JPS6065109A - Porous acrylonitrile synthetic fiber - Google Patents

Abstract

PURPOSE:To provide the titled acrylic synthetic fiber composed of a specific acrylonitrile copolymer and cellulose acetate, containing macro-pores, and having excellent water-absorptivity and yarn quality. CONSTITUTION:The objective acrylic synthetic fiber is composed of (A) 70- 98(wt)% acrylonitrile copolymer containing >=80%, preferably 85-93% acrylonitrile unit and copolymerized with 0.3-1.2% monomer having sulfonic acid group or sulfonic acid base, such as styrenesulfonic acid, etc. and (B) 30-2% cellulose acetate. The fiber contains macropores having a pore surface area A of <=15m<2>/g, a void ratio V of 0.05-0.75cm<3>/g, V/A of >=1/30, and suppressed minute void content. The component B is preferably dispersed in a stripe-pattern along the fiber axis.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to porous acrylic synthetic fibers. More specifically, it relates to a porous acrylic synthetic fiber that suppresses the presence of microvoids and eliminates large pores.

Conventional technology Natural fibers such as cotton, wool, and silk have a water absorbency of 20 to 40%, and can sufficiently absorb sweat generated from the human body, making it comfortable to wear, but synthetic fibers have antistatic properties. In terms of commercial value, it is inferior to natural fibers in that it lacks elasticity and hygroscopicity, as well as lacks water and sweat absorption properties. If underwear, socks, blankets, bedding, sportswear, etc. do not have water- or sweat-absorbing properties, sweat emitted from outside the body will condense and adhere to the clothing surface, causing a sticky feeling, a cold feeling, and a decline in body temperature regulation. The blade is unavoidably uncomfortable when worn.

Various improvements have been made in the past in order to solve the problem of the lack of water and sweat absorption in synthetic fibers. Most of the improvement methods involve forming minute pores in the fibers or forming irregularities on the fiber surface. For example, JP-A-47-25418, JP-A-47-15901, JP-A-48-6649, and JP-A-48-6.
Publication No. 650 describes swelling r during the manufacturing process of acrylic fibers.
A method is described for producing porous acrylic fibers by selecting mild drying conditions to leave minute voids or microvoids in the fiber. Furthermore, Japanese Patent Application Laid-open No. 47-25416, Japanese Patent Publication No. 48-8285, and Japanese Patent Publication No. 48-8286 disclose a method of filling swollen gluten with a water-soluble compound during the manufacturing process of acrylic fibers, drying, and post-treatment. It is described that the filling is ejected after the process and the void is regenerated.

What the above methods have in common is that they aim to produce porous acrylic fibers in which the microorganisms originally contained in the swollen glucose during the production process of acrylic fibers remain in the final product.

The microvoids contained in this swollen pore are extremely unstable thermally. Because of this, it is not possible to perform high-temperature treatment in the fiber manufacturing process, especially during drying, shrinkage, and crimp-setting processes, resulting in poor heat resistance, shape retention, and crimp stability of the final product, which significantly reduces the commercial value of the product. .

The voids in the obtained product A have a void radius lO~100
It is extremely small at 0A. Because these microvoids are contained in countless numbers evenly throughout the fiber, the fiber has many drawbacks such as low strength and elongation, poor gloss, and dull color after dyeing.

In addition, because countless microscopic voids uniformly exist, the heat resistance of the fiber is poor, and during high-temperature dyeing, steaminder treatment, ironing, etc., the voids disappear, resulting in decreased water absorption, changes in color, and poor shape retention. Decrease in blade weight 5- Significant deterioration in quality is observed.

