JPH08151515A - Antimicrobial polyamide composition, its production and production of antimicrobial polyamide yarn - Google Patents

Abstract

PURPOSE: To obtain an antimicrobial polyamide composition, having both excellent antimicrobial properties and whiteness, providing a molded article such as antimicrobial yarn capable of extremely improving moldability without lowering its whiteness, consequently useful for various uses such as antimicrobial fibers attaching great importance to coexistence of antimicrobial properties and coexistence of color tone and moldability. CONSTITUTION: The particle size of high silica mordenite supporting 5-15wt.% of silver ion is adjusted to >=0.1μm number-average particle diameter and <=20wt.% particles having >=1μm particle diameter. The particles are substantially added to a polymerization process of a polyamide to produce an antimicrobial polyamide composition having 2-40wt.% of the particles based on the total amount of the component. The antimicrobial polyamide composition is mixed with a polyamide not containing an antimicrobial zeolite to concentrate the concentration of the antimicrobial zeolite and the blend is subjected to melt spinning to produce an antimicrobial polyamide yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial polyamide composition, a method for producing the same, and an improvement in the method for producing an antibacterial polyamide fiber comprising the same. More specifically, it relates to improving the whiteness and processability of the antibacterial polyamide composition and the antibacterial polyamide fiber.

[0002]

2. Description of the Related Art Zeolite particles having antibacterial properties, which carry metal ions such as silver, copper, zinc, etc., are blended in various resins because of their good antibacterial properties, safety and heat resistance, and fibers, films, It has been widely used as a raw material for imparting durable antibacterial properties to familiar resin molded articles such as various containers (JP-A-59-133235, etc.).

However, when zeolite particles are mixed with a resin to produce a molded article, there is a problem that the contacting device portion of the molded article is easily worn due to the contact running of the molded article. For example, in the case of a fiber, the fiber travels in contact with guides or the like in the processes of yarn making and post-processing, but since the contact point at that time is concentrated in a part of the guide or the like, alumina having higher hardness than zeolite or Even if a guide made of ceramics such as zirconia is used, there is a problem that abrasion easily occurs. Further, since such zeolite particles have a stronger cohesive force than other particles, there is a problem that the pressure inside the spinning pack is likely to be rapidly increased. Therefore, in the case of the fiber containing the zeolite particles, there is a problem that it is difficult to obtain good spinnability.

Moreover, since such zeolite particles have a small specific gravity, it is very difficult to make them fine enough by pulverization or classification as in the case of making titanium oxide particles fine. Therefore, there is a problem that even if finely blended by the same means as the conventional fiber-blended fine particles, relatively large fine particles having a size of more than 1 μm are easily mixed in a large amount in the resin composition. It was more difficult to improve such troubles.

Therefore, Japanese Patent Publication No. 1-164721 proposes a method for producing zeolite having antibacterial properties from zeolite powder synthesized in a specific solvent and having a particle size of 10 μm or less. Describes a method of kneading a resin into a resin to form a fiber or the like. However, it is difficult to reduce the size of the zeolite particles to a sufficient degree even if the size of the zeolite particles is reduced by a crushing process using a machine or the like.
Further, the antibacterial zeolite carrying metal ions, since the whiteness of the zeolite particles themselves will be reduced by mechanically forcibly pulverizing and refining, there is a problem that the color tone of the resin blended deteriorates, Not the preferred method.

Further, in Japanese Patent Publication No. 1-15314,
A method of synthesizing A-type zeolite particles having a maximum particle size adjusted to 0.4 μm or less in advance and supporting antibacterial metal ions on the particles to produce zeolite having antibacterial properties has been proposed. However, since the particle size of zeolite is too small, it is difficult to isolate the zeolite particles from the reaction system after the zeolite synthesis while maintaining the dispersibility. In addition, zeolites with a small silica / alumina molar ratio, such as A-type zeolite, have the drawbacks of low thermal stability and easy aggregation, so when supporting antibacterial metal ions or kneading into resin, However, there is a problem in that stable fine zeolite particles are difficult to obtain due to secondary aggregation. Further, the A-type zeolite has a drawback that the metal ions supported on the surface are unstable and easily discolor, and this tendency becomes more remarkable as the atomization progresses, so it is difficult to sufficiently improve the deterioration of the color tone of the resin. Met.

