JP2742347B2 - Biodegradable non-woven molded container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded container used in the field of agriculture and horticulture such as a seedling pot or a plug pot, and more particularly, it is hardly decomposed during the seedling period in the air. The present invention relates to a molded container made of a biodegradable nonwoven fabric which maintains its strength, is rapidly degraded in soil, and is eventually completely degraded.

[0002]

2. Description of the Related Art Seedling pots used in the agricultural and horticultural fields include unglazed pots, peat moss, paper, plastic pots, and containers for raising seedlings made of non-woven fabric obtained by thermocompression bonding a thermoplastic synthetic fiber web (Japanese Patent Laid-Open No. 57-94225) and the like, and in a plug pot, a wet-molded body (so-called pulp mold) using waste paper is used.
In recent years, from the viewpoint of ease of handling and price, demand for plastic molded articles (polypots and the like) of vinyl chloride and polyethylene has been increasing.

[0003]

However, the above-mentioned plastic molded article is treated as industrial waste as a disposal problem after use, and harmful gases are generated at the time of incineration, and the incinerator itself is damaged due to high temperature. There are drawbacks.

[0004] Further, as the seedlings grown in such a molded container grow, they need to be replanted into large pots or open fields, so-called transplantation. In addition, there is a problem that the labor of this transplant becomes enormous.

In pulp molded products, waste paper as a raw material contains substances that inhibit biodegradation such as lignin, and therefore remains for a long time even after transplanting to open ground, and has an adverse effect on root growth (so-called root tension). In addition, there are problems that the water absorption is too high, the water resistance is low, and the shape retention is poor. Containers made of nonwoven fabric made of synthetic fibers are not biodegraded, become bulky garbage, and have problems such as generation of harmful gases during incineration and damage to the incinerator.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made of cellulose fibers such as regenerated fibers such as viscose and copper ammonia rayon and vegetable natural fibers such as cotton and hemp. At least 10 g / m ² of a nonwoven fabric web having a basis weight of 30 g / m ² or more obtained by using animal protein fibers such as silk and wool alone or by mixing a plurality of them.
% By weight of ethylcellulose and its derivatives, polycaprolactone, hydroxypropylcellulose, polymerization degree 50
0 or less of vinyl acetate-vinyl alcohol copolymer, a thermoplastic resin having biodegradability such as thermoplastic polyvinyl alcohol having biodegradability is attached thereto, and the above problem is solved by a molding container which is thermocompression molded in a mold. It has been resolved.

Further, in order to control the decomposition period,
That is, during the seedling raising in the air, the decomposition is delayed by the soil put in the molding container, so that an inorganic antibacterial agent such as cellulose-acetate resin or zeolite on the inner surface, or an inorganic or aliphatic repellent such as silicon is used. A biodegradable plastic containing chitosan-cellulose as a main component or a thermoplastic resin having biodegradability used in molding is sprayed or applied as a biodegradable delayed plastic mixed with a liquid agent.

Further, in order to decompose and disappear immediately after transplantation to an open field, a biodegradable binder containing chitosan-microcellulose as a main component alone or a carbohydrate such as corn starch or starch, or rice bran on the outer surface is used. Or a composite binder mixed with a plasticizer such as glycerin or a vegetable protein such as glycerin or the like as a decomposition-promoting plastic to obtain a molded container formed.
The short-lived biodegradable plastic is 1 ~
A plastic that biodegrades in two months, and a plastic that biodegrades over a long period of time is one that biodegrades in soil for more than one year.

[0009]

Since the molded container of the present invention has a biodegradable function, it is completely decomposed by microorganisms in the soil after use, and there is no need for incineration. It does not hurt.

Furthermore, there is no need to take out the seedlings from the molded body and transplant them, and there is no need to worry about damaging the roots and dying during the replanting work, and the labor of the work can be saved. In addition, since it is porous, the roots of the plant extend in all directions of the container, and the growth of the plant is promoted.

In particular, the plastic which decomposes in a short period of time adheres to the inner surface of the molding container and the plastic which decomposes in a long period of time adheres to the outer surface, so that the decomposition is delayed during the seedling raising period, It retains its strength and decomposes and disappears promptly after being embedded in the open ground, and can be used without affecting rooting.

The configuration of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the biodegradable non-woven fabric molded container of the present invention, FIG. 2 is a perspective view of another example, and FIG. 3 is a partially enlarged sectional view of FIG. As shown in the figure, a non-woven fabric substrate 2 constituting a molded container 1 is made of a regenerated fiber such as viscose or copper ammonia rayon, a cellulosic fiber 3 such as vegetable natural fiber such as cotton or hemp, and a silk or wool or the like. It is obtained by mixing the animal protein fiber 3 alone or by mixing, and the basis weight is at least 30 g / m ² or more.
When it is less than 0 g / m ^2, the strength of the molded body itself is not obtained, and the so-called self-sustainability is lost.

On the other hand, if the basis weight is excessively large, the fabric becomes dense and loses water permeability and air permeability, causing root rot and the like.
Therefore, a desirable range varies depending on the size and shape of the molded body, but it is 100 (3 or 4) to 30 in the shape of a seedling raising pot.
0 (No. 7 to 8) g / m ² , 50 to 50
150 g / m ² , but is not limited thereto.

