JP2015019652A - Artificial soil particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide artificial soil particles capable of effectively suppressing generation of algae, such as algal bloom.SOLUTION: An artificial soil particles 51 is constructed by assembling a plurality of fillers 1 comprising narrow holes 2. A communicating hole 3 is formed between the fillers 1. Titanium oxide 6 having a function as an algaproof/antifungal agent is carried on at least a region from an opening part 3a of the communicating hole 3 to particle surface 51a. The narrow holes 2 have a size of sub nm order to sub μm order. The communicating hole 3 has a size of sub nm order to sub μm order. The titanium oxide 6 is a titanium oxide fine particle 6a having a smaller particle diameter than the size of the communicating hole 3.

Description

  The present invention relates to artificial soil particles that can be used as artificial soil that is substituted for natural soil.

  In recent years, plant factories that grow plants such as vegetables and flower buds in an environment in which growth conditions are controlled are increasing. Conventional plant factories have been centered on hydroponics of leafy vegetables such as lettuce, but recently, various plants such as flower buds and root vegetables have been cultivated using artificial soil. . Artificial soil used in plant factories and the like is required not only to have excellent basic performance as soil, but also to have a clean feeling and be easy to handle. For example, products have been developed in which artificial soil is placed in transparent or translucent pots and indoor plants are cultivated. Such products with high interior properties are particularly required to have a beautiful appearance and a clean feeling. The However, since artificial soil is exposed to a humid environment for a long period of time, bacteria and moss breed on the artificial soil during plant cultivation, resulting in root rot of the cultivated plant, resulting in the beauty of the houseplant. And sanitary hygiene.

  Then, in order to prevent the root rot of a plant, the artificial soil which combined the biodegradable plastic and the antibacterial agent is developed (for example, refer patent document 1 and patent document 2). The artificial soil of Patent Document 1 is obtained by dispersing an antibacterial agent in a biodegradable plastic. The artificial soil of Patent Document 2 is obtained by coating the surface of a biodegradable plastic with an antibacterial agent. According to the artificial soils of Patent Document 1 and Patent Document 2, microorganisms such as bacteria and moss are killed by the effect of the antibacterial agent contained in the artificial soil particles, and the plant is prevented from causing root rot during cultivation. When the antibacterial effect disappears, the biodegradable plastic that constitutes the artificial soil is decomposed by bacteria in the soil.

JP-A-9-183970 JP-A-9-183971

  In plants cultivated indoors, the aesthetics of artificial soil tend to be regarded as important as well as hygienic. In the stage of developing plant-cultivated products using artificial soil, the present inventors also expose the artificial soil to light when the plant is exposed to sunlight or illumination light. In addition to this, I encountered a new problem that a large amount of algae such as blue seaweed were generated. Algae are problematic in terms of hygiene because they produce more biofilm than bacteria and mosses. In addition, since algae has a dark green color, there is a problem that it is shunned in appearance. In an environment in which algae easily grow, it is considered difficult to completely prevent the generation of algae with artificial soil containing the antibacterial agents of Patent Document 1 and Patent Document 2.

  This invention is made | formed in view of the said problem, and it aims at providing the artificial soil particle which can suppress especially generation | occurrence | production of algae, such as a sea lion.

The characteristic configuration of the artificial soil particles according to the present invention for solving the above problems is as follows.
Artificial soil particles made up of a plurality of fillers having pores,
A communicating hole is formed between the fillers, and at least a region extending from the opening of the communicating hole to the particle surface is loaded with titanium oxide that functions as an anti-algae and fungicide.

The photocatalytic function of titanium oxide has been used mainly for the purpose of antibacterial and antifouling, but the present inventors have focused on the fact that titanium oxide is also effective in suppressing the generation of algae such as blue sea bream. The idea was to apply it to artificial soil where hygiene and aesthetics are required.
That is, the artificial soil particle of this configuration is a collection of a plurality of fillers having pores, and carries titanium oxide that functions as an anti-algae and fungicide. Here, titanium oxide is supported at least in a region extending from the opening of the communication hole formed between the fillers to the particle surface. Since it is such a supporting form, when sunlight or illumination light is applied to the cultivated plant, the artificial soil particles are easily exposed to light, and the photocatalytic function of titanium oxide can be effectively exhibited.
Therefore, cultivation of foliage plants etc. using artificial soil particles of this structure prevents contamination and coloring of artificial soil due to the generation of algae such as sea lions, and the hygienic state and aesthetics at the beginning of use are prolonged. It can be used as maintained artificial soil with high commercial value.

In the artificial soil particles according to the present invention,
The pores preferably have a size in the order of sub-nm to sub-μm, and the communication holes preferably have a size in the order of sub-μm to sub-mm.

  According to the artificial soil particle of this configuration, since the pore diameter of the pores of the filler is on the order of sub-nm to sub-μm, it is possible to effectively incorporate nutrients necessary for improving the quality of plants into the pores. it can. Moreover, since the hole diameter of the communicating hole formed between the aggregated fillers is on the order of sub-μm to sub-mm, moisture essential for the growth of plants can be effectively absorbed into the communicating hole. In this way, the artificial soil particles with this configuration can demonstrate the basic performance of soil in a well-balanced manner (that is, excellent balance between water retention and fertilizer retention), and realize high-quality and functional artificial soil. can do. Moreover, since the artificial soil particle of this structure can supply a water | moisture content and nutrients appropriately with respect to the plant of cultivation object, it does not take a maintenance effort and becomes easy to handle.

