JPH0228692Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an artificial soil for hydroponic cultivation made of a cylindrical body of a transparent water-swellable crosslinked polymer, which has excellent ornamental effects and suitable performance as an artificial soil for hydroponic cultivation of plants. With changes in the living environment in recent years, ornamental plants such as potted plants are being used as decorations to add moisture to living spaces such as apartment complexes, condominiums, coffee shops, restaurants, cafeterias, department stores, and shops. The method of placing them as seeds is widely adopted. Furthermore, in order to enhance the ornamental effect,
Various methods have also been adopted for hydroponically cultivating plants in transparent containers for the same purpose. Conventionally, when cultivating plants hydroponically, plants are grown directly in water containing fertilizer components, or in artificial soil filled with pebbles, gravel, glass pieces, plastic, etc. in water containing dissolved fertilizer components. There are methods to do this. The former method does not adequately retain the roots during hydroponic cultivation, so there are drawbacks such as floating roots, overturning of plants, settling, and poor ventilation. Even if it is possible to retain water, the water retention is not sufficient, and it is not excellent from an aesthetic point of view, so it can hardly be said that it is suitable for ornamental hydroponic cultivation. The present inventors investigated water-swellable cross-linked polymers with excellent ornamental effects as artificial soil for hydroponic cultivation of plants, and found that a specific cylindrical body made of transparent water-swellable cross-linked polymers achieved the above objective. We have discovered that this is the case and have come up with this invention. That is, the present invention consists of a cylindrical body made of a transparent water-swellable crosslinked polymer, the diameter r of the straight cross section of the cylinder is in the range of 2 to 40 mm, and the height l of the cylinder is within the range of the diameter r. This artificial soil for hydroponic cultivation is characterized by having a ratio l/r of 0.3 to 15. The artificial soil for hydroponic cultivation in the present invention is made of a cylindrical body made of a transparent water-swellable cross-linked polymer, and the size of the cylindrical body is such that the diameter r of the circle in the right cross section of the cylindrical body is in the range of 2 to 40 mm, and It is necessary that the height l of the cylinder is in the range of 0.3 to 15 as a ratio l/r to the diameter r, and furthermore, the diameter r of the circle in the right cross section of the cylinder is in the range of 3 to 20 mm, and The ratio l/r of the height l to the diameter r is preferably in the range from 0.5 to 5, in particular from 0.7 to 2. Here, the cylindrical body may be not only a perfect cylindrical body but also a cylindrical body with some distortion. Furthermore, the size of the cylindrical body means the size in a water-swollen state. Even if the diameter of the circle on the right cross section of the cylindrical body of the transparent water-swellable crosslinked polymer is larger than 40 mm or smaller than 2 mm, the ornamental effect will be poor, and the height of the cylindrical body will be less than the diameter. Even if the ratio l/r becomes larger than 15 or smaller than 0.3, the ornamental effect becomes inferior. In the present invention, the water swelling ratio of the cylindrical body of the transparent water-swellable cross-linked polymer is usually 10 to 1000 as a weight ratio of absorbed water to the weight of the water-swellable gel-like cross-linked polymer in a dry state; Preferably it is in the range of 20 to 800. Further, in the present invention, the transparent water-swellable crosslinked polymer constituting the cylindrical body is a water-swelled product of a water-swellable gel-like crosslinked polymer. The water-swellable gel-like crosslinked polymer may be any gel-like crosslinked polymer that becomes transparent upon swelling with water. Specifically, water-swellable gel-like crosslinked polymers consisting of (meth)acrylamides component units, crosslinkable monomer component units, (meth)acrylamides component units, (meth)acrylic acid (salt) component units, Water-swellable gel-like crosslinked polymer consisting of crosslinkable monomer component units, saponified starch/acrylonitrile graft polymer, starch/polyacrylic acid graft copolymer, starch/styrene sulfonic acid graft polymer, starch/vinyl sulfone Examples include acid graft polymers, cellulose/acrylonitrile graft polymers, cellulose/styrene sulfonic acid graft polymers, crosslinked carboxymethyl cellulose polymers, and saponified vinyl acetate/acrylic acid ester copolymers. Among the water-swellable gel-like polymers, water-swellable gel-like crosslinked polymers consisting of the acrylamide component units and crosslinkable monomer component units or (meth)acrylamide component units and (meth)acrylic acid ( A water-swellable gel-like crosslinked polymer comprising a salt) component unit and a crosslinkable monomer component unit is preferred. A water-swellable gel-like crosslinked polymer or a (meth)acrylamide component unit consisting of the above-mentioned suitable acrylamide component unit/crosslinkable monomer component unit.
