JPS6010682B2 - Method for forming a protective film on weeding board for seedlings and weeding board obtained by the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for forming a protective film that imparts rust prevention and anticorrosion properties to a weeding board for seedlings within a predetermined period of time, and provides the function of quickly corroding and disintegrating after the period has passed. The present invention relates to a method and a weeding board obtained by the method.

Weeding boards for seedlings are placed around planted seedlings and are used to suppress the growth of weeds around the seedlings for several years and aid in the growth of the seedlings.

Traditionally, after planting trees in mountain forests, weeds grow around the seedlings.
This causes the growth of the seedlings to become overgrown and severely inhibit the growth of the seedlings.
It was necessary to remove weeds and shrubs around the seedlings. For this purpose, underbrush mowing work was carried out about twice a year using human labor tactics, but this work was not only inefficient, but also labor-intensive, and due to the lack of manpower, efforts were made to reduce the amount of labor involved in this work. was desired. Therefore, a weed removal board for afforestation and growth, which is placed around seedlings to suppress the growth of weeds, has been developed and disclosed in Japanese Patent Publication No. 52-1732.

This disclosed weeding board is only a steel plate or iron foil,
When used without any processing, corrosion progresses from both the front and back surfaces at the same time. In order to withstand this corrosion and last for about 3 to 5 years, that is, until the seedlings have grown to such an extent that undergrowth is not necessary, the thickness of the board must be made considerably thick. If the weeding board is made thicker, it is not only economically disadvantageous due to wasted material, but also has the drawback that the workability is extremely poor when carrying and installing the board at the site. In particular, the surface that comes into contact with the ground during installation is constantly exposed to moisture, and is susceptible to severe corrosion and becomes brittle. After about 10 months, it becomes tattered and no longer fulfills its role. One possibility is to apply a corrosion-resistant paint to one side of the weeding board, or to form a film of polyethylene, polypropylene, polyvinyl chloride, etc., but if such processing is applied, Even after it is no longer needed as a weeding board five years later, it remains uncorroded and remains for a long time, which is undesirable as it actually hinders the growth of seedlings. Therefore, the present invention suppresses the weeding function during the period when weeding is necessary to fully exert its weeding function, and when weeding is no longer necessary, it rapidly decays and decays, returns to the soil, and helps the growth of seedlings. The object of the present invention is to provide a weeding board for seedlings and a method for forming a protective film thereon.

The present invention, which was made to achieve this purpose, involves cleaning the back side of an appropriately sized iron board or iron foil with a through hole for seedlings in the center with an alkaline cleaning agent, and then using a phosphate chemical treatment liquid. A method for forming a protective film on a weeding board for seedlings, which comprises washing with water after chemical conversion treatment, and coating the back side with a photodegradable resin film after drying, and the weeding board, the weeding board comprising phosphate chemical treatment. The photo-degradable resin coating is applied evenly and with good adhesion to the metal plate surface, resulting in uniform corrosion over the entire surface, so if weeding is necessary, weeding can be done on the entire surface. It takes on a plate-like shape in a stable state, and when weeding is no longer necessary, it decays and collapses all at once, and it no longer interferes with the growth of seedlings.

Next, the present invention will be explained in more detail with reference to the illustrated embodiment. Reference numeral 1 denotes a weeding board made of a thin iron plate or iron foil having a substantially rectangular shape, and a round hole 2 of an appropriate size in the center of which a seedling is inserted. is formed, and a cut 3 is provided from the round hole approximately perpendicular to one side of the square shape, and each corner part 4 of the square shape is bent downward to protrude into the ground for stable installation. .

It is preferable that the cuts 3 overlap if possible to prevent light from leaking downward.

The above-mentioned weeding board 1 is laid so as to cover the roots of the planted seedlings 5 as shown in Fig. 2.
At the time of this laying, the cut portions 3 are opened in alternate directions and the seedlings 5 are inserted into the round holes 2 so that they are positioned, and the four corner portions 4 are bent so as to be in contact with the ground 6. to stabilize it.

One side of the weeding board 1 made of such iron plate or iron foil is specially processed on the back surface which is the grounding side.

First, the back side of the weeding board 1 is cleaned by degreasing with an alkaline detergent, then chemical conversion treatment is performed with a phosphate chemical treatment solution to form a chemical conversion film 7, and after washing and drying, a photodegradable resin solution is applied. The resin film 8 is uniformly coated by means such as spraying, brushing, flow coating, roll coating, electrostatic coating, or smear coating. In this case, the resin coating 8
The treatment step before coating improves the uniformity and adhesion of the resin coating, thereby ensuring uniform service life, ie, uniform corrosion and uniform disintegration. If the photo-degradable resin is a film, a photo-degradable resin film 8a may be attached via an adhesive layer 9, as shown in FIG.

Furthermore, depending on the seedling, if the growth rate is low and weeding is required for more than 5 years, as shown in Figure 5, weeding board 1
For example, another resin coating 10 is applied to the upper surface of the
may be formed. This resin coating is not very resistant to weeding, so it may be omitted, and it may be sufficient to extend the life of the weeding board by at most 1 to 2 years. The weeding board 1 used is not limited to iron, but may be made of other metals, although iron is suitable since it is returned to the soil after decay due to corrosion and helps the growth of seedlings.