In the artificial soil particles according to the present invention,
The titanium oxide is preferably titanium oxide fine particles having a particle size smaller than the size of the communication hole.

  According to the artificial soil particles of this configuration, the titanium oxide fine particles can be supported inside the communication holes by using the titanium oxide fine particles having a particle size smaller than the size of the communication holes. The communication holes are rich in moisture and are particularly prone to algae and moss generation, but the photocatalytic effect of the titanium oxide particles supported inside the communication holes effectively suppresses the generation of algae and moss. Can prevent contamination and coloring of artificial soil.

In the artificial soil particles according to the present invention,
It is preferable that 0.1 to 70% by weight of the titanium oxide is supported.

  According to the artificial soil particles of this configuration, the effective amount of titanium oxide is supported, so that contamination and coloring of the artificial soil by algae and moss can be effectively prevented.

In the artificial soil particles according to the present invention,
It is preferable to further contain an antibacterial agent containing a substance different from the titanium oxide as an active ingredient.

  According to the artificial soil particles of this structure, in addition to the titanium oxide that functions as an anti-algae fungicide, it contains an antibacterial agent containing a substance different from titanium oxide as an active ingredient. The antibacterial effect can be exerted with respect to a portion where sufficient resistance is not exhibited (that is, a portion where light does not reach). Moreover, since the synergistic effect of a titanium oxide and an antibacterial agent can also be anticipated, the usage-amount of a chemical | medical agent can be reduced.

In the artificial soil particles according to the present invention,
It is preferable that ion exchange capacity is imparted to the pores.

  According to the artificial soil particle of this structure, the fertilizing property of the artificial soil particle can be improved by imparting ion exchange ability to the pores, and the labor for supplementing nutrients to the cultivated plant can be reduced.

In the artificial soil particles according to the present invention,
It preferably has a particle size of 0.2 to 10 mm.

  According to the artificial soil particle of this structure, the easy-to-handle artificial soil especially suitable for cultivation of root vegetables can be implement | achieved by making a particle size into 0.2-10 mm.

The characteristic configuration of the artificial soil particles according to the present invention for solving the above problems is as follows.
A base formed by agglomerating fibers,
A coating layer covering the base;
Artificial soil particles with
That is, at least the coating layer carries titanium oxide that functions as an anti-algae and fungicide.

Artificial soil particles of this configuration are provided with a base and a coating layer, but at least the coating layer carries titanium oxide that functions as an anti-algae and fungicide, so that the cultivated plant is exposed to sunlight or illumination light. , The artificial soil particles are easily exposed to light, and the photocatalytic function of titanium oxide can be effectively exhibited.
When cultivating foliage plants using artificial soil particles of this configuration, contamination and coloring of artificial soil due to the generation of algae such as blue-green algae is prevented, and the hygienic state and aesthetics at the beginning of use are maintained for a long time. It can be used as artificial soil with high commercial value.

FIG. 1 is a conceptual diagram of artificial soil particles. FIG. 2 is a partially enlarged view of the artificial soil particles carrying titanium oxide.

  Hereinafter, the embodiment regarding the artificial soil particle which concerns on this invention is described based on FIGS. 1-2. However, the present invention is not intended to be limited to the configurations described in the embodiments and drawings described below.

  FIG. 1 is a conceptual diagram of an artificial soil particle 50 according to the present invention, and illustrates two types of artificial soil particles 51 and 52 having different base 10 configurations.

[Artificial soil particles based on filler]
An artificial soil particle 51 in FIG. 1A is a first type of artificial soil particle, and includes a porous body 11 as a base 10. The porous body 11 is constituted by a plurality of fillers 1 gathered to form a granular shape. In the porous body 11, it is not essential that the plurality of fillers 1 are in contact with each other, as long as they maintain a relative positional relationship within a certain range via a binder or the like within one particle. It can be considered that a plurality of fillers 1 are aggregated to become granular.

  The particle size of the artificial soil particles 51 is 0.2 to 10 mm, preferably 0.5 to 5 mm, and more preferably 1 to 5 mm. The adjustment of the particle size of the artificial soil particles 51 can be performed by classification with a sieve, for example. When the particle size of the artificial soil particles 51 is less than 0.2 mm, the gap between the artificial soil particles 51 becomes small and the drainage performance decreases, so that the plant to be cultivated may not easily absorb oxygen from the roots. On the other hand, if the particle size of the artificial soil particles 51 exceeds 10 mm, the gap between the artificial soil particles 51 becomes large and the drainage property becomes excessive, so that it becomes difficult for the plant to absorb moisture, or the artificial soil particles 51 There is a risk that the plant will fall on its side. The particle diameter of the artificial soil particles 51 can be measured using, for example, optical microscope observation and an image processing method.

  The filler 1 constituting the porous body 11 of the artificial soil particles 51 has a large number of pores 2 from the surface to the inside. The pore 2 includes various forms. For example, when the filler 1 is the zeolite shown in FIG. 1, the voids present in the crystal structure of the zeolite are the pores 2. Moreover, when the filler 1 is a hydrotalcite (not shown), the interlayer which exists in the layer structure of the said hydrotalcite is a pore. That is, in the present invention, “pores” mean voids, interlayers, spaces, etc. existing in the structure of the filler 1, and these are not limited to “pore-like” forms.

