JP2009161863A - Anti-pilling acrylic fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-pilling acrylic fiber having an excellent anti-pilling property and a soft hand and having a fine fineness, and to provide a method for producing the anti-pilling acrylic fiber, by which the anti-pilling acrylic fiber can be obtained in high productivity and in good fiber-producing stability. <P>SOLUTION: Provided are the anti-pilling acrylic fiber comprising an acrylonitrile(AN)-based polymer copolymerized with 2 to 4 mol% of an ethylenic vinyl monomer copolymerizable with acrylonitrile (AN) and with 0.1 to 0.4 mol% of a sulfonic group-containing vinyl monomer, and having (1) a single fiber fineness of 0.44 to 0.99 dtex, (2) a tensile strength of 1.4 to 2.6 cN/dtex, (3) a tensile elongation of ≤30%, (4) a knot strength of 1.0 to 1.65 cN/dtex, and (5) a knot elongation of ≤20%; and the method for wet-spinning the fiber in limited fiber-producing conditions. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an anti-pilling acrylic fiber having a fineness that exhibits excellent anti-pilling properties when made into a woven or knitted fabric, and a method for producing the same.

  Acrylic fibers have a soft texture similar to wool, heat retention, bulkiness and excellent dyeability compared to other synthetic fibers, and are often used in the clothing field, interior field, and the like. However, a woven or knitted fabric made of acrylic fibers is practically used when it is used as a garment or the like. There are disadvantages.

  Many proposals have been made in order to improve the drawback of pilling in acrylic fibers. For example, Patent Document 1 discloses a method for imparting anti-pilling properties by using an acrylonitrile-based polymer obtained by copolymerizing a specific amount of a sulfonic acid group-containing vinyl monomer so that fiber orientation is not destroyed by a subsequent heat treatment, Patent In Document 2, an anti-pilling property can be achieved by integrally combining the requirements of the yarn production process, and in Patent Document 3, an acrylonitrile-based polymer obtained by copolymerizing a specific amount of a sulfonic acid group-containing vinyl monomer is used. A method of spinning under a specific condition, and further, Patent Document 4 discloses that a acrylonitrile-based polymer obtained by copolymerization of a specific amount of a sulfonic acid group-containing vinyl monomer is used to spin a fiber under a specific range. A method for physical properties is disclosed.

  However, none of these methods have general versatility, especially when blended with acrylic fiber in wool and made a knitted structure with a loose basis weight in the blended yarn, a satisfactory anti-pilling fiber product cannot be obtained, Furthermore, the conventional methods including these methods have a problem that the productivity of fiber production is low, and even if a high-value-added fiber product is obtained, the cost is very high. Further, the conventional method has a problem that the anti-pilling performance itself is hardly exhibited in a fineness region of less than 1 dtex.

Japanese Patent Publication No.51-34006 Japanese Patent Publication No.57-35285 JP 59-116409 A Japanese Patent Laid-Open No. 9-250024

An object of the present invention is to provide an anti-pilling acrylic fiber having a fineness with excellent anti-pilling properties and soft texture. Further, such an anti-pilling acrylic fiber has a high productivity and a yarn production. It is to obtain good stability.

The gist of the present invention is an acrylic system comprising an acrylonitrile polymer in which 2 to 4 mol% of an ethylenic vinyl monomer copolymerizable with acrylonitrile and 0.1 to 0.4 mol% of a sulfonic acid group-containing vinyl monomer are copolymerized. An anti-pilling acrylic fiber satisfying the following requirements (1) to (5):
(1) Single fiber fineness 0.44 to 0.99 dtex
(2) Tensile strength 1.4 to 2.6 cN / dtex
(3) Tensile elongation 30% or less (4) Knot strength 1.0 to 1.65 cN / dtex
(5) Acrylonitrile heavy copolymerized with 20% or less knot elongation and 2-4 mol% of ethylenic vinyl monomer copolymerizable with acrylonitrile and 0.1-0.4 mol% of sulfonic acid group-containing vinyl monomer. The spinning solution with a polymer concentration of 18 to 25% by mass is made up of a solvent aqueous solution with a solvent concentration of 50 to 60% by mass. After discharging into a coagulation bath having a bath temperature of 40 to 50 ° C. and spinning with a spinning draft of 0.8 to 1.6, it is stretched at a draw ratio of 4 to 5 times in boiling water, and the heat shrinkage ratio at the time of drying and densification is 5 % Anti-pilling acrylic fiber having a heat shrinkage rate of 15% or less by relaxing heat treatment with saturated steam at a temperature of 130 ° C. or less under no tension. It is in.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the acrylic fiber which has the outstanding anti- pilling property and soft texture, and can obtain the fiber product which consists of a woven or knitted fabric of good quality and performance. An anti-pilling acrylic fiber can be obtained with good productivity and stability.

