JPS61231221A - Hollow yarn and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled yarn having improved water absorption properties and water vapor absorption, by blending a polyester with specific amounts of a specific metal sulfocarboxylate, a polyoxyalkylene glycol and a metal organic sulfonate to give polyester yarn, treating it with an alkali. CONSTITUTION:A polyester is blended with 0.1-10wt% metal sulfocarboxylate shown by the formula (M<1> and M<2> are metal; n is 1 or 2; R<2> is H, alkyl, ester- forming functional group), 0.1-2wt% polyoxyalkylene glycol insoluble in the polyester and 0.1-1wt% metal organic sulfonate shown by the formula RSO3M (R is 3-30C alkyl, 7-40C aryl or alkylaryl; M is alkali metal) and subjected to melt spinning. The prepared polyester yarn is treated with an aqueous solution of an alkali compound to elute >=2wt% material. The open-fine pores P are formed and the polyoxyalkylene glycol exists biased in the surroundings of the hollow part.

Description

[Detailed description of the invention] a. Field of use TECHNICAL FIELD The present invention relates to hollow fibers and methods for producing the same.

More specifically, the present invention relates to a polyester hollow fiber having special micropores and excellent water absorption and hygroscopicity, and a method for producing the same.

b. Although conventional polyester fibers have many excellent properties,
Since polyester itself is hydrophobic, it has a serious drawback of being inferior in water absorption and hygroscopicity compared to natural fibers such as cotton and linen.

Although various methods have been used to improve the above-mentioned drawbacks of polyester fibers, such as methods of copolymerizing hydrophilic compounds and methods of blending hydrophilic compounds, they are still not satisfactory.

On the other hand, as a post-processing technique to form a hydrophilic resin film on the single fiber surface of polyester fibers, for example, an aqueous dispersion of a polyether ester block copolymer such as polyethylene terephthalate copolymerized with polyethylene glycol is attached and heat-set. Methods such as radical polymerization, ultraviolet polymerization, or electron beam polymerization of polyethylene glycol dimethacrylate have been proposed. However, these methods form a hydrophilic film only on the surface of hydrophobic fibers, and as the affinity between the two is poor, there is a limit to washing durability (, water retention JP wetness perception limit). (
There is no effect of increasing the water retention rate (which gives the feeling of being wet).

On the other hand, the present inventor has already disclosed % 1987-101917, 1982-20612, and 1987-112.
As proposed in Publication No. 12, etc., we have proposed a water-absorbing polyester hollow fiber that utilizes capillarity due to micropores, at least a portion of which communicates from the fiber surface to the hollow portion. Although these proposals have significantly improved the ability to absorb water in a liquid state (water absorbency), such as water absorption rate, water holding rate, wetness perceptual limit, and washing durability, the ability to absorb water in a gas phase, so-called It cannot be denied that the hygroscopicity is insufficient.

C. Purpose of the Invention The present inventor has developed a method that maintains the excellent physical properties inherent to polyester fibers, such as wash-and-wear properties, form stability, high modulus, and heat-set properties, while also achieving excellent water absorption properties. In an effort to provide polyester fibers that also have hygroscopic properties, we conducted intensive studies based on the polyester hollow fibers having the above-mentioned communicating micropores.

As a result, it was surprisingly found that among the compounds disclosed in the above-mentioned publication as a micropore-forming agent, especially in the case of microporous polyester hollow fibers obtained using a sulfocarboxylic acid metal salt represented by the following general formula (1), Before melt spinning this fiber, polyoxyalkylene glycol and the following general formula R8O,M...
... By blending a specific amount of organic sulfonic acid metal salt represented by (mark) [1. By subjecting the hollow fiber to an alkali weight loss treatment after melt spinning, the above purpose can be achieved, and it not only improves the water absorbency It has been found that it is possible to obtain polyester fibers that also exhibit hygroscopic properties. As a result of a detailed study of the structure of the obtained hollow fibers, it was found that the hollow fibers were scattered in the cross section and had a diameter of 0.01 to 3 μm.
m, at least a part of which has fine pores that communicate from the surface of the nuclear fibril to the hollow part, and furthermore, the blended polyoxyalkylene glyfur forms a core-like part dispersed at a high concentration around the hollow part. I learned that.

