JP3168057B2 - Manufacturing method of anti-pilling acrylic fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an acrylic fiber having excellent anti-pilling properties, and more particularly, to an anti-pilling adhesive having excellent gloss obtained by dry spinning.
The present invention relates to a method for producing krill-based fibers .

[0002]

2. Description of the Related Art Dry spun acrylic fibers have a smooth surface and good transparency due to their dense structure, and have favorable properties as clothing fibers. On the other hand, anti-pilling properties (hereinafter referred to as anti-pill properties) Abbreviations), which is a serious factor limiting product applications.

[0003] As a method for improving the pill resistance of acrylic fiber, a low draw ratio is employed in the fiber production process disclosed in JP-A-57-121610 and the like. Attempts have been made to reduce the strength of the indicated fibers by imparting localized defects to the fibers. Although practically desirable anti-pill properties have been obtained by these methods, there are not many examples, but on the other hand, the post-processability is deteriorated due to the decrease in fiber strength, that is, the spinning passability is poor. In the case of measuring, for example, frying occurs, yarn spots are increased, and spun yarn strength is reduced, resulting in major defects such as deterioration of product quality and impairment of high workability.

On the other hand, as a method for obtaining a fiber having a sufficient tensile strength without lowering the strength of a single fiber and having an excellent pill resistance and good post-processability, Japanese Patent Application Laid-Open No. Sho 51-1021 discloses a method.
There is a technology disclosed in Japanese Patent Publication No. This technique uses a composition of an acrylonitrile-based polymer for forming a fiber of 94% by weight or more of acrylonitrile, 0.5 to 3.5% by weight of a strong acid group-containing monomer, and 2.5 to 5.5% by weight of another monomer. This acrylonitrile-based polymer is wet-spun and then
~ 7 times hot stretching, after drying 1.1 ~ 90 ~ 180 ℃
The content is that the film is stretched 2.4 times and set at a fixed length at a temperature higher than the stretching temperature.

[0005] However, this technique is a very effective method when the wet spinning method is employed, but the fiber obtained by employing the dry spinning method as the spinning method is likely to generate a large amount of fly during yarn processing. There are many points to be improved, such as difficulty in dyeing due to the high boiling water shrinkage of the fiber and lowering of the pill resistance after boiling water shrinkage compared to the original yarn.

[0006]

[0008] The present invention is in a dry acrylic fiber are favored widely consumer as luxury clothing fibers, good gloss and sufficient tensile have strong, post-processing of the good anti Made of pilling acrylic fiber
It provides a manufacturing method .

[0007]

According to the present invention , there is provided a tensile strength of 1.2 to 3 g obtained by dry spinning an acrylonitrile-based polymer containing at least 92% by weight of acrylonitrile.
/ D, the product of knot strength (g / d) and knot elongation (%) is 40
Hereinafter, there is provided a method for producing an anti-pilling acrylonitrile-based fiber , characterized in that a boiling water shrinkage ratio satisfies a condition of 3% or less and a fiber cross-sectional shape irregularity of 2 or less.

More specifically , an acrylonitrile-based polymer containing 92% by weight or more of acrylonitrile is
A high-concentration stock solution containing 43% by weight is dry-spun from a nozzle having one or a combination of two or more of triangular, square, cross, Y-shaped, and star-shaped nozzle holes.
The film is primarily stretched in a range of up to 4 times, and then subjected to a drying and relaxation heat treatment to give a shrinkage of 10 to 40%.
After secondary stretched 1.2 to 2.5 times to 200 DEG ° C., preparation der the above pilling resistance acrylonitrile fibers, which comprises fixed-length heat treatment at a stretched temperature or higher
You .

The cross-section of the acrylic fiber of the present invention has a small cross-sectional shape such as an elliptical shape or a Z-shape, unlike the dumbbell shape of a normal dry acrylic fiber. As used herein, the term "irregularity" refers to the ratio of the diameter of the longest axis to the shortest axis of the diameter of the fiber cross section.

