JPH0576241A - Artificial soil - Google Patents

Abstract

PURPOSE:To obtain inexpensive artificial soil suitable for plant culture, having air permeability and excellent water retention, comprising a mixture of aggregated particle structure comprising inorganic particles having a specific average particle diameter of single particle and a specific amount of an organic adhesive, by reclaiming waste liquor of coating material in paper-making processing. CONSTITUTION:(B) 2-30wt.% based on total solid content of a blend of polyvinyl alcohol : butadiene styrene-based synthetic rubber latex in a ratio of 1 : 2 as an organic adhesive if added to (A) inorganic particles such as kaolin or talc having <=50mum average particle diameter of single particle and blended with water and sodium acrylate as a dispersant while stirring to give 40% suspension. The suspension is dried in the sun and ground to give the objective artificial soil suitable for culture of plant, having aggregated particle structure, 20-120% water retention characteristics of aggregated particle structure, 0.3-1.0 bulk specific gravity and excellent air permeability and water retention characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil for cultivating plants, and more particularly to an artificial soil having a proper water retention property and good air permeability.

[0002]

2. Description of the Related Art Generally, plants are grown in soil. This soil includes natural products such as Akadama soil, Kanuma soil, rice field soil, river sand, sand sand soil, pumice stone, moss, peat moss, and artificial soil such as perlite and vermiculite.
It has fertilizing properties) and is used by mixing the soil depending on the plant or by compounding a soil improver such as mulch or compost.

However, in recent years, the problem of conservation of nature has been screaming strongly, and the extraction of natural products is restricted. Also, artificial soils such as perlite and vermiculite are limited in quantity because they use natural pearlite and vermiculite as raw materials, and these are extremely expensive soils because they are treated at high temperatures of 400 to 600 ° C. ing.

On the other hand, as the number of people who love flowers at the World Exposition of Flowers has increased, the amount of soil used has been increasing, and there is a possibility of tightness in the future. In particular, with the rapid growth of home gardens, the emergence of inexpensive artificial soil is expected for plant cultivation in urban areas.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a soil for cultivating a plant, and in particular, provides an inexpensive artificial soil which has an appropriate water retention property, and has good air permeability.

[0006]

Means for Solving the Problems The present invention is an artificial soil comprising a mixture of inorganic particles and an organic adhesive, wherein the average particle size of the inorganic particles is 50 μm or less, and the organic adhesive has a total solid content. On the other hand, the artificial soil is characterized by having an aggregate structure containing 2 to 30% by weight.

[0007]

In the present invention, the inorganic particles and the organic adhesive are well mixed to form a coating of the organic adhesive on the surface of the inorganic particles, which is concentrated or dehydrated and dried, and the coated particles are bonded together to form a group. Make grains. The aggregate is crushed to an appropriate diameter to obtain an artificial soil having an aggregate structure.

In the present invention, inorganic particles having an average particle size of 50 μm or less are used. The average particle size of single particles of inorganic particles influences the amount of small crevices in the aggregate structure and affects the water retention of soil. That is, the smaller the average particle size of the single particles of the inorganic particles, the more the small gaps can be increased, and the higher the water retention of the soil becomes.

When inorganic particles having an average particle diameter of 50 μm or less are used and the kind and content of the organic adhesive are adjusted, a water-retentive aggregate structure having a water content of 20 to 120% can be obtained.
By the way, if the average particle size of inorganic particles exceeds 50 μm and becomes coarse particles, the water retention becomes too low, less than 20%, and watering and irrigation are often performed for general plant cultivation, which is unsuitable. Is. On the other hand, soil with a water retention of more than 120% has poor water scavenging and is not suitable for general plants. Therefore, in the present invention, in such a case, the content of the organic adhesive is adjusted. Very fine inorganic particles having a single-particle average particle size of 0.1 μm or less may be used at times, but these do not usually become single particles and the particle size has already been measured as agglomerated aggregates. In many cases, it is difficult to limit the fine particles. There are many methods for measuring the average particle size, and the numerical values may differ slightly depending on the measuring method.
The fact that the average particle size of the single particles is 50 μm does not cause a difference due to the measuring method, and is shown by various measuring methods, which is generally judged by microscopic observation.

The types of inorganic particles used in the present invention include, for example, calcium carbonate, magnesium carbonate, calcium-magnesium carbonate, silicic acid salt, silicic acid, aluminum hydrate, calcium sulfate, calcium sulfite, titanium dioxide and zinc pigment. Etc. or kaolin, talc, wax clay, cerisite, which are commonly used in the paper industry,
Activated clay and the like are used alone or in combination.

Further, waste inorganic particles generated in the process of manufacturing or using these are also included, and are not particularly limited, but in order to obtain inexpensive soil, they are generated in the process of manufacturing or using. It is preferable to collect and reuse the waste inorganic particles.

