JPH03146710A - Hygroscopic polyester fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber having an excellent washing resistance in addition to hygroscopicity peculiar to a polyester fiber by blending a sulfonic acid group-containing component having a metal atom of a specified hydration number and a carboxylic acid-based polymer. CONSTITUTION:To (A) a polyester fiber, (B) a sulfonic acid type comonomer [e.g. 3,5-di(carbomethoxy)benzenesulfonic acid salt] is added and copolymerized so that a metal salt of a sulfonic acid group-containing a component in which the metal has >=1.5 hydration number represented by [hydration number = (electric charge of metal ion)/(radius (Angstrom ) of metal ion)] and ions in an amount of >=0.1 g ion per 1kg fiber may be contained, and furthermore, (C) a carboxylic acid-based polymer is added thereto in an amount of <=5wt.% (based on fiber weight), thus obtaining the objective fiber.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to hygroscopic polyester fibers.

More specifically, the present invention relates to polyester fibers that have the characteristics of polyester fibers and have wash resistance.

(Prior art and problems to be solved by the invention) Polyesters, especially aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, have excellent fiber forming ability and excellent performance as fibers. Wide <- Used for boat fishing.

However, such polyesters are hydrophobic and
The fibers obtained by molding these fibers have poor moisture absorption, which is closely related to comfort, making it extremely difficult to apply them to the inner wear or nightwear fields.

Therefore, many proposals have been made to impart hygroscopic properties to polyester fibers, but few have been put to practical use yet.

For example, to impart hygroscopicity to polyester fibers,
A method of blending polyalkylene and glycol at a stage before spinning (British Patent No. 682866, or Japanese Patent Publication No. 39-1989)
5214) etc. have been proposed. However, the level of hygroscopicity obtained with this method is low and unsatisfactory.

Furthermore, a hygroscopic polyester fiber (Japanese Patent Publication No. 7285/1983) has been proposed in which a specific oxalate is blended and a portion of the fiber is eluted in a process after spinning to form capillary condensation pores. However, the moisture absorption level of this fiber is far from that of nylon.

In addition, polyester fibers containing metal sulfonate compounds are treated with alkali to form capillary condensation pores and impart hygroscopicity (Japanese Patent Laid-Open No. 60-1557
70'), but as above, the hygroscopicity level has not reached a satisfactory level.

Furthermore, a method of graft polymerizing vinylcarboxylic acid to polyester fibers to improve moisture absorption capacity is also known as a known technique. However, in order to improve the hygroscopicity using this method and obtain the comfort that comes from eliminating stuffiness by imparting a hygroscopic function, it is necessary to make a considerable change in the fiber performance due to modification, and to improve the fiber strength. decline in
It is known that defects such as hand hardening occur.

Furthermore, the counter ion of carboxylic acid is Li.

Alkali metals such as Na and Ni have high hygroscopicity;
Due to the substitution with polyvalent metal ions due to washing, etc., the hygroscopicity is greatly reduced, and for this reason, there are almost no examples of practical use.

In addition, a proposal has been made to copolymerize polyester with a metal sulfonate compound and specify the type of metal atom to improve its hygroscopicity, but the hygroscopicity of the resulting polyester fiber is far from that of natural fiber. level.

Therefore, the same applicant as the present invention filed an application for "hygroscopic polyester fiber" on July 11, 1988 (Japanese Patent Application No. 1988-
No. 170878), the copolymerized metal salt of the sulfonic acid group-containing component has a hydration index and contains at least O per kg of fiber weight.
We proposed a hygroscopic polyester fiber characterized by containing 0.1g ions. Although the hygroscopicity of this fiber is improved over that of conventional polyester fibers, it is lower than that of natural fibers, and the hygroscopicity is still insufficient for use, particularly in the innerwear or nightie fields.

The present invention has excellent hygroscopicity comparable to natural fibers without impairing the properties of polyester fibers,
The object of the present invention is to provide a polyester fiber that also has washing resistance.

