Polyurethane elastic yarn and its manufacturing method

Abstract

To provide a polyurethane elastic yarn excellent in antibacterial properties and a method for producing the same.SOLUTION: A polyurethane elastic yarn comprises a polyurethane whose main components are a polymer diol and a diisocyanate, and contains a gently water-soluble glass containing a group 1B element and / or a group 2B element and a nonionic surfactant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyurethane elastic yarn having excellent antibacterial properties and excellent resistance to discoloration, and more particularly to a polyurethane elastic yarn suitable for producing antibacterial fabrics and a method for producing the same. [Background technology]

[0002] Due to their excellent elasticity, elastic fibers are widely used in stretchable clothing such as legwear, innerwear and sportswear, sanitary products such as disposable diapers and sanitary napkins, and industrial materials.

[0003] In recent years, with the demand for more comfortable living environments, so-called "antibacterial products" such as antibacterial paints, antibacterial films and sheets, antibacterial filaments, antibacterial toiletries, antibacterial kitchen utensils, antibacterial stationery, antibacterial sand, antibacterial tissues, antibacterial fibers, and antibacterial cosmetics have become widely available.

[0004] The antibacterial agents used in these products are often inorganic antibacterial agents, particularly silver-based antibacterial agents.

[0005] The inorganic antibacterial agents mentioned above have superior properties compared to organic antibacterial agents, such as superior weather resistance and chemical resistance, and low acute oral toxicity. In addition, their heat resistance is significantly higher than that of organic antibacterial agents, so they have come to be used in a wide range of fields by being added to synthetic resins.

[0006] Metal ions constituting the inorganic antibacterial agents include silver, mercury, copper, zinc, and tin, with silver ions and copper ions being particularly prominent. Supporting these ions on porous materials such as glass, zeolite, silica gel, silicates, whiskers, alumina, and ceramics can provide excellent antibacterial effects. Many techniques for applying these ions to fibers have been proposed (Patent Documents 1 to 3).

[0007] However, when inorganic antibacterial agents are added to synthetic resins and then molded, problems tend to arise in which the value of the product is significantly reduced due to defects caused by gelation of the synthetic resin or changes in molecular weight due to the crosslinking or catalytic action of the metals contained in the inorganic antibacterial agent, thermal discoloration during molding, discoloration due to NOx gas to which the molded product is exposed, and discoloration due to light irradiated onto the molded product.

[0008] Therefore, a technology has been proposed to suppress discoloration of antibacterial resins to which inorganic antibacterial agents have been added (Patent Document 4). However, although these technologies provide a certain level of antibacterial performance, they are prone to significant discoloration due to the environment and the passage of time, and it is difficult to say that they have adequately solved the problem of yellowing resistance. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 5-339810 [Patent Document 2] Japanese Patent Application Publication No. 6-93565 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-40007 [Patent Document 4] Patent No. 4485871 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a polyurethane elastic yarn having excellent antibacterial properties and excellent colorfastness, and a method for producing the same. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention employs any of the following means. (1) A polyurethane elastic yarn whose main constituent is a polyurethane whose main starting materials are a polymer diol and a diisocyanate, and which contains (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and (b) a nonionic surfactant. (2) The polyurethane elastic yarn according to (1) above, in which the content of (a) is 0.1% by mass or more and 30% by mass or less. (3) The polyurethane elastic yarn according to (1) or (2) above, wherein the average primary particle size of (a) is 3.0 μm or less. (4) The polyurethane elastic yarn according to any one of (1) to (3) above, wherein (a) is a slightly water-soluble glass containing silver and / or a slightly water-soluble glass containing copper. (5) The polyurethane elastic yarn according to any one of (1) to (4) above, wherein (b) is polyoxyethylene alkyl ether. (6) The polyurethane elastic yarn according to any one of (1) to (5) above, which contains a quaternary ammonium salt-based antibacterial agent. (7) A method for producing an elastic polyurethane yarn, comprising: mixing a spinning dope containing polyurethane, the starting materials of which are a polymer diol and a diisocyanate, with (a) a slightly water-soluble glass containing a 1B group element and / or a 2B group element; mixing a nonionic surfactant in an amount of 0.01% by mass or more and 20% by mass or less of the (a) slightly water-soluble glass containing a 1B group element and / or a 2B group element; and dry-spinning the spinning dope. (8) A method for producing a polyurethane elastic yarn according to (7) above, in which (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element is mixed as a dispersion into a spinning dope containing polyurethane whose main starting materials are a polymer diol and a diisocyanate. (9) (a) The method for producing polyurethane elastic yarn according to (7) or (8) above, wherein the Group 1B element and / or Group 2B element is silver and / or copper. (10) The method for producing polyurethane elastic yarn according to any one of (7) to (9) above, wherein (b) is polyoxyethylene alkyl ether. [Effects of the Invention]

[0012] According to the present invention, it is possible to obtain an elastic polyurethane yarn made of polyurethane whose main components are polymer diol and diisocyanate, which contains (a) a slightly water-soluble glass containing a 1B group element and / or a 2B group element and a nonionic surfactant, and which has excellent antibacterial properties, discoloration resistance, and stretchability.As a result, a fabric using such polyurethane elastic yarn has excellent antibacterial properties, discoloration resistance, and stretchability. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in further detail below.

[0014] First, we will discuss the polyurethane used as the main component in the polyurethane elastic yarn of the present invention. Here, the main component is a component contained in the polyurethane elastic yarn in an amount of more than 50% by mass.

