WO2007066415A1 - Method of dyeing fibrous material of meta-type wholly aromatic polyamide - Google Patents

Abstract

A fibrous material of a meta-type wholly aromatic polyamide is dyed in a dyeing system comprising a subcritical to supercritical carbon dioxide and a dye in the presence of a polar solvent (e.g., water, methanol, acetone, propanol, or ethylene glycol). Thus, the fibrous material, which has a rigid molecular structure and high crystallizability, can be evenly dyed in a high color density from the surface to the inner part of the fibers.

Description

Specification Method for dyeing meta-type wholly aromatic polyamide fiber materials Technical field

The present invention relates to a method for dyeing meta-type wholly aromatic polyamide fiber materials. More specifically, the present invention relates to a method for dyeing a meta-type wholly aromatic polyamide fiber material uniformly and with high color density using supercritical carbon dioxide as a dyeing medium. Background technology

Conventionally, dyeing baths containing hydrogen dyes (water-soluble dyes and water-dispersible dyes or hydrogen function-imparting agents (water-soluble and water-dispersible function-imparting agents)) have been used to dye and functionalize textile materials at the same time. A method for simultaneously depleting a dye and a functional agent; a method for immersing a textile material in a treatment bath containing the dye and a functional agent, squeezing, drying, and heat identification treatment, i.e., padding; Another method is known, in which water and an auxiliary agent are mixed with the dye and the functional agent, and the treatment liquid is brought into contact with the fiber material while applying a large amount of heat energy.

However, since these conventional methods generate a large amount of processing waste liquid, efforts are being made to develop and improve technology to prevent pollution of the global environment due to this waste water. For example, a method has been developed that uses photocatalysts or microorganisms to decompose waste liquid containing dyeing materials and functional agents. However, the chemical and equipment costs required for this waste liquid treatment are high, making it difficult to put it into practical use.

In order to reduce the above-mentioned waste liquid treatment cost, JP-A-4-245-981 (Patent Document 1) discloses that supercritical carbon dioxide is used as a dyeing medium for textile materials. A method is disclosed that utilizes water and does not generate wastewater. Using this method has the advantage that it is not necessary to use large amounts of dyeing aids, and that the dye remaining in the dyeing system without being dyed can be completely recovered. However, since this process is carried out using an autoclave-type processing machine, there are problems with the uniformity of dyeing, processability, texture of the dyed material obtained, solubility of additives, utilization efficiency, etc. , is insufficient, and for this reason, the above method has not yet been put into practical use.

Furthermore, JP-A-2002-212884 (Patent Document 2) discloses a method of dyeing and functionally modifying fiber materials using a supercritical fluid, such as supercritical carbon dioxide. This method is effective for materials such as polyester fibers, but for fiber materials with a rigid molecular structure and high crystallinity, such as meta-type wholly aromatic polyamide fibers, it is necessary to remove the dye from the surface of the fiber. It is difficult to dye the inside evenly, and a solution to this problem has been desired. Disclosure of invention

The purpose of the present invention is to provide a dyeing method that can dye a meta-type wholly aromatic polyamide fiber material having a rigid molecular structure and high crystallinity uniformly from the surface to the inside with high color density. It's about doing. The above object can be achieved by the dyeing method of the present invention. That is, the inventors of the present invention, when dyeing a meta-type wholly aromatic polyamide fiber material with a dye in a supercritical carbon dioxide fluid, incorporate a specific substance into the dyeing system. The inventors discovered that the dye absorbency (exhaustion ability) of fiber materials was significantly improved by this, and based on this knowledge, they completed the present invention.

The method for dyeing a meta-type wholly aromatic polyamide fiber material of the present invention involves dyeing the meta-type wholly aromatic polyamide fiber material with supercritical carbon dioxide and a dye. When dyeing in a dyeing system containing a polar solvent, the dyeing system is characterized in that a polar solvent is contained in the dyeing system.

In the dyeing method of the present invention, it is preferable that the content of the polar solvent in the dyeing system is 5 to 100 mol% based on the molar amount of carbon dioxide.

