JP4475509B2 - Allophane-based rayon and method for producing the same - Google Patents

Description

  The present invention relates to a rayon in which one or both of allophane and coal ash are dispersed in a fiber, and a method for producing the same.

  In recent years, it has been widely known that substances called environmental hormones and similar substances have an adverse effect on the reproduction of organisms. Therefore, in order to prevent environmental hormones from being released into the ecosystem, for example, environmental hormones contained in wastewater generated at industrial waste treatment facilities are decomposed by laser irradiation or high-pressure treatment. It is also widely recognized that workers in industrial waste treatment facilities need to take appropriate measures to prevent ingestion of environmental hormones.

As one of the environmental hormone analogs, diethyl phthalate (sometimes abbreviated as DEP in this specification) is known. This is the material used when processing vinyl chloride. Recent research has shown that allophane is useful as a substance that adsorbs and decomposes DEP. Allophane is a clay material mainly composed of silicon dioxide, alumina, and ferric trioxide. Allophane is already known as having a deodorizing antibacterial action. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-47493) discloses an allophenic clay mineral coating layer on the surface of a plastic sheet material. An aggregating material is disclosed. Patent Document 2 (Japanese Patent No. 3215318) discloses that allophane can be used as an additional adsorbent in a fiber containing a photocatalyst and a specific adsorbent.
JP 2001-47493 A Japanese Patent No. 3215318

  The inventors have focused on the ability of allophane to decompose DEP, and if a fiber containing high concentration of allophane is produced, a filter suitable for treating waste water containing DEP, and an industrial waste treatment facility We thought that we could get work clothes for workers. Therefore, an object of the present invention is to provide a fiber using the DEP resolution of allophane.

  The present inventors have studied to obtain a fiber having a configuration that can effectively use not only allophane present on the fiber surface but also allophane present in the fiber. As a result, if allophane is dispersed in rayon, DEP contained in the moisture infiltrated into the fiber can be decomposed by utilizing the water absorption swellability of rayon, and synthetic fibers containing allophane (mostly water absorption) It was considered that more waste water can be treated compared with the other, and that more allophane can be decomposed.

  Furthermore, the present inventors pay attention to the fact that the structures of allophane and coal ash are similar, and if a fiber having DEP resolution can be produced using coal ash together with or instead of allophane, thermal power generation We thought that the coal ash generated in the place can be used effectively. Coal ash generated by burning coal in thermal power plants and the like is partially reused as road material, building material, and cement raw material, but most of it is discarded by landfill. Therefore, it is highly desired in the industry to reuse this. Then, when it examined also about whether coal ash has DEP resolution | decomposability, it confirmed that coal ash had DEP resolution | decomposability like allophane.

  That is, the present invention provides an allophane-based material-containing rayon containing 1 to 20 parts by mass of allophane and / or coal ash with respect to 100 parts by mass of cellulose. In this rayon, allophane and / or coal ash is dispersed throughout the fiber, so that not only the fiber surface but also DEP that has entered the fiber can be decomposed. The rayon is particularly suitable for decomposing DEP in waste water because rayon has a particularly high water absorption property and has the property of taking water inside and swelling. The inventors have also found that rayon itself has some ability to degrade DEP. Therefore, the present invention can be provided as a DEP degradable fiber in which the DEP decomposing ability of rayon and allophane and / or coal ash is synergistically exhibited.

  The allophane-based material-containing rayon of the present invention may contain allophane alone, coal ash alone, or both. The term “and / or” is used in that sense. Allophane is generally a natural clay mineral, but artificially produced allophane may be used. Coal ash is generally discharged by burning coal at a thermal power plant or the like, and is called fly ash, clinker ash, or the like. Further, in the present specification, since coal ash has a structure similar to allophane, allophane and coal ash are collectively referred to (that is, instead of the term “allophane and / or coal ash”). The term "systemic substance" is used.

