JP2009108436A - Antimicrobial polyester conjugated fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent antimicrobial polyester conjugated fiber which does not cause an environmental problem, has the excellent antimicrobial property, and is not discolored with time, and to provide a method for producing the antimicrobial polyester conjugated fiber excellent in spinning stability. <P>SOLUTION: This polyester sheath-core type conjugated fiber having a sheath component/core component ratio of 10/90 to 80/20 is characterized in that the sheath component contains an inorganic antimicrobial agent carrying an antibacterial metal component which is at least partially silver component, and a silver component average content and a zinc content in the polyester conjugated fiber are 20-150 ppm and ≤10 ppm, respectively, and a coefficient of fiber-fiber dynamic friction is 0.20-0.35. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyester composite fiber having excellent antibacterial properties. More specifically, the present invention relates to an excellent antibacterial polyester composite fiber that has no environmental problems and has excellent antibacterial properties and does not discolor over time, and a method for producing an antibacterial polyester composite fiber excellent in spinning stability. .

Polyester fibers have excellent mechanical properties, chemical properties, processability, and easy care properties, and are therefore widely used for clothing, bedding, interiors, industrial materials, and the like.
In recent years, in these fiber applications, there is an increasing demand for fibers imparted with antibacterial properties as one of comfort functions.
In general, as a method for imparting antibacterial properties to fibers, a method in which an aromatic halogen compound, an organic silicone quaternary ammonium salt, an organic nitrogen compound, or the like is attached to the fibers is employed. As a result, there was a problem with washing durability.
Many antibacterial polyester fibers are known in which inorganic antibacterial agents such as zeolite particles supporting silver, zinc, and copper ions are contained in the fibers for the purpose of improving washing durability (Patent Document 1). The mechanism by which the antibacterial polyester fiber containing an inorganic antibacterial agent exhibits antibacterial performance is presumed to be due to the dissolution of silver, zinc and copper ions present on the fiber surface and acting on bacteria.

Polyester fiber is inorganic in order to obtain the desired antibacterial performance because there is less ion migration from the inside of the fiber to the fiber surface and the antibacterial agent present on the fiber surface elutes into the bath during scouring and dyeing. It is necessary to make an antibacterial agent exist on the fiber surface by containing a large amount of the antibacterial agent in advance.
For this reason, it became clear that the antibacterial polyester fiber in which the inorganic antibacterial agent is contained in the fiber has the following problems.
There are the following problems in spinning and wear resistance.
In general, in the production of an inorganic antibacterial agent used for fiber applications, an antibacterial property is imparted by ion exchange after finely pulverizing zeolite to have an average particle size of 10 μm or less. When such an inorganic antibacterial agent having a large particle size is contained in the fiber, not only yarn breakage occurs during spinning or drawing of the fiber, but also a projection corresponding to the particle size of the antibacterial agent is generated on the polyester fiber surface. It was revealed that the presence of these protrusions significantly reduced the fiber-to-fiber friction coefficient, causing collapse of the package and pan, making stable winding difficult. Further, it has been clarified that when a protrusion corresponding to the particle diameter of the antibacterial agent is present on the fiber surface, there is a disadvantage that the abrasion resistance is remarkably lowered when the knitted fabric is formed.

If the particle size of the inorganic antibacterial agent is reduced, thread breakage during fiber production and troubles during post-processing are expected to decrease, but the average particle size of conventional inorganic antibacterial agents is about 5 μm to 2 μm. It was the limit. For this reason, thread breakage and winding stability problems during fiber production have not been solved, and in order to avoid these problems and produce stably, the ratio of the inorganic antibacterial agent contained in the fiber is reduced. It was necessary to do (patent document 2).
The color change with time has the following problems.
When silver ions are used as an inorganic antibacterial agent, silver ions are oxidized due to the effects of various processing agents used in fiber processing and the action of oxygen, atmospheric acid gases, ultraviolet rays, and moisture. There is a problem that the color changes to blackish brown over time. This phenomenon becomes more prominent as the concentration of the antibacterial agent contained in the fiber is higher.
As a measure for preventing discoloration of a fiber containing a silver-based inorganic antibacterial agent, a method of adding an azole compound not having a mercapto group to a spinning oil (Patent Document 3) or a method of adding a hindered phenol (Patent Document 4) However, if the silver concentration in the fiber is increased, there is a problem that the effect is insufficient, and the problem has not been solved.
As another method for suppressing discoloration over time, it is known that an inorganic antibacterial agent contains an equivalent amount or excess of zinc oxide to silver ions. It becomes an environmental problem described later.