[Means to solve the problem]

The object of the present invention is that the copolymerized metal salt of the sulfonic acid group-containing component is composed of metal atoms with a hydration index of 1.5 or more, and contains at least 0.1 gram ion per kg of fiber weight, and This is achieved by using a hygroscopic polyester fiber characterized by containing 5% or less of a carboxylic acid polymer.

However, the hydration index is expressed by the following formula.

As mentioned above, the hydration index in the present invention is a value obtained by dividing the metal ion valence number by the metal ion radius (inclusion), and is a parameter representing the degree of hydration ability of each metal ion. The metal ion radius here refers to the bond radius in the ionic compound of the metal, and when calculating the hydration index in the present invention, R, D, 5hannon (Ac
ta Crystallogr,)+^32.751~
The values on page 767 (1976) were used, the coordination number was unified to 6, and the values in the low spin state were used for transition metals.

Below, to illustrate the hydration index of each metal ion, Li""
(1,11), Na” (0,86), Mg” (2,
82), K” (0,66).

Ca" (1,75), Rh" (0,60), Cs'
(0,55), Be'' (3,39).

Ba” (1,34), Mn” (2,47), Co”
(2,53), Ni”.

(2,41), Cu” (2,30), Aj?”(
4,41), Sn"" (4,82).

Zn2°(2,27), Cr”(2,30), Mo
”(3,61), among which Li”, Na”,
With metal ions such as K'', Rh'', and Cs'' with a hydration index of less than 1.5, it is difficult to obtain satisfactory hygroscopicity even by increasing the amount of the metal, and as a result, This is undesirable because it reduces the fiber performance of polyester.Also, in order to obtain satisfactory hygroscopicity, the hydration index is 1.
．． It is important that the fiber contains at least 0.1 gram ion or more, more preferably 0.25 gram ion or more, of 5 or more metal ions per kg of fiber weight. 0.
If the amount of ions is less than 1 gram, no matter how high the hydration index of the metal ion species is, almost no moisture absorption effect will be observed.

In the present invention, the method for introducing a sulfonic acid metal base chemically bonded to polyester fibers is to add a sulfonic acid type comonomer, which is a metal salt of a metal atom with a high hydration index, before the start of the polymerization reaction. There is a way,
Furthermore, the salt of the sulfonic acid component is added and polymerized as a comonomer of an alkali metal salt of -tansulfonic acid, and the copolymerized salt of the sulfonic acid component is treated with a solution containing the metal ion, and the salt of the sulfonic acid component is treated with a solution containing the metal ion. Although there is a method of substitution, the latter is preferable, and more specifically, it is preferable to carry out the sodium salt treatment described below after graft polymerization.

The sulfonic acid type comonomer that can be used in the present invention may be any compound that is substantially copolymerizable with polyester and has a sulfonate group, such as metal 3,5-di(carbomethoxy)benzenesulfonate. salt, 3,5-bis(hydroxyethoxy)benzenesulfonic acid metal salt, 1,8-di(carbomethoxy)naphthalene-3-sulfonic acid metal salt, 2,6-di(carbomethoxy)naphthalene-4-sulfonic acid Metal salt, l・5-di(
carbomethoxy) naphthalene-3-sulfonic acid metal salt,
3,4-di(carbomethoxy)benzenesulfonic acid metal salt, 2,5-bis(2-hydroxyethyl)ether-
Hydroquinone-sulfonic acid metal salt, 2,2-bis(4
-Hydroxyethoxy-benzene-3-sulfonic acid metal salt)-propane, 2,5-bis(2-hydroxyethyl)ether-hydroquinone-disulfonic acid dimetal salt, and the like.