[0015] The polyurethane used in the present invention may be any polyurethane having a structure derived from polymer diol and diisocyanate as the main starting materials, and is not particularly limited. Here, using polymer diol and diisocyanate as starting materials means that the resulting polyurethane polymer has a structure derived from each of these components. In other words, the term "using polymer diol and diisocyanate as starting materials" as used herein refers to the structure of a polyurethane polymer obtained from polymer diol and diisocyanate as starting materials; it does not specify the raw materials themselves, as the same structure may be formed from different raw materials. Furthermore, the synthesis method is not particularly limited. For example, the polyurethane may be a polyurethane urea consisting of a polymer diol, a diisocyanate, and a low-molecular-weight diamine as a chain extender, or a polyurethane urethane consisting of a polymer diol, a diisocyanate, and a low-molecular-weight diol as a chain extender. Furthermore, the polyurethane may be a polyurethane urea using a compound having a hydroxyl group and an amino group in the molecule as a chain extender. It is also preferable to use trifunctional or higher polyfunctional glycols, isocyanates, etc., as long as they do not interfere with the effects of the present invention. Here, a polyurethane having a structure in which polymer diol and diisocyanate are the primary starting materials refers to a starting material in which the isocyanate compounds in the starting material contain more than 50% by weight of diisocyanate, and the starting material contains more than 50% by weight of polymer diol among the components that react with the isocyanate compounds (polymer diol, low molecular weight diamine, low molecular weight diol, compound having hydroxyl group and amino group in the molecule, polyfunctional glycol, etc.). Note that when calculating the mass ratio, the calculation is performed assuming that the above components are used as starting materials, regardless of the actual raw materials used. Furthermore, among diol compounds, low molecular weight diol refers to one with a molecular weight of less than 500, and one with a molecular weight of 500 or more is called a polymer diol (the same applies to diamine compounds).

[0016] The polymer diol is preferably a polyether-based diol, a polyester-based diol, a polycarbonate diol, etc. In particular, from the viewpoint of imparting flexibility and elongation to the yarn, it is preferable to use a polyether-based diol.

[0017] Preferred examples of polyether diols include polyethylene oxide, polyethylene glycol, polyethylene glycol derivatives, polypropylene glycol, polytetramethylene ether glycol (hereinafter abbreviated as PTMG), modified PTMG which is a copolymer of tetrahydrofuran (THF) and 3-methyltetrahydrofuran, modified PTMG which is a copolymer of tetrahydrofuran (THF) and 2-methyltetrahydrofuran, modified PTMG which is a copolymer of THF and 2,3-dimethylTHF, polyols having side chains on both sides as disclosed in Japanese Patent No. 2615131, and random copolymers in which THF and ethylene oxide and / or propylene oxide are irregularly arranged. These polyether diols may be used alone or in combination or copolymerized with two or more.

[0018] Furthermore, from the viewpoint of obtaining abrasion resistance and light resistance as polyurethane elastic yarn, polyester-based diols such as butylene adipate, polycaprolactone diol, and polyester polyols having side chains as disclosed in JP-A-61-26612, and polycarbonate diols as disclosed in JP-B-2-289516 are preferably used.

[0019] These polymer diols may be used alone or in combination or copolymerized form.

[0020] From the viewpoint of obtaining elongation, strength, heat resistance, etc. when made into a thread, the molecular weight of the polymer diol is preferably a number average molecular weight of from 1000 to 8000, more preferably from 1500 to 6000. By using a polyol with a molecular weight within this range, an elastic thread excellent in elongation, strength, elastic recovery force, and heat resistance can be easily obtained.

[0021] Next, as diisocyanates, aromatic diisocyanates such as diphenylmethane diisocyanate (hereinafter abbreviated as MDI), tolylene diisocyanate, 1,4-diisocyanatobenzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate are particularly suitable for synthesizing polyurethanes with high heat resistance and strength. Furthermore, as alicyclic diisocyanates, for example, methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate, cyclohexane 1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, and octahydro-1,5-naphthalene diisocyanate are preferred. Alicyclic diisocyanates are particularly effective in suppressing yellowing of polyurethane elastic yarns. These diisocyanates may be used alone or in combination.

[0022] The chain extender used in synthesizing the polyurethane is preferably at least one of a low molecular weight diamine and a low molecular weight diol, although it may also be one having both a hydroxyl group and an amino group in one molecule, such as ethanolamine.

[0023] Preferred low-molecular-weight diamines include, for example, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, hexamethylenediamine, p-phenylenediamine, p-xylylenediamine, m-xylylenediamine, p,p'-methylenedianiline, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methylpentamethylenediamine, and bis(4-aminophenyl)phosphine oxide. It is preferable to use one or more of these. Ethylenediamine is particularly preferred. The use of ethylenediamine facilitates the production of yarns with excellent elongation, elastic recovery, and heat resistance. A triamine compound capable of forming a crosslinked structure, such as diethylenetriamine, may be added to these chain extenders to an extent that the effect is not lost.

[0024] Typical low-molecular-weight diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate, and 1-methyl-1,2-ethanediol. It is preferable to use one or more of these. Ethylene glycol, 1,3-propanediol, and 1,4-butanediol are particularly preferred. The use of these diol-extended polyurethanes results in higher heat resistance and allows for the production of stronger yarns.