Regarding environmental problems, there are the following problems.
In recent years, due to environmental considerations, regulations on wastewater discharged during fiber processing such as dyeing have become stricter, and in particular, reduction of zinc ions is required. In particular, since silver-based inorganic antibacterial agents contain a large amount of zinc oxide for the purpose of suppressing the color change with time, elution into a bath during scouring and dyeing is inevitable. Zinc oxide is known to have antibacterial performance and the effect of preventing discoloration over time. Therefore, when the inorganic antibacterial agent is non-zinc-based, the anti-discoloration effect is reduced, and in order to suppress discoloration, it is necessary to reduce the ratio of the inorganic antibacterial agent contained in the fiber. . For this reason, a decline in antibacterial performance cannot be denied. That is, it became clear that the use of non-zinc-based silver-based inorganic antibacterial agents is a trade-off between antibacterial performance and discoloration suppression.
Even at a high silver ion content ratio necessary to obtain sufficient antibacterial performance, it has been an extremely important issue to suppress discoloration over time without containing zinc oxide.
As described above, improving antibacterial performance, suppressing yarn-making properties, abrasion resistance, temporal discoloration, and solving environmental problems were conflicting issues.
Therefore, there is no environmental problem, antibacterial performance is not deteriorated by dyeing or repeated washing, and excellent antibacterial performance is achieved. Therefore, the advent of a manufacturing method has been strongly demanded.

Japanese Examined Patent Publication No. 63-054013 JP 2004-360091 A Japanese Patent No. 2849017 JP-A-8-325844

  The present invention provides an excellent antibacterial polyester composite fiber that has no environmental problems and has excellent antibacterial properties and does not discolor over time, and a method for producing an antibacterial polyester composite fiber excellent in spinning stability. With the goal.

In solving the above-mentioned problems, the present inventors set the particle distribution and content ratio of the inorganic antibacterial agent containing the silver component contained in the sheath component of the sheath-core type composite fiber within a specific range, and a fiber that reflects both of them. By using a polyester composite fiber with a dynamic coefficient of friction between fibers in a specific range, it is possible to maintain antibacterial properties and suppress discoloration over time without causing environmental problems. We found out what we could do and came to complete the invention.
More specifically, by setting the average particle size of the inorganic antibacterial agent to be contained in the sheath component to 0.1 to 1.0 μm, the fiber-to-fiber dynamic friction coefficient is set to a specific range, and the significant decrease thereof is suppressed. In addition, the present inventors have found that high antibacterial properties can be maintained with a very small content without containing zinc oxide, and that discoloration over time can be suppressed.

That is, the present invention is as follows.
(1) A polyester sheath-core composite fiber having a ratio of a sheath component to a core component of 10/90 to 80/20, wherein the sheath component is an inorganic material in which an antibacterial metal component at least part of which is a silver component is supported An antibacterial agent, the silver component average content in the polyester composite fiber is 20 to 150 ppm, the zinc content is 10 ppm or less, and the fiber-fiber dynamic friction coefficient is 0.20 to 0.35. An antibacterial polyester composite fiber characterized by being.
(2) The antibacterial polyester composite fiber according to (1), wherein the polyester sheath-core composite fiber has a silver component content in the sheath component of 40 to 300 ppm.
(3) The antibacterial polyester composite as described in (1) or (2), wherein the whiteness retention after 50 days is 70% or more and the antibacterial property by SEK method is 2.2 or more fiber.

(4) The antibacterial polyester fiber according to any one of (1) to (3), wherein a toughness variation in a yarn length direction is 12 (cN / dtex ·% ^0.5 ) or less.
(However, toughness = [strength] × [elongation] is ^0.5 , and the difference between the maximum value and the minimum value is defined as toughness fluctuation.)
(5) The antibacterial polyester composite fiber according to any one of (1) to (4), wherein the cross section of the single yarn is W-shaped and the flatness is 2 to 5.
(6) The antibacterial polyester according to any one of (1) to (5), wherein the polyester component is a polyester selected from at least one of polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. Composite fiber.
(7) A woven or knitted fabric using the antibacterial polyester conjugate fiber according to (1) to (6).

(8) In blending the polyester with an inorganic antibacterial agent carrying an antibacterial metal component at least a part of which is a silver component, the zinc component content is 10 ppm or less and the average particle size is 0.1 to 1. An inorganic antibacterial agent in which 0.5 to 2% by weight of an inorganic antibacterial agent having a particle diameter of 0 μm and a particle diameter of 1.2 μm or more is 20% by weight or less is mixed with the polyester component as a sheath component. The antibacterial property according to (1), wherein a polyester component not containing an antibacterial agent is used as a core component, and the ratio of the sheath component to the core component is fiberized as a sheath core type composite fiber having a ratio of 10/90 to 80/20. A method for producing a polyester composite fiber.
(9) The method for producing an antibacterial polyester composite fiber according to (8), wherein a master pellet and a polyester pellet having an inorganic antibacterial content of 5 to 30% by weight are melt-mixed.

  According to the present invention, it is possible to make the zinc content as extremely small as 10 ppm or less, there is no environmental problem, the antibacterial performance is not deteriorated even by dyeing and the like, and excellent antibacterial properties are exhibited, and the wear resistance is excellent. There is an effect that it is possible to provide an antibacterial polyester composite fiber having no discoloration with time and a method for stably producing the same.