In the dyeing method of the present invention, it is preferable that the polar solvent comprises at least one selected from water, a hydrophilic polar organic compound, and a hydrophobic polar organic compound.

In the dyeing method of the present invention, the polar solvent is a mixture of water and at least one of the hydrophobic polar organic compounds, or a mixture of water and at least one of the hydrophilic polar organic compounds and at least one of the hydrophobic polar organic compounds. Preferably, it consists of a mixture with a polar organic compound.

In the staining of the present invention, the hydrophilic polar organic compound and the hydrophobic polar organic compound, or the hydrophilic polar organic compound or the hydrophobic polar organic compound may have surface activity.

In the dyeing method of the present invention, the hydrophilic polar organic compound is methanol, ethanol, acetone, N-methyl-2-pyrrolidone, methylethyl ketone, dimethyl sulfoxide, N,N-dimethylformamide, and Preferably, it is selected from the group consisting of N, N_dimethylacetamide.

In the dyeing method of the present invention, the hydrophobic polar organic compound is preferably selected from propanol, isopropanol, butanol, benzyl alcohol, acetophenone, ethylene glycol, and acetonitrile.

In the dyeing method of the present invention, it is preferred that the dyeing is carried out at a temperature of 100 to 190 °C and a pressure of 10 to 40 MPa.

In the dyeing method of the present invention, the dye is a disperse dye or an oil-soluble dye. It is preferable to include one or more selected from the following.

In the dyeing method of the present invention, it is preferable that the dye can be dissolved or dispersed in carbon dioxide or liquefied carbon dioxide under subcritical to supercritical conditions.

The method for dyeing a meta-type wholly aromatic polyamide fiber material of the present invention uses various dyes including disperse dyes, oil-soluble dyes, etc. to dye the fiber uniformly and with high color density from the surface to the inside of the fiber. This makes it possible to dye the material.

'BEST MODE FOR CARRYING OUT THE INVENTION

The meta-type wholly aromatic polyamide forming the meta-type wholly aromatic fiber material to be subjected to the dyeing method of the present invention is:

(1) Polycondensation of aromatic polyvalent amine and aromatic polyvalent carboxylic acid halide,

(2) Polycondensation of aromatic polyvalent amine and aromatic polyvalent carboxylic acid ester,

(3) Polycondensation of aromatic polyvalent amine and aromatic polyvalent carboxylic acid, or

(4) A polyamide polymer produced by polycondensation of an aromatic polyisocyanate and an aromatic polycarboxylic acid, in which all of the two types of aromatic ring units constituting this polyamide polymer are mutually linked. It is bonded to an amide group at two positions in a meta relationship (meta-meta type), or, in one type of aromatic ring unit, it is bonded to an amide group at two positions in a meta relationship to each other. It includes polyamide polymers which are bonded to an amide group at two positions in a para relationship with each other (meta-para type) in other aromatic ring units. In addition, the aromatic ring contained in the polyamide polymer has one or more carbon atoms of 1 to 6 carbon atoms. An alkyl group having an elementary atom (preferably a methyl group) may be substituted. The meta-type wholly aromatic polyamide fiber material used in the method of the present invention includes, for example, poly( A material containing fibers containing metaphenylene isophthalamide as a main component (for example, trademark: Conex, manufactured by Teijin Ltd.) is preferably used.

There are no restrictions at all regarding the shape (long fiber, short fiber), fineness, cross-sectional shape, etc. of the meta-type wholly aromatic polyamide fiber used in the method of the present invention.

The meta-type wholly aromatic polyamide fiber material used in the dyeing method of the present invention includes fiber masses, fiber web threads, woven fabrics, knitted fabrics, and non-woven fabrics containing meta-type wholly aromatic polyamide fibers. The meta-type wholly aromatic polyamide fiber material may be composed only of meta-type wholly aromatic polyamide fibers, or it may be made of a fiber of a different type, such as a polyester fiber (for example, a polyethylene fiber). synthetic fibers such as terephthalate fibers), polyolefin fibers (e.g. polypropylene fibers), man-made fibers such as acetate fibers and polyvinyl chloride fibers, and blended fibers including natural fibers such as cotton fibers, wool fibers and hemp fibers. It may be yarn, blended yarn, interwoven fabric, etc.