  In the allophane-based material-containing rayon of the present invention, it is preferable that 90% or more of allophane and / or coal ash particles contained in the rayon have a particle size of 3 μm or less. By using allophane containing at least 90% of small allophane and / or coal ash particles having a particle size of a specific value or less, a maximum of 20 parts by mass of allophane can be dispersed better in the fiber with respect to 100 parts by mass of cellulose. It becomes possible.

The present invention also provides a method for producing the allophane-based material-containing rayon.
Preparing an allophane-based material dispersion in which allophane and / or coal ash, and nonionic surfactant and carboxymethylcellulose are dispersed in water;
Provided is a method for producing an allophane-based material-containing rayon, comprising adding and mixing an allophane-based material dispersion into viscose, and spinning the viscose to which the allophane-based material dispersion is added.

  Since allophane is a clay mineral and easily aggregates in water, it is generally difficult to disperse it in fibers. Coal ash is also generally difficult to disperse in the fiber. Further, since silicon dioxide in allophane and coal ash is soluble in alkali, it was expected to be difficult to disperse it in rayon. In the present invention, as a method of dispersing allophane and / or coal ash, a method of mixing an allophane-based material aqueous dispersion in which allophane and / or coal ash is dispersed into viscose, and a specific surfactant is used. By preparing an allophane-based material dispersion using, allophane-based material can be uniformly dispersed in viscose. More specifically, the production method of the present invention is characterized in that an allophane-based substance is dispersed using a nonionic surfactant as a dispersant. Furthermore, in the production method of the present invention, carboxymethylcellulose sodium (sometimes abbreviated as CMC in this specification) is used as a viscosity modifier and an anti-settling agent together with an allophane-based material and a nonionic dispersant. It is preferable to prepare an allophane-based material dispersion by dispersing in water. It has been found that the use of a nonionic surfactant is advantageous in that the allophane-based substance can be dispersed in the viscose at a higher content as compared with the case of using a cationic surfactant. It was also found that the allophane-based substance can be dispersed more stably by adding CMC. CMC plays a role in protecting allophane-based materials from viscose when allophane-based material dispersion is added to viscose, preventing allophane-based materials from coming into contact with alkali, and suppressing elution of silicon dioxide Presumed to be. In addition, CMC reacts with an acid at the time of spinning to become carboxymethylcellulose, which has the same structure as the skeleton of cellulose that is a fiber component. Also, the fiber performance is not actually greatly affected by the presence of CMC. For these reasons, CMC is preferably used as a dispersion aid for allophane-based materials. However, it should be noted that the reason described here is only an estimate and does not affect the scope of the present invention.

  In the present invention, the allophane-based material dispersion is preferably treated with a wet pulverizer. Thereby, allophane and / or coal ash particles are crushed and present in the dispersion in a more refined form. Fine allophane and / or coal ash particles are well dispersed in the viscose. The allophane and / or coal ash particles are preferably ground so that at least 90% of the particles have a particle size of 2 μm or less.

  The allophane-containing rayon of the present invention has a structure in which allophane and / or coal ash is dispersed in the fiber, and has the property of significantly decomposing DEP in combination with the water absorption and DEP resolution of rayon. Present. Therefore, the allophane-based substance-containing rayon of the present invention is suitable for constituting a filter, clothes, etc. used in an environment having a high DEP concentration.

  Further, the production method of the present invention requires only adding the allophane-based material dispersion prepared by a specific method to viscose, and does not require any special operation in spinning viscose. Therefore, according to the production method of the present invention, a rayon containing allophane and / or coal ash can be obtained by an ordinary method using an ordinary rayon production apparatus.