In order to improve whiteness and particle dispersibility at the same time, a resin composition in which zeolite particles having antibacterial properties are blended by improving the cohesiveness by setting a high silica / alumina molar ratio Has been proposed (Japanese Patent Laid-Open No. 3-205436). According to this, although the whiteness and the cohesiveness can be improved to some extent, the improvement of the fine particles is not sufficient. Therefore, when the compounding amount of the zeolite particles is increased or when the molded product is continuously manufactured, a sufficient improving effect is not observed, and it is required to further improve the moldability as well as the color tone.

[0008]

Therefore, the present invention solves the above problems that could not be solved by the prior art, is excellent in antibacterial property and color tone, and is capable of excellent continuous molding. The main purpose is to provide a polyamide composition.

At the same time, the wear of the device when passing through the process is small,
It is another object to provide an antibacterial nylon fiber which is excellent in whiteness and strength / elongation property and is also excellent in high-order processability such as spinning, false twisting, knitting or weaving by a usual method.

[0010]

In order to achieve this object, the present inventors have improved the dispersibility of particles by using a zeolite having a specified composition and structure, and
By improving the method of miniaturization, it is possible to achieve a sufficiently fine particle size distribution while maintaining the whiteness of the antibacterial zeolite particles, further by blending this with a polyamide to produce an antibacterial polyamide composition, It has been found that the color tone and moldability can be sufficiently improved.

Further, when the antibacterial polyamide and the polyamide not containing the zeolite are mixed and melt-spun, the abrasion of the ceramic guide and the like is greatly improved, and the whiteness of the antibacterial nylon fiber is It has been found that the strength and elongation characteristics and the high-order workability can be improved.

That is, the antibacterial polyamide composition of the present invention is a polyamide composition containing 2 to 40% by weight of zeolite particles carrying 5 to 15% by weight of silver ions, based on the total weight of the composition. The particles are high silica mordenite, the number average particle diameter of which is 0.1 μm or more, and the proportion of particles having a particle diameter of more than 1 μm is 20.
It is characterized by being less than or equal to wt%.

In this antibacterial polyamide composition, zeolite particles carrying 5 to 15% by weight of silver ions are mixed with the polyamide polymerization raw material substantially before the completion of the polymerization, and the zeolite particles are added to the total weight of the composition. Is 2 to
A method for producing an antibacterial polyamide composition having a content of 40% by weight, wherein the zeolite particles are supported with silver ions, and then washed, finely processed into a slurry, and then filtered to obtain a particle diameter. It is produced by using zeolite particles obtained by removing particles exceeding 1 μm to 20% by weight or less.

Furthermore, in the antibacterial polyamide fiber of the present invention, the concentration of the zeolite particles is adjusted by mixing the antibacterial polyamide composition with a polyamide not containing the zeolite particles, and then melt spinning is performed. The antibacterial zeolite particles are obtained by substituting part or all of the ion-exchangeable sites of zeolite with silver ions.

It is also possible to use a composite type antibacterial zeolite which simultaneously supports other metal ions such as copper and zinc together with silver ions, but the total weight is 5 to 15
% Is preferably silver ions having high antibacterial activity. 5
If it is less than 10% by weight, it is difficult to obtain high antibacterial properties, so that it is necessary to increase the amount of zeolite particles to be mixed with the resin, and the original characteristics of the resin are likely to be impaired. On the other hand, if it exceeds 15% by weight, silver ions that are close to the saturated amount are supported, and thus the antibacterial zeolite is likely to be discolored and it is difficult to improve the color tone.

