JPH1042712A - Pot for raising seedling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seedling-raising pot comprising a biodegradable resin and a filler, having many specific holes in the bottom, capable of preventing the deterioration in the strength of the pot, enabling to transplant the seedling together with the seedling-raising pot, and large in the biodegradation speed of the seedling-raising pot. SOLUTION: This pot for raising a seedling comprises 100 pts.wt. of a biodegradable resin such as poly 3-hydroxybutyric acid, 3-hydroxybutyric acid-3- hydroxyvaleric acid copolymer or a polylactic acid ester and 10-150 pts.wt. of a filler, such as calcium carbonate or glass balloons, preferably having an average particle diameter of 0.1-100μm. The pot has many holes each having a hole diameter of 0.2-100mm<2> , preferably 3-70mm<2> , and has a bottom part porosity of 30-90%, preferably 50-90%. The seedling can extend its roots into soil through the holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seedling raising pot useful for growing seedlings such as vegetables, flowers and ornamental plants.

[0002]

2. Description of the Related Art Conventionally, vegetables such as eggplant, cucumber, lettuce, melon, strawberry, tomato, morning glory, kyoto,
Nursery pots for agricultural and horticultural purposes, such as flowering plants such as salvia and calendula, and ornamental plants such as dracaena and monstera, have been produced from non-biodegradable resins such as vinyl chloride or polyethylene. Since these seedling pots are not biodegradable, they have to be taken out of the seedling pot together with the soil when transplanting the seedlings, which requires a lot of time and labor. Therefore, in recent years, in order to solve this problem, a method of obtaining a seedling pot with a biodegradable resin has been studied.

[0003]

However, the decomposition rate of biodegradable resin in soil is slow. For example, see Biodegradable Plastics Study Group: Biodegradable Plastic Handbook (1
According to 955), it takes about 3 to 6 months for polylactic acid to undergo any decomposition, and about 12 months for metabolism (conversion to other substances) (p. 567).
In a biodegradability test in the soil of a shampoo bottle obtained from polyethylene succinate, which is a kind of aliphatic polyester, it was stated that shape destruction was observed about 4 months after the start of the test (p. 590). I have. Furthermore, it is described that all of the biocellulose disappears three months after the soil is buried (p. 374), but this material cannot be used alone because of its poor water resistance. As described above, it is known that the use of a biodegradable resin alone adversely affects the growth of seedlings after transplantation due to a low decomposition rate in soil.

Accordingly, an object of the present invention is to provide an inexpensive seedling raising pot capable of improving the decomposition rate in soil and preventing growth inhibition of the seedling after transplantation.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the improvement of the decomposition rate of biodegradable resin in soil and the structure of the seedling raising pot itself. , That a composition combining a biodegradable resin and a filler is suitable, that a large number of holes are formed only in the bottom portion of the seedling raising pot to prevent the strength of the seedling raising pot from being reduced, The present invention has been found out that an optimum state without entanglement and the like can be obtained because the base material extends sufficiently into the soil through the holes.

That is, the seedling raising pot of the present invention comprises 100 parts by weight of a biodegradable resin and 10 to 150 parts by weight of a filler,
The bottom, the cross-sectional area of a single hole in 0.2～100Mm ^2, is 30% to 90% porosity in the bottom, but has a number of holes, and the thickness of the entire wall in 0.5~5mm It is preferred that there be.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. As the biodegradable resin used in the present invention, for example, poly-3-hydroxybutyric acid, 3-hydroxybutyric acid-
3-hydroxyvaleric acid copolymer, 3-hydroxy-4-
Aliphatic polyesters derived from so-called biosynthesis such as hydroxybutyric acid copolymer and derivatives thereof; aliphatic polyesters such as poly (ε-caprolactone), polyethylene succinate, polybutylene succinate, polylactic acid ester, polyamino acids, and polyvinyl Resins derived from chemical synthesis such as alcohols and derivatives thereof; copolymers of a thermoplastic resin and a biodegradable aliphatic polyester, or a mixture of the above-described aliphatic polyester and a general resin; It is used in combination of two or more species. Of these, preferred are aliphatic polyesters derived from microorganisms and those derived from chemical synthesis, which are excellent in biodegradability.

