JP3765369B2

JP3765369B2 - Biodegradable aquatic plant support for greening, aquatic plant structure and floating island structure using the same

Info

Publication number: JP3765369B2
Application number: JP21108899A
Authority: JP
Inventors: 俊也山本
Original assignee: Toyobo Co Ltd
Current assignee: Toyobo Co Ltd
Priority date: 1999-07-26
Filing date: 1999-07-26
Publication date: 2006-04-12
Anticipated expiration: 2019-07-26
Also published as: JP2001032236A

Description

【０００１】
【発明の属する技術分野】
本発明は湖岸、河川等の護岸の緑化を行うための緑化用生分解性水生植物支持体、それを用いた水生植物構造体と浮島用構造体に関する。
【０００２】
【従来の技術】
一般に湖岸、河川等の護岸における水生植物による緑化は、ヤシなどの天然繊維をネットなどに詰めた支持体に水生植物の苗を植え込み、ある程度成長したものをコンクリート護岸に敷設していた。それらの製作プロセスは、まず苗の植え込みはヤシ繊維で包んだポットにある程度成長させた苗を作成する。さらにそれらをヤシ繊維の詰まった構造体に植え込みそれらをある程度成長させたものを護岸に敷設していた。これらのプロセスにおいてはたいへんな時間と労力を要するという問題があった。
【０００３】
一方それらの作業性が改善された支持体、具体的には熱可塑性樹脂の連続網状体の一部凹凸状にした水耕栽培用ユニット（特開平９−２７５８３０号公報）等が提案されていた。
これらは直接苗を凹の場所に植え込み、側面と下面で支持体と根を固定化させる事によって支持体との固定性をアップさせ、支持体構造物製作に要する時間を大幅に短縮させるのが狙いであった。しかしながら実際ある程度苗株を支持体内で成長させないと支持体と固定化する事ができず湖岸や河川に敷設した時、苗株が外れてしまう。ある程度の期間で苗株と支持体を固定化させるのであれば凹凸形状である必要もない。また植え込んだ根はほとんど下部方向に成長し、側面に成長する事はまれであり側面での固定力強化は期待できないという問題があった。
【０００４】
【発明が解決しようとする課題】
護岸、河川等の護岸の水生植物による緑化において、本発明は上記従来の問題点である水生植物支持体製作プロセス及び支持体と植物との固定化を改善する事ができる水生植物用支持体、苗が植え込まれた水生植物構造体及び浮島用構造体を提供せんとするものである。
【０００５】
【課題を解決するための手段】
本発明はかかる課題を解決するために次のような手段を採用したものである。すなわち本発明の水生植物支持体は生分解性熱可塑性樹脂を有する曲がりくねった多数の連続線状体が少なくとも一部で接合された三次元ランダムループを有する立体網状体からなり、水切り性が２０kg/m³で、板状の形状で、見掛密度が３０〜１００kg/m³である緑化用生分解性水生植物支持体であり、さらには、線状体間距離が最大で１０ｍｍである緑化用生分解性水生植物支持体及びそれらを用いた水生植物構造体と浮島用構造体である。
【０００６】
【発明の実施の形態】
本発明の水生植物支持体は植物を保持し根の成長を阻害しない様開放された空間を有し、水切り性が２０kg/m³以下であり、河川に敷設しやすい板状の形状であり、容易に水生植物を植え付けることができるものである。
【０００７】
本発明における水切り性は支持体を１分間水中に浸し、取り出した１分後の水分保持量（kg/m³）を示す。
【０００８】
水生植物支持体の水切り性が２０（kg/m³）を超えると護岸に敷設移動させる際の乾燥にたいへんな時間を要してしまう。
【０００９】
本発明の水生植物支持体は、連続線状体が生分解性熱可塑性樹脂の曲がりくねらせたランダムループを有する立体（三次元）網状構造体であるので、構造体中の空間に直接に苗株を把持することができ、この立体構造に切れ目を入れたり穴をあける必要がない。敷設までの時間において、従来の凹凸形状の支持体では苗株を植え込むと支持体との固定力が弱く、敷設後苗株が支持体より外れて流れてしまうことがあるが、本発明における立体網状構造体では、ある程度苗株を成長させ、支持体との固定化をさせた植物を安定して敷設できる。
【００１０】