The (meth)acrylamide component units constituting the water-swellable gel-like crosslinked polymer consisting of (meth)acrylic acid (salt) component units and crosslinkable monomer component units include acrylamide, methacrylamide, or their N- It is an alkyl substituted product, and specific examples thereof include acrylamide, methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N-methylmethacrylamide, N,N-dimethylmethacrylamide, and the like. Specifically, (meth)acrylic acid (salt) component units include acrylic acid, methacrylic acid, lithium acrylate, lithium methacrylate, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, etc. ) alkali metal salts of acrylic acid, alkaline earth metal salts of (meth)acrylic acid such as magnesium acrylate, magnesium methacrylate, calcium acrylate, and calcium methacrylate; (meth)acrylics such as ammonium acrylate and ammonium methacrylate; Examples include ammonium salts of acids. Further, specific examples of the crosslinkable monomer component unit include N,N'-methylenebis(meth)acrylamide, N,N'-ethylenebis(meth)acrylamide, N,N'-propylenebis(meth)acrylamide, N,N'-hexamethylenebis(meth)acrylamide, N,
Bis(meth)acrylamides such as N'-phenylene bis(meth)acrylamide, ethylene bis(meth)acrylate, propylene bis(meth)acrylate, hexamethylene bis(meth)acrylate
Bis(meth)acrylates such as acrylate, diethylene glycol bis(meth)acrylate, triethylene glycol bis(meth)acrylate, polyethylene glycol bis(meth)acrylate
Examples include acrylate, and a mixture of two or more components is also acceptable. The composition of the components constituting the water-swellable gel-like crosslinked polymer is as follows: the (meth)acrylamide component unit a
is usually in the range of 40 to 100 mol%, preferably 60 to 100 mol%, and the (meth)acrylic acid (salt) component unit b is usually 0 to 60 mol%,
It is preferably in the range of 0 to 40 mol%, and the crosslinkable monomer component unit c is usually 0.05 to 5 mol, preferably 0.5 to 3 mol, per 100 mol of component a or the total of components a and b. It is in the molar range. Further, the density of the water-swellable gel-like crosslinked polymer in a dry condition (density after drying at 60°C for 48 hours) is usually 1.1 to 1.8 g/cm ³ , preferably
It is in the range of 1.2 to 1.6 g/cm ³ . The density and swelling degree of the dried water-swellable gel-like crosslinked polymer were measured by the following method. (1) Density: A fixed weight Wg of the dried polymer was collected into a 25 ml pycnometer. The pycnometer containing the polymer was then placed in a constant temperature bath at 24°C and filled with toluene at 24°C. The toluene volume V was determined from the weight of toluene required for this, and calculated using the following formula. Polymer density (g/cm ³ ) = W/25-V (2) Swelling degree: Collect a certain weight W ₁ g of dried polymer and immerse it in water for 24 hours at 24 degrees to sufficiently swell the polymer. I let it happen. Thereafter, excess water was removed, and the weight W ₂ g of the swellable gel was measured and calculated using the following formula. Swelling degree 24℃ = W ₂ - W ₁ /W ₁ The transparent water-swellable cross-linked polymer of the present invention has anti-algae properties,
In order to impart antifungal or coloring properties, algaecides,
Antifungal agents or coloring agents can also be added,
During the production of the water-swellable gel polymer, algae-proofing unsaturated monomer component units such as vinyl bond-containing triazine derivatives and vinyl bond-containing tin compounds, mold-proofing unsaturated monomer component units, and coloring non-containing monomer units are used. It is also possible to copolymerize saturated monomer component units, or to impart the above functions by reacting the water-swellable gel-like polymer with an anti-algae component, an anti-mold component, or a coloring component. It is. Further, the transparent water-swellable crosslinked polymer of the present invention may be impregnated with fertilizer components, plant hormones, and growth promoters. When the cylindrical body of the transparent water-swellable cross-linked polymer of the present invention is used in artificial soil for hydroponic cultivation of ornamental plants such as flowers, plants, and ornamental plants, it can be used for ornamental purposes such as interior decoration and store decoration. It is suitable for use as it is highly effective, especially for glass, polystyrene,
It is preferable to use transparent containers such as flower pots, pots, and wine glasses made of transparent materials such as polymethyl methacrylate because of their excellent effects. Furthermore, the transparent container is filled with artificial soil for hydroponic cultivation consisting of a cylindrical body of the transparent water-swellable crosslinked polymer of the present invention, the ornamental plants are planted in this, and the transparent container is placed on a light illumination stand. When placed on top of a transparent water-swellable crosslinked polymer and irradiated with light from the bottom, the reflections on each side surface and each cross-section of the transparent water-swellable crosslinked polymer look beautiful, giving an especially excellent ornamental effect. In the artificial soil for hydroponic cultivation filled with the cylindrical bodies of the transparent water-swellable cross-linked polymer of the present invention, seeds of the above-mentioned ornamental plants can be sown, seedlings can be transplanted, and seedlings can be grown. You can also transplant the plants. The artificial soil for hydroponic cultivation of the present invention is made of cylindrical bodies made of transparent water-swellable cross-linked polymers, so it has more gaps than spherical or other shaped soils, which allows for good air circulation and allows plants to grow. There is no root rot, and since there is a high degree of inter-particle catching, the layer is less likely to disintegrate, resulting in excellent plant posture stability, and its high light reflectivity provides a high decorative effect using reflected light. The artificial soil for hydroponic cultivation made of the cylindrical body of the transparent water-swellable crosslinked polymer of the present invention has transparency,