  It is preferable that 90% or more of the allophane-based material, ie, allophane and / or coal ash, contained in the allophane-based material-containing rayon of the present invention has a particle size of 3 μm or less. When the allophane-based material is produced using a dispersion of allophane-based material, the dispersion, or viscose added thereto or cellulose fiber after spinning is observed with an optical microscope (160 times magnification). The diameter of about 1000 allophane-based material particles (excluding those that are clearly aggregated) included in one field of view is measured by a method of visually measuring. When the allophane-based substance particles are irregular, the longest line segment connecting any two points on the particle outline is defined as the particle diameter of the particle. In the present invention, the particle diameter measured in this way is preferably 3 μm or less for particles having a particle size of 90% or more (90% or more). Such fine allophane can be obtained by pulverizing natural allophane or coal ash discharged from a thermal power plant using a suitable fine pulverizer (jet mill).

  In the rayon of the present invention, 90% or more of the allophane-based material particles preferably have a particle size of 2 μm or less, and specifically 90% or more of the allophane-based material particles have a particle size of 1 to 2 μm. Such an allophane-based material having a small particle size can be obtained, for example, by further processing an aqueous solution in which 90% or more of the allophane-based material having a particle size of 3 μm or less is dispersed with a wet pulverizer.

  Content of an allophane type substance is 1-20 mass parts with respect to 100 mass parts of cellulose of a fiber, Preferably it is 5-15 mass parts. When the content of the allophane-based substance is small, the DEP resolution of the fiber becomes insufficient. The higher the allophane-based material content, the higher the fiber DEP resolution. However, it is difficult to disperse allophane-based substances in large quantities in rayon. Therefore, in order to achieve practical fiber productivity, the upper limit of the allophane-based material content is preferably about 20 parts by mass with respect to 100 parts by mass of cellulose. Moreover, when coal ash is contained in rayon, it is preferable from the viewpoint of DEP resolution that the coal ash and allophane are used in combination (both are used in combination).

  The allophane-based material-containing rayon of the present invention can be produced by an ordinary viscose spinning method as described later. Therefore, the fineness can be arbitrarily selected according to the application and the like, and is selected from the range of 1 to 17 dtex, for example. It may be provided in any form of staples and filaments.

  The allophane-based material-containing rayon of the present invention may be any of ordinary rayon, strong rayon, and polynosic. In addition, the allophane-based material-containing rayon of the present invention is used for spinning into a spun yarn, or for producing a nonwoven fabric or paper. The spun yarn is further used to produce woven and knitted fabrics. These non-woven fabrics, paper, woven fabrics and knitted fabrics are provided as products used in environments with high DEP concentrations, such as work clothes and masks for workers engaged in industrial waste treatment, and filters for treating waste water. It is particularly preferred that Further, the fiber product containing the rayon of the present invention can be widely used in the same application as the fiber product containing a normal rayon. For example, the fiber product containing the rayon of the present invention can be provided as a member of interior products such as curtains and carpets, in which case the environmental hormones that enter from the outside or are released from building materials are decomposed to improve the indoor environment. Can be maintained. Or the nonwoven fabric containing the rayon of this invention can be used as a disposable wiper and a simple filter, In that case, it becomes possible to decompose | disassemble the environmental hormone contained in the substance hold | maintained in the nonwoven fabric.

  Or the allophane type substance containing rayon of this invention can be made to function as a kind of DEP decomposition | disassembly material by throwing into wastewater containing DEP as it is. Since rayon is biodegradable, it can be decomposed naturally by putting it in wastewater and leaving it to stand, so there is no need to recover the rayon-containing rayon of the present invention. Can be used as wastewater treatment material. The rayon used as such a wastewater treatment material preferably has a fineness of 1.7 to 10 dtex.

  Next, a method for producing the allophane-based material-containing rayon of the present invention will be described. The allophane-based material-containing rayon of the present invention is produced by a method in which an allophane-based material dispersion is added to viscose and the viscose is spun. The allophane-based material dispersion is prepared by dispersing at least one material selected from allophane and coal ash, which is an allophane-based material, in water together with a nonionic surfactant and preferably CMC. The allophane-based material dispersion preferably contains 5 to 20% by mass of the allophane-based material and 0.1 to 2% by mass of the nonionic surfactant, and further 0.1 to 1% by mass of CMC. It is more preferable to contain.

