MX2013011267A - Method for dyeing aramid fibers and dyed aramid fibers. - Google Patents

Abstract

[Problem] To provide a method for dyeing aramid fibers which is applicable to any of para-aramid fibers, para-coaramid fibers, and meta-aramid fibers and by which aramid fibers are dyed in practical concentrations required for new applications of aramid fibers. The dyed aramid fibers have suffered neither considerable dyeing unevenness nor a considerable dimensional change nor a considerable decrease in material property. The dyed fibers further have satisfactory color fastness, in particular, light fastness. Also provided are dyed aramid fibers. [Solution] A dyeing method which comprises one or more dyeing operations each comprising a combination of the following steps: a dye application step in which a vat dye or a sulfur dye is applied to aramid fibers; a solvent treatment step in which the aramid fibers are treated with a treating liquid comprising a polar solvent; and a heat treatment step in which after the solvent treatment step, the aramid fibers are heat-treated according to need.

Description

METHOD FOR DYING ARAMIDA FIBERS AND ARAMIDA FIBERS COLORED FIELD OF THE INVENTION The present invention relates to a method for dyeing aramid fibers, in particular, to a dyeing method which can dye the aramid fibers with an appropriate depth of color. The present invention also relates to aramid fibers dyed by the method.

BACKGROUND OF THE INVENTION A fully aromatic polyamide fiber is also referred to as aramid fiber, which has high strength and high modulus of elasticity, and excellent heat resistance, dimensional stability, chemical resistance, etc., and has been used for multiple uses such as fiber industrial use. Aramid fibers can be roughly classified into three types of aramid fibers of the para type (polyparaphenylene terephthalamide fiber, etc.), copolymerized aramid fibers of the para type (fibers copolymerized with polyparaphenylene terephthalamide and 3,4'-oxydiphenylene terephthalamide). ), and, meta-aramid fibers (polymethaphenylene isophthalamide fibers or copolymerized fibers containing the same as the main component, etc.) depending on the position of the amide bond attached to the aromatic ring.

Aramid fibers of the para type are particularly strong and excellent in modulus of elasticity, and have been widely used for protective clothing such as bullet-proof vests, etc., friction materials such as brake pads, etc. reinforcement of an optical fiber, or materials such as ropes and nets that require a particularly high strength. In addition, copolymerized aramid fibers of the para type have been used for the same uses of aramid fibers of the para type, and show their characteristics for uses where chemical stability and fatigue resistance are required. They have been widely used, for example, for rubber reinforcement materials, ropes, and civil engineering and construction applications. On the other hand, the aramid fibers of the meta type are particularly excellent in heat resistance, flame retardancy, chemical resistance, etc., and have been widely used for various types of protective clothing for work such as firemen suits, etc.

These aramid fibers have a rigid molecular structure and a high crystallinity, and an appropriate color depth can not be obtained by the same dyeing method that is applied to general fibers, and it can not be said that the color retention of the dyed product obtained is suitably sufficient. Therefore, in the appropriate one, it is manufactured as fibers dyed with a paste (fibers produced by adding a dye in the previous phase to the spinning stage) and is mainly used in the fibers of aramid of meta type. Such dyed fibers are limited in tone, so there is a problem that they can not sufficiently correspond to various shades required to develop new applications of various types of protective clothing for work or aramid fibers. In addition, in the aramid fibers of the para type or the copolymerized aramid fibers of the para type, and further including the fibers dyed with paste, fibers having an appropriate color depth such as black or blue have not yet been produced in an industrial manner. Marine.

On the other hand, a specific dyeing method for dyeing aramid fibers has been investigated. For example, there is a method of dyeing at high temperature and high pressure that also uses a dye carrier such as benzaldehyde, acetophenone and benzyl alcohol, or a method of dyeing with solvents in which the dyeing is carried out in a polar solvent such as a?,? - dimethylformamide, dimethyl sulfoxide and cyclohexane at high temperature. However, these dyeing methods using a dye carrier or a polar solvent at high temperatures are mainly methods for dyeing aramid fibers of the meta type., and are insufficient to dye aramid fibers of aramid type or copolymerized aramid fibers of the para type. In addition, during the dyeing of the aramid fibers of the meta type, when the dyeing method using these dye carriers or polar solvents at high temperature is used, it involves the problems of causing color inconsistency of the dyed product, and dimensional change or decrease in physical properties due to shrinkage, etc.

Accordingly, several novel dyeing methods have been investigated even now. For example, in the following Patent Document 1, a dyeing method has been proposed in which the aramid fibers are pre-treated with concentrated sulfuric acid, subsequent to the neutralization, they are injected into a dye bath while a predetermined moisture content is maintained without drying, and are stained by a disperse dye or a cationic dye. Furthermore, in the following Patent Document 2, a dyeing method has been proposed in which a portion of vat dyes which are stable at high temperature is used, and the dyeing is carried out under extremely high temperature conditions of 300 at 400 ° C.

Prior art document Patent document Patent Document 1: JP Sho 52-37882A Patent Document 2: JP 2010-59556A BRIEF DESCRIPTION OF THE INVENTION Problems that will be solved by means of the invention Incidentally, the dyeing method of the aforementioned Patent Document 1 provides a dyed product with various shades. However, the dyeing method of the aforementioned Patent Document 1 employs a dye such as a disperse dye and a cationic dye, etc., and there is a problem that the color retention, in particular, the color retention to the light is bad. In contrast, the dyeing method of the aforementioned Patent Document 2 uses a tub dye that provides good color retention in light, but the dyeing temperature is extremely high so that the dyeing that can be used for the method it is limited, so there is a problem that it can not correspond sufficiently to several tones.

In addition, the dyeing method of the aforementioned Patent Document 2 involves the problems that a specific device is required and that the cost of energy becomes high. Furthermore, the dyeing method of the aforementioned Patent Document 2 is still not sufficient to dye the aramid fibers of the type for or the copolymerized aramid fibers of the type with an appropriate depth of color. On the other hand, when the dyeing method of the aforementioned Patent Document 2 is applied to the aramid fibers of the meta type, the fibers are treated at a remarkably high temperature. greater than the vitreous transition temperature thereof, so that the problem arises that the physical properties of the fibers are markedly reduced.

Accordingly, the present invention has been made in view of the problems mentioned above, and an object thereof is to provide a method for dyeing aramid fibers and dyed aramid fibers, which method is a dyeing method which can be applied to any of aramid fibers of the para type, copolymerized aramid fibers of the para type and aramid fibers of the meta type, which can be dyed in an appropriate color depth required to develop new applications of the aramid fibers, and the color inconsistency , the dimensional change, or the reduction of physical properties are not generated significantly in the aramid fibers after dyeing, in addition, the color retention of the dyed product, in particular, the retention of color to light is good.

Means to solve problems To solve the aforementioned problems, the present inventors have studied intensively, and as a result, have found that the aforementioned problems can be solved by the use of a tub tincture or a sulfur dye having good color retention to light. dyeing the aramid fibers, and by using a step of providing these dyes on the aramid fibers, and a stage of treating the aramid fibers with a solvent polar in combination, whereby the present invention has been achieved.

That is, a method for dyeing aramid fibers according to the present invention comprises, according to the definition of claim 1, a step of providing dyeing in which a tub dye or a similar dye is provided in the fibers of aramid, a stage of treatment with solvents in which the aramid fibers are treated by a treatment solution comprising a polar solvent, and after the treatment step with solvents, a heat treatment step in which the aramid fibers are subjected to a heat treatment, if necessary, and having at least one dyeing operation from the following four operations of had, dyeing operation 1: tincture provision stage followed by a solvent treatment step, dyeing operation 2: stage of treatment with solvents followed by a stage of dyeing provision, dyeing operation 3: dyeing step followed by a solvent treatment step followed by a heat treatment step, dyeing operation 4: solvent treatment step followed by a heat treatment step followed by a dyeing step, once or more.

In addition, the present invention is, according to the definition of claim 2, in the method for dyeing aramid fibers according to claim 1, wherein the polar solvent has a value of a solubility parameter (d) within a range of 18 to 32 (MPa) 1/2 .

Additionally, the present invention is, according to the definition of claim 3, in the method for dyeing the aramid fibers according to claim 1, wherein the polar solvent is at least one selected from the group consisting of N- methylpyrrolidone, NN-dimethylformamide,?,? -dimethylacetamide, dimethyl sulfoxide, benzyl alcohol, diethylene glycol, triethylene glycol, sulfuric acid, formic acid, lactic acid and oxalic acid.

In addition, a method for dyeing aramid fibers according to the present invention comprises, according to the definition of claim 4, the method for dyeing aramid fibers according to any of claims 1 to 3, and a prepreading step. - dyeing which is carried out before the method for dyeing or a post-dyeing step which is carried out after it, wherein the aramid fibers are dyed by a dye different from the tin dye and the sulfur dye in the pre-dyed stage or in the post-dyed stage.

Additionally, aramid fibers dyed in accordance with the present invention comprise, according to the definition of claim 5, dyeing by the method for dyeing aramid fibers according to any of claims 1 to 3.

In addition, the present invention is, according to the definition of claim 6, in the aramid fibers dyed according to claim 5, the brightness (value of L *) in a colorimetric system of L * a * b * is 38 or less.

Furthermore, the present invention is, according to the definition of claim 7, in the aramid fibers dyed according to claim 5, wherein the brightness (value of L *) in a colorimetric system of L * a * b * is 30 or less.

Additionally, the aramid fibers dyed according to the present invention comprise, according to the definition of claim 8, fibers dyed by the method for dyeing aramid fibers according to claim 4.

In addition, the present invention is, according to the definition of claim 9, in the aramid fibers dyed according to claim 8, wherein the brightness (value of L *) in a colorimetric system of L * a * b * is 30 or less.

Effects of the invention According to the present invention, the method can be applied to any of the aramid fibers of the para type, the copolymerized aramid fibers of the para type or the aramid fibers of the meta type, and these aramid fibers can be dyed with a depth of appropriate color. In addition, according to the present invention, the color inconsistency or the dimensional change, or the reduction of physical properties is not generates a remarkable way in the aramid fibers after dyeing.

In addition, because a tub tincture or a sulfur tincture having a good color retention is used, in particular, retention of color to light, color retention, in particular, color retention in light Aramid fibers stained becomes good.

In addition, by changing a used concentration and a tone of the tub dye or the sulfur dye to be used, a product dyed from a pale color to a dark color with various shades can be obtained.

In particular, according to the present invention, the aramid fibers of I type for or the copolymerized aramid fibers of the type for can be dyed with a very dark color such as black and navy blue which had been considered difficult.

Here, as one of the methods to evaluate a dark color such as black and navy blue, there is luminosity (value of L *) in a colorimetric system of L * a * b * that had been standardized by the International Commission on Illumination (CIE) by its initials in English) in 1976, and in Japan, had been adopted in JIS Z8729. This value of L * is shown in the range of 100 (white) to 0 (black), and a smaller L * value can be evaluated to be a dark color.

For example, in fibers dyed with a paste of the commercially available meta-type aramid fibers or para-copolymerized aramid fibers, a L * value of 25 to 27 has been obtained in the very dark color such as black or Navy blue. Therefore, in the present invention, the L * value of 38 or less can be judged as a dark color, and in addition, the L * value of 30 or less can be judged as a very dark color. In the present invention, not only the aramid fibers of the meta type but also the aramid fibers of the para type or the copolymerized aramid fibers of the para type can be dyed in a dark color or a very dark color not by the spinning method. dyed but yes by the dyeing method.

In addition, as a prior or subsequent step the method for dyeing aramid fibers according to the present invention, a pre-dyeing step or a post-dyeing step can be carried out by a different dyeing of the tub dye and the sulfur tincture. By carrying out these dyeing steps, the lint on the surface of the aramid fibers themselves is dyed more aptly, so that the dyeing quality and the color depth are further improved. On the other hand, when the aramid fibers are mixed with the other chemical fibers or natural fibers to form a mixed fiber, the tone of the aramid fibers and that of the other fibers can be unified by subjecting them to these stages of dyeing, by which also improves the dyeing quality and the color depth of the dyed product.