  The size of the pores 2 of the filler 1 is on the order of sub-nm to sub-μm. When the filler 1 is the zeolite shown in FIG. 1 (a), the size (diameter) of the voids present in the crystal structure of the zeolite is about 0.3 to 1.3 nm. When the filler 1 is hydrotalcite, the size (distance) between the layers present in the layer structure of the hydrotalcite is about 0.3 to 3.0 nm. In addition, an organic porous material can also be used as the filler 1, and the pore diameter in that case is about 0.1 to 0.8 μm. The size of the pores 2 of the filler 1 is optimal using a gas adsorption method, a mercury intrusion method, a small-angle X-ray scattering method, an image processing method, or a combination of these methods depending on the state of the object to be measured. Measured by the method.

  Between the plurality of fillers 1, communication holes 3 of sub μm order to sub mm order capable of holding moisture are formed. The pores 2 are dispersedly arranged around the communication hole 3. Since moisture is mainly retained in the communication hole 3, the artificial soil particles 51 can have a certain water retention capacity. The size of the communication hole 3 (average value of the distance between the fillers 1) can vary depending on the type, composition, and granulation conditions of the filler 1 and the binder, but is on the order of sub μm to sub mm. When the filler 1 is the zeolite shown to Fig.1 (a), the size of the communicating hole 3 is 0.1-20 micrometers. The size of the communication hole 3 is measured by an optimal method using a gas adsorption method, a mercury intrusion method, a small-angle X-ray scattering method, an image processing method, or a combination of these methods depending on the state of the measurement object. can do.

  As the filler 1, it is preferable to use a material in which the ion exchange capacity is imparted to the pores 2 so that the artificial soil particles 51 have sufficient fertilizer. In this case, as the material imparted with ion exchange ability, a material imparted with cation exchange ability, a material imparted with anion exchange ability, or a mixture of both can be used. In addition, a porous material having no ion exchange ability (for example, a polymer foam, a glass foam, etc.) is prepared separately, and a material in which the ion exchange ability is imparted to the pores 2 of the porous material is prepared. It is possible to use the filler 1 by introducing it by press-fitting or impregnation. Examples of the material imparted with the cation exchange ability include cation exchange minerals, humus, and cation exchange resins. Examples of the material imparted with the anion exchange ability include anion exchange minerals and anion exchange resins.

  Examples of the cation exchange minerals include smectite minerals such as montmorillonite, bentonite, beidellite, hectorite, saponite, and stevensite, mica minerals, vermiculite, and zeolite. Examples of the cation exchange resin include a weak acid cation exchange resin and a strong acid cation exchange resin. Of these, zeolite or bentonite is preferable. The cation exchange mineral and the cation exchange resin can be used in combination of two or more. The cation exchange capacity of the cation exchange mineral and the cation exchange resin is set to 10 to 700 meq / 100 g, preferably 20 to 700 meq / 100 g, and more preferably 30 to 700 meq / 100 g. When the cation exchange capacity is less than 10 meq / 100 g, the nutrients cannot be taken in sufficiently, and the taken-up nutrients may be lost early due to irrigation or the like. On the other hand, even if the fertilizer is excessively increased so that the cation exchange capacity exceeds 700 meq / 100 g, the effect is not greatly improved and it is not economical.

  Anion-exchange minerals include, for example, natural layered double hydroxides that have double hydroxides as the main skeleton such as hydrotalcite, manaceite, pyroaulite, sjoglenite, patina, synthetic hydrotalcite and hydrotalcite-like Materials, clay minerals such as allophane, imogolite, kaolin and the like. Examples of the anion exchange resin include weakly basic anion exchange resins and strong basic anion exchange resins. Of these, hydrotalcite is preferred. An anion exchange mineral and an anion exchange resin can be used in combination of two or more. The anion exchange capacity of the anion exchange mineral and the anion exchange resin is set to 5 to 500 meq / 100 g, preferably 20 to 500 meq / 100 g, and more preferably 30 to 500 meq / 100 g. When the anion exchange capacity is less than 5 meq / 100 g, the nutrients cannot be taken in sufficiently, and the taken-up nutrients may be lost early due to irrigation or the like. On the other hand, even if the fertilizer is excessively increased so that the anion exchange capacity exceeds 500 meq / 100 g, the effect is not greatly improved and it is not economical.

  In the case where the filler 1 is an inorganic mineral such as zeolite or hydrotalcite, the gelation reaction of the polymer gelling agent is suitable for assembling a plurality of fillers 1 to form a granular material (artificial soil particle 51). Used for Examples of the gelation reaction of the polymer gelling agent include a gelation reaction between an alginate and a polyvalent metal ion, a gelation reaction of carboxymethylcellulose (CMC), and a gel formed by a double helical structure reaction of a polysaccharide such as carrageenan. Reaction. Among these, the gelation reaction between an alginate and a polyvalent metal ion will be described. Sodium alginate, which is one of alginates, is a neutral salt in which the carboxyl group of alginic acid is bonded to Na ions. Alginic acid is not required in water, but sodium alginate is water soluble. When an aqueous sodium alginate solution is added to an aqueous solution of polyvalent metal ions (for example, Ca ions), ionic crosslinking occurs between the molecules of sodium alginate and gelation occurs. In the case of this embodiment, the gelation reaction can be performed by the following steps. First, an alginate aqueous solution is prepared by dissolving alginate in water, filler 1 is added to the alginate aqueous solution, and this is sufficiently stirred to form a mixed solution in which filler 1 is dispersed in the alginate aqueous solution. . Next, the mixed solution is dropped into the polyvalent metal ion aqueous solution, and the alginate contained in the mixed solution is gelled in a granular form. Thereafter, the gelled particles are collected, washed with water, and sufficiently dried. Thereby, the artificial soil particle 51 as the granular material which the filler 1 disperse | distributed in the alginic acid gel formed from an alginate and a polyvalent metal ion is obtained.

