JP2019196570A - Hygroscopic exothermic acryl fiber, hygroscopic exothermic fiber product, and method for producing the same - Google Patents

Abstract

To provide a hygroscopic exothermic acryl fiber that has an excellent hygroscopic exothermic ability and has no stickiness feeling.SOLUTION: A hygroscopic exothermic acryl fiber is produced, wherein, when immersing an acryl fiber in an aqueous solution containing an alkali compound and a quaternary ammonium salt and is changed from the condition of temperature 20°C and relative humidity 40% to the condition of temperature 20°C and relative humidity 90%, a temperature rise ΔT of the fiber surface is 2°C or more.SELECTED DRAWING: None

Description

  The present invention relates to a hygroscopic exothermic acrylic fiber, a hygroscopic exothermic fiber processed product, a method of manufacturing a hygroscopic exothermic acrylic fiber, and a method of manufacturing a hygroscopic exothermic fiber processed product.

  Acrylic fiber produced from acrylonitrile copolymer as raw material has excellent features such as soft texture, heat retention, form stability, weather resistance, dyeability, and synthetic fibers such as nylon fiber and polyester fiber. Similarly, it is used in various fields such as clothing and interior.

Natural fibers such as cotton and wool are not only excellent in antistatic and sweat-absorbing properties, but also have a hygroscopic heat-generating performance that generates heat using the heat of adsorption when absorbing moisture in sweat and air. .
Attempts to impart such hygroscopic heat generation performance to synthetic fibers such as nylon, polyester, acrylic, etc. have been made for a long time, and most rely on the introduction of hydrophilic functional groups such as carboxy groups. For acrylic fibers, a method of introducing carboxy groups by hydrolyzing the nitrile groups in the side chain of acrylonitrile copolymer in an alkaline aqueous solution is known, and high hygroscopicity is obtained in proportion to the amount of carboxy groups to be introduced. However, not only does the water swellability become extremely high and a sticky feeling is produced, but also the physical properties of the fiber, particularly the strength, are significantly reduced.

In order to suppress such remarkable water swellability and fiber strength reduction, Patent Documents 1 to 3 propose that a hydrolysis treatment in an alkaline aqueous solution and a crosslinking treatment with hydrazine or the like are used in combination.
However, hydrazine has a strong reducing power and is difficult to handle. The higher the alkali concentration in the alkaline aqueous solution, the better the hygroscopic heat generation performance, but it is necessary to neutralize the high-concentration alkaline aqueous solution used for the treatment and then drain it. Unless a large amount of expensive acidic aqueous solution is used The cost becomes higher.

JP-A-54-42493 Japanese Patent Laid-Open No. 2-91271 JP-A-5-132858

  An object of the present invention is to provide a moisture-absorbing exothermic acrylic fiber, a moisture-absorbing exothermic fiber processed product, and a method for producing these, which do not use hydrazine and have excellent moisture-absorbing heat generation performance and no stickiness.

[1] A moisture-absorbing exothermic acrylic fiber having a fiber surface rising temperature ΔT of 2 ° C. or higher when the temperature is changed from 20 ° C. and relative humidity 40% to 20 ° C. and relative humidity 90%.
[2] A moisture-absorbing and exothermic fiber processed product, wherein the moisture-absorbing and exothermic acrylic fiber content of [1] is 20% by mass or more.
[3] The moisture-absorbing exothermic fiber processed product according to [2], wherein the temperature rise ΔT of the surface when the temperature is changed from 20 ° C. and 40% relative humidity to 20 ° C. and 90% relative humidity is 2 ° C. or higher.
[4] The moisture-absorbing exothermic fiber processed product according to [2] or [3], containing 10 to 80% by mass of one or more selected from the group consisting of cellulosic fibers, animal hair fibers and natural fibers.
[5] The moisture-absorbing exothermic fiber processed product according to any one of [2] to [4], which is a spun yarn or a woven or knitted fabric.