Furthermore, attempts to make these microvoids exhibit water absorbing properties are not effective because the microvoids tend to exist independently of each other and are difficult to act as channels for absorbing water into the fibers. That is, in order for the microvoids to have a certain degree of water absorption, a considerable microvoid content of 1.0 mm is required, and this has the disadvantage of further deteriorating the fiber stability and lowering the commercial value. Conventionally, texture has been improved by spinning a mixture of cellulose acetate-acrylic polymer or cellulose acetate-modacrylic copolymer.
Attempts have been made to improve dyeability. For example, Tokuko Showa 3
Japanese Patent Publication No. 1-968 and Japanese Patent Publication No. 33-2317 describe a method for producing fibers with improved υ, dyeability, and texture from a spinning stock solution in which cellulose acetate is mixed with a modacrylic copolymer. The fibers prepared by this method are
No fibers have been obtained that are sufficiently dense and have water absorption properties with capillary-like macromaids inside the fibers.

Amata, Japanese Patent Publication No. 39-14029 discloses an acrylonitrile copolymer containing 857 moles or more of acrylonitrile, 0.2 mole or more of an ethylenically unsaturated monomer having a sulfonic acid group or a sulfonic acid group, and cellulose acetate. Disclosed is a method for producing dense and dyeable fibers by spinning a spinning solution prepared by dissolving the above in methylformamide or dimethyl sulfoxide into an aqueous spinning bath. Japanese Patent Publication No. 39-14029 describes a fiber made of polyacrylonitrile, that is, a homopolymer of acrylonitrile, and cellulose acetate as a comparative example, and while this fiber has both micro voids and macro voids, the sulfone There is no description of the macroscopic structure of dense and dyeable fibers made from acrylonitrile copolymers containing acid groups or sulfonic acid groups.

Industrial Chemistry Magazine Vol. 72, No. 5, pp. 1186-1188 (196
9) also contains a research report with almost the same contents as the above-mentioned invention described in Japanese Patent Publication No. 39-14029.

Furthermore, Japanese Patent Publication No. 39-14030 describes a procedure for adding cellulose acetate during polymerization of an acrylic polymer as a method for mixing cellulose acetate.
If cellulose acetate is added during polymerization of an acrylic polymer, the heat resistance of the spun yarn will decrease due to cellulose acetate's denaturation, which may cause trouble during the fiber manufacturing process. I can't get enough of it either. On the other hand, Japanese Patent Publication No. 44-11969 and Japanese Patent Application Publication No. 1180-1980
No. 27 and JP-A No. 50-118026 disclose that cellulose acetate or cellulose acetate and titanium oxide are finely dispersed in an acrylic polymer or a modacrylic polymer to form animal hair-like fibers. Although what is intended to be obtained is described, porous fibers with high water absorption properties as obtained in the present invention have not been obtained.

Furthermore, the patent application filed in 1983-4, which corresponds to the so-called earlier application of the present application,
The specification of No. 47-3 (Japanese Unexamined Patent Publication No. 54-101920) describes a microporous structure consisting of 90% by weight or more of acrylonitrile thread 1 and less than 10% by weight of a heat-resistant/void stabilizer such as cellulose acetate. Microporous acrylic fibers are described that have a 100% water absorption capacity and have improved water absorption properties.

However, for reasons of power, the specification of Japanese Patent Application No. 53-4473 only describes microporous acrylic fibers having many microvoids, and fibers with suppressed microvoids and containing giant pores are Not listed.

9- Problems to be solved by the invention As mentioned above, the conventional method can only yield microporous acrylic synthetic fibers containing a large number of microvoids, which have good force and water absorption properties, good heat resistance, It is not possible to produce porous acrylic synthetic fibers that are dyeable and glossy. The present inventors completed the present invention as a result of intensive research in order to improve these drawbacks.

Means and Action for Solving the Problems An object of the present invention is to provide a porous acrylic synthetic fiber that has excellent water absorbency and good thread quality.

That is, the present invention provides (α) an acrylonitrile system containing at least 8 ON amount of acrylonitrile units and copolymerized with 0.3 to 1.2% by weight of a copolymerizable monomer having a sulfonic acid group or a sulfonic acid group; (b) The surface area A of the pores is 15 m"/f or less, and the porosity V is 0.05 to 0.05. A porous acrylic synthetic fiber characterized by having a diameter of 0.75 crn"/t, a V/A of 1/30 or more, and (C) suppressing the presence of microvoids and containing giant pores. It is.

