Method for producing polyester-dyed article

Abstract

To establish an anhydrous dyeing and finishing technology with low environmental load that is effective and useful for practical and industrial applications in polyester dyeing employing disperse dyes.SOLUTION: As a solvent used in a dyeing solution for polyester dyeing with disperse dyes, specific next-generation dry-cleaning solvents such as decamethylcyclopentasiloxane (D5) and dibutoxymethane (K4) are employed.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing dyed polyester products, characterized by using a specific next-generation dry cleaning solvent in dyeing. [Background technology]

[0002] In the textile and apparel industry, from yarn manufacturing to clothing production, the intermediate dyeing process uses the most energy and water and has a significant environmental impact. From the perspective of the SDGs, there is an urgent need to establish waterless dyeing technology.

[0003] The "Textile Technology Roadmap" formulated by the Ministry of Economy, Trade and Industry in 2022 also lists "waterless dyeing and processing technology" from a sustainability perspective. Supercritical carbon dioxide dyeing has been considered as an anhydrous dyeing method, but it requires dedicated high-pressure equipment, and there are significant technical difficulties involved in practical application and industrialization, such as controlling the high pressure and maintaining the equipment.

[0004] On the other hand, many attempts have been reported to dye synthetic fibers using organic solvents instead of water, and in particular, much research has been done on dyeing synthetic fibers with disperse dyes in solvent systems with perchloroethylene as the main solvent. However, dyeing performance superior to that achieved with water has not been achieved, and the method has not yet been put to practical use.

[0005] Although perchloroethylene has been used effectively as a dry cleaning solvent, it is being phased out due to stricter international environmental regulations. In response to this elimination, decamethylcyclopentasiloxane (D5) and dibutoxymethane (K4) are expected to be added as alternative solvents for next-generation dry cleaning. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Akira Katayama et al., "Dyeing of Polyester with Disperse Dyes from Perchloroethylene," Seni Gakkaishi Journal, 1971 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved is that no waterless dyeing technology has been established that has a small environmental impact and is practically and industrially effective and useful in dyeing polyester with disperse dyes. [Means for solving the problem]

[0008] The present invention is characterized by the use of a specific next-generation cleaning solvent as a medium for the dye used in dyeing, in establishing an anhydrous dyeing technique to solve the above problems. [Effects of the Invention]

[0009] The method for producing dyed polyester products of the present invention uses a specific next-generation dry cleaning solvent, which has the advantages of requiring less energy than conventional dyeing processes, not using water, reducing the environmental impact, and not requiring dispersants, auxiliaries, etc. In addition, the solvent is relatively easily and inexpensively available on the market. [Brief explanation of the drawings]

[0010] [Figure 1] Figure 1 is an explanatory diagram showing the staining results when the concentration of the staining solution was changed (Example 1). [Figure 2] Figure 2 is an explanatory diagram showing the staining results when the concentration of the staining solution was changed (Example 2). [Figure 3] Fig. 3 is an explanatory diagram showing the dyeing results when the liquor ratio of the dye solution is changed (Example 3). [Figure 4] Fig. 4 is an explanatory diagram showing the dyeing results when the liquor ratio of the dye solution was changed (Example 4). [Figure 5]Fig. 5 is an explanatory diagram showing the dyeing results when the dyeing temperature was changed (Example 5). [Figure 6] Fig. 6 is an explanatory diagram showing the dyeing results when the dyeing temperature was changed (Example 6). [Figure 7] Figure 7 is an explanatory diagram showing the staining results when staining changed over time (Example 7). [Figure 8] Figure 8 is an explanatory diagram showing the staining results as the staining time changed (Example 8). DETAILED DESCRIPTION OF THE INVENTION

[0011] The polyester used is a polymer compound obtained by condensation polymerization of a polycarboxylic acid and a polyhydric alcohol, such as polyethylene terephthalate made from terephthalic acid and ethylene glycol. Preferred types of polyester are polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polytributylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, more preferably polyethylene terephthalate, polytrimethylene terephthalate, and polyethylene naphthalate, and most preferably polyethylene terephthalate. The molecular weight of the polyester is preferably 10,000 to 20,000 in number average molecular weight, and more preferably 12,000 to 18,000.

