Dyeing method of cellulose fiber product

Abstract

Provided is a novel dyeing method with which it is possible to obtain a cellulose-based fiber product that has high dyeing fastness, does not undergo hydrolysis due to alkali treatment, and is dyed with a reactive dye, while reducing the emission of CO2 by washing with an alkali at a specific temperature and under a specific pH condition. The present invention relates to a method for dyeing a cellulose-based fiber or a fiber product comprising a cellulose-based fiber, the method being an intermittent or continuous dyeing method comprising: a dyeing reaction step in which a reactive dye is reacted with a cellulose-based fiber or a fiber product comprising a cellulose-based fiber in a dyeing solution; an alkali cleaning step for cleaning the dyed fiber or fiber product with an alkali cleaning solution having a pH value of 10-14 and a temperature of 15-70 DEG C after completely discharging or partially discharging the dyeing solution, and a cleaning step for cleaning the dyed fiber or fiber product with an alkali cleaning solution having a pH value of 10-14 and a temperature of 15-70 DEG C; and an alkali post-cleaning step in which the alkali cleaning liquid is discharged and then water is used for cleaning.

Description

TECHNICAL FIELD

[0001] The present application relates to a dyeing method of cellulose-based fibers or a fiber product containing cellulose-based fibers using a reactive dye. More specifically, the present application relates to a dyeing method including a specific washing step after a dyeing reaction step in a dyeing method of cellulose-based fibers or a dyeing method of a fiber product containing cellulose-based fibers using a reactive dye. BACKGROUND

[0002] In the industrial dyeing of cellulose-based fibers or a fiber product containing cellulose-based fibers using a reactive dye, the dyeing of the reactive dye is carried out while the reactive dye is put into a dyeing bath together with inorganic salts and an alkali agent as dyeing auxiliaries. The presence of inorganic salts is essential for promoting the absorption of the dye into the interior of the cellulose fiber, and on the other hand, the alkali agent is essential for fixing the reactive dye to the cellulose fiber. In general, it is known that the putting of inorganic salts and an alkali agent into the dyeing bath is an important element for obtaining a uniformly dyed product. In the dyeing using this reactive dye, after the end of the dyeing reaction, the unreacted dye, inorganic salts as dyeing auxiliaries, and the alkali agent must be washed. The reasons are as follows:

[0003] • If unreacted dye remains, there is a risk of color bleeding, dye staining other cloths, that is, occurrence of poor dyeing fastness;

[0004] • Inorganic salts have a dye exhaustion effect, and therefore, in a state where the salt concentration is high, the dye itself cannot be removed;

[0005] • Alkalis have skin irritation, and therefore, it is necessary to use an acid or the like to lower the pH of the cloth and perform neutralization.

[0006] Therefore, in the washing in the dyeing method using a reactive dye in the past, there is a problem that a large amount of washing must be carried out in order not to leave these chemicals in the dyed cloth.

[0007] In the washing in the past, in order to sufficiently exhaust the dye, washing at a high temperature (usually around 90°C, and at least 75°C or higher) is carried out.

[0008] In this situation, when a large amount of washing water used is heated to a high temperature, steam is usually used which is burned by a boiler or the like, and a large amount of energy is used, and furthermore, it takes time until the temperature is raised, and a large amount of electricity is used in operation, and therefore, a large amount of CO2 emission occurs.

[0009] In the following Patent Literature 1, it is proposed that, in a cleaning method using a reactive dye having a sulfate ethyl sulfonyl group and using an alkaline soaping bath of a colored fiber material, the temperature is 75 to 95°C, and in the case of cleaning in a batch system, cleaning is performed using a cleaning solution having a pH of 9 to 10, and in the case of cleaning in a continuous system, cleaning is performed using a cleaning solution having a pH of 9 to 12.

[0010] In addition, in the following Patent Literature 2, it is described that, in dyeing of cotton and cotton blended fabrics using a reactive dye, at 200°F (93.3°C), cleaning is performed using a cleaning solution to which 45 wt% of KOH: 10 to 74 wt% of sodium silicate of 50 Be: 10 to 60 wt% of lye are added at 0.25 to 1 g / L. In this case, it is presumed that the pH of the cleaning solution is about 11.

[0011] In addition, in the following Patent Literature 3, it is proposed that a soaping agent suitable for cleaning at 70 to 75°C, which can achieve the same effect as soaping at 90°C, and, as a treatment method, it is proposed that cleaning is performed using a cleaning solution containing a water-soluble salt of a polymeric fatty acid having a pH of 10 to less than 12.

[0012] Further, in the following Patent Literature 4, as a treatment method for dyed materials of disperse dyes and reactive dyes which are easily decomposed by alkali treatment, and preferably nucleophilic substitution type reactive dyes, it is proposed that treatment is performed under conditions of a pH of 8 or more, preferably a pH of 10.0 to 13.5, and a temperature of 50 to 85°C, preferably 60 to 80°C.

[0013] Prior Art Documents

[0014] Patent Literature

[0015] Patent Literature 1: Japanese Patent Application Laid-Open No. 62-78287

[0016] Patent Literature 2: U.S. Patent No. 5378242

[0017] Patent Literature 3: Japanese Patent Application Laid-Open No. 1-272888

[0018] Patent Literature 4: Japanese Patent Application Laid-Open No. 50-135383

[0019] Non-Patent Literature

[0020] Non-Patent Literature 1: Reference Material 2, Calculation Formulae and Emission Coefficients for Calculating Greenhouse Gas Emissions (https: / / www.env.go.jp / earth / ondanka / suishin_g / 3rd_edition / ref2.pdf) SUMMARY

[0021] The problem the invention aims to solve

[0022] In view of the aforementioned technical status, the problem to be solved by the present invention is to provide a novel dyeing method for cellulose fiber fabrics, particularly in the post-dyeing cleaning process of cellulose fibers and their products dyed with nucleophilic addition reactive dyes. By lowering the temperature of the cleaning solution and increasing the pH, CO2 emissions can be reduced, and cellulose fiber products with high dye fastness, which do not undergo hydrolysis due to alkali treatment and are dyed by reactive dyes can be obtained.

