KR20170005180A - Glossy pilling-resistant acrylic fiber, method for producing same, and spun yarn and knitted fabric including said acrylic fiber - Google Patents

Abstract

The present invention provides an acrylic fiber of 0.5 to 3.5 dtex excellent in glossiness, peelability and feel, and a method of producing the same and a spinning yarn and a letter containing the acrylic fiber. The acrylic fiber having a short fiber fineness of 0.5 to 3.5 dtex and a product K of a value of a nodule strength (cN / dtex) and a value of a nodule elongation (%) of 8 or more and 30 or less and 10 or less recesses having a depth of 0.1 탆 or more is obtained. A method for producing the same is an acrylonitrile copolymer containing 92 to 96.8% by mass of acrylonitrile units, 2 to 6% by mass of vinyl monomer units and 0.2 to 2.0% by mass of vinyl monomer units containing sulfonic acid groups in an organic solvent To prepare a spinning stock solution. The same spinning liquid is discharged from a discharging hole into a coagulating bath having a solvent concentration of 40 to 60 mass% and a temperature of 35 to 50 占 폚 to obtain a coagulated fiber. The coagulated fiber is drawn in hot water at a draw ratio of 2 to 3.8 times, After the emulsion is applied and dried, it is stretched at a draw ratio of 1.2 to 3 times at dry heat. The product S of the draw ratio in the hot water and the draw ratio in the dry heat is 4 to 6 times and further the heat relaxation treatment is performed.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a gloss-peeling acrylic fiber, a method of producing the same, and a spinning yarn and a letter containing the acrylic fiber. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to an acrylic fiber having excellent gloss, soft feel and peelability, a method for producing the acrylic fiber, and a spinning yarn and a letter (knitted fabric) including the acrylic fiber.

Acrylic fibers have excellent properties such as soft touch, warmth, shape stability, weatherability, and dyeability, and are widely used in medical products and interior fields as well as synthetic fibers such as nylon fibers and polyester fibers. However, the fiber product made of the acrylic fiber has a problem that peeling easily occurs during wearing, and the appearance and feel of the knitted fabric are remarkably impaired and the product value is lowered. BACKGROUND ART In the past, acrylic fibers have been required to be improved in so-called peelability, in which peeling is unlikely to occur.

On the other hand, in recent years, as a means for making the feel of a medical product softer, three fibers have been made finer and product development using three fineness fibers has been carried out. In general, however, , The demand for improvement of the peeling property is further increasing.

Further, in addition to improving the feel of the medical product, there is a proposal for improving the glossiness in order to provide a high quality such as silk. For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 11-222716) discloses a step-like acrylic fiber having a single fiber fineness of 6 to 34 dtex, wherein the fiber cross-section is flat, Or as described in Patent Document 2 (Japanese Unexamined Patent Publication (Kokai) No. 2001-36512), the fiber cross-section has a round or oval outer edge portion close to a circular shape, There is proposed a glossy fiber having a curved portion. All of these fibers were of a stepped fiber having a single fiber fineness of 6 dtex or more, or a cross-section of a flat or bean-bean type.

Patent Document 3 (Japanese Unexamined Patent Application Publication No. 2006-176937) and Patent Document 4 (Japanese Unexamined Patent Application Publication No. 2008-38309) disclose a spinning yarn comprising three-island acrylic fibers with peeling properties and a manufacturing method thereof . However, the three islands did not have both anti-peeling and gloss in the acrylic fiber.

In Patent Document 5 (Japanese Patent Laid-Open Publication No. 2011-12363), there is proposed an acrylic fiber having carbon fiber precursor acrylic fiber with a small irregularity on the surface of the fiber and a monofilament fineness of 1.1 dtex. However, since the strength of the carbon fiber precursor acrylic fiber is increased, the nodule strength and nodule elongation are small. For this reason, the carbon fiber precursor acrylic fiber is not spun yarn because the fibers are often cut off during the spinning process.

Japanese Patent Application Laid-Open No. 11-222716 Japanese Patent Application Laid-Open No. 2012-36512 Japanese Patent Application Laid-Open No. 2006-176937 Japanese Patent Application Laid-Open No. 2008-38309 Japanese Patent Application Laid-Open No. 2011-12363

Accordingly, the present invention provides an acrylic fiber having a glossiness, an anti-peeling property, and a soft feeling and having a durability of not less than 0.5 dtex and not more than 3.5 dtex, a method for producing the acrylic fiber, and a spinning yarn and a letter containing the acrylic fiber.

In the acrylic fiber of the present invention, the center line average roughness (Ra) of the surface of the monofilament is 3 nm or more and 12 nm or less, and the monofilament fineness is 0.5 dtex or more and 3.5 dtex or less.

The acrylic fiber of the present invention preferably has a product K of a value of a nodule strength (cN / dtex) and a value of a nodule elongation (%) of 10 or more and 30 or less.

