JP5938396B2 - Aramid fiber dyeing method - Google Patents

Description

The present invention relates to an aramid fiber dyeing method, and more particularly to a dyeing method capable of dyeing an aramid fiber to a practical dyeing concentration .

  The wholly aromatic polyamide fiber is also referred to as an aramid fiber, has high strength and high elastic modulus, is excellent in heat resistance, dimensional stability, chemical resistance, and the like, and is used for a wide range of applications as industrial fiber. This aramid fiber is composed of a para-aramid fiber (polyparaphenylene terephthalamide fiber, etc.) and a para-copolymerized aramid fiber (polyparaphenylene terephthalamide and 3,4'-oxydiphenylene) depending on the position at which the amide bond is attached to the aromatic ring. For example, copolymer fibers with terephthalamide) and meta-aramid fibers (polymetaphenylene isophthalamide fiber or copolymer fibers containing this as a main component).

  Para-aramid fibers are particularly strong and excellent in elastic modulus. They are widely used as protective materials such as bulletproof vests, wear materials such as brake pads, optical fiber reinforcements, and industrial materials such as ropes and nets that require particularly high strength. It is used. Para-copolymerized aramid fibers are used for the same applications as para-aramid fibers, but exhibit characteristics in applications that require chemical stability and fatigue resistance. For example, it is widely used for rubber reinforcements, ropes, civil engineering and building applications. On the other hand, meta-aramid fibers are particularly excellent in heat resistance, flame retardancy, chemical resistance, etc., and are widely used as various protective work clothes such as fire fighting clothes.

  These aramid fibers have a rigid molecular structure and high crystallinity, and a practical dyeing concentration cannot be obtained with the same dyeing method as general fibers. The fastness is not practically sufficient. Therefore, in actuality, mainly meta-aramid fibers are manufactured and used as original fibers (fibers made by adding a colorant in the stage before the spinning process). Since such an original fiber has a limited hue, there is a problem that it cannot sufficiently cope with the abundant hues required for various protective work clothes or new applications of aramid fibers. Further, in para-aramid fibers and para-copolymerized aramid fibers, fibers having a practical dyeing density such as black and navy blue, including original fibers, have not been produced industrially.

  On the other hand, special dyeing methods for dyeing aramid fibers have been studied. For example, a high-temperature high-pressure dyeing method using a carrier such as benzaldehyde, acetophenone or benzyl alcohol, or a solvent dyeing method in which high-temperature dyeing is performed in a polar solvent such as N, N-dimethylformamide, dimethyl sulfoxide or cyclohexanone. However, the dyeing method using these carriers or polar solvents at high temperatures is mainly a method of dyeing meta-aramid fibers, which is insufficient for dyeing para-aramid fibers or para-copolymerized aramid fibers. It was. Further, in dyeing meta-aramid fibers, dyeing methods using these carriers or polar solvents at high temperatures have problems such as dyeing unevenness of dyed articles, dimensional changes due to shrinkage, and deterioration of physical properties.

  Therefore, various new staining methods are currently being studied. For example, in Patent Document 1 below, aramid fibers are pretreated with concentrated sulfuric acid, neutralized, and then put into a dyeing bath while maintaining a predetermined moisture content without being dried, and dyed with a disperse dye or a cationic dye. A dyeing method has been proposed. Patent Document 2 below proposes a dyeing method for dyeing under a very high temperature condition of 300 to 400 ° C. using a part of a vat dye that is stable at high temperatures.

JP 52-37882 A JP 2010-59556 A

  By the way, the dyeing method of the above-mentioned patent document 1 can obtain a dyed material with abundant hues. However, the dyeing method of Patent Document 1 has a problem that the dye used is a disperse dye or a cationic dye, and the dyeing fastness, particularly the light fastness is poor. On the other hand, the dyeing method of Patent Document 2 uses a vat dye having good light fastness, but the dyeing temperature is very high, and the dyes that can be used for this are limited and abundant. There was a problem that the hue could not be handled sufficiently.

  Further, the dyeing method of Patent Document 2 has a problem that a special apparatus is required and the energy cost is increased. Furthermore, the dyeing method of Patent Document 2 is still insufficient for dyeing para-aramid fibers or para-copolymerized aramid fibers to a practical dye density. On the other hand, when the dyeing method of Patent Document 2 is applied to a meta-aramid fiber, since the treatment is performed at a temperature that greatly exceeds the glass transition point, there has been a problem that the physical properties of the fiber are greatly reduced.

In view of the above, the present invention is a dyeing method that can be applied to any of para-aramid fibers, para-copolymerized aramid fibers, and meta-aramid fibers. Dyed at a practical dyeing density required for various application developments, and the dyed aramid fiber does not cause uneven dyeing, dimensional changes, or significant deterioration in physical properties. fastness, and an object thereof is to particularly provide lightfastness a Senshokukata method good aramid fibers.

  In solving the above-mentioned problems, the present inventors, as a result of diligent research, adopted vat dyes or sulfur dyes with good light fastness to dye aramid fibers, and apply these dyes onto aramid fibers. It has been found that the above problems can be solved by combining the process and the process of treating the aramid fiber with a polar solvent, and the present invention has been completed.

That is, according to the method for dyeing aramid fibers according to the present invention, a water-insoluble dye selected from vat dyes (excluding solubilized vat dyes) or sulfur dyes is imparted to aramid fibers. A dye application step;
A solvent treatment step of treating the aramid fiber with a treatment solution containing a polar solvent;
After this solvent treatment step, it has a heat treatment step to heat treat the aramid fiber if necessary,
In each of the above steps, without using the vat dye or the agent for reducing or water-solubilizing the sulfur dye, or operation,
Four dyeing operations shown below,
Dyeing operation 1: Dye application step → Solvent treatment step,
Dyeing operation 2: solvent treatment step → dye application step,
Dyeing operation 3: Dye application step → Solvent treatment step → Heat treatment step
Dyeing operation 4: Solvent treatment step → heat treatment step → dye application step,
And at least one dyeing operation is provided once or more ,
The polar solvent is a value of solubility parameter ([delta]) is characterized by near Rukoto the range of 18~32 ^{(MPa) 1/2.}

Further, the method of dyeing aramid fibers according to the present invention, imparts According to the description of claim 2, the insoluble dye in water selected from aramid fibers (excluding solubilized vat dye) vat dyes or sulfur dyes A dye application step;
A solvent treatment step of treating the aramid fiber with a treatment solution containing a polar solvent;
After this solvent treatment step, it has a heat treatment step to heat treat the aramid fiber if necessary,
In each of the above steps, without using the vat dye or the agent for reducing or water-solubilizing the sulfur dye, or operation,
Four dyeing operations shown below,
Dyeing operation 1: Dye application step → Solvent treatment step,
Dyeing operation 2: solvent treatment step → dye application step,
Dyeing operation 3: Dye application step → Solvent treatment step → Heat treatment step
Dyeing operation 4: Solvent treatment step → heat treatment step → dye application step,
And at least one dyeing operation is provided once or more,
The polar solvent is selected from the group consisting of N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, benzyl alcohol, diethylene glycol, triethylene glycol, sulfuric acid, formic acid, lactic acid, and oxalic acid. And at least one kind.

Further, according to the description of claim 3 , the method of dyeing aramid fibers according to the present invention, the method of dyeing aramid fibers according to claim 1 or 2 ,
A pre-dyeing step performed before the dyeing method or a post-dyeing step performed after,
In the pre-dying step or the post-dying step, the aramid fiber is dyed with a dye other than a vat dye and a sulfur dye.

  According to the present invention, the present invention can be applied to any of para-aramid fibers, para-copolymerized aramid fibers, and meta-aramid fibers, and these aramid fibers can be dyed to a practical dyeing concentration. Further, according to the present invention, dyeing unevenness, dimensional change, or deterioration of physical properties does not occur greatly in the aramid fiber after dyeing. Further, since a vat dye or sulfur dye having good dyeing fastness, particularly light fastness, is used, the dyeing fastness, especially light fastness, of the dyed aramid fiber is improved.

  Further, by changing the use concentration and hue of the vat dye or sulfur dye to be used, it is possible to obtain a dyed product having abundant hues from light to dark. In particular, according to the present invention, para-aramid fiber or para-copolymerized aramid fiber, which has been considered difficult so far, can be dyed in an extremely dark color such as black or navy blue.

Here, as one method for evaluating extremely dark colors such as black and navy blue, L ^* a ^* b was standardized by the International Commission on Illumination (CIE) in 1976 and adopted in JIS Z8729 in Japan. ^* There is lightness (L ^* value) in the color system. This L ^* value is expressed in the range of 100 (white) to 0 (black), and it can be evaluated that the darker the color, the smaller the L ^* value.

For example, commercially available meta-aramid fibers or para-copolymerized aramid fibers have an L ^* value of 25 to 27 in an extremely dark color such as black or navy blue. Accordingly, in the present invention, it can be determined that the color is dark when the L ^* value is 38 or less, and it can be determined that the color is extremely dark when the L ^* value is 30 or less. In the present invention, not only the meta-aramid fibers but also the para-aramid fibers or the para-copolymerized aramid fibers can be dyed in a deep color or an extremely dark color by a dyeing method instead of an original deposition method.

  In addition, as a pre- and post-process of the aramid fiber dyeing method according to the present invention, a pre-dyeing process or a post-dying process using a dye other than a vat dye and a sulfur dye can be performed. By performing these dyeing steps, the fluff on the surface of the aramid fiber itself is more sufficiently dyed, and the dyeing quality and dyeing density are further improved. On the other hand, when the aramid fiber is a mixed fiber with other chemical fiber or natural fiber, by performing these dyeing steps, the hue of the aramid fiber and the other fiber can be unified, and the dyed product Dyeing quality and dyeing density are further improved.

Therefore, according to the present invention, color fastness of dyed dyeing, in particular good light fastness, can provide a Senshokukata method of aramid fiber having a hue rich practical dyeing concentration . This is effective for the development of new uses for aramid fibers.

  Examples of the aramid fiber dyed by the dyeing method according to the present invention include Twaron (registered trademark) of Teijin Limited and Kevlar (registered trademark) of DuPont Co., Ltd. as para-aramid fibers. As such, there is Technora (registered trademark) of Teijin Limited. On the other hand, there are CONEX (registered trademark) by Teijin Limited and Nomex (registered trademark) by Dupont Co., Ltd. as meta-aramid fibers.

  In the present invention, the form of the aramid fiber may be any form, and may be a fiber state such as a filament fiber or a staple fiber, or a filament yarn, a spun yarn, a woven fabric, a knitted fabric, a non-woven fabric, a rope It may be in the state of a fiber structure such as a net. Moreover, any of para-aramid fiber, para-copolymerized aramid fiber, or meta-aramid fiber may be used alone, or a mixed fiber of these may be used. Further, it may be a mixed fiber state of an aramid fiber and other chemical fiber or natural fiber.

In the present invention, the aramid fiber is dyed with a water-insoluble dye selected from vat dyes (excluding solubilized vat dyes) or sulfur dyes. These vat dyes or sulfur dyes are dyes having good dyeing fastness, and are particularly excellent in light fastness.