According to the present invention, the porous acrylic synthetic fiber of the present invention comprises 2 to 30 parts by weight of cellulose acetate described in (b) above and 70 to 70 parts by weight of an acrylonitrile copolymer (hereinafter referred to as an acrylic copolymer). 98 parts by weight of a polymer consisting of 1
An organic solvent solution containing 5 to 35% by weight is spun into a coagulation bath, and the fibers in a water-swollen state are first stretched 2.5 to 8 times to a water content of 1.0% by weight at a temperature of 100 to 180°C. It can be produced by drying the film until it becomes 3-fold or less, and then secondly stretching it by a factor of 3 times or less using wet heat. The acrylic synthetic fiber of the present invention contains 2 to 30% by weight of cellulose acetate, preferably 3 to 20% by weight, and 70 to 9% by weight of acrylic copolymer.
It consists of 8 parts by weight, preferably 80 to 97 parts by weight.

The cellulose acetate applied to the present invention is not particularly limited, but usually has a degree of acetylation of 48 to 63% and an average degree of polymerization of 50 to 300.
belongs to.

Further, the acrylic polymer used in the present invention contains at least 80% by weight, preferably 85 to 93% by weight of acrylonitrile units, and has 0.3 to 1.2% by weight of sulfonic acid groups or sulfonic acid groups. It is a product obtained by copolymerizing monomers that can be copolymerized.

Copolymerizable monomers having sulfonic acid or sulfonic acid groups include, for example, styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and salts thereof, with allyl sulfonic acid or methallyl sulfonic acid and salts thereof being particularly preferred. . By copolymerizing these at 0.3 = 1.2% by weight, it not only improves the dyeability, but also suppresses the decrease in heat resistance by suppressing the generation of countless minute voids. Porous fibers having many pores and excellent water absorption properties can be obtained. Examples of copolymerizable monomers other than sulfonic acid or sulfonic acid group-containing monomers include alkyl esters of acrylic acid or methacrylic acid such as methyl acrylate, methyl methacrylate, and ethyl acrylate; amides such as acrylamide and methacrylamide; and their N-monosubstitution or NN-
Examples include disubstituted amides and vinyl acetate.

The acrylic synthetic fiber of the present invention has cellulose acetate 2 to 30%
Parts by weight preferably 3 to 20 parts by weight and 70 to 98 parts by weight of the ar-13-acrylic polymer preferably 80 to 97 parts by weight
For example, an organic solvent solution containing 15 to 35% by weight, preferably 17 to 30 parts by weight, of a polymer consisting of
℃ or less, preferably 25℃ or less, more preferably 25℃ or less
It is manufactured by spinning into a coagulation bath at 0°C or lower. The spun yarn is then first drawn, dried, and second drawn as described below.

If the amounts of cellulose acetate and acrylic polymer exceed the above ranges, acrylic synthetic fibers with excellent water absorbency and thread quality cannot be obtained. Furthermore, if the concentration of the polymer is less than 15% by weight, not only the production cost becomes relatively high, but also voids occur and strength and elongation decrease. On the other hand, if it exceeds 35% by weight, the workability and spinnability will decrease due to an increase in viscosity, and the yarn quality will also decrease, so it must be avoided.

The organic solvent for dissolving the polymer is -14
- Common solvents for cellulose acetate and acrylic polymers are used, but organic solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and ethylene carbonate are usually preferred in terms of solvent recovery and purification.

As the coagulation bath, aqueous solutions of organic solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and ethylene carbonate, and organic solvents such as propyl alcohol and kerosene can be used, but especially organic solvents used as core agents for polymers can be used. Aqueous solutions of solvents are preferred.

Water may be added to the spinning dope in a range that does not cause gluing of the spinning dope. This addition of water is effective in adjusting the viscosity of the spinning dope and suppressing the generation of microvoids in the spun yarn.

Also, a very interesting point is that the striated dispersion form of cellulose acetate in the spun fibers is anisotropic depending on the moisture content of the spinning dope.