  Examples of alginates that can be used in the gelation reaction include sodium alginate, potassium alginate, and ammonium alginate. These alginate can be used in combination of two or more. The concentration of the alginate aqueous solution is 0.1 to 5% by weight, preferably 0.2 to 5% by weight, and more preferably 0.2 to 3% by weight. When the concentration of the alginate aqueous solution is less than 0.1% by weight, the gelation reaction hardly occurs. When the concentration exceeds 5% by weight, the viscosity of the alginate aqueous solution becomes too large. In addition, it is difficult to drop the mixed solution into the aqueous solution of the polyvalent metal ion.

  The polyvalent metal ion aqueous solution to which the alginate aqueous solution is dropped may be a divalent or higher metal ion aqueous solution that reacts with the alginate and causes gelation. Examples of such polyvalent metal ion aqueous solutions include aqueous chloride solutions of polyvalent metals such as calcium chloride, barium chloride, strontium chloride, nickel chloride, aluminum chloride, iron chloride, cobalt chloride, calcium nitrate, barium nitrate, aluminum nitrate. Nitrate aqueous solutions of polyvalent metals such as iron nitrate, copper nitrate and cobalt nitrate, lactate aqueous solutions of polyvalent metals such as calcium lactate, barium lactate, aluminum lactate and zinc lactate, aluminum sulfate, zinc sulfate, cobalt sulfate etc. An aqueous solution of a valent metal sulfate is mentioned. These polyvalent metal ion aqueous solutions can be used in combination of two or more. The concentration of the polyvalent metal ion aqueous solution is 1 to 20% by weight, preferably 2 to 15% by weight, and more preferably 3 to 10% by weight. When the concentration of the polyvalent metal ion aqueous solution is less than 1% by weight, the gelation reaction hardly occurs. When the concentration exceeds 20% by weight, it takes time to dissolve the metal salt and excessive materials are used. Not economical.

  The granulation of the filler 1 for forming the artificial soil particles 51 can be performed by a granulation method using a binder in addition to the gelation reaction described above. For example, a filler or a solvent is added to the filler 1 and mixed, the mixture is introduced into a granulator, rolling granulation, fluidized bed granulation, agitation granulation, compression granulation, extrusion granulation, extrusion granulation, crushing It can carry out by well-known granulation methods, such as granulation, melt granulation, and spray granulation. The obtained granulated body is dried and classified as necessary, and the artificial soil particles 51 are completed. In addition, a binder is added to the filler 1 and, if necessary, a solvent or the like is added and kneaded, and the resulting dried and block-shaped material is appropriately pulverized by pulverizing means such as a mortar and pestle, a hammer mill, a roll crusher or the like. It is also possible to obtain a granular material. This granular material can be used as the artificial soil particle 51 as it is, but it is preferable to adjust to a desired particle size by sieving.

  As the binder, either an organic binder or an inorganic binder can be used. Organic binders include, for example, synthetic resin binders such as polyolefin binders, polyvinyl alcohol binders, polyurethane binders, polyvinyl acetate binders, polysaccharides such as starch, carrageenan, xanthan gum, gellan gum, alginic acid, and animal properties such as glue. Examples include natural product-based binders such as proteins. Examples of the inorganic binder include silicate binders such as water glass, phosphate binders such as aluminum phosphate, borate binders such as aluminum borate, and hydraulic binders such as cement. An organic binder and an inorganic binder can be used in combination of two or more.

  In the case where the filler 1 is an organic porous material, the artificial soil particles 51 may be formed by the same method as the above-described filler granulation method using a binder, but the filler 1 constitutes the filler 1. It is also possible to form artificial soil particles 51 by heating to a temperature equal to or higher than the melting point of the organic porous material (polymer material or the like) to be fused and granulating the surfaces of the plurality of fillers 1 by heat fusion. is there. In this case, a granular material in which a plurality of fillers 1 are assembled can be obtained without using a binder. As such an organic porous material, for example, an organic polymer foam obtained by foaming an organic polymer material such as polyethylene, polypropylene, polyurethane, polyvinyl alcohol, and cellulose, and the powder of the organic polymer material is heated and melted. An organic polymer porous body having an open cell structure is exemplified.

  Although not shown, a coating layer similar to the second type artificial soil particles 52 described later can be provided on the outer surface of the base portion 10 (porous body 11) of the artificial soil particles 51. By the coating layer, the moisture absorption / release characteristics of the artificial soil particles 51 can be controlled more precisely.

[Artificial soil particles based on fiber block]
The artificial soil particle 52 in FIG. 1B is a second type of artificial soil particle, and includes a fiber block 12 as the base 10. The fiber lump 12 is a collection of a plurality of fibers 4. Gaps 5 are formed between the fibers 4 constituting the fiber lump 12. The fiber lump 12 can retain moisture in the gap 5. Accordingly, the state of the gap 5 in the fiber lump 12 is related to the water retention of the fiber lump 12. The state of the gap 5 can be adjusted by changing the amount (density) of the fibers 4 used when forming the base 10, the type, thickness, length, and the like of the fibers 4. In addition, the size of the fiber 4 is preferably 5 to 100 μm in thickness, and preferably 0.5 to 10 mm in length.