[0012] When polyester is used as a fiber, it can be either a staple fiber or a filament, and regardless of its form, it can be one-dimensional, such as a thread, two-dimensional, such as a fabric or film, or three-dimensional, processed into various three-dimensional shapes. The fabric can be woven, knitted, or nonwoven. When considering piece dyeing, fabric is preferred, and woven fabric is most preferred, with plain weave being the most desirable.

[0013] Any disperse dye can be used as long as it can be used to form a dyeing solution together with the medium for ordinary polyester dyeing. The meaning of "disperse" in disperse dye here is that when water is used as the main component of the dyeing solution, the disperse dye used is hardly soluble and remains dispersed in the aqueous medium. On the other hand, when the specific next-generation dry cleaning solvent used in the present invention is used as the medium, the solubility of the disperse dye tends to increase compared to aqueous media, and there may be cases where the dispersed state is not necessarily the main state. However, to avoid confusion, in the present invention, even if the disperse dye ultimately dissolves to a large extent, it will be referred to as a disperse dye.

[0014] Disperse dyes that can be used can be classified according to their chemical structure, and include benzene azo dyes (monoazo and disazo dyes), heterocyclic azo dyes (thiazole azo, benzothiazole azo, pyridone azo, pyrazolone azo, thiophene azo, etc.), anthraquinone dyes, and condensation dyes (quinophthalone, styryl, coumarin, etc.). Disperse dyes that can be preferably used are benzene azo dyes (monoazo and disazo dyes) and heterocyclic azo dyes (benzothiazole azo, pyridone azo, etc.), and more preferably benzene azo dyes (monoazo dyes) and heterocyclic azo dyes (benzothiazole azo dyes).

[0015] The specific next-generation cleaning solvent used as a medium constituting a part of the dye bath is at least one compound selected from the group of compounds represented by (Chemical Formula 1) or (Chemical Formula 2).

[0016] In the group of compounds represented by Chemical Formula 1, each R is preferably an alkyl group, more preferably an alkyl group having 1 to 10 carbon atoms, and most preferably an alkyl group having 1 to 3 carbon atoms. The alkyl group referred to here may be substituted with other elements or unsaturated bonds, etc., to the extent that it does not affect the properties of the medium in realizing the present invention. n is preferably a positive integer of 1 to 10, more preferably a positive integer of 1 to 5, and most preferably a positive integer of 1 to 3.

[0017] Specific examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane, with decamethylcyclopentasiloxane being the most preferred.

[0018] In the group of compounds represented by Chemical Formula 2, l, m, and n are each preferably a positive integer of 1 to 10, more preferably a positive integer of 1 to 5, and most preferably a positive integer of 1 to 3. These l, m, and n may be the same or different. Preferred examples include diethoxymethane, dipropoxymethane, dibutoxymethane, bis(pentyloxy)methane, 1,3-dimethoxypropane, and 1,2-dimethoxyethane.

[0019] The compound represented by Chemical Formula 2 may have a branched alkyl chain substituted or unsubstituted with other atoms, such as 1,1-diethoxyethane or bis(tert-pentyloxy)methane, on the carbon of its main chain, as long as the effect of the present invention is not impaired.

[0020] The compound represented by Chemical Formula 2 is most preferably a dialkoxymethane compound in which m is 1. Specific examples include diethoxymethane, dipropoxymethane, dibutoxymethane, and bis(pentyloxy)methane, and among these, dibutoxymethane is the most preferable.

[0021] Incidentally, the compound represented by (Chemical Formula 1) may also be a compound represented by the following (Chemical Formula 3). Here, R1 to R6 are preferably alkyl groups, more preferably alkyl groups having 1 to 10 carbon atoms, and most preferably alkyl groups having 1 to 3 carbon atoms. The alkyl groups referred to here may be substituted with other elements or unsaturated bonds, etc., to the extent that this does not affect the properties of the medium in realizing the present invention. n is preferably a positive integer of 1 to 10, more preferably a positive integer of 1 to 5, and most preferably a positive integer of 1 to 3.

