Process for the preparation of an after-treatment agent for textile fibres and its use

Abstract

The invention relates to a process for the preparation of an after-treatment agent for textile fibres using an extract obtained from polyphenols from at least one plant component, the compound obtained according to the process and its use.

Description

[0001] Process for producing a post-treatment agent for textile fibers and its use

[0002] The invention relates to a process for producing a post-treatment agent for textile fibers using an extract of polyphenols from at least one plant component, the compound obtained by the process and its use.

[0003] Polyamide is a synthetic fiber primarily used in the clothing sector, especially underwear, sporting goods, and swimwear, as well as in technical applications. Forms of packaging include flock, yarn, and textile fabrics. In addition to pure polyamide, elastic fabrics, such as blends of polyamide 6.6 and elastane, are increasingly being used in textile fabrics.

[0004] Depending on the material composition, the finishing process, and the dye selection, the required wear fastness must be achieved. Fastness of textiles and their colors refers to their durability, including lightfastness. The required wear fastness can be wash fastness (e.g., at 50°C), contact fastness (water fastness and / or perspiration fastness), and / or even chlorine bath water fastness.

[0005] Fastness to wear is achieved through post-treatment or dye fixation of the fibers. Polyamide microfibers blended with elastane, in particular, require a targeted selection of post-treatment methods using anionic and / or cationic textile auxiliaries.

[0006] DE 25 07 108 A1 describes a fixing agent for improving the fastness properties of dyeings on polyamide fibers, in particular a condensation product of 4,4-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfonic acid and a lower aliphatic aldehyde, such as formaldehyde or acetaldehyde, or its metal salt, wherein the condensation product has an average molecular weight of about 5000 to about 30,000 and a ratio of the carbon atom content to the sulfur atom content of 3.0:1 to 4.8:1.

[0007] Traditionally, post-treatment is carried out with syntans, i.e., synthetic tannins. Syntan is produced by condensing phenol or bisphenol with formaldehyde. The synthesis of the products available on the market in recent decades was generally carried out via acid catalysis (novolak) or base catalysis (resol). DE 699 33 752 T2 discloses phenol novolaks with improved optical properties, in particular phenol-glyoxal condensates, glycidylated derivatives thereof, compositions containing them, and a process for their preparation, wherein glyoxal and phenol are condensed at a temperature of 80 to 100°C in the presence of 1 to 6% of an acid catalyst.

[0008] The disadvantage of novolak and resol products is that they are generally not water-soluble. A prerequisite for textile applications is products that are emulsified or completely soluble in water. Therefore, additional functionalization to increase solubility through a sulfonation reaction is necessary.

[0009] Due to the increasingly regulated use of phenols, bisphenols and also formaldehyde in textiles, there is a demand for phenol-, bisphenol- and formaldehyde-free products, which cannot be met by syntans.

[0010] Alternatively, natural substances such as tannins can be used. While these natural substances, especially tannins, meet the demand for phenol-, bisphenol-, and formaldehyde-free products and are therefore preferred for improving chlorine bath water fastness, they exhibit weaknesses in contact fastness and long-term effectiveness (declining effectiveness).

[0011] KR 10 2003 0010802 A discloses the use of about 0.1 to 5.0 wt.% of an inorganic, acidic iron salt, in particular iron(II) sulfate or iron(II) chloride, and subsequently 0.5 to 5.0 wt.% tannic acid or synthetic tannic acid as color fastness improvers for dyed polyamide fibers.

[0012] DE 3 621 410 A1 describes a post-treatment of dyed textile materials made of synthetic polyamides to improve the waterfastness of the dyeings by means of (A) 2 to 6 wt.% polyhydroxyphenol or a derivative thereof and subsequently with (B) 0.5 to 3 wt.% of a cationic condensation product obtained by reacting (a) piperazine and derivatives of piperazine with (b) bifunctional crosslinkers, such as ethyl halohydrin, in a molar ratio of 1:0.5 to 1:1 and quaternizing the condensation products with benzyl chloride, wherein 0.15-1.5 mol of benzyl chloride is used per equivalent of nitrogen in component (a) during the quaternization. Arbenz and Averous describe the extraction and purification as well as chemical modification of tannins (Arbenz and Averous 2015). The chemical modification includes the reaction of the heterocycle, the nucleophilic reaction sites and the hydroxyl groups.Arbenz and Averous disclose the reaction of the nucleophilic reaction sites of tannins with formaldehyde using an OH catalyst for the production of adhesives or foam production.

