JP2002201343A - Polyester composition and fiber comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester composition comprising a large amount of silica inorganic particles having hygroscopicity and a polyester fiber having excellent weather resistance, excellent mechanical characteristics and excellent hygroscopicity which is sufficiently high to obtain comfortableness to wear and suitably usable as a woven or a knitted fabric, etc., for a comfortable material such as an underwear, a sportswear or a lining fabric. SOLUTION: This polyester composition comprises 1-20 wt.% of silica inorganic particles having 0.01-10 μm average particle diameter and antimony element in an amount within the range of <=200 ppm. The fiber comprises the polyester composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition containing a large amount of silica-based inorganic particles and a fiber comprising the same. More specifically, the present invention relates to a polyester composition containing a large amount of silica-based inorganic particles having hygroscopicity and a polyester fiber excellent in weather resistance, mechanical properties, and hygroscopicity. The polyester fiber has high hygroscopicity and can be suitably used as a comfortable material such as underwear, sportswear, and lining as a woven or knitted fabric.

[0002]

2. Description of the Related Art Polyesters represented by polyethylene terephthalate have excellent physical and chemical properties and are widely used as fibers, films and other molded products. However, because polyethylene terephthalate is inherently hydrophobic, it has very poor moisture absorption and desorption properties,
When used as a garment, it is not a preferable material in terms of wearing comfort, for example, it gives rise to "uncomfortable feeling" at high humidity and generates static electricity at low humidity in winter.
Also, when used as a resin or a film, it may be charged due to low hygroscopicity, which may cause a problem.

In order to solve these problems, there has been proposed a method of copolymerizing or adding a compound having a moisture absorbing property to polyester. For example, JP-A-48-8270 discloses a method of copolymerizing a diol having an oxyalkylene glycol in a side chain, and JP-A-2-26985 discloses a method of copolymerizing a dicarboxylic acid containing a metal sulfonic acid salt. Have been. However, such a method of copolymerizing a moisture absorbing component has a problem that strength and weather resistance are reduced.

[0004] In addition to the above-mentioned method of modifying polyester, a method of attaching a hygroscopic compound to polyester fibers has been proposed. For example, Japanese Patent Publication No. Sho 59-17224 discloses a method in which acrylic acid or methacrylic acid is graft-polymerized onto polyester fibers, and the carboxyl groups thereof are replaced with an alkali metal to improve the hygroscopicity. However, since the hygroscopic compound adheres to the fiber surface, there is a problem that slimming occurs, strength decreases over time, and light resistance decreases.

Further, in order to solve the above 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-2-99612. JP, JP-A-4-361616, JP-A-4-341617, JP-A-9-13
No. 2871 has been proposed. However, in the case of these core-sheath type composite fibers, the hygroscopic resin in the core swells due to the water content during hot water treatment such as scouring or dyeing, so that the fiber surface cracks (sheath crack) and the hygroscopic resin flows out of the fiber. However, there is a problem that the dyeing fastness is not sufficient and the quality of the fabric is deteriorated, and it cannot be said that the technology for imparting moisture absorption to the polyester fiber is at a sufficiently satisfactory level.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a polyester composition and fiber having excellent hygroscopicity while maintaining excellent properties of polyester. Is to provide.

[0007]

Means for Solving the Problems The above-mentioned problem is solved by using silica-based inorganic particles having an average particle diameter of 0.01 to 10 μm in 1 to 20 μm.
The problem can be solved by a polyester composition and a fiber comprising the same in an amount of not more than 200 ppm by weight of an antimony element.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester of the present invention is preferably composed of a dicarboxylic acid component and a glycol component. For example, an esterification or transesterification reaction of a dicarboxylic acid or an ester-forming derivative thereof with a glycol and a subsequent step It is produced by a polycondensation reaction. The type of polyester is not particularly limited as long as it can be formed into a molded product such as fiber. Suitable polyesters that can be molded into molded articles such as fibers include those composed of aromatic dicarboxylic acid as the dicarboxylic acid component and aliphatic glycol or alicyclic glycol as the glycol component, such as polyethylene terephthalate and polyglycol. -1,3-propylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, etc. Among them, polyethylene terephthalate, poly- 1,3-propylene terephthalate is preferred.

