one stream S ＶＷ at least partially, and at least one stream S ＲＷ at least partially, the reaction unit U Ｒ The recycling steps The process according to any one of claims 1 to 10, including the process described in any one of claims 1 to 10.

14. S obtained by the process according to claim 13 for preparing one or more polymers and polymer products ＣＰＬ The use of the polymer, or the polymer product, or the polymer and the polymer product is in the form of at least one of granules, strands, rods, plates, pipes, foils, layers, films, sheets, fibers, filaments, coatings, extruded articles, molded articles, flexible foams, semi-rigid foams, and rigid foams, wherein the polymer, or the polymer product, or the polymer and the polymer product comprises polyamide 6 and optionally, in some cases, at least one further polymer compound, and the polyamide 6 is at least partially S ＣＰＬ Obtained from or obtained from the S ＣＰＬ The process described in claim 13 is obtained or obtained such that the at least one further polymer compound preferably comprises at least one polyamide 6.6; at least one semi-aromatic polyamide comprising one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer of two or more of the polymer compounds comprising statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and one or more of at least one rubber material comprising one or more of at least one natural rubber material and at least one synthetic rubber material. The polymer, or the polymer product, or the polymer and the polymer product, preferably one of the following, or part of one of the following, for use: - Parts of an automobile, preferably cylinder head cover, engine cover, intake radiator housing, intake radiator flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, coolant box, heat exchanger housing or housing components, coolant cooler, intake radiator, thermostat, water pump, radiator, fastening components or parts of battery system for electric transport, dashboard, steering column switch, seat, headrest, center console, transmission components, door module, automobile exterior for A, B, C or D pillar cover, spoiler, door handle, exterior mirror, windshield wiper, windshield wiper protective housing, decorative grille, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight, taillight, airbag, and / or cushion; - Cloth, clothing, preferably shirts, trousers, pullovers, boots, shoes, soles, tights and / or jackets; - Electrical components, preferably electrical components, passive electronic components, active electronic components, printed circuit boards, housing components, wheels, lines, switches, e.g., microswitches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, bobbins, lamps, diodes, e.g., LEDs, transistors, connectors, regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microbuttons, semiconductors, e.g., reflector housings for light-emitting diodes, fasteners, spacers, bolts, strips, slide-in guides, screws, nuts, film hinges, snap hooks (snap-ins), and / or spring tongues for electrical and / or electronic components; - Consumer and / or pharmaceutical products, preferably tennis strings, climbing ropes, bristols, brushes, artificial grass, 3D printing filaments, lawnmowers, zippers, hook-and-loop fasteners, paper machine garments, extruded coatings, fishing lines, fishing nets, seabed lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, plain bearings, rollers, wheels, gears, rollers, ring gears, screws and spring dampers, hoses, pipelines, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes and / or bottles, mattresses, cushions, insulation materials; - Packaging for the food industry, preferably single-layer and / or multi-layer inflated films, cast films (single-layer and / or multi-layer), biaxially oriented films, and laminate films.

15. The following steps: (i) A step of supplying a chemical raw material F which contains polyamide 6 and further contains at least one further organic polymer compound, (ii) Liquid Aqueous Stream S Ｗ The steps of supplying, (iii) The feedstock F supplied according to (i) and the stream S supplied according to (ii) Ｗ are mixed, and the resulting mixture is fed into a chemical reaction unit U Ｒ wherein, at a depolymerization temperature T of polyamide 6 Ｄ and a depolymerization pressure p of polyamide 6 Ｄ the depolymerization conditions of polyamide 6 are applied, and an aqueous stream S Ｒ exiting from U is obtained, the stream S Ｅ containing one or more decomposition products of one or more of ε-caprolactam and said at least one further organic polymer compound, which step Ｅ is a step. (iv) generating an aqueous stream S comprising at least a portion of said water and at least a portion of at least one of said one or more decomposition products Ｒ wherein said stream S Ｒ is The aforementioned stream S Ｅ Compared to that, ε-caprolactam has been drastically reduced, step and Aqueous stream S obtained by a process including or obtained by a process including Ｒ or a portion thereof, used as a reuse stream to increase the ε-caprolactam yield of the depolymerization of polyamide 6 according to (iii).

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