[0013] WO 2011 / 001 105 A1 describes a composite material based on fibers and natural resins, a manufacturing process and its use, in particular a natural composite comprising a reinforcement based on nonwovens made of natural fibers or fibers derived from biomass, selected from the group consisting of: plant fibers or cellulose fibers from biomass, such as viscose fibers; and a natural matrix selected from mixtures of tannins and lignin with low molecular weight, reacted with an aldehyde, in a weight proportion between 100 / 0 and 30 / 70 of the total weight of the solids, the resin accounting for between 20 and 50 wt% of the total weight, wherein the use of 30% sodium hydroxide and the maintenance of a pH between 12 and 12.5 is described for the pre-reaction.

[0014] The aim is therefore to provide a post-treatment agent for polyamide fibers which is free of phenol, bisphenol and formaldehyde and preferably improves the fastness level after the treatment of polyamide fibers.

[0015] According to the invention, this object is achieved by a method and a connection according to the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

[0016] According to a first aspect of the invention, the object is achieved by a process for producing a post-treatment agent for textile fibers, comprising the following steps: a) providing an extract of polyphenols from at least one plant constituent, b) dissolving the polyphenol extract in water, c) acid-catalyzed condensation of the polyphenols with at least one C2 to C10 aldehyde, wherein an organic or inorganic acid with a pKa value below 5 is used as the acid catalyst, wherein the acid catalyst is used in a proportion in the range of 0.01 wt.% to 2 wt.%. Advantageously, the process according to the invention enables the provision of a post-treatment agent for textile fibers which is obtained from plant constituents and is free of bisphenols, phenols, and formaldehyde.

[0017] Another advantage is that the acid-catalyzed condensation in step c) is endothermic, which makes the reaction easy to control even on an industrial scale. In comparison, the acid-catalyzed condensation of phenol with formaldehyde (novolak) is exothermic.

[0018] An extract is understood to be a substance or a mixture of substances which is separated from a plant component by means of a (solid, liquid or gaseous) extraction agent, preferably by means of a solvent, in particular water and / or an organic solvent.

[0019] In some embodiments, the extract contains constituents of the plant component that have been extracted from the plant component by means of aqueous and / or organic solvents. Various extraction methods are known to those skilled in the art. For example, Arbenz and Averous describe the extraction and purification of tannins (Arbenz and Averous 2015).

[0020] In embodiments, the extract is a fluid extract, thick extract and / or dry extract.

[0021] A “dry extract” (also total extract) is understood to mean an extract which comprises substances of at least one plant component which remain after distillation of the extract.

[0022] In preferred embodiments, the extract of polyphenols is a dry extract.

[0023] In embodiments, the extract of polyphenols has a solids content in the range of 85 wt% to 100 wt%.

[0024] In embodiments, the polyphenols are selected from tannins, lignin, lignin derivatives and / or cardanol.

[0025] In embodiments, lignin derivatives are salts of lignin, preferably sodium lignosulfonate or ammonium lignosulfonate. In preferred embodiments, the polyphenols are selected from hydrolyzable tannins, especially tannic acids.

[0026] “Tannin acids” are understood to mean polyphenolic tannins which have weakly acidic properties, in particular an ester or a mixture of esters of glucose with gallic acid and / or 3-galloylgallic acid (polygalloyl glucose).

[0027] In embodiments, the tannic acid has a number-average molecular weight in the range of 1,350 g / mol to 1,450 g / mol. The "number-average molecular weight" refers to the molecular weight of the polymer, weighted by the relative number fraction of this polymer.

