WO2016132877A1

WO2016132877A1 - Method for producing acrylic fiber

Info

Publication number: WO2016132877A1
Application number: PCT/JP2016/052936
Authority: WO
Inventors: 吉村悟; 穴原賢
Original assignee: 株式会社カネカ
Priority date: 2015-02-16
Filing date: 2016-02-01
Publication date: 2016-08-25
Also published as: CN107250449A; CN107250449B; TW201638408A; US20170335491A1

Abstract

The present invention relates to a method for producing an acrylic fiber, wherein a spinning raw material solution obtained by dissolving an acrylic copolymer in an organic solvent is subjected to wet spinning. The acrylic copolymer contains 20-85% by mass of acrylonitrile, 14.5-79.5% by mass of vinyl chloride and 0.5-10% by mass of a sulfonic acid group-containing monomer relative to the total mass of the acrylic copolymer; the organic solvent is dimethyl sulfoxide; and the spinning raw material solution contains water and a condensed phosphate.

Description

Acrylic fiber manufacturing method

The present invention relates to a method for producing an acrylic fiber by wet-spinning a spinning stock solution obtained by dissolving an acrylic copolymer obtained by copolymerizing acrylonitrile, vinyl chloride and a sulfonic acid group-containing monomer in dimethyl sulfoxide.

Acrylic fibers, especially acrylic fibers made of an acrylic copolymer containing vinyl chloride or vinylidene chloride as one of the copolymer components, are used for artificial hair used in hair ornaments such as wigs, hairpieces, and weavings because of their soft touch. It is suitably used as a fiber. Usually, acrylic fibers used as artificial hair are produced by wet spinning using a spinning stock solution obtained by dissolving an acrylic copolymer in a good solvent such as dimethyl sulfoxide. For example, Patent Document 1 describes that an acrylic fiber made of an acrylic copolymer composed of acrylonitrile, vinylidene chloride, and a sulfonic acid group-containing vinyl monomer is described by a wet spinning method using a good solvent. ing.

However, in Patent Document 1, although vinylidene chloride is used as one of the components copolymerized with acrylonitrile, there is a problem that the curl setting property by hot water is poor. Therefore, vinyl chloride is used as one of the components copolymerized with acrylonitrile in order to enhance the curl setting property by hot water.

JP 2002-315765 A

However, the inventors of the present invention use a highly safe dimethyl sulfoxide as a good solvent and spin a solution obtained by dissolving an acrylic copolymer obtained by copolymerizing acrylonitrile, vinyl chloride, and a sulfonic acid group-containing monomer in dimethyl sulfoxide. It has been found that when an acrylic fiber is produced by wet spinning the stock solution, there is a problem that the acrylic fiber is colored yellow or brown.

In order to solve the above problems, the present invention suppresses coloring of the resulting acrylic fiber even when wet spinning a spinning stock solution in which an acrylic copolymer containing vinyl chloride as a copolymerization component is dissolved in dimethyl sulfoxide. Provided is a method for producing an acrylic fiber that can be used.

The present invention relates to a method for producing an acrylic fiber in which a spinning stock solution obtained by dissolving an acrylic copolymer in an organic solvent is wet-spun, and the acrylic copolymer is based on the total mass of the acrylic copolymer. 20% to 85% by weight of acrylonitrile, 14.5% to 79.5% by weight of vinyl chloride, and 0.5% to 10% by weight of the sulfonic acid group-containing monomer, and the organic solvent is dimethyl sulfoxide, The spinning dope includes water and a condensed phosphate, and relates to a method for producing an acrylic fiber.

The spinning dope preferably contains 0.05 to 5% by mass of condensed phosphate with respect to the total mass of the acrylic copolymer.

The condensed phosphate is preferably at least one compound selected from the group consisting of pyrophosphate, tripolyphosphate, tetrapolyphosphate, trimetaphosphate and tetrametaphosphate, and is a tripolyphosphate. It is more preferable.

