JP2002275732A - Polyester fiber, method for producing the same, and polyester fiber structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To block silanol groups on the particle surface so as to suppress aggregation of silica particles and gelation of a polyester composition, but the blocked molecules are detached during production and the hygroscopic property is impaired. In order to prevent the silica particles from being removed, the silanol groups inside the hygroscopic silica particles that contribute to the hygroscopicity are not blocked, but only the silica fine particles existing near the particle surface are selectively blocked. A silica-based inorganic particle having a pore volume of 0.3 ml / g or more and a specific surface area of 300 m ² / g or more is treated with a reactive organic compound having a molecular weight of 500 or more, and the particle is formed into a polyester-based composition. Fiber containing an organic compound having a functional group capable of reacting with a silanol group in the vicinity of the particle surface by spinning using the composition mixed with the product. Get.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber having hygroscopicity and excellent in wearing comfort related to a refreshing feeling, a method for producing the same, and a fiber structure. More specifically, the present invention relates to a moisture-absorbing polyester fiber using moisture-absorbing fine particles.

[0002]

2. Description of the Related Art Hitherto, in order to improve the hygroscopicity of polyester fibers, studies have been widely made on modifying the polyester constituting the fibers or imparting a hydrophilic compound to the fiber structure. Here, as one of the methods for modifying the polyester, there is a method of mixing hygroscopic fine particles. Japanese Patent Application Laid-Open No. 2000-204230 discloses a method for absorbing and releasing hygroscopic porous inorganic particles containing 5 to 20% by weight. A polyester composition is disclosed. This polyester fiber was epoch-making in that a polyester fiber having high moisture absorption and desorption properties was obtained, but in particular, when silica-based inorganic particles were used as fine particles, the reactivity of the silanol groups on the surface was high. There has been a problem that particles agglomerate or react with polyester molecules to gel the composition, making it difficult to obtain practically sufficient fiber physical properties.

In order to prevent this problem, Japanese Patent Application Laid-Open
-204230 discloses a moisture-absorbing and desorbing polyester composition in which a hot-water-soluble polymer is present adjacent to the porous inorganic particles. However, in this method, a hot-water-soluble polyester composition is mixed in the process of mixing the porous inorganic particles with the polyester. Since the dissolved polymer detached from the particles and it was difficult to efficiently block the silanol groups on the silica particle surface, the problems caused by the silanol groups could not be sufficiently solved.

Further, as disclosed in Japanese Patent Application Laid-Open No. 7-286095, there is also known a method of blocking a silanol group on the particle surface with an organic compound having a functional group capable of reacting with a low molecular silanol group, particularly a silane coupling agent. Has been
When such a method is used, the hygroscopicity of the silica particles is impaired, and polyester fibers having high hygroscopicity cannot be obtained.

[0005]

In view of this situation, in the present invention, silanol groups on the particle surface are blocked so that aggregation of the particles and gelation of the polyester composition can be suppressed.
The silanol groups inside the hygroscopic silica particles, which contribute to the hygroscopicity of the hygroscopic silica particles, are not blocked, as in the previous methods, so that the sequestered molecules are not released during the production and the hygroscopicity is not impaired. The present invention provides a polyester fiber capable of selectively blocking only the silica fine particles present in the above, and a method for producing the same.

[0006]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the polyester fiber of the present invention is a polyester fiber containing silica-based inorganic particles having a pore volume of 0.3 ml / g or more and a specific surface area of 300 m ² / g or more, and a particle center near the particle surface. In which the reactive organic compound is present at a concentration of at least three times the amount of the reactive organic compound.

The method for producing a polyester fiber of the present invention has a pore volume of 0.3 ml / g or more and a specific surface area of 3 ml / g.
00m ² / molecular weight 50 silica-based inorganic particles g or more
The method is characterized in that the particles are treated with zero or more reactive organic compounds and the particles are spun using a composition obtained by mixing the particles with a polyester-based composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester fibers of the present invention include polyesters having an aromatic polyester such as polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate, and an aliphatic polyester such as polylactic acid and polycaprolactone as basic constituent units. Contains fibers. Among them, those comprising polyethylene terephthalate as a basic structural unit are desirable in view of strength and durability.