Of course, these polyesters may be homopolyesters or copolyesters. In this case, the copolymerization components include aromatic dicarboxylic acids other than the acid components and glycol components constituting the polyesters described above. Examples include acid components such as aliphatic dicarboxylic acids and alicyclic dicarboxylic acids, and glycol components such as aromatic glycols, aliphatic glycols and alicyclic glycols. For example, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, phthalic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid And aliphatic dicarboxylic acids such as sebacic acid, dimer acid, maleic acid and fumaric acid, and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and decalin dicarboxylic acid. The glycol component includes fats such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,10-decanediol. Triglycol,
Examples thereof include alicyclic glycols such as 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A. The above-mentioned acid component and glycol component may be used alone or in combination of two or more. Also, these copolymer components are
It may be a by-product when producing polyester. Further, the amount of the components in the case of copolymerization is not particularly limited, but is preferably 30 mol% or less from the viewpoint of the strength and heat resistance of the obtained fiber.

[0010] The polyester of the present invention contains silica-based inorganic particles.

The silica-based inorganic particles used in the present invention are inorganic particles in which at least 50% of the particles are composed of SiO ₂ .
Specific examples include white carbon, silica sol, silica gel, silica-alumina composite particles obtained by a dry method, a wet method, and the like. Among them, silica-based inorganic particles obtained by a wet method are preferred from the viewpoint of the moisture absorption of fibers obtained from the polyester composition of the present invention. Especially Si
Silica particles obtained by a wet method having an O ₂ content of 95% or more are preferred.

The silica-based inorganic particles of the present invention have an average particle size of 0.01 to 0.01 from the viewpoints of the particle dispersibility in the polyester, the increase in the molecular weight of the obtained polyester, and the stability of the process when forming into fibers. It is 10 μm, preferably 0.1-5 μm, more preferably 0.2-2 μm. When the average particle size is less than 0.01 μm, the particles have poor dispersibility, or during the polycondensation reaction of the polyester production step, the particles are aggregated by the surface activity of the particles, or the melt viscosity of the polymer rapidly increases. , A high molecular weight polymer cannot be obtained. On the other hand, when the average particle size exceeds 10 μm,
A sudden increase in filter pressure may occur during melt molding,
Thread breakage occurs when forming into fibers.

Furthermore, the silica-based inorganic particles of the present invention are obtained
In view of the moisture absorption and desorption properties of the fibers, the pore volume of the particles is 0.5
ml / g or more, pore volume (ml / g) and specific surface area
(M ^Two/ G) preferably satisfies the following equation:
No.

100 ≦ (specific surface area of particles / pore volume of particles) ≦ 1500 More preferably, the pore volume of silica-based inorganic particles is 0.7 ml.
/ G or more, more preferably 1.0 ml / g or more. If the pore volume is out of this range, the silica-based inorganic particles may have poor hygroscopicity, and the resulting fiber may have poor hygroscopicity. A more preferable relationship between the pore volume and the specific surface area is as follows: 200 ≦ (specific surface area of particles / pore volume of particles) ≦ 100
0, more preferably 300 ≦ (specific surface area of particles / pore volume of particles) ≦ 800. If the relationship between the pore volume of the particles and the specific surface area is out of the range, the particles may be poor in hygroscopicity, and the fiber obtained from the polyester composition containing the particles may be poor in hygroscopicity.

Further, in the silica-based inorganic particles used in the present invention, from the viewpoint of hygroscopicity, it is preferable that at least 2 / nm ² silanol groups exist on the particle surface. If the number of silanol groups on the surface is less than this, satisfactory hygroscopicity may be poor.