  Here, the vat dye is usually used for dyeing cotton and the like, and is originally a dye that is insoluble in water. However, it is reduced by a reducing agent such as sodium dithionite to form butanoic acid or leuco salt. It is adsorbed onto the fiber and then oxidized and dyed onto the fiber again as a water-insoluble dye.

  On the other hand, the sulfur dye is a dye containing a sulfur atom in the molecule and is usually used for dyeing cotton or the like. This sulfur dye is originally a water-insoluble dye, but it is reduced by a reducing agent such as sodium sulfide to become water-soluble and adsorbed to the fiber, and then oxidized to dye the fiber again as a water-insoluble dye. .

  However, in the present invention, the aramid fiber is dyed as a water-insoluble dye without reducing the vat dye or sulfur dye. The vat dye or sulfur dye does not have a strong affinity for dyeing aramid fibers as it is. Further, when the vat dye or sulfur dye is reduced to be water-soluble, the affinity for aramid fibers is further reduced.

  However, in the present invention, it is considered that the vat dye or the sulfur dye is attached to the aramid fiber by combining with a solvent treatment with a polar solvent for the aramid fiber. Furthermore, if heat treatment is performed as necessary after the solvent treatment, the dyeing property of vat dyes or sulfur dyes to aramid fibers may be further improved. However, at present, the dyeing mechanism of vat dyes or sulfur dyes on aramid fibers in the present invention is not clear.

Hereinafter, the aramid fiber dyeing method according to the present invention will be described with reference to each embodiment.
(1) 1st Embodiment The dyeing | staining method which concerns on this 1st Embodiment is the solvent provision which processes the aramid fiber by the dye provision process which provides a vat dye or a sulfur dye to an aramid fiber, and the process liquid containing a polar solvent. Process. The order of these dye application step and solvent treatment step is not particularly limited, but it is preferable to perform the solvent treatment step after the dye application step. In the first embodiment, first, a dye application step of applying a vat dye or sulfur dye to the aramid fiber in a non-reduced state is performed, and then the aramid fiber to which the vat dye or sulfur dye is applied is applied. A solvent treatment step of treating with a treatment solution containing a polar solvent is performed.

  In the first embodiment, these series of steps are collectively referred to as “staining operation 1”. The dyeing operation 1 (dye application step → solvent treatment step) may be performed only once, or may be repeated a plurality of times if necessary. By repeating this dyeing operation a plurality of times, darker aramid fibers can be obtained.

A. Dye provision process The dye used for dyeing | staining of cotton etc. can be used for the vat dye used at this dye provision process normally. In the present invention, it is preferable to use a super fine dye having an average dispersed particle size of several μm or less, preferably 1 μm or less in a state of being dispersed in a staining solution. Among these vat dyes, C.I. I. Vat Yellow 33, C.I. I. Vat Brown 1, C.I. I. Vat Red 1, C.I. I. Vat Violet 9, C.I. I. Vat Blue 4, C.I. I. Vat Blue 6, C.I. I. Vat Blue 20, C.I. I. Vat Green 1, C.I. I. Vat Green 3, C.I. I. Vat Black 8, C.I. I. More preferably, each dye such as Vat Black 25 is used.

  On the other hand, as the sulfur dye used in this dye application step, a dye usually used for dyeing cotton or the like can be used. Among these sulfur dyes, C.I. I. Sulfur Yellow 16, C.I. I. Sulfur Orange 1, C.I. I. Sulfur Red 6, C.I. I. Sulfur Blue 7, C.I. I. Sulfur Blue 15, C.I. I. It is more preferable to use each dye such as Sulfur Black 11.

  At the stage of applying the dye to the aramid fiber, the vat dye or the sulfur dye is not in a reduced state and is a water-insoluble dye. Therefore, a dyeing liquid in which a vat dye or a sulfur dye is dispersed in water is used for the dye application to the aramid fiber in the dye application process. This dyeing solution contains a vat dye or sulfur dye in a non-reduced dispersion state, and if necessary, a migration inhibitor is used in combination. Any method may be employed for the application of the dyeing liquid, and it may be simple immersing, immersing and squeezing, or applying by spraying or ink jetting.

  The aramid fiber to which the dyeing solution has been applied is then dried if necessary. The aramid fiber may be dried at any temperature, but usually it may be dried at a temperature of about 80 ° C to 120 ° C. Further, after the aramid fiber is dried, heat treatment (treatment different from the heat treatment step described later) may be performed at a higher temperature. Or you may make it perform the heat processing which served also as the aramid fiber to which the dyeing | staining liquid was provided at the temperature of about 120 to 200 degreeC or more.

  When this drying temperature is lower than 80 ° C., it takes time to dry the aramid fibers. On the other hand, when the treatment temperature is higher than 200 ° C., particularly higher than 280 ° C., the physical properties of the aramid fibers may be greatly deteriorated. In particular, in the case of meta-aramid fibers, heat treatment at a temperature exceeding the glass transition point causes a decrease in physical properties. In addition, when processed at an extremely high temperature, the vat dye or sulfur dye may be decomposed, and the hue changes greatly.

  On the other hand, the drying time may be appropriately selected depending on the type and form of aramid fibers and the drying temperature, and does not cause any particular problem. Usually, the drying time may be about 30 seconds to 30 minutes. For example, when the aramid fiber is a fabric, a drying time of about 1 to 10 minutes is preferable when the drying temperature is 105 ° C.

  At the stage of finishing this drying, the vat dye or sulfur dye is uniformly applied on the aramid fiber. However, aramid fibers are not completely dyed with vat dyes or sulfur dyes. However, at this stage, the vat dyes or sulfur dyes adhere to the aramid fibers with a certain degree of affinity even if they do not reach dyeing. Here, the reason why vat dyes or sulfur dyes adhere to aramid fibers is not clear, but these dyes adhere to the surface of aramid fibers by physical action such as intermolecular force in a non-reducing water-insoluble state. It is thought to do.

  Here, when the aramid fiber is in the form of a cloth, a series of treatments can be performed while the cloth is running in the longitudinal direction. In this case, the traveling aramid fiber fabric is first immersed in a bath filled with a dyeing solution. Subsequently, surplus dyeing liquid is squeezed from the aramid fiber fabric by a squeezing means such as mangle. In this way, an aramid fiber fabric to which a predetermined amount of dyeing liquid has been uniformly applied is obtained. Next, the aramid fiber fabric after squeezing is introduced into a heat treatment apparatus such as a pin tenter while running and dried.

B. Solvent treatment step The aramid fibers after the dye application step are put into the subsequent solvent treatment step without washing. In this solvent treatment step, aramid fibers are treated with a polar solvent. In the present invention, a polar solvent is widely interpreted and a substance having a polar functional group in the solvent molecular structure is meant. For example, as aprotic polar solvents among polar solvents, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, acetophenone, methyl ethyl ketone, acetophenone, N-butylphthalimide, N-isopropyl Examples thereof include phthalamide and N-methylformanilide. These aprotic polar solvents may be used alone or in combination of two or more, or may be used in combination with a protic polar solvent described below. Among these aprotic polar solvents, N-methylpyrrolidone, N, N--is a solvent that is unlikely to cause aramid fiber shrinkage or physical property deterioration and is particularly effective for dyeing vat dyes or sulfur dyes. Dimethylformamide, N, N-dimethylacetamide and dimethyl sulfoxide are preferred.

  Among polar solvents, protic polar solvents include sulfuric acids, formic acid, lactic acid, maleic acid, oxalic acid and other protic acids, 1-propanol, 1-octanol, benzyl alcohol, DL-β-ethylphenethyl alcohol, 2- Ethoxybenzyl alcohol, 3-chlorobenzyl alcohol, 2,5-dimethylbenzyl alcohol, 2-nitrobenzyl alcohol, p-isopropylbenzyl alcohol, 2-methylphenethyl alcohol, 3-methylphenethyl alcohol, 4-methylphenethyl alcohol, 2- Methoxybenzyl alcohol, 3-iodobenzyl alcohol, cinnamic alcohol, p-anisyl alcohol, benzhydrol, 2- (4-chlorophenoxy) ethanol, 2- (4-chlorophenoxyethoxy) ethanol , Alcohols such as 2- (dichlorophenoxy) ethanol, ethylene glycol, diethylene glycol, triethylene glycol, glycols such as PEG200, PEG400, PEG600, propylene glycol, polypropylene glycol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene Glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, propylene glycol monophenyl Examples include monoethers or monoesters of glycols such as phenyl ether, dipropylene glycol monophenyl ether, cellosolve, n-butyl cellosolve, and hydroxyethyl acrylate. These protic polar solvents may be used alone or in combination of two or more, or may be used in combination with the aprotic polar solvent described above. Among these protic polar solvents, benzyl alcohol, diethylene glycol, triethylene glycol, sulfuric acid are not particularly susceptible to shrinkage of the aramid fiber and physical properties, and are particularly effective for dyeing vat dyes or sulfur dyes. Formic acid, lactic acid and oxalic acid are preferred.

Further, the solubility parameter (δ) can be used as a quantitative index representing the polarity of the polar solvent used in the present invention. In the present invention, it is preferable to use a polar solvent having a solubility parameter value in the range of δ = 18 to 32 (MPa) ^1/2 . Furthermore, it is more preferable to use a polar solvent having a solubility parameter value in the range of δ = 19 to 28 (MPa) ^1/2 . Here, for example, the value of the solubility parameter of para-aramid fiber is assumed to be δ = 23 (MPa) ^1/2 (JE Mark, Physical Properties of Polymers Handbook. New York: Woodbury, 1996.). Accordingly, the solubility parameter value of the polar solvent is in the above range, and it is considered that the action of the polar solvent on the aramid fiber is caused by being close to the solubility parameter value of the aramid fiber. By this, the dyeing property to the aramid fiber of a vat dye or a sulfur dye improves, and the aramid fiber which has a more practical dyeing density can be obtained.

  These polar solvents may be used alone as described above, or two or more solvents may be mixed and used. Further, the concentration of the polar solvent used for the solvent treatment may be appropriately selected depending on the type, shape, and treatment temperature of the aramid fiber to be treated, but usually it is preferably 40 to 100% by weight, It is more preferable to contain 50 to 100% by weight. However, oxalic acid is usually a solid having crystal water and its solubility is small. Therefore, oxalic acid is preferably used as an aqueous solution of about 10% by weight.

  On the other hand, regarding the sulfuric acid used also in the manufacturing stage of para-aramid fiber, it is necessary to set the use concentration more narrowly. In this solvent treatment step, it is preferable to use an aqueous sulfuric acid solution having a concentration of 70% by weight to 90% by weight. Furthermore, it is more preferable to use a 75% by weight to 85% by weight sulfuric acid aqueous solution. Further, when the aramid fiber is mainly composed of a meta-aramid fiber, it is more preferable to use a sulfuric acid aqueous solution concentration of 75% by weight to 80% by weight.

  When the concentration of the polar solvent is in the above range, the staining concentration is within a relatively stable range, and even when the concentration of the polar solvent varies slightly, the staining concentration hardly changes greatly. Therefore, stable industrial production is possible when the concentration of the polar solvent is in the above-described range.

