JP2003171824A - Hygroscopic polyester fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain polyester fibers which have excellent melt-viscosity characteristics and high hygroscopicity and can be used as a comfortable raw material for woven or knitted fabrics or the like, such as underwear, sportswear, and linings. <P>SOLUTION: The hygroscopic polyester fibers having excellent hygroscopicity and excellent melt viscosity characteristics contains silica-based inorganic particles and aluminum hydroxide-based particles. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester fiber having excellent hygroscopicity. More specifically, the present invention relates to a polyester fiber having high hygroscopicity and melt viscosity, which can be uniformly and stably produced, and thus has less yarn breakage during spinning, and has productivity and wearing comfort.

[0002]

2. Description of the Related Art Polyethylene terephthalate and other so-called polyesters are widely used for fibers, films, compositions and the like because of their excellent strength, thermal stability and chemical resistance. However, since polyethylene terephthalate is inherently hydrophobic, it has very poor moisture absorption and release properties, and when used as clothes, it may cause a "wrinkle" at high humidity or generate static electricity at low humidity in winter. However, it is not a preferable material in terms of wearing comfort.

In order to eliminate this drawback, for example, Japanese Patent Laid-Open No. 48
Copolymerization of a diol having an oxyalkylene glycol in the side chain, as proposed in JP-A-8270,
A method of copolymerizing a compound having a hygroscopic property with a polyester, such as copolymerization of a dicarboxylic acid containing a sulfonic acid metal salt in JP-A 2-26985, has been proposed. However, there are major problems that the entire polymer is modified by copolymerizing the hygroscopic component, the weather resistance is lowered, and the original advantage of polyester such as excellent mechanical properties is lost.

Further, as disclosed in JP-A-52-74020, hygroscopicity is imparted by graft-polymerizing acrylic acid or methacrylic acid on polyester fibers and substituting their carboxyl groups with alkali metals. It is known how to do it. However, it has not been put to practical use because it has problems of deterioration of light resistance, generation of slime due to adhesion of moisture absorbing part to composition or fiber surface layer, and deterioration of strength over time.

In order to solve these problems, in fiber applications, a core-sheath type composite fiber in which a hygroscopic resin having high hygroscopicity is used as a core portion and covered with a polyester sheath portion is disclosed in JP-A-2-99.
It is proposed in Japanese Patent Application Laid-Open No. 612, Japanese Patent Application Laid-Open No. 4-361616, Japanese Patent Application Laid-Open No. 4-341617, Japanese Patent Application Laid-Open No. 9-132871 and the like. However, in the case of these core-sheath type composite fibers, the hygroscopic resin of the core part swells greatly due to the inclusion of water during hot water treatment such as scouring and dyeing, so that cracks (sheath cracks) occur on the fiber surface, and There is a defect that the fabric quality is deteriorated such that the resin flows to the outside and the dyeing fastness is significantly deteriorated. For the purpose of suppressing this sheath cracking, a method of previously providing a hollow portion adjacent to the hygroscopic core component from the stage of melt spinning is disclosed in Japanese Patent Laid-Open No. Hei 10
9-111579 and JP-A-52-55721, it is proposed that even when the fiber is formed into a shape having a hollow portion, the hollow portion is formed when the fiber is twisted or false twisted. However, there is a drawback in that, as in the case described above, the sheath cracks due to the swelling of the hygroscopic polymer occur due to the subsequent crushing of hot water.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide a polyester fiber which overcomes the above-mentioned problems of the prior art and has a high moisture absorption performance and a high melt viscosity while maintaining the excellent properties of polyester. Especially.

[0007]

[Means for Solving the Problems] The above-mentioned problems are as follows: 1 to 20% by weight of silica-based inorganic particles having a pore volume of 0.5 ml / g or more and a specific surface area of 500 m ² / g or more, and an average particle diameter of 1 The problem can be solved with a hygroscopic polyester fiber containing 0.05 to 5% by weight of aluminum hydroxide particles having a particle size of 100 nm.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The contents of the present invention will be specifically described below.