[6] A method for producing a hygroscopic exothermic acrylic fiber according to [1], wherein the acrylic fiber is immersed in an aqueous solution containing an alkali compound and a quaternary ammonium salt.
[7] A method for producing hygroscopic exothermic acrylic fibers, wherein the acrylic fibers are immersed in an aqueous solution containing 1 to 5 g / L of an alkali compound and 0.7 to 10 g / L of a quaternary ammonium salt.
[8] The method for producing a hygroscopic exothermic acrylic fiber according to [6] or [7], wherein the temperature of the aqueous solution is 50 to 120 ° C.
[9] The method for producing a hygroscopic exothermic acrylic fiber according to any one of [6] to [8], wherein the immersion time is 10 to 90 minutes.

[10] A processed fiber product containing acrylic fibers was immersed in an aqueous solution containing an alkali compound and a quaternary ammonium salt to change the temperature from 20 ° C. and a relative humidity of 40% to a temperature of 20 ° C. and a relative humidity of 90%. A method for producing a moisture-absorbing and exothermic fiber processed product, which obtains a moisture-absorbing and exothermic fiber processed product having a rising surface temperature ΔT of 2 ° C. or higher.
[11] A method for producing a moisture-absorbing exothermic fiber processed product, wherein a fiber processed product containing acrylic fibers is immersed in an aqueous solution containing 1 to 5 g / L of an alkali compound and 0.7 to 10 g / L of a quaternary ammonium salt.
[12] The method for producing a moisture-absorbing exothermic fiber processed product according to [10] or [11], wherein the temperature of the aqueous solution is 50 to 120 ° C.
[13] The method for producing a moisture-absorbing and exothermic fiber processed product according to any one of [10] to [12], wherein the immersion time is 10 to 90 minutes.
[14] The method for producing a hygroscopic exothermic fiber processed product according to any one of [10] to [13], wherein the fiber processed product is a spun yarn or a woven or knitted fabric.

  ADVANTAGE OF THE INVENTION According to this invention, the hygroscopic exothermic acrylic fiber which is excellent in moisture absorption heat_generation | fever performance without using a hydrazine, and does not have a sticky feeling, a moisture absorption heat generation fiber processed goods, and these manufacturing methods can be provided.

Hereinafter, the present invention will be described in detail.
The rising temperature ΔT of the hygroscopic exothermic acrylic fiber or the hygroscopic exothermic fiber processed product in the present invention is a value measured by the following method.
In a 20 ° C. atmosphere, the relative humidity near the sample of the hygroscopic exothermic acrylic fiber or hygroscopic exothermic fiber processed product is increased from 40% to 90%, the change in the temperature of the sample surface over time is measured, and the maximum value is obtained. The difference between the sample surface temperature (initial value) at the relative humidity of 40% and the maximum value is defined as the rising temperature ΔT. Specifically, it is measured by a method based on ISO18782 “Fiber—Measurement of Dynamic Moisture Absorption and Heat Generation”.

The hygroscopic exothermic acrylic fiber of the present invention has a fiber surface rising temperature ΔT of 2 ° C. or more when the temperature is changed from 20 ° C. and relative humidity 40% to 20 ° C. and relative humidity 90%.
When the rising temperature ΔT is 2 ° C. or more, when used for clothing, bedding, etc., it is possible to feel sufficient warmth by absorbing moisture such as sweat and generating heat.
In this respect, the rising temperature ΔT is preferably 2.5 ° C. or higher, and more preferably 3 ° C. or higher.

The hygroscopic exothermic fiber processed product of the present invention contains 20% by mass or more of the hygroscopic exothermic acrylic fiber. Examples of the hygroscopic exothermic fiber processed product include spun yarn and woven / knitted fabric.
If the content of the hygroscopic exothermic acrylic fiber is 20% by mass or more, the temperature rise ΔT on the surface of the fiber processed product when the temperature is changed from 20 ° C. and relative humidity 40% to 20 ° C. and relative humidity 90% is 2 It tends to be over ℃.
In this respect, the content of the hygroscopic exothermic acrylic fiber is preferably 40% by mass or more, and more preferably 60% by mass or more. It may be 100% by mass.