The acrylic fiber of the present invention is characterized in that the center line average roughness (Ra) of the surface of the short fibers is 3 nm or more and 12 nm or less and the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation to be.

The acrylic fiber of the present invention preferably has a monofilament fineness of 0.5 dtex or more and 3.5 dtex or less.

The acrylic fiber of the present invention is characterized in that the maximum height difference Ry of the surface of the short fibers is 40 nm or more and 150 nm or less, the 30-point average roughness (Rz) is 20 nm or more and 80 nm or less, And is preferably 800 nm or more and 1100 nm or less.

It is preferable that the acrylic fiber of the present invention has 10 or less concave portions having a depth of 0.1 占 퐉 or more on the surface of the short fibers at a cross section in the direction perpendicular to the fiber axis.

The acrylic fiber of the present invention is characterized in that it contains acrylonitrile units of 92 mass% to 96.8 mass%, vinyl monomer units of 2 mass% to 6 mass%, and sulfonic acid group-containing vinyl monomer units of 0.2 mass% to 2.0 mass% Wherein the monofilament has a short fiber tensile strength of 1.8 cN / dtex to 3.0 cN / dtex, a short fiber nodule strength of 1.0 cN / dtex to 1.8 cN / dtex, and a short fiber nodule elongation of 8% to 20% desirable.

The method for producing an acrylic fiber of the present invention is characterized in that an acrylonitrile copolymer containing 92% by mass or more and 96.8% by mass or less of an acrylonitrile unit and 0.2% by mass or more and 2.0% by mass or less of a vinyl monomer unit containing a sulfonic acid group Dissolving it in an organic solvent to prepare a spinning stock solution and discharging the spinning stock solution from a plurality of discharge holes of a spinning nozzle to a coagulating bath having a temperature of 35 ° C to 50 ° C at a jet stretch of 0.4 to 2.2, The coagulated fiber is stretched at a draw ratio of 2 to 3.8 times in hot water at a temperature of not lower than 80 캜 and not higher than 98 캜 and an oil agent is applied and dried, , And the product of the dry heat expansion ratio and the dry heat draw ratio multiplied by 4 or more and 6 or less, Of the method.

The method for producing an acrylic fiber of the present invention is characterized in that the acrylonitrile copolymer further comprises 2 mass% or more and 6 mass% or less of a vinyl monomer unit and the solvent concentration of the coagulating bath is 40 mass% % Or less, and it is preferable to perform heat relaxation treatment after dry heat stretching.

In the method for producing an acrylic fiber of the present invention, it is preferable that the annealing temperature in the thermal relaxation treatment is 120 ° C or more and 135 ° C or less, and the fiber relaxation rate is 5% or more and 20% or less.

The yarn of the present invention contains 40% by mass or more of the acrylic fiber, and the yarn count is 40 or more and 70 or less.

The yarn of the present invention preferably comprises 10% by mass or more and 40% by mass or less of the cellulosic fiber.

The letter of the present invention contains not less than 40 mass% of the yarn, a basis weight of not less than 150 g / m ^{2 and not} more than 230 g / m ² , and a peeling performance of not less than grade 4.

In the letter of the present invention, it is preferable that the keeping rate is 15% or more and 50% or less.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an acrylic fiber capable of obtaining a fiber product having soft feel, gloss with high quality and good peeling property in medical use for inner use such as innerwear.

1 is a cross-sectional view of a short fiber surface, illustrating the center line average roughness (Ra).
Fig. 2 is a sectional view of the short fiber surface, illustrating the maximum height Ry. Fig.
Fig. 3 is a cross-sectional view of the short fiber surface, illustrating the 30 point average roughness (Rz). Fig.
Fig. 4 is a cross-sectional view of the short fiber surface, illustrating the spacing S of local peaks. Fig.

≪ Polymer Composition of Acrylic Fiber >

The copolymer constituting the acrylic fiber of the present invention preferably contains 92% by mass or more and 96.8% by mass or less of acrylonitrile units. When the copolymerization ratio of the acrylonitrile unit is 92 mass% or more, the fiber strength required for the medical fiber is easily obtained.

From this viewpoint, it is more preferable that the copolymerization ratio of the acrylonitrile unit is 95% by mass or more.

If the copolymerization ratio of acrylonitrile units is 96.8 mass% or less, dyeability, fiber strength and elongation are likely to be obtained.

The copolymerization ratio of acrylonitrile and the vinyl monomer unit having a copolymerization is preferably 3.0% by mass or more and 6.0% by mass or less. When the copolymerization ratio of the vinyl monomer unit is within this range, sufficient physical properties and dyeability can be obtained as a letter product.

