JPH0725680A - Porous granulated material - Google Patents

Abstract

PURPOSE:To strengthen the action of chitosan and prolong the duration thereof by adsorbing the chitosan on a porous granulated material. CONSTITUTION:A porous granulated material having 0.5-15mm average grain diameter and 0.1-1000mum pore diameter is dipped in an aqueous solution prepared by dissolving chitosan in water in an amount of 100-500 times and treated under reduced pressure of <=600mmHg to adsorb the chitosan thereon. The resultant porous granulated material is then dried at 40-110 deg.C for 0.5-8hr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an unfired porous structure having functions such as soil improving action, adsorbing action, antibacterial action, activating physiological function of plant cells, preventing continuous cropping damage and nematicidal action. It is about granules.

[0002]

2. Description of the Related Art Conventional porous granules used as soil conditioners include, for example, those obtained by mixing raw materials mainly composed of diatomaceous earth, shaping them into spherical or columnar shapes, and firing them. Has been.

The granules produced in this manner are used, for example, for lawns as a soil conditioner for floor soil or as soil.

On the other hand, chitosan obtained by hydrolyzing the acetyl group of chitinous substances such as crustaceans is known to have various functions such as promotion of plant growth and prevention of diseases such as large patch. Shigeru Hirano, Development and Application of Chitin and Chitosan, Industrial Technology Society, 1987.

However, chitosan is difficult to dissolve in water,
It has to be diluted with a large amount of water and sprayed, and since the duration of the effect is relatively short, spraying is troublesome.

[0006]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a porous granule which can be easily applied and has a long-lasting effect, which is used as a soil improving material, an adsorbing material, a bactericidal material or the like. To do.

[0007]

Means for Solving the Problems The present inventors have made extensive studies in view of the above problems, and as a result, in a porous granulated product produced mainly from diatomaceous earth, by adsorbing chitosan, the action of chitosan can be obtained. It was found that it can be strengthened and its duration can be extended.

The present invention provides a porous granulated product obtained by adsorbing chitosan.

In the present invention, "adsorption" means any form in which chitosan is present on the surface or inside of the porous granule.

The porous granules used in the present invention are diatomaceous earth,
Examples include chamotte, clay, foamable shale, volcanic ash, activated carbon, vermiculite, zeolite, and the like, which are calcined or non-calcined granules, and these are used alone or in a compounded state. As a preferable material for the porous granulated material, diatomaceous earth can be mentioned.

The content of the above material in the porous granulated product is 60.
% Or more. Other components include plastic clay and the like.

The shape of the porous granule may be any shape, and examples thereof include lumps, granules, rods and flakes.
The size of the granulated product is 0.5 to 15 mm in average diameter.
It is a degree.

The pore size of the porous granulated product is 0.1 to 1
Approximately 000 μm, and the firing is 900 to 1100
It is performed at about 0 ° C. for about 0.5 hours.

As the chitosan to be adsorbed on the porous granulated material, any conventionally known chitosan can be used. Preferred chitosans include microbially treated chitosan.

The chitosan of the present invention is a product obtained by hydrolyzing the N-acetyl group of chitin. Some of the acetyl groups are hydrolyzed and some of the acetyl groups remain without being hydrolyzed. Including. That is, the chitosan of the present invention contains 70% or more, preferably 8% or more of N-acetyl groups.
0% or more is hydrolyzed. The average molecular weight of the chitosan of the present invention is not particularly limited, but it is usually about several thousand to 200,000.

The adsorption of chitosan to the porous granules can be carried out, for example, by impregnating the porous granules with an aqueous chitosan solution and then drying. As the chitosan aqueous solution, a solution obtained by dissolving biochitosan (produced by deacetylating chitin by a microorganism) in 100 to 500 times the amount of water is used. Chitosan may be free, acetic acid, maleic acid, fumaric acid,
It may be a dilute organic acid solution such as citric acid. The impregnation of the porous granules with the chitosan aqueous solution is carried out, for example, by immersion impregnation under normal pressure or reduced pressure impregnation in a vacuum container. The reduced pressure impregnation is carried out by placing the granulated product in a vacuum container and reducing the pressure for 30 minutes, and adding the chitosan aqueous solution into the container while maintaining the reduced pressure. Vacuum impregnation is about 60 mmHg or less, preferably 1
It is performed at about 5 mmHg or less. Then, the solvent is dried. The drying is performed under normal pressure or reduced pressure for about 0.5 to 8 hours at a temperature of about 40 to 110 ° C. The water content of the dried porous granules is about 0 to 10% by weight.

[0017]

EFFECT OF THE INVENTION The porous granulated product of the present invention having chitosan adsorbed therein has chitosan settled in the pores of the granulated product, so that it is compared with a mixture of chitosan and porous granulated product. The action duration of chitosan is long, and the outflow of chitosan due to rainwater etc. can be prevented.

When it is used as a soil conditioner, a plant growth promoter, a bactericidal agent, an agent for activating the physiological function of plant cells, a preventive agent for continuous crop damage, a nematicidal agent, etc., it only has to be sprayed once. The number of times can be reduced, and workability and economy can be improved.

[0019]

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0020]

[Example 1 and Comparative Examples 1 to 3] Properties of the calcined porous granules before adsorption of chitosan are shown in Table 1 below.

..

[Table 1] In addition, "DP" in Table 1 represents a diatomaceous earth fired porous granulated material.

The diatomaceous earth calcined porous granules (DP) shown in Table 1 are about 5 mm in diameter when a commercially available diatomaceous earth-based material (Kuwano Sangyo Co., Ltd.) is extracted and molded.
Granulate to a length of about 10 mm, 900 ° C in a rotary kiln
It was obtained by baking for 20 minutes.

As the chitosan, a commercially available 200-fold diluted solution (trade name: Bio-chitosan; manufactured by Sanin Construction Co., Ltd.) was used.

The chitosan adsorption granulated product of the present invention is obtained by immersing the above-mentioned calcined granulated product in a 200-fold diluted solution of the above-mentioned chitosan,
After impregnating in a vacuum vessel under a reduced pressure of 10 mmHg, 24
It was obtained by drying with warm air at a time of about 60 ° C. The water content of the obtained chitosan adsorption granulation product (KDP) was 2% or less.

The chitosan adsorbed granules obtained were mixed with river sand and upland soil in the proportions shown in Table 2 to observe the growth of lawn (Bentgrass seaside, Takii seedling). In addition, using the soils shown in Comparative Examples 1 to 3 in Table 2, the lawn growth was observed in the same manner. In Comparative Example 3 of Table 2, the soil having the mixing ratio shown in Table 2 was mixed with a commercially available 200-fold diluted solution of chitosan.

[0026]

[Table 2] Soil mix ratio (%) Chitosan Lawn growth composition DP River sand Sand field Soil KDP addition amount test A 40 60 0 × B 20 30 50 0 △ C 20 30 50 50 D Equivalent to ○ D 30 50 20 KDP ◎ The results are shown in Table 2. In Table 2, "A" indicates that the lawn growth was very good.

"O" indicates that the lawn growth was good.

"Δ" indicates that lawn growth is normal.

"X" indicates that the lawn growth was poor.

From the results shown in Table 2, the usefulness of the chitosan adsorption granulation product of the present invention was confirmed.

[0031]

Claims (1)

[Claims] 1. A porous granulated product obtained by adsorbing chitosan in the porous granulated product.