It is preferred that the moisture-absorbing exothermic fiber processed product has a temperature rise ΔT of 2 ° C. or more when the temperature is changed from 20 ° C. and relative humidity 40% to temperature 20 ° C. and relative humidity 90%.
When the rising temperature ΔT is 2 ° C. or more, when used for clothing, bedding, etc., it is possible to feel sufficient warmth by absorbing moisture such as sweat and generating heat.
In this respect, the temperature increase ΔT of the moisture-absorbing exothermic fiber processed product is preferably 2.5 ° C. or higher, more preferably 3 ° C. or higher.

The moisture-absorbing exothermic fiber processed product preferably contains 10 to 80% by mass of at least one selected from the group consisting of cellulosic fibers, animal hair fibers and natural fibers. Examples of natural fibers include cotton, wool, silk and the like.
When the total content of cellulosic fibers, animal hair fibers and natural fibers is 10% by mass or more, the texture can be easily improved. In addition, when the temperature is changed from 20 ° C. and a relative humidity of 40% to a temperature of 20 ° C. and a relative humidity of 90%, the rising temperature of the surface of the moisture-absorbing exothermic fiber processed product tends to increase. When the content is 80% by mass or less, the heat retaining effect by the acrylic fiber is easily obtained.
From this viewpoint, the total content of cellulosic fibers, animal hair fibers and natural fibers is preferably 15 to 50% by mass, and more preferably 20 to 30% by mass.

The hygroscopic exothermic fiber processed product may contain chemical fibers other than the hygroscopic exothermic acrylic fiber. Examples of the chemical fiber include acrylic fibers other than hygroscopic exothermic acrylic fibers, polyester fibers, nylon fibers, and rayon fibers.
Examples of acrylic fibers other than the hygroscopic exothermic acrylic fibers include acrylic fibers having anti-pill properties, and acrylic fibers having fineness.
When the hygroscopic exothermic fiber processed product contains chemical fibers other than the hygroscopic exothermic acrylic fiber, the content is preferably 1 to 60% by mass, and more preferably 5 to 40% by mass.

The hygroscopic exothermic acrylic fiber can be produced by immersing the acrylic fiber in an aqueous solution containing an alkali compound and a quaternary ammonium salt (hereinafter also referred to as a treatment aqueous solution).
Since the treatment aqueous solution contains an alkali compound and a quaternary ammonium salt at the same time, moisture absorption heat generation acrylic fibers having sufficient moisture absorption heat generation performance can be obtained even when the concentration of the alkali compound is low, so the load of waste water treatment is reduced. .
Examples of the alkali compound include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, aqueous ammonia, and sodium hydrogen carbonate. Sodium hydroxide is preferred because it is often used industrially and is easy to obtain and handle.
Examples of the quaternary ammonium salt include benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetylpyridinium chloride, cetrimonium, dophanium chloride, tetraethylammonium bromide, didecyldimethylammonium chloride, and domifene bromide.

The moisture-absorbing exothermic fiber processed product is produced by immersing the acrylic fiber in the treatment aqueous solution to produce a hygroscopic exothermic acrylic fiber, and the resulting hygroscopic exothermic acrylic fiber is used to produce a fiber processed product such as spun yarn or woven or knitted fabric. It can be manufactured by the method.
Or it can manufacture also by the method of immersing fiber processed goods, such as a spun yarn or a woven / knitted fabric manufactured using acrylic fiber, in the said process aqueous solution. It is preferable to use a fiber processed product before dipping in the treatment aqueous solution because the workability during dipping is likely to improve.