The copolymer preferably has a copolymerization ratio of the vinyl monomer having a sulfonic acid group of 0.2% by mass or more and 2.0% by mass or less. If the copolymerization ratio of the sulfonic acid group-containing vinyl monomer is 0.2 mass% or more, the dyeability tends to be good. If the copolymerization ratio is 2.0 mass% or less, the increase in cost can be reduced.

Examples of the vinyl-based monomer copolymerizable with acrylonitrile include methyl acrylate, methyl methacrylate, and (meth) acrylate esters thereof, vinyl acetate, styrene, acrylamide, 2-hydroxyethyl methacrylate, glycidyl And dile methacrylate. Examples of the vinyl monomer having a sulfonic acid group include allyl sulfonic acid, methallylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, isoprenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, And amine salts are preferably used, but the present invention is not limited to the monomers mentioned above. The polymerization method for obtaining such an acrylonitrile-based copolymer is preferably a suspension polymerization method which is carried out in an aqueous medium.

<Fineness of finishing of acrylic fiber>

The monofilament fineness of the acrylic fiber of the present invention is preferably 0.5 dtex or more and 3.5 dtex or less. Generally, when the fibers are tapered, the dyeing sharpness tends to be lowered. However, the acrylic fiber of the present invention has dyeing clarity even if it is 1.2 dtex or less. If the monofilament fineness is 0.5 dtex or more, the effect of dyeing clarity tends to appear. If the monofilament fineness is 3.5 dtex or less, a soft feeling tends to be obtained when a letter is used. From these viewpoints, the monofilament fineness is more preferably 0.7 dtex or more and 2.0 dtex or less, and still more preferably 0.8 dtex or more and 1.2 dtex or less.

<Product K>

In the acrylic fiber of the present invention, the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) is preferably 10 or more and 30 or less. The value of this product K is a value used by those skilled in the art as an index of the peelability.

When the product K is 10 or more, generation of ply in which the short fibers are cut finely in the spinning process is reduced, and when it is 30 or less, the peeling resistance is good.

From this viewpoint, the product K is more preferably 12 or more and 25 or less, and still more preferably 14 or more and 20 or less.

<Centerline average roughness (Ra) of short fiber surface>

Since the acrylic fiber of the present invention has few grooves on the fiber surface, it has excellent gloss. In the acrylic fiber of the present invention, the centerline average roughness (Ra) of the surface of the staple fibers is 3 nm or more and 12 nm or less. Ra of 3 nm or more is preferable because friction between the roll and the fiber occurs during spinning to make it difficult to cause slip in the roll, and when Ra is 12 nm or less, gloss is preferably exhibited. From this viewpoint, the Ra is more preferably 4 nm or more and 10 nm or less, and still more preferably 5 nm or more and 9 nm or less.

&Lt; maximum elevation difference Ry, 30 point average roughness Rz, distance between vertices of convex portion S>

The acrylic fiber of the present invention is characterized in that the maximum height difference Ry of the surface of the short fibers is 40 nm or more and 150 nm or less, the 30-point average roughness (Rz) is 20 nm or more and 80 nm or less, And is preferably 800 nm or more and 1100 nm or less.

When the Ry is 40 nm or more, friction is generated between the fibers, which is preferable in view of good processability in the spinning process, and 150 nm or less is preferable in that regular reflection is likely to occur. From this viewpoint, Ry is more preferably 50 nm or more and 100 nm or less, and still more preferably 55 nm or more and 90 nm or less.

When Rz is 20 nm or more, it is preferable from the viewpoint of good passage property at spinning, and when it is 80 nm or less, glossiness is preferably improved. From this viewpoint, Rz is more preferably 30 nm or more and 65 nm or less, and still more preferably 35 nm or more and 50 nm or less.

When S is 800 nm or more, it is preferable from the standpoint of radioactivity, and when it is 1100 nm or less, the number of irregularities on the surface of the fiber is small and irregular reflection hardly occurs. In view of the above, S is more preferably 900 nm or more and 1000 nm or less.

&Lt; Number of recesses on the fiber surface &

It is preferable that the acrylic fiber of the present invention has ten or less concave portions having a depth of 0.1 占 퐉 or more on the surface of the short fibers at a cross section in the direction perpendicular to the fiber axis. The depth of the concave portion is preferably 10 or less when the cross section perpendicular to the fiber axis direction is observed by a method described later and the depth of the fiber surface is 0.1 μm or more. If the fiber surface has a concave portion with a depth of 0.1 탆 or more, diffuse reflection of light occurs. In the acrylic fiber of the present invention, when the number of concave portions of not less than 0.1 mu m is 10 or less in the cross section of the fiber, irregular reflection of light can be reduced and gloss is not easily lowered, and glossiness is easily obtained. From the above viewpoint, the number of concave portions of 0.1 占 퐉 or more is more preferably 5 or less.

In order to reduce the unevenness of the surface of the fiber, it is effective to lower the stretching magnification when stretching the coagulating fiber from wet heat.

