JP2004225221A - Ammonia gas-catching conjugated fiber, separator for alkaline battery and alkaline battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ammonia gas-catching conjugated fiber capable of catching the ammonia gas sufficiently and a separator for an alkaline battery and the alkaline battery. <P>SOLUTION: This ammonia gas-catching conjugated fiber is provided by covering a core component consisting of a solid state catching organic resin capable of catching the ammonia gas after melting and solidifying the same, with a sheath component consisting of a fiber-forming resin, and capable of catching the ammonia gas in ammonia water. The separator for the battery consists of a fiber sheet containing the ammonia gas-catching conjugated fiber. The alkaline battery is equipped with the fiber sheet containing the ammonia gas-catching conjugated fiber as the separator for the alkaline battery. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ammonia gas capturing composite fiber, an alkaline battery separator, and an alkaline battery. In particular, ammonia effluent dissolved in alkaline solution in fields such as chemical plants, feed / fertilizer manufacturing plants, food manufacturing plants, etc., livestock / hay animal treatment plants, and self-discharge of alkaline batteries. The present invention relates to an ammonia gas capturing composite fiber, an alkaline battery separator, and an alkaline battery that can be used for capturing ammonia gas dissolved in the caustic alkaline electrolyte.
[0002]
[Prior art]
Ammonia gas is a major malodorous component, and in recent years, development of advanced ammonia gas deodorizers has been demanded along with improvement of living standards. Chemical deodorization methods (chemical cleaning methods, ion exchange methods, direct combustion methods, catalytic oxidation methods, oxidant methods, ozone deodorization methods, deodorant / deodorant methods), as conventional methods for removing odorous components including ammonia gas components, Examples include adsorption deodorization method and biological deodorization method. In these methods, an ion exchange method, an oxidant method, an adsorption method, a biological deodorization method, etc. are mainly used as a method for removing ammonia gas in the liquid.
[0003]
In any of these methods, ammonia gas can be removed when the liquid is neutral or acidic, but cannot be removed when the liquid is alkaline. Even if it can be made, unreacted substances and ions remain in the waste liquid. Therefore, a separate method for removing these residual ions is necessary.
[0004]
On the other hand, as a battery that suppresses self-discharge by capturing ammonia gas in the battery, a "battery in which an acid is enclosed in a container formed of a gas-permeable material and this container is built in" has been proposed. (Patent Document 1). Since this battery can capture ammonia gas, it can be expected to have an excellent self-discharge suppressing action. However, since the liquid acid is actually enclosed in a container formed of a gas permeable material, the gas permeable material is damaged during battery manufacture, and the liquid acid is likely to flow out or leak. In addition to not being able to achieve the purpose of capturing ammonia gas, the neutralization reaction proceeds with an alkaline solution that is an electrolytic solution, and thus it has been difficult to stably produce a battery having a desired capacity.
[0005]
[Patent Document 1]
JP 2001-85048 A (Claims, paragraph numbers 0011 to 0012)
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide an ammonia gas capturing composite fiber, an alkaline battery separator and an alkaline battery that can sufficiently capture ammonia gas.
[0007]
[Means for Solving the Invention]
The ammonia gas-trapping composite fiber of the present invention is “a core component made of a solid-trapping organic resin capable of trapping ammonia gas after being melted and solidified is covered with a sheath component made of a fiber-forming resin, It is an “ammonia gas capturing composite fiber” characterized in that it can capture ammonia gas. Such an ammonia gas-trapping composite fiber has been found that the solid-trapping organic resin as the core component is less susceptible to external influences, and is in a fiber state and has a large surface area, so that it can sufficiently capture ammonia gas. is there. Further, since ammonia gas is trapped in the ammonia gas trapping composite fiber, there is no adverse effect such as new ions remaining.
[0008]
The solid capture organic resin is an ethylene copolymer composed of one or more copolymerization components selected from unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, and phosphoric acid and ethylene. Then, ammonia gas can be captured by acid-base reaction, so there is no possibility of re-release of ammonia gas. Moreover, since the ion exchange capacity is large, a large amount of ammonia gas can be captured with a small volume. It is even cheaper.
[0009]
The solid capture organic resin is a propylene copolymer comprising one or more copolymer components selected from unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, and phosphoric acid, and propylene. Then, ammonia gas can be captured by acid-base reaction, so there is no possibility of re-release of ammonia gas. Moreover, since the ion exchange capacity is large, a large amount of ammonia gas can be captured with a small volume. It is even cheaper.
[0010]
When the solid capture organic resin is composed of a polymer obtained by graft polymerization of one or more components selected from an unsaturated carboxylic acid, an unsaturated carboxylic acid derivative, and an unsaturated carboxylic acid anhydride, particularly capturing ammonia gas. Excellent in properties. These solid capture organic resins are considered not to be decomposed by heat during spinning.
[0011]
When the fiber-forming resin is made of a polyolefin-based resin, it has excellent gas permeability and chemical resistance. Therefore, it is immersed in an ammonia gas-dissolved solution (especially an alkali solution) to efficiently capture only ammonia gas. be able to.
[0012]
When the core component is discontinuous in the fiber axis direction, the ammonia gas-dissolved solution (especially an alkaline solution) is captured from the cut surface even if the ammonia gas-capturing composite fiber is cut for use as a short fiber. Since it is difficult to reach the core component made of an organic resin and is not easily affected by the ammonia gas-dissolved solution, it is possible to capture ammonia gas efficiently.
[0013]
In the fiber cross section, if there are two or more core components, even if an ammonia gas dissolved solution (particularly an alkali solution) reaches a certain core component, the core component can no longer capture the ammonia gas. The ammonia gas can be captured by the remaining core component.