The reason why such a unique fiber structure is formed is not clear, but it is probably only in the case of hollow fibers melt-spun using polymers with the above compositions that the combinations (such as sulfocarboxylic acid metal salts and organic sulfonate metal salts) It is thought that the salt acts synergistically to promote a type of grease clouding in which most of the polyoxyalkylene glycol aggregates around the hollow part.Then, this bleed-out polyoxyfulkylene glycol causes the above-mentioned interconnected fine particles to form. It is thought that the vapor phase moisture that quickly reaches the hollow part through the pores is efficiently captured and exhibits high hygroscopicity at ℃.

The present invention was completed as a result of repeated studies based on this knowledge.

The structure of the d0 invention, that is, the first aspect of the present invention is a hollow fiber made of polyester, and the hollow fiber is scattered in its cross section and has a diameter of 0.
0.1 to 2% by weight of polyoxyfulkylene glycol, which has micropores of 01 to 3 μm, at least some of which communicate from the fiber surface to the hollow part, and is substantially insoluble in the polyester constituting the hollow fiber, and the following general formula: The second aspect of the present invention relates to a hollow fiber containing 0.1 to 1% by weight of an organic sulfonated metal salt represented by the formula and in which the polyoxyfulkylene glycol is dispersed around the hollow part at a high concentration. is a polyester, 0.1 to 10% by weight of a sulfocarboxylic acid metal salt represented by the following general formula (RI), 0.1 to 2% by weight of a polyoxyalkylene glycol insoluble in the polyester, and the following general formula (1)% formula. % (1) of an organic sulfonic acid metal salt expressed as 0.1 to 1% by weight, melt-spun to obtain hollow fibers, and treated the obtained hollow fibers with an aqueous solution of an alkali compound to reduce the amount of at least 2% by weight. This is a method for producing hollow fibers characterized by elution of %.

The polyester hollow fiber of the present invention will be explained with the attached photograph. Figure 1 shows the polyester hollow fiber of the present invention with a diameter of 2.400.
This is an electron micrograph enlarged twice. As is clear from FIG. 1, the polyester hollow fiber of the present invention has a diameter of 0.
Micropores of 0.01 to 3 μm are uniformly scattered at a temperature of 0.01 to 3.0 °C, and some of these micropores serve as communicating holes from the fiber surface to the hollow portion. According to the results of numerous studies conducted by the present inventors, in order for the polyester fiber of the present invention to exhibit excellent water absorbency and hygroscopicity, it is necessary to be a hollow fiber having a continuous hollow portion in the fiber length direction. Hollow fiber is the cross-section WiK
It has scattered micropores, and these micropores have a diameter of 0.01~
It is necessary that at least a part of the diameter of 3 μm communicates from the fiber surface to the hollow part. Here, the outer shape of the hollow fibers and the shape of the hollow portions may be arbitrary, and may be circular or irregularly shaped (the number of hollow portions may be one or more. Also, the hollow ratio, that is, the apparent The ratio of the cross section of the hollow portion to the cross section of the fiber is preferably in the range of 3 to 30%.

The size, state of existence, and state of communication of micropores can be observed by enlarging the surface or cross section of the fiber approximately 3,000 times. The diameter of this micropore is 0.01 μm
If the diameter is less than 3μ, it will be difficult to obtain sufficient water absorption effect.
If it exceeds m, it is difficult to obtain sufficient fiber strength. In addition, if the length of the micropores is too long, the strength and fibril resistance of the fiber will decrease, so the length of the micropores should be 50% of the diameter.
It is preferably at most twice that amount, particularly preferably at most 20 times. The simplest and easiest way to confirm the state of communication between the fiber surface and the hollow part of the micropores is to observe a single fiber several centimeters in length with a normal optical microscope, and add water ( A test can be carried out in which one drop of dyed water (more preferably dyed water) is added, and the state of communication of the micropores can be easily confirmed by whether or not the water reaches the hollow part.

