JP3930750B2 - Process for producing ion-radiating polyurethane elastic fiber and ion-radiating polyurethane elastic fiber - Google Patents

Description

【０１０８】
【表２】

【０１０９】
【比較例２】
比較例１と同様に紡糸反応を行い、ポリウレタン弾性体はヘッドに設置したギアポンプにより計量、加圧され、フィルターでろ過後、径０．４ｍｍ×２ホールのノズルから毎分１．３３ｇの速度で長さ６ｍの紡糸筒内に吐出させ、ガイドで収束させた後、油剤を付与しながら６００ｍ／分の速度でポリウレタン弾性繊維を巻き取った。
【０１１０】
ヘッド温度は１９２℃とした。２２ｄＴ２フィラメントのポリウレタン弾性繊維が得られた。単繊維径は３４μｍであった。ノズルパックにおけるフィルターは４００メッシュ金網を支持層として平均粒径６０μｍのガラスビーズを最終ろ過層としたもので、有効ろ過径は約１０μｍである。
【０１１１】
吐出直後のポリウレタン弾性繊維のイソシアネート基含有率は、０．４６重量％であった。紡糸結果及び得られたポリウレタン弾性繊維の性能（糸強度、伸度、繊度斑、カバリング糸切れ）を表３に、イオン発生量を表４に記載した。
【０１１２】
【比較例３】
実施例２と同じイオン放射性鉱物ＡとＭＳＴ−２９のスラリーをプレミキサーでＯＨ末端プレポリマーに混合、分散させながらＮＣＯ末端プレポリマーとともに実施例２と同様の反応機に注入した。スラリーの注入量は０．４３ｇ／分とした。比較例２と同様のヘッドにポリウレタン弾性体を導き、２２ｄＴ２フィラメントのポリウレタン弾性繊維を巻き取った。単繊度径は３４μｍであった。１日紡糸後、フィルター昇圧が早い為、紡糸を中断した。
【０１１３】
紡糸結果及び得られたイオン放射性鉱物Ａを含むポリウレタン弾性繊維の性能（糸強度、伸度、繊度斑、カバリング糸切れ）を表３に、イオン発生量を表４に記載した。糸中のイオン放射性鉱物Ａの含有量は１重量％であった。吐出直後のポリウレタン弾性繊維のイソシアネート基含有率は、０．４２重量％であった。
【０１１４】
【比較例４】
比較例３と同様に紡糸を行うに当たってノズルパックのフィルターを２００メッシュ金網＋平均粒径１００μｍのガラスビーズに変えた。フィルターの有効ろ過径は１７μｍである。単繊維径は３４μｍであった。
【０１１５】
鉱物粉末の添加量が多いとフィルター昇圧が早く、糸の伸度、強力が低下した。
【０１１６】
吐出直後のポリウレタン弾性繊維のイソシアネート基含有率は、０．４９重量％であった。紡糸結果及び得られたイオン放射性鉱物Ｃを含むポリウレタン弾性繊維の性能（糸強度、伸度、繊度斑、カバリング糸切れ）を表３に、イオン発生量を表４に記載した。糸中のイオン放射性鉱物Ｃの含有量は１重量％であった。
【０１１７】
【表３】

【０１１８】
【表４】

【０１１９】
【発明の効果】
本発明によれば、天然放射性元素含有無機鉱物粉末が混合されたイオン放射性ポリウレタン弾性繊維を小ロットで効率よく製造する方法が提供できる。
【図面の簡単な説明】
【図１】 実施例２で用いたポリウレタン弾性繊維用反応機を説明するための図。
【図２】 実施例３で用いたポリウレタン弾性繊維用反応機に設置される
注入装置Ａ、Ｂを説明するための図。
【図３】 実施例２で用いたプレミキサーを説明するための図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyurethane elastic fiber and a method for producing the same. More specifically, the present invention relates to an ion radioactive polyurethane elastic fiber containing a natural radioactive element-containing inorganic mineral powder and a method for efficiently producing the ion radioactive polyurethane elastic fiber in a small lot.
[0002]
[Prior art]
Various products in which various inorganic mineral powders are mixed with polyurethane elastic fibers are disclosed. For example, Japanese Patent Application No. 56-093119 discloses a polyurethane elastic fiber mixed with zinc oxide powder. Japanese Patent Application No. 57-165469 discloses a method of adding an inorganic mineral powder after passing through a dispersing machine such as an attritor, and Japanese Patent Application No. 3-206412 discloses a polyurethane elastic fiber mixed with an inorganic antibacterial agent. It is disclosed.
[0003]
In recent years, for the purpose of promoting health by negative ions in the air, various mineral powders capable of generating ions have been attached to fiber products or contained in fibers. Examples of minerals used include tourmaline powder (JP-A-10-212663), inorganic porous powder (JP-A-2001-279574), igneous rock powder (JP-A-11-81032), and the like.
[0004]
Examples of substances that effectively generate a large number of ions include minerals containing natural radioactive elements such as thorium and uranium.
[0005]
In addition to polyurethane elastic fiber, synthetic fiber or artificial fiber (Japanese Patent Application No. 5-11348), as a fiber added with a natural radioactive element-containing inorganic mineral powder (hereinafter also referred to as “ion radioactive mineral”) having ion radiation ability, Acrylic fibers (Japanese Patent Application No. 1-332325) are disclosed. However, there is no disclosure regarding a method for producing polyurethane elastic fibers containing an ion radioactive mineral.
[0006]
Since polyurethane elastic fibers for special applications, such as those containing ion radioactive minerals, do not have a very large capacity on the market, technology for producing them in small lots is required. In addition, degradation of fiber performance due to mixing of mineral powder must be avoided.
[0007]
In the case of producing a yarn in which an ion radioactive mineral is mixed with polyurethane elastic fiber by a dry spinning method, it is conceivable to add and mix the ion radioactive mineral to a stock solution immediately before spinning in order to cope with small lot production. However, it is not easy to uniformly mix an ion radioactive mineral with a high-viscosity spinning stock solution, and facilities such as a mixing tank, a stirrer, and a stock solution supply are required.
[0008]
In addition, since polyurethane elastic fibers are used after being stretched 3 to 4 times in the post-processing stage, yarn breakage occurs during processing if there are defects due to foreign matter in the yarn. Therefore, filtration of the stock solution is an important item in spinning polyurethane elastic fibers, and it is a good quality product to filter and remove large particle size additives and high viscosity gel particles in the stock solution before spinning. It is an indispensable condition to obtain. It is generally desirable that the required filtration accuracy is smaller than 1/3 of the single fiber diameter.