  The concentration of the alkali compound in the treatment aqueous solution is preferably 1 to 5 g / L. When it is 1 g / L or more, the reaction of the nitrile group in the side chain of the acrylonitrile copolymer constituting the acrylic fiber proceeds sufficiently, and good moisture absorption heat generation performance is easily obtained. When it is 5 g / L or less, the burden of waste liquid treatment tends to be reduced. The concentration of the alkali compound is more preferably 1 to 4 g / L, and still more preferably 1.2 to 3.5 g / L.

The concentration of the quaternary ammonium salt in the treatment aqueous solution is preferably 0.7 to 10 g / L.
When the concentration of the quaternary ammonium salt is 0.7 g / L or more, the reaction of the nitrile group in the side chain of the acrylonitrile copolymer constituting the acrylic fiber is sufficiently facilitated, and good moisture absorption and heat generation performance is easily obtained. . On the other hand, when the concentration of the quaternary ammonium salt is 10 g / L or less, good hygroscopic heat generation performance is easily obtained at low cost. From the above viewpoint, the concentration of the quaternary ammonium salt is more preferably 1 to 8 g / L, and further preferably 1.2 to 7 g / L.

Alcohol may be added to the treatment aqueous solution as long as the object of the present invention is not impaired. Although alcohol is not specifically limited, For example, lower alcohols, such as ethanol, methanol, 2-propanol, ethylene glycol, and glycerol, higher alcohols, such as capryl alcohol and stearyl alcohol, and mixtures thereof can be added. Alcohol may be used individually by 1 type and may use 2 or more types together.
When the treatment aqueous solution contains alcohol, the content thereof is preferably 1 to 20% by mass, and more preferably 5 to 15% by mass with respect to the total mass of the treatment aqueous solution.

  As for the temperature of the process aqueous solution at the time of immersing the said acrylic fiber or the said fiber processed goods, 50-120 degreeC is preferable. If the temperature of the aqueous treatment solution is 50 ° C. or higher, a good reaction rate can be easily obtained. If it is 120 degrees C or less, it will be easy to reduce the energy cost which a process requires, and it will be easy to prevent the stickiness of a hygroscopic heat generation acrylic fiber. The temperature of the treatment aqueous solution is more preferably 60 to 110 ° C, and further preferably 70 to 100 ° C.

  The time for immersing the acrylic fiber or the processed fiber product in the treatment aqueous solution is preferably 10 to 90 minutes. If the immersion time is 10 minutes or longer, the reaction is likely to proceed sufficiently, and good hygroscopic heat generation performance is easily obtained. On the other hand, if the immersion time is 90 minutes or less, the productivity is sufficiently high. The immersion time is more preferably 15 to 80 minutes, and further preferably 20 to 70 minutes.

As a method for producing an acrylic fiber using an acrylonitrile copolymer as a raw material, a wet spinning method, a dry wet spinning method, or a dry spinning method can be used. The wet spinning method is desirable in terms of productivity and cost.
The acrylonitrile copolymer preferably contains 92 to 98% by mass of acrylonitrile units and 2 to 8% by mass of vinyl monomer units with respect to all structural units. If the acrylonitrile unit is 92% by mass or more, the original properties of the acrylic are easily maintained, and if it is 98% by mass or less, it is preferable from the viewpoint of dissolution stability. If the vinyl monomer unit is 2% by mass or more, it is preferable from the viewpoint of dissolution stability, and if it is 8% by mass or less, the original properties of acrylic are easily retained.
The total of the acrylonitrile unit and the vinyl monomer unit is preferably 95% by mass or more, and more preferably 100% by mass with respect to all the structural units of the acrylonitrile copolymer.

  The vinyl monomer is not particularly limited as long as it can be copolymerized with acrylonitrile. Examples of vinyl monomers include methyl acrylate, methyl methacrylate, or esters thereof ((meth) acrylic esters), vinyl acetate, styrene, acrylic amide, 2-hydroxyethyl methacrylate, glycidyl methacrylate, sulfonic acid And group-containing vinyl monomers. Examples of sulfonic acid group-containing vinyl monomers include allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, isoprene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, their metal salts, and amine salts. Can be mentioned. The polymerization method for obtaining the acrylonitrile copolymer is preferably a suspension polymerization method (aqueous suspension polymerization method) carried out in an aqueous medium.