Since the hollow fibers of the present invention have the above-mentioned special communicating micropores, water is quickly guided to the hollow portion through the communicating micropores, and exhibits extremely excellent water absorbency due to capillary action utilizing the hollow portions. .

The hollow fibers of the present invention have the above-mentioned communicating micropores, and contain 0.1 to 2% by weight of polyoxyalkylene glycol insoluble in the polyester constituting the hollow fibers and 0.1 to 2% by weight of an organic sulfonic acid metal salt represented by the following general formula. 1% by weight, and in particular, it is necessary that a part of the polyoxyalkylene glycol be dispersed around the hollow part at a high concentration.

The polyoxyalkylene glycol may be a single polyoxyalkylene glycol or a copolymerized polyoxyfulkylene glycol of two or more types, as long as it is substantially insoluble in polyester. The terminal may be an -OH group or may be blocked with an organic group that does not have ester-forming properties, and may further be bonded to another organic group that has ester-forming properties via an ester bond, ether bond, or carbonate bond. You can leave it there. Preferred specific examples (7) include polyoxyethylene glycol with a molecular weight of 4.000 or more, polyoxypropylene glycol and polyoxytetramethylene glycol with a molecular weight of 1.000 or more, and ethylene oxide and propylene oxide with a molecular weight of 2.000 or more. =1 copolymer, molecular weight 4,00
Examples include trimethylolethylene oxide adducts with a molecular weight of 0 or more, nonylphenol ethylene oxide adducts with a molecular weight of 3,000 or more. Particularly preferred is a molecular weight of 1
Polyoxyethylene glycol from 0,000 to less than 100,000, molecular weight io, o oo to 30.000
1= of ethylene oxide and propylene oxide
It is a random copolymer with a ratio of 3 to 3:1.

From the viewpoint of hygroscopicity, the amount of polyoxyalkylene glycol to be blended is preferably in the range of 0.1 to 2 by weight relative to the weight of the hollow fibers.

If it is less than 0.1% by weight, sufficient hygroscopicity cannot be obtained;
If it exceeds % by weight, the alkali resistance of the fibers will deteriorate, and the hygroscopicity will on the contrary decrease, and at the same time, the strength and fibrillation resistance of the fibers will become insufficient. Especially 0.2
A range of 1.0% by weight is particularly preferred.

In the general formula R8O and M representing the organic sulfonic acid metal salt used in combination with the polyoxyalkylene glycol, R is a furkyl group having 3 to 30 carbon atoms, or an aryl group or alkylaryl group having 7 to 40 carbon atoms, and R is In the case of a furkyl group or an alkylaryl group, it may be linear or may have a branched side chain and have a temperature as low as 0.degree. M is Na, K,
It is an alkali metal such as Li. Such organic sulfonic acid metal salts can be used alone or as a mixture of two or more.

Preferred specific examples of such metal organic sulfonates include sodium stearylsulfonate, sodium octylsulfonate, sodium dodecylsulfonate, and furkylsulfonic acid having 8 to 20 carbon atoms and an average carbon number of 14. Examples include sodium mixture, sodium todecylbenzenesulfonate (soft type, hard type), lithium dodecylbenzenesulfone (soft type, bar), sodium nonylbenzenesulfonate, and the like.

The content of the organic sulfonic acid metal salt is suitably in the range of 0.1 to 1% by weight based on the weight of the hollow fibers from the viewpoint of hygroscopicity. If it is less than 0.1% by weight, sufficient a humidity cannot be obtained, and if it exceeds 2% by weight, the alkali resistance of the fiber will be poor, which will not only reduce the moisture absorption of the fiber, but also reduce the strength and strength of the fiber. Fibril resistance becomes insufficient. Among these, a range of 0.2 to 0.5% by weight is particularly preferable.

