JP2003301322A - Acrylic modified cross section high-fineness fiber and method producing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide acrylic modified cross section high-fineness fiber that is produced by a wet spinning process and has good firmness and resilience, slimy feeling and shows excellent processability, good physical properties and soft fabric hand. <P>SOLUTION: The acrylic modified cross section high-fineness fiber that has the flatness of the cross section of a single filament of 1.5-5.0, a single filament fineness of ≤2.0 dtex, a single filament strength of ≥3.0 cN/dtex is produced through the wet process by dissolving a polymer including ≥80 wt.% of acrylonitrile in an organic solvent so that the polymer concentration reaches 12-30 wt.%, using the solution as a spinning dope to extrude out the dope through the nozzles having a hole area of 2.0×10<SP>-3</SP>-15×10<SP>-3</SP>mm<SP>2</SP>/each hole and winding up the filaments at a spinning draft ratio of 0.1-0.5 and drawing the coagulated filaments at a draw ratio of 7-15. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic modified fine cross-section fine fiber suitable for clothing and construction and bedding, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, acrylic fibers have been used in curtains, carpets, high piles, moquettes, blankets, etc. for construction and bedding, and knits, jerseys, etc. due to their excellent bulkiness, texture and dyeability. Widely used. The cross-sectional shape of the fiber is greatly related to the appearance of the final product, particularly the texture, and the characteristics of the product are determined, and the cross-section of the acrylic fiber has a perfect circle shape, a beans shape, a flat shape, etc.
Among them, the ellipse, especially the dumbbell-shaped (dockbone-shaped) cross section, is characterized by softness, elasticity, sliminess, etc. and gives a very good texture to clothing, construction and bedding applications and final products.

On the other hand, the recent market has tended to be softened, and there is a demand for softer and better textured products.
Therefore, there is a high demand for fine fiber having a fineness of 2.0 dtex or less which gives a soft feeling, and fine fiber is also required for acrylic fiber. However, in the case of fine fiber, the productivity in the spinning process becomes low, and problems such as yarn breakage and fluff tend to occur in processability, and there is a great demand for highly productive and high-strength acrylic fine fiber. It is expensive.

In the case of an acrylic fiber having a modified cross section such as a flat or dumbbell-shaped cross section, when a wet spinning method is used, a modified nozzle having a desired shape is used, for example, as in the embodiment of JP-A-11-217723. However, it is more difficult to process this type of irregular-shaped nozzle than the ordinary round-shaped nozzle, and the cost is high. Therefore, the monofilament fineness that can be produced is limited. In other words, it was very difficult to obtain fine fiber with a modified cross-section acrylic fiber by the wet spinning method.

Further, it is necessary to adopt spinning conditions for maintaining the shape of the modified nozzle on the fiber, and in that case, it tends to be difficult to obtain a high-strength fiber. On the other hand, Japanese Patent Application Laid-Open No. 8-337917 proposes a method for producing a modified cross-section fiber by using a core-sheath composite type spinning nozzle and using components having different solidification values in a core portion and a sheath portion. However, it is necessary to use a special nozzle and a nozzle holder, which increases the manufacturing cost and also makes it difficult to easily obtain fine fiber. In addition, JP-A-6-22
As proposed in Japanese Patent No. 0720, an acrylic fiber having a modified cross section and fineness can be obtained by the dry spinning method, but in this case also, there is a problem that the productivity is very low and the manufacturing cost is high. It was

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a wet-spinning acrylic modified cross-section having good elasticity, slimy feel, good workability and good physical properties, and soft and excellent texture. To provide fine fiber.

[0007]