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] Next, the method for dyeing the polyester sample of the present invention will be described. First, the dyeing solution is made by mixing the disperse dye and the next-generation dry cleaning solvent. In this case, the combination of these two components affects the distribution ratio of the disperse dye in the solution state and the dispersed state in the dyeing solution.

[0026] The prepared dye solution is transferred to a suitable container and the polyester sample is added to form a dye bath. Although an open dye bath may be used, a closed system is preferable because polyester dyeing generally requires relatively high temperatures. The concentration of the disperse dye in the dye bath, the bath ratio, dyeing time, and dyeing temperature affect the finished dyed state of the dyed polyester sample. In industrial applications, existing devices for preventing uneven dyeing may be employed, and in laboratories, it is desirable to shake the dye bath itself.

[0027] Since the present invention employs anhydrous dyeing, one of the surprising features of the present invention is that it does not require so-called dispersants or auxiliaries that are generally used in ordinary aqueous medium systems. However, there is still room for incorporating these agents depending on the distribution ratio between the solution state and the dispersion state of the disperse dye in the dyeing solution to be employed.

[0028] The concentration of the disperse dye in the dyeing solution used in the present invention will be explained below. Here, the "concentration" is defined as the weight of the disperse dye divided by the weight of the fabric to be dyed (expressed as % owf). In carrying out the present invention, the concentration is not limited to a particular one, but for example, 1.0% owf to 10.0% owf is preferable, 2.0% owf to 8.0% owf is more preferable, and 4.0% owf to 8.0% owf is most preferable.

[0029] The liquor ratio of the dye bath used in the present invention will be explained below. Here, the definition of "liquor ratio" is the ratio of the weight of the fabric to be dyed to the weight of the next-generation dry cleaning solvent. In carrying out the present invention, the liquor ratio is not limited to a specific one. For example, the ratio of "fabric weight: next-generation dry cleaning solvent" may be 1:2 to 1:100, preferably 1:5 to 1:80, more preferably 1:7 to 1:60, and most preferably 1:7 to 1:30.

[0030] The temperature of the dye bath employed in the present invention will now be described. Although the present invention is not limited to a specific temperature range, a temperature of about 130°C, which is generally used for dyeing polyester, is sufficient. Specifically, for example, a temperature of 90°C to 150°C is preferred, more preferably 100°C to 140°C, and most preferably 120°C to 140°C is desirable. The dye bath may be heated to a predetermined temperature from the beginning and maintained at that temperature for a predetermined period of time, or may be started at a low temperature and gradually increased in stages or continuously to the target temperature.

[0031] The dyeing time employed in the present invention will now be described. Although the present invention is not limited to a specific temperature range, the brightness can be controlled from light to dark colors by varying the dyeing time. At a temperature of around 130°C, which is generally used for dyeing polyester, the dyeing time is preferably 5 to 140 minutes, and more preferably 30 to 120 minutes.

[0032] The methods for measuring and evaluating two dyeing states ("evaluation of dyeability" and "evaluation of dye fastness") for "dyed polyester samples" (hereinafter referred to as "dyed fabric") are described below. Note that although fabric (two-dimensional sample) is used as the polyester sample here, appropriate sample preparation also makes it possible to measure and evaluate yarn (one-dimensional sample) and various other three-dimensional shapes (three-dimensional sample). The dyed fabric was thoroughly washed with a neutral detergent to remove any disperse dye remaining on the surface without being dyed.

[0033] For the "evaluation of dyeability," the spectral reflectance of the dyed fabric obtained was measured from 360 nm to 740 nm using a spectrophotometer CM-3600d (Konica Minolta), and the color density was evaluated by converting it into a Total K / S value, which is an index of the amount of dye absorbed, using the Kubelka-Munk equation.