The filler includes an inorganic filler and an organic filler. Examples of the inorganic filler include carbon black, calcium carbonate, clay, talc, aluminum hydroxide, magnesium hydroxide, silica, ceramic balloon, glass powder, Examples thereof include glass balloons, glass beads, quartz, mica, titanium oxide, iron oxide, and magnesium oxide. Of these, calcium carbonate and glass balloons are preferable in terms of cost and moldability. Examples of the organic filler include starches and derivatives thereof obtained from grains such as rice, wheat and corn, potatoes such as potatoes, sweet potatoes and tapioca; cellulose and derivatives thereof; chitin, chitosan and derivatives thereof, and wood flour. Among them, starch is preferred from the viewpoint of cost and moldability. The above-mentioned inorganic or organic fillers are used as one kind or as a mixture of two or more kinds with respect to each or both of them.
Those having a range of 100 μm are preferred.

These fillers may be used, if necessary, in order to improve the affinity with the biodegradable resin and the dispersibility of the filler particles per se, for example, a silane coupling agent, a titanate-based coupling agent, and aluminum. Using a surface modification agent such as a nate-based coupling agent, various surfactants, etc., a dry method,
The surface may be modified by a wet method (method by hydrolysis) or an integral blend method (on a mixing roll).

[0010] When using these treating agents,
It is preferable to select in consideration of compatibility with the filler and the biodegradable resin. For example, among inorganic fillers, a silane coupling agent is preferable for ceramic balloons, glass balloons, glass beads, silica or quartz whose main component is silicon dioxide, and 3-hydroxybutyric acid-3 is used as a biodegradable resin. -Hydroxyvaleric acid copolymer, poly (ε
-Caprolactone), an aliphatic polyester such as polyethylene succinate or polylactic acid ester, a silane coupling agent having an epoxy group or an amino group in the molecule, for example, β- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane or MAC
It is effective to use a polymer type such as 2101 (trade name, manufactured by Nippon Unicar).

In general, a silane coupling agent has a reactive group that interacts with an inorganic substance and a reactive group that interacts with an organic substance in a molecule. When treated with the agent,
A silane coupling agent is chemically bonded to the surface of the inorganic filler,
Bonds by suction such as hydrogen bonding or physical adsorption. The other reactive group of the silane coupling agent, which interacts with an organic substance, changes the surface energy of the inorganic filler by covering the surface of the inorganic filler, or forms a chemical bond with the biodegradable resin. Therefore, by treating the above inorganic filler with a silane coupling agent, the affinity at the interface between the surface of the inorganic filler and the biodegradable resin is improved. Physical properties can be further improved.

For inorganic fillers such as calcium carbonate, titanium oxide or magnesium oxide, titanate-based coupling agents are effective, especially titanates having a solubility parameter value close to the solubility parameter value of these inorganic fillers. It is preferred to select a system coupling agent.

The titanate-based coupling agent has a reactive group that interacts with an inorganic substance and a group that interacts with an organic substance in the molecule. When an inorganic filler such as calcium carbonate, titanium oxide or magnesium oxide is treated with a titanate-based coupling agent, it reacts with bound water on the surface of the inorganic filler, and the titanate-based coupling agent becomes a single molecule on the surface of the inorganic filler. The group which forms a layer and interacts with the other organic substance interacts with the biodegradable resin constituting the matrix. Therefore, the inorganic filler is uniformly dispersed in the biodegradable resin, the adhesion between the inorganic filler surface and the biodegradable resin interface is enhanced, and the reinforcing effect is effectively exhibited (by Fumio Ide: High). Molecular surface modification, 1987, 24
3).

Acetoxyaluminum diisopropylate, which is an aluminum-based coupling agent, is effective when carbon black is used as the inorganic filler.

