JP2009228200A - Functional fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive functional fiber which is good in appearance, is excellent in formability, and has sufficient adsorbability and microprotein-inactivating property, and to provide a nonwoven fabric using the fiber. <P>SOLUTION: Provided is the functional fiber in which a core layer 2 comprises a thermoplastic resin, and a sheath layer 3 comprises a thermoplastic resin containing fine metal particles having a bond between an organic acid component and the metal. The metal is selected from specific metals such as Cu, Ag, Au, In, and Pd. The organic acid component is preferably a 3-30C fatty acid. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a functional fiber having effects such as adsorptivity and microprotein inactivation, and relates to a fiber used for, for example, a nonwoven fabric, a filter, clothing, and the like.

In recent years, there are various bacteria and molds in the living space of society due to changes in lifestyles, and an increasing number of people have lifestyle-related diseases caused by allergies such as spoiled odors such as microorganisms and garbage and pollinosis.
On the other hand, products made of fibers are attracting attention as a versatile material with a large degree of development, covering a considerable part of the use of cloth, paper and film and providing various functions. For example, it is widely used in textile products such as clothing, protective and protective clothing, construction, vehicles and automobile interiors, sanitary products, and functional materials such as antibacterial agents or deodorants are mixed or contained in these textiles. It is proposed below to give these functions. An antibacterial fiber containing colloidal particles mixed with a resin raw material at a temperature lower than the thermal decomposition temperature of silver stearate has been proposed (Patent Document 1). Further, from the viewpoint of durability of the fiber and restriction of the amount of antibacterial agent used, a core-sheath fiber in which a functional material such as silver ion, zeolite, zirconium phosphate or the like is contained in the sheath layer has been proposed (Patent Document 2). ~ 5).

Even if the deodorant and antibacterial substances described in the above patent documents are contained in the fiber, the conventional excellent effects of the deodorant or antibacterial substances are hardly expressed in the resin, or the deodorant Or there exists a problem that a deodorizing effect etc. fall or it is inadequate because an antimicrobial site will be saturated.
From such a point of view, the present inventors have proposed a molded body in which ultrafine metal particles capable of desorbing adsorptive and microproteins are dispersed in a resin (WO 2008/29932, WO 2008/69034).

JP 2005-48031 A Japanese Patent No. 3071594 Japanese Patent Laid-Open No. 09-87928 JP-A-11-61569 Japanese Patent Laid-Open No. 11-189919

Since the deodorant and antibacterial agent of the above-mentioned patent document are colloidal, the single yarn strength is extremely small particularly in the case of ultrafine fibers, so that yarn breakage occurs and the fiber diameter is not stable. Furthermore, the particle diameter is limited by the fiber diameter. If the particle diameter is large, the ultrafine fiber moldability is inferior, and in order to obtain a sufficient effect, it is necessary to increase the content, resulting in a high cost.
In addition, those using porous materials adsorb odorous components or volatile organic compounds (hereinafter referred to as “VOC”) to develop an adsorption effect (deodorization effect), etc., so the adsorption site is saturated. There is a problem that the effect disappears when the state is reached.

  Further, when using the ultrafine metal particles mixed with the resin, the surface of the ultrafine metal particles is in direct contact with the resin, so that the resin is decomposed and the moldability is remarkably hindered. In order to form ultrafine metal particles from the viewpoint of handling properties, a dispersion liquid of alcohol or the like is necessary, and it was not fully satisfactory for blending and molding into fibers, particularly ultrafine fibers.

In order to solve the above problem, in the present invention, the core layer is made of a thermoplastic resin, the sheath layer is made of a thermoplastic resin containing ultrafine particles having a bond between an organic acid component and a metal,
1. 1. The metal is made of at least one selected from the group consisting of Cu, Ag, Au, In, Pd, Pt, Fe, Ni, Co, Zn, Nb, Sn, Ru, and Rh. The organic acid component is a fatty acid having 3 to 30 carbon atoms;
3. The sheath layer has a plasmon absorption of 300 to 700 nm,
4). The functional fiber has adsorptive and microprotein inactivation;
5. A nonwoven fabric composed of functional fibers is preferred.

According to the present invention, there is provided an inexpensive functional fiber in which ultrafine metal particles are uniformly dispersed in the sheath layer of the fiber, the appearance is excellent, the moldability is excellent, the adsorptivity and the microprotein inactivation are provided. . Furthermore, it is excellent in detachment resistance and washing resistance.
Especially the fiber of this invention is utilized suitably for a nonwoven fabric.

