JPH07300724A - Sheath-core type conjugate fiber, its production and dyed conjugate fiber - Google Patents

Abstract

PURPOSE:To obtain a dyed sheath-core type conjugate fiber excellent in color developability, light resistance, resistance to washing and wear fastness, good in resin finishability and split resistance between sheath and core, and high in durability. CONSTITUTION:This sheath-core type conjugate fiber is made up of sheath consisting of a polyamide and 20-60wt.% of core consisting of a copolyester composition comprising 0.1-5wt.% of sodium 5-sulfoisophthalate and a copolyester copolymerized with 1.0-10mol% of a sulfonated aromatic dicarboxylic acid. The other objective dyed fiber is obtained by dyeing the core of the above conjugate fiber with a cationic dye.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in durability of a core-sheath type composite fiber which is excellent in light fastness to dyeing and fastness to washing and which can obtain a vivid color.

[0002]

2. Description of the Related Art Polyamide fibers represented by nylon 6 and 66 have been used in many clothing applications because of their excellent strength, abrasion resistance, deep dyeability, and ease of resin processing. There is. Among them, sports outerwear, especially ski wear, which is particularly required to have color developability and resin processability, was a unique place for polyamide fibers.

However, in recent years, fashion has become more diversified and its applications have expanded, and clear colors have been required for ski wear, swimwear, casual wear and the like.
Polyamide has the greatest advantage that it can be dyed in a deep color with an acid dye, and it can be dyed in a vivid color.On the contrary, in vivid color, the discoloration due to light is remarkable, and the dyeing fastness is inferior. It was considered to be difficult to put into practical use for applications requiring bright colors.

On the other hand, polyester fibers typified by polyethylene terephthalate have generally been dyed with disperse dyes for many years, and their coloring properties and transfer sublimation properties have been improved, but in the depth of vivid colors, they are still polyamide fibers. There are many parts that do not reach. Furthermore, polyester fibers are vulnerable to wear, and resin workability is not sufficient. The dyeability of this polyester fiber can be significantly improved by using a sulfonated aromatic dicarboxylic acid copolymer polyester as a polymer and dyeing this with a cationic dye, as described in JP-B-34-10497. However, the above-mentioned drawbacks inherent to polyester (insufficient abrasion resistance and resin processability) are not improved, but tend to be worse.

Further, many means have been proposed to utilize the advantages of both of the composite spinning of polyamide and polyester. In that case, the dyeing should be a disperse dye dyeing in which both are dyed or an acid dye and a cation. Mixed dyeing with a dye or a disperse dye is required to obtain sufficient color development. However, the dyed product obtained by the former disperse dyeing does not satisfy the practical level because the washing fastness of polyamide is insufficient. Further, the dyed product obtained by the latter mixed dyeing has not been put into practical use because the polyamide-side dyed in a bright color has a problem of poor light fastness.

Therefore, in order to solve these problems,
JP-A-3-193982 proposes a core-sheath type composite fiber in which polyamide is arranged in a sheath portion, sulfonated aromatic dicarboxylic acid copolymerized polyester is arranged in a core portion, and a cationic dye is dyed only in the core portion. ing.

[0007]

However, in this core-sheath type composite fiber, since the polyamide and the polyester, which are essentially inferior in mutual adhesiveness, are compounded, the adhesion between the core and the sheath is insufficient. Is. Therefore, depending on the condition of use, the interface peels off between the core and the sheath with the lapse of time, resulting in a significant decrease in color developability, and further fibrillation of the sheath, resulting in a durability In terms of aspects, I was still not satisfied.

The present invention solves the above-mentioned drawbacks of the prior art and is excellent in color development, light resistance, washing resistance and abrasion fastness, even as a dyed product dyed in a vivid color.
The main purpose is to provide a composite fiber that is strong, has good resin processability, and has high durability.

[0009]

In order to achieve this object, the core-sheath type composite fiber of the present invention comprises polyamide in a sheath portion,
Sulfonated aromatic dicarboxylic acid is 1.0 mol% or more 10
Mol% or less copolymerized polyester is placed in the core, and the ratio of the core is 20% by weight or more and 60% by weight or less.
-It is characterized in that sodium sulfoisophthalate is contained in an amount of 0.1% by weight or more and 5% by weight or less.