On the other hand, 2,4,7,9-tetramethyl-5-decyne-4,7,4,7,9-tetramethyl-5-decyne-4,7 are used as surface modifiers such as starch, cellulose and derivatives thereof, chitin, chitosan and derivatives thereof, and wood flour. Diols (A), ethylene oxide adducts of (A) or acetylene glycols such as 3,6-dimethyl-4-octyne-3,6-diol; 3,5-dimethyl-1-hexyn-3-ol and the like Acetylene alcohol; (A) and 2-ethylhexylhexanol, (A) and ethylene glycol or (A) and blended product of polyoxyethylene alkylphenyl ether and ethylene glycol; various surface activities such as glycerin fatty acid ester and polyglycerin fatty acid ester Agents are preferred.

The hydrophilic group portion of these surfactants interacts with the surface of the organic filler particles by suction force such as hydrogen bonding or physical adsorption, and the hydrophobic group portion of the surfactant becomes biodegradable. Interacts with resin. The addition amount of this surfactant in the range of 0.5 to 5 PHR is sufficient. This is
If it is less than 0.5 PHR, the effect as a surface treatment agent cannot be expected so much, and if it exceeds 5 PHR, it becomes expensive and economical.

In the seedling raising pot of the present invention, 10 to 150 parts by weight of a filler is added to 100 parts by weight of the biodegradable resin described above.
Preferably, it is added in a proportion within the range of 50 to 120 parts by weight. When the amount of the filler is less than 10 parts by weight, there is almost no difference between the biodegradable resin to which the filler is not added and the decomposition rate.
If the filler is added in an amount of more than 150 parts by weight, the resulting nursery pot will have reduced mechanical strength and will be difficult to mold. If necessary, a colorant, a plasticizer such as dioctyl phthalate, a fungicide, and the like may be added to the biodegradable resin. A biodegradable resin generally generates about half the heat generation of polyethylene and the like, but a biodegradable resin to which a surface-treated filler is added further reduces the heat generation (1/3 to 1/4). ), There is no problem in incineration treatment in the incinerator.

As shown in FIGS. 1 and 2, the appearance and shape of the seedling raising pot may be any of a cylinder, a truncated cone, a truncated cone, a truncated pyramid, a cone, a pyramid, and the like. In the bottom of the pot body 1, a large number of holes 2
Or a molded article with a grid-like mesh 3 is provided. The average thickness of the whole is 0.5-5mm,
Preferably 1.0 to 3.0 mm, it is preferable hole 2 or lattice-like mesh 3 which are uniformly dispersed at the bottom, that one area 0.2～100Mm ^2, preferably. 3 to 70 mm ^2, the bottom The porosity is 30-90%, preferably 50-90%.

If the total average thickness is less than 0.5 mm, the seedling pot may be damaged during the transplanting operation. If it exceeds 5 mm, the cost increases and molding becomes difficult. If the area of one hole or mesh at the bottom is less than 0.2 mm ^2, it is difficult to form the hole and the roots of the seedlings are difficult to grow sufficiently in the soil through the hole, and the area of one hole or mesh is small. Is 100mm ²
If it exceeds, the soil will spill out of the hole. Further, if the porosity is less than 30%, the number of escape routes for the roots of the seedlings to grow sufficiently is insufficient, and if it exceeds 90%, it is difficult to form a seedling pot. Here, the porosity is a ratio of the total area of holes or meshes to the area of the bottom of the seedling raising pot.

For the production of seedling pots, biodegradable resin 100
Parts by weight and a filler of 10 to 150 parts by weight, and if necessary, a predetermined amount of the above surface modifier, surfactant, coloring agent, plasticizer, fungicide, etc. Is molded into a sheet by T-die extrusion molding or calendar molding, and then a pot is molded by vacuum molding or press molding. Next, a hole is formed in the bottom of the pot with a punch or a needle, etc., to form a seedling raising pot.After forming the side portion of the pot body from a sheet-like material into a cylindrical shape, a mesh-like sheet or molded product is formed on the bottom. There is a method of bonding to form a seedling raising pot, a method of extruding and cutting a cylindrical thin tube, and bonding a mesh-like sheet or molded product to the bottom portion to form a seedling raising pot as described above.