[0028] In embodiments, the tannic acid has a mass-average molecular weight in the range of 1,400 g / mol to 1,500 g / mol. The "mass-average molecular weight" is understood to be the molecular weight of the polymer, weighted according to the relative mass fraction of this polymer.

[0029] In embodiments, the extract of polyphenols has a moisture content in the range of 0 wt% to 15 wt%, preferably 5 wt% to 10 wt%.

[0030] In embodiments, plant components are fresh, composted, frozen and / or dried plant material with or without residual moisture.

[0031] In some embodiments, the extracts are obtained from the above-ground parts of the plant, such as fruits, leaves, wood and / or bark.

[0032] In some embodiments, the extracts are obtained from residues from plant processing.

[0033] In embodiments, the tannins are extracted from bloodroot, hops, black tea, green tea, grapes, preferably their fruits; the divi-divi tree, the persimmon tree, the myrobalan, sumac plants, the trillo, the valonea, the pine, the mimosa, the oak, the chestnut or the acacia, preferably bark, wood and / or plant galls of oak, chestnut or acacia.

[0034] In embodiments, the extract comprises polyphenols with a content of 10 wt.% to 45 wt.%, preferably in the range of 10 wt.% to 40 wt.%, particularly preferably in the range of 10 wt.% to 35 wt.% The polyphenol content can be determined by means of Fourier transform infrared spectrometer (FTIR) or redox titration, in particular by means of colorimetric determination of the dry substance, for example by means of Folin-Ciocalteu reagent or Phenolfix test.

[0035] In embodiments, the extract is an aqueous and / or organic extract of the at least one plant component.

[0036] In embodiments, the extraction of the polyphenols comprises comminuting and / or homogenizing the at least one plant component.

[0037] In embodiments, the extraction of the polyphenols comprises the following steps: i. an extraction of the at least one plant component with water and ii. an extraction of the aqueous extract with a solvent mixture comprising diethyl ether and ethanol, preferably in a ratio of 1:4.

[0038] In embodiments, the extraction of the polyphenols further comprises separating the organic phase and evaporating the solvent.

[0039] In embodiments, the extraction of the polyphenols comprises at least one filtration and / or distillation.

[0040] In embodiments, step b) takes place at a temperature in the range of 20°C to 100°C, preferably in the range of 30°C to 90°C, particularly preferably in the range of 40°C to 80°C.

[0041] According to the invention, in step c) the acid catalyst used is an organic or inorganic acid with a pK a -value below 5 is used.

[0042] In embodiments, oxalic acid, monochloroacetic acid or sulfuric acid, preferably oxalic acid, is used as the acid catalyst in step c).

[0043] According to the invention, in step c) the acid catalyst is used in a proportion in the range from 0.01 wt.% to 2 wt.%, preferably in the range from 0.1 wt.% to 0.5 wt.%.

[0044] In embodiments, step c) takes place at a pH in the range from 0.5 to 3, preferably in the range from 1 to 2.5. According to the invention, in step c), the condensation takes place with at least one C2 to C10 aldehyde. A C2 to C10 aldehyde is understood to mean an aldehyde with at least one aldehyde group, preferably one or two aldehyde groups, which has two to ten carbon atoms in the empirical formula. The aldehyde is preferably a C2 to C6 aldehyde.

[0045] In embodiments, the aldehyde in step c) is glyoxal, 5-hydroxymethylfurfural or glutaraldehyde.

[0046] In preferred embodiments, the aldehyde in step c) is glyoxal.

[0047] In embodiments, in step c) the stoichiometric ratio of polyphenol to O2- to O10-aldehyde or OH group to aldehyde group is in the range from 1:0.4 to 1:2, ie 0.4 to 2 aldehyde groups are used for one OH group. Preferably, the stoichiometric ratio of polyphenol to O2- to O10-aldehyde is in the range from 1:0.4 to 1:0.8, particularly preferably in the range from 1:0.5 to 1:0.7.

[0048] In embodiments, step c) takes place at a temperature in the range of 90°C to 120°C, preferably in the range of 95°C to 105°C.