That is, when the water content in the spinning dope is increased, the streak-like dispersed form of cellulose acetate becomes more slender and potassium, and conversely, when the water content decreases,
It appears to have a nearly spherical shape.

Similar results are obtained depending on the viscosity of the spinning dope.

Spinning may be carried out under the same conditions as for ordinary acrylic synthetic fibers, and the fibers are sequentially stretched and washed through several baths.

The spinning draft may be set under normal conditions, but a lower one is preferable in order to suppress the generation of microvoids. Further, the temperature of the coagulation bath is preferably lower, for example, 30° C. or lower as mentioned above.

When the temperature exceeds 30° C., there is a greater tendency for a large number of microdits to occur, and the yarn quality and quality of the obtained fibers are significantly reduced. - The subsequent stretching ratio is 2.5 to 8 times, preferably 3 to 6 times. If the stretching ratio is less than 2.5 times,
Due to insufficient stretching and orientation of the fibers, the strength is low and the fibers crack, which must be avoided. On the other hand, if it exceeds 8 times, densification progresses too much and sufficient water absorbency cannot be obtained, resulting in a decrease in operability and must be avoided.

In yarns that have been subjected to primary stretching, the pores generated by the linear dispersion of cellulose acetate and the phase separation from the acrylic polymer are usually more clearly defined. Moreover, ordinary swollen gluten is not preferable in this fiber because it deteriorates the heat resistance, dyeability, gloss, etc. of the fiber originally contained therein. For this purpose, fibers containing a mixture of micro-id and large voids (macro voids, giant pores) are dried to eliminate the micro-id. In this case, the drying conditions are a temperature of 100 to 180°C and a moisture content of 1. By drying to a concentration of 0.0% by weight or less, only the microvoids can be eliminated, leaving large-sized voids due to phase separation.

If the drying temperature is less than 100° C., the microvoids present in large numbers on the acrylic polymer side will not be completely burned out, resulting in a decrease in the strength and elongation of the yarn, and a decrease in gloss dyeability and heat resistance. In addition, temperatures exceeding 180°C should be avoided as this may cause hardening and coloring of the fibers. For drying, it is preferable to use a hot roller dryer in which the fibers come into contact with a hot metal surface. Additionally, it is more preferable to use supplementary drying by blowing hot air at a temperature of 100 to 150° C. in order to improve the uniformity of drying. The moisture content of the dried fibers must be kept to 1.0% or less. If the moisture content exceeds 1.0%, uneven drying of the fibers will occur, resulting in the presence of a large number of microorganisms in some areas, which will reduce the uniformity of quality such as uneven dyeing, uneven gloss, and uneven strength. must be avoided. In this drying process, a torque motor is used for the driving part, and at the same time as drying, the
% shrinkage is also possible.

After drying, the fibers are heated under moist heat to 3 times or less, preferably in order to clearly phase separate the acrylic polymer and cellulose acetate in the fibers, improve water absorption, and provide appropriate fiber properties. It is necessary to perform secondary stretching of 1.05 to 2 times. If the stretching ratio exceeds 3 times, yarn breakage will occur), and to avoid this, if the temperature is raised to a high temperature, the fibers will stick and fuse together9, resulting in a significant drop in water absorption. After the second stretching, the final product is obtained through a post-processing process that imparts good spinnability and performance, such as wet heat shrinkage, oiling, clinging, and crimp setting.

Thus, the porous acrylic synthetic fiber provided by the present invention is composed of the above-mentioned acrylic copolymer 70-98.
% by weight and cellulose acetate from 30 to 2% by weight, the presence of microscopic pores is suppressed and the cellulose acetate contains giant pores.

If the amount of cellulose acetate dispersed in the fiber is less than 2% by weight, the amount of phase separation from the acrylic polymer will be insufficient and the imparting of water absorption will not be sufficient, whereas if it exceeds 30% by weight, the phase separation will occur. It must be avoided because it causes large wrinkles and decreases in fiber strength and elongation, dyeability, gloss, etc.