[0023] In order to solve this problem, the inventors of this application investigated the lowering of the temperature of the washing water used in the washing after dyeing cellulose fibers and their products using reactive dyes, as follows.

[0024] As mentioned above, in dyeing processing machinery, the washing process at high temperatures (usually around 90°C, with a minimum of 75°C) consumes energy for heating and operating time, resulting in increased CO2 emissions.

[0025] On the other hand, if the temperature is lowered for cleaning, it will not be able to clean thoroughly, resulting in poor colorfastness.

[0026] In addition, as mentioned above, there are techniques that can improve the color fastness by using alkali for cleaning. However, it is known that while alkali can improve the cleaning effect of dye, it can also react further with the already reacted dye, causing the bonds to break and resulting in poor fastness. Alternatively, it can hydrolyze the pigment itself, causing discoloration or fading.

[0027] In Patent Document 1, washing was carried out at high temperature (75-95°C) under conditions of approximately pH 9-10 (immersion) and pH 9-12 (continuous dyeing), but the results were not good. Even in this lower pH range, there was a risk of discoloration and poor fastness due to hydrolysis. Furthermore, the treatment at this higher temperature not only carried the risk of hydrolysis, but the CO2 emissions were also no different from those of the prior art.

[0028] In addition, in Patent Document 2, a cleaning process with a pH of around 11 was carried out at approximately 93°C. Under these conditions, the risk of discoloration became higher, and the CO2 emissions were no different from those of the prior art.

[0029] In addition, although the claim in Patent Document 3 specifies 75°C or below, the problem to be solved by the invention describes the desired temperature as "70~75°C". It does not consider that a temperature below this is not ideal. In cleaning at 70~75°C and pH 10~12, the effect is not high. In this lower pH range, there is also a risk of discoloration and poor fastness caused by hydrolysis.

[0030] In addition, although the claims in Patent Document 4 specify 50~80℃, the examples all involve cleaning at 80~85℃. The cleaning effect at 80~85℃ and pH above 8 is not high. In this lower pH range, there is also a risk of discoloration and poor fastness caused by hydrolysis. The CO2 emissions are not significantly improved compared with the emissions of the prior art.

[0031] On the other hand, regarding the types of reactive dyes, as reactive groups, there are "nucleophilic addition type" and "nucleophilic substitution type", and it has been clearly stated that the hydrolysis risk of "nucleophilic addition type" is particularly high.

[0032] Solution for solving the problem

[0033] In order to solve the above-mentioned problems, the inventors conducted in-depth research and repeated experiments, and unexpectedly discovered that, especially in the washing process after dyeing in the dyeing method of cellulose fibers and their products using nucleophilic addition reaction dyes, by lowering the temperature of the washing solution and increasing the pH, it is possible to reduce CO2 emissions and avoid dye hydrolysis caused by alkali treatment. Furthermore, it is possible to obtain a uniformly dyed product with high color fastness and no color unevenness, thereby completing the present invention.

[0034] That is, the present invention is as follows.

[0035] [1] A dyeing method for cellulose fibers or fiber products containing cellulose fibers, which is an intermittent or continuous dyeing method, comprising the following steps:

[0036] The dyeing reaction process involves reacting cellulose fibers or fiber products containing cellulose fibers with reactive dyes in a dyeing solution.

[0037] The alkaline cleaning process involves draining all or part of the aforementioned dyeing solution, followed by cleaning the dyed fibers or fiber products with an alkaline cleaning solution at a pH of 10-14 and a temperature of 15-70°C; and

[0038] The post-alkali cleaning process involves draining the aforementioned alkaline cleaning solution and then cleaning with water.

[0039] [2] According to the dyeing method described in [1] above, in the aforementioned alkaline washing process, acid is added to the aforementioned water and neutralized using an acid washing solution containing acid.

[0040] [3] According to the dyeing method described in [1] or [2] above, there is an alkali pre-cleaning step between the dyeing reaction step and the alkali cleaning step, which uses an aqueous solution for cleaning.

[0041] [4] The staining method according to any one of [1] to [3] above, wherein the aforementioned staining method is an intermittent staining method, and the pH of the aforementioned alkaline washing solution is 10 to 13 and the temperature is 15°C to 70°C or below.

[0042] [5] The dyeing method according to any one of [1] to [3] above, wherein the dyeing method is a continuous dyeing method, and the pH of the alkaline washing solution is 12 to 14 and the temperature is 15°C to 60°C.

[0043] [6] The staining method according to any one of [1] to [5] above satisfies the following relationship (1).

[0044] -0.07x+13≤y<-0.07x+17

[0045] {In the formula, x is the temperature value between 15 and 70°C, and y is the pH value between 10 and 14.}

[0046] [7] The dyeing method according to any one of [1] to [6] above, wherein the dyeing solution is maintained at a temperature of 5°C or higher and 70°C or lower throughout the entire alkaline washing process.

[0047] [8] The staining method according to any one of [1] to [7] above, wherein the aforementioned reactive dye comprises a nucleophilic addition reactive dye.

[0048] [9] The dyeing method according to any one of [3] to [8] above, wherein in the aforementioned pre-alkali cleaning step, the cleaning is performed with water at a temperature of 5 to 70°C at a bath ratio of 1:100 or less.

[0049]

[10] The dyeing method according to any one of [1] to [9] above, wherein in the aforementioned alkaline cleaning step, the cleaning is performed using an alkaline cleaning solution at a temperature of 15 to 70°C with a bath ratio of 1:100 or less.