[0014]
In the fiber cross-section, if two or more kinds of core components differing in cross-sectional area are provided, the amount of core components present in the fiber can be increased. Therefore, the amount of trapped ammonia gas per fiber can be increased. Can do a lot.
[0015]
In the fiber cross section, if the largest core component having the largest cross-sectional area is located at the center, the amount of the core component present in the fiber can be further increased. More can be done.
[0016]
The ammonia gas capturing composite fiber of the present invention can be suitably used for capturing ammonia gas dissolved in an alkaline solution.
[0017]
The separator for alkaline batteries of the present invention is composed of a fiber sheet containing the ammonia gas-trapping composite fiber. Therefore, it has a large surface area and can sufficiently capture ammonia gas that causes self-discharge in alkaline batteries. Moreover, since it can arrange | position between a positive electrode and a negative electrode, ammonia gas can be capture | acquired efficiently. In other words, since the separator for alkaline batteries is located between the positive electrode and the negative electrode, which are ammonia gas moving paths, the ammonia gas is efficiently captured, the shuttle effect by the ammonia gas is suppressed, and the self-discharge is efficiently performed. Can be suppressed.
[0018]
The alkaline battery of the present invention comprises a fiber sheet containing the ammonia gas-trapping composite fiber as an alkaline battery separator. Since this battery separator has a large surface area and can sufficiently capture ammonia gas, it is an alkaline battery that is difficult to self-discharge. Moreover, since the neutralization reaction does not occur with the alkaline solution that is the electrolytic solution, the alkaline battery can exhibit a desired capacity. Furthermore, since a separator that has been conventionally used is provided, and a special member is not provided, the installation place is not limited, which is suitable for manufacturing.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The ammonia gas trapping composite fiber of the present invention (hereinafter sometimes simply referred to as “capturing composite fiber”) includes a core component made of a solid trapping organic resin capable of trapping ammonia gas after being melted and solidified. Ammonia gas can be captured.
[0020]
The solid capturing organic resin as the core component is not particularly limited as long as it can capture ammonia gas after being melted and solidified. That is, after the organic resin is heated to the melting point or higher and cooled and solidified, it is measured whether the ammonia gas can be trapped by the following method. It is a solid trapping organic resin capable of trapping ammonia gas.
[0021]
In the present invention, “capable of capturing ammonia gas” means that the concentration of ammonia gas in the ammonia water is measured by the following operation using a measuring apparatus 1 as shown in FIG. It means that it has the effect of reducing the ammonia gas concentration. The preferable degree of trapping ammonia gas is such that the decrease in ammonia gas concentration is 0.1 mmol or more per gram of solid capture organic resin, more preferably 0.15 mmol or more per gram of solid capture organic resin.
Record
(1) Ammonia water having a concentration of 12 mmol / L is prepared, and 125 mL of this ammonia water is put into a 250 mL Erlenmeyer flask 1a (with glass stopper 1b).
(2) Put the sample 1c into a cylindrical glass container (size: 30 mm in diameter, 20 mm in height) whose top is open so that ammonia water does not enter the glass container and can come into contact with the air in the Erlenmeyer flask 1a. After the glass container is put into the Erlenmeyer flask 1a, the glass stopper 1b is attached.
(3) In this state, it is left for 3 days under the condition of a temperature of 40 ° C.
(4) After leaving, measure the concentration of ammonia gas present in the ammonia water by the Kjeldahl method.
(5) The sample 1c is not charged, and the ammonia gas concentration after being left standing is measured by the Kjeldahl method (blank test).
(6) Compare the ammonia gas concentration in the blank test with the ammonia gas concentration when the sample 1c is charged, and if the ammonia gas concentration when the sample 1c is charged is lower than the ammonia gas concentration in the blank test, The sample 1c is a solid capturing organic resin capable of capturing ammonia gas.
[0022]
Specifically, as such a solid capture organic resin, for example, one or more types of copolymer selected from unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, and phosphoric acid Mention may be made of ethylene copolymers consisting of components and ethylene. Since such ethylene copolymer can capture ammonia gas by an acid-base reaction, it has an effect that there is no possibility of re-release.
[0023]
Examples of the unsaturated carboxylic acid that is a copolymer component include acrylic acid and methacrylic acid, and examples of the unsaturated carboxylic acid derivative include methyl acrylate, acrylate ester, butyl acrylate, Examples thereof include acrylic acid esters such as 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, methyl methacrylate, methacrylic acid ester, butyl methacrylate, and methacrylic acid esters such as 2-ethylhexyl methacrylate. Examples of the acid anhydride include maleic anhydride and itaconic anhydride. Examples of the sulfonic acid include sulfoxylic acid, dithionic acid, sulfurous acid, sulfuric acid, pyrosulfuric acid, peroxodisulfuric acid, and peroxosulfuric acid. , Thiosulfuric acid, benzenesulfonic acid Can be mentioned, as the phosphoric acid, for example, metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid, and tetraphosphoric acid. Among these, an ethylene copolymer composed of a copolymer component of unsaturated carboxylic acid (acrylic acid or methacrylic acid) and ethylene is preferable.
[0024]
Further, as another solid capture organic resin, for example, one or more copolymer components selected from unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, phosphoric acid, and propylene Mention may be made of the propylene copolymer consisting of Since such a propylene copolymer can capture ammonia gas by an acid-base reaction, there is an effect that there is no possibility of re-release. The unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, and phosphoric acid that are the copolymer components may be exactly the same as the copolymer components that constitute the ethylene copolymer. it can. Among these, a propylene copolymer composed of a copolymer component of unsaturated carboxylic acid (acrylic acid or methacrylic acid) and propylene is preferable.