The short fiber tensile strength of the acrylic fiber of the present invention is preferably 1.8 cN / dtex or more, more preferably 2.0 cN / dtex or more, from the viewpoint of passing through the processing process such as spinning process. The upper limit value of the tensile strength is not particularly limited, but is preferably 3.0 cN / dtex.

The short fiber nodule strength of the acrylic fiber of the present invention is preferably 1.0 cN / dtex or more and 1.8 cN / dtex or less.

When the nodule strength is 1.0 cN / dtex or more, the generation of ply in the spinning process is reduced and the passing of the process is improved. When the nodule strength is 1.8 cN / dtex or less, the anti-peeling performance is likely to be good . From this viewpoint, the nodule strength is more preferably 1.2 cN / dtex to 1.6 cN / dtex, and more preferably 1.4 cN / dtex to 1.5 cN / dtex.

The monofilament nodular elongation of the acrylic fiber of the present invention is preferably 8% or more and 20% or less, more preferably 15% or less, from the viewpoint of improving the peelability.

&Lt; Process for producing acrylic fiber &

The acrylic fiber of the present invention can be obtained by wet spinning or dry-wet spinning, but wet spinning is preferable in view of productivity and cost.

&Lt; Copolymer composition >

The method for producing an acrylic fiber of the present invention is characterized in that the acrylonitrile unit is contained in an amount of 92 mass% or more to 96.8 mass% or less, 2 mass% or more to 6 mass% or less of the vinyl monomer unit, or 0.2 mass% or less of the vinyl monomer unit containing the sulfonic acid group, By mass or more and 2.0% by mass or less based on the total amount of the copolymer.

The acrylonitrile-based copolymer is dissolved in an organic solvent to obtain a spinning solution.

The spinning liquid preferably comprises an acrylonitrile copolymer in an amount of 15 mass% or more and 30 mass% or less, and an organic solvent in an amount of 70 mass% or more and 85 mass% or less. When the concentration of the acrylonitrile-based copolymer in the spinning stock solution is 15 mass% or more and 30 mass% or less, the spinnability is preferable in view of yarn cutting and productivity. The copolymer concentration is more preferably 18% or more and 25% or less from the viewpoint of radioactivity.

As the organic solvent, it is necessary to use an organic solvent such as dimethylacetamide, dimethylformamide or dimethylsulfoxide. Among them, dimethylacetamide is preferable in terms of productivity in fiber production, dyeing clarity of the obtained peelable acrylic fiber, and balance of anti-peeling performance.

The temperature at which the acrylonitrile-based copolymer is dissolved in the organic solvent is 40 DEG C or more, the amount of unhulled solution is small, the period of use of the filter medium in the filtration equipment such as the filter press can be prolonged, Tearing property) is not damaged. On the other hand, if the above-mentioned dissolution temperature is 95 캜 or lower, it is preferable that the copolymer hardly discolors.

The temperature of the spinning solution after dissolving the acrylonitrile-based copolymer in the organic solvent is preferably 40 캜 or higher and 95 캜 or lower. When the temperature is higher than or equal to 40 ° C and lower than or equal to 95 ° C, the spinnability of the spinning stock solution, the increase in nozzle pressure due to the low viscosity, and the gelation of the spinning solution do not occur.

<Coagulation bath temperature>

Next, the spinning stock solution is discharged from a plurality of discharge holes of the spinning nozzle into a coagulating bath having a solvent concentration of 40 mass% or more and 60 mass% or less and a temperature of 35 占 폚 or more and 50 占 폚 or less.

When the range of the solvent concentration and the temperature is within the above range, the coagulation is not excessively accelerated and the concave wrinkles on the surface of the fiber tend to be reduced.

&Lt; Jet stretch, hot water draw ratio, dry heat draw ratio, draw ratio multiplication >

The jet stretch at the time of discharging from the discharge hole of the spinning nozzle is preferably 0.4 or more and 2.2 or less. The jet stretch is a value obtained by dividing the drawing speed of the coagulation yarn by the discharge linear velocity.

When the jet stretch is 0.4 or more and 2.2 or less, it is preferable that the yarn is cut in a spinning bath and the spinnability is good. From the above viewpoint, the jet stretch is more preferably 0.6 or more and 2.0 or less.

Further, the coagulated fiber is stretched in hot water to a stretching ratio of 2 to 4 times, an emulsion is applied, followed by drying, followed by stretching at a draw ratio of 1.2 times or more and 3 times or less in dry heat, And the drawing magnification at the dry heat is set to 4 times or more and 6 times or less.

When the draw ratio at the dry heat is 1.2 or more, the concave portion of the fiber surface is flattened, so that the smooth surface is increased and the glossiness is improved. If it is 3 times or less, the peeling resistance is favorable and yarn cutting by spinning is reduced.