  As described above, according to the present invention, the functional fiber composed of the thermoplastic resin including the core layer of the thermoplastic resin and the sheath layer including the ultrafine metal particles having a bond between the organic acid component and the metal is adsorbed. Since the surface area in contact with the substance, allergic substance, etc. can be increased, the reaction with the adsorbing substance is excellent, the adsorbability is greater than that of normal particles, and the inactivation of microproteins such as allergic substances is excellent. In addition, metallic ultrafine particles having a bond between the organic acid component and the metal may be contained in the core-sheath layer, but the microprotein inactivation is particularly concerned because the metallic ultrafine particles present in the vicinity of the fiber surface are greatly involved. It is important to be dispersed in the sheath layer, and in combination with the configuration in which the core layer is made of a thermoplastic resin, there is an effect that thread breakage hardly occurs and stable molding can be performed.

  In addition, the present invention has an important feature that the ultrafine metal particles are a combination of an organic acid and a metal, and the average particle size of the ultrafine metal particles is preferably 1 to 100 nm, and more preferably 1 to 20 nm. It is preferable that In addition, the average particle diameter referred to in the present specification refers to an average value of particles having no gap between metals as one particle.

  The sheath layer of the fiber of the present invention preferably exhibits a plasmon absorption phenomenon at 300 to 700 nm in that it has adsorptivity and microprotein inactivation. The plasmon absorption indicates that the metal ultrafine particles are dispersed in the thermoplastic resin. On the other hand, when the plasmon absorption phenomenon is not exhibited, the metal ultrafine particles are not dispersed, or the metal ultrafine particles are not dispersed. It can be confirmed that it is not formed. The plasmon absorption wavelength is specific to the type of metal. In the case of silver ultrafine particles, an absorption phenomenon is observed near the wavelength of 420 nm.

  The molding temperature of the fiber of the present invention is preferably a temperature at which the organic acid metal salt is thermally decomposed in the resin used as the raw material of the fiber. Ultra fine particles are formed and uniformly dispersed. On the other hand, when the molding temperature is such that the organic acid metal salt is not thermally decomposed in the resin, ultrafine metal particles are not formed in the resin.

  Although it does not restrict | limit especially as a metal component couple | bonded between the organic acid component and metal of this invention, Cu, Ag, Au, In, Pd, Pt, Fe, Ni, Co, Nb, Sn, Ru, Rh etc. are mentioned. be able to. In particular, Ag, Au, Pt, Sn and the like are preferable. These simple substance, a mixture, an alloy, etc. may be sufficient.

The organic acid component of the present invention is bonded to a metal, and the organic acid component is preferably a fatty acid having 3 to 30 carbon atoms. Myristic acid, stearic acid, oleic acid, palmitic acid, n-decanoic acid, paratoyl Acid, succinic acid, malonic acid, tartaric acid, malic acid, glutamic acid, adipic acid, acetic acid and other aliphatic carboxylic acids, phthalic acid, maleic acid, isophthalic acid, terephthalic acid, benzoic acid, naphthalenic acid and other carboxylic acids, cyclohexanedicarboxylic acid Examples thereof include alicyclic carboxylic acids such as acids.
In the present invention, myristic acid, stearic acid, oleic acid, and palmitic acid are particularly preferable.

  Substances adsorbed on the fibers of the present invention include ammonia, trimethylamine, hydrogen sulfide, methyl mercaptan, methyl sulfide, methyl disulfide, acetaldehyde, styrene, propionic acid, norman butyric acid, norman valeric acid, isovaleric acid, toluene, xylene, Examples include ethyl acetate, methyl isobutyl ketone, isobutanol, propionaldehyde, normal butyraldehyde, isobutyraldehyde, normal valeraldehyde, and isovaleraldehyde. Among these, it acts effectively on odors containing sulfur components.

  The fiber of the present invention inactivates microproteins such as pollen, mold, virus, fungus, fungus, etc., and effectively decomposes the disulfide bond contained in the protein, resulting in an excessive immune reaction by the antibody. Suppress working.

  The fiber diameter of the present invention is preferably 1 to 100 μm, and the diameter of the cross section of the core layer is preferably 5 to 99 μm. If the fiber diameter is larger than 100 μm, the surface area is small, so that the adsorptivity and microprotein inactivation are not excellent. If the fiber diameter is smaller than 1 μm, yarn breakage occurs and stable molding cannot be performed.

