JP5260856B2 - Method of dyeing cotton indigo dyed articles with natural indigo - Google Patents

Description

The present invention relates to a method for dyeing cotton indigo-dyed fabrics, fabrics, clothes, and other indigo-dyed articles using natural indigo .

Indigo products are widely distributed as jeans, in particular, has high commercial value of indigo dyeing products of cotton by natural indigo, when compared to reactive dyes used in the recent cotton dyeing, of cotton Senshokuji by natural indigo It has the disadvantage that the dye absorbency is low and a thick dye solution is left after dyeing. For this reason, the waste liquid after dyeing causes environmental pollution, necessitates countermeasures, and necessitates useless dyes.

  As is well known, indigo dyeing is a typical dyeing method, and it is a traditional dyeing method and a method widely used in modern industries. However, compared to the new dyeing technology, the dye utilization rate is extremely low, and the proportion of undyed dye flowing into the washing wastewater after washing after dyeing is large, so the basic unit is large and wastewater treatment costs are high. It is the current situation that it operates while holding.

  When performing indigo dyeing, indigo, which is an insoluble indigo dye, is reduced to produce an alkaline aqueous solution-soluble Ryu coin jig, and the fiber is immersed in the Ryu coin jig solution so that it is absorbed. Exposed to oxidize and insolubilize Ryucoinjigo to fix the indigo. At this time, Ryucoin jigo that has not been absorbed by the fibers is also oxidized by oxygen absorbed into the dye liquid from the air by stirring, and suspended in the dye liquid in a state where it cannot be dyed. A part of the insolubilized indigo returns to the ryu coin jig by the action of the reducing agent, but in the subsequent steps, most of the indigo adheres to the fibers as dirt and is removed from the dyeing bath, causing a large amount of dye loss.

  In the case of dyeing chemical fibers such as acetate or synthetic fibers with disperse dyes, it is a well-known technique to add a surfactant to the dyeing bath, but it is known that the hue of the dyed product changes as a result. Not. In natural fibers, the surfactant is usually applied or added after dyeing, and is not used as a means for greatly changing the hue or fastness of the dyed product.

  Patent Document 1 also describes the use of a surfactant for the treatment of denim fabric after dyeing with indigo. In this method, cellulase, heat-swollen pearlite and buffering agents are used in contacting the fabric with an effective amount of cellulolytic enzyme and thermally expanded pearlite to impart a local change in the color density of the surface of the dyed fabric in an aqueous medium. And optionally a surfactant or chelating agent as a dispersant.

  Non-Patent Document 1 is a research report on the development of vat dyeing technology for cotton / polyester blended yarns. Here, a case where a surfactant is added to an indigo dyeing bath is described, but the temperature at which only cellulose fibers are dyed is described. This is a disclosure of a technique for continuously dyeing indigo dyes into cotton / polyester blend yarns in a range.

JP 9-503032 gazette Hiroshima Prefectural Tobu Industrial Technology Center Research Report No. 15 (2002.5.31)

Cotton indigo dyeing with natural indigo has a very low dye utilization rate compared to the new dyeing technology, and a large proportion of undyed dye flows into the washing wastewater after washing after dyeing. There is a problem with high processing costs. The present invention is to solve such drawbacks of indigo dyeing.

Indigo dyed articles have slightly different hues depending on the dyeing conditions, and there are differences that cannot be explained at all by differences in the amount of dyeing. If this phenomenon can be utilized, a product having a wide range of variations other than color intensity can be obtained from a single dye. Conventionally, this phenomenon has been the cause of the difficulty of management as the instability of cotton indigo dyeing with natural indigo . The present invention aims to produce products of various hues using this phenomenon. .

Indigo suspended in the dye bath is attached to the fiber and taken out. However, since it is not absorbed inside the fiber, it does not exist stably with respect to external forces. Conventionally, textile products dyed with indigo are liable to fall off due to friction, and particularly have a problem of low fastness to wet friction. Another object of the present invention is to improve wet fastness of cotton dyeings with natural indigo .

Furthermore, when dyeing using natural indigo, when stained with less dyebath of indigo content, but it is known that different hues can be obtained from the indigo dyeing for dyeing synthetic indigo at high concentrations, high concentrations In dyeing with, a large amount of indigo is generated in the dyeing bath when it is built, and it is difficult to control its content, so the desired hue cannot be obtained, and the dye is lost by adhering to the dyed product Therefore, there was a problem with many losses, and a solution was sought. Another object of the present invention is to reduce such indigo loss.

As described above, the problem to be solved by the present invention is to diversify the hue in cotton indigo dyeing with natural indigo , to increase the dye absorption rate, thereby reducing stains in dyeing drainage and reducing the basic unit of dye. To achieve cost savings.