The timing of polymerization addition of these metal sulfonate compounds is, in the case of lower alkyl esters such as 3,5-di(carbomethoxy)benzenesulfonic acid metal salts, before the start of the transesterification reaction;
In the case of bisglycol esters such as benzenesulfonic acid metal salts or ethers such as 2,5-bis(2-hydroxy)ether-hydroquinone-sulfonic acid metal salts, after the start of the transesterification reaction and before the end of the transesterification reaction, Alternatively, it is preferable that the reaction is carried out before the start of the polycondensation reaction. Methods for substituting sulfonic acid salts with metal ions in the post-process include - A simple processing method For example, in the dyeing process, by dissolving a water-soluble metal salt of the metal in the dye bath, substitution can be carried out while dyeing. It is also possible to replace metal ions by treating them in a water bath containing metal ions in the finishing process after dyeing. Other methods such as a pad steam method can be applied, but are not particularly limited. The heating temperature and treatment time at that time are 130°C above the glass transition temperature of the copolymerized polyester.
Less than 30 minutes to 180 minutes is appropriate.

Substitution is insufficient below the glass transition temperature, and 13
If the temperature is higher than 0°C, partial hydrolysis of the copolymerized polyester will occur, which is not preferable. Furthermore, if the treatment time is less than 30 minutes, the substitution will be insufficient, and the metal substitution will reach saturation within 180 minutes. On the other hand, as the water-soluble metal salt, any inorganic salt or organic carboxylate of the metal can be selected. It can be used if Specifically, aluminum sulfate, manganese sulfate, zinc nitrate, cobalt sulfate, magnesium acetate, calcium chloride, beryllium sulfate, chromium nitrate, stannous sulfate, etc. can be mentioned.

The polyester used in the present invention refers to terephthalic acid as the main acid component and at least one selected from ethylene glycol, tetramethylene glycol, cyclohexane-1,4-dimethanol, pentamethylene glycol, and hexamethylene glycol as the main glycol component. polyester with a small amount, usually 1
The third component may be copolymerized in an amount of 0 mol % or less. As the copolymerizable third component, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, cyclohexane-1,4
Examples include dicarboxylic acids such as -dicarboxylic acid and p-oxybenzoic acid. Furthermore, polycarboxylic acids such as trimellitic acid and pyromellitic acid or polyols such as glycerin, trimethylolpropane and pentaerythritol can be used within the range where the polyester is substantially linear.

In the present invention, a preferred method for incorporating a carboxylic acid-based vinyl polymer into fibers is to first polymerize a monomer with an initiator to prepare a polymerization reaction solution. The initiator may be such as hendyl peroxide and its derivatives, azobisisobutyronitrile and its derivatives, or light energy, in combination with the initiator or if necessary, monochlorobenzene, benzyl alcohol, tetra Swelling agents such as chloroethane and nitrobenzene can be used, but are not particularly limited to those listed above. Next, regarding the polymerization step, the sample can be immersed in a polymerization reaction solution and heated as it is, a pad-steam method, a band-dielectric heating method, etc., but any method can be applied.

The monomers referred to in the present invention include acrylic acid, methacrylic acid,
Examples include itaconic acid and maleic acid, but there are no particular limitations as long as the monomer contains carboxylic acid.

The carboxylic acid polymer referred to in the present invention is in a state in which it is applied to a sample, but it is preferably in a state in which it has been exhausted to the inner structure of the sample, and more preferably in a state in which it has been graft-polymerized.

In the present invention, after applying the carboxylic acid polymer, a treatment is performed to convert the carboxylic acid terminal into a sodium salt, and a water-soluble slightly alkaline sodium salt is used as the treatment agent. In this case, a disodium hydrogen phosphate aqueous solution is preferably used, which causes less decrease in strength and elongation even when the treatment temperature is set to 80° C. or higher to increase the sodium substitution rate.

The fiber content of the carboxylic acid polymer in the present invention is 5
% or less, and if it exceeds 5%, the texture will harden,
If the elongation is lower than the strong elongation, the color fastness begins to deteriorate significantly, which is not preferable.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples.

