JPH03213516A - Production of antimicrobial conjugate fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber, excellent in antimicrobial properties, durability, handleability, spinning properties, etc., by using a polymer having an antimicrobial substance applied thereto according to dry processing such as flame spraying as one component of conjugate fiber and carrying out melt conjugate spinning so as to expose the aforementioned component to the surface thereof. CONSTITUTION:An antimicrobial substance (preferably silver iodide, etc.) is applied to the surface of a polymer according to dry processing such as vacuum deposition, flame spraying, sputtering or ion plating and the resultant polymer is then used as one component of conjugate fiber to carry out melt conjugate spinning so as to expose at least part of the above-mentioned component to the surface of the fiber. Specifically, the antimicrobial agent is applied to the polymer chips by, e.g. a method for charging the polymer chips into a rotatable drum-shaped sample container placed in a vacuum and depositing the antimicrobial agent on the polymer chips in the vacuum while rotating the drum. Furthermore, the antimicrobial agent is preferably uniformly applied to the whole surface of the polymer to 0.01-1mum film thickness.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for producing antibacterial composite fibers.

More specifically, the present invention relates to a method for producing a novel antibacterial composite fiber using as one component a polymer having an antibacterial substance attached to its surface.

(Prior Art and Problems to be Solved by the Invention) As the standard of living and culture has improved, antibacterial fibers and their production have become of great interest even in institutions other than insurance and medical institutions.

The main methods of imparting antibacterial properties are: ■ A method of attaching antibacterial substances to the surface of fibers and textile products. For example, quaternary ammonium compounds, aromatic halogen compounds, thiabendazole, copper ions, silver ion compounds, etc. are attached to the surface of fibers and textile products by spraying, coating, pad-drying, etc. 5751874, JP-A-56-12347). With this method, it is difficult to ensure durability and effective ingredient concentration.

■ Microparticles and powders of antibacterial metals such as silver, copper, zinc, and tin and their compounds, coated with inorganic microparticles such as titanium oxide, or ions of these coated with inorganic crystals such as zeolite and montmolinite. 147220, Japanese Patent Application Laid-open No. 133235, Japanese Patent Application Laid-open No. 1-242665,
JP-A No. 1-242666 (@) This method is also widely practiced like method (2), but fine particles and powder tend to aggregate, making it difficult to blend uniformly with the polymer, and blending in large quantities can cause problems in spinning. There are quality problems such as problems during molding, uneven fiber fineness, and benosier. Until now, fibers made by blending metals and metal compounds into polymers have been used, but their antibacterial properties are not necessarily good. This is because when blending the antibacterial substance into the polymer and melt-spinning or melt-molding the polymer depth, the antibacterial substance is completely encapsulated in the polymer and the presence of antibacterial metal ions on the surface of the fibers. This seems to be because it is extremely small.

■ Mixed weaving and knitting of fine metal wires with antibacterial properties such as copper and silver. This method is the oldest method, but because the thin metal wires are large in thickness, crimped, and shaped differently from normal fibers, good blending, interweaving, and cross-knitting cannot be achieved, and the texture and dyeability may deteriorate, resulting in poor quality. There are major problems in terms of productivity and quality, such as the occurrence of dyed parts.

Conventionally, to attach a substance to the surface of a polymer chip, methods have been used, such as mixing the polymer chip with antibacterial powder or spraying, dipping, or coating with a solution or melt of the substance to be adhered. ing. This method has problems with uniformity, consistency, durability, adhesion density, etc. An even bigger problem is that the powder itself is too large to be melt-spun, and it tends to aggregate into giant particles during mixing, resulting in problem (2) above. As mentioned above, many proposals have been made regarding antibacterial fibers, but only one quality has been proposed for productivity.

A fiber that satisfies all antibacterial effects has not yet been obtained. In particular, the following points are important for antibacterial processing.

(1) Great effect.

(2) Good durability.

(3) It does not affect the physiological functions of the human body.

(4) It does not impair the physical properties and texture of the treated material.

(5) Easy workability.

(6) Easy to identify processing agents.

The present inventors investigated how to mix highly antibacterial metals, metal compounds, or antibacterial drugs with polymers to ensure stable operation and quality. How should polymers and antibacterial substances be mixed in order to maintain physical properties such as strength, elongation, and elastic modulus, as well as white discoloration and gloss, and to exhibit greater antibacterial properties?
Further, as a result of intensive studies on whether or not it should be placed in fibers, the present invention has been completed.

