JPH11293521A - Antimicrobial polyamide fiber, antimicrobial polyamide crimped textured yarn, antimicrobial polyamide woven or knitted fabric, and production of antimicrobial polyamide fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antimicrobial polyamide fiber hardly causing discoloration and lowering of antimicrobial activities even if an alkali treatment is carried out, and useful for a woven or knitted fabric or the like by forming polyamide resin chips including a prescribed amount of zinc oxide fine particles coating-treated with a coupling agent into a fiber under a specified condition. SOLUTION: This antimicrobial polyamide fiber causing <=2.0 color difference after an alkali treatment and having a cross section shape of a modified cross section shape having 20-60% modified cross section degree is obtained by regulating the water-content of a polyamide chip including 0.1-5.0 wt.% zinc oxide fine particles subjected to a covering treatment with a silane-based coupling agent or the like, and melt-spinning the obtained polyamide chips. Preferably, crimps are imparted to the antimicrobial polyamide fiber to produce the antimicrobial polyamide crimped textured yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber made of a resin containing an antibacterial agent, and to an antibacterial polyamide fiber which causes little discoloration (coloring) even after alkali treatment, and a method for producing the same.

[0002]

2. Description of the Related Art There have been proposed a large number of antibacterial fibers in which synthetic fibers such as polyamide fibers such as nylon 6 contain powder having antibacterial properties. Among them,
Silver-based inorganic antibacterial agents are widely used as antibacterial agents,
A phosphate-based antibacterial agent carrying silver ions, a zeolite-based antibacterial agent carrying silver ions, a hydroxyapatite calcined product-based antibacterial agent carrying silver ions, and the like are used.

[0003] Fibers containing such silver-based inorganic antibacterial agents have good antibacterial properties and excellent durability, but wash away the paste applied in order to improve the weaving property in a step before dyeing. Therefore, when the alkali treatment is performed, silver, which is an antibacterial component, is oxidized and discolored (colored). As a result, the antibacterial property is reduced. Was.

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 have been developed. JP-A-4-5
No. 0376, JP-A-6-264360, and JP-A-6-272173. However, these fibers cannot sufficiently avoid discoloration (coloring) when subjected to an alkali treatment only by treatment with a discoloration inhibitor, and the treatment is complicated, and whiteness such as for clothing is required. There is a problem that it is difficult to use in some applications.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, exhibits good antibacterial properties, and exhibits almost no discoloration (coloring) or little decrease in antibacterial properties even after alkali treatment. Another object of the present invention is to provide an antibacterial polyamide crimped yarn.

[0006]

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 has the following (1) to (4). (1) It is composed of a polyamide resin containing 0.1 to 5.0% by weight of zinc oxide fine particles whose surfaces are coated with a coupling agent, and has a color difference of 2.0 after alkali treatment.
An antibacterial polyamide fiber characterized by the following. (2) A crimped antibacterial polyamide yarn obtained by crimping the antibacterial polyamide fiber according to (1). (3) An antibacterial polyamide woven or knitted fabric which is knitted and woven using at least a part of the antibacterial polyamide fiber according to (1) or the crimped antibacterial polyamide yarn according to (2). (4) A polyamide resin chip containing 0.1 to 5.0% by weight of zinc oxide fine particles whose surface is coated with a coupling agent so that the moisture content becomes 0.05 to 2.0% by weight. The method for producing an antibacterial polyamide fiber according to (1), wherein the melt is spun after the adjustment.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Fiber of the present invention (antibacterial polyamide fiber according to (1) and crimped antibacterial polyamide fiber according to (2))
Examples of the polyamide constituting the above include nylon 6, nylon 66, nylon 69, nylon 46, and the like alone, a copolymer thereof, or a blend thereof. And, as long as the effects of the present invention are not impaired,
It may contain a matting agent, a modifying agent, an antistatic agent, a pigment and the like.

The antibacterial agent contained in the fiber of the present invention is zinc oxide fine particles whose surface is coated with a coupling agent. Zinc oxide fine particles, in addition to the action of ultraviolet absorption and deodorization, have a bactericidal and antibacterial action, but because of their photocatalytic activity, they cause photodegradation when contained in resin, and the resulting fiber There is a disadvantage that physical properties are inferior.