本発明における立体網状構造体では、植物を保持し根の成長を阻害しない様な開放された空間を有し、水切り性が良い。板状の形状であるので河川に敷設し易い。立体網状体の見掛密度が３０〜１００kg/m³である。立体網状体の見掛密度が３０kg/m³未満であると支持体の安定性（水流による部材の安定性）が悪くなるのが問題である。見掛密度が１００kg/m³を超えると苗株の植え付け性、成長性、水切り性、及び植物固定力が弱くなる。
【００１１】
本発明における立体網状体において、ランダムループを形成する繊維間距離が最大１０ｍｍであることが好ましい。繊維間距離が最大１０ｍｍを超えると苗株を固定させることが困難となる。
【００１２】
本発明における立体網状体に使用される素材は生分解性熱可塑性樹脂である。使用される生分解性熱可塑性樹脂としては、ポリ‐β‐ヒドロキシ酢酸、ポリカプロラクトン、ポリブチレンサクシネート、ポリ乳酸などが好ましい。また、ポリエステル系、ポリオレフィン系、ポリアミド系、ポリカーボネート系等のエンジニアプラッチックや熱可塑性エラストマーとの混合物であっても良い。
【００１３】
生分解性熱可塑性樹脂の曲げ弾性率は１００００kg／cm²未満が好ましく、より好ましくは８０００未満であり、特に好ましくは８０００kg／cm²未満で２０００kg／cm²以上である。
【００１４】
使用される支持体の厚さは１０ｍｍ以上必要であり、これより低いと植物の根が貫通し支持体との固定力が弱くなり、より好ましくは厚さ３０ｍｍ〜９０ｍｍであり、この場合、植物の固定が容易にでき、コンクリート護岸への敷設も容易にできる。支持体の厚さが１０ｍｍ未満であると、植物との固定力不足で植物が成長すると茎が倒れてしまう。
【００１５】
本発明における水生植物を植え込んだ水性生物構造体は、浮力枠体に取り付けて浮島構造体として使用することができる。
【００１６】
緑化用水生植物にはヨシ、ガマ、セキショウ、スゲ、花ショウブ、クレッソンなどの多年草で成長が早い物が用いられる。
【００１７】
【実施例】
実施例１
厚さ４５ｍｍ、見掛密度５３kg/m³のポリ乳酸樹脂製立体網状体にヨシの苗株を植え付けた水生植物構造体を得た。苗株の植え込みは直接網状体に行い、苗の成長後支持体ごと河川コンクリート護岸に使用した。支持体の水切りは数分で完了した。敷設後水流で植物が外れる事なく順調に成長した。またこれらは浮力をつけて浮島の植生体にも使用した。浮島で成長したヨシの茎が倒れる事なく湖岸緑化を行う事ができた。
【００１８】
実施例２
厚さ６０mm 、密度８０kg/m³の前記のポリ乳酸と曲げ弾性率３５００kg／m³のポリエチレンエラストマー樹脂との混合物製立体網状体に花ショウブの苗を植え付けた水生植物構造体を得た。苗株の植え込みは直接網状体に行い、苗の成長後支持体ごとコンクリート護岸に敷設した。支持体の水切りは数分で完了した。敷設後水流で植物が外れる事なく順調に成長した。
これらにおいても実施例1と同様にして浮力をつけて浮島の構造体として使用したところ、花ショウブの茎が倒れる事なく花を付けて成長し、湖岸緑化を行う事ができた。
【００１９】
比較例１
円筒形のナイロンネットにヤシ繊維を充填して直径３０ｃｍ、長さ３ｍの円筒状の支持体を得た。この支持体に苗株の根の部分をヤシ繊維で包まれたある程度発育したヨシの苗株を、前述の円筒状のヤシ繊維に植え込んだ。その際円筒状に充填されたヤシ繊維を冶具を用いて一部抜き取り、その場所に植え込むという作業を行った。苗の成長後、コンクリート護岸に敷設したが、円筒ロールの水を切るために８時間程度の時間を要した。敷設後水流で円筒がいがみ、植物が一部水浸かってしまった。敷設後１年で自然分解により一部植物が外れてしまった。
【００２０】
比較例２
厚さ３０ｍｍ、見掛密度２０kg/m³の塩ビ繊維構造体に花ショウブの苗株を植え付けたものを得た。苗株の植え込みは直接網状体に行い、苗株の成長後支持体ごと河川コンクリート護岸に敷設した。支持体の水切りは数分で完了した。敷設後水流で一部植物が外れてしまった。
【００２１】
比較例３
厚さ３０ｍｍ、見掛密度１５０kg/ｍ³のポリエステル樹脂製立体構造体にヨシの苗株を植え付けたものを得た。苗株の植え込みは切れ目をいれて行ったが、苗の成長の際、根の成長が遅く繊維の隙間に根が入り込まなかった。苗の成長後支持体ごと河川コンクリート護岸に敷設した。支持体の水切りは３時間で完了した。敷設後水流で支持体ごと流れてしまった。
【００２２】
比較例４
基底部の厚みが２０ｍｍ、側面部が８０ｍｍ、フィラメント径１．８ｍｍ、目付１５００g/m²、空隙率９５％のポリプロピレン製凹凸立体網状体を河川護岸に敷設した。凹凸立体網状体の凹み部にヨシの苗株を落とし込んだが、ほとんどが支持体と固定できず苗が水流により外れて成長しなかった。
【００２３】
【表１】

