JP2001055631A - Antimicrobial polyamide potentially crimpable yarn and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain antimicrobial polyamide potentially crimpable yarn consisting of polyamide fiber with high whiteness, capable of imparting the fabrics therefrom with sufficient stretchability and softness, containing an antimicrobial agent, and causing no discoloration even if put to thermal and chemical treatments in a series of texturing processes, and to provide a method for producing such yarn. SOLUTION: This antimicrobial polyamide potentially crimpable yarn consists of side-by-side type conjugate fiber composed of two kinds of polyamide resins differing in viscosity from each other; wherein the higher-viscosity polymer is a nylon 6/66 copolymer 3.0-3.5 in relative viscosity, while the lower-viscosity polymer is a nylon 6 with a relative viscosity of 2.0-2.9. Further, this yarn contains 0.1-5.0 wt.%, based on the whole fiber, of zinc oxide microparticles with the surface coated with a coupling agent, having an initial Young's modulus of 15-25 g/d and percentage crimp of >=40%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial polyamide latently crimped yarn in which two kinds of polymers having different viscosities are bonded in a side-by-side type and has both a potential crimping property and an antibacterial property, and a method for producing the same. .

[0002]

2. Description of the Related Art Conventionally, polyamide fibers have been widely used for clothing. A single yarn made of one kind of polymer such as nylon 6 or nylon 66, which is a representative of polyamides for clothing, has little elasticity in the fiber itself. Used for certain woven and knitted fabrics. However, it is difficult to obtain a cloth having a sufficiently satisfactory elasticity by processing such a single yarn.

[0003] In view of the above, many methods have been proposed for obtaining stretchable fabrics by using polymers having different properties and forming conjugate fibers having latent crimping ability to exhibit crimping by heat treatment such as dyeing.

A conjugate fiber having such a potential crimping performance is a fiber having a side-by-side cross-sectional shape.
Generally, two kinds of polymers having different viscosity differences or polymers having different hot water shrinkage rates are used.

[0005] Since such fibers do not require post-processing, they are advantageous in terms of manufacturing cost, and although it was possible to give a certain degree of expansion / contraction to the fabric, it provided a sufficiently satisfactory degree of expansion / contraction. I couldn't do that. Furthermore, such a polyamide fiber has a problem that the initial Young's modulus is higher than that of polyurethane or the like, the flexibility is poor, and only a fiber having a hard feeling can be obtained when it is made into a fabric.

[0006] In recent years, various antibacterial fibers have been put into practical use due to diversification of consumers' values and consciousness of hygiene. Many antibacterial fibers containing antibacterial powder in synthetic fibers such as polyamide fibers such as nylon 6 have been proposed.

Among them, silver-based inorganic antibacterial agents are widely used as antibacterial agents, and phosphate-based antibacterial agents carrying silver ions, zeolite-based antibacterial agents carrying silver ions, and silver-based antibacterial agents. Hydroxyapatite fired product-based antibacterial agents and the like are used.

[0008] Fibers containing such silver-based inorganic antibacterial agents have good antibacterial properties and excellent durability, but they have a high thermal resistance in a series of processing steps such as warping, weaving, scouring and dyeing. In addition, there has been a defect that silver, which is an antibacterial component, is oxidized due to chemical treatment or sweating when worn for clothing, so that coloring and discoloration are likely to occur, and antibacterial properties are also reduced.

Therefore, in order to prevent discoloration and improve the whiteness of the fiber, antibacterial fibers treated with a discoloration inhibitor such as sodium percarbonate, sodium hypochlorite, or an azole compound having no mercapto group are used. JP-A-4-5
No. 0376, JP-A-6-264360, and JP-A-6-272173. However, these fibers cannot sufficiently avoid discoloration (coloring) when performing various treatments in a series of processing steps only by treatment with a discoloration inhibitor, and the treatment is complicated, such as for clothing. However, there is a problem that it is difficult to use it for applications requiring whiteness.