[0025] In the present invention, the molecular weight of the polyurethane is preferably in the range of 30,000 to 150,000 in terms of number average molecular weight, from the viewpoint of obtaining polyurethane elastic threads with high durability and strength. The molecular weight is measured by GPC and converted into polystyrene.

[0026] It is also preferable to use one or more types of terminal blocking agents in combination for the polyurethane. Preferred terminal blocking agents include monoamines such as dimethylamine, diisopropylamine, ethylmethylamine, diethylamine, methylpropylamine, isopropylmethylamine, diisopropylamine, butylmethylamine, isobutylmethylamine, isopentylmethylamine, dibutylamine, and diamylamine, monools such as ethanol, propanol, butanol, isopropanol, allyl alcohol, and cyclopentanol, and monoisocyanates such as phenyl isocyanate.

[0027] In the present invention, by incorporating (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant into a polyurethane elastic thread made of polyurethane having the basic structure described above, it is possible to impart excellent antibacterial properties to the thread.

[0028] Slightly water-soluble glass is generally a water-insoluble silicate glass, i.e., a glass that dissolves slowly in water and is produced by blending SiO2, the main raw material, with 30% or more by mass of P2O5 and / or B2O3. The slightly water-soluble glass used in the present invention is not limited to the typical slightly water-soluble glass primarily made of SiO2, but may also be a glass primarily made of P2O5 and / or B2O3, which can be vitrified independently, or may contain no SiO2. If the slightly water-soluble glass used in the present invention contains less than 30% by mass of P2O5 and / or B2O3, the elution of the (a) Group 1B element and / or Group 2B element ions will be poor during aqueous processing of polyurethane elastic yarns, such as dyeing, resulting in insufficient antibacterial effect.

[0029] In the present invention, the (a) Group 1B element and / or Group 2B element contained in the slightly water-soluble glass is preferably blended using oxides as raw materials. Examples of oxides of the (a) Group 1B element and / or Group 2B element include AgO, AgO, and AgO.3、 Examples include CuO, Cu2O, ZnO, and Au2O3. From the viewpoint of antibacterial properties, the lower the oxidation number of the (a) Group 1B element and / or Group 2B element, the more stable the substance, and Ag2O and CuO are particularly preferred. It is preferable that such oxides of the (a) Group 1B element and / or Group 2B element be blended in a total amount of 1 mass% or more in the phosphoric acid-based and / or boric acid-based glass powder with low water solubility, based on the raw materials.

[0030] This (a) phosphate-based and / or boric acid-based glass containing Group 1B and / or Group 2B elements can be used to produce polyurethane elastic threads with antibacterial properties by various methods. These (a) glass containing Group 1B and / or Group 2B elements may be used alone or in combination. The method for producing the glass is not particularly limited, but melt-quenching and sol-gel methods are preferred. In addition to the aforementioned components, trace components such as SrO, BaO, TiO2, ZrO2, Nb2O5, Cs2O, Rb2O, TeO2, BeO, GeO2, Bi2O3, La2O3, Y2O3, WO3, MoO3, or Fe2O3 can also be added to form a glass solid solution. Furthermore, clarifiers such as F, Cl, SO3, Sb2O3, SnO2, or Ce may be added.

[0031] The content of (a) the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element is preferably in the range of 0.1% by mass or more and 30% by mass or less, based on the total mass of the polyurethane elastic yarn. If the content of (a) the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element is less than 0.1% by mass, it may be difficult to obtain sufficient antibacterial properties when made into a fabric. It is more preferably 0.5% by mass or more. On the other hand, if the content exceeds 30% by mass, it may be undesirable in terms of deterioration of stretch properties or costs. It is preferably 10% by mass or less, and more preferably 5.0% by mass or less. Considering the balance between antibacterial properties, physical properties, and costs, a range of 1.0% by mass or more and 5.0% by mass or less is particularly preferred.

[0032] In addition, in the present invention, the (a) slightly water-soluble glass containing a Group 1B element and / or a Group 2B element preferably has an average primary particle diameter of 3.0 μm or less, more preferably 1.5 μm or less, from the viewpoint of preventing clogging of the spinning dope in the spinneret. Furthermore, from the viewpoint of dispersibility, if the average primary particle diameter is less than 0.05 μm, the cohesion increases, making it difficult to uniformly mix the particles in the spinning dope. Therefore, the average primary particle diameter is preferably 0.05 μm or more, more preferably 0.15 μm or more. The average primary particle diameter was measured using an electron microscope, for example, by using image processing to generate circles corresponding to the projected area of ​​primary particles located between two parallel lines in a fixed direction that sandwich the primary particles in a field of view of several tens of thousands of times. Then, the diameters of 20 particles were measured at random, and the values ​​in the top 5% (maximum value) and bottom 5% (minimum value) were removed based on the number of particles, and the average of the remaining 90% (18 values) was calculated. The particle size distribution is preferably such that the average primary particle size divided by the most frequent particle size (mode diameter) is 0.5 to 1.5, more preferably 0.8 to 1.2. Furthermore, the maximum particle size is preferably distributed within 2.0 times the average primary particle size, more preferably within 1.5 times.

