JPS6149406B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a porous vinyl synthetic fiber and a method for producing the same. Natural fibers such as cotton, wool, and silk have a water absorbency of 20 to 40% and can sufficiently absorb sweat from the human body, making them comfortable to wear, but synthetic fibers have antistatic properties. and lack of hygroscopicity, as well as water absorption,
In terms of commercial value, it is inferior to natural fibers in that it does not have sweat absorption properties. Especially in underwear, socks, blankets and other bedding, and sportswear, etc., if they do not have water- or sweat-absorbing properties, sweat emitted from outside the body will condense and adhere to the fiber surface.
There are unavoidable discomforts when wearing them, such as stickiness, a cold sensation, and a decline in the ability to regulate body temperature. 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 micropores in the fibers or forming irregularities on the fiber surface. For example, JP-A-47-25418, JP-A-47-15901, JP-A-48-6649,
Japanese Patent Publication No. 48-6650 describes a method for producing porous acrylic fibers by selecting mild drying conditions that leave minute voids in the swollen gel tow during the production process of acrylic fibers. ing. Also, JP-A-47-25416, JP-A-48-
Publication No. 8285 and Japanese Patent Publication No. 48-8286 disclose that during the production process of acrylic fibers, swollen gel tow is filled with a water-soluble compound, and after drying and post-treatment, the filler is eluted and voids are regenerated. Are listed. What the above methods have in common is that the microvoids originally contained in the swollen gel tow during the production process of acrylic fibers are left in the final product to produce porous acrylic fibers. The microvoids contained in this swollen gel tow are extremely unstable thermally. For this reason, it is not possible to perform high-temperature treatment in the fiber manufacturing process, especially in the drying, shrinking, and crimp-setting steps, 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 have a void radius of 10~
It is extremely small at 1000 Å. Because the fibers contain countless microvoids uniformly throughout the fibers, the fibers have many drawbacks such as low strength and elongation, poor gloss, and dull color after dyeing. or,
Due to the uniform presence of countless minute voids, the fiber has poor heat resistance, and when subjected to high temperatures, dyeing, steaming, ironing, etc., the voids disappear, resulting in decreased water absorption, changes in color, and poor shape retention. Significant quality deterioration, such as deterioration, is observed. Furthermore, attempting to develop water absorbency using such microvoids is 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 to have a certain degree of water absorption, a considerable amount of microvoid content is required, which has the disadvantage of further reducing fiber performance and commercial value. Attempts have been made heretofore to improve the texture and dyeability by spinning a mixture of cellulose acetate-acrylic polymers or cellulose acetate-modacrylic copolymers. For example, Japanese Patent Publication No. 31-968, Publication No. 2317-1973, Publication No. 14029-1973.
The publication describes a method for producing fibers with improved dyeability and texture from a spinning dope in which cellulose acetate is mixed with an acrylic polymer or modacrylic copolymer. The fibers obtained by this method are sufficiently dense and have water-absorbing properties that have capillary-like macrovoids inside the fibers. Furthermore, Japanese Patent Publication No. 39-14030 describes adding cellulose acetate during the polymerization of an acrylic polymer as a means of mixing. If used, the heat resistance of the spun yarn will decrease due to the modification of cellulose acetate, causing trouble during the fiber manufacturing process, and the quality of the product will not be sufficient. on the other hand. Tokuko Showa 44-
11969, JP-A-50-118027, and JP-A-50-118026 disclose that cellulose acetate is finely dispersed in an acrylic polymer or a modacrylic polymer, or cellulose acetate and titanium oxide, etc. Although methods have been described in which fibers similar to animal hair are obtained by finely dispersing the fibers, porous fibers having water absorbing properties as obtained in the present invention have not been obtained. For the reasons mentioned above, it is not possible to produce porous acrylic synthetic fibers that have good water absorption, heat resistance, dyeability, and gloss using conventional methods. The present inventors completed the present invention as a result of intensive research to improve these points. An object of the present invention is to provide a porous vinyl-based polymeric synthetic fiber that has excellent water absorption, gloss, and dyeability, and has good thread quality. Another object of the present invention is to provide a method for industrially easily and inexpensively producing porous vinyl synthetic fibers having excellent water absorbency and good thread quality. The present invention uses 50 to 98 parts by weight of vinyl polymer []
and 2 to 50 parts by weight of cellulose acetate [],
0.5 to 50 per 100 parts by weight of the total amount of [] and []
5 to 30 parts by weight of the monomer represented by the general formula below
% by weight, and has a porosity V of 0.05 to 0.75 cm ³ /g, a pore surface area A of 15 cm ³ /g or less, and a V/A of 1/30 or more. It is a porous vinyl synthetic fiber containing pores.