[0021]

EXAMPLES The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to the description of the examples. Example 1 Aliphatic polyester resin: Bionole 3010 (manufactured by Showa Polymer Co., trade name, copolymer of 1,4-butanediol and succinic acid and / or adipic acid) 100 parts by weight, average particle size 2 μm
m 2, 120 parts by weight of calcium carbonate powder, 4 parts by weight of stearic acid and calcium alkyl benzene sulfonate: 77
64 (manufactured by Akishima Chemical Industry Co., Ltd.) 3 parts by weight, 90 ℃
And the mixture was melted and kneaded with a mixing roll heated to a temperature. Kneading was performed until 5 minutes after the resin was melted. The kneaded material is taken out in the form of a sheet, cooled to room temperature, pulverized, and then
After drying for a period of time, a pellet-shaped molded product was produced. This is T-
It is supplied to a general-purpose single-screw extruder (cylinder temperature: 80 to 130 ° C) equipped with a die (die temperature: 130 ° C) to produce a sheet-like molded product having an average thickness of 2 mm, then cut into 30 cm squares, and vacuumed. A cylindrical pot having a diameter of 5 cm on the top and bottom surfaces and a height of 6 cm was formed by molding. Next, a hole with a diameter of 5 mm (area: 19.6 m
m ² ) was opened so that the porosity became 54%, and a seedling-growing pot of the present invention having the shape shown in FIG. 1 was produced.

The resulting nursery pot had sufficient strength and shape to withstand use. 100 in this seedling pot
The soil sterilized by heat at 1 ° C. for 1 hour was packed, and strawberry seedlings having a height of 8 cm were planted. Next, when the strawberry seedlings reached a height of 10 cm, the seedling raising pot was completely buried in the soil, and transplanted together with the seedling raising pot. Three months after transplantation, the decomposition state of the seedling pot and the growth state of the strawberry seedling were examined. As a result, the decomposition state of the seedling pot was different between the side part and the bottom part, and progressed only partially in the side part. However, it was observed that the bottom part was sufficiently decomposed, but the appearance remained. In addition, the stalks and roots of the strawberry seedlings both grew well, and especially the roots extended into the soil through the holes in the pot.
This test was performed in a constant temperature and humidity room at a temperature of 25 ° C. and a relative humidity of 55% RH under lighting conditions of 12 hours / day.

Example 2 Aliphatic polyester resin: Biopol D600P (trade name, manufactured by Zeneca Corporation, copolymer of 3-hydroxyvaleric acid and 3-hydroxybutyric acid, 3-hydroxyvaleric acid content: 12%) 100 100 parts by weight of corn starch having an average particle size of 15 μm: corn flour (trade name, manufactured by Nippon Flour Milling Co., Ltd.) was kneaded on a mixing roll heated to 150 ° C. until about 5 minutes after melting of the resin. Next, the kneaded product was taken out in the form of a sheet, cooled to room temperature, pulverized, and dried at 75 ° C. for 4 hours to obtain a pellet-shaped molded product. This is a round die (die temperature:
(Cylinder temperature: 130-170 ° C) with a thickness of 1mm and an inner diameter of 5cm
After obtaining a cylindrical molded product of the above, it was cut to a height of 6 cm.

On the other hand, the above-mentioned pellet-shaped molded product is supplied to a general-purpose single-screw extruder equipped with a net extrusion die, and the fusion method (2)
A number of small-diameter nozzles are provided in a ring shape on each of the inner ring and the outer die in a heavy annular shape.The inner and outer dies are rotated in opposite directions to form a thread-like molded product, which is fused in a lattice shape to form a mesh. According to the method for obtaining a shaped article), a shaped article provided with a grid-like mesh having one hole area of 12 mm ² , a porosity of 85%, and an average mesh thickness of 1 mm was formed. This was adhered so as to cover the bottom portion of the cylindrical molded product so as to cover the bottom portion, thereby producing a seedling-growing pot of the present invention having the shape shown in FIG.

The resulting nursery pot had sufficient strength and shape to withstand use. 100 in this seedling pot
The soil sterilized by heat at 1 ° C. for 1 hour was packed, and strawberry seedlings having a height of 8 cm were planted. Next, when the height of the strawberry seedlings became 10 cm, the seedling pot was completely buried in the soil, and transplanted together with the seedling pot. Three months after transplantation, the decomposition state of the seedling pot and the growth state of the strawberry seedling were examined. As a result, the decomposition state of the seedling pot was different between the side part and the bottom part, and progressed only partially in the side part. However, the bottom portion was sufficiently decomposed and the outer shape was hardly recognized. The growth condition of both the stem and root of the strawberry seedling was good. This test was performed under the same conditions as in Example 1.