[0033] In the present invention, it is preferable that (a) the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element be homogeneously distributed in the polyurethane. While various surfactants are known to be used as dispersants to achieve this, we have discovered that the use of nonionic surfactants is sufficient to homogeneously disperse (a) the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element in the polyurethane to obtain polyurethane elastic yarns with excellent spinnability, antibacterial properties, colorfastness, and stretchability. We have also discovered that the use of nonionic surfactants has a synergistic effect, particularly on antibacterial properties. On the other hand, ionic surfactants such as anionic surfactants, cationic surfactants, and anionic-cationic amphoteric surfactants may not exhibit antibacterial properties after aqueous processing steps, such as dyeing, which are essential for fabrics used in clothing.

[0034] Examples of nonionic surfactants in the present invention include polyoxyethylene alkyl ethers, alkyl monoglyceryl ethers, polyoxyethylene alkylamines, fatty acid sorbitan esters, and fatty acid diethanolamides. Among these, the hydrophilic portion of the surfactant is preferably an ether type, and is preferably at least one of an ethylene oxide polymer, a propylene oxide polymer, and a copolymer of ethylene oxide and propylene oxide. By including at least one of a terminal-modified derivative of an ethylene oxide polymer, a terminal-modified derivative of a propylene oxide polymer, and a terminal-modified derivative of a copolymer of ethylene oxide and propylene oxide as the nonionic surfactant, it is possible to improve spinnability and achieve good antibacterial properties. The so-called hydrophobic portion of the surfactant is the aforementioned terminally modified structure, and is preferably an alkyl group, a phenyl group, or a styrenated phenyl group. Specific examples of nonionic surfactants include polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene ethylphenol ether, polyoxyethylene propylphenol ether, polyoxyethylene styrenated phenyl ether, and polyoxyethylene sorbitol tetraoleate. More preferred is polyoxyethylene styrenated phenyl ether, and examples thereof include polyoxyethylene oxypropylene tristyrenated phenyl ether, polyoxyethylene oxypropylene distyrenated phenyl ether, polyoxyethylene oxypropylene monostyrenated phenyl ether, polyoxyethylene oxypropylene-2,4,6-tris(α,α-dimethylbenzyl)phenyl ether, polyoxyethylene oxypropylene-2,4-bis(α,α-dimethylbenzyl)phenyl ether, polyoxyethylene oxypropylene-2-mono(α,α-dimethylbenzyl)phenyl ether, polyoxyethylene oxypropylene-4-mono(α,α-dimethylbenzyl)phenyl ether, etc. Most preferred is when the number of moles of these styrene groups added has a distribution and a mixture of these is used.

[0035] In the present invention, it is preferable to use a quaternary ammonium salt antibacterial agent in combination. Controlling skin sensitization at an appropriate antibacterial level is particularly important for textile structures used in clothing, medical fabrics, and hygiene products. While slightly water-soluble glass containing Group 1B and / or Group 2B elements is completely inorganic, organic quaternary ammonium salt antibacterial agents tend to distribute on the surface of polyurethane elastic yarns, where quaternary ammonium elution proceeds more rapidly. This makes it easy to control the initial antibacterial performance immediately after production or various processing steps such as dyeing. On the other hand, since the elution of Group 1B and / or Group 2B elements from slightly water-soluble glass containing Group 1B and / or Group 2B elements proceeds slowly, adjusting the amount and particle size of the agent makes it easy to maintain the required level of antibacterial performance even after repeated washing or long-term aging. Thus, by incorporating antibacterial agents with different elution rates into polyurethane elastic yarns, it is possible to optimize antibacterial performance from the initial state to long-term aging. When a quaternary ammonium salt-based antibacterial agent is used in combination with the quaternary ammonium salt, the antibacterial activity varies depending on the chain length of the alkyl group in the ammonium ion. Stronger antibacterial activity is desirable. However, from the viewpoints of suppressing thermal decomposition due to heat exposure during the production of polyurethane elastic yarn and suppressing the ionic nature of the (a) Group 1B element and / or Group 2B element-containing glass with low water solubility that inhibits the elution of the (a) Group 1B element and / or Group 2B element, it is preferable to select a chain type such as an alkyl group, e.g., a group with a large chain length, i.e., a large number of carbon atoms. From this viewpoint, particularly preferred ammonium ions include didecyldimethylammonium ion and oleyltrimethylammonium ion. It is also preferable to consider the counter anion constituting the quaternary ammonium salt. These counter anions are typically provided by inorganic salts such as chlorides, bromides, and iodides, or organic salts such as carboxylates, sulfonates, and phosphates. Among these, carboxylates and sulfonates are preferred from the viewpoints of stability, such as discoloration and heat resistance, and improved breaking strength and elongation, with carboxylates being the most preferred.

[0036] Specific examples of salts having the above structure include didecyldimethylammonium carboxylates such as didecyldimethylammonium adipate, didecyldimethylammonium gluconate, and didecyldimethylammonium propionate; oleyltrimethylammonium carboxylates such as oleyltrimethylammonium adipate and oleyltrimethylammonium gluconate; and sulfonates such as didecyldimethylammonium trifluoride methylsulfonate, di-n-decyldimethylammonium trifluoromethanesulfonate, di-n-decyldimethylammonium pentafluoroethanesulfonate, n-hexadecyltrimethylammonium trifluoromethanesulfonate, and benzyldimethyl coconut oil alkyl ammonium pentafluoroethanesulfonate.