The present invention is obtained by a wet spinning method from an acrylonitrile-based polymer containing 80% by weight or more of acrylonitrile, and the cross-sectional shape of the single fiber is in the range of oblateness of 1.5 to 5.0. It is irregularly shaped, the single fiber fineness is 2.0 dtex or less, and the single fiber strength is 3.0 cN /
Acrylic-based polymer having a fine cross-section fineness of acrylic having a dtex of at least dtex, and an acrylonitrile-based polymer containing 80% by weight or more of acrylonitrile at a polymer concentration of 12
Using a spinning dope that is dissolved in an organic solvent so as to be ˜30% by weight, the pore area per hole is 2.0 × 10 ⁻³ to 15 × in a coagulation bath having an organic solvent concentration of 15 to 45% by weight. 1
0 ^-3 mm ejected from ^{2. The} term nozzle, the spun yarn take-up speed ratio of the relative spinning solution discharge speed from the nozzle 0.1
In the method for producing an acrylic modified fine cross-section fineness fiber, the yarn is spun in a range of from 0.5 to 0.5 and the yarn exiting the coagulation bath is stretched 7 to 15 times.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylonitrile (hereinafter abbreviated as AN) polymer in the present invention is a polymer containing AN in an amount of 80% by weight or more, preferably 90% by weight or more,
Although it may be a homopolymer of AN, it may be an AN copolymer in which a vinyl monomer copolymerizable with AN is copolymerized within a range not exceeding 20% by weight. When the amount of AN in the AN polymer is less than 80% by weight, the fiber has poor physical properties and heat resistance.

Examples of vinyl monomers copolymerizable with AN include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid and salts thereof, and methacrylic acid esters such as methyl acrylate and butyl acrylate. , Vinyl vinyl ketones, vinyl acetate and other vinyl esters, acrylamide and alkyl-substituted products thereof, unsaturated sulfonic acids such as vinyl sulfonic acid and methallyl sulfonic acid and salts thereof, styrene such as styrene and α-methyl styrene, and their Examples thereof include alkyl or halogen substituted compounds, allyl alcohol and its esters or ethers, vinyl halides such as vinyl chloride and vinylidene chloride, and vinylidene halides.

The acrylic modified fine cross-section fineness fiber of the present invention is a fiber obtained by a wet spinning method and has a modified shape in which the cross-sectional shape of the single fiber is in the range of an oblateness of 1.5 to 5.0. There is. It is preferable that the modified cross-section has an oval shape or dumbbell shape in order to exert a slimy feeling in addition to a soft feeling. The flatness is the long side a in the fiber cross section.
And the ratio a / b of the short side b. If the oblateness is less than 1.5,
When the flattening ratio exceeds 5.0, the deforming effect does not appear, and the flatness exceeds 5.0, the processability such as spinning is deteriorated, and the fiber itself becomes stiff.

Further, the acrylic modified fine cross-section fine fiber of the present invention has requirements that the single fiber fineness is 2.0 dtex or less and the single fiber strength is 3.0 cN / dtex or more. If the single fiber fineness exceeds 2.0 dtex, the soft texture will not be exhibited. The single fiber strength is 3.0
If it is less than cN / dtex, fuzz and yarn breakage easily occur, resulting in poor processability.

The acrylic modified fine cross-section fineness fiber of the present invention is produced by the following method. That is, the acrylic modified fine cross-section fineness fiber of the present invention uses a spinning stock solution in which an AN polymer containing 80% by weight or more of AN is dissolved in an organic solvent so as to have a polymer concentration of 12 to 30% by weight, and an organic solvent concentration of 15 to In a coagulation bath of 45% by weight, a nozzle having a hole area of 2.0 × 10 ⁻³ to 15 × 10 ⁻³ mm ² per hole was discharged, and the spinning yarn was discharged from the nozzle at a spinning stock solution discharge speed. The take-up speed ratio, that is, the spinning draft is 0.1 to
The number of yarns spun in the range of 0.5 and leaving the coagulation bath is 7
It can be produced by stretching at a stretch of 15 times.

In the production method of the present invention, the polymer concentration in the spinning dope, the organic solvent concentration in the coagulation bath, and the spinning draft are important factors for obtaining a modified cross-section fiber having an oblateness of 1.5 to 5.0. If the polymer concentration in the spinning dope is less than 12% by weight, the desired modified cross-sectional shape cannot be obtained. If the polymer concentration in the spinning dope exceeds 30% by weight, the stability of the spinning dope is poor and the spinnability is adversely affected. give.

The concentration of the organic solvent in the coagulation bath is 15 to 45% by weight, preferably 20 to 35% by weight. If the physical properties of the yarn are not obtained and the concentration of the organic solvent exceeds 45% by weight, the desired modified cross-sectional shape cannot be obtained.
On the other hand, if the spinning draft is less than 0.1, the yarn will be loosened in the coagulation bath to generate adhesive fibers and fineness unevenness, and if the spinning draft exceeds 0.5, the target irregular cross-sectional shape cannot be obtained.