  Since the fiber lump 12 is configured so that moisture can be retained therein, it is preferable to use a hydrophilic fiber as the fiber 4. As the type of the fiber 4, a natural fiber or a synthetic fiber is appropriately selected. Examples of preferable hydrophilic fibers include cotton, wool, and rayon as natural fibers, and examples of synthetic fibers include vinylon, urethane, nylon, and acetate. Of these, cotton and vinylon are more preferable. What mixed the natural fiber and the synthetic fiber may be used.

  When configuring the fiber lump 12, it is also possible to introduce another water retention material (hereinafter referred to as a second water retention material in order to distinguish it from the fibers 4 that are water retention materials) between the fibers 4. . In this case, the fiber lump 12 can be provided with water retention by the second water retention material in addition to the water retention by the gaps 5 between the fibers 4 that are originally present. As a method for introducing the second water-retaining material into the fiber lump 12, for example, the fiber lump 12 that forms the base 10 is formed by granulating the fibers 4, and the second water-retaining material is added during the granulation. Moreover, you may coat the surface of the fiber 4 with a 2nd water retention material. The second water-retaining material introduced into the fiber mass 12 by these methods is preferably exposed in the gaps 5 between the fibers 4. In this case, the fiber lump 12 greatly improves the water retention capacity of the gap 5.

  As the second water retaining material, a polymer water retaining material having water absorption can be used. For example, polyacrylate polymer, polysulfonate polymer, polyacrylamide polymer, polyvinyl alcohol polymer, polyalkylene oxide polymer and other synthetic polymer water retention materials, polyaspartate polymer, polyglutamate Natural polymer water-retaining materials such as polymer, polyalginate polymer, cellulose polymer and starch. These 2nd water retention materials can also be used in combination of 2 or more types. Further, a porous material such as ceramics can be used as the second water retention material.

  The fiber lump 12 is formed by a known granulation method. For example, long fibers are aligned with a carding device or the like, cut to a length of about 3 to 10 mm, and the produced fibers are tumbled granulated, fluidized bed granulated, stirred granulated, compressed granulated, extruded granulated, etc. It forms by granulating by the method of. During granulation, the fiber 4 may be mixed with a binder such as a resin or glue, but the fibers 4 are entangled with each other and easily fixed, so that the fibers 4 are agglomerated even when no binder is used. Can be processed.

  As shown in FIG. 1B, a coating layer 20 is formed on the outer surface of the fiber lump 12 configured as the base 10. By providing the coating layer 20, the fiber lump 12 can be prevented from being rapidly dried and the moisture absorption / release characteristics can be controlled. The coating layer 20 is a film having ultrafine pores through which water molecules can pass. Or it can also be set as the permeable membrane which water | moisture content permeates from one side and can move to the other side. The coating layer 20 is formed on the outer surface portion of the fiber lump 12 by the following method, for example. First, the granulated fiber lump 12 is transferred to a container, and water about half the volume (occupied volume) of the fiber lump 12 is added, so that water is immersed in the gap 5 of the fiber lump 12. Next, a resin emulsion of 1/3 to 1/2 of the volume of the fiber lump 12 is added to the fiber lump 12 soaked with water. Additives such as pigments, fragrances, bactericides, antibacterial agents, deodorants, and insecticides may be mixed in the resin emulsion. Next, the resin emulsion is impregnated from the outer surface of the fiber lump 12 while rolling so that the resin emulsion uniformly adheres to the outer surface of the fiber lump 12. At this time, since the water has soaked into the center of the fiber lump 12, the resin emulsion remains near the outer surface of the fiber lump 12. Thereafter, the fiber lump 12 to which the resin emulsion is adhered is dried in an oven, the resin is then melted, and the resin is fused to the fibers 4 near the outer surface of the fiber lump 12 to form a resin film as the coating layer 20. Form. Thereby, the outer surface of the fiber lump 12 is covered with the coating layer 20, and the artificial soil particles 52 are completed. In the coating layer 20, when the resin is melted, the solvent contained in the resin emulsion is evaporated, and a porous structure is formed. The obtained artificial soil particles 52 are dried and classified as necessary to adjust the particle size. The covering layer 20 has a thickness that is slightly infiltrated inward from the outer surface of the fiber lump 12 so as to reinforce the entangled portions of the fibers 4 constituting the fiber lump 12 (the portions where the fibers 4 contact each other). It may be formed. Thereby, the strength and durability of the artificial soil particles 52 can be improved. The film thickness of the coating layer 20 is set to 1 to 200 μm, preferably set to 10 to 100 μm, and more preferably set to 20 to 60 μm. The covering layer 20 may be provided as necessary, and the fiber lump 12 without the covering layer 20 may be used as the artificial soil particle 52 as it is.

  In granulating the fiber lump 12, it is possible to use short fibers as the fibers 4. In this case, the resin emulsion is added in small amounts and granulated while stirring the short fibers with a stirring and mixing granulator. Thereby, the short fibers forming the fiber lump 12 are partially fixed, and the strong base 10 can be formed. It is also possible to add water to the short fibers and granulate them first, and then add an emulsion to the coating layer 20 to finish the fiber mass 12.

  The material of the covering layer 20 is preferably insoluble in water and hardly oxidized, and examples thereof include a resin material. Examples of such a resin material include polyolefin resins such as polyethylene and polypropylene, vinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride, polyester resins such as polyethylene terephthalate, and styrene resins such as polystyrene. Of these, polyethylene is preferred. In place of the resin material, a synthetic polymer gelling agent such as polyethylene glycol or a natural gelling agent such as sodium alginate can be used.