In the indigo dyeing process of cotton, which is called “building” in indigo dyeing, in the indigo dyeing process of cotton, a fermentation component or a reducing agent that forms the built dyeing bath and an alkali added for pH control. In addition, the method for dyeing indigo dyed articles is characterized in that a surfactant is added to the building dye bath and indigo dyeing is performed. Furthermore, in this indigo dyeing process, a dyeing method for indigo dyeing articles was proposed in which dyeing was performed while flowing a gas with low oxygen on the surface of the dye bath. That is, the atmosphere around the surface of the dye bath is replaced with a non-oxidizing gas from before and after the dye bath is built by replacing it with a non-oxidizing gas such as nitrogen or carbon dioxide. In the case of the present invention, as the non-oxidizing inert gas, the carbon dioxide gas is heavier than the nitrogen gas, so that it is easy to use.

  Most of the indigo particles suspended in the indigo liquid are not the raw material indigo that remained when the indigo was built, but the oxygen contained in the air mixed in the dyeing bath during the dyeing process. It is produced by oxidation of Ryucoinjigo and insolubilization. Surfactants have been found to be effective in reducing the amount of indigo particles produced in such dye baths. The mechanism of oxidation suppression is not clear, but the blue color of indigo disappears from the dye bath and the dirty yellow color of Ryu coin jigo appears, which is due to the inhibition of oxidation of Ryu coin jig in the bath Probability is high. It is highly possible that the surfactant collected on the surface of the bath forms a film and obstructs oxygen permeation.

The surfactant preferably used in the present invention may be of a type usually used in detergents and lubricants, where one end of a linear molecule is a hydrophilic group and the remainder is a hydrophobic group. A hydrophobic group at the center and a hydrophilic group at both ends (HLH type), or conversely, a hydrophilic group at the center of the molecule and a hydrophobic group at both ends (LH) -L type), anionic or nonionic active agents or compositions thereof are preferred. The surfactant to be added is preferably an anionic surfactant or a nonionic surfactant, but these can be used alone or in combination. Cationic surfactants interfere with the growth of microorganisms, so it is not preferable to use them when fermenting spiders (“sukumo”, fermented green leaves of plants, etc. ) by fermentation, but hydrosulfite It can be used when it is built with a reducing agent such as glucose, aldehydes, and starch syrup.

  Specifically, in the HLH type, a preferable surfactant is a nonionic surfactant having various properties of a block polymer type obtained by addition polymerization using polypropylene glycol as a lipophilic group and ethylene oxide as a hydrophilic group at both ends thereof. Agents. In addition, a polyethylene glycol ester of a long chain ω dibasic acid is also preferable. Also, L-H-L type nonionic surfactants include polyethylene glycol dilaurate, and anionic surfactants include phosphate esters such as alkyl phosphate diesters, alkyl ether phosphate diesters, alkyl allyl phosphate diesters, or their triesters. Examples thereof include salt mixed activators, alkylbenzene sulfonates (diester type), dialkyl sulfosuccinate anion activators, and funnel oil. In funnel oil, a chain of ricinoleic acid extends in three directions from the center of glyceride, and a sulfone group is bonded in the middle to form a hydrophilic group portion. Hydrophobic groups are at the three ends and the center of the molecule. A part of ricinoleic acid is detached from glycerin during the sulfonation process, but this type of surfactant also has two hydrophilic groups.

  Here, the addition amount of the surfactant needs to be not less than the concentration at which the interface is covered with the surfactant film-like structure, that is, the critical micelle concentration. The critical micelle concentration is small for low molecular weight surfactants and large for high molecular weight ones. In many cases, the molecular weight of a surfactant generally used is about 0.1% as a solution concentration. In the case of a solution extremely thicker than the critical micelle concentration, since the film-like material covering the interface is multilayered, it is presumed that a defective portion is formed, and the effect of the present invention tends to slightly decrease. The amount of these surfactants to be manifested is 0.05 to 5% by weight, preferably 0.01 to 3% by weight of the vat dyeing bath.

In denim dyed with natural indigo, it has been traditionally used that cellulolytic enzymes and thermally expanded pearlite can give local changes in the color density of the surface of the dyed fabric. However, it is not heard that the surfactant as a dispersant contributes to the change in color tone.

The present invention, when the Me cotton indigo by natural indigo, to start the fermentation with Sukumo (Sukumo), when erect while adding nutrients and indigo microbial liquor, or a reducing agent and an alkali to indigo in addition when the building to form a Ryuko body solution, by adding the surfactant, and stained with as much as possible the amount of fine indigo particles built dyeing bath is floating small state, natural This is a method for producing an indigo dyed cotton indigo article.