In the present invention, the organic adhesive is contained in the range of 2 to 30% by weight based on the total solids. When the average particle size of the inorganic particles is relatively large, close to 50 μm, the organic adhesive is added in a small amount of about 2% by weight based on the total solid content, and when the particle is 1 μm or finer particles, Three
A large amount is contained near 0% by weight. The average particle size of the single particles of the inorganic particles and the range in which the organic adhesive is contained with respect to the total solid matter are important because they are thus interrelated. According to the results of studies by the inventors, in order to coat the inorganic particles and to bond and bond the coated particles to each other, the organic adhesive needs to be contained in an amount of 2% by weight or more based on the total solids. When the content of the organic adhesive is less than 2% by weight based on the total solid content, the adhesive bond strength between the particles is weak and the particles cannot be solidified. However, if the organic adhesive exceeds 30% by weight with respect to the total solid content, the gaps between particles are filled with the adhesive, resulting in soil with poor water retention.

The types of organic adhesives used in the present invention include:
For example, starches, celluloses, water-soluble polysaccharides such as microbial polysaccharides, gelatin, casein, soybean protein, water-soluble protein such as gluten, polyvinyl alcohol, polyethylene oxide, sodium polyacrylate, polyacrylamide, polyamide polyamine epichlorohydrin Water-soluble synthetic polymer such as butadiene / styrene / butadiene /
Acrylonitrile, butadiene / methyl methacrylate, chloroprene, latex such as natural rubber, and thermosetting resin such as urea resin, melamine resin, phenol resin, and resorseal resin may be used alone or in combination. A synthetic rubber-based latex that is easy and has some water resistance is preferable.

In the present invention, first, the suspension of the above-mentioned inorganic particles and the organic adhesive is thoroughly mixed to cover the surface of the inorganic particles. Next, in order to obtain a dried product, it may be dried directly with heat or sunlight, or may be dehydrated and then dried with heat or sunlight. Also, if it is very difficult to dehydrate as it is,
It is preferable to coagulate and precipitate ferric chloride, sulfuric acid band, polyaluminum chloride, etc. to dehydrate the precipitate, and then dry it by heat or sunlight.

The dried product obtained is pulverized by a pulverizer and further sieved to obtain a predetermined aggregate particle size. This aggregate particle size is related to the large gap in which water drops and drains due to gravity when water is sprinkled on the soil. As the aggregate particle size increases, the large gap increases, and when the aggregate particle size decreases, the large gap decreases. .. Air is usually present in this large gap without water, which is associated with soil breathability.

The air permeability of this soil is associated with root rot that often occurs during plant cultivation, and if the air permeability is poor and the amount of air is small, root rot is likely to occur. Since the relationship between air permeability and root rot differs depending on the type of plant, the size of the aggregate particle size is selected according to the type of plant.

The aggregate diameter is generally 0.01 to 40 mm,
Although it is used in a range of approximately, the diameter of 0.1 to 4 mm is preferable for use as general purpose soil. Bulk specific gravity is convenient as an index of air permeability, and bulk specific gravity is measured for soil quality control. The artificial soil of the present invention may be adjusted to have a bulk specific gravity of 0.3 to 1.0. When the bulk specific gravity exceeds 1.0 and becomes high, the air permeability becomes poor. The bulk specific gravity of 1.0 or less has good air permeability. However, if the bulk specific gravity is less than 0.3, the gap between the aggregates is too large, which is not preferable as soil.

In the present invention, an artificial soil can be obtained by using the paint waste liquid containing the inorganic particles and the organic adhesive, which is produced from the manufacturing process in the papermaking process, alone or in combination. This paint waste liquid is subjected to coagulation precipitation of ferric chloride, sulfuric acid band, polyaluminum chloride, etc., the precipitate is dehydrated, dried by heat or sunlight, pulverized, and sieved. This is a preferred embodiment because the paint waste liquid, which has been industrial waste so far, is utilized, contributes to environmental pollution, and obtains inexpensive soil.

Antifungal agents, preservatives, plant fertilizers, nutrients and the like can be added to the artificial soil of the present invention as appropriate.
Of course, it is naturally performed to mix and mix the artificial soil to which these are not added at the time of use.

[0020]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition,% in an example shows weight%.

Example 1 Kaolin as an inorganic particle (average particle size of single particles: 1 μm)
In an amount of 75% with respect to the total solid content and polyvinyl alcohol: butadiene / styrene synthetic rubber latex as an organic adhesive in a ratio of 1: 2 in the water together with a dispersant (sodium acrylate) at 25% in water. Stir and mix, 40%
A suspension of concentration was obtained. This suspension was dried in the sun and pulverized to obtain dry soil having a particle size of 3 mm or less. As a result of the quality of this soil, the bulk specific gravity was 0.4 and the water retention was 100%, and the soil was good in both air permeability and water retention.