[0049] In embodiments, step c) takes place under an inert gas atmosphere, preferably a nitrogen atmosphere.

[0050] In embodiments, step c) is carried out for a duration in the range of 2.5 h to 5 h, preferably about 4 h.

[0051] In embodiments, the process according to the invention further comprises a finishing of the resulting compound after step c). "Finishing" is understood to mean the adjustment of properties for use as a post-treatment agent for textile fibers.

[0052] In embodiments, the process according to the invention comprises adjusting the viscosity after step c). In embodiments, the viscosity is adjusted by adding glycerol, propylene glycol, 2,3-O-isopropylidene glycerol, butyl glycol, and / or butyl diglycol. In embodiments, the viscosity is adjusted by adding glycerol, propylene glycol, 2,3-O-isopropylidene glycerol, butyl glycol, and / or butyl diglycol in a range of 4 wt.% to 12 wt.%, preferably in a range of 8 wt.% to 10 wt.%. In further embodiments, the process according to the invention comprises adjusting the pH after step c).

[0053] In embodiments, the process according to the invention further comprises adding the extract of polyphenols from at least one plant component after step c). In embodiments, the amount of extract of polyphenols from at least one plant component added after step c) is in the range of 10 wt.% to 15 wt.%.

[0054] Advantageously, the extract of polyphenols from at least one plant component in the aftertreatment agent can reduce and / or prevent yellowing and / or greying of the polyamide, wool and / or silk fibres.

[0055] A further aspect of the invention is a compound obtainable by the process according to the invention.

[0056] In embodiments, the compound obtainable by the process according to the invention has a viscosity in the range of at most 200 mPa s at a temperature of 20°C, preferably a viscosity in the range of 100 mPa s to 200 mPa s. The viscosity can be determined using a rheometer or viscometer, in particular with a rotational viscometer, for example from Brookfield®.

[0057] In embodiments, the compound obtainable by the process according to the invention has a solids content in the range of 26 wt.% to 40 wt.%, preferably 37 wt.% to 39 wt.%.

[0058] According to the invention, the compound obtainable by the process according to the invention has a pH in the range from 2 to 5, preferably 3 to 4.

[0059] Another aspect of the invention is the use of the compound according to the invention as a post-treatment agent and / or reserving agent for textile fibers, preferably polyamide, wool, silk fibers and / or mixtures thereof, in particular a treatment to increase wash fastness, chlorine bath water fastness and / or contact fastness.

[0060] The available post-treatment agent advantageously improves the washfastness, chlorine bath water fastness, and / or contact fastness of polyamide fibers and their blends, particularly polyamide-polyurethane blends, e.g., polyamide-elastane blends, as well as improving the fastness of wool and silk fibers. Furthermore, the available post-treatment agent advantageously exhibits acid stability and / or the absence of an "aging" effect.

[0061] The fastness of textiles and their colours refers to the resistance of textiles to various factors, such as light, skin contact or chlorinated bath water, including lightfastness, contact fastness or fastness to chlorinated bath water.

[0062] In embodiments, the polyamide fiber is a pure fiber or a mixed fiber.

[0063] In embodiments, the polyamide blend or polyamide blend fiber is a polyamide-wool blend fiber, a polyamide-cellulose blend fiber or a polyamide-polyurethane blend fiber, in particular a polyamide-elastane blend fiber.

[0064] In embodiments, the polyamide fiber is selected from polyamide 6.6 or a polyamide 6.6-elastane blend fiber, in particular 90% polyamide 6.6 microfiber / 10% elastane or 86% polyamide 6.6 / 14% elastane.

[0065] In embodiments, the compound according to the invention is used as a post-treatment agent for wool and / or silk fibers dyed with acid or metal complex dyes. The compound according to the invention advantageously improves the fastness of wool and / or silk fibers dyed with acid or metal complex dyes.

[0066] In embodiments, the compound according to the invention is used as a post-treatment agent for polyamide / wool and / or polyamide / silk blends which have been dyed with acid or metal complex dyes.