The dispersion state of the polyoxyfulkylene glycol in the hollow fiber of the present invention will be explained with reference to FIG. FIG. 2 is a schematic diagram of a cross-sectional image obtained by subjecting the polyester hollow fiber of the present invention to osmic acid staining and observing it using a transmission electron microscope. As is clear from FIG. 2, in the polyester hollow fiber of the present invention, the polyoxyalkylene glycol is dispersed at a high concentration around the hollow portion. In Figure 2, the black dot is polyoxyalkylene glycol 0, p
indicates communicating micropores. According to the results of numerous studies conducted by the present inventors, if the polyoxyalkylene glycol was uniformly dispersed throughout the fiber cross section, the hygroscopicity would be insufficient, and the polyoxyalkylene glycol would be dispersed around the hollow part. In order to exhibit excellent hygroscopicity, it is essential that the material be dispersed at a higher dispersion density than other parts. In particular, it is preferable that at least half of the polyoxyalkylene glycol contained in the hollow fibers, more preferably at least 70%, be present in the area around the hollow portion, which is within 1/2 of the thickness of the hollow wall. The dispersion state of polyoxyfulkylene glycol was examined using a transmission electron microscope.
A cross-sectional section of a hollow fiber can be observed at a magnification of about a, o o o times or more. In particular, it is preferable to dye the hollow fibers with osmic acid and observe them.

The polyester used in the present invention has terephthalic acid as the main acid component, and has at least one type selected from fullylene glycol having 2 to 6 carbon atoms, that is, ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol. The main glycol component is preferably polyester containing ethylene glycol as the main glycol component.

Such a polyester may be modified by replacing a portion of its acid component terephthalic acid with another difunctional carboxylic acid.

Such other carboxylic acids such as inphthalic acid, 5-sodium sulfoiphthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, β-oxyethoxybenzoic acid, p-oxybenzoic acid, etc. Examples include difunctional aromatic carboxylic acids, difunctional aliphatic carboxylic acids such as sebacic acid, adipic acid, and oxalic acid, and difunctional alicyclic carboxylic acids such as 1,4-cyclohexanedicarboxylic acid.

Also, a part of the glycol component of the polyester may be replaced with another glycol component (such glycol component may include the above-mentioned glycol other than the main component and other diol compounds, such as cyclohexane-1,4-dimetatool, neopentyl glycol). , bisphenol A.

Examples include aliphatic, alicyclic, and aromatic diol compounds such as bisphenol S, polyoxyalkylene glycol, and the like.

Such polyesters can be obtained by any manufacturing method. For example, regarding polyethylene terephthalate, terephthalic acid and ethylene glycol may be directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate may be transesterified with ethylene glycol, or terephthalic acid and ethylene oxide may be transesterified. The first stage reaction is to react with the glycol ester of terephthalic acid and/or its low-polymerized product, and the second stage is to carry out a polycondensation reaction by heating the product under reduced pressure until the desired degree of polymerization is reached. It is easily produced by the reaction of

The polyester hollow fiber of the present invention comprises 0.1 to 10% by weight of a sulfocarboxylic acid metal salt represented by the following general formula (1), 0.1 to 2% by weight of a polyoxyalkylene glycol insoluble in polyester, and 0.1 to 2% by weight of a polyoxyalkylene glycol insoluble in polyester; 11% 0.1 to 1% by weight of an organic sulfonic acid metal salt represented by the formula % () is blended into a polyester, the resulting mixed polyester is melt-spun to form hollow fibers, and the core hollow fibers are formed into an aqueous solution of an alkali compound. It can be easily produced by eluting at least 2 weight or more of it.

In the above production method, the above formula (in 11, Ml and M
l is a metal, and M'' is preferably an alkali metal, a group I metal of the periodic table, Mnl/2, Co 1/2 [7(,
Among them, Lt T x + Cat/21Mfl/2 is particularly preferred. As Ml, alkali metals and alkaline earth metals are preferable, and among them, Li, Na, and K are particularly preferable. Ml and BP may be the same or different.

n is 1 or 2. R is a hydrogen atom, an alkyl group, or an ester-forming functional group, and the fulkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and the ester-forming functional group is -COOR' (where R' is a hydrogen atom, C1-C4 alkyl group or phenyl group) or -CO+0
(Ca)z)mOH (where t is an integer of 2 or more, m is 1
An integer greater than or equal to ) is preferred.