  Here, as the diluent for the polar solvent, any solvent compatible with the polar solvent to be used may be used, but water is generally used. In the case of a certain type of polar solvent such as N-methylpyrrolidone, a darker dyed product can be obtained by mixing a certain amount of water. On the other hand, if the concentration of the polar solvent is lower than the above range and the amount of water in the solvent treatment liquid increases, the vat dye or sulfur dye attached to the aramid fiber in the dye application step may fall out in the solvent treatment liquid. It is not preferable.

  The treatment temperature of the polar solvent may be appropriately selected depending on the type, shape and treatment time of the aramid fiber to be treated, but is usually treated at a temperature of 0 ° C to 70 ° C. Moreover, it is preferable that it is the temperature of 10 to 60 degreeC. However, when sulfuric acid is used, the temperature of the sulfuric acid aqueous solution may be 0 ° C. or higher and 50 ° C. or lower, and more preferably 0 ° C. or higher and 30 ° C. or lower.

  When the temperature of the polar solvent is in the above-mentioned range, the dyeing concentration is within a relatively stable range, and even when the temperature of the polar solvent is slightly changed, the dyeing concentration hardly changes. Therefore, stable industrial production is possible when the temperature of the polar solvent is in the above-described range. On the other hand, when the temperature of the polar solvent is higher than the above range, the physical properties of the aramid fiber may be deteriorated or extremely contracted. In addition, the dyeing density may change greatly due to slight fluctuations in the temperature of the polar solvent. This is presumably because the high-temperature polar solvent causes a large change in the molecular structure of the aramid fiber.

  The treatment time for the solvent treatment is appropriately selected depending on the concentration and temperature of the polar solvent, and is usually treated in a time of about 0.1 seconds to 30 minutes. Furthermore, the treatment time for the solvent treatment is preferably about 1 second to 5 minutes. Even if the processing time of the solvent treatment is about 1 second, the effect of the solvent treatment is maintained. Thus, when the processing time of the solvent treatment is about 1 second to 30 minutes, the dyeing density hardly changes even when the processing time is slightly changed, and the dyeing is performed at a practical dyeing density. can do.

  Thus, it is preferable that the processing time of the solvent treatment is controlled within a predetermined range. Therefore, it is preferable that the aramid fiber treated with the polar solvent is washed quickly. Moreover, when processing with a sulfuric acid, it is preferable to neutralize and wash rapidly. Here, the aramid fibers may be washed with water or hot water, but reduction washing may be performed to remove undyed vat dyes or sulfur dyes attached to the surface of the aramid fibers. .

  Here, when the aramid fiber is in the form of a cloth, the solvent treatment can be performed while running in the longitudinal direction. In this case, the traveling aramid fiber fabric is first immersed in a bath filled with a treatment liquid containing a polar solvent. Subsequently, the surplus treatment liquid is squeezed from the aramid fiber fabric by squeezing means such as mangle. Next, the aramid fiber fabric after squeezing is introduced into a continuous washing machine while running and is washed, neutralized or reduced and washed. When these series of processes are performed continuously, the time from immersion to washing, neutralization washing or reduction washing can be stably controlled. Thereby, the processing time of the immersion treatment can be maintained at a preferable timing, and uniform solvent treatment can be performed.

  Although the action of these solvent treatments is not clear, by treating the aramid fibers with the polar solvent having the above-mentioned concentration, the intermolecular bonds of the aramid fibers having a rigid molecular structure and high crystallinity are partially achieved. It is considered that many loose voids are generated. On the other hand, it is also conceivable that these polar solvents act on the dye molecules. Thus, it is considered that the vat dye or sulfur dye attached to the fiber surface in the dye application step is firmly dyed in the fine voids of the aramid fiber by the solvent treatment step.

  In the first embodiment, as described above, a vat dye or a sulfur dye having particularly good light fastness is used. In this way, by passing through a series of dyeing operations 1 (dye application step → solvent treatment step), dyeing aramid fibers having a practical dyeing density and good dyeing fastness, particularly light fastness. You can get things. In particular, the dyeing method according to the present invention is a unique dyeing method that does not exist in the conventional dyeing method, and does not use the technique of adsorption by reduction, which is the original dyeing mechanism of vat dyes or sulfur dyes.

Moreover, the dyeing | staining density | concentration of an aramid fiber can be improved by repeating the above-mentioned dyeing | staining operation 1 (dye provision process-> solvent processing process) in multiple times. That is, a darker aramid fiber can be obtained by performing the second dyeing operation 1 again on the aramid fiber dyed by one dyeing operation 1 by the above-described method. Furthermore, the dyeing density can be further improved by repeating the same dyeing operation 1 again. Thus, the dyeing fastness of the dyed product dyed in dark color can maintain a good state.
(2) 2nd Embodiment The dyeing | staining method which concerns on this 2nd Embodiment is the solvent provision which processes the aramid fiber by the dye provision process which provides a vat dye or a sulfur dye to an aramid fiber, and the process liquid containing a polar solvent. And a heat treatment step of heat treating the aramid fiber after the solvent treatment step. In the second embodiment, these series of steps are collectively referred to as “staining operation 3”. The dyeing operation 3 (dye application step → solvent treatment step → heat treatment step) may be performed only once, or may be repeated a plurality of times if necessary. By repeating this dyeing operation a plurality of times, darker aramid fibers can be obtained.

A. Dye provision process The dye provision process in this 2nd Embodiment performs operation similar to the dye provision process in the said 1st Embodiment.

B. Solvent Treatment Step The solvent treatment step in the second embodiment performs the same operation as the solvent treatment step in the first embodiment. However, in the second embodiment, the aramid fiber after the solvent treatment is introduced into the subsequent heat treatment step without being washed, neutralized or reduced and washed.

C. Heat treatment process In the aramid fiber after the solvent treatment process described above, the vat dye or sulfur dye is already dyed. Here, it is considered that by performing the heat treatment, the dyeing of the vat dye or the sulfur dye further proceeds on the aramid fiber and the dyed product becomes more robust. However, when sulfuric acid is used as the polar solvent, the fiber strength is greatly reduced, so that heat treatment cannot be performed.

  This heat treatment may be a dry heat treatment or a wet heat treatment, but usually a dry heat treatment is preferred. This heat treatment is preferably performed at a temperature of 50 ° C. or higher and 200 ° C. or lower. In the heat treatment step, the aramid fiber is treated in a state where a polar solvent is applied. Therefore, when the temperature is higher than 200 ° C., the physical properties of the aramid fiber may be deteriorated, which is not preferable. In addition, when processed at an extremely high temperature, the vat dye or sulfur dye may be decomposed, and the hue changes greatly.

  On the other hand, the treatment time of the heat treatment may be appropriately selected in relation to the type and form of aramid fiber, the type of vat dye or sulfur dye to be used, and is not particularly problematic, but usually 30 seconds to 30 minutes. It is done in about time. Furthermore, the heat treatment time is preferably about 30 seconds to 5 minutes. Even if the heat treatment time is about 30 seconds, the effect of the heat treatment is maintained. As described above, when the heat treatment time is about 30 seconds to 30 minutes, the dyeing density hardly changes even when the treatment time slightly varies, and the dyeing is performed at a practical dyeing density. be able to.

  Here, when the aramid fiber is in the form of a cloth, the aramid fiber cloth after the above-mentioned solvent treatment step may be introduced into a continuous heat treatment apparatus and heat-treated while running. When a series of treatments from the solvent treatment step to the heat treatment step are performed continuously, the treatment time from the solvent immersion to the heat treatment can be controlled stably, and the treatment times of the solvent treatment and the heat treatment are preferred timing. And uniform solvent treatment and heat treatment can be performed.

  Here, the action when these solvent treatment and heat treatment are combined is not clear, but by treating the aramid fiber with the polar solvent having the above-mentioned concentration and heat-treating at the above-mentioned temperature, a rigid molecule is obtained. It is conceivable that the intermolecular bonds of the aramid fibers having a structure and high crystallinity are further loosened than when the solvent treatment alone, and more fine voids are generated. On the other hand, it is also conceivable that the action of the polar solvent on the dye molecule is increased by the heat treatment. Thus, the vat dye or sulfur dye dyed on the aramid fiber in the solvent treatment step is considered to be more strongly dyed into the fine voids of the aramid fiber by the heat treatment step after the solvent treatment step.

  Next, the aramid fiber after the heat treatment step is washed to remove the remaining polar solvent. As this washing, washing with water or hot water may be performed, but reduction washing may be performed in order to remove undyed vat dye or sulfur dye attached to the surface of the aramid fiber.

  In the second embodiment, as described above, a vat dye or sulfur dye having particularly good light fastness is used. In this way, an aramid having a practical dyeing density and good dyeing fastness, in particular, light fastness, through a series of dyeing operations 3 (dye application step → solvent treatment step → heat treatment step) A dyed fiber can be obtained. In particular, the dyeing method according to the present invention is a unique dyeing method that does not exist in the conventional dyeing method, and does not use the technique of adsorption by reduction, which is the original dyeing mechanism of vat dyes or sulfur dyes.

Moreover, the dyeing | staining density | concentration of an aramid fiber can be improved by repeating the above-mentioned dyeing | staining operation 3 (dye provision process-> solvent processing process-> heat processing process) in multiple times. That is, a darker aramid fiber can be obtained by performing the second dyeing operation 3 again on the aramid fiber dyed by one dyeing operation 3 by the above-described method. Furthermore, the dyeing density can be further improved by repeating the same dyeing operation 3 again. Thus, the dyeing fastness of the dyed product dyed in dark color can maintain a good state.
(3) Third Embodiment In the dyeing method according to the third embodiment, an aramid fiber and a vat dye are used before the dyeing operation 1 or the dyeing operation 3 described in the first embodiment or the second embodiment. It has a pre-dyeing step of dyeing with dyes other than sulfur dyes. The dyeing operation 1 or the dyeing operation 3 performed after the pre-dyeing step may be performed only once, or may be repeated a plurality of times as necessary. A darker aramid fiber can be obtained by repeating this dyeing operation 1 or dyeing operation 3 a plurality of times.

D1. Pre-dyeing step In the dyeing method according to the third embodiment, first, a pre-dyeing step is performed on unstained aramid fibers. In this pre-dyeing step, a dyeing liquid containing dyes other than vat dyes and sulfur dyes is used. The dyeing method in the pre-dying step may be any method, but dyeing mainly by dip dyeing is performed. The prescription of the dyeing solution used in the pre-dying step may be the same as the usual dyeing method for the dye used. Therefore, when aramid fibers themselves are dyed, a carrier or the like may be used in combination as in the conventional dyeing method for aramid fibers. On the other hand, when the aramid fiber is a mixed fiber with other chemical fibers or natural fibers and these other fibers are dyed, a normal dyeing method for the other fibers may be performed.

  When the aramid fiber itself is dyed in this pre-dyeing step, the dye used can be any dye that has an affinity for the aramid fiber. For example, it is preferable to use a disperse dye, a cationic dye, an acid dye, or the like, as in a normal polyamide fiber. In particular, it is preferable to use a dye selected from the viewpoint of dyeability and dyeing fastness for aramid fibers. On the other hand, when the aramid fiber is a mixed fiber with other chemical fiber or natural fiber and dyes these other fibers, an appropriate dye may be used for the other fibers. For example, when the other fiber is a polyester fiber, a disperse dye is used. When the other fiber is cotton or rayon fiber, reactive dye or direct dye is used.

