JPH03193916A - Conjugate fiber dyed with cationic dye - Google Patents

Abstract

PURPOSE:To obtain a conjugate fiber exhibiting clear color and containing a core part and a sheath part having respective specific percentage exhaustions by carrying out cationic dyeing of a conjugate fiber composed of a polyester modified with a sulfonated aromatic dicarboxylic acid as the core part and a polyamide modified with a sulfonated aromatic dicarboxylic acid as the sheath part. CONSTITUTION:A conjugate fiber is produced by using a polyester copolymerized with a sulfonated aromatic dicarboxylic acid [preferably 5-sulfoxyisophthalic acid (salt)] as the core part and a polyamide copolymerized with a sulfonated aromatic dicarboxylic acid as the sheath part and spinning the polymers in a concentric core-sheath form at a core : sheath ratio of preferably (80-25):(20-85). The objective conjugate fiber dyed with cationic dye, having excellent light-fastness and cleaning-fastness of the dyed color and useful for clothes can be produced by the cationic dyeing of the above conjugate fiber in such a manner as to get the percentage exhaustion of the sheath part of <=0.2%owf and corresponding to <=10% of that of the core part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides dyeing with excellent light fastness and washing fastness,
The invention also relates to dyed composite fibers that provide vivid colors.

[Prior Art] Polyamide fibers such as nylon 6 and nylon 66 are used in many clothing applications due to their excellent strength, abrasion resistance, deep dyeability, and ease of resin processing. ing. In particular, nylon dominated sports outerwear, especially ski wear, which required special color development and resin processability.

However, in recent years, fashion has become more diverse and its uses have expanded, and bright colors are now required for ski wear, swimwear, casual wear, etc. The greatest advantage of polyamide is that it can be dyed into deep colors with acid dyes, and it can be dyed into vivid colors, but conversely, when dyed with vivid colors, the color fades significantly due to light and the color fastness is poor. However, it has been considered difficult to put it into practical use in applications where both vivid color and color fastness are strongly required.

Furthermore, although the sulfonated aromatic dicarboxylic acid-modified polyamide that can be dyed with cationic dyes as disclosed in U.S. Pat. It is said that it is difficult to apply it to clothing applications where wash resistance is important, and it is only used in a few areas such as carpets.

On the other hand, polyesters, such as polyethylene terephthalate, are generally dyed with disperse dyes, and although progress has been made in improving their coloring properties and migration/sublimation properties, the depth of vivid colors still falls short of that of nylon in many areas. Further, due to its molecular and chemical structure, polyester is resistant to abrasion and has insufficient resin processability. The dyeability of this polyester can be greatly improved by using a sulfonated aromatic dicarboxylic acid-modified polyester as the polymer and dyeing it with a cationic dye, as described in Japanese Patent Publication No. 34-10497. However, the above-mentioned disadvantages inherent to polyester (insufficient abrasion resistance and resin processability) are not improved, but rather tend to get worse.

In addition, there are many methods of composite spinning polyamide and polyester into a core-sheath type to take advantage of the advantages of both. It is used in combination of homopolymers, and the dyeing should be a disperse dye dyeing in which both are dyed together, or a mixed dyeing with an acid dye and a cationic dye or a disperse dye to obtain sufficient color development. However, the dyed products obtained by the former disperse dye dyeing are not practical due to insufficient washing fastness of polyamide.Also, the dyed products obtained by the latter mixed dyeing are However, this method has not been put to practical use because of the problem of poor light fastness on the polyamide side that has been vividly dyed with an acid dye.

[Problems to be Solved by the Invention] The present invention can be used as a dyed product dyed with vivid colors, and has excellent color development and color fastness in terms of light fastness, washing resistance, and abrasion resistance.
Moreover, the main objective is to provide a dyed composite fiber that is strong and has good resin processability.