[0050]

[11] The dyeing method according to any one of [1] to

[10] above, wherein in the above-mentioned alkaline washing step, the washing is performed with water at a temperature of 5 to 70°C at a bath ratio of 1:100 or less.

[0051] The effects of the invention

[0052] According to the dyeing method of the present invention, especially in the post-dyeing cleaning process of dyeing cellulose fibers and their products using nucleophilic addition reactive dyes, CO2 emissions can be reduced by lowering the temperature of the cleaning solution and increasing the pH, and cellulose fiber products with high dye fastness, which do not hydrolyze due to alkali treatment and are dyed by reactive dyes can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 FIG. is a schematic view of a jet dyeing machine (an example of an intermittent cleaning device) that can be used in each cleaning process of the dyeing method of the present invention.

[0054] Figure 2 FIG. is a schematic view of an open soaper type continuous washing machine (an example of a continuous intermittent cleaning device) that can be used in each cleaning process of the dyeing method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0055] Hereinafter, embodiments of the present invention will be described in detail.

[0056] One embodiment of the present invention is a method for dyeing cellulose-based fibers or fiber products containing cellulose-based fibers, which is an intermittent or continuous dyeing method, and includes the following steps:

[0057] A dyeing reaction step in which cellulose-based fibers or fiber products containing cellulose-based fibers are reacted with reactive dyes in a dyeing solution;

[0058] An alkali cleaning step in which after all or part of the aforementioned dyeing solution is discharged, the dyed fibers or fiber products are cleaned with an alkali cleaning solution having a pH of 10 to 14 and a temperature of 15 to 70 °C; and

[0059] An after-alkali cleaning step in which after the aforementioned alkali cleaning solution is discharged, it is cleaned with water.

[0060] The form of the cellulose-based fibers or fiber products containing cellulose-based fibers dyed by the dyeing method of the present embodiment is not particularly limited, and various forms of products such as yarns, woven fabrics, weft knitted fabrics, non-woven fabrics, and sewn products can be cited. The cellulose-based fibers are not particularly limited, and examples include cotton, hemp, rayon, cuprammonium rayon, lyocell, cellulose fibers by the organic solvent method, cellulose fibers by the ionic liquid method, etc., preferably cotton, rayon, cuprammonium rayon, lyocell, cellulose fibers by the organic solvent method, and more preferably cotton, rayon, cuprammonium rayon. Regarding the fibers other than cellulose-based fibers in the fiber products containing cellulose-based fibers dyed by the dyeing method of the present embodiment, they can be dyed in combination with known dyeing methods.

[0061] The dyeing method of the present embodiment is not particularly limited, and printing dyeing, solid color dyeing (Japanese: 無地染) are both acceptable, and solid color dyeing is preferred. As the dye reaction step in the dyeing method of the present embodiment, pad-steam method, pad-batch method, dipping method, etc. can be cited, but they are not particularly limited to them.

[0062] The equipment used in each cleaning step of the dyeing method of this embodiment can be either intermittent or continuous, without particular limitation. As for intermittent equipment, preferred examples include package dyeing machines, skein dyeing machines, liquid flow dyeing machines, airflow dyeing machines, beam dyeing machines, roll dyeing machines, rope dyeing machines, rotary dyeing machines, paddle dyeing machines, and MINI-COLOR dyeing machines. Liquid flow dyeing machines (see [reference]) are further preferred examples. Figure 1 As a continuous process, a flat-width soaping continuous washing machine or a continuous rope dyeing machine is preferred, and a flat-width soaping continuous washing machine can be further preferred (see [reference]). Figure 2 ).

[0063] The reactive dyes used in the dyeing method of this embodiment are preferably reactive dyes having nucleophilic addition reactive groups, or difunctional or polyfunctional reactive dyes having both nucleophilic addition reactive groups and nucleophilic substitution reactive groups. Examples of nucleophilic addition reactive groups include saturated alkane monocarboxylic acid amides, saturated alkane dicarboxylic acid amides, saturated alkane monocarboxylic acid amides, cycloalkanes formamides, olefin monocarboxylic acid amides, olefin dicarboxylamides, saturated aliphatic ketones, saturated aliphatic sulfonamides, vinyl sulfonamides, β-saturated ethyl sulfones, vinyl sulfones, and sulfate ethyl sulfonic acid groups, with vinyl sulfones and sulfate ethyl sulfonic acid groups being preferred. Nucleophilic substitution reactive groups can be listed as pyridine, pyridazine, pyridazone, pyrimidine, S-triazine, 1,2,4-triazine, thiazole, benzoxazole, benzothiazole, quinoline, isoquinoline, quinoxaline, quinazoline, and phthalazine, with 1,2,4-triazine being the preferred type.

[0064] Inorganic salts used in staining reaction methods include, but are not particularly limited to, sodium sulfate, potassium sulfate, sodium chloride, potassium chloride, or mixtures thereof. Alkali agents include, but are not particularly limited to, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium metasilicate, trisodium phosphate, tripotassium phosphate, or mixtures thereof.

[0065] The dyeing method of this embodiment includes: the aforementioned reaction dyeing step, an alkaline cleaning step for removing residual dyes after the dyeing solution is discharged from the dyeing bath, and an alkaline post-cleaning step for cleaning after the alkaline cleaning solution is discharged.

[0066] (Alkali cleaning process)

[0067] The alkaline cleaning process is described in detail below.

[0068] The dyeing method of this embodiment is a dyeing method for cellulose fibers or fiber products containing cellulose fibers. It is an intermittent or continuous dyeing method and includes the following steps:

[0069] The dyeing reaction process involves reacting cellulose fibers or fiber products containing cellulose fibers with reactive dyes in a dyeing solution.