In the production method of the present invention, the organic solvent used for the spinning stock solution and the coagulation bath may be any organic solvent capable of dissolving an AN polymer such as dimethylacetamide, dimethylformamide, and acetone. The spinning solution, the organic solvent used in the coagulation bath may be different from each other, but the organic solvent cost,
In order to simplify the recovery process, it is preferable to use the same solvent for the spinning dope and the coagulation bath.

The nozzle for discharging the spinning dope into the coagulation bath has a hole area of 2.0 × 10 ⁻³ to 15 × 10 ⁻³ mm ² , preferably 1 hole, for obtaining the desired fineness fiber. A nozzle having a size of 2.5 × 10 ⁻³ to 10 × 10 ⁻³ mm ² is used. If the hole area is less than 2.0 × 10 ⁻³ mm ^2, it is difficult to manufacture the nozzle and the spinning stability is deteriorated due to the nozzle clogging, and the hole area is 15 × 10 ⁻³ mm.
^When it exceeds ² , it becomes difficult to obtain the desired fineness of 2.0 dtex or less.

Further, in the production method of the present invention, the stretching is an important step particularly for giving strength to the fiber,
In order to obtain fibers having a single fiber strength of 3.0 cN / dtex or more, it is necessary to draw the yarn that has exited the coagulation bath in the wet spinning step 7 to 15 times. If the magnification is less than 7 times, the intended single fiber strength cannot be obtained, and if the magnification exceeds 15 times,
Stretch breakage is likely to occur in the spinning process, resulting in poor spinnability.

The stretching in the manufacturing method of the present invention is
In order to stabilize the spinnability, it is preferable to draw the yarns from the coagulation bath in multiple stages. Preferred multi-stage drawing is to prepare the yarns from the coagulation bath in an organic solvent concentration of 20% by weight or less. 50 to 100 after being drawn 1.0 to 3.0 times, more preferably 1.0 to 2.0 times in a drawing tank at ˜70 ° C.
3.0 to 12.0 times, more preferably 4.
After stretching 0 to 9.0 times, applying an oil agent and drying and densifying, it is further dried at 100 to 200 ° C. or 1.0 to 3.
It is stretched at 0 times, more preferably 1.0 to 2.5 times, and at a total stretching ratio of 7 to 15 times.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples.

Examples 1 to 4 and Comparative Examples 1 to 6 The vinyl acetate copolymerized AN polymers having the AN contents shown in Table 1 were used.
It was dissolved in dimethylacetamide (hereinafter referred to as DMAc) to prepare a spinning dope having a polymer concentration of 20% by weight. A DMAc aqueous solution having a DMAc concentration shown in Table 1 was prepared from this spinning dope by using a nozzle having a pore size of 30 to 50 μm, a circular pore shape, a pore area per hole of 6.5 × 10 ⁻³ mm ² and a number of pores of 30,000. Was discharged into a coagulation bath having a bath temperature of 35 ° C. and spun in the spinning draft shown in Table 1, and the coagulated yarn was drawn to the full draw ratio shown in Table 1. In Examples 1, 2, 4, and Comparative Examples 4 to 6, DM was used.
1.0 times in a drawing tank at 35 ° C with an Ac concentration of 50% by weight or less,
Total draw ratio of 9 times under wet heat of 80 ° C, 6.0 times, and after applying oil agent and dry densification treatment, under dry heat of 180 ° C, 1.5 times.
In Example 3 and Comparative Examples 1 to 3, the film was drawn twice, 1.2 times in the same drawing tank, 6.0 times in the same moist heat, further, after applying an oil agent and drying and densifying treatment, 1 in the same dry heat. The film was stretched to a total draw ratio of 12 times of 0.67 times.

The obtained tow was subjected to a relaxation treatment in a steam pressure of 250 Kpa and then mechanically crimped to obtain a fiber having a single fiber fineness of 1.0 to 1.5 dtex. Table 2 shows the spinnability, the cross-sectional shape, the fineness of the single fiber, and the strength of the obtained fiber.