A generally known method can be applied to support silver ions on the zeolite particles. For example, a method using ion exchange, a method using a volatile carbonyl complex, or the like may be used, and among them, the method using ion exchange is preferable.

Although many kinds of zeolites having different compositions and structures are known to be used as a carrier for such silver ions, the zeolite used in the present invention has a high composition ratio of silica to alumina and is a mordenite type zeolite. High-silka mordenites belonging to the category of are suitable. Among them, those having a silica / alumina molar ratio in the range of more than 14 and less than 25 are preferable.

If the molar ratio of silica / alumina is too small, the ionicity of the zeolite surface becomes strong. Therefore, the zeolite particles are easily discolored, the color tone of the obtained product is lowered when it is blended into the composition or the composition, or when the composition is melt-molded, and it becomes difficult to perform the intended toning. . Furthermore, the dispersibility of the zeolite particles decreases, making it difficult to adjust the particle size. On the other hand, if the silica / alumina molar ratio is too high, the ability to support silver ions decreases, so in order to obtain a sufficient antibacterial effect, it is necessary to excessively mix the zeolite particles. The physical properties of may be impaired.

Further, mordenite type zeolite is easily disintegrated because it is less likely to be discolored or aggregated as compared with other zeolites due to the characteristics such as anisotropy of crystal structure, large pore size in network structure, and relatively high density. Further, it is preferable because the ceramic guide is less likely to wear when it is mixed with a resin to form a fiber or the like.

Such high-silica mordenite may be synthesized and used, or may be used by adjusting the silica / alumina molar ratio of naturally occurring mordenite by a method such as dealumination.

Since such synthetic or natural zeolite usually contains a large number of coarse particles of several μm or more, it is used in a finely divided form. The zeolite particles according to the present invention have a particle distribution within the above-mentioned specific range. It is necessary to.

First of all, it is necessary to use those having a number average particle diameter adjusted to 0.1 μm or more, especially 0.2 μm or more. A small particle size is preferable for improving moldability and preventing guide wear, but if the particle size is too small, the supported silver ions are likely to be released and the activity of the particle surface increases, causing discoloration. Is not appropriate.

Further, it is necessary that the content of particles having a particle diameter of more than 1 μm is 20% by weight or less, preferably 15% by weight or less, based on the total weight of the zeolite particles. That is, when a large amount of zeolite particles having a particle diameter of more than 1 μm is mixed with the resin, it causes various problems in production. For example,
When the fiber is molded, it is deposited on the filter part of the spinning pack,
This causes a rapid rise in filtration pressure. Further, since many zeolite particles having a particle diameter of more than 1 μm are present on the surface of a molded product such as a fiber or a film, the molded product is likely to be worn away easily in the device portion where the molded product comes into contact with each other, so that the molded product can be continuously manufactured. It will be difficult.

As described above, the composition of the present invention has the desired color tone and moldability by keeping the particle size of the zeolite particles above a certain size and reducing the amount of particles exceeding 1 μm. Obtainable.

As a method for adjusting the particle size of the antibacterial zeolite particles, an appropriate method can be adopted depending on the kind of zeolite and the method of blending with the resin. Among them, the method of making the zeolite particles fine in the form of a slurry in which they are dispersed in a liquid is preferable because the particles can be easily handled. In particular, when blended with polyamide, if treated as a water slurry,
It is preferable because it can be added as it is at the time of polymerization. At this time, the concentration of the slurry may be slightly lower, such as 5 to 40% by weight of zeolite, preferably 10 to 30% by weight. If the concentration is too high, the particles may be insufficiently dispersed.