Accordingly, according to the present invention, a method can be provided for dyeing aramid fibers and dyed aramid fibers having good color retention, in particular, color retention in the light of the dyed product, abundant in tone and with a appropriate color depth. This is effective to develop a novel use of the fibers of aramid MODALITIES FOR CARRYING OUT THE INVENTION In the aramid fibers that will be dyed by the dyeing method according to the present invention, for example, as para-type aramid fibers, there may be mentioned Twaron (Registered Trade Mark) available from Teijin Limited, and Kevlar (Trade Mark) available by Du Pont Kabushiki Kaisha, and as copolymerized aramid fibers of the para type, mention may be made of Technora (Trade Mark) available from Teijin Limited. On the other hand, like meta-aramid fibers, mention may be made of Conex (Registered Trademark) available from Teijin Limited, and Nomex (Registered Trademark) available from Du Pont Kabushiki Kaisha.

In the present invention, the aramid fibers may be of any shape, and may be in the state of fibers such as filament fibers, staple fibers, etc., or in the state of a fiber structure such as a filament yarn, spinning, fabrics , woven fabrics, non-woven fabrics, rope, a net, etc. In addition, it may be any of aramid fibers of the para type, the copolymerized aramid fibers of the para type or the aramid fibers of the meta type, or in the mixed fiber state thereof. In addition, it can be in the mixed fiber state of the aramid fibers and the other chemical fibers or natural fibers.

In the present invention, the aramid fibers are dyed by a tincture of tub or a tincture of sulfur. These vat dyes or sulfur dyes are each dyes that have good color retention, in particular, excellent in the retention of color to light.

Here, tub dye is generally used for dyeing cotton, etc., and in a dye essentially insoluble in water, but is reduced by a reducing agent such as sodium dithionite, etc., to adsorb on the fibers in the dye. form of leuco acid or leuco salt, and therefore, it is oxidized and applied to the fibers again as a water-insoluble tincture.

On the other hand, the tincture of sulfur is a dye containing a sulfur atom in the molecule, and is generally used for dyeing cotton, etc. This sulfur tincture is also a dye essentially insoluble in water, but is reduced by a reducing agent such as sodium sulfide, etc., to become soluble in water to adsorb on the fibers, and is therefore oxidized and applied in the fibers again as a water-insoluble tincture.

However, in the present invention, the tub dye or the sulfur dye is used without reduction and applied to the aramid fibers in the state of a water-insoluble dye. Tub tincture or sulfur tincture does not have a strong affinity as if it were, which can be applied to aramid fibers as such. Furthermore, when the tub dye or the sulfur dye is reduced to make it soluble in water, the affinity to the aramid fibers is further reduced.

In the present invention, however, by employing a solvent treatment of the aramid fibers using a polar solvent in combination, the dyeing property of the tin dye or the sulfur dye in the aramid fibers can be considered. it would be revealed Additionally, when a heat treatment is carried out, if necessary, after treatment with solvents, the dyeing property of the tub dye or the sulfur dye in the aramid fibers is improved in some cases. However, in the present phase, the dyeing mechanism of the tub dye or the sulfur dye in the aramid fibers according to the present invention is not yet clear.

Next, the method for dyeing aramid fibers according to the present invention will be explained based on the corresponding modalities. (1) First mode The method of dyeing according to the first embodiment comprises a step of providing dyeing in which a tincture of tub or a tincture of sulfur is provided in the aramid fibers, and a step of treatment with solvents in which the fibers of Aramid are treated by a treatment solution containing a polar solvent. The order of this stage of dyeing provision and solvent treatment step is not particularly limited, and it is preferred to carry out the solvent treatment step after the dyeing step. In this first embodiment, the step of providing dyeing in which the tub dye or the sulfur dye is provided in the aramid fibers in a non-reduced state is carried out first, subsequently the solvent treatment step is carried out in which the aramid fibers that had been provided with the tub dye or the sulfur dye are treated by a treatment solution containing a polar solvent In this first embodiment, this series of steps is generally referred to as "dyeing operation 1". Incidentally, this dyeing operation 1 (dyeing step followed by a solvent treatment step) can be carried out only once, or can be repeated a plural number of times, depending on the need. By repeating this dyeing operation a plural number of times, aramid fibers with a denser color can be obtained.

A. Stage of provision of tincture For the tin dye to be used in the tincture provision stage, a dye generally used for dyeing cotton, etc., can be mentioned. Further, in the present invention, it is preferred to use a super fine dye having an average dispersed particle diameter in the dispersion state in a dye solution of several micrometers or less, more preferably 1 μm or less. In addition, among these vat dyes, it is more preferred to use, in particular, each tincture of C. I. Tina Yellow 33, C. I. Tina Coffee 1, C. I. Tina Red 1, C. Tina Violet 9, C. I. Tina Blue 4, C. I. Blue of Tub 6, C. I. Blue of Tub 20, C. I. Green of Tub 1, C. I. Green of Tub 3, C. I. Black of Tub 8, C. I. Black of Tub 25, etc.

On the other hand, for the dyeing of tub that will be used in the stage of dyeing provision can be mentioned a dye generally used for dyeing cotton, etc. In addition, among these sulfur dyes, it is more preferred to use, in particular, each Dye of Yellow CI of Sulfur 16, CI Orange Sulfur 1, Red CI of Sulfur 6, CI Azul de Sulfur 7, CI Azul de Sulfur 15, CI Sulfur Black 11, etc.

In the step of providing a dye in the aramid fibers, the tin dye or the sulfur dye is not in a reduced state, and is a water-insoluble dye. Accordingly, to provide a dyeing in the aramid fibers in the dyeing stage, a dyeing solution is used in which the tin dye or the sulfur dye is dispersed in water. In this coloring solution, the vat dye or the sulfur dye is contained in a non-reduced dispersed state, and, if necessary, a migration preventive agent can be used in combination with it. To provide the coloring solution, any methods can be employed, and it can be simple immersion, immersion and squeezing of liquid, or it can be provided by spraying, ink jet, etc.

If necessary, the aramid fibers that had been provided with the dye solution are then dried. The drying of the aramid fibers can be carried out at any temperature, and they are generally dried at a temperature of about 80 ° C to 120 ° C. In addition, after drying the aramid fibers, a heat treatment at high temperature (which is different from the heat treatment step mentioned below) can also be carried out. If not, the aramid fibers that had been provided with the coloring solution can be subjected to a heat treatment q a temperature of about 120 ° C to 200 ° C, or a higher temperature than the previous one, which also acts as a process of drying.

If the drying temperature is less than 80 ° C, a longer time is required to dry the aramid fibers. On the other hand, if the treatment temperature is higher than 200 ° C, in particular, it is higher than 280 ° C, in some cases a decrease in the physical properties of the aramid fibers occurs. In particular, in the case of aramid fibers of the meta type, a heat treatment at a temperature exceeding its glass transition temperature causes the decrease in physical properties. In addition, if they are treated at an extremely high temperature, the tincture of the tub or the sulfur tincture decomposes in some cases so that the tone changes markedly.

On the other hand, the drying time can optionally be selected depending on a type or shape of the aramid fibers, and a drying temperature, and is not a particular problem. The drying time is generally a time of about 30 seconds to 30 minutes. For example, when the aramid fibers are fabrics, the drying time is preferably about 1 minute to 10 minutes. minutes when the drying temperature is 105 ° C.

In the phase where drying is complete, the tub dye or the sulfur dye is in the state in which it is uniformly provided over the aramid fibers. However, the aramid fibers are not in the state in which they are completely stained by the tin dye or the sulfur dye. However, at this stage, the tub tincture or the sulfur tincture is bound to the aramid fibers with a certain degree of affinity, while not yet achieving dyeing. Here, the reason why the tub dye or the sulfur dye is bound to the aramid fibers is not clear, but it can be considered that these dyes are bound on the surface of the aramid fibers by a physical action such as a intermolecular force in an insoluble state in unreduced water.

Here, when the aramid fibers are in a state of fabric, a series of treatments can be carried out by traversing the fabrics in the longitudinal direction. In this case, the fabrics of aramid fibers are first immersed in a bath in which a dye solution has been poured. Subsequently, an excess of coloring solution is squeezed into the fabrics of aramid fibers through a means for squeezing such as a juicer, etc. In accordance with these procedures, fabrics of aramid fibers that have been provided with a predetermined amount of the dye solution are obtained. Subsequently, the fabrics of aramid fibers after being squeezed are placed in a heat treatment device such as a clothesline of brooches while running and they dry there.

B. Stage of treatment with solvents The aramid fibers after the dyeing step are injected into the subsequent stage of solvent treatment without washing. In the stage of treatment with solvents, the aramid fibers are treated by a polar solvent. In the present invention, the polar solvent is widely interpreted, and will be referred to as a substance having a polar functional group in the molecular structure of a solvent. For example, among the polar solvents, there may be mentioned an aprotic polar solvent such as N-methylpyrrolidone, α, β-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, acetophenone, methyl ethyl ketone, N-butylphthalamide, N-isopropylphthalamide, N-methylformanilide. , etc. These polar aprotic solvents can be used alone, or in combination of two or more, or they can be used by the formulation with the following mentioned protonic polar solvents (s). Among these aprotic polar solvents, such as a solvent which hardly causes shrinkage or diminution of the physical properties of the aramid fibers, and which is particularly effective for applying the tub dye or the sulfur dye, preferably N, N is mentioned. -dimethylformamide,?,? - dimethylacetamide and dimethylsulfoxide.

In addition, among the polar solvents, the polar proton solvent can be mentioned as protonic acids such as sulfuric acid, formic acid, lactic acid, maleic acid, oxalic acid, etc .; alcohols such as 1-propanol, 1-octanol, benzyl alcohol, DL-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, 2- (dichlorophenoxy) ethanol, etc .; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, PEG200, PEG400, PEG600, propylene glycol, polypropylene glycol, etc., and also a monoether or monoster of glycol such as 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 ether, dipropylene glycol monophenyl ether, cellosolve, n-butyl cellosolve, hydroxyethyl acrylic, etc. These protonic polar solvents can be used alone or in combination of two or more, or can be used by the formulation with the aforementioned polar aprotic solvents (s). Among these protonic polar solvents, as a solvent that hardly causes shrinkage or decrease in the physical properties of the aramid fibers, preferably benzyl alcohol, diethylene glycol, triethylene glycol, sulfuric acid, formic acid, lactic acid and oxalic acid are mentioned.

In addition, as a quantitative index showing the polarity of the polar solvent used in the present invention, a solubility parameter (d). In the present, it is preferred to use a polar solvent having a solubility parameter value within the range of d = 18 to 32 (MPa) 2. In addition, it is more preferred to use a polar solvent having a value of the solubility parameter within from the range of d = 19 to 28 (MPa) 1 2. Here, for example, the value of the solubility parameter of the aramid fibers of type for will be d = 23 (MPa) 1/2 (JE Mark, Manual Physical Properties of Polymers New York: Woodbury, 1996.). Consequently, it appears that an action of the polar solvent on the aramid fibers is caused by the fact that the value of the solubility parameter of the polar solvent is within the aforementioned range, which is close to the value of the solubility parameter of the polar solvents. Aramid fibers. According to the fact, the coloring property of the tub dye or the sulfur dye on the aramid fibers is improved, whereby aramid fibers having a more appropriate color depth can be obtained.

These polar solvents can be used alone or can be used by mixing two or more solvents as mentioned above. In addition, a concentration of the polar solvent that will be used in the treatment with solvents can be optionally selected depending on the type or shape of the aramid fibers to be treated, and the temperature treatment, and in general, it is preferred that it contain 40% by weight to 100% by weight, and more preferably containing 50% by weight to 100% by weight. Please note that oxalic acid is a solid that it generally has water in the form of a crystal, and its solubility is low. Accordingly, as far as oxalic acid is concerned, it is preferred to use an aqueous solution of about 10% by weight.

On the other hand, in relation to the sulfuric acid that will be used in the manufacturing stage of aramid fibers of type para, it is necessary to limit the concentration that will be used. In this stage of treatment with solvents, it is preferred to use an aqueous solution of sulfuric acid with a concentration of 70% by weight to 90% by weight. In addition, it is also preferred to use an aqueous solution of sulfuric acid with a concentration of 75% by weight to 85% by weight.

Further, when the aramid fibers mainly comprise aramid fibers of the meta type, it is more preferred to use an aqueous solution of sulfuric acid with a concentration of 75% by weight to 80% by weight.

When the concentration of the polar solvent is within the aforementioned range, the color depth is placed within a relatively stable range, and even if the concentration of the polar solvent fluctuates slightly, the depth of color does not change so markedly. Accordingly, a stable industrial production can be performed when the concentration of the polar solvent is within the range mentioned above.