The purpose of the present invention is to provide a method for producing antibacterial composite fibers that have excellent effects such as antibacterial properties, durability, texture, yarn properties, and gloss, and productivity such as quality, spinnability, stretchability, and post-processability. There are suggestions.

(Means for solving problems) The method of the present invention involves vacuum deposition and thermal spraying of antibacterial substances.

An antibacterial composite fiber characterized in that a polymer attached to the surface by dry processing such as sputtering or ion blasting is formed as a component of the composite fiber, and the composite fiber is spun so that at least a part of the component is exposed. This is a manufacturing method.

Antibacterial properties can be evaluated, for example, by the AATCC method. The bacterial species is usually Staphylococcus aureus (Staphylococcus aureus).
us aureus), Bacillus subtilis (Bacillus 5
Durham-positive bacteria such as ubtills, Escherichia coli (Esch
Erichia coli) Pseudomonas aeruginosa
as aeruginosa), urea-degrading bacteria (Pro
teus vulgaris), Klebsiella pneumoniae (l(1e)
1) Durham-negative bacteria such as sellaoneumon 1ae) and Trichophyton
interdigita+), black mold fungus (Asper
Fungi such as Gillus niger) are used.

The antibacterial substance used in the present invention is a substance that has antibacterial properties, is solid at room temperature, gasifies under heating or vacuum heating, but does not decompose at the melting point of the polymer used. Examples include metals, metal compounds, organic compounds, and inorganic compounds that have antibacterial properties. Preferably, metals such as silver, copper, zinc, tin, and lead, and their sulfides, oxides, iodides, and bromides.

Metal compounds such as hydroxides. Among these, silver iodide and copper iodide, which have excellent antibacterial properties, are white or pale in color, and have stable physical properties, are particularly preferred for use in textiles and clothing.

As the polymer used in the present invention, those commonly used in the production of fibers by the melt spinning method can be used. Examples include polyester, polyamide, polyacrylonitrile, polyurethane, acrylic polymer polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polymethyl meccrylate, polycarbonate, polyoxymethylene, and the like. The shape of the polymer is the commonly used chip (Pereso 1).
f) 9 particles made by a normal manufacturing method may be used, but the most preferred form is a chip. For example, chips can be obtained by melting a polymer and extruding it through a die of several millimeters in diameter to form a strand, which is then cut into a predetermined length.

The size is usually at least 0.5 mm, preferably at least 1 mm. The smaller the polymer chip, the more uniformly the antibacterial substance will adhere to it, but the more problems occur during melt spinning. More preferably, it is 2 mm or more.

It is also possible to use commonly used additives such as titanium oxide, antimony oxide, and carbon blank in the polymer chip.

Attaching antibacterial substances to the surface of polymers is achieved using completely new methods such as vacuum evaporation, thermal spraying, and sputtering.

This is done by dry processing such as ion blating.

The ability to attach metals and metal compounds in the form of a thin film only to the surface of this polymer is the key to overcoming many previous difficulties.

One of the major features of the method of the present invention is that by vaporizing the antibacterial substance once in a vacuum, an extremely uniform and thin film (for example, possible from several people) can be formed on the polymer. Therefore, unlike when conventional fine particles are used, there are no problems such as the size of the particles being too large to make spinning impossible, yarn breakage occurring, or quality deterioration. The second feature is
By the time the metal and polymer are deposited in an extremely uniform film form on the polymer, mixing of the metal and polymer is complete, and there is no non-uniformity of mixing or formation of agglomerated particles unlike when blending fine particles. The third feature is metal.

Since the fine particles of the metal compound dispersed in the fibers are extremely small and uniform, the content of antibacterial substances can be reduced. The fourth characteristic is that it adheres to the melting polymer in the form of a close film, and for some metals and metal compounds, it adheres in an almost amorphous state, so it easily deforms as the polymer deforms. It has very good moldability and can be evenly dispersed in fibers, so good antibacterial properties can be obtained even with a small content.

Conventional methods such as vacuum evaporation, thermal spraying, sputtering, and ion blating can be used, but in order to treat polymer chips, for example, methods for evaporating antibacterial substances, stirring chips, and heat removal methods are described below. I'm going to try something like this. That is, as shown in attached figures 2 to 4, a polymer chip 2 is placed in a rotatable drum 1 placed in a vacuum container, and the drum is rotated to constantly agitate the chip and apply an antibacterial agent coating evenly over the entire surface of the chip. can be attached. It is also possible to remove the generated heat by cooling the drum with water.