The silica-based inorganic particles of the present invention preferably have a high hygroscopicity in order to enhance the hygroscopicity of the obtained fiber, and preferably have a hygroscopicity of 7% or more in a standard state. More preferably 10% or more, further preferably 20% or more,
It is particularly preferably at least 30%. If the moisture absorption of the silica-based inorganic particles is less than 7%, the resulting fiber may have poor moisture absorption / desorption properties.

The content of the silica-based inorganic particles of the present invention in the polyester is from 1 to 20% by weight from the viewpoint of increasing the molecular weight of the obtained polyester, dispersing the particles in the polyester, and absorbing and releasing the fibers, and the strength. %. Preferably 2
It is 17% by weight, more preferably 3 to 15% by weight, still more preferably 5 to 15% by weight. When the content is less than 1% by weight, the obtained fiber is inferior in moisture absorption / release properties. Meanwhile, 2
If the content exceeds 0% by weight, the melt viscosity of the particle-containing polyester composition becomes extremely high, so that high molecular weight polyester cannot be obtained, and the mechanical properties such as fiber strength are poor.

The method of incorporating the silica-based inorganic particles into the polyester of the present invention includes, for example, (1) directly mixing the silica-based inorganic particles and the polyester with a blender, a mixer, or the like; Melt kneading using a screw extruder, (2) silica-based inorganic particles and polyester are mixed directly or beforehand in a blender, mixer, or the like, and then mixed with a normal vent-type single screw;
Examples thereof include a method of melt-kneading using a twin-screw extruder, and a method of adding (3) silica-based inorganic particles in a polyester production reaction step. Above all, it is preferable to incorporate the silica-based inorganic particles by the method (2) or (3) from the viewpoint of the particle dispersibility of the silica-based inorganic particles and the quality stability of the obtained fiber.

The polyester composition containing the silica-based inorganic particles of the present invention has an antimony element content of 200 ppm or less from the viewpoint of increasing the molecular weight of the polyester or reducing the melt viscosity of the polyester composition. By setting the antimony element to 200 ppm or less, in the polycondensation reaction stage of the polyester production process, it is possible to suppress agglomeration of the particles caused by the surface activity of the particles and a sharp rise in the melt viscosity of the polymer, and excellent particle dispersibility, and A high molecular weight polyester is obtained. In addition, a sharp increase in filter pressure during melt molding is suppressed, and yarn breakage is small when molding into fibers. The preferred content of the antimony element is 0.1 to 1
It is 50 ppm, more preferably 5 to 100 ppm. More preferably, it is 10 to 50 ppm. When the content of the antimony element exceeds 200 ppm, the particle dispersibility becomes poor, or a sharp increase in melt viscosity occurs in the polyester production process, so that a high molecular weight polyester cannot be obtained. The strength also decreases.

As a method for incorporating an antimony element into the polyester composition of the present invention, for example, a compound containing an antimony element, specifically, antimony trioxide, antimony pentoxide, antimony acetate, or the like is introduced into a reaction system at the time of polyester production. A method of adding and blending as a polycondensation reaction catalyst and additive can be used.

In producing the polyester of the present invention, conventionally known reaction catalysts can be used in addition to the antimony element-containing compound. For example, metal compounds such as alkali metals, alkaline earth metals, zinc, manganese, and cobalt can be used as esterification or transesterification reaction catalysts, and titanium and germanium compounds can be used as polycondensation reaction catalysts.

The polyester composition of the present invention and a fiber comprising the same may be used as pigments such as titanium oxide and carbon black, a surfactant such as alkylbenzene sulfonate, and a conventionally known antioxidant as long as the object of the present invention is not impaired. , An anti-coloring agent, a light-fast agent, an antistatic agent, and the like.

The fiber comprising the polyester composition of the present invention can be produced by a conventionally known method. For example, 5
A method of melt-spinning at a speed of 00 to 2500 m / min, followed by drawing and heat treatment, and a method of melt-spinning at a speed of 1500 to 5000 m / min and performing drawing and false-twisting at the same time or after drawing and false-twisting A method of melt-spinning at a high speed of 3000 m / min or more and omitting a stretching step depending on the application;
Arbitrary yarn production conditions can be adopted.

