JP2002363824A - Polyester fiber having excellent hygroscopicity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester fiber having an excellent productivity and high hygroscopicity, and capable of providing a woven or knitted product or the like usable as a comfortable material such as an underwear, a sport wear and a lining. SOLUTION: This polyester fiber having the excellent hygroscopicity and productivity contains both of silica-based inorganic particles and inorganic particles having surface potentials opposing to those of the silica-based particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyester fiber having excellent hygroscopicity and particle dispersibility. More specifically, since synthetic polyester fibers excellent in moisture absorption and particle dispersibility can be uniformly and stably produced, there is little yarn breakage during spinning due to coarse particles, and synthetic fibers not only have excellent productivity but also have comfortable wearing. The present invention relates to a polyester fiber having use and antistatic properties.

[0002]

2. Description of the Related Art Polyesters such as polyethylene terephthalate have been widely used for applications such as fibers, films and compositions because of their excellent strength, heat stability and chemical resistance. However, since polyethylene terephthalate is inherently hydrophobic, it has extremely poor moisture absorption and desorption properties, and when used as clothing, it may cause "moody" 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 disadvantage, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-8270, copolymerization of a diol having an oxyalkylene glycol in the side chain,
Japanese Patent Application Laid-Open No. 2-26985 proposes a method of copolymerizing a compound having hygroscopicity with a polyester, such as copolymerization of a sulfonic acid metal salt-containing dicarboxylic acid. However, copolymerization of the moisture-absorbing component results in the modification of the entire polymer, resulting in a serious problem that the weather resistance is reduced and the original advantage of polyester, that is, excellent mechanical properties, is lost.

[0004] As disclosed in Japanese Patent Application Laid-Open No. 52-74020, acrylic acid or methacrylic acid is graft-polymerized on polyester fibers, and their carboxyl groups are substituted with alkali metals to impart hygroscopicity. There are known ways to do this. However, it has not been put to practical use because of problems such as a decrease in light resistance, a problem of slimming due to a moisture absorbing portion adhering to the composition or the fiber surface layer, and a decrease in strength over time.

In order to solve these problems, in fiber applications, a core-sheath type conjugate fiber in which a hygroscopic resin having high hygroscopicity is used as a core and covered with a polyester sheath is disclosed in JP-A-2-99.
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. Hei 9-32871, and the like have been proposed. However, in the case of these core-sheath type conjugate fibers, the hygroscopic resin in the core part swells greatly including water during hot water treatment such as scouring or dyeing, so that cracks (sheath cracks) occur on the fiber surface and the hygroscopic property There were drawbacks in that the quality of the fabric deteriorated, such as outflow of the resin and remarkable deterioration of the color fastness. For the purpose of suppressing this sheath cracking, a method of providing a hollow portion adjacent to a hygroscopic core component in advance from the melt spinning stage is disclosed in
Japanese Patent Application Laid-Open No. 9-111579 and Japanese Patent Application Laid-Open No. 52-55721 propose a hollow portion even if the fiber is twisted or false-twisted even if the fiber is formed into a shape having a hollow portion. There is a disadvantage that the sheath is cracked due to swelling of the moisture-absorbing polymer as in the case described above by the subsequent hot water treatment.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polyester fiber which overcomes the above-mentioned problems of the prior art and maintains excellent properties of polyester while having high moisture absorption properties and excellent particle dispersibility. To provide.

[0007]

Means for Solving the Problems The above-mentioned problem is caused by the fact that 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, The problem can be solved by a polyester fiber having excellent hygroscopicity and containing inorganic particles having an opposite potential on the particle surface.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 , Examples thereof include white carbon, silica sol, and silica gel, and are preferably silica having a SiO ₂ content of 95% or more, and more preferably wet silica.

The silica-based inorganic particles used in the present invention preferably have a specific surface area of 500 m ² / g or more. When the 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 are obtained.

The average particle size of the silica-based inorganic particles used in the present invention is 0.0
1-10 μm is preferred. 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 ^TwoMore silano
Preferably, the hydroxyl group is present on the particle surface.

[0014] The moisture absorption of the silica-based inorganic particles in a standard state is determined by the following formula.
The higher the value, the more preferable, but it is preferably at least 20%, more preferably at least 25%.

It is necessary that the silica-based inorganic particles of the present invention contain inorganic particles having a surface potential opposite to that of the particles. By using both of them, not only can moisture absorption performance be maintained, but also polyester fibers having excellent particle dispersibility can be obtained. The surface potential can be measured as a ζ-potential, and is a value measured by a usual electrophoresis method by adding inorganic particles to pure water to form a diluted slurry. The concentration of the inorganic particles is ζ
When dispersing the inorganic particles in pure water, which is not directly related to the electric potential, the inorganic particles are usually 1 to 100 p.
Preferably, the concentration is pm.