Since the antibacterial zeolite has a low specific gravity, it is generally difficult to be made finer, and particles are crushed to form a large number of active surfaces. Therefore,
In order to minimize the discoloration of the particles, in order to suppress discoloration as much as possible, washing treatment with water or a weak acid in advance to wash silver ions on the surface, gently pulverizing it into a slurry, and then roughly classifying it, number average A method is preferred in which the particle size distribution is adjusted so that the particle size is 1 to 2 μm or less, and then particles having a particle size of more than 1 μm are separated and removed. A general method represented by a hammer mill or a ball mill can be applied to the crushing treatment. The classification treatment may be carried out by a method such as natural sedimentation or centrifugal classification. Further, if the slurry after the classification is subjected to a filtration treatment to sufficiently remove particles exceeding 1 μm, the ratio can be adjusted to 20% by weight or less. As a method of filtering, for example, the slurry may be passed through a fine filter as it is. Moreover, such filtration is 1
A step may be used, or a multi-step process in which the eyes are gradually made finer may be used.

The above-mentioned zeolite particles of the present invention can be blended with various polymers such as polyamide, polyester, and polyolefin, but in particular, there is little discoloration, addition at the time of polymerization is easy, and a composition having good dispersibility can be obtained. Therefore, polyamide is preferable. Specific examples thereof include nylon 4, nylon 6, nylon 12, nylon 66, nylon 610, and copolymers thereof, but are not particularly limited as long as they can be molded.

The content of the antibacterial zeolite in the polyamide is generally 2 to 40% by weight, and the amount of silver ions supported on the antibacterial zeolite, the kind of polyamide, the method of using the composition, and The optimum amount may be set depending on the intended use of the molded product. For example, when the concentration is adjusted by mixing with a polyamide containing no antibacterial zeolite, the amount may be slightly higher, such as 8 to 40% by weight, and particularly preferably 8 to 20% by weight. If this blending amount is too large, the dispersibility of the particles will be reduced and molding of the composition will be difficult, which is not practical.

The method for incorporating the zeolite particles into the polymer is as follows:
The optimum method may be selected depending on the type and blending amount of the polymer, but in particular, it is a step before the completion of the polymerization, which is a substantial polymerization step of the polymer, such as at the time of blending the raw materials before the polymerization of the polymer or during the polymerization. Is preferable in order to obtain uniform dispersibility.

The antibacterial polyamide composition of the present invention may be molded into various forms such as fibers, films, plates, containers and granules by a conventional method to produce an antibacterial molded article. At that time, the composition contains the antibacterial zeolite particles in a high concentration, and before the molding, if the concentration of the antibacterial zeolite is adjusted by mixing with another polyamide containing no antibacterial zeolite, The moldability of the obtained antibacterial polyamide molded product can be further improved. The amount of the antibacterial zeolite contained in the molded product by adjusting the concentration is 0.01 to 20% by weight, preferably 0.05 to 15% by weight, based on the molded product.

Since the obtained antibacterial polyamide composition has good moldability, it can be used in various applications.
In particular, it has a great effect of improving the wear of the device parts such as guides, and can further improve the high-order processability such as spinning, false twisting, knitting or weaving to reach the final product. It is suitable. In this case, it is more preferable for a yarn having a single yarn fineness, and especially 5d.
The following is preferable, and particularly 4d or less is preferable because a large effect can be exhibited.

Further, according to the present invention, the antibacterial polyamide fiber may be formed by a commonly used method, and the method can be selected according to the intended use and purpose. Among them, it is suitable when the discharge amount per die is large or when the winding speed is high. Particularly, when the spinning speed is 3500 m / min or more, a very high effect is exhibited.

The antibacterial nylon fiber obtained by the present invention is suitable for clothing such as pantyhose, tights, socks and lingerie, shoe lining, chair lining, carpet, etc., and various other uses. Can be used.

Further, if necessary, additives such as a color improving agent, a matting agent, a heat-resistant agent, a light-proofing agent, a dispersant and an antistatic agent may be simultaneously added to the resin composition, or added at the time of molding. You can also do it.

[0035]

EXAMPLES The present invention will now be described in more detail with reference to examples.