In the present invention, fibers comprising a copolymer obtained by copolymerizing the above-mentioned polyester with some other component, and fibers comprising a mixture obtained by blending a small amount of another organic polymer compound with these are also included. For example, compounds that can be used in place of terephthalic acid in polyethylene terephthalate 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. Examples of 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, aromatics such as bisphenol S, aliphatics, and the like. Examples thereof include alicyclic diol compounds and derivatives thereof.

Further, the polyester fiber of the present invention may contain a matting agent, a light-proofing agent, an antistatic agent, a deodorant, a fine pore-forming agent and the like as long as the effects of the present invention are not impaired.

In the present invention, from the viewpoint of excellent strength and durability, the polyester fiber constituting the polyester fiber is preferably 8%.
Desirably, the polyester is composed of alkylene terephthalate repeating units at 0 mol% or more.

In the embodiment, the polyester fiber of the present invention can be used as a polyester fiber structure. Examples of the polyester-based fiber structure include fabrics such as yarn, woven fabric, knitted fabric, and non-woven fabric made of polyester-based fiber. In addition, natural fibers such as cotton and wool and other synthetic fibers and the like are blended or mixed with the polyester fiber used in the present invention, twisted, interwoven, interwoven and the like within a range not to impair the effects of the present invention. Can be.

In the present invention, silica-based inorganic particles are used as the hygroscopic inorganic fine particles. Desirably, the silica-based inorganic particles of the present invention are porous, and the range of particle characteristics representing the porosity is such that the pore volume is 0.3 ml / g or more and the specific surface area is 3 or more.
Desirably, it is not less than 00 m ² / g. Particles having particle characteristics not in this range can only obtain particles having insufficient moisture absorption performance.

The silica-based inorganic particles of the present invention have a pore size of 2 to 2.
Preferably, it is 20 nm. The reason is that if the pore size is smaller than this, a large amount of water will be adsorbed from very low humidity,
This is because it is difficult to obtain moisture absorption and desorption properties under practical clothing wearing conditions, which are important for refreshing feeling, and if the pore diameter is larger than this, water will not be adsorbed unless it becomes very high humidity.
After all, it is difficult to obtain moisture absorption / release properties.

Further, it is desirable that the silica-based inorganic particles used in the present invention have an average particle size of 0.01 to 10 μm. When the particle size is less than 0.01 μm, the surface area of the particles becomes too large and the sealing tends to be insufficient, and when the particle size is larger than 10 μm, the yarn strength is liable to decrease. The more preferable average particle diameter of the inorganic fine particles is 0.1 to 2 μm.

The silica-based inorganic particles 4 used in the present invention
The content of the coarse particles having a size of not less than μm is desirably 5% by weight or less. When coarse particles having a particle size of 4 μm or more are contained in an amount exceeding 5% by weight, the coarse particles may serve as defects to lower the yarn strength.

The polyester fiber of the present invention desirably contains the silica-based inorganic particles in an amount of 0.01 to 20% by weight based on the weight of the polyester fiber in order to exhibit hygroscopicity. Here, if the amount of the silica-based inorganic particles is smaller than this, the hygroscopicity is insufficient, and if it is larger than this, practical properties such as fiber strength are reduced.

In the present invention, the organic compound having a functional group capable of reacting with a silanol group means any organic compound having a property of reacting with a silanol group on the surface of a silica-based particle. Types of functional groups related to reactivity include an alkoxy group, an epoxy group, an isocyanate group, an oxazoline group,
An acid anhydride part etc. can be mentioned.