Preferred specific examples of such sulfocarboxylic acid metal salts include 3-carbomethoxybenzenesulfonic acid Na-5-
Sodium carboxylate, 3-carbomethoxybenzenesulfonic acid, -5-carboxylic acid, Na 3-carbomethoxybenzenesulfonic acid, Cal 5-carboxylate/2.3-carbomethoxybenzenesulfonic acid Na-5-carboxylic acid M
fl/2.3-hydroxyethoxycarbonylbenzenesulfonic acid Na-5-carboxylic acid Mfl/2, 3-carboxybenzenesulfonic acid Na-5-carboxylic acid M
nl/2.3-hydroxyethoxycarbonylbenzenesulfonic acid Na-5-carboxylic acid Znl/2, benzenesulfone 5! Na-3,5-di(carboxylic acid Li)
, Na-315-dibenzenesulfonic acid (K carboxylic acid), Na-3,5-di benzenesulfonate (Cal/2 carboxylic acid), Na-3,5-di benzenesulfonate
Examples include di(carboxylic acid Mfl/2), m-Na sulfobenzoate, and 5-Na sulfo-m-)ruyl acid Na.

Only one type of the sulfocarboxylic acid metal salt is used alone.
Also, two or more types may be used in combination.

If the amount of the sulfocarboxylic acid metal salt used is too small, the water absorbency and hygroscopicity of the hollow fibers finally obtained will be insufficient; on the other hand, if it is too large, troubles will not only easily occur during spinning. Since the strength and fibrillation resistance of the fibers will be insufficient, the amount used should be in the range of 0.1 to 10% by weight, preferably in the range of 0.3 to 5% by weight.

The polyoxyalkylene glycol and general formula (
The organic sulfonic acid metal salt represented by 11R8O,M is as described above.

The sulfocarboxylic acid metal salt, polyoxyfulkylene glycol, and organic sulfonic acid metal salt may be added at any stage before the spinning process of spinning polyester into hollow fibers.
It may be added during the synthesis of the polyester, or it may be added after the synthesis is completed and before melt spinning. Also,
You can add them in any order.

K, in which a mixed polyester containing the above compounds is melt-spun into hollow fibers, does not need to employ any special method (although any ordinary melt-spinning method for polyester hollow fibers may be employed.

It is necessary to remove part of the hollow fiber thus obtained! After subjecting the fabric to heat stretching or false twisting depending on the fabric, or after making it into a fabric, it is immersed in an aqueous solution of an alkali compound, or the aqueous solution of an alkali compound is subjected to a pad/steam treatment. can.

Examples of the alkali compounds used here include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate, potassium carbonate, and the like. Among them, sodium hydroxide and potassium hydroxide are particularly preferred.Also, alkaline weight loss accelerators such as cetyltrimethylammonium bromide, lauryldimethylbenzylammonium coolide, etc. can be used as appropriate.

The amount of weight loss due to treatment with this aqueous solution of an alkali compound should be in the range of 2% by weight or more of C based on the weight of the fibers.If the weight loss rate is less than 2% by weight, satisfactory micropores will not be formed and sufficient water absorption will not be achieved. properties and hygroscopicity cannot be obtained.

As described in detail of the invention, the polyester hollow fiber of the present invention has special micropores that communicate from the fiber surface to the hollow part, and polyoxyalkylene glycol is dispersed in a high concentration around the hollow part. It exhibits not only excellent water absorption but also excellent hygroscopicity, and maintains the quick drying and easy care properties that are characteristic of polyester fibers, so it also has excellent water release and moisture release properties.

For this reason, in an atmosphere where insensible evaporation (vapor phase moisture) occurs when the human body exercises or is exposed to a tendency to increase body temperature such as high temperatures, water in a gaseous state absorbs and desorbs moisture from inside clothing to the outside world. As a result of the smooth transport through the mechanism, the humidity inside the garment is maintained at a low level, making it extremely comfortable to wear.