In the wet spinning method, an acrylonitrile copolymer is dissolved in an organic solvent to form a spinning dope. The content of acrylonitrile copolymer in the spinning dope (hereinafter also referred to as copolymer concentration) is preferably 15 to 30% by mass. If the copolymer concentration is 15% by mass or more, good productivity is easily obtained, and if it is 30% by mass or less, yarn breakage is easily prevented, which is preferable from the viewpoint of spinning stability. The copolymer concentration is more preferably 18 to 25% by mass.
As the organic solvent, dimethylacetamide, dimethylformamide, dimethylsulfoxide and the like are preferable. From the viewpoint of solubility, dimethylacetamide is more preferable.

The temperature (dissolution temperature) of the organic solvent when the acrylonitrile copolymer is dissolved in the organic solvent is preferably 40 ° C. or higher and 95 ° C. or lower. When the melting temperature is 40 ° C. or higher, it is preferable in that the amount of undissolved material is small, the use period of the filter medium in the filter equipment such as a filter press can be extended, and the spinnability is not impaired. A melting temperature of 95 ° C. or lower is preferable in that the copolymer is hardly discolored.
The temperature of the spinning dope after dissolving the acrylonitrile copolymer in an organic solvent is preferably 40 ° C. or higher and 95 ° C. or lower. When the temperature of the spinning dope is 40 ° C. or higher, nozzle pressurization due to low viscosity is unlikely to occur, and when it is 95 ° C. or less, gelation of the spinning dope hardly occurs and spinnability is favorable.

Next, the spinning dope is discharged from a plurality of discharge holes to a coagulation bath to obtain a coagulated fiber bundle. The solvent concentration of the coagulation bath is preferably 40% by mass or more and 60% by mass or less. When the solvent concentration is 40% by mass or more, the coagulation rate becomes slow and uniform fibers are easily obtained. When the solvent concentration is 60% by mass or less, the coagulation rate is sufficiently high, and a tension is easily applied stably to the fiber bundle in the coagulation bath, and yarn breakage hardly occurs.
The temperature of the coagulation bath is preferably 35 ° C. or more and 50 ° C. or less. When the coagulation bath temperature is 35 ° C. or higher, the coagulation rate is sufficiently high, tension is easily applied stably to the fiber bundle in the coagulation bath, and yarn breakage hardly occurs. When the coagulation bath temperature is 50 ° C. or less, the coagulation rate becomes slow and uniform fibers are easily obtained.

  The jet stretch when discharging from the discharge hole to the coagulation bath is preferably 0.3 or more and 2.2 or less. The jet stretch is a value obtained by dividing the take-up speed of the coagulated yarn by the discharge linear speed. When the jet stretch is 0.3 or more, tension is easily applied to the fiber bundle in the coagulation bath, and yarn breakage hardly occurs. If the jet stretch is 2.2 or less, it is difficult to apply excessive tension, so that yarn breakage does not easily occur in the spinning bath, which is preferable in terms of good spinnability. From the viewpoint, the jet stretch is more preferably 0.4 or more and 2.0 or less.

Furthermore, the coagulated fiber bundle is preferably stretched in hot water at a stretch ratio of 2 to 6 times.
Furthermore, it is preferable to make an oil agent adhere and to dry. As the oil agent, a known oil agent composition can be used in the production of acrylic fibers. For drying, a method of contacting with a heating roll is preferable in terms of thermal efficiency. The temperature of the heating roll is preferably 100 to 200 ° C.
Furthermore, dry heat stretching may be performed. The draw ratio in dry heat drawing is preferably more than 1 time and 3 times or less. Moreover, when performing dry-heat extending | stretching, it is preferable that the product S of the draw ratio in the said hot water and the draw ratio in the said dry-heat stretching is 2 times or more and 6 times or less.
If the draw ratio in dry heat drawing is more than 1 time, the concave portion of the fiber surface is extended, the smooth surface is increased, and the glossiness is improved. If it is 3 times or less, yarn breakage due to spinning hardly occurs. From the viewpoint of reducing the number of concave portions on the fiber surface and improving the glossiness, the draw ratio with dry heat is more preferably 1.2 or more, and even more preferably 1.7 or more. Moreover, 2 times or less is more preferable from the point of process passability.
Further, when the product S is 2 times or more and 6 times or less, the passing property such as spinning is good, and an appropriate fiber strength is easily obtained. The product S is more preferably 4.5 times or more and 5.5 times or less.