[0025]
Furthermore, as another solid capturing organic resin, for example, a polymer obtained by graft polymerization of one or more components selected from an unsaturated carboxylic acid, an unsaturated carboxylic acid derivative, and an unsaturated carboxylic acid anhydride. Can do. These solid-trapping organic resins are particularly excellent in trapping ammonia gas, because they are not decomposed by heat during spinning. Examples of the polymer include polyolefin (propylene, low density polyethylene, medium density polyethylene, linear polyethylene, high density polyethylene, poly-4-methylpentene-1), polyamide (nylon 6, nylon 66, nylon 11, nylon). 12), polystyrene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer resin and the like. Further, the unsaturated carboxylic acid, the unsaturated carboxylic acid derivative, and the unsaturated carboxylic acid anhydride can be exactly the same as the copolymer component constituting the ethylene copolymer. Among these, what graft-polymerized unsaturated carboxylic acid (acrylic acid and methacrylic acid) to polyolefin olefins, such as polyethylene and a polypropylene, is preferable.
[0026]
Since the capture composite fiber of the present invention uses the solid capture organic resin as described above as a core component and is covered with a sheath component made of a fiber-forming resin, the solid capture organic resin that is the core component is less susceptible to external influences. Is. The “coating” in the present invention does not need to completely cover the core component of the sheath component, and is included in the concept of coating even if both ends of the fiber are not covered.
[0027]
As described above, the fiber-forming resin is a resin that can be fiberized by a conventionally known method, and is particularly preferably a resin that can be spun by a melt spinning method.
[0028]
In addition, since the capture composite fiber of the present invention basically captures ammonia gas that has permeated through the sheath component made of the fiber-forming resin, the fiber-forming resin that constitutes the sheath component is gas-permeable to nitrogen or oxygen. The coefficient is 1000ml / m ² -It is preferable to consist of resin more than d * MPa. This is because the fiber-forming resin having such a gas permeability coefficient can increase the trapping rate of ammonia gas and use the entire solid trapping organic resin without waste. In addition, although it is ammonia gas to be captured in the present invention, if the gas permeability coefficient of nitrogen or oxygen is equal to or higher than the above value, it has been found that the ammonia gas permeability is excellent and the scavenging property is also excellent. It is expressed not by the permeability coefficient of ammonia gas but by the permeability coefficient of nitrogen or oxygen. The higher the nitrogen or oxygen gas permeability coefficient of this fiber-forming resin, the better the effect, so the nitrogen or oxygen gas permeability coefficient is 5000 ml / m. ² More preferably a fiber-forming resin of d · MPa or more, 10000 ml / m ² -It is more preferable that it is fiber forming resin more than d * MPa. This gas permeability coefficient refers to a value obtained by measurement by a method defined in JIS K 7126.
[0029]
Examples of the fiber-forming resin having such a gas permeability coefficient include polyolefin resins and polystyrene. More specifically, as the former polyolefin-based resin, polyethylene, polypropylene, poly-4-methylpentene-1, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer , Polybutene, chlorinated polyethylene, and the like.
[0030]
The capture composite fiber of the present invention can be suitably used for capturing ammonia gas dissolved in an alkaline solution. In this case, when the fiber-forming resin is eroded by an alkaline solution, the solid capture organic resin captures ammonia gas. It is preferred that the fiber-forming resin be alkali resistant because performance tends to be lost. In addition, it can be judged as follows whether fiber forming resin is alkali resistance.
(1) The target resin is allowed to stand for 24 hours at a temperature of 20 ° C. and a relative humidity of 65%, and then weighed (Mb) with a precision balance.
(2) The target resin is boiled in a 30% aqueous potassium hydroxide solution for 1 hour. Thereafter, the target resin is washed with distilled water and dried.
(3) The dried resin of (2) above is allowed to stand for 24 hours at a temperature of 20 ° C. and a relative humidity of 65%, and then weighed (Ma) with a precision balance.
(4) If the mass (Ma) of the resin after boiling is 95% or more of the mass (Mb) of the resin before boiling, the resin can be judged to be alkali resistant.
[0031]
Examples of such alkali-resistant resins include polyolefin resins (especially polyethylene, polypropylene, poly-4-methylpentene-1), vinyl chloride, vinylidene chloride, polyvinyl alcohol, ABS (acrylonitrile-butadiene-styrene copolymer). And fluorine resins.
[0032]
When the capture composite fiber of the present invention is used as a separator constituting fiber for an alkaline battery, the capture is performed so that the fiber is oxidized during charging / discharging of the alkaline battery and the ammonia gas trapping action by the solid capture organic resin does not decrease. The fiber-forming resin of the composite fiber preferably has oxidation resistance. Whether or not the fiber-forming resin is oxidation-resistant depends on whether the mass of the target resin after being immersed in an alkaline potassium permanganate solution at a temperature of 80 ° C. for 60 hours is the mass before immersion. If it is 99% or more (preferably 99.5% or more), it can be judged that this resin is oxidation resistant. Examples of such oxidation-resistant fiber-forming resins include polyolefin resins (particularly polyethylene, polypropylene, poly-4-methylpentene-1), vinylidene chloride, ABS (acrylonitrile-butadiene-styrene copolymer), fluorine. Based resins and the like.
[0033]
As described above, polyolefin resins (especially polyethylene, polypropylene, poly-4-methylpentene-1) have high ammonia gas permeability, can increase the trapping rate of ammonia gas, and are resistant to alkali and oxidation. In addition to being excellent, (b) it can be melt-spun, (b) it is water-repellent, so it is difficult for the liquid to penetrate and reach the solid-trapping organic resin, (c) it is easily available, and (d) it is inexpensive. It is particularly suitable because it has various advantages such as.