As the thermoplastic resin of the sheath layer and the core layer containing the ultrafine metal particles of the present invention, any conventionally known one can be used as long as it is a thermoplastic resin that can be melt-molded. For example, low-, medium-, high -Density polyethylene, linear low density polyethylene, linear ultra-low density polyethylene, isotactic polypropylene, syndiotactic polypropylene, propylene-ethylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene -1 copolymer, ethylene-propylene-butene-1 copolymer and other olefin resins, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and other polyester resins, nylon 6, nylon 6,6, nylon 6,10 and the like Polyamide resin, polycarbonate resin, polyvinyl alcohol Lumpur resins, methacrylic resins.
The thermoplastic resin of the core layer is preferably a resin having a melting point higher than that of the thermoplastic resin of the sheath layer, and a polypropylene resin and a polyester resin are preferably used from the viewpoint of durability.

  Products made of the fibers of the present invention are nonwoven fabrics, clothing, protective and protective clothing, architecture, vehicles and automobile interiors, diapers, wipers for cleaning, toothbrushes, pet toilets, pet care products, pack sheets, soft incontinence products, curtains Chair upholstery, bedding, wet tissue, ventilation fan filter, sulfide filter, water treatment filter bed mattress, seat belt, mat, cushion, hose, wiping cloth, fabric product, cosmetic puff, mask, sanitary product, first aid, For furniture, filters / air-conditioning filters, agriculture / horticulture, greenhouse sheets, artificial leather fabrics, living materials, industrial materials, packaging materials, electronic materials, medical treatment, aramid fibers, carbon fibers, active short fibers, hollow fiber membranes, etc. Can be used. In particular, as a nonwoven fabric product made of the fiber of the present invention, it is preferable to use it as an air filter or a mask. In addition, the nonwoven fabric product can constitute a nonwoven fabric having a single layer structure, but can also have a multilayer construction with a plurality of sheets.

(Fatty acid metal salt)
The metal component of the organic acid metal salt used for forming the ultrafine metal particles in the fiber of the present invention is not particularly limited, but Cu, Ag, Au, In, Pd, Pt, Fe, Ni, Co, Nb, Sn, Ru, Rh, etc. can be mentioned, among which Au, Ag, Cu, Pt, Sn, and particularly Ag is preferred.
In addition, as fatty acids, aliphatic carboxylic acids such as myristic acid, stearic acid, oleic acid, palmitic acid, n-decanoic acid, paratoylic acid, succinic acid, malonic acid, tartaric acid, malic acid, glutaric acid, adipic acid, acetic acid, Examples include alicyclic carboxylic acids such as cyclohexanedicarboxylic acid.
In the present invention, the fatty acid to be used is particularly preferably a higher fatty acid having 3 to 30 carbon atoms such as myristic acid, stearic acid, palmitic acid and the like. A component or VOC can be adsorbed, and the adsorptivity, (deodorizing effect), and microprotein inactivation can be further improved.
Examples of the most suitable organic acid metal salt include silver myristate, silver stearate and the like, and an average particle diameter of 1 to 100 μm, particularly 20 to 80 μm is uniformly dispersed in the resin. Is preferable.

(Nonwoven fabric manufacturing method)
The core-sheath fiber made of the fiber of the present invention can be produced by a known method, and examples thereof include a melt spinning method, a wet spinning method, and a dry spinning method. In general, the polymer can be produced by a melt spinning method in which a polymer is heated and pressure is applied to remove the noise while cooling to produce a fiber.
Moreover, the nonwoven fabric which consists of the said core-sheath fiber of this invention can be produced by a well-known method, A chemical bond, a needle punch, and a wet nonwoven fabric method are mentioned as a spun bond method, a melt blow method, and a dry nonwoven fabric method. In the spunbond method, each core-sheath resin is fed into a feeder and heated and kneaded by a twin-screw extruder, and the core-sheath type thread-like resin discharged from the nozzle via a gear pump and a spin head is cooled by cooling air. After that, it passes through the air ejector and is drawn. The stretched filamentous resin forms a web on a conveyor and is heat-compressed with a compaction roll or embossing roll to obtain a nonwoven fabric. In addition, the melt blow method can effectively obtain a non-woven fabric made of ultrafine fibers of 10 μm or less by ejecting a resin from a nozzle, and therefore effectively acts on the adsorptivity and inactivation of minute proteins.