[0009]
In the case of the dry spinning method of polyurethane elastic fibers, if the single yarn fineness is increased, the surface area is relatively decreased and the evaporation rate of the solvent is lowered. Therefore, the spinning speed must be lowered. Therefore, the single yarn fineness is generally about 11 dtex (hereinafter, dtex is “dT”, where dT is the weight (g) per 10,000 m of yarn). Since the diameter of the 11dT polyurethane elastic fiber is about 34 μm, the required filtration accuracy is desirably about 12 μm or less.
[0010]
The particle size of commercially available ion radioactive minerals generally has a maximum diameter of about 3 to 5 μm. Although it is possible to further pulverize ion radioactive minerals on the market, they contain radioactive elements and are not desirable due to problems such as dust scattering. On the other hand, when the average particle size is 0.1 μm or less, secondary agglomeration is likely to occur, and on the contrary, dispersion failure may be caused. In general, when filtering a highly viscous liquid mixed with hard powders such as minerals, the filter pressurization speed must be set to 2 to 3 times the maximum diameter of the added powder for fast filter pressurization for industrial production. Do not peel. As a result, it is difficult to knead the ion radioactive mineral into the polyurethane elastic fiber by the dry spinning method.
[0011]
First, in order to prevent filter clogging, it is necessary to set a larger effective filtration diameter. As a result, the removal of the gel particles becomes insufficient, and the yarn obtained by spinning as it is has not only the occurrence of defects due to mineral particles but also the defects due to gel particles, and single yarn breakage occurs when it is stretched in the subsequent process. Cause it to occur.
[0012]
The polyurethane elastic fiber by the dry spinning method is used as a multifilament in which single yarns of about 11 dT are bonded together as described above. For this reason, for example, when one single yarn breaks with a 22dT2 filament, the portion becomes half the fineness, which directly leads to a product defect.
[0013]
On the other hand, in recent years, the use of polyurethane elastic fibers produced by a melt spinning method characterized by a soft tightening feeling when used in clothing is increasing compared to polyurethane elastic fibers obtained by a dry spinning method.
[0014]
The following three methods are known as melt spinning methods for polyurethane elastic fibers.
(1) Method of melt spinning a polyurethane elastic chip
(2) A method of spinning by mixing a polyisocyanate compound after melting a polyurethane elastic chip
(3) A so-called prepolymer obtained by reacting a polyol and a diisocyanate and a low molecular weight diol are reacted to synthesize a polyurethane elastic body, without solidifying it. spinning The reactive spinning method (3) is less costly than the methods (1) and (2) because there is no process for handling polyurethane elastic chips, and an isocyanate compound is added to the polyurethane elastic fiber polymer to be spun. When the raw material blending ratio is adjusted so as to leave about 0.4 to 1%, the heat resistance is improved by the chain extension reaction due to the residual isocyanate group after spinning, which is a preferable method. In addition, a low molecular weight diol is reacted with a part of the prepolymer in advance by the method (3) and injected into the reactor as a prepolymer having excess OH groups.
[0015]
Since the present inventors do not use a solvent, the single yarn fineness can be increased, and generally high quality polyurethane mixed with ion radioactive minerals by a melt spinning method produced with a monofilament rather than a fused multifilament at 78 dT or less. A method for efficiently producing elastic fibers in a small lot was studied.
[0016]
In the production of polyurethane elastic fibers by the melt spinning method, the following methods are conceivable for mixing ion radioactive minerals.
(1) Making a masterbatch with high concentration of ion radioactive mineral in polyurethane elastic, mixing with ordinary chips and melting
However, when making this masterbatch, there is a drawback that the reaction system is contaminated if it is added before the synthesis of the elastic body. Spots due to poor mixing and spinning failure are likely to occur.
(2) A method of mixing ion radioactive minerals at a high concentration in the polyisocyanate compound added during spinning
This method is suitable for the production of small lots, but since polyisocyanate compounds react with moisture in the air and change their properties, it is impractical to take them out of reaction tanks or mixing tanks for storage and reuse. Absent. The prepared mixture of ion radioactive mineral and polyisocyanate compound must be used up in full and washed equipment.
[0017]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and provides a polyurethane elastic fiber mixed with a natural radioactive element-containing inorganic mineral powder capable of producing a small lot and having good fiber performance, and a method for producing the same. Is an issue.
[0018]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventor has obtained an ion-radiating polyurethane elastic material capable of obtaining a maximum particle size when producing a polyurethane elastic fiber mixed with a natural radioactive element-containing inorganic mineral powder by melt spinning. A natural radioactive element-containing inorganic mineral powder having a fiber diameter of 1/9 or less of the fiber is added to a dispersion medium, preferably a stable dispersion medium that does not react with moisture in the air, and the slurry contains a natural radioactive element. Efficient production of ion-radiating polyurethane elastic fibers in a small lot by continuously injecting and spinning the polyurethane elastic material so that the inorganic mineral powder content is 0.2 to 5% by weight. The present inventors have found what can be done and have completed the present invention.
[0019]
That is, the present invention is as follows.
(1) A method for producing an ion radioactive polyurethane elastic fiber comprising a natural radioactive element-containing inorganic mineral powder,
In a polyurethane elastic fiber reactor, a polyurethane elastic material, a slurry containing a natural radioactive element-containing inorganic mineral powder having a maximum particle size of 1/9 or less of the single fiber diameter of the ion-radiating polyurethane elastic fiber, and a dispersion medium Continuously and quantitatively injected,
A polyurethane elastic body is obtained by uniformly stirring the polyurethane elastic material and the slurry, melt-spun without solidifying the polyurethane elastic body, and contains 0.2 to 5% by weight of the natural radioactive element-containing inorganic mineral powder. A production method for obtaining ion-radiating polyurethane elastic fibers.
(2) The polyurethane elastic body raw material is an isocyanate-terminated prepolymer and a low molecular weight diol obtained by reacting the first polyol and the first diisocyanate, or the first polyol and the first diisocyanate are reacted. The method for producing an ion-radiating polyurethane elastic fiber according to (1), which is a hydroxyl group-terminated prepolymer obtained by reacting an isocyanate-terminated prepolymer and a low molecular weight diol, a second polyol, and a second diisocyanate.
(3) The dispersion medium is a polyether-modified polysiloxane obtained by adding one or both of ethylene oxide and propylene oxide to one selected from the group consisting of dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane. A method for producing an ion-radiating polyurethane elastic fiber according to 1) or (2).
(4) The dispersion medium is a polyol having an average molecular weight of 650 to 6000 consisting of one or a combination of two or more selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols (1) or ( 2) The manufacturing method of the ion radiation polyurethane elastic fiber of 2).