As described above, a latently crimped polyamide yarn which can be advantageously obtained in terms of cost and which can impart sufficient stretchability and flexibility to a fabric, comprising an antibacterial agent, Polyamide fibers that have excellent whiteness without coloration or discoloration even when subjected to thermal and chemical treatments in a series of processing steps as well as heat treatment for developing crimpability are still proposed. Absent.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and a polyamide capable of imparting sufficient elasticity and flexibility to a fabric by bonding two types of polymers having different viscosities in a side-by-side type. It is a latent crimped yarn, containing an antibacterial agent, and does not cause coloring or discoloration even when subjected to thermal and chemical treatment in a series of processing steps,
An object of the present invention is to provide an antibacterial polyamide latent crimped yarn having excellent whiteness and sufficient antibacterial performance and a method for producing the same.

[0012]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention relates to a fiber in which two kinds of polyamide resins having a difference in viscosity are bonded in a side-by-side type, and the high-viscosity polymer is a nylon 6/66 copolymer having a relative viscosity of 3.0 to 3.5. The viscosity polymer is nylon 6 having a relative viscosity of 2.0 to 2.9, and contains 0.1 to 5.0% by weight of the entire fiber of zinc oxide fine particles whose surface is coated with a coupling agent. Rate is 15-2
The gist of the present invention is a latently crimped antibacterial polyamide yarn having a crimp rate of 5 g / d and a crimp rate of 40% or more.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The latently crimped yarn of the present invention is a fiber in which two types of polyamide resins having a difference in viscosity are bonded in a side-by-side type, and the high-viscosity polymer has a relative viscosity of 3.0 to 3.5.
Nylon 6/66 copolymer and low viscosity polymer are nylon 6 having a relative viscosity of 2.0 to 2.9.

The high-viscosity polymer has a large hot water shrinkage,
Furthermore, the relative viscosity is 3.0 so that high-speed spinning is possible.
Must be ~ 3.5. Therefore, when the relative viscosity exceeds the upper limit, the spinning property during high-speed spinning is poor, and when the relative viscosity is low, the crimping performance is poor.

As such a high-viscosity polymer, a copolymer obtained by copolymerizing nylon 6 with nylon 66 is used. The copolymerization ratio of nylon 66 is preferably 5 to 20 mol%.

The low-viscosity polymer has a low hot water shrinkage ratio and nylon 6 as an inexpensive polymer in order to obtain high crimping performance, and has a relative viscosity of 2.0 to 2.0.
9, more preferably 2.3 to 2.7. If it is less than 2.0, the difference in viscosity from the high-viscosity polymer becomes too large, and the yarn bending becomes large, and the yarn-making properties deteriorate. On the other hand, 2.9
If it exceeds, the difference in viscosity from the high-viscosity polymer becomes small, and the crimping performance becomes poor.

Therefore, the difference between the relative viscosities of the high viscosity polymer and the low viscosity polymer is preferably 0.4 to 1.2,
More preferably, it is 0.5 to 1.0.

The latently crimped yarn of the present invention is obtained by laminating a high-viscosity polymer and a low-viscosity polymer in a side-by-side manner, and the ratio of both components and the shape of the laminating surface are not particularly limited. However, it is preferable that the weight ratio of the high-viscosity polymer / low-viscosity polymer is about 2/1 to 1/2.

The latent crimped yarn of the present invention has an initial Young's modulus of 15 to 25 g / d, more preferably 15 to 20 g / d.
g / d. By setting the initial Young's modulus within this range, the fabric can have appropriate flexibility.
Therefore, when the initial Young's modulus is less than 15 g / d, the fabric becomes too soft, and when it exceeds 25 g / d, the fabric becomes poor in flexibility and hard feeling.

Further, the latently crimped yarn of the present invention needs to have a crimping ratio of 40% or more when latently crimped in order to obtain a fabric having good stretchability. If it is smaller than this, the elasticity is inferior, which is not preferable.

Here, the term "crimp rate" means that the latently crimped yarn of the present invention was subjected to scabbing five times with a fineness measuring scale to form a double loop, and a load of 1/6000 g / d was applied. After being immersed in boiling water for 30 minutes in this state, take out, air-dry for 30 minutes in that state, change the load to 1/500 g / d, measure the length A, and apply a 1/20 g / d load. Is calculated by the following equation. Crimp rate (%) = [(BA) / B] × 100

If the relative viscosity of the high-viscosity polymer is changed within the above range, the crimp ratio can be adjusted to some extent.