  The acrylonitrile polymer constituting the anti-pilling acrylic fiber of the present invention is composed of 2 to 4 mol% of an ethylenic vinyl monomer copolymerizable with acrylonitrile and 0.1 to 0.4 mol of a sulfonic acid group-containing vinyl monomer. % Is a polymer containing 95.6-97.9 mol% of acrylonitrile copolymerized. If the content of acrylonitrile is less than 95.5 mol%, the heat set property imparted in advance in the spinning process may be significantly reduced in the subsequent high-order processing steps such as dyeing and steaming.

  Examples of the ethylenic vinyl monomer copolymerizable with acrylonitrile include (meth) acrylic acid esters such as methyl acrylate and methyl methacrylate, vinyl acetate, styrene, acrylic acid amide, 2-hydroxyethyl methacrylate, and glycidyl methacrylate. . If the copolymerization amount of the ethylenic vinyl monomer is less than 2 mol%, gelation of the spinning dope tends to proceed during spinning, and process management becomes difficult. If the copolymerization amount exceeds 5 mol%, the fiber tends to shrink. The temperature during the relaxation heat treatment must be lowered so that the thermal contraction rate is 15% or less, and not only relaxation spots are likely to occur but also staining spots are likely to occur.

  Examples of the sulfonic acid group-containing vinyl monomer include allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, isoprene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, or metal salts or amines thereof. When the copolymerization amount of the sulfonic acid group-containing vinyl monomer is less than 0.1 mol%, sufficient dyeing performance is not exhibited, and when it exceeds 0.4 mol%, the stretchability is reduced. Adhesion between single fibers is likely to occur. The acrylonitrile polymer obtained by copolymerizing the ethylenic vinyl monomer and the sulfonic acid group-containing vinyl monomer in the present invention is not particularly limited to the polymerization method, and may be a well-known method, but suspension in an aqueous medium. It is desirable to obtain by a polymerization method.

  The anti-pilling acrylic fiber of the present invention has a single fiber fineness of 0.44 to 0.99 dtex. If the single fiber fineness is less than 0.44 dtex, the stability of the spinning process deteriorates, and the passability of the spinning process also deteriorates. If it exceeds 0.99 dtex, a soft texture cannot be obtained.

Moreover, the anti-pilling acrylic fiber of the present invention needs to have the following fiber properties. That is, it is necessary that the tensile strength is 1.4 to 2.6 cN / dtex, the tensile elongation is 30% or less, the nodule strength is 1.0 to 1.65 cN / dtex, and the nodular elongation is 20% or less.
When the tensile strength is less than 1.4 cN / dtex, the occurrence of fly is increased in the spinning process, and the passability of the process deteriorates. When the tensile strength exceeds 2.6 cN / dtex, the fibers protruding from the spun yarn are not cut. Cause. When the tensile elongation exceeds 30%, the stretched fibers promote the generation of pills.

  Moreover, if the knot strength is less than 1.0 cN / dtex, the passability in the spinning process is deteriorated, and if it exceeds 1.65 cN / dtex, the generated pill is prevented from falling off. Further, even if the knot elongation exceeds 20%, the generated pills are prevented from falling off.

Next, the manufacturing method of the anti-pilling acrylic fiber of this invention is demonstrated.
The anti-pilling acrylic fiber of the present invention comprises an acrylonitrile heavy copolymer in which 2 to 4 mol% of an ethylenic vinyl monomer copolymerizable with acrylonitrile and 0.1 to 0.4 mol% of a sulfonic acid group-containing vinyl monomer are copolymerized. The spinning solution in which the polymer is dissolved in the solvent and the polymer concentration is 18 to 25% by mass is discharged into a coagulation bath composed of an aqueous solvent solution, spun, washed and stretched in boiling water, and dried and densified. Then, it can be obtained by a wet spinning method in which relaxation heat treatment is performed with saturated steam under no tension.
Hereinafter, the conditions in the manufacturing method will be described more specifically.

  In the production method of the present invention, dimethylacetamide is preferably used as a solvent for the acrylonitrile-based polymer in the preparation of the spinning dope. Other solvents for the acrylonitrile polymer are known, such as dimethylformamide and dimethylsulfoxide. When these solvents are used and wet-spun under the spinning conditions in the production method of the present invention, the acrylic fiber of the present invention Not only is it difficult to obtain fiber physical properties, but also spinning stability is poor. The spinning nozzle used for spinning is not particularly limited in terms of the hole shape and the number of holes, but a hole diameter of 0.030 to 0.060 mm is preferable for obtaining fine fibers. If the hole diameter is less than 0.030 mm, hole clogging is likely to occur, and target physical properties are difficult to obtain. If it exceeds 0.060 mm, thread breakage in the coagulation bath is likely to occur.