In the acrylic synthetic fiber of the present invention, cellulose acetate is dispersed in the form of streaks in the fiber axis direction, and the ratio of the length to diameter of the streaks is usually 10 or more.

Further, as described above, the acrylic synthetic fiber of the present invention suppresses the presence of microvoids and contains giant pores. Therefore,
The acrylic synthetic fiber of the present invention mainly contains giant pores, and if we take the ratio (volume ratio) of micro pores to the porosity (V) of the fiber as an example, the ratio is preferably at most 30, for example. represents 25 inches or less, more preferably 20% or less, particularly preferably 15 inches or less. Here, micropores have a diameter of λ0
Refers to pores of 00.4 or less.

Therefore, the water absorbency of the acrylic synthetic fiber of the present invention is substantially achieved by the giant pores. In other words, it is thought that the reason why the acrylic synthetic fiber of the present invention exhibits excellent water absorption performance is that the pores opened on the surface communicate with the giant pores inside. This means that when the acrylic synthetic fiber of the present invention is observed under a microscope, cellulose acetate is not only dispersed inside the cross section of the fiber, but is also dispersed on the fiber wall, and is found around the dispersed particles. This is supported by the fact that the giant pores seen are also seen on the fiber surface.

Furthermore, the acrylic synthetic fiber of the present invention has a pore surface area A
is 15 m”/f or less, preferably 0.02 to 10 m”
/f, porosity V is 0.05 to 0.75 cm"
/IF, preferably 0.05-0.60 cm”
/t, and V/A is 1/aO or more, preferably -21- is 1/20 or more.

The surface area of the pores in the fiber (A <m''/r) can be calculated by adsorbing nitrogen gas onto the fiber at liquid nitrogen temperature, calculating the total surface area of the fiber using the BET equation, and subtracting the surface area of the fiber sheath from that value. I met.

The amount of fiber used for the measurement was adjusted so that the total surface area to be measured was 1 m'' or more.The porosity V (crn''/f) was determined using a sufficiently dense fiber with the same composition as the fiber. The density ρ (f/8) of the film prepared in The true average cross-sectional area of the portion not included is S O (m'') and can be determined by the formula (2).

900000Xρ However, De is denier.

-22- 1　S-5゜ ρ　S.

Further, the ratio of micropores to the porosity was calculated by measuring the micropore content using a mercury porosimeter.

First, the fibers are defibrated, weighed, and filled into a mercury porosimeter cell, and while pressurizing mercury at room temperature, the pressure and amount of mercury injected are recorded. By measuring the diameter D (μ) of the hole, the amount required to fill the hole with mercury, P, and the amount of mercury injected, the diameter D (μ) of the hole and the volume (tYn” / t) can be determined.
) be criticized. This is the vacancy distribution curve, and D is 0.
．． The amount of pores of 2μ or less was defined as the micropore content in fiber lf (33/f).

When the porosity r is less than 0.05 cm"/r, the water absorption of the fiber is sufficient, while when it exceeds 0.75 crn"/r, the strength and elongation of the fiber decrease, and the fiber becomes glossy. ,
It also has a negative effect on dyeability, so it must be avoided.

In addition, if the surface area A of the pores exceeds 15 m''/l, minute pores will increase in the fiber, which will not only reduce strength and elongation, but also reduce dyeability and heat resistance, so it must be avoided. Further, if V/A is less than 1730, water absorption becomes insufficient, or not only strength and elongation but also heat resistance, dyeability, etc. decrease.

Combining the experimental results of the present inventors, the V/A is l/30
When the diameter is less than 1, the pores in the fiber become small, and the size of the pores becomes, for example, a radius of less than 1000 A when converted into a sphere, making it impossible to obtain excellent water absorbency and also decreasing strength and elongation.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples. still,
Parts and parts used in the examples represent parts by weight and % by weight unless otherwise specified. Also, the water absorption rate is DIN-5381
4.