[0067] In embodiments, the compound according to the invention is used as a reserving agent for polyamide / wool blends which are subsequently dyed with acid or metal complex dyes.

[0068] In embodiments, the compound according to the invention is used as a reserving agent for polyamide / cellulose blends that are subsequently dyed with direct or reactive dyes. A fiber component is reserved, i.e., blocked, for dye absorption in accordance with the use concentration of the compound according to the invention.

[0069] The invention is not limited to the embodiments illustrated and described, but also encompasses all embodiments having the same effect within the meaning of the invention. Furthermore, the invention is not limited to the specifically described combinations of features, but can also be defined by any other combination of specific features of all the individual features disclosed as a whole, provided that the individual features are not mutually exclusive or a specific combination of individual features is not explicitly excluded.

[0070] In the following, the invention will be explained in more detail using exemplary embodiments and will describe the invention without limiting it.

[0071] Extraction of polyphenols from at least one plant component

[0072] The plant components, such as plant galls, are first crushed and extracted with water. The aqueous extract is then subjected to extraction with a solvent mixture of diethyl ether and ethanol in a ratio of 1:4. The organic phase is separated, and the aqueous solution is evaporated to dryness. The resulting polyphenol extracts are yellow-brown solids.

[0073] Inventive process for producing a post-treatment agent for polyamide

[0074] Example 1:

[0075] A polyphenol extract with a tannic acid content in the range of 22 to 35 wt.% is reacted with 1) glyoxal, 2) glutaraldehyde or 3) 5-hydroxymethylfurfural (5-HMF) in a stoichiometric ratio of 1:1, 1:0.8, 1:0.6 or 1:0.4. The polyphenol extract is first dissolved in water at 60°C. The reaction takes place under acid catalysis. For this purpose, 0.25 wt.% oxalic acid is added to the reaction mixture. The aldehyde is then added for condensation. Condensation takes place at a temperature of approximately 100°C over a period of 4 hours. The reaction mixture is then cooled to room temperature and approximately 4 to 6 wt.% each of glycerol and 1,2-propylene glycol are added to adjust the viscosity.

[0076] Example 2: A polyphenol extract with a tannic acid content in the range of 10 to 15 wt.% is reacted in a stoichiometric ratio of 1:1, 1:0.8, 1:0.6 or 1:0.4 with 1) glyoxal, 2) glutaraldehyde or 3) 5-HMF. The polyphenol extract is first dissolved in water at 60°C. The reaction takes place under acid catalysis. For this purpose, 0.25 wt.% oxalic acid is added to the reaction mixture. The aldehyde is then added for condensation. Condensation takes place at a temperature of approximately 100°C over a period of 4 hours. After cooling to 60°C, a further amount of polyphenol extract (10 to 15 wt.%) is added to the product in a second partial step. The reaction mixture is then cooled to room temperature. For formulation and viscosity adjustment, approximately 4 to 6 wt.% of glycerol and 1,2-propylene glycol are added to the reaction mixture.

[0077] Example 3:

[0078] A polyphenol extract with a tannic acid content in the range of 10 to 15 wt.% is mixed with sodium lignosulfonate or, alternatively, ammonium lignosulfonate in a stoichiometric ratio of 1:1 and reacted with 1) glyoxal, 2) glutaraldehyde, or 3) 5-HMF in a ratio of 1:1, 1:0.8, 1:0.6, or 1:0.4. The polyphenol extract and the lignin derivative are first dissolved in water at 60°C. The reaction takes place under acid catalysis. For this purpose, 0.25 wt.% oxalic acid is added to the reaction mixture. The aldehyde is then added for condensation. Condensation takes place at a temperature of approximately 120°C over a period of 4 hours. The reaction mixture is then cooled to room temperature and approximately 4 to 6 wt.% of glycerol and 1,2-propylene glycol are added to the reaction mixture to adjust the viscosity.