Here, for the polar solvent diluent any material can be used as long as it is compatible with the polar solvent that is will use, and water is generally used. In the case of certain type of polar solvents, for example, N-methylpyrrolidone, etc., by means of mixing a certain amount of water, a denser dyed product can be obtained. On the other hand, it is not preferred that the concentration of the polar solvent is lower than the aforementioned range, and that the amount of water in the solvent treatment solution is increased because in some cases the tin dye or the tincture of Sulfur bound to the aramid fibers in the step of providing dyeing sedimented in the solution of treatment with solvents.

A polar solvent treatment temperature can be optionally selected depending on the type or shape of the aramid fibers to be treated, and the treatment time, and is generally treated at a temperature of 0 ° C to 70 ° C. In addition, a temperature of 10 ° C to 60 ° C is preferred. When sulfuric acid is used, the temperature of the aqueous solution of sulfuric acid can be a temperature of 0 ° C or higher and 50 ° C or lower, and more preferably at a temperature of 0 ° C or higher and 30 ° C or lower .

When the temperature of the polar solvent is within the range mentioned above, the color depth is within a relatively stable range, and even if the temperature of the polar solvent fluctuates slightly, the color depth does not change so markedly. Accordingly, stable industrial production can be performed when the temperature of the polar solvent is within the range mentioned above. On the other hand, if the temperature of the polar solvent is higher at the range mentioned above, sometimes a decrease in the physical properties or an extreme shrinkage of the aramid fibers occurs. In addition, by slightly varying the temperature of the polar solvent, the depth of color sometimes changes markedly. It is thought that a high temperature of the polar solvent causes a remarkable change in the molecular structure of the aramid fibers.

In addition, the treatment time of the solvent treatment can be optionally selected depending on the concentration and temperature of the polar solvent, and generally treated with a time of about 0.1 seconds to 30 minutes. Additionally, the treatment time of the solvent treatment is preferably about 1 second to 5 minutes. Even if the treatment time of the solvent treatment is approximately 0.1 second, the effects of the solvent treatment can be maintained. Therefore, when the treatment time of the solvent treatment is a time from about 0.1 seconds to 30 minutes, even if the time of treatment fluctuates slightly, the depth of color does not change so markedly, and the fibers can be dyed with an appropriate depth of color.

Accordingly, the treatment time of the solvent treatment is preferably controlled within the predetermined range. Accordingly, the aramid fibers treated by the polar solvent are preferably washed quickly. In addition, when the treatment is taken to Because of the sulfuric acid, the fibers are preferably neutralized and washed quickly. Here, the washing of the aramid fibers can be carried out by means of washing with water or washing with hot water, and for the purpose of extracting the tincture of the tub or the tincture of sulfur which is bound on the surface of the fibers. Aramid fibers in bleached state, the washing with reduction can be carried out.

Here, when the aramid fibers are in the fabric state, the solvent treatment can be carried out by traversing in the longitudinal direction. In this case, the fabrics of aramid fibers run through first are immersed in a bath filled with a treatment solution containing a polar solvent. Subsequently, an excess treatment solution is squeezed out of the aramid fiber fabrics by a means for squeezing such as a juicer, etc. Then, after squeezing, the fabrics of aramid fibers are introduced into a continuous washing device while running, and are subjected to washing, neutralization washing or washing with reduction. When this series of treatments is carried out continuously, the time from immersion to washing, neutralization washing or washing with reduction can be controlled in a stable manner. Accordingly, the treatment time of the immersion treatment can be maintained at a preferred rate and a uniform solvent treatment can be carried out.

By the way, the action of these treatments with solvents is not clear, but it can be thought that, when treating the aramid fibers with the polar solvent having a concentration as mentioned above, the intermolecular bonds of the aramid fibers having a rigid molecular structure and high crystallinity are partially relaxed to form many small voids. On the other hand, it can also be thought that these polar solvents act on the molecules of the dye. According to the above, the tub dye or sulfur dye attached to the surface of the fibers by the dyeing stage is thought to be applied in the small hollows of the aramid fibers by the solvent treatment step .

In this first embodiment, tub tincture or sulfur tincture is used which has particularly good color retention in light as mentioned above. Accordingly, by carrying out this series of dyeing operation 1 (dyeing step followed by a solvent treatment step), a dyed product of the aramid fibers having a color depth can be obtained. appropriate, and that they have good color retention, particularly good color retention in light. In particular, the dyeing method according to the present invention is a specific dyeing method that has never been in conventional dyeing methods, and never uses the means of adsorption by reduction which is the inherent dyeing mechanism of the dyeing. of tub or tincture of sulfur.

In addition, by repeating the dyeing operation 1 mentioned above (dyeing provision stage followed by a step of treatment with solvents) can be improved a plural number of times, the color depth of the aramid fibers. That is, on the aramid fibers dyed once by the dyeing operation 1 according to the aforementioned method, again a second time the dyeing operation is carried out, whereby fibers with a denser color can be obtained. Additionally, if the same dyeing operation 1 is repeated again, the color depth can be further improved. According to the above, the color retention of the product dyed to a dense color can be maintained in a good condition. (2) Second modality The method of dyeing according to this second embodiment comprises a step of providing dyeing in which the tin dyeing or the sulfur dyeing is provided on the aramid fibers, a stage of treatment with solvents in which the aramid fibers they are treated by a treatment solution containing a polar solvent, and a heat treatment step in which the aramid fibers after the treatment step with solvents are subjected to heat treatment. In this second embodiment, this series of stages is generically referred to as "dyeing operation 3". Incidentally, the dyeing operation 3 stage of dyeing provision followed by a treatment step with solvents followed by a heat treatment step) can be carried out only once, or it can be repeated a plural number of times, depending on the need.

By repeating this dyeing operation a plural number of times, aramid fibers with a denser color can be obtained.

A. Stage of provision of tincture In the dyeing stage of this second embodiment, the same operations are carried out as those of the dyeing stage in the first modality mentioned above.

B. Stage of treatment with solvents The treatment step with solvents in this second embodiment is carried out by the same operations as those of the solvent treatment stage in the first modality mentioned above. Incidentally, in this second embodiment, the aramid fibers after solvent treatment are introduced in the subsequent heat treatment step without washing, neutralization washing or reduction washing being carried out.

C. Heat treatment stage After the solvent treatment step mentioned above, the aramid fibers have already been dyed by the tub dye or the sulfur dye. Here, when carrying out the heat treatment, it can be thought that the application of the tub dye or the sulfur dye over the aramid fibers is improved so that the dyed product becomes firmer. However, if sulfuric acid is used as a polar solvent, the strength of the fiber is markedly reduced so that heat treatment can not be carried out.

The heat treatment can be a dry heat treatment or a wet heat treatment, and dry heat treatment is generally preferred. The heat treatment is preferably carried out at a temperature of 50 ° C or higher and 200 ° C and lower. In the heat treatment step, the aramid fibers are treated in the state where the polar solvent binds to them, so that if it is higher than 200 ° C, it is considered that a decrease in the physical properties of the fibers is caused. Aramid fibers so this is not preferred. Also, if treated at an extremely high temperature, the tincture of tub or sulfur tincture sometimes breaks down and the tone changes markedly.

On the other hand, the treatment time of the heat treatment can be optionally selected depending on the type or shape of the aramid fibers, and the type of tub tincture or sulfur tincture to be used, and it does not become a particular problem and it is generally carried out with a time of approximately 30 seconds to 30 minutes. Additionally, the treatment time of the heat treatment preferably is a time from about 30 seconds to 5 minutes. Even if the treatment time of heat treatment is a time of about 30 seconds, the effects of heat treatment can be maintained. Therefore, if the treatment time of treatment with heat is a time of about 30 seconds to 30 minutes, even when the treatment time fluctuates slightly, the color depth is not so noticeably modified and the fibers can be dyed with an appropriate depth of color.

Here, when the aramid fibers are in the fabric state, the aramid fibers after the aforementioned solvent treatment step can be introduced into a continuous heat treatment device while running the same to carry out the heat treatment. . When the series of treatments from the solvent treatment stage mentioned above to the heat treatment step is carried out continuously, the treatment time can be controlled stably from the immersion in the solvent to the heat treatment , the treatment times of the solvent treatment and the heat treatment can be maintained at a preferred rate, and solvent treatment and heat treatment can be carried out uniformly.

Here, the action of solvent treatment and heat treatment in combination is not clear, but it can be thought that, by treating the aramid fibers with the polar solvent having a concentration as mentioned above, the intermolecular bonds of the fibers of Aramid that have a rigid molecular structure and high crystallinity partially relax to form many small holes. On the other hand, it can also be thought that the action of the polar solvent on the molecules of Tincture is increased by heat treatment. In accordance with the foregoing, the tub dye or the sulfur dye bonded to the aramid fibers by the solvent treatment step is believed to be firmly applied to the small hollows of the aramid fibers by the heat treatment step. after the stage of treatment with solvents.

Next, the aramid fibers after the heat treatment step are washed to remove the remaining polar solvent. The washing can be carried out by washing with water or washing with hot water, and for the purpose of extracting the tincture of the tub or the sulfur dye that is bonded onto the surface of the aramid fibers in an undyed state, an washing with reduction.

In this second embodiment, as mentioned above, tub tincture or sulfur tincture is used which has a particularly good color retention in light. According to the above, by carrying out this series of steps of the dyeing operation 3 (dyeing step followed by a solvent treatment step followed by a heat treatment step), a dyed product of the aramid fibers can be obtained. They have an appropriate color depth, and they have good color retention, particularly good color retention in light. In particular, the dyeing method according to the present invention is a specific dyeing method which has never been in conventional dyeing methods, and never uses the means of adsorption by reduction which It is the inherent dyeing mechanism of the tub tincture or the sulfur tincture.

In addition, by repeating the aforementioned dyeing operation 3 (dyeing step followed by a solvent treatment step followed by a heat treatment step) a plural number of times, the color depth of the dye fibers can be improved. aramid That is, if on the aramid fibers dyed once by the dyeing operation 3 according to the aforementioned method, a second dyeing operation 3 is carried out, aramid fibers with a denser color can be obtained. Additionally, if the same dyeing operation 3 is repeated again, the color depth can be further improved. According to the above, the color retention of the product dyed to a dense color can be maintained in a good condition. (3) Third modality The dyeing method according to this third embodiment has a pre-dyeing step which dyes the aramid fibers with a different dyeing different from the tin dyeing or the sulfur dyeing before the dyeing operation 1 or the operation of dyeing. dyeing 3 explained in the first embodiment mentioned above or in the second embodiment mentioned above. Incidentally, the dyeing operation mentioned above or the dyeing operation 3 carried out after the pre-dyeing step can be carried out only once, or it can be repeated a plural number of times, depending on the need. By repeating the dyeing operation 1 or the dyeing operation 3 a plural number of times, aramid fibers with a denser color can be obtained.

D1. Pre-dyeing stage In the dyeing method according to this embodiment, a pre-dyeing step is first performed on the faded aramid fibers. In this pre-dyeing step, a solution containing another dye different from the tin dye and the sulfur dye is used. The dyeing method of the pre-dyeing step can be any method, dyeing is mainly carried out by dyeing with paste. A prescription of the dyeing solution to be used in the pre-dyeing step may be the same as that of the dyeing to be used in the ordinary dyeing method. Accordingly, when the same aramid fibers, in the same manner as in the conventional dyeing method of the aramid fibers, a dye carrier can be used in combination. On the other hand, when the aramid fibers are mixed with the other chemical fibers or natural fibers to form a mixed fiber, and the other fibers to be dyed, the ordinary dyeing method on the other fibers can be carried out.

When the same aramid fibers will be dyed in the pre-dyed step, any dyes can be used as a dye to be used as long as it is a dye having an affinity with the aramid fibers. For example, a disperse dyeing, a cationic dyeing or an acid dyeing, etc., may be preferably used in a similar manner as in the dyeing of the usual aramid fibers. In particular, it is preferred to use a dye that has been selected as a dye for the aramid fibers in the aspects of dyeing and color retention properties. On the other hand, when the aramid fibers are mixed with the other chemical fibers or natural fibers to form a mixed fiber, and the other fibers will be dyed, a dyeing suitable for the other fibers can be used. For example, when the other fibers are polyester fibers, a disperse dye will be used. In addition, when the other fibers are cotton or rayon fibers, a reactive dye or direct dyeing, etc. may be used.