In the present invention, the pore volume is 0.5 ml / g
As described above, the silica-based inorganic particles having a specific surface area of 500 m ² / g or more are essential components for imparting hygroscopicity to the fiber, and specifically, 50% or more of the particles are particles composed of SiO ₂ , White carbon, silica sol, silica gel and the like can be mentioned, and silica having a SiO ₂ content of 95% or more is preferable, and wet silica is more preferable.

The silica-based inorganic particles used in the present invention preferably have a specific surface area of 500 m ² / g or more. When this specific surface area is small, only those having insufficient moisture absorption performance can be obtained.

The silica-based inorganic particles used in the present invention preferably have a pore volume of 0.5 (ml / g) or more. When the pore volume is small, only those having insufficient moisture absorption performance can be obtained.

The average particle size of the silica-based inorganic particles used in the present invention is 0.0 because of the thickening property during polymerization and melt moldability.
1 to 10 μm is preferable. The more preferable average particle diameter of the silica-based inorganic fine particles is 0.1 to 5 μm.

The silica-based inorganic particles used in the present invention
Is 3 / nm from the viewpoint of hygroscopicity ²More silano
It is preferable that the ru basis be present on the surface of the particle.

Further, the moisture absorption rate of the silica-based inorganic particles in the standard state is to increase the hygroscopicity of the synthetic fiber using the same,
It is preferably as high as possible, but preferably 20% or more, and more preferably 25% or more.

The polyester fiber of the present invention must contain aluminum hydroxide particles having an average particle diameter of 1 to 100 nm. By using both of them together, not only the hygroscopic performance can be maintained, but also a rapid increase in melt viscosity at the synthetic stage of polyester can be suppressed and the degree of polymerization can be increased. The aluminum hydroxide-based particles are represented by alumina hydrate having a fine colloidal size, and examples thereof include gibbsite, bayerite, and boehmite. A generic name for such compounds is called alumina sol. As the form of the obtained aluminum hydroxide-based particles, water, those dispersed in an organic solvent,
It can be used depending on the purpose, such as dried particles. Preferably, a product dispersed in ethylene glycol, which is a synthetic raw material for polyester, can be used, but it is produced by substituting ethylene glycol for the sol obtained in an aqueous system.

The average particle size of the aluminum hydroxide-based particles is preferably 1 to 100 nm in order to suppress a rapid increase in viscosity and increase the degree of polymerization of polyester. A more preferable average particle diameter is 5 to 50 nm.

Further, the aluminum hydroxide particles preferably have an aspect ratio represented by a major axis and a minor axis of 2 to 20 for the purpose of suppressing the interaction between the silica inorganic particles.

As a method for producing such aluminum hydroxide-based particles, known techniques such as the Bayer method using bauxite and sodium aluminate can be used. It is preferable to contain at least one stabilizer selected from hydrochloric acid, nitric acid, and acetic acid.

From the viewpoint of mechanical properties, the polyester used in the present invention comprises 80% by mole or more of alkylene terephthalate repeating units. For example, polyethylene terephthalate, poly-1,3-propylene terephthalate, polyethylene-2, 6-naphthalene dicarboxylate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, and the like. Among them, polyethylene terephthalate, poly-1,3-from the viewpoint of strength and light resistance when formed into fibers.
Propylene terephthalate is preferred.

The polyester containing ethylene terephthalate as a main repeating unit may be copolymerized with another third component as long as the object of the present invention is not impaired. For example, as a compound that can be used instead of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, etc., aromatic, aliphatic, Examples thereof include alicyclic dicarboxylic acids and their derivatives. Examples of diol compounds that can be used instead of ethylene glycol include propylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, polyalkylene glycol, bisphenol A, bisphenol S.
Examples of such aromatic, aliphatic, and alicyclic diol compounds include: If necessary, these polymers may contain a matting agent, an antistatic agent, a deodorant, a fine pore forming agent, and the like.