In the present invention, an organic compound having a functional group capable of reacting with a silanol group is used so that the organic compound having a functional group capable of reacting with the silanol group does not reduce the hygroscopicity of the silica-based particle after reacting with the silica-based particle. It is characterized in that the compound is present in the vicinity of the particle surface at a concentration of at least three times the central part of the particle. Here, the vicinity of the particle surface means a distance within about 20% of the average particle diameter (diameter) from the particle surface (the interface between the particle and the polyester-based composition containing the particle) inside the particle. And a region outside the particle and within a distance of about 20% of the average particle diameter (diameter) from the particle surface. The particle center here means a region that is about 20% from the center of the particle.

As a method for confirming that the organic compound having a functional group capable of reacting with a silanol group according to the present invention is present in the vicinity of the surface of the silica-based particles at a concentration three times or more that of the center of the particle, A cross-section of a polyester fiber containing an organic compound having a functional group capable of reacting with a silanol group is exposed, and the existence form of the silica-based particles and the organic compound having a functional group capable of reacting with a silanol group is represented by X.
A method of observing with a line microanalyzer (XMA) is used. Here, the presence of the silica-based particles can be specified by the distribution of Si atoms, and the presence form of the organic compound having a functional group capable of reacting with a silanol group is determined by staining with a compound that selectively binds to the organic compound. It can be specified by looking at the distribution of atoms. In particular, when a compound containing a polyethylene glycol moiety is used as an organic compound having a functional group capable of reacting with a silanol group, a method of dyeing the compound with osmic acid and observing the distribution of osmium is used.

In the present invention, the expression that the organic compound having a functional group capable of reacting with a silanol group is present near the surface of the silica-based particles means that the compound adheres to the silica-based particles,
It means that they are combined. In the present invention, the compound is desirably bonded to a silanol group on the surface of the silica-based particles so that the silanol group is not unblocked during the production.

The organic compound having a functional group capable of reacting with a silanol group used in the present invention preferably has a molecular weight of 500 or more. Such a compound having a large molecular weight cannot penetrate into the pores of the silica-based particles, and selectively reacts mainly with silanol groups existing near the particle surface. For this reason, the silanol groups inside the particles that contribute to the development of the hygroscopicity are not blocked, and the high hygroscopicity is maintained, and the silanol groups on the surface that cause aggregation and gelation of the particles can be blocked. More preferably, the compound has a molecular weight of 1500 or more in order to more selectively react with the silanol group on the particle surface.

In the present invention, among organic compounds having a functional group capable of reacting with a silanol group, it is desirable to use a silane coupling agent having an alkoxy group. The reason for this is that the siloxane bond formed as a result of the reaction between the silane coupling agent and the silanol group is stable, and the blocked molecule is not easily released during the production. Examples of the silane coupling agent having a molecular weight of 500 or more include those containing a polyethylene glycol moiety, those containing a dimethylsiloxane moiety, and those having an alkoxy group bonded to various other polymers.

The organic compound having a functional group capable of reacting with a silanol group having a molecular weight of 500 or more of the present invention or the silane coupling agent preferably contains a hydrophilic group. The reason for this is that those containing hydrophilic groups are
This is because the decrease in the hygroscopicity of the silica particles when the silanol groups are blocked is small. Examples of the hydrophilic group include a hydroxyl group,
Examples thereof include a carboxyl group or a salt thereof, an ester group, a sulfonic acid group or a salt thereof, an amino group, an amide group, and an ethylene oxide moiety.

For the above two reasons, in the present invention, it is desirable to use a silane coupling agent having a molecular weight of 500 or more and containing a polyethylene glycol moiety as a hydrophilic one.

In order to confirm that the organic compound having a functional group capable of reacting with the silanol group of the present invention is bonded to the silanol group on the surface of the silica particle, the silica particle and the polyester fiber containing the compound are used. After dissolving the structure with a solvent, the particles are separated by centrifugation, and the particles are measured by a spectroscopic method such as IR or NMR to determine whether there is a peak due to the bond between the silanol group and the reactive organic compound. Just look. When the compound is a silane coupling agent,
This bond becomes a siloxane bond.

In order to confirm the molecular weight of an organic compound having a functional group capable of reacting with a silanol group existing in the vicinity of the surface of the silica-based particles, for example, the silica-based particles and a polyester fiber structure containing the compound are dissolved in a solvent. And then separating the particles by centrifugation, further separating the compound attached thereto by hydrolysis or the like, and then measuring the molecular weight by gel permeation chromatography (GPC).