The method of the present invention uses 50 to 98 parts by weight of vinyl polymer [I] and 2 to 50 parts by weight of cellulose acetate []
and 0.5 per 100 parts by weight of the total amount of [] and []
~50 parts by weight of the monomer represented by the following general formula
An organic solvent solution containing ~30% by weight of an acrylic polymer [] containing 15% to 35% by weight is spun into a coagulation bath, first stretched 2.5 to 8 times, and swelled with water. The fibers in this state are dried at a temperature of 100 to 180°C until the moisture content becomes 1 part by weight or less, and then subjected to secondary stretching of 3 times or less using moist heat. general formula However, (X: R ₂ or R ₁ R ₃ : H or CH ₃ R ₂ : H or NH ₄ or alkali metal l, m: an integer of 0 to 50 and satisfying 0<l+m≦50) The vinyl synthetic fiber of the present invention ~98 parts by weight,
Preferably 70 to 98 parts by weight of vinyl polymer []
and 2 to 50 parts by weight, preferably 2 to 30 parts by weight of cellulose acetate [], and the total amount of [] and []
0.5 to 50 parts by weight per 100 parts by weight, preferably 2 to 50 parts by weight
5 to 30 parts by weight of the monomer represented by the above general formula
It consists of an acrylic copolymer containing 30% by weight. Vinyl polymers applicable to the present invention include:
Acrylic polymers containing at least 80% by weight of acrylonitrile, or modacrylic copolymers containing 20 to 60% by weight of vinyl chloride and/or vinylidene chloride and at most 80% by weight of acrylonitrile. Other copolymerizable monomers other than those shown in the general formula, in an amount of 20% by weight or less for the acrylic polymer, and 5% by weight or less for the modacrylic copolymer,
For example, methyl acrylate, methyl methacrylate,
Alkyl esters of acrylic acid or methacrylic acid such as ethyl acrylate, amides such as acrylamide and methacrylamide, and their N
-mono-substituted or N.N-disubstituted amides, vinyl acetate, sulfonic acid group-containing monomers such as styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and salts thereof. In particular, by copolymerizing 0.3 to 3% by weight of allylsulfonic acid or methallylsulfonic acid and their salts, it not only improves the dyeability but also suppresses the generation of countless minute voids and improves heat resistance. It is possible to obtain porous fibers that suppress deterioration, have macroscopic pores, and have excellent water absorbency. Further, the cellulose acetate applied to the present invention is not particularly limited, but usually has a degree of acetation of 48 to 63% and an average degree of polymerization of 50 to 300. Vinyl polymer [] and cellulose acetate []
In terms of the quantitative relationship, if the amount of cellulose acetate [ ] is less than 2 parts by weight, phase separation from the vinyl polymer [ ] will be insufficient and water absorption will not be imparted sufficiently.
On the other hand, if it exceeds 50 parts by weight, the phase separation becomes large and non-uniform, resulting in a decrease in fiber strength, elongation, and workability, and must be avoided.