  The allophane-based material is preferably dispersed in water after pulverizing natural allophane or coal ash from a thermal power plant so that the particle size of 90% or more is 3 μm or less. This is to improve the dispersibility in viscose. As the nonionic surfactant, for example, M-138 (trade name) manufactured by Takemoto Yushi Co., Ltd. and BEROL VISCO 32 (trade name) manufactured by Akzo Nobel Co., Ltd. can be used.

  The allophane-based material dispersion is preferably processed by a wet pulverizer. Thereby, the allophane-based substance can be dispersed into finer particles (specifically, the proportion of particles having a particle diameter of about 1 to 2 μm is 90% or more). As the wet pulverizer, a commercially available one can be arbitrarily used. For example, DYNO-MILL (trade name): manufactured by Shinmaru Enterprises Co., Ltd. can be preferably used. The treatment by the wet pulverizer may be preferably repeated a plurality of times (for example, 2 to 5 times). In that case, the particle size of the allophane-based material can be further reduced. The dispersion after the treatment by the wet pulverizer may be filtered as necessary in order to remove coarse particles (≧ 10 μm) in the liquid.

  The allophane-based material dispersion thus prepared is added to viscose to obtain viscose containing the allophane-based material. The addition amount of the allophane-based material dispersion is such that the cellulose concentration in the viscose and the concentration of the allophane-based material in the allophane-based material dispersion are such that the final concentration of the allophane-based material is dispersed in the fiber. Is selected.

  The viscose added with the allophane-based material dispersion is mixed so that the allophane-based material is uniformly dispersed. This viscose is fiberized by spinning in a normal method using a normal spinning bath, and the allophane-based material-containing rayon of the present invention can be obtained by scouring this fiber by a normal method. . In the scouring step, bleaching (ie, bleaching) may or may not be performed. When bleaching is performed, the resolution of DEP tends to be slightly reduced.

  The decomposition of DEP by the allophane-based material-containing rayon of the present invention is considered to proceed as follows. That is, in the following formula, diethyl phthalate (DEP) is converted into an ethyl phthalate anion (EP) anion by hydrolysis, and this EP anion is decomposed by decarboxylation to produce ethyl benzoate (EB). , And the EP anion is further hydrolyzed to produce a phthalic acid (PA) dianion, and the PA anion is further degraded by decarboxylation to produce a benzoic acid (BA) anion. Although not shown in the formula, it is believed that the EB ethyl and EB anions further decompose to produce benzene.

  Hereinafter, the content of the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

Example 1
Natural allophane was pulverized with a jet mill manufactured by Hosokawa Micron Corporation to obtain allophane powder. In this allophane powder, 90% or more of the particles had a particle diameter of about 3 μm. The allophane powder, nonionic surfactant (BEROL VISCO 32 (trade name) manufactured by Akzo Nobel Co., Ltd.) and CMC in the ion-exchanged water account for 10% by mass and 0.5% by mass, respectively. And 0.2% by mass to obtain an allophane dispersion. Next, this dispersion was treated with a wet pulverizer (Dyno Mill, manufactured by Shinmaru Enterprises Co., Ltd.). The treatment was repeated 4 times with a flow rate of 10 liters / hour. Further, the dispersion was filtered through a bag filter to remove coarse particles.

  A viscose having a cellulose content of 8.5% by mass, sodium hydroxide of 5.7% by mass, carbon disulfide of 32% by mass (relative to the mass of cellulose) and a falling ball viscosity of 56 seconds and an ammonium chloride value of 17 cc was prepared. . The allophane dispersion was added to this viscose in such an amount that the amount of allophane was 10 parts by mass with respect to 100 parts by mass of cellulose and mixed to disperse allophane.