The temperature of hot water when stretching in the hot water is preferably 80 ° C. or higher and 98 ° C. or lower. If it is this range, it will be hard to produce a cutting | disconnection of a fiber at the time of extending | stretching in hot water.
Moreover, the fiber temperature at the time of extending | stretching with dry heat has preferable 150 to 170 degreeC. If the temperature is 150 ° C. or higher, the wrinkles on the fiber surface can be easily stretched. If the temperature is 170 ° C. or lower, discoloration due to heat hardly occurs, and the fiber is hardly cut during stretching with dry heat.

Examples of means for heating the fiber bundle during dry heat drawing include contact heating with a heating roll, a hot plate, and non-contact heating with hot air. Especially, a heating roll is preferable at the point which can heat efficiently.
When heating with a heating roll, the temperature of the heating roll and the time during which the fiber bundle contacts the heating roll may be set as appropriate. It is preferable to heat both sides of the fiber bundle through a plurality of heating rolls.
The temperature of the heating roll is preferably 150 ° C. or higher and 190 ° C. or lower. If the said temperature is 150 degreeC or more, it will become easy to extend the wrinkle on the fiber surface, and if it is 190 degreeC or less, the discoloration by the heat | fever of a fiber will not arise easily.

Furthermore, you may give crimp by a well-known method.
Furthermore, you may perform a heat relaxation process so that the thermal contraction rate of a fiber may be 5% or more and 20% or less. The heat shrinkage rate is a ratio of shrinkage of the fiber bundle before and after the heat relaxation treatment.
The thermal relaxation condition is defined by the thermal shrinkage rate of the fiber. For example, the heat shrinkage of the fiber is preferably 5% or more and 20% or less from the viewpoint of form stability.
The temperature for heat relaxation is preferably 120 ° C. or higher and 135 ° C. or lower. If the said temperature is 120 degreeC or more, the single fiber strength and single fiber elongation with favorable card | curd permeability at the time of spinning will be easy to be obtained. If it is 135 degrees C or less, it is preferable at the point of intensity | strength maintenance.

  The fiber bundle obtained by the above manufacturing method is cut with a cutter to make short fibers, and then spun to obtain a spun yarn. The length of the short fiber is preferably 10 to 200 mm. A spun yarn may be blended with fibers other than acrylic fibers.

Thereafter, if necessary, a woven or knitted fabric is obtained through a twisting process, a dyeing process, and a weaving / knitting process.
The step of immersing the acrylic fiber or fiber processed product (spun yarn, woven or knitted fabric) in the treatment aqueous solution may be performed during the spinning step, spinning step, twisting step, dyeing step, weaving / knitting step, and between the steps. You may go.

In general, acrylic fibers are immersed in an alkaline aqueous solution, whereby the nitrile groups in the side chains of the acrylonitrile copolymer constituting the acrylic fibers are hydrolyzed to introduce carboxyl groups. However, conversion to a carboxyl group requires a high-concentration aqueous alkali solution. Usually, conversion of a nitrile group to a carboxy group does not proceed even when acrylic fibers are immersed in a low-concentration aqueous alkali solution. When the acrylic fiber is dipped in an aqueous alkaline solution having a high concentration, the water swellability of the modified fiber is remarkably increased, resulting in not only a sticky feeling but also a significant decrease in fiber properties, particularly strength.
However, as a result of intensive studies by the present inventors, surprisingly, the presence of a quaternary ammonium salt in the treatment aqueous solution can provide a hygroscopic exothermic acrylic fiber even when the concentration of the alkali compound in the treatment aqueous solution is low. As a result, the present invention has been achieved. Although the detailed reason is not clear, the quaternary ammonium salt is a compound having surface active performance, and has an effect of improving the affinity between the acrylic fiber and the alkali compound. By adding a quaternary ammonium salt, it is presumed that the hygroscopic heat generation performance of the acrylic fiber is improved.