There is no particular restriction on the content of the different types of fibers. However, it is generally preferable that the content is 0 to 50%.

A supercritical carbon dioxide fluid is used as the staining medium in the method of the invention. A supercritical fluid is defined as a non-condensable, dense fluid at a temperature and pressure above its critical temperature and pressure. Although the density of a supercritical fluid is comparable to that of a normal liquid, it has the same mobility (fluidity) as a gas. Therefore, supercritical fluids are liquids and It does not belong to any gas.

In the present invention, subcritical carbon dioxide is carbon dioxide that is under high temperature and high pressure conditions that form part of the hydrothermal synthesis region, but has not yet reached supercritical temperature and pressure, and specifically: The gas is produced under a high pressure that is sufficiently higher than the pressure of high-pressure processing equipment used in normal textile processing, but lower than the critical pressure, for example, 1 MPa or more and less than the critical pressure, preferably 3 to 7 MPa. or carbon dioxide in a liquid state. The temperature of subcritical carbon dioxide is below the critical temperature, preferably from 20 to 30°C.

Substances that form supercritical fluids and form gaseous or liquid fluids under subcritical phase conditions include carbon dioxide, nitrogen, water, ethanol, methanol, etc. In the method of the present invention, carbon dioxide, Carbon is used. Carbon dioxide has the advantage that it is easy to prepare subcritical to supercritical phase conditions, is highly safe, and requires low heat resistance, pressure resistance, and corrosion resistance for the equipment used.

The critical temperature of carbon dioxide is 31.1 °C and its critical pressure is 7.2 MPa.

Supercritical carbon dioxide changes its density significantly in response to small changes in pressure, has low viscosity, and has high diffusivity into the interior of fibers.Furthermore, it is suitable for various dyes. It has high solubility for dyes, and particularly for non-polar dyes. Therefore, in supercritical carbon dioxide, dyes can permeate and diffuse into the interior of various fibers. For this reason, supercritical carbon dioxide is a good dyeing medium for various dyes and fibers. However, meta-type wholly aromatic polyamide fibers have rigid polymer molecules and high crystallinity, so even if supercritical carbon dioxide is used as a dyeing medium, it cannot be applied from the surface of the fiber to its interior. It was difficult to dye uniformly. The dyeing method of the present invention solves the above problem by incorporating a polar solvent into the dyeing system containing subcritical or supercritical carbon dioxide and a dye.

The polar solvent used in the dyeing method of the present invention is composed of a liquid compound having an electric dipole structure identified in its molecule, and preferably includes water, a hydrophilic polar organic compound, and a hydrophobic polar organic compound. It consists of one or more species selected from. The hydrophilic polar organic compounds include, for example, methanol, ethanol, acetone, N-methyl-2-pykolidone, methylethylketone, dimethylsulfoxy N,N-dimethylformamide. (hidden) , N ,

N-methylacetamide (DMAc) and the like are preferably used.

In addition, examples of the hydrophobic polar organic compound include, for example, propanol

, isopropanol, butanol, benzyl alcohol, acephenone ethylene glycol, acetonitrile, and the like are preferably used.

The hydrophilic and hydrophobic polar organic compounds used as polar solvents may each have surface activity. Organic compounds with surface activity include, for example, fluorine atom-containing polar surfactants (for example, (R f CH ₂ CH ₂ 0) _x P (0) (0NH ₄ ) _y , where R f = F ( CF ₂ CF ₂ ) _z , x = 1 2 , y 2 3 X + y 3 and z = 1 7 ) etc. can be used.