That is, the photocatalytic activity of the zinc oxide fine particles is a reaction on the surface of the particles, 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.

Further, as coupling agents other than the silane coupling agent, coupling agents such as titanium-based, aluminum-based, zirconium-based, and zircoaluminate-based coupling agents can be mentioned.

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.

[0014] The sterilization and antibacterial properties of the zinc oxide fine particles are considered to be 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 zinc oxide fine particles whose surface is coated with a coupling agent in the polyamide resin is 0.1 to 5.0% by weight, preferably 0.3 to 5.0% by weight.
3.5% by weight. 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.

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 added to the fiber by post-processing. You may give wet waterproofing etc.

The fiber of the present invention has both the anti-discoloration (coloring) prevention effect and the anti-microbial effect by containing the above antibacterial agent, and has a color difference of 2.0 after alkali treatment.
It is as follows.

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.

If the color difference after the alkali treatment exceeds 2.0, the degree of coloration of the fiber by the alkali treatment such as scouring treatment is large, and it is difficult to use it for applications requiring whiteness, and the quality is deteriorated. It is not preferable because it becomes a fiber and the antibacterial property is remarkably reduced due to the reaction with the alkali.

[0021] In the antibacterial polyamide fiber of the present invention, it is preferable that the cross-sectional shape of the fiber is an irregular cross section having an irregularity of 20 to 60%. By adopting such an irregular cross-sectional shape, the surface area of the filament is increased, the effect of the antibacterial fiber of the present invention and the effect of the zinc oxide fine particles are sufficiently exhibited, and the antibacterial property is improved. As a result, the content of the zinc oxide fine particles can be reduced, so that the cost can be reduced.

The degree of irregularity in the fiber of the present invention means a value (%) obtained by dividing the diameter of the inscribed circle in the cross-sectional shape of the filament by the diameter of the circumscribed circle and multiplying by 100. Examples of such a shape include a polygonal shape such as a triangle or a square, a multi-leaf cross-sectional shape having a large number of irregularities, and a rice-shaped or well-shaped shape.

And, in the fiber of the present invention,
Irrespective of not being irregular, it may have a hollow part,
In order to avoid yarn breakage and fluffing during weaving, a core-sheath structure in which zinc oxide fine particles are contained in the core may be used.

Further, the fiber of the present invention may be a short fiber or a long fiber, and the long fiber may be a multifilament or a monofilament, and both the short fiber and the long fiber have a single fiber fineness of 0.5 to 90d.

When producing the fiber of the present invention, first, a polyamide resin chip containing 0.1 to 5.0% by weight of zinc oxide fine particles coated with a coupling agent is produced, and the moisture content of the chip is reduced. After adjusting to be 0.05 to 2.0% by weight, melt spinning is performed.

The coloring and discoloration of the obtained polyamide fiber is related to the moisture content in the resin chip. This is because the polyamide fiber is susceptible to degradation such as hydrolysis in a molten state. As the number increases, the coloring and discoloration of the obtained fibers increase. Therefore, by setting the moisture content of the resin chip within the above range, by melt spinning,
Fibers with less coloring after alkali treatment can be obtained. In order to keep the moisture content of the resin chip within the above range, the resin chip may be dried at about 90 to 160 ° C.

If the moisture content of the chip exceeds 2.0% by weight, the coloring and discoloration of the obtained fiber will increase, making it difficult to reduce the color difference after alkali treatment to 2.0 or less. Is less than 0.05% by weight, the process of drying the chips becomes longer, and the cost increases.
The physical properties such as the strength and elongation of the obtained fiber also tend to decrease.

And, as the polyamide fiber of the present invention,
When manufacturing long fibers (multi-filaments), a two-step method in which a spun undrawn yarn is once wound and then drawn,
After cooling the spun yarn, it may be produced by a direct spin drawing method in which the yarn is wound at a speed of 3000 m / min or more.

When the fiber of the present invention is produced by a two-step method of once winding and stretching after melt spinning, 700
It is wound up at a speed of about 1500 m / min.
Stretching is preferably performed at about 5 to 6.0 times, and depending on the type of yarn, hot drawing or cold drawing at room temperature may be performed. In the case of hot drawing, the drawing is preferably performed at about 50 to 170 ° C.