For the purpose of improving the hygroscopicity of the polymer itself, it is preferable to copolymerize 0.5 to 20 mol% of sulfoisophthalic acid metal salt. The copolymerization ratio of these is more preferably 1 to 10 mol% from the viewpoint of sufficient moisture absorption and desorption and strength.

For the same purpose, a molecular weight of 600-20
5,000 polyoxyalkylene glycol 0.5-1
Copolymerization is preferably 5% by weight, more preferably 2
10 to 10% by weight. Specific examples of the polyoxyalkylene glycol used include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene oxide / polypropylene oxide block copolymer, polyethylene oxide / polytetramethylene oxide block copolymer, polypropylene oxide / polytetraglycol. Examples thereof include methylene oxide block copolymer, and polyethylene glycol is preferable.

The amount of silica-based inorganic particles used in the present invention is 1 to 20% by weight. If the addition amount is less than 1% by weight, the moisture absorption and desorption properties of the polyester composition will be insufficient,
On the other hand, if it exceeds 20% by weight, the melt viscosity of the composition becomes extremely high and molding becomes difficult. A more preferable addition amount is 5 to 15% by weight. Further, the addition amount of the aluminum hydroxide-based particles is 0.05 to the polyester from the viewpoint of the effect of increasing the degree of polymerization of the polyester composition and heat resistance.
5% by weight is preferred. More preferable addition amount is 0.1 to 2
% By weight.

In order to obtain practical wear comfort, the moisture absorption rate of the synthetic fiber in the standard state is preferably 1.0% or more, more preferably 1.5% or more.

In the present invention, the method for incorporating the silica-based inorganic particles and the aluminum hydroxide-based particles in the polyester may be any one of esterification or transesterification reaction of the polyester, polycondensation reaction, polycondensation reaction and before melt molding. In this step, the silica-based inorganic particles and the aluminum hydroxide-based particles that have been mixed in advance with a homomixer or the like may be added to the synthesis step, or they may be individually added and mixed in the reaction vessel. Good. In addition, it goes without saying that both may coexist at the stage of dispersing and pulverizing the silica-based inorganic particles in a solvent.

As a method for producing a fiber using the polyester of the present invention, a conventionally known method can be used. The production method is shown below. The silica-based inorganic particles and the alumina sol-containing polyester are melted, introduced into a spinning pack, and spun from the spinneret discharge hole.

The spun filament yarn is taken up at a predetermined speed, wound up once in a package, and the obtained undrawn yarn is drawn by a usual drawing machine. Further, this drawing may be carried out continuously after the spun yarn is taken up without being taken up, and may be taken up at a high speed of 4000 m / min or more and the desired fiber performance can be obtained at once without being drawn substantially. You may take the method of obtaining.

As the direct spinning and drawing method, for example, the spun yarn is drawn at 1000 to 5000 m / min, and subsequently 300
A method of stretching and heat setting at 0 to 6000 m / min can be mentioned.

The cross-sectional shape of the synthetic fiber of the present invention is not limited to a round shape, but may be a modified cross-section such as a triangular shape, a flat shape, or a multileaf type. Further, the filamentous form of the synthetic fiber may be either filament or staple, and is appropriately selected depending on the application. The fabric form can be appropriately selected according to the purpose, such as woven fabric, knitted fabric, and non-woven fabric.

[0030]

EXAMPLES The present invention will now be described in more detail by way of examples. Each characteristic value in the examples was determined by the following method.

A. Intrinsic viscosity of polyester [η] Dissolve the sample polymer in orthochlorophenol and
The relative viscosity ηr at a plurality of points was determined using an Ostwald viscometer at 5 ° C., and the relative viscosity ηr was determined as an infinite dilution outer layer.

