JPH03161505A - Manufacturing method of high water retention acrylic fiber - Google Patents

Abstract

PURPOSE:To obtain the title acrylic fiber useful for clothing, interior application or industrial raw material by discharging an acrylonitrile based polymerization solution from a nozzle having a specific projecting part into a coagulating liquid at a specific rate and then forming the polymer into a fiber. CONSTITUTION:An acrylonitrile based polymer solution is discharged into a coagulating liquid at a ratio of take up rate/discharge linear velocity of 0.45-0.85 using a nozzle A having 3-5 projection parts formed and being 0.8/1.0-1.5/1.0 in ratio of length of projection part to width of projection part. Then the discharged polymer is formed into a fiber to provide the aimed acrylic fiber 1 having microvoid 2, microvoid 3 and opening part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Field The present invention relates to a method for producing acrylic a-fibers having high water retention properties.

(Conventional technology) Acrylic fibers are widely used in the fields of clothing and interior design due to their excellent texture and dyeability. There is a demand for additional functions such as deodorizing properties and deodorizing properties. Functionalization of acrylic fibers is often done by modifying polymers, that is, by copolymerizing polymers, but there are also many methods of treating them with chemicals after shaping the fibers, such as -5 antibacterial, deodorizing, and antifouling, after making them into knitted fabrics. It is said that For these chemical treatments, it is advantageous for the fibers to be processed to have a large surface area and high water retention75, but currently only one fiber that has been designed with these considerations in mind has been introduced to the market. do not have. Several proposals have been made regarding water-absorbing fibers (Japanese Patent Publication No. 60-11-1-24, Japanese Patent Publication No. 61-420).
No. 05, etc.), but these are related to water-absorbing acrylic fibers based on the shape of fine particles, and the fiber design is not suitable for water-retention performance or post-processing using chemicals.
1.Of course, in terms of bulk and heat retention, it is only on the same level as regular acrylic fiber.

Problems to be Solved by the Invention The first object of the present invention is to provide a highly water-retentive acrylic fiber that can easily retain functional chemicals at each stage from the fiber manufacturing process to the knitting and fabric production process. The second purpose is to provide a method for producing bulky acrylic material that is suitable for interior decoration and clothing, and has high heat retention properties and excellent water absorption properties.

Means for Solving the Problems> The main point of the present invention is that when producing acrylic fibers by wet spinning an acrylonitrile polymer, an acrylonitrile polymer solution is poured into three to five rectangular shapes. One side is joined to each other to form 3 to 5 protrusions, and the ratio of the length of the protrusion to the width of the protrusion is (L 8 / 1.0 - t 5
/ to a nozzle, the fiber is discharged into a coagulation liquid so that the linear velocity/linear discharge velocity is CL45 to 0.85, and the method of producing a highly water-retentive acrylic fiber is performed. be.

The present invention will be explained in more detail below.

The most significant feature of the present invention is the g. The fibers have at least macrovoids that are partially open on the side surface of the ram and are substantially continuous in the direction of the pI female axis. This allows external liquid to be quickly introduced into the fibers. Further, by having microvoids dispersed around the periphery, liquid introduced through the macrovoids is distributed to each microvoid, thereby achieving high water retention. Here, "substantially continuous in the fiber axis direction" means that the dimensional force in the fiber axis direction is overwhelmingly larger than the dimension in the cross-sectional direction of the void, and is several tens of times larger than the dimension in the cross-sectional direction. , which means that the poids appear to be continuous. In addition, the macropoid is a large void with a diameter calculated from the cross-sectional area of about 1 μm or more, preferably tL<3 μm or more, and these macrovoids are formed close to the side surface of the fiber. On the other hand, microvoids are smaller than the above, but most have a diameter (L5 μm or less). Macrovoids that are substantially continuous in the fiber axis direction are an important characteristic of the fJ! The liquid absorbed in each part quickly spreads throughout the fa fibers, increasing not only the amount of water retention and water absorption, but also the rate of absorption.Used for clothing and interior decoration. It is possible to improve the moisture permeability when

An example of moth fiber obtained by the present invention is illustrated in FIG. 1st
In the figure, 1 is an acrylic smoked fiber according to the present invention, 2 is a macrovoid, 3 is a microvoid, and 4 is a part of the macropoid that is opened on the side of the fiber above the slit.

The first requirement of the present invention is that 3 to 5 rectangular sides are joined to each other to form 3 to 5 protrusions, and the ratio of the length of the protrusions to the width of the protrusions is 0. 8/1. 0-1. 5 /
1. The method involves discharging an acrylonitrile polymer solution from a nozzle to form a fiber shape. An example of such a nozzle is shown in FIG.