[0034] For the "dyeing fastness evaluation," in order to confirm the practicality of the dyed fabric, the following four types of dyeing fastness tests were conducted after reduction washing. For the reduction washing, the dyed test fabric and detergent (a mixture of hydrosulfite 2g / L, soda ash 2g / L, and detergent scorrol 2cc / L) were placed in a stainless steel pot in a bath ratio of 1:30, just like the dyeing test, and treated in a dyeing tester at 80°C for 20 minutes. -Friction resistance: JIS L 0849 friction tester type 2 Lightfastness: JIS L 0842 carbon arc (third exposure method) Washing fastness: JIS L 0844 (A-2 method) Sweat fastness JIS L 0848

[0035] Examples are shown below, but the present invention is not limited to these. (Example 1) to (Example 8) show the conditions and results of the "evaluation of dyeing properties" method when the parameters, concentration, bath ratio, temperature, and time are varied. The reagents, samples, and equipment used in (Example 1) to (Example 8) are as follows, unless otherwise specified. ·Specific next-generation cleaning solvents: Example 1.3.5.7: Decamethylpentasiloxane (referred to as D5 in the table) (Tokyo Chemical Industry Co., Ltd.) Example 2.4.6.8: Dibutoxymethane (referred to as K4 in the table) (Tokyo Chemical Industry Co., Ltd.) Disperse dyes: Disperse dyes for polyester Red dye: Sumikaron Red S-BL (Sumitomo Chemical) Blue dye: Sumikaron BlueE-FBL (Sumitomo Chemical) Yellow staining; kayalon Microester Yellow AQ-LE (Nippon Kayaku) Test cloth: 100% polyester taffeta cloth, 10 x 30 cm (Shikisensha Co., Ltd., basis weight 63.3 g / m², Thickness 0.15mm, warp thread density 38.5 threads / cm, weft thread density 32.5 threads / cm) Dyeing tester: MINI-COLOUR (Texam Giken, heated solvent: polyethylene glycol)

[0036] Under the conditions shown below, the test cloth, disperse dye, solvent, and five stainless steel balls were placed in a stainless steel pot with a diameter of 75 x 110 m and a capacity of 440 ml, and the pot was set in a testing machine with a rotation speed of 35 rpm, and dyeing was carried out at high temperature and high pressure. After dyeing, the pot was washed with neutral detergent and water and air-dried. The spectral reflectance of the dyed fabric obtained was measured from 360 nm to 740 nm using a spectrophotometer CM-3600d (Konica Minolta), and the color density was evaluated by converting it into a total K / S value, which is an index of the amount of dye absorbed, using the Kubelka-Munk equation. Example 1

[0037] Dyeing was carried out under the following conditions using three types of disperse dyes, red, blue and yellow, at varying concentrations, to obtain dyed fabrics for each dye. · Specific next-generation cleaning solvent: Decamethylpentasiloxane ·Dye concentration (% owf): 1.0, 2.0, 4.0, 6.0, 8.0 (Further experiments were conducted using Kayalon Microester Yellow AQ-LE, which exhibits a yellow color, at 0.25, 0.5, and 1.0% owf.) ·Bath ratio: 1:15 Dyeing temperature: Preheat at 60°C for 15 minutes, then increase the temperature to 130°C over 30 minutes Dyeing time: 60 minutes (130℃) As a result, it was found that the dyeing rate increased with increasing concentration of all three disperse dyes. Therefore, it was clear that the dyeing was successful (see Figure 1). Example 2

[0038] The same procedure as in Example 1 was repeated except that the specific next-generation cleaning solvent was changed to dibutoxymethane (see Figure 2). Example 3

[0039] Under the following conditions, dyeing was carried out using three types of disperse dyes, red, blue and yellow, while varying the bath ratio of the polyester sample to the dye bath, to obtain dyed fabrics for each sample. · Specific next-generation cleaning solvent: Decamethylpentasiloxane ·Dye concentration (% owf): 4.0 ·Bath ratio: 1:7, 1:15, 1:30, 1:60 (The experiment was limited to only Kayalon Microester Yellow AQ-LE, which produces a yellow color, at three ratios: 1:7, 1:15, and 1:30.) Dyeing temperature: Preheat at 60°C for 15 minutes, then increase the temperature to 130°C over 30 minutes Dyeing time: 60 minutes (130℃) As a result, no significant dependency on the liquor ratio was observed, and effective dyeing was observed with all three types of disperse dyes. Normally, it is known that as the liquor ratio increases, the probability that the dye in the dye bath will penetrate into the fiber decreases, resulting in a decrease in the rate of exhaustion. In this study, no clear dependency on the liquor ratio was observed, but a tendency for the rate of exhaustion to decrease was confirmed when the ratio was 1:30 or higher (see Figure 3). Example 4