B. Moisture absorption rate of particles and fibers containing the same In the case of particles, 1 g of particles is used, and in the case of fibers, 1 g of yarn or cloth is used. It was determined by the following formula from the weight change with the weight after standing for 24 hours in a thermo-hygrostat (PR-2G manufactured by Tabai) under an atmosphere of 65% RH). Moisture absorption rate (%) = (weight after moisture absorption-weight at absolute dryness) /
Dry weight x 100 C.I. Average particle size of particles The average particle size of particles is the particle size analyzer manufactured by HORIBA (LB-
500).

D. Specific surface area of particles, pore volume Measured at a temperature of 77 K by a nitrogen adsorption method. The specific surface area was analyzed by the BET method and the pore volume was analyzed by the DH method.

E. Quantitative determination of silanol groups on the surface The finely divided silica was dried at a pressure of 0.1 kPa or less and a temperature of 120 ° C., and then reacted with lithium aluminum hydride in dioxane to measure the amount of hydrogen.

F. The aspect ratio transmission electron microscope was used to measure the maximum major axis and the minimum minor axis of the particles, and the ratio of the major axis to the minor axis was determined as an average value of 100 particles.

G. Chip rate of polyester chips Based on the amount of polymer theoretically calculated from the amount of raw material charged when producing polyester, 70% or more of that amount can be discharged, and ◯, 50% or more and less than 70% Those that could be discharged were evaluated as ◯, those that could be discharged at 30% or more and less than 50% were evaluated as Δ, and those that were less than 30% were evaluated as x.

H. The particle dispersible polyester chip in polyester was melted on a cover glass and observed with an optical microscope (300 times) to determine the number of agglomerated particles per visual field.

No agglomerated particles ○ 20 or less agglomerated particles Δ 21 or more agglomerated particles × I. Strength and elongation Using a Tensilon tensile tester manufactured by Toyo Baldwin Co., Ltd., a value was obtained from a stress-strain curve under the conditions of a test length of 20 cm and a pulling speed of 10 cm / min.

Example 1 As polyester, 100 parts by weight of dimethyl terephthalic acid, 70 parts by weight of ethylene glycol and 0.06 part by weight of calcium acetate were added, and the ester exchange reaction was carried out at 140 to 230 ° C. while distilling methanol. Ethylene glycol solution of trimethyl phosphate 0.04 parts by weight, SiO2 as silica-based inorganic particles is 95% or more, average particle diameter 1.5 μm, pore volume 1.3 ml / g, specific surface area 71
0 m ² / g, 7.5 parts by weight of wet silica particles having 3 silanol groups / nm ^2, 67.5 parts by weight of ethylene glycol, aluminum hydroxide particles having an average particle diameter of 15 nm, aspect ratio of 10, nitric acid as a stabilizer The sol containing (alumina sol-520 20% aqueous solution manufactured by Nissan Chemical Industries, Ltd.) was used as particles to obtain a polyester of 0.
Slurry added to 5 parts by weight, and 0.03 parts by weight of antimony trioxide were added, and the pressure was reduced to 0.1 kPa.
Polymerization was carried out under the condition that the temperature was raised to 90 ° C. to obtain polyester. The properties of this polyester are shown in Table 2.

The polyester was melted and discharged from a concentric spinneret to obtain an undrawn yarn, which was then drawn and heat-treated to obtain a polyester fiber of 83 decitex 24 filaments. This fiber was cylindrically knitted, then scoured and dyed, and the moisture absorption was measured to be 1.5%, and the strength and elongation characteristics were also good.

Examples 2-8, Comparative Examples 1-3 Silica-based inorganic particles in polyester in Example 1,
Polyester fibers were obtained by the same method except that the aluminum hydroxide particles were shown in Table 1. In Comparative Example 1, since only silica-based inorganic particles were used, it was not possible to obtain a material having satisfactory chipping ratio and particle dispersibility. In Comparative Example 2, silica sol particles were used instead of aluminum hydroxide-based particles, and thus polyester synthesis was performed. The viscosity increased drastically and the chip formation rate was low. In Comparative Example 3, the thickening due to silica particles during the polymerization was severe, and the degree of polymerization of the base polyester did not increase, so the chipping ratio was lowered and the particle dispersibility was also poor.