The inorganic particles having a surface potential opposite to each other are not particularly limited, but if the 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 have a negative potential, they are positively charged. Is used. ζ-
Examples of the inorganic particles having a negative potential include silicon oxide and titanium oxide, but silicon oxide is preferable.
Examples of the inorganic particles having a positive ζ-potential include aluminum oxide, magnesium oxide, calcium oxide, zirconium oxide and the like, and composite oxides thereof, and at least one of calcium carbonate, barium sulfate, calcium phosphate, and calcium fucca. it can. Of these inorganic particles, aluminum oxide, barium sulfate, zirconium oxide, and calcium fucker are preferred because they can suppress an increase in melt viscosity during polyester synthesis and can improve production stability. Particularly preferred are aluminum oxide and barium sulfate.

In the polyester of the present invention, from the viewpoint of excellent strength, 80 mol% or more of the polyester is composed of alkylene terephthalate repeating units. For example, polyethylene terephthalate, poly-1,3-propylene terephthalate, polyethylene-2, 6-naphthalenedicarboxylate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, etc., among which polyethylene terephthalate, poly-1,3-
Propylene terephthalate is preferred.

The polyester containing ethylene terephthalate as a main repeating unit may have another third component copolymerized within a range not to impair the object of the present invention. For example, compounds that can be used in place of terephthalic acid include isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, and the like, aromatic, aliphatic, Alicyclic dicarboxylic acids and their derivatives can be mentioned. Diol compounds that can be used in place of ethylene glycol include propylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, polyalkylene glycol, bisphenol A, bisphenol S
And aromatic, aliphatic, and alicyclic diol compounds. These polymers may contain a matting agent, an antistatic agent, a deodorant, a fine pore forming agent, and the like, if necessary.

For the purpose of improving the hygroscopicity of the polymer itself, it is preferable to copolymerize the metal sulfoisophthalate in an amount of 0.5 to 20 mol%. The copolymerization ratio is more preferably 1 to 10 mol% from the viewpoint of sufficient moisture absorption / release properties and strength.

Further, for the same purpose, the molecular weight is from 600 to 20.
000 polyoxyalkylene glycol from 0.5 to 1
It is preferable to copolymerize 5% by weight, more preferably 2% by weight.
-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, and polypropylene oxide / polytetraethylene glycol. Methylene oxide block copolymers and the like are mentioned, and polyethylene glycol is preferable.

The amount of the silica-based inorganic particles used in the present invention is 1 to 20% by weight. If the amount is less than 1% by weight, the moisture absorption / release properties of the polyester composition become insufficient,
On the other hand, if it exceeds 20% by weight, the melt viscosity of the composition becomes extremely high, so that molding becomes difficult. A more preferred addition amount is 5 to 15% by weight. The amount of the inorganic particles having a surface potential opposite to that of the particles is preferably from 0.1 to 20% by weight based on the particles in view of the effect of suppressing the increase in melt viscosity of the polyester composition and the heat resistance. A more preferred addition amount is 0.5 to 10% by weight.

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

In the present invention, the method of incorporating the inorganic particles and the inorganic particles having a surface potential opposite to each other into the polyester may be any of the following methods: esterification or transesterification of polyester; polycondensation reaction; In this step, the inorganic particles mixed in advance may be added to the synthesis step, or they may be individually added and mixed in the reaction vessel. Also, both may be coexistent at the stage of dispersing and pulverizing the inorganic particles in the solvent.

The fiber using the polyester of the present invention can be produced by a conventionally known method. The production method is described below. The polyester containing the inorganic particles is melted, guided to a spinning pack, and spun out from a die discharge hole.

After taking out the spun filament yarn at a predetermined speed, it is once wound up in a package, and the obtained undrawn yarn is drawn by a usual drawing machine. Also, this drawing may be performed continuously without winding after winding the spun yarn and winding may be performed. At a high speed of 4000 m / min or more, the drawing may be performed at a stretch without substantially drawing the desired fiber performance. You may take the method of obtaining.

As a direct spin drawing method, for example, a spun yarn is taken at 1000 to 5000 m / min,
A method of stretching and heat-setting at 0 to 6000 m / min.

The cross-sectional shape of the synthetic fiber of the present invention is not limited to a circle, but may be a triangular, flat, multi-leaf or other irregular cross-section. The thread 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 depending on the purpose, such as a woven fabric, a knitted fabric, or a nonwoven fabric.