When the same aramid fibers will be dyed, the process can be performed so that the aramid fibers are thrown into the dye solution containing a dye, the temperature of the dye solution is increased at dyeing temperature, and the dyeing temperature is maintained for a predetermined time. The dyeing temperature can be adjusted depending on the type or shape of the aramid fibers, and, of the type and depth of color to be used, and can generally be a temperature of 80 ° C to 150 ° C. In addition, the temperature is preferably 100 ° C to 140 ° C, and more preferably the temperature is 120 ° C to 135 ° C. If the temperature exceeds 100 ° C during the dyeing, a high temperature and high pressure dyeing machine is used.

When the same aramid fibers will be dyed, if the dyeing temperature is less than 80 ° C, a sufficient depth of color can not be obtained, on the other hand, if the dyeing temperature is higher than 150 ° C, requires a device with specific characteristics compared to the high-temperature and high-pressure dyeing machines generally used, and the energy cost is high.

On the other hand, the dyeing time after the temperature increase can be optionally selected depending on the dyeing time, and the relationship between the dyeing temperature and the dyeing device and, for example, at a dyeing temperature of 135. ° C using a dispersed tincture, is preferably within the range of 10 minutes to 90 minutes. In addition, the proportion of the dye in the bath is not particularly limited, for example it may be within the range of 1: 5 to 1: 100, etc. After dyeing, washing by the ordinary method on the aramid fibers can be carried out. In addition, the washing with reduction can be carried out in the same manner as in the dyeing step using a conventional disperse dyeing.

In this third embodiment, dyeing operation mentioned below is carried out subsequently on the aramid fibers in which the aforementioned pre-dyeing step was carried out.

A. Stage of provision of tincture For the stage of provision of dyeing in this third embodiment, the same operations are carried out as for the stage of dyeing provision in the first modality mentioned above or in the second one. modality mentioned above.

B. Stage of treatment with solvents The treatment step with solvents in this third embodiment is carried out by the same operations as those of the solvent treatment stage in the first modality mentioned above or in the second modality mentioned above.

C. Heat treatment stage In this third embodiment, the heat treatment step can be carried out, if necessary. By the way, when the heat treatment step is carried out in the third embodiment, the same operations are carried out as those in the heat treatment step in the second embodiment mentioned above.

In this third embodiment, as mentioned above, by carrying out a series of the dyeing operation 1 or the dyeing operation 3 after carrying out the pre-dyeing step, a dyed product of the aramid fibers can be obtained which have an appropriate color depth, and good color retention, in particular good color retention in light.

Additionally, in this third embodiment, by carrying out the pre-dyeing step mentioned above, the following results can be obtained. First, by carrying out the pre-dyeing stage using, for example, a disperse dye, a cationic dye or an acid dye, on the same aramid fibers, the lint on the surfaces of the aramid fibers themselves are dyed more adequately, so that the quality is also improved of dyeing and depth of color. On the other hand, when the aramid fibers are mixed with the other chemical fibers or natural fibers to form a mixed fiber, by carrying out the pre-dyeing step using a dye capable of dyeing these other fibers, the tone can be unified of the aramid fibers and that of the other fibers, which also improves the dyeing quality and the color depth of the dyed product. (4) Fourth modality The dyeing method according to this fourth embodiment has a post-dyeing step that dyes the aramid fibers with another dye different from the tin dye or the sulfur dye after the dyeing operation 1 or the dyeing operation. explained in the first modality mentioned above or the second modality mentioned above. Incidentally, the dyeing operation 1 or the aforementioned dyeing operation 3 carried out before the post-dyeing step can be carried out once alone, they can be repeated a plural number of times, depending on the need. By repeating the dyeing operation 1 or the dyeing operation 3 a plural number of times, aramid fibers with a denser color can be obtained.

A. Stage of provision of tincture In the stage of provision of dyeing in this fourth embodiment the same operations are carried out as those of the dyeing provision stage in the first modality mentioned above or the second modality mentioned above.

B. Stage of treatment with solvents The treatment step with solvents in this fourth embodiment is carried out by the same operations as those of the solvent treatment stage in the aforementioned first mode or the second modality mentioned above.

C. Heat treatment stage In this fourth embodiment, the heat treatment step can be carried out, if necessary. By the way, when the heat treatment stage is carried out in the. fourth embodiment, the same operations are carried out as those of the heat treatment stage in the second modality mentioned above.

D2. Stage of post-dyeing The post-dyeing step in this fourth embodiment is carried out by the same operations as those of the pre-dyeing stage explained in the third embodiment mentioned above. Nevertheless, the aramid fibers that will be dyed in the post-dyeing step have already been dyed by the tub dye or the sulfur dye in the dyeing operation 1 mentioned above or the dyeing operation 3 mentioned above, which is different from the pre-dyed step of the third embodiment mentioned above.

In this fourth embodiment, as mentioned above, by performing the post-dyeing step after carrying out a series of the dyeing operation 1 or the dyeing operation 3, a dyed product of the aramid fibers having a an appropriate color depth, and good color retention, in particular, good color retention in light.

Additionally, in this fourth embodiment, by carrying out the post-dyeing step mentioned above, the following results can be obtained. First, by carrying out the post-dyeing step using, for example, a dispersed dye, a cationic dye or an acid dye, on the aramid fibers themselves, the lint on the surfaces of the aramid fibers themselves is dyed most suitable way, so that the dyeing quality and the color depth are also improved. On the other hand, when the aramid fibers are mixed with the other chemical fibers or natural fibers to form a mixed fiber, by carrying out the post-dyeing step using a dye capable of dyeing these other fibers, the tone of the fibers can be unified. Aramid fibers and that of the other fibers, which also improves the dyeing quality and the color depth of the dyed product.

EXAMPLES In the following, based on the first modality to the fourth embodiment, with respect to aramid fibers of the para type, copolymerized aramid fibers of the para type and aramid fibers of the meta type, the dyeing of the amines was carried out. following respective Examples and Comparative Examples.

EXAMPLE 1 In this Example 1, N-methyl-2-pyrrolidone was used as the polar solvent, the fabrics (hereinafter referred to as the "aramid fabrics") comprising the aramid fibers were dyed based on the second embodiment mentioned above. In this Example 1, the cross fabrics (in advance referred to as the "aramid fabrics of the para type") with an area weight of 244 g / m 2 and using No. 20 count yarns of two folds comprising 100% weight of aramid fibers of type for as warp yarns and weft yarns, cross woven fabrics (hereinafter referred to as "copolymerized aramid fabrics of the para type") with an area weight of 244 g / m2 and using yarn counting No 20 of two folds comprising 100% by weight of copolymerized aramid fibers of the type for as warp yarns and weft yarns, and cross woven fabrics (hereinafter referred to as "aramid fabrics of the meta type") with an area weight of 200 g / m2 and using No. 40 coil yarns of two folds that comprise 100% by weight of aramid fibers of meta type as warp threads and weft threads were used. These aramid fabrics were used after desizing and scouring by the ordinary method.

A. Stage of provision of tincture The dyeing provisioning procedure was carried out by a continuous method using a squeezing device for testing, and each of the aramid fabrics was subjected to impregnation of a dyeing solution containing a tub dye to provide the tub dye on each one of them. This time each of the recovery rates were 61% by weight for the aramid fabrics of the for type, 58% by weight for the copolymerized aramid fibers of the para type, and 61% by weight for the aramid fibers of the meta type. .

As the dyeing solution, 50 g / L of a tub dye was dispersed in an unreduced state, and TAMANORI SA-25 (Arakawa Chemical Industries, Ltd, hereinafter referred to as "TAMANORI") was used in combination as agent preventive of migration. The dyeing was Mikethren Azul BC super-fine (C.l. Azul de Tina 6, the tincture of tub available from DyStar Japan Ltd.).

The drying was carried out by using a baking compartment device for the test, and after providing the dyeing solution each of the aramid fibers was dried at 105 ° C. for 5 minutes, to adhere the tub dye onto the fiber surfaces of each of the aramid fabrics. After drying each of the aramid fabrics was introduced in a subsequent solvent treatment step (treatment step with N-methyl-2-pyrrolidone) as such without carrying out washing or washing with reduction.

B. Stage of treatment with solvents (treatment stage with N-methyl-2-pyrrolidone) N-methyl-2-pyrrolidone was used as polar solvent, and the treatment was carried out by an aqueous solution with a concentration of 60% by weight. To provide the treatment solution, a squeezing device was used for testing, and after the dyeing stage each of the aramid tissues was subjected to a solvent treatment by a continuous method. The treatment temperature this time was 20 ° C. The treatment was carried out by immersing the aramid tissues in the treatment solution for 1 second and immediately afterwards they were squeezed by the juicer. This time each of the recovery rates was 59% by weight for aramid fabrics of type A, 59% by weight for copolymerized aramid fabrics of the para type, and 62% by weight for the aramid tissues of type goal.

C. Heat treatment stage For the heat treatment, a baking compartment device was used, and after the solvent treatment each of the aramid fabrics was carried out a dry heat treatment at 105 ° C for 5 minutes to adhere the tin dye on each of the aramid tissues. After the heat treatment each of the aramid tissues was dried after extracting the remaining N-methyl-2-pyrrolidone by washing with water and washing with hot water.

Then, after the heat treatment step, the washing with reduction of each of the dyed aramid fabrics was carried out. The wash with reduction was performed to extract the non-applied tub dye remaining on the surface of the fibers and to improve color retention. The conditions of the wash with reduction were the same as those of the dyeing of the polyester fibers by means of a dispersed dyeing, and the treatment was carried out by using 1 g / L of sodium dithionate as a reducing agent in combination with 1 g / L of sodium hydroxide at 80 ° C for 1 minute, then washing with hot water and washing with water was carried out and then the tissues were dried to obtain each of the aramid fabrics of Example 1 dyed navy blue and with an appropriate color depth.

COMPARATIVE EXAMPLE 1 In a manner similar to the aforementioned Example 1, a material in which only the step of treatment with dyeing of each of the aramid fabrics was carried out, and in which the stage of treatment with solvents and solvents was not carried out, was carried out. the heat treatment step, configured Comparative Example 1. More specifically, the dyeing process was carried out under the same conditions as those of Example 1 mentioned above, and after providing the tub dye the washing was carried out with reduction of each of the aramid tissues. The washing with reduction was carried out under the same conditions as those of Example 1 mentioned above, then washing with water was carried out with hot water and washing with water and then the tissues were dried to obtain each of the tissues of Example Comparative 1 Each of the aramid fabrics dyed of Example 1 and the Comparative Example 1 that have been dyed as mentioned above was evaluated as mentioned below.

Depth of color (total K / S value): A surface color depth of each of the stained aramid fabrics was shown as a total value of K / S. When the total K / S value is higher, it means that aramid fabrics are dyed by a dense color. The total K / S means a total value of 16 values from K / S to 16 wavelengths measured at 20 nm intervals in the measured range of wavelengths from 400 nm to 700 nm. The K / S value can be obtained from a reflectance R at the respective wavelengths from the Kubelka-Munk equation mentioned below. Here, K represents an extinction coefficient, and S represents a light scattering coefficient.

K / S = (1-R) 2 / 2R Incidentally, the value of the reflectance R was measured at the respective wavelengths by the use of a UV-3100 spectrophotometer (manufactured by Shimadzu Corporation) on which an integration sphere was mounted. With respect to each of the aramid fabrics, in Table 1 the total K / S values obtained by calculating according to the previous formula were shown.

Luminosity (Value of L *) The degree of dense color of each of the aramid fabrics was evaluated by the brightness (value of L *) in the colorimetric system of L * a * b mentioned above. The value of L * is shown in the range of 100 (white) to 0 (black), and the value of L * is smaller, then, it is evaluated as a denser color. By the way, the L * value was measured by using a CR-200 color difference meter (manufactured by Minolta Camera Co., Ltd.). The values of L * obtained for each of the aramid tissues are shown in Table 1.

Color retention: In addition to the color depth (total K / S value) and luminosity (L * value) mentioned above, the color retention was confirmed as a basic evaluation information of the dyed product. In particular, the retention of color to light (JIS L0842) was evaluated, which is assumed to be a problem in color retention of aramid fibers. The retention of color in light of the aramid fibers is difficult to evaluate because the fibers themselves become yellowish brown in addition to the discoloration of the dye due to the photoirradiation, so that it was evaluated as mentioned below. The fourth degree irradiation on the blue scale was applied to each of the aramid tissues, and the change was determined by the degree of gray scale by discoloration. By the way, the determination of the grade was, in addition to the five grades from the first grade (failure) to the fifth grade (good), the intermediate evaluation of the respective grades was also carried out. For example, an evaluation between the third grade and the fourth grade was mentioned as grades 3-4. The results of the evaluation were shown in table 1.