[0079] Example 4:

[0080] Sodium lignosulfonate or alternatively ammonium lignosulfonate with a polyphenol content in the range of 22 to 35 wt.% is reacted in a stoichiometric ratio of 1:1, 1:0.8, 1:0.6 or 1:0.4 with 1) glyoxal, 2) glutaraldehyde or 3) 5-HMF. The lignin derivative is first dissolved in water at 60°C. The reaction takes place under acid catalysis. For this purpose, 0.25 wt.% oxalic acid is added to the reaction mixture. The aldehyde is then added for condensation. Condensation takes place at a temperature of approximately 120°C over a period of 4 hours. The reaction mixture is then cooled to room temperature and approximately 4 to 6 wt.% each of glycerol and 1,2-propylene glycol are added to the reaction mixture to adjust the viscosity.

[0081] Example 5: A cardanol extract from the cashew nut shell with a polyphenol content in the range of 22 to 35 wt.% is reacted with 1) glyoxal, 2) glutaraldehyde or 3) 5-HMF in a ratio of 1:1, 1:0.8, 1:0.6 or 1:0.4. The cardanol extract is dissolved in water at 60°C. The reaction takes place under acid catalysis. For this purpose, 0.25 wt.% oxalic acid is added to the reaction mixture. The aldehyde is then added for condensation. Condensation takes place at a temperature of approximately 120°C over a period of 4 hours. The reaction mixture is then cooled to room temperature and, to prepare the mixture and adjust the viscosity, approximately 4 to 6 wt.% each of glycerol and 1,2-propylene glycol are added to the reaction mixture.

[0082] Characterization of the obtained post-treatment agent for polyamide

[0083] Post-treatment for polyamide:

[0084] Any dye post-treatment improves the wetfastness of dyeings made with acid or metal complex dyes. This post-treatment is particularly useful for medium and dark shades and / or for special requirements, such as fastness to chlorine bath water.

[0085] The anionic dye post-treatment is typically performed on polyamide 6.6 (nylon) at 75°C with an average treatment time of 20 minutes in an acidic pH range, particularly at a pH of 4 to 4.5. The amount of post-treatment agent varies depending on the required fastness level, the strength of the post-treatment agent, and the dye or dyestuff used. It is applied using the exhaust method in % (x% of the post-treatment agent based on the weight of the dyed textile).

[0086] Deviations regarding temperature occur with other polyamide types (e.g., polyamide 6) or special dyes such as Rhodamine (bright pink) and Flavin (bright yellow). Here, the temperature and / or pH range are varied.

[0087] After the post-treatment, the textile is rinsed thoroughly and subjected to further treatment according to the requirements profile (e.g. finishing, a treatment of threads and yarns made of chemical fibers with fatty substances to improve feel, softness and suppleness).

[0088] Example 1: Improvement of wash fastness at 60°C of a "Navy" dyeing (acid dye 3.6% Sellanyl Navy Blue N-5R 180%) on 100% PA 6.6 knitwear. 100% polyamide 6.6 (knitwear) was dyed with the dye under standard conditions, rinsed, and then post-treated in a fresh bath as follows: pH adjustment to pH 4 (with acetic acid 60%), addition of the post-treatment agent in various amounts, treatment at 75°C for 20 min, rinsing at 40°C for 10 min, rinsing at 20°C for 10 min, drying, wash fastness test at 60°C according to ISO 105-C03, evaluation of the staining of the multi-fiber accompanying fabric section polyamide using a gray scale (1 - very poor, strong staining, to 5 - very good, no staining) and calculation of the mean value. from evaluations by 3 test subjects, whereby the color change caused by the respective post-treatment agent or process was also evaluated.

[0089] Tab. 1 Results of post-treatment and evaluation of wash fastness of a “Navy” dyeing (acid dye 3.6% Sellanyl Navy Blue N-5R 180%) on 100% PA 6.6 knitwear.

[0090] Tab. 2 Results of post-treatment and evaluation of wash fastness of a navy dye (acid dye 3.6% Sellanyl Navy Blue N-5R 180%) on 100% PA 6.6 knitwear.