According to the present invention, there is provided an acrylic fiber in which coloring to a yellow or brown color is suppressed even when a spinning stock solution in which an acrylic copolymer containing vinyl chloride as a copolymerization component is dissolved in dimethyl sulfoxide is wet-spun. be able to.

When the inventors of the present invention wet-spun a spinning stock solution in which an acrylic copolymer containing acrylonitrile, vinyl chloride and a sulfonic acid group-containing monomer is dissolved in dimethyl sulfoxide (DMSO), the acrylic fiber is yellow or yellow. As a result of intensive studies to solve the problem of coloring in brown, the addition of water and condensed phosphate to the spinning dope makes it possible to color acrylic fibers to yellow or brown while having good spinnability. It was found that it was suppressed and led to the present invention. When wet spinning a spinning stock solution in which an acrylic copolymer is dissolved in dimethyl sulfoxide, a dehydrochlorination reaction of the acrylic copolymer occurs in the production process, and the dimethyl sulfoxide is decomposed by the generated hydrochloric acid, so that the fibers are separated. Presumed to be colored yellow or brown. The dehydrochlorination reaction of the acrylic copolymer becomes more prominent when the step of dissolving the acrylic copolymer in dimethyl sulfoxide is performed at a temperature higher than room temperature for a long time. Condensed phosphates are usually used as phosphorus-based flame retardants that improve the flame retardancy of fibers. Surprisingly, in the present invention, acrylonitrile, vinyl chloride, and acrylic acid copolymerized with sulfonic acid group-containing monomers are used. It has been found that the coloring of acrylic fibers to yellow and brown can be suppressed by adding condensed phosphate together with water to a spinning stock solution in which a copolymer is dissolved in dimethyl sulfoxide and performing wet spinning. Although the mechanism by which coloring of acrylic fibers is suppressed by adding condensed phosphate with water to the spinning dope and suppressing the coloring of acrylic fibers is not clear, hydrochloric acid generated by the dehydrochlorination reaction of acrylic copolymers It is presumed that (hydrogen ion) is used for an equilibrium reaction with a phosphate group derived from a condensed phosphate dissolved in water, and the decomposition of DMSO by hydrochloric acid is prevented.

The acrylic copolymer contains 20 to 85% by mass of acrylonitrile, 14.5 to 79.5% by mass of vinyl chloride, and a sulfonic acid group-containing monomer with respect to the total mass of the acrylic copolymer. Contains 0.5 to 10% by mass. In the acrylic copolymer, if the vinyl chloride content is 14.5 to 79.5% by mass, the flame retardancy is good. In the acrylic copolymer, when the acrylonitrile content is 20 to 85% by mass, the heat resistance is improved, and the processing temperature during curl setting can be set appropriately. When the acrylic copolymer contains the sulfonic acid group-containing monomer in an amount of 0.5 to 10% by mass, the hydrophilicity increases and the void ratio decreases. Preferably, the acrylic copolymer includes 20 to 80% by mass of acrylonitrile, 19.5 to 79.5% by mass of vinyl chloride, and 0.5 to 5% by mass of a sulfonic acid group-containing monomer. More preferably, it contains 20 to 75% by mass of acrylonitrile, 24.5 to 79.5% by mass of vinyl chloride, and 0.5 to 5% by mass of a sulfonic acid group-containing monomer.

The sulfonic acid group-containing monomer is not particularly limited, and examples thereof include allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, isoprene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and sodium salts thereof. Such metal salts and amine salts can be used. The said sulfonic acid group containing monomer can be used individually or in combination of 2 or more types.

The above acrylic copolymer is dissolved in dimethyl sulfoxide. Use of dimethyl sulfoxide as the organic solvent increases safety.