Also, the amount of acrylic copolymer [] is the total amount of vinyl polymer [] and cellulose acetate []
If it is less than 0.5 part by weight per 100 parts by weight, it should be avoided because it has little effect on the dispersibility of cellulose acetate and also has little effect on improving the dyeability and gloss of the vinyl synthetic fiber. In addition, if the content exceeds 50 parts by weight, it must be avoided because it causes a decrease in water absorption and a decrease in the heat resistance of the fiber. If the content of the general formula monomer in the acrylic copolymer [] is less than 5% by weight, the gloss, dyeability, and
The improvement in the dispersibility of cellulose acetate and cellulose acetate is not sufficient, and on the other hand, if it exceeds 30% by weight, the heat resistance and water absorption of the fiber will decrease and must be avoided. In the vinyl synthetic fiber of the present invention, cellulose acetate [] undergoes phase separation with the vinyl polymer [] and the acrylic copolymer [], and is dispersed in a streak-like manner in the fiber axis direction. The length to diameter ratio is 10
That's all. The vinyl synthetic fiber of the present invention mainly has giant pores in the fiber, and the giant pores are produced by phase separation between cellulose acetate and vinyl polymer. These giant pores greatly contribute to water absorption, and the vinyl polymer component of the fiber of the present invention has approximately the same density as ordinary acrylic fibers and modacrylic fibers.
Further, the vinyl synthetic fiber of the present invention has a pore surface area A of 15 m ² /g or less, preferably 0.02 to 10 m ² /g,
The porosity V is 0.05 to 0.75 cm ³ /g. Preferably 0.05~
At 0.60 cm ³ /g, V/A is 1/30 or more, preferably 1/20 or more. The surface area A (m ² /g) of the pores in the fiber is determined by adsorbing nitrogen gas onto the fiber at liquid nitrogen temperature.
The total surface area of the fiber was determined using the BET equation, and the surface area of the fiber sheath was subtracted from that value. The amount of fiber used for measurement was adjusted so that the total surface area to be measured was 1 m ² or more. In addition, the porosity V (cm ³ /g) is the density ρ (g/g) of a sufficiently dense film with the same composition as the fiber.
cm ³ ), and the average area including pores of the fiber determined by photographic method is S(cm ³ ), and the true average cross-sectional area of the part of the fiber not including pores determined from the formula is It can be obtained from the formula with So (cm ³ ). So=De/900000×ρ However, De is the denier of the fiber. V=1/ρ=S-So/So If the porosity V is less than 0.05 cm ³ /g, the water absorbency of the fiber is insufficient, while if it exceeds 0.75 cc/g, the strength and elongation of the fiber will simply decrease. However, it must be avoided as it also has a negative effect on gloss and dyeability.
In addition, if the surface area A of the pores exceeds 15 m ² /g, the number of pores increases minutely within the fiber, which not only reduces strength and elongation, but also reduces dyeability and heat resistance, so this should be avoided. . Furthermore, if V/A is less than 1/30, water absorption becomes insufficient, or not only strength and elongation but also heat resistance, dyeability, etc. are reduced. Combining the inventors' experimental results, V/A is 1/
When it is less than 30, the pores in the fiber become small, and the size of the pores becomes, for example, a radius of less than 1000 Å when converted into a sphere, so that excellent water absorption cannot be obtained and strength and elongation are also reduced. The vinyl synthetic fiber of the present invention contains 50 to 98 parts by weight,
Preferably 70 to 98 parts by weight of vinyl polymer [I]
and 2 to 50 parts by weight, preferably 2 to 30 parts by weight of cellulose acetate [], and the total amount of [] and []
0.5 to 50 parts by weight, preferably 2 parts by weight per 100 parts by weight
~30 parts by weight of the monomer represented by the above general formula,
Acrylic copolymer containing 5 to 30% by weight []
The polymer is produced by spinning a solution in an organic solvent containing 15 to 35% by weight into a coagulation solution preferably at a high temperature of 30°C. If the amounts of vinyl polymer [], cellulose acetate [] and acrylic copolymer [] exceed this range, vinyl synthetic fibers with excellent water absorption, gloss, dyeability, and thread quality cannot be obtained. . In particular, the amount of acrylic copolymer []
If the total amount of polymer [] and [] is less than 0.5 parts by weight, the dispersibility and stability of cellulose acetate [] in the spinning stock solution will be insufficient, while if it exceeds 50 parts by weight, the spinning will be difficult. Phase separation of the acrylic copolymer occurs in the stock solution, which must be avoided because it increases non-uniformity and reduces the heat resistance of the fiber. Furthermore, if the content of the monomer of the above general formula in the acrylic copolymer [] is less than 5% by weight, the dispersibility and stability of cellulose acetate in the spinning dope will be insufficient; If it exceeds, the hydrophilicity of the polymer becomes excessive and phase separation occurs in the spinning dope.