Example 3 Aliphatic polyester resin: PLACEEL (trade name, poly (ε-caprolactone), manufactured by Daicel Chemical Industries, Ltd.) 100 parts by weight of a glass balloon having an average particle size of 50 μm: X-39 (manufactured by Tokai Kogyo Co., Ltd.) And 50 parts by weight (trade name), and kneaded with a mixing roll heated to 75 ° C. until about 5 minutes after the resin was melted.
This was taken out in the form of a sheet, cooled to room temperature, pulverized, and dried at 75 ° C. for 4 hours to obtain a pellet-shaped molded product. This is supplied to a general-purpose single-screw extruder (cylinder temperature: 70 to 100 ° C.) equipped with a T-die (die temperature: 100 ° C.) to obtain a sheet-like molded product having an average thickness of 3 mm. The shaped article is cut into 30 cm squares, and pressed to
A cylindrical pot having a top and bottom diameter of 5 cm and a height of 6 cm was prepared. A 3 mm diameter (1 mm)
The porosity is 70% due to the needle-shaped object with the area of each hole of about 7 mm ² ).
%, And a nursery pot of the present invention having the shape shown in FIG. 1 was prepared.

The obtained seedling-raising pot was of sufficient strength and shape to withstand use. 100 in this seedling pot
The soil sterilized by heat at 1 ° C. for 1 hour was packed, and strawberry seedlings having a height of 8 cm were planted. Next, when the strawberry seedlings reached a height of 10 cm, the nursery pot was completely buried in the soil, and transplanted together with the nursery pot. Three months after transplantation, the decomposition state of the seedling pot and the growth state of the strawberry seedling were examined. As a result, the decomposition state of the seedling pot was different between the side part and the bottom part, and progressed only partially in the side part. However, although the decomposition had sufficiently progressed at the bottom, it was observed that the outer shape remained. In addition, the stalks and roots of the strawberry seedlings both grew well, and especially the roots grew sufficiently into the soil through the holes in the pot. This test was performed under the same conditions as in Example 1.

Comparative Example 1 Aliphatic polyester resin: Bionole 3010 (supra) 100
Parts by weight, 200 parts by weight of talc, 4 parts by weight of stearic acid and 3 parts by weight of calcium alkylbenzenesulfonate: 7764 (described above) were added, and the mixture was melted and kneaded with a mixing roll heated to 90 ° C. Kneading was performed until 5 minutes after the resin was melted. The kneaded product was taken out in the form of a sheet, cooled to room temperature, pulverized, and dried at 75 ° C. for 4 hours to produce a pellet-shaped molded product. This was placed in a T-die (die temperature: 130
℃) attached general-purpose single screw extruder (cylinder temperature: 80
To 130 ° C.), and an attempt was made to form a sheet-like molded product, but the melt viscosity was high and molding was not possible.

Comparative Example 2 Aliphatic polyester resin: Bionole 3010 (supra) 100
5 parts by weight of calcium carbonate, 1.5 parts by weight of stearic acid
Parts by weight and calcium alkylbenzenesulfonate:
1 part by weight of 7764 (described above) was added, and the mixture was melted and kneaded with a mixing roll heated to 95 ° C. Kneading was performed until 5 minutes after the resin was melted. The kneaded product was taken out in the form of a sheet, cooled to room temperature, pulverized, and dried at 75 ° C. for 4 hours to produce a pellet-shaped molded product. This is supplied to a general-purpose single-screw extruder (cylinder temperature: 90 to 120 ° C) equipped with a T-die (die temperature: 120 ° C), formed into a sheet-like molded product, cut into 30 cm squares, and press-molded. As a result, a cylindrical pot having a top surface and a bottom surface of 5 cm in diameter and a height of 6 cm was produced. Holes are drilled in the bottom of this pot with a punch with a diameter of 10 mm (the area of one hole is about 78.5 mm ² ) so that the porosity is 80%, and a seedling pot having the shape shown in FIG. 1 is produced. did.