(5) When the radiation intensity of the natural radioactive element-containing inorganic mineral powder is A becquerel / g and the amount added to the polyurethane elastic fiber is B% by weight, A × B is 30 or more (1) The manufacturing method of the ion radiation polyurethane elastic fiber in any one of-(4).
(6) An ion radioactive polyurethane elastic fiber containing a natural radioactive element-containing inorganic mineral powder, wherein the single yarn fineness of the ionic polyurethane elastic fiber is 17 dtex or more, and the natural radioactive element-containing inorganic mineral powder is: An ion-radiating polyurethane elastic fiber having a content of 0.2 to 5% by weight and a maximum particle size of 1/9 or less of the single fiber diameter of the ionic polyurethane elastic fiber.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is an ion radioactive polyurethane elastic fiber containing a natural radioactive element-containing inorganic mineral powder (hereinafter also referred to as “ion radioactive mineral”), and the single yarn fineness of the ionic polyurethane elastic fiber is 17 dtex or more. The natural radioactive element-containing inorganic mineral powder has a content of 0.2 to 5% by weight and a maximum particle size of 1/9 or less of the single fiber diameter of the ionic polyurethane elastic fiber. It is an ion-radiating polyurethane elastic fiber.
[0021]
In order to obtain the ion-radiating polyurethane elastic fiber of the present invention, the polyurethane elastic fiber reactor is equipped with a polyurethane elastic material and a natural fiber having a maximum particle size of 1/9 or less of the single fiber diameter of the ion-emitting polyurethane elastic fiber. Continuously and quantitatively injecting a radioactive element-containing inorganic mineral powder and a slurry containing a dispersion medium,
The polyurethane elastic material and slurry are uniformly stirred to obtain a polyurethane elastic body, and a production method is used in which the polyurethane elastic body is melt-spun without solidifying.
[0022]
As the polyurethane elastic material, those generally used for the production of thermoplastic polyurethane elastic materials may be used. Specifically, (1) only polyurethane elastic chip; (2) combination of polyurethane elastic chip and polyisocyanate compound having isocyanate group; (3) isocyanate-terminated prepolymer and low molecular weight diol or hydroxyl-terminated prepolymer 3 patterns of combinations;
[0023]
Preferably, an isocyanate-terminated prepolymer obtained by reacting the first polyol and the first diisocyanate (3) (hereinafter referred to as “NCO-terminated prepolymer”) and a low molecular weight diol are used, or an NCO-terminated prepolymer. It is preferable to use a hydroxyl group-terminated prepolymer (hereinafter referred to as “OH-terminated prepolymer”) obtained by reacting a low molecular weight diol, a second polyol, and a second diisocyanate.
[0024]
Examples of polyurethane elastic body chips include thermoplastic polyurethane elastic bodies obtained by polymerizing polybutylene adipate having a number average molecular weight of about 2000, diphenylmethane diisocyanate, and 1,4-butanediol.
[0025]
Examples of the polyisocyanate compound include those obtained by reacting a difunctional or trifunctional glycol having a number average molecular weight of about 1000 such as polytetramethylene glycol and polycaprolactone with an excess of diphenylmethane diisocyanate.
[0026]
As the first polyol used for the NCO-terminated prepolymer, the following polyols having a number average molecular weight of 650 to 6000 are preferably used. Polyether glycols such as polytetramethylene ether glycol, polyethylene adipate, polybutylene adipate, polyesters such as polycaprolactone, polycarbonate diols such as polyhexamethylene carbonate, and mixtures thereof. Among these, polytetramethylene ether glycol and polyethylene adipate having a number average molecular weight of about 2000 are preferably used.
[0027]
As the first diisocyanate used in the NCO-terminated prepolymer, diisocyanates having a molecular weight of 500 or less are preferably used. For example, P, P′-diphenylmethane diisocyanate, tolylene diisocyanate and the like can be mentioned. P, P′-diphenylmethane diisocyanate is preferably used.
[0028]
Examples of the low molecular diol used for the OH-terminated prepolymer include glycols having a molecular weight of 500 or less. Examples include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, bishydroxyethoxybenzene, and the like. Among these, 1,4-butanediol is preferably used.
[0029]
Examples of the second polyol and the second diisocyanate used in the OH-terminated prepolymer include the same as the first polyol and the first diisocyanate used in the NCO-terminated prepolymer. When an NCO-terminated prepolymer and an OH-terminated prepolymer are used as the polyurethane elastic material, the first polyol for the NCO-terminated prepolymer and the first diisocyanate are the second polyol for the OH-terminated prepolymer and the second diisocyanate. May be the same or different.
[0030]
When using NCO-terminated prepolymers and OH-terminated prepolymers as polyurethane elastic materials, polyol, diisocyanate, low molecular weight diol, etc. are reacted to form each prepolymer before being injected into the polyurethane elastic fiber reactor. deep.
[0031]
The NCO-terminated prepolymer can be obtained, for example, by charging diisocyanate in a tank equipped with a warm water jacket and a stirrer, then injecting polyol while stirring and stirring at 80 ° C. for 1 hour under nitrogen purge. During this reaction, various chemicals (such as ultraviolet absorbers, antioxidants and light stabilizers) for improving weather resistance, heat oxidation resistance, yellowing resistance, etc. may be added.
[0032]
UV absorbers include 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzo Examples thereof include benzotriazole-based ultraviolet absorbers such as triazole and 2- (2-hydroxy-3,5-bisphenyl) benzotriazole.
[0033]
Antioxidants include 3,9-bis (2- (3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl) -2,4, 8,10-tetraoxaspiro (5 ・ 5) undecane, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid, pentaerythrityl-tetrakis [3- And hindered phenolic antioxidants such as (3,5-di-t-butyl-4-hydroxyphenyl) propionate].
[0034]
Examples of light stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and dimethyl succinate-1. And hindered amine light stabilizers such as-(2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine condensate.
[0035]
The obtained NCO-terminated prepolymer is injected into a polyurethane elastic fiber reactor using a jacketed gear pump (for example, KAP-1 from Kawasaki Heavy Industries, Ltd.).
[0036]
For the OH-terminated prepolymer, diisocyanate is charged into a tank equipped with a warm water jacket and a stirrer, and then a polyol is injected while stirring and stirred under a nitrogen purge at 80 ° C. for 1 hour, and then a low molecular weight diol is injected and stirred. Can be obtained. In this reaction, the above-mentioned various chemicals for improving weather resistance, heat oxidation resistance, yellowing resistance and the like may be added. The obtained OH-terminated prepolymer is injected into a polyurethane elastic fiber reactor using a gear pump with a jacket (for example, KAP-1 of Kawasaki Heavy Industries, Ltd.).