TABLE 1 As can be seen from Table 1, in Example 1, any of the respective aramid fabrics had the appropriate color depth (total K / S value) and brightness (value of L *), and each also had good color retention in light. Additionally, although not shown in Table 1, in each of the dyed aramid fabrics of Example 1, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable way. On the other hand, in Comparative Example 1, in comparison with those of Example 1, in any of the respective aramid fabrics, the depth of color, luminosity and color retention to light were lower, in particular, the depth of color, luminosity and retention of color in the light of the aramid tissues of the meta type.

EXAMPLE 2 In this Example 2, the aramid fabrics were dyed based on the second embodiment mentioned above and N-methyl-2-pyrrolidone was used as the polar solvent. In this Example 2, the cross-woven fabrics (hereinafter referred to as the "aramid fabrics mixed by spinning" with an area weight of 160 g / m2 and using No. 40 count yarns of two folds into which it had been mixed by yarn 95% by weight of aramid fibers of meta type and 5% by weight of copolymerized aramid fibers of type for as warp yarns and weft yarns were used.These aramid fabrics mixed by spinning were used after desizing and scouring by the ordinary method.

A. Stage of provision of tincture The same operations as in Example 1 mentioned above were carried out except for the dye change to be used for the sulfur dye mentioned below in Example 1 mentioned above. The recovery rate this time was 80% by weight. As the dyeing solution, 50 g / L of the sulfur dye was dispersed in a non-reduced state, and TAMANORI was used in combination as a migration preventive agent. The sulfur dye used was Asathio Azul RC200 (C.l. Azufre Blue 7, sulfur tincture available from Asahi Kagaku Kogyo Co., Ltd.).

Drying was carried out in the same manner as in Example 1 mentioned above, and the aramid fabrics mixed by spinning after supplying the coloring solution thereon were dried at 105 ° C for 5 minutes to adhere the sulfur dye on the surfaces of the fibers of aramid fabrics mixed by spinning. After drying the aramid fabrics mixed by spinning were injected in the subsequent solvent treatment step (treatment step with N-methyl-2-pyrrolidone) as such without carrying out washing or washing with reduction.

B. Stage of treatment with solvents (stage of treatment with N-methyl-2-pyrrolidone) In this Example 2, N-methyl-2-pyrrolidone which is the same as in Example 1 mentioned above was used as the polar solvent, but the treatment was carried out at a concentration of 100% by weight. For the provision of the treatment solution, a squeezing device was used for testing, and after the dyeing stage the aramid fabrics mixed by spinning were subjected to the solvent treatment by a continuous method. The treatment temperature this time was 50 ° C.

The treatment was carried out by immersing the aramid fabrics mixed by spinning in the treatment solution for 1 second and immediately after they were squeezed by the er. The recovery rate this time was 88% by weight.

C. Heat treatment stage The heat treatment was performed in the same manner as in Example 1 mentioned above, and through the use of a baking compartment device, after the treatment with solvents, the dry heat treatment of the aramid fabrics mixed at 105 ° C was carried out for 5 minutes to adhere the sulfur dye onto the fabrics of aramid mixed by spinning. After the heat treatment the aramid fabrics mixed by spinning were dried after extracting the remaining N-methyl-2-pyrrolidone by washing with hot water and washing with water, to obtain the aramid fabrics mixed by spinning of Example 2 dyed Navy blue and with an appropriate depth of color.

COMPARATIVE EXAMPLE 2 In a manner similar to the aforementioned Example 2, a material in which only the step of treatment with dyeing of each of the aramid fabrics was carried out, and in which the stage of treatment with solvents and was not carried out was carried out. the heat treatment step, configured Comparative Example 2. More specifically, the aramid fabrics mixed by spinning in which the dyeing step has been carried out under the same conditions as those of Example 2 mentioned above to provide the sulfur tincture were subjected to a wash with hot water and washed with water, and dried to obtain the aramid fabrics mixed by spinning of Comparative Example 2 which were dyed navy blue.

The aramid fabrics mixed by spinning of Example 2 and Comparative Example 2 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 2 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 2 As can be seen from Table 2, in Example 2, aramid fabrics mixed by spinning with a color depth (total K / S value) and an appropriate luminosity (value of L *) could be obtained. In addition, the aramid fabrics mixed by spinning of Example 2 have good color retention in light. Additionally, although it is not shown in Table 2, in the aramid fabrics mixed by spinning of Example 2, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in properties physical in a remarkable way. On the other hand, in Comparative Example 2, compared to those of Example 2, both color depth and brightness were markedly lower, and color retention to light was also low so that a dyed product was not obtained appropriate.

EXAMPLE 3 In this Example 3, the aramid fabrics were dyed with base in the second embodiment mentioned above and N-methyl-2-pyrrolidone was used as the polar solvent. In this Example 3, for each of the dyed aramid fabrics that were obtained in the aforementioned Example 1, the same dyeing operations as those of Example 1 mentioned above were repeated a plural number of times. More specifically, in the aforementioned Example 1 the dyeing operation was performed once, and in the dyeing operation in which the dyeing stage, the solvent treatment stage and the heat treatment stage were combined. it was also repeated to make a total of 3 times, a total of 5 times and a total of 7 times of the dyeing operations. However, washing with reduction was carried out after the final dyeing operation alone.

Each of the aramid fabrics dyed of Example 3 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 3 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 3 As can be seen from Table 3, in each of the aramid fabrics, compared to Example 1 in which the dyeing operation is once, in Example 3, as the number of dyeing operations increases, the color depth (total K / S value) is markedly improved, and brightness (value of L *) becomes so small as substantially around 30 or less, and each of the aramid fabrics can be obtained with a very dark color. Each of these aramid fabrics with a very dark color has had a good retention of color to light as shown in table 3. Additionally, although not shown in Table 3, in each of the dyed aramid fabrics of Example 3, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease of physical properties in a remarkable way.

EXAMPLE 4 In this Example 4, aramid fabrics were dyed based on the second embodiment mentioned above and N-methyl-2-pyrrolidone was used as the polar solvent. In this Example 4, on each of the aramid fabrics that are similar to those of Example 1 mentioned above, the dyeing operations of the tub dye were repeated a plural number of times in the same manner as in the aforementioned Example 3 . However, the tub dye used was Indanthren Rosa Brillante R (C.l. Red de Tina 1, tub dye available from DyStar Japan Ltd.). More specifically, in the aforementioned Example 1 the dyeing operation was performed once, and the dyeing operation in which the dyeing stage was combined, the The solvent treatment stage and the heat treatment step were also repeated a total of 2 times and a total of 3 times of the dyeing operations. However, the wash with reduction was carried out after the final dyeing operation alone.

Each of the dyed aramid fabrics of Example 4 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 4 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 4 As can be seen from Table 4, in each of the aramid fabrics, as compared to the case where the dyeing operation is once, as the number of dyeing operations increases, the Color depth (total K / S value) is remarkably improved, and each of the aramid fabrics can be obtained with a dark color. Considering that the luminosity (value of L *) is greater than 38, this is because the dye used is "Rosa R". This Example 4 is a prescription for dyeing an intense red, which is not a prescription for obtaining a dark color such as navy blue and black. On the other hand, each of the aramid fabrics has good light color retention as shown in Table 4. Additionally, although not shown in Table 4, in each of the dyed aramid fabrics of Example 4, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease of physical properties in a remarkable manner.

EXAMPLE 5 In this Example 5, the aramid fabrics were dyed according to the fourth embodiment mentioned above (dyeing by a tub dye followed by a post-dyeing by a dispersed dye) and N-methyl-2-pyrrolidone was used as the polar solvent . In this Example 5, on each of the aramid fabrics dyed by the tub dye that were obtained in the aforementioned Example 1, a post-dyeing step using a disperse dye was subsequently carried out.

D2. Stage of post-dyeing by a dispersed tincture The dyeing was carried out by the dyeing method using a disperse dyeing, and after dyeing by dyeing the tub each of the fabrics obtained in the aforementioned Example 1 was dyed by using a MINI dyeing tester. -COLOR at high temperature and high pressure (manufactured by TEXAM Giken Co., Ltd.) without washing with reduction. As the dyeing solution, 5% by weight of Dianix Blue FBL-E fabric (Disperse Blue IC 56, dispersed dye available from DyStar Japan Ltd.) was used, and a serial acetic acid / acetate buffer was used in combination. sodium with a pH of 5.

As a dyeing method, high temperature and high pressure dyeing was carried out by making a bath ratio of 1: 100, and under conditions at 135 ° C for 60 minutes. After dyeing the washing with reduction was carried out on each of the aramid fabrics in the same manner as in the dyeing of the ordinary polyester fibers by a dispersed dyeing. The washing with reduction was carried out under the conditions of using 1 g / L of sodium dithionate as a reducing agent in combination with 1 g / L of sodium hydroxide at 80 ° C for 1 minute, then, washing with hot water and washing with water was carried out and then the tissues were dried to obtain each of the aramid fabrics of Example 5 dyed navy blue which is a very dark color.

COMPARATIVE EXAMPLE 3 In a manner similar to Example 5 mentioned above, a material in which each of the aramid fabrics in which the dyeing was carried out by the dispersed dye alone configured Comparative Example 3. More specifically, none of the operations of dyeing comprising the dyeing provision stage, the solvent treatment step or the heat treatment step according to the present invention was carried out, but the dyeing step was performed with a single scattered dye which is the same as the one of Example 5 mentioned above, then, washing with reduction, washing with hot water and washing with water was carried out in the same manner as in Example 5, and the tissues were dried to obtain each of the tissues of aramid of Comparative Example 3 dyed navy blue.

COMPARATIVE EXAMPLE 4 In addition, similarly to the aforementioned Example 5, a material in which on each of the aramid fabrics the solvent treatment step had been carried out, the stage of treatment with heat and the stage of dyeing by means of a single dispersed tincture set up Comparative Example 4. More specifically, only the solvent treatment step and the heat treatment step were performed without carrying out the dyeing provision stage which is to provide a tub dye, and then, the dyeing step was carried out with a disperse dyeing which is the same as in Example 5 mentioned above, then carried out performed the wash with reduction, washing with hot water and washing with water in the same manner as in Example 5, and the fabrics were dried to obtain each of the aramid fabrics of Comparative Example 4 dyed navy blue.

Each of the aramid fabrics dyed of Example 5, Comparative Example 3 and Comparative Example 4 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 5 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 5 As can be seen from Table 5, in comparison in the Example, any of the respective aramid fabrics had the appropriate color depth (total K / S value) and brightness (value of L *), and each also had good color retention in light. Each of the aramide fabrics with the very dark color has a better light color retention than that of Example 1 as shown in table 5. Furthermore, in each of the aramid fabrics of this Example 5, the Fluff on the surfaces of the fabrics have been dyed a very dark color by both the tincture of tub and the scattered tincture, and the surface quality of the fabrics has been further improved. Additionally, although not shown in Table 5, in each of the dyed aramid fabrics of Example 5, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional changes, or the decrease in physical properties in a remarkable way.

On the other hand, in Comparative Example 3, in comparison with those of Example 5, the color depth and luminosity were lower than them in any of the respective aramid fibers. In addition, these respective aramid fabrics were dyed only by the dispersed dye, and the color retention in the light was insufficient compared to that of Example 5 and Example 1. Furthermore, in Comparative Example 4, by the effect of the treatment with solvents, the depth of color and luminosity by scattered dyeing are better than those of Comparative Example 3. However, the respective aramid fabrics of Comparative Example 4 are lower than those of Example 5 in both the color depth and the brightness. In addition, these respective aramid fabrics of Comparative Example 4 were dyed only by the dispersed dye, and the color retention of light was insufficient in comparison with that of Example 5.

EXAMPLE 6 In this Example 6, aramid fabrics were dried based on the first embodiment mentioned above and using sulfuric acid as the polar solvent. In this Example 6, the same aramid fabrics mixed by spinning as those of Example 2 mentioned above were used. These aramid fabrics mixed by spinning were used after desizing and scouring by the ordinary method.

A. Stage of provision of tincture In this Example 6, the "Mikethren Blue Superfine BC" tub dye is the same as that used in Example 1 mentioned above, or the "Indanthren Brilliant Pink R" tin dye was used which is the same as that used in Example 4 mentioned above. The operations in the dyeing provision stage were carried out in the same manner as in the aforementioned Example 1. The recovery rate this time was 80% by weight.