[0034]
In the capture composite fiber of the present invention, the core component composed of the solid capture organic resin preferably occupies 10 mass% or more of the entire capture composite fiber, while the solid capture organic resin is 95 mass% or less of the entire capture composite fiber. It is preferable that it is 90 mass% or less. If the solid trapping organic resin is less than 10 mass%, the amount of trapped ammonia gas by the trapped composite fiber tends to be small, and the sheath component layer tends to be thick, and it tends to take time to trap the ammonia gas. It is. On the other hand, if the solid capture organic resin exceeds 95 mass%, the sheath component layer becomes thin and the liquid tends to reach the solid capture organic resin, which tends to reduce the ammonia gas capture ability of the solid capture organic resin. It is. Moreover, it is because there exists a tendency for a problem to occur in spinnability.
[0035]
The capture composite fiber of the present invention is in a state where it can capture ammonia gas in ammonia water even though the core component composed of a solid capture organic resin is coated with a sheath component composed of a fiber-forming resin. Therefore, the solid capture organic resin is not affected by the liquid, and can capture ammonia gas almost as the theoretical amount of the solid capture organic resin.
[0036]
This “state in which ammonia gas in the ammonia water can be captured” means that the ammonia gas concentration in the ammonia water is measured by the following operation using a measuring device 2 as shown in FIG. The case where it has the effect of reducing the ammonia gas concentration in water. Preferably, the degree of decrease in ammonia gas concentration is 0.05 mmol or more per gram of solid capture organic resin, and more preferably, the degree of decrease in ammonia gas concentration is 0.10 mmol or more per gram of solid capture organic resin. .
Record
(1) Ammonia water is prepared so as to have a concentration of 12 mmol / L, and 125 mL of this ammonia water is put into a 250 mL Erlenmeyer flask 2a (with glass stopper 2b).
(2) Put the sample 2c into the Erlenmeyer flask 2a and put the glass stopper 2b.
(3) Leave in this state for 3 days at a temperature of 40 ° C.
(4) After leaving, measure the concentration of ammonia gas present in the ammonia water by the Kjeldahl method.
(5) The sample 2c is not charged, and the ammonia gas concentration after standing is measured in the same manner by the Kjeldahl method (blank test).
(6) Compare the ammonia gas concentration in the blank test with the ammonia gas concentration when the sample 2c is charged, and if the ammonia gas concentration when the sample 2c is charged is lower than the ammonia gas concentration in the blank test, Sample 2c is in a “state capable of capturing ammonia gas in ammonia water”.
[0037]
The capture conjugate fiber of the present invention comprises the core component and the sheath component as described above, and the core component is preferably discontinuous in the fiber axis direction. When the core component is discontinuous in this way, even if the capture composite fiber is cut for use as a short fiber, the ammonia gas-dissolved solution (particularly, alkali solution) is difficult to reach the core component from the cut surface, and ammonia This is because ammonia gas can be efficiently captured as a result of being hardly affected by the gas-dissolved solution. Such a capture conjugate fiber can be produced, for example, by a mixed spinning method.
[0038]
The capture conjugate fiber of the present invention preferably has two or more core components in the fiber cross section. If two or more core components are provided in this way, even if an ammonia gas-dissolved solution (particularly an alkali solution) reaches one core component and the core component can no longer capture ammonia gas. This is because ammonia gas can be captured by the remaining core components.
[0039]
When two or more core components are provided in the fiber cross section, the cross-sectional areas of all the core components may be the same, or two or more core components having different cross-sectional areas may be provided. As in the latter case, when two or more types of core components having different cross-sectional areas are provided, the amount of the core component (the amount of the solid trapping organic resin) present in the capture composite fiber can be increased, and ammonia per fiber. This is preferable because the amount of trapped gas can be increased. In this case, the core components having different cross-sectional areas may be arranged in any way. However, when the maximum core component having the largest cross-sectional area is located at the center, the amount of the core component existing in the captured composite fiber (solid The amount of trapped organic resin) can be further increased, and the amount of trapped ammonia gas per fiber can be further increased, which is particularly suitable. Captured composite fibers having the same cross-sectional area of all the core components can be produced, for example, by a composite spinning method, and include captured composite fibers having two or more types of core components having different cross-sectional areas (cross-sectional area For example, composite spinning, mixed spinning, or by mixing a solid capture organic resin into the sheath component during composite spinning. can do.
[0040]
Further, the cross-sectional shape of the capture conjugate fiber of the present invention does not need to be circular, but is non-circular (for example, elliptical, elliptical, alphabetic (for example, T-shaped, Y-shaped, etc.), plus (+)-shaped. , Polygonal shape, etc.). Furthermore, you may have a continuous or discontinuous hollow part (part in which resin does not exist) in the length direction of a fiber.
[0041]
The fineness of the capture conjugate fiber of the present invention is not particularly limited, but about 0.1 to 100 tex is appropriate. Further, the fiber length of the capture composite fiber varies depending on the method of use. For example, about 25 to 160 mm is appropriate when used for dry nonwoven fabric applications, and 0.5 to 25 mm when used for wet nonwoven fabric applications. The degree is appropriate.
[0042]
The capture conjugate fiber of the present invention will be described based on FIG. 3 which is a schematic enlarged sectional view.
[0043]
FIG. 3A shows the capture composite fiber 3a in a state where the core component made of the solid capture organic resin 3a ″ is covered with the sheath component made of the fiber-forming resin 3a ′. In FIG. 3 (a), only one layer of fiber-forming resin is formed, but it is not necessary to be one layer and may be two or more layers. In FIG. 3A, the solid-capturing organic resin 3a ″ as the core component is at the center (located at the center) of the cross section, but the solid-trapping organic resin 3a ″ is a fiber-forming resin. It is sufficient if it is covered with 3a ′, and it may be offset from the center.