The fiber of the present invention is used as an antibacterial agent
Fine particles of zinc oxide whose surface is coated with a coupling agent are contained in an amount of 0.1 to 5.0% by weight of the whole fiber.
That is, both the high-viscosity polymer and the low-viscosity polymer may contain an antibacterial agent or only one of them, but it is preferable that the high-viscosity polymer and the low-viscosity polymer are contained in a large amount near the surface of the fiber.

The antibacterial agent is a zinc oxide fine particle whose surface is coated with a coupling agent. Zinc oxide fine particles
In addition to the action of absorbing and deodorizing ultraviolet rays, it has a bactericidal and antibacterial action, but because of its photocatalytic activity, it causes photodegradation when contained in resin, resulting in inferior physical properties of the resulting fiber. Disadvantage.

That is, the photocatalytic activity of the zinc oxide fine particles is a reaction on the particle surface, and attempts have been made to suppress the activity by treating the surface of the particles. For example, a microencapsulated surface treatment for cutting off contact with oxygen or water has been performed, and the zinc oxide fine particles subjected to this treatment optically have the properties of zinc oxide, but have a chemical property. Had the problem of losing the properties of zinc oxide.

Therefore, in the present invention, in order to suppress the photocatalytic activity, which is a drawback of the zinc oxide fine particles, and to have the properties of zinc oxide both optically and chemically, the surfaces of the particles are coupled. The one coated with the agent is used.

The coupling agent is not particularly limited, but a silane coupling agent is preferable. For example, a silane coupling agent KBM-4 manufactured by Shin-Etsu Chemical Co., Ltd.
03, KBM-503.

Examples of the coupling agent other than the silane coupling agent include coupling agents such as titanium-based, aluminum-based, zirconium-based, and zirco-aluminate-based coupling agents.

The coating amount of the coupling agent depends on the surface area of the zinc oxide fine particles.
It is preferable to be about weight%. Since the surface of the zinc oxide fine particles is coated with the coupling agent in this manner, the photocatalytic activity of the zinc oxide fine particles can be sufficiently suppressed without waste with a small amount of coating.
It is possible to maintain the functions of ultraviolet absorption, antibacterial, sterilization, and the like as they are. Therefore, fibers containing zinc oxide fine particles whose surface is coated with such a coupling agent,
Discoloration due to ultraviolet rays is prevented, and at the same time, effects such as antibacterial and sterilization are achieved.

It is considered that the bactericidal and antibacterial properties of the zinc oxide fine particles are exhibited by high affinity with sulfur, which is one of the chemical properties of zinc oxide. In other words, it is presumed that zinc oxide fine particles act in some way on the thiol group of the enzyme present in the cell membrane of the fungus to reduce the activity of the fungus.

In the fiber of the present invention, the content of the above-mentioned antibacterial agent is 0.1 to 5.0% by weight, more preferably 0.3 to 3.5% by weight of the whole fiber. When the content is less than 0.1% by weight, the fiber does not have sufficient antibacterial properties, and when the content exceeds 5.0% by weight, yarn breakage occurs during spinning or drawing, or weaving. Occasionally, thread breakage and fluff due to wear of guides, reeds, healds, etc. occur frequently, and the operability deteriorates. Furthermore, not only the antibacterial performance is saturated but the cost is increased, but also the yarn quality such as high elongation is reduced.

The zinc oxide fine particles are used to prevent problems such as abrasion of the guide in the process from spinning to winding, to improve the processability, and to prevent the nozzle pack pressure from increasing. 0.1-5.0μ diameter
m.