[0070] The alkaline cleaning process involves draining all or part of the aforementioned dyeing solution, followed by cleaning the dyed fibers or fiber products with an alkaline cleaning solution at a pH of 10-14 and a temperature of 15-70°C; and

[0071] The post-alkali cleaning process involves draining the aforementioned alkaline cleaning solution and then cleaning with water.

[0072] The aforementioned alkaline cleaning process reduces CO2 emissions by lowering the temperature of the cleaning solution and increasing the pH, and produces cellulose fiber products with high color fastness that do not hydrolyze due to alkaline treatment and are dyed by reactive dyes. From the viewpoint of reducing the amount of alkali used and eliminating the burden of drainage, a single treatment is preferred, but multiple cleaning treatments may also be included.

[0073] The aforementioned alkaline cleaning solution is an aqueous solution containing one or more alkalis with a pH of 10-14 and a temperature of 15-70°C. It can be selected from the viewpoints of the hydrolysis ease of the dye used, the cleaning treatment time, and the required wet fastness. From the viewpoint of CO2 emissions, and considering that higher temperatures increase the risk of hydrolysis, the preferred temperature is 15-60°C, more preferably 15-50°C. Furthermore, at higher pH values, the addition of alkali is easier to control, and the cleaning performance is improved; therefore, the preferred pH is 10.5-14, more preferably 11-14.

[0074] Regarding the aforementioned alkaline cleaning solution, when the treatment is carried out intermittently, the treatment time becomes longer and the risk of hydrolysis increases. Therefore, an aqueous solution with a pH of 10 to 13 and a temperature of 15 to 70°C is preferred. In addition, when the treatment is carried out continuously, the treatment time is short and the risk of insufficient cleaning increases. On the other hand, if the temperature is high, alkali-containing vapors are generated, which poses a danger to the work. Therefore, a pH of 12 to 14 and a temperature of 15 to 60°C are preferred.

[0075] Furthermore, in order to eliminate the effects of hydrolysis caused by high-temperature alkaline cleaning solution and to eliminate insufficient cleaning caused by low-temperature alkaline cleaning solution, the aforementioned alkaline cleaning solution is preferably an aqueous solution that satisfies the following relationship (1).

[0076] -0.07x+13≤y<-0.07x+17

[0077] {In the formula, x is the temperature value between 15 and 70°C, and y is the pH value between 10 and 14.}

[0078] The aforementioned alkaline cleaning solution may contain dispersants, wetting agents, bath softeners, bath smoothers, emulsifiers, soaping agents, etc. The alkaline solution is not particularly limited, and may include sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium metasilicate, trisodium phosphate, tripotassium phosphate, or mixtures thereof. Sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide are preferred, and sodium carbonate and sodium hydroxide are even more preferred.

[0079] (Post-alkali cleaning process)

[0080] The following is a detailed description of the post-alkali cleaning method.

[0081] The dyeing method of this embodiment includes an alkaline cleaning step in which an alkaline cleaning solution is added after all or part of the alkaline cleaning solution has been drained.

[0082] The post-alkali cleaning process is a process of using water, which is the post-alkali cleaning solution, to wash away the alkali used in the alkali cleaning solution. It can be a single process, but considering that alkali residue may cause serious defects such as skin damage or hinder subsequent finishing processes, it is preferable to include multiple cleaning processes.

[0083] From the viewpoint of suppressing CO2 emissions by setting the water of the aforementioned alkaline cleaning solution to a low temperature, the temperature is preferably 5°C to 70°C, more preferably 5°C to 50°C, and even more preferably 15°C to 50°C from the viewpoint that low temperature is easily affected by the temperature.

[0084] To eliminate alkali residue, acid can be added to the water used as the aforementioned alkaline cleaning solution. There are no restrictions on the type of acid used; it can be any of citric acid, malic acid, acetic acid, formic acid, sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, etc. Preferably, it is an acid with low corrosiveness to metals, and more preferably formic acid, acetic acid, citric acid, or malic acid. Furthermore, the water used as the aforementioned alkaline cleaning solution may, as desired, contain dispersants, wetting agents, bath softeners, bath smoothers, emulsifiers, soaping agents, etc.

[0085] (Pre-alkali cleaning process)

[0086] Between the aforementioned dyeing reaction step and the aforementioned alkaline cleaning step, there may be an alkaline pre-cleaning step that uses an aqueous solution for cleaning.

[0087] From the perspective of being able to remove high concentrations of salt that have a dye exhaustion effect and to improve the cleaning effect of the alkaline cleaning process, it is desirable to add a pre-alkaline cleaning process.

[0088] The water used as the aforementioned pre-alkali cleaning solution is not particularly limited, and may contain dispersants, wetting agents, bath softeners, bath smoothers, emulsifiers, soaping agents, etc., depending on the desired effect. From the viewpoint of removing salt, water is preferred.

[0089] From the viewpoint of suppressing CO2 emissions by setting the water temperature to the aforementioned pre-alkali cleaning solution, the preferred temperature is 5°C to 70°C, more preferably 5°C to 50°C. From the viewpoint that low temperatures are easily affected by air temperature and are not conducive to stable dyeing, a temperature of 15°C to 50°C is even more preferred.

[0090] The liquor ratio in the aforementioned alkaline cleaning, post-alkaline cleaning, and pre-alkaline cleaning processes depends on the cleaning machinery. When using continuous cleaning machinery and processing large volumes, a liquor ratio higher than 1:1 is preferable. If the liquor ratio increases, the CO2 emissions related to the heating of the cleaning solution increase. Therefore, a ratio of 1:100 or less is preferred, and more preferably 1:30 or less.

[0091] Example

[0092] The present invention will be specifically described below with examples and comparative examples, but the present invention is not limited to the examples. Furthermore, the calculation of CO2 emission reductions in the examples and the various evaluations of each yarn or fiber product were performed using the methods described below.