In the case of manufacturing by the direct spin drawing method,
It is manufactured by winding the melt-spun yarn at a speed of 3000 m / min or more without once winding. At this time, stretching may be performed before winding, and in this case, 50 to 150
It is preferable to perform hot stretching at a magnification of about 1.1 to 3.0 times while heating to about ° C.

Generally, when a fiber is produced by a direct spinning and drawing method using a polymer containing fine particles, guide abrasion is more likely to occur than in the two-step method, and yarn breakage and the like caused by this are likely to occur. Operability is likely to deteriorate. In the present invention, zinc oxide fine particles coated on the surface of the particles with a coupling agent are used, and an appropriate amount is contained, so that even if the direct spinning and drawing method is employed, guide abrasion does not occur,
It can be manufactured with good operability.

In the case of the crimped yarn of the present invention, the fiber obtained as described above is subjected to a crimping process. Method, an indentation crimping method, a fluid indentation crimping method using a heated fluid, and the like. Above all, the false twisting method is preferred in terms of quality stability and cost.

As the false twisting machine, a general false twisting machine equipped with a pin type or disk type twisting device can be used. The false twisting conditions may be appropriately selected in a general condition range, and usually, the false twist coefficient represented by the product of the number of false twists (T / M) and the square root of the fiber fineness (d) is 1500.
It is preferable to set it in the range of 0 to 33000. However, the present invention is not limited to these as long as crimps can be obtained, and a two-stage heater false twisting in which heat treatment is continuously performed to suppress torque after false twisting may be performed.

The antibacterial polyamide woven or knitted fabric of the present invention is obtained by knitting and weaving using at least a part of the antibacterial polyamide fiber or the crimped antibacterial polyamide yarn of the present invention. That is, the antibacterial polyamide woven or knitted fabric of the present invention preferably uses the antibacterial polyamide fiber and / or crimped yarn of the present invention for all of the fibers constituting the woven or knitted fabric. If, if the antibacterial polyamide fiber and or crimped yarn of the present invention in advance,
A fiber entangled with other fibers, a ply-twisted yarn, or the like, which has been manufactured and woven or woven from such a mixed-filament yarn or a ply-twisted yarn, or the antibacterial polyamide fiber and / or crimped yarn of the present invention. May be mixed and knitted with other fibers.

The proportion of the antibacterial fiber or the crimped yarn in the woven or knitted fabric as described above may be appropriately selected depending on the required application such as antibacterial performance and feeling. In addition, the conditions such as the structure at the time of forming the woven or knitted material are not particularly limited, and may be performed by a conventional method.

The antibacterial polyamide fiber and the crimped yarn of the present invention have a color difference of not more than 2.0 after alkali treatment and are excellent in whiteness. The woven or knitted fabric of the present invention used for part or all can be dyed in a desired color.

[0037]

Next, the present invention will be described specifically with reference to examples. In addition, the measurement of the characteristic value in an Example was performed as follows. (a) Strong elongation Measured in accordance with JIS L1090. (b) Antibacterial property Using the obtained antibacterial fiber of the present invention and a knitted fabric obtained by tubular knitting of crimped yarn, a quantitative antibacterial test method for textile products determined by the Council for Evaluation of New Functions of Textile Products (SEK) (Unified Test method)
According to the manual, Staphylococcus aureus (St.
aphylococcus aureus ATCC 6538P) was used to measure the bacteriostatic activity and to 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 sodium hydroxide solution, and the 10-washing was carried out by subjecting the sample after the alkali treatment and staining to JIS L 0217 103
And the weathering treatment is performed according to JIS L 1013. (c) Color difference after alkali treatment This was performed by the method described above. (d) Whiteness Eight knitted fabrics obtained by knitting the fibers after alkali treatment are piled up, and chromaticity coordinate values are obtained using a spectrophotometer (Macbeth, CE-3100), and T is calculated according to the method of ASTM E313.
The aub whiteness was measured.