Intrinsic viscosity was measured in orthochlorophenol at 35°C. In the examples, parts and % are parts by weight and % by weight, respectively.
shows. In addition, the moisture absorption rate in the examples refers to relative humidity 65
% in a constant temperature incubator (Tabai PR2G) at 20 °C.
It refers to the value obtained after being left for days, and was calculated using the following formula.

(A) Production of modified polyester polymer (K+) Dimethyl terephthalate 136.4 parts, ethylene glycol 99
1 part, manganese acetate, 0.064 part of tetrahydrate, 15.1 parts of dimethyl 5-sodium sulfoisophthalate (6.8 mol % in total acid components), 0.33 part of lithium acetate dihydrate, and prepared in a conventional manner. After distilling off methanol, 1-0,045 parts of trimethyl phosphate and 0.075 parts of antimony trioxide were added, and the pressure was reduced from normal pressure to 20 mmHg or less over 60 minutes at 260°C. 28 after
The reaction was carried out at 0°C under high vacuum for 50 minutes to obtain a polymer having an intrinsic viscosity of 0.33. This was made into chips by a conventional method, and then reacted in an evaporator at 210° C. under high vacuum for 25 hours by solid phase polymerization to give an intrinsic viscosity of 0.60. The content of metal sulfonate groups per kg of fiber of this polymer was 0.339.

(K2) Dimethyl terephthalate 144.7 parts, ethylene glycol 101 parts, manganese acetate tetrahydrate 0.064
parts, dimethyl 5-sodium sulfoisophthalate 6.8
(3.0 mol% of the total acid components) and 0.15 parts of lithium acetate dihydrate were added, but transesterification and polycondensation reactions were carried out in exactly the same manner as in (K1), and the intrinsic viscosity was 0.45.
got a tip. The content of metal sulfonate groups per fiber core of this polymer was 0.153.

(B) Manufacture of modified polyester yarn (K,) The chips obtained in (K) were dried for 12 hours using a tumble dryer.
After drying at 0°C for 20 hours, it was melted at 290°C in a spinneret with a diameter of 65φ and 24 circular spinning holes with a hole diameter of 0.25mm, and a heating cylinder with an inner diameter of 125φ and a length of 200mm was set under the spinneret, and the mixture was heated to 350°C. Winding speed 600m under heating
/ I wound it up. Then, by the usual method, the temperature was reduced to 10 - 5
°C, hot plate temperature = 140 °C1 stretching ratio: 4
．． 2. Stretching speed: 600 m/min, twist number 10 L/m to obtain a 75 denier 24 filament yarn.

On the other hand, (K2) was carried out in exactly the same manner as above except that the heating cylinder was not set, and a similar multifilament yarn was obtained. These were knitted using a circular knitting machine and used as samples for the next process.

Modified polyester polymer (K) and modified polyester polymer (B)
A knitted fabric sample was prepared using the manufacturing method described above, and was subjected to conventional scouring, presenting, and polymerization operations.

Specifically, the polymerization operation involved 1 part by weight of benzoyl peroxide as an initiator, 8 parts by weight of monochlorobenzene as a carrier (swelling agent), and 2 parts by weight of an emulsifier (Blysurf A 217E, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Dispersed in water 10
00 parts by weight as a treatment solution, a bath ratio of l to lOO, equal volumes of acrylic acid and methacrylic acid as monomers were added at 50% to the knitted fabric sample, and the solution was heated at a temperature of lOO''C to 60%.
The polymerization reaction was completed by immersion heating for a minute. Next, the grafted sample was placed in boiling water and boiled for 3 hours, and washed with hot water repeatedly to extract the homopolymer and unreacted monomer in the sample.