[0040] The same procedure as in Example 3 was repeated except that the specific next-generation cleaning solvent was changed to dibutoxymethane. However, the liquor ratio (1:60) was not used for all three dyes (see Figure 4).

[0041] From the results of (Example 3) and (Example 4), even at a low liquor ratio of 1:7, dyeing was sufficiently uniform without uneven dyeing. Therefore, in consideration of the effective use of the limited reagents available, dyeing experiments were carried out under the conditions of (Example 5) to (Example 8) using a liquor ratio of 1:7. Example 5

[0042] Dyeing was carried out using three types of disperse dyes (red, blue, and yellow) under the following conditions, varying the temperature rise conditions of the dye bath, to obtain dyed fabrics for each dye. · Specific next-generation cleaning solvent: Decamethylpentasiloxane ·Dye concentration (% owf): 4.0 ·Bath ratio: 1:7 Dyeing temperature: Preheat at 60°C for 15 minutes, then increase the temperature to 100°C, 110°C, 120°C, 130°C, and 140°C. Dyeing time: 60 minutes (at each temperature) As a result, the dye exhaustion rate increased with increasing dyeing temperature for all three disperse dyes. Sufficient dyeing to deep shades was achieved at dyeing temperatures up to 140°C. It was also confirmed that sufficient dyeing was possible even at around 130°C, the dyeing temperature for general polyester (see Figure 5). Example 6

[0043] The same procedure as in Example 5 was repeated except that the specific next-generation cleaning solvent was changed to dibutoxymethane (see Figure 6). Example 7

[0044] Under the following conditions, dyeing was carried out using three types of disperse dyes: red, blue, and yellow, with varying dyeing times, to obtain dyed fabrics for each dye. · Specific next-generation cleaning solvent: Decamethylpentasiloxane ·Dye concentration (% owf): 4.0 ·Bath ratio: 1:7 Dyeing temperature: Preheat at 60°C for 15 minutes, then increase to 130°C Dyeing time: 15 minutes, 30 minutes, 60 minutes, 120 minutes As a result, the dye exhaustion rate increased with increasing dyeing time for all three disperse dyes. It was confirmed that at a dyeing temperature of 130°C for a typical polyester, it is possible to adjust the color from light to dark by changing the dyeing time (see Figure 7). Example 8

[0045] The same procedure as in Example 7 was repeated except that the specific next-generation cleaning solvent was changed to dibutoxymethane (see Figure 8).

[0046] The relationships between the above-mentioned concentrations, liquor ratios, temperatures, and times are summarized in Table 1. The obtained dyed fabric was dyed evenly and uniformly with all three disperse dyes, from light to dark colors.

[0047] [Table 1]

[0048] Next, in Example 9, the conditions for the "color fastness evaluation" method and the results are shown. Example 9

[0049] To confirm the practicality of the dyed fabrics, we evaluated their color fastness. Three samples, each dyed particularly darkly, were subjected to reduction washing and then to the following color fastness tests. These samples were dyed at an 8.0% owf dye concentration (1:15 bath ratio, 130°C dyeing temperature, 60-minute dyeing time) and three samples dyed for 120 minutes (4.0% owf dye concentration, 1:7 bath ratio, 130°C dyeing temperature). The reduction washing was performed by placing the dyed test fabrics and detergent (a mixture of 2 g / L hydrosulfite, 2 g / L soda ash, and 2 cc / L Scoral detergent) in a stainless steel pot in a bath ratio of 1:30, and then processing them in a dyeing tester at 80°C for 20 minutes. As a result, for both of the two specific next-generation cleaning solvents (D5 and K4) used this time, the results were almost the same for the two dyeing conditions, the sample with a dye concentration of 8.0% owf (bath ratio 1:15, dyeing temperature 130°C, dyeing time 60 minutes) which dyed well and deeply, and the sample with a dyeing time of 120 minutes (dye concentration 4.0% owf, bath ratio 1:7, dyeing temperature 130°C), as shown below. - The rub fastness of all three dyes was grade 4-5 or higher both in dry and wet conditions. All three colors were grade 4 or above in light fastness. - In terms of washing fastness, all three dyes were graded 4-5 or higher for discoloration and staining on white fabric. In terms of sweat fastness, both in acidic and alkaline conditions, the three dyes were all grades 4-5 or higher in terms of discoloration and staining on white fabric. All of these showed good results.