From the viewpoint of effectively suppressing the coloring of the acrylic fiber, the spinning dope preferably contains 0.05 mass% or more of the condensed phosphate with respect to the total mass of the acrylic copolymer, and is 0.06 mass. % Or more, more preferably 0.07% by mass or more. The upper limit of the condensed phosphate is preferably 5% by mass or less and preferably 4.5% by mass or less of the condensed phosphate with respect to the total mass of the acrylic copolymer from the viewpoint of coloring prevention and spinnability. Is more preferably 4% by mass or less, further preferably 3.5% by mass or less, further preferably 3% by mass or less, further preferably 2.5% by mass or less, and further preferably 2% by mass. %, More preferably 1.5% by mass or less, further preferably 1% by mass or less, further preferably 0.9% by mass or less, and 0.7% by mass or less. Is more preferable, and more preferably 0.5% by mass or less is included.

The condensed phosphate is not particularly limited as long as it is an inorganic condensed phosphate. For example, pyrophosphate, tripolyphosphate, tetrapolyphosphate, trimetaphosphate, and tetrametaphosphate can be used. Among these, tripolyphosphate is preferable from the viewpoint of availability and high solubility. The kind of salt is not particularly limited, and may be any salt such as sodium salt, potassium salt, and ammonium salt. From the viewpoint of excellent solubility in water, the salt is preferably a water-soluble salt such as a sodium salt or a potassium salt. Examples of pyrophosphate (also referred to as diphosphate) include sodium pyrophosphate and potassium pyrophosphate. Examples of the tripolyphosphate include sodium tripolyphosphate, aluminum dihydrogen phosphate, potassium tripolyphosphate, and the like. Examples of the tetrapolyphosphate include sodium tetrapolyphosphate and potassium tetrapolyphosphate.

From the viewpoint of solubility of the condensed phosphate and spinnability, the spinning dope preferably contains 8 to 16% by mass of water, and preferably 8 to 15% by mass with respect to the total mass of the acrylic copolymer. More preferably, it is contained in an amount of 8 to 14% by mass, more preferably 8 to 13% by mass, and further preferably 8 to 12.5% by mass.

Although the above spinning dope depends on the composition of the acrylic copolymer, for example, the acrylic copolymer is 20 to 30% by mass and DMSO is 65.2 to 78.49% by mass with respect to the total mass of the spinning dope. %, Water 1.5 to 4.8% by mass, and condensed phosphate 0.01 to 1.5% by mass, more preferably 22 to 30% by mass of acrylic copolymer, DMSO 66 to 75.99% by mass, water 2 to 4% by mass, condensed phosphate 0.01 to 1.5% by mass, and more preferably acrylic copolymer 25 to 30% by mass, It contains 66.5 to 72.49% by weight of DMSO, 2.5 to 3.5% by weight of water, and 0.01 to 1.5% by weight of condensed phosphate.

The above spinning dope may contain other additives for improving the fiber characteristics, if necessary, as long as the effects of the present invention are not impaired. Examples of the additives include gloss modifiers such as esters and ethers of cellulose derivatives such as titanium dioxide, silicon dioxide, and cellulose acetate, colorants such as organic pigments, inorganic pigments, and dyes, and improved light resistance and heat resistance. And stabilizers for the above.