【００２４】
【発明の効果】
本発明の生分解性水生植物支持体は製造が容易であるのみならず水生植物の成長性に優れ、かつ水生植物の敷設作業性に優れ、さらに水生植物の保持性に優れ、支自体自身が生分解性を有しており、環境汚染や環境ホルモンなどの問題もなく、湖岸、河川等の護岸緑化及び浮島による緑化に好適である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a biodegradable aquatic plant support for revegetation for revegetation of revetments such as lakes and rivers, aquatic plant structures and floating island structures using the same.
[0002]
[Prior art]
In general, greening by aquatic plants on lakesides, rivers, etc., was carried out by planting seedlings of aquatic plants on a support made of natural fibers such as palms packed in a net, and laying them on concrete revetments that grew to some extent. In the production process, seedlings are first planted to a certain degree in a pot wrapped with palm fibers. Furthermore, they were laid on the revetment after they were planted in a structure filled with palm fibers and grown to some extent. These processes have a problem of requiring a lot of time and labor.
[0003]
On the other hand, a support having improved workability, specifically, a hydroponic cultivation unit (Japanese Patent Laid-Open No. 9-275830) and the like in which a continuous network of thermoplastic resin is partially uneven has been proposed. .
They can directly plant seedlings in concave areas and fix the support and roots on the side and bottom surfaces, thereby improving the fixability of the support and greatly reducing the time required to manufacture the support structure. It was the aim. However, in fact, if the seedlings are not grown to some extent in the support body, they cannot be immobilized with the support body, and when they are laid on the lake shore or river, the seedlings will come off. If the seedling and the support are fixed for a certain period of time, it does not have to be uneven. In addition, the planted roots grow almost downwards, rarely grow on the side, and there is a problem that the fixing strength on the side cannot be expected.
[0004]
[Problems to be solved by the invention]
In revegetation by aquatic plants on revetments, rivers, etc., the present invention provides a support for aquatic plants that can improve the aquatic plant support production process and immobilization of the support and plants, which are the above-mentioned conventional problems, An aquatic plant structure in which seedlings are implanted and a structure for floating islands are provided.
[0005]
[Means for Solving the Problems]
The present invention employs the following means in order to solve such problems. That is, the aquatic plant support of the present invention comprises a three-dimensional network having a three-dimensional random loop in which a large number of winding continuous linear bodies having a biodegradable thermoplastic resin are joined at least partially, and has a water drainage of 20 kg / in m ^3, a plate-like shape, apparent density of planting for biodegradable aquatic plant support is 30~100kg / m ^3, more, for greening distance between the linear body is 10mm in maximum Biodegradable aquatic plant supports, aquatic plant structures and floating island structures using them.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The aquatic plant support of the present invention has an open space so as to retain plants and not inhibit root growth, has a drainability of 20 kg / m ³ or less, and has a plate-like shape that is easy to lay in a river. Aquatic plants can be easily planted.
[0007]
The drainage property in the present invention indicates a water retention amount (kg / m ³ ) 1 minute after the support is immersed in water for 1 minute.
[0008]
If the drainage of the aquatic plant support exceeds 20 (kg / m ³ ), it will take a very long time to dry the laying revetment.
[0009]
Since the aquatic plant support of the present invention is a three-dimensional (three-dimensional) network structure in which the continuous linear body has a random loop in which the biodegradable thermoplastic resin is twisted, the seedling is directly formed in the space in the structure. The strain can be gripped and there is no need to cut or perforate this three-dimensional structure. In the time until laying, in the conventional uneven support, when the seedling is planted, the fixing force with the support is weak and the seedling may flow out of the support after laying, In the net-like structure, a plant having a seedling grown to some extent and immobilized on a support can be stably laid.
[0010]
The three-dimensional network structure in the present invention has an open space that holds plants and does not inhibit root growth, and has good drainage performance. It is easy to lay in the river because it is plate-shaped. The apparent density of the three-dimensional network is 30 to 100 kg / m ³ . If the apparent density of the three-dimensional network is less than 30 kg / m ³ , the problem is that the stability of the support (stability of the member due to water flow) deteriorates. When the apparent density exceeds 100 kg / m ³ , the planting ability, growth ability, draining ability, and plant fixing power of the seedlings become weak.
[0011]