[Means for Solving the Problems] The present invention comprises a sulfonated aromatic dicarboxylic acid-modified polyamide in the sheath, a sulfonated aromatic dicarboxylic acid-modified polyester in the core, and substantially only a cationic dye. is a core-sheath type composite fiber dyed with dye, wherein the dye dyeing rate of the sheath portion is 10% or less of the dye dyeing rate of the core portion,
The fiber is made of a composite fiber dyed with a cationic dye having a concentration of 0.2% owl or less.

One of the features of the present invention is that a sulfonated aromatic dicarboxylic acid-modified polyester (hereinafter abbreviated as modified polyamide) is used.
This is a core-sheath type composite fiber with a composite structure covering a polyester (hereinafter abbreviated as modified polyester).

Another feature is that the above-mentioned core-sheath type composite fiber is dyed with substantially only a cationic dye, and moreover, the dye dyeing rate of the sheath portion and the core portion is a specific value. That is, the dye dyeing rate of the sheath is 10% or less of the dye dyeing rate of the core, and
It is important that the content be 0.2% owf or less, preferably 0.1% owl or less.

In order to satisfy this dyeing rate condition, it is sufficient to use dyeing conditions that allow the modified polyester to be dyed, such as high temperature dyeing at a temperature of about 100 to 120°C. In such high-temperature dyeing, a large amount of dye is absorbed by the modified polyester, but the amount absorbed by the modified polyamide is quite small.
It is capable of satisfying the dyeing rate conditions described above.

Even though the sheath (modified polyamide) is hardly dyed, the fiber as a whole exhibits excellent color development. Moreover, even if the dye is present in the sheath (modified polyamide), the amount (dye dyeing rate) is suppressed to a specific level, thereby providing excellent light fastness and washing fastness. That is, the dye dyeing rate of the sheath part is 0.2%.
If it exceeds ov[, the washing fastness and light fastness will be significantly reduced. In addition, even if this dyeing rate is 0.2% owl or less, if it exceeds 10% of the dye staining rate of the core,
It is difficult to obtain a sufficient level of light fastness.

The dye dyeing rate of the core portion may be set to an arbitrary level depending on the desired degree of dyeing. In order to obtain color development that can be discerned with the naked eye, in the case of light-dyed products, it is generally sufficient to have a dye dyeing rate of 0.01% ovf or more.

In addition, in the case of dark-dyed products, in practical terms, 50% o
A dye dyeing rate of wl or less is preferred.

The dye dyeing rate of the sheath or core as used in the present invention is a value expressed as a percentage of the amount of dye dyed with respect to the polymer of the sheath or core.For example, the dye dyeing rate of the sheath 0.2% owl or less means that the amount of dye dyed per 1 g of modified polyamide of the sheath portion is 0.002 g or less.

The dye dyeing rate of the sheath or core may be determined by the following method.

Dye dyeing rate of the sheath: Weigh a certain amount (200cm) of dyed composite fiber or its fabric, and heat it at 30°C.
It was immersed in 30 ml of 88% formic acid solution for 3 minutes to dissolve the sheath modified polyamide and the dye dyed therein.
The absorbance at the maximum absorption wavelength is measured using a tometer'. In addition, a certain amount (200 μ) of the sample before staining was weighed, and a predetermined amount (0
, 25mg, 0. It is dissolved with 5 mg or 1.0 ml of dye, the absorbance is determined using a colorimeter, and the relationship between absorbance and dyeing rate for this dye is plotted as a calibration curve. Using this calibration curve, the amount of dyeing is determined from the absorbance value of the actual dyed sheath modified polyamide described above.

Dye dyeing rate of the core: First, the modified polyamide sheath of the composite fiber or its products is dissolved and removed, and then washed with water to obtain a dyed fiber containing only the modified polyester of the core. Weighing a certain amount (100 cm) of the dyed fiber,
Phenol/tetrachloroethane mixed solution (weight ratio 3:2) 3
After completely dissolving the mixture at about 60°C, the absorbance at the maximum absorption wavelength is measured using the same colorimeter as above.

In addition, using the modified polyester fibers taken out from the sample before dyeing, a calibration curve showing the relationship between absorbance and dyeing rate was determined in the same manner as described above, and from this calibration curve, Determine the amount of dyeing of the core modified polyester.