[0037]
When a low molecular weight diol is used as a chain extender instead of an OH-terminated prepolymer, it is dehydrated in advance and then injected into the reactor with a variable-capacity plunger pump with a jacket linked with a gear pump for NCO-terminated prepolymer injection.
[0038]
The ratio of the NCO-terminated prepolymer and the OH-terminated prepolymer is appropriately adjusted by the rotation ratio of the injection gear pump. The ratio of NCO-terminated prepolymer to low molecular weight diol is achieved by changing the plunger pump capacity. The ratio of the NCO-terminated prepolymer to the OH-terminated prepolymer or the low molecular weight diol is preferably such that 0.3% or more of NCO groups remain in the spun polyurethane elastic fiber (yarn). When the NCO group is contained in an excess of 0.3% or more, physical properties such as high elongation and heat resistance are improved by the chain elongation reaction after spinning. The amount contained in the NCO-based yarn is preferably 1% or less. If it exceeds 1%, the viscosity of the molten polymer becomes low and spinning becomes difficult.
[0039]
The content of NCO groups in the spun yarn is measured as follows. After the spun yarn (about 1 g) was dissolved in a dibutylamine / dimethylformamide / toluene solution, excess dibutylamine was reacted with NCO groups in the sample, and the remaining dibutylamine was titrated with hydrochloric acid to contain NCO groups. Calculate the amount.
[0040]
In the slurry containing the ion radioactive mineral and the dispersion medium, the ion radioactive mineral and the dispersion medium are sufficiently mixed in advance with a mixer equipped with a hot water jacket. The slurry may contain an appropriate dispersant that does not react with the isocyanate group or accelerate the reaction.
[0041]
As the dispersion medium, polyether-modified polysiloxane obtained by adding one or both of ethylene oxide and propylene oxide to dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane is easy to mix in the polyurethane elastic melt, and It is preferably used because it can be expected to prevent the elastic fibers from sticking to each other during winding.
[0042]
The polyether-modified polysiloxane having a viscosity of 200 to 10,000 centipoise at 30 ° C. is preferable from the viewpoint of the injection stability of the mixture and the stability against separation during storage.
[0043]
A normal measurement method is used for measuring the viscosity. For example, the viscosity is measured at 30 ° C. using a B-type viscometer of Tokyo Keiki Co., Ltd.
[0044]
Since this slurry does not react with moisture in the air, it can be prepared in batches for several lots at a time and stored in a metal can or the like. If there is a risk of absorbing moisture, vacuum drying may be performed before use.
[0045]
The dispersion medium suitably used other than the polyether-modified polysiloxane is a polyol used as a raw material for the polyurethane elastic body.
[0046]
More specifically, a number consisting of one or a combination of two or more selected from the group consisting of polyether polyols such as polytetramethylene glycol, polyester polyols such as polybutylene adipate and polycarbonate polyols such as polyhexamethylene carbonate. A polyol having an average molecular weight of 650 to 6000.
[0047]
The number of functional groups per molecule of polyol is preferably 1.8 to 2.5. In the case of a polyol having only a functional group of 1.8 or less per molecule, the elongation of the polyurethane polymer molecule is inhibited, so that the strength tends to be lowered. Also, depending on the polyol content in the dispersion medium, if the content of polyol having 3 or more functional groups is too large and the average number of functional groups is 2.5 or more, the melt viscosity of the polyurethane elastic body is abnormal. Is undesirably high, and insoluble matter is generated in the polymer. When polyols are used as the dispersion medium, they react with the isocyanate groups in the polyurethane elastic material in the reactive spinning machine and are incorporated into the polyurethane polymer. Even if the amount of the dispersion medium is large, the spinning process and yarn quality are adversely affected. Is preferred. In this case, it is preferable to lower the injection ratio of the low molecular weight diol or OH-terminated prepolymer in the polyurethane elastic material.
[0048]
The type of polyol may be the same as or different from the polyol used in each prepolymer reaction, but polyols having a melting point of 25 ° C. or less are particularly suitable for ease of handling.
[0049]
The polyol preferably has a viscosity of 200 to 10000 centipoise at 30 ° C., more preferably 300 to 7000 centipoise.
[0050]
The polyol as the dispersion medium preferably has a number average molecular weight of about 650 to 6000, which is generally used for polyurethane elastic material. A polyol having a number average molecular weight of 650 or less is not preferable because it reduces the crystallinity of the hard segment of the polyurethane elastic body and causes a decrease in heat resistance. Those having a number average molecular weight of 6000 or more have a high viscosity, and dispersion of ion radioactive minerals tends to be insufficient.
[0051]
Other liquid substances such as silicon oil can be injected as a dispersion medium, but this is not preferable because it causes phase separation during spinning with a polyurethane elastic body and causes fineness of polyurethane elastic fibers. Also, plasticizers such as dioctyl butarate can be used, but it is not preferable because it remains in the yarn after spinning and tends to reduce the strength of the yarn.
[0052]
Examples of the natural radioactive element-containing inorganic mineral powder in the present invention include monazite, xenite, and the like, but are not particularly limited as long as the mineral contains a natural radioactive element such as thorium or uranium that emits ions.
[0053]
In the present invention, the inorganic mineral powder is not a mineral powder containing only natural radioactive elements, but is a spontaneously polarizable mineral such as ceramics capable of emitting far-infrared rays or tourmaline disclosed in Japanese Patent Application Laid-Open No. 2000-191319. What was mixed and pulverized with powder or the like has a synergistic effect and is more preferable.
[0054]
As for the ratio of the ion radioactive mineral to the dispersion medium, it is preferable that the concentration of the ion radioactive mineral is high as long as there is fluidity. However, if the content of the ion radioactive mineral in the slurry is more than 70% by weight, the viscosity is too high and injection is performed. Prone to defects. On the contrary, when the ratio of the dispersion medium is too large, the viscosity of the slurry is lowered, and separation of the ion radioactive mineral is likely to occur in the cylinder of the injector, which is not preferable. Accordingly, the content of the ion radioactive mineral in the slurry is preferably 10 to 70% by weight. The slurry has a viscosity of 100 to 10,000 at 30 ° C. Cm Poise is preferred.
[0055]
A slurry is obtained by mixing the ion radioactive mineral and the dispersion medium. As a method of continuously and quantitatively injecting the slurry into the polyurethane elastic fiber reactor into which the polyurethane elastic material is injected, the piston of the cylinder is pushed by a ball screw driven by a stepping motor with a speed reducer, and a fixed amount of slurry A device for continuously injecting is suitable for small-lot production. Although it is necessary to change the capacity of the cylinder depending on the amount of slurry injected and the size of the product lot, 500 to 3000 ml is suitable.