From the viewpoint of reducing the concave portion of the fiber surface and enhancing the glossiness, the draw ratio in dry heat is more preferably 1.5 or more, and more preferably 1.7 or more. In addition, from the viewpoint of process passability, it is preferably 2 times or less.

If the product S is 4 times or more and 6 times or less, it is preferable from the viewpoint of good passing property such as spinning and having a suitable fiber strength. Also, the anti-peeling performance tends to be good. The product S is more preferably 4.5 to 5.5 times.

&Lt; Hot water temperature, fiber temperature of dry heat elongation >

The temperature of the hot water at the time of stretching in the hot water is preferably 80 deg. C or higher and 98 deg. C or lower. Within this range, it is possible to reduce cutting of the fibers during stretching in hot water.

Further, the fiber temperature at the time of drawing from the dry heat is preferably 150 ° C or more and 170 ° C or less. If the temperature is 150 占 폚 or higher, the wrinkles on the surface of the fiber become easy to open. If the temperature is 170 占 폚 or lower, the discoloration due to heat can be reduced and the cutoff of fibers during drawing in dry heat can be reduced.

Examples of the means for heating the fiber in drawing from the dry heat include contact heating with a heating roll and a hot plate, and non-contact heating with heating with hot air. Among them, a heating roll is preferable as the means for heating the fiber in view of efficient heating.

Further, in the case of heating with a heating roll, the temperature of the heating roll and the time when the inside of the fiber is in contact with the heating roll may be appropriately set. It is preferable to heat the both surfaces of the fiber by passing 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 temperature is 190 占 폚 or lower, discoloration due to heat of the fiber can be reduced.

The dry heat-stretched fiber is crimped and stored in a container.

It is preferable that the swelling degree of the fiber drawn in hot water is in the range of 80% or more and 130% or less. If the degree of swelling is 80% or more and 130% or less, wrinkles on the surface of the fiber tends to be small, because dryness and productivity are good.

&Lt; Heat relaxation treatment >

Lastly, thermal relaxation treatment is carried out so that the heat shrinkage ratio of the fibers is 5% or more and 20% or less to obtain acrylic fiber. The thermal relaxation condition is defined by the heat shrinkage ratio of the fiber, and the heat shrinkage of the fiber is preferably 5% or more and 20% or less in view of the nodule strength and nodule elongation, which maintains the peelability.

The heat shrinkage rate is a rate at which the inside of the fiber shrinks before and after the heat relaxation treatment.

The temperature at which heat relaxation is performed should be 120 ° C or more and 135 ° C or less. When the above pressure is 120 占 폚 or higher, it is preferable from the standpoint of obtaining a monofilament strength and a monofilament elongation with good card passing property at the time of spinning. When the temperature is lower than 135 占 폚, staple fibers having excellent anti- desirable.

The acrylic fiber of the present invention obtained by the above-mentioned production method is cut into a short fiber by a cutter and then spun. The constitution of the yarn is such that the acrylic fiber of the present invention may be 100% or the synthetic fiber such as ordinary acrylic fiber, polyester fiber, nylon fiber, rayon fiber or chemical fiber, cotton, wool, It is also possible to make a spun yarn.

<Fiber composition of spun yarn>

In the yarn of the present invention, it is preferable that the content of the acrylic fiber of the present invention contained in the yarn is 40 mass% or more. When the content is 40 mass% or more, the gloss and the peeling performance of the acrylic fiber of the present invention are liable to appear. From this viewpoint, the content is more preferably 60% by mass or more, and more preferably 80% by mass or more.

<Number of yarn yarns>

In the yarn spinning yarn of the present invention, the yarn yarn number of the yarn is preferably not less than 40 but not more than 70 yarn counts. If the number of yarns is 40 or more, it is easy to soften the fabric by the effect of fine fineness of the acrylic fiber of the present invention. Further, when the number is less than 70, it is easy to obtain the strength required when the yarn is used.

The CV%, which is the yarn unevenness of the yarn, is preferably 11.5 or less. When the CV% is 11.5 or less, the appearance of the letter is clear and the glossiness is improved. The CV% is more preferably 11 or less, and more preferably 10 or less.

&Lt; Mixture ratio of cellulose-based fibers &

In the yarn of the present invention, it is preferable that the content of the cellulose-based fibers is 10% by mass or more and 40% by mass or less. When the content of the cellulose-based fibers is 10 mass% or more, the hygroscopic exothermic property is improved. When the content is 40 mass% or less, the skin peelability and the warmth property are favorable.

<The composition of the letter>

In the letter of the present invention, it is preferable that the content of the yarn is 40 mass% or more. If the content is 40% by mass or more, the glossiness and peeling property of the letter are likely to be obtained. In view of the above, 50 mass% or more is more preferable, and 60 mass% or more is more preferable.