  The obtained mixed viscose was spun by a two-bath tension spinning method at a spinning speed of 50 m / min and a draw ratio of 50% to obtain a fiber having a fineness of about 5.6 dtex. The composition of the first bath (spinning bath) was 115 g / l sulfuric acid, 15 g / l zinc sulfate, 350 g / l sodium sulfate, and the temperature was 50 ° C. The spinning nozzle had 4000 holes with a hole diameter of 0.09 mm. During spinning, there was no inconvenience such as single yarn breakage, and the spinnability of the mixed viscose was good.

  The viscose rayon thus obtained was subjected to a scouring process. The scouring process was carried out in the order of hot water treatment, water flow treatment, bleaching, pickling, and oiling (ie oiling) in the usual manner. Bleaching was performed using an aqueous sodium hypochlorite solution (0.03% by mass). After applying the oil agent, excess oil agent was dropped from the fibers with a compression roller, followed by drying (60 ° C., 7 hours) to obtain an allophane-based material-containing rayon.

(Example 2)
In the scouring step, unbleached (unbleached) allophane-based rayon was obtained in the same manner as in Example 1 except that only hot water treatment and desulfurization were performed without performing bleaching.

(Example 3)
After obtaining the allophane dispersion in the same manner as in Example 1, the allophane was added in an amount such that the amount of allophane was 2.6 parts by mass with respect to 100 parts by mass of the cellulose, and mixed to add allophane to the viscose. Dispersed in. Next, this viscose was carried out as described above, except that a stretch ratio of 50% was used using a nozzle having 4000 holes with a pore diameter of 0.07 mm so that a fiber having a fineness of about 1.7 dtex was obtained. Spinning was carried out under the same spinning conditions as those employed in Example 1, and subjected to a scouring step to obtain an allophane-based material-containing rayon.

(Comparative Example 1)
A rayon was obtained in the same manner as in Example 2 except that no allophane dispersion was added.

(Comparative Example 2)
Allophane powder and a cationic surfactant mainly composed of polyethyleneimine were mixed in ion-exchanged water so that the total proportions were 10% by mass and 0.4% by mass, respectively. Next, this mixed liquid was treated with a wet pulverizer (Dynomill, manufactured by Shinmaru Enterprises Co., Ltd.) to prepare an allophane dispersion. The treatment by the wet pulverizer was carried out under the same conditions as those employed in Example 1, and the coarse particles were removed by filtration through a bag filter after the treatment. When this allophane dispersion was added to viscose in the same manner as in Example 1 and this viscose was spun, single yarn breakage occurred shortly after spinning, and spinning could not be performed. This Comparative Example 2 shows that the cationic surfactant is not suitable for dispersing allophane.

(Fiber performance)
The tensile strength, elongation and ash content of the rayon obtained in Examples 1 to 3 and Comparative Example 1 were measured. Tensile strength and elongation were measured according to JIS L 1015, and measured in a dry and wet state. Ash content was also measured according to JIS L 1015. The results are shown in Table 1.

(Evaluation of DEP resolution)
The DEP adsorption resolution of the fibers of Examples 1 and 2 and Comparative Example 1 was evaluated as follows. 0.5 g of the fiber to be evaluated was immersed in 8 ml of 0.05 mM DEP aqueous solution, held in a constant temperature bath at 35 ° C., and allowed to pass for 24 hours. After a lapse of 24 hours, a part of the solution was collected with a syringe, and its UV spectrum (wavelength 200 to 300 nm) was measured. Thereafter, another 24 hours were passed, and a part of the solution was collected and the UV spectrum was measured three times.

  Separately, a 0.05 mM aqueous solution of DEP and the degradation products of DEP, phthalate (PA) dianion, ethyl phthalate (EP) anion, benzoic acid (BA) anion and ethyl benzoate (EB) For each, the UV spectrum of an aqueous solution containing each compound or ion at a concentration of 0.05 mM was measured. These compounds are expected to be produced when DEP decomposes as described above.

