JPH05279912A - Production of antipilling acrylic fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber having a high shrinking property and a high strength by specifying an acrylonitrile polymer, its secondary drawing and the condition of a constant length thermal treatment. CONSTITUTION:The spinning raw solution of a copolymer comprising 95-99.7wt.% of AN, 0.3-5wt.% of a strong acid group-containing monomer and 0-4wt.% of another monoethylenic vinylic monomer is dry-spun, and the spun fiber is subjected to the first drawing treatment in a drawing ratio of 1.5-4 times. The drawn fiber is shrunk at a rate of 10-50% by a drying treatment and a relaxed heat treatment, subjected to the second drawing treatment in a drawing ratio of 1.1-1.8 times, and immediately subjected to a constant length thermal treatment at 160-200 deg.C to lower the steam shrinkage rate at a rate of 20-70% based on the fiber not subjected to the constant length thermal treatment. Thus, the antipilling acrylic fiber having a tensile strength of 1-3g/d, a steam shrinkage rate of >=7%, and the product of the knot strength (god) with the knot elongation (%) of the fiber after treated with boiling water in a magnitude of <=50 is obtained.

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 synthetic fiber having high shrinkability and excellent pill resistance.

More specifically, the present invention relates to a method for producing an anti-pill acrylic fiber having excellent gloss and texture, high shrinkability and high strength obtained by a dry spinning method.

[0003]

2. Description of the Related Art A dry-spun acrylic fiber has excellent luster and texture due to its dense structure and smooth surface, and is widely used as a fiber for high-grade clothing.

However, the main application is the
In the field and the like, in addition to the above-mentioned advantages, it is strongly required to have anti-pill property and bulky property.

In acrylic fibers, as a method for improving the bulkiness due to high shrinkage and anti-pill property,
As can be seen in JP-A-61-2909, by selecting specific spinning conditions by a wet spinning method, a fiber cross section close to a circle is obtained, the entanglement of single fibers is reduced, and at the same time, a knot before and after boiling water treatment is obtained. A method is disclosed in which high contractility and anti-pill resistance are combined by suppressing the strength and elongation to a low level.

However, since the acrylic fibers generally obtained by the wet spinning method have a hard texture and poor gloss, the above method further hardens the texture by making the cross section of the fiber closer to a circular shape, which is excellent for the purpose of the present invention. It is not possible to obtain an anti-pill acrylic fiber having both gloss, texture and high shrinkability.

The inventors of the present invention provide an acrylic fiber having a high anti-pill property in a dry spinning method which has been difficult to obtain an anti-pill property due to its dense structure by defining a polymer composition and a yarn physical property. Proposed method (Japanese Patent Application No. 3-
No. 27027), but fibers having high shrinkage have not yet been obtained.

[0008]

DISCLOSURE OF THE INVENTION The object of the present invention is to obtain a dry acrylic fiber, which is widely favored by consumers as a high-grade clothing fiber, without impairing its excellent luster and texture, which is difficult to achieve in the past. An object of the present invention is to provide a method for stably producing an anti-pilling acrylic fiber having both high shrinkability and high strength, which is stable in the process.

[0009]

The gist of the present invention is that 95 to 99.7% by weight of acrylonitrile, 0.3 to 5% by weight of a strong acid group-containing monomer, and other copolymerizable with acrylonitrile. Of the acrylonitrile polymer obtained by polymerizing a monomer mixture consisting of 0 to 4% by weight of the monoethylenic vinyl monomer, is dry-spun.
The obtained fiber is primarily stretched in the range of 1.5 to 4 times, then subjected to drying and relaxation heat treatment to give a shrinkage of 10 to 50%, and further stretched 1.1 to 1.8 times under moist heat. Immediately after
A constant length heat treatment at 160 to 200 ° C. to reduce the steam shrinkage rate before the constant length heat treatment by 20 to 70%, a tensile strength of 1 to 3 g / d, and a steam shrinkage rate of 7%.
The product (X) of the knot strength (unit: g / d) and the knot elongation (unit:%) after the above boiling water treatment (X) is 50 or less.

The fiber obtained by the method of the present invention has a knot strength (hereinafter abbreviated as DKS) and a knot elongation (hereinafter DKE).
(X = DKS × DKE) shows a low value even after the boiling water treatment.