As the polyamide forming the sheath, an aliphatic polyamide and an aromatic polyamide can be used.
Copolyamides may be used as long as the effects of the present invention are not impaired, but aliphatic polyamides in which 80% or more of polyhexamethylene adipamide is polyhexamethylene adipamide are preferably used from the viewpoint of adhesion to the core.

Although the reason why polyhexamethylene adipamide is superior to other polyamides in terms of adhesiveness with the core copolyester is not always clear, the interaction with the sulfone group of the core copolyester is not clear. It is considered that this is because it is stronger, the swelling due to moisture absorption is smaller than that of other polyamides, and the strain stress at the core-sheath interface is small.

If necessary, the polyamide used for the sheath portion may contain a matting agent such as titanium oxide, an antistatic agent, a light-proofing agent, etc., but the color development is made more effective. From the point of view, it is preferable to suppress the content of the matting agent to 0 to 0.1% by weight.

The core is made of a normal polyester such as polyethylene terephthalate or polybutylene terephthalate,
It must consist of a polyester copolymerized with a specified amount of sulfonated aromatic dicarboxylic acid. This sulfonated aromatic dicarboxylic acid is represented by 5-sulfoisophthalic acid and its salts.

The copolymerization rate of the sulfonated aromatic dicarboxylic acid is required to be 1 to 10 mol%. When the copolymerization rate is 1 mol% or more, a practically sufficient level of color developability can be obtained by dyeing with a cationic dye. It is preferably 1.5 mol% or more. On the contrary, a polyester copolymerized in excess of 10 mol% has practically high mechanical strength.
Is insufficient. It is preferably 8 mol% or less.

It is necessary that sodium sulfoisophthalate is added to the copolyester of the core, and the sodium 5-sulfoisophthalate has an adhesive property between the core polymer and the sheath polymer. Contribute to improve.

The content thereof is required to be 0.1% by weight or more and 5% by weight or less. Preferably 0.5% by weight or more and 3% by weight
It is the following. If it is less than 0.1% by weight, a sufficient effect of improving the adhesiveness cannot be exhibited. If it exceeds 5% by weight, the mechanical strength is lowered and it becomes insufficient for practical use. Although the mechanism of action of the adhesiveness improving effect due to the inclusion of sodium 5-sulfoisophthalate in the core is not clear, the mutual action of the polar group portion of 5-sulfoisophthalate sodium and the amino group or amide group of polyamide It is thought to be due to the action.

In addition, it has both excellent color development and adhesiveness,
In order to achieve the intended object of the present invention, it is necessary to set the composite ratio of the core portion to 20% by weight or more and 60% by weight or less.
If the amount is less than 20% by weight, the practically sufficient color development which is the object of the present invention cannot be obtained. On the other hand, if it exceeds 60% by weight, the adhesiveness between the core and the sheath is deteriorated and desired durability cannot be obtained. It is preferably 30% by weight or more and 50% by weight or less.

The composite fiber of the present invention is preferably a concentric core-sheath composite, but the core may be eccentric.
However, even in the case of eccentricity, the thickness of the sheath is 1μ at the thinnest part.
It is desirable that the thickness is at least m in terms of durability. The number of cores may be one or more, but it is 3 in terms of the effect of color development.
The following are preferred. The shape of the core may be circular or non-circular.

In order to obtain a sufficiently excellent color-developing effect, the core-sheath type composite fiber of the present invention is substantially dyed only with a cationic dye, and the dyeing rate of the sheath and the core is set to a specific value. Preferably.

That is, the dyeing rate of the sheath is set to 10% or less, more preferably 5% or less of the dyeing rate of the core, and the dyeing rate of the sheath is 0.2% owf. Hereafter, it is more preferably 0.1% owf or less, and even more preferably 0.05% owf or less.

Satisfying this dyeing rate condition is effective for obtaining a dyed product having excellent color developability, fastness to light and fastness to washing. If the dye dyeing ratio of the sheath exceeds 0.2% owf, the fastness to washing and the fastness to light are deteriorated. Also,
Even when the sheath dyeing ratio is 0.2% owf or less, if the dyeing ratio of the core is higher than 10%, it is difficult to obtain a sufficient level of light fastness.