  In the method for producing a functional fiber of the present invention, it is generally carried out by mixing and heating a fatty acid metal salt and a thermoplastic resin as raw materials in a twin-screw extruder, and the fatty acid metal salt is generally decomposed to produce ultrafine metal particles. It is necessary to heat at a temperature equal to or higher than the decomposition start temperature of the fatty acid metal salt. The decomposition start temperature of the fatty acid metal salt is a temperature at which the fatty acid portion begins to desorb or decompose from the metal portion, and the start temperature is generally defined by JIS K 7120. According to this, the mass of the organic compound (fatty acid metal salt) is measured, and thermogravimetry (TG) is performed to measure the change in weight when the temperature is raised in an inert atmosphere using a thermogravimetry apparatus. The decomposition start temperature is calculated from the thermogravimetric curve (TG curve) obtained by the measurement. It is defined that the temperature at the point where the line parallel to the horizontal axis passing through the mass before the start of test heating and the tangent line at which the gradient between the bending points in the TG curve becomes maximum is the starting temperature. However, the present invention does not require heating at a temperature higher than the decomposition start temperature of the fatty acid metal salt defined above. This is because, in practice, in the present invention, while being heated at a temperature lower than the decomposition start temperature of the fatty acid metal salt, it is affected by the shear heat generation by the screw or the residence time in addition to the set temperature of the twin screw extruder. The fatty acid metal salt is decomposed to form ultrafine metal particles by adjusting processing conditions such as residence time, heating time, and screw rotation speed.

  Although the processing conditions of the fatty acid metal salt cannot be generally limited, for example, when silver stearate having a decomposition start temperature of 220 ° C. as a fatty acid is used as the fatty acid according to the above JIS definition, It is preferable to perform heating and mixing at a temperature of less than 220 ° C. and a heating time of 5 to 1800 seconds, particularly 10 to 300 seconds, depending on the set temperature of the twin screw extruder at a temperature within this range.

1. Spectral transmittance measurement The nonwoven fabric obtained in the example was hot-pressed at a temperature of 150 ° C. to form a sheet having a thickness of 50 μm, and the spectral transmittance of the sheet was measured to confirm the presence or absence of plasmon absorption at 300 to 700 nm. .

2. Measurement of undeodorized methyl mercaptan concentration 5 μl of malodorous methyl mercaptan was injected with a microsyringe into a 500 ml glass bottle filled with nitrogen gas with the mouth sealed with a rubber stopper, and the concentration was adjusted to 10 ppm. And left at room temperature (25 ° C.) for 1 day. After leaving for 1 day, a detector tube manufactured by Gastec Co., Ltd. was inserted into the bottle, and the residual methyl mercaptan concentration was measured to obtain the methyl mercaptan concentration (A) when not deodorized.

3. Measurement of the amount of methyl mercaptan after deodorization A 500 ml glass in which a nonwoven fabric (fiber diameter 16 μm, basis weight 50 g / m) made of a thermoplastic resin containing ultrafine metal particles in a thermoplastic resin was cut into a 50 mm square and replaced with nitrogen gas After putting in a bottle and sealing with a rubber stopper, 5 μl of malodorous methyl mercaptan is injected into the bottle with a microsyringe, adjusted to a concentration of 10 ppm, and left at room temperature (25 ° C.) for 1 day. did. After leaving for 1 day, a detector tube manufactured by Gastec Co., Ltd. was inserted into the bottle, the residual methyl mercaptan concentration was measured, and the methyl mercaptan concentration (B) was obtained after deodorization.

4). Calculation of deodorization rate of methyl mercaptan Value obtained by subtracting the deodorized methyl mercaptan concentration (B) from the undeodorized methyl mercaptan concentration (A) and dividing it by the undeodorized methyl mercaptan concentration (A) as a percentage Was defined as a deodorization rate.

Example 1
A low-density polyethylene resin blended with a silver stearate content of 5 wt% was introduced from a resin inlet, and an extrusion master batch was produced by a twin-screw extruder at a primary molding temperature of 180 ° C. Next, the master batch was blended so that the core layer had a polypropylene resin, the sheath layer had a low density polyethylene resin and the silver stearate content was 1% by weight, and the secondary molding temperature was 200 ° C. Kneaded, extruded from a nozzle diameter of 600 μm, stretched with an air ejector, and heat-pressed with an embossing roll to prepare a nonwoven fabric having a fiber diameter of 16 μm with a core layer / sheath layer ratio of 3: 7. Calculation of the deodorization rate of the obtained nonwoven fabric and measurement of spectral transmittance were performed.