  When the aramid fiber itself is dyed, the aramid fiber is put into a dyeing solution containing the dye, the temperature of the dyeing solution is raised to the dyeing temperature, and this dyeing temperature is maintained for a predetermined time. Although this dyeing | staining temperature is adjusted with the kind and form of an aramid fiber, and the kind and dyeing density | concentration of the dye to be used, it should just be a temperature of 80 to 150 degreeC normally. Moreover, it is preferable that it is a temperature of 100 to 140 degreeC, and it is more preferable that it is a temperature of 120 to 135 degreeC. In the case of dyeing at a temperature exceeding 100 ° C., a high-temperature high-pressure dyeing machine is used.

  When dyeing aramid fibers themselves, if the dyeing temperature is lower than 80 ° C., a sufficient dyeing concentration cannot be obtained, while if the dyeing temperature is higher than 150 ° C., it is generally used. Compared to high-temperature and high-pressure dyeing machines, special specification equipment is required, and the energy cost is also increased.

  On the other hand, the dyeing time after the temperature rise may be appropriately selected in relation to the type of dye, the dyeing temperature, and the dyeing device. For example, at a dyeing temperature of 135 ° C. using a disperse dye, the dyeing time is 10 minutes to 90 minutes. Within the range is preferable. The dyeing bath ratio is not particularly limited, and may be in the range of 1: 5 to 1: 100, for example. The aramid fiber after dyeing is washed by a normal method. Further, reduction cleaning may be performed in the same manner as in the conventional dyeing process with disperse dyes.

  In the third embodiment, the following dyeing operation is subsequently performed on the aramid fibers subjected to the above pre-dying process.

A. Dye provision process The dye provision process in this 3rd Embodiment performs operation similar to the dye provision process in the said 1st Embodiment or the said 2nd Embodiment.

B. Solvent Treatment Step The solvent treatment step in the third embodiment performs the same operation as the solvent treatment step in the first embodiment or the second embodiment.

C. Heat Treatment Step In the third embodiment, a heat treatment step may be performed as necessary. In addition, when performing a heat treatment process in 3rd Embodiment, operation similar to the heat treatment process in the said 2nd Embodiment is performed.

  In the third embodiment, as described above, by performing a series of dyeing operations 1 or 3 after performing the pre-dyeing step, a practical dyeing density is obtained, and the dyeing fastness, in particular, A dyed aramid fiber having good light fastness can be obtained.

Furthermore, in the third embodiment, the following effects can be achieved by performing the pre-staining step. First, for the aramid fiber itself, for example, by performing a pre-dyeing step with a disperse dye, a cationic dye or an acid dye, the fluff on the surface of the aramid fiber itself is more fully dyed, and the dyeing quality and dyeing density are further increased. improves. On the other hand, when the aramid fiber is a mixed fiber with other chemical fiber or natural fiber, the hue of the aramid fiber and the other fiber is obtained by performing a pre-dyeing step with a dye capable of dyeing these other fibers. The dyeing quality and dyeing density of the dyed product are further improved.
(4) Fourth Embodiment In the dyeing method according to the fourth embodiment, after the dyeing operation 1 or the dyeing operation 3 described in the first embodiment or the second embodiment, an aramid fiber is treated with a vat dye and sulfide. It has a post-dyeing step of dyeing with a dye other than the dye. The dyeing operation 1 or the dyeing operation 3 performed before the post-dyeing step may be performed only once, or may be repeated a plurality of times as necessary. By repeating this dyeing operation a plurality of times, darker aramid fibers can be obtained.

A. Dye provision process The dye provision process in this 4th Embodiment performs operation similar to the dye provision process in the said 1st Embodiment or the said 2nd Embodiment.

B. Solvent Treatment Step The solvent treatment step in the fourth embodiment performs the same operation as the solvent treatment step in the first embodiment or the second embodiment.

C. Heat treatment step In the fourth embodiment, a heat treatment step may be performed if necessary. In addition, when performing a heat treatment process in 4th Embodiment, operation similar to the heat treatment process in the said 2nd Embodiment is performed.

D2. Post-dyeing step The post-dyeing step in the fourth embodiment performs the same operation as the pre-dyeing step described in the third embodiment. However, the aramid fiber dyed in the post-dyeing step is already dyed with the vat dye or the sulfur dye by the dyeing operation 1 or the dyeing operation 3 unlike the pre-dying step of the third embodiment.

  In the fourth embodiment, as described above, after performing a series of dyeing operation 1 or dyeing operation 3 and passing through a post-dyeing step, the dyeing dye has a practical dyeing density and has a fastness to dyeing. A dyed aramid fiber having good light fastness can be obtained.

  Furthermore, in the fourth embodiment, the following effects can be achieved by performing the post-dyeing step. First, for the aramid fiber itself, for example, by performing a post-dyeing step with a disperse dye, a cationic dye or an acid dye, the fluff on the surface of the aramid fiber itself is more fully dyed, and the dyeing quality and dyeing density are further increased. improves. On the other hand, when the aramid fiber is a mixed fiber with other chemical fiber or natural fiber, the hue between the aramid fiber and the other fiber is performed by performing a post-dyeing step with a dye capable of dyeing these other fibers. The dyeing quality and dyeing density of the dyed product are further improved.

  Hereinafter, based on the first embodiment to the fourth embodiment, for each of the para-aramid fiber, the para-copolymerized aramid fiber, and the meta-aramid fiber, the following examples and comparative examples are as follows. Was stained.

Example 1
In Example 1, N-methyl-2-pyrrolidone was used as a polar solvent, and a fabric made of aramid fibers (hereinafter referred to as “aramid fabric”) was dyed based on the second embodiment described above. In Example 1, a twill woven fabric having a basis weight of 244 g / m ² (hereinafter referred to as “para-based aramid fabric”) using paraffin aramid fibers of 100% by weight as a 20th yarn for warp and weft, and a para-copolymerization A twill woven fabric with a basis weight of 244 g / m ² (hereinafter referred to as “para-copolymerized aramid fabric”) using 20-count double yarn of 100% by weight of aramid fiber for warp and weft, and 40-count double of 100% by weight of meta-aramid fiber. A twill fabric (hereinafter referred to as “meta-aramid fabric”) having a basis weight of 200 g / m ² and using warp and weft yarns was used. These aramid fabrics were used after being desizing and scouring by a usual method.

A. Dye application process Dye application was performed by a continuous method, and a vat dye was applied to each aramid fabric by pad-niping a dye solution containing the vat dye using a test mangle device. The pickup rates at this time were 61% by weight of para-aramid fabric, 58% by weight of para-copolymerized aramid fabric, and 67% by weight of meta-aramid fabric, respectively.

  In the staining solution, 50 g / L of vat dye was dispersed in a non-reduced state, and Tamanori SA-25 (Arakawa Chemical Industries, Ltd .; hereinafter referred to as “Tamanori”) was used in combination as a migration inhibitor. The dye used was Mikethren Blue BC super-fine (Dyster Japan Co., Ltd. Vat Dye, CI Vat Blue 6).

  The drying was performed using a test baking box device, and each aramid fabric after the dyeing solution was applied was dried at 105 ° C. for 5 minutes, and the vat dye was adhered to the fiber surface of each aramid fabric. Each aramid fabric after drying was put in the subsequent solvent treatment step (N-methyl-2-pyrrolidone treatment step) without washing or reducing washing.

B. Solvent treatment step (N-methyl-2-pyrrolidone treatment step)
As a polar solvent, N-methyl-2-pyrrolidone was used and treated as an aqueous solution having a concentration of 60% by weight. A test mangle device was used for applying the treatment liquid, and each aramid fabric after the dye application step was subjected to solvent treatment by a continuous method. The treatment temperature at this time was 20 ° C. In the treatment, the aramid fabric was immersed in the treatment solution for 1 second and immediately squeezed with mangle. The pickup rates at this time were 59% by weight of para-aramid fabric, 59% by weight of para-copolymerized aramid fabric, and 62% by weight of meta-aramid fabric, respectively.

C. Heat treatment step A test baking box apparatus was used for the heat treatment, and each aramid fabric after the solvent treatment was subjected to a dry heat treatment at 105 ° C. for 5 minutes to attach the vat dye to each aramid fabric. Each aramid fabric after the heat treatment was dried after removing N-methyl-2-pyrrolidone remaining by washing with water and hot water.

  Next, reduction washing was performed on each dyed aramid fabric after the heat treatment step. This reduction washing was performed in order to remove undyed vat dye remaining on the fiber surface and improve the dyeing fastness. The conditions for the reduction washing are the same as the dyeing of the polyester fiber with the disperse dye, under the condition of 1 g / L of sodium dithionite and 1 g / L of sodium hydroxide as a reducing agent at 80 ° C. for 1 minute. Then, each aramid fabric of Example 1 dyed navy blue having a practical dyeing density was obtained.

≪Comparative example 1≫
In contrast to Example 1 described above, Comparative Example 1 was used in which each aramid fabric was subjected only to the dye application step and not subjected to the solvent treatment step and the heat treatment step. Specifically, dye application was performed under the same conditions as in Example 1 above, and reduction cleaning was performed on each aramid fabric after application of vat dye. This reduction cleaning was performed under the same conditions as in Example 1, and then washed with hot water and water and dried to obtain each aramid fabric of Comparative Example 1.

  The dyed aramid fabrics of Example 1 and Comparative Example 1 dyed as described above were evaluated as follows.

Staining density (total K / S value):
The surface dyeing concentration of each dyed aramid fabric was expressed as a total K / S value. The larger the total K / S value, the deeper the aramid fabric is dyed. The total K / S is a value obtained by summing 16 K / S values of 16 wavelengths measured at 20 nm intervals in a measurement range of wavelengths from 400 nm to 700 nm. The K / S value is obtained from the reflectance R at each wavelength by the following Kubelka-Munk equation. Here, K represents an extinction coefficient, and S represents a light scattering coefficient.

K / S = (1-R) ² / 2R
The value of reflectance R at each wavelength was measured using a spectrophotometer UV-3100 (manufactured by Shimadzu Corporation) equipped with an integrating sphere. Table 1 shows the total K / S value calculated by the above formula for each aramid fabric.

Lightness (L ^* value):
The degree of dark color of each dyed aramid fabric was evaluated by the lightness (L ^* value) in the L ^* a ^* b ^* color system described above. The L ^* value is expressed in the range of 100 (white) to 0 (black), and the darker the color, the lower the L ^* value. The L ^* value was measured using a color difference meter CR-200 (manufactured by Minolta Camera Co., Ltd.). Table 1 shows L ^* values of the obtained aramid fabrics.

Color fastness:
In addition to the dyeing density (total K / S value) and lightness (L ^* value), dyeing fastness was confirmed as a basic evaluation item of the dyed product. In particular, light fastness (JIS L0842), which is a problem in dyeing fastness of aramid fibers, was evaluated. The light fastness of an aramid fiber was evaluated as follows, since it was difficult to evaluate the yellowish browning of the fiber itself in addition to the dye discoloration caused by light irradiation. Each aramid fabric was irradiated with a blue scale grade 4 and the change was graded with a gray scale for fading. In addition, in addition to the five grades from the first grade (bad) to the fifth grade (good), the grade evaluation was also performed in the middle of each grade. For example, the evaluation between grade 3 and grade 4 was 3-4 grade. The evaluation results are shown in Table 1.