Examples 1 and 2 and Comparative Examples 1, 2 and 3 High silica mordenite (silica / alumina molar ratio 1
6) is treated with an aqueous solution of silver nitrate to obtain 9.5 wt% of silver ions.
A mordenite-type antibacterial zeolite containing was obtained. After thoroughly washing this antibacterial zeolite with water,
The mixture was dispersed in water with stirring so that the weight% of the mixture became a water slurry.

The water slurry was filled with glass beads having a particle diameter of 2 mm and passed through a sand grinder [made by AIMEX Co., Ltd.] adjusted to a spindle speed of 530 rpm once to pulverize gently. Next, the pulverized water slurry was allowed to stand for 20 days to allow coarse particles to settle and be classified. Further, the classified water slurry was filtered through a 5 μ or 10 μ sintered filter, respectively (Examples 1 and 2). A non-filtered water slurry was used for comparison (Comparative Example 1).

Further, as a comparison, the same mordenite-antibacterial zeolite water slurry as in the above example was placed in a sand grinder adjusted to a spindle speed of 1580 rpm.
It was circulated and crushed, and then left standing for 20 days for classification. In addition, the filtration by the sintering filter was not performed (Comparative Example 2).

Further, A-type zeolite (silica / alumina molar ratio: 1.9) was treated with an aqueous silver nitrate solution to obtain an A-type antibacterial zeolite containing 2.4% by weight of silver ion. Further, the powder was pulverized and classified in the same manner as in Example 1 except that filtration with a sintered filter was not performed (Comparative Example 3).

The whiteness of the antibacterial zeolite particles prepared by each method was visually observed. In addition, the particle size distribution is measured by a light transmission type particle size distribution analyzer (SKA50 manufactured by Seishin Industry Co., Ltd.)
0) was used. The results are shown in Table 1.

[0041]

[Table 1]

Next, 5% by weight (No. 1) of zeolite particles whose particle size was adjusted by the method of Example 2 was added to 85% by weight of an aqueous ε-caprolactam solution based on the solid content, and the particle size was adjusted by the method of Example 1. 10% by weight (No. 2) or 20% by weight (No. 3) of the prepared zeolite particles, and 10% by weight (No. 4, 5, 6) of the antibacterial zeolites of Comparative Examples 1, 2 and 3 respectively for comparison. ) Was adjusted so that

No. Each of the aqueous solutions of ε-caprolactam of 1 to 6 was pressure-polymerized in the usual manner into chips to obtain antibacterial nylon 6 chips containing antibacterial zeolite at a high concentration. The 98% sulfuric acid relative viscosity (ηr) of the obtained high-concentration antibacterial chip is shown in Table 2.

[0044]

[Table 2]

[Embodiment 3] No. High-concentration antibacterial chips 1 to 6 and ordinary nylon 6 chips containing no antibacterial zeolite were sufficiently mixed in the proportions shown in Table 3. Further, cuprous iodide and potassium iodide as auxiliary agents were mixed in an amount of 0.05% by weight with respect to the mixed chips, and then melt-spun at a winding speed of 4000 m / min by a conventional method to obtain 70 denier,
A 24-filament antibacterial nylon 6 filament yarn was wound into a drum shape, and the spinnability was evaluated from the increase of filtration pressure, yarn breakage and abrasion of the alumina ceramic guide (each level: 5 kg roll × 40 yarns).

Further, as a comparison, the same amount of filament yarn was wound into a drum shape in the same manner as above from only ordinary nylon 6 chips containing no antibacterial zeolite or the like (No. 7).

The surface whiteness of the obtained drum was measured with a color meter (Corre Mesuri manufactured by Nippon Denshoku Industries Co., Ltd.).
NG SYSTEM).

Further, the obtained yarn was false twisted by a usual method using a spindle system, and the workability was evaluated from the ratio of the drum where yarn breakage occurred.