In the dyeing method of the present invention, the polar solvent is a mixture of water and at least one hydrophobic polar organic compound, or at least one hydrophilic polar organic compound and at least one hydrophobic polar organic compound. It is preferable to use a mixture with an organic compound, and a polar solvent having a composition such as

is effective in improving the uniformity of dye distribution from the surface to the interior of meta-aromatic polyamide fibers and the dye distribution density (density). In the dyeing method of the present invention, the polar solvent is preferably contained in the dyeing system in an amount of 5 to 100 mol% of the molar amount of carbon dioxide, and a more preferable addition amount is 10 to 80 mol. %. If the content of the polar solvent is less than 5 mol%, the effect of its use may be insufficient, and if it exceeds 100 mol%, it may become difficult to treat dyeing waste liquid, or it may damage the fibers. Polar solvents remaining in the material may cause problems such as reduced flame resistance.

In the dyeing method of the present invention, the fiber material may be immersed in a dyeing system (dye bath) containing subcritical to supercritical carbon dioxide and a dye for a predetermined period of time, for example, 10 to 120 minutes; or, The fibrous material may be passed through the dyeing bath continuously at a predetermined speed.

Further, the fiber material may be directly introduced into the dyeing device, or may be introduced using an injection device.

Furthermore, although there are no particular restrictions on the dyes used in the method of the present invention, it _is preferable to use disperse dyes or oil-soluble dyes. It is sparingly soluble in water and can be used dispersed in water, and is usually used for dyeing polyester fibers, acetic fibers, etc. , benzothiazo-luazo, kino u n-azo, piri jin-azo, y midazole-azo, thiofu ヽ

It is possible to use dyes of the quinophthalene, styrene, and condensate dyes. Furthermore, although there is no particular restriction on the pigment solid content concentration in the dye, the higher the concentration, the easier the dyeing is <preferable>

Furthermore, as the oil-soluble dye, a dye that is soluble and dispersible in a solvent and is usually used for dope dyeing (dope dyeing) is used. In general, benzeneazo series (monoazo, disazo, etc.), heterocyclic azo series (thiazole, etc.) Oil-soluble dyes such as luazo, benzoshiazole-azo, quinolin-azo, pyridine-azo, imidazole-azo, thiopheno-nazo, etc.), anthraquinone-based dyes, etc. are used; There is no particular limit to the solid content concentration, but a higher concentration is preferable for better dyeing resistance.

These dyes are preferably dyes that can be dissolved or dispersed in supercritical carbon dioxide, subcritical carbon dioxide or liquefied carbon dioxide. Here, subcritical carbon dioxide refers to the state under conditions that do not reach supercriticality under high temperature and high pressure, which is part of the hydrothermal synthesis region.

The above dyeing treatment of meta-aromatic polyamide fibers with subcritical or supercritical carbon dioxide is preferably carried out at 100°C or higher, particularly preferably at 130 to 190°C. If the processing temperature is less than 00°C, staining spots may become apparent and processing reproducibility may be poor. Further, the processing pressure is preferably 1 OMPa or higher, and more preferably 15 to 40MPa. If the dyeing pressure is less than OMPa, reproducibility and processability may be insufficient. Therefore, the higher the processing temperature and pressure are as high as possible based on the equipment specifications, the more uniform and deep dyeing will be achieved.

In addition, the dyeing treatment time using supercritical carbon dioxide is usually 5 to 60 minutes, preferably about 10 to 30 minutes. Example

The dyeing method of the present invention will be further explained with reference to the following examples.

In the following Examples and Comparative Examples, the following physical property measurements were performed. 1. Stainability

The staining density of the dyed product was measured using a Macbeth Color-Eye model CE-3100.

The dye density of the dyed material was expressed by the brightness index. The brightness index L' uses the Y value of the tristimulus values specified in IIS Z 8701 (color display method using the 2-degree visual field XYZ system) or JIS Z 8728 (color display method using the 10-degree visual field XYZ system). Therefore, it can be obtained from the following equation. Here, the smaller the value of the lightness index L', the higher the color density.

L * = 116 ( Y/ Y n ) ^{1 / 3} - 16

YZ Y n〉 0.008856

Y: The value of Υ in the tristimulus values in the X Υ Ζ color system

Υ η: Value of Υ due to standard light on a perfectly diffuse reflective surface

However, if ΥΖΥ η is less than 0.008856, the following formula is used.