The irregularity of the fibers according to the invention is usually 2.5
For ５5, it is necessary to be 2 or less. In addition, the acrylic fiber of the present invention has sufficient tensile strength and elongation, and does not generate fly even in a post-process such as spinning.
Excellent in post-processability. The fiber of the present invention has a knot strength (hereinafter, abbreviated as DKS) and a knot elongation (hereinafter, DK).
Abbreviated as E. ) Shows an extremely low value (DKS × DKE). The DKS × DKE value of a normal dry acrylic fiber is a value of 40 to 80, but the DKS × DKE × of the fiber according to the present invention.
The DKE value needs to be 40 or less.

Further, the present invention uses the acrylonitrile-based polymer described above, has a specific fiber cross-sectional shape, and satisfies a specific DKS × DKE value and a boiling water shrinkage ratio. It is characterized in that a dry acrylic fiber having both pill properties can be obtained.

Hereinafter, the present invention will be described in more detail. The acrylonitrile polymer which is the object of the present invention is 92% by weight.
It is necessary to contain the above acrylonitrile component. When the content of the acrylonitrile component is less than 92% by weight, the obtained fiber cannot obtain the DKS × DKE value or the boiling water shrinkage ratio of the present invention even when the fiber irregularity is 2 or less, and the anti-pill property is poor. .

In the present invention, the polymer may contain up to 8% by weight of a monoethylenic vinyl polymer component, which can be arbitrarily selected according to the purpose. Specific examples of the monoethylenic vinyl monomer copolymerizable with acrylonitrile include (meth) acrylates such as methyl acrylate and methyl methacrylate, vinyl acetate, styrene, and acrylamide. Methyl acrylate is desirable in terms of properties. In order to further improve the dyeability, (meth) acrylic acid, (meth) allylsulfonic acid or vinylbenzenesulfonic acid and their salts, dimethylaminoethyl (meth) acrylate, vinylpyridines are copolymerized. Is also good.

This polymer is prepared by a conventional suspension polymerization, solution polymerization,
It can be produced by any method such as emulsion polymerization. The degree of polymerization of the polymer is represented by its specific viscosity of 0.10 to 0.2.
A range of 0 is preferred. The stock solution for polymer spinning is prepared by dissolving the polymer in a solvent of a usual acrylonitrile-based polymer, for example, dimethylformamide, dimethylacetamide, dimethylsulfoxide or the like so that the polymer concentration becomes 32 to 43% by weight.

The spinning is performed by discharging into a high-temperature air or an inert gas through a non-circular hole-shaped nozzle such as a triangle, a square, a cross, a Y-shape, and a star, and the solvent is evaporated to obtain an undrawn yarn. When the polymer concentration is less than 32%, the cross-sectional shape of the fiber obtained using any non-circular hole-shaped nozzle exhibits a dumbbell-shaped cross-section with a degree of irregularity of 2.5 or more. Even when the polymer concentration is 32 to 43% by weight, a dumbbell-shaped cross section having a degree of irregularity of 2.5 or more is similarly exhibited when a nozzle having a circular hole shape is used. When the above-mentioned dumbbell-shaped cross section is exhibited, the obtained fiber has poor anti-pill property. The shape of the nozzle hole is particularly preferably a cross.

The dry-spun undrawn yarn is first drawn in a range of 1.2 to 4 times at 70 ° C. to hot water. Stretching temperature is 7
If the temperature is lower than 0 ° C., sufficient stretchability and washability cannot be obtained.
When the draw ratio is less than 1.2 times, even if the secondary draw ratio is increased, sufficient strength is not imparted to the finally obtained fiber, while when it exceeds 4 times, the finally obtained fiber It is necessary to increase the secondary stretching ratio in order to make the DKS × DKE value of 40 or less, and as a result, the tensile strength is 3 g / d.
And the anti-pill property becomes poor. The undrawn yarn is washed in hot water simultaneously with or before and after the drawing process.
The temperature of the hot water is preferably from 80 to 100C. The amount of residual solvent after washing is usually less than 2%. The fiber bundle that has been subjected to the stretching cleaning treatment is then subjected to a drying and relaxation treatment.