  It is presumed that oxidation of Ryucoin digo in the dye bath is caused by oxygen entering from the air. The reason why this reaction is strongly suppressed by the surfactant may be an apparent phenomenon, but suggests that the surfactant may act as an oxygen barrier. However, this is not a very simple phenomenon because the rate at which oxygen diffuses through surfactants that are considered liquids is generally estimated to be small. It seems necessary to consider the peculiarity of the membrane as a factor that reduces the overall diffusion coefficient of oxygen.

Such an oxidation inhibiting effect is rapidly lost when the dyebath is lost from the fiber surface. As a result, oxidation proceeds in the dye bath remaining on the fiber, and free indigo is produced. Since this is a factor of lowering the friction fastness of the product, it is desirable to remove it promptly. However, since there is a limit to the speeding up of the treatment in the actual process, it is preferable to immediately remove the Ryu coin jigo remaining in the liquid by squeezing the dye bath and immediately washing it with water for a short time. In this process, it is desirable to replace the surrounding atmosphere with a non-oxidizing gas such as nitrogen or carbon dioxide. In particular, in actual dyeing, it is more desirable to perform replacement while flowing a carbon dioxide gas heavier than air from before and after the dyeing bath is built.

In the present invention, the concentration of the already insolubilized indigo particles dispersed in the dye bath is reduced as much as possible by adding the above-described surfactant to the dye bath used for dyeing cotton indigo with natural indigo. This is a novel dyeing method capable of changing not only the dyeing amount and dyeing density of the dyed product but also the hue of the dyed article. The traditional building dye bath has a large amount of indigo particles dispersed in the dyeing process and a deep indigo color, but these particles already existed in the process of building the dye bath before the indigo was transformed into a ryuko. Unlike the particles, the particle size is large, and the hue after dyeing is slightly different depending on the amount of the particles. Fibers dyed in a dye bath with abundant abundance tend to shift to the purple side and become blackish. Under the condition that the particles are present in a large amount, when the dyed product is taken out from the bath, a large amount of particles adhere to the fiber surface, so that the friction fastness of the obtained dyed product becomes particularly low.

In this way, the purpose is to diversify the hue in cotton indigo dyeing with natural indigo , but there is an effect of increasing the absorption rate of the dye as another effect, which has various advantages. This has the effect of reducing stains in the dyeing effluent and reducing the basic unit of dye, which is also effective for cost reduction. That is, in the dyeing method of the present invention, there are very few indigo fine particles floating in the built-in dyeing bath, so there is an advantage that less dye is lost outside the system by washing after dyeing, and the basic unit of the dye is small. There is also an advantage that less dye is attached to the dyeing equipment and the factory is clean. In addition, less dye flows into the wastewater and is lost, and wastewater treatment costs can be reduced.

  Surfactants are considered to be assembled in a state where molecules are almost perpendicular to the gas-liquid and solid-liquid interface, and molecules are almost parallel to each other, and the structure is presumed to interfere with gas absorption. The degree is not clear. On the other hand, it is very difficult to actually measure the diffusion coefficient in the liquid film including the boundary film diffusion coefficient, and it is difficult to estimate the reaction suppression mechanism from the size. The phenomenon that the oxidation of Ryucoin digo is suppressed occurs not with specific surfactants but with surfactants with a wide range of chemical structures, both of which exhibit similar properties, so that surfactant molecules aggregate at the interface It is presumed that this is the cause of gas diffusion interference. It is thought that the surfactant gathers at the gas-liquid interface or the solid-liquid interface, and is arranged almost in parallel to form a film resembling a fine crystal. The angle between the molecular direction and the interface is constant depending on the surfactant. It is thought that. It is generally considered that when the amount of surfactant is large, the film is not disturbed, but is stacked in multiple layers and becomes thicker. Although it has a molecular arrangement close to a crystal, fluidity remains, so that it has a structure close to liquid crystal. As a result, it is likely that less indigo dye will be liberated as a result of the difficulty in passing gas through the tightly packed space of molecules.

In the dyeing method of the present invention, fabrics such as woven fabrics and other articles that are dyed cotton with natural indigo can be subjected to processing such as washing by conventional methods, which is effective for diversification of products. The effect similar to the processing of is shown. The dyed product of the present invention has a large amount of dye penetrating inside, and the decoloring speed by washing is smaller than that by the conventional method. However, by changing the processing time and conditions, the processing speed is almost the same as the conventional one. Can be adjusted.