Drying was carried out in the same manner as in the Example mentioned above, and after providing the dyeing solution the aramid fabrics mixed by spinning were dried at 105 ° C for 5 minutes to adhere the tin dye to the surfaces of the fibers of aramid fabrics mixed by spinning. After drying the aramid fabrics mixed by spinning were injected in the subsequent solvent treatment step (sulfuric acid treatment step) as such without carrying out the washing or washing with reduction.

B. Stage of treatment with solvents (treatment stage with sulfuric acid) The treatment with sulfuric acid was carried out by the continuous method, using a squeezing device for testing, and the sulfuric acid treatment was carried out on the aramid fabrics mixed by spinning after the dyeing stage. The The concentration of the aqueous sulfuric acid solution was 77% by weight, and the treatment with temperature was 20 ° C. After immersion, the tissues were squeezed by the juicer to achieve a recovery rate of 156% by weight, and immediately thereafter, washed with water and neutralized by an aqueous solution of sodium carbonate, and washed with water. The immersion time in the aqueous solution of sulfuric acid was 30 seconds. After the solvent treatment step, the aramid fabrics mixed by spinning were sufficiently washed with water and then dried.

Next, the washing with reduction was carried out on the aramid fabrics mixed by spinning after the treatment with sulfuric acid. The washing with reduction was carried out under the same conditions as those of Example 1 mentioned above, then washing with hot water and washing with water and drying to obtain the aramid fabrics mixed by spinning of Example 6 with an appropriate color depth.

COMPARATIVE EXAMPLE 5 In a manner similar to Example 6 mentioned above, only the dyeing provision stage was applied to the aramid fabrics mixed by spinning without carrying out the sulfuric acid treatment, which configured Comparative Example 5. More specifically, the washing with reduction was applied on the aramid fabrics mixed by spinning which had been subjected to the dyeing stage under the same conditions as those of Example 1 mentioned above to provide the tin dyeing. The washing with reduction was carried out under the same conditions as in the aforementioned Example 1, then washing with hot water and washing with water was carried out and then the fabrics were dried to obtain the aramid fabrics blended by spun yarn. Comparative Example 5 The aramid fabrics mixed by spinning of Example 6 and Comparative Example 5 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 6 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 6 As can be seen from Table 6, in Example 6, the aramid fabrics mixed by spinning with a color depth (total K / S value) and an appropriate luminosity (L * value) can be obtained by the use of Tin dye "Blue BC". On the other hand, in the "Rosa R" tub dye of Example 6, it is a prescription to dye an intense red in the same manner as in Example 4 mentioned above, so that the brightness (value of L *) does not It shows a small value. However, in "Rosa R" vat dyeing, aramid fabrics mixed by spinning with an appropriate color depth (total K / S value) can be obtained. In addition, each of the aramid fabrics mixed by spinning of Example 6 has good color retention in light. Additionally, although not shown in Table 6, in the aramid fabrics blended by spinning of Example 6, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable way. On the other hand, in Comparative Example 5, compared to Example 6, both the color depth and the color retention to light were lower, and an appropriate dyed product can not be obtained.

EXAMPLE 7 In this Example 7, the aramid fabrics were dyed based on the first embodiment mentioned above and sulfuric acid was used as the polar solvent. In this Example 7, among the aramid fabrics mixed by spinning obtained in Example 6 mentioned above, on the aramid fabrics mixed by yarn dyed by the "Mikethren Blue BC super-fine" tub dye was repeated a plural number of times the dyeing operation which is the same as that of Example 6 mentioned above. More specifically, in the aforementioned Example 6, the dyeing operation was performed once, and the dyeing operation in which the dyeing stage and the solvent treatment step were combined (sulfuric acid treatment step). it was also repeated to make a total of 3 times, a total of 5 times and a total of 7 times of the dyeing operations. However, the wash with reduction was carried out after the final dyeing operation alone.

The aramid fabrics mixed by spinning of Example 7 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 7 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 7 As can be seen from Table 7, compared to Example 6 in which the dyeing operation is once, in Example 7, as the number of dyeing operations increases, the color depth (K / S value) total) is markedly improved, and the brightness (value of L *) becomes as small as 25 or less, and aramid fabrics mixed by spinning with a very dark color can be obtained.

These aramid fabrics mixed by spinning with a very dark color have had a good color retention in light as shown in table 7. Additionally, although not shown in table 7, in aramid fabrics mixed by spinning the Example 7, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable manner.

EXAMPLE 8 In this Example 8, aramid fabrics were dyed based on the first embodiment mentioned above and sulfuric acid was used as the polar solvent. In this Example 8, the dyeing operation by sulfur dyeing was carried out on the same aramid fabrics mixed by spinning as in Example 6. After desizing and scouring by the ordinary method the aramid fabrics mixed by spinning were used in the same manner as in Example 6 mentioned above.

A. Stage of provision of tincture In this Example 8, similarly to the aforementioned Example, the same operations as in the aforementioned Example 6 were performed except for the dye change to be used for the sulfur dye mentioned below. The recovery rate this time was 80% by weight. As the dyeing solution, 50 g / L of the sulfur dye were dispersed in a non-reduced state, and in combination TAMANORI was used as a migration preventive agent. Sulfur dyes used were Asathiosol Yellow S-RR (CI No. unknown, sulfur dye available from Asahi Kagaku Kogyo Co., Ltd.), Asathiosol Bordeaux S-3B (Sulfur Red CI 6, available sulfur tincture from Asahi Kagaku Kogyo Co., Ltd.), Asathiosol Blue RC200 (Cl Blue Sulfur 7, sulfur dye available from Asahi Kagaku Kogyo Co., Ltd.), and Asathiosol Indigo Green S-BG (C. 1 Sulfur Blue 15, sulfur tincture available from Asahi Kagaku Kogyo Co., Ltd.).

Drying was carried out in the same manner as in Example 6 mentioned above, and the aramid fabrics mixed by spinning after providing the dyeing solution thereon were dried at 105 ° C for 5 minutes to adhere the sulfur dye. on the surfaces of the fibers of aramid fabrics mixed by spinning. After drying the aramid fabrics mixed by spinning were injected in the subsequent solvent treatment step (sulfuric acid treatment step) as such without carrying out the washing or washing with reduction.

B. Stage of treatment with solvents (treatment stage with sulfuric acid) In this Example 8, sulfuric acid treatment was applied on the aramid fabrics mixed by spinning after the dyeing step in the same manner as in Example 6 mentioned above. The concentration of the aqueous sulfuric acid solution was 77% by weight, the treatment temperature was 20 ° C and the immersion time was 30 seconds. The rate of recovery this time was 156% by weight, and water washing, neutralization and washing with water were carried out in the same manner as in Example 6 mentioned above, and the fabrics were dried to obtain the aramid fabrics mixed by spinning the Example 8 with an appropriate color depth.

COMPARATIVE EXAMPLE 6 In a manner similar to the aforementioned Example 8, only the dyeing step was applied on the aramid fabrics mixed by spinning without carrying out the sulfuric acid treatment which configured the Comparative Example 6. More specifically, the aramid fabrics mixed by spinning by applying the dyeing step under the same conditions as those of Example 8 mentioned above to provide the sulfur dye were washed with water and dried to obtain the aramid fabrics mixed by spinning of Comparative Example 6 .

The aramid fabrics mixed by spinning of Example 8 and Comparative Example 6 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. However, the luminosity (value of L *) was not measured. The results of the evaluation of the total K / S value which evaluates the depth of color and the retention of color to light are shown in table 8.

TABLE 8 As can be seen from Table 8, in Example 8, mixed aramid fabrics can be obtained by spinning with an appropriate color depth (total K / S value). In addition, each of the aramid fabrics mixed by spinning of Example 8 has good color retention in light. Additionally, although not shown in Table 8, in the aramid fabrics mixed by spinning of Example 8, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable way. On the other hand, in Comparative Example 6, compared to those of Example 8, both the color depth and the color retention to light are lower, and an appropriate dyed product can not be obtained.

EXAMPLE 9 In this Example 9, the aramid fabrics were dyed based on the first embodiment mentioned above and sulfuric acid was used as the polar solvent. In this Example 9, the aramid fibers mainly comprise the cross-woven fabrics of aramid fibers of the para type (hereinafter referred to as the "aramid fabrics of a single yarn of the para type") with an area weight of 144 g / m2 and using single yarn No. 20 counting yarns comprising 100% by weight aramid fibers of the type for as warp yarns and weft yarns were used. The single-spun aramid fabrics were used for after desizing and degummed by the ordinary method.

In this Example 9, the dye provision stage and the solvent treatment step (sulfuric acid treatment step) were carried out under the same operating conditions and the same dyes used in the aforementioned example 6. This time the recovery rate in the tincture provision stage was 61% by weight, and the recovery rate in the solvent treatment stage was 126% by weight. After performing the dyeing operation by tub dyeing according to the above, washing with reduction was carried out in the same manner as in Example 1 mentioned above to obtain the single-spun aramid fabrics of type for of Example 9 with an appropriate color depth.

COMPARATIVE EXAMPLE 7 In a similar manner to the aforementioned Example 9, only the dyeing provision stage was applied on the single-spun aramide fabrics for without carrying out the sulfuric acid treatment, which configured the Comparative Example 7. More specifically , the wash with reduction was applied under the same conditions as in Example 1 on single spun aramid fabrics of the type for the dyeing step with the same conditions as in the aforementioned Example 9 to provide the tincture of tub. Then, washing with hot water and washing with water were carried out and the fabrics were dried to obtain the single-spun aramid fabrics of type for Comparative Example 7.

The single-spun aramid fabrics of type for Example 9 and Comparative Example 7 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. However, the luminosity (value of L *) was not measured. The results of the evaluation of the total K / S value which evaluates the depth of color and the retention of color to light are shown in table 9.

As can be seen from Table 9, in Example 9, single-spun aramid fabrics of type can be obtained with an appropriate color depth (total K / S value). In addition, each of the single-spun aramid fabrics of type for from Example 9 has good color retention in light. Additionally, although not shown in Table 9, in the single-spun aramid fabrics of type for Example 9, the fabrics had maintained the proper properties of the high performance fibers without generating color inconsistency or dimensional change, or the decrease of physical properties in a remarkable way. On the other hand, in Comparative Example 7, compared to Example 9, both the color depth and the color retention to light are lower, and an appropriate dyed product can not be obtained.

EXAMPLE 10 In this Example 10, the aramid tissues were dyed with base in the first embodiment mentioned above and sulfuric acid was used as the polar solvent. In this Example 10, between the single-spun aramid fabrics of the type for obtained in Example 9 mentioned above, the same dyeing operation which is the same as in the aforementioned Example 9 was repeated on the aramid fabrics of a single type yarn for dyeing by the tub dye "Mikethren Azul BC super-fine" a plural number of times. More specifically, in the aforementioned Example 9 the dyeing operation was performed once, and the dyeing operation in which the dyeing stage and the solvent treatment stage (sulfuric acid treatment step) were combined was also carried out. repeated to perform a total of 3 times, a total of 5 times and a total of 7 times of the dyeing operations. However, the wash with reduction was carried out after the final dyeing operation alone.

Aramid fabrics of a single yarn of type for dyeing Example 10 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. However, the luminosity (value of L *) was not measured. The results of the evaluation of the total K / S value which evaluates the depth of color and the retention of color to light are shown in Table 10.

TABLE 10 «Single yarn aramid fabrics of the type for > > x "Tint of size" x < < Sulfuric acid » As can be seen from Table 10, in comparison with Example 9 in which the dyeing operation is once, in Example 10, as the number of dyeing operations increases, the color depth is significantly improved (value of K / S total), and the aramid fabrics can be obtained with a very dark color. These single-spun aramid fabrics of a very dark color type have had good light color retention as shown in Table 10. Additionally, although not shown in Table 10, in the aramid tissues of a single yarn of type for from Example 10, the fabrics had maintained, the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease of physical properties in a remarkable manner.

EXAMPLE 11 In this Example 1 1, the aramid tissues were stained with base in the fourth embodiment mentioned above and sulfuric acid was used as the polar solvent. In this Example 11, the same aramid fabrics mixed by spinning as used in Example 6 mentioned above were used. Aramid fabrics mixed by spinning were used after desizing and scouring by the ordinary method.

A. Stage of provision of tincture In this Example 1 1, the same operations as in the aforementioned Example 1 were carried out except for the use of 60 g / L of Mikethren Gris M super-fine (Cl Negro de Tina 8, tincture of tub available from DyStar Japan Ltd.) as the tub tincture. The recovery rate this time was 80% by weight.