[0093] (1) Calculation of CO2 emissions

[0094] The CO2 emissions (kg-CO2e) are calculated using the following formula, which measures the electrical and steam consumption involved in the operation of the dyeing machine.

[0095] W = E × α + S × β

[0096] {Where, W: CO2 emissions (kgCO2e), E: electricity consumption (MJ), S: steam consumption (MJ), α: CO2 emission coefficient of electricity (kg-CO2e / MJ), β: CO2 emission coefficient of steam (kg-CO2e / MJ).}

[0097] Here, α and β are the CO2 emission coefficients (kg-CO2e / MJ) of electricity and steam at a certain point in time, which are values ​​published by the Japanese Environment Agency. The CO2 emission coefficient at a certain point in time is not specifically limited; an example can be found in Non-Patent Literature 1 (Reference 2). The CO2 emission coefficients are listed in the formulas and emission coefficients for calculating greenhouse gas emissions (https: / / www.env.go.jp / earth / ondanka / suishin_g / 3rd_edition / ref2.pdf). For example, the emission coefficient for electricity, α, is 0.1542 (kg-CO2e / MJ), and the emission coefficient for steam, β, is 0.0600 (kg-CO2e / MJ). In the following examples, the CO2 emissions (kg-CO2e) are calculated using emission coefficients of α=0.1542 (kg-CO2e / MJ) and β=0.0600 (kg-CO2e / MJ). In comparative examples using various dyeing methods, raw material types, and dyes, samples using conventional water washing methods are used as "blanks." If the CO2 emissions (kg-CO2e) decrease compared to the blank, it is judged as "optimized"; if it remains unchanged, it is evaluated as "equivalent".

[0098] (2) Color fading

[0099] For dyed fiber products, a spectrophotometer (Gretagmacbeth, model: Color-Eye7000A) was used to measure the color under D56 light source and a field of view of 10 degrees. The L* value in the CIE1976 L*a*b* color space was calculated. In addition, in comparative examples using various dyeing methods, raw material types, and dyes, samples using conventional water washing methods were set as "blanks", and the ΔL* value was calculated using the following formula.

[0100] ΔL* value = L* value of blank - L* value of analyte

[0101] When the ΔL* value is below 0.5, there is no color fading, which can be judged as good. In addition, the case where the ΔL* value is above 0.5 but below 1.0 is judged as "slightly worsened", and the case where it is above 1.0 is judged as "worsened".

[0102] (3) Perspiration fastness

[0103] The perspiration fastness test was conducted according to the test method for color fastness relative to perspiration specified in JIS L 0848. Furthermore, the white cloth used for the staining test was a multi-fiber interwoven fabric based on JIS L 0803, consisting of eight fibers (cotton, nylon, acetate fiber, wool, rayon, acrylonitrile fiber, silk, and polyester) interwoven into a straight stripe pattern. In comparative examples using various dyeing methods, raw material types, and dyes, samples using conventional washing methods were designated as "blanks." If the combined acid perspiration fastness and alkaline perspiration fastness was higher than the blank, it was judged as "improved"; if they were the same, it was judged as "equivalent"; and if they were lower, it was judged as "deteriorated."

[0104] (4) Dyed material

[0105] In addition, cupro knitted fabric and cotton knitted fabric were used as the dyed materials in the examples and comparative examples. They were obtained as follows.

[0106] Prepare cupro knitted fabrics as follows.

[0107] Five samples obtained by single-knitting cuprammonium fiber 167dtex using a 24-needle single-knitting test tube knitting machine (manufactured by Eikoh Industrial Co., Ltd., model: NCR-ES) at a liquid temperature of 90°C were treated for 30 minutes in a bath containing 0.1 parts sodium carbonate, 0.1 parts surfactant SCOUROL (manufactured by Beiguang Chemical Co., Ltd.), and 100 parts water. After treatment, the samples were dehydrated and dried to obtain the dyed cuprammonium knitted fabric.

[0108] Prepare cotton knitted fabrics as follows.

[0109] Obtain unmercerized cotton knitted fabrics, which are produced by scouring and bleaching commonly used smooth knitted fabrics made of cotton, for use as dyeing materials.

[0110] The cupro woven fabric is prepared as follows.

[0111] A cupro dyeing pre-fabricated fabric, obtained by scouring a woven fabric greige, is used as the dyeing material. The woven fabric greige is made by using a loom to beat 84dtex cupro fibers as warp yarns and 110dtex cupro fibers as weft yarns.

[0112] [Comparative Example 1a]

[0113] Dyeing process: As an intermittent dyeing method, a MINI-COLOR dyeing machine (manufactured by TEXAM Corporation, UR MINI-COLOR type) is used for dyeing. First, the dyeing reaction process is carried out. 140 parts of water at 20°C are added to a stainless steel kettle with a diameter of 72 mm and a height of 110 mm. Then, 5 parts of cupro knitted fabric, which is the material to be dyed, are added. Finally, a total of 5 parts of reactive dyes with nucleophilic addition reactive groups are added (0.125 parts of Remazol BrRed BB 150% (manufactured by DyStar Japan Corporation), 0.0625 parts of Remazol BrYellow GL 150% (manufactured by DyStar Japan Corporation), and 0.0625 parts of KPZOL BLACK B 150POWDER (manufactured by Kiwa Chemical Industry Co., Ltd.). Subsequently, after raising the liquid temperature to 60°C, 7.5 parts of sodium sulfate were added. After the dye was completely absorbed, 2.25 parts of sodium carbonate were added, and the liquid temperature was maintained at 60°C for 30 minutes to allow the dye to react. Then, 120 portions of the dyeing solution were taken out, yielding the dyed material before the washing process.

[0114] Next, as a cleaning process, a total of four cleaning processes were performed. Furthermore, the heating operation in each process was carried out at an initial temperature of 15°C and a heating rate of 3°C / minute. The initial temperature and heating rate were the same in all the following examples and comparative examples.