Although the hygroscopic exothermic acrylic fiber of this invention is demonstrated based on a following example, this invention is not limited to a following example at all.
<Measurement method of rising temperature ΔT>
The temperature rise ΔT of the moisture-absorbing exothermic fiber processed product was measured by the following method in accordance with ISO18782 “Fiber-Measurement of Dynamic Hygroscopic Exothermic Heat Generation”.
In an atmosphere at a temperature of 20 ° C. and a relative humidity of 40%, water vapor is supplied to one surface (humidified surface) of the sample, and the relative humidity in the vicinity of the humidified surface is rapidly humidified from 40% to 90%. The temperature change of was measured over time. The temperature change of the humidified surface is measured until 30 minutes after the supply of water vapor to the humidified surface, and the difference between the maximum temperature reached during this time and the temperature before the start of supply of water vapor is measured as the rising temperature ΔT (° C. ).

(Example 1)
An acrylonitrile copolymer comprising 93% by mass of acrylonitrile and 7% by mass of vinyl acetate was obtained by an aqueous suspension polymerization method. Next, the copolymer was dissolved in dimethylacetamide at 80 ° C. to obtain a spinning dope having a copolymer concentration of 25% by mass. The spinning undiluted solution (80 ° C.) was discharged into a coagulation bath (40 ° C.) of 55% by mass of dimethylacetamide and 45% by mass of water using a nozzle provided with a round-shaped discharge hole to perform wet spinning. The nozzle discharge hole diameter was 0.008 mm, and the number of discharge holes was 15,000. The jet stretch at the time of discharging from the discharge hole to the coagulation bath was set to 0.5.
Next, the solvent was washed in hot water at 90 ° C. and then stretched 5 times in the hot water. Subsequently, an oil agent is attached, dried with a heating roll at 150 ° C., cut into a fiber length of 38 mm, and an acrylic fiber having a cross-sectional shape of empty beans (single fiber fineness 1 dtex, fiber length 38 mm, boiling water shrinkage 0 to 2% is obtained. It was.

Next, the obtained acrylic fiber was put into a spinning process, and a 40th spun yarn was produced with a cotton count. The content of acrylic fiber with respect to the spun yarn was 100% by mass. A smooth fabric knitted fabric was prepared from the obtained spun yarn using a 20-gauge 48-port circular knitting machine.
Separately, an aqueous solution of an alkali compound (sodium hydroxide) 3 g / L and a quaternary ammonium salt 4.9 g / L was prepared. The temperature of this aqueous solution was adjusted to 100 ° C., and the acrylic knitted fabric obtained above was immersed for 30 minutes to obtain a moisture-absorbing exothermic fiber processed product. The bath ratio representing the mass ratio of acrylic knitted fabric: aqueous solution was set to 1:23. The temperature rise ΔT of the obtained moisture-absorbing exothermic fiber processed product (smooth structure knitted fabric) was measured by the method described above. The results are shown in Table 1 (hereinafter the same). There was no stickiness on the surface of the moisture-absorbing exothermic fiber processed product.

(Examples 2 to 8)
Except that the alkaline compound concentration and the quaternary ammonium salt concentration in the aqueous solution were changed as shown in Table 1, a moisture-absorbing exothermic fiber processed product was produced in the same manner as in Example 1, and the rise temperature ΔT was measured. There was no stickiness.