Drying is usually performed at a surface temperature of about 115 to 150 ° C.
A typical method is to pass the sheet under tension on a hot roll. In this case, densification of the fiber is also achieved at the same time.
On the other hand, it is also possible to perform a relaxation heat treatment simultaneously with the drying. The yarn after hot water drawing is kept in a wet state under no tension while maintaining a relative humidity of about 10 to 40% and a temperature of 110 to 160 ° C. in heated air. Is also a preferred method. Also,
As another relaxation heat treatment method, a method of heat-treating the once-dried yarn in pressurized steam at a temperature of about 100 to 140 ° C. is also simple and effective. The heat treatment as described above gives the fibers a shrinkage of 10-40%.

The relaxation and shrinkage treatment imparts basic properties such as dyeability and form stability required for clothing fibers.
When the shrinkage is less than 10%, sufficient dyeability is not obtained, and when the shrinkage is more than 40%, the DKS × DKE value eventually leads to a decrease in anti-pill property throughout the subsequent processes of the present invention.

The fiber bundle that has been subjected to the drying and relaxation treatment is secondarily drawn 1.2 to 2.5 times at a temperature of 160 to 200 ° C. As a result, the fiber strength is further improved, and good post-process passability such as spinning is secured, and at the same time, DKS × DK
The E value decreases and the anti-pill property improves. The secondary stretching is performed between heated hot rolls, on a hot plate or in heated steam. When the stretching temperature is lower than 160 ° C., the secondary stretchability is low and causes fluffing. When the stretching temperature is higher than 200 ° C., the stretchability is reduced again, the coloring tendency of the fibers is increased, and fusion between the single fibers is caused. Decrease value. The secondary stretching ratio is 1.2
The intended effect can be obtained by adopting the above,
If the magnification exceeds 2.5, thread breakage occurs frequently and stable operation cannot be achieved.

The secondary drawn yarn is immediately subjected to a constant length treatment at a temperature not lower than its drawing temperature for several seconds to several minutes. When this constant-length heat treatment is not performed or when the treatment is performed at a temperature lower than the secondary drawing temperature, the boiling water shrinkage of the obtained raw yarn or spun yarn increases, and the DKS × DKE value of the fiber after dyeing increases again. Anti-pill disappears. If the DKS × DKE value exceeds 40, sufficient anti-pill property cannot be obtained, and even if the DKS × DKE value is 40 or less, if the boiling water shrinkage exceeds 3%, the desired anti-pill property cannot be obtained for the above reason. I can't.

The tensile strength of the fibers obtained according to the invention is between 1.2 and 3 g / d. 1.2g / tensile strength
If it is less than d, the post-processability becomes poor, and if it exceeds 3 g / d, the pill resistance becomes poor.

The fiber thus obtained is subjected to mechanical crimping as it is or appropriately, towed or cut, and led to the next step such as spinning as a stable. The fibers of the present invention can be used for a wide variety of applications, either alone or in admixture with other synthetic or natural fibers.

Although the present invention has been described above, the present invention may employ various other known additional conditions. For example, an inorganic compound such as titanium oxide or aluminum hydroxide, or a non-solvent of an acrylonitrile polymer such as ethylene glycol or the like may be added to the spinning dope, or the method of composite spinning or blend spinning may be applied.

[0024]

The present invention will be further described below with reference to examples and comparative examples. "%" Represents% by weight. The “specific viscosity” was measured at 25 ° C. by dissolving 0.1 g of the polymer in 100 ml of dimethylformamide containing 0.1N rhoda soda. The "anti-pill property" was measured by the following method. J
The test was performed according to the ICI type test method A (60 rpm, 5 hours) specified in IS 1-1076, and the knitted fabric was classified into grades 1 to 5 according to the change in appearance. (Hereinafter, referred to as ICI anti-pill test.) Raw cotton having good anti-pill property means one having a third or higher grade in the ICI anti-pill test. The knitted fabric sample used in the test was spun from raw cotton into a 48th single yarn and subjected to 60-minute boil dyeing at 100 ° C. using 2% owf of dye cationic blue CD, RLH (produced by Hodogaya Chemical Co., Ltd.). A dyed yarn having a knitted fabric of 180 g / m ² was used.