[0037] From the viewpoint of exhibiting antibacterial properties and maintaining a balance between discoloration and stretch properties, the quaternary ammonium salt antibacterial agent is preferably contained in an amount of 0.1% by mass to 5% by mass based on the total mass of the polyurethane elastic yarn. The polyurethane elastic yarn of the present invention may also contain various stabilizers, pigments, etc. For example, it is preferable that light fasteners, antioxidants, etc. include hindered phenol-based agents such as BHT and Sumitomo Chemical Co., Ltd.'s "Sumilizer" (registered trademark) GA-80, various benzotriazole-based and benzophenone-based agents such as Ciba-Geigy's "Tinuvin" (registered trademark), phosphorus-based agents such as Sumitomo Chemical Co., Ltd.'s "Sumilizer" (registered trademark) P-16, various hindered amine-based agents, various pigments such as iron oxide and titanium oxide, inorganic substances such as zinc oxide, cerium oxide, magnesium oxide, calcium carbonate, and carbon black, fluorine-based or silicone-based resin powder, metal soaps such as magnesium stearate, lubricants such as silicone and mineral oil, and various antistatic agents such as cerium oxide, betaine, and phosphate-based, and it is also preferable that these are reacted with the polymer. In order to further enhance durability, particularly against light and various nitrogen oxides, it is also preferable to use a nitrogen oxide scavenger such as HN-150 manufactured by Nippon Hydrazine Co., Ltd., a thermal oxidation stabilizer such as Sumilizer (registered trademark) GA-80 manufactured by Sumitomo Chemical Co., Ltd., or a light stabilizer such as Sumisorb (registered trademark) 300#622 manufactured by Sumitomo Chemical Co., Ltd.

[0038] Next, the method for producing the polyurethane elastic yarn of the present invention will be described in detail.

[0039] In the present invention, a polymer diol and a diisocyanate are used as the main starting materials, and the polyurethane spinning solution obtained therefrom is then dry-spun with (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant. When preparing the polyurethane spinning solution by mixing (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant, the nonionic surfactant is added in an amount ranging from 0.01 to 20 parts by mass per 100 parts by mass of the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element. More preferably, in the step of finely powdering (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element, the nonionic surfactant is premixed with the fine powder, and the fine powder is coated with the nonionic surfactant. The polyurethane solution and the polyurethane, which is the solute of the solution, may be produced by either melt polymerization or solution polymerization, or by other methods. However, solution polymerization is more preferable. In the case of solution polymerization, the generation of foreign matter such as gel in the polyurethane is small, spinning is easy, and it is easy to obtain elastic polyurethane threads with low fineness. Furthermore, solution polymerization has the advantage that the operation of making a solution can be omitted.

[0040] Polyurethanes particularly suitable for the present invention include those synthesized using PTMG having a molecular weight of 1500 or more and 6000 or less as the polymer diol, MDI as the diisocyanate, and at least one of ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, and hexamethylenediamine as the chain extender.

[0041] Polyurethane can be obtained by synthesizing the above-mentioned raw materials in a solvent such as dimethylacetamide (hereinafter abbreviated as DMAc), dimethyl sulfoxide (hereinafter abbreviated as DMF), dimethyl sulfoxide (hereinafter abbreviated as DMSO), n-methylpyrrolidinone (hereinafter abbreviated as NMP), or a solvent containing these as its main components. For example, particularly suitable methods include the so-called one-shot method, in which the raw materials are charged into such a solvent, dissolved, and heated to an appropriate temperature to react to form polyurethane, and a method in which a polymer diol and a diisocyanate are first melt-reacted, and then the reactant is dissolved in a solvent and reacted with the chain extender to form polyurethane.

[0042] When a diol is used as the chain extender, it is preferable to adjust the high-temperature melting point of the polyurethane to a range of 200°C or higher and 260°C or lower from the viewpoint of obtaining a polyurethane with excellent heat resistance. A typical method for achieving this is to control the types and ratios of polymer diol, MDI, and diol. When the molecular weight of the polymer diol is low, a polyurethane with a high high-temperature melting point can be obtained by relatively increasing the proportion of MDI. Similarly, when the molecular weight of the diol is low, a polyurethane with a high high-temperature melting point can be obtained by relatively decreasing the proportion of polymer diol.

[0043] When the molecular weight of the polymer diol is 1800 or more, in order to make the melting point on the higher temperature side 200° C. or higher, it is preferable to carry out the polymerization at a ratio of (number of moles of MDI) / (number of moles of polymer diol) of 1.5 or more.

[0044] In addition, in synthesizing such polyurethane, it is also preferable to use one or a mixture of two or more catalysts such as amine catalysts and organometallic catalysts.

[0045] Examples of amine catalysts include N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, triethylamine, N-methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,3-propanediamine, N,N,N',N'-tetramethylhexanediamine, bis-2-dimethylaminoethyl ether, N,N,N',N',N'-pentamethyldiethylenetriamine, tetramethylguanidine, and triethylene Examples of suitable amines include diamine, N,N'-dimethylpiperazine, N-methyl-N'-dimethylaminoethyl-piperazine, N-(2-dimethylaminoethyl)morpholine, 1-methylimidazole, 1,2-dimethylimidazole, N,N-dimethylaminoethanol, N,N,N'-trimethylaminoethylethanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylaminohexanol, and triethanolamine.

[0046] Examples of the organometallic catalyst include tin octoate, dibutyltin dilaurate, and dibutyl lead octoate.