The X value of the highly shrinkable fibers produced by the conventional dry spinning method after boiling water treatment is usually 50 to 100, but the X value of the fibers obtained by the method of the present invention after boiling water treatment is It is 50 or less.

Further, the tensile strength (DS) of the fiber obtained by the present invention is 1 to 3 g / d, and the steam shrinkage is 7% or more.

Since the fiber obtained by the conventional dry spinning method has a low steam shrinkage of 5% or less, the bulkiness after boiling water treatment cannot be obtained. On the other hand, when high shrinkage is imparted by a known secondary stretching method and fibers having a steam shrinkage of 7 to 25% are obtained, a decrease in the anti-pill property after boiling water treatment of the fibers cannot be avoided. However, it is difficult to combine a high steam contraction rate and a high anti-pill property.

The present invention is, for the first time, a feature of the dry spinning method by using a specific acrylonitrile-based polymer, and by combining secondary stretching at a specific draw ratio, and immediately after that, a fixed length heat treatment at a specific temperature. It is characterized in that an anti-pilling acrylic fiber having high shrinkage and high strength can be stably obtained in the process while maintaining excellent gloss and texture.

The acrylonitrile-based copolymer used in the present invention is 95 to 99.7% by weight of acrylonitrile, 0.3 to 5% by weight of a strong acid group-containing monomer, and other monoethylenic copolymerizable with acrylonitrile. The main component is an acrylonitrile polymer obtained by polymerizing a monomer mixture of 0 to 4% by weight of a vinyl monomer.

When the amount of the strong acid group-containing monomer is less than 0.3% by weight, the dyeability is insufficient. On the contrary, when it exceeds 5% by weight, dyeing spots due to excessive dyeability occur. , Not suitable for clothing.

The content of the other monoethylenic vinyl monomer having copolymerizability with acrylonitrile is 0 to 4% by weight, preferably 0 to 2% by weight. If it exceeds 4% by weight, the anti-pill property after boiling water treatment is remarkably reduced, and the desired fiber having a high anti-pill property cannot be obtained.

Specific examples of the strong acid group-containing monomer include (meth) acrylic acid, (meth) allylsulfonic acid, vinylbenzenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and salts thereof. Can be mentioned.

The method for producing the above-mentioned polymer is not particularly limited, and it can be produced by any method such as suspension polymerization, solution polymerization and emulsion polymerization. The degree of polymerization of the polymer is not particularly limited, but the specific viscosity is 0.1
The range of from 0.2 to 0.2 is preferable from the viewpoint of yarn physical properties such as yarn strength, stock solution, and passing property in the spinning process.

The polymer spinning stock solution is prepared by dissolving the polymer in a solvent of a usual acrylonitrile polymer such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, etc. so that the polymer concentration is usually 20 to 40% by weight. To be done.

From the aspects of polymer solubility and solvent recovery, dimethylformamide is particularly preferred.

As the dry spinning method, a conventionally known method can be adopted. For example, the above spinning stock solution is discharged into high temperature air or an inert gas through an orifice to evaporate the solvent and to form an undrawn yarn. obtain.

The undrawn yarn is primarily drawn in the range of 70 ° C to 1.5 to 4 times in hot water. If the stretching temperature is lower than 70 ° C, sufficient stretchability and washability cannot be obtained.

If the primary draw ratio is less than 1.5 times, even if the secondary draw ratio is increased, sufficient strength is not imparted to the obtained fiber, while if it exceeds 4 times, the secondary draw ratio is increased. The fiber obtained after drawing has a high DS and the pill resistance is poor.

The undrawn yarn is washed in hot water at the same time as or before and after the above drawing treatment. Hot water temperature is 80 ~
100 ° C. is preferred. The residual solvent amount after washing is usually 2% by weight or less.

The stretched and washed fiber bundle is then dried and relaxed. Drying usually has a surface temperature of about 115-1
A typical method is to pass under heat on a heat roll at 50 ° C. In this case, densification of the fibers is also achieved at the same time.

It is also possible to carry out relaxation heat treatment at the same time as drying. In this case, the yarn after hot water drawing is kept in a wet state without tension and the relative humidity is about 10 to 40% and the temperature is 110 to 16.
Treatment in heated air in the range of 0 ° C. is preferred.

Further, as another method of relaxation heat treatment, the once dried yarn is subjected to a temperature of about 100 to 140 ° C.
The method of heat treatment in the above pressure steam is also simple and effective.