Then, from the values of the amount of dye dyeing in the sheath and core (in order, a%owf and b%owl, respectively),
The dyeing ratio of the sheath to the core is calculated using the formula (a/b)X100.

The modified polyamide used for the sheath in the present invention is a modified polyamide in which a compound having a sulfone group is bonded to a part of the polyamide chain or the terminal end, or a compound having a sulfone group. It can be produced by adding it in the form of a free acid or an alkyl ester and copolymerizing it. This sulfonated aromatic dicarboxylic acid is
It is not substantially eluted and removed by washing or cleaning.

Polyamides that serve as the pace include polyε-capramide (nylon 6), polyhexamethylene adipamide (
Nylon 66) is typically used, but polyamides obtained from other polymerizable monomers, such as laurolactam, sebacic acid, paraxylylene diamine, isophthalic acid, etc., or copolyamides thereof may also be used.

Further, a typical example of the sulfonated aromatic dicarboxylic acid is 5-sulfoxyisophthalic acid represented by the following chemical formula (1) or a salt thereof.

The copolymerized amount of the sulfonated aromatic dicarboxylic acid is preferably about 0.25 to 3 mol % based on the monomer of the pace polyamide. If the copolymerization amount is too low, it will be difficult to obtain the original effects of the modified polyamide, and if it is too large, the effect of the copolymerization of the sulfonated aromatic dicarboxylic acid will reach saturation. character is damaged.

This modified polyamide may contain a matting agent such as titanium oxide, but in order to sufficiently transmit the color of the core polyester and obtain excellent color development, it is necessary to add a matting agent and other pigments. It is preferable that these are substantially not included.

Further, these polyamides may contain an antistatic agent, a heat resistant agent, a light resistant agent, etc. in an amount that does not significantly reduce the light transmittance.

The modified polyester used for the core in the present invention is a modified polyester in which a compound having a sulfone group is contained in a part of the polyester chain or end.
It is described in Japanese Patent No. 4-10497. This modified polyester is a modified polyester obtained by copolymerizing polyethylene terephthalate, polybutylene terephthalate, or a copolymerized polyester containing these as main components with a sulfonated aromatic dicarboxylic acid or a salt thereof.

A representative example of the sulfonated aromatic dicarboxylic acid is 5-sulfoxyisophthalic acid represented by the chemical formula (1) or a salt thereof.

These dicarboxylic acids are added in the form of free acids or alkyl esters during polyester polymerization and copolymerized to produce modified polyesters. The copolymerized amount of the sulfonated aromatic dicarboxylic acid is preferably about 0.5 to 6 mol% relative to terephthalic acid. If the copolymerization amount is too low, it is difficult to obtain the desired effect of the modified polyester, and if it is too high, the crystal structure of the modified polyester is disturbed, resulting in undesirable phenomena such as a significant decrease in mechanical properties.

Note that these modified polyesters may contain an antistatic agent, a light-resistant agent, a heat-resistant agent, a matting agent, and the like.

The core-sheath composite ratio of modified polyamide and modified polyester can be set arbitrarily within a range that does not lose the effect of the present invention, but
The modified polyamide ratio is preferably 20 to 75% by weight. If the modified polyamide ratio is too low, it is difficult to form a uniform coating, and moreover, the sheath portion is often torn during processing such as weaving, dyeing, and finishing, resulting in a loss of commercial value. On the other hand, if it is too high, the color of the dyed modified polyester core will be blocked and it will be difficult to obtain the desired color development.

The arrangement of the modified polyamide sheath and the modified polyester core is basically preferably in the form of a concentric sheath, but as long as the sheath is too thin to break, it may be eccentric or multi-core. Further, if it is possible to cover the modified polyester core with a modified polyamide sheath, a deformed yarn can be used.

This core-sheath type composite fiber may be made into a product by spinning, knitting and weaving, and dyeing by conventional methods.

First, a modified polyamide and a modified polyester are melted separately, introduced into a spinning pack section, formed into a composite flow so as to have a core-sheath structure in a conventional manner, and then spun out from a nozzle.