[0050] The color fastness to rubbing is shown in Table 2 (using D5) and Table 3 (using K4). (Color density 8%, dyeing time 60 minutes)

[0051] [Table 2]

[0052] [Table 3]

[0053] The color fastness to rubbing is shown in Table 4 (using D5) and Table 5 (using K4). (Color density 4%, dyeing time 120 minutes)

[0054] [Table 4]

[0055] [Table 5]

[0056] The color fastness to light is shown in Table 6 (using D5) and Table 7 (using K4).

[0057] [Table 6]

[0058] [Table 7]

[0059] The color fastness to washing is shown in Table 8 (using D5) and Table 9 (using K4). (Color density 8%, dyeing time 60 minutes)

[0060] [Table 8]

[0061] [Table 9]

[0062] The color fastness to washing is shown in Table 10 (using D5) and Table 11 (using K4). (Color density: 4%, dyeing time: 120 minutes)

[0063] [Table 10]

[0064] [Table 11]

[0065] The color fastness to sweat is shown in Table 12 (using D5) and Table 13 (using K4). (Color density: 8%, dyeing time: 60 minutes)

[0066] [Table 12]

[0067] [Table 13]

[0068] The color fastness to sweat is shown in Table 14 (using D5) and Table 15 (using K4). (Color density: 4%, dyeing time: 120 minutes)

[0069] [Table 14]

[0070] [Table 15] [Industrial Applicability]

[0071] According to the present invention, since substantially no water is used in the dye bath, it is possible to provide an effective means for solving the problems of environmental load and wastewater treatment in the polyester fiber dyeing industry. [Explanation of symbols]

[0072] none

Claims

1. A method for producing dyed polyester, characterized in that when dyeing polyester with a disperse dye, a specific next-generation dry cleaning solvent used as a medium constituting a part of a dye bath is at least one compound selected from the group of compounds represented by (Chemical Formula 1) or (Chemical Formula 2). 【Chemical 1】 【Chemistry 2】

2. 2. The method for producing dyed polyester products according to claim 1, wherein the specific next-generation dry cleaning solvent is at least one low-molecular-weight cyclic siloxane compound selected from the group of compounds represented by (Chemical Formula 1).

3. 2. The method for producing dyed polyester products according to claim 1, wherein the specific next-generation dry cleaning solvent is at least one alkoxyalkane compound selected from the group of compounds represented by (Chemical Formula 2).

4. 3. The method for producing a dyed polyester product according to claim 2, wherein in the compound group represented by (Chemical Formula 1), each R is an alkyl group having 1 to 10 carbon atoms that may be the same as or different from any other R, and n is a positive integer of 1 to 10.

5. 5. The method for producing dyed polyester products according to claim 4, wherein the specific next-generation dry cleaning solvent is at least one low-molecular-weight cyclic siloxane compound selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane.

6. 4. The method for producing a dyed polyester product according to claim 3, wherein in the compound group represented by (Chemical Formula 2), l and n are each a positive integer of 1 to 10, and m is 1, which is an alkoxyalkane compound.

7. 7. The method for producing dyed polyester products according to claim 6, wherein the specific next-generation dry cleaning solvent is at least one alkoxyalkane compound selected from diethoxymethane, dipropoxymethane, dibutoxymethane, and bis(pentyloxy)methane.

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