Example 1 Dimethylformamide (hereinafter referred to as D
(abbreviated as MF) solution was combined with the spinning stock solution DMF:Water-6
5:35 (%), spun into a coagulation bath at 20°C. The composition of the acrylic polymer is: acrylonitrile (hereinafter abbreviated as AN): methyl nyacrylate (hereinafter abbreviated as HA): sodium methallylsulfonate (hereinafter abbreviated as SMAS) -90,5: 9.0: O15 ( h). After spinning, the yarn was stretched 5 times and dried in a hot roller dryer at 120°C until the moisture content became 0.5%.
Secondary stretching was performed L1 times under moist heat at 100°C. After crimping and crimp setting, 3d# fibers were obtained. The results are shown in Table 1.

-25- 1 26- Kao, huge pores (diameter 2゜000) in porosity (F)
The ratio of A or higher) was 8 & 7 volume units for the Ekp-164 fibers, and 85°4 volume units for the Ezp-As fibers.

Example 2 Various manufacturing conditions were changed to obtain 3d-fibers shown in Table 2. The acrylic polymer used in Example 1 was used.

27- Table 2 32- -28- Example 3 AN: HA: Sodium allylsulfonate (hereinafter referred to as SA
Spinning was carried out using 80 parts of an acrylic polymer having a composition of -90.2:9.0:0.8 and 20 parts of cellulose acetate, and a spinning stock solution under the conditions shown in the table. ,
A 3 da fiber was obtained under the post-spinning treatment conditions of Example 1.

However, for the spinning bath only, an aqueous solution of the same solvent as that of the spinning dope was used.

The results are shown in Table 3. The viscosity in the table is the viscosity measured at 50℃ using a B-type viscometer, and the stability is 50℃.
It is an FC test that evaluates the stability against oxidation at ℃ and the dispersion stability of the acrylic polymer and cellulose acetate in the dope.

29- Example 4 AN', MA:SMAS-90,5:9.0:0.5(
A spinning stock solution in which 90 parts of an acrylic polymer and 10 parts of cellulose acetate having a composition of It was spun into a coagulation bath and subjected to primary stretching at various magnifications. - After the next stretching, drying and post-treatment were carried out under the conditions of Example 10 to obtain a 3 da fiber. The results are shown in Table 4.

Example 5 AN: MA: SMAS-92,5: 7.0:
A spinning stock solution prepared by dissolving 90 parts of a polymer having a composition of 0.5 (%) and 10 parts of cellulose acetate in DMF to a polymer concentration of 25% was prepared using DMF:water = 6o:40.
(%) in a coagulation bath at 30°C, subjected to 4 times primary stretching, dried in a hot roller dryer with the drying temperature shown in Table 5 to a moisture content of 0.5% or less, and then Secondary stretching was carried out twice under heating at 110° C., and a 3D fiber was obtained after crimping and crimp setting. The results are shown in Table 5.

-33- 1 34- Example 6 AN:MA:5AS=89:10.4:0.6 (%)
A spinning stock solution in which 85 parts of a polymer having the composition and 15 parts of cellulose acetate were dissolved in DMF to give a polymer concentration of 27% was spun into a coagulation bath at 30°C at a DMF:water ratio of 70:30. Stretching is performed 5 times.

- After the second stretching, the fibers were dried in a roller dryer at 125° C. to various residual moisture contents, and then 2de fibers were obtained according to the post-treatment conditions of Example 2.

The results are shown in Table 6.

The proportion of giant pores in the porosity (V) is Ezp-
The fiber of boiled 67 has a volume of 84.7, and the Exp-bread 6
In the case of No. 9 fiber, the volume was 85.8 cm.

Example 7 The spinning stock solution of Example 6 was mixed with DMF:water-65:35 at 25°C.
The fibers are spun in a coagulation bath and subjected to 4x primary stretching.
Dry in a roller dryer at 25°C to a moisture content of 0.7% or less. After drying, secondary stretching was performed under the secondary stretching conditions shown in Example 5 to obtain adz fibers after fringing and crimp setting. The results are shown in Table 7.