The spun filament yarn is taken up at a predetermined speed, oiled, and then wound into a package. Next, the previously wound yarn is placed in a draw twister to obtain the desired strength and elongation.
Stretch as usual. This stretching may be performed continuously without winding up the spun yarn after it has been taken off. Alternatively, a method may be used in which the desired fiber performance is obtained all at once by taking the fiber at a high speed of 4000 m/min or more.

In the direct spinning and drawing method, for example, the spun yarn is
Taken off at 5000 m/min, then stretched, 3000 m/min.
A method of stretching and heat-setting at 5500 m/min can be mentioned.

The obtained composite fiber is dyed with a cationic dye in a conventional manner at any subsequent step.

As this cationic dye, for example, '^1xenCa
jhilon' (manufactured by Hodogaya Chemical Industry ■), 'Kay
acBl' (manufactured by Nippon Kayaku ■), 'Esjrol,
Sumiacr! B (manufactured by Sumiya Kagaku Kogyo ■), 'Dia
cr7bi (manufactured by Mitsubishi Chemical Corporation), 'Maxilon'' (
Examples include, but are not limited to, dyes with named names such as Ciba Geigy (trade name) and ^5train' (manufactured by Bayer Japan Corporation), and dispersed cationic dyes may also be used. Other dyes may be used in combination as long as the amount is within a range that does not impede the effects of the present invention.

The dyed composite fiber according to the present invention is particularly suitable for clothing products that are repeatedly washed, but can also be used for interior goods such as carpets and car seats.

[Function] In the polyester/polyamide core-sheath type composite fiber according to the present invention, the modified polyester core is sufficiently dyed, and the modified polyamide in the sheath is dyeable with cationic dyes but is only slightly dyed. It is in a state where there is no.

However, this dyed composite fiber has sufficient color development even though the sheath portion is only slightly dyed.

This is because dye molecules move extremely easily inside the modified polyamide sheath, so if the dye concentration is the same, the dye that would originally be dyed on the modified polyamide sheath is exhausted by the modified polyester core, resulting in color development. This is because the color development of the core is hardly inhibited by the sheath and is recognized as the color development of the entire composite fiber.As a result, a sufficient level of vivid color development can be obtained. Conceivable.

In addition, the dye exhaustion rate is high enough to provide vivid color development, and sufficiently excellent light fastness, fastness, and washing fastness are exhibited. This is because the amount of dye exhausted in the modified polyamide sheath is extremely small, so the amount of dye that comes off during washing is small.
Since a phenomenon occurs in which a portion of the shed dye migrates into the polyester core, it is thought that excellent washing fastness can be obtained even with modified polyamide. Furthermore, even though the modified polyamide sheath is dyed, it has almost the same excellent light resistance as polyester fiber. This is also thought to be due to the fact that even if a very small amount of dye in the modified polyamide sheath portion causes fading, it hardly affects the color development of the fiber as a whole. Therefore, the light fastness and washing fastness in bright colors are improved to a level that cannot be achieved with modified polyamide fibers, and it is possible to achieve a practically usable color fastness. For example, it becomes possible to put into practical use certain vivid color dyes, which were previously difficult to use due to their poor light fastness.

Furthermore, since the modified polyamide with a low refractive index covers the surface of the modified polyester, surface reflection is reduced and the depth of color is increased.

Moreover, the dyed composite fiber according to the present invention also has the abrasion resistance and ease of resin processing inherent to polyamide. Furthermore, by having a modulus intermediate between polyamide and polyester, it is possible to impart desirable tension and elasticity to the fabric, and as a secondary effect, it has the effect of improving dimensional stability against water, which is considered to be a disadvantage of polyamide. It can also exhibit anti-wrinkle effects. .

Because it has both of these characteristics, the composite fiber according to the present invention exhibits a particularly remarkable effect in clothing fabrics used for repeated washing. Of course, even car seats and carpets that are washed infrequently have unprecedented color development.
A product with sharpness can be obtained. Moreover, by using modified polyamide as a sheath, a depth of color not seen in conventional cationically dyeable polyester can be obtained.