  The fiber block 12 and the coating layer 20 can also be provided with ion exchange capacity. By providing ion exchange capacity to at least one of the fiber lump 12 and the coating layer 20, the artificial soil particles 52 can support a fertilizer component necessary for plant growth, so that the plant is equivalent to natural soil. It becomes possible to realize artificial soil having a growing ability.

[Support of titanium oxide on artificial soil particles]
Titanium oxide, known as a photocatalyst, has been used mainly for the purpose of antibacterial and antifouling, but the photocatalytic function of titanium oxide is to prevent the generation of moss and the generation of algae such as blue-green algae. It is also very effective for suppression. Then, the present inventors examined the application to the artificial soil in which hygienic aspect and aesthetics are requested | required as a new use of a titanium oxide. FIG. 2 is a partially enlarged view of the artificial soil particle 50 of the present invention carrying the titanium oxide 6. The titanium oxide 6 supported on the artificial soil particles 50 functions as an algae and fungicide.

  FIG. 2A shows an artificial soil particle 50 carrying titanium oxide 6 and corresponds to the artificial soil particle 51 shown in FIG. In the dotted circle of FIG. 2A, the vicinity of the surface of the artificial soil particle 51 is shown in an enlarged state. As the titanium oxide 6, titanium oxide fine particles 6 a having an anatase type crystal structure commercially available for photocatalyst can be used.

  As described above, the artificial soil particle 51 includes the porous body 11 as the base 10 formed by a plurality of fillers 1 having the pores 2, and in the porous body 11, between the fillers 1. A communication hole 3 is formed. Here, although the titanium oxide fine particles 6a may be carried on the whole artificial soil particles 51, as shown in FIG. 2A, at least in the region extending from the opening 3a of the communication hole 3 to the particle surface 51a. It must be supported. If it is such a carrying | support form, when it exposes to the sunlight and illumination light to the plant cultivated by artificial soil, it will become easy to hit light also to the titanium oxide fine particle 6a carry | supported by the artificial soil particle 51 which comprises artificial soil. Then, the photocatalytic function of the titanium oxide fine particles 6a is effectively exerted, and the generation of algae such as moss and blue-green algae is prevented. As a result, contamination and coloring of the artificial soil can be prevented, and the hygienic state and aesthetics at the beginning of use can be maintained for a long time.

  The size (particle diameter) of the titanium oxide fine particles 6a is preferably smaller than the size (pore diameter) of the communication hole 3. For example, when the filler 1 is zeolite, the size of the communication hole 3 is about 0.1 to 20 μm. In this case, titanium oxide fine particles having a particle size of 0.005 to 10 μm can be used. With such a size relationship, since the titanium oxide fine particles 6a can be carried inside the communication hole 3, in the vicinity of the communication hole 3 in an environment where algae and moss are easily generated due to the presence of a large amount of water, The photocatalytic effect (anti-algae and anti-fungal effect) by the titanium oxide fine particles 6a acts directly, and it is possible to effectively prevent contamination and coloring of artificial soil by algae and moss.

  The supported amount (content) of the titanium oxide fine particles 6a in the artificial soil particles 51 is 0.1 to 70% by weight, preferably 0.1 to 30% by weight, and more preferably 0.5 to 20% by weight. If it is this range, the contamination and coloring of the artificial soil by algae can be prevented effectively. If the supported amount of the titanium oxide fine particles 6a is less than 0.1% by weight, the photocatalytic function of the titanium oxide fine particles 6a may not be sufficiently exhibited. On the other hand, if the loading amount of the titanium oxide fine particles 6a is more than 70% by weight, the function of the artificial soil is not affected, but a large amount of the titanium oxide fine particles 6a are contained in the artificial soil particles 51 that are difficult to receive light. Therefore, it is inefficient as an anti-algae fungicide and is disadvantageous in terms of cost.

  As a method for supporting the titanium oxide fine particles 6 a on the artificial soil particles 51, the titanium oxide fine particles 6 a are mixed with the filler 1 in the step of granulating the filler 1. For example, when the filler 1 is granulated by utilizing the gelation reaction between the alginate and the polyvalent metal ion described above, the filler 1 and the titanium oxide fine particles 6a are dispersed in the alginate aqueous solution, and the dispersion is polyvalent. It is dropped into an aqueous metal ion solution. Then, the alginate gels in a granular state in a state where the filler 1 and the titanium oxide fine particles 6a are mixed, and artificial soil particles 51 carrying the titanium oxide fine particles 6a are generated. Moreover, in the granulation method of the filler 1 using a binder, the titanium oxide fine particles 6a may be mixed with the filler 1 or the binder. In this case, the filler 1 and the titanium oxide fine particles 6a are granulated through a binder, and artificial soil particles carrying the titanium oxide fine particles 6a are generated.

  FIG. 2B shows the artificial soil particles 50 carrying the titanium oxide 6 and corresponds to the artificial soil particles 52 shown in FIG. In the dotted circle of FIG. 2 (b), the surface vicinity of the artificial soil particle 52 is shown in an enlarged state. As the titanium oxide 6, titanium oxide fine particles 6a having an anatase type crystal structure that are commercially available for photocatalysts can be used, and those similar to those described in FIG.