[0047] The concentration of polyurethane in the polyurethane solution thus obtained is usually preferably in the range of 30% by mass or more and 80% by mass or less.

[0048] In the present invention, (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant are added to the polyurethane solution. Any method can be used to add (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant to the polyurethane solution. Typical methods include a method using a static mixer, a method using stirring, a method using a homomixer, and a method using a twin-screw extruder.

[0049] In the present invention, in order to improve antibacterial properties, it is preferable to incorporate (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element into the polyurethane elastic yarn in an amount of 0.5 to 10% by mass. To achieve this, it is necessary to evenly disperse (a) a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element in an amount of 0.5 to 10% by mass in an undiluted polyurethane spinning solution prior to spinning. Preferably, the above-mentioned (a) slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant are added to a polyurethane spinning solution containing N,N-dimethylformamide, N,N-dimethylacetamide, or the like as a solvent, and the mixture is stirred and mixed to disperse the mixture evenly. Specifically, it is preferable to first disperse (a) the slightly water-soluble glass containing Group 1B and / or Group 2B elements and a nonionic surfactant in a solvent such as N,N-dimethylformamide or N,N-dimethylacetamide to prepare a (a) slightly water-soluble glass dispersion containing Group 1B and / or Group 2B elements, and then mix this dispersion with the polyurethane spinning dope. Here, the solvent for the (a) slightly water-soluble glass dispersion containing Group 1B and / or Group 2B elements is preferably the same as that for the polyurethane solution, in order to ensure uniform addition to the polyurethane solution. Furthermore, when adding (a) the slightly water-soluble glass containing Group 1B and / or Group 2B elements to the polyurethane solution, the aforementioned chemicals such as light stabilizers and antioxidants, as well as pigments, may also be added simultaneously. Furthermore, in order to achieve antibacterial properties, it is preferable to premix the (a) slightly water-soluble glass containing Group 1B and / or Group 2B elements and a nonionic surfactant to prepare a dispersion, and then mix this dispersion with the polyurethane spinning dope.

[0050] In the present invention, it is also preferable to add a quaternary ammonium salt antibacterial agent to enhance antibacterial properties against various bacteria. To achieve this, the quaternary ammonium salt antibacterial agent is added to the polyurethane spinning dope before spinning, and then spinning is performed. The quaternary ammonium salt antibacterial agent can be added to the spinning dope by mixing it alone with the spinning dope, or by premixing it with the (a) slightly water-soluble glass containing a Group 1B element and / or a Group 2B element and a nonionic surfactant dispersion. The order of mixing is preferably a premix dispersion of the nonionic surfactant and the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element, followed by mixing the quaternary ammonium salt antibacterial agent, and then more preferably mixing this dispersion with the polyurethane spinning dope. The most preferred method for incorporating a quaternary ammonium salt antibacterial agent into the spinning dope is to mix the quaternary ammonium salt antibacterial agent alone with the spinning dope, independently of the dispersion in which a nonionic surfactant and a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element are premixed.

[0051] The spinning dope thus constituted can be subjected to dry spinning, wet spinning, or melt spinning, followed by winding, to obtain the polyurethane elastic yarn of the present invention. Among these, dry spinning is preferred from the viewpoint of enabling stable spinning of yarns of any fineness, from thin to thick.

[0052] The polyurethane elastic yarn of the present invention is not particularly limited in terms of fineness, cross-sectional shape, etc. For example, the cross-sectional shape of the yarn may be circular or flat.

[0053] The dry spinning method is not particularly limited, and spinning conditions may be appropriately selected to suit the desired properties and spinning equipment.

[0054] For example, the permanent set and stress relaxation of the polyurethane elastic yarn of the present invention are particularly susceptible to the influence of the speed ratio between the godet roller and the winder, and therefore it is preferable to determine this appropriately depending on the intended use of the yarn. That is, from the viewpoint of obtaining a polyurethane elastic yarn having the desired permanent set and stress relaxation, it is preferable to wind the yarn at a speed ratio between the godet roller and the winder in the range of 1.10 to 1.65.

[0055] The spinning speed is preferably 250 m / min or more from the viewpoint of improving the strength of the resulting polyurethane elastic yarn. [Example]

[0056] The present invention will be described in more detail using examples, but is not limited to these examples.

[0057] [NOx yellowing resistance] A sample card was made by winding 10 g of polyurethane elastic yarn onto a stainless steel plate. Using a Scott tester, this sample was exposed to a gas atmosphere containing NO2 gas at a specified concentration (7 ppm) for 50 hours. Before and after this exposure treatment, the "b" color was measured using a Color Master (D25 DP-9000 signal processor), and the degree of yellowing was evaluated based on the difference "Δb" between before and after treatment. The measured values ​​were calculated as the average of n = 3.

[0058] [Average primary particle size] The inorganic particles were photographed using a Hitachi S-800 field emission scanning electron microscope (FE-SEM) and analyzed using image processing software Image-Pro Version 4.0. The measurement parameters used were the projected area and equivalent circle diameter, and the number average was calculated for n = 20 particles per sample.

[0059] [Spinnability and yarn breakage frequency] The frequency of yarn breakage per solid content of the spinning solution was measured in terms of the number of yarn breakages / t.