In the dyeing solution of cotton indigo dyeing with natural indigo , 0.05% to 5% by weight, preferably 0.01% to 3% by weight of the surfactant of the built dyeing bath is mixed, and from the air By dyeing in a gas atmosphere with less oxygen while flowing heavy carbon dioxide gas, less indigo is generated as insoluble particles in the bath than in the dye bath according to conventional specifications. The absorption rate can be made higher than that of conventional dyeing methods . This not only improves the utilization rate of the dye, but in many cases, an article having a thicker hue can be produced as compared with the conventional method.

Further, it was recognized that the wet friction fastness of the dyed product of the present invention was generally higher than that of the dyed product of the conventional method. The hue is greener than the traditional indigo dyeing, and the difference depending on the fiber type is large. Silk and cotton are bluish, but rayon is purple. Because of these characteristics, the cotton dyed product according to the method of the present invention has an advantage of a hue different from that of conventional indigo dyeing. Since the amount of indigo suspended in the dye bath is small as described above, the effect of less waste water contamination can be obtained.

In order to improve the wet fastness of natural indigo-dyed articles, an attempt was made to seal a conventional dye-free bath with nitrogen gas. Specifically, a nitrogen gas introduction port and a discharge port are provided in the dyeing apparatus, and dyeing is performed so that oxygen does not dissolve in the dyeing bath. The disadvantage of this method is that the dyed product needs to be taken out into the air and transported when it is drained and washed after dyeing. Therefore, even if excellent performance is obtained in a small-scale test, sufficient improvement is not obtained in a practical test. In the dyeing using the surfactant according to the method of the present invention, if the surfactant is present on the surface of the dyed product, the oxidation of the Ryu coin jig is suppressed. do it. Since it is a well-known method to perform water washing and dehydration with a single device, the wet friction fastness can be improved by introducing an inert gas into this device. That is, since the surfactant is mixed in the natural indigo dyeing solution, the dyeing of the indigo dyeing article of the present invention is dyed in a gas atmosphere with less oxygen while flowing a non-oxidizing gas over the surface of the dyeing bath. The method comes to life. Here, as described above, since carbon dioxide gas is heavier than nitrogen gas, there is little ascending airflow in the vicinity of the mouth of the container generated by buoyancy due to specific gravity difference, and it is easy to use because air hardly flows.

  Examples that give the best results in the practice of the invention will now be described. Generally, even when other built-in dyes are mixed with indigo as dyes, when different dyes are mixed, the difference in dyeing speed is emphasized, and dyes with high speed are dyed deeply. There are many cases. When a reactive dye having a high dyeing speed or a direct dye is mixed and used, suppression of the formation of indigo components in the dye bath is observed. Dyes that can be mixed relatively easily are selenium dyes and sulfur dyes.

When dyeing a thick color containing indigo, such as dyeing warp in denim fabric, it is necessary to add a surfactant and then add a reducing agent and alkali directly to promote indigo conversion. preferable. Sukumo when making liquor is reduced by fermentation method (Sukumo) is desirably surfactant microorganisms are used to build a blue undegraded, used mainly nonionic surfactant of the polyether type It is preferable to do. Therefore, cationic activators are not preferred because they interfere with the growth of microorganisms.

  In the case of dyeing warp of denim fabric, the indigo concentration is set lower than before. Moreover, the basic unit of indigo is reduced by keeping the indigo concentration of the dyed liquid after squeezing low. The indigo concentration is preferably about 80% of the conventional level. In the following, the present invention will be described specifically with numerical values.

Example 1
Put distilled water 40 liters in inner volume 45 l, 40 ° C. caustic soda 3 g / l while maintaining, as will become sodium carbonate 40 g / l, after homogenization was charged with each drug, natural indigo (dry powder 1600 g of Sukumo) and 400 g of PEG1000 dilaurate, a nonionic surfactant, were added and homogenized. Hydrosulfite was mixed with this solution at 12 g / liter for 15 minutes, and indigo was converted into a ruco. In the system to which no surfactant was added, the liquid was colored dark amber, but this liquid showed a yellowish green turbid color.

  10 kg of cotton fabric was put into this liquid, dyed by slowly stirring for 30 minutes, pulled up, dehydrated, washed with water, and then subjected to air oxidation in a state of being hung on a hanger to cause color development. This dyed product has a total K / S of 536 at a wavelength of 400 to 700 nm, hue is more reddish than the comparative example (blank), and the fastness to wet friction is grade 3 and is significantly improved from the conventional indigo dyed product and the comparative example. It had been.