The spinning dope is not particularly limited, but can be prepared by mixing an acrylic copolymer, DMSO, water, and condensed phosphate. From the viewpoint of the solubility of the condensed phosphate, the spinning solution is preferably prepared by mixing an acrylic copolymer, DMSO, and an aqueous solution of condensed phosphate. To increase the solubility of the acrylic copolymer, an aqueous solution of DMSO and condensed phosphate is added to the acrylic copolymer, and then stirred at 40 to 80 ° C. for 3 to 12 hours to prepare a spinning dope. It is preferable to stir at 50 to 75 ° C. for 4 to 10 hours, more preferably at 60 to 70 ° C. for 5 to 8 hours. In the preparation of the spinning dope, if a mixture of an acrylic copolymer, DMSO and an aqueous solution of condensed phosphate is treated at, for example, 60 ° C. or more for 5 hours or more, hydrochloric acid is generated by the dehydrochlorination reaction of the acrylic copolymer. However, when hydrochloric acid (hydrogen ion) is used for an equilibrium reaction with a phosphate group derived from a condensed phosphate, decomposition of DMSO by hydrochloric acid is prevented, and the fiber is colored yellow or brown. Presumed to be suppressed. An acrylic copolymer containing water may be used as the acrylic copolymer. In the present invention, when an acrylic copolymer containing moisture (hereinafter, also simply referred to as a water-containing acrylic copolymer) is used as the acrylic copolymer, what is the total mass of the acrylic copolymer? The dry weight of the acrylic copolymer refers to the dry weight of the acrylic polymer obtained by drying the water-containing acrylic copolymer at 60 ° C. for 10 hours and measuring the mass after removing moisture. As DMSO, DMSO containing water may be used. In this specification, unless otherwise indicated, an acrylic copolymer refers to an acrylic copolymer that does not contain moisture, and DMSO refers to DMSO that does not contain moisture.

Acrylic fibers are obtained by wet-spinning the above spinning stock solution by a usual method. For example, first, the above spinning solution is discharged through a spinning nozzle or directly into a coagulating liquid (coagulating bath) made of an aqueous solution of DMSO to coagulate and fiberize. As the coagulation bath, for example, an aqueous solution of DMSO having a DMSO concentration of 40 to 70 mass% can be used, and the temperature can be set to 5 to 40 ° C. If the concentration of a good solvent such as DMSO in the coagulation bath is too low, coagulation is accelerated, the coagulation structure becomes rough, and voids tend to form inside the fiber.

Next, the fiber (coagulated yarn) is led to an aqueous solution of DMSO of 30 ° C or higher or warm water of 30 ° C or higher, which has a DMSO concentration lower than that of the coagulated liquid, and is subjected to solvent removal, washing and stretching, and if necessary, relaxation after stretching. You may do it. After stretching in an aqueous solution of DMSO having a DMSO concentration lower than that of the coagulation liquid at 30 ° C. or higher, it is preferably washed with warm water at 30 ° C. or higher. Remove the solvent by washing with water. The draw ratio is not particularly limited, but is preferably 2 to 8 times, more preferably 2 to 7 times, and further preferably 2 to 6 times from the viewpoint of increasing the strength and productivity of the fiber. preferable. In the solvent removal, water washing, and drawing step in an aqueous solution of DMSO, for example, when the fiber is treated at 80 ° C. or higher for 1 hour or longer, hydrochloric acid can be generated by the dehydrochlorination reaction of the acrylic copolymer. Hydrogen ions) are used for equilibrium reactions with phosphate groups derived from condensed phosphates, and it is assumed that DMSO is prevented from being decomposed by hydrochloric acid, and the fibers are suppressed from being colored yellow or brown. The

Next, the fiber (drawn yarn) may be dried. When drying, an oil agent may be attached as necessary. The oil agent may be any oil agent as long as it is usually used for the purpose of preventing static electricity, preventing fiber sticking and improving the texture in the spinning process, and a known oil agent can be used. The drying temperature is not particularly limited, but is, for example, 110 to 190 ° C., preferably 110 to 160 ° C. Thereafter, the dried fiber may be further stretched if necessary, and the stretch ratio is preferably 1 to 4 times. The total stretching ratio including stretching before drying is preferably 2 to 12 times.

It is preferable that the fiber obtained by further stretching after drying or drying is further subjected to a relaxation treatment of 15% or more. The relaxation treatment can be performed in a dry heat or superheated steam atmosphere at a high temperature, for example, 150 to 200 ° C., preferably 150 to 190 ° C. Alternatively, it can be carried out in a pressurized steam or heated and pressurized steam atmosphere of 0.05 to 0.4 MPa, preferably 0.1 to 0.4 MPa at 120 to 180 ° C.