The fiber of the present invention has both a discoloration (coloring) prevention effect and an antibacterial effect by containing the above antibacterial agent, and has a color difference of 2.0 or less after alkali treatment. It is preferred that

The color difference after the alkali treatment in the present invention will be described. First, using a fiber of the present invention and a polyamide fiber not containing an antimicrobial agent (standard fiber: other properties are equivalent to the fiber of the present invention to be compared), a tubular knitting is performed using a circular knitting machine, and a sample is prepared. I do. Then, the alkali treatment is performed by boiling with a 0.1% aqueous sodium hydroxide solution for 30 minutes. Thereafter, the sample is washed with water, dehydrated, and air-dried, and based on the color difference described in JIS L0804 Gray Scale for Discoloration and Discoloration, the color difference of the standard fiber (untreated sample) is set to class 1, and the color is deeper than the standard fiber. It is determined visually that the color difference becomes larger as the color difference increases.

When the color difference after the alkali treatment exceeds 2.0, the degree of coloration of the fiber by thermal and chemical treatments in a series of processing steps such as scouring treatment is large, so that the fiber is required for whiteness. Is difficult to use, resulting in degraded fibers, and the antibacterial property may be significantly reduced due to the reaction with alkali, which is not preferable.

In the anti-bacterial polyamide latent crimped yarn of the present invention, if the high-viscosity polymer and the low-viscosity polymer are bonded in a side-by-side type, the cross-sectional shape of the fiber may be round or various shapes. From the viewpoint of antibacterial properties, it is preferable to use a variant. The irregular cross-sectional shape increases the surface area of the filament, sufficiently exerts the effect of the zinc oxide fine particles, and improves the antibacterial property. Thereby, the content of the zinc oxide fine particles can be reduced, so that the cost can be reduced.

As long as the effects of the present invention are not impaired for both high-viscosity polymers and low-viscosity polymers, various additives such as matting agents, flame retardants, pigments, etc. may be added in addition to the above antibacterial agents. Is also good.

Further, as long as the fiber of the present invention does not inhibit the expression of antibacterial properties, an anti-mite agent, a deodorant and the like may be applied to the fiber by post-processing, or the water-repellent treatment and the permeability may be provided. You may give wet waterproofing etc.

The fiber of the present invention has excellent flexibility and stretchability when formed into a fabric, and is particularly suitable for use in clothing, and has a strength of 3.0 to 4.0 g / d and an elongation of 35 to 35. 45%,
It has a hot water shrinkage of 10 to 25% and a single fiber fineness of about 2.0 to 6.0 d.

Next, a method for producing the latently crimped antibacterial polyamide yarn of the present invention will be described. First, a polyamide resin chip containing zinc oxide fine particles whose surfaces are coated with a coupling agent is manufactured. That is, when it is contained in a high-viscosity polymer, it is used in a nylon 6/66 copolymer having a relative viscosity of 3.0 to 3.5, and when it is contained in a low-viscosity polymer, it is used in a nylon having a relative viscosity of 2.0 to 2.9. 6 to produce a chip.

At least the chip containing the zinc oxide fine particles has a moisture content of 0.05 to 2.0% by weight.
It is prepared so that When it is contained in either one of the polymers, it is preferable to adjust the moisture content of the polymer chips not containing the zinc oxide fine particles to be 0.05 to 2.0 weight.

Thereafter, the two kinds of polyamides having the difference in viscosity are melt-spun using a spinneret. At this time, melt spinning can be performed with a conventional side-by-side spinneret using a conventional composite spinning apparatus.

Then, the spun yarn is cooled and solidified, an oil agent is applied, and the yarn is wound up at a speed of 4000 m / min or more.
A highly oriented undrawn yarn is obtained, drawn into the obtained highly oriented undrawn yarn,
It is preferable to perform a heat treatment.

At this time, it is preferable to wind up at a speed of 4000 m / min or more. If the speed is lower than 4000 m / min, the stretching ratio increases in the subsequent stretching step, and as a result, the crimping performance decreases and the initial Young's modulus decreases. Higher and less flexible.

Regarding the stretching and heat treatment applied to the obtained highly oriented undrawn yarn, the stretching is preferably performed at a draw ratio of 1.2 to 1.5 times, and the heat treatment is preferably performed at 120 to 160 ° C.
In the production method of the present invention, the order of heat treatment and stretching is
Preferably, the stretching and the heat treatment are performed simultaneously, or the heat treatment is performed after the stretching.

If the stretching ratio is less than 1.2 times, the strength becomes poor and the crimp ratio tends to be low.
If it is more than 5 times, the initial Young's modulus is high, and the flexibility tends to be poor.