[0028]

The present invention will be described in more detail with reference to the following examples. In addition, each characteristic value in an Example was calculated | required by the following method.

A. Intrinsic viscosity of the polyester [η] An orthochlorophenol solution was determined at 25 ° C.

B. Moisture Absorption of Particles and Fibers Containing the Same The moisture absorption was measured using 1 g of particles in the case of particles and 1 to 3 g of fibers or fibers in the case of fibers. (65% RH) in an atmosphere of constant temperature and humidity (Tavai PR-2G) for 24 hours. Moisture absorption (%) = (weight after moisture absorption-weight when absolutely dry) /
Weight when absolutely dry × 100 C.I. Average particle size of the particles The average particle size of the particles is determined by a particle size analyzer manufactured by HORIBA (LA-
700).

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

E. Determination of Silanol Groups on Surface Fine powder 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. Surface potential of the inorganic particles (ζ-potential) After the inorganic particles were uniformly dispersed in pure water, the measurement was performed using a LASERZEE ^™ Model 501 manufactured by PENKEM.

G. Chip rate of polyester chips The amount of chips obtained after the completion of the polymerization reaction was measured and determined by the following equation. 80% or more was regarded as a pass. (Chip amount / theoretical polymer amount) × 100 Particle Dispersibility in Polyester A polyester chip was melted on a cover glass, observed with an optical microscope (× 300), and determined by the number of aggregated particles per visual field.

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

EXAMPLE 1 95% or more of SiO ₂ as silica-based inorganic particles, average particle size of 2.8 μm, pore volume of 1.10 ml / g, specific surface area of 610 m ² / g, and 3 silanol groups / nm ² 6.4 parts by weight of wet silica particles (ζ-potential is -18), 58 parts by weight of ethylene glycol, and 5 parts by weight of aluminum oxide having a ζ-potential of +58 as inorganic particles having an opposite surface potential with respect to the silica particles. In addition, an ethylene glycol slurry was added.

As a polyester, 194 parts of dimethyl terephthalic acid, 124 parts of ethylene glycol and 0.07 part of calcium acetate were added, and a transesterification reaction was carried out at 140 to 230 ° C. while distilling off methanol. Of ethylene glycol solution, the above-mentioned ethylene glycol slurry containing particles, and 0.03 part of antimony trioxide, and 290 under reduced pressure of 0.1 kPa.
Polymerization was carried out under the condition of elevating the temperature to ° C to obtain a polyester.
The properties of this polyester are shown in Table 2.

The polyester was melted and discharged from a concentric die to obtain an undrawn yarn, followed by drawing and heat treatment to obtain a polyester fiber of 83 dtex 24 filaments. After knitting this fiber, it was scoured and dyed, and the moisture absorption was measured to be 1.3%. The strength and elongation characteristics were also good.

Examples 2 to 8 and Comparative Example 1 In Example 1, except that the type and addition amount of the silica-based inorganic particles in the polyester, and the type and addition amount of the inorganic particles having a potential opposite to that of the particles and the particle surface were changed. Obtained a polyester fiber by the same method. In Comparative Example 1, since the surface potential of the silica-based inorganic particles was the same as that of the silica-based inorganic particles, the viscosity increased sharply at the time of polyester synthesis, the chipping rate and the particle dispersibility were poor, and the quality was poor.

[0040]

[Table 1]

[0041]

[Table 2] Example 9 As polyester, 194 parts of dimethyl terephthalic acid was used.
135 parts of ethylene glycol, 26.6 parts of dimethyl 5-sodium sulfoisophthalate, 0.0% of calcium acetate
After adding 6 parts and performing transesterification while distilling methanol at 140 to 230 ° C., trimethyl phosphate was added.
To the mixture were added 04 parts of an ethylene glycol solution, the particle-containing ethylene glycol slurry described in Example 1, and 0.03 part of antimony trioxide.
Polymerization was carried out under the condition where the temperature was raised to obtain a polyester. The content of silica particles in this polyester was 6% by weight,
The copolymerization amount of sodium sulfoisophthalic acid was 5 mol%.

The polyester was melted and discharged from a concentric die to obtain an undrawn yarn, which was then drawn and heat-treated to obtain a polyester fiber of 83 dtex 24 filaments. This fiber was knitted, scoured and dyed, and the moisture absorption was measured. The moisture absorption was 2.5%, and the strength and elongation characteristics were good, with a strength of 3.3 CN / dtex and an elongation of 39.5%. .