In the present invention, the moisture absorption parameter ΔMR is 2% from the moisture content of the target material at 30 ° C. and 90% RH.
It refers to the value obtained by subtracting the water content at 0 ° C. and 65% RH. Here, each moisture content is 6.9 according to JIS L-1096.
It is determined by the method described in the section.

The moisture absorption parameter ΔMR of the polyester fiber of the present invention is preferably at least 2% in order to obtain high comfort when worn. Also, preferably, it is 4% or more in order to obtain higher comfort. The reason is that when MR and / or ΔMR is 2% or more, the same level of comfort as that of a blended material of cotton and polyester fiber, which is a typical refreshing material, can be obtained. This is because the same level of comfort can be obtained as that of the% material. Although ΔMR is preferably as large as possible, the effect of the present invention can be sufficiently exhibited if it is about 6%.

The hygroscopic property of the silica-based inorganic particles of the present invention is preferably such that the hygroscopic parameter ΔMR is 20% or more.
By mixing such silica-based inorganic particles into a polyester constituting a fiber in a certain amount or more, it is possible to obtain a polyester fiber having high hygroscopicity as described above.

It is desirable that the polyester fiber of the present invention has not only a hygroscopic property but also a moisture releasing property. As the moisture release parameter, for example, the target material is set at 20 ° C. and 6 ° C.
After being left at 5% RH for 24 hours, it is preferably 2% or more as ΔMR (moisture release), which is a change in moisture percentage when left at 30 ° C. and 90% RH and left for 24 hours. Preferably, it is 4% or more.

Next, in the process for producing a polyester fiber of the present invention, first, silica-based inorganic particles having a pore volume of 0.3 ml / g or more and a specific surface area of 300 m ² / g or more are treated with a silanol group having a molecular weight of 500 or more. The particles are treated with an organic compound having a functional group capable of reacting with the mixture, and the particles are mixed with the polyester composition. This mixing can be carried out at any stage during the esterification reaction of the polyester, the polycondensation reaction, or after the polycondensation reaction and before the melt molding. The treatment of the silica-based particles with an organic compound having a functional group capable of reacting with a silanol group may be performed simultaneously with the operation of mixing the particles with the polyester-based composition.

In the present invention, the conditions for treating the silica-based particles with an organic compound having a functional group capable of reacting with a silanol group are such that the reactive functionality of the compound sufficiently reacts with the silanol groups of the silica-based particles within a predetermined time. For example, when a silane coupling agent is used as the compound, the treatment may be performed at 100 ° C. for about 30 minutes.

In the production method of the present invention, the spinning is performed using the polyester composition containing the above-mentioned silica particles. In this spinning, for example, the composition may be melted at a temperature of 250 to 300 ° C., discharged using a die having a desired cross-sectional shape, and then taken off. Furthermore, if the undrawn yarn obtained here is drawn using a normal drawing machine, a polyester fiber having physical properties that can withstand general use can be obtained. Further, this drawing may be performed continuously without winding after winding the spun yarn, or may be performed at a high speed of 4000 m / min or more to obtain desired fiber physical properties at a stroke without substantially drawing. You may take it.

The polyester fiber of the present invention has sufficient hygroscopicity to obtain comfortable wearing and has few practical problems such as a decrease in yarn strength as conventionally observed.
It is suitably used for high-performance sports materials and working uniforms.

[0036]

EXAMPLES The present invention will be described below more specifically with reference to examples.

The measurements in the examples and comparative examples were performed by the following methods. <ΔMR> Put a sample in a weighing bin, and store at 20 ° C and 65% RH
It was left in a thermo-hygrostat adjusted to 24 hours for 24 hours and weighed. Then, the mixture was placed in a thermo-hygrostat adjusted to 30 ° C. and 90% RH.
It was left for 4 hours and weighed again. Finally, it was dried in a dryer at 110 ° C. for 1 hour to determine the absolute dry weight. The difference in the water content was calculated by the following equation.