Example 2
Put 40 liters of distilled water in the same container as in Example 1 and put each chemical into 3 g / liter of caustic soda and 40 g / liter of sodium carbonate while maintaining the temperature at 40 ° C. Put dry ice in the basket to fill the space with carbon dioxide gas, add 1600g of natural indigo ( dry powdered smoky ) and 400g of non-ionic active agent PEG1000 dilaurate, and homogenize in non-oxidizing atmosphere I let you. This solution was mixed with hydrosulfite at 12 g / liter over 15 minutes to make Indigo Ryuco. The dyebath sampled at the start of dyeing showed a yellowish green turbid color.

  10 kg of cotton fabric was added to this liquid, and after slowly stirring and dyeing for 30 minutes, it was pulled up, dehydrated in a carbon dioxide atmosphere, washed with water, and then subjected to air oxidation in a hung state to develop color. This dyed product has a total K / S of 523 at a wavelength of 400 to 700 nm, a hue biased to a reddish color compared to the comparative example (blank), and the fastness to wet friction is grade 4 and significantly improved from the comparative example. The same value as that obtained by dyeing was obtained.

Example 3
When a dialkylsulfosuccinate anionic surfactant was used in place of the surfactant PEG1000 dilaurate of Example 1, a dyeing having excellent wet friction fastness was obtained. The obtained dyed product had a total K / S of 543, a hue that was slightly reddish and dark.

Example 4
When funnel oil was used in place of the surfactant PEG1000 dilaurate of Example 1, a dyed product having excellent wet friction fastness was obtained. In funnel oil, a chain of ricinoleic acid extends in three directions from the center of glyceride, and a sulfone group is bonded in the middle to form a hydrophilic group portion. Hydrophobic groups are the three ends and the central part of the molecule. The obtained dyed product had a total K / S of 399, the hue was slightly bluish, the color purity was high, and the color was slightly lightened.

Example 5
When an anionic surfactant, Actinol KP-100, manufactured by Matsumoto Yushi Seiyaku Co., Ltd. was used in place of the surfactant PEG1000 dilaurate of Example 1, a dyed product with excellent wet friction fastness was obtained. The obtained dyed product had a total K / S of 316, the hue was slightly bluish, the color purity was high, and the color was considerably lightened.

Example 6
When sodium alkylbenzene sulfonate was used as the surfactant, a dyed product with excellent wet friction fastness was obtained. The obtained dyed product had a total K / S of 325, a slightly strong bluish hue, and a slightly lighter color.

Example 7
When sodium alkylphosphate (average phosphorous alkylation degree 2.5) was used as the surfactant, a dyed product with excellent wet friction fastness was obtained. The obtained dyed product had a total K / S of 408, and the hue was slightly bluish.

Comparative Example Using the same apparatus as in Example 1, a dyeing solution was prepared by omitting only the addition of the surfactant. This method is a method used for conventional natural indigo dyeing. The resulting liquid had a dark amber color as usual. 10 kg of the same cotton fabric as in Example 1 was added to this solution, dyed in the same manner, dehydrated in a carbon dioxide atmosphere, washed with water, and then subjected to air oxidation in a state of being hung on a hanger to cause color development.

  This dyed product had a total K / S of 469 at a wavelength of 400 to 700 nm and a normal amber color. The fastness to wet friction was grade 2. Since the fastness was taken out from the dyeing liquid and kept in an inert gas atmosphere until dehydration, the fastness was superior to a dyed product obtained by a conventional method using no inert gas.

As is clear from the results of the above examples and comparative examples, in addition to the relatively high concentration of natural indigo, reducing agent, and alkali during the indigo building, a specific surfactant is allowed to coexist, thereby increasing the range. The indigo concentration can be adopted, and indigo dyeing of various hues can be performed.

Claims (4)

In addition to fermentation components or reducing agents and alkalis that form a built-in dyeing bath in the process of cotton indigo dyeing from the spiders that form the natural indigo silk, an anionic surfactant or nonionic surfactant or a mixture thereof by adding a surfactant consisting in making indigo, the dyebath surface Ai Kowata dyed products by natural indigo, which comprises dyeing from heavy in small gaseous oxygen while passing carbon dioxide gas atmosphere air Dyeing method. The method for dyeing cotton indigo dyed articles with natural indigo according to claim 1, wherein the surfactant has a hydrophilic group at the center of the molecule and a hydrophobic group at both ends. The method for dyeing cotton indigo dyed articles with natural indigo according to claim 1, wherein the surfactant has a hydrophobic group at the center of the molecule and a hydrophilic group at both ends. The method for dyeing cotton indigo dyed articles with natural indigo according to any one of claims 1 to 3, wherein the surfactant is added in an amount of 0.01 to 3% by weight of the built-in dyeing bath.