After that, the sample was completely dried and the content was measured.
It was 3%. Furthermore, the humidity of the sample was conditioned at 20° C. and 265% relative humidity (R, l+), and the moisture absorption rate was determined to be 1.5%. Thereafter, the sample was heated to 90°C using a 2% aqueous solution of disodium hydrogen phosphate decahydrate.
The carboxyl groups possessed by acrylic acid and methacrylic acid were converted to sodium salt by treatment at 20°C for 30 minutes.
The humidity conditioned weight was measured under 65% R, 11, and the moisture absorption rate was found to be 3.5%. Furthermore, the sample was 0.
The sample was boiled for 1 hour using 2% magnesium acetate to convert the sulfonic acid groups and carboxyl groups contained in the sample into magnesium salt, and the moisture absorption rate was determined as above: 6.2
%, and a large improvement in hygroscopicity was observed. Keikou X
When each atom was analyzed and quantified by the line, and the substitution rate of sodium salt to magnesium salt was determined, it was 78%, and the content rate of magnesium salt per 1 kg of fiber was 0.2.
It was 64 grams ion. Further, when the strength and elongation of the yarn of this sample was measured, the breaking strength was 2.9 g/α and the breaking elongation was 31%.

Further, this treated sample was placed in a washing bath containing 2 g/l of synthetic detergent Zabu Enzyme (manufactured by Kao Sekiken ■) and washed at 40°C for 30 minutes, followed by washing with water for 20 minutes. After repeating this washing with water 5 times, the same procedure as above was carried out. When the moisture absorption rate was measured, it was 6.1%. Since hard water was used in all of these washing processes, it can be said that no decrease in moisture absorption rate was observed due to hard water washing.

In addition, the content rate shown in an Example means the weight increase rate.

After scouring and prescenting the knitted fabric samples obtained in Examples (A) and (B), polymerization was performed in the same manner as in Example 1, and boiled in various metal salt aqueous solutions at a bath ratio of 1 to 110 for 1 hour. Table 1 shows the moisture absorption rate, breaking strength and elongation, content of substituted metal ions, and moisture absorption rate after washing with hard water. The content in the table is the carboxylic acid polymer content, and both are 5
% or less and the content of substituted metal ions is 0.1 gram ion or more per 1 kg of fiber weight, the moisture absorption rate becomes similar to that of natural fibers (cotton), and the moisture absorption rate decreases after washing with hard water. This shows that the strength and elongation can be maintained at a considerable level.

Comparative examples are summarized in Attached Table 2. In Comparative Examples 1 to 14, the content of substituted metal ions was lower than 0.1 gram ion, and therefore the moisture absorption rate was not sufficiently improved. Comparative Examples 15 to 18 were metal chlorinated using metal atoms with a hydration index of less than 1.5, so the content of substituted metal ions was higher than 0.1 gram ions, but the moisture absorption rate was sufficient. is not obtained. Comparative example, 19,
No. 20 achieved a moisture absorption rate comparable to that of natural fibers, but the application rate was too high, resulting in a significant decrease in strength and elongation.

〔Effect of the invention〕

The hygroscopic polyester fiber obtained by the method described above can achieve hygroscopic properties comparable to natural fibers by modifying it to contain a very small amount of carboxylic acid polymer. This is a drawback that occurs when applied to Deterioration of physical properties, hardening of texture, decrease of color fastness, etc. can be alleviated. In addition, when trying to make ordinary polyester fibers hygroscopic with a modification technique that involves only graft polymerization using carboxylic acid-based vinyl monomers, even if the terminal carboxyl group is converted into an alkali metal chloride to improve hygroscopicity, the hygroscopicity can be improved by washing with hard water. Although it was mentioned in the prior art that the properties of the polyester fibers decrease, the polyester fibers of the present invention do not show any decrease in moisture absorption performance even after washing with hard water.

Claims (1)

[Claims] 1. The copolymerized metal salt of the sulfonic acid group-containing component consists of metal atoms with a hydration index of 1.5 or more, and the fiber weight is 1 kg.
1. A hygroscopic polyester fiber containing at least 0.1 gram ion per fiber, and further comprising 5% or less of a carboxylic acid polymer based on the weight of the fiber. However, the hydration index is expressed by the following formula. Hydration index = Metal ion electric value / Metal ion radius (Å)