The present invention will be described in detail below.
The present invention relates to a polyester sheath / core composite fiber having a sheath / core ratio of 10/90 to 80/20, wherein the sheath component is an inorganic system in which an antibacterial metal component at least part of which is a silver component is supported. Contains antibacterial agents. The preferred range of the ratio of the sheath component to the core component is 20/80 to 70/30, particularly preferably 30/70 to 60/40.
In the present invention, the advantage of the sheath-core composite fiber is that the antibacterial performance is strongly influenced by the silver component content of the sheath component, while the color change with time is strongly influenced by the average content of the silver component in the composite fiber. This is a new discovery that makes it possible to simultaneously solve the conflicting purposes of antibacterial performance and suppression of discoloration over time. Compared to a single fiber, the average content of the inorganic antibacterial agent can be reduced, which is also advantageous from the viewpoint of cost reduction. Further, when the average content is equal to that of a single fiber, there are advantages such as high whiteness and whiteness retention, high strength, and small toughness fluctuation.

The inorganic antibacterial agent contained in the sheath component of the present invention is an inorganic antibacterial agent carrying an antibacterial metal component, at least a part of which is a silver component. Examples of the inorganic compound that supports the silver component include the following.
That is, inorganic adsorbents such as activated carbon, activated alumina, silica gel, zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, potassium titanate, hydrous antimony, hydrous bismuth, hydrous zirconium, hydrous titanium and hydrotalcite Inorganic ion exchangers such as
In particular, an antibacterial agent in which a silver component is supported on zeolite has excellent silver component supportability, has excellent antibacterial performance stability and durability, and has the advantage of less discoloration when kneaded into polyester. Therefore, it is preferable.

There are no particular limitations on the method of supporting silver in the present invention on these inorganic compounds. For example, a method of supporting by physical adsorption or chemical adsorption, a method of supporting by ion exchange reaction, a method of supporting by a binder, a metal compound There are a method of supporting by injecting into an inorganic compound, a method of supporting by forming a thin layer of a metal compound on the surface of the inorganic compound by a thin film forming method such as vapor deposition, dissolution precipitation reaction, and sputtering.
Further, in the antibacterial agent in which a silver component is supported on zeolite, a dispersant or a concealing agent is preferably used in combination for the purpose of preventing aggregation of the antibacterial agent and suppressing excessive ion elution of silver ions. Further, the antibacterial agent preferably contains a phosphate compound or an alkaline earth metal oxide as a discoloration preventing stabilizer.

In the present invention, it is important to control the silver concentration in the sheath component of the polyester composite fiber from the viewpoint of stability of antibacterial performance and suppression of discoloration over time, and the silver component content in the sheath component of the polyester composite fiber is 40 to 300 ppm is preferred. When the silver component content in the sheath component is less than 40 ppm, discoloration with time is suppressed, but the washing durability of antibacterial performance decreases. When the silver component content exceeds 300 ppm, the washing durability of antibacterial performance is improved, but the color change with time increases. The preferable silver component concentration contained in the sheath component of the polyester composite fiber is 50 to 200 ppm, more preferably 60 to 150 ppm.
The polyester composite fiber of the present invention needs to have an average silver component content of 20 to 150 ppm in the polyester composite fiber. When the average content of the silver component is less than 20 ppm, the washing durability of the antibacterial performance decreases. When the average content of the silver component exceeds 150 ppm, the antibacterial washing durability is improved, but the color change with time increases. The average content of the silver component contained in the polyester composite fiber is preferably 30 to 100 ppm, more preferably 40 to 80 ppm.

In general, when the content of the silver component is increased in order to enhance antibacterial properties, discoloration with time tends to occur, and the antibacterial property maintenance and the effect of suppressing discoloration with time have a trade-off relationship. Therefore, a compound such as zinc is used as the anti-discoloring agent, and as a result, environmental problems are likely to occur.
The present invention solves this problem, and even if the zinc content is as low as 10 ppm or less, the antibacterial property of SEK value is 2.2 or more and the whiteness retention is 70% or more. The present inventors have found a polyester composite fiber that can improve the effect of suppressing discoloration over time without impairing performance.
FIG. 1 shows the relationship between the silver component and antibacterial properties in the present invention. As shown in FIG. 1, the antibacterial property is remarkable when the average content of the silver component is 20 ppm or more, and the antibacterial property by the SEK method is 2.2 or more when the silver component content is in the range of 20 to 150 ppm. Thus, in the present invention, the silver component exhibits remarkable antibacterial properties in a low concentration range.
On the other hand, although the whiteness retention rate tends to decrease as the silver component content increases, the whiteness retention rate can be maintained at 70% when the silver component content is in the range of 20 to 150 ppm, and the color change over time is excellent. Has the effect of suppressing