In the vacuum evaporation method, for example, an apparatus as shown in attached Figure 2 is used. A polymer chip 2 is placed in a rotatable drum-shaped sample container 1 placed in a vacuum below l O't o r r, and while rotating the drum, electricity is applied to a resistance heating filament 4 containing an antibacterial substance 3. while evaporating the antibacterial substance and attaching it to the polymer chip. The adhesion rate can be determined from the change in chip weight before and after treatment. In order to minimize unnecessary decomposition and alteration of the polymer due to the heat of the heating source, it is better to keep the distance to the polymer at least 20 cm or more, and to cool the rotating drum in which the sample is placed by passing water through it. or,
A supply device is required so that the antibacterial substance for evaporation can be supplied each time.

Thermal spraying (most commonly plasma spraying) is shown for example in the attached figure -
This is possible using the device No. 3. A polymer chip 2 is placed in a rotatable drum-shaped sample container 1 installed in a vacuum space, and while the drum is rotated, fine particles of an antibacterial substance are injected into the plasma generation space 6 to partially melt the surface of the chip. attach it to. Plasma spraying has a considerably higher deposition rate than vacuum evaporation, ion blating, and sputtering, but generates more heat, which tends to cause polymer deterioration and chips to fuse together, and the process is somewhat less controllable.

0 Sputtering can be performed using, for example, the apparatus shown in attached Figure 4. The difference is that an antibacterial substance is used as the target 8 and low temperature plasma 9 is used as the evaporation energy of the target substance. Sputtering is carried out under the generation of low-temperature plasma, and although the rate of adhesion of antibacterial substances is slow, the degree of vacuum is 10-'torr, which is lower than other methods, and the evacuation system is simplified accordingly.

Ion blating is a method in which antibacterial substances vaporized by vacuum deposition are ionized in low-temperature plasma, accelerated, and adhered to a polymer chip, and has the highest adhesion strength.

The antibacterial substance is attached uniformly to at least one surface, preferably the entire surface, of the polymer.

As for the amount of adhesion, the film thickness is at most 10 μm, preferably 0.001 to 5 μm, and more preferably 0.01 to 1 μm.
It is m. For materials with high toughness such as metals, it is preferable that the film be thin, but for materials with relatively low toughness such as metal compounds, the film may be thick. If the film thickness of the antibacterial substance exceeds 10 μm, the deformation of the polymer will be poor during melt spinning, especially in the case of metal film forming chips, or the filter will become clogged, resulting in poor quality yarn or failure to spin. Even so, it may cause troubles such as yarn breakage and non-uniform stretching during drawing, or the quality of the obtained yarn may deteriorate, such as poor uniformity of fineness and a decrease in elongation. Also, 0. OO
When it is less than 1 μm, the content of antibacterial substances is low and antibacterial properties are not sufficiently expressed.

- When the size of the polymer chip attached to the fishing boat is small, it may be thin, but as the polymer chip becomes larger, it is necessary to attach it thicker. The state of adhesion of the antibacterial substance to the polymer can be determined by cutting one side of the polymer and observing the cross section using an optical microscope or an electron microscope.

The melting characteristics of the polymer chip of the present invention can be evaluated by the MI value (melt index value). M of untreated polymer
When the I value is 10, the MI value of the processing chip is at least 2 or more, preferably 5 or more. If the MI value is less than 2, melt moldability, spinnability and quality will deteriorate.

The adhesion of antibacterial substances to polymers depends on the type of antibacterial substance, the type of polymer, the size of chips, etc., and the method of use, such as whether or not the treated polymer is mixed with other polymers. Method.

Consider adhesion rate, etc.

The polymer obtained in this way can be produced using the usual melt composite spinning method.
For example, chips, etc. are pre-dried, then heated and stirred using an extruder to melt them, and if necessary, passed through a static mixer, etc., and then extruded from the nozzle through a filter, and subjected to a prescribed spinning and stretching process in an air bath. After cooling and solidifying, it is rolled up using a pick-up roller. Although it is possible to use only a single coating polymer during melt spinning, mixing with other coating polymers or mixing with untreated polymers is also necessary to control antibacterial properties and antibacterial agent content. During melt spinning, chips coated with antimicrobial substances can be used alone or in combination with other untreated polymer chips or chips coated with other substances.