Drying was carried out in the same manner as in the Example mentioned above, and after providing the dyeing solution the aramid fabrics mixed by spinning were dried at 105 ° C for 5 minutes to adhere the tin dye to the surfaces of the fibers of aramid fabrics mixed by spinning. After drying the aramid fabrics mixed by spinning were injected in the subsequent solvent treatment step (sulfuric acid treatment step) as such without carrying out the washing or washing with reduction.

B. Stage of treatment with solvents (treatment stage with sulfuric acid) The treatment with sulfuric acid was carried out by the continuous method, using a squeezing device for testing, and the sulfuric acid treatment was carried out on the aramid fabrics mixed by spinning after the dyeing stage. The concentration of the aqueous solution of sulfuric acid was 80% by weight, and the treatment with temperature was 20 ° C. After immersion, the tissues were squeezed by the juicer to achieve a recovery rate of 80% by weight, and immediately thereafter, washed with water and neutralized by an aqueous solution of sodium carbonate, and washed with water. The immersion time in the aqueous solution of sulfuric acid was 20 seconds. In this Example 11, after the solvent treatment step (sulfuric acid treatment step) the aramid fabrics mixed by spinning were injected in the subsequent post-dyeing step by a dispersed dye without drying.

D2. Stage of post-dyeing by a dispersed tincture The dyeing was carried out by the dyeing method using a disperse dyeing, and after the treatment with sulfuric acid the aramid fabrics mixed by spinning were dyed by using a MINI-COIOR dyeing tester of high temperature and high pressure ( manufactured by TEXAM Giken Co., Ltd.) without drying as mentioned previously. With the dyeing solution, 10% by weight of Kayalon NB-E Navy Blue Polyester fabric (Cl No. unknown, dispersed dye available from NIPPON KAYAKU Co., Ltd.) was used and a series buffer was used in combination. Acetic acid / sodium acetate with a pH of 5.

As a dyeing method, high temperature and high pressure dyeing was carried out by making a bath ratio of 1: 100, and under conditions at 130 ° C for 60 minutes. After dyeing the wash with reduction was applied on the aramid fabrics mixed by spinning in the same manner as in the dyeing of the ordinary polyester fibers by a dispersed dyeing. The washing with reduction was carried out under the same conditions of the post-dyeing step of Example 5 mentioned above, then washing with hot water and washing with water were carried out and then the fabrics were dried to obtain aramid fabrics mixed by spinning of Example 11 dyed black which is a very dark color.

COMPARATIVE EXAMPLE 8 In a manner similar to the aforementioned Example 11, a material in which the dyeing step by the dispersed dye alone was applied onto the non-dyed yarn-mixed aramid fabrics configured Comparative Example 8. In this Comparative Example 8, the conditions of the stage of dyeing by the dispersed tincture were the same as those of Example 1 1 mentioned above.

COMPARATIVE EXAMPLE 9 In a manner similar to the aforementioned Example 1 1, the solvent treatment stage (sulfuric acid treatment step) and the dyeing step by the dispersed dye alone were carried out, which configured Comparative Example 9. That is, Comparative Example 9 provides a material in which the aramid fabrics mixed by spinning subjected to the sulfuric acid treatment were dyed by the dispersed dye alone. In this Comparative Example 9, the conditions of the sulfuric acid treatment and the dyeing by the dispersed dye were the same as those of Example 1 mentioned above.

The aramid fabrics mixed by spinning of Example 1 1, Comparative Example 8 and Comparative Example 9 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. However, the luminosity (value of L *) was not measured. The results of the evaluation of the total KJS value which evaluates the depth of color and the retention of color to light are shown in Table 1 1.

TABLE 11 As can be seen from Table 11, in Example 11, substantially improved yarn-mixed aramid fabrics can be obtained in color depth (total K / S value) and with a very dark color. In addition, the aramid fabrics mixed by spinning of Example 11 have good color retention in light. In addition, in the aramid fabrics mixed by spinning of this Example 11, the lint on the surfaces of the fabrics has been dyed by both, the tin dye and the dispersed dye, in a very dark color, and the surface quality of tissues. Additionally, although not shown in Table 11, in the aramid fabrics mixed by spinning of Example 11, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable way. On the other hand, in Comparative Example 8, compared to Example 8, the color depth is lower than that of the Example, and the color retention is noticeably lower for it so that an appropriate dyed product can not be obtained. .

Furthermore, in Comparative Example 9, considering that a sufficient depth of color can not be obtained, it is only dyed by the dispersed dye so that the color retention of the light is markedly less for the same, and a dyed product can not be obtained. appropriate.

EXAMPLE 12 In this Example 12, the aramid fabrics were dyed based on the first embodiment mentioned above and benzyl alcohol was used as the polar solvent. In this Example 12, the same aramid fabrics of type for were used as those used in Example 1 mentioned above. Aramid fabrics of the para type were used after desizing and scouring by the ordinary method.

A. Stage of provision of tincture In this Example 12, the following tub dyeing was provided by the same operations as in the aforementioned Example 1. The recovery rate this time was 58% by weight. As the dyeing solution, 50 g / L of the same "Mikethren Gray M super-fine" tub dye that in Example 11 mentioned above was dispersed in a non-reduced state, and 10 g / L of GERMADYE were used in combination AM-X (available from RAON CHEMICAL LTD.) As the preventive agent of migration.

The drying was carried out in the same steps of Example 1 mentioned above, and after providing the coloring solution the aramid fabrics of the para type were dried at 1 10 ° C for 2 minutes to adhere the tin dye to the surfaces of the fibers of the aramid tissues of type para. After drying the aramid fabrics mixed by spinning were injected in the subsequent stage of treatment with solvents (treatment step with benzyl alcohol) as such without carrying out the washing or washing with reduction.

B. Stage of treatment with solvents (stage of treatment with benzyl alcohol) In this Example 12, benzyl alcohol (99.5% product) was used as the polar solvent without dilution. To provide the treatment solution, a squeezing device was used for testing, and para-type aramid tissues were subjected to solvent treatment by a continuous method. The treatment temperature at this time was 20 ° C. The treatment was carried out by immersing the para-type aramid tissues in the treatment solution for 1 second, and immediately afterwards they were squeezed by the juicer. The recovery rate this time was 61% by weight. Incidentally, in this Example 12, without carrying out the heat treatment after the solvent treatment, the aramid fabrics of type for after the treatment step with solvents were washed with hot water and washed with water to extract the Remaining benzyl alcohol, and then, washing with reduction was carried out. The washing with reduction was carried out in the same manner as in Example 1 mentioned above. Then, washing with hot water and washing with water were carried out and the fabrics were dried to obtain the aramid fabrics of the type for Example 12 dyed black with an appropriate color depth.

Aramid fabrics of type for Example 12 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 12 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 12 As can be seen from Table 12, in Example 12, aramid fabrics of the para type have a color depth (total K / S value) and an appropriate luminosity (value of L *), and also have good retention of color to light. Additionally, considering that it is not shown in table 12, the aramid fabrics of type for dyeing the Example 12, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease of the physical properties in a remarkable manner.

EXAMPLE 13 In this Example 13, aramid fabrics were dyed based on the first embodiment mentioned above and benzyl alcohol was used as the polar solvent. In this Example 13, on the dyeing aramid fabrics that were obtained in Example 12 mentioned above, the same dyeing operation as in the aforementioned Example 12 was repeated a plural number of times. More specifically, in the aforementioned Example 12 the dyeing operation was performed once, and the dyeing operation in which the dyeing stage and the solvent treatment stage had been combined was also repeated to make a total of 2 times, a total of 3 times and a total of 4 times of the dyeing operations. However, the wash with reduction was carried out after the final dyeing operation alone.

Aramid fabrics of the type for Example 13 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. In table 13, they show the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and retention of color to light.

TABLE 13 As can be seen from Table 13, in aramid fabrics of type para, compared to Example 12 in which the dyeing operation is once, in Example 13, as the number of dyeing operations increases, the Color depth (total K / S value) is remarkably improved, the brightness (value of L *) becomes as small as 30 p less, so that aramid fabrics of type for a very dark color could be obtained. Aramid fabrics of a very dark color type have had good light color retention as shown in Table 13. Additionally, considering that it is not shown in Table 13, aramid fabrics of the type for dyeing Example 13, the fabrics had maintained the proper properties of high performance fibers without the generation of color inconsistency or dimensional change, or the decrease of physical properties in a remarkable manner.

EXAMPLE 14 In this Example 14, the aramid fabrics were dyed based on the second embodiment mentioned above and 4 types of polar solvents, triethylene glycol, formic acid, DL-lactic acid and oxalic acid were used as the polar solvent, respectively. In this Example 14, the same aramid tissues were used for that in Example 1 mentioned above. Aramid fabrics of the para type were used after desizing and scouring by the ordinary method.

A. Stage of provision of tincture In this Example 14, the same "Mikethren Gris M super-fine" vat dye was used as in Example 12 mentioned above, and the same operations as in the aforementioned Example 12 were used. The recovery rate this time was 58% by weight. The dyeing was carried out in the same manner as in Example 12 mentioned above. The aramid fabrics mixed by spinning after drying were injected in the subsequent stage of treatment with solvents as such without carrying out the washing or washing with reduction.

B. Stage of treatment with solvents In this Example 14, triethylene glycol (95% product), formic acid (98% product) and DL-lactic acid (85% product) were each one used without dilution. On the other side, the oxalic acid (dihydrate) was dissolved in water and used as a 10% by weight aqueous solution. To provide the treatment solution, a squeezing device was used for testing, and para-type aramid tissues were subjected to solvent treatment by a continuous method. The treatment temperature at this time was each 20 ° C. The treatment was carried out by immersing the aramid tissues of the para type in the treatment solution for 1 second and immediately afterwards they were squeezed by the juicer. The recovery rates of the respective polar solvents at this time were 75% by weight for triethylene glycol, 71% by weight for formic acid, 81% by weight for DL-lactic acid, and 75% by weight for aqueous solution of oxalic acid, respectively.

C. Heat treatment stage For the heat treatment, a baking compartment device was used for testing, and the dry heat treatment was applied on the aramid tissues of type for after the treatments with the respective solvents at 1 10 ° C for 2 minutes for Adhere the tub tincture on the aramid tissues of the para type. The aramid tissues of type for after the heat treatment were washed with hot water and were washed with water to extract the respective polar solvents, and were dried.

Then, the washing was carried out with reduction of the Aramid fabrics of the type for dyeing after the heat treatment step. The washing with reduction was carried out in the same manner as in Example 1 mentioned above. Then, washing with hot water and washing with water were carried out and the fabrics were dried to obtain the aramid fabrics of type for Example 14 dyed black with an appropriate color depth.

The aramid fabrics of type for Example 14 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 14 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 14 As can be seen from Table 14, in Example 14, aramid fabrics of the para type have a color depth (total K / S value) and a luminosity (value of L *) appropriate in any of the 4 types of polar solvents, and also have good color retention in light. Additionally, considering that it is not shown in Table 14, the dyed-type aramid fabrics of Example 14, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable way.

EXAMPLE 15 In this Example 15, the aramid fabrics were dyed based on the third embodiment mentioned above (pre-dyed by a disperse dye followed by a dyeing by a tub dye) and 5 types of polar solvents, benzyl alcohol, triethylene glycol, acid Formic, DL-lactic acid and oxalic acid were used as the polar solvent, respectively. In this Example 15, on the same aramid fabrics of type for as in the aforementioned Example 1, a pre-dyeing step by a disperse dyeing was carried out first. Next, on the aramid fabrics of type for after the pre-dyeing step, the dyeing operation was carried out using the same tub dye and the respective polar solvents as in Example 12 and Example 14 mentioned above .

D1. Stage of pre-dyeing by dispersed tincture Aramid fabrics of the non-dyed type were dyed by a disperse dyeing after desizing and scouring by the ordinary method. The dyeing was carried out by the dip dyeing method, and aramid fabrics were dyed by using a MINI-COLOR high temperature and high pressure dyeing tester (manufactured by TEXAM Giken Co., Ltd .). As the coloring solution, 2.5% by weight of Kayalon fabric Black Polyester ECX-300 (dispersed dyeing available from NIPPON KAYAKU Co., Ltd., CI No. unknown) and 2.5% by weight of Kayalon fabric Black Polyester TN-200 (Unknown CI, scattered dye available from NIPPON KAYAKU Co., Ltd.) were used in combination, and a standard acetic acid / sodium acetate buffer with a pH of 5 was used.