The antibacterial polyester composite fiber of the present invention needs to have a zinc content of 10 ppm or less.
If the zinc content is 10 ppm or less, even if a part of the antibacterial agent is eluted from the fiber surface into the bath, the zinc concentration in the bath is extremely low and there is no environmental impact. The zinc content is preferably none at all.
The antibacterial polyester composite fiber of the present invention needs to have a fiber-fiber dynamic friction coefficient (hereinafter referred to as F / F dynamic friction coefficient) of 0.20 to 0.35.
The F / F dynamic friction coefficient generally varies depending on the choice of finishing agent and the like, but the influence of the inorganic antibacterial agent contained in the antibacterial polyester composite fiber forming minute protrusions on the fiber surface is large. That is, it has been clarified for the first time by the present inventors that it is strongly influenced by the particle size distribution and content of the inorganic antibacterial agent.

As will be described later, the F / F dynamic friction coefficient is set by the average particle diameter and content of the inorganic antibacterial agent contained in the fiber.
When the F / F dynamic friction coefficient is less than 0.2, a large number of inorganic antibacterial agents with large particle diameters are projected on the fiber surface, and although antibacterial performance is excellent, discoloration with time is large, and yarn breakage or winding during fiber production A shape abnormality occurs and stable manufacturing becomes difficult. When the F / F dynamic friction coefficient exceeds 0.35, there is almost no inorganic antibacterial agent on the fiber surface, the wound shape during fiber production becomes normal, and discoloration with time is suppressed, but the antibacterial performance is insufficient.
When the F / F dynamic friction coefficient is within the range of the present invention, fiber production can be stably performed, and at the same time, discoloration with time is suppressed, and excellent antibacterial performance is exhibited.
A preferable F / F dynamic friction coefficient is 0.22 to 0.30.

The antibacterial polyester composite fiber of the present invention preferably has a whiteness retention rate of 70% or more by a whiteness retention test described later. The higher the whiteness, the less the color change with time. If the whiteness retention is 70% or more, it can be used practically in dyed knitted fabrics. When the whiteness is 75% or more, when the antibacterial polyester composite fiber and other fibers are knitted and woven, the color change with time is hardly a problem. A more preferable whiteness retention is 80% or more.
Antibacterial polyester fiber of the present invention, yarn length direction of the toughness variation, is preferably ^{12 (cN / dtex ·% 0.5} ) or less. However, toughness is measured by the method described later.

Furthermore, when the polyester composite fiber contains a large amount of an inorganic antibacterial agent having a large particle size of several microns or more, the toughness of the polyester fiber periodically varies in the yarn length direction. It became clear by examination. The reason for this is not clear, but since it is difficult to completely mix the inorganic antibacterial agent, it is presumed that the uneven content of the inorganic antibacterial agent causes toughness spots. In the present invention, the control of the particle size of the inorganic antibacterial agent and the method of dispersing in the fiber based on the production method described later have been found, thereby making it possible to reduce the toughness fluctuation in the yarn length direction of the fiber. . The toughness variation in the yarn length direction is preferably 10 (cN / dtex ·% ^0.5 ) or less, and more preferably 8 (cN / dtex ·% ^0.5 ) or less.

The polyester referred to in the present invention refers to a fiber-forming polyester such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. More generally, polyethylene terephthalate is used. These polyesters are copolymerized with dicarboxylic acid components such as isophthalic acid, naphthalenedicarboxylic acid, and adipic acid, and diol components such as propylene glycol, butanediol, cyclohexane-1,4-dimethanol, and polyethylene glycol. May be. Further, it may contain additives such as a matting agent, an antistatic agent, and a stabilizer.
The cross-sectional shape of the single yarn of the fiber is not particularly limited, but W, Y, I, X-shape, etc. are adopted in addition to the round cross section. In particular, when the single yarn cross-sectional shape is W-shaped and the flatness (the ratio of the length of the short side to the long side of the circumscribed rectangle) is 2 to 5, it is easy to set the F / F dynamic friction coefficient within the range of the present invention. It is preferable. Further, in order to impart water absorption to the polyester composite fiber having a W-shaped cross section by utilizing capillary action in addition to antibacterial performance, the flatness of the single yarn is preferably 2.0 to 4.0.

Moreover, in order to stabilize antibacterial performance and water absorption performance, the cross-sectional shape of the single yarn is preferably W-shaped, and the opening angle of each recess is preferably 100 to 150 degrees. As a result, the cross-sectional shape of the single yarn becomes a W-shaped cross-section having water absorption, and a polyester composite fiber having excellent antibacterial performance with a small amount of antibacterial agent and a soft texture can be obtained.
The antibacterial polyester composite fiber of the present invention may be used in a knitted fabric as a long fiber, or may be mixed with other fibers as a short fiber.
Hereinafter, the manufacturing method of the antimicrobial polyester composite fiber of this invention is demonstrated.
In the production of the antibacterial polyester composite fiber of the present invention, a known composite spinning machine is employed.