In short, it is fine as long as it is easy to perform the rotten mosquito check. The thickness of the weeding board is preferably about 50 to 200 microns. In addition, the photodegradable resins used include carbon monoxide, methyl vinyl ketone, or ethylene-carbon monoxide and methyl methacrylate-methyl having a carbonyl or ketone group obtained from a copolymer with Q-acetyl pimelic acid. Polymer compounds such as vinyl ketone, Q-acetylpimelic acid-hexamethylene diamine, etc., and those obtained by adding the above compounds to thermoplastic resins such as general-purpose polyethylene, polypropylene, polyacetal, polyester, polystyrene, and pinyl chloride, etc. Blends, aromatic compounds such as naphthalene, anthracene, and pyrene that impart photodegradability, hexachlorobenzene,
Halogen compounds such as 1,1,2,2-titrabromoethane and hexabromobenzene, carboxylic acids such as atropaic acid, diphenylacetic acid, diphenylacetaldehyde, stearic acid, and benzaldehyde, ester and aldehyde compounds, and other compounds that impart photodegradability. Additives such as amine compounds such as orthotolylguanidine and phenyl-8-naphthylamine, heterocyclic compounds such as acridine and 2-mercaptobenzothiazole, sulfur compounds such as diphenyl sulfide and diphenyl disulfide, and organometallic compounds are mixed. Examples include polyethylene, polypropylene, polystyrene, polyester, polycarbonate, polymethacrylate ester, and the like. Polymers containing syndiotactic 1,2 polybutadiene can also be used as photodegradable resins, and the resin after disintegration can also be used as a soil conditioner, so it is particularly effective. Of course, these resins must be selected from those that do not become harmful substances or inhibit the growth of seedlings when they are reduced to the resin after photodegradation. The thickness of the photodegradable resin coating to be applied is 20~
It is about 100 microns. The weeding board according to the present invention has a photodegradable protective coating formed on the back side of the weeding board, and can be used by installing it around the base of planted seedlings for about 3 to 5 years after planting. It suppresses the growth of weeds, and especially prevents corrosion on the ground side of the weeding board, but it gradually corrodes only from one side, that is, the surface side.
5. Insects create holes in various places, and as light leaks through these holes, the resin coating on the back side gradually disintegrates and loses its protective function. Corrosion occurs and the weeding board becomes brittle and crumbly as a result of corrosion from both sides, and is eventually returned to the soil as iron, which is useful for the growth of seedlings.

Test Example 100 x 10 iron foil with a thickness of 100 microns was cleaned with an alkaline detergent, treated with a phosphate chemical treatment solution, washed with water, dried with warm air, and then coated with light decomposition on the back side. A 50-micron resin film mainly composed of syndioctic 1.2 polyptadiene having anti-corrosion properties was attached using a vinyl acetate-based adhesive 5 to 10 times a day.

In addition, acrylic lacquer (registered trademark) is applied to the front surface.
Table 1 shows the results of placing a weeding board coated with a 0 micron protective coating directly on the ground with the front side facing up and exposing it outdoors. Comparative Example In place of the photodegradable resin film of Test Example 1, a 50 micron thick polyethylene film was heat-sealed and similarly exposed outdoors. Table 1 shows the results.

Comparative Example 2 Table 1 shows the results of exposing the same weeding board as in Test Example, but without the photodegradable resin coating on the back surface, outdoors.

Table 1 As mentioned above, the weeding board obtained by the method of the present invention is made as thin as possible to make it convenient to handle, and the back side, which is prone to corrosion during use, is coated with a protective coating made of photodegradable resin. Since the corrosion progresses only from the surface side, even if the weeding board is made thinner, the degree of corrosion is less than half, and the usable life is extended.

When a certain period of time has passed and weeding is no longer necessary, the protective film collapses due to light, and at the same time it loses its protective function, it corrodes from the back side as well, causing corrosion and collapse from both the front and back sides of the weeding board. This contributes to proper weeding and the growth of seedlings. In particular, the method of the present invention has excellent effects in that the protective coating of the weeding board is applied uniformly and with good adhesion, so that there is no variation in service life during use, and uniform corrosion can be expected.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a weeding board having a protective coating applied by the method of the present invention, Fig. 2 is a cross-sectional view of the weeding board in use, and Fig. 3 is a partially enlarged sectional view of the weeding board. , 4th
FIG. 5 is a partially enlarged sectional view of another embodiment. 1... Weeding board, 2... Round hole, 3...
... cut, 4 ... corner, 5 ... seedling, 6 ... soil, 7 ... chemical conversion coating, 8
, 8a... Photo-degradable resin coating, 9... Adhesive. Leopard 1 screen, 2 screens, 3 screens, 4 screens, 5 traditional screens

Claims (1)

[Scope of Claims] 1. The back side of an appropriately sized thin iron plate or iron foil having a hole through the seedling in the center is cleaned with an alkaline cleaning agent, then chemically treated with a phosphate chemical treatment solution, and then washed with water. A method for forming a protective film on a weeding board for seedlings, comprising: coating the back surface with a photodegradable resin film after drying. 2. A weeding board for seedlings made of an appropriately sized thin iron plate or iron foil having a hole through the seedling in the center, characterized in that the back side of the weeding board is coated with a photodegradable resin coating. .