As can be seen from Table 1, in Example 1, each of the aramid fabrics has a practical dyeing density (total K / S value) and lightness (L ^* value). Have good light fastness. Furthermore, although not shown in Table 1, in the dyed aramid fabrics of Example 1, the properties of practical high-performance fibers are maintained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was. On the other hand, in Comparative Example 1, each of the aramid fabrics is inferior in dyeing density, lightness, and light fastness compared to Example 1, and in particular, the dyeing concentration, lightness, and light fastness of the meta-aramid fabric are insufficient. It was something.

<< Example 2 >>
In Example 2, N-methyl-2-pyrrolidone was used as a polar solvent, and an aramid fabric was dyed based on the second embodiment described above. In Example 2, a twill woven fabric having a basis weight of 160 g / m ² (hereinafter referred to as “mixed spinning”) using 40-count double yarns in which 95% by weight of a meta-aramid fiber and 5% by weight of a para-copolymerized aramid fiber are used for warp and weft. Aramid fabric ") was used. This blended aramid fabric was used after being desizing and scouring by a usual method.

A. Dye provision process With respect to the above Example 1, the same operation as in Example 1 was performed except that the dye used was changed to the following sulfur dye. The pickup rate at this time was 80% by weight. In the dyeing solution, 50 g / L of a sulfur dye was dispersed in a non-reducing state, and tamanori was used in combination as a migration inhibitor. The sulfur dye used was Asathio Blue RC200 (sulfur dyes manufactured by Asahi Chemical Industry Co., Ltd., CI Sulfur Blue 7).

  For drying, the blended aramid fabric after the dyeing solution was applied was dried at 105 ° C. for 5 minutes in the same manner as in Example 1, and the sulfur dye was adhered to the fiber surface of the blended aramid fabric. The dried mixed aramid fabric was put into the subsequent solvent treatment step (N-methyl-2-pyrrolidone treatment step) without washing or reducing washing.

B. Solvent treatment step (N-methyl-2-pyrrolidone treatment step)
In Example 2, the same N-methyl-2-pyrrolidone as in Example 1 was used as the polar solvent, but the concentration was 100% by weight. A test mangle device was used for applying the treatment liquid, and the mixed aramid fabric after the dye application step was subjected to solvent treatment by a continuous method. The processing temperature at this time was 50 degreeC. In the treatment, the blended aramid fabric was dipped in the treatment solution for 1 second and immediately squeezed with mangle. The pickup rate at this time was 88% by weight.

C. Heat treatment step Heat treatment is performed in the same manner as in Example 1 above, and using a test baking box apparatus, the mixed aramid fabric after the solvent treatment is subjected to a dry heat treatment at 105 ° C. for 5 minutes to attach the sulfur dye to the mixed aramid fabric. did. The blended aramid fabric after heat treatment was prepared by removing the remaining N-methyl-2-pyrrolidone by washing with hot water and water and drying, and then blending the blended aramid fabric of Example 2 dyed in navy blue having a practical dyeing density. Obtained.

≪Comparative example 2≫
For Example 2 above, the blended aramid fabric was subjected only to the dye application step, and the solvent treatment step and the heat treatment step were not used as Comparative Example 2. Specifically, the dye application step was performed under the same conditions as in Example 2, and the blended aramid fabric after the sulfur dye was applied was washed with hot water, washed with water, dried, and dyed navy blue. A blend of aramid fabrics was obtained.

The dyed blended aramid fabrics of Example 2 and Comparative Example 2 dyed as described above were evaluated in the same manner as in Example 1 above. Table 2 shows the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness evaluation results.

As can be seen from Table 2, in Example 2, a blended aramid fabric having a practical dyeing density (total K / S value) and lightness (L ^* value) could be obtained. Moreover, the blended aramid fabric of Example 2 has good light fastness. Further, although not shown in Table 2, in the dyed blended aramid fabric of Example 2, the properties of a practical high-performance fiber are maintained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was. On the other hand, in Comparative Example 2, the dyeing density and lightness are considerably inferior to those of Example 2, and the light fastness is low, so that practical dyeings are not obtained.

Example 3
In Example 3, N-methyl-2-pyrrolidone was used as a polar solvent, and an aramid fabric was dyed based on the second embodiment described above. In Example 3, the same dyeing operation as in Example 1 was repeated a plurality of times for each dyed aramid fabric obtained in Example 1 above. Specifically, the above-mentioned Example 1 was dyed once, and the dyeing operation combining the dye application step, the solvent treatment step and the heat treatment step was repeated for a total of 3 times, a total of 5 times and a total of 7 times of the dyeing operation. went. However, reduction cleaning was performed only after the final staining operation.

Each dyed aramid fabric of Example 3 dyed as described above was evaluated in the same manner as in Example 1. Table 3 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 3, in each aramid fabric, in Example 3, the dyeing concentration (total K / S value) is greatly improved as the number of dyeing operations increases, compared to Example 1 in which the dyeing operation is performed once. In addition, the lightness (L ^* value) was reduced to about 30 or less, and each aramid fabric of extremely dark color could be obtained. As shown in Table 3, each of these extremely dark aramid fabrics has good light fastness. Furthermore, although not shown in Table 3, in the dyed aramid fabrics of Example 3, the properties of practical high-performance fibers are maintained without causing dyeing unevenness, dimensional changes, or significant deterioration in physical properties. Was.

Example 4
In Example 4, N-methyl-2-pyrrolidone was used as a polar solvent, and an aramid fabric was dyed based on the second embodiment described above. In Example 4, the same aramid fabric as in Example 1 above was subjected to a dyeing operation with a vat dye a plurality of times in the same manner as in Example 3. However, the vat dye used was Indanthren Brilliant Pink R (Dyster Japan Co., Ltd. vat dye, CI Vat Red 1). Specifically, the same dyeing operation was performed once as a result of the dyeing operation combining the dye application step, the solvent treatment step, and the heat treatment step as in Example 1 above, and the same dyeing operation was repeated twice in total. A total of three staining operations were performed. However, reduction cleaning was performed only after the final staining operation.

Each dyed aramid fabric of Example 4 dyed as described above was evaluated in the same manner as in Example 1. Table 4 shows the evaluation results of the total K / S value for evaluating the staining density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 4, in each aramid fabric, as the number of dyeing operations is increased, the dyeing density (total K / S value) is greatly improved as compared to one dyeing operation, and dark aramid fabrics can be obtained. did it. However, the lightness (L ^* value) is greater than 38 due to the fact that the dye used is “Pink R”. This is because Example 4 is a prescription for dyeing vivid red and is not a prescription intended for dark navy blue or black. On the other hand, as shown in Table 4, each aramid fabric has good light fastness. Furthermore, although not shown in Table 4, the dyed aramid fabrics of Example 4 maintain the properties of practical high-performance fibers without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was.

Example 5
In Example 5, N-methyl-2-pyrrolidone was used as a polar solvent, and an aramid fabric was dyed based on the above-described fourth embodiment (dyeing with vat dyes → post-dyeing with disperse dyes). In Example 5, a post-dyeing step with a disperse dye was then performed on each aramid fabric dyed with the vat dye obtained in Example 1 above.

D2. Post-dyeing step with disperse dye Dyeing is carried out by a dip dyeing method with disperse dye, and each aramid after dyeing vat dye obtained in Example 1 above using a high-temperature high-pressure dyeing tester mini color (manufactured by Tecsum Giken Co., Ltd.) The fabric was dyed without reducing washing. As the staining solution, Dianix Blue FBL-E (Disperse dye manufactured by Dystar Japan Co., Ltd., CI Disperse Blue 56) 5% owf was used, and a pH 5 acetic acid / sodium acetate buffer was used in combination.

  Dyeing was performed at a bath ratio of 1: 100, and high-temperature high-pressure dyeing was performed at 135 ° C. for 60 minutes. Each aramid fabric after dyeing was subjected to reduction cleaning in the same manner as dyeing with disperse dyes for ordinary polyester fibers. The reduction cleaning is performed under the condition of 1 g / L of sodium dithionite and 1 g / L of sodium hydroxide as a reducing agent at 80 ° C. for 1 minute, followed by hot water washing, water washing and drying. Each aramid fabric of Example 5 dyed in navy blue was obtained.

«Comparative Example 3»
For Example 5 above, each aramid fabric was only dyed with a disperse dye as Comparative Example 3. Specifically, only the disperse dye dyeing step similar to the above Example 5 was performed without performing any dyeing operation of the dye applying step, the solvent treatment step and the heat treatment step according to the present invention. Similarly, each of the aramid fabrics of Comparative Example 3 dyed in navy blue was obtained by performing reduction washing, hot water washing, water washing and drying.

<< Comparative Example 4 >>
Moreover, what carried out only the solvent processing process, the heat processing process, and the disperse dye dyeing process to each aramid fabric with respect to the said Example 5 was made into the comparative example 4. Specifically, after performing only the solvent treatment step and the heat treatment step without performing the dye application step for applying the vat dye, the same disperse dye dyeing step as in Example 5 is performed, and then the same as in Example 5. Each of the aramid fabrics of Comparative Example 4 was subjected to reduction washing, hot water washing, water washing and drying to obtain a navy blue dyeing.

The dyed aramid fabrics of Example 5, Comparative Example 3 and Comparative Example 4 dyed as described above were evaluated in the same manner as in Example 1 above. Table 5 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 5, the dyeing density (total K / S value) is greatly improved in Example 5 dyed with disperse dyes as compared with Example 1 dyed with vat dyes alone, and the lightness. (L ^* value) was reduced to 30 or less, and each aramid fabric of extremely dark color could be obtained. As shown in Table 5, each of the extremely dark aramid fabrics has a light fastness that is even better than that of Example 1. Further, in each aramid fabric of Example 5, the fluff on the fabric surface was dyed in a very dark color with both the vat dye and the disperse dye, and the surface quality of the fabric was further improved. Further, although not shown in Table 5, in each dyed aramid fabric of Example 5, the properties of practical high-performance fibers are maintained without causing dyeing unevenness, dimensional change, or significant deterioration in physical properties. Was.

  On the other hand, in Comparative Example 3, all the aramid fabrics are inferior in dyeing density and brightness as compared with Example 5. Further, each of these aramid fabrics was dyed only with a disperse dye, and the light fastness was insufficient as compared with Example 5 and Example 1. In Comparative Example 4, the dyeing density and lightness with the disperse dye are improved as compared with Comparative Example 3 due to the effect of the solvent treatment. However, each aramid fabric of Comparative Example 4 is inferior in dyeing density and lightness as compared with Example 5. In addition, each aramid fabric of Comparative Example 4 was dyed only with a disperse dye, and the light fastness was insufficient as compared with Example 5.

Example 6
In Example 6, sulfuric acid was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In this Example 6, the same blended aramid fabric as in Example 2 was used. This blended aramid fabric was used after being desizing and scouring by a usual method.