As a method for blending the inorganic antibacterial agent, which is a sheath component, into the polyester, there is a method in which the inorganic antibacterial agent is dispersed and added to ethylene glycol or the like at the time of polyester polymerization, chipped after polymerization is completed, and melt spinning. In addition, there are a method in which an inorganic antibacterial agent is directly kneaded into a polyester chip and melt spinning, a method in which a master chip is formed and the polyester and the polyester chip are mixed, and then spinning is performed. When an inorganic antibacterial agent containing a silver component is added at the time of polymerization, the silver component is discolored by a catalyst or additive used at the time of polyester polymerization, and the color of the polymer is deteriorated. In addition, the inorganic antibacterial agent is directly kneaded into the polyester chip and melt-spun, so that the inorganic particles are not sufficiently dispersed in the polyester, and defects such as an increase in spinning filter pressure and yarn breakage become obvious. Become.
On the other hand, the method of kneading the inorganic antibacterial agent with the master chip is not only kneading into the polyester at the stage of becoming the master chip, but further kneading with the polyester in the spinning process, and the inorganic system into the polyester in two stages. Since the kneading of the particles is performed, the fine dispersion of the inorganic particles is superior to other methods. In addition, since the kneading time is short, there is little change in the color tone of the polyester, and a fiber with good color tone and level dyeing can be obtained. Therefore, it can be said that the kneading method using a master chip is the most preferable method from the viewpoint of stability such as physical properties, color tone, and productivity of the polyester composite fiber.

The concentration of the inorganic antibacterial agent in the master chip used in the present invention is 5 to 30% by weight, preferably 10 to 20% by weight. If it exceeds 30% by weight, the dispersibility of the inorganic particles is insufficient, and if it is less than 5% by weight, the efficiency decreases, which is not preferable.
In the present invention, when an inorganic antibacterial agent carrying an antibacterial metal component, at least a part of which is a silver component, is blended with polyester, the content of the zinc component in the inorganic antibacterial agent is 10 ppm or less. is necessary. By not containing a zinc component substantially in an inorganic type antibacterial agent, discharge | emission of the zinc component to the environment at the time of antibacterial polyester fiber processing can be avoided.
The inorganic antibacterial agent used in the production of the present invention is required to have an average particle size of 0.1 to 1.0 μm and a ratio of particles having a particle size of 1.2 μm or more to 20% by weight or less. .
The average particle diameter of the inorganic antibacterial agent is 0.1 to 1.0 μm in average particle diameter for the purpose of improving stability during spinning and winding stability, and further improving the abrasion resistance of the knitted fabric, and The ratio of the particle size of 1 μm or more needs to be 20% by weight or less.

If the average particle size of the inorganic antibacterial agent exceeds 1.0 μm, yarn breakage during spinning increases and stable production becomes difficult. In addition, the F / F dynamic friction coefficient of the polyester composite fiber is less than 0.20, and the fiber becomes very slippery. Therefore, the package and the pann are crushed, and stable winding becomes difficult. Furthermore, the wear resistance of the product knitted from the polyester composite fiber is lowered, and the merchantability is lowered. The average particle size of the inorganic antibacterial agent is preferably as small as possible. However, in the current technical level, it takes a great deal of cost to make it less than 0.1 μm, and therefore, 0.1 μm is the limit in the industry.
A preferable range of the average particle diameter of the inorganic antibacterial agent is 0.3 to 0.8 μm.
The inorganic antibacterial agent needs to have an average particle size of 0.1 to 1.0 μm and a ratio of particles having a particle size of 1.2 μm or more to 20% by weight or less.
When the ratio of particles having a particle diameter exceeding 1.2 μm exceeds 20% by weight, the yarn breakage, winding stability, and wear resistance are deteriorated. The ratio of particles exceeding 1.2 μm is preferably 10% by weight or less.