[0091] Example 2: Improvement of wet fastness at 40°C, especially wash fastness according to ISO 105-C06 A2S, water fastness severe according to ISO 105-E01 and perspiration fastness alkaline according to ISO 105-E04 of a “Wild Mallow” dyeing (1.5 acid dyes 1% Erionyl Red A3B + 0.5% Erionyl Bordeaux A5B) on 90% Polyamide 6.6 / 10% Elastane

[0092] 90% polyamide 6.6 microfiber / 10% elastane (pre-fixed knitwear) was dyed under standard conditions with the dyes 1% Erionyl Red A3B + 0.5% Erionyl Bordeaux A5B, rinsed and then after-treated in a fresh bath as follows: pH adjustment to pH 4 (with acetic acid 60%), addition of the after-treatment agent 3% each, treatment at 75°C for 20 min, rinsing at 40°C for 10 min, rinsing at 20°C for 10 min, drying, test of wash fastness at 40°C according to ISO 105-C06 A2S, water fastness severe according to ISO 105-E01, perspiration fastness alkaline according to ISO 105-E04, in each case evaluation of the bleeding of the multi-fiber accompanying fabric section polyamide using a grey scale (1 - very poor, heavy bleeding, to 5 - very good, no bleeding). Bleeding) and calculation of the mean value from evaluations by 3 test subjects, whereby the change in colour tone caused by the respective post-treatment agent or by the process was also assessed.

[0093] Tab. 3 Results of post-treatment and evaluation of wash fastness of a “Wild Mallow” dyeing (1.5 acid dyes 1% Erionyl Red A3B + 0.5% Erionyl Bordeaux A5B) on 90% Polyamide 6.6 / 10% Elastane. Tab. 4 Results of post-treatment and evaluation of wash fastness of a “Wild Mallow” dyeing (1.5 acid dyes 1% Erionyl Red A3B + 0.5% Erionyl Bordeaux A5B) on 90% Polyamide 6.6 / 10% Elastane.

[0094] Example 3: Improvement of chlorine bathing water according to ISO 105-E03 of a “blue” dye (1% acid dye Telon Blue M-GLW) on 86% polyamide 6.6 / 14% elastane

[0095] 86% polyamide 6.6 / 14% elastane (pre-fixed knit fabric) was dyed under standard conditions with the dyes 1% Telon Blue M-GLW (chlorine-sensitive dye), rinsed and then post-treated in the fresh bath as follows: pH adjustment to pH 4 (with acetic acid 60%), addition of the post-treatment agent in various quantities, treatment at 75°C for 20 min, rinsing at 40°C for 10 min, rinsing at 20°C for 10 min, drying, test for fastness to chlorine bath water (at concentrations of 20, 50 and 100 ppm active chlorine), in each case evaluation of the color change using a gray scale (1 - very poor, complete dye destruction by the chlorine, to 5 - very good, no dye destruction or color change) and calculation of the average value from evaluations by 3 volunteers.

[0096] Tab. 5 Results of post-treatment and evaluation of chlorine bath water fastness of a “blue” dye (1% acid dye Telon Blue M-GLW) on 86% polyamide 6.6 / 14% elastane.

[0097] Tab. 6 Results of post-treatment and evaluation of chlorine bath water fastness of a “blue” dye (1% acid dye Telon Blue M-GLW) on 86% polyamide 6.6 / 14% elastane.

[0098] Example example 4: Investigation of the “aging”, ie investigation of the influence of artificial aging of the aftertreatment agent on the wash fastness at 60°C of a “navy dyeing (acid dye 3.6% Sellanyl Navy Blue N-5R 180%) on 100% PA 6.6 knitwear. 100% polyamide 6.6 (knitwear) was dyed under standard conditions with the dye acid dye 3.6% Sellanyl Navy Blue N-5R 180%, rinsed and then aftertreated in a fresh bath as follows: pH adjustment to pH 4 (with acetic acid 60%), addition of the aftertreatment agent in each case 2% in various artificial aging stages, ie “fresh” aftertreatment sample vs.Post-treatment samples that were artificially "aged" in a drying cabinet depending on the time (10 and 20 days) and temperature (50°C); treatment of the textile material at 75°C for 20 min, rinsing at 40°C for 10 min, rinsing at 20°C for 10 min, drying, test of wash fastness at 60°C according to ISO 105-C03, evaluation of the bleeding of the multi-fiber accompanying fabric section polyamide using a gray scale (1 - very poor, strong bleeding, to 5 - very good, no bleeding) and calculation of the mean value from evaluations by 3 test subjects.