Example 1 Zinc oxide fine particles 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) of 2.53, and a particle surface coated with a silane coupling agent as an antibacterial agent (Z-NOVE manufactured by Mitsui Kinzoku Co., diameter 0.5-1.0μ
m) using a nylon 6 chip containing 1.0% by weight of
After adjusting the moisture content of the chips to 1.0% by weight, the chips were supplied to an extruder-type melt extruder, and a spinning temperature of 260 ° C.
And discharged from a spinneret having 12 spinning holes having a hole diameter of 0.3 mm. Cooling air is blown from a cooling device to cool the yarn, and an oiling agent is applied by an oiling roller. Then, the yarn is wound at a winding speed of 4000 m / min, and 40 d / 1.
2f antibacterial fibers were obtained.

Examples 2 to 3 and Comparative Examples 1 to 3 The same procedure as in Example 1 was carried out except that the content of the antibacterial agent and the moisture content of the nylon 6 chip were variously changed as shown in Table 1.

Example 4 The same procedure as in Example 1 was carried out, except that the content of the antibacterial agent was changed as shown in Table 1, using a spinneret having twelve spin holes in a trilobal shape. The antibacterial fiber having a triangular cross section of 40d / 12f was obtained.

Table 1 shows the evaluation of the strength, elongation, antibacterial property, color difference after alkali treatment and whiteness of the fibers obtained in Examples 1 to 4 and Comparative Examples 1 to 3.

[0042]

[Table 1]

As is clear from Table 1, the antibacterial fibers obtained in Examples 1 to 4 have excellent thread properties such as high elongation and high antibacterial properties, and have a high color difference after alkali treatment. Also, the evaluation of whiteness was high, and it could be used well for applications requiring whiteness. In addition, Examples 1 to 3 were manufactured by the direct spinning and drawing method, but were able to be manufactured with good operability without guide abrasion or the like. On the other hand, Comparative Example 1 did not contain an antibacterial agent and thus did not have antibacterial properties, and Comparative Example 2 contained too much antibacterial agent,
Thread breakage occurred during spinning and drawing, the operability was poor, and the obtained fibers had poor yarn quality such as high elongation. In Comparative Example 3, since the melt spinning was performed in a state where the moisture content in the chips was high, the color difference of the obtained fibers after the alkali treatment was high.

Examples 5-6, Comparative Examples 4-5 The content of the antibacterial agent was changed as shown in Table 2, and the spinning hole was changed to 3
A feed roller, a false twist heater, a pin-type false twist twisting device, and an antibacterial polyamide fiber obtained in the same manner as in Example 1 except that a fiber of 70d / 34f was obtained using a spinneret having four yarns. Using a false twisting machine equipped with a delivery roller and a winding device in that order, the false twisting conditions were variously changed as shown in Table 2 to perform processing to obtain a crimped yarn. Table 2 shows the evaluation of the strength, elongation, antibacterial property, color difference after alkali treatment, and whiteness of the obtained crimped yarn.

[0045]

[Table 2]

As is apparent from Table 2, the antibacterial crimped yarns obtained in Examples 5 to 6 have excellent yarn properties such as high elongation, high antibacterial evaluation, and alkali treatment. The subsequent color difference was small, the evaluation of whiteness was high, and it could be used well for applications requiring whiteness. On the other hand, Comparative Example 4
Since it did not contain an antibacterial agent, it did not have antibacterial properties. In Comparative Example 5, since the content of the antibacterial agent was too large, yarn breakage occurred during spinning, drawing or false twisting, and the operation was stopped. The properties were poor, and the yarn quality such as the strength and elongation of the obtained fiber was also low.

Example 7 Using the fiber of Example 1 as warp and weft,
A plain woven fabric having 0 threads / 2.54 cm and a weft density of 108 threads / 2.54 cm was woven. The antibacterial properties, color difference after alkali treatment, and whiteness of these plain fabrics were measured and evaluated. In addition, these evaluations and measurements were performed on the knitted fabric among the evaluation and measurement methods described above with a woven fabric, and the whiteness was measured on a single woven fabric with a spectrophotometer.

Example 8 The procedure of Example 7 was repeated except that the crimped yarn of Example 5 was used as a warp and a weft to produce a plain fabric having a warp density of 114 yarns / 2.54 cm and a weft density of 86 yarns / 2.54 cm. The same was done.