Regarding the heat treatment, the high-viscosity polymer has low crystallinity, and unless subjected to an appropriate heat treatment, the hot water shrinkage is large. In addition to the shrinkage due to crimping, the fiber itself may also shrink. It is preferable to perform a heat treatment at 120 to 160 ° C. If the heat treatment temperature is lower than 120 ° C., the shrinkage of the fiber itself cannot be prevented.
When the temperature exceeds 60 ° C., the hot water shrinkage of the high-viscosity polymer decreases, and the potential crimping performance tends to decrease.

The heat treatment and the stretching can be performed by a stretching device using a conventional stretching pin or roller. However, when performing the false twisting simultaneously, the stretching and the heat treatment may be performed by a false twisting machine. .

[0049]

Next, the present invention will be described specifically with reference to examples. The measurement and evaluation of each physical property value in the examples were performed as follows. (A) Relative viscosity The relative viscosity was measured at a concentration of 1 g / dl and a temperature of 25 ° C. using 96% sulfuric acid as a solvent. (B) Strong elongation, initial Young's modulus Using an autograph AGS-5G manufactured by Shimadzu Corporation, J
It was measured according to IS L 1013. (C) Hot water shrinkage ratio The yarn was formed into a loop of 50 cm, a length A was determined by applying an initial load of 1/30 g / d, then freed, immersed in boiling water for 15 minutes, air-dried, and dried again. 1 / 30g / d
Was applied to obtain the length B, which was calculated by the following equation. Hot water shrinkage rate (%) = [(AB) / A] × 100 (d) Crimp rate Measured by the method described above. (E) Antibacterial property Using the obtained antibacterial fiber of the present invention and a knitted fabric obtained by knitting a crimped yarn, a quantitative antibacterial test method (unified) for textile products determined by the Council for Evaluation of New Functions of Textile Products (SEK) Test method)
According to the manual, Staphylococcus aureus (St.
aphylococcus aureus ATCC 6538P) was used to measure the bacteriostatic activity and evaluate the antibacterial activity. The samples were evaluated for untreated, alkali-treated, dyed, 10-washed, and weathered (the untreated sample was directly subjected to weathering). The alkali treatment was carried out by boiling for 30 minutes in a 0.1% aqueous solution of sodium hydroxide.
And the weathering treatment is performed according to JIS L 1013. (F) Color difference after alkali treatment This was performed by the method described above. (G) Whiteness Eight knits obtained by knitting the fibers after alkali treatment into a tube are stacked, and chromaticity coordinate values are obtained using a spectrophotometer (Macbeth, CE-3100).
The aub whiteness was measured.

Example 1 Nylon 6 having a relative viscosity (measured at a concentration of 1 g / dl and a temperature of 25 ° C. using 96% sulfuric acid as a solvent and a temperature of 25 ° C.) of 2.50 was used as a low-viscosity polymer. 10
(A copolymer amount of nylon 66 was 15 mol%). Zinc oxide fine particles (Z-NOUVE manufactured by Mitsui Kinzoku Co., Ltd., diameter: 0.5-
1.0 μm) so as to be 1.0% by weight of each polymer to produce a chip. The moisture content of these chips was adjusted to be 1.0% by weight. The chips of both polymers are supplied to a conventional composite melt spinning apparatus, and a side-by-side composite spinneret having a round cross section is attached, and the composite ratio (weight ratio) of the low-viscosity polymer and the high-viscosity polymer is set to 1: 1. And melt spinning at a polymer temperature of 270 ° C.
After cooling this conjugate fiber and applying the oil agent, the speed 436
0 m / min on the first roller, followed by the second roller at a speed of 4370 m / min without stretching,
Wound on a winder at a speed of 4300m / min and 65d /
A highly oriented undrawn yarn having a round cross section of 12f was obtained. Next, the obtained highly oriented undrawn yarn was applied once to a non-heated drawing pin (made of alumina) having a diameter of 6 mm in a drawing zone to obtain a draw ratio of 1.3.
While stretching to double the length, length 30cm, temperature 16
It was heat-treated by contacting it with a heating plate at 0 ° C., taken up at a speed of 680 m / min, wound up using a traveler # 32 on a pan having a spindle rotation speed of 7,600 rpm, and a latent crimped yarn of 50d / 12f was obtained.