Moreover, it must be avoided because it lowers the heat resistance of the fiber. The monomers represented by the above general formula that are copolymerized into the acrylic copolymer include acrylic acid, methacrylic acid, and is preferable from the viewpoint of polymerizability, discoloration property, and water solubility. The longer the ethylene glycol chain or propylene glycol chain contained in these monomers, the more hydrophilic the acrylic copolymer [] will be. If it is exceeded, the polymerizability and solubility of the acrylic copolymer will decrease and must be avoided. As monomers other than the monomers represented by the above general formula that can be copolymerized with the acrylic copolymer, the aforementioned monomers applicable to the vinyl polymer can be used. If the concentration of the polymer in the organic solvent solution is less than 15% by weight, not only will the production cost be relatively high, but also voids will occur and strength and elongation will decrease. 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. As the organic solvent to be applied to the present invention, individual solvents for polymers [] [] and [] can be used, but in particular, common solvents such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and ethylene carbonate can be used as solvents. It is also preferable from the viewpoint of recovery and purification. In addition, as the coagulation bath, an aqueous solution of an organic solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide and ethylene carbonate, and an organic solvent such as propylene alcohol or kerosene can be used. It is preferable to use Additives such as water and ammothine oxide may be added to the spinning dope in a range that does not cause the spinning dope to gel. Spinning can be carried out under the same conditions as ordinary acrylic synthetic fibers or modacrylic synthetic fibers, and the fibers are sequentially stretched through several baths and washed with water.
Primary stretching is performed 2.5 to 8 times, preferably 3 to 6 times. If the primary stretching is less than 2.5 times, the fiber stretching
Due to lack of orientation, the strength is low, and cracks form in the fibers, which must be avoided. On the other hand, if it exceeds 8 times, densification progresses too much and sufficient water absorbency cannot be obtained, and operability may deteriorate, so it must be avoided. In the yarn that has been subjected to the primary drawing, the pores generated due to the linear dispersion of cellulose acetate and the phase separation from the vinyl polymer are usually more clearly defined. This fiber also contains a large number of microvoids that are originally contained in ordinary swollen gel tow. These microvoids generally have a small contribution to the water absorbency of the fibers, and are undesirable because they reduce the heat resistance, dyeability, gloss, etc. of the fibers. For this purpose, fibers with a mixture of microvoids and large voids are dried to eliminate the microvoids, but the drying conditions in this case are as follows:
By drying at a temperature of 100 to 180°C until the moisture content is 1.0% by weight or less, only microvoids can be eliminated while large voids due to phase separation can be left behind. If the drying temperature is less than 100°C, the microvoids present in large numbers on the vinyl polymer side will not be completely burned out, resulting in a decrease in the strength and elongation of the yarn, as well as a decrease in gloss, dyeability and heat resistance. Furthermore, temperatures exceeding 180°C should be avoided as this will 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. Further, it is more preferable to use supplementary drying by blowing hot air at a temperature of 100 to 150° C. from the viewpoint of improving the uniformity of drying. The moisture content of dried fibers must be kept below 1.0%. If the moisture content exceeds 1.0%, the fibers will dry unevenly, resulting in the presence of many microvoids in some areas, which should be avoided as it will reduce the uniformity of quality such as uneven dyeing, uneven gloss, and uneven strength. . It is also possible to use a torque motor as the drive unit in this drying process to achieve a shrinkage of 5 to 15% at the same time as drying. After drying, the fibers are dried to make the phase separation between the vinyl polymer and cellulose acetate in the fibers clearer, improve water absorption, and provide appropriate fiber properties.