The dyeing rate of the core may be set to any level according to the desired degree of dyeing. In order to obtain a color developable with the naked eye, in the case of a light dyeing product, generally 0.0
A dyeing rate of 1% owf or more should be taken. Further, in the case of a deep-dyeing product, a dyeing rate of 50% owf or less is preferable from the practical viewpoint of cost.

The dyeing ratio of the sheath or core in the present invention is a value which represents the dye amount dyed to the polymer of the sheath or core as a percentage. For example, the dye of the sheath The dyeing ratio of 0.2% owf or less means that the dyeing amount of 0.001 g or less of the dye per 1 g of polyamide in the sheath portion.

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

Dyeing rate of sheath part: A fixed amount (200 mg) of a dyed composite fiber or a cloth thereof is weighed and immersed in 30 ml of 30% formic acid 88% solution for 3 minutes to form a sheath polyamide. And the dye dyed in it are dissolved, and a colorimeter (Hitachi KK U-3400 "Spectro Ph
otometer ") to measure the absorbance at the maximum absorption wavelength. Also, weigh a fixed amount (200 mg) of the sample before staining,
A predetermined amount (0.25 m) in 30 ml of 88% formic acid solution at 30 ° C
(g, 0.5 mg, or 1.0 mg) of the dye is dissolved, the absorbance is determined by a colorimeter, and the relationship between the absorbance and the dyeing rate in the case of this dye is plotted as a calibration curve. With this calibration curve, the value of the dyeing rate is obtained from the value of the absorbance of the sheath polyamide in the actual dyeing described above.

Dyeing rate of core: First, the sheath polyamide in the composite fiber or its products is dissolved and removed with formic acid, and then washed with water to obtain a dyed fiber component of the core copolyester. A certain amount of the dyed fiber (100
mg) was weighed and put into 30 ml of a phenol / ethane tetrachloride mixed solution (weight ratio 3: 2) and completely dissolved at about 60 ° C., and then the absorbance at the maximum absorption wavelength was measured by the same colorimeter as above. To do. Further, using the copolyester fiber taken out from the sample before dyeing, similarly to the above, to obtain a calibration curve showing the relationship between the absorbance and the dyeing rate, from this calibration curve, the core part in the actual dyeing The dyeing rate of the copolyester is determined.

From the values of the dye dyeing amount of the sheath portion and the core portion (a% owf and b% owf, respectively,)
The dyeing ratio of the sheath to the core is calculated by the formula (a / b) × 100.

The core-sheath type composite fiber of the present invention can be produced by the following method.

First, a predetermined amount of sodium 5-sulfoisophthalate is added to and mixed with a copolyester obtained by copolymerizing a predetermined amount of a sulfonated aromatic dicarboxylic acid by a conventional method. As a method for adding and mixing the same, a predetermined amount of sodium 5-sulfoisophthalate powder is added at the time of drying the copolyester and blended by a rotary dryer, or a master prepared by previously adding high-concentration sodium 5-sulfoisophthalate There are a method in which chips are prepared and blended with a copolyester, and a method in which, when the copolyester is fed into an extruder, a powder feeder is used to add sodium 5-sulfoisophthalate from another line. In this way, the copolymerized polyester to which sodium 5-sulfoisophthalate is added and the polyamide are separately melted based on the usual method, and then introduced into the spinning pack section so that the core-sheath structure is obtained by the usual method. A composite stream is formed in and is spun from the nozzle. The spun filament yarn is cooled and oiled, then taken up at a predetermined speed and then wound into a package. Next, the once wound yarn is generally drawn by a draw twister in a usual manner to obtain a drawn yarn having a desired strength and elongation.

In addition, after cooling and refueling, at a high speed of 3000 m / min or more, a high-speed spinning method for obtaining desired fiber performances at once, or after cooling and refueling, drawing is performed at 700 to 5000 m / min, followed by drawing 2500 It may be produced by a direct spinning drawing method in which the heat setting is performed at ˜5500 m / min. According to this method of high-speed spinning or direct spinning and drawing, swelling of the polyamide in the sheath portion can be suppressed, which is preferable from the viewpoint of preventing core-sheath peeling.