As a binder for the nonwoven fabric substrate 2, a biodegradable thermoplastic resin 4 such as ethylcellulose and its derivatives, caprolactone, hydroxypropylcellulose, vinyl acetate having a polymerization degree of 500 or less is used in consideration of biodegradability. A vinyl alcohol copolymer or a vinyl alcohol having biodegradability is used.
It may be 0% by weight or more. If the amount is less than the above, a sufficient shape-retaining property cannot be obtained even by hot-press molding. If the amount is excessive, a thermoplastic resin having biodegradability at the time of molding is formed into a film, and the water permeability and air permeability of the pot are increased. Is lost. A desirable range depends on the basis weight of the fiber, but an appropriate amount is 10 to 40% by weight.

If the nonwoven fabric substrate obtained by the above constitution is hot-pressed, a molded container having biodegradability can be obtained.
Depending on the type of plant to be raised, it may take a long period of 1 to 2 months for raising the seedlings. Microorganisms contained in the soil placed inside the forming container decompose the inner surface of the forming container, reduce the strength, and increase the seedling pot. This will cause the mold to lose shape.

Therefore, in order to prevent this, the cellulose acetate resin, chitosan salt (lactic acid,
Chitosan was adjusted to a concentration of 0.5 to 1.0% in an aqueous solution of an organic acid such as acetic acid at a concentration of 0.5 to 1.0%) and fine cellulose at a solid content ratio of 20 to 30: 80 to 70. A biodegradable binder is mixed with an inorganic antibacterial agent such as zeolite or an inorganic water repellent such as silicon or an aliphatic water repellent, and dispersed and applied as a plastic 5 which is biodegradable for a long period of time. And the like, so that the decomposition period is delayed by coating.

The above-mentioned biodegradable plastics 5
The amount of adhesion, the fibers constituting the basis weight of the molding vessel, shape, is determined by raising seedling period, 10 g / m 2 in seedling pots ^shape, sufficiently objective is achieved if 5 g / m ² or more plug cup-shaped, the When the amount is less than the amount of adhesion, the effect gradually decreases. In addition, if the mixed solid content ratio of chitosan and fine cellulose, which is a biodegradable binder containing chitosan-cellulose as a main component, is outside the above range, sufficient strength and water resistance as a binder cannot be obtained.

When the above-mentioned molded container is transplanted to an open field or the like, the above-mentioned biodegradable binder is used alone on the outer surface of the molded container so as to be rapidly dissolved and eliminated, or a carbohydrate such as corn starch and starch is added thereto. The composition is such that a composite binder mixed with a vegetable protein such as rice bran and a plasticizer such as glycerin is sprayed or applied as a decomposition-promoting plastic 6 so as to be rapidly decomposed in soil, and the amount of the adhered seedling is 10 g / m ^{2 in the} pot,
A plug pot of 5 g / m ² or more is sufficient, and if the amount is less than the above amount, the effect gradually decreases. It is also possible to delay the decomposition period by increasing the amount of plastic that decomposes over a long period of time.

[0020]

The present invention will be described below in more detail with reference to specific examples and comparative examples.

Example 1 Wool (fiber diameter: 20 to 40 μm, length: 15 to 80 mm) 7
0% and rayon 2d × 51 mm 30% were mixed, and 20 g of ethyl cellulose (N-7, manufactured by Hercules, USA) dissolved in xylene at a concentration of 5% on a nonwoven web having a basis weight of 100 g / m ² obtained by a known web forming machine. / M
⁽² ) The nonwoven fabric substrate formed by adhesion is thermoformed with a mold to form a seedling pot, and a cellulose-acetate resin (manufactured by Art Plus) is formed on the inner surface of the pot.
15 g / m ² , and a biodegradable binder (solid content ratio of chitosan-fine cellulose = 3) on the outer surface.
0:70) was adhered at 10 g / m ² to obtain a molded container.

Example 2 Wool (20 to 40) obtained in the same manner as in Example 1
μ, 15-80 mm) 70% and rayon 2d × 51m
m30%, after polycaprolactone was 70 g / ^{m 2} adhered to a nonwoven web having a basis weight 250 g / ^{m 2,} and heat molded to a pot shape in a mold, cellulose the inner surface -
20 g / m ^{2 of an} acetate resin is adhered, and a starch (chitosan: fine cellulose:
10 g / m ^{2 of} a composite binder mixed with starch (30:70:10) was attached to obtain a molded container.

Example 3 A non-woven web having a basis weight of 50 g / m ² obtained in the same manner as in Example 1 was coated with 7 g / m ² of a thermoplastic polyvinyl alcohol having biodegradability (VINEX1003 manufactured by Air Products, USA). After hot-press molding to form a plug pot, a zeolite antibacterial agent (chitosan: fine cellulose: antibacterial agent = 30: 7)
0: 2) was adhered at 5 g / m ² and starch (chitosan: chitosan:
A composite binder mixed with fine cellulose: starch = 30: 70: 10) was adhered at 5 g / m ² to obtain a molded body.