  In the production method of the present invention, a coagulation bath is important, and the coagulation bath is an acrylonitrile-based polymer solvent, preferably an aqueous solution of dimethylacetamide, and the solvent concentration may be 50 to 60% by mass. is necessary. When the solvent concentration is less than 50% by mass, yarn breakage in the coagulation bath increases and spinnability decreases, and when it exceeds 60% by mass, yarn breakage in the coagulation bath increases and spinning stability deteriorates. The temperature of the coagulation bath is 40-50 ° C. When the bath temperature is less than 40 ° C., the tensile elongation and knot elongation increase and the anti-pilling property decreases, and when it exceeds 50 ° C., the tensile elongation and knot elongation decrease, and the passability of the spinning process deteriorates. .

  The spinning draft at the time of spinning while discharging the spinning solution from the spinning nozzle into the coagulation bath is 0.8 to 1.6, preferably 0.9 to 1.4, and the spinning draft is less than 0.8. Then, the effect of increasing the fiber orientation is small, the knot strength and the knot elongation are increased, and the anti-pilling property is lowered. Spinnability decreases. In addition, the obtained fiber also has a low tensile strength and knot strength, which deteriorates the passability of the spinning process.

  After coagulation in a coagulation bath, the coagulated yarn is drawn at a draw ratio of 4 to 5 while being washed to remove the remaining solvent in boiling water. When drawing in boiling water, if the draw ratio is less than 4 times, sufficient mechanical strength cannot be imparted to the fiber, and if it exceeds 5 times, the fiber orientation advances and the mechanical strength increases. The pilling performance cannot be obtained. After the drawn yarn is treated with an oil bath, it is dried and densified so that the thermal shrinkage during drying and densification is 5% or less. When the shrinkage ratio at the time of drying densification exceeds 5%, the effect of increasing the fiber orientation in advance by setting the spinning draft to 0.8 to 1.6 cannot be maintained, and the orientation relaxation becomes remarkable in the subsequent processing steps. The bending strength is increased and the anti-pilling property is deteriorated.

  The relaxation heat treatment after the drying densification treatment is performed with saturated steam under no tension, but the relaxation heat treatment is performed with saturated steam at a temperature of 130 ° C. or less so that the thermal shrinkage rate is 15% or less. When the saturated steam temperature exceeds 130 ° C., even if the thermal shrinkage rate is 15% or less, the intended fiber properties cannot be obtained, and even if the saturated steam temperature is 130 ° C. or less, the thermal shrinkage rate is If it exceeds 15%, the desired fiber properties cannot be obtained.

  The acrylic fiber obtained by the production method of the present invention is cut into a predetermined length to be a short fiber, and then the staple fiber is used as a spun yarn in the spinning process, but in the spinning process, As long as the effects of the acrylic fiber of the present invention are not impaired, other fibers, for example, acrylic fibers other than the acrylic fiber of the present invention, synthetic fibers such as polyester fibers and nylon fibers, chemical fibers such as rayon, wool, silk It is also possible to make a spun yarn by blending with natural fibers such as cotton.

  Hereinafter, the present invention will be specifically described by way of examples. In addition, the measurement of the fiber physical property and evaluation item in an Example was based on the following method.

(Tensile strength / elongation, knot strength / elongation)
Measured according to the JIS L1015 chemical fiber staple test method, and each is shown as an average value of the measurement times .

(Spinning stability)
Shown by the following evaluation criteria.
○: Good spinnability △: Spinning is possible, but stable production is difficult ×: Unspinable, cannot be evaluated with fibers

(Passing through spinning process)
Shown by the following evaluation criteria.
○: No problem in the process △: Spinning is possible, but stable production is difficult ×: Spinning is impossible, cannot be evaluated on the knitted fabric

(Texture)
It shows by the following evaluation criteria by tactile sense determination.
○: Sufficient soft feeling △: Soft feeling is slightly poor ×: No soft feeling, poor touch

(Anti-pilling property)
It is evaluated by a 5-hour test (ICI method) according to JIS L1076 A method and indicated by a grade.