On the other hand, even in an atmosphere accompanied by sweating, the polyester fiber of the present invention has a water retention rate that is much higher than that of conventional polyester fibers and has been improved to the same level as that of cotton pots, which allows it to absorb sweat and transport it. It absorbs sweat faster than cotton, so it does not leave sweat on the skin, and even when sweat is absorbed, the physical properties of the fiber itself do not change, and there is no decrease in bending stiffness or moisture permeability, so it does not leave sweat on the skin. It does not get sticky and provides a comfortable fit. In addition, it dries quickly and has a high moisture perception limit, so you won't feel the cold sensation that lasts for a long time after exercise.Also, you can wear it directly on your skin. In addition to not causing irritation to the skin, it has a special micropore structure that provides excellent heat retention and pill resistance.Furthermore, the hollow fiber of the present invention is made by combining polyoxyalkylene glycol organic sulfonic acid metal salt with a special Since it is contained in a dispersed state, it also has excellent antistatic properties.

Note that the polyester fiber of the present invention may contain optional additives, such as catalysts, color inhibitors, heat resistant agents, flame retardants,
A fluorescent whitening agent, a matting agent, a coloring agent, inorganic fine particles, etc. may be included.

f. Examples The following examples are given below to further explain the temperature. In the examples, parts and ti indicate parts by weight and % by weight, respectively, and the water absorbency and hygroscopicity of the resulting fibers were measured by the following method.

(1) Water absorption rate test method (according to JIS-L1018 K) The fibers were made into a cloth, and the cloth was washed with a 0.3% aqueous solution of 7-ionic detergent Zabu (manufactured by Kako Soap Co., Ltd.) at 40°C in a household electric washing machine. Repeat washing for 30 minutes a specified number of times, then dry the resulting sample horizontally, and drop one drop of water (0.04cc) from the height of the top of the sample until the water is completely absorbed into the sample. , measure the time until reflected light is no longer observed.

(II) Water holding rate measurement method A sample obtained by drying a fabric is immersed in water for 30 minutes or more, and then dehydrated for 5 minutes in a dehydrator of a household electric washing machine. It was calculated from the weight of the dry sample and the weight of the sample after dehydration using the following method.

all) Moisture absorption rate measurement method It was determined by the following formula from the absolute dry weight of the sample and the weight at a predetermined temperature and relative humidity.

Example 1 100 parts of dimethyl terephthalate, 6 parts of ethylene glycol
0 parts and 0.06 parts of calcium acetate monohydrate are charged for each transesterification, and the temperature is raised from 140°C to 230°C over 4 hours under a nitrogen gas atmosphere. Transesterification is carried out while distilling the generated methanol out of the system. Made it react. The resulting product was then treated with benzenesulfone 11Na- as a micropore-forming agent.
20 parts of 5% ethylene glycol solution of 3,5-di(carboxylic acid Mf1/2), 0 parts of phosphorus trimethyl as a stabilizer
．． 06 parts and 0.0 7thmony trioxide as a polycondensation catalyst
4 parts were added and transferred to a polymerization mortar. Then over an hour 7
The pressure was reduced from 60 mmH7il to 1111 IHg [5], and at the same time the temperature was raised from 230°C to 285°C over 1 hour and 30 minutes. Two hours after the start of reduced pressure, 0.8 part of polyethylene glycol having an average molecular weight of 20,000 and 0.4 part of a mixture of sodium furkylsulfonate having 8 to 20 carbon atoms and an average carbon number of 14 were added under reduced pressure. Continue stirring 1■
■Polycondensation reaction is carried out for 1 hour under reduced pressure of 9°C or less, and the intrinsic viscosity is 0.
640 and a softening point of 262°C was obtained. After the reaction was completed, the polymer was made into chips using a conventional method.

This polymer was melt-spun and stretched according to a conventional method to obtain 75
A hollow fiber multifilament with a denier/24 filament and a hollow ratio of 20 cm was obtained.