[0056]
In addition, the ion radioactive polyurethane elastic fiber of the present invention has an ion radioactive mineral content in the elastic fiber of 0.2 to 5% by weight. If the content is less than 0.2% by weight, the ion generation ability of the product using the ion-radiating polyurethane elastic fiber is insufficient, and if it is more than 5% by weight, the fiber performance tends to deteriorate, which is not preferable. . The content of the ion radioactive mineral in the elastic fiber is adjusted by adjusting the injection ratio of the slurry with respect to the polyurethane elastic material and various chemicals used as necessary. Specifically, from the amount of polyurethane elastic material and various chemicals supplied to the reactor, the ion radioactive mineral is 0.2 to 5% by weight based on the total amount of polyurethane elastic material and slurry. Determine the amount of slurry to be injected into the reactor.
[0057]
When using NCO-terminated prepolymer and OH-terminated prepolymer as the polyurethane elastic material, a method of redispersing the ion radioactive mineral slurry into the OH-terminated prepolymer with a premixer immediately before injection in order to dissociate the secondary aggregation of particles. Is more preferred.
[0058]
Moreover, it is also possible to produce continuously by installing two injection devices and performing a switching operation. The amount of slurry injected can be adjusted by changing the motor rotation speed with an inverter or the like. It is preferable to install a heat retaining device such as a hot water jacket in the cylinder because the amount of injection can be further stabilized.
[0059]
The polyurethane elastic material and the slurry are uniformly stirred while continuously injecting the polyurethane elastic material and the slurry into the reactor for the polyurethane elastic fiber at a constant ratio, thereby obtaining an ion-radiating mineral-containing polyurethane elastic material. In the present invention, when an NCO-terminated prepolymer and / or an OH-terminated prepolymer is used as the polyurethane elastic material, it is possible to inject while premixing the slurry in either prepolymer.
[0060]
The reactor for the polyurethane elastic fiber used in the present invention may be a reactor used for ordinary polyurethane elastic fiber melt spinning, a reaction vessel for melting the polyurethane elastic material, and the polyurethane elastic material. One having a nozzle or the like that spins without solidifying is used.
[0061]
In the production method of the present invention, when the radiation intensity of the ion radioactive mineral is A becquerel / g and the amount added to the polyurethane elastic fiber is B wt%, A × B is preferably 30 or more.
[0062]
The radiation intensity of the ion radioactive mineral is preferably 60 to 370 becquerel / g from the viewpoint of the ion generation ability of the finished product. The amount of ion radioactive mineral added to the polyurethane elastic fiber is preferably 0.2 to 5% by weight as described above.
[0063]
Radiation intensity is measured by measuring the spectrum of gamma rays generated from the sample ion radioactive mineral, classifying the spectrum into uranium series and thorium series based on the wavelength and intensity, and calculating the total number of atomic decays per second. To do.
[0064]
The average residence time in the reactor varies depending on the type of the reactor. The average residence time is determined by the following formula (1).
[0065]
[Expression 1]
Reactor volume / Polyurethane elastic body discharge x Specific gravity of polyurethane elastic body (1)
Generally, it takes about 1 hour when using a cylindrical reactor, and about 5 minutes when using a twin screw extruder.
[0066]
The obtained ion-radiating mineral-containing polyurethane elastic body is melt-spun without solidifying to obtain an ion-radiating polyurethane elastic fiber. As the melt spinning method, a normal melt spinning method may be used, and there is no particular limitation.
[0067]
By using the method for producing polyurethane elastic fibers of the present invention, polyurethane elastic fibers mixed with ion radioactive minerals as additives can be efficiently produced even in small lot production.
[0068]
In addition, it is preferable that the maximum particle diameter of an ion radioactive mineral is 1/9 or less of the single fiber diameter of the ion radioactive mineral polyurethane elastic fiber obtained. The preferred single yarn fineness of the ion radioactive mineral polyurethane elastic fiber is 17 dT or more, and the single fiber diameter is preferably 42 μm or more. In addition, when the single fiber diameter is 100 μm or more, the filament cooling during spinning becomes slow and the adhesion between filaments due to poor cooling becomes strong. Therefore, the single fiber diameter is preferably 42 to 100 μm. In addition, the maximum particle size of the ion radioactive mineral is preferably smaller than 1/3 of the filter diameter of the filter installed immediately before the spinning nozzle of the polyurethane elastic fiber reactor. Specifically, 5 μm or less is preferable. The average particle size of the ion radioactive mineral is preferably 0.1 to 1.0 μm.
[0069]
In the present invention, the single fiber diameter of the ion radioactive mineral polyurethane elastic fiber can be measured by taking and measuring an enlarged photograph of the elastic fiber using a microscope VH8000 manufactured by Keyence Corporation.
[0070]
It is preferable that the water content of the ion radioactive mineral is small. If necessary, drying is preferably performed before mixing.
[0071]
The maximum particle size and average particle size of the ion radioactive mineral are measured as follows. The particle size distribution data is created using a Shimadzu SALD-2000A tester, and the diameter at which the amount of particles smaller than the diameter is 50% is defined as the average particle diameter, and the diameter at 99% is defined as the maximum particle diameter.
[0072]
In the present invention, the number average molecular weight is measured, for example, as follows.
(1) Obtain OH groups in the sample by acetic anhydride esterification. First, OH groups in a sample are esterified with acetic anhydride, the remaining acetic anhydride is decomposed and converted to acetic acid, the remaining amount is obtained by titration, and the consumed acetic acid content is calculated to obtain OH groups.
(2) Obtain the acid value of the sample by titration.
(3) Calculate the average molecular weight as bifunctional.
[0073]
【Example】
The present invention will be specifically described below. In addition, all the parts in the following mixing | blending are a weight part.
[0074]
The measuring method of each physical property in a present Example is as follows.
[0075]
Next, a method for measuring each physical property will be described below. The same measurement was performed in the examples described later. A numerical value is an average value of each 10 cheeses.
(Thread strength) Measurement was performed at a grasping length of 5 cm and an elongation rate of 500 cm / min using a tensile tester with a constant elongation rate in an environment of a temperature of 20 ° C. and a humidity of 65%.
(Elongation) Under a temperature of 20 ° C. and a humidity of 65%, using a tensile tester with a constant elongation rate, the elongation (A) until cutting is determined by measuring at a grasping length of 5 cm and an elongation rate of 500 cm / min. Similarly, the elongation (B) until cutting is determined by measuring at a grasping length of 10 cm and an elongation rate of 1000 cm / min. Elongation is calculated | required by following formula (2).