[0060] [Preparation of Slightly Water-Soluble Glass Containing Group 1B Elements and / or Group 2B Elements] 24 mol% SiO2, 52 mol% B2O3, 10 mol% Na2O, 10 mol% TiO2, and 4 mol% Ag2O were mixed and melted at 800-1300°C. After cooling, the resulting glass was crushed and classified to particles with an average primary particle size of 10 μm or less. The resulting powder was then wet-milled to an average primary particle size of 0.8 μm, yielding a white powder. This was designated as slightly water-soluble silver glass 1.

[0061] In addition, 48 mol% of P2O5, 48 mol% of MgO, and 4 mol% of Ag2O were mixed and melted at 800 to 1300°C. After cooling, the resulting glass was crushed, classified into particles with an average primary particle size of 10 μm or less, and wet-milled to obtain a white powder with an average primary particle size of 0.8 μm. This was designated as slightly water-soluble silver glass 2.

[0062] [Creating knitted fabric for antibacterial evaluation] A 22 dtex polyurethane elastic yarn was stretched three times and covered with a polyamide processed yarn (trademark CUPE, manufactured by Toray Industries, Inc., 33 dtex, 26 filaments) as a sheath yarn at a twist rate of 800 T / m to produce S-twist and Z-twist single covered yarn (SCY).

[0063] Furthermore, the above S-twisted SCY was fed to yarn feeders 1 and 3 of a pantyhose knitting machine (manufactured by Lonati, 400 needles), and the above Z-twisted SCY was fed to yarn feeders 2 and 4 at a knitting tension of 1.0 g, and a knitted fabric was knitted. The content of polyurethane elastic yarn in the knitted fabric was 16%.

[0064] Next, the knitted fabric was dyed as follows to obtain a tights knitted fabric. (1) Presetting: Use a vacuum dryer, 90°C x 10 minutes (2) Dyeing: The fabric was dyed black using 2.0 owf% of the dye "Lanaset" (registered trademark) Black B manufactured by Chiba Specialty Chemicals Co., Ltd., at 90°C for 60 minutes. The pH during dyeing was adjusted with acetic acid and ammonium sulfate. (3) Finally, the fabric was softened and then set using a pantyhose setting machine (setting at 115°C for 10 seconds, drying at 120°C for 30 seconds).

[0065] [Washing Instructions] The washing method was based on the washing method manual established by the New Functionality Evaluation Council for Textile Products (JIS L0217:2020, Appendix 1, Washing Method 103). Specifically, a household electric washing machine specified in Appendix 1, Washing Method 103 of JIS L0217:2020 was used, and 40 milliliters of JAFET standard detergent (manufactured by the New Functionality Evaluation Council for Textile Products) was dissolved in 30 liters of water at 40°C to create a washing solution. 1 kg of sample laundry was placed in this washing solution. The washing was performed by washing for 5 minutes, spin-drying, rinsing for 2 minutes, spin-drying, rinsing for 2 minutes, and spin-drying, which was counted as one cycle.

[0066] [Antibacterial] The antibacterial test was conducted in accordance with the antibacterial testing procedure (JIS L1902:2015, bacterial solution absorption method) specified by the Japan Textile Evaluation Technology Council. X was the number of viable bacteria (units) after 18 hours of incubation on the untreated sample, and Y was the number of viable bacteria (units) after 18 hours of incubation on the test fabric. The antibacterial activity value was calculated to evaluate the antibacterial power. The measured value was calculated as the average of n = 3. In addition, the Textile Evaluation Technology Council, a non-profit organization, considers a product to be "effective" against bacteria when its antibacterial activity value against Staphylococcus aureus is 2.2 or higher.

[0067] [Strength, stress relaxation rate, permanent set rate, elongation of polyurethane elastic yarn] The strength, stress relaxation rate, permanent set rate and elongation of the polyurethane elastic yarn were measured by subjecting the sample yarn to a tensile test using an Instron 4502 tensile tester. These are defined below: That is, a 5 cm (L1) sample was stretched 300% at a tensile speed of 50 cm / min, and this was repeated five times. The stress at this fifth stretch was defined as (G1). Next, the 300% stretch was maintained for 30 seconds. The stress after this 30-second stretch was defined as (G2). Next, the stretch was allowed to recover, and the length of the sample yarn when the stress returned to 0 was defined as (L2). Finally, the sample yarn was stretched a sixth time until it broke. The stress at break was defined as (G3), and the length of the sample yarn at break was defined as (L3). Hereinafter, the above characteristics are given by the following formula: Strength [cN]=(G3) Stress relaxation rate [%] = 100 × ((G1) - (G2)) / (G1) Permanent distortion rate [%]=100×((L2)-(L1)) / (L1) Elongation [%] =100×((L3)-(L1)) / (L1) The tensile test was carried out three times and the average value was calculated.

[0068] [Example 1] PTMG with a molecular weight of 1800 and MDI were reacted at a molar ratio of 1:1.58 at 90°C for 2 hours to produce an isocyanate-terminated prepolymer, which was then dissolved in DMAc to prepare a 35% by mass prepolymer solution. Ethylenediamine and 1,2-propanediamine as chain extenders and diethylamine as a chain terminator were mixed in a mass ratio of 5:1:1, and the mixture was dissolved in DMAc to prepare a 35% by mass amine solution.