The compounding amount of the inorganic antibacterial agent in the sheath component needs to be 0.5 to 2% by weight with respect to the polyester component.
When the blending amount is 0.5% by weight or less, the silver component content in the sheath component of the polyester composite fiber needs to be 40 ppm. The thermal stability and discoloration stability of the antibacterial agent itself are poor.
When the blending amount exceeds 2% by weight, even if the average particle size of the inorganic antibacterial agent is decreased, the fiber-fiber dynamic friction coefficient becomes less than 0.2, and the fiber production stability and wear resistance become poor.
A preferable blending amount is 0.6 to 2% by weight, and more preferably 0.7 to 1.5% by weight.
The fiber formation of the antibacterial polyester composite fiber of the present invention is carried out by using a polyester containing an antibacterial agent as a sheath component, forming a sheath core type in a spinning pack with a sheath component and a core component in a predetermined ratio, and spinning from a spinning nozzle. After solidification, a two-stage method in which the film is once wound and stretched and heat treated, a one-stage method in which the film is continuously stretched and heat-treated without being wound once, or a high-speed spinning that is wound at a high speed to form a fiber is possible.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the measuring method of the characteristic value used by this invention is shown below.
(1) Flatness Flatness was calculated | required by ratio of the long side A and the short side B of a circumscribed rectangle in the single yarn cross section of a fiber by following Formula.
Flatness = long side A / short side B
(2) Fiber-to-fiber dynamic friction coefficient A fiber of 690 m was wound around a cylinder with a tension of about 15 g at a twill angle of 15 degrees and hung on a cylinder wound with the same fiber of 30.5 cm as described above. At this time, the fiber was hung so as to be perpendicular to the axis of the cylinder. A weight having a weight (g) which is 0.04 times the total denier of the fiber hung on the cylinder was tied to one end of the fiber hung on the cylinder, and a strain gauge was connected to the other end. Next, this cylinder is rotated at a peripheral speed of 18 m / min, and the tension is measured with a strain gauge. The fiber-fiber dynamic friction coefficient f was determined from the following equation from the tension thus measured.
f = 1 / π × ln (T2 / T1)
Here, T1 is the weight (g) of the weight applied to the fiber, T2 is the average tension (g) when measured at least 25 times, ln is the natural logarithm, and π is the circumference. The measurement was performed at 25 ° C.

(3) Antibacterial property evaluation It performed according to the unified test method of the textile product hygiene processing council (SEK). After sterilization, dry specimens (about 18 mm square test piece 0.4 g) were sterilized with high-pressure steam and ice-cooled in a 1/20 concentration nutrient broth. Inoculate 0.2 ml of the test bacteria suspension adjusted to 10 ⁵ cells / ml so that the entire specimen is uniformly immersed, and tighten a sterilized cap. This was cultured at 37 ± 1 ° C. for 18 hours, and the number of viable bacteria after the culture was measured.
There are two types of specimens: a standard cloth (a cloth specified in the processing effect evaluation test manual for antibacterial and deodorant processed products) and a processed cloth. As test bacteria, Staphylococcus aureus ATCC 6538P is used, and The bacteriostatic activity value, which is an antibacterial index, was calculated by this method.
Bacteriostatic activity value: LogB-LogC
However, the test establishment condition (LogB-LogA)> 1.5 shall be satisfied. A: Average number of bacteria recovered immediately after inoculation with standard cloth B: Average number of bacteria after 18 hours of culture of standard cloth C: Test Bacterial average value after 18 hours of culturing the cloth Bacteriostatic activity value of 2.2 or more was judged to be antibacterial.

(4) Abrasion resistance In the JIS-L-1096 Martindale abrasion method, the wear load was evaluated in five stages by applying a pressing load for clothing, and the abrasion cloth was worn 10,000 times using a blanket. The 5th grade shows little wear and excellent wear resistance, and the 1st grade shows poor wear resistance. Usually, if it is more than the third grade, it can be used practically.
(5) Whiteness and whiteness retention rate After scouring and drying the fabric under the following conditions, place the fabric in an environmental room with a temperature of 24 to 28 ° C and a humidity of 40 to 50% RH, on the south window where it is not exposed to direct sunlight. Using a spectrocolorimeter (manufactured by Gretagmacbeth, model Color-Eye7000A), the whiteness was measured from the Lab color system. The whiteness is higher as the numerical value is higher.
The value obtained by dividing the whiteness after 50 days by the whiteness immediately after scouring and drying was multiplied by 100 to obtain the whiteness retention.
Scouring conditions
Surfactant: Score roll FC-250 (Kitahiro Chemical Co., Ltd.) 2 g / liter
Sodium carbonate: 1 g / liter Bath ratio: 1:50
Treatment temperature, time: 80 ° C, 20 minutes
After completion of the treatment, washing with hot water and washing with water were performed, followed by dehydration and drying.
In this test, the higher the whiteness, the less the color change with time. If the whiteness is 70 or more, it is acceptable.

(6) Toughness fluctuation (unit: cN / dtex ·% ^0.5 )
Based on JIS-L-1013, the strength and elongation are measured 50 times every 0.5 m in the yarn length direction, the toughness is calculated by the following formula, and the difference between the maximum value and the minimum value is the toughness fluctuation. did.
Toughness = [strength] x [elongation] ^0.5
(7) Particle size distribution The particle size distribution of the inorganic antibacterial agent used was measured with a laser diffraction / scattering particle size distribution measuring device LA-920 manufactured by Horiba, Ltd.
As the measurement result, the particle size distribution is calculated by a computer incorporated in the measuring apparatus, and a histogram of the particle size and the existing ratio (volume) distribution frequency and the average particle size are displayed. The average particle size is read from this display. Further, the ratio (volume) of particles having a particle diameter exceeding 1.2 μm was read from the histogram.