Example 2 As inorganic particles, talc (average particle size of single particles: 8 μm) was 85% with respect to the total solid content, and as an organic adhesive, oxidized starch:
The butadiene-acrylonitrile-based latex was stirred and mixed in water at a ratio of 1: 4 with a dispersant (sodium acrylate) at a concentration of 15% in water to obtain a suspension having a concentration of 40%. This suspension is dried in the sun and ground to a particle size of 3 mm.
The following dry soil was obtained. As a result, the bulk specific gravity is 0.55,
The water retention was 60% and the soil was good in both air permeability and water retention.

Example 3 As inorganic particles, gypsum (average particle size of single particles: 30 μm) was dispersed in 95% of the total solid content, and butadiene-styrene latex as an organic adhesive was dispersed in 5% of the total solid content. Stir-mix in water with agent (sodium acrylate), 40
A% strength suspension was obtained. The suspension was dried in the sun and pulverized to obtain a dry soil having an aggregate particle diameter of 3 mm or less. As a result, the bulk specific gravity was 0.80 and the water retention was 30%, and the soil was good in both air permeability and water retention.

Example 4 Kaolin as an inorganic particle (single particle average particle diameter: 0.47)
μm): calcium carbonate (average particle size of single particles: 0.40)
μm) in a ratio of 9: 1 to 85% of the total solid content, and as an organic adhesive, a ratio of oxidized starch: butadiene / styrene latex 1: 2 in a ratio of 15% to the total solid content of a coating liquid waste solution. use. Ferric chloride was added to this paint waste liquid to adjust the pH to 7 for coagulation-precipitation treatment, and the precipitate was filtered with a belt filter, dried in the sun, and ground to dry soil with a particle size of 3 mm or less. Got As a result, the bulk specific gravity was 0.65, and the water retention was 58%, indicating that the soil had good air permeability and water retention.

Comparative Example 1 Natural gypsum as inorganic particles (average particle size of single particles: 80 μm)
Same as Example 1 except that m) was used. As a result, the bulk specific gravity was 0.8, the water retention was 15%, and the soil had good air permeability but poor water retention.

Comparative Example 2 The procedure of Example 2 was repeated except that the inorganic particles were 99% and the organic adhesive was 1%. As a result, many of the aggregates had a small aggregate particle size, the bulk specific gravity was 1.5, and the water retention was 150%, and the soil was poor in both air permeability and water retention.

Comparative Example 3 The procedure of Example 3 was repeated except that the inorganic particles were 65% and the organic adhesive was 35%. As a result, the bulk specific gravity was 0.2 and the water retention was 10%, and both the air permeability and the water retention were poor soils not suitable for general plant cultivation by themselves. [Soil quality evaluation method] 1. Measurement method of bulk specific gravity-The sample is dried at 105 ° C to measure the water content (A
%).・ Weighing bottle of known weight (Bg) for sample (internal volume: 300 m
Fill 1) and measure its weight (Cg). Bulk specific gravity = (C−B) × (1−A / 100) ÷ 300 2. Method of measuring water retention-Sample is a poly pot of known weight (Dg) with a diameter of 9 cm (1 at the bottom
Put 250 ml in 50 mesh wire and weigh (Eg). -After immersing this plastic pot in water for 3 hours, take out the plastic pot and leave it to stand. After 1 hour, measure the weight of the plastic pot (Fg). Water retention = (FE) ÷ {(ED) × (1-A / 10
0)} × 100

[0028]

As is clear from the results of the examples, the soil obtained by the production method of the present invention was an artificial soil having both good air permeability and good water retention. In addition, by reusing the paint waste liquid from the paper manufacturing process, which is now an industrial waste, it was possible to obtain an artificial soil that is inexpensive and has excellent breathability and water retention and is suitable for plant cultivation.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Yoshino 4-3-1 Jōkoji, Amagasaki City, Hyogo Prefecture Kanzaki Paper Co., Ltd. Kanzaki Mill

Claims (4)

[Claims] 1. An artificial soil comprising a mixture of inorganic particles and an organic adhesive, wherein the average particle size of inorganic particles is 50 μm.
m or less, and the organic adhesive is 2 to 30 with respect to the total solid content.
An artificial soil characterized by having an aggregate structure containing wt%. 2. The artificial soil according to claim 1, wherein the water retention of the aggregate structure is 20 to 120%. 3. The artificial soil according to claim 1, wherein the bulk specific gravity of the aggregate structure is 0.3 to 1.0. 4. The artificial soil according to claim 1, wherein the organic adhesive is a synthetic rubber latex.