Example 9 Using the fiber of Example 1 as a warp and the fiber of Comparative Example 1 as a weft, warp density 140 / 2.54 cm, weft density 108 / 2.54 cm
Was carried out in the same manner as in Example 7 except that the plain woven fabric (mixing ratio of antibacterial fiber: 56%) was woven.

Example 10 The entangled mixed yarn obtained by subjecting the crimped yarn of Example 5 and the crimped yarn of Comparative Example 4 to air entanglement using an interlacer JD-1 manufactured by DuPont was used as a weft. Example 2 was performed using the crimped yarn of Comparative Example 4 and weaving a plain woven fabric having a warp density of 114 yarns / 2.54 cm and a weft density of 62 yarns / 2.54 cm (mixing ratio of antibacterial crimped yarn of 26%) 7 was performed.

Example 11 Using the fiber of Example 1, a tricot knit was obtained with a mesh structure.

Example 12 Using the fiber of Example 1 and the fiber of Comparative Example 1, mixed knitted fabric (tubular knitting, mixing ratio of antibacterial fiber: 65
%).

Fabrics of Examples 7 to 10, Examples 11 to 12
Table 3 shows the evaluation results of the antibacterial property, the color difference after the alkali treatment, and the whiteness of the knitted fabric.

[0054]

[Table 3]

As is clear from Table 3, the woven or knitted fabric using all or a part of the antibacterial fiber or the crimped antibacterial yarn of the present invention has a high antibacterial property and a high color difference after alkali treatment. It was small, had a high evaluation of whiteness, and could be favorably used for applications requiring whiteness.

[0056]

The antibacterial polyamide fibers and crimped antibacterial polyamide yarns of the present invention exhibit good antibacterial properties, exhibit almost no discoloration (coloring) and no decrease in antibacterial properties even after alkali treatment. It has excellent elongation and can be sufficiently used for applications requiring whiteness. And according to the manufacturing method of the antibacterial polyamide fiber and the antibacterial polyamide crimped yarn of the present invention, the above-mentioned fiber and crimped yarn can be obtained with good operability. Furthermore, since the antibacterial polyamide woven or knitted fabric of the present invention uses the antibacterial polyamide fiber or the antibacterial polyamide crimped yarn of the present invention in at least a part thereof, it exhibits good antibacterial properties and is subjected to alkali treatment. There is almost no discoloration (coloring) or decrease in antibacterial properties,
It can be used satisfactorily for applications requiring whiteness, and can be dyed well.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI D06M 101: 34 (72) Inventor Masahiro Hosoda 5 Uji Tonouchi, Uji City, Kyoto Prefecture Unitika Uji Plant (72) Inventor Eiji Yamamoto Kyoto Uji Plant, Uji Tonouchi, Uji City, Uchi Plant Co., Ltd. (72) Inventor Mitsuo Omori Uji Tonouchi, Uji City, Kyoto Prefecture, Uchi Plant 5 Unitika Co., Ltd. Central Research Laboratory (72) Inventor Shuhei Kurata 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Research Laboratory Central Research Laboratory

Claims (5)

[Claims] 1. A polyamide resin containing 0.1 to 5.0% by weight of zinc oxide fine particles whose surface is coated with a coupling agent, and having a color difference of not more than 2.0 after alkali treatment. An antibacterial polyamide fiber, characterized in that: 2. A fiber having a cross-sectional shape of 20-60.
The antibacterial polyamide fiber according to claim 1, which has an irregular cross-sectional shape of 1%. 3. An antibacterial polyamide crimped yarn obtained by crimping the antibacterial polyamide fiber according to claim 1 or 2. 4. An antibacterial polyamide woven or knitted fabric which is knitted and woven using at least a part of the antibacterial polyamide fiber according to claim 1 or claim 2 or the crimped yarn of the antibacterial polyamide according to claim 3. 5. A polyamide resin chip containing 0.1 to 5.0% by weight of zinc oxide fine particles whose surface is coated with a coupling agent has a moisture content of 0.05 to 2.0% by weight. 3. The method for producing an antibacterial polyamide fiber according to claim 1 or 2, wherein melt spinning is performed after the adjustment.