(Example 2)
A nonwoven fabric was prepared in the same manner as in Example 1 except that the secondary molding temperature was 180 ° C., and the deodorization rate was calculated and measured.

(Example 3)
A nonwoven fabric was prepared in the same manner as in Example 1 except that the content of silver stearate in the sheath layer was 0.5% by weight, and the deodorization rate was calculated and measured.

Example 4
A nonwoven fabric was prepared in the same manner as in Example 1 except that the secondary molding temperature was 220 ° C., and the deodorization rate was calculated and measured.

(Example 5)
A nonwoven fabric was prepared in the same manner as in Example 1 except that the content of silver stearate in the sheath layer was 1.5% by weight, and the deodorization rate was calculated and measured.

(Example 6)
A nonwoven fabric was prepared in the same manner as in Example 1 except that silver myristate was used, and the deodorization rate was calculated and measured.

(Comparative Example 1)
Nonwoven fabric as in Example 1 except that a master batch was prepared so that silver stearate having a particle size of 100 nm obtained by heating silver stearate at a temperature of 250 ° C. in an inert gas atmosphere was 5% by weight. The deodorization rate was calculated and measured.

(Comparative Example 2)
A master batch was prepared by blending so that the zeolite content was 5% by weight, and a nonwoven fabric was prepared in the same manner as in Example 1 except that the sheath layer was made of zeolite, and the deodorization rate was calculated and measured. .

(Comparative Example 3)
A master batch was prepared by blending so that the content of the inorganic deodorant (Toa Gosei Co., Ltd .: registered trademark “Kesmon”) was 5% by weight, and an inorganic deodorant was blended in the sheath layer. A nonwoven fabric was produced in the same manner as in Example 1, and the deodorization rate was calculated and measured.

(Comparative Example 4)
A non-woven fabric was prepared in the same manner as in Example 1 except that a master batch was prepared by blending so that the content of silver (particle size: 4.5 μm) was 5% by weight, and silver was blended in the sheath layer, and the deodorization rate Was calculated and measured.

The results are shown in Table 1. From the above results, it can be seen that Examples 1 to 6 have an excellent deodorizing effect. Moreover, although evaluation of microprotein inactivation was not performed, it is thought that it has microprotein inactivation like a deodorizing effect.

Sectional drawing of a core sheath type fiber is shown.

1 Fiber 2 Core layer 3 Sheath layer

  The functional fiber of the present invention can provide a functional fiber in which ultrafine metal particles are uniformly dispersed in the sheath layer of the fiber, the appearance is excellent, the moldability is excellent, the adsorptivity and the microprotein inactivation are excellent. In addition, because it can be easily molded, non-woven fabrics, clothing, protective and protective clothing, architecture, vehicles and automobile interiors, diapers, wipers for cleaning, toothbrushes, pet toilets, pet care products, pack sheets, soft incontinence products, curtains Chair upholstery, bedding, wet tissue, ventilation fan filter, sulfide filter, water treatment filter bed mattress, seat belt, mat, cushion, hose, wiping cloth, fabric product, cosmetic puff, mask, sanitary product, first aid, Furniture, filters / air conditioning filters, agriculture / horticulture, plastic house sheets, artificial leather base fabrics, living materials, industrial materials, packaging materials, electronic materials, medical treatment, aramid fibers, carbon fibers, active short fibers, hollow fiber membranes, etc. Available for products.

Claims (6)

A functional fiber, wherein the core layer is composed of a thermoplastic resin, and the sheath layer is composed of a thermoplastic resin containing ultrafine metal particles having a bond between the organic acid component and the metal. The function according to claim 1, wherein the metal is made of at least one selected from the group consisting of Cu, Ag, Au, In, Pd, Pt, Fe, Ni, Co, Zn, Nb, Sn, Ru, and Rh. Sex fibers. The functional fiber according to claim 1 or 2, wherein the organic acid component is a fatty acid having 3 to 30 carbon atoms. The functional fiber according to claim 1, wherein the sheath layer has plasmon absorption at 300 to 700 nm. The functional fiber according to claim 1, wherein the functional fiber has adsorptivity and microprotein inactivation. A non-woven fabric comprising the functional fiber according to claim 1.