A. Dye application step In this Example 6, the same vat dye “Mikethren Blue BC super-fine” as in Example 1 above, or the same vat dye “Indanthren Brilliant Pink R” as in Example 4 above was used. The operation in the dye application step was performed in the same manner as in Example 1. The pickup rate at this time was 80% by weight.

  For drying, the blended aramid fabric after the dyeing solution was applied was dried at 105 ° C. for 5 minutes in the same manner as in Example 1 above, and the vat dye was adhered to the fiber surface of the blended aramid fabric. The dried blended aramid fabric was put into the subsequent solvent treatment step (sulfuric acid treatment step) without washing or reducing washing.

B. Solvent treatment process (sulfuric acid treatment process)
The sulfuric acid treatment was carried out by a continuous method, and the mixed aramid fabric after the dye application step was subjected to sulfuric acid treatment using a test mangle device. The concentration of the sulfuric acid aqueous solution used was 77% by weight, and the treatment temperature was 20 ° C. After dipping, the solution was squeezed with mangles to obtain a pick-up rate of 156% by weight, quickly washed with water, neutralized with an aqueous sodium carbonate solution and washed with water. The immersion time with the sulfuric acid aqueous solution was 30 seconds. The blended aramid fabric after the solvent treatment step was thoroughly washed with water and then dried.

  Next, reduction washing was performed on the dyed blended aramid fabric after the sulfuric acid treatment. This reduction washing was performed under the same conditions as in Example 1, and then washed with hot water and water and dried to obtain a blended aramid fabric of Example 6 having a practical dyeing concentration.

<< Comparative Example 5 >>
For Example 6, the mixed aramid fabric was subjected to only the dye application step and was not subjected to sulfuric acid treatment, and Comparative Example 5 was obtained. Specifically, the dye application step was performed under the same conditions as in Example 1 above, and reduction washing was performed on the blended aramid fabric after application of the vat dye. This reduction washing was performed under the same conditions as in Example 1, and then washed with hot water and water and dried to obtain a blended aramid fabric of Comparative Example 5.

The dyed mixed aramid fabrics of Example 6 and Comparative Example 5 dyed as described above were evaluated in the same manner as in Example 1 above. Table 6 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 6, in Example 6, a blended aramid fabric having a practical dyeing density (total K / S value) and lightness (L ^* value) in the vat dye “Blue BC” can be obtained. It was. On the other hand, the vat dye “Pink R” of Example 6 is a prescription for dyeing bright red as in Example 4 above, and the lightness (L ^* value) does not show a very small value. However, a blended aramid fabric having a practical dyeing density (total K / S value) is also obtained with the vat dye “Pink R”. Moreover, all the blended aramid fabrics of Example 6 have good light fastness. Furthermore, although not shown in Table 6, in the dyed blended aramid fabric of Example 6, the properties of a practical high-performance fiber are maintained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was. On the other hand, in Comparative Example 5, both the dyeing density and the light fastness are inferior to those in Example 6, and a practical dyed product cannot be obtained.

Example 7
In Example 7, sulfuric acid was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In this Example 7, among the dyed blended aramid fabrics obtained in Example 6 above, the blended aramid fabrics dyed with the vat dye “Mikethren Blue BC super-fine” were compared with the above Example 6 and The same staining operation was repeated several times. Specifically, the above Example 6 was used as one dyeing operation, and the dyeing operation combined with the dye application step and the solvent treatment step (sulfuric acid treatment step) was repeated three times in total, five times in total, and seven times in total. The operation was performed. However, reduction cleaning was performed only after the final staining operation.

The dyed blended aramid fabric of Example 7 dyed as described above was evaluated in the same manner as in Example 1 above. Table 7 shows the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness evaluation results.

As can be seen from Table 7, in Example 7, the staining density (total K / S value) is greatly improved and the lightness (L ^* ) is increased as the number of staining operations is increased in comparison with Example 6 in which one staining operation is performed ^. (Value) was reduced to 25 or less, and an extremely dark colored mixed aramid fabric could be obtained.
As shown in Table 7, these extremely dark blended aramid fabrics have good light fastness. Furthermore, although not shown in Table 7, in the dyed blended aramid fabric of Example 7, the properties of practical high-performance fibers are maintained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was.

Example 8
In Example 8, sulfuric acid was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In Example 8, the same blended aramid fabric as in Example 6 was dyed with a sulfur dye. This blended aramid fabric was used after desizing and scouring in the same manner as in Example 6 above.

A. Dye provision process In this Example 8, operation similar to the said Example 6 was performed with respect to the said Example 6 except having changed the dye to be used into the following sulfurized dye. The pickup rate at this time was 80% by weight. In the dyeing solution, 50 g / L of a sulfur dye was dispersed in an unreduced state, and tamanori was used in combination as a migration inhibitor. The sulfur dyes used were Asathiosol Yellow S-RR (sulfur dyes manufactured by Asahi Chemical Industry Co., Ltd., CI No. unknown), Asathiosol Bordeaux S-3B (sulfur dyes manufactured by Asahi Chemical Industry Co., Ltd., CI Sulphur). Red 6), Asathio Blue RC200 (sulfurized dye manufactured by Asahi Chemical Industry Co., Ltd., CI Sulfur Blue 7), Asathiosol Indigo Green S-BG (sulfurized dye manufactured by Asahi Chemical Industry Co., Ltd., CI Sulfur Blue 15) Met.

  For drying, the blended aramid fabric after the dyeing solution was applied was dried at 105 ° C. for 5 minutes in the same manner as in Example 6 above, and the sulfur dye was adhered to the fiber surface of the blended aramid fabric. The dried blended aramid fabric was put into the subsequent solvent treatment step (sulfuric acid treatment step) without washing or reducing washing.

B. Solvent treatment process (sulfuric acid treatment process)
In Example 8, sulfuric acid treatment was performed on the blended aramid fabric after the dye application step in the same manner as in Example 6. The concentration of the sulfuric acid aqueous solution used was 77% by weight, the treatment temperature was 20 ° C., and the immersion time was 30 seconds. The pick-up rate at this time was 156% by weight, and was washed with water, neutralized and washed in the same manner as in Example 6 and dried to obtain a blended aramid fabric of Example 8 having a practical dyeing concentration.

<< Comparative Example 6 >>
In contrast to Example 8 above, Comparative Example 6 was made by performing only the dye application step on the blended aramid fabric and not performing the sulfuric acid treatment. Specifically, the dye application step was performed under the same conditions as in Example 8 above, and the blended aramid fabric after the sulfurized dye was applied was washed with water and dried to obtain a blended aramid fabric of Comparative Example 6.

The dyed blended aramid fabrics of Example 8 and Comparative Example 6 dyed as described above were evaluated in the same manner as in Example 1 above. However, the brightness (L ^* value) is not measured. Table 8 shows the evaluation results of the total K / S value for evaluating the dyeing density and the light fastness.

  As can be seen from Table 8, in Example 8, a blended aramid fabric having a practical dyeing density (total K / S value) could be obtained. Moreover, all the blended aramid fabrics of Example 8 have good light fastness. Further, although not shown in Table 8, the dyed blended aramid fabric of Example 8 maintains the properties of practical high-performance fibers without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was. On the other hand, in Comparative Example 6, both the dyeing density and the light fastness are inferior compared to Example 8, and a practical dyed product cannot be obtained.

Example 9
In Example 9, sulfuric acid was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In Example 9, as an aramid fiber mainly composed of para aramid fibers, a twill weave having a basis weight of 144 g / m ² (hereinafter referred to as “para System single yarn aramid fabric). This para-single yarn aramid fabric was used after being desizing and scouring by a usual method.

  In Example 9, the operating conditions and the dyes used in the dye application step and solvent treatment step (sulfuric acid treatment step) were the same as in Example 6 above. At this time, the pickup rate in the dye application step was 61% by weight, and the pickup rate in the solvent treatment step was 126% by weight. After the dyeing operation with the vat dye as described above, reduction washing was performed in the same manner as in Example 1 to obtain a para single yarn aramid fabric of Example 9 having a practical dyeing concentration.

<< Comparative Example 7 >>
In contrast to Example 9, the para single yarn aramid fabric was subjected to only the dye application step and was not subjected to sulfuric acid treatment, and Comparative Example 7 was obtained. Specifically, the dye application step was performed under the same conditions as in Example 9 above, and reduction washing was performed under the same conditions as in Example 1 on the para single yarn aramid fabric after application of vat dye. Thereafter, washing with hot water, washing with water and drying were performed to obtain a para single yarn aramid fabric of Comparative Example 7.

The dyed para single yarn aramid fabrics of Example 9 and Comparative Example 7 dyed as described above were evaluated in the same manner as in Example 1 above. However, the brightness (L ^* value) is not measured. Table 9 shows the evaluation results of the total K / S value for evaluating the dyeing density and the light fastness.

  As can be seen from Table 9, in Example 9, a para single yarn aramid fabric having a practical dyeing density (total K / S value) could be obtained. Moreover, all the para type | system | group single yarn aramid fabrics of Example 9 have favorable light fastness. Furthermore, although not shown in Table 9, in the dyed para single yarn aramid fabric of Example 9, practical high-performance fibers without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. The nature was maintained. On the other hand, in Comparative Example 7, both the dyeing density and the light fastness are inferior to those in Example 9, and a practical dyed product is not obtained.

Example 10
In Example 10, sulfuric acid was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In the present Example 10, among the dyed para single yarn aramid fabrics obtained in Example 9, the para single yarn aramid fabrics dyed with the vat dye “Mikethren Blue BC super-fine” are used. The same dyeing operation as in Example 9 was repeated several times. Specifically, the above Example 9 was used as a single dyeing operation, and the dyeing operation combined with the dye application step and the solvent treatment step (sulfuric acid treatment step) was repeated three times in total, five times in total, and seven times in total. The operation was performed. However, reduction cleaning was performed only after the final staining operation.

The dyed para single yarn aramid fabric of Example 10 dyed as described above was evaluated in the same manner as in Example 1 above. However, the brightness (L ^* value) is not measured. Table 10 shows the total K / S value for evaluating the dyeing concentration and the evaluation results of light fastness.

  As can be seen from Table 10, in Example 10, as the number of dyeing operations increases, the dyeing density (total K / S value) is greatly improved as compared to Example 9 in which one dyeing operation is performed. A woven fabric could be obtained. These extremely dark para single yarn aramid fabrics, as shown in Table 10, have good light fastness. Further, although not shown in Table 10, in the dyed para single yarn aramid fabric of Example 10, practical high-performance fibers without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. The nature was maintained.

Example 11
In Example 11, sulfuric acid was used as a polar solvent, and an aramid fabric was dyed based on the above-described fourth embodiment. In Example 11, the same blended aramid fabric as in Example 6 was used. This blended aramid fabric was used after being desizing and scouring by a usual method.

A. Dye provision process In this Example 11, as a vat dye, except using Mikethren Grey M super-fine (Dystar Japan Co., Ltd. vat dye, CI Vat Black 8) 60g / L, the above-mentioned The same operation as in Example 1 was performed. The pickup rate at this time was 80% by weight.

  For drying, the blended aramid fabric after the dyeing solution was applied was dried at 105 ° C. for 5 minutes in the same manner as in Example 1 above, and the vat dye was adhered to the fiber surface of the blended aramid fabric. The dried blended aramid fabric was put into the subsequent solvent treatment step (sulfuric acid treatment step) without washing or reducing washing.