[0076]
[Expression 2]
Elongation (%) = (B−A) / 5 × 100 (2)
(Fineness unevenness) Measured for 5 minutes under conditions of temperature 25 ° C, humidity 60%, using an Evestester of Twelvegar Worcester, with a polyurethane elastic fiber feed rate of 50 m / min and a winding speed of 100 m / min. The fineness variation rate (CV%) was determined.
(Filter pressurization) The pressure difference was measured with a pressure gauge installed between the gear pump of the spinning head and the filter, and the pressure difference after the lapse of a predetermined time from the start of the test spinning was investigated.
(Spun yarn breakage) The total number of yarn breakage of 16 spindles during the spinning period was measured.
(Covering yarn breakage) The obtained polyurethane elastic fiber was stretched 3.0 times, and the number of yarn breakage was measured when it was set on a covering test machine made of 48 spindles of Kataoka machine for 4 days at a yarn speed of 25 m.
(Method for measuring the amount of ion generation of polyurethane elastic fiber cheese) One side of the square box is a perforated plate, the top is covered with a lid, and the ion measuring machine IC-1000 of Universal Planning Co., Ltd. is attached to the opposite side of the perforated plate. The sample cheese was put in a box-type measuring device having a capacity of 12 L and the lid was covered, and the ion measuring device sucked the air in the box and measured the number of ions in the air. The amount of ions was also measured for polyurethane elastic fiber cheese to which no ion radioactive mineral was added as a blank.
[0077]
[Example 1]
(Slurry adjustment)
Polyether-modified dimethylpolysiloxane (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., MST-29, number average molecular weight 2800, viscosity at 30 ° C. 3900 Cm Poise) 50 parts were charged into a tank equipped with a stirrer and a jacket, and 50 parts of ion radioactive mineral A was gradually added while stirring. When stirring was continued for 1 hour, a uniform slurry was obtained. The mixing temperature was 60 ° C. The viscosity of the slurry is 4000 at 30 ° C. Cm It was a poise.
[0078]
The ion radioactive mineral A is composed of zirconium oxide as a main component, monazite blended, fired and pulverized, and has an average particle size of 0.8 μm and a maximum particle size of 5 μm. The radiation intensity was 330 becquerel / g.
(Adjustment of polyurethane elastic material)
The following NCO-terminated prepolymer and OH-terminated prepolymer were used as raw materials for polyurethane elastic body synthesis.
[0079]
44.6 parts of diphenylmethane diisocyanate (hereinafter referred to as “MDI”) is charged into an 80 ° C. reaction kettle sealed with nitrogen gas, and an ultraviolet absorber (2- (3,5-di-t-amyl-2-hydroxyphenyl) is added. ) Benzotriazole: 20%), antioxidant (3,9-bis (2- (3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl ) -2,4,8,10-tetraoxaspiro (5 · 5) undecane: 50%), light stabilizer (bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate: 30%) An NCO-terminated prepolymer was obtained by injecting 100 parts of a polyester diol having a number average molecular weight of 2000 synthesized from ethylene glycol, propylene glycol and adipic acid while stirring 2.2 parts of the mixture. It was.
[0080]
In an 80 ° C reaction kettle sealed with another nitrogen gas MDI 25 parts, NCO end pre-po
100 parts of the polyester diol used in the production of the polymer was injected and reacted for 1 hour, and 28 parts of 1,4-butanediol was further added and reacted to obtain an OH-terminated prepolymer.
(Injection of slurry and production of ion-radiating polyurethane elastic fiber) Continuous NCO-terminated prepolymer and OH-terminated prepolymer at a ratio of 1: 0.42 in a cylindrical reactor for polyurethane elastic fiber with a capacity of 1000 ml having a stirring blade (NCO-terminated prepolymer: 14.72 g / min, OH-terminated prepolymer: 6.18 g / min). The slurry containing the ion radioactive mineral obtained above is put into a cylinder (65 mm in diameter, 300 mm in length, 1000 ml in capacity) of an injection device that moves the piston of the cylinder with a ball screw driven by a motor with a speed reducer, and pushed by the piston. Simultaneous injection at a rate of 43 g / min. The average residence time in the reactor is about 1 hour, and the reaction temperature is 190 ° C.
[0081]
The polyurethane elastic body containing the ion radioactive mineral was introduced into two spinning heads having 8 nozzles without solidifying. The spinning head temperature was kept at 188 ° C. The polyurethane elastic body is measured and pressurized by a gear pump installed on the head, filtered through a filter, and discharged from a nozzle of 0.5 mm diameter and 1 hole into a 6 m long spinning tube at a rate of 1.33 g / min ( The total amount discharged from the nozzle: 21.33 g / min) was wound at a speed of 600 m / min while applying an oil agent to obtain 22 dT ion-radiating polyurethane elastic fibers (yarns). The discharge amount of the polyurethane elastic body was adjusted by the rotation speed of the gear pump. The single fiber diameter was 49 μm.
[0082]
The filter in the nozzle pack uses a 300-mesh wire mesh as a support layer and glass beads with an average particle size of 90 μm as the final filtration layer, and the effective filtration diameter is about 15 μm. The filtration area of this filter is about 12cm ² Met.
[0083]
It took 2 hours for the added ion radioactive mineral concentration to stabilize, but smooth switching was possible. After operating for 2 days, slurry injection was stopped and returned to the original operation. The spinning results and the performance (yarn strength, elongation, fineness unevenness, covering yarn breakage) of the polyurethane elastic fiber containing the ion radioactive mineral A are shown in Table 1. The mineral content in the wound yarn was about 1.0% by weight.
[0084]
The isocyanate group content of the polyurethane elastic fiber immediately after discharge was determined by dissolving the obtained yarn in a dibutylamine / dimethylformamide solution and titrating the remaining dibutylamine with a hydrochloric acid solution. As a result, it was 0.45% by weight.
(Prototype of test knitted fabric using ion-radiating polyurethane elastic fiber)
First, using the obtained ion-radiating polyurethane elastic fiber stretched 3.0 times as a core yarn and using a polyamide 78T68 filament false twisted yarn as a sheath yarn, S twist and Z twist 650 times / m S covering yarn and Z covering yarn were prepared.
[0085]
Using the Nagata KT Super 4 knitting machine with 4 stitches, with 4 active yarn feeders, the S covering yarn and Z covering yarn obtained above are alternately knitted to steam relax the knitted fabric. After drying, only the toe was sewn to obtain a test knitted fabric.
[0086]
In addition, the ion generation amount of the obtained test knitted fabric was measured as follows. One knitted fabric is covered with a cylindrical foot mold having many holes, and is put into a vertical cylindrical container having an inner diameter of 200 mm and a height of 1000 mm with an intake hole on the lower surface. The air in the container was sucked through the knitted fabric from the upper part of the cylindrical container with an ion measuring machine IC-1000 of Universal Planning Co., Ltd., and the ion concentration was measured.