The cross-sectional shape of the polyester fiber of the present invention may be not only a round shape but also an irregular cross-section such as triangular, flat, multi-lobed, polygonal, H-shaped or Π-shaped. The thread form of the fiber may be either filament or staple, and is appropriately selected depending on the application.

The polyester fiber of the present invention can be used in the form of a fabric, such as a woven fabric, a knitted fabric, or a non-woven fabric, depending on its use.

The fiber of the present invention obtained by the above method preferably has a moisture absorption under a standard condition of 1.0% or more, more preferably 1.5%, in order to obtain practical wearing comfort.
%, More preferably 2.0% or more.

The polyester fiber of the present invention can be reduced by various methods. For example, plasma processing,
Laser treatment, alkali weight reduction treatment and the like can be given. From the viewpoint of the texture of the obtained fiber and dyeability, the alkali weight reduction method is preferred as the weight reduction method. Examples of the alkali used at this time include compounds such as NaOH, KOH, and LiOH. The treatment for reducing the weight of polyester fiber and the like is performed with the aqueous solution of alkali, and the alkali concentration is 0.5%.
In this case, the alkali weight loss rate is not particularly limited, but the weight loss rate is preferably 50% or less, more preferably 30% or less, in view of the strength of the obtained fiber and the texture. Preferably it is 20% or less.

[0028]

The present invention will be described in more detail with reference to the following examples. The characteristics in the examples were obtained by the following methods.

A. Intrinsic viscosity of polyester composition
[Η] Measured at 25 ° C. using an o-chlorophenol solvent.

B. Antimony element content in polyester composition The intensity of the antimony element content was quantified by X-ray fluorescence measurement in comparison with a calibration curve obtained from a standard substance.

C. Particle dispersibility in polyester composition The particle dispersibility was determined by observing the polyester composition with a transmission electron microscope. ：: No coarse particles due to aggregation of the particles are observed. Δ: Coarse particles due to aggregation of particles are slightly observed. ×: Many coarse particles due to aggregation of particles are observed.

D. Moisture Absorption of Particles and Polyester Fibers In the case of particles, 1 g of particles is used, and in the case of fibers, 1 to 3 g of original yarn or fabric is used.
X 1 hour) and 24 hours in a thermo-hygrostat (Tavai PR-2G) under an atmosphere of standard condition (20 ° C x 65% RH).
From the weight change with the weight after standing for a time, it was determined by the following equation.

E. Moisture absorption (%) = (weight after moisture absorption−weight when absolutely dry) / weight when absolutely dry × 100 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).

F. Specific surface area of particles The specific surface area of the particles was determined by a gas adsorption method (BET method).

G. Pore volume of particles The pore volume of the particles was measured at a temperature of 77 K by a nitrogen adsorption method.

H. Determination of Silanol Groups on Surface Fine powder silica was dried at a pressure of -99 kPa or lower at a temperature of 120 ° C., and then reacted with lithium aluminum hydride in dioxane to measure the amount of hydrogen.

I. Fiber 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 1 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol were mixed with magnesium acetate tetrahydrate in an amount of 0.06.
The transesterification reaction was performed while distilling methanol at 140 to 230 ° C. using parts by weight as a catalyst. After transesterification, 95% of SiO ₂ as silica-based inorganic particles
Silica particles obtained by the above wet method [average particle diameter 2.
9 μm, pore volume 1.26 ml / g (specific surface area of particles /
Pore volume = 580), a standard state of moisture absorption of 21.6%] ethylene glycol slurry having a silica particle content of 10% by weight.
Was added so that Then, antimony trioxide was added to 0.1 g.
01 parts by weight, and then the reaction system was set to -101 kPa
The temperature was raised to 290 ° C. and the melt viscosity was 30 while stirring.
The polycondensation reaction was terminated when the stirring load became equivalent to 00 poise. The polycondensation reaction time at this time was 3 hours and 45 minutes. Table 1 shows the properties of the obtained polyester composition. The antimony element content was 80 ppm, the particle dispersibility was good, and the polyester composition had a limiting viscosity of 0.636 and a high molecular weight.