B. Solvent treatment process (sulfuric acid treatment process)
The sulfuric acid treatment was carried out by a continuous method, and the mixed aramid fabric after the dye application step was subjected to sulfuric acid treatment using a test mangle device. The concentration of the sulfuric acid aqueous solution used was 80% by weight, and the treatment temperature was 20 ° C. After soaking, the solution was squeezed with mangles to obtain a pickup rate of 80% by weight, washed quickly with water, neutralized with an aqueous sodium carbonate solution, and washed with water. The immersion time with the sulfuric acid aqueous solution was 20 seconds. In Example 11, the mixed aramid fabric after the solvent treatment step (sulfuric acid treatment step) was put into the subsequent post-dyeing step with a disperse dye without drying.

D2. Post-dyeing process with disperse dye Dyeing is carried out by the dip dyeing method with disperse dye, and the high-temperature high-pressure dyeing tester mini color (manufactured by Tecsum Giken Co., Ltd.) is used to dry the blended aramid fabric after sulfuric acid treatment as described above. Stained. Kaylon Polyester Navy Blue NB-E (Nippon Kayaku Co., Ltd. disperse dye, CI No. unknown) 10% owf was used as the staining solution, and a pH 5 acetic acid / sodium acetate buffer was used in combination.

  Dyeing was performed at a bath ratio of 1: 100, and high-temperature high-pressure dyeing was performed at 130 ° C. for 60 minutes. The blended aramid fabric after dyeing was subjected to reduction cleaning in the same manner as dyeing with disperse dyes for ordinary polyester fibers. The reduction washing was performed under the same conditions as in the post-dyeing step of Example 5 above, followed by washing with hot water and water and drying to obtain a blended aramid fabric of Example 11 dyed in extremely dark black. .

«Comparative Example 8»
Comparative Example 8 was obtained by performing only the dyeing process with the disperse dye on the unstained blended aramid fabric with respect to Example 11 described above. In Comparative Example 8, the conditions in the dyeing step with the disperse dye were the same as in Example 11 above.

<< Comparative Example 9 >>
Comparative Example 9 was obtained by performing only the solvent treatment step (sulfuric acid treatment step) and the dyeing step with the disperse dye with respect to Example 11 described above. That is, in Comparative Example 9, a blended aramid fabric subjected to sulfuric acid treatment was dyed only with a disperse dye. In Comparative Example 9, the conditions for sulfuric acid treatment and dyeing with a disperse dye were the same as in Example 11 above.

The dyed blended aramid fabrics of Example 11, Comparative Example 8, and Comparative Example 9 dyed as described above were evaluated in the same manner as in Example 1 above. However, the brightness (L ^* value) is not measured. Table 11 shows the evaluation results of the total K / S value for evaluating the dyeing density and the light fastness.

  As can be seen from Table 11, in Example 11, the dyeing density (total K / S value) was greatly improved, and an extremely dark mixed spun aramid fabric could be obtained. Moreover, the blended aramid fabric of Example 11 has good light fastness. Further, in the blended aramid fabric of Example 11, the fluff on the fabric surface was dyed in an extremely dark color with both the vat dye and the disperse dye, and the surface quality of the fabric was further improved. Furthermore, although not shown in Table 11, in the dyed blended aramid fabric of Example 11, the properties of a practical high-performance fiber are maintained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was. On the other hand, in Comparative Example 8, the dyeing density is inferior to that in Example 11, and the light fastness is remarkably inferior, so that a practical dyed product cannot be obtained. In Comparative Example 9, a sufficient dyeing density is obtained, but since the dyeing is carried out only with a disperse dye, the light fastness is remarkably inferior, and a practical dyed product cannot be obtained.

Example 12
In Example 12, benzyl alcohol was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In Example 12, the same para-aramid fabric as in Example 1 was used. This para-aramid fabric was used after desizing and scouring by a usual method.

A. Dye provision process In the present Example 12, the following vat dye was provided by the same operation as Example 1 described above. The pickup rate at this time was 58% by weight. In the staining solution, 50 g / L of the same vat dye “Mikethren Grey M super-fine” as in Example 11 is dispersed in a non-reducing state, and GERMADYE AM-X (manufactured by RAON CHEMICAL) is used as a migration inhibitor. 10 g / L was used in combination.

  Drying was performed by drying the para-aramid fabric after the dyeing solution was applied in the same process as in Example 1 above at 110 ° C. for 2 minutes to adhere the vat dye to the fiber surface of the para-aramid fabric. The para-aramid fabric after drying was put into the subsequent solvent treatment step (benzyl alcohol treatment step) without washing or reducing washing.

B. Solvent treatment process (benzyl alcohol treatment process)
In Example 12, benzyl alcohol (99.5% product) was used as a polar solvent without dilution. For the application of the treatment liquid, a test mangle device was used, and the para-aramid fabric after the dye application step was subjected to solvent treatment by a continuous method. The treatment temperature at this time was 20 ° C. In the treatment, the para-aramid fabric was dipped in the treatment liquid for 1 second and immediately squeezed with mangle. The pickup rate at this time was 61% by weight. In Example 12, the heat treatment after the solvent treatment was not performed, and the para-aramid fabric after the solvent treatment step was washed with hot water and water to remove residual benzyl alcohol, and then subjected to reduction washing. This reduction cleaning was performed in the same manner as in Example 1 above. Thereafter, washing with hot water, washing with water and drying were performed to obtain a para-aramid fabric of Example 12 dyed in black having a practical dyeing concentration.

The dyed para-aramid fabric of Example 12 dyed as described above was evaluated in the same manner as in Example 1 above. Table 12 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 12, in Example 12, the para-aramid fabric has a practical dyeing density (total K / S value) and lightness (L ^* value), and good light fastness. have. Further, although not shown in Table 12, in the dyed para-aramid fabric of Example 12, the properties of practical high-performance fibers can be obtained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was maintained.

Example 13
In Example 13, benzyl alcohol was used as a polar solvent, and an aramid fabric was dyed based on the first embodiment described above. In Example 13, the same dyeing operation as in Example 12 was repeated a plurality of times on the dyed para-aramid fabric obtained in Example 12 above. Specifically, the above Example 12 was used as one dyeing operation, and the dyeing operation in which the dye application step and the solvent treatment step were further combined was repeated for a total of two times, a total of three times, and a total of four times of dyeing operations. However, reduction cleaning was performed only after the final staining operation.

The dyed para-aramid fabric of Example 13 dyed as described above was evaluated in the same manner as in Example 1 above. Table 13 shows the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness evaluation results.

As can be seen from Table 13, in Para-aramid fabric, in Example 13, as the number of dyeing operations increased, the dyeing density (total K / S value) greatly improved compared to Example 12 in which the dyeing operation was performed once. Further, the lightness (L ^* value) was reduced to 30 or less, and an extremely dark para-aramid fabric could be obtained. As shown in Table 13, this extremely dark para-aramid fabric has good light fastness. Further, although not shown in Table 13, in the dyed para-aramid fabric of Example 13, the properties of practical high-performance fibers can be obtained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was maintained.

<< Example 14 >>
In Example 14, four types of polar solvents, triethylene glycol, formic acid, DL-lactic acid and oxalic acid were used as polar solvents, respectively, and an aramid fabric was dyed based on the second embodiment described above. In Example 14, the same para-aramid fabric as in Example 1 was used. This para-aramid fabric was used after desizing and scouring by a usual method.

A. Dye provision process In this Example 14, the operation similar to the said Example 12 was performed using the vat dye "Mikethren Gray M super-fine" similarly to the said Example 12. FIG. The pickup rate at this time was 58% by weight. For drying, the same operation as in Example 12 was performed. The para-aramid fabric after drying was directly put into each subsequent solvent treatment step without washing or reducing washing.

B. Solvent treatment step In Example 14, triethylene glycol (95% product), formic acid (98% product) and DL-lactic acid (85% product) were all used without dilution. On the other hand, oxalic acid (dihydrate) was dissolved in water and used as a 10 wt% aqueous solution. For the application of the treatment liquid, a test mangle device was used, and the para-aramid fabric after the dye application step was subjected to solvent treatment by a continuous method. The treatment temperature at this time was 20 ° C. for all. In the treatment, the para-aramid fabric was dipped in the treatment liquid for 1 second and immediately squeezed with mangle. The pickup rates of the polar solvents at this time were 75% by weight of triethylene glycol, 71% by weight of formic acid, 81% by weight of DL-lactic acid, and 75% by weight of an oxalic acid aqueous solution, respectively.

C. Heat treatment step A test baking box apparatus was used for the heat treatment, and the vat dye was attached to the para-aramid fabric by subjecting the para-aramid fabric after each solvent treatment to a dry heat treatment at 110 ° C. for 2 minutes. The para-aramid fabric after the heat treatment was dried after removing polar solvents remaining by hot water washing and water washing.

  Next, reduction washing was performed on the dyed para-aramid fabric after the heat treatment step. This reduction cleaning was performed in the same manner as in Example 1 above. Thereafter, washing with hot water, washing with water and drying were performed to obtain a para-aramid fabric of Example 14 dyed in black having a practical dyeing concentration.

The dyed para-aramid fabric of Example 14 dyed as described above was evaluated in the same manner as in Example 1. Table 14 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 14, in Example 14, the para-aramid fabric has a practical dyeing density (total K / S value) and lightness (L ^* value) in any of the four polar solvents. In addition, it has good light fastness. Furthermore, although not shown in Table 14, in the dyed para-aramid fabric of Example 14, the properties of practical high-performance fibers can be obtained without causing dyeing unevenness, dimensional change, or significant deterioration in physical properties. Was maintained.

Example 15
In Example 15, five polar solvents, benzyl alcohol, triethylene glycol, formic acid, DL-lactic acid, and oxalic acid were used as polar solvents, respectively. The aramid fabric was dyed on the basis of dyeing with a dye. In the present Example 15, the pre-dying process was first performed with the disperse dye with respect to the para aramid fabric similar to the said Example 1. FIG. Next, the para-aramid fabric after this pre-dying step was dyed with a vat dye and each polar solvent similar to those in Examples 12 and 14.

D1. Pre-dyeing step with disperse dye Unstained para-aramid fabric was desized and scoured in the usual manner, and dyed with disperse dye. Dyeing was performed by the dip dyeing method, and para-aramid fabrics were dyed using a high-temperature high-pressure dyeing tester mini color (manufactured by Tecsum Giken Co., Ltd.). For the staining solution, Kayalon Polyester Black ECX-300 (Nippon Kayaku Co., Ltd. disperse dye, CI No. unknown) 2.5% owf and Kayalon Polyester Black TN-200 (Nippon Kayaku Co., Ltd. dispersion) Dye, CI No. unknown) 2.5% owf was used in combination, and a pH 5 acetic acid / sodium acetate buffer was used.