It has excellent air retention, water retention, and root retention, making it suitable for ornamental cultivation.Also, since root development can be observed, it is suitable for experimental observation cultivation or observation cultivation for learning and research purposes. There is. Next, the present invention will be specifically explained using examples. Reference Example 1 9.79g of acrylamide and 0.21g of N,N'-methylenebisacrylamide were dissolved in 90g of water. After the monomer was completely dissolved, 0.01 g of ammonium persulfate was added and dissolved. The obtained homogeneous solution was poured into a mold having many cylindrical depressions with a diameter of 4 mm and a depth of 5 mm, and a reaction was carried out at 80° C. for 1 hour. The transparent water-swellable crosslinked polymer produced in this reaction was taken out and washed with running water to remove the monomer components remaining in the granules. Particulate matter after washing
Dry in a hot air dryer at 60-80°C. The density (24°C) of the obtained polymer was 1.276 (g/cm ³ ),
When immersed in water at 24°C, a cylindrical body (diameter 7 mm, length 7.5 mm) of transparent water-swellable crosslinked polymer was obtained.
The swelling degree of this product was 29. Reference Example 2 An aqueous solution containing the acrylamide component unit a, crosslinkable monomer component b, and radical initiator used in Reference Example 1 was heated to 80°C and placed in a cylindrical polymerization vessel with an inner diameter of 4 mm so that the residence time was 5 minutes. was continuously supplied.
The obtained cylindrical water-swollen product with a diameter of 4 mm was continuously cut into a length of 4 mm. The obtained water-swollen product was post-treated according to Reference Example 1 to obtain granules with uniform particle size. The density of this granule (at 24°C) is 1.291 (g/
cm ³ ), and by immersing it in water at 24°C, a cylindrical body (diameter 7
mm, length 7 mm) was prepared. The degree of swelling of this material is
It was 31. In addition, the inner diameter of the cylindrical polymerization vessel was varied from 1 to 10 mm, and the cylindrical water-swollen material with a diameter of 1 to 10 mm was prepared with a length of 1 to 10 mm.
Uniform granules of various particle sizes were obtained by cutting at 30 mm. By similarly immersing this granular material in water, cylindrical bodies of transparent water-swellable crosslinked polymers of various sizes were prepared. Reference example 3 200ml in a 500ml four-neck separable flask equipped with a stirring bar, thermometer, condenser and nitrogen blowing tube
of toluene, followed by 85 g of 9.79 g acrylamide, 0.21 g N,N'-methylenebisacrylamide and 0.045 g gelatin (dispersant).
Dissolve in water and charge. The inside of the system is at room temperature (25℃),
While stirring at 100 rpm, the aqueous layer and toluene layer are replaced with nitrogen at a flow rate of 200 ml/min for 15 minutes. continue
Add 0.01 g of ammonium persulfate dissolved in 5 g of water, and purify with nitrogen for another 5 minutes. After that, the nitrogen blowing tube was removed, and the system was sealed with nitrogen, and the stirring speed was set to 700 rpm (3 blades including an anchor type blade, linear velocity at a distance of approximately 4.5 cm from the center).
After adjusting the temperature to 10,000 cm/min), the contents were heated to 80°C at a rate of 1.5°C/min using an oil bath for polymerization. The reaction was continued at 80° C. for 15 minutes while stirring at 700 rpm, and further for 60 minutes while stirring at 400 rpm, to complete the polymerization. The resulting spherical (and partially bead-shaped) water-swollen gel-like crosslinked polymer is cooled to room temperature, then filtered to separate it from the toluene layer, followed by steam stripping, and then washed under running water. Toluene, gelatin, and monomer components remaining in the granules were removed by washing with . After washing, the water-swelled gel-like crosslinked polymer was dried in a hot air dryer at 60 to 80°C. The density (24℃) of the obtained polymer was 1.260 (g/
cm ³ ), and when immersed in water at 24°C, it becomes transparent and 3 cm 3 ).
A water-swellable cross-linked polymer containing spherical or partially bead-like shapes of ~6 mm was obtained. The degree of swelling of this product was 20. Examples 1 to 2 (Meth)acrylamide component unit/crosslinkable monomer component unit, or (meth)acrylamide component unit/(meth)acrylic acid derivative component unit/crosslinkable monomer component with the composition shown in Table 1 Fertilizer and algae-preventing agent are prepared by soaking pellets of a cross-linked copolymer consisting of units in water containing diluted liquid fertilizer (Hawkland's solution) and algae-prevention agent (manufactured by Kumiai Chemical Industry Co., Ltd.; trade name: Tormo). A cylindrical object (diameter 7 mm, length 7 mm) of a transparent water-swellable crosslinked polymer was obtained.
Artificial soil for hydroponic cultivation was prepared by filling three transparent glass containers with the cylindrical bodies of the transparent water-swellable crosslinked polymer. 7 cm of grove begonia "Margaret decora" was transplanted into the container filled with the artificial soil for hydroponic cultivation, placed in bright semi-shade, and cultivated for ornamental purposes while supplemented with a dilute solution of liquid fertilizer. The begonias grown in this artificial soil are growing smoothly, with good root growth, and one month after transplanting, new roots can be observed through the transparent container, and the growth of stems, leaves, and roots has been good since then. It was hot. Furthermore, the growth status of stems and leaves is shown in Table 1.