[0099] Tab. 7 Results of the aging test of a “Navy” dye (acid dye 3.6% Sellanyl Navy Blue N-5R 180%) on 100% PA 6.6 knitwear.

[0100] Example 5: Reservation of a 50 / 50 polyamide / wool blend (equal weight proportions) in a metal complex dye of the color “Navy” (1% Lanacron Navy SG 150% metal complex dye)

[0101] Depending on the fiber's affinity, the goal of the treatment is to partially block a fiber component to achieve various fashionable effects (tone-on-tone dyeing or bicolor effect). The chemical auxiliaries are added to the PA / WO mixture during the dyeing process. The post-treatment agent is added with a lead time of 10 minutes before the dye is added and the acidic pH is adjusted (1% Lanacron Navy SG 150% - metal complex dye). The dyeing is carried out at 98°C with a treatment time of 30 minutes, followed by a rinse with water at 40°C and 20°C. The retention of the PA content is evaluated using the following rating (5 = no retention, 1 = complete retention).

[0102] Results: without aftercare: grade 5

[0103] 2% of the compound according to the invention: Grade 3. Cited non-patent literature:

[0104] Arbenz A, Averous L, Chemical modification of tannins to elaborate aromatic biobased macromolecular architectures. Green Chemistry, 2015, 17, 2626-2646.

Claims

Patent claims 1. A process for producing a post-treatment agent for textile fibers comprising the following steps: a) providing an extract of polyphenols from at least one plant component, b) dissolving the polyphenol extract in water, c) acid-catalyzed condensation of the polyphenols with at least one C2 to C10 aldehyde, wherein an organic or inorganic acid with a pKa value below 5 is used as the acid catalyst, wherein the acid catalyst is used in a proportion in the range of 0.01 wt.% to 2 wt.%.

2. Process according to claim 1, characterized in that the polyphenols are selected from tannins, lignin, lignin derivatives and / or cardanol.

3. Process according to claim 2, characterized in that the tannins are extracted from tormentil, hops, black tea, green tea, grape fruits, the divi-divi tree, the persimmon tree, the myrobalan, sumac plants, the trillo, the valonea, bark and / or wood of oak, chestnut or acacia, or plant galls.

4. Process according to one of claims 1 to 3, characterized in that step b) is carried out at a temperature in the range of 20°C to 100°C.

5. Process according to one of claims 1 to 4, characterized in that the C2- to C10-aldehyde in step c) is glyoxal, 5-hydroxymethylfurfural or glutaraldehyde.

6. Process according to one of claims 1 to 5, characterized in that in step c) the ratio of polyphenol to O2- to O10-aldehyde is in the range from 1:0.4 to 1:

2.

7. Process according to one of claims 1 to 6, characterized in that step c) is carried out at a temperature in the range of 90°C to 120°C.

8. Process according to one of claims 1 to 7, characterized in that step c) is carried out under an inert gas atmosphere.

9. The method according to any one of claims 1 to 8, characterized in that step c) is carried out for a duration in the range of 2.5 h to 5 h.

10. The method according to any one of claims 1 to 9, further comprising adjusting the viscosity after step c).

11. A compound obtainable by a process according to any one of claims 1 to 10, having a pH in the range of 2 to 5.

12. A compound according to claim 11, having a pH in the range of 3 to 4.

13. Use of a compound according to claim 11 or 12 as a post-treatment agent and / or reserving agent for textile fibers.

14. Use according to claim 13, characterized in that the textile fiber is a polyamide, wool, silk fiber and / or a mixture thereof.

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