[0087]
Table 2 shows the measurement results of the ion generation amount of the ion-radiating polyurethane elastic fiber and the test knitted fabric.
[0088]
[Example 2]
The slurry used in Example 1 was put into a cylinder having an internal volume of 3000 ml and extruded with a piston at a rate of 1.29 g / min. 1 (NCO-terminated prepolymer: 11.11 g / min, OH-terminated prepolymer: 5.93 g / min) and discharged to obtain a 22 dT yarn. The single fiber diameter was 49 μm. The spinning results and the performance (yarn strength, elongation, fineness unevenness, covering yarn breakage) of the polyurethane elastic fiber containing the ion radioactive mineral A are shown in Table 1. The content of the ion radioactive mineral A in the yarn was 3% by weight. The isocyanate group content of the polyurethane elastic fiber was 0.49% by weight.
[0089]
The spinning condition was good and there were few covering yarn breaks in the trial spinning. The spinning situation was further improved by passing the premixer.
[0090]
Spinning results and obtained ion radioactive minerals A Table 1 shows the performance (yarn strength, elongation, fineness unevenness, covering yarn breakage) of the polyurethane elastic fiber containing. A test knitted fabric was prepared using the obtained yarn in the same manner as in Example 1, and the measurement results of the ion generation amount of the ion-radiating polyurethane elastic fiber and the knitted fabric are shown in Table 2.
[0091]
In addition, the outline | summary of the reactor for polyurethane elastic fibers used for the manufacturing method of the polyurethane elastic fiber of Example 2 is shown in FIG. An outline of a premixer for mixing and dispersing the OH-terminated prepolymer and the slurry is shown in FIG.
[0092]
The premixer shown in FIG. 3 is operated at 3600 rpm with the casing inner diameter φ80 mm, the rotor diameter φ79 mm × 21 L, the inner volume approximately 18 ml, and the outer periphery of the casing cooled with a water jacket. The rotor has many protrusions that cause shearing and stretching by high-speed rotation and disperse.
[0093]
[Example 3]
(Slurry adjustment)
60 parts of 3-methyl-1,5-pentanediol adipate (manufactured by Kuraray Co., Ltd., Kurapol P2010, number average molecular weight 2000, viscosity 3700 centipoise at 30 ° C.) was charged into a tank equipped with a stirrer and jacket, and the ions were stirred. 40 parts of radioactive mineral B was gradually added. When stirring was continued for 1 hour, a uniform slurry was obtained. The mixing temperature was 60 ° C. The viscosity of the slurry is 3000 at 30 ° C. Cm It was a poise.
[0094]
The ion radioactive mineral B is composed of tourmaline as a main component, monazite blended and pulverized, and has an average particle size of 0.6 μm and a maximum particle size of 3 μm. The radiation intensity was 200 becquerels / g.
(Slurry injection and production of ion-radiating polyurethane elastic fiber)
The same prepolymer as the polyurethane elastic material was used as in Example 1.
[0095]
The polyurethane elastic yarn was spun in the same manner as in Example 2 except that two sets of equipment (injection apparatuses A and B) for injecting the slurry containing the ion radioactive mineral B prepared as described above were installed and switched by a valve. (Total discharge amount from nozzle: 21.33 g / min).
[0096]
Specifically, the injection device B The slurry was put into a cylinder of the reactor, and the slurry was poured into a premixer containing an OH-terminated prepolymer, mixed and dispersed, and mixed with an NCO-terminated prepolymer into a cylindrical reactor for polyurethane elastic fibers at 0.54 g / min. Injection was carried out at a speed to perform spinning. The injection ratio of NCO-terminated prepolymer to OH-terminated prepolymer was 1: 0.41 (NCO-terminated prepolymer: 14.75 g / min, OH-terminated prepolymer: 6.05 g / min).
[0097]
After spinning the polyurethane elastic yarn for 2 days, the cylinder of the injection device B is filled with the slurry containing the ion radioactive mineral B, switched from the injection device A to B, and the spinning is continued for 2 days to continue the 22dT ion-radiation polyurethane elastic fiber ( Thread). The single fiber diameter was 49 μm.
[0098]
In addition, the schematic of injection apparatus A and B installed in the reactor for polyurethane elastic fibers used in Example 3 in FIG. 2 is shown.
[0099]
The spinning results and the performance (yarn strength, elongation, fineness unevenness, covering yarn breakage) of the polyurethane elastic fiber containing the ion radioactive mineral B obtained are shown in Table 1. The content of the ion radioactive mineral B in the yarn was 1.0% by weight. The isocyanate group content of the polyurethane elastic fiber was 0.43% by weight.
[0100]
A test knitted fabric was prepared using the obtained yarn in the same manner as in Example 1, and the measurement results of the ion generation amount of the ion-radiating polyurethane elastic fiber and the knitted fabric are shown in Table 2.
[0101]
[Example 4]
(Slurry adjustment)
Charge 60 parts of 3-methyl-1,5-pentanediol adipate (manufactured by Kuraray Co., Ltd., Kurapol P2010, number average molecular weight 2000, viscosity 3700 centipoise at 30 ° C.) into a tank equipped with a stirrer and jacket, 40 parts of radioactive mineral C was gradually added. When stirring was continued for 1 hour, a uniform slurry was obtained. The mixing temperature was 60 ° C. The viscosity of the slurry is 3000 at 30 ° C. Cm It was a poise.
[0102]
The ion radioactive mineral C is mainly composed of tourmaline, monazite blended and pulverized, and has an average particle size of 0.6 μm and a maximum particle size of 3 μm. The radiation intensity was 80 becquerel / g.
(Slurry injection and production of ion-radiating polyurethane elastic fiber)
The same prepolymer as the polyurethane elastic material was used as in Example 1.
[0103]
The slurry prepared above is put into a cylinder with an internal volume of 1000 ml, extruded with a piston at a speed of 0.16 g / min, added to a premixer containing an OH-terminated prepolymer, and mixed and dispersed together with an NCO-terminated prepolymer. The same reactor as in Example 1 was injected (NCO-terminated prepolymer: 14.91 g / min, OH-terminated prepolymer: 6.26 g / min) to obtain a 22 dT yarn. The single fiber diameter was 50 μm. The spinning results and the performance of the obtained polyurethane elastic fiber (yarn strength, elongation, fineness unevenness, covering yarn breakage) are shown in Table 1. A test knitted fabric was prepared using the obtained yarn in the same manner as in Example 1, and the amount of ions generated from the yarn and the knitted fabric was measured. The results are shown in Table 2. The content of ion radioactive mineral C in the yarn was 0.3% by weight. The isocyanate group content of the polyurethane elastic fiber was 0.51% by weight.