【table】

[Table] Examples 3 to 7 With the composition shown in Table 2, begonia,
Seedlings of Saintpaulia and pineapple, approximately 10 cm in length, were transplanted, placed in a room with sunlight, and cultivated for ornamental purposes while supplemented with a dilute solution of liquid fertilizer. The plants grown in this artificial soil continued to grow smoothly even after 6 months, and in particular, the growth conditions of Begonia and Saintpaulia were the same as those in Examples 1 and 2, and good growth conditions were observed. The growth status is shown in Table 2.

[Table] When the containers of Examples 1 to 7 above are placed on the top of a light illumination stand and light is irradiated from the bottom, each side, each cross section, and The air bubbles between the artificial soil and the reflections on the roots of the plants look beautiful, so it has a particularly excellent ornamental effect. Example 8 A cylindrical body of a transparent water-swellable gel polymer as shown in Table 3 was obtained according to Example 1 using crosslinked copolymer granules having different particle sizes and lengths. A transparent wine glass was filled with the cylindrical body of the transparent water-swellable crosslinked polymer to obtain artificial soil for hydroponic cultivation, and plants were planted in this in the same manner as in Example 1. In either case, as in Example 1, the ornamental effects were excellent, the growth conditions were good, and it was also suitable for observation of root growth conditions.