In the three-dimensional network in the present invention, it is preferable that the distance between fibers forming a random loop is 10 mm at the maximum. If the inter-fiber distance exceeds 10 mm at the maximum, it becomes difficult to fix the seedling.
[0012]
The material used for the three-dimensional network in the present invention is a biodegradable thermoplastic resin. As the biodegradable thermoplastic resin used, poly-β-hydroxyacetic acid, polycaprolactone, polybutylene succinate, polylactic acid and the like are preferable. Further, it may be a mixture with an engineer plastic or thermoplastic elastomer such as polyester, polyolefin, polyamide or polycarbonate.
[0013]
The flexural modulus of the biodegradable thermoplastic resin is preferably less than 10000 kg / cm ² , more preferably less than 8000, particularly preferably less than 8000 kg / cm ² and 2000 kg / cm ² or more.
[0014]
The thickness of the support used is required to be 10 mm or more. If the thickness is lower than this, the root of the plant penetrates and the fixing force to the support becomes weak, and more preferably the thickness is 30 mm to 90 mm. Can be easily fixed, and can be easily laid on a concrete revetment. When the thickness of the support is less than 10 mm, the stem falls when the plant grows due to insufficient fixing force with the plant.
[0015]
The aquatic organism structure in which the aquatic plant according to the present invention is implanted can be used as a floating island structure by being attached to a buoyancy frame.
[0016]
As aquatic plants for greening, perennials such as reeds, cattails, buffalo, sedges, flower ginger, and cressons are used.
[0017]
【Example】
Example 1
An aquatic plant structure in which a reed seedling was planted on a three-dimensional network made of polylactic acid resin having a thickness of 45 mm and an apparent density of 53 kg / m ³ was obtained. The seedlings were planted directly in the net, and the seedlings were used for river concrete revetment after the growth of the seedlings. The draining of the support was completed in a few minutes. After laying, it grew steadily without any detachment of plants due to water flow. They were also used for vegetation on floating islands with buoyancy. Lakeside greening was possible without falling down the stems of reeds grown on floating islands.
[0018]
Example 2
Thickness 60 mm, to obtain the polylactic acid and bending aquatic plant structure planted seedlings flowers iris mixture made stereoscopic net of polyethylene elastomer resin elastic modulus 3500 kg / m ³ of density 80 kg / m ^3. Seedlings were planted directly in the net, and after the seedlings were grown, the support was laid on the concrete revetment. The draining of the support was completed in a few minutes. After laying, it grew steadily without any detachment of plants due to water flow.
In these cases as well, the buoyancy was applied in the same manner as in Example 1 to use as a floating island structure. As a result, the stems of the flower shovel grew without falling down, and the lakeside greening could be performed.
[0019]
Comparative Example 1
A cylindrical nylon net was filled with palm fiber to obtain a cylindrical support having a diameter of 30 cm and a length of 3 m. A reed seedling that grew to some extent, in which the root part of the seedling was wrapped with palm fiber on this support, was planted in the cylindrical palm fiber described above. At that time, a part of the palm fiber filled in a cylindrical shape was extracted with a jig and planted there. After growing the seedling, it was laid on a concrete revetment, but it took about 8 hours to drain the water from the cylindrical roll. After laying, the cylinder was distorted by the water flow, and some plants were submerged. In one year after laying, some plants were removed due to natural decomposition.
[0020]
Comparative Example 2
A plant obtained by planting a seedling of a flower shovel on a PVC fiber structure having a thickness of 30 mm and an apparent density of 20 kg / m ³ was obtained. The seedlings were planted directly in the net, and after the seedlings were grown, the support was laid on the river concrete revetment. The draining of the support was completed in a few minutes. After laying, some plants have fallen off due to water flow.
[0021]
Comparative Example 3
A polyester resin three-dimensional structure having a thickness of 30 mm and an apparent density of 150 kg / m ³ was planted with reed seedlings. The seedlings were planted with cuts, but when the seedlings grew, the roots grew slowly and the roots did not enter the gaps in the fibers. After seedling growth, the entire support was laid on the river concrete revetment. The draining of the support was completed in 3 hours. After laying, the water flowed with the support.
[0022]
Comparative Example 4
A rugged three-dimensional network made of polypropylene having a base portion thickness of 20 mm, a side portion of 80 mm, a filament diameter of 1.8 mm, a basis weight of 1500 g / m ² , and a porosity of 95% was laid on the river revetment. Although the seedlings of reed were dropped into the dents of the rugged three-dimensional network, most of them could not be fixed to the support and the seedlings did not grow due to water flow.
[0023]
[Table 1]