  Dyeing was performed at a bath ratio of 1:20, and high-temperature high-pressure dyeing was performed at 135 ° C. for 60 minutes. The para-aramid fabric after dyeing was subjected to reduction washing in the same manner as dyeing with disperse dyes for ordinary polyester fibers. In the reduction cleaning, sodium dithionite 5 g / L as a reducing agent and sodium hydroxide 5 g / L were used in combination for 1 minute at 80 ° C. In Example 15, the reduction cleaning was repeated twice. Thereafter, washing with hot water, washing with water and drying were performed to obtain a para-aramid woven fabric pre-dyed with a disperse dye.

  Next, with respect to the para-aramid fabric subjected to pre-dying, benzyl alcohol, triethylene glycol, formic acid, DL-lactic acid, or oxalic acid is polar in the same manner as in Example 12 or Example 14, respectively. The para-aramid fabric of Example 15 dyed to an extremely dark black was obtained by performing a dyeing operation used as a solvent and reduction washing.

The dyed para-aramid fabric of Example 15 dyed as described above was evaluated in the same manner as in Example 1 above. Table 15 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 15, in Example 15 in which pre-dyeing with a disperse dye was made in comparison with Example 12 (see Table 12) or Example 14 (see Table 14) dyed only with vat dyes. In both cases, the dyeing density (total K / S value) was greatly improved, and the lightness (L ^* value) was reduced to 30 or less, and an extremely dark para-aramid fabric could be obtained. As shown in Table 15, this extremely dark para-aramid fabric has very good light fastness. In addition, in the para-aramid fabric of Example 15, the fluff on the fabric surface was dyed in an extremely dark color with both the vat dye and the disperse dye, and the surface quality of the fabric was further improved. Furthermore, although not shown in Table 15, in the dyed para-aramid fabric of Example 15, the properties of practical high-performance fibers can be obtained without causing uneven dyeing, dimensional changes, or significant deterioration in physical properties. Was maintained.

<< Example 16 >>
In Example 16, DL-lactic acid was used as a polar solvent, and an aramid fabric was dyed based on the above-described third embodiment (pre-dying with a cationic dye → dying with a vat dye). In this Example 16, first, a pre-dyeing process was performed with a cationic dye on the same para-aramid fabric as in Example 1 above. Next, the same dyeing operation with vat dye and DL-lactic acid as in Example 14 was performed on the para-aramid fabric after this pre-dyeing step.

D1. Pre-dyeing step with cationic dye The undyed para-aramid fabric was desized and scoured in the usual manner, and dyed with a cationic dye. Dyeing was performed by the dip dyeing method, and para-aramid fabrics were dyed using a high-temperature high-pressure dyeing tester mini color (manufactured by Tecsum Giken Co., Ltd.). In the staining solution, Kayacryl Navy RP-ED (cationic dye manufactured by Nippon Kayaku Co., Ltd., CI No. unknown) 5.0% owf is used, and sodium nitrate 25 g / L and a commercially available carrier are used in combination. A pH 5 acetic acid / sodium acetate buffer was used.

  Dyeing was performed at a bath ratio of 1:20, and high-temperature high-pressure dyeing was performed at 135 ° C. for 60 minutes. The para-aramid fabric after dyeing was washed with hot water and washed with water and dried to obtain a para-aramid fabric pre-dyed with a cationic dye.

  Next, the pre-dyed para aramid fabric was dyed in the same manner as in Example 12 using the same vat dye “Mikethren Blue BC super-fine” as in Example 1 above, 50 g / L. An application step was performed. The pickup rate at this time was 58% by weight. Further, the para-aramid fabric after the dye application step is subjected to a solvent treatment step using DL-lactic acid as a polar solvent, a heat treatment step and a reduction washing in the same manner as in Example 14 to obtain an extremely dark color. A para-aramid fabric of Example 16 dyed in navy blue was obtained.

<< Comparative Example 10 >>
For Example 16 above, a para-aramid fabric which was only dyed with a cationic dye was used as Comparative Example 10. Specifically, the dyeing step, the solvent treatment step, and the heat treatment step according to the present invention were all performed without performing any dyeing operation, and the same dyeing step with the cationic dye as in Example 16 was performed. The para-aramid fabric of Comparative Example 10 dyed in navy blue was obtained by carrying out reduction washing, hot water washing, and water washing in the same manner as above.

The dyed para-aramid fabrics of Example 16 and Comparative Example 10 dyed as described above were evaluated in the same manner as in Example 1 above. Table 16 shows the evaluation results of the total K / S value for evaluating the dyeing density, the lightness (L ^* value) for evaluating the degree of dark color, and the light fastness.

As can be seen from Table 16, in Example 16 dyed with a cationic dye and a vat dye, the dyeing density (total K / S value) was higher than that of Comparative Example 10 dyed with only a cationic dye, and the brightness was also high. (L ^* value) decreased to 30 or less, and an extremely dark para-aramid fabric could be obtained. On the other hand, the light fastness of Comparative Example 10 dyed with only the cationic dye is remarkably weak, whereas in Example 16 dyed with the vat dye in addition to the cationic dye, a large improvement in light fastness is observed. . Further, in the para-aramid fabric of Example 16, the fluff on the fabric surface was dyed in a very dark color with both the cationic dye and the vat dye, and the surface quality of the fabric was further improved. Further, although not shown in Table 16, in the dyed para-aramid fabric of Example 16, the properties of practical high-performance fibers can be obtained without causing dyeing unevenness, dimensional change, or significant deterioration in physical properties. Was maintained.

  As explained in the dyeing operations of Examples 1 to 16, the present invention can be applied to any of para-aramid fibers, para-copolymerized aramid fibers, and meta-aramid fibers, and these aramids. The fiber can be dyed to a practical dyeing concentration. Further, according to the present invention, dyeing unevenness, dimensional change, or deterioration of physical properties does not occur greatly in the aramid fiber after dyeing. Further, since a vat dye or sulfur dye having good dyeing fastness, particularly light fastness, is used, the dyeing fastness, especially light fastness, of the dyed aramid fiber is improved.

Further, by changing the use concentration and hue of the vat dye or sulfur dye to be used, it is possible to obtain a dyed product having a rich hue from light to dark. In particular, according to the present invention, para-aramid fiber or para-copolymerized aramid fiber, which has been considered difficult so far, can be dyed in an extremely dark color such as black or navy blue (for example, L ^* value is 30 or less). it can.

  Further, as a pre- and post-process of the method for dyeing aramid fibers according to the present invention, by performing a pre-dyeing step or a post-dyeing step with dyes other than vat dyes and sulfur dyes, fluff on the surface of the aramid fibers themselves is sufficiently dyed. The dyeing quality is improved and the dyeing density is further improved. On the other hand, when the aramid fiber is a mixed fiber with other chemical fiber or natural fiber, by performing these dyeing steps, the hue of the aramid fiber and the other fiber can be unified, and the dyed product Dyeing quality and dyeing density are further improved.

Therefore, according to the present invention, color fastness of dyed dyeing, in particular good light fastness, can provide a Senshokukata method of aramid fiber having a hue rich practical dyeing concentration . This is effective for the development of new uses for aramid fibers.

In implementing the present invention, not only the above-described embodiments but also the following various modifications may be mentioned.
(1) In each of the above embodiments, the solvent treatment process is performed after the dye application process, but the present invention is not limited to this, and the dye application process may be performed after the solvent treatment process.
(2) In each of the above embodiments, the aramid fabric is dried after the dye solution containing a vat dye or sulfur dye is applied to the aramid fabric, but the present invention is not limited to this. You may make it throw in a solvent treatment process, without drying a textile fabric.
(3) In each of the above embodiments, a lot of navy blue or black is used except for some vivid hues. However, these embodiments show that dark colors or extremely dark colors can be dyed. . Therefore, by changing the use concentration and hue of the vat dye or sulfur dye to be used, it is possible to obtain a dyed product of abundant hues from light to dark and including bright hues.
(4) In each of the above examples, the aramid fibers to which the vat dye or sulfur dye was added in the dye application step were put into the solvent treatment step that continued without washing. However, the vat dye or sulfur dye after the dye application step adheres to the aramid fiber with a certain degree of affinity. Therefore, the aramid fiber after the dye application step may be washed and then introduced into the solvent treatment step.
(5) In each of the above embodiments, there are those that perform reduction cleaning after the dyeing operation, but reduction cleaning may be performed only when necessary, and the prescription for reduction cleaning is not limited to alkaline. Alternatively, reduction cleaning with an acidic reduction prescription may be performed.
(6) In Examples 14 and 15 above, DL-lactic acid mixed with optical isomers was used as the polar solvent. However, the present invention is not limited to this, and D-lactic acid or L-lactic acid should be used. May be.
(7) In the above Example 5, Example 11 and Example 15, no carrier or deep dyeing agent is used for dyeing the disperse dye. In the present invention, pre-dying or post-dying is merely auxiliary dyeing, and it is not necessary to use a carrier or the like. However, various carriers used in normal aramid dyeing may be used in combination, and the dye may be further colored.
(8) In each of the above embodiments, the aramid fabric is dyed. However, the present invention is not limited to this, and may be a knitted fabric, a non-woven fabric or the like, or may be a yarn, cotton or the like.

Claims (3)

A dye applying step for applying a water-insoluble dye selected from vat dyes (excluding solubilized vat dyes) or sulfur dyes to aramid fibers;
A solvent treatment step of treating the aramid fiber with a treatment solution containing a polar solvent;
After this solvent treatment step, it has a heat treatment step to heat treat the aramid fiber if necessary,
In each of the above steps, without using the vat dye or the agent for reducing or water-solubilizing the sulfur dye, or operation,
Four dyeing operations shown below,
Dyeing operation 1: Dye application step → Solvent treatment step,
Dyeing operation 2: solvent treatment step → dye application step,
Dyeing operation 3: Dye application step → Solvent treatment step → Heat treatment step
Dyeing operation 4: Solvent treatment step → heat treatment step → dye application step,
And at least one dyeing operation is provided once or more,
The method for dyeing aramid fibers, wherein the polar solvent has a solubility parameter (δ) in the range of 18 to 32 (MPa) ^1/2 . A dye applying step for applying a water-insoluble dye selected from vat dyes (excluding solubilized vat dyes) or sulfur dyes to aramid fibers;
A solvent treatment step of treating the aramid fiber with a treatment solution containing a polar solvent;
After this solvent treatment step, it has a heat treatment step to heat treat the aramid fiber if necessary,
In each of the above steps, without using the vat dye or the agent for reducing or water-solubilizing the sulfur dye, or operation,
Four dyeing operations shown below,
Dyeing operation 1: Dye application step → Solvent treatment step,
Dyeing operation 2: solvent treatment step → dye application step,
Dyeing operation 3: Dye application step → Solvent treatment step → Heat treatment step
Dyeing operation 4: Solvent treatment step → heat treatment step → dye application step,
And at least one dyeing operation is provided once or more,
The polar solvent is selected from the group consisting of N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, benzyl alcohol, diethylene glycol, triethylene glycol, sulfuric acid, formic acid, lactic acid, and oxalic acid. A method for dyeing aramid fibers, characterized by comprising at least one kind. A method for dyeing aramid fibers according to claim 1 or 2,
A pre-dyeing step performed before the dyeing method or a post-dyeing step performed after,
A method for dyeing aramid fibers, wherein in the pre-dying step or the post-dying step, the aramid fibers are dyed with a dye other than a vat dye and a sulfur dye.