ΔMR (%) = ((W′−W) / W− (W ″ −W) / W) × 100 W: Absolute dry weight (g) of sample W ′: 30 ° C., 90% RH Weight of sample (g) W ": Weight of sample at 20 ° C. and 65% RH (g) <XMA observation> Polyethylene glycol in a section of a fiber sample was stained with osmic acid, and the distribution of osmium was measured by XMA. did. Furthermore, the signal intensity at the center of the silica particles and the signal intensity near the surface were compared, and the ratio was determined. <Measurement of yarn strength> Using a Tensilon tensile tester manufactured by Toyo Baldwin Co., Ltd., a sample length of 20 cm and a tensile speed of 10
The value was determined from the stress-strain curve under the condition of cm / min. Example 1 Polyethylene glycol having an average particle size of 1.9 μm, a pore volume of 0.8 ml / g, a specific surface area of 500 m ² / g, a silica particle having a pore size of 7 nm at 10% by weight, and a number average molecular weight of 1500 An ethylene glycol solution containing triethoxysilane at a concentration of 5% by weight was prepared and heat-treated at 100 ° C. for 30 minutes.

Thereafter, 193 parts of dimethyl terephthalic acid, 124 parts of ethylene glycol and 0.05 part of cobalt acetate were added as a polyester, and transesterification was carried out at 140 to 230 ° C. while distilling off methanol. 0.08 parts of an ethylene glycol solution, 100 parts of an ethylene glycol solution obtained by treating the above silica particles with polyethylene glycol triethoxysilane, and 0.1 part of antimony trioxide were added, and polymerization was performed under reduced pressure at 290 ° C. Performed to obtain a polyester composition. The content of the silica particles in the obtained polyester composition was 5% by weight.

The polyester composition was melted at 290 ° C. and discharged from a concentric die at a discharge rate of 25 g / min.
An undrawn yarn was taken up at a spinning speed of 0 m / min. Next, by drawing and heat-treating, polyester fibers of 83 dtex 24 filaments were obtained.

As a result of XMA observation of the cross section of the fiber, the ratio of the signal intensity due to polyethylene glycol between the center of the silica particle and the vicinity of the surface was 5.1. It was confirmed that polyethylene glycol triethoxysilane was present in a concentration of twice or more. Further, the ΔMR of this fiber was 2.1%, the hygroscopicity was high, and the yarn strength was 4.5 CN / dtex, which proved to be practically sufficient. Example 2 The same operation as in Example 1 was performed except that the concentration of the silica particles in the ethylene glycol solution when treating the silica particles was 20% by weight and the concentration of the polyethylene glycol triethoxysilane was 10% by weight.

As a result, the ratio of the signal intensity attributable to polyethylene glycol in the center of the silica particle to the vicinity of the surface in the XMA observation was 5.3, and it was confirmed that the signal strength near the surface of the particle was more than three times that of the center of the particle. It was confirmed that the polyethylene glycol-modified alkoxysilane was present. Further, the ΔMR of this fiber was 4.3%, the hygroscopicity was high, and the yarn strength was 3.8 CN / dtex, which was confirmed to be practically sufficient. Comparative example 1 It carried out like Example 1 except not using polyethylene glycol triethoxy silane.

As a result, no signal due to polyethylene glycol was observed by XMA observation. Although the fiber had a ΔMR of 1.2% and obtained a hygroscopic property, the fiber strength was 1.8 CN / dtex, which was insufficient for practical use. Comparative Example 2 The same procedure as in Example 1 was carried out except that the concentration of the silica particles in the ethylene glycol solution at the time of treating the silica particles was 30% by weight and the concentration of the polyethylene glycol triethoxysilane was 15% by weight.