[Table] Comparative Examples 1 to 4 According to Example 1, cylindrical bodies of transparent water-swellable crosslinked polymers as shown in Table 4 were obtained. Artificial soil for hydroponic cultivation was prepared by filling a transparent glass container with the cylindrical body of the transparent water-swellable crosslinked polymer. Various plants were transplanted into the container according to Example 1,
Cultivated for ornamental purposes. The artificial soils for hydroponic cultivation shown in Comparative Examples 1 and 2 had the same transparency and water retention as those shown in Examples 1 to 7, but were inferior in air retention and root retention, and did not support seedlings. It was not sufficient for transplant cultivation. In addition, the cylindrical body of the transparent water-swellable crosslinked polymer is inferior in terms of light reflection on each side surface and each cross section,
In addition, since the air bubbles are not sufficiently captured between the artificial soils, there is no reflection from the air bubbles, and therefore the ornamental effect is not sufficient. On the other hand, Comparative Example 3 and Comparative Example 4
Regarding the transparent water-swellable crosslinked polymer shown in Example 1, the transparency and water retention properties were the same as those shown in Examples 1 to 7, but the uniform dispersion of roots during plant transplantation and propagation was poor, and water retention was also poor. Since the swollen crosslinked polymer itself was large, the ornamental effect was inferior to that of the polymers shown in Examples 1 to 7 in terms of imbalance.

[Table] Comparative Examples 5 to 7 As Comparative Example 5, the spherical transparent water-swellable crosslinked polymer obtained in Reference Example 3, and as Comparative Examples 6 and 7, a commercially available amorphous water-absorbing polymer (manufactured by Nippon Gosei Kagaku Co., Ltd.; trade name Mizumochi No. 1) was immersed in the same water as used in Example 1 to obtain spherical and amorphous water-swollen polymers as shown in Table 5. The amorphous water-swellable polymers of Comparative Examples 6 and 7 were
5 compared to those of Examples 1 to 7 and Comparative Examples 1 to 5.
They exhibited a swelling degree as high as ~6 times, but all were transparent water-swellable polymers. An artificial soil for hydroponic cultivation was prepared by filling a transparent glass container with the transparent water-swellable polymer. Approximately 5 to 7 of various plants were placed in the container according to Example 1.
Seedlings with a height of cm were transplanted and cultivated for ornamental purposes. As a result, the artificial soil for hydroponic cultivation shown in Comparative Example 5 had no particular problems in terms of transparency and water retention, but was poor in air retention and root retention.
In other words, in terms of air retention, when using this artificial soil, 40% of transplanted seedlings had discolored roots or leaves 20 to 50 days after transplanting, and the other 60% had discolored roots or leaves one month after transplanting. Two months later, the stem height was approximately 7 cm, and the maximum length of the leaves was approximately 5 cm, and almost no growth was observed from the time of transplantation. In addition, when monocotyledonous plants such as table palm or Dracaena conquina tricolor are transplanted into the artificial soil,
The plants themselves were inferior to Examples 1 to 7 in terms of ornamental effects, such as settling and rolling over. The transparent water-swellable polymers shown in Comparative Examples 5 and 6 had non-uniform shapes, so they did not have uniform air retention properties throughout the soil, and some areas were rooted. Furthermore, since the degree of light reflection inside the soil could not be stably obtained, the soil was inferior in terms of ornamental effect compared to Examples 1 to 7.

[Table] Next, a plant posture stability test was conducted on the artificial soils of Examples 1 to 8 and Comparative Examples 1 to 7. The test method is to fill a 500 ml beaker (diameter 9 cm) with a specified amount (X mm height) of the artificial soil to be tested, and add a freshly sharpened pencil (for pencil tack test) to the beaker (diameter 9 cm).
4B, height 17.5 cm, weight 4.8 ± 0.05 g) was inserted into the center of the beaker at an angle of 70° so that the tip reached the bottom. At this time, the minimum amount X of the test artificial soil required to prevent this pencil from tipping over was compared. The results are shown in Table 6.

[Table] From the results in Table 6, Comparative Examples 1, 2, and 5 have a 1.2
~2.6 times the amount of soil was required. This showed that the artificial soil was slippery between soils and was inferior in stability as soil compared to Examples 1 to 8 and Comparative Examples 3, 4, 6, and 7.

[Brief explanation of drawings]

FIG. 1 shows a perspective view of a cylindrical body of the transparent water-swellable cross-linked polymer of the present invention, and FIG. 2 shows a drawing of a wine glass filled with the cylindrical body in which pineapple is grafted.

Claims (1)

[Scope of utility model registration request] Consisting of a cylindrical body of transparent water-swellable crosslinked polymer,
A hydroponic system characterized in that the diameter r of the circle in the right cross section of the cylinder is in the range of 2 to 40 mm, and the height l of the cylinder is in the range of 0.3 to 15 as a ratio l/r to the diameter r. Artificial soil for cultivation.