The obtained core-sheath type composite fiber is knitted and woven by a usual method and dyed with a cationic dye by a usual method. In addition, other dyes may be used in combination as long as the amount is within a range that does not impair the effects of the present invention.

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

[0033]

EXAMPLES The measuring methods in the following examples are as follows.

Strength: Measured according to JIS L1013.

Coloring property: A multi-light source spectrocolorimeter (manufactured by Suga Test Instruments Co., Ltd.) is used to measure the color under the condition of C light source of 65 °, and the L value is displayed. When the color developability is poor, the color is whitish and the L value is high.

Lightfastness: Measured by the method of JIS L0842.

Washing fastness: Measured by the method of JIS L0844. However, discoloration shall be measured by classifying the degree of discoloration by comparing with the color difference observed between the color charts of the contaminating gray scale.

Anti-frosting property: The sample cloth and nylon taffeta are repeatedly rubbed 10,000 times under a load of 1 Kg, and the degree of discoloration due to the rubbing is judged according to the following criteria. Grade 5: No discoloration is observed. Grade 4: Almost no discoloration. Grade 3; slight whitening is observed. Grade 2: Whitening is observed. Grade 1; severe bleaching.

Example 1 Ethylene glycol and terephthalic acid were polymerized by adding an ordinary polymerization catalyst for polyethylene terephthalate and 5 mol% of sodium sulfoisophthalate to terephthalic acid, and polymerizing at 20 ° C. orthochloro. Copolymerized polyethylene terephthalate (hereinafter abbreviated as copolymerized polyester) chips having an intrinsic viscosity (IV) in phenol of 0.60 were obtained.

On the other hand, using a two-axis extruder,
IV 0.65 homopolyethylene terephthalate chip was kneaded with sodium 5-sulfoisophthalate 3
0% master chip was produced.

A predetermined amount of the copolymerized polyester chips and a predetermined amount of the master chips were dry-blended while being dried by a rotary dryer to obtain blend chips having different contents of sodium 5-sulfoisophthalate.

This blended chip and a polyhexamethylene adipamide (hereinafter referred to as nylon 66) chip having substantially no titanium oxide and a relative viscosity of sulfuric acid of 2.62 are supplied to an extruder type composite spinning machine. , Melt the polymer separately and then add the polymer on the copolyester side to 40
By weight, nylon 66 was weighed at a ratio of 60 parts by weight and introduced into the composite spinning pack part. Then, the blended copolyester forms a composite flow so that the core is nylon 66 and the sheath is nylon 66, and a composite flow is formed, melted and discharged, cooled and oiled by a normal method, drawn at a speed of 1500 m / min, and once wound. Without being drawn, the film was continuously drawn, heat-set with a drawing heat roller (160 ° C.), and wound at 4000 m / min to obtain a drawn yarn of 70 denier 24 filaments (levels 2 to 6).

For comparison, a drawn yarn (level 1) was obtained by carrying out the same yarn production using only the above-mentioned copolyester as a core. The strength of the obtained drawn yarn was measured and shown in Table 1.

Further, a plain woven fabric was woven using each of the obtained drawn yarns, and scouring and intermediate setting were carried out in the same manner as in the case of a normal polyester fabric to obtain a sample fabric for dyeing.

The sample cloth thus obtained was treated with the cationic dye "Cath.
ilon Blue SG-DP "(Hodogaya Chemical Co., Ltd.) 1.0
% Owf, 0.5 cc / l of acetic acid (80%) as an auxiliary agent were dyed at 105 ° C. for 45 minutes.

Coloring property, light fastness of the obtained dyed fabric,
The wash fastness and anti-frosting property were evaluated. The results are shown in Table 1.

All of the levels had sufficient color development, light fastness and washing fastness, but Level 1 without addition of 5-sulfoisophthalic acid had frosting properties and could not be put to practical use. there were. Further, in Level 6, which was added as much as 6% by weight, the drawn yarn strength could not reach 3 g / d, and again the physical properties in practical use could not be satisfied.