[0044]
FIG. 3B shows the capture composite fiber 3b in a state in which two or more core components made of the solid capture organic resin 3b ″ are present and covered with a sheath component made of the fiber-forming resin 3b ′. Thus, the core component does not need to be one and can be two or more.
[0045]
In FIG. 3 (c), there are two or more core components made of the solid-trapping organic resin 3c ″, and these core components are discontinuous in the fiber axis direction, and the sheath component is made of the fiber-forming resin 3c ′. It is the capture | acquisition composite fiber 3c of the state coat | covered with. Thus, the core component does not need to be continuous in the fiber axis direction.
[0046]
FIG. 3D shows the capture composite fiber 3d in a state in which the core component composed of two types of solid capture organic resins 3d ″ that differ in cross-sectional area is covered with the sheath component composed of the fiber-forming resin 3d ′. . Thus, the core components need not have the same cross-sectional area. Thus, when two or more types of core components having different cross-sectional areas are present, a large amount of the solid-capturing organic resin 3d ″ can be contained. Such a capturing composite fiber 3d includes a solid capturing organic resin A having a larger cross-sectional area and a solid capturing organic resin having a smaller cross-sectional area (the composition may be the same as or different from the solid capturing organic resin A). The mixed resin B mixed with the fiber-forming resin can be produced by complex spinning using a conventional method.
[0047]
Although not shown in the figure, unlike FIG. 3D, there is only one solid-trapping organic resin having a larger cross-sectional area (preferably located at the center of the cross-section), and the cross-sectional area is A large number of smaller solid-capturing organic resins may be present, and the captured composite fibers may be in a state where these solid-trapping organic resins are covered with a sheath component.
[0048]
Such a capture conjugate fiber of the present invention can be spun by utilizing a conventional compound spinning device or a mixed spinning device. For example, when spinning a capture composite fiber having a propylene copolymer (solid capture organic resin) composed of an unsaturated carboxylic acid and propylene as a core component and a high density polyethylene (fiber-forming resin) as a sheath component, the melt spinning temperature is 190. Spinning can be carried out by setting to ˜300 ° C., preferably 220 to 250 ° C.
[0049]
The undrawn yarn thus composite-spun can be drawn 2 to 10 times at a temperature below the melting point of the fiber-forming resin to produce a captured composite fiber having a fineness of about 0.1 to 100 dtex. In addition, when using this capture | acquisition composite fiber as a raw material of a dry-type nonwoven fabric or as a spun yarn, it is preferable to provide about 5-50 piece / inch of crimping mechanically or thermally.
[0050]
In order to spin the capture composite fiber 3d as shown in FIG. 3 (d), the solid capture organic resin A having a larger cross-sectional area and the solid capture organic resin (solid capture organic resin A and When the composite spinning of the mixed resin B in which the fiber-forming resin is mixed and the composition may be the same or different, the mixing amount of the solid-trapping organic resin in the mixed resin B is 5 to 45 mass% of the entire mixed resin B. Is preferred. If the amount is less than 5 mass%, the effect of capturing the ammonia gas by the solid trapping organic resin is low, and if it exceeds 45 mass%, it is difficult to cover with the fiber-forming resin, and the solid trapping organic resin is likely to come into contact with the liquid.
[0051]
As described above, since the capture composite fiber of the present invention has a large surface area, it can sufficiently capture ammonia gas, and the installation location is not limited. Moreover, since ammonia gas is trapped in the solid trapping organic resin and no adverse effects such as new ions remain, it can be used for trapping ammonia gas in various applications. In particular, the capture composite fiber of the present invention can capture ammonia gas in the liquid without being affected by the liquid even when immersed in the liquid. It can be used to trap ammonia gas dissolved in the solution. For example, it can be used to capture ammonia gas, which is a malodorous component dissolved in an industrial solution such as a chemical factory, a feed / fertilizer manufacturing factory, a food manufacturing factory, or an alkaline solution such as a livestock / hay animal treatment plant.
[0052]
The separator for alkaline batteries of the present invention (hereinafter sometimes simply referred to as “separator”) is composed of a fiber sheet containing the capture composite fiber as described above. Therefore, it has a large surface area and can sufficiently capture ammonia gas that causes self-discharge in alkaline batteries. Moreover, since it can arrange | position between a positive electrode and a negative electrode, ammonia gas can be capture | acquired efficiently. In other words, since the separator is located between the positive electrode and the negative electrode, which are ammonia gas moving paths, the ammonia gas is efficiently captured, the shuttle effect by the ammonia gas is suppressed, and the self-discharge is efficiently suppressed. Can do.
[0053]
The fiber sheet that is the separator of the present invention only needs to contain the capture conjugate fiber as described above, and the content of the capture conjugate fiber is not particularly limited, but occupies 10 mass% or more of the entire separator. Is preferred. This is because if it is less than 10 mass%, ammonia gas generated in the battery tends not to be sufficiently removed.
[0054]
Moreover, although the aspect of the fiber sheet which comprises the separator of this invention is not specifically limited, For example, a woven fabric, a knitted fabric, a nonwoven fabric etc. can be mentioned. Among these, it is preferable that the nonwoven fabric excellent in the retainability of electrolyte solution is included. In particular, wet nonwoven fabrics are suitable because they can take a dense structure and are excellent in electrolyte retention and insulation. In addition to the fiber sheet, a microporous film or the like may be combined.
[0055]
In addition, it is preferable that the separator of this invention is hydrophilized so that the retention property of electrolyte solution can be provided or improved. Examples of the hydrophilization treatment include sulfonation treatment, fluorine gas treatment, vinyl monomer graft polymerization treatment, discharge treatment, surfactant treatment, hydrophilic resin application treatment, and the like.