[0022]

[Table 1]

[0023]

[Table 2]

(Comparative Examples 7 to 9) An AN polymer of vinyl acetate copolymerization having an AN content of 93% by weight was dissolved in DMAc to prepare a spinning dope prepared to have a polymer concentration of 10% by weight. A single fiber fineness of 0.8d was obtained in the same manner as in Example 1 except that the coagulation bath having a concentration and the spinning draft were used.
A fiber having a tex of 2.2 cN / dtex was obtained. The stretching with a total stretching ratio of 12 times in Comparative Examples 7 and 8 was performed under the same stretching conditions as in Example 3, and the stretching with a total stretching ratio of 9 times in Comparative Example 9 was performed under the same stretching conditions as in Example 1. It was The fiber cross-sectional shape of the obtained fiber is as shown in Table 3.

[0025]

[Table 3]

(Comparative Example 10) A vinyl acetate copolymer AN polymer having an AN content of 93% by weight was dissolved in DMAc to prepare a spinning dope prepared to have a polymer concentration of 15% by weight. After spinning, the coagulated yarn was drawn 1.2 times in a draw tank, 5.0 times under wet heat, and 1.0 times under dry heat to a total draw ratio of 6 times. The obtained fiber had a single fiber fineness of 1.0 dtex and a cross-sectional shape of dumbbell type having an oblateness of 2.8, but the single fiber strength was 2.5 cN / dtex. The fiber obtained in Example 3 had a single fiber strength of 3.6 cN / dtex.

[0027]

EFFECTS OF THE INVENTION The acrylic modified fine cross-section fineness fiber of the present invention is obtained by a wet spinning method and has a good elasticity.
It has a slimy feel, excellent workability, good physical properties, is extremely soft and has an excellent texture. It is used for construction and bedding such as curtains, carpets, high piles, moquettes and blankets, and knitwear and jersey clothing. It is suitable in the field. In addition, the spinning solution concentration, coagulation bath concentration, nozzle hole area,
According to the production method of the present invention in which the spinning draft and the draw ratio are combined, it is possible to produce such an acrylic modified fine cross-section fineness fiber with high productivity and low cost by the wet spinning method.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiko Hosako             20-1 Miyuki-cho, Otake-shi, Hiroshima Mitsubishi Rayo             Otake Office F term (reference) 4L035 BB03 BB06 BB11 BB15 BB17                       BB22 BB59 BB69 BB73 BB85                       BB89 BB90 BB91 CC05 CC07                       DD02 EE08 MB16

Claims (4)

[Claims] 1. A monofilament obtained by a wet spinning method from an acrylonitrile-based polymer containing 80% by weight or more of acrylonitrile, has a cross-sectional shape of a monofilament having an oblateness of 1.5 to 5.0, and has a monofilament fineness. An acrylic-based fine cross-section fineness fiber having a single fiber strength of 3.0 cN / dtex or more and 2.0 dtex or less. 2. The acrylic fine cross-section fineness fiber according to claim 1, wherein the single fiber has an elliptical or dumbbell-shaped cross-section. 3. An acrylonitrile-based polymer containing 80% by weight or more of acrylonitrile has a polymer concentration of 12 to 30.
Using a spinning dope that is dissolved in an organic solvent so that the weight ratio becomes 1%, 1% is added to a coagulation bath having an organic solvent concentration of 15 to 45% by weight.
The hole area per hole is 2.0 × 10 ⁻³ to 15 × 10 ^−3.
It discharged from mm ² at a nozzle, from 0.1 to 0 a spun yarn take-up speed ratio of the relative spinning solution discharge speed from the nozzle.
The range of 5 is 7 and the number of yarns spun from the coagulation bath is 7-1.
A method for producing an acrylic-based fine cross-section fineness fiber, which comprises stretching the fiber 5 times. 4. The yarn from the coagulation bath has an organic solvent concentration of 7
After drawing 1.0 to 3.0 times in a drawing tank of 0% by weight or less, drawing to 3.0 to 12.0 times under moist heat to apply an oil agent,
After dry densification, it is further heated under dry heat or pressurized steam to 1.0 to 3.
The method for producing an acrylic modified fine cross-section fineness fiber according to claim 3, wherein the fiber is drawn 0 times and drawn at a total draw ratio of 7 to 15 times.