[0069] The prepolymer solution and the amine solution were mixed with stirring so that the molar ratio of isocyanate end groups to amine end groups was 1:1.02 to prepare a 35% by mass DMAC solution of polyurethane urea polymer. Next, a polyurethane solution (DuPont's "Methachlor" (registered trademark) 2462) produced by the reaction of t-butyldiethanolamine and methylene-bis-(4-cyclohexyl isocyanate) was mixed with a 2:1 (mass ratio) condensation polymer of p-cresol and divinylbenzene (DuPont's "Methachlor" (registered trademark) 2390) as an antioxidant to prepare a 35% by mass DMAC solution. 96 parts by mass of the polyurethane urea polymer DMAC solution and 4 parts by mass of the antioxidant solution were mixed to prepare polymer solution A1. Next, a slightly water-soluble silver glass 1 containing a Group 1B element and / or a Group 2B element and a nonionic surfactant, polyoxyethylene alkyl ether (Ionet MO, manufactured by Sanyo Chemical Industries, Ltd.), were dispersed in DMAc using a homomixer to produce dispersion B1 (35% by mass). Polymer solutions A1 and B1 were then uniformly mixed at 97% by mass and 2% by mass to produce spinning solution D1. This was dry-spun at 720 m / min with a godet roller / winder speed ratio of 1.3 to produce a 200 g wound polyurethane yarn with a 22 dtex, 2 filament count, and a content of 2% by mass of the slightly water-soluble glass antibacterial agent and 0.1% by mass of the nonionic surfactant.

[0070] The obtained polyurethane elastic yarn was measured for spinnability, NOx yellowing resistance, and stretchability. Furthermore, knitted fabrics for evaluation were prepared and antibacterial properties were measured. The results of these evaluations are shown in Tables 1 and 2.

[0071] [Example 2] to [Example 8] Using the same method as in Example 1, polyurethane elastic yarn was obtained with a composition consisting of the antibacterial agent component and surfactant component shown in Table 1. The obtained polyurethane elastic yarn was measured for spinnability, NOx yellowing resistance, and stretch properties. Furthermore, knitted fabrics for evaluation were prepared and antibacterial properties were measured. The results of various evaluations are shown in Tables 1 and 2.

[0072] [Example 9] and [Example 10] A polyurethane elastic yarn was obtained in the same manner as in Example 1, except that the composition consisted of the antibacterial agent component, surfactant component, and quaternary ammonium salt-based antibacterial agent shown in Table 1. The quaternary ammonium salt-based antibacterial agent was added and dissolved after mixing polymer solution A1 with a dispersion containing slightly water-soluble silver glass 1 and a nonionic surfactant to prepare a spinning solution. The resulting polyurethane elastic yarn was measured for spinnability, NOx yellowing resistance, and stretchability. Furthermore, a knitted fabric for evaluation was prepared, and its antibacterial properties were measured. The results of the various evaluations are shown in Tables 1 and 2.

[0073] [Comparative Example 1] As in Example 1, polymer solution A1 was dry-spun to obtain a 200g wound body of 22 dtex, 2-filament polyurethane yarn. The resulting polyurethane elastic yarn was evaluated for spinnability, NOx yellowing resistance, and stretchability. Furthermore, a knitted fabric for evaluation was prepared, and its antibacterial properties were measured. The evaluation results are shown in Tables 1 and 2.

[0074] [Comparative Example 2] to [Comparative Example 8] Using the same method as in Example 1, polyurethane elastic yarn was obtained with a composition consisting of the antibacterial agent component and surfactant component shown in Table 1. The obtained polyurethane elastic yarn was measured for spinnability, NOx yellowing resistance, and stretch properties. Furthermore, knitted fabrics for evaluation were prepared and antibacterial properties were measured. The results of various evaluations are shown in Tables 1 and 2.

[0075] [Table 1]

[0076] [Table 2]

Claims

1. A polyurethane elastic yarn whose main constituent is a polyurethane whose main starting materials are a polymer diol and a diisocyanate, and which contains (a) 0.5 mass % or more and 5.0 mass % or less of a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element, and (b) a nonionic surfactant.

2. 2. The polyurethane elastic yarn according to claim 1, wherein the average primary particle size of (a) is 3.0 μm or less.

3. 3. The polyurethane elastic yarn according to claim 1, wherein (a) is a glass having a slightly water solubility containing silver and / or a glass having a slightly water solubility containing copper.

4. 4. The polyurethane elastic yarn according to claim 1, wherein (b) is a polyoxyethylene alkyl ether.

5. 5. The polyurethane elastic yarn according to claim 1, which contains a quaternary ammonium salt antibacterial agent.

6. A method for producing an elastic polyurethane yarn, comprising: mixing a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element into a spinning dope containing polyurethane, the starting materials of which are polymer diol and diisocyanate, in an amount of 0.5 to 5.0 mass % based on the total amount of the polyurethane and the slightly water-soluble glass; mixing a nonionic surfactant in an amount of 0.01 to 20 mass parts based on 100 mass parts of the slightly water-soluble glass containing a Group 1B element and / or a Group 2B element; and dry-spinning the spinning dope.

7. 7. The method for producing polyurethane elastic yarn according to claim 6, wherein a slightly water-soluble glass containing a Group 1B element and / or a Group 2B element is mixed as a dispersion into a spinning dope containing polyurethane whose main starting materials are a polymer diol and a diisocyanate.

8. The method for producing polyurethane elastic yarn according to claim 6 or 7, wherein the Group 1B element and / or Group 2B element is silver and / or copper.

9. The method for producing polyurethane elastic yarn according to any one of claims 6 to 8, wherein (b) is polyoxyethylene alkyl ether.

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