[0056]
The battery of the present invention is provided with a fiber sheet containing the capture composite fiber as described above as a separator. Conventionally, it is said that ammonia gas generated from the positive electrode is present in the alkaline electrolyte of the alkaline battery, and this ammonia gas causes self-discharge. However, the alkaline battery of the present invention has the above-described ammonia gas. Since it is possible to capture ammonia gas by providing a fiber sheet containing a capture composite fiber with excellent capture performance as a separator, self-discharge can be suppressed, and as a result, the alkaline battery has a long life. be able to.
[0057]
In addition, when the positive electrode active material with strong oxidizing power is used, the reaction of the surface of the separator being oxidized by the positive electrode active material under high temperature storage and the reduction of the positive electrode active material easily occurs. This oxidation-reduction reaction reduces the effective amount of the positive electrode active material that can contribute to power generation, and appears as a reduction in battery capacity due to self-discharge. The functional group constituting the solid capture organic resin (core component) constituting the capture conjugate fiber of the present invention is generally easily oxidized, but the fiber-forming resin that is the sheath component of the capture conjugate fiber of the present invention When a polyolefin resin having high oxidation resistance is used, the oxidation resistance is improved, and the self-discharge suppressing action is particularly excellent.
[0058]
The alkaline battery of the present invention can be exactly the same as the conventional alkaline battery except that the separator as described above is used.
[0059]
For example, a cylindrical nickel-hydrogen battery has a structure in which an electrode plate group obtained by winding a nickel positive electrode plate and a hydrogen storage alloy negative electrode plate in a spiral shape through a separator as described above is inserted into a metal case. As the nickel positive electrode plate, for example, a sponge-like porous porous material filled with an active material made of nickel hydroxide solid solution powder can be used. As the hydrogen storage alloy negative electrode plate, for example, a nickel plated perforated steel plate, For foamed nickel or nickel net, AB ₅ -Based (rare earth) alloy, AB / A ₂ B-based (Ti / Zr-based) alloy or AB ₂ Those filled with a (Laves phase) -based alloy can be used. As the electrolytic solution, for example, a potassium hydroxide / lithium hydroxide two-component system or a potassium hydroxide / sodium hydroxide / lithium hydroxide three-component system can be used. The case is sealed with an insulating gasket by a sealing plate provided with a safety valve. Furthermore, a positive electrode current collector and an insulating plate are provided, and if necessary, a negative electrode current collector is provided.
[0060]
The alkaline battery of the present invention does not need to be cylindrical, and may be rectangular, button type, or the like. In the case of a square type, it has a laminated structure in which a separator is disposed between a positive electrode plate and a negative electrode plate.
[0061]
Examples of the present invention will be described below, but the present invention is not limited to these examples.
[0062]
【Example】
(Example 1)
A known composite spinning device for producing core-sheath fibers is used, and polypropylene (oxygen permeability coefficient: 24500 ml / m) is used as the sheath component. ² ・ D · MPa), ethylene-methacrylic acid copolymer (amount of decrease in ammonia gas concentration: 0.52 mmol / g) as a core component was extruded from a nozzle at a spinning temperature of 230 ° C. (core-sheath mass ratio = 50/50) ), A wound yarn having a fineness of 6.6 dtex was obtained.
[0063]
Next, the wound yarn was stretched 5 times at a temperature of 90 ° C. and then cut to produce a captured composite short fiber (cross-sectional shape: circular) having a fineness of 1.5 dtex and a length of 5 mm. In addition, this capture | combination composite short fiber has one core component which consists of an ethylene-methacrylic acid copolymer which is continuous in a fiber axial direction and is located in the center in a cross section (FIG. 3 (a)).
[0064]
(Example 2)
A known composite spinning device for producing core-sheath fibers is used, and high-density polyethylene (oxygen permeability coefficient: 77420 ml / m) is used as a sheath component. ² Resin obtained by graft-polymerizing acrylic acid as a core component with a mixed resin obtained by mixing 20 mass% of an ethylene-methacrylic acid copolymer (amount of decrease in ammonia gas concentration: 0.52 mmol / g) with d · MPa) (Ammonia gas concentration decrease amount: 0.55 mmol / g) was extruded from a nozzle at a spinning temperature of 230 ° C. (core-sheath mass ratio = 50/50) to obtain a wound yarn having a fineness of 6.6 dtex.
[0065]
Next, the wound yarn was stretched 5 times at a temperature of 90 ° C. and then cut to produce a captured composite short fiber (cross-sectional shape: circular) having a fineness of 1.5 dtex and a length of 5 mm. This capture composite short fiber is continuous in the fiber axis direction and is located at the center in the cross section, and has one maximum core component made of a resin obtained by graft polymerization of acrylic acid on polypropylene, and is discontinuous in the fiber fiber axis direction. Yes, it had many core components made of an ethylene-methacrylic acid copolymer located around the maximum core component.
[0066]
Example 3
A known composite spinning device for producing core-sheath fibers is used, and high-density polyethylene (oxygen permeability coefficient: 77420 ml / m) is used as a sheath component. ² D · MPa) and a mixed resin obtained by mixing 20 mass% of an ethylene-methacrylic acid copolymer (ammonia gas concentration reduction amount: 0.52 mmol / g), and polypropylene (oxygen permeability coefficient: 24500 ml / m) as a core component. ² · A mixed resin obtained by mixing 20 mass% of ethylene-methacrylic acid copolymer (amount of decrease in ammonia gas concentration: 0.52 mmol / g) into a d · MPa) is extruded from a nozzle at a spinning temperature of 230 ° C. (core-sheath mass ratio) = 50/50) and a wound yarn having a fineness of 6.6 dtex was obtained.