Further, these filament yarns were made into a tubular knitted fabric by a conventional method, and antibacterial properties were evaluated by the following shake flask method.

Evaluation of antibacterial property: A suspension buffer of a test bacterium (Staphylococcus aureus) was added to a sample cloth, and it was placed in a closed container for 15 minutes.
The viable cell count is measured after shaking 0 times / min for 1 hour, and the difference in reduction rate (%) with respect to the bacterial count of the added suspension is determined.

[0051]

[Table 3]

As shown in Table 3, a comparative example (No. 5) using antibacterial zeolite particles with insufficient particle size adjustment and low whiteness was used.
4, 5 and 6), when using the antibacterial tip according to the present invention (Nos. 1 to 3), even when high-speed spinning is performed by increasing the particle concentration in the fiber, the filtration pressure during spinning is increased. Guide wear was greatly reduced, and yarn breakage was also extremely small. Moreover, the obtained antibacterial fiber was excellent in physical properties, whiteness and antibacterial property, and the false twisting processability was almost the same as in the case where the antibacterial chip was not added (No. 7).

When no antibacterial chip is added (N
o. Of course, 7) could not obtain antibacterial properties.

[0054]

According to the present invention, the following effects can be obtained.

The antibacterial nylon composition prepared by blending the antibacterial zeolite carrying silver ions can remarkably improve the moldability without deteriorating the antibacterial property and the color tone.

Above all, it is important that both whiteness and moldability are good, and it is particularly useful as an antibacterial fiber which is required to have a high-order passage property. For example, clothes such as lingerie and underwear. It is suitable for clothing, stockings, socks such as tights and socks, and upholstery such as carpets. In addition, antibacterial film, plate, container,
It is also useful for various purposes such as granular materials.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location D01F 6/60 301 G 6/90 301

Claims (8)

[Claims] 1. A polyamide composition containing 2 to 40% by weight, based on the total weight of the composition, of zeolite particles supporting 5 to 15% by weight of silver ions, wherein the zeolite particles are high silica mordenite. An antibacterial polyamide composition having a number average particle diameter of 0.1 μm or more and a proportion of particles having a particle diameter of more than 1 μm of 20% by weight or less. 2. The antibacterial polyamide composition according to claim 1, wherein the silica / alumina molar ratio (R) of the high-silica mordenite is 14 <R <25. 3. The number average particle diameter of the zeolite particles is 0.
The ratio of particles having a particle size of 2 μm or more and a particle size of 1 μm or more is 15% by weight or less.
The antibacterial polyamide composition described. 4. The antibacterial polyamide composition according to claim 1, wherein the ratio of the zeolite particles to the total weight of the composition is 8 to 20% by weight. 5. Zeolite particles carrying 5 to 15% by weight of silver ions are mixed with a polyamide polymerization raw material substantially before the completion of the polymerization so that the ratio of the zeolite particles to the total weight of the composition is 2 to 40% by weight. In the method for producing an antibacterial polyamide composition, the zeolite particles are supported by silver ions, and then washed, finely processed in the form of a slurry, and then filtered to obtain particles having a particle size of more than 1 μm. Is a zeolite particle obtained by removing up to 20% by weight. A method for producing an antibacterial polyamide composition, comprising: 6. The method for producing an antibacterial polyamide composition according to claim 5, wherein high silica mordenite particles having a silica / alumina molar ratio (R) of 14 <R <25 are used as the zeolite particles. 7. An antibacterial polyamide fiber is produced by adjusting the concentration of zeolite particles by mixing the antibacterial polyamide composition according to claim 1 and a polyamide containing no zeolite particles, and then melt-spinning. A method for producing an antibacterial polyamide fiber characterized. 8. The method for producing an antibacterial polyamide fiber according to claim 7, wherein the antibacterial fiber having a single yarn of 5d or less is spun by high-speed spinning at a winding speed of 3500 m / min or more.