The obtained seedling raising pot was sufficiently strong in both strength and shape for use. 100 in this seedling pot
The soil sterilized by heat at 1 ° C. for 1 hour was packed, and strawberry seedlings having a height of 8 cm were planted. Next, when the height of the strawberry seedlings became 10 cm, the seedling pot was completely buried in the soil, and transplanted together with the seedling pot. Three months after transplantation, as a result of examining the decomposition state of the nursery pot and the growth state of the stalks and roots of the strawberry seedling, the stalks and roots of the strawberry seedling showed growth equivalent to those in Examples 1 to 3. Decomposition of the seedling pot was hardly observed. This test was performed under the same conditions as in Example 1.

Comparative Example 3 A hole was formed in the bottom of the pot obtained in Example 1 with a punch having a diameter of 5 mm so that the porosity became 10%, and a seedling raising pot having the shape shown in FIG. 1 was produced. The resulting nursery pots were of sufficient strength and shape to withstand use. Fill the seedling pot with heat-sterilized soil at 100 ° C for 1 hour.
Strawberry seedlings having a height of 8 cm were planted and transplanted in the same manner as in Example 1. Three months after transplanting, the state of decomposition of the seedling pot,
When the height of the strawberry seedlings reached 10 cm, the growth status of the strawberry seedlings was examined.As a result, the decomposition of the seedling pot was only partially advanced on both the side and bottom parts, and the outer shape remained clear. Was. The growth condition of the stem of the strawberry seedling was considerably inferior to Examples 1-3. Also, the roots grew through the gaps in the holes, but the growth state was considerably inferior to Examples 1-3. This test was performed under the same conditions as in Example 1.

COMPARATIVE EXAMPLE 4 A hole having a porosity exceeding 90% was made in the bottom of the pot obtained in Example 1 with a punch having a diameter of 5 mm, but the hole could not be produced.

Comparative Example 5 The production of a seedling raising pot was attempted by making a hole in the bottom of the pot obtained in Example 3 with a needle-shaped material having a diameter of 0.4 mm, but it was extremely difficult.

Comparative Example 6 Using the sheet-like molded product obtained in Example 2, the diameter was 5
A cylindrical molded product having a height of 6 cm and a height of 6 cm was prepared. On the other hand, according to the method of Example 2 using the pellet-shaped molded product obtained in Example 2, the area of one hole of the mesh was about 440 mm ² , and the porosity was
A molded article having a grid-like network with a mesh thickness of 73% and an average thickness of 1 mm was prepared. This was adhered to a location that would be the bottom surface of the cylindrical molded product to produce a seedling-growing pot having the shape shown in FIG. The resulting nursery pots were of sufficient strength and shape to withstand use. An attempt was made to fill the seedling pot with soil that had been heat-sterilized at 100 ° C. for 1 hour, but the sterilized soil had spilled out from the gaps in the mesh and was not practical.

[0035]

Since the seedling pot of the present invention uses a biodegradable resin as a material, unlike the conventional seedling pots made of polyethylene resin or vinyl chloride resin, the seedling seedling pot is used when transplanting the seedlings. The seedling pots can be transplanted into the soil without having to pull them out of the soil. In addition, since it is made of a molded product obtained by adding a filler to a biodegradable resin, the decomposition rate can be improved, and it can be manufactured at low cost. Furthermore, since there are a number of holes on the bottom surface of the seedling raising pot, it is possible to prevent the pot from decreasing in strength and to extend the roots of the seedlings into the soil through the holes.

[Brief description of the drawings]

1A and 1B are a perspective view and a plan view, respectively, of an example of a seedling raising pot of the present invention.

FIGS. 2A and 2B are a perspective view and a plan view, respectively, of another example of the seedling raising pot of the present invention.

[Explanation of symbols]

 1 ... pot body, 2 ... holes, 3 ... mesh.

Claims (1)

[Claims] (1) 100 parts by weight of a biodegradable resin and 10 to 150 fillers
Weight part, and the bottom has a cross section of 0.2 ~
In 100 mm ^2, porosity of the bottom portion is 30% to 90%, seedling pots, characterized in that it has a number of holes.