[0115] First cleaning process: Add 70 parts water, heat to 20℃ and maintain for 10 minutes to clean, then remove 70 parts of the cleaning solution.

[0116] Second cleaning process: Add 70 parts of liquid prepared by dissolving 0.25 parts of acetic acid in water, heat to 20°C and maintain for 10 minutes for cleaning, then remove 70 parts of the cleaning solution.

[0117] The third cleaning process: Add 70 parts of water, heat to 90℃, and maintain the temperature for 10 minutes to clean. After that, remove 70 parts of the cleaning solution.

[0118] Fourth cleaning process: Add 70 parts water, heat to 20℃ and maintain for 10 minutes to clean, take out the dyed cloth, and dehydrate and dry it using known methods to obtain the dyed material after the cleaning process.

[0119] For dyed products after the washing process, evaluate color fading and perspiration fastness. Additionally, calculate CO2 emissions from both the dyeing and washing processes.

[0120] [Comparative Examples 1b-1c, Examples 1a-1d]

[0121] Dyeing process: Using the dye and method of Comparative Example 1a, 5 parts of cuprammonium knitted fabric, which is the subject of dyeing, are reacted with the dye, the liquid is taken out, and the dyed material before the washing process is obtained.

[0122] Next, as a cleaning process, the cleaning solution and temperature were changed as shown in Table 1 below, and the cleaning, dehydration and drying were performed in the same manner as in Comparative Example 1a to obtain the dyed material after the cleaning process.

[0123] The evaluation of color fading, perspiration fastness, and CO2 emissions was compared with that of Comparative Example 1a. The comparison results are summarized in Table 2 below.

[0124] [Comparative Examples 2a, 2b; Examples 2a, 2b]

[0125] Dyeing process: Five parts of cotton knitted fabric were used as the dyed material. In addition, the dye and method of Comparative Example 1a were used to make the dye react, the liquid was taken out, and the dyed material before the washing process was obtained.

[0126] Next, as a cleaning process, the cleaning solution and temperature were changed as shown in Table 1 below, and the cleaning, dehydration and drying were performed in the same manner as in Comparative Example 1a to obtain the dyed material after the cleaning process.

[0127] The evaluation results and comparison results of color fading, perspiration fastness, and CO2 emissions are summarized in Table 2 below.

[0128] [Comparative Example 3a]

[0129] Dyeing process: Five portions of cotton knitted fabric were changed to be dyed. Otherwise, the dye and method of Comparative Example 1a were used to react the dye, the liquid was taken out, and the dyed product before the washing process was obtained.

[0130] Next, as part of the cleaning process, a total of 6 cleaning treatments are performed.

[0131] First cleaning step: Add 70 parts water, heat to 20℃, and maintain for 10 minutes to clean. After that, remove 70 parts of the cleaning solution.

[0132] Second cleaning process: Add 70 parts of liquid prepared by dissolving 0.4 parts of acetic acid in water, heat to 30°C and maintain for 10 minutes to clean, then remove 70 parts of the cleaning solution.

[0133] The third cleaning process involves adding 70 parts of liquid containing 0.2 parts of soap detergent MEISANOL KHM (Mingcheng Chemical Industry Co., Ltd.), heating the solution to 90°C, and maintaining the temperature for 10 minutes to perform the cleaning. Afterward, 70 parts of the cleaning solution are removed.

[0134] Fourth cleaning step: Add 70 parts water, heat to 20℃, maintain for 10 minutes to clean, then remove 70 parts of the cleaning solution.

[0135] Fifth cleaning step: Add 70 parts water, heat to 20℃, and maintain for 10 minutes to clean. After that, remove 70 parts of the cleaning solution.

[0136] The sixth cleaning process: Add 70 parts of water, heat to 20°C, and maintain for 10 minutes to clean. Take out the dyed fabric and dehydrate and dry it using known methods to obtain the dyed product after the cleaning process.

[0137] For dyed products after the washing process, evaluate color fading and perspiration fastness. Additionally, calculate CO2 emissions from both the dyeing and washing processes.

[0138] [Comparative Examples 3b-3d, Examples 3a-3g]

[0139] Dyeing process: Using the dye and method of Comparative Example 1a, 5 parts of cotton knitted fabric, which is the subject of dyeing, are reacted with the dye, the liquid is taken out, and the dyed fabric before the washing process is obtained.

[0140] Next, as a cleaning process, the cleaning solution and temperature were changed as shown in Table 1 below, and the cleaning, dehydration and drying were performed in the same manner as in Comparative Example 3a to obtain the dyed material after the cleaning process.

[0141] The evaluations of color fading, fastness to perspiration, and CO2 emissions were compared with those of Comparative Example 3a. The comparison results are summarized in Table 2 below.

[0142] [Comparative Example 4a, Examples 4a, 4b]

[0143] Dyeing process: Five parts of cupro knitted fabric were used as the dyed material, and a total of 0.25 parts of reactive dyes having nucleophilic addition reactive groups and nucleophilic substitution reactive groups were used (0.125 parts of Remazol Red RGB (manufactured by DyStar Japan), 0.0675 parts of Remazol GoldYellow RGB (manufactured by DyStar Japan), and 0.0675 parts of Remazol Navy RGB (manufactured by DyStar Japan). Otherwise, the dyes were reacted using the method of Comparative Example 1a, the liquid was removed, and the dyed material before the washing process was obtained.

[0144] Next, as a cleaning process, the cleaning solution and temperature were changed as shown in Table 1 below, and the cleaning, dehydration and drying were performed in the same manner as in Comparative Example 1a to obtain the dyed material after the cleaning process.

[0145] The evaluation and comparison results of color fading, perspiration fastness, and CO2 emissions are summarized in Table 2 below.