(8) Winding stability 40 winding packages with a winding weight of 6 kg were collected for each condition by winding one spindle with 8 ends, and whether or not the winding package collapsed and whether there was a yarn drop defect on the side of the package. Was evaluated in three stages.
◎: Good without breakage and side thread drop defect ○: No roll breakage, but slight thread drop
X: There is a winding breakage or a remarkable thread dropping defect.
(9) Comprehensive evaluation ◎; All of yarn-making property, antibacterial property, abrasion resistance, discoloration with time, and zinc component elution amount are good.
○: All of the yarn-making property, antibacterial property, abrasion resistance, discoloration with time, and zinc component elution amount are almost good. ×: Any of the yarn-forming property, antibacterial property, abrasion resistance, discoloration with time, and zinc component elution amount is not good.
Good.

[Examples 1-5, Comparative Examples 1-2]
A known sheath-core type composite spinning machine was used, and the ratio of the sheath component to the core component was 50/50.
The sheath component contains 0.4% by weight of titanium oxide, polyethylene terephthalate having an intrinsic viscosity [η] of 0.60 (measured in orthochlorophenol at 1% by weight), and silver as an inorganic antibacterial agent A. The component is supported at 0.90% by weight, the average particle size is 0.5 μm, the ratio of particles having a particle size of 1.2 μm or more is 2% by weight, the zinc content is 1 ppm or less, and MgO, P2O3, TiO2 as anti-discoloration stabilizers. Master pellets containing 20% by weight of antibacterial zeolite (made by Fuji Chemical; trade name FK-68) containing sucrose and individually dried to make the chip moisture content 50% or less. (Matsui Seisakusho: Jet Color) was mixed so that the inorganic antibacterial agent had the content (% by weight) shown in Table 1, and a barrier type screw (Maddock type) was inserted. Feeded to the extruder. The chips mixed at a constant ratio were melted by an extruder, and then passed through a polymer pipe in which 10 elements of a Kenix static mixer were installed. Polyethylene terephthalate containing 0.4% by weight of titanium oxide and having an intrinsic viscosity [η] of 0.06 was supplied as the core component. Each of the sheath component and the core component is introduced into a spin pack having a filtration layer.

Extruded at a spinning temperature (spin head temperature) of 290 ° C from a nozzle with 30 spinning holes perforated in a W shape, cooled and solidified with cooling air, and then wound around a first stretching roll rotating at a take-up speed of 2000 m / min. After taking, the filament is heated to 100 ° C. with the drawing roll, the drawing heat setting is performed between the second drawing rolls at 130 ° C., the drawing is drawn so that the elongation becomes 30 to 40%, and the single yarn cross-sectional shape Was a W-shaped cross section, and 84 dtex / 30 filament drawn yarn containing an inorganic antibacterial agent in the sheath component was obtained. The winding was performed using AW-909 manufactured by Teijin Seiki Co., Ltd.
The single yarn cross section of the obtained polyester conjugate fiber had an opening angle of 130 degrees inside the recess and a flatness ratio of 3.3.
Next, each knitted yarn containing inorganic antibacterial agent and the raw yarn not containing inorganic antibacterial agent were smooth knitted under normal knitting conditions using a 22 gauge, 20 inch knitting machine. The basis weight of this knitted fabric was 98 g / m ² .

This knitted fabric was scoured at 80 ° C., pre-set at 190 ° C., and dyed under the following dyeing conditions. In addition, the dye density | concentration and the polyester resin density | concentration were made into the density | concentration with respect to the polyester composite fiber weight.
Dyeing conditions Dye: Nikka Bright 8720-V01S 1.0% omf
(Manufactured by Nikka)
Auxiliary agent: Nikka Sun Salt RM-340 (manufactured by Nikka Chemical Co., Ltd.)
0.5g / liter
Acetic acid: 0.5 cc / liter Sodium acetate: 1 g / liter Water-soluble polyester resin: SR-1000 (manufactured by Takamatsu Yushi Co., Ltd.) 3% omf
(Solid content 0.3%)
(Weight loss rate at 180 ° C .: 0.4%, carboxyl group content: 15 mol / t)
Bath ratio: 1:25
Dyeing temperature and time: 130 ° C., 30 minutes After dyeing was completed, washing with hot water and washing were performed, followed by dehydration and drying, and then finished with a dry heat set at 160 ° C. for 1 minute.
Table 1 shows the evaluation results of the antibacterial property, abrasion resistance, and whiteness change over time of the finished dyed product.
In Comparative Example 1, the content of the inorganic antibacterial agent was small and the antibacterial property was poor. In Comparative Example 2, since the content of the inorganic antibacterial agent was excessive, the F / F dynamic friction coefficient was outside the scope of the present invention, the yarn-making property was poor, and the whiteness retention rate was also poor.