  As described above, the artificial soil particle 52 includes the base portion 10 in which the fibers 4 are aggregated in a lump shape and the coating layer 20 that covers the base portion 10. Here, the titanium oxide fine particles 6a may be carried over the entire base 10 and the coating layer 20, but as shown in FIG. 2 (b), at least the coating layer 20 needs to be carried. . At this time, the titanium oxide fine particles 6a may be supported on the surface of the coating layer 20, or when the coating layer 20 is translucent, the titanium oxide fine particles 6a are contained inside the coating layer 20. It does not matter even if it is kneaded. If it is such a carrying | support form, when it exposes to the sunlight and illumination light to the plant cultivated by artificial soil, it will become easy to hit light also to the titanium oxide fine particle 6a carry | supported by the artificial soil particle 52 which comprises artificial soil. Then, the photocatalytic function of the titanium oxide fine particles 6a is effectively exerted, and the generation of algae such as moss and blue-green algae is prevented. As a result, contamination and coloring of the artificial soil can be prevented, and the hygienic state and aesthetics at the beginning of use can be maintained for a long time.

  The artificial soil particles 51 and 52 carry titanium oxide fine particles 6a that function as an anti-algae and fungicide. In addition to titanium oxide, the artificial soil particles 51 and 52 include other substances having an active ingredient other than titanium oxide. It is also possible to carry an antibacterial agent. For example, in the artificial soil particle 51, an antibacterial agent can be carried on the entire porous body 11 constituting the base 10. In the artificial soil particles 52, an antibacterial agent can be carried in the gaps 5 between the fibers 4 constituting the base 10. Combining titanium oxide with other antibacterial agents can prevent the occurrence of wrinkles even in the artificial soil particles 51 and 52 that are difficult to receive light. Furthermore, since a synergistic effect between titanium oxide and the antibacterial agent can be expected, the amount of the drug used can be reduced. As an antibacterial agent that can be combined with titanium oxide, from the viewpoint of stability in soil and safety to cultivated plants, for example, inorganic substances containing metal ions such as silver, copper, zinc, nickel, etc. have antibacterial properties Synthetic antibacterial agents such as zeolite, paraben and butanediol, and natural antibacterial agents such as catechin, chitin and chitosan can be used.

  The artificial soil particles of the present invention carrying titanium oxide that functions as an algal and fungicidal agent were examined for the algal and algal inhibitory effects. As the artificial soil particles, mixed fine particles (Examples 1 to 21, Comparative Example 1) in which titanium oxide is supported on the base [1] corresponding to the artificial soil particles 51 shown in FIGS. 1 (a) and 2 (a). To 4), and [2] coating fine particles in which titanium oxide is supported on the coating layer covering the base portion corresponding to the artificial soil particles 52 shown in FIGS. 1B and 2B (Examples 22 to 48, Comparative Examples 5 and 6) were prepared.

  For mixed fine particles (Examples 1 to 21, Comparative Examples 1 to 4), Table 1 and Table 2 show the materials used to construct the artificial soil particles and the characteristics of the prepared artificial soil particles. According to the formulation shown in Table 1 and Table 2, the mixture is prepared by mixing the filler and the anti-algae fungicide with the binder, and then the mixture is dropped into a 5% calcium chloride aqueous solution to form a gel. The chemicals were collected and dried to obtain artificial soil particles. In this artificial soil particle, the size of the communication hole was 0.3 μm, and the size of the supported titanium oxide fine particles was 70 nm. The shape of the artificial soil particles was measured by combining microscopic observation and an image processing method. As for the appearance of artificial soil particles, artificial soil particles are filled in a transparent pot, radish is planted as a plant, cultivated for 24 days while irrigating indoors where sunlight is inserted, The occurrence was confirmed. For water retention, 140 cc of artificial soil for measurement is placed in the chromatograph tube, water is sprayed from the top of the tube (10 ml x 5 times + 20 ml x 3 times), and water that the artificial soil has not absorbed is drained from the bottom of the tube. The amount of water retained was determined by measuring the weight of the artificial soil after a predetermined time.

The products used as “materials” in Tables 1 and 2 are shown below.
Zeolite: Artificial zeolite "Ryukyu Light CEC600" manufactured by Ecowell Co., Ltd.
Hydrotalcite: Reagent hydrotalcite manufactured by Wako Pure Chemical Industries, Ltd. Sodium alginate: Reagent sodium alginate manufactured by Wako Pure Chemical Industries, Ltd. Calcium chloride: Reagent calcium chloride manufactured by Wako Pure Chemical Industries, Ltd. Titanium oxide fine particles: Wako Pure Titanium oxide (anatase type) manufactured by Yakuhin Kogyo Co., Ltd.
Silver ion-containing inorganic material: Silver-based inorganic antibacterial agent “NOVALON (registered trademark) AGZ” manufactured by Toagosei Co., Ltd.
Antibacterial zeolite: Antibacterial zeolite "Ryukyu Light" manufactured by Ecowell Co., Ltd.
Ethylparaben: Reagent manufactured by Wako Pure Chemical Industries, Ltd. Ethylparaben Catechin: Reagent catechin manufactured by Wako Pure Chemical Industries, Ltd.

  From Tables 1 and 2, all of the artificial soil particles of the present invention of Examples 1 to 21 carrying titanium oxide fine particles had little occurrence of aquatic, and no generation of wrinkles was confirmed. On the other hand, in the artificial soil particles of Comparative Examples 1 to 4 that did not carry titanium oxide fine particles, aquatic was generated over the entire artificial soil, and generation of soot was also confirmed. In addition, the artificial soil particles of the present invention supporting titanium oxide fine particles maintain a level substantially equal to that of artificial soil particles not supporting titanium oxide fine particles in cation exchange capacity (CEC) and water retention, No performance degradation as artificial soil due to the loading of titanium oxide fine particles was observed. Therefore, it was confirmed that the artificial soil particles of the present invention can be handled as usual.