This hollow fiber multifilament was knitted into a knitted fabric, scoured and preset by a conventional method, and then treated with a 5 to 3% aqueous sodium hydroxide solution at boiling temperature to achieve a weight loss of 20 inches.

The single fibers of this alkali-treated cloth were examined under an electron microscope with a
FIG. 1 is an enlarged photograph, and FIG. 2 is a schematic diagram of a transmission electron micrograph of a cross-sectional section of this single fiber (stained with osmic acid). Figures 1 and 2 show that the hollow fibers have micropores with a diameter of 0.01 to 3 μm that communicate from the fiber surface to the hollow part, and that the blended polyoxyalkylene glycol is dispersed in a high concentration around the hollow part. It is clear that the

Table 1 shows the water absorption and moisture absorption characteristics of the resulting fabric after the alkali treatment, in comparison with the water and moisture absorption characteristics of the fabric before the alkali treatment.

Example 2 Benzenesulfonic acid Na-L5-di(carboxylic acid Mt1/2) used as a micropore forming agent in Example 1
K replaced with 3-carbomethoxybenzenesulfonic acid N
The same procedure as in Example 1 was carried out except that a-5-carboxylic acid Na was used and this was dispersed in the polymer at a concentration of 2%.

Results first! ! It was shown to.

Example 3 In place of 0.4 part of the mixture of sodium alkylsulfonate having 8 to 20 carbon atoms and an average carbon number of 14 used as the organic sulfonic acid metal salt component in Example I, sodium dodecylbenzenesulfonate (hard salt) was added. The same procedure as in Example 1 was carried out except that 0.4 part was used.The results are shown in Table 1.

Comparative Example 1 The same procedure as Example 1 was carried out except that both polyethylene glycol and sodium alkylsulfonate used in Example I were not used. The results are shown in Table 1.

Comparative Example 2 Benzenesulfonic acid Na-3+ 5-di(carboxylic acid Mt1/2) used as a micropore forming agent in Example 1
) The procedure of Example 1 was repeated except that 1 part of monomethyl di-N&1 phosphate was used instead of 1 part. The results were as shown in Table 1.

[Brief explanation of drawings]

FIG. 1 is an electron micrograph of the polyester hollow fiber of the present invention magnified 2.400 times, and FIG. 2 is a schematic cross-sectional view of the polyester hollow fiber of the present invention.

Claims (1)

[Scope of Claims] 1. Hollow fibers made of polyester, the hollow fibers being fine particles with a diameter of 0.01 to 3 μm and communicating from the fiber surface to the hollow portion. 0.1 to 2% by weight of polyoxyalkylene glycol which has pores and is substantially insoluble in the polyester constituting the hollow fibers and the following general formula RSO_2M [wherein R is an alkyl group having 3 to 30 carbon atoms or a carbon number 7-40 aryl group or alkylaryl group, M represents an alkali metal. ] A hollow fiber containing 0.1 to 1% by weight of an organic sulfonic acid metal salt represented by the formula, and in which a portion of the polyoxyalkylene glycol is dispersed at a high concentration around the hollow portion. 2. Polyester has the following general formula (I) ▲Mathematical formula, chemical formula, table, etc.▼・・・・・・・・・
(I) In the formula, M^1 and M^2 are metals, n is 1 or 2, R^1
represents a hydrogen atom, an alkyl group, or an ester-forming functional group. 0.1 to 10% by weight of a sulfocarboxylic acid metal salt represented by, 0.1 to 2% by weight of a polyoxyalkylene glycol insoluble in the polyester, and the following general formula (II) RSO_2M... II) In the formula, R represents an alkyl group having 3 to 30 carbon atoms, an aryl group or alkylaryl group having 7 to 40 carbon atoms, and M represents an alkali metal. 0.1 to 1% by weight of the organic sulfonic acid metal salt represented by is blended, melt-spun to form hollow fibers, and the obtained hollow fibers are treated with an aqueous solution of an alkaline compound to elute at least 2% by weight. A method for producing hollow fibers characterized by: