JP2002345348A - Agricultural mulch film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural mulch capable of fixing a nursery bed even if used for a long period without deteriorating an inherent characteristic of a biodegradable plastic and being biodegraded after use. SOLUTION: This agricultural mulch film made of the biodegradable plastic material is characterized by forming a coating layer comprising a resin originating from natural product colored by a food color on at least one side of the part of a long length film to be covered with soil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an agricultural multi-film, and more preferably to an agricultural multi-film made of a biodegradable plastic material.

[0002]

2. Description of the Related Art Conventionally, agricultural multi-films have been used for promoting germination, protecting crops, growing, and the like. This agricultural multi-film is a long plastic film. After covering the entire surface of the ridges of the seedbed, holes are formed at regular intervals in the center of the film to grow crops, and both sides of the film are continuous. It is fixed to the field by covering the soil.

In recent years, attempts have been made to make agricultural multi-films made of biodegradable plastic. Since the biodegradable plastic film is decomposed and disappeared by microorganisms in the soil, it can be treated by combing the used film into the soil. Therefore, if the agricultural multi-film becomes biodegradable plastic, there is no danger of generating harmful substances by incinerating the used film as in the conventional case.

[0004] However, when a biodegradable plastic agricultural multi-film is used, biodegradation starts only in a portion covered with soil for fixing the film, and the film in that portion disappears. There is a problem that it cannot be fixed.

[0005]

SUMMARY OF THE INVENTION The present invention provides an agricultural multi-film capable of fixing a nursery bed even when used for a long period of time without deteriorating the inherent properties of biodegradable plastic, and biodegradable after use. provide. Further, in the present invention, by coating a coating layer applied for suppressing the biodegradation rate with an edible dye which is safe for food hygiene, the coated area can be easily distinguished.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an agricultural multi-film made of a biodegradable plastic material, wherein at least one surface of a long film covered with soil is derived from a natural product colored with an edible pigment. The present invention relates to an agricultural multi-film formed by forming a coating layer made of a resin. Further, the present invention relates to the agricultural multi-film, wherein the resin derived from a natural product is a shellac resin.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. A coating layer 3 is formed on both sides of an agricultural multi-film 2 covering a ridge 1.

In the present invention, "biodegradation" refers to the property of being completely decomposed into carbon dioxide by microorganisms. The biodegradable plastic according to the present invention includes poly (3-hydroxybutanoic acid), poly (3-hydroxybutanoic acid-co-
3-hydroxyvaleric acid), polycaprolactone, polybutylene succinate, poly (butylene succinate-c)
o-adipate), polyethylene succinate and the like. These plastics may be a mixture of two or more plastics. The agricultural multi-film of the present invention is obtained by forming these biodegradable plastics into a film having a thickness of 10 to 30 μm.

The natural product-derived resin of the present invention is a natural product itself or a substance extracted from a natural product, and has the ability to be soluble in an organic solvent or to form a water-resistant film by hot melting, Form a barrier layer against microorganisms by being coated on the plastic film surface,
Suppress the biodegradation rate of biodegradable plastic.

[0010] Examples of such a resin include zen (corn protein), glutelin, shellac, carnauba wax, candy wax, rice wax, wood wax, beeswax, spermaceti, montan wax, ozokerite, ceresin and the like.

The preferred resin in the present invention is shellac, and in particular, specific gravity 1.02 to 1.12, saponification degree 185 to 290, acid value 75 to 105, and iodine value 8.0.
~ 15.0 are preferred.

The edible colorant (B) in the present invention is not particularly limited. Red No. 105 Rose Bengal, Edible Red No. 106 Acid Red, Edible Yellow No. 4 Tartrazine, Edible Yellow No. 5 Sunset Yellow,
Edible Green No.3 Fast Green, Edible Blue No.1 Brilliant Blue, Edible Blue No.2 Synthetic Colorants such as Indigo Carmine, Gardenia Yellow Element, Safflower Yellow Element, Turmeric Dye, Benikouji Yellow Element, Benikouji Color, Gardenia Red Dye, Safflower Red Element, cochineal pigment, lac pigment, madder pigment, perilla pigment Red cabbage pigment, purple potato pigment, grape skin pigment, elderberry pigment, capsicum pigment, annatto pigment, gardenia blue, gardenia yellow, safflower yellow, Benikouji yellow, chlorophyll, spirulina Pigment, cacao pigment, tamarind pigment, oyster pigment,
Natural coloring agents such as vegetable charcoal pigments may be mentioned. They are,
One type or two or more types can be used. ,

In the present invention, the coating layer of a resin derived from a natural product may be coated with a conventionally known coater by dissolving the resin in a solvent such as ethanol or melting the resin. Coating layer thickness is 1-50μm
Is preferred. The degree of suppression of the biodegradation rate of the biodegradable plastic can be changed depending on the thickness of the coating layer, the pattern of patterning by printing, and the like. The coating layer may be formed on a portion covered with soil in order to fix the film on both sides of the long film, and the coating surface may be one side or both sides of the film.

[0014]

EXAMPLE Both sides of a long caprolactone film (thickness: 20 μm) having a width of 1350 cm were adjusted to a wetting index of 46 or more by corona treatment, and both sides of the film were 4 mm from both ends.
0 cm, uniformly applied by a gravure method with a coating agent consisting of shellac 20% by weight, ethanol 40% by weight, chlorophyllin 0.5% by weight, water 30% by weight and calcium carbonate 9.5% by weight, and a 3 μm thick green color To form a colored coating layer. > In mid-August, the coated agricultural multi-film was covered with field soil on both sides with the coating, and fixed in the soil with the uncoated film center exposed to the outside. As a result of observing the shape of the film in the soil every three days, the film maintained its shape even after 30 days and completely collapsed on the 48th day.

[0015]

[Comparative Example] An agricultural multi-film not coated in the example was tested under the same conditions as in the example, and the shape of the film in the soil was observed. As a result, the film completely collapsed on the 18th day from the start date. Was.

According to the agricultural multi-film of the present invention, since the coating layer is selectively provided on the portion of the biodegradable plastic film which is covered with the soil, the portion is less susceptible to biodegradation. And can withstand the use of the period. Further, since the coating layer is colored, the coated area can be easily identified, so that the convenience in use is high. Furthermore, in the present invention,
The coating layer itself consists of resins and food dyes derived from natural products, and these substances are not only excellent in hygiene,
It is susceptible to biodegradation and has very low environmental impact, even if it remains in the environment.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state where an agricultural multi-film of the present invention is constructed.

[Explanation of symbols]

 Reference Signs List 1 ridge 2 agricultural multi-film 3 coating layer

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference) 2B024 DA02 DB01 4F006 AA35 AB01 AB02 AB03 BA17 CA06 DA04 4F100 AJ01B AJ01C AK01A BA02 BA03 CA13 EA02A EH46 EH462 GB01 JC00 JC00A JL10B JL10C

Claims (2)

[Claims] 1. An agricultural multi-film made of a biodegradable plastic material, wherein a coating layer made of a resin derived from a natural product colored with an edible pigment is formed on at least one surface of a portion of a long film covered with soil. A multi-film for agriculture characterized by being made. 2. The agricultural multi-film according to claim 1, wherein the resin derived from a natural product is a shellac resin.