[0024]
【The invention's effect】
The biodegradable aquatic plant support of the present invention is not only easy to produce, but also has excellent aquatic plant growth performance, excellent aquatic plant laying workability, excellent aquatic plant retention, and the branch itself It is biodegradable and has no problems such as environmental pollution and environmental hormones. It is suitable for revetment greening on lake shores, rivers, etc. and greening on floating islands.

Claims

生分解性熱可塑性樹脂を有する曲がりくねった多数の連続線状体が少なくとも一部で接合された三次元ランダムループを有する立体網状体からなり、水切り性が２０kg/m³以下であり、板状の形状で、見掛密度が３０〜１００kg/m³である緑化用生分解性水生植物支持体。It consists of a three-dimensional network having a three-dimensional random loop in which a large number of meandering continuous linear bodies having a biodegradable thermoplastic resin are joined at least partially, and has a water drainability of 20 kg / m ³ or less, and has a plate-like shape. A biodegradable aquatic plant support for greening having a shape and an apparent density of 30 to 100 kg / m ³ .

前記立体網状構造体を形成する線状体間距離が最大で１０ｍｍである請求項１記載の水生植物支持体。The aquatic plant support according to claim 1, wherein the distance between the linear bodies forming the three-dimensional network structure is 10 mm at the maximum.

請求項１の水生植物支持体を用いた浮島用構造体。The structure for floating islands using the aquatic plant support body of Claim 1.