It is necessary to carry out secondary stretching by 3 times or less, preferably 1.05 to 2 times, under moist heat. If the stretching ratio exceeds 3 times, yarn breakage will occur, and to avoid this, if the temperature is raised, the fibers will stick and fuse, resulting in a significant drop in water absorption. After the second stretching, it is usually subjected to post-treatment steps such as wet heat shrinkage, oiling, crimping, crimp setting, etc. to give better spinnability and performance.
It becomes the final product. The features of the porous vinyl synthetic fiber obtained by the present invention are that it has a high water absorption rate and water absorption rate;
Examples include excellent wet strength and elongation upon water absorption, good gloss, and vivid color when dyed. In natural fibers, bulkiness when wet,
However, the porous vinyl synthetic fiber according to the present invention has a physical water absorption mechanism that sucks water into the pores in the fiber, so there is no decrease in the bulkiness or stiffness of the fiber. On top of that, it is water absorbent,
Excellent water permeability and moisture permeability. Furthermore, if a modacrylic copolymer containing 20 to 60% by weight of vinyl chloride and/or vinylidene chloride is used as the vinyl polymer [], fibers with excellent water absorption and flame retardancy can be obtained. Furthermore, the fibers according to the present invention have excellent anti-pilling properties. Normally, in order to impart anti-pilling properties, modification of the spinning stock solution and stretching/shrinking conditions, etc., are necessary, such as reducing the amount of plastic components in the acrylic polymer, reducing the polymer molecular weight, or mixing low molecular weight polymers. This is due to changes in processing conditions, and this affects 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 operability. Vinyl synthetic fibers have excellent anti-pilling properties without deterioration in fiber performance and workability. Furthermore, the porous vinyl synthetic fiber according to the present invention has a porosity of 0.05.
cm ³ /g to 0.75cc/g, making it extremely lightweight and heat retaining. The porous vinyl 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 general clothing.
Sportswear, futon cotton, bedding such as curtains,
Ideal for interior decoration, etc. In addition, it can be fully used in fields where cotton was used as a cotton substitute. Hereinafter, the present invention will be explained in detail by showing examples. Note that parts and percentages used in the examples represent parts by weight and percentages by weight unless otherwise specified. Moreover, the water absorption rate was measured according to DIN-53814. Example 1 Vinyl polymer [] (100-C) part, cellulose acetate []C part, and acrylonitrile (hereinafter referred to as
(abbreviated as AN): CH ₂ = CH−COO
(CH ₂ CH ₂ O) ₁₀ H = 90:10 acrylic copolymer [] with a composition of 10% by weight, a polymer containing 2 parts per 100 parts of the total amount of [] and [] was added at a concentration of 25%. %
Dimethylformamide (hereinafter referred to as DMF)
The spinning stock solution dissolved in DMF:water
56:44 (%), spun into a coagulation bath at 20°C, first stretched 5 times, dried in a hot roller dryer at 120°C until the moisture content was 0.7%, and heated at 100°C under moist heat.
Secondary stretching was performed at 1.1 times. Thereafter, 3de fibers were obtained after crimping and crimp setting. The results are shown in Table 1. Also, as a vinyl polymer [], Exp-No.1
In ~9, AN: Methyl acrylate (hereinafter abbreviated as MA): Sodium metaallylsulfonate (hereinafter abbreviated as MA):
(abbreviated as SMAS) = 90.5:9.0:0.5 (%) acrylic copolymer, and in Exp-No. 10 to 17,
AN: Vinylidene chloride (hereinafter abbreviated as VDC):
A modacrylic copolymer with SMAS=58:40:2 (%) was used.