As a result, the ratio of the signal intensity attributable to polyethylene glycol in the center of the silica particle to the vicinity of the surface in XMA observation was 5.0. It was confirmed that polyethylene glycol-modified alkoxysilane was present.
R also showed high hygroscopicity of 5.7%, but the yarn strength was 1.
0CN / dtex was insufficient for practical use. Comparative Example 3 In the same manner as in Example 1 except that ethyltriethoxysilane having a molecular weight of 178 was used instead of the polyethylene glycol-modified alkoxysilane.

As a result, no signal due to polyethylene glycol was observed by XMA observation. The yarn strength of this fiber was 3.8 CN / dtex, but the ΔMR was 0.2
%, High hygroscopicity was not obtained. Example 3 Example 1 was repeated except that silica particles having an average particle size of 3.5 μm, a pore volume of 0.44 ml / g, a specific surface area of 700 m ² / g, and a pore size of 2.5 nm were used as the silica particles.
The same was done.

As a result, the ratio of the signal intensity attributable to polyethylene glycol in the center part of the silica particle to the vicinity of the surface in the XMA observation was 8.0, and it was confirmed that the signal strength near the particle surface was more than three times the concentration of the particle center part. It was confirmed that the polyethylene glycol-modified alkoxysilane was present. Further, the ΔMR of this fiber was 0.5%, a certain degree of hygroscopicity was obtained, and the yarn strength was 3.4 CN / dtex, which proved to be practically sufficient. Example 4 Same as Example 1 except that silica particles having an average particle size of 2.5 μm, a pore volume of 1.25 ml / g, a specific surface area of 300 m ² / g, and a pore size of 17 nm were used as the silica particles. I went to.

As a result, the ratio of the signal intensity attributable to polyethylene glycol in the center part of the silica particle to the vicinity of the surface in the XMA observation was 4.5, and it was confirmed that the signal strength in the vicinity of the particle surface was more than three times that of the particle center. It was confirmed that the polyethylene glycol-modified alkoxysilane was present. The ΔMR of this fiber was 0.9%, a certain degree of hygroscopicity was obtained, and the yarn strength was 3.8 CN / dtex, confirming that it was practically sufficient.

[0048]

According to the present invention, the polyester fiber of the present invention has sufficient hygroscopicity to obtain comfortable wearing. In addition, since there are few practical problems such as a decrease in yarn strength as seen in the related art, it can be widely used in a very wide range, such as high-performance sports materials and working uniforms.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D04B 21/00 D04B 21/00 BF Term (Reference) 4L002 AA07 AB02 AC00 EA03 FA01 4L035 BB40 EE05 EE08 JJ05 KK01 KK03 KK05 KK10 4L036 MA05 MA37 UA25 4L048 AA20 AA46 AA54 AA56 AC15 CA07 DA03

Claims (9)

[Claims] 1. A polyester fiber containing silica-based inorganic particles having a pore volume of at least 0.3 ml / g and a specific surface area of at least 300 m ² / g. A polyester fiber comprising an organic compound having a functional group capable of reacting with a silanol group at a concentration of twice or more. 2. The polyester fiber according to claim 1, wherein the organic compound having a functional group capable of reacting with the silanol group is a silane coupling agent. 3. The polyester fiber according to claim 1, wherein the silane coupling agent contains a polyethylene glycol moiety and / or a dimethylsiloxane moiety. 4. The polyester fiber according to claim 1, wherein the fiber has a moisture absorption parameter ΔMR of 2% or more. 5. The polyester fiber according to claim 1, wherein at least 80 mol% of the polyester constituting the fiber is a polyester comprising an alkylene terephthalate repeating unit. 6. A polyester fiber structure comprising the polyester fiber according to claim 1. 7. Silica-based inorganic particles having a pore volume of 0.3 ml / g or more and a specific surface area of 300 m ² / g or more are treated with an organic compound having a molecular weight of 500 or more and capable of reacting with a silanol group. And spinning using a composition in which the particles are mixed with a polyester-based composition. 8. The method according to claim 7, wherein the organic compound having a functional group capable of reacting with the silanol group is a silane coupling agent. 9. The method for producing a polyester fiber according to claim 7, wherein said silane coupling agent contains a polyethylene glycol moiety.