As the dyeing method, a high temperature and high pressure dyeing was performed using a bath ratio of 1: 20, and under the conditions at 135 ° C for 60 minutes. After the dyeing was applied, the wash with reduction was applied on aramid fabrics of the same type as in the dyeing of ordinary polyester fibers by means of a dispersed dyeing. The washing with reduction was carried out under the conditions of the use of 5 g / L of sodium dithionate as the reducing agent in combination with 5 g / L of sodium hydroxide at 80 ° C for 1 minute, and in this Example 15 , the wash with reduction was repeated twice. Afterwards, washing with hot water and washing with water were carried out and the tissues were dried to obtain aramid fabrics of the type for which they had been subjected to pre-dyeing by a dispersed dye.

Next, the dyeing operations each of which uses benzyl alcohol, triethylene glycol, formic acid, DL-lactic acid or oxalic acid as the polar solvent, and the wash with reduction were applied on the aramid tissues of type for the Same as in Example 12 mentioned above or Example 14 mentioned above to obtain the aramid fabrics of type for from Example 15 dyed black which is a very dark color.

Aramid fabrics of the type for Example 15 that had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 15 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 15 «Aramid fabrics of type for» x «Dispersed tincture + tub tincture» x «Various polar solvents » As can be seen from Table 15, compared to Example 12 mentioned above (see Table 12) or Example 14 mentioned above (see Table 14) which had been dyed only by the tub dye, in the Example 15 in which the pre-dyed by the scattered dye has been made, the dyeing densities (value of / S total) are markedly improved, and the brightness (value of L *) becomes as small as 30 or less, and Aramid fabrics of type A can be obtained with a very dark color in the respective samples. Aramid fabrics of the very dark color type have an extremely good light color retention as shown in table 15. Furthermore, in the aramid fabrics of type for example 15, the lint on the surfaces of The fabrics have been dyed a very dark color by both, the tin dye and the dispersed tincture, and the surface qualities of the fabrics have been improved. Additionally, considering that it is not shown in Table 15, the aramid fabrics of dyeing type of Example 15, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease in physical properties in a remarkable way.

EXAMPLE 16 In this Example 16, the aramid fabrics were dyed based on the third embodiment mentioned above (pre-dyed by cationic dyeing followed by a dyeing by tub dyeing) and DL-lactic acid was used as the polar solvent. In this Example 16, on the same aramid fibers of type for as in the aforementioned Example 1, a pre-staining step by a cationic dye was carried out first. Next, on the aramid fibers of type for after the pre-dyeing step, a dyeing operation by the same tub dye as in the aforementioned Example 14 and by DL-lactic acid was carried out.

D1. Stage of pre-staining using a cationic tincture Aramid fibers of the non-dyed type were dyed by cationic dyeing after desizing and scouring by the ordinary method. The dyeing was carried out by the dip dyeing method, and aramid fabrics were dyed by using a MINI-COLOR high temperature and high pressure dyeing tester (manufactured by TEXAM Giken Co., Ltd .). As the dyeing solution, 5.0% by weight of Kayacryl Marine fabric RP-ED (Cl No. unknown, cationic dye available from NIPPON KAYAKU Co., Ltd.) was used and 25 g / L of sodium nitrate and a carrier of tincture available commercially they were also used in combination, and a standard buffer of acetic acid / sodium acetate with a pH of 5 was used.

As the dyeing method, a high temperature and high pressure dyeing was performed using a bath ratio of 1: 20, and under conditions at 135 ° C for 60 minutes. Aramid fabrics of type for after dyeing were subjected to washing with hot water and washing with water, and were dried to obtain the aramid fabrics of the type for which they have been subjected to a pre-dyeing by means of a cationic dyeing.

Then, on aramid fabrics of type for which has been subjected to pre-dyeing, the stage of provision of dyeing was applied by using 50 g / L of the same tub dye "Mikethren Blue BC super-fine "as in Example 1 mentioned above according to the same operations as in Example 12 mentioned above. The recovery rate this time was 58% by weight. Additionally, on the aramid fabrics of type for after the dyeing provision stage, the treatment step with solvents using DL-lactic acid as the polar solvent, the heat treatment step and the washing with reduction were carried out in the same manner as in the aforementioned Example 14 to obtain the aramid fabrics of type for example 16 dyed navy blue which is a very dark color.

COMPARATIVE EXAMPLE 10 In a manner similar to the aforementioned Example 16, dyeing by a cationic dye alone was applied on the aramid fabrics of the para type, which configured Example 10. More specifically, none of the dyeing operations of the dyeing stage , the solvent treatment step and the heat treatment step according to the present invention was performed, but the step of dyeing by a cationic dye was carried out in the same manner as in Example 16 mentioned above, then, washing with reduction, washing with hot water and washing with water were applied to the tissues in the same manner as in Example 16, and the fabrics were dried to obtain aramid fabrics of the type for Comparative Example 10 dyed Navy blue.

The dyeing aramid fabrics of Example 16 and the Comparative Example 10 which had been dyed as mentioned above were evaluated in the same manner as in Example 1 mentioned above. Table 16 shows the results of the evaluation of the total K / S value that evaluates the depth of color, luminosity (value of L *) which evaluate the degree of dark color and color retention in light.

TABLE 16 As can be seen from Table 16, in Example 16 in which it has been dyed by cationic dyeing and vat dyeing, compared to Comparative Example 10 in which it has been dyed by cationic dyeing alone, it can be obtained aramid fabrics of type for a great depth of color (value of K / S value), and a luminosity (value of L *) as small as 30 or less, with a very dark color. On the other hand, considering that the color retention of Comparative Example 10 in which it has been dyed only by the cationic dye is remarkably weak, in Example 16 in which it has been dyed not only by the cationic dye but also by tin dyeing, a noticeable improvement in the retention of color to light can be recognized. In addition, in the aramid fabrics of the type for this example 16, the lint on the surfaces of the fabrics has been dyed a very dark color by both cationic tincture and tin dyeing, and the quality has been further improved superficial of the tissues. Additionally, considering that it is not shown in Table 16, the aramid fabrics of dyed type of Example 16, the fabrics had maintained the proper properties of the high performance fibers without the generation of color inconsistency or dimensional change, or the decrease of physical properties in a remarkable way.

As explained in the dyeing operations of Example 1 to Example 16 mentioned above, according to the present invention, it can be applied to any of the aramid fibers of the para type, the copolymerized aramid fibers of the para type and the aramid fibers. of the meta type, and these aramid fibers can be dyed of an appropriate color depth. Furthermore, according to the present invention, the color inconsistency or the dimensional change, or the reduction of physical properties is not generated significantly in the aramid fibers after dyeing. Additionally, a tub tincture or a sulfur tincture with good color retention, in particular, good color retention to light is used so that color retention becomes good, in particular the retention of color to light of the aramid fabrics dyed.

In addition, by changing the concentration used and the tone of the tub dye or the sulfur dye to be used, products dyed in various shades from a pale color to a dark color can be obtained. In particular, according to the present invention, the aramid fibers of the para type or the copolymerized aramid fibers of the para type can be dyed a very dark color (for example, the value of L * is 30 or less) such as black or navy blue which has been considered difficult until today.

Additionally, as a pre-stage or post-stage method for dyeing aramid fibers according to the present invention, when carrying out the pre-dyeing step or the post-dyeing step using another dye different from the tin dyeing and the sulfur dyeing, the lint on the surface of The aramid fibers themselves are sufficiently dyed, the dyeing quality becomes good, and also the color depth is improved. For e | On the other hand, when the aramid fibers constitute fibers mixed with the other chemical fibers or natural fibers, in carrying out these stages of dyeing, the tone of the aramid fibers and that of the other fibers can be unified, so that improves the dyeing quality and the color depth of the dyed product.

Therefore, according to the present invention, a method can be provided for dyeing dyed fibers and aramid fibers in which the color retention, in particular, the color retention in the light of the dyed product is good, the tone it is abundant and the product has an appropriate depth of color. This is effective for new applications of aramid fibers.

Incidentally, in order to practice the present invention, it is not limited by the respective Examples mentioned above, the following several modified examples may be mentioned. (1) In the respective Examples mentioned above, the solvent treatment step is carried out after the dyeing step, but the mode is not limited thereto, and the dyeing step can be carried out after the dyeing step. treatment stage with solvents. (2) In the respective Examples mentioned above, after providing the dye solution containing the tub dye or the sulfur dye over the aramid fabrics, said aramid fabrics are dried, but the mode is not limited thereto, and after providing the dye solution, the aramid fabrics can be injected in the solvent treatment step without drying. (3) In the respective examples mentioned above, considering that navy blue or black are used in many cases except for a part of the intense tones, these examples are merely to show that the fabrics can be dyed a dark color or a very dark color. Consequently, by changing the concentration used and the tone of the tub dye or the sulfur dye to be used, a product dyed from a pale color to a dark color with various shades including the intense tones can be obtained. (4) In the respective Examples mentioned above, the aramid fibers on which the tub dye or the sulfur dye was added in the dyeing step were injected in the subsequent stage of treatment with solvents without washing. However, the tub tincture or the sulfur tincture is adhered onto the aramid fibers with a certain degree of affinity after the tincture provision stage. Accordingly, the aramid fibers after the tincture provision stage can be injected in the solvent treatment step after of the washing. (5) In the respective Examples mentioned above, the washing with reduction is carried out after the dyeing operation in some cases, but the washing with reduction can be carried out only in the case where it is required, and a washing prescription with reduction is not limited only to an alkaline series, and washing with reduction can be done with prescription of reduction with acid series. (6) In Example 14 and Example 15 mentioned above, the DL-lactic acid in which optical isomers were mixed was used as the polar solvent, but the mode is not limited thereto, and D-lactic acid or L-lactic acid can be used. (7) In Example 5, Example 11 and Example 15 mentioned above, no dye carrier or deep coloration agent is used for dyeing by a disperse dyeing. In the present invention, pre-dyeing or post-dyeing is a merely auxiliary dyeing, and the dyeing carrier, etc., may not be used. However, by using various types of dye carriers, etc., used in combination during the ordinary dyeing of aramids, the fabrics can be dyed a darker color. (8) In the respective Examples mentioned above, the dyeing was applied on the aramid fabrics, but the mode is not limited thereto, and can be woven fabrics, non-woven fabrics, etc., or it can be spun, cotton, etc. .

Claims (9)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for dyeing aramid fibers comprising a step of providing dyeing in which a tub dye or a sulfur dye is provided on the aramid fibers, a stage of treatment with solvents in which the aramid fibers are treated by a treatment solution containing a polar solvent, and after the treatment step with solvents, a heat treatment step in which the aramid fibers are subjected to a heat treatment, if necessary, and which has at least one dyeing operation from among the following four dyeing operations, dyeing operation 1: dyeing step followed by a solvent treatment step, dyeing operation 2: solvent treatment step followed by a provisioning step dyeing, dyeing operation 3: tincture provision stage followed by a solvent treatment step followed by a heat treatment step, operac dyeing ion 4: treatment step with solvents followed by a heat treatment step followed by a dyeing step, once or more.

2 - . 2 - The method for dyeing aramid fibers according to claim 1, further characterized in that the polar solvent has a value of a solubility parameter (d) within the range of 18 to 32 (MPa) 2.

3. The method for dyeing aramid fibers according to claim 1, further characterized in that the polar solvent is at least one selected from the group consisting of N-methylpyrrolidone, N, N-dimethylformamide,?,? -dimethylacetamide, dimethylsulfoxide, alcohol benzyl, diethylene glycol, triethylene glycol, sulfuric acid, formic acid, lactic acid and oxalic acid.

4. - A method for dyeing aramid fibers comprising the method for dyeing aramid fibers of any of claims 1 to 3, and a pre-dyeing step which is carried out before the method for dyeing or a post-dyeing step. which is carried out after the same, characterized in that the aramid fibers are stained by a dyeing different from the tin dyeing and the sulfur dyeing in the pre-dyeing step or in the post-dyeing step.

5. - Aramid fibers that are dyed by the method for dyeing aramid fibers of any of claims 1 to 3.

6. - The aramid fibers dyed according to claim 5, further characterized in that the brightness (value of L *) in a colorimetric system L * a * b * thereof is 38 or less.

7. - The aramid fibers dyed according to claim 5, further characterized in that the brightness (value of L *) in a colorimetric system L * a * b * thereof is 30 or less.

8. - Stained aramid fibers that are dyed by the method for dyeing fibers of claim 4.

9. - The aramid fibers dyed according to claim 8, further characterized in that the brightness (value of L *) in a colorimetric system L * a * b * thereof is 30 or less.