[Example] Example 1 0.5 mol % of 5-sulfoxyisophthalic acid was added to ε-caprolactam and polymerized in a conventional manner to give 98%
A modified nylon 6 having a sulfuric acid relative viscosity of 2.6 and containing substantially no titanium oxide was obtained.

In addition, polyethylene terephthalate raw materials consisting of ethylene glycol and terephthalic acid were added with a catalyst and 5-sulfoxyisophthalic acid (1% to terephthalic acid) as usual.
．． 5 mol %) and polymerized to obtain modified polyethylene terephthalate (abbreviated as modified polystyl) having an intrinsic viscosity (IV) of orthochlorophenol of 75<0.64.

The above-mentioned modified nylon 6 and modified polyester are subjected to an extruder type composite spinning machine, melted separately, then weighed in equal amounts, and then mixed in the composite spinning pack so that the modified polyester becomes a core and the modified nylon 6 serves as a sheath. A composite flow is formed and discharged, taken off at a speed of 1500 m/min, then heat-set with a drawing hot roller (160°C), and then drawn at a speed of 4000 m/min.
The yarn was wound up in minutes to obtain a drawn yarn of 24 filaments of 70 denier.

This drawn yarn is subjected to warp and weft yarns, and a plain woven fabric (warp density 11
8 pieces/2.5 Jan, weft density 85 pieces/2.54 an)
was woven. This plain woven fabric is called “Sundead” G-29.
Desizing and scouring were carried out at 98°C for 20 minutes in a treatment bath containing 2 g/l (manufactured by Sanyo Chemical Co., Ltd.), 5 g/l soda ash, and 2 g/l "Butrol" WR-14 (manufactured by Meisei Chemical Co., Ltd.). After that, it was dried and subjected to intermediate setting at 170°C to obtain a sample fabric for dyeing.

The sample fabric was dyed with cationic dye: 'Diac+71 R
edGRL-N' conc (manufactured by Mitsubishi Chemical Corporation)
0.5% owl, 0.5cc of acetic acid (80%) as auxiliary agent
Mini-coloring was carried out at 120° C. for 30 minutes in a bath of 200° C. (Example 1).

In addition, for comparison, the above sample fabric was mixed and dyed under the following conditions. Cationic dye “old xcr71 RedGRL-”
N (manufactured by Mitsubishi Chemical Corporation) 0.25% owl, acid dye 'Digcid Aro, Rubiol 3GS'
250% (manufactured by Mitsubishi Chemical Corporation) 0.25% owl
- In a bath containing 0.5% owl of "Ospin 700-CD" (manufactured by Tokai Oil Co., Ltd.) as an auxiliary agent and 0.5 cc/l of acetic acid,
Mini-coloring was carried out at 120° C. for 30 minutes (Comparative Example 1).

From the obtained dyed fabric, the dye dyeing rate of the sheath or core of the component composite fibers was measured under the condition of a maximum absorption wavelength of 537 nm, and the color development, light fastness, and washing fastness were also measured.

The results were as shown in Table 1.

Color development: Color was measured using a multi-light source spectrophotometer (manufactured by Suga Test Instruments Co., Ltd.) under the condition of a C light source of 65° and expressed as an L value. If the color development is poor, it will appear whitish (and exhibit a high L value).

Light fastness was measured by the method of JIS LO842.

Washing fastness was measured by the method of JIS LO844. However, color fading was measured by comparing the color difference observed between each color chart of the contamination gray scale and grading the degree of color fading.

As shown in the results in Table 1, the dyed core-sheath type composite fiber according to the present invention had excellent color fastness despite the presence of a polyamide layer on the fiber surface, and also had excellent color development. . On the other hand, in the case of Comparative Example 1 using mixed dyeing, the dyeing fastness was poor, especially the color fading during washing, and the product did not satisfy the practical level.