Example 9
In addition to the alkali compounds and quaternary ammonium salts having the concentrations shown in Table 1, alcohols (ethanol 95.8% by mass, 2-propanol 4.2% by mass) as additives and the alcohol concentration with respect to the aqueous solution to 10% by mass Then, an aqueous solution was prepared. Except for this, a hygroscopic exothermic fiber processed product was produced in the same manner as in Example 1, and the temperature increase ΔT was measured. There was no stickiness.

(Comparative Examples 1-5)
Except that the alkaline compound concentration and the quaternary ammonium salt concentration in the aqueous solution were changed as shown in Table 1, a moisture-absorbing exothermic fiber processed product was produced in the same manner as in Example 1, and the rise temperature ΔT was measured. There was no stickiness.

As shown in the results of Table 1, the hygroscopic exothermic fiber processed products of Examples 1 to 9 (hygroscopic exothermic acrylic fiber 100%) were excellent in hygroscopic exothermic performance and had no sticky feeling.
The hygroscopic exothermic fiber processed products of Comparative Examples 1 to 5 were inferior in hygroscopic exothermic performance.

Claims (14)

  A moisture-absorbing exothermic acrylic fiber having a fiber surface rising temperature ΔT of 2 ° C. or higher when the temperature is changed from 20 ° C. and a relative humidity of 40% to a temperature of 20 ° C. and a relative humidity of 90%.   A moisture-absorbing exothermic fiber processed product, wherein the content of the hygroscopic exothermic acrylic fiber according to claim 1 is 20% by mass or more.   The moisture-absorbing exothermic fiber processed product according to claim 2, wherein the surface rising temperature ΔT when the temperature is changed from 20 ° C and 40% relative humidity to 20 ° C and 90% relative humidity is 2 ° C or more.   The moisture-absorbing exothermic fiber processed product according to claim 2 or 3, containing 10 to 80% by mass of one or more selected from the group consisting of cellulosic fibers, animal hair fibers and natural fibers.   The hygroscopic exothermic fiber processed product according to any one of claims 2 to 4, which is a spun yarn or a woven or knitted fabric.   A method for producing a hygroscopic exothermic acrylic fiber according to claim 1, wherein the acrylic fiber is immersed in an aqueous solution containing an alkali compound and a quaternary ammonium salt.   A method for producing hygroscopic exothermic acrylic fibers, wherein the acrylic fibers are immersed in an aqueous solution containing 1 to 5 g / L of an alkali compound and 0.7 to 10 g / L of a quaternary ammonium salt.   The manufacturing method of the hygroscopic exothermic acrylic fiber of Claim 6 or 7 whose temperature of the said aqueous solution is 50-120 degreeC.   The method for producing hygroscopic exothermic acrylic fibers according to any one of claims 6 to 8, wherein the immersion time is 10 to 90 minutes.   Surface when a fiber processed product containing acrylic fibers is immersed in an aqueous solution containing an alkali compound and a quaternary ammonium salt and the temperature is changed from 20 ° C. and 40% relative humidity to 20 ° C. and 90% relative humidity. A method for producing a moisture-absorbing and exothermic fiber processed product, which obtains a moisture-absorbing and exothermic fiber processed product having a temperature rise ΔT of 2 ° C. or higher.   A method for producing a moisture-absorbing and exothermic fiber processed product, wherein a fiber processed product containing acrylic fibers is immersed in an aqueous solution containing 1 to 5 g / L of an alkali compound and 0.7 to 10 g / L of a quaternary ammonium salt.   The method for producing a moisture-absorbing exothermic fiber processed product according to claim 10 or 11, wherein the temperature of the aqueous solution is 50 to 120 ° C.   The manufacturing method of the hygroscopic exothermic fiber processed product according to any one of claims 10 to 12, wherein the immersion time is 10 to 90 minutes.   The method for producing a moisture-absorbing and exothermic fiber processed product according to any one of claims 10 to 13, wherein the fiber processed product is a spun yarn or a woven or knitted fabric.