[0067]
Next, the wound yarn was stretched 5 times at a temperature of 90 ° C. and then cut to produce a captured composite short fiber (cross-sectional shape: circular) having a fineness of 1.5 dtex and a length of 5 mm. In addition, this capture composite short fiber is composed of a large number of island components made of an ethylene-methacrylic acid copolymer discontinuous in the fiber axis direction at the core in the cross section, and an ethylene-methacrylic acid copolymer at the sheath. It has many island components that are discontinuous in the fiber fiber axis direction.
[0068]
(Comparative Example 1)
Using a known composite spinning device for producing core-sheath fibers, ethylene-methacrylic acid copolymer (ammonia gas concentration decrease: 0.52 mmol / g) is used as the sheath component, and polypropylene (oxygen transmission) as the core component. Coefficient: 24500 ml / m ² (D · MPa) was extruded from a nozzle at a spinning temperature of 230 ° C. (core-sheath mass ratio = 50/50) to obtain a wound yarn having a fineness of 6.6 dtex.
[0069]
Next, the wound yarn was stretched 5 times at a temperature of 90 ° C. and then cut to produce a composite short fiber (cross section: circular) having a fineness of 1.5 dtex and a length of 5 mm. This composite short fiber had one core component made of polypropylene, which was continuous in the fiber axis direction and located at the center in the cross section (FIG. 3A).
[0070]
(Comparative Example 2)
A known composite spinning device for producing core-sheath fibers is used, and high-density polyethylene (oxygen permeability coefficient: 77420 ml / m) is used as a sheath component. ² ・ D · MPa) as a core component, polypropylene (oxygen permeability coefficient: 24500 ml / m) ² (D · MPa) was extruded from a nozzle at a spinning temperature of 230 ° C. (core-sheath mass ratio = 50/50) to obtain a wound yarn having a fineness of 6.6 dtex.
[0071]
Next, the wound yarn was stretched 5 times at a temperature of 90 ° C. and then cut to produce a composite short fiber (cross section: circular) having a fineness of 1.5 dtex and a length of 5 mm. This composite short fiber had one core component made of polypropylene, which was continuous in the fiber axis direction and located at the center in the cross section (FIG. 3A).
[0072]
(Measurement of ammonia gas trapping amount)
Using the same measuring apparatus 2 as in FIG. 2, the amount of trapped ammonia gas was measured according to the following procedure.
(1) Ammonia chloride in which ammonium chloride is dissolved to a concentration of 12 mmol / L is prepared in an 8 mol / L potassium hydroxide aqueous solution, and 125 mL of this solution is added to a 250 mL Erlenmeyer flask 2a (with glass stopper 2b). I put it in.
(2) 0.4 g of each captured composite short fiber or composite short fiber 2c was added to the Erlenmeyer flask 2a, and then a glass stopper 2b was used.
(3) This was left for 3 days under the condition of a temperature of 40 ° C.
(4) After standing, the ammonia gas concentration present in the ammonia water was measured by the Kjeldahl method.
(5) The trapped composite short fiber or composite short fiber 2c was not charged, and the ammonia gas concentration after standing was measured in the same manner by the Kjeldahl method (blank test).
(6) The difference (D) between the ammonia gas concentration in the blank test and the ammonia gas concentration when the captured composite short fiber or composite short fiber 2c was introduced was calculated.
(7) From the following formula, the ammonia gas trapping amount (mmol / g) per 1 g of the solid trapping organic resin was calculated.
Ammonia gas trapping amount (mmol / g) = {D ÷ (1000 ÷ 125)} ÷ 0.4 ÷ M = D / 3.2M
[0073]
Here, D means the difference (mmol / L) between the ammonia gas concentration in the blank test and the ammonia gas concentration when the trapped composite short fiber or composite short fiber 2c is introduced, and M is the amount of solid trapped organic resin (g ). The result was as shown in FIG. In Comparative Example 2, since there is no solid capture organic resin, it cannot be calculated from the above formula, but the amount of ammonia gas trapped by the entire composite short fiber was 0 mmol, so ammonia gas per gram of the solid capture organic resin The captured amount is expressed as 0. As is apparent from the results of FIG. 4, the composite fiber of the present invention was able to remove ammonia gas in the alkaline solution. On the other hand, the composite short fiber of the comparative example could not remove ammonia gas.
[0074]
(Measurement of capacity retention)
A fiber web is formed by a wet method using 100% of the composite short fibers produced according to the examples or the composite short fibers produced according to the comparative example, and then each fiber web is configured with respect to the fiber web. It is melt bonded by passing hot air heated to the melting point of the sheath component of the fiber, and the basis weight is 60 g / m. ² And the nonwoven fabric 5f whose thickness is 0.15 mm was produced.
[0075]
Further, a discharge treatment apparatus as shown in FIG. 5, that is, a pair of flat stainless steel carrying a polytetrafluoroethylene film (substantially non-porous, thickness: 0.2 mm) as the dielectrics 5d and 5e. A discharge treatment apparatus 5 was prepared in which electrodes 5b and 5c (size: 150 mm × 210 mm) were arranged so that the dielectrics 5d and 5e face each other.
[0076]
Next, a bipolar sine wave in air at atmospheric pressure with the non-woven fabric 5f held between the dielectrics 5d and 5e of the discharge treatment apparatus 5 by utilizing the weight of one flat stainless steel electrode 5b. Voltage (high-frequency power supply AGI-020 (manufactured by Kasuga Electric) 5a, output: 800 W, output per unit area: 1.6 W / cm ² , Energy per unit area: 12.7 J / cm ² , Frequency: 20 kHz) was applied between both electrodes for 10 seconds to generate a discharge in the internal voids of the nonwoven fabric 5f, and to make hydrophilic, to produce a hydrophilic nonwoven fabric, which was used as a separator.
[0077]
In addition, a paste-type nickel positive electrode (33 mm, 182 mm length) using a foamed nickel base and a paste-type hydrogen storage alloy negative electrode (mesh metal alloy, 33 mm, 247 mm length) were prepared as electrode current collectors.