[Table] Example 2 Polymers of 85 parts of vinyl polymer [], 15 parts of cellulose acetate [], and various ratios of acrylic copolymer [] were added to DMF so that the polymer concentration was 23%. The dissolved spinning stock solution was subjected to the spinning and post-treatment conditions of Example 1 to obtain 3de fibers. As a vinyl polymer [], in Exp18-25, AN:MA:
SMAS = 90.5: 9.0: 0.5 (%) acrylic copolymer, Exp-No. 26 to 33, AN: VDC:
A modacrylic copolymer with SMAS=58.5:40:1.5 (%) was used. Also, acrylic copolymer []
As, AN: CH ₂ = CH−COO
(CH ₂ CH ₂ O) ₉ CH ₃ =85:15 (%) was used. The results are shown in Table 2.

[Table] Example 3 Acrylic copolymer with a composition of 85 parts of vinyl polymer [], 15 parts of cellulose acetate [], 10% of monomers represented by the following general formula, and 9.0% of AN. Coalescing [] A polymer consisting of two parts, the polymer concentration
The spinning stock solution dissolved in DMF to a concentration of 27%,
A 3de fiber was obtained under the spinning and post-processing conditions of Example 1. General formula CH ₂ = CH−COOX (However, X: R ₂ or ) In addition, as a vinyl polymer [], Exp-
For No. 34 to 40, AN: MA: Sodium acrylic sulfonate (hereinafter abbreviated as SAS) = 90.3: 9.0: 0.7
(%) of acrylic copolymer, and Exp-No.41~
In No. 47, a modacrylic copolymer with AN:VDC:SAS=54:44:2 (%) was used. The results are shown in Table 3.

[Table] Example 4 85 parts of vinyl polymer [], 15 parts of cellulose acetate [], and 5 parts of AN: CH ₂ =CH-
COO(-CH ₂ CH ₂ O) ₁₀ An acrylic copolymer [] with the composition of H=(100-C):C (%) was dissolved in DMF so that the polymer concentration was 25%. The raw stock solution is spun into a DMF:water 60:40 (%) coagulation bath at 25°C, and after primary stretching is performed 4 times, the moisture content is reduced to 0.5% in a heated roller dryer at 127°C. until dry. After drying, perform secondary stretching of 1.4 times at 105℃ under moist heat, apply crimps, and 5de after crimp setting.
fibers were obtained. The results are shown in Table 4. In addition, as vinyl polymer [], AN:MA:SMAS=
An acrylic copolymer of 92.4:7.0:0.6 (%) was used. C in the table is the content of _CH2 =CH-COO( _-CH2CH2O ) _10H in _the acrylic copolymer [].

[Table] Example 5 By changing various manufacturing conditions, 2de fibers shown in Table 5 were obtained. As the vinyl polymer [] and the acrylic copolymer [], those shown in Example 1 were used.

[Table] Example 6 90 copies of AN: VDC: SMAS = 54.5: 44.0: 1.5
Modacrylic polymer with a composition of (%) [ ]
, 10 parts of cellulose acetate, and 5 parts of cellulose acetate.
An acrylic copolymer having a composition of AN:CH ₂ =CH-COOH = 90:10 (%) was dissolved to the polymer concentration shown in Table 6 to prepare a spinning stock solution. The spinning and post-treatment conditions were as in Example 4 to obtain 3de fibers. However, the coagulation bath used was an aqueous solution of the solvent used for the spinning dope. In addition, the viscosity in the table is the viscosity measured at 50℃ using a B-type viscometer, and the stability indicates the gelation resistance stability and dispersion stability of cellulose acetate at 50℃. It is.