Example 2 The content of the antibacterial agent in the low-viscosity polymer was set to 3.0% by weight of the weight of the low-viscosity polymer (the content of all antibacterial agents was 2.0% by weight of the whole fiber), and the water content of the chip was adjusted. 0.05% by weight
The procedure was performed in the same manner as in Example 1 except that the composition was adjusted.

Example 3 The content of the antibacterial agent in the low-viscosity polymer was 2.0% by weight of the weight of the low-viscosity polymer, and no antibacterial agent was contained in the high-viscosity polymer. 1 of the whole fiber.
0% by weight) in the same manner as in Example 1.

Example 4 The same procedure as in Example 1 was carried out except that a side-by-side composite spinneret having a cross section of 6 leaves was used.

Comparative Examples 1 to 4 The same procedures as in Example 1 were carried out except that the relative viscosities of the high-viscosity polymer and the low-viscosity polymer were changed as shown in Table 1.

With respect to the fibers obtained in Examples 1 to 4 and Comparative Examples 1 to 4, the content of the antibacterial agent, strength, elongation, hot water shrinkage, initial Young's modulus, crimping ratio, antibacterial properties, alkali treatment Table 1 shows the evaluation results of the color difference and whiteness later.

[0056]

【table 1】

As is clear from Table 1, the anti-bacterial polyamide latent crimped yarns obtained in Examples 1 to 4 have sufficient crimping performance and low initial Young's modulus, and have strength and elongation. Excellent,
The yarn formability was also good. In addition, the evaluation of antibacterial properties is good, the color difference after alkali dyeing is small, the whiteness evaluation is high, and it can be used well in fields where whiteness is required and fields used for dyeing. there were. On the other hand, Comparative Example 1
Was a fiber having low crimpability because the relative viscosity of the high-viscosity polymer was too low. In Comparative Example 2, since the relative viscosity of the high-viscosity polymer was too high, thread breakage occurred frequently and could not be wound up. In Comparative Example 3, since the relative viscosity of the low-viscosity polymer was too high, the difference in viscosity between the low-viscosity polymer and the high-viscosity polymer was small, and the fiber had a low crimp ratio. In Comparative Example 4, since the relative viscosity of the low-viscosity polymer was too low, the difference in viscosity from the high-viscosity polymer was too large, the yarn was severely bent, and the yarn was difficult to be formed, and could not be wound.

[0058]

As described above, the antibacterial polyamide latent crimped yarn of the present invention has a high crimp ratio when a latent crimp is developed and a low initial Young's modulus. The fabric has elasticity and flexibility. Furthermore, not only heat treatment for expressing good antibacterial properties and latent crimping, but also thermal and chemical treatment in a series of processing steps such as warping, weaving, scouring, dyeing processing and clothing use There is almost no discoloration (coloring) or decrease in antibacterial properties due to sweating during wearing, and it can be suitably used in fields where whiteness is required or fields where dyeing is used.

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Claims (3)

[Claims] 1. A fiber in which two kinds of polyamide resins having different viscosities are bonded in a side-by-side type, and the high-viscosity polymer is nylon 6/300 having a relative viscosity of 3.0 to 3.5.
66 copolymer and low viscosity polymer have relative viscosities of 2.0 to 2.
Nylon 6 of which the surface of the particles is coated with a coupling agent is zinc oxide fine particles of 0.1-5.
An antibacterial polyamide latent crimped yarn containing 0% by weight, having an initial Young's modulus of 15 to 25 g / d and a crimping ratio of 40% or more. 2. The latently crimped antibacterial polyamide yarn according to claim 1, wherein the color difference after the alkali treatment is 2.0 or less. 3. Side-by-side spinning of a polyamide resin chip containing zinc oxide fine particles whose surface is coated with a coupling agent so that the moisture content is 0.05 to 2.0% by weight. The method for producing a latently crimped antibacterial polyamide yarn according to claim 1 or 2, which is melt-spun from a die.