[0078]
Next, each separator cut into a width of 35 mm and a length of 410 mm was sandwiched between the positive electrode and the negative electrode and wound in a spiral shape to create an SC-type electrode group.
[0079]
Next, after this electrode group was housed in an outer can, 5N-potassium hydroxide and 1N-lithium hydroxide were poured into the outer can as an electrolytic solution and sealed to prepare a cylindrical nickel-hydrogen battery.
[0080]
Next, the cylindrical nickel-hydrogen battery was charged at 150% with respect to the capacity at 0.1 C, then discharged at 0.1 C, and the initial capacity (A) at a final voltage of 1.0 V was measured. Next, after charging 150% of the capacity at 0.1 C, it was left in a constant temperature room at 65 ° C. for 5 days. Thereafter, the battery was discharged again at 0.1 C, and the capacity (B) at a final voltage of 1.0 V was measured. From these results, the capacity retention was calculated by the following equation.
(Capacity retention,%) = (B / A) × 100
[0081]
These results were as shown in FIG. From the results of FIG. 4, it was found that the separator using the capture composite fiber of the present invention is excellent in self-discharge suppressing action.
[0082]
【The invention's effect】
The ammonia gas capturing composite fiber of the present invention can sufficiently capture ammonia gas. Further, since ammonia gas is trapped in the ammonia gas trapping composite fiber, there is no adverse effect such as new ions remaining.
[0083]
The separator for alkaline batteries of the present invention can sufficiently capture ammonia gas that is the cause of self-discharge in alkaline batteries. Moreover, since it can arrange | position between a positive electrode and a negative electrode, ammonia gas can be capture | acquired efficiently.
[0084]
The alkaline battery of the present invention is an alkaline battery that is difficult to self-discharge. Moreover, since the neutralization reaction does not occur with the alkaline solution that is the electrolytic solution, the alkaline battery can exhibit a desired capacity.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a measuring apparatus for judging whether a solid-trapping organic resin is used.
FIG. 2 is a schematic cross-sectional view of a measuring apparatus that determines whether ammonia gas in ammonia water can be captured.
FIG. 3 (a) is an example of a schematic cross-sectional view of the ammonia gas-trapping composite fiber of the present invention.
(B) Other example of schematic cross-sectional view of ammonia gas capturing composite fiber of the present invention
(C) Other exemplary schematic cross-sectional views of the ammonia gas-trapping composite fiber of the present invention
(D) Other example of schematic sectional view of ammonia gas capturing composite fiber of the present invention
FIG. 4 is a table showing ammonia gas trapping amounts and capacity retention rates of ammonia gas trapping composite fibers in Examples.
FIG. 5 is a schematic cross-sectional view of a discharge treatment apparatus for hydrophilizing a battery separator.
[Explanation of symbols]
1 Schematic cross-sectional view of a measuring device that determines whether it is a solid-trapping organic resin
1a Erlenmeyer flask
1b Glass stopper
1c Sample
2 Measuring device to judge whether ammonia gas in ammonia water can be captured
2a Erlenmeyer flask
2b Glass stopper
2c sample
3a, 3b, 3c, 3d Ammonia gas capture composite fiber
3a ′, 3b ′, 3c ′, 3d ′ Fiber-forming resin (sheath component)
3a ″, 3b ″, 3c ″, 3d ″ Solid capture organic resin (core component)
5 Discharge treatment equipment
5a High frequency power supply
5b, 5c Flat stainless steel electrode
5d, 5e dielectric
5f Nonwoven fabric

Claims (12)

A core component composed of a solid-capturing organic resin capable of capturing ammonia gas after being melted and solidified is covered with a sheath component composed of a fiber-forming resin, and is capable of capturing ammonia gas in ammonia water. Gas capture composite fiber. The solid-trapping organic resin comprises an ethylene copolymer composed of one or more copolymer components selected from unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, and phosphoric acid and ethylene. The ammonia gas-trapping composite fiber according to claim 1, wherein: The solid-trapping organic resin comprises a propylene copolymer comprising at least one copolymer component selected from unsaturated carboxylic acid, unsaturated carboxylic acid derivative, unsaturated carboxylic acid anhydride, sulfonic acid, and phosphoric acid and propylene. The ammonia gas-trapping composite fiber according to claim 1, wherein: The solid-capturing organic resin comprises a polymer obtained by graft polymerization of at least one component selected from an unsaturated carboxylic acid, an unsaturated carboxylic acid derivative, and an unsaturated carboxylic acid anhydride. Item 2. The ammonia gas-trapping composite fiber according to Item 1. The ammonia gas-trapping composite fiber according to any one of claims 1 to 4, wherein the fiber-forming resin comprises a polyolefin-based resin. The ammonia gas-trapping composite fiber according to any one of claims 1 to 5, wherein the core component is discontinuous in the fiber axis direction. The ammonia gas-trapping composite fiber according to any one of claims 1 to 6, comprising two or more core components in a fiber cross section. The ammonia gas-trapping composite fiber according to any one of claims 1 to 7, wherein the fiber cross-section includes two or more types of core components that differ in cross-sectional area. 9. The ammonia gas-trapping composite fiber according to claim 8, wherein the largest core component having the largest cross-sectional area is located at the center in the cross section of the fiber. The ammonia gas-trapping composite fiber according to any one of claims 1 to 9, which is used for trapping ammonia gas dissolved in an alkaline solution. An alkaline battery separator comprising a fiber sheet containing the ammonia gas-trapping composite fiber according to any one of claims 1 to 9. An alkaline battery comprising a fiber sheet containing the ammonia gas-trapping composite fiber according to any one of claims 1 to 9 as a separator for an alkaline battery.

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