The ratio of the length of the nozzle protrusion to the width of the protrusion is CL8/1.
When it is less than 0, the obtained fiber has a circular cross section.
M. However, the macrovoids are crushed and fibers with sufficiently satisfactory water retention properties cannot be obtained. On the contrary, t 5 /
When t o is exceeded, the obtained elegant cross section retains the original shape of the nozzle and no macro voids are generated. The number of rectangular nozzles is 3 to 5. If the number of rectangles is less than 3, only one macropoid will be formed and sufficient water retention will not be obtained.On the other hand, if the number of rectangles is more than 5, the lf&
．． The fibers become licked fibers of macrovoids. In the acrylic fiber of the present invention, macrovoids are obtained by bonding of parts of the adjacent outer ends of the nozzle in the ft fiber axis direction before the polymer solution discharged from the nozzle is sufficiently solidified. Therefore, even if a part of the rectangular nozzle has a concave shape, a trapezoid, or a nozzle in which one end of a triangle is joined, by appropriately selecting the spinning conditions, the acrylic It &.
It is possible to obtain fiber.

The second requirement of the present invention is that the linear takeoff speed/linear discharge speed (hereinafter referred to as .TB) be set in the range of cL45 to 1185. In obtaining the acrylic fiber of the present invention, J
S is an important factor. ．． If TS is less than 0.45, the cross-sectional shape of the obtained ut miscellaneous material will be circular and the macropoid will be collapsed, making it impossible to obtain fibers with sufficient water retention properties.On the other hand, if Js exceeds CL85, the obtained fibers will become The cross-sectional shape maintains the shape of the nozzle and becomes a fiber with a Y-shaped cross section, a cross cross section, etc.
/-> becomes fiber.

The acrylonitrile polymer used in the present invention means a copolymer containing acrylonitrile as a main component. Unsaturated monomers copolymerizable with acrylonitrile include acrylic acid, methacrylic acid, and derivatives thereof, vinyl acetate, acrylamide, vinyl chloride, vinylidene chloride If
Can be mentioned. Furthermore, depending on the purpose, it is also possible to use an acrylonitrile polymer containing vinylbenzenesulfonic acid, methacrylsulfone, or a salt thereof, or an acrylic acid derivative having a polyethylene glycol component.

The solvent for the acrylonitrile polymer solution is not particularly limited as long as it is a solvent normally used for wet spinning. As these solvents, organic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, and acetone, and inorganic solvents such as concentrated nitric acid, aqueous rhodan salt solutions, and aqueous zinc chloride solutions can also be used. used to advantage.

The degree of polymerization of the acrylonitrile polymer used in the present invention is not particularly limited as long as it is within the range commonly used.

The concentration of acrylonitrile polymer in the polymer solution is ys
It is necessary to set it so that it is α45 to a85,
It is possible to obtain the fineness of the present invention within the general range set for producing acrylic fibers. In the acrylic fiber m obtained by the present invention, a higher water retention rate can be obtained as the concentration of the acrylonitrile polymer in the polymer solution is lower, but on the other hand, the fiber physical properties are lowered. For this reason, it is actually desirable to adjust the polymer concentration appropriately depending on the final use, and to set it in consideration of the balance between water retention and fiber properties.
0 The polymer solution thus obtained is discharged from a spinneret and shaped into fibers, and a wet spinning method is advantageous as a spinning method for obtaining the fibers of the present invention.

The coagulating liquid consists of a solvent and a coagulant, and the solvents mentioned above can be selected as appropriate, but organic solvents are advantageous because of their coagulating properties. As a coagulant, water, methanol, ethylene glycol, etc. can be used, but water is industrially most advantageous. The composition of the coagulating liquid is not particularly specified.
Although it is appropriately controlled depending on the concentration of the polymer solution,
The acrylic fibers of the present invention can be obtained using commonly used fibers. There is no problem as long as the temperature of the coagulating liquid is within the general range for producing acrylic l1i fibers. The obtained coagulated thread is stretched, washed, coated with an oil agent, and then dried.

After drying, the fibers are subjected to thermal relaxation, giving them appropriate performance as acrylic fibers. Water retention rate of raw cotton ffl
The area of the poid portion in the fiber cross section was measured by the following method.

Water retention rate: After immersing fibers refined in a conventional manner in water for 24 hours, the weight (W,) of the raw cotton is measured by stretching and dehydrating the fibers at an acceleration of 1000 G for 10 minutes.

The weight after drying this fiber with hot air at 110℃ for 3 hours (
W, ) is weighed and calculated from the following formula.