  Tables 3 to 5 show the materials used to construct the artificial soil particles and the characteristics of the prepared artificial soil particles for the coated fine particles (Examples 22 to 48, Comparative Examples 5 and 6). In accordance with the formulation shown in Tables 3 to 5, first, fine particles are prepared in the same manner as the above-mentioned mixed fine particles, and then a coating solution containing titanium oxide shown in Tables 3 to 5 is applied to the surface of the fine particles. Coated. The coated coating solution was dried or cured by a predetermined method to obtain artificial soil particles having a coating layer formed on the surface of the base. In this artificial soil particle, the size of the communication hole was 0.3 μm, and the size of the supported titanium oxide fine particles was 70 nm. The shape of the artificial soil particles, the appearance of the artificial soil particles, and the water retention measurement were the same as in the case of the mixed fine particles (Examples 1 to 21 and Comparative Examples 1 to 4).

The products used as “materials” in Tables 3 to 5 are shown below.
Talc: General-purpose talc “SW” manufactured by Nippon Talc Co., Ltd.
Diatomaceous earth: Diatomaceous earth "Radiolite (registered trademark) # 300" manufactured by Showa Chemical Industry Co., Ltd.
Cellulose fiber: Cellulose fiber "Abocel B800" manufactured by Showa Chemical Industry Co., Ltd.
Zeolite: Artificial zeolite "Ryukyu Light CEC600" manufactured by Ecowell Co., Ltd.
Hydrotalcite: Reagent manufactured by Wako Pure Chemical Industries, Ltd. Hydrotalcite Sodium alginate: Reagent sodium alginate manufactured by Wako Pure Chemical Industries, Ltd. Calcium chloride: Reagent calcium chloride, manufactured by Wako Pure Chemical Industries, Ltd. Vinyl acetate: Wako Pure Chemical Industries, Ltd. Vinyl acetate polyethylene emulsion manufactured by Kogyo Co., Ltd .: polyolefin emulsion “Sepoljon (registered trademark) G315” manufactured by Sumitomo Seika Co., Ltd.
Agar: Agar manufactured by Wako Pure Chemical Industries, Ltd. Titanium oxide fine particles: Reagent titanium oxide manufactured by Wako Pure Chemical Industries, Ltd. (anatase type)
Silver ion-containing inorganic material: Silver-based inorganic antibacterial agent “NOVALON (registered trademark) AGZ” manufactured by Toagosei Co., Ltd.
Antibacterial zeolite: Antibacterial zeolite "Ryukyu Light" manufactured by Ecowell Co., Ltd.
Ethylparaben: Reagent manufactured by Wako Pure Chemical Industries, Ltd. Ethylparaben Catechin: Reagent catechin manufactured by Wako Pure Chemical Industries, Ltd.

  From Tables 3 to 5, all of the artificial soil particles of Examples 22 to 48 of the present invention in which titanium oxide fine particles were supported on the coating layer were less likely to cause aquatic growth, and no occurrence of soot was observed. On the other hand, in the artificial soil particles of Comparative Examples 5 and 6 in which the titanium oxide fine particles were not supported on the coating layer, aquatic was generated over the entire artificial soil, and generation of soot was also confirmed. In addition, the artificial soil particles of the present invention in which titanium oxide fine particles are supported on the coating layer maintain substantially the same level as artificial soil particles not supporting titanium oxide in cation exchange capacity (CEC) and water retention. The performance as artificial soil due to the loading of titanium oxide fine particles was not observed. Therefore, it was confirmed that the artificial soil particles of the present invention can be handled as usual.

  The artificial soil particles of the present invention are suitably used as artificial soil and interior soil used in plant factories, etc., but as other uses, for facility horticultural soil, greening soil, molded soil, soil improver Is also available.

DESCRIPTION OF SYMBOLS 1 Filler 2 Fine pore 3 Communication hole 3a Opening part of communication hole 4 Fiber 5 Cavity 6 Titanium oxide 6a Titanium oxide fine particle 10 Base 11 Porous body 12 Fiber aggregate 50 Artificial soil particle 51 Artificial soil particle 51a Particle surface 52 Artificial soil particle

Claims (8)

Artificial soil particles made up of a plurality of fillers having pores,
Artificial soil particles in which communication holes are formed between the fillers, and titanium oxide that functions as an antialgal and fungicidal agent is supported at least in a region extending from the opening of the communication holes to the particle surface.   2. The artificial soil particle according to claim 1, wherein the pores have a size of sub nm order to sub μm order, and the communication holes have a size of sub μm order to sub mm order.   The artificial soil particles according to claim 2, wherein the titanium oxide is titanium oxide fine particles having a particle size smaller than the size of the communication hole.   The artificial soil particles according to any one of claims 1 to 3, wherein the titanium oxide is supported by 0.1 to 70% by weight.   The artificial soil particle according to any one of claims 1 to 4, further comprising an antibacterial agent containing a substance different from the titanium oxide as an active ingredient.   The artificial soil particles according to any one of claims 1 to 5, wherein ion exchange capacity is imparted to the pores.   The artificial soil particle according to any one of claims 1 to 6, which has a particle size of 0.2 to 10 mm. A base formed by agglomerating fibers,
A coating layer covering the base;
Artificial soil particles with
Artificial soil particles in which titanium oxide that functions as an anti-algae and fungicide is supported on at least the coating layer.

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