3. As for the method of spinning the antibacterial composite fiber of the present invention, a normal composite spinning method can be adopted. By performing composite spinning so that at least a portion of the antibacterial polymer component is exposed on the fiber surface, it is possible to obtain fibers that have good antibacterial properties and are less likely to be colored by antibacterial substances. (1) to (9) of FIG. 1 show examples of cross sections perpendicular to the fiber axis direction of the composite fiber in the present invention. The polymeric component containing the antimicrobial substance is present at least in part on the surface of the fiber, and the surface layer of the fiber contains on average at least 50 ppm, preferably 10' Op p m, more preferably 150 ppm.
Contains antibacterial ingredients. For example, assuming that 50% of the antimicrobial polymer component is exposed on the entire fiber surface, the content of antimicrobial substances in the antimicrobial component is at least 1100 ppm, preferably 200 ppm, and more preferably 300 ppm.

The melt-spun undrawn yarn is then drawn near the glass transition point. After stretching, if necessary, it can be made into a product by twisting the yarn alone or in combination with other yarns.

The antibacterial substance is attached to the surface of the polymer, and exists either dispersed in the resulting fibers as fairly fine particles or stretched into long thin strips depending on the deformation of the polymer during melt spinning. Also, it is a substance attached to the polymer and exists uniformly regardless of whether it is inside or outside the fiber. For metals, the existence form of antibacterial substances can be observed using an optical microscope or an electron microscope.

Evaluation of the content of antibacterial substances in fibers can be determined by the adhesion rate of antibacterial substances on the polyester and the usage rate of the polymer, and chemical analysis methods and atomic absorption spectroscopy methods can be used.

This can also be done by fluorescent X-ray analysis, X-ray microanalyzer method, etc. Usually, the content of antibacterial substances is at most 10% by weight, preferably from 5x10-4 to 5% by weight, and more preferably from 1x10-3 to 1.0% by weight. The obtained fibers have dyeability, processability, texture, etc. similar to ordinary fibers, and can be handled without any problems in weaving, knitting, nonwoven fabrics, dyeing, resin processing, etc. In particular, conventional yarns obtained by mixing and spinning antibacterial metal particles, ceramics (antibacterial zeolite), etc., may suffer from a decrease in fiber strength, elongation, abrasion resistance, and durability, or the fibers may become dull. Nor.

(Examples) Hereinafter, the present invention will be explained in more detail by way of Examples, but the present invention is not limited thereto. In addition, evaluation of each item in the example was performed as follows.

1. Adhesion rate of antibacterial substance Adhesion rate (wt%) Weight of chip after treatment - Weight of untreated chip Weight of untreated chip 2. Evaluation of antibacterial properties was carried out according to the shake flask method of the AATCC method.

The bacteria used was Escherichia coli. First, a certain amount of refrigerated Escherichia coli is taken with a platinum spoon, transferred to 20 ml of bouillon aqueous solution, and cultured and grown at room temperature for about one day to prepare a stock solution.

A bacterial solution obtained by diluting this original bacterial solution 100 times with physiological saline was used for testing. This bacterial liquid is 50mj! Place in a sealed Erlenmeyer flask, and cut 1 g of the fabric to be evaluated into approximately 1 cm square pieces and soak well.

Next, it is shaken for 1 hour using a shaker that shakes in two directions, horizontal and vertical. After shaking, 1 ml of this solution is diluted 100 times with physiological saline, and 0.1 ml of the diluted solution is inoculated onto an agar medium containing 15 mβ broth. This was cultured in Franchi at 37° C. for 18 hours, the number of E. coli colonies on the agar was counted, and the antibacterial property was evaluated by the bacterial killing rate (%) using the following formula. In addition, CO represents the number of colonies in the product without sample cloth, and C represents the number of colonies in the product with sample cloth.

Bacterial killing rate (%) = (Co-C)/Cox100Co side 1 200 g of polyethylene terephthalate chips with major axis 3 mm, minor axis 2 mm, and length 3 mm were placed in a vacuum evaporation device shown in attached Figure 2 without rotating the chip. m(Ag) was coated. The coating amount was determined from the change in chip weight and was 1.0%. The surface of the chip was colored silver, indicating that a good coating layer was formed.