L * - 903.29 ( Υ/ Υ η )

Υ/Υη≤ 0.008856

2. Internal permeability of dye (internal diffusion)

The dyed fibers were embedded in paraffin and cut into 5-25 m thick pieces using a microtome, and the internal permeability of the dye in the cross-sectional direction of the fibers was visually observed. Those in which the dye penetrated evenly into the fibers were classified as good, and those in which the dye did not permeate were classified as poor.

Example 1

A spinning dope was prepared by dissolving 30 g of poly-m-phenylene isophthalamide with an intrinsic viscosity (IV) of 1.35 dlZ g in 110 g of N-methyl-2-pyrrolidone and defoaming under reduced pressure.

This dope was heated to _{85 °C} and wet-spun into a coagulation bath through a spinneret with a diameter of 0.07 mm and 200 holes. The composition of the coagulation bath was 40% by weight of calcium chloride, 5% by weight of NMP, and the remainder 55% by weight of water, and the temperature of this coagulation bath was 85°C. The coagulated filament thread was run about 10 cm into the coagulation bath and pulled out at a speed of 6.2 m/min. The yarn was washed with water, stretched 3.3 times in hot water at 95°C, dried on a roll at 120°C, and then stretched at 300°C. It was drawn 1.0 times on a steam hot plate to obtain a drawn yarn of 400 deZ and 200 filamen. A 20,000-denier tow was prepared by bundling 100 of these drawn yarns, crimped, and cut. The denier, cut length, strength, elongation, shrinkage rate at 300°C, and shrinkage rate at moist heat 135 of the obtained short fibers were 1.9 dtex (1.7 de), 51 mm, and 3. TcN/dtex (4.2 g/de), 43.6%, 8.4%, and 5.2%.

Using these short fibers, they are spun in the usual manner and combined to produce 30 count 2 spun yarn, which is then subjected to weaving (30Z 2 ) was obtained. Next, this fabric was refined for 20 minutes at 80° C. in a refining solution containing a refining agent (trademark: Scoreroll 400, manufactured by Kao Corporation) at a concentration of 1 g. After washing and drying this, it was pre-set at a temperature of 190°C for 1 minute.

The pre-set fabric was placed in a supercritical carbon dioxide treatment device with a capacity of 2.6 liters, and the following dye was added to the supercritical carbon dioxide fluid under supercritical conditions at a temperature of 130:0 and a pressure of 25 MPa. and polar solvent: Dye: I. Disperse Blue 56 1 % (dye weight ratio to fabric weight)

Polar solvent: Isopropanol 30 mol% (molar ratio of polar solvent to supercritical carbon dioxide molar amount)

The fabric was subjected to a dyeing treatment for 30 minutes in a dyeing system containing.

The obtained dyed product was washed with acetone and subjected to the above evaluation. As a result, the L' value of the dyed product was 55.1, indicating that the internal permeability of the dye was good.

Example 2

Dyeing was carried out in the same manner as in Example 1 and evaluated. however, The L' value of the dyed product obtained by using water instead of isopropanol as a polar solvent was 53.6, and the internal permeability of the dye was good.

Example 3'

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, benzyl alcohol was used instead of isopropanol, which was used as a polar solvent.

The L' value of the dyed product obtained was 52.3, indicating good internal penetration of the dye.

Example 4

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, instead of the isopropanol used as the polar solvent, a mixture of water and isopropanol (weight ratio ^ l Z l ) was used.

The L* value of the obtained dyed product was 55.8, and the internal permeability of the dye was good.

Example 5

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, instead of the isopropanol used as the polar solvent, a mixture of water and benzyl alcohol (weight ratio = 1:1) was used.

The L* value of the dyed product obtained was 51.7, indicating good internal penetration of the dye.

Example 6

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, methanol was used instead of isopropanol, which was used as a polar solvent.

The L* value of the obtained dyed product was 57.0, indicating that the internal permeability of the dye was good. there were.

Example 7

Dyeing was carried out and evaluated in the same manner as in Example 1. However, instead of isopropanol, which was used as a polar solvent, a fluorosurfactant containing a compound of formula (1) below was used.