The method for measuring the “steam shrinkage” was as follows. Make a knot at both ends of the fiber bundle about 1.5 m and hang it on a length measuring instrument.
In a state where a load of 5 g is applied, the length between the upper end knot and the lower end knot is measured and is defined as Acm. Next, remove the fiber bundle from the length measuring instrument, put it in the steamer in a free state, and
g / cm ² steam into the steamer at normal pressure
Process for a minute. Then, after cooling the steam-treated fiber bundle with water, the fiber bundle was again placed on a length measuring instrument, and a load of 1.25 g per 100 denier was applied. The length between the upper knot and the lower knot was measured to be Bcm. The shrinkage was calculated according to the equation. Steam shrinkage (%) = [(AB) / A] × 100

Comparative Example 1 Acrylonitrile 93.5
%, Methyl acrylate 6.0% and sodium methallylsulfonate 0.5%, an acrylic copolymer having a specific viscosity of 0.161 was dissolved in dimethylformamide to give a solid content of 3%.
A 0% spinning stock solution was prepared. After heating each of the stock solutions to 130 ° C., it was discharged from a nozzle having various shapes shown in Table 1 having 600 holes and a hole diameter of 0.2 mm into an inert gas heated to 230 ° C., and a spinning speed of 350 m / In minutes, an undrawn yarn was obtained. This undrawn yarn is converged, and 1.8 mm in hot water.
The fiber bundle obtained is stretched twice, further washed in hot water, and then subjected to an oil agent. The obtained fiber bundle is subjected to drying and relaxation treatment at a relative humidity of 40% and a temperature of 150 ° C. under no tension to produce a 480,000 denier fiber bundle. did. Shrinkage was 24-27%. 20 more
After secondary stretching 1.8 times with a hot roller at 0 ° C., the tow which had been heat-set to a fixed length was given an appropriate mechanical crimp and cut into 51 mm. Degree of irregularity of the cross-sectional shape of the obtained fiber, D
Table 1 shows the results of S, DKS × DKE value, steam shrinkage, and ICI anti-pill test. In addition, each single fiber fineness was about 3 denier. No. In Nos. 1 to 3, the cross-sectional shapes of the finally obtained fibers all showed a dumbbell shape with a degree of irregularity of 3 or more, and the anti-pill properties were secondary.

[0027]

[Table 1]

Example 1 Acrylonitrile 93.5%, methyl acrylate 6.0
%, And an acrylonitrile-based copolymer having a specific viscosity of 0.161, comprising 0.5% of sodium methallylsulfonate, was dissolved in dimethylformamide to prepare a spinning dope having a solid content of 33%. After heating each of the above stock solutions to 130 ° C.,
0, a spinning speed of 3 discharged from a nozzle having various hole shapes having a hole diameter of 0.2 mm into an inert gas heated to 230 ° C.
The yarn was spun at 50 m / min to obtain an undrawn yarn. The undrawn yarn is converged, drawn 1.8 times in hot water, washed in hot water and subjected to an oil agent, and the resulting fiber bundle is subjected to 40% relative humidity and 150 ° C under no tension. Drying / relaxation treatment was performed at ℃ to obtain a fiber bundle of 480,000 denier. Shrinkage rate is 24-27%
Met. Further, 1.5-
After a secondary stretching of 1.8 times, the tow which had been heat-set to a fixed length was given an appropriate mechanical crimp and cut to 51 mm. Table 2 shows the results of the irregularity of cross-sectional shape, DS, DKS × DKE value, steam shrinkage and ICI anti-pill test of the obtained fiber. In addition, each single fiber fineness was about 3 denier.

No. In No. 4, the cross-sectional shape of the finally obtained fiber was a dumbbell shape with a degree of irregularity of 3.41 and the anti-pill property was secondary. No. In No. 5, the cross-sectional shape of the finally obtained fiber was Y-shaped with a degree of irregularity of 1.90, and the pill resistance was tertiary. No. In No. 6, the cross-sectional shape of the finally obtained fiber exhibited a Z-shape with a degree of irregularity of 1.60, and the pill resistance was grade 4.