A sheath/core type conjugate yarn as shown in FIG. 1 (1) was spun using the silver-coated chip and the untreated chip. The ratio of sheath to core was 1:4. The yarn was spun using a 20 mm Ex7 Klugoo, extruded through a 0.25 mm 24-hole nozzle, and wound up. The spun yarn was then drawn at a magnification of 4 times, and then a circular knitted fabric was made using a 20 gauge. still,
As a comparative example (No. 6), an example of a circular knitted fabric obtained by independently spinning and drawing a polymer mixture of silver coated chips/untreated chips at 1/1 so as to obtain yarns with the same fineness as the above fibers is shown. Ta.

As a comparative example (No. 7), a fiber in which 1.5% of antibacterial zeolite (Sinane Zeo-Ag, Cu) was kneaded into the fiber was shown.

Table 1 shows the results. In the product of the present invention, it was observed that extremely fine silver particles were dispersed in the sheath portion of the composite fiber in an extremely well dispersed state. Furthermore, although the color of the cloth before dyeing increased in yellow with the silver content in the fibers, the antibacterial properties were good even with a small amount of silver content.

The antibacterial properties of the tubular knitted fabric were evaluated using the method described above.

The color tone of the product of the present invention is bright and has excellent color development, whereas the comparative example (No. 7) is 8 times more yellow than the product of the present invention at the same addition rate of silver having antibacterial properties. The coloring was large, and the comparative example (No. 8) had a dull tone and poor color development.

The fibers of the present invention were compared in terms of yarn quality, gloss, color, etc.Example 2 Composite spinning using the N003 chips of Example 1 and untreated chips in the cross-sectional shape shown in attached Figure 1 (5) I did it. The spinning conditions were the same as in Example 1. 3 with extension up
．． A yarn of 1d/24f was obtained.

The gloss was good, and the antibacterial properties showed a 40% bacterial killing rate.

(Effects of the Invention) One of the major features of the present invention is that by once vaporizing the antibacterial substance in a vacuum, a thin film having an extremely small size or a size on the order of molecules or atoms is formed on the polymer. It is something that can be done. Therefore, unlike conventional fine particles, which are large in size, and even if they are small, there is no deterioration in operability or quality such as poor spinnability or yarn breakage due to a large number of agglomerated particles.

The second feature is that since it is attached to the polymer in an extremely uniform film, there is no uneven mixing or formation of agglomerated particles that occurs when blending fine particles. The third feature is that because it adheres to the melting polymer in the form of a tight film, it deforms as the polymer deforms and has very good moldability.
It can be uniformly dispersed in the fiber.

Furthermore, since the antibacterial polymer component does not enter the entire cross-section of the fibers, but only a part of the fiber cross section, color changes caused by antibacterial substances and changes in color due to decreases in light resistance are considerably alleviated.

According to the present invention, it has become possible to produce antibacterial fibers containing any antibacterial substance in any polymer in any ratio extremely uniformly without any trouble.

Furthermore, the fibers of the present invention have physical properties that are no different from ordinary fibers.
It has processability and can be subjected to blending, interweaving, interweaving, dyeing, resin processing, etc., and has the same feel and physical properties as ordinary fibers.

[Brief explanation of drawings]

Attached Figures 1 (1) to (9) show examples of cross sections perpendicular to the fiber axis direction of composite fibers in the present invention. a indicates a polymer component containing an antibacterial substance. b indicates a polymer component without antibacterial substances. Attached Figures 2 to 4 show the main parts of the device for processing chips of the present invention. Attached Figure 2 shows a vacuum evaporation apparatus, in which 1 shows a rotatable sample container, 2 shows a sample, 3 shows an antibacterial substance, and 4 shows a filament for resistance heating. Attached Figure 3 shows a plasma spraying device, where ■ is a rotatable sample container, 2 is a sample, 5 is a supply port for antibacterial substance powder or fine particles, 6 is a cathode electrode, and 7 is a supply port for plasma gas. . Attached Figure 4 shows a sputtering apparatus, in which ``■'' is a rotatable sample container, 2 is a sample, 8 is a target containing an antibacterial substance, 9 is an anode electrode, and 10 is a high frequency power source. Figure-1 (1) (2) (7) b (8) (9)

Claims (1)

[Claims] A polymer with an antibacterial substance attached to the surface by dry processing such as vacuum evaporation, thermal spraying, sputtering, and ion plating is melt-spun and used as a component of composite fiber.
A method for producing an antibacterial composite fiber, which comprises performing composite spinning so that at least a portion of the component is exposed.