[0146] [Comparative Examples 5a-5c, Examples 5a, 5b]

[0147] Dyeing process: Using the dye and method of Comparative Example 4a, 5 parts of cotton knitted fabric, which is the subject of dyeing, react with the dye, and the liquid is taken out to obtain the dyed fabric before the washing process.

[0148] Next, as a cleaning process, the cleaning solution and temperature were changed as shown in Table 1 below, and the cleaning, dehydration and drying were performed in the same manner as in Comparative Example 3a to obtain the dyed material after the cleaning process.

[0149] The evaluation and comparison results of color fading, perspiration fastness, and CO2 emissions are summarized in Table 2 below.

[0150] [Comparative Example 6a]

[0151] Dyeing Process: As a continuous dyeing method, pad-steam dyeing is performed. First, a reaction process is carried out. 10 parts of the cupro woven fabric to be dyed are immersed in 100 parts of an aqueous solution containing 5 parts of RemazolBrRedBB 150% (manufactured by DyStar Japan) with nucleophilic addition reactive groups, 5 parts of sodium sulfate, and 1 part of sodium hydroxide. The mixture is repeatedly spun twice in this liquid using a padding machine until the padding ratio reaches 80%. Afterwards, using a press applicable to the JIS L1096H method for pressure dimensional change rate, a test piece and filter paper are placed on the upper platen, and the lower platen is lowered to 20 mm above the test piece. A steam treatment is performed with steam set to 100°C and 490 kPa for 90 seconds, completing the reaction process and obtaining the dyed fabric before the washing process.

[0152] Next, as part of the cleaning process, a total of 5 cleaning treatments are performed.

[0153] First cleaning process: Immerse it in 100 parts of water heated to 30°C for 10 seconds, then repeatedly wring it twice in the liquid until the liquid ratio is 80%, and then clean it.

[0154] The second cleaning process involves immersing the sample in an aqueous solution containing 0.02 parts citric acid and 0.02 parts MEISANOL KHM (Mingcheng Chemical Industry Co., Ltd.) heated to 80°C for 10 seconds. The sample is then repeatedly squeezed twice in the liquid using a rolling mill until the liquid content reaches 80%, and then cleaned.

[0155] The third cleaning process is carried out in the same way as the second cleaning process.

[0156] The fourth cleaning process involves immersing the liquid in 100 parts of water heated to 30°C for 10 seconds, then repeatedly wringing the liquid in the liquid twice until the liquid yield is 80%, and then cleaning.

[0157] The fifth cleaning step is performed in the same way as the fourth cleaning step. Finally, the product is dried using a known method to obtain the dyed material after the cleaning process.

[0158] [Example 6b]

[0159] Dyeing process: Using the same dye and method as in Example 6a, 10 portions of cupro woven fabric as the subject of dyeing were dyed to obtain the dyed product before the washing process.

[0160] Next, as a cleaning process, the cleaning solution and temperature were changed as shown in Table 1 below, and the same steps as in Comparative Example 6a were followed to perform cleaning, dehydration, and drying to obtain the dyed material after the cleaning process.

[0161] The evaluations of color fading, fastness to perspiration, and CO2 emissions were compared with those of Comparative Example 6a. The comparison results are summarized in Table 2 below.

[0162] [Table 1]

[0163]

[0164] [Table 2]

[0165]

[0166] In the sample groups (Comparative Examples 1a-c and Examples 1a-d) where the dyeing method was intermittent, the dyed material was cuprammonium knitted fabric, the dye was a nucleophilic addition reaction dye, and the number of washes was 4, it was confirmed that: compared with Comparative Example 1a which did not have alkaline washing, Examples 1a-d did not have hydrolysis, the sweat fastness was optimized, and the CO2 emissions were reduced.

[0167] It can be confirmed that in Comparative Example 1b, which did not undergo alkaline washing, although low-temperature dyeing was performed, it deteriorated compared to Comparative Example 1a. In Comparative Example 1c, although an alkaline washing process was performed, the temperature range was 90°C, which resulted in hydrolysis, color fading, and deterioration of fastness.

[0168] In the sample groups (Comparative Examples 2a-b and Examples 2a-b) where the dyeing method was intermittent, the dyed material was cotton knitted fabric, the dye was a nucleophilic addition dye, and the number of washes was 4, it was confirmed that: compared with Comparative Example 2a, which did not undergo alkaline washing, Example 2a showed no hydrolysis, optimized perspiration fastness, and reduced CO2 emissions. In Example 2b, at 70°C and pH 11, CO2 emissions were reduced, and the fastness was the same, but color fading due to hydrolysis was confirmed.

[0169] In Comparative Example 2b, although an alkaline cleaning process was performed, the temperature range was 90°C, and even though the pH range was as low as 9.4, the fastness deteriorated due to hydrolysis.

[0170] In the sample groups (Comparative Examples 3a-d and Examples 3a-g) where the dyeing method was intermittent, the dyed material was cotton knitted fabric, the dye type was nucleophilic addition dye, and the number of washes was 6, it was confirmed that compared with Comparative Examples 3a and 3b, which did not involve alkaline washing, Examples 3a, 3c, 3d, 3f, and 3g showed no hydrolysis, optimized perspiration fastness, and reduced CO2 emissions. In Example 3b, at 70°C and pH 12.5, and in Example 3e, at 50°C and pH 13.6, color fading due to hydrolysis was confirmed, but CO2 emissions were reduced.

[0171] In Comparative Example 3b, there was no alkaline cleaning process and the temperature range was 70°C. Compared with Comparative Example 3a, CO2 emissions were reduced, but the fastness deteriorated due to insufficient cleaning.

[0172] In Comparative Example 3c, although an alkaline cleaning process was involved, the temperature was 30°C and the pH was 14.2, which exceeded 14. Compared with Comparative Example 3a, CO2 emissions were reduced, but the fastness deteriorated significantly due to hydrolysis.