##Lm Area of void portion in cross section: #iil photographed with a scanning electron microscope! Randomly choose 5 from the cross-sectional photo of Ususa.
Nl fibers were selected, and the area (A, 1) b and m fiber cross-sectional area (A21) of the void portion occupying the cross section of each fiber were measured and calculated from the following formula.

Example EXAMPLES The present invention will be specifically explained below with reference to Examples.

Example 1 Specific viscosity 1.93 parts by weight of acrylonitrile and 7 parts by weight of vinyl acetate. An acrylonitrile polymer of 75 ([111 dimethylformamide (DMF) solution, 25°C) was dissolved in dimethylacetamide to obtain a spinning stock solution with a solid content concentration of 20% by weight.

By changing the ratio of the length of the protruding part to the width of the protruding part, it was added to a coagulation tank made from dimethylacetamide and water -6x55/a5Nfl4 using a nozzle having the shape shown in Figure 2 (a).J80.60~A65 The fiber was discharged, stretched 5 times in boiling water, washed, dried, and then subjected to moist heat relaxation to obtain a 10 denier fiber. The water retention rate of the obtained fibers and the void area occupied in the cross section of the fibers were calculated. The results are shown in Table 1.

Table Example 2 An acrylonitrile polymer with a specific viscosity of 1.75 ((L14 DMP solution, 25°C) consisting of 93 weight range of acrylonitrile and 7 weight range of vinyl acetate) is dissolved in dimethylacetamide to give a spinning dope with a solid content concentration of 20 weight-il4. This is shown in Figure 2, where the ratio of the length of the protrusion to the width of the protrusion is 1.0 (
55% of dimethylacetamide and water are supplied from the nozzle shown in a).
The TEI was changed and discharged into a coagulation tank consisting of a 745 weight unit, stretched in boiling water, washed, dried, and then subjected to moist heat relaxation.
A fiber of 10 denier was obtained. The water retention properties of the obtained fibers and the area of voids in the cross section of the fibers were calculated. The results are shown in Table 2.

Table 2 Example 3 An acrylonitrile polymer with a specific viscosity of 1.75 ((L14DMF solution, 25°C) consisting of 93 parts by weight of acrylonitrile and 7 parts by weight of vinyl acetate was dissolved in dimethylacetamide to prepare a spinning stock solution with a solid content concentration of 20 parts by weight). This was obtained by using a nozzle shown in Table 6 in which the ratio of the length of the protruding part to the width of the protruding part was 1.0, and the dimethylacetamide and water were 55/45 by weight.
It was discharged into a dry coagulation tank using a JEIα62, stretched in boiling water, washed, dried, and then subjected to moist heat relaxation.
! I got the fiber. The water retention properties of the obtained fibers and the area of voids in the cross section of the fibers were calculated. The results are shown in Table 3.

Table 3 Example 4 Specific viscosity 1.93% by weight of acrylonitrile and 7% by weight of vinyl acetate. 7 s (α+4nuFW liquid, 25℃
) An acrylonitrile polymer was dissolved in dimethylacetamide to obtain a spinning stock solution with a solid content concentration of 20. This was transferred to a coagulation bath with a weight ratio of dimethylacetamide and water of 5 5/4 5 and a temperature of 40°C using the nozzle shown in Fig. 2 (a) in which the ratio of the length of the protrusion to the width of the protrusion was 1.0. Inside J8
[It was spun with 1L62, stretched 5 times in boiling water, washed, dried, and then subjected to moist heat relaxation to obtain a fibre. The water retention rate of the obtained fibers and PII. The areas occupied by the points and holes in the cross section of the roughness were calculated. The results are shown in Table 4.

Effects of the Invention> The fiber according to the present invention has a large number of voids, so it can be used for clothing and interior decoration.
＞It is a highly water-retaining acrylic fiber that can be used not only as elegant products or highly water-absorbing textile products, but also in a wide range of fields, such as industrial materials that contain large amounts of various drugs and utilize their medicinal properties. It is something.

[Brief explanation of the drawing]

FIG. 1 is a model phase diagram showing the fiber cross section of the fiber of the present invention;
FIGS. 2(a) to 2(e) are enlarged plan views showing examples of the shape of the spinning nozzle used in the present invention.

Claims (1)

[Claims] When manufacturing acrylic fibers by wet spinning acrylonitrile polymer, the length and protrusion of 3 to 5 rectangles are bonded to each other to form 3 to 5 protrusions. The width ratio of the part is 0.8
/1.0 to 1.5/1.0 from a nozzle to perform fiber shaping by discharging into the coagulation liquid so that the linear velocity/discharge linear velocity is 0.45 to 0.85. A method for producing highly water-retaining acrylic fiber.