Further, after the obtained polyester composition was sufficiently dried, it was supplied to a spinning machine, melted by a melter, weighed, discharged from the spin pack, and taken out at a speed of 1350 m / min. The obtained undrawn yarn is 2.8 at 80 ° C.
After stretching twice, heat set with a roller (125 ° C),
A drawn yarn of 83 dtex 24 filaments was obtained. The obtained drawn yarn was knitted in a tube and subjected to an alkali treatment so as to have a weight loss of 10%. Thereafter, the moisture absorption under the standard condition was measured. Table 2 shows the obtained fiber property results. The moisture absorption was 2.0%, and both strength and elongation were good.

Comparative Example 1 A polyester composition and fibers were obtained in the same manner as in Example 1 except that the amount of antimony trioxide was changed. The properties of the obtained polyester composition and fibers are shown in Tables 1 and 2. The polycondensation reaction when producing the polyester composition was rapid, and the polycondensation reaction was completed in 2 hours and 15 minutes. The amount of the antimony element in the obtained polyester was 320 ppm, coarse particles were confirmed, and the intrinsic viscosity was as low as 0.504. Further, when the polyester composition was melt-spun, yarn breakage frequently occurred, and the moisture absorption rate and fiber properties were poor.

Examples 2 to 6, Comparative Example 2 The average particle diameter, pore volume, specific surface area,
A polyester composition and fibers were obtained in the same manner as in Example 1, except that the amount added to the polyester and the amount of antimony trioxide were changed. The properties of the obtained polyester composition and fibers are shown in Tables 1 and 2. Example 2
No. 6 to No. 6 are within the range of the present invention, and are high molecular weight polyester compositions having good particle dispersibility, and have good fiber strength, elongation and good moisture absorption. In Comparative Example 2, the content of the silica-based inorganic particles was out of the range of the present invention, and the polycondensation reaction when producing the polyester composition was extremely rapid, and the polycondensation reaction was completed in 1 hour and 10 minutes. Many coarse particles were observed in the obtained polyester composition, and the intrinsic viscosity was as low as 0.452. Furthermore, during the melt spinning of the polyester composition, the pressure was sharply increased, and the yarn was frequently broken, and the fiber could not be formed.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

As described above, the present invention relates to a polyester composition containing a large amount of silica-based inorganic particles having hygroscopicity, and comprising a polyester excellent in weather resistance, mechanical properties and hygroscopicity. Fiber can be obtained. Further, the polyester fiber has sufficient moisture absorption to obtain wearing comfort, and has a dry touch texture and high dyeing fastness and light resistance, and is used for underwear, shirts, blouses, middle garments, and sports. Clothing, slacks, outerwear,
It can be suitably used for bedding such as lining, curtains, wallpaper, sheets, futon covers, and wadding.

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Claims (6)

[Claims] (1) 1 to 20% by weight of silica-based inorganic particles having an average particle diameter of 0.01 to 10 μm, and
A polyester composition contained in a range of 0 ppm or less. 2. The polyester composition according to claim 1, wherein the silica-based inorganic particles are particles obtained by a wet method. 3. The particle has a pore volume of 0.5 ml / g or more, and has a pore volume (ml / g) and a specific surface area (m ²
/ G) is the following formula: 100 ≦ (specific surface area of particle / pore volume of particle) ≦ 150
0 4. The polyester composition according to claim 1, wherein the silica-based inorganic particles have a standard moisture absorption of 7% or more. 5. A fiber comprising the polyester composition according to claim 1. 6. The fiber according to claim 5, wherein the fiber has a moisture absorption of 1.0% or more.