[0104]
[Comparative Example 1]
Polyurethane elastic fibers were melt-spun in the same manner as in Example 1 except that the slurry containing the ion radioactive mineral was not injected into the polyurethane elastic material. The single fiber diameter was 50 μm.
[0105]
The isocyanate group content of the polyurethane elastic fiber immediately after discharge was 0.45% by weight. The polyurethane elastic fiber immediately after winding was low in strength, but improved to 1.61 CN / dT after being left in the room for 1 day. (CN is sentinton)
The spinning results and the performance of the obtained polyurethane elastic fiber (yarn strength, elongation, fineness unevenness, covering yarn breakage) are shown in Table 1.
[0106]
A test knitted fabric was prepared using the obtained yarn in the same manner as in Example 1, and the amount of ions generated from the yarn and the knitted fabric was measured. The results are shown in Table 2.
[0107]
[Table 1]

[0108]
[Table 2]

[0109]
[Comparative Example 2]
The spinning reaction was carried out in the same manner as in Comparative Example 1, and the polyurethane elastic body was measured and pressurized by a gear pump installed on the head, filtered through a filter, and then passed through a nozzle having a diameter of 0.4 mm × 2 holes at a rate of 1.33 g / min. After discharging into a 6 m long spinning tube and converging with a guide, the polyurethane elastic fiber was wound up at a speed of 600 m / min while applying an oil agent.
[0110]
The head temperature was 192 ° C. A 22dT2 filament polyurethane elastic fiber was obtained. The single fiber diameter was 34 μm. The filter in the nozzle pack has 400 mesh wire mesh as a support layer and glass beads having an average particle size of 60 μm as the final filtration layer, and the effective filtration diameter is about 10 μm.
[0111]
The isocyanate group content of the polyurethane elastic fiber immediately after discharge was 0.46% by weight. The spinning results and the performance of the obtained polyurethane elastic fiber (yarn strength, elongation, fineness unevenness, covering yarn breakage) are shown in Table 3, and the amount of ions generated is shown in Table 4.
[0112]
[Comparative Example 3]
The slurry of the same ion radioactive mineral A and MST-29 as in Example 2 was mixed with and dispersed in the OH-terminated prepolymer with a premixer and injected into the same reactor as in Example 2 together with the NCO-terminated prepolymer. The amount of slurry injected was 0.43 g / min. A polyurethane elastic body was led to the same head as in Comparative Example 2, and a 22dT2 filament polyurethane elastic fiber was wound up. The single fineness diameter was 34 μm. After spinning for 1 day, spinning was interrupted because the filter pressurization was fast.
[0113]
The spinning results and the performance (yarn strength, elongation, fineness unevenness, covering yarn breakage) of the polyurethane elastic fiber containing the ion radioactive mineral A are shown in Table 3, and the ion generation amount is shown in Table 4. The content of the ion radioactive mineral A in the yarn was 1% by weight. The isocyanate group content of the polyurethane elastic fiber immediately after discharge was 0.42% by weight.
[0114]
[Comparative Example 4]
In performing spinning in the same manner as in Comparative Example 3, the filter of the nozzle pack was changed to 200 mesh wire mesh + glass beads having an average particle diameter of 100 μm. The effective filtration diameter of the filter is 17 μm. The single fiber diameter was 34 μm.
[0115]
When the amount of mineral powder added was large, the pressure of the filter increased quickly, and the yarn elongation and strength decreased.
[0116]
The isocyanate group content of the polyurethane elastic fiber immediately after discharge was 0.49% by weight. The spinning results and the performance (yarn strength, elongation, fineness unevenness, covering yarn breakage) of the polyurethane elastic fiber containing the ion radioactive mineral C are shown in Table 3, and the ion generation amount is shown in Table 4. The content of the ion radioactive mineral C in the yarn was 1% by weight.
[0117]
[Table 3]

[0118]
[Table 4]

[0119]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing efficiently the ion radioactive polyurethane elastic fiber with which the natural radioactive element containing inorganic mineral powder was mixed can be provided with a small lot.
[Brief description of the drawings]
1 is a diagram for explaining a polyurethane elastic fiber reactor used in Example 2. FIG.
FIG. 2 is installed in the polyurethane elastic fiber reactor used in Example 3
The figure for demonstrating injection | pouring apparatus A and B. FIG.
3 is a diagram for explaining a premixer used in Example 2. FIG.

Claims (6)

Polyurethane elastic fiber for reactor, a polyurethane elastomer material, quantitatively injecting the slurry continuously including natural radioactive element-containing inorganic mineral powders and dispersing medium, uniformly stirring the polyurethane elastic material and slurry Te to obtain a polyurethane elastomer, and melt spinning without solidifying the polyurethane elastomer, met production method to obtain an ion-radioactive polyurethane elastic fiber the natural radioactive element-containing inorganic mineral powders containing 0.2 to 5 wt% And
An ion-radiating polyurethane elastic fiber for producing the ion-radiating polyurethane elastic fiber so that the maximum particle size of the natural radioactive element-containing inorganic mineral powder is 1/9 or less of the single fiber diameter of the obtained ion-radiating polyurethane elastic fiber. Manufacturing method.   The polyurethane elastic material is an isocyanate-terminated prepolymer and a low molecular weight diol obtained by reacting the first polyol and the first diisocyanate, or an isocyanate terminal obtained by reacting the first polyol and the first diisocyanate. The method for producing ion-radiating polyurethane elastic fibers according to claim 1, which is a hydroxyl group-terminated prepolymer obtained by reacting a prepolymer, a low molecular weight diol, a second polyol, and a second diisocyanate.   The dispersion medium is a polyether-modified polysiloxane obtained by adding one or both of ethylene oxide and propylene oxide to one selected from the group consisting of dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane. 3. A method for producing an ion-radiating polyurethane elastic fiber according to 2.   3. The ion according to claim 1, wherein the dispersion medium is a polyol having an average molecular weight of 650 to 6000 comprising one or a combination of two or more selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols. Manufacturing method of radioactive polyurethane elastic fiber.   5. The A × B is 30 or more, wherein the radiation intensity of the natural radioactive element-containing inorganic mineral powder is A becquerel / g and the amount added to the polyurethane elastic fiber is B wt%. The manufacturing method of the ion radiation polyurethane elastic fiber in any one. The method for producing ion-radiating polyurethane elastic fibers according to any one of claims 1 to 5, wherein the dispersion medium has a viscosity at 30 ° C of 200 to 10,000 centipoise .

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