<Basis of the letter>

The letter of the present invention preferably has a basis weight of 150 g / m ² or more and 230 g / m ² or less. When the basis weight is 150 g / m ² or more, the letter strength is difficult to be torn, and when it is 230 g / m ² or less, a light and soft letter can be obtained as an undercoat.

<Portability>

In the letter of the present invention, the anti-peeling performance is preferably 4 or more. If the peelability is grade 4 or higher, the appearance of the letter can be cleaned because there is little curl node. The anti-peeling performance is more preferably 4.5 or more.

<Warmth>

The letter of the present invention preferably has a warmth of 15% or more and 50% or less. When the warming property is 15% or more, warmness can be obtained as an undergarment, and when it is 50% or less, it is not too hot.

Example

The acrylic fiber of the present invention will be described using the following examples.

(Method for Measuring Unevenness of Fiber Surface)

The depth of the concavities and convexities of the acrylic fiber of the present invention is represented by the following center line average roughness (Ra), maximum height (Ry), 30 point average roughness (Rz) and local calculation interval (S). These are measured by using a laser microscope.

Figs. 1 to 4 are diagrams schematically showing the cross-sectional shape of a short fiber surface in a cross section perpendicular to the fiber longitudinal direction of the short fibers constituting the acrylic fiber of the present invention. Fig.

(Centerline average roughness <Ra> of the surface of the short fiber)

As shown in Fig. 1, the centerline average roughness (Ra) of the surface of the short fibers is such that only the reference length L is extracted from the roughness curve in the direction of the center line m thereof and the absolute value of the deviation , And a value obtained by averaging the values is expressed in nanometers (nm).

(Maximum height of surface of short fiber < Ry >)

As shown in Fig. 2, the maximum height Ry of the surface of the short fiber refers only to the reference length L in the direction of the center line m from the roughness curve, and the interval Rp between the highest line and the center line m And the sum Rv + Rv of the interval Rv between the lowest bone bottom line and the center line m, and this value is expressed in nanometers (nm).

(30 point average roughness <Rz> of the surface of the short fiber)

As shown in Fig. 3, the 30-point average roughness (Rz) of the surface of the staple fibers refers to the roughness (Rz) of the surface of the staple fibers, in which only the reference length is extracted in the direction of the average line thereof from the roughness curve, The sum of the average value of the absolute values of the calculated elevation Yp from the highest elevation to the 15th elevation and the average value of the absolute values of the elevation of the bottom elevation Yv from the lowest elevation to the 15th elevation is obtained, nm).

(Distance between vertices <S> of convex portions of the surface of short fibers)

As shown in Fig. 4, the distance (S) between the apexes of the protrusions on the surface of the short fiber is such that only the reference length L is extracted from the roughness curve in the direction of the center line m thereof and the length of the corresponding average line is obtained , And the average value of these multiple local estimates in nanometers (nm).

(Strong, strong, nodular)

And measured according to JIS L1015.

(The number of recesses having a depth of 0.1 占 퐉 or more in fiber cross-section)

The hot air of the dryer is sprayed on the acrylic fiber of 200 or more and 300 or less of the present invention, and the shrinkage of the fiber is spread out into the tube. Here, the polyethylene tube was used which was shrunk only in the circumferential direction.

Next, the polyethylene tube filled with the acrylic fibers of the present invention was cut in a direction substantially perpendicular to the axial direction of the unused razor blade to a length of about 2 mm.

One side of the cut surface was fixed to a table with a double-sided tape, and a test piece was observed with a low temperature ion sputtering apparatus (JFC1100, manufactured by Nihon Electronics Co., Ltd.) under the conditions of 1200 V, 5 mA for 8 minutes, Gold was deposited on the cut face of the acrylic fiber of the present invention as a face to prepare a sample.

A cross-section of the fiber of the sample was photographed at a magnification of 5,000 times using a scanning electron microscope (Philips, product number XL-20), and one concave portion on the fiber surface was determined from the photographed image, The depth of the concave portion in the cross section of the fiber and the number of the concave portion having a depth of 0.1 占 퐉 or more were counted as the longest length of the line perpendicular to the concave portion from the tangent line connecting the convex portion. Three fiber cross-sections were measured, and the average value thereof was determined as the number of recesses having a depth of 0.1 占 퐉 or more at the fiber cross-section.

(Gloss evaluation)

The glossiness was evaluated as follows.

100% of each of the acrylic fibers of Examples 1 and 2 and Comparative Example 1 was used as a spun yarn under the same conditions, and a fabric was produced under the same conditions.

?: Good glossiness,

X: poor glossiness.

(Example 1)

An acrylonitrile copolymer having a reduced viscosity of 1.8 and consisting of 95% of acrylonitrile, 4.4% of vinyl acetate, and 0.6% of sodium methallylsulfonate was dissolved in dimethylacetamide to obtain a copolymer having a copolymer concentration of 24% A spinning stock solution having a viscosity of 200 poise was obtained.