By heat treatment such as the method described above
Gives ~ 50% shrinkage. This relaxation shrinkage treatment imparts basic properties such as dyeability and morphological stability required for clothing fibers.

When the shrinkage ratio is less than 10%, sufficient dyeability is not obtained. On the contrary, when the shrinkage ratio exceeds 50%, the fiber finally obtained through the subsequent process of the present invention is obtained. The X value after boiling water treatment becomes too high, leading to a decrease in the anti-pill property.

The dried and relaxed fiber bundle is secondarily stretched in the range of 1.1 to 1.8 times under moist heat. By this treatment, the high shrinkability that is the object of the present invention is obtained, the DS of the fiber is further improved, and good post-process passability such as spinning is secured.

When the secondary draw ratio is less than 1.1, the steam shrinkage of the finally obtained fiber does not reach 7%,
The desired high shrinkage cannot be obtained. On the other hand, if it exceeds 1.8, yarn breakage occurs, which is not preferable.

The secondary stretched yarn is immediately subjected to 160-2.
A constant length heat treatment at 00 ° C. is performed to reduce the steam shrinkage rate before processing by 20 to 70%.

When the treatment temperature is lower than 160 ° C., the decrease in steam shrinkage before and after the constant-length heat treatment is as small as less than 20%, and an increase in X value after boiling water shrinkage is unavoidable, but generally high. To obtain the anti-pill property, a high secondary draw ratio is required, and when the anti-pill property is imparted, the steam shrinkage of the obtained fiber becomes too large, and there is a problem in the process passability. Cause

On the other hand, when the treatment temperature exceeds 200 ° C., the decrease in the steam shrinkage ratio before and after the constant-length heat treatment exceeds 70%, and the final steam shrinkage ratio 8 which is the object of the present invention is 8 %
The above high shrinkage cannot be obtained.

The time required for the constant length heat treatment depends on the yarn thread
The time is usually several seconds to several tens seconds, although it is appropriately selected depending on the talden, the secondary stretching ratio, and the secondary stretching treatment speed.

Further, even when the secondary draw ratio and the heat treatment temperature are within the above ranges, when the DS of the obtained fiber exceeds 3 g / d or the X value after boiling water treatment exceeds 50, The anti-pill property after boiling water treatment is remarkably reduced, and the high anti-pill property targeted by the present invention cannot be obtained.

The fibers thus obtained are subjected to mechanical crimping as they are or in the state of tow or cut to be guided as staples to the next step such as spinning.

The fibers obtained by the present invention can be used in a wide variety of applications, either alone or mixed with low-shrinking acrylic fibers or other synthetic fibers or natural fibers.

Although the basic conditions of the present invention have been described above, various known additional conditions may be adopted in addition to the above.

For example, an inorganic compound such as titanium oxide or aluminum hydroxide, water, a non-solvent of an acrylonitrile polymer such as ethylene glycol, or the like is added to the spinning dope, or a technique of composite spinning or blend spinning is applied. You can do it.

The present invention will be specifically described below with reference to examples. In the examples, "%" represents% by weight.

"Specific viscosity" means 0.1 g of the polymer is 0.1
Dimethylformamide containing N rodan soda 10
It melt | dissolved in 0 ml and measured at 25 degreeC.

The "anti-pill property" was measured by the following method. The test was performed according to the ICI type test method A method (60 rpm, 5 hours) defined in JIS I-1076, and the knitted fabric was classified into 1 to 5 grades based on the change in appearance. (Hereinafter, referred to as ICI anti-pill test.) Raw cotton having good anti-pill property means grade 3 or higher in the ICI anti-pill test. The knitted fabric sample used for the test was made by spinning a raw cotton into a No. 48 single yarn, and used as a dye, Cation Bull-CD. 2% owf of RLH (Hodogaya Chemical Co., Ltd.) was used for boil dyeing at 100 ° C. for 60 minutes to make a knitted fabric of 180 g / m ² .

The method of measuring "steam shrinkage" was as follows. Create a knot at both ends of the fiber bundle of about 1.5 m and hang it on a length measuring machine. 1.2 per 100 denier at the bottom knot.
The value measured from the knot at the upper end to the knot at the lower end with a load of 5 g is taken as A (unit: cm).