Example 2 Using the dyed sample fabric obtained in Example 1, dyeing was carried out under the following conditions. wavelength 6
The color development, light fastness and washing fastness were measured in the same manner as in Example 1, and the results are also shown in Table 1 as Example 2.

Cationic dye 'Ka7acr71 Black R-E
D' (manufactured by Nippon Kayaku Co., Ltd.) 10% owl, acetic acid (
80%) 0.5cc/l, mini-color at 120°C for 45 minutes, and then "Rakkor PSK" (manufactured by Meisei Kagaku ■: anionic activator) 0. 5 g/l, acetic acid (80%
)0.2g/! , soaping was carried out at 60° C. for 20 minutes, washed with water, and then dried.

In addition, for comparison, a sample fabric for dyeing was produced by melt spinning using only the same modified polyester as used in Example 1, direct spinning drawing, weaving, and scouring in the same manner as in Example 1, and cation A dyed fabric was produced by dyeing and soaping. The dyeing characteristics were measured in the same manner as in Example 1, and the results are also shown in Table 2 as Comparative Example 2.

As shown in the results in Table 2, the dyed core-sheath type composite fiber according to the present application had a smaller L value and a deeper dyed product than that of Comparative Example 2. Moreover, it had excellent color fastness despite the presence of a polyamide layer on the fiber surface.

Example 3 Using the same modified nylon 6 and modified polyethylene terephthalate as in Example 1, melting was carried out in the same manner as in Example 1 except that the composite ratio of modified nylon 6 was changed to 10.25.50.75.90% by weight, respectively. A 40 denier 12 filament composite fiber yarn was obtained by spinning and direct spinning drawing. After knitting these fiber yarns into a 28 gauge half tricot, Dimcr71 Red G was knitted in the same manner as in Example 1.
It was dyed with RL-N' (manufactured by Mitsubishi Chemical Industries, Ltd.), and its dyeing characteristics were measured in the same manner as in Example 1.

Incidentally, the nylon sheath coating tear was determined by taking an enlarged surface photograph of the fibers constituting the dyed fabric and determining whether or not destruction of the nylon sheath layer was observed.

The results obtained are as shown in Table 3.

Washing fastness and light fastness were both at a practical level, but color development was insufficient when the nylon 6 ratio exceeded 75% by weight. Furthermore, when the nylon 6 ratio was less than 20% by weight, it was difficult to uniformly cover the modified polyester core with the nylon sheath, and the sheath was sometimes damaged during spinning and drawing or knitting and finishing.

When comparing the fabric tension and waist, the sheath nylon ratio is 2.
The texture was good when it was 0 to 75% by weight, and the feel was more preferable than a fabric made of nylon 6 alone or a fabric made of polyethylene terephthalate alone.

[Effects of the Invention] When the dyed composite fiber according to the present invention is used, it is possible to obtain an excellent textile product that has both vivid color and excellent light fastness and washing fastness.

That is, this color fastness is so excellent that it could not be obtained with vivid color fiber products made of polyamide fibers or modified polyamide fibers.

Furthermore, since the modified polyester layer exists in the core, it has excellent dimensional stability and wrinkle resistance, and has appropriate tension and stiffness.

In addition, fabrics made only of modified polyester fibers have drawbacks such as insufficient abrasion resistance and resin processability.
This is improved by disposing a modified polyamide layer on the sheath, and the depth of the color is also improved.

Since it has these properties, the composite fiber according to the present invention can be suitably used for sportswear, outerwear, etc., which are required to be excellent in both vivid color and color fastness.

Claims (2)

[Claims] (1) A core-sheath type composite fiber in which sulfonated aromatic dicarboxylic acid-modified polyamide is arranged in the sheath part, sulfonated aromatic dicarboxylic acid-modified polyester is arranged in the core part, and substantially only cationic dye is dyed. A composite fiber dyed with a cationic dye, wherein the dye dyeing rate of the sheath portion is 10% or less of the dye dyeing rate of the core portion and 0.2% owf or less. (2) The composite fiber dyed with a cationic dye according to claim 1, wherein the composite ratio of the polyamide sheath portion is 20 to 75% by weight.