Fluorine surfactant (trademark: Zonyl, manufactured by DuPont) Composition: Compound of the following formula (1) 35% by weight

Water 45% by weight

ii Sopropanol 20% by weight

(RfCH ₂ CH ₂ 0) _x P (0) (0NH ₄ ) _y ... (1) However, in the above formula, Rf = F (CF ₂ CF ₂ ) z, x = :!~ 2, y = 2 ~3, x + y = 3, and z = l~7.

The L' value of the dyed product obtained was 57.5, indicating good internal permeability of the dye. ..

Example 8

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, the amount of isopropanol used as a polar solvent was changed from 30 mol% to 50 mol%.

The L' value of the dyed product obtained was 45.4, indicating good internal permeability of the dye.

Example 9

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, the temperature of the staining system was changed from 130°C to 150°C.

The L' value of the dyed product obtained was 46.1, indicating good internal permeability of the dye.

Example 10

Dyeing was carried out in the same manner as in Example 1 and evaluated. however, The temperature of the staining system was changed from 130 to 170 °C.

The L' value of the dyed product obtained was 40.2, indicating good internal permeability of the dye.

Comparative example 1

Dyeing was carried out in the same manner as in Example 1 and evaluated. However, isopropanol was not used.

The L' value of the obtained dyed product was 75.2, and the internal permeability of the dye was poor.

Comparative example 2

Dyeing processing was carried out in the same manner as in Example 10, and evaluation was performed. However, isopropanol was not used.

The ^L4 value of the dyed product obtained was 6.5.4, and the internal permeability of the dye was poor. Industrial applicability

According to the method of the present invention, it is possible to dye various dyes efficiently, uniformly to the inside of fibers, and with high color density. Furthermore, according to the method of the present invention, it is possible to reduce dyeing process waste liquid as much as possible, and also to recover the waste liquid and the dye, and to reuse it if necessary. Therefore, according to the present invention, not only can a meta-type aromatic polyamide fiber material dyed at a high concentration, which could not be obtained using conventional techniques, be provided, but also it can be effective in improving the global environment. It has extremely high industrial value.

Claims

1. When dyeing a meta-type wholly aromatic polyamide fiber material in a dyeing system containing carbon dioxide under subcritical to supercritical phase conditions and a dye, the dyeing system contains a polar solvent. A method for dyeing a meta-type wholly aromatic polyamide fiber material. helmet 2. The dyeing method according to claim 1, wherein the content of the polar solvent in the dyeing system is 5 to 100 mol% based on the molar amount of the carbon dioxide. of 3. The dyeing method according to claim 1, wherein the polar solvent comprises at least one selected from water, a hydrophilic polar organic compound, and a hydrophobic polar organic compound. 4. The polar solvent is a mixture of water and at least one of the hydrophobic polar organic compounds, or at least one of the hydrophilic polar organic compounds and at least one of the hydrophobic polar organic compounds. The dyeing method according to claim 3, comprising a mixture of. 5. The method according to claim 3 or 4, wherein the hydrophilic polar organic compound and the hydrophobic polar organic compound, or the hydrophilic polar organic compound or the hydrophobic polar organic compound have surface activity. Dyeing method. 6. The hydrophilic polar organic compound is methanol, ethanol, acetone, N-methyl-2-pyrrolidone, methylethylketone, dimethylsulfoxide, N,N-dimethylformamide, and N-dimethylacetone. The dyeing method according to claim 3 or 4, which is selected from the group consisting of: 7. The third or third claim, wherein the hydrophobic polar organic compound is selected from propanol, isopropanol, butanol, benzyl alcohol, acetophenone, ethylene glycol, and acetonitrile. is the staining method described in Section 4. 8. The dyeing method according to claim 1, wherein the dyeing is carried out at a temperature of 100 to 190 °C and a pressure of 10 to 40 MPa. 9. The dyeing method according to claim 1, wherein the dye includes one or more selected from disperse dyes and oil-soluble dyes. 10. The dyeing method according to claim 1 or 9, wherein the dye can be dissolved or dispersed in carbon dioxide or liquefied carbon dioxide under subcritical to supercritical conditions. ·