  From the measurement results of these UV spectra, the change with time of the ratio of DEP and decomposition products (PA dianion, BA anion and EB) in the solution was determined for the solution in which each fiber was immersed. Specifically, the spectrum of the DEP solution after a certain period of time has been immersed in each fiber and the spectrum of the decomposition product alone that has been measured in advance as described above are combined and fitted, The proportion of each component in the solution was estimated. The results are shown in Table 2.

  As shown in Table 2, even when the rayon of Comparative Example 1 (rayon not containing allophane) was immersed in an aqueous DEP solution, a decrease in DEP and generation of PA dianions were observed, and the rayon itself had DEP resolution. confirmed. When the allophane-based material-containing rayon of the present invention was immersed in an aqueous DEP solution, the formation of EB, PA dianion and BA anion was confirmed. The formation of EB (ethyl benzoate) indicates that the EP (ethyl phthalate) anion has been further decomposed, and the formation of benzoic acid (BA) anion indicates that the phthalate (PA) dianion has been further decomposed. Therefore, it is shown that the allophane-based material-containing rayon of the present invention exhibits high DEP resolution. Further, it was confirmed that the allophane-based material-containing rayon of the present invention has DEP resolution both when bleached (Example 1) and when unbleached (Example 2). In particular, the ratio of DEP after 24 hours in the solution soaked with the fiber of Example 1 is smaller than that of the solution soaked with the fiber of Example 2, and the unbleached fiber is more degraded than the bleached fiber. It shows that it can progress quickly.

  Similarly, the fiber of Example 3 was immersed in 8 ml of 0.05 mM DEP aqueous solution, and the UV spectrum of the solution was similarly measured every 24 hours. As a result, a spectrum having a shape different from the UV spectrum of 0.05 mM DEP aqueous solution was obtained with the passage of time, and it was confirmed that the ratio of DEP decreased.

Since the allophane-based material-containing rayon of the present invention has DEP resolution, it can be used as a wastewater treatment material as it is, and the allophane-based material-containing rayon of the present invention can be used to produce various textile products in the same manner as ordinary rayon. Since it can, it is suitable for manufacturing filters or clothing with DEP resolution.

Claims (7)

An allophane for decomposing diethyl phthalate , which is a rayon obtained by spinning viscose mixed with allophane and / or coal ash and containing 1 to 20 parts by mass of allophane and / or coal ash with respect to 100 parts by mass of cellulose Rayon containing chemical substances. Wastewater treatment containing diethyl phthalate , which is a rayon obtained by spinning viscose to which allophane and / or coal ash is added and containing 1 to 20 parts by mass of allophane and / or coal ash with respect to 100 parts by mass of cellulose allophane-based material containing rayon of use. The allophane-based material-containing rayon according to claim 1 or 2 , wherein 90% or more of the allophane and / or coal ash particles contained in the rayon has a particle size of 2 µm or less. The allophane-based material-containing rayon according to claim 1 or 2, wherein the rayon contains a nonionic surfactant and sodium carboxymethylcellulose. Preparing an allophane-based material dispersion in which allophane and / or coal ash, and nonionic surfactant and sodium carboxymethylcellulose (CMC) are dispersed in water;
A method for producing an allophane-based material-containing rayon, comprising adding and mixing an allophane-based material dispersion with viscose, and spinning the viscose with the allophane-based material dispersion added. The allophane-based material dispersion liquid contains 5 to 20% by mass of allophane and / or coal ash, 0.1 to 2% by mass of nonionic surfactant, and 0.1 to 1% by mass of CMC. 6. A method for producing an allophane-based material-containing rayon according to 5. The production method according to claim 5 , wherein the allophane-based material dispersion is treated with a wet pulverizer such that 90% or more of the allophane particles contained in the dispersion have a particle diameter of 2 µm or less.