The single fiber fineness of the acrylic fiber is preferably 30 to 100 dtex, more preferably 40 to 80 dtex, and still more preferably 45 to 70 dtex from the viewpoint of suitable use as artificial hair. Here, the single fiber fineness means an average value of fineness of any 100 single fibers.

The acrylic fiber may contain phosphorus derived from condensed phosphate. For example, phosphorus may be included in an amount of 5 to 250 ppm, 10 to 150 ppm, or 15 to 80 ppm based on the total mass of the acrylic fiber. Phosphorus quantification can be performed as described below.

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example.

(Example 1)
<Spinning stock solution>
In a 7 L stainless steel container, 500 g of an acrylic copolymer composed of 45.7% by mass of acrylonitrile, 52.3% by mass of vinyl chloride, and 2.0% by mass of sodium styrenesulfonate, 1223 g of DMSO, and the concentration 62.5 g of an aqueous solution of 0.61% by mass sodium tripolyphosphate was added, respectively, and stirred at 70 ° C. for 12 hours to dissolve the acrylic copolymer to prepare a spinning dope.
<Spinning conditions>
The obtained spinning solution was wet spun at a spinning speed of 2 m / min in a coagulation bath of a DMSO aqueous solution at 20 ° C. and 57% by mass using a spinning nozzle (pore diameter 0.3 mm, number of holes 50), and then 80 ° C. The film was stretched 3 times in a stretching bath of a 50 mass% DMSO aqueous solution. Subsequently, after washing with warm water of 90 ° C., drying at 140 ° C., stretching twice, and applying a 20% relaxation treatment at 160 ° C., an acrylic fiber having a single fiber fineness of about 46 dtex is obtained. It was.

(Example 2)
The single fiber fineness was about 46 dtex in the same manner as in Example 1 except that an aqueous solution of sodium tripolyphosphate having a concentration of 1.22% by mass was used instead of the aqueous solution of sodium tripolyphosphate having a concentration of 0.61% by mass. An acrylic fiber was obtained.

(Example 3)
The single fiber fineness was about 46 dtex in the same manner as in Example 1 except that an aqueous solution of sodium tripolyphosphate having a concentration of 2.44% by mass was used instead of the aqueous solution of sodium tripolyphosphate having a concentration of 0.61% by mass. An acrylic fiber was obtained.

Example 4
The single fiber fineness was about 46 dtex in the same manner as in Example 1 except that an aqueous solution of sodium tripolyphosphate having a concentration of 3.66% by mass was used instead of the aqueous solution of sodium tripolyphosphate having a concentration of 0.61% by mass. An acrylic fiber was obtained.

(Example 5)
The single fiber fineness was about 46 dtex in the same manner as in Example 1 except that an aqueous solution of sodium pyrophosphate having a concentration of 1.22% by mass was used instead of the aqueous solution of sodium tripolyphosphate having a concentration of 0.61% by mass. An acrylic fiber was obtained.

(Example 6)
The single fiber fineness is about the same as in Example 1 except that an aqueous solution of sodium tetrapolyphosphate having a concentration of 1.22% by mass was used instead of the aqueous solution of sodium tripolyphosphate having a concentration of 0.61% by mass. A 46 dtex acrylic fiber was obtained.

(Comparative Example 1)
An acrylic fiber having a single fiber fineness of about 46 dtex was obtained in the same manner as in Example 1 except that pure water was used instead of the aqueous solution of sodium tripolyphosphate having a concentration of 0.61% by mass.