Next, the fiber bundle is removed from the length measuring device, put in a steamer in a free state, and a steam of 5 kg / cm ² is blown into the steamer and treated for 3 minutes under normal pressure. Then
After cooling the steam-treated fiber bundle with water, it was placed on the length measuring device again, and a value of 1.25 g per 100 denier was applied, and the length between the top knot and the bottom knot was measured. The shrinkage rate was calculated according to the following formula, where B (unit: cm).

[0047]

[Equation 1]

[0048]

【Example】

<Experimental Examples 1 to 18> An acrylic copolymer having an acrylonitrile component of 98.8%, a methallylsulfonic acid soda component of 1.2% and a specific viscosity of 0.194, which was obtained by aqueous suspension polymerization at 50 ° C. Was dissolved in dimethylformamide to prepare a stock solution having a solid content concentration of 25%.

After the above stock solution was heated to 130 ° C., the number of holes was 6
No. 00, an orifice having a hole diameter of 0.2 mmφ was discharged into an inert gas heated to 200 ° C. to obtain an undrawn yarn at a spinning speed of 350 m / min.

This unstretched yarn was bundled, drawn in hot water under the conditions shown in Tables 1 and 2, washed in hot water, and subjected to an oiling agent. Below relative humidity 1
Drying / relaxation treatment was performed at 0% and a temperature of 160 ° C. to obtain a fiber bundle of 480,000 denier.

Further, immediately after secondary stretching under the conditions shown in Tables 1 and 2 under moist heat, a constant length heat treatment was performed with a heat roll. The total contact length of the heat roll is 3 m, and the processing speed is 7
It was 0 m / min. Furthermore, about 8% of mechanical crimp is applied to the toe by a stuffing type crimper,
Cut into

Process passability during production, DS of the obtained fiber, steam shrinkage, X value after boiling water treatment and ICI
The results of the anti-pill test are shown in Tables 1 and 2.

<Experimental Examples 19 to 22> Acrylonitrile component 93.5% obtained by aqueous suspension polymerization at 50 ° C.,
An acrylic copolymer having a specific viscosity of 0.161 and comprising 6.0% of a methyl acrylate component and 0.5% of a methallyl sulfonic acid soda component was dissolved in dimethylformamide to prepare a stock solution having a solid content concentration of 30%. It was adjusted.

An undrawn yarn was obtained from the above stock solution in the same manner as in Experimental Example 1. The unstretched yarn was bundled, drawn 2.0 times in hot water, further washed in hot water and subjected to an oiling agent, and then the obtained fiber bundle was tension-free at a relative humidity of 10% and a temperature of 10%. It was dried and relaxed at 160 ° C. to obtain a fiber bundle of 480,000 denier.

Further, under the conditions shown in Table 3 in the same manner as in Experimental Example 1, a constant length heat treatment was performed immediately after the secondary stretching under moist heat. The total contact length of the heat roll was 3 m, and the processing speed was 70 m / min. Further, in the same manner as in Experimental Example 1, about 8% of mechanical crimp was applied to the tow and cut to 51 mm.

Process passability during production, DS of the obtained fiber, steam shrinkage, X value after boiling water treatment and ICI
The results of the anti-pill test are shown in Table 3.

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a process-stable method for producing an anti-pilling acrylic synthetic fiber having excellent gloss, texture and high shrinkage, which has not been obtained by conventional acrylic fibers. Next, bulk key, etc.
It can be expected to have a wide range of applications in clothing, centering on areas where sex is required, and its industrial significance is great.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Nishida 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Office

Claims (1)

[Claims] 1. Acrylonitrile 95 to 99.7% by weight, strong acid group-containing monomer 0.3 to 5% by weight, and other monoethylenic vinyl monomer 0 to 4% by weight copolymerizable with acrylonitrile. % Of the acrylonitrile polymer obtained by polymerizing a monomer mixture consisting of 10% by dry spinning, and the obtained fiber is primarily stretched in a range of 1.5 to 4 times, and then subjected to drying and relaxation heat treatment. 10-50%
Immediately after the secondary stretching of 1.1 to 1.8 times under moist heat, a constant length heat treatment is performed at 160 to 200 ° C. to obtain a steam shrinkage ratio of 20 to 70% before the constant length heat treatment. Tensile strength of 1 to 3 g / d, steam shrinkage of 7% or more, and knot strength after boiling water treatment (unit: g / g)
A method for producing an anti-pilling acrylic fiber having a product (X) of d) and knot elongation (unit:%) of 50 or less.