This spinning liquid was discharged from a plurality of discharging holes having a pore size of 0.045 mm into a coagulating liquid having a concentration of dimethyl acetamide of 56% and a temperature of 41 캜 to form a fiber, and while the solvent was washed in hot water at 98 캜, . Subsequently, the emulsion was adhered, dried with a plurality of heat rollers whose surface temperature was set to 150 占 폚, further heated with a 180 占 폚 heat roller to adjust the fiber temperature to 160 占 폚, stretched in air twice, Then, I shook the container.

In addition, heat relaxation treatment was carried out so that the heat shrinkage rate in the fibers was 7% or more and 9% or less to obtain fibers having a single fiber fineness of 1.0 dtex. Table 1 shows the conditions, and Table 2 shows the results.

The product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) of the fiber was 15.9, which was a value at which the peeling resistance was good. In addition, the number of concave portions having a depth of 0.1 占 퐉 or more was two, which was superior in glossiness to the comparative example.

(Example 2)

The wet heat stretching magnification and the dry heat stretching magnification were changed. Table 1 shows the conditions, and Table 2 shows the results.

As a result, the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) was 16.6, which was a value at which the peelability was good. In addition, the number of concave portions having a depth of 0.1 탆 or more was four, which was superior in glossiness to the comparative example.

(Examples 3 to 11)

Acrylic fibers were produced in the same manner as in Example 1 except that the production conditions of the acrylic fibers were changed as shown in Table 1. Table 1 shows the physical properties of the acrylic fiber.

(Comparative Example 1)

Acrylic fibers were produced in the same manner as in Example 1 except that dry heat stretching was not performed and the magnification of the hot water drawing was increased to make the total drawing magnification the same. Table 1 shows the conditions, and Table 2 shows the results.

As a result, the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) was 25.7, which was excellent in peeling but was not a good value as compared with the acrylic fiber of the present invention. In addition, the number of concave portions having a depth of 0.1 占 퐉 or more was 15, and gloss was poor.

(Comparative Example 2)

Acrylic fibers were produced in the same manner as in Example 3 except that dry heat stretching was not performed and the magnification of the hot water drawing was increased to make the total drawing magnification the same. Table 1 shows the conditions, and Table 2 shows the results.

As a result, the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) was 20, which was excellent in peelability but was not a good value as compared with the acrylic fiber of the present invention. In addition, the gloss was poor.

(Comparative Example 3)

Acrylic fibers were prepared under the conditions for producing the acrylic fiber for the carbon fiber precursor described in JP-A-2013-209771. Table 1 shows the conditions, and Table 2 shows the results.

The acrylic fiber for the carbon fiber precursor had a low product K of the nodal strength and strength, and was inferior in spinning property during spinning, and thus could not spin.

(Comparative Example 4)

An acrylic fiber having a monofilament fineness of 22 dtex and a flatness ratio of 22 was produced according to the conditions for producing the glossy fiber described in Japanese Patent Laid-Open No. 11-222716. Table 1 shows the conditions, and Table 2 shows the results.

The product K is a range that exhibits anti-peeling property, but is unsuitable for medical use because of a thick fineness and poor texture.

(Example 12)

A cotton yarn having a yarn number of 50 in the number of yarns and a twist number of 873 t / m was produced by mixing 70% by mass of the acrylic fiber of Example 1 and 30% by mass of Micro Modal (manufactured by Renting Co., 1.0 dtex). The physical properties thereof are shown in Table 2.

(Example 13)

A yarn with a yarn number of 60 and a twist number of 1139 t / m was produced with 100% by mass of the acrylic fiber of Example 1 as yarn number. The physical properties thereof are shown in Table 2.

(Examples 14 and 15)

Spinning yarn was obtained in the same manner as in Example 13 except that the folding number was changed as shown in Table 2. The physical properties thereof are shown in Table 2.

(Example 16)

A yarn having a yarn count of 40 yarns per square turn and a number of twists of 820 t / m was prepared with the acrylic fiber of Example 11 as 100 mass%. The physical properties thereof are shown in Table 2.

(Comparative Example 5)

A cotton yarn having a yarn number of 50 in the number of yarns and a number of twists of 900 t / m was produced by mixing 70% by mass of the acrylic fiber of Comparative Example 1 and 30% by mass of Micro Modal (manufactured by Renting Co., 1.0 dtex). The physical properties thereof are shown in Table 2.

It was found that the yarn unevenness was large as compared with the twelfth embodiment.

Further, when the spinning yarn of Example 12 and the spinning yarn of Comparative Example 5 were visually observed in a state of being wound around a cone, it was confirmed that the spinning yarn of Example 12 was glossy.

(Comparative Example 6)

A yarn with a yarn number of 60 and a twist number of 1139 t / m was produced in an amount of 100% by mass of the acrylic fiber of Comparative Example 1 and yarn number of yarn counts. The physical properties thereof are shown in Table 2.