[Table] Example 7 80 copies of AN: VDC: SMAS = 54.5: 44.0: 1.5
(%) of modacrylic copolymer [], 20 parts of cellulose acetate [], and 5 parts of cellulose acetate [].
AN: A polymer consisting of an acrylic copolymer [ ] having the composition is mixed in DMF to a polymer concentration of 25%.
The spinning stock solution dissolved in DMF: water = 65:35 (%),
It was spun into a coagulation bath at 20°C. Primary stretching was performed at various magnifications shown in Table 7, and the moisture content was 0.7% at 130°C.
After drying until the film was dry, it was subjected to a second stretching of 1.6 times at 115° C. under moist heat. After the second stretching, crimping and crimp setting were performed to obtain a 3de fiber. The results are shown in Table 7.

[Table] Example 8 AN of 85 copies: MA: SAS = 90.3: 9.0: 0.7 (%)
Acrylic copolymer with the composition [], 15 parts of cellulose acetate [] and 3 parts of AN: A spinning stock solution prepared by dissolving the polymer that will become the acrylic copolymer [] with the composition in DMF so that the polymer concentration is 21% is DMF: water = 50:50 (%), 15
It was spun into a coagulation bath at °C. 4 parts of primary stretching were carried out and dried in a heated roller dryer at the temperature shown in Table 8 until the moisture content reached 0.5%, after which 1.3 parts of secondary stretching was carried out under moist heat at 110°C. . After secondary stretching, crimping was applied, and a 3de fiber was obtained after crimp setting. The results are shown in Table 8.

[Table] Example 9 The yarn after the primary stretching of Example 8 was dried in a heated roller dryer at 120°C to various moisture contents, and then subjected to secondary stretching of 1.3 times at 110°C under moist heat. I did this.
After that, apply the crimp and set the crimp.
Got 3de fiber. The results are shown in Table 9.

[Table] Example 10 80 copies of AN: VDC: SAS = 53.5: 44.0: 2.5
Modacrylic copolymer with a composition of (%) []
and 20 parts of cellulose acetate [] and 5 parts of AN: A spinning stock solution prepared by dissolving an acrylic copolymer [] with the composition in DMF to a polymer concentration of 25% was prepared using DMF:water 65:35 (%) at 15℃.
The material was spun into a coagulation bath, and the first stretching was performed 4 times.
After that, the moisture content is reduced in a roller dryer at 130℃.
It was dried to a concentration of 0.7% and subjected to secondary stretching under the conditions shown in Table 10 to obtain a 3de fiber after crimping and crimp setting. The results are shown in Table 10.

【table】

[Table] Example 11 80 copies of AN:VDC:SAS=53.5:44.0:2.5
Modacrine copolymer with a composition of (%) []
and 20 parts of cellulose acetate [] and 3 parts of AN:
CH ₂ = CH−COO (−CH ₂ CH ₂ O) − ₁₀ CH ₃ = 90:10
Acrylic copolymer () with a composition of (%)
and 27% of a mixture of 2 parts antimony oxide.
DMF solution as spinning stock solution DMF: water 60:40
(%), was spun into a coagulation bath at 20°C and first stretched 5 times. After that, it was dried in a heated roller dryer at 120°C until the moisture content was 0.5%, and then dried at 105°C under moist heat.
Secondary stretching was performed at 1.6 times at ℃ to impart crimp.
After crimp setting, a fiber of 1.5 de was obtained. This fiber has a dry strength of 2.9 g/de, a dryness of 31.4%, a porosity of 0.29 cm ³ /g, a surface area of 1.53 m ² /g, and pores of V/A = 1/5.3, and absorbs water. The rate was 33%. It also has excellent flame retardancy, with an oxygen index of 29.

Claims (1)

[Scope of Claims] 1. 50 to 98 parts by weight of a vinyl polymer, and 2.