Example 10 As a polyester, 194 parts of dimethyl terephthalic acid was used.
124 parts of ethylene glycol, calcium acetate 0.07
After performing a transesterification reaction while distilling off methanol at 140 to 230 ° C., 20 parts of polyethylene glycol having a molecular weight of 2,000, an ethylene glycol solution of 0.05 parts of trimethyl phosphate, and the ethylene containing particles described in Example 1 were added. A glycol slurry and 0.02 part of antimony trioxide were added, and polymerization was carried out under the condition of elevating the temperature to 290 ° C. under a reduced pressure of 0.1 kPa to obtain a polyester. The content of silica particles in this polyester was 6% by weight, and the copolymerization amount of polyethylene glycol was 10% by weight.

The polyester was melted and discharged from a concentric die to obtain an undrawn yarn, followed by drawing and heat treatment to obtain a polyester fiber of 83 dtex 24 filaments. After knitting the fiber, it was scoured and dyed, and the moisture absorption was measured to be 2.4%. The strength and elongation characteristics were good with a strength of 3.4 CN / dtex and an elongation of 37.1%.

Example 11 Silica-based inorganic particles containing 95% or more of SiO ₂ , an average particle size of 2.8 μm, a pore volume of 1.10 ml / g, a specific surface area of 610 m ² / g, and three silanol groups / nm ² 1,3 to 6.4 parts by weight of wet silica particles (ζ-potential is −18)
58 parts by weight of propanediol and 5 parts by weight of silica particles of aluminum oxide having a ζ-potential of +58 were added as inorganic particles having a potential on the particle surface opposite to each other to obtain a 1,3-propanediol slurry.

As a polyester, 194 parts of dimethyl terephthalic acid, 152 parts of 1,3-propanediol, and 0.1 part of tetrabutyl titanate were added.
Then, a transesterification reaction was performed while distilling off methanol, and a 1,3-propanediol solution containing 0.02 parts of trimethyl phosphate and the above-mentioned 1,3-propanediol slurry containing particles were added thereto. Polymerization was carried out at a constant temperature of 250 ° C. to obtain a polyester. The properties of this polyester are shown in Table 2.

The polyester was melted and discharged from a concentric die to obtain an undrawn yarn, followed by drawing and heat treatment to obtain a polyester fiber of 83 dtex 24 filaments. After knitting the fiber, it was scoured and dyed, and the moisture absorption was measured. The measured value was 1.4%, and the strength and elongation characteristics were good with a strength of 3.0 CN / dtex and an elongation of 35.1%.

[0048]

The synthetic fiber obtained according to the present invention has not only a sufficient hygroscopic property for obtaining comfortable wearing, but also excellent productivity. In addition, it has a dry touch texture, high color fastness and light fastness. The synthetic fibers of the present invention are suitable for underwear, shirts, blouses, middle garments, sportswear, slacks, outer garments, lining, curtains, wallpapers, and even sheets, futon covers, and stuffed cotton, It is highly practical.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 67/00 C08L 67/00 D01F 6/84 305 D01F 6/84 305A 305B 6/86 301 6/86 301D F-term (reference) 4J002 CF06 CF10 CF14 DJ01 FB07 GK01 4J029 AA03 AB04 AC02 AD01 AE02 BA03 BF25 CB05 CB06 CH02 DB01 HA01 HB01 HB02 JA29 4L035 AA05 BB31 EE05 EE07 EE20 FF04 FF10 HH01 KK07 KK05 KK10 KK05 JJ05 KK05 KK10

Claims (7)

[Claims] 1. A silica-based inorganic particle 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 the silica-based inorganic particle has an opposite potential on the particle surface. Polyester fiber with excellent hygroscopicity containing inorganic particles. 2. The polyester fiber according to claim 1, wherein the silica-based inorganic particles are silica particles obtained by a wet method. 3. The silica-based inorganic particle according to claim 1, wherein the inorganic particle whose surface potential is opposite to the inorganic particle is selected from at least one of aluminum oxide, calcium fluoride, zirconium oxide, and barium sulfate. Polyester fiber. 4. The polyester fiber excellent in hygroscopicity according to claim 1, wherein the polyester fiber has a moisture absorption of 1.0% or more. 5. The polyester fiber excellent in hygroscopicity according to claim 1, wherein at least 80 mol% of the polyester is a polyester comprising an alkylene terephthalate repeating unit. 6. The polyester according to claim 1, wherein the total amount of the acid is 0.5 to
The polyester fiber excellent in hygroscopicity according to any one of claims 1 to 5, wherein 20 mol% of a metal sulfoisophthalate component is copolymerized. 7. The polyester has a molecular weight of from 600 to 200.
Polyoxyalkylene glycol of 0.5 to 15
The polyester fiber excellent in hygroscopicity according to any one of claims 1 to 6, which has been copolymerized by weight%.