[0042]

[Table 1]

[0043]

[Table 2] Example 9 As polyester, 93.5 parts by weight of dimethyl terephthalic acid, 63 parts by weight of ethylene glycol, 7.5 parts by weight of dimethyl 5-sodium sulfoisophthalate, 0.06 parts by weight of calcium acetate are added, and methanol is added at 140 to 230 ° C. After carrying out the transesterification reaction while distilling out, an ethylene glycol solution containing 0.04 part by weight of trimethyl phosphate,
The silica-based inorganic particle-containing slurry and the aluminum hydroxide-based particle-containing slurry described in Example 1 and 0.03 part by weight of antimony trioxide were added, and the pressure was reduced to 285 ° C. at 0.1 kPa.
Polymerization was carried out under the condition that the temperature was raised to 1, to obtain polyester. The content of silica-based inorganic particles in this polyester is 7% by weight, and the copolymerization amount of 5-sodium sulfoisophthalic acid is 5%.
mol%, intrinsic viscosity 0.55, good chipping rate (evaluation:
◯), and particle dispersibility was good (evaluation: ◯).

The polyester was melted, discharged from a concentric die to obtain an undrawn yarn, and then drawn and heat-treated to obtain a polyester fiber of 83 decitex 24 filaments. This fiber was knitted, then scoured and dyed, and the moisture absorption rate was measured to be 2.3%, and the strength / elongation characteristics were good at a strength of 2.3CN / dtex and an elongation of 33.2%. .

Example 10 As polyester, 100 parts by weight of dimethyl terephthalic acid, 70 parts by weight of ethylene glycol and 0.06 part by weight of calcium acetate were added, and the ester exchange reaction was carried out at 140 to 230 ° C. while distilling methanol. Molecular weight 20
100 parts polyethylene glycol 12 parts by weight, trimethyl phosphate 0.05 parts by weight ethylene glycol solution, silica-based inorganic particle-containing slurry and aluminum hydroxide-based particle-containing slurry described in Example 1, and antimony trioxide 0.
03 parts by weight was added, and polymerization was performed under the condition of heating to 290 ° C. under reduced pressure of 0.1 kPa to obtain polyester. The content of silica-based inorganic particles in this polyester was 7% by weight, the copolymerization amount of polyethylene glycol was 10% by weight, the intrinsic viscosity was 0.651, the chipping rate was good (evaluation: ◯), and the particle dispersibility was good ( The evaluation was ○).

The polyester was melted and discharged from a concentric spinneret to obtain an unstretched yarn, which was then stretched and heat-treated to obtain a polyester fiber of 83 decitex 24 filaments. The fiber was knitted, scoured and dyed, and the moisture absorption was measured to be 2.2%. The strength and elongation characteristics were 3.0 CN / dtex and the elongation was 38.9%.

Example 11 As polyester, 94 parts by weight of dimethyl terephthalic acid, 74 parts by weight of 1,3-propanediol and 0.1 part by weight of tetrabutyl titanate were added, and the ester exchange reaction was carried out at 140 to 230 ° C. while distilling methanol. After doing
A 1,3-propanediol solution containing 0.02 parts by weight of trimethyl phosphate, a slurry containing silica-based inorganic particles described in Example 1, and a slurry containing aluminum hydroxide-based particles containing ethylene glycol changed to 1,3-propanediol. In addition, polymerization was carried out under a constant pressure of 250 ° C. under a reduced pressure of 0.1 kPa to obtain a polyester. The content of silica-based inorganic particles in this polyester was 7% by weight, and the intrinsic viscosity was 0.
623, the chip formation rate was good (evaluation: ◯), and the particle dispersibility was good (evaluation: ◯).