~50 parts by weight of cellulose acetate [] and 0.5 to 50 parts by weight of a monomer represented by the following general formula based on 100 parts by weight of the total amount of [] and [] to 5 to 30 parts by weight.
It consists of an acrylic copolymer [] containing
A porous vinyl synthetic fiber having a porosity V of 0.05 to 0.75 cm ³ /g, a pore surface area A of 15 m ² /g or less, and a V/A of 1/30 or more. general formula However, [X: R ₂ or R ₁ , R ₃ : H or CH ₃ R ₂ : H or NH ₄ or alkali metal l, m: an integer from 0 to 50 and satisfying 0<l+m≦50] 2 Cellulose acetate is streaked in the fiber axis direction The fibers according to claim 1, which are dispersed in a shape. 3 Vinyl polymer [] is 70 to 98 parts by weight,
The fiber according to claim 1, wherein cellulose acetate [ ] is contained in an amount of 2 to 30 parts by weight. 4 Vinyl polymer [] is acrylonitrile
The fiber according to claim 1, comprising 80% by weight or more of a copolymerizable vinyl monomer other than the monomer represented by the general formula. 5. The fiber according to claim 1, wherein the vinyl polymer [] comprises 20 to 60% by weight of vinyl chloride and/or vinylidene chloride, acrylonitrile, and a vinyl monomer other than the above general formula. 6. The fiber according to claim 1, 4, or 5, wherein the vinyl polymer [] contains 0.3 to 3.0% by weight of a vinyl monomer having a sulfonic acid group. 7 The degree of acetylation of cellulose acetate [] is 48-63%
The fiber according to claim 1, which is 8. The fiber according to claim 1, wherein the acrylic copolymer [ ] is present in an amount of 2 to 30 parts by weight based on 100 parts by weight of the total amount of [ ] and [ ]. 9 50 to 98 parts by weight of vinyl polymer [], and 2
An acrylic copolymer containing ~50 parts by weight of cellulose acetate [] and 0.5 to 50 parts by weight of a monomer represented by the following general formula in an amount of 5 to 30% by weight based on 100 parts by weight of the total amount of [] and [] An organic solvent solution containing 15 to 35% by weight of a polymer consisting of The porosity V is characterized by drying until the moisture content is 1% by weight or less, and then performing a secondary stretching of 3 times or less using moist heat.
A method for producing a porous vinyl synthetic fiber containing pores of 0.05 to 0.75 cm ³ /g, a pore surface area A of 15 m ² /g or less, and a V/A of 1/30 or more. general formula However, [X: R ₂ or R ₁ , R ₃ :H or CH ₃ R ₂ :H or NH ₄ or alkali metal l, m: an integer from 0 to 50 and satisfying 0<l+m≦50] 10 The vinyl polymer [] is The method according to claim 9, comprising 8% by weight or more of acrylonitrile and a copolymerizable monomer other than the monomer represented by the general formula. 11. The method according to claim 9, wherein the vinyl polymer [] comprises 20 to 60% by weight of vinyl chloride and/or vinylidene chloride, acrylonitrile, and a vinyl monomer other than the above general formula. 12 Claims 9, 10, or 11, wherein the vinyl polymer [] contains 0.3 to 3.0% by weight of a vinyl monomer having a sulfonic acid group.
The method described in section. 13. The method according to claim 9, wherein the acrylic copolymer [] is present in an amount of 2 to 30 parts by weight based on 100 parts by weight of the total amount of [] and []. 14. The method according to claim 9, wherein the primary stretching is 3 to 6 times. 15. The method according to claim 9, wherein the drying is carried out at 105 to 140°C. 16. The method according to claim 9 or 15, wherein the drying is carried out using a hot roller dryer. 17. The method according to claim 9, wherein drying is carried out using a hot roller dryer at a temperature of 105 to 140°C, in combination with hot air at a temperature of 100 to 150°C. 18. The method according to claim 9, wherein the secondary stretching is 1.05 to 2 times.