[0030]

[Table 2]

Comparative Example 2 Acrylonitrile 91.1
% And a vinyl acetate of 8.9% and a specific viscosity of 0.175 were dissolved in dimethylformamide to prepare a spinning solution having a solid content of 30% and 33%. After heating each stock solution to 130 ° C., the number of pores is 600, pore diameter is 0.2 m
It was discharged from a nozzle having a circular shape of mφ into an inert gas heated to 230 ° C. and spun at a spinning speed of 350 m / min to obtain an undrawn yarn. The undrawn yarn is converged, drawn 1.8 times in hot water, washed in hot water, and then applied with an oil agent.
%, And dried and relaxed at a temperature of 150 ° C. to obtain a fiber bundle of 480,000 denier. Shrinkage was 32-35%.
Further, after a second stretching of 1.8 times with a hot roller at 200 ° C., a suitable mechanical crimp is applied to the tow which has been heat-set to a fixed length, and the tow is stretched 5 times.
It was cut to 1 mm. Deformity of cross-sectional shape, DS, DKS × DKE value, steam shrinkage and I of the obtained fiber
Table 3 shows the results of the CI anti-pill test. In addition, each single fiber fineness was about 3 denier. No. In Nos. 7 and 8, the cross-sectional shape of the finally obtained fiber was circular with a degree of irregularity of about 1.2, and both of them had a first-class anti-pill property.

[0032]

[Table 3]

Example 2 The spinning dope obtained in Example 1 was
After being heated to 30 ° C., it is discharged into an inert gas heated to 230 ° C. from a nozzle having a cross shape having 600 holes and a hole diameter of 0.2 mm, and spun at a spinning speed of 350 m / min. I got The undrawn yarn is converged and is heated in hot water as shown in Table 4.
After stretching 1.2 to 3.2 times, washing in hot water and then applying oil, the fiber bundle obtained is dried under tension and at a relative humidity of 40% at a temperature of 150 ° C. -The fiber was bundled to 480,000 denier by relaxation treatment. Shrinkage 21
~ 28%. Further, as shown in Table 4, the sheet was subjected to secondary stretching to 1.142 to 1.8 times with a hot roller at 200 ° C., and then a suitable mechanical crimp was applied to the tow which had been heat-set to a fixed length.
m. The degree of irregularity of the cross-sectional shape of the obtained fiber,
DS, DKS × DKE value, steam shrinkage and ICI
Table 4 shows the results of the anti-pill test. In addition, each single fiber fineness was about 3 denier. No. In Nos. 9 to 13, the cross-sectional shapes of the finally obtained fibers were all irregularities.
It exhibited a Z-shape of 6 to 1.7.

[0034]

[Table 4]

[0035]

The anti-pilling acne obtained by the present invention
Ril-based fibers have excellent gloss and anti-pilling properties
Acrylic fiber with high tensile strength and good workability.
Its industrial significance is great.

Continuation of the front page (72) Inventor Koji Nishida 20-1 Miyuki-cho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Works (56) References JP-A-57-121610 (JP, A) JP-A-2- 210016 (JP, A) JP-A-59-116409 (JP, A) JP-A-64-26714 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 6 / 18,6 / 38

Claims (1)

(57) [Claims] 1. A highly concentrated stock solution containing 32-43% by weight of an acrylonitrile-based polymer containing 92% by weight or more of acrylonitrile, the nozzle hole shape of which is triangular, square,
Dry spinning from a nozzle composed of one or a combination of two or more of a cross, a Y-shape, and a star, a primary drawing in a range of 1.2 to 4 times, and then a drying and relaxation heat treatment is performed.
After giving a shrinkage of ４０40% and performing a second stretching at a temperature of 160 to 200 ° C. by a factor of 1.2 to 2.5, a constant-length heat treatment at a temperature not lower than the stretching temperature is performed. 2-3 g / d, the product of the knot strength (g / d) and the knot elongation (%) is 40 or less, the boiling water shrinkage is 3% or less, and the fiber cross-sectional shape irregularity is 2 or less. Manufacturing method of anti-pilling acrylic fiber.