The polyester was melted and discharged from a concentric circular die to obtain an undrawn yarn, which was then drawn and heat-treated to obtain a polyester fiber having 83 decitex 24 filaments. This fiber was knitted, then scoured and dyed, and the moisture absorption was measured to be 1.5%, and the strength and elongation characteristics were good, with a strength of 2.9 CN / dtex and an elongation of 37.2%.

Example 12 As polyester, 93.5 parts by weight of dimethyl terephthalic acid, 63 parts by weight of ethylene glycol, 7.5 parts by weight of dimethyl 5-sodium sulfoisophthalate, and 0.06 parts by weight of calcium acetate were added, and 140 to 230 parts were added. After carrying out the transesterification reaction while distilling methanol at ℃, 5.3 parts by weight of polyethylene glycol having a molecular weight of 4000, an ethylene glycol solution of 0.04 parts by weight of trimethyl phosphate, a slurry containing silica-based inorganic particles described in Example 1 And a slurry containing aluminum hydroxide-based particles, and 0.03 part by weight of antimony trioxide are added, and the pressure is reduced to 0.1 kPa.
Polymerization was carried out under the condition that the temperature was raised to 5 ° C. to obtain polyester. The content of silica-based inorganic particles in this polyester is 7
% By weight, the copolymerization amount of 5-sodium sulfoisophthalic acid is 5 mol%, the copolymerization amount of polyethylene glycol is 5% by weight, the intrinsic viscosity is 0.58, and the chipping rate is good (evaluation: ○
◯), and particle dispersibility was good (evaluation: ◯).

The polyester was melted and discharged from a concentric spinneret to obtain an unstretched yarn, which was then stretched and heat treated to obtain a polyester fiber of 83 decitex 24 filaments. The fiber was knitted, scoured and dyed, and the moisture absorption rate was measured to be 2.8%, and the strength / elongation property was also good at a strength of 2.6CN / dtex and an elongation of 35.1%. .

[0051]

Industrial Applicability The synthetic fiber obtained by the present invention not only has sufficient hygroscopicity to obtain wearing comfort, but also has excellent productivity. It also has a dry-touch texture and high dyeing fastness and light resistance. The synthetic fiber of the present invention is suitable for underwear, shirts, blouses, inner garments, sportswear, slacks, outerwear, linings, curtains, wallpapers, and even bedding such as sheets, futon covers, and cotton stuff, and is extremely suitable. It is highly practical.

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Claims (7)

[Claims] 1. Silica-based inorganic particles having a pore volume of 0.5 ml / g or more and a specific surface area of 500 m ² / g or more and 1 to 20% by weight, and aluminum hydroxide-based particles having an average particle size of 1 to 100 nm. Hygroscopic polyester fiber containing 0.05 to 5% by weight. 2. The hygroscopic polyester fiber according to claim 1, wherein the silica-based inorganic particles are silica particles obtained by a wet method. 3. Aluminium hydroxide-based particles having an aspect ratio of 2 to
20. The hygroscopic polyester fiber according to claim 1, which is 20. 4. The hygroscopic polyester fiber according to claim 1, wherein the moisture absorption rate of the polyester fiber is 1.0% or more. 5. The hygroscopic polyester fiber according to claim 1, wherein 80% by mole or more of the polyester is a alkylene terephthalate repeating unit. 6. A polyester having a total acid content of 0.5 to 0.5.
The hygroscopic polyester fiber according to any one of claims 1 to 5, wherein 20 mol% of a metal salt of sulfoisophthalic acid is copolymerized. 7. A polyester having a molecular weight of 600 to 200.
0.5 to 15 of polyoxyalkylene glycol of 00
The polyester fiber excellent in hygroscopicity according to any one of claims 1 to 6, wherein the polyester fiber is copolymerized by weight%.