And the yarn unevenness was large as compared with Example 13. [

(Comparative Examples 7 and 8)

Spinning yarn was obtained in the same manner as in Comparative Example 6 except that the folding number was changed as shown in Table 2. The physical properties thereof are shown in Table 2.

(Comparative Example 9)

A yarn with a yarn count of 40 in the number of yarn counts and a twist count of 820 t / m was prepared by using the acrylic fiber of Comparative Example 2 as 100 mass%. The physical properties thereof are shown in Table 2.

When the spinning yarns of Comparative Examples 6 to 9 corresponding to the spinning yarns of Examples 13 to 16 were wound around the cones visually, it was confirmed that the spinning yarns of the respective Examples were glossy.

(Example 17)

Using the spinning yarn of Example 15, a transverse letter of a sheath structure was formed at 14G. The basis weight was 210 g / m ² , the peeling performance was 4.5 and the warmth was 45.1%.

(Comparative Example 10)

Using the spinning yarn of Comparative Example 8, a transverse letter of a sheath structure was formed at 14G. The basis weight was 210 g / m ² , and the peeling performance was 4.5 and 44.9%.

However, the gloss was inferior to Example 17.

Claims (14)

Wherein the center line average roughness (Ra) of the surface of the single fibers is 3 nm or more and 12 nm or less, and the monofilament fineness is 0.5 dtex or more and 3.5 dtex or less. Wherein the center line average roughness (Ra) of the surface of the short fibers is 3 nm or more and 12 nm or less and the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) is 10 or more and 30 or less. The method according to claim 1,
Wherein the product K of the value of the nodule strength (cN / dtex) and the value of the nodule elongation (%) is 10 or more and 30 or less. 3. The method of claim 2,
Acrylic fiber having a monofilament fineness of 0.5 dtex or more and 3.5 dtex or less. 5. The method according to any one of claims 1 to 4,
Wherein the maximum height difference Ry of the surface of the short fibers is 40 nm or more and 150 nm or less, the 30-point average roughness (Rz) is 20 nm or more and 80 nm or less, and the distance S between the apexes of the convex portions on the surface of the short fibers is 800 nm or more and 1100 nm or less. 6. The method according to any one of claims 1 to 5,
Wherein a concave portion having a depth of 0.1 占 퐉 or more on the surface of the short fibers at a cross section in a direction perpendicular to the fiber axis is 10 or less. 7. The method according to any one of claims 1 to 6,
Acrylic polymer comprising acrylonitrile units of 92 mass% or more and 96.8 mass% or less, vinyl monomer units of 2 mass% or more and 6 mass% or less, and sulfonic acid group-containing vinyl monomer units of 0.2 mass% or more and 2.0 mass% or less, An acrylic fiber having a fiber tensile strength of not less than 1.8 cN / dtex and not more than 3.0 cN / dtex, a short fiber nodule strength of not less than 1.0 cN / dtex and not more than 1.8 cN / dtex, and a short fiber nodule elongation of not less than 8% nor more than 20%. An acrylonitrile copolymer comprising 92% by mass or more and 96.8% by mass or more of acrylonitrile units and 0.2% by mass or more and 2.0% by mass or less of vinyl monomer units containing a sulfonic acid group is dissolved in an organic solvent, The spinning stock solution is discharged into a coagulating bath having a temperature of 35 ° C to 50 ° C at a jet stretch of 0.4 or more and 2.2 or less from the discharge hole of the spinning nozzle to form the coagulated fiber, , Stretching the fiber at a draw ratio of 1.2 times to 3 times at dry heat at a fiber temperature of 150 占 폚 or more and 170 占 폚 or less, Wherein the product S of the draw ratio in the dry heat and the draw ratio in the dry heat is 4 times or more and 6 times or less. 9. The method of claim 8,
Wherein the acrylonitrile-based copolymer further comprises 2% by mass or more and 6% by mass or less of vinyl monomer units, the solvent concentration of the coagulating bath is 40% by mass or more and 60% by mass or less, Of the acrylic fiber. 10. The method according to claim 8 or 9,
Wherein the thermal relaxation treatment temperature is not less than 120 ° C and not more than 135 ° C and the fiber relaxation rate is not less than 5% and not more than 20%. A yarn comprising 40% by mass or more of the acrylic fiber according to any one of claims 1 to 7, wherein the yarn count is less than 40 times and not more than 70 times as the yarn count. 12. The method of claim 11,
Wherein the cellulose fiber comprises 10% by mass or more and 40% by mass or less of cellulose fibers. A letter containing at least 40 mass% of the yarn described in claim 11 or 12, having a basis weight of at least 150 g / m ² and at most 230 g / m ² , and a peeling performance of at least grade 4. 14. The method of claim 13,
Letters with an insulation rate of 15% or more and 50% or less.

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