Example 1
A spinning stock solution in which an acrylonitrile polymer consisting of 97.0% by mole of acrylonitrile, 2.8% by mole of vinyl acetate and 0.2% by mole of sodium methallylsulfonate is dissolved in dimethylacetamide (DMAc), and the polymer concentration is 24% by weight. Was prepared. This spinning dope is discharged into a coagulation bath having a DMAc concentration of 56% by weight and a temperature of 45 ° C. using a spinning nozzle having a pore diameter of 0.045 mm and a pore number of 50000, and spinning with a spinning draft 1.1. Drawing was carried out at a draw ratio of 4.5 times while washing. Next, the oil agent was attached, dried and densified with a 165 ° C. heat roller to a shrinkage rate of 0%, and further subjected to relaxation heat treatment under no tension in a pressurized steam at 110 ° C. to a heat shrinkage rate of 10%, An acrylic fiber having a single fiber fineness of 0.88 dtex (hereinafter simply referred to as acrylic fiber) was obtained. Table 1 shows the tensile strength, tensile elongation, knot strength, and knot elongation of the obtained acrylic fiber. The obtained acrylic fiber was spun by a normal method to produce a spun yarn with a count of 1/52, and then a knitted fabric was knitted with the spun yarn, and the knitted fabric was dyed with a cationic dye by a conventional method. . Table 1 shows the evaluation results of spinning stability, spinning process passability, texture in the obtained dyed knitted fabric, and anti-pilling property in obtaining the acrylic fiber.

(Example 2, Comparative Examples 1-10)
Acrylic fibers having a fineness were obtained by the same wet spinning method as in Example 1 under the polymer compositions and spinning conditions shown in Tables 1 and 2. Tables 1 and 2 show the tensile strength, tensile elongation, knot strength, and knot elongation of the obtained acrylic fibers. Similarly to Example 1, Tables 1 and 2 show the evaluation results of spinning stability, spinning process passability, texture, and anti-pilling property. In Table 2, DMSO means dimethyl sulfoxide.

(Examples 3-6, Comparative Examples 11-14)
Highly shrinkable acrylic fibers (manufactured by Mitsubishi Rayon Co., Ltd., single fiber fineness) were used as the low shrinkable acrylic fibers obtained from the acrylic fibers obtained in Examples 1 and 2, respectively A bulky yarn having a count of 1/42 was prepared by combining 1.7 dtex and a heat shrinkage rate of 18%) and a blending rate (mass%) shown in Table 3. Using this bulky yarn, a knitted fabric was knitted and dyed in a conventional manner with a loose basis weight. Table 3 shows the evaluation results of the texture and anti-pilling property of the obtained dyed knitted fabric.

The anti-pilling acrylic fiber of the present invention, when used as a material for woven or knitted fabric, can impart excellent anti-pilling properties and soft texture to textile products, particularly in clothing applications such as sweaters, underwear, and jerseys. The anti-pilling of the present invention is suitable for use as clothing having anti-pilling properties and soft texture, and is applicable not only to clothing but also to other textile products that require excellent anti-pilling properties and soft texture. It can be used alone or in combination with other fibers. Further, the anti-pilling acrylic fiber of the present invention has good productivity and can be stably produced.

Claims (3)

An acrylic fiber comprising an acrylonitrile polymer copolymerized with 2 to 4 mol% of an ethylenic vinyl monomer copolymerizable with acrylonitrile and 0.1 to 0.4 mol% of a sulfonic acid group-containing vinyl monomer, Anti-pilling acrylic fiber satisfying the requirements (1) to (5).
(1) Single fiber fineness 0.44 to 0.99 dtex
(2) Tensile strength 1.4 to 2.6 cN / dtex
(3) Tensile elongation 30% or less (4) Knot strength 1.0 to 1.65 cN / dtex
(5) Nodule elongation 20% or less   An acrylonitrile polymer copolymerized with 2 to 4 mol% of an ethylenic vinyl monomer copolymerizable with acrylonitrile and 0.1 to 0.4 mol% of a sulfonic acid group-containing vinyl monomer is dissolved in a solvent to obtain a spinning dope. When producing acrylic fibers by the wet spinning method, a spinning stock solution having a polymer concentration of 18 to 25% by mass is discharged into a coagulation bath having a bath temperature of 40 to 50 ° C. composed of a solvent aqueous solution having a solvent concentration of 50 to 60% by mass. And spinning at a draft of 0.8 to 1.6, followed by stretching in boiling water at a stretching ratio of 4 to 5 times, followed by a dry densification treatment with a thermal shrinkage rate of 5% or less during dry densification, The method for producing an anti-pilling acrylic fiber according to claim 1, wherein the heat shrinkage rate is adjusted to 15% or less by relaxing heat treatment with saturated steam at a temperature of 130 ° C or lower under no tension.   The method for producing an anti-pilling acrylic fiber according to claim 2, wherein dimethylacetamide is used as the solvent in the spinning dope and the coagulation bath.