Comparative Example 1 Wool (20 to 40 μm) obtained in the same manner as in Example 1
15-80mm) 70% and rayon 2d x 51mm30
%, A non-woven fabric web having 5 g / m ² of ethylcellulose adhered to a non-woven fabric web having a basis weight of 70 g / m ² is hot-pressed into a pot with a mold, and 5 g / m ² of cellulose-acetate resin is further adhered to the inner surface. Then, 5 g / m ^{2 of} the composite binder used in Example 1 was adhered to the outer surface to obtain a molded container.

Comparative Example 2 10 g of the starch-containing composite binder used in Example 2 was applied only to the outer surface of the pot-shaped molded container obtained in Example 1.
/ M ² to obtain a molded container.

[0026] Comparative Example 3 Example 3 and a basis weight 20 g / m ² nonwoven web ethylcellulose 20 g / m ² of deposited allowed to form the base nonwoven obtained at the same specifications as the plug pot shape by thermally molding Thereafter, a molded container was formed in the same manner as in Example 1. 6 obtained in Examples 1 to 3 and Comparative Examples 1 to 3
Table 1 shows the results of investigating the moldability, shape retention, degradability during the seedling raising period and in soil, air permeability, water permeability, and the degree of influence on plants (pertussis) for the seedling raising pots. In addition, comparative examination was similarly performed about a commercially available polypot and a pulp mold plug pot.

[0027]

[Table 1]

As a result, all of the examples are superior to the comparative examples in terms of moldability and shape retention, and are excellent in air permeability and water permeability. It has been found that it has a decomposition period, and when buried in soil, it dissolves and disappears promptly.

[0029]

According to the present invention, the above-mentioned structure is provided.
A biodegradable nonwoven fabric for agricultural and horticultural use, which can be molded by heat, does not decompose during the period required for raising seedlings, and decomposes quickly when embedded in soil, is obtained. Therefore, there is no necessity of incineration, release from harmful substances, damage to the incinerator, etc., and no risk of natural pollution. Furthermore, there is no need for complicated work such as transplantation, which is indispensable for a synthetic resin-based molded body such as a so-called polypot, and there is no need to worry about poor growth or withering because it does not damage the roots. It has.

[Brief description of the drawings]

FIG. 1 is a perspective view of a molded biodegradable nonwoven fabric of the present invention.

FIG. 2 is a perspective view showing another embodiment.

FIG. 3 is an enlarged sectional view of a part a in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Biodegradable nonwoven fabric container 2 Nonwoven fabric base material 3 Cellulosic fiber, animal protein fiber 4 Thermoplastic resin 5 Plastic that biodegrades in a short time 6 Plastic that biodegrades in a long time

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Yoshihara 2-3-3 Hana no Miyamachi, Takamatsu City, Kagawa Prefecture Inside the Industrial Technology Research Institute, Shikoku (72) Inventor Mutsuo Nakagawa 1 Mefu, Takarazuka City, Hyogo Prefecture Chome 21-15 (72) Inventor Teruhiro Komatsu 2-4-4, Mukotoyocho, Amagasaki City, Hyogo Prefecture 50-306 (72) Inventor Shozo Mimura 4-46-8 Ogino, Itami City, Hyogo Prefecture Examiner Makoto Sakata (56 ) References JP-A-2-286013 (JP, A) JP-A-3-240417 (JP, A) JP-A-2-2303 (JP, A)

Claims (4)

(57) [Claims] 1. A regenerated fiber such as viscose or copper ammonia rayon, a cellulosic fiber such as vegetable natural fiber such as cotton or hemp, and an animal protein fiber such as silk or wool, respectively, or a mixture of plural kinds thereof. 30g / m per unit area
^A molded container made of a base nonwoven fabric formed by attaching at least 10% by weight or more of a thermoplastic resin having biodegradability to at least ^two fiber webs as a binder, the molded container being formed on the outer surface of the molded container in a short time. A biodegradable non-woven fabric molding container, wherein a plastic that degrades and a plastic that degrades over a long period of time are adhered to the inner surface. 2. The biodegradable thermoplastic resin is ethyl cellulose or a derivative thereof, polycaprolactone, hydroxypropyl cellulose, a vinyl acetate-vinyl alcohol copolymer having a degree of polymerization of 500 or less, or a biodegradable thermoplastic polyvinyl alcohol. The biodegradable nonwoven fabric-molded container according to claim 1, wherein: 3. A plastic that biodegrades in a short period of time, such as a biodegradable binder containing chitosan-fine cellulose as a main component, a carbohydrate such as corn starch and starch, a vegetable protein such as rice bran, or a plastic such as glycerin. The biodegradable non-woven fabric molded container according to claim 1 or 2, wherein the container is a composite binder mixed with an agent. 4. The plastic according to claim 2, wherein the biodegradable plastic contains an inorganic antibacterial agent such as cellulose-acetate resin or zeolite, or an inorganic or aliphatic water repellent such as silicon. 4. The biodegradable thermoplastic resin according to claim 1, or a biodegradable binder containing chitosan-cellulose according to claim 3 as a main component. Non-woven fabric container.