[Examples 6 to 8, Comparative Example 3]
In the same manner as in Examples 1 to 5, inorganic antibacterial agents having different average particle diameters were added so that the content in the sheath component was 1.0% by weight (the average content of the silver component was 45 ppm).
Table 2 shows the evaluation results of antibacterial properties, abrasion resistance, and whiteness change over time of the finished dyed product.
Comparative Example 3 has an average particle size larger than that of the other examples. As a result, the F / F dynamic friction coefficient is outside the present invention, and the yarn-making property is poor, and the antibacterial property, wear resistance, and whiteness retention rate are also poor. Met.

[Comparative Examples 4 to 7]
In the same manner as in Examples 1 to 5, Comparative Examples 4 and 5 were supported with inorganic antibacterial agent B, zeolite with 0.6% by weight of silver component and 3.0% by weight of zinc component as discoloration inhibitor, Using master pellets containing 20% by weight of antibacterial zeolite (manufactured by Fuji Chemical; trade name FC-66) whose average particle size is 0.5 μm and the ratio of particles having a particle diameter of 1.2 μm or more is 7% by weight, The silver ion concentration was contained in the fiber as shown in Table 3. On the other hand, Comparative Examples 6 and 7 are inorganic antibacterial agent C, particles having 0.45% by weight of silver component and 19% by weight of zinc component supported on zeolite, and having average particle size of 2.0 μm and particle size of 1.2 μm or more. Using a master pellet containing 10% by weight of an antibacterial zeolite (Fuji Chemical; trade name FK-43) containing 72% by weight of silver, the silver ion concentration in the fiber is contained in the fiber as shown in Table 3 I let you.
Table 3 shows the evaluation results of the yarn-making property, antibacterial properties, abrasion resistance, and whiteness change with time of the finished mixed dyed product.
In Comparative Examples 4 and 5 using the inorganic antibacterial agent B, the yarn-forming property, antibacterial property, abrasion resistance, and whiteness change over time were good, but the zinc component was eluted in the dyeing solution during scouring and dyeing. .
In Comparative Example 6 using the inorganic antibacterial agent C, the yarn-making property, antibacterial performance and wear resistance were poor. In Comparative Example 7, the antibacterial performance was good, but the yarn-making property and wear resistance were poor.

  INDUSTRIAL APPLICABILITY The present invention can be used in a method for producing an excellent antibacterial polyester composite fiber having no environmental problems and excellent antibacterial properties and having no discoloration over time, and an antibacterial polyester composite fiber excellent in spinning stability.

The relationship between the silver component and antibacterial properties in the present invention is shown.

Claims (9)

  An inorganic antibacterial agent comprising a polyester sheath-core composite fiber having a ratio of a sheath component to a core component of 10/90 to 80/20, wherein the sheath component is loaded with an antibacterial metal component, at least a part of which is a silver component The average silver component content in the polyester composite fiber is 20 to 150 ppm, the zinc content is 10 ppm or less, and the dynamic friction coefficient between fibers and fibers is 0.20 to 0.35. Features antibacterial polyester composite fiber.   The antibacterial polyester composite fiber according to claim 1, wherein the polyester sheath-core composite fiber has a silver component content of 40 to 300 ppm in the sheath component.   The antibacterial polyester composite fiber according to claim 1 or 2, wherein the whiteness retention after holding for 50 days is 70% or more, and the antibacterial property by SEK method is 2.2 or more. The antibacterial polyester fiber according to any one of claims 1 to 3, wherein a toughness variation in a yarn length direction is 12 (cN / dtex ·% ^0.5 ) or less.
(However, toughness = [strength] × [elongation] is ^0.5 , and the difference between the maximum value and the minimum value is defined as toughness fluctuation.)   The antibacterial polyester composite fiber according to any one of claims 1 to 4, wherein the single yarn has a W-shaped cross section and a flatness of 2 to 5.   The antibacterial polyester composite fiber according to any one of claims 1 to 5, wherein the polyester component is a polyester selected from at least one of polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate.   A woven or knitted fabric using the antibacterial polyester composite fiber according to claim 1.   In blending the polyester with an inorganic antibacterial agent carrying an antibacterial metal component, at least a part of which is a silver component, the zinc component content is 10 ppm or less, the average particle size is 0.1 to 1.0 μm, In addition, an inorganic antibacterial agent having an inorganic antibacterial agent in which the ratio of particles having a particle diameter of 1.2 μm or more is 20% by weight or less mixed with 0.5 to 2% by weight of the polyester component is used as a sheath component. 2. The antibacterial polyester composite fiber according to claim 1, wherein the polyester component is contained as a core component, and the ratio of the sheath component to the core component is fiberized as a sheath core type composite fiber having a ratio of 10/90 to 80/20. Manufacturing method.   The method for producing an antibacterial polyester composite fiber according to claim 8, wherein a master pellet having a content of inorganic antibacterial agent of 5 to 30% by weight and a polyester pellet are melt-mixed.

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