[0173] In Comparative Example 3d, although an alkaline cleaning process was present, the temperature was 60°C and the pH was 9.8, which is lower than 10. Compared with Comparative Example 3a, CO2 emissions were reduced, but the fastness deteriorated significantly due to insufficient cleaning.

[0174] In Comparative Examples 4a and Examples 4a-b, where the dyeing method was intermittent, the dyed fabric was cuprammonium knitted fabric, the dye was a reactive dye with both nucleophilic addition and nucleophilic substitution reactive groups, and the number of washes was 4, it was confirmed that: compared to Comparative Example 4a, which did not undergo alkaline washing, Example 4a showed no hydrolysis, optimized sweat fastness, and reduced CO2 emissions. In Example 4b, at 60°C and pH 13.1, color fading due to hydrolysis was observed, but CO2 emissions were reduced.

[0175] In the sample groups (Comparative Examples 5a-c and Examples 5a-b) where the dyeing method was intermittent, the dyed material was cotton knitted fabric, the dye was a reactive dye with both nucleophilic addition and nucleophilic substitution reactive groups, and the number of washes was 6, it was confirmed that: compared with Comparative Example 5a which did not have alkaline washing, Examples 5a and b did not have hydrolysis, the sweat fastness was optimized, and the CO2 emissions were reduced.

[0176] In Comparative Example 5b, although an alkaline cleaning process was involved, the temperature was 30°C and the pH was 14.4, which exceeded 14. Compared with Comparative Example 3a, CO2 emissions were reduced, but the fastness deteriorated significantly due to hydrolysis.

[0177] In Comparative Example 5c, although an alkaline cleaning process was included, the temperature was 60°C and the pH was 9.8, which is lower than 10. Compared with Comparative Example 3a, CO2 emissions were reduced, but the fastness deteriorated significantly due to insufficient cleaning.

[0178] In the sample group, namely Comparative Example 6a and Example 6a, where the dyeing method is continuous, the dyed material is cuprammonium woven fabric, the dye is a nucleophilic addition reactive dye, and the number of washes is 5, it can be confirmed that: compared with Comparative Example 6a which does not have alkaline washing, Example 6a has no hydrolysis, the same sweat fastness, and reduced CO2 emissions.

[0179] Industrial availability

[0180] According to the present invention, a novel dyeing method can be provided, particularly in the post-dyeing washing of cellulose fibers and their products using nucleophilic addition reactive dyes, by lowering the temperature of the washing solution and increasing the pH, thereby reducing CO2 emissions and obtaining cellulose fiber products with high color fastness, which do not hydrolyze due to alkali treatment and are dyed by reactive dyes. Therefore, the present invention can be suitably used in the dyeing of cellulose fibers and their products using reactive dyes.

[0181] Explanation of reference numerals in the attached figures

[0182] 1. Liquid dyeing machine

[0183] 2 Storage tank

[0184] 3. Heat exchanger

[0185] 4 nozzles

[0186] 5. Greige fabric

[0187] 6 dye bath

[0188] 7. Reaction process machinery: Pad-steam dyeing machine

[0189] 8. Greige fabric before dyeing (reaction process, cleaning process)

[0190] 9 dye bath

[0191] 10. Rolling Mill

[0192] 11 Steam Box

[0193] 12. Cleaning process machinery: flat-width soap washing machine, continuous water washing machine

[0194] 13. Drum Dryer

[0195] 14. Greige fabric after dyeing (reaction process, washing process)

Claims

1. A method for dyeing cellulose fibers or fiber products containing cellulose fibers, comprising the following steps: It is an intermittent or continuous staining method, which includes the following steps: The dyeing reaction process involves reacting cellulose fibers or fiber products containing cellulose fibers with reactive dyes in a dyeing solution. The alkaline cleaning process involves draining all or part of the dyeing solution, followed by cleaning the dyed fibers or fiber products with an alkaline cleaning solution at a pH of 10-14 and a temperature of 15-70°C; and The alkaline cleaning process involves draining the alkaline cleaning solution and then cleaning with water.

2. The staining method according to claim 1, wherein, In the alkaline cleaning process, acid is added to the water to neutralize it using an acidic cleaning solution containing acid.

3. The dyeing method according to claim 1 or 2, wherein a pre-alkali cleaning step using an aqueous solution is provided between the dyeing reaction step and the alkali cleaning step.

4. The staining method according to claim 1 or 2, wherein, The dyeing method is an intermittent dyeing method, and the pH of the alkaline washing solution is 10-13 and the temperature is below 15℃-70℃.

5. The staining method according to claim 1 or 2, wherein, The dyeing method is a continuous dyeing method, and the pH of the alkaline washing solution is 12~14 and the temperature is 15℃~60℃.

6. The staining method according to claim 1 or 2, which satisfies the following relationship as expressed in equation (1), -0.07x+13≤y<-0.07x+17 In the formula, x is the temperature value of 15~70℃, and y is the pH value of 10~14.

7. The staining method according to claim 1 or 2, wherein, Throughout the alkaline cleaning process, the dyeing solution is maintained at a temperature above 5°C and below 70°C.

8. The staining method according to claim 1 or 2, wherein, The reactive dyes include nucleophilic addition reactive dyes.

9. The staining method according to claim 3, wherein, In the pre-alkali cleaning process, a bath ratio of less than 1:100 is used to clean the water at a temperature of 5~70℃.

10. The staining method according to claim 1 or 2, wherein, In the alkaline cleaning process, an alkaline cleaning solution with a temperature of 15~70℃ is used for cleaning at a liquor ratio of less than 1:

100.

11. The staining method according to claim 1 or 2, wherein, In the alkaline cleaning process, a bath ratio of less than 1:100 is used to clean the water at a temperature of 5~70℃.

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