-37- Example 8 AR:MA: SMAS=90.5: 9.0:
80 parts of an acrylic polymer and 20 parts of cellulose acetate having a composition of 0.5 (relative) were dissolved in DMF to a polymer concentration of 20 or more, and 2 parts were added to 100 parts of the total amount of polymer and DMF. DMF:water-50
:50 (regret) in a coagulation bath at 25°C, after washing with water,
Stretched 4 times in hot water, dried in a roller dryer at 135°C to a moisture content of 1.0 inches or less, and then subjected to secondary stretching to 2x under moist heat at 115°C to impart crimp and crimp set. After that, 3dII fibers were obtained.

The fibers are slightly dull and the porosity is VO, 3cm" /
11 pore surface area AL03m”/f and V/A-1/3.
No. 43 is a porous acrylic fiber containing ido.

The yarn quality is TE=-/l/2d e, dry strength 2.9f/d
Ti.

-39- The dry elongation was 30.5%. Also, wet strength 2.81f/d
e, wet elongation a1. There was no decrease in thread quality even when wet with 9 g of a.

Effects of the Invention The features of the porous acrylic synthetic fiber obtained by the present invention are that it has a large water absorption rate and water absorption rate, has excellent wet strength and elongation when water is absorbed, has good gloss, and has a high water absorption rate when dyed. Examples include vivid colors. Natural fibers are bulky and stiff when wet, but the porous acrylic synthetic fibers of the present invention have a physical water absorption mechanism that sucks water into the pores in the fibers. , the bulkiness of the fibers, the lower back feeling is greatly reduced, and in addition, the water absorbency,
Excellent water permeability and moisture permeability. Furthermore, the fibers according to the present invention have extremely excellent anti-build properties. Normally, in order to impart anti-pilling properties, modification of the spinning dope and stretching/shrinkage are necessary, such as reducing the amount of peripheral components in the acrylic polymer, reducing the polymer molecular weight, and mixing -40- or low molecular weight polymers. This is due to changes in post-processing conditions such as conditions, and as a result, some of the fiber performance such as a decrease in strength and elongation, a decrease in heat resistance, and a decrease in spinnability, as well as workability, are sacrificed. The synthetic acrylic fibers have excellent anti-pilling properties without any deterioration in fiber performance or workability.

The porous acrylic synthetic fiber invented by Higashi 2F has a porosity of 0.05 cIn"/f to 0.75 crn"/l, and has extremely excellent storage and heat retention properties.

The porous acrylic synthetic fiber of the present invention, which has many excellent properties that have never existed before, can be used not only for general clothing as inner and outer clothing, but also for sportswear, futon cotton,
Ideal for bedding such as curtains, interior decoration, etc. or,
It can also be used in fields where cotton was used as a cotton substitute.

-41- -ζ71

Claims (1)

[Claims] 1. (α) Copolymerized with 0.3 to 1.2% by weight of a copolymerizable monomer containing at least 80% by weight of acrylonitrile units and having a sulfonic acid group or a sulfonic acid group. 70 to 98% by weight of acrylonitrile copolymer and 30 to 2% by weight of cellulose acetate, (6) the surface area A of the pores is 15 m''/f' or less,
The porosity V is 0405~0.75"/f and V
/A is 1/30 or more, and (6) a porous acrylic synthetic fiber characterized by suppressing the presence of microvoids and containing giant pores. 2. The fiber according to claim 1, wherein cellulose acetate is dispersed in a streaky manner in the fiber axis direction. 3. The fiber according to claim 1, which contains 3 to 20% by weight of cellulose acetate. 4. The fiber according to claim 1, wherein the degree of acetylation of cellulose acetate is 48 to 63%. 5. The fiber according to claim 1, wherein the copolymerizable monomer of the acrylonitrile-based copolymer is sodium methallylsulfonate or sodium acrylsulfonate. a The fiber according to claim 1, wherein the surface area A of the pores is 0.02 to 10'm"/r. 7. The fiber has a porosity V of 0.05 to 0.6 cm"/r. The fiber according to claim 1. 8. The fiber according to claim 1, which has a V/A of 1/20 or more.