[0048]

[Table 1]

Example 2 The copolymerization rate of sodium 5-sulfoisophthalate was 0.5, 1.0, 1.5, 5.
A copolyester was polymerized in the same manner as in Example 1 except that the content was changed to 0, 8.0, 10.0, 12.0 mol%. Each of the obtained copolymerized polyesters was blended with the master chip of Example 1 to obtain a blended chip containing 1.0% by weight of sodium 5-sulfoisophthalate.

Yarn, weaving and dyeing were carried out in the same manner as in Example 1 except that the obtained blended chip was used as the core. In the case of a copolyester having a copolymerization rate of 5.0 mol%,
The core ratio was changed to 20, 40, 60 and 80%, and the yarn was made, woven and dyed.

The same evaluation as in Example 1 was performed. The results are shown in Table 2.

When the core ratio was 40% and the copolymerization ratio was 0.5 mol%, which was too low, the level 7 was insufficient in color development. On the other hand, when the copolymerization rate was 12 mol%, which was too high, the level of 17 was too low for practical use.

Further, the core ratio is 40% and the copolymerization ratio is 1.
0, 1.5, 5.0, 8.0, 10.0 levels 8, 9,
Nos. 12, 15, and 16 all had sufficient color development, light fastness, and washing fastness, and were sufficiently practical in terms of anti-frosting.

Among the levels having a copolymerization ratio of 5.0 mol% and a changed core ratio, those having a core ratio of 15% have low color development, and those having a core ratio of 80% have low strength and anti-frosting property. , Was unsatisfactory in practice.

[0055]

[Table 2]

[0056]

According to the present invention, since the polymer (sulfonated aromatic dicarboxylic acid copolymerized polyester) forming the core contains a specific amount of sodium 5-sulfoisophthalate, the core is made of polyamide. The adhesiveness is improved, the peeling resistance of the core-sheath during processing and use is significantly improved, and the durability is improved.

As a result, the core-sheath type composite fiber of the present invention is excellent in color development, light resistance, washing resistance, and abrasion resistance, and is strong and has good resin processability. It is possible to have durability that can withstand, and it is possible to greatly suppress deterioration of color development and fibrillation of the sheath during use.

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Claims (7)

[Claims] 1. A polyamide comprising a sheath and a copolymerized polyester obtained by copolymerizing 1.0 mol% or more and 10 mol% or less of a sulfonated aromatic dicarboxylic acid in a core, wherein the ratio of the core is 20. A core-sheath type composite fiber having a weight percentage of 60% by weight or more and a sodium-sulfoisophthalate sodium content of 0.1% by weight or more and 5% by weight or less in the core portion. fiber. 2. The core-sheath type composite fiber according to claim 1, wherein the polyamide of the sheath portion is an aliphatic polyamide having 80% or more of hexamethylene adipamide units. 3. The core-sheath type composite fiber according to claim 1, wherein the content of the matting agent in the polyamide of the sheath is 0 to 0.1% by weight. 4. A copolymerized polyester obtained by copolymerizing a polyamide and a sulfonated aromatic dicarboxylic acid in an amount of 1.0 mol% or more and 10 mol% or less, and 0.1% by weight or more and 5% by weight of sodium 5-sulfoisophthalate. The copolymerized polyester composition blended below is separately melted, and then composite-spun into a core-sheath, and the ratio of the core portion is 20% by weight or more 60
A method for producing a core-sheath type composite fiber, which comprises producing a core-sheath type composite fiber in an amount of not more than 10% by weight. 5. A melt-spun core-sheath type composite fiber
By a high-speed spinning method that draws at 000 m / min or more, or
3000 to 3000 after the collection at 700 to 5000 m / min
The method for producing a core-sheath type composite fiber according to claim 4, wherein the fiber is produced by a direct spinning and drawing method in which the fiber is drawn and heat-set at a rate of 5500 m / min. 6. A dyed conjugate fiber obtained by dyeing the core-sheath type conjugate fiber according to claim 1, wherein substantially only a cationic dye is dyed as a dye. 7. The dyeing composite according to claim 6, wherein the dyeing rate of the sheath is 10% or less and 0.2% owf or less of the dyeing rate of the core. fiber.