(Comparative Example 2)
<Spinning stock solution>
In a 7 L stainless steel container, 500 g of an acrylic copolymer composed of 45.7% by mass of acrylonitrile, 52.3% by mass of vinyl chloride, and 2.0% by mass of sodium styrenesulfonate, 1223 g of DMSO, and tripolyphosphoric acid 0.7625 g each of sodium was added and stirred at 70 ° C. for 12 hours to dissolve the acrylic copolymer to prepare a spinning dope.
<Spinning conditions>
The obtained spinning solution was wet spun at a spinning speed of 2 m / min in a coagulation bath of a DMSO aqueous solution at 20 ° C. and 57% by mass using a spinning nozzle (pore diameter 0.3 mm, number of holes 50), and then 80 ° C. The film was stretched 3 times in a stretching bath of a 50 mass% DMSO aqueous solution. Subsequently, after washing with warm water of 90 ° C., drying at 140 ° C., stretching twice, and applying a 20% relaxation treatment at 160 ° C., an acrylic fiber having a single fiber fineness of about 46 dtex is obtained. It was. Two yarn breakage was recognized in the coagulation bath 2 hours after the start of spinning, and the operability was extremely unstable.

The hues of the acrylic fibers of Examples 1 to 6 and Comparative Examples 1 and 2 were measured by the following colorimetry method, and the results are shown in Table 1 below. Further, the phosphorus content in the acrylic fibers of Examples 1 to 6 and Comparative Examples 1 and 2 was measured by the following phosphorus determination method, and the results are shown in Table 1 below. Table 1 below also shows the blending amount of condensed phosphate and the blending amount of water with respect to the total mass of the acrylic copolymer in the spinning dope.

(Fiber colorimetry method)
A sample for color measurement was prepared by making a bundle of 500 fibers 5 mm wide, and using a spectrocolorimeter (“CM-2600d” manufactured by Konica Minolta Co., Ltd.), diffuse illumination 10 °, light receiving method D65, Color measurement was performed at arbitrary four locations under the conditions of a measurement diameter of φ8 mm and the SCE method, and an average value of these measurement values was obtained to obtain a hue.

(Quantitative determination of phosphorus)
Sulfuric acid, nitric acid, hydrofluoric acid and perchloric acid were added to the fiber cut so that the cut length was 0.5 cm, followed by thermal decomposition at 120 ° C. under reflux conditions. After heating and concentrating until white sulfuric acid smoke was produced, it was dissolved by heating at 100 ° C. for 45 minutes with dilute nitric acid and fixed. Using the obtained constant volume solution, phosphorus element was quantified with an ICP emission spectroscopic analyzer (“SPS4000” manufactured by Seiko Denshi Kogyo).

As is apparent from the results in Table 1 above, in wet spinning using a spinning stock solution in which an acrylic copolymer containing acrylonitrile, vinyl chloride and a sulfonic acid group-containing monomer is dissolved in dimethyl sulfoxide, In Examples 1 to 6 containing condensed phosphate, the a value and b value, particularly the b value was 0.5 or more, compared with Comparative Example 1 in which no condensed phosphate was added to the spinning dope. It was low and the coloring of the acrylic fiber was reduced. In addition, although the condensed phosphate was added to the spinning dope, but in Comparative Example 2 where water was not added, as described above, yarn breakage occurred and the spinnability was poor.

Claims

A method for producing an acrylic fiber by wet-spinning a spinning stock solution obtained by dissolving an acrylic copolymer in an organic solvent,
The acrylic copolymer comprises 20 to 85% by mass of acrylonitrile, 14.5 to 79.5% by mass of vinyl chloride, and a sulfonic acid group-containing monomer with respect to the total mass of the acrylic copolymer. Including 0.5-10% by mass,
The organic solvent is dimethyl sulfoxide,
The method for producing an acrylic fiber, wherein the spinning dope contains water and a condensed phosphate.
2. The method for producing acrylic fiber according to claim 1, wherein the spinning dope contains 0.05 to 5% by mass of condensed phosphate with respect to the total mass of the acrylic copolymer.
The acrylic according to claim 1 or 2, wherein the condensed phosphate is at least one compound selected from the group consisting of pyrophosphate, tripolyphosphate, tetrapolyphosphate, trimetaphosphate, and tetrametaphosphate. A method for producing fiber.
The method for producing an acrylic fiber according to claim 3, wherein the condensed phosphate is tripolyphosphate.